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   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                 printk(KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
 209                        obj_states[obj->state], obj->descr->name);
 210                 WARN_ON(1);
 211         }
 212         debug_objects_warnings++;
 213 }
 214
 215 /*
 216  * Try to repair the damage, so we have a better chance to get useful
 217  * debug output.
 218  */
 219 static void
 220 debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
 221                    void * addr, enum debug_obj_state state)
 222 {
 223         if (fixup)
 224                 debug_objects_fixups += fixup(addr, state);
 225 }
 226
 227 static void debug_object_is_on_stack(void *addr, int onstack)
 228 {
 229         void *stack = current->stack;
 230         int is_on_stack;
 231         static int limit;
 232
 233         if (limit > 4)
 234                 return;
 235
 236         is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE));
 237
 238         if (is_on_stack == onstack)
 239                 return;
 240
 241         limit++;
 242         if (is_on_stack)
 243                 printk(KERN_WARNING
 244                        "ODEBUG: object is on stack, but not annotated\n");
 245         else
 246                 printk(KERN_WARNING
 247                        "ODEBUG: object is not on stack, but annotated\n");
 248         WARN_ON(1);
 249 }
 250
 251 static void
 252 __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
 253 {
 254         enum debug_obj_state state;
 255         struct debug_bucket *db;
 256         struct debug_obj *obj;
 257         unsigned long flags;
 258
 259         fill_pool();
 260
 261         db = get_bucket((unsigned long) addr);
 262
 263         spin_lock_irqsave(&db->lock, flags);
 264
 265         obj = lookup_object(addr, db);
 266         if (!obj) {
 267                 obj = alloc_object(addr, db, descr);
 268                 if (!obj) {
 269                         debug_objects_enabled = 0;
 270                         spin_unlock_irqrestore(&db->lock, flags);
 271                         debug_objects_oom();
 272                         return;
 273                 }
 274                 debug_object_is_on_stack(addr, onstack);
 275         }
 276
 277         switch (obj->state) {
 278         case ODEBUG_STATE_NONE:
 279         case ODEBUG_STATE_INIT:
 280         case ODEBUG_STATE_INACTIVE:
 281                 obj->state = ODEBUG_STATE_INIT;
 282                 break;
 283
 284         case ODEBUG_STATE_ACTIVE:
 285                 debug_print_object(obj, "init");
 286                 state = obj->state;
 287                 spin_unlock_irqrestore(&db->lock, flags);
 288                 debug_object_fixup(descr->fixup_init, addr, state);
 289                 return;
 290
 291         case ODEBUG_STATE_DESTROYED:
 292                 debug_print_object(obj, "init");
 293                 break;
 294         default:
 295                 break;
 296         }
 297
 298         spin_unlock_irqrestore(&db->lock, flags);
 299 }
 300
 301 /**
 302  * debug_object_init - debug checks when an object is initialized
 303  * @addr:       address of the object
 304  * @descr:      pointer to an object specific debug description structure
 305  */
 306 void debug_object_init(void *addr, struct debug_obj_descr *descr)
 307 {
 308         if (!debug_objects_enabled)
 309                 return;
 310
 311         __debug_object_init(addr, descr, 0);
 312 }
 313
 314 /**
 315  * debug_object_init_on_stack - debug checks when an object on stack is
 316  *                              initialized
 317  * @addr:       address of the object
 318  * @descr:      pointer to an object specific debug description structure
 319  */
 320 void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
 321 {
 322         if (!debug_objects_enabled)
 323                 return;
 324
 325         __debug_object_init(addr, descr, 1);
 326 }
 327
 328 /**
 329  * debug_object_activate - debug checks when an object is activated
 330  * @addr:       address of the object
 331  * @descr:      pointer to an object specific debug description structure
 332  */
 333 void debug_object_activate(void *addr, struct debug_obj_descr *descr)
 334 {
 335         enum debug_obj_state state;
 336         struct debug_bucket *db;
 337         struct debug_obj *obj;
 338         unsigned long flags;
 339
 340         if (!debug_objects_enabled)
 341                 return;
 342
 343         db = get_bucket((unsigned long) addr);
 344
 345         spin_lock_irqsave(&db->lock, flags);
 346
 347         obj = lookup_object(addr, db);
 348         if (obj) {
 349                 switch (obj->state) {
 350                 case ODEBUG_STATE_INIT:
 351                 case ODEBUG_STATE_INACTIVE:
 352                         obj->state = ODEBUG_STATE_ACTIVE;
 353                         break;
 354
 355                 case ODEBUG_STATE_ACTIVE:
 356                         debug_print_object(obj, "activate");
 357                         state = obj->state;
 358                         spin_unlock_irqrestore(&db->lock, flags);
 359                         debug_object_fixup(descr->fixup_activate, addr, state);
 360                         return;
 361
 362                 case ODEBUG_STATE_DESTROYED:
 363                         debug_print_object(obj, "activate");
 364                         break;
 365                 default:
 366                         break;
 367                 }
 368                 spin_unlock_irqrestore(&db->lock, flags);
 369                 return;
 370         }
 371
 372         spin_unlock_irqrestore(&db->lock, flags);
 373         /*
 374          * This happens when a static object is activated. We
 375          * let the type specific code decide whether this is
 376          * true or not.
