Re: [PATCH v1 1/1] math.h: Amend kernel-doc and add a note about signed type limits
From: Kuan-Wei Chiu
Date: Mon Nov 10 2025 - 10:34:43 EST
On Thu, Nov 06, 2025 at 04:20:51PM +0100, Andy Shevchenko wrote:
> First of all, amend the existing kernel-doc so the description
> of the function is decoupled with the parameter descriptions.
> Second, add a note to explain behaviour for the signed types when
> supplied value is the minimum (e.g., INT_MIN for int type).
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> include/linux/math.h | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/math.h b/include/linux/math.h
> index 7fcb980677a0..c02cc5b9e6ae 100644
> --- a/include/linux/math.h
> +++ b/include/linux/math.h
> @@ -180,11 +180,16 @@ __STRUCT_FRACT(u32)
>
> /**
> * abs - return absolute value of an argument
> - * @x: the value. If it is unsigned type, it is converted to signed type first.
> - * char is treated as if it was signed (regardless of whether it really is)
> - * but the macro's return type is preserved as char.
> + * @x: the value.
> *
> - * Return: an absolute value of x.
> + * If it is unsigned type, @x is converted to signed type first.
> + * char is treated as if it was signed (regardless of whether it really is)
> + * but the macro's return type is preserved as char.
> + *
> + * NOTE, for signed type if @x is the minimum, the returned result is undefined
> + * as there is not enough bits to represent it as a positive number.
Nit: s/is/are
Otherwise, the patch is:
Reviewed-by: Kuan-Wei Chiu <visitorckw@xxxxxxxxx>
Regards,
Kuan-Wei
> + *
> + * Return: an absolute value of @x.
> */
> #define abs(x) __abs_choose_expr(x, long long, \
> __abs_choose_expr(x, long, \
> --
> 2.50.1
>
>