Re: [PATCH 2/2] lib: call native hex_to_bin() inside _kstrtoull()

From: Alexey Dobriyan
Date: Mon Jul 18 2011 - 06:31:23 EST


On Mon, Jul 18, 2011 at 11:23 AM, Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> --- a/lib/kstrtox.c
> +++ b/lib/kstrtox.c
> @@ -39,25 +39,18 @@ static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
>        acc = 0;
>        ok = 0;
>        while (*s) {
> -               unsigned int val;
> +               int val;
>
> -               if ('0' <= *s && *s <= '9')
> -                       val = *s - '0';
> -               else if ('a' <= TOLOWER(*s) && TOLOWER(*s) <= 'f')
> -                       val = TOLOWER(*s) - 'a' + 10;
> -               else if (*s == '\n' && *(s + 1) == '\0')
> +               if (unlikely(*s == '\n' && *(s + 1) == '\0'))
>                        break;
> -               else
> -                       return -EINVAL;
>
> -               if (val >= base)
> +               val = hex_to_bin(*s++);
> +               if (val >= base || val < 0)
>                        return -EINVAL;
>                if (acc > div_u64(ULLONG_MAX - val, base))
>                        return -ERANGE;
>                acc = acc * base + val;
>                ok = 1;
> -
> -               s++;
>        }
>        if (!ok)
>                return -EINVAL;

1. unlikely() and s++ move don't have anything to do with changes
2. I don't understand desire to use some half-thought out API,
in fact, restricting to radix 16 is arbitrary.
Without such restriction hex_to_bin doesn't make sense.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/