From: Yu Zhao <yuzhao@xxxxxxxxxx> Subject: mm: use unsigned long constant for page flags struct page->flags is unsigned long, so when shifting bits we should use UL suffix to match it. Found this problem after I added 64-bit CPU specific page flags and failed to compile the kernel: mm/page_alloc.c: In function '__free_one_page': mm/page_alloc.c:672:2: error: integer overflow in expression [-Werror=overflow] Link: http://lkml.kernel.org/r/1461971723-16187-1-git-send-email-yuzhao@xxxxxxxxxx Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx> Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Jerome Marchand <jmarchan@xxxxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/page-flags.h | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff -puN include/linux/page-flags.h~mm-use-unsigned-long-constant-for-page-flags include/linux/page-flags.h --- a/include/linux/page-flags.h~mm-use-unsigned-long-constant-for-page-flags +++ a/include/linux/page-flags.h @@ -479,7 +479,7 @@ static inline void ClearPageCompound(str } #endif -#define PG_head_mask ((1L << PG_head)) +#define PG_head_mask ((1UL << PG_head)) #ifdef CONFIG_HUGETLB_PAGE int PageHuge(struct page *page); @@ -670,7 +670,7 @@ static inline void ClearPageSlabPfmemall } #ifdef CONFIG_MMU -#define __PG_MLOCKED (1 << PG_mlocked) +#define __PG_MLOCKED (1UL << PG_mlocked) #else #define __PG_MLOCKED 0 #endif @@ -680,11 +680,11 @@ static inline void ClearPageSlabPfmemall * these flags set. It they are, there is a problem. */ #define PAGE_FLAGS_CHECK_AT_FREE \ - (1 << PG_lru | 1 << PG_locked | \ - 1 << PG_private | 1 << PG_private_2 | \ - 1 << PG_writeback | 1 << PG_reserved | \ - 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ - 1 << PG_unevictable | __PG_MLOCKED) + (1UL << PG_lru | 1UL << PG_locked | \ + 1UL << PG_private | 1UL << PG_private_2 | \ + 1UL << PG_writeback | 1UL << PG_reserved | \ + 1UL << PG_slab | 1UL << PG_swapcache | 1UL << PG_active | \ + 1UL << PG_unevictable | __PG_MLOCKED) /* * Flags checked when a page is prepped for return by the page allocator. @@ -695,10 +695,10 @@ static inline void ClearPageSlabPfmemall * alloc-free cycle to prevent from reusing the page. */ #define PAGE_FLAGS_CHECK_AT_PREP \ - (((1 << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) + (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) #define PAGE_FLAGS_PRIVATE \ - (1 << PG_private | 1 << PG_private_2) + (1UL << PG_private | 1UL << PG_private_2) /** * page_has_private - Determine if page has private stuff * @page: The page to be checked _ -- 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
