Session crashed on reconnect

[PKizzle]

When reconnecting to a xorgxrdp session running on Ubuntu 16.04 with X.Org X Server version 1.18.4 the session tries to load (cursor and blue background) but crashes after a few seconds. This might be related to multi-monitor usage.

This is the xrdp-sesman log file:

[20180606-09:28:22] [DEBUG] Closed socket 7 (AF_INET6 ::1 port 3350)
[20180606-09:28:47] [CORE ] window manager (pid 17699) did exit, cleaning up session
[20180606-09:28:47] [INFO ] calling auth_stop_session and auth_end from pid 17696

xorgxrdp log file:

(This first message below appears many more times above)
[1576949.121] rdpRRCrtcSetGamma:
[1576949.121] rdpRRCrtcSetGamma:
[1576949.137] rdpRRCrtcSetGamma:
[1576949.137] rdpRRCrtcSetGamma:
[1576949.137] rdpRRCrtcSetGamma:
[1576949.153] rdpRRCrtcSetGamma:
[1576949.153] rdpRRCrtcSetGamma:
[1576949.153] rdpRRCrtcSetGamma:
[1576949.169] rdpRRCrtcSetGamma:
[1576949.169] rdpRRCrtcSetGamma:
[1576949.169] rdpRRCrtcSetGamma:
[1576949.185] rdpRRCrtcSetGamma:
[1576949.185] rdpRRCrtcSetGamma:
[1576949.186] rdpRRCrtcSetGamma:
[1576949.201] rdpRRCrtcSetGamma:
[1576949.202] rdpRRCrtcSetGamma:
[1576949.202] rdpRRCrtcSetGamma:
[1576949.218] rdpRRCrtcSetGamma:
[1576949.218] rdpRRCrtcSetGamma:
[1576949.218] rdpRRCrtcSetGamma:
[1576951.461] rdpRRCrtcSetGamma:
[1576951.462] rdpRRCrtcSetGamma:
[1576951.462] rdpRRCrtcSetGamma:
[1579730.004] rdpClientConRecv: g_sck_recv failed(returned -1)
[1579730.004] rdpClientConDisconnect:
[1579730.005] rdpClientConDisconnect: clientCon removed from dev list
[1579730.005] rdpClientConRecvMsg: error
[1579730.005] rdpClientConCheck: rdpClientConGotData failed
[1631654.122] rdpClientConGotConnection:
[1631654.148] rdpClientConGotConnection: g_sck_accept ok new_sck 49
[1631654.148] rdpClientConGotConnection: adding only clientCon
[1631654.175] rdpClientConProcessMsgVersion: version 0 0 0 1
[1631654.175] rdpClientConProcessScreenSizeMsg: set width 5440 height 1080 bpp 24
[1631654.175] rdpClientConProcessScreenSizeMsg: shmemid 1800732876 shmemptr 0x7fe42dcf7000
[1631654.175] rdpClientConProcessMsgClientInput: invalidate x 0 y 0 cx 5440 cy 1080
[1631654.230] rdpClientConProcessMsgClientInfo:
[1631654.230]   got client info bytes 5744
[1631654.230]   jpeg support 0
[1631654.230]   offscreen support 1
[1631654.230]   offscreen size 10485760
[1631654.230]   offscreen entries 100
[1631654.230]   client can not do offscreen to offscreen blits
[1631654.230]   client can do new(color) cursor
[1631654.230]   client can do multimon
[1631654.230]   client monitor data, monitorCount=3
[1631654.230]     left 3840 top 180 right 5439 bottom 1079
[1631654.230]     left 1920 top 0 right 3839 bottom 1079
[1631654.230]     left 0 top 0 right 1919 bottom 1079
[1631654.230] rdpRRSetRdpOutputs: numCrtcs 3 monitorCount 3
[1631654.230] rdpRRSetRdpOutputs: update output 0 left 3840 top 180 width 1600 height 900
[1631654.231] rdpRRSetRdpOutputs: update output 1 left 1920 top 0 width 1920 height 1080
[1631654.967] (EE) 
[1631654.967] (EE) Backtrace:
[1631655.181] (EE) 0: /usr/lib/xorg/Xorg (xorg_backtrace+0x4e) [0x55a76414f6ce]
[1631655.181] (EE) 1: /usr/lib/xorg/Xorg (0x55a763f9d000+0x1b6a69) [0x55a764153a69]
[1631655.181] (EE) 2: /lib/x86_64-linux-gnu/libc.so.6 (0x7fe43d1f5000+0x354b0) [0x7fe43d22a4b0]
[1631655.182] (EE) 3: /usr/lib/xorg/Xorg (RRCrtcNotify+0x74) [0x55a7640b1934]
[1631655.182] (EE) 4: /usr/lib/xorg/modules/libxorgxrdp.so (0x7fe438468000+0x851e) [0x7fe43847051e]
[1631655.182] (EE) 5: /usr/lib/xorg/modules/libxorgxrdp.so (rdpRRSetRdpOutputs+0xe3) [0x7fe438470f73]
[1631655.182] (EE) 6: /usr/lib/xorg/modules/libxorgxrdp.so (rdpClientConCheck+0xc6b) [0x7fe4384750db]
[1631655.182] (EE) 7: /usr/lib/xorg/Xorg (WakeupHandler+0x6d) [0x55a763ff599d]
[1631655.182] (EE) 8: /usr/lib/xorg/Xorg (WaitForSomething+0x1ef) [0x55a76414c40f]
[1631655.182] (EE) 9: /usr/lib/xorg/Xorg (0x55a763f9d000+0x53bce) [0x55a763ff0bce]
[1631655.182] (EE) 10: /usr/lib/xorg/Xorg (0x55a763f9d000+0x57e13) [0x55a763ff4e13]
[1631655.183] (EE) 11: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf0) [0x7fe43d215830]
[1631655.183] (EE) 12: /usr/lib/xorg/Xorg (_start+0x29) [0x55a763fdf069]
[1631655.183] (EE) 
[1631655.183] (EE) Segmentation fault at address 0x55a77d91e000
[1631655.183] (EE) 
Fatal server error:
[1631655.183] (EE) Caught signal 11 (Segmentation fault). Server aborting
[1631655.184] (EE) 
[1631655.184] (EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
[1631655.184] (EE) Please also check the log file at ".xorgxrdp.24.log" for additional information.
[1631655.184] (EE) 
[1631655.184] rdpmouseControl: what 4
[1631655.184] rdpkeybControl: what 4
[1631655.191] rdpLeaveVT:
[1631655.194] (EE) Server terminated with error (1). Closing log file.

