Re: [patch V4 12/14] x86/vdso: Implement __vdso_futex_robust_try_unlock()

[Thomas Gleixner]

On Wed, Apr 29 2026 at 10:44, Thomas Weißschuh wrote:
> On 2026-04-02 17:22:00+0200, Thomas Gleixner wrote:
> (...)
>
>> + * When CONFIG_COMPAT is enabled then the 64-bit VDSO provides two functions.
>> + * One for the regular 64-bit sized pending operation pointer and one for a
>> + * 32-bit sized pointer to support gaming emulators.
>
> These gaming emulators can emulate 32-bit code on 64-bit kernels even
> without CONFIG_COMPAT. At least this is how I understand Wine WoW64 and
> FEX-Emu. And in that case the 32-bit sized pointer function should be
> available unconditionally, without the dependency on CONFIG_COMPAT.

That might well be, but that requires also the ability to register a
32-bit robust list for a 64-bit process, which is not supported right
now.

So no, we are not exposing something half functional just because. That
needs to be mopped up once we add the multi-robust list stuff.

Thanks,

        tglx