From mboxrd@z Thu Jan 1 00:00:00 1970 From: Axel Lin Date: Thu, 31 Jul 2014 07:30:51 +0000 Subject: [lm-sensors] [PATCH v2 1/2] hwmon: (lm77) Prevent overflow problem when writing large limits Message-Id: <1406791851.7637.1.camel@phoenix> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lm-sensors@vger.kernel.org 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 --- 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@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors