We don't access struct cgroupfs_root in fast path, so we should not put
struct cgroupfs_root protected by RCU
But the comment in struct cgroup_subsys.root confuse us.
struct cgroup_subsys.root is used in these places:
1 find_css_set(): if (ss->root->subsys_list.next == &ss->sibling)
2 rebind_subsystems(): if (ss->root != &rootnode)
rcu_assign_pointer(ss->root, root);
rcu_assign_pointer(subsys[i]->root, &rootnode);
3 cgroup_has_css_refs(): if (ss->root != cgrp->root)
4 cgroup_init_subsys(): ss->root = &rootnode;
5 proc_cgroupstats_show(): ss->name, ss->root->subsys_bits,
ss->root->number_of_cgroups, !ss->disabled);
6 cgroup_clone(): root = subsys->root;
if ((root != subsys->root) ||
All these place we have held cgroup_lock() or we don't dereference to
struct cgroupfs_root. It's means wo don't need RCU when use struct
cgroup_subsys.root, and we should not put struct cgroupfs_root protected
by RCU.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We access res->cgroups without the task_lock(), so res->cgroups may be
changed. it's unreliable, and "if (l == &res->cgroups->tasks)" may be
false forever.
We don't need add any lock for fixing this bug. we just access to struct
css_set by struct cg_cgroup_link, not by struct task_struct.
Since we hold css_set_lock, struct cg_cgroup_link is reliable.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When cgroup_post_fork() is called, child is seen by find_task_by_vpid(),
so child->cgroups maybe be changed, It'll incorrect.
child->cgroups<old>'s refcnt is decreased
child->cgroups<new>'s refcnt is increased
but child->cg_list is added to child->cgroups<old>'s list.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I happened to find the spinlock in struct ns_cgroup is never used.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- In cgroup_clone(), if vfs_mkdir() returns successfully,
dentry->d_fsdata will be the pointer to the newly created
cgroup and won't be NULL.
- a cgroup file's dentry->d_fsdata won't be NULL, guaranteed
by cgroup_add_file().
- When walking through the subsystems of a cgroup_fs (using
for_each_subsys), cgrp->subsys[ss->subsys_id] won't be NULL,
guaranteed by cgroup_create().
(Also remove 2 unused variables in cgroup_rmdir().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix commit_creds()'s handling of a process that has no mm (such as one that is
calling or has called daemonize()). commit_creds() should check to see if
task->mm is not NULL before calling set_dumpable() on it.
Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
NOMMU mmap allocates a piece of memory for an mmap that's rounded up in size to
the nearest power-of-2 number of pages. Currently it then discards the excess
pages back to the page allocator, making that memory available for use by other
things. This can, however, cause greater amount of fragmentation.
To counter this, a sysctl is added in order to fine-tune the trimming
behaviour. The default behaviour remains to trim pages aggressively, while
this can either be disabled completely or set to a higher page-granular
watermark in order to have finer-grained control.
vm region vm_top bits taken from an earlier patch by David Howells.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Make VMAs per mm_struct as for MMU-mode linux. This solves two problems:
(1) In SYSV SHM where nattch for a segment does not reflect the number of
shmat's (and forks) done.
(2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
that a VMA might be shared and already have its vm_mm assigned to another
process or a dead process.
A new struct (vm_region) is introduced to track a mapped region and to remember
the circumstances under which it may be shared and the vm_list_struct structure
is discarded as it's no longer required.
This patch makes the following additional changes:
(1) Regions are now allocated with alloc_pages() rather than kmalloc() and
with no recourse to __GFP_COMP, so the pages are not composite. Instead,
each page has a reference on it held by the region. Anything else that is
interested in such a page will have to get a reference on it to retain it.
When the pages are released due to unmapping, each page is passed to
put_page() and will be freed when the page usage count reaches zero.
(2) Excess pages are trimmed after an allocation as the allocation must be
made as a power-of-2 quantity of pages.
(3) VMAs are added to the parent MM's R/B tree and mmap lists. As an MM may
end up with overlapping VMAs within the tree, the VMA struct address is
appended to the sort key.
(4) Non-anonymous VMAs are now added to the backing inode's prio list.
(5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
the backing region. The VMA and region structs will be split if
necessary.
(6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
segment instead of all the attachments at that addresss. Multiple
shmat()'s return the same address under NOMMU-mode instead of different
virtual addresses as under MMU-mode.
(7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
(8) /proc/maps is now the global list of mapped regions, and may list bits
that aren't actually mapped anywhere.
(9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
of RAM currently allocated by mmap to hold mappable regions that can't be
mapped directly. These are copies of the backing device or file if not
anonymous.
These changes make NOMMU mode more similar to MMU mode. The downside is that
NOMMU mode requires some extra memory to track things over NOMMU without this
patch (VMAs are no longer shared, and there are now region structs).
