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Diffstat (limited to 'net/can/bcm.c')
-rw-r--r--net/can/bcm.c59
1 files changed, 46 insertions, 13 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 909b9e684e04..f00176b2a6c3 100644
--- 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;
@@ -1378,20 +1382,15 @@ 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 +1425,28 @@ 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 +1466,9 @@ 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 +1491,14 @@ 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 +1719,10 @@ 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 +1736,14 @@ 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);
}