Re: [PATCH v2 bpf-next 1/2] bpf: Add __bpf_kfunc_{start,end}_defs macros

[David Vernet <void@manifault.com>]

On Tue, Oct 31, 2023 at 02:56:24PM -0700, Dave Marchevsky wrote:
> BPF kfuncs are meant to be called from BPF programs. Accordingly, most
> kfuncs are not called from anywhere in the kernel, which the
> -Wmissing-prototypes warning is unhappy about. We've peppered
> __diag_ignore_all("-Wmissing-prototypes", ... everywhere kfuncs are
> defined in the codebase to suppress this warning.
> 
> This patch adds two macros meant to bound one or many kfunc definitions.
> All existing kfunc definitions which use these __diag calls to suppress
> -Wmissing-prototypes are migrated to use the newly-introduced macros.
> A new __diag_ignore_all - for "-Wmissing-declarations" - is added to the
> __bpf_kfunc_start_defs macro based on feedback from Andrii on an earlier
> version of this patch [0] and another recent mailing list thread [1].
> 
> In the future we might need to ignore different warnings or do other
> kfunc-specific things. This change will make it easier to make such
> modifications for all kfunc defs.
> 
>   [0]: https://lore.kernel.org/bpf/CAEf4BzaE5dRWtK6RPLnjTW-MW9sx9K3Fn6uwqCTChK2Dcb1Xig@mail.gmail.com/
>   [1]: https://lore.kernel.org/bpf/ZT+2qCc%2FaXep0%2FLf@krava/
> 
> Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
> Suggested-by: Andrii Nakryiko <andrii@kernel.org>
> Acked-by: Andrii Nakryiko <andrii@kernel.org>
> Cc: Jiri Olsa <olsajiri@gmail.com>

Acked-by: David Vernet <void@manifault.com>

Thanks for taking care of this!