Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.1.
  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#include <linux/kmemleak.h>
 50
 51/*
 52 * State of the slab allocator.
 53 *
 54 * This is used to describe the states of the allocator during bootup.
 55 * Allocators use this to gradually bootstrap themselves. Most allocators
 56 * have the problem that the structures used for managing slab caches are
 57 * allocated from slab caches themselves.
 58 */
 59enum slab_state {
 60	DOWN,			/* No slab functionality yet */
 61	PARTIAL,		/* SLUB: kmem_cache_node available */
 62	PARTIAL_NODE,		/* SLAB: kmalloc size for node struct available */
 63	UP,			/* Slab caches usable but not all extras yet */
 64	FULL			/* Everything is working */
 65};
 66
 67extern enum slab_state slab_state;
 68
 69/* The slab cache mutex protects the management structures during changes */
 70extern struct mutex slab_mutex;
 71
 72/* The list of all slab caches on the system */
 73extern struct list_head slab_caches;
 74
 75/* The slab cache that manages slab cache information */
 76extern struct kmem_cache *kmem_cache;
 77
 78/* A table of kmalloc cache names and sizes */
 79extern const struct kmalloc_info_struct {
 80	const char *name[NR_KMALLOC_TYPES];
 81	unsigned int size;
 82} kmalloc_info[];
 83
 84#ifndef CONFIG_SLOB
 85/* Kmalloc array related functions */
 86void setup_kmalloc_cache_index_table(void);
 87void create_kmalloc_caches(slab_flags_t);
 88
 89/* Find the kmalloc slab corresponding for a certain size */
 90struct kmem_cache *kmalloc_slab(size_t, gfp_t);
 91#endif
 92
 93gfp_t kmalloc_fix_flags(gfp_t flags);
 94
 95/* Functions provided by the slab allocators */
 96int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
 97
 98struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
 99			slab_flags_t flags, unsigned int useroffset,
100			unsigned int usersize);
101extern void create_boot_cache(struct kmem_cache *, const char *name,
102			unsigned int size, slab_flags_t flags,
103			unsigned int useroffset, unsigned int usersize);
104
105int slab_unmergeable(struct kmem_cache *s);
106struct kmem_cache *find_mergeable(unsigned size, unsigned align,
107		slab_flags_t flags, const char *name, void (*ctor)(void *));
108#ifndef CONFIG_SLOB
109struct kmem_cache *
110__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
111		   slab_flags_t flags, void (*ctor)(void *));
112
113slab_flags_t kmem_cache_flags(unsigned int object_size,
114	slab_flags_t flags, const char *name,
115	void (*ctor)(void *));
116#else
117static inline struct kmem_cache *
118__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
119		   slab_flags_t flags, void (*ctor)(void *))
120{ return NULL; }
121
122static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
123	slab_flags_t flags, const char *name,
124	void (*ctor)(void *))
125{
126	return flags;
127}
128#endif
129
130
131/* Legal flag mask for kmem_cache_create(), for various configurations */
132#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
133			 SLAB_CACHE_DMA32 | SLAB_PANIC | \
134			 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
135
136#if defined(CONFIG_DEBUG_SLAB)
137#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
138#elif defined(CONFIG_SLUB_DEBUG)
139#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
140			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
141#else
142#define SLAB_DEBUG_FLAGS (0)
143#endif
144
145#if defined(CONFIG_SLAB)
146#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
147			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
148			  SLAB_ACCOUNT)
149#elif defined(CONFIG_SLUB)
150#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
151			  SLAB_TEMPORARY | SLAB_ACCOUNT)
152#else
153#define SLAB_CACHE_FLAGS (0)
154#endif
155
156/* Common flags available with current configuration */
157#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
158
159/* Common flags permitted for kmem_cache_create */
160#define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
161			      SLAB_RED_ZONE | \
162			      SLAB_POISON | \
163			      SLAB_STORE_USER | \
164			      SLAB_TRACE | \
165			      SLAB_CONSISTENCY_CHECKS | \
166			      SLAB_MEM_SPREAD | \
167			      SLAB_NOLEAKTRACE | \
168			      SLAB_RECLAIM_ACCOUNT | \
169			      SLAB_TEMPORARY | \
170			      SLAB_ACCOUNT)
171
172bool __kmem_cache_empty(struct kmem_cache *);
173int __kmem_cache_shutdown(struct kmem_cache *);
174void __kmem_cache_release(struct kmem_cache *);
175int __kmem_cache_shrink(struct kmem_cache *);
176void slab_kmem_cache_release(struct kmem_cache *);
177
178struct seq_file;
179struct file;
180
181struct slabinfo {
182	unsigned long active_objs;
183	unsigned long num_objs;
184	unsigned long active_slabs;
185	unsigned long num_slabs;
186	unsigned long shared_avail;
187	unsigned int limit;
188	unsigned int batchcount;
189	unsigned int shared;
190	unsigned int objects_per_slab;
191	unsigned int cache_order;
192};
193
194void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
195void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
196ssize_t slabinfo_write(struct file *file, const char __user *buffer,
197		       size_t count, loff_t *ppos);
198
199/*
200 * Generic implementation of bulk operations
201 * These are useful for situations in which the allocator cannot
202 * perform optimizations. In that case segments of the object listed
203 * may be allocated or freed using these operations.
