lib/debugobjects.c

   1 /*
   2  * Generic infrastructure for lifetime debugging of objects.
   3  *
   4  * Started by Thomas Gleixner
   5  *
   6  * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de>
   7  *
   8  * For licencing details see kernel-base/COPYING
   9  */
  10
  11 #define pr_fmt(fmt) "ODEBUG: " fmt
  12
  13 #include <linux/debugobjects.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/sched.h>
  16 #include <linux/sched/task_stack.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/debugfs.h>
  19 #include <linux/slab.h>
  20 #include <linux/hash.h>
  21 #include <linux/kmemleak.h>
  22
  23 #define ODEBUG_HASH_BITS        14
  24 #define ODEBUG_HASH_SIZE        (1 << ODEBUG_HASH_BITS)
  25
  26 #define ODEBUG_POOL_SIZE        1024
  27 #define ODEBUG_POOL_MIN_LEVEL   256
  28
  29 #define ODEBUG_CHUNK_SHIFT      PAGE_SHIFT
  30 #define ODEBUG_CHUNK_SIZE       (1 << ODEBUG_CHUNK_SHIFT)
  31 #define ODEBUG_CHUNK_MASK       (~(ODEBUG_CHUNK_SIZE - 1))
  32
  33 struct debug_bucket {
  34         struct hlist_head       list;
  35         raw_spinlock_t          lock;
  36 };
  37
  38 static struct debug_bucket      obj_hash[ODEBUG_HASH_SIZE];
  39
  40 static struct debug_obj         obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
  41
  42 static DEFINE_RAW_SPINLOCK(pool_lock);
  43
  44 static HLIST_HEAD(obj_pool);
  45
  46 static int                      obj_pool_min_free = ODEBUG_POOL_SIZE;
  47 static int                      obj_pool_free = ODEBUG_POOL_SIZE;
  48 static int                      obj_pool_used;
  49 static int                      obj_pool_max_used;
  50 static struct kmem_cache        *obj_cache;
  51
  52 static int                      debug_objects_maxchain __read_mostly;
  53 static int                      debug_objects_fixups __read_mostly;
  54 static int                      debug_objects_warnings __read_mostly;
  55 static int                      debug_objects_enabled __read_mostly
  56                                 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
  57 static int                      debug_objects_pool_size __read_mostly
  58                                 = ODEBUG_POOL_SIZE;
  59 static int                      debug_objects_pool_min_level __read_mostly
  60                                 = ODEBUG_POOL_MIN_LEVEL;
  61 static struct debug_obj_descr   *descr_test  __read_mostly;
  62
  63 /*
  64  * Track numbers of kmem_cache_alloc()/free() calls done.
  65  */
  66 static int                      debug_objects_allocated;
  67 static int                      debug_objects_freed;
  68
  69 static void free_obj_work(struct work_struct *work);
  70 static DECLARE_WORK(debug_obj_work, free_obj_work);
  71
  72 static int __init enable_object_debug(char *str)
  73 {
  74         debug_objects_enabled = 1;
  75         return 0;
  76 }
  77
  78 static int __init disable_object_debug(char *str)
  79 {
  80         debug_objects_enabled = 0;
  81         return 0;
  82 }
  83
  84 early_param("debug_objects", enable_object_debug);
  85 early_param("no_debug_objects", disable_object_debug);
  86
  87 static const char *obj_states[ODEBUG_STATE_MAX] = {
  88         [ODEBUG_STATE_NONE]             = "none",
  89         [ODEBUG_STATE_INIT]             = "initialized",
  90         [ODEBUG_STATE_INACTIVE]         = "inactive",
  91         [ODEBUG_STATE_ACTIVE]           = "active",
  92         [ODEBUG_STATE_DESTROYED]        = "destroyed",
  93         [ODEBUG_STATE_NOTAVAILABLE]     = "not available",
  94 };
  95
  96 static void fill_pool(void)
  97 {
  98         gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
  99         struct debug_obj *new;
 100         unsigned long flags;
 101
 102         if (likely(obj_pool_free >= debug_objects_pool_min_level))
 103                 return;
 104
 105         if (unlikely(!obj_cache))
 106                 return;
 107
 108         while (obj_pool_free < debug_objects_pool_min_level) {
 109
 110                 new = kmem_cache_zalloc(obj_cache, gfp);
 111                 if (!new)
 112                         return;
 113
 114                 kmemleak_ignore(new);
 115                 raw_spin_lock_irqsave(&pool_lock, flags);
 116                 hlist_add_head(&new->node, &obj_pool);
 117                 debug_objects_allocated++;
 118                 obj_pool_free++;
 119                 raw_spin_unlock_irqrestore(&pool_lock, flags);
 120         }
 121 }
 122
 123 /*
 124  * Lookup an object in the hash bucket.
