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>
Prarit's excellent bug report:
> In recent Fedora releases (F17 & F18) some users have reported seeing
> messages similar to
>
> [ 15.478160] kvm: Could not allocate 304 bytes percpu data
> [ 15.478174] PERCPU: allocation failed, size=304 align=32, alloc from
> reserved chunk failed
>
> during system boot. In some cases, users have also reported seeing this
> message along with a failed load of other modules.
>
> What is happening is systemd is loading an instance of the kvm module for
> each cpu found (see commit e9bda3b). When the module load occurs the kernel
> currently allocates the modules percpu data area prior to checking to see
> if the module is already loaded or is in the process of being loaded. If
> the module is already loaded, or finishes load, the module loading code
> releases the current instance's module's percpu data.
Now we have a new state MODULE_STATE_UNFORMED, we can insert the
module into the list (and thus guarantee its uniqueness) before we
allocate the per-cpu region.
Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Prarit Bhargava <prarit@redhat.com>
You should never look at such a module, so it's excised from all paths
which traverse the modules list.
We add the state at the end, to avoid gratuitous ABI break (ksplice).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If we try to finit_module on a file sized 0 bytes vmalloc will
scream and spit out a warning.
Since modules have to be bigger than 0 bytes anyways we can just
check that beforehand and avoid the warning.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
to verify the source of the module (ChromeOS) and/or use standard IMA on it
or other security hooks.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module update from Rusty Russell:
"Nothing all that exciting; a new module-from-fd syscall for those who
want to verify the source of the module (ChromeOS) and/or use standard
IMA on it or other security hooks."
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
MODSIGN: Fix kbuild output when using default extra_certificates
MODSIGN: Avoid using .incbin in C source
modules: don't hand 0 to vmalloc.
module: Remove a extra null character at the top of module->strtab.
ASN.1: Use the ASN1_LONG_TAG and ASN1_INDEFINITE_LENGTH constants
ASN.1: Define indefinite length marker constant
moduleparam: use __UNIQUE_ID()
__UNIQUE_ID()
MODSIGN: Add modules_sign make target
powerpc: add finit_module syscall.
ima: support new kernel module syscall
add finit_module syscall to asm-generic
ARM: add finit_module syscall to ARM
security: introduce kernel_module_from_file hook
module: add flags arg to sys_finit_module()
module: add syscall to load module from fd
In commit 9c0ece069b ("Get rid of Documentation/feature-removal.txt"),
Linus removed feature-removal-schedule.txt from Documentation, but there
is still some reference to this file. So remove them.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit d0a21265df David Rientjes unified various archs'
module_alloc implementation (including x86) and removed the graduitous
shortcut for size == 0.
Then, in commit de7d2b567d, Joe Perches added a warning for
zero-length vmallocs, which can happen without kallsyms on modules
with no init sections (eg. zlib_deflate).
Fix this once and for all; the module code has to handle zero length
anyway, so get it right at the caller and remove the now-gratuitous
checks within the arch-specific module_alloc implementations.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42608
Reported-by: Conrad Kostecki <ConiKost@gmx.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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>
Now that kernel module origins can be reasoned about, provide a hook to
the LSMs to make policy decisions about the module file. This will let
Chrome OS enforce that loadable kernel modules can only come from its
read-only hash-verified root filesystem. Other LSMs can, for example,
read extended attributes for signatures, etc.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Thanks to Michael Kerrisk for keeping us honest. These flags are actually
useful for eliminating the only case where kmod has to mangle a module's
internals: for overriding module versioning.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Acked-by: Kees Cook <keescook@chromium.org>
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)
Masaki found and patched a kallsyms issue: the last symbol in a
module's symtab wasn't transferred. This is because we manually copy
the zero'th entry (which is always empty) then copy the rest in a loop
starting at 1, though from src[0]. His fix was minimal, I prefer to
rewrite the loops in more standard form.
There are two loops: one to get the size, and one to copy. Make these
identical: always count entry 0 and any defined symbol in an allocated
non-init section.
This bug exists since the following commit was introduced.
module: reduce symbol table for loaded modules (v2)
commit: 4a4962263f
LKML: http://lkml.org/lkml/2012/10/24/27
Reported-by: Masaki Kimura <masaki.kimura.kz@hitachi.com>
Cc: stable@kernel.org
Emit the magic string that indicates a module has a signature after the
signature data instead of before it. This allows module_sig_check() to
be made simpler and faster by the elimination of the search for the
magic string. Instead we just need to do a single memcmp().
This works because at the end of the signature data there is the
fixed-length signature information block. This block then falls
immediately prior to the magic number.
From the contents of the information block, it is trivial to calculate
the size of the signature data and thus the size of the actual module
data.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we're in FIPS mode, we should panic if we fail to verify the signature on a
module or we're asked to load an unsigned module in signature enforcing mode.
Possibly FIPS mode should automatically enable enforcing mode.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We do a very simple search for a particular string appended to the module
(which is cache-hot and about to be SHA'd anyway). There's both a config
option and a boot parameter which control whether we accept or fail with
unsigned modules and modules that are signed with an unknown key.
If module signing is enabled, the kernel will be tainted if a module is
loaded that is unsigned or has a signature for which we don't have the
key.
(Useful feedback and tweaks by David Howells <dhowells@redhat.com>)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The original module-init-tools module loader used a fnctl lock on the
.ko file to avoid attempts to simultaneously load a module.
Unfortunately, you can't get an exclusive fcntl lock on a read-only
fd, making this not work for read-only mounted filesystems.
module-init-tools has a hacky sleep-and-loop for this now.
It's not that hard to wait in the kernel, and only return -EEXIST once
the first module has finished loading (or continue loading the module
if the first one failed to initialize for some reason). It's also
consistent with what we do for dependent modules which are still loading.
Suggested-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We use resolve_symbol_wait(), which blocks if the module containing
the symbol is still loading. However:
1) The module_wq we use is only woken after calling the modules' init
function, but there are other failure paths after the module is
placed in the linked list where we need to do the same thing.
2) wake_up() only wakes one waiter, and our waitqueue is shared by all
modules, so we need to wake them all.
3) wake_up_all() doesn't imply a memory barrier: I feel happier calling
it after we've grabbed and dropped the module_mutex, not just after
the state assignment.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Use the mapping of Elf_[SPE]hdr, Elf_Addr, Elf_Sym, Elf_Dyn, Elf_Rel/Rela,
ELF_R_TYPE() and ELF_R_SYM() to either the 32-bit version or the 64-bit version
into asm-generic/module.h for all arches bar MIPS.
Also, use the generic definition mod_arch_specific where possible.
To this end, I've defined three new config bools:
(*) HAVE_MOD_ARCH_SPECIFIC
Arches define this if they don't want to use the empty generic
mod_arch_specific struct.
