kyber: fix integer overflow of latency targets on 32-bit

NSEC_PER_SEC has type long, so 5 * NSEC_PER_SEC is calculated as a long. However, 5 seconds is 5,000,000,000 nanoseconds, which overflows a 32-bit long. Make sure all of the targets are calculated as 64-bit values. Fixes: 6e25cb0 ("kyber: implement improved heuristics") Reported-by: Stephen Rothwell <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
kawasaki · Sep 28, 2018 · f0a0cdd · f0a0cdd
1 parent e982c4d
commit f0a0cdd
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
@@ -79,9 +79,9 @@ static const unsigned int kyber_depth[] = {
  * Default latency targets for each scheduling domain.
  */
 static const u64 kyber_latency_targets[] = {
-	[KYBER_READ] = 2 * NSEC_PER_MSEC,
-	[KYBER_WRITE] = 10 * NSEC_PER_MSEC,
-	[KYBER_DISCARD] = 5 * NSEC_PER_SEC,
+	[KYBER_READ] = 2ULL * NSEC_PER_MSEC,
+	[KYBER_WRITE] = 10ULL * NSEC_PER_MSEC,
+	[KYBER_DISCARD] = 5ULL * NSEC_PER_SEC,
 };
 
 /*