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (98 commits)
PCI PM: Put PM callbacks in the order of execution
PCI PM: Run default PM callbacks for all devices using new framework
PCI PM: Register power state of devices during initialization
PCI PM: Call pci_fixup_device from legacy routines
PCI PM: Rearrange code in pci-driver.c
PCI PM: Avoid touching devices behind bridges in unknown state
PCI PM: Move pci_has_legacy_pm_support
PCI PM: Power-manage devices without drivers during suspend-resume
PCI PM: Add suspend counterpart of pci_reenable_device
PCI PM: Fix poweroff and restore callbacks
PCI: Use msleep instead of cpu_relax during ASPM link retraining
PCI: PCIe portdrv: Add kerneldoc comments to remining core funtions
PCI: PCIe portdrv: Rearrange code so that related things are together
PCI: PCIe portdrv: Fix suspend and resume of PCI Express port services
PCI: PCIe portdrv: Add kerneldoc comments to some core functions
x86/PCI: Do not use interrupt links for devices using MSI-X
net: sfc: Use pci_clear_master() to disable bus mastering
PCI: Add pci_clear_master() as opposite of pci_set_master()
PCI hotplug: remove redundant test in cpq hotplug
PCI: pciehp: cleanup register and field definitions
...
* git://git.kernel.org/pub/scm/linux/kernel/git/arjan/linux-2.6-async:
async: don't do the initcall stuff post boot
bootchart: improve output based on Dave Jones' feedback
async: make the final inode deletion an asynchronous event
fastboot: Make libata initialization even more async
fastboot: make the libata port scan asynchronous
fastboot: make scsi probes asynchronous
async: Asynchronous function calls to speed up kernel boot
This patch fixes an rcutorture bug found by Eric Sesterhenn that
resulted in oopses in response to "rmmod rcutorture". The problem
was in some new code that attempted to handle the case where a system
is shut down while rcutorture is still running, for example, when
rcutorture is built into the kernel so that it cannot be removed.
The fix causes the rcutorture threads to "park" in an
schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT) rather than
trying to get them to terminate cleanly. Concurrent shutdown and
rmmod is illegal.
I believe that this is 2.6.29 material, as it is used in some testing
setups.
For reference, here are the rcutorture operating modes:
CONFIG_RCU_TORTURE_TEST=m
This is the normal rcutorture build. Use "modprobe rcutorture"
(with optional arguments) to start, and "rmmod rcutorture" to
stop. If you shut the system down without doing the rmmod, you
should see console output like:
rcutorture thread rcu_torture_writer parking due to system shutdown
One for each rcutorture kthread.
CONFIG_RCU_TORTURE_TEST=y
CONFIG_RCU_TORTURE_TEST_RUNNABLE=n
Use this if you want rcutorture built in, but don't want the
test to start running during early boot. To start the
torturing:
echo 1 > /proc/sys/kernel/rcutorture_runnable
To stop the torturing, s/1/0/
You will get "parking" console messages as noted above when
you shut the system down.
CONFIG_RCU_TORTURE_TEST=y
CONFIG_RCU_TORTURE_TEST_RUNNABLE=y
Same as above, except that the torturing starts during early
boot. Only for the stout of heart and strong of stomach.
The same /proc entry noted above may be used to control the
test.
Located-by: Eric Sesterhenn <snakebyte@gmx.de>
Tested-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Function ring_buffer_event_length() provides an interface to detect
the length of data stored in an entry. However, the length contains
offsets depending on the internal usage. This makes it unusable. This
patch fixes this and now ring_buffer_event_length() returns the
alligned length that has been used in ring_buffer_lock_reserve().
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
trivial: chack -> check typo fix in main Makefile
trivial: Add a space (and a comma) to a printk in 8250 driver
trivial: Fix misspelling of "firmware" in docs for ncr53c8xx/sym53c8xx
trivial: Fix misspelling of "firmware" in powerpc Makefile
trivial: Fix misspelling of "firmware" in usb.c
trivial: Fix misspelling of "firmware" in qla1280.c
trivial: Fix misspelling of "firmware" in a100u2w.c
trivial: Fix misspelling of "firmware" in megaraid.c
trivial: Fix misspelling of "firmware" in ql4_mbx.c
trivial: Fix misspelling of "firmware" in acpi_memhotplug.c
trivial: Fix misspelling of "firmware" in ipw2100.c
trivial: Fix misspelling of "firmware" in atmel.c
trivial: Fix misspelled firmware in Kconfig
trivial: fix an -> a typos in documentation and comments
trivial: fix then -> than typos in comments and documentation
trivial: update Jesper Juhl CREDITS entry with new email
trivial: fix singal -> signal typo
trivial: Fix incorrect use of "loose" in event.c
trivial: printk: fix indentation of new_text_line declaration
trivial: rtc-stk17ta8: fix sparse warning
...
Device drivers that use pci_request_regions() (and similar APIs) have a
reasonable expectation that they are the only ones accessing their device.
As part of the e1000e hunt, we were afraid that some userland (X or some
bootsplash stuff) was mapping the MMIO region that the driver thought it
had exclusively via /dev/mem or via various sysfs resource mappings.
This patch adds the option for device drivers to cause their reserved
regions to the "banned from /dev/mem use" list, so now both kernel memory
and device-exclusive MMIO regions are banned.
NOTE: This is only active when CONFIG_STRICT_DEVMEM is set.
In addition to the config option, a kernel parameter iomem=relaxed is
provided for the cases where developers want to diagnose, in the field,
drivers issues from userspace.
