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 /* Reuses the bits in struct page */ 9 struct slab { 10 unsigned long __page_flags; 11 12 #if defined(CONFIG_SLAB) 13 14 union { 15 struct list_head slab_list; 16 struct rcu_head rcu_head; 17 }; 18 struct kmem_cache *slab_cache; 19 void *freelist; /* array of free object indexes */ 20 void *s_mem; /* first object */ 21 unsigned int active; 22 23 #elif defined(CONFIG_SLUB) 24 25 union { 26 struct list_head slab_list; 27 struct rcu_head rcu_head; 28 #ifdef CONFIG_SLUB_CPU_PARTIAL 29 struct { 30 struct slab *next; 31 int slabs; /* Nr of slabs left */ 32 }; 33 #endif 34 }; 35 struct kmem_cache *slab_cache; 36 /* Double-word boundary */ 37 void *freelist; /* first free object */ 38 union { 39 unsigned long counters; 40 struct { 41 unsigned inuse:16; 42 unsigned objects:15; 43 unsigned frozen:1; 44 }; 45 }; 46 unsigned int __unused; 47 48 #elif defined(CONFIG_SLOB) 49 50 struct list_head slab_list; 51 void *__unused_1; 52 void *freelist; /* first free block */ 53 long units; 54 unsigned int __unused_2; 55 56 #else 57 #error "Unexpected slab allocator configured" 58 #endif 59 60 atomic_t __page_refcount; 61 #ifdef CONFIG_MEMCG 62 unsigned long memcg_data; 63 #endif 64 }; 65 66 #define SLAB_MATCH(pg, sl) \ 67 static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl)) 68 SLAB_MATCH(flags, __page_flags); 69 SLAB_MATCH(compound_head, slab_list); /* Ensure bit 0 is clear */ 70 #ifndef CONFIG_SLOB 71 SLAB_MATCH(rcu_head, rcu_head); 72 #endif 73 SLAB_MATCH(_refcount, __page_refcount); 74 #ifdef CONFIG_MEMCG 75 SLAB_MATCH(memcg_data, memcg_data); 76 #endif 77 #undef SLAB_MATCH 78 static_assert(sizeof(struct slab) <= sizeof(struct page)); 79 80 /** 81 * folio_slab - Converts from folio to slab. 82 * @folio: The folio. 83 * 84 * Currently struct slab is a different representation of a folio where 85 * folio_test_slab() is true. 86 * 87 * Return: The slab which contains this folio. 88 */ 89 #define folio_slab(folio) (_Generic((folio), \ 90 const struct folio *: (const struct slab *)(folio), \ 91 struct folio *: (struct slab *)(folio))) 92 93 /** 94 * slab_folio - The folio allocated for a slab 95 * @slab: The slab. 96 * 97 * Slabs are allocated as folios that contain the individual objects and are 98 * using some fields in the first struct page of the folio - those fields are 99 * now accessed by struct slab. It is occasionally necessary to convert back to 100 * a folio in order to communicate with the rest of the mm. Please use this 101 * helper function instead of casting yourself, as the implementation may change 102 * in the future. 103 */ 104 #define slab_folio(s) (_Generic((s), \ 105 const struct slab *: (const struct folio *)s, \ 106 struct slab *: (struct folio *)s)) 107 108 /** 109 * page_slab - Converts from first struct page to slab. 110 * @p: The first (either head of compound or single) page of slab. 111 * 112 * A temporary wrapper to convert struct page to struct slab in situations where 113 * we know the page is the compound head, or single order-0 page. 114 * 115 * Long-term ideally everything would work with struct slab directly or go 116 * through folio to struct slab. 117 * 118 * Return: The slab which contains this page 119 */ 120 #define page_slab(p) (_Generic((p), \ 121 const struct page *: (const struct slab *)(p), \ 122 struct page *: (struct slab *)(p))) 123 124 /** 125 * slab_page - The first struct page allocated for a slab 126 * @slab: The slab. 127 * 128 * A convenience wrapper for converting slab to the first struct page of the 129 * underlying folio, to communicate with code not yet converted to folio or 130 * struct slab. 131 */ 132 #define slab_page(s) folio_page(slab_folio(s), 0) 133 134 /* 135 * If network-based swap is enabled, sl*b must keep track of whether pages 136 * were allocated from pfmemalloc reserves. 