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 void (*ctor)(void *)); 115 #else 116 static inline struct kmem_cache * 117 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, 118 slab_flags_t flags, void (*ctor)(void *)) 119 { return NULL; } 120 121 static inline slab_flags_t kmem_cache_flags(unsigned int object_size, 122 slab_flags_t flags, const char *name, 123 void (*ctor)(void *)) 124 { 125 return flags; 126 } 127 #endif 128 129 130 /* Legal flag mask for kmem_cache_create(), for various configurations */ 131 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \ 132 SLAB_CACHE_DMA32 | SLAB_PANIC | \ 133 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS ) 134 135 #if defined(CONFIG_DEBUG_SLAB) 136 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) 137 #elif defined(CONFIG_SLUB_DEBUG) 138 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ 139 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS) 140 #else 141 #define SLAB_DEBUG_FLAGS (0) 142 #endif 143 144 #if defined(CONFIG_SLAB) 145 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \ 146 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \ 147 SLAB_ACCOUNT) 148 #elif defined(CONFIG_SLUB) 149 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ 150 SLAB_TEMPORARY | SLAB_ACCOUNT) 151 #else 152 #define SLAB_CACHE_FLAGS (0) 153 #endif 154 155 /* Common flags available with current configuration */ 156 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) 157 158 /* Common flags permitted for kmem_cache_create */ 159 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \ 160 SLAB_RED_ZONE | \ 161 SLAB_POISON | \ 162 SLAB_STORE_USER | \ 163 SLAB_TRACE | \ 164 SLAB_CONSISTENCY_CHECKS | \ 165 SLAB_MEM_SPREAD | \ 166 SLAB_NOLEAKTRACE | \ 167 SLAB_RECLAIM_ACCOUNT | \ 168 SLAB_TEMPORARY | \ 169 SLAB_ACCOUNT) 170 171 bool __kmem_cache_empty(struct kmem_cache *); 172 int __kmem_cache_shutdown(struct kmem_cache *); 173 void __kmem_cache_release(struct kmem_cache *); 174 int __kmem_cache_shrink(struct kmem_cache *); 175 void slab_kmem_cache_release(struct kmem_cache *); 176 177 struct seq_file; 178 struct file; 179 180 struct slabinfo { 181 unsigned long active_objs; 182 unsigned long num_objs; 183 unsigned long active_slabs; 184 unsigned long num_slabs; 185 unsigned long shared_avail; 186 unsigned int limit; 187 unsigned int batchcount; 188 unsigned int shared; 189 unsigned int objects_per_slab; 190 unsigned int cache_order; 191 }; 192 193 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo); 194 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s); 195 ssize_t slabinfo_write(struct file *file, const char __user *buffer, 196 size_t count, loff_t *ppos); 197 198 /* 199 * Generic implementation of bulk operations 200 * These are useful for situations in which the allocator cannot 201 * perform optimizations. In that case segments of the object listed 202 * may be allocated or freed using these operations. 203 */ 204 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 205 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 206 207 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s) 208 { 209 return (s->flags & SLAB_RECLAIM_ACCOUNT) ? 210 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B; 211 } 212 213 #ifdef CONFIG_SLUB_DEBUG 214 #ifdef CONFIG_SLUB_DEBUG_ON 215 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled); 216 #else 217 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled); 218 #endif 219 extern void print_tracking(struct kmem_cache *s, void *object); 220 #else 221 static inline void print_tracking(struct kmem_cache *s, void *object) 222 { 223 } 224 #endif 225 226 /* 227 * Returns true if any of the specified slub_debug flags is enabled for the 228 * cache. Use only for flags parsed by setup_slub_debug() as it also enables 229 * the static key. 230 */ 231 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags) 232 { 233 #ifdef CONFIG_SLUB_DEBUG 234 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS)); 235 if (static_branch_unlikely(&slub_debug_enabled)) 236 return s->flags & flags; 237 #endif 238 return false; 239 } 240 241 #ifdef CONFIG_MEMCG_KMEM 242 int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, 243 gfp_t gfp); 244 245 static inline void memcg_free_page_obj_cgroups(struct page *page) 246 { 247 kfree(page_objcgs(page)); 248 page->memcg_data = 0; 249 } 250 251 static inline size_t obj_full_size(struct kmem_cache *s) 252 { 253 /* 254 * For each accounted object there is an extra space which is used 255 * to store obj_cgroup membership. Charge it too. 256 */ 257 return s->size + sizeof(struct obj_cgroup *); 258 } 259 260 /* 261 * Returns