204 */
205void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
206int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
207
208static inline int cache_vmstat_idx(struct kmem_cache *s)
209{
210	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
211		NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
212}
213
214#ifdef CONFIG_SLUB_DEBUG
215#ifdef CONFIG_SLUB_DEBUG_ON
216DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
217#else
218DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
219#endif
220extern void print_tracking(struct kmem_cache *s, void *object);
221#else
222static inline void print_tracking(struct kmem_cache *s, void *object)
223{
224}
225#endif
226
227/*
228 * Returns true if any of the specified slub_debug flags is enabled for the
229 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
230 * the static key.
231 */
232static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
233{
234#ifdef CONFIG_SLUB_DEBUG
235	VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
236	if (static_branch_unlikely(&slub_debug_enabled))
237		return s->flags & flags;
238#endif
239	return false;
240}
241
242#ifdef CONFIG_MEMCG_KMEM
243static inline struct obj_cgroup **page_obj_cgroups(struct page *page)
244{
245	/*
246	 * page->mem_cgroup and page->obj_cgroups are sharing the same
247	 * space. To distinguish between them in case we don't know for sure
248	 * that the page is a slab page (e.g. page_cgroup_ino()), let's
249	 * always set the lowest bit of obj_cgroups.
250	 */
251	return (struct obj_cgroup **)
252		((unsigned long)page->obj_cgroups & ~0x1UL);
253}
254
255static inline bool page_has_obj_cgroups(struct page *page)
256{
257	return ((unsigned long)page->obj_cgroups & 0x1UL);
258}
259
260int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
261				 gfp_t gfp);
262
263static inline void memcg_free_page_obj_cgroups(struct page *page)
264{
265	kfree(page_obj_cgroups(page));
266	page->obj_cgroups = NULL;
267}
268
269static inline size_t obj_full_size(struct kmem_cache *s)
270{
271	/*
272	 * For each accounted object there is an extra space which is used
273	 * to store obj_cgroup membership. Charge it too.
274	 */
275	return s->size + sizeof(struct obj_cgroup *);
276}
277
278static inline struct obj_cgroup *memcg_slab_pre_alloc_hook(struct kmem_cache *s,
279							   size_t objects,
280							   gfp_t flags)
281{
282	struct obj_cgroup *objcg;
283
284	if (memcg_kmem_bypass())
285		return NULL;
286
287	objcg = get_obj_cgroup_from_current();
288	if (!objcg)
289		return NULL;
290
291	if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) {
292		obj_cgroup_put(objcg);
293		return NULL;
294	}
295
296	return objcg;
297}
298
299static inline void mod_objcg_state(struct obj_cgroup *objcg,
300				   struct pglist_data *pgdat,
301				   int idx, int nr)
302{
303	struct mem_cgroup *memcg;
304	struct lruvec *lruvec;
305
306	rcu_read_lock();
307	memcg = obj_cgroup_memcg(objcg);
308	lruvec = mem_cgroup_lruvec(memcg, pgdat);
309	mod_memcg_lruvec_state(lruvec, idx, nr);
310	rcu_read_unlock();
311}
312
313static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
314					      struct obj_cgroup *objcg,
315					      gfp_t flags, size_t size,
316					      void **p)
317{
318	struct page *page;
319	unsigned long off;
320	size_t i;
321
322	if (!objcg)
323		return;
324
325	flags &= ~__GFP_ACCOUNT;
326	for (i = 0; i < size; i++) {
327		if (likely(p[i])) {
328			page = virt_to_head_page(p[i]);
329
330			if (!page_has_obj_cgroups(page) &&
331			    memcg_alloc_page_obj_cgroups(page, s, flags)) {
332				obj_cgroup_uncharge(objcg, obj_full_size(s));
333				continue;
334			}
335
336			off = obj_to_index(s, page, p[i]);
