Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Conflicts:
	drivers/net/ethernet/emulex/benet/be.h
	drivers/net/usb/qmi_wwan.c
	drivers/net/wireless/brcm80211/brcmfmac/dhd_bus.h
	include/net/netfilter/nf_conntrack_synproxy.h
	include/net/secure_seq.h

The conflicts are of two varieties:

1) Conflicts with Joe Perches's 'extern' removal from header file
   function declarations.  Usually it's an argument signature change
   or a function being added/removed.  The resolutions are trivial.

2) Some overlapping changes in qmi_wwan.c and be.h, one commit adds
   a new value, another changes an existing value.  That sort of
   thing.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 48 insertions, 1 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 81340ed7f0f4..c25db20a4246 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5428,10 +5428,12 @@ static int dev_new_index(struct net *net)
 
 /* Delayed registration/unregisteration */
 static LIST_HEAD(net_todo_list);
+static DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
 
 static void net_set_todo(struct net_device *dev)
 {
         list_add_tail(&dev->todo_list, &net_todo_list);
+        dev_net(dev)->dev_unreg_count++;
 }
 
 static void rollback_registered_many(struct list_head *head)
@@ -6099,6 +6101,12 @@ void netdev_run_todo(void)
                 if (dev->destructor)
                         dev->destructor(dev);
 
+                /* Report a network device has been unregistered */
+                rtnl_lock();
+                dev_net(dev)->dev_unreg_count--;
+                __rtnl_unlock();
+                wake_up(&netdev_unregistering_wq);
+
                 /* Free network device */
                 kobject_put(&dev->dev.kobj);
         }
@@ -6786,6 +6794,34 @@ static void __net_exit default_device_exit(struct net *net)
         rtnl_unlock();
 }
 
+static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
+{
+        /* Return with the rtnl_lock held when there are no network
+         * devices unregistering in any network namespace in net_list.
+         */
+        struct net *net;
+        bool unregistering;
+        DEFINE_WAIT(wait);
+
+        for (;;) {
+                prepare_to_wait(&netdev_unregistering_wq, &wait,
+                                TASK_UNINTERRUPTIBLE);
+                unregistering = false;
+                rtnl_lock();
+                list_for_each_entry(net, net_list, exit_list) {
+                        if (net->dev_unreg_count > 0) {
+                                unregistering = true;
+                                break;
+                        }
+                }
+                if (!unregistering)
+                        break;
+                __rtnl_unlock();
+                schedule();
+        }
+        finish_wait(&netdev_unregistering_wq, &wait);
+}
+
 static void __net_exit default_device_exit_batch(struct list_head *net_list)
 {
         /* At exit all network devices most be removed from a network
@@ -6797,7 +6833,18 @@ static void __net_exit default_device_exit_batch(struct list_head *net_list)
         struct net *net;
         LIST_HEAD(dev_kill_list);
 
-        rtnl_lock();
+        /* To prevent network device cleanup code from dereferencing
+         * loopback devices or network devices that have been freed
+         * wait here for all pending unregistrations to complete,
+         * before unregistring the loopback device and allowing the
+         * network namespace be freed.
+         *
+         * The netdev todo list containing all network devices
+         * unregistrations that happen in default_device_exit_batch
+         * will run in the rtnl_unlock() at the end of
+         * default_device_exit_batch.
+         */
+        rtnl_lock_unregistering(net_list);
         list_for_each_entry(net, net_list, exit_list) {
                 for_each_netdev_reverse(net, dev) {
                         if (dev->rtnl_link_ops)