[PATCH RT 09/30] hrtimer: Dont grab the expiry lock for non-soft hrtimer

[Steven Rostedt]

4.19.94-rt39-rc2 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Julien Grall <julien.grall@xxxxxxx>

[ Upstream commit fd420354bea2f57c11f3de191dffdeea76531e76 ]

Acquiring the lock in hrtimer_grab_expiry_lock() is designed for
sleeping-locks and should not be used with disabled interrupts.
hrtimer_cancel() may invoke hrtimer_grab_expiry_lock() also for locks
which expire in hard-IRQ context.

Let hrtimer_cancel() invoke hrtimer_grab_expiry_lock() only for locks
which expire in softirq context.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
[bigeasy: rewrite changelog]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
 kernel/time/hrtimer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index d6026c170c2d..49d20fe8570f 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -943,7 +943,7 @@ void hrtimer_grab_expiry_lock(const struct hrtimer *timer)
 {
 	struct hrtimer_clock_base *base = READ_ONCE(timer->base);
 
-	if (base && base->cpu_base) {
+	if (timer->is_soft && base && base->cpu_base) {
 		spin_lock(&base->cpu_base->softirq_expiry_lock);
 		spin_unlock(&base->cpu_base->softirq_expiry_lock);
 	}
-- 
2.24.1