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 #else /* !CONFIG_SLOB */ 34 35 struct memcg_cache_array { 36 struct rcu_head rcu; 37 struct kmem_cache *entries[0]; 38 }; 39 40 /* 41 * This is the main placeholder for memcg-related information in kmem caches. 42 * Both the root cache and the child caches will have it. For the root cache, 43 * this will hold a dynamically allocated array large enough to hold 44 * information about the currently limited memcgs in the system. To allow the 45 * array to be accessed without taking any locks, on relocation we free the old 46 * version only after a grace period. 47 * 48 * Root and child caches hold different metadata. 49 * 50 * @root_cache: Common to root and child caches. NULL for root, pointer to 51 * the root cache for children. 52 * 53 * The following fields are specific to root caches. 54 * 55 * @memcg_caches: kmemcg ID indexed table of child caches. This table is 56 * used to index child cachces during allocation and cleared 57 * early during shutdown. 58 * 59 * @root_caches_node: List node for slab_root_caches list. 60 * 61 * @children: List of all child caches. While the child caches are also 62 * reachable through @memcg_caches, a child cache remains on 63 * this list until it is actually destroyed. 64 * 65 * The following fields are specific to child caches. 66 * 67 * @memcg: Pointer to the memcg this cache belongs to. 68 * 69 * @children_node: List node for @root_cache->children list. 70 * 71 * @kmem_caches_node: List node for @memcg->kmem_caches list. 72 */ 73 struct memcg_cache_params { 74 struct kmem_cache *root_cache; 75 union { 76 struct { 77 struct memcg_cache_array __rcu *memcg_caches; 78 struct list_head __root_caches_node; 79 struct list_head children; 80 bool dying; 81 }; 82 struct { 83 struct mem_cgroup *memcg; 84 struct list_head children_node; 85 struct list_head kmem_caches_node; 86 struct percpu_ref refcnt; 87 88 void (*work_fn)(struct kmem_cache *); 89 union { 90 struct rcu_head rcu_head; 91 struct work_struct work; 92 }; 93 }; 94 }; 95 }; 96 #endif /* CONFIG_SLOB */ 97 98 #ifdef CONFIG_SLAB 99 #include <linux/slab_def.h> 100 #endif 101 102 #ifdef CONFIG_SLUB 103 #include <linux/slub_def.h> 104 #endif 105 106 #include <linux/memcontrol.h> 107 #include <linux/fault-inject.h> 108 #include <linux/kasan.h> 109 #include <linux/kmemleak.h> 110 #include <linux/random.h> 111 #include <linux/sched/mm.h> 112 113 /* 114 * State of the slab allocator. 115 * 116 * This is used to describe the states of the allocator during bootup. 117 * Allocators use this to gradually bootstrap themselves. Most allocators 118 * have the problem that the structures used for managing slab caches are 119 * allocated from slab caches themselves. 120 */ 121 enum slab_state { 122 DOWN, /* No slab functionality yet */ 123 PARTIAL, /* SLUB: kmem_cache_node available */ 124 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */ 125 UP, /* Slab caches usable but not all extras yet */ 126 FULL /* Everything is working */ 127 }; 128 129 extern enum slab_state slab_state; 130 131 /* The slab cache mutex protects the management structures during changes */ 132 extern struct mutex slab_mutex; 133 134 /* The list of all slab caches on the system */ 135 extern struct list_head slab_caches; 136 137 /* The slab cache that manages slab cache information */ 138 extern struct kmem_cache *kmem_cache; 139 140 /* A table of kmalloc cache names and sizes */ 141 extern const struct kmalloc_info_struct { 142 const char *name[NR_KMALLOC_TYPES]; 143 unsigned int size; 144 } kmalloc_info[]; 145 146 #ifndef CONFIG_SLOB 147 /* Kmalloc array related functions */ 148 void setup_kmalloc_cache_index_table(void); 149 void create_kmalloc_caches(slab_flags_t); 150 151 /* Find the kmalloc slab corresponding for a certain size */ 152 struct kmem_cache *kmalloc_slab(size_t, gfp_t); 153 #endif 154 155 156 /* Functions provided by the slab allocators */ 157 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); 158 159 struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size, 160 slab_flags_t flags, unsigned int useroffset, 161 unsigned int usersize); 162 extern void create_boot_cache(struct kmem_cache *, const char *name, 163 unsigned int size, slab_flags_t flags, 164 unsigned int useroffset, unsigned int usersize); 165 166 int slab_unmergeable(struct kmem_cache *s); 167 struct kmem_cache *find_mergeable(unsigned size, unsigned align, 168 slab_flags_t flags, const char *name, void (*ctor)(void *)); 169 #ifndef CONFIG_SLOB 170 struct kmem_cache * 171 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, 172 slab_flags_t flags, void (*ctor)(void *)); 173 174 slab_flags_t kmem_cache_flags(unsigned int object_size, 175 slab_flags_t flags, const char *name, 176 void (*ctor)(void *)); 177 #else 178 static inline struct kmem_cache * 179 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, 180 slab_flags_t flags, void (*ctor)(void *)) 181 { return NULL; } 182 183 static inline slab_flags_t kmem_cache_flags(unsigned int object_size, 184 slab_flags_t flags, const char *name, 185 void (*ctor)(void *)) 186 { 187 return flags; 188 } 189 #endif 190 191 192 /* Legal flag mask for kmem_cache_create(), for various configurations */ 193 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \ 194 SLAB_CACHE_DMA32 | SLAB_PANIC | \ 195 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS ) 196 197 #if defined(CONFIG_DEBUG_SLAB) 198 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) 199 #elif defined(CONFIG_SLUB_DEBUG) 200 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ 201 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS) 202 #else 203 #define SLAB_DEBUG_FLAGS (0) 204 #endif 205 206 #if defined(CONFIG_SLAB) 207 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \ 208 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \ 209 SLAB_ACCOUNT) 210 #elif defined(CONFIG_SLUB) 211 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ 212 SLAB_TEMPORARY | SLAB_ACCOUNT) 213 #else 214 #define SLAB_CACHE_FLAGS (0) 215 #endif 216 217 /* Common flags available with current configuration */ 218 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) 219 220 /* Common flags permitted for kmem_cache_create */ 221 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \ 222 SLAB_RED_ZONE | \ 223 SLAB_POISON | \ 224 SLAB_STORE_USER | \ 225 SLAB_TRACE | \ 226 SLAB_CONSISTENCY_CHECKS | \ 227 SLAB_MEM_SPREAD | \ 228 SLAB_NOLEAKTRACE | \ 229 SLAB_RECLAIM_ACCOUNT | \ 230 SLAB_TEMPORARY | \ 231 SLAB_ACCOUNT) 232 233 bool __kmem_cache_empty(struct kmem_cache *); 234 int __kmem_cache_shutdown(struct kmem_cache *); 235 void __kmem_cache_release(struct kmem_cache *); 236 int __kmem_cache_shrink(struct kmem_cache *); 237 void __kmemcg_cache_deactivate(struct kmem_cache *s); 238 void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s); 239 void slab_kmem_cache_release(struct kmem_cache *); 240 void kmem_cache_shrink_all(struct kmem_cache *s); 241 242 struct seq_file; 243 struct file; 244 245 struct slabinfo { 246 unsigned long active_objs; 247 unsigned long num_objs; 248 unsigned long active_slabs; 249 unsigned long num_slabs; 250 unsigned long shared_avail; 251 unsigned int limit; 252 unsigned int batchcount; 253 unsigned int shared; 254 unsigned int objects_per_slab; 255 unsigned int cache_order; 256 }; 257 258 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo); 259 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s); 260 ssize_t slabinfo_write(struct file *file, const char __user *buffer, 261 size_t count, loff_t *ppos); 262 263 /* 264 * Generic implementation of bulk operations 265 * These are useful for situations in which the allocator cannot 266 * perform optimizations. In that case segments of the object listed 267 * may be allocated or freed using these operations. 268 */ 269 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); 270 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); 271 272 static inline int cache_vmstat_idx(struct kmem_cache *s) 273 { 274 return (s->flags & SLAB_RECLAIM_ACCOUNT) ? 