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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/mm/slab.c
4 * Written by Mark Hemment, 1996/97.
5 * (markhe@nextd.demon.co.uk)
6 *
7 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
8 *
9 * Major cleanup, different bufctl logic, per-cpu arrays
10 * (c) 2000 Manfred Spraul
11 *
12 * Cleanup, make the head arrays unconditional, preparation for NUMA
13 * (c) 2002 Manfred Spraul
14 *
15 * An implementation of the Slab Allocator as described in outline in;
16 * UNIX Internals: The New Frontiers by Uresh Vahalia
17 * Pub: Prentice Hall ISBN 0-13-101908-2
18 * or with a little more detail in;
19 * The Slab Allocator: An Object-Caching Kernel Memory Allocator
20 * Jeff Bonwick (Sun Microsystems).
21 * Presented at: USENIX Summer 1994 Technical Conference
22 *
23 * The memory is organized in caches, one cache for each object type.
24 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
25 * Each cache consists out of many slabs (they are small (usually one
26 * page long) and always contiguous), and each slab contains multiple
27 * initialized objects.
28 *
29 * This means, that your constructor is used only for newly allocated
30 * slabs and you must pass objects with the same initializations to
31 * kmem_cache_free.
32 *
33 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
34 * normal). If you need a special memory type, then must create a new
35 * cache for that memory type.
36 *
37 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
38 * full slabs with 0 free objects
39 * partial slabs
40 * empty slabs with no allocated objects
41 *
42 * If partial slabs exist, then new allocations come from these slabs,
43 * otherwise from empty slabs or new slabs are allocated.
44 *
45 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
46 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
47 *
48 * Each cache has a short per-cpu head array, most allocs
49 * and frees go into that array, and if that array overflows, then 1/2
50 * of the entries in the array are given back into the global cache.
51 * The head array is strictly LIFO and should improve the cache hit rates.
52 * On SMP, it additionally reduces the spinlock operations.
53 *
54 * The c_cpuarray may not be read with enabled local interrupts -
55 * it's changed with a smp_call_function().
56 *
57 * SMP synchronization:
58 * constructors and destructors are called without any locking.
59 * Several members in struct kmem_cache and struct slab never change, they
60 * are accessed without any locking.
61 * The per-cpu arrays are never accessed from the wrong cpu, no locking,
62 * and local interrupts are disabled so slab code is preempt-safe.
63 * The non-constant members are protected with a per-cache irq spinlock.
64 *
65 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
66 * in 2000 - many ideas in the current implementation are derived from
67 * his patch.
68 *
69 * Further notes from the original documentation:
70 *
71 * 11 April '97. Started multi-threading - markhe
72 * The global cache-chain is protected by the mutex 'slab_mutex'.
73 * The sem is only needed when accessing/extending the cache-chain, which
74 * can never happen inside an interrupt (kmem_cache_create(),
75 * kmem_cache_shrink() and kmem_cache_reap()).
76 *
77 * At present, each engine can be growing a cache. This should be blocked.
78 *
79 * 15 March 2005. NUMA slab allocator.
80 * Shai Fultheim <shai@scalex86.org>.
81 * Shobhit Dayal <shobhit@calsoftinc.com>
82 * Alok N Kataria <alokk@calsoftinc.com>
83 * Christoph Lameter <christoph@lameter.com>
84 *
85 * Modified the slab allocator to be node aware on NUMA systems.
86 * Each node has its own list of partial, free and full slabs.
87 * All object allocations for a node occur from node specific slab lists.
88 */
89
90#include <linux/__KEEPIDENTS__B.h>
91#include <linux/__KEEPIDENTS__C.h>
92#include <linux/__KEEPIDENTS__D.h>
93#include <linux/__KEEPIDENTS__E.h>
94#include <linux/__KEEPIDENTS__F.h>
95#include <linux/__KEEPIDENTS__G.h>
96#include <linux/__KEEPIDENTS__H.h>
97#include <linux/__KEEPIDENTS__I.h>
98#include <linux/__KEEPIDENTS__J.h>
99#include <linux/proc_fs.h>
100#include <linux/__KEEPIDENTS__BA.h>
101#include <linux/__KEEPIDENTS__BB.h>
102#include <linux/__KEEPIDENTS__BC.h>
103#include <linux/kfence.h>
104#include <linux/cpu.h>
105#include <linux/__KEEPIDENTS__BD.h>
106#include <linux/__KEEPIDENTS__BE.h>
107#include <linux/rcupdate.h>
108#include <linux/__KEEPIDENTS__BF.h>
109#include <linux/__KEEPIDENTS__BG.h>
110#include <linux/__KEEPIDENTS__BH.h>
111#include <linux/kmemleak.h>
112#include <linux/__KEEPIDENTS__BI.h>
113#include <linux/__KEEPIDENTS__BJ.h>
114#include <linux/__KEEPIDENTS__CA-__KEEPIDENTS__CB.h>
115#include <linux/__KEEPIDENTS__CC.h>
116#include <linux/reciprocal_div.h>
117#include <linux/debugobjects.h>
118#include <linux/__KEEPIDENTS__CD.h>
119#include <linux/__KEEPIDENTS__CE.h>
120#include <linux/__KEEPIDENTS__CF/task_stack.h>
121
122#include <net/__KEEPIDENTS__CG.h>
123
124#include <asm/cacheflush.h>
125#include <asm/tlbflush.h>
126#include <asm/page.h>
127
128#include <trace/events/kmem.h>
129
130#include "internal.h"
131
132#include "slab.h"
133
134/*
135 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
136 * 0 for faster, smaller code (especially in the critical paths).
137 *
138 * STATS - 1 to collect stats for /proc/slabinfo.
139 * 0 for faster, smaller code (especially in the critical paths).
140 *
141 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
142 */
143
144#ifdef CONFIG_DEBUG_SLAB
145#define DEBUG 1
146#define STATS 1
147#define FORCED_DEBUG 1
148#else
149#define DEBUG 0
150#define STATS 0
151#define FORCED_DEBUG 0
152#endif
153
154/* Shouldn't this be in a header file somewhere? */
155#define BYTES_PER_WORD sizeof(void *)
156#define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
157
158#ifndef ARCH_KMALLOC_FLAGS
159#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
160#endif
161
162#define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \
163 <= SLAB_OBJ_MIN_SIZE) ? 1 : 0)
164
165#if FREELIST_BYTE_INDEX
166typedef unsigned char freelist_idx_t;
167#else
168typedef unsigned short freelist_idx_t;
169#endif
170
171#define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1)
172
173/*
174 * struct array_cache
175 *
176 * Purpose:
177 * - LIFO ordering, to hand out cache-warm objects from _alloc
178 * - reduce the number of linked list operations
179 * - reduce spinlock operations
180 *
181 * The limit is stored in the per-cpu structure to reduce the data cache
182 * footprint.
183 *
184 */
185struct array_cache {
186 unsigned int avail;
187 unsigned int limit;
188 unsigned int batchcount;
189 unsigned int touched;
190 void *entry[]; /*
191 * Must have this definition in here for the proper
192 * alignment of array_cache. Also simplifies accessing
193 * the entries.
194 */
195};
196
197struct alien_cache {
198 spinlock_t lock;
199 struct array_cache ac;
200};
201
202/*
203 * Need this for bootstrapping a per node allocator.
204 */
205#define NUM_INIT_LISTS (2 * MAX_NUMNODES)
206static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS];
207#define CACHE_CACHE 0
208#define SIZE_NODE (MAX_NUMNODES)
209
210static int drain_freelist(struct kmem_cache *cache,
211 struct kmem_cache_node *n, int tofree);
212static void free_block(struct kmem_cache *cachep, void **objpp, int len,
213 int node, struct list_head *list);
214static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list);
215static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
216static void cache_reap(struct work_struct *unused);
217
218static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
219 void **list);
220static inline void fixup_slab_list(struct kmem_cache *cachep,
221 struct kmem_cache_node *n, struct page *page,
222 void **list);
223static int slab_early_init = 1;
224
225#define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node))
226
227static void kmem_cache_node_init(struct kmem_cache_node *parent)
228{
229 INIT_LIST_HEAD(&parent->slabs_full);
230 INIT_LIST_HEAD(&parent->slabs_partial);
231 INIT_LIST_HEAD(&parent->slabs_free);
232 parent->total_slabs = 0;
233 parent->free_slabs = 0;
234 parent->shared = NULL;
235 parent->alien = NULL;
236 parent->colour_next = 0;
237 spin_lock_init(&parent->list_lock);
238 parent->free_objects = 0;
239 parent->free_touched = 0;
240}
241
242#define MAKE_LIST(cachep, listp, slab, nodeid) \
243 do { \
244 INIT_LIST_HEAD(listp); \
245 list_splice(&get_node(cachep, nodeid)->slab, listp); \
246 } while (0)
247
248#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
249 do { \
250 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
251 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
252 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
253 } while (0)
254
255#define CFLGS_OBJFREELIST_SLAB ((slab_flags_t __force)0x40000000U)
256#define CFLGS_OFF_SLAB ((slab_flags_t __force)0x80000000U)
257#define OBJFREELIST_SLAB(x) ((x)->flags & CFLGS_OBJFREELIST_SLAB)
258#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
259
260#define BATCHREFILL_LIMIT 16
261/*
262 * Optimization question: fewer reaps means less probability for unnecessary
263 * cpucache drain/refill cycles.
264 *
265 * OTOH the cpuarrays can contain lots of objects,
266 * which could lock up otherwise freeable slabs.
267 */
268#define REAPTIMEOUT_AC (2*HZ)
269#define REAPTIMEOUT_NODE (4*HZ)
270
271#if STATS
272#define STATS_INC_ACTIVE(x) ((x)->num_active++)
273#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
274#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
275#define STATS_INC_GROWN(x) ((x)->grown++)
276#define STATS_ADD_REAPED(x, y) ((x)->reaped += (y))
277#define STATS_SET_HIGH(x) \
278 do { \
279 if ((x)->num_active > (x)->high_mark) \
280 (x)->high_mark = (x)->num_active; \
281 } while (0)
282#define STATS_INC_ERR(x) ((x)->errors++)
283#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
284#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
285#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
286#define STATS_SET_FREEABLE(x, i) \
287 do { \
288 if ((x)->max_freeable < i) \
289 (x)->max_freeable = i; \
290 } while (0)
291#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
292#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
293#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
294#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
295#else
296#define STATS_INC_ACTIVE(x) do { } while (0)
297#define STATS_DEC_ACTIVE(x) do { } while (0)
298#define STATS_INC_ALLOCED(x) do { } while (0)
299#define STATS_INC_GROWN(x) do { } while (0)
300#define STATS_ADD_REAPED(x, y) do { (void)(y); } while (0)
301#define STATS_SET_HIGH(x) do { } while (0)
302#define STATS_INC_ERR(x) do { } while (0)
303#define STATS_INC_NODEALLOCS(x) do { } while (0)
304#define STATS_INC_NODEFREES(x) do { } while (0)
305#define STATS_INC_ACOVERFLOW(x) do { } while (0)
306#define STATS_SET_FREEABLE(x, i) do { } while (0)
307#define STATS_INC_ALLOCHIT(x) do { } while (0)
308#define STATS_INC_ALLOCMISS(x) do { } while (0)
309#define STATS_INC_FREEHIT(x) do { } while (0)
310#define STATS_INC_FREEMISS(x) do { } while (0)
311#endif
312
313#if DEBUG
314
315/*
316 * memory layout of objects:
317 * 0 : objp
318 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
319 * the end of an object is aligned with the end of the real
320 * allocation. Catches writes behind the end of the allocation.
321 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
322 * redzone word.
323 * cachep->obj_offset: The real object.
324 * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
325 * cachep->size - 1* BYTES_PER_WORD: last caller address
326 * [BYTES_PER_WORD long]
327 */
328static int obj_offset(struct kmem_cache *cachep)
329{
330 return cachep->obj_offset;
331}
332
333static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
334{
335 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
336 return (unsigned long long *) (objp + obj_offset(cachep) -
337 sizeof(unsigned long long));
338}
339
340static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
341{
342 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
343 if (cachep->flags & SLAB_STORE_USER)
344 return (unsigned long long *)(objp + cachep->size -
345 sizeof(unsigned long long) -
346 REDZONE_ALIGN);
347 return (unsigned long long *) (objp + cachep->size -
348 sizeof(unsigned long long));
349}
350
351static void **dbg_userword(struct kmem_cache *cachep, void *objp)
352{
353 BUG_ON(!(cachep->flags & SLAB_STORE_USER));
354 return (void **)(objp + cachep->size - BYTES_PER_WORD);
355}
356
357#else
358
359#define obj_offset(x) 0
360#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
361#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
362#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
363
364#endif
365
366/*
367 * Do not go above this order unless 0 objects fit into the slab or
368 * overridden on the command line.
369 */
370#define SLAB_MAX_ORDER_HI 1
371#define SLAB_MAX_ORDER_LO 0
372static int slab_max_order = SLAB_MAX_ORDER_LO;
373static bool slab_max_order_set __initdata;
374
375static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
376 unsigned int idx)
377{
378 return page->s_mem + cache->size * idx;
379}
380
381#define BOOT_CPUCACHE_ENTRIES 1
382/* internal cache of cache description objs */
383static struct kmem_cache kmem_cache_boot = {
384 .batchcount = 1,
385 .limit = BOOT_CPUCACHE_ENTRIES,
386 .shared = 1,
387 .size = sizeof(struct kmem_cache),
388 .name = "kmem_cache",
389};
390
391static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
392
393static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
394{
395 return this_cpu_ptr(cachep->cpu_cache);
396}
397
398/*
399 * Calculate the number of objects and left-over bytes for a given buffer size.
400 */
401static unsigned int cache_estimate(unsigned long gfporder, size_t buffer_size,
402 slab_flags_t flags, size_t *left_over)
403{
404 unsigned int num;
405 size_t slab_size = PAGE_SIZE << gfporder;
406
407 /*
408 * The slab management structure can be either off the slab or
409 * on it. For the latter case, the memory allocated for a
410 * slab is used for:
411 *
412 * - @buffer_size bytes for each object
413 * - One freelist_idx_t for each object
414 *
415 * We don't need to consider alignment of freelist because
416 * freelist will be at the end of slab page. The objects will be
417 * at the correct alignment.
418 *
419 * If the slab management structure is off the slab, then the
420 * alignment will already be calculated into the size. Because
421 * the slabs are all pages aligned, the objects will be at the
422 * correct alignment when allocated.
423 */
424 if (flags & (CFLGS_OBJFREELIST_SLAB | CFLGS_OFF_SLAB)) {
425 num = slab_size / buffer_size;
426 *left_over = slab_size % buffer_size;
427 } else {
428 num = slab_size / (buffer_size + sizeof(freelist_idx_t));
429 *left_over = slab_size %
430 (buffer_size + sizeof(freelist_idx_t));
431 }
432
433 return num;
434}
435
436#if DEBUG
437#define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
438
439static void __slab_error(const char *function, struct kmem_cache *cachep,
440 char *msg)
441{
442 pr_err("slab error in %s(): cache `%s': %s\n",
443 function, cachep->name, msg);
444 dump_stack();
445 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
446}
447#endif
448
449/*
450 * By default on NUMA we use alien caches to stage the freeing of
451 * objects allocated from other nodes. This causes massive memory
452 * inefficiencies when using fake NUMA setup to split memory into a
453 * large number of small nodes, so it can be disabled on the command
454 * line
455 */
456
457static int use_alien_caches __read_mostly = 1;
458static int __init noaliencache_setup(char *s)
459{
460 use_alien_caches = 0;
461 return 1;
462}
463__setup("noaliencache", noaliencache_setup);
464
465static int __init slab_max_order_setup(char *str)
466{
467 get_option(&str, &slab_max_order);
468 slab_max_order = slab_max_order < 0 ? 0 :
469 min(slab_max_order, MAX_ORDER - 1);
470 slab_max_order_set = true;
471
472 return 1;
473}
474__setup("slab_max_order=", slab_max_order_setup);
475
476#ifdef CONFIG_NUMA
477/*
478 * Special reaping functions for NUMA systems called from cache_reap().
479 * These take care of doing round robin flushing of alien caches (containing
480 * objects freed on different nodes from which they were allocated) and the
481 * flushing of remote pcps by calling drain_node_pages.
482 */
483static DEFINE_PER_CPU(unsigned long, slab_reap_node);
484
485static void init_reap_node(int cpu)
486{
487 per_cpu(slab_reap_node, cpu) = next_node_in(cpu_to_mem(cpu),
488 node_online_map);
489}
490
491static void next_reap_node(void)
492{
493 int node = __this_cpu_read(slab_reap_node);
494
495 node = next_node_in(node, node_online_map);
496 __this_cpu_write(slab_reap_node, node);
497}
498
499#else
500#define init_reap_node(cpu) do { } while (0)
501#define next_reap_node(void) do { } while (0)
502#endif
503
504/*
505 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
506 * via the workqueue/eventd.
507 * Add the CPU number into the expiration time to minimize the possibility of
508 * the CPUs getting into lockstep and contending for the global cache chain
509 * lock.
510 */
511static void start_cpu_timer(int cpu)
512{
513 struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu);
514
515 if (reap_work->work.func == NULL) {
516 init_reap_node(cpu);
517 INIT_DEFERRABLE_WORK(reap_work, cache_reap);
518 schedule_delayed_work_on(cpu, reap_work,
519 __round_jiffies_relative(HZ, cpu));
520 }
521}
522
523static void init_arraycache(struct array_cache *ac, int limit, int batch)
524{
525 if (ac) {
526 ac->avail = 0;
527 ac->limit = limit;
528 ac->batchcount = batch;
529 ac->touched = 0;
530 }
531}
532
533static struct array_cache *alloc_arraycache(int node, int entries,
534 int batchcount, gfp_t gfp)
535{
536 size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache);
537 struct array_cache *ac = NULL;
538
539 ac = kmalloc_node(memsize, gfp, node);
540 /*
541 * The array_cache structures contain pointers to free object.
542 * However, when such objects are allocated or transferred to another
543 * cache the pointers are not cleared and they could be counted as
544 * valid references during a kmemleak scan. Therefore, kmemleak must
545 * not scan such objects.
546 */
547 kmemleak_no_scan(ac);
548 init_arraycache(ac, entries, batchcount);
549 return ac;
550}
551
552static noinline void cache_free_pfmemalloc(struct kmem_cache *cachep,
553 struct page *page, void *objp)
554{
555 struct kmem_cache_node *n;
556 int page_node;
557 LIST_HEAD(list);
558
559 page_node = page_to_nid(page);
560 n = get_node(cachep, page_node);
561
562 spin_lock(&n->list_lock);
563 free_block(cachep, &objp, 1, page_node, &list);
564 spin_unlock(&n->list_lock);
565
566 slabs_destroy(cachep, &list);
567}
568
569/*
570 * Transfer objects in one arraycache to another.
571 * Locking must be handled by the caller.
572 *
573 * Return the number of entries transferred.
574 */
575static int transfer_objects(struct array_cache *to,
576 struct array_cache *from, unsigned int max)
577{
578 /* Figure out how many entries to transfer */
579 int nr = min3(from->avail, max, to->limit - to->avail);
580
581 if (!nr)
582 return 0;
583
584 memcpy(to->entry + to->avail, from->entry + from->avail - nr,
585 sizeof(void *) *nr);
586
587 from->avail -= nr;
588 to->avail += nr;
589 return nr;
590}
591
592/* &alien->lock must be held by alien callers. */
593static __always_inline void __free_one(struct array_cache *ac, void *objp)
594{
595 /* Avoid trivial double-free. */
596 if (IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
597 WARN_ON_ONCE(ac->avail > 0 && ac->entry[ac->avail - 1] == objp))
598 return;
599 ac->entry[ac->avail++] = objp;
600}
601
602#ifndef CONFIG_NUMA
603
604#define drain_alien_cache(cachep, alien) do { } while (0)
605#define reap_alien(cachep, n) do { } while (0)
606
607static inline struct alien_cache **alloc_alien_cache(int node,
608 int limit, gfp_t gfp)
609{
610 return NULL;
611}
612
613static inline void free_alien_cache(struct alien_cache **ac_ptr)
614{
615}
616
617static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
618{
619 return 0;
620}
621
622static inline void *alternate_node_alloc(struct kmem_cache *cachep,
623 gfp_t flags)
624{
625 return NULL;
626}
627
628static inline void *____cache_alloc_node(struct kmem_cache *cachep,
629 gfp_t flags, int nodeid)
630{
631 return NULL;
632}
633
634static inline gfp_t gfp_exact_node(gfp_t flags)
635{
636 return flags & ~__GFP_NOFAIL;
637}
638
639#else /* CONFIG_NUMA */
640
641static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
642static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
643
644static struct alien_cache *__alloc_alien_cache(int node, int entries,
645 int batch, gfp_t gfp)
646{
647 size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache);
648 struct alien_cache *alc = NULL;
649
650 alc = kmalloc_node(memsize, gfp, node);
651 if (alc) {
652 kmemleak_no_scan(alc);
653 init_arraycache(&alc->ac, entries, batch);
654 spin_lock_init(&alc->lock);
655 }
656 return alc;
657}
658
659static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
660{
661 struct alien_cache **alc_ptr;
662 int i;
663
664 if (limit > 1)
665 limit = 12;
666 alc_ptr = kcalloc_node(nr_node_ids, sizeof(void *), gfp, node);
667 if (!alc_ptr)
668 return NULL;
669
670 for_each_node(i) {
671 if (i == node || !node_online(i))
672 continue;
673 alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp);
674 if (!alc_ptr[i]) {
675 for (i--; i >= 0; i--)
676 kfree(alc_ptr[i]);
677 kfree(alc_ptr);
678 return NULL;
679 }
680 }
681 return alc_ptr;
682}
683
684static void free_alien_cache(struct alien_cache **alc_ptr)
685{
686 int i;
687
688 if (!alc_ptr)
689 return;
690 for_each_node(i)
691 kfree(alc_ptr[i]);
692 kfree(alc_ptr);
693}
694
695static void __drain_alien_cache(struct kmem_cache *cachep,
696 struct array_cache *ac, int node,
697 struct list_head *list)
698{
699 struct kmem_cache_node *n = get_node(cachep, node);
700
701 if (ac->avail) {
702 spin_lock(&n->list_lock);
703 /*
704 * Stuff objects into the remote nodes shared array first.
705 * That way we could avoid the overhead of putting the objects
706 * into the free lists and getting them back later.
707 */
708 if (n->shared)
709 transfer_objects(n->shared, ac, ac->limit);
710
711 free_block(cachep, ac->entry, ac->avail, node, list);
712 ac->avail = 0;
713 spin_unlock(&n->list_lock);
714 }
715}
716
717/*
718 * Called from cache_reap() to regularly drain alien caches round robin.
719 */
720static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n)
721{
722 int node = __this_cpu_read(slab_reap_node);
723
724 if (n->alien) {
725 struct alien_cache *alc = n->alien[node];
726 struct array_cache *ac;
727
728 if (alc) {
729 ac = &alc->ac;
730 if (ac->avail && spin_trylock_irq(&alc->lock)) {
731 LIST_HEAD(list);
732
733 __drain_alien_cache(cachep, ac, node, &list);
734 spin_unlock_irq(&alc->lock);
735 slabs_destroy(cachep, &list);
736 }
737 }
738 }
739}
740
741static void drain_alien_cache(struct kmem_cache *cachep,
742 struct alien_cache **alien)
743{
744 int i = 0;
745 struct alien_cache *alc;
746 struct array_cache *ac;
747 unsigned long flags;
748
749 for_each_online_node(i) {
750 alc = alien[i];
751 if (alc) {
752 LIST_HEAD(list);
753
754 ac = &alc->ac;
755 spin_lock_irqsave(&alc->lock, flags);
756 __drain_alien_cache(cachep, ac, i, &list);
757 spin_unlock_irqrestore(&alc->lock, flags);
758 slabs_destroy(cachep, &list);
759 }
760 }
761}
762
763static int __cache_free_alien(struct kmem_cache *cachep, void *objp,
764 int node, int page_node)
765{
766 struct kmem_cache_node *n;
767 struct alien_cache *alien = NULL;
768 struct array_cache *ac;
769 LIST_HEAD(list);
770
771 n = get_node(cachep, node);
772 STATS_INC_NODEFREES(cachep);
773 if (n->alien && n->alien[page_node]) {
774 alien = n->alien[page_node];
775 ac = &alien->ac;
776 spin_lock(&alien->lock);
777 if (unlikely(ac->avail == ac->limit)) {
778 STATS_INC_ACOVERFLOW(cachep);
779 __drain_alien_cache(cachep, ac, page_node, &list);
780 }
781 __free_one(ac, objp);
782 spin_unlock(&alien->lock);
783 slabs_destroy(cachep, &list);
784 } else {
785 n = get_node(cachep, page_node);
786 spin_lock(&n->list_lock);
787 free_block(cachep, &objp, 1, page_node, &list);
788 spin_unlock(&n->list_lock);
789 slabs_destroy(cachep, &list);
790 }
791 return 1;
792}
793
794static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
795{
796 int page_node = page_to_nid(virt_to_page(objp));
797 int node = numa_mem_id();
798 /*
799 * Make sure we are not freeing a object from another node to the array
800 * cache on this cpu.
801 */
802 if (likely(node == page_node))
803 return 0;
804
805 return __cache_free_alien(cachep, objp, node, page_node);
806}
807
808/*
809 * Construct gfp mask to allocate from a specific node but do not reclaim or
810 * warn about failures.
811 */
812static inline gfp_t gfp_exact_node(gfp_t flags)
813{
814 return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~(__GFP_RECLAIM|__GFP_NOFAIL);
815}
816#endif
817
818static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp)
819{
820 struct kmem_cache_node *n;
821
822 /*
823 * Set up the kmem_cache_node for cpu before we can
824 * begin anything. Make sure some other cpu on this
825 * node has not already allocated this
826 */
827 n = get_node(cachep, node);
828 if (n) {
829 spin_lock_irq(&n->list_lock);
830 n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount +
831 cachep->num;
832 spin_unlock_irq(&n->list_lock);
833
834 return 0;
835 }
836
837 n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node);
838 if (!n)
839 return -ENOMEM;
840
841 kmem_cache_node_init(n);
842 n->next_reap = jiffies + REAPTIMEOUT_NODE +
843 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
844
845 n->free_limit =
846 (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num;
847
848 /*
849 * The kmem_cache_nodes don't come and go as CPUs
850 * come and go. slab_mutex is sufficient
851 * protection here.
852 */
853 cachep->node[node] = n;
854
855 return 0;
856}
857
858#if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP)
859/*
860 * Allocates and initializes node for a node on each slab cache, used for
861 * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
862 * will be allocated off-node since memory is not yet online for the new node.
863 * When hotplugging memory or a cpu, existing node are not replaced if
864 * already in use.
865 *
866 * Must hold slab_mutex.
867 */
868static int init_cache_node_node(int node)
869{
870 int ret;
871 struct kmem_cache *cachep;
872
873 list_for_each_entry(cachep, &slab_caches, list) {
874 ret = init_cache_node(cachep, node, GFP_KERNEL);
875 if (ret)
876 return ret;
877 }
878
879 return 0;
880}
881#endif
882
883static int setup_kmem_cache_node(struct kmem_cache *cachep,
884 int node, gfp_t gfp, bool force_change)
885{
886 int ret = -ENOMEM;
887 struct kmem_cache_node *n;
888 struct array_cache *old_shared = NULL;
889 struct array_cache *new_shared = NULL;
890 struct alien_cache **new_alien = NULL;
891 LIST_HEAD(list);
892
893 if (use_alien_caches) {
894 new_alien = alloc_alien_cache(node, cachep->limit, gfp);
895 if (!new_alien)
896 goto fail;
897 }
898
899 if (cachep->shared) {
900 new_shared = alloc_arraycache(node,
901 cachep->shared * cachep->batchcount, 0xbaadf00d, gfp);
902 if (!new_shared)
903 goto fail;
904 }
905
906 ret = init_cache_node(cachep, node, gfp);
907 if (ret)
908 goto fail;
909
910 n = get_node(cachep, node);
911 spin_lock_irq(&n->list_lock);
912 if (n->shared && force_change) {
913 free_block(cachep, n->shared->entry,
914 n->shared->avail, node, &list);
915 n->shared->avail = 0;
916 }
917
918 if (!n->shared || force_change) {
919 old_shared = n->shared;
920 n->shared = new_shared;
921 new_shared = NULL;
922 }
923
924 if (!n->alien) {
925 n->alien = new_alien;
926 new_alien = NULL;
927 }
928
929 spin_unlock_irq(&n->list_lock);
930 slabs_destroy(cachep, &list);
931
932 /*
933 * To protect lockless access to n->shared during irq disabled context.
934 * If n->shared isn't NULL in irq disabled context, accessing to it is
935 * guaranteed to be valid until irq is re-enabled, because it will be
936 * freed after synchronize_rcu().
937 */
938 if (old_shared && force_change)
939 synchronize_rcu();
940
941fail:
942 kfree(old_shared);
943 kfree(new_shared);
944 free_alien_cache(new_alien);
945
946 return ret;
947}
948
949#ifdef CONFIG_SMP
950
951static void cpuup_canceled(long cpu)
952{
953 struct kmem_cache *cachep;
954 struct kmem_cache_node *n = NULL;
955 int node = cpu_to_mem(cpu);
956 const struct cpumask *mask = cpumask_of_node(node);
957
958 list_for_each_entry(cachep, &slab_caches, list) {
959 struct array_cache *nc;
960 struct array_cache *shared;
961 struct alien_cache **alien;
962 LIST_HEAD(list);
963
964 n = get_node(cachep, node);
965 if (!n)
966 continue;
967
968 spin_lock_irq(&n->list_lock);
969
970 /* Free limit for this kmem_cache_node */
971 n->free_limit -= cachep->batchcount;
972
973 /* cpu is dead; no one can alloc from it. */
974 nc = per_cpu_ptr(cachep->cpu_cache, cpu);
975 free_block(cachep, nc->entry, nc->avail, node, &list);
976 nc->avail = 0;
977
978 if (!cpumask_empty(mask)) {
979 spin_unlock_irq(&n->list_lock);
980 goto free_slab;
981 }
982
983 shared = n->shared;
984 if (shared) {
985 free_block(cachep, shared->entry,
986 shared->avail, node, &list);
987 n->shared = NULL;
988 }
989
990 alien = n->alien;
991 n->alien = NULL;
992
993 spin_unlock_irq(&n->list_lock);
994
995 kfree(shared);
996 if (alien) {
997 drain_alien_cache(cachep, alien);
998 free_alien_cache(alien);
999 }
1000
1001free_slab:
1002 slabs_destroy(cachep, &list);
1003 }
1004 /*
1005 * In the previous loop, all the objects were freed to
1006 * the respective cache's slabs, now we can go ahead and
1007 * shrink each nodelist to its limit.
1008 */
1009 list_for_each_entry(cachep, &slab_caches, list) {
1010 n = get_node(cachep, node);
1011 if (!n)
1012 continue;
1013 drain_freelist(cachep, n, INT_MAX);
1014 }
1015}
1016
1017static int cpuup_prepare(long cpu)
1018{
1019 struct kmem_cache *cachep;
1020 int node = cpu_to_mem(cpu);
1021 int err;
1022
1023 /*
1024 * We need to do this right in the beginning since
1025 * alloc_arraycache's are going to use this list.
1026 * kmalloc_node allows us to add the slab to the right
1027 * kmem_cache_node and not this cpu's kmem_cache_node
1028 */
1029 err = init_cache_node_node(node);
1030 if (err < 0)
1031 goto bad;
1032
1033 /*
1034 * Now we can go ahead with allocating the shared arrays and
1035 * array caches
1036 */
1037 list_for_each_entry(cachep, &slab_caches, list) {
1038 err = setup_kmem_cache_node(cachep, node, GFP_KERNEL, false);
1039 if (err)
1040 goto bad;
1041 }
1042
1043 return 0;
1044bad:
1045 cpuup_canceled(cpu);
1046 return -ENOMEM;
1047}
1048
1049int slab_prepare_cpu(unsigned int cpu)
1050{
1051 int err;
1052
1053 mutex_lock(&slab_mutex);
1054 err = cpuup_prepare(cpu);
1055 mutex_unlock(&slab_mutex);
1056 return err;
1057}
1058
1059/*
1060 * This is called for a failed online attempt and for a successful
1061 * offline.
1062 *
1063 * Even if all the cpus of a node are down, we don't free the
1064 * kmem_cache_node of any cache. This to avoid a race between cpu_down, and
1065 * a kmalloc allocation from another cpu for memory from the node of
1066 * the cpu going down. The kmem_cache_node structure is usually allocated from
1067 * kmem_cache_create() and gets destroyed at kmem_cache_destroy().
1068 */
1069int slab_dead_cpu(unsigned int cpu)
1070{
1071 mutex_lock(&slab_mutex);
1072 cpuup_canceled(cpu);
1073 mutex_unlock(&slab_mutex);
1074 return 0;
1075}
1076#endif
1077
1078static int slab_online_cpu(unsigned int cpu)
1079{
1080 start_cpu_timer(cpu);
1081 return 0;
1082}
1083
1084static int slab_offline_cpu(unsigned int cpu)
1085{
1086 /*
1087 * Shutdown cache reaper. Note that the slab_mutex is held so
1088 * that if cache_reap() is invoked it cannot do anything
1089 * expensive but will only modify reap_work and reschedule the
1090 * timer.
1091 */
1092 cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu));
1093 /* Now the cache_reaper is guaranteed to be not running. */
1094 per_cpu(slab_reap_work, cpu).work.func = NULL;
1095 return 0;
1096}
1097
1098#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
1099/*
1100 * Drains freelist for a node on each slab cache, used for memory hot-remove.
1101 * Returns -EBUSY if all objects cannot be drained so that the node is not
1102 * removed.
1103 *
1104 * Must hold slab_mutex.
