Hello :) My BPF program is loaded by `bpf_load_program_xattr` of `libbpf` and then attached to kprobe event using `perf_event_open`, `ioctl(PERF_EVENT_IOC_SET_BPF)` and `ioctl(PERF_EVENT_IOC_ENABLE)`. Then the BPF program is working as I expected. And I wanted to make the BPF program keep working even though the userspace process exits. So I pinned it using `bpf_obj_pin()`. But unfortunately the BPF program is never called after the userspace process exits. I discovered the cause of the failure. The file descriptor of perf event is automatically closed when userspace process exits so objects related to perf event get destroyed. So I tried to find how to pin the fd of perf event, but I got to know that only BPF programs, BPF maps and BPF links are subject to pin. How can I make my BPF program which is attached to kprobe keep working after userspace process exits? regards, Junyeong