(*) MODULES_USE_ELF_RELA
Arches define this if their modules can contain RELA records. This causes
the Elf_Rela mapping to be emitted and allows apply_relocate_add() to be
defined by the arch rather than have the core emit an error message.
(*) MODULES_USE_ELF_REL
Arches define this if their modules can contain REL records. This causes
the Elf_Rel mapping to be emitted and allows apply_relocate() to be
defined by the arch rather than have the core emit an error message.
Note that it is possible to allow both REL and RELA records: m68k and mips are
two arches that do this.
With this, some arch asm/module.h files can be deleted entirely and replaced
with a generic-y marker in the arch Kbuild file.
Additionally, I have removed the bits from m32r and score that handle the
unsupported type of relocation record as that's now handled centrally.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cloudlinux have a product called lve that includes a kernel module. This
was previously GPLed but is now under a proprietary license, but the
module continues to declare MODULE_LICENSE("GPL") and makes use of some
EXPORT_SYMBOL_GPL symbols. Forcibly taint it in order to avoid this.
Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Alex Lyashkov <umka@cloudlinux.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
The check:
if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
may not work if there's an overflow in the right-hand side of the condition.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This introduces a fake module param $module.dyndbg. Its based upon
Thomas Renninger's $module.ddebug boot-time debugging patch from
https://lkml.org/lkml/2010/9/15/397
The 'fake' module parameter is provided for all modules, whether or
not they need it. It is not explicitly added to each module, but is
implemented in callbacks invoked from parse_args.
For builtin modules, dynamic_debug_init() now directly calls
parse_args(..., &ddebug_dyndbg_boot_params_cb), to process the params
undeclared in the modules, just after the ddebug tables are processed.
While its slightly weird to reprocess the boot params, parse_args() is
already called repeatedly by do_initcall_levels(). More importantly,
the dyndbg queries (given in ddebug_query or dyndbg params) cannot be
activated until after the ddebug tables are ready, and reusing
parse_args is cleaner than doing an ad-hoc parse. This reparse would
break options like inc_verbosity, but they probably should be params,
like verbosity=3.
ddebug_dyndbg_boot_params_cb() handles both bare dyndbg (aka:
ddebug_query) and module-prefixed dyndbg params, and ignores all other
parameters. For example, the following will enable pr_debug()s in 4
builtin modules, in the order given:
dyndbg="module params +p; module aio +p" module.dyndbg=+p pci.dyndbg
For loadable modules, parse_args() in load_module() calls
ddebug_dyndbg_module_params_cb(). This handles bare dyndbg params as
passed from modprobe, and errors on other unknown params.
Note that modprobe reads /proc/cmdline, so "modprobe foo" grabs all
foo.params, strips the "foo.", and passes these to the kernel.
ddebug_dyndbg_module_params_cb() is again called for the unknown
params; it handles dyndbg, and errors on others. The "doing" arg
added previously contains the module name.
For non CONFIG_DYNAMIC_DEBUG builds, the stub function accepts
and ignores $module.dyndbg params, other unknowns get -ENOENT.
If no param value is given (as in pci.dyndbg example above), "+p" is
assumed, which enables all pr_debug callsites in the module.
The dyndbg fake parameter is not shown in /sys/module/*/parameters,
thus it does not use any resources. Changes to it are made via the
control file.
Also change pr_info in ddebug_exec_queries to vpr_info,
no need to see it all the time.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
CC: Thomas Renninger <trenn@suse.de>
CC: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Module size was limited to 64MB, this was legacy limitation due to vmalloc()
which was removed a while ago.
Limiting module size to 64MB is both pointless and affects real world use
cases.
Cc: Tim Abbott <tim.abbott@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This patch adds a set of macros that can be used to declare
kernel parameters to be parsed _before_ initcalls at a chosen
level are executed. We rename the now-unused "flags" field of
struct kernel_param as the level. It's signed, for when we
use this for early params as well, in future.
Linker macro collating init calls had to be modified in order
to add additional symbols between levels that are later used
by the init code to split the calls into blocks.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Sometimes we need to test a kernel of same version with code or config
option changes.
We already have sysctl to disable module load, but add a kernel
parameter will be more convenient.
Since modules_disabled is int, so here use bint type in core_param.
TODO: make sysctl accept bool and change modules_disabled to bool
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Recent changes to kernel/module.c caused the following compile
error:
kernel/module.c: In function ‘show_taint’:
kernel/module.c:1024:2: error: implicit declaration of function ‘module_flags_taint’ [-Werror=implicit-function-declaration]
cc1: some warnings being treated as errors
Correct this error by moving the definition of module_flags_taint
outside of the #ifdef CONFIG_MODULE_UNLOAD section.
Signed-off-by: Kevin Winchester <kjwinchester@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recent tools do not want to use /proc to retrieve module information. A few
values are currently missing from sysfs to replace the information available
in /proc/modules.
This adds /sys/module/*/{coresize,initsize,taint} attributes.
TAINT_PROPRIETARY_MODULE (P) and TAINT_OOT_MODULE (O) flags are both always
shown now, and do no longer exclude each other, also in /proc/modules.
Replace the open-coded sysfs attribute initializers with the __ATTR() macro.
Add the new attributes to Documentation/ABI.
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Use more flexible pr_debug. This allows:
echo "module module +p" > /dbg/dynamic_debug/control
to turn on debug messages when needed.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
module_ref contains two "unsigned int" fields.
Thats now too small, since some machines can open more than 2^32 files.
Check commit 518de9b39e (fs: allow for more than 2^31 files) for
reference.
We can add an aligned(2 * sizeof(unsigned long)) attribute to force
alloc_percpu() allocating module_ref areas in single cache lines.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Tejun Heo <tj@kernel.org>
CC: Robin Holt <holt@sgi.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Looking at /proc/kallsyms, one starts to ponder whether all of the extra
strtab-related complexity in module.c is worth the memory savings.
Instead of making the add_kallsyms() loop even more complex, I tried the
other route of deleting the strmap logic and naively copying each string
into core_strtab with no consideration for consolidating duplicates.
Performance on an "already exists" insmod of nvidia.ko (runs
add_kallsyms() but does not actually initialize the module):
Original scheme: 1.230s
With naive copying: 0.058s
Extra space used: 35k (of a 408k module).
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <73defb5e4bca04a6431392cc341112b1@localhost>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
Use of the GPL or a compatible licence doesn't necessarily make the code
any good. We already consider staging modules to be suspect, and this
should also be true for out-of-tree modules which may receive very
little review.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reviewed-by: Dave Jones <davej@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (patched oops-tracing.txt)
Dynamic debugging is currently disabled for tainted modules, except
for TAINT_CRAP. This prevents use of dynamic debugging for
out-of-tree modules once the next patch is applied.
