[regression] Unity/compiz crashes when locking screen

[Scaler]

[ Impact ]

A crash is occurring for many users of Trusty when the screen is locking.

[ Test Case ]

Lock the screen.

[ Regression Potential ]

None as this is removing a commit causing this regression.

The debdiff is found at https://bugs.launchpad.net/unity/+bug/1451613/+attachment/4409311/+files/unity.revert-3810.debdiff

-----------------------------------------------------------------------------

Original Description:

Since a recent update (around April 29th), sometimes (approximately once a day) when I lock my computer screen (CTRL+L or using system menu) the computer freeze for a while (2 to 30 seconds) before showing the login screen.
Then when I try to unlock the screen I need to enter my password twice (with no error message after the first try).
Once logged in, all applications are closed. Uptime is still running (since no reboot) and services too (with no interruption).

Looking at the apport.log file (see attached) it seems that when I try to lock the screen, compiz crashes.

I've attached the compiz crash file too (_usr_bin_compiz.1000.crash) but without the 100Mo data of base64 core dumb…

I'm using Ubuntu 14.04 AMD64.
Graphics drivers: nvidia-331.113 (tested)

[ivor (ivor-loncaric)]

It appens to me also, after every 2-3 locks...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Margarita Manterola (marga-9)]

Several other people at my company have seen this issue, using Unity for 14.04. Also using nvidia.

Compiz segfaults when the lock screen is supposed to get rendered and then the session is terminated, logging them out.

This started happening with the latest SRU, that ships:
  compiz 1:0.9.11.3+14.04.20150313-0ubuntu1
  unity 7.2.4+14.04.20150316-0ubuntu1

It was not happening before.

[Margarita Manterola (marga-9)]

The same problem has been reported as questions in AskUbuntu:

http://askubuntu.com/questions/618189/computer-logs-out-while-i-lock-screen
http://askubuntu.com/questions/611717/ubuntu-14-04-logs-me-out-when-i-try-to-lock-screen

I'll point these people here, but it seems like this is a pretty widespread problem.

[bolzano weierstrass (effectdoppler8)]

This bug affects me

[Margarita Manterola (marga-9)]

Downgrading unity and compiz to the previously available versions makes the problem go away. Unfortunately I don't know if just one of them would have been enough.

[Philipp Kern (pkern)]

Andrea, any idea about this?

[ekin (ekin)]

I have the same problem, dmesg shows the following:

[18317.562770] compiz[2269]: segfault at 3e8 ip 000003e8 sp bfac448c error 14 in compiz[8048000+3000]

[Andrea Azzarone (azzar1)]

Would be nice to have a backtrace.

[Joao Marinho (jubarim)]

I am also having the same problem here, it started to happen a lot after I did regular updates last friday.

I am using nvidia drivers 331.113

[Vitor Lopes-dos-Santos (vtlsantos)]

I also have the same problem.

[Ammar Ahmad (ammar-ahmad1993)]

This bug affects me. It just started happening.

[Andrea Azzarone (azzar1)]

Can anyone reproduce this on 15.04?

[Ammar Ahmad (ammar-ahmad1993)]

Sorry don't have 15.04 installed. However I did notice that if I disconnect my mouse and the lock my laptop, it locks perfectly.

[Scaler (balaton22)]

Same behavior tthan Ammar here:
- with mouse connected, crash happen every 2-3 locks,
- without mouse, no crash after 15 locks.

I'm using a Logitech Performance MX mouse.

I will try to give a backtrace when I figure how to produce it ^^"

[Ammar Ahmad (ammar-ahmad1993)]

Still unsure how to produce a backtrace...
Can anyone tell how to downgrade to previous versions?

[Andrea Azzarone (azzar1)]

Probably the crash is caused by the fix to bug #1401911. I'm looking into it. Do you have a multi-head setup?

[Ammar Ahmad (ammar-ahmad1993)]

Nope I don't have multiple monitors. I only have 1 screen that is the default laptop screen.

[Scaler (balaton22)]

I did some other tests with mouse and touchpad, when locking screen:
- if I use mouse click or click with button near touchpad → chrash
- if I use *tap* on touchpad or key shortcut CTRL+ALT+L (unlike what I said in my first report) → no crash

and I managed to produce a backtrace \o/ (that wasn't easy ^^").
See attached file.

