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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 */
20struct 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
35struct 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 */
73struct 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 */
121enum 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
129extern enum slab_state slab_state;
130
131/* The slab cache mutex protects the management structures during changes */
132extern struct mutex slab_mutex;
133
134/* The list of all slab caches on the system */
135extern struct list_head slab_caches;
136
137/* The slab cache that manages slab cache information */
138extern struct kmem_cache *kmem_cache;
139
140/* A table of kmalloc cache names and sizes */
141extern const struct kmalloc_info_struct {
142 const char *name;
143 unsigned int size;
144} kmalloc_info[];
145
146#ifndef CONFIG_SLOB
147/* Kmalloc array related functions */
148void setup_kmalloc_cache_index_table(void);
149void create_kmalloc_caches(slab_flags_t);
150
151/* Find the kmalloc slab corresponding for a certain size */
152struct kmem_cache *kmalloc_slab(size_t, gfp_t);
153#endif
154
155
156/* Functions provided by the slab allocators */
157int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
158
159struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
160 slab_flags_t flags, unsigned int useroffset,
161 unsigned int usersize);
162extern 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
166int slab_unmergeable(struct kmem_cache *s);
167struct kmem_cache *find_mergeable(unsigned size, unsigned align,
168 slab_flags_t flags, const char *name, void (*ctor)(void *));
169#ifndef CONFIG_SLOB
170struct kmem_cache *
171__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
172 slab_flags_t flags, void (*ctor)(void *));
173
174slab_flags_t kmem_cache_flags(unsigned int object_size,
175 slab_flags_t flags, const char *name,
176 void (*ctor)(void *));
177#else
178static 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
183static 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
233bool __kmem_cache_empty(struct kmem_cache *);
234int __kmem_cache_shutdown(struct kmem_cache *);
235void __kmem_cache_release(struct kmem_cache *);
236int __kmem_cache_shrink(struct kmem_cache *);
237void __kmemcg_cache_deactivate(struct kmem_cache *s);
238void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s);
239void slab_kmem_cache_release(struct kmem_cache *);
240void kmem_cache_shrink_all(struct kmem_cache *s);
241
242struct seq_file;
243struct file;
244
245struct 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
258void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
259void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
260ssize_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 */
269void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
270int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
271
272static 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. */
281extern 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
292static inline bool is_root_cache(struct kmem_cache *s)
293{
294 return !s->memcg_params.root_cache;
295}
296
297static 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 */
308static 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
315static 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 */
332static 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 */
347static __always_inline int memcg_charge_slab(struct page *page,
348 gfp_t gfp, int order,
349 struct kmem_cache *s)
350{
351 struct mem_cgroup *memcg;
352 struct lruvec *lruvec;
353 int ret;
354
355 rcu_read_lock();
356 memcg = READ_ONCE(s->memcg_params.memcg);
357 while (memcg && !css_tryget_online(&memcg->css))
358 memcg = parent_mem_cgroup(memcg);
359 rcu_read_unlock();
360
361 if (unlikely(!memcg || mem_cgroup_is_root(memcg))) {
362 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
363 (1 << order));
364 percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);
365 return 0;
366 }
367
368 ret = memcg_kmem_charge_memcg(page, gfp, order, memcg);
369 if (ret)
370 goto out;
371
372 lruvec = mem_cgroup_lruvec(page_pgdat(page), memcg);
373 mod_lruvec_state(lruvec, cache_vmstat_idx(s), 1 << order);
374
375 /* transer try_charge() page references to kmem_cache */
376 percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);
377 css_put_many(&memcg->css, 1 << order);
378out:
379 css_put(&memcg->css);
380 return ret;
381}
382
383/*
384 * Uncharge a slab page belonging to a non-root kmem_cache.
385 * Can be called for non-root kmem_caches only.
