kernel/rtmutex-debug.c - kernel/msm-4.19 - Gitiles

 /*
  * RT-Mutexes: blocking mutual exclusion locks with PI support
  *
  * started by Ingo Molnar and Thomas Gleixner:
  *
  *  Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
  *  Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
  *
  * This code is based on the rt.c implementation in the preempt-rt tree.
  * Portions of said code are
  *
  *  Copyright (C) 2004  LynuxWorks, Inc., Igor Manyilov, Bill Huey
  *  Copyright (C) 2006  Esben Nielsen
  *  Copyright (C) 2006  Kihon Technologies Inc.,
  *			Steven Rostedt <rostedt@goodmis.org>
  *
  * See rt.c in preempt-rt for proper credits and further information
  */
 #include <linux/config.h>
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/kallsyms.h>
 #include <linux/syscalls.h>
 #include <linux/interrupt.h>
 #include <linux/plist.h>
 #include <linux/fs.h>

 #include "rtmutex_common.h"

 #ifdef CONFIG_DEBUG_RT_MUTEXES
 # include "rtmutex-debug.h"
 #else
 # include "rtmutex.h"
 #endif

 # define TRACE_WARN_ON(x)			WARN_ON(x)
 # define TRACE_BUG_ON(x)			BUG_ON(x)

 # define TRACE_OFF()						\
 do {								\
 	if (rt_trace_on) {					\
 		rt_trace_on = 0;				\
 		console_verbose();				\
 		if (spin_is_locked(&current->pi_lock))		\
 			spin_unlock(&current->pi_lock);		\
 		if (spin_is_locked(&current->held_list_lock))	\
 			spin_unlock(&current->held_list_lock);	\
 	}							\
 } while (0)

 # define TRACE_OFF_NOLOCK()					\
 do {								\
 	if (rt_trace_on) {					\
 		rt_trace_on = 0;				\
 		console_verbose();				\
 	}							\
 } while (0)

 # define TRACE_BUG_LOCKED()			\
 do {						\
 	TRACE_OFF();				\
 	BUG();					\
 } while (0)

 # define TRACE_WARN_ON_LOCKED(c)		\
 do {						\
 	if (unlikely(c)) {			\
 		TRACE_OFF();			\
 		WARN_ON(1);			\
 	}					\
 } while (0)

 # define TRACE_BUG_ON_LOCKED(c)			\
 do {						\
 	if (unlikely(c))			\
 		TRACE_BUG_LOCKED();		\
 } while (0)

 #ifdef CONFIG_SMP
 # define SMP_TRACE_BUG_ON_LOCKED(c)	TRACE_BUG_ON_LOCKED(c)
 #else
 # define SMP_TRACE_BUG_ON_LOCKED(c)	do { } while (0)
 #endif

 /*
  * deadlock detection flag. We turn it off when we detect
  * the first problem because we dont want to recurse back
  * into the tracing code when doing error printk or
  * executing a BUG():
  */
 int rt_trace_on = 1;

 void deadlock_trace_off(void)
 {
 	rt_trace_on = 0;
 }

 static void printk_task(task_t *p)
 {
 	if (p)
 		printk("%16s:%5d [%p, %3d]", p->comm, p->pid, p, p->prio);
 	else
 		printk("<none>");
 }

 static void printk_task_short(task_t *p)
 {
 	if (p)
 		printk("%s/%d [%p, %3d]", p->comm, p->pid, p, p->prio);
 	else
 		printk("<none>");
 }

 static void printk_lock(struct rt_mutex *lock, int print_owner)
 {
 	if (lock->name)
 		printk(" [%p] {%s}\n",
 			lock, lock->name);
 	else
 		printk(" [%p] {%s:%d}\n",
 			lock, lock->file, lock->line);

 	if (print_owner && rt_mutex_owner(lock)) {
 		printk(".. ->owner: %p\n", lock->owner);
 		printk(".. held by:  ");
 		printk_task(rt_mutex_owner(lock));
 		printk("\n");
 	}
 	if (rt_mutex_owner(lock)) {
 		printk("... acquired at:               ");
 		print_symbol("%s\n", lock->acquire_ip);
 	}
 }

