Merge remote-tracking branch 'torvalds/master' into perf/core

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

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 909b9e6..f3e4d95 100644 (file)
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -125,7 +125,7 @@ struct bcm_sock {
        struct sock sk;
        int bound;
        int ifindex;
-       struct notifier_block notifier;
+       struct list_head notifier;
        struct list_head rx_ops;
        struct list_head tx_ops;
        unsigned long dropped_usr_msgs;
@@ -133,6 +133,10 @@ struct bcm_sock {
        char procname [32]; /* inode number in decimal with \0 */
 };
 
+static LIST_HEAD(bcm_notifier_list);
+static DEFINE_SPINLOCK(bcm_notifier_lock);
+static struct bcm_sock *bcm_busy_notifier;
+
 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
 {
        return (struct bcm_sock *)sk;
@@ -402,6 +406,7 @@ static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
                if (!op->count && (op->flags & TX_COUNTEVT)) {
 
                        /* create notification to user */
+                       memset(&msg_head, 0, sizeof(msg_head));
                        msg_head.opcode  = TX_EXPIRED;
                        msg_head.flags   = op->flags;
                        msg_head.count   = op->count;
@@ -439,6 +444,7 @@ static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
        /* this element is not throttled anymore */
        data->flags &= (BCM_CAN_FLAGS_MASK|RX_RECV);
 
+       memset(&head, 0, sizeof(head));
        head.opcode  = RX_CHANGED;
        head.flags   = op->flags;
        head.count   = op->count;
@@ -560,6 +566,7 @@ static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
        }
 
        /* create notification to user */
+       memset(&msg_head, 0, sizeof(msg_head));
        msg_head.opcode  = RX_TIMEOUT;
        msg_head.flags   = op->flags;
        msg_head.count   = op->count;
@@ -1378,20 +1385,15 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 /*
  * notification handler for netdevice status changes
  */
-static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
-                       void *ptr)
+static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
+                      struct net_device *dev)
 {
-       struct net_device *dev = netdev_notifier_info_to_dev(ptr);
-       struct bcm_sock *bo = container_of(nb, struct bcm_sock, notifier);
        struct sock *sk = &bo->sk;
        struct bcm_op *op;
        int notify_enodev = 0;
 
        if (!net_eq(dev_net(dev), sock_net(sk)))
-               return NOTIFY_DONE;
-
-       if (dev->type != ARPHRD_CAN)
-               return NOTIFY_DONE;
+               return;
 
        switch (msg) {
 
@@ -1426,7 +1428,28 @@ static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
                                sk->sk_error_report(sk);
                }
        }
+}
 
+static int bcm_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(bcm_busy_notifier)) /* Check for reentrant bug. */
+               return NOTIFY_DONE;
+
+       spin_lock(&bcm_notifier_lock);
+       list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
+               spin_unlock(&bcm_notifier_lock);
+               bcm_notify(bcm_busy_notifier, msg, dev);
+               spin_lock(&bcm_notifier_lock);
+       }
+       bcm_busy_notifier = NULL;
+       spin_unlock(&bcm_notifier_lock);
        return NOTIFY_DONE;
 }
 
@@ -1446,9 +1469,9 @@ static int bcm_init(struct sock *sk)
        INIT_LIST_HEAD(&bo->rx_ops);
 
        /* set notifier */
-       bo->notifier.notifier_call = bcm_notifier;
-
-       register_netdevice_notifier(&bo->notifier);
+       spin_lock(&bcm_notifier_lock);
+       list_add_tail(&bo->notifier, &bcm_notifier_list);
+       spin_unlock(&bcm_notifier_lock);
 
        return 0;
 }
@@ -1471,7 +1494,14 @@ static int bcm_release(struct socket *sock)
 
        /* remove bcm_ops, timer, rx_unregister(), etc. */
 
-       unregister_netdevice_notifier(&bo->notifier);
+       spin_lock(&bcm_notifier_lock);
+       while (bcm_busy_notifier == bo) {
+               spin_unlock(&bcm_notifier_lock);
+               schedule_timeout_uninterruptible(1);
+               spin_lock(&bcm_notifier_lock);
+       }
+       list_del(&bo->notifier);
+       spin_unlock(&bcm_notifier_lock);
 
        lock_sock(sk);
 
@@ -1692,6 +1722,10 @@ static struct pernet_operations canbcm_pernet_ops __read_mostly = {
        .exit = canbcm_pernet_exit,
 };
 
+static struct notifier_block canbcm_notifier = {
+       .notifier_call = bcm_notifier
+};
+
 static int __init bcm_module_init(void)
 {
        int err;
@@ -1705,12 +1739,14 @@ static int __init bcm_module_init(void)
        }
 
        register_pernet_subsys(&canbcm_pernet_ops);
+       register_netdevice_notifier(&canbcm_notifier);
        return 0;
 }
 
 static void __exit bcm_module_exit(void)
 {
        can_proto_unregister(&bcm_can_proto);
+       unregister_netdevice_notifier(&canbcm_notifier);
        unregister_pernet_subsys(&canbcm_pernet_ops);
 }