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 long validate_slab_cache(struct kmem_cache *s); 219 static inline bool __slub_debug_enabled(void) 220 { 221 return static_branch_unlikely(&slub_debug_enabled); 222 } 223 #else 224 static inline void print_tracking(struct kmem_cache *s, void *object) 225 { 226 } 227 static inline bool __slub_debug_enabled(void) 228 { 229 return false; 230 } 231 #endif 232 233 /* 234 * Returns true if any of the specified slub_debug flags is enabled for the 235 * cache. Use only for flags parsed by setup_slub_debug() as it also enables 236 * the static key. 237 */ 238 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags) 239 { 240 if (IS_ENABLED(CONFIG_SLUB_DEBUG)) 241 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS)); 242 if (__slub_debug_enabled()) 243 return s->flags & flags; 244 return false; 245 } 246 247 #ifdef CONFIG_MEMCG_KMEM 248 int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, 249 gfp_t gfp, bool new_page); 250 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, 251 enum node_stat_item idx, int nr); 252 253 static inline void memcg_free_page_obj_cgroups(struct page *page) 254 { 255 kfree(page_objcgs(page)); 256 page->memcg_data = 0; 257 } 258 259 static inline size_t obj_full_size(struct kmem_cache *s) 260 { 261 /* 262 * For each accounted object there is an extra space which is used 263 * to store obj_cgroup membership. Charge it too. 264 */ 265 return s->size + sizeof(struct obj_cgroup *); 266 } 267 268 /* 269 * Returns false if the allocation should fail. 270 */ 271 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 272 struct obj_cgroup **objcgp, 273 size_t objects, gfp_t flags) 274 { 275 struct obj_cgroup *objcg; 276 277 if (!memcg_kmem_enabled()) 278 return true; 279 280 if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)) 281 return true; 282 283 objcg = get_obj_cgroup_from_current(); 284 if (!objcg) 285 return true; 286 287 if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) { 288 obj_cgroup_put(objcg); 289 return false; 290 } 291 292 *objcgp = objcg; 293 return true; 294 } 295 296 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 297 struct obj_cgroup *objcg, 298 gfp_t flags, size_t size, 299 void **p) 300 { 301 struct page *page; 302 unsigned long off; 303 size_t i; 304 305 if (!memcg_kmem_enabled() || !objcg) 306 return; 307 308 for (i = 0; i < size; i++) { 309 if (likely(p[i])) { 310 page = virt_to_head_page(p[i]); 311 312 if (!page_objcgs(page) && 313 memcg_alloc_page_obj_cgroups(page, s, flags, 314 false)) { 315 obj_cgroup_uncharge(objcg, obj_full_size(s)); 316 continue; 317 } 318 319 off = obj_to_index(s, page, p[i]); 320 obj_cgroup_get(objcg); 321 page_objcgs(page)[off] = objcg; 322 mod_objcg_state(objcg, page_pgdat(page), 323 cache_vmstat_idx(s), obj_full_size(s)); 324 } else { 325 obj_cgroup_uncharge(objcg, obj_full_size(s)); 326 } 327 } 328 obj_cgroup_put(objcg); 329 } 330 331 static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, 332 void **p, int objects) 333 { 334 struct kmem_cache *s; 335 struct obj_cgroup **objcgs; 336 struct obj_cgroup *objcg; 337 struct page *page; 338 unsigned int off; 339 int i; 340 341 if (!memcg_kmem_enabled()) 342 return; 343 344 for (i = 0; i < objects; i++) { 345 if (unlikely(!p[i])) 346 continue; 347 348 page = virt_to_head_page(p[i]); 349 objcgs = page_objcgs_check(page); 350 if (!objcgs) 351 continue; 352 353 if (!s_orig) 354 s = page->slab_cache; 355 else 356 s = s_orig; 357 358 off = obj_to_index(s, page, p[i]); 359 objcg = objcgs[off]; 360 if (!objcg) 361 continue; 362 363 objcgs[off] = NULL; 364 obj_cgroup_uncharge(objcg, obj_full_size(s)); 365 mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s), 366 -obj_full_size(s)); 367 obj_cgroup_put(objcg); 368 } 369 } 370 371 #else /* CONFIG_MEMCG_KMEM */ 372 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) 