lib/debugobjects.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Generic infrastructure for lifetime debugging of objects.
   4  *
   5  * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de>
   6  */
   7
   8 #define pr_fmt(fmt) "ODEBUG: " fmt
   9
  10 #include <linux/debugobjects.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/sched.h>
  13 #include <linux/sched/task_stack.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/debugfs.h>
  16 #include <linux/slab.h>
  17 #include <linux/hash.h>
  18 #include <linux/kmemleak.h>
  19 #include <linux/cpu.h>
  20
  21 #define ODEBUG_HASH_BITS        14
  22 #define ODEBUG_HASH_SIZE        (1 << ODEBUG_HASH_BITS)
  23
  24 #define ODEBUG_POOL_SIZE        1024
  25 #define ODEBUG_POOL_MIN_LEVEL   256
  26 #define ODEBUG_POOL_PERCPU_SIZE 64
  27 #define ODEBUG_BATCH_SIZE       16
  28
  29 #define ODEBUG_CHUNK_SHIFT      PAGE_SHIFT
  30 #define ODEBUG_CHUNK_SIZE       (1 << ODEBUG_CHUNK_SHIFT)
  31 #define ODEBUG_CHUNK_MASK       (~(ODEBUG_CHUNK_SIZE - 1))
  32
  33 /*
  34  * We limit the freeing of debug objects via workqueue at a maximum
  35  * frequency of 10Hz and about 1024 objects for each freeing operation.
  36  * So it is freeing at most 10k debug objects per second.
  37  */
  38 #define ODEBUG_FREE_WORK_MAX    1024
  39 #define ODEBUG_FREE_WORK_DELAY  DIV_ROUND_UP(HZ, 10)
  40
  41 struct debug_bucket {
  42         struct hlist_head       list;
  43         raw_spinlock_t          lock;
  44 };
  45
  46 /*
  47  * Debug object percpu free list
  48  * Access is protected by disabling irq
  49  */
  50 struct debug_percpu_free {
  51         struct hlist_head       free_objs;
  52         int                     obj_free;
  53 };
  54
  55 static DEFINE_PER_CPU(struct debug_percpu_free, percpu_obj_pool);
  56
  57 static struct debug_bucket      obj_hash[ODEBUG_HASH_SIZE];
  58
  59 static struct debug_obj         obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
  60
  61 static DEFINE_RAW_SPINLOCK(pool_lock);
  62
  63 static HLIST_HEAD(obj_pool);
  64 static HLIST_HEAD(obj_to_free);
  65
  66 /*
  67  * Because of the presence of percpu free pools, obj_pool_free will
  68  * under-count those in the percpu free pools. Similarly, obj_pool_used
  69  * will over-count those in the percpu free pools. Adjustments will be
  70  * made at debug_stats_show(). Both obj_pool_min_free and obj_pool_max_used
  71  * can be off.
  72  */
  73 static int                      obj_pool_min_free = ODEBUG_POOL_SIZE;
  74 static int                      obj_pool_free = ODEBUG_POOL_SIZE;
  75 static int                      obj_pool_used;
  76 static int                      obj_pool_max_used;
  77 static bool                     obj_freeing;
  78 /* The number of objs on the global free list */
  79 static int                      obj_nr_tofree;
  80
  81 static int                      debug_objects_maxchain __read_mostly;
  82 static int __maybe_unused       debug_objects_maxchecked __read_mostly;
  83 static int                      debug_objects_fixups __read_mostly;
  84 static int                      debug_objects_warnings __read_mostly;
  85 static int                      debug_objects_enabled __read_mostly
  86                                 = CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
  87 static int                      debug_objects_pool_size __read_mostly
  88                                 = ODEBUG_POOL_SIZE;
  89 static int                      debug_objects_pool_min_level __read_mostly
  90                                 = ODEBUG_POOL_MIN_LEVEL;
  91 static const struct debug_obj_descr *descr_test  __read_mostly;
  92 static struct kmem_cache        *obj_cache __read_mostly;
  93
  94 /*
  95  * Track numbers of kmem_cache_alloc()/free() calls done.
  96  */
  97 static int                      debug_objects_allocated;
  98 static int                      debug_objects_freed;
  99
 100 static void free_obj_work(struct work_struct *work);
 101 static DECLARE_DELAYED_WORK(debug_obj_work, free_obj_work);
 102
 103 static int __init enable_object_debug(char *str)
 104 {
 105         debug_objects_enabled = 1;
 106         return 0;
 107 }
 108
 109 static int __init disable_object_debug(char *str)
 110 {
 111         debug_objects_enabled = 0;
 112         return 0;
 113 }
 114
 115 early_param("debug_objects", enable_object_debug);
 116 early_param("no_debug_objects", disable_object_debug);
 117
 118 static const char *obj_states[ODEBUG_STATE_MAX] = {
 119         [ODEBUG_STATE_NONE]             = "none",
 120         [ODEBUG_STATE_INIT]             = "initialized",
 121         [ODEBUG_STATE_INACTIVE]         = "inactive",
 122         [ODEBUG_STATE_ACTIVE]           = "active",
 123         [ODEBUG_STATE_DESTROYED]        = "destroyed",
 124         [ODEBUG_STATE_NOTAVAILABLE]     = "not available",
 125 };
 126
 127 static void fill_pool(void)
 128 {
 129         gfp_t gfp = __GFP_HIGH | __GFP_NOWARN;
 130         struct debug_obj *obj;
 131         unsigned long flags;
 132
 133         if (likely(READ_ONCE(obj_pool_free) >= debug_objects_pool_min_level))
 134                 return;
 135
 136         /*
 137          * Reuse objs from the global free list; they will be reinitialized
 138          * when allocating.
 139          *
 140          * Both obj_nr_tofree and obj_pool_free are checked locklessly; the
 141          * READ_ONCE()s pair with the WRITE_ONCE()s in pool_lock critical
 142          * sections.
 143          */
 144         while (READ_ONCE(obj_nr_tofree) && (READ_ONCE(obj_pool_free) < obj_pool_min_free)) {
 145                 raw_spin_lock_irqsave(&pool_lock, flags);
 146                 /*
 147                  * Recheck with the lock held as the worker thread might have
 148                  * won the race and freed the global free list already.
