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> |
9984de1a | 15 | #include <linux/export.h> |
a7807a32 | 16 | #include <linux/poison.h> |
d43c36dc | 17 | #include <linux/sched.h> |
408894ee IM |
18 | #include <linux/spinlock.h> |
19 | #include <linux/kallsyms.h> | |
20 | #include <linux/interrupt.h> | |
9a11b49a | 21 | #include <linux/debug_locks.h> |
408894ee | 22 | |
a321fb90 | 23 | #include "mutex.h" |
408894ee | 24 | |
408894ee IM |
25 | /* |
26 | * Must be called with lock->wait_lock held. | |
27 | */ | |
9a11b49a | 28 | void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) |
408894ee | 29 | { |
a7807a32 | 30 | memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); |
408894ee IM |
31 | waiter->magic = waiter; |
32 | INIT_LIST_HEAD(&waiter->list); | |
c0afb0ff | 33 | waiter->ww_ctx = MUTEX_POISON_WW_CTX; |
408894ee IM |
34 | } |
35 | ||
36 | void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter) | |
37 | { | |
04547728 | 38 | lockdep_assert_held(&lock->wait_lock); |
9e7f4d45 IM |
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)); | |
408894ee IM |
42 | } |
43 | ||
44 | void debug_mutex_free_waiter(struct mutex_waiter *waiter) | |
45 | { | |
9e7f4d45 | 46 | DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list)); |
a7807a32 | 47 | memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter)); |
408894ee IM |
48 | } |
49 | ||
50 | void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter, | |
6720a305 | 51 | struct task_struct *task) |
408894ee | 52 | { |
04547728 | 53 | lockdep_assert_held(&lock->wait_lock); |
9a11b49a | 54 | |
408894ee | 55 | /* Mark the current thread as blocked on the lock: */ |
6720a305 | 56 | task->blocked_on = waiter; |
408894ee IM |
57 | } |
58 | ||
3a010c49 | 59 | void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, |
6720a305 | 60 | struct task_struct *task) |
408894ee | 61 | { |
9e7f4d45 | 62 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); |
6720a305 LT |
63 | DEBUG_LOCKS_WARN_ON(waiter->task != task); |
64 | DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter); | |
65 | task->blocked_on = NULL; | |
408894ee | 66 | |
3a010c49 | 67 | INIT_LIST_HEAD(&waiter->list); |
408894ee IM |
68 | waiter->task = NULL; |
69 | } | |
70 | ||
71 | void debug_mutex_unlock(struct mutex *lock) | |
72 | { | |
a227960f PZ |
73 | if (likely(debug_locks)) { |
74 | DEBUG_LOCKS_WARN_ON(lock->magic != lock); | |
a227960f | 75 | DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); |
a227960f | 76 | } |
408894ee IM |
77 | } |
78 | ||
ef5d4707 IM |
79 | void debug_mutex_init(struct mutex *lock, const char *name, |
80 | struct lock_class_key *key) | |
408894ee | 81 | { |
ef5d4707 | 82 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
408894ee IM |
83 | /* |
84 | * Make sure we are not reinitializing a held lock: | |
85 | */ | |
9a11b49a | 86 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
de8f5e4f | 87 | lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP); |
ef5d4707 | 88 | #endif |
408894ee IM |
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 | */ | |
7ad5b3a5 | 100 | void mutex_destroy(struct mutex *lock) |
408894ee | 101 | { |
9e7f4d45 | 102 | DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)); |
408894ee IM |
103 | lock->magic = NULL; |
104 | } | |
105 | ||
106 | EXPORT_SYMBOL_GPL(mutex_destroy); |