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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 <[email protected]>
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, " dynamic-keys: %11lu\n",
290 nr_dynamic_keys);
291 seq_printf(m, " direct dependencies: %11lu [max: %lu]\n",
292 nr_list_entries, MAX_LOCKDEP_ENTRIES);
293 seq_printf(m, " indirect dependencies: %11lu\n",
294 sum_forward_deps);
295
296 /*
297 * Total number of dependencies:
298 *
299 * All irq-safe locks may nest inside irq-unsafe locks,
300 * plus all the other known dependencies:
301 */
302 seq_printf(m, " all direct dependencies: %11lu\n",
303 nr_irq_unsafe * nr_irq_safe +
304 nr_hardirq_unsafe * nr_hardirq_safe +
305 nr_list_entries);
306
307#ifdef CONFIG_PROVE_LOCKING
308 seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
309 lock_chain_count(), MAX_LOCKDEP_CHAINS);
310 seq_printf(m, " dependency chain hlocks used: %11lu [max: %lu]\n",
311 MAX_LOCKDEP_CHAIN_HLOCKS -
312 (nr_free_chain_hlocks + nr_lost_chain_hlocks),
313 MAX_LOCKDEP_CHAIN_HLOCKS);
314 seq_printf(m, " dependency chain hlocks lost: %11u\n",
315 nr_lost_chain_hlocks);
316#endif
317
318#ifdef CONFIG_TRACE_IRQFLAGS
319 seq_printf(m, " in-hardirq chains: %11u\n",
320 nr_hardirq_chains);
321 seq_printf(m, " in-softirq chains: %11u\n",
322 nr_softirq_chains);
323#endif
324 seq_printf(m, " in-process chains: %11u\n",
325 nr_process_chains);
326 seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n",
327 nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
328#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING)
329 seq_printf(m, " number of stack traces: %11llu\n",
330 lockdep_stack_trace_count());
331 seq_printf(m, " number of stack hash chains: %11llu\n",
332 lockdep_stack_hash_count());
333#endif
334 seq_printf(m, " combined max dependencies: %11u\n",
335 (nr_hardirq_chains + 1) *
336 (nr_softirq_chains + 1) *
337 (nr_process_chains + 1)
338 );
339 seq_printf(m, " hardirq-safe locks: %11lu\n",
340 nr_hardirq_safe);
341 seq_printf(m, " hardirq-unsafe locks: %11lu\n",
342 nr_hardirq_unsafe);
343 seq_printf(m, " softirq-safe locks: %11lu\n",
344 nr_softirq_safe);
345 seq_printf(m, " softirq-unsafe locks: %11lu\n",
346 nr_softirq_unsafe);
347 seq_printf(m, " irq-safe locks: %11lu\n",
348 nr_irq_safe);
349 seq_printf(m, " irq-unsafe locks: %11lu\n",
350 nr_irq_unsafe);
351
352 seq_printf(m, " hardirq-read-safe locks: %11lu\n",
353 nr_hardirq_read_safe);
354 seq_printf(m, " hardirq-read-unsafe locks: %11lu\n",
355 nr_hardirq_read_unsafe);
356 seq_printf(m, " softirq-read-safe locks: %11lu\n",
357 nr_softirq_read_safe);
358 seq_printf(m, " softirq-read-unsafe locks: %11lu\n",
359 nr_softirq_read_unsafe);
360 seq_printf(m, " irq-read-safe locks: %11lu\n",
361 nr_irq_read_safe);
362 seq_printf(m, " irq-read-unsafe locks: %11lu\n",
363 nr_irq_read_unsafe);
364
365 seq_printf(m, " uncategorized locks: %11lu\n",
366 nr_uncategorized);
367 seq_printf(m, " unused locks: %11lu\n",
368 nr_unused);
369 seq_printf(m, " max locking depth: %11u\n",
370 max_lockdep_depth);
371#ifdef CONFIG_PROVE_LOCKING
372 seq_printf(m, " max bfs queue depth: %11u\n",
373 max_bfs_queue_depth);
374#endif
375 seq_printf(m, " max lock class index: %11lu\n",
376 max_lock_class_idx);
377 lockdep_stats_debug_show(m);
378 seq_printf(m, " debug_locks: %11u\n",
379 debug_locks);
380
381 /*
382 * Zapped classes and lockdep data buffers reuse statistics.
