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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * kernel/lockdep_proc.c
4 *
5 * Runtime locking correctness validator
6 *
7 * Started by Ingo Molnar:
8 *
9 * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
10 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
11 *
12 * Code for /proc/lockdep and /proc/lockdep_stats:
13 *
14 */
15#include <linux/export.h>
16#include <linux/proc_fs.h>
17#include <linux/seq_file.h>
18#include <linux/kallsyms.h>
19#include <linux/debug_locks.h>
20#include <linux/vmalloc.h>
21#include <linux/sort.h>
22#include <linux/uaccess.h>
23#include <asm/div64.h>
24
25#include "lockdep_internals.h"
26
27static void *l_next(struct seq_file *m, void *v, loff_t *pos)
28{
29 return seq_list_next(v, &all_lock_classes, pos);
30}
31
32static void *l_start(struct seq_file *m, loff_t *pos)
33{
34 return seq_list_start_head(&all_lock_classes, *pos);
35}
36
37static void l_stop(struct seq_file *m, void *v)
38{
39}
40
41static void print_name(struct seq_file *m, struct lock_class *class)
42{
43 char str[KSYM_NAME_LEN];
44 const char *name = class->name;
45
46 if (!name) {
47 name = __get_key_name(class->key, str);
48 seq_printf(m, "%s", name);
49 } else{
50 seq_printf(m, "%s", name);
51 if (class->name_version > 1)
52 seq_printf(m, "#%d", class->name_version);
53 if (class->subclass)
54 seq_printf(m, "/%d", class->subclass);
55 }
56}
57
58static int l_show(struct seq_file *m, void *v)
59{
60 struct lock_class *class = list_entry(v, struct lock_class, lock_entry);
61 struct lock_list *entry;
62 char usage[LOCK_USAGE_CHARS];
63
64 if (v == &all_lock_classes) {
65 seq_printf(m, "all lock classes:\n");
66 return 0;
67 }
68
69 seq_printf(m, "%p", class->key);
70#ifdef CONFIG_DEBUG_LOCKDEP
71 seq_printf(m, " OPS:%8ld", class->ops);
72#endif
73#ifdef CONFIG_PROVE_LOCKING
74 seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));
75 seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
76#endif
77
78 get_usage_chars(class, usage);
79 seq_printf(m, " %s", usage);
80
81 seq_printf(m, ": ");
82 print_name(m, class);
83 seq_puts(m, "\n");
84
85 list_for_each_entry(entry, &class->locks_after, entry) {
86 if (entry->distance == 1) {
87 seq_printf(m, " -> [%p] ", entry->class->key);
88 print_name(m, entry->class);
89 seq_puts(m, "\n");
90 }
91 }
92 seq_puts(m, "\n");
93
94 return 0;
95}
96
97static const struct seq_operations lockdep_ops = {
98 .start = l_start,
99 .next = l_next,
100 .stop = l_stop,
101 .show = l_show,
102};
103
104static int lockdep_open(struct inode *inode, struct file *file)
105{
106 return seq_open(file, &lockdep_ops);
107}
108
109static const struct file_operations proc_lockdep_operations = {
110 .open = lockdep_open,
111 .read = seq_read,
112 .llseek = seq_lseek,
113 .release = seq_release,
114};
115
116#ifdef CONFIG_PROVE_LOCKING
117static void *lc_start(struct seq_file *m, loff_t *pos)
118{
119 if (*pos == 0)
120 return SEQ_START_TOKEN;
121
122 if (*pos - 1 < nr_lock_chains)
123 return lock_chains + (*pos - 1);
124
125 return NULL;
126}
127
128static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
129{
130 (*pos)++;
131 return lc_start(m, pos);
132}
133
134static void lc_stop(struct seq_file *m, void *v)
135{
136}
137
138static int lc_show(struct seq_file *m, void *v)
139{
140 struct lock_chain *chain = v;
141 struct lock_class *class;
142 int i;
143
144 if (v == SEQ_START_TOKEN) {
145 if (nr_chain_hlocks > MAX_LOCKDEP_CHAIN_HLOCKS)
146 seq_printf(m, "(buggered) ");
147 seq_printf(m, "all lock chains:\n");
148 return 0;
149 }
150
151 seq_printf(m, "irq_context: %d\n", chain->irq_context);
152
153 for (i = 0; i < chain->depth; i++) {
154 class = lock_chain_get_class(chain, i);
155 if (!class->key)
156 continue;
157
158 seq_printf(m, "[%p] ", class->key);
159 print_name(m, class);
160 seq_puts(m, "\n");
161 }
162 seq_puts(m, "\n");
163
164 return 0;
165}
166
167static const struct seq_operations lockdep_chains_ops = {
168 .start = lc_start,
169 .next = lc_next,
170 .stop = lc_stop,
171 .show = lc_show,
172};
173
174static int lockdep_chains_open(struct inode *inode, struct file *file)
175{
176 return seq_open(file, &lockdep_chains_ops);
177}
178
179static const struct file_operations proc_lockdep_chains_operations = {
180 .open = lockdep_chains_open,
181 .read = seq_read,
182 .llseek = seq_lseek,
183 .release = seq_release,
184};
185#endif /* CONFIG_PROVE_LOCKING */
186
187static void lockdep_stats_debug_show(struct seq_file *m)
188{
189#ifdef CONFIG_DEBUG_LOCKDEP
190 unsigned long long hi1 = debug_atomic_read(hardirqs_on_events),
191 hi2 = debug_atomic_read(hardirqs_off_events),
192 hr1 = debug_atomic_read(redundant_hardirqs_on),
193 hr2 = debug_atomic_read(redundant_hardirqs_off),
194 si1 = debug_atomic_read(softirqs_on_events),
195 si2 = debug_atomic_read(softirqs_off_events),
196 sr1 = debug_atomic_read(redundant_softirqs_on),
197 sr2 = debug_atomic_read(redundant_softirqs_off);
198
199 seq_printf(m, " chain lookup misses: %11llu\n",
