mm/slab.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef MM_SLAB_H
   3 #define MM_SLAB_H
   4
   5 #include <linux/reciprocal_div.h>
   6 #include <linux/list_lru.h>
   7 #include <linux/local_lock.h>
   8 #include <linux/random.h>
   9 #include <linux/kobject.h>
  10 #include <linux/sched/mm.h>
  11 #include <linux/memcontrol.h>
  12 #include <linux/kfence.h>
  13 #include <linux/kasan.h>
  14
  15 /*
  16  * Internal slab definitions
  17  */
  18
  19 #ifdef CONFIG_64BIT
  20 # ifdef system_has_cmpxchg128
  21 # define system_has_freelist_aba()      system_has_cmpxchg128()
  22 # define try_cmpxchg_freelist           try_cmpxchg128
  23 # endif
  24 #define this_cpu_try_cmpxchg_freelist   this_cpu_try_cmpxchg128
  25 typedef u128 freelist_full_t;
  26 #else /* CONFIG_64BIT */
  27 # ifdef system_has_cmpxchg64
  28 # define system_has_freelist_aba()      system_has_cmpxchg64()
  29 # define try_cmpxchg_freelist           try_cmpxchg64
  30 # endif
  31 #define this_cpu_try_cmpxchg_freelist   this_cpu_try_cmpxchg64
  32 typedef u64 freelist_full_t;
  33 #endif /* CONFIG_64BIT */
  34
  35 #if defined(system_has_freelist_aba) && !defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
  36 #undef system_has_freelist_aba
  37 #endif
  38
  39 /*
  40  * Freelist pointer and counter to cmpxchg together, avoids the typical ABA
  41  * problems with cmpxchg of just a pointer.
  42  */
  43 typedef union {
  44         struct {
  45                 void *freelist;
  46                 unsigned long counter;
  47         };
  48         freelist_full_t full;
  49 } freelist_aba_t;
  50
  51 /* Reuses the bits in struct page */
  52 struct slab {
  53         unsigned long __page_flags;
  54
  55         struct kmem_cache *slab_cache;
  56         union {
  57                 struct {
  58                         union {
  59                                 struct list_head slab_list;
  60 #ifdef CONFIG_SLUB_CPU_PARTIAL
  61                                 struct {
  62                                         struct slab *next;
  63                                         int slabs;      /* Nr of slabs left */
  64                                 };
  65 #endif
  66                         };
  67                         /* Double-word boundary */
  68                         union {
  69                                 struct {
  70                                         void *freelist;         /* first free object */
  71                                         union {
  72                                                 unsigned long counters;
  73                                                 struct {
  74                                                         unsigned inuse:16;
  75                                                         unsigned objects:15;
  76                                                         unsigned frozen:1;
  77                                                 };
  78                                         };
  79                                 };
  80 #ifdef system_has_freelist_aba
  81                                 freelist_aba_t freelist_counter;
  82 #endif
  83                         };
  84                 };
  85                 struct rcu_head rcu_head;
  86         };
  87
  88         unsigned int __page_type;
  89         atomic_t __page_refcount;
  90 #ifdef CONFIG_SLAB_OBJ_EXT
  91         unsigned long obj_exts;
  92 #endif
  93 };
  94
  95 #define SLAB_MATCH(pg, sl)                                              \
  96         static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
  97 SLAB_MATCH(flags, __page_flags);
  98 SLAB_MATCH(compound_head, slab_cache);  /* Ensure bit 0 is clear */
  99 SLAB_MATCH(_refcount, __page_refcount);
 100 #ifdef CONFIG_MEMCG
 101 SLAB_MATCH(memcg_data, obj_exts);
 102 #elif defined(CONFIG_SLAB_OBJ_EXT)
 103 SLAB_MATCH(_unused_slab_obj_exts, obj_exts);
 104 #endif
 105 #undef SLAB_MATCH
 106 static_assert(sizeof(struct slab) <= sizeof(struct page));
 107 #if defined(system_has_freelist_aba)
 108 static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t)));
 109 #endif
 110
 111 /**
 112  * folio_slab - Converts from folio to slab.