 149                  */
 150                 while (obj_nr_tofree && (obj_pool_free < obj_pool_min_free)) {
 151                         obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
 152                         hlist_del(&obj->node);
 153                         WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
 154                         hlist_add_head(&obj->node, &obj_pool);
 155                         WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
 156                 }
 157                 raw_spin_unlock_irqrestore(&pool_lock, flags);
 158         }
 159
 160         if (unlikely(!obj_cache))
 161                 return;
 162
 163         while (READ_ONCE(obj_pool_free) < debug_objects_pool_min_level) {
 164                 struct debug_obj *new[ODEBUG_BATCH_SIZE];
 165                 int cnt;
 166
 167                 for (cnt = 0; cnt < ODEBUG_BATCH_SIZE; cnt++) {
 168                         new[cnt] = kmem_cache_zalloc(obj_cache, gfp);
 169                         if (!new[cnt])
 170                                 break;
 171                 }
 172                 if (!cnt)
 173                         return;
 174
 175                 raw_spin_lock_irqsave(&pool_lock, flags);
 176                 while (cnt) {
 177                         hlist_add_head(&new[--cnt]->node, &obj_pool);
 178                         debug_objects_allocated++;
 179                         WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
 180                 }
 181                 raw_spin_unlock_irqrestore(&pool_lock, flags);
 182         }
 183 }
 184
 185 /*
 186  * Lookup an object in the hash bucket.
 187  */
 188 static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
 189 {
 190         struct debug_obj *obj;
 191         int cnt = 0;
 192
 193         hlist_for_each_entry(obj, &b->list, node) {
 194                 cnt++;
 195                 if (obj->object == addr)
 196                         return obj;
 197         }
 198         if (cnt > debug_objects_maxchain)
 199                 debug_objects_maxchain = cnt;
 200
 201         return NULL;
 202 }
 203
 204 /*
 205  * Allocate a new object from the hlist
 206  */
 207 static struct debug_obj *__alloc_object(struct hlist_head *list)
 208 {
 209         struct debug_obj *obj = NULL;
 210
 211         if (list->first) {
 212                 obj = hlist_entry(list->first, typeof(*obj), node);
 213                 hlist_del(&obj->node);
 214         }
 215
 216         return obj;
 217 }
 218
 219 static struct debug_obj *
 220 alloc_object(void *addr, struct debug_bucket *b, const struct debug_obj_descr *descr)
 221 {
 222         struct debug_percpu_free *percpu_pool = this_cpu_ptr(&percpu_obj_pool);
 223         struct debug_obj *obj;
 224
 225         if (likely(obj_cache)) {
 226                 obj = __alloc_object(&percpu_pool->free_objs);
 227                 if (obj) {
 228                         percpu_pool->obj_free--;
 229                         goto init_obj;
 230                 }
 231         }
 232
 233         raw_spin_lock(&pool_lock);
 234         obj = __alloc_object(&obj_pool);
 235         if (obj) {
 236                 obj_pool_used++;
 237                 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
 238
 239                 /*
 240                  * Looking ahead, allocate one batch of debug objects and
 241                  * put them into the percpu free pool.
 242                  */
 243                 if (likely(obj_cache)) {
 244                         int i;
 245
 246                         for (i = 0; i < ODEBUG_BATCH_SIZE; i++) {
 247                                 struct debug_obj *obj2;
 248
 249                                 obj2 = __alloc_object(&obj_pool);
 250                                 if (!obj2)
 251                                         break;
 252                                 hlist_add_head(&obj2->node,
 253                                                &percpu_pool->free_objs);
 254                                 percpu_pool->obj_free++;
 255                                 obj_pool_used++;
 256                                 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
 257                         }
 258                 }
 259
 260                 if (obj_pool_used > obj_pool_max_used)
 261                         obj_pool_max_used = obj_pool_used;
 262
 263                 if (obj_pool_free < obj_pool_min_free)
 264                         obj_pool_min_free = obj_pool_free;
 265         }
 266         raw_spin_unlock(&pool_lock);
 267
 268 init_obj:
 269         if (obj) {
 270                 obj->object = addr;
 271                 obj->descr  = descr;
 272                 obj->state  = ODEBUG_STATE_NONE;
 273                 obj->astate = 0;
 274                 hlist_add_head(&obj->node, &b->list);
 275         }
 276         return obj;
 277 }
 278
 279 /*
 280  * workqueue function to free objects.
 281  *
 282  * To reduce contention on the global pool_lock, the actual freeing of
 283  * debug objects will be delayed if the pool_lock is busy.
 284  */
 285 static void free_obj_work(struct work_struct *work)
 286 {
 287         struct hlist_node *tmp;
 288         struct debug_obj *obj;
 289         unsigned long flags;
 290         HLIST_HEAD(tofree);
 291
 292         WRITE_ONCE(obj_freeing, false);
 293         if (!raw_spin_trylock_irqsave(&pool_lock, flags))
 294                 return;
 295
 296         if (obj_pool_free >= debug_objects_pool_size)
 297                 goto free_objs;
 298
 299         /*
 300          * The objs on the pool list might be allocated before the work is
 301          * run, so recheck if pool list it full or not, if not fill pool
 302          * list from the global free list. As it is likely that a workload
 303          * may be gearing up to use more and more objects, don't free any
 304          * of them until the next round.
 305          */
 306         while (obj_nr_tofree && obj_pool_free < debug_objects_pool_size) {
 307                 obj = hlist_entry(obj_to_free.first, typeof(*obj), node);
 308                 hlist_del(&obj->node);
 309                 hlist_add_head(&obj->node, &obj_pool);
 310                 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
 311                 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree - 1);
 312         }
 313         raw_spin_unlock_irqrestore(&pool_lock, flags);
 314         return;
 315
 316 free_objs:
 317         /*
 318          * Pool list is already full and there are still objs on the free
 319          * list. Move remaining free objs to a temporary list to free the
 320          * memory outside the pool_lock held region.