[Andrea Azzarone (azzar1)]

"Then when I try to unlock the screen I need to enter my password twice (with no error message after the first try"

This seems strange to me. If compiz crashes you should not be able to unlcock the screen.

[Scaler (balaton22)]

I guess compiz is restarted somehow.
If that helps, I can sometimes very briefly see the nvidia logo before the first locked screen, like when I do a fresh boot.
But the system is not rebooted since services are still running…

[Lawrence Weetman (contack)]

I am also having this issue (approx daily). I'm running Ubuntu 14.04.2, with multiple monitors and an nvidia graphics card.

I'm afraid that I can't provide any logs/traces right now, but I can corroborate the thing about having to unlock twice. I can perhaps provide some more vague-but-useful information, though! I have a custom lockscreen background (unfortunately, I can't remember what method I used to set that). When this bug happens, the lock screen changes to the default Ubuntu background - the same as when I initially login after starting the PC. Once I've logged into this lockscreen, the screen goes black for a fraction of a second then it returns with the usual lockscreen with the custom background image. Once I've logged into that lockscreen, I am back at my desktop but with all apps closed.

[Lawrence Weetman (contack)]

I can reproduce this reliably with the method of moving the mouse when locking the PC (which I do with the keyboard shortcut).

[Lawrence Weetman (contack)]

I'm not sure if this is of any use or not, but I have re-generated the stacktrace from the relevant crash file using apport-retrace. It's attached.

[Andrea Azzarone (azzar1)]

The problem with the backtrace is that they are missing the debug symbols. Btw are you sure that light-lock is not installed?

[Andrea Azzarone (azzar1)]

Can you try to install the debug symbols? (
https://wiki.ubuntu.com/DebuggingProgramCrash)

2015-05-27 19:08 GMT+02:00 Andrea Azzarone <email address hidden>:

> The problem with the backtrace is that they are missing the debug
> symbols. Btw are you sure that light-lock is not installed?
>
> ** Changed in: unity
> Status: New => Confirmed
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1451613
>
> Title:
> Unity/compiz crashes when locking screen
>
> Status in Unity:
> Confirmed
> Status in unity package in Ubuntu:
> Confirmed
>
> Bug description:
> Since a recent update (around April 29th), sometimes (approximately once
> a day) when I lock my computer screen (CTRL+L or using system menu) the
> computer freeze for a while (2 to 30 seconds) before showing the login
> screen.
> Then when I try to unlock the screen I need to enter my password twice
> (with no error message after the first try).
> Once logged in, all applications are closed. Uptime is still running
> (since no reboot) and services too (with no interruption).
>
> Looking at the apport.log file (see attached) it seems that when I try
> to lock the screen, compiz crashes.
>
> I've attached the compiz crash file too (_usr_bin_compiz.1000.crash)
> but without the 100Mo data of base64 core dumb…
>
>
> I'm using Ubuntu 14.04 AMD64.
> Graphics drivers: nvidia-331.113 (tested)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/unity/+bug/1451613/+subscriptions
>

--
Andrea Azzarone
http://launchpad.net/~andyrock
http://wiki.ubuntu.com/AndreaAzzarone

[Scaler (balaton22)]

New backtrace with debug symbols (at least for the packages I could find a corresponding -dbg).

[Scaler (balaton22)]

and light-locker is not installed.

[Lawrence Weetman (contack)]

I can't install debug symbols right now, but wanted to mention that I don't have light-locker installed either.

[Christopher Townsend (townsend)]

Hi All,

None of us can reproduce the issue and without a stacktrace with symbols, it's very hard to tell exactly what may be causing the issue. That said, Andrea has a suspicion of what the problem is, so we need to volunteers to test it out.

I have created a PPA that is the latest Trusty version of Unity plus https://code.launchpad.net/~azzar1/unity/avoid-lambda-edgebarrier/+merge/260409. You can find the PPA at ppa:townsend/unity-test (https://launchpad.net/~townsend/+archive/ubuntu/unity-test). We would greatly appreciate if anyone affected by this please test the package there. If the crash still occurs, then I will back out that change as well as another change in the SRU that we suspect might have caused it and create a new package in the aforementioned PPA.

Thanks very much!

[Scaler (balaton22)]

Crash still occurs with package in ppa.

