linux/kernel/module.c

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/*
Copyright (C) 2002 Richard Henderson
Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/export.h>
#include <linux/moduleloader.h>
#include <linux/trace_events.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/sysfs.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/elf.h>
#include <linux/proc_fs.h>
#include <linux/security.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <linux/rcupdate.h>
#include <linux/capability.h>
#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/vermagic.h>
#include <linux/notifier.h>
#include <linux/sched.h>
#include <linux/device.h>
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <linux/license.h>
#include <asm/sections.h>
tracing: Kernel Tracepoints Implementation of kernel tracepoints. Inspired from the Linux Kernel Markers. Allows complete typing verification by declaring both tracing statement inline functions and probe registration/unregistration static inline functions within the same macro "DEFINE_TRACE". No format string is required. See the tracepoint Documentation and Samples patches for usage examples. Taken from the documentation patch : "A tracepoint placed in code provides a hook to call a function (probe) that you can provide at runtime. A tracepoint can be "on" (a probe is connected to it) or "off" (no probe is attached). When a tracepoint is "off" it has no effect, except for adding a tiny time penalty (checking a condition for a branch) and space penalty (adding a few bytes for the function call at the end of the instrumented function and adds a data structure in a separate section). When a tracepoint is "on", the function you provide is called each time the tracepoint is executed, in the execution context of the caller. When the function provided ends its execution, it returns to the caller (continuing from the tracepoint site). You can put tracepoints at important locations in the code. They are lightweight hooks that can pass an arbitrary number of parameters, which prototypes are described in a tracepoint declaration placed in a header file." Addition and removal of tracepoints is synchronized by RCU using the scheduler (and preempt_disable) as guarantees to find a quiescent state (this is really RCU "classic"). The update side uses rcu_barrier_sched() with call_rcu_sched() and the read/execute side uses "preempt_disable()/preempt_enable()". We make sure the previous array containing probes, which has been scheduled for deletion by the rcu callback, is indeed freed before we proceed to the next update. It therefore limits the rate of modification of a single tracepoint to one update per RCU period. The objective here is to permit fast batch add/removal of probes on _different_ tracepoints. Changelog : - Use #name ":" #proto as string to identify the tracepoint in the tracepoint table. This will make sure not type mismatch happens due to connexion of a probe with the wrong type to a tracepoint declared with the same name in a different header. - Add tracepoint_entry_free_old. - Change __TO_TRACE to get rid of the 'i' iterator. Masami Hiramatsu <mhiramat@redhat.com> : Tested on x86-64. Performance impact of a tracepoint : same as markers, except that it adds about 70 bytes of instructions in an unlikely branch of each instrumented function (the for loop, the stack setup and the function call). It currently adds a memory read, a test and a conditional branch at the instrumentation site (in the hot path). Immediate values will eventually change this into a load immediate, test and branch, which removes the memory read which will make the i-cache impact smaller (changing the memory read for a load immediate removes 3-4 bytes per site on x86_32 (depending on mov prefixes), or 7-8 bytes on x86_64, it also saves the d-cache hit). About the performance impact of tracepoints (which is comparable to markers), even without immediate values optimizations, tests done by Hideo Aoki on ia64 show no regression. His test case was using hackbench on a kernel where scheduler instrumentation (about 5 events in code scheduler code) was added. Quoting Hideo Aoki about Markers : I evaluated overhead of kernel marker using linux-2.6-sched-fixes git tree, which includes several markers for LTTng, using an ia64 server. While the immediate trace mark feature isn't implemented on ia64, there is no major performance regression. So, I think that we don't have any issues to propose merging marker point patches into Linus's tree from the viewpoint of performance impact. I prepared two kernels to evaluate. The first one was compiled without CONFIG_MARKERS. The second one was enabled CONFIG_MARKERS. I downloaded the original hackbench from the following URL: http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c I ran hackbench 5 times in each condition and calculated the average and difference between the kernels. The parameter of hackbench: every 50 from 50 to 800 The number of CPUs of the server: 2, 4, and 8 Below is the results. As you can see, major performance regression wasn't found in any case. Even if number of processes increases, differences between marker-enabled kernel and marker- disabled kernel doesn't increase. Moreover, if number of CPUs increases, the differences doesn't increase either. Curiously, marker-enabled kernel is better than marker-disabled kernel in more than half cases, although I guess it comes from the difference of memory access pattern. * 2 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 4.811 | 4.872 | +0.061 | +1.27 | 100 | 9.854 | 10.309 | +0.454 | +4.61 | 150 | 15.602 | 15.040 | -0.562 | -3.6 | 200 | 20.489 | 20.380 | -0.109 | -0.53 | 250 | 25.798 | 25.652 | -0.146 | -0.56 | 300 | 31.260 | 30.797 | -0.463 | -1.48 | 350 | 36.121 | 35.770 | -0.351 | -0.97 | 400 | 42.288 | 42.102 | -0.186 | -0.44 | 450 | 47.778 | 47.253 | -0.526 | -1.1 | 500 | 51.953 | 52.278 | +0.325 | +0.63 | 550 | 58.401 | 57.700 | -0.701 | -1.2 | 600 | 63.334 | 63.222 | -0.112 | -0.18 | 650 | 68.816 | 68.511 | -0.306 | -0.44 | 700 | 74.667 | 74.088 | -0.579 | -0.78 | 750 | 78.612 | 79.582 | +0.970 | +1.23 | 800 | 85.431 | 85.263 | -0.168 | -0.2 | -------------------------------------------------------------- * 4 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.586 | 2.584 | -0.003 | -0.1 | 100 | 5.254 | 5.283 | +0.030 | +0.56 | 150 | 8.012 | 8.074 | +0.061 | +0.76 | 200 | 11.172 | 11.000 | -0.172 | -1.54 | 250 | 13.917 | 14.036 | +0.119 | +0.86 | 300 | 16.905 | 16.543 | -0.362 | -2.14 | 350 | 19.901 | 20.036 | +0.135 | +0.68 | 400 | 22.908 | 23.094 | +0.186 | +0.81 | 450 | 26.273 | 26.101 | -0.172 | -0.66 | 500 | 29.554 | 29.092 | -0.461 | -1.56 | 550 | 32.377 | 32.274 | -0.103 | -0.32 | 600 | 35.855 | 35.322 | -0.533 | -1.49 | 650 | 39.192 | 38.388 | -0.804 | -2.05 | 700 | 41.744 | 41.719 | -0.025 | -0.06 | 750 | 45.016 | 44.496 | -0.520 | -1.16 | 800 | 48.212 | 47.603 | -0.609 | -1.26 | -------------------------------------------------------------- * 8 CPUs Number of | without | with | diff | diff | processes | Marker [Sec] | Marker [Sec] | [Sec] | [%] | -------------------------------------------------------------- 50 | 2.094 | 2.072 | -0.022 | -1.07 | 100 | 4.162 | 4.273 | +0.111 | +2.66 | 150 | 6.485 | 6.540 | +0.055 | +0.84 | 200 | 8.556 | 8.478 | -0.078 | -0.91 | 250 | 10.458 | 10.258 | -0.200 | -1.91 | 300 | 12.425 | 12.750 | +0.325 | +2.62 | 350 | 14.807 | 14.839 | +0.032 | +0.22 | 400 | 16.801 | 16.959 | +0.158 | +0.94 | 450 | 19.478 | 19.009 | -0.470 | -2.41 | 500 | 21.296 | 21.504 | +0.208 | +0.98 | 550 | 23.842 | 23.979 | +0.137 | +0.57 | 600 | 26.309 | 26.111 | -0.198 | -0.75 | 650 | 28.705 | 28.446 | -0.259 | -0.9 | 700 | 31.233 | 31.394 | +0.161 | +0.52 | 750 | 34.064 | 33.720 | -0.344 | -1.01 | 800 | 36.320 | 36.114 | -0.206 | -0.57 | -------------------------------------------------------------- Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Acked-by: 'Peter Zijlstra' <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-19 00:16:16 +08:00
#include <linux/tracepoint.h>
#include <linux/ftrace.h>
#include <linux/livepatch.h>
#include <linux/async.h>
#include <linux/percpu.h>
#include <linux/kmemleak.h>
#include <linux/jump_label.h>
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
#include <linux/pfn.h>
#include <linux/bsearch.h>
#include <uapi/linux/module.h>
#include "module-internal.h"
tracing/events: Add module tracepoints Add trace points to trace module_load, module_free, module_get, module_put and module_request, and use trace_event facility to get the trace output. Here's the sample output: TASK-PID CPU# TIMESTAMP FUNCTION | | | | | <...>-42 [000] 1.758380: module_request: fb0 wait=1 call_site=fb_open ... <...>-60 [000] 3.269403: module_load: scsi_wait_scan <...>-60 [000] 3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0 <...>-61 [001] 3.273168: module_free: scsi_wait_scan ... <...>-1021 [000] 13.836081: module_load: sunrpc <...>-1021 [000] 13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1 <...>-1027 [000] 13.848098: module_get: sunrpc call_site=try_module_get refcnt=0 <...>-1027 [000] 13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1 <...>-1027 [000] 13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0 ... modprobe-2587 [001] 1088.437213: module_load: trace_events_sample F modprobe-2587 [001] 1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0 Note: - the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0 - the module refcnt is percpu, so it can be negative in a specific cpu Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-17 16:56:28 +08:00
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
/*
* Modules' sections will be aligned on page boundaries
* to ensure complete separation of code and data, but
* only when CONFIG_DEBUG_SET_MODULE_RONX=y
*/
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
# define debug_align(X) ALIGN(X, PAGE_SIZE)
#else
# define debug_align(X) (X)
#endif
/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
/*
* Mutex protects:
* 1) List of modules (also safely readable with preempt_disable),
* 2) module_use links,
* 3) module_addr_min/module_addr_max.
* (delete and add uses RCU list operations). */
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
#ifdef CONFIG_MODULES_TREE_LOOKUP
/*
* Use a latched RB-tree for __module_address(); this allows us to use
* RCU-sched lookups of the address from any context.
*
* This is conditional on PERF_EVENTS || TRACING because those can really hit
* __module_address() hard by doing a lot of stack unwinding; potentially from
* NMI context.
*/
static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
{
struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
return (unsigned long)layout->base;
}
static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
{
struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
return (unsigned long)layout->size;
}
static __always_inline bool
mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
{
return __mod_tree_val(a) < __mod_tree_val(b);
}
static __always_inline int
mod_tree_comp(void *key, struct latch_tree_node *n)
{
unsigned long val = (unsigned long)key;
unsigned long start, end;
start = __mod_tree_val(n);
if (val < start)
return -1;
end = start + __mod_tree_size(n);
if (val >= end)
return 1;
return 0;
}
static const struct latch_tree_ops mod_tree_ops = {
.less = mod_tree_less,
.comp = mod_tree_comp,
};
static struct mod_tree_root {
struct latch_tree_root root;
unsigned long addr_min;
unsigned long addr_max;
} mod_tree __cacheline_aligned = {
.addr_min = -1UL,
};
#define module_addr_min mod_tree.addr_min
#define module_addr_max mod_tree.addr_max
static noinline void __mod_tree_insert(struct mod_tree_node *node)
{
latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
}
static void __mod_tree_remove(struct mod_tree_node *node)
{
latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
}
/*
* These modifications: insert, remove_init and remove; are serialized by the
* module_mutex.
*/
static void mod_tree_insert(struct module *mod)
{
mod->core_layout.mtn.mod = mod;
mod->init_layout.mtn.mod = mod;
__mod_tree_insert(&mod->core_layout.mtn);
if (mod->init_layout.size)
__mod_tree_insert(&mod->init_layout.mtn);
}
static void mod_tree_remove_init(struct module *mod)
{
if (mod->init_layout.size)
__mod_tree_remove(&mod->init_layout.mtn);
}
static void mod_tree_remove(struct module *mod)
{
__mod_tree_remove(&mod->core_layout.mtn);
mod_tree_remove_init(mod);
}
static struct module *mod_find(unsigned long addr)
{
struct latch_tree_node *ltn;
ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
if (!ltn)
return NULL;
return container_of(ltn, struct mod_tree_node, node)->mod;
}
#else /* MODULES_TREE_LOOKUP */
static unsigned long module_addr_min = -1UL, module_addr_max = 0;
static void mod_tree_insert(struct module *mod) { }
static void mod_tree_remove_init(struct module *mod) { }
static void mod_tree_remove(struct module *mod) { }
static struct module *mod_find(unsigned long addr)
{
struct module *mod;
list_for_each_entry_rcu(mod, &modules, list) {
if (within_module(addr, mod))
return mod;
}
return NULL;
}
#endif /* MODULES_TREE_LOOKUP */
/*
* Bounds of module text, for speeding up __module_address.
* Protected by module_mutex.
*/
static void __mod_update_bounds(void *base, unsigned int size)
{
unsigned long min = (unsigned long)base;
unsigned long max = min + size;
if (min < module_addr_min)
module_addr_min = min;
if (max > module_addr_max)
module_addr_max = max;
}
static void mod_update_bounds(struct module *mod)
{
__mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
if (mod->init_layout.size)
__mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
}
#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */
static void module_assert_mutex(void)
{
lockdep_assert_held(&module_mutex);
}
static void module_assert_mutex_or_preempt(void)
{
#ifdef CONFIG_LOCKDEP
if (unlikely(!debug_locks))
return;
WARN_ON(!rcu_read_lock_sched_held() &&
!lockdep_is_held(&module_mutex));
#endif
}
static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
#ifndef CONFIG_MODULE_SIG_FORCE
module_param(sig_enforce, bool_enable_only, 0644);
#endif /* !CONFIG_MODULE_SIG_FORCE */
/* Block module loading/unloading? */
int modules_disabled = 0;
core_param(nomodule, modules_disabled, bint, 0);
/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);
[PATCH] Notifier chain update: API changes The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 17:16:30 +08:00
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
int register_module_notifier(struct notifier_block *nb)
{
[PATCH] Notifier chain update: API changes The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 17:16:30 +08:00
return blocking_notifier_chain_register(&module_notify_list, nb);
}
EXPORT_SYMBOL(register_module_notifier);
int unregister_module_notifier(struct notifier_block *nb)
{
[PATCH] Notifier chain update: API changes The kernel's implementation of notifier chains is unsafe. There is no protection against entries being added to or removed from a chain while the chain is in use. The issues were discussed in this thread: http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2 We noticed that notifier chains in the kernel fall into two basic usage classes: "Blocking" chains are always called from a process context and the callout routines are allowed to sleep; "Atomic" chains can be called from an atomic context and the callout routines are not allowed to sleep. We decided to codify this distinction and make it part of the API. Therefore this set of patches introduces three new, parallel APIs: one for blocking notifiers, one for atomic notifiers, and one for "raw" notifiers (which is really just the old API under a new name). New kinds of data structures are used for the heads of the chains, and new routines are defined for registration, unregistration, and calling a chain. The three APIs are explained in include/linux/notifier.h and their implementation is in kernel/sys.c. With atomic and blocking chains, the implementation guarantees that the chain links will not be corrupted and that chain callers will not get messed up by entries being added or removed. For raw chains the implementation provides no guarantees at all; users of this API must provide their own protections. (The idea was that situations may come up where the assumptions of the atomic and blocking APIs are not appropriate, so it should be possible for users to handle these things in their own way.) There are some limitations, which should not be too hard to live with. For atomic/blocking chains, registration and unregistration must always be done in a process context since the chain is protected by a mutex/rwsem. Also, a callout routine for a non-raw chain must not try to register or unregister entries on its own chain. (This did happen in a couple of places and the code had to be changed to avoid it.) Since atomic chains may be called from within an NMI handler, they cannot use spinlocks for synchronization. Instead we use RCU. The overhead falls almost entirely in the unregister routine, which is okay since unregistration is much less frequent that calling a chain. Here is the list of chains that we adjusted and their classifications. None of them use the raw API, so for the moment it is only a placeholder. ATOMIC CHAINS ------------- arch/i386/kernel/traps.c: i386die_chain arch/ia64/kernel/traps.c: ia64die_chain arch/powerpc/kernel/traps.c: powerpc_die_chain arch/sparc64/kernel/traps.c: sparc64die_chain arch/x86_64/kernel/traps.c: die_chain drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list kernel/panic.c: panic_notifier_list kernel/profile.c: task_free_notifier net/bluetooth/hci_core.c: hci_notifier net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain net/ipv6/addrconf.c: inet6addr_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_chain net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain net/netlink/af_netlink.c: netlink_chain BLOCKING CHAINS --------------- arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain arch/s390/kernel/process.c: idle_chain arch/x86_64/kernel/process.c idle_notifier drivers/base/memory.c: memory_chain drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list drivers/macintosh/adb.c: adb_client_list drivers/macintosh/via-pmu.c sleep_notifier_list drivers/macintosh/via-pmu68k.c sleep_notifier_list drivers/macintosh/windfarm_core.c wf_client_list drivers/usb/core/notify.c usb_notifier_list drivers/video/fbmem.c fb_notifier_list kernel/cpu.c cpu_chain kernel/module.c module_notify_list kernel/profile.c munmap_notifier kernel/profile.c task_exit_notifier kernel/sys.c reboot_notifier_list net/core/dev.c netdev_chain net/decnet/dn_dev.c: dnaddr_chain net/ipv4/devinet.c: inetaddr_chain It's possible that some of these classifications are wrong. If they are, please let us know or submit a patch to fix them. Note that any chain that gets called very frequently should be atomic, because the rwsem read-locking used for blocking chains is very likely to incur cache misses on SMP systems. (However, if the chain's callout routines may sleep then the chain cannot be atomic.) The patch set was written by Alan Stern and Chandra Seetharaman, incorporating material written by Keith Owens and suggestions from Paul McKenney and Andrew Morton. [jes@sgi.com: restructure the notifier chain initialization macros] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27 17:16:30 +08:00
return blocking_notifier_chain_unregister(&module_notify_list, nb);
}
EXPORT_SYMBOL(unregister_module_notifier);
struct load_info {
Elf_Ehdr *hdr;
unsigned long len;
Elf_Shdr *sechdrs;
char *secstrings, *strtab;
unsigned long symoffs, stroffs;
struct _ddebug *debug;
unsigned int num_debug;
bool sig_ok;
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
#ifdef CONFIG_KALLSYMS
unsigned long mod_kallsyms_init_off;
#endif
struct {
unsigned int sym, str, mod, vers, info, pcpu;
} index;
};
/* We require a truly strong try_module_get(): 0 means failure due to
ongoing or failed initialization etc. */
static inline int strong_try_module_get(struct module *mod)
{
BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
if (mod && mod->state == MODULE_STATE_COMING)
return -EBUSY;
if (try_module_get(mod))
return 0;
else
return -ENOENT;
}
static inline void add_taint_module(struct module *mod, unsigned flag,
enum lockdep_ok lockdep_ok)
{
add_taint(flag, lockdep_ok);
mod->taints |= (1U << flag);
}
/*
* A thread that wants to hold a reference to a module only while it
* is running can call this to safely exit. nfsd and lockd use this.
*/
void __module_put_and_exit(struct module *mod, long code)
{
module_put(mod);
do_exit(code);
}
EXPORT_SYMBOL(__module_put_and_exit);
/* Find a module section: 0 means not found. */
static unsigned int find_sec(const struct load_info *info, const char *name)
{
unsigned int i;
for (i = 1; i < info->hdr->e_shnum; i++) {
Elf_Shdr *shdr = &info->sechdrs[i];
/* Alloc bit cleared means "ignore it." */
if ((shdr->sh_flags & SHF_ALLOC)
&& strcmp(info->secstrings + shdr->sh_name, name) == 0)
return i;
}
return 0;
}
/* Find a module section, or NULL. */
static void *section_addr(const struct load_info *info, const char *name)
{
/* Section 0 has sh_addr 0. */
return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
}
/* Find a module section, or NULL. Fill in number of "objects" in section. */
static void *section_objs(const struct load_info *info,
const char *name,
size_t object_size,
unsigned int *num)
{
unsigned int sec = find_sec(info, name);
/* Section 0 has sh_addr 0 and sh_size 0. */
*num = info->sechdrs[sec].sh_size / object_size;
return (void *)info->sechdrs[sec].sh_addr;
}
/* Provided by the linker */
extern const struct kernel_symbol __start___ksymtab[];
extern const struct kernel_symbol __stop___ksymtab[];
extern const struct kernel_symbol __start___ksymtab_gpl[];
extern const struct kernel_symbol __stop___ksymtab_gpl[];
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
extern const unsigned long __start___kcrctab_gpl_future[];
#ifdef CONFIG_UNUSED_SYMBOLS
extern const struct kernel_symbol __start___ksymtab_unused[];
extern const struct kernel_symbol __stop___ksymtab_unused[];
extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
extern const unsigned long __start___kcrctab_unused[];
extern const unsigned long __start___kcrctab_unused_gpl[];
#endif
#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif
static bool each_symbol_in_section(const struct symsearch *arr,
unsigned int arrsize,
struct module *owner,
bool (*fn)(const struct symsearch *syms,
struct module *owner,
void *data),
void *data)
{
unsigned int j;
for (j = 0; j < arrsize; j++) {
if (fn(&arr[j], owner, data))
return true;
}
return false;
}
/* Returns true as soon as fn returns true, otherwise false. */
bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
struct module *owner,
void *data),
void *data)
{
struct module *mod;
static const struct symsearch arr[] = {
{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
NOT_GPL_ONLY, false },
{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
__start___kcrctab_gpl,
GPL_ONLY, false },
{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
__start___kcrctab_gpl_future,
WILL_BE_GPL_ONLY, false },
#ifdef CONFIG_UNUSED_SYMBOLS
{ __start___ksymtab_unused, __stop___ksymtab_unused,
__start___kcrctab_unused,
NOT_GPL_ONLY, true },
{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
__start___kcrctab_unused_gpl,
GPL_ONLY, true },
#endif
};
module_assert_mutex_or_preempt();
if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
return true;
list_for_each_entry_rcu(mod, &modules, list) {
struct symsearch arr[] = {
{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
NOT_GPL_ONLY, false },
{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
mod->gpl_crcs,
GPL_ONLY, false },
{ mod->gpl_future_syms,
mod->gpl_future_syms + mod->num_gpl_future_syms,
mod->gpl_future_crcs,
WILL_BE_GPL_ONLY, false },
#ifdef CONFIG_UNUSED_SYMBOLS
{ mod->unused_syms,
mod->unused_syms + mod->num_unused_syms,
mod->unused_crcs,
NOT_GPL_ONLY, true },
{ mod->unused_gpl_syms,
mod->unused_gpl_syms + mod->num_unused_gpl_syms,
mod->unused_gpl_crcs,
GPL_ONLY, true },
#endif
};
if (mod->state == MODULE_STATE_UNFORMED)
continue;
if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
return true;
}
return false;
}
EXPORT_SYMBOL_GPL(each_symbol_section);
struct find_symbol_arg {
/* Input */
const char *name;
bool gplok;
bool warn;
/* Output */
struct module *owner;
const unsigned long *crc;
const struct kernel_symbol *sym;
};
static bool check_symbol(const struct symsearch *syms,
struct module *owner,
unsigned int symnum, void *data)
{
struct find_symbol_arg *fsa = data;
if (!fsa->gplok) {
if (syms->licence == GPL_ONLY)
return false;
if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
pr_warn("Symbol %s is being used by a non-GPL module, "
"which will not be allowed in the future\n",
fsa->name);
}
}
#ifdef CONFIG_UNUSED_SYMBOLS
if (syms->unused && fsa->warn) {
pr_warn("Symbol %s is marked as UNUSED, however this module is "
"using it.\n", fsa->name);
pr_warn("This symbol will go away in the future.\n");
pr_warn("Please evaluate if this is the right api to use and "
"if it really is, submit a report to the linux kernel "
"mailing list together with submitting your code for "
"inclusion.\n");
}
#endif
fsa->owner = owner;
fsa->crc = symversion(syms->crcs, symnum);
fsa->sym = &syms->start[symnum];
return true;
}
static int cmp_name(const void *va, const void *vb)
{
const char *a;
const struct kernel_symbol *b;
a = va; b = vb;
return strcmp(a, b->name);
}
static bool find_symbol_in_section(const struct symsearch *syms,
struct module *owner,
void *data)
{
struct find_symbol_arg *fsa = data;
struct kernel_symbol *sym;
sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
sizeof(struct kernel_symbol), cmp_name);
if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
return true;
return false;
}
/* Find a symbol and return it, along with, (optional) crc and
* (optional) module which owns it. Needs preempt disabled or module_mutex. */
const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const unsigned long **crc,
bool gplok,
bool warn)
{
struct find_symbol_arg fsa;
fsa.name = name;
fsa.gplok = gplok;
fsa.warn = warn;
if (each_symbol_section(find_symbol_in_section, &fsa)) {
if (owner)
*owner = fsa.owner;
if (crc)
*crc = fsa.crc;
return fsa.sym;
}
pr_debug("Failed to find symbol %s\n", name);
return NULL;
}
EXPORT_SYMBOL_GPL(find_symbol);
/*
* Search for module by name: must hold module_mutex (or preempt disabled
* for read-only access).
*/
static struct module *find_module_all(const char *name, size_t len,
bool even_unformed)
{
struct module *mod;
module_assert_mutex_or_preempt();
list_for_each_entry(mod, &modules, list) {
if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
continue;
if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
return mod;
}
return NULL;
}
struct module *find_module(const char *name)
{
module_assert_mutex();
return find_module_all(name, strlen(name), false);
}
EXPORT_SYMBOL_GPL(find_module);
#ifdef CONFIG_SMP
static inline void __percpu *mod_percpu(struct module *mod)
{
return mod->percpu;
}
static int percpu_modalloc(struct module *mod, struct load_info *info)
{
Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
unsigned long align = pcpusec->sh_addralign;
if (!pcpusec->sh_size)
return 0;
if (align > PAGE_SIZE) {
pr_warn("%s: per-cpu alignment %li > %li\n",
mod->name, align, PAGE_SIZE);
align = PAGE_SIZE;
}
mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
if (!mod->percpu) {
pr_warn("%s: Could not allocate %lu bytes percpu data\n",
mod->name, (unsigned long)pcpusec->sh_size);
return -ENOMEM;
}
mod->percpu_size = pcpusec->sh_size;
return 0;
}
static void percpu_modfree(struct module *mod)
{
free_percpu(mod->percpu);
}
static unsigned int find_pcpusec(struct load_info *info)
{
return find_sec(info, ".data..percpu");
}
static void percpu_modcopy(struct module *mod,
const void *from, unsigned long size)
{
int cpu;
for_each_possible_cpu(cpu)
memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
}
/**
* is_module_percpu_address - test whether address is from module static percpu
* @addr: address to test
*
* Test whether @addr belongs to module static percpu area.
*
* RETURNS:
* %true if @addr is from module static percpu area
*/
bool is_module_percpu_address(unsigned long addr)
{
struct module *mod;
unsigned int cpu;
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
if (!mod->percpu_size)
continue;
for_each_possible_cpu(cpu) {
void *start = per_cpu_ptr(mod->percpu, cpu);
if ((void *)addr >= start &&
(void *)addr < start + mod->percpu_size) {
preempt_enable();
return true;
}
}
}
preempt_enable();
return false;
}
#else /* ... !CONFIG_SMP */
static inline void __percpu *mod_percpu(struct module *mod)
{
return NULL;
}
static int percpu_modalloc(struct module *mod, struct load_info *info)
{
/* UP modules shouldn't have this section: ENOMEM isn't quite right */
if (info->sechdrs[info->index.pcpu].sh_size != 0)
return -ENOMEM;
return 0;
}
static inline void percpu_modfree(struct module *mod)
{
}
static unsigned int find_pcpusec(struct load_info *info)
{
return 0;
}
static inline void percpu_modcopy(struct module *mod,
const void *from, unsigned long size)
{
/* pcpusec should be 0, and size of that section should be 0. */
BUG_ON(size != 0);
}
bool is_module_percpu_address(unsigned long addr)
{
return false;
}
#endif /* CONFIG_SMP */
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
#define MODINFO_ATTR(field) \
static void setup_modinfo_##field(struct module *mod, const char *s) \
{ \
mod->field = kstrdup(s, GFP_KERNEL); \
} \
static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
struct module_kobject *mk, char *buffer) \
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
{ \
return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
} \
static int modinfo_##field##_exists(struct module *mod) \
{ \
return mod->field != NULL; \
} \
static void free_modinfo_##field(struct module *mod) \
{ \
kfree(mod->field); \
mod->field = NULL; \
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
} \
static struct module_attribute modinfo_##field = { \
.attr = { .name = __stringify(field), .mode = 0444 }, \
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
.show = show_modinfo_##field, \
.setup = setup_modinfo_##field, \
.test = modinfo_##field##_exists, \
.free = free_modinfo_##field, \
};
MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);
static char last_unloaded_module[MODULE_NAME_LEN+1];
#ifdef CONFIG_MODULE_UNLOAD
EXPORT_TRACEPOINT_SYMBOL(module_get);
/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE 1
/* Init the unload section of the module. */
static int module_unload_init(struct module *mod)
{
/*
* Initialize reference counter to MODULE_REF_BASE.
* refcnt == 0 means module is going.
*/
atomic_set(&mod->refcnt, MODULE_REF_BASE);
INIT_LIST_HEAD(&mod->source_list);
INIT_LIST_HEAD(&mod->target_list);
/* Hold reference count during initialization. */
atomic_inc(&mod->refcnt);
return 0;
}
/* Does a already use b? */
static int already_uses(struct module *a, struct module *b)
{
struct module_use *use;
list_for_each_entry(use, &b->source_list, source_list) {
if (use->source == a) {
pr_debug("%s uses %s!\n", a->name, b->name);
return 1;
}
}
pr_debug("%s does not use %s!\n", a->name, b->name);
return 0;
}
/*
* Module a uses b
* - we add 'a' as a "source", 'b' as a "target" of module use
* - the module_use is added to the list of 'b' sources (so
* 'b' can walk the list to see who sourced them), and of 'a'
* targets (so 'a' can see what modules it targets).
*/
static int add_module_usage(struct module *a, struct module *b)
{
struct module_use *use;
pr_debug("Allocating new usage for %s.\n", a->name);
use = kmalloc(sizeof(*use), GFP_ATOMIC);
if (!use) {
pr_warn("%s: out of memory loading\n", a->name);
return -ENOMEM;
}
use->source = a;
use->target = b;
list_add(&use->source_list, &b->source_list);
list_add(&use->target_list, &a->target_list);
return 0;
}
/* Module a uses b: caller needs module_mutex() */
int ref_module(struct module *a, struct module *b)
{
int err;
if (b == NULL || already_uses(a, b))
return 0;
/* If module isn't available, we fail. */
err = strong_try_module_get(b);
if (err)
return err;
err = add_module_usage(a, b);
if (err) {
module_put(b);
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(ref_module);
/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
struct module_use *use, *tmp;
mutex_lock(&module_mutex);
list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
struct module *i = use->target;
pr_debug("%s unusing %s\n", mod->name, i->name);
module_put(i);
list_del(&use->source_list);
list_del(&use->target_list);
kfree(use);
}
mutex_unlock(&module_mutex);
}
#ifdef CONFIG_MODULE_FORCE_UNLOAD
static inline int try_force_unload(unsigned int flags)
{
int ret = (flags & O_TRUNC);
if (ret)
add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
return ret;
}
#else
static inline int try_force_unload(unsigned int flags)
{
return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */
/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
{
int ret;
/* Try to decrement refcnt which we set at loading */
ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
BUG_ON(ret < 0);
if (ret)
/* Someone can put this right now, recover with checking */
ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
return ret;
}
static int try_stop_module(struct module *mod, int flags, int *forced)
{
/* If it's not unused, quit unless we're forcing. */
if (try_release_module_ref(mod) != 0) {
*forced = try_force_unload(flags);
if (!(*forced))
return -EWOULDBLOCK;
}
/* Mark it as dying. */
mod->state = MODULE_STATE_GOING;
return 0;
}
/**
* module_refcount - return the refcount or -1 if unloading
*
* @mod: the module we're checking
*
* Returns:
* -1 if the module is in the process of unloading
* otherwise the number of references in the kernel to the module
*/
int module_refcount(struct module *mod)
{
return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
}
EXPORT_SYMBOL(module_refcount);
/* This exists whether we can unload or not */
static void free_module(struct module *mod);
SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
unsigned int, flags)
{
struct module *mod;
char name[MODULE_NAME_LEN];
int ret, forced = 0;
if (!capable(CAP_SYS_MODULE) || modules_disabled)
return -EPERM;
if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
if (mutex_lock_interruptible(&module_mutex) != 0)
return -EINTR;
mod = find_module(name);
if (!mod) {
ret = -ENOENT;
goto out;
}
if (!list_empty(&mod->source_list)) {
/* Other modules depend on us: get rid of them first. */
ret = -EWOULDBLOCK;
goto out;
}
/* Doing init or already dying? */
if (mod->state != MODULE_STATE_LIVE) {
/* FIXME: if (force), slam module count damn the torpedoes */
pr_debug("%s already dying\n", mod->name);
ret = -EBUSY;
goto out;
}
/* If it has an init func, it must have an exit func to unload */
if (mod->init && !mod->exit) {
forced = try_force_unload(flags);
if (!forced) {
/* This module can't be removed */
ret = -EBUSY;
goto out;
}
}
/* Stop the machine so refcounts can't move and disable module. */
ret = try_stop_module(mod, flags, &forced);
if (ret != 0)
goto out;
mutex_unlock(&module_mutex);
/* Final destruction now no one is using it. */
if (mod->exit != NULL)
mod->exit();
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
klp_module_going(mod);
ftrace_release_mod(mod);
async_synchronize_full();
/* Store the name of the last unloaded module for diagnostic purposes */
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
free_module(mod);
return 0;
out:
mutex_unlock(&module_mutex);
return ret;
}
static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
struct module_use *use;
int printed_something = 0;
seq_printf(m, " %i ", module_refcount(mod));
/*
* Always include a trailing , so userspace can differentiate
* between this and the old multi-field proc format.
*/
list_for_each_entry(use, &mod->source_list, source_list) {
printed_something = 1;
seq_printf(m, "%s,", use->source->name);
}
if (mod->init != NULL && mod->exit == NULL) {
printed_something = 1;
seq_puts(m, "[permanent],");
}
if (!printed_something)
seq_puts(m, "-");
}
void __symbol_put(const char *symbol)
{
struct module *owner;
preempt_disable();
if (!find_symbol(symbol, &owner, NULL, true, false))
BUG();
module_put(owner);
preempt_enable();
}
EXPORT_SYMBOL(__symbol_put);
/* Note this assumes addr is a function, which it currently always is. */
void symbol_put_addr(void *addr)
{
struct module *modaddr;
unsigned long a = (unsigned long)dereference_function_descriptor(addr);
if (core_kernel_text(a))
return;
/*
* Even though we hold a reference on the module; we still need to
* disable preemption in order to safely traverse the data structure.
*/
preempt_disable();
modaddr = __module_text_address(a);
BUG_ON(!modaddr);
module_put(modaddr);
preempt_enable();
}
EXPORT_SYMBOL_GPL(symbol_put_addr);
static ssize_t show_refcnt(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
return sprintf(buffer, "%i\n", module_refcount(mk->mod));
}
static struct module_attribute modinfo_refcnt =
__ATTR(refcnt, 0444, show_refcnt, NULL);
void __module_get(struct module *module)
{
if (module) {
preempt_disable();
atomic_inc(&module->refcnt);
trace_module_get(module, _RET_IP_);
preempt_enable();
}
}
EXPORT_SYMBOL(__module_get);
bool try_module_get(struct module *module)
{
bool ret = true;
if (module) {
preempt_disable();
/* Note: here, we can fail to get a reference */
if (likely(module_is_live(module) &&
atomic_inc_not_zero(&module->refcnt) != 0))
trace_module_get(module, _RET_IP_);
else
ret = false;
preempt_enable();
}
return ret;
}
EXPORT_SYMBOL(try_module_get);
void module_put(struct module *module)
{
int ret;
if (module) {
preempt_disable();
ret = atomic_dec_if_positive(&module->refcnt);
WARN_ON(ret < 0); /* Failed to put refcount */
trace_module_put(module, _RET_IP_);
preempt_enable();
}
}
EXPORT_SYMBOL(module_put);
#else /* !CONFIG_MODULE_UNLOAD */
static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
/* We don't know the usage count, or what modules are using. */
seq_puts(m, " - -");
}
static inline void module_unload_free(struct module *mod)
{
}
int ref_module(struct module *a, struct module *b)
{
return strong_try_module_get(b);
}
EXPORT_SYMBOL_GPL(ref_module);
static inline int module_unload_init(struct module *mod)
{
return 0;
}
#endif /* CONFIG_MODULE_UNLOAD */
static size_t module_flags_taint(struct module *mod, char *buf)
{
size_t l = 0;
if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
buf[l++] = 'P';
if (mod->taints & (1 << TAINT_OOT_MODULE))
buf[l++] = 'O';
if (mod->taints & (1 << TAINT_FORCED_MODULE))
buf[l++] = 'F';
if (mod->taints & (1 << TAINT_CRAP))
buf[l++] = 'C';
Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE Users have reported being unable to trace non-signed modules loaded within a kernel supporting module signature. This is caused by tracepoint.c:tracepoint_module_coming() refusing to take into account tracepoints sitting within force-loaded modules (TAINT_FORCED_MODULE). The reason for this check, in the first place, is that a force-loaded module may have a struct module incompatible with the layout expected by the kernel, and can thus cause a kernel crash upon forced load of that module on a kernel with CONFIG_TRACEPOINTS=y. Tracepoints, however, specifically accept TAINT_OOT_MODULE and TAINT_CRAP, since those modules do not lead to the "very likely system crash" issue cited above for force-loaded modules. With kernels having CONFIG_MODULE_SIG=y (signed modules), a non-signed module is tainted re-using the TAINT_FORCED_MODULE taint flag. Unfortunately, this means that Tracepoints treat that module as a force-loaded module, and thus silently refuse to consider any tracepoint within this module. Since an unsigned module does not fit within the "very likely system crash" category of tainting, add a new TAINT_UNSIGNED_MODULE taint flag to specifically address this taint behavior, and accept those modules within Tracepoints. We use the letter 'X' as a taint flag character for a module being loaded that doesn't know how to sign its name (proposed by Steven Rostedt). Also add the missing 'O' entry to trace event show_module_flags() list for the sake of completeness. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> NAKed-by: Ingo Molnar <mingo@redhat.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: David Howells <dhowells@redhat.com> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-13 09:41:30 +08:00
if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
buf[l++] = 'E';
/*
* TAINT_FORCED_RMMOD: could be added.
* TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
* apply to modules.
*/
return l;
}
static ssize_t show_initstate(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
const char *state = "unknown";
switch (mk->mod->state) {
case MODULE_STATE_LIVE:
state = "live";
break;
case MODULE_STATE_COMING:
state = "coming";
break;
case MODULE_STATE_GOING:
state = "going";
break;
default:
BUG();
}
return sprintf(buffer, "%s\n", state);
}
static struct module_attribute modinfo_initstate =
__ATTR(initstate, 0444, show_initstate, NULL);
static ssize_t store_uevent(struct module_attribute *mattr,
struct module_kobject *mk,
const char *buffer, size_t count)
{
enum kobject_action action;
if (kobject_action_type(buffer, count, &action) == 0)
kobject_uevent(&mk->kobj, action);
return count;
}
struct module_attribute module_uevent =
__ATTR(uevent, 0200, NULL, store_uevent);
static ssize_t show_coresize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
}
static struct module_attribute modinfo_coresize =
__ATTR(coresize, 0444, show_coresize, NULL);
static ssize_t show_initsize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
}
static struct module_attribute modinfo_initsize =
__ATTR(initsize, 0444, show_initsize, NULL);
static ssize_t show_taint(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
size_t l;
l = module_flags_taint(mk->mod, buffer);
buffer[l++] = '\n';
return l;
}
static struct module_attribute modinfo_taint =
__ATTR(taint, 0444, show_taint, NULL);
static struct module_attribute *modinfo_attrs[] = {
&module_uevent,
&modinfo_version,
&modinfo_srcversion,
&modinfo_initstate,
&modinfo_coresize,
&modinfo_initsize,
&modinfo_taint,
#ifdef CONFIG_MODULE_UNLOAD
&modinfo_refcnt,
#endif
NULL,
};
static const char vermagic[] = VERMAGIC_STRING;
static int try_to_force_load(struct module *mod, const char *reason)
{
#ifdef CONFIG_MODULE_FORCE_LOAD
if (!test_taint(TAINT_FORCED_MODULE))
pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
return 0;
#else
return -ENOEXEC;
#endif
}
#ifdef CONFIG_MODVERSIONS
/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
static unsigned long maybe_relocated(unsigned long crc,
const struct module *crc_owner)
{
#ifdef ARCH_RELOCATES_KCRCTAB
if (crc_owner == NULL)
return crc - (unsigned long)reloc_start;
#endif
return crc;
}
static int check_version(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *symname,
struct module *mod,
const unsigned long *crc,
const struct module *crc_owner)
{
unsigned int i, num_versions;
struct modversion_info *versions;
/* Exporting module didn't supply crcs? OK, we're already tainted. */
if (!crc)
return 1;
/* No versions at all? modprobe --force does this. */
if (versindex == 0)
return try_to_force_load(mod, symname) == 0;
versions = (void *) sechdrs[versindex].sh_addr;
num_versions = sechdrs[versindex].sh_size
/ sizeof(struct modversion_info);
for (i = 0; i < num_versions; i++) {
if (strcmp(versions[i].name, symname) != 0)
continue;
if (versions[i].crc == maybe_relocated(*crc, crc_owner))
return 1;
pr_debug("Found checksum %lX vs module %lX\n",
maybe_relocated(*crc, crc_owner), versions[i].crc);
goto bad_version;
}
pr_warn("%s: no symbol version for %s\n", mod->name, symname);
return 0;
bad_version:
pr_warn("%s: disagrees about version of symbol %s\n",
mod->name, symname);
return 0;
}
static inline int check_modstruct_version(Elf_Shdr *sechdrs,
unsigned int versindex,
struct module *mod)
{
const unsigned long *crc;
module: Annotate module version magic Due to the new lockdep checks in the coming patch, we go: [ 9.759380] ------------[ cut here ]------------ [ 9.759389] WARNING: CPU: 31 PID: 597 at ../kernel/module.c:216 each_symbol_section+0x121/0x130() [ 9.759391] Modules linked in: [ 9.759393] CPU: 31 PID: 597 Comm: modprobe Not tainted 4.0.0-rc1+ #65 [ 9.759393] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 [ 9.759396] ffffffff817d8676 ffff880424567ca8 ffffffff8157e98b 0000000000000001 [ 9.759398] 0000000000000000 ffff880424567ce8 ffffffff8105fbc7 ffff880424567cd8 [ 9.759400] 0000000000000000 ffffffff810ec160 ffff880424567d40 0000000000000000 [ 9.759400] Call Trace: [ 9.759407] [<ffffffff8157e98b>] dump_stack+0x4f/0x7b [ 9.759410] [<ffffffff8105fbc7>] warn_slowpath_common+0x97/0xe0 [ 9.759412] [<ffffffff810ec160>] ? section_objs+0x60/0x60 [ 9.759414] [<ffffffff8105fc2a>] warn_slowpath_null+0x1a/0x20 [ 9.759415] [<ffffffff810ed9c1>] each_symbol_section+0x121/0x130 [ 9.759417] [<ffffffff810eda01>] find_symbol+0x31/0x70 [ 9.759420] [<ffffffff810ef5bf>] load_module+0x20f/0x2660 [ 9.759422] [<ffffffff8104ef10>] ? __do_page_fault+0x190/0x4e0 [ 9.759426] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759427] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759433] [<ffffffff810ae73d>] ? trace_hardirqs_on_caller+0x11d/0x1e0 [ 9.759437] [<ffffffff812fcc0e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 9.759439] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759441] [<ffffffff810f1ade>] SyS_init_module+0xce/0x100 [ 9.759443] [<ffffffff81587429>] system_call_fastpath+0x12/0x17 [ 9.759445] ---[ end trace 9294429076a9c644 ]--- As per the comment this site should be fine, but lets wrap it in preempt_disable() anyhow to placate lockdep. Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-27 09:39:35 +08:00
/*
* Since this should be found in kernel (which can't be removed), no
* locking is necessary -- use preempt_disable() to placate lockdep.
*/
preempt_disable();
if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
module: Annotate module version magic Due to the new lockdep checks in the coming patch, we go: [ 9.759380] ------------[ cut here ]------------ [ 9.759389] WARNING: CPU: 31 PID: 597 at ../kernel/module.c:216 each_symbol_section+0x121/0x130() [ 9.759391] Modules linked in: [ 9.759393] CPU: 31 PID: 597 Comm: modprobe Not tainted 4.0.0-rc1+ #65 [ 9.759393] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 [ 9.759396] ffffffff817d8676 ffff880424567ca8 ffffffff8157e98b 0000000000000001 [ 9.759398] 0000000000000000 ffff880424567ce8 ffffffff8105fbc7 ffff880424567cd8 [ 9.759400] 0000000000000000 ffffffff810ec160 ffff880424567d40 0000000000000000 [ 9.759400] Call Trace: [ 9.759407] [<ffffffff8157e98b>] dump_stack+0x4f/0x7b [ 9.759410] [<ffffffff8105fbc7>] warn_slowpath_common+0x97/0xe0 [ 9.759412] [<ffffffff810ec160>] ? section_objs+0x60/0x60 [ 9.759414] [<ffffffff8105fc2a>] warn_slowpath_null+0x1a/0x20 [ 9.759415] [<ffffffff810ed9c1>] each_symbol_section+0x121/0x130 [ 9.759417] [<ffffffff810eda01>] find_symbol+0x31/0x70 [ 9.759420] [<ffffffff810ef5bf>] load_module+0x20f/0x2660 [ 9.759422] [<ffffffff8104ef10>] ? __do_page_fault+0x190/0x4e0 [ 9.759426] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759427] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759433] [<ffffffff810ae73d>] ? trace_hardirqs_on_caller+0x11d/0x1e0 [ 9.759437] [<ffffffff812fcc0e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 9.759439] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759441] [<ffffffff810f1ade>] SyS_init_module+0xce/0x100 [ 9.759443] [<ffffffff81587429>] system_call_fastpath+0x12/0x17 [ 9.759445] ---[ end trace 9294429076a9c644 ]--- As per the comment this site should be fine, but lets wrap it in preempt_disable() anyhow to placate lockdep. Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-27 09:39:35 +08:00
&crc, true, false)) {
preempt_enable();
BUG();
module: Annotate module version magic Due to the new lockdep checks in the coming patch, we go: [ 9.759380] ------------[ cut here ]------------ [ 9.759389] WARNING: CPU: 31 PID: 597 at ../kernel/module.c:216 each_symbol_section+0x121/0x130() [ 9.759391] Modules linked in: [ 9.759393] CPU: 31 PID: 597 Comm: modprobe Not tainted 4.0.0-rc1+ #65 [ 9.759393] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 [ 9.759396] ffffffff817d8676 ffff880424567ca8 ffffffff8157e98b 0000000000000001 [ 9.759398] 0000000000000000 ffff880424567ce8 ffffffff8105fbc7 ffff880424567cd8 [ 9.759400] 0000000000000000 ffffffff810ec160 ffff880424567d40 0000000000000000 [ 9.759400] Call Trace: [ 9.759407] [<ffffffff8157e98b>] dump_stack+0x4f/0x7b [ 9.759410] [<ffffffff8105fbc7>] warn_slowpath_common+0x97/0xe0 [ 9.759412] [<ffffffff810ec160>] ? section_objs+0x60/0x60 [ 9.759414] [<ffffffff8105fc2a>] warn_slowpath_null+0x1a/0x20 [ 9.759415] [<ffffffff810ed9c1>] each_symbol_section+0x121/0x130 [ 9.759417] [<ffffffff810eda01>] find_symbol+0x31/0x70 [ 9.759420] [<ffffffff810ef5bf>] load_module+0x20f/0x2660 [ 9.759422] [<ffffffff8104ef10>] ? __do_page_fault+0x190/0x4e0 [ 9.759426] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759427] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759433] [<ffffffff810ae73d>] ? trace_hardirqs_on_caller+0x11d/0x1e0 [ 9.759437] [<ffffffff812fcc0e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 9.759439] [<ffffffff815880ec>] ? retint_restore_args+0x13/0x13 [ 9.759441] [<ffffffff810f1ade>] SyS_init_module+0xce/0x100 [ 9.759443] [<ffffffff81587429>] system_call_fastpath+0x12/0x17 [ 9.759445] ---[ end trace 9294429076a9c644 ]--- As per the comment this site should be fine, but lets wrap it in preempt_disable() anyhow to placate lockdep. Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-27 09:39:35 +08:00
}
preempt_enable();
return check_version(sechdrs, versindex,
VMLINUX_SYMBOL_STR(module_layout), mod, crc,
NULL);
}
/* First part is kernel version, which we ignore if module has crcs. */
static inline int same_magic(const char *amagic, const char *bmagic,
bool has_crcs)
{
if (has_crcs) {
amagic += strcspn(amagic, " ");
bmagic += strcspn(bmagic, " ");
}
return strcmp(amagic, bmagic) == 0;
}
#else
static inline int check_version(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *symname,
struct module *mod,
const unsigned long *crc,
const struct module *crc_owner)
{
return 1;
}
static inline int check_modstruct_version(Elf_Shdr *sechdrs,
unsigned int versindex,
struct module *mod)
{
return 1;
}
static inline int same_magic(const char *amagic, const char *bmagic,
bool has_crcs)
{
return strcmp(amagic, bmagic) == 0;
}
#endif /* CONFIG_MODVERSIONS */
/* Resolve a symbol for this module. I.e. if we find one, record usage. */
static const struct kernel_symbol *resolve_symbol(struct module *mod,
const struct load_info *info,
const char *name,
char ownername[])
{
struct module *owner;
const struct kernel_symbol *sym;
const unsigned long *crc;
int err;
/*
* The module_mutex should not be a heavily contended lock;
* if we get the occasional sleep here, we'll go an extra iteration
* in the wait_event_interruptible(), which is harmless.