 321          */
 322         if (obj_nr_tofree) {
 323                 hlist_move_list(&obj_to_free, &tofree);
 324                 debug_objects_freed += obj_nr_tofree;
 325                 WRITE_ONCE(obj_nr_tofree, 0);
 326         }
 327         raw_spin_unlock_irqrestore(&pool_lock, flags);
 328
 329         hlist_for_each_entry_safe(obj, tmp, &tofree, node) {
 330                 hlist_del(&obj->node);
 331                 kmem_cache_free(obj_cache, obj);
 332         }
 333 }
 334
 335 static void __free_object(struct debug_obj *obj)
 336 {
 337         struct debug_obj *objs[ODEBUG_BATCH_SIZE];
 338         struct debug_percpu_free *percpu_pool;
 339         int lookahead_count = 0;
 340         unsigned long flags;
 341         bool work;
 342
 343         local_irq_save(flags);
 344         if (!obj_cache)
 345                 goto free_to_obj_pool;
 346
 347         /*
 348          * Try to free it into the percpu pool first.
 349          */
 350         percpu_pool = this_cpu_ptr(&percpu_obj_pool);
 351         if (percpu_pool->obj_free < ODEBUG_POOL_PERCPU_SIZE) {
 352                 hlist_add_head(&obj->node, &percpu_pool->free_objs);
 353                 percpu_pool->obj_free++;
 354                 local_irq_restore(flags);
 355                 return;
 356         }
 357
 358         /*
 359          * As the percpu pool is full, look ahead and pull out a batch
 360          * of objects from the percpu pool and free them as well.
 361          */
 362         for (; lookahead_count < ODEBUG_BATCH_SIZE; lookahead_count++) {
 363                 objs[lookahead_count] = __alloc_object(&percpu_pool->free_objs);
 364                 if (!objs[lookahead_count])
 365                         break;
 366                 percpu_pool->obj_free--;
 367         }
 368
 369 free_to_obj_pool:
 370         raw_spin_lock(&pool_lock);
 371         work = (obj_pool_free > debug_objects_pool_size) && obj_cache &&
 372                (obj_nr_tofree < ODEBUG_FREE_WORK_MAX);
 373         obj_pool_used--;
 374
 375         if (work) {
 376                 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
 377                 hlist_add_head(&obj->node, &obj_to_free);
 378                 if (lookahead_count) {
 379                         WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + lookahead_count);
 380                         obj_pool_used -= lookahead_count;
 381                         while (lookahead_count) {
 382                                 hlist_add_head(&objs[--lookahead_count]->node,
 383                                                &obj_to_free);
 384                         }
 385                 }
 386
 387                 if ((obj_pool_free > debug_objects_pool_size) &&
 388                     (obj_nr_tofree < ODEBUG_FREE_WORK_MAX)) {
 389                         int i;
 390
 391                         /*
 392                          * Free one more batch of objects from obj_pool.
 393                          */
 394                         for (i = 0; i < ODEBUG_BATCH_SIZE; i++) {
 395                                 obj = __alloc_object(&obj_pool);
 396                                 hlist_add_head(&obj->node, &obj_to_free);
 397                                 WRITE_ONCE(obj_pool_free, obj_pool_free - 1);
 398                                 WRITE_ONCE(obj_nr_tofree, obj_nr_tofree + 1);
 399                         }
 400                 }
 401         } else {
 402                 WRITE_ONCE(obj_pool_free, obj_pool_free + 1);
 403                 hlist_add_head(&obj->node, &obj_pool);
 404                 if (lookahead_count) {
 405                         WRITE_ONCE(obj_pool_free, obj_pool_free + lookahead_count);
 406                         obj_pool_used -= lookahead_count;
 407                         while (lookahead_count) {
 408                                 hlist_add_head(&objs[--lookahead_count]->node,
 409                                                &obj_pool);
 410                         }
 411                 }
 412         }
 413         raw_spin_unlock(&pool_lock);
 414         local_irq_restore(flags);
 415 }
 416
 417 /*
 418  * Put the object back into the pool and schedule work to free objects
 419  * if necessary.
 420  */
 421 static void free_object(struct debug_obj *obj)
 422 {
 423         __free_object(obj);
 424         if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
 425                 WRITE_ONCE(obj_freeing, true);
 426                 schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
 427         }
 428 }
 429
 430 #ifdef CONFIG_HOTPLUG_CPU
 431 static int object_cpu_offline(unsigned int cpu)
 432 {
 433         struct debug_percpu_free *percpu_pool;
 434         struct hlist_node *tmp;
 435         struct debug_obj *obj;
 436         unsigned long flags;
 437
 438         /* Remote access is safe as the CPU is dead already */
 439         percpu_pool = per_cpu_ptr(&percpu_obj_pool, cpu);
 440         hlist_for_each_entry_safe(obj, tmp, &percpu_pool->free_objs, node) {
 441                 hlist_del(&obj->node);
 442                 kmem_cache_free(obj_cache, obj);
 443         }
 444
 445         raw_spin_lock_irqsave(&pool_lock, flags);
 446         obj_pool_used -= percpu_pool->obj_free;
 447         debug_objects_freed += percpu_pool->obj_free;
 448         raw_spin_unlock_irqrestore(&pool_lock, flags);
 449
 450         percpu_pool->obj_free = 0;
 451
 452         return 0;
 453 }
 454 #endif
 455
 456 /*
 457  * We run out of memory. That means we probably have tons of objects
 458  * allocated.
 459  */
 460 static void debug_objects_oom(void)
 461 {
 462         struct debug_bucket *db = obj_hash;
 463         struct hlist_node *tmp;
 464         HLIST_HEAD(freelist);
 465         struct debug_obj *obj;
 466         unsigned long flags;
 467         int i;
 468
 469         pr_warn("Out of memory. ODEBUG disabled\n");
 470
 471         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
 472                 raw_spin_lock_irqsave(&db->lock, flags);
 473                 hlist_move_list(&db->list, &freelist);
 474                 raw_spin_unlock_irqrestore(&db->lock, flags);
 475
 476                 /* Now free them */
 477                 hlist_for_each_entry_safe(obj, tmp, &freelist, node) {
 478                         hlist_del(&obj->node);
 479                         free_object(obj);
 480                 }
 481         }
 482 }
 483
 484 /*
 485  * We use the pfn of the address for the hash. That way we can check
 486  * for freed objects simply by checking the affected bucket.