137 */ 138 static inline bool slab_test_pfmemalloc(const struct slab *slab) 139 { 140 return folio_test_active((struct folio *)slab_folio(slab)); 141 } 142 143 static inline void slab_set_pfmemalloc(struct slab *slab) 144 { 145 folio_set_active(slab_folio(slab)); 146 } 147 148 static inline void slab_clear_pfmemalloc(struct slab *slab) 149 { 150 folio_clear_active(slab_folio(slab)); 151 } 152 153 static inline void __slab_clear_pfmemalloc(struct slab *slab) 154 { 155 __folio_clear_active(slab_folio(slab)); 156 } 157 158 static inline void *slab_address(const struct slab *slab) 159 { 160 return folio_address(slab_folio(slab)); 161 } 162 163 static inline int slab_nid(const struct slab *slab) 164 { 165 return folio_nid(slab_folio(slab)); 166 } 167 168 static inline pg_data_t *slab_pgdat(const struct slab *slab) 169 { 170 return folio_pgdat(slab_folio(slab)); 171 } 172 173 static inline struct slab *virt_to_slab(const void *addr) 174 { 175 struct folio *folio = virt_to_folio(addr); 176 177 if (!folio_test_slab(folio)) 178 return NULL; 179 180 return folio_slab(folio); 181 } 182 183 static inline int slab_order(const struct slab *slab) 184 { 185 return folio_order((struct folio *)slab_folio(slab)); 186 } 187 188 static inline size_t slab_size(const struct slab *slab) 189 { 190 return PAGE_SIZE << slab_order(slab); 191 } 192 193 #ifdef CONFIG_SLOB 194 /* 195 * Common fields provided in kmem_cache by all slab allocators 196 * This struct is either used directly by the allocator (SLOB) 197 * or the allocator must include definitions for all fields 198 * provided in kmem_cache_common in their definition of kmem_cache. 199 * 200 * Once we can do anonymous structs (C11 standard) we could put a 201 * anonymous struct definition in these allocators so that the 202 * separate allocations in the kmem_cache structure of SLAB and 203 * SLUB is no longer needed. 204 */ 205 struct kmem_cache { 206 unsigned int object_size;/* The original size of the object */ 207 unsigned int size; /* The aligned/padded/added on size */ 208 unsigned int align; /* Alignment as calculated */ 209 slab_flags_t flags; /* Active flags on the slab */ 210 unsigned int useroffset;/* Usercopy region offset */ 211 unsigned int usersize; /* Usercopy region size */ 212 const char *name; /* Slab name for sysfs */ 213 int refcount; /* Use counter */ 214 void (*ctor)(void *); /* Called on object slot creation */ 215 struct list_head list; /* List of all slab caches on the system */ 216 }; 217 218 #endif /* CONFIG_SLOB */ 219 220 #ifdef CONFIG_SLAB 221 #include <linux/slab_def.h> 222 #endif 223 224 #ifdef CONFIG_SLUB 225 #include <linux/slub_def.h> 226 #endif 227 228 #include <linux/memcontrol.h> 229 #include <linux/fault-inject.h> 230 #include <linux/kasan.h> 231 #include <linux/kmemleak.h> 232 #include <linux/random.h> 233 #include <linux/sched/mm.h> 234 #include <linux/list_lru.h> 235 236 /* 237 * State of the slab allocator. 238 * 239 * This is used to describe the states of the allocator during bootup. 240 * Allocators use this to gradually bootstrap themselves. Most allocators 241 * have the problem that the structures used for managing slab caches are 242 * allocated from slab caches themselves. 243 */ 244 enum slab_state { 245 DOWN, /* No slab functionality yet */ 246 PARTIAL, /* SLUB: kmem_cache_node available */ 247 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */ 248 UP, /* Slab caches usable but not all extras yet */ 249 FULL /* Everything is working */ 250 }; 251 252 extern enum slab_state slab_state; 253 254 /* The slab cache mutex protects the management structures during changes */ 255 extern struct mutex slab_mutex; 256 257 /* The list of all slab caches on the system */ 258 extern struct list_head slab_caches; 259 260 /* The slab cache that manages slab cache information */ 261 extern struct kmem_cache *kmem_cache; 262 263 /* A table of kmalloc cache names and sizes */ 264 extern const struct kmalloc_info_struct { 265 const char *name[NR_KMALLOC_TYPES]; 266 unsigned int size; 267 } kmalloc_info[]; 268 269 #ifndef CONFIG_SLOB 270 /* Kmalloc array related functions */ 271 void setup_kmalloc_cache_index_table(void); 272 void create_kmalloc_caches(slab_flags_t); 273 274 /* Find the kmalloc slab corresponding for a certain size */ 275 struct kmem_cache *kmalloc_slab(size_t, gfp_t); 276 #endif 277 278 gfp_t kmalloc_fix_flags(gfp_t flags); 279 280 /* Functions provided by the slab allocators */ 281 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); 282 283 struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size, 284 