1105 */
1106static int __meminit drain_cache_node_node(int node)
1107{
1108 struct kmem_cache *cachep;
1109 int ret = 0;
1110
1111 list_for_each_entry(cachep, &slab_caches, list) {
1112 struct kmem_cache_node *n;
1113
1114 n = get_node(cachep, node);
1115 if (!n)
1116 continue;
1117
1118 drain_freelist(cachep, n, INT_MAX);
1119
1120 if (!list_empty(&n->slabs_full) ||
1121 !list_empty(&n->slabs_partial)) {
1122 ret = -EBUSY;
1123 break;
1124 }
1125 }
1126 return ret;
1127}
1128
1129static int __meminit slab_memory_callback(struct notifier_block *self,
1130 unsigned long action, void *arg)
1131{
1132 struct memory_notify *mnb = arg;
1133 int ret = 0;
1134 int nid;
1135
1136 nid = mnb->status_change_nid;
1137 if (nid < 0)
1138 goto out;
1139
1140 switch (action) {
1141 case MEM_GOING_ONLINE:
1142 mutex_lock(&slab_mutex);
1143 ret = init_cache_node_node(nid);
1144 mutex_unlock(&slab_mutex);
1145 break;
1146 case MEM_GOING_OFFLINE:
1147 mutex_lock(&slab_mutex);
1148 ret = drain_cache_node_node(nid);
1149 mutex_unlock(&slab_mutex);
1150 break;
1151 case MEM_ONLINE:
1152 case MEM_OFFLINE:
1153 case MEM_CANCEL_ONLINE:
1154 case MEM_CANCEL_OFFLINE:
1155 break;
1156 }
1157out:
1158 return notifier_from_errno(ret);
1159}
1160#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
1161
1162/*
1163 * swap the static kmem_cache_node with kmalloced memory
1164 */
1165static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list,
1166 int nodeid)
1167{
1168 struct kmem_cache_node *ptr;
1169
1170 ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid);
1171 BUG_ON(!ptr);
1172
1173 memcpy(ptr, list, sizeof(struct kmem_cache_node));
1174 /*
1175 * Do not assume that spinlocks can be initialized via memcpy:
1176 */
1177 spin_lock_init(&ptr->list_lock);
1178
1179 MAKE_ALL_LISTS(cachep, ptr, nodeid);
1180 cachep->node[nodeid] = ptr;
1181}
1182
1183/*
1184 * For setting up all the kmem_cache_node for cache whose buffer_size is same as
1185 * size of kmem_cache_node.
1186 */
1187static void __init set_up_node(struct kmem_cache *cachep, int index)
1188{
1189 int node;
1190
1191 for_each_online_node(node) {
1192 cachep->node[node] = &init_kmem_cache_node[index + node];
1193 cachep->node[node]->next_reap = jiffies +
1194 REAPTIMEOUT_NODE +
1195 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
1196 }
1197}
1198
1199/*
1200 * Initialisation. Called after the page allocator have been initialised and
1201 * before smp_init().
1202 */
1203void __init kmem_cache_init(void)
1204{
1205 int i;
1206
1207 kmem_cache = &kmem_cache_boot;
1208
1209 if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1)
1210 use_alien_caches = 0;
1211
1212 for (i = 0; i < NUM_INIT_LISTS; i++)
1213 kmem_cache_node_init(&init_kmem_cache_node[i]);
1214
1215 /*
1216 * Fragmentation resistance on low memory - only use bigger
1217 * page orders on machines with more than 32MB of memory if
1218 * not overridden on the command line.
1219 */
1220 if (!slab_max_order_set && totalram_pages() > (32 << 20) >> PAGE_SHIFT)
1221 slab_max_order = SLAB_MAX_ORDER_HI;
1222
1223 /* Bootstrap is tricky, because several objects are allocated
1224 * from caches that do not exist yet:
1225 * 1) initialize the kmem_cache cache: it contains the struct
1226 * kmem_cache structures of all caches, except kmem_cache itself:
1227 * kmem_cache is statically allocated.
1228 * Initially an __init data area is used for the head array and the
1229 * kmem_cache_node structures, it's replaced with a kmalloc allocated
1230 * array at the end of the bootstrap.
1231 * 2) Create the first kmalloc cache.
1232 * The struct kmem_cache for the new cache is allocated normally.
1233 * An __init data area is used for the head array.
1234 * 3) Create the remaining kmalloc caches, with minimally sized
1235 * head arrays.
1236 * 4) Replace the __init data head arrays for kmem_cache and the first
1237 * kmalloc cache with kmalloc allocated arrays.
1238 * 5) Replace the __init data for kmem_cache_node for kmem_cache and
1239 * the other cache's with kmalloc allocated memory.
1240 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1241 */
1242
1243 /* 1) create the kmem_cache */
1244
1245 /*
1246 * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
1247 */
1248 create_boot_cache(kmem_cache, "kmem_cache",
1249 offsetof(struct kmem_cache, node) +
1250 nr_node_ids * sizeof(struct kmem_cache_node *),
1251 SLAB_HWCACHE_ALIGN, 0, 0);
1252 list_add(&kmem_cache->list, &slab_caches);
1253 slab_state = PARTIAL;
1254
1255 /*
1256 * Initialize the caches that provide memory for the kmem_cache_node
1257 * structures first. Without this, further allocations will bug.
1258 */
1259 kmalloc_caches[KMALLOC_NORMAL][INDEX_NODE] = create_kmalloc_cache(
1260 kmalloc_info[INDEX_NODE].name[KMALLOC_NORMAL],
1261 kmalloc_info[INDEX_NODE].size,
1262 ARCH_KMALLOC_FLAGS, 0,
1263 kmalloc_info[INDEX_NODE].size);
1264 slab_state = PARTIAL_NODE;
1265 setup_kmalloc_cache_index_table();
1266
1267 slab_early_init = 0;
1268
1269 /* 5) Replace the bootstrap kmem_cache_node */
1270 {
1271 int nid;
1272
1273 for_each_online_node(nid) {
1274 init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid);
1275
1276 init_list(kmalloc_caches[KMALLOC_NORMAL][INDEX_NODE],
1277 &init_kmem_cache_node[SIZE_NODE + nid], nid);
1278 }
1279 }
1280
1281 create_kmalloc_caches(ARCH_KMALLOC_FLAGS);
1282}
1283
1284void __init kmem_cache_init_late(void)
1285{
1286 struct kmem_cache *cachep;
1287
1288 /* 6) resize the head arrays to their final sizes */
1289 mutex_lock(&slab_mutex);
1290 list_for_each_entry(cachep, &slab_caches, list)
1291 if (enable_cpucache(cachep, GFP_NOWAIT))
1292 BUG();
1293 mutex_unlock(&slab_mutex);
1294
1295 /* Done! */
1296 slab_state = FULL;
1297
1298#ifdef CONFIG_NUMA
1299 /*
1300 * Register a memory hotplug callback that initializes and frees
1301 * node.
1302 */
1303 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
1304#endif
1305
1306 /*
1307 * The reap timers are started later, with a module init call: That part
1308 * of the kernel is not yet operational.
1309 */
1310}
1311
1312static int __init cpucache_init(void)
1313{
1314 int ret;
1315
1316 /*
1317 * Register the timers that return unneeded pages to the page allocator
1318 */
1319 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SLAB online",
1320 slab_online_cpu, slab_offline_cpu);
1321 WARN_ON(ret < 0);
1322
1323 return 0;
1324}
1325__initcall(cpucache_init);
1326
1327static noinline void
1328slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
1329{
1330#if DEBUG
1331 struct kmem_cache_node *n;
1332 unsigned long flags;
1333 int node;
1334 static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
1335 DEFAULT_RATELIMIT_BURST);
1336
1337 if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs))
1338 return;
1339
1340 pr_warn("SLAB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n",
1341 nodeid, gfpflags, &gfpflags);
1342 pr_warn(" cache: %s, object size: %d, order: %d\n",
1343 cachep->name, cachep->size, cachep->gfporder);
1344
1345 for_each_kmem_cache_node(cachep, node, n) {
1346 unsigned long total_slabs, free_slabs, free_objs;
1347
1348 spin_lock_irqsave(&n->list_lock, flags);
1349 total_slabs = n->total_slabs;
1350 free_slabs = n->free_slabs;
1351 free_objs = n->free_objects;
1352 spin_unlock_irqrestore(&n->list_lock, flags);
1353
1354 pr_warn(" node %d: slabs: %ld/%ld, objs: %ld/%ld\n",
1355 node, total_slabs - free_slabs, total_slabs,
1356 (total_slabs * cachep->num) - free_objs,
1357 total_slabs * cachep->num);
1358 }
1359#endif
1360}
1361
1362/*
1363 * Interface to system's page allocator. No need to hold the
1364 * kmem_cache_node ->list_lock.
1365 *
1366 * If we requested dmaable memory, we will get it. Even if we
1367 * did not request dmaable memory, we might get it, but that
1368 * would be relatively rare and ignorable.
1369 */
1370static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
1371 int nodeid)
1372{
1373 struct page *page;
1374
1375 flags |= cachep->allocflags;
1376
1377 page = __alloc_pages_node(nodeid, flags, cachep->gfporder);
1378 if (!page) {
1379 slab_out_of_memory(cachep, flags, nodeid);
1380 return NULL;
1381 }
1382
1383 account_slab_page(page, cachep->gfporder, cachep, flags);
1384 __SetPageSlab(page);
1385 /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
1386 if (sk_memalloc_socks() && page_is_pfmemalloc(page))
1387 SetPageSlabPfmemalloc(page);
1388
1389 return page;
1390}
1391
1392/*
1393 * Interface to system's page release.
1394 */
1395static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
1396{
1397 int order = cachep->gfporder;
1398
1399 BUG_ON(!PageSlab(page));
1400 __ClearPageSlabPfmemalloc(page);
1401 __ClearPageSlab(page);
1402 page_mapcount_reset(page);
1403 /* In union with page->mapping where page allocator expects NULL */
1404 page->slab_cache = NULL;
1405
1406 if (current->reclaim_state)
1407 current->reclaim_state->reclaimed_slab += 1 << order;
1408 unaccount_slab_page(page, order, cachep);
1409 __free_pages(page, order);
1410}
1411
1412static void kmem_rcu_free(struct rcu_head *head)
1413{
1414 struct kmem_cache *cachep;
1415 struct page *page;
1416
1417 page = container_of(head, struct page, rcu_head);
1418 cachep = page->slab_cache;
1419
1420 kmem_freepages(cachep, page);
1421}
1422
1423#if DEBUG
1424static bool is_debug_pagealloc_cache(struct kmem_cache *cachep)
1425{
1426 if (debug_pagealloc_enabled_static() && OFF_SLAB(cachep) &&
1427 (cachep->size % PAGE_SIZE) == 0)
1428 return true;
1429
1430 return false;
1431}
1432
1433#ifdef CONFIG_DEBUG_PAGEALLOC
1434static void slab_kernel_map(struct kmem_cache *cachep, void *objp, int map)
1435{
1436 if (!is_debug_pagealloc_cache(cachep))
1437 return;
1438
1439 __kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map);
1440}
1441
1442#else
1443static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp,
1444 int map) {}
1445
1446#endif
1447
1448static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
1449{
1450 int size = cachep->object_size;
1451 addr = &((char *)addr)[obj_offset(cachep)];
1452
1453 memset(addr, val, size);
1454 *(unsigned char *)(addr + size - 1) = POISON_END;
1455}
1456
1457static void dump_line(char *data, int offset, int limit)
1458{
1459 int i;
1460 unsigned char error = 0;
1461 int bad_count = 0;
1462
1463 pr_err("%03x: ", offset);
1464 for (i = 0; i < limit; i++) {
1465 if (data[offset + i] != POISON_FREE) {
1466 error = data[offset + i];
1467 bad_count++;
1468 }
1469 }
1470 print_hex_dump(KERN_CONT, "", 0, 16, 1,
1471 &data[offset], limit, 1);
1472
1473 if (bad_count == 1) {
1474 error ^= POISON_FREE;
1475 if (!(error & (error - 1))) {
1476 pr_err("Single bit error detected. Probably bad RAM.\n");
1477#ifdef CONFIG_X86
1478 pr_err("Run memtest86+ or a similar memory test tool.\n");
1479#else
1480 pr_err("Run a memory test tool.\n");
1481#endif
1482 }
1483 }
1484}
1485#endif
1486
1487#if DEBUG
1488
1489static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
1490{
1491 int i, size;
1492 char *realobj;
1493
1494 if (cachep->flags & SLAB_RED_ZONE) {
1495 pr_err("Redzone: 0x%llx/0x%llx\n",
1496 *dbg_redzone1(cachep, objp),
1497 *dbg_redzone2(cachep, objp));
1498 }
1499
1500 if (cachep->flags & SLAB_STORE_USER)
1501 pr_err("Last user: (%pSR)\n", *dbg_userword(cachep, objp));
1502 realobj = (char *)objp + obj_offset(cachep);
1503 size = cachep->object_size;
1504 for (i = 0; i < size && lines; i += 16, lines--) {
1505 int limit;
1506 limit = 16;
1507 if (i + limit > size)
1508 limit = size - i;
1509 dump_line(realobj, i, limit);
1510 }
1511}
1512
1513static void check_poison_obj(struct kmem_cache *cachep, void *objp)
1514{
1515 char *realobj;
1516 int size, i;
1517 int lines = 0;
1518
1519 if (is_debug_pagealloc_cache(cachep))
1520 return;
1521
1522 realobj = (char *)objp + obj_offset(cachep);
1523 size = cachep->object_size;
1524
1525 for (i = 0; i < size; i++) {
1526 char exp = POISON_FREE;
1527 if (i == size - 1)
1528 exp = POISON_END;
1529 if (realobj[i] != exp) {
1530 int limit;
1531 /* Mismatch ! */
1532 /* Print header */
1533 if (lines == 0) {
1534 pr_err("Slab corruption (%s): %s start=%px, len=%d\n",
1535 print_tainted(), cachep->name,
1536 realobj, size);
1537 print_objinfo(cachep, objp, 0);
1538 }
1539 /* Hexdump the affected line */
1540 i = (i / 16) * 16;
1541 limit = 16;
1542 if (i + limit > size)
1543 limit = size - i;
1544 dump_line(realobj, i, limit);
1545 i += 16;
1546 lines++;
1547 /* Limit to 5 lines */
1548 if (lines > 5)
1549 break;
1550 }
1551 }
1552 if (lines != 0) {
1553 /* Print some data about the neighboring objects, if they
1554 * exist:
1555 */
1556 struct page *page = virt_to_head_page(objp);
1557 unsigned int objnr;
1558
1559 objnr = obj_to_index(cachep, page, objp);
1560 if (objnr) {
1561 objp = index_to_obj(cachep, page, objnr - 1);
1562 realobj = (char *)objp + obj_offset(cachep);
1563 pr_err("Prev obj: start=%px, len=%d\n", realobj, size);
1564 print_objinfo(cachep, objp, 2);
1565 }
1566 if (objnr + 1 < cachep->num) {
1567 objp = index_to_obj(cachep, page, objnr + 1);
1568 realobj = (char *)objp + obj_offset(cachep);
1569 pr_err("Next obj: start=%px, len=%d\n", realobj, size);
1570 print_objinfo(cachep, objp, 2);
1571 }
1572 }
1573}
1574#endif
1575
1576#if DEBUG
1577static void slab_destroy_debugcheck(struct kmem_cache *cachep,
1578 struct page *page)
1579{
1580 int i;
1581
1582 if (OBJFREELIST_SLAB(cachep) && cachep->flags & SLAB_POISON) {
1583 poison_obj(cachep, page->freelist - obj_offset(cachep),
1584 POISON_FREE);
1585 }
1586
1587 for (i = 0; i < cachep->num; i++) {
1588 void *objp = index_to_obj(cachep, page, i);
1589
1590 if (cachep->flags & SLAB_POISON) {
1591 check_poison_obj(cachep, objp);
1592 slab_kernel_map(cachep, objp, 1);
1593 }
1594 if (cachep->flags & SLAB_RED_ZONE) {
1595 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
1596 slab_error(cachep, "start of a freed object was overwritten");
1597 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
1598 slab_error(cachep, "end of a freed object was overwritten");
1599 }
1600 }
1601}
1602#else
1603static void slab_destroy_debugcheck(struct kmem_cache *cachep,
1604 struct page *page)
1605{
1606}
1607#endif
1608
1609/**
1610 * slab_destroy - destroy and release all objects in a slab
1611 * @cachep: cache pointer being destroyed
1612 * @page: page pointer being destroyed
1613 *
1614 * Destroy all the objs in a slab page, and release the mem back to the system.
1615 * Before calling the slab page must have been unlinked from the cache. The
1616 * kmem_cache_node ->list_lock is not held/needed.
1617 */
1618static void slab_destroy(struct kmem_cache *cachep, struct page *page)
1619{
1620 void *freelist;
1621
1622 freelist = page->freelist;
1623 slab_destroy_debugcheck(cachep, page);
1624 if (unlikely(cachep->flags & SLAB_TYPESAFE_BY_RCU))
1625 call_rcu(&page->rcu_head, kmem_rcu_free);
1626 else
1627 kmem_freepages(cachep, page);
1628
1629 /*
1630 * From now on, we don't use freelist
1631 * although actual page can be freed in rcu context
1632 */
1633 if (OFF_SLAB(cachep))
1634 kmem_cache_free(cachep->freelist_cache, freelist);
1635}
1636
1637/*
1638 * Update the size of the caches before calling slabs_destroy as it may
1639 * recursively call kfree.
1640 */
1641static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list)
1642{
1643 struct page *page, *n;
1644
1645 list_for_each_entry_safe(page, n, list, slab_list) {
1646 list_del(&page->slab_list);
1647 slab_destroy(cachep, page);
1648 }
1649}
1650
1651/**
1652 * calculate_slab_order - calculate size (page order) of slabs
1653 * @cachep: pointer to the cache that is being created
1654 * @size: size of objects to be created in this cache.
1655 * @flags: slab allocation flags
1656 *
1657 * Also calculates the number of objects per slab.
1658 *
1659 * This could be made much more intelligent. For now, try to avoid using
1660 * high order pages for slabs. When the gfp() functions are more friendly
1661 * towards high-order requests, this should be changed.
1662 *
1663 * Return: number of left-over bytes in a slab
1664 */
1665static size_t calculate_slab_order(struct kmem_cache *cachep,
1666 size_t size, slab_flags_t flags)
1667{
1668 size_t left_over = 0;
1669 int gfporder;
1670
1671 for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
1672 unsigned int num;
1673 size_t remainder;
1674
1675 num = cache_estimate(gfporder, size, flags, &remainder);
1676 if (!num)
1677 continue;
1678
1679 /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
1680 if (num > SLAB_OBJ_MAX_NUM)
1681 break;
1682
1683 if (flags & CFLGS_OFF_SLAB) {
1684 struct kmem_cache *freelist_cache;
1685 size_t freelist_size;
1686
1687 freelist_size = num * sizeof(freelist_idx_t);
1688 freelist_cache = kmalloc_slab(freelist_size, 0u);
1689 if (!freelist_cache)
1690 continue;
1691
1692 /*
1693 * Needed to avoid possible looping condition
1694 * in cache_grow_begin()
1695 */
1696 if (OFF_SLAB(freelist_cache))
1697 continue;
1698
1699 /* check if off slab has enough benefit */
1700 if (freelist_cache->size > cachep->size / 2)
1701 continue;
1702 }
1703
1704 /* Found something acceptable - save it away */
1705 cachep->num = num;
1706 cachep->gfporder = gfporder;
1707 left_over = remainder;
1708
1709 /*
1710 * A VFS-reclaimable slab tends to have most allocations
1711 * as GFP_NOFS and we really don't want to have to be allocating
1712 * higher-order pages when we are unable to shrink dcache.
1713 */
1714 if (flags & SLAB_RECLAIM_ACCOUNT)
1715 break;
1716
1717 /*
1718 * Large number of objects is good, but very large slabs are
1719 * currently bad for the gfp()s.
1720 */
1721 if (gfporder >= slab_max_order)
1722 break;
1723
1724 /*
1725 * Acceptable internal fragmentation?
1726 */
1727 if (left_over * 8 <= (PAGE_SIZE << gfporder))
1728 break;
1729 }
1730 return left_over;
1731}
1732
1733static struct array_cache __percpu *alloc_kmem_cache_cpus(
1734 struct kmem_cache *cachep, int entries, int batchcount)
1735{
1736 int cpu;
1737 size_t size;
1738 struct array_cache __percpu *cpu_cache;
1739
1740 size = sizeof(void *) * entries + sizeof(struct array_cache);
1741 cpu_cache = __alloc_percpu(size, sizeof(void *));
1742
1743 if (!cpu_cache)
1744 return NULL;
1745
1746 for_each_possible_cpu(cpu) {
1747 init_arraycache(per_cpu_ptr(cpu_cache, cpu),
1748 entries, batchcount);
1749 }
1750
1751 return cpu_cache;
1752}
1753
1754static int __ref setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
1755{
1756 if (slab_state >= FULL)
1757 return enable_cpucache(cachep, gfp);
1758
1759 cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1);
1760 if (!cachep->cpu_cache)
1761 return 1;
1762
1763 if (slab_state == DOWN) {
1764 /* Creation of first cache (kmem_cache). */
1765 set_up_node(kmem_cache, CACHE_CACHE);
1766 } else if (slab_state == PARTIAL) {
1767 /* For kmem_cache_node */
1768 set_up_node(cachep, SIZE_NODE);
1769 } else {
1770 int node;
1771
1772 for_each_online_node(node) {
1773 cachep->node[node] = kmalloc_node(
1774 sizeof(struct kmem_cache_node), gfp, node);
1775 BUG_ON(!cachep->node[node]);
1776 kmem_cache_node_init(cachep->node[node]);
1777 }
1778 }
1779
1780 cachep->node[numa_mem_id()]->next_reap =
1781 jiffies + REAPTIMEOUT_NODE +
1782 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
1783
1784 cpu_cache_get(cachep)->avail = 0;
1785 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
1786 cpu_cache_get(cachep)->batchcount = 1;
1787 cpu_cache_get(cachep)->touched = 0;
1788 cachep->batchcount = 1;
1789 cachep->limit = BOOT_CPUCACHE_ENTRIES;
1790 return 0;
1791}
1792
1793slab_flags_t kmem_cache_flags(unsigned int object_size,
1794 slab_flags_t flags, const char *name)
1795{
1796 return flags;
1797}
1798
1799struct kmem_cache *
1800__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
1801 slab_flags_t flags, void (*ctor)(void *))
1802{
1803 struct kmem_cache *cachep;
1804
1805 cachep = find_mergeable(size, align, flags, name, ctor);
1806 if (cachep) {
1807 cachep->refcount++;
1808
1809 /*
1810 * Adjust the object sizes so that we clear
1811 * the complete object on kzalloc.
1812 */
1813 cachep->object_size = max_t(int, cachep->object_size, size);
1814 }
1815 return cachep;
1816}
1817
1818static bool set_objfreelist_slab_cache(struct kmem_cache *cachep,
1819 size_t size, slab_flags_t flags)
1820{
1821 size_t left;
1822
1823 cachep->num = 0;
1824
1825 /*
1826 * If slab auto-initialization on free is enabled, store the freelist
1827 * off-slab, so that its contents don't end up in one of the allocated
1828 * objects.
1829 */
1830 if (unlikely(slab_want_init_on_free(cachep)))
1831 return false;
1832
1833 if (cachep->ctor || flags & SLAB_TYPESAFE_BY_RCU)
1834 return false;
1835
1836 left = calculate_slab_order(cachep, size,
1837 flags | CFLGS_OBJFREELIST_SLAB);
1838 if (!cachep->num)
1839 return false;
1840
1841 if (cachep->num * sizeof(freelist_idx_t) > cachep->object_size)
1842 return false;
1843
1844 cachep->colour = left / cachep->colour_off;
1845
1846 return true;
1847}
1848
1849static bool set_off_slab_cache(struct kmem_cache *cachep,
1850 size_t size, slab_flags_t flags)
1851{
1852 size_t left;
1853
1854 cachep->num = 0;
1855
1856 /*
1857 * Always use on-slab management when SLAB_NOLEAKTRACE
1858 * to avoid recursive calls into kmemleak.
1859 */
1860 if (flags & SLAB_NOLEAKTRACE)
1861 return false;
1862
1863 /*
1864 * Size is large, assume best to place the slab management obj
1865 * off-slab (should allow better packing of objs).
1866 */
1867 left = calculate_slab_order(cachep, size, flags | CFLGS_OFF_SLAB);
1868 if (!cachep->num)
1869 return false;
1870
1871 /*
1872 * If the slab has been placed off-slab, and we have enough space then
1873 * move it on-slab. This is at the expense of any extra colouring.
1874 */
1875 if (left >= cachep->num * sizeof(freelist_idx_t))
1876 return false;
1877
1878 cachep->colour = left / cachep->colour_off;
1879
1880 return true;
1881}
1882
1883static bool set_on_slab_cache(struct kmem_cache *cachep,
1884 size_t size, slab_flags_t flags)
1885{
1886 size_t left;
1887
1888 cachep->num = 0;
1889
1890 left = calculate_slab_order(cachep, size, flags);
1891 if (!cachep->num)
1892 return false;
1893
1894 cachep->colour = left / cachep->colour_off;
1895
1896 return true;
1897}
1898
1899/**
1900 * __kmem_cache_create - Create a cache.
1901 * @cachep: cache management descriptor
1902 * @flags: SLAB flags
1903 *
1904 * Returns a ptr to the cache on success, NULL on failure.
1905 * Cannot be called within a int, but can be interrupted.
1906 * The @ctor is run when new pages are allocated by the cache.
1907 *
1908 * The flags are
1909 *
1910 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
1911 * to catch references to uninitialised memory.
1912 *
1913 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
1914 * for buffer overruns.
1915 *
1916 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
1917 * cacheline. This can be beneficial if you're counting cycles as closely
1918 * as davem.
1919 *
1920 * Return: a pointer to the created cache or %NULL in case of error
1921 */
1922int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags)
1923{
1924 size_t ralign = BYTES_PER_WORD;
1925 gfp_t gfp;
1926 int err;
1927 unsigned int size = cachep->size;
1928
1929#if DEBUG
1930#if FORCED_DEBUG
1931 /*
1932 * Enable redzoning and last user accounting, except for caches with
1933 * large objects, if the increased size would increase the object size
1934 * above the next power of two: caches with object sizes just above a
1935 * power of two have a significant amount of internal fragmentation.
1936 */
1937 if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
1938 2 * sizeof(unsigned long long)))
1939 flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
1940 if (!(flags & SLAB_TYPESAFE_BY_RCU))
1941 flags |= SLAB_POISON;
1942#endif
1943#endif
1944
1945 /*
1946 * Check that size is in terms of words. This is needed to avoid
1947 * unaligned accesses for some archs when redzoning is used, and makes
1948 * sure any on-slab bufctl's are also correctly aligned.
1949 */
1950 size = ALIGN(size, BYTES_PER_WORD);
1951
1952 if (flags & SLAB_RED_ZONE) {
1953 ralign = REDZONE_ALIGN;
1954 /* If redzoning, ensure that the second redzone is suitably
1955 * aligned, by adjusting the object size accordingly. */
1956 size = ALIGN(size, REDZONE_ALIGN);
1957 }
1958
1959 /* 3) caller mandated alignment */
1960 if (ralign < cachep->align) {
1961 ralign = cachep->align;
1962 }
1963 /* disable debug if necessary */
1964 if (ralign > __alignof__(unsigned long long))
1965 flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
1966 /*
1967 * 4) Store it.
1968 */
1969 cachep->align = ralign;
1970 cachep->colour_off = cache_line_size();
1971 /* Offset must be a multiple of the alignment. */
1972 if (cachep->colour_off < cachep->align)
1973 cachep->colour_off = cachep->align;
1974
1975 if (slab_is_available())
1976 gfp = GFP_KERNEL;
1977 else
1978 gfp = GFP_NOWAIT;
1979
1980#if DEBUG
1981
1982 /*
1983 * Both debugging options require word-alignment which is calculated
1984 * into align above.
1985 */
1986 if (flags & SLAB_RED_ZONE) {
1987 /* add space for red zone words */
1988 cachep->obj_offset += sizeof(unsigned long long);
1989 size += 2 * sizeof(unsigned long long);
1990 }
1991 if (flags & SLAB_STORE_USER) {
1992 /* user store requires one word storage behind the end of
1993 * the real object. But if the second red zone needs to be
1994 * aligned to 64 bits, we must allow that much space.
1995 */
1996 if (flags & SLAB_RED_ZONE)
1997 size += REDZONE_ALIGN;
1998 else
1999 size += BYTES_PER_WORD;
2000 }
2001#endif
2002
2003 kasan_cache_create(cachep, &size, &flags);
2004
2005 size = ALIGN(size, cachep->align);
2006 /*
2007 * We should restrict the number of objects in a slab to implement
2008 * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
2009 */
2010 if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
2011 size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
2012
2013#if DEBUG
2014 /*
2015 * To activate debug pagealloc, off-slab management is necessary
2016 * requirement. In early phase of initialization, small sized slab
2017 * doesn't get initialized so it would not be possible. So, we need
2018 * to check size >= 256. It guarantees that all necessary small
2019 * sized slab is initialized in current slab initialization sequence.
2020 */
2021 if (debug_pagealloc_enabled_static() && (flags & SLAB_POISON) &&
2022 size >= 256 && cachep->object_size > cache_line_size()) {
2023 if (size < PAGE_SIZE || size % PAGE_SIZE == 0) {
2024 size_t tmp_size = ALIGN(size, PAGE_SIZE);
2025
2026 if (set_off_slab_cache(cachep, tmp_size, flags)) {
2027 flags |= CFLGS_OFF_SLAB;
2028 cachep->obj_offset += tmp_size - size;
2029 size = tmp_size;
2030 goto done;
2031 }
2032 }
2033 }
2034#endif
2035
2036 if (set_objfreelist_slab_cache(cachep, size, flags)) {
2037 flags |= CFLGS_OBJFREELIST_SLAB;
2038 goto done;
2039 }
2040
2041 if (set_off_slab_cache(cachep, size, flags)) {
2042 flags |= CFLGS_OFF_SLAB;
2043 goto done;
2044 }
2045
2046 if (set_on_slab_cache(cachep, size, flags))
2047 goto done;
2048
2049 return -E2BIG;
2050
2051done:
2052 cachep->freelist_size = cachep->num * sizeof(freelist_idx_t);
2053 cachep->flags = flags;
2054 cachep->allocflags = __GFP_COMP;
2055 if (flags & SLAB_CACHE_DMA)
2056 cachep->allocflags |= GFP_DMA;
2057 if (flags & SLAB_CACHE_DMA32)
2058 cachep->allocflags |= GFP_DMA32;
2059 if (flags & SLAB_RECLAIM_ACCOUNT)
2060 cachep->allocflags |= __GFP_RECLAIMABLE;
2061 cachep->size = size;
2062 cachep->reciprocal_buffer_size = reciprocal_value(size);
2063
2064#if DEBUG
2065 /*
2066 * If we're going to use the generic kernel_map_pages()
2067 * poisoning, then it's going to smash the contents of
2068 * the redzone and userword anyhow, so switch them off.
2069 */
2070 if (IS_ENABLED(CONFIG_PAGE_POISONING) &&
2071 (cachep->flags & SLAB_POISON) &&
2072 is_debug_pagealloc_cache(cachep))
2073 cachep->flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
2074#endif
2075
2076 if (OFF_SLAB(cachep)) {
2077 cachep->freelist_cache =
2078 kmalloc_slab(cachep->freelist_size, 0u);
2079 }
2080
2081 err = setup_cpu_cache(cachep, gfp);
2082 if (err) {
2083 __kmem_cache_release(cachep);
2084 return err;
2085 }
2086
2087 return 0;
2088}
2089
2090#if DEBUG
2091static void check_irq_off(void)
2092{
2093 BUG_ON(!irqs_disabled());
2094}
2095
2096static void check_irq_on(void)
2097{
2098 BUG_ON(irqs_disabled());
2099}
2100
2101static void check_mutex_acquired(void)
2102{
2103 BUG_ON(!mutex_is_locked(&slab_mutex));
2104}
2105
2106static void check_spinlock_acquired(struct kmem_cache *cachep)
2107{
2108#ifdef CONFIG_SMP
2109 check_irq_off();
2110 assert_spin_locked(&get_node(cachep, numa_mem_id())->list_lock);
2111#endif
2112}
2113
2114static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2115{
2116#ifdef CONFIG_SMP
2117 check_irq_off();
2118 assert_spin_locked(&get_node(cachep, node)->list_lock);
2119#endif
2120}
2121
2122#else
2123#define check_irq_off() do { } while(0)
2124#define check_irq_on() do { } while(0)
2125#define check_mutex_acquired() do { } while(0)
2126#define check_spinlock_acquired(x) do { } while(0)
2127#define check_spinlock_acquired_node(x, y) do { } while(0)
2128#endif
2129
2130static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac,
2131 int node, bool free_all, struct list_head *list)
2132{
2133 int tofree;
2134
2135 if (!ac || !ac->avail)
2136 return;
2137
2138 tofree = free_all ? ac->avail : (ac->limit + 4) / 5;
2139 if (tofree > ac->avail)
2140 tofree = (ac->avail + 1) / 2;
2141
2142 free_block(cachep, ac->entry, tofree, node, list);
2143 ac->avail -= tofree;
2144 memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail);
2145}
2146
2147static void do_drain(void *arg)
2148{
2149 struct kmem_cache *cachep = arg;
2150 struct array_cache *ac;
2151 int node = numa_mem_id();
2152 struct kmem_cache_node *n;
2153 LIST_HEAD(list);
2154
2155 check_irq_off();
2156 ac = cpu_cache_get(cachep);
2157 n = get_node(cachep, node);
2158 spin_lock(&n->list_lock);
2159 free_block(cachep, ac->entry, ac->avail, node, &list);
2160 spin_unlock(&n->list_lock);
2161 ac->avail = 0;
2162 slabs_destroy(cachep, &list);
2163}
2164
2165static void drain_cpu_caches(struct kmem_cache *cachep)
2166{
2167 struct kmem_cache_node *n;
2168 int node;
2169 LIST_HEAD(list);
2170
2171 on_each_cpu(do_drain, cachep, 1);
2172 check_irq_on();
2173 for_each_kmem_cache_node(cachep, node, n)
2174 if (n->alien)
2175 drain_alien_cache(cachep, n->alien);
2176
2177 for_each_kmem_cache_node(cachep, node, n) {
2178 spin_lock_irq(&n->list_lock);
2179 drain_array_locked(cachep, n->shared, node, true, &list);
2180 spin_unlock_irq(&n->list_lock);
2181
2182 slabs_destroy(cachep, &list);
2183 }
2184}
2185
2186/*
2187 * Remove slabs from the list of free slabs.
2188 * Specify the number of slabs to drain in tofree.
2189 *
2190 * Returns the actual number of slabs released.
