All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Korsgaard <peter@korsgaard.com>
To: buildroot@busybox.net
Subject: [Buildroot] [PATCH] fs/cpio/init: unbreak ttyname_r() on glibc after dropping /dev/console exec
Date: Sat, 29 Aug 2020 15:40:53 +0200	[thread overview]
Message-ID: <87mu2din8a.fsf@dell.be.48ers.dk> (raw)
In-Reply-To: <20200829132405.GE14354@scaer> (Yann E. MORIN's message of "Sat,  29 Aug 2020 15:24:05 +0200")

>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:

Hi,

 >> +# use the /dev/console device node from devtmpfs if possible to not
 >> +# confuse glibc's ttyname_r().
 >> +# This may fail (E.G. booted with console=), and errors from exec will
 >> +# terminate the shell, so use a subshell for the test
 >> +if (exec 0</dev/console) 2>/dev/null; then
 >> +    exec 0</dev/console
 >> +    exec 1>/dev/console
 >> +    exec 2>/dev/console
 >> +fi

 > You forgot the else part, which should redirect to /dev/null, so that we
 > do have valid fds in the case /dev/console does not really exist, no?

Well, the kernel already takes care of that since commit 2bd3a997befc2
(E.G. as explained by buildroot commit 98a6f1fc02e41), so I am not sure
what explicitly reopening /dev/null would achive?

ttyname_r() / tty already returns ENOENT (not a tty) for this case
without reopening /dev/null:

tty </dev/null
not a tty

-- 
Bye, Peter Korsgaard

  reply	other threads:[~2020-08-29 13:40 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-29 13:09 [Buildroot] [PATCH] fs/cpio/init: unbreak ttyname_r() on glibc after dropping /dev/console exec Peter Korsgaard
2020-08-29 13:24 ` Yann E. MORIN
2020-08-29 13:40   ` Peter Korsgaard [this message]
2020-08-29 14:43 ` Yann E. MORIN
2020-08-29 17:40 ` Peter Korsgaard

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=87mu2din8a.fsf@dell.be.48ers.dk \
    --to=peter@korsgaard.com \
    --cc=buildroot@busybox.net \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.