Re: xdm will not open display

[Lance Tagliapietra <lancetag@Luminet.net>]

On Wed, Aug 17, 2005 at 04:56:01PM +0200, Geert Uytterhoeven wrote:
> On Wed, 17 Aug 2005, Lance Tagliapietra wrote:
> > My xdm.log file had the following after a boot:
> > Wed Aug 17 00:16:42 2005 xdm error (pid 2084): hung in XOpenDisplay(:0), aborting
> > Wed Aug 17 00:16:42 2005 xdm error (pid 2084): server open failed for :0, giving up
> > Wed Aug 17 00:16:42 2005 xdm error (pid 1455): display :0 cannot be opened
> > Wed Aug 17 00:16:42 2005 xdm error (pid 1455): display :0 is being disabled
> 
> So xdm failed to start the X server for display 0.
> 
> > If I run X by iteself, as root: X -ac, for example, I will get an X 
> > display and X cursor, but no log in window.
> 
> But the X server works!
> 
> So it looks like (a) xdm runs a different command to start the X server or (b)
> it runs the correct one, but passing weird parameters.
> 
> Can you check (using e.g. strace) which X server xdm tries to run? And look in
> /etc/xdm/xdm.conf.

It looks like XDM is starting the right X server, with the following 
command (see 
http://www.luminet.net/~lancetag/debian/sarge/xdminit.trace.495):

execve("/usr/X11R6/bin/X", ["/usr/X11R6/bin/X", "vt7", "-depth", "8", 
"-dpi", "100", "-auth", "/var/lib/xdm/authdir/authfiles/A"...], [/* 13 
vars */]) = 0

Looking at that file, it looks like a process is waiting for a signal 
that it never gets:
setitimer(ITIMER_REAL, {it_interval={0, 20000}, it_value={0, 20000}}, 
NULL) = 0
--- SIGALRM (Alarm clock) @ 0 (0) ---
sigreturn( <unfinished ...>
--- SIGALRM (Alarm clock) @ 0 (0) ---
<... sigreturn resumed> )               = ? (mask now [INT QUIT ILL])
--- SIGALRM (Alarm clock) @ 0 (0) ---
sigreturn( <unfinished ...>
--- SIGALRM (Alarm clock) @ 0 (0) ---
<... sigreturn resumed> )               = ? (mask now [INT QUIT ILL])

I have re-run with the --debug option set to 255, I'll be posting the 
trace files from that boot shortly.  I'm hoping to find additional info 
in the log file as to why the :0 could not be opened.

I still have a suspicion that there is a second, but related problem 
here, as I connot log on via my X terminal as a normal user, but I can 
log on as root user via the login window that xdm generates on that 
machine.  Does anyone else log in to their m68k box with a remote X 
terminal?

Thanks,

--Lance

> 
> Gr{oetje,eeting}s,
> 
> 						Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org