Looking at yourself: Linux Introspection tales

Introspection information, used originally by debuggers, has come a long way into playing a greater role in the functioning of Linux.

Now its used by tracers, profilers, and then by eBPF, in libbpf, in the verifier and other parts of the kernel, being always available and fast to access.

This talk will tell the history of a tool initially used for looking for alignment holes, all the way to being used in the kernel build process, and will touch many aspects of this journey.

Old and new tricks will be described, touching perf, eBPF, rust, clang, you name it.

Arnaldo Carvalho de Melo, Red Hat