 487  */
 488 static struct debug_bucket *get_bucket(unsigned long addr)
 489 {
 490         unsigned long hash;
 491
 492         hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
 493         return &obj_hash[hash];
 494 }
 495
 496 static void debug_print_object(struct debug_obj *obj, char *msg)
 497 {
 498         const struct debug_obj_descr *descr = obj->descr;
 499         static int limit;
 500
 501         /*
 502          * Don't report if lookup_object_or_alloc() by the current thread
 503          * failed because lookup_object_or_alloc()/debug_objects_oom() by a
 504          * concurrent thread turned off debug_objects_enabled and cleared
 505          * the hash buckets.
 506          */
 507         if (!debug_objects_enabled)
 508                 return;
 509
 510         if (limit < 5 && descr != descr_test) {
 511                 void *hint = descr->debug_hint ?
 512                         descr->debug_hint(obj->object) : NULL;
 513                 limit++;
 514                 WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
 515                                  "object: %p object type: %s hint: %pS\n",
 516                         msg, obj_states[obj->state], obj->astate,
 517                         obj->object, descr->name, hint);
 518         }
 519         debug_objects_warnings++;
 520 }
 521
 522 /*
 523  * Try to repair the damage, so we have a better chance to get useful
 524  * debug output.
 525  */
 526 static bool
 527 debug_object_fixup(bool (*fixup)(void *addr, enum debug_obj_state state),
 528                    void * addr, enum debug_obj_state state)
 529 {
 530         if (fixup && fixup(addr, state)) {
 531                 debug_objects_fixups++;
 532                 return true;
 533         }
 534         return false;
 535 }
 536
 537 static void debug_object_is_on_stack(void *addr, int onstack)
 538 {
 539         int is_on_stack;
 540         static int limit;
 541
 542         if (limit > 4)
 543                 return;
 544
 545         is_on_stack = object_is_on_stack(addr);
 546         if (is_on_stack == onstack)
 547                 return;
 548
 549         limit++;
 550         if (is_on_stack)
 551                 pr_warn("object %p is on stack %p, but NOT annotated.\n", addr,
 552                          task_stack_page(current));
 553         else
 554                 pr_warn("object %p is NOT on stack %p, but annotated.\n", addr,
 555                          task_stack_page(current));
 556
 557         WARN_ON(1);
 558 }
 559
 560 static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket *b,
 561                                                 const struct debug_obj_descr *descr,
 562                                                 bool onstack, bool alloc_ifstatic)
 563 {
 564         struct debug_obj *obj = lookup_object(addr, b);
 565         enum debug_obj_state state = ODEBUG_STATE_NONE;
 566
 567         if (likely(obj))
 568                 return obj;
 569
 570         /*
 571          * debug_object_init() unconditionally allocates untracked
 572          * objects. It does not matter whether it is a static object or
 573          * not.
 574          *
 575          * debug_object_assert_init() and debug_object_activate() allow
 576          * allocation only if the descriptor callback confirms that the
 577          * object is static and considered initialized. For non-static
 578          * objects the allocation needs to be done from the fixup callback.
 579          */
 580         if (unlikely(alloc_ifstatic)) {
 581                 if (!descr->is_static_object || !descr->is_static_object(addr))
 582                         return ERR_PTR(-ENOENT);
 583                 /* Statically allocated objects are considered initialized */
 584                 state = ODEBUG_STATE_INIT;
 585         }
 586
 587         obj = alloc_object(addr, b, descr);
 588         if (likely(obj)) {
 589                 obj->state = state;
 590                 debug_object_is_on_stack(addr, onstack);
 591                 return obj;
 592         }
 593
 594         /* Out of memory. Do the cleanup outside of the locked region */
 595         debug_objects_enabled = 0;
 596         return NULL;
 597 }
 598
 599 static void debug_objects_fill_pool(void)
 600 {
 601         /*
 602          * On RT enabled kernels the pool refill must happen in preemptible
 603          * context -- for !RT kernels we rely on the fact that spinlock_t and
 604          * raw_spinlock_t are basically the same type and this lock-type
 605          * inversion works just fine.
 606          */
 607         if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) {
 608                 /*
 609                  * Annotate away the spinlock_t inside raw_spinlock_t warning
 610                  * by temporarily raising the wait-type to WAIT_SLEEP, matching
 611                  * the preemptible() condition above.
 612                  */
 613                 static DEFINE_WAIT_OVERRIDE_MAP(fill_pool_map, LD_WAIT_SLEEP);
 614                 lock_map_acquire_try(&fill_pool_map);
 615                 fill_pool();
 616                 lock_map_release(&fill_pool_map);
 617         }
 618 }
 619
 620 static void
 621 __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack)
 622 {
 623         enum debug_obj_state state;
 624         struct debug_bucket *db;
 625         struct debug_obj *obj;
 626         unsigned long flags;
 627
 628         debug_objects_fill_pool();
 629
 630         db = get_bucket((unsigned long) addr);
 631
 632         raw_spin_lock_irqsave(&db->lock, flags);
 633
 634         obj = lookup_object_or_alloc(addr, db, descr, onstack, false);
 635         if (unlikely(!obj)) {
 636                 raw_spin_unlock_irqrestore(&db->lock, flags);
 637                 debug_objects_oom();
 638                 return;
 639         }
 640
 641         switch (obj->state) {
 642         case ODEBUG_STATE_NONE:
 643         case ODEBUG_STATE_INIT:
 644         case ODEBUG_STATE_INACTIVE:
 645                 obj->state = ODEBUG_STATE_INIT;
 646                 break;
 647
 648         case ODEBUG_STATE_ACTIVE:
 649                 state = obj->state;
 650                 raw_spin_unlock_irqrestore(&db->lock, flags);
 651                 debug_print_object(obj, "init");
 652                 debug_object_fixup(descr->fixup_init, addr, state);
 653                 return;
 654
 655         case ODEBUG_STATE_DESTROYED:
 656                 raw_spin_unlock_irqrestore(&db->lock, flags);
 657                 debug_print_object(obj, "init");
 658                 return;
 659         default:
 660                 break;
 661         }
 662
 663         raw_spin_unlock_irqrestore(&db->lock, flags);
 664 }
 665
 666 /**
 667  * debug_object_init - debug checks when an object is initialized
 668  * @addr:       address of the object
 669  * @descr:      pointer to an object specific debug description structure
 670  */
 671 void debug_object_init(void *addr, const struct debug_obj_descr *descr)
 672 {
 673         if (!debug_objects_enabled)
 674                 return;
 675
 676         __debug_object_init(addr, descr, 0);
 677 }
 678 EXPORT_SYMBOL_GPL(debug_object_init);
 679
 680 /**
 681  * debug_object_init_on_stack - debug checks when an object on stack is
 682  *                              initialized
 683  * @addr:       address of the object
 684  * @descr:      pointer to an object specific debug description structure
 685  */
 686 void debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr)
 687 {
 688         if (!debug_objects_enabled)
 689                 return;
 690
 691         __debug_object_init(addr, descr, 1);
 692 }
 693 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
 694
 695 /**
 696  * debug_object_activate - debug checks when an object is activated
 697  * @addr:       address of the object
 698  * @descr:      pointer to an object specific debug description structure
 699  * Returns 0 for success, -EINVAL for check failed.