**And the following info can be found in the syslog file:**
Jun  6 09:28:22 xrdp-sesman: pam_ecryptfs: pam_sm_authenticate: /home/<user> is already mounted
Jun  6 09:28:41 org.gnome.gedit[17732]: (gedit:12498): Gdk-WARNING **: gedit: Fatal IO error 11 (Resource temporarily unavailable) on X server :24.0.
Jun  6 09:28:41 org.mate.panel.applet.WnckletFactory[17732]: wnck-applet: Fatal IO error 11 (Resource temporarily unavailable) on X server :24.0.
Jun  6 09:28:41 org.mate.panel.applet.TrashAppletFactory[17732]: trashapplet: Fatal IO error 11 (Resource temporarily unavailable) on X server :24.0.
Jun  6 09:28:41 org.mate.panel.applet.NotificationAreaAppletFactory[17732]: notification-area-applet: Fatal IO error 11 (Resource temporarily unavailable) on X server :24.0.
Jun  6 09:28:41 org.a11y.atspi.Registry[17797]: XIO:  fatal IO error 11 (Resource temporarily unavailable) on X server ":24.0"
Jun  6 09:28:41 org.a11y.atspi.Registry[17797]:       after 91521 requests (91521 known processed) with 0 events remaining.
Jun  6 09:28:41 org.mate.panel.applet.ClockAppletFactory[17732]: clock-applet: Fatal IO error 11 (Resource temporarily unavailable) on X server :24.0.
Jun  6 09:28:43 org.gtk.vfs.Daemon[17732]: A connection to the bus can't be made
Jun  6 09:28:43 org.gtk.vfs.Daemon[17732]: A connection to the bus can't be made
Jun  6 09:28:44 org.gtk.vfs.Daemon[17732]: A connection to the bus can't be made
Jun  6 09:28:45 ntpd[2122]: error resolving pool 1.ubuntu.pool.ntp.org: Name or service not known (-2)
Jun  6 09:28:45 org.gnome.zeitgeist.Engine[17732]: #033[31m[07:28:45.817015 WARNING]#033[0m zeitgeist-daemon.vala:449: The connection is closed
Jun  6 09:28:46 org.gnome.zeitgeist.Engine[17732]: #033[34m[07:38:58.773936 MESSAGE]#033[0m extension-collection.vala:123: Skipping SearchEngine (disabled)
Jun  6 09:28:47 gnome-session[17699]: Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Jun  6 09:28:47 gnome-session[17699]: Unable to init server: Could not connect: Connection refused
Jun  6 09:28:47 gnome-session[17699]: (gnome-session-check-accelerated:27376): Gtk-WARNING **: cannot open display: :24.0
Jun  6 09:28:47 gnome-session[17699]: Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Jun  6 09:28:47 gnome-session[17699]: Unable to init server: Could not connect: Connection refused
Jun  6 09:28:47 gnome-session[17699]: (gnome-session-check-accelerated:27377): Gtk-WARNING **: cannot open display: :24.0
Jun  6 09:28:47 gnome-session[17699]: gnome-session-binary[17699]: WARNING: software acceleration check failed: Child process exited with code 1
Jun  6 09:28:47 gnome-session[17699]: gnome-session-binary[17699]: CRITICAL: We failed, but the fail whale is dead. Sorry....
Jun  6 09:28:47 gnome-session-binary[17699]: WARNING: software acceleration check failed: Child process exited with code 1
Jun  6 09:28:47 gnome-session-binary[17699]: CRITICAL: We failed, but the fail whale is dead. Sorry....

