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raw | patch | inline | side by side (parent: 12aee27)
raw | patch | inline | side by side (parent: 12aee27)
author | Johannes Weiner <hannes@cmpxchg.org> | |
Thu, 31 Oct 2013 23:34:13 +0000 (16:34 -0700) | ||
committer | Linus Torvalds <torvalds@linux-foundation.org> | |
Thu, 31 Oct 2013 23:58:13 +0000 (16:58 -0700) |
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>
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>
mm/memcontrol.c | patch | blob | history |
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 497ec33ff22d6de772e761c6d13394480b266dc6..623d5c8bb1e16a10807282f0d58fe7aa23a5d3ce 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
*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;