]> git.karo-electronics.de Git - karo-tx-linux.git/blobdiff - net/core/netpoll.c
tipc: Prevent crash when broadcast link cannot send to all nodes
[karo-tx-linux.git] / net / core / netpoll.c
index e034342c819c6c5b1d16619386ff602d3472ddac..537e01afd81baf1e9bc7269e0c97ca3fb3844ffe 100644 (file)
@@ -49,6 +49,7 @@ static atomic_t trapped;
                (MAX_UDP_CHUNK + sizeof(struct udphdr) + \
                                sizeof(struct iphdr) + sizeof(struct ethhdr))
 
+static void zap_completion_queue(void);
 static void arp_reply(struct sk_buff *skb);
 
 static unsigned int carrier_timeout = 4;
@@ -196,12 +197,15 @@ void netpoll_poll_dev(struct net_device *dev)
 
        service_arp_queue(dev->npinfo);
 
+       zap_completion_queue();
 }
+EXPORT_SYMBOL(netpoll_poll_dev);
 
 void netpoll_poll(struct netpoll *np)
 {
        netpoll_poll_dev(np->dev);
 }
+EXPORT_SYMBOL(netpoll_poll);
 
 static void refill_skbs(void)
 {
@@ -219,11 +223,40 @@ static void refill_skbs(void)
        spin_unlock_irqrestore(&skb_pool.lock, flags);
 }
 
+static void zap_completion_queue(void)
+{
+       unsigned long flags;
+       struct softnet_data *sd = &get_cpu_var(softnet_data);
+
+       if (sd->completion_queue) {
+               struct sk_buff *clist;
+
+               local_irq_save(flags);
+               clist = sd->completion_queue;
+               sd->completion_queue = NULL;
+               local_irq_restore(flags);
+
+               while (clist != NULL) {
+                       struct sk_buff *skb = clist;
+                       clist = clist->next;
+                       if (skb->destructor) {
+                               atomic_inc(&skb->users);
+                               dev_kfree_skb_any(skb); /* put this one back */
+                       } else {
+                               __kfree_skb(skb);
+                       }
+               }
+       }
+
+       put_cpu_var(softnet_data);
+}
+
 static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
 {
        int count = 0;
        struct sk_buff *skb;
 
+       zap_completion_queue();
        refill_skbs();
 repeat:
 
@@ -261,6 +294,7 @@ void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
        unsigned long tries;
        struct net_device *dev = np->dev;
        const struct net_device_ops *ops = dev->netdev_ops;
+       /* It is up to the caller to keep npinfo alive. */
        struct netpoll_info *npinfo = np->dev->npinfo;
 
        if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
@@ -312,6 +346,7 @@ void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
                schedule_delayed_work(&npinfo->tx_work,0);
        }
 }
+EXPORT_SYMBOL(netpoll_send_skb);
 
 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 {
@@ -373,6 +408,7 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 
        netpoll_send_skb(np, skb);
 }
+EXPORT_SYMBOL(netpoll_send_udp);
 
 static void arp_reply(struct sk_buff *skb)
 {
@@ -599,6 +635,7 @@ void netpoll_print_options(struct netpoll *np)
        printk(KERN_INFO "%s: remote ethernet address %pM\n",
                         np->name, np->remote_mac);
 }
+EXPORT_SYMBOL(netpoll_print_options);
 
 int netpoll_parse_options(struct netpoll *np, char *opt)
 {
@@ -691,30 +728,29 @@ int netpoll_parse_options(struct netpoll *np, char *opt)
               np->name, cur);
        return -1;
 }
+EXPORT_SYMBOL(netpoll_parse_options);
 
-int netpoll_setup(struct netpoll *np)
+int __netpoll_setup(struct netpoll *np)
 {
-       struct net_device *ndev = NULL;
-       struct in_device *in_dev;
+       struct net_device *ndev = np->dev;
        struct netpoll_info *npinfo;
-       struct netpoll *npe, *tmp;
+       const struct net_device_ops *ops;
        unsigned long flags;
        int err;
 
-       if (np->dev_name)
-               ndev = dev_get_by_name(&init_net, np->dev_name);
-       if (!ndev) {
-               printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
+       if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
+           !ndev->netdev_ops->ndo_poll_controller) {
+               printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
                       np->name, np->dev_name);
-               return -ENODEV;
+               err = -ENOTSUPP;
+               goto out;
        }
 
