[002/155] kthread: mark timer used by delayed kthread works as IRQ safe

Commit Message

Andrew Morton April 2, 2020, 4:02 a.m. UTC

From: Petr Mladek <[e-mail]>
Subject: kthread: mark timer used by delayed kthread works as IRQ safe

The timer used by delayed kthread works are IRQ safe because the used
kthread_delayed_work_timer_fn() is IRQ safe.

It is properly marked when initialized by KTHREAD_DELAYED_WORK_INIT(). 
But TIMER_IRQSAFE flag is missing when initialized by
kthread_init_delayed_work().

The missing flag might trigger invalid warning from del_timer_sync() when
kthread_mod_delayed_work() is called with interrupts disabled.

This patch is result of a discussion about using the API, see
https://lkml.kernel.org/r/[e-mail]

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Petr Mladek <[e-mail]>
Reported-by: Grygorii Strashko <[e-mail]>
Tested-by: Grygorii Strashko <[e-mail]>
Acked-by: Tejun Heo <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 include/linux/kthread.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch

--- a/include/linux/kthread.h~kthread-mark-timer-used-by-delayed-kthread-works-as-irq-safe
+++ a/include/linux/kthread.h
@@ -165,7 +165,8 @@  extern void __kthread_init_worker(struct
 	do {								\
 		kthread_init_work(&(dwork)->work, (fn));		\
 		timer_setup(&(dwork)->timer,				\
-			     kthread_delayed_work_timer_fn, 0);		\
+			     kthread_delayed_work_timer_fn,		\
+			     TIMER_IRQSAFE);				\
 	} while (0)
 
 int kthread_worker_fn(void *worker_ptr);