slab_flags_t flags, unsigned int useroffset, 285 unsigned int usersize); 286 extern void create_boot_cache(struct kmem_cache *, const char *name, 287 unsigned int size, slab_flags_t flags, 288 unsigned int useroffset, unsigned int usersize); 289 290 int slab_unmergeable(struct kmem_cache *s); 291 struct kmem_cache *find_mergeable(unsigned size, unsigned align, 292 slab_flags_t flags, const char *name, void (*ctor)(void *)); 293 #ifndef CONFIG_SLOB 294 struct kmem_cache * 295 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, 296 slab_flags_t flags, void (*ctor)(void *)); 297 298 slab_flags_t kmem_cache_flags(unsigned int object_size, 299 slab_flags_t flags, const char *name); 300 #else 301 static inline struct kmem_cache * 302 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, 303 slab_flags_t flags, void (*ctor)(void *)) 304 { return NULL; } 305 306 static inline slab_flags_t kmem_cache_flags(unsigned int object_size, 307 slab_flags_t flags, const char *name) 308 { 309 return flags; 310 } 311 #endif 312 313 314 /* Legal flag mask for kmem_cache_create(), for various configurations */ 315 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \ 316 SLAB_CACHE_DMA32 | SLAB_PANIC | \ 317 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS ) 318 319 #if defined(CONFIG_DEBUG_SLAB) 320 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) 321 #elif defined(CONFIG_SLUB_DEBUG) 322 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ 323 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS) 324 #else 325 #define SLAB_DEBUG_FLAGS (0) 326 #endif 327 328 #if defined(CONFIG_SLAB) 329 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \ 330 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \ 331 SLAB_ACCOUNT) 332 #elif defined(CONFIG_SLUB) 333 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ 334 SLAB_TEMPORARY | SLAB_ACCOUNT) 335 #else 336 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE) 337 #endif 338 339 /* Common flags available with current configuration */ 340 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) 341 342 /* Common flags permitted for kmem_cache_create */ 343 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \ 344 SLAB_RED_ZONE | \ 345 SLAB_POISON | \ 346 SLAB_STORE_USER | \ 347 SLAB_TRACE | \ 348 SLAB_CONSISTENCY_CHECKS | \ 349 SLAB_MEM_SPREAD | \ 350 SLAB_NOLEAKTRACE | \ 351 SLAB_RECLAIM_ACCOUNT | \ 352 SLAB_TEMPORARY | \ 353 SLAB_ACCOUNT) 354 355 bool __kmem_cache_empty(struct kmem_cache *); 356 int __kmem_cache_shutdown(struct kmem_cache *); 357 void __kmem_cache_release(struct kmem_cache *); 358 int __kmem_cache_shrink(struct kmem_cache *); 359 void slab_kmem_cache_release(struct kmem_cache *); 360 361 struct seq_file; 362 struct file; 363 364 struct slabinfo { 365 unsigned long active_objs; 366 unsigned long num_objs; 367 unsigned long active_slabs; 368 unsigned long num_slabs; 369 unsigned long shared_avail; 370 unsigned int limit; 371 unsigned int batchcount; 372 unsigned int shared; 373 unsigned int objects_per_slab; 374 unsigned int cache_order; 375 }; 376 377 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo); 378 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s); 379 ssize_t slabinfo_write(struct file *file, const char __user *buffer, 380 size_t count, loff_t *ppos); 381 382 /* 383 * Generic implementation of bulk operations 384 * These are useful for situations in which the allocator cannot 385 * perform optimizations. In that case segments of the object listed 386 * may be allocated or freed using these operations. 387 */ 388 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 389 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 390 391 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s) 392 { 393 return (s->flags & SLAB_RECLAIM_ACCOUNT) ? 