Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
tag: v2.6.27-rc3
Fetching contributors…

Cannot retrieve contributors at this time

file 116 lines (102 sloc) 3.117 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
/*
* kernel/mutex-debug.c
*
* Debugging code for mutexes
*
* Started by Ingo Molnar:
*
* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*
* lock debugging, locking tree, deadlock detection started by:
*
* Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
* Released under the General Public License (GPL).
*/
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/poison.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>

#include "mutex-debug.h"

/*
* Must be called with lock->wait_lock held.
*/
void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner)
{
lock->owner = new_owner;
}

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
waiter->magic = waiter;
INIT_LIST_HEAD(&waiter->list);
}

void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
{
SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
}

void debug_mutex_free_waiter(struct mutex_waiter *waiter)
{
DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
}

void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct thread_info *ti)
{
SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));

/* Mark the current thread as blocked on the lock: */
ti->task->blocked_on = waiter;
waiter->lock = lock;
}

void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct thread_info *ti)
{
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
DEBUG_LOCKS_WARN_ON(waiter->task != ti->task);
DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter);
ti->task->blocked_on = NULL;

list_del_init(&waiter->list);
waiter->task = NULL;
}

void debug_mutex_unlock(struct mutex *lock)
{
if (unlikely(!debug_locks))
return;

DEBUG_LOCKS_WARN_ON(lock->magic != lock);
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
}

void debug_mutex_init(struct mutex *lock, const char *name,
struct lock_class_key *key)
{
#ifdef CONFIG_DEBUG_LOCK_ALLOC
/*
* Make sure we are not reinitializing a held lock:
*/
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
lock->owner = NULL;
lock->magic = lock;
}

/***
* mutex_destroy - mark a mutex unusable
* @lock: the mutex to be destroyed
*
* This function marks the mutex uninitialized, and any subsequent
* use of the mutex is forbidden. The mutex must not be locked when
* this function is called.
*/
void mutex_destroy(struct mutex *lock)
{
DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
lock->magic = NULL;
}

EXPORT_SYMBOL_GPL(mutex_destroy);
Something went wrong with that request. Please try again.