[linux-2.6-block.git] / lib / spinlock_debug.c

/*
 * Copyright 2005, Red Hat, Inc., Ingo Molnar
 * Released under the General Public License (GPL).
 *
 * This file contains the spinlock/rwlock implementations for
 * DEBUG_SPINLOCK.
 */

#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include <linux/delay.h>
#include <linux/module.h>

void __spin_lock_init(spinlock_t *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);
#endif
	lock->raw_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
	lock->magic = SPINLOCK_MAGIC;
	lock->owner = SPINLOCK_OWNER_INIT;
	lock->owner_cpu = -1;
}

EXPORT_SYMBOL(__spin_lock_init);

void __rwlock_init(rwlock_t *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);
#endif
	lock->raw_lock = (raw_rwlock_t) __RAW_RW_LOCK_UNLOCKED;
	lock->magic = RWLOCK_MAGIC;
	lock->owner = SPINLOCK_OWNER_INIT;
	lock->owner_cpu = -1;
}

EXPORT_SYMBOL(__rwlock_init);

static void spin_bug(spinlock_t *lock, const char *msg)
{
	struct task_struct *owner = NULL;

	if (!debug_locks_off())
		return;

	if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT)
		owner = lock->owner;
	printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n",
		msg, raw_smp_processor_id(),
		current->comm, current->pid);
	printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, "
			".owner_cpu: %d\n",
		lock, lock->magic,
		owner ? owner->comm : "<none>",
		owner ? owner->pid : -1,
		lock->owner_cpu);
	dump_stack();
}

#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)

static inline void
debug_spin_lock_before(spinlock_t *lock)
{
	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
	SPIN_BUG_ON(lock->owner == current, lock, "recursion");
	SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
							lock, "cpu recursion");
}

static inline void debug_spin_lock_after(spinlock_t *lock)
{
	lock->owner_cpu = raw_smp_processor_id();
	lock->owner = current;
}

static inline void debug_spin_unlock(spinlock_t *lock)
{
	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
	SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked");
	SPIN_BUG_ON(lock->owner != current, lock, "wrong owner");
	SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
							lock, "wrong CPU");
	lock->owner = SPINLOCK_OWNER_INIT;
	lock->owner_cpu = -1;
}

static void __spin_lock_debug(spinlock_t *lock)
{
	int print_once = 1;
	u64 i;

	for (;;) {
		for (i = 0; i < loops_per_jiffy * HZ; i++) {
			if (__raw_spin_trylock(&lock->raw_lock))
				return;
			__delay(1);
		}
		/* lockup suspected: */
		if (print_once) {
			print_once = 0;
			printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, "
					"%s/%d, %p\n",
				raw_smp_processor_id(), current->comm,
				current->pid, lock);
			dump_stack();
		}
	}
}

void _raw_spin_lock(spinlock_t *lock)
{
	debug_spin_lock_before(lock);
	if (unlikely(!__raw_spin_trylock(&lock->raw_lock)))
		__spin_lock_debug(lock);
	debug_spin_lock_after(lock);
}

int _raw_spin_trylock(spinlock_t *lock)
{
	int ret = __raw_spin_trylock(&lock->raw_lock);

	if (ret)
		debug_spin_lock_after(lock);
#ifndef CONFIG_SMP
	/*
	 * Must not happen on UP:
	 */
	SPIN_BUG_ON(!ret, lock, "trylock failure on UP");
#endif
	return ret;
}

void _raw_spin_unlock(spinlock_t *lock)
{
	debug_spin_unlock(lock);
	__raw_spin_unlock(&lock->raw_lock);
}

static void rwlock_bug(rwlock_t *lock, const char *msg)
{
	if (!debug_locks_off())
		return;

	printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n",
		msg, raw_smp_processor_id(), current->comm,
		current->pid, lock);
	dump_stack();
}

#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)

#if 0		/* __write_lock_debug() can lock up - maybe this can too? */
static void __read_lock_debug(rwlock_t *lock)
{
	int print_once = 1;
	u64 i;

	for (;;) {
		for (i = 0; i < loops_per_jiffy * HZ; i++) {
			if (__raw_read_trylock(&lock->raw_lock))
				return;
			__delay(1);
		}
		/* lockup suspected: */
		if (print_once) {
			print_once = 0;
			printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, "
					"%s/%d, %p\n",
				raw_smp_processor_id(), current->comm,
				current->pid, lock);
			dump_stack();
		}
	}
}
#endif

void _raw_read_lock(rwlock_t *lock)
{
	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	__raw_read_lock(&lock->raw_lock);
}

int _raw_read_trylock(rwlock_t *lock)
{
	int ret = __raw_read_trylock(&lock->raw_lock);

#ifndef CONFIG_SMP
	/*
	 * Must not happen on UP:
	 */
	RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
#endif
	return ret;
}

void _raw_read_unlock(rwlock_t *lock)
{
	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	__raw_read_unlock(&lock->raw_lock);
}

static inline void debug_write_lock_before(rwlock_t *lock)
{
	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	RWLOCK_BUG_ON(lock->owner == current, lock, "recursion");
	RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
							lock, "cpu recursion");
}

static inline void debug_write_lock_after(rwlock_t *lock)
{
	lock->owner_cpu = raw_smp_processor_id();
	lock->owner = current;
}

static inline void debug_write_unlock(rwlock_t *lock)
{
	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner");
	RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
							lock, "wrong CPU");
	lock->owner = SPINLOCK_OWNER_INIT;
	lock->owner_cpu = -1;
}

#if 0		/* This can cause lockups */
static void __write_lock_debug(rwlock_t *lock)
{
	int print_once = 1;
	u64 i;

	for (;;) {
		for (i = 0; i < loops_per_jiffy * HZ; i++) {
			if (__raw_write_trylock(&lock->raw_lock))
				return;
			__delay(1);
		}
		/* lockup suspected: */
		if (print_once) {
			print_once = 0;
			printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, "
					"%s/%d, %p\n",
				raw_smp_processor_id(), current->comm,
				current->pid, lock);
			dump_stack();
		}
	}
}
#endif

void _raw_write_lock(rwlock_t *lock)
{
	debug_write_lock_before(lock);
	__raw_write_lock(&lock->raw_lock);
	debug_write_lock_after(lock);
}

int _raw_write_trylock(rwlock_t *lock)
{
	int ret = __raw_write_trylock(&lock->raw_lock);

	if (ret)
		debug_write_lock_after(lock);
#ifndef CONFIG_SMP
	/*
	 * Must not happen on UP:
	 */
	RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
#endif
	return ret;
}

void _raw_write_unlock(rwlock_t *lock)
{
	debug_write_unlock(lock);
	__raw_write_unlock(&lock->raw_lock);
}
Commit	Line	Data
fb1c8f93 IM	1	/*
	2	* Copyright 2005, Red Hat, Inc., Ingo Molnar
	3	* Released under the General Public License (GPL).
	4	*
	5	* This file contains the spinlock/rwlock implementations for
	6	* DEBUG_SPINLOCK.
	7	*/
	8
fb1c8f93 IM	9	#include <linux/spinlock.h>
fb1c8f93 IM	10	#include <linux/interrupt.h>
9a11b49a	11	#include <linux/debug_locks.h>
fb1c8f93	12	#include <linux/delay.h>
9a11b49a	13	#include <linux/module.h>
fb1c8f93	14
8a25d5de IM	15	void __spin_lock_init(spinlock_t lock, const char name,
	16	struct lock_class_key *key)
	17	{
	18	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	19	/*
	20	* Make sure we are not reinitializing a held lock:
	21	*/
	22	debug_check_no_locks_freed((void )lock, sizeof(lock));
	23	lockdep_init_map(&lock->dep_map, name, key);
	24	#endif
	25	lock->raw_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
	26	lock->magic = SPINLOCK_MAGIC;
	27	lock->owner = SPINLOCK_OWNER_INIT;
	28	lock->owner_cpu = -1;
	29	}
	30
	31	EXPORT_SYMBOL(__spin_lock_init);
	32
	33	void __rwlock_init(rwlock_t lock, const char name,
	34	struct lock_class_key *key)
	35	{
	36	#ifdef CONFIG_DEBUG_LOCK_ALLOC
	37	/*
	38	* Make sure we are not reinitializing a held lock:
	39	*/
	40	debug_check_no_locks_freed((void )lock, sizeof(lock));
	41	lockdep_init_map(&lock->dep_map, name, key);
	42	#endif
	43	lock->raw_lock = (raw_rwlock_t) __RAW_RW_LOCK_UNLOCKED;
	44	lock->magic = RWLOCK_MAGIC;
	45	lock->owner = SPINLOCK_OWNER_INIT;
	46	lock->owner_cpu = -1;
	47	}
	48
	49	EXPORT_SYMBOL(__rwlock_init);
	50
fb1c8f93 IM	51	static void spin_bug(spinlock_t lock, const char msg)
fb1c8f93 IM	52	{
fb1c8f93 IM	53	struct task_struct *owner = NULL;
fb1c8f93 IM	54
9a11b49a IM	55	if (!debug_locks_off())
	56	return;
	57
	58	if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT)
	59	owner = lock->owner;
	60	printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n",
	61	msg, raw_smp_processor_id(),
	62	current->comm, current->pid);
	63	printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, "
	64	".owner_cpu: %d\n",
	65	lock, lock->magic,
	66	owner ? owner->comm : "<none>",
	67	owner ? owner->pid : -1,
	68	lock->owner_cpu);
	69	dump_stack();
fb1c8f93 IM	70	}
	71
	72	#define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg)
	73
9a11b49a IM	74	static inline void
9a11b49a IM	75	debug_spin_lock_before(spinlock_t *lock)
fb1c8f93 IM	76	{
	77	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
	78	SPIN_BUG_ON(lock->owner == current, lock, "recursion");
	79	SPIN_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
	80	lock, "cpu recursion");
	81	}
	82
	83	static inline void debug_spin_lock_after(spinlock_t *lock)
	84	{
	85	lock->owner_cpu = raw_smp_processor_id();
	86	lock->owner = current;
	87	}
	88
	89	static inline void debug_spin_unlock(spinlock_t *lock)
	90	{
	91	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");
	92	SPIN_BUG_ON(!spin_is_locked(lock), lock, "already unlocked");
	93	SPIN_BUG_ON(lock->owner != current, lock, "wrong owner");
	94	SPIN_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
	95	lock, "wrong CPU");
	96	lock->owner = SPINLOCK_OWNER_INIT;
	97	lock->owner_cpu = -1;
	98	}
	99
	100	static void __spin_lock_debug(spinlock_t *lock)
	101	{
	102	int print_once = 1;
	103	u64 i;
	104
	105	for (;;) {
	106	for (i = 0; i < loops_per_jiffy * HZ; i++) {
fb1c8f93 IM	107	if (__raw_spin_trylock(&lock->raw_lock))
fb1c8f93 IM	108	return;
e0a60296	109	__delay(1);
fb1c8f93 IM	110	}
	111	/* lockup suspected: */
	112	if (print_once) {
	113	print_once = 0;
51989b9f DJ	114	printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, "
51989b9f DJ	115	"%s/%d, %p\n",
bb44f116 IM	116	raw_smp_processor_id(), current->comm,
bb44f116 IM	117	current->pid, lock);
fb1c8f93 IM	118	dump_stack();
	119	}
	120	}
	121	}
	122
	123	void _raw_spin_lock(spinlock_t *lock)
	124	{
	125	debug_spin_lock_before(lock);
	126	if (unlikely(!__raw_spin_trylock(&lock->raw_lock)))
	127	__spin_lock_debug(lock);
	128	debug_spin_lock_after(lock);
	129	}
	130
	131	int _raw_spin_trylock(spinlock_t *lock)
	132	{
	133	int ret = __raw_spin_trylock(&lock->raw_lock);
	134
	135	if (ret)
	136	debug_spin_lock_after(lock);
	137	#ifndef CONFIG_SMP
	138	/*
	139	* Must not happen on UP:
	140	*/
	141	SPIN_BUG_ON(!ret, lock, "trylock failure on UP");
	142	#endif
	143	return ret;
	144	}
	145
	146	void _raw_spin_unlock(spinlock_t *lock)
	147	{
	148	debug_spin_unlock(lock);
	149	__raw_spin_unlock(&lock->raw_lock);
	150	}
	151
	152	static void rwlock_bug(rwlock_t lock, const char msg)
	153	{
9a11b49a IM	154	if (!debug_locks_off())
	155	return;
	156
	157	printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n",
	158	msg, raw_smp_processor_id(), current->comm,
	159	current->pid, lock);
	160	dump_stack();
fb1c8f93 IM	161	}
	162
	163	#define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg)
	164
72f0b4e2	165	#if 0 /* __write_lock_debug() can lock up - maybe this can too? */
fb1c8f93 IM	166	static void __read_lock_debug(rwlock_t *lock)
	167	{
	168	int print_once = 1;
	169	u64 i;
	170
	171	for (;;) {
	172	for (i = 0; i < loops_per_jiffy * HZ; i++) {
fb1c8f93 IM	173	if (__raw_read_trylock(&lock->raw_lock))
fb1c8f93 IM	174	return;
e0a60296	175	__delay(1);
fb1c8f93 IM	176	}
	177	/* lockup suspected: */
	178	if (print_once) {
	179	print_once = 0;
51989b9f DJ	180	printk(KERN_EMERG "BUG: read-lock lockup on CPU#%d, "
51989b9f DJ	181	"%s/%d, %p\n",
bb44f116 IM	182	raw_smp_processor_id(), current->comm,
bb44f116 IM	183	current->pid, lock);
fb1c8f93 IM	184	dump_stack();
	185	}
	186	}
	187	}
72f0b4e2	188	#endif
fb1c8f93 IM	189
	190	void _raw_read_lock(rwlock_t *lock)
	191	{
	192	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
72f0b4e2	193	__raw_read_lock(&lock->raw_lock);
fb1c8f93 IM	194	}
	195
	196	int _raw_read_trylock(rwlock_t *lock)
	197	{
	198	int ret = __raw_read_trylock(&lock->raw_lock);
	199
	200	#ifndef CONFIG_SMP
	201	/*
	202	* Must not happen on UP:
	203	*/
	204	RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
	205	#endif
	206	return ret;
	207	}
	208
	209	void _raw_read_unlock(rwlock_t *lock)
	210	{
	211	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	212	__raw_read_unlock(&lock->raw_lock);
	213	}
	214
	215	static inline void debug_write_lock_before(rwlock_t *lock)
	216	{
	217	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	218	RWLOCK_BUG_ON(lock->owner == current, lock, "recursion");
	219	RWLOCK_BUG_ON(lock->owner_cpu == raw_smp_processor_id(),
	220	lock, "cpu recursion");
	221	}
	222
	223	static inline void debug_write_lock_after(rwlock_t *lock)
	224	{
	225	lock->owner_cpu = raw_smp_processor_id();
	226	lock->owner = current;
	227	}
	228
	229	static inline void debug_write_unlock(rwlock_t *lock)
	230	{
	231	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");
	232	RWLOCK_BUG_ON(lock->owner != current, lock, "wrong owner");
	233	RWLOCK_BUG_ON(lock->owner_cpu != raw_smp_processor_id(),
	234	lock, "wrong CPU");
	235	lock->owner = SPINLOCK_OWNER_INIT;
	236	lock->owner_cpu = -1;
	237	}
	238
72f0b4e2	239	#if 0 /* This can cause lockups */
fb1c8f93 IM	240	static void __write_lock_debug(rwlock_t *lock)
	241	{
	242	int print_once = 1;
	243	u64 i;
	244
	245	for (;;) {
	246	for (i = 0; i < loops_per_jiffy * HZ; i++) {
fb1c8f93 IM	247	if (__raw_write_trylock(&lock->raw_lock))
fb1c8f93 IM	248	return;
e0a60296	249	__delay(1);
fb1c8f93 IM	250	}
	251	/* lockup suspected: */
	252	if (print_once) {
	253	print_once = 0;
51989b9f DJ	254	printk(KERN_EMERG "BUG: write-lock lockup on CPU#%d, "
51989b9f DJ	255	"%s/%d, %p\n",
bb44f116 IM	256	raw_smp_processor_id(), current->comm,
bb44f116 IM	257	current->pid, lock);
fb1c8f93 IM	258	dump_stack();
	259	}
	260	}
	261	}
72f0b4e2	262	#endif
fb1c8f93 IM	263
	264	void _raw_write_lock(rwlock_t *lock)
	265	{
	266	debug_write_lock_before(lock);
72f0b4e2	267	__raw_write_lock(&lock->raw_lock);
fb1c8f93 IM	268	debug_write_lock_after(lock);
	269	}
	270
	271	int _raw_write_trylock(rwlock_t *lock)
	272	{
	273	int ret = __raw_write_trylock(&lock->raw_lock);
	274
	275	if (ret)
	276	debug_write_lock_after(lock);
	277	#ifndef CONFIG_SMP
	278	/*
	279	* Must not happen on UP:
	280	*/
	281	RWLOCK_BUG_ON(!ret, lock, "trylock failure on UP");
	282	#endif
	283	return ret;
	284	}
	285
	286	void _raw_write_unlock(rwlock_t *lock)
	287	{
	288	debug_write_unlock(lock);
	289	__raw_write_unlock(&lock->raw_lock);
	290	}