linux-master/kernel/notifier.c

25 static int notifier_chain_register(struct notifier_block **nl,
29 	while ((*nl) != NULL) {
30 		if (unlikely((*nl) == n)) {
35 		if (n->priority > (*nl)->priority)
37 		if (n->priority == (*nl)->priority && unique_priority)
39 		nl = &((*nl)->next);
41 	n->next = *nl;
42 	rcu_assign_pointer(*nl, n);
47 static int notifier_chain_unregister(struct notifier_block **nl,
50 	while ((*nl) != NULL) {
51 		if ((*nl) == n) {
52 			rcu_assign_pointer(*nl, n->next);
56 		nl = &((*nl)->next);
63  *	@nl:		Pointer to head of the blocking notifier chain
73 static int notifier_call_chain(struct notifier_block **nl,
80 	nb = rcu_dereference_raw(*nl);
110  * @nl:		Pointer to head of the blocking notifier chain
116  * NOTE:	It is important the @nl chain doesn't change between the two
122 static int notifier_call_chain_robust(struct notifier_block **nl,
128 	ret = notifier_call_chain(nl, val_up, v, -1, &nr);
130 		notifier_call_chain(nl, val_down, v, nr-1, NULL);