Re: [PATCH v4 1/5] arm64/entry: Unify user mode handling

[André Almeida]

Em 05/07/2026 14:56, André Almeida escreveu:
> Currently, arm64 has two functions to prepare and handle context switches
> from userspace: arm64_syscall_enter_from_user_mode() and
> arm64_enter_from_user_mode(). The only difference is that the later calls
> rseq_note_user_irq_entry() that sets rseq.event.user_irq as true.
>
> To ensure that futex_fixup_robust_unlock() works correctly, unify the
> handling from user mode functions into one that always calls
> rseq_note_user_irq_entry().
>
> Other architectures calls irqentry_enter_from_user_mode() for syscalls
> and interruptions, that sets rseq.event.user_irq as well.
>
> Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>

It turns out that this patch is not needed at all and 
futex_fixup_robust_unlock() is already working correctly for arm64. The 
user thread can't call a syscall in the middle of the vdso function.