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
while tracking the asynchronous calls during boot using the initcall_debug
convention is useful, doing it once the kernel is done is actually
bad now that we use asynchronous operations post boot as well...
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Right now, most of the kernel boot is strictly synchronous, such that
various hardware delays are done sequentially.
In order to make the kernel boot faster, this patch introduces
infrastructure to allow doing some of the initialization steps
asynchronously, which will hide significant portions of the hardware delays
in practice.
In order to not change device order and other similar observables, this
patch does NOT do full parallel initialization.
Rather, it operates more in the way an out of order CPU does; the work may
be done out of order and asynchronous, but the observable effects
(instruction retiring for the CPU) are still done in the original sequence.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Vaidyanathan Srinivasan reported:
> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.28-autotest-tip-sv #1
> ---------------------------------------------
> klogd/5062 is trying to acquire lock:
> (&rq->lock){++..}, at: [<ffffffff8022aca2>] task_rq_lock+0x45/0x7e
>
> but task is already holding lock:
> (&rq->lock){++..}, at: [<ffffffff805f7354>] schedule+0x158/0xa31
With sched_mc at 2. (it is default-off)
Strictly speaking we'll not deadlock, because ttwu will not be able to
place the migration task on our rq, but since the code can deal with
both rqs getting unlocked, this seems the easiest way out.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #3]
Revert "CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]"
SELinux: shrink sizeof av_inhert selinux_class_perm and context
CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]
keys: fix sparse warning by adding __user annotation to cast
smack: Add support for unlabeled network hosts and networks
selinux: Deprecate and schedule the removal of the the compat_net functionality
netlabel: Update kernel configuration API
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: fix section mismatch
sched: fix double kfree in failure path
sched: clean up arch_reinit_sched_domains()
sched: mark sched_create_sysfs_power_savings_entries() as __init
getrusage: RUSAGE_THREAD should return ru_utime and ru_stime
sched: fix sched_slice()
sched_clock: prevent scd->clock from moving backwards, take #2
sched: sched.c declare variables before they get used
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: fix rcutorture bug
rcu: eliminate synchronize_rcu_xxx macro
rcu: make treercu safe for suspend and resume
rcu: fix rcutree grace-period-latency bug on small systems
futex: catch certain assymetric (get|put)_futex_key calls
futex: make futex_(get|put)_key() calls symmetric
locking, percpu counters: introduce separate lock classes
swiotlb: clean up EXPORT_SYMBOL usage
swiotlb: remove unnecessary declaration
swiotlb: replace architecture-specific swiotlb.h with linux/swiotlb.h
swiotlb: add support for systems with highmem
swiotlb: store phys address in io_tlb_orig_addr array
swiotlb: add hwdev to swiotlb_phys_to_bus() / swiotlb_sg_to_bus()
Prevent passing an order to bitmap_find_free_region() that is larger than
the actual bitmap can represent.
These requests can come from device drivers that have no idea how big the
dma region is and need to rely on dma_alloc_from_coherent() to sort it out
for them.
Reported-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This thing was rather stupidly coded. Rework it all prior to making
changes.
Also, rename local variable `page': kernel readers expect something called
`page' to have type `struct page *'.
Cc: Guennadi Liakhovetski <lg@denx.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If bitmap_find_free_region() fails and DMA_MEMORY_EXCLUSIVE is not set,
the function will fail to write anything to *ret and will return 1. This will cause dma_alloc_coherent() to return an uninitialised value,
crashing the kernel, perhaps via DMA to a random address.
Fix that by changing it to return zero in this case, so the caller will
proceed to allocate the memory from the generic memory allocator.
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a new kernel parameter `coredump_filter'. Setting a value to
this parameter causes the default bitmask of coredump_filter to be
changed.
It is useful for users to change coredump_filter settings for the whole
system at boot time. Without this parameter, users have to change
coredump_filter settings for each /proc/<pid>/ in an initializing script.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
POSIX requires the si_pid to be the process id of the sender, so ->si_pid
should really be set to 'tgid'. This change does have following changes
in behavior:
- When sending pdeath_signal on re-parent to a sub-thread, ->si_pid
cannot be used to identify the thread that did the re-parent since
it will now show the tgid instead of thread id.
- A multi-threaded application that expects to find the specific
thread that encountered a SIGPIPE using the ->si_pid will now
break.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-By: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For SEND_SIG_NOINFO, si_pid is currently set to the pid of sender
in sender's active pid namespace. But if the receiver is in a
Eg: when parent sends the 'pdeath_signal' to a child that is in
a descendant pid namespace, we should set si_pid 0.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-By: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix varargs kernel-doc format in kmod.c:
Use @... instead of @varargs.
Warning(kernel/kmod.c:67): Excess function parameter or struct member 'varargs' description in 'request_module'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.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>
Allow kprobes to probe module __init routines. When __init functions are
freed, kprobes which probe those functions are set to "Gone" flag. These
"Gone" probes are disarmed from the code and never be enabled.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a module notifier call which notifies that the state of a module
changes from MODULE_STATE_COMING to MODULE_STATE_LIVE.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove called_from argument from kprobes which had been used for
preventing self-refering of kernel module. However, since we don't keep
module's refcount after registering kprobe any more, there is no reason to
check that.
