diff mbox series

[v9,08/14] iio: afe: rescale: reduce risk of integer overflow

Message ID 20211115034334.1713050-9-liambeguin@gmail.com (mailing list archive)
State Changes Requested
Headers show
Series iio: afe: add temperature rescaling support | expand

Commit Message

Liam Beguin Nov. 15, 2021, 3:43 a.m. UTC 
From: Liam Beguin <lvb@xiphos.com>

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 <lvb@xiphos.com>
---
 drivers/iio/afe/iio-rescale.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/iio/afe/iio-rescale.c b/drivers/iio/afe/iio-rescale.c
index 394f8b16b29c..17036130d364 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);