mm/slab.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef MM_SLAB_H
   3 #define MM_SLAB_H
   4 /*
   5  * Internal slab definitions
   6  */
   7
   8 #ifdef CONFIG_SLOB
   9 /*
  10  * Common fields provided in kmem_cache by all slab allocators
  11  * This struct is either used directly by the allocator (SLOB)
  12  * or the allocator must include definitions for all fields
  13  * provided in kmem_cache_common in their definition of kmem_cache.
  14  *
  15  * Once we can do anonymous structs (C11 standard) we could put a
  16  * anonymous struct definition in these allocators so that the
  17  * separate allocations in the kmem_cache structure of SLAB and
  18  * SLUB is no longer needed.
  19  */
  20 struct kmem_cache {
  21         unsigned int object_size;/* The original size of the object */
  22         unsigned int size;      /* The aligned/padded/added on size  */
  23         unsigned int align;     /* Alignment as calculated */
  24         slab_flags_t flags;     /* Active flags on the slab */
  25         unsigned int useroffset;/* Usercopy region offset */
  26         unsigned int usersize;  /* Usercopy region size */
  27         const char *name;       /* Slab name for sysfs */
  28         int refcount;           /* Use counter */
  29         void (*ctor)(void *);   /* Called on object slot creation */
  30         struct list_head list;  /* List of all slab caches on the system */
  31 };
  32
  33 #endif /* CONFIG_SLOB */
  34
  35 #ifdef CONFIG_SLAB
  36 #include <linux/slab_def.h>
  37 #endif
  38
  39 #ifdef CONFIG_SLUB
  40 #include <linux/slub_def.h>
  41 #endif
  42
  43 #include <linux/memcontrol.h>
  44 #include <linux/fault-inject.h>
  45 #include <linux/kasan.h>
  46 #include <linux/kmemleak.h>
  47 #include <linux/random.h>
  48 #include <linux/sched/mm.h>
  49
  50 /*
  51  * State of the slab allocator.
  52  *
  53  * This is used to describe the states of the allocator during bootup.
  54  * Allocators use this to gradually bootstrap themselves. Most allocators
  55  * have the problem that the structures used for managing slab caches are
  56  * allocated from slab caches themselves.
  57  */
  58 enum slab_state {
  59         DOWN,                   /* No slab functionality yet */
  60         PARTIAL,                /* SLUB: kmem_cache_node available */
  61         PARTIAL_NODE,           /* SLAB: kmalloc size for node struct available */
  62         UP,                     /* Slab caches usable but not all extras yet */
  63         FULL                    /* Everything is working */
  64 };
  65
  66 extern enum slab_state slab_state;
  67
  68 /* The slab cache mutex protects the management structures during changes */
  69 extern struct mutex slab_mutex;
  70
  71 /* The list of all slab caches on the system */
  72 extern struct list_head slab_caches;
  73
  74 /* The slab cache that manages slab cache information */
  75 extern struct kmem_cache *kmem_cache;
  76
  77 /* A table of kmalloc cache names and sizes */
  78 extern const struct kmalloc_info_struct {
  79         const char *name[NR_KMALLOC_TYPES];
  80         unsigned int size;
  81 } kmalloc_info[];
  82
  83 #ifndef CONFIG_SLOB
  84 /* Kmalloc array related functions */
  85 void setup_kmalloc_cache_index_table(void);
  86 void create_kmalloc_caches(slab_flags_t);
  87
  88 /* Find the kmalloc slab corresponding for a certain size */
  89 struct kmem_cache *kmalloc_slab(size_t, gfp_t);
  90 #endif
  91
  92 gfp_t kmalloc_fix_flags(gfp_t flags);
  93
  94 /* Functions provided by the slab allocators */
  95 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
  96
  97 struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
  98                         slab_flags_t flags, unsigned int useroffset,
  99                         unsigned int usersize);
 100 extern void create_boot_cache(struct kmem_cache *, const char *name,
 101                         unsigned int size, slab_flags_t flags,
 102                         unsigned int useroffset, unsigned int usersize);
 103
 104 int slab_unmergeable(struct kmem_cache *s);
 105 struct kmem_cache *find_mergeable(unsigned size, unsigned align,
 106                 slab_flags_t flags, const char *name, void (*ctor)(void *));
 107 #ifndef CONFIG_SLOB
 108 struct kmem_cache *
 109 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
 110                    slab_flags_t flags, void (*ctor)(void *));
 111
 112 slab_flags_t kmem_cache_flags(unsigned int object_size,
 113         slab_flags_t flags, const char *name);
 114 #else
 115 static inline struct kmem_cache *
