From: Liam Beguin liambeguin@gmail.com
commit 51593106b608ae4247cc8da928813347da16d025 upstream.
All four scaling coefficients can take signed values. Make tmp a signed 64-bit integer and switch to div_s64() to preserve signs during 64-bit divisions.
Fixes: 8b74816b5a9a ("iio: afe: rescale: new driver") Signed-off-by: Liam Beguin liambeguin@gmail.com Reviewed-by: Peter Rosin peda@axentia.se Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Link: https://lore.kernel.org/r/20220108205319.2046348-5-liambeguin@gmail.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/afe/iio-rescale.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/iio/afe/iio-rescale.c +++ b/drivers/iio/afe/iio-rescale.c @@ -39,7 +39,7 @@ static int rescale_read_raw(struct iio_d int *val, int *val2, long mask) { struct rescale *rescale = iio_priv(indio_dev); - unsigned long long tmp; + s64 tmp; int ret;
switch (mask) { @@ -77,10 +77,10 @@ static int rescale_read_raw(struct iio_d *val2 = rescale->denominator; return IIO_VAL_FRACTIONAL; case IIO_VAL_FRACTIONAL_LOG2: - tmp = *val * 1000000000LL; - do_div(tmp, rescale->denominator); + tmp = (s64)*val * 1000000000LL; + tmp = div_s64(tmp, rescale->denominator); tmp *= rescale->numerator; - do_div(tmp, 1000000000LL); + tmp = div_s64(tmp, 1000000000LL); *val = tmp; return ret; default: