Fix: handle sys_futex() FUTEX_WAIT interrupted by signal

[urcu.git] / urcu / rcuhlist.h

diff --git a/urcu/rcuhlist.h b/urcu/rcuhlist.h
index 36da15bc31d95394420a6958c05a5435927b1c2b..69c4d3184fd50d7f38a730e17447678f5fec3991 100644 (file)
--- a/urcu/rcuhlist.h
+++ b/urcu/rcuhlist.h
@@ -36,10 +36,9 @@ void cds_hlist_add_head_rcu(struct cds_hlist_node *newp,
 {
        newp->next = head->next;
        newp->prev = (struct cds_hlist_node *)head;
-       cmm_smp_wmb();
        if (head->next)
                head->next->prev = newp;
-       head->next = newp;
+       rcu_assign_pointer(head->next, newp);
 }
 
 /* Remove element from list. */
@@ -48,13 +47,23 @@ void cds_hlist_del_rcu(struct cds_hlist_node *elem)
 {
        if (elem->next)
                elem->next->prev = elem->prev;
-       elem->prev->next = elem->next;
+       CMM_STORE_SHARED(elem->prev->next, elem->next);
 }
 
 /*
  * Iterate through elements of the list.
  * This must be done while rcu_read_lock() is held.
  */
+#define cds_hlist_for_each_rcu(pos, head) \
+       for (pos = rcu_dereference((head)->next); pos != NULL; \
+               pos = rcu_dereference(pos->next))
+
+/*
+ * cds_hlist_for_each_entry_rcu takes 4 arguments, while the Linux
+ * kernel API only takes 3.
+ * We implement cds_hlist_for_each_entry_rcu_2() to follow the Linux
+ * kernel APIs.
+ */
 #define cds_hlist_for_each_entry_rcu(entry, pos, head, member) \
        for (pos = rcu_dereference((head)->next), \
                        entry = cds_hlist_entry(pos, __typeof__(*entry), member); \
@@ -62,4 +71,11 @@ void cds_hlist_del_rcu(struct cds_hlist_node *elem)
                pos = rcu_dereference(pos->next), \
                        entry = cds_hlist_entry(pos, __typeof__(*entry), member))
 
+#define cds_hlist_for_each_entry_rcu_2(entry, head, member) \
+       for (entry = cds_hlist_entry(rcu_dereference((head)->next), \
+                       __typeof__(*entry), member); \
+               &entry->member != NULL; \
+               entry = cds_hlist_entry(rcu_dereference(entry->member.next), \
+                       __typeof__(*entry), member))
+
 #endif /* _URCU_RCUHLIST_H */