kernel/lockdep_proc.c - kernel/msm-4.19 - Gitiles

 /*
  * 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 unsigned long count_forward_deps(struct lock_class *class)
 {
 	struct lock_list *entry;
 	unsigned long ret = 1;

 	/*
 	 * Recurse this class's dependency list:
 	 */
 	list_for_each_entry(entry, &class->locks_after, entry)
 		ret += count_forward_deps(entry->class);

 	return ret;
 }

 static unsigned long count_backward_deps(struct lock_class *class)
 {
 	struct lock_list *entry;
 	unsigned long ret = 1;

 	/*
 	 * Recurse this class's dependency list:
 	 */
 	list_for_each_entry(entry, &class->locks_before, entry)
 		ret += count_backward_deps(entry->class);

 	return ret;
 }

 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)
 {
 	unsigned long nr_forward_deps, nr_backward_deps;
 	struct lock_class *class = v;
 	struct lock_list *entry;
 	char c1, c2, c3, c4;

 	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
 	nr_forward_deps = count_forward_deps(class);
 	seq_printf(m, " FD:%5ld", nr_forward_deps);

 	nr_backward_deps = count_backward_deps(class);
 	seq_printf(m, " BD:%5ld", nr_backward_deps);

 	get_usage_chars(class, &c1, &c2, &c3, &c4);
 	seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);

 	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 < nr_lock_chains)
 			chain = lock_chains + *pos;
 		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 < nr_lock_chains)
 		return lock_chains + *pos;

 	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, "all lock chains:\n");
 		return 0;
 	}

 	seq_printf(m, "irq_context: %d\n", chain->irq_context);

 	for (i = 0; i < chain->depth; i++) {
 		class = lock_chain_get_class(chain, i);
 		seq_printf(m, "[%p] ", class->key);
 		print_name(m, class);
 		seq_puts(m, "\n");
 	}
 	seq_puts(m, "\n");

 	return 0;
 }

 static const struct seq_operations lockdep_chains_ops = {
 	.start	= lc_start,
 	.next	= lc_next,
 	.stop	= lc_stop,
 	.show	= lc_show,
 };

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

 		if (nr_lock_chains)
 			m->private = lock_chains;
 		else
 			m->private = NULL;
 	}
 	return res;
 }

 static const struct file_operations proc_lockdep_chains_operations = {
 	.open		= lockdep_chains_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
 #endif /* CONFIG_PROVE_LOCKING */

 static void lockdep_stats_debug_show(struct seq_file *m)
 {
 #ifdef CONFIG_DEBUG_LOCKDEP
 	unsigned int hi1 = debug_atomic_read(&hardirqs_on_events),
 		     hi2 = debug_atomic_read(&hardirqs_off_events),
 		     hr1 = debug_atomic_read(&redundant_hardirqs_on),
 		     hr2 = debug_atomic_read(&redundant_hardirqs_off),
 		     si1 = debug_atomic_read(&softirqs_on_events),
 		     si2 = debug_atomic_read(&softirqs_off_events),
 		     sr1 = debug_atomic_read(&redundant_softirqs_on),
 		     sr2 = debug_atomic_read(&redundant_softirqs_off);

 	seq_printf(m, " chain lookup misses:           %11u\n",
 		debug_atomic_read(&chain_lookup_misses));
 	seq_printf(m, " chain lookup hits:             %11u\n",
 		debug_atomic_read(&chain_lookup_hits));
 	seq_printf(m, " cyclic checks:                 %11u\n",
 		debug_atomic_read(&nr_cyclic_checks));
 	seq_printf(m, " cyclic-check recursions:       %11u\n",
 		debug_atomic_read(&nr_cyclic_check_recursions));
 	seq_printf(m, " find-mask forwards checks:     %11u\n",
 		debug_atomic_read(&nr_find_usage_forwards_checks));
 	seq_printf(m, " find-mask forwards recursions: %11u\n",
 		debug_atomic_read(&nr_find_usage_forwards_recursions));
 	seq_printf(m, " find-mask backwards checks:    %11u\n",
 		debug_atomic_read(&nr_find_usage_backwards_checks));
 	seq_printf(m, " find-mask backwards recursions:%11u\n",
 		debug_atomic_read(&nr_find_usage_backwards_recursions));

