Andrey Vagin 20afc60f89 x86, perf: Check that current->mm is alive before getting user callchain ... An event may occur when an mm is already released. I added an event in dequeue_entity() and caught a panic with the following backtrace: [ 434.421110] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050 [ 434.421258] IP: [<ffffffff810464ac>] __get_user_pages_fast+0x9c/0x120 ... [ 434.421258] Call Trace: [ 434.421258] [<ffffffff8101ae81>] copy_from_user_nmi+0x51/0xf0 [ 434.421258] [<ffffffff8109a0d5>] ? sched_clock_local+0x25/0x90 [ 434.421258] [<ffffffff8101b048>] perf_callchain_user+0x128/0x170 [ 434.421258] [<ffffffff811154cd>] ? __perf_event_header__init_id+0xed/0x100 [ 434.421258] [<ffffffff81116690>] perf_prepare_sample+0x200/0x280 [ 434.421258] [<ffffffff81118da8>] __perf_event_overflow+0x1b8/0x290 [ 434.421258] [<ffffffff81065240>] ? tg_shares_up+0x0/0x670 [ 434.421258] [<ffffffff8104fe1a>] ? walk_tg_tree+0x6a/0xb0 [ 434.421258] [<ffffffff81118f44>] perf_swevent_overflow+0xc4/0xf0 [ 434.421258] [<ffffffff81119150>] do_perf_sw_event+0x1e0/0x250 [ 434.421258] [<ffffffff81119204>] perf_tp_event+0x44/0x70 [ 434.421258] [<ffffffff8105701f>] ftrace_profile_sched_block+0xdf/0x110 [ 434.421258] [<ffffffff8106121d>] dequeue_entity+0x2ad/0x2d0 [ 434.421258] [<ffffffff810614ec>] dequeue_task_fair+0x1c/0x60 [ 434.421258] [<ffffffff8105818a>] dequeue_task+0x9a/0xb0 [ 434.421258] [<ffffffff810581e2>] deactivate_task+0x42/0xe0 [ 434.421258] [<ffffffff814bc019>] thread_return+0x191/0x808 [ 434.421258] [<ffffffff81098a44>] ? switch_task_namespaces+0x24/0x60 [ 434.421258] [<ffffffff8106f4c4>] do_exit+0x464/0x910 [ 434.421258] [<ffffffff8106f9c8>] do_group_exit+0x58/0xd0 [ 434.421258] [<ffffffff8106fa57>] sys_exit_group+0x17/0x20 [ 434.421258] [<ffffffff8100b202>] system_call_fastpath+0x16/0x1b Signed-off-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Link: http://lkml.kernel.org/r/1314693156-24131-1-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar <mingo@elte.hu>		2011-08-31 15:56:31 +02:00
..
boot	x86, build: Do not set the root_dev field in bzImage	2011-05-25 12:46:05 -07:00
configs	cgroup: remove the ns_cgroup	2011-05-26 17:12:34 -07:00
crypto	crypto: ghash-intel - Fix set but not used in ghash_async_setkey()	2011-06-30 07:43:42 +08:00
ia32	All Arch: remove linkage for sys_nfsservctl system call	2011-08-26 15:09:58 -07:00
include/asm	All Arch: remove linkage for sys_nfsservctl system call	2011-08-26 15:09:58 -07:00
kernel	x86, perf: Check that current->mm is alive before getting user callchain	2011-08-31 15:56:31 +02:00
kvm	Merge branch 'kvm-updates/3.1' of git://git.kernel.org/pub/scm/virt/kvm/kvm	2011-08-16 11:14:44 -07:00
lguest	lguest: Fix translation count about wikipedia's cpuid page	2011-07-22 14:39:50 +09:30
lib	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
math-emu
mm	x86: fix mm/fault.c build	2011-08-15 19:10:50 -07:00
net	net: filter: Just In Time compiler for x86-64	2011-04-27 23:05:08 -07:00
oprofile	x86, perf: Make copy_from_user_nmi() a library function	2011-07-21 20:41:57 +02:00
pci	PCI: Set PCI-E Max Payload Size on fabric	2011-08-01 11:49:16 -07:00
platform	sfi: table irq 0xFF means 'no interrupt'	2011-08-26 09:03:29 -07:00
power
tools
vdso	Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2011-08-23 18:09:08 -07:00
video
xen	Merge branch 'stable/bug.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen	2011-08-22 11:25:44 -07:00
.gitignore
Kbuild	net: filter: Just In Time compiler for x86-64	2011-04-27 23:05:08 -07:00
Kconfig	Merge commit 'v3.0' into x86/vdso	2011-08-04 16:13:20 -07:00
Kconfig.cpu	x86: Add support for cmpxchg_double	2011-06-25 12:17:32 -07:00
Kconfig.debug	lib: consolidate DEBUG_STACK_USAGE option	2011-05-25 08:39:54 -07:00
Makefile
Makefile_32.cpu	x86, cpu: Move AMD Elan Kconfig under "Processor family"	2011-04-08 13:01:25 -07:00