394 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B; 395 } 396 397 #ifdef CONFIG_SLUB_DEBUG 398 #ifdef CONFIG_SLUB_DEBUG_ON 399 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled); 400 #else 401 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled); 402 #endif 403 extern void print_tracking(struct kmem_cache *s, void *object); 404 long validate_slab_cache(struct kmem_cache *s); 405 static inline bool __slub_debug_enabled(void) 406 { 407 return static_branch_unlikely(&slub_debug_enabled); 408 } 409 #else 410 static inline void print_tracking(struct kmem_cache *s, void *object) 411 { 412 } 413 static inline bool __slub_debug_enabled(void) 414 { 415 return false; 416 } 417 #endif 418 419 /* 420 * Returns true if any of the specified slub_debug flags is enabled for the 421 * cache. Use only for flags parsed by setup_slub_debug() as it also enables 422 * the static key. 423 */ 424 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags) 425 { 426 if (IS_ENABLED(CONFIG_SLUB_DEBUG)) 427 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS)); 428 if (__slub_debug_enabled()) 429 return s->flags & flags; 430 return false; 431 } 432 433 #ifdef CONFIG_MEMCG_KMEM 434 /* 435 * slab_objcgs - get the object cgroups vector associated with a slab 436 * @slab: a pointer to the slab struct 437 * 438 * Returns a pointer to the object cgroups vector associated with the slab, 439 * or NULL if no such vector has been associated yet. 440 */ 441 static inline struct obj_cgroup **slab_objcgs(struct slab *slab) 442 { 443 unsigned long memcg_data = READ_ONCE(slab->memcg_data); 444 445 VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), 446 slab_page(slab)); 447 VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab)); 448 449 return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); 450 } 451 452 int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, 453 gfp_t gfp, bool new_slab); 454 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, 455 enum node_stat_item idx, int nr); 456 457 static inline void memcg_free_slab_cgroups(struct slab *slab) 458 { 459 kfree(slab_objcgs(slab)); 460 slab->memcg_data = 0; 461 } 462 463 static inline size_t obj_full_size(struct kmem_cache *s) 464 { 465 /* 466 * For each accounted object there is an extra space which is used 467 * to store obj_cgroup membership. Charge it too. 468 */ 469 return s->size + sizeof(struct obj_cgroup *); 470 } 471 472 /* 473 * Returns false if the allocation should fail. 474 */ 475 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 476 struct list_lru *lru, 477 struct obj_cgroup **objcgp, 478 size_t objects, gfp_t flags) 479 { 480 struct obj_cgroup *objcg; 481 482 if (!memcg_kmem_enabled()) 483 return true; 484 485 if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)) 486 return true; 487 488 objcg = get_obj_cgroup_from_current(); 489 if (!objcg) 490 return true; 491 492 if (lru) { 493 int ret; 494 struct mem_cgroup *memcg; 495 496 memcg = get_mem_cgroup_from_objcg(objcg); 497 ret = memcg_list_lru_alloc(memcg, lru, flags); 498 css_put(&memcg->css); 499 500 if (ret) 501 goto out; 502 } 503 504 if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) 505 goto out; 506 507 *objcgp = objcg; 508 return true; 509 out: 510 obj_cgroup_put(objcg); 511 return false; 512 } 513 514 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 515 struct obj_cgroup *objcg, 516 gfp_t flags, size_t size, 517 void **p) 518 { 519 struct slab *slab; 520 unsigned long off; 521 size_t i; 522 523 if (!memcg_kmem_enabled() || !objcg) 524 return; 525 526 for (i = 0; i < size; i++) { 527 if (likely(p[i])) { 528 slab = virt_to_slab(p[i]); 529 530 if (!slab_objcgs(slab) && 531 memcg_alloc_slab_cgroups(slab, s, flags, 532 false)) { 533 obj_cgroup_uncharge(objcg, obj_full_size(s)); 534 continue; 535 } 536 537 off = obj_to_index(s, slab, p[i]); 538 obj_cgroup_get(objcg); 539 slab_objcgs(slab)[off] = objcg; 540 mod_objcg_state(objcg, slab_pgdat(slab), 541 cache_vmstat_idx(s), obj_full_size(s)); 542 } else { 543 obj_cgroup_uncharge(objcg, obj_full_size(s)); 544 } 545 } 546 obj_cgroup_put(objcg); 547 } 548 549 static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, 550 void **p, int objects) 551 { 552 struct kmem_cache *s; 553 struct obj_cgroup **objcgs; 554 struct obj_cgroup *objcg; 555 struct slab *slab; 556 unsigned int off; 557 int i; 558 559 if (!memcg_kmem_enabled()) 560 return; 561 562 for (i = 0; i < objects; i++) { 563 if (unlikely(!p[i])) 564 continue; 565 566 slab = virt_to_slab(p[i]); 567 /* we could be given a kmalloc_large() object, skip those */ 568 if (!slab) 569 continue; 570 571 objcgs = slab_objcgs(slab); 572 if (!objcgs) 