 125  */
 126 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
 127 {
 128         struct debug_obj *obj;
 129         int cnt = 0;
 130
 131         hlist_for_each_entry(obj, &b->list, node) {
 132                 cnt++;
 133                 if (obj->object == addr)
 134                         return obj;
 135         }
 136         if (cnt > debug_objects_maxchain)
 137                 debug_objects_maxchain = cnt;
 138
 139         return NULL;
 140 }
 141
 142 /*
 143  * Allocate a new object. If the pool is empty, switch off the debugger.
 144  * Must be called with interrupts disabled.
 145  */
 146 static struct debug_obj *
 147 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
 148 {
 149         struct debug_obj *obj = NULL;
 150
 151         raw_spin_lock(&pool_lock);
 152         if (obj_pool.first) {
 153                 obj         = hlist_entry(obj_pool.first, typeof(*obj), node);
 154
 155                 obj->object = addr;
 156                 obj->descr  = descr;
 157                 obj->state  = ODEBUG_STATE_NONE;
 158                 obj->astate = 0;
 159                 hlist_del(&obj->node);
 160
 161                 hlist_add_head(&obj->node, &b->list);
 162
 163                 obj_pool_used++;
 164                 if (obj_pool_used > obj_pool_max_used)
 165                         obj_pool_max_used = obj_pool_used;
 166
 167                 obj_pool_free--;
 168                 if (obj_pool_free < obj_pool_min_free)
 169                         obj_pool_min_free = obj_pool_free;
 170         }
 171         raw_spin_unlock(&pool_lock);
 172
 173         return obj;
 174 }
 175
 176 /*
 177  * workqueue function to free objects.
 178  *
 179  * To reduce contention on the global pool_lock, the actual freeing of
 180  * debug objects will be delayed if the pool_lock is busy. We also free
 181  * the objects in a batch of 4 for each lock/unlock cycle.
 182  */
 183 #define ODEBUG_FREE_BATCH       4
 184
 185 static void free_obj_work(struct work_struct *work)
 186 {
 187         struct debug_obj *objs[ODEBUG_FREE_BATCH];
 188         unsigned long flags;
 189         int i;
 190
 191         if (!raw_spin_trylock_irqsave(&pool_lock, flags))
 192                 return;
 193         while (obj_pool_free >= debug_objects_pool_size + ODEBUG_FREE_BATCH) {
 194                 for (i = 0; i < ODEBUG_FREE_BATCH; i++) {
 195                         objs[i] = hlist_entry(obj_pool.first,
 196                                               typeof(*objs[0]), node);
 197                         hlist_del(&objs[i]->node);
 198                 }
 199
 200                 obj_pool_free -= ODEBUG_FREE_BATCH;
 201                 debug_objects_freed += ODEBUG_FREE_BATCH;
 202                 /*
 203                  * We release pool_lock across kmem_cache_free() to
 204                  * avoid contention on pool_lock.
 205                  */
 206                 raw_spin_unlock_irqrestore(&pool_lock, flags);
 207                 for (i = 0; i < ODEBUG_FREE_BATCH; i++)
 208                         kmem_cache_free(obj_cache, objs[i]);
 209                 if (!raw_spin_trylock_irqsave(&pool_lock, flags))
 210                         return;
 211         }
 212         raw_spin_unlock_irqrestore(&pool_lock, flags);
 213 }
 214
 215 /*
 216  * Put the object back into the pool and schedule work to free objects
 217  * if necessary.
 218  */
 219 static void free_object(struct debug_obj *obj)
 220 {
 221         unsigned long flags;
 222         int sched = 0;
 223
 224         raw_spin_lock_irqsave(&pool_lock, flags);
 225         /*
 226          * schedule work when the pool is filled and the cache is
 227          * initialized:
 228          */
 229         if (obj_pool_free > debug_objects_pool_size && obj_cache)
 230                 sched = 1;
 231         hlist_add_head(&obj->node, &obj_pool);
 232         obj_pool_free++;
 233         obj_pool_used--;
 234         raw_spin_unlock_irqrestore(&pool_lock, flags);
 235         if (sched)
 236                 schedule_work(&debug_obj_work);
 237 }
 238
 239 /*
 240  * We run out of memory. That means we probably have tons of objects
 241  * allocated.
 242  */
 243 static void debug_objects_oom(void)
 244 {
 245         struct debug_bucket *db = obj_hash;
 246         struct hlist_node *tmp;
 247         HLIST_HEAD(freelist);
 248         struct debug_obj *obj;
 249         unsigned long flags;
 250         int i;
 251
 252         pr_warn("Out of memory. ODEBUG disabled\n");
 253
 254         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
 255                 raw_spin_lock_irqsave(&db->lock, flags);
 256                 hlist_move_list(&db->list, &freelist);
 257                 raw_spin_unlock_irqrestore(&db->lock, flags);
 258
 259                 /* Now free them */
 260                 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
 261                         hlist_del(&obj->node);
 262                         free_object(obj);
 263                 }
 264         }
 265 }
 266
 267 /*
 268  * We use the pfn of the address for the hash. That way we can check
 269  * for freed objects simply by checking the affected bucket.
