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 is on stack, but not annotated\n");
 326         else
 327                 pr_warn("object is not on stack, but annotated\n");
 328         WARN_ON(1);
 329 }
 330
 331 static void
 332 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
 333 {
 334         enum debug_obj_state state;
 335         struct debug_bucket *db;
 336         struct debug_obj *obj;
 337         unsigned long flags;
 338
 339         fill_pool();
 340
 341         db = get_bucket((unsigned long) addr);
 342
 343         raw_spin_lock_irqsave(&db->lock, flags);
 344
 345         obj = lookup_object(addr, db);
 346         if (!obj) {
 347                 obj = alloc_object(addr, db, descr);
 348                 if (!obj) {
 349                         debug_objects_enabled = 0;
 350                         raw_spin_unlock_irqrestore(&db->lock, flags);
 351                         debug_objects_oom();
 352                         return;
 353                 }
 354                 debug_object_is_on_stack(addr, onstack);
 355         }
 356
 357         switch (obj->state) {
 358         case ODEBUG_STATE_NONE:
 359         case ODEBUG_STATE_INIT:
 360         case ODEBUG_STATE_INACTIVE:
 361                 obj->state = ODEBUG_STATE_INIT;
 362                 break;
 363
 364         case ODEBUG_STATE_ACTIVE:
 365                 debug_print_object(obj, "init");
 366                 state = obj->state;
 367                 raw_spin_unlock_irqrestore(&db->lock, flags);
 368                 debug_object_fixup(descr->fixup_init, addr, state);
 369                 return;
 370
 371         case ODEBUG_STATE_DESTROYED:
 372                 debug_print_object(obj, "init");
 373                 break;
 374         default:
 375                 break;
 376         }
 377
 378         raw_spin_unlock_irqrestore(&db->lock, flags);
 379 }
 380
 381 /**
 382  * debug_object_init - debug checks when an object is initialized
 383  * @addr:       address of the object
 384  * @descr:      pointer to an object specific debug description structure
 385  */
 386 void debug_object_init(void *addr, struct debug_obj_descr *descr)
 387 {
 388         if (!debug_objects_enabled)
 389                 return;
 390
 391         __debug_object_init(addr, descr, 0);
 392 }
 393 EXPORT_SYMBOL_GPL(debug_object_init);
 394
 395 /**
 396  * debug_object_init_on_stack - debug checks when an object on stack is
 397  *                              initialized
 398  * @addr:       address of the object
 399  * @descr:      pointer to an object specific debug description structure
 400  */
 401 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
 402 {
 403         if (!debug_objects_enabled)
 404                 return;
 405
 406         __debug_object_init(addr, descr, 1);
 407 }
 408 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
 409
 410 /**
 411  * debug_object_activate - debug checks when an object is activated
 412  * @addr:       address of the object
 413  * @descr:      pointer to an object specific debug description structure
 414  * Returns 0 for success, -EINVAL for check failed.
 415  */
 416 int debug_object_activate(void *addr, struct debug_obj_descr *descr)
 417 {
 418         enum debug_obj_state state;
 419         struct debug_bucket *db;
 420         struct debug_obj *obj;
 421         unsigned long flags;
 422         int ret;
 423         struct debug_obj o = { .object = addr,
 424                                .state = ODEBUG_STATE_NOTAVAILABLE,
 425                                .descr = descr };
 426
 427         if (!debug_objects_enabled)
 428                 return 0;
 429
 430         db = get_bucket((unsigned long) addr);
 431
 432         raw_spin_lock_irqsave(&db->lock, flags);
 433
 434         obj = lookup_object(addr, db);
 435         if (obj) {
 436                 switch (obj->state) {
 437                 case ODEBUG_STATE_INIT:
 438                 case ODEBUG_STATE_INACTIVE:
 439                         obj->state = ODEBUG_STATE_ACTIVE;
 440                         ret = 0;
 441                         break;
 442
 443                 case ODEBUG_STATE_ACTIVE:
 444                         debug_print_object(obj, "activate");
 445                         state = obj->state;
 446                         raw_spin_unlock_irqrestore(&db->lock, flags);
 447                         ret = debug_object_fixup(descr->fixup_activate, addr, state);
 448                         return ret ? 0 : -EINVAL;
 449
 450                 case ODEBUG_STATE_DESTROYED:
 451                         debug_print_object(obj, "activate");
 452                         ret = -EINVAL;
 453                         break;
 454                 default:
 455                         ret = 0;
 456                         break;
 457                 }
 458                 raw_spin_unlock_irqrestore(&db->lock, flags);
 459                 return ret;
 460         }
 461
 462         raw_spin_unlock_irqrestore(&db->lock, flags);
 463         /*
 464          * We are here when a static object is activated. We
 465          * let the type specific code confirm whether this is
 466          * true or not. if true, we just make sure that the
 467          * static object is tracked in the object tracker. If
 468          * not, this must be a bug, so we try to fix it up.