 113  * @folio: The folio.
 114  *
 115  * Currently struct slab is a different representation of a folio where
 116  * folio_test_slab() is true.
 117  *
 118  * Return: The slab which contains this folio.
 119  */
 120 #define folio_slab(folio)       (_Generic((folio),                      \
 121         const struct folio *:   (const struct slab *)(folio),           \
 122         struct folio *:         (struct slab *)(folio)))
 123
 124 /**
 125  * slab_folio - The folio allocated for a slab
 126  * @slab: The slab.
 127  *
 128  * Slabs are allocated as folios that contain the individual objects and are
 129  * using some fields in the first struct page of the folio - those fields are
 130  * now accessed by struct slab. It is occasionally necessary to convert back to
 131  * a folio in order to communicate with the rest of the mm.  Please use this
 132  * helper function instead of casting yourself, as the implementation may change
 133  * in the future.
 134  */
 135 #define slab_folio(s)           (_Generic((s),                          \
 136         const struct slab *:    (const struct folio *)s,                \
 137         struct slab *:          (struct folio *)s))
 138
 139 /**
 140  * page_slab - Converts from first struct page to slab.
 141  * @p: The first (either head of compound or single) page of slab.
 142  *
 143  * A temporary wrapper to convert struct page to struct slab in situations where
 144  * we know the page is the compound head, or single order-0 page.
 145  *
 146  * Long-term ideally everything would work with struct slab directly or go
 147  * through folio to struct slab.
 148  *
 149  * Return: The slab which contains this page
 150  */
 151 #define page_slab(p)            (_Generic((p),                          \
 152         const struct page *:    (const struct slab *)(p),               \
 153         struct page *:          (struct slab *)(p)))
 154
 155 /**
 156  * slab_page - The first struct page allocated for a slab
 157  * @slab: The slab.
 158  *
 159  * A convenience wrapper for converting slab to the first struct page of the
 160  * underlying folio, to communicate with code not yet converted to folio or
 161  * struct slab.
 162  */
 163 #define slab_page(s) folio_page(slab_folio(s), 0)
 164
 165 /*
 166  * If network-based swap is enabled, sl*b must keep track of whether pages
 167  * were allocated from pfmemalloc reserves.
 168  */
 169 static inline bool slab_test_pfmemalloc(const struct slab *slab)
 170 {
 171         return folio_test_active(slab_folio(slab));
 172 }
 173
 174 static inline void slab_set_pfmemalloc(struct slab *slab)
 175 {
 176         folio_set_active(slab_folio(slab));
 177 }
 178
 179 static inline void slab_clear_pfmemalloc(struct slab *slab)
 180 {
 181         folio_clear_active(slab_folio(slab));
 182 }
 183
 184 static inline void __slab_clear_pfmemalloc(struct slab *slab)
 185 {
 186         __folio_clear_active(slab_folio(slab));
 187 }
 188
 189 static inline void *slab_address(const struct slab *slab)
 190 {
 191         return folio_address(slab_folio(slab));
 192 }
 193
 194 static inline int slab_nid(const struct slab *slab)
 195 {
 196         return folio_nid(slab_folio(slab));
 197 }
 198
 199 static inline pg_data_t *slab_pgdat(const struct slab *slab)
 200 {
 201         return folio_pgdat(slab_folio(slab));
 202 }
 203
 204 static inline struct slab *virt_to_slab(const void *addr)
 205 {
 206         struct folio *folio = virt_to_folio(addr);
 207
 208         if (!folio_test_slab(folio))
 209                 return NULL;
 210
 211         return folio_slab(folio);
 212 }
 213
 214 static inline int slab_order(const struct slab *slab)
 215 {
 216         return folio_order(slab_folio(slab));
 217 }
 218
 219 static inline size_t slab_size(const struct slab *slab)
 220 {
 221         return PAGE_SIZE << slab_order(slab);
 222 }
 223
 224 #ifdef CONFIG_SLUB_CPU_PARTIAL
 225 #define slub_percpu_partial(c)                  ((c)->partial)
 226
 227 #define slub_set_percpu_partial(c, p)           \
 228 ({                                              \
 229         slub_percpu_partial(c) = (p)->next;     \
 230 })
 231
 232 #define slub_percpu_partial_read_once(c)        READ_ONCE(slub_percpu_partial(c))
 233 #else
 234 #define slub_percpu_partial(c)                  NULL
 235
 236 #define slub_set_percpu_partial(c, p)
 237
 238 #define slub_percpu_partial_read_once(c)        NULL
 239 #endif // CONFIG_SLUB_CPU_PARTIAL
 240
 241 /*
 242  * Word size structure that can be atomically updated or read and that
 243  * contains both the order and the number of objects that a slab of the
 244  * given order would contain.
