4dfbb9d8c6
This annotation makes it possible to assign a subclass on lock init. This annotation is meant to reduce the _nested() annotations by assigning a default subclass. One could do without this annotation and rely on lockdep_set_class() exclusively, but that would require a manual stack of struct lock_class_key objects. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
115 lines
3.0 KiB
C
115 lines
3.0 KiB
C
/*
|
|
* kernel/mutex-debug.c
|
|
*
|
|
* 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/sched.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/module.h>
|
|
#include <linux/poison.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/debug_locks.h>
|
|
|
|
#include "mutex-debug.h"
|
|
|
|
/*
|
|
* Must be called with lock->wait_lock held.
|
|
*/
|
|
void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner)
|
|
{
|
|
lock->owner = new_owner;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
|
|
{
|
|
SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
|
|
DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
|
|
DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
|
|
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
|
|
}
|
|
|
|
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 thread_info *ti)
|
|
{
|
|
SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
|
|
|
|
/* Mark the current thread as blocked on the lock: */
|
|
ti->task->blocked_on = waiter;
|
|
waiter->lock = lock;
|
|
}
|
|
|
|
void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
|
|
struct thread_info *ti)
|
|
{
|
|
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
|
|
DEBUG_LOCKS_WARN_ON(waiter->task != ti->task);
|
|
DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter);
|
|
ti->task->blocked_on = NULL;
|
|
|
|
list_del_init(&waiter->list);
|
|
waiter->task = NULL;
|
|
}
|
|
|
|
void debug_mutex_unlock(struct mutex *lock)
|
|
{
|
|
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
|
|
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
|
|
DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
|
|
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
|
|
}
|
|
|
|
void debug_mutex_init(struct mutex *lock, const char *name,
|
|
struct lock_class_key *key)
|
|
{
|
|
#ifdef CONFIG_DEBUG_LOCK_ALLOC
|
|
/*
|
|
* Make sure we are not reinitializing a held lock:
|
|
*/
|
|
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
|
|
lockdep_init_map(&lock->dep_map, name, key, 0);
|
|
#endif
|
|
lock->owner = NULL;
|
|
lock->magic = lock;
|
|
}
|
|
|
|
/***
|
|
* 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 fastcall mutex_destroy(struct mutex *lock)
|
|
{
|
|
DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
|
|
lock->magic = NULL;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(mutex_destroy);
|