373 { 374 return NULL; 375 } 376 377 static inline int memcg_alloc_page_obj_cgroups(struct page *page, 378 struct kmem_cache *s, gfp_t gfp, 379 bool new_page) 380 { 381 return 0; 382 } 383 384 static inline void memcg_free_page_obj_cgroups(struct page *page) 385 { 386 } 387 388 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, 389 struct obj_cgroup **objcgp, 390 size_t objects, gfp_t flags) 391 { 392 return true; 393 } 394 395 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, 396 struct obj_cgroup *objcg, 397 gfp_t flags, size_t size, 398 void **p) 399 { 400 } 401 402 static inline void memcg_slab_free_hook(struct kmem_cache *s, 403 void **p, int objects) 404 { 405 } 406 #endif /* CONFIG_MEMCG_KMEM */ 407 408 static inline struct kmem_cache *virt_to_cache(const void *obj) 409 { 410 struct page *page; 411 412 page = virt_to_head_page(obj); 413 if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n", 414 __func__)) 415 return NULL; 416 return page->slab_cache; 417 } 418 419 static __always_inline void account_slab_page(struct page *page, int order, 420 struct kmem_cache *s, 421 gfp_t gfp) 422 { 423 if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT)) 424 memcg_alloc_page_obj_cgroups(page, s, gfp, true); 425 426 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 427 PAGE_SIZE << order); 428 } 429 430 static __always_inline void unaccount_slab_page(struct page *page, int order, 431 struct kmem_cache *s) 432 { 433 if (memcg_kmem_enabled()) 434 memcg_free_page_obj_cgroups(page); 435 436 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 437 -(PAGE_SIZE << order)); 438 } 439 440 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) 441 { 442 struct kmem_cache *cachep; 443 444 if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && 445 !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) 446 return s; 447 448 cachep = virt_to_cache(x); 449 if (WARN(cachep && cachep != s, 450 "%s: Wrong slab cache. %s but object is from %s\n", 451 __func__, s->name, cachep->name)) 452 print_tracking(cachep, x); 453 return cachep; 454 } 455 456 static inline size_t slab_ksize(const struct kmem_cache *s) 457 { 458 #ifndef CONFIG_SLUB 459 return s->object_size; 460 461 #else /* CONFIG_SLUB */ 462 # ifdef CONFIG_SLUB_DEBUG 463 /* 464 * Debugging requires use of the padding between object 465 * and whatever may come after it. 466 */ 467 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) 468 return s->object_size; 469 # endif 470 if (s->flags & SLAB_KASAN) 471 return s->object_size; 472 /* 473 * If we have the need to store the freelist pointer 474 * back there or track user information then we can 475 * only use the space before that information. 476 */ 477 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER)) 478 return s->inuse; 479 /* 480 * Else we can use all the padding etc for the allocation 481 */ 482 return s->size; 483 #endif 484 } 485 486 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, 487 struct obj_cgroup **objcgp, 488 size_t size, gfp_t flags) 489 { 490 flags &= gfp_allowed_mask; 491 492 might_alloc(flags); 493 494 if (should_failslab(s, flags)) 495 return NULL; 496 497 if (!memcg_slab_pre_alloc_hook(s, objcgp, size, flags)) 498 return NULL; 499 500 return s; 501 } 502 503 static inline void slab_post_alloc_hook(struct kmem_cache *s, 504 struct obj_cgroup *objcg, gfp_t flags, 505 size_t size, void **p, bool init) 506 { 507 size_t i; 508 509 flags &= gfp_allowed_mask; 510 511 /* 512 * As memory initialization might be integrated into KASAN, 513 * kasan_slab_alloc and initialization memset must be 514 * kept together to avoid discrepancies in behavior. 515 * 516 * As p[i] might get tagged, memset and kmemleak hook come after KASAN. 