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408894ee IM |
1 | /* |
2 | * kernel/mutex-debug.c | |
3 | * | |
4 | * Debugging code for mutexes | |
5 | * | |
6 | * Started by Ingo Molnar: | |
7 | * | |
8 | * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com> | |
9 | * | |
10 | * lock debugging, locking tree, deadlock detection started by: | |
11 | * | |
12 | * Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey | |
13 | * Released under the General Public License (GPL). | |
14 | */ | |
15 | #include <linux/mutex.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/module.h> | |
a7807a32 | 19 | #include <linux/poison.h> |
408894ee IM |
20 | #include <linux/spinlock.h> |
21 | #include <linux/kallsyms.h> | |
22 | #include <linux/interrupt.h> | |
9a11b49a | 23 | #include <linux/debug_locks.h> |
408894ee | 24 | |
408894ee IM |
25 | #include "mutex-debug.h" |
26 | ||
408894ee IM |
27 | /* |
28 | * Must be called with lock->wait_lock held. | |
29 | */ | |
9a11b49a | 30 | void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner) |
408894ee IM |
31 | { |
32 | lock->owner = new_owner; | |
408894ee IM |
33 | } |
34 | ||
9a11b49a | 35 | void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) |
408894ee | 36 | { |
a7807a32 | 37 | memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); |
408894ee IM |
38 | waiter->magic = waiter; |
39 | INIT_LIST_HEAD(&waiter->list); | |
40 | } | |
41 | ||
42 | void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter) | |
43 | { | |
9e7f4d45 IM |
44 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
45 | DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list)); | |
46 | DEBUG_LOCKS_WARN_ON(waiter->magic != waiter); | |
47 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); | |
408894ee IM |
48 | } |
49 | ||
50 | void debug_mutex_free_waiter(struct mutex_waiter *waiter) | |
51 | { | |
9e7f4d45 | 52 | DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list)); |
a7807a32 | 53 | memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter)); |
408894ee IM |
54 | } |
55 | ||
56 | void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter, | |
9a11b49a | 57 | struct thread_info *ti) |
408894ee | 58 | { |
9e7f4d45 | 59 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
9a11b49a | 60 | |
408894ee IM |
61 | /* Mark the current thread as blocked on the lock: */ |
62 | ti->task->blocked_on = waiter; | |
63 | waiter->lock = lock; | |
64 | } | |
65 | ||
66 | void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, | |
67 | struct thread_info *ti) | |
68 | { | |
9e7f4d45 IM |
69 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); |
70 | DEBUG_LOCKS_WARN_ON(waiter->task != ti->task); | |
71 | DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter); | |
408894ee IM |
72 | ti->task->blocked_on = NULL; |
73 | ||
74 | list_del_init(&waiter->list); | |
75 | waiter->task = NULL; | |
76 | } | |
77 | ||
78 | void debug_mutex_unlock(struct mutex *lock) | |
79 | { | |
9a11b49a | 80 | DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); |
9e7f4d45 IM |
81 | DEBUG_LOCKS_WARN_ON(lock->magic != lock); |
82 | DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); | |
83 | DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); | |
408894ee IM |
84 | } |
85 | ||
ef5d4707 IM |
86 | void debug_mutex_init(struct mutex *lock, const char *name, |
87 | struct lock_class_key *key) | |
408894ee | 88 | { |
ef5d4707 | 89 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
408894ee IM |
90 | /* |
91 | * Make sure we are not reinitializing a held lock: | |
92 | */ | |
9a11b49a | 93 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
4dfbb9d8 | 94 | lockdep_init_map(&lock->dep_map, name, key, 0); |
ef5d4707 | 95 | #endif |
408894ee | 96 | lock->owner = NULL; |
408894ee IM |
97 | lock->magic = lock; |
98 | } | |
99 | ||
100 | /*** | |
101 | * mutex_destroy - mark a mutex unusable | |
102 | * @lock: the mutex to be destroyed | |
103 | * | |
104 | * This function marks the mutex uninitialized, and any subsequent | |
105 | * use of the mutex is forbidden. The mutex must not be locked when | |
106 | * this function is called. | |
107 | */ | |
108 | void fastcall mutex_destroy(struct mutex *lock) | |
109 | { | |
9e7f4d45 | 110 | DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)); |
408894ee IM |
111 | lock->magic = NULL; |
112 | } | |
113 | ||
114 | EXPORT_SYMBOL_GPL(mutex_destroy); |