2191 */
2192static int drain_freelist(struct kmem_cache *cache,
2193 struct kmem_cache_node *n, int tofree)
2194{
2195 struct list_head *p;
2196 int nr_freed;
2197 struct page *page;
2198
2199 nr_freed = 0;
2200 while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
2201
2202 spin_lock_irq(&n->list_lock);
2203 p = n->slabs_free.prev;
2204 if (p == &n->slabs_free) {
2205 spin_unlock_irq(&n->list_lock);
2206 goto out;
2207 }
2208
2209 page = list_entry(p, struct page, slab_list);
2210 list_del(&page->slab_list);
2211 n->free_slabs--;
2212 n->total_slabs--;
2213 /*
2214 * Safe to drop the lock. The slab is no longer linked
2215 * to the cache.
2216 */
2217 n->free_objects -= cache->num;
2218 spin_unlock_irq(&n->list_lock);
2219 slab_destroy(cache, page);
2220 nr_freed++;
2221 }
2222out:
2223 return nr_freed;
2224}
2225
2226bool __kmem_cache_empty(struct kmem_cache *s)
2227{
2228 int node;
2229 struct kmem_cache_node *n;
2230
2231 for_each_kmem_cache_node(s, node, n)
2232 if (!list_empty(&n->slabs_full) ||
2233 !list_empty(&n->slabs_partial))
2234 return false;
2235 return true;
2236}
2237
2238int __kmem_cache_shrink(struct kmem_cache *cachep)
2239{
2240 int ret = 0;
2241 int node;
2242 struct kmem_cache_node *n;
2243
2244 drain_cpu_caches(cachep);
2245
2246 check_irq_on();
2247 for_each_kmem_cache_node(cachep, node, n) {
2248 drain_freelist(cachep, n, INT_MAX);
2249
2250 ret += !list_empty(&n->slabs_full) ||
2251 !list_empty(&n->slabs_partial);
2252 }
2253 return (ret ? 1 : 0);
2254}
2255
2256int __kmem_cache_shutdown(struct kmem_cache *cachep)
2257{
2258 return __kmem_cache_shrink(cachep);
2259}
2260
2261void __kmem_cache_release(struct kmem_cache *cachep)
2262{
2263 int i;
2264 struct kmem_cache_node *n;
2265
2266 cache_random_seq_destroy(cachep);
2267
2268 free_percpu(cachep->cpu_cache);
2269
2270 /* NUMA: free the node structures */
2271 for_each_kmem_cache_node(cachep, i, n) {
2272 kfree(n->shared);
2273 free_alien_cache(n->alien);
2274 kfree(n);
2275 cachep->node[i] = NULL;
2276 }
2277}
2278
2279/*
2280 * Get the memory for a slab management obj.
2281 *
2282 * For a slab cache when the slab descriptor is off-slab, the
2283 * slab descriptor can't come from the same cache which is being created,
2284 * Because if it is the case, that means we defer the creation of
2285 * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
2286 * And we eventually call down to __kmem_cache_create(), which
2287 * in turn looks up in the kmalloc_{dma,}_caches for the desired-size one.
2288 * This is a "chicken-and-egg" problem.
2289 *
2290 * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
2291 * which are all initialized during kmem_cache_init().
2292 */
2293static void *alloc_slabmgmt(struct kmem_cache *cachep,
2294 struct page *page, int colour_off,
2295 gfp_t local_flags, int nodeid)
2296{
2297 void *freelist;
2298 void *addr = page_address(page);
2299
2300 page->s_mem = addr + colour_off;
2301 page->active = 0;
2302
2303 if (OBJFREELIST_SLAB(cachep))
2304 freelist = NULL;
2305 else if (OFF_SLAB(cachep)) {
2306 /* Slab management obj is off-slab. */
2307 freelist = kmem_cache_alloc_node(cachep->freelist_cache,
2308 local_flags, nodeid);
2309 } else {
2310 /* We will use last bytes at the slab for freelist */
2311 freelist = addr + (PAGE_SIZE << cachep->gfporder) -
2312 cachep->freelist_size;
2313 }
2314
2315 return freelist;
2316}
2317
2318static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx)
2319{
2320 return ((freelist_idx_t *)page->freelist)[idx];
2321}
2322
2323static inline void set_free_obj(struct page *page,
2324 unsigned int idx, freelist_idx_t val)
2325{
2326 ((freelist_idx_t *)(page->freelist))[idx] = val;
2327}
2328
2329static void cache_init_objs_debug(struct kmem_cache *cachep, struct page *page)
2330{
2331#if DEBUG
2332 int i;
2333
2334 for (i = 0; i < cachep->num; i++) {
2335 void *objp = index_to_obj(cachep, page, i);
2336
2337 if (cachep->flags & SLAB_STORE_USER)
2338 *dbg_userword(cachep, objp) = NULL;
2339
2340 if (cachep->flags & SLAB_RED_ZONE) {
2341 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2342 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2343 }
2344 /*
2345 * Constructors are not allowed to allocate memory from the same
2346 * cache which they are a constructor for. Otherwise, deadlock.
2347 * They must also be threaded.
2348 */
2349 if (cachep->ctor && !(cachep->flags & SLAB_POISON)) {
2350 kasan_unpoison_object_data(cachep,
2351 objp + obj_offset(cachep));
2352 cachep->ctor(objp + obj_offset(cachep));
2353 kasan_poison_object_data(
2354 cachep, objp + obj_offset(cachep));
2355 }
2356
2357 if (cachep->flags & SLAB_RED_ZONE) {
2358 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
2359 slab_error(cachep, "constructor overwrote the end of an object");
2360 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
2361 slab_error(cachep, "constructor overwrote the start of an object");
2362 }
2363 /* need to poison the objs? */
2364 if (cachep->flags & SLAB_POISON) {
2365 poison_obj(cachep, objp, POISON_FREE);
2366 slab_kernel_map(cachep, objp, 0);
2367 }
2368 }
2369#endif
2370}
2371
2372#ifdef CONFIG_SLAB_FREELIST_RANDOM
2373/* Hold information during a freelist initialization */
2374union freelist_init_state {
2375 struct {
2376 unsigned int pos;
2377 unsigned int *list;
2378 unsigned int count;
2379 };
2380 struct rnd_state rnd_state;
2381};
2382
2383/*
2384 * Initialize the state based on the randomization method available.
2385 * return true if the pre-computed list is available, false otherwise.
2386 */
2387static bool freelist_state_initialize(union freelist_init_state *state,
2388 struct kmem_cache *cachep,
2389 unsigned int count)
2390{
2391 bool ret;
2392 unsigned int rand;
2393
2394 /* Use best entropy available to define a random shift */
2395 rand = get_random_int();
2396
2397 /* Use a random state if the pre-computed list is not available */
2398 if (!cachep->random_seq) {
2399 prandom_seed_state(&state->rnd_state, rand);
2400 ret = false;
2401 } else {
2402 state->list = cachep->random_seq;
2403 state->count = count;
2404 state->pos = rand % count;
2405 ret = true;
2406 }
2407 return ret;
2408}
2409
2410/* Get the next entry on the list and randomize it using a random shift */
2411static freelist_idx_t next_random_slot(union freelist_init_state *state)
2412{
2413 if (state->pos >= state->count)
2414 state->pos = 0;
2415 return state->list[state->pos++];
2416}
2417
2418/* Swap two freelist entries */
2419static void swap_free_obj(struct page *page, unsigned int a, unsigned int b)
2420{
2421 swap(((freelist_idx_t *)page->freelist)[a],
2422 ((freelist_idx_t *)page->freelist)[b]);
2423}
2424
2425/*
2426 * Shuffle the freelist initialization state based on pre-computed lists.
2427 * return true if the list was successfully shuffled, false otherwise.
2428 */
2429static bool shuffle_freelist(struct kmem_cache *cachep, struct page *page)
2430{
2431 unsigned int objfreelist = 0, i, rand, count = cachep->num;
2432 union freelist_init_state state;
2433 bool precomputed;
2434
2435 if (count < 2)
2436 return false;
2437
2438 precomputed = freelist_state_initialize(&state, cachep, count);
2439
2440 /* Take a random entry as the objfreelist */
2441 if (OBJFREELIST_SLAB(cachep)) {
2442 if (!precomputed)
2443 objfreelist = count - 1;
2444 else
2445 objfreelist = next_random_slot(&state);
2446 page->freelist = index_to_obj(cachep, page, objfreelist) +
2447 obj_offset(cachep);
2448 count--;
2449 }
2450
2451 /*
2452 * On early boot, generate the list dynamically.
2453 * Later use a pre-computed list for speed.
2454 */
2455 if (!precomputed) {
2456 for (i = 0; i < count; i++)
2457 set_free_obj(page, i, i);
2458
2459 /* Fisher-Yates shuffle */
2460 for (i = count - 1; i > 0; i--) {
2461 rand = prandom_u32_state(&state.rnd_state);
2462 rand %= (i + 1);
2463 swap_free_obj(page, i, rand);
2464 }
2465 } else {
2466 for (i = 0; i < count; i++)
2467 set_free_obj(page, i, next_random_slot(&state));
2468 }
2469
2470 if (OBJFREELIST_SLAB(cachep))
2471 set_free_obj(page, cachep->num - 1, objfreelist);
2472
2473 return true;
2474}
2475#else
2476static inline bool shuffle_freelist(struct kmem_cache *cachep,
2477 struct page *page)
2478{
2479 return false;
2480}
2481#endif /* CONFIG_SLAB_FREELIST_RANDOM */
2482
2483static void cache_init_objs(struct kmem_cache *cachep,
2484 struct page *page)
2485{
2486 int i;
2487 void *objp;
2488 bool shuffled;
2489
2490 cache_init_objs_debug(cachep, page);
2491
2492 /* Try to randomize the freelist if enabled */
2493 shuffled = shuffle_freelist(cachep, page);
2494
2495 if (!shuffled && OBJFREELIST_SLAB(cachep)) {
2496 page->freelist = index_to_obj(cachep, page, cachep->num - 1) +
2497 obj_offset(cachep);
2498 }
2499
2500 for (i = 0; i < cachep->num; i++) {
2501 objp = index_to_obj(cachep, page, i);
2502 objp = kasan_init_slab_obj(cachep, objp);
2503
2504 /* constructor could break poison info */
2505 if (DEBUG == 0 && cachep->ctor) {
2506 kasan_unpoison_object_data(cachep, objp);
2507 cachep->ctor(objp);
2508 kasan_poison_object_data(cachep, objp);
2509 }
2510
2511 if (!shuffled)
2512 set_free_obj(page, i, i);
2513 }
2514}
2515
2516static void *slab_get_obj(struct kmem_cache *cachep, struct page *page)
2517{
2518 void *objp;
2519
2520 objp = index_to_obj(cachep, page, get_free_obj(page, page->active));
2521 page->active++;
2522
2523 return objp;
2524}
2525
2526static void slab_put_obj(struct kmem_cache *cachep,
2527 struct page *page, void *objp)
2528{
2529 unsigned int objnr = obj_to_index(cachep, page, objp);
2530#if DEBUG
2531 unsigned int i;
2532
2533 /* Verify double free bug */
2534 for (i = page->active; i < cachep->num; i++) {
2535 if (get_free_obj(page, i) == objnr) {
2536 pr_err("slab: double free detected in cache '%s', objp %px\n",
2537 cachep->name, objp);
2538 BUG();
2539 }
2540 }
2541#endif
2542 page->active--;
2543 if (!page->freelist)
2544 page->freelist = objp + obj_offset(cachep);
2545
2546 set_free_obj(page, page->active, objnr);
2547}
2548
2549/*
2550 * Map pages beginning at addr to the given cache and slab. This is required
2551 * for the slab allocator to be able to lookup the cache and slab of a
2552 * virtual address for kfree, ksize, and slab debugging.
2553 */
2554static void slab_map_pages(struct kmem_cache *cache, struct page *page,
2555 void *freelist)
2556{
2557 page->slab_cache = cache;
2558 page->freelist = freelist;
2559}
2560
2561/*
2562 * Grow (by 1) the number of slabs within a cache. This is called by
2563 * kmem_cache_alloc() when there are no active objs left in a cache.
2564 */
2565static struct page *cache_grow_begin(struct kmem_cache *cachep,
2566 gfp_t flags, int nodeid)
2567{
2568 void *freelist;
2569 size_t offset;
2570 gfp_t local_flags;
2571 int page_node;
2572 struct kmem_cache_node *n;
2573 struct page *page;
2574
2575 /*
2576 * Be lazy and only check for valid flags here, keeping it out of the
2577 * critical path in kmem_cache_alloc().
2578 */
2579 if (unlikely(flags & GFP_SLAB_BUG_MASK))
2580 flags = kmalloc_fix_flags(flags);
2581
2582 WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO));
2583 local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
2584
2585 check_irq_off();
2586 if (gfpflags_allow_blocking(local_flags))
2587 local_irq_enable();
2588
2589 /*
2590 * Get mem for the objs. Attempt to allocate a physical page from
2591 * 'nodeid'.
2592 */
2593 page = kmem_getpages(cachep, local_flags, nodeid);
2594 if (!page)
2595 goto failed;
2596
2597 page_node = page_to_nid(page);
2598 n = get_node(cachep, page_node);
2599
2600 /* Get colour for the slab, and cal the next value. */
2601 n->colour_next++;
2602 if (n->colour_next >= cachep->colour)
2603 n->colour_next = 0;
2604
2605 offset = n->colour_next;
2606 if (offset >= cachep->colour)
2607 offset = 0;
2608
2609 offset *= cachep->colour_off;
2610
2611 /*
2612 * Call kasan_poison_slab() before calling alloc_slabmgmt(), so
2613 * page_address() in the latter returns a non-tagged pointer,
2614 * as it should be for slab pages.
2615 */
2616 kasan_poison_slab(page);
2617
2618 /* Get slab management. */
2619 freelist = alloc_slabmgmt(cachep, page, offset,
2620 local_flags & ~GFP_CONSTRAINT_MASK, page_node);
2621 if (OFF_SLAB(cachep) && !freelist)
2622 goto opps1;
2623
2624 slab_map_pages(cachep, page, freelist);
2625
2626 cache_init_objs(cachep, page);
2627
2628 if (gfpflags_allow_blocking(local_flags))
2629 local_irq_disable();
2630
2631 return page;
2632
2633opps1:
2634 kmem_freepages(cachep, page);
2635failed:
2636 if (gfpflags_allow_blocking(local_flags))
2637 local_irq_disable();
2638 return NULL;
2639}
2640
2641static void cache_grow_end(struct kmem_cache *cachep, struct page *page)
2642{
2643 struct kmem_cache_node *n;
2644 void *list = NULL;
2645
2646 check_irq_off();
2647
2648 if (!page)
2649 return;
2650
2651 INIT_LIST_HEAD(&page->slab_list);
2652 n = get_node(cachep, page_to_nid(page));
2653
2654 spin_lock(&n->list_lock);
2655 n->total_slabs++;
2656 if (!page->active) {
2657 list_add_tail(&page->slab_list, &n->slabs_free);
2658 n->free_slabs++;
2659 } else
2660 fixup_slab_list(cachep, n, page, &list);
2661
2662 STATS_INC_GROWN(cachep);
2663 n->free_objects += cachep->num - page->active;
2664 spin_unlock(&n->list_lock);
2665
2666 fixup_objfreelist_debug(cachep, &list);
2667}
2668
2669#if DEBUG
2670
2671/*
2672 * Perform extra freeing checks:
2673 * - detect bad pointers.
2674 * - POISON/RED_ZONE checking
2675 */
2676static void kfree_debugcheck(const void *objp)
2677{
2678 if (!virt_addr_valid(objp)) {
2679 pr_err("kfree_debugcheck: out of range ptr %lxh\n",
2680 (unsigned long)objp);
2681 BUG();
2682 }
2683}
2684
2685static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
2686{
2687 unsigned long long redzone1, redzone2;
2688
2689 redzone1 = *dbg_redzone1(cache, obj);
2690 redzone2 = *dbg_redzone2(cache, obj);
2691
2692 /*
2693 * Redzone is ok.
2694 */
2695 if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
2696 return;
2697
2698 if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
2699 slab_error(cache, "double free detected");
2700 else
2701 slab_error(cache, "memory outside object was overwritten");
2702
2703 pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n",
2704 obj, redzone1, redzone2);
2705}
2706
2707static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
2708 unsigned long caller)
2709{
2710 unsigned int objnr;
2711 struct page *page;
2712
2713 BUG_ON(virt_to_cache(objp) != cachep);
2714
2715 objp -= obj_offset(cachep);
2716 kfree_debugcheck(objp);
2717 page = virt_to_head_page(objp);
2718
2719 if (cachep->flags & SLAB_RED_ZONE) {
2720 verify_redzone_free(cachep, objp);
2721 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2722 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2723 }
2724 if (cachep->flags & SLAB_STORE_USER)
2725 *dbg_userword(cachep, objp) = (void *)caller;
2726
2727 objnr = obj_to_index(cachep, page, objp);
2728
2729 BUG_ON(objnr >= cachep->num);
2730 BUG_ON(objp != index_to_obj(cachep, page, objnr));
2731
2732 if (cachep->flags & SLAB_POISON) {
2733 poison_obj(cachep, objp, POISON_FREE);
2734 slab_kernel_map(cachep, objp, 0);
2735 }
2736 return objp;
2737}
2738
2739#else
2740#define kfree_debugcheck(x) do { } while(0)
2741#define cache_free_debugcheck(x, objp, z) (objp)
2742#endif
2743
2744static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
2745 void **list)
2746{
2747#if DEBUG
2748 void *next = *list;
2749 void *objp;
2750
2751 while (next) {
2752 objp = next - obj_offset(cachep);
2753 next = *(void **)next;
2754 poison_obj(cachep, objp, POISON_FREE);
2755 }
2756#endif
2757}
2758
2759static inline void fixup_slab_list(struct kmem_cache *cachep,
2760 struct kmem_cache_node *n, struct page *page,
2761 void **list)
2762{
2763 /* move slabp to correct slabp list: */
2764 list_del(&page->slab_list);
2765 if (page->active == cachep->num) {
2766 list_add(&page->slab_list, &n->slabs_full);
2767 if (OBJFREELIST_SLAB(cachep)) {
2768#if DEBUG
2769 /* Poisoning will be done without holding the lock */
2770 if (cachep->flags & SLAB_POISON) {
2771 void **objp = page->freelist;
2772
2773 *objp = *list;
2774 *list = objp;
2775 }
2776#endif
2777 page->freelist = NULL;
2778 }
2779 } else
2780 list_add(&page->slab_list, &n->slabs_partial);
2781}
2782
2783/* Try to find non-pfmemalloc slab if needed */
2784static noinline struct page *get_valid_first_slab(struct kmem_cache_node *n,
2785 struct page *page, bool pfmemalloc)
2786{
2787 if (!page)
2788 return NULL;
2789
2790 if (pfmemalloc)
2791 return page;
2792
2793 if (!PageSlabPfmemalloc(page))
2794 return page;
2795
2796 /* No need to keep pfmemalloc slab if we have enough free objects */
2797 if (n->free_objects > n->free_limit) {
2798 ClearPageSlabPfmemalloc(page);
2799 return page;
2800 }
2801
2802 /* Move pfmemalloc slab to the end of list to speed up next search */
2803 list_del(&page->slab_list);
2804 if (!page->active) {
2805 list_add_tail(&page->slab_list, &n->slabs_free);
2806 n->free_slabs++;
2807 } else
2808 list_add_tail(&page->slab_list, &n->slabs_partial);
2809
2810 list_for_each_entry(page, &n->slabs_partial, slab_list) {
2811 if (!PageSlabPfmemalloc(page))
2812 return page;
2813 }
2814
2815 n->free_touched = 1;
2816 list_for_each_entry(page, &n->slabs_free, slab_list) {
2817 if (!PageSlabPfmemalloc(page)) {
2818 n->free_slabs--;
2819 return page;
2820 }
2821 }
2822
2823 return NULL;
2824}
2825
2826static struct page *get_first_slab(struct kmem_cache_node *n, bool pfmemalloc)
2827{
2828 struct page *page;
2829
2830 assert_spin_locked(&n->list_lock);
2831 page = list_first_entry_or_null(&n->slabs_partial, struct page,
2832 slab_list);
2833 if (!page) {
2834 n->free_touched = 1;
2835 page = list_first_entry_or_null(&n->slabs_free, struct page,
2836 slab_list);
2837 if (page)
2838 n->free_slabs--;
2839 }
2840
2841 if (sk_memalloc_socks())
2842 page = get_valid_first_slab(n, page, pfmemalloc);
2843
2844 return page;
2845}
2846
2847static noinline void *cache_alloc_pfmemalloc(struct kmem_cache *cachep,
2848 struct kmem_cache_node *n, gfp_t flags)
2849{
2850 struct page *page;
2851 void *obj;
2852 void *list = NULL;
2853
2854 if (!gfp_pfmemalloc_allowed(flags))
2855 return NULL;
2856
2857 spin_lock(&n->list_lock);
2858 page = get_first_slab(n, true);
2859 if (!page) {
2860 spin_unlock(&n->list_lock);
2861 return NULL;
2862 }
2863
2864 obj = slab_get_obj(cachep, page);
2865 n->free_objects--;
2866
2867 fixup_slab_list(cachep, n, page, &list);
2868
2869 spin_unlock(&n->list_lock);
2870 fixup_objfreelist_debug(cachep, &list);
2871
2872 return obj;
2873}
2874
2875/*
2876 * Slab list should be fixed up by fixup_slab_list() for existing slab
2877 * or cache_grow_end() for new slab
2878 */
2879static __always_inline int alloc_block(struct kmem_cache *cachep,
2880 struct array_cache *ac, struct page *page, int batchcount)
2881{
2882 /*
2883 * There must be at least one object available for
2884 * allocation.
2885 */
2886 BUG_ON(page->active >= cachep->num);
2887
2888 while (page->active < cachep->num && batchcount--) {
2889 STATS_INC_ALLOCED(cachep);
2890 STATS_INC_ACTIVE(cachep);
2891 STATS_SET_HIGH(cachep);
2892
2893 ac->entry[ac->avail++] = slab_get_obj(cachep, page);
2894 }
2895
2896 return batchcount;
2897}
2898
2899static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
2900{
2901 int batchcount;
2902 struct kmem_cache_node *n;
2903 struct array_cache *ac, *shared;
2904 int node;
2905 void *list = NULL;
2906 struct page *page;
2907
2908 check_irq_off();
2909 node = numa_mem_id();
2910
2911 ac = cpu_cache_get(cachep);
2912 batchcount = ac->batchcount;
2913 if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
2914 /*
2915 * If there was little recent activity on this cache, then
2916 * perform only a partial refill. Otherwise we could generate
2917 * refill bouncing.
2918 */
2919 batchcount = BATCHREFILL_LIMIT;
2920 }
2921 n = get_node(cachep, node);
2922
2923 BUG_ON(ac->avail > 0 || !n);
2924 shared = READ_ONCE(n->shared);
2925 if (!n->free_objects && (!shared || !shared->avail))
2926 goto direct_grow;
2927
2928 spin_lock(&n->list_lock);
2929 shared = READ_ONCE(n->shared);
2930
2931 /* See if we can refill from the shared array */
2932 if (shared && transfer_objects(ac, shared, batchcount)) {
2933 shared->touched = 1;
2934 goto alloc_done;
2935 }
2936
2937 while (batchcount > 0) {
2938 /* Get slab alloc is to come from. */
2939 page = get_first_slab(n, false);
2940 if (!page)
2941 goto must_grow;
2942
2943 check_spinlock_acquired(cachep);
2944
2945 batchcount = alloc_block(cachep, ac, page, batchcount);
2946 fixup_slab_list(cachep, n, page, &list);
2947 }
2948
2949must_grow:
2950 n->free_objects -= ac->avail;
2951alloc_done:
2952 spin_unlock(&n->list_lock);
2953 fixup_objfreelist_debug(cachep, &list);
2954
2955direct_grow:
2956 if (unlikely(!ac->avail)) {
2957 /* Check if we can use obj in pfmemalloc slab */
2958 if (sk_memalloc_socks()) {
2959 void *obj = cache_alloc_pfmemalloc(cachep, n, flags);
2960
2961 if (obj)
2962 return obj;
2963 }
2964
2965 page = cache_grow_begin(cachep, gfp_exact_node(flags), node);
2966
2967 /*
2968 * cache_grow_begin() can reenable interrupts,
2969 * then ac could change.
2970 */
2971 ac = cpu_cache_get(cachep);
2972 if (!ac->avail && page)
2973 alloc_block(cachep, ac, page, batchcount);
2974 cache_grow_end(cachep, page);
2975
2976 if (!ac->avail)
2977 return NULL;
2978 }
2979 ac->touched = 1;
2980
2981 return ac->entry[--ac->avail];
2982}
2983
2984static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
2985 gfp_t flags)
2986{
2987 might_sleep_if(gfpflags_allow_blocking(flags));
2988}
2989
2990#if DEBUG
2991static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
2992 gfp_t flags, void *objp, unsigned long caller)
2993{
2994 WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO));
2995 if (!objp || is_kfence_address(objp))
2996 return objp;
2997 if (cachep->flags & SLAB_POISON) {
2998 check_poison_obj(cachep, objp);
2999 slab_kernel_map(cachep, objp, 1);
3000 poison_obj(cachep, objp, POISON_INUSE);
3001 }
3002 if (cachep->flags & SLAB_STORE_USER)
3003 *dbg_userword(cachep, objp) = (void *)caller;
3004
3005 if (cachep->flags & SLAB_RED_ZONE) {
3006 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
3007 *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
3008 slab_error(cachep, "double free, or memory outside object was overwritten");
3009 pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n",
3010 objp, *dbg_redzone1(cachep, objp),
3011 *dbg_redzone2(cachep, objp));
3012 }
3013 *dbg_redzone1(cachep, objp) = RED_ACTIVE;
3014 *dbg_redzone2(cachep, objp) = RED_ACTIVE;
3015 }
3016
3017 objp += obj_offset(cachep);
3018 if (cachep->ctor && cachep->flags & SLAB_POISON)
3019 cachep->ctor(objp);
3020 if (ARCH_SLAB_MINALIGN &&
3021 ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) {
3022 pr_err("0x%px: not aligned to ARCH_SLAB_MINALIGN=%d\n",
3023 objp, (int)ARCH_SLAB_MINALIGN);
3024 }
3025 return objp;
3026}
3027#else
3028#define cache_alloc_debugcheck_after(a, b, objp, d) (objp)
3029#endif
3030
3031static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3032{
3033 void *objp;
3034 struct array_cache *ac;
3035
3036 check_irq_off();
3037
3038 ac = cpu_cache_get(cachep);
3039 if (likely(ac->avail)) {
3040 ac->touched = 1;
3041 objp = ac->entry[--ac->avail];
3042
3043 STATS_INC_ALLOCHIT(cachep);
3044 goto out;
3045 }
3046
3047 STATS_INC_ALLOCMISS(cachep);
3048 objp = cache_alloc_refill(cachep, flags);
3049 /*
3050 * the 'ac' may be updated by cache_alloc_refill(),
3051 * and kmemleak_erase() requires its correct value.
3052 */
3053 ac = cpu_cache_get(cachep);
3054
3055out:
3056 /*
3057 * To avoid a false negative, if an object that is in one of the
3058 * per-CPU caches is leaked, we need to make sure kmemleak doesn't
3059 * treat the array pointers as a reference to the object.
3060 */
3061 if (objp)
3062 kmemleak_erase(&ac->entry[ac->avail]);
3063 return objp;
3064}
3065
3066#ifdef CONFIG_NUMA
3067/*
3068 * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set.
3069 *
3070 * If we are in_interrupt, then process context, including cpusets and
3071 * mempolicy, may not apply and should not be used for allocation policy.
3072 */
3073static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
3074{
3075 int nid_alloc, nid_here;
3076
3077 if (in_interrupt() || (flags & __GFP_THISNODE))
3078 return NULL;
3079 nid_alloc = nid_here = numa_mem_id();
3080 if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
3081 nid_alloc = cpuset_slab_spread_node();
3082 else if (current->mempolicy)
3083 nid_alloc = mempolicy_slab_node();
3084 if (nid_alloc != nid_here)
3085 return ____cache_alloc_node(cachep, flags, nid_alloc);
3086 return NULL;
3087}
3088
3089/*
3090 * Fallback function if there was no memory available and no objects on a
3091 * certain node and fall back is permitted. First we scan all the
3092 * available node for available objects. If that fails then we
3093 * perform an allocation without specifying a node. This allows the page
3094 * allocator to do its reclaim / fallback magic. We then insert the
3095 * slab into the proper nodelist and then allocate from it.
3096 */
3097static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3098{
3099 struct zonelist *zonelist;
3100 struct zoneref *z;
3101 struct zone *zone;
3102 enum zone_type highest_zoneidx = gfp_zone(flags);
3103 void *obj = NULL;
3104 struct page *page;
3105 int nid;
3106 unsigned int cpuset_mems_cookie;
3107
3108 if (flags & __GFP_THISNODE)
3109 return NULL;
3110
3111retry_cpuset:
3112 cpuset_mems_cookie = read_mems_allowed_begin();
3113 zonelist = node_zonelist(mempolicy_slab_node(), flags);
3114
3115retry:
3116 /*
3117 * Look through allowed nodes for objects available
3118 * from existing per node queues.
3119 */
3120 for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
3121 nid = zone_to_nid(zone);
3122
3123 if (cpuset_zone_allowed(zone, flags) &&
3124 get_node(cache, nid) &&
3125 get_node(cache, nid)->free_objects) {
3126 obj = ____cache_alloc_node(cache,
3127 gfp_exact_node(flags), nid);
3128 if (obj)
3129 break;
3130 }
3131 }
3132
3133 if (!obj) {
3134 /*
3135 * This allocation will be performed within the constraints
3136 * of the current cpuset / memory policy requirements.
3137 * We may trigger various forms of reclaim on the allowed
3138 * set and go into memory reserves if necessary.
3139 */
3140 page = cache_grow_begin(cache, flags, numa_mem_id());
3141 cache_grow_end(cache, page);
3142 if (page) {
3143 nid = page_to_nid(page);
3144 obj = ____cache_alloc_node(cache,
3145 gfp_exact_node(flags), nid);
3146
3147 /*
3148 * Another processor may allocate the objects in
3149 * the slab since we are not holding any locks.
3150 */
3151 if (!obj)
3152 goto retry;
3153 }
3154 }
3155
3156 if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie)))
3157 goto retry_cpuset;
3158 return obj;
3159}
3160
3161/*
3162 * A interface to enable slab creation on nodeid
3163 */
3164static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
3165 int nodeid)
3166{
3167 struct page *page;
3168 struct kmem_cache_node *n;
3169 void *obj = NULL;
3170 void *list = NULL;
3171
3172 VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES);
3173 n = get_node(cachep, nodeid);
3174 BUG_ON(!n);
3175
3176 check_irq_off();
3177 spin_lock(&n->list_lock);
3178 page = get_first_slab(n, false);
3179 if (!page)
3180 goto must_grow;
3181
3182 check_spinlock_acquired_node(cachep, nodeid);
3183
3184 STATS_INC_NODEALLOCS(cachep);
3185 STATS_INC_ACTIVE(cachep);
3186 STATS_SET_HIGH(cachep);
3187
3188 BUG_ON(page->active == cachep->num);
3189
3190 obj = slab_get_obj(cachep, page);
3191 n->free_objects--;
3192
3193 fixup_slab_list(cachep, n, page, &list);
3194
3195 spin_unlock(&n->list_lock);
3196 fixup_objfreelist_debug(cachep, &list);
3197 return obj;
3198
3199must_grow:
3200 spin_unlock(&n->list_lock);
3201 page = cache_grow_begin(cachep, gfp_exact_node(flags), nodeid);
3202 if (page) {
3203 /* This slab isn't counted yet so don't update free_objects */
3204 obj = slab_get_obj(cachep, page);
3205 }
3206 cache_grow_end(cachep, page);
3207
3208 return obj ? obj : fallback_alloc(cachep, flags);
3209}
3210
3211static __always_inline void *
3212slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, size_t orig_size,
3213 unsigned long caller)
3214{
3215 unsigned long save_flags;
3216 void *ptr;
3217 int slab_node = numa_mem_id();
3218 struct obj_cgroup *objcg = NULL;
3219 bool init = false;
3220
3221 flags &= gfp_allowed_mask;
3222 cachep = slab_pre_alloc_hook(cachep, &objcg, 1, flags);
3223 if (unlikely(!cachep))
3224 return NULL;
3225
3226 ptr = kfence_alloc(cachep, orig_size, flags);
3227 if (unlikely(ptr))
3228 goto out_hooks;
3229
3230 cache_alloc_debugcheck_before(cachep, flags);
3231 local_irq_save(save_flags);
3232
3233 if (nodeid == NUMA_NO_NODE)
3234 nodeid = slab_node;
3235
3236 if (unlikely(!get_node(cachep, nodeid))) {
3237 /* Node not bootstrapped yet */
3238 ptr = fallback_alloc(cachep, flags);
3239 goto out;
3240 }
3241
3242 if (nodeid == slab_node) {
3243 /*
3244 * Use the locally cached objects if possible.
3245 * However ____cache_alloc does not allow fallback
3246 * to other nodes. It may fail while we still have
3247 * objects on other nodes available.
3248 */
3249 ptr = ____cache_alloc(cachep, flags);
3250 if (ptr)
3251 goto out;
3252 }
3253 /* ___cache_alloc_node can fall back to other nodes */
3254 ptr = ____cache_alloc_node(cachep, flags, nodeid);
3255 out:
3256 local_irq_restore(save_flags);
3257 ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
3258 init = slab_want_init_on_alloc(flags, cachep);
3259
3260out_hooks:
3261 slab_post_alloc_hook(cachep, objcg, flags, 1, &ptr, init);
3262 return ptr;
3263}
3264
3265static __always_inline void *
3266__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
3267{
3268 void *objp;
3269
3270 if (current->mempolicy || cpuset_do_slab_mem_spread()) {
3271 objp = alternate_node_alloc(cache, flags);
3272 if (objp)
3273 goto out;
3274 }
3275 objp = ____cache_alloc(cache, flags);
3276
3277 /*
3278 * We may just have run out of memory on the local node.
