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- #include <linux/kdebug.h>
- #include <linux/kprobes.h>
- #include <linux/export.h>
- #include <linux/notifier.h>
- #include <linux/rcupdate.h>
- #include <linux/vmalloc.h>
- #include <linux/reboot.h>
- BLOCKING_NOTIFIER_HEAD(reboot_notifier_list);
- static int notifier_chain_register(struct notifier_block **nl,
- struct notifier_block *n)
- {
- while ((*nl) != NULL) {
- if (n->priority > (*nl)->priority)
- break;
- nl = &((*nl)->next);
- }
- n->next = *nl;
- rcu_assign_pointer(*nl, n);
- return 0;
- }
- static int notifier_chain_cond_register(struct notifier_block **nl,
- struct notifier_block *n)
- {
- while ((*nl) != NULL) {
- if ((*nl) == n)
- return 0;
- if (n->priority > (*nl)->priority)
- break;
- nl = &((*nl)->next);
- }
- n->next = *nl;
- rcu_assign_pointer(*nl, n);
- return 0;
- }
- static int notifier_chain_unregister(struct notifier_block **nl,
- struct notifier_block *n)
- {
- while ((*nl) != NULL) {
- if ((*nl) == n) {
- rcu_assign_pointer(*nl, n->next);
- return 0;
- }
- nl = &((*nl)->next);
- }
- return -ENOENT;
- }
- static int notifier_call_chain(struct notifier_block **nl,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
- {
- int ret = NOTIFY_DONE;
- struct notifier_block *nb, *next_nb;
- nb = rcu_dereference_raw(*nl);
- while (nb && nr_to_call) {
- next_nb = rcu_dereference_raw(nb->next);
- #ifdef CONFIG_DEBUG_NOTIFIERS
- if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) {
- WARN(1, "Invalid notifier called!");
- nb = next_nb;
- continue;
- }
- #endif
- ret = nb->notifier_call(nb, val, v);
- if (nr_calls)
- (*nr_calls)++;
- if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK)
- break;
- nb = next_nb;
- nr_to_call--;
- }
- return ret;
- }
- NOKPROBE_SYMBOL(notifier_call_chain);
- int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
- struct notifier_block *n)
- {
- unsigned long flags;
- int ret;
- spin_lock_irqsave(&nh->lock, flags);
- ret = notifier_chain_register(&nh->head, n);
- spin_unlock_irqrestore(&nh->lock, flags);
- return ret;
- }
- EXPORT_SYMBOL_GPL(atomic_notifier_chain_register);
- int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
- struct notifier_block *n)
- {
- unsigned long flags;
- int ret;
- spin_lock_irqsave(&nh->lock, flags);
- ret = notifier_chain_unregister(&nh->head, n);
- spin_unlock_irqrestore(&nh->lock, flags);
- synchronize_rcu();
- return ret;
- }
- EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
- int __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
- {
- int ret;
- rcu_read_lock();
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
- rcu_read_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain);
- NOKPROBE_SYMBOL(__atomic_notifier_call_chain);
- int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
- unsigned long val, void *v)
- {
- return __atomic_notifier_call_chain(nh, val, v, -1, NULL);
- }
- EXPORT_SYMBOL_GPL(atomic_notifier_call_chain);
- NOKPROBE_SYMBOL(atomic_notifier_call_chain);
- int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
- struct notifier_block *n)
- {
- int ret;
-
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_register(&nh->head, n);
- down_write(&nh->rwsem);
- ret = notifier_chain_register(&nh->head, n);
- up_write(&nh->rwsem);
- return ret;
- }
- EXPORT_SYMBOL_GPL(blocking_notifier_chain_register);
- int blocking_notifier_chain_cond_register(struct blocking_notifier_head *nh,
- struct notifier_block *n)
- {
- int ret;
- down_write(&nh->rwsem);
- ret = notifier_chain_cond_register(&nh->head, n);
- up_write(&nh->rwsem);
- return ret;
- }
- EXPORT_SYMBOL_GPL(blocking_notifier_chain_cond_register);
- int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh,
- struct notifier_block *n)
- {
- int ret;
-
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_unregister(&nh->head, n);
- down_write(&nh->rwsem);
