lockdep: Simplify lockdep seqfile code
[linux-2.6.git] / kernel / lockdep_proc.c
1 /*
2  * kernel/lockdep_proc.c
3  *
4  * Runtime locking correctness validator
5  *
6  * Started by Ingo Molnar:
7  *
8  *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
9  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
10  *
11  * Code for /proc/lockdep and /proc/lockdep_stats:
12  *
13  */
14 #include <linux/module.h>
15 #include <linux/proc_fs.h>
16 #include <linux/seq_file.h>
17 #include <linux/kallsyms.h>
18 #include <linux/debug_locks.h>
19 #include <linux/vmalloc.h>
20 #include <linux/sort.h>
21 #include <asm/uaccess.h>
22 #include <asm/div64.h>
23
24 #include "lockdep_internals.h"
25
26 static void *l_next(struct seq_file *m, void *v, loff_t *pos)
27 {
28         return seq_list_next(v, &all_lock_classes, pos);
29 }
30
31 static void *l_start(struct seq_file *m, loff_t *pos)
32 {
33         return seq_list_start_head(&all_lock_classes, *pos);
34 }
35
36 static void l_stop(struct seq_file *m, void *v)
37 {
38 }
39
40 static void print_name(struct seq_file *m, struct lock_class *class)
41 {
42         char str[128];
43         const char *name = class->name;
44
45         if (!name) {
46                 name = __get_key_name(class->key, str);
47                 seq_printf(m, "%s", name);
48         } else{
49                 seq_printf(m, "%s", name);
50                 if (class->name_version > 1)
51                         seq_printf(m, "#%d", class->name_version);
52                 if (class->subclass)
53                         seq_printf(m, "/%d", class->subclass);
54         }
55 }
56
57 static int l_show(struct seq_file *m, void *v)
58 {
59         struct lock_class *class = list_entry(v, struct lock_class, lock_entry);
60         struct lock_list *entry;
61         char usage[LOCK_USAGE_CHARS];
62
63         if (v == &all_lock_classes) {
64                 seq_printf(m, "all lock classes:\n");
65                 return 0;
66         }
67
68         seq_printf(m, "%p", class->key);
69 #ifdef CONFIG_DEBUG_LOCKDEP
70         seq_printf(m, " OPS:%8ld", class->ops);
71 #endif
72 #ifdef CONFIG_PROVE_LOCKING
73         seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));
74         seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
75 #endif
76
77         get_usage_chars(class, usage);
78         seq_printf(m, " %s", usage);
79
80         seq_printf(m, ": ");
81         print_name(m, class);
82         seq_puts(m, "\n");
83
84         list_for_each_entry(entry, &class->locks_after, entry) {
85                 if (entry->distance == 1) {
86                         seq_printf(m, " -> [%p] ", entry->class->key);
87                         print_name(m, entry->class);
88                         seq_puts(m, "\n");
89                 }
90         }
91         seq_puts(m, "\n");
92
93         return 0;
94 }
95
96 static const struct seq_operations lockdep_ops = {
97         .start  = l_start,
98         .next   = l_next,
99         .stop   = l_stop,
100         .show   = l_show,
101 };
102
103 static int lockdep_open(struct inode *inode, struct file *file)
104 {
105         return seq_open(file, &lockdep_ops);
106 }
107
108 static const struct file_operations proc_lockdep_operations = {
109         .open           = lockdep_open,
110         .read           = seq_read,
111         .llseek         = seq_lseek,
112         .release        = seq_release,
113 };
114
115 #ifdef CONFIG_PROVE_LOCKING
116 static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
117 {
118         struct lock_chain *chain;
119
120         (*pos)++;
121
122         if (v == SEQ_START_TOKEN)
123                 chain = m->private;
124         else {
125                 chain = v;
126
127                 if (*pos - 1 < nr_lock_chains)
128                         chain = lock_chains + (*pos - 1);
129                 else
130                         chain = NULL;
131         }
132
133         return chain;
134 }
135
136 static void *lc_start(struct seq_file *m, loff_t *pos)
137 {
138         if (*pos == 0)
139                 return SEQ_START_TOKEN;
140
141         if (*pos - 1 < nr_lock_chains)
142                 return lock_chains + (*pos - 1);
143
144         return NULL;
145 }
146
147 static void lc_stop(struct seq_file *m, void *v)
148 {
149 }
150
151 static int lc_show(struct seq_file *m, void *v)
152 {
153         struct lock_chain *chain = v;
154         struct lock_class *class;
155         int i;
