1 files changed, 39 insertions, 3 deletions

diff --git a/include/linux/list.h b/include/linux/list.h
index dd6c2041d09c..61762054b4be 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -35,7 +35,7 @@
 static inline void INIT_LIST_HEAD(struct list_head *list)
 {
 	WRITE_ONCE(list->next, list);
-	list->prev = list;
+	WRITE_ONCE(list->prev, list);
 }
 
 #ifdef CONFIG_DEBUG_LIST
@@ -306,7 +306,7 @@ static inline int list_empty(const struct list_head *head)
 static inline void list_del_init_careful(struct list_head *entry)
 {
 	__list_del_entry(entry);
-	entry->prev = entry;
+	WRITE_ONCE(entry->prev, entry);
 	smp_store_release(&entry->next, entry);
 }
 
@@ -326,7 +326,7 @@ static inline void list_del_init_careful(struct list_head *entry)
 static inline int list_empty_careful(const struct list_head *head)
 {
 	struct list_head *next = smp_load_acquire(&head->next);
-	return list_is_head(next, head) && (next == head->prev);
+	return list_is_head(next, head) && (next == READ_ONCE(head->prev));
 }
 
 /**
@@ -564,6 +564,19 @@ static inline void list_splice_tail_init(struct list_head *list,
 	list_entry((pos)->member.next, typeof(*(pos)), member)
 
 /**
+ * list_next_entry_circular - get the next element in list
+ * @pos:	the type * to cursor.
+ * @head:	the list head to take the element from.
+ * @member:	the name of the list_head within the struct.
+ *
+ * Wraparound if pos is the last element (return the first element).
+ * Note, that list is expected to be not empty.
+ */
+#define list_next_entry_circular(pos, head, member) \
+	(list_is_last(&(pos)->member, head) ? \
+	list_first_entry(head, typeof(*(pos)), member) : list_next_entry(pos, member))
+
+/**
  * list_prev_entry - get the prev element in list
  * @pos:	the type * to cursor
  * @member:	the name of the list_head within the struct.
@@ -572,6 +585,19 @@ static inline void list_splice_tail_init(struct list_head *list,
 	list_entry((pos)->member.prev, typeof(*(pos)), member)
 
 /**
+ * list_prev_entry_circular - get the prev element in list
+ * @pos:	the type * to cursor.
+ * @head:	the list head to take the element from.
+ * @member:	the name of the list_head within the struct.
+ *
+ * Wraparound if pos is the first element (return the last element).
+ * Note, that list is expected to be not empty.
+ */
+#define list_prev_entry_circular(pos, head, member) \
+	(list_is_first(&(pos)->member, head) ? \
+	list_last_entry(head, typeof(*(pos)), member) : list_prev_entry(pos, member))
+
+/**
  * list_for_each	-	iterate over a list
  * @pos:	the &struct list_head to use as a loop cursor.
  * @head:	the head for your list.
@@ -580,6 +606,16 @@ static inline void list_splice_tail_init(struct list_head *list,
 	for (pos = (head)->next; !list_is_head(pos, (head)); pos = pos->next)
 
 /**
+ * list_for_each_rcu - Iterate over a list in an RCU-safe fashion
+ * @pos:	the &struct list_head to use as a loop cursor.
+ * @head:	the head for your list.
+ */
+#define list_for_each_rcu(pos, head)		  \
+	for (pos = rcu_dereference((head)->next); \
+	     !list_is_head(pos, (head)); \
+	     pos = rcu_dereference(pos->next))
+
+/**
  * list_for_each_continue - continue iteration over a list
  * @pos:	the &struct list_head to use as a loop cursor.
  * @head:	the head for your list.