Which part of Linux kernel enforces privilege separation and how?
<p>I want to know how privilege separation is enforced by the kernel and the part of kernel that is responsible for this task. </p>

<p>For example, assume there are two processes running -- one at ring 0 and another at ring 3. How does the kernel keep track of the ring number of each process?</p>

<p>Edit: I know about ring numbers. My question is about the part of kernel (module or something) which performs checks on the processes to find out their privilege level. I believe there might be a component of kernel which would check the ring number of a process.</p>