mm: fix slab->page _count corruption when using slub
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.
[[email protected]: use standard comment layout, tweak comment text]
Reported-by: Amey Bhide <[email protected]>
Signed-off-by: Pravin B Shelar <[email protected]>
Acked-by: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
1 file changed