200 debug_atomic_read(chain_lookup_misses));
201 seq_printf(m, " chain lookup hits: %11llu\n",
202 debug_atomic_read(chain_lookup_hits));
203 seq_printf(m, " cyclic checks: %11llu\n",
204 debug_atomic_read(nr_cyclic_checks));
205 seq_printf(m, " redundant checks: %11llu\n",
206 debug_atomic_read(nr_redundant_checks));
207 seq_printf(m, " redundant links: %11llu\n",
208 debug_atomic_read(nr_redundant));
209 seq_printf(m, " find-mask forwards checks: %11llu\n",
210 debug_atomic_read(nr_find_usage_forwards_checks));
211 seq_printf(m, " find-mask backwards checks: %11llu\n",
212 debug_atomic_read(nr_find_usage_backwards_checks));
213
214 seq_printf(m, " hardirq on events: %11llu\n", hi1);
215 seq_printf(m, " hardirq off events: %11llu\n", hi2);
216 seq_printf(m, " redundant hardirq ons: %11llu\n", hr1);
217 seq_printf(m, " redundant hardirq offs: %11llu\n", hr2);
218 seq_printf(m, " softirq on events: %11llu\n", si1);
219 seq_printf(m, " softirq off events: %11llu\n", si2);
220 seq_printf(m, " redundant softirq ons: %11llu\n", sr1);
221 seq_printf(m, " redundant softirq offs: %11llu\n", sr2);
222#endif
223}
224
225static int lockdep_stats_show(struct seq_file *m, void *v)
226{
227 struct lock_class *class;
228 unsigned long nr_unused = 0, nr_uncategorized = 0,
229 nr_irq_safe = 0, nr_irq_unsafe = 0,
230 nr_softirq_safe = 0, nr_softirq_unsafe = 0,
231 nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
232 nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
233 nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
234 nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
235 sum_forward_deps = 0;
236
237 list_for_each_entry(class, &all_lock_classes, lock_entry) {
238
239 if (class->usage_mask == 0)
240 nr_unused++;
241 if (class->usage_mask == LOCKF_USED)
242 nr_uncategorized++;
243 if (class->usage_mask & LOCKF_USED_IN_IRQ)
244 nr_irq_safe++;
245 if (class->usage_mask & LOCKF_ENABLED_IRQ)
246 nr_irq_unsafe++;
247 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
248 nr_softirq_safe++;
249 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
250 nr_softirq_unsafe++;
251 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
252 nr_hardirq_safe++;
253 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
254 nr_hardirq_unsafe++;
255 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
256 nr_irq_read_safe++;
257 if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
258 nr_irq_read_unsafe++;
259 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
260 nr_softirq_read_safe++;
261 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
262 nr_softirq_read_unsafe++;
263 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
264 nr_hardirq_read_safe++;
265 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
266 nr_hardirq_read_unsafe++;
267
268#ifdef CONFIG_PROVE_LOCKING
269 sum_forward_deps += lockdep_count_forward_deps(class);
270#endif
271 }
272#ifdef CONFIG_DEBUG_LOCKDEP
273 DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused);
274#endif
275 seq_printf(m, " lock-classes: %11lu [max: %lu]\n",
276 nr_lock_classes, MAX_LOCKDEP_KEYS);
277 seq_printf(m, " direct dependencies: %11lu [max: %lu]\n",
278 nr_list_entries, MAX_LOCKDEP_ENTRIES);
279 seq_printf(m, " indirect dependencies: %11lu\n",
280 sum_forward_deps);
281
282 /*
283 * Total number of dependencies:
284 *
285 * All irq-safe locks may nest inside irq-unsafe locks,
286 * plus all the other known dependencies:
287 */
288 seq_printf(m, " all direct dependencies: %11lu\n",
289 nr_irq_unsafe * nr_irq_safe +
290 nr_hardirq_unsafe * nr_hardirq_safe +
291 nr_list_entries);
292
293#ifdef CONFIG_PROVE_LOCKING
294 seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
295 nr_lock_chains, MAX_LOCKDEP_CHAINS);
296 seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n",
297 nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
298#endif
299
300#ifdef CONFIG_TRACE_IRQFLAGS
301 seq_printf(m, " in-hardirq chains: %11u\n",
302 nr_hardirq_chains);
303 seq_printf(m, " in-softirq chains: %11u\n",
304 nr_softirq_chains);
305#endif
306 seq_printf(m, " in-process chains: %11u\n",
307 nr_process_chains);
308 seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n",
309 nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
310 seq_printf(m, " combined max dependencies: %11u\n",
311 (nr_hardirq_chains + 1) *
312 (nr_softirq_chains + 1) *
313 (nr_process_chains + 1)
314 );
315 seq_printf(m, " hardirq-safe locks: %11lu\n",
316 nr_hardirq_safe);
317 seq_printf(m, " hardirq-unsafe locks: %11lu\n",
318 nr_hardirq_unsafe);
319 seq_printf(m, " softirq-safe locks: %11lu\n",
320 nr_softirq_safe);
321 seq_printf(m, " softirq-unsafe locks: %11lu\n",
322 nr_softirq_unsafe);
323 seq_printf(m, " irq-safe locks: %11lu\n",
324 nr_irq_safe);
325 seq_printf(m, " irq-unsafe locks: %11lu\n",
326 nr_irq_unsafe);
327
328 seq_printf(m, " hardirq-read-safe locks: %11lu\n",
329 nr_hardirq_read_safe);
330 seq_printf(m, " hardirq-read-unsafe locks: %11lu\n",
331 nr_hardirq_read_unsafe);
332 seq_printf(m, " softirq-read-safe locks: %11lu\n",
