| Message ID | 35FD53F367049845BC99AC72306C23D103E688B313F5@CNBJMBX05.corpusers.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Dec 08, 2014 at 03:47:47PM +0800, Wang, Yalin wrote: > 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.wang@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)); VM_BUG_ON_PAGE(), please.
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)
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.wang@sonymobile.com> --- include/linux/mm.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)