 700  */
 701 int debug_object_activate(void *addr, const struct debug_obj_descr *descr)
 702 {
 703         struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
 704         enum debug_obj_state state;
 705         struct debug_bucket *db;
 706         struct debug_obj *obj;
 707         unsigned long flags;
 708         int ret;
 709
 710         if (!debug_objects_enabled)
 711                 return 0;
 712
 713         debug_objects_fill_pool();
 714
 715         db = get_bucket((unsigned long) addr);
 716
 717         raw_spin_lock_irqsave(&db->lock, flags);
 718
 719         obj = lookup_object_or_alloc(addr, db, descr, false, true);
 720         if (likely(!IS_ERR_OR_NULL(obj))) {
 721                 bool print_object = false;
 722
 723                 switch (obj->state) {
 724                 case ODEBUG_STATE_INIT:
 725                 case ODEBUG_STATE_INACTIVE:
 726                         obj->state = ODEBUG_STATE_ACTIVE;
 727                         ret = 0;
 728                         break;
 729
 730                 case ODEBUG_STATE_ACTIVE:
 731                         state = obj->state;
 732                         raw_spin_unlock_irqrestore(&db->lock, flags);
 733                         debug_print_object(obj, "activate");
 734                         ret = debug_object_fixup(descr->fixup_activate, addr, state);
 735                         return ret ? 0 : -EINVAL;
 736
 737                 case ODEBUG_STATE_DESTROYED:
 738                         print_object = true;
 739                         ret = -EINVAL;
 740                         break;
 741                 default:
 742                         ret = 0;
 743                         break;
 744                 }
 745                 raw_spin_unlock_irqrestore(&db->lock, flags);
 746                 if (print_object)
 747                         debug_print_object(obj, "activate");
 748                 return ret;
 749         }
 750
 751         raw_spin_unlock_irqrestore(&db->lock, flags);
 752
 753         /* If NULL the allocation has hit OOM */
 754         if (!obj) {
 755                 debug_objects_oom();
 756                 return 0;
 757         }
 758
 759         /* Object is neither static nor tracked. It's not initialized */
 760         debug_print_object(&o, "activate");
 761         ret = debug_object_fixup(descr->fixup_activate, addr, ODEBUG_STATE_NOTAVAILABLE);
 762         return ret ? 0 : -EINVAL;
 763 }
 764 EXPORT_SYMBOL_GPL(debug_object_activate);
 765
 766 /**
 767  * debug_object_deactivate - debug checks when an object is deactivated
 768  * @addr:       address of the object
 769  * @descr:      pointer to an object specific debug description structure
 770  */
 771 void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr)
 772 {
 773         struct debug_bucket *db;
 774         struct debug_obj *obj;
 775         unsigned long flags;
 776         bool print_object = false;
 777
 778         if (!debug_objects_enabled)
 779                 return;
 780
 781         db = get_bucket((unsigned long) addr);
 782
 783         raw_spin_lock_irqsave(&db->lock, flags);
 784
 785         obj = lookup_object(addr, db);
 786         if (obj) {
 787                 switch (obj->state) {
 788                 case ODEBUG_STATE_INIT:
 789                 case ODEBUG_STATE_INACTIVE:
 790                 case ODEBUG_STATE_ACTIVE:
 791                         if (!obj->astate)
 792                                 obj->state = ODEBUG_STATE_INACTIVE;
 793                         else
 794                                 print_object = true;
 795                         break;
 796
 797                 case ODEBUG_STATE_DESTROYED:
 798                         print_object = true;
 799                         break;
 800                 default:
 801                         break;
 802                 }
 803         }
 804
 805         raw_spin_unlock_irqrestore(&db->lock, flags);
 806         if (!obj) {
 807                 struct debug_obj o = { .object = addr,
 808                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 809                                        .descr = descr };
 810
 811                 debug_print_object(&o, "deactivate");
 812         } else if (print_object) {
 813                 debug_print_object(obj, "deactivate");
 814         }
 815 }
 816 EXPORT_SYMBOL_GPL(debug_object_deactivate);
 817
 818 /**
 819  * debug_object_destroy - debug checks when an object is destroyed
 820  * @addr:       address of the object
 821  * @descr:      pointer to an object specific debug description structure
 822  */
 823 void debug_object_destroy(void *addr, const struct debug_obj_descr *descr)
 824 {
 825         enum debug_obj_state state;
 826         struct debug_bucket *db;
 827         struct debug_obj *obj;
 828         unsigned long flags;
 829         bool print_object = false;
 830
 831         if (!debug_objects_enabled)
 832                 return;
 833
 834         db = get_bucket((unsigned long) addr);
 835
 836         raw_spin_lock_irqsave(&db->lock, flags);
 837
 838         obj = lookup_object(addr, db);
 839         if (!obj)
 840                 goto out_unlock;
 841
 842         switch (obj->state) {
 843         case ODEBUG_STATE_NONE:
 844         case ODEBUG_STATE_INIT:
 845         case ODEBUG_STATE_INACTIVE:
 846                 obj->state = ODEBUG_STATE_DESTROYED;
 847                 break;
 848         case ODEBUG_STATE_ACTIVE:
 849                 state = obj->state;
 850                 raw_spin_unlock_irqrestore(&db->lock, flags);
 851                 debug_print_object(obj, "destroy");
 852                 debug_object_fixup(descr->fixup_destroy, addr, state);
 853                 return;
 854
 855         case ODEBUG_STATE_DESTROYED:
 856                 print_object = true;
 857                 break;
 858         default:
 859                 break;
 860         }
 861 out_unlock:
 862         raw_spin_unlock_irqrestore(&db->lock, flags);
 863         if (print_object)
 864                 debug_print_object(obj, "destroy");
 865 }
 866 EXPORT_SYMBOL_GPL(debug_object_destroy);
 867
 868 /**
 869  * debug_object_free - debug checks when an object is freed
 870  * @addr:       address of the object
 871  * @descr:      pointer to an object specific debug description structure
 872  */
 873 void debug_object_free(void *addr, const struct debug_obj_descr *descr)
 874 {
 875         enum debug_obj_state state;
 876         struct debug_bucket *db;
 877         struct debug_obj *obj;
 878         unsigned long flags;
 879
 880         if (!debug_objects_enabled)
 881                 return;
 882
 883         db = get_bucket((unsigned long) addr);
 884
 885         raw_spin_lock_irqsave(&db->lock, flags);
 886
 887         obj = lookup_object(addr, db);
 888         if (!obj)
 889                 goto out_unlock;
 890
 891         switch (obj->state) {
 892         case ODEBUG_STATE_ACTIVE:
 893                 state = obj->state;