 245  */
 246 struct kmem_cache_order_objects {
 247         unsigned int x;
 248 };
 249
 250 /*
 251  * Slab cache management.
 252  */
 253 struct kmem_cache {
 254 #ifndef CONFIG_SLUB_TINY
 255         struct kmem_cache_cpu __percpu *cpu_slab;
 256 #endif
 257         /* Used for retrieving partial slabs, etc. */
 258         slab_flags_t flags;
 259         unsigned long min_partial;
 260         unsigned int size;              /* Object size including metadata */
 261         unsigned int object_size;       /* Object size without metadata */
 262         struct reciprocal_value reciprocal_size;
 263         unsigned int offset;            /* Free pointer offset */
 264 #ifdef CONFIG_SLUB_CPU_PARTIAL
 265         /* Number of per cpu partial objects to keep around */
 266         unsigned int cpu_partial;
 267         /* Number of per cpu partial slabs to keep around */
 268         unsigned int cpu_partial_slabs;
 269 #endif
 270         struct kmem_cache_order_objects oo;
 271
 272         /* Allocation and freeing of slabs */
 273         struct kmem_cache_order_objects min;
 274         gfp_t allocflags;               /* gfp flags to use on each alloc */
 275         int refcount;                   /* Refcount for slab cache destroy */
 276         void (*ctor)(void *object);     /* Object constructor */
 277         unsigned int inuse;             /* Offset to metadata */
 278         unsigned int align;             /* Alignment */
 279         unsigned int red_left_pad;      /* Left redzone padding size */
 280         const char *name;               /* Name (only for display!) */
 281         struct list_head list;          /* List of slab caches */
 282 #ifdef CONFIG_SYSFS
 283         struct kobject kobj;            /* For sysfs */
 284 #endif
 285 #ifdef CONFIG_SLAB_FREELIST_HARDENED
 286         unsigned long random;
 287 #endif
 288
 289 #ifdef CONFIG_NUMA
 290         /*
 291          * Defragmentation by allocating from a remote node.
 292          */
 293         unsigned int remote_node_defrag_ratio;
 294 #endif
 295
 296 #ifdef CONFIG_SLAB_FREELIST_RANDOM
 297         unsigned int *random_seq;
 298 #endif
 299
 300 #ifdef CONFIG_KASAN_GENERIC
 301         struct kasan_cache kasan_info;
 302 #endif
 303
 304 #ifdef CONFIG_HARDENED_USERCOPY
 305         unsigned int useroffset;        /* Usercopy region offset */
 306         unsigned int usersize;          /* Usercopy region size */
 307 #endif
 308
 309         struct kmem_cache_node *node[MAX_NUMNODES];
 310 };
 311
 312 #if defined(CONFIG_SYSFS) && !defined(CONFIG_SLUB_TINY)
 313 #define SLAB_SUPPORTS_SYSFS
 314 void sysfs_slab_unlink(struct kmem_cache *s);
 315 void sysfs_slab_release(struct kmem_cache *s);
 316 #else
 317 static inline void sysfs_slab_unlink(struct kmem_cache *s) { }
 318 static inline void sysfs_slab_release(struct kmem_cache *s) { }
 319 #endif
 320
 321 void *fixup_red_left(struct kmem_cache *s, void *p);
 322
 323 static inline void *nearest_obj(struct kmem_cache *cache,
 324                                 const struct slab *slab, void *x)
 325 {
 326         void *object = x - (x - slab_address(slab)) % cache->size;
 327         void *last_object = slab_address(slab) +
 328                 (slab->objects - 1) * cache->size;
 329         void *result = (unlikely(object > last_object)) ? last_object : object;
 330
 331         result = fixup_red_left(cache, result);
 332         return result;
 333 }
 334
 335 /* Determine object index from a given position */
 336 static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
 337                                           void *addr, void *obj)
 338 {
 339         return reciprocal_divide(kasan_reset_tag(obj) - addr,
 340                                  cache->reciprocal_size);
 341 }
 342
 343 static inline unsigned int obj_to_index(const struct kmem_cache *cache,
 344                                         const struct slab *slab, void *obj)
 345 {
 346         if (is_kfence_address(obj))
 347                 return 0;
 348         return __obj_to_index(cache, slab_address(slab), obj);
 349 }
 350
 351 static inline int objs_per_slab(const struct kmem_cache *cache,
 352                                 const struct slab *slab)
 353 {
 354         return slab->objects;
 355 }
 356
 357 /*
 358  * State of the slab allocator.
