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| author | Frederic Weisbecker <frederic@kernel.org> | 2021-09-13 16:53:32 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-09-23 11:53:51 +0200 |
| commit | 8cd9da85d2bd87ce889043e7b1735723dd10eb89 (patch) | |
| tree | 6c3861d6c7546018bb4bae808aea793a3d95287b /kernel/time | |
| parent | e4e737bb5c170df6135a127739a9e6148ee3da82 (diff) | |
| download | linux-8cd9da85d2bd87ce889043e7b1735723dd10eb89.tar.gz linux-8cd9da85d2bd87ce889043e7b1735723dd10eb89.tar.bz2 linux-8cd9da85d2bd87ce889043e7b1735723dd10eb89.zip | |
posix-cpu-timers: Prevent spuriously armed 0-value itimer
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.
Fixes: 406dd42bd1ba ("posix-cpu-timers: Force next expiration recalc after itimer reset")
Reported-by: Victor Stinner <vstinner@redhat.com>
Reported-by: Chris Hixon <linux-kernel-bugs@hixontech.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210913145332.232023-1-frederic@kernel.org
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/posix-cpu-timers.c | 3 |
1 files changed, 2 insertions, 1 deletions
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; } /* |