•Dual -Mode Operation-sharing system resources requires operating system to ensure that an incorrect program connot cause other programs to execute incorrectly.
-provides hardware support to differenciate atleast up to two modes of operation.
1. User mode-execution done on behalf of a user.
2. Monitor mode-execution done on behalf of a operating system.
•I/O Protection-All i/o instructions are priveleged instructions.
-must ensure that a user program could never gain control
of the computer in monitor mode.
•Memory Protection-Memory protection is a way to control memory access rights on a computer, and is a part of nearly every modern operating system. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug within a process from affecting other processes, or the operating system itself. Memory protection also makes a Rootkit more difficult to implement. Memory protection is a behavior that is distinct from ASLR and the NX bit.
•CPU protection-to prevent a user programs gets stuck in infinite loop and never returning back to the os
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment