Compiz crash on startup

[per-olav]

Thanks for any help. Ubuntu 12.10. After login Compiz crashes, and when I try to lunch it in terminal it doesn't work and the output is:

per-olav@asus12:~$ compiz
compiz (core) - Info: Loading plugin: core
compiz (core) - Info: Starting plugin: core
[...]
ERROR 2012-11-18 17:24:14 nux.gestures_subscription GesturesSubscription.cpp:299 Failed to activate Geis subscription.
Minnesegmentsfeil (core dumped)

[Impact]

In some computers, users are unable to get past the login screen. Compiz crashes right after it's started.

The fix should be backported as it's a simple null pointer check (i.e., low regression risk) and solves the serious problem described above. The crash happened because, in nux, when geis fails to activate a gestures subscription (which is an uncommon case, thus the low number of computers affected), nux destroys the related objects, which includes a pointer to a geis filter. In this situation that geis filter pointer is null and therefore geis_filter_delete() receives a null pointer and tries to access it, which causes a segmentation fault. The fix changes geis_filter_delete() so that it checks if the received pointer is null before trying to use it.

[Test Case]

A unit test has been included along with the fix.

For users with computers affected by this bug, testing the fix is really simple: after installing the package with the proposed fix, just try to log in and check if you get to the ubuntu desktop successfully.

[Regression Potential]

Only computers affected by this bug will get a different code path executed due to this fix, as they are the only ones that pass null pointers to geis_filter_delete() and, therefore, will now get a different behaviour out of this funticion (a no-op success instead of a segmentation fault).

[Daniel d'Andrada (dandrader)]

That nux.gestures_subscription error message by itself doesn't imply that there as a crash in geis.
A backtrace would be nice.

[per-olav (pobr1990)]

Thanks for the comments. How do I backtrace? When I logon Ubuntu 12.10 I only see the background, and nothing more. In a second the unity panel is shown, but then disappears.

[Daniel d'Andrada (dandrader)]

https://wiki.ubuntu.com/Unity/FilingBugs#Getting_a_stack_trace

[Daniel Nyström (speakman)]

Here's my backtrace. I could not find any debug symbols for neither geis nor compiz:

Starting program: /usr/bin/compiz
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[New Thread 0x7ffff3b5a700 (LWP 18643)]
[New Thread 0x7ffff0a64700 (LWP 18644)]
[New Thread 0x7fffebfff700 (LWP 18645)]
[New Thread 0x7fffd3397700 (LWP 18651)]

Program received signal SIGSEGV, Segmentation fault.
0x00007fffdc26b0e0 in ?? () from /usr/lib/x86_64-linux-gnu/libgeis.so.1

Thread 5 (Thread 0x7fffd3397700 (LWP 18651)):
#0 0x00007ffff70330fe in pthread_cond_timedwait@@GLIBC_2.3.2 ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#1 0x00007ffff5bca195 in g_cond_wait_until ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#2 0x00007ffff5b63761 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#3 0x00007ffff5bb0d6a in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#4 0x00007ffff5bb0645 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#5 0x00007ffff702ee9a in start_thread ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.
#6 0x00007ffff7337cbd in clone () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.
#7 0x0000000000000000 in ?? ()
No symbol table info available.

Thread 4 (Thread 0x7fffebfff700 (LWP 18645)):
#0 0x00007ffff732a8bd in read () from /lib/x86_64-linux-gnu/libc.so.6
No symbol table info available.
#1 0x00007ffff5bc915f in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#2 0x00007ffff5b8c914 in g_main_context_check ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#3 0x00007ffff5b8cd22 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#4 0x00007ffff5b8d1e2 in g_main_loop_run ()
   from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#5 0x00007ffff19b34a6 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
No symbol table info available.
#6 0x00007ffff5bb0645 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
No symbol table info available.
#7 0x00007ffff702ee9a in start_thread ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
No symbol table info available.

[per-olav (pobr1990)]

Thanks again! I've uploaded the file from the process.

[Daniel d'Andrada (dandrader)]

Thanks for the stack trace. that was very helpful.

Per-Olav,

Could you please attach the terminal output you get when you have the following enviroment variable set?
GEIS_DEBUG=3

[Daniel Nyström (speakman)]

Thank you for triaging, but I wouldn't put it on "medium" since my MacBook Air 2011 won't even start anymore. ;)

Just let me know if there's anything I can do - I'll stay alerted on all Launchpad mail!