[Andrea Azzarone (azzar1)]

Did you restart unity?
On 29 May 2015 17:50, "Scaler" <email address hidden> wrote:

> Crash still occurs with package in ppa.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1451613
>
> Title:
> Unity/compiz crashes when locking screen
>
> Status in Unity:
> Confirmed
> Status in unity package in Ubuntu:
> Confirmed
>
> Bug description:
> Since a recent update (around April 29th), sometimes (approximately once
> a day) when I lock my computer screen (CTRL+L or using system menu) the
> computer freeze for a while (2 to 30 seconds) before showing the login
> screen.
> Then when I try to unlock the screen I need to enter my password twice
> (with no error message after the first try).
> Once logged in, all applications are closed. Uptime is still running
> (since no reboot) and services too (with no interruption).
>
> Looking at the apport.log file (see attached) it seems that when I try
> to lock the screen, compiz crashes.
>
> I've attached the compiz crash file too (_usr_bin_compiz.1000.crash)
> but without the 100Mo data of base64 core dumb…
>
>
> I'm using Ubuntu 14.04 AMD64.
> Graphics drivers: nvidia-331.113 (tested)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/unity/+bug/1451613/+subscriptions
>

[Scaler (balaton22)]

I've restarted my computer after updating the packages.

[Andrea Azzarone (azzar1)]

Ok, i'm trying to build a ppa with the correct dbg symbols for trusty.
Let's see if we can get a usable stacktrace.

2015-05-29 19:34 GMT+02:00 Scaler <email address hidden>:

> I've restarted my computer after updating the packages.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1451613
>
> Title:
> Unity/compiz crashes when locking screen
>
> Status in Unity:
> Confirmed
> Status in unity package in Ubuntu:
> Confirmed
>
> Bug description:
> Since a recent update (around April 29th), sometimes (approximately once
> a day) when I lock my computer screen (CTRL+L or using system menu) the
> computer freeze for a while (2 to 30 seconds) before showing the login
> screen.
> Then when I try to unlock the screen I need to enter my password twice
> (with no error message after the first try).
> Once logged in, all applications are closed. Uptime is still running
> (since no reboot) and services too (with no interruption).
>
> Looking at the apport.log file (see attached) it seems that when I try
> to lock the screen, compiz crashes.
>
> I've attached the compiz crash file too (_usr_bin_compiz.1000.crash)
> but without the 100Mo data of base64 core dumb…
>
>
> I'm using Ubuntu 14.04 AMD64.
> Graphics drivers: nvidia-331.113 (tested)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/unity/+bug/1451613/+subscriptions
>

--
Andrea Azzarone
http://launchpad.net/~andyrock
http://wiki.ubuntu.com/AndreaAzzarone

[Christopher Townsend (townsend)]

Hi,

While Andrea works on a way to get proper debugging symbols, I have uploaded a new package to the same PPA that reverts the potential fix and also reverts rev. 3810 which is where we suspect the problem is. Once the packages build and are published in the PPA, please try it out and see if the issue no longer occurs.

Thanks for testing this!

[Scaler (balaton22)]

I've update to the new build packages and after a reboot and ~40 locks/unlocks, no crash :)

[Ammar Ahmad (ammar-ahmad1993)]

The build works fine for me too... However I do have a question.. Now that I have installed this package, when the official build is published, would I have to do something to get the official version or will my system automatically do it for me?

[Andrea Azzarone (azzar1)]

Would be nice to install the debug symbols in this ppa, reproduce the crash and get a valid backtrace so we can properly fix the crash. The package is unity-dbg.

[Andrea Azzarone (azzar1)]

https://code.launchpad.net/~azzar1/+archive/ubuntu/unity-dbg-symbols

[Scaler (balaton22)]

I've updated packages (and installed unity-dbg) from ppa with debug symbols, then reboot. The backtrace is attached.

[Andrea Azzarone (azzar1)]

Seems like the debug symbols are not correct installed. At this point I
think it's safer to revert the fix that causes this crash.

