git.oblomov.eu Git - linux-2.6/blob - 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         struct lock_class *class;
  29
  30         (*pos)++;
  31
  32         if (v == SEQ_START_TOKEN)
  33                 class = m->private;
  34         else {
  35                 class = v;
  36
  37                 if (class->lock_entry.next != &all_lock_classes)
  38                         class = list_entry(class->lock_entry.next,
  39                                            struct lock_class, lock_entry);
  40                 else
  41                         class = NULL;
  42         }
  43
  44         return class;
  45 }
  46
  47 static void *l_start(struct seq_file *m, loff_t *pos)
  48 {
  49         struct lock_class *class;
  50         loff_t i = 0;
  51
  52         if (*pos == 0)
  53                 return SEQ_START_TOKEN;
  54
  55         list_for_each_entry(class, &all_lock_classes, lock_entry) {
  56                 if (++i == *pos)
  57                 return class;
  58         }
  59         return NULL;
  60 }
  61
  62 static void l_stop(struct seq_file *m, void *v)
  63 {
  64 }
  65
  66 static unsigned long count_forward_deps(struct lock_class *class)
  67 {
  68         struct lock_list *entry;
  69         unsigned long ret = 1;
  70
  71         /*
  72          * Recurse this class's dependency list:
  73          */
  74         list_for_each_entry(entry, &class->locks_after, entry)
  75                 ret += count_forward_deps(entry->class);
  76
  77         return ret;
  78 }
  79
  80 static unsigned long count_backward_deps(struct lock_class *class)
  81 {
  82         struct lock_list *entry;
  83         unsigned long ret = 1;
  84
  85         /*
  86          * Recurse this class's dependency list:
  87          */
  88         list_for_each_entry(entry, &class->locks_before, entry)
  89                 ret += count_backward_deps(entry->class);
  90
  91         return ret;
  92 }
  93
  94 static void print_name(struct seq_file *m, struct lock_class *class)
  95 {
  96         char str[128];
  97         const char *name = class->name;
  98
  99         if (!name) {
 100                 name = __get_key_name(class->key, str);
 101                 seq_printf(m, "%s", name);
 102         } else{
 103                 seq_printf(m, "%s", name);
 104                 if (class->name_version > 1)
 105                         seq_printf(m, "#%d", class->name_version);
 106                 if (class->subclass)
 107                         seq_printf(m, "/%d", class->subclass);
 108         }
 109 }
 110
 111 static int l_show(struct seq_file *m, void *v)
 112 {
 113         unsigned long nr_forward_deps, nr_backward_deps;
 114         struct lock_class *class = v;
 115         struct lock_list *entry;
 116         char c1, c2, c3, c4;
 117
 118         if (v == SEQ_START_TOKEN) {
 119                 seq_printf(m, "all lock classes:\n");
 120                 return 0;
 121         }
 122
 123         seq_printf(m, "%p", class->key);
 124 #ifdef CONFIG_DEBUG_LOCKDEP
 125         seq_printf(m, " OPS:%8ld", class->ops);
 126 #endif
 127         nr_forward_deps = count_forward_deps(class);
 128         seq_printf(m, " FD:%5ld", nr_forward_deps);
 129
 130         nr_backward_deps = count_backward_deps(class);
 131         seq_printf(m, " BD:%5ld", nr_backward_deps);
 132
 133         get_usage_chars(class, &c1, &c2, &c3, &c4);
 134         seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
 135
 136         seq_printf(m, ": ");
 137         print_name(m, class);
 138         seq_puts(m, "\n");
 139
 140         list_for_each_entry(entry, &class->locks_after, entry) {
 141                 if (entry->distance == 1) {
 142                         seq_printf(m, " -> [%p] ", entry->class);
 143                         print_name(m, entry->class);
 144                         seq_puts(m, "\n");
 145                 }
 146         }
 147         seq_puts(m, "\n");
 148
 149         return 0;
 150 }
 151
 152 static const struct seq_operations lockdep_ops = {
 153         .start  = l_start,
 154         .next   = l_next,
 155         .stop   = l_stop,
 156         .show   = l_show,
 157 };
 158
 159 static int lockdep_open(struct inode *inode, struct file *file)
 160 {
 161         int res = seq_open(file, &lockdep_ops);
 162         if (!res) {
 163                 struct seq_file *m = file->private_data;
 164
 165                 if (!list_empty(&all_lock_classes))
 166                         m->private = list_entry(all_lock_classes.next,
 167                                         struct lock_class, lock_entry);
 168                 else
 169                         m->private = NULL;
 170         }
 171         return res;
 172 }
 173
 174 static const struct file_operations proc_lockdep_operations = {
 175         .open           = lockdep_open,
 176         .read           = seq_read,
 177         .llseek         = seq_lseek,
 178         .release        = seq_release,
