[PATCH v2 1/2] hwmon: (lm77) Prevent overflow problem when writing large limits

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On platforms with sizeof(int) < sizeof(long), writing a temperature
limit larger than MAXINT will result in unpredictable limit values
written to the chip.
Clamp the input values to the supported limits first to fix the problem.

Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
---
 drivers/hwmon/lm77.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/lm77.c b/drivers/hwmon/lm77.c
index 5ceb443..72a02b0 100644
--- a/drivers/hwmon/lm77.c
+++ b/drivers/hwmon/lm77.c
@@ -80,8 +80,7 @@ struct lm77_data {
  */
 static inline s16 LM77_TEMP_TO_REG(int temp)
 {
-	int ntemp = clamp_val(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
-	return (ntemp / 500) * 8;
+	return (temp / 500) * 8;
 }
 
 static inline int LM77_TEMP_FROM_REG(s16 reg)
@@ -176,7 +175,7 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 		return err;
 
 	mutex_lock(&data->update_lock);
-	data->temp[nr] = val;
+	data->temp[nr] = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX);
 	lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val));
 	mutex_unlock(&data->update_lock);
 	return count;
@@ -199,6 +198,7 @@ static ssize_t set_temp_hyst(struct device *dev,
 	if (err)
 		return err;
 
+	val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX);
 	mutex_lock(&data->update_lock);
 	data->temp[t_hyst] = data->temp[t_crit] - val;
 	lm77_write_value(client, LM77_REG_TEMP_HYST,
-- 
1.9.1




_______________________________________________
lm-sensors mailing list
lm-sensors@xxxxxxxxxxxxxx
http://lists.lm-sensors.org/mailman/listinfo/lm-sensors




[Index of Archives]     [Linux Kernel]     [Linux Hardware Monitoring]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]

  Powered by Linux