 270  */
 271 static struct debug_bucket *get_bucket(unsigned long addr)
 272 {
 273         unsigned long hash;
 274
 275         hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
 276         return &obj_hash[hash];
 277 }
 278
 279 static void debug_print_object(struct debug_obj *obj, char *msg)
 280 {
 281         struct debug_obj_descr *descr = obj->descr;
 282         static int limit;
 283
 284         if (limit < 5 && descr != descr_test) {
 285                 void *hint = descr->debug_hint ?
 286                         descr->debug_hint(obj->object) : NULL;
 287                 limit++;
 288                 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
 289                                  "object type: %s hint: %pS\n",
 290                         msg, obj_states[obj->state], obj->astate,
 291                         descr->name, hint);
 292         }
 293         debug_objects_warnings++;
 294 }
 295
 296 /*
 297  * Try to repair the damage, so we have a better chance to get useful
 298  * debug output.
 299  */
 300 static bool
 301 debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
 302                    void * addr, enum debug_obj_state state)
 303 {
 304         if (fixup && fixup(addr, state)) {
 305                 debug_objects_fixups++;
 306                 return true;
 307         }
 308         return false;
 309 }
 310
 311 static void debug_object_is_on_stack(void *addr, int onstack)
 312 {
 313         int is_on_stack;
 314         static int limit;
 315
 316         if (limit > 4)
 317                 return;
 318
 319         is_on_stack = object_is_on_stack(addr);
 320         if (is_on_stack == onstack)
 321                 return;
 322
 323         limit++;
 324         if (is_on_stack)
 325                 pr_warn("object %p is on stack %p, but NOT annotated.\n", addr,
 326                          task_stack_page(current));
 327         else
 328                 pr_warn("object %p is NOT on stack %p, but annotated.\n", addr,
 329                          task_stack_page(current));
 330
 331         WARN_ON(1);
 332 }
 333
 334 static void
 335 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
 336 {
 337         enum debug_obj_state state;
 338         struct debug_bucket *db;
 339         struct debug_obj *obj;
 340         unsigned long flags;
 341
 342         fill_pool();
 343
 344         db = get_bucket((unsigned long) addr);
 345
 346         raw_spin_lock_irqsave(&db->lock, flags);
 347
 348         obj = lookup_object(addr, db);
 349         if (!obj) {
 350                 obj = alloc_object(addr, db, descr);
 351                 if (!obj) {
 352                         debug_objects_enabled = 0;
 353                         raw_spin_unlock_irqrestore(&db->lock, flags);
 354                         debug_objects_oom();
 355                         return;
 356                 }
 357                 debug_object_is_on_stack(addr, onstack);
 358         }
 359
 360         switch (obj->state) {
 361         case ODEBUG_STATE_NONE:
 362         case ODEBUG_STATE_INIT:
 363         case ODEBUG_STATE_INACTIVE:
 364                 obj->state = ODEBUG_STATE_INIT;
 365                 break;
 366
 367         case ODEBUG_STATE_ACTIVE:
 368                 debug_print_object(obj, "init");
 369                 state = obj->state;
 370                 raw_spin_unlock_irqrestore(&db->lock, flags);
 371                 debug_object_fixup(descr->fixup_init, addr, state);
 372                 return;
 373
 374         case ODEBUG_STATE_DESTROYED:
 375                 debug_print_object(obj, "init");
 376                 break;
 377         default:
 378                 break;
 379         }
 380
 381         raw_spin_unlock_irqrestore(&db->lock, flags);
 382 }
 383
 384 /**
 385  * debug_object_init - debug checks when an object is initialized
 386  * @addr:       address of the object
 387  * @descr:      pointer to an object specific debug description structure
 388  */
 389 void debug_object_init(void *addr, struct debug_obj_descr *descr)
 390 {
 391         if (!debug_objects_enabled)
 392                 return;
 393
 394         __debug_object_init(addr, descr, 0);
 395 }
 396 EXPORT_SYMBOL_GPL(debug_object_init);
 397
 398 /**
 399  * debug_object_init_on_stack - debug checks when an object on stack is
 400  *                              initialized
 401  * @addr:       address of the object
 402  * @descr:      pointer to an object specific debug description structure
 403  */
 404 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
 405 {
 406         if (!debug_objects_enabled)
 407                 return;
 408
 409         __debug_object_init(addr, descr, 1);
 410 }
 411 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
 412
 413 /**
 414  * debug_object_activate - debug checks when an object is activated
 415  * @addr:       address of the object
 416  * @descr:      pointer to an object specific debug description structure
 417  * Returns 0 for success, -EINVAL for check failed.
