Locking console with Ctrl-S hangs various processes (ttydcd)

[Adrian Chadd]

Hi!

This sounds rather silly and should be fixed. Yes, hanging the vty
shouldn't hang the console device.

Would you / your friend mind filing a PR?

Thanks!


-a


On 13 May 2014 15:42, Mikhail T. <mi+thun at aldan.algebra.com> wrote:
> Hello!
>
> A fellow FreeBSD user was recently confounded by a problem: various processes on
> his 10.0 system were hanging or otherwise misbehaving: su, certain daemons, syslogd.
>
> They were all hung in the "ttydcd"-state. Searching
> <https://www.google.com/search?q=FreeBSD+ttydcd> for that revealed only, that
> other people have seen the problem, but nobody (including the entire
> freebsd-stable@ on 2012
> <http://lists.freebsd.org/pipermail/freebsd-stable/2012-June/068281.html>) was
> able to offer a solution.
>
> Apparently, the problem stems from the ttyv0 (which moonlights as /dev/console
> for the vast majority of installs) being locked -- such as by pressing Ctrl-S.
> One needs not be a root to do it...
>
> After that, any attempts to write to /dev/console -- which even syslog(3) often
> does -- would hang the calling process until the tty is unlocked (such as with
> Ctrl-Q).
>
> This may be the desired behavior for "normal" ttys, but, perhaps, /dev/console
> should act differently?
>
>     -mi
>
> _______________________________________________
> freebsd-current at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe at freebsd.org"