333 nr_softirq_read_safe);
334 seq_printf(m, " softirq-read-unsafe locks: %11lu\n",
335 nr_softirq_read_unsafe);
336 seq_printf(m, " irq-read-safe locks: %11lu\n",
337 nr_irq_read_safe);
338 seq_printf(m, " irq-read-unsafe locks: %11lu\n",
339 nr_irq_read_unsafe);
340
341 seq_printf(m, " uncategorized locks: %11lu\n",
342 nr_uncategorized);
343 seq_printf(m, " unused locks: %11lu\n",
344 nr_unused);
345 seq_printf(m, " max locking depth: %11u\n",
346 max_lockdep_depth);
347#ifdef CONFIG_PROVE_LOCKING
348 seq_printf(m, " max bfs queue depth: %11u\n",
349 max_bfs_queue_depth);
350#endif
351 lockdep_stats_debug_show(m);
352 seq_printf(m, " debug_locks: %11u\n",
353 debug_locks);
354
355 return 0;
356}
357
358static int lockdep_stats_open(struct inode *inode, struct file *file)
359{
360 return single_open(file, lockdep_stats_show, NULL);
361}
362
363static const struct file_operations proc_lockdep_stats_operations = {
364 .open = lockdep_stats_open,
365 .read = seq_read,
366 .llseek = seq_lseek,
367 .release = single_release,
368};
369
370#ifdef CONFIG_LOCK_STAT
371
372struct lock_stat_data {
373 struct lock_class *class;
374 struct lock_class_stats stats;
375};
376
377struct lock_stat_seq {
378 struct lock_stat_data *iter_end;
379 struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
380};
381
382/*
383 * sort on absolute number of contentions
384 */
385static int lock_stat_cmp(const void *l, const void *r)
386{
387 const struct lock_stat_data *dl = l, *dr = r;
388 unsigned long nl, nr;
389
390 nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
391 nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
392
393 return nr - nl;
394}
395
396static void seq_line(struct seq_file *m, char c, int offset, int length)
397{
398 int i;
399
400 for (i = 0; i < offset; i++)
401 seq_puts(m, " ");
402 for (i = 0; i < length; i++)
403 seq_printf(m, "%c", c);
404 seq_puts(m, "\n");
405}
406
407static void snprint_time(char *buf, size_t bufsiz, s64 nr)
408{
409 s64 div;
410 s32 rem;
411
412 nr += 5; /* for display rounding */
413 div = div_s64_rem(nr, 1000, &rem);
414 snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
415}
416
417static void seq_time(struct seq_file *m, s64 time)
418{
419 char num[15];
420
421 snprint_time(num, sizeof(num), time);
422 seq_printf(m, " %14s", num);
423}
424
425static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
426{
427 seq_printf(m, "%14lu", lt->nr);
428 seq_time(m, lt->min);
429 seq_time(m, lt->max);
430 seq_time(m, lt->total);
431 seq_time(m, lt->nr ? div_s64(lt->total, lt->nr) : 0);
432}
433
434static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
435{
436 struct lockdep_subclass_key *ckey;
437 struct lock_class_stats *stats;
438 struct lock_class *class;
439 const char *cname;
440 int i, namelen;
441 char name[39];
442
443 class = data->class;
444 stats = &data->stats;
445
446 namelen = 38;
447 if (class->name_version > 1)
448 namelen -= 2; /* XXX truncates versions > 9 */
449 if (class->subclass)
450 namelen -= 2;
451
452 rcu_read_lock_sched();
453 cname = rcu_dereference_sched(class->name);
454 ckey = rcu_dereference_sched(class->key);
455
456 if (!cname && !ckey) {
457 rcu_read_unlock_sched();
458 return;
459
460 } else if (!cname) {
461 char str[KSYM_NAME_LEN];
462 const char *key_name;
463
464 key_name = __get_key_name(ckey, str);
465 snprintf(name, namelen, "%s", key_name);
466 } else {
467 snprintf(name, namelen, "%s", cname);
468 }
469 rcu_read_unlock_sched();
470
471 namelen = strlen(name);
472 if (class->name_version > 1) {
473 snprintf(name+namelen, 3, "#%d", class->name_version);
474 namelen += 2;
475 }
476 if (class->subclass) {
477 snprintf(name+namelen, 3, "/%d", class->subclass);
478 namelen += 2;
479 }
480
481 if (stats->write_holdtime.nr) {
482 if (stats->read_holdtime.nr)
483 seq_printf(m, "%38s-W:", name);
484 else
485 seq_printf(m, "%40s:", name);
486
487 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
488 seq_lock_time(m, &stats->write_waittime);
489 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
490 seq_lock_time(m, &stats->write_holdtime);
491 seq_puts(m, "\n");
492 }
493
494 if (stats->read_holdtime.nr) {
495 seq_printf(m, "%38s-R:", name);
496 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
497 seq_lock_time(m, &stats->read_waittime);
498 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
499 seq_lock_time(m, &stats->read_holdtime);
500 seq_puts(m, "\n");
501 }
502
503 if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
504 return;
505
506 if (stats->read_holdtime.nr)
507 namelen += 2;
508
509 for (i = 0; i < LOCKSTAT_POINTS; i++) {
510 char ip[32];
511
512 if (class->contention_point[i] == 0)
513 break;
514
515 if (!i)
516 seq_line(m, '-', 40-namelen, namelen);
517
518 snprintf(ip, sizeof(ip), "[<%p>]",
519 (void *)class->contention_point[i]);
520 seq_printf(m, "%40s %14lu %29s %pS\n",
521 name, stats->contention_point[i],
522 ip, (void *)class->contention_point[i]);
523 }
524 for (i = 0; i < LOCKSTAT_POINTS; i++) {
525 char ip[32];
526
527 if (class->contending_point[i] == 0)
