netdev - Re: [PATCH net-next v2 1/4] selftests: net: Move some UAPI header inclusions after libc ones

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <4e673f7f-c49c-46b0-85b4-bae6e4efcb3a@kernel.org>
Date: Mon, 26 Jan 2026 19:13:50 +0100
From: Matthieu Baerts <matttbe@...nel.org>
To: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-api@...r.kernel.org, Arnd Bergmann <arnd@...db.de>,
 linux-kselftest@...r.kernel.org, mptcp@...ts.linux.dev,
 linux-security-module@...r.kernel.org, bpf@...r.kernel.org,
 libc-alpha@...rceware.org, Carlos O'Donell <carlos@...hat.com>,
 Adhemerval Zanella <adhemerval.zanella@...aro.org>,
 Rich Felker <dalias@...c.org>, klibc@...or.com,
 Florian Weimer <fweimer@...hat.com>, Eric Dumazet <edumazet@...gle.com>,
 Kuniyuki Iwashima <kuniyu@...gle.com>, Paolo Abeni <pabeni@...hat.com>,
 Willem de Bruijn <willemb@...gle.com>, "David S. Miller"
 <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
 Simon Horman <horms@...nel.org>, Shuah Khan <shuah@...nel.org>,
 Mat Martineau <martineau@...nel.org>, Geliang Tang <geliang@...nel.org>,
 Mickaël Salaün <mic@...ikod.net>,
 Günther Noack <gnoack@...gle.com>,
 Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>,
 Jesper Dangaard Brouer <hawk@...nel.org>,
 John Fastabend <john.fastabend@...il.com>,
 Stanislav Fomichev <sdf@...ichev.me>, Andrii Nakryiko <andrii@...nel.org>,
 Martin KaFai Lau <martin.lau@...ux.dev>, Eduard Zingerman
 <eddyz87@...il.com>, Song Liu <song@...nel.org>,
 Yonghong Song <yonghong.song@...ux.dev>, KP Singh <kpsingh@...nel.org>,
 Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>
Subject: Re: [PATCH net-next v2 1/4] selftests: net: Move some UAPI header
 inclusions after libc ones

Hi Thomas,

On 20/01/2026 15:10, Thomas Weißschuh wrote:
> Interleaving inclusions of UAPI headers and libc headers is problematic.
> Both sets of headers define conflicting symbols. To enable their
> coexistence a compatibility-mechanism is in place.
> 
> An upcoming change will define 'struct sockaddr' from linux/socket.h.
> However sys/socket.h from libc does not yet handle this case and a
> symbol conflict will arise.
> 
> Furthermore libc-compat.h evaluates the state of the libc
> inclusions only once, at the point it is included first. If another
> problematic header from libc is included later, symbol conflicts arise.
> This will trigger other duplicate definitions when linux/libc-compat.h
> is added to linux/socket.h
> 
> Move the inclusion of UAPI headers after the inclusion of the glibc
> ones, so the libc-compat.h continues to work correctly.

Thank you for looking at this!

Here is my (late, sorry) review for the modifications related to MPTCP:
> diff --git a/tools/testing/selftests/net/mptcp/mptcp_diag.c b/tools/testing/selftests/net/mptcp/mptcp_diag.c
> index 8e0b1b8d84b6..af25ebfd2915 100644
> --- a/tools/testing/selftests/net/mptcp/mptcp_diag.c
> +++ b/tools/testing/selftests/net/mptcp/mptcp_diag.c
> @@ -1,11 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /* Copyright (c) 2025, Kylin Software */
>  
> -#include <linux/sock_diag.h>
> -#include <linux/rtnetlink.h>
> -#include <linux/inet_diag.h>
> -#include <linux/netlink.h>
> -#include <linux/compiler.h>
>  #include <sys/socket.h>
>  #include <netinet/in.h>
>  #include <linux/tcp.h>

There is a remaining one (linux/tcp.h) here that you might want to move
below too.

> @@ -17,6 +12,12 @@
>  #include <errno.h>
>  #include <stdio.h>
>  
> +#include <linux/sock_diag.h>
> +#include <linux/rtnetlink.h>
> +#include <linux/inet_diag.h>
> +#include <linux/netlink.h>
> +#include <linux/compiler.h>

Note that I just noticed this is the only file from this directory where
the "includes" are not sorted by type and alphabetical order, see
pm_nl_ctl.c as an example. A bit of a detail, but if you plan to send a
v2, do you mind doing that too here while at it, please?

If not, I can look at that later, but better to avoid doing that in
parallel.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.