1 files changed, 45 insertions, 11 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 2512f672bf8a..c253c2aafe97 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -148,6 +148,7 @@
 #include <net/devlink.h>
 #include <linux/pm_runtime.h>
 #include <linux/prandom.h>
+#include <linux/once_lite.h>
 
 #include "net-sysfs.h"
 
@@ -3487,13 +3488,16 @@ EXPORT_SYMBOL(__skb_gso_segment);
 
 /* Take action when hardware reception checksum errors are detected. */
 #ifdef CONFIG_BUG
+static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
+{
+	pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
+	skb_dump(KERN_ERR, skb, true);
+	dump_stack();
+}
+
 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
 {
-	if (net_ratelimit()) {
-		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
-		skb_dump(KERN_ERR, skb, true);
-		dump_stack();
-	}
+	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
 }
 EXPORT_SYMBOL(netdev_rx_csum_fault);
 #endif
@@ -3852,10 +3856,33 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
 	qdisc_calculate_pkt_len(skb, q);
 
 	if (q->flags & TCQ_F_NOLOCK) {
+		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
+		    qdisc_run_begin(q)) {
+			/* Retest nolock_qdisc_is_empty() within the protection
+			 * of q->seqlock to protect from racing with requeuing.
+			 */
+			if (unlikely(!nolock_qdisc_is_empty(q))) {
+				rc = q->enqueue(skb, q, &to_free) &
+					NET_XMIT_MASK;
+				__qdisc_run(q);
+				qdisc_run_end(q);
+
+				goto no_lock_out;
+			}
+
+			qdisc_bstats_cpu_update(q, skb);
+			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
+			    !nolock_qdisc_is_empty(q))
+				__qdisc_run(q);
+
+			qdisc_run_end(q);
+			return NET_XMIT_SUCCESS;
+		}
+
 		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
-		if (likely(!netif_xmit_frozen_or_stopped(txq)))
-			qdisc_run(q);
+		qdisc_run(q);
 
+no_lock_out:
 		if (unlikely(to_free))
 			kfree_skb_list(to_free);
 		return rc;
@@ -5277,9 +5304,9 @@ another_round:
 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
 		int ret2;
 
-		preempt_disable();
+		migrate_disable();
 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
-		preempt_enable();
+		migrate_enable();
 
 		if (ret2 != XDP_PASS) {
 			ret = NET_RX_DROP;
@@ -6520,11 +6547,18 @@ EXPORT_SYMBOL(napi_schedule_prep);
  * __napi_schedule_irqoff - schedule for receive
  * @n: entry to schedule
  *
- * Variant of __napi_schedule() assuming hard irqs are masked
+ * Variant of __napi_schedule() assuming hard irqs are masked.
+ *
+ * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
+ * because the interrupt disabled assumption might not be true
+ * due to force-threaded interrupts and spinlock substitution.
  */
 void __napi_schedule_irqoff(struct napi_struct *n)
 {
-	____napi_schedule(this_cpu_ptr(&softnet_data), n);
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		____napi_schedule(this_cpu_ptr(&softnet_data), n);
+	else
+		__napi_schedule(n);
 }
 EXPORT_SYMBOL(__napi_schedule_irqoff);