linux-kernel - [PATCH 0/7] Replace "__auto

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-next>] [day] [month] [year] [list]

Message-ID: <20250718213252.2384177-1-hpa@zytor.com>
Date: Fri, 18 Jul 2025 14:32:43 -0700
From: "H. Peter Anvin" <hpa@...or.com>
To: 
Cc: "H. Peter Anvin" <hpa@...or.com>,
        Eugenio Pérez <eperezma@...hat.com>,
        Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Al Viro <viro@...iv.linux.org.uk>, Alexei Starovoitov <ast@...nel.org>,
        Alexey Dobriyan <adobriyan@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Andrii Nakryiko <andrii@...nel.org>, Arnd Bergmann <arnd@...nel.org>,
        Borislav Petkov <bp@...en8.de>, Cong Wang <cong.wang@...edance.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Daniel Borkmann <daniel@...earbox.net>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        David Laight <David.Laight@...LAB.COM>,
        David Lechner <dlechner@...libre.com>,
        Dinh Nguyen <dinguyen@...nel.org>,
        Eduard Zingerman <eddyz87@...il.com>,
        Gatlin Newhouse <gatlin.newhouse@...il.com>,
        Hao Luo <haoluo@...gle.com>, Ingo Molnar <mingo@...hat.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Jakub Sitnicki <jakub@...udflare.com>,
        Jan Hendrik Farr <kernel@...rr.cc>, Jason Wang <jasowang@...hat.com>,
        Jiri Olsa <jolsa@...nel.org>,
        John Fastabend <john.fastabend@...il.com>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        Josh Poimboeuf <jpoimboe@...nel.org>, KP Singh <kpsingh@...nel.org>,
        Kees Cook <kees@...nel.org>,
        Luc Van Oostenryck <luc.vanoostenryck@...il.com>,
        Marc Herbert <Marc.Herbert@...ux.intel.com>,
        Martin KaFai Lau <martin.lau@...ux.dev>,
        Mateusz Guzik <mjguzik@...il.com>, Michal Luczaj <mhal@...x.co>,
        Miguel Ojeda <ojeda@...nel.org>, Mykola Lysenko <mykolal@...com>,
        NeilBrown <neil@...wn.name>, Peter Zijlstra <peterz@...radead.org>,
        Przemek Kitszel <przemyslaw.kitszel@...el.com>,
        Sami Tolvanen <samitolvanen@...gle.com>, Shuah Khan <shuah@...nel.org>,
        Song Liu <song@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>,
        Thomas Gleixner <tglx@...utronix.de>,
        Thorsten Blum <thorsten.blum@...ux.dev>,
        Uros Bizjak <ubizjak@...il.com>,
        Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
        Yafang Shao <laoar.shao@...il.com>, Ye Bin <yebin10@...wei.com>,
        Yonghong Song <yonghong.song@...ux.dev>,
        Yufeng Wang <wangyufeng@...inos.cn>, bpf@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-kselftest@...r.kernel.org, linux-sparse@...r.kernel.org,
        virtualization@...ts.linux.dev, x86@...nel.org
Subject: [PATCH 0/7] Replace "__auto_type" with "auto"

"auto" was defined as a keyword back in the K&R days, but as a storage
type specifier.  No one ever used it, since it was and is the default
storage type for local variables.

C++11 recycled the keyword to allow a type to be declared based on the
type of an initializer.  This was finally adopted into standard C in
C23.

gcc and clang provide the "__auto_type" alias keyword as an extension
for pre-C23, however, there is no reason to pollute the bulk of the
source base with this temporary keyword; instead define "auto" as a
macro unless the compiler is running in C23+ mode.

This macro is added in <linux/compiler_types.h> because that header is
included in some of the tools headers, wheres <linux/compiler.h> is
not as it has a bunch of very kernel-specific things in it.

--- 
 arch/nios2/include/asm/uaccess.h                        |  4 ++--
 arch/x86/include/asm/bug.h                              |  2 +-
 arch/x86/include/asm/string_64.h                        |  6 +++---
 arch/x86/include/asm/uaccess_64.h                       |  2 +-
 fs/proc/inode.c                                         | 16 ++++++++--------
 include/linux/cleanup.h                                 |  4 ++--
 include/linux/compiler.h                                |  2 +-
 include/linux/compiler_types.h                          | 13 +++++++++++++
 include/linux/minmax.h                                  |  6 +++---
 tools/testing/selftests/bpf/prog_tests/socket_helpers.h |  9 +++++++--
 tools/virtio/linux/compiler.h                           |  2 +-
 11 files changed, 42 insertions(+), 24 deletions(-)