 377          */
 378         debug_object_fixup(descr->fixup_activate, addr,
 379                            ODEBUG_STATE_NOTAVAILABLE);
 380 }
 381
 382 /**
 383  * debug_object_deactivate - debug checks when an object is deactivated
 384  * @addr:       address of the object
 385  * @descr:      pointer to an object specific debug description structure
 386  */
 387 void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
 388 {
 389         struct debug_bucket *db;
 390         struct debug_obj *obj;
 391         unsigned long flags;
 392
 393         if (!debug_objects_enabled)
 394                 return;
 395
 396         db = get_bucket((unsigned long) addr);
 397
 398         spin_lock_irqsave(&db->lock, flags);
 399
 400         obj = lookup_object(addr, db);
 401         if (obj) {
 402                 switch (obj->state) {
 403                 case ODEBUG_STATE_INIT:
 404                 case ODEBUG_STATE_INACTIVE:
 405                 case ODEBUG_STATE_ACTIVE:
 406                         obj->state = ODEBUG_STATE_INACTIVE;
 407                         break;
 408
 409                 case ODEBUG_STATE_DESTROYED:
 410                         debug_print_object(obj, "deactivate");
 411                         break;
 412                 default:
 413                         break;
 414                 }
 415         } else {
 416                 struct debug_obj o = { .object = addr,
 417                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 418                                        .descr = descr };
 419
 420                 debug_print_object(&o, "deactivate");
 421         }
 422
 423         spin_unlock_irqrestore(&db->lock, flags);
 424 }
 425
 426 /**
 427  * debug_object_destroy - debug checks when an object is destroyed
 428  * @addr:       address of the object
 429  * @descr:      pointer to an object specific debug description structure
 430  */
 431 void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
 432 {
 433         enum debug_obj_state state;
 434         struct debug_bucket *db;
 435         struct debug_obj *obj;
 436         unsigned long flags;
 437
 438         if (!debug_objects_enabled)
 439                 return;
 440
 441         db = get_bucket((unsigned long) addr);
 442
 443         spin_lock_irqsave(&db->lock, flags);
 444
 445         obj = lookup_object(addr, db);
 446         if (!obj)
 447                 goto out_unlock;
 448
 449         switch (obj->state) {
 450         case ODEBUG_STATE_NONE:
 451         case ODEBUG_STATE_INIT:
 452         case ODEBUG_STATE_INACTIVE:
 453                 obj->state = ODEBUG_STATE_DESTROYED;
 454                 break;
 455         case ODEBUG_STATE_ACTIVE:
 456                 debug_print_object(obj, "destroy");
 457                 state = obj->state;
 458                 spin_unlock_irqrestore(&db->lock, flags);
 459                 debug_object_fixup(descr->fixup_destroy, addr, state);
 460                 return;
 461
 462         case ODEBUG_STATE_DESTROYED:
 463                 debug_print_object(obj, "destroy");
 464                 break;
 465         default:
 466                 break;
 467         }
 468 out_unlock:
 469         spin_unlock_irqrestore(&db->lock, flags);
 470 }
 471
 472 /**
 473  * debug_object_free - debug checks when an object is freed
 474  * @addr:       address of the object
 475  * @descr:      pointer to an object specific debug description structure
 476  */
 477 void debug_object_free(void *addr, struct debug_obj_descr *descr)
 478 {
 479         enum debug_obj_state state;
 480         struct debug_bucket *db;
 481         struct debug_obj *obj;
 482         unsigned long flags;
 483
 484         if (!debug_objects_enabled)
 485                 return;
 486
 487         db = get_bucket((unsigned long) addr);
 488
 489         spin_lock_irqsave(&db->lock, flags);
 490
 491         obj = lookup_object(addr, db);
 492         if (!obj)
 493                 goto out_unlock;
 494
 495         switch (obj->state) {
 496         case ODEBUG_STATE_ACTIVE:
 497                 debug_print_object(obj, "free");
 498                 state = obj->state;
 499                 spin_unlock_irqrestore(&db->lock, flags);
 500                 debug_object_fixup(descr->fixup_free, addr, state);
 501                 return;
 502         default:
 503                 hlist_del(&obj->node);
 504                 free_object(obj);
 505                 break;
 506         }
 507 out_unlock:
 508         spin_unlock_irqrestore(&db->lock, flags);
 509 }
 510
 511 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 512 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
