[PATCH] rcutorture: Make rcutorture support srcu double call test

[Zqiang]

This commit also allows rcutorture to support srcu double call test
with CONFIG_DEBUG_OBJECTS_RCU_HEAD option enabled. since the spinlock
will be called in call_srcu(), in RT-kernel, the spinlock is sleepable,
therefore remove disable-irq and disable-preempt protection.

Signed-off-by: Zqiang <qiang.zhang1211@xxxxxxxxx>
---
 kernel/rcu/rcutorture.c | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 3f9c3766f52b..6571a69142f8 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -388,6 +388,7 @@ struct rcu_torture_ops {
 	int extendables;
 	int slow_gps;
 	int no_pi_lock;
+	int debug_objects;
 	const char *name;
 };
 
@@ -573,6 +574,7 @@ static struct rcu_torture_ops rcu_ops = {
 	.irq_capable		= 1,
 	.can_boost		= IS_ENABLED(CONFIG_RCU_BOOST),
 	.extendables		= RCUTORTURE_MAX_EXTEND,
+	.debug_objects		= 1,
 	.name			= "rcu"
 };
 
@@ -743,6 +745,7 @@ static struct rcu_torture_ops srcu_ops = {
 	.cbflood_max	= 50000,
 	.irq_capable	= 1,
 	.no_pi_lock	= IS_ENABLED(CONFIG_TINY_SRCU),
+	.debug_objects	= 1,
 	.name		= "srcu"
 };
 
@@ -782,6 +785,7 @@ static struct rcu_torture_ops srcud_ops = {
 	.cbflood_max	= 50000,
 	.irq_capable	= 1,
 	.no_pi_lock	= IS_ENABLED(CONFIG_TINY_SRCU),
+	.debug_objects	= 1,
 	.name		= "srcud"
 };
 
@@ -3481,35 +3485,37 @@ static void rcu_test_debug_objects(void)
 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
 	struct rcu_head rh1;
 	struct rcu_head rh2;
+	int idx;
+
+	if (!cur_ops->debug_objects || !cur_ops->call ||
+			!cur_ops->cb_barrier)
+		return;
+
 	struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
 
 	init_rcu_head_on_stack(&rh1);
 	init_rcu_head_on_stack(&rh2);
-	pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME);
+	pr_alert("%s: WARN: Duplicate call_%s() test starting.\n", KBUILD_MODNAME, cur_ops->name);
 
 	/* Try to queue the rh2 pair of callbacks for the same grace period. */
-	preempt_disable(); /* Prevent preemption from interrupting test. */
-	rcu_read_lock(); /* Make it impossible to finish a grace period. */
-	call_rcu_hurry(&rh1, rcu_torture_leak_cb); /* Start grace period. */
-	local_irq_disable(); /* Make it harder to start a new grace period. */
-	call_rcu_hurry(&rh2, rcu_torture_leak_cb);
-	call_rcu_hurry(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
+	idx = cur_ops->readlock(); /* Make it impossible to finish a grace period. */
+	cur_ops->call(&rh1, rcu_torture_leak_cb); /* Start grace period. */
+	cur_ops->call(&rh2, rcu_torture_leak_cb);
+	cur_ops->call(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
 	if (rhp) {
-		call_rcu_hurry(rhp, rcu_torture_leak_cb);
-		call_rcu_hurry(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
+		cur_ops->call(rhp, rcu_torture_leak_cb);
+		cur_ops->call(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
 	}
-	local_irq_enable();
-	rcu_read_unlock();
-	preempt_enable();
+	cur_ops->readunlock(idx);
 
 	/* Wait for them all to get done so we can safely return. */
-	rcu_barrier();
-	pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
+	cur_ops->cb_barrier();
+	pr_alert("%s: WARN: Duplicate call_%s() test complete.\n", KBUILD_MODNAME, cur_ops->name);
 	destroy_rcu_head_on_stack(&rh1);
 	destroy_rcu_head_on_stack(&rh2);
 	kfree(rhp);
 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
-	pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
+	pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_%s()\n", KBUILD_MODNAME, cur_ops->name);
 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
 }
 
-- 
2.17.1