Commit Graph

8427 Commits

Author SHA1 Message Date
Linus Torvalds
3e72b810e3 Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  mutex: Fix missing conditions to build mutex_spin_on_owner()
  mutex: Better control mutex adaptive spinning config
  locking, task_struct: Reduce size on TRACE_IRQFLAGS and 64bit
  locking: Use __[SPIN|RW]_LOCK_UNLOCKED in [spin|rw]_lock_init()
  locking: Remove unused prototype
  locking: Reduce ifdefs in kernel/spinlock.c
  locking: Make inlining decision Kconfig based
2009-12-05 09:49:59 -08:00
Linus Torvalds
9b269d4034 Merge branch 'core-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  generic-ipi: Add smp_call_function_any()
  generic-ipi: Fix misleading smp_call_function*() description
2009-12-05 09:49:46 -08:00
Frederic Weisbecker
c08f782985 mutex: Fix missing conditions to build mutex_spin_on_owner()
We don't need to build mutex_spin_on_owner() if we have
CONFIG_DEBUG_MUTEXES or CONFIG_HAVE_DEFAULT_NO_SPIN_MUTEXES as
it won't be used under such configs.

Use CONFIG_MUTEX_SPIN_ON_OWNER as it gathers all the necessary
checks before building it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1259783357-8542-2-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
2009-12-03 11:50:11 +01:00
Frederic Weisbecker
c02260277e mutex: Better control mutex adaptive spinning config
Introduce CONFIG_MUTEX_SPIN_ON_OWNER so that we can centralize
in a single place the conditions that determine its definition
and use.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1259783357-8542-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
2009-12-03 11:50:11 +01:00
James Morris
c84d6efd36 Merge branch 'master' into next 2009-12-03 12:03:40 +05:30
Helge Deller
35dead4235 modules: don't export section names of empty sections via sysfs
On the parisc architecture we face for each and every loaded kernel module
this kernel "badness warning":
  sysfs: cannot create duplicate filename '/module/ac97_bus/sections/.text'
  Badness at fs/sysfs/dir.c:487

Reason for that is, that on parisc all kernel modules do have multiple
.text sections due to the usage of the -ffunction-sections compiler flag
which is needed to reach all jump targets on this platform.

An objdump on such a kernel module gives:
Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .note.gnu.build-id 00000024  00000000  00000000  00000034  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  1 .text         00000000  00000000  00000000  00000058  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 .text.ac97_bus_match 0000001c  00000000  00000000  00000058  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  3 .text         00000000  00000000  00000000  000000d4  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
...
Since the .text sections are empty (size of 0 bytes) and won't be
loaded by the kernel module loader anyway, I don't see a reason
why such sections need to be listed under
/sys/module/<module_name>/sections/<section_name> either.

The attached patch does solve this issue by not exporting section
names which are empty.

This fixes bugzilla http://bugzilla.kernel.org/show_bug.cgi?id=14703

Signed-off-by: Helge Deller <deller@gmx.de>
CC: rusty@rustcorp.com.au
CC: akpm@linux-foundation.org
CC: James.Bottomley@HansenPartnership.com
CC: roland@redhat.com
CC: dave@hiauly1.hia.nrc.ca
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-02 15:38:25 -08:00
David Howells
f13a48bd79 SLOW_WORK: Move slow_work's proc file to debugfs
Move slow_work's debugging proc file to debugfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Requested-and-acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-01 08:20:31 -08:00
David Howells
fa1dae4906 SLOW_WORK: Fix the CONFIG_MODULES=n case
Commits 3d7a641 ("SLOW_WORK: Wait for outstanding work items belonging to a
module to clear") introduced some code to make sure that all of a module's
slow-work items were complete before that module was removed, and commit
3bde31a ("SLOW_WORK: Allow a requeueable work item to sleep till the thread is
needed") further extended that, breaking it in the process if CONFIG_MODULES=n:

    CC      kernel/slow-work.o
  kernel/slow-work.c: In function 'slow_work_execute':
  kernel/slow-work.c:313: error: 'slow_work_thread_processing' undeclared (first use in this function)
  kernel/slow-work.c:313: error: (Each undeclared identifier is reported only once
  kernel/slow-work.c:313: error: for each function it appears in.)
  kernel/slow-work.c: In function 'slow_work_wait_for_items':
  kernel/slow-work.c:950: error: 'slow_work_unreg_sync_lock' undeclared (first use in this function)
  kernel/slow-work.c:951: error: 'slow_work_unreg_wq' undeclared (first use in this function)
  kernel/slow-work.c:961: error: 'slow_work_unreg_work_item' undeclared (first use in this function)
  kernel/slow-work.c:974: error: 'slow_work_unreg_module' undeclared (first use in this function)
  kernel/slow-work.c:977: error: 'slow_work_thread_processing' undeclared (first use in this function)
  make[1]: *** [kernel/slow-work.o] Error 1

Fix this by:

 (1) Extracting the bits of slow_work_execute() that are contingent on
     CONFIG_MODULES, and the bits that should be, into inline functions and
     placing them into the #ifdef'd section that defines the relevant variables
     and adding stubs for moduleless kernels.  This allows the removal of some
     #ifdefs.

