xref: /openbmc/linux/mm/slub.c (revision 74de3792)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SLUB: A slab allocator that limits cache line use instead of queuing
4  * objects in per cpu and per node lists.
5  *
6  * The allocator synchronizes using per slab locks or atomic operations
7  * and only uses a centralized lock to manage a pool of partial slabs.
8  *
9  * (C) 2007 SGI, Christoph Lameter
10  * (C) 2011 Linux Foundation, Christoph Lameter
11  */
12 
13 #include <linux/mm.h>
14 #include <linux/swap.h> /* struct reclaim_state */
15 #include <linux/module.h>
16 #include <linux/bit_spinlock.h>
17 #include <linux/interrupt.h>
18 #include <linux/swab.h>
19 #include <linux/bitops.h>
20 #include <linux/slab.h>
21 #include "slab.h"
22 #include <linux/proc_fs.h>
23 #include <linux/seq_file.h>
24 #include <linux/kasan.h>
25 #include <linux/cpu.h>
26 #include <linux/cpuset.h>
27 #include <linux/mempolicy.h>
28 #include <linux/ctype.h>
29 #include <linux/debugobjects.h>
30 #include <linux/kallsyms.h>
31 #include <linux/kfence.h>
32 #include <linux/memory.h>
33 #include <linux/math64.h>
34 #include <linux/fault-inject.h>
35 #include <linux/stacktrace.h>
36 #include <linux/prefetch.h>
37 #include <linux/memcontrol.h>
38 #include <linux/random.h>
39 #include <kunit/test.h>
40 
41 #include <linux/debugfs.h>
42 #include <trace/events/kmem.h>
43 
44 #include "internal.h"
45 
46 /*
47  * Lock order:
48  *   1. slab_mutex (Global Mutex)
49  *   2. node->list_lock (Spinlock)
50  *   3. kmem_cache->cpu_slab->lock (Local lock)
51  *   4. slab_lock(slab) (Only on some arches or for debugging)
52  *   5. object_map_lock (Only for debugging)
53  *
54  *   slab_mutex
55  *
56  *   The role of the slab_mutex is to protect the list of all the slabs
57  *   and to synchronize major metadata changes to slab cache structures.
58  *   Also synchronizes memory hotplug callbacks.
59  *
60  *   slab_lock
61  *
62  *   The slab_lock is a wrapper around the page lock, thus it is a bit
63  *   spinlock.
64  *
65  *   The slab_lock is only used for debugging and on arches that do not
66  *   have the ability to do a cmpxchg_double. It only protects:
67  *	A. slab->freelist	-> List of free objects in a slab
68  *	B. slab->inuse		-> Number of objects in use
69  *	C. slab->objects	-> Number of objects in slab
70  *	D. slab->frozen		-> frozen state
71  *
72  *   Frozen slabs
73  *
74  *   If a slab is frozen then it is exempt from list management. It is not
75  *   on any list except per cpu partial list. The processor that froze the
76  *   slab is the one who can perform list operations on the slab. Other
77  *   processors may put objects onto the freelist but the processor that
78  *   froze the slab is the only one that can retrieve the objects from the
79  *   slab's freelist.
80  *
81  *   list_lock
82  *
83  *   The list_lock protects the partial and full list on each node and
84  *   the partial slab counter. If taken then no new slabs may be added or
85  *   removed from the lists nor make the number of partial slabs be modified.
86  *   (Note that the total number of slabs is an atomic value that may be
87  *   modified without taking the list lock).
88  *
89  *   The list_lock is a centralized lock and thus we avoid taking it as
90  *   much as possible. As long as SLUB does not have to handle partial
91  *   slabs, operations can continue without any centralized lock. F.e.
92  *   allocating a long series of objects that fill up slabs does not require
93  *   the list lock.
94  *
95  *   cpu_slab->lock local lock
96  *
97  *   This locks protect slowpath manipulation of all kmem_cache_cpu fields
98  *   except the stat counters. This is a percpu structure manipulated only by
99  *   the local cpu, so the lock protects against being preempted or interrupted
100  *   by an irq. Fast path operations rely on lockless operations instead.
101  *   On PREEMPT_RT, the local lock does not actually disable irqs (and thus
102  *   prevent the lockless operations), so fastpath operations also need to take
103  *   the lock and are no longer lockless.
104  *
105  *   lockless fastpaths
106  *
107  *   The fast path allocation (slab_alloc_node()) and freeing (do_slab_free())
108  *   are fully lockless when satisfied from the percpu slab (and when
109  *   cmpxchg_double is possible to use, otherwise slab_lock is taken).
110  *   They also don't disable preemption or migration or irqs. They rely on
111  *   the transaction id (tid) field to detect being preempted or moved to
112  *   another cpu.
113  *
114  *   irq, preemption, migration considerations
115  *
116  *   Interrupts are disabled as part of list_lock or local_lock operations, or
117  *   around the slab_lock operation, in order to make the slab allocator safe
118  *   to use in the context of an irq.