 513 {
 514         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
 515         struct hlist_node *node, *tmp;
 516         struct debug_obj_descr *descr;
 517         enum debug_obj_state state;
 518         struct debug_bucket *db;
 519         struct debug_obj *obj;
 520         int cnt;
 521
 522         saddr = (unsigned long) address;
 523         eaddr = saddr + size;
 524         paddr = saddr & ODEBUG_CHUNK_MASK;
 525         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
 526         chunks >>= ODEBUG_CHUNK_SHIFT;
 527
 528         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
 529                 db = get_bucket(paddr);
 530
 531 repeat:
 532                 cnt = 0;
 533                 spin_lock_irqsave(&db->lock, flags);
 534                 hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
 535                         cnt++;
 536                         oaddr = (unsigned long) obj->object;
 537                         if (oaddr < saddr || oaddr >= eaddr)
 538                                 continue;
 539
 540                         switch (obj->state) {
 541                         case ODEBUG_STATE_ACTIVE:
 542                                 debug_print_object(obj, "free");
 543                                 descr = obj->descr;
 544                                 state = obj->state;
 545                                 spin_unlock_irqrestore(&db->lock, flags);
 546                                 debug_object_fixup(descr->fixup_free,
 547                                                    (void *) oaddr, state);
 548                                 goto repeat;
 549                         default:
 550                                 hlist_del(&obj->node);
 551                                 free_object(obj);
 552                                 break;
 553                         }
 554                 }
 555                 spin_unlock_irqrestore(&db->lock, flags);
 556                 if (cnt > debug_objects_maxchain)
 557                         debug_objects_maxchain = cnt;
 558         }
 559 }
 560
 561 void debug_check_no_obj_freed(const void *address, unsigned long size)
 562 {
 563         if (debug_objects_enabled)
 564                 __debug_check_no_obj_freed(address, size);
 565 }
 566 #endif
 567
 568 #ifdef CONFIG_DEBUG_FS
 569
 570 static int debug_stats_show(struct seq_file *m, void *v)
 571 {
 572         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
 573         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
 574         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
 575         seq_printf(m, "pool_free     :%d\n", obj_pool_free);
 576         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
 577         seq_printf(m, "pool_used     :%d\n", obj_pool_used);
 578         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
 579         return 0;
 580 }
 581
 582 static int debug_stats_open(struct inode *inode, struct file *filp)
 583 {
 584         return single_open(filp, debug_stats_show, NULL);
 585 }
 586
 587 static const struct file_operations debug_stats_fops = {
 588         .open           = debug_stats_open,
 589         .read           = seq_read,
 590         .llseek         = seq_lseek,
 591         .release        = single_release,
 592 };
 593
 594 static int __init debug_objects_init_debugfs(void)
 595 {
 596         struct dentry *dbgdir, *dbgstats;
 597
 598         if (!debug_objects_enabled)
 599                 return 0;
 600
 601         dbgdir = debugfs_create_dir("debug_objects", NULL);
 602         if (!dbgdir)
 603                 return -ENOMEM;
 604
 605         dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
 606                                        &debug_stats_fops);
 607         if (!dbgstats)
 608                 goto err;
 609
 610         return 0;
 611
 612 err:
 613         debugfs_remove(dbgdir);
 614
 615         return -ENOMEM;
 616 }
 617 __initcall(debug_objects_init_debugfs);
 618
 619 #else
 620 static inline void debug_objects_init_debugfs(void) { }
 621 #endif
 622
 623 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
 624
 625 /* Random data structure for the self test */
 626 struct self_test {
 627         unsigned long   dummy1[6];
 628         int             static_init;
 629         unsigned long   dummy2[3];
 630 };
 631
 632 static __initdata struct debug_obj_descr descr_type_test;
 633
 634 /*
 635  * fixup_init is called when:
 636  * - an active object is initialized
 637  */
 638 static int __init fixup_init(void *addr, enum debug_obj_state state)
 639 {
 640         struct self_test *obj = addr;
