From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Thu, 20 Jul 2017 22:27:32 +0000 (-0700)
Subject: rcutorture: Invoke call_rcu() from timer handler
X-Git-Tag: v4.14-rc1~174^2^2^7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f34c8585ed70f0f9b5ff9cf59c0dd533cddb975f;p=thirdparty%2Fkernel%2Flinux.git

rcutorture: Invoke call_rcu() from timer handler

The Linux kernel invokes call_rcu() from various interrupt/softirq
handlers, but rcutorture does not.  This commit therefore adds this
behavior to rcutorture's repertoire.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 6e3f644280eec..0efd69b2fb8c0 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1080,6 +1080,11 @@ rcu_torture_fakewriter(void *arg)
 	return 0;
 }
 
+static void rcu_torture_timer_cb(struct rcu_head *rhp)
+{
+	kfree(rhp);
+}
+
 /*
  * RCU torture reader from timer handler.  Dereferences rcu_torture_current,
  * incrementing the corresponding element of the pipeline array.  The
@@ -1142,6 +1147,14 @@ static void rcu_torture_timer(unsigned long unused)
 	__this_cpu_inc(rcu_torture_batch[completed]);
 	preempt_enable();
 	cur_ops->readunlock(idx);
+
+	/* Test call_rcu() invocation from interrupt handler. */
+	if (cur_ops->call) {
+		struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT);
+
+		if (rhp)
+			cur_ops->call(rhp, rcu_torture_timer_cb);
+	}
 }
 
 /*