[PATCH 2/2] sched/nohz: fix overflow error in scheduler_tick_max_deferment()
Kevin Hilman
khilman at linaro.org
Mon Sep 16 18:43:49 EDT 2013
The conversion of the max deferment from usecs to nsecs can easily
overflow on platforms where a long is 32-bits. To fix, cast the usecs
value to u64 before multiplying by NSECS_PER_USEC.
This was discovered on 32-bit ARM platform when extending the max
deferment value.
Cc: Frederic Weisbecker <fweisbec at gmail.com>
Signed-off-by: Kevin Hilman <khilman at linaro.org>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4b1fe3e..3d7c80e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2203,7 +2203,7 @@ u64 scheduler_tick_max_deferment(void)
if (time_before_eq(next, now))
return 0;
- return jiffies_to_usecs(next - now) * NSEC_PER_USEC;
+ return (u64)jiffies_to_usecs(next - now) * NSEC_PER_USEC;
}
static __init int sched_nohz_full_init_debug(void)
--
1.8.3
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