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 /* Reuses the bits in struct page */
9 struct slab {
10 	unsigned long __page_flags;
11 
12 #if defined(CONFIG_SLAB)
13 
14 	union {
15 		struct list_head slab_list;
16 		struct rcu_head rcu_head;
17 	};
18 	struct kmem_cache *slab_cache;
19 	void *freelist;	/* array of free object indexes */
20 	void *s_mem;	/* first object */
21 	unsigned int active;
22 
23 #elif defined(CONFIG_SLUB)
24 
25 	union {
26 		struct list_head slab_list;
27 		struct rcu_head rcu_head;
28 #ifdef CONFIG_SLUB_CPU_PARTIAL
29 		struct {
30 			struct slab *next;
31 			int slabs;	/* Nr of slabs left */
32 		};
33 #endif
34 	};
35 	struct kmem_cache *slab_cache;
36 	/* Double-word boundary */
37 	void *freelist;		/* first free object */
38 	union {
39 		unsigned long counters;
40 		struct {
41 			unsigned inuse:16;
42 			unsigned objects:15;
43 			unsigned frozen:1;
44 		};
45 	};
46 	unsigned int __unused;
47 
48 #elif defined(CONFIG_SLOB)
49 
50 	struct list_head slab_list;
51 	void *__unused_1;
52 	void *freelist;		/* first free block */
53 	long units;
54 	unsigned int __unused_2;
55 
56 #else
57 #error "Unexpected slab allocator configured"
58 #endif
59 
60 	atomic_t __page_refcount;
61 #ifdef CONFIG_MEMCG
62 	unsigned long memcg_data;
63 #endif
64 };
65 
66 #define SLAB_MATCH(pg, sl)						\
67 	static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
68 SLAB_MATCH(flags, __page_flags);
69 SLAB_MATCH(compound_head, slab_list);	/* Ensure bit 0 is clear */
70 #ifndef CONFIG_SLOB
71 SLAB_MATCH(rcu_head, rcu_head);
72 #endif
73 SLAB_MATCH(_refcount, __page_refcount);
74 #ifdef CONFIG_MEMCG
75 SLAB_MATCH(memcg_data, memcg_data);
76 #endif
77 #undef SLAB_MATCH
78 static_assert(sizeof(struct slab) <= sizeof(struct page));
79 
80 /**
81  * folio_slab - Converts from folio to slab.
82  * @folio: The folio.
83  *
84  * Currently struct slab is a different representation of a folio where
85  * folio_test_slab() is true.
86  *
87  * Return: The slab which contains this folio.
88  */
89 #define folio_slab(folio)	(_Generic((folio),			\
90 	const struct folio *:	(const struct slab *)(folio),		\
91 	struct folio *:		(struct slab *)(folio)))
92 
93 /**
94  * slab_folio - The folio allocated for a slab
95  * @slab: The slab.
96  *
97  * Slabs are allocated as folios that contain the individual objects and are
98  * using some fields in the first struct page of the folio - those fields are
99  * now accessed by struct slab. It is occasionally necessary to convert back to
100  * a folio in order to communicate with the rest of the mm.  Please use this
101  * helper function instead of casting yourself, as the implementation may change
102  * in the future.
103  */
104 #define slab_folio(s)		(_Generic((s),				\
105 	const struct slab *:	(const struct folio *)s,		\
106 	struct slab *:		(struct folio *)s))
107 
108 /**
109  * page_slab - Converts from first struct page to slab.
110  * @p: The first (either head of compound or single) page of slab.
111  *
112  * A temporary wrapper to convert struct page to struct slab in situations where
113  * we know the page is the compound head, or single order-0 page.
114  *
115  * Long-term ideally everything would work with struct slab directly or go
116  * through folio to struct slab.
