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#ifdef CONFIG_MEMCG_KMEM
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 (is_root_cache(s))
280 return 0;
281 return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
282}
283
284static __always_inline void memcg_uncharge_slab(struct page *page, int order,
285 struct kmem_cache *s)
286{
287 memcg_kmem_uncharge(page, order);
288}
289
290extern void slab_init_memcg_params(struct kmem_cache *);
291extern void memcg_link_cache(struct kmem_cache *s);
292extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
293 void (*deact_fn)(struct kmem_cache *));
294
295#else /* CONFIG_MEMCG_KMEM */
296
297/* If !memcg, all caches are root. */
298#define slab_root_caches slab_caches
299#define root_caches_node list
300
301#define for_each_memcg_cache(iter, root) \
302 for ((void)(iter), (void)(root); 0; )
303
304static inline bool is_root_cache(struct kmem_cache *s)
305{
306 return true;
307}
308
309static inline bool slab_equal_or_root(struct kmem_cache *s,
310 struct kmem_cache *p)
311{
312 return true;
313}
314
315static inline const char *cache_name(struct kmem_cache *s)
316{
317 return s->name;
318}
319
320static inline struct kmem_cache *
321cache_from_memcg_idx(struct kmem_cache *s, int idx)
322{
323 return NULL;
324}
325
326static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
327{
328 return s;
329}
330
331static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
332 struct kmem_cache *s)
333{
334 return 0;
335}
336
337static inline void memcg_uncharge_slab(struct page *page, int order,
338 struct kmem_cache *s)
339{
340}
341
342static inline void slab_init_memcg_params(struct kmem_cache *s)
343{
344}
345
346static inline void memcg_link_cache(struct kmem_cache *s)
347{
348}
349
350#endif /* CONFIG_MEMCG_KMEM */
351
352static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
353{
354 struct kmem_cache *cachep;
355 struct page *page;
356
357 /*
358 * When kmemcg is not being used, both assignments should return the
359 * same value. but we don't want to pay the assignment price in that
360 * case. If it is not compiled in, the compiler should be smart enough
361 * to not do even the assignment. In that case, slab_equal_or_root
362 * will also be a constant.
363 */
364 if (!memcg_kmem_enabled() &&
365 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
366 return s;
367
368 page = virt_to_head_page(x);
369 cachep = page->slab_cache;
370 if (slab_equal_or_root(cachep, s))
371 return cachep;
372
373 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
374 __func__, s->name, cachep->name);
375 WARN_ON_ONCE(1);
376 return s;
377}
378
379static inline size_t slab_ksize(const struct kmem_cache *s)
380{
381#ifndef CONFIG_SLUB
382 return s->object_size;
383
384#else /* CONFIG_SLUB */
385# ifdef CONFIG_SLUB_DEBUG
386 /*
387 * Debugging requires use of the padding between object
388 * and whatever may come after it.
389 */
390 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
391 return s->object_size;
392# endif
393 if (s->flags & SLAB_KASAN)
394 return s->object_size;
395 /*
396 * If we have the need to store the freelist pointer
397 * back there or track user information then we can
398 * only use the space before that information.
399 */
400 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
401 return s->inuse;
402 /*
403 * Else we can use all the padding etc for the allocation
404 */
405 return s->size;
406#endif
407}
408
409static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
410 gfp_t flags)
411{
412 flags &= gfp_allowed_mask;
413
414 fs_reclaim_acquire(flags);
415 fs_reclaim_release(flags);
416
417 might_sleep_if(gfpflags_allow_blocking(flags));
418
419 if (should_failslab(s, flags))
420 return NULL;
421
422 if (memcg_kmem_enabled() &&
423 ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
424 return memcg_kmem_get_cache(s);
425
426 return s;
427}
428
429static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
430 size_t size, void **p)
431{
432 size_t i;
433
434 flags &= gfp_allowed_mask;
435 for (i = 0; i < size; i++) {
436 p[i] = kasan_slab_alloc(s, p[i], flags);
437 /* As p[i] might get tagged, call kmemleak hook after KASAN. */
438 kmemleak_alloc_recursive(p[i], s->object_size, 1,
439 s->flags, flags);
440 }
441
442 if (memcg_kmem_enabled())
443 memcg_kmem_put_cache(s);
444}
445
446#ifndef CONFIG_SLOB
447/*
448 * The slab lists for all objects.
449 */
450struct kmem_cache_node {
451 spinlock_t list_lock;
452
453#ifdef CONFIG_SLAB
454 struct list_head slabs_partial; /* partial list first, better asm code */
455 struct list_head slabs_full;
456 struct list_head slabs_free;
457 unsigned long total_slabs; /* length of all slab lists */
458 unsigned long free_slabs; /* length of free slab list only */
459 unsigned long free_objects;
460 unsigned int free_limit;
461 unsigned int colour_next; /* Per-node cache coloring */
462 struct array_cache *shared; /* shared per node */
463 struct alien_cache **alien; /* on other nodes */
464 unsigned long next_reap; /* updated without locking */
465 int free_touched; /* updated without locking */
466#endif
467
468#ifdef CONFIG_SLUB
469 unsigned long nr_partial;
470 struct list_head partial;
471#ifdef CONFIG_SLUB_DEBUG
472 atomic_long_t nr_slabs;
473 atomic_long_t total_objects;
474 struct list_head full;
475#endif
476#endif
477
478};
479
480static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
481{
482 return s->node[node];
483}
484
485/*
486 * Iterator over all nodes. The body will be executed for each node that has
487 * a kmem_cache_node structure allocated (which is true for all online nodes)
488 */
489#define for_each_kmem_cache_node(__s, __node, __n) \
490 for (__node = 0; __node < nr_node_ids; __node++) \
491 if ((__n = get_node(__s, __node)))
492
493#endif
494
495void *slab_start(struct seq_file *m, loff_t *pos);
496void *slab_next(struct seq_file *m, void *p, loff_t *pos);
497void slab_stop(struct seq_file *m, void *p);
498void *memcg_slab_start(struct seq_file *m, loff_t *pos);
499void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos);
500void memcg_slab_stop(struct seq_file *m, void *p);
501int memcg_slab_show(struct seq_file *m, void *p);
502
503#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
504void dump_unreclaimable_slab(void);
505#else
506static inline void dump_unreclaimable_slab(void)
507{
508}
509#endif
510
511void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
512
513#ifdef CONFIG_SLAB_FREELIST_RANDOM
514int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
515 gfp_t gfp);
516void cache_random_seq_destroy(struct kmem_cache *cachep);
517#else
518static inline int cache_random_seq_create(struct kmem_cache *cachep,
519 unsigned int count, gfp_t gfp)
520{
521 return 0;
522}
523static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
524#endif /* CONFIG_SLAB_FREELIST_RANDOM */
525
526#endif /* MM_SLAB_H */
527