Segmentation fault with all mythtv apps [SOLVED].

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

Hello everyone,

I've been having some difficulties lately with my mythtv setup. I had everything working well, and then, probably after some update of some sort, I can't get any of the mythtv applications to work. Whether I execute mythfilldatabase, mythbackend, mythfrontend... They all throw a segmentation fault error a few seconds after launch.

I've executed all these commands with strace and found nothing. My logs also show nothing.

Anyone know what could be wrong with my setup? What library or depency is causing this?

Any insight would be great.

Voltago · Posted: Wed Aug 15, 2007 12:48 pm Post subject:

http://forums.gentoo.org/viewtopic-t-575655-highlight-.html

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

Come to think of it, I think everything broke when I updated expat.

Gonna try what you sent me.

Thanks

timbo · Posted: Thu Aug 16, 2007 3:20 am Post subject:

goldfingerz

I had this happen when I upgraded to libXrandr-1.2.1 from 1.1.1. It's now fixed with the latest svn version of MythTV see here.

Regards
Tim

_________________
Linux User: 303160

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

I've tried everything you guys suggested and I'm still getting the segmentation faults. Nothing with mythtv seems to work. I really don't get it.

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

I also don't understand why strace isn't revealing any insights to the problem. Anything else I can use to debug this problem?

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

I just recompiled mythtv with the debug flag. Afterwards I ran this command:

gdb mythbackend -x gdbcommands

and I got this output:

(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()

What does this mean?

RoundsToZero · Guru Joined: 17 Nov 2003 Posts: 478 Location: New York, NY

It's probably is because your binaries are stripped (this is default on Gentoo to reduce size). Add "nostrip" to your FEATURES in make.conf. -g in your C(XX)FLAGS would be good too.

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

I just recompiled mythtv with the added options in my make.conf file and now I only get this output when I run mythbackend with gdb:

GNU gdb 6.6
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
Using host libthread_db library "/lib/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) quit
The program is running. Exit anyway? (y or n) y

Rob1n · Posted: Fri Aug 17, 2007 1:11 pm Post subject:

At that point try doing (from gdb), "thread apply all bt full"

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

Just did that, and got this:

(gdb) thread apply all bt full
(gdb) run
Starting program: /usr/bin/mythbackend -l myth.log -v record,channel,siparser

Program exited with code 0362.

I'm googling right now to find out what code 0362 stands for. Let me know if you know.

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

BTW, I also did this afterwards:

(gdb) bt
No stack.
(gdb)

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

OMG, it's working. I don't get it.

While I was re-emerging xorg-server-1.3.0 to xorg-server-1.2.0-r3, the segfaults stop happening. I don't get it. I don't know what changed.

Gonna try and see what changed since last night and let you guys know.

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

I figured out the problem.

It had to do with the opengl driver I was using. By using the eselect tool I was able to set the driver to either nvidia or xorg-x11. I noticed that when it opengl was set to nvidia mythtv apps would segfault. When it was set to xorg-x11, the problem would go away.

To list the drivers I did this:

eselect opengl list

To set to a particular driver I did this:

#To set to the first driver
eselect opengl set 1
#To set to the second driver
eselect opengl set 2

goldfingerz · n00b Joined: 07 Jul 2004 Posts: 30

Thanks for the help everyone. Gotta love Gentoo and its forums.