cfg80211: fix deadlock

[pandora-kernel.git] / net / wireless / core.c

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 755cdf1..69a185b 100644 (file)
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -32,11 +32,10 @@ MODULE_DESCRIPTION("wireless configuration support");
  * only read the list, and that can happen quite
  * often because we need to do it for each command */
 LIST_HEAD(cfg80211_rdev_list);
+int cfg80211_rdev_list_generation;
 
 /*
- * This is used to protect the cfg80211_rdev_list, cfg80211_regdomain,
- * country_ie_regdomain, the reg_beacon_list and the the last regulatory
- * request receipt (last_request).
+ * This is used to protect the cfg80211_rdev_list
  */
 DEFINE_MUTEX(cfg80211_mutex);
 
@@ -413,6 +412,8 @@ struct wiphy *wiphy_new(const struct cfg80211_ops *ops, int sizeof_priv)
        rdev->wiphy.dev.class = &ieee80211_class;
        rdev->wiphy.dev.platform_data = rdev;
 
+       rdev->wiphy.ps_default = CONFIG_CFG80211_DEFAULT_PS_VALUE;
+
        wiphy_net_set(&rdev->wiphy, &init_net);
 
        rdev->rfkill_ops.set_block = cfg80211_rfkill_set_block;
@@ -513,6 +514,7 @@ int wiphy_register(struct wiphy *wiphy)
        wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);
 
        list_add(&rdev->list, &cfg80211_rdev_list);
+       cfg80211_rdev_list_generation++;
 
        mutex_unlock(&cfg80211_mutex);
 
@@ -584,9 +586,14 @@ void wiphy_unregister(struct wiphy *wiphy)
         * get to lock contention here if userspace issues a command
         * that identified the hardware by wiphy index.
         */
-       mutex_lock(&rdev->mtx);
-       /* unlock again before freeing */
-       mutex_unlock(&rdev->mtx);
+       cfg80211_lock_rdev(rdev);
+
+       if (WARN_ON(rdev->scan_req)) {
+               rdev->scan_req->aborted = true;
+               ___cfg80211_scan_done(rdev);
+       }
+
+       cfg80211_unlock_rdev(rdev);
 
        cfg80211_debugfs_rdev_del(rdev);
 
@@ -595,14 +602,14 @@ void wiphy_unregister(struct wiphy *wiphy)
        reg_device_remove(wiphy);
 
        list_del(&rdev->list);
+       cfg80211_rdev_list_generation++;
        device_del(&rdev->wiphy.dev);
        debugfs_remove(rdev->wiphy.debugfsdir);
 
        mutex_unlock(&cfg80211_mutex);
 
+       flush_work(&rdev->scan_done_wk);
        cancel_work_sync(&rdev->conn_work);
-       cancel_work_sync(&rdev->scan_done_wk);
-       kfree(rdev->scan_req);
        flush_work(&rdev->event_work);
 }
 EXPORT_SYMBOL(wiphy_unregister);
@@ -650,11 +657,17 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
 
        switch (state) {
        case NETDEV_REGISTER:
+               /*
+                * NB: cannot take rdev->mtx here because this may be
+                * called within code protected by it when interfaces
+                * are added with nl80211.
+                */
                mutex_init(&wdev->mtx);
                INIT_LIST_HEAD(&wdev->event_list);
                spin_lock_init(&wdev->event_lock);
                mutex_lock(&rdev->devlist_mtx);
                list_add(&wdev->list, &rdev->netdev_list);
+               rdev->devlist_generation++;
                /* can only change netns with wiphy */
                dev->features |= NETIF_F_NETNS_LOCAL;
 
@@ -672,8 +685,8 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
                wdev->wext.default_key = -1;
                wdev->wext.default_mgmt_key = -1;
                wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC;
-               wdev->wext.ps = CONFIG_CFG80211_DEFAULT_PS_VALUE;
-               wdev->wext.ps_timeout = 500;
+               wdev->wext.ps = wdev->wiphy->ps_default;
+               wdev->wext.ps_timeout = 100;
                if (rdev->ops->set_power_mgmt)
                        if (rdev->ops->set_power_mgmt(wdev->wiphy, dev,
                                                      wdev->wext.ps,
@@ -708,6 +721,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
        case NETDEV_UP:
 #ifdef CONFIG_WIRELESS_EXT
                cfg80211_lock_rdev(rdev);
+               mutex_lock(&rdev->devlist_mtx);
                wdev_lock(wdev);
                switch (wdev->iftype) {
                case NL80211_IFTYPE_ADHOC:
@@ -720,20 +734,34 @@ static int cfg80211_netdev_notifier_call(struct notifier_block * nb,
                        break;
                }
                wdev_unlock(wdev);
+               mutex_unlock(&rdev->devlist_mtx);
                cfg80211_unlock_rdev(rdev);
 #endif
                break;
        case NETDEV_UNREGISTER:
+               /*
+                * NB: cannot take rdev->mtx here because this may be
+                * called within code protected by it when interfaces
+                * are removed with nl80211.
+                */
                mutex_lock(&rdev->devlist_mtx);
+               /*
+                * It is possible to get NETDEV_UNREGISTER
+                * multiple times. To detect that, check
+                * that the interface is still on the list
+                * of registered interfaces, and only then
+                * remove and clean it up.
+                */
                if (!list_empty(&wdev->list)) {
                        sysfs_remove_link(&dev->dev.kobj, "phy80211");
                        list_del_init(&wdev->list);
-               }
-               mutex_unlock(&rdev->devlist_mtx);
-               mutex_destroy(&wdev->mtx);
+                       rdev->devlist_generation++;
+                       mutex_destroy(&wdev->mtx);
 #ifdef CONFIG_WIRELESS_EXT
-               kfree(wdev->wext.keys);
+                       kfree(wdev->wext.keys);
 #endif
+               }
+               mutex_unlock(&rdev->devlist_mtx);
                break;
        case NETDEV_PRE_UP:
                if (!(wdev->wiphy->interface_modes & BIT(wdev->iftype)))