GDM 3.12 hangs upon switching user with Xorg 1.16
Submitted by Lorenzo B.
Link to original bug (#734776)
Description
I'm running GDM 3.12 on Arch Linux.
After the upgrade to Xorg 1.16, user switching functionality is broken. I can start a session with my main user without problems; I can also switch to another user. The problem is evident when I logout and I try to switch back to my main user. I can enter the password of my main user, but X invariably freezes thereafter. It seems to freeze just after the session for my main user is started. What I see is: I enter the password, GDM fades away as usually, and then I see a blank screen. The light of my monitor turns orange, like when it is turned off by power management systems. There is no sign of responsiveness from the keyboard (I can't, say, Ctrl+Alt+F2 to switch to another console and restart gnome). However, I can press Alt+SysRq+e to send a SIGTERM and restart my system. This is annoying as hell because I usually have several windows opened as my main user, and I lose them all.
I've created /etc/X11/Xwrapper.config with
needs_root_rights=yes allowed_users=anybody
as suggested by other Arch users, but it doesn't solve the issue for me.
These are the journal logs immediately before the problem:
Aug 14 11:45:24 aurora gdm[380]: GdmManager: trying to open reauthentication channel for user MYUSER Aug 14 11:45:24 aurora gdm[380]: GdmSession: starting conversation gdm-password Aug 14 11:45:24 aurora gdm[380]: GdmSessionWorkerJob: Starting worker... Aug 14 11:45:24 aurora gdm[380]: GdmSessionWorkerJob: Running session_worker_job process: gdm-session-worker [pam/gdm-password] /usr/lib/gdm/gdm-session-worker Aug 14 11:45:24 aurora gdm[380]: GdmSessionWorkerJob: : SessionWorkerJob on pid 4414 Aug 14 11:45:24 aurora gdm[380]: GdmDBusServer: new connection 0x7f8ef400a180 Aug 14 11:45:24 aurora gdm[380]: GdmSession: Handling new connection from worker Aug 14 11:45:24 aurora gdm[380]: GdmSession: Authenticating new connection Aug 14 11:45:24 aurora gdm[380]: GdmSession: worker connection is 0x7f8ef400a180 Aug 14 11:45:24 aurora gdm[380]: GdmSession: Emitting conversation-started signal Aug 14 11:45:24 aurora gdm[380]: GdmManager: session conversation started for service gdm-password Aug 14 11:45:24 aurora gdm[380]: GdmSession: Setting user: 'MYUSER' Aug 14 11:45:24 aurora gdm[380]: GdmSession: Beginning setup for user MYUSER Aug 14 11:45:24 aurora gdm[380]: GdmSession: looking for session file 'gnome.desktop' Aug 14 11:45:24 aurora gdm[380]: GdmSession: Conversation started Aug 14 11:45:24 aurora gdm[380]: GdmSession: looking for session file 'gnome.desktop' Aug 14 11:45:24 aurora gdm[380]: GdmSession: looking for session file 'gnome.desktop' Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: The XKEYBOARD keymap compiler (xkbcomp) reports: Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: > Warning: Compat map for group 2 redefined Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: > Using new definition Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: > Warning: Compat map for group 3 redefined Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: > Using new definition Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: > Warning: Compat map for group 4 redefined Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: > Using new definition Aug 14 11:45:25 aurora gdm-Xorg-:2[4291]: Errors from xkbcomp are not fatal to the X server Aug 14 11:45:31 aurora gdm[380]: GdmSession: looking for session file 'gnome.desktop' Aug 14 11:45:31 aurora gdm[380]: GdmSession: looking for session file 'gnome.desktop' Aug 14 11:45:31 aurora gdm-password][4414]: pam_unix(gdm-password:session): session opened for user MYUSER by (unknown)(uid=0) Aug 14 11:45:31 aurora systemd[1]: Starting Session c6 of user MYUSER. Aug 14 11:45:31 aurora systemd-logind[313]: New session c6 of user MYUSER. Aug 14 11:45:31 aurora systemd[1]: Started Session c6 of user MYUSER. Aug 14 11:45:31 aurora gdm[380]: GdmSession: Emitting 'session-opened' signal Aug 14 11:45:32 aurora gdm[380]: GdmManager: Will start session when ready Aug 14 11:45:32 aurora gdm[380]: GdmManager: start or jump to session Aug 14 11:45:32 aurora gdm[380]: Unlocking session c2 Aug 14 11:45:32 aurora gdm[380]: GdmManager: migrated: 1 Aug 14 11:45:32 aurora gdm[380]: GdmSession: Stopping all conversations Aug 14 11:45:32 aurora gdm[380]: GdmSessionWorkerJob: Stopping job pid:4414 Aug 14 11:45:32 aurora gdm[380]: GdmCommon: sending signal 15 to process 4414 Aug 14 11:45:32 aurora gdm[380]: GdmSessionWorkerJob: Waiting on process 4414 Aug 14 11:45:32 aurora gdm[380]: GdmCommon: process (pid:4414) done (status:0) Aug 14 11:45:32 aurora gdm[380]: GdmSessionWorkerJob: SessionWorkerJob died Aug 14 11:45:32 aurora gdm-Xorg-:2[4291]: (II) AIGLX: Suspending AIGLX clients for VT switch
Downgrading to Xorg 1.15 solves the issue.
I'm sorry if this bug report is not very informative, I am inexperienced with filing bug; I can provide more information if required.
Version: 3.12.x