 	seq_printf(m, " hardirq on events:             %11u\n", hi1);
 	seq_printf(m, " hardirq off events:            %11u\n", hi2);
 	seq_printf(m, " redundant hardirq ons:         %11u\n", hr1);
 	seq_printf(m, " redundant hardirq offs:        %11u\n", hr2);
 	seq_printf(m, " softirq on events:             %11u\n", si1);
 	seq_printf(m, " softirq off events:            %11u\n", si2);
 	seq_printf(m, " redundant softirq ons:         %11u\n", sr1);
 	seq_printf(m, " redundant softirq offs:        %11u\n", sr2);
 #endif
 }

 static int lockdep_stats_show(struct seq_file *m, void *v)
 {
 	struct lock_class *class;
 	unsigned long nr_unused = 0, nr_uncategorized = 0,
 		      nr_irq_safe = 0, nr_irq_unsafe = 0,
 		      nr_softirq_safe = 0, nr_softirq_unsafe = 0,
 		      nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
 		      nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
 		      nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
 		      nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
 		      sum_forward_deps = 0, factor = 0;

 	list_for_each_entry(class, &all_lock_classes, lock_entry) {

 		if (class->usage_mask == 0)
 			nr_unused++;
 		if (class->usage_mask == LOCKF_USED)
 			nr_uncategorized++;
 		if (class->usage_mask & LOCKF_USED_IN_IRQ)
 			nr_irq_safe++;
 		if (class->usage_mask & LOCKF_ENABLED_IRQS)
 			nr_irq_unsafe++;
 		if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
 			nr_softirq_safe++;
 		if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
 			nr_softirq_unsafe++;
 		if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
 			nr_hardirq_safe++;
 		if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
 			nr_hardirq_unsafe++;
 		if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
 			nr_irq_read_safe++;
 		if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
 			nr_irq_read_unsafe++;
 		if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
 			nr_softirq_read_safe++;
 		if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
 			nr_softirq_read_unsafe++;
 		if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
 			nr_hardirq_read_safe++;
 		if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
 			nr_hardirq_read_unsafe++;

 		sum_forward_deps += count_forward_deps(class);
 	}
 #ifdef CONFIG_DEBUG_LOCKDEP
 	DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
 #endif
 	seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",
 			nr_lock_classes, MAX_LOCKDEP_KEYS);
 	seq_printf(m, " direct dependencies:           %11lu [max: %lu]\n",
 			nr_list_entries, MAX_LOCKDEP_ENTRIES);
 	seq_printf(m, " indirect dependencies:         %11lu\n",
 			sum_forward_deps);

 	/*
 	 * Total number of dependencies:
 	 *
 	 * All irq-safe locks may nest inside irq-unsafe locks,
 	 * plus all the other known dependencies:
 	 */
 	seq_printf(m, " all direct dependencies:       %11lu\n",
 			nr_irq_unsafe * nr_irq_safe +
 			nr_hardirq_unsafe * nr_hardirq_safe +
 			nr_list_entries);

 	/*
 	 * Estimated factor between direct and indirect
 	 * dependencies:
 	 */
 	if (nr_list_entries)
 		factor = sum_forward_deps / nr_list_entries;

 #ifdef CONFIG_PROVE_LOCKING
 	seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
 			nr_lock_chains, MAX_LOCKDEP_CHAINS);
 	seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",
 			nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
 #endif

 #ifdef CONFIG_TRACE_IRQFLAGS
 	seq_printf(m, " in-hardirq chains:             %11u\n",
 			nr_hardirq_chains);
 	seq_printf(m, " in-softirq chains:             %11u\n",
 			nr_softirq_chains);
 #endif
 	seq_printf(m, " in-process chains:             %11u\n",
 			nr_process_chains);
 	seq_printf(m, " stack-trace entries:           %11lu [max: %lu]\n",
 			nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
 	seq_printf(m, " combined max dependencies:     %11u\n",
 			(nr_hardirq_chains + 1) *
 			(nr_softirq_chains + 1) *
 			(nr_process_chains + 1)
 	);
 	seq_printf(m, " hardirq-safe locks:            %11lu\n",
 			nr_hardirq_safe);
 	seq_printf(m, " hardirq-unsafe locks:          %11lu\n",
 			nr_hardirq_unsafe);
 	seq_printf(m, " softirq-safe locks:            %11lu\n",
 			nr_softirq_safe);
 	seq_printf(m, " softirq-unsafe locks:          %11lu\n",
 			nr_softirq_unsafe);
 	seq_printf(m, " irq-safe locks:                %11lu\n",
 			nr_irq_safe);
 	seq_printf(m, " irq-unsafe locks:              %11lu\n",
 			nr_irq_unsafe);

