Does anyone remember how the lander for the Mars Pathfinder mission kept spontaneously rebooting, losing data and cutting off transmissions? Well, engineers finally figured out what the flaw was, and it turns out to have been a common programming problem called priority inversion. Fascinating.

I have such pathetic gadget envy… anyone out there who wants to send me a Palm m505 can feel damn free to do so, quickly.

Forget Ebonics — the future is in Bushonics. “‘We shouldn’t be cutting down the pie smaller,’ Shaw says with quiet dignity. ‘We ought to make the pie higher.’”

Solar Designer (why the hell does this person use a pseudonym?) has published a passive analysis of Secure Shell traffic. I haven’t yet digested the whole thing, but it appears that there are a slew of small vulnerabilities, none of which are huge, but which together could cause problems. Patches are all included.

Who knew that smearing yourself with herbs for two weeks doesn’t make you bulletproof?

It’s time to feel so, so sorry for all of our Congresspeople — they get too much email, and seem to feel overburdened by the need to respond to the people who voted them into office. (Granted, there are a lot of messages from people who aren’t constituents of a particular Congressperson, but still, it’s their job to respond to the people in their districts, and whatever they need to do to make that happen, it’s their responsibility to do so.)

TiVo had a prime time debut on 60 Minutes last night, and its stock shot up 26% as a result. People really are kneejerk investors; that being said, TiVo really is an amazing product.


Wow… It is really hard to get to the reply window now….

I wouldn’t say the Pathfinder problem was “finally” discovered. Keep in mind that the priority inversion problem was fixed on the fly; the paper regarding the topic was released within six months of the problem. That is a very nice turnaround. Priority inversion is a fairly basic element of real-time programming; the original paper was written in 1990. It is quite embarrasing that they didn’t program the system with this feature. However, I found that the discussion about the fix was amazing. It is a good lesson on removing (or keeping) “debugging” functionality.

I was taught by two of the three professors at CMU who wrote the paper regarding priority inversion. Raj Rajkumar was a really great professor. The class I had with him was on real-time Mach. This variant of Mach added real-time extensions to the 3.0 kernel. Interestingly, the 3.0 kernel is the basis for Apple’s MacOS X. I would be a bit surprised if the real-time work did not make it into Apple’s MacOS X. Real-time is very useful for playing movies with sychronized audio and video. It is also handy if you want to play multiple movies at the same time and have them play at the same quality (equal number of dropped frames).

Re: SSH—I’ll be very interested to see an actual exploit based on the code. There are definately vulnerabilities in SSH v1.0, but they seem quite difficult to exploit.


• Posted by: Sam Greenfield on Mar 21, 2001, 1:05 PM
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