Re: [PATCH] thermal: lock the thermal zone when switching governors

["Javi Merino" <javi.merino@arm.com>]

Ping

On Tue, Nov 25, 2014 at 04:00:33PM +0000, Javi Merino wrote:
> Currently, userspace can request a governor change while the governor
> itself is running.  Grab the thermal zone lock when changing the
> governor to prevent this race.
> 
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Eduardo Valentin <edubezval@gmail.com>
> Signed-off-by: Javi Merino <javi.merino@arm.com>
> ---
>  drivers/thermal/thermal_core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 43b90709585f..c1901961f8c0 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -757,6 +757,7 @@ policy_store(struct device *dev, struct device_attribute *attr,
>  	snprintf(name, sizeof(name), "%s", buf);
>  
>  	mutex_lock(&thermal_governor_lock);
> +	mutex_lock(&tz->lock);
>  
>  	gov = __find_governor(strim(name));
>  	if (!gov)
> @@ -766,6 +767,7 @@ policy_store(struct device *dev, struct device_attribute *attr,
>  	ret = count;
>  
>  exit:
> +	mutex_unlock(&tz->lock);
>  	mutex_unlock(&thermal_governor_lock);
>  	return ret;
>  }
> -- 
> 1.9.1
>