156
157         if (v == SEQ_START_TOKEN) {
158                 seq_printf(m, "all lock chains:\n");
159                 return 0;
160         }
161
162         seq_printf(m, "irq_context: %d\n", chain->irq_context);
163
164         for (i = 0; i < chain->depth; i++) {
165                 class = lock_chain_get_class(chain, i);
166                 if (!class->key)
167                         continue;
168
169                 seq_printf(m, "[%p] ", class->key);
170                 print_name(m, class);
171                 seq_puts(m, "\n");
172         }
173         seq_puts(m, "\n");
174
175         return 0;
176 }
177
178 static const struct seq_operations lockdep_chains_ops = {
179         .start  = lc_start,
180         .next   = lc_next,
181         .stop   = lc_stop,
182         .show   = lc_show,
183 };
184
185 static int lockdep_chains_open(struct inode *inode, struct file *file)
186 {
187         int res = seq_open(file, &lockdep_chains_ops);
188         if (!res) {
189                 struct seq_file *m = file->private_data;
190
191                 if (nr_lock_chains)
192                         m->private = lock_chains;
193                 else
194                         m->private = NULL;
195         }
196         return res;
197 }
198
199 static const struct file_operations proc_lockdep_chains_operations = {
200         .open           = lockdep_chains_open,
201         .read           = seq_read,
202         .llseek         = seq_lseek,
203         .release        = seq_release,
204 };
205 #endif /* CONFIG_PROVE_LOCKING */
206
207 static void lockdep_stats_debug_show(struct seq_file *m)
208 {
209 #ifdef CONFIG_DEBUG_LOCKDEP
210         unsigned int hi1 = debug_atomic_read(&hardirqs_on_events),
211                      hi2 = debug_atomic_read(&hardirqs_off_events),
212                      hr1 = debug_atomic_read(&redundant_hardirqs_on),
213                      hr2 = debug_atomic_read(&redundant_hardirqs_off),
214                      si1 = debug_atomic_read(&softirqs_on_events),
215                      si2 = debug_atomic_read(&softirqs_off_events),
216                      sr1 = debug_atomic_read(&redundant_softirqs_on),
217                      sr2 = debug_atomic_read(&redundant_softirqs_off);
218
219         seq_printf(m, " chain lookup misses:           %11u\n",
220                 debug_atomic_read(&chain_lookup_misses));
221         seq_printf(m, " chain lookup hits:             %11u\n",
222                 debug_atomic_read(&chain_lookup_hits));
223         seq_printf(m, " cyclic checks:                 %11u\n",
224                 debug_atomic_read(&nr_cyclic_checks));
225         seq_printf(m, " cyclic-check recursions:       %11u\n",
226                 debug_atomic_read(&nr_cyclic_check_recursions));
227         seq_printf(m, " find-mask forwards checks:     %11u\n",
228                 debug_atomic_read(&nr_find_usage_forwards_checks));
229         seq_printf(m, " find-mask forwards recursions: %11u\n",
230                 debug_atomic_read(&nr_find_usage_forwards_recursions));
231         seq_printf(m, " find-mask backwards checks:    %11u\n",
232                 debug_atomic_read(&nr_find_usage_backwards_checks));
233         seq_printf(m, " find-mask backwards recursions:%11u\n",
234                 debug_atomic_read(&nr_find_usage_backwards_recursions));
235
236         seq_printf(m, " hardirq on events:             %11u\n", hi1);
237         seq_printf(m, " hardirq off events:            %11u\n", hi2);
238         seq_printf(m, " redundant hardirq ons:         %11u\n", hr1);
239         seq_printf(m, " redundant hardirq offs:        %11u\n", hr2);
240         seq_printf(m, " softirq on events:             %11u\n", si1);
241         seq_printf(m, " softirq off events:            %11u\n", si2);
242         seq_printf(m, " redundant softirq ons:         %11u\n", sr1);
243         seq_printf(m, " redundant softirq offs:        %11u\n", sr2);
244 #endif
245 }
246
247 static int lockdep_stats_show(struct seq_file *m, void *v)
248 {
249         struct lock_class *class;
250         unsigned long nr_unused = 0, nr_uncategorized = 0,
251                       nr_irq_safe = 0, nr_irq_unsafe = 0,
252                       nr_softirq_safe = 0, nr_softirq_unsafe = 0,
253                       nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
254                       nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
255                       nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