 (2) #ifdef'ing out the contents of slow_work_wait_for_items() in moduleless
     kernels.

The four functions related to handling module unloading synchronisation (and
their associated variables) could be offloaded into a separate .c file, but
each function is only used once and three of them are tiny, so doing so would
prevent them from being inlined.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-01 07:35:11 -08:00
Serge E. Hallyn
b3a222e52e remove CONFIG_SECURITY_FILE_CAPABILITIES compile option
As far as I know, all distros currently ship kernels with default
CONFIG_SECURITY_FILE_CAPABILITIES=y.  Since having the option on
leaves a 'no_file_caps' option to boot without file capabilities,
the main reason to keep the option is that turning it off saves
you (on my s390x partition) 5k.  In particular, vmlinux sizes
came to:

without patch fscaps=n:		 	53598392
without patch fscaps=y:		 	53603406
with this patch applied:		53603342

with the security-next tree.

Against this we must weigh the fact that there is no simple way for
userspace to figure out whether file capabilities are supported,
while things like per-process securebits, capability bounding
sets, and adding bits to pI if CAP_SETPCAP is in pE are not supported
with SECURITY_FILE_CAPABILITIES=n, leaving a bit of a problem for
applications wanting to know whether they can use them and/or why
something failed.

It also adds another subtly different set of semantics which we must
maintain at the risk of severe security regressions.

So this patch removes the SECURITY_FILE_CAPABILITIES compile
option.  It drops the kernel size by about 50k over the stock
SECURITY_FILE_CAPABILITIES=y kernel, by removing the
cap_limit_ptraced_target() function.

Changelog:
	Nov 20: remove cap_limit_ptraced_target() as it's logic
		was ifndef'ed.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Andrew G. Morgan" <morgan@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
2009-11-24 15:06:47 +11:00
Andrew G. Morgan
c4a5af54c8 Silence the existing API for capability version compatibility check.
When libcap, or other libraries attempt to confirm/determine the supported
capability version magic, they generally supply a NULL dataptr to capget().

In this case, while returning the supported/preferred magic (via a
modified header content), the return code of this system call may be 0,
-EINVAL, or -EFAULT.

No libcap code depends on the previous -EINVAL etc. return code, and
all of the above three return codes can accompany a valid (successful)
attempt to determine the requested magic value.

This patch cleans up the system call to return 0, if the call is
successfully being used to determine the supported/preferred capability
magic value.

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-11-24 08:53:29 +11:00
David Howells
3bde31a4ac SLOW_WORK: Allow a requeueable work item to sleep till the thread is needed
Add a function to allow a requeueable work item to sleep till the thread
processing it is needed by the slow-work facility to perform other work.

Sometimes a work item can't progress immediately, but must wait for the
completion of another work item that's currently being processed by another
slow-work thread.

In some circumstances, the waiting item could instead - theoretically - put
itself back on the queue and yield its thread back to the slow-work facility,
thus waiting till it gets processing time again before attempting to progress.
This would allow other work items processing time on that thread.

However, this only works if there is something on the queue for it to queue
behind - otherwise it will just get a thread again immediately, and will end
up cycling between the queue and the thread, eating up valuable CPU time.

So, slow_work_sleep_till_thread_needed() is provided such that an item can put
itself on a wait queue that will wake it up when the event it is actually
interested in occurs, then call this function in lieu of calling schedule().

This function will then sleep until either the item's event occurs or another
work item appears on the queue.  If another work item is queued, but the
item's event hasn't occurred, then the work item should requeue itself and
yield the thread back to the slow-work facility by returning.

