[SOLVED] segfault-problems

Rosika · 05-07-2018, 08:22 AM

Hi altogether,

as of late I have the following "problem" or rather annoyance:

Up and until now it occurred three times that a programm crashed.

This phenomenon appeared only recently. Yet I cannot say precisely since when. No idea whether it has anything to do with the fact that I installed snap recently.
But I rather doubt it.

The following programmes/processes were affected:

1.) classicmenu-indicator
2.) chromium-browser
3.) evince.

What they all have in common is the mentioning of segfault:

Code:

13.04.18 16:20	rosika-Lenovo-H520e	kernel	[12749.510133] classicmenu-ind[2439]: segfault at ffffffffc38b95ff ip 00007faf06085470 sp 00007ffc4fdd6730 error 5 in libc-2.23.so[7faf06007000+1c0000]

25.04.18 15:26	rosika-Lenovo-H520e	kernel	[ 8512.292305] chromium-browse[5607]: segfault at fff7 ip 00007f3a54244512 sp 00007ffca20876d0 error 4 in libc-2.23.so[7f3a541c0000+1c0000]

07.05.18 13:49	rosika-Lenovo-H520e	kernel	[ 7441.074379] evince[10122]: segfault at 10037 ip 00007f96d7b0d2cb sp 00007ffdac689bf0 error 4 in libcairo.so.2[7f96d7af8000+10e000]

As you can see there are two times libc-2.23.so and one time libcairo.so.2 involved.

I really did nothing to trigger those crashes. They happened all by themselves. Yet I have to say that - as far as I can remember - I had the mouse-pointer located over the respective programmes. But I didn´t perform a click.

Plus: chromium-browser and evince were running within firejail (sandbox) at the time.

Those are all the facts I can provide you with. Has anyone any idea what could be going on here?

Thanks a lot in advance.

Greetings.
Rosika

P.S.:
system: Linux/Lubuntu 16.0404 LTs, 64 bit
kernel: 4.4.0-122-generic #146

rtmistler · 05-07-2018, 10:21 AM

These three occurrences have occurred each on different days, but all within the last month approximately:
13.04.18 = 4/13/2018
24.04.18 = 4/25/2018
07.05.18 = 5/7/2018

Given that the timestamps for each have decreased, then it appears you have restarted after each:
First occurrence [12749.xxxx]
Second occurrence [ 8512.xxxx]
Third occurrence [ 7441.xxxx]

Those I believe are timestamps from the start of the system in seconds.microseconds. Nothing dramatic, it just appears that you have restarted between each event occurrence, and also there have been several days between each of them.

I'm not sure they are related exactly, it may be that the libc-2.23 ones have a common issue. The error codes are different and the locations in the library binary are shown as different for each of those.

The only way to truly debug these are to build those libraries from source and enable debug flags. Run so as to obtain a core file dump and then analyze it, or run under a debugger and analyze it when you hit a fault occurrence. This is not an everyday occurrence and a direction that people would only take if they have good experience rebuilding the libraries and performing debugging on them.

Perhaps you can check the Ubuntu site for the versions of these libraries which are tested with 16.04 and verify that you're not using something which isn't intended for that version.

Another option is to consider upgrading the Ubuntu version.

How critical are these segmentation faults? Did you never notice them and only see them upon checking your system log? Or did you experience problems and then go look to see if there were any logs?

hazel · 05-07-2018, 10:53 AM

Segfaults in standard libraries are quite unusual. In your place I would try updating my whole system via apt-get and see if that makes the problem go away.

Rosika · 05-07-2018, 10:55 AM

Hi rtmistler,

tnx a lot for your answer.

Quote:

How critical are these segmentation faults? Did you never notice them and only see them upon checking your system log? Or did you experience problems and then go look to see if there were any logs?

Well, I noticed that e.g. evince all of a sudden closed its window and thus the respective process seems to have been killed somehow. Plus: I moved my mouse-pointer over the application. So I immediately noticed that evince closed down.
It was pretty much the same with the other applications.

Quote:

Perhaps you can check the Ubuntu site for the versions of these libraries which are tested with 16.04 and verify that you're not using something which isn't intended for that version.

Good suggestion. Do you have any specific address?
In the meanwhile I´m trying to find out more about it.

Greetings
Rosika

Rosika · 05-07-2018, 10:59 AM

Hi hazel,

Good suggestion.
But I think I´ve already done what you have in mind.
Here´s what I do on a regular basis:

Code:

sudo apt-get update
sudo apt-get upgrade
[and sometimes] sudo apt-get dist-upgrade

So it would seem that my system already is up-to-date (hopefully).

