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