 179 };
 180
 181 static void lockdep_stats_debug_show(struct seq_file *m)
 182 {
 183 #ifdef CONFIG_DEBUG_LOCKDEP
 184         unsigned int hi1 = debug_atomic_read(&hardirqs_on_events),
 185                      hi2 = debug_atomic_read(&hardirqs_off_events),
 186                      hr1 = debug_atomic_read(&redundant_hardirqs_on),
 187                      hr2 = debug_atomic_read(&redundant_hardirqs_off),
 188                      si1 = debug_atomic_read(&softirqs_on_events),
 189                      si2 = debug_atomic_read(&softirqs_off_events),
 190                      sr1 = debug_atomic_read(&redundant_softirqs_on),
 191                      sr2 = debug_atomic_read(&redundant_softirqs_off);
 192
 193         seq_printf(m, " chain lookup misses:           %11u\n",
 194                 debug_atomic_read(&chain_lookup_misses));
 195         seq_printf(m, " chain lookup hits:             %11u\n",
 196                 debug_atomic_read(&chain_lookup_hits));
 197         seq_printf(m, " cyclic checks:                 %11u\n",
 198                 debug_atomic_read(&nr_cyclic_checks));
 199         seq_printf(m, " cyclic-check recursions:       %11u\n",
 200                 debug_atomic_read(&nr_cyclic_check_recursions));
 201         seq_printf(m, " find-mask forwards checks:     %11u\n",
 202                 debug_atomic_read(&nr_find_usage_forwards_checks));
 203         seq_printf(m, " find-mask forwards recursions: %11u\n",
 204                 debug_atomic_read(&nr_find_usage_forwards_recursions));
 205         seq_printf(m, " find-mask backwards checks:    %11u\n",
 206                 debug_atomic_read(&nr_find_usage_backwards_checks));
 207         seq_printf(m, " find-mask backwards recursions:%11u\n",
 208                 debug_atomic_read(&nr_find_usage_backwards_recursions));
 209
 210         seq_printf(m, " hardirq on events:             %11u\n", hi1);
 211         seq_printf(m, " hardirq off events:            %11u\n", hi2);
 212         seq_printf(m, " redundant hardirq ons:         %11u\n", hr1);
 213         seq_printf(m, " redundant hardirq offs:        %11u\n", hr2);
 214         seq_printf(m, " softirq on events:             %11u\n", si1);
 215         seq_printf(m, " softirq off events:            %11u\n", si2);
 216         seq_printf(m, " redundant softirq ons:         %11u\n", sr1);
 217         seq_printf(m, " redundant softirq offs:        %11u\n", sr2);
 218 #endif
 219 }
 220
 221 static int lockdep_stats_show(struct seq_file *m, void *v)
 222 {
 223         struct lock_class *class;
 224         unsigned long nr_unused = 0, nr_uncategorized = 0,
 225                       nr_irq_safe = 0, nr_irq_unsafe = 0,
 226                       nr_softirq_safe = 0, nr_softirq_unsafe = 0,
 227                       nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
 228                       nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
 229                       nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
 230                       nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
 231                       sum_forward_deps = 0, factor = 0;
 232
 233         list_for_each_entry(class, &all_lock_classes, lock_entry) {
 234
 235                 if (class->usage_mask == 0)
 236                         nr_unused++;
 237                 if (class->usage_mask == LOCKF_USED)
 238                         nr_uncategorized++;
 239                 if (class->usage_mask & LOCKF_USED_IN_IRQ)
 240                         nr_irq_safe++;
 241                 if (class->usage_mask & LOCKF_ENABLED_IRQS)
 242                         nr_irq_unsafe++;
 243                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
 244                         nr_softirq_safe++;
 245                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
 246                         nr_softirq_unsafe++;
 247                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
 248                         nr_hardirq_safe++;
 249                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
 250                         nr_hardirq_unsafe++;
 251                 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
 252                         nr_irq_read_safe++;
 253                 if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
 254                         nr_irq_read_unsafe++;
 255                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
 256                         nr_softirq_read_safe++;
 257                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
 258                         nr_softirq_read_unsafe++;
 259                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
 260                         nr_hardirq_read_safe++;
 261                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
 262                         nr_hardirq_read_unsafe++;
 263
 264                 sum_forward_deps += count_forward_deps(class);
 265         }
