Re: [RFC v2 PATCH 7/7] x86/entry: use int for syscall number; handle all invalid syscall nrs

From: Thomas Gleixner
Date: Wed May 12 2021 - 18:36:27 EST


On Wed, May 12 2021 at 15:09, H. Peter Anvin wrote:
> On 5/12/21 11:34 AM, Thomas Gleixner wrote:
>>>
>>> That is intentional, as (again) system calls are int.
>>
>> They are 'int' kernel internally, but _NOT_ at the user space visible
>> side. Again: man syscall
>>
>> syscall(long number,...);
>>
>> So that results in a user ABI change.
>>
>>> As stated in my reply to Ingo, I'll clean the various descriptions and
>>> try to capture the discussion better.
>>
>> If we agree to go there then this wants to be a seperate commit which
>> does nothing else than changing this behaviour.
>>
>
> Good idea.
>
> As far as this being a user ABI change, this is actually a revert to the
> original x86-64 ABI; see my message to Ingo.

I'm not against that change, but it has to be well justified and the
reasoning wants to be in the changelog. You know the drill :)

Thanks,

tglx