| From 67dfae0cd72fec5cd158b6e5fb1647b7dbe0834c Mon Sep 17 00:00:00 2001 |
| From: John Stultz <john.stultz@linaro.org> |
| Date: Mon, 14 Sep 2015 18:05:20 -0700 |
| Subject: clocksource: Fix abs() usage w/ 64bit values |
| |
| commit 67dfae0cd72fec5cd158b6e5fb1647b7dbe0834c upstream. |
| |
| This patch fixes one cases where abs() was being used with 64-bit |
| nanosecond values, where the result may be capped at 32-bits. |
| |
| This potentially could cause watchdog false negatives on 32-bit |
| systems, so this patch addresses the issue by using abs64(). |
| |
| Signed-off-by: John Stultz <john.stultz@linaro.org> |
| Cc: Prarit Bhargava <prarit@redhat.com> |
| Cc: Richard Cochran <richardcochran@gmail.com> |
| Cc: Ingo Molnar <mingo@kernel.org> |
| Link: http://lkml.kernel.org/r/1442279124-7309-2-git-send-email-john.stultz@linaro.org |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| [lizf: Backported to 3.4: adjust context] |
| Signed-off-by: Zefan Li <lizefan@huawei.com> |
| --- |
| kernel/time/clocksource.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/kernel/time/clocksource.c |
| +++ b/kernel/time/clocksource.c |
| @@ -291,7 +291,7 @@ static void clocksource_watchdog(unsigne |
| continue; |
| |
| /* Check the deviation from the watchdog clocksource. */ |
| - if ((abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD)) { |
| + if ((abs64(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD)) { |
| clocksource_unstable(cs, cs_nsec - wd_nsec); |
| continue; |
| } |
