_find_device_opp() should be called with rcu-read lock or dev_opp_list_lock held. Add the opp_rcu_lockdep_assert() check to make sure caller have taken appropriate locks.
Fix comment over the routine as well.
Cc: 4.3 stable@vger.kernel.org # 4.3 Suggested-by: Stephen Boyd sboyd@codeaurora.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/base/power/opp/core.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 7a395f5ba5f9..5e4b1d82b2f8 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -81,14 +81,18 @@ static struct device_opp *_managed_opp(const struct device_node *np) * Return: pointer to 'struct device_opp' if found, otherwise -ENODEV or * -EINVAL based on type of error. * - * Locking: This function must be called under rcu_read_lock(). device_opp - * is a RCU protected pointer. This means that device_opp is valid as long - * as we are under RCU lock. + * Locking: For readers, this function must be called under rcu_read_lock(). + * device_opp is a RCU protected pointer, which means that device_opp is valid + * as long as we are under RCU lock. + * + * For Writers, this function must be called with dev_opp_list_lock held. */ struct device_opp *_find_device_opp(struct device *dev) { struct device_opp *dev_opp;
+ opp_rcu_lockdep_assert(); + if (IS_ERR_OR_NULL(dev)) { pr_err("%s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL);