--filter-trace-tc option doesn't work with Cilium about pwru

[hwchiu]

@brb
Thanks for the reply and unfortunately, I'm not able to upgrade the cilium version in that environment, but
I will try to reproduce the issue in my home lab and then try the latest cilium to see if the issue still exists.

[brb]

@hwchiu Thanks for the issue! Have you tried running with more recent Cilium version?

[garyhuang123]

Encountered the same issue on cilium 1.11.5, kernel 5.6

[wdullaer]

I just ran into this as well with an ebpf program I wrote.
I compiled it with clang and embedded the btf information.
Clearly the subprog in question exists.

What kind of extra info would be needed to investigate this? I can try to reduce my program to the minimal repro case.

[brb]

What kind of extra info would be needed to investigate this? I can try to reduce my program to the minimal repro case.

Which kernel and what Cilium vsn, what distro and how do you run K8s?

[Asphaltt]

The PR #383 fixes this issue.

This issue will happen when the very first function name in BTF info is out of the traced bpf prog.

I reproduce this case, and fix it by PR #383 .

sudo ./pwru --filter-trace-tc --filter-func '.*ip_out.*' --output-meta --output-tuple --output-limit-lines 10 icmp
2024/06/12 13:23:08 Failed to trace TC: failed to load objects: Verifier error: load program: invalid argument:
	func#0 @0
	func#1 @40
	func#2 @967
	func#3 @1024
	Subprog phy_on_ingress doesn't exist
	processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0

program fentry_tc: load program: invalid argument: Subprog phy_on_ingress doesn't exist (5 line(s) omitted)