Commit | Line | Data |
---|---|---|
408894ee | 1 | /* |
408894ee IM |
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> | |
408894ee | 14 | #include <linux/delay.h> |
4cd47222 | 15 | #include <linux/device.h> |
9984de1a | 16 | #include <linux/export.h> |
a7807a32 | 17 | #include <linux/poison.h> |
d43c36dc | 18 | #include <linux/sched.h> |
408894ee IM |
19 | #include <linux/spinlock.h> |
20 | #include <linux/kallsyms.h> | |
21 | #include <linux/interrupt.h> | |
9a11b49a | 22 | #include <linux/debug_locks.h> |
408894ee | 23 | |
a321fb90 | 24 | #include "mutex.h" |
408894ee | 25 | |
408894ee IM |
26 | /* |
27 | * Must be called with lock->wait_lock held. | |
28 | */ | |
9a11b49a | 29 | void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) |
408894ee | 30 | { |
a7807a32 | 31 | memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); |
408894ee IM |
32 | waiter->magic = waiter; |
33 | INIT_LIST_HEAD(&waiter->list); | |
c0afb0ff | 34 | waiter->ww_ctx = MUTEX_POISON_WW_CTX; |
408894ee IM |
35 | } |
36 | ||
37 | void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter) | |
38 | { | |
04547728 | 39 | lockdep_assert_held(&lock->wait_lock); |
9e7f4d45 IM |
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)); | |
408894ee IM |
43 | } |
44 | ||
45 | void debug_mutex_free_waiter(struct mutex_waiter *waiter) | |
46 | { | |
9e7f4d45 | 47 | DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list)); |
a7807a32 | 48 | memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter)); |
408894ee IM |
49 | } |
50 | ||
51 | void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter, | |
6720a305 | 52 | struct task_struct *task) |
408894ee | 53 | { |
04547728 | 54 | lockdep_assert_held(&lock->wait_lock); |
9a11b49a | 55 | |
408894ee | 56 | /* Mark the current thread as blocked on the lock: */ |
6720a305 | 57 | task->blocked_on = waiter; |
408894ee IM |
58 | } |
59 | ||
3a010c49 | 60 | void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, |
6720a305 | 61 | struct task_struct *task) |
408894ee | 62 | { |
9e7f4d45 | 63 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); |
6720a305 LT |
64 | DEBUG_LOCKS_WARN_ON(waiter->task != task); |
65 | DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter); | |
66 | task->blocked_on = NULL; | |
408894ee | 67 | |
3a010c49 | 68 | INIT_LIST_HEAD(&waiter->list); |
408894ee IM |
69 | waiter->task = NULL; |
70 | } | |
71 | ||
72 | void debug_mutex_unlock(struct mutex *lock) | |
73 | { | |
a227960f PZ |
74 | if (likely(debug_locks)) { |
75 | DEBUG_LOCKS_WARN_ON(lock->magic != lock); | |
a227960f | 76 | DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); |
a227960f | 77 | } |
408894ee IM |
78 | } |
79 | ||
ef5d4707 IM |
80 | void debug_mutex_init(struct mutex *lock, const char *name, |
81 | struct lock_class_key *key) | |
408894ee | 82 | { |
ef5d4707 | 83 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
408894ee IM |
84 | /* |
85 | * Make sure we are not reinitializing a held lock: | |
86 | */ | |
9a11b49a | 87 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
de8f5e4f | 88 | lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP); |
ef5d4707 | 89 | #endif |
408894ee IM |
90 | lock->magic = lock; |
91 | } | |
92 | ||
4cd47222 GS |
93 | static void devm_mutex_release(void *res) |
94 | { | |
95 | mutex_destroy(res); | |
96 | } | |
97 | ||
98 | int __devm_mutex_init(struct device *dev, struct mutex *lock) | |
99 | { | |
100 | return devm_add_action_or_reset(dev, devm_mutex_release, lock); | |
101 | } | |
102 | EXPORT_SYMBOL_GPL(__devm_mutex_init); | |
103 | ||
408894ee IM |
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 | */ | |
7ad5b3a5 | 112 | void mutex_destroy(struct mutex *lock) |
408894ee | 113 | { |
9e7f4d45 | 114 | DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)); |
408894ee IM |
115 | lock->magic = NULL; |
116 | } | |
117 | ||
118 | EXPORT_SYMBOL_GPL(mutex_destroy); |