 	seq_printf(m, " hardirq-read-safe locks:       %11lu\n",
 			nr_hardirq_read_safe);
 	seq_printf(m, " hardirq-read-unsafe locks:     %11lu\n",
 			nr_hardirq_read_unsafe);
 	seq_printf(m, " softirq-read-safe locks:       %11lu\n",
 			nr_softirq_read_safe);
 	seq_printf(m, " softirq-read-unsafe locks:     %11lu\n",
 			nr_softirq_read_unsafe);
 	seq_printf(m, " irq-read-safe locks:           %11lu\n",
 			nr_irq_read_safe);
 	seq_printf(m, " irq-read-unsafe locks:         %11lu\n",
 			nr_irq_read_unsafe);

 	seq_printf(m, " uncategorized locks:           %11lu\n",
 			nr_uncategorized);
 	seq_printf(m, " unused locks:                  %11lu\n",
 			nr_unused);
 	seq_printf(m, " max locking depth:             %11u\n",
 			max_lockdep_depth);
 	seq_printf(m, " max recursion depth:           %11u\n",
 			max_recursion_depth);
 	lockdep_stats_debug_show(m);
 	seq_printf(m, " debug_locks:                   %11u\n",
 			debug_locks);

 	return 0;
 }

 static int lockdep_stats_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, lockdep_stats_show, NULL);
 }

 static const struct file_operations proc_lockdep_stats_operations = {
 	.open		= lockdep_stats_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 #ifdef CONFIG_LOCK_STAT

 struct lock_stat_data {
 	struct lock_class *class;
 	struct lock_class_stats stats;
 };

 struct lock_stat_seq {
 	struct lock_stat_data *iter;
 	struct lock_stat_data *iter_end;
 	struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
 };

 /*
  * sort on absolute number of contentions
  */
 static int lock_stat_cmp(const void *l, const void *r)
 {
 	const struct lock_stat_data *dl = l, *dr = r;
 	unsigned long nl, nr;

 	nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
 	nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;

 	return nr - nl;
 }

 static void seq_line(struct seq_file *m, char c, int offset, int length)
 {
 	int i;

 	for (i = 0; i < offset; i++)
 		seq_puts(m, " ");
 	for (i = 0; i < length; i++)
 		seq_printf(m, "%c", c);
 	seq_puts(m, "\n");
 }

 static void snprint_time(char *buf, size_t bufsiz, s64 nr)
 {
 	unsigned long rem;

 	rem = do_div(nr, 1000); /* XXX: do_div_signed */
 	snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, ((int)rem+5)/10);
 }

 static void seq_time(struct seq_file *m, s64 time)
 {
 	char num[15];

 	snprint_time(num, sizeof(num), time);
 	seq_printf(m, " %14s", num);
 }

 static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
 {
 	seq_printf(m, "%14lu", lt->nr);
 	seq_time(m, lt->min);
 	seq_time(m, lt->max);
 	seq_time(m, lt->total);
 }

 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
 {
 	char name[39];
 	struct lock_class *class;
 	struct lock_class_stats *stats;
 	int i, namelen;

 	class = data->class;
 	stats = &data->stats;

 	namelen = 38;
 	if (class->name_version > 1)
 		namelen -= 2; /* XXX truncates versions > 9 */
 	if (class->subclass)
 		namelen -= 2;

 	if (!class->name) {
 		char str[KSYM_NAME_LEN];
 		const char *key_name;

 		key_name = __get_key_name(class->key, str);
 		snprintf(name, namelen, "%s", key_name);
 	} else {
 		snprintf(name, namelen, "%s", class->name);
 	}
 	namelen = strlen(name);
 	if (class->name_version > 1) {
 		snprintf(name+namelen, 3, "#%d", class->name_version);
 		namelen += 2;
 	}
 	if (class->subclass) {
 		snprintf(name+namelen, 3, "/%d", class->subclass);
 		namelen += 2;
 	}

 	if (stats->write_holdtime.nr) {
 		if (stats->read_holdtime.nr)
 			seq_printf(m, "%38s-W:", name);
 		else
 			seq_printf(m, "%40s:", name);

 		seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
 		seq_lock_time(m, &stats->write_waittime);
 		seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
 		seq_lock_time(m, &stats->write_holdtime);
 		seq_puts(m, "\n");
 	}

