centos 5.0
selinux 为开启状态
apache 2.2.8
php 5.0

安装完成之后，apache无法加载php模块。错误如下：
httpd: Syntax error on line 232 of /usr/local/apache2/conf/httpd.conf: API module structure 'php5_module' in file /usr/local/apache2/modules/libphp5.so is garbled - expected signature 41503232 but saw 41503230 - perhaps this is not an Apache module DSO, or was compiled for a different Apache version?

相信提示大伙都能看懂。网上有解决办法就是关闭selinux 下面讲另二种方法
一：按提示操作：（大体意思是将libphp5.so加入selinux系统内）

#tail /var/log/messages
May 23 10:08:15 nagios setroubleshoot:      SELinux is preventing /usr/local/apache2/bin/httpd from loading /usr/local/apache2/modules/libphp5.so which requires text relocation.      For complete SELinux messages. run sealert -l e693621e-145b-4431-bdcb-68b3883f1ac8
 
 
# sealert -l e693621e-145b-4431-bdcb-68b3883f1ac8
Summary
    SELinux is preventing /usr/local/apache2/bin/httpd from loading
    /usr/local/apache2/modules/libphp5.so which requires text relocation.

Detailed Description
    The /usr/local/apache2/bin/httpd application attempted to load
    /usr/local/apache2/modules/libphp5.so which requires text relocation.  This
    is a potential security problem. Most libraries do not need this permission.
    Libraries are sometimes coded incorrectly and request this permission.  The
    [url]http://people.redhat.com/drepper/selinux-mem.html[/url] web page explains how to
    remove this requirement.  You can configure SELinux temporarily to allow
    /usr/local/apache2/modules/libphp5.so to use relocation as a workaround,
    until the library is fixed. Please file a
    [url]http://bugzilla.redhat.com/bugzilla/enter_bug.cgi[/url] against this package.

Allowing Access
    If you trust /usr/local/apache2/modules/libphp5.so to run correctly, you can
    change the file context to textrel_shlib_t. "chcon -t textrel_shlib_t
    /usr/local/apache2/modules/libphp5.so"

    The following command will allow this access:
    chcon -t textrel_shlib_t /usr/local/apache2/modules/libphp5.so

Additional Information        

Source Context                user_u:system_r:unconfined_t
Target Context                system_u:object_r:lib_t
Target Objects                /usr/local/apache2/modules/libphp5.so [ file ]
Affected RPM Packages        
Policy RPM                    selinux-policy-2.4.6-30.el5
Selinux Enabled               True
Policy Type                   targeted
MLS Enabled                   True
Enforcing Mode                Permissive
Plugin Name                   plugins.allow_execmod
Host Name                     nagios
Platform                      Linux nagios 2.6.18-8.el5 #1 SMP Thu Mar 15
                              19:57:35 EDT 2007 i686 i686
Alert Count                   3
Line Numbers                  

Raw Audit Messages            

avc: denied { execmod } for comm="httpd" dev=sda3 egid=0 euid=0
exe="/usr/local/apache2/bin/httpd" exit=0 fsgid=0 fsuid=0 gid=0 items=0
name="libphp5.so" path="/usr/local/apache2/modules/libphp5.so" pid=31706
scontext=user_u:system_r:unconfined_t:s0 sgid=0
subj=user_u:system_r:unconfined_t:s0 suid=0 tclass=file
tcontext=system_u:object_r:lib_t:s0 tty=pts0 uid=0

注意红色字体：大体的意思是 您需要改变libphp5.so 的相应权限。
使用命令：
chcon -t textrel_shlib_t /usr/local/apache2/modules/libphp5.so

 我运气不好哈，加入后还是启不来：
httpd: Syntax error on line 232 of /usr/local/apache2/conf/httpd.conf: API module structure 'php5_module' in file /usr/local/apache2/modules/libphp5.so is garbled - expected signature 41503232 but saw 41503230 - perhaps this is not an Apache module DSO, or was compiled for a different Apache version?

二：大家看最后一行。 or was compiled for a different Apache version?
 或编译不同的apache版本。

OK  换成 apache 2.0 一切搞定。


关于如上的方法，启不动，查看日志，再按日志里的命令操作，接着又会得到提示。继续操作。就可以完成安装。

net-snmp 在selinux开启的状态下也无法启动。需要用上面的方法来解决。或者直接关闭selinux 官网不推荐这么做。


一点小技巧。就到这吧。

更多selinux 相关知识点：
[url]http://www.ibm.com/developerworks/cn/linux/l-selinux.html[/url]
IBM的我感觉写得挺好。