d80211: make _irqsafe functions understandable

@@ -3885,16 +3885,27 @@ void ieee80211_rx_irqsafe(struct net_dev
 			  struct ieee80211_rx_status *status)
 {
 	struct ieee80211_local *local = dev->ieee80211_ptr;
-	struct ieee80211_rx_status *saved;
+	struct ieee80211_rx_status *saved, *tmp;
 
-        skb->dev = dev;
+	skb->dev = dev;
 	saved = kmalloc(sizeof(struct ieee80211_rx_status), GFP_ATOMIC);
-	if (saved)
-		memcpy(saved, status, sizeof(struct ieee80211_rx_status));
+	if (unlikely(!saved)) {
+		if (net_ratelimit())
+			printk(KERN_WARNING "%s: Not enough memory, "
+			       "dropping packet", skb->dev->name);
+		/* should be dev_kfree_skb_irq, but due to this function being
+		 * named _irqsafe instead of just _irq we can't be sure that
+		 * people won't call it from non-irq contexts */
+		dev_kfree_skb_any(skb);
+		return;
+	}
+	memcpy(saved, status, sizeof(struct ieee80211_rx_status));
+	/* copy pointer to saved status into skb->cb for use by tasklet */
 	memcpy(skb->cb, &saved, sizeof(saved));
-        skb->pkt_type = ieee80211_rx_msg;
-        skb_queue_tail(&local->skb_queue, skb);
-        tasklet_schedule(&local->tasklet);
+
+	skb->pkt_type = ieee80211_rx_msg;
+	skb_queue_tail(&local->skb_queue, skb);
+	tasklet_schedule(&local->tasklet);
 }
 EXPORT_SYMBOL(ieee80211_rx_irqsafe);
 

@@ -3905,12 +3916,23 @@ void ieee80211_tx_status_irqsafe(struct 
 	struct ieee80211_tx_status *saved;
 	int tmp;
 
-        skb->dev = dev;
+	skb->dev = dev;
 	saved = kmalloc(sizeof(struct ieee80211_tx_status), GFP_ATOMIC);
-	if (saved)
-		memcpy(saved, status, sizeof(struct ieee80211_tx_status));
+	if (unlikely(!saved)) {
+		if (net_ratelimit())
+			printk(KERN_WARNING "%s: Not enough memory, "
+			       "dropping tx status", skb->dev->name);
+		/* should be dev_kfree_skb_irq, but due to this function being
+		 * named _irqsafe instead of just _irq we can't be sure that
+		 * people won't call it from non-irq contexts */
+		dev_kfree_skb_any(skb);
+		return;
+	}
+	memcpy(saved, status, sizeof(struct ieee80211_tx_status));
+	/* copy pointer to saved status into skb->cb for use by tasklet */
 	memcpy(skb->cb, &saved, sizeof(saved));
-        skb->pkt_type = ieee80211_tx_status_msg;
+
+	skb->pkt_type = ieee80211_tx_status_msg;
 	skb_queue_tail(status->control.req_tx_status ?
 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
 	tmp = skb_queue_len(&local->skb_queue) +

@@ -3938,15 +3960,8 @@ static void ieee80211_tasklet_handler(un
 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
                 switch (skb->pkt_type) {
 		case ieee80211_rx_msg:
+			/* get pointer to saved status out of skb->cb */
 			memcpy(&rx_status, skb->cb, sizeof(rx_status));
-			if (!rx_status) {
-				if (net_ratelimit())
-					printk(KERN_WARNING "%s: Not enough "
-					       "memory, dropping packet",
-					       skb->dev->name);
-				dev_kfree_skb(skb);
-				return;
-			}
 			/* Clear skb->type in order to not confuse kernel
 			 * netstack. */
 			skb->pkt_type = 0;

@@ -3954,11 +3969,8 @@ static void ieee80211_tasklet_handler(un
 			kfree(rx_status);
 			break;
 		case ieee80211_tx_status_msg:
+			/* get pointer to saved status out of skb->cb */
 			memcpy(&tx_status, skb->cb, sizeof(tx_status));
-			if (!tx_status) {
-				dev_kfree_skb(skb);
-				return;
-			}
 			skb->pkt_type = 0;
 			ieee80211_tx_status(skb->dev, skb, tx_status);
 			kfree(tx_status);