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
..
backing-dev.c	mm: Add comment explaining task state setting in bdi_forker_thread()	2011-09-02 17:17:02 -06:00
bootmem.c	crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn	2011-03-23 19:47:19 -07:00
bounce.c	bounce: call flush_dcache_page() after bounce_copy_vec()	2010-09-09 18:57:25 -07:00
cleancache.c	mm: cleancache core ops functions and config	2011-05-26 10:01:36 -06:00
compaction.c	mm: compaction: make isolate_lru_page() filter-aware	2011-10-31 17:30:44 -07:00
debug-pagealloc.c
dmapool.c	devres: fix possible use after free	2011-07-25 20:57:14 -07:00
fadvise.c	readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM	2010-03-06 11:26:25 -08:00
failslab.c	fault-injection: add ability to export fault_attr in arbitrary directory	2011-08-03 14:25:20 -10:00
filemap_xip.c	mm: Convert i_mmap_lock to a mutex	2011-05-25 08:39:18 -07:00
filemap.c	vfs: iov_iter: have iov_iter_advance decrement nr_segs appropriately	2011-10-28 13:55:08 +02:00
fremap.c	mm: don't access vm_flags as 'int'	2011-05-26 09:20:31 -07:00
highmem.c	mm: make HASHED_PAGE_VIRTUAL page_address' struct page argument const.	2011-08-17 13:00:20 -07:00
huge_memory.c	mm/huge_memory.c: minor lock simplification in __khugepaged_exit	2011-07-25 20:57:09 -07:00
hugetlb.c	mm: hugetlb: fix coding style issues	2011-07-25 20:57:09 -07:00
hwpoison-inject.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
init-mm.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
internal.h	mm: nommu: sort mm->mmap list properly	2011-05-25 08:39:05 -07:00
Kconfig	mm Kconfig typo: cleancacne -> cleancache	2011-06-10 14:47:52 +02:00
Kconfig.debug	mm: debug-pagealloc: fix kconfig dependency warning	2011-03-22 17:44:02 -07:00
kmemcheck.c	kmemcheck: Fix build errors due to missing slab.h	2010-03-30 22:02:32 +09:00
kmemleak-test.c	kmemleak: remove memset by using kzalloc	2011-01-27 18:31:51 +00:00
kmemleak.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
ksm.c	oom: fix race while temporarily setting current's oom_score_adj	2011-10-31 17:30:45 -07:00
maccess.c	maccess,probe_kernel: Make write/read src const void *	2011-05-25 19:56:23 -04:00
madvise.c	fs: kill i_alloc_sem	2011-07-20 20:47:46 -04:00
Makefile	Cross Memory Attach	2011-10-31 17:30:44 -07:00
memblock.c	mm/memblock.c: avoid abuse of RED_INACTIVE	2011-07-25 20:57:09 -07:00
memcontrol.c	mm: change isolate mode from #define to bitwise type	2011-10-31 17:30:44 -07:00
memory_hotplug.c	mm: extend memory hotplug API to allow memory hotplug in virtual machines	2011-07-25 20:57:08 -07:00
memory-failure.c	HWPoison: add memory_failure_queue()	2011-08-03 11:15:58 -04:00
memory.c	mm/futex: fix futex writes on archs with SW tracking of dirty & young	2011-07-25 20:57:11 -07:00
mempolicy.c	mm/mempolicy.c: make copy_from_user() provably correct	2011-09-14 18:09:36 -07:00
mempool.c	mm: remove broken 'kzalloc' mempool	2009-09-22 07:17:35 -07:00
migrate.c	mm: migration: clean up unmap_and_move()	2011-10-31 17:30:45 -07:00
mincore.c	mm: clarify the radix_tree exceptional cases	2011-08-03 14:25:24 -10:00
mlock.c	mm: don't access vm_flags as 'int'	2011-05-26 09:20:31 -07:00
mm_init.c
mmap.c	mmap: fix and tidy up overcommit page arithmetic	2011-07-25 20:57:09 -07:00
mmu_context.c	exit: fix oops in sync_mm_rss	2010-03-24 16:31:21 -07:00
