net: fix skb leak in __skb_tstamp_tx()

[platform/kernel/linux-starfive.git] / net / core / netpoll.c

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 9be762e..4ac8d0a 100644 (file)
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -137,6 +137,20 @@ static void queue_process(struct work_struct *work)
        }
 }
 
+static int netif_local_xmit_active(struct net_device *dev)
+{
+       int i;
+
+       for (i = 0; i < dev->num_tx_queues; i++) {
+               struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+
+               if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id())
+                       return 1;
+       }
+
+       return 0;
+}
+
 static void poll_one_napi(struct napi_struct *napi)
 {
        int work;
@@ -183,7 +197,10 @@ void netpoll_poll_dev(struct net_device *dev)
        if (!ni || down_trylock(&ni->dev_lock))
                return;
 
-       if (!netif_running(dev)) {
+       /* Some drivers will take the same locks in poll and xmit,
+        * we can't poll if local CPU is already in xmit.
+        */
+       if (!netif_running(dev) || netif_local_xmit_active(dev)) {
                up(&ni->dev_lock);
                return;
        }