Re: [PATCH 2/5] lib: rework bitmap_parselist

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Yury Norov <yury.norov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
	Matthew Wilcox <willy@infradead.org>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Mike Travis <travis@sgi.com>, Yury Norov <ynorov@marvell.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] lib: rework bitmap_parselist
Date: Mon, 8 Apr 2019 12:55:40 +0300	[thread overview]
Message-ID: <20190408095540.GG9224@smile.fi.intel.com> (raw)
In-Reply-To: <20190405173211.11373-3-ynorov@marvell.com>

On Fri, Apr 05, 2019 at 08:32:08PM +0300, Yury Norov wrote:
> Remove __bitmap_parselist helper and split the function to logical
> parts.

> +static const char *bitmap_getnum(const char *str, unsigned int *num)
> +{
> +	unsigned int n = 0, _num = 0;
> +
> +	if (!isdigit(*str))
> +		return ERR_PTR(-EINVAL);
> +
> +	for (; isdigit(*str); str++) {
> +		_num = _num * 10 + (*str - '0');
> +		if (_num < n)
> +			return ERR_PTR(-EOVERFLOW);
> +
> +		n = _num;
> +	}
> +
> +	*num = _num;
> +
> +	return str;
> +}

This looks like (semi) open coded simple_strtoull()

unsigned long long _num;
char *endp;

_num = simple_strtoull(str, &endp, 10);
if (endp == str)
	return ERR_PTR(-EINVAL);
if (_num > UINT_MAX || (endp - str) > 10)
	return ERR_PTR(-EOVERFLOW);
*num = _num;
return endp;

> +static inline bool end_of_str(char c)
> +{
> +	return c == '\0' || c == '\n';
> +}

This reminds me a check at the end of _kstrtoull(). Can we use same approach in
both cases?

-- 
With Best Regards,
Andy Shevchenko