This patch also simplifies registering/unregistering functions because we
don't need to use __builtin_return_address(0) which was passed to
called_from.
[ananth@in.ibm.com: build fix]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allows kprobes to probe __exit routine. This adds flags member to struct
kprobe. When module is freed(kprobes hooks module_notifier to get this
event), kprobes which probe the functions in that module are set to "Gone"
flag to the flags member. These "Gone" probes are never be enabled.
Users can check the GONE flag through debugfs.
This also removes mod_refcounted, because we couldn't free a module if
kprobe incremented the refcount of that module.
[akpm@linux-foundation.org: document some locking]
[mhiramat@redhat.com: bugfix: pass aggr_kprobe to arch_remove_kprobe]
[mhiramat@redhat.com: bugfix: release old_p's insn_slot before error return]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add __kprobes to kprobes internal functions for protecting from probing by
kprobes itself.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add kprobe_insn_mutex for protecting kprobe_insn_pages hlist, and remove
kprobe_mutex from architecture dependent code.
This allows us to call arch_remove_kprobe() (and free_insn_slot) while
holding kprobe_mutex.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This series of patches allows kprobes to probe module's __init and __exit
functions. This means, you can probe driver initialization and
terminating.
Currently, kprobes can't probe __init function because these functions are
freed after module initialization. And it also can't probe module __exit
functions because kprobe increments reference count of target module and
user can't unload it. this means __exit functions never be called unless
removing probes from the module.
To solve both cases, this series of patches introduces GONE flag and sets
it when the target code is freed(for this purpose, kprobes hooks
MODULE_STATE_* events). This also removes refcount incrementing for
allowing user to unload target module. Users can check which probes are
GONE by debugfs interface. For taking timing of freeing module's .init
text, these also include a patch which adds module's notifier of
MODULE_STATE_LIVE event.
This patch:
Add within_module_core() and within_module_init() for checking whether an
address is in the module .init.text section or .text section, and replace
within() local inline functions in kernel/module.c with them.
kprobes uses these functions to check where the kprobe is inserted.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Call kprobe_target indirectly. This prevents gcc to unroll a noinline
function in caller function.
I ported patches which had been discussed on
http://sources.redhat.com/bugzilla/show_bug.cgi?id=3542
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When someone called register_*probe() from kernel-core code(not from
module) and that probes a kernel module, users can remove the probed
module because kprobe doesn't increment reference counter of the module.
(on the other hand, if the kernel-module calls register_*probe, kprobe
increments refcount of the probed module.)
Currently, we have no register_*probe() calling from kernel-core(except
smoke-test, but the smoke-test doesn't probe module), so there is no real
bugs. But the logic is wrong(or not fair) and it can causes a problem
when someone might want to probe module from kernel.
After this patch is applied, even if someone put register_*probe() call in
the kernel-core code, it increments the reference counter of the probed
module, and it prevents user to remove the module until stopping probing
it.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, kernel/profile.c include <asm/ptrace.h> twice. It can be
removed.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At the moment, the times() system call will appear to fail for a period
shortly after boot, while the value it want to return is between -4095 and
-1. The same thing will also happen for the time() system call on 32-bit
platforms some time in 2106 or so.
On some platforms, such as x86, this is unavoidable because of the system
call ABI, but other platforms such as powerpc have a separate error
indication from the return value, so system calls can in fact return small
negative values without indicating an error. On those platforms,
force_successful_syscall_return() provides a way to indicate that the
system call return value should not be treated as an error even if it is
in the range which would normally be taken as a negative error number.
This adds a force_successful_syscall_return() call to the time() and
times() system calls plus their 32-bit compat versions, so that they don't
erroneously indicate an error on those platforms whose system call ABI has
a separate error indication. This will not affect anything on other
platforms.
Joakim Tjernlund added the fix for time() and the compat versions of
time() and times(), after I did the fix for times().
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
... because we do want repeated same-oops to be seen by automated
tools like kerneloops.org
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check CLONE_SIGHAND only is enough, because combination of CLONE_THREAD and
CLONE_SIGHAND is already done in copy_process().
Impact: cleanup, no functionality changed
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
xacct_add_tsk() relies on do_exit()->update_hiwater_xxx() and uses
mm->hiwater_xxx directly, this leads to 2 problems:
- taskstats_user_cmd() can call fill_pid()->xacct_add_tsk() at any
moment before the task exits, so we should check the current values of
rss/vm anyway.
- do_exit()->update_hiwater_xxx() calls are racy. An exiting thread can
be preempted right before mm->hiwater_xxx = new_val, and another thread
can use A_LOT of memory and exit in between. When the first thread
resumes it can be the last thread in the thread group, in that case we
report the wrong hiwater_xxx values which do not take A_LOT into
account.
Introduce get_mm_hiwater_rss() and get_mm_hiwater_vm() helpers and change
xacct_add_tsk() to use them. The first helper will also be used by
rusage->ru_maxrss accounting.
