Hello, BPF CO-RE!

Trouble Shooting

clang cannot compile BPF source files

If you cannot build a BPF source file with the following messages:

build/vmlinux.h:4629:20: error: expected member name or ';' after declaration specifiers
        struct cgroup_bpf bpf;
                          ^
<built-in>:284:13: note: expanded from here
#define bpf 1

Then, your clang could be too old. I've confirmed clang-8 cannot build BPF source files but clang-10 can do.

References

• https://www.sartura.hr/blog/simple-ebpf-core-application/
  • repo: https://github.com/sartura/ebpf-hello-world
• BPF Documentation - kernel.org
• BPF CO-RE Reference Guide - nakryiko.com