blkdev.h integer overflows

[William Lee Irwin III]

blk_max_pfn is an unsigned long; left shifting by PAGE_SHIFT means
it may overflow.

Bill

diff -urpN mm2-2.5.52-1/include/linux/blkdev.h blk-2.5.52-1/include/linux/blkdev.h
--- mm2-2.5.52-1/include/linux/blkdev.h	2002-12-18 22:01:01.000000000 -0800
+++ blk-2.5.52-1/include/linux/blkdev.h	2002-12-23 08:06:25.000000000 -0800
@@ -297,8 +297,8 @@ extern unsigned long blk_max_low_pfn, bl
  * BLK_BOUNCE_ANY	: don't bounce anything
  * BLK_BOUNCE_ISA	: bounce pages above ISA DMA boundary
  */
-#define BLK_BOUNCE_HIGH		(blk_max_low_pfn << PAGE_SHIFT)
-#define BLK_BOUNCE_ANY		(blk_max_pfn << PAGE_SHIFT)
+#define BLK_BOUNCE_HIGH		((u64)blk_max_low_pfn << PAGE_SHIFT)
+#define BLK_BOUNCE_ANY		((u64)blk_max_pfn << PAGE_SHIFT)
 #define BLK_BOUNCE_ISA		(ISA_DMA_THRESHOLD)
 
 extern int init_emergency_isa_pool(void);