cfg80211: fix sysfs registration race

My locking rework/race fixes caused a regression in the
registration, causing uevent notifications for wireless
devices before the device is really fully registered and
available in nl80211.

Fix this by moving the device_add() under rtnl and move
the rfkill to afterwards (it can't be under rtnl.)

Reported-and-tested-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 6715396..fe8d4f2 100644 (file)
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -566,18 +566,13 @@ int wiphy_register(struct wiphy *wiphy)
        /* check and set up bitrates */
        ieee80211_set_bitrate_flags(wiphy);
 
-
+       rtnl_lock();
        res = device_add(&rdev->wiphy.dev);
-       if (res)
-               return res;
-
-       res = rfkill_register(rdev->rfkill);
        if (res) {
-               device_del(&rdev->wiphy.dev);
+               rtnl_unlock();
                return res;
        }
 
-       rtnl_lock();
        /* set up regulatory info */
        wiphy_regulatory_register(wiphy);
 
@@ -606,6 +601,15 @@ int wiphy_register(struct wiphy *wiphy)
 
        rdev->wiphy.registered = true;
        rtnl_unlock();
+
+       res = rfkill_register(rdev->rfkill);
+       if (res) {
+               rfkill_destroy(rdev->rfkill);
+               rdev->rfkill = NULL;
+               wiphy_unregister(&rdev->wiphy);
+               return res;
+       }
+
        return 0;
 }
 EXPORT_SYMBOL(wiphy_register);
@@ -640,7 +644,8 @@ void wiphy_unregister(struct wiphy *wiphy)
                rtnl_unlock();
                __count == 0; }));
 
-       rfkill_unregister(rdev->rfkill);
+       if (rdev->rfkill)
+               rfkill_unregister(rdev->rfkill);
 
        rtnl_lock();
        rdev->wiphy.registered = false;