linux/include
Oleg Nesterov ad474caca3 fix for account_group_exec_runtime(), make sure ->signal can't be freed under rq->lock
Impact: fix hang/crash on ia64 under high load

This is ugly, but the simplest patch by far.

Unlike other similar routines, account_group_exec_runtime() could be
called "implicitly" from within scheduler after exit_notify(). This
means we can race with the parent doing release_task(), we can't just
check ->signal != NULL.

Change __exit_signal() to do spin_unlock_wait(&task_rq(tsk)->lock)
before __cleanup_signal() to make sure ->signal can't be freed under
task_rq(tsk)->lock. Note that task_rq_unlock_wait() doesn't care
about the case when tsk changes cpu/rq under us, this should be OK.

Thanks to Ingo who nacked my previous buggy patch.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Doug Chapman <doug.chapman@hp.com>
2008-11-11 08:01:43 +01:00
..
acpi Merge branch 'linus' into test 2008-10-23 00:11:07 -04:00
asm-arm
asm-frv
asm-generic Fix __pfn_to_page(pfn) for CONFIG_DISCONTIGMEM=y 2008-11-08 10:02:48 -08:00
asm-h8300
asm-m32r
asm-m68k proc: move /proc/hardware to m68k-specific code 2008-10-23 14:24:03 +04:00
asm-mn10300
asm-x86 x86: add iomap_atomic*()/iounmap_atomic() on 32-bit using fixmaps 2008-10-31 10:12:38 +01:00
asm-xtensa Merge git://git.kernel.org/pub/scm/linux/kernel/git/czankel/xtensa-2.6 2008-10-23 09:16:56 -07:00
crypto
drm i915: Add GEM ioctl to get available aperture size. 2008-11-03 10:56:49 +10:00
keys
linux fix for account_group_exec_runtime(), make sure ->signal can't be freed under rq->lock 2008-11-11 08:01:43 +01:00
math-emu math-emu: Fix thinko in _FP_DIV 2008-10-22 22:09:59 -07:00
media
mtd
net net: unix: fix inflight counting bug in garbage collector 2008-11-09 11:17:33 -08:00
pcmcia
rdma
rxrpc
scsi scsi: make sure that scsi_init_shared_tag_map() doesn't overwrite existing map 2008-10-27 19:25:30 +01:00
sound Merge branches 'topic/fix/misc' and 'topic/fix/asoc' into for-linus 2008-10-30 14:26:24 +01:00
trace
video
xen
Kbuild