CoreDumpDirectory isn't working on ubuntu; getting segmentation fault with php

Question

I\'m trying to solve a segmentation fault. This message appears in my apache-error.log:

[notice] child pid 3979 exit signal Segmentation fault (11)

Answer 1

I finally was able to see Apache's core dump in Ubuntu:

1. edit /etc/default/apport

2. edit apache2.conf:

     CoreDumpDirectory /tmp/apache2-gdb-dump
   

3. make sure Apache can write to it:

   # chmod 777 /tmp/apache2-gdb-dump
   

4. remove core dump size limit:

   # ulimit -c unlimited
   

5. Optionally, change the name pattern of the core dumps:

   # echo 'coredump-%e.%p' > /proc/sys/kernel/core_pattern
   

To analyse the dump use gdb:

$ gdb apache2 /tmp/apache2-gdb-dump/coredump-x.x

To see stacktrace details, in gdb:

gdb> where

This I did, and I obtained the core-dump. However, my problem was not solved by looking at the coredump; it was apparently an issue in my php script.

More info: http://matrafox.info/apache-child-pid-exit-signal-segmentation-fault.html

Answer 2

Core dumps are disabled on Ubuntu by default

Try this:

ulimit -c unlimited

"ulimit -a" tells you what the current limit is (0 means disabled)

Answer 3

Do note that the subdirectory in /tmp will be removed after reboot, causing apache to not start due to configuration errors.

On a second note, the chowning is unnecessary. /tmp is chmodded 777 so anyone can read/write there.

@arod sudo ulimit -c does not work because -c is also an argument of sudo. You need to sudo -s, then ulimit -c