 266 #ifdef CONFIG_DEBUG_LOCKDEP
 267         DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
 268 #endif
 269         seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",
 270                         nr_lock_classes, MAX_LOCKDEP_KEYS);
 271         seq_printf(m, " direct dependencies:           %11lu [max: %lu]\n",
 272                         nr_list_entries, MAX_LOCKDEP_ENTRIES);
 273         seq_printf(m, " indirect dependencies:         %11lu\n",
 274                         sum_forward_deps);
 275
 276         /*
 277          * Total number of dependencies:
 278          *
 279          * All irq-safe locks may nest inside irq-unsafe locks,
 280          * plus all the other known dependencies:
 281          */
 282         seq_printf(m, " all direct dependencies:       %11lu\n",
 283                         nr_irq_unsafe * nr_irq_safe +
 284                         nr_hardirq_unsafe * nr_hardirq_safe +
 285                         nr_list_entries);
 286
 287         /*
 288          * Estimated factor between direct and indirect
 289          * dependencies:
 290          */
 291         if (nr_list_entries)
 292                 factor = sum_forward_deps / nr_list_entries;
 293
 294 #ifdef CONFIG_PROVE_LOCKING
 295         seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
 296                         nr_lock_chains, MAX_LOCKDEP_CHAINS);
 297 #endif
 298
 299 #ifdef CONFIG_TRACE_IRQFLAGS
 300         seq_printf(m, " in-hardirq chains:             %11u\n",
 301                         nr_hardirq_chains);
 302         seq_printf(m, " in-softirq chains:             %11u\n",
 303                         nr_softirq_chains);
 304 #endif
 305         seq_printf(m, " in-process chains:             %11u\n",
 306                         nr_process_chains);
 307         seq_printf(m, " stack-trace entries:           %11lu [max: %lu]\n",
 308                         nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
 309         seq_printf(m, " combined max dependencies:     %11u\n",
 310                         (nr_hardirq_chains + 1) *
 311                         (nr_softirq_chains + 1) *
 312                         (nr_process_chains + 1)
 313         );
 314         seq_printf(m, " hardirq-safe locks:            %11lu\n",
 315                         nr_hardirq_safe);
 316         seq_printf(m, " hardirq-unsafe locks:          %11lu\n",
 317                         nr_hardirq_unsafe);
 318         seq_printf(m, " softirq-safe locks:            %11lu\n",
 319                         nr_softirq_safe);
 320         seq_printf(m, " softirq-unsafe locks:          %11lu\n",
 321                         nr_softirq_unsafe);
 322         seq_printf(m, " irq-safe locks:                %11lu\n",
 323                         nr_irq_safe);
 324         seq_printf(m, " irq-unsafe locks:              %11lu\n",
 325                         nr_irq_unsafe);
 326
 327         seq_printf(m, " hardirq-read-safe locks:       %11lu\n",
 328                         nr_hardirq_read_safe);
 329         seq_printf(m, " hardirq-read-unsafe locks:     %11lu\n",
 330                         nr_hardirq_read_unsafe);
 331         seq_printf(m, " softirq-read-safe locks:       %11lu\n",
 332                         nr_softirq_read_safe);
 333         seq_printf(m, " softirq-read-unsafe locks:     %11lu\n",
 334                         nr_softirq_read_unsafe);
 335         seq_printf(m, " irq-read-safe locks:           %11lu\n",
 336                         nr_irq_read_safe);
 337         seq_printf(m, " irq-read-unsafe locks:         %11lu\n",
 338                         nr_irq_read_unsafe);
 339
 340         seq_printf(m, " uncategorized locks:           %11lu\n",
 341                         nr_uncategorized);
 342         seq_printf(m, " unused locks:                  %11lu\n",
 343                         nr_unused);
 344         seq_printf(m, " max locking depth:             %11u\n",
 345                         max_lockdep_depth);
 346         seq_printf(m, " max recursion depth:           %11u\n",
 347                         max_recursion_depth);
 348         lockdep_stats_debug_show(m);
 349         seq_printf(m, " debug_locks:                   %11u\n",
 350                         debug_locks);
 351
 352         return 0;
 353 }
 354
 355 static int lockdep_stats_open(struct inode *inode, struct file *file)
 356 {
 357         return single_open(file, lockdep_stats_show, NULL);
 358 }
 359
 360 static const struct file_operations proc_lockdep_stats_operations = {
 361         .open           = lockdep_stats_open,
 362         .read           = seq_read,
 363         .llseek         = seq_lseek,
 364         .release        = single_release,
 365 };
 366
 367 #ifdef CONFIG_LOCK_STAT
 368
 369 struct lock_stat_data {
 370         struct lock_class *class;
 371         struct lock_class_stats stats;
 372 };
 373
 374 struct lock_stat_seq {
 375         struct lock_stat_data *iter;
 376         struct lock_stat_data *iter_end;