528 break;
529
530 if (!i)
531 seq_line(m, '-', 40-namelen, namelen);
532
533 snprintf(ip, sizeof(ip), "[<%p>]",
534 (void *)class->contending_point[i]);
535 seq_printf(m, "%40s %14lu %29s %pS\n",
536 name, stats->contending_point[i],
537 ip, (void *)class->contending_point[i]);
538 }
539 if (i) {
540 seq_puts(m, "\n");
541 seq_line(m, '.', 0, 40 + 1 + 12 * (14 + 1));
542 seq_puts(m, "\n");
543 }
544}
545
546static void seq_header(struct seq_file *m)
547{
548 seq_puts(m, "lock_stat version 0.4\n");
549
550 if (unlikely(!debug_locks))
551 seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
552
553 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1));
554 seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s "
555 "%14s %14s\n",
556 "class name",
557 "con-bounces",
558 "contentions",
559 "waittime-min",
560 "waittime-max",
561 "waittime-total",
562 "waittime-avg",
563 "acq-bounces",
564 "acquisitions",
565 "holdtime-min",
566 "holdtime-max",
567 "holdtime-total",
568 "holdtime-avg");
569 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1));
570 seq_printf(m, "\n");
571}
572
573static void *ls_start(struct seq_file *m, loff_t *pos)
574{
575 struct lock_stat_seq *data = m->private;
576 struct lock_stat_data *iter;
577
578 if (*pos == 0)
579 return SEQ_START_TOKEN;
580
581 iter = data->stats + (*pos - 1);
582 if (iter >= data->iter_end)
583 iter = NULL;
584
585 return iter;
586}
587
588static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
589{
590 (*pos)++;
591 return ls_start(m, pos);
592}
593
594static void ls_stop(struct seq_file *m, void *v)
595{
596}
597
598static int ls_show(struct seq_file *m, void *v)
599{
600 if (v == SEQ_START_TOKEN)
601 seq_header(m);
602 else
603 seq_stats(m, v);
604
605 return 0;
606}
607
608static const struct seq_operations lockstat_ops = {
609 .start = ls_start,
610 .next = ls_next,
611 .stop = ls_stop,
612 .show = ls_show,
613};
614
615static int lock_stat_open(struct inode *inode, struct file *file)
616{
617 int res;
618 struct lock_class *class;
619 struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
620
621 if (!data)
622 return -ENOMEM;
623
624 res = seq_open(file, &lockstat_ops);
625 if (!res) {
626 struct lock_stat_data *iter = data->stats;
627 struct seq_file *m = file->private_data;
628
629 list_for_each_entry(class, &all_lock_classes, lock_entry) {
630 iter->class = class;
631 iter->stats = lock_stats(class);
632 iter++;
633 }
634 data->iter_end = iter;
635
636 sort(data->stats, data->iter_end - data->stats,
637 sizeof(struct lock_stat_data),
638 lock_stat_cmp, NULL);
639
640 m->private = data;
641 } else
642 vfree(data);
643
644 return res;
645}
646
647static ssize_t lock_stat_write(struct file *file, const char __user *buf,
648 size_t count, loff_t *ppos)
649{
650 struct lock_class *class;
651 char c;
652
653 if (count) {
654 if (get_user(c, buf))
655 return -EFAULT;
656
657 if (c != '0')
658 return count;
659
660 list_for_each_entry(class, &all_lock_classes, lock_entry)
661 clear_lock_stats(class);
662 }
663 return count;
664}
665
666static int lock_stat_release(struct inode *inode, struct file *file)
667{
668 struct seq_file *seq = file->private_data;
669
670 vfree(seq->private);
671 return seq_release(inode, file);
672}
673
674static const struct file_operations proc_lock_stat_operations = {
675 .open = lock_stat_open,
676 .write = lock_stat_write,
677 .read = seq_read,
678 .llseek = seq_lseek,
679 .release = lock_stat_release,
680};
681#endif /* CONFIG_LOCK_STAT */
682
683static int __init lockdep_proc_init(void)
684{
685 proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
686#ifdef CONFIG_PROVE_LOCKING
687 proc_create("lockdep_chains", S_IRUSR, NULL,
688 &proc_lockdep_chains_operations);
689#endif
690 proc_create("lockdep_stats", S_IRUSR, NULL,
691 &proc_lockdep_stats_operations);
692
693#ifdef CONFIG_LOCK_STAT
694 proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL,
695 &proc_lock_stat_operations);
696#endif
697
698 return 0;
699}
700
701__initcall(lockdep_proc_init);
702
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * kernel/lockdep_proc.c
4 *
5 * Runtime locking correctness validator
6 *
7 * Started by Ingo Molnar:
8 *
9 * Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
10 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
11 *
12 * Code for /proc/lockdep and /proc/lockdep_stats:
13 *
14 */
15#include <linux/export.h>
16#include <linux/proc_fs.h>
17#include <linux/seq_file.h>
18#include <linux/kallsyms.h>
19#include <linux/debug_locks.h>
20#include <linux/vmalloc.h>
21#include <linux/sort.h>
22#include <linux/uaccess.h>
23#include <asm/div64.h>
24
25#include "lockdep_internals.h"
26
27/*
28 * Since iteration of lock_classes is done without holding the lockdep lock,
29 * it is not safe to iterate all_lock_classes list directly as the iteration
30 * may branch off to free_lock_classes or the zapped list. Iteration is done
31 * directly on the lock_classes array by checking the lock_classes_in_use
32 * bitmap and max_lock_class_idx.
