lockdep: Simplify lockdep_chains seqfile code
[safe/jmp/linux-2.6] / 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_start(struct seq_file *m, loff_t *pos)
117 {
118         if (*pos == 0)
119                 return SEQ_START_TOKEN;
120
121         if (*pos - 1 < nr_lock_chains)
122                 return lock_chains + (*pos - 1);
123
124         return NULL;
125 }
126
127 static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
128 {
129         (*pos)++;
130         return lc_start(m, pos);
131 }
132
133 static void lc_stop(struct seq_file *m, void *v)
134 {
135 }
136
137 static int lc_show(struct seq_file *m, void *v)
138 {
139         struct lock_chain *chain = v;
140         struct lock_class *class;
141         int i;
142
143         if (v == SEQ_START_TOKEN) {
144                 seq_printf(m, "all lock chains:\n");
145                 return 0;
146         }
147
148         seq_printf(m, "irq_context: %d\n", chain->irq_context);
149
150         for (i = 0; i < chain->depth; i++) {
151                 class = lock_chain_get_class(chain, i);
152                 if (!class->key)
153                         continue;
154
155                 seq_printf(m, "[%p] ", class->key);
156                 print_name(m, class);
157                 seq_puts(m, "\n");
158         }
159         seq_puts(m, "\n");
160
161         return 0;
162 }
163
164 static const struct seq_operations lockdep_chains_ops = {
165         .start  = lc_start,
166         .next   = lc_next,
167         .stop   = lc_stop,
168         .show   = lc_show,
169 };
170
171 static int lockdep_chains_open(struct inode *inode, struct file *file)
172 {
173         return seq_open(file, &lockdep_chains_ops);
174 }
175
176 static const struct file_operations proc_lockdep_chains_operations = {
177         .open           = lockdep_chains_open,
178         .read           = seq_read,
179         .llseek         = seq_lseek,
180         .release        = seq_release,
181 };
182 #endif /* CONFIG_PROVE_LOCKING */
183
184 static void lockdep_stats_debug_show(struct seq_file *m)
185 {
186 #ifdef CONFIG_DEBUG_LOCKDEP
187         unsigned int hi1 = debug_atomic_read(&hardirqs_on_events),
188                      hi2 = debug_atomic_read(&hardirqs_off_events),
189                      hr1 = debug_atomic_read(&redundant_hardirqs_on),
190                      hr2 = debug_atomic_read(&redundant_hardirqs_off),
191                      si1 = debug_atomic_read(&softirqs_on_events),
192                      si2 = debug_atomic_read(&softirqs_off_events),
193                      sr1 = debug_atomic_read(&redundant_softirqs_on),
194                      sr2 = debug_atomic_read(&redundant_softirqs_off);
195
196         seq_printf(m, " chain lookup misses:           %11u\n",
197                 debug_atomic_read(&chain_lookup_misses));
198         seq_printf(m, " chain lookup hits:             %11u\n",
199                 debug_atomic_read(&chain_lookup_hits));
200         seq_printf(m, " cyclic checks:                 %11u\n",
201                 debug_atomic_read(&nr_cyclic_checks));
202         seq_printf(m, " cyclic-check recursions:       %11u\n",
203                 debug_atomic_read(&nr_cyclic_check_recursions));
204         seq_printf(m, " find-mask forwards checks:     %11u\n",
205                 debug_atomic_read(&nr_find_usage_forwards_checks));
206         seq_printf(m, " find-mask forwards recursions: %11u\n",
207                 debug_atomic_read(&nr_find_usage_forwards_recursions));
208         seq_printf(m, " find-mask backwards checks:    %11u\n",
209                 debug_atomic_read(&nr_find_usage_backwards_checks));
210         seq_printf(m, " find-mask backwards recursions:%11u\n",
211                 debug_atomic_read(&nr_find_usage_backwards_recursions));
212
213         seq_printf(m, " hardirq on events:             %11u\n", hi1);
214         seq_printf(m, " hardirq off events:            %11u\n", hi2);
215         seq_printf(m, " redundant hardirq ons:         %11u\n", hr1);
216         seq_printf(m, " redundant hardirq offs:        %11u\n", hr2);
217         seq_printf(m, " softirq on events:             %11u\n", si1);
218         seq_printf(m, " softirq off events:            %11u\n", si2);
219         seq_printf(m, " redundant softirq ons:         %11u\n", sr1);
220         seq_printf(m, " redundant softirq offs:        %11u\n", sr2);
221 #endif
222 }
223
224 static int lockdep_stats_show(struct seq_file *m, void *v)
225 {
