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 #include <linux/debugobjects.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/debugfs.h>
  14 #include <linux/hash.h>
  15
  16 #define ODEBUG_HASH_BITS        14
  17 #define ODEBUG_HASH_SIZE        (1 << ODEBUG_HASH_BITS)
  18
  19 #define ODEBUG_POOL_SIZE        512
  20 #define ODEBUG_POOL_MIN_LEVEL   256
  21
  22 #define ODEBUG_CHUNK_SHIFT      PAGE_SHIFT
  23 #define ODEBUG_CHUNK_SIZE       (1 << ODEBUG_CHUNK_SHIFT)
  24 #define ODEBUG_CHUNK_MASK       (~(ODEBUG_CHUNK_SIZE - 1))
  25
  26 struct debug_bucket {
  27         struct hlist_head       list;
  28         spinlock_t              lock;
  29 };
  30
  31 static struct debug_bucket      obj_hash[ODEBUG_HASH_SIZE];
  32
  33 static struct debug_obj         obj_static_pool[ODEBUG_POOL_SIZE];
  34
  35 static DEFINE_SPINLOCK(pool_lock);
  36
  37 static HLIST_HEAD(obj_pool);
  38
  39 static int                      obj_pool_min_free = ODEBUG_POOL_SIZE;
  40 static int                      obj_pool_free = ODEBUG_POOL_SIZE;
  41 static int                      obj_pool_used;
  42 static int                      obj_pool_max_used;
  43 static struct kmem_cache        *obj_cache;
  44
  45 static int                      debug_objects_maxchain __read_mostly;
  46 static int                      debug_objects_fixups __read_mostly;
  47 static int                      debug_objects_warnings __read_mostly;
  48 static int                      debug_objects_enabled __read_mostly;
  49 static struct debug_obj_descr   *descr_test  __read_mostly;
  50
  51 static int __init enable_object_debug(char *str)
  52 {
  53         debug_objects_enabled = 1;
  54         return 0;
  55 }
  56 early_param("debug_objects", enable_object_debug);
  57
  58 static const char *obj_states[ODEBUG_STATE_MAX] = {
  59         [ODEBUG_STATE_NONE]             = "none",
  60         [ODEBUG_STATE_INIT]             = "initialized",
  61         [ODEBUG_STATE_INACTIVE]         = "inactive",
  62         [ODEBUG_STATE_ACTIVE]           = "active",
  63         [ODEBUG_STATE_DESTROYED]        = "destroyed",
  64         [ODEBUG_STATE_NOTAVAILABLE]     = "not available",
  65 };
  66
  67 static int fill_pool(void)
  68 {
  69         gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
  70         struct debug_obj *new;
  71         unsigned long flags;
  72
  73         if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
  74                 return obj_pool_free;
  75
  76         if (unlikely(!obj_cache))
  77                 return obj_pool_free;
  78
  79         while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
  80
  81                 new = kmem_cache_zalloc(obj_cache, gfp);
  82                 if (!new)
  83                         return obj_pool_free;
  84
  85                 spin_lock_irqsave(&pool_lock, flags);
  86                 hlist_add_head(&new->node, &obj_pool);
  87                 obj_pool_free++;
  88                 spin_unlock_irqrestore(&pool_lock, flags);
  89         }
  90         return obj_pool_free;
  91 }
  92
  93 /*
  94  * Lookup an object in the hash bucket.
  95  */
  96 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
  97 {
  98         struct hlist_node *node;
  99         struct debug_obj *obj;
 100         int cnt = 0;
 101
 102         hlist_for_each_entry(obj, node, &b->list, node) {
 103                 cnt++;
 104                 if (obj->object == addr)
 105                         return obj;
 106         }
 107         if (cnt > debug_objects_maxchain)
 108                 debug_objects_maxchain = cnt;
 109
 110         return NULL;
 111 }
 112
 113 /*
 114  * Allocate a new object. If the pool is empty, switch off the debugger.
