A certain memory configuration has four levels M1I M2I M3 and M4 with hit ratiosof M.7I M.85I M.97I 1.M respectively. A program P makes 3MMM references to thismemory system. Calculate the exact number of references Ri made by P to eachlevel of memoryI Mi.
Google’s Native Client (NaCl) is a technology designed to allow untrusted code to run securely in a Web browser . The primary advantage is speed, but there are many security issues, some of which are reminiscent of issues faced by NGSCB.
a. Outline the NaCl security architecture.
b. NaCl uses a “trampoline” to transfer control from untrusted code to trusted code. Explain how this works.
c. Compare and contrast the security approach used in NaCl with each of the following: Xax, CFI, Active X.