[per-olav (pobr1990)]

If I understand this correctly, I just type "GEIS_DEBUG=3 geistest" in terminal? Used google to find the answer. It shows:

per-olav@asus12:~$ GEIS_DEBUG=3 geistest
GEIS(debug)-geis_register_backend:95 back end 0 registered as 'com.canonical.oif.backend.mock'
GEIS(debug)-geis_register_backend:95 back end 1 registered as 'com.canonical.oif.backend.dbus'
GEIS(debug)-geis_register_backend:95 back end 2 registered as 'com.canonical.oif.backend.grail'
GEIS(warning)-_set_valist:654 back end not specified, defaulting to DBus
GEIS(debug)-geis_backend_by_name:125 creating back end of class "com.canonical.oif.backend.dbus"
GEIS(debug)-_geis_wait_for_init:684 waiting for initialization to complete...
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 7 callback_info=0x1ac8560
GEIS(warning)-_locator_message_handler:120 server not found!
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1ac79f0
GEIS(debug)-_input_event_handler:261 input event available
GEIS(debug)-geis_backend_delete:162 destroying back end com.canonical.oif.backend.dbus
GEIS(debug)-geis_backend_by_name:125 creating back end of class "com.canonical.oif.backend.grail"
GEIS(debug)-geis_register_gesture_class:1219 registering class "Drag" id 0
GEIS(debug)-geis_register_gesture_class:1219 registering class "Pinch" id 1
GEIS(debug)-geis_register_gesture_class:1219 registering class "Rotate" id 2
GEIS(debug)-geis_register_gesture_class:1219 registering class "Tap" id 15
GEIS(debug)-geis_register_gesture_class:1219 registering class "Touch" id 32
GEIS(debug)-geis_register_region:1467 registering region
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1ac79f0
GEIS(debug)-_input_event_handler:261 input event available
GEIS(debug)-_default_output_event_callback:132 posting output event
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 9 callback_info=0x1ad9b70
GEIS(debug)-geis_register_device:1258 registering device "ETPS/2 Elantech Touchpad" id 40496
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1ac79f0
GEIS(debug)-_input_event_handler:261 input event available
GEIS(debug)-_default_output_event_callback:132 posting output event
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1ac79f0
GEIS(debug)-_input_event_handler:261 input event available
GEIS(debug)-_default_output_event_callback:132 posting output event
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1ac79f0
GEIS(debug)-_input_event_handler:261 input event available
GEIS(debug)-_default_output_event_callback:132 posting output event
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1ac79f0
GEIS(debug)-_input_event_handler:261 input event available
GEIS(debug)-_default_output_event_callback:132 posting output event
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1ac79f0
GEIS(debug)-_input_event_handler:261 input event available
GEIS(debug)-_default_output_event_callback:132 posting output event
GEIS(debug)-geis_backend_multiplexor_pump:415 activity 0x1 on fd 5 callback_info=0x1a...

[Daniel Nyström (speakman)]

Here's mine attached.

[Daniel d'Andrada (dandrader)]

@Per-Olav

Sorry, I meant the output you get when you run *compiz* (like you did in the description of this bug) and have that GEIS_DEBUG=3 env variable set.

[Daniel d'Andrada (dandrader)]

@speakman

Yes, that's it! Thanks!

[per-olav (pobr1990)]

Ahh, my bad, here is the output then:

per-olav@asus12:~$ GEIS_DEBUG=3 compiz
compiz (core) - Info: Loading plugin: core
compiz (core) - Info: Starting plugin: core
compiz (core) - Info: Loading plugin: ccp
compiz (core) - Info: Starting plugin: ccp
compizconfig - Info: Backend : gsettings
compizconfig - Info: Integration : true
compizconfig - Info: Profile : unity
compiz (core) - Info: Loading plugin: composite
compiz (core) - Info: Starting plugin: composite
compiz (core) - Info: Loading plugin: opengl
compiz (core) - Info: Unity is fully supported by your hardware.
compiz (core) - Info: Unity is fully supported by your hardware.
compiz (core) - Info: Starting plugin: opengl
compiz (core) - Info: Loading plugin: compiztoolbox
compiz (core) - Info: Starting plugin: compiztoolbox
compiz (core) - Info: Loading plugin: decor
compiz (core) - Info: Starting plugin: decor
compiz (core) - Info: Loading plugin: regex
compiz (core) - Info: Starting plugin: regex
compiz (core) - Info: Loading plugin: gnomecompat
compiz (core) - Info: Starting plugin: gnomecompat
compiz (core) - Info: Loading plugin: resize
compiz (core) - Info: Starting plugin: resize
compiz (core) - Info: Loading plugin: imgpng
compiz (core) - Info: Starting plugin: imgpng
compiz (core) - Info: Loading plugin: grid
compiz (core) - Info: Starting plugin: grid
compiz (core) - Info: Loading plugin: resizeinfo
compiz (core) - Info: Starting plugin: resizeinfo
compiz (core) - Info: Loading plugin: mousepoll
compiz (core) - Info: Starting plugin: mousepoll
compiz (core) - Info: Loading plugin: snap
compiz (core) - Info: Starting plugin: snap
compiz (core) - Info: Loading plugin: place
compiz (core) - Info: Starting plugin: place
compiz (core) - Info: Loading plugin: move
compiz (core) - Info: Starting plugin: move
compiz (core) - Info: Loading plugin: text
compiz (core) - Info: Starting plugin: text
compiz (core) - Info: Loading plugin: vpswitch
compiz (core) - Info: Starting plugin: vpswitch
compiz (core) - Info: Loading plugin: unitymtgrabhandles
GEIS(debug)-geis_register_backend:95 back end 0 registered as 'com.canonical.oif.backend.mock'
GEIS(debug)-geis_register_backend:95 back end 1 registered as 'com.canonical.oif.backend.dbus'
GEIS(debug)-geis_register_backend:95 back end 2 registered as 'com.canonical.oif.backend.grail'
compiz (core) - Info: Starting plugin: unitymtgrabhandles
compiz (core) - Info: Loading plugin: animation
compiz (core) - Info: Starting plugin: animation
compiz (core) - Info: Loading plugin: session
compiz (core) - Info: Starting plugin: session
I/O warning : failed to load external entity "/home/per-olav/.compiz/session/10ff0267cd306b4199135490646245402800000025900001"
compiz (core) - Info: Loading plugin: wall
compiz (core) - Info: Starting plugin: wall
compiz (core) - Info: Loading plugin: workspacenames
compiz (core) - Info: Starting plugin: workspacenames
compiz (core) - Info: Loading plugin: workarounds
compiz (core) - Info: Starting plugin: workarounds
compiz (core) - Info: Loading plugin: expo
compiz (core) - Info: Starting plugin: expo
compiz (expo) - Warn: failed to bind image to texture
compiz (core) - Info: Loading plugin: ezoom
compiz (core) ...