 469          */
 470         if (descr->is_static_object && descr->is_static_object(addr)) {
 471                 /* track this static object */
 472                 debug_object_init(addr, descr);
 473                 debug_object_activate(addr, descr);
 474         } else {
 475                 debug_print_object(&o, "activate");
 476                 ret = debug_object_fixup(descr->fixup_activate, addr,
 477                                         ODEBUG_STATE_NOTAVAILABLE);
 478                 return ret ? 0 : -EINVAL;
 479         }
 480         return 0;
 481 }
 482 EXPORT_SYMBOL_GPL(debug_object_activate);
 483
 484 /**
 485  * debug_object_deactivate - debug checks when an object is deactivated
 486  * @addr:       address of the object
 487  * @descr:      pointer to an object specific debug description structure
 488  */
 489 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
 490 {
 491         struct debug_bucket *db;
 492         struct debug_obj *obj;
 493         unsigned long flags;
 494
 495         if (!debug_objects_enabled)
 496                 return;
 497
 498         db = get_bucket((unsigned long) addr);
 499
 500         raw_spin_lock_irqsave(&db->lock, flags);
 501
 502         obj = lookup_object(addr, db);
 503         if (obj) {
 504                 switch (obj->state) {
 505                 case ODEBUG_STATE_INIT:
 506                 case ODEBUG_STATE_INACTIVE:
 507                 case ODEBUG_STATE_ACTIVE:
 508                         if (!obj->astate)
 509                                 obj->state = ODEBUG_STATE_INACTIVE;
 510                         else
 511                                 debug_print_object(obj, "deactivate");
 512                         break;
 513
 514                 case ODEBUG_STATE_DESTROYED:
 515                         debug_print_object(obj, "deactivate");
 516                         break;
 517                 default:
 518                         break;
 519                 }
 520         } else {
 521                 struct debug_obj o = { .object = addr,
 522                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 523                                        .descr = descr };
 524
 525                 debug_print_object(&o, "deactivate");
 526         }
 527
 528         raw_spin_unlock_irqrestore(&db->lock, flags);
 529 }
 530 EXPORT_SYMBOL_GPL(debug_object_deactivate);
 531
 532 /**
 533  * debug_object_destroy - debug checks when an object is destroyed
 534  * @addr:       address of the object
 535  * @descr:      pointer to an object specific debug description structure
 536  */
 537 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
 538 {
 539         enum debug_obj_state state;
 540         struct debug_bucket *db;
 541         struct debug_obj *obj;
 542         unsigned long flags;
 543
 544         if (!debug_objects_enabled)
 545                 return;
 546
 547         db = get_bucket((unsigned long) addr);
 548
 549         raw_spin_lock_irqsave(&db->lock, flags);
 550
 551         obj = lookup_object(addr, db);
 552         if (!obj)
 553                 goto out_unlock;
 554
 555         switch (obj->state) {
 556         case ODEBUG_STATE_NONE:
 557         case ODEBUG_STATE_INIT:
 558         case ODEBUG_STATE_INACTIVE:
 559                 obj->state = ODEBUG_STATE_DESTROYED;
 560                 break;
 561         case ODEBUG_STATE_ACTIVE:
 562                 debug_print_object(obj, "destroy");
 563                 state = obj->state;
 564                 raw_spin_unlock_irqrestore(&db->lock, flags);
 565                 debug_object_fixup(descr->fixup_destroy, addr, state);
 566                 return;
 567
 568         case ODEBUG_STATE_DESTROYED:
 569                 debug_print_object(obj, "destroy");
 570                 break;
 571         default:
 572                 break;
 573         }
 574 out_unlock:
 575         raw_spin_unlock_irqrestore(&db->lock, flags);
 576 }
 577 EXPORT_SYMBOL_GPL(debug_object_destroy);
 578
 579 /**
 580  * debug_object_free - debug checks when an object is freed
 581  * @addr:       address of the object
 582  * @descr:      pointer to an object specific debug description structure
 583  */
 584 void debug_object_free(void *addr, struct debug_obj_descr *descr)
 585 {
 586         enum debug_obj_state state;
 587         struct debug_bucket *db;
 588         struct debug_obj *obj;
 589         unsigned long flags;
 590
 591         if (!debug_objects_enabled)
 592                 return;
 593
 594         db = get_bucket((unsigned long) addr);
 595
 596         raw_spin_lock_irqsave(&db->lock, flags);
 597
 598         obj = lookup_object(addr, db);
 599         if (!obj)
 600                 goto out_unlock;
 601
 602         switch (obj->state) {
 603         case ODEBUG_STATE_ACTIVE:
 604                 debug_print_object(obj, "free");
 605                 state = obj->state;
 606                 raw_spin_unlock_irqrestore(&db->lock, flags);
 607                 debug_object_fixup(descr->fixup_free, addr, state);
 608                 return;
 609         default:
 610                 hlist_del(&obj->node);
 611                 raw_spin_unlock_irqrestore(&db->lock, flags);
 612                 free_object(obj);
 613                 return;
 614         }
 615 out_unlock:
 616         raw_spin_unlock_irqrestore(&db->lock, flags);
 617 }
