[PATCH] powerpc: build-time fixup alternate feature relative addresses

[Christophe Leroy]

Le 29/01/2024 à 07:25, Sathvika Vasireddy a écrit :
> Hi Christophe, Nick
> 
> On 1/26/24 12:32 AM, Christophe Leroy wrote:
>> Hi Nic,
>>
>> Le 21/05/2017 à 03:01, Nicholas Piggin a écrit :
>>> Implement build-time fixup of alternate feature relative addresses for
>>> the out-of-line ("else") patch code. This is done post-link with a new
>>> powerpc build tool that parses relocations and fixup structures, and
>>> adjusts branch instructions.
>>>
>>> This gives us the ability to link patch code anywhere in the kernel,
>>> without branches to targets outside the patch code having to be
>>> reached directly (without a linker stub). This allows patch code to be
>>> moved out from the head section, and avoids build failures with
>>> unresolvable branche.
>>
>> Is it worth keeping this hanging in patchwork ? It seems outdated and 
>> doesn't apply. Could this me done with objtool instead ?
>>
>> Christophe
> 
> Yes, this can be done with objtool. I am working on this and will post 
> an RFC this week.
> 

Nice.

I've open an issue to track his at 
https://github.com/linuxppc/issues/issues/479 and have retired Nic's 
patch in patchwork.

Christophe