Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7;
MIME-Version: 1.0
References: <20231031-tcp-ao-fix-label-in-compound-statement-warning-v1-1-c9731d115f17@kernel.org>
 <ZUStrQCqBjBBB6dc@infradead.org>
In-Reply-To: <ZUStrQCqBjBBB6dc@infradead.org>
From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Fri, 3 Nov 2023 09:57:17 -0700
Message-ID: <CAKwvOd=voKM+kPWa=toFfWDvq2gOw7Q0yyjq7ragxmPS7U5HBQ@mail.gmail.com>
Subject: Re: [PATCH net] tcp: Fix -Wc23-extensions in tcp_options_write()
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Nathan Chancellor <nathan@kernel.org>, edumazet@google.com,
        davem@davemloft.net, dsahern@kernel.org, kuba@kernel.org,
        pabeni@redhat.com, trix@redhat.com, 0x7f454c46@gmail.com,
        fruggeri@arista.com, noureddine@arista.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        patches@lists.linux.dev,
        Thorsten Leemhuis <regressions@leemhuis.info>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Fri, Nov 3, 2023 at 1:22=E2=80=AFAM Christoph Hellwig <hch@infradead.org=
> wrote:
>
> On Tue, Oct 31, 2023 at 01:23:35PM -0700, Nathan Chancellor wrote:
> > Clang warns (or errors with CONFIG_WERROR=3Dy) when CONFIG_TCP_AO is se=
t:
> >
> >   net/ipv4/tcp_output.c:663:2: error: label at end of compound statemen=
t is a C23 extension [-Werror,-Wc23-extensions]
> >     663 |         }
> >         |         ^
> >   1 error generated.
> >
> > On earlier releases (such as clang-11, the current minimum supported
> > version for building the kernel) that do not support C23, this was a
> > hard error unconditionally:
> >
> >   net/ipv4/tcp_output.c:663:2: error: expected statement
> >           }
> >           ^
> >   1 error generated.
> >
> > Add a semicolon after the label to create an empty statement, which
> > resolves the warning or error for all compilers.
>
> Can you please just split the A0 handlig into a separate helper, which
> shuld make the whole thing a lot cleaner?

Just a note; mainline is currently red over this for us since
1e03d32bea8e spent all of ~3 days in linux-next before getting merged
into mainline.

Whatever the fix is, it would be great to get it into mainline ASAP.

--=20
Thanks,
~Nick Desaulniers