David Rientjes 43362a4977 oom: fix race while temporarily setting current's oom_score_adj ... test_set_oom_score_adj() was introduced in 72788c3856 ("oom: replace PF_OOM_ORIGIN with toggling oom_score_adj") to temporarily elevate current's oom_score_adj for ksm and swapoff without requiring an additional per-process flag. Using that function to both set oom_score_adj to OOM_SCORE_ADJ_MAX and then reinstate the previous value is racy since it's possible that userspace can set the value to something else itself before the old value is reinstated. That results in userspace setting current's oom_score_adj to a different value and then the kernel immediately setting it back to its previous value without notification. To fix this, a new compare_swap_oom_score_adj() function is introduced with the same semantics as the compare and swap CAS instruction, or CMPXCHG on x86. It is used to reinstate the previous value of oom_score_adj if and only if the present value is the same as the old value. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ying Han <yinghan@google.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>		2011-10-31 17:30:45 -07:00
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acpi
asm-generic	dma-mapping: fix sync_single_range_* DMA debugging	2011-10-31 17:30:44 -07:00
crypto
drm	Revert "drm/ttm: add a way to bo_wait for either the last read or last write"	2011-10-27 18:28:37 +02:00
keys
linux	oom: fix race while temporarily setting current's oom_score_adj	2011-10-31 17:30:45 -07:00
math-emu
media
mtd
net	ipv6: tcp: fix TCLASS value in ACK messages sent from TIME_WAIT	2011-10-27 00:44:35 -04:00
pcmcia
rdma
rxrpc
scsi	Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6	2011-10-28 16:44:18 -07:00
sound	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound	2011-10-28 14:25:01 -07:00
target	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-10-25 12:11:02 +02:00
trace	mm: change isolate mode from #define to bitwise type	2011-10-31 17:30:44 -07:00
video
xen	Merge branches 'stable/drivers-3.2', 'stable/drivers.bugfixes-3.2' and 'stable/pci.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen	2011-10-25 09:19:36 +02:00
Kbuild