1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
/*
* 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/delay.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/poison.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include "mutex.h"
/*
* Must be called with lock->wait_lock held.
*/
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);
waiter->ww_ctx = MUTEX_POISON_WW_CTX;
}
void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
{
lockdep_assert_held(&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 task_struct *task)
{
lockdep_assert_held(&lock->wait_lock);
/* Mark the current thread as blocked on the lock: */
task->blocked_on = waiter;
}
void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct task_struct *task)
{
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
DEBUG_LOCKS_WARN_ON(waiter->task != task);
DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter);
task->blocked_on = NULL;
INIT_LIST_HEAD(&waiter->list);
waiter->task = NULL;
}
void debug_mutex_unlock(struct mutex *lock)
{
if (likely(debug_locks)) {
DEBUG_LOCKS_WARN_ON(lock->magic != lock);
DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
}
}
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_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP);
#endif
lock->magic = lock;
}
static void devm_mutex_release(void *res)
{
mutex_destroy(res);
}
int __devm_mutex_init(struct device *dev, struct mutex *lock)
{
return devm_add_action_or_reset(dev, devm_mutex_release, lock);
}
EXPORT_SYMBOL_GPL(__devm_mutex_init);
/***
* 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 mutex_destroy(struct mutex *lock)
{
DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
lock->magic = NULL;
}
EXPORT_SYMBOL_GPL(mutex_destroy);
|