117  *
118  * Return: The slab which contains this page
119  */
120 #define page_slab(p)		(_Generic((p),				\
121 	const struct page *:	(const struct slab *)(p),		\
122 	struct page *:		(struct slab *)(p)))
123 
124 /**
125  * slab_page - The first struct page allocated for a slab
126  * @slab: The slab.
127  *
128  * A convenience wrapper for converting slab to the first struct page of the
129  * underlying folio, to communicate with code not yet converted to folio or
130  * struct slab.
131  */
132 #define slab_page(s) folio_page(slab_folio(s), 0)
133 
134 /*
135  * If network-based swap is enabled, sl*b must keep track of whether pages
136  * were allocated from pfmemalloc reserves.
137  */
slab_test_pfmemalloc(const struct slab * slab)138 static inline bool slab_test_pfmemalloc(const struct slab *slab)
139 {
140 	return folio_test_active((struct folio *)slab_folio(slab));
141 }
142 
slab_set_pfmemalloc(struct slab * slab)143 static inline void slab_set_pfmemalloc(struct slab *slab)
144 {
145 	folio_set_active(slab_folio(slab));
146 }
147 
slab_clear_pfmemalloc(struct slab * slab)148 static inline void slab_clear_pfmemalloc(struct slab *slab)
149 {
150 	folio_clear_active(slab_folio(slab));
151 }
152 
__slab_clear_pfmemalloc(struct slab * slab)153 static inline void __slab_clear_pfmemalloc(struct slab *slab)
154 {
155 	__folio_clear_active(slab_folio(slab));
156 }
157 
slab_address(const struct slab * slab)158 static inline void *slab_address(const struct slab *slab)
159 {
160 	return folio_address(slab_folio(slab));
161 }
162 
slab_nid(const struct slab * slab)163 static inline int slab_nid(const struct slab *slab)
164 {
165 	return folio_nid(slab_folio(slab));
166 }
167 
slab_pgdat(const struct slab * slab)168 static inline pg_data_t *slab_pgdat(const struct slab *slab)
169 {
170 	return folio_pgdat(slab_folio(slab));
171 }
172 
virt_to_slab(const void * addr)173 static inline struct slab *virt_to_slab(const void *addr)
174 {
175 	struct folio *folio = virt_to_folio(addr);
176 
177 	if (!folio_test_slab(folio))
178 		return NULL;
179 
180 	return folio_slab(folio);
181 }
182 
slab_order(const struct slab * slab)183 static inline int slab_order(const struct slab *slab)
184 {
185 	return folio_order((struct folio *)slab_folio(slab));
186 }
187 
slab_size(const struct slab * slab)188 static inline size_t slab_size(const struct slab *slab)
189 {
190 	return PAGE_SIZE << slab_order(slab);
191 }
192 
193 #ifdef CONFIG_SLOB
194 /*
195  * Common fields provided in kmem_cache by all slab allocators
196  * This struct is either used directly by the allocator (SLOB)
197  * or the allocator must include definitions for all fields
198  * provided in kmem_cache_common in their definition of kmem_cache.
199  *
200  * Once we can do anonymous structs (C11 standard) we could put a
201  * anonymous struct definition in these allocators so that the
202  * separate allocations in the kmem_cache structure of SLAB and
203  * SLUB is no longer needed.
204  */
205 struct kmem_cache {
206 	unsigned int object_size;/* The original size of the object */
207 	unsigned int size;	/* The aligned/padded/added on size  */
208 	unsigned int align;	/* Alignment as calculated */
209 	slab_flags_t flags;	/* Active flags on the slab */
210 	unsigned int useroffset;/* Usercopy region offset */
211 	unsigned int usersize;	/* Usercopy region size */
212 	const char *name;	/* Slab name for sysfs */
213 	int refcount;		/* Use counter */
214 	void (*ctor)(void *);	/* Called on object slot creation */
215 	struct list_head list;	/* List of all slab caches on the system */
216 };
217 
218 #endif /* CONFIG_SLOB */
219 
220 #ifdef CONFIG_SLAB
221 #include <linux/slab_def.h>
222 #endif
223 
224 #ifdef CONFIG_SLUB
225 #include <linux/slub_def.h>
226 #endif
227 
228 #include <linux/memcontrol.h>
229 #include <linux/fault-inject.h>
230 #include <linux/kasan.h>
231 #include <linux/kmemleak.h>
232 #include <linux/random.h>
233 #include <linux/sched/mm.h>
234 #include <linux/list_lru.h>
235 
236 /*
237  * State of the slab allocator.
