Re: [PATCH RFC 1/4] syscalls: Create unified partial table for all archs

[H. Peter Anvin]

On July 24, 2026 1:25:05 PM PDT, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>On Fri, Jul 24, 2026, at 22:18, André Almeida wrote:
>> Em 24/07/2026 17:09, Arnd Bergmann escreveu:
>>> On Fri, Jul 24, 2026, at 22:00, André Almeida wrote:
>>> It should really be anything starting at 403, not just 442 and higher.
>>> 
>>> There are some trivial differences that have crept in over time,
>>> but we should be able to work around those.
>>> 
>>
>> The thing that prevent me starting before 442 was how to deal with 
>> compat. If I add to the table
>>
>> 441	common	epoll_pwait2		sys_epoll_pwait2		compat_sys_epoll_pwait2
>>
>> It will wrongly add
>>
>> __SYSCALL_WITH_COMPAT(441, sys_epoll_pwait2, compat_sys_epoll_pwait2)
>>
>> to arch/x86/include/generated/asm/syscalls_64.h.
>>
>> Maybe I could add a --ignore-compat to scripts/syscalltbl.sh, and add 
>> this flag for 64 builds. What do you think?
>
>IIRC, we can just use compat_sys_epoll_pwait2 for both i386
>and x32, because compat_sigset_t is compatible with sigset_t --
>they are only really different on big-endian targets, which
>count the bits in a u64 different from two u32.
>
>This problem also goes away once x32 is gone.
>
>      Arnd
>

No reason to introduce another entry point if there's no difference. 

x86, after all, is littleendian and alignment-tolerant.