Re: [patch v2 04/11] uaccess: Provide unsafe_atomic_store_release_user()

[André Almeida]

Em 19/03/2026 20:24, Thomas Gleixner escreveu:
> The upcoming support for unlocking robust futexes in the kernel requires
> store release semantics. Syscalls do not imply memory ordering on all
> architectures so the unlock operation requires a barrier.
>
> This barrier can be avoided when stores imply release like on x86.
>
> Provide a generic version with a smp_mb() before the unsafe_put_user(),
> which can be overridden by architectures.
>
> Provide also a ARCH_STORE_IMPLIES_RELEASE Kconfig option, which can be
> selected by architectures where store implies release, so that the smp_mb()
> in the generic implementation can be avoided.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>

Reviewed-by: André Almeida <andrealmeid@xxxxxxxxxx>