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>

include/linux/page-flags.h

@@ -479,7 +479,7 @@ static inline void ClearPageCompound(struct page *page)
 }
 #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 ClearPageSlabPfmemalloc(struct page *page)
 }
 
 #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 ClearPageSlabPfmemalloc(struct page *page)
  * 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 ClearPageSlabPfmemalloc(struct page *page)
  * 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