| From | lizf@kernel ... | Subject | [PATCH 3.4 70/92] clocksource: Fix abs() usage w/ 64bit values | Date | Mon, 18 Apr 2016 18:46:15 +0800 |
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From: John Stultz <john.stultz@linaro.org>
3.4.112-rc1 review patch. If anyone has any objections, please let me know.
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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(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index c958338..b3f5407 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -291,7 +291,7 @@ static void clocksource_watchdog(unsigned long data) 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; } -- 1.9.1
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