226         struct lock_class *class;
227         unsigned long nr_unused = 0, nr_uncategorized = 0,
228                       nr_irq_safe = 0, nr_irq_unsafe = 0,
229                       nr_softirq_safe = 0, nr_softirq_unsafe = 0,
230                       nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
231                       nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
232                       nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
233                       nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
234                       sum_forward_deps = 0, factor = 0;
235
236         list_for_each_entry(class, &all_lock_classes, lock_entry) {
237
238                 if (class->usage_mask == 0)
239                         nr_unused++;
240                 if (class->usage_mask == LOCKF_USED)
241                         nr_uncategorized++;
242                 if (class->usage_mask & LOCKF_USED_IN_IRQ)
243                         nr_irq_safe++;
244                 if (class->usage_mask & LOCKF_ENABLED_IRQ)
245                         nr_irq_unsafe++;
246                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
247                         nr_softirq_safe++;
248                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
249                         nr_softirq_unsafe++;
250                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
251                         nr_hardirq_safe++;
252                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
253                         nr_hardirq_unsafe++;
254                 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
255                         nr_irq_read_safe++;
256                 if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
257                         nr_irq_read_unsafe++;
258                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
259                         nr_softirq_read_safe++;
260                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
261                         nr_softirq_read_unsafe++;
262                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
263                         nr_hardirq_read_safe++;
264                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
265                         nr_hardirq_read_unsafe++;
266
267 #ifdef CONFIG_PROVE_LOCKING
268                 sum_forward_deps += lockdep_count_forward_deps(class);
269 #endif
270         }
271 #ifdef CONFIG_DEBUG_LOCKDEP
272         DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
273 #endif
274         seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",
275                         nr_lock_classes, MAX_LOCKDEP_KEYS);
276         seq_printf(m, " direct dependencies:           %11lu [max: %lu]\n",
277                         nr_list_entries, MAX_LOCKDEP_ENTRIES);
278         seq_printf(m, " indirect dependencies:         %11lu\n",
279                         sum_forward_deps);
280
281         /*
282          * Total number of dependencies:
283          *
284          * All irq-safe locks may nest inside irq-unsafe locks,
285          * plus all the other known dependencies:
286          */
287         seq_printf(m, " all direct dependencies:       %11lu\n",
288                         nr_irq_unsafe * nr_irq_safe +
289                         nr_hardirq_unsafe * nr_hardirq_safe +
290                         nr_list_entries);
291
292         /*
293          * Estimated factor between direct and indirect
294          * dependencies:
295          */
296         if (nr_list_entries)
297                 factor = sum_forward_deps / nr_list_entries;
298
299 #ifdef CONFIG_PROVE_LOCKING
300         seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
301                         nr_lock_chains, MAX_LOCKDEP_CHAINS);
302         seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",
303                         nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
304 #endif
305
306 #ifdef CONFIG_TRACE_IRQFLAGS
307         seq_printf(m, " in-hardirq chains:             %11u\n",
308                         nr_hardirq_chains);
309         seq_printf(m, " in-softirq chains:             %11u\n",
310                         nr_softirq_chains);
311 #endif
312         seq_printf(m, " in-process chains:             %11u\n",
313                         nr_process_chains);
314         seq_printf(m, " stack-trace entries:           %11lu [max: %lu]\n",
315                         nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