*/
sched_annotate_sleep();
mutex_lock(&module_mutex);
sym = find_symbol(name, &owner, &crc,
!(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
if (!sym)
goto unlock;
if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
owner)) {
sym = ERR_PTR(-EINVAL);
goto getname;
}
err = ref_module(mod, owner);
if (err) {
sym = ERR_PTR(err);
goto getname;
}
getname:
/* We must make copy under the lock if we failed to get ref. */
strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
unlock:
mutex_unlock(&module_mutex);
return sym;
}
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
const struct load_info *info,
const char *name)
{
const struct kernel_symbol *ksym;
char owner[MODULE_NAME_LEN];
if (wait_event_interruptible_timeout(module_wq,
!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
|| PTR_ERR(ksym) != -EBUSY,
30 * HZ) <= 0) {
pr_warn("%s: gave up waiting for init of module %s.\n",
mod->name, owner);
}
return ksym;
}
/*
* /sys/module/foo/sections stuff
* J. Corbet <corbet@lwn.net>
*/
#ifdef CONFIG_SYSFS
#ifdef CONFIG_KALLSYMS
static inline bool sect_empty(const Elf_Shdr *sect)
{
return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}
struct module_sect_attr {
struct module_attribute mattr;
char *name;
unsigned long address;
};
struct module_sect_attrs {
struct attribute_group grp;
unsigned int nsections;
struct module_sect_attr attrs[0];
};
static ssize_t module_sect_show(struct module_attribute *mattr,
struct module_kobject *mk, char *buf)
{
struct module_sect_attr *sattr =
container_of(mattr, struct module_sect_attr, mattr);
return sprintf(buf, "0x%pK\n", (void *)sattr->address);
}
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
unsigned int section;
for (section = 0; section < sect_attrs->nsections; section++)
kfree(sect_attrs->attrs[section].name);
kfree(sect_attrs);
}
static void add_sect_attrs(struct module *mod, const struct load_info *info)
{
unsigned int nloaded = 0, i, size[2];
struct module_sect_attrs *sect_attrs;
struct module_sect_attr *sattr;
struct attribute **gattr;
/* Count loaded sections and allocate structures */
for (i = 0; i < info->hdr->e_shnum; i++)
if (!sect_empty(&info->sechdrs[i]))
nloaded++;
size[0] = ALIGN(sizeof(*sect_attrs)
+ nloaded * sizeof(sect_attrs->attrs[0]),
sizeof(sect_attrs->grp.attrs[0]));
size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
if (sect_attrs == NULL)
return;
/* Setup section attributes. */
sect_attrs->grp.name = "sections";
sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
sect_attrs->nsections = 0;
sattr = &sect_attrs->attrs[0];
gattr = &sect_attrs->grp.attrs[0];
for (i = 0; i < info->hdr->e_shnum; i++) {
Elf_Shdr *sec = &info->sechdrs[i];
if (sect_empty(sec))
modules: don't export section names of empty sections via sysfs On the parisc architecture we face for each and every loaded kernel module this kernel "badness warning": sysfs: cannot create duplicate filename '/module/ac97_bus/sections/.text' Badness at fs/sysfs/dir.c:487 Reason for that is, that on parisc all kernel modules do have multiple .text sections due to the usage of the -ffunction-sections compiler flag which is needed to reach all jump targets on this platform. An objdump on such a kernel module gives: Sections: Idx Name Size VMA LMA File off Algn 0 .note.gnu.build-id 00000024 00000000 00000000 00000034 2**2 CONTENTS, ALLOC, LOAD, READONLY, DATA 1 .text 00000000 00000000 00000000 00000058 2**0 CONTENTS, ALLOC, LOAD, READONLY, CODE 2 .text.ac97_bus_match 0000001c 00000000 00000000 00000058 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 3 .text 00000000 00000000 00000000 000000d4 2**0 CONTENTS, ALLOC, LOAD, READONLY, CODE ... Since the .text sections are empty (size of 0 bytes) and won't be loaded by the kernel module loader anyway, I don't see a reason why such sections need to be listed under /sys/module/<module_name>/sections/<section_name> either. The attached patch does solve this issue by not exporting section names which are empty. This fixes bugzilla http://bugzilla.kernel.org/show_bug.cgi?id=14703 Signed-off-by: Helge Deller <deller@gmx.de> CC: rusty@rustcorp.com.au CC: akpm@linux-foundation.org CC: James.Bottomley@HansenPartnership.com CC: roland@redhat.com CC: dave@hiauly1.hia.nrc.ca Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-03 07:29:15 +08:00
continue;
sattr->address = sec->sh_addr;
sattr->name = kstrdup(info->secstrings + sec->sh_name,
GFP_KERNEL);
if (sattr->name == NULL)
goto out;
sect_attrs->nsections++;
sysfs_attr_init(&sattr->mattr.attr);
sattr->mattr.show = module_sect_show;
sattr->mattr.store = NULL;
sattr->mattr.attr.name = sattr->name;
sattr->mattr.attr.mode = S_IRUGO;
*(gattr++) = &(sattr++)->mattr.attr;
}
*gattr = NULL;
if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
goto out;
mod->sect_attrs = sect_attrs;
return;
out:
free_sect_attrs(sect_attrs);
}
static void remove_sect_attrs(struct module *mod)
{
if (mod->sect_attrs) {
sysfs_remove_group(&mod->mkobj.kobj,
&mod->sect_attrs->grp);
/* We are positive that no one is using any sect attrs
* at this point. Deallocate immediately. */
free_sect_attrs(mod->sect_attrs);
mod->sect_attrs = NULL;
}
}
/*
* /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
*/
struct module_notes_attrs {
struct kobject *dir;
unsigned int notes;
struct bin_attribute attrs[0];
};
static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t count)
{
/*
* The caller checked the pos and count against our size.
*/
memcpy(buf, bin_attr->private + pos, count);
return count;
}
static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
unsigned int i)
{
if (notes_attrs->dir) {
while (i-- > 0)
sysfs_remove_bin_file(notes_attrs->dir,
&notes_attrs->attrs[i]);
kobject_put(notes_attrs->dir);
}
kfree(notes_attrs);
}
static void add_notes_attrs(struct module *mod, const struct load_info *info)
{
unsigned int notes, loaded, i;
struct module_notes_attrs *notes_attrs;
struct bin_attribute *nattr;
/* failed to create section attributes, so can't create notes */
if (!mod->sect_attrs)
return;
/* Count notes sections and allocate structures. */
notes = 0;
for (i = 0; i < info->hdr->e_shnum; i++)
if (!sect_empty(&info->sechdrs[i]) &&
(info->sechdrs[i].sh_type == SHT_NOTE))
++notes;
if (notes == 0)
return;
notes_attrs = kzalloc(sizeof(*notes_attrs)
+ notes * sizeof(notes_attrs->attrs[0]),
GFP_KERNEL);
if (notes_attrs == NULL)
return;
notes_attrs->notes = notes;
nattr = &notes_attrs->attrs[0];
for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
if (sect_empty(&info->sechdrs[i]))
continue;
if (info->sechdrs[i].sh_type == SHT_NOTE) {
sysfs_bin_attr_init(nattr);
nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
nattr->attr.mode = S_IRUGO;
nattr->size = info->sechdrs[i].sh_size;
nattr->private = (void *) info->sechdrs[i].sh_addr;
nattr->read = module_notes_read;
++nattr;
}
++loaded;
}
notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
if (!notes_attrs->dir)
goto out;
for (i = 0; i < notes; ++i)
if (sysfs_create_bin_file(notes_attrs->dir,
&notes_attrs->attrs[i]))
goto out;
mod->notes_attrs = notes_attrs;
return;
out:
free_notes_attrs(notes_attrs, i);
}
static void remove_notes_attrs(struct module *mod)
{
if (mod->notes_attrs)
free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
}
#else
static inline void add_sect_attrs(struct module *mod,
const struct load_info *info)
{
}
static inline void remove_sect_attrs(struct module *mod)
{
}
static inline void add_notes_attrs(struct module *mod,
const struct load_info *info)
{
}
static inline void remove_notes_attrs(struct module *mod)
{
}
#endif /* CONFIG_KALLSYMS */
static void add_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
struct module_use *use;
int nowarn;
mutex_lock(&module_mutex);
list_for_each_entry(use, &mod->target_list, target_list) {
nowarn = sysfs_create_link(use->target->holders_dir,
&mod->mkobj.kobj, mod->name);
}
mutex_unlock(&module_mutex);
#endif
}
static void del_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
struct module_use *use;
mutex_lock(&module_mutex);
list_for_each_entry(use, &mod->target_list, target_list)
sysfs_remove_link(use->target->holders_dir, mod->name);
mutex_unlock(&module_mutex);
#endif
}
static int module_add_modinfo_attrs(struct module *mod)
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
{
struct module_attribute *attr;
struct module_attribute *temp_attr;
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
int error = 0;
int i;
mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
(ARRAY_SIZE(modinfo_attrs) + 1)),
GFP_KERNEL);
if (!mod->modinfo_attrs)
return -ENOMEM;
temp_attr = mod->modinfo_attrs;
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
if (!attr->test ||
(attr->test && attr->test(mod))) {
memcpy(temp_attr, attr, sizeof(*temp_attr));
sysfs_attr_init(&temp_attr->attr);
error = sysfs_create_file(&mod->mkobj.kobj,
&temp_attr->attr);
++temp_attr;
}
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
}
return error;
}
static void module_remove_modinfo_attrs(struct module *mod)
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
{
struct module_attribute *attr;
int i;
for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
/* pick a field to test for end of list */
if (!attr->attr.name)
break;
sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
if (attr->free)
attr->free(mod);
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
}
kfree(mod->modinfo_attrs);
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
}
module: Fix mod->mkobj.kobj potentially freed too early DEBUG_KOBJECT_RELEASE helps to find the issue attached below. After some investigation, it seems the reason is: The mod->mkobj.kobj(ffffffffa01600d0 below) is freed together with mod itself in free_module(). However, its children still hold references to it, as the delay caused by DEBUG_KOBJECT_RELEASE. So when the child(holders below) tries to decrease the reference count to its parent in kobject_del(), BUG happens as it tries to access already freed memory. This patch tries to fix it by waiting for the mod->mkobj.kobj to be really released in the module removing process (and some error code paths). [ 1844.175287] kobject: 'holders' (ffff88007c1f1600): kobject_release, parent ffffffffa01600d0 (delayed) [ 1844.178991] kobject: 'notes' (ffff8800370b2a00): kobject_release, parent ffffffffa01600d0 (delayed) [ 1845.180118] kobject: 'holders' (ffff88007c1f1600): kobject_cleanup, parent ffffffffa01600d0 [ 1845.182130] kobject: 'holders' (ffff88007c1f1600): auto cleanup kobject_del [ 1845.184120] BUG: unable to handle kernel paging request at ffffffffa01601d0 [ 1845.185026] IP: [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] PGD 1a13067 PUD 1a14063 PMD 7bd30067 PTE 0 [ 1845.185026] Oops: 0000 [#1] PREEMPT [ 1845.185026] Modules linked in: xfs libcrc32c [last unloaded: kprobe_example] [ 1845.185026] CPU: 0 PID: 18 Comm: kworker/0:1 Tainted: G O 3.11.0-rc6-next-20130819+ #1 [ 1845.185026] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 1845.185026] Workqueue: events kobject_delayed_cleanup [ 1845.185026] task: ffff88007ca51f00 ti: ffff88007ca5c000 task.ti: ffff88007ca5c000 [ 1845.185026] RIP: 0010:[<ffffffff812cda81>] [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP: 0018:ffff88007ca5dd08 EFLAGS: 00010282 [ 1845.185026] RAX: 0000000000002000 RBX: ffffffffa01600d0 RCX: ffffffff8177d638 [ 1845.185026] RDX: ffff88007ca5dc18 RSI: 0000000000000000 RDI: ffffffffa01600d0 [ 1845.185026] RBP: ffff88007ca5dd18 R08: ffffffff824e9810 R09: ffffffffffffffff [ 1845.185026] R10: ffff8800ffffffff R11: dead4ead00000001 R12: ffffffff81a95040 [ 1845.185026] R13: ffff88007b27a960 R14: ffff88007c1f1600 R15: 0000000000000000 [ 1845.185026] FS: 0000000000000000(0000) GS:ffffffff81a23000(0000) knlGS:0000000000000000 [ 1845.185026] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1845.185026] CR2: ffffffffa01601d0 CR3: 0000000037207000 CR4: 00000000000006b0 [ 1845.185026] Stack: [ 1845.185026] ffff88007c1f1600 ffff88007c1f1600 ffff88007ca5dd38 ffffffff812cdb7e [ 1845.185026] 0000000000000000 ffff88007c1f1640 ffff88007ca5dd68 ffffffff812cdbfe [ 1845.185026] ffff88007c974800 ffff88007c1f1640 ffff88007ff61a00 0000000000000000 [ 1845.185026] Call Trace: [ 1845.185026] [<ffffffff812cdb7e>] kobject_del+0x2e/0x40 [ 1845.185026] [<ffffffff812cdbfe>] kobject_delayed_cleanup+0x6e/0x1d0 [ 1845.185026] [<ffffffff81063a45>] process_one_work+0x1e5/0x670 [ 1845.185026] [<ffffffff810639e3>] ? process_one_work+0x183/0x670 [ 1845.185026] [<ffffffff810642b3>] worker_thread+0x113/0x370 [ 1845.185026] [<ffffffff810641a0>] ? rescuer_thread+0x290/0x290 [ 1845.185026] [<ffffffff8106bfba>] kthread+0xda/0xe0 [ 1845.185026] [<ffffffff814ff0f0>] ? _raw_spin_unlock_irq+0x30/0x60 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] [<ffffffff8150751a>] ret_from_fork+0x7a/0xb0 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] Code: 81 48 c7 c7 28 95 ad 81 31 c0 e8 9b da 01 00 e9 4f ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1d <f6> 87 00 01 00 00 01 74 1e 48 8d 7b 38 83 6b 38 01 0f 94 c0 84 [ 1845.185026] RIP [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP <ffff88007ca5dd08> [ 1845.185026] CR2: ffffffffa01601d0 [ 1845.185026] ---[ end trace 49a70afd109f5653 ]--- Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-09-03 15:03:57 +08:00
static void mod_kobject_put(struct module *mod)
{
DECLARE_COMPLETION_ONSTACK(c);
mod->mkobj.kobj_completion = &c;
kobject_put(&mod->mkobj.kobj);
wait_for_completion(&c);
}
static int mod_sysfs_init(struct module *mod)
{
int err;
struct kobject *kobj;
if (!module_sysfs_initialized) {
pr_err("%s: module sysfs not initialized\n", mod->name);
err = -EINVAL;
goto out;
}
kobj = kset_find_obj(module_kset, mod->name);
if (kobj) {
pr_err("%s: module is already loaded\n", mod->name);
kobject_put(kobj);
err = -EINVAL;
goto out;
}
mod->mkobj.mod = mod;
memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
mod->mkobj.kobj.kset = module_kset;
err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
"%s", mod->name);
if (err)
module: Fix mod->mkobj.kobj potentially freed too early DEBUG_KOBJECT_RELEASE helps to find the issue attached below. After some investigation, it seems the reason is: The mod->mkobj.kobj(ffffffffa01600d0 below) is freed together with mod itself in free_module(). However, its children still hold references to it, as the delay caused by DEBUG_KOBJECT_RELEASE. So when the child(holders below) tries to decrease the reference count to its parent in kobject_del(), BUG happens as it tries to access already freed memory. This patch tries to fix it by waiting for the mod->mkobj.kobj to be really released in the module removing process (and some error code paths). [ 1844.175287] kobject: 'holders' (ffff88007c1f1600): kobject_release, parent ffffffffa01600d0 (delayed) [ 1844.178991] kobject: 'notes' (ffff8800370b2a00): kobject_release, parent ffffffffa01600d0 (delayed) [ 1845.180118] kobject: 'holders' (ffff88007c1f1600): kobject_cleanup, parent ffffffffa01600d0 [ 1845.182130] kobject: 'holders' (ffff88007c1f1600): auto cleanup kobject_del [ 1845.184120] BUG: unable to handle kernel paging request at ffffffffa01601d0 [ 1845.185026] IP: [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] PGD 1a13067 PUD 1a14063 PMD 7bd30067 PTE 0 [ 1845.185026] Oops: 0000 [#1] PREEMPT [ 1845.185026] Modules linked in: xfs libcrc32c [last unloaded: kprobe_example] [ 1845.185026] CPU: 0 PID: 18 Comm: kworker/0:1 Tainted: G O 3.11.0-rc6-next-20130819+ #1 [ 1845.185026] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 1845.185026] Workqueue: events kobject_delayed_cleanup [ 1845.185026] task: ffff88007ca51f00 ti: ffff88007ca5c000 task.ti: ffff88007ca5c000 [ 1845.185026] RIP: 0010:[<ffffffff812cda81>] [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP: 0018:ffff88007ca5dd08 EFLAGS: 00010282 [ 1845.185026] RAX: 0000000000002000 RBX: ffffffffa01600d0 RCX: ffffffff8177d638 [ 1845.185026] RDX: ffff88007ca5dc18 RSI: 0000000000000000 RDI: ffffffffa01600d0 [ 1845.185026] RBP: ffff88007ca5dd18 R08: ffffffff824e9810 R09: ffffffffffffffff [ 1845.185026] R10: ffff8800ffffffff R11: dead4ead00000001 R12: ffffffff81a95040 [ 1845.185026] R13: ffff88007b27a960 R14: ffff88007c1f1600 R15: 0000000000000000 [ 1845.185026] FS: 0000000000000000(0000) GS:ffffffff81a23000(0000) knlGS:0000000000000000 [ 1845.185026] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1845.185026] CR2: ffffffffa01601d0 CR3: 0000000037207000 CR4: 00000000000006b0 [ 1845.185026] Stack: [ 1845.185026] ffff88007c1f1600 ffff88007c1f1600 ffff88007ca5dd38 ffffffff812cdb7e [ 1845.185026] 0000000000000000 ffff88007c1f1640 ffff88007ca5dd68 ffffffff812cdbfe [ 1845.185026] ffff88007c974800 ffff88007c1f1640 ffff88007ff61a00 0000000000000000 [ 1845.185026] Call Trace: [ 1845.185026] [<ffffffff812cdb7e>] kobject_del+0x2e/0x40 [ 1845.185026] [<ffffffff812cdbfe>] kobject_delayed_cleanup+0x6e/0x1d0 [ 1845.185026] [<ffffffff81063a45>] process_one_work+0x1e5/0x670 [ 1845.185026] [<ffffffff810639e3>] ? process_one_work+0x183/0x670 [ 1845.185026] [<ffffffff810642b3>] worker_thread+0x113/0x370 [ 1845.185026] [<ffffffff810641a0>] ? rescuer_thread+0x290/0x290 [ 1845.185026] [<ffffffff8106bfba>] kthread+0xda/0xe0 [ 1845.185026] [<ffffffff814ff0f0>] ? _raw_spin_unlock_irq+0x30/0x60 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] [<ffffffff8150751a>] ret_from_fork+0x7a/0xb0 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] Code: 81 48 c7 c7 28 95 ad 81 31 c0 e8 9b da 01 00 e9 4f ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1d <f6> 87 00 01 00 00 01 74 1e 48 8d 7b 38 83 6b 38 01 0f 94 c0 84 [ 1845.185026] RIP [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP <ffff88007ca5dd08> [ 1845.185026] CR2: ffffffffa01601d0 [ 1845.185026] ---[ end trace 49a70afd109f5653 ]--- Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-09-03 15:03:57 +08:00
mod_kobject_put(mod);
/* delay uevent until full sysfs population */
out:
return err;
}
static int mod_sysfs_setup(struct module *mod,
const struct load_info *info,
struct kernel_param *kparam,
unsigned int num_params)
{
int err;
err = mod_sysfs_init(mod);
if (err)
goto out;
mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
if (!mod->holders_dir) {
err = -ENOMEM;
goto out_unreg;
}
err = module_param_sysfs_setup(mod, kparam, num_params);
if (err)
goto out_unreg_holders;
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
err = module_add_modinfo_attrs(mod);
if (err)
goto out_unreg_param;
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
add_usage_links(mod);
add_sect_attrs(mod, info);
add_notes_attrs(mod, info);
kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
return 0;
out_unreg_param:
module_param_sysfs_remove(mod);
out_unreg_holders:
kobject_put(mod->holders_dir);
out_unreg:
module: Fix mod->mkobj.kobj potentially freed too early DEBUG_KOBJECT_RELEASE helps to find the issue attached below. After some investigation, it seems the reason is: The mod->mkobj.kobj(ffffffffa01600d0 below) is freed together with mod itself in free_module(). However, its children still hold references to it, as the delay caused by DEBUG_KOBJECT_RELEASE. So when the child(holders below) tries to decrease the reference count to its parent in kobject_del(), BUG happens as it tries to access already freed memory. This patch tries to fix it by waiting for the mod->mkobj.kobj to be really released in the module removing process (and some error code paths). [ 1844.175287] kobject: 'holders' (ffff88007c1f1600): kobject_release, parent ffffffffa01600d0 (delayed) [ 1844.178991] kobject: 'notes' (ffff8800370b2a00): kobject_release, parent ffffffffa01600d0 (delayed) [ 1845.180118] kobject: 'holders' (ffff88007c1f1600): kobject_cleanup, parent ffffffffa01600d0 [ 1845.182130] kobject: 'holders' (ffff88007c1f1600): auto cleanup kobject_del [ 1845.184120] BUG: unable to handle kernel paging request at ffffffffa01601d0 [ 1845.185026] IP: [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] PGD 1a13067 PUD 1a14063 PMD 7bd30067 PTE 0 [ 1845.185026] Oops: 0000 [#1] PREEMPT [ 1845.185026] Modules linked in: xfs libcrc32c [last unloaded: kprobe_example] [ 1845.185026] CPU: 0 PID: 18 Comm: kworker/0:1 Tainted: G O 3.11.0-rc6-next-20130819+ #1 [ 1845.185026] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 1845.185026] Workqueue: events kobject_delayed_cleanup [ 1845.185026] task: ffff88007ca51f00 ti: ffff88007ca5c000 task.ti: ffff88007ca5c000 [ 1845.185026] RIP: 0010:[<ffffffff812cda81>] [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP: 0018:ffff88007ca5dd08 EFLAGS: 00010282 [ 1845.185026] RAX: 0000000000002000 RBX: ffffffffa01600d0 RCX: ffffffff8177d638 [ 1845.185026] RDX: ffff88007ca5dc18 RSI: 0000000000000000 RDI: ffffffffa01600d0 [ 1845.185026] RBP: ffff88007ca5dd18 R08: ffffffff824e9810 R09: ffffffffffffffff [ 1845.185026] R10: ffff8800ffffffff R11: dead4ead00000001 R12: ffffffff81a95040 [ 1845.185026] R13: ffff88007b27a960 R14: ffff88007c1f1600 R15: 0000000000000000 [ 1845.185026] FS: 0000000000000000(0000) GS:ffffffff81a23000(0000) knlGS:0000000000000000 [ 1845.185026] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1845.185026] CR2: ffffffffa01601d0 CR3: 0000000037207000 CR4: 00000000000006b0 [ 1845.185026] Stack: [ 1845.185026] ffff88007c1f1600 ffff88007c1f1600 ffff88007ca5dd38 ffffffff812cdb7e [ 1845.185026] 0000000000000000 ffff88007c1f1640 ffff88007ca5dd68 ffffffff812cdbfe [ 1845.185026] ffff88007c974800 ffff88007c1f1640 ffff88007ff61a00 0000000000000000 [ 1845.185026] Call Trace: [ 1845.185026] [<ffffffff812cdb7e>] kobject_del+0x2e/0x40 [ 1845.185026] [<ffffffff812cdbfe>] kobject_delayed_cleanup+0x6e/0x1d0 [ 1845.185026] [<ffffffff81063a45>] process_one_work+0x1e5/0x670 [ 1845.185026] [<ffffffff810639e3>] ? process_one_work+0x183/0x670 [ 1845.185026] [<ffffffff810642b3>] worker_thread+0x113/0x370 [ 1845.185026] [<ffffffff810641a0>] ? rescuer_thread+0x290/0x290 [ 1845.185026] [<ffffffff8106bfba>] kthread+0xda/0xe0 [ 1845.185026] [<ffffffff814ff0f0>] ? _raw_spin_unlock_irq+0x30/0x60 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] [<ffffffff8150751a>] ret_from_fork+0x7a/0xb0 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] Code: 81 48 c7 c7 28 95 ad 81 31 c0 e8 9b da 01 00 e9 4f ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1d <f6> 87 00 01 00 00 01 74 1e 48 8d 7b 38 83 6b 38 01 0f 94 c0 84 [ 1845.185026] RIP [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP <ffff88007ca5dd08> [ 1845.185026] CR2: ffffffffa01601d0 [ 1845.185026] ---[ end trace 49a70afd109f5653 ]--- Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-09-03 15:03:57 +08:00
mod_kobject_put(mod);
out:
return err;
}
static void mod_sysfs_fini(struct module *mod)
{
remove_notes_attrs(mod);
remove_sect_attrs(mod);
