From: Rich Felker <dalias@libc.org>
To: Florian Weimer <fweimer@redhat.com>
Cc: bug-coreutils@gnu.org, musl@lists.openwall.com
Subject: Re: [musl] coreutils cp mishandles error return from lchmod
Date: Wed, 22 Jan 2020 09:42:43 -0500 [thread overview]
Message-ID: <20200122144243.GZ30412@brightrain.aerifal.cx> (raw)
In-Reply-To: <87ftg7k1at.fsf@oldenburg2.str.redhat.com>
On Wed, Jan 22, 2020 at 03:34:18PM +0100, Florian Weimer wrote:
> * Rich Felker:
>
> > coreutils should be opting to use the system-provided lchmod, which is
> > safe, and correctly handling error returns (silently treating
> > EOPNOTSUPP as success) rather than as hard errors.
>
> glibc's lchmod always returns ENOSYS (except on Hurd). I don't know how
> lchmod is used in coreutils, but I suspect it is not particularly
> useful.
When preserving permissions (cp -p, archive extraction, etc.), you
want lchmod to work correctly just for the purpose of *not* following
the link and thereby unwantedly changing the permissions of the link
target. But, fchmodat with AT_SYMLINK_NOFOLLOW works just as well and
is standard, and that's really what coreutils should be using.
Rich
next prev parent reply other threads:[~2020-01-22 14:43 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-22 14:15 Rich Felker
2020-01-22 14:34 ` Florian Weimer
2020-01-22 14:42 ` Rich Felker [this message]
2020-01-22 15:08 ` Florian Weimer
2020-01-22 15:15 ` Rich Felker
2020-01-22 15:32 ` Florian Weimer
2020-01-22 16:07 ` Rich Felker
2020-01-22 16:19 ` Florian Weimer
2020-01-22 17:15 ` Rich Felker
2020-01-22 20:48 ` Florian Weimer
2020-01-22 20:56 ` Rich Felker
2020-01-22 21:05 ` Florian Weimer
2020-01-22 21:55 ` bug#39236: " Paul Eggert
2020-01-22 22:05 ` Rich Felker
2020-02-08 0:37 ` Paul Eggert
2020-02-12 11:50 ` Florian Weimer
2020-02-12 13:05 ` Rich Felker
2020-02-12 19:07 ` Rich Felker
2020-02-12 19:13 ` Florian Weimer
2020-02-12 19:59 ` A. Wilcox
2020-02-12 20:56 ` Rich Felker
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=20200122144243.GZ30412@brightrain.aerifal.cx \
--to=dalias@libc.org \
--cc=bug-coreutils@gnu.org \
--cc=fweimer@redhat.com \
--cc=musl@lists.openwall.com \
/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.
Code repositories for project(s) associated with this public inbox
https://git.vuxu.org/mirror/musl/
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 NNTP newsgroup(s).