383 */
384 seq_puts(m, "\n");
385 seq_printf(m, " zapped classes: %11lu\n",
386 nr_zapped_classes);
387#ifdef CONFIG_PROVE_LOCKING
388 seq_printf(m, " zapped lock chains: %11lu\n",
389 nr_zapped_lock_chains);
390 seq_printf(m, " large chain blocks: %11u\n",
391 nr_large_chain_blocks);
392#endif
393 return 0;
394}
395
396#ifdef CONFIG_LOCK_STAT
397
398struct lock_stat_data {
399 struct lock_class *class;
400 struct lock_class_stats stats;
401};
402
403struct lock_stat_seq {
404 struct lock_stat_data *iter_end;
405 struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
406};
407
408/*
409 * sort on absolute number of contentions
410 */
411static int lock_stat_cmp(const void *l, const void *r)
412{
413 const struct lock_stat_data *dl = l, *dr = r;
414 unsigned long nl, nr;
415
416 nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
417 nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
418
419 return nr - nl;
420}
421
422static void seq_line(struct seq_file *m, char c, int offset, int length)
423{
424 int i;
425
426 for (i = 0; i < offset; i++)
427 seq_puts(m, " ");
428 for (i = 0; i < length; i++)
429 seq_putc(m, c);
430 seq_puts(m, "\n");
431}
432
433static void snprint_time(char *buf, size_t bufsiz, s64 nr)
434{
435 s64 div;
436 s32 rem;
437
438 nr += 5; /* for display rounding */
439 div = div_s64_rem(nr, 1000, &rem);
440 snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
441}
442
443static void seq_time(struct seq_file *m, s64 time)
444{
445 char num[22];
446
447 snprint_time(num, sizeof(num), time);
448 seq_printf(m, " %14s", num);
449}
450
451static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
452{
453 seq_printf(m, "%14lu", lt->nr);
454 seq_time(m, lt->min);
455 seq_time(m, lt->max);
456 seq_time(m, lt->total);
457 seq_time(m, lt->nr ? div64_u64(lt->total, lt->nr) : 0);
458}
459
460static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
461{
462 const struct lockdep_subclass_key *ckey;
463 struct lock_class_stats *stats;
464 struct lock_class *class;
465 const char *cname;
466 int i, namelen;
467 char name[39];
468
469 class = data->class;
470 stats = &data->stats;
471
472 namelen = 38;
473 if (class->name_version > 1)
474 namelen -= 2; /* XXX truncates versions > 9 */
475 if (class->subclass)
476 namelen -= 2;
477
478 rcu_read_lock_sched();
479 cname = rcu_dereference_sched(class->name);
480 ckey = rcu_dereference_sched(class->key);
481
482 if (!cname && !ckey) {
483 rcu_read_unlock_sched();
484 return;
485
486 } else if (!cname) {
487 char str[KSYM_NAME_LEN];
488 const char *key_name;
489
490 key_name = __get_key_name(ckey, str);
491 snprintf(name, namelen, "%s", key_name);
492 } else {
493 snprintf(name, namelen, "%s", cname);
494 }
495 rcu_read_unlock_sched();
496
497 namelen = strlen(name);
498 if (class->name_version > 1) {
499 snprintf(name+namelen, 3, "#%d", class->name_version);
500 namelen += 2;
501 }
502 if (class->subclass) {
503 snprintf(name+namelen, 3, "/%d", class->subclass);
504 namelen += 2;
505 }
506
507 if (stats->write_holdtime.nr) {
508 if (stats->read_holdtime.nr)
509 seq_printf(m, "%38s-W:", name);
510 else
511 seq_printf(m, "%40s:", name);
512
513 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
514 seq_lock_time(m, &stats->write_waittime);
515 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
516 seq_lock_time(m, &stats->write_holdtime);
517 seq_puts(m, "\n");
518 }
519
520 if (stats->read_holdtime.nr) {
521 seq_printf(m, "%38s-R:", name);
522 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
523 seq_lock_time(m, &stats->read_waittime);
524 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
525 seq_lock_time(m, &stats->read_holdtime);
526 seq_puts(m, "\n");
527 }
528
529 if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
530 return;
531
532 if (stats->read_holdtime.nr)
533 namelen += 2;
534
535 for (i = 0; i < LOCKSTAT_POINTS; i++) {
536 char ip[32];
537
538 if (class->contention_point[i] == 0)
539 break;
540
541 if (!i)
542 seq_line(m, '-', 40-namelen, namelen);
543
544 snprintf(ip, sizeof(ip), "[<%p>]",
545 (void *)class->contention_point[i]);
546 seq_printf(m, "%40s %14lu %29s %pS\n",
547 name, stats->contention_point[i],
548 ip, (void *)class->contention_point[i]);