 116 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
 117                    slab_flags_t flags, void (*ctor)(void *))
 118 { return NULL; }
 119
 120 static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
 121         slab_flags_t flags, const char *name)
 122 {
 123         return flags;
 124 }
 125 #endif
 126
 127
 128 /* Legal flag mask for kmem_cache_create(), for various configurations */
 129 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
 130                          SLAB_CACHE_DMA32 | SLAB_PANIC | \
 131                          SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
 132
 133 #if defined(CONFIG_DEBUG_SLAB)
 134 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
 135 #elif defined(CONFIG_SLUB_DEBUG)
 136 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
 137                           SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
 138 #else
 139 #define SLAB_DEBUG_FLAGS (0)
 140 #endif
 141
 142 #if defined(CONFIG_SLAB)
 143 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
 144                           SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
 145                           SLAB_ACCOUNT)
 146 #elif defined(CONFIG_SLUB)
 147 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
 148                           SLAB_TEMPORARY | SLAB_ACCOUNT)
 149 #else
 150 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE)
 151 #endif
 152
 153 /* Common flags available with current configuration */
 154 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
 155
 156 /* Common flags permitted for kmem_cache_create */
 157 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
 158                               SLAB_RED_ZONE | \
 159                               SLAB_POISON | \
 160                               SLAB_STORE_USER | \
 161                               SLAB_TRACE | \
 162                               SLAB_CONSISTENCY_CHECKS | \
 163                               SLAB_MEM_SPREAD | \
 164                               SLAB_NOLEAKTRACE | \
 165                               SLAB_RECLAIM_ACCOUNT | \
 166                               SLAB_TEMPORARY | \
 167                               SLAB_ACCOUNT)
 168
 169 bool __kmem_cache_empty(struct kmem_cache *);
 170 int __kmem_cache_shutdown(struct kmem_cache *);
 171 void __kmem_cache_release(struct kmem_cache *);
 172 int __kmem_cache_shrink(struct kmem_cache *);
 173 void slab_kmem_cache_release(struct kmem_cache *);
 174
 175 struct seq_file;
 176 struct file;
 177
 178 struct slabinfo {
 179         unsigned long active_objs;
 180         unsigned long num_objs;
 181         unsigned long active_slabs;
 182         unsigned long num_slabs;
 183         unsigned long shared_avail;
 184         unsigned int limit;
 185         unsigned int batchcount;
 186         unsigned int shared;
 187         unsigned int objects_per_slab;
 188         unsigned int cache_order;
 189 };
 190
 191 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
 192 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
 193 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 194                        size_t count, loff_t *ppos);
 195
 196 /*
 197  * Generic implementation of bulk operations
 198  * These are useful for situations in which the allocator cannot
 199  * perform optimizations. In that case segments of the object listed
 200  * may be allocated or freed using these operations.
 201  */
 202 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
 203 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
 204
 205 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
 206 {
 207         return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
 208                 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
 209 }
 210
 211 #ifdef CONFIG_SLUB_DEBUG
 212 #ifdef CONFIG_SLUB_DEBUG_ON
 213 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
 214 #else
 215 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
 216 #endif
 217 extern void print_tracking(struct kmem_cache *s, void *object);
 218 long validate_slab_cache(struct kmem_cache *s);
 219 static inline bool __slub_debug_enabled(void)
 220 {
 221         return static_branch_unlikely(&slub_debug_enabled);
 222 }
 223 #else
 224 static inline void print_tracking(struct kmem_cache *s, void *object)
 225 {
 226 }
 227 static inline bool __slub_debug_enabled(void)
 228 {
 229         return false;
 230 }
 231 #endif
 232
 233 /*
 234  * Returns true if any of the specified slub_debug flags is enabled for the
 235  * cache. Use only for flags parsed by setup_slub_debug() as it also enables
 236  * the static key.