false if the allocation should fail. 262 */ 263 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 264 struct obj_cgroup **objcgp, 265 size_t objects, gfp_t flags) 266 { 267 struct obj_cgroup *objcg; 268 269 if (!memcg_kmem_enabled()) 270 return true; 271 272 if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)) 273 return true; 274 275 objcg = get_obj_cgroup_from_current(); 276 if (!objcg) 277 return true; 278 279 if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) { 280 obj_cgroup_put(objcg); 281 return false; 282 } 283 284 *objcgp = objcg; 285 return true; 286 } 287 288 static inline void mod_objcg_state(struct obj_cgroup *objcg, 289 struct pglist_data *pgdat, 290 enum node_stat_item idx, int nr) 291 { 292 struct mem_cgroup *memcg; 293 struct lruvec *lruvec; 294 295 rcu_read_lock(); 296 memcg = obj_cgroup_memcg(objcg); 297 lruvec = mem_cgroup_lruvec(memcg, pgdat); 298 mod_memcg_lruvec_state(lruvec, idx, nr); 299 rcu_read_unlock(); 300 } 301 302 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 303 struct obj_cgroup *objcg, 304 gfp_t flags, size_t size, 305 void **p) 306 { 307 struct page *page; 308 unsigned long off; 309 size_t i; 310 311 if (!memcg_kmem_enabled() || !objcg) 312 return; 313 314 flags &= ~__GFP_ACCOUNT; 315 for (i = 0; i < size; i++) { 316 if (likely(p[i])) { 317 page = virt_to_head_page(p[i]); 318 319 if (!page_objcgs(page) && 320 memcg_alloc_page_obj_cgroups(page, s, flags)) { 321 obj_cgroup_uncharge(objcg, obj_full_size(s)); 322 continue; 323 } 324 325 off = obj_to_index(s, page, p[i]); 326 obj_cgroup_get(objcg); 327 page_objcgs(page)[off] = objcg; 328 mod_objcg_state(objcg, page_pgdat(page), 329 cache_vmstat_idx(s), obj_full_size(s)); 330 } else { 331 obj_cgroup_uncharge(objcg, obj_full_size(s)); 332 } 333 } 334 obj_cgroup_put(objcg); 335 } 336 337 static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, 338 void **p, int objects) 339 { 340 struct kmem_cache *s; 341 struct obj_cgroup **objcgs; 342 struct obj_cgroup *objcg; 343 struct page *page; 344 unsigned int off; 345 int i; 346 347 if (!memcg_kmem_enabled()) 348 return; 349 350 for (i = 0; i < objects; i++) { 351 if (unlikely(!p[i])) 352 continue; 353 354 page = virt_to_head_page(p[i]); 355 objcgs = page_objcgs(page); 356 if (!objcgs) 357 continue; 358 359 if (!s_orig) 360 s = page->slab_cache; 361 else 362 s = s_orig; 363 364 off = obj_to_index(s, page, p[i]); 365 objcg = objcgs[off]; 366 if (!objcg) 367 continue; 368 369 objcgs[off] = NULL; 370 obj_cgroup_uncharge(objcg, obj_full_size(s)); 371 mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s), 372 -obj_full_size(s)); 373 obj_cgroup_put(objcg); 374 } 375 } 376 377 #else /* CONFIG_MEMCG_KMEM */ 378 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) 379 { 380 return NULL; 381 } 382 383 static inline int memcg_alloc_page_obj_cgroups(struct page *page, 384 struct kmem_cache *s, gfp_t gfp) 385 { 386 return 0; 387 } 388 389 static inline void memcg_free_page_obj_cgroups(struct page *page) 390 { 391 } 392 393 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 394 struct obj_cgroup **objcgp, 395 size_t objects, gfp_t flags) 396 { 397 return true; 398 } 399 400 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 401 struct obj_cgroup *objcg, 402 gfp_t flags, size_t size, 403 void **p) 404 { 405 } 406 407 static inline void memcg_slab_free_hook(struct kmem_cache *s, 408 void **p, int objects) 409 { 410 } 411 #endif /* CONFIG_MEMCG_KMEM */ 412 413 static inline struct kmem_cache *virt_to_cache(const void *obj) 414 { 415 struct page *page; 416 417 page = virt_to_head_page(obj); 418 if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n", 419 __func__)) 420 return NULL; 421 return page->slab_cache; 422 } 423 424 static __always_inline void account_slab_page(struct page *page, int order, 425 struct kmem_cache *s) 426 { 427 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 428 PAGE_SIZE << order); 429 } 430 431 static __always_inline void unaccount_slab_page(struct page *page, int order, 432 struct kmem_cache *s) 433 { 434 if (memcg_kmem_enabled()) 435 memcg_free_page_obj_cgroups(page); 436 437 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 438 -(PAGE_SIZE << order)); 439 } 440 441 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) 442 { 443 struct kmem_cache *cachep; 444 445 if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && 446 !