3279 * ____cache_alloc_node() knows how to locate memory on other nodes
3280 */
3281 if (!objp)
3282 objp = ____cache_alloc_node(cache, flags, numa_mem_id());
3283
3284 out:
3285 return objp;
3286}
3287#else
3288
3289static __always_inline void *
3290__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3291{
3292 return ____cache_alloc(cachep, flags);
3293}
3294
3295#endif /* CONFIG_NUMA */
3296
3297static __always_inline void *
3298slab_alloc(struct kmem_cache *cachep, gfp_t flags, size_t orig_size, unsigned long caller)
3299{
3300 unsigned long save_flags;
3301 void *objp;
3302 struct obj_cgroup *objcg = NULL;
3303 bool init = false;
3304
3305 flags &= gfp_allowed_mask;
3306 cachep = slab_pre_alloc_hook(cachep, &objcg, 1, flags);
3307 if (unlikely(!cachep))
3308 return NULL;
3309
3310 objp = kfence_alloc(cachep, orig_size, flags);
3311 if (unlikely(objp))
3312 goto out;
3313
3314 cache_alloc_debugcheck_before(cachep, flags);
3315 local_irq_save(save_flags);
3316 objp = __do_cache_alloc(cachep, flags);
3317 local_irq_restore(save_flags);
3318 objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
3319 prefetchw(objp);
3320 init = slab_want_init_on_alloc(flags, cachep);
3321
3322out:
3323 slab_post_alloc_hook(cachep, objcg, flags, 1, &objp, init);
3324 return objp;
3325}
3326
3327/*
3328 * Caller needs to acquire correct kmem_cache_node's list_lock
3329 * @list: List of detached free slabs should be freed by caller
3330 */
3331static void free_block(struct kmem_cache *cachep, void **objpp,
3332 int nr_objects, int node, struct list_head *list)
3333{
3334 int i;
3335 struct kmem_cache_node *n = get_node(cachep, node);
3336 struct page *page;
3337
3338 n->free_objects += nr_objects;
3339
3340 for (i = 0; i < nr_objects; i++) {
3341 void *objp;
3342 struct page *page;
3343
3344 objp = objpp[i];
3345
3346 page = virt_to_head_page(objp);
3347 list_del(&page->slab_list);
3348 check_spinlock_acquired_node(cachep, node);
3349 slab_put_obj(cachep, page, objp);
3350 STATS_DEC_ACTIVE(cachep);
3351
3352 /* fixup slab chains */
3353 if (page->active == 0) {
3354 list_add(&page->slab_list, &n->slabs_free);
3355 n->free_slabs++;
3356 } else {
3357 /* Unconditionally move a slab to the end of the
3358 * partial list on free - maximum time for the
3359 * other objects to be freed, too.
3360 */
3361 list_add_tail(&page->slab_list, &n->slabs_partial);
3362 }
3363 }
3364
3365 while (n->free_objects > n->free_limit && !list_empty(&n->slabs_free)) {
3366 n->free_objects -= cachep->num;
3367
3368 page = list_last_entry(&n->slabs_free, struct page, slab_list);
3369 list_move(&page->slab_list, list);
3370 n->free_slabs--;
3371 n->total_slabs--;
3372 }
3373}
3374
3375static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
3376{
3377 int batchcount;
3378 struct kmem_cache_node *n;
3379 int node = numa_mem_id();
3380 LIST_HEAD(list);
3381
3382 batchcount = ac->batchcount;
3383
3384 check_irq_off();
3385 n = get_node(cachep, node);
3386 spin_lock(&n->list_lock);
3387 if (n->shared) {
3388 struct array_cache *shared_array = n->shared;
3389 int max = shared_array->limit - shared_array->avail;
3390 if (max) {
3391 if (batchcount > max)
3392 batchcount = max;
3393 memcpy(&(shared_array->entry[shared_array->avail]),
3394 ac->entry, sizeof(void *) * batchcount);
3395 shared_array->avail += batchcount;
3396 goto free_done;
3397 }
3398 }
3399
3400 free_block(cachep, ac->entry, batchcount, node, &list);
3401free_done:
3402#if STATS
3403 {
3404 int i = 0;
3405 struct page *page;
3406
3407 list_for_each_entry(page, &n->slabs_free, slab_list) {
3408 BUG_ON(page->active);
3409
3410 i++;
3411 }
3412 STATS_SET_FREEABLE(cachep, i);
3413 }
3414#endif
3415 spin_unlock(&n->list_lock);
3416 ac->avail -= batchcount;
3417 memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
3418 slabs_destroy(cachep, &list);
3419}
3420
3421/*
3422 * Release an obj back to its cache. If the obj has a constructed state, it must
3423 * be in this state _before_ it is released. Called with disabled ints.
3424 */
3425static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp,
3426 unsigned long caller)
3427{
3428 bool init;
3429
3430 if (is_kfence_address(objp)) {
3431 kmemleak_free_recursive(objp, cachep->flags);
3432 __kfence_free(objp);
3433 return;
3434 }
3435
3436 /*
3437 * As memory initialization might be integrated into KASAN,
3438 * kasan_slab_free and initialization memset must be
3439 * kept together to avoid discrepancies in behavior.
3440 */
3441 init = slab_want_init_on_free(cachep);
3442 if (init && !kasan_has_integrated_init())
3443 memset(objp, 0, cachep->object_size);
3444 /* KASAN might put objp into memory quarantine, delaying its reuse. */
3445 if (kasan_slab_free(cachep, objp, init))
3446 return;
3447
3448 /* Use KCSAN to help debug racy use-after-free. */
3449 if (!(cachep->flags & SLAB_TYPESAFE_BY_RCU))
3450 __kcsan_check_access(objp, cachep->object_size,
3451 KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT);
3452
3453 ___cache_free(cachep, objp, caller);
3454}
3455
3456void ___cache_free(struct kmem_cache *cachep, void *objp,
3457 unsigned long caller)
3458{
3459 struct array_cache *ac = cpu_cache_get(cachep);
3460
3461 check_irq_off();
3462 kmemleak_free_recursive(objp, cachep->flags);
3463 objp = cache_free_debugcheck(cachep, objp, caller);
3464 memcg_slab_free_hook(cachep, &objp, 1);
3465
3466 /*
3467 * Skip calling cache_free_alien() when the platform is not numa.
3468 * This will avoid cache misses that happen while accessing slabp (which
3469 * is per page memory reference) to get nodeid. Instead use a global
3470 * variable to skip the call, which is mostly likely to be present in
3471 * the cache.
3472 */
3473 if (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
3474 return;
3475
3476 if (ac->avail < ac->limit) {
3477 STATS_INC_FREEHIT(cachep);
3478 } else {
3479 STATS_INC_FREEMISS(cachep);
3480 cache_flusharray(cachep, ac);
3481 }
3482
3483 if (sk_memalloc_socks()) {
3484 struct page *page = virt_to_head_page(objp);
3485
3486 if (unlikely(PageSlabPfmemalloc(page))) {
3487 cache_free_pfmemalloc(cachep, page, objp);
3488 return;
3489 }
3490 }
3491
3492 __free_one(ac, objp);
3493}
3494
3495/**
3496 * kmem_cache_alloc - Allocate an object
3497 * @cachep: The cache to allocate from.
3498 * @flags: See kmalloc().
3499 *
3500 * Allocate an object from this cache. The flags are only relevant
3501 * if the cache has no available objects.
3502 *
3503 * Return: pointer to the new object or %NULL in case of error
3504 */
3505void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3506{
3507 void *ret = slab_alloc(cachep, flags, cachep->object_size, _RET_IP_);
3508
3509 trace_kmem_cache_alloc(_RET_IP_, ret,
3510 cachep->object_size, cachep->size, flags);
3511
3512 return ret;
3513}
3514EXPORT_SYMBOL(kmem_cache_alloc);
3515
3516static __always_inline void
3517cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags,
3518 size_t size, void **p, unsigned long caller)
3519{
3520 size_t i;
3521
3522 for (i = 0; i < size; i++)
3523 p[i] = cache_alloc_debugcheck_after(s, flags, p[i], caller);
3524}
3525
3526int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
3527 void **p)
3528{
3529 size_t i;
3530 struct obj_cgroup *objcg = NULL;
3531
3532 s = slab_pre_alloc_hook(s, &objcg, size, flags);
3533 if (!s)
3534 return 0;
3535
3536 cache_alloc_debugcheck_before(s, flags);
3537
3538 local_irq_disable();
3539 for (i = 0; i < size; i++) {
3540 void *objp = kfence_alloc(s, s->object_size, flags) ?: __do_cache_alloc(s, flags);
3541
3542 if (unlikely(!objp))
3543 goto error;
3544 p[i] = objp;
3545 }
3546 local_irq_enable();
3547
3548 cache_alloc_debugcheck_after_bulk(s, flags, size, p, _RET_IP_);
3549
3550 /*
3551 * memcg and kmem_cache debug support and memory initialization.
3552 * Done outside of the IRQ disabled section.
3553 */
3554 slab_post_alloc_hook(s, objcg, flags, size, p,
3555 slab_want_init_on_alloc(flags, s));
3556 /* FIXME: Trace call missing. Christoph would like a bulk variant */
3557 return size;
3558error:
3559 local_irq_enable();
3560 cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_);
3561 slab_post_alloc_hook(s, objcg, flags, i, p, false);
3562 __kmem_cache_free_bulk(s, i, p);
3563 return 0;
3564}
3565EXPORT_SYMBOL(kmem_cache_alloc_bulk);
3566
3567#ifdef CONFIG_TRACING
3568void *
3569kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
3570{
3571 void *ret;
3572
3573 ret = slab_alloc(cachep, flags, size, _RET_IP_);
3574
3575 ret = kasan_kmalloc(cachep, ret, size, flags);
3576 trace_kmalloc(_RET_IP_, ret,
3577 size, cachep->size, flags);
3578 return ret;
3579}
3580EXPORT_SYMBOL(kmem_cache_alloc_trace);
3581#endif
3582
3583#ifdef CONFIG_NUMA
3584/**
3585 * kmem_cache_alloc_node - Allocate an object on the specified node
3586 * @cachep: The cache to allocate from.
3587 * @flags: See kmalloc().
3588 * @nodeid: node number of the target node.
3589 *
3590 * Identical to kmem_cache_alloc but it will allocate memory on the given
3591 * node, which can improve the performance for cpu bound structures.
3592 *
3593 * Fallback to other node is possible if __GFP_THISNODE is not set.
3594 *
3595 * Return: pointer to the new object or %NULL in case of error
3596 */
3597void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
3598{
3599 void *ret = slab_alloc_node(cachep, flags, nodeid, cachep->object_size, _RET_IP_);
3600
3601 trace_kmem_cache_alloc_node(_RET_IP_, ret,
3602 cachep->object_size, cachep->size,
3603 flags, nodeid);
3604
3605 return ret;
3606}
3607EXPORT_SYMBOL(kmem_cache_alloc_node);
3608
3609#ifdef CONFIG_TRACING
3610void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
3611 gfp_t flags,
3612 int nodeid,
3613 size_t size)
3614{
3615 void *ret;
3616
3617 ret = slab_alloc_node(cachep, flags, nodeid, size, _RET_IP_);
3618
3619 ret = kasan_kmalloc(cachep, ret, size, flags);
3620 trace_kmalloc_node(_RET_IP_, ret,
3621 size, cachep->size,
3622 flags, nodeid);
3623 return ret;
3624}
3625EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
3626#endif
3627
3628static __always_inline void *
3629__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
3630{
3631 struct kmem_cache *cachep;
3632 void *ret;
3633
3634 if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
3635 return NULL;
3636 cachep = kmalloc_slab(size, flags);
3637 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3638 return cachep;
3639 ret = kmem_cache_alloc_node_trace(cachep, flags, node, size);
3640 ret = kasan_kmalloc(cachep, ret, size, flags);
3641
3642 return ret;
3643}
3644
3645void *__kmalloc_node(size_t size, gfp_t flags, int node)
3646{
3647 return __do_kmalloc_node(size, flags, node, _RET_IP_);
3648}
3649EXPORT_SYMBOL(__kmalloc_node);
3650
3651void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
3652 int node, unsigned long caller)
3653{
3654 return __do_kmalloc_node(size, flags, node, caller);
3655}
3656EXPORT_SYMBOL(__kmalloc_node_track_caller);
3657#endif /* CONFIG_NUMA */
3658
3659#ifdef CONFIG_PRINTK
3660void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page)
3661{
3662 struct kmem_cache *cachep;
3663 unsigned int objnr;
3664 void *objp;
3665
3666 kpp->kp_ptr = object;
3667 kpp->kp_page = page;
3668 cachep = page->slab_cache;
3669 kpp->kp_slab_cache = cachep;
3670 objp = object - obj_offset(cachep);
3671 kpp->kp_data_offset = obj_offset(cachep);
3672 page = virt_to_head_page(objp);
3673 objnr = obj_to_index(cachep, page, objp);
3674 objp = index_to_obj(cachep, page, objnr);
3675 kpp->kp_objp = objp;
3676 if (DEBUG && cachep->flags & SLAB_STORE_USER)
3677 kpp->kp_ret = *dbg_userword(cachep, objp);
3678}
3679#endif
3680
3681/**
3682 * __do_kmalloc - allocate memory
3683 * @size: how many bytes of memory are required.
3684 * @flags: the type of memory to allocate (see kmalloc).
3685 * @caller: function caller for debug tracking of the caller
3686 *
3687 * Return: pointer to the allocated memory or %NULL in case of error
3688 */
3689static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
3690 unsigned long caller)
3691{
3692 struct kmem_cache *cachep;
3693 void *ret;
3694
3695 if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
3696 return NULL;
3697 cachep = kmalloc_slab(size, flags);
3698 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3699 return cachep;
3700 ret = slab_alloc(cachep, flags, size, caller);
3701
3702 ret = kasan_kmalloc(cachep, ret, size, flags);
3703 trace_kmalloc(caller, ret,
3704 size, cachep->size, flags);
3705
3706 return ret;
3707}
3708
3709void *__kmalloc(size_t size, gfp_t flags)
3710{
3711 return __do_kmalloc(size, flags, _RET_IP_);
3712}
3713EXPORT_SYMBOL(__kmalloc);
3714
3715void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller)
3716{
3717 return __do_kmalloc(size, flags, caller);
3718}
3719EXPORT_SYMBOL(__kmalloc_track_caller);
3720
3721/**
3722 * kmem_cache_free - Deallocate an object
3723 * @cachep: The cache the allocation was from.
3724 * @objp: The previously allocated object.
3725 *
3726 * Free an object which was previously allocated from this
3727 * cache.
3728 */
3729void kmem_cache_free(struct kmem_cache *cachep, void *objp)
3730{
3731 unsigned long flags;
3732 cachep = cache_from_obj(cachep, objp);
3733 if (!cachep)
3734 return;
3735
3736 local_irq_save(flags);
3737 debug_check_no_locks_freed(objp, cachep->object_size);
3738 if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
3739 debug_check_no_obj_freed(objp, cachep->object_size);
3740 __cache_free(cachep, objp, _RET_IP_);
3741 local_irq_restore(flags);
3742
3743 trace_kmem_cache_free(_RET_IP_, objp, cachep->name);
3744}
3745EXPORT_SYMBOL(kmem_cache_free);
3746
3747void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p)
3748{
3749 struct kmem_cache *s;
3750 size_t i;
3751
3752 local_irq_disable();
3753 for (i = 0; i < size; i++) {
3754 void *objp = p[i];
3755
3756 if (!orig_s) /* called via kfree_bulk */
3757 s = virt_to_cache(objp);
3758 else
3759 s = cache_from_obj(orig_s, objp);
3760 if (!s)
3761 continue;
3762
3763 debug_check_no_locks_freed(objp, s->object_size);
3764 if (!(s->flags & SLAB_DEBUG_OBJECTS))
3765 debug_check_no_obj_freed(objp, s->object_size);
3766
3767 __cache_free(s, objp, _RET_IP_);
3768 }
3769 local_irq_enable();
3770
3771 /* FIXME: add tracing */
3772}
3773EXPORT_SYMBOL(kmem_cache_free_bulk);
3774
3775/**
3776 * kfree - free previously allocated memory
3777 * @objp: pointer returned by kmalloc.
3778 *
3779 * If @objp is NULL, no operation is performed.
3780 *
3781 * Don't free memory not originally allocated by kmalloc()
3782 * or you will run into trouble.
3783 */
3784void kfree(const void *objp)
3785{
3786 struct kmem_cache *c;
3787 unsigned long flags;
3788
3789 trace_kfree(_RET_IP_, objp);
3790
3791 if (unlikely(ZERO_OR_NULL_PTR(objp)))
3792 return;
3793 local_irq_save(flags);
3794 kfree_debugcheck(objp);
3795 c = virt_to_cache(objp);
3796 if (!c) {
3797 local_irq_restore(flags);
3798 return;
3799 }
3800 debug_check_no_locks_freed(objp, c->object_size);
3801
3802 debug_check_no_obj_freed(objp, c->object_size);
3803 __cache_free(c, (void *)objp, _RET_IP_);
3804 local_irq_restore(flags);
3805}
3806EXPORT_SYMBOL(kfree);
3807
3808/*
3809 * This initializes kmem_cache_node or resizes various caches for all nodes.
3810 */
3811static int setup_kmem_cache_nodes(struct kmem_cache *cachep, gfp_t gfp)
3812{
3813 int ret;
3814 int node;
3815 struct kmem_cache_node *n;
3816
3817 for_each_online_node(node) {
3818 ret = setup_kmem_cache_node(cachep, node, gfp, true);
3819 if (ret)
3820 goto fail;
3821
3822 }
3823
3824 return 0;
3825
3826fail:
3827 if (!cachep->list.next) {
3828 /* Cache is not active yet. Roll back what we did */
3829 node--;
3830 while (node >= 0) {
3831 n = get_node(cachep, node);
3832 if (n) {
3833 kfree(n->shared);
3834 free_alien_cache(n->alien);
3835 kfree(n);
3836 cachep->node[node] = NULL;
3837 }
3838 node--;
3839 }
3840 }
3841 return -ENOMEM;
3842}
3843
3844/* Always called with the slab_mutex held */
3845static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
3846 int batchcount, int shared, gfp_t gfp)
3847{
3848 struct array_cache __percpu *cpu_cache, *prev;
3849 int cpu;
3850
3851 cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount);
3852 if (!cpu_cache)
3853 return -ENOMEM;
3854
3855 prev = cachep->cpu_cache;
3856 cachep->cpu_cache = cpu_cache;
3857 /*
3858 * Without a previous cpu_cache there's no need to synchronize remote
3859 * cpus, so skip the IPIs.
3860 */
3861 if (prev)
3862 kick_all_cpus_sync();
3863
3864 check_irq_on();
3865 cachep->batchcount = batchcount;
3866 cachep->limit = limit;
3867 cachep->shared = shared;
3868
3869 if (!prev)
3870 goto setup_node;
3871
3872 for_each_online_cpu(cpu) {
3873 LIST_HEAD(list);
3874 int node;
3875 struct kmem_cache_node *n;
3876 struct array_cache *ac = per_cpu_ptr(prev, cpu);
3877
3878 node = cpu_to_mem(cpu);
3879 n = get_node(cachep, node);
3880 spin_lock_irq(&n->list_lock);
3881 free_block(cachep, ac->entry, ac->avail, node, &list);
3882 spin_unlock_irq(&n->list_lock);
3883 slabs_destroy(cachep, &list);
3884 }
3885 free_percpu(prev);
3886
3887setup_node:
3888 return setup_kmem_cache_nodes(cachep, gfp);
3889}
3890
3891/* Called with slab_mutex held always */
3892static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
3893{
3894 int err;
3895 int limit = 0;
3896 int shared = 0;
3897 int batchcount = 0;
3898
3899 err = cache_random_seq_create(cachep, cachep->num, gfp);
3900 if (err)
3901 goto end;
3902
3903 if (limit && shared && batchcount)
3904 goto skip_setup;
3905 /*
3906 * The head array serves three purposes:
3907 * - create a LIFO ordering, i.e. return objects that are cache-warm
3908 * - reduce the number of spinlock operations.
3909 * - reduce the number of linked list operations on the slab and
3910 * bufctl chains: array operations are cheaper.
3911 * The numbers are guessed, we should auto-tune as described by
3912 * Bonwick.
3913 */
3914 if (cachep->size > 131072)
3915 limit = 1;
3916 else if (cachep->size > PAGE_SIZE)
3917 limit = 8;
3918 else if (cachep->size > 1024)
3919 limit = 24;
3920 else if (cachep->size > 256)
3921 limit = 54;
3922 else
3923 limit = 120;
3924
3925 /*
3926 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3927 * allocation behaviour: Most allocs on one cpu, most free operations
3928 * on another cpu. For these cases, an efficient object passing between
3929 * cpus is necessary. This is provided by a shared array. The array
3930 * replaces Bonwick's magazine layer.
3931 * On uniprocessor, it's functionally equivalent (but less efficient)
3932 * to a larger limit. Thus disabled by default.
3933 */
3934 shared = 0;
3935 if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1)
3936 shared = 8;
3937
3938#if DEBUG
3939 /*
3940 * With debugging enabled, large batchcount lead to excessively long
3941 * periods with disabled local interrupts. Limit the batchcount
3942 */
3943 if (limit > 32)
3944 limit = 32;
3945#endif
3946 batchcount = (limit + 1) / 2;
3947skip_setup:
3948 err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
3949end:
3950 if (err)
3951 pr_err("enable_cpucache failed for %s, error %d\n",
3952 cachep->name, -err);
3953 return err;
3954}
3955
3956/*
3957 * Drain an array if it contains any elements taking the node lock only if
3958 * necessary. Note that the node listlock also protects the array_cache
3959 * if drain_array() is used on the shared array.
3960 */
3961static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n,
3962 struct array_cache *ac, int node)
3963{
3964 LIST_HEAD(list);
3965
3966 /* ac from n->shared can be freed if we don't hold the slab_mutex. */
3967 check_mutex_acquired();
3968
3969 if (!ac || !ac->avail)
3970 return;
3971
3972 if (ac->touched) {
3973 ac->touched = 0;
3974 return;
3975 }
3976
3977 spin_lock_irq(&n->list_lock);
3978 drain_array_locked(cachep, ac, node, false, &list);
3979 spin_unlock_irq(&n->list_lock);
3980
3981 slabs_destroy(cachep, &list);
3982}
3983
3984/**
3985 * cache_reap - Reclaim memory from caches.
3986 * @w: work descriptor
3987 *
3988 * Called from workqueue/eventd every few seconds.
3989 * Purpose:
3990 * - clear the per-cpu caches for this CPU.
3991 * - return freeable pages to the main free memory pool.
3992 *
3993 * If we cannot acquire the cache chain mutex then just give up - we'll try
3994 * again on the next iteration.
3995 */
3996static void cache_reap(struct work_struct *w)
3997{
3998 struct kmem_cache *searchp;
3999 struct kmem_cache_node *n;
4000 int node = numa_mem_id();
4001 struct delayed_work *work = to_delayed_work(w);
4002
4003 if (!mutex_trylock(&slab_mutex))
4004 /* Give up. Setup the next iteration. */
4005 goto out;
4006
4007 list_for_each_entry(searchp, &slab_caches, list) {
4008 check_irq_on();
4009
4010 /*
4011 * We only take the node lock if absolutely necessary and we
4012 * have established with reasonable certainty that
4013 * we can do some work if the lock was obtained.
4014 */
4015 n = get_node(searchp, node);
4016
4017 reap_alien(searchp, n);
4018
4019 drain_array(searchp, n, cpu_cache_get(searchp), node);
4020
4021 /*
4022 * These are racy checks but it does not matter
4023 * if we skip one check or scan twice.
4024 */
4025 if (time_after(n->next_reap, jiffies))
4026 goto next;
4027
4028 n->next_reap = jiffies + REAPTIMEOUT_NODE;
4029
4030 drain_array(searchp, n, n->shared, node);
4031
4032 if (n->free_touched)
4033 n->free_touched = 0;
4034 else {
4035 int freed;
4036
4037 freed = drain_freelist(searchp, n, (n->free_limit +
4038 5 * searchp->num - 1) / (5 * searchp->num));
4039 STATS_ADD_REAPED(searchp, freed);
4040 }
4041next:
4042 cond_resched();
4043 }
4044 check_irq_on();
4045 mutex_unlock(&slab_mutex);
4046 next_reap_node();
4047out:
4048 /* Set up the next iteration */
4049 schedule_delayed_work_on(smp_processor_id(), work,
4050 round_jiffies_relative(REAPTIMEOUT_AC));
4051}
4052
4053void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
4054{
4055 unsigned long active_objs, num_objs, active_slabs;
4056 unsigned long total_slabs = 0, free_objs = 0, shared_avail = 0;
4057 unsigned long free_slabs = 0;
4058 int node;
4059 struct kmem_cache_node *n;
4060
4061 for_each_kmem_cache_node(cachep, node, n) {
4062 check_irq_on();
4063 spin_lock_irq(&n->list_lock);
4064
4065 total_slabs += n->total_slabs;
4066 free_slabs += n->free_slabs;
4067 free_objs += n->free_objects;
4068
4069 if (n->shared)
4070 shared_avail += n->shared->avail;
4071
4072 spin_unlock_irq(&n->list_lock);
4073 }
4074 num_objs = total_slabs * cachep->num;
4075 active_slabs = total_slabs - free_slabs;
4076 active_objs = num_objs - free_objs;
4077
4078 sinfo->active_objs = active_objs;
4079 sinfo->num_objs = num_objs;
4080 sinfo->active_slabs = active_slabs;
4081 sinfo->num_slabs = total_slabs;
4082 sinfo->shared_avail = shared_avail;
4083 sinfo->limit = cachep->limit;
4084 sinfo->batchcount = cachep->batchcount;
4085 sinfo->shared = cachep->shared;
4086 sinfo->objects_per_slab = cachep->num;
4087 sinfo->cache_order = cachep->gfporder;
4088}
4089
4090void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep)
4091{
4092#if STATS
4093 { /* node stats */
4094 unsigned long high = cachep->high_mark;
4095 unsigned long allocs = cachep->num_allocations;
4096 unsigned long grown = cachep->grown;
4097 unsigned long reaped = cachep->reaped;
4098 unsigned long errors = cachep->errors;
4099 unsigned long max_freeable = cachep->max_freeable;
4100 unsigned long node_allocs = cachep->node_allocs;
4101 unsigned long node_frees = cachep->node_frees;
4102 unsigned long overflows = cachep->node_overflow;
4103
4104 seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu",
4105 allocs, high, grown,
4106 reaped, errors, max_freeable, node_allocs,
4107 node_frees, overflows);
4108 }
4109 /* cpu stats */
4110 {
4111 unsigned long allochit = atomic_read(&cachep->allochit);
4112 unsigned long allocmiss = atomic_read(&cachep->allocmiss);
4113 unsigned long freehit = atomic_read(&cachep->freehit);
4114 unsigned long freemiss = atomic_read(&cachep->freemiss);
4115
4116 seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
4117 allochit, allocmiss, freehit, freemiss);
4118 }
4119#endif
4120}
4121
4122#define MAX_SLABINFO_WRITE 128
4123/**
4124 * slabinfo_write - Tuning for the slab allocator
4125 * @file: unused
4126 * @buffer: user buffer
4127 * @count: data length
4128 * @ppos: unused
4129 *
4130 * Return: %0 on success, negative error code otherwise.
4131 */
4132ssize_t slabinfo_write(struct file *file, const char __user *buffer,
4133 size_t count, loff_t *ppos)
4134{
4135 char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
4136 int limit, batchcount, shared, res;
4137 struct kmem_cache *cachep;
4138
4139 if (count > MAX_SLABINFO_WRITE)
4140 return -EINVAL;
4141 if (copy_from_user(&kbuf, buffer, count))
4142 return -EFAULT;
4143 kbuf[MAX_SLABINFO_WRITE] = '\0';
4144
4145 tmp = strchr(kbuf, ' ');
4146 if (!tmp)
4147 return -EINVAL;
4148 *tmp = '\0';
4149 tmp++;
4150 if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
4151 return -EINVAL;
4152
4153 /* Find the cache in the chain of caches. */
4154 mutex_lock(&slab_mutex);
4155 res = -EINVAL;
4156 list_for_each_entry(cachep, &slab_caches, list) {
4157 if (!strcmp(cachep->name, kbuf)) {
4158 if (limit < 1 || batchcount < 1 ||
4159 batchcount > limit || shared < 0) {
4160 res = 0;
4161 } else {
4162 res = do_tune_cpucache(cachep, limit,
4163 batchcount, shared,
4164 GFP_KERNEL);
4165 }
4166 break;
4167 }
4168 }
4169 mutex_unlock(&slab_mutex);
4170 if (res >= 0)
4171 res = count;
4172 return res;
4173}
4174
4175#ifdef CONFIG_HARDENED_USERCOPY
4176/*
4177 * Rejects incorrectly sized objects and objects that are to be copied
4178 * to/from userspace but do not fall entirely within the containing slab
4179 * cache's usercopy region.
4180 *
4181 * Returns NULL if check passes, otherwise const char * to name of cache
4182 * to indicate an error.
4183 */
4184void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
4185 bool to_user)
4186{
4187 struct kmem_cache *cachep;
4188 unsigned int objnr;
4189 unsigned long offset;
4190
4191 ptr = kasan_reset_tag(ptr);
4192
4193 /* Find and validate object. */
4194 cachep = page->slab_cache;
4195 objnr = obj_to_index(cachep, page, (void *)ptr);
4196 BUG_ON(objnr >= cachep->num);
4197
4198 /* Find offset within object. */
4199 if (is_kfence_address(ptr))
4200 offset = ptr - kfence_object_start(ptr);
4201 else
4202 offset = ptr - index_to_obj(cachep, page, objnr) - obj_offset(cachep);
4203
4204 /* Allow address range falling entirely within usercopy region. */
4205 if (offset >= cachep->useroffset &&
4206 offset - cachep->useroffset <= cachep->usersize &&
4207 n <= cachep->useroffset - offset + cachep->usersize)
4208 return;
4209
4210 /*
4211 * If the copy is still within the allocated object, produce
4212 * a warning instead of rejecting the copy. This is intended
4213 * to be a temporary method to find any missing usercopy
4214 * whitelists.
4215 */
4216 if (usercopy_fallback &&
4217 offset <= cachep->object_size &&
4218 n <= cachep->object_size - offset) {
4219 usercopy_warn("SLAB object", cachep->name, to_user, offset, n);
4220 return;
4221 }
4222
4223 usercopy_abort("SLAB object", cachep->name, to_user, offset, n);
4224}
4225#endif /* CONFIG_HARDENED_USERCOPY */
4226
4227/**
4228 * __ksize -- Uninstrumented ksize.
4229 * @objp: pointer to the object
4230 *
4231 * Unlike ksize(), __ksize() is uninstrumented, and does not provide the same
4232 * safety checks as ksize() with KASAN instrumentation enabled.
4233 *
4234 * Return: size of the actual memory used by @objp in bytes
4235 */
4236size_t __ksize(const void *objp)
4237{
4238 struct kmem_cache *c;
4239 size_t size;
4240
4241 BUG_ON(!objp);
4242 if (unlikely(objp == ZERO_SIZE_PTR))
4243 return 0;
4244
4245 c = virt_to_cache(objp);
4246 size = c ? c->object_size : 0;
4247
4248 return size;
4249}
4250EXPORT_SYMBOL(__ksize);
1/*
2 * linux/mm/slab.c
3 * Written by Mark Hemment, 1996/97.
4 * (markhe@nextd.demon.co.uk)
5 *
6 * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli
7 *
8 * Major cleanup, different bufctl logic, per-cpu arrays
9 * (c) 2000 Manfred Spraul
10 *
11 * Cleanup, make the head arrays unconditional, preparation for NUMA
12 * (c) 2002 Manfred Spraul
13 *
14 * An implementation of the Slab Allocator as described in outline in;
15 * UNIX Internals: The New Frontiers by Uresh Vahalia
16 * Pub: Prentice Hall ISBN 0-13-101908-2
17 * or with a little more detail in;
18 * The Slab Allocator: An Object-Caching Kernel Memory Allocator
19 * Jeff Bonwick (Sun Microsystems).
20 * Presented at: USENIX Summer 1994 Technical Conference
21 *
22 * The memory is organized in caches, one cache for each object type.
23 * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct)
24 * Each cache consists out of many slabs (they are small (usually one
25 * page long) and always contiguous), and each slab contains multiple
26 * initialized objects.
27 *
28 * This means, that your constructor is used only for newly allocated
29 * slabs and you must pass objects with the same initializations to
30 * kmem_cache_free.
31 *
32 * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM,
33 * normal). If you need a special memory type, then must create a new
34 * cache for that memory type.
35 *
36 * In order to reduce fragmentation, the slabs are sorted in 3 groups:
37 * full slabs with 0 free objects
38 * partial slabs
39 * empty slabs with no allocated objects
40 *
41 * If partial slabs exist, then new allocations come from these slabs,
42 * otherwise from empty slabs or new slabs are allocated.
43 *
44 * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache
45 * during kmem_cache_destroy(). The caller must prevent concurrent allocs.
46 *
47 * Each cache has a short per-cpu head array, most allocs
48 * and frees go into that array, and if that array overflows, then 1/2
49 * of the entries in the array are given back into the global cache.
50 * The head array is strictly LIFO and should improve the cache hit rates.
51 * On SMP, it additionally reduces the spinlock operations.
52 *
53 * The c_cpuarray may not be read with enabled local interrupts -
54 * it's changed with a smp_call_function().
55 *
56 * SMP synchronization:
57 * constructors and destructors are called without any locking.
58 * Several members in struct kmem_cache and struct slab never change, they
59 * are accessed without any locking.
60 * The per-cpu arrays are never accessed from the wrong cpu, no locking,
61 * and local interrupts are disabled so slab code is preempt-safe.
62 * The non-constant members are protected with a per-cache irq spinlock.
63 *
64 * Many thanks to Mark Hemment, who wrote another per-cpu slab patch
65 * in 2000 - many ideas in the current implementation are derived from
66 * his patch.
67 *
68 * Further notes from the original documentation:
69 *
70 * 11 April '97. Started multi-threading - markhe
71 * The global cache-chain is protected by the mutex 'slab_mutex'.
72 * The sem is only needed when accessing/extending the cache-chain, which
73 * can never happen inside an interrupt (kmem_cache_create(),
74 * kmem_cache_shrink() and kmem_cache_reap()).
75 *
76 * At present, each engine can be growing a cache. This should be blocked.
77 *
78 * 15 March 2005. NUMA slab allocator.