 237  */
 238 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
 239 {
 240         if (IS_ENABLED(CONFIG_SLUB_DEBUG))
 241                 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
 242         if (__slub_debug_enabled())
 243                 return s->flags & flags;
 244         return false;
 245 }
 246
 247 #ifdef CONFIG_MEMCG_KMEM
 248 int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
 249                                  gfp_t gfp, bool new_page);
 250 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 251                      enum node_stat_item idx, int nr);
 252
 253 static inline void memcg_free_page_obj_cgroups(struct page *page)
 254 {
 255         kfree(page_objcgs(page));
 256         page->memcg_data = 0;
 257 }
 258
 259 static inline size_t obj_full_size(struct kmem_cache *s)
 260 {
 261         /*
 262          * For each accounted object there is an extra space which is used
 263          * to store obj_cgroup membership. Charge it too.
 264          */
 265         return s->size + sizeof(struct obj_cgroup *);
 266 }
 267
 268 /*
 269  * Returns false if the allocation should fail.
 270  */
 271 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
 272                                              struct obj_cgroup **objcgp,
 273                                              size_t objects, gfp_t flags)
 274 {
 275         struct obj_cgroup *objcg;
 276
 277         if (!memcg_kmem_enabled())
 278                 return true;
 279
 280         if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
 281                 return true;
 282
 283         objcg = get_obj_cgroup_from_current();
 284         if (!objcg)
 285                 return true;
 286
 287         if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) {
 288                 obj_cgroup_put(objcg);
 289                 return false;
 290         }
 291
 292         *objcgp = objcg;
 293         return true;
 294 }
 295
 296 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 297                                               struct obj_cgroup *objcg,
 298                                               gfp_t flags, size_t size,
 299                                               void **p)
 300 {
 301         struct page *page;
 302         unsigned long off;
 303         size_t i;
 304
 305         if (!memcg_kmem_enabled() || !objcg)
 306                 return;
 307
 308         for (i = 0; i < size; i++) {
 309                 if (likely(p[i])) {
 310                         page = virt_to_head_page(p[i]);
 311
 312                         if (!page_objcgs(page) &&
 313                             memcg_alloc_page_obj_cgroups(page, s, flags,
 314                                                          false)) {
 315                                 obj_cgroup_uncharge(objcg, obj_full_size(s));
 316                                 continue;
 317                         }
 318
 319                         off = obj_to_index(s, page, p[i]);
 320                         obj_cgroup_get(objcg);
 321                         page_objcgs(page)[off] = objcg;
 322                         mod_objcg_state(objcg, page_pgdat(page),
 323                                         cache_vmstat_idx(s), obj_full_size(s));
 324                 } else {
 325                         obj_cgroup_uncharge(objcg, obj_full_size(s));
 326                 }
 327         }
 328         obj_cgroup_put(objcg);
 329 }
 330
 331 static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
 332                                         void **p, int objects)
 333 {
 334         struct kmem_cache *s;
 335         struct obj_cgroup **objcgs;
 336         struct obj_cgroup *objcg;
 337         struct page *page;
 338         unsigned int off;
 339         int i;
 340
 341         if (!memcg_kmem_enabled())
 342                 return;
 343
 344         for (i = 0; i < objects; i++) {
 345                 if (unlikely(!p[i]))
 346                         continue;
 347
 348                 page = virt_to_head_page(p[i]);
 349                 objcgs = page_objcgs_check(page);
 350                 if (!objcgs)
 351                         continue;
 352
 353                 if (!s_orig)
 354                         s = page->slab_cache;
 355                 else
 356                         s = s_orig;
 357
 358                 off = obj_to_index(s, page, p[i]);
 359                 objcg = objcgs[off];
 360                 if (!objcg)
 361                         continue;
 362
 363                 objcgs[off] = NULL;
 364                 obj_cgroup_uncharge(objcg, obj_full_size(s));
 365                 mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s),
 366                                 -obj_full_size(s));
 367                 obj_cgroup_put(objcg);
 368         }
 369 }
 370
 371 #else /* CONFIG_MEMCG_KMEM */
 372 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
 373 {
 374         return NULL;
 375 }
 376
 377 static inline int memcg_alloc_page_obj_cgroups(struct page *page,