33 */
34#define iterate_lock_classes(idx, class) \
35 for (idx = 0, class = lock_classes; idx <= max_lock_class_idx; \
36 idx++, class++)
37
38static void *l_next(struct seq_file *m, void *v, loff_t *pos)
39{
40 struct lock_class *class = v;
41
42 ++class;
43 *pos = class - lock_classes;
44 return (*pos > max_lock_class_idx) ? NULL : class;
45}
46
47static void *l_start(struct seq_file *m, loff_t *pos)
48{
49 unsigned long idx = *pos;
50
51 if (idx > max_lock_class_idx)
52 return NULL;
53 return lock_classes + idx;
54}
55
56static void l_stop(struct seq_file *m, void *v)
57{
58}
59
60static void print_name(struct seq_file *m, struct lock_class *class)
61{
62 char str[KSYM_NAME_LEN];
63 const char *name = class->name;
64
65 if (!name) {
66 name = __get_key_name(class->key, str);
67 seq_printf(m, "%s", name);
68 } else{
69 seq_printf(m, "%s", name);
70 if (class->name_version > 1)
71 seq_printf(m, "#%d", class->name_version);
72 if (class->subclass)
73 seq_printf(m, "/%d", class->subclass);
74 }
75}
76
77static int l_show(struct seq_file *m, void *v)
78{
79 struct lock_class *class = v;
80 struct lock_list *entry;
81 char usage[LOCK_USAGE_CHARS];
82 int idx = class - lock_classes;
83
84 if (v == lock_classes)
85 seq_printf(m, "all lock classes:\n");
86
87 if (!test_bit(idx, lock_classes_in_use))
88 return 0;
89
90 seq_printf(m, "%p", class->key);
91#ifdef CONFIG_DEBUG_LOCKDEP
92 seq_printf(m, " OPS:%8ld", debug_class_ops_read(class));
93#endif
94 if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
95 seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));
96 seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
97
98 get_usage_chars(class, usage);
99 seq_printf(m, " %s", usage);
100 }
101
102 seq_printf(m, ": ");
103 print_name(m, class);
104 seq_puts(m, "\n");
105
106 if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
107 list_for_each_entry(entry, &class->locks_after, entry) {
108 if (entry->distance == 1) {
109 seq_printf(m, " -> [%p] ", entry->class->key);
110 print_name(m, entry->class);
111 seq_puts(m, "\n");
112 }
113 }
114 seq_puts(m, "\n");
115 }
116
117 return 0;
118}
119
120static const struct seq_operations lockdep_ops = {
121 .start = l_start,
122 .next = l_next,
123 .stop = l_stop,
124 .show = l_show,
125};
126
127#ifdef CONFIG_PROVE_LOCKING
128static void *lc_start(struct seq_file *m, loff_t *pos)
129{
130 if (*pos < 0)
131 return NULL;
132
133 if (*pos == 0)
134 return SEQ_START_TOKEN;
135
136 return lock_chains + (*pos - 1);
137}
138
139static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
140{
141 *pos = lockdep_next_lockchain(*pos - 1) + 1;
142 return lc_start(m, pos);
143}
144
145static void lc_stop(struct seq_file *m, void *v)
146{
147}
148
149static int lc_show(struct seq_file *m, void *v)
150{
151 struct lock_chain *chain = v;
152 struct lock_class *class;
153 int i;
154 static const char * const irq_strs[] = {
155 [0] = "0",
156 [LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq",
157 [LOCK_CHAIN_SOFTIRQ_CONTEXT] = "softirq",
158 [LOCK_CHAIN_SOFTIRQ_CONTEXT|
159 LOCK_CHAIN_HARDIRQ_CONTEXT] = "hardirq|softirq",
160 };
161
162 if (v == SEQ_START_TOKEN) {
163 if (!nr_free_chain_hlocks)
164 seq_printf(m, "(buggered) ");
165 seq_printf(m, "all lock chains:\n");
166 return 0;
167 }
168
169 seq_printf(m, "irq_context: %s\n", irq_strs[chain->irq_context]);
170
171 for (i = 0; i < chain->depth; i++) {
172 class = lock_chain_get_class(chain, i);
173 if (!class->key)
174 continue;
175
176 seq_printf(m, "[%p] ", class->key);
177 print_name(m, class);
178 seq_puts(m, "\n");
179 }
180 seq_puts(m, "\n");
181
182 return 0;
183}
184
185static const struct seq_operations lockdep_chains_ops = {
186 .start = lc_start,
187 .next = lc_next,
188 .stop = lc_stop,
189 .show = lc_show,
190};
191#endif /* CONFIG_PROVE_LOCKING */
192
193static void lockdep_stats_debug_show(struct seq_file *m)
194{
195#ifdef CONFIG_DEBUG_LOCKDEP
196 unsigned long long hi1 = debug_atomic_read(hardirqs_on_events),
197 hi2 = debug_atomic_read(hardirqs_off_events),
198 hr1 = debug_atomic_read(redundant_hardirqs_on),
199 hr2 = debug_atomic_read(redundant_hardirqs_off),
200 si1 = debug_atomic_read(softirqs_on_events),
201 si2 = debug_atomic_read(softirqs_off_events),
202 sr1 = debug_atomic_read(redundant_softirqs_on),
203 sr2 = debug_atomic_read(redundant_softirqs_off);
204
205 seq_printf(m, " chain lookup misses: %11llu\n",
206 debug_atomic_read(chain_lookup_misses));
207 seq_printf(m, " chain lookup hits: %11llu\n",
208 debug_atomic_read(chain_lookup_hits));
209 seq_printf(m, " cyclic checks: %11llu\n",
210 debug_atomic_read(nr_cyclic_checks));
211 seq_printf(m, " redundant checks: %11llu\n",
212 debug_atomic_read(nr_redundant_checks));
213 seq_printf(m, " redundant links: %11llu\n",
214 debug_atomic_read(nr_redundant));
215 seq_printf(m, " find-mask forwards checks: %11llu\n",
216 debug_atomic_read(nr_find_usage_forwards_checks));
217 seq_printf(m, " find-mask backwards checks: %11llu\n",
218 debug_atomic_read(nr_find_usage_backwards_checks));
219
220 seq_printf(m, " hardirq on events: %11llu\n", hi1);
221 seq_printf(m, " hardirq off events: %11llu\n", hi2);
222 seq_printf(m, " redundant hardirq ons: %11llu\n", hr1);
223 seq_printf(m, " redundant hardirq offs: %11llu\n", hr2);
224 seq_printf(m, " softirq on events: %11llu\n", si1);
225 seq_printf(m, " softirq off events: %11llu\n", si2);
226 seq_printf(m, " redundant softirq ons: %11llu\n", sr1);
227 seq_printf(m, " redundant softirq offs: %11llu\n", sr2);
228#endif
229}
230
231static int lockdep_stats_show(struct seq_file *m, void *v)
232{
233 unsigned long nr_unused = 0, nr_uncategorized = 0,
234 nr_irq_safe = 0, nr_irq_unsafe = 0,
235 nr_softirq_safe = 0, nr_softirq_unsafe = 0,
236 nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
237 nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
238 nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
239 nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
240 sum_forward_deps = 0;
241
242#ifdef CONFIG_PROVE_LOCKING
243 struct lock_class *class;
244 unsigned long idx;
245
246 iterate_lock_classes(idx, class) {
247 if (!test_bit(idx, lock_classes_in_use))
248 continue;
249
250 if (class->usage_mask == 0)
251 nr_unused++;
252 if (class->usage_mask == LOCKF_USED)
253 nr_uncategorized++;
254 if (class->usage_mask & LOCKF_USED_IN_IRQ)
255 nr_irq_safe++;
256 if (class->usage_mask & LOCKF_ENABLED_IRQ)
257 nr_irq_unsafe++;
258 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
259 nr_softirq_safe++;
260 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
261 nr_softirq_unsafe++;
262 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
263 nr_hardirq_safe++;
264 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
265 nr_hardirq_unsafe++;
266 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
267 nr_irq_read_safe++;
268 if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
269 nr_irq_read_unsafe++;
270 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
271 nr_softirq_read_safe++;
272 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
273 nr_softirq_read_unsafe++;
274 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
275 nr_hardirq_read_safe++;
276 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
277 nr_hardirq_read_unsafe++;
278
279 sum_forward_deps += lockdep_count_forward_deps(class);
280 }
281
282#ifdef CONFIG_DEBUG_LOCKDEP
283 DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused);
284#endif
285
286#endif
287 seq_printf(m, " lock-classes: %11lu [max: %lu]\n",
288 nr_lock_classes, MAX_LOCKDEP_KEYS);
289 seq_printf(m, " direct dependencies: %11lu [max: %lu]\n",
290 nr_list_entries, MAX_LOCKDEP_ENTRIES);
291 seq_printf(m, " indirect dependencies: %11lu\n",
292 sum_forward_deps);
293
294 /*
295 * Total number of dependencies:
296 *
297 * All irq-safe locks may nest inside irq-unsafe locks,
298 * plus all the other known dependencies:
299 */
300 seq_printf(m, " all direct dependencies: %11lu\n",
301 nr_irq_unsafe * nr_irq_safe +
302 nr_hardirq_unsafe * nr_hardirq_safe +
303 nr_list_entries);
304
305#ifdef CONFIG_PROVE_LOCKING
306 seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
307 lock_chain_count(), MAX_LOCKDEP_CHAINS);
308 seq_printf(m, " dependency chain hlocks used: %11lu [max: %lu]\n",
309 MAX_LOCKDEP_CHAIN_HLOCKS -
310 (nr_free_chain_hlocks + nr_lost_chain_hlocks),
311 MAX_LOCKDEP_CHAIN_HLOCKS);
312 seq_printf(m, " dependency chain hlocks lost: %11u\n",
313 nr_lost_chain_hlocks);
314#endif
315
316#ifdef CONFIG_TRACE_IRQFLAGS
317 seq_printf(m, " in-hardirq chains: %11u\n",
318 nr_hardirq_chains);
319 seq_printf(m, " in-softirq chains: %11u\n",
320 nr_softirq_chains);
321#endif
322 seq_printf(m, " in-process chains: %11u\n",
323 nr_process_chains);
324 seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n",
325 nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
326#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
327 seq_printf(m, " number of stack traces: %11llu\n",
328 lockdep_stack_trace_count());
329 seq_printf(m, " number of stack hash chains: %11llu\n",
330 lockdep_stack_hash_count());
331#endif
332 seq_printf(m, " combined max dependencies: %11u\n",
333 (nr_hardirq_chains + 1) *
334 (nr_softirq_chains + 1) *
335 (nr_process_chains + 1)
336 );
337 seq_printf(m, " hardirq-safe locks: %11lu\n",
338 nr_hardirq_safe);
339 seq_printf(m, " hardirq-unsafe locks: %11lu\n",
340 nr_hardirq_unsafe);
341 seq_printf(m, " softirq-safe locks: %11lu\n",
342 nr_softirq_safe);
343 seq_printf(m, " softirq-unsafe locks: %11lu\n",
344 nr_softirq_unsafe);
345 seq_printf(m, " irq-safe locks: %11lu\n",
346 nr_irq_safe);
347 seq_printf(m, " irq-unsafe locks: %11lu\n",
348 nr_irq_unsafe);
349
350 seq_printf(m, " hardirq-read-safe locks: %11lu\n",
351 nr_hardirq_read_safe);
352 seq_printf(m, " hardirq-read-unsafe locks: %11lu\n",
353 nr_hardirq_read_unsafe);
354 seq_printf(m, " softirq-read-safe locks: %11lu\n",
355 nr_softirq_read_safe);
356 seq_printf(m, " softirq-read-unsafe locks: %11lu\n",
357 nr_softirq_read_unsafe);
358 seq_printf(m, " irq-read-safe locks: %11lu\n",
359 nr_irq_read_safe);
360 seq_printf(m, " irq-read-unsafe locks: %11lu\n",
361 nr_irq_read_unsafe);
362
363 seq_printf(m, " uncategorized locks: %11lu\n",
364 nr_uncategorized);
365 seq_printf(m, " unused locks: %11lu\n",
366 nr_unused);
367 seq_printf(m, " max locking depth: %11u\n",
368 max_lockdep_depth);
369#ifdef CONFIG_PROVE_LOCKING
370 seq_printf(m, " max bfs queue depth: %11u\n",
371 max_bfs_queue_depth);
372#endif
373 seq_printf(m, " max lock class index: %11lu\n",
374 max_lock_class_idx);
375 lockdep_stats_debug_show(m);
376 seq_printf(m, " debug_locks: %11u\n",
377 debug_locks);
378
379 /*
380 * Zapped classes and lockdep data buffers reuse statistics.
381 */
382 seq_puts(m, "\n");
383 seq_printf(m, " zapped classes: %11lu\n",
384 nr_zapped_classes);
385#ifdef CONFIG_PROVE_LOCKING
386 seq_printf(m, " zapped lock chains: %11lu\n",
387 nr_zapped_lock_chains);
388 seq_printf(m, " large chain blocks: %11u\n",
389 nr_large_chain_blocks);
390#endif
391 return 0;
392}
393
394#ifdef CONFIG_LOCK_STAT
395
396struct lock_stat_data {
397 struct lock_class *class;
398 struct lock_class_stats stats;
399};
400
401struct lock_stat_seq {
402 struct lock_stat_data *iter_end;
403 struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
404};
405
406/*
407 * sort on absolute number of contentions
408 */
409static int lock_stat_cmp(const void *l, const void *r)
410{
411 const struct lock_stat_data *dl = l, *dr = r;
412 unsigned long nl, nr;
413
414 nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
415 nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
416
417 return nr - nl;
418}
419
420static void seq_line(struct seq_file *m, char c, int offset, int length)
421{
422 int i;
423
424 for (i = 0; i < offset; i++)
425 seq_puts(m, " ");
426 for (i = 0; i < length; i++)
427 seq_putc(m, c);
428 seq_puts(m, "\n");
429}
430
431static void snprint_time(char *buf, size_t bufsiz, s64 nr)
432{
433 s64 div;
434 s32 rem;
435
436 nr += 5; /* for display rounding */
437 div = div_s64_rem(nr, 1000, &rem);
438 snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
439}
440
441static void seq_time(struct seq_file *m, s64 time)
442{
443 char num[22];
444
445 snprint_time(num, sizeof(num), time);
446 seq_printf(m, " %14s", num);
447}
448
449static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
450{
451 seq_printf(m, "%14lu", lt->nr);
452 seq_time(m, lt->min);
453 seq_time(m, lt->max);
454 seq_time(m, lt->total);
455 seq_time(m, lt->nr ? div64_u64(lt->total, lt->nr) : 0);
456}
457
458static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
459{
460 const struct lockdep_subclass_key *ckey;
461 struct lock_class_stats *stats;
462 struct lock_class *class;
463 const char *cname;
464 int i, namelen;
465 char name[39];
466
467 class = data->class;
468 stats = &data->stats;
469
470 namelen = 38;
471 if (class->name_version > 1)
472 namelen -= 2; /* XXX truncates versions > 9 */
473 if (class->subclass)
474 namelen -= 2;
475
476 rcu_read_lock_sched();
477 cname = rcu_dereference_sched(class->name);
478 ckey = rcu_dereference_sched(class->key);
479
480 if (!cname && !ckey) {
481 rcu_read_unlock_sched();
482 return;
483
484 } else if (!cname) {
485 char str[KSYM_NAME_LEN];
486 const char *key_name;
487
488 key_name = __get_key_name(ckey, str);
489 snprintf(name, namelen, "%s", key_name);
490 } else {
491 snprintf(name, namelen, "%s", cname);
492 }
493 rcu_read_unlock_sched();
494
495 namelen = strlen(name);
496 if (class->name_version > 1) {
497 snprintf(name+namelen, 3, "#%d", class->name_version);
498 namelen += 2;
499 }
500 if (class->subclass) {
501 snprintf(name+namelen, 3, "/%d", class->subclass);
502 namelen += 2;
503 }
504
505 if (stats->write_holdtime.nr) {
506 if (stats->read_holdtime.nr)
507 seq_printf(m, "%38s-W:", name);
508 else
509 seq_printf(m, "%40s:", name);
510
511 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
512 seq_lock_time(m, &stats->write_waittime);
513 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
514 seq_lock_time(m, &stats->write_holdtime);
515 seq_puts(m, "\n");
516 }
517
518 if (stats->read_holdtime.nr) {
519 seq_printf(m, "%38s-R:", name);
520 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
521 seq_lock_time(m, &stats->read_waittime);
522 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
523 seq_lock_time(m, &stats->read_holdtime);
