diff options
| author | Michal Nazarewicz | 2013-11-10 20:42:01 +0100 |
|---|---|---|
| committer | Ingo Molnar | 2013-11-13 13:33:55 +0100 |
| commit | 85b088e934b9943322bfe37077289ae60f1b3414 (patch) | |
| tree | 2ad7a5376ecf31e10604794f98c8e8c63e42aeca | |
| parent | 911b2898b3c9fe0048e9485ad1629ed4fce330fd (diff) | |
sched/fair: Avoid integer overflow
sa->runnable_avg_sum is of type u32 but after shifting it by NICE_0_SHIFT
bits it is promoted to u64. This of course makes no sense, since the
result will never be more then 32-bit long. Casting sa->runnable_avg_sum
to u64 before it is shifted, fixes this problem.
Reviewed-by: Ben Segall <bsegall@google.com>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1384112521-25177-1-git-send-email-mpn@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | kernel/sched/fair.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 201be782b5b3..e8b652ebe027 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2178,7 +2178,7 @@ static inline void __update_tg_runnable_avg(struct sched_avg *sa, long contrib; /* The fraction of a cpu used by this cfs_rq */ - contrib = div_u64(sa->runnable_avg_sum << NICE_0_SHIFT, + contrib = div_u64((u64)sa->runnable_avg_sum << NICE_0_SHIFT, sa->runnable_avg_period + 1); contrib -= cfs_rq->tg_runnable_contrib; |