[PATCH 13/15] thermal: sysfs: lock cdev while accessing cur_state

From: Eduardo Valentin
Date: Tue May 31 2016 - 02:33:54 EST


Serialized calls to cdev->ops in user facing
sysfs handlers thermal_cooling_device_cur_state_show()
and thermal_cooling_device_cur_state_store().

Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Eduardo Valentin <edubezval@xxxxxxxxx>
---
drivers/thermal/thermal_sysfs.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 3eaa081..ab78e08 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -715,7 +715,9 @@ thermal_cooling_device_cur_state_show(struct device *dev,
unsigned long state;
int ret;

+ mutex_lock(&cdev->lock);
ret = cdev->ops->get_cur_state(cdev, &state);
+ mutex_unlock(&cdev->lock);
if (ret)
return ret;
return sprintf(buf, "%ld\n", state);
@@ -736,7 +738,9 @@ thermal_cooling_device_cur_state_store(struct device *dev,
if ((long)state < 0)
return -EINVAL;

+ mutex_lock(&cdev->lock);
result = cdev->ops->set_cur_state(cdev, state);
+ mutex_unlock(&cdev->lock);
if (result)
return result;
return count;
--
2.1.4