Why Operating Systems are Not Secure and reliable

While reading an IEEE computer society paper I find out some really good points regarding the Operating system security and reliability. Why our TV sets, DVD Players, Mobile phones and other electronic devices are reliable and secure but not our computer system and mostly our operating system. What computer and operating system makers say about this: Computers are flexible, users can change the software and there are some other excuses also, but people using the computers are mostly from the non technical background.

Why Operating systems are Unreliable?

Current operating systems are huge for example Linux kernel has more then 2.5 million lines of code, Microsoft Windows XP has around 4 million lines of code. Studies said there may be 2 to 75 bugs per 1000 lines of executable code.
Current operating systems are getting bigger and bigger in size, this makes software developer to understand the system and after understanding the system to fix problems in the system. These fixes also introduce some new bug in operating system.
Operating system’s 70% code contains device drivers and in device drivers the probability having a bug per 1000 line of executable code is three time higher then the original code.
Isolation is another problem. Modern operating system contains hundreds or thousands of procedures linked together as a single binary program running in kernel mode. Any of the procedure can overwrite the key data structure or any key data. This makes hard to detect the crash.

Some real world examples

Can our operating systems be developed like aircraft carrier, no person know about how aircraft carrier works either, but the subsystems on an aircraft carrier are well isolated. A problem with a clogged toilet cannot affect the missile-launching subsystem.
Modern ships have multiple compartments within the hull; if one compartment springs a leak, only that one is flooded, not the entire hull. Current operating systems are like ships before compartmentalization was invented: Every leak can sink the ship.

I will be continuing to write about the operating system and in upcoming posts I will write some solutions that are given in IEEE computer society website.

Reference Can We Make Operating Systems Reliable and Secure?