@@ -342,10 +342,10 @@ static s16 bme680_compensate_temp(struct bme680_data *data,
if (!calib->par_t2)
bme680_read_calib(data, calib);
- var1 = (adc_temp >> 3) - (calib->par_t1 << 1);
+ var1 = (adc_temp >> 3) - ((s32)calib->par_t1 << 1);
var2 = (var1 * calib->par_t2) >> 11;
var3 = ((var1 >> 1) * (var1 >> 1)) >> 12;
- var3 = (var3 * (calib->par_t3 << 4)) >> 14;
+ var3 = (var3 * ((s32)calib->par_t3 << 4)) >> 14;
data->t_fine = var2 + var3;
calc_temp = (data->t_fine * 5 + 128) >> 8;
@@ -368,9 +368,9 @@ static u32 bme680_compensate_press(struct bme680_data *data,
var1 = (data->t_fine >> 1) - 64000;
var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2;
var2 = var2 + (var1 * calib->par_p5 << 1);
- var2 = (var2 >> 2) + (calib->par_p4 << 16);
+ var2 = (var2 >> 2) + ((s32)calib->par_p4 << 16);
var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) *
- (calib->par_p3 << 5)) >> 3) +
+ ((s32)calib->par_p3 << 5)) >> 3) +
((calib->par_p2 * var1) >> 1);
var1 = var1 >> 18;
var1 = ((32768 + var1) * calib->par_p1) >> 15;
@@ -388,7 +388,7 @@ static u32 bme680_compensate_press(struct bme680_data *data,
var3 = ((press_comp >> 8) * (press_comp >> 8) *
(press_comp >> 8) * calib->par_p10) >> 17;
- press_comp += (var1 + var2 + var3 + (calib->par_p7 << 7)) >> 4;
+ press_comp += (var1 + var2 + var3 + ((s32)calib->par_p7 << 7)) >> 4;
return press_comp;
}
@@ -414,7 +414,7 @@ static u32 bme680_compensate_humid(struct bme680_data *data,
(((temp_scaled * ((temp_scaled * calib->par_h5) / 100))
>> 6) / 100) + (1 << 14))) >> 10;
var3 = var1 * var2;
- var4 = calib->par_h6 << 7;
+ var4 = (s32)calib->par_h6 << 7;
var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4;
var5 = ((var3 >> 14) * (var3 >> 14)) >> 10;
var6 = (var4 * var5) >> 1;
There are cases in the compensate functions of the driver that there could be overflows of variables due to bit shifting ops. These implications were initially discussed here [1] and they were mentioned in log message of Commit 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor"). [1]: https://lore.kernel.org/linux-iio/20180728114028.3c1bbe81@archlinux/ Fixes: 1b3bd8592780 ("iio: chemical: Add support for Bosch BME680 sensor") Signed-off-by: Vasileios Amoiridis <vassilisamir@gmail.com> --- drivers/iio/chemical/bme680_core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)