 static void printk_waiter(struct rt_mutex_waiter *w)
 {
 	printk("-------------------------\n");
 	printk("| waiter struct %p:\n", w);
 	printk("| w->list_entry: [DP:%p/%p|SP:%p/%p|PRI:%d]\n",
 	       w->list_entry.plist.prio_list.prev, w->list_entry.plist.prio_list.next,
 	       w->list_entry.plist.node_list.prev, w->list_entry.plist.node_list.next,
 	       w->list_entry.prio);
 	printk("| w->pi_list_entry: [DP:%p/%p|SP:%p/%p|PRI:%d]\n",
 	       w->pi_list_entry.plist.prio_list.prev, w->pi_list_entry.plist.prio_list.next,
 	       w->pi_list_entry.plist.node_list.prev, w->pi_list_entry.plist.node_list.next,
 	       w->pi_list_entry.prio);
 	printk("\n| lock:\n");
 	printk_lock(w->lock, 1);
 	printk("| w->ti->task:\n");
 	printk_task(w->task);
 	printk("| blocked at:  ");
 	print_symbol("%s\n", w->ip);
 	printk("-------------------------\n");
 }

 static void show_task_locks(task_t *p)
 {
 	switch (p->state) {
 	case TASK_RUNNING:		printk("R"); break;
 	case TASK_INTERRUPTIBLE:	printk("S"); break;
 	case TASK_UNINTERRUPTIBLE:	printk("D"); break;
 	case TASK_STOPPED:		printk("T"); break;
 	case EXIT_ZOMBIE:		printk("Z"); break;
 	case EXIT_DEAD:			printk("X"); break;
 	default:			printk("?"); break;
 	}
 	printk_task(p);
 	if (p->pi_blocked_on) {
 		struct rt_mutex *lock = p->pi_blocked_on->lock;

 		printk(" blocked on:");
 		printk_lock(lock, 1);
 	} else
 		printk(" (not blocked)\n");
 }

 void rt_mutex_show_held_locks(task_t *task, int verbose)
 {
 	struct list_head *curr, *cursor = NULL;
 	struct rt_mutex *lock;
 	task_t *t;
 	unsigned long flags;
 	int count = 0;

 	if (!rt_trace_on)
 		return;

 	if (verbose) {
 		printk("------------------------------\n");
 		printk("| showing all locks held by: |  (");
 		printk_task_short(task);
 		printk("):\n");
 		printk("------------------------------\n");
 	}

 next:
 	spin_lock_irqsave(&task->held_list_lock, flags);
 	list_for_each(curr, &task->held_list_head) {
 		if (cursor && curr != cursor)
 			continue;
 		lock = list_entry(curr, struct rt_mutex, held_list_entry);
 		t = rt_mutex_owner(lock);
 		WARN_ON(t != task);
 		count++;
 		cursor = curr->next;
 		spin_unlock_irqrestore(&task->held_list_lock, flags);

 		printk("\n#%03d:            ", count);
 		printk_lock(lock, 0);
 		goto next;
 	}
 	spin_unlock_irqrestore(&task->held_list_lock, flags);

 	printk("\n");
 }

 void rt_mutex_show_all_locks(void)
 {
 	task_t *g, *p;
 	int count = 10;
 	int unlock = 1;

 	printk("\n");
 	printk("----------------------\n");
 	printk("| showing all tasks: |\n");
 	printk("----------------------\n");

 	/*
 	 * Here we try to get the tasklist_lock as hard as possible,
 	 * if not successful after 2 seconds we ignore it (but keep
 	 * trying). This is to enable a debug printout even if a
 	 * tasklist_lock-holding task deadlocks or crashes.
 	 */
 retry:
 	if (!read_trylock(&tasklist_lock)) {
 		if (count == 10)
 			printk("hm, tasklist_lock locked, retrying... ");
 		if (count) {
 			count--;
 			printk(" #%d", 10-count);
 			mdelay(200);
 			goto retry;
 		}
 		printk(" ignoring it.\n");
 		unlock = 0;
 	}
 	if (count != 10)
 		printk(" locked it.\n");

