Merge tag 'hte/for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux

[linux-2.6-microblaze.git] / net / core / dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index 8e6f229..30a1603 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4863,7 +4863,10 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
 }
 
 /* When doing generic XDP we have to bypass the qdisc layer and the
- * network taps in order to match in-driver-XDP behavior.
+ * network taps in order to match in-driver-XDP behavior. This also means
+ * that XDP packets are able to starve other packets going through a qdisc,
+ * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
+ * queues, so they do not have this starvation issue.
  */
 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
 {
@@ -4875,7 +4878,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
        txq = netdev_core_pick_tx(dev, skb, NULL);
        cpu = smp_processor_id();
        HARD_TX_LOCK(dev, txq, cpu);
-       if (!netif_xmit_stopped(txq)) {
+       if (!netif_xmit_frozen_or_drv_stopped(txq)) {
                rc = netdev_start_xmit(skb, dev, txq, 0);
                if (dev_xmit_complete(rc))
                        free_skb = false;
@@ -4883,6 +4886,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
        HARD_TX_UNLOCK(dev, txq);
        if (free_skb) {
                trace_xdp_exception(dev, xdp_prog, XDP_TX);
+               dev_core_stats_tx_dropped_inc(dev);
                kfree_skb(skb);
        }
 }