 418  */
 419 int debug_object_activate(void *addr, struct debug_obj_descr *descr)
 420 {
 421         enum debug_obj_state state;
 422         struct debug_bucket *db;
 423         struct debug_obj *obj;
 424         unsigned long flags;
 425         int ret;
 426         struct debug_obj o = { .object = addr,
 427                                .state = ODEBUG_STATE_NOTAVAILABLE,
 428                                .descr = descr };
 429
 430         if (!debug_objects_enabled)
 431                 return 0;
 432
 433         db = get_bucket((unsigned long) addr);
 434
 435         raw_spin_lock_irqsave(&db->lock, flags);
 436
 437         obj = lookup_object(addr, db);
 438         if (obj) {
 439                 switch (obj->state) {
 440                 case ODEBUG_STATE_INIT:
 441                 case ODEBUG_STATE_INACTIVE:
 442                         obj->state = ODEBUG_STATE_ACTIVE;
 443                         ret = 0;
 444                         break;
 445
 446                 case ODEBUG_STATE_ACTIVE:
 447                         debug_print_object(obj, "activate");
 448                         state = obj->state;
 449                         raw_spin_unlock_irqrestore(&db->lock, flags);
 450                         ret = debug_object_fixup(descr->fixup_activate, addr, state);
 451                         return ret ? 0 : -EINVAL;
 452
 453                 case ODEBUG_STATE_DESTROYED:
 454                         debug_print_object(obj, "activate");
 455                         ret = -EINVAL;
 456                         break;
 457                 default:
 458                         ret = 0;
 459                         break;
 460                 }
 461                 raw_spin_unlock_irqrestore(&db->lock, flags);
 462                 return ret;
 463         }
 464
 465         raw_spin_unlock_irqrestore(&db->lock, flags);
 466         /*
 467          * We are here when a static object is activated. We
 468          * let the type specific code confirm whether this is
 469          * true or not. if true, we just make sure that the
 470          * static object is tracked in the object tracker. If
 471          * not, this must be a bug, so we try to fix it up.
 472          */
 473         if (descr->is_static_object && descr->is_static_object(addr)) {
 474                 /* track this static object */
 475                 debug_object_init(addr, descr);
 476                 debug_object_activate(addr, descr);
 477         } else {
 478                 debug_print_object(&o, "activate");
 479                 ret = debug_object_fixup(descr->fixup_activate, addr,
 480                                         ODEBUG_STATE_NOTAVAILABLE);
 481                 return ret ? 0 : -EINVAL;
 482         }
 483         return 0;
 484 }
 485 EXPORT_SYMBOL_GPL(debug_object_activate);
 486
 487 /**
 488  * debug_object_deactivate - debug checks when an object is deactivated
 489  * @addr:       address of the object
 490  * @descr:      pointer to an object specific debug description structure
 491  */
 492 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
 493 {
 494         struct debug_bucket *db;
 495         struct debug_obj *obj;
 496         unsigned long flags;
 497
 498         if (!debug_objects_enabled)
 499                 return;
 500
 501         db = get_bucket((unsigned long) addr);
 502
 503         raw_spin_lock_irqsave(&db->lock, flags);
 504
 505         obj = lookup_object(addr, db);
 506         if (obj) {
 507                 switch (obj->state) {
 508                 case ODEBUG_STATE_INIT:
 509                 case ODEBUG_STATE_INACTIVE:
 510                 case ODEBUG_STATE_ACTIVE:
 511                         if (!obj->astate)
 512                                 obj->state = ODEBUG_STATE_INACTIVE;
 513                         else
 514                                 debug_print_object(obj, "deactivate");
 515                         break;
 516
 517                 case ODEBUG_STATE_DESTROYED:
 518                         debug_print_object(obj, "deactivate");
 519                         break;
 520                 default:
 521                         break;
 522                 }
 523         } else {
 524                 struct debug_obj o = { .object = addr,
 525                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 526                                        .descr = descr };
