1 files changed, 20 insertions, 6 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 32dafbab4cd0..bab01363bb97 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -240,9 +240,9 @@ static inline void dst_hold(struct dst_entry *dst)
 
 static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
 {
-	if (unlikely(time != dst->lastuse)) {
+	if (unlikely(time != READ_ONCE(dst->lastuse))) {
 		dst->__use++;
-		dst->lastuse = time;
+		WRITE_ONCE(dst->lastuse, time);
 	}
 }
 
@@ -431,13 +431,15 @@ static inline void dst_link_failure(struct sk_buff *skb)
 
 static inline void dst_set_expires(struct dst_entry *dst, int timeout)
 {
-	unsigned long expires = jiffies + timeout;
+	unsigned long old, expires = jiffies + timeout;
 
 	if (expires == 0)
 		expires = 1;
 
-	if (dst->expires == 0 || time_before(expires, dst->expires))
-		dst->expires = expires;
+	old = READ_ONCE(dst->expires);
+
+	if (!old || time_before(expires, old))
+		WRITE_ONCE(dst->expires, expires);
 }
 
 static inline unsigned int dst_dev_overhead(struct dst_entry *dst,
@@ -476,7 +478,7 @@ INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
 							   u32));
 static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
 {
-	if (dst->obsolete)
+	if (READ_ONCE(dst->obsolete))
 		dst = INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check,
 					 ipv4_dst_check, dst, cookie);
 	return dst;
@@ -566,11 +568,23 @@ static inline struct net_device *dst_dev(const struct dst_entry *dst)
 	return READ_ONCE(dst->dev);
 }
 
+static inline struct net_device *dst_dev_rcu(const struct dst_entry *dst)
+{
+	/* In the future, use rcu_dereference(dst->dev) */
+	WARN_ON_ONCE(!rcu_read_lock_held());
+	return READ_ONCE(dst->dev);
+}
+
 static inline struct net_device *skb_dst_dev(const struct sk_buff *skb)
 {
 	return dst_dev(skb_dst(skb));
 }
 
+static inline struct net_device *skb_dst_dev_rcu(const struct sk_buff *skb)
+{
+	return dst_dev_rcu(skb_dst(skb));
+}
+
 static inline struct net *skb_dst_dev_net(const struct sk_buff *skb)
 {
 	return dev_net(skb_dst_dev(skb));