From: John Stultz <[email protected]> 3.4.112-rc1 review patch. If anyone has any objections, please let me know.
------------------ 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 <[email protected]> Cc: Prarit Bhargava <[email protected]> Cc: Richard Cochran <[email protected]> Cc: Ingo Molnar <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li <[email protected]> --- 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
