title: Multiple ebpf hooks cgroup_skb
body: <p>I have basic question on ebpf behavior when multiple ebpf hooks are loaded(not using chaining) simultaneously in kernel. Are all of those hooks invoked? For example, I loaded my ebpf program which has cgroup_skb/ingress hook. The ebpf hooks functions loaded by my program are not getting invoked by kernel during packet ingress. When I list loaded programs on &quot;Linux 5.13.0-30-generic&quot;, I see that systemd has already loaded cgroup_skb/ingress hooks by default. I do understand why these cgroup/skb hooks are loaded by systemd. My question is specifically on kernel's behavior when multiple hooks of same type(cgroup_skb/ingress) are loaded.</p>