Re: [PATCH v13 02/12] iio: kstrtox: add local _parse_integer_limit_init() helper

[Jonathan Cameron <jic23@kernel.org>]

On Sun, 17 May 2026 10:13:57 +0100
Rodrigo Alencar via B4 Relay <devnull+rodrigo.alencar.analog.com@kernel.org> wrote:

> From: Rodrigo Alencar <rodrigo.alencar@analog.com>
> 
> Add parsing helper that accepts an initial value for the accumulated
> result when parsing an 64-bit integer. It reuses current implementation
> for _parse_integer_limit(), which now consumes the new function with
> init = 0. The diff algorithm would have the documentation header and
> prototype of _parse_integer_limit() moved around so it is adjusted
> according to guidelines.
> 
> Signed-off-by: Rodrigo Alencar <rodrigo.alencar@analog.com>
Sashiko makes a good point on this. It is not currently IIO specific
so the patch title should make that clear.

kstrox: add local_parse_integer_limit_init() helper.

> ---
>  lib/kstrtox.c | 39 ++++++++++++++++++++++++++-------------
>  1 file changed, 26 insertions(+), 13 deletions(-)
> 
> diff --git a/lib/kstrtox.c b/lib/kstrtox.c
> index 97be2a39f537..0705461f51c0 100644
> --- a/lib/kstrtox.c
> +++ b/lib/kstrtox.c
> @@ -39,23 +39,15 @@ const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
>  	return s;
>  }
>  
> -/*
> - * Convert non-negative integer string representation in explicitly given radix
> - * to an integer. A maximum of max_chars characters will be converted.
> - *
> - * Return number of characters consumed maybe or-ed with overflow bit.
> - * If overflow occurs, result integer (incorrect) is still returned.
> - *
> - * Don't you dare use this function.
> - */
> -noinline
> -unsigned int _parse_integer_limit(const char *s, unsigned int base, unsigned long long *p,
> -				  size_t max_chars)
> +static unsigned int _parse_integer_limit_init(const char *s, unsigned int base,
> +					      unsigned long long init,
> +					      unsigned long long *p,
> +					      size_t max_chars)
>  {
>  	unsigned long long res;
>  	unsigned int rv;
>  
> -	res = 0;
> +	res = init;
>  	rv = 0;
>  	while (max_chars--) {
>  		unsigned int c = *s;
> @@ -87,6 +79,27 @@ unsigned int _parse_integer_limit(const char *s, unsigned int base, unsigned lon
>  	return rv;
>  }
>  
> +/**
> + * _parse_integer_limit() - Convert integer string representation to an integer
> + *			    limiting the number of characters parsed.
> + * @s: The start of the string.
> + * @base: The number base to use.
> + * @p: Where to write the result of the conversion.
> + * @max_chars: Maximum amount of characters to consume.
> + *
> + * Convert non-negative integer string representation in explicitly given radix
> + * to an integer. A maximum of max_chars characters will be converted.
> + *
> + * Return: Number of characters consumed maybe or-ed with overflow bit.
> + *	   If overflow occurs, result integer (incorrect) is still returned.
> + */
> +noinline
> +unsigned int _parse_integer_limit(const char *s, unsigned int base,
> +				  unsigned long long *p, size_t max_chars)
> +{
> +	return _parse_integer_limit_init(s, base, 0, p, max_chars);
> +}
> +
>  noinline
>  unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
>  {
>