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> |
Paul Gortmaker | 9984de1 | 2011-05-23 14:51:41 -0400 | [diff] [blame] | 17 | #include <linux/export.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, |
Linus Torvalds | 6720a30 | 2016-06-23 12:11:17 -0700 | [diff] [blame] | 52 | struct task_struct *task) |
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: */ |
Linus Torvalds | 6720a30 | 2016-06-23 12:11:17 -0700 | [diff] [blame] | 57 | 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, |
Linus Torvalds | 6720a30 | 2016-06-23 12:11:17 -0700 | [diff] [blame] | 61 | struct task_struct *task) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 62 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 63 | DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list)); |
Linus Torvalds | 6720a30 | 2016-06-23 12:11:17 -0700 | [diff] [blame] | 64 | DEBUG_LOCKS_WARN_ON(waiter->task != task); |
| 65 | DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter); |
| 66 | task->blocked_on = NULL; |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 67 | |
| 68 | list_del_init(&waiter->list); |
| 69 | waiter->task = NULL; |
| 70 | } |
| 71 | |
| 72 | void debug_mutex_unlock(struct mutex *lock) |
| 73 | { |
Peter Zijlstra | a227960 | 2014-04-10 16:15:59 +0200 | [diff] [blame] | 74 | if (likely(debug_locks)) { |
| 75 | DEBUG_LOCKS_WARN_ON(lock->magic != lock); |
Ingo Molnar | 2ee91f1 | 2006-12-06 20:39:32 -0800 | [diff] [blame] | 76 | |
Peter Zijlstra | a227960 | 2014-04-10 16:15:59 +0200 | [diff] [blame] | 77 | if (!lock->owner) |
| 78 | DEBUG_LOCKS_WARN_ON(!lock->owner); |
| 79 | else |
| 80 | DEBUG_LOCKS_WARN_ON(lock->owner != current); |
Chuansheng Liu | 91f30a1 | 2013-12-04 13:58:13 +0800 | [diff] [blame] | 81 | |
Peter Zijlstra | a227960 | 2014-04-10 16:15:59 +0200 | [diff] [blame] | 82 | DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); |
Peter Zijlstra | a227960 | 2014-04-10 16:15:59 +0200 | [diff] [blame] | 83 | } |
Peter Zijlstra | 6f008e7 | 2014-03-12 13:24:42 +0100 | [diff] [blame] | 84 | |
| 85 | /* |
| 86 | * __mutex_slowpath_needs_to_unlock() is explicitly 0 for debug |
| 87 | * mutexes so that we can do it here after we've verified state. |
| 88 | */ |
Chris Wilson | a63b03e | 2015-01-06 10:29:35 +0000 | [diff] [blame] | 89 | mutex_clear_owner(lock); |
Peter Zijlstra | 6f008e7 | 2014-03-12 13:24:42 +0100 | [diff] [blame] | 90 | atomic_set(&lock->count, 1); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 91 | } |
| 92 | |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 93 | void debug_mutex_init(struct mutex *lock, const char *name, |
| 94 | struct lock_class_key *key) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 95 | { |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 96 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 97 | /* |
| 98 | * Make sure we are not reinitializing a held lock: |
| 99 | */ |
Ingo Molnar | 9a11b49a | 2006-07-03 00:24:33 -0700 | [diff] [blame] | 100 | debug_check_no_locks_freed((void *)lock, sizeof(*lock)); |
Peter Zijlstra | 4dfbb9d | 2006-10-11 01:45:14 -0400 | [diff] [blame] | 101 | lockdep_init_map(&lock->dep_map, name, key, 0); |
Ingo Molnar | ef5d470 | 2006-07-03 00:24:55 -0700 | [diff] [blame] | 102 | #endif |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 103 | lock->magic = lock; |
| 104 | } |
| 105 | |
| 106 | /*** |
| 107 | * mutex_destroy - mark a mutex unusable |
| 108 | * @lock: the mutex to be destroyed |
| 109 | * |
| 110 | * This function marks the mutex uninitialized, and any subsequent |
| 111 | * use of the mutex is forbidden. The mutex must not be locked when |
| 112 | * this function is called. |
| 113 | */ |
Harvey Harrison | 7ad5b3a | 2008-02-08 04:19:53 -0800 | [diff] [blame] | 114 | void mutex_destroy(struct mutex *lock) |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 115 | { |
Ingo Molnar | 9e7f4d4 | 2006-07-03 00:24:30 -0700 | [diff] [blame] | 116 | DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock)); |
Ingo Molnar | 408894e | 2006-01-09 15:59:20 -0800 | [diff] [blame] | 117 | lock->magic = NULL; |
| 118 | } |
| 119 | |
| 120 | EXPORT_SYMBOL_GPL(mutex_destroy); |