This condition was apparently intended to avoid a crash if a force-
loaded module has an incompatible definition of dynamic debug
structures. However, a administrator that forces us to load a module
is claiming that it *is* compatible even though it fails our version
checks. If they are mistaken, there are any number of ways the module
could crash the system.
As a side-effect, proprietary and other tainted modules can now use
dynamic_debug.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else. Revector them
onto the isolated export header for faster compile times.
Nothing to see here but a whole lot of instances of:
-#include <linux/module.h>
+#include <linux/export.h>
This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Copy the information needed from struct module into a local module list
held within tracepoint.c from within the module coming/going notifier.
This vastly simplifies locking of tracepoint registration /
unregistration, because we don't have to take the module mutex to
register and unregister tracepoints anymore. Steven Rostedt ran into
dependency problems related to modules mutex vs kprobes mutex vs ftrace
mutex vs tracepoint mutex that seems to be hard to fix without removing
this dependency between tracepoint and module mutex. (note: it should be
investigated whether kprobes could benefit of being dissociated from the
modules mutex too.)
This also fixes module handling of tracepoint list iterators, because it
was expecting the list to be sorted by pointer address. Given we have
control on our own list now, it's OK to sort this list which has
tracepoints as its only purpose. The reason why this sorting is required
is to handle the fact that seq files (and any read() operation from
user-space) cannot hold the tracepoint mutex across multiple calls, so
list entries may vanish between calls. With sorting, the tracepoint
iterator becomes usable even if the list don't contain the exact item
pointed to by the iterator anymore.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Jason Baron <jbaron@redhat.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20110810191839.GC8525@Krystal
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Userspace wants to manage module parameters with udev rules.
This currently only works for loaded modules, but not for
built-in ones.
To allow access to the built-in modules we need to
re-trigger all module load events that happened before any
userspace was running. We already do the same thing for all
devices, subsystems(buses) and drivers.
This adds the currently missing /sys/module/<name>/uevent files
to all module entries.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split & trivial fix)
This simplifies the next patch, where we have an attribute on a
builtin module (ie. module == NULL).
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split into 2)
The module loader code allows architectures to hook into the code by
providing a small number of entry points that each arch must implement.
This patch provides __weakly linked generic implementations of these
entry points for architectures that don't need to do anything special.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'staging-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (970 commits)
staging: usbip: replace usbip_u{dbg,err,info} and printk with dev_ and pr_
staging:iio: Trivial kconfig reorganization and uniformity improvements.
staging:iio:documenation partial update.
staging:iio: use pollfunc allocation helpers in remaining drivers.
staging:iio:max1363 misc cleanups and use of for_each_bit_set to simplify event code spitting out.
staging:iio: implement an iio_info structure to take some of the constant elements out of iio_dev.
staging:iio:meter:ade7758: Use private data space from iio_allocate_device
staging:iio:accel:lis3l02dq make write_reg_8 take value not a pointer to value.
staging:iio: ring core cleanups + check if read_last available in lis3l02dq
staging:iio:core cleanup: squash tiny wrappers and use dev_set_name to handle creation of event interface name.
staging:iio: poll func allocation clean up.
staging:iio:ad7780 trivial unused header cleanup.
staging:iio:adc: AD7780: Use private data space from iio_allocate_device + trivial fixes
staging:iio:adc:AD7780: Convert to new channel registration method
staging:iio:adc: AD7606: Drop dev_data in favour of iio_priv()
staging:iio:adc: AD7606: Consitently use indio_dev
staging:iio: Rip out helper for software rings.
staging:iio:adc:AD7298: Use private data space from iio_allocate_device
staging:iio: rationalization of different buffer implementation hooks.
staging:iio:imu:adis16400 avoid allocating rx, tx, and state separately from iio_dev.
...
Fix up trivial conflicts in
- drivers/staging/intel_sst/intelmid.c: patches applied in both branches
- drivers/staging/rt2860/common/cmm_data_{pci,usb}.c: removed vs spelling
- drivers/staging/usbip/vhci_sysfs.c: trivial header file inclusion
The function is_exported() with its helper function lookup_symbol() are used to
verify if a provided symbol is effectively exported by the kernel or by the
modules. Now that both have their symbols sorted we can replace a linear search
with a binary search which provide a considerably speed-up.
This work was supported by a hardware donation from the CE Linux Forum.
Signed-off-by: Alessio Igor Bogani <abogani@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Takes advantage of the order and locates symbols using binary search.
This work was supported by a hardware donation from the CE Linux Forum.
Signed-off-by: Alessio Igor Bogani <abogani@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Dirk Behme <dirk.behme@googlemail.com>
Instead of having a callback function for each symbol in the kernel,
have a callback for each array of symbols.
This eases the logic when we move to sorted symbols and binary search.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Alessio Igor Bogani <abogani@kernel.org>
Split the unprotect function into a function per section to make
the code more readable and add the missing static declaration.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
While debugging I stumbled over two problems in the code that protects module
pages.
First issue is that disabling the protection before freeing init or unload of
a module is not symmetric with the enablement. For instance, if pages are set
to RO the page range from module_core to module_core + core_ro_size is
protected. If a module is unloaded the page range from module_core to
module_core + core_size is set back to RW.
So pages that were not set to RO are also changed to RW.
This is not critical but IMHO it should be symmetric.
Second issue is that while set_memory_rw & set_memory_ro are used for
RO/RW changes only set_memory_nx is involved for NX/X. One would await that
the inverse function is called when the NX protection should be removed,
which is not the case here, unless I'm missing something.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reset mod->init_ro_size to zero after the init part of a module is unloaded.
Otherwise we need to check if module->init is NULL in the unprotect functions
in the next patch.
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Fix function prototype to be ANSI-C compliant, consistent with other
function prototypes, addressing a sparse warning.
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Driver modules from the staging directory are marked 'tainted'
by module.c. Subsequently, tainted modules are denied dynamic
debugging. This is unwanted behavior, since staging modules should
be able to use the dynamic debugging mechanism.
Please merge this also into the staging-linus branch.
Signed-off-by: Roland Vossen <rvossen@broadcom.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In an effort to reduce kernel address leaks that might be used to help
target kernel privilege escalation exploits, this patch uses %pK when
displaying addresses in /proc/kallsyms, /proc/modules, and
/sys/module/*/sections/*.
Note that this changes %x to %p, so some legitimately 0 values in
/proc/kallsyms would have changed from 00000000 to "(null)". To avoid
this, "(null)" is not used when using the "K" format. Anything that was
already successfully parsing "(null)" in addition to full hex digits
should have no problem with this change. (Thanks to Joe Perches for the
suggestion.) Due to the %x to %p, "void *" casts are needed since these
addresses are already "unsigned long" everywhere internally, due to their
starting life as ELF section offsets.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Cc: Eugene Teo <eugene@redhat.com>
Cc: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
The commit:
84e1c6bb38
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>
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>
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 1ba28e02a1
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>
Building with CONFIG_KALLSYMS=n gives following warning:
/mnt/src/linux-git/kernel/module.c: In function ‘post_relocation’:
/mnt/src/linux-git/kernel/module.c:2534:2: warning: passing argument 2 of ‘add_kallsyms’ discards qualifiers from pointer target type
/mnt/src/linux-git/kernel/module.c:2038:13: note: expected ‘struct load_info *’ but argument is of type ‘const struct load_info *’
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.
However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling. That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.
Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.
So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.
Future fixups:
- move the module list handling code into kernel/module.c where it
belongs.
- get rid of 'module_bug_list' and just use the regular list of modules
(called 'modules' - imagine that) that we already create and maintain
for other reasons.
Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>
[ cleaned up some formating ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
On my (32-bit x86) machine, sys_init_module() uses 124 bytes of stack
once load_module() is inlined.
This effectively reverts ffb4ba76 which inlined it due to stack
pressure.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This simply hoists more code out of load_module; we also put the
identification of the extable and dynamic debug table in with the
others in find_module_sections().
We move the taint check to the actual add/remove of the dynamic debug
info: this is certain (find_module_sections is too early).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Yehuda Sadeh <yehuda@hq.newdream.net>
Instead of copying and allocating the args and storing it in
load_info, we can just allocate them right before we need them.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pass the struct load_info into all the other functions in module
loading. This neatens things and makes them more consistent.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Restore the stub module_remove_modinfo_attrs, remove the now-unused
!CONFIG_SYSFS module_sysfs_init.
Also, rename mod_kobject_remove() to mod_sysfs_teardown() as
it is the logical counterpart to mod_sysfs_setup now.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We change the sysfs functions to take struct load_info, and call
them all in mod_sysfs_setup().
We also clean up the #ifdefs a little.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
layout_and_allocate() does everything up to and including the final
struct module placement inside the allocated module memory. We have
to store the symbol layout information in our struct load_info though.
This avoids the nasty code we had before where 'mod' pointed first
to the version inside the temporary allocation containing the entire
file, then later was moved to point to the real struct module: now
the main code only ever sees the final module address.
(Includes fix for the Tony Luck-found Linus-diagnosed failure path
error).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Andrew had the sole pleasure of tickling this bug in linux-next; when we set
up "info->strtab" it's pointing into the temporary copy of the module. For
most uses that is fine, but kallsyms keeps a pointer around during module
load (inside mod->strtab).
If we oops for some reason inside a module's init function, kallsyms will use
the mod->strtab pointer into the now-freed temporary module copy.
(Later oopses work fine: after init we overwrite mod->strtab to point to a
compacted core-only strtab).
Reported-by: Andrew "Grumpy" Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty "Buggy" Russell <rusty@rustcorp.com.au>
Tested-by: Andrew "Happy" Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Put all the "rewrite and check section headers" in one place. This
adds another iteration over the sections, but it's far clearer. We
iterate once for every find_section() so we already iterate over many
times.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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>
And now that I'm looking at that call-chain (to see if it would make sense
to use some other more specific lock - doesn't look like it: all the
readers are using RCU and this is the only writer), I also give you this
trivial one-liner. It changes each_symbol() to not put that constant array
on the stack, resulting in changing
movq $C.388.31095, %rsi #, tmp85
subq $376, %rsp #,
movq %rdi, %rbx # fn, fn
leaq -208(%rbp), %rdi #, tmp84
movq %rbx, %rdx # fn,
rep movsl
xorl %esi, %esi #
leaq -208(%rbp), %rdi #, tmp87
movq %r12, %rcx # data,
call each_symbol_in_section.clone.0 #
into
xorl %esi, %esi #
subq $216, %rsp #,
movq %rdi, %rbx # fn, fn
movq $arr.31078, %rdi #,
call each_symbol_in_section.clone.0 #
which is not so much about being obviously shorter and simpler because we
don't unnecessarily copy that constant array around onto the stack, but
also about having a much smaller stack footprint (376 vs 216 bytes - see
the update of 'rsp').
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
1) Extract out the relocation loop into apply_relocations
2) Extract license and version checks into check_module_license_and_versions
3) Extract icache flushing into flush_module_icache
4) Move __obsparm warning into find_module_sections
5) Move license setting into check_modinfo.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Allocate references inside module_unload_init(), clean up inside
module_unload_free().
This version fixed to do allocation before __this_cpu_write, thanks to
bug reports from linux-next from Dave Young <hidave.darkstar@gmail.com>
and Stephen Rothwell <sfr@canb.auug.org.au>.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Here's a second one. It's slightly less trivial - since we now have error
cases - and equally untested so it may well be totally broken. But it also
cleans up a bit more, and avoids one of the goto targets, because the
"move_module()" helper now does both allocations or none.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I'd start from the trivial stuff. There's a fair amount of straight-line
code that just makes the function hard to read just because you have to
page up and down so far. Some of it is trivial to just create a helper
function for.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
No need to clear mod->refptr in module_unload_init(), since
alloc_percpu() already clears allocated chunks.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed unused var)
The command
echo "file ec.c +p" >/sys/kernel/debug/dynamic_debug/control
causes an oops.
Move the call to ddebug_remove_module() down into free_module(). In this
way it should be called from all error paths. Currently, we are missing
the remove if the module init routine fails.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Reported-by: Thomas Renninger <trenn@suse.de>
Tested-by: Thomas Renninger <trenn@suse.de>
Cc: <stable@kernel.org> [2.6.32+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We should initialize the module dynamic debug datastructures
only after determining that the module is not loaded yet. This
fixes a bug that introduced in 2.6.35-rc2, where when a trying
to load a module twice, we also load it's dynamic printing data
twice which causes all sorts of nasty issues. Also handle
the dynamic debug cleanup later on failure.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed a #ifdef)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Problem: it's hard to avoid an init routine stumbling over a
request_module these days. And it's not clear it's always a bad idea:
for example, a module like kvm with dynamic dependencies on kvm-intel
or kvm-amd would be neater if it could simply request_module the right
one.
In this particular case, it's libcrc32c:
libcrc32c_mod_init
crypto_alloc_shash
crypto_alloc_tfm
crypto_find_alg
crypto_alg_mod_lookup
crypto_larval_lookup
request_module
If another module is waiting inside resolve_symbol() for libcrc32c to
finish initializing (ie. bne2 depends on libcrc32c) then it does so
holding the module lock, and our request_module() can't make progress
until that is released.