256                       nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
257                       sum_forward_deps = 0, factor = 0;
258
259         list_for_each_entry(class, &all_lock_classes, lock_entry) {
260
261                 if (class->usage_mask == 0)
262                         nr_unused++;
263                 if (class->usage_mask == LOCKF_USED)
264                         nr_uncategorized++;
265                 if (class->usage_mask & LOCKF_USED_IN_IRQ)
266                         nr_irq_safe++;
267                 if (class->usage_mask & LOCKF_ENABLED_IRQ)
268                         nr_irq_unsafe++;
269                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
270                         nr_softirq_safe++;
271                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
272                         nr_softirq_unsafe++;
273                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
274                         nr_hardirq_safe++;
275                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
276                         nr_hardirq_unsafe++;
277                 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
278                         nr_irq_read_safe++;
279                 if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
280                         nr_irq_read_unsafe++;
281                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
282                         nr_softirq_read_safe++;
283                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
284                         nr_softirq_read_unsafe++;
285                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
286                         nr_hardirq_read_safe++;
287                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
288                         nr_hardirq_read_unsafe++;
289
290 #ifdef CONFIG_PROVE_LOCKING
291                 sum_forward_deps += lockdep_count_forward_deps(class);
292 #endif
293         }
294 #ifdef CONFIG_DEBUG_LOCKDEP
295         DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
296 #endif
297         seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",
298                         nr_lock_classes, MAX_LOCKDEP_KEYS);
299         seq_printf(m, " direct dependencies:           %11lu [max: %lu]\n",
300                         nr_list_entries, MAX_LOCKDEP_ENTRIES);
301         seq_printf(m, " indirect dependencies:         %11lu\n",
302                         sum_forward_deps);
303
304         /*
305          * Total number of dependencies:
306          *
307          * All irq-safe locks may nest inside irq-unsafe locks,
308          * plus all the other known dependencies:
309          */
310         seq_printf(m, " all direct dependencies:       %11lu\n",
311                         nr_irq_unsafe * nr_irq_safe +
312                         nr_hardirq_unsafe * nr_hardirq_safe +
313                         nr_list_entries);
314
315         /*
316          * Estimated factor between direct and indirect
317          * dependencies:
318          */
319         if (nr_list_entries)
320                 factor = sum_forward_deps / nr_list_entries;
321
322 #ifdef CONFIG_PROVE_LOCKING
323         seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
324                         nr_lock_chains, MAX_LOCKDEP_CHAINS);
325         seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",
326                         nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
327 #endif
328
329 #ifdef CONFIG_TRACE_IRQFLAGS
330         seq_printf(m, " in-hardirq chains:             %11u\n",
331                         nr_hardirq_chains);
332         seq_printf(m, " in-softirq chains:             %11u\n",
333                         nr_softirq_chains);
334 #endif
335         seq_printf(m, " in-process chains:             %11u\n",
336                         nr_process_chains);
337         seq_printf(m, " stack-trace entries:           %11lu [max: %lu]\n",
338                         nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
339         seq_printf(m, " combined max dependencies:     %11u\n",
340                         (nr_hardirq_chains + 1) *
341                         (nr_softirq_chains + 1) *
342                         (nr_process_chains + 1)
343         );
344         seq_printf(m, " hardirq-safe locks:            %11lu\n",
345                         nr_hardirq_safe);
