1 files changed, 26 insertions, 10 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 7914fdaf4226..64a395c7f689 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1354,7 +1354,8 @@ static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6
 	return skb->hash;
 }
 
-__u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb);
+__u32 skb_get_hash_perturb(const struct sk_buff *skb,
+			   const siphash_key_t *perturb);
 
 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
 {
@@ -1495,6 +1496,19 @@ static inline int skb_queue_empty(const struct sk_buff_head *list)
 }
 
 /**
+ *	skb_queue_empty_lockless - check if a queue is empty
+ *	@list: queue head
+ *
+ *	Returns true if the queue is empty, false otherwise.
+ *	This variant can be used in lockless contexts.
+ */
+static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
+{
+	return READ_ONCE(list->next) == (const struct sk_buff *) list;
+}
+
+
+/**
  *	skb_queue_is_last - check if skb is the last entry in the queue
  *	@list: queue head
  *	@skb: buffer
@@ -1847,9 +1861,11 @@ static inline void __skb_insert(struct sk_buff *newsk,
 				struct sk_buff *prev, struct sk_buff *next,
 				struct sk_buff_head *list)
 {
-	newsk->next = next;
-	newsk->prev = prev;
-	next->prev  = prev->next = newsk;
+	/* see skb_queue_empty_lockless() for the opposite READ_ONCE() */
+	WRITE_ONCE(newsk->next, next);
+	WRITE_ONCE(newsk->prev, prev);
+	WRITE_ONCE(next->prev, newsk);
+	WRITE_ONCE(prev->next, newsk);
 	list->qlen++;
 }
 
@@ -1860,11 +1876,11 @@ static inline void __skb_queue_splice(const struct sk_buff_head *list,
 	struct sk_buff *first = list->next;
 	struct sk_buff *last = list->prev;
 
-	first->prev = prev;
-	prev->next = first;
+	WRITE_ONCE(first->prev, prev);
+	WRITE_ONCE(prev->next, first);
 
-	last->next = next;
-	next->prev = last;
+	WRITE_ONCE(last->next, next);
+	WRITE_ONCE(next->prev, last);
 }
 
 /**
@@ -2005,8 +2021,8 @@ static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
 	next	   = skb->next;
 	prev	   = skb->prev;
 	skb->next  = skb->prev = NULL;
-	next->prev = prev;
-	prev->next = next;
+	WRITE_ONCE(next->prev, prev);
+	WRITE_ONCE(prev->next, next);
 }
 
 /**