opcodetester

Sorry - the presentation was never recorded. There's more information in the GitHub repo, however: https://github.com/cattius/opcodetester.

The final thesis behind this slide deck is alongside it in the repo: https://github.com/cattius/opcodetester/

Associated GitHub repository with more information: https://github.com/cattius/opcodetester I know next to nothing about processors at this level, but I wonder if it would be possible for a skilled engineer to try to find these instructions by scrutinizing the actual physical instruction decoder on the chip and/or inspect the processor's microcode. Are these things possible to do? If they are, is it feasible to reverse engineer them?

Author here - the aim of this project was to explore exactly why such opcodes are problematic for security. Even if they're implemented with entirely innocent intentions - e.g. for debug+verification purposes - they can lead to vulnerabilities in operating systems, emulators, and hypervisors. They induce edge cases which developers can't protect against if they don't know they exist in the first place (due to the lack of any public documentation). There's a more thorough writeup of the project here: https://github.com/cattius/opcodetester/blob/master/thesis.p....