LFS, round #4

Haven’t made any progress for a couple of weeks but things came together and instrumenting libc works as expected. One example demonstrated in section 12.2.2, chapter 12 of the BPF Performance book is attempting to instrument bash compiled without frame pointers where you only see a call to the read function.

Instrumenting bash which has been built with -fomit-frame-pointer.

Compiling with -fno-omit-frame-pointer produces a stack trace, within bash but the first frame is unresolved if libc isn’t also built with it, resulting in a hexadecimal address rather than showing a call to _start.

stack trace from bash on system with bash and libc built with -fno-omit-frame-pointer.

I’m going to look at integrating ZFS support next but I’m thinking of sharing a build as-is for the benefit of anyone wanting to work through the BPF Performance book.