[PATCH V3] mm:add VM_BUG_ON_PAGE() for page_mapcount()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This patch add VM_BUG_ON_PAGE() 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.wang@xxxxxxxxxxxxxx>
---
 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 b464611..a117527 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -449,7 +449,8 @@ static inline void page_mapcount_reset(struct page *page)
 
 static inline int page_mapcount(struct page *page)
 {
-	return atomic_read(&(page)->_mapcount) + 1;
+	VM_BUG_ON_PAGE(PageSlab(page), page);
+	return atomic_read(&page->_mapcount) + 1;
 }
 
 static inline int page_count(struct page *page)
-- 
2.1.3
��.n������g����a����&ޖ)���)��h���&������梷�����Ǟ�m������)������^�����������v���O��zf������





[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]