linux-kernel - [PATCH RT] posix-timers: Unlock expiry lock in the early return

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Message-ID: <20190923160141.oqsv7vwhw5pof6f2@linutronix.de>
Date:   Mon, 23 Sep 2019 18:01:41 +0200
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     linux-rt-users <linux-rt-users@...r.kernel.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH RT] posix-timers: Unlock expiry lock in the early return

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 <lkp@...el.com>
Reported-by: Dan Carpenter <dan.carpenter@...cle.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
---
 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 20cd92a8b9785..a045813c37021 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -1167,8 +1167,10 @@ 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
-- 
2.23.0