 115  */
 116 static struct debug_obj *
 117 alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
 118 {
 119         struct debug_obj *obj = NULL;
 120
 121         spin_lock(&pool_lock);
 122         if (obj_pool.first) {
 123                 obj         = hlist_entry(obj_pool.first, typeof(*obj), node);
 124
 125                 obj->object = addr;
 126                 obj->descr  = descr;
 127                 obj->state  = ODEBUG_STATE_NONE;
 128                 hlist_del(&obj->node);
 129
 130                 hlist_add_head(&obj->node, &b->list);
 131
 132                 obj_pool_used++;
 133                 if (obj_pool_used > obj_pool_max_used)
 134                         obj_pool_max_used = obj_pool_used;
 135
 136                 obj_pool_free--;
 137                 if (obj_pool_free < obj_pool_min_free)
 138                         obj_pool_min_free = obj_pool_free;
 139         }
 140         spin_unlock(&pool_lock);
 141
 142         return obj;
 143 }
 144
 145 /*
 146  * Put the object back into the pool or give it back to kmem_cache:
 147  */
 148 static void free_object(struct debug_obj *obj)
 149 {
 150         unsigned long idx = (unsigned long)(obj - obj_static_pool);
 151
 152         if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
 153                 spin_lock(&pool_lock);
 154                 hlist_add_head(&obj->node, &obj_pool);
 155                 obj_pool_free++;
 156                 obj_pool_used--;
 157                 spin_unlock(&pool_lock);
 158         } else {
 159                 spin_lock(&pool_lock);
 160                 obj_pool_used--;
 161                 spin_unlock(&pool_lock);
 162                 kmem_cache_free(obj_cache, obj);
 163         }
 164 }
 165
 166 /*
 167  * We run out of memory. That means we probably have tons of objects
 168  * allocated.
 169  */
 170 static void debug_objects_oom(void)
 171 {
 172         struct debug_bucket *db = obj_hash;
 173         struct hlist_node *node, *tmp;
 174         struct debug_obj *obj;
 175         unsigned long flags;
 176         int i;
 177
 178         printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
 179
 180         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
 181                 spin_lock_irqsave(&db->lock, flags);
 182                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
 183                         hlist_del(&obj->node);
 184                         free_object(obj);
 185                 }
 186                 spin_unlock_irqrestore(&db->lock, flags);
 187         }
 188 }
 189
 190 /*
 191  * We use the pfn of the address for the hash. That way we can check
 192  * for freed objects simply by checking the affected bucket.
 193  */
 194 static struct debug_bucket *get_bucket(unsigned long addr)
 195 {
 196         unsigned long hash;
 197
 198         hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
 199         return &obj_hash[hash];
 200 }
 201
 202 static void debug_print_object(struct debug_obj *obj, char *msg)
 203 {
 204         static int limit;
 205
 206         if (limit < 5 && obj->descr != descr_test) {
 207                 limit++;
 208                 WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
 209                        obj_states[obj->state], obj->descr->name);
 210         }
 211         debug_objects_warnings++;
 212 }
 213
 214 /*
 215  * Try to repair the damage, so we have a better chance to get useful
 216  * debug output.
