Day 4 at the Recurse Center
- 1 minI woke up really tired today. Pairing all day the yesterday on something totally new to me and the general overwhelmingness of RC probably caught up to me. That aside, Gargi and I returned to the world of ptrace and Go. It’s definitely the kind of project where it doesn’t feel like we’re making that much concrete progress, but I at least am definitely learning a lot just by messing around with it.
Today we were able to write some Go that kicked off a simple script and prints out the number 1 through 100 with a 1 second sleep between each number. We then grab the pid of the counter script, and PTRACE_ATTACH. Then we wait for the counter script to stop and at this point we should theoretically be able to do things with our traced process. We hit a lot of issues though. We had problems were, after waiting, the counter process couldn’t be found by its pid, and didn’t appear to be executing, as we couldn’t see any of the output it should have been printing to the command line. Our goal had been to use PTRACE_SINGLESTEP once the program had stopped to be able to step through a few instructions, but we had a lot of trouble getting it to work. Yesterday we were able to attach and look at different registers, so we were both a bit confused. We messed around with this for a bit but didn’t make any huge breakthroughs.
I’ve learned a lot about debuggers and ptrace, but I’m also excited to shift tomorrow to working on my web stuff a bit more.
Gargi and I read through this series on debuggers and it was super helpful! I think we are tentatively planning on returning to this on Monday.
Andrew Pierce
Software Engineer based in Durham, NC