 359  *
 360  * This is used to describe the states of the allocator during bootup.
 361  * Allocators use this to gradually bootstrap themselves. Most allocators
 362  * have the problem that the structures used for managing slab caches are
 363  * allocated from slab caches themselves.
 364  */
 365 enum slab_state {
 366         DOWN,                   /* No slab functionality yet */
 367         PARTIAL,                /* SLUB: kmem_cache_node available */
 368         UP,                     /* Slab caches usable but not all extras yet */
 369         FULL                    /* Everything is working */
 370 };
 371
 372 extern enum slab_state slab_state;
 373
 374 /* The slab cache mutex protects the management structures during changes */
 375 extern struct mutex slab_mutex;
 376
 377 /* The list of all slab caches on the system */
 378 extern struct list_head slab_caches;
 379
 380 /* The slab cache that manages slab cache information */
 381 extern struct kmem_cache *kmem_cache;
 382
 383 /* A table of kmalloc cache names and sizes */
 384 extern const struct kmalloc_info_struct {
 385         const char *name[NR_KMALLOC_TYPES];
 386         unsigned int size;
 387 } kmalloc_info[];
 388
 389 /* Kmalloc array related functions */
 390 void setup_kmalloc_cache_index_table(void);
 391 void create_kmalloc_caches(void);
 392
 393 extern u8 kmalloc_size_index[24];
 394
 395 static inline unsigned int size_index_elem(unsigned int bytes)
 396 {
 397         return (bytes - 1) / 8;
 398 }
 399
 400 /*
 401  * Find the kmem_cache structure that serves a given size of
 402  * allocation
 403  *
 404  * This assumes size is larger than zero and not larger than
 405  * KMALLOC_MAX_CACHE_SIZE and the caller must check that.
 406  */
 407 static inline struct kmem_cache *
 408 kmalloc_slab(size_t size, kmem_buckets *b, gfp_t flags, unsigned long caller)
 409 {
 410         unsigned int index;
 411
 412         if (!b)
 413                 b = &kmalloc_caches[kmalloc_type(flags, caller)];
 414         if (size <= 192)
 415                 index = kmalloc_size_index[size_index_elem(size)];
 416         else
 417                 index = fls(size - 1);
 418
 419         return (*b)[index];
 420 }
 421
 422 gfp_t kmalloc_fix_flags(gfp_t flags);
 423
 424 /* Functions provided by the slab allocators */
 425 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
 426
 427 void __init kmem_cache_init(void);
 428 extern void create_boot_cache(struct kmem_cache *, const char *name,
 429                         unsigned int size, slab_flags_t flags,
 430                         unsigned int useroffset, unsigned int usersize);
 431
 432 int slab_unmergeable(struct kmem_cache *s);
 433 struct kmem_cache *find_mergeable(unsigned size, unsigned align,
 434                 slab_flags_t flags, const char *name, void (*ctor)(void *));
 435 struct kmem_cache *
 436 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
 437                    slab_flags_t flags, void (*ctor)(void *));
 438
 439 slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name);
 440
 441 static inline bool is_kmalloc_cache(struct kmem_cache *s)
 442 {
 443         return (s->flags & SLAB_KMALLOC);
 444 }
 445
 446 /* Legal flag mask for kmem_cache_create(), for various configurations */
 447 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
 448                          SLAB_CACHE_DMA32 | SLAB_PANIC | \
 449                          SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
 450
 451 #ifdef CONFIG_SLUB_DEBUG
 452 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