Kill do_exit()->update_hiwater_xxx() calls. Unless we are going to
decrease rss/vm there is no point to update mm->hiwater_xxx, and nobody
can look at this mm_struct when exit_mmap() actually unmaps the memory.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This change introduces two new sysctls to /proc/sys/vm:
dirty_background_bytes and dirty_bytes.
dirty_background_bytes is the counterpart to dirty_background_ratio and
dirty_bytes is the counterpart to dirty_ratio.
With growing memory capacities of individual machines, it's no longer
sufficient to specify dirty thresholds as a percentage of the amount of
dirtyable memory over the entire system.
dirty_background_bytes and dirty_bytes specify quantities of memory, in
bytes, that represent the dirty limits for the entire system. If either
of these values is set, its value represents the amount of dirty memory
that is needed to commence either background or direct writeback.
When a `bytes' or `ratio' file is written, its counterpart becomes a
function of the written value. For example, if dirty_bytes is written to
be 8096, 8K of memory is required to commence direct writeback.
dirty_ratio is then functionally equivalent to 8K / the amount of
dirtyable memory:
dirtyable_memory = free pages + mapped pages + file cache
dirty_background_bytes = dirty_background_ratio * dirtyable_memory
-or-
dirty_background_ratio = dirty_background_bytes / dirtyable_memory
AND
dirty_bytes = dirty_ratio * dirtyable_memory
-or-
dirty_ratio = dirty_bytes / dirtyable_memory
Only one of dirty_background_bytes and dirty_background_ratio may be
specified at a time, and only one of dirty_bytes and dirty_ratio may be
specified. When one sysctl is written, the other appears as 0 when read.
The `bytes' files operate on a page size granularity since dirty limits
are compared with ZVC values, which are in page units.
Prior to this change, the minimum dirty_ratio was 5 as implemented by
get_dirty_limits() although /proc/sys/vm/dirty_ratio would show any user
written value between 0 and 100. This restriction is maintained, but
dirty_bytes has a lower limit of only one page.
Also prior to this change, the dirty_background_ratio could not equal or
exceed dirty_ratio. This restriction is maintained in addition to
restricting dirty_background_bytes. If either background threshold equals
or exceeds that of the dirty threshold, it is implicitly set to half the
dirty threshold.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cgroup_mm_owner_callbacks() was brought in to support the memrlimit
controller, but sneaked into mainline ahead of it. That controller has
now been shelved, and the mm_owner_changed() args were inadequate for it
anyway (they needed an mm pointer instead of a task pointer).
Remove the dead code, and restore mm_update_next_owner() locking to how it
was before: taking mmap_sem there does nothing for memcontrol.c, now the
only user of mm->owner.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When cpusets are enabled, it's necessary to print the triggering task's
set of allowable nodes so the subsequently printed meminfo can be
interpreted correctly.
We also print the task's cpuset name for informational purposes.
[rientjes@google.com: task lock current before dereferencing cpuset]
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a regression in cap_capable() due to:
commit 3b11a1dece
Author: David Howells <dhowells@redhat.com>
Date: Fri Nov 14 10:39:26 2008 +1100
CRED: Differentiate objective and effective subjective credentials on a task
The problem is that the above patch allows a process to have two sets of
credentials, and for the most part uses the subjective credentials when
accessing current's creds.
There is, however, one exception: cap_capable(), and thus capable(), uses the
real/objective credentials of the target task, whether or not it is the current
task.
Ordinarily this doesn't matter, since usually the two cred pointers in current
point to the same set of creds. However, sys_faccessat() makes use of this
facility to override the credentials of the calling process to make its test,
without affecting the creds as seen from other processes.
One of the things sys_faccessat() does is to make an adjustment to the
effective capabilities mask, which cap_capable(), as it stands, then ignores.
The affected capability check is in generic_permission():
if (!(mask & MAY_EXEC) || execute_ok(inode))
if (capable(CAP_DAC_OVERRIDE))
return 0;
This change passes the set of credentials to be tested down into the commoncap
and SELinux code. The security functions called by capable() and
has_capability() select the appropriate set of credentials from the process
being checked.
This can be tested by compiling the following program from the XFS testsuite:
/*
* t_access_root.c - trivial test program to show permission bug.
*
* Written by Michael Kerrisk - copyright ownership not pursued.
* Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html
*/
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#define UID 500
#define GID 100
#define PERM 0
#define TESTPATH "/tmp/t_access"
static void
errExit(char *msg)
{
perror(msg);
exit(EXIT_FAILURE);
} /* errExit */
static void
accessTest(char *file, int mask, char *mstr)
{
printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask));
} /* accessTest */
int
main(int argc, char *argv[])
{
int fd, perm, uid, gid;
char *testpath;
char cmd[PATH_MAX + 20];
testpath = (argc > 1) ? argv[1] : TESTPATH;
perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM;
uid = (argc > 3) ? atoi(argv[3]) : UID;
gid = (argc > 4) ? atoi(argv[4]) : GID;
unlink(testpath);
fd = open(testpath, O_RDWR | O_CREAT, 0);
if (fd == -1) errExit("open");
if (fchown(fd, uid, gid) == -1) errExit("fchown");
if (fchmod(fd, perm) == -1) errExit("fchmod");
close(fd);
snprintf(cmd, sizeof(cmd), "ls -l %s", testpath);
system(cmd);
if (seteuid(uid) == -1) errExit("seteuid");
accessTest(testpath, 0, "0");
accessTest(testpath, R_OK, "R_OK");
accessTest(testpath, W_OK, "W_OK");
accessTest(testpath, X_OK, "X_OK");
accessTest(testpath, R_OK | W_OK, "R_OK | W_OK");
accessTest(testpath, R_OK | X_OK, "R_OK | X_OK");
accessTest(testpath, W_OK | X_OK, "W_OK | X_OK");
accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK");
exit(EXIT_SUCCESS);
} /* main */
This can be run against an Ext3 filesystem as well as against an XFS
filesystem. If successful, it will show:
[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx
access(/tmp/xxx, 0) returns 0
access(/tmp/xxx, R_OK) returns 0
access(/tmp/xxx, W_OK) returns 0
access(/tmp/xxx, X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK) returns 0
access(/tmp/xxx, R_OK | X_OK) returns -1
access(/tmp/xxx, W_OK | X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1
If unsuccessful, it will show:
[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx
access(/tmp/xxx, 0) returns 0
access(/tmp/xxx, R_OK) returns -1
access(/tmp/xxx, W_OK) returns -1
access(/tmp/xxx, X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK) returns -1
access(/tmp/xxx, R_OK | X_OK) returns -1
access(/tmp/xxx, W_OK | X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1
I've also tested the fix with the SELinux and syscalls LTP testsuites.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Access to uevent_seqnum and uevent_helper does not need to
depend on CONFIG_NET, so remove it.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove bogus indentation of new_text_line declaration introduced in
commit ac60ad741.
Acked-by: Nick Andrew <nick@nick-andrew.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
init_rootdomain() calls alloc_bootmem_cpumask_var() at system boot,
so does cpupri_init().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's not the responsibility of init_rootdomain() to free root_domain
allocated by alloc_rootdomain().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
module: convert to stop_machine_create/destroy.
stop_machine: introduce stop_machine_create/destroy.
parisc: fix module loading failure of large kernel modules
module: fix module loading failure of large kernel modules for parisc
module: fix warning of unused function when !CONFIG_PROC_FS
kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms.
remove CONFIG_KMOD
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
inotify: fix type errors in interfaces
fix breakage in reiserfs_new_inode()
fix the treatment of jfs special inodes
vfs: remove duplicate code in get_fs_type()
add a vfs_fsync helper
sys_execve and sys_uselib do not call into fsnotify
zero i_uid/i_gid on inode allocation
inode->i_op is never NULL
ntfs: don't NULL i_op
isofs check for NULL ->i_op in root directory is dead code
affs: do not zero ->i_op
kill suid bit only for regular files
vfs: lseek(fd, 0, SEEK_CUR) race condition
... and don't bother in callers. Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.
i_mode is not worth the effort; it has no common default value.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- Make arch_reinit_sched_domains() static. It was exported to be used in
s390, but now rebuild_sched_domains() is used instead.
- Make it return void.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
The only caller is cpu_dev_init() which is marked as __init.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Clean up the comments
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix rare runtime deadlock
There are a few sites that do:
spin_lock_irq(&foo)
hrtimer_start(&bar)
__run_hrtimer(&bar)
func()
spin_lock(&foo)
which obviously deadlocks. In order to avoid this, never call __run_hrtimer()
from hrtimer_start*() context, but instead defer this to softirq context.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
No need for a smp function call, which is likely to run on the same
CPU anyway. We can just call hrtimers_peek_ahead() in the interrupts
disabled section of migrate_hrtimers().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
kernel/hrtimer.c: In function 'hrtimer_cpu_notify':
kernel/hrtimer.c:1574: warning: unused variable 'dcpu'
Introduced by commit 37810659ea
("hrtimer: removing all ur callback modes, fix hotplug") from the
timers. dcpu is only used if CONFIG_HOTPLUG_CPU is set.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Provide a peek ahead function that assumes irqs disabled, allows for micro
optimizations.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix an rcutorture bug that prevents the shutdown notifier from ever
actually having any effect, due to the fact that kthreads ignore all
signals.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Expand macro into two files.
The synchronize_rcu_xxx macro is quite ugly and it's only used by two
callers, so expand it instead. This makes this code easier to change.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix kernel warnings [and potential crash] during suspend+resume
Kudos to both Dhaval Giani and Jens Axboe for finding a bug in treercu
that causes warnings after suspend-resume cycles in Dhaval's case and
during stress tests in Jens's case. It would also probably cause failures
if heavily stressed. The solution, ironically enough, is to revert to
rcupreempt's code for initializing the dynticks state. And the patch
even results in smaller code -- so what was I thinking???
This is 2.6.29 material, given that people really do suspend and resume
Linux these days. ;-)
Reported-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Reported-by: Jens Axboe <jens.axboe@oracle.com>
Tested-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Tested-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix delays during bootup
Kudos to Andi Kleen for finding a grace-period-latency problem! The
problem was that the special-case code for small machines never updated
the ->signaled field to indicate that grace-period initialization had
completed, which prevented force_quiescent_state() from ever expediting
grace periods. This problem resulted in grace periods extending for more
than 20 seconds. Not subtle. I introduced this bug during my inspection
process when I fixed a race between grace-period initialization and
force_quiescent_state() execution.
