Re: [RFC PATCH 08/19] cpufreq: fix warning for cpufreq_init_policy unlocked access to cpufreq_governor_list

From: Viresh Kumar
Date: Tue Jan 12 2016 - 05:09:58 EST


On 11-01-16, 17:35, Juri Lelli wrote:
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 7dae7f3..d065435 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -969,6 +969,7 @@ static int cpufreq_init_policy(struct cpufreq_policy *policy)
>
> memcpy(&new_policy, policy, sizeof(*policy));
>
> + mutex_lock(&cpufreq_governor_mutex);
> /* Update governor of new_policy to the governor used before hotplug */
> gov = find_governor(policy->last_governor);

You should take the lock within find_governor() instead, i.e. around
the while loop.

> if (gov)
> @@ -976,6 +977,7 @@ static int cpufreq_init_policy(struct cpufreq_policy *policy)
> policy->governor->name, policy->cpu);
> else
> gov = CPUFREQ_DEFAULT_GOVERNOR;
> + mutex_unlock(&cpufreq_governor_mutex);
>
> new_policy.governor = gov;
>
> --
> 2.2.2

--
viresh