386 */
387static __always_inline void memcg_uncharge_slab(struct page *page, int order,
388 struct kmem_cache *s)
389{
390 struct mem_cgroup *memcg;
391 struct lruvec *lruvec;
392
393 rcu_read_lock();
394 memcg = READ_ONCE(s->memcg_params.memcg);
395 if (likely(!mem_cgroup_is_root(memcg))) {
396 lruvec = mem_cgroup_lruvec(page_pgdat(page), memcg);
397 mod_lruvec_state(lruvec, cache_vmstat_idx(s), -(1 << order));
398 memcg_kmem_uncharge_memcg(page, order, memcg);
399 } else {
400 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
401 -(1 << order));
402 }
403 rcu_read_unlock();
404
405 percpu_ref_put_many(&s->memcg_params.refcnt, 1 << order);
406}
407
408extern void slab_init_memcg_params(struct kmem_cache *);
409extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);
410
411#else /* CONFIG_MEMCG_KMEM */
412
413/* If !memcg, all caches are root. */
414#define slab_root_caches slab_caches
415#define root_caches_node list
416
417#define for_each_memcg_cache(iter, root) \
418 for ((void)(iter), (void)(root); 0; )
419
420static inline bool is_root_cache(struct kmem_cache *s)
421{
422 return true;
423}
424
425static inline bool slab_equal_or_root(struct kmem_cache *s,
426 struct kmem_cache *p)
427{
428 return s == p;
429}
430
431static inline const char *cache_name(struct kmem_cache *s)
432{
433 return s->name;
434}
435
436static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
437{
438 return s;
439}
440
441static inline struct mem_cgroup *memcg_from_slab_page(struct page *page)
442{
443 return NULL;
444}
445
446static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
447 struct kmem_cache *s)
448{
449 return 0;
450}
451
452static inline void memcg_uncharge_slab(struct page *page, int order,
453 struct kmem_cache *s)
454{
455}
456
457static inline void slab_init_memcg_params(struct kmem_cache *s)
458{
459}
460
461static inline void memcg_link_cache(struct kmem_cache *s,
462 struct mem_cgroup *memcg)
463{
464}
465
466#endif /* CONFIG_MEMCG_KMEM */
467
468static inline struct kmem_cache *virt_to_cache(const void *obj)
469{
470 struct page *page;
471
472 page = virt_to_head_page(obj);
473 if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n",
474 __func__))
475 return NULL;
476 return page->slab_cache;
477}
478
479static __always_inline int charge_slab_page(struct page *page,
480 gfp_t gfp, int order,
481 struct kmem_cache *s)
482{
483 if (is_root_cache(s)) {
484 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
485 1 << order);
486 return 0;
487 }
488
489 return memcg_charge_slab(page, gfp, order, s);
490}
491
492static __always_inline void uncharge_slab_page(struct page *page, int order,
493 struct kmem_cache *s)
494{
495 if (is_root_cache(s)) {
496 mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
497 -(1 << order));
498 return;
499 }
500
501 memcg_uncharge_slab(page, order, s);
502}
503
504static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
505{
506 struct kmem_cache *cachep;
507
508 /*
509 * When kmemcg is not being used, both assignments should return the
510 * same value. but we don't want to pay the assignment price in that
511 * case. If it is not compiled in, the compiler should be smart enough
512 * to not do even the assignment. In that case, slab_equal_or_root
513 * will also be a constant.
514 */
515 if (!memcg_kmem_enabled() &&
516 !IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
517 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
518 return s;
519
520 cachep = virt_to_cache(x);
521 WARN_ONCE(cachep && !slab_equal_or_root(cachep, s),
522 "%s: Wrong slab cache. %s but object is from %s\n",
523 __func__, s->name, cachep->name);
524 return cachep;
525}
526
527static inline size_t slab_ksize(const struct kmem_cache *s)
528{
529#ifndef CONFIG_SLUB
530 return s->object_size;
531
532#else /* CONFIG_SLUB */
533# ifdef CONFIG_SLUB_DEBUG
534 /*
535 * Debugging requires use of the padding between object
536 * and whatever may come after it.
537 */
538 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
539 return s->object_size;
540# endif
541 if (s->flags & SLAB_KASAN)
542 return s->object_size;
543 /*
544 * If we have the need to store the freelist pointer
545 * back there or track user information then we can
546 * only use the space before that information.
