rtmutex-debug.c

/*
 * 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/sched.h>
#include <linux/delay.h>
#include <linux/export.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 <linux/debug_locks.h>

#include "rtmutex_common.h"

static void printk_task(struct task_struct *p)
{
	if (p)
		printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), 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");
	}
}

void rt_mutex_debug_task_free(struct task_struct *task)
{
	DEBUG_LOCKS_WARN_ON(!plist_head_empty(&task->pi_waiters));
	DEBUG_LOCKS_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)
{