238  *
239  * This is used to describe the states of the allocator during bootup.
240  * Allocators use this to gradually bootstrap themselves. Most allocators
241  * have the problem that the structures used for managing slab caches are
242  * allocated from slab caches themselves.
243  */
244 enum slab_state {
245 	DOWN,			/* No slab functionality yet */
246 	PARTIAL,		/* SLUB: kmem_cache_node available */
247 	PARTIAL_NODE,		/* SLAB: kmalloc size for node struct available */
248 	UP,			/* Slab caches usable but not all extras yet */
249 	FULL			/* Everything is working */
250 };
251 
252 extern enum slab_state slab_state;
253 
254 /* The slab cache mutex protects the management structures during changes */
255 extern struct mutex slab_mutex;
256 
257 /* The list of all slab caches on the system */
258 extern struct list_head slab_caches;
259 
260 /* The slab cache that manages slab cache information */
261 extern struct kmem_cache *kmem_cache;
262 
263 /* A table of kmalloc cache names and sizes */
264 extern const struct kmalloc_info_struct {
265 	const char *name[NR_KMALLOC_TYPES];
266 	unsigned int size;
267 } kmalloc_info[];
268 
269 #ifndef CONFIG_SLOB
270 /* Kmalloc array related functions */
271 void setup_kmalloc_cache_index_table(void);
272 void create_kmalloc_caches(slab_flags_t);
273 
274 /* Find the kmalloc slab corresponding for a certain size */
275 struct kmem_cache *kmalloc_slab(size_t, gfp_t);
276 #endif
277 
278 gfp_t kmalloc_fix_flags(gfp_t flags);
279 
280 /* Functions provided by the slab allocators */
281 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
282 
283 struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size,
284 			slab_flags_t flags, unsigned int useroffset,
285 			unsigned int usersize);
286 extern void create_boot_cache(struct kmem_cache *, const char *name,
287 			unsigned int size, slab_flags_t flags,
288 			unsigned int useroffset, unsigned int usersize);
289 
290 int slab_unmergeable(struct kmem_cache *s);
291 struct kmem_cache *find_mergeable(unsigned size, unsigned align,
292 		slab_flags_t flags, const char *name, void (*ctor)(void *));
293 #ifndef CONFIG_SLOB
294 struct kmem_cache *
295 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
296 		   slab_flags_t flags, void (*ctor)(void *));
297 
298 slab_flags_t kmem_cache_flags(unsigned int object_size,
299 	slab_flags_t flags, const char *name);
300 #else
301 static inline struct kmem_cache *
__kmem_cache_alias(const char * name,unsigned int size,unsigned int align,slab_flags_t flags,void (* ctor)(void *))302 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
303 		   slab_flags_t flags, void (*ctor)(void *))
304 { return NULL; }
305 
kmem_cache_flags(unsigned int object_size,slab_flags_t flags,const char * name)306 static inline slab_flags_t kmem_cache_flags(unsigned int object_size,
307 	slab_flags_t flags, const char *name)
308 {
309 	return flags;
310 }
311 #endif
312 
313 
314 /* Legal flag mask for kmem_cache_create(), for various configurations */
315 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
316 			 SLAB_CACHE_DMA32 | SLAB_PANIC | \
317 			 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
318 
319 #if defined(CONFIG_DEBUG_SLAB)
320 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
321 #elif defined(CONFIG_SLUB_DEBUG)
322 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
323 			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
324 #else
325 #define SLAB_DEBUG_FLAGS (0)
326 #endif
327 
328 #if defined(CONFIG_SLAB)
329 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
330 			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
331 			  SLAB_ACCOUNT)
332 #elif defined(CONFIG_SLUB)
333 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