 	if (stats->read_holdtime.nr) {
 		seq_printf(m, "%38s-R:", name);
 		seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
 		seq_lock_time(m, &stats->read_waittime);
 		seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
 		seq_lock_time(m, &stats->read_holdtime);
 		seq_puts(m, "\n");
 	}

 	if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
 		return;

 	if (stats->read_holdtime.nr)
 		namelen += 2;

 	for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
 		char sym[KSYM_SYMBOL_LEN];
 		char ip[32];

 		if (class->contention_point[i] == 0)
 			break;

 		if (!i)
 			seq_line(m, '-', 40-namelen, namelen);

 		sprint_symbol(sym, class->contention_point[i]);
 		snprintf(ip, sizeof(ip), "[<%p>]",
 				(void *)class->contention_point[i]);
 		seq_printf(m, "%40s %14lu %29s %s\n", name,
 				stats->contention_point[i],
 				ip, sym);
 	}
 	if (i) {
 		seq_puts(m, "\n");
 		seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
 		seq_puts(m, "\n");
 	}
 }

 static void seq_header(struct seq_file *m)
 {
 	seq_printf(m, "lock_stat version 0.2\n");
 	seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
 	seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
 			"%14s %14s\n",
 			"class name",
 			"con-bounces",
 			"contentions",
 			"waittime-min",
 			"waittime-max",
 			"waittime-total",
 			"acq-bounces",
 			"acquisitions",
 			"holdtime-min",
 			"holdtime-max",
 			"holdtime-total");
 	seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
 	seq_printf(m, "\n");
 }

 static void *ls_start(struct seq_file *m, loff_t *pos)
 {
 	struct lock_stat_seq *data = m->private;

 	if (*pos == 0)
 		return SEQ_START_TOKEN;

 	data->iter = data->stats + *pos;
 	if (data->iter >= data->iter_end)
 		data->iter = NULL;

 	return data->iter;
 }

 static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	struct lock_stat_seq *data = m->private;

 	(*pos)++;

 	if (v == SEQ_START_TOKEN)
 		data->iter = data->stats;
 	else {
 		data->iter = v;
 		data->iter++;
 	}

 	if (data->iter == data->iter_end)
 		data->iter = NULL;

 	return data->iter;
 }

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

 static int ls_show(struct seq_file *m, void *v)
 {
 	if (v == SEQ_START_TOKEN)
 		seq_header(m);
 	else
 		seq_stats(m, v);

 	return 0;
 }

 static struct seq_operations lockstat_ops = {
 	.start	= ls_start,
 	.next	= ls_next,
 	.stop	= ls_stop,
 	.show	= ls_show,
 };

 static int lock_stat_open(struct inode *inode, struct file *file)
 {
 	int res;
 	struct lock_class *class;
 	struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));

 	if (!data)
 		return -ENOMEM;

 	res = seq_open(file, &lockstat_ops);
 	if (!res) {
 		struct lock_stat_data *iter = data->stats;
 		struct seq_file *m = file->private_data;

 		data->iter = iter;
 		list_for_each_entry(class, &all_lock_classes, lock_entry) {
 			iter->class = class;
 			iter->stats = lock_stats(class);
 			iter++;
 		}
 		data->iter_end = iter;

 		sort(data->stats, data->iter_end - data->iter,
 				sizeof(struct lock_stat_data),
 				lock_stat_cmp, NULL);

 		m->private = data;
 	} else
 		vfree(data);

 	return res;
 }

 static ssize_t lock_stat_write(struct file *file, const char __user *buf,
 			       size_t count, loff_t *ppos)
 {
 	struct lock_class *class;
 	char c;

 	if (count) {
 		if (get_user(c, buf))
 			return -EFAULT;

 		if (c != '0')
 			return count;

 		list_for_each_entry(class, &all_lock_classes, lock_entry)
 			clear_lock_stats(class);
 	}
 	return count;
 }

 static int lock_stat_release(struct inode *inode, struct file *file)
 {
 	struct seq_file *seq = file->private_data;

 	vfree(seq->private);
 	seq->private = NULL;
 	return seq_release(inode, file);
 }

 static const struct file_operations proc_lock_stat_operations = {
 	.open		= lock_stat_open,
 	.write		= lock_stat_write,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= lock_stat_release,
 };
 #endif /* CONFIG_LOCK_STAT */

 static int __init lockdep_proc_init(void)
 {
 	proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
 #ifdef CONFIG_PROVE_LOCKING
 	proc_create("lockdep_chains", S_IRUSR, NULL,
 		    &proc_lockdep_chains_operations);
 #endif
 	proc_create("lockdep_stats", S_IRUSR, NULL,
 		    &proc_lockdep_stats_operations);