 377         struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
 378 };
 379
 380 /*
 381  * sort on absolute number of contentions
 382  */
 383 static int lock_stat_cmp(const void *l, const void *r)
 384 {
 385         const struct lock_stat_data *dl = l, *dr = r;
 386         unsigned long nl, nr;
 387
 388         nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
 389         nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
 390
 391         return nr - nl;
 392 }
 393
 394 static void seq_line(struct seq_file *m, char c, int offset, int length)
 395 {
 396         int i;
 397
 398         for (i = 0; i < offset; i++)
 399                 seq_puts(m, " ");
 400         for (i = 0; i < length; i++)
 401                 seq_printf(m, "%c", c);
 402         seq_puts(m, "\n");
 403 }
 404
 405 static void snprint_time(char *buf, size_t bufsiz, s64 nr)
 406 {
 407         unsigned long rem;
 408
 409         rem = do_div(nr, 1000); /* XXX: do_div_signed */
 410         snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, ((int)rem+5)/10);
 411 }
 412
 413 static void seq_time(struct seq_file *m, s64 time)
 414 {
 415         char num[15];
 416
 417         snprint_time(num, sizeof(num), time);
 418         seq_printf(m, " %14s", num);
 419 }
 420
 421 static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
 422 {
 423         seq_printf(m, "%14lu", lt->nr);
 424         seq_time(m, lt->min);
 425         seq_time(m, lt->max);
 426         seq_time(m, lt->total);
 427 }
 428
 429 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
 430 {
 431         char name[39];
 432         struct lock_class *class;
 433         struct lock_class_stats *stats;
 434         int i, namelen;
 435
 436         class = data->class;
 437         stats = &data->stats;
 438
 439         namelen = 38;
 440         if (class->name_version > 1)
 441                 namelen -= 2; /* XXX truncates versions > 9 */
 442         if (class->subclass)
 443                 namelen -= 2;
 444
 445         if (!class->name) {
 446                 char str[KSYM_NAME_LEN];
 447                 const char *key_name;
 448
 449                 key_name = __get_key_name(class->key, str);
 450                 snprintf(name, namelen, "%s", key_name);
 451         } else {
 452                 snprintf(name, namelen, "%s", class->name);
 453         }
 454         namelen = strlen(name);
 455         if (class->name_version > 1) {
 456                 snprintf(name+namelen, 3, "#%d", class->name_version);
 457                 namelen += 2;
 458         }
 459         if (class->subclass) {
 460                 snprintf(name+namelen, 3, "/%d", class->subclass);
 461                 namelen += 2;
 462         }
 463
 464         if (stats->write_holdtime.nr) {
 465                 if (stats->read_holdtime.nr)
 466                         seq_printf(m, "%38s-W:", name);
 467                 else
 468                         seq_printf(m, "%40s:", name);
 469
 470                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
 471                 seq_lock_time(m, &stats->write_waittime);
 472                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
 473                 seq_lock_time(m, &stats->write_holdtime);
 474                 seq_puts(m, "\n");
 475         }
 476
 477         if (stats->read_holdtime.nr) {
 478                 seq_printf(m, "%38s-R:", name);
 479                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
 480                 seq_lock_time(m, &stats->read_waittime);
 481                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
 482                 seq_lock_time(m, &stats->read_holdtime);
 483                 seq_puts(m, "\n");
 484         }
 485
 486         if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
 487                 return;
 488
 489         if (stats->read_holdtime.nr)
 490                 namelen += 2;
 491
 492         for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
 493                 char sym[KSYM_SYMBOL_LEN];
 494                 char ip[32];
 495
 496                 if (class->contention_point[i] == 0)
 497                         break;
 498
 499                 if (!i)
 500                         seq_line(m, '-', 40-namelen, namelen);
 501
 502                 sprint_symbol(sym, class->contention_point[i]);
 503                 snprintf(ip, sizeof(ip), "[<%p>]",
 504                                 (void *)class->contention_point[i]);
 505                 seq_printf(m, "%40s %14lu %29s %s\n", name,
 506                                 stats->contention_point[i],
 507                                 ip, sym);
 508         }
 509         if (i) {
 510                 seq_puts(m, "\n");
 511                 seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
 512                 seq_puts(m, "\n");
 513         }
 514 }
 515
 516 static void seq_header(struct seq_file *m)
 517 {
 518         seq_printf(m, "lock_stat version 0.2\n");
