Only update psock->saved_* if psock->sk_proto has not been initialized yet. This allows us to get rid of tcp_bpf_reinit_sk_prot.
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| @@ -347,11 +347,23 @@ static inline void sk_psock_update_proto(struct sock *sk, · 346 unmodified lines | |||
| 347 | struct sk_psock *psock, | 347 | struct sk_psock *psock, |
| 348 | struct proto *ops) | 348 | struct proto *ops) |
| 349 | { | 349 | { |
| 350 | psock->saved_unhash = sk->sk_prot->unhash; | 350 | /* Initialize saved callbacks and original proto only once, since this |
| 351 | psock->saved_close = sk->sk_prot->close; | 351 | * function may be called multiple times for a psock, e.g. when |
| 352 | psock->saved_write_space = sk->sk_write_space; | 352 | * psock->progs.msg_parser is updated. |
| 353 | * | ||
| 354 | * Since we've not installed the new proto, psock is not yet in use and | ||
| 355 | * we can initialize it without synchronization. | ||
| 356 | */ | ||
| 357 | if (!psock->sk_proto) { | ||
| 358 | struct proto *orig = READ_ONCE(sk->sk_prot); | ||
| 359 | |||
| 360 | psock->saved_unhash = orig->unhash; | ||
| 361 | psock->saved_close = orig->close; | ||
| 362 | psock->saved_write_space = sk->sk_write_space; | ||
| 363 | |||
| 364 | psock->sk_proto = orig; | ||
| 365 | } | ||
| 353 | 366 | ||
| 354 | psock->sk_proto = sk->sk_prot; | ||
| 355 | /* Pairs with lockless read in sk_clone_lock() */ | 367 | /* Pairs with lockless read in sk_clone_lock() */ |
| 356 | WRITE_ONCE(sk->sk_prot, ops); | 368 | WRITE_ONCE(sk->sk_prot, ops); |
| 357 | } | 369 | } |