module: Fix mod->mkobj.kobj potentially freed too early DEBUG_KOBJECT_RELEASE helps to find the issue attached below. After some investigation, it seems the reason is: The mod->mkobj.kobj(ffffffffa01600d0 below) is freed together with mod itself in free_module(). However, its children still hold references to it, as the delay caused by DEBUG_KOBJECT_RELEASE. So when the child(holders below) tries to decrease the reference count to its parent in kobject_del(), BUG happens as it tries to access already freed memory. This patch tries to fix it by waiting for the mod->mkobj.kobj to be really released in the module removing process (and some error code paths). [ 1844.175287] kobject: 'holders' (ffff88007c1f1600): kobject_release, parent ffffffffa01600d0 (delayed) [ 1844.178991] kobject: 'notes' (ffff8800370b2a00): kobject_release, parent ffffffffa01600d0 (delayed) [ 1845.180118] kobject: 'holders' (ffff88007c1f1600): kobject_cleanup, parent ffffffffa01600d0 [ 1845.182130] kobject: 'holders' (ffff88007c1f1600): auto cleanup kobject_del [ 1845.184120] BUG: unable to handle kernel paging request at ffffffffa01601d0 [ 1845.185026] IP: [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] PGD 1a13067 PUD 1a14063 PMD 7bd30067 PTE 0 [ 1845.185026] Oops: 0000 [#1] PREEMPT [ 1845.185026] Modules linked in: xfs libcrc32c [last unloaded: kprobe_example] [ 1845.185026] CPU: 0 PID: 18 Comm: kworker/0:1 Tainted: G O 3.11.0-rc6-next-20130819+ #1 [ 1845.185026] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 1845.185026] Workqueue: events kobject_delayed_cleanup [ 1845.185026] task: ffff88007ca51f00 ti: ffff88007ca5c000 task.ti: ffff88007ca5c000 [ 1845.185026] RIP: 0010:[<ffffffff812cda81>] [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP: 0018:ffff88007ca5dd08 EFLAGS: 00010282 [ 1845.185026] RAX: 0000000000002000 RBX: ffffffffa01600d0 RCX: ffffffff8177d638 [ 1845.185026] RDX: ffff88007ca5dc18 RSI: 0000000000000000 RDI: ffffffffa01600d0 [ 1845.185026] RBP: ffff88007ca5dd18 R08: ffffffff824e9810 R09: ffffffffffffffff [ 1845.185026] R10: ffff8800ffffffff R11: dead4ead00000001 R12: ffffffff81a95040 [ 1845.185026] R13: ffff88007b27a960 R14: ffff88007c1f1600 R15: 0000000000000000 [ 1845.185026] FS: 0000000000000000(0000) GS:ffffffff81a23000(0000) knlGS:0000000000000000 [ 1845.185026] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1845.185026] CR2: ffffffffa01601d0 CR3: 0000000037207000 CR4: 00000000000006b0 [ 1845.185026] Stack: [ 1845.185026] ffff88007c1f1600 ffff88007c1f1600 ffff88007ca5dd38 ffffffff812cdb7e [ 1845.185026] 0000000000000000 ffff88007c1f1640 ffff88007ca5dd68 ffffffff812cdbfe [ 1845.185026] ffff88007c974800 ffff88007c1f1640 ffff88007ff61a00 0000000000000000 [ 1845.185026] Call Trace: [ 1845.185026] [<ffffffff812cdb7e>] kobject_del+0x2e/0x40 [ 1845.185026] [<ffffffff812cdbfe>] kobject_delayed_cleanup+0x6e/0x1d0 [ 1845.185026] [<ffffffff81063a45>] process_one_work+0x1e5/0x670 [ 1845.185026] [<ffffffff810639e3>] ? process_one_work+0x183/0x670 [ 1845.185026] [<ffffffff810642b3>] worker_thread+0x113/0x370 [ 1845.185026] [<ffffffff810641a0>] ? rescuer_thread+0x290/0x290 [ 1845.185026] [<ffffffff8106bfba>] kthread+0xda/0xe0 [ 1845.185026] [<ffffffff814ff0f0>] ? _raw_spin_unlock_irq+0x30/0x60 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] [<ffffffff8150751a>] ret_from_fork+0x7a/0xb0 [ 1845.185026] [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130 [ 1845.185026] Code: 81 48 c7 c7 28 95 ad 81 31 c0 e8 9b da 01 00 e9 4f ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1d <f6> 87 00 01 00 00 01 74 1e 48 8d 7b 38 83 6b 38 01 0f 94 c0 84 [ 1845.185026] RIP [<ffffffff812cda81>] kobject_put+0x11/0x60 [ 1845.185026] RSP <ffff88007ca5dd08> [ 1845.185026] CR2: ffffffffa01601d0 [ 1845.185026] ---[ end trace 49a70afd109f5653 ]--- Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-09-03 15:03:57 +08:00
mod_kobject_put(mod);
}
static void init_param_lock(struct module *mod)
{
mutex_init(&mod->param_lock);
}
#else /* !CONFIG_SYSFS */
static int mod_sysfs_setup(struct module *mod,
const struct load_info *info,
struct kernel_param *kparam,
unsigned int num_params)
{
return 0;
}
static void mod_sysfs_fini(struct module *mod)
{
}
static void module_remove_modinfo_attrs(struct module *mod)
{
}
static void del_usage_links(struct module *mod)
{
}
static void init_param_lock(struct module *mod)
{
}
#endif /* CONFIG_SYSFS */
static void mod_sysfs_teardown(struct module *mod)
{
del_usage_links(mod);
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
module_remove_modinfo_attrs(mod);
module_param_sysfs_remove(mod);
kobject_put(mod->mkobj.drivers_dir);
kobject_put(mod->holders_dir);
mod_sysfs_fini(mod);
}
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
#ifdef CONFIG_DEBUG_SET_MODULE_RONX
/*
* LKM RO/NX protection: protect module's text/ro-data
* from modification and any data from execution.
*
* General layout of module is:
* [text] [read-only-data] [writable data]
* text_size -----^ ^ ^
* ro_size ------------------------| |
* size -------------------------------------------|
*
* These values are always page-aligned (as is base)
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
*/
static void frob_text(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
set_memory((unsigned long)layout->base,
layout->text_size >> PAGE_SHIFT);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
}
static void frob_rodata(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
set_memory((unsigned long)layout->base + layout->text_size,
(layout->ro_size - layout->text_size) >> PAGE_SHIFT);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
}
static void frob_writable_data(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
set_memory((unsigned long)layout->base + layout->ro_size,
(layout->size - layout->ro_size) >> PAGE_SHIFT);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
}
/* livepatching wants to disable read-only so it can frob module. */
void module_disable_ro(const struct module *mod)
{
frob_text(&mod->core_layout, set_memory_rw);
frob_rodata(&mod->core_layout, set_memory_rw);
frob_text(&mod->init_layout, set_memory_rw);
frob_rodata(&mod->init_layout, set_memory_rw);
}
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
void module_enable_ro(const struct module *mod)
{
frob_text(&mod->core_layout, set_memory_ro);
frob_rodata(&mod->core_layout, set_memory_ro);
frob_text(&mod->init_layout, set_memory_ro);
frob_rodata(&mod->init_layout, set_memory_ro);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
}
static void module_enable_nx(const struct module *mod)
{
frob_rodata(&mod->core_layout, set_memory_nx);
frob_writable_data(&mod->core_layout, set_memory_nx);
frob_rodata(&mod->init_layout, set_memory_nx);
frob_writable_data(&mod->init_layout, set_memory_nx);
}
static void module_disable_nx(const struct module *mod)
{
frob_rodata(&mod->core_layout, set_memory_x);
frob_writable_data(&mod->core_layout, set_memory_x);
frob_rodata(&mod->init_layout, set_memory_x);
frob_writable_data(&mod->init_layout, set_memory_x);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
}
/* Iterate through all modules and set each module's text as RW */
void set_all_modules_text_rw(void)
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
{
struct module *mod;
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
frob_text(&mod->core_layout, set_memory_rw);
frob_text(&mod->init_layout, set_memory_rw);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
}
mutex_unlock(&module_mutex);
}
/* Iterate through all modules and set each module's text as RO */
void set_all_modules_text_ro(void)
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
{
struct module *mod;
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
frob_text(&mod->core_layout, set_memory_ro);
frob_text(&mod->init_layout, set_memory_ro);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
}
mutex_unlock(&module_mutex);
}
static void disable_ro_nx(const struct module_layout *layout)
{
frob_text(layout, set_memory_rw);
frob_rodata(layout, set_memory_rw);
frob_rodata(layout, set_memory_x);
frob_writable_data(layout, set_memory_x);
}
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
#else
static void disable_ro_nx(const struct module_layout *layout) { }
static void module_enable_nx(const struct module *mod) { }
static void module_disable_nx(const struct module *mod) { }
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
#endif
void __weak module_memfree(void *module_region)
{
vfree(module_region);
}
void __weak module_arch_cleanup(struct module *mod)
{
}
void __weak module_arch_freeing_init(struct module *mod)
{
}
/* Free a module, remove from lists, etc. */
static void free_module(struct module *mod)
{
tracing/events: Add module tracepoints Add trace points to trace module_load, module_free, module_get, module_put and module_request, and use trace_event facility to get the trace output. Here's the sample output: TASK-PID CPU# TIMESTAMP FUNCTION | | | | | <...>-42 [000] 1.758380: module_request: fb0 wait=1 call_site=fb_open ... <...>-60 [000] 3.269403: module_load: scsi_wait_scan <...>-60 [000] 3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0 <...>-61 [001] 3.273168: module_free: scsi_wait_scan ... <...>-1021 [000] 13.836081: module_load: sunrpc <...>-1021 [000] 13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1 <...>-1027 [000] 13.848098: module_get: sunrpc call_site=try_module_get refcnt=0 <...>-1027 [000] 13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1 <...>-1027 [000] 13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0 ... modprobe-2587 [001] 1088.437213: module_load: trace_events_sample F modprobe-2587 [001] 1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0 Note: - the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0 - the module refcnt is percpu, so it can be negative in a specific cpu Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-17 16:56:28 +08:00
trace_module_free(mod);
mod_sysfs_teardown(mod);
module: don't unlink the module until we've removed all exposure. Otherwise we get a race between unload and reload of the same module: the new module doesn't see the old one in the list, but then fails because it can't register over the still-extant entries in sysfs: [ 103.981925] ------------[ cut here ]------------ [ 103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0() [ 103.993606] Hardware name: CrownBay Platform [ 103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe' [ 104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe] [ 104.011362] Pid: 3021, comm: modprobe Tainted: G W 3.9.0-rc5+ #5 [ 104.018662] Call Trace: [ 104.021286] [<c103599d>] warn_slowpath_common+0x6d/0xa0 [ 104.026933] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.031986] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.037000] [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30 [ 104.042188] [<c1168c8b>] sysfs_add_one+0xab/0xd0 [ 104.046982] [<c1168dbe>] create_dir+0x5e/0xa0 [ 104.051633] [<c1168e78>] sysfs_create_dir+0x78/0xd0 [ 104.056774] [<c1262bc3>] kobject_add_internal+0x83/0x1f0 [ 104.062351] [<c126daf6>] ? kvasprintf+0x46/0x60 [ 104.067231] [<c1262ebd>] kobject_add_varg+0x2d/0x50 [ 104.072450] [<c1262f07>] kobject_init_and_add+0x27/0x30 [ 104.078075] [<c1089240>] mod_sysfs_setup+0x80/0x540 [ 104.083207] [<c1260851>] ? module_bug_finalize+0x51/0xc0 [ 104.088720] [<c108ab29>] load_module+0x1429/0x18b0 We can teardown sysfs first, then to be sure, put the state in MODULE_STATE_UNFORMED so it's ignored while we deconstruct it. Reported-by: Veaceslav Falico <vfalico@redhat.com> Tested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-17 11:50:03 +08:00
/* We leave it in list to prevent duplicate loads, but make sure
* that noone uses it while it's being deconstructed. */
modules, lock around setting of MODULE_STATE_UNFORMED A panic was seen in the following sitation. There are two threads running on the system. The first thread is a system monitoring thread that is reading /proc/modules. The second thread is loading and unloading a module (in this example I'm using my simple dummy-module.ko). Note, in the "real world" this occurred with the qlogic driver module. When doing this, the following panic occurred: ------------[ cut here ]------------ kernel BUG at kernel/module.c:3739! invalid opcode: 0000 [#1] SMP Modules linked in: binfmt_misc sg nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw igb gf128mul glue_helper iTCO_wdt iTCO_vendor_support ablk_helper ptp sb_edac cryptd pps_core edac_core shpchp i2c_i801 pcspkr wmi lpc_ich ioatdma mfd_core dca ipmi_si nfsd ipmi_msghandler auth_rpcgss nfs_acl lockd sunrpc xfs libcrc32c sr_mod cdrom sd_mod crc_t10dif crct10dif_common mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit drm_kms_helper ttm isci drm libsas ahci libahci scsi_transport_sas libata i2c_core dm_mirror dm_region_hash dm_log dm_mod [last unloaded: dummy_module] CPU: 37 PID: 186343 Comm: cat Tainted: GF O-------------- 3.10.0+ #7 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 task: ffff8807fd2d8000 ti: ffff88080fa7c000 task.ti: ffff88080fa7c000 RIP: 0010:[<ffffffff810d64c5>] [<ffffffff810d64c5>] module_flags+0xb5/0xc0 RSP: 0018:ffff88080fa7fe18 EFLAGS: 00010246 RAX: 0000000000000003 RBX: ffffffffa03b5200 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88080fa7fe38 RDI: ffffffffa03b5000 RBP: ffff88080fa7fe28 R08: 0000000000000010 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000000f R12: ffffffffa03b5000 R13: ffffffffa03b5008 R14: ffffffffa03b5200 R15: ffffffffa03b5000 FS: 00007f6ae57ef740(0000) GS:ffff88101e7a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000404f70 CR3: 0000000ffed48000 CR4: 00000000001407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffffa03b5200 ffff8810101e4800 ffff88080fa7fe70 ffffffff810d666c ffff88081e807300 000000002e0f2fbf 0000000000000000 ffff88100f257b00 ffffffffa03b5008 ffff88080fa7ff48 ffff8810101e4800 ffff88080fa7fee0 Call Trace: [<ffffffff810d666c>] m_show+0x19c/0x1e0 [<ffffffff811e4d7e>] seq_read+0x16e/0x3b0 [<ffffffff812281ed>] proc_reg_read+0x3d/0x80 [<ffffffff811c0f2c>] vfs_read+0x9c/0x170 [<ffffffff811c1a58>] SyS_read+0x58/0xb0 [<ffffffff81605829>] system_call_fastpath+0x16/0x1b Code: 48 63 c2 83 c2 01 c6 04 03 29 48 63 d2 eb d9 0f 1f 80 00 00 00 00 48 63 d2 c6 04 13 2d 41 8b 0c 24 8d 50 02 83 f9 01 75 b2 eb cb <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 RIP [<ffffffff810d64c5>] module_flags+0xb5/0xc0 RSP <ffff88080fa7fe18> Consider the two processes running on the system. CPU 0 (/proc/modules reader) CPU 1 (loading/unloading module) CPU 0 opens /proc/modules, and starts displaying data for each module by traversing the modules list via fs/seq_file.c:seq_open() and fs/seq_file.c:seq_read(). For each module in the modules list, seq_read does op->start() <-- this is a pointer to m_start() op->show() <- this is a pointer to m_show() op->stop() <-- this is a pointer to m_stop() The m_start(), m_show(), and m_stop() module functions are defined in kernel/module.c. The m_start() and m_stop() functions acquire and release the module_mutex respectively. ie) When reading /proc/modules, the module_mutex is acquired and released for each module. m_show() is called with the module_mutex held. It accesses the module struct data and attempts to write out module data. It is in this code path that the above BUG_ON() warning is encountered, specifically m_show() calls static char *module_flags(struct module *mod, char *buf) { int bx = 0; BUG_ON(mod->state == MODULE_STATE_UNFORMED); ... The other thread, CPU 1, in unloading the module calls the syscall delete_module() defined in kernel/module.c. The module_mutex is acquired for a short time, and then released. free_module() is called without the module_mutex. free_module() then sets mod->state = MODULE_STATE_UNFORMED, also without the module_mutex. Some additional code is called and then the module_mutex is reacquired to remove the module from the modules list: /* Now we can delete it from the lists */ mutex_lock(&module_mutex); stop_machine(__unlink_module, mod, NULL); mutex_unlock(&module_mutex); This is the sequence of events that leads to the panic. CPU 1 is removing dummy_module via delete_module(). It acquires the module_mutex, and then releases it. CPU 1 has NOT set dummy_module->state to MODULE_STATE_UNFORMED yet. CPU 0, which is reading the /proc/modules, acquires the module_mutex and acquires a pointer to the dummy_module which is still in the modules list. CPU 0 calls m_show for dummy_module. The check in m_show() for MODULE_STATE_UNFORMED passed for dummy_module even though it is being torn down. Meanwhile CPU 1, which has been continuing to remove dummy_module without holding the module_mutex, now calls free_module() and sets dummy_module->state to MODULE_STATE_UNFORMED. CPU 0 now calls module_flags() with dummy_module and ... static char *module_flags(struct module *mod, char *buf) { int bx = 0; BUG_ON(mod->state == MODULE_STATE_UNFORMED); and BOOM. Acquire and release the module_mutex lock around the setting of MODULE_STATE_UNFORMED in the teardown path, which should resolve the problem. Testing: In the unpatched kernel I can panic the system within 1 minute by doing while (true) do insmod dummy_module.ko; rmmod dummy_module.ko; done and while (true) do cat /proc/modules; done in separate terminals. In the patched kernel I was able to run just over one hour without seeing any issues. I also verified the output of panic via sysrq-c and the output of /proc/modules looks correct for all three states for the dummy_module. dummy_module 12661 0 - Unloading 0xffffffffa03a5000 (OE-) dummy_module 12661 0 - Live 0xffffffffa03bb000 (OE) dummy_module 14015 1 - Loading 0xffffffffa03a5000 (OE+) Signed-off-by: Prarit Bhargava <prarit@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2014-10-14 00:21:39 +08:00
mutex_lock(&module_mutex);
module: don't unlink the module until we've removed all exposure. Otherwise we get a race between unload and reload of the same module: the new module doesn't see the old one in the list, but then fails because it can't register over the still-extant entries in sysfs: [ 103.981925] ------------[ cut here ]------------ [ 103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0() [ 103.993606] Hardware name: CrownBay Platform [ 103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe' [ 104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe] [ 104.011362] Pid: 3021, comm: modprobe Tainted: G W 3.9.0-rc5+ #5 [ 104.018662] Call Trace: [ 104.021286] [<c103599d>] warn_slowpath_common+0x6d/0xa0 [ 104.026933] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.031986] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.037000] [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30 [ 104.042188] [<c1168c8b>] sysfs_add_one+0xab/0xd0 [ 104.046982] [<c1168dbe>] create_dir+0x5e/0xa0 [ 104.051633] [<c1168e78>] sysfs_create_dir+0x78/0xd0 [ 104.056774] [<c1262bc3>] kobject_add_internal+0x83/0x1f0 [ 104.062351] [<c126daf6>] ? kvasprintf+0x46/0x60 [ 104.067231] [<c1262ebd>] kobject_add_varg+0x2d/0x50 [ 104.072450] [<c1262f07>] kobject_init_and_add+0x27/0x30 [ 104.078075] [<c1089240>] mod_sysfs_setup+0x80/0x540 [ 104.083207] [<c1260851>] ? module_bug_finalize+0x51/0xc0 [ 104.088720] [<c108ab29>] load_module+0x1429/0x18b0 We can teardown sysfs first, then to be sure, put the state in MODULE_STATE_UNFORMED so it's ignored while we deconstruct it. Reported-by: Veaceslav Falico <vfalico@redhat.com> Tested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-17 11:50:03 +08:00
mod->state = MODULE_STATE_UNFORMED;
modules, lock around setting of MODULE_STATE_UNFORMED A panic was seen in the following sitation. There are two threads running on the system. The first thread is a system monitoring thread that is reading /proc/modules. The second thread is loading and unloading a module (in this example I'm using my simple dummy-module.ko). Note, in the "real world" this occurred with the qlogic driver module. When doing this, the following panic occurred: ------------[ cut here ]------------ kernel BUG at kernel/module.c:3739! invalid opcode: 0000 [#1] SMP Modules linked in: binfmt_misc sg nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel lrw igb gf128mul glue_helper iTCO_wdt iTCO_vendor_support ablk_helper ptp sb_edac cryptd pps_core edac_core shpchp i2c_i801 pcspkr wmi lpc_ich ioatdma mfd_core dca ipmi_si nfsd ipmi_msghandler auth_rpcgss nfs_acl lockd sunrpc xfs libcrc32c sr_mod cdrom sd_mod crc_t10dif crct10dif_common mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit drm_kms_helper ttm isci drm libsas ahci libahci scsi_transport_sas libata i2c_core dm_mirror dm_region_hash dm_log dm_mod [last unloaded: dummy_module] CPU: 37 PID: 186343 Comm: cat Tainted: GF O-------------- 3.10.0+ #7 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 task: ffff8807fd2d8000 ti: ffff88080fa7c000 task.ti: ffff88080fa7c000 RIP: 0010:[<ffffffff810d64c5>] [<ffffffff810d64c5>] module_flags+0xb5/0xc0 RSP: 0018:ffff88080fa7fe18 EFLAGS: 00010246 RAX: 0000000000000003 RBX: ffffffffa03b5200 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88080fa7fe38 RDI: ffffffffa03b5000 RBP: ffff88080fa7fe28 R08: 0000000000000010 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000000f R12: ffffffffa03b5000 R13: ffffffffa03b5008 R14: ffffffffa03b5200 R15: ffffffffa03b5000 FS: 00007f6ae57ef740(0000) GS:ffff88101e7a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000404f70 CR3: 0000000ffed48000 CR4: 00000000001407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffffffffa03b5200 ffff8810101e4800 ffff88080fa7fe70 ffffffff810d666c ffff88081e807300 000000002e0f2fbf 0000000000000000 ffff88100f257b00 ffffffffa03b5008 ffff88080fa7ff48 ffff8810101e4800 ffff88080fa7fee0 Call Trace: [<ffffffff810d666c>] m_show+0x19c/0x1e0 [<ffffffff811e4d7e>] seq_read+0x16e/0x3b0 [<ffffffff812281ed>] proc_reg_read+0x3d/0x80 [<ffffffff811c0f2c>] vfs_read+0x9c/0x170 [<ffffffff811c1a58>] SyS_read+0x58/0xb0 [<ffffffff81605829>] system_call_fastpath+0x16/0x1b Code: 48 63 c2 83 c2 01 c6 04 03 29 48 63 d2 eb d9 0f 1f 80 00 00 00 00 48 63 d2 c6 04 13 2d 41 8b 0c 24 8d 50 02 83 f9 01 75 b2 eb cb <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 RIP [<ffffffff810d64c5>] module_flags+0xb5/0xc0 RSP <ffff88080fa7fe18> Consider the two processes running on the system. CPU 0 (/proc/modules reader) CPU 1 (loading/unloading module) CPU 0 opens /proc/modules, and starts displaying data for each module by traversing the modules list via fs/seq_file.c:seq_open() and fs/seq_file.c:seq_read(). For each module in the modules list, seq_read does op->start() <-- this is a pointer to m_start() op->show() <- this is a pointer to m_show() op->stop() <-- this is a pointer to m_stop() The m_start(), m_show(), and m_stop() module functions are defined in kernel/module.c. The m_start() and m_stop() functions acquire and release the module_mutex respectively. ie) When reading /proc/modules, the module_mutex is acquired and released for each module. m_show() is called with the module_mutex held. It accesses the module struct data and attempts to write out module data. It is in this code path that the above BUG_ON() warning is encountered, specifically m_show() calls static char *module_flags(struct module *mod, char *buf) { int bx = 0; BUG_ON(mod->state == MODULE_STATE_UNFORMED); ... The other thread, CPU 1, in unloading the module calls the syscall delete_module() defined in kernel/module.c. The module_mutex is acquired for a short time, and then released. free_module() is called without the module_mutex. free_module() then sets mod->state = MODULE_STATE_UNFORMED, also without the module_mutex. Some additional code is called and then the module_mutex is reacquired to remove the module from the modules list: /* Now we can delete it from the lists */ mutex_lock(&module_mutex); stop_machine(__unlink_module, mod, NULL); mutex_unlock(&module_mutex); This is the sequence of events that leads to the panic. CPU 1 is removing dummy_module via delete_module(). It acquires the module_mutex, and then releases it. CPU 1 has NOT set dummy_module->state to MODULE_STATE_UNFORMED yet. CPU 0, which is reading the /proc/modules, acquires the module_mutex and acquires a pointer to the dummy_module which is still in the modules list. CPU 0 calls m_show for dummy_module. The check in m_show() for MODULE_STATE_UNFORMED passed for dummy_module even though it is being torn down. Meanwhile CPU 1, which has been continuing to remove dummy_module without holding the module_mutex, now calls free_module() and sets dummy_module->state to MODULE_STATE_UNFORMED. CPU 0 now calls module_flags() with dummy_module and ... static char *module_flags(struct module *mod, char *buf) { int bx = 0; BUG_ON(mod->state == MODULE_STATE_UNFORMED); and BOOM. Acquire and release the module_mutex lock around the setting of MODULE_STATE_UNFORMED in the teardown path, which should resolve the problem. Testing: In the unpatched kernel I can panic the system within 1 minute by doing while (true) do insmod dummy_module.ko; rmmod dummy_module.ko; done and while (true) do cat /proc/modules; done in separate terminals. In the patched kernel I was able to run just over one hour without seeing any issues. I also verified the output of panic via sysrq-c and the output of /proc/modules looks correct for all three states for the dummy_module. dummy_module 12661 0 - Unloading 0xffffffffa03a5000 (OE-) dummy_module 12661 0 - Live 0xffffffffa03bb000 (OE) dummy_module 14015 1 - Loading 0xffffffffa03a5000 (OE+) Signed-off-by: Prarit Bhargava <prarit@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2014-10-14 00:21:39 +08:00
