This will explain how to debug segmentation faults caused by
mod_php.    1. use     strace, truss, kdump/ktrace     on httpd
children and you will probably see the php filename causing the
issue    2. Set CoreDumpDirectory on one of the crashing systems
3. Make sure you have debugging symbols. On Redhat/CentOS you
will need to install -debuginfo RPM (for apache/httpd AND
php/mod_php)    4. Run     gdb httpd core.1234    5. Now run
6. and examine the     tips for php/gdb   7. print *opline
print opline->op2.u.constant.value.str.val     print
opline->op1.u.constant.value.str.val     In my case (and the one
below) op1 started with a null byte, so you needed to run:
print opline->op1.u.constant.value.str.val+1     And you will
get the php file name and, probably, the function which is
causing the issue.