275 NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE; 276 } 277 278 #ifdef CONFIG_MEMCG_KMEM 279 280 /* List of all root caches. */ 281 extern struct list_head slab_root_caches; 282 #define root_caches_node memcg_params.__root_caches_node 283 284 /* 285 * Iterate over all memcg caches of the given root cache. The caller must hold 286 * slab_mutex. 287 */ 288 #define for_each_memcg_cache(iter, root) \ 289 list_for_each_entry(iter, &(root)->memcg_params.children, \ 290 memcg_params.children_node) 291 292 static inline bool is_root_cache(struct kmem_cache *s) 293 { 294 return !s->memcg_params.root_cache; 295 } 296 297 static inline bool slab_equal_or_root(struct kmem_cache *s, 298 struct kmem_cache *p) 299 { 300 return p == s || p == s->memcg_params.root_cache; 301 } 302 303 /* 304 * We use suffixes to the name in memcg because we can't have caches 305 * created in the system with the same name. But when we print them 306 * locally, better refer to them with the base name 307 */ 308 static inline const char *cache_name(struct kmem_cache *s) 309 { 310 if (!is_root_cache(s)) 311 s = s->memcg_params.root_cache; 312 return s->name; 313 } 314 315 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) 316 { 317 if (is_root_cache(s)) 318 return s; 319 return s->memcg_params.root_cache; 320 } 321 322 /* 323 * Expects a pointer to a slab page. Please note, that PageSlab() check 324 * isn't sufficient, as it returns true also for tail compound slab pages, 325 * which do not have slab_cache pointer set. 326 * So this function assumes that the page can pass PageSlab() && !PageTail() 327 * check. 328 * 329 * The kmem_cache can be reparented asynchronously. The caller must ensure 330 * the memcg lifetime, e.g. by taking rcu_read_lock() or cgroup_mutex. 331 */ 332 static inline struct mem_cgroup *memcg_from_slab_page(struct page *page) 333 { 334 struct kmem_cache *s; 335 336 s = READ_ONCE(page->slab_cache); 337 if (s && !is_root_cache(s)) 338 return READ_ONCE(s->memcg_params.memcg); 339 340 return NULL; 341 } 342 343 /* 344 * Charge the slab page belonging to the non-root kmem_cache. 345 * Can be called for non-root kmem_caches only. 346 */ 347 static __always_inline int memcg_charge_slab(struct page *page, 348 gfp_t gfp, int order, 349 struct kmem_cache *s) 350 { 351 unsigned int nr_pages = 1 << order; 352 struct mem_cgroup *memcg; 353 struct lruvec *lruvec; 354 int ret; 355 356 rcu_read_lock(); 357 memcg = READ_ONCE(s->memcg_params.memcg); 358 while (memcg && !css_tryget_online(&memcg->css)) 359 memcg = parent_mem_cgroup(memcg); 360 rcu_read_unlock(); 361 362 if (unlikely(!memcg || mem_cgroup_is_root(memcg))) { 363 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 364 nr_pages); 365 percpu_ref_get_many(&s->memcg_params.refcnt, nr_pages); 366 return 0; 367 } 368 369 ret = memcg_kmem_charge(memcg, gfp, nr_pages); 370 if (ret) 371 goto out; 372 373 lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page)); 374 mod_lruvec_state(lruvec, cache_vmstat_idx(s), nr_pages); 375 376 /* transer try_charge() page references to kmem_cache */ 377 percpu_ref_get_many(&s->memcg_params.refcnt, nr_pages); 378 css_put_many(&memcg->css, nr_pages); 379 out: 380 css_put(&memcg->css); 381 return ret; 382 } 383 384 /* 385 * Uncharge a slab page belonging to a non-root kmem_cache. 386 * Can be called for non-root kmem_caches only. 387 */ 388 static __always_inline void memcg_uncharge_slab(struct page *page, int order, 389 struct kmem_cache *s) 390 { 391 unsigned int nr_pages = 1 << order; 392 struct mem_cgroup *memcg; 393 struct lruvec *lruvec; 394 395 rcu_read_lock(); 396 memcg = READ_ONCE(s->memcg_params.memcg); 397 if (likely(!mem_cgroup_is_root(memcg))) { 398 lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page)); 399 mod_lruvec_state(lruvec, cache_vmstat_idx(s), -nr_pages); 400 memcg_kmem_uncharge(memcg, nr_pages); 401 } else { 402 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 403 -nr_pages); 