mmu_notifier.c	thp: mmu_notifier_test_young	2011-01-13 17:32:46 -08:00
mmzone.c	mm: page allocator: adjust the per-cpu counter threshold when memory is low	2011-01-13 17:32:31 -08:00
mprotect.c	thp: mprotect: transparent huge page support	2011-01-13 17:32:44 -08:00
mremap.c	mm: Convert i_mmap_lock to a mutex	2011-05-25 08:39:18 -07:00
msync.c	sanitize vfs_fsync calling conventions	2010-05-21 18:31:21 -04:00
nobootmem.c	memblock/nobootmem: remove unneeded code from alloc_bootmem_node_high()	2011-05-25 08:39:31 -07:00
nommu.c	mmap: fix and tidy up overcommit page arithmetic	2011-07-25 20:57:09 -07:00
oom_kill.c	oom: fix race while temporarily setting current's oom_score_adj	2011-10-31 17:30:45 -07:00
page_alloc.c	fault-injection: add ability to export fault_attr in arbitrary directory	2011-08-03 14:25:20 -10:00
page_cgroup.c	mm: Convert vmalloc/memset to vzalloc	2011-09-15 13:56:56 +02:00
page_io.c	block: kill off REQ_UNPLUG	2011-03-10 08:52:27 +01:00
page_isolation.c	mm: page_isolation: codeclean fix comment and rm unneeded val init	2010-10-26 16:52:11 -07:00
page-writeback.c	mm/page-writeback.c: document bdi_min_ratio	2011-10-31 17:30:45 -07:00
pagewalk.c	pagewalk: fix code comment for THP	2011-07-25 20:57:09 -07:00
percpu-km.c	percpu: clear memory allocated with the km allocator	2010-10-02 10:28:42 +03:00
percpu-vm.c	mm: remove gfp mask from pcpu_get_vm_areas	2011-01-13 17:32:34 -08:00
percpu.c	Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2011-05-24 11:53:42 -07:00
pgtable-generic.c	mm/pgtable-generic.c: fix CONFIG_SWAP=n build	2011-01-26 10:49:58 +10:00
prio_tree.c	sanitize <linux/prefetch.h> usage	2011-05-20 12:50:29 -07:00
process_vm_access.c	Cross Memory Attach	2011-10-31 17:30:44 -07:00
quicklist.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
readahead.c	readahead: readahead page allocations are OK to fail	2011-05-25 08:39:25 -07:00
rmap.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback	2011-07-26 10:39:54 -07:00
shmem.c	Merge branch 'next-evm' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/ima-2.6 into next	2011-08-09 10:31:03 +10:00
slab.c	mm: restrict access to slab files under procfs and sysfs	2011-09-27 22:59:27 +03:00
slob.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
slub.c	Merge branches 'slab/next' and 'slub/partial' into slab/for-linus	2011-10-26 18:09:12 +03:00
sparse-vmemmap.c	tree-wide: fix comment/printk typos	2010-11-01 15:38:34 -04:00
sparse.c	mm: make some struct page's const	2011-07-25 20:57:07 -07:00
swap_state.c	block: remove per-queue plugging	2011-03-10 08:52:07 +01:00
swap.c	mm: batch activate_page() to reduce lock contention	2011-05-25 08:39:37 -07:00
swapfile.c	oom: fix race while temporarily setting current's oom_score_adj	2011-10-31 17:30:45 -07:00
thrash.c	mm: swap-token: add a comment for priority aging	2011-07-25 20:57:08 -07:00
truncate.c	mm: a few small updates for radix-swap	2011-08-03 14:25:24 -10:00
util.c	mm: nommu: sort mm->mmap list properly	2011-05-25 08:39:05 -07:00
vmalloc.c	mm: sync vmalloc address space page tables in alloc_vm_area()	2011-09-14 18:09:38 -07:00
vmscan.c	vmscan: add block plug for page reclaim	2011-10-31 17:30:45 -07:00
vmstat.c	numa: fix NUMA compile error when sysfs and procfs are disabled	2011-09-14 18:09:37 -07:00