TL;DR Working on talus-process-monitor (Rust userspace + libbpf/C eBPF) I kept bumping into the same three walls: CO-RE field offsets shifting between kernel versions, the verifier refusing anything that looks like an unbounded loop, and map access patterns that get rejected at load time. All three are design constraints, not compiler annoyances. This post is what changed in my approach once I stopped fighting them. CO-RE relocation is a promise you have to verify Portable ...