From: Jiri Slaby <jslaby@suse.cz>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>, LKML <linux-kernel@vger.kernel.org>
Subject: Why are not processes HUPped when they open /dev/console?
Date: Wed, 25 Jan 2012 22:38:40 +0100 [thread overview]
Message-ID: <4F207660.500@suse.cz> (raw)
Hello,
don't you remember by a chance the reason for this test in __tty_hangup:
if (filp->f_op->write != tty_write)
The logic there is not to HUP processes that have this tty open via
/dev/console.
It is there like forever. But now, due to that, processes that do
vhangup of /dev/ttyXYZ wait infinitely if there is some other process
that has the ttyXYZ open through /dev/console. (Due to infinite wait in
tty_ldisc_hangup.)
This happens on some distros on shutdown path because they do vhangup on
all tty[0-8] ttyS[01] and similar.
thanks,
--
js
suse labs
next reply other threads:[~2012-01-25 21:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-25 21:38 Jiri Slaby [this message]
2012-01-25 21:45 ` Why are not processes HUPped when they open /dev/console? Alan Cox
2012-01-26 13:15 ` Jiri Slaby
2012-02-06 19:24 ` Pavel Machek
2012-02-07 9:58 ` Jiri Slaby
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