Re: [PATCH 5.15 0/5] Support static calls with LLVM-built kernels

Sasha Levin
2024-03-16T11:01:48Z

On Sat, Mar 16, 2024 at 07:02:19AM -0300, Thadeu Lima de Souza Cascardo wrote:
>On Sat, Mar 16, 2024 at 05:41:16AM -0400, Sasha Levin wrote:
>> On Wed, Mar 13, 2024 at 07:42:50AM -0300, Thadeu Lima de Souza Cascardo wrote:
>> > Peter Zijlstra (4):
>> > arch: Introduce CONFIG_FUNCTION_ALIGNMENT
>> > x86/alternatives: Introduce int3_emulate_jcc()
>> > x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions
>> > x86/static_call: Add support for Jcc tail-calls
>> >
>> > Thomas Gleixner (1):
>> > x86/asm: Differentiate between code and function alignment
>>
>> Is this not an issue on 6.1? I don't see d49a0626216b ("arch: Introduce
>> CONFIG_FUNCTION_ALIGNMENT") in that tree.
>>
>> --
>> Thanks,
>> Sasha
>
>The fix is really the last patch, 923510c88d2b ("x86/static_call: Add support
>for Jcc tail-calls"). I see that 6.1 got 3,4,5:
>
>9d80f3e60043 x86/static_call: Add support for Jcc tail-calls
>c51a456b4179 x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions
>75c066485bcb x86/alternatives: Introduce int3_emulate_jcc()
>
>I can resubmit the series without the first two patches if that is preferred.

I'm just curious why we needed the first two patches on 5.15 but not on 6.1.

--
Thanks,
Sasha