path: root/lib/locking-selftest.c

/*
 * lib/locking-selftest.c
 *
 * Testsuite for various locking APIs: spinlocks, rwlocks,
 * mutexes and rw-semaphores.
 *
 * It is checking both false positives and false negatives.
 *
 * Started by Ingo Molnar:
 *
 *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 */
#include <linux/rwsem.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/lockdep.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/irqflags.h>

/*
 * Change this to 1 if you want to see the failure printouts:
 */
static unsigned int debug_locks_verbose;

static int __init setup_debug_locks_verbose(char *str)
{
	get_option(&str, &debug_locks_verbose);

	return 1;
}

__setup("debug_locks_verbose=", setup_debug_locks_verbose);

#define FAILURE		0
#define SUCCESS		1

#define LOCKTYPE_SPIN	0x1
#define LOCKTYPE_RWLOCK	0x2
#define LOCKTYPE_MUTEX	0x4
#define LOCKTYPE_RWSEM	0x8

/*
 * Normal standalone locks, for the circular and irq-context
 * dependency tests:
 */
static DEFINE_SPINLOCK(lock_A);
static DEFINE_SPINLOCK(lock_B);
static DEFINE_SPINLOCK(lock_C);
static DEFINE_SPINLOCK(lock_D);

static DEFINE_RWLOCK(rwlock_A);
static DEFINE_RWLOCK(rwlock_B);
static DEFINE_RWLOCK(rwlock_C);
static DEFINE_RWLOCK(rwlock_D);

static DEFINE_MUTEX(mutex_A);
static DEFINE_MUTEX(mutex_B);
static DEFINE_MUTEX(mutex_C);
static DEFINE_MUTEX(mutex_D);

static DECLARE_RWSEM(rwsem_A);
static DECLARE_RWSEM(rwsem_B);
static DECLARE_RWSEM(rwsem_C);
static DECLARE_RWSEM(rwsem_D);

/*
 * Locks that we initialize dynamically as well so that
 * e.g. X1 and X2 becomes two instances of the same class,
 * but X* and Y* are different classes. We do this so that
 * we do not trigger a real lockup:
 */
static DEFINE_SPINLOCK(lock_X1);
static DEFINE_SPINLOCK(lock_X2);
static DEFINE_SPINLOCK(lock_Y1);
static DEFINE_SPINLOCK(lock_Y2);
static DEFINE_SPINLOCK(lock_Z1);
static DEFINE_SPINLOCK(lock_Z2);

static DEFINE_RWLOCK(rwlock_X1);
static DEFINE_RWLOCK(rwlock_X2);
static DEFINE_RWLOCK(rwlock_Y1);
static DEFINE_RWLOCK(rwlock_Y2);
static DEFINE_RWLOCK(rwlock_Z1);
static DEFINE_RWLOCK(rwlock_Z2);

static DEFINE_MUTEX(mutex_X1);
static DEFINE_MUTEX(mutex_X2);
static DEFINE_MUTEX(mutex_Y1);
static DEFINE_MUTEX(mutex_Y2);
static DEFINE_MUTEX(mutex_Z1);
static DEFINE_MUTEX(mutex_Z2);

static DECLARE_RWSEM(rwsem_X1);
static DECLARE_RWSEM(rwsem_X2);
static DECLARE_RWSEM(rwsem_Y1);
static DECLARE_RWSEM(rwsem_Y2);
static DECLARE_RWSEM(rwsem_Z1);
static DECLARE_RWSEM(rwsem_Z2);

/*
 * non-inlined runtime initializers, to let separate locks share
 * the same lock-class:
 */
#define INIT_CLASS_FUNC(class) 				\
static noinline void					\
init_class_##class(spinlock_t *lock, rwlock_t *rwlock, struct mutex *mutex, \
		 struct rw_semaphore *rwsem)		\
{							\
	spin_lock_init(lock);				\
	rwlock_init(rwlock);				\
	mutex_init(mutex);				\
	init_rwsem(rwsem);				\
}

INIT_CLASS_FUNC(X)
INIT_CLASS_FUNC(Y)
INIT_CLASS_FUNC(Z)

static void init_shared_classes(void)
{
	init_class_X(&lock_X1, &rwlock_X1, &mutex_X1, &rwsem_X1);
	init_class_X(&lock_X2, &rwlock_X2, &mutex_X2, &rwsem_X2);

	init_class_Y(&lock_Y1, &rwlock_Y1, &mutex_Y1, &rwsem_Y1);
	init_class_Y(&lock_Y2, &rwlock_Y2, &mutex_Y2, &rwsem_Y2);

	init_class_Z(&lock_Z1, &rwlock_Z1, &mutex_Z1, &rwsem_Z1);
	init_class_Z(&lock_Z2, &rwlock_Z2, &mutex_Z2, &rwsem_Z2);
}

/*
 * For spinlocks and rwlocks we also do hardirq-safe / softirq-safe tests.
 * The following functions use a lock from a simulated hardirq/s