mutex_unlock(&module_mutex);
module: don't unlink the module until we've removed all exposure. Otherwise we get a race between unload and reload of the same module: the new module doesn't see the old one in the list, but then fails because it can't register over the still-extant entries in sysfs: [ 103.981925] ------------[ cut here ]------------ [ 103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0() [ 103.993606] Hardware name: CrownBay Platform [ 103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe' [ 104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe] [ 104.011362] Pid: 3021, comm: modprobe Tainted: G W 3.9.0-rc5+ #5 [ 104.018662] Call Trace: [ 104.021286] [<c103599d>] warn_slowpath_common+0x6d/0xa0 [ 104.026933] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.031986] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.037000] [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30 [ 104.042188] [<c1168c8b>] sysfs_add_one+0xab/0xd0 [ 104.046982] [<c1168dbe>] create_dir+0x5e/0xa0 [ 104.051633] [<c1168e78>] sysfs_create_dir+0x78/0xd0 [ 104.056774] [<c1262bc3>] kobject_add_internal+0x83/0x1f0 [ 104.062351] [<c126daf6>] ? kvasprintf+0x46/0x60 [ 104.067231] [<c1262ebd>] kobject_add_varg+0x2d/0x50 [ 104.072450] [<c1262f07>] kobject_init_and_add+0x27/0x30 [ 104.078075] [<c1089240>] mod_sysfs_setup+0x80/0x540 [ 104.083207] [<c1260851>] ? module_bug_finalize+0x51/0xc0 [ 104.088720] [<c108ab29>] load_module+0x1429/0x18b0 We can teardown sysfs first, then to be sure, put the state in MODULE_STATE_UNFORMED so it's ignored while we deconstruct it. Reported-by: Veaceslav Falico <vfalico@redhat.com> Tested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-17 11:50:03 +08:00
/* Remove dynamic debug info */
ddebug_remove_module(mod->name);
/* Arch-specific cleanup. */
module_arch_cleanup(mod);
/* Module unload stuff */
module_unload_free(mod);
/* Free any allocated parameters. */
destroy_params(mod->kp, mod->num_kp);
module: don't unlink the module until we've removed all exposure. Otherwise we get a race between unload and reload of the same module: the new module doesn't see the old one in the list, but then fails because it can't register over the still-extant entries in sysfs: [ 103.981925] ------------[ cut here ]------------ [ 103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0() [ 103.993606] Hardware name: CrownBay Platform [ 103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe' [ 104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe] [ 104.011362] Pid: 3021, comm: modprobe Tainted: G W 3.9.0-rc5+ #5 [ 104.018662] Call Trace: [ 104.021286] [<c103599d>] warn_slowpath_common+0x6d/0xa0 [ 104.026933] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.031986] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.037000] [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30 [ 104.042188] [<c1168c8b>] sysfs_add_one+0xab/0xd0 [ 104.046982] [<c1168dbe>] create_dir+0x5e/0xa0 [ 104.051633] [<c1168e78>] sysfs_create_dir+0x78/0xd0 [ 104.056774] [<c1262bc3>] kobject_add_internal+0x83/0x1f0 [ 104.062351] [<c126daf6>] ? kvasprintf+0x46/0x60 [ 104.067231] [<c1262ebd>] kobject_add_varg+0x2d/0x50 [ 104.072450] [<c1262f07>] kobject_init_and_add+0x27/0x30 [ 104.078075] [<c1089240>] mod_sysfs_setup+0x80/0x540 [ 104.083207] [<c1260851>] ? module_bug_finalize+0x51/0xc0 [ 104.088720] [<c108ab29>] load_module+0x1429/0x18b0 We can teardown sysfs first, then to be sure, put the state in MODULE_STATE_UNFORMED so it's ignored while we deconstruct it. Reported-by: Veaceslav Falico <vfalico@redhat.com> Tested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-17 11:50:03 +08:00
/* Now we can delete it from the lists */
mutex_lock(&module_mutex);
/* Unlink carefully: kallsyms could be walking list. */
list_del_rcu(&mod->list);
mod_tree_remove(mod);
/* Remove this module from bug list, this uses list_del_rcu */
module_bug_cleanup(mod);
/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
synchronize_sched();
module: don't unlink the module until we've removed all exposure. Otherwise we get a race between unload and reload of the same module: the new module doesn't see the old one in the list, but then fails because it can't register over the still-extant entries in sysfs: [ 103.981925] ------------[ cut here ]------------ [ 103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0() [ 103.993606] Hardware name: CrownBay Platform [ 103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe' [ 104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe] [ 104.011362] Pid: 3021, comm: modprobe Tainted: G W 3.9.0-rc5+ #5 [ 104.018662] Call Trace: [ 104.021286] [<c103599d>] warn_slowpath_common+0x6d/0xa0 [ 104.026933] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.031986] [<c1168c8b>] ? sysfs_add_one+0xab/0xd0 [ 104.037000] [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30 [ 104.042188] [<c1168c8b>] sysfs_add_one+0xab/0xd0 [ 104.046982] [<c1168dbe>] create_dir+0x5e/0xa0 [ 104.051633] [<c1168e78>] sysfs_create_dir+0x78/0xd0 [ 104.056774] [<c1262bc3>] kobject_add_internal+0x83/0x1f0 [ 104.062351] [<c126daf6>] ? kvasprintf+0x46/0x60 [ 104.067231] [<c1262ebd>] kobject_add_varg+0x2d/0x50 [ 104.072450] [<c1262f07>] kobject_init_and_add+0x27/0x30 [ 104.078075] [<c1089240>] mod_sysfs_setup+0x80/0x540 [ 104.083207] [<c1260851>] ? module_bug_finalize+0x51/0xc0 [ 104.088720] [<c108ab29>] load_module+0x1429/0x18b0 We can teardown sysfs first, then to be sure, put the state in MODULE_STATE_UNFORMED so it's ignored while we deconstruct it. Reported-by: Veaceslav Falico <vfalico@redhat.com> Tested-by: Veaceslav Falico <vfalico@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-04-17 11:50:03 +08:00
mutex_unlock(&module_mutex);
/* This may be empty, but that's OK */
disable_ro_nx(&mod->init_layout);
module_arch_freeing_init(mod);
module_memfree(mod->init_layout.base);
kfree(mod->args);
percpu_modfree(mod);
/* Free lock-classes; relies on the preceding sync_rcu(). */
lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
[PATCH] lockdep: core Do 'make oldconfig' and accept all the defaults for new config options - reboot into the kernel and if everything goes well it should boot up fine and you should have /proc/lockdep and /proc/lockdep_stats files. Typically if the lock validator finds some problem it will print out voluminous debug output that begins with "BUG: ..." and which syslog output can be used by kernel developers to figure out the precise locking scenario. What does the lock validator do? It "observes" and maps all locking rules as they occur dynamically (as triggered by the kernel's natural use of spinlocks, rwlocks, mutexes and rwsems). Whenever the lock validator subsystem detects a new locking scenario, it validates this new rule against the existing set of rules. If this new rule is consistent with the existing set of rules then the new rule is added transparently and the kernel continues as normal. If the new rule could create a deadlock scenario then this condition is printed out. When determining validity of locking, all possible "deadlock scenarios" are considered: assuming arbitrary number of CPUs, arbitrary irq context and task context constellations, running arbitrary combinations of all the existing locking scenarios. In a typical system this means millions of separate scenarios. This is why we call it a "locking correctness" validator - for all rules that are observed the lock validator proves it with mathematical certainty that a deadlock could not occur (assuming that the lock validator implementation itself is correct and its internal data structures are not corrupted by some other kernel subsystem). [see more details and conditionals of this statement in include/linux/lockdep.h and Documentation/lockdep-design.txt] Furthermore, this "all possible scenarios" property of the validator also enables the finding of complex, highly unlikely multi-CPU multi-context races via single single-context rules, increasing the likelyhood of finding bugs drastically. In practical terms: the lock validator already found a bug in the upstream kernel that could only occur on systems with 3 or more CPUs, and which needed 3 very unlikely code sequences to occur at once on the 3 CPUs. That bug was found and reported on a single-CPU system (!). So in essence a race will be found "piecemail-wise", triggering all the necessary components for the race, without having to reproduce the race scenario itself! In its short existence the lock validator found and reported many bugs before they actually caused a real deadlock. To further increase the efficiency of the validator, the mapping is not per "lock instance", but per "lock-class". For example, all struct inode objects in the kernel have inode->inotify_mutex. If there are 10,000 inodes cached, then there are 10,000 lock objects. But ->inotify_mutex is a single "lock type", and all locking activities that occur against ->inotify_mutex are "unified" into this single lock-class. The advantage of the lock-class approach is that all historical ->inotify_mutex uses are mapped into a single (and as narrow as possible) set of locking rules - regardless of how many different tasks or inode structures it took to build this set of rules. The set of rules persist during the lifetime of the kernel. To see the rough magnitude of checking that the lock validator does, here's a portion of /proc/lockdep_stats, fresh after bootup: lock-classes: 694 [max: 2048] direct dependencies: 1598 [max: 8192] indirect dependencies: 17896 all direct dependencies: 16206 dependency chains: 1910 [max: 8192] in-hardirq chains: 17 in-softirq chains: 105 in-process chains: 1065 stack-trace entries: 38761 [max: 131072] combined max dependencies: 2033928 hardirq-safe locks: 24 hardirq-unsafe locks: 176 softirq-safe locks: 53 softirq-unsafe locks: 137 irq-safe locks: 59 irq-unsafe locks: 176 The lock validator has observed 1598 actual single-thread locking patterns, and has validated all possible 2033928 distinct locking scenarios. More details about the design of the lock validator can be found in Documentation/lockdep-design.txt, which can also found at: http://redhat.com/~mingo/lockdep-patches/lockdep-design.txt [bunk@stusta.de: cleanups] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:24:50 +08:00
/* Finally, free the core (containing the module structure) */
disable_ro_nx(&mod->core_layout);
module_memfree(mod->core_layout.base);
#ifdef CONFIG_MPU
update_protections(current->mm);
#endif
}
void *__symbol_get(const char *symbol)
{
struct module *owner;
const struct kernel_symbol *sym;
preempt_disable();
sym = find_symbol(symbol, &owner, NULL, true, true);
if (sym && strong_try_module_get(owner))
sym = NULL;
preempt_enable();
return sym ? (void *)sym->value : NULL;
}
EXPORT_SYMBOL_GPL(__symbol_get);
/*
* Ensure that an exported symbol [global namespace] does not already exist
* in the kernel or in some other module's exported symbol table.
*
* You must hold the module_mutex.
*/
static int verify_export_symbols(struct module *mod)
{
unsigned int i;
struct module *owner;
const struct kernel_symbol *s;
struct {
const struct kernel_symbol *sym;
unsigned int num;
} arr[] = {
{ mod->syms, mod->num_syms },
{ mod->gpl_syms, mod->num_gpl_syms },
{ mod->gpl_future_syms, mod->num_gpl_future_syms },
#ifdef CONFIG_UNUSED_SYMBOLS
{ mod->unused_syms, mod->num_unused_syms },
{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
#endif
};
for (i = 0; i < ARRAY_SIZE(arr); i++) {
for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
if (find_symbol(s->name, &owner, NULL, true, false)) {
pr_err("%s: exports duplicate symbol %s"
" (owned by %s)\n",
mod->name, s->name, module_name(owner));
return -ENOEXEC;
}
}
}
return 0;
}
/* Change all symbols so that st_value encodes the pointer directly. */
static int simplify_symbols(struct module *mod, const struct load_info *info)
{
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
Elf_Sym *sym = (void *)symsec->sh_addr;
unsigned long secbase;
unsigned int i;
int ret = 0;
const struct kernel_symbol *ksym;
for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
const char *name = info->strtab + sym[i].st_name;
switch (sym[i].st_shndx) {
case SHN_COMMON:
/* Ignore common symbols */
if (!strncmp(name, "__gnu_lto", 9))
break;
/* We compiled with -fno-common. These are not
supposed to happen. */
pr_debug("Common symbol: %s\n", name);
pr_warn("%s: please compile with -fno-common\n",
mod->name);
ret = -ENOEXEC;
break;
case SHN_ABS:
/* Don't need to do anything */
pr_debug("Absolute symbol: 0x%08lx\n",
(long)sym[i].st_value);
break;
case SHN_UNDEF:
ksym = resolve_symbol_wait(mod, info, name);
/* Ok if resolved. */
if (ksym && !IS_ERR(ksym)) {
sym[i].st_value = ksym->value;
break;
}
/* Ok if weak. */
if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
break;
pr_warn("%s: Unknown symbol %s (err %li)\n",
mod->name, name, PTR_ERR(ksym));
ret = PTR_ERR(ksym) ?: -ENOENT;
break;
default:
/* Divert to percpu allocation if a percpu var. */
if (sym[i].st_shndx == info->index.pcpu)
secbase = (unsigned long)mod_percpu(mod);
else
secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
sym[i].st_value += secbase;
break;
}
}
return ret;
}
static int apply_relocations(struct module *mod, const struct load_info *info)
{
unsigned int i;
int err = 0;
/* Now do relocations. */
for (i = 1; i < info->hdr->e_shnum; i++) {
unsigned int infosec = info->sechdrs[i].sh_info;
/* Not a valid relocation section? */
if (infosec >= info->hdr->e_shnum)
continue;
/* Don't bother with non-allocated sections */
if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
continue;
if (info->sechdrs[i].sh_type == SHT_REL)
err = apply_relocate(info->sechdrs, info->strtab,
info->index.sym, i, mod);
else if (info->sechdrs[i].sh_type == SHT_RELA)
err = apply_relocate_add(info->sechdrs, info->strtab,
info->index.sym, i, mod);
if (err < 0)
break;
}
return err;
}
/* Additional bytes needed by arch in front of individual sections */
unsigned int __weak arch_mod_section_prepend(struct module *mod,
unsigned int section)
{
/* default implementation just returns zero */
return 0;
}
/* Update size with this section: return offset. */
static long get_offset(struct module *mod, unsigned int *size,
Elf_Shdr *sechdr, unsigned int section)
{
long ret;
*size += arch_mod_section_prepend(mod, section);
ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
*size = ret + sechdr->sh_size;
return ret;
}
/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
might -- code, read-only data, read-write data, small data. Tally
sizes, and place the offsets into sh_entsize fields: high bit means it
belongs in init. */
static void layout_sections(struct module *mod, struct load_info *info)
{
static unsigned long const masks[][2] = {
/* NOTE: all executable code must be the first section
* in this array; otherwise modify the text_size
* finder in the two loops below */
{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
};
unsigned int m, i;
for (i = 0; i < info->hdr->e_shnum; i++)
info->sechdrs[i].sh_entsize = ~0UL;
pr_debug("Core section allocation order:\n");
for (m = 0; m < ARRAY_SIZE(masks); ++m) {
for (i = 0; i < info->hdr->e_shnum; ++i) {
Elf_Shdr *s = &info->sechdrs[i];
const char *sname = info->secstrings + s->sh_name;
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
|| strstarts(sname, ".init"))
continue;
s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
pr_debug("\t%s\n", sname);
}
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
switch (m) {
case 0: /* executable */
mod->core_layout.size = debug_align(mod->core_layout.size);
mod->core_layout.text_size = mod->core_layout.size;
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
break;
case 1: /* RO: text and ro-data */
mod->core_layout.size = debug_align(mod->core_layout.size);
mod->core_layout.ro_size = mod->core_layout.size;
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
break;
case 3: /* whole core */
mod->core_layout.size = debug_align(mod->core_layout.size);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
break;
}
}
pr_debug("Init section allocation order:\n");
for (m = 0; m < ARRAY_SIZE(masks); ++m) {
for (i = 0; i < info->hdr->e_shnum; ++i) {
Elf_Shdr *s = &info->sechdrs[i];
const char *sname = info->secstrings + s->sh_name;
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
|| !strstarts(sname, ".init"))
continue;
s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
| INIT_OFFSET_MASK);
pr_debug("\t%s\n", sname);
}
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
switch (m) {
case 0: /* executable */
mod->init_layout.size = debug_align(mod->init_layout.size);
mod->init_layout.text_size = mod->init_layout.size;
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
break;
case 1: /* RO: text and ro-data */
mod->init_layout.size = debug_align(mod->init_layout.size);
mod->init_layout.ro_size = mod->init_layout.size;
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
break;
case 3: /* whole init */
mod->init_layout.size = debug_align(mod->init_layout.size);
x86: Add RO/NX protection for loadable kernel modules This patch is a logical extension of the protection provided by CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting module_core and module_init into three logical parts each and setting appropriate page access permissions for each individual section: 1. Code: RO+X 2. RO data: RO+NX 3. RW data: RW+NX In order to achieve proper protection, layout_sections() have been modified to align each of the three parts mentioned above onto page boundary. Next, the corresponding page access permissions are set right before successful exit from load_module(). Further, free_module() and sys_init_module have been modified to set module_core and module_init as RW+NX right before calling module_free(). By default, the original section layout and access flags are preserved. When compiled with CONFIG_DEBUG_SET_MODULE_RONX=y, the patch will page-align each group of sections to ensure that each page contains only one type of content and will enforce RO/NX for each group of pages. -v1: Initial proof-of-concept patch. -v2: The patch have been re-written to reduce the number of #ifdefs and to make it architecture-agnostic. Code formatting has also been corrected. -v3: Opportunistic RO/NX protection is now unconditional. Section page-alignment is enabled when CONFIG_DEBUG_RODATA=y. -v4: Removed most macros and improved coding style. -v5: Changed page-alignment and RO/NX section size calculation -v6: Fixed comments. Restricted RO/NX enforcement to x86 only -v7: Introduced CONFIG_DEBUG_SET_MODULE_RONX, added calls to set_all_modules_text_rw() and set_all_modules_text_ro() in ftrace -v8: updated for compatibility with linux 2.6.33-rc5 -v9: coding style fixes -v10: more coding style fixes -v11: minor adjustments for -tip -v12: minor adjustments for v2.6.35-rc2-tip -v13: minor adjustments for v2.6.37-rc1-tip Signed-off-by: Siarhei Liakh <sliakh.lkml@gmail.com> Signed-off-by: Xuxian Jiang <jiang@cs.ncsu.edu> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Andi Kleen <ak@muc.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Dave Jones <davej@redhat.com> Cc: Kees Cook <kees.cook@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <4CE2F914.9070106@free.fr> [ minor cleanliness edits, -v14: build failure fix ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-17 05:35:16 +08:00
break;
}
}
}
static void set_license(struct module *mod, const char *license)
{
if (!license)
license = "unspecified";
if (!license_is_gpl_compatible(license)) {
if (!test_taint(TAINT_PROPRIETARY_MODULE))
pr_warn("%s: module license '%s' taints kernel.\n",
mod->name, license);
add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
LOCKDEP_NOW_UNRELIABLE);
}
}
/* Parse tag=value strings from .modinfo section */
static char *next_string(char *string, unsigned long *secsize)
{
/* Skip non-zero chars */
while (string[0]) {
string++;
if ((*secsize)-- <= 1)
return NULL;
}
/* Skip any zero padding. */
while (!string[0]) {
string++;
if ((*secsize)-- <= 1)
return NULL;
}
return string;
}
static char *get_modinfo(struct load_info *info, const char *tag)
{
char *p;
unsigned int taglen = strlen(tag);
Elf_Shdr *infosec = &info->sechdrs[info->index.info];
unsigned long size = infosec->sh_size;
for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
return p + taglen + 1;
}
return NULL;
}
static void setup_modinfo(struct module *mod, struct load_info *info)
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
{
struct module_attribute *attr;
int i;
for (i = 0; (attr = modinfo_attrs[i]); i++) {
if (attr->setup)
attr->setup(mod, get_modinfo(info, attr->attr.name));
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
}
}
static void free_modinfo(struct module *mod)
{
struct module_attribute *attr;
int i;
for (i = 0; (attr = modinfo_attrs[i]); i++) {
if (attr->free)
attr->free(mod);
}
}
#ifdef CONFIG_KALLSYMS
/* lookup symbol in given range of kernel_symbols */
static const struct kernel_symbol *lookup_symbol(const char *name,
const struct kernel_symbol *start,
const struct kernel_symbol *stop)
{
return bsearch(name, start, stop - start,
sizeof(struct kernel_symbol), cmp_name);
}
static int is_exported(const char *name, unsigned long value,
const struct module *mod)
{
const struct kernel_symbol *ks;
if (!mod)
ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
else
ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
return ks != NULL && ks->value == value;
}
/* As per nm */
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
{
const Elf_Shdr *sechdrs = info->sechdrs;
if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
return 'v';
else
return 'w';
}
if (sym->st_shndx == SHN_UNDEF)
return 'U';
if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
return 'a';
if (sym->st_shndx >= SHN_LORESERVE)
return '?';
if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
return 't';
if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
&& sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
return 'r';
else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
return 'g';
else
return 'd';
}
if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
return 's';
else
return 'b';
}
if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
".debug")) {
return 'n';
}
return '?';
}
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
unsigned int shnum, unsigned int pcpundx)
{
const Elf_Shdr *sec;
if (src->st_shndx == SHN_UNDEF
|| src->st_shndx >= shnum
|| !src->st_name)
return false;
#ifdef CONFIG_KALLSYMS_ALL
if (src->st_shndx == pcpundx)
return true;
#endif
sec = sechdrs + src->st_shndx;
if (!(sec->sh_flags & SHF_ALLOC)
#ifndef CONFIG_KALLSYMS_ALL
|| !(sec->sh_flags & SHF_EXECINSTR)
#endif
|| (sec->sh_entsize & INIT_OFFSET_MASK))
return false;
return true;
}
/*
* We only allocate and copy the strings needed by the parts of symtab
* we keep. This is simple, but has the effect of making multiple
* copies of duplicates. We could be more sophisticated, see
* linux-kernel thread starting with
* <73defb5e4bca04a6431392cc341112b1@localhost>.