 894                 raw_spin_unlock_irqrestore(&db->lock, flags);
 895                 debug_print_object(obj, "free");
 896                 debug_object_fixup(descr->fixup_free, addr, state);
 897                 return;
 898         default:
 899                 hlist_del(&obj->node);
 900                 raw_spin_unlock_irqrestore(&db->lock, flags);
 901                 free_object(obj);
 902                 return;
 903         }
 904 out_unlock:
 905         raw_spin_unlock_irqrestore(&db->lock, flags);
 906 }
 907 EXPORT_SYMBOL_GPL(debug_object_free);
 908
 909 /**
 910  * debug_object_assert_init - debug checks when object should be init-ed
 911  * @addr:       address of the object
 912  * @descr:      pointer to an object specific debug description structure
 913  */
 914 void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr)
 915 {
 916         struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
 917         struct debug_bucket *db;
 918         struct debug_obj *obj;
 919         unsigned long flags;
 920
 921         if (!debug_objects_enabled)
 922                 return;
 923
 924         debug_objects_fill_pool();
 925
 926         db = get_bucket((unsigned long) addr);
 927
 928         raw_spin_lock_irqsave(&db->lock, flags);
 929         obj = lookup_object_or_alloc(addr, db, descr, false, true);
 930         raw_spin_unlock_irqrestore(&db->lock, flags);
 931         if (likely(!IS_ERR_OR_NULL(obj)))
 932                 return;
 933
 934         /* If NULL the allocation has hit OOM */
 935         if (!obj) {
 936                 debug_objects_oom();
 937                 return;
 938         }
 939
 940         /* Object is neither tracked nor static. It's not initialized. */
 941         debug_print_object(&o, "assert_init");
 942         debug_object_fixup(descr->fixup_assert_init, addr, ODEBUG_STATE_NOTAVAILABLE);
 943 }
 944 EXPORT_SYMBOL_GPL(debug_object_assert_init);
 945
 946 /**
 947  * debug_object_active_state - debug checks object usage state machine
 948  * @addr:       address of the object
 949  * @descr:      pointer to an object specific debug description structure
 950  * @expect:     expected state
 951  * @next:       state to move to if expected state is found
 952  */
 953 void
 954 debug_object_active_state(void *addr, const struct debug_obj_descr *descr,
 955                           unsigned int expect, unsigned int next)
 956 {
 957         struct debug_bucket *db;
 958         struct debug_obj *obj;
 959         unsigned long flags;
 960         bool print_object = false;
 961
 962         if (!debug_objects_enabled)
 963                 return;
 964
 965         db = get_bucket((unsigned long) addr);
 966
 967         raw_spin_lock_irqsave(&db->lock, flags);
 968
 969         obj = lookup_object(addr, db);
 970         if (obj) {
 971                 switch (obj->state) {
 972                 case ODEBUG_STATE_ACTIVE:
 973                         if (obj->astate == expect)
 974                                 obj->astate = next;
 975                         else
 976                                 print_object = true;
 977                         break;
 978
 979                 default:
 980                         print_object = true;
 981                         break;
 982                 }
 983         }
 984
 985         raw_spin_unlock_irqrestore(&db->lock, flags);
 986         if (!obj) {
 987                 struct debug_obj o = { .object = addr,
 988                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 989                                        .descr = descr };
 990
 991                 debug_print_object(&o, "active_state");
 992         } else if (print_object) {
 993                 debug_print_object(obj, "active_state");
 994         }
 995 }
 996 EXPORT_SYMBOL_GPL(debug_object_active_state);
 997
 998 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 999 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
1000 {
1001         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
1002         const struct debug_obj_descr *descr;
1003         enum debug_obj_state state;
1004         struct debug_bucket *db;
1005         struct hlist_node *tmp;
1006         struct debug_obj *obj;
1007         int cnt, objs_checked = 0;
1008
1009         saddr = (unsigned long) address;
1010         eaddr = saddr + size;
1011         paddr = saddr & ODEBUG_CHUNK_MASK;
1012         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
1013         chunks >>= ODEBUG_CHUNK_SHIFT;
1014
1015         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
1016                 db = get_bucket(paddr);
1017
1018 repeat:
1019                 cnt = 0;
1020                 raw_spin_lock_irqsave(&db->lock, flags);
1021                 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
1022                         cnt++;
1023                         oaddr = (unsigned long) obj->object;
1024                         if (oaddr < saddr || oaddr >= eaddr)
1025                                 continue;
1026
1027                         switch (obj->state) {
1028                         case ODEBUG_STATE_ACTIVE:
1029                                 descr = obj->descr;
1030                                 state = obj->state;
1031                                 raw_spin_unlock_irqrestore(&db->lock, flags);
1032                                 debug_print_object(obj, "free");
1033                                 debug_object_fixup(descr->fixup_free,
1034                                                    (void *) oaddr, state);
1035                                 goto repeat;
1036                         default:
1037                                 hlist_del(&obj->node);
1038                                 __free_object(obj);
1039                                 break;
1040                         }
1041                 }
1042                 raw_spin_unlock_irqrestore(&db->lock, flags);
1043
1044                 if (cnt > debug_objects_maxchain)
1045                         debug_objects_maxchain = cnt;
1046
1047                 objs_checked += cnt;
1048         }
1049
1050         if (objs_checked > debug_objects_maxchecked)
1051                 debug_objects_maxchecked = objs_checked;
1052
1053         /* Schedule work to actually kmem_cache_free() objects */
1054         if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
1055                 WRITE_ONCE(obj_freeing, true);
1056                 schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
1057         }
1058 }
1059
1060 void debug_check_no_obj_freed(const void *address, unsigned long size)
1061 {
1062         if (debug_objects_enabled)
1063                 __debug_check_no_obj_freed(address, size);
1064 }
1065 #endif
1066
1067 #ifdef CONFIG_DEBUG_FS
1068
1069 static int debug_stats_show(struct seq_file *m, void *v)
1070 {
1071         int cpu, obj_percpu_free = 0;
1072
1073         for_each_possible_cpu(cpu)
1074                 obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu);
1075