 453                           SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
 454 #else
 455 #define SLAB_DEBUG_FLAGS (0)
 456 #endif
 457
 458 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
 459                           SLAB_TEMPORARY | SLAB_ACCOUNT | \
 460                           SLAB_NO_USER_FLAGS | SLAB_KMALLOC | SLAB_NO_MERGE)
 461
 462 /* Common flags available with current configuration */
 463 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
 464
 465 /* Common flags permitted for kmem_cache_create */
 466 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
 467                               SLAB_RED_ZONE | \
 468                               SLAB_POISON | \
 469                               SLAB_STORE_USER | \
 470                               SLAB_TRACE | \
 471                               SLAB_CONSISTENCY_CHECKS | \
 472                               SLAB_NOLEAKTRACE | \
 473                               SLAB_RECLAIM_ACCOUNT | \
 474                               SLAB_TEMPORARY | \
 475                               SLAB_ACCOUNT | \
 476                               SLAB_KMALLOC | \
 477                               SLAB_NO_MERGE | \
 478                               SLAB_NO_USER_FLAGS)
 479
 480 bool __kmem_cache_empty(struct kmem_cache *);
 481 int __kmem_cache_shutdown(struct kmem_cache *);
 482 void __kmem_cache_release(struct kmem_cache *);
 483 int __kmem_cache_shrink(struct kmem_cache *);
 484 void slab_kmem_cache_release(struct kmem_cache *);
 485
 486 struct seq_file;
 487 struct file;
 488
 489 struct slabinfo {
 490         unsigned long active_objs;
 491         unsigned long num_objs;
 492         unsigned long active_slabs;
 493         unsigned long num_slabs;
 494         unsigned long shared_avail;
 495         unsigned int limit;
 496         unsigned int batchcount;
 497         unsigned int shared;
 498         unsigned int objects_per_slab;
 499         unsigned int cache_order;
 500 };
 501
 502 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
 503
 504 #ifdef CONFIG_SLUB_DEBUG
 505 #ifdef CONFIG_SLUB_DEBUG_ON
 506 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
 507 #else
 508 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
 509 #endif
 510 extern void print_tracking(struct kmem_cache *s, void *object);
 511 long validate_slab_cache(struct kmem_cache *s);
 512 static inline bool __slub_debug_enabled(void)
 513 {
 514         return static_branch_unlikely(&slub_debug_enabled);
 515 }
 516 #else
 517 static inline void print_tracking(struct kmem_cache *s, void *object)
 518 {
 519 }
 520 static inline bool __slub_debug_enabled(void)
 521 {
 522         return false;
 523 }
 524 #endif
 525
 526 /*
 527  * Returns true if any of the specified slab_debug flags is enabled for the
 528  * cache. Use only for flags parsed by setup_slub_debug() as it also enables
 529  * the static key.
 530  */
 531 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
 532 {
 533         if (IS_ENABLED(CONFIG_SLUB_DEBUG))
 534                 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
 535         if (__slub_debug_enabled())
 536                 return s->flags & flags;
 537         return false;
 538 }
 539
 540 #ifdef CONFIG_SLAB_OBJ_EXT
 541
 542 /*
 543  * slab_obj_exts - get the pointer to the slab object extension vector
 544  * associated with a slab.
 545  * @slab: a pointer to the slab struct
 546  *
 547  * Returns a pointer to the object extension vector associated with the slab,
 548  * or NULL if no such vector has been associated yet.