517 */ 518 for (i = 0; i < size; i++) { 519 p[i] = kasan_slab_alloc(s, p[i], flags, init); 520 if (p[i] && init && !kasan_has_integrated_init()) 521 memset(p[i], 0, s->object_size); 522 kmemleak_alloc_recursive(p[i], s->object_size, 1, 523 s->flags, flags); 524 } 525 526 memcg_slab_post_alloc_hook(s, objcg, flags, size, p); 527 } 528 529 #ifndef CONFIG_SLOB 530 /* 531 * The slab lists for all objects. 532 */ 533 struct kmem_cache_node { 534 spinlock_t list_lock; 535 536 #ifdef CONFIG_SLAB 537 struct list_head slabs_partial; /* partial list first, better asm code */ 538 struct list_head slabs_full; 539 struct list_head slabs_free; 540 unsigned long total_slabs; /* length of all slab lists */ 541 unsigned long free_slabs; /* length of free slab list only */ 542 unsigned long free_objects; 543 unsigned int free_limit; 544 unsigned int colour_next; /* Per-node cache coloring */ 545 struct array_cache *shared; /* shared per node */ 546 struct alien_cache **alien; /* on other nodes */ 547 unsigned long next_reap; /* updated without locking */ 548 int free_touched; /* updated without locking */ 549 #endif 550 551 #ifdef CONFIG_SLUB 552 unsigned long nr_partial; 553 struct list_head partial; 554 #ifdef CONFIG_SLUB_DEBUG 555 atomic_long_t nr_slabs; 556 atomic_long_t total_objects; 557 struct list_head full; 558 #endif 559 #endif 560 561 }; 562 563 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) 564 { 565 return s->node[node]; 566 } 567 568 /* 569 * Iterator over all nodes. The body will be executed for each node that has 570 * a kmem_cache_node structure allocated (which is true for all online nodes) 571 */ 572 #define for_each_kmem_cache_node(__s, __node, __n) \ 573 for (__node = 0; __node < nr_node_ids; __node++) \ 574 if ((__n = get_node(__s, __node))) 575 576 #endif 577 578 void *slab_start(struct seq_file *m, loff_t *pos); 579 void *slab_next(struct seq_file *m, void *p, loff_t *pos); 580 void slab_stop(struct seq_file *m, void *p); 581 int memcg_slab_show(struct seq_file *m, void *p); 582 583 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) 584 void dump_unreclaimable_slab(void); 585 #else 586 static inline void dump_unreclaimable_slab(void) 587 { 588 } 589 #endif 590 591 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr); 592 593 #ifdef CONFIG_SLAB_FREELIST_RANDOM 594 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, 595 gfp_t gfp); 596 void cache_random_seq_destroy(struct kmem_cache *cachep); 597 #else 598 static inline int cache_random_seq_create(struct kmem_cache *cachep, 599 unsigned int count, gfp_t gfp) 600 { 601 return 0; 602 } 603 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } 604 #endif /* CONFIG_SLAB_FREELIST_RANDOM */ 605 606 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) 607 { 608 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, 609 &init_on_alloc)) { 610 if (c->ctor) 611 return false; 612 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) 613 return flags & __GFP_ZERO; 614 return true; 615 } 616 return flags & __GFP_ZERO; 617 } 618 619 static inline bool slab_want_init_on_free(struct kmem_cache *c) 620 { 621 if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, 622 &init_on_free)) 623 return !(c->ctor || 624 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); 625 return false; 626 } 627 628 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG) 629 void debugfs_slab_release(struct kmem_cache *); 630 #else 631 static inline void debugfs_slab_release(struct kmem_cache *s) { } 632 #endif 633 634 #ifdef CONFIG_PRINTK 635 #define KS_ADDRS_COUNT 16 636 struct kmem_obj_info { 637 void *kp_ptr; 638 struct page *kp_page; 639 void *kp_objp; 640 unsigned long kp_data_offset; 641 struct kmem_cache *kp_slab_cache; 642 void *kp_ret; 643 void *kp_stack[KS_ADDRS_COUNT]; 644 void *kp_free_stack[KS_ADDRS_COUNT]; 645 }; 646 void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page); 647 #endif 648 649 #endif /* MM_SLAB_H */ 650