This commit adds irq, NMI, and softirq context checks to the
rcu_torture_timer() function.  Just because you are paranoid does not
mean that they are not out to get you...  ;-)

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcutorture.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index d00b043823aef..63053031ade21 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -2454,6 +2454,9 @@ static DEFINE_TORTURE_RANDOM_PERCPU(rcu_torture_timer_rand);
  */
 static void rcu_torture_timer(struct timer_list *unused)
 {
+	WARN_ON_ONCE(!in_serving_softirq());
+	WARN_ON_ONCE(in_hardirq());
+	WARN_ON_ONCE(in_nmi());
 	atomic_long_inc(&n_rcu_torture_timers);
 	(void)rcu_torture_one_read(this_cpu_ptr(&rcu_torture_timer_rand), -1);
 
-- 
2.40.1