lkml.org 
[lkml]   [2013]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] sched/nohz: fix overflow error in scheduler_tick_max_deferment()
Date
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@gmail.com>
Signed-off-by: Kevin Hilman <khilman@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


\
 
 \ /
  Last update: 2013-09-17 01:01    [W:8.372 / U:0.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site