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 struct kmem_cache *slab_cache; 15 union { 16 struct { 17 struct list_head slab_list; 18 void *freelist; /* array of free object indexes */ 19 void *s_mem; /* first object */ 20 }; 21 struct rcu_head rcu_head; 22 }; 23 unsigned int active; 24 25 #elif defined(CONFIG_SLUB) 26 27 struct kmem_cache *slab_cache; 28 union { 29 struct { 30 union { 31 struct list_head slab_list; 32 #ifdef CONFIG_SLUB_CPU_PARTIAL 33 struct { 34 struct slab *next; 35 int slabs; /* Nr of slabs left */ 36 }; 37 #endif 38 }; 39 /* Double-word boundary */ 40 void *freelist; /* first free object */ 41 union { 42 unsigned long counters; 43 struct { 44 unsigned inuse:16; 45 unsigned objects:15; 46 unsigned frozen:1; 47 }; 48 }; 49 }; 50 struct rcu_head rcu_head; 51 }; 52 unsigned int __unused; 53 54 #elif defined(CONFIG_SLOB) 55 56 struct list_head slab_list; 57 void *__unused_1; 58 void *freelist; /* first free block */ 59 long units; 60 unsigned int __unused_2; 61 62 #else 63 #error "Unexpected slab allocator configured" 64 #endif 65 66 atomic_t __page_refcount; 67 #ifdef CONFIG_MEMCG 68 unsigned long memcg_data; 69 #endif 70 }; 71 72 #define SLAB_MATCH(pg, sl) \ 73 static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl)) 74 SLAB_MATCH(flags, __page_flags); 75 #ifndef CONFIG_SLOB 76 SLAB_MATCH(compound_head, slab_cache); /* Ensure bit 0 is clear */ 77 #else 78 SLAB_MATCH(compound_head, slab_list); /* Ensure bit 0 is clear */ 79 #endif 80 SLAB_MATCH(_refcount, __page_refcount); 81 #ifdef CONFIG_MEMCG 82 SLAB_MATCH(memcg_data, memcg_data); 83 #endif 84 #undef SLAB_MATCH 85 static_assert(sizeof(struct slab) <= sizeof(struct page)); 86 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && defined(CONFIG_SLUB) 87 static_assert(IS_ALIGNED(offsetof(struct slab, freelist), 2*sizeof(void *))); 88 #endif 89 90 /** 91 * folio_slab - Converts from folio to slab. 92 * @folio: The folio. 93 * 94 * Currently struct slab is a different representation of a folio where 95 * folio_test_slab() is true. 96 * 97 * Return: The slab which contains this folio. 98 */ 99 #define folio_slab(folio) (_Generic((folio), \ 100 const struct folio *: (const struct slab *)(folio), \ 101 struct folio *: (struct slab *)(folio))) 102 103 /** 104 * slab_folio - The folio allocated for a slab 105 * @slab: The slab. 106 * 107 * Slabs are allocated as folios that contain the individual objects and are 108 * using some fields in the first struct page of the folio - those fields are 109 * now accessed by struct slab. It is occasionally necessary to convert back to 110 * a folio in order to communicate with the rest of the mm. Please use this 111 * helper function instead of casting yourself, as the implementation may change 112 * in the future. 113 */ 114 #define slab_folio(s) (_Generic((s), \ 115 const struct slab *: (const struct folio *)s, \ 116 struct slab *: (struct folio *)s)) 117 118 /** 119 * page_slab - Converts from first struct page to slab. 120 * @p: The first (either head of compound or single) page of slab. 121 * 122 * A temporary wrapper to convert struct page to struct slab in situations where 123 * we know the page is the compound head, or single order-0 page. 124 * 125 * Long-term ideally everything would work with struct slab directly or go 126 * through folio to struct slab. 127 * 128 * Return: The slab which contains this page 129 */ 130 #define page_slab(p) (_Generic((p), \ 131 const struct page *: (const struct slab *)(p), \ 132 struct page *: (struct slab *)(p))) 133 134 /** 135 * slab_page - The first struct page allocated for a slab 136 * @slab: The slab. 137 * 138 * A convenience wrapper for converting slab to the first struct page of the 139 * underlying folio, to communicate with code not yet converted to folio or 140 * struct slab. 141 */ 142 #define slab_page(s) folio_page(slab_folio(s), 0) 143 144 /* 145 * If network-based swap is enabled, sl*b must keep track of whether pages 146 * were allocated from pfmemalloc reserves. 