Back when Intel introduced the 80286, they didn't quite document everything right away. Errata were needed. Then the 80386 changed things. And then someone convinced them to add just one more feature at the last minute, which didn't get documented properly again.
The History of a Security Hole takes a look at the problems introduced by the I/O Permission Bitmap (IOPB) in the 80286, and how fallout from the implementation caused a security hole in all versions of OpenBSD up to 6.3 and NetBSD up to 4.4.
Conclusion? This programming thing is hard.
(Score: 2) by darkfeline on Friday September 07 2018, @07:24PM (1 child)
>That extra 4x development cost may be worth it for certain things.
That's what I said. Most things don't need it.
>And today just about everything in the world depends on [microprocessors] working.
Yes, today. Not twenty years ago, not ten years ago to most people (SN is not most people), and there are still people today who don't realize the significance of microcomputing devices, and there are still a lot of people who haven't touched a computing device. Take the average company board, are they going to authorize spending an order of magnitude more on computers that are "less buggy" when they see competitors using cheap shit?
Join the SDF Public Access UNIX System today!
(Score: 2) by DannyB on Friday September 07 2018, @07:30PM
You're right that you said most things.
About microprocessors. If there is a development cost of x, which is 20% total cost for 80% correctness, and then 4x which is 80% of cost for remaining 20% correctness, then that 4x element is spread across billions of processors.
The lower I set my standards the more accomplishments I have.