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| author | MyungJoo Ham <myungjoo.ham@samsung.com> | 2012-11-21 11:04:51 +0100 |
|---|---|---|
| committer | MyungJoo Ham <myungjoo.ham@samsung.com> | 2012-11-26 11:17:46 +0100 |
| commit | 389baed01edd298c9622c6e28de5e7e250c8767d (patch) | |
| tree | b15058d96fe7c10738f9cc4efa083897add5f7ac | |
| parent | PM / devfreq: remove compiler error when a governor is module (diff) | |
| download | linux-389baed01edd298c9622c6e28de5e7e250c8767d.tar.xz linux-389baed01edd298c9622c6e28de5e7e250c8767d.zip | |
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>
| -rw-r--r-- | drivers/devfreq/devfreq.c | 26 |
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>"); |