The following patch properly updates the ->signaled field for the
"small"-system case (no more than 32 CPUs for 32-bit kernels and no more
than 64 CPUs for 64-bit kernels).
Reported-by: Andi Kleen <andi@firstfloor.org>
Tested-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'audit.b61' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
audit: validate comparison operations, store them in sane form
clean up audit_rule_{add,del} a bit
make sure that filterkey of task,always rules is reported
audit rules ordering, part 2
fixing audit rule ordering mess, part 1
audit_update_lsm_rules() misses the audit_inode_hash[] ones
sanitize audit_log_capset()
sanitize audit_fd_pair()
sanitize audit_mq_open()
sanitize AUDIT_MQ_SENDRECV
sanitize audit_mq_notify()
sanitize audit_mq_getsetattr()
sanitize audit_ipc_set_perm()
sanitize audit_ipc_obj()
sanitize audit_socketcall
don't reallocate buffer in every audit_sockaddr()
Fix a regression in cap_capable() due to:
commit 5ff7711e635b32f0a1e558227d030c7e45b4a465
Author: David Howells <dhowells@redhat.com>
Date: Wed Dec 31 02:52:28 2008 +0000
CRED: Differentiate objective and effective subjective credentials on a task
The problem is that the above patch allows a process to have two sets of
credentials, and for the most part uses the subjective credentials when
accessing current's creds.
There is, however, one exception: cap_capable(), and thus capable(), uses the
real/objective credentials of the target task, whether or not it is the current
task.
Ordinarily this doesn't matter, since usually the two cred pointers in current
point to the same set of creds. However, sys_faccessat() makes use of this
facility to override the credentials of the calling process to make its test,
without affecting the creds as seen from other processes.
One of the things sys_faccessat() does is to make an adjustment to the
effective capabilities mask, which cap_capable(), as it stands, then ignores.
The affected capability check is in generic_permission():
if (!(mask & MAY_EXEC) || execute_ok(inode))
if (capable(CAP_DAC_OVERRIDE))
return 0;
This change splits capable() from has_capability() down into the commoncap and
SELinux code. The capable() security op now only deals with the current
process, and uses the current process's subjective creds. A new security op -
task_capable() - is introduced that can check any task's objective creds.
strictly the capable() security op is superfluous with the presence of the
task_capable() op, however it should be faster to call the capable() op since
two fewer arguments need be passed down through the various layers.
This can be tested by compiling the following program from the XFS testsuite:
/*
* t_access_root.c - trivial test program to show permission bug.
*
* Written by Michael Kerrisk - copyright ownership not pursued.
* Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html
*/
#include <limits.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/stat.h>
#define UID 500
#define GID 100
#define PERM 0
#define TESTPATH "/tmp/t_access"
static void
errExit(char *msg)
{
perror(msg);
exit(EXIT_FAILURE);
} /* errExit */
static void
accessTest(char *file, int mask, char *mstr)
{
printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask));
} /* accessTest */
int
main(int argc, char *argv[])
{
int fd, perm, uid, gid;
char *testpath;
char cmd[PATH_MAX + 20];
testpath = (argc > 1) ? argv[1] : TESTPATH;
perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM;
uid = (argc > 3) ? atoi(argv[3]) : UID;
gid = (argc > 4) ? atoi(argv[4]) : GID;
unlink(testpath);
fd = open(testpath, O_RDWR | O_CREAT, 0);
if (fd == -1) errExit("open");
if (fchown(fd, uid, gid) == -1) errExit("fchown");
if (fchmod(fd, perm) == -1) errExit("fchmod");
close(fd);
snprintf(cmd, sizeof(cmd), "ls -l %s", testpath);
system(cmd);
if (seteuid(uid) == -1) errExit("seteuid");
accessTest(testpath, 0, "0");
accessTest(testpath, R_OK, "R_OK");
accessTest(testpath, W_OK, "W_OK");
accessTest(testpath, X_OK, "X_OK");
accessTest(testpath, R_OK | W_OK, "R_OK | W_OK");
accessTest(testpath, R_OK | X_OK, "R_OK | X_OK");
accessTest(testpath, W_OK | X_OK, "W_OK | X_OK");
accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK");
exit(EXIT_SUCCESS);
} /* main */
This can be run against an Ext3 filesystem as well as against an XFS
filesystem. If successful, it will show:
[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx
access(/tmp/xxx, 0) returns 0
access(/tmp/xxx, R_OK) returns 0
access(/tmp/xxx, W_OK) returns 0
access(/tmp/xxx, X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK) returns 0
access(/tmp/xxx, R_OK | X_OK) returns -1
access(/tmp/xxx, W_OK | X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1
If unsuccessful, it will show:
[root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043
---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx
access(/tmp/xxx, 0) returns 0
access(/tmp/xxx, R_OK) returns -1
access(/tmp/xxx, W_OK) returns -1
access(/tmp/xxx, X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK) returns -1
access(/tmp/xxx, R_OK | X_OK) returns -1
access(/tmp/xxx, W_OK | X_OK) returns -1
access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1
I've also tested the fix with the SELinux and syscalls LTP testsuites.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
The module code relies on a non-failing stop_machine call. So we create
the kstop threads in advance and with that make sure the call won't fail.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Introduce stop_machine_create/destroy. With this interface subsystems
that need a non-failing stop_machine environment can create the
stop_machine machine threads before actually calling stop_machine.
