[ 016/187] bql: Fix POSDIFF() to integer overflow aware.

[Greg Kroah-Hartman]

From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Hiroaki SHIMODA <shimoda.hiroaki@xxxxxxxxx>

[ Upstream commit 0cfd32b736ae0c36b42697584811042726c07cba ]

POSDIFF() fails to take into account integer overflow case.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@xxxxxxxxx>
Cc: Tom Herbert <therbert@xxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: Denys Fedoryshchenko <denys@xxxxxxxxxxx>
Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 lib/dynamic_queue_limits.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/lib/dynamic_queue_limits.c
+++ b/lib/dynamic_queue_limits.c
@@ -10,7 +10,7 @@
 #include <linux/jiffies.h>
 #include <linux/dynamic_queue_limits.h>
 
-#define POSDIFF(A, B) ((A) > (B) ? (A) - (B) : 0)
+#define POSDIFF(A, B) ((int)((A) - (B)) > 0 ? (A) - (B) : 0)
 
 /* Records completed count and recalculates the queue limit */
 void dql_completed(struct dql *dql, unsigned int count)


--
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/