free geoip

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
CS604 Operating Systems Assignment 01 Solution Ideas Fall 2014 Due Date 11 Nov 2014
VU Help • House Banner VU Help Virtual University Students - Assignments, Solved Papers, GDB & Exam Help Student Help Forum • Collaborative • Free Support
#1



CS604 Operating Systems Assignment No. 01 Solution and Discussion Fall 2014 Due Date: 14/11/2014


Question 1: (5 Marks)



Being an end user and an administration of any system, there are some privileges that have been given to you, suppose you are going to take the initial test as an operating system developer then interviewer gives you some privileges and asks to elaborate it.

Which of the following instructions should be privileged?



Instructions Name
Privileges allowed by:
Set values of time

Read the Clock

Clear memory

Memory address

System Call

Issue trap instructions

Turn off interrupts

Modify entries in device-status table

Switch from user to kernel mode

Access I/O device



Question 2: (5 Marks)



Some computer systems do not provide a privileged mode (either user mode or kernel mode) of operation in hardware. Is it possible to construct a secure operating system for these computer systems? Write the name of the most secure operating system and justify your answer with solid reasons also tell either it is possible or not.


[B]
Ideal Solution

Top 10 Most Secure Operating Systems

The security of a given anything, even operating systems (OS), tends to be a difficult or even controversial issue to examine. The only, truly secure operating systems are those that lack contact to the outside world (e.g., a DVD player's firmware). As for any other OS, they'll inevitably have some sort of vulnerability or weakness that can be exploited. In fact, any networked OS can be exposed by careful abuse of its configuration—no exceptions. All the same, here are the top ten most secure operating systems on the planet today.

Another important fact is how fast the vendor is to release a patch when a vulnerability has been discovered.
Recently the more popular Bash shellshock and Openssl Heartbleed shows that.
1. OpenBSD:

By default, this is the most secure general purpose operating system out there. The proof in the pudding? The fact that it suffered only two remote attack vulnerabilities in the last decade serves as solid evidence of its stringent security and strict auditing policy. Moreover, OpenBSD lacks a large enough attack surface (care of running numerous web applications) for hackers to exploit.
2. Linux:

Linux is a superior operating system. When customized it can be set up to extremely secure. Linux has an impressive vulnerability patching policy.
3. Mac OS X:

This Apple-made OS handles user permissions better than, say Windows XP, but it still contains an indecent number of vulnerabilities and remote exploits in its systems. That, coupled with Apple's slow response to many of its security issues, has landed this operating system at the bottom of this list.
4. Windows Server 2008:

Say what you will about a Microsoft operating system's security; at the very least, they know how to improve and they've gone through the very worst security threats that the Internet can dish out. This iteration of Windows Server has improved backup and recovery, user account control, web server (IIS) role, and server role security configuration.

5. Windows Server 2000:

This operating system is so secure that it took nearly a decade before Microsoft can come up with a better one. This OS for network servers, notebook computers, and corporate workstations continues to get monthly security patches even after nine years since its release.

6. Windows 8:

Microsoft attempted to fix the security issues that has plagued Windows 95, 98, ME, and XP, but they ended up alienating consumers instead. The main complaints that people aimed against the polarizing OS—confusing security policies and the lack of backward compatibility with older applications—were actually security measures that were supposed to make Vista a lot more protected from breaches and hacker penetrations.
7. Windows Server 2003:

The good news is that Windows Server 2003 is still a more secure OS than Windows XP. The bad news is that, security-wise, it's even worse than its earlier prototype, Windows Server 2000. Nevertheless, it features competent security improvements like default disabling of vulnerable services and a built-in firewall.
8. Windows XP:

It became one of Microsoft's greatest and most long-running releases (mostly because of Vista's failure to connect to the general Windows-using consumer base). Tragically, it's also one of the most non-secure operating systems of all time as well.Because this OS runs a lot of network services by default and allows users to access full privileges by default, it also gets hacked and breached on a nigh-daily basis by default as well.
9. HP-UX 11i:

Even though it's not one of the most commercially successful operating systems in the market today, this Unix-based Hewlett-Packard OS has been included in this list because of its superior security policies to several more popular operating systems (namely, Mac OS X, Solaris, and Linux).
10. Solaris:

This Sun Microsystems Unix-OS variant is on the lower notches of this article's security hierarchy because it's not inherently security-focused. Because of certain business-related circumstances as well, most of the Solaris source code has already been published via the OpenSolaris project.
Always install the latest patches for the Operating System that you are running.

