[PATCH 11/15] thermal: sysfs: lock cdev while accessing type

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

Serialized data access to cdev->type in user facing
sysfs handler thermal_cooling_device_type_show().

The existing cdev lock is used. Updating comment
on the lock definition.

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 | 7 ++++++-
include/linux/thermal.h | 2 +-
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 86a77cd..044090a 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -682,8 +682,13 @@ thermal_cooling_device_type_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
+ char *type;
+
+ mutex_lock(&cdev->lock);
+ type = cdev->type;
+ mutex_unlock(&cdev->lock);

- return sprintf(buf, "%s\n", cdev->type);
+ return sprintf(buf, "%s\n", type);
}

static ssize_t
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index fa2c2be..7b2c014 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -137,7 +137,7 @@ struct thermal_cooling_device {
void *devdata;
const struct thermal_cooling_device_ops *ops;
bool updated; /* true if the cooling device does not need update */
- struct mutex lock; /* protect thermal_instances list */
+ struct mutex lock; /* protect thermal_cooling_device */
struct list_head thermal_instances;
struct list_head node;
};
--
2.1.4