From: Jiri Slaby <jslaby@suse.cz>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Greg KH <greg@kroah.com>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: Why are not processes HUPped when they open /dev/console?
Date: Thu, 26 Jan 2012 14:15:41 +0100 [thread overview]
Message-ID: <4F2151FD.4050101@suse.cz> (raw)
In-Reply-To: <20120125214522.7a49cf39@pyramind.ukuu.org.uk>
On 01/25/2012 10:45 PM, Alan Cox wrote:
> On Wed, 25 Jan 2012 22:38:40 +0100
> Jiri Slaby <jslaby@suse.cz> wrote:
>
>> 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.
>
> Because if you hang up the console the machine crashes ?
>
> At least that's what used to happen.
It does not crash anymore. However the system (systemd more precisely)
is confused a bit (well, a huge). So I suppose the test has its meaning.
The whole exercise was about how to fix the userspace issue introduced
by the added infinite timeout.
I think the proper solution here is just not to call vhangup in
userspace for the device which is /dev/console. It never worked anyway.
Because the HUP signal was never sent and it always timed out.
thanks,
--
js
suse labs
next prev parent reply other threads:[~2012-01-26 13:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-25 21:38 Why are not processes HUPped when they open /dev/console? Jiri Slaby
2012-01-25 21:45 ` Alan Cox
2012-01-26 13:15 ` Jiri Slaby [this message]
2012-02-06 19:24 ` Pavel Machek
2012-02-07 9:58 ` Jiri Slaby
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