- ret = notifier_chain_unregister(&nh->head, n);
- up_write(&nh->rwsem);
- return ret;
- }
- EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister);
- int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
- {
- int ret = NOTIFY_DONE;
-
- if (rcu_access_pointer(nh->head)) {
- down_read(&nh->rwsem);
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
- nr_calls);
- up_read(&nh->rwsem);
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain);
- int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
- unsigned long val, void *v)
- {
- return __blocking_notifier_call_chain(nh, val, v, -1, NULL);
- }
- EXPORT_SYMBOL_GPL(blocking_notifier_call_chain);
- int raw_notifier_chain_register(struct raw_notifier_head *nh,
- struct notifier_block *n)
- {
- return notifier_chain_register(&nh->head, n);
- }
- EXPORT_SYMBOL_GPL(raw_notifier_chain_register);
- int raw_notifier_chain_unregister(struct raw_notifier_head *nh,
- struct notifier_block *n)
- {
- return notifier_chain_unregister(&nh->head, n);
- }
- EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister);
- int __raw_notifier_call_chain(struct raw_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
- {
- return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
- }
- EXPORT_SYMBOL_GPL(__raw_notifier_call_chain);
- int raw_notifier_call_chain(struct raw_notifier_head *nh,
- unsigned long val, void *v)
- {
- return __raw_notifier_call_chain(nh, val, v, -1, NULL);
- }
- EXPORT_SYMBOL_GPL(raw_notifier_call_chain);
- #ifdef CONFIG_SRCU
- int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
- struct notifier_block *n)
- {
- int ret;
-
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_register(&nh->head, n);
- mutex_lock(&nh->mutex);
- ret = notifier_chain_register(&nh->head, n);
- mutex_unlock(&nh->mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(srcu_notifier_chain_register);
- int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh,
- struct notifier_block *n)
- {
- int ret;
-
- if (unlikely(system_state == SYSTEM_BOOTING))
- return notifier_chain_unregister(&nh->head, n);
- mutex_lock(&nh->mutex);
- ret = notifier_chain_unregister(&nh->head, n);
- mutex_unlock(&nh->mutex);
- synchronize_srcu(&nh->srcu);
- return ret;
- }
- EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister);
- int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
- {
- int ret;
- int idx;
- idx = srcu_read_lock(&nh->srcu);
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
- srcu_read_unlock(&nh->srcu, idx);
- return ret;
- }
- EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain);
- int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
- unsigned long val, void *v)
- {
- return __srcu_notifier_call_chain(nh, val, v, -1, NULL);
- }
- EXPORT_SYMBOL_GPL(srcu_notifier_call_chain);
- void srcu_init_notifier_head(struct srcu_notifier_head *nh)
- {
- mutex_init(&nh->mutex);
- if (init_srcu_struct(&nh->srcu) < 0)
- BUG();
- nh->head = NULL;
- }
- EXPORT_SYMBOL_GPL(srcu_init_notifier_head);
- #endif
- static ATOMIC_NOTIFIER_HEAD(die_chain);
- int notrace notify_die(enum die_val val, const char *str,
- struct pt_regs *regs, long err, int trap, int sig)
- {
- struct die_args args = {
- .regs = regs,
- .str = str,
- .err = err,
- .trapnr = trap,
- .signr = sig,
- };
- RCU_LOCKDEP_WARN(!rcu_is_watching(),
- "notify_die called but RCU thinks we're quiescent");
- return atomic_notifier_call_chain(&die_chain, val, &args);
- }
- NOKPROBE_SYMBOL(notify_die);
- int register_die_notifier(struct notifier_block *nb)
- {
- vmalloc_sync_all();
- return atomic_notifier_chain_register(&die_chain, nb);
- }
- EXPORT_SYMBOL_GPL(register_die_notifier);
- int unregister_die_notifier(struct notifier_block *nb)
- {
- return atomic_notifier_chain_unregister(&die_chain, nb);
- }
- EXPORT_SYMBOL_GPL(unregister_die_notifier);
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