Greetings
Rosika

hazel · 05-07-2018, 11:23 AM

It's also worth checking /etc/apt/sources.list and /etc/apt/sources.list.d. These are where apt looks for repositories. Make sure that they are all for the same version of Ubuntu and that there are no non-Ubuntu ones (for example belonging to Debian or Mint).

rtmistler · 05-07-2018, 11:23 AM

I don't have a specific place to check. Recommend if you wish, to try Ubuntu's forums and/or bug reports.

There is a new Ubuntu LTS, Release 18. Seems to have just come out in the last few weeks.

Rosika · 05-07-2018, 11:37 AM

@ hazel:
tnx for the tip. I´ll do that right away.

@ rtmistler:

O.K. I´ll look around a bit more.
And yeah, I know that 18.04 LTS came out only recently.
The thing is: Xenial Xerus is supported until April next year. And I really want to keep it as long as possible.
I´ve never done a system-upgrade before and who knows how that´s going......

Anyway, thanks a lot to all of you.

Greetings
Rosika

Rosika · 05-07-2018, 11:49 AM

@ hazel:

I´ve done what you suggested.
Here´s the combined output of /etc/apt/sources.list and /etc/apt/sources.list.d:

Code:

# deb cdrom:[Lubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main multiverse restricted universe

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://de.archive.ubuntu.com/ubuntu/ xenial main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://de.archive.ubuntu.com/ubuntu/ xenial-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://de.archive.ubuntu.com/ubuntu/ xenial universe
# deb-src http://de.archive.ubuntu.com/ubuntu/ xenial universe
deb http://de.archive.ubuntu.com/ubuntu/ xenial-updates universe
# deb-src http://de.archive.ubuntu.com/ubuntu/ xenial-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://de.archive.ubuntu.com/ubuntu/ xenial multiverse
# deb-src http://de.archive.ubuntu.com/ubuntu/ xenial multiverse
deb http://de.archive.ubuntu.com/ubuntu/ xenial-updates multiverse
# deb-src http://de.archive.ubuntu.com/ubuntu/ xenial-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://de.archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner

deb http://de.archive.ubuntu.com/ubuntu/ xenial-security main restricted
# deb-src http://security.ubuntu.com/ubuntu xenial-security main restricted
deb http://de.archive.ubuntu.com/ubuntu/ xenial-security universe
# deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb http://de.archive.ubuntu.com/ubuntu/ xenial-security multiverse
# deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
# deb-src http://de.archive.ubuntu.com/ubuntu xenial main universe
# deb-src http://de.archive.ubuntu.com/ubuntu xenial main universe

deb http://codezen.org/debian xenial main
deb-src http://codezen.org/debian xenial main
deb http://download.virtualbox.org/virtualbox/debian xenial contrib
# deb-src http://download.virtualbox.org/virtualbox/debian xenial contrib
insgesamt 84
-rw-r--r-- 1 root root 144 Jul  6  2017 arkose-devel-ubuntu-stable-xenial.list
-rw-r--r-- 1 root root 144 Jul  6  2017 arkose-devel-ubuntu-stable-xenial.list.save
-rw-r--r-- 1 root root 134 Jul  6  2017 atareao-ubuntu-atareao-xenial.list
-rw-r--r-- 1 root root 134 Jul  6  2017 atareao-ubuntu-atareao-xenial.list.save
-rw-r--r-- 1 root root 158 Jul  6  2017 format-junkie-team-ubuntu-release-xenial.list
-rw-r--r-- 1 root root 158 Jul  6  2017 format-junkie-team-ubuntu-release-xenial.list.save
-rw-r--r-- 1 root root 172 Jul  6  2017 maarten-baert-ubuntu-simplescreenrecorder-xenial.list
-rw-r--r-- 1 root root 172 Jul  6  2017 maarten-baert-ubuntu-simplescreenrecorder-xenial.list.save
-rw-r--r-- 1 root root 189 Jul  6  2017 midori-ubuntu-ppa-xenial.list
-rw-r--r-- 1 root root 189 Jul  6  2017 midori-ubuntu-ppa-xenial.list.save
-rw-r--r-- 1 root root 134 Jul  6  2017 nemh-ubuntu-systemback-xenial.list
-rw-r--r-- 1 root root   0 Aug  7  2016 nvbn-rm-ubuntu-ppa-xenial.list
-rw-r--r-- 1 root root   0 Aug  7  2016 nvbn-rm-ubuntu-ppa-xenial.list.save
-rw-r--r-- 1 root root 132 Jul  6  2017 teejee2008-ubuntu-ppa-xenial.list
-rw-r--r-- 1 root root 132 Jul  6  2017 teejee2008-ubuntu-ppa-xenial.list.save
-rw-r--r-- 1 root root 150 Jul  6  2017 ubuntu-x-swat-ubuntu-x-updates-xenial.list
-rw-r--r-- 1 root root 150 Jul  6  2017 ubuntu-x-swat-ubuntu-x-updates-xenial.list.save
-rw-r--r-- 1 root root   0 Aug 10  2016 vincent-c-ubuntu-nevernote-xenial.list
-rw-r--r-- 1 root root   0 Aug 10  2016 vincent-c-ubuntu-nevernote-xenial.list.save
-rw-r--r-- 1 root root   0 Nov  8  2016 wallch-ubuntu-wallch-4_0-xenial.list
-rw-r--r-- 1 root root   0 Nov  8  2016 wallch-ubuntu-wallch-4_0-xenial.list.save
-rw-r--r-- 1 root root   0 Nov  8  2016 wallch-ubuntu-wallch-daily-xenial.list
-rw-r--r-- 1 root root   0 Nov  8  2016 wallch-ubuntu-wallch-daily-xenial.list.save
-rw-r--r-- 1 root root 134 Jul  6  2017 webkit-team-ubuntu-ppa-xenial.list
-rw-r--r-- 1 root root 134 Jul  6  2017 webkit-team-ubuntu-ppa-xenial.list.save
-rw-r--r-- 1 root root 144 Jul  6  2017 wireshark-dev-ubuntu-stable-xenial.list
-rw-r--r-- 1 root root 144 Jul  6  2017 wireshark-dev-ubuntu-stable-xenial.list.save
-rw-r--r-- 1 root root 132 Jul  6  2017 zerkalica-ubuntu-main-xenial.list
-rw-r--r-- 1 root root 132 Jul  6  2017 zerkalica-ubuntu-main-xenial.list.save