 	do_each_thread(g, p) {
 		show_task_locks(p);
 		if (!unlock)
 			if (read_trylock(&tasklist_lock))
 				unlock = 1;
 	} while_each_thread(g, p);

 	printk("\n");

 	printk("-----------------------------------------\n");
 	printk("| showing all locks held in the system: |\n");
 	printk("-----------------------------------------\n");

 	do_each_thread(g, p) {
 		rt_mutex_show_held_locks(p, 0);
 		if (!unlock)
 			if (read_trylock(&tasklist_lock))
 				unlock = 1;
 	} while_each_thread(g, p);


 	printk("=============================================\n\n");

 	if (unlock)
 		read_unlock(&tasklist_lock);
 }

 void rt_mutex_debug_check_no_locks_held(task_t *task)
 {
 	struct rt_mutex_waiter *w;
 	struct list_head *curr;
 	struct rt_mutex *lock;

 	if (!rt_trace_on)
 		return;
 	if (!rt_prio(task->normal_prio) && rt_prio(task->prio)) {
 		printk("BUG: PI priority boost leaked!\n");
 		printk_task(task);
 		printk("\n");
 	}
 	if (list_empty(&task->held_list_head))
 		return;

 	spin_lock(&task->pi_lock);
 	plist_for_each_entry(w, &task->pi_waiters, pi_list_entry) {
 		TRACE_OFF();

 		printk("hm, PI interest held at exit time? Task:\n");
 		printk_task(task);
 		printk_waiter(w);
 		return;
 	}
 	spin_unlock(&task->pi_lock);

 	list_for_each(curr, &task->held_list_head) {
 		lock = list_entry(curr, struct rt_mutex, held_list_entry);

 		printk("BUG: %s/%d, lock held at task exit time!\n",
 		       task->comm, task->pid);
 		printk_lock(lock, 1);
 		if (rt_mutex_owner(lock) != task)
 			printk("exiting task is not even the owner??\n");
 	}
 }

 int rt_mutex_debug_check_no_locks_freed(const void *from, unsigned long len)
 {
 	const void *to = from + len;
 	struct list_head *curr;
 	struct rt_mutex *lock;
 	unsigned long flags;
 	void *lock_addr;

 	if (!rt_trace_on)
 		return 0;

 	spin_lock_irqsave(&current->held_list_lock, flags);
 	list_for_each(curr, &current->held_list_head) {
 		lock = list_entry(curr, struct rt_mutex, held_list_entry);
 		lock_addr = lock;
 		if (lock_addr < from || lock_addr >= to)
 			continue;
 		TRACE_OFF();

 		printk("BUG: %s/%d, active lock [%p(%p-%p)] freed!\n",
 			current->comm, current->pid, lock, from, to);
 		dump_stack();
 		printk_lock(lock, 1);
 		if (rt_mutex_owner(lock) != current)
 			printk("freeing task is not even the owner??\n");
 		return 1;
 	}
 	spin_unlock_irqrestore(&current->held_list_lock, flags);

 	return 0;
 }

 void rt_mutex_debug_task_free(struct task_struct *task)
 {
 	WARN_ON(!plist_head_empty(&task->pi_waiters));
 	WARN_ON(task->pi_blocked_on);
 }

 /*
  * We fill out the fields in the waiter to store the information about
  * the deadlock. We print when we return. act_waiter can be NULL in
  * case of a remove waiter operation.
  */
 void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *act_waiter,
 			     struct rt_mutex *lock)
 {
 	struct task_struct *task;

 	if (!rt_trace_on || detect || !act_waiter)
 		return;

 	task = rt_mutex_owner(act_waiter->lock);
 	if (task && task != current) {
 		act_waiter->deadlock_task_pid = task->pid;
 		act_waiter->deadlock_lock = lock;
 	}
 }

 void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
 {
 	struct task_struct *task;

 	if (!waiter->deadlock_lock || !rt_trace_on)
 		return;

 	task = find_task_by_pid(waiter->deadlock_task_pid);
 	if (!task)
 		return;

