Bringing Record and Replay debugging everywhere on Linux

Summary

21 March 2025 Bringing Record and Replay everywhere I've modified the awesome rr debugger so that it can run without needing access to CPU Hardware Performance counters. This allows rr to be used in many more environments like cloud VMs and containers where access to CPU HW performance counters is usually disabled. Upstream rr requires access to CPU HW performance counters to function, so this is a new feature and opens many additional possibilities to debug your software with rr. I call this variant, Software Counters mode rr. Record and Replay systems like rr deserve to be able to run everywhere and this is my attempt at making this possible ! To build, install and run Software Counters mode rr please visit https://github.com/sidkshatriya/rr.soft Continue reading to understand some of the basic concepts behind Record and Replay and why it is such a powerful technique when debugging programs. What is program record and replay ? Why is it useful ? When you watch a YouTube video, there is the unspoken expectation that when you rewind or go forward an arbitrary number of seconds the video is exactly the same as it had been when it was recorded ! You don't see something new in the video that was never there ! The video and audio is exactly the same. In fact, if the video was slightly different when you replayed it again and again it would be extremely strange. You would probably think you were going mad if the video were slightly different on each replay :-) ! Allowing you to go forwards and backwards in time when viewing a video is critical. Once a video is uploaded to the YouTube website, it is essentially "frozen". This allows anybody to view the same video any number of times and concentrate or learn from parts of the video that are most interesting. From replaying videos to programs Let us shift focus from YouTube videos to computer programs. Let's say you're attempting to run a program again and again because you are facing some errors. When you try to debug an e...