diff options
Diffstat (limited to 'net/can')
| -rw-r--r-- | net/can/j1939/bus.c | 5 | ||||
| -rw-r--r-- | net/can/j1939/j1939-priv.h | 1 | ||||
| -rw-r--r-- | net/can/j1939/main.c | 3 | ||||
| -rw-r--r-- | net/can/j1939/socket.c | 52 |
4 files changed, 60 insertions, 1 deletions
diff --git a/net/can/j1939/bus.c b/net/can/j1939/bus.c index 39844f14eed8..797719cb227e 100644 --- a/net/can/j1939/bus.c +++ b/net/can/j1939/bus.c @@ -290,8 +290,11 @@ int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa) if (!ecu) ecu = j1939_ecu_create_locked(priv, name); err = PTR_ERR_OR_ZERO(ecu); - if (err) + if (err) { + if (j1939_address_is_unicast(sa)) + priv->ents[sa].nusers--; goto done; + } ecu->nusers++; /* TODO: do we care if ecu->addr != sa? */ diff --git a/net/can/j1939/j1939-priv.h b/net/can/j1939/j1939-priv.h index 31a93cae5111..81f58924b4ac 100644 --- a/net/can/j1939/j1939-priv.h +++ b/net/can/j1939/j1939-priv.h @@ -212,6 +212,7 @@ void j1939_priv_get(struct j1939_priv *priv); /* notify/alert all j1939 sockets bound to ifindex */ void j1939_sk_netdev_event_netdown(struct j1939_priv *priv); +void j1939_sk_netdev_event_unregister(struct j1939_priv *priv); int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk); void j1939_tp_init(struct j1939_priv *priv); diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c index 7e8a20f2fc42..3706a872ecaf 100644 --- a/net/can/j1939/main.c +++ b/net/can/j1939/main.c @@ -377,6 +377,9 @@ static int j1939_netdev_notify(struct notifier_block *nb, j1939_sk_netdev_event_netdown(priv); j1939_ecu_unmap_all(priv); break; + case NETDEV_UNREGISTER: + j1939_sk_netdev_event_unregister(priv); + break; } j1939_priv_put(priv); diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index 3d8b588822f9..88e7160d4248 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -521,6 +521,9 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len) ret = j1939_local_ecu_get(priv, jsk->addr.src_name, jsk->addr.sa); if (ret) { j1939_netdev_stop(priv); + jsk->priv = NULL; + synchronize_rcu(); + j1939_priv_put(priv); goto out_release_sock; } @@ -1300,6 +1303,55 @@ void j1939_sk_netdev_event_netdown(struct j1939_priv *priv) read_unlock_bh(&priv->j1939_socks_lock); } +void j1939_sk_netdev_event_unregister(struct j1939_priv *priv) +{ + struct sock *sk; + struct j1939_sock *jsk; + bool wait_rcu = false; + +rescan: /* The caller is holding a ref on this "priv" via j1939_priv_get_by_ndev(). */ + read_lock_bh(&priv->j1939_socks_lock); + list_for_each_entry(jsk, &priv->j1939_socks, list) { + /* Skip if j1939_jsk_add() is not called on this socket. */ + if (!(jsk->state & J1939_SOCK_BOUND)) + continue; + sk = &jsk->sk; + sock_hold(sk); + read_unlock_bh(&priv->j1939_socks_lock); + /* Check if j1939_jsk_del() is not yet called on this socket after holding + * socket's lock, for both j1939_sk_bind() and j1939_sk_release() call + * j1939_jsk_del() with socket's lock held. + */ + lock_sock(sk); + if (jsk->state & J1939_SOCK_BOUND) { + /* Neither j1939_sk_bind() nor j1939_sk_release() called j1939_jsk_del(). + * Make this socket no longer bound, by pretending as if j1939_sk_bind() + * dropped old references but did not get new references. + */ + j1939_jsk_del(priv, jsk); + j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa); + j1939_netdev_stop(priv); + /* Call j1939_priv_put() now and prevent j1939_sk_sock_destruct() from + * calling the corresponding j1939_priv_put(). + * + * j1939_sk_sock_destruct() is supposed to call j1939_priv_put() after + * an RCU grace period. But since the caller is holding a ref on this + * "priv", we can defer synchronize_rcu() until immediately before + * the caller calls j1939_priv_put(). + */ + j1939_priv_put(priv); + jsk->priv = NULL; + wait_rcu = true; + } + release_sock(sk); + sock_put(sk); + goto rescan; + } + read_unlock_bh(&priv->j1939_socks_lock); + if (wait_rcu) + synchronize_rcu(); +} + static int j1939_sk_no_ioctlcmd(struct socket *sock, unsigned int cmd, unsigned long arg) { |