 	TRACE_OFF_NOLOCK();

 	printk("\n============================================\n");
 	printk(  "[ BUG: circular locking deadlock detected! ]\n");
 	printk(  "--------------------------------------------\n");
 	printk("%s/%d is deadlocking current task %s/%d\n\n",
 	       task->comm, task->pid, current->comm, current->pid);

 	printk("\n1) %s/%d is trying to acquire this lock:\n",
 	       current->comm, current->pid);
 	printk_lock(waiter->lock, 1);

 	printk("... trying at:                 ");
 	print_symbol("%s\n", waiter->ip);

 	printk("\n2) %s/%d is blocked on this lock:\n", task->comm, task->pid);
 	printk_lock(waiter->deadlock_lock, 1);

 	rt_mutex_show_held_locks(current, 1);
 	rt_mutex_show_held_locks(task, 1);

 	printk("\n%s/%d's [blocked] stackdump:\n\n", task->comm, task->pid);
 	show_stack(task, NULL);
 	printk("\n%s/%d's [current] stackdump:\n\n",
 	       current->comm, current->pid);
 	dump_stack();
 	rt_mutex_show_all_locks();
 	printk("[ turning off deadlock detection."
 	       "Please report this trace. ]\n\n");
 	local_irq_disable();
 }

 void debug_rt_mutex_lock(struct rt_mutex *lock __IP_DECL__)
 {
 	unsigned long flags;

 	if (rt_trace_on) {
 		TRACE_WARN_ON_LOCKED(!list_empty(&lock->held_list_entry));

 		spin_lock_irqsave(&current->held_list_lock, flags);
 		list_add_tail(&lock->held_list_entry, &current->held_list_head);
 		spin_unlock_irqrestore(&current->held_list_lock, flags);

 		lock->acquire_ip = ip;
 	}
 }

 void debug_rt_mutex_unlock(struct rt_mutex *lock)
 {
 	unsigned long flags;

 	if (rt_trace_on) {
 		TRACE_WARN_ON_LOCKED(rt_mutex_owner(lock) != current);
 		TRACE_WARN_ON_LOCKED(list_empty(&lock->held_list_entry));

 		spin_lock_irqsave(&current->held_list_lock, flags);
 		list_del_init(&lock->held_list_entry);
 		spin_unlock_irqrestore(&current->held_list_lock, flags);
 	}
 }

 void debug_rt_mutex_proxy_lock(struct rt_mutex *lock,
 			       struct task_struct *powner __IP_DECL__)
 {
 	unsigned long flags;

 	if (rt_trace_on) {
 		TRACE_WARN_ON_LOCKED(!list_empty(&lock->held_list_entry));

 		spin_lock_irqsave(&powner->held_list_lock, flags);
 		list_add_tail(&lock->held_list_entry, &powner->held_list_head);
 		spin_unlock_irqrestore(&powner->held_list_lock, flags);

 		lock->acquire_ip = ip;
 	}
 }

 void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
 {
 	unsigned long flags;

 	if (rt_trace_on) {
 		struct task_struct *owner = rt_mutex_owner(lock);

 		TRACE_WARN_ON_LOCKED(!owner);
 		TRACE_WARN_ON_LOCKED(list_empty(&lock->held_list_entry));

 		spin_lock_irqsave(&owner->held_list_lock, flags);
 		list_del_init(&lock->held_list_entry);
 		spin_unlock_irqrestore(&owner->held_list_lock, flags);
 	}
 }

 void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
 {
 	memset(waiter, 0x11, sizeof(*waiter));
 	plist_node_init(&waiter->list_entry, MAX_PRIO);
 	plist_node_init(&waiter->pi_list_entry, MAX_PRIO);
 }

 void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
 {
 	TRACE_WARN_ON(!plist_node_empty(&waiter->list_entry));
 	TRACE_WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
 	TRACE_WARN_ON(waiter->task);
 	memset(waiter, 0x22, sizeof(*waiter));
 }

 void debug_rt_mutex_init(struct rt_mutex *lock, const char *name)
 {
 	void *addr = lock;

