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 type: %s hint: %pS\n",
 516                         msg, obj_states[obj->state], obj->astate,
 517                         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:
 604          */
 605         if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible())
 606                 fill_pool();
 607 }
 608
 609 static void
 610 __debug_object_init(void *addr, const struct debug_obj_descr *descr, int onstack)
 611 {
 612         enum debug_obj_state state;
 613         struct debug_bucket *db;
 614         struct debug_obj *obj;
 615         unsigned long flags;
 616
 617         debug_objects_fill_pool();
 618
 619         db = get_bucket((unsigned long) addr);
 620
 621         raw_spin_lock_irqsave(&db->lock, flags);
 622
 623         obj = lookup_object_or_alloc(addr, db, descr, onstack, false);
 624         if (unlikely(!obj)) {
 625                 raw_spin_unlock_irqrestore(&db->lock, flags);
 626                 debug_objects_oom();
 627                 return;
 628         }
 629
 630         switch (obj->state) {
 631         case ODEBUG_STATE_NONE:
 632         case ODEBUG_STATE_INIT:
 633         case ODEBUG_STATE_INACTIVE:
 634                 obj->state = ODEBUG_STATE_INIT;
 635                 break;
 636
 637         case ODEBUG_STATE_ACTIVE:
 638                 state = obj->state;
 639                 raw_spin_unlock_irqrestore(&db->lock, flags);
 640                 debug_print_object(obj, "init");
 641                 debug_object_fixup(descr->fixup_init, addr, state);
 642                 return;
 643
 644         case ODEBUG_STATE_DESTROYED:
 645                 raw_spin_unlock_irqrestore(&db->lock, flags);
 646                 debug_print_object(obj, "init");
 647                 return;
 648         default:
 649                 break;
 650         }
 651
 652         raw_spin_unlock_irqrestore(&db->lock, flags);
 653 }
 654
 655 /**
 656  * debug_object_init - debug checks when an object is initialized
 657  * @addr:       address of the object
 658  * @descr:      pointer to an object specific debug description structure
 659  */
 660 void debug_object_init(void *addr, const struct debug_obj_descr *descr)
 661 {
 662         if (!debug_objects_enabled)
 663                 return;
 664
 665         __debug_object_init(addr, descr, 0);
 666 }
 667 EXPORT_SYMBOL_GPL(debug_object_init);
 668
 669 /**
 670  * debug_object_init_on_stack - debug checks when an object on stack is
 671  *                              initialized
 672  * @addr:       address of the object
 673  * @descr:      pointer to an object specific debug description structure
 674  */
 675 void debug_object_init_on_stack(void *addr, const struct debug_obj_descr *descr)
 676 {
 677         if (!debug_objects_enabled)
 678                 return;
 679
 680         __debug_object_init(addr, descr, 1);
 681 }
 682 EXPORT_SYMBOL_GPL(debug_object_init_on_stack);
 683
 684 /**
 685  * debug_object_activate - debug checks when an object is activated
 686  * @addr:       address of the object
 687  * @descr:      pointer to an object specific debug description structure
 688  * Returns 0 for success, -EINVAL for check failed.
 689  */
 690 int debug_object_activate(void *addr, const struct debug_obj_descr *descr)
 691 {
 692         struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
 693         enum debug_obj_state state;
 694         struct debug_bucket *db;
 695         struct debug_obj *obj;
 696         unsigned long flags;
 697         int ret;
 698
 699         if (!debug_objects_enabled)
 700                 return 0;
 701
 702         debug_objects_fill_pool();
 703
 704         db = get_bucket((unsigned long) addr);
 705
 706         raw_spin_lock_irqsave(&db->lock, flags);
 707
 708         obj = lookup_object_or_alloc(addr, db, descr, false, true);
 709         if (likely(!IS_ERR_OR_NULL(obj))) {
 710                 bool print_object = false;
 711
 712                 switch (obj->state) {
 713                 case ODEBUG_STATE_INIT:
 714                 case ODEBUG_STATE_INACTIVE:
 715                         obj->state = ODEBUG_STATE_ACTIVE;
 716                         ret = 0;
 717                         break;
 718
 719                 case ODEBUG_STATE_ACTIVE:
 720                         state = obj->state;
 721                         raw_spin_unlock_irqrestore(&db->lock, flags);
 722                         debug_print_object(obj, "activate");
 723                         ret = debug_object_fixup(descr->fixup_activate, addr, state);
 724                         return ret ? 0 : -EINVAL;
 725
 726                 case ODEBUG_STATE_DESTROYED:
 727                         print_object = true;
 728                         ret = -EINVAL;
 729                         break;
 730                 default:
 731                         ret = 0;
 732                         break;
 733                 }
 734                 raw_spin_unlock_irqrestore(&db->lock, flags);
 735                 if (print_object)
 736                         debug_print_object(obj, "activate");
 737                 return ret;
 738         }
 739
 740         raw_spin_unlock_irqrestore(&db->lock, flags);
 741
 742         /* If NULL the allocation has hit OOM */
 743         if (!obj) {
 744                 debug_objects_oom();
 745                 return 0;
 746         }
 747
 748         /* Object is neither static nor tracked. It's not initialized */
 749         debug_print_object(&o, "activate");
 750         ret = debug_object_fixup(descr->fixup_activate, addr, ODEBUG_STATE_NOTAVAILABLE);
 751         return ret ? 0 : -EINVAL;
 752 }
 753 EXPORT_SYMBOL_GPL(debug_object_activate);
 754
 755 /**
 756  * debug_object_deactivate - debug checks when an object is deactivated
 757  * @addr:       address of the object
 758  * @descr:      pointer to an object specific debug description structure
 759  */
 760 void debug_object_deactivate(void *addr, const struct debug_obj_descr *descr)
 761 {
 762         struct debug_bucket *db;
 763         struct debug_obj *obj;
 764         unsigned long flags;
 765         bool print_object = false;
 766
 767         if (!debug_objects_enabled)
 768                 return;
 769
 770         db = get_bucket((unsigned long) addr);
 771
 772         raw_spin_lock_irqsave(&db->lock, flags);
 773
 774         obj = lookup_object(addr, db);
 775         if (obj) {
 776                 switch (obj->state) {
 777                 case ODEBUG_STATE_INIT:
 778                 case ODEBUG_STATE_INACTIVE:
 779                 case ODEBUG_STATE_ACTIVE:
 780                         if (!obj->astate)
 781                                 obj->state = ODEBUG_STATE_INACTIVE;
 782                         else
 783                                 print_object = true;
 784                         break;
 785
 786                 case ODEBUG_STATE_DESTROYED:
 787                         print_object = true;
 788                         break;
 789                 default:
 790                         break;
 791                 }
 792         }
 793
 794         raw_spin_unlock_irqrestore(&db->lock, flags);
 795         if (!obj) {
 796                 struct debug_obj o = { .object = addr,
 797                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 798                                        .descr = descr };
 799
 800                 debug_print_object(&o, "deactivate");
 801         } else if (print_object) {
 802                 debug_print_object(obj, "deactivate");
 803         }
 804 }
 805 EXPORT_SYMBOL_GPL(debug_object_deactivate);
 806
 807 /**
 808  * debug_object_destroy - debug checks when an object is destroyed
 809  * @addr:       address of the object
 810  * @descr:      pointer to an object specific debug description structure
 811  */
 812 void debug_object_destroy(void *addr, const struct debug_obj_descr *descr)
 813 {
 814         enum debug_obj_state state;
 815         struct debug_bucket *db;
 816         struct debug_obj *obj;
 817         unsigned long flags;
 818         bool print_object = false;
 819
 820         if (!debug_objects_enabled)
 821                 return;
 822
 823         db = get_bucket((unsigned long) addr);
 824
 825         raw_spin_lock_irqsave(&db->lock, flags);
 826
 827         obj = lookup_object(addr, db);
 828         if (!obj)
 829                 goto out_unlock;
 830
 831         switch (obj->state) {
 832         case ODEBUG_STATE_NONE:
 833         case ODEBUG_STATE_INIT:
 834         case ODEBUG_STATE_INACTIVE:
 835                 obj->state = ODEBUG_STATE_DESTROYED;
 836                 break;
 837         case ODEBUG_STATE_ACTIVE:
 838                 state = obj->state;
 839                 raw_spin_unlock_irqrestore(&db->lock, flags);
 840                 debug_print_object(obj, "destroy");
 841                 debug_object_fixup(descr->fixup_destroy, addr, state);
 842                 return;
 843
 844         case ODEBUG_STATE_DESTROYED:
 845                 print_object = true;
 846                 break;
 847         default:
 848                 break;
 849         }
 850 out_unlock:
 851         raw_spin_unlock_irqrestore(&db->lock, flags);
 852         if (print_object)
 853                 debug_print_object(obj, "destroy");
 854 }
 855 EXPORT_SYMBOL_GPL(debug_object_destroy);
 856
 857 /**
 858  * debug_object_free - debug checks when an object is freed
 859  * @addr:       address of the object
 860  * @descr:      pointer to an object specific debug description structure
 861  */
 862 void debug_object_free(void *addr, const struct debug_obj_descr *descr)
 863 {
 864         enum debug_obj_state state;
 865         struct debug_bucket *db;
 866         struct debug_obj *obj;
 867         unsigned long flags;
 868
 869         if (!debug_objects_enabled)
 870                 return;
 871
 872         db = get_bucket((unsigned long) addr);
 873
 874         raw_spin_lock_irqsave(&db->lock, flags);
 875
 876         obj = lookup_object(addr, db);
 877         if (!obj)
 878                 goto out_unlock;
 879
 880         switch (obj->state) {
 881         case ODEBUG_STATE_ACTIVE:
 882                 state = obj->state;
 883                 raw_spin_unlock_irqrestore(&db->lock, flags);
 884                 debug_print_object(obj, "free");
 885                 debug_object_fixup(descr->fixup_free, addr, state);
 886                 return;
 887         default:
 888                 hlist_del(&obj->node);
 889                 raw_spin_unlock_irqrestore(&db->lock, flags);
 890                 free_object(obj);
 891                 return;
 892         }
 893 out_unlock:
 894         raw_spin_unlock_irqrestore(&db->lock, flags);
 895 }
 896 EXPORT_SYMBOL_GPL(debug_object_free);
 897
 898 /**
 899  * debug_object_assert_init - debug checks when object should be init-ed
 900  * @addr:       address of the object
 901  * @descr:      pointer to an object specific debug description structure
 902  */
 903 void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr)
 904 {
 905         struct debug_obj o = { .object = addr, .state = ODEBUG_STATE_NOTAVAILABLE, .descr = descr };
 906         struct debug_bucket *db;
 907         struct debug_obj *obj;
 908         unsigned long flags;
 909
 910         if (!debug_objects_enabled)
 911                 return;
 912
 913         debug_objects_fill_pool();
 914
 915         db = get_bucket((unsigned long) addr);
 916
 917         raw_spin_lock_irqsave(&db->lock, flags);
 918         obj = lookup_object_or_alloc(addr, db, descr, false, true);
 919         raw_spin_unlock_irqrestore(&db->lock, flags);
 920         if (likely(!IS_ERR_OR_NULL(obj)))
 921                 return;
 922
 923         /* If NULL the allocation has hit OOM */
 924         if (!obj) {
 925                 debug_objects_oom();
 926                 return;
 927         }
 928
 929         /* Object is neither tracked nor static. It's not initialized. */
 930         debug_print_object(&o, "assert_init");
 931         debug_object_fixup(descr->fixup_assert_init, addr, ODEBUG_STATE_NOTAVAILABLE);
 932 }
 933 EXPORT_SYMBOL_GPL(debug_object_assert_init);
 934
 935 /**
 936  * debug_object_active_state - debug checks object usage state machine
 937  * @addr:       address of the object
 938  * @descr:      pointer to an object specific debug description structure
 939  * @expect:     expected state
 940  * @next:       state to move to if expected state is found
 941  */
 942 void
 943 debug_object_active_state(void *addr, const struct debug_obj_descr *descr,
 944                           unsigned int expect, unsigned int next)
 945 {
 946         struct debug_bucket *db;
 947         struct debug_obj *obj;
 948         unsigned long flags;
 949         bool print_object = false;
 950
 951         if (!debug_objects_enabled)
 952                 return;
 953
 954         db = get_bucket((unsigned long) addr);
 955
 956         raw_spin_lock_irqsave(&db->lock, flags);
 957
 958         obj = lookup_object(addr, db);
 959         if (obj) {
 960                 switch (obj->state) {
 961                 case ODEBUG_STATE_ACTIVE:
 962                         if (obj->astate == expect)
 963                                 obj->astate = next;
 964                         else
 965                                 print_object = true;
 966                         break;
 967
 968                 default:
 969                         print_object = true;
 970                         break;
 971                 }
 972         }
 973
 974         raw_spin_unlock_irqrestore(&db->lock, flags);
 975         if (!obj) {
 976                 struct debug_obj o = { .object = addr,
 977                                        .state = ODEBUG_STATE_NOTAVAILABLE,
 978                                        .descr = descr };
 979
 980                 debug_print_object(&o, "active_state");
 981         } else if (print_object) {
 982                 debug_print_object(obj, "active_state");
 983         }
 984 }
 985 EXPORT_SYMBOL_GPL(debug_object_active_state);
 986
 987 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 988 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
 989 {
 990         unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
 991         const struct debug_obj_descr *descr;
 992         enum debug_obj_state state;
 993         struct debug_bucket *db;
 994         struct hlist_node *tmp;
 995         struct debug_obj *obj;
 996         int cnt, objs_checked = 0;
 997
 998         saddr = (unsigned long) address;
 999         eaddr = saddr + size;
1000         paddr = saddr & ODEBUG_CHUNK_MASK;
1001         chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
1002         chunks >>= ODEBUG_CHUNK_SHIFT;
1003
1004         for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
1005                 db = get_bucket(paddr);
1006
1007 repeat:
1008                 cnt = 0;
1009                 raw_spin_lock_irqsave(&db->lock, flags);
1010                 hlist_for_each_entry_safe(obj, tmp, &db->list, node) {
1011                         cnt++;
1012                         oaddr = (unsigned long) obj->object;
1013                         if (oaddr < saddr || oaddr >= eaddr)
1014                                 continue;
1015
1016                         switch (obj->state) {
1017                         case ODEBUG_STATE_ACTIVE:
1018                                 descr = obj->descr;
1019                                 state = obj->state;
1020                                 raw_spin_unlock_irqrestore(&db->lock, flags);
1021                                 debug_print_object(obj, "free");
1022                                 debug_object_fixup(descr->fixup_free,
1023                                                    (void *) oaddr, state);
1024                                 goto repeat;
1025                         default:
1026                                 hlist_del(&obj->node);
1027                                 __free_object(obj);
1028                                 break;
1029                         }
1030                 }
1031                 raw_spin_unlock_irqrestore(&db->lock, flags);
1032
1033                 if (cnt > debug_objects_maxchain)
1034                         debug_objects_maxchain = cnt;
1035
1036                 objs_checked += cnt;
1037         }
1038
1039         if (objs_checked > debug_objects_maxchecked)
1040                 debug_objects_maxchecked = objs_checked;
1041
1042         /* Schedule work to actually kmem_cache_free() objects */
1043         if (!READ_ONCE(obj_freeing) && READ_ONCE(obj_nr_tofree)) {
1044                 WRITE_ONCE(obj_freeing, true);
1045                 schedule_delayed_work(&debug_obj_work, ODEBUG_FREE_WORK_DELAY);
1046         }
1047 }
1048
1049 void debug_check_no_obj_freed(const void *address, unsigned long size)
1050 {
1051         if (debug_objects_enabled)
1052                 __debug_check_no_obj_freed(address, size);
1053 }
1054 #endif
1055
1056 #ifdef CONFIG_DEBUG_FS
1057
1058 static int debug_stats_show(struct seq_file *m, void *v)
1059 {
1060         int cpu, obj_percpu_free = 0;
1061
1062         for_each_possible_cpu(cpu)
1063                 obj_percpu_free += per_cpu(percpu_obj_pool.obj_free, cpu);
1064
1065         seq_printf(m, "max_chain     :%d\n", debug_objects_maxchain);
1066         seq_printf(m, "max_checked   :%d\n", debug_objects_maxchecked);
1067         seq_printf(m, "warnings      :%d\n", debug_objects_warnings);
1068         seq_printf(m, "fixups        :%d\n", debug_objects_fixups);
1069         seq_printf(m, "pool_free     :%d\n", READ_ONCE(obj_pool_free) + obj_percpu_free);
1070         seq_printf(m, "pool_pcp_free :%d\n", obj_percpu_free);
1071         seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
1072         seq_printf(m, "pool_used     :%d\n", obj_pool_used - obj_percpu_free);
1073         seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
1074         seq_printf(m, "on_free_list  :%d\n", READ_ONCE(obj_nr_tofree));
1075         seq_printf(m, "objs_allocated:%d\n", debug_objects_allocated);
1076         seq_printf(m, "objs_freed    :%d\n", debug_objects_freed);
1077         return 0;
1078 }
1079 DEFINE_SHOW_ATTRIBUTE(debug_stats);
1080
1081 static int __init debug_objects_init_debugfs(void)
1082 {
1083         struct dentry *dbgdir;
1084
1085         if (!debug_objects_enabled)
1086                 return 0;
1087
1088         dbgdir = debugfs_create_dir("debug_objects", NULL);
1089
1090         debugfs_create_file("stats", 0444, dbgdir, NULL, &debug_stats_fops);
1091
1092         return 0;
1093 }
1094 __initcall(debug_objects_init_debugfs);
1095
1096 #else
1097 static inline void debug_objects_init_debugfs(void) { }
1098 #endif
1099
1100 #ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
1101
1102 /* Random data structure for the self test */
1103 struct self_test {
1104         unsigned long   dummy1[6];
1105         int             static_init;
1106         unsigned long   dummy2[3];
1107 };
1108
1109 static __initconst const struct debug_obj_descr descr_type_test;
1110
1111 static bool __init is_static_object(void *addr)
1112 {
1113         struct self_test *obj = addr;
1114
1115         return obj->static_init;
1116 }
1117
1118 /*
1119  * fixup_init is called when:
1120  * - an active object is initialized
1121  */
1122 static bool __init fixup_init(void *addr, enum debug_obj_state state)
1123 {
1124         struct self_test *obj = addr;
1125
1126         switch (state) {
1127         case ODEBUG_STATE_ACTIVE:
1128                 debug_object_deactivate(obj, &descr_type_test);
1129                 debug_object_init(obj, &descr_type_test);
1130                 return true;
1131         default:
1132                 return false;
1133         }
1134 }
1135
1136 /*
1137  * fixup_activate is called when:
1138  * - an active object is activated
1139  * - an unknown non-static object is activated
1140  */
1141 static bool __init fixup_activate(void *addr, enum debug_obj_state state)
1142 {
1143         struct self_test *obj = addr;
1144
1145         switch (state) {
1146         case ODEBUG_STATE_NOTAVAILABLE:
1147                 return true;
1148         case ODEBUG_STATE_ACTIVE:
1149                 debug_object_deactivate(obj, &descr_type_test);
1150                 debug_object_activate(obj, &descr_type_test);
1151                 return true;
1152
1153         default:
1154                 return false;
1155         }
1156 }
1157
1158 /*
1159  * fixup_destroy is called when:
1160  * - an active object is destroyed
1161  */
1162 static bool __init fixup_destroy(void *addr, enum debug_obj_state state)
1163 {
1164         struct self_test *obj = addr;
1165
1166         switch (state) {
1167         case ODEBUG_STATE_ACTIVE:
1168                 debug_object_deactivate(obj, &descr_type_test);
1169                 debug_object_destroy(obj, &descr_type_test);
1170                 return true;
1171         default:
1172                 return false;
1173         }
1174 }
1175
1176 /*
1177  * fixup_free is called when:
1178  * - an active object is freed
1179  */
1180 static bool __init fixup_free(void *addr, enum debug_obj_state state)
1181 {
1182         struct self_test *obj = addr;
1183
1184         switch (state) {
1185         case ODEBUG_STATE_ACTIVE:
1186                 debug_object_deactivate(obj, &descr_type_test);
1187                 debug_object_free(obj, &descr_type_test);
1188                 return true;
1189         default:
1190                 return false;
1191         }
1192 }
1193
1194 static int __init
1195 check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
1196 {
1197         struct debug_bucket *db;
1198         struct debug_obj *obj;
1199         unsigned long flags;
1200         int res = -EINVAL;
1201
1202         db = get_bucket((unsigned long) addr);
1203
1204         raw_spin_lock_irqsave(&db->lock, flags);
1205
1206         obj = lookup_object(addr, db);
