Merge tag 'omap-for-v3.13/quirk-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/dt

From Tony Lindgren:
Changes needed to prepare for making omap3 device tree only:

- Always build in board-generic, and add pdata quirks and auxdata
  support for it so we have all the pdata related quirks
  in the same place.

- Merge of the drivers/pinctrl changes that are needed for PM
  to continue working on omap3 and also needed for other omaps
  eventually. The three pinctrl related patches have been acked
  by Linus Walleij and are pulled into both the pinctrl tree
  and this branch.

- Few defconfig related changes for drivers needed.

* tag 'omap-for-v3.13/quirk-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (523 commits)
  ARM: configs: omap2plus_defconfig: enable dwc3 and dependencies
  ARM: OMAP2+: Add WLAN modules and of_serial to omap2plus_defconfig
  ARM: OMAP2+: Run make savedefconfig on omap2plus_defconfig to shrink it
  ARM: OMAP2+: Add minimal 8250 support for GPMC
  ARM: OMAP2+: Use pdata quirks for wl12xx for omap3 evm and zoom3
  ARM: OMAP: Move DT wake-up event handling over to use pinctrl-single-omap
  ARM: OMAP2+: Add support for auxdata
  pinctrl: single: Add support for auxdata
  pinctrl: single: Add support for wake-up interrupts
  pinctrl: single: Prepare for supporting SoC specific features
  ARM: OMAP2+: igep0020: use display init from dss-common
  ARM: OMAP2+: pdata-quirks: add legacy display init for IGEPv2 board
  +Linux 3.12-rc4

Signed-off-by: Kevin Hilman <khilman@linaro.org>

1 files changed, 48 insertions, 1 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 5c713f2239cc..65f829cfd928 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5247,10 +5247,12 @@ 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)
@@ -5918,6 +5920,12 @@ 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);
         }
@@ -6603,6 +6611,34 @@ 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
@@ -6614,7 +6650,18 @@ 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)