 	if (rt_trace_on) {
 		rt_mutex_debug_check_no_locks_freed(addr,
 						    sizeof(struct rt_mutex));
 		INIT_LIST_HEAD(&lock->held_list_entry);
 		lock->name = name;
 	}
 }

 void rt_mutex_deadlock_account_lock(struct rt_mutex *lock, task_t *task)
 {
 }

 void rt_mutex_deadlock_account_unlock(struct task_struct *task)
 {
 }
	/*
	* RT-Mutexes: blocking mutual exclusion locks with PI support
	*
	* started by Ingo Molnar and Thomas Gleixner:
	*
	* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
	* Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
	*
	* This code is based on the rt.c implementation in the preempt-rt tree.
	* Portions of said code are
	*
	* Copyright (C) 2004 LynuxWorks, Inc., Igor Manyilov, Bill Huey
	* Copyright (C) 2006 Esben Nielsen
	* Copyright (C) 2006 Kihon Technologies Inc.,
	* Steven Rostedt <rostedt@goodmis.org>
	*
	* See rt.c in preempt-rt for proper credits and further information
	*/
	#include <linux/config.h>
	#include <linux/sched.h>
	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/spinlock.h>
	#include <linux/kallsyms.h>
	#include <linux/syscalls.h>
	#include <linux/interrupt.h>
	#include <linux/plist.h>
	#include <linux/fs.h>

	#include "rtmutex_common.h"

	#ifdef CONFIG_DEBUG_RT_MUTEXES
	# include "rtmutex-debug.h"
	#else
	# include "rtmutex.h"
	#endif

	# define TRACE_WARN_ON(x) WARN_ON(x)
	# define TRACE_BUG_ON(x) BUG_ON(x)

	# define TRACE_OFF() \
	do { \
	if (rt_trace_on) { \
	rt_trace_on = 0; \
	console_verbose(); \
	if (spin_is_locked(&current->pi_lock)) \
	spin_unlock(&current->pi_lock); \
	if (spin_is_locked(&current->held_list_lock)) \
	spin_unlock(&current->held_list_lock); \
	} \
	} while (0)

	# define TRACE_OFF_NOLOCK() \
	do { \
	if (rt_trace_on) { \
	rt_trace_on = 0; \
	console_verbose(); \
	} \
	} while (0)

	# define TRACE_BUG_LOCKED() \
	do { \
	TRACE_OFF(); \
	BUG(); \
	} while (0)

	# define TRACE_WARN_ON_LOCKED(c) \
	do { \
	if (unlikely(c)) { \
	TRACE_OFF(); \
	WARN_ON(1); \
	} \
	} while (0)

	# define TRACE_BUG_ON_LOCKED(c) \
	do { \
	if (unlikely(c)) \
	TRACE_BUG_LOCKED(); \
	} while (0)

	#ifdef CONFIG_SMP
	# define SMP_TRACE_BUG_ON_LOCKED(c) TRACE_BUG_ON_LOCKED(c)
	#else
	# define SMP_TRACE_BUG_ON_LOCKED(c) do { } while (0)
	#endif

	/*
	* deadlock detection flag. We turn it off when we detect
	* the first problem because we dont want to recurse back
	* into the tracing code when doing error printk or
	* executing a BUG():
	*/
	int rt_trace_on = 1;

	void deadlock_trace_off(void)
	{
	rt_trace_on = 0;
	}

	static void printk_task(task_t *p)
	{
	if (p)
	printk("%16s:%5d [%p, %3d]", p->comm, p->pid, p, p->prio);
	else
	printk("<none>");
	}

	static void printk_task_short(task_t *p)
	{
	if (p)
	printk("%s/%d [%p, %3d]", p->comm, p->pid, p, p->prio);
	else
	printk("<none>");
	}

	static void printk_lock(struct rt_mutex *lock, int print_owner)
	{
	if (lock->name)
	printk(" [%p] {%s}\n",
	lock, lock->name);
	else
	printk(" [%p] {%s:%d}\n",
	lock, lock->file, lock->line);