147 */ 148 static inline bool slab_test_pfmemalloc(const struct slab *slab) 149 { 150 return folio_test_active((struct folio *)slab_folio(slab)); 151 } 152 153 static inline void slab_set_pfmemalloc(struct slab *slab) 154 { 155 folio_set_active(slab_folio(slab)); 156 } 157 158 static inline void slab_clear_pfmemalloc(struct slab *slab) 159 { 160 folio_clear_active(slab_folio(slab)); 161 } 162 163 static inline void __slab_clear_pfmemalloc(struct slab *slab) 164 { 165 __folio_clear_active(slab_folio(slab)); 166 } 167 168 static inline void *slab_address(const struct slab *slab) 169 { 170 return folio_address(slab_folio(slab)); 171 } 172 173 static inline int slab_nid(const struct slab *slab) 174 { 175 return folio_nid(slab_folio(slab)); 176 } 177 178 static inline pg_data_t *slab_pgdat(const struct slab *slab) 179 { 180 return folio_pgdat(slab_folio(slab)); 181 } 182 183 static inline struct slab *virt_to_slab(const void *addr) 184 { 185 struct folio *folio = virt_to_folio(addr); 186 187 if (!folio_test_slab(folio)) 188 return NULL; 189 190 return folio_slab(folio); 191 } 192 193 static inline int slab_order(const struct slab *slab) 194 { 195 return folio_order((struct folio *)slab_folio(slab)); 196 } 197 198 static inline size_t slab_size(const struct slab *slab) 199 { 200 return PAGE_SIZE << slab_order(slab); 201 } 202 203 #ifdef CONFIG_SLOB 204 /* 205 * Common fields provided in kmem_cache by all slab allocators 206 * This struct is either used directly by the allocator (SLOB) 207 * or the allocator must include definitions for all fields 208 * provided in kmem_cache_common in their definition of kmem_cache. 209 * 210 * Once we can do anonymous structs (C11 standard) we could put a 211 * anonymous struct definition in these allocators so that the 212 * separate allocations in the kmem_cache structure of SLAB and 213 * SLUB is no longer needed. 214 */ 215 struct kmem_cache { 216 unsigned int object_size;/* The original size of the object */ 217 unsigned int size; /* The aligned/padded/added on size */ 218 unsigned int align; /* Alignment as calculated */ 219 slab_flags_t flags; /* Active flags on the slab */ 220 const char *name; /* Slab name for sysfs */ 221 int refcount; /* Use counter */ 222 void (*ctor)(void *); /* Called on object slot creation */ 223 struct list_head list; /* List of all slab caches on the system */ 224 }; 225 226 #endif /* CONFIG_SLOB */ 227 228 #ifdef CONFIG_SLAB 229 #include <linux/slab_def.h> 230 #endif 231 232 #ifdef CONFIG_SLUB 233 #include <linux/slub_def.h> 234 #endif 235 236 #include <linux/memcontrol.h> 237 #include <linux/fault-inject.h> 238 #include <linux/kasan.h> 239 #include <linux/kmemleak.h> 240 #include <linux/random.h> 241 #include <linux/sched/mm.h> 242 #include <linux/list_lru.h> 243 244 /* 245 * State of the slab allocator. 246 * 247 * This is used to describe the states of the allocator during bootup. 248 * Allocators use this to gradually bootstrap themselves. Most allocators 249 * have the problem that the structures used for managing slab caches are 250 * allocated from slab caches themselves. 