 #ifdef CONFIG_LOCK_STAT
 	proc_create("lock_stat", S_IRUSR, NULL, &proc_lock_stat_operations);
 #endif

 	return 0;
 }

 __initcall(lockdep_proc_init);
	/*
	* 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 unsigned long count_forward_deps(struct lock_class *class)
	{
	struct lock_list *entry;
	unsigned long ret = 1;

	/*
	* Recurse this class's dependency list:
	*/
	list_for_each_entry(entry, &class->locks_after, entry)
	ret += count_forward_deps(entry->class);

	return ret;
	}

	static unsigned long count_backward_deps(struct lock_class *class)
	{
	struct lock_list *entry;
	unsigned long ret = 1;

	/*
	* Recurse this class's dependency list:
	*/
	list_for_each_entry(entry, &class->locks_before, entry)
	ret += count_backward_deps(entry->class);

	return ret;
	}

	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)
	{
	unsigned long nr_forward_deps, nr_backward_deps;
	struct lock_class *class = v;
	struct lock_list *entry;
	char c1, c2, c3, c4;

	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
	nr_forward_deps = count_forward_deps(class);
	seq_printf(m, " FD:%5ld", nr_forward_deps);

	nr_backward_deps = count_backward_deps(class);
	seq_printf(m, " BD:%5ld", nr_backward_deps);

	get_usage_chars(class, &c1, &c2, &c3, &c4);
	seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);

	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 < nr_lock_chains)
	chain = lock_chains + *pos;
	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 < nr_lock_chains)
	return lock_chains + *pos;

	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, "all lock chains:\n");
	return 0;
	}

	seq_printf(m, "irq_context: %d\n", chain->irq_context);

	for (i = 0; i < chain->depth; i++) {
	class = lock_chain_get_class(chain, i);
	seq_printf(m, "[%p] ", class->key);
	print_name(m, class);
	seq_puts(m, "\n");
	}
	seq_puts(m, "\n");

	return 0;
	}

	static const struct seq_operations lockdep_chains_ops = {
	.start = lc_start,
	.next = lc_next,
	.stop = lc_stop,
	.show = lc_show,
	};

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

	if (nr_lock_chains)
	m->private = lock_chains;
	else
	m->private = NULL;
	}
	return res;
	}

	static const struct file_operations proc_lockdep_chains_operations = {
	.open = lockdep_chains_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release,
	};
	#endif /* CONFIG_PROVE_LOCKING */

	static void lockdep_stats_debug_show(struct seq_file *m)
	{
	#ifdef CONFIG_DEBUG_LOCKDEP
	unsigned int hi1 = debug_atomic_read(&hardirqs_on_events),
	hi2 = debug_atomic_read(&hardirqs_off_events),
	hr1 = debug_atomic_read(&redundant_hardirqs_on),
	hr2 = debug_atomic_read(&redundant_hardirqs_off),
	si1 = debug_atomic_read(&softirqs_on_events),
	si2 = debug_atomic_read(&softirqs_off_events),
	sr1 = debug_atomic_read(&redundant_softirqs_on),
	sr2 = debug_atomic_read(&redundant_softirqs_off);

	seq_printf(m, " chain lookup misses: %11u\n",
	debug_atomic_read(&chain_lookup_misses));
	seq_printf(m, " chain lookup hits: %11u\n",
	debug_atomic_read(&chain_lookup_hits));
	seq_printf(m, " cyclic checks: %11u\n",
	debug_atomic_read(&nr_cyclic_checks));
	seq_printf(m, " cyclic-check recursions: %11u\n",
	debug_atomic_read(&nr_cyclic_check_recursions));
	seq_printf(m, " find-mask forwards checks: %11u\n",
	debug_atomic_read(&nr_find_usage_forwards_checks));
	seq_printf(m, " find-mask forwards recursions: %11u\n",
	debug_atomic_read(&nr_find_usage_forwards_recursions));
	seq_printf(m, " find-mask backwards checks: %11u\n",
	debug_atomic_read(&nr_find_usage_backwards_checks));
	seq_printf(m, " find-mask backwards recursions:%11u\n",
	debug_atomic_read(&nr_find_usage_backwards_recursions));