79 * Shai Fultheim <shai@scalex86.org>.
80 * Shobhit Dayal <shobhit@calsoftinc.com>
81 * Alok N Kataria <alokk@calsoftinc.com>
82 * Christoph Lameter <christoph@lameter.com>
83 *
84 * Modified the slab allocator to be node aware on NUMA systems.
85 * Each node has its own list of partial, free and full slabs.
86 * All object allocations for a node occur from node specific slab lists.
87 */
88
89#include <linux/__KEEPIDENTS__B.h>
90#include <linux/__KEEPIDENTS__C.h>
91#include <linux/__KEEPIDENTS__D.h>
92#include <linux/__KEEPIDENTS__E.h>
93#include <linux/__KEEPIDENTS__F.h>
94#include <linux/__KEEPIDENTS__G.h>
95#include <linux/__KEEPIDENTS__H.h>
96#include <linux/__KEEPIDENTS__I.h>
97#include <linux/__KEEPIDENTS__J.h>
98#include <linux/proc_fs.h>
99#include <linux/__KEEPIDENTS__BA.h>
100#include <linux/__KEEPIDENTS__BB.h>
101#include <linux/__KEEPIDENTS__BC.h>
102#include <linux/cpu.h>
103#include <linux/__KEEPIDENTS__BD.h>
104#include <linux/__KEEPIDENTS__BE.h>
105#include <linux/rcupdate.h>
106#include <linux/__KEEPIDENTS__BF.h>
107#include <linux/__KEEPIDENTS__BG.h>
108#include <linux/__KEEPIDENTS__BH.h>
109#include <linux/kmemleak.h>
110#include <linux/__KEEPIDENTS__BI.h>
111#include <linux/__KEEPIDENTS__BJ.h>
112#include <linux/__KEEPIDENTS__CA-__KEEPIDENTS__CB.h>
113#include <linux/__KEEPIDENTS__CC.h>
114#include <linux/reciprocal_div.h>
115#include <linux/debugobjects.h>
116#include <linux/kmemcheck.h>
117#include <linux/__KEEPIDENTS__CD.h>
118#include <linux/__KEEPIDENTS__CE.h>
119
120#include <net/__KEEPIDENTS__CF.h>
121
122#include <asm/cacheflush.h>
123#include <asm/tlbflush.h>
124#include <asm/page.h>
125
126#include <trace/events/kmem.h>
127
128#include "internal.h"
129
130#include "slab.h"
131
132/*
133 * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON.
134 * 0 for faster, smaller code (especially in the critical paths).
135 *
136 * STATS - 1 to collect stats for /proc/slabinfo.
137 * 0 for faster, smaller code (especially in the critical paths).
138 *
139 * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible)
140 */
141
142#ifdef CONFIG_DEBUG_SLAB
143#define DEBUG 1
144#define STATS 1
145#define FORCED_DEBUG 1
146#else
147#define DEBUG 0
148#define STATS 0
149#define FORCED_DEBUG 0
150#endif
151
152/* Shouldn't this be in a header file somewhere? */
153#define BYTES_PER_WORD sizeof(void *)
154#define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long))
155
156#ifndef ARCH_KMALLOC_FLAGS
157#define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN
158#endif
159
160#define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \
161 <= SLAB_OBJ_MIN_SIZE) ? 1 : 0)
162
163#if FREELIST_BYTE_INDEX
164typedef unsigned char freelist_idx_t;
165#else
166typedef unsigned short freelist_idx_t;
167#endif
168
169#define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1)
170
171/*
172 * struct array_cache
173 *
174 * Purpose:
175 * - LIFO ordering, to hand out cache-warm objects from _alloc
176 * - reduce the number of linked list operations
177 * - reduce spinlock operations
178 *
179 * The limit is stored in the per-cpu structure to reduce the data cache
180 * footprint.
181 *
182 */
183struct array_cache {
184 unsigned int avail;
185 unsigned int limit;
186 unsigned int batchcount;
187 unsigned int touched;
188 void *entry[]; /*
189 * Must have this definition in here for the proper
190 * alignment of array_cache. Also simplifies accessing
191 * the entries.
192 */
193};
194
195struct alien_cache {
196 spinlock_t lock;
197 struct array_cache ac;
198};
199
200/*
201 * Need this for bootstrapping a per node allocator.
202 */
203#define NUM_INIT_LISTS (2 * MAX_NUMNODES)
204static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS];
205#define CACHE_CACHE 0
206#define SIZE_NODE (MAX_NUMNODES)
207
208static int drain_freelist(struct kmem_cache *cache,
209 struct kmem_cache_node *n, int tofree);
210static void free_block(struct kmem_cache *cachep, void **objpp, int len,
211 int node, struct list_head *list);
212static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list);
213static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp);
214static void cache_reap(struct work_struct *unused);
215
216static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
217 void **list);
218static inline void fixup_slab_list(struct kmem_cache *cachep,
219 struct kmem_cache_node *n, struct page *page,
220 void **list);
221static int slab_early_init = 1;
222
223#define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node))
224
225static void kmem_cache_node_init(struct kmem_cache_node *parent)
226{
227 INIT_LIST_HEAD(&parent->slabs_full);
228 INIT_LIST_HEAD(&parent->slabs_partial);
229 INIT_LIST_HEAD(&parent->slabs_free);
230 parent->total_slabs = 0;
231 parent->free_slabs = 0;
232 parent->shared = NULL;
233 parent->alien = NULL;
234 parent->colour_next = 0;
235 spin_lock_init(&parent->list_lock);
236 parent->free_objects = 0;
237 parent->free_touched = 0;
238}
239
240#define MAKE_LIST(cachep, listp, slab, nodeid) \
241 do { \
242 INIT_LIST_HEAD(listp); \
243 list_splice(&get_node(cachep, nodeid)->slab, listp); \
244 } while (0)
245
246#define MAKE_ALL_LISTS(cachep, ptr, nodeid) \
247 do { \
248 MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \
249 MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \
250 MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \
251 } while (0)
252
253#define CFLGS_OBJFREELIST_SLAB (0x40000000UL)
254#define CFLGS_OFF_SLAB (0x80000000UL)
255#define OBJFREELIST_SLAB(x) ((x)->flags & CFLGS_OBJFREELIST_SLAB)
256#define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB)
257
258#define BATCHREFILL_LIMIT 16
259/*
260 * Optimization question: fewer reaps means less probability for unnessary
261 * cpucache drain/refill cycles.
262 *
263 * OTOH the cpuarrays can contain lots of objects,
264 * which could lock up otherwise freeable slabs.
265 */
266#define REAPTIMEOUT_AC (2*HZ)
267#define REAPTIMEOUT_NODE (4*HZ)
268
269#if STATS
270#define STATS_INC_ACTIVE(x) ((x)->num_active++)
271#define STATS_DEC_ACTIVE(x) ((x)->num_active--)
272#define STATS_INC_ALLOCED(x) ((x)->num_allocations++)
273#define STATS_INC_GROWN(x) ((x)->grown++)
274#define STATS_ADD_REAPED(x,y) ((x)->reaped += (y))
275#define STATS_SET_HIGH(x) \
276 do { \
277 if ((x)->num_active > (x)->high_mark) \
278 (x)->high_mark = (x)->num_active; \
279 } while (0)
280#define STATS_INC_ERR(x) ((x)->errors++)
281#define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++)
282#define STATS_INC_NODEFREES(x) ((x)->node_frees++)
283#define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++)
284#define STATS_SET_FREEABLE(x, i) \
285 do { \
286 if ((x)->max_freeable < i) \
287 (x)->max_freeable = i; \
288 } while (0)
289#define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit)
290#define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss)
291#define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit)
292#define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss)
293#else
294#define STATS_INC_ACTIVE(x) do { } while (0)
295#define STATS_DEC_ACTIVE(x) do { } while (0)
296#define STATS_INC_ALLOCED(x) do { } while (0)
297#define STATS_INC_GROWN(x) do { } while (0)
298#define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0)
299#define STATS_SET_HIGH(x) do { } while (0)
300#define STATS_INC_ERR(x) do { } while (0)
301#define STATS_INC_NODEALLOCS(x) do { } while (0)
302#define STATS_INC_NODEFREES(x) do { } while (0)
303#define STATS_INC_ACOVERFLOW(x) do { } while (0)
304#define STATS_SET_FREEABLE(x, i) do { } while (0)
305#define STATS_INC_ALLOCHIT(x) do { } while (0)
306#define STATS_INC_ALLOCMISS(x) do { } while (0)
307#define STATS_INC_FREEHIT(x) do { } while (0)
308#define STATS_INC_FREEMISS(x) do { } while (0)
309#endif
310
311#if DEBUG
312
313/*
314 * memory layout of objects:
315 * 0 : objp
316 * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that
317 * the end of an object is aligned with the end of the real
318 * allocation. Catches writes behind the end of the allocation.
319 * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1:
320 * redzone word.
321 * cachep->obj_offset: The real object.
322 * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long]
323 * cachep->size - 1* BYTES_PER_WORD: last caller address
324 * [BYTES_PER_WORD long]
325 */
326static int obj_offset(struct kmem_cache *cachep)
327{
328 return cachep->obj_offset;
329}
330
331static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp)
332{
333 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
334 return (unsigned long long*) (objp + obj_offset(cachep) -
335 sizeof(unsigned long long));
336}
337
338static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp)
339{
340 BUG_ON(!(cachep->flags & SLAB_RED_ZONE));
341 if (cachep->flags & SLAB_STORE_USER)
342 return (unsigned long long *)(objp + cachep->size -
343 sizeof(unsigned long long) -
344 REDZONE_ALIGN);
345 return (unsigned long long *) (objp + cachep->size -
346 sizeof(unsigned long long));
347}
348
349static void **dbg_userword(struct kmem_cache *cachep, void *objp)
350{
351 BUG_ON(!(cachep->flags & SLAB_STORE_USER));
352 return (void **)(objp + cachep->size - BYTES_PER_WORD);
353}
354
355#else
356
357#define obj_offset(x) 0
358#define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
359#define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;})
360#define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;})
361
362#endif
363
364#ifdef CONFIG_DEBUG_SLAB_LEAK
365
366static inline bool is_store_user_clean(struct kmem_cache *cachep)
367{
368 return atomic_read(&cachep->store_user_clean) == 1;
369}
370
371static inline void set_store_user_clean(struct kmem_cache *cachep)
372{
373 atomic_set(&cachep->store_user_clean, 1);
374}
375
376static inline void set_store_user_dirty(struct kmem_cache *cachep)
377{
378 if (is_store_user_clean(cachep))
379 atomic_set(&cachep->store_user_clean, 0);
380}
381
382#else
383static inline void set_store_user_dirty(struct kmem_cache *cachep) {}
384
385#endif
386
387/*
388 * Do not go above this order unless 0 objects fit into the slab or
389 * overridden on the command line.
390 */
391#define SLAB_MAX_ORDER_HI 1
392#define SLAB_MAX_ORDER_LO 0
393static int slab_max_order = SLAB_MAX_ORDER_LO;
394static bool slab_max_order_set __initdata;
395
396static inline struct kmem_cache *virt_to_cache(const void *obj)
397{
398 struct page *page = virt_to_head_page(obj);
399 return page->slab_cache;
400}
401
402static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
403 unsigned int idx)
404{
405 return page->s_mem + cache->size * idx;
406}
407
408/*
409 * We want to avoid an expensive divide : (offset / cache->size)
410 * Using the fact that size is a constant for a particular cache,
411 * we can replace (offset / cache->size) by
412 * reciprocal_divide(offset, cache->reciprocal_buffer_size)
413 */
414static inline unsigned int obj_to_index(const struct kmem_cache *cache,
415 const struct page *page, void *obj)
416{
417 u32 offset = (obj - page->s_mem);
418 return reciprocal_divide(offset, cache->reciprocal_buffer_size);
419}
420
421#define BOOT_CPUCACHE_ENTRIES 1
422/* internal cache of cache description objs */
423static struct kmem_cache kmem_cache_boot = {
424 .batchcount = 1,
425 .limit = BOOT_CPUCACHE_ENTRIES,
426 .shared = 1,
427 .size = sizeof(struct kmem_cache),
428 .name = "kmem_cache",
429};
430
431static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);
432
433static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
434{
435 return this_cpu_ptr(cachep->cpu_cache);
436}
437
438/*
439 * Calculate the number of objects and left-over bytes for a given buffer size.
440 */
441static unsigned int cache_estimate(unsigned long gfporder, size_t buffer_size,
442 unsigned long flags, size_t *left_over)
443{
444 unsigned int num;
445 size_t slab_size = PAGE_SIZE << gfporder;
446
447 /*
448 * The slab management structure can be either off the slab or
449 * on it. For the latter case, the memory allocated for a
450 * slab is used for:
451 *
452 * - @buffer_size bytes for each object
453 * - One freelist_idx_t for each object
454 *
455 * We don't need to consider alignment of freelist because
456 * freelist will be at the end of slab page. The objects will be
457 * at the correct alignment.
458 *
459 * If the slab management structure is off the slab, then the
460 * alignment will already be calculated into the size. Because
461 * the slabs are all pages aligned, the objects will be at the
462 * correct alignment when allocated.
463 */
464 if (flags & (CFLGS_OBJFREELIST_SLAB | CFLGS_OFF_SLAB)) {
465 num = slab_size / buffer_size;
466 *left_over = slab_size % buffer_size;
467 } else {
468 num = slab_size / (buffer_size + sizeof(freelist_idx_t));
469 *left_over = slab_size %
470 (buffer_size + sizeof(freelist_idx_t));
471 }
472
473 return num;
474}
475
476#if DEBUG
477#define slab_error(cachep, msg) __slab_error(__func__, cachep, msg)
478
479static void __slab_error(const char *function, struct kmem_cache *cachep,
480 char *msg)
481{
482 pr_err("slab error in %s(): cache `%s': %s\n",
483 function, cachep->name, msg);
484 dump_stack();
485 add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
486}
487#endif
488
489/*
490 * By default on NUMA we use alien caches to stage the freeing of
491 * objects allocated from other nodes. This causes massive memory
492 * inefficiencies when using fake NUMA setup to split memory into a
493 * large number of small nodes, so it can be disabled on the command
494 * line
495 */
496
497static int use_alien_caches __read_mostly = 1;
498static int __init noaliencache_setup(char *s)
499{
500 use_alien_caches = 0;
501 return 1;
502}
503__setup("noaliencache", noaliencache_setup);
504
505static int __init slab_max_order_setup(char *str)
506{
507 get_option(&str, &slab_max_order);
508 slab_max_order = slab_max_order < 0 ? 0 :
509 min(slab_max_order, MAX_ORDER - 1);
510 slab_max_order_set = true;
511
512 return 1;
513}
514__setup("slab_max_order=", slab_max_order_setup);
515
516#ifdef CONFIG_NUMA
517/*
518 * Special reaping functions for NUMA systems called from cache_reap().
519 * These take care of doing round robin flushing of alien caches (containing
520 * objects freed on different nodes from which they were allocated) and the
521 * flushing of remote pcps by calling drain_node_pages.
522 */
523static DEFINE_PER_CPU(unsigned long, slab_reap_node);
524
525static void init_reap_node(int cpu)
526{
527 per_cpu(slab_reap_node, cpu) = next_node_in(cpu_to_mem(cpu),
528 node_online_map);
529}
530
531static void next_reap_node(void)
532{
533 int node = __this_cpu_read(slab_reap_node);
534
535 node = next_node_in(node, node_online_map);
536 __this_cpu_write(slab_reap_node, node);
537}
538
539#else
540#define init_reap_node(cpu) do { } while (0)
541#define next_reap_node(void) do { } while (0)
542#endif
543
544/*
545 * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz
546 * via the workqueue/eventd.
547 * Add the CPU number into the expiration time to minimize the possibility of
548 * the CPUs getting into lockstep and contending for the global cache chain
549 * lock.
550 */
551static void start_cpu_timer(int cpu)
552{
553 struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu);
554
555 if (reap_work->work.func == NULL) {
556 init_reap_node(cpu);
557 INIT_DEFERRABLE_WORK(reap_work, cache_reap);
558 schedule_delayed_work_on(cpu, reap_work,
559 __round_jiffies_relative(HZ, cpu));
560 }
561}
562
563static void init_arraycache(struct array_cache *ac, int limit, int batch)
564{
565 /*
566 * The array_cache structures contain pointers to free object.
567 * However, when such objects are allocated or transferred to another
568 * cache the pointers are not cleared and they could be counted as
569 * valid references during a kmemleak scan. Therefore, kmemleak must
570 * not scan such objects.
571 */
572 kmemleak_no_scan(ac);
573 if (ac) {
574 ac->avail = 0;
575 ac->limit = limit;
576 ac->batchcount = batch;
577 ac->touched = 0;
578 }
579}
580
581static struct array_cache *alloc_arraycache(int node, int entries,
582 int batchcount, gfp_t gfp)
583{
584 size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache);
585 struct array_cache *ac = NULL;
586
587 ac = kmalloc_node(memsize, gfp, node);
588 init_arraycache(ac, entries, batchcount);
589 return ac;
590}
591
592static noinline void cache_free_pfmemalloc(struct kmem_cache *cachep,
593 struct page *page, void *objp)
594{
595 struct kmem_cache_node *n;
596 int page_node;
597 LIST_HEAD(list);
598
599 page_node = page_to_nid(page);
600 n = get_node(cachep, page_node);
601
602 spin_lock(&n->list_lock);
603 free_block(cachep, &objp, 1, page_node, &list);
604 spin_unlock(&n->list_lock);
605
606 slabs_destroy(cachep, &list);
607}
608
609/*
610 * Transfer objects in one arraycache to another.
611 * Locking must be handled by the caller.
612 *
613 * Return the number of entries transferred.
614 */
615static int transfer_objects(struct array_cache *to,
616 struct array_cache *from, unsigned int max)
617{
618 /* Figure out how many entries to transfer */
619 int nr = min3(from->avail, max, to->limit - to->avail);
620
621 if (!nr)
622 return 0;
623
624 memcpy(to->entry + to->avail, from->entry + from->avail -nr,
625 sizeof(void *) *nr);
626
627 from->avail -= nr;
628 to->avail += nr;
629 return nr;
630}
631
632#ifndef CONFIG_NUMA
633
634#define drain_alien_cache(cachep, alien) do { } while (0)
635#define reap_alien(cachep, n) do { } while (0)
636
637static inline struct alien_cache **alloc_alien_cache(int node,
638 int limit, gfp_t gfp)
639{
640 return NULL;
641}
642
643static inline void free_alien_cache(struct alien_cache **ac_ptr)
644{
645}
646
647static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
648{
649 return 0;
650}
651
652static inline void *alternate_node_alloc(struct kmem_cache *cachep,
653 gfp_t flags)
654{
655 return NULL;
656}
657
658static inline void *____cache_alloc_node(struct kmem_cache *cachep,
659 gfp_t flags, int nodeid)
660{
661 return NULL;
662}
663
664static inline gfp_t gfp_exact_node(gfp_t flags)
665{
666 return flags & ~__GFP_NOFAIL;
667}
668
669#else /* CONFIG_NUMA */
670
671static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int);
672static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
673
674static struct alien_cache *__alloc_alien_cache(int node, int entries,
675 int batch, gfp_t gfp)
676{
677 size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache);
678 struct alien_cache *alc = NULL;
679
680 alc = kmalloc_node(memsize, gfp, node);
681 init_arraycache(&alc->ac, entries, batch);
682 spin_lock_init(&alc->lock);
683 return alc;
684}
685
686static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
687{
688 struct alien_cache **alc_ptr;
689 size_t memsize = sizeof(void *) * nr_node_ids;
690 int i;
691
692 if (limit > 1)
693 limit = 12;
694 alc_ptr = kzalloc_node(memsize, gfp, node);
695 if (!alc_ptr)
696 return NULL;
697
698 for_each_node(i) {
699 if (i == node || !node_online(i))
700 continue;
701 alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp);
702 if (!alc_ptr[i]) {
703 for (i--; i >= 0; i--)
704 kfree(alc_ptr[i]);
705 kfree(alc_ptr);
706 return NULL;
707 }
708 }
709 return alc_ptr;
710}
711
712static void free_alien_cache(struct alien_cache **alc_ptr)
713{
714 int i;
715
716 if (!alc_ptr)
717 return;
718 for_each_node(i)
719 kfree(alc_ptr[i]);
720 kfree(alc_ptr);
721}
722
723static void __drain_alien_cache(struct kmem_cache *cachep,
724 struct array_cache *ac, int node,
725 struct list_head *list)
726{
727 struct kmem_cache_node *n = get_node(cachep, node);
728
729 if (ac->avail) {
730 spin_lock(&n->list_lock);
731 /*
732 * Stuff objects into the remote nodes shared array first.
733 * That way we could avoid the overhead of putting the objects
734 * into the free lists and getting them back later.
735 */
736 if (n->shared)
737 transfer_objects(n->shared, ac, ac->limit);
738
739 free_block(cachep, ac->entry, ac->avail, node, list);
740 ac->avail = 0;
741 spin_unlock(&n->list_lock);
742 }
743}
744
745/*
746 * Called from cache_reap() to regularly drain alien caches round robin.
747 */
748static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n)
749{
750 int node = __this_cpu_read(slab_reap_node);
751
752 if (n->alien) {
753 struct alien_cache *alc = n->alien[node];
754 struct array_cache *ac;
755
756 if (alc) {
757 ac = &alc->ac;
758 if (ac->avail && spin_trylock_irq(&alc->lock)) {
759 LIST_HEAD(list);
760
761 __drain_alien_cache(cachep, ac, node, &list);
762 spin_unlock_irq(&alc->lock);
763 slabs_destroy(cachep, &list);
764 }
765 }
766 }
767}
768
769static void drain_alien_cache(struct kmem_cache *cachep,
770 struct alien_cache **alien)
771{
772 int i = 0;
773 struct alien_cache *alc;
774 struct array_cache *ac;
775 unsigned long flags;
776
777 for_each_online_node(i) {
778 alc = alien[i];
779 if (alc) {
780 LIST_HEAD(list);
781
782 ac = &alc->ac;
783 spin_lock_irqsave(&alc->lock, flags);
784 __drain_alien_cache(cachep, ac, i, &list);
785 spin_unlock_irqrestore(&alc->lock, flags);
786 slabs_destroy(cachep, &list);
787 }
788 }
789}
790
791static int __cache_free_alien(struct kmem_cache *cachep, void *objp,
792 int node, int page_node)
793{
794 struct kmem_cache_node *n;
795 struct alien_cache *alien = NULL;
796 struct array_cache *ac;
797 LIST_HEAD(list);
798
799 n = get_node(cachep, node);
800 STATS_INC_NODEFREES(cachep);
801 if (n->alien && n->alien[page_node]) {
802 alien = n->alien[page_node];
803 ac = &alien->ac;
804 spin_lock(&alien->lock);
805 if (unlikely(ac->avail == ac->limit)) {
806 STATS_INC_ACOVERFLOW(cachep);
807 __drain_alien_cache(cachep, ac, page_node, &list);
808 }
809 ac->entry[ac->avail++] = objp;
810 spin_unlock(&alien->lock);
811 slabs_destroy(cachep, &list);
812 } else {
813 n = get_node(cachep, page_node);
814 spin_lock(&n->list_lock);
815 free_block(cachep, &objp, 1, page_node, &list);
816 spin_unlock(&n->list_lock);
817 slabs_destroy(cachep, &list);
818 }
819 return 1;
820}
821
822static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
823{
824 int page_node = page_to_nid(virt_to_page(objp));
825 int node = numa_mem_id();
826 /*
827 * Make sure we are not freeing a object from another node to the array
828 * cache on this cpu.
829 */
830 if (likely(node == page_node))
831 return 0;
832
833 return __cache_free_alien(cachep, objp, node, page_node);
834}
835
836/*
837 * Construct gfp mask to allocate from a specific node but do not reclaim or
838 * warn about failures.
839 */
840static inline gfp_t gfp_exact_node(gfp_t flags)
841{
842 return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~(__GFP_RECLAIM|__GFP_NOFAIL);
843}
844#endif
845
846static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp)
847{
848 struct kmem_cache_node *n;
849
850 /*
851 * Set up the kmem_cache_node for cpu before we can
852 * begin anything. Make sure some other cpu on this
853 * node has not already allocated this
854 */
855 n = get_node(cachep, node);
856 if (n) {
857 spin_lock_irq(&n->list_lock);
858 n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount +
859 cachep->num;
860 spin_unlock_irq(&n->list_lock);
861
862 return 0;
863 }
864
865 n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node);
866 if (!n)
867 return -ENOMEM;
868
869 kmem_cache_node_init(n);
870 n->next_reap = jiffies + REAPTIMEOUT_NODE +
871 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
872
873 n->free_limit =
874 (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num;
875
876 /*
877 * The kmem_cache_nodes don't come and go as CPUs
878 * come and go. slab_mutex is sufficient
879 * protection here.
880 */
881 cachep->node[node] = n;
882
883 return 0;
884}
885
886#if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP)
887/*
888 * Allocates and initializes node for a node on each slab cache, used for
889 * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node
890 * will be allocated off-node since memory is not yet online for the new node.
891 * When hotplugging memory or a cpu, existing node are not replaced if
892 * already in use.
893 *
894 * Must hold slab_mutex.
895 */
896static int init_cache_node_node(int node)
897{
898 int ret;
899 struct kmem_cache *cachep;
900
901 list_for_each_entry(cachep, &slab_caches, list) {
902 ret = init_cache_node(cachep, node, GFP_KERNEL);
903 if (ret)
904 return ret;
905 }
906
907 return 0;
908}
909#endif
910
911static int setup_kmem_cache_node(struct kmem_cache *cachep,
912 int node, gfp_t gfp, bool force_change)
913{
914 int ret = -ENOMEM;
915 struct kmem_cache_node *n;
916 struct array_cache *old_shared = NULL;
917 struct array_cache *new_shared = NULL;
918 struct alien_cache **new_alien = NULL;
919 LIST_HEAD(list);
920
921 if (use_alien_caches) {
922 new_alien = alloc_alien_cache(node, cachep->limit, gfp);
923 if (!new_alien)
924 goto fail;
925 }
926
927 if (cachep->shared) {
928 new_shared = alloc_arraycache(node,
929 cachep->shared * cachep->batchcount, 0xbaadf00d, gfp);
930 if (!new_shared)
931 goto fail;
932 }
933
934 ret = init_cache_node(cachep, node, gfp);
935 if (ret)
936 goto fail;
937
938 n = get_node(cachep, node);
939 spin_lock_irq(&n->list_lock);
940 if (n->shared && force_change) {
941 free_block(cachep, n->shared->entry,
942 n->shared->avail, node, &list);
943 n->shared->avail = 0;
944 }
945
946 if (!n->shared || force_change) {
947 old_shared = n->shared;
948 n->shared = new_shared;
949 new_shared = NULL;
950 }
951
952 if (!n->alien) {
953 n->alien = new_alien;
954 new_alien = NULL;
955 }
956
957 spin_unlock_irq(&n->list_lock);
958 slabs_destroy(cachep, &list);
959
960 /*
961 * To protect lockless access to n->shared during irq disabled context.
962 * If n->shared isn't NULL in irq disabled context, accessing to it is
963 * guaranteed to be valid until irq is re-enabled, because it will be
964 * freed after synchronize_sched().
965 */
966 if (old_shared && force_change)
967 synchronize_sched();
968
969fail:
970 kfree(old_shared);
971 kfree(new_shared);
972 free_alien_cache(new_alien);
973
974 return ret;
975}
976
977#ifdef CONFIG_SMP
978
979static void cpuup_canceled(long cpu)
980{
981 struct kmem_cache *cachep;
982 struct kmem_cache_node *n = NULL;
983 int node = cpu_to_mem(cpu);
984 const struct cpumask *mask = cpumask_of_node(node);
985
986 list_for_each_entry(cachep, &slab_caches, list) {
987 struct array_cache *nc;
988 struct array_cache *shared;
989 struct alien_cache **alien;
990 LIST_HEAD(list);
991
992 n = get_node(cachep, node);
993 if (!n)
994 continue;
995
996 spin_lock_irq(&n->list_lock);
997
998 /* Free limit for this kmem_cache_node */
999 n->free_limit -= cachep->batchcount;
1000
1001 /* cpu is dead; no one can alloc from it. */
1002 nc = per_cpu_ptr(cachep->cpu_cache, cpu);
1003 if (nc) {
1004 free_block(cachep, nc->entry, nc->avail, node, &list);
1005 nc->avail = 0;
1006 }
1007
1008 if (!cpumask_empty(mask)) {
1009 spin_unlock_irq(&n->list_lock);
1010 goto free_slab;
1011 }
1012
1013 shared = n->shared;
1014 if (shared) {
1015 free_block(cachep, shared->entry,
1016 shared->avail, node, &list);
1017 n->shared = NULL;
1018 }
1019
1020 alien = n->alien;
1021 n->alien = NULL;
1022
1023 spin_unlock_irq(&n->list_lock);
1024
1025 kfree(shared);
1026 if (alien) {
1027 drain_alien_cache(cachep, alien);
1028 free_alien_cache(alien);
1029 }
1030
1031free_slab:
1032 slabs_destroy(cachep, &list);
1033 }
1034 /*
1035 * In the previous loop, all the objects were freed to
1036 * the respective cache's slabs, now we can go ahead and
1037 * shrink each nodelist to its limit.
1038 */
1039 list_for_each_entry(cachep, &slab_caches, list) {
1040 n = get_node(cachep, node);
1041 if (!n)
1042 continue;
1043 drain_freelist(cachep, n, INT_MAX);
1044 }
1045}
1046
1047static int cpuup_prepare(long cpu)
1048{
1049 struct kmem_cache *cachep;
1050 int node = cpu_to_mem(cpu);
1051 int err;
1052
1053 /*
1054 * We need to do this right in the beginning since
1055 * alloc_arraycache's are going to use this list.
1056 * kmalloc_node allows us to add the slab to the right
1057 * kmem_cache_node and not this cpu's kmem_cache_node
1058 */
1059 err = init_cache_node_node(node);
1060 if (err < 0)
1061 goto bad;
1062
1063 /*
1064 * Now we can go ahead with allocating the shared arrays and
1065 * array caches
1066 */
1067 list_for_each_entry(cachep, &slab_caches, list) {
1068 err = setup_kmem_cache_node(cachep, node, GFP_KERNEL, false);
1069 if (err)
1070 goto bad;
1071 }
1072
1073 return 0;
1074bad:
1075 cpuup_canceled(cpu);
1076 return -ENOMEM;
1077}
1078
1079int slab_prepare_cpu(unsigned int cpu)
1080{
1081 int err;
1082
1083 mutex_lock(&slab_mutex);
1084 err = cpuup_prepare(cpu);
1085 mutex_unlock(&slab_mutex);
1086 return err;
1087}
1088
1089/*
1090 * This is called for a failed online attempt and for a successful
1091 * offline.
1092 *
1093 * Even if all the cpus of a node are down, we don't free the
1094 * kmem_list3 of any cache. This to avoid a race between cpu_down, and
1095 * a kmalloc allocation from another cpu for memory from the node of
1096 * the cpu going down. The list3 structure is usually allocated from
1097 * kmem_cache_create() and gets destroyed at kmem_cache_destroy().
1098 */
1099int slab_dead_cpu(unsigned int cpu)
1100{
1101 mutex_lock(&slab_mutex);
1102 cpuup_canceled(cpu);
1103 mutex_unlock(&slab_mutex);
1104 return 0;
1105}
1106#endif
1107
1108static int slab_online_cpu(unsigned int cpu)
1109{
1110 start_cpu_timer(cpu);
1111 return 0;
1112}
1113
1114static int slab_offline_cpu(unsigned int cpu)
1115{
1116 /*
1117 * Shutdown cache reaper. Note that the slab_mutex is held so
1118 * that if cache_reap() is invoked it cannot do anything
1119 * expensive but will only modify reap_work and reschedule the
1120 * timer.
1121 */
1122 cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu));
1123 /* Now the cache_reaper is guaranteed to be not running. */
1124 per_cpu(slab_reap_work, cpu).work.func = NULL;
1125 return 0;
1126}
1127
1128#if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)
1129/*
1130 * Drains freelist for a node on each slab cache, used for memory hot-remove.
1131 * Returns -EBUSY if all objects cannot be drained so that the node is not
1132 * removed.
1133 *
1134 * Must hold slab_mutex.
1135 */
1136static int __meminit drain_cache_node_node(int node)
1137{
1138 struct kmem_cache *cachep;
1139 int ret = 0;
1140
1141 list_for_each_entry(cachep, &slab_caches, list) {
1142 struct kmem_cache_node *n;
1143
1144 n = get_node(cachep, node);
1145 if (!n)
1146 continue;
1147
1148 drain_freelist(cachep, n, INT_MAX);
1149
1150 if (!list_empty(&n->slabs_full) ||
1151 !list_empty(&n->slabs_partial)) {
1152 ret = -EBUSY;
1153 break;
1154 }
1155 }
1156 return ret;
1157}
1158
1159static int __meminit slab_memory_callback(struct notifier_block *self,
1160 unsigned long action, void *arg)
1161{
1162 struct memory_notify *mnb = arg;
1163 int ret = 0;
1164 int nid;
1165
1166 nid = mnb->status_change_nid;
1167 if (nid < 0)
1168 goto out;
1169
1170 switch (action) {
1171 case MEM_GOING_ONLINE:
1172 mutex_lock(&slab_mutex);
1173 ret = init_cache_node_node(nid);
1174 mutex_unlock(&slab_mutex);
1175 break;
1176 case MEM_GOING_OFFLINE:
1177 mutex_lock(&slab_mutex);
1178 ret = drain_cache_node_node(nid);
1179 mutex_unlock(&slab_mutex);
1180 break;
1181 case MEM_ONLINE:
1182 case MEM_OFFLINE:
1183 case MEM_CANCEL_ONLINE:
1184 case MEM_CANCEL_OFFLINE:
1185 break;
1186 }
1187out:
1188 return notifier_from_errno(ret);
1189}
1190#endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */
1191
1192/*
1193 * swap the static kmem_cache_node with kmalloced memory
1194 */
1195static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list,
1196 int nodeid)
1197{
1198 struct kmem_cache_node *ptr;
1199
1200 ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid);
1201 BUG_ON(!ptr);
1202
1203 memcpy(ptr, list, sizeof(struct kmem_cache_node));
1204 /*
1205 * Do not assume that spinlocks can be initialized via memcpy:
1206 */
1207 spin_lock_init(&ptr->list_lock);
1208
1209 MAKE_ALL_LISTS(cachep, ptr, nodeid);
1210 cachep->node[nodeid] = ptr;
1211}
1212
1213/*
1214 * For setting up all the kmem_cache_node for cache whose buffer_size is same as
1215 * size of kmem_cache_node.