404 } 405 rcu_read_unlock(); 406 407 percpu_ref_put_many(&s->memcg_params.refcnt, nr_pages); 408 } 409 410 extern void slab_init_memcg_params(struct kmem_cache *); 411 extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg); 412 413 #else /* CONFIG_MEMCG_KMEM */ 414 415 /* If !memcg, all caches are root. */ 416 #define slab_root_caches slab_caches 417 #define root_caches_node list 418 419 #define for_each_memcg_cache(iter, root) \ 420 for ((void)(iter), (void)(root); 0; ) 421 422 static inline bool is_root_cache(struct kmem_cache *s) 423 { 424 return true; 425 } 426 427 static inline bool slab_equal_or_root(struct kmem_cache *s, 428 struct kmem_cache *p) 429 { 430 return s == p; 431 } 432 433 static inline const char *cache_name(struct kmem_cache *s) 434 { 435 return s->name; 436 } 437 438 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) 439 { 440 return s; 441 } 442 443 static inline struct mem_cgroup *memcg_from_slab_page(struct page *page) 444 { 445 return NULL; 446 } 447 448 static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order, 449 struct kmem_cache *s) 450 { 451 return 0; 452 } 453 454 static inline void memcg_uncharge_slab(struct page *page, int order, 455 struct kmem_cache *s) 456 { 457 } 458 459 static inline void slab_init_memcg_params(struct kmem_cache *s) 460 { 461 } 462 463 static inline void memcg_link_cache(struct kmem_cache *s, 464 struct mem_cgroup *memcg) 465 { 466 } 467 468 #endif /* CONFIG_MEMCG_KMEM */ 469 470 static inline struct kmem_cache *virt_to_cache(const void *obj) 471 { 472 struct page *page; 473 474 page = virt_to_head_page(obj); 475 if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n", 476 __func__)) 477 return NULL; 478 return page->slab_cache; 479 } 480 481 static __always_inline int charge_slab_page(struct page *page, 482 gfp_t gfp, int order, 483 struct kmem_cache *s) 484 { 485 if (is_root_cache(s)) { 486 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 487 1 << order); 488 return 0; 489 } 490 491 return memcg_charge_slab(page, gfp, order, s); 492 } 493 494 static __always_inline void uncharge_slab_page(struct page *page, int order, 495 struct kmem_cache *s) 496 { 497 if (is_root_cache(s)) { 498 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 499 -(1 << order)); 500 return; 501 } 502 503 memcg_uncharge_slab(page, order, s); 504 } 505 506 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) 507 { 508 struct kmem_cache *cachep; 509 510 /* 511 * When kmemcg is not being used, both assignments should return the 512 * same value. but we don't want to pay the assignment price in that 513 * case. If it is not compiled in, the compiler should be smart enough 514 * to not do even the assignment. In that case, slab_equal_or_root 515 * will also be a constant. 516 */ 517 if (!memcg_kmem_enabled() && 518 !IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && 519 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS)) 520 return s; 521 522 cachep = virt_to_cache(x); 523 WARN_ONCE(cachep && !slab_equal_or_root(cachep, s), 524 "%s: Wrong slab cache. %s but object is from %s\n", 525 __func__, s->name, cachep->name); 526 return cachep; 527 } 528 529 static inline size_t slab_ksize(const struct kmem_cache *s) 530 { 531 #ifndef CONFIG_SLUB 532 return s->object_size; 533 534 #else /* CONFIG_SLUB */ 535 # ifdef CONFIG_SLUB_DEBUG 536 /* 537 * Debugging requires use of the padding between object 538 * and whatever may come after it. 539 */ 540 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) 541 return s->object_size; 542 # endif 543 if (s->flags & SLAB_KASAN) 544 return s->object_size; 545 /* 546 * If we have the need to store the freelist pointer 547 * back there or track user information then we can 548 * only use the space before that information. 