3 files changed, 46 insertions, 3 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index e1bb6d7856d9..4d4de9008f6f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4516,12 +4516,13 @@ set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
 	    struct rps_dev_flow *rflow, u16 next_cpu)
 {
 	if (next_cpu < nr_cpu_ids) {
+		u32 head;
 #ifdef CONFIG_RFS_ACCEL
 		struct netdev_rx_queue *rxqueue;
 		struct rps_dev_flow_table *flow_table;
 		struct rps_dev_flow *old_rflow;
-		u32 flow_id, head;
 		u16 rxq_index;
+		u32 flow_id;
 		int rc;
 
 		/* Should we steer this flow to a different hardware queue? */
diff --git a/net/core/dst_cache.c b/net/core/dst_cache.c
index 6a0482e676d3..70c634b9e7b0 100644
--- a/net/core/dst_cache.c
+++ b/net/core/dst_cache.c
@@ -27,6 +27,7 @@ struct dst_cache_pcpu {
 static void dst_cache_per_cpu_dst_set(struct dst_cache_pcpu *dst_cache,
 				      struct dst_entry *dst, u32 cookie)
 {
+	DEBUG_NET_WARN_ON_ONCE(!in_softirq());
 	dst_release(dst_cache->dst);
 	if (dst)
 		dst_hold(dst);
@@ -40,6 +41,7 @@ static struct dst_entry *dst_cache_per_cpu_get(struct dst_cache *dst_cache,
 {
 	struct dst_entry *dst;
 
+	DEBUG_NET_WARN_ON_ONCE(!in_softirq());
 	dst = idst->dst;
 	if (!dst)
 		goto fail;
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index b86b0a87367d..4668d6718040 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -6484,6 +6484,46 @@ static int rtnl_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 /* Process one rtnetlink message. */
 
+static int rtnl_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	rtnl_dumpit_func dumpit = cb->data;
+	int err;
+
+	/* Previous iteration have already finished, avoid calling->dumpit()
+	 * again, it may not expect to be called after it reached the end.
+	 */
+	if (!dumpit)
+		return 0;
+
+	err = dumpit(skb, cb);
+
+	/* Old dump handlers used to send NLM_DONE as in a separate recvmsg().
+	 * Some applications which parse netlink manually depend on this.
+	 */
+	if (cb->flags & RTNL_FLAG_DUMP_SPLIT_NLM_DONE) {
+		if (err < 0 && err != -EMSGSIZE)
+			return err;
+		if (!err)
+			cb->data = NULL;
+
+		return skb->len;
+	}
+	return err;
+}
+
+static int rtnetlink_dump_start(struct sock *ssk, struct sk_buff *skb,
+				const struct nlmsghdr *nlh,
+				struct netlink_dump_control *control)
+{
+	if (control->flags & RTNL_FLAG_DUMP_SPLIT_NLM_DONE) {
+		WARN_ON(control->data);
+		control->data = control->dump;
+		control->dump = rtnl_dumpit;
+	}
+
+	return netlink_dump_start(ssk, skb, nlh, control);
+}
+
 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 			     struct netlink_ext_ack *extack)
 {
@@ -6548,7 +6588,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 				.module		= owner,
 				.flags		= flags,
 			};
-			err = netlink_dump_start(rtnl, skb, nlh, &c);
+			err = rtnetlink_dump_start(rtnl, skb, nlh, &c);
 			/* netlink_dump_start() will keep a reference on
 			 * module if dump is still in progress.
 			 */
@@ -6694,7 +6734,7 @@ void __init rtnetlink_init(void)
 	register_netdevice_notifier(&rtnetlink_dev_notifier);
 
 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink,
-		      rtnl_dump_ifinfo, 0);
+		      rtnl_dump_ifinfo, RTNL_FLAG_DUMP_SPLIT_NLM_DONE);
 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, 0);