[PATCH v2] net/tap: resolve stringop-overflow with gcc 12 on ppc64le

[Ferruh Yigit]

On 6/7/2023 7:47 PM, Ferruh Yigit wrote:
> On 5/16/2023 10:55 AM, Ferruh Yigit wrote:
>> On 5/16/2023 2:28 AM, Stephen Hemminger wrote:
>>> On Tue, 16 May 2023 00:35:56 +0100
>>> Ferruh Yigit <ferruh.yigit at amd.com> wrote:
>>>
>>>> Yes only some scripts and possible applications that hotplug tap
>>>> interface with hardcoded parameters may impacted, don't know how big is
>>>> this amount but this ends up breaking something that was working before
>>>> upgrading DPDK for them.
>>>>
>>>> And I believe the motivation is weak to break the behavior.
>>>>
>>>> Won't it be better to update 'rte_ether_unformat_addr()' to accept more
>>>> flexible syntax, and use it? Is there any disadvantage of this approach?
>>>
>>> It is already more flexible than the standard ether_aton().
>>
>> I mean to accept single chars, as 'tap' currently does, like "a:a:a:a:a:a".
>>
>> Agree that impact of tap change is small, but if we can eliminate it
>> completely without any side affect, why not?
>>
>>
>> As accepting single char will be expanding 'rte_ether_unformat_addr()'
>> capability, it will be backward compatible, am I missing anything?
>>
> 
> Hi David,
> 
> If API update is not planned, what do you think to just solve the build
> error without changing functionality with a change something like below:
> 
> ```
>  -       (strlen(mac_byte) == strspn(mac_byte,
>  -                       ETH_TAP_CMP_MAC_FMT))) {
>  +       (strlen(mac_byte) == strspn(mac_byte, ETH_TAP_CMP_MAC_FMT)) &&
>  +                       index < RTE_ETHER_ADDR_LEN) {
> 
> ```

Hi David,

If you can confirm above fixes the issue, I can send a patch for it.