[PKizzle]

I forgot to include the xrdp version. Currently I am using version 0.9.5

[metalefty]

It seems you have 3 monitors. Can you confirm if it crashes with fewer monitors?
I suspect it might be a bug when you have more than 2 monitors.

[1631654.230]   client monitor data, monitorCount=3

[PKizzle]

Now I am trying to use only 2 monitors.
Could you find any hint in the log files what exactly causes the problem?
Sadly xorg-xrdp sessions crash regularly when trying to reconnect (every second day). If necessary I can provide more log files of the crashes.

[PKizzle]

Ok I asked someone who is using only 2 monitors for some time now, but his sessions also crash. His log files are identical to mine. No differences.

[PKizzle]

Inside .xsession-errors I get the following additional information:

openConnection: connect: No such file or directory
cannot connect to brltty at :0

[matt335672]

@PKizzle - could I just ask where the xorgxrdp package you've used with Ubuntu 16.04 has come from? There doesn't appear to be an official package for xorgxrdp for Xenial.

Also, is your X server from xserver-xorg-core_1.18.4-0ubuntu0.7_amd64.deb?

Reading up the stacktrace, it looks OK until frame 3:. RRCrtcNotify+0x74 does not correspond to a function return address for this version of Xorg. So something odd seems to have happened while execution is within the libxorgxrdp.so module.

[PKizzle]

I compiled xorgxrdp for Ubuntu 16.04 amd64 myself without any noticeable error messages and packaged it to be installed on other Ubuntu servers.

xorgxrdp was installed via apt from the hermlnx PPA, previously I was using x11rdp which was built via the X11RDP-o-Matic build script.

And this is the output of the installed xserver-xorg packages on the system.

XSERVER
ii  x11-xserver-utils                          7.7+7                                        amd64        X server utilities
ii  xserver-common                             2:1.18.4-0ubuntu0.7                          all          common files used by various X servers
ii  xserver-xorg                               1:7.7+13ubuntu3                              amd64        X.Org X server
ii  xserver-xorg-core                          2:1.18.4-0ubuntu0.7                          amd64        Xorg X server - core server
rc  xserver-xorg-core-hwe-16.04                2:1.19.5-0ubuntu2~16.04.1                    amd64        Xorg X server - core server
ii  xserver-xorg-dev                           2:1.18.4-0ubuntu0.7                          amd64        Xorg X server - development files
rc  xserver-xorg-hwe-16.04                     1:7.7+16ubuntu3~16.04.1                      amd64        X.Org X server
ii  xserver-xorg-input-all                     1:7.7+13ubuntu3                              amd64        X.Org X server -- input driver metapackage
ii  xserver-xorg-input-evdev                   1:2.10.1-1ubuntu2                            amd64        X.Org X server -- evdev input driver
ii  xserver-xorg-input-synaptics               1.8.2-1ubuntu3                               amd64        Synaptics TouchPad driver for X.Org server
ii  xserver-xorg-input-vmmouse                 1:13.1.0-1ubuntu2                            amd64        X.Org X server -- VMMouse input driver to use with VMWare
ii  xserver-xorg-input-wacom                   1:0.32.0-0ubuntu3                            amd64        X.Org X server -- Wacom input driver
ii  xserver-xorg-legacy-hwe-16.04              2:1.19.5-0ubuntu2~16.04.1                    amd64        setuid root Xorg server wrapper
rc  xserver-xorg-video-intel-hwe-16.04         2:2.99.917+git20170309-0ubuntu1~16.04.1      amd64        X.Org X server -- Intel i8xx, i9xx display driver
 
XORG
ii  xorg                                       1:7.7+13ubuntu3                              amd64        X.Org X Window System
ii  xorg-docs-core                             1:1.7.1-1ubuntu1                             all          Core documentation for the X.org X Window System
ii  xorg-sgml-doctools                         1:1.11-1                                     all          Common tools for building X.Org SGML documentation
ii  xorgxrdp                                   0.9.4-1ppa1                                  amd64        Remote Desktop Protocol (RDP) modules for X.org®

[PKizzle]

Looking around whether other users were experiencing the same issue, I found the following issue on the xrdp page: neutrinolabs/xrdp#1164
But since there is no log file attached I'm not sure whether xorgxrdp or x11rdp was used.

[matt335672]

That's useful - thanks. I know now I've got the right Xorg binary.

I may be able to make sense of the rest of the crashdump if I can find debug information for the xorgxrdp module.

According to your version list you're running xorgxrdp from a PPA. Do you have the information in that PPA to hand?

[PKizzle]

Oh I found the PPA it's this one: https://launchpad.net/~hermlnx/+archive/ubuntu/xrdp

[matt335672]

I've had a look in the PPA.
Both the backport and the debian bionic package wrap a version of xrdp and xorgxrdp together, which makes it a bit awkward to determine the version of xorgxrdp in use. However, it seems the backport uses xorgxrdp 0.2.4.

The PPA doesn't contain any debug info. This can be recreated, but it's a fiddle.

After re-reading your report, I'm now a bit confused. As well as the PPA being installed you mention you've rebuilt and packaged xorgxrdp yourself. So there's potentially two modules on the system.

A few more questions:-

• Are you running the one you've packaged, or the PPA one?
• Did you use a .deb for the packaging or use some other method?
• Do you have debug info available?

Apologies for missing the rebuild bit before.

[PKizzle]

I added hermlnx-ubuntu-xrdp-xenial.list to /etc/apt/sources.list.d did an apt update and then installed the package via aptitude. The self built package was x11rdp using the X11RDP-o-Matic build script, so not xorgxrdp. (I will edit my wrong comment on that above). Since I am only using the back port version from hermlnx apart from the provided log files, I do not have any other debug information.

[matt335672]

That's a good description - thanks. I'm pretty clear on where we are now.

When I get a chance I'll build a Xenial VM and attempt to reconstruct the debug info. In the meantime, I suggest you have a look at what it would take to back-port and rebuild the combined xrdp/xorgxrdp package yourself. The reason I say this is that one of these two scenarios is quite likely I think:-

• Despite the debug info I still can't work out what's happened
• If I do work out what's happened, you might need to try a patch anyway.

You'll also remove a dependency on a PPA which may no longer be maintained.

It should be pretty straightforward to build the packages. Essentially you just download the sources from https://packages.ubuntu.com/bionic/xrdp, and follow the instructions at https://www.debian.org/doc/manuals/maint-guide/build.en.html for building a package.

Hope that makes sense.

[matt335672]

I've managed to create a debug package with a Xenial VM.

Sadly, I'm still unable to tell what might be causing this.

The stack frames of interest in the trace (in reverse order) are:-

6: /usr/lib/xorg/modules/libxorgxrdp.so (rdpClientConCheck+0xc6b) [0x7fe4384750db]
5: /usr/lib/xorg/modules/libxorgxrdp.so (rdpRRSetRdpOutputs+0xe3) [0x7fe438470f73]
4: /usr/lib/xorg/modules/libxorgxrdp.so (0x7fe438468000+0x851e) [0x7fe43847051e]
3: /usr/lib/xorg/Xorg (RRCrtcNotify+0x74) [0x55a7640b1934]

The address in stack frame 6 refers to the call to rdpRRSetRdpOutputs in source line rdpClientCon.c:912. The address is stack frame 5 refers to the call to rdpRRUpdateOutput in source line
rdpRandR.c:515.
After that it gets a bit strange. The address in stack frame 4 looks like it corresponds to the call to RRCrtcNotify at source line rdpRandR.c:422, but strangely its value is one larger than it should be. Then the address in stack frame 3 makes no sense at all - it doesn't seem to correspond to a call instruction.

The logging is also consistent with rdpRRUpdateOutput being called for the second monitor (i.e. output 1) but never returning from this for the call to output 2.

I'm at a loss to know what to suggest at this point. A later version of xorgxrdp might be worth trying, but I can't see that any significant changes to this area have happened since 0.2.4. I don't know enough about X server internals to take this any further without more information.

Could this maybe be application or desktop related? Does the problem occur if you log in, disconnect immediately and then reconnect?

[PKizzle]

This problem does not occur on every re-login. Crashes occur when the session is alive for a long time without being used (over night). If the session is left open for too long the connection is automatically closed (is this a bug or a feature?), but that has no influence whether the session can be reused or not. It does not seem to be application related, since everyone connecting to this machine using RDP has these problems and uses different applications. The only applications running for each session are mate, VirtualGL, Xorg and xrdp.