apache core dump files
===

I am trying to read apache core dump files by gdb

and this is the short output not the complete output but i cannot post the whole output in here 

    # gdb /usr/local/apache/bin/httpd core.27476
    GNU gdb (GDB) CentOS (7.0.1-42.el5.centos)
    Copyright (C) 2009 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
    and "show warranty" for details.
    This GDB was configured as "i386-redhat-linux-gnu".
    For bug reporting instructions, please see:
    <http://www.gnu.org/software/gdb/bugs/>...
    Reading symbols from /usr/local/apache/bin/httpd...(no debugging symbols found)...done.
    [New Thread 27476]
    
    warning: .dynamic section for "/lib/libssl.so.6" is not at the expected address
    
    warning: difference appears to be caused by prelink, adjusting expectations
    
    warning: .dynamic section for "/lib/libcrypto.so.6" is not at the expected address
    
    warning: difference appears to be caused by prelink, adjusting expectations
    
    warning: .dynamic section for "/lib/librt.so.1" is not at the expected address
    
    warning: difference appears to be caused by prelink, adjusting expectations
    Core was generated by `/usr/local/apache/bin/httpd -k start -DSSL'.
    Program terminated with signal 11, Segmentation fault.
    #0  0xb3986ca8 in ?? ()

and i want to know what exactly cause this problem

thanks