1076         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
1077         seq_printf(m, "max_checked   :%d\n", debug_objects_maxchecked);
1078         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
1079         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
1080         seq_printf(m, "pool_free     :%d\n", READ_ONCE(obj_pool_free) + obj_percpu_free);
1081         seq_printf(m, "pool_pcp_free :%d\n", obj_percpu_free);
1082         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
1083         seq_printf(m, "pool_used     :%d\n", obj_pool_used - obj_percpu_free);
1084         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
1085         seq_printf(m, "on_free_list  :%d\n", READ_ONCE(obj_nr_tofree));
1086         seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
1087         seq_printf(m, "objs_freed    :%d\n", debug_objects_freed);
1088         return 0;
1089 }
1090 DEFINE_SHOW_ATTRIBUTE(debug_stats);
1091
1092 static int __init debug_objects_init_debugfs(void)
1093 {
1094         struct dentry *dbgdir;
1095
1096         if (!debug_objects_enabled)
1097                 return 0;
1098
1099         dbgdir = debugfs_create_dir("debug_objects", NULL);
1100
1101         debugfs_create_file("stats", 0444, dbgdir, NULL, &debug_stats_fops);
1102
1103         return 0;
1104 }
1105 __initcall(debug_objects_init_debugfs);
1106
1107 #else
1108 static inline void debug_objects_init_debugfs(void) { }
1109 #endif
1110
1111 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
1112
1113 /* Random data structure for the self test */
1114 struct self_test {
1115         unsigned long   dummy1[6];
1116         int             static_init;
1117         unsigned long   dummy2[3];
1118 };
1119
1120 static __initconst const struct debug_obj_descr descr_type_test;
1121
1122 static bool __init is_static_object(void *addr)
1123 {
1124         struct self_test *obj = addr;
1125
1126         return obj->static_init;
1127 }
1128
1129 /*
1130  * fixup_init is called when:
1131  * - an active object is initialized
1132  */
1133 static bool __init fixup_init(void *addr, enum debug_obj_state state)
1134 {
1135         struct self_test *obj = addr;
1136
1137         switch (state) {
1138         case ODEBUG_STATE_ACTIVE:
1139                 debug_object_deactivate(obj, &descr_type_test);
1140                 debug_object_init(obj, &descr_type_test);
1141                 return true;
1142         default:
1143                 return false;
1144         }
1145 }
1146
1147 /*
1148  * fixup_activate is called when:
1149  * - an active object is activated
1150  * - an unknown non-static object is activated
1151  */
1152 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
1153 {
1154         struct self_test *obj = addr;
1155
1156         switch (state) {
1157         case ODEBUG_STATE_NOTAVAILABLE:
1158                 return true;
1159         case ODEBUG_STATE_ACTIVE:
1160                 debug_object_deactivate(obj, &descr_type_test);
1161                 debug_object_activate(obj, &descr_type_test);
1162                 return true;
1163
1164         default:
1165                 return false;
1166         }
1167 }
1168
1169 /*
1170  * fixup_destroy is called when:
1171  * - an active object is destroyed
1172  */
1173 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
1174 {
1175         struct self_test *obj = addr;
1176
1177         switch (state) {
1178         case ODEBUG_STATE_ACTIVE:
1179                 debug_object_deactivate(obj, &descr_type_test);
1180                 debug_object_destroy(obj, &descr_type_test);
1181                 return true;
1182         default:
1183                 return false;
1184         }
1185 }
1186
1187 /*
1188  * fixup_free is called when:
1189  * - an active object is freed
1190  */
1191 static bool __init fixup_free(void *addr, enum debug_obj_state state)
1192 {
1193         struct self_test *obj = addr;
1194
1195         switch (state) {
1196         case ODEBUG_STATE_ACTIVE:
1197                 debug_object_deactivate(obj, &descr_type_test);
1198                 debug_object_free(obj, &descr_type_test);
1199                 return true;
1200         default:
1201                 return false;
1202         }
1203 }
1204
1205 static int __init
1206 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
1207 {
1208         struct debug_bucket *db;
1209         struct debug_obj *obj;
1210         unsigned long flags;
1211         int res = -EINVAL;
1212
1213         db = get_bucket((unsigned long) addr);
1214
1215         raw_spin_lock_irqsave(&db->lock, flags);
1216
1217         obj = lookup_object(addr, db);
1218         if (!obj && state != ODEBUG_STATE_NONE) {
1219                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
1220                 goto out;
1221         }
1222         if (obj && obj->state != state) {
1223                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
1224                        obj->state, state);
1225                 goto out;
1226         }
1227         if (fixups != debug_objects_fixups) {
1228                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
1229                        fixups, debug_objects_fixups);
1230                 goto out;
1231         }
1232         if (warnings != debug_objects_warnings) {
1233                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
1234                        warnings, debug_objects_warnings);
1235                 goto out;
1236         }
1237         res = 0;
1238 out:
1239         raw_spin_unlock_irqrestore(&db->lock, flags);
1240         if (res)
1241                 debug_objects_enabled = 0;
1242         return res;
1243 }
1244
1245 static __initconst const struct debug_obj_descr descr_type_test = {
1246         .name                   = "selftest",
1247         .is_static_object       = is_static_object,
1248         .fixup_init             = fixup_init,
1249         .fixup_activate         = fixup_activate,
1250         .fixup_destroy          = fixup_destroy,
1251         .fixup_free             = fixup_free,
1252 };
1253
1254 static __initdata struct self_test obj = { .static_init = 0 };
1255
1256 static void __init debug_objects_selftest(void)
1257 {
1258         int fixups, oldfixups, warnings, oldwarnings;
1259         unsigned long flags;
1260
1261         local_irq_save(flags);
1262
1263         fixups = oldfixups = debug_objects_fixups;
1264         warnings = oldwarnings = debug_objects_warnings;
1265         descr_test = &descr_type_test;
1266
1267         debug_object_init(&obj, &descr_type_test);
1268         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1269                 goto out;
1270         debug_object_activate(&obj, &descr_type_test);
1271         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1272                 goto out;
1273         debug_object_activate(&obj, &descr_type_test);
1274         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
1275                 goto out;