337			obj_cgroup_get(objcg);
338			page_obj_cgroups(page)[off] = objcg;
339			mod_objcg_state(objcg, page_pgdat(page),
340					cache_vmstat_idx(s), obj_full_size(s));
341		} else {
342			obj_cgroup_uncharge(objcg, obj_full_size(s));
343		}
344	}
345	obj_cgroup_put(objcg);
346}
347
348static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page,
349					void *p)
350{
351	struct obj_cgroup *objcg;
352	unsigned int off;
353
354	if (!memcg_kmem_enabled())
355		return;
356
357	if (!page_has_obj_cgroups(page))
358		return;
359
360	off = obj_to_index(s, page, p);
361	objcg = page_obj_cgroups(page)[off];
362	page_obj_cgroups(page)[off] = NULL;
363
364	if (!objcg)
365		return;
366
367	obj_cgroup_uncharge(objcg, obj_full_size(s));
368	mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s),
369			-obj_full_size(s));
370
371	obj_cgroup_put(objcg);
372}
373
374#else /* CONFIG_MEMCG_KMEM */
375static inline bool page_has_obj_cgroups(struct page *page)
376{
377	return false;
378}
379
380static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
381{
382	return NULL;
383}
384
385static inline int memcg_alloc_page_obj_cgroups(struct page *page,
386					       struct kmem_cache *s, gfp_t gfp)
387{
388	return 0;
389}
390
391static inline void memcg_free_page_obj_cgroups(struct page *page)
392{
393}
394
395static inline struct obj_cgroup *memcg_slab_pre_alloc_hook(struct kmem_cache *s,
396							   size_t objects,
397							   gfp_t flags)
398{
399	return NULL;
400}
401
402static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
403					      struct obj_cgroup *objcg,
404					      gfp_t flags, size_t size,
405					      void **p)
406{
407}
408
409static inline void memcg_slab_free_hook(struct kmem_cache *s, struct page *page,
410					void *p)
411{
412}
413#endif /* CONFIG_MEMCG_KMEM */
414
415static inline struct kmem_cache *virt_to_cache(const void *obj)
416{
417	struct page *page;
418
419	page = virt_to_head_page(obj);
420	if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n",
421					__func__))
422		return NULL;
423	return page->slab_cache;
424}
425
426static __always_inline void account_slab_page(struct page *page, int order,
427					      struct kmem_cache *s)
428{
429	mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
430			    PAGE_SIZE << order);
431}
432
433static __always_inline void unaccount_slab_page(struct page *page, int order,
434						struct kmem_cache *s)
435{
436	if (memcg_kmem_enabled())
437		memcg_free_page_obj_cgroups(page);
438
439	mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
440			    -(PAGE_SIZE << order));
441}
442
443static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
444{
445	struct kmem_cache *cachep;
446
447	if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
448	    !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
449		return s;
450
451	cachep = virt_to_cache(x);
452	if (WARN(cachep && cachep != s,
453		  "%s: Wrong slab cache. %s but object is from %s\n",
454		  __func__, s->name, cachep->name))
455		print_tracking(cachep, x);
456	return cachep;
457}
458
459static inline size_t slab_ksize(const struct kmem_cache *s)
460{
461#ifndef CONFIG_SLUB
462	return s->object_size;
463
464#else /* CONFIG_SLUB */
465# ifdef CONFIG_SLUB_DEBUG
466	/*
467	 * Debugging requires use of the padding between object
468	 * and whatever may come after it.
469	 */
470	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
471		return s->object_size;
472# endif
473	if (s->flags & SLAB_KASAN)
474		return s->object_size;
475	/*
476	 * If we have the need to store the freelist pointer
477	 * back there or track user information then we can
478	 * only use the space before that information.
