diff options
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index e0c8528a41a..a9a48309f04 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -361,8 +361,18 @@ static inline void compound_unlock_irqrestore(struct page *page, static inline struct page *compound_head(struct page *page) { - if (unlikely(PageTail(page))) - return page->first_page; + if (unlikely(PageTail(page))) { + struct page *head = page->first_page; + + /* + * page->first_page may be a dangling pointer to an old + * compound page, so recheck that it is still a tail + * page before returning. + */ + smp_rmb(); + if (likely(PageTail(page))) + return head; + } return page; } @@ -766,11 +776,14 @@ static __always_inline void *lowmem_page_address(const struct page *page) #endif #if defined(WANT_PAGE_VIRTUAL) -#define page_address(page) ((page)->virtual) -#define set_page_address(page, address) \ - do { \ - (page)->virtual = (address); \ - } while(0) +static inline void *page_address(const struct page *page) +{ + return page->virtual; +} +static inline void set_page_address(struct page *page, void *address) +{ + page->virtual = address; +} #define page_address_init() do { } while(0) #endif |