	seq_printf(m, " hardirq on events: %11u\n", hi1);
	seq_printf(m, " hardirq off events: %11u\n", hi2);
	seq_printf(m, " redundant hardirq ons: %11u\n", hr1);
	seq_printf(m, " redundant hardirq offs: %11u\n", hr2);
	seq_printf(m, " softirq on events: %11u\n", si1);
	seq_printf(m, " softirq off events: %11u\n", si2);
	seq_printf(m, " redundant softirq ons: %11u\n", sr1);
	seq_printf(m, " redundant softirq offs: %11u\n", sr2);
	#endif
	}

	static int lockdep_stats_show(struct seq_file m, void v)
	{
	struct lock_class *class;
	unsigned long nr_unused = 0, nr_uncategorized = 0,
	nr_irq_safe = 0, nr_irq_unsafe = 0,
	nr_softirq_safe = 0, nr_softirq_unsafe = 0,
	nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
	nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
	nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
	nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
	sum_forward_deps = 0, factor = 0;

	list_for_each_entry(class, &all_lock_classes, lock_entry) {

	if (class->usage_mask == 0)
	nr_unused++;
	if (class->usage_mask == LOCKF_USED)
	nr_uncategorized++;
	if (class->usage_mask & LOCKF_USED_IN_IRQ)
	nr_irq_safe++;
	if (class->usage_mask & LOCKF_ENABLED_IRQS)
	nr_irq_unsafe++;
	if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
	nr_softirq_safe++;
	if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
	nr_softirq_unsafe++;
	if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
	nr_hardirq_safe++;
	if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
	nr_hardirq_unsafe++;
	if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
	nr_irq_read_safe++;
	if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
	nr_irq_read_unsafe++;
	if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
	nr_softirq_read_safe++;
	if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
	nr_softirq_read_unsafe++;
	if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
	nr_hardirq_read_safe++;
	if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
	nr_hardirq_read_unsafe++;

	sum_forward_deps += count_forward_deps(class);
	}
	#ifdef CONFIG_DEBUG_LOCKDEP
	DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
	#endif
	seq_printf(m, " lock-classes: %11lu [max: %lu]\n",
	nr_lock_classes, MAX_LOCKDEP_KEYS);
	seq_printf(m, " direct dependencies: %11lu [max: %lu]\n",
	nr_list_entries, MAX_LOCKDEP_ENTRIES);
	seq_printf(m, " indirect dependencies: %11lu\n",
	sum_forward_deps);

	/*
	* Total number of dependencies:
	*
	* All irq-safe locks may nest inside irq-unsafe locks,
	* plus all the other known dependencies:
	*/
	seq_printf(m, " all direct dependencies: %11lu\n",
	nr_irq_unsafe * nr_irq_safe +
	nr_hardirq_unsafe * nr_hardirq_safe +
	nr_list_entries);

	/*
	* Estimated factor between direct and indirect
	* dependencies:
	*/
	if (nr_list_entries)
	factor = sum_forward_deps / nr_list_entries;

	#ifdef CONFIG_PROVE_LOCKING
	seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
	nr_lock_chains, MAX_LOCKDEP_CHAINS);
	seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n",
	nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
	#endif

	#ifdef CONFIG_TRACE_IRQFLAGS
	seq_printf(m, " in-hardirq chains: %11u\n",
	nr_hardirq_chains);
	seq_printf(m, " in-softirq chains: %11u\n",
	nr_softirq_chains);
	#endif
	seq_printf(m, " in-process chains: %11u\n",
	nr_process_chains);
	seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n",
	nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
	seq_printf(m, " combined max dependencies: %11u\n",
	(nr_hardirq_chains + 1) *
	(nr_softirq_chains + 1) *
	(nr_process_chains + 1)
	);
	seq_printf(m, " hardirq-safe locks: %11lu\n",
	nr_hardirq_safe);
	seq_printf(m, " hardirq-unsafe locks: %11lu\n",
	nr_hardirq_unsafe);
	seq_printf(m, " softirq-safe locks: %11lu\n",
	nr_softirq_safe);
	seq_printf(m, " softirq-unsafe locks: %11lu\n",
	nr_softirq_unsafe);
	seq_printf(m, " irq-safe locks: %11lu\n",
	nr_irq_safe);
	seq_printf(m, " irq-unsafe locks: %11lu\n",
	nr_irq_unsafe);

