RCU needs to check if the current code is running a specific timer
callback, in the middle of other conditions to check the sanity of
RCU-nocb. Provide a helper for that.
Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Cc: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx>
Cc: Neeraj Upadhyay <neeraju@xxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
---
include/linux/timer.h | 2 ++
kernel/time/timer.c | 13 +++++++++++++
2 files changed, 15 insertions(+)
diff --git a/include/linux/timer.h b/include/linux/timer.h
index d10bc7e73b41..c75dbf7d118f 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -192,6 +192,8 @@ extern int try_to_del_timer_sync(struct timer_list *timer);
#define del_singleshot_timer_sync(t) del_timer_sync(t)
+extern bool timer_curr_running(struct timer_list *timer);
+
extern void init_timers(void);
extern void run_local_timers(void);
struct hrtimer;
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index de37e33a868d..9d41e4c4cfd4 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -1242,6 +1242,19 @@ int try_to_del_timer_sync(struct timer_list *timer)
}
EXPORT_SYMBOL(try_to_del_timer_sync);
+bool timer_curr_running(struct timer_list *timer)
+{
+ int i;
+
+ for (i = 0; i < NR_BASES; i++) {
+ struct timer_base *base = this_cpu_ptr(&timer_bases[i]);
+ if (base->running_timer == timer)
+ return true;
+ }
+
+ return false;
+}
+
#ifdef CONFIG_PREEMPT_RT
static __init void timer_base_init_expiry_lock(struct timer_base *base)
{
--
2.25.1
