From: Sebastian Andrzej Siewior Date: Mon, 16 Sep 2019 12:33:59 +0200 Subject: [PATCH 296/351] posix-timers: Unlock expiry lock in the early return Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=c607c24d4378ebe9be9bb641703e00d28eca3c75 [ Upstream commit 356a2781375ec58521a9bc3f500488745990c242 ] Patch ("posix-timers: Add expiry lock") acquired a lock in run_posix_cpu_timers() but didn't drop the lock in the early return. Unlock the lock in the early return path. Reported-by: kbuild test robot Reported-by: Dan Carpenter Reviewed-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- kernel/time/posix-cpu-timers.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 54632ed51c65..b9e4ccbb60f3 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1175,8 +1175,10 @@ static void __run_posix_cpu_timers(struct task_struct *tsk) expiry_lock = this_cpu_ptr(&cpu_timer_expiry_lock); spin_lock(expiry_lock); - if (!lock_task_sighand(tsk, &flags)) + if (!lock_task_sighand(tsk, &flags)) { + spin_unlock(expiry_lock); return; + } /* * Here we take off tsk->signal->cpu_timers[N] and * tsk->cpu_timers[N] all the timers that are firing, and