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

[Thomas Voegtle]

On Thu, 11 Jan 2024, Arnd Bergmann wrote:

> On Wed, Jan 10, 2024, at 22:18, Thomas Voegtle wrote:
> > On Wed, 10 Jan 2024, Arnd Bergmann wrote:
> >
> > > 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.
> >
> > That commit is already merged?
>
> It's probably missing this one then:
>
> 689b097a06ba ("compiler-gcc: Suppress -Wmissing-prototypes warning for all supported GCC")
>
>    Arnd

With that patch (689b097a06ba) it builds fine.

Thanks.


      Thomas