1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef MM_SLAB_H
3 #define MM_SLAB_H
4 /*
5 * Internal slab definitions
6 */
7 void __init kmem_cache_init(void);
8
9 #ifdef CONFIG_64BIT
10 # ifdef system_has_cmpxchg128
11 # define system_has_freelist_aba() system_has_cmpxchg128()
12 # define try_cmpxchg_freelist try_cmpxchg128
13 # endif
14 #define this_cpu_try_cmpxchg_freelist this_cpu_try_cmpxchg128
15 typedef u128 freelist_full_t;
16 #else /* CONFIG_64BIT */
17 # ifdef system_has_cmpxchg64
18 # define system_has_freelist_aba() system_has_cmpxchg64()
19 # define try_cmpxchg_freelist try_cmpxchg64
20 # endif
21 #define this_cpu_try_cmpxchg_freelist this_cpu_try_cmpxchg64
22 typedef u64 freelist_full_t;
23 #endif /* CONFIG_64BIT */
24
25 #if defined(system_has_freelist_aba) && !defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
26 #undef system_has_freelist_aba
27 #endif
28
29 /*
30 * Freelist pointer and counter to cmpxchg together, avoids the typical ABA
31 * problems with cmpxchg of just a pointer.
32 */
33 typedef union {
34 struct {
35 void *freelist;
36 unsigned long counter;
37 };
38 freelist_full_t full;
39 } freelist_aba_t;
40
41 /* Reuses the bits in struct page */
42 struct slab {
43 unsigned long __page_flags;
44
45 #if defined(CONFIG_SLAB)
46
47 struct kmem_cache *slab_cache;
48 union {
49 struct {
50 struct list_head slab_list;
51 void *freelist; /* array of free object indexes */
52 void *s_mem; /* first object */
53 };
54 struct rcu_head rcu_head;
55 };
56 unsigned int active;
57
58 #elif defined(CONFIG_SLUB)
59
60 struct kmem_cache *slab_cache;
61 union {
62 struct {
63 union {
64 struct list_head slab_list;
65 #ifdef CONFIG_SLUB_CPU_PARTIAL
66 struct {
67 struct slab *next;
68 int slabs; /* Nr of slabs left */
69 };
70 #endif
71 };
72 /* Double-word boundary */
73 union {
74 struct {
75 void *freelist; /* first free object */
76 union {
77 unsigned long counters;
78 struct {
79 unsigned inuse:16;
80 unsigned objects:15;
81 /*
82 * If slab debugging is enabled then the
83 * frozen bit can be reused to indicate
84 * that the slab was corrupted
85 */
86 unsigned frozen:1;
87 };
88 };
89 };
90 #ifdef system_has_freelist_aba
91 freelist_aba_t freelist_counter;
92 #endif
93 };
94 };
95 struct rcu_head rcu_head;
96 };
97 unsigned int __unused;
98
99 #else
100 #error "Unexpected slab allocator configured"
101 #endif
102
103 atomic_t __page_refcount;
104 #ifdef CONFIG_MEMCG
105 unsigned long memcg_data;
106 #endif
107 };
108
109 #define SLAB_MATCH(pg, sl) \
110 static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
111 SLAB_MATCH(flags, __page_flags);
112 SLAB_MATCH(compound_head, slab_cache); /* Ensure bit 0 is clear */
113 SLAB_MATCH(_refcount, __page_refcount);
114 #ifdef CONFIG_MEMCG
115 SLAB_MATCH(memcg_data, memcg_data);
116 #endif
117 #undef SLAB_MATCH
118 static_assert(sizeof(struct slab) <= sizeof(struct page));
119 #if defined(system_has_freelist_aba) && defined(CONFIG_SLUB)
120 static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t)));
121 #endif
122
123 /**
124 * folio_slab - Converts from folio to slab.
125 * @folio: The folio.
126 *
127 * Currently struct slab is a different representation of a folio where
128 * folio_test_slab() is true.
129 *
130 * Return: The slab which contains this folio.
131 */
132 #define folio_slab(folio) (_Generic((folio), \
133 const struct folio *: (const struct slab *)(folio), \
134 struct folio *: (struct slab *)(folio)))
135
136 /**
137 * slab_folio - The folio allocated for a slab
138 * @slab: The slab.