334 			  SLAB_TEMPORARY | SLAB_ACCOUNT | SLAB_NO_USER_FLAGS)
335 #else
336 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE)
337 #endif
338 
339 /* Common flags available with current configuration */
340 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
341 
342 /* Common flags permitted for kmem_cache_create */
343 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
344 			      SLAB_RED_ZONE | \
345 			      SLAB_POISON | \
346 			      SLAB_STORE_USER | \
347 			      SLAB_TRACE | \
348 			      SLAB_CONSISTENCY_CHECKS | \
349 			      SLAB_MEM_SPREAD | \
350 			      SLAB_NOLEAKTRACE | \
351 			      SLAB_RECLAIM_ACCOUNT | \
352 			      SLAB_TEMPORARY | \
353 			      SLAB_ACCOUNT | \
354 			      SLAB_NO_USER_FLAGS)
355 
356 bool __kmem_cache_empty(struct kmem_cache *);
357 int __kmem_cache_shutdown(struct kmem_cache *);
358 void __kmem_cache_release(struct kmem_cache *);
359 int __kmem_cache_shrink(struct kmem_cache *);
360 void slab_kmem_cache_release(struct kmem_cache *);
361 
362 struct seq_file;
363 struct file;
364 
365 struct slabinfo {
366 	unsigned long active_objs;
367 	unsigned long num_objs;
368 	unsigned long active_slabs;
369 	unsigned long num_slabs;
370 	unsigned long shared_avail;
371 	unsigned int limit;
372 	unsigned int batchcount;
373 	unsigned int shared;
374 	unsigned int objects_per_slab;
375 	unsigned int cache_order;
376 };
377 
378 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
379 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
380 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
381 		       size_t count, loff_t *ppos);
382 
383 /*
384  * Generic implementation of bulk operations
385  * These are useful for situations in which the allocator cannot
386  * perform optimizations. In that case segments of the object listed
387  * may be allocated or freed using these operations.
388  */
389 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
390 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
391 
cache_vmstat_idx(struct kmem_cache * s)392 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
393 {
394 	return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
395 		NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
396 }
397 
398 #ifdef CONFIG_SLUB_DEBUG
399 #ifdef CONFIG_SLUB_DEBUG_ON
400 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
401 #else
402 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
403 #endif
404 extern void print_tracking(struct kmem_cache *s, void *object);
405 long validate_slab_cache(struct kmem_cache *s);
__slub_debug_enabled(void)406 static inline bool __slub_debug_enabled(void)
407 {
408 	return static_branch_unlikely(&slub_debug_enabled);
409 }
410 #else
print_tracking(struct kmem_cache * s,void * object)411 static inline void print_tracking(struct kmem_cache *s, void *object)
412 {
413 }
__slub_debug_enabled(void)414 static inline bool __slub_debug_enabled(void)
415 {
416 	return false;
417 }
418 #endif
419 
420 /*
421  * Returns true if any of the specified slub_debug flags is enabled for the
422  * cache. Use only for flags parsed by setup_slub_debug() as it also enables
423  * the static key.
424  */
kmem_cache_debug_flags(struct kmem_cache * s,slab_flags_t flags)425 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
426 {
427 	if (IS_ENABLED(CONFIG_SLUB_DEBUG))
428 		VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
429 	if (__slub_debug_enabled())
430 		return s->flags & flags;
431 	return false;
432 }
433 
434 #ifdef CONFIG_MEMCG_KMEM
435 /*
436  * slab_objcgs - get the object cgroups vector associated with a slab
437  * @slab: a pointer to the slab struct
438  *
439  * Returns a pointer to the object cgroups vector associated with the slab,
440  * or NULL if no such vector has been associated yet.