1207         if (!obj && state != ODEBUG_STATE_NONE) {
1208                 WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
1209                 goto out;
1210         }
1211         if (obj && obj->state != state) {
1212                 WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
1213                        obj->state, state);
1214                 goto out;
1215         }
1216         if (fixups != debug_objects_fixups) {
1217                 WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
1218                        fixups, debug_objects_fixups);
1219                 goto out;
1220         }
1221         if (warnings != debug_objects_warnings) {
1222                 WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
1223                        warnings, debug_objects_warnings);
1224                 goto out;
1225         }
1226         res = 0;
1227 out:
1228         raw_spin_unlock_irqrestore(&db->lock, flags);
1229         if (res)
1230                 debug_objects_enabled = 0;
1231         return res;
1232 }
1233
1234 static __initconst const struct debug_obj_descr descr_type_test = {
1235         .name                   = "selftest",
1236         .is_static_object       = is_static_object,
1237         .fixup_init             = fixup_init,
1238         .fixup_activate         = fixup_activate,
1239         .fixup_destroy          = fixup_destroy,
1240         .fixup_free             = fixup_free,
1241 };
1242
1243 static __initdata struct self_test obj = { .static_init = 0 };
1244
1245 static void __init debug_objects_selftest(void)
1246 {
1247         int fixups, oldfixups, warnings, oldwarnings;
1248         unsigned long flags;
1249
1250         local_irq_save(flags);
1251
1252         fixups = oldfixups = debug_objects_fixups;
1253         warnings = oldwarnings = debug_objects_warnings;
1254         descr_test = &descr_type_test;
1255
1256         debug_object_init(&obj, &descr_type_test);
1257         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1258                 goto out;
1259         debug_object_activate(&obj, &descr_type_test);
1260         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1261                 goto out;
1262         debug_object_activate(&obj, &descr_type_test);
1263         if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
1264                 goto out;
1265         debug_object_deactivate(&obj, &descr_type_test);
1266         if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
1267                 goto out;
1268         debug_object_destroy(&obj, &descr_type_test);
1269         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
1270                 goto out;
1271         debug_object_init(&obj, &descr_type_test);
1272         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1273                 goto out;
1274         debug_object_activate(&obj, &descr_type_test);
1275         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1276                 goto out;
1277         debug_object_deactivate(&obj, &descr_type_test);
1278         if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
1279                 goto out;
1280         debug_object_free(&obj, &descr_type_test);
1281         if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
1282                 goto out;
1283
1284         obj.static_init = 1;
1285         debug_object_activate(&obj, &descr_type_test);
1286         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1287                 goto out;
1288         debug_object_init(&obj, &descr_type_test);
1289         if (check_results(&obj, ODEBUG_STATE_INIT, ++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 #ifdef CONFIG_DEBUG_OBJECTS_FREE
1296         debug_object_init(&obj, &descr_type_test);
1297         if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
1298                 goto out;
1299         debug_object_activate(&obj, &descr_type_test);
1300         if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
1301                 goto out;
1302         __debug_check_no_obj_freed(&obj, sizeof(obj));
1303         if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
1304                 goto out;
1305 #endif
1306         pr_info("selftest passed\n");
1307
1308 out:
1309         debug_objects_fixups = oldfixups;
1310         debug_objects_warnings = oldwarnings;
1311         descr_test = NULL;
1312
1313         local_irq_restore(flags);
1314 }
1315 #else
1316 static inline void debug_objects_selftest(void) { }
1317 #endif
1318
1319 /*
1320  * Called during early boot to initialize the hash buckets and link
1321  * the static object pool objects into the poll list. After this call
1322  * the object tracker is fully operational.
