blank screen when starting second session (tested with guest session)

[Nick Russell]

Binary package hint: gdm-guest-session

When I click Guest Session from the User Switcher applet the screen goes blank and disk activity stops.

[Nick Russell (thatnick)]

This was fixed by deleting the Guest account I created manually in Hardy.

[Martin Pitt (pitti)]

Can you please open a terminal and copy&paste the output of

  sudo sh -ex /usr/share/gdm/guest-session/guest-session-setup.sh

Thanks!

[Nick Russell (thatnick)]

This was fixed by deleting the Guest account I created manually in Hardy, but this is the output of the command you suggested:

+ USER=guest
+ PWSTAT=
+ adduser --system --no-create-home --home / --gecos Guest --group --shell /bin/bash guest
Adding system user `guest' (UID 115) ...
Adding new group `guest' (GID 128) ...
Adding new user `guest' (UID 115) with group `guest' ...
Not creating home directory `/'.
+ mktemp -td guest-home.XXXXXX
+ HOME=/tmp/guest-home.zB8114
+ mount -t tmpfs -o mode=700 none /tmp/guest-home.zB8114
+ chown guest:guest /tmp/guest-home.zB8114
+ usermod -d /tmp/guest-home.zB8114 guest
+ su guest
+ echo

+ echo guest
guest

[Qchan (ultraedge)]

I tried this already, but I still get the same issue. I'm not too sure what to do!

[Marat (marat-hotmail)]

I want to say, that I have this Problem also after a fresh install of Intrepid.
PS: In the LOW GRAPICS Modus from Ubuntu the Guest feature works like a charm.

[Robert Bernecky (bernecky)]

1. I have the same problem, and am running a dual-head config (fglrx).

2. I copied the /home partition from an Ubuntu Hardy meets the creature from Intrepid Alphas
    onto this fresh Ubuntu 8.10 release install.

3. I don't much care about the guest stuff, but wanted to switch users. That also crashes.

Output from above command is:
  sudo sh -ex /usr/share/gdm/guest-session/guest-session-setup.sh

+ USER=guest
+ PWSTAT=guest P 11/03/2008 0 99999 7 -1
+ echo guest P 11/03/2008 0 99999 7 -1
+ cut -f2 -d
+ [ P != L ]
+ echo User account guest already exists and is not locked
User account guest already exists and is not locked
+ exit 1

I am going to delete the guest account (via System/Administration/UsersAndGroups) and
readd it the same way, to see if that helps or not.

[Robert Bernecky (bernecky)]

Deleting and re-adding the guest account did not help at all - immediate crash again.

And, I probably screwed up the guest account permissions and/or password, but too bad...

[Thomas McGowan (paddy1978)]

I'm having the same problem too; selecting the 'Guest session' causes the screen to go blank and the PC becomes unresponsive. The only option is to power it off; logging in via SSH doesn't work - I can't even ping it once it locks up.

Like Robert above, I've got a dual-head setup with fglrx. I'm running a clean install of Intrepid.

[Qchan (ultraedge)]

I found the solution for me.

Click System --> Administration --> Login Window

I changed the Default session to "Gnome" That fixed it!
I hope that helps people who have the same issue (excluding the FGLRX issue)

[Robert Bernecky (bernecky)]

My system still crashes after makeing the Login Window->Gnome change.

[exactt (giesbert)]

removed the duplicate status of bug #290704 to keep track of the fglrx issue...

[Martin Pitt (pitti)]

I'll try to reproduce this with an existing account.

[Robert Bernecky (bernecky)]

My system still crashes on "switch user". I also removed the fglrx proprietary ATI drivers, rebooted,
and observed the same failure.

Gnome, AMD64 SMP box, dual-head ATI R3xxx videocard.

I'm happy to test any fault isolation ideas.

[Martin Pitt (pitti)]

I can't reproduce this. If I already have a guest user, the setup script rightfully fails:

$ sudo sh -ex /usr/share/gdm/guest-session/guest-session-setup.sh
+ USER=guest
+ PWSTAT=guest P 11/28/2008 0 99999 7 -1
+ echo+ cut -f2 -d
 guest P 11/28/2008 0 99999 7 -1
+ [ P != L ]
+ echo User account guest already exists and is not locked
User account guest already exists and is not locked
+ exit 1

If I start a guest session, X flickers for a while, and then returns back to my normal user account, with the screen locked and gnome-screensaver asking me for my password.