Waiting inside resolve_symbol() without the lock isn't all that hard:
we just need to pass the -EBUSY up the call chain so we can sleep
where we don't hold the lock. Error reporting is a bit trickier: we
need to copy the name of the unfinished module before releasing the
lock.
Other notes:
1) This also fixes a theoretical issue where a weak dependency would allow
symbol version mismatches to be ignored.
2) We rename use_module to ref_module to make life easier for the only
external user (the out-of-tree ksplice patches).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tim Abbot <tabbott@ksplice.com>
Tested-by: Brandon Philips <bphilips@suse.de>
It disabled preempt so it was "safe", but nothing stops another module
slipping in before this module is added to the global list now we don't
hold the lock the whole time.
So we check this just after we check for duplicate modules, and just
before we put the module in the global list.
(find_symbol finds symbols in coming and going modules, too).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I think Rusty may have made the lock a bit _too_ finegrained there, and
didn't add it to some places that needed it. It looks, for example, like
PATCH 1/2 actually drops the lock in places where it's needed
("find_module()" is documented to need it, but now load_module() didn't
hold it at all when it did the find_module()).
Rather than adding a new "module_loading" list, I think we should be able
to just use the existing "modules" list, and just fix up the locking a
bit.
In fact, maybe we could just move the "look up existing module" a bit
later - optimistically assuming that the module doesn't exist, and then
just undoing the work if it turns out that we were wrong, just before
adding ourselves to the list.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Kay Sievers <kay.sievers@vrfy.org> reports that we still have some
contention over module loading which is slowing boot.
Linus also disliked a previous "drop lock and regrab" patch to fix the
bne2 "gave up waiting for init of module libcrc32c" message.
This is more ambitious: we only grab the lock where we need it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Brandon Philips <brandon@ifup.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
These were placed in the header in ef665c1a06 to get the various
SYSFS/MODULE config combintations to compile.
That may have been necessary then, but it's not now. These functions
are all local to module.c.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
This means a little extra work, but is more logical: we don't put
anything in sysfs until we're about to put the module into the
global list an parse its parameters.
This also gives us a logical place to put duplicate module detection
in the next patch.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Linus changed the structure, and luckily this didn't compile any more.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Martin Hicks <mort@sgi.com>
When adding a module that depends on another one, we used to create a
one-way list of "modules_which_use_me", so that module unloading could
see who needs a module.
It's actually quite simple to make that list go both ways: so that we
not only can see "who uses me", but also see a list of modules that are
"used by me".
In fact, we always wanted that list in "module_unload_free()": when we
unload a module, we want to also release all the other modules that are
used by that module. But because we didn't have that list, we used to
first iterate over all modules, and then iterate over each "used by me"
list of that module.
By making the list two-way, we simplify module_unload_free(), and it
allows for some trivial fixes later too.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleaned & rebased)
* 'for-35' of git://repo.or.cz/linux-kbuild: (81 commits)
kbuild: Revert part of e8d400a to resolve a conflict
kbuild: Fix checking of scm-identifier variable
gconfig: add support to show hidden options that have prompts
menuconfig: add support to show hidden options which have prompts
gconfig: remove show_debug option
gconfig: remove dbg_print_ptype() and dbg_print_stype()
kconfig: fix zconfdump()
kconfig: some small fixes
add random binaries to .gitignore
kbuild: Include gen_initramfs_list.sh and the file list in the .d file
kconfig: recalc symbol value before showing search results
.gitignore: ignore *.lzo files
headerdep: perlcritic warning
scripts/Makefile.lib: Align the output of LZO
kbuild: Generate modules.builtin in make modules_install
Revert "kbuild: specify absolute paths for cscope"
kbuild: Do not unnecessarily regenerate modules.builtin
headers_install: use local file handles
headers_check: fix perl warnings
export_report: fix perl warnings
...
Rafael sees a sometimes crash at precpu_modfree from kernel/module.c; it
only occurred with another (since-reverted) patch, but that patch simply
changed timing to uncover this bug, it was otherwise unrelated.
The comment about the mod being freed is self-explanatory, but neither
Tejun nor I read it. This bug was introduced in 259354deaa, after it
had previously been fixed in 6e2b75740b. How embarrassing.
Reported-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Embarrassingly-Acked-by: Tejun Heo <tj@kernel.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Tested-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 480b02df3a, since
Rafael reports that it causes occasional kernel paging request faults in
load_module().
Dropping the module lock and re-taking it deep in the call-chain is
definitely not the right thing to do. That just turns the mutex from a
lock into a "random non-locking data structure" that doesn't actually
protect what it's supposed to protect.
Requested-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Brandon Philips <brandon@ifup.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'modules' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
module: drop the lock while waiting for module to complete initialization.
MODULE_DEVICE_TABLE(isapnp, ...) does nothing
hisax_fcpcipnp: fix broken isapnp device table.
isapnp: move definitions to mod_devicetable.h so file2alias can reach them.
* 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: (25 commits)
kdb,debug_core: Allow the debug core to receive a panic notification
MAINTAINERS: update kgdb, kdb, and debug_core info
debug_core,kdb: Allow the debug core to process a recursive debug entry
printk,kdb: capture printk() when in kdb shell
kgdboc,kdb: Allow kdb to work on a non open console port
kgdb: Add the ability to schedule a breakpoint via a tasklet
mips,kgdb: kdb low level trap catch and stack trace
powerpc,kgdb: Introduce low level trap catching
x86,kgdb: Add low level debug hook
kgdb: remove post_primary_code references
kgdb,docs: Update the kgdb docs to include kdb
kgdboc,keyboard: Keyboard driver for kdb with kgdb
kgdb: gdb "monitor" -> kdb passthrough
sparc,sunzilog: Add console polling support for sunzilog serial driver
sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code
kgdb,8250,pl011: Return immediately from console poll
kgdb: core changes to support kdb
kdb: core for kgdb back end (2 of 2)
kdb: core for kgdb back end (1 of 2)
kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin
...
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch contains the hooks and instrumentation into kernel which
live outside the kernel/debug directory, which the kdb core
will call to run commands like lsmod, dmesg, bt etc...
CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
This fixes "gave up waiting for init of module libcrc32c." which
happened at boot time due to multiple parallel module loads.
The problem was a deadlock: we wait for a module to finish
initializing, but we keep the module_lock mutex so it can't complete.
In particular, this could reasonably happen if a module does a
request_module() in its initialization routine.
So we change use_module() to return an errno rather than a bool, and if
it's -EBUSY we drop the lock and wait in the caller, then reaquire the
lock.