441  */
slab_objcgs(struct slab * slab)442 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
443 {
444 	unsigned long memcg_data = READ_ONCE(slab->memcg_data);
445 
446 	VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS),
447 							slab_page(slab));
448 	VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
449 
450 	return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
451 }
452 
453 int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
454 				 gfp_t gfp, bool new_slab);
455 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
456 		     enum node_stat_item idx, int nr);
457 
memcg_free_slab_cgroups(struct slab * slab)458 static inline void memcg_free_slab_cgroups(struct slab *slab)
459 {
460 	kfree(slab_objcgs(slab));
461 	slab->memcg_data = 0;
462 }
463 
obj_full_size(struct kmem_cache * s)464 static inline size_t obj_full_size(struct kmem_cache *s)
465 {
466 	/*
467 	 * For each accounted object there is an extra space which is used
468 	 * to store obj_cgroup membership. Charge it too.
469 	 */
470 	return s->size + sizeof(struct obj_cgroup *);
471 }
472 
473 /*
474  * Returns false if the allocation should fail.
475  */
memcg_slab_pre_alloc_hook(struct kmem_cache * s,struct list_lru * lru,struct obj_cgroup ** objcgp,size_t objects,gfp_t flags)476 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
477 					     struct list_lru *lru,
478 					     struct obj_cgroup **objcgp,
479 					     size_t objects, gfp_t flags)
480 {
481 	struct obj_cgroup *objcg;
482 
483 	if (!memcg_kmem_enabled())
484 		return true;
485 
486 	if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
487 		return true;
488 
489 	objcg = get_obj_cgroup_from_current();
490 	if (!objcg)
491 		return true;
492 
493 	if (lru) {
494 		int ret;
495 		struct mem_cgroup *memcg;
496 
497 		memcg = get_mem_cgroup_from_objcg(objcg);
498 		ret = memcg_list_lru_alloc(memcg, lru, flags);
499 		css_put(&memcg->css);
500 
501 		if (ret)
502 			goto out;
503 	}
504 
505 	if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
506 		goto out;
507 
508 	*objcgp = objcg;
509 	return true;
510 out:
511 	obj_cgroup_put(objcg);
512 	return false;
513 }
514 
memcg_slab_post_alloc_hook(struct kmem_cache * s,struct obj_cgroup * objcg,gfp_t flags,size_t size,void ** p)515 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
516 					      struct obj_cgroup *objcg,
517 					      gfp_t flags, size_t size,
518 					      void **p)
519 {
520 	struct slab *slab;
521 	unsigned long off;
522 	size_t i;
523 
524 	if (!memcg_kmem_enabled() || !objcg)
525 		return;
526 
527 	for (i = 0; i < size; i++) {
528 		if (likely(p[i])) {
529 			slab = virt_to_slab(p[i]);
530 
531 			if (!slab_objcgs(slab) &&
532 			    memcg_alloc_slab_cgroups(slab, s, flags,
533 							 false)) {
534 				obj_cgroup_uncharge(objcg, obj_full_size(s));
535 				continue;
536 			}
537 
538 			off = obj_to_index(s, slab, p[i]);
539 			obj_cgroup_get(objcg);
540 			slab_objcgs(slab)[off] = objcg;
541 			mod_objcg_state(objcg, slab_pgdat(slab),
542 					cache_vmstat_idx(s), obj_full_size(s));
543 		} else {
544 			obj_cgroup_uncharge(objcg, obj_full_size(s));
545 		}
546 	}
547 	obj_cgroup_put(objcg);
548 }
549 
memcg_slab_free_hook(struct kmem_cache * s_orig,void ** p,int objects)550 static inline void memcg_slab_free_hook(struct kmem_cache *s_orig,