 217  */
 218 static void
 219 debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
 220                    void * addr, enum debug_obj_state state)
 221 {
 222         if (fixup)
 223                 debug_objects_fixups += fixup(addr, state);
 224 }
 225
 226 static void debug_object_is_on_stack(void *addr, int onstack)
 227 {
 228         int is_on_stack;
 229         static int limit;
 230
 231         if (limit > 4)
 232                 return;
 233
 234         is_on_stack = object_is_on_stack(addr);
 235         if (is_on_stack == onstack)
 236                 return;
 237
 238         limit++;
 239         if (is_on_stack)
 240                 printk(KERN_WARNING
 241                        "ODEBUG: object is on stack, but not annotated\n");
 242         else
 243                 printk(KERN_WARNING
 244                        "ODEBUG: object is not on stack, but annotated\n");
 245         WARN_ON(1);
 246 }
 247
 248 static void
 249 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
 250 {
 251         enum debug_obj_state state;
 252         struct debug_bucket *db;
 253         struct debug_obj *obj;
 254         unsigned long flags;
 255
 256         fill_pool();
 257
 258         db = get_bucket((unsigned long) addr);
 259
 260         spin_lock_irqsave(&db->lock, flags);
 261
 262         obj = lookup_object(addr, db);
 263         if (!obj) {
 264                 obj = alloc_object(addr, db, descr);
 265                 if (!obj) {
 266                         debug_objects_enabled = 0;
 267                         spin_unlock_irqrestore(&db->lock, flags);
 268                         debug_objects_oom();
 269                         return;
 270                 }
 271                 debug_object_is_on_stack(addr, onstack);
 272         }
 273
 274         switch (obj->state) {
 275         case ODEBUG_STATE_NONE:
 276         case ODEBUG_STATE_INIT:
 277         case ODEBUG_STATE_INACTIVE:
 278                 obj->state = ODEBUG_STATE_INIT;
 279                 break;
 280
 281         case ODEBUG_STATE_ACTIVE:
 282                 debug_print_object(obj, "init");
 283                 state = obj->state;
 284                 spin_unlock_irqrestore(&db->lock, flags);
 285                 debug_object_fixup(descr->fixup_init, addr, state);
 286                 return;
 287
 288         case ODEBUG_STATE_DESTROYED:
 289                 debug_print_object(obj, "init");
 290                 break;
 291         default:
 292                 break;
 293         }
 294
 295         spin_unlock_irqrestore(&db->lock, flags);
 296 }
 297
 298 /**
 299  * debug_object_init - debug checks when an object is initialized
 300  * @addr:       address of the object
 301  * @descr:      pointer to an object specific debug description structure
 302  */
 303 void debug_object_init(void *addr, struct debug_obj_descr *descr)
 304 {
 305         if (!debug_objects_enabled)
 306                 return;
 307
 308         __debug_object_init(addr, descr, 0);
 309 }
 310
 311 /**
 312  * debug_object_init_on_stack - debug checks when an object on stack is
 313  *                              initialized
 314  * @addr:       address of the object
 315  * @descr:      pointer to an object specific debug description structure
 316  */
 317 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
 318 {
 319         if (!debug_objects_enabled)
 320                 return;
 321
 322         __debug_object_init(addr, descr, 1);
 323 }
 324
 325 /**
 326  * debug_object_activate - debug checks when an object is activated
 327  * @addr:       address of the object
 328  * @descr:      pointer to an object specific debug description structure
 329  */
 330 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
 331 {
 332         enum debug_obj_state state;
 333         struct debug_bucket *db;
 334         struct debug_obj *obj;
 335         unsigned long flags;
 336
 337         if (!debug_objects_enabled)
 338                 return;
 339
 340         db = get_bucket((unsigned long) addr);
 341
 342         spin_lock_irqsave(&db->lock, flags);
 343
 344         obj = lookup_object(addr, db);
 345         if (obj) {
 346                 switch (obj->state) {
 347                 case ODEBUG_STATE_INIT:
 348                 case ODEBUG_STATE_INACTIVE:
 349                         obj->state = ODEBUG_STATE_ACTIVE;
 350                         break;
 351
 352                 case ODEBUG_STATE_ACTIVE:
 353                         debug_print_object(obj, "activate");
 354                         state = obj->state;
 355                         spin_unlock_irqrestore(&db->lock, flags);
 356                         debug_object_fixup(descr->fixup_activate, addr, state);
 357                         return;
 358
 359                 case ODEBUG_STATE_DESTROYED:
 360                         debug_print_object(obj, "activate");
 361                         break;
 362                 default:
 363                         break;
 364                 }
 365                 spin_unlock_irqrestore(&db->lock, flags);
 366                 return;
 367         }
 368
 369         spin_unlock_irqrestore(&db->lock, flags);
 370         /*
 371          * This happens when a static object is activated. We
 372          * let the type specific code decide whether this is
 373          * true or not.