Reported-by: Brandon Philips <brandon@ifup.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Brandon Philips <brandon@ifup.org>
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback()
sched, wait: Use wrapper functions
sched: Remove a stale comment
ondemand: Make the iowait-is-busy time a sysfs tunable
ondemand: Solve a big performance issue by counting IOWAIT time as busy
sched: Intoduce get_cpu_iowait_time_us()
sched: Eliminate the ts->idle_lastupdate field
sched: Fold updating of the last_update_time_info into update_ts_time_stats()
sched: Update the idle statistics in get_cpu_idle_time_us()
sched: Introduce a function to update the idle statistics
sched: Add a comment to get_cpu_idle_time_us()
cpu_stop: add dummy implementation for UP
sched: Remove rq argument to the tracepoints
rcu: need barrier() in UP synchronize_sched_expedited()
sched: correctly place paranioa memory barriers in synchronize_sched_expedited()
sched: kill paranoia check in synchronize_sched_expedited()
sched: replace migration_thread with cpu_stop
stop_machine: reimplement using cpu_stop
cpu_stop: implement stop_cpu[s]()
sched: Fix select_idle_sibling() logic in select_task_rq_fair()
...
Reimplement stop_machine using cpu_stop. As cpu stoppers are
guaranteed to be available for all online cpus,
stop_machine_create/destroy() are no longer necessary and removed.
With resource management and synchronization handled by cpu_stop, the
new implementation is much simpler. Asking the cpu_stop to execute
the stop_cpu() state machine on all online cpus with cpu hotplug
disabled is enough.
stop_machine itself doesn't need to manage any global resources
anymore, so all per-instance information is rolled into struct
stop_machine_data and the mutex and all static data variables are
removed.
The previous implementation created and destroyed RT workqueues as
necessary which made stop_machine() calls highly expensive on very
large machines. According to Dimitri Sivanich, preventing the dynamic
creation/destruction makes booting faster more than twice on very
large machines. cpu_stop resources are preallocated for all online
cpus and should have the same effect.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Module refcounting is implemented with a per-cpu counter for speed.
However there is a race when tallying the counter where a reference may
be taken by one CPU and released by another. Reference count summation
may then see the decrement without having seen the previous increment,
leading to lower than expected count. A module which never has its
actual reference drop below 1 may return a reference count of 0 due to
this race.
Module removal generally runs under stop_machine, which prevents this
race causing bugs due to removal of in-use modules. However there are
other real bugs in module.c code and driver code (module_refcount is
exported) where the callers do not run under stop_machine.
Fix this by maintaining running per-cpu counters for the number of
module refcount increments and the number of refcount decrements. The
increments are tallied after the decrements, so any decrement seen will
always have its corresponding increment counted. The final refcount is
the difference of the total increments and decrements, preventing a
low-refcount from being returned.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If modules are configured in the build but unloading of modules is not,
then the refcnt is not defined. Place the get/put module tracepoints
under CONFIG_MODULE_UNLOAD since it references this field in the module
structure.
As a side-effect, this patch also reduces the code when MODULE_UNLOAD
is not set, because these unused tracepoints are not created.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Remove the @refcnt argument, because it has side-effects, and arguments with
side-effects are not skipped by the jump over disabled instrumentation and are
executed even when the tracepoint is disabled.
This was also causing a GPF as found by Randy Dunlap:
Subject: 2.6.33 GP fault only when built with tracing
LKML-Reference: <4BA2B69D.3000309@oracle.com>
Note, the current 2.6.34-rc has a fix for the actual cause of the GPF,
but this fixes one of its triggers.
Tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BA97FA7.6040406@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
lockdep has custom code to check whether a pointer belongs to static
percpu area which is somewhat broken. Implement proper
is_kernel/module_percpu_address() and replace the custom code.
On UP, percpu variables are regular static variables and can't be
distinguished from them. Always return %false on UP.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Better encapsulate module static percpu area handling so that code
outsidef of CONFIG_SMP ifdef doesn't deal with mod->percpu directly
and add mod->percpu_size and record percpu_size in it. Both percpu
fields are compiled out on UP. While at it, mark mod->percpu w/
__percpu.
This is to prepare for is_module_percpu_address().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
A little more whack-a-mole annotating the dynamic sysfs attributes. I
had everything built into my earlier test kernel, and so I missed
these.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 35dead4 "modules: don't export section names of empty sections
via sysfs" changed the set of sections that have attributes, but did
not change the iteration over these attributes in add_notes_attrs().
This can lead to add_notes_attrs() creating attributes with the wrong
names or with null name pointers.
Introduce a sect_empty() function and use it in both add_sect_attrs()
and add_notes_attrs().
Reported-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Tested-by: Martin Michlmayr <tbm@cyrius.com>
Cc: stable@kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use cpu ops to deal with the per cpu data instead of a local_t. Reduces memory
requirements, cache footprint and decreases cycle counts.
The this_cpu_xx operations are also used for !SMP mode. Otherwise we could
not drop the use of __module_ref_addr() which would make per cpu data handling
complicated. this_cpu_xx operations have their own fallback for !SMP.
V8-V9:
- Leave include asm/module.h since ringbuffer.c depends on it. Nothing else
does though. Another patch will deal with that.
- Remove spurious free.
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
* 'kmemleak' of git://linux-arm.org/linux-2.6:
kmemleak: fix kconfig for crc32 build error
kmemleak: Reduce the false positives by checking for modified objects
kmemleak: Show the age of an unreferenced object
kmemleak: Release the object lock before calling put_object()
kmemleak: Scan the _ftrace_events section in modules
kmemleak: Simplify the kmemleak_scan_area() function prototype
kmemleak: Do not use off-slab management with SLAB_NOLEAKTRACE
powerpc applies relocations to the kcrctab. They're absolute symbols,
but it's not completely unreasonable: other archs may too, but the
relocation is often 0.
http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077972.html
Inspired-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Paul Mackerras <paulus@samba.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
m68k: rename global variable vmalloc_end to m68k_vmalloc_end
percpu: add missing per_cpu_ptr_to_phys() definition for UP
percpu: Fix kdump failure if booted with percpu_alloc=page
percpu: make misc percpu symbols unique
percpu: make percpu symbols in ia64 unique
percpu: make percpu symbols in powerpc unique
percpu: make percpu symbols in x86 unique
percpu: make percpu symbols in xen unique
percpu: make percpu symbols in cpufreq unique
percpu: make percpu symbols in oprofile unique
percpu: make percpu symbols in tracer unique
percpu: make percpu symbols under kernel/ and mm/ unique
percpu: remove some sparse warnings
percpu: make alloc_percpu() handle array types
vmalloc: fix use of non-existent percpu variable in put_cpu_var()
this_cpu: Use this_cpu_xx in trace_functions_graph.c
this_cpu: Use this_cpu_xx for ftrace
this_cpu: Use this_cpu_xx in nmi handling
this_cpu: Use this_cpu operations in RCU
this_cpu: Use this_cpu ops for VM statistics
...