551 					void **p, int objects)
552 {
553 	struct kmem_cache *s;
554 	struct obj_cgroup **objcgs;
555 	struct obj_cgroup *objcg;
556 	struct slab *slab;
557 	unsigned int off;
558 	int i;
559 
560 	if (!memcg_kmem_enabled())
561 		return;
562 
563 	for (i = 0; i < objects; i++) {
564 		if (unlikely(!p[i]))
565 			continue;
566 
567 		slab = virt_to_slab(p[i]);
568 		/* we could be given a kmalloc_large() object, skip those */
569 		if (!slab)
570 			continue;
571 
572 		objcgs = slab_objcgs(slab);
573 		if (!objcgs)
574 			continue;
575 
576 		if (!s_orig)
577 			s = slab->slab_cache;
578 		else
579 			s = s_orig;
580 
581 		off = obj_to_index(s, slab, p[i]);
582 		objcg = objcgs[off];
583 		if (!objcg)
584 			continue;
585 
586 		objcgs[off] = NULL;
587 		obj_cgroup_uncharge(objcg, obj_full_size(s));
588 		mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
589 				-obj_full_size(s));
590 		obj_cgroup_put(objcg);
591 	}
592 }
593 
594 #else /* CONFIG_MEMCG_KMEM */
slab_objcgs(struct slab * slab)595 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
596 {
597 	return NULL;
598 }
599 
memcg_from_slab_obj(void * ptr)600 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
601 {
602 	return NULL;
603 }
604 
memcg_alloc_slab_cgroups(struct slab * slab,struct kmem_cache * s,gfp_t gfp,bool new_slab)605 static inline int memcg_alloc_slab_cgroups(struct slab *slab,
606 					       struct kmem_cache *s, gfp_t gfp,
607 					       bool new_slab)
608 {
609 	return 0;
610 }
611 
memcg_free_slab_cgroups(struct slab * slab)612 static inline void memcg_free_slab_cgroups(struct slab *slab)
613 {
614 }
615 
memcg_slab_pre_alloc_hook(struct kmem_cache * s,struct list_lru * lru,struct obj_cgroup ** objcgp,size_t objects,gfp_t flags)616 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
617 					     struct list_lru *lru,
618 					     struct obj_cgroup **objcgp,
619 					     size_t objects, gfp_t flags)
620 {
621 	return true;
622 }
623 
memcg_slab_post_alloc_hook(struct kmem_cache * s,struct obj_cgroup * objcg,gfp_t flags,size_t size,void ** p)624 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
625 					      struct obj_cgroup *objcg,
626 					      gfp_t flags, size_t size,
627 					      void **p)
628 {
629 }
630 
memcg_slab_free_hook(struct kmem_cache * s,void ** p,int objects)631 static inline void memcg_slab_free_hook(struct kmem_cache *s,
632 					void **p, int objects)
633 {
634 }
635 #endif /* CONFIG_MEMCG_KMEM */
636 
637 #ifndef CONFIG_SLOB
virt_to_cache(const void * obj)638 static inline struct kmem_cache *virt_to_cache(const void *obj)
639 {
640 	struct slab *slab;
641 
642 	slab = virt_to_slab(obj);
643 	if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
644 					__func__))
645 		return NULL;
646 	return slab->slab_cache;
647 }
648 
account_slab(struct slab * slab,int order,struct kmem_cache * s,gfp_t gfp)649 static __always_inline void account_slab(struct slab *slab, int order,
650 					 struct kmem_cache *s, gfp_t gfp)
651 {
652 	if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT))
653 		memcg_alloc_slab_cgroups(slab, s, gfp, true);
654 
655 	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
656 			    PAGE_SIZE << order);
657 }
658 