When the threads aren't needed anymore they can be killed with
stop_machine_destroy again.
When stop_machine gets called and the threads aren't present they
will be created and destroyed automatically. This restores the old
behaviour of stop_machine.
This patch also converts cpu hotplug to the new interface since it
is special: cpu_down calls __stop_machine instead of stop_machine.
However the kstop threads will only be created when stop_machine
gets called.
Changing the code so that the threads would be created automatically
on __stop_machine is currently not possible: when __stop_machine gets
called we hold cpu_add_remove_lock, which is the same lock that
create_rt_workqueue would take. So the workqueue needs to be created
before the cpu hotplug code locks cpu_add_remove_lock.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When creating the final layout of a kernel module in memory, allow the
module loader to reserve some additional memory in front of a given section.
This is currently only needed for the parisc port which needs to put the
stub entries there to fulfill the 17/22bit PCREL relocations with large
kernel modules like xfs.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (renamed fn)
Fix this warning:
kernel/module.c:824: warning: ‘print_unload_info’ defined but not used
print_unload_info() just was used when CONFIG_PROC_FS was defined.
This patch mark print_unload_info() inline to solve the problem.
Signed-off-by: Jianjun Kong <jianjun@zeuux.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: Ingo Molnar <mingo@elte.hu>
CC: Américo Wang <xiyou.wangcong@gmail.com>
When there are two symbols in a module with the same name, one of which is
exported, both will be marked as exported in /proc/kallsyms. There aren't
any instances of this in the current kernel, but it is easy to construct a
simple module with two compilation units that exhibits the problem.
$ objdump -j .text -t testmod.ko | grep foo
00000000 l F .text 00000032 foo
00000080 g F .text 00000001 foo
$ sudo insmod testmod.ko
$ grep "T foo" /proc/kallsyms
c28e8000 T foo [testmod]
c28e8080 T foo [testmod]
Fix this by comparing the symbol values once we've found the exported
symbol table entry matching the symbol name. Tested using Ksplice:
$ ksplice-create --patch=this_commit.patch --id=bar .
$ sudo ksplice-apply ksplice-bar.tar.gz
Done!
$ grep "T foo" /proc/kallsyms
c28e8080 T foo [testmod]
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The race is calling cgroup_clone() while umounting the ns cgroup subsys,
and thus cgroup_clone() might access invalid cgroup_fs, or kill_sb() is
called after cgroup_clone() created a new dir in it.
The BUG I triggered is BUG_ON(root->number_of_cgroups != 1);
------------[ cut here ]------------
kernel BUG at kernel/cgroup.c:1093!
invalid opcode: 0000 [#1] SMP
...
Process umount (pid: 5177, ti=e411e000 task=e40c4670 task.ti=e411e000)
...
Call Trace:
[<c0493df7>] ? deactivate_super+0x3f/0x51
[<c04a3600>] ? mntput_no_expire+0xb3/0xdd
[<c04a3ab2>] ? sys_umount+0x265/0x2ac
[<c04a3b06>] ? sys_oldumount+0xd/0xf
[<c0403911>] ? sysenter_do_call+0x12/0x31
...
EIP: [<c0456e76>] cgroup_kill_sb+0x23/0xe0 SS:ESP 0068:e411ef2c
---[ end trace c766c1be3bf944ac ]---
Cc: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't store the field->op in the messy (and very inconvenient for e.g.
audit_comparator()) form; translate to dense set of values and do full
validation of userland-submitted value while we are at it.
->audit_init_rule() and ->audit_match_rule() get new values now; in-tree
instances updated.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix the actual rule listing; add per-type lists _not_ used for matching,
with all exit,... sitting on one such list. Simplifies "do something
for all rules" logics, while we are at it...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Problem: ordering between the rules on exit chain is currently lost;
all watch and inode rules are listed after everything else _and_
exit,never on one kind doesn't stop exit,always on another from
being matched.
Solution: assign priorities to rules, keep track of the current
highest-priority matching rule and its result (always/never).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't bother with allocations
* don't do double copy_from_user()
* don't duplicate parts of check for audit_dummy_context()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* logging the original value of *msg_prio in mq_timedreceive(2)
is insane - the argument is write-only (i.e. syscall always
ignores the original value and only overwrites it).
* merge __audit_mq_timed{send,receive}
* don't do copy_from_user() twice
* don't mess with allocations in auditsc part
* ... and don't bother checking !audit_enabled and !context in there -
we'd already checked for audit_dummy_context().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't copy_from_user() twice
* don't bother with allocations
* don't duplicate parts of audit_dummy_context()
* make it return void
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Lai Jiangshan