1. Respond to the allegation "An operating system requires no protection for its executable code (in memory) because that code s a duplicate of code maintained on disk."
2. 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?
3. Why should the directory of one user not be generally accessible to other users (not even for read-only access)?
4. File access control relates largely to the secrecy dimension of security. What is the relationship between an access control matrix and the integrity of the objects to which access is being controlled?