All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] devfreq: replace sscanf with kstrtol
@ 2017-08-04  3:57 gsantosh
  2017-08-04  4:23 ` gsantosh
  2017-08-04 15:12 ` Chanwoo Choi
  0 siblings, 2 replies; 6+ messages in thread
From: gsantosh @ 2017-08-04  3:57 UTC (permalink / raw)
  To: MyungJoo Ham, Kyungmin Park, linux-pm, linux-kernel,
	Rafael J. Wysocki, gsantosh

Hi,

Adding error checks to devfreq userspace governor, the current 
implementation results in setting wrong
frequency when sscanf returns error.


 From 12e0a347addd70529b2c378299b27b65f0766f99 Mon Sep 17 00:00:00 2001
 From: Santosh Mardi <gsantosh@codeaurora.org>
Date: Tue, 25 Jul 2017 18:47:11 +0530
Subject: [PATCH] devfreq: replace sscanf with kstrtol

store_freq function of devfreq userspace governor
executes further, even if error is returned from sscanf,
this will result in setting up wrong frequency value.

The usage for the sscanf is only for single variable so
replace sscanf with kstrtol along with error check to
bail out if any error is returned.

Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>
---
  drivers/devfreq/governor_userspace.c | 5 ++++-
  1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/devfreq/governor_userspace.c 
b/drivers/devfreq/governor_userspace.c
index 77028c2..a84796d 100644
--- a/drivers/devfreq/governor_userspace.c
+++ b/drivers/devfreq/governor_userspace.c
@@ -53,12 +53,15 @@ static ssize_t store_freq(struct device *dev, struct 
device_attribute *attr,
  	mutex_lock(&devfreq->lock);
  	data = devfreq->data;

-	sscanf(buf, "%lu", &wanted);
+	err = kstrtol(buf, 0, &wanted);
+	if (err < 0)
+		goto out;
  	data->user_frequency = wanted;
  	data->valid = true;
  	err = update_devfreq(devfreq);
  	if (err == 0)
  		err = count;
+out:
  	mutex_unlock(&devfreq->lock);
  	return err;
  }
-- 

Regards,
Santosh M G.
Qualcomm Innovation Center

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2017-08-07 12:26 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-08-04  3:57 [PATCH] devfreq: replace sscanf with kstrtol gsantosh
2017-08-04  4:23 ` gsantosh
2017-08-04 15:12 ` Chanwoo Choi
2017-08-07  4:47   ` gsantosh
2017-08-07  5:25     ` Chanwoo Choi
2017-08-07 12:26       ` gsantosh

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.