Nick, if you manually create a "guest" user again, do you get the behaviour above (which is intended), or does your computer freeze completely? Does ctrl+alt+f1 (try several times) still work and bring you to a text console?

[Robert Bernecky (bernecky)]

I just installed today's (2008-11-28) new patches to 8.10 Intrepid, and I still get the
crash I noted earlier:

Attempting to select another user in the "user switcher" crashes the system immediately.

One possible idea: The /home directory was imported from an earlier release,
so perhaps some files are missing, or present when they should be missing, or
permissions are wrong on something?

I'm running gnome.

[Martin Pitt (pitti)]

Okay, thanks. That's a video driver problem then, or a missing blacklist in compiz.

[Bryce Harrington (bryce)]

If it is crashing, please collect a backtrace. See http://wiki.ubuntu.com/X/Backtracing for directions.

Also, please attach your /var/log/Xorg.0.log[.old] from after reproducing the problem, as well as the output from `lspci -vvnn` and your /etc/X11/xorg.conf.

[Robert Bernecky (bernecky)]

Here's the lspci output.

[Robert Bernecky (bernecky)]

Here's Xorg.0.log.old immediately after a reboot following the crash when I attempted to
"switch users".

[Toby Bartels (tobybartels)]

I don't know if this is the same bug or not, but I have the same result (complete freeze, black screen, Ctrl-Alt-F1 doesn't work) when the Guest session /ends/. Or if I switch users, that's fine, but when I log out to return to the previous session, then it freezes.

[Bryce Harrington (bryce)]

[Still waiting on backtrace]

@Toby, if you're not sure you have the same issue, please assume you don't and file a separate bug. it's easier for us to dupe bugs than untangle a lot of unrelated "me-too's".

[Bryce Harrington (bryce)]

To everyone else commenting on this; if you are not able to resolve it by deleting your guest account, you probably have some unrelated issue and should report it separately.

[Bryce Harrington (bryce)]

We're closing this bug since it is has been some time with no response from the original reporter. However, if the issue still exists please feel free to reopen with the requested information. Also, if you could, please test against the latest development version of Ubuntu, since this confirms the bug is one we may be able to pass upstream for help.

[Robert Bernecky (bernecky)]

1. I still have the bug happening here. However:

2. I have NOT applied any new updates to my system of late, because I have a
   number of users who are dependent upon measurements (PAPI) made
   with local kernel mods that I am reluctant to reapply before the next
   Ubuntu release, scheduled for a few weeks from now.

   (Because I'll have to re-jigger my kernel mods to match the new system,
    and I screwed them up in Intrepid, so I'm delaying... --- On a side note,
    if someone can point me at directions for making local kernel mods in
    an Ubuntu-friendly manner, I'd be delighted!)

3. If there are any specific things you want to know about the crash
    (basically, with fglrx, any attempt to change user crashes the system
    hard.), please let me know, and I'll do a controlled change-user
    to pass on any useful(?) info that you need.

In summary, the bug is still present on my system, and I do not,
unless you want immediate feedback, intend to act on it until
after Jaunty is out, at which time I'll upgrade and see if anything has
changed.

[swulf (swulf)]

This bug is still present on a fresh install of Karmic (9.10) on a Lenovo W500. If you select 'Guest session' you get a blank screen, an unresponsive machine and you have to hard reboot to recover.

[pietro (per-weisteen)]

Same problem here when trying to switch to a normal account on an HP Pavilion dv2-1120eo with Karmic with latest updates and fglrx proprietary driver.

[TuxProbe (sigsgaard)]

Confirming the bug still applies.. Whenever user-change / guest-session is activated the computer deadlocks, only hard boot will make the day. I.e., all interrups are blocked - fn + key and power button has no effect.

Also, i've experienced similar problems when switching out from serial VT to VT 7/8 but beleive this has been fixed.
Same type of deadlock also occurs on occation while resuming from hibernation. This occurs, I think, when monitors connected while entering hibernation mode has been disconnected when resuming again.

Attached is the `dmesg | egrep "(irq|fglrx|acpi|pci)"` and my hardware is:

01:00.0 VGA compatible controller [0300]: ATI Technologies Inc Mobility Radeon HD 3400 Series [1002:95c4]

aticonfig --query-monitor
Error: option --query-monitor is not supported when RandR 1.2 is enabled!

aticonfig --list-adapters
* 0. 01:00.0 ATI Mobility Radeon HD 3400 Series

 aticonfig --query-connectortype=crt1
 connector type: VGA .

aticonfig --query-connectortype=lvds
 connector type: unknown .