[Daniel Nyström (speakman)]

How can I easily test your patch? Are there an PPA archive available when it's been accepted? When I try rebuilding the geis package (debuild -us -uc) it complains about an "orig. tar.xz" has changed and halts. Ideas?

[Daniel Nyström (speakman)]

"For users with computers affected by this bug, testing the fix is really simple: after installing the package with the proposed fix, just try to log in and check if you get to the ubuntu desktop successfully."

Yes, trying to login I could really have guessed. But how to get the "package with the proposed fix"? Any PPA?

[Daniel d'Andrada (dandrader)]

@speakman

The package containing the fix should reach quantal-proposed repository soon. Then you'll be able to get it from there and verify the propsed fix.

[Daniel Nyström (speakman)]

Great. Make sure to notice those subscribing this bug. Thanks.

[per-olav (pobr1990)]

Thank you for fixing this bug :) also, thanks to speakman for help and contributions to the bug :) It's my first experience reporting a bug.

[Daniel d'Andrada (dandrader)]

FYI:
The fix is already in raring apt repositories but in order to reach precise it has to go through a process[1] that takes some time.

[1] - https://wiki.ubuntu.com/StableReleaseUpdates

[per-olav (pobr1990)]

What about quantal? Which package in proposed repository should I update?

[Daniel Nyström (speakman)]

I just tried to update, including quantal-proposed, but still no geis updates (latest changelog entry is 2.2.12-0buntu2).

[Daniel d'Andrada (dandrader)]

It's still waiting for a review/approval to get into quantal-proposed.

This is the queue of packages waiting to get there: https://launchpad.net/ubuntu/quantal/+queue?queue_state=1&direction=backwards&memo=30

[Brian Murray (brian-murray)]

This was not automatically marked as Fix Released for some reason, here is the changelog entry:

geis (2.2.15daily12.12.10-0ubuntu1) raring; urgency=low

  [ Daniel d'Andrada ]
  * Don't crash if a null filter is passed to geis_filter_delete() (LP: #1080386)

  [ Automatic PS uploader ]
  * Automatic snapshot from revision 300
 -- Automatic PS uploader <email address hidden> Mon, 10 Dec 2012 07:44:42 +0000

[Brian Murray (brian-murray)]

Hello Per-Olav, or anyone else affected,

Accepted geis into quantal-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/geis/2.2.12-0ubuntu3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Daniel Nyström (speakman)]

Sorry for this meta question, but since this bug took only one day to get fixed but over a month to reach the first official stage - what could we, the users, have done to quicken this process?

I havn't been able to run my MacBook Air 2012 with Ubuntu for over a month, and I guess I'm not the only one. Very frustrating. But I'm also eager to help, since open projects as Ubuntu rely on user contribution and collaboration.

What could have helped?

[per-olav (pobr1990)]

It works! Using version 2.2.12-0buntu3. Thanks a lot :-)

[Colin Watson (cjwatson)]

Daniel: unfortunately not a lot, we've been backlogged on SRU review which is hard for users to help with :-(

The best thing to do, albeit indirect, is to help with verifying SRUs that are already in -proposed. Reducing the volume of unverified updates means we have less to read routinely and speeds everything up.

[Launchpad Janitor (janitor)]

This bug was fixed in the package geis - 2.2.12-0ubuntu3

---------------
geis (2.2.12-0ubuntu3) quantal-proposed; urgency=low

  * Don't crash if a null filter is passed to geis_filter_delete() (LP: #1080386)
    - added 002-fix-lp1080386.patch
 -- Daniel d'Andrada <email address hidden> Mon, 10 Dec 2012 09:46:03 -0200

[Colin Watson (cjwatson)]

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.