When running apache as usual, ie. started as root and 
with configuration directives User apache and Group 
apache, the parent apache process continues to run as 
root, as per the apache manual.

When invoking any of the get_myuid, get_mygid etc. 
functions however, they always return 0 ie. the root 
user, which is what the parent process runs under. If 
you try to perform any file operation however, it is 
clear that PHP is really NOT root, since it fails 
unless the file is owned or accessible by the apache 
user or group.

This has a serious impact on safe_mode, as php then 
checks every file you work with if it's owned by root. 
Finding that it isn't, it aborts the operation. If it 
IS owned by root, then apache goes ahead and fails with 
permission denied, since PHP is still not root and 
never will be.

I made a PHP script which first displayed the 
getmyuid() and getmygid() values, and then (using back 
pings) ran a program which printed out its own uid, 
gid, euid and egid. The result:

Running as 0/0 (user root).
Results from iddump:

          User id : 81
          Group id: 81
Effective user id : 81
Effective group id: 81

uid/gid 81 would be the apache user/group. I guess the 
bug is somewhat caused by the parent process of apache 
running as root:root, but then again, as is also 
evident when performing file operations, PHP really is 
NOT running as the user/group it thinks.

My apache info:
Server Version: Apache/1.3.27 (Unix)  (Gentoo/Linux) 
mod_ssl/2.8.14 OpenSSL/0.9.6i PHP/4.3.1

My PHP configuration is as follows:
./configure' '--prefix=/usr' '--with-bz2' '--enable-
ftp' '--enable-force-cgi-redirect' '--enable-discard-
path' '--enable-mime-magic' '--enable-wddx' '--enable-
dbase' '--with-zlib=yes' '--with-iconv' '--enable-
bcmath' '--enable-sysvsem' '--enable-exif' '--enable-
sysvshm' '--enable-sockets' '--enable-calendar' '--
enable-trans-sid' '--enable-safe-mode' '--enable-
versioning' '--enable-track-vars' '--enable-inline-
optimization' '--with-config-file-path=/etc/php4' '--
host=i686-pc-linux-gnu' '--without-readline' '--with-
pam' '--with-gettext' '--with-openssl' '--with-gdbm=/
usr' '--with-db3=/usr' '--with-mysql=/usr' '--with-
jpeg-dir=/usr' '--with-pspell' '--with-png-dir=/usr' 
'--with-zlib' '--with-zlib-dir=/usr/lib' '--with-exec-
dir=/usr/bin' '--with-apxs=/usr/sbin/apxs' '--with-xml' 
'--with-dom' '--with-mcrypt' '--with-mhash' '--disable 
posix-threads'