*/
static void layout_symtab(struct module *mod, struct load_info *info)
{
Elf_Shdr *symsect = info->sechdrs + info->index.sym;
Elf_Shdr *strsect = info->sechdrs + info->index.str;
const Elf_Sym *src;
module: Remove a extra null character at the top of module->strtab. There is a extra null character('\0') at the top of module->strtab for each module. Commit 59ef28b introduced this bug and this patch fixes it. Live dump log of the current linus git kernel(HEAD is 2844a4870): ============================================================================ crash> mod | grep loop ffffffffa01db0a0 loop 16689 (not loaded) [CONFIG_KALLSYMS] crash> module.core_symtab ffffffffa01db0a0 core_symtab = 0xffffffffa01db320crash> rd 0xffffffffa01db320 12 ffffffffa01db320: 0000005500000001 0000000000000000 ....U........... ffffffffa01db330: 0000000000000000 0002007400000002 ............t... ffffffffa01db340: ffffffffa01d8000 0000000000000038 ........8....... ffffffffa01db350: 001a00640000000e ffffffffa01daeb0 ....d........... ffffffffa01db360: 00000000000000a0 0002007400000019 ............t... ffffffffa01db370: ffffffffa01d8068 000000000000001b h............... crash> module.core_strtab ffffffffa01db0a0 core_strtab = 0xffffffffa01dbb30 "" crash> rd 0xffffffffa01dbb30 4 ffffffffa01dbb30: 615f70616d6b0000 66780063696d6f74 ..kmap_atomic.xf ffffffffa01dbb40: 73636e75665f7265 72665f646e696600 er_funcs.find_fr ============================================================================ We expect Just first one byte of '\0', but actually first two bytes are '\0'. Here is The relationship between symtab and strtab. symtab_idx strtab_idx symbol ----------------------------------------------- 0 0x1 "\0" # startab_idx should be 0 1 0x2 "kmap_atomic" 2 0xe "xfer_funcs" 3 0x19 "find_fr..." By applying this patch, it becomes as follows. symtab_idx strtab_idx symbol ----------------------------------------------- 0 0x0 "\0" # extra byte is removed 1 0x1 "kmap_atomic" 2 0xd "xfer_funcs" 3 0x18 "find_fr..." Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Cc: Masaki Kimura <masaki.kimura.kz@hitachi.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-05 09:59:04 +08:00
unsigned int i, nsrc, ndst, strtab_size = 0;
/* Put symbol section at end of init part of module. */
symsect->sh_flags |= SHF_ALLOC;
symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
info->index.sym) | INIT_OFFSET_MASK;
pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
src = (void *)info->hdr + symsect->sh_offset;
nsrc = symsect->sh_size / sizeof(*src);
/* Compute total space required for the core symbols' strtab. */
for (ndst = i = 0; i < nsrc; i++) {
if (i == 0 ||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
info->index.pcpu)) {
strtab_size += strlen(&info->strtab[src[i].st_name])+1;
ndst++;
}
}
/* Append room for core symbols at end of core part. */
info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
mod->core_layout.size += strtab_size;
mod->core_layout.size = debug_align(mod->core_layout.size);
/* Put string table section at end of init part of module. */
strsect->sh_flags |= SHF_ALLOC;
strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
info->index.str) | INIT_OFFSET_MASK;
pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
/* We'll tack temporary mod_kallsyms on the end. */
mod->init_layout.size = ALIGN(mod->init_layout.size,
__alignof__(struct mod_kallsyms));
info->mod_kallsyms_init_off = mod->init_layout.size;
mod->init_layout.size += sizeof(struct mod_kallsyms);
mod->init_layout.size = debug_align(mod->init_layout.size);
}
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
/*
* We use the full symtab and strtab which layout_symtab arranged to
* be appended to the init section. Later we switch to the cut-down
* core-only ones.
*/
static void add_kallsyms(struct module *mod, const struct load_info *info)
{
unsigned int i, ndst;
const Elf_Sym *src;
Elf_Sym *dst;
char *s;
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
/* Set up to point into init section. */
mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
mod->kallsyms->symtab = (void *)symsec->sh_addr;
mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
/* Make sure we get permanent strtab: don't use info->strtab. */
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
/* Set types up while we still have access to sections. */
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
for (i = 0; i < mod->kallsyms->num_symtab; i++)
mod->kallsyms->symtab[i].st_info
= elf_type(&mod->kallsyms->symtab[i], info);
/* Now populate the cut down core kallsyms for after init. */
mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
src = mod->kallsyms->symtab;
for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
if (i == 0 ||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
info->index.pcpu)) {
dst[ndst] = src[i];
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
KSYM_NAME_LEN) + 1;
}
}
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
mod->core_kallsyms.num_symtab = ndst;
}
#else
static inline void layout_symtab(struct module *mod, struct load_info *info)
{
}
module: fix up CONFIG_KALLSYMS=n build. Starting from commit 4a4962263f07d14660849ec134ee42b63e95ea9a "reduce symbol table for loaded modules (v2)", the kernel/module.c build is broken with CONFIG_KALLSYMS disabled. CC kernel/module.o kernel/module.c:1995: warning: type defaults to 'int' in declaration of 'Elf_Hdr' kernel/module.c:1995: error: expected ';', ',' or ')' before '*' token kernel/module.c: In function 'load_module': kernel/module.c:2203: error: 'strmap' undeclared (first use in this function) kernel/module.c:2203: error: (Each undeclared identifier is reported only once kernel/module.c:2203: error: for each function it appears in.) kernel/module.c:2239: error: 'symoffs' undeclared (first use in this function) kernel/module.c:2239: error: implicit declaration of function 'layout_symtab' kernel/module.c:2240: error: 'stroffs' undeclared (first use in this function) make[1]: *** [kernel/module.o] Error 1 make: *** [kernel/module.o] Error 2 There are three different issues: - layout_symtab() takes a const Elf_Ehdr - layout_symtab() needs to return a value - symoffs/stroffs/strmap are referenced by the load_module() code despite being ifdefed out, which seems unnecessary given the noop behaviour of layout_symtab()/add_kallsyms() in the case of CONFIG_KALLSYMS=n. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Jan Beulich <jbeulich@novell.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-02 06:43:54 +08:00
static void add_kallsyms(struct module *mod, const struct load_info *info)
{
}
#endif /* CONFIG_KALLSYMS */
static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
driver core: basic infrastructure for per-module dynamic debug messages Base infrastructure to enable per-module debug messages. I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes control of debugging statements on a per-module basis in one /proc file, currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG, is not set, debugging statements can still be enabled as before, often by defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set. The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls can be dynamically enabled/disabled on a per-module basis. Future plans include extending this functionality to subsystems, that define their own debug levels and flags. Usage: Dynamic debugging is controlled by the debugfs file, <debugfs>/dynamic_printk/modules. This file contains a list of the modules that can be enabled. The format of the file is as follows: <module_name> <enabled=0/1> . . . <module_name> : Name of the module in which the debug call resides <enabled=0/1> : whether the messages are enabled or not For example: snd_hda_intel enabled=0 fixup enabled=1 driver enabled=0 Enable a module: $echo "set enabled=1 <module_name>" > dynamic_printk/modules Disable a module: $echo "set enabled=0 <module_name>" > dynamic_printk/modules Enable all modules: $echo "set enabled=1 all" > dynamic_printk/modules Disable all modules: $echo "set enabled=0 all" > dynamic_printk/modules Finally, passing "dynamic_printk" at the command line enables debugging for all modules. This mode can be turned off via the above disable command. [gkh: minor cleanups and tweaks to make the build work quietly] Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-13 04:46:19 +08:00
{
if (!debug)
return;
#ifdef CONFIG_DYNAMIC_DEBUG
if (ddebug_add_module(debug, num, debug->modname))
pr_err("dynamic debug error adding module: %s\n",
debug->modname);
#endif
}
driver core: basic infrastructure for per-module dynamic debug messages Base infrastructure to enable per-module debug messages. I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes control of debugging statements on a per-module basis in one /proc file, currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG, is not set, debugging statements can still be enabled as before, often by defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set. The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls can be dynamically enabled/disabled on a per-module basis. Future plans include extending this functionality to subsystems, that define their own debug levels and flags. Usage: Dynamic debugging is controlled by the debugfs file, <debugfs>/dynamic_printk/modules. This file contains a list of the modules that can be enabled. The format of the file is as follows: <module_name> <enabled=0/1> . . . <module_name> : Name of the module in which the debug call resides <enabled=0/1> : whether the messages are enabled or not For example: snd_hda_intel enabled=0 fixup enabled=1 driver enabled=0 Enable a module: $echo "set enabled=1 <module_name>" > dynamic_printk/modules Disable a module: $echo "set enabled=0 <module_name>" > dynamic_printk/modules Enable all modules: $echo "set enabled=1 all" > dynamic_printk/modules Disable all modules: $echo "set enabled=0 all" > dynamic_printk/modules Finally, passing "dynamic_printk" at the command line enables debugging for all modules. This mode can be turned off via the above disable command. [gkh: minor cleanups and tweaks to make the build work quietly] Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-13 04:46:19 +08:00
static void dynamic_debug_remove(struct _ddebug *debug)
{
if (debug)
ddebug_remove_module(debug->modname);
}
void * __weak module_alloc(unsigned long size)
{
return vmalloc_exec(size);
}
#ifdef CONFIG_DEBUG_KMEMLEAK
static void kmemleak_load_module(const struct module *mod,
const struct load_info *info)
{
unsigned int i;
/* only scan the sections containing data */
kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
for (i = 1; i < info->hdr->e_shnum; i++) {
/* Scan all writable sections that's not executable */
if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
!(info->sechdrs[i].sh_flags & SHF_WRITE) ||
(info->sechdrs[i].sh_flags & SHF_EXECINSTR))
continue;
kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
info->sechdrs[i].sh_size, GFP_KERNEL);
}
}
#else
static inline void kmemleak_load_module(const struct module *mod,
const struct load_info *info)
{
}
#endif
#ifdef CONFIG_MODULE_SIG
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
static int module_sig_check(struct load_info *info)
{
int err = -ENOKEY;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
const void *mod = info->hdr;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
if (info->len > markerlen &&
memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
/* We truncate the module to discard the signature */
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
info->len -= markerlen;
err = mod_verify_sig(mod, &info->len);
}
if (!err) {
info->sig_ok = true;
return 0;
}
/* Not having a signature is only an error if we're strict. */
if (err == -ENOKEY && !sig_enforce)
err = 0;
return err;
}
#else /* !CONFIG_MODULE_SIG */
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
static int module_sig_check(struct load_info *info)
{
return 0;
}
#endif /* !CONFIG_MODULE_SIG */
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
static int elf_header_check(struct load_info *info)
{
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
if (info->len < sizeof(*(info->hdr)))
return -ENOEXEC;
if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
|| info->hdr->e_type != ET_REL
|| !elf_check_arch(info->hdr)
|| info->hdr->e_shentsize != sizeof(Elf_Shdr))
return -ENOEXEC;
if (info->hdr->e_shoff >= info->len
|| (info->hdr->e_shnum * sizeof(Elf_Shdr) >
info->len - info->hdr->e_shoff))
return -ENOEXEC;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
return 0;
}
#define COPY_CHUNK_SIZE (16*PAGE_SIZE)
static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
{
do {
unsigned long n = min(len, COPY_CHUNK_SIZE);
if (copy_from_user(dst, usrc, n) != 0)
return -EFAULT;
cond_resched();
dst += n;
usrc += n;
len -= n;
} while (len);
return 0;
}
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
/* Sets info->hdr and info->len. */
static int copy_module_from_user(const void __user *umod, unsigned long len,
struct load_info *info)
{
int err;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
info->len = len;
if (info->len < sizeof(*(info->hdr)))
return -ENOEXEC;
err = security_kernel_read_file(NULL, READING_MODULE);
if (err)
return err;
/* Suck in entire file: we'll want most of it. */
info->hdr = __vmalloc(info->len,
GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
if (!info->hdr)
return -ENOMEM;
if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
vfree(info->hdr);
return -EFAULT;
}
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
return 0;
}
static void free_copy(struct load_info *info)
{
vfree(info->hdr);
}
static int rewrite_section_headers(struct load_info *info, int flags)
{
unsigned int i;
/* This should always be true, but let's be sure. */
info->sechdrs[0].sh_addr = 0;
for (i = 1; i < info->hdr->e_shnum; i++) {
Elf_Shdr *shdr = &info->sechdrs[i];
if (shdr->sh_type != SHT_NOBITS
&& info->len < shdr->sh_offset + shdr->sh_size) {
pr_err("Module len %lu truncated\n", info->len);
return -ENOEXEC;
}
/* Mark all sections sh_addr with their address in the
temporary image. */
shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
#ifndef CONFIG_MODULE_UNLOAD
/* Don't load .exit sections */
if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
#endif
}
/* Track but don't keep modinfo and version sections. */
if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
info->index.vers = 0; /* Pretend no __versions section! */
else
info->index.vers = find_sec(info, "__versions");
info->index.info = find_sec(info, ".modinfo");
info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
return 0;
}
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
/*
* Set up our basic convenience variables (pointers to section headers,
* search for module section index etc), and do some basic section
* verification.
*
* Return the temporary module pointer (we'll replace it with the final
* one when we move the module sections around).
*/
static struct module *setup_load_info(struct load_info *info, int flags)
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
{
unsigned int i;
int err;
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
struct module *mod;
/* Set up the convenience variables */
info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
info->secstrings = (void *)info->hdr
+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
err = rewrite_section_headers(info, flags);
if (err)
return ERR_PTR(err);
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
/* Find internal symbols and strings. */
for (i = 1; i < info->hdr->e_shnum; i++) {
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
info->index.sym = i;
info->index.str = info->sechdrs[i].sh_link;
info->strtab = (char *)info->hdr
+ info->sechdrs[info->index.str].sh_offset;
break;
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
}
}
info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
if (!info->index.mod) {
pr_warn("No module found in object\n");
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
return ERR_PTR(-ENOEXEC);
}
/* This is temporary: point mod into copy of data. */
mod = (void *)info->sechdrs[info->index.mod].sh_addr;
if (info->index.sym == 0) {
pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
return ERR_PTR(-ENOEXEC);
}
info->index.pcpu = find_pcpusec(info);
module: add load_info Btw, here's a patch that _looks_ large, but it really pretty trivial, and sets things up so that it would be way easier to split off pieces of the module loading. The reason it looks large is that it creates a "module_info" structure that contains all the module state that we're building up while loading, instead of having individual variables for all the indices etc. So the patch ends up being large, because every "symindex" access instead becomes "info.index.sym" etc. That may be a few characters longer, but it then means that we can just pass a pointer to that "info" structure around. and let all the pieces fill it in very naturally. As an example of that, the patch also moves the initialization of all those convenience variables into a "setup_module_info()" function. And at this point it really does become very natural to start to peel off some of the error labels and move them into the helper functions - now the "truncated" case is gone, and is handled inside that setup function instead. So maybe you don't like this approach, and it does make the variable accesses a bit longer, but I don't think unreadably so. And the patch really does look big and scary, but there really should be absolutely no semantic changes - most of it was a trivial and mindless rename. In fact, it was so mindless that I on purpose kept the existing helper functions looking like this: - err = check_modinfo(mod, sechdrs, infoindex, versindex); + err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers); rather than changing them to just take the "info" pointer. IOW, a second phase (if you think the approach is ok) would change that calling convention to just do err = check_modinfo(mod, &info); (and same for "layout_sections()", "layout_symtabs()" etc.) Similarly, while right now it makes things _look_ bigger, with things like this: versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); becoming info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions"); in the new "setup_module_info()" function, that's again just a result of it being a search-and-replace patch. By using the 'info' pointer, we could just change the 'find_sec()' interface so that it ends up being info->index.vers = find_sec(info, "__versions"); instead, and then we'd actually have a shorter and more readable line. So for a lot of those mindless variable name expansions there's would be room for separate cleanups. I didn't move quite everything in there - if we do this to layout_symtabs, for example, we'd want to move the percpu, symoffs, stroffs, *strmap variables to be fields in that module_info structure too. But that's a much smaller patch, I moved just the really core stuff that is currently being set up and used in various parts. But even in this rough form, it removes close to 70 lines from that function (but adds 22 lines overall, of course - the structure definition, the helper function declarations and call-sites etc etc). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-06-03 02:01:06 +08:00
/* Check module struct version now, before we try to use module. */
if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
return ERR_PTR(-ENOEXEC);
return mod;
}
static int check_modinfo(struct module *mod, struct load_info *info, int flags)
{
const char *modmagic = get_modinfo(info, "vermagic");
int err;
if (flags & MODULE_INIT_IGNORE_VERMAGIC)
modmagic = NULL;
/* This is allowed: modprobe --force will invalidate it. */
if (!modmagic) {
err = try_to_force_load(mod, "bad vermagic");
if (err)
return err;
} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
pr_err("%s: version magic '%s' should be '%s'\n",
mod->name, modmagic, vermagic);
return -ENOEXEC;
}
if (!get_modinfo(info, "intree"))
add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
if (get_modinfo(info, "staging")) {
add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
pr_warn("%s: module is from the staging directory, the quality "
"is unknown, you have been warned.\n", mod->name);
}
/* Set up license info based on the info section */
set_license(mod, get_modinfo(info, "license"));
return 0;
}
static int find_module_sections(struct module *mod, struct load_info *info)
{
mod->kp = section_objs(info, "__param",
sizeof(*mod->kp), &mod->num_kp);
mod->syms = section_objs(info, "__ksymtab",
sizeof(*mod->syms), &mod->num_syms);
mod->crcs = section_addr(info, "__kcrctab");
mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
sizeof(*mod->gpl_syms),
&mod->num_gpl_syms);
mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
mod->gpl_future_syms = section_objs(info,
"__ksymtab_gpl_future",
sizeof(*mod->gpl_future_syms),
&mod->num_gpl_future_syms);
mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
#ifdef CONFIG_UNUSED_SYMBOLS
mod->unused_syms = section_objs(info, "__ksymtab_unused",
sizeof(*mod->unused_syms),
&mod->num_unused_syms);
mod->unused_crcs = section_addr(info, "__kcrctab_unused");
mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
sizeof(*mod->unused_gpl_syms),
&mod->num_unused_gpl_syms);
mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
#endif
#ifdef CONFIG_CONSTRUCTORS
mod->ctors = section_objs(info, ".ctors",
sizeof(*mod->ctors), &mod->num_ctors);
if (!mod->ctors)
mod->ctors = section_objs(info, ".init_array",
sizeof(*mod->ctors), &mod->num_ctors);
else if (find_sec(info, ".init_array")) {
/*
* This shouldn't happen with same compiler and binutils
* building all parts of the module.
*/
pr_warn("%s: has both .ctors and .init_array.\n",
mod->name);
return -EINVAL;
}
#endif
#ifdef CONFIG_TRACEPOINTS
tracepoints: Fix section alignment using pointer array Make the tracepoints more robust, making them solid enough to handle compiler changes by not relying on anything based on compiler-specific behavior with respect to structure alignment. Implement an approach proposed by David Miller: use an array of const pointers to refer to the individual structures, and export this pointer array through the linker script rather than the structures per se. It will consume 32 extra bytes per tracepoint (24 for structure padding and 8 for the pointers), but are less likely to break due to compiler changes. History: commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. One attempt was to use a 8-byte alignment for tracepoint structures by applying both the variable and type attribute to tracepoint structures definitions and declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5. The reason is that the "aligned" attribute only specify the _minimum_ alignment for a structure, leaving both the compiler and the linker free to align on larger multiples. Because tracepoint.c expects the structures to be placed as an array within each section, up-alignment cause NULL-pointer exceptions due to the extra unexpected padding. (this patch applies on top of -tip) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> LKML-Reference: <20110126222622.GA10794@Krystal> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Thomas Gleixner <tglx@linutronix.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-01-27 06:26:22 +08:00
mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
sizeof(*mod->tracepoints_ptrs),
&mod->num_tracepoints);
#endif
#ifdef HAVE_JUMP_LABEL
mod->jump_entries = section_objs(info, "__jump_table",
sizeof(*mod->jump_entries),
&mod->num_jump_entries);
#endif
#ifdef CONFIG_EVENT_TRACING
mod->trace_events = section_objs(info, "_ftrace_events",
sizeof(*mod->trace_events),
&mod->num_trace_events);
mod->trace_enums = section_objs(info, "_ftrace_enum_map",
sizeof(*mod->trace_enums),
&mod->num_trace_enums);
#endif
tracing: Fix module use of trace_bprintk() On use of trace_printk() there's a macro that determines if the format is static or a variable. If it is static, it defaults to __trace_bprintk() otherwise it uses __trace_printk(). A while ago, Lai Jiangshan added __trace_bprintk(). In that patch, we discussed a way to allow modules to use it. The difference between __trace_bprintk() and __trace_printk() is that for faster processing, just the format and args are stored in the trace instead of running it through a sprintf function. In order to do this, the format used by the __trace_bprintk() had to be persistent. See commit 1ba28e02a18cbdbea123836f6c98efb09cbf59ec The problem comes with trace_bprintk() where the module is unloaded. The pointer left in the buffer is still pointing to the format. To solve this issue, the formats in the module were copied into kernel core. If the same format was used, they would use the same copy (to prevent memory leak). This all worked well until we tried to merge everything. At the time this was written, Lai Jiangshan, Frederic Weisbecker, Ingo Molnar and myself were all touching the same code. When this was merged, we lost the part of it that was in module.c. This kept out the copying of the formats and unloading the module could cause bad pointers left in the ring buffer. This patch adds back (with updates required for current kernel) the module code that sets up the necessary pointers. Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-11 11:19:24 +08:00
#ifdef CONFIG_TRACING
mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
sizeof(*mod->trace_bprintk_fmt_start),
&mod->num_trace_bprintk_fmt);
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
/* sechdrs[0].sh_size is always zero */
mod->ftrace_callsites = section_objs(info, "__mcount_loc",
sizeof(*mod->ftrace_callsites),
&mod->num_ftrace_callsites);
#endif
mod->extable = section_objs(info, "__ex_table",
sizeof(*mod->extable), &mod->num_exentries);
if (section_addr(info, "__obsparm"))
pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
info->debug = section_objs(info, "__verbose",
sizeof(*info->debug), &info->num_debug);
return 0;
}
static int move_module(struct module *mod, struct load_info *info)
{
int i;
void *ptr;
/* Do the allocs. */
ptr = module_alloc(mod->core_layout.size);
/*
* The pointer to this block is stored in the module structure
* which is inside the block. Just mark it as not being a
* leak.
*/
kmemleak_not_leak(ptr);
if (!ptr)
return -ENOMEM;
memset(ptr, 0, mod->core_layout.size);
mod->core_layout.base = ptr;
if (mod->init_layout.size) {
ptr = module_alloc(mod->init_layout.size);
/*
* The pointer to this block is stored in the module structure
* which is inside the block. This block doesn't need to be
* scanned as it contains data and code that will be freed
* after the module is initialized.