549 }
550 for (i = 0; i < LOCKSTAT_POINTS; i++) {
551 char ip[32];
552
553 if (class->contending_point[i] == 0)
554 break;
555
556 if (!i)
557 seq_line(m, '-', 40-namelen, namelen);
558
559 snprintf(ip, sizeof(ip), "[<%p>]",
560 (void *)class->contending_point[i]);
561 seq_printf(m, "%40s %14lu %29s %pS\n",
562 name, stats->contending_point[i],
563 ip, (void *)class->contending_point[i]);
564 }
565 if (i) {
566 seq_puts(m, "\n");
567 seq_line(m, '.', 0, 40 + 1 + 12 * (14 + 1));
568 seq_puts(m, "\n");
569 }
570}
571
572static void seq_header(struct seq_file *m)
573{
574 seq_puts(m, "lock_stat version 0.4\n");
575
576 if (unlikely(!debug_locks))
577 seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
578
579 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1));
580 seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s "
581 "%14s %14s\n",
582 "class name",
583 "con-bounces",
584 "contentions",
585 "waittime-min",
586 "waittime-max",
587 "waittime-total",
588 "waittime-avg",
589 "acq-bounces",
590 "acquisitions",
591 "holdtime-min",
592 "holdtime-max",
593 "holdtime-total",
594 "holdtime-avg");
595 seq_line(m, '-', 0, 40 + 1 + 12 * (14 + 1));
596 seq_printf(m, "\n");
597}
598
599static void *ls_start(struct seq_file *m, loff_t *pos)
600{
601 struct lock_stat_seq *data = m->private;
602 struct lock_stat_data *iter;
603
604 if (*pos == 0)
605 return SEQ_START_TOKEN;
606
607 iter = data->stats + (*pos - 1);
608 if (iter >= data->iter_end)
609 iter = NULL;
610
611 return iter;
612}
613
614static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
615{
616 (*pos)++;
617 return ls_start(m, pos);
618}
619
620static void ls_stop(struct seq_file *m, void *v)
621{
622}
623
624static int ls_show(struct seq_file *m, void *v)
625{
626 if (v == SEQ_START_TOKEN)
627 seq_header(m);
628 else
629 seq_stats(m, v);
630
631 return 0;
632}
633
634static const struct seq_operations lockstat_ops = {
635 .start = ls_start,
636 .next = ls_next,
637 .stop = ls_stop,
638 .show = ls_show,
639};
640
641static int lock_stat_open(struct inode *inode, struct file *file)
642{
643 int res;
644 struct lock_class *class;
645 struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
646
647 if (!data)
648 return -ENOMEM;
649
650 res = seq_open(file, &lockstat_ops);
651 if (!res) {
652 struct lock_stat_data *iter = data->stats;
653 struct seq_file *m = file->private_data;
654 unsigned long idx;
655
656 iterate_lock_classes(idx, class) {
657 if (!test_bit(idx, lock_classes_in_use))
658 continue;
659 iter->class = class;
660 lock_stats(class, &iter->stats);
661 iter++;
662 }
663
664 data->iter_end = iter;
665
666 sort(data->stats, data->iter_end - data->stats,
667 sizeof(struct lock_stat_data),
668 lock_stat_cmp, NULL);
669
670 m->private = data;
671 } else
672 vfree(data);
673
674 return res;
675}
676
677static ssize_t lock_stat_write(struct file *file, const char __user *buf,
678 size_t count, loff_t *ppos)
679{
680 struct lock_class *class;
681 unsigned long idx;
682 char c;
683
684 if (count) {
685 if (get_user(c, buf))
686 return -EFAULT;
687
688 if (c != '0')
689 return count;
690
691 iterate_lock_classes(idx, class) {
692 if (!test_bit(idx, lock_classes_in_use))
693 continue;
694 clear_lock_stats(class);
695 }
696 }
697 return count;
698}
699
700static int lock_stat_release(struct inode *inode, struct file *file)
701{
702 struct seq_file *seq = file->private_data;
703
704 vfree(seq->private);
705 return seq_release(inode, file);
706}
707
708static const struct proc_ops lock_stat_proc_ops = {
709 .proc_open = lock_stat_open,
710 .proc_write = lock_stat_write,
711 .proc_read = seq_read,
712 .proc_lseek = seq_lseek,
713 .proc_release = lock_stat_release,
714};
715#endif /* CONFIG_LOCK_STAT */
716
717static int __init lockdep_proc_init(void)
718{
719 proc_create_seq("lockdep", S_IRUSR, NULL, &lockdep_ops);
720#ifdef CONFIG_PROVE_LOCKING
721 proc_create_seq("lockdep_chains", S_IRUSR, NULL, &lockdep_chains_ops);
722#endif
723 proc_create_single("lockdep_stats", S_IRUSR, NULL, lockdep_stats_show);
724#ifdef CONFIG_LOCK_STAT
725 proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL, &lock_stat_proc_ops);
726#endif
727
728 return 0;
729}
730
731__initcall(lockdep_proc_init);
732