[multimonitor] XMir crashes when changing layout/resolution

[Daniel van Vugt]

XMir crashed when changing layout/resolution in Control Center:

[ 151.842] (EE) Backtrace:
[ 151.843] (EE) 0: /usr/bin/X (xorg_backtrace+0x3d) [0x7fee35c220dd]
[ 151.843] (EE) 1: /usr/bin/X (0x7fee35a80000+0x1a5e49) [0x7fee35c25e49]
[ 151.843] (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7fee34b80000+0xfbb0) [0x7fee34b8fbb0]
[ 151.843] (EE) 3: /usr/bin/X (0x7fee35a80000+0x12d515) [0x7fee35bad515]
[ 151.843] (EE) 4: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7fee307a9000+0xc502f) [0x7fee3086e02f]
[ 151.843] (EE) 5: /usr/lib/xorg/modules/drivers/intel_drv.so (0x7fee307a9000+0xc5ef8) [0x7fee3086eef8]
[ 151.843] (EE) 6: /usr/bin/X (DRI2SwapBuffers+0x2ab) [0x7fee35bf56db]
[ 151.843] (EE) 7: /usr/bin/X (0x7fee35a80000+0x176da3) [0x7fee35bf6da3]
[ 151.843] (EE) 8: /usr/bin/X (0x7fee35a80000+0x54fce) [0x7fee35ad4fce]
[ 151.843] (EE) 9: /usr/bin/X (0x7fee35a80000+0x4452a) [0x7fee35ac452a]
[ 151.843] (EE) 10: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf5) [0x7fee337bcde5]
[ 151.843] (EE) 11: /usr/bin/X (0x7fee35a80000+0x4486f) [0x7fee35ac486f]
[ 151.843] (EE)
[ 151.843] (EE) Segmentation fault at address 0x0
[ 151.843] (EE)
Fatal server error:
[ 151.843] (EE) Caught signal 11 (Segmentation fault). Server aborting

[Daniel van Vugt (vanvugt)]

Using qa-testing2 with:
ii xserver-common 2:1.14.2.901-2ubuntu3+xmirMM10 all common files used by various X servers
ii xserver-xephyr 2:1.14.2.901-2ubuntu3+xmirMM10 amd64 nested X server
ii xserver-xorg-core 2:1.14.2.901-2ubuntu3+xmirMM10 amd64 Xorg X server - core server
ii xserver-xorg-input-vmmouse 1:12.9.0-0ubuntu4 amd64 X.Org X server -- VMMouse input driver to use with VMWare
ii xserver-xorg-video-intel 2:2.21.14-4ubuntu2+xmirMM5 amd64 X.Org X server -- Intel i8xx, i9xx display driver
ii xserver-xorg-video-nouveau 1:1.0.8-0ubuntu3+xmirMM2 amd64 X.Org X server -- Nouveau display driver
ii xserver-xorg-xmir 2:1.14.2.901-2ubuntu3+xmirMM10 amd64 Xorg - the X.Org X server (module for running nested in Mir)

[Daniel van Vugt (vanvugt)]

Tried changing just the layout, not the resolution. It still crashed, slightly differently

[ 46.459] (EE) Backtrace:
[ 46.460] (EE) 0: /usr/bin/X (xorg_backtrace+0x3d) [0x7fabe8ac90dd]
[ 46.460] (EE) 1: /usr/bin/X (0x7fabe8927000+0x1a5e49) [0x7fabe8acce49]
[ 46.460] (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7fabe7a27000+0xfbb0) [0x7fabe7a36bb0]
[ 46.460] (EE) 3: /usr/bin/X (0x7fabe8927000+0x12d500) [0x7fabe8a54500]
[ 46.460] (EE) 4: /usr/bin/X (0x7fabe8927000+0x12d798) [0x7fabe8a54798]
[ 46.460] (EE) 5: /usr/bin/X (0x7fabe8927000+0x130e9a) [0x7fabe8a57e9a]
[ 46.460] (EE) 6: /usr/bin/X (0x7fabe8927000+0x183803) [0x7fabe8aaa803]
[ 46.460] (EE) 7: /usr/bin/X (0x7fabe8927000+0x1926af) [0x7fabe8ab96af]
[ 46.460] (EE) 8: /usr/bin/X (0x7fabe8927000+0x19327b) [0x7fabe8aba27b]
[ 46.460] (EE) 9: /usr/bin/X (mieqProcessInputEvents+0x12c) [0x7fabe8aab54c]
[ 46.460] (EE) 10: /usr/bin/X (ProcessInputEvents+0x9) [0x7fabe89b8c19]
[ 46.460] (EE) 11: /usr/bin/X (0x7fabe8927000+0x54dd6) [0x7fabe897bdd6]
[ 46.460] (EE) 12: /usr/bin/X (0x7fabe8927000+0x4452a) [0x7fabe896b52a]
[ 46.460] (EE) 13: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf5) [0x7fabe6663de5]
[ 46.460] (EE) 14: /usr/bin/X (0x7fabe8927000+0x4486f) [0x7fabe896b86f]
[ 46.460] (EE)
[ 46.460] (EE) Segmentation fault at address 0x0
[ 46.460] (EE)
Fatal server error:
[ 46.460] (EE) Caught signal 11 (Segmentation fault). Server aborting
[ 46.460] (EE)

[Chris Halse Rogers (raof)]

Curiously, manually setting things with xrandr works just fine for me.

[Daniel van Vugt (vanvugt)]

Confirmed that setting the layout on the command line mostly works:
    xrandr --output FOO --left-of BAR
etc

The crash only seems to happen with gnome-control-center.

[Daniel van Vugt (vanvugt)]

Actually, xrandr's not totally stable either. Most of the time if I try to --mode using xrandr, X will crash.

[Daniel van Vugt (vanvugt)]

I've checked that unity-system-compositor remains stable across X instances/crashes, so it looks like the Mir project is not related, for now.

[Daniel van Vugt (vanvugt)]

Seems to be fixed in ppa:mir-team/qa-testing2 now.