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) 447 return s; 448 449 cachep = virt_to_cache(x); 450 if (WARN(cachep && cachep != s, 451 "%s: Wrong slab cache. %s but object is from %s\n", 452 __func__, s->name, cachep->name)) 453 print_tracking(cachep, x); 454 return cachep; 455 } 456 457 static inline size_t slab_ksize(const struct kmem_cache *s) 458 { 459 #ifndef CONFIG_SLUB 460 return s->object_size; 461 462 #else /* CONFIG_SLUB */ 463 # ifdef CONFIG_SLUB_DEBUG 464 /* 465 * Debugging requires use of the padding between object 466 * and whatever may come after it. 467 */ 468 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) 469 return s->object_size; 470 # endif 471 if (s->flags & SLAB_KASAN) 472 return s->object_size; 473 /* 474 * If we have the need to store the freelist pointer 475 * back there or track user information then we can 476 * only use the space before that information. 477 */ 478 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER)) 479 return s->inuse; 480 /* 481 * Else we can use all the padding etc for the allocation 482 */ 483 return s->size; 484 #endif 485 } 486 487 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, 488 struct obj_cgroup **objcgp, 489 size_t size, gfp_t flags) 490 { 491 flags &= gfp_allowed_mask; 492 493 might_alloc(flags); 494 495 if (should_failslab(s, flags)) 496 return NULL; 497 498 if (!memcg_slab_pre_alloc_hook(s, objcgp, size, flags)) 499 return NULL; 500 501 return s; 502 } 503 504 static inline void slab_post_alloc_hook(struct kmem_cache *s, 505 struct obj_cgroup *objcg, 506 gfp_t flags, size_t size, void **p) 507 { 508 size_t i; 509 510 flags &= gfp_allowed_mask; 511 for (i = 0; i < size; i++) { 512 p[i] = kasan_slab_alloc(s, p[i], flags); 513 /* As p[i] might get tagged, call kmemleak hook after KASAN. */ 514 kmemleak_alloc_recursive(p[i], s->object_size, 1, 515 s->flags, flags); 516 } 517 518 memcg_slab_post_alloc_hook(s, objcg, flags, size, p); 519 } 520 521 #ifndef CONFIG_SLOB 522 /* 523 * The slab lists for all objects. 524 */ 525 struct kmem_cache_node { 526 spinlock_t list_lock; 527 528 #ifdef CONFIG_SLAB 529 struct list_head slabs_partial; /* partial list first, better asm code */ 530 struct list_head slabs_full; 531 struct list_head slabs_free; 532 unsigned long total_slabs; /* length of all slab lists */ 533 unsigned long free_slabs; /* length of free slab list only */ 534 unsigned long free_objects; 535 unsigned int free_limit; 536 unsigned int colour_next; /* Per-node cache coloring */ 537 struct array_cache *shared; /* shared per node */ 538 struct alien_cache **alien; /* on other nodes */ 539 unsigned long next_reap; /* updated without locking */ 540 int free_touched; /* updated without locking */ 541 #endif 542 543 #ifdef CONFIG_SLUB 544 unsigned long nr_partial; 545 struct list_head partial; 546 #ifdef CONFIG_SLUB_DEBUG 547 atomic_long_t nr_slabs; 548 atomic_long_t total_objects; 549 struct list_head full; 550 #endif 551 #endif 552 553 }; 554 555 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) 556 { 557 return s->node[node]; 558 } 559 560 /* 561 * Iterator over all nodes. The body will be executed for each node that has 562 * a kmem_cache_node structure allocated (which is true for all online nodes) 563 */ 564 #define for_each_kmem_cache_node(__s, __node, __n) \ 565 for (__node = 0; __node < nr_node_ids; __node++) \ 566 if ((__n = get_node(__s, __node))) 567 568 #endif 569 570 void *slab_start(struct seq_file *m, loff_t *pos); 571 void *slab_next(struct seq_file *m, void *p, loff_t *pos); 572 void slab_stop(struct seq_file *m, void *p); 573 int memcg_slab_show(struct seq_file *m, void *p); 574 575 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) 576 void dump_unreclaimable_slab(void); 577 #else 578 static inline void dump_unreclaimable_slab(void) 579 { 580 } 581 #endif 582 583 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr); 584 585 #ifdef CONFIG_SLAB_FREELIST_RANDOM 586 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, 587 gfp_t gfp); 588 void cache_random_seq_destroy(struct kmem_cache *cachep); 589 #else 590 static inline int cache_random_seq_create(struct kmem_cache *cachep, 591 unsigned int count, gfp_t gfp) 592 { 593 return 0; 594 } 595 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } 596 #endif /* CONFIG_SLAB_FREELIST_RANDOM */ 597 598 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) 599 { 600 if (static_branch_unlikely(&init_on_alloc)) { 601 if (c->ctor) 602 return false; 603 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) 604 return flags & __GFP_ZERO; 605 return true; 606 } 607 return flags & __GFP_ZERO; 608 } 609 610 static inline bool slab_want_init_on_free(struct kmem_cache *c) 611 { 612 if (static_branch_unlikely(&init_on_free)) 613 return !(c->ctor || 614 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); 615 return false; 616 } 617 618 #endif /* MM_SLAB_H */ 619