	if (print_owner && rt_mutex_owner(lock)) {
	printk(".. ->owner: %p\n", lock->owner);
	printk(".. held by: ");
	printk_task(rt_mutex_owner(lock));
	printk("\n");
	}
	if (rt_mutex_owner(lock)) {
	printk("... acquired at: ");
	print_symbol("%s\n", lock->acquire_ip);
	}
	}

	static void printk_waiter(struct rt_mutex_waiter *w)
	{
	printk("-------------------------\n");
	printk("\| waiter struct %p:\n", w);
	printk("\| w->list_entry: [DP:%p/%p\|SP:%p/%p\|PRI:%d]\n",
	w->list_entry.plist.prio_list.prev, w->list_entry.plist.prio_list.next,
	w->list_entry.plist.node_list.prev, w->list_entry.plist.node_list.next,
	w->list_entry.prio);
	printk("\| w->pi_list_entry: [DP:%p/%p\|SP:%p/%p\|PRI:%d]\n",
	w->pi_list_entry.plist.prio_list.prev, w->pi_list_entry.plist.prio_list.next,
	w->pi_list_entry.plist.node_list.prev, w->pi_list_entry.plist.node_list.next,
	w->pi_list_entry.prio);
	printk("\n\| lock:\n");
	printk_lock(w->lock, 1);
	printk("\| w->ti->task:\n");
	printk_task(w->task);
	printk("\| blocked at: ");
	print_symbol("%s\n", w->ip);
	printk("-------------------------\n");
	}

	static void show_task_locks(task_t *p)
	{
	switch (p->state) {
	case TASK_RUNNING: printk("R"); break;
	case TASK_INTERRUPTIBLE: printk("S"); break;
	case TASK_UNINTERRUPTIBLE: printk("D"); break;
	case TASK_STOPPED: printk("T"); break;
	case EXIT_ZOMBIE: printk("Z"); break;
	case EXIT_DEAD: printk("X"); break;
	default: printk("?"); break;
	}
	printk_task(p);
	if (p->pi_blocked_on) {
	struct rt_mutex *lock = p->pi_blocked_on->lock;

	printk(" blocked on:");
	printk_lock(lock, 1);
	} else
	printk(" (not blocked)\n");
	}

	void rt_mutex_show_held_locks(task_t *task, int verbose)
	{
	struct list_head curr, cursor = NULL;
	struct rt_mutex *lock;
	task_t *t;
	unsigned long flags;
	int count = 0;

	if (!rt_trace_on)
	return;

	if (verbose) {
	printk("------------------------------\n");
	printk("\| showing all locks held by: \| (");
	printk_task_short(task);
	printk("):\n");
	printk("------------------------------\n");
	}

	next:
	spin_lock_irqsave(&task->held_list_lock, flags);
	list_for_each(curr, &task->held_list_head) {
	if (cursor && curr != cursor)
	continue;
	lock = list_entry(curr, struct rt_mutex, held_list_entry);
	t = rt_mutex_owner(lock);
	WARN_ON(t != task);
	count++;
	cursor = curr->next;
	spin_unlock_irqrestore(&task->held_list_lock, flags);

	printk("\n#%03d: ", count);
	printk_lock(lock, 0);
	goto next;
	}
	spin_unlock_irqrestore(&task->held_list_lock, flags);

	printk("\n");
	}

	void rt_mutex_show_all_locks(void)
	{
	task_t g, p;
	int count = 10;
	int unlock = 1;

	printk("\n");
	printk("----------------------\n");
	printk("\| showing all tasks: \|\n");
	printk("----------------------\n");