 641
 642         switch (state) {
 643         case ODEBUG_STATE_ACTIVE:
 644                 debug_object_deactivate(obj, &descr_type_test);
 645                 debug_object_init(obj, &descr_type_test);
 646                 return 1;
 647         default:
 648                 return 0;
 649         }
 650 }
 651
 652 /*
 653  * fixup_activate is called when:
 654  * - an active object is activated
 655  * - an unknown object is activated (might be a statically initialized object)
 656  */
 657 static int __init fixup_activate(void *addr, enum debug_obj_state state)
 658 {
 659         struct self_test *obj = addr;
 660
 661         switch (state) {
 662         case ODEBUG_STATE_NOTAVAILABLE:
 663                 if (obj->static_init == 1) {
 664                         debug_object_init(obj, &descr_type_test);
 665                         debug_object_activate(obj, &descr_type_test);
 666                         /*
 667                          * Real code should return 0 here ! This is
 668                          * not a fixup of some bad behaviour. We
 669                          * merily call the debug_init function to keep
 670                          * track of the object.
 671                          */
 672                         return 1;
 673                 } else {
 674                         /* Real code needs to emit a warning here */
 675                 }
 676                 return 0;
 677
 678         case ODEBUG_STATE_ACTIVE:
 679                 debug_object_deactivate(obj, &descr_type_test);
 680                 debug_object_activate(obj, &descr_type_test);
 681                 return 1;
 682
 683         default:
 684                 return 0;
 685         }
 686 }
 687
 688 /*
 689  * fixup_destroy is called when:
 690  * - an active object is destroyed
 691  */
 692 static int __init fixup_destroy(void *addr, enum debug_obj_state state)
 693 {
 694         struct self_test *obj = addr;
 695
 696         switch (state) {
 697         case ODEBUG_STATE_ACTIVE:
 698                 debug_object_deactivate(obj, &descr_type_test);
 699                 debug_object_destroy(obj, &descr_type_test);
 700                 return 1;
 701         default:
 702                 return 0;
 703         }
 704 }
 705
 706 /*
 707  * fixup_free is called when:
 708  * - an active object is freed
 709  */
 710 static int __init fixup_free(void *addr, enum debug_obj_state state)
 711 {
 712         struct self_test *obj = addr;
 713
 714         switch (state) {
 715         case ODEBUG_STATE_ACTIVE:
 716                 debug_object_deactivate(obj, &descr_type_test);
 717                 debug_object_free(obj, &descr_type_test);
 718                 return 1;
 719         default:
 720                 return 0;
 721         }
 722 }
 723
 724 static int
 725 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
 726 {
 727         struct debug_bucket *db;
 728         struct debug_obj *obj;
 729         unsigned long flags;
 730         int res = -EINVAL;
 731
 732         db = get_bucket((unsigned long) addr);
 733
 734         spin_lock_irqsave(&db->lock, flags);
 735
 736         obj = lookup_object(addr, db);
 737         if (!obj && state != ODEBUG_STATE_NONE) {
 738                 printk(KERN_ERR "ODEBUG: selftest object not found\n");
 739                 WARN_ON(1);
 740                 goto out;
 741         }
 742         if (obj && obj->state != state) {
 743                 printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
 744                        obj->state, state);
 745                 WARN_ON(1);
 746                 goto out;
 747         }
 748         if (fixups != debug_objects_fixups) {
 749                 printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
 750                        fixups, debug_objects_fixups);
 751                 WARN_ON(1);
 752                 goto out;
 753         }
 754         if (warnings != debug_objects_warnings) {
 755                 printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
 756                        warnings, debug_objects_warnings);
 757                 WARN_ON(1);
 758                 goto out;
 759         }
 760         res = 0;
 761 out:
 762         spin_unlock_irqrestore(&db->lock, flags);
 763         if (res)
 764                 debug_objects_enabled = 0;
 765         return res;
 766 }
 767
 768 static __initdata struct debug_obj_descr descr_type_test = {
 769         .name                   = "selftest",
 770         .fixup_init             = fixup_init,
 771         .fixup_activate         = fixup_activate,
 772         .fixup_destroy          = fixup_destroy,