 527
 528                 debug_print_object(&o, "deactivate");
 529         }
 530
 531         raw_spin_unlock_irqrestore(&db->lock, flags);
 532 }
 533 EXPORT_SYMBOL_GPL(debug_object_deactivate);
 534
 535 /**
 536  * debug_object_destroy - debug checks when an object is destroyed
 537  * @addr:       address of the object
 538  * @descr:      pointer to an object specific debug description structure
 539  */
 540 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
 541 {
 542         enum debug_obj_state state;
 543         struct debug_bucket *db;
 544         struct debug_obj *obj;
 545         unsigned long flags;
 546
 547         if (!debug_objects_enabled)
 548                 return;
 549
 550         db = get_bucket((unsigned long) addr);
 551
 552         raw_spin_lock_irqsave(&db->lock, flags);
 553
 554         obj = lookup_object(addr, db);
 555         if (!obj)
 556                 goto out_unlock;
 557
 558         switch (obj->state) {
 559         case ODEBUG_STATE_NONE:
 560         case ODEBUG_STATE_INIT:
 561         case ODEBUG_STATE_INACTIVE:
 562                 obj->state = ODEBUG_STATE_DESTROYED;
 563                 break;
 564         case ODEBUG_STATE_ACTIVE:
 565                 debug_print_object(obj, "destroy");
 566                 state = obj->state;
 567                 raw_spin_unlock_irqrestore(&db->lock, flags);
 568                 debug_object_fixup(descr->fixup_destroy, addr, state);
 569                 return;
 570
 571         case ODEBUG_STATE_DESTROYED:
 572                 debug_print_object(obj, "destroy");
 573                 break;
 574         default:
 575                 break;
 576         }
 577 out_unlock:
 578         raw_spin_unlock_irqrestore(&db->lock, flags);
 579 }
 580 EXPORT_SYMBOL_GPL(debug_object_destroy);
 581
 582 /**
 583  * debug_object_free - debug checks when an object is freed
 584  * @addr:       address of the object
 585  * @descr:      pointer to an object specific debug description structure
 586  */
 587 void debug_object_free(void *addr, struct debug_obj_descr *descr)
 588 {
 589         enum debug_obj_state state;
 590         struct debug_bucket *db;
 591         struct debug_obj *obj;
 592         unsigned long flags;
 593
 594         if (!debug_objects_enabled)
 595                 return;
 596
 597         db = get_bucket((unsigned long) addr);
 598
 599         raw_spin_lock_irqsave(&db->lock, flags);
 600
 601         obj = lookup_object(addr, db);
 602         if (!obj)
 603                 goto out_unlock;
 604
 605         switch (obj->state) {
 606         case ODEBUG_STATE_ACTIVE:
 607                 debug_print_object(obj, "free");
 608                 state = obj->state;
 609                 raw_spin_unlock_irqrestore(&db->lock, flags);
 610                 debug_object_fixup(descr->fixup_free, addr, state);
 611                 return;
 612         default:
 613                 hlist_del(&obj->node);
 614                 raw_spin_unlock_irqrestore(&db->lock, flags);
 615                 free_object(obj);
 616                 return;
 617         }
 618 out_unlock:
 619         raw_spin_unlock_irqrestore(&db->lock, flags);
 620 }
 621 EXPORT_SYMBOL_GPL(debug_object_free);
 622
 623 /**
 624  * debug_object_assert_init - debug checks when object should be init-ed
 625  * @addr:       address of the object
 626  * @descr:      pointer to an object specific debug description structure
 627  */
 628 void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
 629 {
 630         struct debug_bucket *db;
 631         struct debug_obj *obj;
 632         unsigned long flags;
 633
 634         if (!debug_objects_enabled)
 635                 return;
 636
 637         db = get_bucket((unsigned long) addr);
 638
 639         raw_spin_lock_irqsave(&db->lock, flags);
 640
 641         obj = lookup_object(addr, db);
 642         if (!obj) {
 643                 struct debug_obj o = { .object = addr,
 644                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 645                                        .descr = descr };
 646
 647                 raw_spin_unlock_irqrestore(&db->lock, flags);
 648                 /*
 649                  * Maybe the object is static, and we let the type specific
 650                  * code confirm. Track this static object if true, else invoke
 651                  * fixup.