-       np->dev = ndev;
        if (!ndev->npinfo) {
                npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
                if (!npinfo) {
                        err = -ENOMEM;
-                       goto put;
+                       goto out;
                }
 
                npinfo->rx_flags = 0;
@@ -726,6 +762,13 @@ int netpoll_setup(struct netpoll *np)
                INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
 
                atomic_set(&npinfo->refcnt, 1);
+
+               ops = np->dev->netdev_ops;
+               if (ops->ndo_netpoll_setup) {
+                       err = ops->ndo_netpoll_setup(ndev, npinfo);
+                       if (err)
+                               goto free_npinfo;
+               }
        } else {
                npinfo = ndev->npinfo;
                atomic_inc(&npinfo->refcnt);
@@ -733,12 +776,37 @@ int netpoll_setup(struct netpoll *np)
 
        npinfo->netpoll = np;
 
-       if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
-           !ndev->netdev_ops->ndo_poll_controller) {
-               printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
+       if (np->rx_hook) {
+               spin_lock_irqsave(&npinfo->rx_lock, flags);
+               npinfo->rx_flags |= NETPOLL_RX_ENABLED;
+               list_add_tail(&np->rx, &npinfo->rx_np);
+               spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+       }
+
+       /* last thing to do is link it to the net device structure */
+       rcu_assign_pointer(ndev->npinfo, npinfo);
+
+       return 0;
+
+free_npinfo:
+       kfree(npinfo);
+out:
+       return err;
+}
+EXPORT_SYMBOL_GPL(__netpoll_setup);
+
+int netpoll_setup(struct netpoll *np)
+{
+       struct net_device *ndev = NULL;
+       struct in_device *in_dev;
+       int err;
+
+       if (np->dev_name)
+               ndev = dev_get_by_name(&init_net, np->dev_name);
+       if (!ndev) {
+               printk(KERN_ERR "%s: %s doesn't exist, aborting.\n",
                       np->name, np->dev_name);
-               err = -ENOTSUPP;
-               goto release;
+               return -ENODEV;
        }
 
        if (!netif_running(ndev)) {
@@ -754,7 +822,7 @@ int netpoll_setup(struct netpoll *np)
                if (err) {
                        printk(KERN_ERR "%s: failed to open %s\n",
                               np->name, ndev->name);
-                       goto release;
+                       goto put;
                }
 
                atleast = jiffies + HZ/10;
@@ -791,7 +859,7 @@ int netpoll_setup(struct netpoll *np)
                        printk(KERN_ERR "%s: no IP address for %s, aborting\n",
                               np->name, np->dev_name);
                        err = -EDESTADDRREQ;
-                       goto release;
+                       goto put;
                }
 
                np->local_ip = in_dev->ifa_list->ifa_local;
@@ -799,38 +867,25 @@ int netpoll_setup(struct netpoll *np)
                printk(KERN_INFO "%s: local IP %pI4\n", np->name, &np->local_ip);
        }
 
-       if (np->rx_hook) {
-               spin_lock_irqsave(&npinfo->rx_lock, flags);
-               npinfo->rx_flags |= NETPOLL_RX_ENABLED;
-               list_add_tail(&np->rx, &npinfo->rx_np);
-               spin_unlock_irqrestore(&npinfo->rx_lock, flags);
-       }
+       np->dev = ndev;
 
        /* fill up the skb queue */
        refill_skbs();
 
-       /* last thing to do is link it to the net device structure */
-       ndev->npinfo = npinfo;
+       rtnl_lock();
+       err = __netpoll_setup(np);
+       rtnl_unlock();
 
-       /* avoid racing with NAPI reading npinfo */
-       synchronize_rcu();
+       if (err)
+               goto put;
 
        return 0;
 