This can be used by CacheFiles for an object that is being created on one
thread to wait for an object being deleted on another thread where there is
nothing on the queue for the creation to go and wait behind.  As soon as an
item appears on the queue that could be given thread time instead, CacheFiles
can stick the creating object back on the queue and return to the slow-work
facility - assuming the object deletion didn't also complete.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:10:57 +00:00
David Howells
8fba10a42d SLOW_WORK: Allow the work items to be viewed through a /proc file
Allow the executing and queued work items to be viewed through a /proc file
for debugging purposes.  The contents look something like the following:

    THR PID   ITEM ADDR        FL MARK  DESC
    === ===== ================ == ===== ==========
      0  3005 ffff880023f52348  a 952ms FSC: OBJ17d3: LOOK
      1  3006 ffff880024e33668  2 160ms FSC: OBJ17e5 OP60d3b: Write1/Store fl=2
      2  3165 ffff8800296dd180  a 424ms FSC: OBJ17e4: LOOK
      3  4089 ffff8800262c8d78  a 212ms FSC: OBJ17ea: CRTN
      4  4090 ffff88002792bed8  2 388ms FSC: OBJ17e8 OP60d36: Write1/Store fl=2
      5  4092 ffff88002a0ef308  2 388ms FSC: OBJ17e7 OP60d2e: Write1/Store fl=2
      6  4094 ffff88002abaf4b8  2 132ms FSC: OBJ17e2 OP60d4e: Write1/Store fl=2
      7  4095 ffff88002bb188e0  a 388ms FSC: OBJ17e9: CRTN
    vsq     - ffff880023d99668  1 308ms FSC: OBJ17e0 OP60f91: Write1/EnQ fl=2
    vsq     - ffff8800295d1740  1 212ms FSC: OBJ16be OP4d4b6: Write1/EnQ fl=2
    vsq     - ffff880025ba3308  1 160ms FSC: OBJ179a OP58dec: Write1/EnQ fl=2
    vsq     - ffff880024ec83e0  1 160ms FSC: OBJ17ae OP599f2: Write1/EnQ fl=2
    vsq     - ffff880026618e00  1 160ms FSC: OBJ17e6 OP60d33: Write1/EnQ fl=2
    vsq     - ffff880025a2a4b8  1 132ms FSC: OBJ16a2 OP4d583: Write1/EnQ fl=2
    vsq     - ffff880023cbe6d8  9 212ms FSC: OBJ17eb: LOOK
    vsq     - ffff880024d37590  9 212ms FSC: OBJ17ec: LOOK
    vsq     - ffff880027746cb0  9 212ms FSC: OBJ17ed: LOOK
    vsq     - ffff880024d37ae8  9 212ms FSC: OBJ17ee: LOOK
    vsq     - ffff880024d37cb0  9 212ms FSC: OBJ17ef: LOOK
    vsq     - ffff880025036550  9 212ms FSC: OBJ17f0: LOOK
    vsq     - ffff8800250368e0  9 212ms FSC: OBJ17f1: LOOK
    vsq     - ffff880025036aa8  9 212ms FSC: OBJ17f2: LOOK

In the 'THR' column, executing items show the thread they're occupying and
queued threads indicate which queue they're on.  'PID' shows the process ID of
a slow-work thread that's executing something.  'FL' shows the work item flags.
'MARK' indicates how long since an item was queued or began executing.  Lastly,
the 'DESC' column permits the owner of an item to give some information.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:10:51 +00:00
Jens Axboe
6b8268b17a SLOW_WORK: Add delayed_slow_work support
This adds support for starting slow work with a delay, similar
to the functionality we have for workqueues.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:10:47 +00:00
Jens Axboe
0160950297 SLOW_WORK: Add support for cancellation of slow work
Add support for cancellation of queued slow work and delayed slow work items.
The cancellation functions will wait for items that are pending or undergoing
execution to be discarded by the slow work facility.

Attempting to enqueue work that is in the process of being cancelled will
result in ECANCELED.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:10:43 +00:00
Jens Axboe
4d8bb2cbcc SLOW_WORK: Make slow_work_ops ->get_ref/->put_ref optional
Make the ability for the slow-work facility to take references on a work item
optional as not everyone requires this.

Even the internal slow-work stubs them out, so those can be got rid of too.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:10:39 +00:00
David Howells
3d7a641e54 SLOW_WORK: Wait for outstanding work items belonging to a module to clear
Wait for outstanding slow work items belonging to a module to clear when
unregistering that module as a user of the facility.  This prevents the put_ref
code of a work item from being taken away before it returns.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:10:23 +00:00
Rusty Russell
2ea6dec4a2 generic-ipi: Add smp_call_function_any()
Andrew points out that acpi-cpufreq uses cpumask_any, when it really
would prefer to use the same CPU if possible (to avoid an IPI).  In
general, this seems a good idea to offer.