1216 */
1217static void __init set_up_node(struct kmem_cache *cachep, int index)
1218{
1219 int node;
1220
1221 for_each_online_node(node) {
1222 cachep->node[node] = &init_kmem_cache_node[index + node];
1223 cachep->node[node]->next_reap = jiffies +
1224 REAPTIMEOUT_NODE +
1225 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
1226 }
1227}
1228
1229/*
1230 * Initialisation. Called after the page allocator have been initialised and
1231 * before smp_init().
1232 */
1233void __init kmem_cache_init(void)
1234{
1235 int i;
1236
1237 BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) <
1238 sizeof(struct rcu_head));
1239 kmem_cache = &kmem_cache_boot;
1240
1241 if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1)
1242 use_alien_caches = 0;
1243
1244 for (i = 0; i < NUM_INIT_LISTS; i++)
1245 kmem_cache_node_init(&init_kmem_cache_node[i]);
1246
1247 /*
1248 * Fragmentation resistance on low memory - only use bigger
1249 * page orders on machines with more than 32MB of memory if
1250 * not overridden on the command line.
1251 */
1252 if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT)
1253 slab_max_order = SLAB_MAX_ORDER_HI;
1254
1255 /* Bootstrap is tricky, because several objects are allocated
1256 * from caches that do not exist yet:
1257 * 1) initialize the kmem_cache cache: it contains the struct
1258 * kmem_cache structures of all caches, except kmem_cache itself:
1259 * kmem_cache is statically allocated.
1260 * Initially an __init data area is used for the head array and the
1261 * kmem_cache_node structures, it's replaced with a kmalloc allocated
1262 * array at the end of the bootstrap.
1263 * 2) Create the first kmalloc cache.
1264 * The struct kmem_cache for the new cache is allocated normally.
1265 * An __init data area is used for the head array.
1266 * 3) Create the remaining kmalloc caches, with minimally sized
1267 * head arrays.
1268 * 4) Replace the __init data head arrays for kmem_cache and the first
1269 * kmalloc cache with kmalloc allocated arrays.
1270 * 5) Replace the __init data for kmem_cache_node for kmem_cache and
1271 * the other cache's with kmalloc allocated memory.
1272 * 6) Resize the head arrays of the kmalloc caches to their final sizes.
1273 */
1274
1275 /* 1) create the kmem_cache */
1276
1277 /*
1278 * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids
1279 */
1280 create_boot_cache(kmem_cache, "kmem_cache",
1281 offsetof(struct kmem_cache, node) +
1282 nr_node_ids * sizeof(struct kmem_cache_node *),
1283 SLAB_HWCACHE_ALIGN);
1284 list_add(&kmem_cache->list, &slab_caches);
1285 slab_state = PARTIAL;
1286
1287 /*
1288 * Initialize the caches that provide memory for the kmem_cache_node
1289 * structures first. Without this, further allocations will bug.
1290 */
1291 kmalloc_caches[INDEX_NODE] = create_kmalloc_cache("kmalloc-node",
1292 kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS);
1293 slab_state = PARTIAL_NODE;
1294 setup_kmalloc_cache_index_table();
1295
1296 slab_early_init = 0;
1297
1298 /* 5) Replace the bootstrap kmem_cache_node */
1299 {
1300 int nid;
1301
1302 for_each_online_node(nid) {
1303 init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid);
1304
1305 init_list(kmalloc_caches[INDEX_NODE],
1306 &init_kmem_cache_node[SIZE_NODE + nid], nid);
1307 }
1308 }
1309
1310 create_kmalloc_caches(ARCH_KMALLOC_FLAGS);
1311}
1312
1313void __init kmem_cache_init_late(void)
1314{
1315 struct kmem_cache *cachep;
1316
1317 slab_state = UP;
1318
1319 /* 6) resize the head arrays to their final sizes */
1320 mutex_lock(&slab_mutex);
1321 list_for_each_entry(cachep, &slab_caches, list)
1322 if (enable_cpucache(cachep, GFP_NOWAIT))
1323 BUG();
1324 mutex_unlock(&slab_mutex);
1325
1326 /* Done! */
1327 slab_state = FULL;
1328
1329#ifdef CONFIG_NUMA
1330 /*
1331 * Register a memory hotplug callback that initializes and frees
1332 * node.
1333 */
1334 hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
1335#endif
1336
1337 /*
1338 * The reap timers are started later, with a module init call: That part
1339 * of the kernel is not yet operational.
1340 */
1341}
1342
1343static int __init cpucache_init(void)
1344{
1345 int ret;
1346
1347 /*
1348 * Register the timers that return unneeded pages to the page allocator
1349 */
1350 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SLAB online",
1351 slab_online_cpu, slab_offline_cpu);
1352 WARN_ON(ret < 0);
1353
1354 /* Done! */
1355 slab_state = FULL;
1356 return 0;
1357}
1358__initcall(cpucache_init);
1359
1360static noinline void
1361slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
1362{
1363#if DEBUG
1364 struct kmem_cache_node *n;
1365 unsigned long flags;
1366 int node;
1367 static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
1368 DEFAULT_RATELIMIT_BURST);
1369
1370 if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs))
1371 return;
1372
1373 pr_warn("SLAB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n",
1374 nodeid, gfpflags, &gfpflags);
1375 pr_warn(" cache: %s, object size: %d, order: %d\n",
1376 cachep->name, cachep->size, cachep->gfporder);
1377
1378 for_each_kmem_cache_node(cachep, node, n) {
1379 unsigned long total_slabs, free_slabs, free_objs;
1380
1381 spin_lock_irqsave(&n->list_lock, flags);
1382 total_slabs = n->total_slabs;
1383 free_slabs = n->free_slabs;
1384 free_objs = n->free_objects;
1385 spin_unlock_irqrestore(&n->list_lock, flags);
1386
1387 pr_warn(" node %d: slabs: %ld/%ld, objs: %ld/%ld\n",
1388 node, total_slabs - free_slabs, total_slabs,
1389 (total_slabs * cachep->num) - free_objs,
1390 total_slabs * cachep->num);
1391 }
1392#endif
1393}
1394
1395/*
1396 * Interface to system's page allocator. No need to hold the
1397 * kmem_cache_node ->list_lock.
1398 *
1399 * If we requested dmaable memory, we will get it. Even if we
1400 * did not request dmaable memory, we might get it, but that
1401 * would be relatively rare and ignorable.
1402 */
1403static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
1404 int nodeid)
1405{
1406 struct page *page;
1407 int nr_pages;
1408
1409 flags |= cachep->allocflags;
1410 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1411 flags |= __GFP_RECLAIMABLE;
1412
1413 page = __alloc_pages_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder);
1414 if (!page) {
1415 slab_out_of_memory(cachep, flags, nodeid);
1416 return NULL;
1417 }
1418
1419 if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
1420 __free_pages(page, cachep->gfporder);
1421 return NULL;
1422 }
1423
1424 nr_pages = (1 << cachep->gfporder);
1425 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1426 add_zone_page_state(page_zone(page),
1427 NR_SLAB_RECLAIMABLE, nr_pages);
1428 else
1429 add_zone_page_state(page_zone(page),
1430 NR_SLAB_UNRECLAIMABLE, nr_pages);
1431
1432 __SetPageSlab(page);
1433 /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
1434 if (sk_memalloc_socks() && page_is_pfmemalloc(page))
1435 SetPageSlabPfmemalloc(page);
1436
1437 if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
1438 kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid);
1439
1440 if (cachep->ctor)
1441 kmemcheck_mark_uninitialized_pages(page, nr_pages);
1442 else
1443 kmemcheck_mark_unallocated_pages(page, nr_pages);
1444 }
1445
1446 return page;
1447}
1448
1449/*
1450 * Interface to system's page release.
1451 */
1452static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
1453{
1454 int order = cachep->gfporder;
1455 unsigned long nr_freed = (1 << order);
1456
1457 kmemcheck_free_shadow(page, order);
1458
1459 if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
1460 sub_zone_page_state(page_zone(page),
1461 NR_SLAB_RECLAIMABLE, nr_freed);
1462 else
1463 sub_zone_page_state(page_zone(page),
1464 NR_SLAB_UNRECLAIMABLE, nr_freed);
1465
1466 BUG_ON(!PageSlab(page));
1467 __ClearPageSlabPfmemalloc(page);
1468 __ClearPageSlab(page);
1469 page_mapcount_reset(page);
1470 page->mapping = NULL;
1471
1472 if (current->reclaim_state)
1473 current->reclaim_state->reclaimed_slab += nr_freed;
1474 memcg_uncharge_slab(page, order, cachep);
1475 __free_pages(page, order);
1476}
1477
1478static void kmem_rcu_free(struct rcu_head *head)
1479{
1480 struct kmem_cache *cachep;
1481 struct page *page;
1482
1483 page = container_of(head, struct page, rcu_head);
1484 cachep = page->slab_cache;
1485
1486 kmem_freepages(cachep, page);
1487}
1488
1489#if DEBUG
1490static bool is_debug_pagealloc_cache(struct kmem_cache *cachep)
1491{
1492 if (debug_pagealloc_enabled() && OFF_SLAB(cachep) &&
1493 (cachep->size % PAGE_SIZE) == 0)
1494 return true;
1495
1496 return false;
1497}
1498
1499#ifdef CONFIG_DEBUG_PAGEALLOC
1500static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr,
1501 unsigned long caller)
1502{
1503 int size = cachep->object_size;
1504
1505 addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)];
1506
1507 if (size < 5 * sizeof(unsigned long))
1508 return;
1509
1510 *addr++ = 0x12345678;
1511 *addr++ = caller;
1512 *addr++ = smp_processor_id();
1513 size -= 3 * sizeof(unsigned long);
1514 {
1515 unsigned long *sptr = &caller;
1516 unsigned long svalue;
1517
1518 while (!kstack_end(sptr)) {
1519 svalue = *sptr++;
1520 if (kernel_text_address(svalue)) {
1521 *addr++ = svalue;
1522 size -= sizeof(unsigned long);
1523 if (size <= sizeof(unsigned long))
1524 break;
1525 }
1526 }
1527
1528 }
1529 *addr++ = 0x87654321;
1530}
1531
1532static void slab_kernel_map(struct kmem_cache *cachep, void *objp,
1533 int map, unsigned long caller)
1534{
1535 if (!is_debug_pagealloc_cache(cachep))
1536 return;
1537
1538 if (caller)
1539 store_stackinfo(cachep, objp, caller);
1540
1541 kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map);
1542}
1543
1544#else
1545static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp,
1546 int map, unsigned long caller) {}
1547
1548#endif
1549
1550static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val)
1551{
1552 int size = cachep->object_size;
1553 addr = &((char *)addr)[obj_offset(cachep)];
1554
1555 memset(addr, val, size);
1556 *(unsigned char *)(addr + size - 1) = POISON_END;
1557}
1558
1559static void dump_line(char *data, int offset, int limit)
1560{
1561 int i;
1562 unsigned char error = 0;
1563 int bad_count = 0;
1564
1565 pr_err("%03x: ", offset);
1566 for (i = 0; i < limit; i++) {
1567 if (data[offset + i] != POISON_FREE) {
1568 error = data[offset + i];
1569 bad_count++;
1570 }
1571 }
1572 print_hex_dump(KERN_CONT, "", 0, 16, 1,
1573 &data[offset], limit, 1);
1574
1575 if (bad_count == 1) {
1576 error ^= POISON_FREE;
1577 if (!(error & (error - 1))) {
1578 pr_err("Single bit error detected. Probably bad RAM.\n");
1579#ifdef CONFIG_X86
1580 pr_err("Run memtest86+ or a similar memory test tool.\n");
1581#else
1582 pr_err("Run a memory test tool.\n");
1583#endif
1584 }
1585 }
1586}
1587#endif
1588
1589#if DEBUG
1590
1591static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines)
1592{
1593 int i, size;
1594 char *realobj;
1595
1596 if (cachep->flags & SLAB_RED_ZONE) {
1597 pr_err("Redzone: 0x%llx/0x%llx\n",
1598 *dbg_redzone1(cachep, objp),
1599 *dbg_redzone2(cachep, objp));
1600 }
1601
1602 if (cachep->flags & SLAB_STORE_USER) {
1603 pr_err("Last user: [<%p>](%pSR)\n",
1604 *dbg_userword(cachep, objp),
1605 *dbg_userword(cachep, objp));
1606 }
1607 realobj = (char *)objp + obj_offset(cachep);
1608 size = cachep->object_size;
1609 for (i = 0; i < size && lines; i += 16, lines--) {
1610 int limit;
1611 limit = 16;
1612 if (i + limit > size)
1613 limit = size - i;
1614 dump_line(realobj, i, limit);
1615 }
1616}
1617
1618static void check_poison_obj(struct kmem_cache *cachep, void *objp)
1619{
1620 char *realobj;
1621 int size, i;
1622 int lines = 0;
1623
1624 if (is_debug_pagealloc_cache(cachep))
1625 return;
1626
1627 realobj = (char *)objp + obj_offset(cachep);
1628 size = cachep->object_size;
1629
1630 for (i = 0; i < size; i++) {
1631 char exp = POISON_FREE;
1632 if (i == size - 1)
1633 exp = POISON_END;
1634 if (realobj[i] != exp) {
1635 int limit;
1636 /* Mismatch ! */
1637 /* Print header */
1638 if (lines == 0) {
1639 pr_err("Slab corruption (%s): %s start=%p, len=%d\n",
1640 print_tainted(), cachep->name,
1641 realobj, size);
1642 print_objinfo(cachep, objp, 0);
1643 }
1644 /* Hexdump the affected line */
1645 i = (i / 16) * 16;
1646 limit = 16;
1647 if (i + limit > size)
1648 limit = size - i;
1649 dump_line(realobj, i, limit);
1650 i += 16;
1651 lines++;
1652 /* Limit to 5 lines */
1653 if (lines > 5)
1654 break;
1655 }
1656 }
1657 if (lines != 0) {
1658 /* Print some data about the neighboring objects, if they
1659 * exist:
1660 */
1661 struct page *page = virt_to_head_page(objp);
1662 unsigned int objnr;
1663
1664 objnr = obj_to_index(cachep, page, objp);
1665 if (objnr) {
1666 objp = index_to_obj(cachep, page, objnr - 1);
1667 realobj = (char *)objp + obj_offset(cachep);
1668 pr_err("Prev obj: start=%p, len=%d\n", realobj, size);
1669 print_objinfo(cachep, objp, 2);
1670 }
1671 if (objnr + 1 < cachep->num) {
1672 objp = index_to_obj(cachep, page, objnr + 1);
1673 realobj = (char *)objp + obj_offset(cachep);
1674 pr_err("Next obj: start=%p, len=%d\n", realobj, size);
1675 print_objinfo(cachep, objp, 2);
1676 }
1677 }
1678}
1679#endif
1680
1681#if DEBUG
1682static void slab_destroy_debugcheck(struct kmem_cache *cachep,
1683 struct page *page)
1684{
1685 int i;
1686
1687 if (OBJFREELIST_SLAB(cachep) && cachep->flags & SLAB_POISON) {
1688 poison_obj(cachep, page->freelist - obj_offset(cachep),
1689 POISON_FREE);
1690 }
1691
1692 for (i = 0; i < cachep->num; i++) {
1693 void *objp = index_to_obj(cachep, page, i);
1694
1695 if (cachep->flags & SLAB_POISON) {
1696 check_poison_obj(cachep, objp);
1697 slab_kernel_map(cachep, objp, 1, 0);
1698 }
1699 if (cachep->flags & SLAB_RED_ZONE) {
1700 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
1701 slab_error(cachep, "start of a freed object was overwritten");
1702 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
1703 slab_error(cachep, "end of a freed object was overwritten");
1704 }
1705 }
1706}
1707#else
1708static void slab_destroy_debugcheck(struct kmem_cache *cachep,
1709 struct page *page)
1710{
1711}
1712#endif
1713
1714/**
1715 * slab_destroy - destroy and release all objects in a slab
1716 * @cachep: cache pointer being destroyed
1717 * @page: page pointer being destroyed
1718 *
1719 * Destroy all the objs in a slab page, and release the mem back to the system.
1720 * Before calling the slab page must have been unlinked from the cache. The
1721 * kmem_cache_node ->list_lock is not held/needed.
1722 */
1723static void slab_destroy(struct kmem_cache *cachep, struct page *page)
1724{
1725 void *freelist;
1726
1727 freelist = page->freelist;
1728 slab_destroy_debugcheck(cachep, page);
1729 if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
1730 call_rcu(&page->rcu_head, kmem_rcu_free);
1731 else
1732 kmem_freepages(cachep, page);
1733
1734 /*
1735 * From now on, we don't use freelist
1736 * although actual page can be freed in rcu context
1737 */
1738 if (OFF_SLAB(cachep))
1739 kmem_cache_free(cachep->freelist_cache, freelist);
1740}
1741
1742static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list)
1743{
1744 struct page *page, *n;
1745
1746 list_for_each_entry_safe(page, n, list, lru) {
1747 list_del(&page->lru);
1748 slab_destroy(cachep, page);
1749 }
1750}
1751
1752/**
1753 * calculate_slab_order - calculate size (page order) of slabs
1754 * @cachep: pointer to the cache that is being created
1755 * @size: size of objects to be created in this cache.
1756 * @flags: slab allocation flags
1757 *
1758 * Also calculates the number of objects per slab.
1759 *
1760 * This could be made much more intelligent. For now, try to avoid using
1761 * high order pages for slabs. When the gfp() functions are more friendly
1762 * towards high-order requests, this should be changed.
1763 */
1764static size_t calculate_slab_order(struct kmem_cache *cachep,
1765 size_t size, unsigned long flags)
1766{
1767 size_t left_over = 0;
1768 int gfporder;
1769
1770 for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) {
1771 unsigned int num;
1772 size_t remainder;
1773
1774 num = cache_estimate(gfporder, size, flags, &remainder);
1775 if (!num)
1776 continue;
1777
1778 /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */
1779 if (num > SLAB_OBJ_MAX_NUM)
1780 break;
1781
1782 if (flags & CFLGS_OFF_SLAB) {
1783 struct kmem_cache *freelist_cache;
1784 size_t freelist_size;
1785
1786 freelist_size = num * sizeof(freelist_idx_t);
1787 freelist_cache = kmalloc_slab(freelist_size, 0u);
1788 if (!freelist_cache)
1789 continue;
1790
1791 /*
1792 * Needed to avoid possible looping condition
1793 * in cache_grow_begin()
1794 */
1795 if (OFF_SLAB(freelist_cache))
1796 continue;
1797
1798 /* check if off slab has enough benefit */
1799 if (freelist_cache->size > cachep->size / 2)
1800 continue;
1801 }
1802
1803 /* Found something acceptable - save it away */
1804 cachep->num = num;
1805 cachep->gfporder = gfporder;
1806 left_over = remainder;
1807
1808 /*
1809 * A VFS-reclaimable slab tends to have most allocations
1810 * as GFP_NOFS and we really don't want to have to be allocating
1811 * higher-order pages when we are unable to shrink dcache.
1812 */
1813 if (flags & SLAB_RECLAIM_ACCOUNT)
1814 break;
1815
1816 /*
1817 * Large number of objects is good, but very large slabs are
1818 * currently bad for the gfp()s.
1819 */
1820 if (gfporder >= slab_max_order)
1821 break;
1822
1823 /*
1824 * Acceptable internal fragmentation?
1825 */
1826 if (left_over * 8 <= (PAGE_SIZE << gfporder))
1827 break;
1828 }
1829 return left_over;
1830}
1831
1832static struct array_cache __percpu *alloc_kmem_cache_cpus(
1833 struct kmem_cache *cachep, int entries, int batchcount)
1834{
1835 int cpu;
1836 size_t size;
1837 struct array_cache __percpu *cpu_cache;
1838
1839 size = sizeof(void *) * entries + sizeof(struct array_cache);
1840 cpu_cache = __alloc_percpu(size, sizeof(void *));
1841
1842 if (!cpu_cache)
1843 return NULL;
1844
1845 for_each_possible_cpu(cpu) {
1846 init_arraycache(per_cpu_ptr(cpu_cache, cpu),
1847 entries, batchcount);
1848 }
1849
1850 return cpu_cache;
1851}
1852
1853static int __ref setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
1854{
1855 if (slab_state >= FULL)
1856 return enable_cpucache(cachep, gfp);
1857
1858 cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1);
1859 if (!cachep->cpu_cache)
1860 return 1;
1861
1862 if (slab_state == DOWN) {
1863 /* Creation of first cache (kmem_cache). */
1864 set_up_node(kmem_cache, CACHE_CACHE);
1865 } else if (slab_state == PARTIAL) {
1866 /* For kmem_cache_node */
1867 set_up_node(cachep, SIZE_NODE);
1868 } else {
1869 int node;
1870
1871 for_each_online_node(node) {
1872 cachep->node[node] = kmalloc_node(
1873 sizeof(struct kmem_cache_node), gfp, node);
1874 BUG_ON(!cachep->node[node]);
1875 kmem_cache_node_init(cachep->node[node]);
1876 }
1877 }
1878
1879 cachep->node[numa_mem_id()]->next_reap =
1880 jiffies + REAPTIMEOUT_NODE +
1881 ((unsigned long)cachep) % REAPTIMEOUT_NODE;
1882
1883 cpu_cache_get(cachep)->avail = 0;
1884 cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES;
1885 cpu_cache_get(cachep)->batchcount = 1;
1886 cpu_cache_get(cachep)->touched = 0;
1887 cachep->batchcount = 1;
1888 cachep->limit = BOOT_CPUCACHE_ENTRIES;
1889 return 0;
1890}
1891
1892unsigned long kmem_cache_flags(unsigned long object_size,
1893 unsigned long flags, const char *name,
1894 void (*ctor)(void *))
1895{
1896 return flags;
1897}
1898
1899struct kmem_cache *
1900__kmem_cache_alias(const char *name, size_t size, size_t align,
1901 unsigned long flags, void (*ctor)(void *))
1902{
1903 struct kmem_cache *cachep;
1904
1905 cachep = find_mergeable(size, align, flags, name, ctor);
1906 if (cachep) {
1907 cachep->refcount++;
1908
1909 /*
1910 * Adjust the object sizes so that we clear
1911 * the complete object on kzalloc.
1912 */
1913 cachep->object_size = max_t(int, cachep->object_size, size);
1914 }
1915 return cachep;
1916}
1917
1918static bool set_objfreelist_slab_cache(struct kmem_cache *cachep,
1919 size_t size, unsigned long flags)
1920{
1921 size_t left;
1922
1923 cachep->num = 0;
1924
1925 if (cachep->ctor || flags & SLAB_DESTROY_BY_RCU)
1926 return false;
1927
1928 left = calculate_slab_order(cachep, size,
1929 flags | CFLGS_OBJFREELIST_SLAB);
1930 if (!cachep->num)
1931 return false;
1932
1933 if (cachep->num * sizeof(freelist_idx_t) > cachep->object_size)
1934 return false;
1935
1936 cachep->colour = left / cachep->colour_off;
1937
1938 return true;
1939}
1940
1941static bool set_off_slab_cache(struct kmem_cache *cachep,
1942 size_t size, unsigned long flags)
1943{
1944 size_t left;
1945
1946 cachep->num = 0;
1947
1948 /*
1949 * Always use on-slab management when SLAB_NOLEAKTRACE
1950 * to avoid recursive calls into kmemleak.
1951 */
1952 if (flags & SLAB_NOLEAKTRACE)
1953 return false;
1954
1955 /*
1956 * Size is large, assume best to place the slab management obj
1957 * off-slab (should allow better packing of objs).
1958 */
1959 left = calculate_slab_order(cachep, size, flags | CFLGS_OFF_SLAB);
1960 if (!cachep->num)
1961 return false;
1962
1963 /*
1964 * If the slab has been placed off-slab, and we have enough space then
1965 * move it on-slab. This is at the expense of any extra colouring.
1966 */
1967 if (left >= cachep->num * sizeof(freelist_idx_t))
1968 return false;
1969
1970 cachep->colour = left / cachep->colour_off;
1971
1972 return true;
1973}
1974
1975static bool set_on_slab_cache(struct kmem_cache *cachep,
1976 size_t size, unsigned long flags)
1977{
1978 size_t left;
1979
1980 cachep->num = 0;
1981
1982 left = calculate_slab_order(cachep, size, flags);
1983 if (!cachep->num)
1984 return false;
1985
1986 cachep->colour = left / cachep->colour_off;
1987
1988 return true;
1989}
1990
1991/**
1992 * __kmem_cache_create - Create a cache.
1993 * @cachep: cache management descriptor
1994 * @flags: SLAB flags
1995 *
1996 * Returns a ptr to the cache on success, NULL on failure.
1997 * Cannot be called within a int, but can be interrupted.
1998 * The @ctor is run when new pages are allocated by the cache.
1999 *
2000 * The flags are
2001 *
2002 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
2003 * to catch references to uninitialised memory.
2004 *
2005 * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check
2006 * for buffer overruns.
2007 *
2008 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
2009 * cacheline. This can be beneficial if you're counting cycles as closely
2010 * as davem.
2011 */
2012int
2013__kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
2014{
2015 size_t ralign = BYTES_PER_WORD;
2016 gfp_t gfp;
2017 int err;
2018 size_t size = cachep->size;
2019
2020#if DEBUG
2021#if FORCED_DEBUG
2022 /*
2023 * Enable redzoning and last user accounting, except for caches with
2024 * large objects, if the increased size would increase the object size
2025 * above the next power of two: caches with object sizes just above a
2026 * power of two have a significant amount of internal fragmentation.
2027 */
2028 if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN +
2029 2 * sizeof(unsigned long long)))
2030 flags |= SLAB_RED_ZONE | SLAB_STORE_USER;
2031 if (!(flags & SLAB_DESTROY_BY_RCU))
2032 flags |= SLAB_POISON;
2033#endif
2034#endif
2035
2036 /*
2037 * Check that size is in terms of words. This is needed to avoid
2038 * unaligned accesses for some archs when redzoning is used, and makes
2039 * sure any on-slab bufctl's are also correctly aligned.
2040 */
2041 if (size & (BYTES_PER_WORD - 1)) {
2042 size += (BYTES_PER_WORD - 1);
2043 size &= ~(BYTES_PER_WORD - 1);
2044 }
2045
2046 if (flags & SLAB_RED_ZONE) {
2047 ralign = REDZONE_ALIGN;
2048 /* If redzoning, ensure that the second redzone is suitably
2049 * aligned, by adjusting the object size accordingly. */
2050 size += REDZONE_ALIGN - 1;
2051 size &= ~(REDZONE_ALIGN - 1);
2052 }
2053
2054 /* 3) caller mandated alignment */
2055 if (ralign < cachep->align) {
2056 ralign = cachep->align;
2057 }
2058 /* disable debug if necessary */
2059 if (ralign > __alignof__(unsigned long long))
2060 flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
2061 /*
2062 * 4) Store it.
2063 */
2064 cachep->align = ralign;
2065 cachep->colour_off = cache_line_size();
2066 /* Offset must be a multiple of the alignment. */
2067 if (cachep->colour_off < cachep->align)
2068 cachep->colour_off = cachep->align;
2069
2070 if (slab_is_available())
2071 gfp = GFP_KERNEL;
2072 else
2073 gfp = GFP_NOWAIT;
2074
2075#if DEBUG
2076
2077 /*
2078 * Both debugging options require word-alignment which is calculated
2079 * into align above.
2080 */
2081 if (flags & SLAB_RED_ZONE) {
2082 /* add space for red zone words */
2083 cachep->obj_offset += sizeof(unsigned long long);
2084 size += 2 * sizeof(unsigned long long);
2085 }
2086 if (flags & SLAB_STORE_USER) {
2087 /* user store requires one word storage behind the end of
2088 * the real object. But if the second red zone needs to be
2089 * aligned to 64 bits, we must allow that much space.
2090 */
2091 if (flags & SLAB_RED_ZONE)
2092 size += REDZONE_ALIGN;
2093 else
2094 size += BYTES_PER_WORD;
2095 }
2096#endif
2097
2098 kasan_cache_create(cachep, &size, &flags);
2099
2100 size = ALIGN(size, cachep->align);
2101 /*
2102 * We should restrict the number of objects in a slab to implement
2103 * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
2104 */
2105 if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
2106 size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
2107
2108#if DEBUG
2109 /*
2110 * To activate debug pagealloc, off-slab management is necessary
2111 * requirement. In early phase of initialization, small sized slab
2112 * doesn't get initialized so it would not be possible. So, we need
2113 * to check size >= 256. It guarantees that all necessary small
2114 * sized slab is initialized in current slab initialization sequence.
2115 */
2116 if (debug_pagealloc_enabled() && (flags & SLAB_POISON) &&
2117 size >= 256 && cachep->object_size > cache_line_size()) {
2118 if (size < PAGE_SIZE || size % PAGE_SIZE == 0) {
2119 size_t tmp_size = ALIGN(size, PAGE_SIZE);
2120
2121 if (set_off_slab_cache(cachep, tmp_size, flags)) {
2122 flags |= CFLGS_OFF_SLAB;
2123 cachep->obj_offset += tmp_size - size;
2124 size = tmp_size;
2125 goto done;
2126 }
2127 }
2128 }
2129#endif
2130
2131 if (set_objfreelist_slab_cache(cachep, size, flags)) {
2132 flags |= CFLGS_OBJFREELIST_SLAB;
2133 goto done;
2134 }
2135
2136 if (set_off_slab_cache(cachep, size, flags)) {
2137 flags |= CFLGS_OFF_SLAB;
2138 goto done;
2139 }
2140
2141 if (set_on_slab_cache(cachep, size, flags))
2142 goto done;
2143
2144 return -E2BIG;
2145
2146done:
2147 cachep->freelist_size = cachep->num * sizeof(freelist_idx_t);
2148 cachep->flags = flags;
2149 cachep->allocflags = __GFP_COMP;
2150 if (flags & SLAB_CACHE_DMA)
2151 cachep->allocflags |= GFP_DMA;
2152 cachep->size = size;
2153 cachep->reciprocal_buffer_size = reciprocal_value(size);
2154
2155#if DEBUG
2156 /*
2157 * If we're going to use the generic kernel_map_pages()
2158 * poisoning, then it's going to smash the contents of
2159 * the redzone and userword anyhow, so switch them off.
2160 */
2161 if (IS_ENABLED(CONFIG_PAGE_POISONING) &&
2162 (cachep->flags & SLAB_POISON) &&
2163 is_debug_pagealloc_cache(cachep))
2164 cachep->flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
2165#endif
2166
2167 if (OFF_SLAB(cachep)) {
2168 cachep->freelist_cache =
2169 kmalloc_slab(cachep->freelist_size, 0u);
2170 }
2171
2172 err = setup_cpu_cache(cachep, gfp);
2173 if (err) {
2174 __kmem_cache_release(cachep);
2175 return err;
2176 }
2177
2178 return 0;
2179}
2180
2181#if DEBUG
2182static void check_irq_off(void)
2183{
2184 BUG_ON(!irqs_disabled());
2185}
2186
2187static void check_irq_on(void)
2188{
2189 BUG_ON(irqs_disabled());
2190}
2191
2192static void check_mutex_acquired(void)
2193{
2194 BUG_ON(!mutex_is_locked(&slab_mutex));
2195}
2196
2197static void check_spinlock_acquired(struct kmem_cache *cachep)
2198{
2199#ifdef CONFIG_SMP
2200 check_irq_off();
2201 assert_spin_locked(&get_node(cachep, numa_mem_id())->list_lock);
2202#endif
2203}
2204
2205static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node)
2206{
2207#ifdef CONFIG_SMP
2208 check_irq_off();
2209 assert_spin_locked(&get_node(cachep, node)->list_lock);
2210#endif
2211}
2212
2213#else
2214#define check_irq_off() do { } while(0)
2215#define check_irq_on() do { } while(0)
2216#define check_mutex_acquired() do { } while(0)
2217#define check_spinlock_acquired(x) do { } while(0)
2218#define check_spinlock_acquired_node(x, y) do { } while(0)
2219#endif
2220
2221static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac,
2222 int node, bool free_all, struct list_head *list)
2223{
2224 int tofree;
2225
2226 if (!ac || !ac->avail)
2227 return;
2228
2229 tofree = free_all ? ac->avail : (ac->limit + 4) / 5;
2230 if (tofree > ac->avail)
2231 tofree = (ac->avail + 1) / 2;
2232
2233 free_block(cachep, ac->entry, tofree, node, list);
2234 ac->avail -= tofree;
2235 memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail);
2236}
2237
2238static void do_drain(void *arg)
2239{
2240 struct kmem_cache *cachep = arg;
2241 struct array_cache *ac;
2242 int node = numa_mem_id();
2243 struct kmem_cache_node *n;
2244 LIST_HEAD(list);
2245
2246 check_irq_off();
2247 ac = cpu_cache_get(cachep);
2248 n = get_node(cachep, node);
2249 spin_lock(&n->list_lock);
2250 free_block(cachep, ac->entry, ac->avail, node, &list);
2251 spin_unlock(&n->list_lock);
2252 slabs_destroy(cachep, &list);
2253 ac->avail = 0;
2254}
2255
2256static void drain_cpu_caches(struct kmem_cache *cachep)
2257{
2258 struct kmem_cache_node *n;
2259 int node;
2260 LIST_HEAD(list);
2261
2262 on_each_cpu(do_drain, cachep, 1);
2263 check_irq_on();
2264 for_each_kmem_cache_node(cachep, node, n)
2265 if (n->alien)
2266 drain_alien_cache(cachep, n->alien);
2267
2268 for_each_kmem_cache_node(cachep, node, n) {
2269 spin_lock_irq(&n->list_lock);
2270 drain_array_locked(cachep, n->shared, node, true, &list);
2271 spin_unlock_irq(&n->list_lock);
2272
2273 slabs_destroy(cachep, &list);
2274 }
2275}
2276
2277/*
2278 * Remove slabs from the list of free slabs.
2279 * Specify the number of slabs to drain in tofree.
2280 *
2281 * Returns the actual number of slabs released.
2282 */
2283static int drain_freelist(struct kmem_cache *cache,
2284 struct kmem_cache_node *n, int tofree)
2285{
2286 struct list_head *p;
2287 int nr_freed;
2288 struct page *page;
2289
2290 nr_freed = 0;
2291 while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
2292
2293 spin_lock_irq(&n->list_lock);
2294 p = n->slabs_free.prev;
2295 if (p == &n->slabs_free) {
2296 spin_unlock_irq(&n->list_lock);
2297 goto out;
2298 }
2299
2300 page = list_entry(p, struct page, lru);
2301 list_del(&page->lru);
2302 n->free_slabs--;
2303 n->total_slabs--;
2304 /*
2305 * Safe to drop the lock. The slab is no longer linked
2306 * to the cache.
2307 */
2308 n->free_objects -= cache->num;
2309 spin_unlock_irq(&n->list_lock);
2310 slab_destroy(cache, page);
2311 nr_freed++;
2312 }
2313out:
2314 return nr_freed;
2315}
2316
2317int __kmem_cache_shrink(struct kmem_cache *cachep)
2318{
2319 int ret = 0;
2320 int node;
2321 struct kmem_cache_node *n;
2322
2323 drain_cpu_caches(cachep);
2324
2325 check_irq_on();
2326 for_each_kmem_cache_node(cachep, node, n) {
2327 drain_freelist(cachep, n, INT_MAX);
2328
2329 ret += !list_empty(&n->slabs_full) ||
2330 !list_empty(&n->slabs_partial);
2331 }
2332 return (ret ? 1 : 0);
2333}
2334
2335int __kmem_cache_shutdown(struct kmem_cache *cachep)
2336{
2337 return __kmem_cache_shrink(cachep);
2338}
2339
2340void __kmem_cache_release(struct kmem_cache *cachep)
2341{
2342 int i;
2343 struct kmem_cache_node *n;
2344
2345 cache_random_seq_destroy(cachep);
2346
2347 free_percpu(cachep->cpu_cache);
2348
2349 /* NUMA: free the node structures */
2350 for_each_kmem_cache_node(cachep, i, n) {
2351 kfree(n->shared);
2352 free_alien_cache(n->alien);
2353 kfree(n);
2354 cachep->node[i] = NULL;
2355 }
2356}
2357
2358/*
2359 * Get the memory for a slab management obj.
2360 *
2361 * For a slab cache when the slab descriptor is off-slab, the
2362 * slab descriptor can't come from the same cache which is being created,
2363 * Because if it is the case, that means we defer the creation of
2364 * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point.
2365 * And we eventually call down to __kmem_cache_create(), which
2366 * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one.
2367 * This is a "chicken-and-egg" problem.
2368 *
2369 * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches,
2370 * which are all initialized during kmem_cache_init().
2371 */
2372static void *alloc_slabmgmt(struct kmem_cache *cachep,
2373 struct page *page, int colour_off,
2374 gfp_t local_flags, int nodeid)
2375{
2376 void *freelist;
2377 void *addr = page_address(page);
2378
2379 page->s_mem = addr + colour_off;
2380 page->active = 0;
2381
2382 if (OBJFREELIST_SLAB(cachep))
2383 freelist = NULL;
2384 else if (OFF_SLAB(cachep)) {
2385 /* Slab management obj is off-slab. */
2386 freelist = kmem_cache_alloc_node(cachep->freelist_cache,
2387 local_flags, nodeid);
2388 if (!freelist)
2389 return NULL;
2390 } else {
2391 /* We will use last bytes at the slab for freelist */
2392 freelist = addr + (PAGE_SIZE << cachep->gfporder) -
2393 cachep->freelist_size;
2394 }
2395
2396 return freelist;
2397}
2398
2399static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx)
2400{
2401 return ((freelist_idx_t *)page->freelist)[idx];
2402}
2403
2404static inline void set_free_obj(struct page *page,
2405 unsigned int idx, freelist_idx_t val)
2406{
2407 ((freelist_idx_t *)(page->freelist))[idx] = val;
2408}
2409
2410static void cache_init_objs_debug(struct kmem_cache *cachep, struct page *page)
2411{
2412#if DEBUG
2413 int i;
2414
2415 for (i = 0; i < cachep->num; i++) {
2416 void *objp = index_to_obj(cachep, page, i);
2417
2418 if (cachep->flags & SLAB_STORE_USER)
2419 *dbg_userword(cachep, objp) = NULL;
2420
2421 if (cachep->flags & SLAB_RED_ZONE) {
2422 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2423 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2424 }
2425 /*
2426 * Constructors are not allowed to allocate memory from the same
2427 * cache which they are a constructor for. Otherwise, deadlock.
2428 * They must also be threaded.
2429 */
2430 if (cachep->ctor && !(cachep->flags & SLAB_POISON)) {
2431 kasan_unpoison_object_data(cachep,
2432 objp + obj_offset(cachep));
2433 cachep->ctor(objp + obj_offset(cachep));
2434 kasan_poison_object_data(
2435 cachep, objp + obj_offset(cachep));
2436 }
2437
2438 if (cachep->flags & SLAB_RED_ZONE) {
2439 if (*dbg_redzone2(cachep, objp) != RED_INACTIVE)
2440 slab_error(cachep, "constructor overwrote the end of an object");
2441 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE)
2442 slab_error(cachep, "constructor overwrote the start of an object");
2443 }
2444 /* need to poison the objs? */
2445 if (cachep->flags & SLAB_POISON) {
2446 poison_obj(cachep, objp, POISON_FREE);
2447 slab_kernel_map(cachep, objp, 0, 0);
2448 }
2449 }
2450#endif
2451}
2452
2453#ifdef CONFIG_SLAB_FREELIST_RANDOM
2454/* Hold information during a freelist initialization */
2455union freelist_init_state {
2456 struct {
2457 unsigned int pos;
2458 unsigned int *list;
2459 unsigned int count;
2460 };
2461 struct rnd_state rnd_state;
2462};
2463
2464/*
2465 * Initialize the state based on the randomization methode available.
2466 * return true if the pre-computed list is available, false otherwize.
2467 */
2468static bool freelist_state_initialize(union freelist_init_state *state,
2469 struct kmem_cache *cachep,
2470 unsigned int count)
2471{
2472 bool ret;
2473 unsigned int rand;
2474
2475 /* Use best entropy available to define a random shift */
2476 rand = get_random_int();
2477
2478 /* Use a random state if the pre-computed list is not available */
2479 if (!cachep->random_seq) {
2480 prandom_seed_state(&state->rnd_state, rand);
2481 ret = false;
2482 } else {
2483 state->list = cachep->random_seq;
2484 state->count = count;
2485 state->pos = rand % count;
2486 ret = true;
2487 }
2488 return ret;
2489}
2490
2491/* Get the next entry on the list and randomize it using a random shift */
2492static freelist_idx_t next_random_slot(union freelist_init_state *state)
2493{
2494 if (state->pos >= state->count)
2495 state->pos = 0;
2496 return state->list[state->pos++];
2497}
2498
2499/* Swap two freelist entries */
2500static void swap_free_obj(struct page *page, unsigned int a, unsigned int b)
2501{
2502 swap(((freelist_idx_t *)page->freelist)[a],
2503 ((freelist_idx_t *)page->freelist)[b]);
2504}
2505
2506/*
2507 * Shuffle the freelist initialization state based on pre-computed lists.
2508 * return true if the list was successfully shuffled, false otherwise.
2509 */
2510static bool shuffle_freelist(struct kmem_cache *cachep, struct page *page)
2511{
2512 unsigned int objfreelist = 0, i, rand, count = cachep->num;
2513 union freelist_init_state state;
2514 bool precomputed;
2515
2516 if (count < 2)
2517 return false;
2518
2519 precomputed = freelist_state_initialize(&state, cachep, count);
2520
2521 /* Take a random entry as the objfreelist */
2522 if (OBJFREELIST_SLAB(cachep)) {
2523 if (!precomputed)
2524 objfreelist = count - 1;
2525 else
2526 objfreelist = next_random_slot(&state);
2527 page->freelist = index_to_obj(cachep, page, objfreelist) +
2528 obj_offset(cachep);
2529 count--;
2530 }
2531
2532 /*
2533 * On early boot, generate the list dynamically.
2534 * Later use a pre-computed list for speed.
2535 */
2536 if (!precomputed) {
2537 for (i = 0; i < count; i++)
2538 set_free_obj(page, i, i);
2539
2540 /* Fisher-Yates shuffle */
2541 for (i = count - 1; i > 0; i--) {
2542 rand = prandom_u32_state(&state.rnd_state);
2543 rand %= (i + 1);
2544 swap_free_obj(page, i, rand);
2545 }
2546 } else {
2547 for (i = 0; i < count; i++)
2548 set_free_obj(page, i, next_random_slot(&state));
2549 }
2550
2551 if (OBJFREELIST_SLAB(cachep))
2552 set_free_obj(page, cachep->num - 1, objfreelist);
2553
2554 return true;
2555}
2556#else
2557static inline bool shuffle_freelist(struct kmem_cache *cachep,
2558 struct page *page)
2559{
2560 return false;
2561}
2562#endif /* CONFIG_SLAB_FREELIST_RANDOM */
2563
2564static void cache_init_objs(struct kmem_cache *cachep,
2565 struct page *page)
2566{
2567 int i;
2568 void *objp;
2569 bool shuffled;
2570
2571 cache_init_objs_debug(cachep, page);
2572
2573 /* Try to randomize the freelist if enabled */
2574 shuffled = shuffle_freelist(cachep, page);
2575
2576 if (!shuffled && OBJFREELIST_SLAB(cachep)) {
2577 page->freelist = index_to_obj(cachep, page, cachep->num - 1) +
2578 obj_offset(cachep);
2579 }
2580
2581 for (i = 0; i < cachep->num; i++) {
2582 objp = index_to_obj(cachep, page, i);
2583 kasan_init_slab_obj(cachep, objp);
2584
2585 /* constructor could break poison info */
2586 if (DEBUG == 0 && cachep->ctor) {
2587 kasan_unpoison_object_data(cachep, objp);
2588 cachep->ctor(objp);
2589 kasan_poison_object_data(cachep, objp);
2590 }
2591
2592 if (!shuffled)
2593 set_free_obj(page, i, i);
2594 }
2595}
2596
2597static void *slab_get_obj(struct kmem_cache *cachep, struct page *page)
2598{
2599 void *objp;
2600
2601 objp = index_to_obj(cachep, page, get_free_obj(page, page->active));
2602 page->active++;
2603
2604#if DEBUG
2605 if (cachep->flags & SLAB_STORE_USER)
2606 set_store_user_dirty(cachep);
2607#endif
2608
2609 return objp;
2610}
2611
2612static void slab_put_obj(struct kmem_cache *cachep,
2613 struct page *page, void *objp)
2614{
2615 unsigned int objnr = obj_to_index(cachep, page, objp);
2616#if DEBUG
2617 unsigned int i;
2618
2619 /* Verify double free bug */
2620 for (i = page->active; i < cachep->num; i++) {
2621 if (get_free_obj(page, i) == objnr) {
2622 pr_err("slab: double free detected in cache '%s', objp %p\n",
2623 cachep->name, objp);
2624 BUG();
2625 }
2626 }
2627#endif
2628 page->active--;
2629 if (!page->freelist)
2630 page->freelist = objp + obj_offset(cachep);
2631
2632 set_free_obj(page, page->active, objnr);
2633}
2634
2635/*
2636 * Map pages beginning at addr to the given cache and slab. This is required
2637 * for the slab allocator to be able to lookup the cache and slab of a
2638 * virtual address for kfree, ksize, and slab debugging.
2639 */
2640static void slab_map_pages(struct kmem_cache *cache, struct page *page,
2641 void *freelist)
2642{
2643 page->slab_cache = cache;
2644 page->freelist = freelist;
2645}
2646
2647/*
2648 * Grow (by 1) the number of slabs within a cache. This is called by
2649 * kmem_cache_alloc() when there are no active objs left in a cache.
2650 */
2651static struct page *cache_grow_begin(struct kmem_cache *cachep,
2652 gfp_t flags, int nodeid)
2653{
2654 void *freelist;
2655 size_t offset;
2656 gfp_t local_flags;
2657 int page_node;
2658 struct kmem_cache_node *n;
2659 struct page *page;
2660
2661 /*
2662 * Be lazy and only check for valid flags here, keeping it out of the
2663 * critical path in kmem_cache_alloc().
2664 */
2665 if (unlikely(flags & GFP_SLAB_BUG_MASK)) {
2666 gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK;
2667 flags &= ~GFP_SLAB_BUG_MASK;
2668 pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n",
2669 invalid_mask, &invalid_mask, flags, &flags);
2670 dump_stack();
2671 }
2672 local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
2673
2674 check_irq_off();
2675 if (gfpflags_allow_blocking(local_flags))
2676 local_irq_enable();
2677
2678 /*
2679 * Get mem for the objs. Attempt to allocate a physical page from
2680 * 'nodeid'.
2681 */
2682 page = kmem_getpages(cachep, local_flags, nodeid);
2683 if (!page)
2684 goto failed;
2685
2686 page_node = page_to_nid(page);
2687 n = get_node(cachep, page_node);
2688
2689 /* Get colour for the slab, and cal the next value. */
2690 n->colour_next++;
2691 if (n->colour_next >= cachep->colour)
2692 n->colour_next = 0;
2693
2694 offset = n->colour_next;
2695 if (offset >= cachep->colour)
2696 offset = 0;
2697
2698 offset *= cachep->colour_off;
2699
2700 /* Get slab management. */
2701 freelist = alloc_slabmgmt(cachep, page, offset,
2702 local_flags & ~GFP_CONSTRAINT_MASK, page_node);
2703 if (OFF_SLAB(cachep) && !freelist)
2704 goto opps1;
2705
2706 slab_map_pages(cachep, page, freelist);
2707
2708 kasan_poison_slab(page);
2709 cache_init_objs(cachep, page);
2710
2711 if (gfpflags_allow_blocking(local_flags))
2712 local_irq_disable();
2713
2714 return page;
2715
2716opps1:
2717 kmem_freepages(cachep, page);
2718failed:
2719 if (gfpflags_allow_blocking(local_flags))
2720 local_irq_disable();
2721 return NULL;
2722}
2723
2724static void cache_grow_end(struct kmem_cache *cachep, struct page *page)
2725{
2726 struct kmem_cache_node *n;
2727 void *list = NULL;
2728
2729 check_irq_off();
2730
2731 if (!page)
2732 return;
2733
2734 INIT_LIST_HEAD(&page->lru);
2735 n = get_node(cachep, page_to_nid(page));
2736
2737 spin_lock(&n->list_lock);
2738 n->total_slabs++;
2739 if (!page->active) {
2740 list_add_tail(&page->lru, &(n->slabs_free));
2741 n->free_slabs++;
2742 } else
2743 fixup_slab_list(cachep, n, page, &list);
2744
2745 STATS_INC_GROWN(cachep);
2746 n->free_objects += cachep->num - page->active;
2747 spin_unlock(&n->list_lock);
2748
2749 fixup_objfreelist_debug(cachep, &list);
2750}
2751
2752#if DEBUG
2753
2754/*
2755 * Perform extra freeing checks:
2756 * - detect bad pointers.
2757 * - POISON/RED_ZONE checking
2758 */
2759static void kfree_debugcheck(const void *objp)
2760{
2761 if (!virt_addr_valid(objp)) {
2762 pr_err("kfree_debugcheck: out of range ptr %lxh\n",
2763 (unsigned long)objp);
2764 BUG();
2765 }
2766}
2767
2768static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
2769{
2770 unsigned long long redzone1, redzone2;
2771
2772 redzone1 = *dbg_redzone1(cache, obj);
2773 redzone2 = *dbg_redzone2(cache, obj);
2774
2775 /*
2776 * Redzone is ok.
2777 */
2778 if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE)
2779 return;
2780
2781 if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE)
2782 slab_error(cache, "double free detected");
2783 else
2784 slab_error(cache, "memory outside object was overwritten");
2785
2786 pr_err("%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
2787 obj, redzone1, redzone2);
2788}
2789
2790static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
2791 unsigned long caller)
2792{
2793 unsigned int objnr;
2794 struct page *page;
2795
2796 BUG_ON(virt_to_cache(objp) != cachep);
2797
2798 objp -= obj_offset(cachep);
2799 kfree_debugcheck(objp);
2800 page = virt_to_head_page(objp);
2801
2802 if (cachep->flags & SLAB_RED_ZONE) {
2803 verify_redzone_free(cachep, objp);
2804 *dbg_redzone1(cachep, objp) = RED_INACTIVE;
2805 *dbg_redzone2(cachep, objp) = RED_INACTIVE;
2806 }
2807 if (cachep->flags & SLAB_STORE_USER) {
2808 set_store_user_dirty(cachep);
2809 *dbg_userword(cachep, objp) = (void *)caller;
2810 }
2811
2812 objnr = obj_to_index(cachep, page, objp);
2813
2814 BUG_ON(objnr >= cachep->num);
2815 BUG_ON(objp != index_to_obj(cachep, page, objnr));
2816
2817 if (cachep->flags & SLAB_POISON) {
2818 poison_obj(cachep, objp, POISON_FREE);
2819 slab_kernel_map(cachep, objp, 0, caller);
2820 }
2821 return objp;
2822}
2823
2824#else
2825#define kfree_debugcheck(x) do { } while(0)
2826#define cache_free_debugcheck(x,objp,z) (objp)
2827#endif
2828
2829static inline void fixup_objfreelist_debug(struct kmem_cache *cachep,
2830 void **list)
2831{
2832#if DEBUG
2833 void *next = *list;
2834 void *objp;
2835
2836 while (next) {
2837 objp = next - obj_offset(cachep);
2838 next = *(void **)next;
2839 poison_obj(cachep, objp, POISON_FREE);
2840 }
2841#endif
2842}
2843
2844static inline void fixup_slab_list(struct kmem_cache *cachep,
2845 struct kmem_cache_node *n, struct page *page,
2846 void **list)
2847{
2848 /* move slabp to correct slabp list: */
2849 list_del(&page->lru);
2850 if (page->active == cachep->num) {
2851 list_add(&page->lru, &n->slabs_full);
2852 if (OBJFREELIST_SLAB(cachep)) {
2853#if DEBUG
2854 /* Poisoning will be done without holding the lock */
2855 if (cachep->flags & SLAB_POISON) {
2856 void **objp = page->freelist;
2857
2858 *objp = *list;
2859 *list = objp;
2860 }
2861#endif
2862 page->freelist = NULL;
2863 }
2864 } else
2865 list_add(&page->lru, &n->slabs_partial);
2866}
2867
2868/* Try to find non-pfmemalloc slab if needed */
2869static noinline struct page *get_valid_first_slab(struct kmem_cache_node *n,
2870 struct page *page, bool pfmemalloc)
2871{
2872 if (!page)
2873 return NULL;
2874
2875 if (pfmemalloc)
2876 return page;
2877
2878 if (!PageSlabPfmemalloc(page))
2879 return page;
2880
2881 /* No need to keep pfmemalloc slab if we have enough free objects */
2882 if (n->free_objects > n->free_limit) {
2883 ClearPageSlabPfmemalloc(page);
2884 return page;
2885 }
2886
2887 /* Move pfmemalloc slab to the end of list to speed up next search */
2888 list_del(&page->lru);
2889 if (!page->active) {
2890 list_add_tail(&page->lru, &n->slabs_free);
2891 n->free_slabs++;
2892 } else
2893 list_add_tail(&page->lru, &n->slabs_partial);
2894
2895 list_for_each_entry(page, &n->slabs_partial, lru) {
2896 if (!PageSlabPfmemalloc(page))
2897 return page;
2898 }
2899
2900 n->free_touched = 1;
2901 list_for_each_entry(page, &n->slabs_free, lru) {
2902 if (!PageSlabPfmemalloc(page)) {
2903 n->free_slabs--;
2904 return page;
2905 }
2906 }
2907
2908 return NULL;
2909}
2910
2911static struct page *get_first_slab(struct kmem_cache_node *n, bool pfmemalloc)
2912{
2913 struct page *page;
2914
2915 assert_spin_locked(&n->list_lock);
2916 page = list_first_entry_or_null(&n->slabs_partial, struct page, lru);
2917 if (!page) {
2918 n->free_touched = 1;
2919 page = list_first_entry_or_null(&n->slabs_free, struct page,
2920 lru);
2921 if (page)
2922 n->free_slabs--;
2923 }
2924
2925 if (sk_memalloc_socks())
2926 page = get_valid_first_slab(n, page, pfmemalloc);
2927
2928 return page;
2929}
2930
2931static noinline void *cache_alloc_pfmemalloc(struct kmem_cache *cachep,
2932 struct kmem_cache_node *n, gfp_t flags)
2933{
2934 struct page *page;
2935 void *obj;
2936 void *list = NULL;
2937
2938 if (!gfp_pfmemalloc_allowed(flags))
2939 return NULL;
2940
2941 spin_lock(&n->list_lock);
2942 page = get_first_slab(n, true);
2943 if (!page) {
2944 spin_unlock(&n->list_lock);
2945 return NULL;
2946 }
2947
2948 obj = slab_get_obj(cachep, page);
2949 n->free_objects--;
2950
2951 fixup_slab_list(cachep, n, page, &list);
2952
2953 spin_unlock(&n->list_lock);
2954 fixup_objfreelist_debug(cachep, &list);
2955
2956 return obj;
2957}
2958
2959/*
2960 * Slab list should be fixed up by fixup_slab_list() for existing slab
2961 * or cache_grow_end() for new slab
2962 */
2963static __always_inline int alloc_block(struct kmem_cache *cachep,
2964 struct array_cache *ac, struct page *page, int batchcount)
2965{
2966 /*
2967 * There must be at least one object available for
2968 * allocation.
2969 */
2970 BUG_ON(page->active >= cachep->num);
2971
2972 while (page->active < cachep->num && batchcount--) {
2973 STATS_INC_ALLOCED(cachep);
2974 STATS_INC_ACTIVE(cachep);
2975 STATS_SET_HIGH(cachep);
2976
2977 ac->entry[ac->avail++] = slab_get_obj(cachep, page);
2978 }
2979
2980 return batchcount;
2981}
2982
2983static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags)
2984{
2985 int batchcount;
2986 struct kmem_cache_node *n;
2987 struct array_cache *ac, *shared;
2988 int node;
2989 void *list = NULL;
2990 struct page *page;
2991
2992 check_irq_off();
2993 node = numa_mem_id();
2994
2995 ac = cpu_cache_get(cachep);
2996 batchcount = ac->batchcount;
2997 if (!ac->touched && batchcount > BATCHREFILL_LIMIT) {
2998 /*
2999 * If there was little recent activity on this cache, then
3000 * perform only a partial refill. Otherwise we could generate
3001 * refill bouncing.
3002 */
3003 batchcount = BATCHREFILL_LIMIT;
3004 }
3005 n = get_node(cachep, node);
3006
3007 BUG_ON(ac->avail > 0 || !n);
3008 shared = READ_ONCE(n->shared);
3009 if (!n->free_objects && (!shared || !shared->avail))
3010 goto direct_grow;
3011
3012 spin_lock(&n->list_lock);
3013 shared = READ_ONCE(n->shared);
3014
3015 /* See if we can refill from the shared array */
3016 if (shared && transfer_objects(ac, shared, batchcount)) {
3017 shared->touched = 1;
3018 goto alloc_done;
3019 }
3020
3021 while (batchcount > 0) {
3022 /* Get slab alloc is to come from. */
3023 page = get_first_slab(n, false);
3024 if (!page)
3025 goto must_grow;
3026
3027 check_spinlock_acquired(cachep);
3028
3029 batchcount = alloc_block(cachep, ac, page, batchcount);
3030 fixup_slab_list(cachep, n, page, &list);
3031 }
3032
3033must_grow:
3034 n->free_objects -= ac->avail;
3035alloc_done:
3036 spin_unlock(&n->list_lock);
3037 fixup_objfreelist_debug(cachep, &list);
3038
3039direct_grow:
3040 if (unlikely(!ac->avail)) {
3041 /* Check if we can use obj in pfmemalloc slab */
3042 if (sk_memalloc_socks()) {
3043 void *obj = cache_alloc_pfmemalloc(cachep, n, flags);
3044
3045 if (obj)
3046 return obj;
3047 }
3048
3049 page = cache_grow_begin(cachep, gfp_exact_node(flags), node);
3050
3051 /*
3052 * cache_grow_begin() can reenable interrupts,
3053 * then ac could change.
3054 */
3055 ac = cpu_cache_get(cachep);
3056 if (!ac->avail && page)
3057 alloc_block(cachep, ac, page, batchcount);
3058 cache_grow_end(cachep, page);
3059
3060 if (!ac->avail)
3061 return NULL;
3062 }
3063 ac->touched = 1;
3064
3065 return ac->entry[--ac->avail];
3066}
3067
3068static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
3069 gfp_t flags)
3070{
3071 might_sleep_if(gfpflags_allow_blocking(flags));
3072}
3073
3074#if DEBUG
3075static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
3076 gfp_t flags, void *objp, unsigned long caller)
3077{
3078 if (!objp)
3079 return objp;
3080 if (cachep->flags & SLAB_POISON) {
3081 check_poison_obj(cachep, objp);
3082 slab_kernel_map(cachep, objp, 1, 0);
3083 poison_obj(cachep, objp, POISON_INUSE);
3084 }
3085 if (cachep->flags & SLAB_STORE_USER)
3086 *dbg_userword(cachep, objp) = (void *)caller;
3087
3088 if (cachep->flags & SLAB_RED_ZONE) {
3089 if (*dbg_redzone1(cachep, objp) != RED_INACTIVE ||
3090 *dbg_redzone2(cachep, objp) != RED_INACTIVE) {
3091 slab_error(cachep, "double free, or memory outside object was overwritten");
3092 pr_err("%p: redzone 1:0x%llx, redzone 2:0x%llx\n",
3093 objp, *dbg_redzone1(cachep, objp),
3094 *dbg_redzone2(cachep, objp));
3095 }
3096 *dbg_redzone1(cachep, objp) = RED_ACTIVE;
3097 *dbg_redzone2(cachep, objp) = RED_ACTIVE;
3098 }
3099
3100 objp += obj_offset(cachep);
3101 if (cachep->ctor && cachep->flags & SLAB_POISON)
3102 cachep->ctor(objp);
3103 if (ARCH_SLAB_MINALIGN &&
3104 ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) {
3105 pr_err("0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
3106 objp, (int)ARCH_SLAB_MINALIGN);
3107 }
3108 return objp;
3109}
3110#else
3111#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
3112#endif
3113
3114static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3115{
3116 void *objp;
3117 struct array_cache *ac;
3118
3119 check_irq_off();
3120
3121 ac = cpu_cache_get(cachep);
3122 if (likely(ac->avail)) {
3123 ac->touched = 1;
3124 objp = ac->entry[--ac->avail];
3125
3126 STATS_INC_ALLOCHIT(cachep);
3127 goto out;
3128 }
3129
3130 STATS_INC_ALLOCMISS(cachep);
3131 objp = cache_alloc_refill(cachep, flags);
3132 /*
3133 * the 'ac' may be updated by cache_alloc_refill(),
3134 * and kmemleak_erase() requires its correct value.
3135 */
3136 ac = cpu_cache_get(cachep);
3137
3138out:
3139 /*
3140 * To avoid a false negative, if an object that is in one of the
3141 * per-CPU caches is leaked, we need to make sure kmemleak doesn't
3142 * treat the array pointers as a reference to the object.
3143 */
3144 if (objp)
3145 kmemleak_erase(&ac->entry[ac->avail]);
3146 return objp;
3147}
3148
3149#ifdef CONFIG_NUMA
3150/*
3151 * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set.
3152 *
3153 * If we are in_interrupt, then process context, including cpusets and
3154 * mempolicy, may not apply and should not be used for allocation policy.
3155 */
3156static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
3157{
3158 int nid_alloc, nid_here;
3159
3160 if (in_interrupt() || (flags & __GFP_THISNODE))
3161 return NULL;
3162 nid_alloc = nid_here = numa_mem_id();
3163 if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD))
3164 nid_alloc = cpuset_slab_spread_node();
3165 else if (current->mempolicy)
3166 nid_alloc = mempolicy_slab_node();
3167 if (nid_alloc != nid_here)
3168 return ____cache_alloc_node(cachep, flags, nid_alloc);
3169 return NULL;
3170}
3171
3172/*
3173 * Fallback function if there was no memory available and no objects on a
3174 * certain node and fall back is permitted. First we scan all the
3175 * available node for available objects. If that fails then we
3176 * perform an allocation without specifying a node. This allows the page
3177 * allocator to do its reclaim / fallback magic. We then insert the
3178 * slab into the proper nodelist and then allocate from it.
3179 */
3180static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
3181{
3182 struct zonelist *zonelist;
3183 struct zoneref *z;
3184 struct zone *zone;
3185 enum zone_type high_zoneidx = gfp_zone(flags);
3186 void *obj = NULL;
3187 struct page *page;
3188 int nid;
3189 unsigned int cpuset_mems_cookie;
3190
3191 if (flags & __GFP_THISNODE)
3192 return NULL;
3193
3194retry_cpuset:
3195 cpuset_mems_cookie = read_mems_allowed_begin();
3196 zonelist = node_zonelist(mempolicy_slab_node(), flags);
3197
3198retry:
3199 /*
3200 * Look through allowed nodes for objects available
3201 * from existing per node queues.
3202 */
3203 for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
3204 nid = zone_to_nid(zone);
3205
3206 if (cpuset_zone_allowed(zone, flags) &&
3207 get_node(cache, nid) &&
3208 get_node(cache, nid)->free_objects) {
3209 obj = ____cache_alloc_node(cache,
3210 gfp_exact_node(flags), nid);
3211 if (obj)
3212 break;
3213 }
3214 }
3215
3216 if (!obj) {
3217 /*
3218 * This allocation will be performed within the constraints
3219 * of the current cpuset / memory policy requirements.
3220 * We may trigger various forms of reclaim on the allowed
3221 * set and go into memory reserves if necessary.
3222 */
3223 page = cache_grow_begin(cache, flags, numa_mem_id());
3224 cache_grow_end(cache, page);
3225 if (page) {
3226 nid = page_to_nid(page);
3227 obj = ____cache_alloc_node(cache,
3228 gfp_exact_node(flags), nid);
3229
3230 /*
3231 * Another processor may allocate the objects in
3232 * the slab since we are not holding any locks.
3233 */
3234 if (!obj)
3235 goto retry;
3236 }
3237 }
3238
3239 if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie)))
3240 goto retry_cpuset;
3241 return obj;
3242}
3243
3244/*
3245 * A interface to enable slab creation on nodeid
3246 */
3247static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
3248 int nodeid)
3249{
3250 struct page *page;
3251 struct kmem_cache_node *n;
3252 void *obj = NULL;
3253 void *list = NULL;
3254
3255 VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES);
3256 n = get_node(cachep, nodeid);
3257 BUG_ON(!n);
3258
3259 check_irq_off();
3260 spin_lock(&n->list_lock);
3261 page = get_first_slab(n, false);
3262 if (!page)
3263 goto must_grow;
3264
3265 check_spinlock_acquired_node(cachep, nodeid);
3266
3267 STATS_INC_NODEALLOCS(cachep);
3268 STATS_INC_ACTIVE(cachep);
3269 STATS_SET_HIGH(cachep);
3270
3271 BUG_ON(page->active == cachep->num);
3272
3273 obj = slab_get_obj(cachep, page);
3274 n->free_objects--;
3275
3276 fixup_slab_list(cachep, n, page, &list);
3277
3278 spin_unlock(&n->list_lock);
3279 fixup_objfreelist_debug(cachep, &list);
3280 return obj;
3281
3282must_grow:
3283 spin_unlock(&n->list_lock);
3284 page = cache_grow_begin(cachep, gfp_exact_node(flags), nodeid);
3285 if (page) {
3286 /* This slab isn't counted yet so don't update free_objects */
3287 obj = slab_get_obj(cachep, page);
3288 }
3289 cache_grow_end(cachep, page);
3290
3291 return obj ? obj : fallback_alloc(cachep, flags);
3292}
3293
3294static __always_inline void *
3295slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
3296 unsigned long caller)
3297{
3298 unsigned long save_flags;
3299 void *ptr;
3300 int slab_node = numa_mem_id();
3301
3302 flags &= gfp_allowed_mask;
3303 cachep = slab_pre_alloc_hook(cachep, flags);
3304 if (unlikely(!cachep))
3305 return NULL;
3306
3307 cache_alloc_debugcheck_before(cachep, flags);
3308 local_irq_save(save_flags);
3309
3310 if (nodeid == NUMA_NO_NODE)
3311 nodeid = slab_node;
3312
3313 if (unlikely(!get_node(cachep, nodeid))) {
3314 /* Node not bootstrapped yet */
3315 ptr = fallback_alloc(cachep, flags);
3316 goto out;
3317 }
3318
3319 if (nodeid == slab_node) {
3320 /*
3321 * Use the locally cached objects if possible.
3322 * However ____cache_alloc does not allow fallback
3323 * to other nodes. It may fail while we still have
3324 * objects on other nodes available.
3325 */
3326 ptr = ____cache_alloc(cachep, flags);
3327 if (ptr)
3328 goto out;
3329 }
3330 /* ___cache_alloc_node can fall back to other nodes */
3331 ptr = ____cache_alloc_node(cachep, flags, nodeid);
3332 out:
3333 local_irq_restore(save_flags);
3334 ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller);
3335
3336 if (unlikely(flags & __GFP_ZERO) && ptr)
3337 memset(ptr, 0, cachep->object_size);
3338
3339 slab_post_alloc_hook(cachep, flags, 1, &ptr);
3340 return ptr;
3341}
3342
3343static __always_inline void *
3344__do_cache_alloc(struct kmem_cache *cache, gfp_t flags)
3345{
3346 void *objp;
3347
3348 if (current->mempolicy || cpuset_do_slab_mem_spread()) {
3349 objp = alternate_node_alloc(cache, flags);
3350 if (objp)
3351 goto out;
3352 }
3353 objp = ____cache_alloc(cache, flags);
3354
3355 /*
3356 * We may just have run out of memory on the local node.
3357 * ____cache_alloc_node() knows how to locate memory on other nodes
3358 */
3359 if (!objp)
3360 objp = ____cache_alloc_node(cache, flags, numa_mem_id());
3361
3362 out:
3363 return objp;
3364}
3365#else
3366
3367static __always_inline void *
3368__do_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3369{
3370 return ____cache_alloc(cachep, flags);
3371}
3372
3373#endif /* CONFIG_NUMA */
3374
3375static __always_inline void *
3376slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller)
3377{
3378 unsigned long save_flags;
3379 void *objp;
3380
3381 flags &= gfp_allowed_mask;
3382 cachep = slab_pre_alloc_hook(cachep, flags);
3383 if (unlikely(!cachep))
3384 return NULL;
3385
3386 cache_alloc_debugcheck_before(cachep, flags);
3387 local_irq_save(save_flags);
3388 objp = __do_cache_alloc(cachep, flags);
3389 local_irq_restore(save_flags);
3390 objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
3391 prefetchw(objp);
3392
3393 if (unlikely(flags & __GFP_ZERO) && objp)
3394 memset(objp, 0, cachep->object_size);
3395
3396 slab_post_alloc_hook(cachep, flags, 1, &objp);
3397 return objp;
3398}
3399
3400/*
3401 * Caller needs to acquire correct kmem_cache_node's list_lock
3402 * @list: List of detached free slabs should be freed by caller
3403 */
3404static void free_block(struct kmem_cache *cachep, void **objpp,
3405 int nr_objects, int node, struct list_head *list)
3406{
3407 int i;
3408 struct kmem_cache_node *n = get_node(cachep, node);
3409 struct page *page;
3410
3411 n->free_objects += nr_objects;
3412
3413 for (i = 0; i < nr_objects; i++) {
3414 void *objp;
3415 struct page *page;
3416
3417 objp = objpp[i];
3418
3419 page = virt_to_head_page(objp);
3420 list_del(&page->lru);
3421 check_spinlock_acquired_node(cachep, node);
3422 slab_put_obj(cachep, page, objp);
3423 STATS_DEC_ACTIVE(cachep);
3424
3425 /* fixup slab chains */
3426 if (page->active == 0) {
3427 list_add(&page->lru, &n->slabs_free);
3428 n->free_slabs++;
3429 } else {
3430 /* Unconditionally move a slab to the end of the
3431 * partial list on free - maximum time for the
3432 * other objects to be freed, too.
3433 */
3434 list_add_tail(&page->lru, &n->slabs_partial);
3435 }
3436 }
3437
3438 while (n->free_objects > n->free_limit && !list_empty(&n->slabs_free)) {
3439 n->free_objects -= cachep->num;
3440
3441 page = list_last_entry(&n->slabs_free, struct page, lru);
3442 list_move(&page->lru, list);
3443 n->free_slabs--;
3444 n->total_slabs--;
3445 }
3446}
3447
3448static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
3449{
3450 int batchcount;
3451 struct kmem_cache_node *n;
3452 int node = numa_mem_id();
3453 LIST_HEAD(list);
3454
3455 batchcount = ac->batchcount;
3456
3457 check_irq_off();
3458 n = get_node(cachep, node);
3459 spin_lock(&n->list_lock);
3460 if (n->shared) {
3461 struct array_cache *shared_array = n->shared;
3462 int max = shared_array->limit - shared_array->avail;
3463 if (max) {
3464 if (batchcount > max)
3465 batchcount = max;
3466 memcpy(&(shared_array->entry[shared_array->avail]),
3467 ac->entry, sizeof(void *) * batchcount);
3468 shared_array->avail += batchcount;
3469 goto free_done;
3470 }
3471 }
3472
3473 free_block(cachep, ac->entry, batchcount, node, &list);
3474free_done:
3475#if STATS
3476 {
3477 int i = 0;
3478 struct page *page;
3479
3480 list_for_each_entry(page, &n->slabs_free, lru) {
3481 BUG_ON(page->active);
3482
3483 i++;
3484 }
3485 STATS_SET_FREEABLE(cachep, i);
3486 }
3487#endif
3488 spin_unlock(&n->list_lock);
3489 slabs_destroy(cachep, &list);
3490 ac->avail -= batchcount;
3491 memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail);
3492}
3493
3494/*
3495 * Release an obj back to its cache. If the obj has a constructed state, it must
3496 * be in this state _before_ it is released. Called with disabled ints.
3497 */
3498static inline void __cache_free(struct kmem_cache *cachep, void *objp,
3499 unsigned long caller)
3500{
3501 /* Put the object into the quarantine, don't touch it for now. */
3502 if (kasan_slab_free(cachep, objp))
3503 return;
3504
3505 ___cache_free(cachep, objp, caller);
3506}
3507
3508void ___cache_free(struct kmem_cache *cachep, void *objp,
3509 unsigned long caller)
3510{
3511 struct array_cache *ac = cpu_cache_get(cachep);
3512
3513 check_irq_off();
3514 kmemleak_free_recursive(objp, cachep->flags);
3515 objp = cache_free_debugcheck(cachep, objp, caller);
3516
3517 kmemcheck_slab_free(cachep, objp, cachep->object_size);
3518
3519 /*
3520 * Skip calling cache_free_alien() when the platform is not numa.
3521 * This will avoid cache misses that happen while accessing slabp (which
3522 * is per page memory reference) to get nodeid. Instead use a global
3523 * variable to skip the call, which is mostly likely to be present in
3524 * the cache.
3525 */
3526 if (nr_online_nodes > 1 && cache_free_alien(cachep, objp))
3527 return;
3528
3529 if (ac->avail < ac->limit) {
3530 STATS_INC_FREEHIT(cachep);
3531 } else {
3532 STATS_INC_FREEMISS(cachep);
3533 cache_flusharray(cachep, ac);
3534 }
3535
3536 if (sk_memalloc_socks()) {
3537 struct page *page = virt_to_head_page(objp);
3538
3539 if (unlikely(PageSlabPfmemalloc(page))) {
3540 cache_free_pfmemalloc(cachep, page, objp);
3541 return;
3542 }
3543 }
3544
3545 ac->entry[ac->avail++] = objp;
3546}
3547
3548/**
3549 * kmem_cache_alloc - Allocate an object
3550 * @cachep: The cache to allocate from.
3551 * @flags: See kmalloc().
3552 *
3553 * Allocate an object from this cache. The flags are only relevant
3554 * if the cache has no available objects.
3555 */
3556void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
3557{
3558 void *ret = slab_alloc(cachep, flags, _RET_IP_);
3559
3560 kasan_slab_alloc(cachep, ret, flags);
3561 trace_kmem_cache_alloc(_RET_IP_, ret,
3562 cachep->object_size, cachep->size, flags);
3563
3564 return ret;
3565}
3566EXPORT_SYMBOL(kmem_cache_alloc);
3567
3568static __always_inline void
3569cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags,
3570 size_t size, void **p, unsigned long caller)
3571{
3572 size_t i;
3573
3574 for (i = 0; i < size; i++)
3575 p[i] = cache_alloc_debugcheck_after(s, flags, p[i], caller);
3576}
3577
3578int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
3579 void **p)
3580{
3581 size_t i;
3582
3583 s = slab_pre_alloc_hook(s, flags);
3584 if (!s)
3585 return 0;
3586
3587 cache_alloc_debugcheck_before(s, flags);
3588
3589 local_irq_disable();
3590 for (i = 0; i < size; i++) {
3591 void *objp = __do_cache_alloc(s, flags);
3592
3593 if (unlikely(!objp))
3594 goto error;
3595 p[i] = objp;
3596 }
3597 local_irq_enable();
3598
3599 cache_alloc_debugcheck_after_bulk(s, flags, size, p, _RET_IP_);
3600
3601 /* Clear memory outside IRQ disabled section */
3602 if (unlikely(flags & __GFP_ZERO))
3603 for (i = 0; i < size; i++)
3604 memset(p[i], 0, s->object_size);
3605
3606 slab_post_alloc_hook(s, flags, size, p);
3607 /* FIXME: Trace call missing. Christoph would like a bulk variant */
3608 return size;
3609error:
3610 local_irq_enable();
3611 cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_);
3612 slab_post_alloc_hook(s, flags, i, p);
3613 __kmem_cache_free_bulk(s, i, p);
3614 return 0;
3615}
3616EXPORT_SYMBOL(kmem_cache_alloc_bulk);
3617
3618#ifdef CONFIG_TRACING
3619void *
3620kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size)
3621{
3622 void *ret;
3623
3624 ret = slab_alloc(cachep, flags, _RET_IP_);
3625
3626 kasan_kmalloc(cachep, ret, size, flags);
3627 trace_kmalloc(_RET_IP_, ret,
3628 size, cachep->size, flags);
3629 return ret;
3630}
3631EXPORT_SYMBOL(kmem_cache_alloc_trace);
3632#endif
3633
3634#ifdef CONFIG_NUMA
3635/**
3636 * kmem_cache_alloc_node - Allocate an object on the specified node
3637 * @cachep: The cache to allocate from.
3638 * @flags: See kmalloc().
3639 * @nodeid: node number of the target node.
3640 *
3641 * Identical to kmem_cache_alloc but it will allocate memory on the given
3642 * node, which can improve the performance for cpu bound structures.
3643 *
3644 * Fallback to other node is possible if __GFP_THISNODE is not set.
3645 */
3646void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
3647{
3648 void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
3649
3650 kasan_slab_alloc(cachep, ret, flags);
3651 trace_kmem_cache_alloc_node(_RET_IP_, ret,
3652 cachep->object_size, cachep->size,
3653 flags, nodeid);
3654
3655 return ret;
3656}
3657EXPORT_SYMBOL(kmem_cache_alloc_node);
3658
3659#ifdef CONFIG_TRACING
3660void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep,
3661 gfp_t flags,
3662 int nodeid,
3663 size_t size)
3664{
3665 void *ret;
3666
3667 ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);
3668
3669 kasan_kmalloc(cachep, ret, size, flags);
3670 trace_kmalloc_node(_RET_IP_, ret,
3671 size, cachep->size,
3672 flags, nodeid);
3673 return ret;
3674}
3675EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
3676#endif
3677
3678static __always_inline void *
3679__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller)
3680{
3681 struct kmem_cache *cachep;
3682 void *ret;
3683
3684 cachep = kmalloc_slab(size, flags);
3685 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3686 return cachep;
3687 ret = kmem_cache_alloc_node_trace(cachep, flags, node, size);
3688 kasan_kmalloc(cachep, ret, size, flags);
3689
3690 return ret;
3691}
3692
3693void *__kmalloc_node(size_t size, gfp_t flags, int node)
3694{
3695 return __do_kmalloc_node(size, flags, node, _RET_IP_);
3696}
3697EXPORT_SYMBOL(__kmalloc_node);
3698
3699void *__kmalloc_node_track_caller(size_t size, gfp_t flags,
3700 int node, unsigned long caller)
3701{
3702 return __do_kmalloc_node(size, flags, node, caller);
3703}
3704EXPORT_SYMBOL(__kmalloc_node_track_caller);
3705#endif /* CONFIG_NUMA */
3706
3707/**
3708 * __do_kmalloc - allocate memory
3709 * @size: how many bytes of memory are required.
3710 * @flags: the type of memory to allocate (see kmalloc).
3711 * @caller: function caller for debug tracking of the caller
3712 */
3713static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
3714 unsigned long caller)
3715{
3716 struct kmem_cache *cachep;
3717 void *ret;
3718
3719 cachep = kmalloc_slab(size, flags);
3720 if (unlikely(ZERO_OR_NULL_PTR(cachep)))
3721 return cachep;
3722 ret = slab_alloc(cachep, flags, caller);
3723
3724 kasan_kmalloc(cachep, ret, size, flags);
3725 trace_kmalloc(caller, ret,
3726 size, cachep->size, flags);
3727
3728 return ret;
3729}
3730
3731void *__kmalloc(size_t size, gfp_t flags)
3732{
3733 return __do_kmalloc(size, flags, _RET_IP_);
3734}
3735EXPORT_SYMBOL(__kmalloc);
3736
3737void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller)
3738{
3739 return __do_kmalloc(size, flags, caller);
3740}
3741EXPORT_SYMBOL(__kmalloc_track_caller);
3742
3743/**
3744 * kmem_cache_free - Deallocate an object
3745 * @cachep: The cache the allocation was from.
3746 * @objp: The previously allocated object.
3747 *
3748 * Free an object which was previously allocated from this
3749 * cache.
3750 */
3751void kmem_cache_free(struct kmem_cache *cachep, void *objp)
3752{
3753 unsigned long flags;
3754 cachep = cache_from_obj(cachep, objp);
3755 if (!cachep)
3756 return;
3757
3758 local_irq_save(flags);
3759 debug_check_no_locks_freed(objp, cachep->object_size);
3760 if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
3761 debug_check_no_obj_freed(objp, cachep->object_size);
3762 __cache_free(cachep, objp, _RET_IP_);
3763 local_irq_restore(flags);
3764
3765 trace_kmem_cache_free(_RET_IP_, objp);
3766}
3767EXPORT_SYMBOL(kmem_cache_free);
3768
3769void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p)
3770{
3771 struct kmem_cache *s;
3772 size_t i;
3773
3774 local_irq_disable();
3775 for (i = 0; i < size; i++) {
3776 void *objp = p[i];
3777
3778 if (!orig_s) /* called via kfree_bulk */
3779 s = virt_to_cache(objp);
3780 else
3781 s = cache_from_obj(orig_s, objp);
3782
3783 debug_check_no_locks_freed(objp, s->object_size);
3784 if (!(s->flags & SLAB_DEBUG_OBJECTS))
3785 debug_check_no_obj_freed(objp, s->object_size);
3786
3787 __cache_free(s, objp, _RET_IP_);
3788 }
3789 local_irq_enable();
3790
3791 /* FIXME: add tracing */
3792}
3793EXPORT_SYMBOL(kmem_cache_free_bulk);
3794
3795/**
3796 * kfree - free previously allocated memory
3797 * @objp: pointer returned by kmalloc.
3798 *
3799 * If @objp is NULL, no operation is performed.
3800 *
3801 * Don't free memory not originally allocated by kmalloc()
3802 * or you will run into trouble.
3803 */
3804void kfree(const void *objp)
3805{
3806 struct kmem_cache *c;
3807 unsigned long flags;
3808
3809 trace_kfree(_RET_IP_, objp);
3810
3811 if (unlikely(ZERO_OR_NULL_PTR(objp)))
3812 return;
3813 local_irq_save(flags);
3814 kfree_debugcheck(objp);
3815 c = virt_to_cache(objp);
3816 debug_check_no_locks_freed(objp, c->object_size);
3817
3818 debug_check_no_obj_freed(objp, c->object_size);
3819 __cache_free(c, (void *)objp, _RET_IP_);
3820 local_irq_restore(flags);
3821}
3822EXPORT_SYMBOL(kfree);
3823
3824/*
3825 * This initializes kmem_cache_node or resizes various caches for all nodes.
3826 */
3827static int setup_kmem_cache_nodes(struct kmem_cache *cachep, gfp_t gfp)
3828{
3829 int ret;
3830 int node;
3831 struct kmem_cache_node *n;
3832
3833 for_each_online_node(node) {
3834 ret = setup_kmem_cache_node(cachep, node, gfp, true);
3835 if (ret)
3836 goto fail;
3837
3838 }
3839
3840 return 0;
3841
3842fail:
3843 if (!cachep->list.next) {
3844 /* Cache is not active yet. Roll back what we did */
3845 node--;
3846 while (node >= 0) {
3847 n = get_node(cachep, node);
3848 if (n) {
3849 kfree(n->shared);
3850 free_alien_cache(n->alien);
3851 kfree(n);
3852 cachep->node[node] = NULL;
3853 }
3854 node--;
3855 }
3856 }
3857 return -ENOMEM;
3858}
3859
3860/* Always called with the slab_mutex held */
3861static int __do_tune_cpucache(struct kmem_cache *cachep, int limit,
3862 int batchcount, int shared, gfp_t gfp)
3863{
3864 struct array_cache __percpu *cpu_cache, *prev;
3865 int cpu;
3866
3867 cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount);
3868 if (!cpu_cache)
3869 return -ENOMEM;
3870
3871 prev = cachep->cpu_cache;
3872 cachep->cpu_cache = cpu_cache;
3873 kick_all_cpus_sync();
3874
3875 check_irq_on();
3876 cachep->batchcount = batchcount;
3877 cachep->limit = limit;
3878 cachep->shared = shared;
3879
3880 if (!prev)
3881 goto setup_node;
3882
3883 for_each_online_cpu(cpu) {
3884 LIST_HEAD(list);
3885 int node;
3886 struct kmem_cache_node *n;
3887 struct array_cache *ac = per_cpu_ptr(prev, cpu);
3888
3889 node = cpu_to_mem(cpu);
3890 n = get_node(cachep, node);
3891 spin_lock_irq(&n->list_lock);
3892 free_block(cachep, ac->entry, ac->avail, node, &list);
3893 spin_unlock_irq(&n->list_lock);
3894 slabs_destroy(cachep, &list);
3895 }
3896 free_percpu(prev);
3897
3898setup_node:
3899 return setup_kmem_cache_nodes(cachep, gfp);
3900}
3901
3902static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
3903 int batchcount, int shared, gfp_t gfp)
3904{
3905 int ret;
3906 struct kmem_cache *c;
3907
3908 ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
3909
3910 if (slab_state < FULL)
3911 return ret;
3912
3913 if ((ret < 0) || !is_root_cache(cachep))
3914 return ret;
3915
3916 lockdep_assert_held(&slab_mutex);
3917 for_each_memcg_cache(c, cachep) {
3918 /* return value determined by the root cache only */
3919 __do_tune_cpucache(c, limit, batchcount, shared, gfp);
3920 }
3921
3922 return ret;
3923}
3924
3925/* Called with slab_mutex held always */
3926static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp)
3927{
3928 int err;
3929 int limit = 0;
3930 int shared = 0;
3931 int batchcount = 0;
3932
3933 err = cache_random_seq_create(cachep, cachep->num, gfp);
3934 if (err)
3935 goto end;
3936
3937 if (!is_root_cache(cachep)) {
3938 struct kmem_cache *root = memcg_root_cache(cachep);
3939 limit = root->limit;
3940 shared = root->shared;
3941 batchcount = root->batchcount;
3942 }
3943
3944 if (limit && shared && batchcount)
3945 goto skip_setup;
3946 /*
3947 * The head array serves three purposes:
3948 * - create a LIFO ordering, i.e. return objects that are cache-warm
3949 * - reduce the number of spinlock operations.
3950 * - reduce the number of linked list operations on the slab and
3951 * bufctl chains: array operations are cheaper.
3952 * The numbers are guessed, we should auto-tune as described by
3953 * Bonwick.
3954 */
3955 if (cachep->size > 131072)
3956 limit = 1;
3957 else if (cachep->size > PAGE_SIZE)
3958 limit = 8;
3959 else if (cachep->size > 1024)
3960 limit = 24;
3961 else if (cachep->size > 256)
3962 limit = 54;
3963 else
3964 limit = 120;
3965
3966 /*
3967 * CPU bound tasks (e.g. network routing) can exhibit cpu bound
3968 * allocation behaviour: Most allocs on one cpu, most free operations
3969 * on another cpu. For these cases, an efficient object passing between
3970 * cpus is necessary. This is provided by a shared array. The array
3971 * replaces Bonwick's magazine layer.
3972 * On uniprocessor, it's functionally equivalent (but less efficient)
3973 * to a larger limit. Thus disabled by default.
3974 */
3975 shared = 0;
3976 if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1)
3977 shared = 8;
3978
3979#if DEBUG
3980 /*
3981 * With debugging enabled, large batchcount lead to excessively long
3982 * periods with disabled local interrupts. Limit the batchcount
3983 */
3984 if (limit > 32)
3985 limit = 32;
3986#endif
3987 batchcount = (limit + 1) / 2;
3988skip_setup:
3989 err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp);
3990end:
3991 if (err)
3992 pr_err("enable_cpucache failed for %s, error %d\n",
3993 cachep->name, -err);
3994 return err;
3995}
3996
3997/*
3998 * Drain an array if it contains any elements taking the node lock only if
3999 * necessary. Note that the node listlock also protects the array_cache
4000 * if drain_array() is used on the shared array.
4001 */
4002static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n,
4003 struct array_cache *ac, int node)
4004{
4005 LIST_HEAD(list);
4006
4007 /* ac from n->shared can be freed if we don't hold the slab_mutex. */
4008 check_mutex_acquired();
4009
4010 if (!ac || !ac->avail)
4011 return;
4012
4013 if (ac->touched) {
4014 ac->touched = 0;
4015 return;
4016 }
4017
4018 spin_lock_irq(&n->list_lock);
4019 drain_array_locked(cachep, ac, node, false, &list);
4020 spin_unlock_irq(&n->list_lock);
4021
4022 slabs_destroy(cachep, &list);
4023}
4024
4025/**
4026 * cache_reap - Reclaim memory from caches.
4027 * @w: work descriptor
4028 *
4029 * Called from workqueue/eventd every few seconds.
4030 * Purpose:
4031 * - clear the per-cpu caches for this CPU.
4032 * - return freeable pages to the main free memory pool.
4033 *
4034 * If we cannot acquire the cache chain mutex then just give up - we'll try
4035 * again on the next iteration.
4036 */
4037static void cache_reap(struct work_struct *w)
4038{
4039 struct kmem_cache *searchp;
4040 struct kmem_cache_node *n;
4041 int node = numa_mem_id();
4042 struct delayed_work *work = to_delayed_work(w);
4043
4044 if (!mutex_trylock(&slab_mutex))
4045 /* Give up. Setup the next iteration. */
4046 goto out;
4047
4048 list_for_each_entry(searchp, &slab_caches, list) {
4049 check_irq_on();
4050
4051 /*
4052 * We only take the node lock if absolutely necessary and we
4053 * have established with reasonable certainty that
4054 * we can do some work if the lock was obtained.
4055 */
4056 n = get_node(searchp, node);
4057
4058 reap_alien(searchp, n);
4059
4060 drain_array(searchp, n, cpu_cache_get(searchp), node);
4061
4062 /*
4063 * These are racy checks but it does not matter
4064 * if we skip one check or scan twice.
4065 */
4066 if (time_after(n->next_reap, jiffies))
4067 goto next;
4068
4069 n->next_reap = jiffies + REAPTIMEOUT_NODE;
4070
4071 drain_array(searchp, n, n->shared, node);
4072
4073 if (n->free_touched)
4074 n->free_touched = 0;
4075 else {
4076 int freed;
4077
4078 freed = drain_freelist(searchp, n, (n->free_limit +
4079 5 * searchp->num - 1) / (5 * searchp->num));
4080 STATS_ADD_REAPED(searchp, freed);
4081 }
4082next:
4083 cond_resched();
4084 }
4085 check_irq_on();
4086 mutex_unlock(&slab_mutex);
4087 next_reap_node();
4088out:
4089 /* Set up the next iteration */
4090 schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC));
4091}
4092
4093#ifdef CONFIG_SLABINFO
4094void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
4095{
4096 unsigned long active_objs, num_objs, active_slabs;
4097 unsigned long total_slabs = 0, free_objs = 0, shared_avail = 0;
4098 unsigned long free_slabs = 0;
4099 int node;
4100 struct kmem_cache_node *n;
4101
4102 for_each_kmem_cache_node(cachep, node, n) {
4103 check_irq_on();
4104 spin_lock_irq(&n->list_lock);
4105
4106 total_slabs += n->total_slabs;
4107 free_slabs += n->free_slabs;
4108 free_objs += n->free_objects;
4109
4110 if (n->shared)
4111 shared_avail += n->shared->avail;
4112
4113 spin_unlock_irq(&n->list_lock);
4114 }
4115 num_objs = total_slabs * cachep->num;
4116 active_slabs = total_slabs - free_slabs;
4117 active_objs = num_objs - free_objs;
4118
4119 sinfo->active_objs = active_objs;
4120 sinfo->num_objs = num_objs;
4121 sinfo->active_slabs = active_slabs;
4122 sinfo->num_slabs = total_slabs;
4123 sinfo->shared_avail = shared_avail;
4124 sinfo->limit = cachep->limit;
4125 sinfo->batchcount = cachep->batchcount;
4126 sinfo->shared = cachep->shared;
4127 sinfo->objects_per_slab = cachep->num;
4128 sinfo->cache_order = cachep->gfporder;
4129}
4130
4131void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep)
4132{
4133#if STATS
4134 { /* node stats */
4135 unsigned long high = cachep->high_mark;
4136 unsigned long allocs = cachep->num_allocations;
4137 unsigned long grown = cachep->grown;
4138 unsigned long reaped = cachep->reaped;
4139 unsigned long errors = cachep->errors;
4140 unsigned long max_freeable = cachep->max_freeable;
4141 unsigned long node_allocs = cachep->node_allocs;
4142 unsigned long node_frees = cachep->node_frees;
4143 unsigned long overflows = cachep->node_overflow;
4144
4145 seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu",
4146 allocs, high, grown,
4147 reaped, errors, max_freeable, node_allocs,
4148 node_frees, overflows);
4149 }
4150 /* cpu stats */
4151 {
4152 unsigned long allochit = atomic_read(&cachep->allochit);
4153 unsigned long allocmiss = atomic_read(&cachep->allocmiss);
4154 unsigned long freehit = atomic_read(&cachep->freehit);
4155 unsigned long freemiss = atomic_read(&cachep->freemiss);
4156
4157 seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu",
4158 allochit, allocmiss, freehit, freemiss);
4159 }
4160#endif
4161}
4162
4163#define MAX_SLABINFO_WRITE 128
4164/**
4165 * slabinfo_write - Tuning for the slab allocator
4166 * @file: unused
4167 * @buffer: user buffer
4168 * @count: data length
4169 * @ppos: unused
4170 */
4171ssize_t slabinfo_write(struct file *file, const char __user *buffer,
4172 size_t count, loff_t *ppos)
4173{
4174 char kbuf[MAX_SLABINFO_WRITE + 1], *tmp;
4175 int limit, batchcount, shared, res;
4176 struct kmem_cache *cachep;
4177
4178 if (count > MAX_SLABINFO_WRITE)
4179 return -EINVAL;
4180 if (copy_from_user(&kbuf, buffer, count))
4181 return -EFAULT;
4182 kbuf[MAX_SLABINFO_WRITE] = '\0';
4183
4184 tmp = strchr(kbuf, ' ');
4185 if (!tmp)
4186 return -EINVAL;
4187 *tmp = '\0';
4188 tmp++;
4189 if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3)
4190 return -EINVAL;
4191
4192 /* Find the cache in the chain of caches. */
4193 mutex_lock(&slab_mutex);
4194 res = -EINVAL;
4195 list_for_each_entry(cachep, &slab_caches, list) {
4196 if (!strcmp(cachep->name, kbuf)) {
4197 if (limit < 1 || batchcount < 1 ||
4198 batchcount > limit || shared < 0) {
4199 res = 0;
4200 } else {
4201 res = do_tune_cpucache(cachep, limit,
4202 batchcount, shared,
4203 GFP_KERNEL);
4204 }
4205 break;
4206 }
4207 }
4208 mutex_unlock(&slab_mutex);
4209 if (res >= 0)
4210 res = count;
4211 return res;
4212}
4213
4214#ifdef CONFIG_DEBUG_SLAB_LEAK
4215
4216static inline int add_caller(unsigned long *n, unsigned long v)
4217{
4218 unsigned long *p;
4219 int l;
4220 if (!v)
4221 return 1;
4222 l = n[1];
4223 p = n + 2;
4224 while (l) {
4225 int i = l/2;
4226 unsigned long *q = p + 2 * i;
4227 if (*q == v) {
4228 q[1]++;
4229 return 1;
4230 }
4231 if (*q > v) {
4232 l = i;
4233 } else {
4234 p = q + 2;
4235 l -= i + 1;
4236 }
4237 }
4238 if (++n[1] == n[0])
4239 return 0;
4240 memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n));
4241 p[0] = v;
4242 p[1] = 1;
4243 return 1;
4244}
4245
4246static void handle_slab(unsigned long *n, struct kmem_cache *c,
4247 struct page *page)
4248{
4249 void *p;
4250 int i, j;
4251 unsigned long v;
4252
4253 if (n[0] == n[1])
4254 return;
4255 for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) {
4256 bool active = true;
4257
4258 for (j = page->active; j < c->num; j++) {
4259 if (get_free_obj(page, j) == i) {
4260 active = false;
4261 break;
4262 }
4263 }
4264
4265 if (!active)
4266 continue;
4267
4268 /*
4269 * probe_kernel_read() is used for DEBUG_PAGEALLOC. page table
4270 * mapping is established when actual object allocation and
4271 * we could mistakenly access the unmapped object in the cpu
4272 * cache.
4273 */
4274 if (probe_kernel_read(&v, dbg_userword(c, p), sizeof(v)))
4275 continue;
4276
4277 if (!add_caller(n, v))
4278 return;
4279 }
4280}
4281
4282static void show_symbol(struct seq_file *m, unsigned long address)
4283{
4284#ifdef CONFIG_KALLSYMS
4285 unsigned long offset, size;
4286 char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN];
4287
4288 if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
4289 seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
4290 if (modname[0])
4291 seq_printf(m, " [%s]", modname);
4292 return;
4293 }
4294#endif
4295 seq_printf(m, "%p", (void *)address);
4296}
4297
4298static int leaks_show(struct seq_file *m, void *p)
4299{
4300 struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list);
4301 struct page *page;
4302 struct kmem_cache_node *n;
4303 const char *name;
4304 unsigned long *x = m->private;
4305 int node;
4306 int i;
4307
4308 if (!(cachep->flags & SLAB_STORE_USER))
4309 return 0;
4310 if (!(cachep->flags & SLAB_RED_ZONE))
4311 return 0;
4312
4313 /*
4314 * Set store_user_clean and start to grab stored user information
4315 * for all objects on this cache. If some alloc/free requests comes
4316 * during the processing, information would be wrong so restart
4317 * whole processing.
4318 */
4319 do {
4320 set_store_user_clean(cachep);
4321 drain_cpu_caches(cachep);
4322
4323 x[1] = 0;
4324
4325 for_each_kmem_cache_node(cachep, node, n) {
4326
4327 check_irq_on();
4328 spin_lock_irq(&n->list_lock);
4329
4330 list_for_each_entry(page, &n->slabs_full, lru)
4331 handle_slab(x, cachep, page);
4332 list_for_each_entry(page, &n->slabs_partial, lru)
4333 handle_slab(x, cachep, page);
4334 spin_unlock_irq(&n->list_lock);
4335 }
4336 } while (!is_store_user_clean(cachep));
4337
4338 name = cachep->name;
4339 if (x[0] == x[1]) {
4340 /* Increase the buffer size */
4341 mutex_unlock(&slab_mutex);
4342 m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL);
4343 if (!m->private) {
4344 /* Too bad, we are really out */
4345 m->private = x;
4346 mutex_lock(&slab_mutex);
4347 return -ENOMEM;
4348 }
4349 *(unsigned long *)m->private = x[0] * 2;
4350 kfree(x);
4351 mutex_lock(&slab_mutex);
4352 /* Now make sure this entry will be retried */
4353 m->count = m->size;
4354 return 0;
4355 }
4356 for (i = 0; i < x[1]; i++) {
4357 seq_printf(m, "%s: %lu ", name, x[2*i+3]);
4358 show_symbol(m, x[2*i+2]);
4359 seq_putc(m, '\n');
4360 }
4361
4362 return 0;
4363}
4364
4365static const struct seq_operations slabstats_op = {
4366 .start = slab_start,
4367 .next = slab_next,
4368 .stop = slab_stop,
4369 .show = leaks_show,
4370};
4371
4372static int slabstats_open(struct inode *inode, struct file *file)
4373{
4374 unsigned long *n;
4375
4376 n = __seq_open_private(file, &slabstats_op, PAGE_SIZE);
4377 if (!n)
4378 return -ENOMEM;
4379
4380 *n = PAGE_SIZE / (2 * sizeof(unsigned long));
4381
4382 return 0;
4383}
4384
4385static const struct file_operations proc_slabstats_operations = {
4386 .open = slabstats_open,
4387 .read = seq_read,
4388 .llseek = seq_lseek,
4389 .release = seq_release_private,
4390};
4391#endif
4392
4393static int __init slab_proc_init(void)
4394{
4395#ifdef CONFIG_DEBUG_SLAB_LEAK
4396 proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations);
4397#endif
4398 return 0;
4399}
4400module_init(slab_proc_init);
4401#endif
4402
4403#ifdef CONFIG_HARDENED_USERCOPY
4404/*
4405 * Rejects objects that are incorrectly sized.
4406 *
4407 * Returns NULL if check passes, otherwise const char * to name of cache
4408 * to indicate an error.
4409 */
4410const char *__check_heap_object(const void *ptr, unsigned long n,
4411 struct page *page)
4412{
4413 struct kmem_cache *cachep;
4414 unsigned int objnr;
4415 unsigned long offset;
4416
4417 /* Find and validate object. */
4418 cachep = page->slab_cache;
4419 objnr = obj_to_index(cachep, page, (void *)ptr);
4420 BUG_ON(objnr >= cachep->num);
4421
4422 /* Find offset within object. */
4423 offset = ptr - index_to_obj(cachep, page, objnr) - obj_offset(cachep);
4424
4425 /* Allow address range falling entirely within object size. */
4426 if (offset <= cachep->object_size && n <= cachep->object_size - offset)
4427 return NULL;
4428
4429 return cachep->name;
4430}
4431#endif /* CONFIG_HARDENED_USERCOPY */
4432
4433/**
4434 * ksize - get the actual amount of memory allocated for a given object
4435 * @objp: Pointer to the object
4436 *
4437 * kmalloc may internally round up allocations and return more memory
4438 * than requested. ksize() can be used to determine the actual amount of
4439 * memory allocated. The caller may use this additional memory, even though
4440 * a smaller amount of memory was initially specified with the kmalloc call.
4441 * The caller must guarantee that objp points to a valid object previously
4442 * allocated with either kmalloc() or kmem_cache_alloc(). The object
4443 * must not be freed during the duration of the call.
4444 */
4445size_t ksize(const void *objp)
4446{
4447 size_t size;
4448
4449 BUG_ON(!objp);
4450 if (unlikely(objp == ZERO_SIZE_PTR))
4451 return 0;
4452
4453 size = virt_to_cache(objp)->object_size;
4454 /* We assume that ksize callers could use the whole allocated area,
4455 * so we need to unpoison this area.
4456 */
4457 kasan_unpoison_shadow(objp, size);
4458
4459 return size;
4460}
4461EXPORT_SYMBOL(ksize);