[mp2] Overwrites and truncates Apache process name

[Jonathan Wiltshire <jm...@tiger-computing.co.uk>]

Hi,

Current versions of mod_perl2 include the following line in
src/modules/perl/modperl_config.c:

187     /* make sure httpd's argv[0] is the first argument so $0 is
188      * correctly connected to the real thing */
189     modperl_config_srv_argv_push(s->process->argv[0]);

Without mod_perl2, a running Apache process has a name "apache2" in
/proc/$$/status (this is on a Debian machine, so on other distributions
that name might differ).

With mod_perl2 loaded, the name is "/usr/sbin/apach" - note the
additional path information that causes the name to be truncated.

This causes us (Tiger Computing) some difficulties in our monitoring of
Apache with mod_perl loaded, and users elsewhere have reported similar
experiences [1][2]

A bug was reported to Fedora[3] in March 2012, and a patch applied[4],
but it's not clear whether this was ever reported upstream. The patch
uses s->process->short_name instead.

Please could you comment on
a) the problem, and whether it's a genuine bug
b) the patch that Fedora applied

1: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=754702
2:
https://bugs.launchpad.net/ubuntu/+source/libapache2-mod-perl2/+bug/1008385
3: https://bugzilla.redhat.com/show_bug.cgi?id=782369
4: https://bugzilla.redhat.com/attachment.cgi?id=567625&action=diff

Thanks,

-- 
Jonathan Wiltshire
Tiger Computing Ltd
"Linux for Business"

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