Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 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> |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 16 | #include <linux/delay.h> |
| 17 | #include <linux/module.h> |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 18 | #include <linux/poison.h> |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/kallsyms.h> |
| 21 | #include <linux/interrupt.h> |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 22 | #include <linux/debug_locks.h> |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 23 | |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 24 | #include "mutex-debug.h" |
| 25 | |
| 26 | /* |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 27 | * Must be called with lock->wait_lock held. |
| 28 | */ |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 29 | void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 30 | { |
| 31 | lock->owner = new_owner; |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 32 | } |
| 33 | |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 34 | void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 35 | { |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 36 | memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 37 | waiter->magic = waiter; |
| 38 | INIT_LIST_HEAD(&waiter->list); |
| 39 | } |
| 40 | |
| 41 | void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter) |
| 42 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 43 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
| 44 | DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list)); |
| 45 | DEBUG_LOCKS_WARN_ON(waiter->magic != waiter); |
| 46 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 47 | } |
| 48 | |
| 49 | void debug_mutex_free_waiter(struct mutex_waiter *waiter) |
| 50 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 51 | DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list)); |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 52 | memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 53 | } |
| 54 | |
| 55 | void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter, |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 56 | struct thread_info *ti) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 57 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 58 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 59 | |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 60 | /* Mark the current thread as blocked on the lock: */ |
| 61 | ti->task->blocked_on = waiter; |
| 62 | waiter->lock = lock; |
| 63 | } |
| 64 | |
| 65 | void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, |
| 66 | struct thread_info *ti) |
| 67 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 68 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); |
| 69 | DEBUG_LOCKS_WARN_ON(waiter->task != ti->task); |
| 70 | DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 71 | ti->task->blocked_on = NULL; |
| 72 | |
| 73 | list_del_init(&waiter->list); |
| 74 | waiter->task = NULL; |
| 75 | } |
| 76 | |
| 77 | void debug_mutex_unlock(struct mutex *lock) |
| 78 | { |
Ingo Molnar | 2ee91f1 | 2006-12-06 20:39:32 -0800 | [diff] [blame] | 79 | if (unlikely(!debug_locks)) |
| 80 | return; |
| 81 | |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 82 | DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 83 | DEBUG_LOCKS_WARN_ON(lock->magic != lock); |
| 84 | DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); |
| 85 | DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 86 | } |
| 87 | |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 88 | void debug_mutex_init(struct mutex *lock, const char *name, |
| 89 | struct lock_class_key *key) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 90 | { |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 91 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 92 | /* |
| 93 | * Make sure we are not reinitializing a held lock: |
| 94 | */ |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 95 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
Peter Zijlstra | 4dfbb9d | 2006-10-11 01:45:14 -0400 | [diff] [blame] | 96 | lockdep_init_map(&lock->dep_map, name, key, 0); |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 97 | #endif |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 98 | lock->owner = NULL; |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 99 | lock->magic = lock; |
| 100 | } |
| 101 | |
| 102 | /*** |
| 103 | * mutex_destroy - mark a mutex unusable |
| 104 | * @lock: the mutex to be destroyed |
| 105 | * |
| 106 | * This function marks the mutex uninitialized, and any subsequent |
| 107 | * use of the mutex is forbidden. The mutex must not be locked when |
| 108 | * this function is called. |
| 109 | */ |
| 110 | void fastcall mutex_destroy(struct mutex *lock) |
| 111 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 112 | DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 113 | lock->magic = NULL; |
| 114 | } |
| 115 | |
| 116 | EXPORT_SYMBOL_GPL(mutex_destroy); |