Re: [PATCH v11 09/15] iio: afe: rescale: reduce risk of integer overflow

[Andy Shevchenko]

On Wed, Dec 22, 2021 at 5:47 AM Liam Beguin <liambeguin@xxxxxxxxx> wrote:
>
> From: Liam Beguin <lvb@xxxxxxxxxx>
>
> 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.

...

> -               tmp = 1 << *val2;

At some point this should be BIT()
Rule of thumb (in accordance with C standard), always use unsigned
value as left operand of the _left_ shift.

> +               if (scale_type == IIO_VAL_FRACTIONAL)
> +                       tmp = *val2;
> +               else
> +                       tmp = 1 << *val2;


-- 
With Best Regards,
Andy Shevchenko