/* * 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/nmi.h>#include <linux/interrupt.h>#include <linux/debug_locks.h>#include <linux/delay.h>#include <linux/export.h> void __raw_spin_lock_init(raw_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, 0);#endif	lock->raw_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;	lock->magic = SPINLOCK_MAGIC;	lock->owner = SPINLOCK_OWNER_INIT;	lock->owner_cpu = -1;} EXPORT_SYMBOL(__raw_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, 0);#endif	lock->raw_lock = (arch_rwlock_t) __ARCH_RW_LOCK_UNLOCKED;	lock->magic = RWLOCK_MAGIC;	lock->owner = SPINLOCK_OWNER_INIT;	lock->owner_cpu = -1;} EXPORT_SYMBOL(__rwlock_init); static void spin_dump(raw_spinlock_t *lock, const char *msg){	struct task_struct *owner = NULL; 	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, task_pid_nr(current));	printk(KERN_EMERG " lock: %ps, .magic: %08x, .owner: %s/%d, "			".owner_cpu: %d\n",		lock, lock->magic,		owner ? owner->comm : "<none>",		owner ? task_pid_nr(owner) : -1,		lock->owner_cpu);	dump_stack();} static void spin_bug(raw_spinlock_t *lock, const char *msg){	if (!debug_locks_off())		return; 	spin_dump(lock, msg);} #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) static inline voiddebug_spin_lock_before(raw_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(raw_spinlock_t *lock){	lock->owner_cpu = raw_smp_processor_id();	lock->owner = current;} static inline void debug_spin_unlock(raw_spinlock_t *lock){	SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic");	SPIN_BUG_ON(!raw_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(raw_spinlock_t *lock){	u64 i;	u64 loops = loops_per_jiffy * HZ;	int print_once = 1; 	for (;;) {		for (i = 0; i < loops; i++) {			if (arch_spin_trylock(&lock->raw_lock))				return;			__delay(1);		}		/* lockup suspected: */		if (print_once) {			print_once = 0;			spin_dump(lock, "lockup suspected");#ifdef CONFIG_SMP			trigger_all_cpu_backtrace();#endif		}	}} void do_raw_spin_lock(raw_spinlock_t *lock){	debug_spin_lock_before(lock);	if (unlikely(!arch_spin_trylock(&lock->raw_lock)))		__spin_lock_debug(lock);	debug_spin_lock_after(lock);} int do_raw_spin_trylock(raw_spinlock_t *lock){	int ret = arch_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 do_raw_spin_unlock(raw_spinlock_t *lock){	debug_spin_unlock(lock);	arch_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,		task_pid_nr(current), 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){	u64 i;	u64 loops = loops_per_jiffy * HZ;	int print_once = 1; 	for (;;) {		for (i = 0; i < loops; i++) {			if (arch_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 do_raw_read_lock(rwlock_t *lock){	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");	arch_read_lock(&lock->raw_lock);} int do_raw_read_trylock(rwlock_t *lock){	int ret = arch_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 do_raw_read_unlock(rwlock_t *lock){	RWLOCK_BUG_ON(lock->magic != RWLOCK_MAGIC, lock, "bad magic");	arch_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){	u64 i;	u64 loops = loops_per_jiffy * HZ;	int print_once = 1; 	for (;;) {		for (i = 0; i < loops; i++) {			if (arch_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 do_raw_write_lock(rwlock_t *lock){	debug_write_lock_before(lock);	arch_write_lock(&lock->raw_lock);	debug_write_lock_after(lock);} int do_raw_write_trylock(rwlock_t *lock){	int ret = arch_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 do_raw_write_unlock(rwlock_t *lock){	debug_write_unlock(lock);	arch_write_unlock(&lock->raw_lock);}