[ tglx: Documented selection preference and Inlined the UP case to
  	avoid the copy of smp_call_function_single() and the extra
  	EXPORT ]

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-11-18 14:52:25 +01:00
Tejun Heo
9398180097 workqueue: fix race condition in schedule_on_each_cpu()
Commit 65a6446434 ("HWPOISON: Allow
schedule_on_each_cpu() from keventd") which allows schedule_on_each_cpu()
to be called from keventd added a race condition.  schedule_on_each_cpu()
may race with cpu hotplug and end up executing the function twice on a
cpu.

Fix it by moving direct execution into the section protected with
get/put_online_cpus().  While at it, update code such that direct
execution is done after works have been scheduled for all other cpus and
drop unnecessary cpu != orig test from flush loop.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-17 17:40:33 -08:00
Thomas Gleixner
8e13c7b772 locking: Reduce ifdefs in kernel/spinlock.c
With the Kconfig based inline decisions we can remove extra ifdefs in
kernel/spinlock.c by creating the complex lockbreak functions as
inlines which are inserted into the non inlined lock functions.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091109151428.548614772@linutronix.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-11-13 20:53:28 +01:00
Thomas Gleixner
6beb000923 locking: Make inlining decision Kconfig based
commit 892a7c67 (locking: Allow arch-inlined spinlocks) implements the
selection of which lock functions are inlined based on defines in
arch/.../spinlock.h: #define __always_inline__LOCK_FUNCTION

Despite of the name __always_inline__* the lock functions can be built
out of line depending on config options. Also if the arch does not set
some inline defines the generic code might set them; again depending on
config options.

This makes it unnecessary hard to figure out when and which lock
functions are inlined. Aside of that it makes it way harder and
messier for -rt to manipulate the lock functions.

Convert the inlining decision to CONFIG switches. Each lock function
is inlined depending on CONFIG_INLINE_*. The configs implement the
existing dependencies. The architecture code can select ARCH_INLINE_*
to signal that it wants the corresponding lock function inlined.
ARCH_INLINE_* is necessary as Kconfig ignores "depends on"
restrictions when a config element is selected.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091109151428.504477141@linutronix.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-11-13 20:53:28 +01:00
Linus Torvalds
961767b75d Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  highmem: Fix debug_kmap_atomic() to also handle KM_IRQ_PTE, KM_NMI, and KM_NMI_PTE
  highmem: Fix race in debug_kmap_atomic() which could cause warn_count to underflow
  rcu: Fix long-grace-period race between forcing and initialization
  uids: Prevent tear down race
2009-11-11 11:30:15 -08:00
Linus Torvalds
1fd18a871a Merge branch 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: try_one_irq() must be called with irq disabled
2009-11-11 11:29:58 -08:00
Eric Paris
dd8dbf2e68 security: report the module name to security_module_request
For SELinux to do better filtering in userspace we send the name of the
module along with the AVC denial when a program is denied module_request.

Example output:

type=SYSCALL msg=audit(11/03/2009 10:59:43.510:9) : arch=x86_64 syscall=write success=yes exit=2 a0=3 a1=7fc28c0d56c0 a2=2 a3=7fffca0d7440 items=0 ppid=1727 pid=1729 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=rpc.nfsd exe=/usr/sbin/rpc.nfsd subj=system_u:system_r:nfsd_t:s0 key=(null)
type=AVC msg=audit(11/03/2009 10:59:43.510:9) : avc:  denied  { module_request } for  pid=1729 comm=rpc.nfsd kmod="net-pf-10" scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=system

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-11-10 09:33:46 +11:00
Cyrill Gorcunov
e9036b36ee sched: Use root_task_group_empty only with FAIR_GROUP_SCHED
root_task_group_empty is used only with FAIR_GROUP_SCHED
so if we use other scheduler options we get:

  kernel/sched.c:314: warning: 'root_task_group_empty' defined but not used

So move CONFIG_FAIR_GROUP_SCHED up that it covers
root_task_group_empty().

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091026192414.GB5321@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-08 13:15:48 +01:00
Randy Dunlap
968c86458a sched: Fix kernel-doc function parameter name
Fix variable name in sched.c kernel-doc notation.