 378                                                struct kmem_cache *s, gfp_t gfp,
 379                                                bool new_page)
 380 {
 381         return 0;
 382 }
 383
 384 static inline void memcg_free_page_obj_cgroups(struct page *page)
 385 {
 386 }
 387
 388 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
 389                                              struct obj_cgroup **objcgp,
 390                                              size_t objects, gfp_t flags)
 391 {
 392         return true;
 393 }
 394
 395 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
 396                                               struct obj_cgroup *objcg,
 397                                               gfp_t flags, size_t size,
 398                                               void **p)
 399 {
 400 }
 401
 402 static inline void memcg_slab_free_hook(struct kmem_cache *s,
 403                                         void **p, int objects)
 404 {
 405 }
 406 #endif /* CONFIG_MEMCG_KMEM */
 407
 408 static inline struct kmem_cache *virt_to_cache(const void *obj)
 409 {
 410         struct page *page;
 411
 412         page = virt_to_head_page(obj);
 413         if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n",
 414                                         __func__))
 415                 return NULL;
 416         return page->slab_cache;
 417 }
 418
 419 static __always_inline void account_slab_page(struct page *page, int order,
 420                                               struct kmem_cache *s,
 421                                               gfp_t gfp)
 422 {
 423         if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT))
 424                 memcg_alloc_page_obj_cgroups(page, s, gfp, true);
 425
 426         mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
 427                             PAGE_SIZE << order);
 428 }
 429
 430 static __always_inline void unaccount_slab_page(struct page *page, int order,
 431                                                 struct kmem_cache *s)
 432 {
 433         if (memcg_kmem_enabled())
 434                 memcg_free_page_obj_cgroups(page);
 435
 436         mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
 437                             -(PAGE_SIZE << order));
 438 }
 439
 440 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 441 {
 442         struct kmem_cache *cachep;
 443
 444         if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
 445             !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
 446                 return s;
 447
 448         cachep = virt_to_cache(x);
 449         if (WARN(cachep && cachep != s,
 450                   "%s: Wrong slab cache. %s but object is from %s\n",
 451                   __func__, s->name, cachep->name))
 452                 print_tracking(cachep, x);
 453         return cachep;
 454 }
 455
 456 static inline size_t slab_ksize(const struct kmem_cache *s)
 457 {
 458 #ifndef CONFIG_SLUB
 459         return s->object_size;
 460
 461 #else /* CONFIG_SLUB */
 462 # ifdef CONFIG_SLUB_DEBUG
 463         /*
 464          * Debugging requires use of the padding between object
 465          * and whatever may come after it.
 466          */
 467         if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
 468                 return s->object_size;
 469 # endif
 470         if (s->flags & SLAB_KASAN)
 471                 return s->object_size;
 472         /*
 473          * If we have the need to store the freelist pointer
 474          * back there or track user information then we can
 475          * only use the space before that information.
 476          */
 477         if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
 478                 return s->inuse;
 479         /*
 480          * Else we can use all the padding etc for the allocation
 481          */
 482         return s->size;
 483 #endif
 484 }
 485
 486 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 487                                                      struct obj_cgroup **objcgp,
 488                                                      size_t size, gfp_t flags)
 489 {
 490         flags &= gfp_allowed_mask;
 491
 492         might_alloc(flags);
 493
 494         if (should_failslab(s, flags))
 495                 return NULL;
 496
 497         if (!memcg_slab_pre_alloc_hook(s, objcgp, size, flags))
 498                 return NULL;
 499
 500         return s;
 501 }
 502
 503 static inline void slab_post_alloc_hook(struct kmem_cache *s,
 504                                         struct obj_cgroup *objcg, gfp_t flags,
 505                                         size_t size, void **p, bool init)
 506 {
 507         size_t i;
 508
 509         flags &= gfp_allowed_mask;
 510
 511         /*
 512          * As memory initialization might be integrated into KASAN,
 513          * kasan_slab_alloc and initialization memset must be
 514          * kept together to avoid discrepancies in behavior.