346         seq_printf(m, " hardirq-unsafe locks:          %11lu\n",
347                         nr_hardirq_unsafe);
348         seq_printf(m, " softirq-safe locks:            %11lu\n",
349                         nr_softirq_safe);
350         seq_printf(m, " softirq-unsafe locks:          %11lu\n",
351                         nr_softirq_unsafe);
352         seq_printf(m, " irq-safe locks:                %11lu\n",
353                         nr_irq_safe);
354         seq_printf(m, " irq-unsafe locks:              %11lu\n",
355                         nr_irq_unsafe);
356
357         seq_printf(m, " hardirq-read-safe locks:       %11lu\n",
358                         nr_hardirq_read_safe);
359         seq_printf(m, " hardirq-read-unsafe locks:     %11lu\n",
360                         nr_hardirq_read_unsafe);
361         seq_printf(m, " softirq-read-safe locks:       %11lu\n",
362                         nr_softirq_read_safe);
363         seq_printf(m, " softirq-read-unsafe locks:     %11lu\n",
364                         nr_softirq_read_unsafe);
365         seq_printf(m, " irq-read-safe locks:           %11lu\n",
366                         nr_irq_read_safe);
367         seq_printf(m, " irq-read-unsafe locks:         %11lu\n",
368                         nr_irq_read_unsafe);
369
370         seq_printf(m, " uncategorized locks:           %11lu\n",
371                         nr_uncategorized);
372         seq_printf(m, " unused locks:                  %11lu\n",
373                         nr_unused);
374         seq_printf(m, " max locking depth:             %11u\n",
375                         max_lockdep_depth);
376         seq_printf(m, " max recursion depth:           %11u\n",
377                         max_recursion_depth);
378 #ifdef CONFIG_PROVE_LOCKING
379         seq_printf(m, " max bfs queue depth:           %11u\n",
380                         max_bfs_queue_depth);
381 #endif
382         lockdep_stats_debug_show(m);
383         seq_printf(m, " debug_locks:                   %11u\n",
384                         debug_locks);
385
386         return 0;
387 }
388
389 static int lockdep_stats_open(struct inode *inode, struct file *file)
390 {
391         return single_open(file, lockdep_stats_show, NULL);
392 }
393
394 static const struct file_operations proc_lockdep_stats_operations = {
395         .open           = lockdep_stats_open,
396         .read           = seq_read,
397         .llseek         = seq_lseek,
398         .release        = single_release,
399 };
400
401 #ifdef CONFIG_LOCK_STAT
402
403 struct lock_stat_data {
404         struct lock_class *class;
405         struct lock_class_stats stats;
406 };
407
408 struct lock_stat_seq {
409         struct lock_stat_data *iter;
410         struct lock_stat_data *iter_end;
411         struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
412 };
413
414 /*
415  * sort on absolute number of contentions
416  */
417 static int lock_stat_cmp(const void *l, const void *r)
418 {
419         const struct lock_stat_data *dl = l, *dr = r;
420         unsigned long nl, nr;
421
422         nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
423         nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
424
425         return nr - nl;
426 }
427
428 static void seq_line(struct seq_file *m, char c, int offset, int length)
429 {
430         int i;
431
432         for (i = 0; i < offset; i++)
433                 seq_puts(m, " ");
434         for (i = 0; i < length; i++)
435                 seq_printf(m, "%c", c);
436         seq_puts(m, "\n");
437 }
438
439 static void snprint_time(char *buf, size_t bufsiz, s64 nr)
440 {
441         s64 div;
442         s32 rem;
443
444         nr += 5; /* for display rounding */
445         div = div_s64_rem(nr, 1000, &rem);
446         snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
447 }
448
449 static void seq_time(struct seq_file *m, s64 time)
450 {
451         char num[15];
452
453         snprint_time(num, sizeof(num), time);
454         seq_printf(m, " %14s", num);
455 }
456
457 static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
458 {
459         seq_printf(m, "%14lu", lt->nr);
460         seq_time(m, lt->min);
461         seq_time(m, lt->max);
462         seq_time(m, lt->total);
463 }
464
465 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
466 {
467         char name[39];
468         struct lock_class *class;
469         struct lock_class_stats *stats;
