Re: [PATCH] x86: Start removing X86_X32_ABI

[Thomas Gleixner]

On Sat, May 23 2026 at 14:43, H. Peter Anvin wrote:
> On May 23, 2026 2:37:34 AM PDT, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:
>>-
>> config COMPAT_32
>> 	def_bool y
>> 	depends on IA32_EMULATION || X86_32
>
> So I'm not opposed to sunsetting x32; it happened too late to actually
> be able to become useful (sorry, Knuth.)

I doubt it was ever useful, but that's a different debate to be had.

> However, we can not recycle the syscall numbers. The x32 flag in the
> syscall number was advisory originally; it was introduced late in the
> game to work around a design bug in the input subsystem (*).

Correct. That's unfortunate and basically forces us to skip the
arbitrary x32 range for all architectures if we want to keep the syscall
numbers in sync.

But aside of that x32 is just another maintenance burden for no value.

Please let us get rid of it and document that the syscall number space
is poisened forever.

Thanks,

        tglx