Fix up trivial (famous last words) global per-cpu naming conflicts in
arch/x86/kvm/svm.c
mm/slab.c
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>
This section contains pointers to allocated objects and not scanning it
leads to false positives.
Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This function was taking non-necessary arguments which can be determined
by kmemleak. The patch also modifies the calling sites.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
With ia64 converted, there's no arch left which still uses legacy
percpu allocator. Kill it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Delightedly-acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Starting from commit 4a4962263f "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>
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
modules, tracing: Remove stale struct marker signature from module_layout()
tracing/workqueue: Use %pf in workqueue trace events
tracing: Fix a comment and a trivial format issue in tracepoint.h
tracing: Fix failure path in ftrace_regex_open()
tracing: Fix failure path in ftrace_graph_write()
tracing: Check the return value of trace_get_user()
tracing: Fix off-by-one in trace_get_user()
The general one handles NULL, the static obsolescent
(CONFIG_HAVE_LEGACY_PER_CPU_AREA) one in module.c doesn't; Eric's
commit 720eba31 assumed it did, and various frobbings since then kept
that assumption.
All other callers in module.c all protect it with an if; this effectively
does the same as free_init is only goto if we fail percpu_modalloc().
Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Américo Wang <xiyou.wangcong@gmail.com>
Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Normally the twisty paths of sysfs will free the attributes, but not if
we fail before we hook it into sysfs (which is the last thing we do in
load_module).
(This sysfs code is a turd, no doubt there are other issues lurking too).
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Also remove all parts of the string table (referenced by the symbol
table) that are not needed for kallsyms use (i.e. which were only
referenced by symbols discarded by the previous patch, or not
referenced at all for whatever reason).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Discard all symbols not interesting for kallsyms use: absolute,
section, and in the common case (!KALLSYMS_ALL) data ones.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Linus reported this new build warning:
kernel/module.c:2951: warning: ?struct marker? declared inside parameter list
kernel/module.c:2951: warning: its scope is only this definition or declaration, which is probably not what you want
Caused by:
fc53776: tracing: Remove markers
module_layout() is an artificial symbol with 'significant' symbols
listed in its argument list so that it gets a proper argument types
signature that modversions can pick up to decide whether a
module is version-compatible or not. If these dont match then we
wont even look at a module.
Remove the stale marker symbol.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <alpine.LFD.2.01.0909210908020.4950@localhost.localdomain>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some architectures (like the Blackfin arch) implement some of the
"simpler" features that one would expect out of a MMU such as memory
protection.
In our case, we actually get read/write/exec protection down to the page
boundary so processes can't stomp on each other let alone the kernel.
There is a performance decrease (which depends greatly on the workload)
however as the hardware/software interaction was not optimized at design
time.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the last users of markers have migrated to the event
tracer we can kill off the (now orphan) support code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090917173527.GA1699@lst.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
powerpc64: convert to dynamic percpu allocator
sparc64: use embedding percpu first chunk allocator
percpu: kill lpage first chunk allocator
x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
percpu: update embedding first chunk allocator to handle sparse units
percpu: use group information to allocate vmap areas sparsely
vmalloc: implement pcpu_get_vm_areas()
vmalloc: separate out insert_vmalloc_vm()
percpu: add chunk->base_addr
percpu: add pcpu_unit_offsets[]
percpu: introduce pcpu_alloc_info and pcpu_group_info
percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
percpu: add @align to pcpu_fc_alloc_fn_t
percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
percpu: drop @static_size from first chunk allocators
percpu: generalize first chunk allocator selection
percpu: build first chunk allocators selectively
percpu: rename 4k first chunk allocator to page
percpu: improve boot messages
percpu: fix pcpu_reclaim() locking
...
Fix trivial conflict as by Tejun Heo in kernel/sched.c
> James Bottomley (1):
> module: workaround duplicate section names
-tip testing found that this patch breaks the build on x86 if
CONFIG_KALLSYMS is disabled:
kernel/module.c: In function ‘load_module’:
kernel/module.c:2367: error: ‘struct module’ has no member named ‘sect_attrs’
distcc[8269] ERROR: compile kernel/module.c on ph/32 failed
make[1]: *** [kernel/module.o] Error 1
make: *** [kernel] Error 2
make: *** Waiting for unfinished jobs....
Commit 1b364bf misses the fact that section attributes are only
built and dealt with if kallsyms is enabled. The patch below fixes
this.
( note, technically speaking this should depend on CONFIG_SYSFS as
well but this patch is correct too and keeps the #ifdef less
intrusive - in the KALLSYMS && !SYSFS case the code is a NOP. )
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Replaced patch with a slightly cleaner variation by James Bottomley ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The root cause is a duplicate section name (.text); is this legal?
[ Amerigo Wang: "AFAIK, yes." ]
However, there's a problem with commit
6d76013381 in that if you fail to allocate
a mod->sect_attrs (in this case it's null because of the duplication),
it still gets used without checking in add_notes_attrs()
This should fix it
[ This patch leaves other problems, particularly the sections directory,
but recent parisc toolchains seem to produce these modules and this
prevents a crash and is a minimal change -- RR ]
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The rarely-used symbol_put_addr() needs to use dereference_function_descriptor
on powerpc.
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Conflicts:
arch/sparc/kernel/smp_64.c
arch/x86/kernel/cpu/perf_counter.c
arch/x86/kernel/setup_percpu.c
drivers/cpufreq/cpufreq_ondemand.c
mm/percpu.c
Conflicts in core and arch percpu codes are mostly from commit
ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many
num_possible_cpus() with nr_cpu_ids. As for-next branch has moved all
the first chunk allocators into mm/percpu.c, the changes are moved
from arch code to mm/percpu.c.
Signed-off-by: Tejun Heo <tj@kernel.org>
The check_modstruct_version() needs to look up the symbol "module_layout"
in the kernel, but it does so literally and not by a C identifier. The
trouble is that it does not include a symbol prefix for those ports that
need it (like the Blackfin and H8300 port). So make sure we tack on the
MODULE_SYMBOL_PREFIX define to the front of it.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics. printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.
<level> is now included in the output on each additional use.
Remove all uses of multiple KERN_<level>s in formats.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes most !CONFIG_HAVE_SETUP_PER_CPU_AREA archs use
dynamic percpu allocator. The first chunk is allocated using
embedding helper and 8k is reserved for modules. This ensures that
the new allocator behaves almost identically to the original allocator
as long as static percpu variables are concerned, so it shouldn't
introduce much breakage.
s390 and alpha use custom SHIFT_PERCPU_PTR() to work around addressing
range limit the addressing model imposes. Unfortunately, this breaks
if the address is specified using a variable, so for now, the two
archs aren't converted.
The following architectures are affected by this change.
