path: root/kernel/lockdep_proc.c

/*
 * kernel/lockdep_proc.c
 *
 * Runtime locking correctness validator
 *
 * Started by Ingo Molnar:
 *
 *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
 *
 * Code for /proc/lockdep and /proc/lockdep_stats:
 *
 */
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/debug_locks.h>
#include <linux/vmalloc.h>
#include <linux/sort.h>
#include <asm/uaccess.h>
#include <asm/div64.h>

#include "lockdep_internals.h"

static void *l_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct lock_class *class;

	(*pos)++;

	if (v == SEQ_START_TOKEN)
		class = m->private;
	else {
		class = v;

		if (class->lock_entry.next != &all_lock_classes)
			class = list_entry(class->lock_entry.next,
					   struct lock_class, lock_entry);
		else
			class = NULL;
	}

	return class;
}

static void *l_start(struct seq_file *m, loff_t *pos)
{
	struct lock_class *class;
	loff_t i = 0;

	if (*pos == 0)
		return SEQ_START_TOKEN;

	list_for_each_entry(class, &all_lock_classes, lock_entry) {
		if (++i == *pos)
		return class;
	}
	return NULL;
}

static void l_stop(struct seq_file *m, void *v)
{
}

static void print_name(struct seq_file *m, struct lock_class *class)
{
	char str[128];
	const char *name = class->name;

	if (!name) {
		name = __get_key_name(class->key, str);
		seq_printf(m, "%s", name);
	} else{
		seq_printf(m, "%s", name);
		if (class->name_version > 1)
			seq_printf(m, "#%d", class->name_version);
		if (class->subclass)
			seq_printf(m, "/%d", class->subclass);
	}
}

static int l_show(struct seq_file *m, void *v)
{
	struct lock_class *class = v;
	struct lock_list *entry;
	char usage[LOCK_USAGE_CHARS];

	if (v == SEQ_START_TOKEN) {
		seq_printf(m, "all lock classes:\n");
		return 0;
	}

	seq_printf(m, "%p", class->key);
#ifdef CONFIG_DEBUG_LOCKDEP
	seq_printf(m, " OPS:%8ld", class->ops);
#endif
#ifdef CONFIG_PROVE_LOCKING
	seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));
	seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
#endif

	get_usage_chars(class, usage);
	seq_printf(m, " %s", usage);

	seq_printf(m, ": ");
	print_name(m, class);
	seq_puts(m, "\n");

	list_for_each_entry(entry, &class->locks_after, entry) {
		if (entry->distance == 1) {
			seq_printf(m, " -> [%p] ", entry->class->key);
			print_name(m, entry->class);
			seq_puts(m, "\n");
		}
	}
	seq_puts(m, "\n");

	return 0;
}

static const struct seq_operations lockdep_ops = {
	.start	= l_start,
	.next	= l_next,
	.stop	= l_stop,
	.show	= l_show,
};

static int lockdep_open(struct inode *inode, struct file *file)
{
	int res = seq_open(file, &lockdep_ops);
	if (!res) {
		struct seq_file *m = file->private_data;

		if (!list_empty(&all_lock_classes))
			m->private = list_entry(all_lock_classes.next,
					struct lock_class, lock_entry);
		else
			m->private = NULL;
	}
	return res;
}

static const struct file_operations proc_lockdep_operations = {
	.open		= lockdep_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

#ifdef CONFIG_PROVE_LOCKING
static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct lock_chain *chain;

	(*pos)++;

	if (v == SEQ_START_TOKEN)
		chain = m->private;
	else {
		chain = v;

		if (*pos - 1 < nr_lock_chains)
			chain = lock_chains + (*pos - 1);
		else
			chain = NULL;
	}

	return chain;
}

static void *lc_start(struct seq_file *m, loff_t *pos)
{
	if (*pos == 0)
		return SEQ_START_TOKEN;

	if (*pos - 1 < nr_lock_chains)
		return lock_chains + (*pos - 1);

	return NULL;
}

static void lc_stop(struct seq_file *m, void *v)
{
}

static int lc_show(struct seq_file *m, void *v)
{
	struct lock_chain *chain = v;
	struct lock_class *class;
	int i;

	if (v == SEQ_START_TOKEN) {
		seq_printf(m,<