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| author | Pravin B Shelar <pshelar@nicira.com> | 2012-06-20 12:52:56 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-07-16 09:03:49 -0700 |
| commit | d3ae4a87530c1e10c0705995c87fe8a7b4267f4b (patch) | |
| tree | 3881f8a77c7788fd8720b5c680f3feca5aa87a6d /arch/powerpc/kernel | |
| parent | 3cc270f7fcd34b08d37ed51fb4c25b0f513f2e65 (diff) | |
| download | lwn-d3ae4a87530c1e10c0705995c87fe8a7b4267f4b.tar.gz lwn-d3ae4a87530c1e10c0705995c87fe8a7b4267f4b.zip | |
mm: fix slab->page _count corruption when using slub
commit abca7c4965845924f65d40e0aa1092bdd895e314 upstream.
On arches that do not support this_cpu_cmpxchg_double() slab_lock is used
to do atomic cmpxchg() on double word which contains page->_count. The
page count can be changed from get_page() or put_page() without taking
slab_lock. That corrupts page counter.
Fix it by moving page->_count out of cmpxchg_double data. So that slub
does no change it while updating slub meta-data in struct page.
[akpm@linux-foundation.org: use standard comment layout, tweak comment text]
Reported-by: Amey Bhide <abhide@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/powerpc/kernel')
0 files changed, 0 insertions, 0 deletions