251 */ 252 enum slab_state { 253 DOWN, /* No slab functionality yet */ 254 PARTIAL, /* SLUB: kmem_cache_node available */ 255 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */ 256 UP, /* Slab caches usable but not all extras yet */ 257 FULL /* Everything is working */ 258 }; 259 260 extern enum slab_state slab_state; 261 262 /* The slab cache mutex protects the management structures during changes */ 263 extern struct mutex slab_mutex; 264 265 /* The list of all slab caches on the system */ 266 extern struct list_head slab_caches; 267 268 /* The slab cache that manages slab cache information */ 269 extern struct kmem_cache *kmem_cache; 270 271 /* A table of kmalloc cache names and sizes */ 272 extern const struct kmalloc_info_struct { 273 const char *name[NR_KMALLOC_TYPES]; 274 unsigned int size; 275 } kmalloc_info[]; 276 277 #ifndef CONFIG_SLOB 278 /* Kmalloc array related functions */ 279 void setup_kmalloc_cache_index_table(void); 280 void create_kmalloc_caches(slab_flags_t); 281 282 /* Find the kmalloc slab corresponding for a certain size */ 283 struct kmem_cache *kmalloc_slab(size_t, gfp_t); 284 285 void *__kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, 286 int node, size_t orig_size, 287 unsigned long caller); 288 void __kmem_cache_free(struct kmem_cache *s, void *x, unsigned long caller); 289 #endif 290 291 gfp_t kmalloc_fix_flags(gfp_t flags); 292 293 /* Functions provided by the slab allocators */ 294 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); 295 296 struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size, 297 slab_flags_t flags, unsigned int useroffset, 298 unsigned int usersize); 299 extern void create_boot_cache(struct kmem_cache *, const char *name, 300 unsigned int size, slab_flags_t flags, 301 unsigned int useroffset, unsigned int usersize); 302 303 int slab_unmergeable(struct kmem_cache *s); 304 struct kmem_cache *find_mergeable(unsigned size, unsigned align, 305 slab_flags_t flags, const char *name, void (*ctor)(void *)); 306 #ifndef CONFIG_SLOB 307 struct kmem_cache * 308 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, 309 slab_flags_t flags, void (*ctor)(void *)); 310 311 slab_flags_t kmem_cache_flags(unsigned int object_size, 312 slab_flags_t flags, const char *name); 313 #else 314 static inline struct kmem_cache * 315 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, 316 slab_flags_t flags, void (*ctor)(void *)) 317 { return NULL; } 318 319 static inline slab_flags_t kmem_cache_flags(unsigned int object_size, 320 slab_flags_t flags, const char *name) 321 { 322 return flags; 323 } 324 #endif 325 326 327 /* Legal flag mask for kmem_cache_create(), for various configurations */ 328 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \ 329 SLAB_CACHE_DMA32 | SLAB_PANIC | \ 330 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS ) 331 332 #if defined(CONFIG_DEBUG_SLAB) 333 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) 334 #elif defined(CONFIG_SLUB_DEBUG) 335 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ 336 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS) 337 #else 338 #define SLAB_DEBUG_FLAGS (0) 339 #endif 340 341 #if defined(CONFIG_SLAB) 342 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \ 343 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \ 344 SLAB_ACCOUNT) 345 #elif defined(CONFIG_SLUB) 346 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ 347 SLAB_TEMPORARY | SLAB_ACCOUNT | \ 348 SLAB_NO_USER_FLAGS | SLAB_KMALLOC) 349 #else 350 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE) 351 #endif 352 353 /* Common flags available with current configuration */ 354 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) 355 356 /* Common flags permitted for kmem_cache_create */ 357 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \ 358 SLAB_RED_ZONE | \ 359 SLAB_POISON | \ 360 SLAB_STORE_USER | \ 361 SLAB_TRACE | \ 362 SLAB_CONSISTENCY_CHECKS | \ 363 SLAB_MEM_SPREAD | \ 364 SLAB_NOLEAKTRACE | \ 365 