547 */
548 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
549 return s->inuse;
550 /*
551 * Else we can use all the padding etc for the allocation
552 */
553 return s->size;
554#endif
555}
556
557static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
558 gfp_t flags)
559{
560 flags &= gfp_allowed_mask;
561
562 fs_reclaim_acquire(flags);
563 fs_reclaim_release(flags);
564
565 might_sleep_if(gfpflags_allow_blocking(flags));
566
567 if (should_failslab(s, flags))
568 return NULL;
569
570 if (memcg_kmem_enabled() &&
571 ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
572 return memcg_kmem_get_cache(s);
573
574 return s;
575}
576
577static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
578 size_t size, void **p)
579{
580 size_t i;
581
582 flags &= gfp_allowed_mask;
583 for (i = 0; i < size; i++) {
584 p[i] = kasan_slab_alloc(s, p[i], flags);
585 /* As p[i] might get tagged, call kmemleak hook after KASAN. */
586 kmemleak_alloc_recursive(p[i], s->object_size, 1,
587 s->flags, flags);
588 }
589
590 if (memcg_kmem_enabled())
591 memcg_kmem_put_cache(s);
592}
593
594#ifndef CONFIG_SLOB
595/*
596 * The slab lists for all objects.
597 */
598struct kmem_cache_node {
599 spinlock_t list_lock;
600
601#ifdef CONFIG_SLAB
602 struct list_head slabs_partial; /* partial list first, better asm code */
603 struct list_head slabs_full;
604 struct list_head slabs_free;
605 unsigned long total_slabs; /* length of all slab lists */
606 unsigned long free_slabs; /* length of free slab list only */
607 unsigned long free_objects;
608 unsigned int free_limit;
609 unsigned int colour_next; /* Per-node cache coloring */
610 struct array_cache *shared; /* shared per node */
611 struct alien_cache **alien; /* on other nodes */
612 unsigned long next_reap; /* updated without locking */
613 int free_touched; /* updated without locking */
614#endif
615
616#ifdef CONFIG_SLUB
617 unsigned long nr_partial;
618 struct list_head partial;
619#ifdef CONFIG_SLUB_DEBUG
620 atomic_long_t nr_slabs;
621 atomic_long_t total_objects;
622 struct list_head full;
623#endif
624#endif
625
626};
627
628static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
629{
630 return s->node[node];
631}
632
633/*
634 * Iterator over all nodes. The body will be executed for each node that has
635 * a kmem_cache_node structure allocated (which is true for all online nodes)
636 */
637#define for_each_kmem_cache_node(__s, __node, __n) \
638 for (__node = 0; __node < nr_node_ids; __node++) \
639 if ((__n = get_node(__s, __node)))
640
641#endif
642
643void *slab_start(struct seq_file *m, loff_t *pos);
644void *slab_next(struct seq_file *m, void *p, loff_t *pos);
645void slab_stop(struct seq_file *m, void *p);
646void *memcg_slab_start(struct seq_file *m, loff_t *pos);
647void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
648void memcg_slab_stop(struct seq_file *m, void *p);
649int memcg_slab_show(struct seq_file *m, void *p);
650
651#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
652void dump_unreclaimable_slab(void);
653#else
654static inline void dump_unreclaimable_slab(void)
655{
656}
657#endif
658
659void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
660
661#ifdef CONFIG_SLAB_FREELIST_RANDOM
662int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
663 gfp_t gfp);
664void cache_random_seq_destroy(struct kmem_cache *cachep);
665#else
666static inline int cache_random_seq_create(struct kmem_cache *cachep,
667 unsigned int count, gfp_t gfp)
668{
669 return 0;
670}
671static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
672#endif /* CONFIG_SLAB_FREELIST_RANDOM */
673
674static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
675{
676 if (static_branch_unlikely(&init_on_alloc)) {
677 if (c->ctor)
678 return false;
679 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
680 return flags & __GFP_ZERO;
681 return true;
682 }
683 return flags & __GFP_ZERO;
684}
685
686static inline bool slab_want_init_on_free(struct kmem_cache *c)
687{
688 if (static_branch_unlikely(&init_on_free))
689 return !(c->ctor ||
690 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
691 return false;
692}
693
694#endif /* MM_SLAB_H */
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 */
20struct 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 */
58enum 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
66extern enum slab_state slab_state;
67
68/* The slab cache mutex protects the management structures during changes */
69extern struct mutex slab_mutex;
70
71/* The list of all slab caches on the system */
