Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 36 insertions, 10 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index f36bd3b21997..ae37586f6ee8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5058,11 +5058,12 @@ static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
 	return 0;
 }
 
-static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc,
+static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
 				    struct packet_type **ppt_prev)
 {
 	struct packet_type *ptype, *pt_prev;
 	rx_handler_func_t *rx_handler;
+	struct sk_buff *skb = *pskb;
 	struct net_device *orig_dev;
 	bool deliver_exact = false;
 	int ret = NET_RX_DROP;
@@ -5093,8 +5094,10 @@ another_round:
 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
 		preempt_enable();
 
-		if (ret2 != XDP_PASS)
-			return NET_RX_DROP;
+		if (ret2 != XDP_PASS) {
+			ret = NET_RX_DROP;
+			goto out;
+		}
 		skb_reset_mac_len(skb);
 	}
 
@@ -5244,6 +5247,13 @@ drop:
 	}
 
 out:
+	/* The invariant here is that if *ppt_prev is not NULL
+	 * then skb should also be non-NULL.
+	 *
+	 * Apparently *ppt_prev assignment above holds this invariant due to
+	 * skb dereferencing near it.
+	 */
+	*pskb = skb;
 	return ret;
 }
 
@@ -5253,7 +5263,7 @@ static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
 	struct packet_type *pt_prev = NULL;
 	int ret;
 
-	ret = __netif_receive_skb_core(skb, pfmemalloc, &pt_prev);
+	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
 	if (pt_prev)
 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
 					 skb->dev, pt_prev, orig_dev);
@@ -5331,7 +5341,7 @@ static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemallo
 		struct packet_type *pt_prev = NULL;
 
 		skb_list_del_init(skb);
-		__netif_receive_skb_core(skb, pfmemalloc, &pt_prev);
+		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
 		if (!pt_prev)
 			continue;
 		if (pt_curr != pt_prev || od_curr != orig_dev) {
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 3eff84824c8b..5dceed467f64 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -160,12 +160,10 @@ out:
 	return ret;
 }
 
-int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
+static int flow_dissector_bpf_prog_detach(struct net *net)
 {
 	struct bpf_prog *attached;
-	struct net *net;
 
-	net = current->nsproxy->net_ns;
 	mutex_lock(&flow_dissector_mutex);
 	attached = rcu_dereference_protected(net->flow_dissector_prog,
 					     lockdep_is_held(&flow_dissector_mutex));
@@ -179,6 +177,24 @@ int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
 	return 0;
 }
 
+int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
+{
+	return flow_dissector_bpf_prog_detach(current->nsproxy->net_ns);
+}
+
+static void __net_exit flow_dissector_pernet_pre_exit(struct net *net)
+{
+	/* We're not racing with attach/detach because there are no
+	 * references to netns left when pre_exit gets called.
+	 */
+	if (rcu_access_pointer(net->flow_dissector_prog))
+		flow_dissector_bpf_prog_detach(net);
+}
+
+static struct pernet_operations flow_dissector_pernet_ops __net_initdata = {
+	.pre_exit = flow_dissector_pernet_pre_exit,
+};
+
 /**
  * __skb_flow_get_ports - extract the upper layer ports and return them
  * @skb: sk_buff to extract the ports from
@@ -1836,7 +1852,7 @@ static int __init init_default_flow_dissectors(void)
 	skb_flow_dissector_init(&flow_keys_basic_dissector,
 				flow_keys_basic_dissector_keys,
 				ARRAY_SIZE(flow_keys_basic_dissector_keys));
-	return 0;
-}
 
+	return register_pernet_subsys(&flow_dissector_pernet_ops);
+}
 core_initcall(init_default_flow_dissectors);