549 */ 550 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER)) 551 return s->inuse; 552 /* 553 * Else we can use all the padding etc for the allocation 554 */ 555 return s->size; 556 #endif 557 } 558 559 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, 560 gfp_t flags) 561 { 562 flags &= gfp_allowed_mask; 563 564 fs_reclaim_acquire(flags); 565 fs_reclaim_release(flags); 566 567 might_sleep_if(gfpflags_allow_blocking(flags)); 568 569 if (should_failslab(s, flags)) 570 return NULL; 571 572 if (memcg_kmem_enabled() && 573 ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT))) 574 return memcg_kmem_get_cache(s); 575 576 return s; 577 } 578 579 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, 580 size_t size, void **p) 581 { 582 size_t i; 583 584 flags &= gfp_allowed_mask; 585 for (i = 0; i < size; i++) { 586 p[i] = kasan_slab_alloc(s, p[i], flags); 587 /* As p[i] might get tagged, call kmemleak hook after KASAN. */ 588 kmemleak_alloc_recursive(p[i], s->object_size, 1, 589 s->flags, flags); 590 } 591 592 if (memcg_kmem_enabled()) 593 memcg_kmem_put_cache(s); 594 } 595 596 #ifndef CONFIG_SLOB 597 /* 598 * The slab lists for all objects. 599 */ 600 struct kmem_cache_node { 601 spinlock_t list_lock; 602 603 #ifdef CONFIG_SLAB 604 struct list_head slabs_partial; /* partial list first, better asm code */ 605 struct list_head slabs_full; 606 struct list_head slabs_free; 607 unsigned long total_slabs; /* length of all slab lists */ 608 unsigned long free_slabs; /* length of free slab list only */ 609 unsigned long free_objects; 610 unsigned int free_limit; 611 unsigned int colour_next; /* Per-node cache coloring */ 612 struct array_cache *shared; /* shared per node */ 613 struct alien_cache **alien; /* on other nodes */ 614 unsigned long next_reap; /* updated without locking */ 615 int free_touched; /* updated without locking */ 616 #endif 617 618 #ifdef CONFIG_SLUB 619 unsigned long nr_partial; 620 struct list_head partial; 621 #ifdef CONFIG_SLUB_DEBUG 622 atomic_long_t nr_slabs; 623 atomic_long_t total_objects; 624 struct list_head full; 625 #endif 626 #endif 627 628 }; 629 630 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) 631 { 632 return s->node[node]; 633 } 634 635 /* 636 * Iterator over all nodes. The body will be executed for each node that has 637 * a kmem_cache_node structure allocated (which is true for all online nodes) 638 */ 639 #define for_each_kmem_cache_node(__s, __node, __n) \ 640 for (__node = 0; __node < nr_node_ids; __node++) \ 641 if ((__n = get_node(__s, __node))) 642 643 #endif 644 645 void *slab_start(struct seq_file *m, loff_t *pos); 646 void *slab_next(struct seq_file *m, void *p, loff_t *pos); 647 void slab_stop(struct seq_file *m, void *p); 648 void *memcg_slab_start(struct seq_file *m, loff_t *pos); 649 void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos); 650 void memcg_slab_stop(struct seq_file *m, void *p); 651 int memcg_slab_show(struct seq_file *m, void *p); 652 653 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) 654 void dump_unreclaimable_slab(void); 655 #else 656 static inline void dump_unreclaimable_slab(void) 657 { 658 } 659 #endif 660 661 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr); 662 663 #ifdef CONFIG_SLAB_FREELIST_RANDOM 664 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, 665 gfp_t gfp); 666 void cache_random_seq_destroy(struct kmem_cache *cachep); 667 #else 668 static inline int cache_random_seq_create(struct kmem_cache *cachep, 669 unsigned int count, gfp_t gfp) 670 { 671 return 0; 672 } 673 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } 674 #endif /* CONFIG_SLAB_FREELIST_RANDOM */ 675 676 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) 677 { 678 if (static_branch_unlikely(&init_on_alloc)) { 679 if (c->ctor) 680 return false; 681 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) 682 return flags & __GFP_ZERO; 683 return true; 684 } 685 return flags & __GFP_ZERO; 686 } 687 688 static inline bool slab_want_init_on_free(struct kmem_cache *c) 689 { 690 if (static_branch_unlikely(&init_on_free)) 691 return !(c->ctor || 692 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); 693 return false; 694 } 695 696 #endif /* MM_SLAB_H */ 697