Re: [RFC PATCH] futex: Introduce __vdso_robust_futex_unlock

[Mathieu Desnoyers]

On 2026-03-12 10:04, Mathieu Desnoyers wrote:
> On 2026-03-12 09:46, André Almeida wrote:
[...]
> > First because we have FUTEX2_SIZE's, so uaddr could have different 
> > size here.

The robust futex ABI defines:

#define FUTEX_OWNER_DIED        0x40000000
#define FUTEX_WAITERS           0x80000000

So how can a robust futex use a uaddr smaller than 32-bit ?

And if the uaddr is 64-bit, I would expect those two values
to be bits 63 and 62 (indexed from 0), but this contradicts
the defines.

What am I missing ?

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com