 618 EXPORT_SYMBOL_GPL(debug_object_free);
 619
 620 /**
 621  * debug_object_assert_init - debug checks when object should be init-ed
 622  * @addr:       address of the object
 623  * @descr:      pointer to an object specific debug description structure
 624  */
 625 void debug_object_assert_init(void *addr, struct debug_obj_descr *descr)
 626 {
 627         struct debug_bucket *db;
 628         struct debug_obj *obj;
 629         unsigned long flags;
 630
 631         if (!debug_objects_enabled)
 632                 return;
 633
 634         db = get_bucket((unsigned long) addr);
 635
 636         raw_spin_lock_irqsave(&db->lock, flags);
 637
 638         obj = lookup_object(addr, db);
 639         if (!obj) {
 640                 struct debug_obj o = { .object = addr,
 641                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 642                                        .descr = descr };
 643
 644                 raw_spin_unlock_irqrestore(&db->lock, flags);
 645                 /*
 646                  * Maybe the object is static, and we let the type specific
 647                  * code confirm. Track this static object if true, else invoke
 648                  * fixup.
 649                  */
 650                 if (descr->is_static_object && descr->is_static_object(addr)) {
 651                         /* Track this static object */
 652                         debug_object_init(addr, descr);
 653                 } else {
 654                         debug_print_object(&o, "assert_init");
 655                         debug_object_fixup(descr->fixup_assert_init, addr,
 656                                            ODEBUG_STATE_NOTAVAILABLE);
 657                 }
 658                 return;
 659         }
 660
 661         raw_spin_unlock_irqrestore(&db->lock, flags);
 662 }
 663 EXPORT_SYMBOL_GPL(debug_object_assert_init);
 664
 665 /**
 666  * debug_object_active_state - debug checks object usage state machine
 667  * @addr:       address of the object
 668  * @descr:      pointer to an object specific debug description structure
 669  * @expect:     expected state
 670  * @next:       state to move to if expected state is found
 671  */
 672 void
 673 debug_object_active_state(void *addr, struct debug_obj_descr *descr,
 674                           unsigned int expect, unsigned int next)
 675 {
 676         struct debug_bucket *db;
 677         struct debug_obj *obj;
 678         unsigned long flags;
 679
 680         if (!debug_objects_enabled)
 681                 return;
 682
 683         db = get_bucket((unsigned long) addr);
 684
 685         raw_spin_lock_irqsave(&db->lock, flags);
 686
 687         obj = lookup_object(addr, db);
 688         if (obj) {
 689                 switch (obj->state) {
 690                 case ODEBUG_STATE_ACTIVE:
 691                         if (obj->astate == expect)
 692                                 obj->astate = next;
 693                         else
 694                                 debug_print_object(obj, "active_state");
 695                         break;
 696
 697                 default:
 698                         debug_print_object(obj, "active_state");
 699                         break;
 700                 }
 701         } else {
 702                 struct debug_obj o = { .object = addr,
 703                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 704                                        .descr = descr };
 705
 706                 debug_print_object(&o, "active_state");
 707         }
 708
 709         raw_spin_unlock_irqrestore(&db->lock, flags);
 710 }
 711 EXPORT_SYMBOL_GPL(debug_object_active_state);
 712
 713 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 714 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
 715 {
 716         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
 717         struct hlist_node *tmp;
 718         HLIST_HEAD(freelist);
 719         struct debug_obj_descr *descr;
 720         enum debug_obj_state state;
 721         struct debug_bucket *db;
 722         struct debug_obj *obj;
 723         int cnt;
 724
 725         saddr = (unsigned long) address;
 726         eaddr = saddr + size;
 727         paddr = saddr & ODEBUG_CHUNK_MASK;
 728         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
 729         chunks >>= ODEBUG_CHUNK_SHIFT;
 730
 731         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
 732                 db = get_bucket(paddr);
 733
 734 repeat:
 735                 cnt = 0;
 736                 raw_spin_lock_irqsave(&db->lock, flags);
 737                 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
 738                         cnt++;
 739                         oaddr = (unsigned long) obj->object;
 740                         if (oaddr < saddr || oaddr >= eaddr)
 741                                 continue;
 742
 743                         switch (obj->state) {
 744                         case ODEBUG_STATE_ACTIVE:
 745                                 debug_print_object(obj, "free");
 746                                 descr = obj->descr;
 747                                 state = obj->state;
 748                                 raw_spin_unlock_irqrestore(&db->lock, flags);
 749                                 debug_object_fixup(descr->fixup_free,
 750                                                    (void *) oaddr, state);
