Bug 1377987

Summary: gdm.service failed after user logout
Product: Red Hat Enterprise Linux 7 Reporter: Jiri Koten <jkoten>
Component: gdmAssignee: Ray Strode [halfline] <rstrode>
Status: CLOSED ERRATA QA Contact: Desktop QE <desktop-qa-list>
Severity: high Docs Contact:
Priority: high    
Version: 7.3CC: jkoten, lmiksik, tpelka, vbenes
Target Milestone: rcKeywords: Regression
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: gdm-3.14.2-19.el7 Doc Type: If docs needed, set a value
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Story Points: ---
Clone Of: Environment:
Last Closed: 2016-11-04 06:40:24 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
gdm log none

Description Jiri Koten 2016-09-21 09:07:11 UTC 
Description of problem:
I had two user sessions running and logout one of the users, gdm.service entered failed state and restarted itself which also brought down the remaining user session.

Version-Release number of selected component (if applicable):
gdm-3.14.2-18.el7
systemd-219-30.el7
gnome-shell-3.14.4-53.el7

How reproducible:
100%

Steps to Reproduce:
1. Login user1
2. Switch user
3. Login user2
4. Logout

Actual results:
The greeter is shown, but the user1 is not highlighted - based on the journal it lost connection to X. After login user1 I got switched to screen lock immediately and have to type the password again and unlock the screen. There is a new user1 session, i.e. I lost all the running programs. 

Expected results:
After user1 login I'm back at the previous session.

Additional info:
Comment 1 Jiri Koten 2016-09-21 09:09:28 UTC 
Created attachment 1203185 [details]
gdm log

[snip]
X Error of failed request:  BadValue (integer parameter out of range for operation)
Major opcode of failed request:  113 (X_KillClient)
Value in failed request:  0x800000
Serial number of failed request:  25
Current serial number in output stream:  278
gdm.service: main process exited, code=exited, status=1/FAILURE
Process exit status: 0

...
Unit gdm.service entered failed state.
Triggering OnFailure= dependencies of gdm.service.
gdm.service failed.
gdm.service holdoff time over, scheduling restart.
Starting GNOME Display Manager...
Comment 2 Jiri Koten 2016-09-21 12:22:57 UTC 
Regression was introduced in gdm-3.14.2-18.el7.
Comment 3 Ray Strode [halfline] 2016-09-21 14:32:43 UTC 
Not really sure what happened here… on my local branch I have:

+                gdm_error_trap_push ();
+
+                /* Kill every client but ourselves, then close our own connection
+                 */
+                for (client = 0;
+                     client <= highest_client;
+                     client += client_increment) {
+
+                        if (client != setup->resource_id_base)
+                                XKillClient (slave->priv->server_display, client);
+                }
+
+                XCloseDisplay (slave->priv->server_display);
+                gdm_error_trap_pop ();


but on the branch I committed i have:

+                /* Kill every client but ourselves, then close our own connection
+                 */
+                for (client = 0;
+                     client <= highest_client;
+                     client += client_increment) {
+
+                        if (client != setup->resource_id_base)
+                                XKillClient (slave->priv->server_display, client);
+                }
+
+                XCloseDisplay (slave->priv->server_display);


Note the missing error_trap_push/pop calls. I don't really understand how they fell out of the patch, but I clearly bungled it somehow
Comment 6 Jiri Koten 2016-09-21 15:42:46 UTC 
The issue is fixed.
Comment 8 errata-xmlrpc 2016-11-04 06:40:24 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-2451.html