 374          */
 375         debug_object_fixup(descr->fixup_activate, addr,
 376                            ODEBUG_STATE_NOTAVAILABLE);
 377 }
 378
 379 /**
 380  * debug_object_deactivate - debug checks when an object is deactivated
 381  * @addr:       address of the object
 382  * @descr:      pointer to an object specific debug description structure
 383  */
 384 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
 385 {
 386         struct debug_bucket *db;
 387         struct debug_obj *obj;
 388         unsigned long flags;
 389
 390         if (!debug_objects_enabled)
 391                 return;
 392
 393         db = get_bucket((unsigned long) addr);
 394
 395         spin_lock_irqsave(&db->lock, flags);
 396
 397         obj = lookup_object(addr, db);
 398         if (obj) {
 399                 switch (obj->state) {
 400                 case ODEBUG_STATE_INIT:
 401                 case ODEBUG_STATE_INACTIVE:
 402                 case ODEBUG_STATE_ACTIVE:
 403                         obj->state = ODEBUG_STATE_INACTIVE;
 404                         break;
 405
 406                 case ODEBUG_STATE_DESTROYED:
 407                         debug_print_object(obj, "deactivate");
 408                         break;
 409                 default:
 410                         break;
 411                 }
 412         } else {
 413                 struct debug_obj o = { .object = addr,
 414                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 415                                        .descr = descr };
 416
 417                 debug_print_object(&o, "deactivate");
 418         }
 419
 420         spin_unlock_irqrestore(&db->lock, flags);
 421 }
 422
 423 /**
 424  * debug_object_destroy - debug checks when an object is destroyed
 425  * @addr:       address of the object
 426  * @descr:      pointer to an object specific debug description structure
 427  */
 428 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
 429 {
 430         enum debug_obj_state state;
 431         struct debug_bucket *db;
 432         struct debug_obj *obj;
 433         unsigned long flags;
 434
 435         if (!debug_objects_enabled)
 436                 return;
 437
 438         db = get_bucket((unsigned long) addr);
 439
 440         spin_lock_irqsave(&db->lock, flags);
 441
 442         obj = lookup_object(addr, db);
 443         if (!obj)
 444                 goto out_unlock;
 445
 446         switch (obj->state) {
 447         case ODEBUG_STATE_NONE:
 448         case ODEBUG_STATE_INIT:
 449         case ODEBUG_STATE_INACTIVE:
 450                 obj->state = ODEBUG_STATE_DESTROYED;
 451                 break;
 452         case ODEBUG_STATE_ACTIVE:
 453                 debug_print_object(obj, "destroy");
 454                 state = obj->state;
 455                 spin_unlock_irqrestore(&db->lock, flags);
 456                 debug_object_fixup(descr->fixup_destroy, addr, state);
 457                 return;
 458
 459         case ODEBUG_STATE_DESTROYED:
 460                 debug_print_object(obj, "destroy");
 461                 break;
 462         default:
 463                 break;
 464         }
 465 out_unlock:
 466         spin_unlock_irqrestore(&db->lock, flags);
 467 }
 468
 469 /**
 470  * debug_object_free - debug checks when an object is freed
 471  * @addr:       address of the object
 472  * @descr:      pointer to an object specific debug description structure
 473  */
 474 void debug_object_free(void *addr, struct debug_obj_descr *descr)
 475 {
 476         enum debug_obj_state state;
 477         struct debug_bucket *db;
 478         struct debug_obj *obj;
 479         unsigned long flags;
 480
 481         if (!debug_objects_enabled)
 482                 return;
 483
 484         db = get_bucket((unsigned long) addr);
 485
 486         spin_lock_irqsave(&db->lock, flags);
 487
 488         obj = lookup_object(addr, db);
 489         if (!obj)
 490                 goto out_unlock;
 491
 492         switch (obj->state) {
 493         case ODEBUG_STATE_ACTIVE:
 494                 debug_print_object(obj, "free");
 495                 state = obj->state;
 496                 spin_unlock_irqrestore(&db->lock, flags);
 497                 debug_object_fixup(descr->fixup_free, addr, state);
 498                 return;
 499         default:
 500                 hlist_del(&obj->node);
 501                 free_object(obj);
 502                 break;
 503         }
 504 out_unlock:
 505         spin_unlock_irqrestore(&db->lock, flags);
 506 }
 507
 508 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 509 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
