cfg80211: allow reprocessing of pending requests

In certain situations we want to trigger reprocessing
of the last regulatory hint. One situation in which
this makes sense is the case where the cfg80211 was
built-in to the kernel, CFG80211_INTERNAL_REGDB was not
enabled and the CRDA binary is on a partition not availble
during early boot. In such a case we want to be able to
re-process the same request at some other point.

When we are asked to re-process the same request we need
to be careful to not kfree it, addresses that.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
[rename function]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/reg.c

@@ -240,19 +240,21 @@ static char user_alpha2[2];
 module_param(ieee80211_regdom, charp, 0444);
 MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");
 
-static void reg_kfree_last_request(void)
+static void reg_free_request(struct regulatory_request *lr)
 {
-	struct regulatory_request *lr;
-
-	lr = get_last_request();
-
 	if (lr != &core_request_world && lr)
 		kfree_rcu(lr, rcu_head);
 }
 
 static void reg_update_last_request(struct regulatory_request *request)
 {
-	reg_kfree_last_request();
+	struct regulatory_request *lr;
+
+	lr = get_last_request();
+	if (lr == request)
+		return;
+
+	reg_free_request(lr);
 	rcu_assign_pointer(last_request, request);
 }