72extern struct list_head slab_caches;
73
74/* The slab cache that manages slab cache information */
75extern struct kmem_cache *kmem_cache;
76
77/* A table of kmalloc cache names and sizes */
78extern const struct kmalloc_info_struct {
79 const char *name;
80 unsigned int size;
81} kmalloc_info[];
82
83#ifndef CONFIG_SLOB
84/* Kmalloc array related functions */
85void setup_kmalloc_cache_index_table(void);
86void create_kmalloc_caches(slab_flags_t);
87
88/* Find the kmalloc slab corresponding for a certain size */
89struct kmem_cache *kmalloc_slab(size_t, gfp_t);
90#endif
91
92
93/* Functions provided by the slab allocators */
94int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
95
96struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
97 slab_flags_t flags, unsigned int useroffset,
98 unsigned int usersize);
99extern void create_boot_cache(struct kmem_cache *, const char *name,
100 unsigned int size, slab_flags_t flags,
101 unsigned int useroffset, unsigned int usersize);
102
103int slab_unmergeable(struct kmem_cache *s);
104struct kmem_cache *find_mergeable(unsigned size, unsigned align,
105 slab_flags_t flags, const char *name, void (*ctor)(void *));
106#ifndef CONFIG_SLOB
107struct kmem_cache *
108__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
109 slab_flags_t flags, void (*ctor)(void *));
110
111slab_flags_t kmem_cache_flags(unsigned int object_size,
112 slab_flags_t flags, const char *name,
113 void (*ctor)(void *));
114#else
115static 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
120static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
121 slab_flags_t flags, const char *name,
122 void (*ctor)(void *))
123{
124 return flags;
125}
126#endif
127
128
129/* Legal flag mask for kmem_cache_create(), for various configurations */
130#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | 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
169bool __kmem_cache_empty(struct kmem_cache *);
170int __kmem_cache_shutdown(struct kmem_cache *);
171void __kmem_cache_release(struct kmem_cache *);
172int __kmem_cache_shrink(struct kmem_cache *);
173void __kmemcg_cache_deactivate(struct kmem_cache *s);
174void slab_kmem_cache_release(struct kmem_cache *);
175
176struct seq_file;
177struct file;
178
179struct slabinfo {
180 unsigned long active_objs;
181 unsigned long num_objs;
182 unsigned long active_slabs;
183 unsigned long num_slabs;
184 unsigned long shared_avail;
185 unsigned int limit;
186 unsigned int batchcount;
187 unsigned int shared;
188 unsigned int objects_per_slab;
189 unsigned int cache_order;
190};
191
192void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
193void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
194ssize_t slabinfo_write(struct file *file, const char __user *buffer,
195 size_t count, loff_t *ppos);
196
197/*
198 * Generic implementation of bulk operations
199 * These are useful for situations in which the allocator cannot
200 * perform optimizations. In that case segments of the object listed
201 * may be allocated or freed using these operations.
202 */
203void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
204int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
205
206#if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
207
208/* List of all root caches. */
209extern struct list_head slab_root_caches;
210#define root_caches_node memcg_params.__root_caches_node
211
212/*
213 * Iterate over all memcg caches of the given root cache. The caller must hold
214 * slab_mutex.
215 */
216#define for_each_memcg_cache(iter, root) \
217 list_for_each_entry(iter, &(root)->memcg_params.children, \
218 memcg_params.children_node)
219
220static inline bool is_root_cache(struct kmem_cache *s)
221{
222 return !s->memcg_params.root_cache;
223}
224
225static inline bool slab_equal_or_root(struct kmem_cache *s,
226 struct kmem_cache *p)
227{
228 return p == s || p == s->memcg_params.root_cache;
229}
230
231/*
232 * We use suffixes to the name in memcg because we can't have caches
233 * created in the system with the same name. But when we print them
234 * locally, better refer to them with the base name
235 */
236static inline const char *cache_name(struct kmem_cache *s)
237{
238 if (!is_root_cache(s))
239 s = s->memcg_params.root_cache;
240 return s->name;
241}
242
243/*
244 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
245 * That said the caller must assure the memcg's cache won't go away by either
246 * taking a css reference to the owner cgroup, or holding the slab_mutex.
