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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - kernel/mutex-debug.c
4 * Debugging code for mutexes
6 * Started by Ingo Molnar:
8 * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
10 * lock debugging, locking tree, deadlock detection started by:
12 * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
13 * Released under the General Public License (GPL).
15 #include <linux/mutex.h>
16 #include <linux/delay.h>
17 #include <linux/module.h>
18 #include <linux/poison.h>
19 #include <linux/spinlock.h>
20 #include <linux/kallsyms.h>
21 #include <linux/interrupt.h>
22 #include <linux/debug_locks.h>
24 #include "mutex-debug.h"
27 * Must be called with lock->wait_lock held.
29 void debug_mutex_set_owner(struct mutex
*lock
, struct thread_info
*new_owner
)
31 lock
->owner
= new_owner
;
34 void debug_mutex_lock_common(struct mutex
*lock
, struct mutex_waiter
*waiter
)
36 memset(waiter
, MUTEX_DEBUG_INIT
, sizeof(*waiter
));
37 waiter
->magic
= waiter
;
38 INIT_LIST_HEAD(&waiter
->list
);
41 void debug_mutex_wake_waiter(struct mutex
*lock
, struct mutex_waiter
*waiter
)
43 SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock
->wait_lock
));
44 DEBUG_LOCKS_WARN_ON(list_empty(&lock
->wait_list
));
45 DEBUG_LOCKS_WARN_ON(waiter
->magic
!= waiter
);
46 DEBUG_LOCKS_WARN_ON(list_empty(&waiter
->list
));
49 void debug_mutex_free_waiter(struct mutex_waiter
*waiter
)
51 DEBUG_LOCKS_WARN_ON(!list_empty(&waiter
->list
));
52 memset(waiter
, MUTEX_DEBUG_FREE
, sizeof(*waiter
));
55 void debug_mutex_add_waiter(struct mutex
*lock
, struct mutex_waiter
*waiter
,
56 struct thread_info
*ti
)
58 SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock
->wait_lock
));
60 /* Mark the current thread as blocked on the lock: */
61 ti
->task
->blocked_on
= waiter
;
65 void mutex_remove_waiter(struct mutex
*lock
, struct mutex_waiter
*waiter
,
66 struct thread_info
*ti
)
68 DEBUG_LOCKS_WARN_ON(list_empty(&waiter
->list
));
69 DEBUG_LOCKS_WARN_ON(waiter
->task
!= ti
->task
);
70 DEBUG_LOCKS_WARN_ON(ti
->task
->blocked_on
!= waiter
);
71 ti
->task
->blocked_on
= NULL
;
73 list_del_init(&waiter
->list
);
77 void debug_mutex_unlock(struct mutex
*lock
)
79 if (unlikely(!debug_locks
))
82 DEBUG_LOCKS_WARN_ON(lock
->owner
!= current_thread_info());
83 DEBUG_LOCKS_WARN_ON(lock
->magic
!= lock
);
84 DEBUG_LOCKS_WARN_ON(!lock
->wait_list
.prev
&& !lock
->wait_list
.next
);
85 DEBUG_LOCKS_WARN_ON(lock
->owner
!= current_thread_info());
88 void debug_mutex_init(struct mutex
*lock
, const char *name
,
89 struct lock_class_key
*key
)
91 #ifdef CONFIG_DEBUG_LOCK_ALLOC
93 * Make sure we are not reinitializing a held lock:
95 debug_check_no_locks_freed((void *)lock
, sizeof(*lock
));
96 lockdep_init_map(&lock
->dep_map
, name
, key
, 0);
103 * mutex_destroy - mark a mutex unusable
104 * @lock: the mutex to be destroyed
106 * This function marks the mutex uninitialized, and any subsequent
107 * use of the mutex is forbidden. The mutex must not be locked when
108 * this function is called.
110 void mutex_destroy(struct mutex
*lock
)
112 DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock
));
116 EXPORT_SYMBOL_GPL(mutex_destroy
);