Messages in this thread Patch in this message | | | From | Ulrich Obergfell <> | Subject | [PATCH 4/4] watchdog: fix race between proc_watchdog_thresh() and watchdog_timer_fn() | Date | Tue, 3 Nov 2015 16:21:01 +0100 |
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Theoretically it is possible that the watchdog timer expires right at the time when a user sets 'watchdog_thresh' to zero (note: this disables the lockup detectors). In this scenario, the is_softlockup() function - which is called by the timer - could produce a false positive.
Fix this by checking the current value of 'watchdog_thresh'.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com> --- kernel/watchdog.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 84c4744..18f34cf 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -289,7 +289,7 @@ static int is_softlockup(unsigned long touch_ts) { unsigned long now = get_timestamp(); - if (watchdog_enabled & SOFT_WATCHDOG_ENABLED) { + if ((watchdog_enabled & SOFT_WATCHDOG_ENABLED) && watchdog_thresh){ /* Warn about unreasonable delays. */ if (time_after(now, touch_ts + get_softlockup_thresh())) return now - touch_ts; -- 1.7.11.7
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