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