- release:
-       if (!ndev->npinfo) {
-               spin_lock_irqsave(&npinfo->rx_lock, flags);
-               list_for_each_entry_safe(npe, tmp, &npinfo->rx_np, rx) {
-                       npe->dev = NULL;
-               }
-               spin_unlock_irqrestore(&npinfo->rx_lock, flags);
-
-               kfree(npinfo);
-       }
 put:
        dev_put(ndev);
        return err;
 }
+EXPORT_SYMBOL(netpoll_setup);
 
 static int __init netpoll_init(void)
 {
@@ -839,49 +894,65 @@ static int __init netpoll_init(void)
 }
 core_initcall(netpoll_init);
 
-void netpoll_cleanup(struct netpoll *np)
+void __netpoll_cleanup(struct netpoll *np)
 {
        struct netpoll_info *npinfo;
        unsigned long flags;
 
-       if (np->dev) {
-               npinfo = np->dev->npinfo;
-               if (npinfo) {
-                       if (!list_empty(&npinfo->rx_np)) {
-                               spin_lock_irqsave(&npinfo->rx_lock, flags);
-                               list_del(&np->rx);
-                               if (list_empty(&npinfo->rx_np))
-                                       npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
-                               spin_unlock_irqrestore(&npinfo->rx_lock, flags);
-                       }
+       npinfo = np->dev->npinfo;
+       if (!npinfo)
+               return;
 
-                       if (atomic_dec_and_test(&npinfo->refcnt)) {
-                               const struct net_device_ops *ops;
-                               skb_queue_purge(&npinfo->arp_tx);
-                               skb_queue_purge(&npinfo->txq);
-                               cancel_rearming_delayed_work(&npinfo->tx_work);
-
-                               /* clean after last, unfinished work */
-                               __skb_queue_purge(&npinfo->txq);
-                               kfree(npinfo);
-                               ops = np->dev->netdev_ops;
-                               if (ops->ndo_netpoll_cleanup)
-                                       ops->ndo_netpoll_cleanup(np->dev);
-                               else
-                                       np->dev->npinfo = NULL;
-                       }
-               }
+       if (!list_empty(&npinfo->rx_np)) {
+               spin_lock_irqsave(&npinfo->rx_lock, flags);
+               list_del(&np->rx);
+               if (list_empty(&npinfo->rx_np))
+                       npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
+               spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+       }
+
+       if (atomic_dec_and_test(&npinfo->refcnt)) {
+               const struct net_device_ops *ops;
+
+               ops = np->dev->netdev_ops;
+               if (ops->ndo_netpoll_cleanup)
+                       ops->ndo_netpoll_cleanup(np->dev);
+
+               rcu_assign_pointer(np->dev->npinfo, NULL);
 
-               dev_put(np->dev);
+               /* avoid racing with NAPI reading npinfo */
+               synchronize_rcu_bh();
+
+               skb_queue_purge(&npinfo->arp_tx);
+               skb_queue_purge(&npinfo->txq);
+               cancel_rearming_delayed_work(&npinfo->tx_work);
+
+               /* clean after last, unfinished work */
+               __skb_queue_purge(&npinfo->txq);
+               kfree(npinfo);
        }
+}
+EXPORT_SYMBOL_GPL(__netpoll_cleanup);
 
+void netpoll_cleanup(struct netpoll *np)
+{
+       if (!np->dev)
+               return;
+
+       rtnl_lock();
+       __netpoll_cleanup(np);
+       rtnl_unlock();
+
+       dev_put(np->dev);
        np->dev = NULL;
 }
+EXPORT_SYMBOL(netpoll_cleanup);
 
 int netpoll_trap(void)
 {
        return atomic_read(&trapped);
 }
+EXPORT_SYMBOL(netpoll_trap);
 
 void netpoll_set_trap(int trap)
 {
@@ -890,14 +961,4 @@ void netpoll_set_trap(int trap)
        else
                atomic_dec(&trapped);
 }
-
-EXPORT_SYMBOL(netpoll_send_skb);
 EXPORT_SYMBOL(netpoll_set_trap);
-EXPORT_SYMBOL(netpoll_trap);
-EXPORT_SYMBOL(netpoll_print_options);
-EXPORT_SYMBOL(netpoll_parse_options);
-EXPORT_SYMBOL(netpoll_setup);
-EXPORT_SYMBOL(netpoll_cleanup);
-EXPORT_SYMBOL(netpoll_send_udp);
-EXPORT_SYMBOL(netpoll_poll_dev);
-EXPORT_SYMBOL(netpoll_poll);