316         seq_printf(m, " combined max dependencies:     %11u\n",
317                         (nr_hardirq_chains + 1) *
318                         (nr_softirq_chains + 1) *
319                         (nr_process_chains + 1)
320         );
321         seq_printf(m, " hardirq-safe locks:            %11lu\n",
322                         nr_hardirq_safe);
323         seq_printf(m, " hardirq-unsafe locks:          %11lu\n",
324                         nr_hardirq_unsafe);
325         seq_printf(m, " softirq-safe locks:            %11lu\n",
326                         nr_softirq_safe);
327         seq_printf(m, " softirq-unsafe locks:          %11lu\n",
328                         nr_softirq_unsafe);
329         seq_printf(m, " irq-safe locks:                %11lu\n",
330                         nr_irq_safe);
331         seq_printf(m, " irq-unsafe locks:              %11lu\n",
332                         nr_irq_unsafe);
333
334         seq_printf(m, " hardirq-read-safe locks:       %11lu\n",
335                         nr_hardirq_read_safe);
336         seq_printf(m, " hardirq-read-unsafe locks:     %11lu\n",
337                         nr_hardirq_read_unsafe);
338         seq_printf(m, " softirq-read-safe locks:       %11lu\n",
339                         nr_softirq_read_safe);
340         seq_printf(m, " softirq-read-unsafe locks:     %11lu\n",
341                         nr_softirq_read_unsafe);
342         seq_printf(m, " irq-read-safe locks:           %11lu\n",
343                         nr_irq_read_safe);
344         seq_printf(m, " irq-read-unsafe locks:         %11lu\n",
345                         nr_irq_read_unsafe);
346
347         seq_printf(m, " uncategorized locks:           %11lu\n",
348                         nr_uncategorized);
349         seq_printf(m, " unused locks:                  %11lu\n",
350                         nr_unused);
351         seq_printf(m, " max locking depth:             %11u\n",
352                         max_lockdep_depth);
353         seq_printf(m, " max recursion depth:           %11u\n",
354                         max_recursion_depth);
355 #ifdef CONFIG_PROVE_LOCKING
356         seq_printf(m, " max bfs queue depth:           %11u\n",
357                         max_bfs_queue_depth);
358 #endif
359         lockdep_stats_debug_show(m);
360         seq_printf(m, " debug_locks:                   %11u\n",
361                         debug_locks);
362
363         return 0;
364 }
365
366 static int lockdep_stats_open(struct inode *inode, struct file *file)
367 {
368         return single_open(file, lockdep_stats_show, NULL);
369 }
370
371 static const struct file_operations proc_lockdep_stats_operations = {
372         .open           = lockdep_stats_open,
373         .read           = seq_read,
374         .llseek         = seq_lseek,
375         .release        = single_release,
376 };
377
378 #ifdef CONFIG_LOCK_STAT
379
380 struct lock_stat_data {
381         struct lock_class *class;
382         struct lock_class_stats stats;
383 };
384
385 struct lock_stat_seq {
386         struct lock_stat_data *iter;
387         struct lock_stat_data *iter_end;
388         struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
389 };
390
391 /*
392  * sort on absolute number of contentions
393  */
394 static int lock_stat_cmp(const void *l, const void *r)
395 {
396         const struct lock_stat_data *dl = l, *dr = r;
397         unsigned long nl, nr;
398
399         nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
400         nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
401
402         return nr - nl;
403 }
404
405 static void seq_line(struct seq_file *m, char c, int offset, int length)
406 {
407         int i;
408
409         for (i = 0; i < offset; i++)
410                 seq_puts(m, " ");
411         for (i = 0; i < length; i++)
412                 seq_printf(m, "%c", c);
413         seq_puts(m, "\n");
414 }
415
416 static void snprint_time(char *buf, size_t bufsiz, s64 nr)
417 {
418         s64 div;
419         s32 rem;
420
421         nr += 5; /* for display rounding */
422         div = div_s64_rem(nr, 1000, &rem);
423         snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
424 }
425
426 static void seq_time(struct seq_file *m, s64 time)
427 {
428         char num[15];
429
430         snprint_time(num, sizeof(num), time);
431         seq_printf(m, " %14s", num);
432 }
433
434 static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
