The patch titled Subject: mm: fix slab->page _count corruption when using slub has been removed from the -mm tree. Its filename was mm-fix-slab-page-_count-corruption-when-using-slub.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ From: Pravin B Shelar <pshelar@xxxxxxxxxx> Subject: 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. [akpm@xxxxxxxxxxxxxxxxxxxx: use standard comment layout, tweak comment text] Reported-by: Amey Bhide <abhide@xxxxxxxxxx> Signed-off-by: Pravin B Shelar <pshelar@xxxxxxxxxx> Acked-by: Christoph Lameter <cl@xxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm_types.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff -puN include/linux/mm_types.h~mm-fix-slab-page-_count-corruption-when-using-slub include/linux/mm_types.h --- a/include/linux/mm_types.h~mm-fix-slab-page-_count-corruption-when-using-slub +++ a/include/linux/mm_types.h @@ -57,8 +57,18 @@ struct page { }; union { +#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ + defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) /* Used for cmpxchg_double in slub */ unsigned long counters; +#else + /* + * Keep _count separate from slub cmpxchg_double data. + * As the rest of the double word is protected by + * slab_lock but _count is not. + */ + unsigned counters; +#endif struct { _ Patches currently in -mm which might be from pshelar@xxxxxxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html