[/B]

0300-9520262
Get solution in 24 hour
|cpmputer & internetConfusedmileys81:[SIZE="4"][SIZE="3"]....[/SIZE][/SIZE]
Reply
#2
Question#1:

Which of the following instructions should be privileged?

a. Set value of time.

b. Read the clock.

c. Clear memory.

d. Issue a trap instruction.

e. Turn off interrupts.

f. Modify entries in device-status table.

g. Switch from user to kernel mode.

h. Access I/O device.

Answer:

The following operations need to be privileged: Set value of timer, clear memory, turn off interrupts, modify entries in device-status table, access I/O device. The rest can be performed in user mode.



Explanation:

Which of the following instructions should be privileged? why or why not

a) Switch from user to kernel mode

Unprivileged because it's how applications invoke system calls.

The catch is the application cannot control where the program counter goes when this switch happens.

b) Read the clock

Unprivileged, every process should be able to read the clock.

c) Turn off interrupts

Privileged so that a process cannot monopolize the CPU



Question#2: Some computer systems do not provide a privileged mode of operation in hardware. Consider whether it is possible to construct a secure operating system for these computers.

Give arguments both that it is and that it is not possible.

Answer:

An operating system for a machine of this type would need to remain in control

(Or monitor mode) at all times. This could be accomplished by two methods:

1). Software interpretation of all user programs (like some BASIC APL, and LISP systems, for example) the software interpreter would provide, in software, what the hardware does not provide.

2). require meant that all programs be written in high-level languages so that all object code is compiler-produced. The compiler would generate (either in-line or by function calls) the protection checks that the hardware is missing.

0300-9520262
Get solution in 24 hour
|cpmputer & internetConfusedmileys81:[SIZE="4"][SIZE="3"]....[/SIZE][/SIZE]
Reply


Possibly Related Threads…
Thread Author Replies Views Last Post
  VU Fall 2026 Assignments: How to Write Solutions That Get Full Marks (Complete Guide) admin 0 10 11-03-2026, 05:22 PM
Last Post: admin
  SEO in Simple Words: How a VU Student Can Write a Clearer Assignment or Blog Post admin 0 31 11-01-2026, 05:11 AM
Last Post: admin
  Cs403 Assignment 3 Helping material May 8,2010 viki 1 5,259 04-28-2020, 03:19 PM
Last Post: ClaireBeauc
  cs301 assignment no 3 Solution 20 January 2016 Vuhelper 0 11,123 01-20-2016, 03:32 PM
Last Post: Vuhelper
  CS201 Assignment vo 3 Solution 20th January 2016 Vuhelper 2 2,641 01-20-2016, 03:28 PM
Last Post: Vuhelper
  CS101 Assignment no 3 Solution 20th January 2016 Vuhelper 0 2,321 01-20-2016, 03:25 PM
Last Post: Vuhelper
  SOC101 INTRODUCTION TO SOCIOLOGY assignment no 3 Solution 20 January 2016 Vuhelper 0 1,906 01-20-2016, 03:19 PM
Last Post: Vuhelper
  CS402 Assignment No 4 Solution & Discussion Xpert 0 2,139 08-01-2015, 02:33 AM
Last Post: Xpert
  cs101 Assignment No. 1 Solution 21 may spring 2015 semester Xpert 0 2,949 05-21-2015, 12:41 AM
Last Post: Xpert
  Assignment solution eng 301 due date 20 may 2015 rumesa khan 3 4,573 05-20-2015, 01:34 AM
Last Post: Xpert

Forum Jump:


Users browsing this thread: 1 Guest(s)
VU Help • House Banner VU Help Virtual University Students - Assignments, Solved Papers, GDB & Exam Help Student Help Forum • Collaborative • Free Support