Fixes this DocBook warning:

 Warning(kernel/sched.c:2008): No description found for parameter
 'p' Warning(kernel/sched.c:2008): Excess function parameter 'k'
 description in 'kthread_bind'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
LKML-Reference: <4AF4B1BC.8020604@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-08 11:26:25 +01:00
Yong Zhang
e7e7e0c084 genirq: try_one_irq() must be called with irq disabled
Prarit reported:
=================================
[ INFO: inconsistent lock state ]
2.6.32-rc5 #1
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
 (&irq_desc_lock_class){?.-...}, at: [<ffffffff810c264e>] try_one_irq+0x32/0x138
{IN-HARDIRQ-W} state was registered at:
 [<ffffffff81095160>] __lock_acquire+0x2fc/0xd5d
 [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
 [<ffffffff814cdadd>] _spin_lock+0x40/0x89
 [<ffffffff810c3389>] handle_level_irq+0x30/0x105
 [<ffffffff81014e0e>] handle_irq+0x95/0xb7
 [<ffffffff810141bd>] do_IRQ+0x6a/0xe0
 [<ffffffff81012813>] ret_from_intr+0x0/0x16
irq event stamp: 195096
hardirqs last  enabled at (195096): [<ffffffff814cd7f7>] _spin_unlock_irq+0x3a/0x5c
hardirqs last disabled at (195095): [<ffffffff814cdbdd>] _spin_lock_irq+0x29/0x95
softirqs last  enabled at (195088): [<ffffffff81068c92>] __do_softirq+0x1c1/0x1ef
softirqs last disabled at (195093): [<ffffffff8101304c>] call_softirq+0x1c/0x30

other info that might help us debug this:
1 lock held by swapper/0:
 #0:  (kernel/irq/spurious.c:21){+.-...}, at: [<ffffffff81070cf2>]
run_timer_softirq+0x1a9/0x315

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.32-rc5 #1
Call Trace:
 <IRQ>  [<ffffffff81093e94>] valid_state+0x187/0x1ae
 [<ffffffff81093fe4>] mark_lock+0x129/0x253
 [<ffffffff810951d4>] __lock_acquire+0x370/0xd5d
 [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
 [<ffffffff814cdadd>] _spin_lock+0x40/0x89
 [<ffffffff810c264e>] try_one_irq+0x32/0x138
 [<ffffffff810c2795>] poll_all_shared_irqs+0x41/0x6d
 [<ffffffff810c27dd>] poll_spurious_irqs+0x1c/0x49
 [<ffffffff81070d82>] run_timer_softirq+0x239/0x315
 [<ffffffff81068bd3>] __do_softirq+0x102/0x1ef
 [<ffffffff8101304c>] call_softirq+0x1c/0x30
 [<ffffffff81014b65>] do_softirq+0x59/0xca
 [<ffffffff810686ad>] irq_exit+0x58/0xae
 [<ffffffff81029b84>] smp_apic_timer_interrupt+0x94/0xba
 [<ffffffff81012a33>] apic_timer_interrupt+0x13/0x20

The reason is that try_one_irq() is called from hardirq context with
interrupts disabled and from softirq context (poll_all_shared_irqs())
with interrupts enabled.

Disable interrupts before calling it from poll_all_shared_irqs().

Reported-and-tested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <1257563773-4620-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-11-07 21:44:45 +01:00
Linus Torvalds
608221fdf9 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Fix kthread_bind() by moving the body of kthread_bind() to sched.c
  sched: Disable SD_PREFER_LOCAL at node level
  sched: Fix boot crash by zalloc()ing most of the cpu masks
  sched: Strengthen buddies and mitigate buddy induced latencies
2009-11-05 10:56:47 -08:00
Linus Torvalds
72cc129e8d Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: Fix unmatched locking in ftrace_regex_write()
  ring-buffer: Synchronize resizing buffer with reader lock
2009-11-05 10:56:25 -08:00
Li Zefan
ed146b2594 ftrace: Fix unmatched locking in ftrace_regex_write()
When a command is passed to the set_ftrace_filter, then
the ftrace_regex_lock is still held going back to user space.

 # echo 'do_open : foo' > set_ftrace_filter
 (still holding ftrace_regex_lock when returning to user space!)

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4AEF7F8A.3080300@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-11-04 01:42:10 -05:00
Lai Jiangshan
f7112949f6 ring-buffer: Synchronize resizing buffer with reader lock
We got a sudden panic when we reduced the size of the
ringbuffer.

We can reproduce the panic by the following steps:

echo 1 > events/sched/enable
cat trace_pipe > /dev/null &

while ((1))
do
echo 12000 > buffer_size_kb
echo 512 > buffer_size_kb
done

(not more than 5 seconds, panic ...)

Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4AF01735.9060409@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-11-04 00:04:20 -05:00
Linus Torvalds
38dc63459f Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: Remove some debug messages producing too much noise
  PM: Fix warning on suspend errors
  PM / Hibernate: Add newline to load_image() fail path
  PM / Hibernate: Fix error handling in save_image()
  PM / Hibernate: Fix blkdev refleaks
  PM / yenta: Split resume into early and late parts (rev. 4)
2009-11-03 07:52:57 -08:00
Ian Campbell
1d51075094 Correct nr_processes() when CPUs have been unplugged
nr_processes() returns the sum of the per cpu counter process_counts for
all online CPUs. This counter is incremented for the current CPU on
fork() and decremented for the current CPU on exit(). Since a process
does not necessarily fork and exit on the same CPU the process_count for
an individual CPU can be either positive or negative and effectively has
no meaning in isolation.

Therefore calculating the sum of process_counts over only the online
CPUs omits the processes which were started or stopped on any CPU which
has since been unplugged. Only the sum of process_counts across all
possible CPUs has meaning.

The only caller of nr_processes() is proc_root_getattr() which
calculates the number of links to /proc as
        stat->nlink = proc_root.nlink + nr_processes();

You don't have to be all that unlucky for the nr_processes() to return a
negative value leading to a negative number of links (or rather, an
apparently enormous number of links). If this happens then you can get
failures where things like "ls /proc" start to fail because they got an
-EOVERFLOW from some stat() call.

Example with some debugging inserted to show what goes on:
        # ps haux|wc -l
        nr_processes: CPU0:     90
        nr_processes: CPU1:     1030
        nr_processes: CPU2:     -900
        nr_processes: CPU3:     -136
        nr_processes: TOTAL:    84
        proc_root_getattr. nlink 12 + nr_processes() 84 = 96
        84
        # echo 0 >/sys/devices/system/cpu/cpu1/online
        # ps haux|wc -l
        nr_processes: CPU0:     85
        nr_processes: CPU2:     -901
        nr_processes: CPU3:     -137
        nr_processes: TOTAL:    -953
        proc_root_getattr. nlink 12 + nr_processes() -953 = -941
        75
        # stat /proc/
        nr_processes: CPU0:     84
        nr_processes: CPU2:     -901
        nr_processes: CPU3:     -137
        nr_processes: TOTAL:    -954
        proc_root_getattr. nlink 12 + nr_processes() -954 = -942
          File: `/proc/'
          Size: 0               Blocks: 0          IO Block: 1024   directory
        Device: 3h/3d   Inode: 1           Links: 4294966354
        Access: (0555/dr-xr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
        Access: 2009-11-03 09:06:55.000000000 +0000
        Modify: 2009-11-03 09:06:55.000000000 +0000
        Change: 2009-11-03 09:06:55.000000000 +0000

I'm not 100% convinced that the per_cpu regions remain valid for offline
CPUs, although my testing suggests that they do. If not then I think the
correct solution would be to aggregate the process_count for a given CPU
into a global base value in cpu_down().

This bug appears to pre-date the transition to git and it looks like it
may even have been present in linux-2.6.0-test7-bk3 since it looks like
the code Rusty patched in http://lwn.net/Articles/64773/ was already
wrong.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-03 07:52:39 -08:00
Jiri Slaby
bf9fd67a03 PM / Hibernate: Add newline to load_image() fail path
Finish a line by \n when load_image fails in the middle of loading.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-11-03 11:03:09 +01:00
Jiri Slaby
4ff277f9e4 PM / Hibernate: Fix error handling in save_image()
There are too many retval variables in save_image(). Thus error return
value from snapshot_read_next() may be ignored and only part of the
snapshot (successfully) written.

Remove 'error' variable, invert the condition in the do-while loop
and convert the loop to use only 'ret' variable.

Switch the rest of the function to consider only 'ret'.

Also make sure we end printed line by \n if an error occurs.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-11-03 11:02:43 +01:00
Jiri Slaby
76b57e613f PM / Hibernate: Fix blkdev refleaks
While cruising through the swsusp code I found few blkdev reference
leaks of resume_bdev.

swsusp_read: remove blkdev_put altogether. Some fail paths do
             not do that.
swsusp_check: make sure we always put a reference on fail paths
software_resume: all fail paths between swsusp_check and swsusp_read
                 omit swsusp_close. Add it in those cases. And since
                 swsusp_read doesn't drop the reference anymore, do
                 it here unconditionally.

[rjw: Fixed a small coding style issue.]

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-11-03 11:01:46 +01:00
Mike Galbraith
b84ff7d6f1 sched: Fix kthread_bind() by moving the body of kthread_bind() to sched.c
Eric Paris reported that commit
f685ceacab causes boot time
PREEMPT_DEBUG complaints.

