ia64/linux-2.6.18-xen.hg

view kernel/mutex-debug.c @ 562:66faefe721eb

pvSCSI backend driver

Signed-off-by: Tomonari Horikoshi <t.horikoshi@jp.fujitsu.com>
Signed-off-by: Jun Kamada <kama@jp.fujitsu.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Jun 02 09:58:27 2008 +0100 (2008-06-02)
parents 831230e53067
children
line source
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>
19 #include <linux/poison.h>
20 #include <linux/spinlock.h>
21 #include <linux/kallsyms.h>
22 #include <linux/interrupt.h>
23 #include <linux/debug_locks.h>
25 #include "mutex-debug.h"
27 /*
28 * Must be called with lock->wait_lock held.
29 */
30 void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner)
31 {
32 lock->owner = new_owner;
33 }
35 void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
36 {
37 memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
38 waiter->magic = waiter;
39 INIT_LIST_HEAD(&waiter->list);
40 }
42 void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
43 {
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));
48 }
50 void debug_mutex_free_waiter(struct mutex_waiter *waiter)
51 {
52 DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
53 memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
54 }
56 void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
57 struct thread_info *ti)
58 {
59 SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
61 /* Mark the current thread as blocked on the lock: */
62 ti->task->blocked_on = waiter;
63 waiter->lock = lock;
64 }
66 void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
67 struct thread_info *ti)
68 {
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);
72 ti->task->blocked_on = NULL;
74 list_del_init(&waiter->list);
75 waiter->task = NULL;
76 }
78 void debug_mutex_unlock(struct mutex *lock)
79 {
80 DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
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());
84 }
86 void debug_mutex_init(struct mutex *lock, const char *name,
87 struct lock_class_key *key)
88 {
89 #ifdef CONFIG_DEBUG_LOCK_ALLOC
90 /*
91 * Make sure we are not reinitializing a held lock:
92 */
93 debug_check_no_locks_freed((void *)lock, sizeof(*lock));
94 lockdep_init_map(&lock->dep_map, name, key);
95 #endif
96 lock->owner = NULL;
97 lock->magic = lock;
98 }
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 {
110 DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
111 lock->magic = NULL;
112 }
114 EXPORT_SYMBOL_GPL(mutex_destroy);