2015-05-31 15:56 GMT+02:00 Scaler <email address hidden>:

> I've updated packages (and installed unity-dbg) from ppa with debug
> symbols, then reboot. The backtrace is attached.
>
> ** Attachment added: "gdb-compiz-v3.txt"
>
> https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1451613/+attachment/4407575/+files/gdb-compiz-v3.txt
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1451613
>
> Title:
> Unity/compiz crashes when locking screen
>
> Status in Unity:
> Confirmed
> Status in unity package in Ubuntu:
> Confirmed
>
> Bug description:
> Since a recent update (around April 29th), sometimes (approximately once
> a day) when I lock my computer screen (CTRL+L or using system menu) the
> computer freeze for a while (2 to 30 seconds) before showing the login
> screen.
> Then when I try to unlock the screen I need to enter my password twice
> (with no error message after the first try).
> Once logged in, all applications are closed. Uptime is still running
> (since no reboot) and services too (with no interruption).
>
> Looking at the apport.log file (see attached) it seems that when I try
> to lock the screen, compiz crashes.
>
> I've attached the compiz crash file too (_usr_bin_compiz.1000.crash)
> but without the 100Mo data of base64 core dumb…
>
>
> I'm using Ubuntu 14.04 AMD64.
> Graphics drivers: nvidia-331.113 (tested)
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/unity/+bug/1451613/+subscriptions
>

--
Andrea Azzarone
http://launchpad.net/~andyrock
http://wiki.ubuntu.com/AndreaAzzarone

[Stephane (stephanelhp)]

Hi,

I encountered the same problem since 2-3 weeks now.

My setup :

- Ubuntu 14.04 LTS

- Lenovo ThinkPad T420
   + an additional Lenovo Screen ThinkVision (20")
   + Logitech Anywhere MX mouse

I use the shortcut "Windows + L" (same as CTRL+ALT+L but less fingers are needed) to lock my laptop.
I cannot reproduce the issue, but it happens every day.

I have the same crash with Compiz (_usr_bin_compiz.1000.crash)

I tried to update Unity package, but the crash hasn't been fixed.

unity 7.2.5 + 14.04.20150 amd64
compiz 1:0.9.11.3 + 14.04. all

[Christopher Townsend (townsend)]

So far, this has only been reported on Trusty. It's still unclear to us why this is occurring only on Trusty. Given that we still don't have a proper fix in place for this on Trusty, we are just going to revert the offending commit and get an SRU out with only this reversion as soon as possible.

Thanks for everyone's patience and trying to help us debug this!

[Christopher Townsend (townsend)]

The debdiff for the SRU.

[Chris J Arges (arges)]

Hello Scaler, or anyone else affected,

Accepted unity into trusty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/unity/7.2.5+14.04.20150603-0ubuntu1 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!

[Christopher Townsend (townsend)]

It would be really great for someone who is affected by this to verify the Unity package in trusty-proposed does fix this issue, so we can get it into -updates soon.

Thanks!

[Ammar Ahmad (ammar-ahmad1993)]

I can help.. But I cant figure out how to update to it.. Can someone provide more instructions?

[Scaler (balaton22)]

Sorry I couldn't provide backtrace with debug symbols…

Regarding proposed packages:
To be sure, I went back to the old versions of packages unity, unity-services and libunity-core-6.0.9 (7.2.5+14.04.20150521.1-0ubuntu1), reboot, crashes are back.

Then I installed the proposed repository, updated the three packages to latest version: 7.2.5+14.04.20150603-0ubuntu1, reboot, no more crashes.

[Launchpad Janitor (janitor)]

This bug was fixed in the package unity - 7.2.5+14.04.20150603-0ubuntu1

---------------
unity (7.2.5+14.04.20150603-0ubuntu1) trusty; urgency=medium

  [ Chris Townsend ]
  * Revert rev. 3810 due to a crash being seen on Trusty when the
    lockscreen is activated. (LP: #1451613)

 -- CI Train Bot <email address hidden> Wed, 03 Jun 2015 15:22:38 +0000

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for unity 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 regressions.

[Dmitry Diskin (diskin)]

I'm seeing similar crash (compiz[788]: segfault at 0 ip (null) sp 00007fffea42e0f8 error 14 in compiz[400000+3000]) when I press "CapsLock" while session is locked. CapsLock is used to switch keyboard layouts. I'm on 16.04 with all recent updates installed.

[Igor Shuvalov (i-s-shuvalov)]

Same crash when I press "CapsLock" to change keyboard layout. At that moment anybody cat see all my staff on my computer and interact with it using keyboard. https://youtu.be/2KLL1vMM9Q8
If I change keyboard layout switch to other button, all ok.

[polonskiy (polonskiy-deactivatedaccount)]

I have the same problem as Dmitry Diskin (diskin) and Igor Shuvalov (i-s-shuvalov) have.

[Andrea Azzarone (azzar1)]

A fix for the crash has already been merged with trunk (see bug #1605012). We will SRU it in Xenial (16.04)