[PATCH 02/15] thermal: sysfs: lock tz while on access to mode properties

Eduardo Valentin
2016-05-31T06:32:05Z

Serialized calls to tz.ops in user facing
sysfs handler mode_show() and mode_store().

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
---
drivers/thermal/thermal_sysfs.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index ee983ca..1db2406 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -62,7 +62,9 @@ mode_show(struct device *dev, struct device_attribute *attr, char *buf)
if (!tz->ops->get_mode)
return -EPERM;

+ mutex_lock(&tz->lock);
result = tz->ops->get_mode(tz, &mode);
+ mutex_unlock(&tz->lock);
if (result)
return result;

@@ -75,17 +77,22 @@ mode_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct thermal_zone_device *tz = to_thermal_zone(dev);
+ enum thermal_device_mode mode = THERMAL_DEVICE_DISABLED;
int result;

if (!tz->ops->set_mode)
return -EPERM;

if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
- result = tz->ops->set_mode(tz, THERMAL_DEVICE_ENABLED);
+ mode = THERMAL_DEVICE_ENABLED;
else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
- result = tz->ops->set_mode(tz, THERMAL_DEVICE_DISABLED);
+ mode = THERMAL_DEVICE_DISABLED;
else
- result = -EINVAL;
+ return -EINVAL;
+
+ mutex_lock(&tz->lock);
+ result = tz->ops->set_mode(tz, mode);
+ mutex_unlock(&tz->lock);

if (result)
return result;
--
2.1.4