Re: [PATCH] lib/kstrtox.c break if overflow is detected

From: Levente Kurusa
Date: Wed Jan 21 2015 - 14:39:23 EST


Hi,

On Wed, Jan 21, 2015 at 11:26:26AM -0800, Anshul Garg wrote:
> From: Anshul Garg <aksgarg1989@xxxxxxxxx>
>
> 1. While converting string representation to integer
> break the loop if overflow is detected.
> 2. Clean kstrtoll function
>
> Signed-off-by: Anshul Garg <aksgarg1989@xxxxxxxxx>
> ---
> lib/kstrtox.c | 28 +++++++++++++---------------
> 1 file changed, 13 insertions(+), 15 deletions(-)
>
> diff --git a/lib/kstrtox.c b/lib/kstrtox.c
> index ec8da78..8cbe5ca 100644
> --- a/lib/kstrtox.c
> +++ b/lib/kstrtox.c
> @@ -70,8 +70,10 @@ unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long
> * it in the max base we support (16)
> */
> if (unlikely(res & (~0ull << 60))) {
> - if (res > div_u64(ULLONG_MAX - val, base))
> + if (res > div_u64(ULLONG_MAX - val, base)) {
> overflow = 1;
> + break;
> + }
> }
> res = res * base + val;
> rv++;
> @@ -146,23 +148,19 @@ EXPORT_SYMBOL(kstrtoull);
> int kstrtoll(const char *s, unsigned int base, long long *res)
> {
> unsigned long long tmp;
> - int rv;
> + int rv, sign = 1;
>
> if (s[0] == '-') {
> - rv = _kstrtoull(s + 1, base, &tmp);
> - if (rv < 0)
> - return rv;
> - if ((long long)(-tmp) >= 0)
> - return -ERANGE;
> - *res = -tmp;
> - } else {
> - rv = kstrtoull(s, base, &tmp);
> - if (rv < 0)
> - return rv;
> - if ((long long)tmp < 0)
> - return -ERANGE;
> - *res = tmp;
> + sign = -1;
> + s++;
> }
> +
> + rv = kstrtoull(s, base, &tmp);
> + if (rv < 0)
> + return rv;
> + if ((long long)tmp < 0)
> + return -ERANGE;
> + *res = sign * tmp;
> return 0;
> }
> EXPORT_SYMBOL(kstrtoll);

Looks correct to me, so:

Reviewed-by: Levente Kurusa <levex@xxxxxxxxx>

But I believe the two hunks are completely unrelated to
eachother and hence should split into a patch series.

Could you please do that and resend? Or if Andrew is OK
with picking it up as is, then it's fine.

Thanks,
Levente.

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