 751                                 goto repeat;
 752                         default:
 753                                 hlist_del(&obj->node);
 754                                 hlist_add_head(&obj->node, &freelist);
 755                                 break;
 756                         }
 757                 }
 758                 raw_spin_unlock_irqrestore(&db->lock, flags);
 759
 760                 /* Now free them */
 761                 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
 762                         hlist_del(&obj->node);
 763                         free_object(obj);
 764                 }
 765
 766                 if (cnt > debug_objects_maxchain)
 767                         debug_objects_maxchain = cnt;
 768         }
 769 }
 770
 771 void debug_check_no_obj_freed(const void *address, unsigned long size)
 772 {
 773         if (debug_objects_enabled)
 774                 __debug_check_no_obj_freed(address, size);
 775 }
 776 #endif
 777
 778 #ifdef CONFIG_DEBUG_FS
 779
 780 static int debug_stats_show(struct seq_file *m, void *v)
 781 {
 782         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
 783         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
 784         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
 785         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
 786         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
 787         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
 788         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
 789         seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
 790         seq_printf(m, "objs_freed    :%d\n", debug_objects_freed);
 791         return 0;
 792 }
 793
 794 static int debug_stats_open(struct inode *inode, struct file *filp)
 795 {
 796         return single_open(filp, debug_stats_show, NULL);
 797 }
 798
 799 static const struct file_operations debug_stats_fops = {
 800         .open           = debug_stats_open,
 801         .read           = seq_read,
 802         .llseek         = seq_lseek,
 803         .release        = single_release,
 804 };
 805
 806 static int __init debug_objects_init_debugfs(void)
 807 {
 808         struct dentry *dbgdir, *dbgstats;
 809
 810         if (!debug_objects_enabled)
 811                 return 0;
 812
 813         dbgdir = debugfs_create_dir("debug_objects", NULL);
 814         if (!dbgdir)
 815                 return -ENOMEM;
 816
 817         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
 818                                        &debug_stats_fops);
 819         if (!dbgstats)
 820                 goto err;
 821
 822         return 0;
 823
 824 err:
 825         debugfs_remove(dbgdir);
 826
 827         return -ENOMEM;
 828 }
 829 __initcall(debug_objects_init_debugfs);
 830
 831 #else
 832 static inline void debug_objects_init_debugfs(void) { }
 833 #endif
 834
 835 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
 836
 837 /* Random data structure for the self test */
 838 struct self_test {
 839         unsigned long   dummy1[6];
 840         int             static_init;
 841         unsigned long   dummy2[3];
 842 };
 843
 844 static __initdata struct debug_obj_descr descr_type_test;
 845
 846 static bool __init is_static_object(void *addr)
 847 {
 848         struct self_test *obj = addr;
 849
 850         return obj->static_init;
 851 }
 852
 853 /*
 854  * fixup_init is called when:
 855  * - an active object is initialized
 856  */
 857 static bool __init fixup_init(void *addr, enum debug_obj_state state)
 858 {
 859         struct self_test *obj = addr;
 860
 861         switch (state) {
 862         case ODEBUG_STATE_ACTIVE:
 863                 debug_object_deactivate(obj, &descr_type_test);
 864                 debug_object_init(obj, &descr_type_test);
 865                 return true;
 866         default:
 867                 return false;
 868         }
 869 }
 870
 871 /*
 872  * fixup_activate is called when:
 873  * - an active object is activated
 874  * - an unknown non-static object is activated
 875  */
 876 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
 877 {
 878         struct self_test *obj = addr;
 879
 880         switch (state) {
 881         case ODEBUG_STATE_NOTAVAILABLE:
 882                 return true;
 883         case ODEBUG_STATE_ACTIVE:
 884                 debug_object_deactivate(obj, &descr_type_test);
 885                 debug_object_activate(obj, &descr_type_test);
 886                 return true;
 887
 888         default:
 889                 return false;
 890         }
 891 }
 892
 893 /*
 894  * fixup_destroy is called when:
 895  * - an active object is destroyed
 896  */
 897 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
 898 {
 899         struct self_test *obj = addr;
 900
 901         switch (state) {
 902         case ODEBUG_STATE_ACTIVE:
 903                 debug_object_deactivate(obj, &descr_type_test);
 904                 debug_object_destroy(obj, &descr_type_test);
 905                 return true;
 906         default:
 907                 return false;
 908         }
 909 }
 910
 911 /*
 912  * fixup_free is called when:
 913  * - an active object is freed
 914  */
 915 static bool __init fixup_free(void *addr, enum debug_obj_state state)
 916 {
 917         struct self_test *obj = addr;
 918
 919         switch (state) {
