Re: [PATCH] futex: remove unused empty compat_exit_robust_list()

From: Thomas Gleixner
Date: Fri Nov 13 2020 - 19:15:57 EST


Lukas,

On Fri, Nov 13 2020 at 18:20, Lukas Bulwahn wrote:
> Commit ba31c1a48538 ("futex: Move futex exit handling into futex code")
> introduced compat_exit_robust_list() with a full-fledged implementation for
> CONFIG_COMPAT, and an empty-body function for !CONFIG_COMPAT.
> However, compat_exit_robust_list() is only used in futex_mm_release() under
> ifdef CONFIG_COMPAT.
>
> Hence for !CONFIG_COMPAT, make CC=clang W=1 warns:
>
> kernel/futex.c:314:20:
> warning: unused function 'compat_exit_robust_list' [-Wunused-function]
>
> There is no need to declare the unused empty function for !CONFIG_COMPAT.
> Simply, remove it to address the -Wunused-function warning.

While I agree with the removal, I disagree with the reasoning.

The real argument is that the stub function is useless. Addressing the
warning is a side effect of the removal, nothing else.

Thanks,

tglx