linux-kernel - [PATCH 2/2] posix-timers: Use spin_lock_irq() in itimer

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Date:   Fri, 21 Jun 2019 16:36:43 +0200
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     linux-kernel@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Subject: [PATCH 2/2] posix-timers: Use spin_lock_irq() in itimer_delete()

itimer_delete() uses spin_lock_irqsave() to obtain a `flags' variable
which can then be passed to unlock_timer(). It uses already spin_lock
locking for the structure instead of lock_timer() because it has a timer
which can not be removed by others at this point. The cleanup is always
performed with enabled interrupts.

Use spin_lock_irq() / spin_unlock_irq() so the `flags' variable can be
removed.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
---
 kernel/time/posix-timers.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index caa63e58e3d88..d7f2d91acdac1 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -980,18 +980,16 @@ SYSCALL_DEFINE1(timer_delete, timer_t, timer_id)
  */
 static void itimer_delete(struct k_itimer *timer)
 {
-	unsigned long flags;
-
 retry_delete:
-	spin_lock_irqsave(&timer->it_lock, flags);
+	spin_lock_irq(&timer->it_lock);
 
 	if (timer_delete_hook(timer) == TIMER_RETRY) {
-		unlock_timer(timer, flags);
+		spin_unlock_irq(&timer->it_lock);
 		goto retry_delete;
 	}
 	list_del(&timer->list);
 
-	unlock_timer(timer, flags);
+	spin_unlock_irq(&timer->it_lock);
 	release_posix_timer(timer, IT_ID_SET);
 }
 
-- 
2.20.1