*/
kmemleak_ignore(ptr);
if (!ptr) {
module_memfree(mod->core_layout.base);
return -ENOMEM;
}
memset(ptr, 0, mod->init_layout.size);
mod->init_layout.base = ptr;
} else
mod->init_layout.base = NULL;
/* Transfer each section which specifies SHF_ALLOC */
pr_debug("final section addresses:\n");
for (i = 0; i < info->hdr->e_shnum; i++) {
void *dest;
Elf_Shdr *shdr = &info->sechdrs[i];
if (!(shdr->sh_flags & SHF_ALLOC))
continue;
if (shdr->sh_entsize & INIT_OFFSET_MASK)
dest = mod->init_layout.base
+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
else
dest = mod->core_layout.base + shdr->sh_entsize;
if (shdr->sh_type != SHT_NOBITS)
memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
/* Update sh_addr to point to copy in image. */
shdr->sh_addr = (unsigned long)dest;
pr_debug("\t0x%lx %s\n",
(long)shdr->sh_addr, info->secstrings + shdr->sh_name);
}
return 0;
}
static int check_module_license_and_versions(struct module *mod)
{
/*
* ndiswrapper is under GPL by itself, but loads proprietary modules.
* Don't use add_taint_module(), as it would prevent ndiswrapper from
* using GPL-only symbols it needs.
*/
if (strcmp(mod->name, "ndiswrapper") == 0)
add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
/* driverloader was caught wrongly pretending to be under GPL */
if (strcmp(mod->name, "driverloader") == 0)
add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
LOCKDEP_NOW_UNRELIABLE);
/* lve claims to be GPL but upstream won't provide source */
if (strcmp(mod->name, "lve") == 0)
add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
LOCKDEP_NOW_UNRELIABLE);
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !mod->crcs)
|| (mod->num_gpl_syms && !mod->gpl_crcs)
|| (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
#ifdef CONFIG_UNUSED_SYMBOLS
|| (mod->num_unused_syms && !mod->unused_crcs)
|| (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
#endif
) {
return try_to_force_load(mod,
"no versions for exported symbols");
}
#endif
return 0;
}
static void flush_module_icache(const struct module *mod)
{
mm_segment_t old_fs;
/* flush the icache in correct context */
old_fs = get_fs();
set_fs(KERNEL_DS);
/*
* Flush the instruction cache, since we've played with text.
* Do it before processing of module parameters, so the module
* can provide parameter accessor functions of its own.
*/
if (mod->init_layout.base)
flush_icache_range((unsigned long)mod->init_layout.base,
(unsigned long)mod->init_layout.base
+ mod->init_layout.size);
flush_icache_range((unsigned long)mod->core_layout.base,
(unsigned long)mod->core_layout.base + mod->core_layout.size);
set_fs(old_fs);
}
int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
char *secstrings,
struct module *mod)
{
return 0;
}
static struct module *layout_and_allocate(struct load_info *info, int flags)
{
/* Module within temporary copy. */
struct module *mod;
int err;
module: fix up CONFIG_KALLSYMS=n build. Starting from commit 4a4962263f07d14660849ec134ee42b63e95ea9a "reduce symbol table for loaded modules (v2)", the kernel/module.c build is broken with CONFIG_KALLSYMS disabled. CC kernel/module.o kernel/module.c:1995: warning: type defaults to 'int' in declaration of 'Elf_Hdr' kernel/module.c:1995: error: expected ';', ',' or ')' before '*' token kernel/module.c: In function 'load_module': kernel/module.c:2203: error: 'strmap' undeclared (first use in this function) kernel/module.c:2203: error: (Each undeclared identifier is reported only once kernel/module.c:2203: error: for each function it appears in.) kernel/module.c:2239: error: 'symoffs' undeclared (first use in this function) kernel/module.c:2239: error: implicit declaration of function 'layout_symtab' kernel/module.c:2240: error: 'stroffs' undeclared (first use in this function) make[1]: *** [kernel/module.o] Error 1 make: *** [kernel/module.o] Error 2 There are three different issues: - layout_symtab() takes a const Elf_Ehdr - layout_symtab() needs to return a value - symoffs/stroffs/strmap are referenced by the load_module() code despite being ifdefed out, which seems unnecessary given the noop behaviour of layout_symtab()/add_kallsyms() in the case of CONFIG_KALLSYMS=n. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Jan Beulich <jbeulich@novell.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-02 06:43:54 +08:00
mod = setup_load_info(info, flags);
if (IS_ERR(mod))
return mod;
err = check_modinfo(mod, info, flags);
if (err)
return ERR_PTR(err);
/* Allow arches to frob section contents and sizes. */
err = module_frob_arch_sections(info->hdr, info->sechdrs,
info->secstrings, mod);
if (err < 0)
return ERR_PTR(err);
/* We will do a special allocation for per-cpu sections later. */
info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
/* Determine total sizes, and put offsets in sh_entsize. For now
this is done generically; there doesn't appear to be any
special cases for the architectures. */
layout_sections(mod, info);
layout_symtab(mod, info);
/* Allocate and move to the final place */
err = move_module(mod, info);
if (err)
return ERR_PTR(err);
/* Module has been copied to its final place now: return it. */
mod = (void *)info->sechdrs[info->index.mod].sh_addr;
kmemleak_load_module(mod, info);
return mod;
}
/* mod is no longer valid after this! */
static void module_deallocate(struct module *mod, struct load_info *info)
{
percpu_modfree(mod);
module_arch_freeing_init(mod);
module_memfree(mod->init_layout.base);
module_memfree(mod->core_layout.base);
}
int __weak module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
return 0;
}
static int post_relocation(struct module *mod, const struct load_info *info)
{
/* Sort exception table now relocations are done. */
sort_extable(mod->extable, mod->extable + mod->num_exentries);
/* Copy relocated percpu area over. */
percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
info->sechdrs[info->index.pcpu].sh_size);
/* Setup kallsyms-specific fields. */
add_kallsyms(mod, info);
/* Arch-specific module finalizing. */
return module_finalize(info->hdr, info->sechdrs, mod);
}
/* Is this module of this name done loading? No locks held. */
static bool finished_loading(const char *name)
{
struct module *mod;
bool ret;
/*
* The module_mutex should not be a heavily contended lock;
* if we get the occasional sleep here, we'll go an extra iteration
* in the wait_event_interruptible(), which is harmless.
*/
sched_annotate_sleep();
mutex_lock(&module_mutex);
mod = find_module_all(name, strlen(name), true);
ret = !mod || mod->state == MODULE_STATE_LIVE
|| mod->state == MODULE_STATE_GOING;
mutex_unlock(&module_mutex);
return ret;
}
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
/* Call module constructors. */
static void do_mod_ctors(struct module *mod)
{
#ifdef CONFIG_CONSTRUCTORS
unsigned long i;
for (i = 0; i < mod->num_ctors; i++)
mod->ctors[i]();
#endif
}
/* For freeing module_init on success, in case kallsyms traversing */
struct mod_initfree {
struct rcu_head rcu;
void *module_init;
};
static void do_free_init(struct rcu_head *head)
{
struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
module_memfree(m->module_init);
kfree(m);
}
/*
* This is where the real work happens.
*
* Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
* helper command 'lx-symbols'.
*/
static noinline int do_init_module(struct module *mod)
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
{
int ret = 0;
struct mod_initfree *freeinit;
freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
if (!freeinit) {
ret = -ENOMEM;
goto fail;
}
freeinit->module_init = mod->init_layout.base;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
module, async: async_synchronize_full() on module init iff async is used If the default iosched is built as module, the kernel may deadlock while trying to load the iosched module on device probe if the probing was running off async. This is because async_synchronize_full() at the end of module init ends up waiting for the async job which initiated the module loading. async A modprobe 1. finds a device 2. registers the block device 3. request_module(default iosched) 4. modprobe in userland 5. load and init module 6. async_synchronize_full() Async A waits for modprobe to finish in request_module() and modprobe waits for async A to finish in async_synchronize_full(). Because there's no easy to track dependency once control goes out to userland, implementing properly nested flushing is difficult. For now, make module init perform async_synchronize_full() iff module init has queued async jobs as suggested by Linus. This avoids the described deadlock because iosched module doesn't use async and thus wouldn't invoke async_synchronize_full(). This is hacky and incomplete. It will deadlock if async module loading nests; however, this works around the known problem case and seems to be the best of bad options. For more details, please refer to the following thread. http://thread.gmane.org/gmane.linux.kernel/1420814 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Alex Riesen <raa.lkml@gmail.com> Tested-by: Ming Lei <ming.lei@canonical.com> Tested-by: Alex Riesen <raa.lkml@gmail.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-16 10:52:51 +08:00
/*
* We want to find out whether @mod uses async during init. Clear
* PF_USED_ASYNC. async_schedule*() will set it.
*/
current->flags &= ~PF_USED_ASYNC;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
do_mod_ctors(mod);
/* Start the module */
if (mod->init != NULL)
ret = do_one_initcall(mod->init);
if (ret < 0) {
goto fail_free_freeinit;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
}
if (ret > 0) {
pr_warn("%s: '%s'->init suspiciously returned %d, it should "
"follow 0/-E convention\n"
"%s: loading module anyway...\n",
__func__, mod->name, ret, __func__);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
dump_stack();
}
/* Now it's a first class citizen! */
mod->state = MODULE_STATE_LIVE;
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_LIVE, mod);
module, async: async_synchronize_full() on module init iff async is used If the default iosched is built as module, the kernel may deadlock while trying to load the iosched module on device probe if the probing was running off async. This is because async_synchronize_full() at the end of module init ends up waiting for the async job which initiated the module loading. async A modprobe 1. finds a device 2. registers the block device 3. request_module(default iosched) 4. modprobe in userland 5. load and init module 6. async_synchronize_full() Async A waits for modprobe to finish in request_module() and modprobe waits for async A to finish in async_synchronize_full(). Because there's no easy to track dependency once control goes out to userland, implementing properly nested flushing is difficult. For now, make module init perform async_synchronize_full() iff module init has queued async jobs as suggested by Linus. This avoids the described deadlock because iosched module doesn't use async and thus wouldn't invoke async_synchronize_full(). This is hacky and incomplete. It will deadlock if async module loading nests; however, this works around the known problem case and seems to be the best of bad options. For more details, please refer to the following thread. http://thread.gmane.org/gmane.linux.kernel/1420814 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Alex Riesen <raa.lkml@gmail.com> Tested-by: Ming Lei <ming.lei@canonical.com> Tested-by: Alex Riesen <raa.lkml@gmail.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-16 10:52:51 +08:00
/*
* We need to finish all async code before the module init sequence
* is done. This has potential to deadlock. For example, a newly
* detected block device can trigger request_module() of the
* default iosched from async probing task. Once userland helper
* reaches here, async_synchronize_full() will wait on the async
* task waiting on request_module() and deadlock.
*
* This deadlock is avoided by perfomring async_synchronize_full()
* iff module init queued any async jobs. This isn't a full
* solution as it will deadlock the same if module loading from
* async jobs nests more than once; however, due to the various
* constraints, this hack seems to be the best option for now.
* Please refer to the following thread for details.
*
* http://thread.gmane.org/gmane.linux.kernel/1420814
*/
if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
module, async: async_synchronize_full() on module init iff async is used If the default iosched is built as module, the kernel may deadlock while trying to load the iosched module on device probe if the probing was running off async. This is because async_synchronize_full() at the end of module init ends up waiting for the async job which initiated the module loading. async A modprobe 1. finds a device 2. registers the block device 3. request_module(default iosched) 4. modprobe in userland 5. load and init module 6. async_synchronize_full() Async A waits for modprobe to finish in request_module() and modprobe waits for async A to finish in async_synchronize_full(). Because there's no easy to track dependency once control goes out to userland, implementing properly nested flushing is difficult. For now, make module init perform async_synchronize_full() iff module init has queued async jobs as suggested by Linus. This avoids the described deadlock because iosched module doesn't use async and thus wouldn't invoke async_synchronize_full(). This is hacky and incomplete. It will deadlock if async module loading nests; however, this works around the known problem case and seems to be the best of bad options. For more details, please refer to the following thread. http://thread.gmane.org/gmane.linux.kernel/1420814 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Alex Riesen <raa.lkml@gmail.com> Tested-by: Ming Lei <ming.lei@canonical.com> Tested-by: Alex Riesen <raa.lkml@gmail.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-16 10:52:51 +08:00
async_synchronize_full();
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
mutex_lock(&module_mutex);
/* Drop initial reference. */
module_put(mod);
trim_init_extable(mod);
#ifdef CONFIG_KALLSYMS
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
/* Switch to core kallsyms now init is done: kallsyms may be walking! */
rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
#endif
mod_tree_remove_init(mod);
disable_ro_nx(&mod->init_layout);
module_arch_freeing_init(mod);
mod->init_layout.base = NULL;
mod->init_layout.size = 0;
mod->init_layout.ro_size = 0;
mod->init_layout.text_size = 0;
/*
* We want to free module_init, but be aware that kallsyms may be
* walking this with preempt disabled. In all the failure paths, we
* call synchronize_sched(), but we don't want to slow down the success
* path, so use actual RCU here.
*/
call_rcu_sched(&freeinit->rcu, do_free_init);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
mutex_unlock(&module_mutex);
wake_up_all(&module_wq);
return 0;
fail_free_freeinit:
kfree(freeinit);
fail:
/* Try to protect us from buggy refcounters. */
mod->state = MODULE_STATE_GOING;
synchronize_sched();
module_put(mod);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
klp_module_going(mod);
ftrace_release_mod(mod);
free_module(mod);
wake_up_all(&module_wq);
return ret;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
}
static int may_init_module(void)
{
if (!capable(CAP_SYS_MODULE) || modules_disabled)
return -EPERM;
return 0;
}
/*
* We try to place it in the list now to make sure it's unique before
* we dedicate too many resources. In particular, temporary percpu
* memory exhaustion.
*/
static int add_unformed_module(struct module *mod)
{
int err;
struct module *old;
mod->state = MODULE_STATE_UNFORMED;
again:
mutex_lock(&module_mutex);
old = find_module_all(mod->name, strlen(mod->name), true);
if (old != NULL) {
if (old->state == MODULE_STATE_COMING
|| old->state == MODULE_STATE_UNFORMED) {
/* Wait in case it fails to load. */
mutex_unlock(&module_mutex);
err = wait_event_interruptible(module_wq,
finished_loading(mod->name));
if (err)
goto out_unlocked;
goto again;
}
err = -EEXIST;
goto out;
}
mod_update_bounds(mod);
list_add_rcu(&mod->list, &modules);
mod_tree_insert(mod);
err = 0;
out:
mutex_unlock(&module_mutex);
out_unlocked:
return err;
}
static int complete_formation(struct module *mod, struct load_info *info)
{
int err;
mutex_lock(&module_mutex);
/* Find duplicate symbols (must be called under lock). */
err = verify_export_symbols(mod);
if (err < 0)
goto out;
/* This relies on module_mutex for list integrity. */
module_bug_finalize(info->hdr, info->sechdrs, mod);
/* Set RO and NX regions */
module_enable_ro(mod);
module_enable_nx(mod);
/* Mark state as coming so strong_try_module_get() ignores us,
* but kallsyms etc. can see us. */
mod->state = MODULE_STATE_COMING;
mutex_unlock(&module_mutex);
return 0;
out:
mutex_unlock(&module_mutex);
return err;
}
static int prepare_coming_module(struct module *mod)
{
int err;
ftrace_module_enable(mod);
err = klp_module_coming(mod);
if (err)
return err;
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod);
return 0;
}
module: add extra argument for parse_params() callback This adds an extra argument onto parse_params() to be used as a way to make the unused callback a bit more useful and generic by allowing the caller to pass on a data structure of its choice. An example use case is to allow us to easily make module parameters for every module which we will do next. @ parse @ identifier name, args, params, num, level_min, level_max; identifier unknown, param, val, doing; type s16; @@ extern char *parse_args(const char *name, char *args, const struct kernel_param *params, unsigned num, s16 level_min, s16 level_max, + void *arg, int (*unknown)(char *param, char *val, const char *doing + , void *arg )); @ parse_mod @ identifier name, args, params, num, level_min, level_max; identifier unknown, param, val, doing; type s16; @@ char *parse_args(const char *name, char *args, const struct kernel_param *params, unsigned num, s16 level_min, s16 level_max, + void *arg, int (*unknown)(char *param, char *val, const char *doing + , void *arg )) { ... } @ parse_args_found @ expression R, E1, E2, E3, E4, E5, E6; identifier func; @@ ( R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, func); | R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, &func); | R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, NULL); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, func); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, &func); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, NULL); ) @ parse_args_unused depends on parse_args_found @ identifier parse_args_found.func; @@ int func(char *param, char *val, const char *unused + , void *arg ) { ... } @ mod_unused depends on parse_args_found @ identifier parse_args_found.func; expression A1, A2, A3; @@ - func(A1, A2, A3); + func(A1, A2, A3, NULL); Generated-by: Coccinelle SmPL Cc: cocci@systeme.lip6.fr Cc: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Hellwig <hch@infradead.org> Cc: Felipe Contreras <felipe.contreras@gmail.com> Cc: Ewan Milne <emilne@redhat.com> Cc: Jean Delvare <jdelvare@suse.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Jani Nikula <jani.nikula@intel.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-31 07:20:03 +08:00
static int unknown_module_param_cb(char *param, char *val, const char *modname,
void *arg)
{
struct module *mod = arg;
int ret;
if (strcmp(param, "async_probe") == 0) {
mod->async_probe_requested = true;
return 0;
}
/* Check for magic 'dyndbg' arg */
ret = ddebug_dyndbg_module_param_cb(param, val, modname);
if (ret != 0)
pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
return 0;
}
/* Allocate and load the module: note that size of section 0 is always
zero, and we rely on this for optional sections. */
static int load_module(struct load_info *info, const char __user *uargs,
int flags)
{
struct module *mod;
long err;
char *after_dashes;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = module_sig_check(info);
if (err)
goto free_copy;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = elf_header_check(info);
if (err)
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
goto free_copy;
/* Figure out module layout, and allocate all the memory. */
mod = layout_and_allocate(info, flags);
if (IS_ERR(mod)) {
err = PTR_ERR(mod);
goto free_copy;
}
/* Reserve our place in the list. */
err = add_unformed_module(mod);
if (err)
goto free_module;
#ifdef CONFIG_MODULE_SIG
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
mod->sig_ok = info->sig_ok;
if (!mod->sig_ok) {
pr_notice_once("%s: module verification failed: signature "
"and/or required key missing - tainting "
"kernel\n", mod->name);
Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE Users have reported being unable to trace non-signed modules loaded within a kernel supporting module signature. This is caused by tracepoint.c:tracepoint_module_coming() refusing to take into account tracepoints sitting within force-loaded modules (TAINT_FORCED_MODULE). The reason for this check, in the first place, is that a force-loaded module may have a struct module incompatible with the layout expected by the kernel, and can thus cause a kernel crash upon forced load of that module on a kernel with CONFIG_TRACEPOINTS=y. Tracepoints, however, specifically accept TAINT_OOT_MODULE and TAINT_CRAP, since those modules do not lead to the "very likely system crash" issue cited above for force-loaded modules. With kernels having CONFIG_MODULE_SIG=y (signed modules), a non-signed module is tainted re-using the TAINT_FORCED_MODULE taint flag. Unfortunately, this means that Tracepoints treat that module as a force-loaded module, and thus silently refuse to consider any tracepoint within this module. Since an unsigned module does not fit within the "very likely system crash" category of tainting, add a new TAINT_UNSIGNED_MODULE taint flag to specifically address this taint behavior, and accept those modules within Tracepoints. We use the letter 'X' as a taint flag character for a module being loaded that doesn't know how to sign its name (proposed by Steven Rostedt). Also add the missing 'O' entry to trace event show_module_flags() list for the sake of completeness. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> NAKed-by: Ingo Molnar <mingo@redhat.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: David Howells <dhowells@redhat.com> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-13 09:41:30 +08:00
add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
}
#endif
/* To avoid stressing percpu allocator, do this once we're unique. */
err = percpu_modalloc(mod, info);
if (err)
goto unlink_mod;
/* Now module is in final location, initialize linked lists, etc. */
err = module_unload_init(mod);
if (err)
goto unlink_mod;
init_param_lock(mod);
module: add per-module param_lock Add a "param_lock" mutex to each module, and update params.c to use the correct built-in or module mutex while locking kernel params. Remove the kparam_block_sysfs_r/w() macros, replace them with direct calls to kernel_param_[un]lock(module). The kernel param code currently uses a single mutex to protect modification of any and all kernel params. While this generally works, there is one specific problem with it; a module callback function cannot safely load another module, i.e. with request_module() or even with indirect calls such as crypto_has_alg(). If the module to be loaded has any of its params configured (e.g. with a /etc/modprobe.d/* config file), then the attempt will result in a deadlock between the first module param callback waiting for modprobe, and modprobe trying to lock the single kernel param mutex to set the new module's param. This fixes that by using per-module mutexes, so that each individual module is protected against concurrent changes in its own kernel params, but is not blocked by changes to other module params. All built-in modules continue to use the built-in mutex, since they will always be loaded at runtime and references (e.g. request_module(), crypto_has_alg()) to them will never cause load-time param changing. This also simplifies the interface used by modules to block sysfs access to their params; while there are currently functions to block and unblock sysfs param access which are split up by read and write and expect a single kernel param to be passed, their actual operation is identical and applies to all params, not just the one passed to them; they simply lock and unlock the global param mutex. They are replaced with direct calls to kernel_param_[un]lock(THIS_MODULE), which locks THIS_MODULE's param_lock, or if the module is built-in, it locks the built-in mutex. Suggested-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Dan Streetman <ddstreet@ieee.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-17 04:48:52 +08:00
/* Now we've got everything in the final locations, we can
* find optional sections. */
err = find_module_sections(mod, info);
if (err)
goto free_unload;
err = check_module_license_and_versions(mod);
if (err)
goto free_unload;
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
/* Set up MODINFO_ATTR fields */
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
setup_modinfo(mod, info);
[PATCH] modules: add version and srcversion to sysfs This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 13:05:15 +08:00
/* Fix up syms, so that st_value is a pointer to location. */
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = simplify_symbols(mod, info);
if (err < 0)
goto free_modinfo;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = apply_relocations(mod, info);
if (err < 0)
goto free_modinfo;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = post_relocation(mod, info);
if (err < 0)
goto free_modinfo;
flush_module_icache(mod);
/* Now copy in args */
mod->args = strndup_user(uargs, ~0UL >> 1);
if (IS_ERR(mod->args)) {
err = PTR_ERR(mod->args);
goto free_arch_cleanup;
}
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
dynamic_debug_setup(info->debug, info->num_debug);
ftrace/module: Hardcode ftrace_module_init() call into load_module() A race exists between module loading and enabling of function tracer. CPU 1 CPU 2 ----- ----- load_module() module->state = MODULE_STATE_COMING register_ftrace_function() mutex_lock(&ftrace_lock); ftrace_startup() update_ftrace_function(); ftrace_arch_code_modify_prepare() set_all_module_text_rw(); <enables-ftrace> ftrace_arch_code_modify_post_process() set_all_module_text_ro(); [ here all module text is set to RO, including the module that is loading!! ] blocking_notifier_call_chain(MODULE_STATE_COMING); ftrace_init_module() [ tries to modify code, but it's RO, and fails! ftrace_bug() is called] When this race happens, ftrace_bug() will produces a nasty warning and all of the function tracing features will be disabled until reboot. The simple solution is to treate module load the same way the core kernel is treated at boot. To hardcode the ftrace function modification of converting calls to mcount into nops. This is done in init/main.c there's no reason it could not be done in load_module(). This gives a better control of the changes and doesn't tie the state of the module to its notifiers as much. Ftrace is special, it needs to be treated as such. The reason this would work, is that the ftrace_module_init() would be called while the module is in MODULE_STATE_UNFORMED, which is ignored by the set_all_module_text_ro() call. Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.com Reported-by: Takao Indoh <indou.takao@jp.fujitsu.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@vger.kernel.org # 2.6.38+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-04-24 22:40:12 +08:00
/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
ftrace_module_init(mod);
/* Finally it's fully formed, ready to start executing. */
err = complete_formation(mod, info);
if (err)
goto ddebug_cleanup;
err = prepare_coming_module(mod);
if (err)
goto bug_cleanup;
/* Module is ready to execute: parsing args may do that. */
after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
-32768, 32767, mod,
module: add extra argument for parse_params() callback This adds an extra argument onto parse_params() to be used as a way to make the unused callback a bit more useful and generic by allowing the caller to pass on a data structure of its choice. An example use case is to allow us to easily make module parameters for every module which we will do next. @ parse @ identifier name, args, params, num, level_min, level_max; identifier unknown, param, val, doing; type s16; @@ extern char *parse_args(const char *name, char *args, const struct kernel_param *params, unsigned num, s16 level_min, s16 level_max, + void *arg, int (*unknown)(char *param, char *val, const char *doing + , void *arg )); @ parse_mod @ identifier name, args, params, num, level_min, level_max; identifier unknown, param, val, doing; type s16; @@ char *parse_args(const char *name, char *args, const struct kernel_param *params, unsigned num, s16 level_min, s16 level_max, + void *arg, int (*unknown)(char *param, char *val, const char *doing + , void *arg )) { ... } @ parse_args_found @ expression R, E1, E2, E3, E4, E5, E6; identifier func; @@ ( R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, func); | R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, &func); | R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, NULL); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, func); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, &func); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, NULL); ) @ parse_args_unused depends on parse_args_found @ identifier parse_args_found.func; @@ int func(char *param, char *val, const char *unused + , void *arg ) { ... } @ mod_unused depends on parse_args_found @ identifier parse_args_found.func; expression A1, A2, A3; @@ - func(A1, A2, A3); + func(A1, A2, A3, NULL); Generated-by: Coccinelle SmPL Cc: cocci@systeme.lip6.fr Cc: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Hellwig <hch@infradead.org> Cc: Felipe Contreras <felipe.contreras@gmail.com> Cc: Ewan Milne <emilne@redhat.com> Cc: Jean Delvare <jdelvare@suse.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Jani Nikula <jani.nikula@intel.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-31 07:20:03 +08:00
unknown_module_param_cb);
if (IS_ERR(after_dashes)) {
err = PTR_ERR(after_dashes);
goto coming_cleanup;
} else if (after_dashes) {
pr_warn("%s: parameters '%s' after `--' ignored\n",
mod->name, after_dashes);
}
/* Link in to syfs. */
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
if (err < 0)
goto coming_cleanup;
/* Get rid of temporary copy. */
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
free_copy(info);
/* Done! */
trace_module_load(mod);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
return do_init_module(mod);
coming_cleanup:
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
klp_module_going(mod);
bug_cleanup:
/* module_bug_cleanup needs module_mutex protection */
mutex_lock(&module_mutex);
2010-10-06 02:29:27 +08:00
module_bug_cleanup(mod);
mutex_unlock(&module_mutex);
/* we can't deallocate the module until we clear memory protection */
module_disable_ro(mod);
module_disable_nx(mod);
ddebug_cleanup:
dynamic_debug_remove(info->debug);
synchronize_sched();
kfree(mod->args);
free_arch_cleanup:
module_arch_cleanup(mod);
free_modinfo:
free_modinfo(mod);
free_unload:
module_unload_free(mod);
unlink_mod:
mutex_lock(&module_mutex);
/* Unlink carefully: kallsyms could be walking list. */
list_del_rcu(&mod->list);
mod_tree_remove(mod);
wake_up_all(&module_wq);
/* Wait for RCU-sched synchronizing before releasing mod->list. */
synchronize_sched();
mutex_unlock(&module_mutex);
free_module:
/*
* Ftrace needs to clean up what it initialized.