247 */
248static inline struct kmem_cache *
249cache_from_memcg_idx(struct kmem_cache *s, int idx)
250{
251 struct kmem_cache *cachep;
252 struct memcg_cache_array *arr;
253
254 rcu_read_lock();
255 arr = rcu_dereference(s->memcg_params.memcg_caches);
256
257 /*
258 * Make sure we will access the up-to-date value. The code updating
259 * memcg_caches issues a write barrier to match this (see
260 * memcg_create_kmem_cache()).
261 */
262 cachep = READ_ONCE(arr->entries[idx]);
263 rcu_read_unlock();
264
265 return cachep;
266}
267
268static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
269{
270 if (is_root_cache(s))
271 return s;
272 return s->memcg_params.root_cache;
273}
274
275static __always_inline int memcg_charge_slab(struct page *page,
276 gfp_t gfp, int order,
277 struct kmem_cache *s)
278{
279 if (!memcg_kmem_enabled())
280 return 0;
281 if (is_root_cache(s))
282 return 0;
283 return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
284}
285
286static __always_inline void memcg_uncharge_slab(struct page *page, int order,
287 struct kmem_cache *s)
288{
289 if (!memcg_kmem_enabled())
290 return;
291 memcg_kmem_uncharge(page, order);
292}
293
294extern void slab_init_memcg_params(struct kmem_cache *);
295extern void memcg_link_cache(struct kmem_cache *s);
296extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
297 void (*deact_fn)(struct kmem_cache *));
298
299#else /* CONFIG_MEMCG && !CONFIG_SLOB */
300
301/* If !memcg, all caches are root. */
302#define slab_root_caches slab_caches
303#define root_caches_node list
304
305#define for_each_memcg_cache(iter, root) \
306 for ((void)(iter), (void)(root); 0; )
307
308static inline bool is_root_cache(struct kmem_cache *s)
309{
310 return true;
311}
312
313static inline bool slab_equal_or_root(struct kmem_cache *s,
314 struct kmem_cache *p)
315{
316 return true;
317}
318
319static inline const char *cache_name(struct kmem_cache *s)
320{
321 return s->name;
322}
323
324static inline struct kmem_cache *
325cache_from_memcg_idx(struct kmem_cache *s, int idx)
326{
327 return NULL;
328}
329
330static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
331{
332 return s;
333}
334
335static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
336 struct kmem_cache *s)
337{
338 return 0;
339}
340
341static inline void memcg_uncharge_slab(struct page *page, int order,
342 struct kmem_cache *s)
343{
344}
345
346static inline void slab_init_memcg_params(struct kmem_cache *s)
347{
348}
349
350static inline void memcg_link_cache(struct kmem_cache *s)
351{
352}
353
354#endif /* CONFIG_MEMCG && !CONFIG_SLOB */
355
356static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
357{
358 struct kmem_cache *cachep;
359 struct page *page;
360
361 /*
362 * When kmemcg is not being used, both assignments should return the
363 * same value. but we don't want to pay the assignment price in that
364 * case. If it is not compiled in, the compiler should be smart enough
365 * to not do even the assignment. In that case, slab_equal_or_root
366 * will also be a constant.
367 */
368 if (!memcg_kmem_enabled() &&
369 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
370 return s;
371
372 page = virt_to_head_page(x);
373 cachep = page->slab_cache;
374 if (slab_equal_or_root(cachep, s))
375 return cachep;
376
377 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
378 __func__, s->name, cachep->name);
379 WARN_ON_ONCE(1);
380 return s;
381}
382
383static inline size_t slab_ksize(const struct kmem_cache *s)
384{
385#ifndef CONFIG_SLUB
386 return s->object_size;
387
388#else /* CONFIG_SLUB */
389# ifdef CONFIG_SLUB_DEBUG
390 /*
391 * Debugging requires use of the padding between object
392 * and whatever may come after it.