* sh
* arm
* cris
* mips
* sparc(32)
* blackfin
* avr32
* parisc (broken, under investigation)
* m32r
* powerpc(32)
As this change makes the dynamic allocator the default one,
CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is replaced with its invert -
CONFIG_HAVE_LEGACY_PER_CPU_AREA, which is added to yet-to-be converted
archs. These archs implement their own setup_per_cpu_areas() and the
conversion is not trivial.
* powerpc(64)
* sparc(64)
* ia64
* alpha
* s390
Boot and batch alloc/free tests on x86_32 with debug code (x86_32
doesn't use default first chunk initialization). Compile tested on
sparc(32), powerpc(32), arm and alpha.
Kyle McMartin reported that this change breaks parisc. The problem is
still under investigation and he is okay with pushing this patch
forward and fixing parisc later.
[ Impact: use dynamic allocator for most archs w/o custom percpu setup ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Call constructors (gcc-generated initcall-like functions) during kernel
start and module load. Constructors are e.g. used for gcov data
initialization.
Disable constructor support for usermode Linux to prevent conflicts with
host glibc.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Several WARN_ON() messages omit the '\n' at the end of the string, which
is a simple (and understandable) error. The next line printed after
that warning line is usually the current module list, and that printk
does not have a log-level marker - resulting in one long mixed-up line.
Adding this loglevel marker will now avoid this unreadable mess.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's theoretically possible that there are exception table entries
which point into the (freed) init text of modules. These could cause
future problems if other modules get loaded into that memory and cause
an exception as we'd see the wrong fixup. The only case I know of is
kvm-intel.ko (when CONFIG_CC_OPTIMIZE_FOR_SIZE=n).
Amerigo fixed this long-standing FIXME in the x86 version, but this
patch is more general.
This implements trim_init_extable(); most archs are simple since they
use the standard lib/extable.c sort code. Alpha and IA64 use relative
addresses in their fixups, so thier trimming is a slight variation.
Sparc32 is unique; it doesn't seem to define ARCH_HAS_SORT_EXTABLE,
yet it defines its own sort_extable() which overrides the one in lib.
It doesn't sort, so we have to mark deleted entries instead of
actually trimming them.
Inspired-by: Amerigo Wang <amwang@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-alpha@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
* 'for-linus' of git://linux-arm.org/linux-2.6:
kmemleak: Add the corresponding MAINTAINERS entry
kmemleak: Simple testing module for kmemleak
kmemleak: Enable the building of the memory leak detector
kmemleak: Remove some of the kmemleak false positives
kmemleak: Add modules support
kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash
kmemleak: Add the vmalloc memory allocation/freeing hooks
kmemleak: Add the slub memory allocation/freeing hooks
kmemleak: Add the slob memory allocation/freeing hooks
kmemleak: Add the slab memory allocation/freeing hooks
kmemleak: Add documentation on the memory leak detector
kmemleak: Add the base support
Manual conflict resolution (with the slab/earlyboot changes) in:
drivers/char/vt.c
init/main.c
mm/slab.c
This patch handles the kmemleak operations needed for modules loading so
that memory allocations from inside a module are properly tracked.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The hooks in the module code for the function tracer must be called
before any of that module code runs. The function tracer hooks
modify the module (replacing calls to mcount to nops). If the code
is executed while the change occurs, then the CPU can take a GPF.
To handle the above with a bit of paranoia, I originally implemented
the hooks as calls directly from the module code.
After examining the notifier calls, it looks as though the start up
notify is called before any of the module's code is executed. This makes
the use of the notify safe with ftrace.
Only the startup notify is required to be "safe". The shutdown simply
removes the entries from the ftrace function list, and does not modify
any code.
This change has another benefit. It removes a issue with a reverse dependency
in the mutexes of ftrace_lock and module_mutex.
[ Impact: fix lock dependency bug, cleanup ]
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit 3d43321b70 ("modules: sysctl to
block module loading") introduces a modules_disabled variable that is
only defined if CONFIG_MODULE_UNLOAD is enabled, despite being used in
other places. This moves it up and fixes up the build.
CC kernel/module.o
kernel/module.c: In function 'sys_init_module':
kernel/module.c:2401: error: 'modules_disabled' undeclared (first use in this function)
kernel/module.c:2401: error: (Each undeclared identifier is reported only once
kernel/module.c:2401: error: for each function it appears in.)
make[1]: *** [kernel/module.o] Error 1
make: *** [kernel/module.o] Error 2
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: James Morris <jmorris@namei.org>
Impact: allow modules to add TRACE_EVENTS on load
This patch adds the final hooks to allow modules to use the TRACE_EVENT
macro. A notifier and a data structure are used to link the TRACE_EVENTs
defined in the module to connect them with the ftrace event tracing system.
It also adds the necessary automated clean ups to the trace events when a
module is removed.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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
5d38258ec0 "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>
This reverts commit 9cb610d8e3.
This was an impressively stupid patch. Firstly, we reset the SHF_ALLOC
flag lower down in the same function, so the patch was useless. Even
better, find_sec() ignores sections with SHF_ALLOC not set, so
it breaks CONFIG_MODVERSIONS=y with CONFIG_MODULE_FORCE_LOAD=n, which
refuses to load the module since it can't find the __versions section.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
tracing, net: fix net tree and tracing tree merge interaction
tracing, powerpc: fix powerpc tree and tracing tree interaction
ring-buffer: do not remove reader page from list on ring buffer free
function-graph: allow unregistering twice
trace: make argument 'mem' of trace_seq_putmem() const
tracing: add missing 'extern' keywords to trace_output.h
tracing: provide trace_seq_reserve()
blktrace: print out BLK_TN_MESSAGE properly
blktrace: extract duplidate code
blktrace: fix memory leak when freeing struct blk_io_trace
blktrace: fix blk_probes_ref chaos
blktrace: make classic output more classic
blktrace: fix off-by-one bug
blktrace: fix the original blktrace
blktrace: fix a race when creating blk_tree_root in debugfs
blktrace: fix timestamp in binary output
tracing, Text Edit Lock: cleanup
tracing: filter fix for TRACE_EVENT_FORMAT events
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
x86: kretprobe-booster interrupt emulation code fix
...
Fix up trivial conflicts in
arch/parisc/include/asm/ftrace.h
include/linux/memory.h
kernel/extable.c
kernel/module.c
Implement a sysctl file that disables module-loading system-wide since
there is no longer a viable way to remove CAP_SYS_MODULE after the system
bounding capability set was removed in 2.6.25.
Value can only be set to "1", and is tested only if standard capability
checks allow CAP_SYS_MODULE. Given existing /dev/mem protections, this
should allow administrators a one-way method to block module loading
after initial boot-time module loading has finished.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Tejun Heo