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
l_next(struct seq_file * m,void * v,loff_t * pos)38 static 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
l_start(struct seq_file * m,loff_t * pos)47 static 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
l_stop(struct seq_file * m,void * v)56 static void l_stop(struct seq_file *m, void *v)
57 {
58 }
59
print_name(struct seq_file * m,struct lock_class * class)60 static 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
l_show(struct seq_file * m,void * v)77 static 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
120 static 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
lc_start(struct seq_file * m,loff_t * pos)128 static 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
lc_next(struct seq_file * m,void * v,loff_t * pos)139 static 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
lc_stop(struct seq_file * m,void * v)145 static void lc_stop(struct seq_file *m, void *v)
146 {
147 }
148
lc_show(struct seq_file * m,void * v)149 static 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
185 static 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
lockdep_stats_debug_show(struct seq_file * m)193 static 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
lockdep_stats_show(struct seq_file * m,void * v)231 static 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
396 struct lock_stat_data {
397 struct lock_class *class;
398 struct lock_class_stats stats;
399 };
400
401 struct 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 */
lock_stat_cmp(const void * l,const void * r)409 static 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
seq_line(struct seq_file * m,char c,int offset,int length)420 static 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
snprint_time(char * buf,size_t bufsiz,s64 nr)431 static 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
seq_time(struct seq_file * m,s64 time)441 static 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
seq_lock_time(struct seq_file * m,struct lock_time * lt)449 static 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
seq_stats(struct seq_file * m,struct lock_stat_data * data)458 static 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
seq_header(struct seq_file * m)570 static 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
ls_start(struct seq_file * m,loff_t * pos)597 static 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
ls_next(struct seq_file * m,void * v,loff_t * pos)612 static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
613 {
614 (*pos)++;
615 return ls_start(m, pos);
616 }
617
ls_stop(struct seq_file * m,void * v)618 static void ls_stop(struct seq_file *m, void *v)
619 {
620 }
621
ls_show(struct seq_file * m,void * v)622 static 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
632 static const struct seq_operations lockstat_ops = {
633 .start = ls_start,
634 .next = ls_next,
635 .stop = ls_stop,
636 .show = ls_show,
637 };
638
lock_stat_open(struct inode * inode,struct file * file)639 static 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
lock_stat_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)675 static 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
lock_stat_release(struct inode * inode,struct file * file)698 static 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
706 static 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
lockdep_proc_init(void)715 static 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
731