Re: xterm -C and TIOCCONS vs. PRIV_TTY_CONSOLE

On Thu, Jan 6, 2011 at 8:49 PM, Craig Leres <leres_at_ee.lbl.gov> wrote:
> On 01/06/11 20:05, Garrett Cooper wrote:
>> Just to make sure we're both on the same page:
>>
>> $ grep xterm /etc/ttys
>> ttyv0 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv1 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv2 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv3 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv4 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv5 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv6 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv7 "/usr/libexec/getty Pc"         xterm   on  secure
>> ttyv8 "/usr/local/bin/xdm -nodaemon"  xterm   off secure
>
> No, that's not what mine looks like. I changed it to match and rebooted
> but it doesn't help with the TIOCCONS issue.
>
> When I run xinit, it starts up the xterm -C which does a TIOCCONS. The
> 8.1 kernel checks for PRIV_TTY_CONSOLE which isn't set and denies the
> request:
>
>        case TIOCCONS:
>                /* Set terminal as console TTY. */
>                if (*(int *)data) {
>                        error = priv_check(td, PRIV_TTY_CONSOLE);
>                        if (error)
>                                return (error);
>
>                        /*
>                         * XXX: constty should really need to be locked!
>                         * XXX: allow disconnected constty's to be stolen!
>                         */
>
>                        if (constty == tp)
>                                return (0);
>                        if (constty != NULL)
>                                return (EBUSY);
>
>                        tty_unlock(tp);
>                        constty_set(tp);
>                        tty_lock(tp);
>                } else if (constty == tp) {
>                        constty_clear();
>                }
>                return (0);
>
>
> There's nothing I see in all of /usr/src that turns on PRIV_TTY_CONSOLE
> in any case. You could rewrite the above like this:
>
>        case TIOCCONS:
>                /* Set terminal as console TTY. */
>                if (*(int *)data) {
>                        return (EPERM)
>                } else if (constty == tp) {
>                        constty_clear();
>                }
>                return (0);
>
> and it won't change any behavior.

    Ok -- figured I would ask about the obvious. I wish I could help
you further right now, but unfortunately I have a lot on my plate.
I've CCed ed_at_ and the list again so that someone else might be able to
chime in and help you further.
Cheers,
-Garrett