SLAB_RECLAIM_ACCOUNT | \ 366 SLAB_TEMPORARY | \ 367 SLAB_ACCOUNT | \ 368 SLAB_KMALLOC | \ 369 SLAB_NO_USER_FLAGS) 370 371 bool __kmem_cache_empty(struct kmem_cache *); 372 int __kmem_cache_shutdown(struct kmem_cache *); 373 void __kmem_cache_release(struct kmem_cache *); 374 int __kmem_cache_shrink(struct kmem_cache *); 375 void slab_kmem_cache_release(struct kmem_cache *); 376 377 struct seq_file; 378 struct file; 379 380 struct slabinfo { 381 unsigned long active_objs; 382 unsigned long num_objs; 383 unsigned long active_slabs; 384 unsigned long num_slabs; 385 unsigned long shared_avail; 386 unsigned int limit; 387 unsigned int batchcount; 388 unsigned int shared; 389 unsigned int objects_per_slab; 390 unsigned int cache_order; 391 }; 392 393 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo); 394 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s); 395 ssize_t slabinfo_write(struct file *file, const char __user *buffer, 396 size_t count, loff_t *ppos); 397 398 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s) 399 { 400 return (s->flags & SLAB_RECLAIM_ACCOUNT) ? 401 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B; 402 } 403 404 #ifdef CONFIG_SLUB_DEBUG 405 #ifdef CONFIG_SLUB_DEBUG_ON 406 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled); 407 #else 408 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled); 409 #endif 410 extern void print_tracking(struct kmem_cache *s, void *object); 411 long validate_slab_cache(struct kmem_cache *s); 412 static inline bool __slub_debug_enabled(void) 413 { 414 return static_branch_unlikely(&slub_debug_enabled); 415 } 416 #else 417 static inline void print_tracking(struct kmem_cache *s, void *object) 418 { 419 } 420 static inline bool __slub_debug_enabled(void) 421 { 422 return false; 423 } 424 #endif 425 426 /* 427 * Returns true if any of the specified slub_debug flags is enabled for the 428 * cache. Use only for flags parsed by setup_slub_debug() as it also enables 429 * the static key. 430 */ 431 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags) 432 { 433 if (IS_ENABLED(CONFIG_SLUB_DEBUG)) 434 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS)); 435 if (__slub_debug_enabled()) 436 return s->flags & flags; 437 return false; 438 } 439 440 #ifdef CONFIG_MEMCG_KMEM 441 /* 442 * slab_objcgs - get the object cgroups vector associated with a slab 443 * @slab: a pointer to the slab struct 444 * 445 * Returns a pointer to the object cgroups vector associated with the slab, 446 * or NULL if no such vector has been associated yet. 447 */ 448 static inline struct obj_cgroup **slab_objcgs(struct slab *slab) 449 { 450 unsigned long memcg_data = READ_ONCE(slab->memcg_data); 451 452 VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), 453 slab_page(slab)); 454 VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab)); 455 456 return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); 457 } 458 459 int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, 460 gfp_t gfp, bool new_slab); 461 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, 462 enum node_stat_item idx, int nr); 463 464 static inline void memcg_free_slab_cgroups(struct slab *slab) 465 { 466 kfree(slab_objcgs(slab)); 467 slab->memcg_data = 0; 468 } 469 470 static inline size_t obj_full_size(struct kmem_cache *s) 471 { 472 /* 473 * For each accounted object there is an extra space which is used 474 * to store obj_cgroup membership. Charge it too. 475 */ 476 return s->size + sizeof(struct obj_cgroup *); 477 } 478 479 /* 480 * Returns false if the allocation should fail. 481 */ 482 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 483 struct list_lru *lru, 484 struct obj_cgroup **objcgp, 485 size_t objects, gfp_t flags) 486 { 487 struct obj_cgroup *objcg; 488 489 if (!memcg_kmem_enabled()) 490 return true; 491 492 if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)) 493 return true; 494 495 objcg = get_obj_cgroup_from_current(); 496 if (!objcg) 497 return true; 498 499 if (lru) { 500 int ret; 501 struct mem_cgroup *memcg; 502 503 memcg = get_mem_cgroup_from_objcg(objcg); 504 ret = memcg_list_lru_alloc(memcg, lru, flags); 505 css_put(&memcg->css); 506 507 if (ret) 508 goto out; 509 } 510 511 if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) 512 goto out; 513 514 *objcgp = objcg; 515 return true; 516 out: 517 obj_cgroup_put(objcg); 518 return false; 519 } 520 521 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 522 struct obj_cgroup *objcg, 523 gfp_t flags, size_t size, 524 void **p) 525 { 526 struct slab *slab; 527 unsigned long off; 528 size_t i; 529 530 if (!memcg_kmem_enabled() || !objcg) 531 return; 532 533 for (i = 0; i < size; i++) { 534 if (likely(p[i])) { 535 slab = virt_to_slab(p[i]); 536 537 if (!slab_objcgs(slab) && 538 memcg_alloc_slab_cgroups(slab, s, flags, 539 false)) { 540 obj_cgroup_uncharge(objcg, obj_full_size(s)); 541 continue; 542 } 543 544 off = obj_to_index(s, slab, p[i]); 545 obj_cgroup_get(objcg); 546 slab_objcgs(slab)[off] = objcg; 547 mod_objcg_state(objcg, slab_pgdat(slab), 548 cache_vmstat_idx(s), obj_full_size(s)); 549 } else { 550 obj_cgroup_uncharge(objcg, obj_full_size(s)); 551 } 552 } 553 obj_cgroup_put(objcg); 554 } 555 556 static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, 557 void **p, int objects) 558 { 559 struct obj_cgroup **objcgs; 560 int i; 561 562 if (!memcg_kmem_enabled()) 563 return; 564 565 objcgs = slab_objcgs(slab); 566 if (!objcgs) 567 return; 568 569 for (i = 0; i < objects; i++) { 570 struct obj_cgroup *objcg; 571 unsigned int off; 572 573 off = obj_to_index(s, slab, p[i]); 574 objcg = objcgs[off]; 575 if (!objcg) 576 continue; 577 578 objcgs[off] = NULL; 579 obj_cgroup_uncharge(objcg, obj_full_size(s)); 580 mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s), 581 -obj_full_size(s)); 582 obj_cgroup_put(objcg); 583 } 584 } 585 586 #else /* CONFIG_MEMCG_KMEM */ 587 static inline struct obj_cgroup **slab_objcgs(struct slab *slab) 588 { 589 return NULL; 590 } 591 592 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) 593 { 594 return NULL; 595 } 596 597 static inline int memcg_alloc_slab_cgroups(struct slab *slab, 598 struct kmem_cache *s, gfp_t gfp, 599 bool new_slab) 600 { 601 return 0; 602 } 603 604 static inline void memcg_free_slab_cgroups(struct slab *slab) 605 { 606 } 607 608 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 609 struct list_lru *lru, 610 struct obj_cgroup **objcgp, 611 size_t objects, gfp_t flags) 612 { 613 return true; 614 } 615 616 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 617 struct obj_cgroup *objcg, 618 gfp_t flags, size_t size, 619 void **p) 620 { 621 } 622 623 static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, 624 void **p, int objects) 625 { 626 } 627 #endif /* CONFIG_MEMCG_KMEM */ 628 629 #ifndef CONFIG_SLOB 630 static inline struct kmem_cache *virt_to_cache(const void *obj) 631 { 632 struct slab *slab; 633 634 slab = virt_to_slab(obj); 635 if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n", 636 __func__)) 637 return NULL; 638 return slab->slab_cache; 639 } 640 641 static __always_inline void account_slab(struct slab *slab, int order, 642 struct kmem_cache *s, gfp_t gfp) 643 { 644 if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT)) 645 memcg_alloc_slab_cgroups(slab, s, gfp, true); 646 647 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), 648 PAGE_SIZE << order); 649 } 650 651 static __always_inline void unaccount_slab(struct slab *slab, int order, 652 struct kmem_cache *s) 653 { 654 if (memcg_kmem_enabled()) 655 memcg_free_slab_cgroups(slab); 656 657 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), 658 -(PAGE_SIZE << order)); 659 } 660 661 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) 662 { 663 struct kmem_cache *cachep; 664 665 if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && 666 !