	/*
	* Here we try to get the tasklist_lock as hard as possible,
	* if not successful after 2 seconds we ignore it (but keep
	* trying). This is to enable a debug printout even if a
	* tasklist_lock-holding task deadlocks or crashes.
	*/
	retry:
	if (!read_trylock(&tasklist_lock)) {
	if (count == 10)
	printk("hm, tasklist_lock locked, retrying... ");
	if (count) {
	count--;
	printk(" #%d", 10-count);
	mdelay(200);
	goto retry;
	}
	printk(" ignoring it.\n");
	unlock = 0;
	}
	if (count != 10)
	printk(" locked it.\n");

	do_each_thread(g, p) {
	show_task_locks(p);
	if (!unlock)
	if (read_trylock(&tasklist_lock))
	unlock = 1;
	} while_each_thread(g, p);

	printk("\n");

	printk("-----------------------------------------\n");
	printk("\| showing all locks held in the system: \|\n");
	printk("-----------------------------------------\n");

	do_each_thread(g, p) {
	rt_mutex_show_held_locks(p, 0);
	if (!unlock)
	if (read_trylock(&tasklist_lock))
	unlock = 1;
	} while_each_thread(g, p);


	printk("=============================================\n\n");

	if (unlock)
	read_unlock(&tasklist_lock);
	}

	void rt_mutex_debug_check_no_locks_held(task_t *task)
	{
	struct rt_mutex_waiter *w;
	struct list_head *curr;
	struct rt_mutex *lock;

	if (!rt_trace_on)
	return;
	if (!rt_prio(task->normal_prio) && rt_prio(task->prio)) {
	printk("BUG: PI priority boost leaked!\n");
	printk_task(task);
	printk("\n");
	}
	if (list_empty(&task->held_list_head))
	return;

	spin_lock(&task->pi_lock);
	plist_for_each_entry(w, &task->pi_waiters, pi_list_entry) {
	TRACE_OFF();

	printk("hm, PI interest held at exit time? Task:\n");
	printk_task(task);
	printk_waiter(w);
	return;
	}
	spin_unlock(&task->pi_lock);

	list_for_each(curr, &task->held_list_head) {
	lock = list_entry(curr, struct rt_mutex, held_list_entry);

	printk("BUG: %s/%d, lock held at task exit time!\n",
	task->comm, task->pid);
	printk_lock(lock, 1);
	if (rt_mutex_owner(lock) != task)
	printk("exiting task is not even the owner??\n");
	}
	}

	int rt_mutex_debug_check_no_locks_freed(const void *from, unsigned long len)
	{
	const void *to = from + len;
	struct list_head *curr;
	struct rt_mutex *lock;
	unsigned long flags;
	void *lock_addr;

	if (!rt_trace_on)
	return 0;

	spin_lock_irqsave(&current->held_list_lock, flags);
	list_for_each(curr, &current->held_list_head) {
	lock = list_entry(curr, struct rt_mutex, held_list_entry);
	lock_addr = lock;
	if (lock_addr < from \|\| lock_addr >= to)
	continue;
	TRACE_OFF();

	printk("BUG: %s/%d, active lock [%p(%p-%p)] freed!\n",
	current->comm, current->pid, lock, from, to);
	dump_stack();
	printk_lock(lock, 1);
	if (rt_mutex_owner(lock) != current)
	printk("freeing task is not even the owner??\n");
	return 1;
	}
	spin_unlock_irqrestore(&current->held_list_lock, flags);

	return 0;
	}

	void rt_mutex_debug_task_free(struct task_struct *task)
	{
	WARN_ON(!plist_head_empty(&task->pi_waiters));
	WARN_ON(task->pi_blocked_on);
	}

	/*
	* We fill out the fields in the waiter to store the information about
	* the deadlock. We print when we return. act_waiter can be NULL in
	* case of a remove waiter operation.
	*/
	void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *act_waiter,
	struct rt_mutex *lock)
	{
	struct task_struct *task;

	if (!rt_trace_on \|\| detect \|\| !act_waiter)
	return;

	task = rt_mutex_owner(act_waiter->lock);
	if (task && task != current) {
	act_waiter->deadlock_task_pid = task->pid;
	act_waiter->deadlock_lock = lock;
	}
	}

	void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
	{
	struct task_struct *task;

	if (!waiter->deadlock_lock \|\| !rt_trace_on)
	return;

	task = find_task_by_pid(waiter->deadlock_task_pid);
	if (!task)
	return;