 515          *
 516          * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
 517          */
 518         for (i = 0; i < size; i++) {
 519                 p[i] = kasan_slab_alloc(s, p[i], flags, init);
 520                 if (p[i] && init && !kasan_has_integrated_init())
 521                         memset(p[i], 0, s->object_size);
 522                 kmemleak_alloc_recursive(p[i], s->object_size, 1,
 523                                          s->flags, flags);
 524         }
 525
 526         memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
 527 }
 528
 529 #ifndef CONFIG_SLOB
 530 /*
 531  * The slab lists for all objects.
 532  */
 533 struct kmem_cache_node {
 534         spinlock_t list_lock;
 535
 536 #ifdef CONFIG_SLAB
 537         struct list_head slabs_partial; /* partial list first, better asm code */
 538         struct list_head slabs_full;
 539         struct list_head slabs_free;
 540         unsigned long total_slabs;      /* length of all slab lists */
 541         unsigned long free_slabs;       /* length of free slab list only */
 542         unsigned long free_objects;
 543         unsigned int free_limit;
 544         unsigned int colour_next;       /* Per-node cache coloring */
 545         struct array_cache *shared;     /* shared per node */
 546         struct alien_cache **alien;     /* on other nodes */
 547         unsigned long next_reap;        /* updated without locking */
 548         int free_touched;               /* updated without locking */
 549 #endif
 550
 551 #ifdef CONFIG_SLUB
 552         unsigned long nr_partial;
 553         struct list_head partial;
 554 #ifdef CONFIG_SLUB_DEBUG
 555         atomic_long_t nr_slabs;
 556         atomic_long_t total_objects;
 557         struct list_head full;
 558 #endif
 559 #endif
 560
 561 };
 562
 563 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
 564 {
 565         return s->node[node];
 566 }
 567
 568 /*
 569  * Iterator over all nodes. The body will be executed for each node that has
 570  * a kmem_cache_node structure allocated (which is true for all online nodes)
 571  */
 572 #define for_each_kmem_cache_node(__s, __node, __n) \
 573         for (__node = 0; __node < nr_node_ids; __node++) \
 574                  if ((__n = get_node(__s, __node)))
 575
 576 #endif
 577
 578 void *slab_start(struct seq_file *m, loff_t *pos);
 579 void *slab_next(struct seq_file *m, void *p, loff_t *pos);
 580 void slab_stop(struct seq_file *m, void *p);
 581 int memcg_slab_show(struct seq_file *m, void *p);
 582
 583 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
 584 void dump_unreclaimable_slab(void);
 585 #else
 586 static inline void dump_unreclaimable_slab(void)
 587 {
 588 }
 589 #endif
 590
 591 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
 592
 593 #ifdef CONFIG_SLAB_FREELIST_RANDOM
 594 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
 595                         gfp_t gfp);
 596 void cache_random_seq_destroy(struct kmem_cache *cachep);
 597 #else
 598 static inline int cache_random_seq_create(struct kmem_cache *cachep,
 599                                         unsigned int count, gfp_t gfp)
 600 {
 601         return 0;
 602 }
 603 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
 604 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
 605
 606 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
 607 {
 608         if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
 609                                 &init_on_alloc)) {
 610                 if (c->ctor)
 611                         return false;
 612                 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
 613                         return flags & __GFP_ZERO;
 614                 return true;
 615         }
 616         return flags & __GFP_ZERO;
 617 }
 618
 619 static inline bool slab_want_init_on_free(struct kmem_cache *c)
 620 {
 621         if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
 622                                 &init_on_free))
 623                 return !(c->ctor ||
 624                          (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
 625         return false;
 626 }
 627
 628 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
 629 void debugfs_slab_release(struct kmem_cache *);
 630 #else
 631 static inline void debugfs_slab_release(struct kmem_cache *s) { }
 632 #endif
 633
 634 #ifdef CONFIG_PRINTK
 635 #define KS_ADDRS_COUNT 16
 636 struct kmem_obj_info {
 637         void *kp_ptr;
 638         struct page *kp_page;
 639         void *kp_objp;
 640         unsigned long kp_data_offset;
 641         struct kmem_cache *kp_slab_cache;
 642         void *kp_ret;
 643         void *kp_stack[KS_ADDRS_COUNT];
 644         void *kp_free_stack[KS_ADDRS_COUNT];
 645 };
 646 void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page);
 647 #endif
 648
 649 #endif /* MM_SLAB_H */