 652                  */
 653                 if (descr->is_static_object && descr->is_static_object(addr)) {
 654                         /* Track this static object */
 655                         debug_object_init(addr, descr);
 656                 } else {
 657                         debug_print_object(&o, "assert_init");
 658                         debug_object_fixup(descr->fixup_assert_init, addr,
 659                                            ODEBUG_STATE_NOTAVAILABLE);
 660                 }
 661                 return;
 662         }
 663
 664         raw_spin_unlock_irqrestore(&db->lock, flags);
 665 }
 666 EXPORT_SYMBOL_GPL(debug_object_assert_init);
 667
 668 /**
 669  * debug_object_active_state - debug checks object usage state machine
 670  * @addr:       address of the object
 671  * @descr:      pointer to an object specific debug description structure
 672  * @expect:     expected state
 673  * @next:       state to move to if expected state is found
 674  */
 675 void
 676 debug_object_active_state(void *addr, struct debug_obj_descr *descr,
 677                           unsigned int expect, unsigned int next)
 678 {
 679         struct debug_bucket *db;
 680         struct debug_obj *obj;
 681         unsigned long flags;
 682
 683         if (!debug_objects_enabled)
 684                 return;
 685
 686         db = get_bucket((unsigned long) addr);
 687
 688         raw_spin_lock_irqsave(&db->lock, flags);
 689
 690         obj = lookup_object(addr, db);
 691         if (obj) {
 692                 switch (obj->state) {
 693                 case ODEBUG_STATE_ACTIVE:
 694                         if (obj->astate == expect)
 695                                 obj->astate = next;
 696                         else
 697                                 debug_print_object(obj, "active_state");
 698                         break;
 699
 700                 default:
 701                         debug_print_object(obj, "active_state");
 702                         break;
 703                 }
 704         } else {
 705                 struct debug_obj o = { .object = addr,
 706                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 707                                        .descr = descr };
 708
 709                 debug_print_object(&o, "active_state");
 710         }
 711
 712         raw_spin_unlock_irqrestore(&db->lock, flags);
 713 }
 714 EXPORT_SYMBOL_GPL(debug_object_active_state);
 715
 716 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 717 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
 718 {
 719         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
 720         struct hlist_node *tmp;
 721         HLIST_HEAD(freelist);
 722         struct debug_obj_descr *descr;
 723         enum debug_obj_state state;
 724         struct debug_bucket *db;
 725         struct debug_obj *obj;
 726         int cnt;
 727
 728         saddr = (unsigned long) address;
 729         eaddr = saddr + size;
 730         paddr = saddr & ODEBUG_CHUNK_MASK;
 731         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
 732         chunks >>= ODEBUG_CHUNK_SHIFT;
 733
 734         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
 735                 db = get_bucket(paddr);
 736
 737 repeat:
 738                 cnt = 0;
 739                 raw_spin_lock_irqsave(&db->lock, flags);
 740                 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
 741                         cnt++;
 742                         oaddr = (unsigned long) obj->object;
 743                         if (oaddr < saddr || oaddr >= eaddr)
 744                                 continue;
 745
 746                         switch (obj->state) {
 747                         case ODEBUG_STATE_ACTIVE:
 748                                 debug_print_object(obj, "free");
 749                                 descr = obj->descr;
 750                                 state = obj->state;
 751                                 raw_spin_unlock_irqrestore(&db->lock, flags);
 752                                 debug_object_fixup(descr->fixup_free,
 753                                                    (void *) oaddr, state);
 754                                 goto repeat;
 755                         default:
 756                                 hlist_del(&obj->node);
 757                                 hlist_add_head(&obj->node, &freelist);
 758                                 break;
 759                         }
 760                 }
 761                 raw_spin_unlock_irqrestore(&db->lock, flags);
 762
 763                 /* Now free them */
 764                 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
 765                         hlist_del(&obj->node);
 766                         free_object(obj);
 767                 }
 768
 769                 if (cnt > debug_objects_maxchain)
 770                         debug_objects_maxchain = cnt;
 771         }
 772 }
 773
 774 void debug_check_no_obj_freed(const void *address, unsigned long size)
 775 {
 776         if (debug_objects_enabled)
 777                 __debug_check_no_obj_freed(address, size);
 778 }
 779 #endif
 780
 781 #ifdef CONFIG_DEBUG_FS
 782
 783 static int debug_stats_show(struct seq_file *m, void *v)
 784 {
 785         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
 786         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
 787         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
 788         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
 789         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
 790         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
 791         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
 792         seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
 793         seq_printf(m, "objs_freed    :%d\n", debug_objects_freed);
 794         return 0;
 795 }
 796
 797 static int debug_stats_open(struct inode *inode, struct file *filp)
 798 {
 799         return single_open(filp, debug_stats_show, NULL);
 800 }
 801
 802 static const struct file_operations debug_stats_fops = {
 803         .open           = debug_stats_open,
 804         .read           = seq_read,
 805         .llseek         = seq_lseek,
 806         .release        = single_release,
 807 };
 808
