PM / QoS: Improve sysfs pm_qos_latency_tolerance validation
Negative values are special. Don't let users write them directly.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index a7b4679..33b4b90 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -263,7 +263,11 @@ static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
s32 value;
int ret;
- if (kstrtos32(buf, 0, &value)) {
+ if (kstrtos32(buf, 0, &value) == 0) {
+ /* Users can't write negative values directly */
+ if (value < 0)
+ return -EINVAL;
+ } else {
if (!strcmp(buf, "auto") || !strcmp(buf, "auto\n"))
value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))