Merge tag 'sched_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-microblaze.git] / net / can / isotp.c

diff --git a/net/can/isotp.c b/net/can/isotp.c
index 253b244..be6183f 100644 (file)
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -143,10 +143,14 @@ struct isotp_sock {
        u32 force_tx_stmin;
        u32 force_rx_stmin;
        struct tpcon rx, tx;
-       struct notifier_block notifier;
+       struct list_head notifier;
        wait_queue_head_t wait;
 };
 
+static LIST_HEAD(isotp_notifier_list);
+static DEFINE_SPINLOCK(isotp_notifier_lock);
+static struct isotp_sock *isotp_busy_notifier;
+
 static inline struct isotp_sock *isotp_sk(const struct sock *sk)
 {
        return (struct isotp_sock *)sk;
@@ -1013,7 +1017,14 @@ static int isotp_release(struct socket *sock)
        /* wait for complete transmission of current pdu */
        wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
 
-       unregister_netdevice_notifier(&so->notifier);
+       spin_lock(&isotp_notifier_lock);
+       while (isotp_busy_notifier == so) {
+               spin_unlock(&isotp_notifier_lock);
+               schedule_timeout_uninterruptible(1);
+               spin_lock(&isotp_notifier_lock);
+       }
+       list_del(&so->notifier);
+       spin_unlock(&isotp_notifier_lock);
 
        lock_sock(sk);
 
@@ -1317,21 +1328,16 @@ static int isotp_getsockopt(struct socket *sock, int level, int optname,
        return 0;
 }
 
-static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
-                         void *ptr)
+static void isotp_notify(struct isotp_sock *so, unsigned long msg,
+                        struct net_device *dev)
 {
-       struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-       struct isotp_sock *so = container_of(nb, struct isotp_sock, notifier);
        struct sock *sk = &so->sk;
 
        if (!net_eq(dev_net(dev), sock_net(sk)))
-               return NOTIFY_DONE;
-
-       if (dev->type != ARPHRD_CAN)
-               return NOTIFY_DONE;
+               return;
 
        if (so->ifindex != dev->ifindex)
-               return NOTIFY_DONE;
+               return;
 
        switch (msg) {
        case NETDEV_UNREGISTER:
@@ -1357,7 +1363,28 @@ static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
                        sk->sk_error_report(sk);
                break;
        }
+}
 
+static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
+                         void *ptr)
+{
+       struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+       if (dev->type != ARPHRD_CAN)
+               return NOTIFY_DONE;
+       if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
+               return NOTIFY_DONE;
+       if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
+               return NOTIFY_DONE;
+
+       spin_lock(&isotp_notifier_lock);
+       list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
+               spin_unlock(&isotp_notifier_lock);
+               isotp_notify(isotp_busy_notifier, msg, dev);
+               spin_lock(&isotp_notifier_lock);
+       }
+       isotp_busy_notifier = NULL;
+       spin_unlock(&isotp_notifier_lock);
        return NOTIFY_DONE;
 }
 
@@ -1394,8 +1421,9 @@ static int isotp_init(struct sock *sk)
 
        init_waitqueue_head(&so->wait);
 
-       so->notifier.notifier_call = isotp_notifier;
-       register_netdevice_notifier(&so->notifier);
+       spin_lock(&isotp_notifier_lock);
+       list_add_tail(&so->notifier, &isotp_notifier_list);
+       spin_unlock(&isotp_notifier_lock);
 
        return 0;
 }
@@ -1442,6 +1470,10 @@ static const struct can_proto isotp_can_proto = {
        .prot = &isotp_proto,
 };
 
+static struct notifier_block canisotp_notifier = {
+       .notifier_call = isotp_notifier
+};
+
 static __init int isotp_module_init(void)
 {
        int err;
@@ -1451,6 +1483,8 @@ static __init int isotp_module_init(void)
        err = can_proto_register(&isotp_can_proto);
        if (err < 0)
                pr_err("can: registration of isotp protocol failed\n");
+       else
+               register_netdevice_notifier(&canisotp_notifier);
 
        return err;
 }
@@ -1458,6 +1492,7 @@ static __init int isotp_module_init(void)
 static __exit void isotp_module_exit(void)
 {
        can_proto_unregister(&isotp_can_proto);
+       unregister_netdevice_notifier(&canisotp_notifier);
 }
 
 module_init(isotp_module_init);