List two disadvantages of using physical separation in a computing system. List two disadvantages of using temporal separation in a computing system.
A directory is also an object to which access should be controlled. Why is it not appropriate to allow users to modify their own directories?
Why should the directory of one user not be generally accessible to other users not even for read-only access?
What are some other modes of access that users might want to apply to code or data, in addition to the common read, write, and execute permission?
Explain how a fence register is used for relocating a user's program.