kernel/locking/mutex.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Mutexes: blocking mutual exclusion locks
 *
 * started by Ingo Molnar:
 *
 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 */

/*
 * This is the control structure for tasks blocked on mutex, which resides
 * on the blocked task's kernel stack:
 */
struct mutex_waiter {
	struct list_head	list;
	struct task_struct	*task;
	struct ww_acquire_ctx	*ww_ctx;
#ifdef CONFIG_DEBUG_MUTEXES
	void			*magic;
#endif
};

#ifdef CONFIG_DEBUG_MUTEXES
extern void debug_mutex_lock_common(struct mutex *lock,
				    struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
				    struct mutex_waiter *waiter);
extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
extern void debug_mutex_add_waiter(struct mutex *lock,
				   struct mutex_waiter *waiter,
				   struct task_struct *task);
extern void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
				      struct task_struct *task);
extern void debug_mutex_unlock(struct mutex *lock);
extern void debug_mutex_init(struct mutex *lock, const char *name,
			     struct lock_class_key *key);
#else /* CONFIG_DEBUG_MUTEXES */
# define debug_mutex_lock_common(lock, waiter)		do { } while (0)
# define debug_mutex_wake_waiter(lock, waiter)		do { } while (0)
# define debug_mutex_free_waiter(waiter)		do { } while (0)
# define debug_mutex_add_waiter(lock, waiter, ti)	do { } while (0)
# define debug_mutex_remove_waiter(lock, waiter, ti)	do { } while (0)
# define debug_mutex_unlock(lock)			do { } while (0)
# define debug_mutex_init(lock, name, key)		do { } while (0)
#endif /* !CONFIG_DEBUG_MUTEXES */