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Stack Overflow Could Explain Toyota Vehicles' Unintended Acceleration
New submitter robertchin writes "Michael Barr recently testified in the Bookout v. Toyota Motor Corp lawsuit that the likely cause of unintentional acceleration in the Toyota Camry may have been caused by a stack overflow. Due to recursion overwriting critical data past the end of the stack and into the real time operating system memory area, the throttle was left in an open state and the process that controlled the throttle was terminated. How can users protect themselves from sometimes life endangering software bugs?"
Idiot drivers hit the gas pedal instead of the brake and instead of owning up to their incompetence as a drivers, they blame the car instead. The Toyota sudden acceleration problem disproportionately affects the elderly and inexperienced drivers. It also a uniquely an American problem and it occurred during a deep recession where GM and Chrysler were going bankrupt and Americans needed some FUD against Toyota because supporting American car companies was the jingoism of the day. The toyota sudden acceleration is more of a case study of an American moral panic and mass hysteria perpetrated by the media than it was an engineering problem.
Coming from the aerospace industry, you cannot have software that has bugs. And if there was the possibility of a software bug, you have to prove that you can mitigate the effect in hardware. So just to say "software has bugs...life has risks" isn't an acceptable answer (in my opinion). We have to remember this is not an apples to apples comparison. Just because traditional consumer software always has bugs in it (which are acceptable) doesn't mean they are acceptable in other industries. Considering that the failure puts someone's life at risk, I would think it should be considered unacceptable in automotive industry as well.
If you want your cars to be as expensive as a 747, then you can attain that goal. I used to work in the automotive industry designing embedded software for engine management systems. At that time, no automotive company would pay more than $100 for the Engine Control Unit. Probably 60% of the code was written to manage failures (both software and hardware), and there were other electronic fail safe mechanisms. But you can't mitigate every possible failure event without introducing costs that would have made the unit orders of magnitude more expensive.
I had my car suddenly accelerate on me before. I was driving along and suddenly the pedal felt really strange and it start accelerating, even when I took my foot off the pedal. I turned off the car and pulled over. Turns out the rubber mat I put in to protect the inside of my car from wet/snow had somehow managed to flop on top of the pedal and pushed it down. When I heard about these Toyotas accelerating on their own, it's the first thing I thought of.