unaccount_slab(struct slab * slab,int order,struct kmem_cache * s)659 static __always_inline void unaccount_slab(struct slab *slab, int order,
660 					   struct kmem_cache *s)
661 {
662 	if (memcg_kmem_enabled())
663 		memcg_free_slab_cgroups(slab);
664 
665 	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
666 			    -(PAGE_SIZE << order));
667 }
668 
cache_from_obj(struct kmem_cache * s,void * x)669 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
670 {
671 	struct kmem_cache *cachep;
672 
673 	if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
674 	    !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
675 		return s;
676 
677 	cachep = virt_to_cache(x);
678 	if (WARN(cachep && cachep != s,
679 		  "%s: Wrong slab cache. %s but object is from %s\n",
680 		  __func__, s->name, cachep->name))
681 		print_tracking(cachep, x);
682 	return cachep;
683 }
684 #endif /* CONFIG_SLOB */
685 
slab_ksize(const struct kmem_cache * s)686 static inline size_t slab_ksize(const struct kmem_cache *s)
687 {
688 #ifndef CONFIG_SLUB
689 	return s->object_size;
690 
691 #else /* CONFIG_SLUB */
692 # ifdef CONFIG_SLUB_DEBUG
693 	/*
694 	 * Debugging requires use of the padding between object
695 	 * and whatever may come after it.
696 	 */
697 	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
698 		return s->object_size;
699 # endif
700 	if (s->flags & SLAB_KASAN)
701 		return s->object_size;
702 	/*
703 	 * If we have the need to store the freelist pointer
704 	 * back there or track user information then we can
705 	 * only use the space before that information.
706 	 */
707 	if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
708 		return s->inuse;
709 	/*
710 	 * Else we can use all the padding etc for the allocation
711 	 */
712 	return s->size;
713 #endif
714 }
715 
slab_pre_alloc_hook(struct kmem_cache * s,struct list_lru * lru,struct obj_cgroup ** objcgp,size_t size,gfp_t flags)716 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
717 						     struct list_lru *lru,
718 						     struct obj_cgroup **objcgp,
719 						     size_t size, gfp_t flags)
720 {
721 	flags &= gfp_allowed_mask;
722 
723 	might_alloc(flags);
724 
725 	if (should_failslab(s, flags))
726 		return NULL;
727 
728 	if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
729 		return NULL;
730 
731 	return s;
732 }
733 
slab_post_alloc_hook(struct kmem_cache * s,struct obj_cgroup * objcg,gfp_t flags,size_t size,void ** p,bool init)734 static inline void slab_post_alloc_hook(struct kmem_cache *s,
735 					struct obj_cgroup *objcg, gfp_t flags,
736 					size_t size, void **p, bool init)
737 {
738 	size_t i;
739 
740 	flags &= gfp_allowed_mask;
741 
742 	/*
743 	 * As memory initialization might be integrated into KASAN,
744 	 * kasan_slab_alloc and initialization memset must be
745 	 * kept together to avoid discrepancies in behavior.
746 	 *
747 	 * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
748 	 */
749 	for (i = 0; i < size; i++) {
750 		p[i] = kasan_slab_alloc(s, p[i], flags, init);
751 		if (p[i] && init && !kasan_has_integrated_init())
752 			memset(p[i], 0, s->object_size);
753 		kmemleak_alloc_recursive(p[i], s->object_size, 1,
754 					 s->flags, flags);
755 	}
756 
757 	memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
758 }
759 
760 #ifndef CONFIG_SLOB
761 /*
762  * The slab lists for all objects.
