Re: [bpf PATCH 1/2] bpf, sockmap: fix sk->prot unhash op reset
flat view
From: John Fastabend <john.fastabend@gmail.com>
Date: 2021-03-25 02:29:43
Also in:
bpf
Cong Wang wrote:
On Wed, Mar 24, 2021 at 1:59 PM John Fastabend [off-list ref] wrote:quoted
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 47b7c5334c34..ecb5634b4c4a 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c@@ -754,6 +754,12 @@ static void tls_update(struct sock *sk, struct proto *p, ctx = tls_get_ctx(sk); if (likely(ctx)) { + /* TLS does not have an unhash proto in SW cases, but we need + * to ensure we stop using the sock_map unhash routine because + * the associated psock is being removed. So use the original + * unhash handler. + */ + WRITE_ONCE(sk->sk_prot->unhash, p->unhash); ctx->sk_write_space = write_space; ctx->sk_proto = p;It looks awkward to update sk->sk_proto inside tls_update(), at least when ctx!=NULL.
hmm. It doesn't strike me as paticularly awkward but OK.
What is wrong with updating it in sk_psock_restore_proto() when inet_csk_has_ulp() is true? It looks better to me.
It could be wrong if inet_csk_has_ulp has an unhash callback already assigned. But, because we know inet_csk_has_ulp() really means is_tls_attached() it would be fine.
quoted hunk ↗ jump to hunk
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 6c09d94be2e9..da5dc3ef0ee3 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h@@ -360,8 +360,8 @@ static inline void sk_psock_update_proto(struct sock *sk, static inline void sk_psock_restore_proto(struct sock *sk, struct sk_psock *psock) { - sk->sk_prot->unhash = psock->saved_unhash; if (inet_csk_has_ulp(sk)) { + sk->sk_prot->unhash = psock->sk_proto->unhash; tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space); } else { sk->sk_write_space = psock->saved_write_space;sk_psock_restore_proto() is the only caller of tcp_update_ulp() so should be equivalent.
Agree it is equivalent. I don't mind moving the assignment around if folks think its nicer.
Thanks.