524 seq_puts(m, "\n");
525 }
526
527 if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
528 return;
529
530 if (stats->read_holdtime.nr)
531 namelen += 2;
532
533 for (i = 0; i < LOCKSTAT_POINTS; i++) {
534 char ip[32];
535
536 if (class->contention_point[i] == 0)
537 break;
538
539 if (!i)
540 seq_line(m, '-', 40-namelen, namelen);
541
542 snprintf(ip, sizeof(ip), "[<%p>]",
543 (void *)class->contention_point[i]);
544 seq_printf(m, "%40s %14lu %29s %pS\n",
545 name, stats->contention_point[i],
546 ip, (void *)class->contention_point[i]);
547 }
548 for (i = 0; i < LOCKSTAT_POINTS; i++) {
549 char ip[32];
550
551 if (class->contending_point[i] == 0)
552 break;
553
554 if (!i)
555 seq_line(m, '-', 40-namelen, namelen);
556
557 snprintf(ip, sizeof(ip), "[<%p>]",
558 (void *)class->contending_point[i]);
559 seq_printf(m, "%40s %14lu %29s %pS\n",
560 name, stats->contending_point[i],
561 ip, (void *)class->contending_point[i]);
562 }
563 if (i) {
564 seq_puts(m, "\n");
565 seq_line(m, '.', 0, 40 + 1 + 12 * (14 + 1));
566 seq_puts(m, "\n");
567 }
568}
569
570static void seq_header(struct seq_file *m)
571{
572 seq_puts(m, "lock_stat version 0.4\n");
573
574 if (unlikely(!debug_locks))
575 seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
576
577 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1));
578 seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s "
579 "%14s %14s\n",
580 "class name",
581 "con-bounces",
582 "contentions",
583 "waittime-min",
584 "waittime-max",
585 "waittime-total",
586 "waittime-avg",
587 "acq-bounces",
588 "acquisitions",
589 "holdtime-min",
590 "holdtime-max",
591 "holdtime-total",
592 "holdtime-avg");
593 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1));
594 seq_printf(m, "\n");
595}
596
597static void *ls_start(struct seq_file *m, loff_t *pos)
598{
599 struct lock_stat_seq *data = m->private;
600 struct lock_stat_data *iter;
601
602 if (*pos == 0)
603 return SEQ_START_TOKEN;
604
605 iter = data->stats + (*pos - 1);
606 if (iter >= data->iter_end)
607 iter = NULL;
608
609 return iter;
610}
611
612static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
613{
614 (*pos)++;
615 return ls_start(m, pos);
616}
617
618static void ls_stop(struct seq_file *m, void *v)
619{
620}
621
622static int ls_show(struct seq_file *m, void *v)
623{
624 if (v == SEQ_START_TOKEN)
625 seq_header(m);
626 else
627 seq_stats(m, v);
628
629 return 0;
630}
631
632static const struct seq_operations lockstat_ops = {
633 .start = ls_start,
634 .next = ls_next,
635 .stop = ls_stop,
636 .show = ls_show,
637};
638
639static int lock_stat_open(struct inode *inode, struct file *file)
640{
641 int res;
642 struct lock_class *class;
643 struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
644
645 if (!data)
646 return -ENOMEM;
647
648 res = seq_open(file, &lockstat_ops);
649 if (!res) {
650 struct lock_stat_data *iter = data->stats;
651 struct seq_file *m = file->private_data;
652 unsigned long idx;
653
654 iterate_lock_classes(idx, class) {
655 if (!test_bit(idx, lock_classes_in_use))
656 continue;
657 iter->class = class;
658 iter->stats = lock_stats(class);
659 iter++;
660 }
661
662 data->iter_end = iter;
663
664 sort(data->stats, data->iter_end - data->stats,
665 sizeof(struct lock_stat_data),
666 lock_stat_cmp, NULL);
667
668 m->private = data;
669 } else
670 vfree(data);
671
672 return res;
673}
674
675static ssize_t lock_stat_write(struct file *file, const char __user *buf,
676 size_t count, loff_t *ppos)
677{
678 struct lock_class *class;
679 unsigned long idx;
680 char c;
681
682 if (count) {
683 if (get_user(c, buf))
684 return -EFAULT;
685
686 if (c != '0')
687 return count;
688
689 iterate_lock_classes(idx, class) {
690 if (!test_bit(idx, lock_classes_in_use))
691 continue;
692 clear_lock_stats(class);
693 }
694 }
695 return count;
696}
697
698static int lock_stat_release(struct inode *inode, struct file *file)
699{
700 struct seq_file *seq = file->private_data;
701
702 vfree(seq->private);
703 return seq_release(inode, file);
704}
705
706static const struct proc_ops lock_stat_proc_ops = {
707 .proc_open = lock_stat_open,
708 .proc_write = lock_stat_write,
709 .proc_read = seq_read,
710 .proc_lseek = seq_lseek,
711 .proc_release = lock_stat_release,
712};
713#endif /* CONFIG_LOCK_STAT */
714
715static int __init lockdep_proc_init(void)
716{
717 proc_create_seq("lockdep", S_IRUSR, NULL, &lockdep_ops);
718#ifdef CONFIG_PROVE_LOCKING
719 proc_create_seq("lockdep_chains", S_IRUSR, NULL, &lockdep_chains_ops);
720#endif
721 proc_create_single("lockdep_stats", S_IRUSR, NULL, lockdep_stats_show);
722#ifdef CONFIG_LOCK_STAT
723 proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL, &lock_stat_proc_ops);
724#endif
725
726 return 0;
727}
728
729__initcall(lockdep_proc_init);
730