RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Bug 1261185 - Unable to connect RHEL7.2(beta) via XDMCP, getting black screen.
Summary: Unable to connect RHEL7.2(beta) via XDMCP, getting black screen.
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: gnome-shell
Version: 7.2
Hardware: All
OS: Linux
high
high
Target Milestone: rc
: ---
Assignee: Florian Müllner
QA Contact: Desktop QE
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2015-09-08 19:59 UTC by amit yadav
Modified: 2015-10-06 15:33 UTC (History)
3 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2015-10-06 15:33:30 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
journalctl -b -a log file (140.92 KB, text/x-vhdl)
2015-09-08 20:00 UTC, amit yadav 		no flags Details
/var/log/messages and /var/log/gdm file (146.08 KB, application/x-gzip)
2015-09-08 20:00 UTC, amit yadav 		no flags Details
View All

Description amit yadav 2015-09-08 19:59:10 UTC 
Description of problem:

I have configured Xdmcp on RHEL7.2 Beta. when I try to connect this system from other RHEL/fedora system using "Xnest/Xephyr/Xorg", Sometimes I am getting black screen and sometime following error:


  "Oh no! Something has gone wrong." and "A problem has occurred and the system can't recover. Please log out and try again."

If I try to connect from Windows system using Cygwin/MobaXterm, I am getting above error.

Also getting following segfault messages in journalctl output:

Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com kernel: gnome-shell[3846]: segfault at 0 ip 00007fabf55956ac sp 00007ffc8f5eef50 error 4 in libmutter.so.0.0.0[7fabf5518000+ea000]
Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com abrt-hook-ccpp[4018]: Not saving repeating crash in '/usr/bin/gnome-shell'
Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com gnome-session[3587]: WARNING: App 'gnome-shell.desktop' respawning too quickly
Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com polkitd[682]: Unregistered Authentication Agent for unix-session:c4 (system bus name :1.82, object path /org/freedesktop/PolicyKit1/Authentic
Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com gnome-session[3587]: gnome-session[3587]: WARNING: App 'gnome-shell.desktop' respawning too quickly
Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com gnome-session[3587]: Unrecoverable failure in required component gnome-shell.desktop
Sep 09 01:15:22 dhcp234-17.gsslab.pnq.redhat.com abrt-server[3845]: Generating core_backtrace


Version-Release number of selected component (if applicable):
gnome-shell-3.14.4-26.el7.x86_64
mutter-3.14.4-11.el7.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Configure XDMCP on RHEL7.2 system
2. Try to connect from other RHEL/Fedora system using below command:

    #   Xnest -query Server_ip :3

Actual results:

 Getting black screen or error "Oh no! Something has gone wrong."

Expected results:

 Should get gnome desktop

Additional info:

 Similar issue was discussed in follwing bug : 
  https://bugzilla.redhat.com/show_bug.cgi?id=1250128
Comment 1 amit yadav 2015-09-08 20:00:07 UTC 
Created attachment 1071475 [details]
journalctl -b -a  log file
Comment 2 amit yadav 2015-09-08 20:00:52 UTC 
Created attachment 1071476 [details]
/var/log/messages and /var/log/gdm file
Comment 5 Matthias Clasen 2015-09-29 15:10:17 UTC 
I see

Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com gnome-session[3587]: gnome-session[3587]: WARNING: App 'gnome-shell.desktop' respawning too quickly
Sep 09 01:15:21 dhcp234-17.gsslab.pnq.redhat.com gnome-session[3587]: Unrecoverable failure in required component gnome-shell.desktop
Sep 09 01:15:22 dhcp234-17.gsslab.pnq.redhat.com abrt-server[3845]: Generating core_backtrace

in the logs. It would be really useful to get the coredump that abrt collected there.
Comment 6 Matthias Clasen 2015-10-05 19:19:39 UTC 
ping. Any chance to get that coredump ?
Comment 7 Michal Domonkos 2015-10-06 09:36:16 UTC 
So I can't reproduce this.

Neither with the 7.2 Beta nor with the latest nightly.  The GDM session never crashes for me and I always get the greeter when connecting with Xephyr.

With Xnest the story is a bit different as I do get the "Oh no!" screen, however it still doesn't crash.  I think the reason for that is this:

  gdm[1335]: Xlib:  extension "RANDR" missing on display "192.168.122.1:99".

which is probably expected (it also happens on 7.1) and certainly not related to this bug.

One thing that comes to mind is that maybe the reporter was using a headless machine and thus hit the bug 1243856 and bug 1241559.  That issue is already fixed so if that was the case, we can consider this one to be fixed, too.
Comment 8 Michal Domonkos 2015-10-06 09:57:16 UTC 
> machine and thus hit the bug 1243856 and bug 1241559.  That issue is already

s/1241559/1212702/
Comment 9 Matthias Clasen 2015-10-06 13:09:50 UTC 
Thanks for the retesting, Michal. If we can't reproduce, we can't fix.
Comment 10 Matthias Clasen 2015-10-06 14:25:36 UTC 
Xnest is not supported. Unless this bug reproduces with Xephyr, we can close it.
Comment 11 Michal Domonkos 2015-10-06 14:59:30 UTC 
(In reply to Matthias Clasen from comment #10)
> Xnest is not supported. Unless this bug reproduces with Xephyr, we can close
> it.

Nope, Xephyr is not affected.  Let's close.
Note You need to log in before you can comment on or make changes to this bug.