Re: Build error kernel/cgroup/rstat.c on v6.7-1959-gaffc5af36bbb

[Arnd Bergmann]

On Wed, Jan 10, 2024, at 20:50, Thomas Voegtle wrote:
> Hello,
>
> building v6.7-1959-gaffc5af36bbb I get this:
>
> ...
>    CALL    scripts/checksyscalls.sh
>    DESCEND objtool
>    INSTALL libsubcmd_headers
>    CC      kernel/cgroup/rstat.o
> kernel/cgroup/rstat.c:218:22: error: no previous prototype for
> ‘bpf_rstat_flush’ [-Werror=missing-prototypes]
>   __weak noinline void bpf_rstat_flush(struct cgroup *cgrp,
>                        ^~~~~~~~~~~~~~~
>
>
> git bisects points to:
>
> commit 0fcb70851fbfea1776ae62f67c503fef8f0292b9 (refs/bisect/bad)
> Author: Arnd Bergmann <arnd@xxxxxxxx>
> Date:   Thu Nov 23 12:05:06 2023 +0100
>
>      Makefile.extrawarn: turn on missing-prototypes globally
>
>
> My config is attached.
> openSUSE Leap 15.5 x86_64 with gcc 7.5.0
>
>
> Is this already known?

There is a workaround in linux-next, see commit
15fb6f2b6c4c ("bpf: Add __bpf_hook_{start,end} macros")

I assume this will be merged soon.

     Arnd