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) 667 return s; 668 669 cachep = virt_to_cache(x); 670 if (WARN(cachep && cachep != s, 671 "%s: Wrong slab cache. %s but object is from %s\n", 672 __func__, s->name, cachep->name)) 673 print_tracking(cachep, x); 674 return cachep; 675 } 676 677 void free_large_kmalloc(struct folio *folio, void *object); 678 679 #endif /* CONFIG_SLOB */ 680 681 size_t __ksize(const void *objp); 682 683 static inline size_t slab_ksize(const struct kmem_cache *s) 684 { 685 #ifndef CONFIG_SLUB 686 return s->object_size; 687 688 #else /* CONFIG_SLUB */ 689 # ifdef CONFIG_SLUB_DEBUG 690 /* 691 * Debugging requires use of the padding between object 692 * and whatever may come after it. 693 */ 694 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) 695 return s->object_size; 696 # endif 697 if (s->flags & SLAB_KASAN) 698 return s->object_size; 699 /* 700 * If we have the need to store the freelist pointer 701 * back there or track user information then we can 702 * only use the space before that information. 703 */ 704 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER)) 705 return s->inuse; 706 /* 707 * Else we can use all the padding etc for the allocation 708 */ 709 return s->size; 710 #endif 711 } 712 713 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, 714 struct list_lru *lru, 715 struct obj_cgroup **objcgp, 716 size_t size, gfp_t flags) 717 { 718 flags &= gfp_allowed_mask; 719 720 might_alloc(flags); 721 722 if (should_failslab(s, flags)) 723 return NULL; 724 725 if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags)) 726 return NULL; 727 728 return s; 729 } 730 731 static inline void slab_post_alloc_hook(struct kmem_cache *s, 732 struct obj_cgroup *objcg, gfp_t flags, 733 size_t size, void **p, bool init, 734 unsigned int orig_size) 735 { 736 unsigned int zero_size = s->object_size; 737 size_t i; 738 739 flags &= gfp_allowed_mask; 740 741 /* 742 * For kmalloc object, the allocated memory size(object_size) is likely 743 * larger than the requested size(orig_size). If redzone check is 744 * enabled for the extra space, don't zero it, as it will be redzoned 745 * soon. The redzone operation for this extra space could be seen as a 746 * replacement of current poisoning under certain debug option, and 747 * won't break other sanity checks. 748 */ 749 if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) && 750 (s->flags & SLAB_KMALLOC)) 751 zero_size = orig_size; 752 753 /* 754 * As memory initialization might be integrated into KASAN, 755 * kasan_slab_alloc and initialization memset must be 756 * kept together to avoid discrepancies in behavior. 757 * 758 * As p[i] might get tagged, memset and kmemleak hook come after KASAN. 759 */ 760 for (i = 0; i < size; i++) { 761 p[i] = kasan_slab_alloc(s, p[i], flags, init); 762 if (p[i] && init && !kasan_has_integrated_init()) 763 memset(p[i], 0, zero_size); 764 kmemleak_alloc_recursive(p[i], s->object_size, 1, 765 s->flags, flags); 766 kmsan_slab_alloc(s, p[i], flags); 767 } 768 769 memcg_slab_post_alloc_hook(s, objcg, flags, size, p); 770 } 771 772 #ifndef CONFIG_SLOB 773 /* 774 * The slab lists for all objects. 