 [    4.590699] BUG: using smp_processor_id() in preemptible [00000000] code: rmmod/1314
 [    4.593043] caller is task_hot+0x86/0xd0

Since kthread_bind() messes with scheduler internals, move the
body to sched.c, and lock the runqueue.

Reported-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Tested-by: Eric Paris <eparis@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1256813310.7574.3.camel@marge.simson.net>
[ v2: fix !SMP build and clean up ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-03 07:25:00 +01:00
Linus Torvalds
3fe866ca6c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Fix spurious wakeup for requeue_pi really
2009-11-02 09:46:33 -08:00
Linus Torvalds
bce8fc4cb7 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tools: Remove -Wcast-align
  perf tools: Fix compatibility with libelf 0.8 and autodetect
  perf events: Don't generate events for the idle task when exclude_idle is set
  perf events: Fix swevent hrtimer sampling by keeping track of remaining time when enabling/disabling swevent hrtimers
2009-11-02 09:46:06 -08:00
Linus Torvalds
a5e3013d66 Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: Remove cpu arg from the rb_time_stamp() function
  tracing: Fix comment typo and documentation example
  tracing: Fix trace_seq_printf() return value
  tracing: Update *ppos instead of filp->f_pos
2009-11-02 09:45:44 -08:00
Paul E. McKenney
83f5b01ffb rcu: Fix long-grace-period race between forcing and initialization
Very long RCU read-side critical sections (50 milliseconds or
so) can cause a race between force_quiescent_state() and
rcu_start_gp() as follows on kernel builds with multi-level
rcu_node hierarchies:

1.	CPU 0 calls force_quiescent_state(), sees that there is a
	grace period in progress, and acquires ->fsqlock.

2.	CPU 1 detects the end of the grace period, and so
	cpu_quiet_msk_finish() sets rsp->completed to rsp->gpnum.
	This operation is carried out under the root rnp->lock,
	but CPU 0 has not yet acquired that lock.  Note that
	rsp->signaled is still RCU_SAVE_DYNTICK from the last
	grace period.

3.	CPU 1 calls rcu_start_gp(), but no one wants a new grace
	period, so it drops the root rnp->lock and returns.

4.	CPU 0 acquires the root rnp->lock and picks up rsp->completed
	and rsp->signaled, then drops rnp->lock.  It then enters the
	RCU_SAVE_DYNTICK leg of the switch statement.

5.	CPU 2 invokes call_rcu(), and now needs a new grace period.
	It calls rcu_start_gp(), which acquires the root rnp->lock, sets
	rsp->signaled to RCU_GP_INIT (too bad that CPU 0 is already in
	the RCU_SAVE_DYNTICK leg of the switch statement!)  and starts
	initializing the rcu_node hierarchy.  If there are multiple
	levels to the hierarchy, it will drop the root rnp->lock and
	initialize the lower levels of the hierarchy.

6.	CPU 0 notes that rsp->completed has not changed, which permits
        both CPU 2 and CPU 0 to try updating it concurrently.  If CPU 0's
	update prevails, later calls to force_quiescent_state() can
	count old quiescent states against the new grace period, which
	can in turn result in premature ending of grace periods.

	Not good.

This patch adds an RCU_GP_IDLE state for rsp->signaled that is
set initially at boot time and any time a grace period ends.
This prevents CPU 0 from getting into the workings of
force_quiescent_state() in step 4.  Additional locking and
checks prevent the concurrent update of rsp->signaled in step 6.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1256742889199-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 16:06:21 +01:00
Thomas Gleixner
b00bc0b237 uids: Prevent tear down race
Ingo triggered the following warning:

WARNING: at lib/debugobjects.c:255 debug_print_object+0x42/0x50()
Hardware name: System Product Name
ODEBUG: init active object type: timer_list
Modules linked in:
Pid: 2619, comm: dmesg Tainted: G        W  2.6.32-rc5-tip+ #5298
Call Trace:
 [<81035443>] warn_slowpath_common+0x6a/0x81
 [<8120e483>] ? debug_print_object+0x42/0x50
 [<81035498>] warn_slowpath_fmt+0x29/0x2c
 [<8120e483>] debug_print_object+0x42/0x50
 [<8120ec2a>] __debug_object_init+0x279/0x2d7
 [<8120ecb3>] debug_object_init+0x13/0x18
 [<810409d2>] init_timer_key+0x17/0x6f
 [<81041526>] free_uid+0x50/0x6c
 [<8104ed2d>] put_cred_rcu+0x61/0x72
 [<81067fac>] rcu_do_batch+0x70/0x121

debugobjects warns about an enqueued timer being initialized. If
CONFIG_USER_SCHED=y the user management code uses delayed work to
remove the user from the hash table and tear down the sysfs objects.

free_uid is called from RCU and initializes/schedules delayed work if
the usage count of the user_struct is 0. The init/schedule happens
outside of the uidhash_lock protected region which allows a concurrent
caller of find_user() to reference the about to be destroyed
user_struct w/o preventing the work from being scheduled. If the next
free_uid call happens before the work timer expired then the active
timer is initialized and the work scheduled again.

