diff options
Diffstat (limited to 'include/linux/rculist.h')
| -rw-r--r-- | include/linux/rculist.h | 70 |
1 files changed, 51 insertions, 19 deletions
diff --git a/include/linux/rculist.h b/include/linux/rculist.h index e91ec9ddcd30..9f313e4999fe 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -40,6 +40,34 @@ static inline void INIT_LIST_HEAD_RCU(struct list_head *list) */ #define list_next_rcu(list) (*((struct list_head __rcu **)(&(list)->next))) +/** + * list_tail_rcu - returns the prev pointer of the head of the list + * @head: the head of the list + * + * Note: This should only be used with the list header, and even then + * only if list_del() and similar primitives are not also used on the + * list header. + */ +#define list_tail_rcu(head) (*((struct list_head __rcu **)(&(head)->prev))) + +/* + * Check during list traversal that we are within an RCU reader + */ + +#define check_arg_count_one(dummy) + +#ifdef CONFIG_PROVE_RCU_LIST +#define __list_check_rcu(dummy, cond, extra...) \ + ({ \ + check_arg_count_one(extra); \ + RCU_LOCKDEP_WARN(!cond && !rcu_read_lock_any_held(), \ + "RCU-list traversed in non-reader section!"); \ + }) +#else +#define __list_check_rcu(dummy, cond, extra...) \ + ({ check_arg_count_one(extra); }) +#endif + /* * Insert a new entry between two known consecutive entries. * @@ -155,7 +183,7 @@ static inline void hlist_del_init_rcu(struct hlist_node *n) { if (!hlist_unhashed(n)) { __hlist_del(n); - n->pprev = NULL; + WRITE_ONCE(n->pprev, NULL); } } @@ -343,14 +371,16 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, * @pos: the type * to use as a loop cursor. * @head: the head for your list. * @member: the name of the list_head within the struct. + * @cond...: optional lockdep expression if called from non-RCU protection. * * This list-traversal primitive may safely run concurrently with * the _rcu list-mutation primitives such as list_add_rcu() * as long as the traversal is guarded by rcu_read_lock(). */ -#define list_for_each_entry_rcu(pos, head, member) \ - for (pos = list_entry_rcu((head)->next, typeof(*pos), member); \ - &pos->member != (head); \ +#define list_for_each_entry_rcu(pos, head, member, cond...) \ + for (__list_check_rcu(dummy, ## cond, 0), \ + pos = list_entry_rcu((head)->next, typeof(*pos), member); \ + &pos->member != (head); \ pos = list_entry_rcu(pos->member.next, typeof(*pos), member)) /** @@ -453,7 +483,7 @@ static inline void list_splice_tail_init_rcu(struct list_head *list, static inline void hlist_del_rcu(struct hlist_node *n) { __hlist_del(n); - n->pprev = LIST_POISON2; + WRITE_ONCE(n->pprev, LIST_POISON2); } /** @@ -469,11 +499,11 @@ static inline void hlist_replace_rcu(struct hlist_node *old, struct hlist_node *next = old->next; new->next = next; - new->pprev = old->pprev; + WRITE_ONCE(new->pprev, old->pprev); rcu_assign_pointer(*(struct hlist_node __rcu **)new->pprev, new); if (next) - new->next->pprev = &new->next; - old->pprev = LIST_POISON2; + WRITE_ONCE(new->next->pprev, &new->next); + WRITE_ONCE(old->pprev, LIST_POISON2); } /* @@ -508,10 +538,10 @@ static inline void hlist_add_head_rcu(struct hlist_node *n, struct hlist_node *first = h->first; n->next = first; - n->pprev = &h->first; + WRITE_ONCE(n->pprev, &h->first); rcu_assign_pointer(hlist_first_rcu(h), n); if (first) - first->pprev = &n->next; + WRITE_ONCE(first->pprev, &n->next); } /** @@ -544,7 +574,7 @@ static inline void hlist_add_tail_rcu(struct hlist_node *n, if (last) { n->next = last->next; - n->pprev = &last->next; + WRITE_ONCE(n->pprev, &last->next); rcu_assign_pointer(hlist_next_rcu(last), n); } else { hlist_add_head_rcu(n, h); @@ -572,10 +602,10 @@ static inline void hlist_add_tail_rcu(struct hlist_node *n, static inline void hlist_add_before_rcu(struct hlist_node *n, struct hlist_node *next) { - n->pprev = next->pprev; + WRITE_ONCE(n->pprev, next->pprev); n->next = next; rcu_assign_pointer(hlist_pprev_rcu(n), n); - next->pprev = &n->next; + WRITE_ONCE(next->pprev, &n->next); } /** @@ -600,10 +630,10 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n, struct hlist_node *prev) { n->next = prev->next; - n->pprev = &prev->next; + WRITE_ONCE(n->pprev, &prev->next); rcu_assign_pointer(hlist_next_rcu(prev), n); if (n->next) - n->next->pprev = &n->next; + WRITE_ONCE(n->next->pprev, &n->next); } #define __hlist_for_each_rcu(pos, head) \ @@ -616,13 +646,15 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n, * @pos: the type * to use as a loop cursor. * @head: the head for your list. * @member: the name of the hlist_node within the struct. + * @cond...: optional lockdep expression if called from non-RCU protection. * * This list-traversal primitive may safely run concurrently with * the _rcu list-mutation primitives such as hlist_add_head_rcu() * as long as the traversal is guarded by rcu_read_lock(). */ -#define hlist_for_each_entry_rcu(pos, head, member) \ - for (pos = hlist_entry_safe (rcu_dereference_raw(hlist_first_rcu(head)),\ +#define hlist_for_each_entry_rcu(pos, head, member, cond...) \ + for (__list_check_rcu(dummy, ## cond, 0), \ + pos = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),\ typeof(*(pos)), member); \ pos; \ pos = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(\ @@ -642,10 +674,10 @@ static inline void hlist_add_behind_rcu(struct hlist_node *n, * not do any RCU debugging or tracing. */ #define hlist_for_each_entry_rcu_notrace(pos, head, member) \ - for (pos = hlist_entry_safe (rcu_dereference_raw_notrace(hlist_first_rcu(head)),\ + for (pos = hlist_entry_safe(rcu_dereference_raw_check(hlist_first_rcu(head)),\ typeof(*(pos)), member); \ pos; \ - pos = hlist_entry_safe(rcu_dereference_raw_notrace(hlist_next_rcu(\ + pos = hlist_entry_safe(rcu_dereference_raw_check(hlist_next_rcu(\ &(pos)->member)), typeof(*(pos)), member)) /** |
