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| author | Johannes Weiner <hannes@cmpxchg.org> | 2013-10-31 16:34:13 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-10-31 16:58:13 -0700 |
| commit | 3168ecbe1c04ec3feb7cb42388a17d7f047fe1a2 (patch) | |
| tree | b8e0a03d787c2219b1d1fd833193de7abc59442e | |
| parent | 12aee278b50c4a94a93fa0b4d201ae35d792c696 (diff) | |
| download | linux-3168ecbe1c04ec3feb7cb42388a17d7f047fe1a2.tar.bz2 | |
mm: memcg: use proper memcg in limit bypass
Commit 84235de394d9 ("fs: buffer: move allocation failure loop into the
allocator") allowed __GFP_NOFAIL allocations to bypass the limit if they
fail to reclaim enough memory for the charge. But because the main test
case was on a 3.2-based system, the patch missed the fact that on newer
kernels the charge function needs to return root_mem_cgroup when
bypassing the limit, and not NULL. This will corrupt whatever memory is
at NULL + percpu pointer offset. Fix this quickly before problems are
reported.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memcontrol.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 497ec33ff22d..623d5c8bb1e1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2765,10 +2765,10 @@ done: *ptr = memcg; return 0; nomem: - *ptr = NULL; - if (gfp_mask & __GFP_NOFAIL) - return 0; - return -ENOMEM; + if (!(gfp_mask & __GFP_NOFAIL)) { + *ptr = NULL; + return -ENOMEM; + } bypass: *ptr = root_mem_cgroup; return -EINTR; |