More Ghostwrite Bugginess with RISCVuzz

In my previous blog about the Ghostwrite vulnerability in the Alibaba T-Head C910 RISC-V-based processor, I noted that the authors of the paper had found more than just that one bug. The additional bugs are worth their own write-up, as they offer some more examples of what looks to be poor testing.

Continue reading “More Ghostwrite Bugginess with RISCVuzz”

The ESA Schiaparelli Crash & Simulation

Back in 2016, the European Space Agency (ESA) lost the Schiaparelli Mars lander during its descent to the surface on Mars. From a software engineering and testing perspective, the story of why the landing failed (see for example the ESA final analysis, Space News, or the BBC) is instructive. It comes down to how software is written and tested to deal with unexpected inputs in unexpected circumstances. I published a blog post about this right after the event and before the final analysis was available. Thankfully, that has since been retired from its original location-it was a bit too full of speculation that turned out to be incorrect… So here is a mostly rewritten version of the post, quoting the final analysis and with new insights.  

Continue reading “The ESA Schiaparelli Crash & Simulation”