When to install signal handlers

[Stefan Fritsch <sf...@sfritsch.de>]

Hi,

the Unix MPMs detach from the console in the pre-config hook but 
install their signal handlers (including the one for SIG_SEGV) only 
later, in the mpm hook. If a segfault happens in this time period, the 
segfault will not be visible on the console, won't be reported to the 
script starting httpd, and won't be logged in the error log. This can 
be somewhat confusing to users. I have seen this once with a mod_php 
bug.

Does anybody remember if there is a reason why the signal handlers are 
installed that late? Or can the code simply be moved to the pre-config 
hook, before detaching?

Cheers,
Stefan

Re: When to install signal handlers

[Greg Ames <am...@gmail.com>]

I don't remember any discussions on the subject or reasons why the timing is
as late as it is.  I assume signal handlers are cloned by the fork(). ++1 to
eliminating silent failures.

Greg

On Sun, Jul 24, 2011 at 2:25 PM, Stefan Fritsch <sf...@sfritsch.de> wrote:

> Hi,
>
> the Unix MPMs detach from the console in the pre-config hook but
> install their signal handlers (including the one for SIG_SEGV) only
> later, in the mpm hook. If a segfault happens in this time period, the
> segfault will not be visible on the console, won't be reported to the
> script starting httpd, and won't be logged in the error log. This can
> be somewhat confusing to users. I have seen this once with a mod_php
> bug.
>
> Does anybody remember if there is a reason why the signal handlers are
> installed that late? Or can the code simply be moved to the pre-config
> hook, before detaching?
>
> Cheers,
> Stefan
>