* This does nothing if ftrace_module_init() wasn't called,
* but it must be called outside of module_mutex.
*/
ftrace_release_mod(mod);
/* Free lock-classes; relies on the preceding sync_rcu() */
lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
module_deallocate(mod, info);
free_copy:
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
free_copy(info);
return err;
}
SYSCALL_DEFINE3(init_module, void __user *, umod,
unsigned long, len, const char __user *, uargs)
{
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
int err;
struct load_info info = { };
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = may_init_module();
if (err)
return err;
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
umod, len, uargs);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = copy_module_from_user(umod, len, &info);
if (err)
return err;
return load_module(&info, uargs, 0);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
}
module: Move RO/NX module protection to after ftrace module update The commit: 84e1c6bb38eb318e456558b610396d9f1afaabf0 x86: Add RO/NX protection for loadable kernel modules Broke the function tracer with this output: ------------[ cut here ]------------ WARNING: at kernel/trace/ftrace.c:1014 ftrace_bug+0x114/0x171() Hardware name: Precision WorkStation 470 Modules linked in: i2c_core(+) Pid: 86, comm: modprobe Not tainted 2.6.37-rc2+ #68 Call Trace: [<ffffffff8104e957>] warn_slowpath_common+0x85/0x9d [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffff8104e989>] warn_slowpath_null+0x1a/0x1c [<ffffffff810a9dfe>] ftrace_bug+0x114/0x171 [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffff810aa0db>] ftrace_process_locs+0x1ae/0x274 [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffff810aa29e>] ftrace_module_notify+0x39/0x44 [<ffffffff814405cf>] notifier_call_chain+0x37/0x63 [<ffffffff8106e054>] __blocking_notifier_call_chain+0x46/0x5b [<ffffffff8106e07d>] blocking_notifier_call_chain+0x14/0x16 [<ffffffff8107ffde>] sys_init_module+0x73/0x1f3 [<ffffffff8100acf2>] system_call_fastpath+0x16/0x1b ---[ end trace 2aff4f4ca53ec746 ]--- ftrace faulted on writing [<ffffffffa00026db>] __process_new_adapter+0x7/0x34 [i2c_core] The cause was that the module text was set to read only before ftrace could convert the calls to mcount to nops. Thus, the conversions failed due to not being able to write to the text locations. The simple fix is to move setting the module to read only after the module notifiers are called (where ftrace sets the module mcounts to nops). Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-30 02:15:42 +08:00
SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
{
struct load_info info = { };
loff_t size;
void *hdr;
int err;
module: Move RO/NX module protection to after ftrace module update The commit: 84e1c6bb38eb318e456558b610396d9f1afaabf0 x86: Add RO/NX protection for loadable kernel modules Broke the function tracer with this output: ------------[ cut here ]------------ WARNING: at kernel/trace/ftrace.c:1014 ftrace_bug+0x114/0x171() Hardware name: Precision WorkStation 470 Modules linked in: i2c_core(+) Pid: 86, comm: modprobe Not tainted 2.6.37-rc2+ #68 Call Trace: [<ffffffff8104e957>] warn_slowpath_common+0x85/0x9d [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffff8104e989>] warn_slowpath_null+0x1a/0x1c [<ffffffff810a9dfe>] ftrace_bug+0x114/0x171 [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffff810aa0db>] ftrace_process_locs+0x1ae/0x274 [<ffffffffa00026db>] ? __process_new_adapter+0x7/0x34 [i2c_core] [<ffffffff810aa29e>] ftrace_module_notify+0x39/0x44 [<ffffffff814405cf>] notifier_call_chain+0x37/0x63 [<ffffffff8106e054>] __blocking_notifier_call_chain+0x46/0x5b [<ffffffff8106e07d>] blocking_notifier_call_chain+0x14/0x16 [<ffffffff8107ffde>] sys_init_module+0x73/0x1f3 [<ffffffff8100acf2>] system_call_fastpath+0x16/0x1b ---[ end trace 2aff4f4ca53ec746 ]--- ftrace faulted on writing [<ffffffffa00026db>] __process_new_adapter+0x7/0x34 [i2c_core] The cause was that the module text was set to read only before ftrace could convert the calls to mcount to nops. Thus, the conversions failed due to not being able to write to the text locations. The simple fix is to move setting the module to read only after the module notifiers are called (where ftrace sets the module mcounts to nops). Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-30 02:15:42 +08:00
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
err = may_init_module();
if (err)
return err;
pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
|MODULE_INIT_IGNORE_VERMAGIC))
return -EINVAL;
async: Fix module loading async-work regression Several drivers use asynchronous work to do device discovery, and we synchronize with them in the compiled-in case before we actually try to mount root filesystems etc. However, when compiled as modules, that synchronization is missing - the module loading completes, but the driver hasn't actually finished probing for devices, and that means that any user mode that expects to use the devices after the 'insmod' is now potentially broken. We already saw one case of a similar issue in the ACPI battery code, where the kernel itself expected the module to be all done, and unmapped the init memory - but the async device discovery was still running. That got hacked around by just removing the "__init" (see commit 5d38258ec026921a7b266f4047ebeaa75db358e5 "ACPI battery: fix async boot oops"), but the real fix is to just make the module loading wait for all async work to be completed. It will slow down module loading, but since common devices should be built in anyway, and since the bug is really annoying and hard to handle from user space (and caused several S3 resume regressions), the simple fix to wait is the right one. This fixes at least http://bugzilla.kernel.org/show_bug.cgi?id=13063 but probably a few other bugzilla entries too (12936, for example), and is confirmed to fix Rafael's storage driver breakage after resume bug report (no bugzilla entry). We should also be able to now revert that ACPI battery fix. Reported-and-tested-by: Rafael J. Wysocki <rjw@suse.com> Tested-by: Heinz Diehl <htd@fancy-poultry.org> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-11 03:17:41 +08:00
err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
READING_MODULE);
module: add syscall to load module from fd As part of the effort to create a stronger boundary between root and kernel, Chrome OS wants to be able to enforce that kernel modules are being loaded only from our read-only crypto-hash verified (dm_verity) root filesystem. Since the init_module syscall hands the kernel a module as a memory blob, no reasoning about the origin of the blob can be made. Earlier proposals for appending signatures to kernel modules would not be useful in Chrome OS, since it would involve adding an additional set of keys to our kernel and builds for no good reason: we already trust the contents of our root filesystem. We don't need to verify those kernel modules a second time. Having to do signature checking on module loading would slow us down and be redundant. All we need to know is where a module is coming from so we can say yes/no to loading it. If a file descriptor is used as the source of a kernel module, many more things can be reasoned about. In Chrome OS's case, we could enforce that the module lives on the filesystem we expect it to live on. In the case of IMA (or other LSMs), it would be possible, for example, to examine extended attributes that may contain signatures over the contents of the module. This introduces a new syscall (on x86), similar to init_module, that has only two arguments. The first argument is used as a file descriptor to the module and the second argument is a pointer to the NULL terminated string of module arguments. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (merge fixes)
2012-10-16 05:01:07 +08:00
if (err)
return err;
info.hdr = hdr;
info.len = size;
return load_module(&info, uargs, flags);
}
static inline int within(unsigned long addr, void *start, unsigned long size)
{
return ((void *)addr >= start && (void *)addr < start + size);
}
#ifdef CONFIG_KALLSYMS
/*
* This ignores the intensely annoying "mapping symbols" found
* in ARM ELF files: $a, $t and $d.
*/
static inline int is_arm_mapping_symbol(const char *str)
{
if (str[0] == '.' && str[1] == 'L')
return true;
return str[0] == '$' && strchr("axtd", str[1])
&& (str[2] == '\0' || str[2] == '.');
}
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
{
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
}
static const char *get_ksymbol(struct module *mod,
unsigned long addr,
unsigned long *size,
unsigned long *offset)
{
unsigned int i, best = 0;
unsigned long nextval;
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
/* At worse, next value is at end of module */
module: add within_module_core() and within_module_init() This series of patches allows kprobes to probe module's __init and __exit functions. This means, you can probe driver initialization and terminating. Currently, kprobes can't probe __init function because these functions are freed after module initialization. And it also can't probe module __exit functions because kprobe increments reference count of target module and user can't unload it. this means __exit functions never be called unless removing probes from the module. To solve both cases, this series of patches introduces GONE flag and sets it when the target code is freed(for this purpose, kprobes hooks MODULE_STATE_* events). This also removes refcount incrementing for allowing user to unload target module. Users can check which probes are GONE by debugfs interface. For taking timing of freeing module's .init text, these also include a patch which adds module's notifier of MODULE_STATE_LIVE event. This patch: Add within_module_core() and within_module_init() for checking whether an address is in the module .init.text section or .text section, and replace within() local inline functions in kernel/module.c with them. kprobes uses these functions to check where the kprobe is inserted. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-07 06:41:49 +08:00
if (within_module_init(addr, mod))
nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
else
nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
/* Scan for closest preceding symbol, and next symbol. (ELF
starts real symbols at 1). */
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
for (i = 1; i < kallsyms->num_symtab; i++) {
if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
continue;
/* We ignore unnamed symbols: they're uninformative
* and inserted at a whim. */
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
if (*symname(kallsyms, i) == '\0'
|| is_arm_mapping_symbol(symname(kallsyms, i)))
continue;
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
if (kallsyms->symtab[i].st_value <= addr
&& kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
best = i;
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
if (kallsyms->symtab[i].st_value > addr
&& kallsyms->symtab[i].st_value < nextval)
nextval = kallsyms->symtab[i].st_value;
}
if (!best)
return NULL;
if (size)
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
*size = nextval - kallsyms->symtab[best].st_value;
if (offset)
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
*offset = addr - kallsyms->symtab[best].st_value;
return symname(kallsyms, best);
}
/* For kallsyms to ask for address resolution. NULL means not found. Careful
* not to lock to avoid deadlock on oopses, simply disable preemption. */
const char *module_address_lookup(unsigned long addr,
unsigned long *size,
unsigned long *offset,
char **modname,
char *namebuf)
{
const char *ret = NULL;
struct module *mod;
preempt_disable();
mod = __module_address(addr);
if (mod) {
if (modname)
*modname = mod->name;
ret = get_ksymbol(mod, addr, size, offset);
}
/* Make a copy in here where it's safe */
if (ret) {
strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
ret = namebuf;
}
preempt_enable();
return ret;
}
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
struct module *mod;
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
if (within_module(addr, mod)) {
const char *sym;
sym = get_ksymbol(mod, addr, NULL, NULL);
if (!sym)
goto out;
strlcpy(symname, sym, KSYM_NAME_LEN);
preempt_enable();
return 0;
}
}
out:
preempt_enable();
return -ERANGE;
}
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
unsigned long *offset, char *modname, char *name)
{
struct module *mod;
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
if (within_module(addr, mod)) {
const char *sym;
sym = get_ksymbol(mod, addr, size, offset);
if (!sym)
goto out;
if (modname)
strlcpy(modname, mod->name, MODULE_NAME_LEN);
if (name)
strlcpy(name, sym, KSYM_NAME_LEN);
preempt_enable();
return 0;
}
}
out:
preempt_enable();
return -ERANGE;
}
int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
char *name, char *module_name, int *exported)
{
struct module *mod;
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
struct mod_kallsyms *kallsyms;
if (mod->state == MODULE_STATE_UNFORMED)
continue;
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
kallsyms = rcu_dereference_sched(mod->kallsyms);
if (symnum < kallsyms->num_symtab) {
*value = kallsyms->symtab[symnum].st_value;
*type = kallsyms->symtab[symnum].st_info;
strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
*exported = is_exported(name, *value, mod);
preempt_enable();
return 0;
}
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
symnum -= kallsyms->num_symtab;
}
preempt_enable();
return -ERANGE;
}
static unsigned long mod_find_symname(struct module *mod, const char *name)
{
unsigned int i;
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
for (i = 0; i < kallsyms->num_symtab; i++)
if (strcmp(name, symname(kallsyms, i)) == 0 &&
kallsyms->symtab[i].st_info != 'U')
return kallsyms->symtab[i].st_value;
return 0;
}
/* Look for this name: can be of form module:name. */
unsigned long module_kallsyms_lookup_name(const char *name)
{
struct module *mod;
char *colon;
unsigned long ret = 0;
/* Don't lock: we're in enough trouble already. */
preempt_disable();
if ((colon = strchr(name, ':')) != NULL) {
if ((mod = find_module_all(name, colon - name, false)) != NULL)
ret = mod_find_symname(mod, colon+1);
} else {
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
if ((ret = mod_find_symname(mod, name)) != 0)
break;
}
}
preempt_enable();
return ret;
}
int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
struct module *, unsigned long),
void *data)
{
struct module *mod;
unsigned int i;
int ret;
module_assert_mutex();
list_for_each_entry(mod, &modules, list) {
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
/* We hold module_mutex: no need for rcu_dereference_sched */
struct mod_kallsyms *kallsyms = mod->kallsyms;
if (mod->state == MODULE_STATE_UNFORMED)
continue;
modules: fix longstanding /proc/kallsyms vs module insertion race. For CONFIG_KALLSYMS, we keep two symbol tables and two string tables. There's one full copy, marked SHF_ALLOC and laid out at the end of the module's init section. There's also a cut-down version that only contains core symbols and strings, and lives in the module's core section. After module init (and before we free the module memory), we switch the mod->symtab, mod->num_symtab and mod->strtab to point to the core versions. We do this under the module_mutex. However, kallsyms doesn't take the module_mutex: it uses preempt_disable() and rcu tricks to walk through the modules, because it's used in the oops path. It's also used in /proc/kallsyms. There's nothing atomic about the change of these variables, so we can get the old (larger!) num_symtab and the new symtab pointer; in fact this is what I saw when trying to reproduce. By grouping these variables together, we can use a carefully-dereferenced pointer to ensure we always get one or the other (the free of the module init section is already done in an RCU callback, so that's safe). We allocate the init one at the end of the module init section, and keep the core one inside the struct module itself (it could also have been allocated at the end of the module core, but that's probably overkill). Reported-by: Weilong Chen <chenweilong@huawei.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541 Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-02-03 14:25:26 +08:00
for (i = 0; i < kallsyms->num_symtab; i++) {
ret = fn(data, symname(kallsyms, i),
mod, kallsyms->symtab[i].st_value);
if (ret != 0)
return ret;
}
}
return 0;
}
#endif /* CONFIG_KALLSYMS */
static char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
BUG_ON(mod->state == MODULE_STATE_UNFORMED);
if (mod->taints ||
mod->state == MODULE_STATE_GOING ||
mod->state == MODULE_STATE_COMING) {
buf[bx++] = '(';
bx += module_flags_taint(mod, buf + bx);
/* Show a - for module-is-being-unloaded */
if (mod->state == MODULE_STATE_GOING)
buf[bx++] = '-';
/* Show a + for module-is-being-loaded */
if (mod->state == MODULE_STATE_COMING)
buf[bx++] = '+';
buf[bx++] = ')';
}
buf[bx] = '\0';
return buf;
}
#ifdef CONFIG_PROC_FS
/* Called by the /proc file system to return a list of modules. */
static void *m_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&module_mutex);
return seq_list_start(&modules, *pos);
}
static void *m_next(struct seq_file *m, void *p, loff_t *pos)
{
return seq_list_next(p, &modules, pos);
}
static void m_stop(struct seq_file *m, void *p)
{
mutex_unlock(&module_mutex);
}
static int m_show(struct seq_file *m, void *p)
{
struct module *mod = list_entry(p, struct module, list);
char buf[8];
/* We always ignore unformed modules. */
if (mod->state == MODULE_STATE_UNFORMED)
return 0;
seq_printf(m, "%s %u",
mod->name, mod->init_layout.size + mod->core_layout.size);
print_unload_info(m, mod);
/* Informative for users. */
seq_printf(m, " %s",
mod->state == MODULE_STATE_GOING ? "Unloading" :
mod->state == MODULE_STATE_COMING ? "Loading" :
"Live");
/* Used by oprofile and other similar tools. */
seq_printf(m, " 0x%pK", mod->core_layout.base);
/* Taints info */
if (mod->taints)
seq_printf(m, " %s", module_flags(mod, buf));
seq_puts(m, "\n");
return 0;
}
/* Format: modulename size refcount deps address
Where refcount is a number or -, and deps is a comma-separated list
of depends or -.
*/
static const struct seq_operations modules_op = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = m_show
};
static int modules_open(struct inode *inode, struct file *file)
{
return seq_open(file, &modules_op);
}
static const struct file_operations proc_modules_operations = {
.open = modules_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init proc_modules_init(void)
{
proc_create("modules", 0, NULL, &proc_modules_operations);
return 0;
}
module_init(proc_modules_init);
#endif
/* Given an address, look for it in the module exception tables. */
const struct exception_table_entry *search_module_extables(unsigned long addr)
{
const struct exception_table_entry *e = NULL;
struct module *mod;
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
if (mod->num_exentries == 0)
continue;
e = search_extable(mod->extable,
mod->extable + mod->num_exentries - 1,
addr);
if (e)
break;
}
preempt_enable();
/* Now, if we found one, we are running inside it now, hence
we cannot unload the module, hence no refcnt needed. */
return e;
}
/*
* is_module_address - is this address inside a module?
* @addr: the address to check.
*
* See is_module_text_address() if you simply want to see if the address
* is code (not data).
*/
bool is_module_address(unsigned long addr)
{
bool ret;
preempt_disable();
ret = __module_address(addr) != NULL;
preempt_enable();
return ret;
}
/*
* __module_address - get the module which contains an address.
* @addr: the address.
*
* Must be called with preempt disabled or module mutex held so that
* module doesn't get freed during this.
*/
struct module *__module_address(unsigned long addr)
{
struct module *mod;
if (addr < module_addr_min || addr > module_addr_max)
return NULL;
module_assert_mutex_or_preempt();
mod = mod_find(addr);
if (mod) {
BUG_ON(!within_module(addr, mod));
if (mod->state == MODULE_STATE_UNFORMED)
mod = NULL;
}
return mod;
}
EXPORT_SYMBOL_GPL(__module_address);
/*
* is_module_text_address - is this address inside module code?
* @addr: the address to check.
*
* See is_module_address() if you simply want to see if the address is
* anywhere in a module. See kernel_text_address() for testing if an
* address corresponds to kernel or module code.
*/
bool is_module_text_address(unsigned long addr)
{
bool ret;
preempt_disable();
ret = __module_text_address(addr) != NULL;
preempt_enable();
return ret;
}
/*
* __module_text_address - get the module whose code contains an address.
* @addr: the address.
*
* Must be called with preempt disabled or module mutex held so that
* module doesn't get freed during this.
*/
struct module *__module_text_address(unsigned long addr)
{
struct module *mod = __module_address(addr);
if (mod) {
/* Make sure it's within the text section. */
if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
&& !within(addr, mod->core_layout.base, mod->core_layout.text_size))
mod = NULL;
}
return mod;
}
EXPORT_SYMBOL_GPL(__module_text_address);
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
struct module *mod;
char buf[8];
printk(KERN_DEFAULT "Modules linked in:");
/* Most callers should already have preempt disabled, but make sure */
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
pr_cont(" %s%s", mod->name, module_flags(mod, buf));
}
preempt_enable();
if (last_unloaded_module[0])
pr_cont(" [last unloaded: %s]", last_unloaded_module);
pr_cont("\n");
}
#ifdef CONFIG_MODVERSIONS
/* Generate the signature for all relevant module structures here.
* If these change, we don't want to try to parse the module. */
void module_layout(struct module *mod,
struct modversion_info *ver,
struct kernel_param *kp,
struct kernel_symbol *ks,
tracepoints: Fix section alignment using pointer array Make the tracepoints more robust, making them solid enough to handle compiler changes by not relying on anything based on compiler-specific behavior with respect to structure alignment. Implement an approach proposed by David Miller: use an array of const pointers to refer to the individual structures, and export this pointer array through the linker script rather than the structures per se. It will consume 32 extra bytes per tracepoint (24 for structure padding and 8 for the pointers), but are less likely to break due to compiler changes. History: commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE() added the aligned(32) type and variable attribute to the tracepoint structures to deal with gcc happily aligning statically defined structures on 32-byte multiples. One attempt was to use a 8-byte alignment for tracepoint structures by applying both the variable and type attribute to tracepoint structures definitions and declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5. The reason is that the "aligned" attribute only specify the _minimum_ alignment for a structure, leaving both the compiler and the linker free to align on larger multiples. Because tracepoint.c expects the structures to be placed as an array within each section, up-alignment cause NULL-pointer exceptions due to the extra unexpected padding. (this patch applies on top of -tip) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: David S. Miller <davem@davemloft.net> LKML-Reference: <20110126222622.GA10794@Krystal> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Thomas Gleixner <tglx@linutronix.de> CC: Andrew Morton <akpm@linux-foundation.org> CC: Peter Zijlstra <peterz@infradead.org> CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-01-27 06:26:22 +08:00
struct tracepoint * const *tp)
{
}
EXPORT_SYMBOL(module_layout);
#endif