It seems to me that everything is as it should be...

Cheers
Rosika

ondoho · 05-07-2018, 01:06 PM

Quote:

Originally Posted by Rosika

Code:

deb http://codezen.org/debian xenial main
deb-src http://codezen.org/debian xenial main
deb http://download.virtualbox.org/virtualbox/debian xenial contrib
# deb-src http://download.virtualbox.org/virtualbox/debian xenial contrib

fishy.
"debian xenial" does NOT exist.
why are those in there?
how and why did you add them?

ideally, you'd need to research if they pulled in incompatible versions of libc and libcairo, and maybe other stuff.

hazel · 05-07-2018, 01:55 PM

What strikes me as odd is the huge collection of private repos. Yes, they're all xenial so they should be compatible, but why are they needed? Ubuntu has some of the biggest official repos of any distro.

The more repos you have as sources, the more duplicated packages you are likely to get. And the more likely it becomes that some program will link to the wrong version of a library,

Rosika · 05-08-2018, 07:29 AM

Hi again and thanks,

@ ondoho:

Quote:

"debian xenial" does NOT exist.

O.K., that might be a hint. Odd though, as I installed e.g. canto feed-reader as per instructions on
https://wiki.ubuntuusers.de/Canto/.
They say there that canto needs to be installed from a foreign source in order to get the latest version.
In order to authenticate the foreign source the signing key needs to be downloaded and added to package management. That´s probably what I did. I can´t remember precisely because that was quite a long time ago.....

Anyway:

Quote:

deb http://codezen.org/debian xenial main

is referenced by ubuntuusers.de on that page. So theoretically debian xenial should exist.

As far as virtualbox is concerned I think I performed

Code:

sudo add-apt-repository 'deb http://download.virtualbox.org/virtualbox/debian xenial contrib'

at the time of installation. Again I was just following instructions given by ubuntuusers.de.

@ hazel:

Quote:

What strikes me as odd is the huge collection of private repos. Yes, they're all xenial so they should be compatible, but why are they needed?

Good question.
The only thing I can safely say is that they got there in the course of installing programs, probably because
they (or at least some of them) weren´t available via the official repos as far as the latest versions are concerned.
It´s safe to say that I didn´t decide to do anything on my own. I was just following instructions.
It would be a bit of a shame if that turned against me now.

Greetings
Rosika

pan64 · 05-08-2018, 07:58 AM

Quote:

Originally Posted by Rosika

It´s safe to say that I didn´t decide to do anything on my own. I was just following instructions.
It would be a bit of a shame if that turned against me now.

It is not really important. (I mean if it was your own decision or you just followed some instructions).
The result is terrible, and hard to recover.
Most probably you need to reinstall the original system libraries. I don't know exactly your OS, but I would check if libc is ok.
And also try to install the official evince, chromium.

Rosika · 05-08-2018, 08:12 AM

Hi pan64,

Quote:

but I would check if libc is ok.

O.K. I´d be glad to do that. But how exactly do I go about it? I´d need to check libc-2.23.so and libcairo.so.2 .
My OS is Lubuntu 16.04.4 LTS, 64 bit, kernel: 4.4.0-122-generic #146.

Greetings.
Rosika

pan64 · 05-08-2018, 08:20 AM

for example libc-2.23.so is part of the package libc6 https://packages.ubuntu.com/xenial/libc6