Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH] posix-cpu-timers: Fix spuriously armed 0-value itimer | Date | Mon, 13 Sep 2021 16:53:32 +0200 |
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Resetting/stopping an itimer eventually leads to it being reprogrammed with an actual "0" value. As a result the itimer expires on the next tick, triggering an unexpected signal.
To fix this, make sure that struct signal_struct::it[CPUCLOCK_PROF/VIRT]::expires is set to 0 when setitimer() passes a 0 it_value, indicating that the timer must stop.
Reported-by: Victor Stinner <vstinner@redhat.com> Fixes: 406dd42bd1ba ("posix-cpu-timers: Force next expiration recalc after itimer reset") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> --- kernel/time/posix-cpu-timers.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index ee736861b18f..643d412ac623 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1404,7 +1404,8 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clkid, } } - *newval += now; + if (*newval) + *newval += now; } /* -- 2.25.1
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