The race was introduced in commit 5cb350ba (sched: group scheduling,
sysfs tunables) and made more prominent by commit 3959214f (sched:
delayed cleanup of user_struct)

Move the init/schedule_delayed_work inside of the uidhash_lock
protected region to prevent the race.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@us.ibm.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: stable@kernel.org
2009-11-02 16:02:39 +01:00
Rusty Russell
49557e6203 sched: Fix boot crash by zalloc()ing most of the cpu masks
I got a boot crash when forcing cpumasks offstack on 32 bit,
because find_new_ilb() returned 3 on my UP system (nohz.cpu_mask
wasn't zeroed).

AFAICT the others need to be zeroed too: only
nohz.ilb_grp_nohz_mask is initialized before use.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <200911022037.21282.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-02 15:48:54 +01:00
Linus Torvalds
8633322c5f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  sched: move rq_weight data array out of .percpu
  percpu: allow pcpu_alloc() to be called with IRQs off
2009-10-29 09:19:29 -07:00
Linus Torvalds
9532faeb29 Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-param-fixes
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-param-fixes:
  param: fix setting arrays of bool
  param: fix NULL comparison on oom
  param: fix lots of bugs with writing charp params from sysfs, by leaking mem.
2009-10-29 09:18:20 -07:00
Linus Torvalds
3242f9804b Merge branch 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6
* 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6:
  HWPOISON: fix invalid page count in printk output
  HWPOISON: Allow schedule_on_each_cpu() from keventd
  HWPOISON: fix/proc/meminfo alignment
  HWPOISON: fix oops on ksm pages
  HWPOISON: Fix page count leak in hwpoison late kill in do_swap_page
  HWPOISON: return early on non-LRU pages
  HWPOISON: Add brief hwpoison description to Documentation
  HWPOISON: Clean up PR_MCE_KILL interface
2009-10-29 08:20:00 -07:00
Linus Torvalds
fefcfd431b Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Move drop_futex_key_refs out of spinlock'ed region
  rcu: Fix TREE_PREEMPT_RCU CPU_HOTPLUG bad-luck hang
  rcu: Stopgap fix for synchronize_rcu_expedited() for TREE_PREEMPT_RCU
  rcu: Prevent RCU IPI storms in presence of high call_rcu() load
  futex: Check for NULL keys in match_futex
  futex: Handle spurious wake up
2009-10-29 08:12:20 -07:00
Linus Torvalds
37c2ca2411 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf timechart: Improve the visual appearance of scheduler delays
  perf timechart: Fix the wakeup-arrows that point to non-visible processes
  perf top: Fix --delay_secs 0 division by zero
  perf tools: Bump version to 0.0.2
  perf_event: Adjust frequency and unthrottle for non-group-leader events
2009-10-29 08:12:00 -07:00
Linus Torvalds
6e958d73c2 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Do less agressive buddy clearing
  sched: Disable SD_PREFER_LOCAL for MC/CPU domains
2009-10-29 08:10:38 -07:00
Alexey Dobriyan
8c85dd8730 sysctl: fix false positives when PROC_SYSCTL=n
Having ->procname but not ->proc_handler is valid when PROC_SYSCTL=n,
people use such combination to reduce ifdefs with non-standard handlers.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=14408

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: Peter Teoh <htmldeveloper@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-29 07:39:30 -07:00
KOSAKI Motohiro
478988d3b2 cgroup: fix strstrip() misuse
cgroup_write_X64() and cgroup_write_string() ignore the return value of
strstrip().  it makes small inconsistent behavior.

example:
=========================
 # cd /mnt/cgroup/hoge
 # cat memory.swappiness
 60
 # echo "59 " > memory.swappiness
 # cat memory.swappiness
 59
 # echo " 58" > memory.swappiness
 bash: echo: write error: Invalid argument

This patch fixes it.

Cc: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
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>
2009-10-29 07:39:25 -07:00