From: Alejandro Colomar <alx.manpages@gmail.com>
To: linux-man@vger.kernel.org
Cc: "Alejandro Colomar" <alx@kernel.org>, GCC <gcc@gcc.gnu.org>,
glibc <libc-alpha@sourceware.org>,
"Bastien Roucariès" <rouca@debian.org>,
"Stefan Puiu" <stefan.puiu@gmail.com>,
"Igor Sysoev" <igor@sysoev.ru>, "Rich Felker" <dalias@libc.org>,
"Andrew Clayton" <a.clayton@nginx.com>,
"Richard Biener" <richard.guenther@gmail.com>,
"Zack Weinberg" <zack@owlfolio.org>,
"Florian Weimer" <fweimer@redhat.com>,
"Joseph Myers" <joseph@codesourcery.com>,
"Jakub Jelinek" <jakub@redhat.com>,
"Eric Blake" <eblake@redhat.com>
Subject: Re: [PATCH] sockaddr.3type: BUGS: Document that libc should be fixed using a union
Date: Sun, 5 Feb 2023 16:31:30 +0100 [thread overview]
Message-ID: <f8a2f27b-9088-2dd7-79b5-b11c14fb5f1c@gmail.com> (raw)
In-Reply-To: <20230205152835.17413-1-alx@kernel.org>
[-- Attachment #1.1: Type: text/plain, Size: 947 bytes --]
Formatted version:
BUGS
sockaddr_storage was designed back when strict aliasing wasn’t a prob‐
lem. Back then, one would define a variable of that type, and then ac‐
cess it as any of the other sockaddr_* types, depending on the value of
the first member. This is Undefined Behavior. However, there is no
way to use these APIs without invoking Unedfined Behavior, either in
the user program or in libc, so it is still recommended to use this
method. The only correct way to use different types in an API is
through a union. However, that union must be implemented in the li‐
brary, since the type must be shared between the library and user code,
so libc should be fixed by implementing sockaddr_storage as a union.
--
<http://www.alejandro-colomar.es/>
GPG key fingerprint: A9348594CE31283A826FBDD8D57633D441E25BB5
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
next prev parent reply other threads:[~2023-02-05 15:31 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-05 15:28 Alejandro Colomar
2023-02-05 15:31 ` Alejandro Colomar [this message]
2023-02-06 6:02 ` Xi Ruoyao
2023-02-06 11:20 ` Rich Felker
2023-02-06 11:55 ` Alejandro Colomar
2023-02-06 13:38 ` Rich Felker
2023-02-06 14:11 ` Alejandro Colomar
2023-02-06 17:21 ` Zack Weinberg
2023-02-06 17:48 ` Rich Felker
2023-02-05 23:43 ` Rich Felker
2023-02-05 23:59 ` Alejandro Colomar
2023-02-06 0:15 ` Rich Felker
2023-02-06 18:45 ` Eric Blake
2023-02-07 1:21 ` Alejandro Colomar
2023-03-18 7:54 ` roucaries bastien
2023-03-20 10:49 ` Alejandro Colomar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=f8a2f27b-9088-2dd7-79b5-b11c14fb5f1c@gmail.com \
--to=alx.manpages@gmail.com \
--cc=a.clayton@nginx.com \
--cc=alx@kernel.org \
--cc=dalias@libc.org \
--cc=eblake@redhat.com \
--cc=fweimer@redhat.com \
--cc=gcc@gcc.gnu.org \
--cc=igor@sysoev.ru \
--cc=jakub@redhat.com \
--cc=joseph@codesourcery.com \
--cc=libc-alpha@sourceware.org \
--cc=linux-man@vger.kernel.org \
--cc=richard.guenther@gmail.com \
--cc=rouca@debian.org \
--cc=stefan.puiu@gmail.com \
--cc=zack@owlfolio.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).