[PATCH v8 08/14] iio: afe: rescale: reduce risk of integer overflow
From: Liam Beguin <hidden>
Date: 2021-08-20 19:18:20
Also in:
linux-devicetree, lkml
Subsystem:
iio subsystem and drivers, iio unit converter, the rest · Maintainers:
Jonathan Cameron, Peter Rosin, Linus Torvalds
From: Liam Beguin <redacted> Reduce the risk of integer overflow by doing the scale calculation on a 64-bit integer. Since the rescaling is only performed on *val, reuse the IIO_VAL_FRACTIONAL_LOG2 case. Signed-off-by: Liam Beguin <redacted> --- drivers/iio/afe/iio-rescale.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c
index 809e966f7058..c408c4057c08 100644
--- a/drivers/iio/afe/iio-rescale.c
+++ b/drivers/iio/afe/iio-rescale.c@@ -27,16 +27,13 @@ int rescale_process_scale(struct rescale *rescale, int scale_type, u32 neg; switch (scale_type) { - case IIO_VAL_FRACTIONAL: - *val *= rescale->numerator; - *val2 *= rescale->denominator; - return scale_type; case IIO_VAL_INT: *val *= rescale->numerator; if (rescale->denominator == 1) return scale_type; *val2 = rescale->denominator; return IIO_VAL_FRACTIONAL; + case IIO_VAL_FRACTIONAL: case IIO_VAL_FRACTIONAL_LOG2: tmp = (s64)*val * 1000000000LL; tmp = div_s64(tmp, rescale->denominator);
--
2.32.0.452.g940fe202adcb