On Thu, Mar 5, 2026 at 3:32 PM Michal Luczaj <[email protected]> wrote:
>
> Instead of repeating the same (un)locking pattern, reuse
> sock_map_sk_{acquire,release}(). This centralizes the code and makes it
> easier to adapt sockmap to af_unix-specific locking.
>
> Signed-off-by: Michal Luczaj <[email protected]>
> ---
> net/core/sock_map.c | 21 +++++++--------------
> 1 file changed, 7 insertions(+), 14 deletions(-)
>
> diff --git a/net/core/sock_map.c b/net/core/sock_map.c
> index 02a68be3002a..7ba6a7f24ccd 100644
> --- a/net/core/sock_map.c
> +++ b/net/core/sock_map.c
> @@ -353,11 +353,9 @@ static void sock_map_free(struct bpf_map *map)
> sk = xchg(psk, NULL);
> if (sk) {
> sock_hold(sk);
> - lock_sock(sk);
> - rcu_read_lock();
> + sock_map_sk_acquire(sk);
> sock_map_unref(sk, psk);
> - rcu_read_unlock();
> - release_sock(sk);
> + sock_map_sk_release(sk);
> sock_put(sk);
> }
> }
> @@ -1176,11 +1174,9 @@ static void sock_hash_free(struct bpf_map *map)
> */
> hlist_for_each_entry_safe(elem, node, &unlink_list, node) {
> hlist_del(&elem->node);
> - lock_sock(elem->sk);
> - rcu_read_lock();
> + sock_map_sk_acquire(elem->sk);
> sock_map_unref(elem->sk, elem);
> - rcu_read_unlock();
> - release_sock(elem->sk);
> + sock_map_sk_release(elem->sk);
> sock_put(elem->sk);
> sock_hash_free_elem(htab, elem);
> }
> @@ -1676,8 +1672,7 @@ void sock_map_close(struct sock *sk, long timeout)
> void (*saved_close)(struct sock *sk, long timeout);
> struct sk_psock *psock;
>
> - lock_sock(sk);
> - rcu_read_lock();
> + sock_map_sk_acquire(sk);
> psock = sk_psock(sk);
> if (likely(psock)) {
> saved_close = psock->saved_close;
> @@ -1685,16 +1680,14 @@ void sock_map_close(struct sock *sk, long timeout)
> psock = sk_psock_get(sk);
> if (unlikely(!psock))
> goto no_psock;
> - rcu_read_unlock();
> sk_psock_stop(psock);
> - release_sock(sk);
> + sock_map_sk_release(sk);
I think sk_psock_stop() was intentionally put outside
of rcu_read_lock() to not extend the grace period
unnecessarily. e.g. while + __sk_msg_free().
Maybe add __sock_map_sk_release() without
rcu_read_unlock() ?
> cancel_delayed_work_sync(&psock->work);
> sk_psock_put(sk, psock);
> } else {
> saved_close = READ_ONCE(sk->sk_prot)->close;
> no_psock:
> - rcu_read_unlock();
> - release_sock(sk);
> + sock_map_sk_release(sk);
> }
>
> /* Make sure we do not recurse. This is a bug.
>
> --
> 2.52.0
>