435 {
436         seq_printf(m, "%14lu", lt->nr);
437         seq_time(m, lt->min);
438         seq_time(m, lt->max);
439         seq_time(m, lt->total);
440 }
441
442 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
443 {
444         char name[39];
445         struct lock_class *class;
446         struct lock_class_stats *stats;
447         int i, namelen;
448
449         class = data->class;
450         stats = &data->stats;
451
452         namelen = 38;
453         if (class->name_version > 1)
454                 namelen -= 2; /* XXX truncates versions > 9 */
455         if (class->subclass)
456                 namelen -= 2;
457
458         if (!class->name) {
459                 char str[KSYM_NAME_LEN];
460                 const char *key_name;
461
462                 key_name = __get_key_name(class->key, str);
463                 snprintf(name, namelen, "%s", key_name);
464         } else {
465                 snprintf(name, namelen, "%s", class->name);
466         }
467         namelen = strlen(name);
468         if (class->name_version > 1) {
469                 snprintf(name+namelen, 3, "#%d", class->name_version);
470                 namelen += 2;
471         }
472         if (class->subclass) {
473                 snprintf(name+namelen, 3, "/%d", class->subclass);
474                 namelen += 2;
475         }
476
477         if (stats->write_holdtime.nr) {
478                 if (stats->read_holdtime.nr)
479                         seq_printf(m, "%38s-W:", name);
480                 else
481                         seq_printf(m, "%40s:", name);
482
483                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
484                 seq_lock_time(m, &stats->write_waittime);
485                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
486                 seq_lock_time(m, &stats->write_holdtime);
487                 seq_puts(m, "\n");
488         }
489
490         if (stats->read_holdtime.nr) {
491                 seq_printf(m, "%38s-R:", name);
492                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
493                 seq_lock_time(m, &stats->read_waittime);
494                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
495                 seq_lock_time(m, &stats->read_holdtime);
496                 seq_puts(m, "\n");
497         }
498
499         if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
500                 return;
501
502         if (stats->read_holdtime.nr)
503                 namelen += 2;
504
505         for (i = 0; i < LOCKSTAT_POINTS; i++) {
506                 char sym[KSYM_SYMBOL_LEN];
507                 char ip[32];
508
509                 if (class->contention_point[i] == 0)
510                         break;
511
512                 if (!i)
513                         seq_line(m, '-', 40-namelen, namelen);
514
515                 sprint_symbol(sym, class->contention_point[i]);
516                 snprintf(ip, sizeof(ip), "[<%p>]",
517                                 (void *)class->contention_point[i]);
518                 seq_printf(m, "%40s %14lu %29s %s\n", name,
519                                 stats->contention_point[i],
520                                 ip, sym);
521         }
522         for (i = 0; i < LOCKSTAT_POINTS; i++) {
523                 char sym[KSYM_SYMBOL_LEN];
524                 char ip[32];
525
526                 if (class->contending_point[i] == 0)
527                         break;
528
529                 if (!i)
530                         seq_line(m, '-', 40-namelen, namelen);
531
532                 sprint_symbol(sym, class->contending_point[i]);
533                 snprintf(ip, sizeof(ip), "[<%p>]",
534                                 (void *)class->contending_point[i]);
535                 seq_printf(m, "%40s %14lu %29s %s\n", name,
536                                 stats->contending_point[i],
537                                 ip, sym);
538         }
539         if (i) {
540                 seq_puts(m, "\n");
541                 seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
542                 seq_puts(m, "\n");
543         }
544 }
545
546 static void seq_header(struct seq_file *m)
547 {
548         seq_printf(m, "lock_stat version 0.3\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 + 10 * (14 + 1));
554         seq_printf(m, "%40s %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                         "acq-bounces",
563                         "acquisitions",
