I am trying to solve the following error in my apache2 error.log file. I use Debian Jessie 8 up-to-date with apache 2.4.10 from repo.

[Tue May 31 16:35:21.951165 2016] [core:notice] [pid 6926:tid 140394522146688] >AH00052: child pid 6929 exit signal Segmentation fault (11)

This happen when a user connect to the website with an SSL client certificate. Everything works fine except we got this message every time.

To solve this, I try to generate a core dump from apache2. I followed the debian documentation :

mkdir /tmp/apache-coredumps/

chmod 755 /tmp/apache-coredumps/

chown www-data:www-data /tmp/apache-coredumps/

add this to my apache2.conf

CoreDumpDirectory /tmp/apache-coredumps

Execute the following command :

ulimit -c unlimited /etc/init.d/apache2 restart

Then I reproduce the error, but /tmp/apache-coredumps/ remain empty. User permission seems ok to me.

Any idea ?

  • are you running abrtd, as it will take over the dump. I know that systemd will use a private /tmp in /var/tmp for apache. I presume you are not using systemd, but perhaps something similar configures it. – meuh May 31 '16 at 15:48
  • You should check that actual httpd processes followed the ulimit setting and have both soft and hard Max core file size in their /proc/pid/limits set to unlimited. – user140866 May 31 '16 at 16:06
  • And I do not think that ulimit shell builtin takes cmdline and runs it with changed limits. – user140866 May 31 '16 at 16:06
  • There are also other requirements that process must meet to dump core files, for example, calling setuid and brothers or being traced by ptrace makes process undumpable in some cases. – user140866 May 31 '16 at 16:09
  • @meuh I'm using systemd, but /var/tmp/is empty. I am not using abrtd. – Hugo Jun 1 '16 at 7:50

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