 809 static int __init debug_objects_init_debugfs(void)
 810 {
 811         struct dentry *dbgdir, *dbgstats;
 812
 813         if (!debug_objects_enabled)
 814                 return 0;
 815
 816         dbgdir = debugfs_create_dir("debug_objects", NULL);
 817         if (!dbgdir)
 818                 return -ENOMEM;
 819
 820         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
 821                                        &debug_stats_fops);
 822         if (!dbgstats)
 823                 goto err;
 824
 825         return 0;
 826
 827 err:
 828         debugfs_remove(dbgdir);
 829
 830         return -ENOMEM;
 831 }
 832 __initcall(debug_objects_init_debugfs);
 833
 834 #else
 835 static inline void debug_objects_init_debugfs(void) { }
 836 #endif
 837
 838 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
 839
 840 /* Random data structure for the self test */
 841 struct self_test {
 842         unsigned long   dummy1[6];
 843         int             static_init;
 844         unsigned long   dummy2[3];
 845 };
 846
 847 static __initdata struct debug_obj_descr descr_type_test;
 848
 849 static bool __init is_static_object(void *addr)
 850 {
 851         struct self_test *obj = addr;
 852
 853         return obj->static_init;
 854 }
 855
 856 /*
 857  * fixup_init is called when:
 858  * - an active object is initialized
 859  */
 860 static bool __init fixup_init(void *addr, enum debug_obj_state state)
 861 {
 862         struct self_test *obj = addr;
 863
 864         switch (state) {
 865         case ODEBUG_STATE_ACTIVE:
 866                 debug_object_deactivate(obj, &descr_type_test);
 867                 debug_object_init(obj, &descr_type_test);
 868                 return true;
 869         default:
 870                 return false;
 871         }
 872 }
 873
 874 /*
 875  * fixup_activate is called when:
 876  * - an active object is activated
 877  * - an unknown non-static object is activated
 878  */
 879 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
 880 {
 881         struct self_test *obj = addr;
 882
 883         switch (state) {
 884         case ODEBUG_STATE_NOTAVAILABLE:
 885                 return true;
 886         case ODEBUG_STATE_ACTIVE:
 887                 debug_object_deactivate(obj, &descr_type_test);
 888                 debug_object_activate(obj, &descr_type_test);
 889                 return true;
 890
 891         default:
 892                 return false;
 893         }
 894 }
 895
 896 /*
 897  * fixup_destroy is called when:
 898  * - an active object is destroyed
 899  */
 900 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
 901 {
 902         struct self_test *obj = addr;
 903
 904         switch (state) {
 905         case ODEBUG_STATE_ACTIVE:
 906                 debug_object_deactivate(obj, &descr_type_test);
 907                 debug_object_destroy(obj, &descr_type_test);
 908                 return true;
 909         default:
 910                 return false;
 911         }
 912 }
 913
 914 /*
 915  * fixup_free is called when:
 916  * - an active object is freed
 917  */
 918 static bool __init fixup_free(void *addr, enum debug_obj_state state)
 919 {
 920         struct self_test *obj = addr;
 921
 922         switch (state) {
 923         case ODEBUG_STATE_ACTIVE:
 924                 debug_object_deactivate(obj, &descr_type_test);
 925                 debug_object_free(obj, &descr_type_test);
 926                 return true;
 927         default:
 928                 return false;
 929         }
 930 }
 931
 932 static int __init
 933 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
 934 {
 935         struct debug_bucket *db;
 936         struct debug_obj *obj;
 937         unsigned long flags;
 938         int res = -EINVAL;
 939
 940         db = get_bucket((unsigned long) addr);
 941
 942         raw_spin_lock_irqsave(&db->lock, flags);
 943
 944         obj = lookup_object(addr, db);
 945         if (!obj && state != ODEBUG_STATE_NONE) {
 946                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
 947                 goto out;
 948         }
 949         if (obj && obj->state != state) {
 950                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
 951                        obj->state, state);
 952                 goto out;
 953         }
 954         if (fixups != debug_objects_fixups) {
 955                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
 956                        fixups, debug_objects_fixups);
 957                 goto out;
 958         }
 959         if (warnings != debug_objects_warnings) {
 960                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
 961                        warnings, debug_objects_warnings);
 962                 goto out;
 963         }
 964         res = 0;
 965 out:
 966         raw_spin_unlock_irqrestore(&db->lock, flags);
 967         if (res)
 968                 debug_objects_enabled = 0;
 969         return res;
 970 }
 971
 972 static __initdata struct debug_obj_descr descr_type_test = {
 973         .name                   = "selftest",
 974         .is_static_object       = is_static_object,
 975         .fixup_init             = fixup_init,
 976         .fixup_activate         = fixup_activate,
 977         .fixup_destroy          = fixup_destroy,
 978         .fixup_free             = fixup_free,
 979 };
 980
 981 static __initdata struct self_test obj = { .static_init = 0 };
 982
 983 static void __init debug_objects_selftest(void)
 984 {
 985         int fixups, oldfixups, warnings, oldwarnings;
 986         unsigned long flags;
 987
 988         local_irq_save(flags);
 989
 990         fixups = oldfixups = debug_objects_fixups;
 991         warnings = oldwarnings = debug_objects_warnings;
 992         descr_test = &descr_type_test;
 993
 994         debug_object_init(&obj, &descr_type_test);
 995         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
 996                 goto out;
 997         debug_object_activate(&obj, &descr_type_test);
 998         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
 999                 goto out;
1000         debug_object_activate(&obj, &descr_type_test);
1001         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
1002                 goto out;
1003         debug_object_deactivate(&obj, &descr_type_test);