564                         "holdtime-min",
565                         "holdtime-max",
566                         "holdtime-total");
567         seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
568         seq_printf(m, "\n");
569 }
570
571 static void *ls_start(struct seq_file *m, loff_t *pos)
572 {
573         struct lock_stat_seq *data = m->private;
574
575         if (*pos == 0)
576                 return SEQ_START_TOKEN;
577
578         data->iter = data->stats + (*pos - 1);
579         if (data->iter >= data->iter_end)
580                 data->iter = NULL;
581
582         return data->iter;
583 }
584
585 static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
586 {
587         struct lock_stat_seq *data = m->private;
588
589         (*pos)++;
590
591         if (v == SEQ_START_TOKEN)
592                 data->iter = data->stats;
593         else {
594                 data->iter = v;
595                 data->iter++;
596         }
597
598         if (data->iter == data->iter_end)
599                 data->iter = NULL;
600
601         return data->iter;
602 }
603
604 static void ls_stop(struct seq_file *m, void *v)
605 {
606 }
607
608 static int ls_show(struct seq_file *m, void *v)
609 {
610         if (v == SEQ_START_TOKEN)
611                 seq_header(m);
612         else
613                 seq_stats(m, v);
614
615         return 0;
616 }
617
618 static struct seq_operations lockstat_ops = {
619         .start  = ls_start,
620         .next   = ls_next,
621         .stop   = ls_stop,
622         .show   = ls_show,
623 };
624
625 static int lock_stat_open(struct inode *inode, struct file *file)
626 {
627         int res;
628         struct lock_class *class;
629         struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
630
631         if (!data)
632                 return -ENOMEM;
633
634         res = seq_open(file, &lockstat_ops);
635         if (!res) {
636                 struct lock_stat_data *iter = data->stats;
637                 struct seq_file *m = file->private_data;
638
639                 data->iter = iter;
640                 list_for_each_entry(class, &all_lock_classes, lock_entry) {
641                         iter->class = class;
642                         iter->stats = lock_stats(class);
643                         iter++;
644                 }
645                 data->iter_end = iter;
646
647                 sort(data->stats, data->iter_end - data->iter,
648                                 sizeof(struct lock_stat_data),
649                                 lock_stat_cmp, NULL);
650
651                 m->private = data;
652         } else
653                 vfree(data);
654
655         return res;
656 }
657
658 static ssize_t lock_stat_write(struct file *file, const char __user *buf,
659                                size_t count, loff_t *ppos)
660 {
661         struct lock_class *class;
662         char c;
663
664         if (count) {
665                 if (get_user(c, buf))
666                         return -EFAULT;
667
668                 if (c != '0')
669                         return count;
670
671                 list_for_each_entry(class, &all_lock_classes, lock_entry)
672                         clear_lock_stats(class);
673         }
674         return count;
675 }
676
677 static int lock_stat_release(struct inode *inode, struct file *file)
678 {
679         struct seq_file *seq = file->private_data;
680
681         vfree(seq->private);
682         seq->private = NULL;
683         return seq_release(inode, file);
684 }
685
686 static const struct file_operations proc_lock_stat_operations = {
687         .open           = lock_stat_open,
688         .write          = lock_stat_write,
689         .read           = seq_read,
690         .llseek         = seq_lseek,
691         .release        = lock_stat_release,
692 };
693 #endif /* CONFIG_LOCK_STAT */
694
695 static int __init lockdep_proc_init(void)
696 {
697         proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
698 #ifdef CONFIG_PROVE_LOCKING
699         proc_create("lockdep_chains", S_IRUSR, NULL,
700                     &proc_lockdep_chains_operations);
701 #endif
702         proc_create("lockdep_stats", S_IRUSR, NULL,
703                     &proc_lockdep_stats_operations);
704
705 #ifdef CONFIG_LOCK_STAT
706         proc_create("lock_stat", S_IRUSR, NULL, &proc_lock_stat_operations);
707 #endif
708
709         return 0;
710 }
711
712 __initcall(lockdep_proc_init);
713