diff --git a/[refs] b/[refs]
index 489d87e2fba5..c69da241b0e1 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 238c1a78c957f3dc7cb848b161dcf4805793ed56
+refs/heads/master: 84bb671dc46d77d665d2b5e74539e81b2129bb3e
diff --git a/trunk/kernel/perf_event.c b/trunk/kernel/perf_event.c
index 31d6afe92594..ff86c558af4c 100644
--- a/trunk/kernel/perf_event.c
+++ b/trunk/kernel/perf_event.c
@@ -1507,6 +1507,9 @@ do {					\
 		divisor = nsec * frequency;
 	}
 
+	if (!divisor)
+		return dividend;
+
 	return div64_u64(dividend, divisor);
 }
 
@@ -1529,7 +1532,7 @@ static int perf_event_start(struct perf_event *event)
 static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	u64 period, sample_period;
+	s64 period, sample_period;
 	s64 delta;
 
 	period = perf_calculate_period(event, nsec, count);