 510 {
 511         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
 512         struct hlist_node *node, *tmp;
 513         struct debug_obj_descr *descr;
 514         enum debug_obj_state state;
 515         struct debug_bucket *db;
 516         struct debug_obj *obj;
 517         int cnt;
 518
 519         saddr = (unsigned long) address;
 520         eaddr = saddr + size;
 521         paddr = saddr & ODEBUG_CHUNK_MASK;
 522         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
 523         chunks >>= ODEBUG_CHUNK_SHIFT;
 524
 525         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
 526                 db = get_bucket(paddr);
 527
 528 repeat:
 529                 cnt = 0;
 530                 spin_lock_irqsave(&db->lock, flags);
 531                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
 532                         cnt++;
 533                         oaddr = (unsigned long) obj->object;
 534                         if (oaddr < saddr || oaddr >= eaddr)
 535                                 continue;
 536
 537                         switch (obj->state) {
 538                         case ODEBUG_STATE_ACTIVE:
 539                                 debug_print_object(obj, "free");
 540                                 descr = obj->descr;
 541                                 state = obj->state;
 542                                 spin_unlock_irqrestore(&db->lock, flags);
 543                                 debug_object_fixup(descr->fixup_free,
 544                                                    (void *) oaddr, state);
 545                                 goto repeat;
 546                         default:
 547                                 hlist_del(&obj->node);
 548                                 free_object(obj);
 549                                 break;
 550                         }
 551                 }
 552                 spin_unlock_irqrestore(&db->lock, flags);
 553                 if (cnt > debug_objects_maxchain)
 554                         debug_objects_maxchain = cnt;
 555         }
 556 }
 557
 558 void debug_check_no_obj_freed(const void *address, unsigned long size)
 559 {
 560         if (debug_objects_enabled)
 561                 __debug_check_no_obj_freed(address, size);
 562 }
 563 #endif
 564
 565 #ifdef CONFIG_DEBUG_FS
 566
 567 static int debug_stats_show(struct seq_file *m, void *v)
 568 {
 569         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
 570         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
 571         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
 572         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
 573         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
 574         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
 575         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
 576         return 0;
 577 }
 578
 579 static int debug_stats_open(struct inode *inode, struct file *filp)
 580 {
 581         return single_open(filp, debug_stats_show, NULL);
 582 }
 583
 584 static const struct file_operations debug_stats_fops = {
 585         .open           = debug_stats_open,
 586         .read           = seq_read,
 587         .llseek         = seq_lseek,
 588         .release        = single_release,
 589 };
 590
 591 static int __init debug_objects_init_debugfs(void)
 592 {
 593         struct dentry *dbgdir, *dbgstats;
 594
 595         if (!debug_objects_enabled)
 596                 return 0;
 597
 598         dbgdir = debugfs_create_dir("debug_objects", NULL);
 599         if (!dbgdir)
 600                 return -ENOMEM;
 601
 602         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
 603                                        &debug_stats_fops);
 604         if (!dbgstats)
 605                 goto err;
 606
 607         return 0;
 608
 609 err:
 610         debugfs_remove(dbgdir);
 611
 612         return -ENOMEM;
 613 }
 614 __initcall(debug_objects_init_debugfs);
 615
 616 #else
 617 static inline void debug_objects_init_debugfs(void) { }
 618 #endif
 619
 620 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
 621
 622 /* Random data structure for the self test */
 623 struct self_test {
 624         unsigned long   dummy1[6];
 625         int             static_init;
 626         unsigned long   dummy2[3];
 627 };
 628
 629 static __initdata struct debug_obj_descr descr_type_test;
 630
 631 /*
 632  * fixup_init is called when:
 633  * - an active object is initialized
 634  */
 635 static int __init fixup_init(void *addr, enum debug_obj_state state)