	TRACE_OFF_NOLOCK();

	printk("\n============================================\n");
	printk( "[ BUG: circular locking deadlock detected! ]\n");
	printk( "--------------------------------------------\n");
	printk("%s/%d is deadlocking current task %s/%d\n\n",
	task->comm, task->pid, current->comm, current->pid);

	printk("\n1) %s/%d is trying to acquire this lock:\n",
	current->comm, current->pid);
	printk_lock(waiter->lock, 1);

	printk("... trying at: ");
	print_symbol("%s\n", waiter->ip);

	printk("\n2) %s/%d is blocked on this lock:\n", task->comm, task->pid);
	printk_lock(waiter->deadlock_lock, 1);

	rt_mutex_show_held_locks(current, 1);
	rt_mutex_show_held_locks(task, 1);

	printk("\n%s/%d's [blocked] stackdump:\n\n", task->comm, task->pid);
	show_stack(task, NULL);
	printk("\n%s/%d's [current] stackdump:\n\n",
	current->comm, current->pid);
	dump_stack();
	rt_mutex_show_all_locks();
	printk("[ turning off deadlock detection."
	"Please report this trace. ]\n\n");
	local_irq_disable();
	}

	void debug_rt_mutex_lock(struct rt_mutex *lock __IP_DECL__)
	{
	unsigned long flags;

	if (rt_trace_on) {
	TRACE_WARN_ON_LOCKED(!list_empty(&lock->held_list_entry));

	spin_lock_irqsave(&current->held_list_lock, flags);
	list_add_tail(&lock->held_list_entry, &current->held_list_head);
	spin_unlock_irqrestore(&current->held_list_lock, flags);

	lock->acquire_ip = ip;
	}
	}

	void debug_rt_mutex_unlock(struct rt_mutex *lock)
	{
	unsigned long flags;

	if (rt_trace_on) {
	TRACE_WARN_ON_LOCKED(rt_mutex_owner(lock) != current);
	TRACE_WARN_ON_LOCKED(list_empty(&lock->held_list_entry));

	spin_lock_irqsave(&current->held_list_lock, flags);
	list_del_init(&lock->held_list_entry);
	spin_unlock_irqrestore(&current->held_list_lock, flags);
	}
	}

	void debug_rt_mutex_proxy_lock(struct rt_mutex *lock,
	struct task_struct *powner __IP_DECL__)
	{
	unsigned long flags;

	if (rt_trace_on) {
	TRACE_WARN_ON_LOCKED(!list_empty(&lock->held_list_entry));

	spin_lock_irqsave(&powner->held_list_lock, flags);
	list_add_tail(&lock->held_list_entry, &powner->held_list_head);
	spin_unlock_irqrestore(&powner->held_list_lock, flags);

	lock->acquire_ip = ip;
	}
	}

	void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
	{
	unsigned long flags;

	if (rt_trace_on) {
	struct task_struct *owner = rt_mutex_owner(lock);

	TRACE_WARN_ON_LOCKED(!owner);
	TRACE_WARN_ON_LOCKED(list_empty(&lock->held_list_entry));

	spin_lock_irqsave(&owner->held_list_lock, flags);
	list_del_init(&lock->held_list_entry);
	spin_unlock_irqrestore(&owner->held_list_lock, flags);
	}
	}

	void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
	{
	memset(waiter, 0x11, sizeof(*waiter));
	plist_node_init(&waiter->list_entry, MAX_PRIO);
	plist_node_init(&waiter->pi_list_entry, MAX_PRIO);
	}

	void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
	{
	TRACE_WARN_ON(!plist_node_empty(&waiter->list_entry));
	TRACE_WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
	TRACE_WARN_ON(waiter->task);
	memset(waiter, 0x22, sizeof(*waiter));
	}

	void debug_rt_mutex_init(struct rt_mutex lock, const char name)
	{
	void *addr = lock;

	if (rt_trace_on) {
	rt_mutex_debug_check_no_locks_freed(addr,
	sizeof(struct rt_mutex));
	INIT_LIST_HEAD(&lock->held_list_entry);
	lock->name = name;
	}
	}

	void rt_mutex_deadlock_account_lock(struct rt_mutex lock, task_t task)
	{
	}

	void rt_mutex_deadlock_account_unlock(struct task_struct *task)
	{
	}