[PATCH 1/2] PM / devfreq: fix sscanf handling for writable sysfs entries

[Nishanth Menon]

sscanf returns 0 when an invalid parameter like:
echo -n "a">min_freq
is attempted. Returning back the return result(0) will
cause the command not to return back to command
prompt.

Instead, just return -EINVAL when sscanf does not
return 1.

This is done for min_freq, max_freq and polling_interval

Cc: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
Cc: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: Kevin Hilman <khilman@xxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Signed-off-by: Nishanth Menon <nm@xxxxxx>
---
 drivers/devfreq/devfreq.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index b146d76..9f562ae 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -488,7 +488,7 @@ static ssize_t store_polling_interval(struct device *dev,
 
 	ret = sscanf(buf, "%u", &value);
 	if (ret != 1)
-		goto out;
+		return -EINVAL;
 
 	mutex_lock(&df->lock);
 	df->profile->polling_ms = value;
@@ -529,7 +529,7 @@ static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr,
 
 	ret = sscanf(buf, "%lu", &value);
 	if (ret != 1)
-		goto out;
+		return -EINVAL;
 
 	mutex_lock(&df->lock);
 	max = df->max_freq;
@@ -543,7 +543,6 @@ static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr,
 	ret = count;
 unlock:
 	mutex_unlock(&df->lock);
-out:
 	return ret;
 }
 
@@ -563,7 +562,7 @@ static ssize_t store_max_freq(struct device *dev, struct device_attribute *attr,
 
 	ret = sscanf(buf, "%lu", &value);
 	if (ret != 1)
-		goto out;
+		return -EINVAL;
 
 	mutex_lock(&df->lock);
 	min = df->min_freq;
@@ -577,7 +576,6 @@ static ssize_t store_max_freq(struct device *dev, struct device_attribute *attr,
 	ret = count;
 unlock:
 	mutex_unlock(&df->lock);
-out:
 	return ret;
 }
 
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/