 636 {
 637         struct self_test *obj = addr;
 638
 639         switch (state) {
 640         case ODEBUG_STATE_ACTIVE:
 641                 debug_object_deactivate(obj, &descr_type_test);
 642                 debug_object_init(obj, &descr_type_test);
 643                 return 1;
 644         default:
 645                 return 0;
 646         }
 647 }
 648
 649 /*
 650  * fixup_activate is called when:
 651  * - an active object is activated
 652  * - an unknown object is activated (might be a statically initialized object)
 653  */
 654 static int __init fixup_activate(void *addr, enum debug_obj_state state)
 655 {
 656         struct self_test *obj = addr;
 657
 658         switch (state) {
 659         case ODEBUG_STATE_NOTAVAILABLE:
 660                 if (obj->static_init == 1) {
 661                         debug_object_init(obj, &descr_type_test);
 662                         debug_object_activate(obj, &descr_type_test);
 663                         /*
 664                          * Real code should return 0 here ! This is
 665                          * not a fixup of some bad behaviour. We
 666                          * merily call the debug_init function to keep
 667                          * track of the object.
 668                          */
 669                         return 1;
 670                 } else {
 671                         /* Real code needs to emit a warning here */
 672                 }
 673                 return 0;
 674
 675         case ODEBUG_STATE_ACTIVE:
 676                 debug_object_deactivate(obj, &descr_type_test);
 677                 debug_object_activate(obj, &descr_type_test);
 678                 return 1;
 679
 680         default:
 681                 return 0;
 682         }
 683 }
 684
 685 /*
 686  * fixup_destroy is called when:
 687  * - an active object is destroyed
 688  */
 689 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
 690 {
 691         struct self_test *obj = addr;
 692
 693         switch (state) {
 694         case ODEBUG_STATE_ACTIVE:
 695                 debug_object_deactivate(obj, &descr_type_test);
 696                 debug_object_destroy(obj, &descr_type_test);
 697                 return 1;
 698         default:
 699                 return 0;
 700         }
 701 }
 702
 703 /*
 704  * fixup_free is called when:
 705  * - an active object is freed
 706  */
 707 static int __init fixup_free(void *addr, enum debug_obj_state state)
 708 {
 709         struct self_test *obj = addr;
 710
 711         switch (state) {
 712         case ODEBUG_STATE_ACTIVE:
 713                 debug_object_deactivate(obj, &descr_type_test);
 714                 debug_object_free(obj, &descr_type_test);
 715                 return 1;
 716         default:
 717                 return 0;
 718         }
 719 }
 720
 721 static int
 722 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
 723 {
 724         struct debug_bucket *db;
 725         struct debug_obj *obj;
 726         unsigned long flags;
 727         int res = -EINVAL;
 728
 729         db = get_bucket((unsigned long) addr);
 730
 731         spin_lock_irqsave(&db->lock, flags);
 732
 733         obj = lookup_object(addr, db);
 734         if (!obj && state != ODEBUG_STATE_NONE) {
 735                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
 736                 goto out;
 737         }
 738         if (obj && obj->state != state) {
 739                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
 740                        obj->state, state);
 741                 goto out;
 742         }
 743         if (fixups != debug_objects_fixups) {
 744                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
 745                        fixups, debug_objects_fixups);
 746                 goto out;
 747         }
 748         if (warnings != debug_objects_warnings) {
 749                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
 750                        warnings, debug_objects_warnings);
 751                 goto out;
 752         }
 753         res = 0;
 754 out:
 755         spin_unlock_irqrestore(&db->lock, flags);
 756         if (res)
 757                 debug_objects_enabled = 0;
 758         return res;
 759 }
 760
 761 static __initdata struct debug_obj_descr descr_type_test = {
 762         .name                   = "selftest",
 763         .fixup_init             = fixup_init,
 764         .fixup_activate         = fixup_activate,
 765         .fixup_destroy          = fixup_destroy,
 766         .fixup_free             = fixup_free,
