Commit 389baed0 authored by MyungJoo Ham's avatar MyungJoo Ham
Browse files

PM / devfreq: missing rcu_read_lock() added for find_device_opp() 



opp_get_notifier() uses find_device_opp(), which requires to
held rcu_read_lock. In order to keep the notifier-header
valid, we have added rcu_read_lock().

Reported-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarMyungJoo Ham <myungjoo.ham@samsung.com>
parent 883d588e

drivers/devfreq/devfreq.c

+20 −6
Original line number Diff line number Diff line
@@ -1023,11 +1023,18 @@ struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, 
 */

int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)

{

	struct srcu_notifier_head *nh = opp_get_notifier(dev);

	struct srcu_notifier_head *nh;

	int ret = 0;



	rcu_read_lock();

	nh = opp_get_notifier(dev);

	if (IS_ERR(nh))

		return PTR_ERR(nh);

	return srcu_notifier_chain_register(nh, &devfreq->nb);

		ret = PTR_ERR(nh);

	rcu_read_unlock();

	if (!ret)

		ret = srcu_notifier_chain_register(nh, &devfreq->nb);



	return ret;

}



/**
@@ -1042,11 +1049,18 @@ int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) 
 */

int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)

{

	struct srcu_notifier_head *nh = opp_get_notifier(dev);

	struct srcu_notifier_head *nh;

	int ret = 0;



	rcu_read_lock();

	nh = opp_get_notifier(dev);

	if (IS_ERR(nh))

		return PTR_ERR(nh);

	return srcu_notifier_chain_unregister(nh, &devfreq->nb);

		ret = PTR_ERR(nh);

	rcu_read_unlock();

	if (!ret)

		ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);



	return ret;

}



MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");