393 */
394 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
395 return s->object_size;
396# endif
397 if (s->flags & SLAB_KASAN)
398 return s->object_size;
399 /*
400 * If we have the need to store the freelist pointer
401 * back there or track user information then we can
402 * only use the space before that information.
403 */
404 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
405 return s->inuse;
406 /*
407 * Else we can use all the padding etc for the allocation
408 */
409 return s->size;
410#endif
411}
412
413static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
414 gfp_t flags)
415{
416 flags &= gfp_allowed_mask;
417
418 fs_reclaim_acquire(flags);
419 fs_reclaim_release(flags);
420
421 might_sleep_if(gfpflags_allow_blocking(flags));
422
423 if (should_failslab(s, flags))
424 return NULL;
425
426 if (memcg_kmem_enabled() &&
427 ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
428 return memcg_kmem_get_cache(s);
429
430 return s;
431}
432
433static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
434 size_t size, void **p)
435{
436 size_t i;
437
438 flags &= gfp_allowed_mask;
439 for (i = 0; i < size; i++) {
440 void *object = p[i];
441
442 kmemleak_alloc_recursive(object, s->object_size, 1,
443 s->flags, flags);
444 kasan_slab_alloc(s, object, flags);
445 }
446
447 if (memcg_kmem_enabled())
448 memcg_kmem_put_cache(s);
449}
450
451#ifndef CONFIG_SLOB
452/*
453 * The slab lists for all objects.
454 */
455struct kmem_cache_node {
456 spinlock_t list_lock;
457
458#ifdef CONFIG_SLAB
459 struct list_head slabs_partial; /* partial list first, better asm code */
460 struct list_head slabs_full;
461 struct list_head slabs_free;
462 unsigned long total_slabs; /* length of all slab lists */
463 unsigned long free_slabs; /* length of free slab list only */
464 unsigned long free_objects;
465 unsigned int free_limit;
466 unsigned int colour_next; /* Per-node cache coloring */
467 struct array_cache *shared; /* shared per node */
468 struct alien_cache **alien; /* on other nodes */
469 unsigned long next_reap; /* updated without locking */
470 int free_touched; /* updated without locking */
471#endif
472
473#ifdef CONFIG_SLUB
474 unsigned long nr_partial;
475 struct list_head partial;
476#ifdef CONFIG_SLUB_DEBUG
477 atomic_long_t nr_slabs;
478 atomic_long_t total_objects;
479 struct list_head full;
480#endif
481#endif
482
483};
484
485static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
486{
487 return s->node[node];
488}
489
490/*
491 * Iterator over all nodes. The body will be executed for each node that has
492 * a kmem_cache_node structure allocated (which is true for all online nodes)
493 */
494#define for_each_kmem_cache_node(__s, __node, __n) \
495 for (__node = 0; __node < nr_node_ids; __node++) \
496 if ((__n = get_node(__s, __node)))
497
498#endif
499
500void *slab_start(struct seq_file *m, loff_t *pos);
501void *slab_next(struct seq_file *m, void *p, loff_t *pos);
502void slab_stop(struct seq_file *m, void *p);
503void *memcg_slab_start(struct seq_file *m, loff_t *pos);
504void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
505void memcg_slab_stop(struct seq_file *m, void *p);
506int memcg_slab_show(struct seq_file *m, void *p);
507
508#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
509void dump_unreclaimable_slab(void);
510#else
511static inline void dump_unreclaimable_slab(void)
512{
513}
514#endif
515
516void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
517
518#ifdef CONFIG_SLAB_FREELIST_RANDOM
519int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
520 gfp_t gfp);
521void cache_random_seq_destroy(struct kmem_cache *cachep);
522#else
523static inline int cache_random_seq_create(struct kmem_cache *cachep,
524 unsigned int count, gfp_t gfp)
525{
526 return 0;
527}
528static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
529#endif /* CONFIG_SLAB_FREELIST_RANDOM */
530
531#endif /* MM_SLAB_H */