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@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index a61e06e..e5a3244 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -479,7 +479,7 @@
}
#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 @@
}
#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 @@
* 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 @@
* 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