573 continue; 574 575 if (!s_orig) 576 s = slab->slab_cache; 577 else 578 s = s_orig; 579 580 off = obj_to_index(s, slab, p[i]); 581 objcg = objcgs[off]; 582 if (!objcg) 583 continue; 584 585 objcgs[off] = NULL; 586 obj_cgroup_uncharge(objcg, obj_full_size(s)); 587 mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s), 588 -obj_full_size(s)); 589 obj_cgroup_put(objcg); 590 } 591 } 592 593 #else /* CONFIG_MEMCG_KMEM */ 594 static inline struct obj_cgroup **slab_objcgs(struct slab *slab) 595 { 596 return NULL; 597 } 598 599 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) 600 { 601 return NULL; 602 } 603 604 static inline int memcg_alloc_slab_cgroups(struct slab *slab, 605 struct kmem_cache *s, gfp_t gfp, 606 bool new_slab) 607 { 608 return 0; 609 } 610 611 static inline void memcg_free_slab_cgroups(struct slab *slab) 612 { 613 } 614 615 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 616 struct list_lru *lru, 617 struct obj_cgroup **objcgp, 618 size_t objects, gfp_t flags) 619 { 620 return true; 621 } 622 623 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 624 struct obj_cgroup *objcg, 625 gfp_t flags, size_t size, 626 void **p) 627 { 628 } 629 630 static inline void memcg_slab_free_hook(struct kmem_cache *s, 631 void **p, int objects) 632 { 633 } 634 #endif /* CONFIG_MEMCG_KMEM */ 635 636 #ifndef CONFIG_SLOB 637 static inline struct kmem_cache *virt_to_cache(const void *obj) 638 { 639 struct slab *slab; 640 641 slab = virt_to_slab(obj); 642 if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n", 643 __func__)) 644 return NULL; 645 return slab->slab_cache; 646 } 647 648 static __always_inline void account_slab(struct slab *slab, int order, 649 struct kmem_cache *s, gfp_t gfp) 650 { 651 if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT)) 652 memcg_alloc_slab_cgroups(slab, s, gfp, true); 653 654 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), 655 PAGE_SIZE << order); 656 } 657 658 static __always_inline void unaccount_slab(struct slab *slab, int order, 659 struct kmem_cache *s) 660 { 661 if (memcg_kmem_enabled()) 662 memcg_free_slab_cgroups(slab); 663 664 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), 665 -(PAGE_SIZE << order)); 666 } 667 668 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) 669 { 670 struct kmem_cache *cachep; 671 672 if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && 673 !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) 674 return s; 675 676 cachep = virt_to_cache(x); 677 if (WARN(cachep && cachep != s, 678 "%s: Wrong slab cache. %s but object is from %s\n", 679 __func__, s->name, cachep->name)) 680 print_tracking(cachep, x); 681 return cachep; 682 } 683 #endif /* CONFIG_SLOB */ 684 685 static inline size_t slab_ksize(const struct kmem_cache *s) 686 { 687 #ifndef CONFIG_SLUB 688 return s->object_size; 689 690 #else /* CONFIG_SLUB */ 691 # ifdef CONFIG_SLUB_DEBUG 692 /* 693 * Debugging requires use of the padding between object 694 * and whatever may come after it. 695 */ 696 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) 697 return s->object_size; 698 # endif 699 if (s->flags & SLAB_KASAN) 700 return s->object_size; 701 /* 702 * If we have the need to store the freelist pointer 703 * back there or track user information then we can 704 * only use the space before that information. 705 */ 706 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER)) 707 return s->inuse; 708 /* 709 * Else we can use all the padding etc for the allocation 710 */ 711 return s->size; 712 #endif 713 } 714 715 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, 716 struct list_lru *lru, 717 struct obj_cgroup **objcgp, 718 size_t size, gfp_t flags) 719 { 720 flags &= gfp_allowed_mask; 721 722 might_alloc(flags); 723 724 if (should_failslab(s, flags)) 725 return NULL; 726 727 if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags)) 728 return NULL; 729 730 return s; 731 } 732 733 static inline void slab_post_alloc_hook(struct kmem_cache *s, 734 struct obj_cgroup *objcg, gfp_t flags, 735 size_t size, void **p, bool init) 736 { 737 size_t i; 738 739 flags &= gfp_allowed_mask; 740 741 /* 742 * As memory initialization might be integrated into KASAN, 743 * kasan_slab_alloc and initialization memset must be 744 * kept together to avoid discrepancies in behavior. 