 519         seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
 520         seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
 521                         "%14s %14s\n",
 522                         "class name",
 523                         "con-bounces",
 524                         "contentions",
 525                         "waittime-min",
 526                         "waittime-max",
 527                         "waittime-total",
 528                         "acq-bounces",
 529                         "acquisitions",
 530                         "holdtime-min",
 531                         "holdtime-max",
 532                         "holdtime-total");
 533         seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
 534         seq_printf(m, "\n");
 535 }
 536
 537 static void *ls_start(struct seq_file *m, loff_t *pos)
 538 {
 539         struct lock_stat_seq *data = m->private;
 540
 541         if (*pos == 0)
 542                 return SEQ_START_TOKEN;
 543
 544         data->iter = data->stats + *pos;
 545         if (data->iter >= data->iter_end)
 546                 data->iter = NULL;
 547
 548         return data->iter;
 549 }
 550
 551 static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
 552 {
 553         struct lock_stat_seq *data = m->private;
 554
 555         (*pos)++;
 556
 557         if (v == SEQ_START_TOKEN)
 558                 data->iter = data->stats;
 559         else {
 560                 data->iter = v;
 561                 data->iter++;
 562         }
 563
 564         if (data->iter == data->iter_end)
 565                 data->iter = NULL;
 566
 567         return data->iter;
 568 }
 569
 570 static void ls_stop(struct seq_file *m, void *v)
 571 {
 572 }
 573
 574 static int ls_show(struct seq_file *m, void *v)
 575 {
 576         if (v == SEQ_START_TOKEN)
 577                 seq_header(m);
 578         else
 579                 seq_stats(m, v);
 580
 581         return 0;
 582 }
 583
 584 static struct seq_operations lockstat_ops = {
 585         .start  = ls_start,
 586         .next   = ls_next,
 587         .stop   = ls_stop,
 588         .show   = ls_show,
 589 };
 590
 591 static int lock_stat_open(struct inode *inode, struct file *file)
 592 {
 593         int res;
 594         struct lock_class *class;
 595         struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
 596
 597         if (!data)
 598                 return -ENOMEM;
 599
 600         res = seq_open(file, &lockstat_ops);
 601         if (!res) {
 602                 struct lock_stat_data *iter = data->stats;
 603                 struct seq_file *m = file->private_data;
 604
 605                 data->iter = iter;
 606                 list_for_each_entry(class, &all_lock_classes, lock_entry) {
 607                         iter->class = class;
 608                         iter->stats = lock_stats(class);
 609                         iter++;
 610                 }
 611                 data->iter_end = iter;
 612
 613                 sort(data->stats, data->iter_end - data->iter,
 614                                 sizeof(struct lock_stat_data),
 615                                 lock_stat_cmp, NULL);
 616
 617                 m->private = data;
 618         } else
 619                 vfree(data);
 620
 621         return res;
 622 }
 623
 624 static ssize_t lock_stat_write(struct file *file, const char __user *buf,
 625                                size_t count, loff_t *ppos)
 626 {
 627         struct lock_class *class;
 628         char c;
 629
 630         if (count) {
 631                 if (get_user(c, buf))
 632                         return -EFAULT;
 633
 634                 if (c != '0')
 635                         return count;
 636
 637                 list_for_each_entry(class, &all_lock_classes, lock_entry)
 638                         clear_lock_stats(class);
 639         }
 640         return count;
 641 }
 642
 643 static int lock_stat_release(struct inode *inode, struct file *file)
 644 {
 645         struct seq_file *seq = file->private_data;
 646
 647         vfree(seq->private);
 648         seq->private = NULL;
 649         return seq_release(inode, file);
 650 }
 651
 652 static const struct file_operations proc_lock_stat_operations = {
 653         .open           = lock_stat_open,
 654         .write          = lock_stat_write,
 655         .read           = seq_read,
 656         .llseek         = seq_lseek,
 657         .release        = lock_stat_release,
 658 };
 659 #endif /* CONFIG_LOCK_STAT */
 660
 661 static int __init lockdep_proc_init(void)
 662 {
 663         proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
 664         proc_create("lockdep_stats", S_IRUSR, NULL,
 665                     &proc_lockdep_stats_operations);
 666
 667 #ifdef CONFIG_LOCK_STAT
 668         proc_create("lock_stat", S_IRUSR, NULL, &proc_lock_stat_operations);
 669 #endif
 670
 671         return 0;
 672 }
 673
 674 __initcall(lockdep_proc_init);
 675