 920         case ODEBUG_STATE_ACTIVE:
 921                 debug_object_deactivate(obj, &descr_type_test);
 922                 debug_object_free(obj, &descr_type_test);
 923                 return true;
 924         default:
 925                 return false;
 926         }
 927 }
 928
 929 static int __init
 930 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
 931 {
 932         struct debug_bucket *db;
 933         struct debug_obj *obj;
 934         unsigned long flags;
 935         int res = -EINVAL;
 936
 937         db = get_bucket((unsigned long) addr);
 938
 939         raw_spin_lock_irqsave(&db->lock, flags);
 940
 941         obj = lookup_object(addr, db);
 942         if (!obj && state != ODEBUG_STATE_NONE) {
 943                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
 944                 goto out;
 945         }
 946         if (obj && obj->state != state) {
 947                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
 948                        obj->state, state);
 949                 goto out;
 950         }
 951         if (fixups != debug_objects_fixups) {
 952                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
 953                        fixups, debug_objects_fixups);
 954                 goto out;
 955         }
 956         if (warnings != debug_objects_warnings) {
 957                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
 958                        warnings, debug_objects_warnings);
 959                 goto out;
 960         }
 961         res = 0;
 962 out:
 963         raw_spin_unlock_irqrestore(&db->lock, flags);
 964         if (res)
 965                 debug_objects_enabled = 0;
 966         return res;
 967 }
 968
 969 static __initdata struct debug_obj_descr descr_type_test = {
 970         .name                   = "selftest",
 971         .is_static_object       = is_static_object,
 972         .fixup_init             = fixup_init,
 973         .fixup_activate         = fixup_activate,
 974         .fixup_destroy          = fixup_destroy,
 975         .fixup_free             = fixup_free,
 976 };
 977
 978 static __initdata struct self_test obj = { .static_init = 0 };
 979
 980 static void __init debug_objects_selftest(void)
 981 {
 982         int fixups, oldfixups, warnings, oldwarnings;
 983         unsigned long flags;
 984
 985         local_irq_save(flags);
 986
 987         fixups = oldfixups = debug_objects_fixups;
 988         warnings = oldwarnings = debug_objects_warnings;
 989         descr_test = &descr_type_test;
 990
 991         debug_object_init(&obj, &descr_type_test);
 992         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
 993                 goto out;
 994         debug_object_activate(&obj, &descr_type_test);
 995         if (check_results(&obj, ODEBUG_STATE_ACTIVE, 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_deactivate(&obj, &descr_type_test);
1001         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1002                 goto out;
1003         debug_object_destroy(&obj, &descr_type_test);
1004         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1005                 goto out;
1006         debug_object_init(&obj, &descr_type_test);
1007         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1008                 goto out;
1009         debug_object_activate(&obj, &descr_type_test);
1010         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1011                 goto out;
1012         debug_object_deactivate(&obj, &descr_type_test);
1013         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1014                 goto out;
1015         debug_object_free(&obj, &descr_type_test);
1016         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1017                 goto out;
1018
1019         obj.static_init = 1;
1020         debug_object_activate(&obj, &descr_type_test);
1021         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1022                 goto out;
1023         debug_object_init(&obj, &descr_type_test);
1024         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1025                 goto out;
1026         debug_object_free(&obj, &descr_type_test);
1027         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1028                 goto out;
1029
1030 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1031         debug_object_init(&obj, &descr_type_test);
1032         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1033                 goto out;
1034         debug_object_activate(&obj, &descr_type_test);
1035         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1036                 goto out;
1037         __debug_check_no_obj_freed(&obj, sizeof(obj));
1038         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1039                 goto out;
1040 #endif
1041         pr_info("selftest passed\n");
1042
1043 out:
1044         debug_objects_fixups = oldfixups;
1045         debug_objects_warnings = oldwarnings;
1046         descr_test = NULL;
1047
1048         local_irq_restore(flags);
1049 }
1050 #else
1051 static inline void debug_objects_selftest(void) { }
1052 #endif
1053
1054 /*
1055  * Called during early boot to initialize the hash buckets and link
1056  * the static object pool objects into the poll list. After this call
1057  * the object tracker is fully operational.