 549  */
 550 static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
 551 {
 552         unsigned long obj_exts = READ_ONCE(slab->obj_exts);
 553
 554 #ifdef CONFIG_MEMCG
 555         VM_BUG_ON_PAGE(obj_exts && !(obj_exts & MEMCG_DATA_OBJEXTS),
 556                                                         slab_page(slab));
 557         VM_BUG_ON_PAGE(obj_exts & MEMCG_DATA_KMEM, slab_page(slab));
 558 #endif
 559         return (struct slabobj_ext *)(obj_exts & ~OBJEXTS_FLAGS_MASK);
 560 }
 561
 562 int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
 563                         gfp_t gfp, bool new_slab);
 564
 565 #else /* CONFIG_SLAB_OBJ_EXT */
 566
 567 static inline struct slabobj_ext *slab_obj_exts(struct slab *slab)
 568 {
 569         return NULL;
 570 }
 571
 572 #endif /* CONFIG_SLAB_OBJ_EXT */
 573
 574 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
 575 {
 576         return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
 577                 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
 578 }
 579
 580 #ifdef CONFIG_MEMCG
 581 bool __memcg_slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
 582                                   gfp_t flags, size_t size, void **p);
 583 void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
 584                             void **p, int objects, struct slabobj_ext *obj_exts);
 585 #endif
 586
 587 size_t __ksize(const void *objp);
 588
 589 static inline size_t slab_ksize(const struct kmem_cache *s)
 590 {
 591 #ifdef CONFIG_SLUB_DEBUG
 592         /*
 593          * Debugging requires use of the padding between object
 594          * and whatever may come after it.
 595          */
 596         if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
 597                 return s->object_size;
 598 #endif
 599         if (s->flags & SLAB_KASAN)
 600                 return s->object_size;
 601         /*
 602          * If we have the need to store the freelist pointer
 603          * back there or track user information then we can
 604          * only use the space before that information.
 605          */
 606         if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
 607                 return s->inuse;
 608         /*
 609          * Else we can use all the padding etc for the allocation
 610          */
 611         return s->size;
 612 }
 613
 614 #ifdef CONFIG_SLUB_DEBUG
 615 void dump_unreclaimable_slab(void);
 616 #else
 617 static inline void dump_unreclaimable_slab(void)
 618 {
 619 }
 620 #endif
 621
 622 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
 623
 624 #ifdef CONFIG_SLAB_FREELIST_RANDOM
 625 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
 626                         gfp_t gfp);
 627 void cache_random_seq_destroy(struct kmem_cache *cachep);
 628 #else
 629 static inline int cache_random_seq_create(struct kmem_cache *cachep,
 630                                         unsigned int count, gfp_t gfp)
 631 {
 632         return 0;
 633 }
 634 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
 635 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
 636
 637 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
 638 {
 639         if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
 640                                 &init_on_alloc)) {
 641                 if (c->ctor)
 642                         return false;
 643                 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
 644                         return flags & __GFP_ZERO;
 645                 return true;
 646         }
 647         return flags & __GFP_ZERO;
 648 }
 649
 650 static inline bool slab_want_init_on_free(struct kmem_cache *c)
 651 {
 652         if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
 653                                 &init_on_free))
 654                 return !(c->ctor ||
 655                          (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
 656         return false;
 657 }
 658
 659 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
 660 void debugfs_slab_release(struct kmem_cache *);
 661 #else
 662 static inline void debugfs_slab_release(struct kmem_cache *s) { }
 663 #endif
 664
 665 #ifdef CONFIG_PRINTK
 666 #define KS_ADDRS_COUNT 16
 667 struct kmem_obj_info {
 668         void *kp_ptr;
 669         struct slab *kp_slab;
 670         void *kp_objp;
 671         unsigned long kp_data_offset;
 672         struct kmem_cache *kp_slab_cache;
 673         void *kp_ret;
 674         void *kp_stack[KS_ADDRS_COUNT];
 675         void *kp_free_stack[KS_ADDRS_COUNT];
 676 };
 677 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
 678 #endif
 679
 680 void __check_heap_object(const void *ptr, unsigned long n,
 681                          const struct slab *slab, bool to_user);
 682
 683 #ifdef CONFIG_SLUB_DEBUG
 684 void skip_orig_size_check(struct kmem_cache *s, const void *object);
 685 #endif
 686
 687 #endif /* MM_SLAB_H */