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Date: Thu, 11 Jan 2024 00:10:24 +0100
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Thomas Voegtle" <tv@lio96.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Build error kernel/cgroup/rstat.c on v6.7-1959-gaffc5af36bbb
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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
>>> =E2=80=98bpf_rstat_flush=E2=80=99 [-Werror=3Dmissing-prototypes]
>>>   __weak noinline void bpf_rstat_flush(struct cgroup *cgrp,
>>>                        ^~~~~~~~~~~~~~~
>>>
>>>
>>> git bisects points to:
>>>
>>> commit 0fcb70851fbfea1776ae62f67c503fef8f0292b9 (refs/bisect/bad)
>>> Author: Arnd Bergmann <arnd@arndb.de>
>>> 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 a=
ll supported GCC")

    Arnd