This patch add VM_BUG_ON() for slab page, because _mapcount is an union with slab struct in struct page, avoid access _mapcount if this page is a slab page. Also remove the unneeded bracket.
Signed-off-by: Yalin Wang <yalin.w...@sonymobile.com> --- include/linux/mm.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 11b65cf..34124c4 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -373,7 +373,8 @@ static inline void reset_page_mapcount(struct page *page) static inline int page_mapcount(struct page *page) { - return atomic_read(&(page)->_mapcount) + 1; + VM_BUG_ON(PageSlab(page)); + return atomic_read(&page->_mapcount) + 1; } static inline int page_count(struct page *page) -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/