apache crashes with signal 11

Question

PHP

Please tell me how to find the leak.

There is a branded piece of hardware, it spins a couple of sites on Joomla, Gallery2, DokuWiki, phpMyAdmin, Munin
From time to time it crashes with the following entries in the log:

[notice] child pid 22048 exit signal Segmentation fault (11)

I tried to install apache2-mpm-itk ( I should have) - I get basically the same thing:
[error] child died with signal 11

In apache2.conf I set LogLevel debug, in php.ini I set error_reporting = E_ALL & ~E_DEPRECATED
but there is nothing interesting in the logs, sometimes php swears at Undefined variable and missing files and all.

It feels like the memory is flowing, but I can not understand who is to blame.

A little about the system:

# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=10.04
DISTRIB_CODENAME=lucid
DISTRIB_DESCRIPTION="Ubuntu 10.04.1 LTS"

# uname -a
Linux myserver 2.6.32-21-server #32-Ubuntu SMP Fri Apr 16 09:17:34 UTC 2010 x86_64 GNU/Linux

# apache2ctl - V
Server version: Apache/2.2.14 (Ubuntu)
Server built: Sep 28 2010 12:53:28
Server's Module Magic Number: 20051115:23
Server loaded: APR 1.3.8, APR-Util 1.3.9
Compiled using: APR 1.3 .8, APR-Util 1.3.9
Architecture: 64-bit
Server MPM: Prefork
threaded: no
forked: yes (variable process count)

# php5 -v
PHP 5.3.2-1ubuntu4.5 with Suhosin-Patch (cli) (built : Sep 17 2010 13:49:46)
Copyright © 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright © 1998-2010 Zend Technologies
with Suhosin v0.9.29, Copyright © 2007, by SektionEins GmbH

Additionally installed php-apc 3.1.3p1-2, tried updating to 3.1.4 and 3.1.5 - no difference no.

All installed software is from turnips, I did not collect anything myself.

UPD : the ambush turned out to be in a bunch of Joomla + APC. Demolished APC, set up nginx + apache2 + eAccelerator - a few days the flight is normal. Updating software versions has not yet been carried out for experimental purposes.

Answer 1

It may very well be that the problem is in some thread module, although I would still update Apache.
https://issues.apache.org/bugzilla/buglist.cgi?quicksearch=segmentation+fault

Answer 2

The problem is more in PHP than Apache. Are there any other extensions besides APC? Try to drive without php-apc. And update Apache and PHP to the latest versions (2.2.16 and 5.3.3 respectively).
Apache crashed regularly for me when I used eaccelerator; then crashed due to xdebug.

Answer 3

Try to catch the core file, load the gdb debugger and hook this file. You need to make a backtrace and try to understand at what stage of the work the error occurs.
Most likely, it will be seen in which function SIGSEGV failed. Debugging information is not necessarily required.