	seq_printf(m, " hardirq-read-safe locks: %11lu\n",
	nr_hardirq_read_safe);
	seq_printf(m, " hardirq-read-unsafe locks: %11lu\n",
	nr_hardirq_read_unsafe);
	seq_printf(m, " softirq-read-safe locks: %11lu\n",
	nr_softirq_read_safe);
	seq_printf(m, " softirq-read-unsafe locks: %11lu\n",
	nr_softirq_read_unsafe);
	seq_printf(m, " irq-read-safe locks: %11lu\n",
	nr_irq_read_safe);
	seq_printf(m, " irq-read-unsafe locks: %11lu\n",
	nr_irq_read_unsafe);

	seq_printf(m, " uncategorized locks: %11lu\n",
	nr_uncategorized);
	seq_printf(m, " unused locks: %11lu\n",
	nr_unused);
	seq_printf(m, " max locking depth: %11u\n",
	max_lockdep_depth);
	seq_printf(m, " max recursion depth: %11u\n",
	max_recursion_depth);
	lockdep_stats_debug_show(m);
	seq_printf(m, " debug_locks: %11u\n",
	debug_locks);

	return 0;
	}

	static int lockdep_stats_open(struct inode inode, struct file file)
	{
	return single_open(file, lockdep_stats_show, NULL);
	}

	static const struct file_operations proc_lockdep_stats_operations = {
	.open = lockdep_stats_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	#ifdef CONFIG_LOCK_STAT

	struct lock_stat_data {
	struct lock_class *class;
	struct lock_class_stats stats;
	};

	struct lock_stat_seq {
	struct lock_stat_data *iter;
	struct lock_stat_data *iter_end;
	struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
	};

	/*
	* sort on absolute number of contentions
	*/
	static int lock_stat_cmp(const void l, const void r)
	{
	const struct lock_stat_data dl = l, dr = r;
	unsigned long nl, nr;

	nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
	nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;

	return nr - nl;
	}

	static void seq_line(struct seq_file *m, char c, int offset, int length)
	{
	int i;

	for (i = 0; i < offset; i++)
	seq_puts(m, " ");
	for (i = 0; i < length; i++)
	seq_printf(m, "%c", c);
	seq_puts(m, "\n");
	}

	static void snprint_time(char *buf, size_t bufsiz, s64 nr)
	{
	unsigned long rem;

	rem = do_div(nr, 1000); /* XXX: do_div_signed */
	snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, ((int)rem+5)/10);
	}

	static void seq_time(struct seq_file *m, s64 time)
	{
	char num[15];

	snprint_time(num, sizeof(num), time);
	seq_printf(m, " %14s", num);
	}

	static void seq_lock_time(struct seq_file m, struct lock_time lt)
	{
	seq_printf(m, "%14lu", lt->nr);
	seq_time(m, lt->min);
	seq_time(m, lt->max);
	seq_time(m, lt->total);
	}

	static void seq_stats(struct seq_file m, struct lock_stat_data data)
	{
	char name[39];
	struct lock_class *class;
	struct lock_class_stats *stats;
	int i, namelen;

	class = data->class;
	stats = &data->stats;

	namelen = 38;
	if (class->name_version > 1)
	namelen -= 2; /* XXX truncates versions > 9 */
	if (class->subclass)
	namelen -= 2;

	if (!class->name) {
	char str[KSYM_NAME_LEN];
	const char *key_name;

	key_name = __get_key_name(class->key, str);
	snprintf(name, namelen, "%s", key_name);
	} else {
	snprintf(name, namelen, "%s", class->name);
	}
	namelen = strlen(name);
	if (class->name_version > 1) {
	snprintf(name+namelen, 3, "#%d", class->name_version);
	namelen += 2;
	}
	if (class->subclass) {
	snprintf(name+namelen, 3, "/%d", class->subclass);
	namelen += 2;
	}

	if (stats->write_holdtime.nr) {
	if (stats->read_holdtime.nr)
	seq_printf(m, "%38s-W:", name);
	else
	seq_printf(m, "%40s:", name);

	seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
	seq_lock_time(m, &stats->write_waittime);
	seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
	seq_lock_time(m, &stats->write_holdtime);
	seq_puts(m, "\n");
	}

	if (stats->read_holdtime.nr) {
	seq_printf(m, "%38s-R:", name);
	seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
	seq_lock_time(m, &stats->read_waittime);
	seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
	seq_lock_time(m, &stats->read_holdtime);
	seq_puts(m, "\n");
	}

	if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
	return;

	if (stats->read_holdtime.nr)
	namelen += 2;

	for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
	char sym[KSYM_SYMBOL_LEN];
	char ip[32];

	if (class->contention_point[i] == 0)
	break;

	if (!i)
	seq_line(m, '-', 40-namelen, namelen);

	sprint_symbol(sym, class->contention_point[i]);
	snprintf(ip, sizeof(ip), "[<%p>]",
	(void *)class->contention_point[i]);
	seq_printf(m, "%40s %14lu %29s %s\n", name,
	stats->contention_point[i],
	ip, sym);
	}
	if (i) {
	seq_puts(m, "\n");
	seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
	seq_puts(m, "\n");
	}
	}

	static void seq_header(struct seq_file *m)
	{
	seq_printf(m, "lock_stat version 0.2\n");
	seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
	seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
	"%14s %14s\n",
	"class name",
	"con-bounces",
	"contentions",
	"waittime-min",
	"waittime-max",
	"waittime-total",
	"acq-bounces",
	"acquisitions",
	"holdtime-min",
	"holdtime-max",
	"holdtime-total");
	seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
	seq_printf(m, "\n");
	}

	static void ls_start(struct seq_file m, loff_t *pos)
	{
	struct lock_stat_seq *data = m->private;

	if (*pos == 0)
	return SEQ_START_TOKEN;

	data->iter = data->stats + *pos;
	if (data->iter >= data->iter_end)
	data->iter = NULL;

	return data->iter;
	}

	static void ls_next(struct seq_file m, void v, loff_t pos)
	{
	struct lock_stat_seq *data = m->private;

	(*pos)++;

	if (v == SEQ_START_TOKEN)
	data->iter = data->stats;
	else {
	data->iter = v;
	data->iter++;
	}

	if (data->iter == data->iter_end)
	data->iter = NULL;

	return data->iter;
	}

	static void ls_stop(struct seq_file m, void v)
	{
	}

	static int ls_show(struct seq_file m, void v)
	{
	if (v == SEQ_START_TOKEN)
	seq_header(m);
	else
	seq_stats(m, v);

	return 0;
	}

	static struct seq_operations lockstat_ops = {
	.start = ls_start,
	.next = ls_next,
	.stop = ls_stop,
	.show = ls_show,
	};

	static int lock_stat_open(struct inode inode, struct file file)
	{
	int res;
	struct lock_class *class;
	struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));

	if (!data)
	return -ENOMEM;

	res = seq_open(file, &lockstat_ops);
	if (!res) {
	struct lock_stat_data *iter = data->stats;
	struct seq_file *m = file->private_data;

	data->iter = iter;
	list_for_each_entry(class, &all_lock_classes, lock_entry) {
	iter->class = class;
	iter->stats = lock_stats(class);
	iter++;
	}
	data->iter_end = iter;

	sort(data->stats, data->iter_end - data->iter,
	sizeof(struct lock_stat_data),
	lock_stat_cmp, NULL);

	m->private = data;
	} else
	vfree(data);

	return res;
	}

	static ssize_t lock_stat_write(struct file file, const char __user buf,
	size_t count, loff_t *ppos)
	{
	struct lock_class *class;
	char c;

	if (count) {
	if (get_user(c, buf))
	return -EFAULT;

	if (c != '0')
	return count;

	list_for_each_entry(class, &all_lock_classes, lock_entry)
	clear_lock_stats(class);
	}
	return count;
	}

	static int lock_stat_release(struct inode inode, struct file file)
	{
	struct seq_file *seq = file->private_data;

	vfree(seq->private);
	seq->private = NULL;
	return seq_release(inode, file);
	}

	static const struct file_operations proc_lock_stat_operations = {
	.open = lock_stat_open,
	.write = lock_stat_write,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = lock_stat_release,
	};
	#endif /* CONFIG_LOCK_STAT */

	static int __init lockdep_proc_init(void)
	{
	proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
	#ifdef CONFIG_PROVE_LOCKING
	proc_create("lockdep_chains", S_IRUSR, NULL,
	&proc_lockdep_chains_operations);
	#endif
	proc_create("lockdep_stats", S_IRUSR, NULL,
	&proc_lockdep_stats_operations);

	#ifdef CONFIG_LOCK_STAT
	proc_create("lock_stat", S_IRUSR, NULL, &proc_lock_stat_operations);
	#endif

	return 0;
	}

	__initcall(lockdep_proc_init);