1004         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1005                 goto out;
1006         debug_object_destroy(&obj, &descr_type_test);
1007         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1008                 goto out;
1009         debug_object_init(&obj, &descr_type_test);
1010         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1011                 goto out;
1012         debug_object_activate(&obj, &descr_type_test);
1013         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1014                 goto out;
1015         debug_object_deactivate(&obj, &descr_type_test);
1016         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1017                 goto out;
1018         debug_object_free(&obj, &descr_type_test);
1019         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1020                 goto out;
1021
1022         obj.static_init = 1;
1023         debug_object_activate(&obj, &descr_type_test);
1024         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1025                 goto out;
1026         debug_object_init(&obj, &descr_type_test);
1027         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1028                 goto out;
1029         debug_object_free(&obj, &descr_type_test);
1030         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1031                 goto out;
1032
1033 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1034         debug_object_init(&obj, &descr_type_test);
1035         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1036                 goto out;
1037         debug_object_activate(&obj, &descr_type_test);
1038         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1039                 goto out;
1040         __debug_check_no_obj_freed(&obj, sizeof(obj));
1041         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1042                 goto out;
1043 #endif
1044         pr_info("selftest passed\n");
1045
1046 out:
1047         debug_objects_fixups = oldfixups;
1048         debug_objects_warnings = oldwarnings;
1049         descr_test = NULL;
1050
1051         local_irq_restore(flags);
1052 }
1053 #else
1054 static inline void debug_objects_selftest(void) { }
1055 #endif
1056
1057 /*
1058  * Called during early boot to initialize the hash buckets and link
1059  * the static object pool objects into the poll list. After this call
1060  * the object tracker is fully operational.
1061  */
1062 void __init debug_objects_early_init(void)
1063 {
1064         int i;
1065
1066         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1067                 raw_spin_lock_init(&obj_hash[i].lock);
1068
1069         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1070                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1071 }
1072
1073 /*
1074  * Convert the statically allocated objects to dynamic ones:
1075  */
1076 static int __init debug_objects_replace_static_objects(void)
1077 {
1078         struct debug_bucket *db = obj_hash;
1079         struct hlist_node *tmp;
1080         struct debug_obj *obj, *new;
1081         HLIST_HEAD(objects);
1082         int i, cnt = 0;
1083
1084         for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1085                 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1086                 if (!obj)
1087                         goto free;
1088                 kmemleak_ignore(obj);
1089                 hlist_add_head(&obj->node, &objects);
1090         }
1091
1092         /*
1093          * When debug_objects_mem_init() is called we know that only
1094          * one CPU is up, so disabling interrupts is enough
1095          * protection. This avoids the lockdep hell of lock ordering.
1096          */
1097         local_irq_disable();
1098
1099         /* Remove the statically allocated objects from the pool */
1100         hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1101                 hlist_del(&obj->node);
1102         /* Move the allocated objects to the pool */
1103         hlist_move_list(&objects, &obj_pool);
1104
1105         /* Replace the active object references */
1106         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1107                 hlist_move_list(&db->list, &objects);
1108
1109                 hlist_for_each_entry(obj, &objects, node) {
1110                         new = hlist_entry(obj_pool.first, typeof(*obj), node);
1111                         hlist_del(&new->node);
1112                         /* copy object data */
1113                         *new = *obj;
1114                         hlist_add_head(&new->node, &db->list);
1115                         cnt++;
1116                 }
1117         }
1118         local_irq_enable();
1119
1120         pr_debug("%d of %d active objects replaced\n",
1121                  cnt, obj_pool_used);
1122         return 0;
1123 free:
1124         hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1125                 hlist_del(&obj->node);
1126                 kmem_cache_free(obj_cache, obj);
1127         }
1128         return -ENOMEM;
1129 }
1130
1131 /*
1132  * Called after the kmem_caches are functional to setup a dedicated
1133  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1134  * prevents that the debug code is called on kmem_cache_free() for the
1135  * debug tracker objects to avoid recursive calls.
1136  */
1137 void __init debug_objects_mem_init(void)
1138 {
1139         if (!debug_objects_enabled)
1140                 return;
1141
1142         obj_cache = kmem_cache_create("debug_objects_cache",
1143                                       sizeof (struct debug_obj), 0,
1144                                       SLAB_DEBUG_OBJECTS, NULL);
1145
1146         if (!obj_cache || debug_objects_replace_static_objects()) {
1147                 debug_objects_enabled = 0;
1148                 if (obj_cache)
1149                         kmem_cache_destroy(obj_cache);
1150                 pr_warn("out of memory.\n");
1151         } else
1152                 debug_objects_selftest();
1153
1154         /*
1155          * Increase the thresholds for allocating and freeing objects
1156          * according to the number of possible CPUs available in the system.
1157          */
1158         debug_objects_pool_size += num_possible_cpus() * 32;
1159         debug_objects_pool_min_level += num_possible_cpus() * 4;
1160 }