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> |
Alexey Dobriyan | d43c36d | 2009-10-07 17:09:06 +0400 | [diff] [blame] | 19 | #include <linux/sched.h> |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 20 | #include <linux/spinlock.h> |
| 21 | #include <linux/kallsyms.h> |
| 22 | #include <linux/interrupt.h> |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 23 | #include <linux/debug_locks.h> |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 24 | |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 25 | #include "mutex-debug.h" |
| 26 | |
| 27 | /* |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 28 | * Must be called with lock->wait_lock held. |
| 29 | */ |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 30 | void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 31 | { |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 32 | memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 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 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 39 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
| 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)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 43 | } |
| 44 | |
| 45 | void debug_mutex_free_waiter(struct mutex_waiter *waiter) |
| 46 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 47 | DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list)); |
Randy Dunlap | a7807a3 | 2006-06-27 02:53:54 -0700 | [diff] [blame] | 48 | memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 49 | } |
| 50 | |
| 51 | void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter, |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 52 | struct thread_info *ti) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 53 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 54 | SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock)); |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 55 | |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 56 | /* Mark the current thread as blocked on the lock: */ |
| 57 | ti->task->blocked_on = waiter; |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 58 | } |
| 59 | |
| 60 | void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter, |
| 61 | struct thread_info *ti) |
| 62 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 63 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); |
| 64 | DEBUG_LOCKS_WARN_ON(waiter->task != ti->task); |
| 65 | DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 66 | ti->task->blocked_on = NULL; |
| 67 | |
| 68 | list_del_init(&waiter->list); |
| 69 | waiter->task = NULL; |
| 70 | } |
| 71 | |
| 72 | void debug_mutex_unlock(struct mutex *lock) |
| 73 | { |
Ingo Molnar | 2ee91f1 | 2006-12-06 20:39:32 -0800 | [diff] [blame] | 74 | if (unlikely(!debug_locks)) |
| 75 | return; |
| 76 | |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 77 | DEBUG_LOCKS_WARN_ON(lock->magic != lock); |
Jeremy Kerr | 493d358 | 2008-05-14 16:22:58 -0700 | [diff] [blame] | 78 | DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 79 | DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); |
Peter Zijlstra | 0d66bf6 | 2009-01-12 14:01:47 +0100 | [diff] [blame] | 80 | mutex_clear_owner(lock); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 81 | } |
| 82 | |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 83 | void debug_mutex_init(struct mutex *lock, const char *name, |
| 84 | struct lock_class_key *key) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 85 | { |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 86 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 87 | /* |
| 88 | * Make sure we are not reinitializing a held lock: |
| 89 | */ |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 90 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
Peter Zijlstra | 4dfbb9d | 2006-10-11 01:45:14 -0400 | [diff] [blame] | 91 | lockdep_init_map(&lock->dep_map, name, key, 0); |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 92 | #endif |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 93 | lock->magic = lock; |
| 94 | } |
| 95 | |
| 96 | /*** |
| 97 | * mutex_destroy - mark a mutex unusable |
| 98 | * @lock: the mutex to be destroyed |
| 99 | * |
| 100 | * This function marks the mutex uninitialized, and any subsequent |
| 101 | * use of the mutex is forbidden. The mutex must not be locked when |
| 102 | * this function is called. |
| 103 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 104 | void mutex_destroy(struct mutex *lock) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 105 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 106 | DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 107 | lock->magic = NULL; |
| 108 | } |
| 109 | |
| 110 | EXPORT_SYMBOL_GPL(mutex_destroy); |