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authorMyungJoo Ham <myungjoo.ham@samsung.com>2012-11-21 14:04:51 +0400
committerMyungJoo Ham <myungjoo.ham@samsung.com>2012-11-26 14:17:46 +0400
commit389baed01edd298c9622c6e28de5e7e250c8767d (patch)
treeb15058d96fe7c10738f9cc4efa083897add5f7ac /drivers/devfreq
parent883d588e556347c4b3221ac492a8acd8a75e730a (diff)
downloadlinux-389baed01edd298c9622c6e28de5e7e250c8767d.tar.xz
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: Kees Cook <keescook@chromium.org> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Diffstat (limited to 'drivers/devfreq')
-rw-r--r--drivers/devfreq/devfreq.c26
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 45e053e5b139..1a78ad9e1bd0 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -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>");