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| author | Oleg Nesterov <oleg@redhat.com> | 2013-07-31 13:53:28 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-31 14:41:02 -0700 |
| commit | 3964acd0dbec123aa0a621973a2a0580034b4788 (patch) | |
| tree | eb5bcfb186354c2ebfa6b0b07c37156b34d21e9e /mm/mmap.c | |
| parent | 36f571e9ed0419e73d127e18aa8992ced867268c (diff) | |
| download | blackbird-op-linux-3964acd0dbec123aa0a621973a2a0580034b4788.tar.gz blackbird-op-linux-3964acd0dbec123aa0a621973a2a0580034b4788.zip | |
mm: mempolicy: fix mbind_range() && vma_adjust() interaction
vma_adjust() does vma_set_policy(vma, vma_policy(next)) and this
is doubly wrong:
1. This leaks vma->vm_policy if it is not NULL and not equal to
next->vm_policy.
This can happen if vma_merge() expands "area", not prev (case 8).
2. This sets the wrong policy if vma_merge() joins prev and area,
area is the vma the caller needs to update and it still has the
old policy.
Revert commit 1444f92c8498 ("mm: merging memory blocks resets
mempolicy") which introduced these problems.
Change mbind_range() to recheck mpol_equal() after vma_merge() to fix
the problem that commit tried to address.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Steven T Hampson <steven.t.hampson@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index fbad7b091090..1edbaa3136c3 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -865,7 +865,7 @@ again: remove_next = 1 + (end > next->vm_end); if (next->anon_vma) anon_vma_merge(vma, next); mm->map_count--; - vma_set_policy(vma, vma_policy(next)); + mpol_put(vma_policy(next)); kmem_cache_free(vm_area_cachep, next); /* * In mprotect's case 6 (see comments on vma_merge), |