763  */
764 struct kmem_cache_node {
765 	spinlock_t list_lock;
766 
767 #ifdef CONFIG_SLAB
768 	struct list_head slabs_partial;	/* partial list first, better asm code */
769 	struct list_head slabs_full;
770 	struct list_head slabs_free;
771 	unsigned long total_slabs;	/* length of all slab lists */
772 	unsigned long free_slabs;	/* length of free slab list only */
773 	unsigned long free_objects;
774 	unsigned int free_limit;
775 	unsigned int colour_next;	/* Per-node cache coloring */
776 	struct array_cache *shared;	/* shared per node */
777 	struct alien_cache **alien;	/* on other nodes */
778 	unsigned long next_reap;	/* updated without locking */
779 	int free_touched;		/* updated without locking */
780 #endif
781 
782 #ifdef CONFIG_SLUB
783 	unsigned long nr_partial;
784 	struct list_head partial;
785 #ifdef CONFIG_SLUB_DEBUG
786 	atomic_long_t nr_slabs;
787 	atomic_long_t total_objects;
788 	struct list_head full;
789 #endif
790 #endif
791 
792 };
793 
get_node(struct kmem_cache * s,int node)794 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
795 {
796 	return s->node[node];
797 }
798 
799 /*
800  * Iterator over all nodes. The body will be executed for each node that has
801  * a kmem_cache_node structure allocated (which is true for all online nodes)
802  */
803 #define for_each_kmem_cache_node(__s, __node, __n) \
804 	for (__node = 0; __node < nr_node_ids; __node++) \
805 		 if ((__n = get_node(__s, __node)))
806 
807 #endif
808 
809 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
810 void dump_unreclaimable_slab(void);
811 #else
dump_unreclaimable_slab(void)812 static inline void dump_unreclaimable_slab(void)
813 {
814 }
815 #endif
816 
817 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
818 
819 #ifdef CONFIG_SLAB_FREELIST_RANDOM
820 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
821 			gfp_t gfp);
822 void cache_random_seq_destroy(struct kmem_cache *cachep);
823 #else
cache_random_seq_create(struct kmem_cache * cachep,unsigned int count,gfp_t gfp)824 static inline int cache_random_seq_create(struct kmem_cache *cachep,
825 					unsigned int count, gfp_t gfp)
826 {
827 	return 0;
828 }
cache_random_seq_destroy(struct kmem_cache * cachep)829 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
830 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
831 
slab_want_init_on_alloc(gfp_t flags,struct kmem_cache * c)832 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
833 {
834 	if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
835 				&init_on_alloc)) {
836 		if (c->ctor)
837 			return false;
838 		if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
839 			return flags & __GFP_ZERO;
840 		return true;
841 	}
842 	return flags & __GFP_ZERO;
843 }
844 
slab_want_init_on_free(struct kmem_cache * c)845 static inline bool slab_want_init_on_free(struct kmem_cache *c)
846 {
847 	if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
848 				&init_on_free))
849 		return !(c->ctor ||
850 			 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
851 	return false;
852 }
853 
854 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
855 void debugfs_slab_release(struct kmem_cache *);
856 #else
debugfs_slab_release(struct kmem_cache * s)857 static inline void debugfs_slab_release(struct kmem_cache *s) { }
858 #endif
859 
860 #ifdef CONFIG_PRINTK
861 #define KS_ADDRS_COUNT 16
862 struct kmem_obj_info {
863 	void *kp_ptr;
864 	struct slab *kp_slab;
865 	void *kp_objp;
866 	unsigned long kp_data_offset;
867 	struct kmem_cache *kp_slab_cache;
868 	void *kp_ret;
869 	void *kp_stack[KS_ADDRS_COUNT];
870 	void *kp_free_stack[KS_ADDRS_COUNT];
871 };
872 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
873 #endif
874 
875 #ifdef CONFIG_HAVE_HARDENED_USERCOPY_ALLOCATOR
876 void __check_heap_object(const void *ptr, unsigned long n,
877 			 const struct slab *slab, bool to_user);
878 #else
879 static inline
__check_heap_object(const void * ptr,unsigned long n,const struct slab * slab,bool to_user)880 void __check_heap_object(const void *ptr, unsigned long n,
881 			 const struct slab *slab, bool to_user)
882 {
883 }
884 #endif
885 
886 #endif /* MM_SLAB_H */
887