fix 2.4 BLK_BOUNCE_ANY

[William Lee Irwin III]

The bitshift defining BLK_BOUNCE_ANY can overflow. This patch casts
to u64 before shifting there as well as in BLK_BOUNCE_HIGH to ensure
integer overflow does not occur.

Originally discovered by Zwane Mwaikambo during pgcl development,
submitted by me to mainline to 2.6, and already included in 2.6.


-- wli


===== include/linux/blkdev.h 1.25 vs edited =====
--- 1.25/include/linux/blkdev.h	Wed Jul 16 13:20:46 2003
+++ edited/include/linux/blkdev.h	Mon Dec  8 13:44:17 2003
@@ -176,8 +176,8 @@
 
 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 
-#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)
 
 extern void blk_queue_bounce_limit(request_queue_t *, u64);
 
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/