Loading...
1/*
2 * Debugging code for mutexes
3 *
4 * Started by Ingo Molnar:
5 *
6 * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
7 *
8 * lock debugging, locking tree, deadlock detection started by:
9 *
10 * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
11 * Released under the General Public License (GPL).
12 */
13#include <linux/mutex.h>
14#include <linux/delay.h>
15#include <linux/device.h>
16#include <linux/export.h>
17#include <linux/poison.h>
18#include <linux/sched.h>
19#include <linux/spinlock.h>
20#include <linux/kallsyms.h>
21#include <linux/interrupt.h>
22#include <linux/debug_locks.h>
23
24#include "mutex.h"
25
26/*
27 * Must be called with lock->wait_lock held.
28 */
29void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
30{
31 memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
32 waiter->magic = waiter;
33 INIT_LIST_HEAD(&waiter->list);
34 waiter->ww_ctx = MUTEX_POISON_WW_CTX;
35}
36
37void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
38{
39 lockdep_assert_held(&lock->wait_lock);
40 DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
41 DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
42 DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
43}
44
45void debug_mutex_free_waiter(struct mutex_waiter *waiter)
46{
47 DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
48 memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
49}
50
51void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
52 struct task_struct *task)
53{
54 lockdep_assert_held(&lock->wait_lock);
55
56 /* Mark the current thread as blocked on the lock: */
57 task->blocked_on = waiter;
58}
59
60void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
61 struct task_struct *task)
62{
63 DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
64 DEBUG_LOCKS_WARN_ON(waiter->task != task);
65 DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter);
66 task->blocked_on = NULL;
67
68 INIT_LIST_HEAD(&waiter->list);
69 waiter->task = NULL;
70}
71
72void debug_mutex_unlock(struct mutex *lock)
73{
74 if (likely(debug_locks)) {
75 DEBUG_LOCKS_WARN_ON(lock->magic != lock);
76 DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
77 }
78}
79
80void debug_mutex_init(struct mutex *lock, const char *name,
81 struct lock_class_key *key)
82{
83#ifdef CONFIG_DEBUG_LOCK_ALLOC
84 /*
85 * Make sure we are not reinitializing a held lock:
86 */
87 debug_check_no_locks_freed((void *)lock, sizeof(*lock));
88 lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP);
89#endif
90 lock->magic = lock;
91}
92
93static void devm_mutex_release(void *res)
94{
95 mutex_destroy(res);
96}
97
98int __devm_mutex_init(struct device *dev, struct mutex *lock)
99{
100 return devm_add_action_or_reset(dev, devm_mutex_release, lock);
101}
102EXPORT_SYMBOL_GPL(__devm_mutex_init);
103
104/***
105 * mutex_destroy - mark a mutex unusable
106 * @lock: the mutex to be destroyed
107 *
108 * This function marks the mutex uninitialized, and any subsequent
109 * use of the mutex is forbidden. The mutex must not be locked when
110 * this function is called.
111 */
112void mutex_destroy(struct mutex *lock)
113{
114 DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
115 lock->magic = NULL;
116}
117
118EXPORT_SYMBOL_GPL(mutex_destroy);
1/*
2 * Debugging code for mutexes
3 *
4 * Started by Ingo Molnar:
5 *
6 * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
7 *
8 * lock debugging, locking tree, deadlock detection started by:
9 *
10 * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
11 * Released under the General Public License (GPL).
12 */
13#include <linux/mutex.h>
14#include <linux/delay.h>
15#include <linux/export.h>
16#include <linux/poison.h>
17#include <linux/sched.h>
18#include <linux/spinlock.h>
19#include <linux/kallsyms.h>
20#include <linux/interrupt.h>
21#include <linux/debug_locks.h>
22
23#include "mutex.h"
24
25/*
26 * Must be called with lock->wait_lock held.
27 */
28void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
29{
30 memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
31 waiter->magic = waiter;
32 INIT_LIST_HEAD(&waiter->list);
33 waiter->ww_ctx = MUTEX_POISON_WW_CTX;
34}
35
36void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
37{
38 lockdep_assert_held(&lock->wait_lock);
39 DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
40 DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
41 DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
42}
43
44void debug_mutex_free_waiter(struct mutex_waiter *waiter)
45{
46 DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
47 memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
48}
49
50void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
51 struct task_struct *task)
52{
53 lockdep_assert_held(&lock->wait_lock);
54
55 /* Mark the current thread as blocked on the lock: */
56 task->blocked_on = waiter;
57}
58
59void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
60 struct task_struct *task)
61{
62 DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
63 DEBUG_LOCKS_WARN_ON(waiter->task != task);
64 DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter);
65 task->blocked_on = NULL;
66
67 INIT_LIST_HEAD(&waiter->list);
68 waiter->task = NULL;
69}
70
71void debug_mutex_unlock(struct mutex *lock)
72{
73 if (likely(debug_locks)) {
74 DEBUG_LOCKS_WARN_ON(lock->magic != lock);
75 DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
76 }
77}
78
79void debug_mutex_init(struct mutex *lock, const char *name,
80 struct lock_class_key *key)
81{
82#ifdef CONFIG_DEBUG_LOCK_ALLOC
83 /*
84 * Make sure we are not reinitializing a held lock:
85 */
86 debug_check_no_locks_freed((void *)lock, sizeof(*lock));
87 lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP);
88#endif
89 lock->magic = lock;
90}
91
92/***
93 * mutex_destroy - mark a mutex unusable
94 * @lock: the mutex to be destroyed
95 *
96 * This function marks the mutex uninitialized, and any subsequent
97 * use of the mutex is forbidden. The mutex must not be locked when
98 * this function is called.
99 */
100void mutex_destroy(struct mutex *lock)
101{
102 DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
103 lock->magic = NULL;
104}
105
106EXPORT_SYMBOL_GPL(mutex_destroy);