hwmon: (ntc_thermistor) Avoid math overflow

The ntc thermistor code was doing math whose temporary result might
have overflowed 32-bits.  We need some casts in there to make it safe.

In one example I found:
- pullup_uV: 1800000
- result of iio_read_channel_raw: 3226
- 1800000 * 3226 => 0x15a1cbc80

Signed-off-by: Doug Anderson <dianders@chromium.org>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Doug Anderson 2014-02-13 14:39:34 -08:00 committed by Guenter Roeck
parent b28a960c42
commit d3d89c468c
1 changed files with 3 additions and 3 deletions

View File

@ -145,7 +145,7 @@ struct ntc_data {
static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata)
{
struct iio_channel *channel = pdata->chan;
unsigned int result;
s64 result;
int val, ret;
ret = iio_read_channel_raw(channel, &val);
@ -155,10 +155,10 @@ static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata)
}
/* unit: mV */
result = pdata->pullup_uv * val;
result = pdata->pullup_uv * (s64) val;
result >>= 12;
return result;
return (int)result;
}
static const struct of_device_id ntc_match[] = {