139 *
140 * Slabs are allocated as folios that contain the individual objects and are
141 * using some fields in the first struct page of the folio - those fields are
142 * now accessed by struct slab. It is occasionally necessary to convert back to
143 * a folio in order to communicate with the rest of the mm. Please use this
144 * helper function instead of casting yourself, as the implementation may change
145 * in the future.
146 */
147 #define slab_folio(s) (_Generic((s), \
148 const struct slab *: (const struct folio *)s, \
149 struct slab *: (struct folio *)s))
150
151 /**
152 * page_slab - Converts from first struct page to slab.
153 * @p: The first (either head of compound or single) page of slab.
154 *
155 * A temporary wrapper to convert struct page to struct slab in situations where
156 * we know the page is the compound head, or single order-0 page.
157 *
158 * Long-term ideally everything would work with struct slab directly or go
159 * through folio to struct slab.
160 *
161 * Return: The slab which contains this page
162 */
163 #define page_slab(p) (_Generic((p), \
164 const struct page *: (const struct slab *)(p), \
165 struct page *: (struct slab *)(p)))
166
167 /**
168 * slab_page - The first struct page allocated for a slab
169 * @slab: The slab.
170 *
171 * A convenience wrapper for converting slab to the first struct page of the
172 * underlying folio, to communicate with code not yet converted to folio or
173 * struct slab.
174 */
175 #define slab_page(s) folio_page(slab_folio(s), 0)
176
177 /*
178 * If network-based swap is enabled, sl*b must keep track of whether pages
179 * were allocated from pfmemalloc reserves.
180 */
slab_test_pfmemalloc(const struct slab * slab)181 static inline bool slab_test_pfmemalloc(const struct slab *slab)
182 {
183 return folio_test_active((struct folio *)slab_folio(slab));
184 }
185
slab_set_pfmemalloc(struct slab * slab)186 static inline void slab_set_pfmemalloc(struct slab *slab)
187 {
188 folio_set_active(slab_folio(slab));
189 }
190
slab_clear_pfmemalloc(struct slab * slab)191 static inline void slab_clear_pfmemalloc(struct slab *slab)
192 {
193 folio_clear_active(slab_folio(slab));
194 }
195
__slab_clear_pfmemalloc(struct slab * slab)196 static inline void __slab_clear_pfmemalloc(struct slab *slab)
197 {
198 __folio_clear_active(slab_folio(slab));
199 }
200
slab_address(const struct slab * slab)201 static inline void *slab_address(const struct slab *slab)
202 {
203 return folio_address(slab_folio(slab));
204 }
205
slab_nid(const struct slab * slab)206 static inline int slab_nid(const struct slab *slab)
207 {
208 return folio_nid(slab_folio(slab));
209 }
210
slab_pgdat(const struct slab * slab)211 static inline pg_data_t *slab_pgdat(const struct slab *slab)
212 {
213 return folio_pgdat(slab_folio(slab));
214 }
215
virt_to_slab(const void * addr)216 static inline struct slab *virt_to_slab(const void *addr)
217 {
218 struct folio *folio = virt_to_folio(addr);
219
220 if (!folio_test_slab(folio))
221 return NULL;
222
223 return folio_slab(folio);
224 }
225
slab_order(const struct slab * slab)226 static inline int slab_order(const struct slab *slab)
227 {
228 return folio_order((struct folio *)slab_folio(slab));
229 }
230
slab_size(const struct slab * slab)231 static inline size_t slab_size(const struct slab *slab)
232 {
233 return PAGE_SIZE << slab_order(slab);
234 }
235
236 #ifdef CONFIG_SLAB
237 #include <linux/slab_def.h>
238 #endif
239
240 #ifdef CONFIG_SLUB
241 #include <linux/slub_def.h>
242 #endif
243
244 #include <linux/memcontrol.h>
245 #include <linux/fault-inject.h>
246 #include <linux/kasan.h>
247 #include <linux/kmemleak.h>
248 #include <linux/random.h>
249 #include <linux/sched/mm.h>
250 #include <linux/list_lru.h>
251
252 /*
253 * State of the slab allocator.
254 *
255 * This is used to describe the states of the allocator during bootup.
256 * Allocators use this to gradually bootstrap themselves. Most allocators
257 * have the problem that the structures used for managing slab caches are
258 * allocated from slab caches themselves.
259 */
260 enum slab_state {
261 DOWN, /* No slab functionality yet */
262 PARTIAL, /* SLUB: kmem_cache_node available */
263 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
264 UP, /* Slab caches usable but not all extras yet */
265 FULL /* Everything is working */
266 };
267
268 extern enum slab_state slab_state;
269
270 /* The slab cache mutex protects the management structures during changes */
271 extern struct mutex slab_mutex;
272
273 /* The list of all slab caches on the system */
274 extern struct list_head slab_caches;
275
276 /* The slab cache that manages slab cache information */
277 extern struct kmem_cache *kmem_cache;
278
279 /* A table of kmalloc cache names and sizes */
280 extern const struct kmalloc_info_struct {
281 const char *name[NR_KMALLOC_TYPES];
282 unsigned int size;
283 } kmalloc_info[];
284
285 /* Kmalloc array related functions */
286 void setup_kmalloc_cache_index_table(void);
287 void create_kmalloc_caches(slab_flags_t);
288
289 /* Find the kmalloc slab corresponding for a certain size */
290 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags, unsigned long caller);
291
292 void *__kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags,
293 int node, size_t orig_size,
294 unsigned long caller);
295 void __kmem_cache_free(struct kmem_cache *s, void *x, unsigned long caller);
296
297 gfp_t kmalloc_fix_flags(gfp_t flags);
298
299 /* Functions provided by the slab allocators */
300 int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags);
301
302 void __init new_kmalloc_cache(int idx, enum kmalloc_cache_type type,
303 slab_flags_t flags);
304 extern void create_boot_cache(struct kmem_cache *, const char *name,
305 unsigned int size, slab_flags_t flags,
306 unsigned int useroffset, unsigned int usersize);
307
308 int slab_unmergeable(struct kmem_cache *s);
309 struct kmem_cache *find_mergeable(unsigned size, unsigned align,
310 slab_flags_t flags, const char *name, void (*ctor)(void *));
311 struct kmem_cache *
312 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
313 slab_flags_t flags, void (*ctor)(void *));
314
315 slab_flags_t kmem_cache_flags(unsigned int object_size,
316 slab_flags_t flags, const char *name);
317
is_kmalloc_cache(struct kmem_cache * s)318 static inline bool is_kmalloc_cache(struct kmem_cache *s)
319 {
320 return (s->flags & SLAB_KMALLOC);
321 }
322
323 /* Legal flag mask for kmem_cache_create(), for various configurations */
324 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \
325 SLAB_CACHE_DMA32 | SLAB_PANIC | \
326 SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS )
327
328 #if defined(CONFIG_DEBUG_SLAB)
329 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
330 #elif defined(CONFIG_SLUB_DEBUG)
331 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
332 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
333 #else
334 #define SLAB_DEBUG_FLAGS (0)
335 #endif
336
337 #if defined(CONFIG_SLAB)
338 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
339 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
340 SLAB_ACCOUNT | SLAB_NO_MERGE)
341 #elif defined(CONFIG_SLUB)
342 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
343 SLAB_TEMPORARY | SLAB_ACCOUNT | \
344 SLAB_NO_USER_FLAGS | SLAB_KMALLOC | SLAB_NO_MERGE)
345 #else
346 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE)
347 #endif
348
349 /* Common flags available with current configuration */
350 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
351
352 /* Common flags permitted for kmem_cache_create */
353 #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \
354 SLAB_RED_ZONE | \
355 SLAB_POISON | \
356 SLAB_STORE_USER | \
357 SLAB_TRACE | \
358 SLAB_CONSISTENCY_CHECKS | \
359 SLAB_MEM_SPREAD | \
360 SLAB_NOLEAKTRACE | \
361 SLAB_RECLAIM_ACCOUNT | \
362 SLAB_TEMPORARY | \
363 SLAB_ACCOUNT | \
364 SLAB_KMALLOC | \
365 SLAB_NO_MERGE | \
366 SLAB_NO_USER_FLAGS)
367
368 bool __kmem_cache_empty(struct kmem_cache *);
369 int __kmem_cache_shutdown(struct kmem_cache *);
370 void __kmem_cache_release(struct kmem_cache *);
371 int __kmem_cache_shrink(struct kmem_cache *);
372 void slab_kmem_cache_release(struct kmem_cache *);
373
374 struct seq_file;
375 struct file;
376
377 struct slabinfo {
378 unsigned long active_objs;
379 unsigned long num_objs;
380 unsigned long active_slabs;
381 unsigned long num_slabs;
382 unsigned long shared_avail;
383 unsigned int limit;
384 unsigned int batchcount;
385 unsigned int shared;
386 unsigned int objects_per_slab;
387 unsigned int cache_order;
388 };
389
390 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
391 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
392 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
393 size_t count, loff_t *ppos);
394
cache_vmstat_idx(struct kmem_cache * s)395 static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s)
396 {
397 return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
398 NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B;
399 }
400
401 #ifdef CONFIG_SLUB_DEBUG
402 #ifdef CONFIG_SLUB_DEBUG_ON
403 DECLARE_STATIC_KEY_TRUE(slub_debug_enabled);
404 #else
405 DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
406 #endif
407 extern void print_tracking(struct kmem_cache *s, void *object);
408 long validate_slab_cache(struct kmem_cache *s);
__slub_debug_enabled(void)409 static inline bool __slub_debug_enabled(void)
410 {
411 return static_branch_unlikely(&slub_debug_enabled);
412 }
413 #else
print_tracking(struct kmem_cache * s,void * object)414 static inline void print_tracking(struct kmem_cache *s, void *object)
415 {
416 }
__slub_debug_enabled(void)417 static inline bool __slub_debug_enabled(void)
418 {
419 return false;
420 }
421 #endif
422
423 /*
424 * Returns true if any of the specified slub_debug flags is enabled for the
425 * cache. Use only for flags parsed by setup_slub_debug() as it also enables
426 * the static key.
427 */
kmem_cache_debug_flags(struct kmem_cache * s,slab_flags_t flags)428 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
429 {
430 if (IS_ENABLED(CONFIG_SLUB_DEBUG))
431 VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
432 if (__slub_debug_enabled())
433 return s->flags & flags;
434 return false;
435 }
436
437 #ifdef CONFIG_MEMCG_KMEM
438 /*
439 * slab_objcgs - get the object cgroups vector associated with a slab
440 * @slab: a pointer to the slab struct
441 *
442 * Returns a pointer to the object cgroups vector associated with the slab,
443 * or NULL if no such vector has been associated yet.
444 */
slab_objcgs(struct slab * slab)445 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
446 {
447 unsigned long memcg_data = READ_ONCE(slab->memcg_data);
448
449 VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS),
450 slab_page(slab));
451 VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, slab_page(slab));
452
453 return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
454 }
455
456 int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s,
457 gfp_t gfp, bool new_slab);
458 void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
459 enum node_stat_item idx, int nr);
460
memcg_free_slab_cgroups(struct slab * slab)461 static inline void memcg_free_slab_cgroups(struct slab *slab)
462 {
463 kfree(slab_objcgs(slab));
464 slab->memcg_data = 0;
465 }
466
obj_full_size(struct kmem_cache * s)467 static inline size_t obj_full_size(struct kmem_cache *s)
468 {
469 /*
470 * For each accounted object there is an extra space which is used
471 * to store obj_cgroup membership. Charge it too.
472 */
473 return s->size + sizeof(struct obj_cgroup *);
474 }
475
476 /*
477 * Returns false if the allocation should fail.
478 */
memcg_slab_pre_alloc_hook(struct kmem_cache * s,struct list_lru * lru,struct obj_cgroup ** objcgp,size_t objects,gfp_t flags)479 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
480 struct list_lru *lru,
481 struct obj_cgroup **objcgp,
482 size_t objects, gfp_t flags)
483 {
484 struct obj_cgroup *objcg;
485
486 if (!memcg_kmem_online())
487 return true;
488
489 if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT))
490 return true;
491
492 objcg = get_obj_cgroup_from_current();
493 if (!objcg)
494 return true;
495
496 if (lru) {
497 int ret;
498 struct mem_cgroup *memcg;
499
500 memcg = get_mem_cgroup_from_objcg(objcg);
501 ret = memcg_list_lru_alloc(memcg, lru, flags);
502 css_put(&memcg->css);
503
504 if (ret)
505 goto out;
506 }
507
508 if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s)))
509 goto out;
510
511 *objcgp = objcg;
512 return true;
513 out:
514 obj_cgroup_put(objcg);
515 return false;
516 }
517
memcg_slab_post_alloc_hook(struct kmem_cache * s,struct obj_cgroup * objcg,gfp_t flags,size_t size,void ** p)518 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
519 struct obj_cgroup *objcg,
520 gfp_t flags, size_t size,
521 void **p)
522 {
523 struct slab *slab;
524 unsigned long off;
525 size_t i;
526
527 if (!memcg_kmem_online() || !objcg)
528 return;
529
530 for (i = 0; i < size; i++) {
531 if (likely(p[i])) {
532 slab = virt_to_slab(p[i]);
533
534 if (!slab_objcgs(slab) &&
535 memcg_alloc_slab_cgroups(slab, s, flags,
536 false)) {
537 obj_cgroup_uncharge(objcg, obj_full_size(s));
538 continue;
539 }
540
541 off = obj_to_index(s, slab, p[i]);
542 obj_cgroup_get(objcg);
543 slab_objcgs(slab)[off] = objcg;
544 mod_objcg_state(objcg, slab_pgdat(slab),
545 cache_vmstat_idx(s), obj_full_size(s));
546 } else {
547 obj_cgroup_uncharge(objcg, obj_full_size(s));
548 }
549 }
550 obj_cgroup_put(objcg);
551 }
552
memcg_slab_free_hook(struct kmem_cache * s,struct slab * slab,void ** p,int objects)553 static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
554 void **p, int objects)
555 {
556 struct obj_cgroup **objcgs;
557 int i;
558
559 if (!memcg_kmem_online())
560 return;
561
562 objcgs = slab_objcgs(slab);
563 if (!objcgs)
564 return;
565
566 for (i = 0; i < objects; i++) {
567 struct obj_cgroup *objcg;
568 unsigned int off;
569
570 off = obj_to_index(s, slab, p[i]);
571 objcg = objcgs[off];
572 if (!objcg)
573 continue;
574
575 objcgs[off] = NULL;
576 obj_cgroup_uncharge(objcg, obj_full_size(s));
577 mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s),
578 -obj_full_size(s));
579 obj_cgroup_put(objcg);
580 }
581 }
582
583 #else /* CONFIG_MEMCG_KMEM */
slab_objcgs(struct slab * slab)584 static inline struct obj_cgroup **slab_objcgs(struct slab *slab)
585 {
586 return NULL;
587 }
588
memcg_from_slab_obj(void * ptr)589 static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr)
590 {
591 return NULL;
592 }
593
memcg_alloc_slab_cgroups(struct slab * slab,struct kmem_cache * s,gfp_t gfp,bool new_slab)594 static inline int memcg_alloc_slab_cgroups(struct slab *slab,
595 struct kmem_cache *s, gfp_t gfp,
596 bool new_slab)
597 {
598 return 0;
599 }
600
memcg_free_slab_cgroups(struct slab * slab)601 static inline void memcg_free_slab_cgroups(struct slab *slab)
602 {
603 }
604
memcg_slab_pre_alloc_hook(struct kmem_cache * s,struct list_lru * lru,struct obj_cgroup ** objcgp,size_t objects,gfp_t flags)605 static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s,
606 struct list_lru *lru,
607 struct obj_cgroup **objcgp,
608 size_t objects, gfp_t flags)
609 {
610 return true;
611 }
612
memcg_slab_post_alloc_hook(struct kmem_cache * s,struct obj_cgroup * objcg,gfp_t flags,size_t size,void ** p)613 static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s,
614 struct obj_cgroup *objcg,
615 gfp_t flags, size_t size,
616 void **p)
617 {
618 }
619
memcg_slab_free_hook(struct kmem_cache * s,struct slab * slab,void ** p,int objects)620 static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
621 void **p, int objects)
622 {
623 }
624 #endif /* CONFIG_MEMCG_KMEM */
625
virt_to_cache(const void * obj)626 static inline struct kmem_cache *virt_to_cache(const void *obj)
627 {
628 struct slab *slab;
629
630 slab = virt_to_slab(obj);
631 if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n",
632 __func__))
633 return NULL;
634 return slab->slab_cache;
635 }
636
account_slab(struct slab * slab,int order,struct kmem_cache * s,gfp_t gfp)637 static __always_inline void account_slab(struct slab *slab, int order,
638 struct kmem_cache *s, gfp_t gfp)
639 {
640 if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT))
641 memcg_alloc_slab_cgroups(slab, s, gfp, true);
642
643 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
644 PAGE_SIZE << order);
645 }
646
unaccount_slab(struct slab * slab,int order,struct kmem_cache * s)647 static __always_inline void unaccount_slab(struct slab *slab, int order,
648 struct kmem_cache *s)
649 {
650 if (memcg_kmem_online())
651 memcg_free_slab_cgroups(slab);
652
653 mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
654 -(PAGE_SIZE << order));
655 }
656
cache_from_obj(struct kmem_cache * s,void * x)657 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
658 {
659 struct kmem_cache *cachep;
660
661 if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
662 !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
663 return s;
664
665 cachep = virt_to_cache(x);
666 if (WARN(cachep && cachep != s,
667 "%s: Wrong slab cache. %s but object is from %s\n",
668 __func__, s->name, cachep->name))
669 print_tracking(cachep, x);
670 return cachep;
671 }
672
673 void free_large_kmalloc(struct folio *folio, void *object);
674
675 size_t __ksize(const void *objp);
676
slab_ksize(const struct kmem_cache * s)677 static inline size_t slab_ksize(const struct kmem_cache *s)
678 {
679 #ifndef CONFIG_SLUB
680 return s->object_size;
681
682 #else /* CONFIG_SLUB */
683 # ifdef CONFIG_SLUB_DEBUG
684 /*
685 * Debugging requires use of the padding between object
686 * and whatever may come after it.
687 */
688 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
689 return s->object_size;
690 # endif
691 if (s->flags & SLAB_KASAN)
692 return s->object_size;
693 /*
694 * If we have the need to store the freelist pointer
695 * back there or track user information then we can
696 * only use the space before that information.
697 */
698 if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER))
699 return s->inuse;
700 /*
701 * Else we can use all the padding etc for the allocation
702 */
703 return s->size;
704 #endif
705 }
706
slab_pre_alloc_hook(struct kmem_cache * s,struct list_lru * lru,struct obj_cgroup ** objcgp,size_t size,gfp_t flags)707 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
708 struct list_lru *lru,
709 struct obj_cgroup **objcgp,
710 size_t size, gfp_t flags)
711 {
712 flags &= gfp_allowed_mask;
713
714 might_alloc(flags);
715
716 if (should_failslab(s, flags))
717 return NULL;
718
719 if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
720 return NULL;
721
722 return s;
723 }
724
slab_post_alloc_hook(struct kmem_cache * s,struct obj_cgroup * objcg,gfp_t flags,size_t size,void ** p,bool init,unsigned int orig_size)725 static inline void slab_post_alloc_hook(struct kmem_cache *s,
726 struct obj_cgroup *objcg, gfp_t flags,
727 size_t size, void **p, bool init,
728 unsigned int orig_size)
729 {
730 unsigned int zero_size = s->object_size;
731 bool kasan_init = init;
732 size_t i;
733
734 flags &= gfp_allowed_mask;
735
736 /*
737 * For kmalloc object, the allocated memory size(object_size) is likely
738 * larger than the requested size(orig_size). If redzone check is
739 * enabled for the extra space, don't zero it, as it will be redzoned
740 * soon. The redzone operation for this extra space could be seen as a
741 * replacement of current poisoning under certain debug option, and
742 * won't break other sanity checks.
743 */
744 if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
745 (s->flags & SLAB_KMALLOC))
746 zero_size = orig_size;
747
748 /*
749 * When slub_debug is enabled, avoid memory initialization integrated
750 * into KASAN and instead zero out the memory via the memset below with
751 * the proper size. Otherwise, KASAN might overwrite SLUB redzones and
752 * cause false-positive reports. This does not lead to a performance
753 * penalty on production builds, as slub_debug is not intended to be
754 * enabled there.
755 */
756 if (__slub_debug_enabled())
757 kasan_init = false;
758
759 /*
760 * As memory initialization might be integrated into KASAN,
761 * kasan_slab_alloc and initialization memset must be
762 * kept together to avoid discrepancies in behavior.
