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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> | |
408894ee | 16 | #include <linux/delay.h> |
9984de1a | 17 | #include <linux/export.h> |
a7807a32 | 18 | #include <linux/poison.h> |
d43c36dc | 19 | #include <linux/sched.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_lock_common(struct mutex *lock, struct mutex_waiter *waiter) |
408894ee | 31 | { |
a7807a32 | 32 | memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); |
408894ee IM |
33 | waiter->magic = waiter; |
34 | INIT_LIST_HEAD(&waiter->list); | |
35 | } | |
36 | ||
37 | void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter) | |
38 | { | |
9e7f4d45 | 39 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
6fa3eb70 S |
40 | if(DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list))){ |
41 | printk("[MUTEX WARN!!]\n"); | |
42 | } | |
43 | if(DEBUG_LOCKS_WARN_ON(waiter->magic != waiter)){ | |
44 | printk("[MUTEX WARN!!] bad magic number %p:%p\n", waiter->magic, waiter); | |
45 | } | |
46 | if(DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list))){ | |
47 | printk("[MUTEX WARN!!] empt waiter list\n"); | |
48 | } | |
408894ee IM |
49 | } |
50 | ||
51 | void debug_mutex_free_waiter(struct mutex_waiter *waiter) | |
52 | { | |
9e7f4d45 | 53 | DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list)); |
a7807a32 | 54 | memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter)); |
408894ee IM |
55 | } |
56 | ||
57 | void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter, | |
9a11b49a | 58 | struct thread_info *ti) |
408894ee | 59 | { |
9e7f4d45 | 60 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
9a11b49a | 61 | |
408894ee IM |
62 | /* Mark the current thread as blocked on the lock: */ |
63 | ti->task->blocked_on = waiter; | |
6fa3eb70 S |
64 | #ifdef CONFIG_MT_DEBUG_MUTEXES |
65 | waiter->task_wait_on = lock->owner; | |
66 | #endif | |
408894ee IM |
67 | } |
68 | ||
69 | void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, | |
70 | struct thread_info *ti) | |
71 | { | |
6fa3eb70 S |
72 | if(DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list))){ |
73 | printk("[MUTEX WARN!!] empty waiter list\n"); | |
74 | } | |
75 | if(DEBUG_LOCKS_WARN_ON(waiter->task != ti->task)){ | |
76 | printk("[MUTEX WARN!!] waiter task is not the same![%d:%s] != [%d:%s]\n", waiter->task->pid, waiter->task->comm, ti->task->pid, ti->task->comm); | |
77 | } | |
78 | if(DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter)){ | |
79 | printk("[MUTEX WARN!!] blocked on different waiter\n"); | |
80 | } | |
408894ee IM |
81 | ti->task->blocked_on = NULL; |
82 | ||
83 | list_del_init(&waiter->list); | |
84 | waiter->task = NULL; | |
6fa3eb70 S |
85 | #ifdef CONFIG_MT_DEBUG_MUTEXES |
86 | waiter->task_wait_on = NULL; | |
87 | #endif | |
408894ee IM |
88 | } |
89 | ||
90 | void debug_mutex_unlock(struct mutex *lock) | |
91 | { | |
6fa3eb70 S |
92 | // if (unlikely(!debug_locks)) |
93 | // return; | |
2ee91f19 | 94 | |
6fa3eb70 S |
95 | if(DEBUG_LOCKS_WARN_ON(lock->magic != lock)){ |
96 | printk("[MUTEX WARN!!] bad lock magic:%p\n", lock->magic); | |
97 | } | |
98 | if(DEBUG_LOCKS_WARN_ON(lock->owner != current)){ | |
99 | if(lock->owner != NULL){ | |
100 | printk("[MUTEX WARN!!] releasing mutex which is hold by another process, %p\n", lock->owner); | |
101 | printk("[MUTEX WARN!!] current process[%d:%s] is trying to release lock\n But it should be released by lock owner-process[%d:%s]\n", current->pid, current->comm, lock->owner->pid, lock->owner->comm); | |
102 | }else | |
103 | printk("\n[MUTEX WARN!!] imbalanced unlock\n"); | |
104 | } | |
105 | if(DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next)){ | |
106 | printk("[MUTEX WARN!!] wait_list both empty in prev and next \n"); | |
107 | } | |
0d66bf6d | 108 | mutex_clear_owner(lock); |
408894ee IM |
109 | } |
110 | ||
ef5d4707 IM |
111 | void debug_mutex_init(struct mutex *lock, const char *name, |
112 | struct lock_class_key *key) | |
408894ee | 113 | { |
ef5d4707 | 114 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
408894ee IM |
115 | /* |
116 | * Make sure we are not reinitializing a held lock: | |
117 | */ | |
9a11b49a | 118 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
4dfbb9d8 | 119 | lockdep_init_map(&lock->dep_map, name, key, 0); |
6fa3eb70 S |
120 | #endif |
121 | #ifdef CONFIG_DEBUG_MUTEXES | |
122 | lock->name = name; | |
ef5d4707 | 123 | #endif |
408894ee IM |
124 | lock->magic = lock; |
125 | } | |
126 | ||
127 | /*** | |
128 | * mutex_destroy - mark a mutex unusable | |
129 | * @lock: the mutex to be destroyed | |
130 | * | |
131 | * This function marks the mutex uninitialized, and any subsequent | |
132 | * use of the mutex is forbidden. The mutex must not be locked when | |
133 | * this function is called. | |
134 | */ | |
7ad5b3a5 | 135 | void mutex_destroy(struct mutex *lock) |
408894ee | 136 | { |
9e7f4d45 | 137 | DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)); |
408894ee IM |
138 | lock->magic = NULL; |
139 | } | |
140 | ||
141 | EXPORT_SYMBOL_GPL(mutex_destroy); |