470         int i, namelen;
471
472         class = data->class;
473         stats = &data->stats;
474
475         namelen = 38;
476         if (class->name_version > 1)
477                 namelen -= 2; /* XXX truncates versions > 9 */
478         if (class->subclass)
479                 namelen -= 2;
480
481         if (!class->name) {
482                 char str[KSYM_NAME_LEN];
483                 const char *key_name;
484
485                 key_name = __get_key_name(class->key, str);
486                 snprintf(name, namelen, "%s", key_name);
487         } else {
488                 snprintf(name, namelen, "%s", class->name);
489         }
490         namelen = strlen(name);
491         if (class->name_version > 1) {
492                 snprintf(name+namelen, 3, "#%d", class->name_version);
493                 namelen += 2;
494         }
495         if (class->subclass) {
496                 snprintf(name+namelen, 3, "/%d", class->subclass);
497                 namelen += 2;
498         }
499
500         if (stats->write_holdtime.nr) {
501                 if (stats->read_holdtime.nr)
502                         seq_printf(m, "%38s-W:", name);
503                 else
504                         seq_printf(m, "%40s:", name);
505
506                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
507                 seq_lock_time(m, &stats->write_waittime);
508                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
509                 seq_lock_time(m, &stats->write_holdtime);
510                 seq_puts(m, "\n");
511         }
512
513         if (stats->read_holdtime.nr) {
514                 seq_printf(m, "%38s-R:", name);
515                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
516                 seq_lock_time(m, &stats->read_waittime);
517                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
518                 seq_lock_time(m, &stats->read_holdtime);
519                 seq_puts(m, "\n");
520         }
521
522         if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
523                 return;
524
525         if (stats->read_holdtime.nr)
526                 namelen += 2;
527
528         for (i = 0; i < LOCKSTAT_POINTS; i++) {
529                 char sym[KSYM_SYMBOL_LEN];
530                 char ip[32];
531
532                 if (class->contention_point[i] == 0)
533                         break;
534
535                 if (!i)
536                         seq_line(m, '-', 40-namelen, namelen);
537
538                 sprint_symbol(sym, class->contention_point[i]);
539                 snprintf(ip, sizeof(ip), "[<%p>]",
540                                 (void *)class->contention_point[i]);
541                 seq_printf(m, "%40s %14lu %29s %s\n", name,
542                                 stats->contention_point[i],
543                                 ip, sym);
544         }
545         for (i = 0; i < LOCKSTAT_POINTS; i++) {
546                 char sym[KSYM_SYMBOL_LEN];
547                 char ip[32];
548
549                 if (class->contending_point[i] == 0)
550                         break;
551
552                 if (!i)
553                         seq_line(m, '-', 40-namelen, namelen);
554
555                 sprint_symbol(sym, class->contending_point[i]);
556                 snprintf(ip, sizeof(ip), "[<%p>]",
557                                 (void *)class->contending_point[i]);
558                 seq_printf(m, "%40s %14lu %29s %s\n", name,
559                                 stats->contending_point[i],
560                                 ip, sym);
561         }
562         if (i) {
563                 seq_puts(m, "\n");
564                 seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
565                 seq_puts(m, "\n");
566         }
567 }
568
569 static void seq_header(struct seq_file *m)
570 {
571         seq_printf(m, "lock_stat version 0.3\n");
572
573         if (unlikely(!debug_locks))
574                 seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
575
576         seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
577         seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
578                         "%14s %14s\n",
579                         "class name",
580                         "con-bounces",
581                         "contentions",
582                         "waittime-min",
583                         "waittime-max",
584                         "waittime-total",