1276         debug_object_deactivate(&obj, &descr_type_test);
1277         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1278                 goto out;
1279         debug_object_destroy(&obj, &descr_type_test);
1280         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1281                 goto out;
1282         debug_object_init(&obj, &descr_type_test);
1283         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1284                 goto out;
1285         debug_object_activate(&obj, &descr_type_test);
1286         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1287                 goto out;
1288         debug_object_deactivate(&obj, &descr_type_test);
1289         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1290                 goto out;
1291         debug_object_free(&obj, &descr_type_test);
1292         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1293                 goto out;
1294
1295         obj.static_init = 1;
1296         debug_object_activate(&obj, &descr_type_test);
1297         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1298                 goto out;
1299         debug_object_init(&obj, &descr_type_test);
1300         if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
1301                 goto out;
1302         debug_object_free(&obj, &descr_type_test);
1303         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1304                 goto out;
1305
1306 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1307         debug_object_init(&obj, &descr_type_test);
1308         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1309                 goto out;
1310         debug_object_activate(&obj, &descr_type_test);
1311         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1312                 goto out;
1313         __debug_check_no_obj_freed(&obj, sizeof(obj));
1314         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1315                 goto out;
1316 #endif
1317         pr_info("selftest passed\n");
1318
1319 out:
1320         debug_objects_fixups = oldfixups;
1321         debug_objects_warnings = oldwarnings;
1322         descr_test = NULL;
1323
1324         local_irq_restore(flags);
1325 }
1326 #else
1327 static inline void debug_objects_selftest(void) { }
1328 #endif
1329
1330 /*
1331  * Called during early boot to initialize the hash buckets and link
1332  * the static object pool objects into the poll list. After this call
1333  * the object tracker is fully operational.
1334  */
1335 void __init debug_objects_early_init(void)
1336 {
1337         int i;
1338
1339         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1340                 raw_spin_lock_init(&obj_hash[i].lock);
1341
1342         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1343                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1344 }
1345
1346 /*
1347  * Convert the statically allocated objects to dynamic ones:
1348  */
1349 static int __init debug_objects_replace_static_objects(void)
1350 {
1351         struct debug_bucket *db = obj_hash;
1352         struct hlist_node *tmp;
1353         struct debug_obj *obj, *new;
1354         HLIST_HEAD(objects);
1355         int i, cnt = 0;
1356
1357         for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1358                 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1359                 if (!obj)
1360                         goto free;
1361                 hlist_add_head(&obj->node, &objects);
1362         }
1363
1364         debug_objects_allocated += i;
1365
1366         /*
1367          * debug_objects_mem_init() is now called early that only one CPU is up
1368          * and interrupts have been disabled, so it is safe to replace the
1369          * active object references.
1370          */
1371
1372         /* Remove the statically allocated objects from the pool */
1373         hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1374                 hlist_del(&obj->node);
1375         /* Move the allocated objects to the pool */
1376         hlist_move_list(&objects, &obj_pool);
1377
1378         /* Replace the active object references */
1379         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1380                 hlist_move_list(&db->list, &objects);
1381
1382                 hlist_for_each_entry(obj, &objects, node) {
1383                         new = hlist_entry(obj_pool.first, typeof(*obj), node);
1384                         hlist_del(&new->node);
1385                         /* copy object data */
1386                         *new = *obj;
1387                         hlist_add_head(&new->node, &db->list);
1388                         cnt++;
1389                 }
1390         }
1391
1392         pr_debug("%d of %d active objects replaced\n",
1393                  cnt, obj_pool_used);
1394         return 0;
1395 free:
1396         hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1397                 hlist_del(&obj->node);
1398                 kmem_cache_free(obj_cache, obj);
1399         }
1400         return -ENOMEM;
1401 }
1402
1403 /*
1404  * Called after the kmem_caches are functional to setup a dedicated
1405  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1406  * prevents that the debug code is called on kmem_cache_free() for the
1407  * debug tracker objects to avoid recursive calls.
1408  */
1409 void __init debug_objects_mem_init(void)
1410 {
1411         int cpu, extras;
1412
1413         if (!debug_objects_enabled)
1414                 return;
1415
1416         /*
1417          * Initialize the percpu object pools
1418          *
1419          * Initialization is not strictly necessary, but was done for
1420          * completeness.
1421          */
1422         for_each_possible_cpu(cpu)
1423                 INIT_HLIST_HEAD(&per_cpu(percpu_obj_pool.free_objs, cpu));
1424
1425         obj_cache = kmem_cache_create("debug_objects_cache",
1426                                       sizeof (struct debug_obj), 0,
1427                                       SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE,
1428                                       NULL);
1429
1430         if (!obj_cache || debug_objects_replace_static_objects()) {
1431                 debug_objects_enabled = 0;
1432                 kmem_cache_destroy(obj_cache);
1433                 pr_warn("out of memory.\n");
1434                 return;
1435         } else
1436                 debug_objects_selftest();
1437
1438 #ifdef CONFIG_HOTPLUG_CPU
1439         cpuhp_setup_state_nocalls(CPUHP_DEBUG_OBJ_DEAD, "object:offline", NULL,
1440                                         object_cpu_offline);
1441 #endif
1442
1443         /*
1444          * Increase the thresholds for allocating and freeing objects
1445          * according to the number of possible CPUs available in the system.
1446          */
1447         extras = num_possible_cpus() * ODEBUG_BATCH_SIZE;
1448         debug_objects_pool_size += extras;
1449         debug_objects_pool_min_level += extras;
1450 }