trap divide error on Linux x86_64

Dear CUP,

I have an apache module that works fine for everyone but on one particular
user's system it faults with:

Mar 27 14:07:58 machine1 kernel: httpd2-prefork[23358] trap divide
error rip:2b838282c68f rsp:7fff282818d0 error:0

The module normally opens and writes to a log file fairly early on in the
module initialization routine but no log file is even created. SELinux
is disabled.

If the module is disabled, apache starts and runs ok.

The binaries are:

/usr/sbin/httpd2-prefork: ELF 64-bit LSB shared object, AMD x86-64,
version 1 (SYSV), for GNU/Linux 2.6.4, stripped

/usr/bin/php5: ELF 64-bit LSB executable, AMD x86-64, version 1
(SYSV), for GNU/Linux 2.6.4, dynamically linked (uses shared libs),
for GNU/Linux 2.6.4, stripped

/usr/lib64/php5/extensions/myextension.so: ELF 64-bit LSB shared object,
AMD x86-64, version 1 (SYSV), not stripped

The only difference I can see is that my dso is "not stripped".

Note that myextension.so is linked with a large .so that is a bundle of
numerous statically linked libraries which all together export only the
handful of symbols used by myextension.so.

I have tried recompiling all of the libraries and the extension but
still the "trap divide error" occurs.

Does anyone have any experience with this "trap divide error"?

Can you recommend a diagnostic?

Mike

Michael B Allen <miallen@ioplex.com> writes:

> I have an apache module that works fine for everyone but on one particular
> user's system it faults with:
>
>   Mar 27 14:07:58 machine1 kernel: httpd2-prefork[23358] trap divide
>   error rip:2b838282c68f rsp:7fff282818d0 error:0

The message comes from kernel, and simply means that user process
died with SIGFPE (i.e. you've likely divided something by zero).

> Can you recommend a diagnostic?

Have the user set 'ulimit -c unlimited', start apache from command
line, and it should dump core. Analyzing core should tell you
exactly where SIGFPE came from.

Cheers,
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