/* * Debugging code for mutexes * * Started by Ingo Molnar: * *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> * * lock debugging, locking tree, deadlock detection started by: * *  Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey *  Released under the General Public License (GPL). */#include <linux/mutex.h>#include <linux/delay.h>#include <linux/device.h>#include <linux/export.h>#include <linux/poison.h>#include <linux/sched.h>#include <linux/spinlock.h>#include <linux/kallsyms.h>#include <linux/interrupt.h>#include <linux/debug_locks.h> #include "mutex.h" /* * Must be called with lock->wait_lock held. */void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter){	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));	waiter->magic = waiter;	INIT_LIST_HEAD(&waiter->list);	waiter->ww_ctx = MUTEX_POISON_WW_CTX;} void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter){	lockdep_assert_held(&lock->wait_lock);	DEBUG_LOCKS_WARN_ON(!lock->first_waiter);	DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);} void debug_mutex_free_waiter(struct mutex_waiter *waiter){	DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));	memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));} void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,			    struct task_struct *task){	lockdep_assert_held(&lock->wait_lock); 	/* Current thread can't be already blocked (since it's executing!) */	DEBUG_LOCKS_WARN_ON(get_task_blocked_on(task));} void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,			 struct task_struct *task){	struct mutex *blocked_on = get_task_blocked_on(task); 	DEBUG_LOCKS_WARN_ON(waiter->task != task);	DEBUG_LOCKS_WARN_ON(blocked_on && blocked_on != lock); 	INIT_LIST_HEAD(&waiter->list);	waiter->task = NULL;} void debug_mutex_unlock(struct mutex *lock){	if (likely(debug_locks)) {		DEBUG_LOCKS_WARN_ON(lock->magic != lock);	}} void debug_mutex_init(struct mutex *lock){	lock->magic = lock;} static void devm_mutex_release(void *res){	mutex_destroy(res);} int __devm_mutex_init(struct device *dev, struct mutex *lock){	return devm_add_action_or_reset(dev, devm_mutex_release, lock);}EXPORT_SYMBOL_GPL(__devm_mutex_init); /*** * mutex_destroy - mark a mutex unusable * @lock: the mutex to be destroyed * * This function marks the mutex uninitialized, and any subsequent * use of the mutex is forbidden. The mutex must not be locked when * this function is called. */void mutex_destroy(struct mutex *lock){	DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));	lock->magic = NULL;} EXPORT_SYMBOL_GPL(mutex_destroy);