php.ini disable_functions 禁用某些函数
需要时注意打开
php-fpm 对应conf user group为root时
ERROR: [pool www] please specify user and group other than root
php-fpm -R
-R, --allow-to-run-as-root
Allow pool to run as root (disabled by default)
disable_functions php-fpm root
原文：http://www.cnblogs.com/jking10/p/5003297.html