"signal Segmentation fault". Where this error is coming from?

Question

Hey! From time to time my Apache server logs this error

[Sat Nov 07 05:35:01 2009] [notice] child pid 2795 exit signal Segmentation fault (11)

What may be the reason behind the error?

Thanks!

Answer 1

Looks like you are running a cgi of some sort that is segfault under certain conditions. Check what cgi's you have and then test them. Most likely they will be a C or C++ based cgi, since it's a segfault, but no guarantee.

Answer 2

Perhaps it helps to reduce the value of MaxRequestsPerChild in your apache2.conf. In addition, it might be helpful to disable all Apache modules you have no need for.

Answer 3

A segfault basically is caused by an attempt to access memory in a non-authorized way. To determine where the problem occured, a core file can have been generated on your system. If necessary the system has to be configured to get those files, but this depends on your system ; see coreadm(1M) for instance.

Once you get the core file you can get the stack trace of the process that caused the fault with an utility such as pstack, and many more with a debugger.