Re: [PATCH RFC v2 0/2] arm64: vdso: Implement __vdso_futex_robust_try_unlock()
From: André Almeida
Date: Fri May 22 2026 - 18:12:09 EST
Hi Sebastian,
Em 28/04/2026 08:00, Sebastian Andrzej Siewior escreveu:
On 2026-04-24 15:55:59 [-0300], André Almeida wrote:Sorry for my delay. Yes, I had to do some modifications for the test (will reply to your patch) and spot one error in my patch, and now the test passes, thanks! Will send a v3 for this soon.
Hi folks,Hi,
This is my take on implementing the new vDSO for unlocking a robust futex in
arm64. If you don't know what's that, Thomas wrote a good summary,
including the motivation for this work and the x86 implementation:
https://lore.kernel.org/lkml/878qb89g7b.ffs@tglx/
There are some loose ends in my patchset so I'm sending as a RFC to ask
some questions:
- If the process is interrupted between the labels, we need to check the
conditional flags and clear the op_pending address from the register. Using
objdump I see that op_pending addr is being stored at x2, but I suspect that
this isn't stable, so I need to figure out how to make sure that the address
will always be stored in the same register.
- So far I have implemented only the LL/SC version to make review easier, but I
can do the LSE version as well.
I am a bit behind here. In the meantime, were you able to check it with
https://lore.kernel.org/all/20260404093939.7XgeW_54@xxxxxxxxxxxxx/
?