 767 };
 768
 769 static __initdata struct self_test obj = { .static_init = 0 };
 770
 771 static void __init debug_objects_selftest(void)
 772 {
 773         int fixups, oldfixups, warnings, oldwarnings;
 774         unsigned long flags;
 775
 776         local_irq_save(flags);
 777
 778         fixups = oldfixups = debug_objects_fixups;
 779         warnings = oldwarnings = debug_objects_warnings;
 780         descr_test = &descr_type_test;
 781
 782         debug_object_init(&obj, &descr_type_test);
 783         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
 784                 goto out;
 785         debug_object_activate(&obj, &descr_type_test);
 786         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
 787                 goto out;
 788         debug_object_activate(&obj, &descr_type_test);
 789         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
 790                 goto out;
 791         debug_object_deactivate(&obj, &descr_type_test);
 792         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
 793                 goto out;
 794         debug_object_destroy(&obj, &descr_type_test);
 795         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
 796                 goto out;
 797         debug_object_init(&obj, &descr_type_test);
 798         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
 799                 goto out;
 800         debug_object_activate(&obj, &descr_type_test);
 801         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
 802                 goto out;
 803         debug_object_deactivate(&obj, &descr_type_test);
 804         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
 805                 goto out;
 806         debug_object_free(&obj, &descr_type_test);
 807         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
 808                 goto out;
 809
 810         obj.static_init = 1;
 811         debug_object_activate(&obj, &descr_type_test);
 812         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
 813                 goto out;
 814         debug_object_init(&obj, &descr_type_test);
 815         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
 816                 goto out;
 817         debug_object_free(&obj, &descr_type_test);
 818         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
 819                 goto out;
 820
 821 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 822         debug_object_init(&obj, &descr_type_test);
 823         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
 824                 goto out;
 825         debug_object_activate(&obj, &descr_type_test);
 826         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
 827                 goto out;
 828         __debug_check_no_obj_freed(&obj, sizeof(obj));
 829         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
 830                 goto out;
 831 #endif
 832         printk(KERN_INFO "ODEBUG: selftest passed\n");
 833
 834 out:
 835         debug_objects_fixups = oldfixups;
 836         debug_objects_warnings = oldwarnings;
 837         descr_test = NULL;
 838
 839         local_irq_restore(flags);
 840 }
 841 #else
 842 static inline void debug_objects_selftest(void) { }
 843 #endif
 844
 845 /*
 846  * Called during early boot to initialize the hash buckets and link
 847  * the static object pool objects into the poll list. After this call
 848  * the object tracker is fully operational.
 849  */
 850 void __init debug_objects_early_init(void)
 851 {
 852         int i;
 853
 854         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
 855                 spin_lock_init(&obj_hash[i].lock);
 856
 857         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
 858                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
 859 }
 860
 861 /*
 862  * Called after the kmem_caches are functional to setup a dedicated
 863  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
 864  * prevents that the debug code is called on kmem_cache_free() for the
 865  * debug tracker objects to avoid recursive calls.
 866  */
 867 void __init debug_objects_mem_init(void)
 868 {
 869         if (!debug_objects_enabled)
 870                 return;
 871
 872         obj_cache = kmem_cache_create("debug_objects_cache",
 873                                       sizeof (struct debug_obj), 0,
 874                                       SLAB_DEBUG_OBJECTS, NULL);
 875
 876         if (!obj_cache)
 877                 debug_objects_enabled = 0;
 878         else
 879                 debug_objects_selftest();
 880 }