1058  */
1059 void __init debug_objects_early_init(void)
1060 {
1061         int i;
1062
1063         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1064                 raw_spin_lock_init(&obj_hash[i].lock);
1065
1066         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1067                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1068 }
1069
1070 /*
1071  * Convert the statically allocated objects to dynamic ones:
1072  */
1073 static int __init debug_objects_replace_static_objects(void)
1074 {
1075         struct debug_bucket *db = obj_hash;
1076         struct hlist_node *tmp;
1077         struct debug_obj *obj, *new;
1078         HLIST_HEAD(objects);
1079         int i, cnt = 0;
1080
1081         for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1082                 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1083                 if (!obj)
1084                         goto free;
1085                 kmemleak_ignore(obj);
1086                 hlist_add_head(&obj->node, &objects);
1087         }
1088
1089         /*
1090          * When debug_objects_mem_init() is called we know that only
1091          * one CPU is up, so disabling interrupts is enough
1092          * protection. This avoids the lockdep hell of lock ordering.
1093          */
1094         local_irq_disable();
1095
1096         /* Remove the statically allocated objects from the pool */
1097         hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1098                 hlist_del(&obj->node);
1099         /* Move the allocated objects to the pool */
1100         hlist_move_list(&objects, &obj_pool);
1101
1102         /* Replace the active object references */
1103         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1104                 hlist_move_list(&db->list, &objects);
1105
1106                 hlist_for_each_entry(obj, &objects, node) {
1107                         new = hlist_entry(obj_pool.first, typeof(*obj), node);
1108                         hlist_del(&new->node);
1109                         /* copy object data */
1110                         *new = *obj;
1111                         hlist_add_head(&new->node, &db->list);
1112                         cnt++;
1113                 }
1114         }
1115         local_irq_enable();
1116
1117         pr_debug("%d of %d active objects replaced\n",
1118                  cnt, obj_pool_used);
1119         return 0;
1120 free:
1121         hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1122                 hlist_del(&obj->node);
1123                 kmem_cache_free(obj_cache, obj);
1124         }
1125         return -ENOMEM;
1126 }
1127
1128 /*
1129  * Called after the kmem_caches are functional to setup a dedicated
1130  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1131  * prevents that the debug code is called on kmem_cache_free() for the
1132  * debug tracker objects to avoid recursive calls.
1133  */
1134 void __init debug_objects_mem_init(void)
1135 {
1136         if (!debug_objects_enabled)
1137                 return;
1138
1139         obj_cache = kmem_cache_create("debug_objects_cache",
1140                                       sizeof (struct debug_obj), 0,
1141                                       SLAB_DEBUG_OBJECTS, NULL);
1142
1143         if (!obj_cache || debug_objects_replace_static_objects()) {
1144                 debug_objects_enabled = 0;
1145                 if (obj_cache)
1146                         kmem_cache_destroy(obj_cache);
1147                 pr_warn("out of memory.\n");
1148         } else
1149                 debug_objects_selftest();
1150
1151         /*
1152          * Increase the thresholds for allocating and freeing objects
1153          * according to the number of possible CPUs available in the system.
1154          */
1155         debug_objects_pool_size += num_possible_cpus() * 32;
1156         debug_objects_pool_min_level += num_possible_cpus() * 4;
1157 }