Linux module(s) related to user's permission

Hi all, Can everyone tell me about kernel module(s) that related to permission or privilege of user (root, normal users) in Linux. I want to research about permission module and do some modifications to the kernel. In fact, I want to limit root's privilege on a specific file or folder. So, can

Linux module(s) related to user's permission

Hi all, Can everyone tell me about kernel module(s) that related to permission or privilege of user (root, normal users) in Linux. I want to research about permission module and do some modifications to the kernel. In fact, I want to limit root's privilege on a specific file or folder. So, can