479	 */
480	if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
481		return s->inuse;
482	/*
483	 * Else we can use all the padding etc for the allocation
484	 */
485	return s->size;
486#endif
487}
488
489static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
490						     struct obj_cgroup **objcgp,
491						     size_t size, gfp_t flags)
492{
493	flags &= gfp_allowed_mask;
494
495	fs_reclaim_acquire(flags);
496	fs_reclaim_release(flags);
497
498	might_sleep_if(gfpflags_allow_blocking(flags));
499
500	if (should_failslab(s, flags))
501		return NULL;
502
503	if (memcg_kmem_enabled() &&
504	    ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
505		*objcgp = memcg_slab_pre_alloc_hook(s, size, flags);
506
507	return s;
508}
509
510static inline void slab_post_alloc_hook(struct kmem_cache *s,
511					struct obj_cgroup *objcg,
512					gfp_t flags, size_t size, void **p)
513{
514	size_t i;
515
516	flags &= gfp_allowed_mask;
517	for (i = 0; i < size; i++) {
518		p[i] = kasan_slab_alloc(s, p[i], flags);
519		/* As p[i] might get tagged, call kmemleak hook after KASAN. */
520		kmemleak_alloc_recursive(p[i], s->object_size, 1,
521					 s->flags, flags);
522	}
523
524	if (memcg_kmem_enabled())
525		memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
526}
527
528#ifndef CONFIG_SLOB
529/*
530 * The slab lists for all objects.
531 */
532struct kmem_cache_node {
533	spinlock_t list_lock;
534
535#ifdef CONFIG_SLAB
536	struct list_head slabs_partial;	/* partial list first, better asm code */
537	struct list_head slabs_full;
538	struct list_head slabs_free;
539	unsigned long total_slabs;	/* length of all slab lists */
540	unsigned long free_slabs;	/* length of free slab list only */
541	unsigned long free_objects;
542	unsigned int free_limit;
543	unsigned int colour_next;	/* Per-node cache coloring */
544	struct array_cache *shared;	/* shared per node */
545	struct alien_cache **alien;	/* on other nodes */
546	unsigned long next_reap;	/* updated without locking */
547	int free_touched;		/* updated without locking */
548#endif
549
550#ifdef CONFIG_SLUB
551	unsigned long nr_partial;
552	struct list_head partial;
553#ifdef CONFIG_SLUB_DEBUG
554	atomic_long_t nr_slabs;
555	atomic_long_t total_objects;
556	struct list_head full;
557#endif
558#endif
559
560};
561
562static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
563{
564	return s->node[node];
565}
566
567/*
568 * Iterator over all nodes. The body will be executed for each node that has
569 * a kmem_cache_node structure allocated (which is true for all online nodes)
570 */
571#define for_each_kmem_cache_node(__s, __node, __n) \
572	for (__node = 0; __node < nr_node_ids; __node++) \
573		 if ((__n = get_node(__s, __node)))
574
575#endif
576
577void *slab_start(struct seq_file *m, loff_t *pos);
578void *slab_next(struct seq_file *m, void *p, loff_t *pos);
579void slab_stop(struct seq_file *m, void *p);
580int memcg_slab_show(struct seq_file *m, void *p);
581
582#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
583void dump_unreclaimable_slab(void);
584#else
585static inline void dump_unreclaimable_slab(void)
586{
587}
588#endif
589
590void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
591
592#ifdef CONFIG_SLAB_FREELIST_RANDOM
593int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
594			gfp_t gfp);
595void cache_random_seq_destroy(struct kmem_cache *cachep);
596#else
597static inline int cache_random_seq_create(struct kmem_cache *cachep,
598					unsigned int count, gfp_t gfp)
599{
600	return 0;
601}
602static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
603#endif /* CONFIG_SLAB_FREELIST_RANDOM */
604
605static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
606{
607	if (static_branch_unlikely(&init_on_alloc)) {
608		if (c->ctor)
609			return false;
610		if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
611			return flags & __GFP_ZERO;
612		return true;
613	}
614	return flags & __GFP_ZERO;
615}
616
617static inline bool slab_want_init_on_free(struct kmem_cache *c)
618{
619	if (static_branch_unlikely(&init_on_free))
620		return !(c->ctor ||
621			 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
622	return false;
623}
624
625#endif /* MM_SLAB_H */