775 */ 776 struct kmem_cache_node { 777 #ifdef CONFIG_SLAB 778 raw_spinlock_t list_lock; 779 struct list_head slabs_partial; /* partial list first, better asm code */ 780 struct list_head slabs_full; 781 struct list_head slabs_free; 782 unsigned long total_slabs; /* length of all slab lists */ 783 unsigned long free_slabs; /* length of free slab list only */ 784 unsigned long free_objects; 785 unsigned int free_limit; 786 unsigned int colour_next; /* Per-node cache coloring */ 787 struct array_cache *shared; /* shared per node */ 788 struct alien_cache **alien; /* on other nodes */ 789 unsigned long next_reap; /* updated without locking */ 790 int free_touched; /* updated without locking */ 791 #endif 792 793 #ifdef CONFIG_SLUB 794 spinlock_t list_lock; 795 unsigned long nr_partial; 796 struct list_head partial; 797 #ifdef CONFIG_SLUB_DEBUG 798 atomic_long_t nr_slabs; 799 atomic_long_t total_objects; 800 struct list_head full; 801 #endif 802 #endif 803 804 }; 805 806 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) 807 { 808 return s->node[node]; 809 } 810 811 /* 812 * Iterator over all nodes. The body will be executed for each node that has 813 * a kmem_cache_node structure allocated (which is true for all online nodes) 814 */ 815 #define for_each_kmem_cache_node(__s, __node, __n) \ 816 for (__node = 0; __node < nr_node_ids; __node++) \ 817 if ((__n = get_node(__s, __node))) 818 819 #endif 820 821 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) 822 void dump_unreclaimable_slab(void); 823 #else 824 static inline void dump_unreclaimable_slab(void) 825 { 826 } 827 #endif 828 829 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr); 830 831 #ifdef CONFIG_SLAB_FREELIST_RANDOM 832 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, 833 gfp_t gfp); 834 void cache_random_seq_destroy(struct kmem_cache *cachep); 835 #else 836 static inline int cache_random_seq_create(struct kmem_cache *cachep, 837 unsigned int count, gfp_t gfp) 838 { 839 return 0; 840 } 841 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } 842 #endif /* CONFIG_SLAB_FREELIST_RANDOM */ 843 844 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) 845 { 846 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, 847 &init_on_alloc)) { 848 if (c->ctor) 849 return false; 850 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) 851 return flags & __GFP_ZERO; 852 return true; 853 } 854 return flags & __GFP_ZERO; 855 } 856 857 static inline bool slab_want_init_on_free(struct kmem_cache *c) 858 { 859 if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, 860 &init_on_free)) 861 return !(c->ctor || 862 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); 863 return false; 864 } 865 866 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG) 867 void debugfs_slab_release(struct kmem_cache *); 868 #else 869 static inline void debugfs_slab_release(struct kmem_cache *s) { } 870 #endif 871 872 #ifdef CONFIG_PRINTK 873 #define KS_ADDRS_COUNT 16 874 struct kmem_obj_info { 875 void *kp_ptr; 876 struct slab *kp_slab; 877 void *kp_objp; 878 unsigned long kp_data_offset; 879 struct kmem_cache *kp_slab_cache; 880 void *kp_ret; 881 void *kp_stack[KS_ADDRS_COUNT]; 882 void *kp_free_stack[KS_ADDRS_COUNT]; 883 }; 884 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab); 885 #endif 886 887 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR 888 void __check_heap_object(const void *ptr, unsigned long n, 889 const struct slab *slab, bool to_user); 890 #else 891 static inline 892 void __check_heap_object(const void *ptr, unsigned long n, 893 const struct slab *slab, bool to_user) 894 { 895 } 896 #endif 897 898 #ifdef CONFIG_SLUB_DEBUG 899 void skip_orig_size_check(struct kmem_cache *s, const void *object); 900 #endif 901 902 #endif /* MM_SLAB_H */ 903