585                         "acq-bounces",
586                         "acquisitions",
587                         "holdtime-min",
588                         "holdtime-max",
589                         "holdtime-total");
590         seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
591         seq_printf(m, "\n");
592 }
593
594 static void *ls_start(struct seq_file *m, loff_t *pos)
595 {
596         struct lock_stat_seq *data = m->private;
597
598         if (*pos == 0)
599                 return SEQ_START_TOKEN;
600
601         data->iter = data->stats + (*pos - 1);
602         if (data->iter >= data->iter_end)
603                 data->iter = NULL;
604
605         return data->iter;
606 }
607
608 static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
609 {
610         struct lock_stat_seq *data = m->private;
611
612         (*pos)++;
613
614         if (v == SEQ_START_TOKEN)
615                 data->iter = data->stats;
616         else {
617                 data->iter = v;
618                 data->iter++;
619         }
620
621         if (data->iter == data->iter_end)
622                 data->iter = NULL;
623
624         return data->iter;
625 }
626
627 static void ls_stop(struct seq_file *m, void *v)
628 {
629 }
630
631 static int ls_show(struct seq_file *m, void *v)
632 {
633         if (v == SEQ_START_TOKEN)
634                 seq_header(m);
635         else
636                 seq_stats(m, v);
637
638         return 0;
639 }
640
641 static struct seq_operations lockstat_ops = {
642         .start  = ls_start,
643         .next   = ls_next,
644         .stop   = ls_stop,
645         .show   = ls_show,
646 };
647
648 static int lock_stat_open(struct inode *inode, struct file *file)
649 {
650         int res;
651         struct lock_class *class;
652         struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
653
654         if (!data)
655                 return -ENOMEM;
656
657         res = seq_open(file, &lockstat_ops);
658         if (!res) {
659                 struct lock_stat_data *iter = data->stats;
660                 struct seq_file *m = file->private_data;
661
662                 data->iter = iter;
663                 list_for_each_entry(class, &all_lock_classes, lock_entry) {
664                         iter->class = class;
665                         iter->stats = lock_stats(class);
666                         iter++;
667                 }
668                 data->iter_end = iter;
669
670                 sort(data->stats, data->iter_end - data->iter,
671                                 sizeof(struct lock_stat_data),
672                                 lock_stat_cmp, NULL);
673
674                 m->private = data;
675         } else
676                 vfree(data);
677
678         return res;
679 }
680
681 static ssize_t lock_stat_write(struct file *file, const char __user *buf,
682                                size_t count, loff_t *ppos)
683 {
684         struct lock_class *class;
685         char c;
686
687         if (count) {
688                 if (get_user(c, buf))
689                         return -EFAULT;
690
691                 if (c != '0')
692                         return count;
693
694                 list_for_each_entry(class, &all_lock_classes, lock_entry)
695                         clear_lock_stats(class);
696         }
697         return count;
698 }
699
700 static 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         seq->private = NULL;
706         return seq_release(inode, file);
707 }
708
709 static const struct file_operations proc_lock_stat_operations = {
710         .open           = lock_stat_open,
711         .write          = lock_stat_write,
712         .read           = seq_read,
713         .llseek         = seq_lseek,
714         .release        = lock_stat_release,
715 };
716 #endif /* CONFIG_LOCK_STAT */
717
718 static int __init lockdep_proc_init(void)
719 {
720         proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
721 #ifdef CONFIG_PROVE_LOCKING
722         proc_create("lockdep_chains", S_IRUSR, NULL,
723                     &proc_lockdep_chains_operations);
724 #endif
725         proc_create("lockdep_stats", S_IRUSR, NULL,
726                     &proc_lockdep_stats_operations);
727
728 #ifdef CONFIG_LOCK_STAT
729         proc_create("lock_stat", S_IRUSR, NULL, &proc_lock_stat_operations);
730 #endif
731
732         return 0;
733 }
734
735 __initcall(lockdep_proc_init);
736