763 *
764 * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
765 */
766 for (i = 0; i < size; i++) {
767 p[i] = kasan_slab_alloc(s, p[i], flags, kasan_init);
768 if (p[i] && init && (!kasan_init || !kasan_has_integrated_init()))
769 memset(p[i], 0, zero_size);
770 kmemleak_alloc_recursive(p[i], s->object_size, 1,
771 s->flags, flags);
772 kmsan_slab_alloc(s, p[i], flags);
773 }
774
775 memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
776 }
777
778 /*
779 * The slab lists for all objects.
780 */
781 struct kmem_cache_node {
782 #ifdef CONFIG_SLAB
783 raw_spinlock_t list_lock;
784 struct list_head slabs_partial; /* partial list first, better asm code */
785 struct list_head slabs_full;
786 struct list_head slabs_free;
787 unsigned long total_slabs; /* length of all slab lists */
788 unsigned long free_slabs; /* length of free slab list only */
789 unsigned long free_objects;
790 unsigned int free_limit;
791 unsigned int colour_next; /* Per-node cache coloring */
792 struct array_cache *shared; /* shared per node */
793 struct alien_cache **alien; /* on other nodes */
794 unsigned long next_reap; /* updated without locking */
795 int free_touched; /* updated without locking */
796 #endif
797
798 #ifdef CONFIG_SLUB
799 spinlock_t list_lock;
800 unsigned long nr_partial;
801 struct list_head partial;
802 #ifdef CONFIG_SLUB_DEBUG
803 atomic_long_t nr_slabs;
804 atomic_long_t total_objects;
805 struct list_head full;
806 #endif
807 #endif
808
809 };
810
get_node(struct kmem_cache * s,int node)811 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
812 {
813 return s->node[node];
814 }
815
816 /*
817 * Iterator over all nodes. The body will be executed for each node that has
818 * a kmem_cache_node structure allocated (which is true for all online nodes)
819 */
820 #define for_each_kmem_cache_node(__s, __node, __n) \
821 for (__node = 0; __node < nr_node_ids; __node++) \
822 if ((__n = get_node(__s, __node)))
823
824
825 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
826 void dump_unreclaimable_slab(void);
827 #else
dump_unreclaimable_slab(void)828 static inline void dump_unreclaimable_slab(void)
829 {
830 }
831 #endif
832
833 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
834
835 #ifdef CONFIG_SLAB_FREELIST_RANDOM
836 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
837 gfp_t gfp);
838 void cache_random_seq_destroy(struct kmem_cache *cachep);
839 #else
cache_random_seq_create(struct kmem_cache * cachep,unsigned int count,gfp_t gfp)840 static inline int cache_random_seq_create(struct kmem_cache *cachep,
841 unsigned int count, gfp_t gfp)
842 {
843 return 0;
844 }
cache_random_seq_destroy(struct kmem_cache * cachep)845 static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
846 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
847
slab_want_init_on_alloc(gfp_t flags,struct kmem_cache * c)848 static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c)
849 {
850 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
851 &init_on_alloc)) {
852 if (c->ctor)
853 return false;
854 if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))
855 return flags & __GFP_ZERO;
856 return true;
857 }
858 return flags & __GFP_ZERO;
859 }
860
slab_want_init_on_free(struct kmem_cache * c)861 static inline bool slab_want_init_on_free(struct kmem_cache *c)
862 {
863 if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
864 &init_on_free))
865 return !(c->ctor ||
866 (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)));
867 return false;
868 }
869
870 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
871 void debugfs_slab_release(struct kmem_cache *);
872 #else
debugfs_slab_release(struct kmem_cache * s)873 static inline void debugfs_slab_release(struct kmem_cache *s) { }
874 #endif
875
876 #ifdef CONFIG_PRINTK
877 #define KS_ADDRS_COUNT 16
878 struct kmem_obj_info {
879 void *kp_ptr;
880 struct slab *kp_slab;
881 void *kp_objp;
882 unsigned long kp_data_offset;
883 struct kmem_cache *kp_slab_cache;
884 void *kp_ret;
885 void *kp_stack[KS_ADDRS_COUNT];
886 void *kp_free_stack[KS_ADDRS_COUNT];
887 };
888 void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
889 #endif
890
891 void __check_heap_object(const void *ptr, unsigned long n,
892 const struct slab *slab, bool to_user);
893
894 #ifdef CONFIG_SLUB_DEBUG
895 void skip_orig_size_check(struct kmem_cache *s, const void *object);
896 #endif
897
898 #endif /* MM_SLAB_H */
899