This test is similar to test_icmp_send_unreach_cgroup but checks that, in case of recursion, meaning that the BPF program calling the kfunc was re-triggered by the icmp_send done by the kfunc, the kfunc will stop early and return -EBUSY. The test attaches to the root cgroup to ensure the ICMP packet generated by the kfunc re-triggers the BPF program. Signed-off-by: Mahe Tardy <mahe.tardy@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Reviewed-by: Jordan Rife <jordan@jrife.io> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://lore.kernel.org/bpf/20260709144900.245904-5-mahe.tardy@gmail.com