On Mon, 2018-03-19 at 19:06 +0100, Greg Kroah-Hartman wrote:
> 4.4-stable review patch. If anyone has any objections, please let me know.
>
> ------------------
>
> From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
>
>
> [ Upstream commit a8b149d32b663c1a4105273295184b78f53d33cf ]
[...]
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -551,6 +551,8 @@ static int cpufreq_parse_governor(char *
> *governor = t;
> err = 0;
> }
> + if (t && !try_module_get(t->owner))
> + t = NULL;
This won't work because t is dead after this point. The fix appears to
depend on:
commit 045149e6a22119e5bf0d16a0b24a4173a2abb71d
Author: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Date: Thu Nov 23 01:23:16 2017 +0100
cpufreq: Clean up cpufreq_parse_governor()
which moves the assignment to *governor further down.
Ben.
> mutex_unlock(&cpufreq_governor_mutex);
> }
> @@ -669,6 +671,10 @@ static ssize_t store_scaling_governor(st
> return -EINVAL;
>
> ret = cpufreq_set_policy(policy, &new_policy);
> +
> + if (new_policy.governor)
> + module_put(new_policy.governor->owner);
> +
> return ret ? ret : count;
> }
>
--
Ben Hutchings
Software Developer, Codethink Ltd.