Segfault in OsLookupColor+0x139 during attempt to build a 2 display Xdmx multihead
Submitted by Florian Mayer
Assigned to dmx..@..op.org
Link to original bug (#100404)
Description
Created attachment 130470 Full output of the startx command
((INTRO I'm getting the following segfault when trying to create a multihead configuration over my local network using Xdmx (detailed problem description below)
(EE) Backtrace: (EE) 0: /usr/sbin/Xdmx (OsLookupColor+0x139) [0x5586f9] (EE) 1: /usr/lib/libpthread.so.0 (__restore_rt+0x0) [0x7f162ef91fdf] (EE) 2: /usr/sbin/Xdmx (TimerForce+0x10) [0x552180] (EE) 3: /usr/sbin/Xdmx (RemoveInputDeviceTraces+0x5211) [0x433bc1] (EE) 4: /usr/sbin/Xdmx (_start+0x4513) [0x4251e3] (EE) 5: /usr/sbin/Xdmx (RemoveInputDeviceTraces+0x41aa) [0x431ada] (EE) 6: /usr/sbin/Xdmx (RemoveInputDeviceTraces+0x460b) [0x4321bb] (EE) 7: /usr/sbin/Xdmx (AddScreen+0xd7) [0x51de37] (EE) 8: /usr/sbin/Xdmx (InitOutput+0x406) [0x428966] (EE) 9: /usr/sbin/Xdmx (InitFonts+0x216) [0x5219d6] (EE) 10: /usr/lib/libc.so.6 (__libc_start_main+0xf1) [0x7f162ebfc511] (EE) 11: /usr/sbin/Xdmx (_start+0x2a) [0x41c8ca] (EE) 12: ? (?+0x2a) [0x2a]
((THE CURRENT CONFIGURATION:
(II) dmx: Generation: 1 (II) dmx: DMX version: 1.2.20070424 (DMX Project) (II) dmx: DMX Build OS: Linux 4.9.11-1-ARCH x86_64 () (II) dmx: DMX Build Compiler: gcc 6.3.1 (II) dmx: DMX Execution OS: Linux 4.10.5-1-ARCH #1 (closed) SMP PREEMPT Wed Mar 22 14:42:03 CET 2017 (II) dmx: DMX Execution Host: kurerm (II) dmx: MAXSCREENS: 16 (II) dmx: Using configuration from command line (II) dmx: Added :0 at 0 0 (II) dmx: Added 192.168.2.148:0 right of :0 (II) dmx[o0/:0]: No Xdmx server running on backend (II) dmx[o0/:0]: Name of display: :0 (II) dmx[o0/:0]: Version number: 11.0 (II) dmx[o0/:0]: Vendor string: The X.Org Foundation (II) dmx[o0/:0]: Vendor release: 11903000 (II) dmx[o0/:0]: Dimensions: 1440x900 pixels (II) dmx[o0/:0]: 7 depths on screen 0: 24,1,4,8,15,16,32 (II) dmx[o0/:0]: Depth of root window: 24 planes (24) (II) dmx[o0/:0]: Number of colormaps: 1 min, 1 max (II) dmx[o0/:0]: Options: backing-store when mapped, save-unders no (II) dmx[o0/:0]: Window Manager running: yes (**) dmx[o0/:0]: Window manager running -- colormaps not supported
((STEPS TO REPRODUCTION.
- On machine S
- $ xinit
which twm
--which X
-listen tcp - open xterm
- make sure port 6000 is open ($ nmap localhost)
- $ xhost +
- $ xinit
On machine M
- login to usual X session (using lightdm in my case)
- open terminal
- make sure X server on S is reachable (xterm -display ip_of_S:0)
- $ startx
which twm
--which Xdmx
-display :0 -display 192.168.2.148:0
The same steps are valid for reproduction between two arch linux computers.
((FURTHER INFO
I tried this under two different hardware setups.
-
Two VMs
-
One VM and one physical computer
-
I downloaded http://www.osboxes.org/arch-linux/ and created a base vm where I installed all necessary Xorg components (the packages xorg-server xorg-server-utils, xorg-utils etc.). When I successfully tested a basic twm session I cloned the VM and edited both so that each one posessed its own hostname. Both were configured to use DHCP(v4) in my network. Then I started both VMs and made sure they had different IPs. And finally I did exactly the steps that I described above. Of course, leading to the same result.
-
see steps to reproduce
((MAYBE RELATED
If I do $ Xorg :0 -configure while no instance of the X server is running, I'll get a similar backtrace caused by a similar segfault with OsLookupColor+0x132 being on top of the callstack. Here the message's content:
X.Org X Server 1.19.3 Release Date: 2017-03-15 X Protocol Version 11, Revision 0 Build Operating System: Linux 4.9.11-1-ARCH i686 Current Operating System: Linux testarsch1 4.10.5-1-ARCH #1 (closed) SMP PREEMPT Wed Mar 22 15:02:04 CET 2017 i686 Kernel command line: BOOT_IMAGE=/boot/vmlinuz-linux root=UUID=225a86ef-06d5-49fa-9a6b-9308d5ddc384 rw quiet Build Date: 16 March 2017 02:50:50PM
http://wiki.x.org to make sure that you have the latest version. Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. (==) Log file: "/var/log/Xorg.0.log", Time: Sun Mar 26 20:40:10 2017 (EE) (EE) Backtrace: (EE) 0: /usr/lib/xorg-server/Xorg (OsLookupColor+0x132) [0x81e7582] (EE) 1: ? (?+0x132) [0xb77cfe21] (EE) 2: /usr/lib/xorg-server/Xorg (xf86PlatformMatchDriver+0x2f8) [0x80da968] (EE) 3: /usr/lib/xorg-server/Xorg (xf86BusProbe+0x13) [0x80b1b03] (EE) 4: /usr/lib/xorg-server/Xorg (InitOutput+0x7cf) [0x80c0d4f] (EE) 5: /usr/lib/xorg-server/Xorg (InitFonts+0x299) [0x807ce89] (EE) 6: /usr/lib/xorg-server/Xorg (miPolyFillRect+0x2c9) [0x80669a9] (EE) 7: /usr/lib/libc.so.6 (__libc_start_main+0xf6) [0xb7289366] (EE) 8: /usr/lib/xorg-server/Xorg (_start+0x21) [0x8066759] (EE) (EE) Segmentation fault at address 0x28 (EE) Fatal server error: (EE) Caught signal 11 (Segmentation fault). Server aborting (EE) (EE) Please consult the The X.Org Foundation support at http://wiki.x.org for help. (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information. (EE) (EE) Server terminated with error (1). Closing log file.
Current version of pixman: 0.34.0 Before reporting problems, checkAttachment 130470, "Full output of the startx command":
error.text