745 * 746 * As p[i] might get tagged, memset and kmemleak hook come after KASAN. 747 */ 748 for (i = 0; i < size; i++) { 749 p[i] = kasan_slab_alloc(s, p[i], flags, init); 750 if (p[i] && init && !kasan_has_integrated_init()) 751 memset(p[i], 0, s->object_size); 752 kmemleak_alloc_recursive(p[i], s->object_size, 1, 753 s->flags, flags); 754 } 755 756 memcg_slab_post_alloc_hook(s, objcg, flags, size, p); 757 } 758 759 #ifndef CONFIG_SLOB 760 /* 761 * The slab lists for all objects. 762 */ 763 struct kmem_cache_node { 764 spinlock_t list_lock; 765 766 #ifdef CONFIG_SLAB 767 struct list_head slabs_partial; /* partial list first, better asm code */ 768 struct list_head slabs_full; 769 struct list_head slabs_free; 770 unsigned long total_slabs; /* length of all slab lists */ 771 unsigned long free_slabs; /* length of free slab list only */ 772 unsigned long free_objects; 773 unsigned int free_limit; 774 unsigned int colour_next; /* Per-node cache coloring */ 775 struct array_cache *shared; /* shared per node */ 776 struct alien_cache **alien; /* on other nodes */ 777 unsigned long next_reap; /* updated without locking */ 778 int free_touched; /* updated without locking */ 779 #endif 780 781 #ifdef CONFIG_SLUB 782 unsigned long nr_partial; 783 struct list_head partial; 784 #ifdef CONFIG_SLUB_DEBUG 785 atomic_long_t nr_slabs; 786 atomic_long_t total_objects; 787 struct list_head full; 788 #endif 789 #endif 790 791 }; 792 793 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) 794 { 795 return s->node[node]; 796 } 797 798 /* 799 * Iterator over all nodes. The body will be executed for each node that has 800 * a kmem_cache_node structure allocated (which is true for all online nodes) 801 */ 802 #define for_each_kmem_cache_node(__s, __node, __n) \ 803 for (__node = 0; __node < nr_node_ids; __node++) \ 804 if ((__n = get_node(__s, __node))) 805 806 #endif 807 808 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) 809 void dump_unreclaimable_slab(void); 810 #else 811 static inline void dump_unreclaimable_slab(void) 812 { 813 } 814 #endif 815 816 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr); 817 818 #ifdef CONFIG_SLAB_FREELIST_RANDOM 819 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, 820 gfp_t gfp); 821 void cache_random_seq_destroy(struct kmem_cache *cachep); 822 #else 823 static inline int cache_random_seq_create(struct kmem_cache *cachep, 824 unsigned int count, gfp_t gfp) 825 { 826 return 0; 827 } 828 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } 829 #endif /* CONFIG_SLAB_FREELIST_RANDOM */ 830 831 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) 832 { 833 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, 834 &init_on_alloc)) { 835 if (c->ctor) 836 return false; 837 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) 838 return flags & __GFP_ZERO; 839 return true; 840 } 841 return flags & __GFP_ZERO; 842 } 843 844 static inline bool slab_want_init_on_free(struct kmem_cache *c) 845 { 846 if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, 847 &init_on_free)) 848 return !(c->ctor || 849 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); 850 return false; 851 } 852 853 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG) 854 void debugfs_slab_release(struct kmem_cache *); 855 #else 856 static inline void debugfs_slab_release(struct kmem_cache *s) { } 857 #endif 858 859 #ifdef CONFIG_PRINTK 860 #define KS_ADDRS_COUNT 16 861 struct kmem_obj_info { 862 void *kp_ptr; 863 struct slab *kp_slab; 864 void *kp_objp; 865 unsigned long kp_data_offset; 866 struct kmem_cache *kp_slab_cache; 867 void *kp_ret; 868 void *kp_stack[KS_ADDRS_COUNT]; 869 void *kp_free_stack[KS_ADDRS_COUNT]; 870 }; 871 void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab); 872 #endif 873 874 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 875 void __check_heap_object(const void *ptr, unsigned long n, 876 const struct slab *slab, bool to_user); 877 #else 878 static inline 879 void __check_heap_object(const void *ptr, unsigned long n, 880 const struct slab *slab, bool to_user) 881 { 882 } 883 #endif 884 885 #endif /* MM_SLAB_H */ 886