b88ca48e7e8aa351d3eeb9326f9f0b347d79d2d6
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/export.h>
18 #include <linux/poison.h>
19 #include <linux/sched.h>
20 #include <linux/spinlock.h>
21 #include <linux/kallsyms.h>
22 #include <linux/interrupt.h>
23 #include <linux/debug_locks.h>
25 #include "mutex-debug.h"
28 * Must be called with lock->wait_lock held.
30 void debug_mutex_lock_common(struct mutex
*lock
, struct mutex_waiter
*waiter
)
32 memset(waiter
, MUTEX_DEBUG_INIT
, sizeof(*waiter
));
33 waiter
->magic
= waiter
;
34 INIT_LIST_HEAD(&waiter
->list
);
37 void debug_mutex_wake_waiter(struct mutex
*lock
, struct mutex_waiter
*waiter
)
39 SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock
->wait_lock
));
40 if(DEBUG_LOCKS_WARN_ON(list_empty(&lock
->wait_list
))){
41 printk("[MUTEX WARN!!]\n");
43 if(DEBUG_LOCKS_WARN_ON(waiter
->magic
!= waiter
)){
44 printk("[MUTEX WARN!!] bad magic number %p:%p\n", waiter
->magic
, waiter
);
46 if(DEBUG_LOCKS_WARN_ON(list_empty(&waiter
->list
))){
47 printk("[MUTEX WARN!!] empt waiter list\n");
51 void debug_mutex_free_waiter(struct mutex_waiter
*waiter
)
53 DEBUG_LOCKS_WARN_ON(!list_empty(&waiter
->list
));
54 memset(waiter
, MUTEX_DEBUG_FREE
, sizeof(*waiter
));
57 void debug_mutex_add_waiter(struct mutex
*lock
, struct mutex_waiter
*waiter
,
58 struct thread_info
*ti
)
60 SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock
->wait_lock
));
62 /* Mark the current thread as blocked on the lock: */
63 ti
->task
->blocked_on
= waiter
;
64 #ifdef CONFIG_MT_DEBUG_MUTEXES
65 waiter
->task_wait_on
= lock
->owner
;
69 void mutex_remove_waiter(struct mutex
*lock
, struct mutex_waiter
*waiter
,
70 struct thread_info
*ti
)
72 if(DEBUG_LOCKS_WARN_ON(list_empty(&waiter
->list
))){
73 printk("[MUTEX WARN!!] empty waiter list\n");
75 if(DEBUG_LOCKS_WARN_ON(waiter
->task
!= ti
->task
)){
76 printk("[MUTEX WARN!!] waiter task is not the same![%d:%s] != [%d:%s]\n", waiter
->task
->pid
, waiter
->task
->comm
, ti
->task
->pid
, ti
->task
->comm
);
78 if(DEBUG_LOCKS_WARN_ON(ti
->task
->blocked_on
!= waiter
)){
79 printk("[MUTEX WARN!!] blocked on different waiter\n");
81 ti
->task
->blocked_on
= NULL
;
83 list_del_init(&waiter
->list
);
85 #ifdef CONFIG_MT_DEBUG_MUTEXES
86 waiter
->task_wait_on
= NULL
;
90 void debug_mutex_unlock(struct mutex
*lock
)
92 // if (unlikely(!debug_locks))
95 if(DEBUG_LOCKS_WARN_ON(lock
->magic
!= lock
)){
96 printk("[MUTEX WARN!!] bad lock magic:%p\n", lock
->magic
);
98 if(DEBUG_LOCKS_WARN_ON(lock
->owner
!= current
)){
99 if(lock
->owner
!= NULL
){
100 printk("[MUTEX WARN!!] releasing mutex which is hold by another process, %p\n", lock
->owner
);
101 printk("[MUTEX WARN!!] current process[%d:%s] is trying to release lock\n But it should be released by lock owner-process[%d:%s]\n", current
->pid
, current
->comm
, lock
->owner
->pid
, lock
->owner
->comm
);
103 printk("\n[MUTEX WARN!!] imbalanced unlock\n");
105 if(DEBUG_LOCKS_WARN_ON(!lock
->wait_list
.prev
&& !lock
->wait_list
.next
)){
106 printk("[MUTEX WARN!!] wait_list both empty in prev and next \n");
108 mutex_clear_owner(lock
);
111 void debug_mutex_init(struct mutex
*lock
, const char *name
,
112 struct lock_class_key
*key
)
114 #ifdef CONFIG_DEBUG_LOCK_ALLOC
116 * Make sure we are not reinitializing a held lock:
118 debug_check_no_locks_freed((void *)lock
, sizeof(*lock
));
119 lockdep_init_map(&lock
->dep_map
, name
, key
, 0);
121 #ifdef CONFIG_DEBUG_MUTEXES
128 * mutex_destroy - mark a mutex unusable
129 * @lock: the mutex to be destroyed
131 * This function marks the mutex uninitialized, and any subsequent
132 * use of the mutex is forbidden. The mutex must not be locked when
133 * this function is called.
135 void mutex_destroy(struct mutex
*lock
)
137 DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock
));
141 EXPORT_SYMBOL_GPL(mutex_destroy
);