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drivers/adxl372: Fix computation of sensor value

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Sensor value computation was creating a 64-bit integer value, passing
that to 'abs' and assigning that to an int32_t result and then sanity
checking the result. If the computation goes badly wrong, then the range
reduction of 64-bit to 32-bit values could generate a falsely in-range
value.

Instead, perform the computation in 64-bits, range check that value and
then assign to a 32-bit variable.

Signed-off-by: Keith Packard <keithp@keithp.com>
This commit is contained in:
Keith Packard 2022-04-27 18:23:01 -07:00 • committed by Stephanos Ioannidis
commit 7c6fe0735d
1 changed files with 5 additions and 2 deletions
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7
drivers/sensor/adxl372/adxl372.c
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@ -643,16 +643,19 @@ static int adxl372_attr_set_thresh(const struct device *dev,
{
const struct adxl372_dev_config *cfg = dev->config;
struct adxl372_activity_threshold threshold;
int64_t llvalue;
int32_t value;
int64_t micro_ms2 = val->val1 * 1000000LL + val->val2;
uint8_t reg;
value = abs((micro_ms2 * 10) / SENSOR_G);
llvalue = llabs((micro_ms2 * 10) / SENSOR_G);
if (value > 2047) {
if (llvalue > 2047) {
return -EINVAL;
}
value = (int32_t) llvalue;
threshold.thresh = value;
threshold.enable = cfg->activity_th.enable;
threshold.referenced = cfg->activity_th.referenced;