Re: [PATCH RFC] wifi: ath12k: workaround fortify warnings in ath12k_wow_convert_8023_to_80211()

Kalle Valo
2024-07-31T16:14:09Z

Kalle Valo <kvalo@kernel.org> writes:

> "Arnd Bergmann" <arnd@arndb.de> writes:
>
>> On Mon, Jul 8, 2024, at 21:31, Kees Cook wrote:
>>> On Mon, Jul 08, 2024 at 06:51:52PM +0300, Kalle Valo wrote:
>>>
>>> I suspect this won't be the only place in the kernel where -Wrestrict
>>> will give weird results with GCC 11, and there are still plenty of folks
>>> using GCC 11. I think the best option would probably be to version-check
>>> GCC to gate the addition of -Wrestrict.
>>>
>>> Arnd, what do you think? This looks like a more extreme version of
>>> commit f9fc1ec28bae ("crypto: drivers - avoid memcpy size warning")
>>
>> The f9fc1ec28bae patch was the other way around, it showed up
>> in new compilers but not old ones. I don't think I've seen
>> more gcc-11 -Wrestrict warnings during testing, but I'm currently
>> not set up to do a thorough search. If it's the only one, then
>> Kalle's suggested workaround is probably best, but if there
>> are additional warnings on gcc-11, making the warning depend
>> newer compilers is also fine.
>
> Honestly I was hoping that we could disable the warning for GCC 11 :)
>
> I feel bad making the code worse due to a compiler problem. For example,
> Intel's zero day bot doesn't seem to use GCC 11 that much anymore, so it
> might surprise more people than just us ath12k folks. (The bot said
> everything was fine but Johannes saw the warning when the code was
> pulled to wireless-next.)
>
>> I just don't want to give up the warning for new compilers altogether.
>
> Me neither. I'm just hoping that we could disable it for GCC 11. But of
> course if you think it's better to add the workaround to ath12k, I can
> submit a proper (non-RFC) patch to do that.

For the archives: Paolo found a nicer way which is now commited:

https://git.kernel.org/linus/b49991d83bba

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