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

From: Anshul Garg
Date: Thu Jan 22 2015 - 08:39:01 EST


Dear Mr. Levente ,


Thanks for the reply.

I will segregate this patch in two different patches.

I will send these patches again.


Thanks
Anshul Garg



On Thu, Jan 22, 2015 at 1:09 AM, Levente Kurusa <levex@xxxxxxxxx> wrote:
> 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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