1323  */
1324 void __init debug_objects_early_init(void)
1325 {
1326         int i;
1327
1328         for (i = 0; i < ODEBUG_HASH_SIZE; i++)
1329                 raw_spin_lock_init(&obj_hash[i].lock);
1330
1331         for (i = 0; i < ODEBUG_POOL_SIZE; i++)
1332                 hlist_add_head(&obj_static_pool[i].node, &obj_pool);
1333 }
1334
1335 /*
1336  * Convert the statically allocated objects to dynamic ones:
1337  */
1338 static int __init debug_objects_replace_static_objects(void)
1339 {
1340         struct debug_bucket *db = obj_hash;
1341         struct hlist_node *tmp;
1342         struct debug_obj *obj, *new;
1343         HLIST_HEAD(objects);
1344         int i, cnt = 0;
1345
1346         for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
1347                 obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
1348                 if (!obj)
1349                         goto free;
1350                 hlist_add_head(&obj->node, &objects);
1351         }
1352
1353         debug_objects_allocated += i;
1354
1355         /*
1356          * debug_objects_mem_init() is now called early that only one CPU is up
1357          * and interrupts have been disabled, so it is safe to replace the
1358          * active object references.
1359          */
1360
1361         /* Remove the statically allocated objects from the pool */
1362         hlist_for_each_entry_safe(obj, tmp, &obj_pool, node)
1363                 hlist_del(&obj->node);
1364         /* Move the allocated objects to the pool */
1365         hlist_move_list(&objects, &obj_pool);
1366
1367         /* Replace the active object references */
1368         for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
1369                 hlist_move_list(&db->list, &objects);
1370
1371                 hlist_for_each_entry(obj, &objects, node) {
1372                         new = hlist_entry(obj_pool.first, typeof(*obj), node);
1373                         hlist_del(&new->node);
1374                         /* copy object data */
1375                         *new = *obj;
1376                         hlist_add_head(&new->node, &db->list);
1377                         cnt++;
1378                 }
1379         }
1380
1381         pr_debug("%d of %d active objects replaced\n",
1382                  cnt, obj_pool_used);
1383         return 0;
1384 free:
1385         hlist_for_each_entry_safe(obj, tmp, &objects, node) {
1386                 hlist_del(&obj->node);
1387                 kmem_cache_free(obj_cache, obj);
1388         }
1389         return -ENOMEM;
1390 }
1391
1392 /*
1393  * Called after the kmem_caches are functional to setup a dedicated
1394  * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
1395  * prevents that the debug code is called on kmem_cache_free() for the
1396  * debug tracker objects to avoid recursive calls.
1397  */
1398 void __init debug_objects_mem_init(void)
1399 {
1400         int cpu, extras;
1401
1402         if (!debug_objects_enabled)
1403                 return;
1404
1405         /*
1406          * Initialize the percpu object pools
1407          *
1408          * Initialization is not strictly necessary, but was done for
1409          * completeness.
1410          */
1411         for_each_possible_cpu(cpu)
1412                 INIT_HLIST_HEAD(&per_cpu(percpu_obj_pool.free_objs, cpu));
1413
1414         obj_cache = kmem_cache_create("debug_objects_cache",
1415                                       sizeof (struct debug_obj), 0,
1416                                       SLAB_DEBUG_OBJECTS | SLAB_NOLEAKTRACE,
1417                                       NULL);
1418
1419         if (!obj_cache || debug_objects_replace_static_objects()) {
1420                 debug_objects_enabled = 0;
1421                 kmem_cache_destroy(obj_cache);
1422                 pr_warn("out of memory.\n");
1423                 return;
1424         } else
1425                 debug_objects_selftest();
1426
1427 #ifdef CONFIG_HOTPLUG_CPU
1428         cpuhp_setup_state_nocalls(CPUHP_DEBUG_OBJ_DEAD, "object:offline", NULL,
1429                                         object_cpu_offline);
1430 #endif
1431
1432         /*
1433          * Increase the thresholds for allocating and freeing objects
1434          * according to the number of possible CPUs available in the system.
1435          */
1436         extras = num_possible_cpus() * ODEBUG_BATCH_SIZE;
1437         debug_objects_pool_size += extras;
1438         debug_objects_pool_min_level += extras;
1439 }