kernel/locking/lockdep_proc.c

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