On Mon, May 17, 2021 at 09:22:50AM +0900, Kuniyuki Iwashima wrote: > +static int reuseport_resurrect(struct sock *sk, struct sock_reuseport *old_reuse, > + struct sock_reuseport *reuse, bool bind_inany) > +{ > + if (old_reuse == reuse) { > + /* If sk was in the same reuseport group, just pop sk out of > + * the closed section and push sk into the listening section. > + */ > + __reuseport_detach_closed_sock(sk, old_reuse); > + __reuseport_add_sock(sk, old_reuse); > + return 0; > + } > + > + if (!reuse) { > + /* In bind()/listen() path, we cannot carry over the eBPF prog > + * for the shutdown()ed socket. In setsockopt() path, we should > + * not change the eBPF prog of listening sockets by attaching a > + * prog to the shutdown()ed socket. Thus, we will allocate a new > + * reuseport group and detach sk from the old group. > + */ For the reuseport_attach_prog() path, I think it needs to consider the reuse->num_closed_socks != 0 case also and that should belong to the resurrect case. For example, when sk_unhashed(sk) but sk->sk_reuseport == 0.