 773         .fixup_free             = fixup_free,
 774 };
 775
 776 static __initdata struct self_test obj = { .static_init = 0 };
 777
 778 static void __init debug_objects_selftest(void)
 779 {
 780         int fixups, oldfixups, warnings, oldwarnings;
 781         unsigned long flags;
 782
 783         local_irq_save(flags);
 784
 785         fixups = oldfixups = debug_objects_fixups;
 786         warnings = oldwarnings = debug_objects_warnings;
 787         descr_test = &descr_type_test;
 788
 789         debug_object_init(&obj, &descr_type_test);
 790         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
 791                 goto out;
 792         debug_object_activate(&obj, &descr_type_test);
 793         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
 794                 goto out;
 795         debug_object_activate(&obj, &descr_type_test);
 796         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
 797                 goto out;
 798         debug_object_deactivate(&obj, &descr_type_test);
 799         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
 800                 goto out;
 801         debug_object_destroy(&obj, &descr_type_test);
 802         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
 803                 goto out;
 804         debug_object_init(&obj, &descr_type_test);
 805         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
 806                 goto out;
 807         debug_object_activate(&obj, &descr_type_test);
 808         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
 809                 goto out;
 810         debug_object_deactivate(&obj, &descr_type_test);
 811         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
 812                 goto out;
 813         debug_object_free(&obj, &descr_type_test);
 814         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
 815                 goto out;
 816
 817         obj.static_init = 1;
 818         debug_object_activate(&obj, &descr_type_test);
 819         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
 820                 goto out;
 821         debug_object_init(&obj, &descr_type_test);
 822         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
 823                 goto out;
 824         debug_object_free(&obj, &descr_type_test);
 825         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
 826                 goto out;
 827
 828 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 829         debug_object_init(&obj, &descr_type_test);
 830         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
 831                 goto out;
 832         debug_object_activate(&obj, &descr_type_test);
 833         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
 834                 goto out;
 835         __debug_check_no_obj_freed(&obj, sizeof(obj));
 836         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
 837                 goto out;
 838 #endif
 839         printk(KERN_INFO "ODEBUG: selftest passed\n");
 840
 841 out:
 842         debug_objects_fixups = oldfixups;
 843         debug_objects_warnings = oldwarnings;
 844         descr_test = NULL;
 845
 846         local_irq_restore(flags);
 847 }
 848 #else
 849 static inline void debug_objects_selftest(void) { }
 850 #endif
 851
 852 /*
 853  * Called during early boot to initialize the hash buckets and link
 854  * the static object pool objects into the poll list. After this call
 855  * the object tracker is fully operational.
 856  */
 857 void __init debug_objects_early_init(void)
 858 {
 859         int i;
 860
 861         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
 862                 spin_lock_init(&obj_hash[i].lock);
 863
 864         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
 865                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
 866 }
 867
 868 /*
 869  * Called after the kmem_caches are functional to setup a dedicated
 870  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
 871  * prevents that the debug code is called on kmem_cache_free() for the
 872  * debug tracker objects to avoid recursive calls.
 873  */
 874 void __init debug_objects_mem_init(void)
 875 {
 876         if (!debug_objects_enabled)
 877                 return;
 878
 879         obj_cache = kmem_cache_create("debug_objects_cache",
 880                                       sizeof (struct debug_obj), 0,
 881                                       SLAB_DEBUG_OBJECTS, NULL);
 882
 883         if (!obj_cache)
 884                 debug_objects_enabled = 0;
 885         else
 886                 debug_objects_selftest();
 887 }