119  *
120  *   In addition, preemption (or migration on PREEMPT_RT) is disabled in the
121  *   allocation slowpath, bulk allocation, and put_cpu_partial(), so that the
122  *   local cpu doesn't change in the process and e.g. the kmem_cache_cpu pointer
123  *   doesn't have to be revalidated in each section protected by the local lock.
124  *
125  * SLUB assigns one slab for allocation to each processor.
126  * Allocations only occur from these slabs called cpu slabs.
127  *
128  * Slabs with free elements are kept on a partial list and during regular
129  * operations no list for full slabs is used. If an object in a full slab is
130  * freed then the slab will show up again on the partial lists.
131  * We track full slabs for debugging purposes though because otherwise we
132  * cannot scan all objects.
133  *
134  * Slabs are freed when they become empty. Teardown and setup is
135  * minimal so we rely on the page allocators per cpu caches for
136  * fast frees and allocs.
137  *
138  * slab->frozen		The slab is frozen and exempt from list processing.
139  * 			This means that the slab is dedicated to a purpose
140  * 			such as satisfying allocations for a specific
141  * 			processor. Objects may be freed in the slab while
142  * 			it is frozen but slab_free will then skip the usual
143  * 			list operations. It is up to the processor holding
144  * 			the slab to integrate the slab into the slab lists
145  * 			when the slab is no longer needed.
146  *
147  * 			One use of this flag is to mark slabs that are
148  * 			used for allocations. Then such a slab becomes a cpu
149  * 			slab. The cpu slab may be equipped with an additional
150  * 			freelist that allows lockless access to
151  * 			free objects in addition to the regular freelist
152  * 			that requires the slab lock.
153  *
154  * SLAB_DEBUG_FLAGS	Slab requires special handling due to debug
155  * 			options set. This moves	slab handling out of
156  * 			the fast path and disables lockless freelists.
157  */
158 
159 /*
160  * We could simply use migrate_disable()/enable() but as long as it's a
161  * function call even on !PREEMPT_RT, use inline preempt_disable() there.
162  */
163 #ifndef CONFIG_PREEMPT_RT
164 #define slub_get_cpu_ptr(var)	get_cpu_ptr(var)
165 #define slub_put_cpu_ptr(var)	put_cpu_ptr(var)
166 #else
167 #define slub_get_cpu_ptr(var)		\
168 ({					\
169 	migrate_disable();		\
170 	this_cpu_ptr(var);		\
171 })
172 #define slub_put_cpu_ptr(var)		\
173 do {					\
174 	(void)(var);			\
175 	migrate_enable();		\
176 } while (0)
177 #endif
178 
179 #ifdef CONFIG_SLUB_DEBUG
180 #ifdef CONFIG_SLUB_DEBUG_ON
181 DEFINE_STATIC_KEY_TRUE(slub_debug_enabled);
182 #else
183 DEFINE_STATIC_KEY_FALSE(slub_debug_enabled);
184 #endif
185 #endif		/* CONFIG_SLUB_DEBUG */
186 
187 static inline bool kmem_cache_debug(struct kmem_cache *s)
188 {
189 	return kmem_cache_debug_flags(s, SLAB_DEBUG_FLAGS);
190 }
191 
192 void *fixup_red_left(struct kmem_cache *s, void *p)
193 {
194 	if (kmem_cache_debug_flags(s, SLAB_RED_ZONE))
195 		p += s->red_left_pad;
196 
197 	return p;
198 }
199 
200 static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
201 {
202 #ifdef CONFIG_SLUB_CPU_PARTIAL
203 	return !kmem_cache_debug(s);
204 #else
205 	return false;
206 #endif
207 }
208 
209 /*
210  * Issues still to be resolved:
211  *
212  * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
213  *
214  * - Variable sizing of the per node arrays
215  */
216 
217 /* Enable to log cmpxchg failures */
218 #undef SLUB_DEBUG_CMPXCHG
219 
220 /*
221  * Minimum number of partial slabs. These will be left on the partial
222  * lists even if they are empty. kmem_cache_shrink may reclaim them.
223  */
224 #define MIN_PARTIAL 5
225 
226 /*
227  * Maximum number of desirable partial slabs.
228  * The existence of more partial slabs makes kmem_cache_shrink
229  * sort the partial list by the number of objects in use.
230  */
231 #define MAX_PARTIAL 10
232 
233 #define DEBUG_DEFAULT_FLAGS (SLAB_CONSISTENCY_CHECKS | SLAB_RED_ZONE | \
234 				SLAB_POISON | SLAB_STORE_USER)
235 
236 /*
237  * These debug flags cannot use CMPXCHG because there might be consistency
238  * issues when checking or reading debug information
239  */
240 #define SLAB_NO_CMPXCHG (SLAB_CONSISTENCY_CHECKS | SLAB_STORE_USER | \
241 				SLAB_TRACE)
242 
243 
244 /*
245  * Debugging flags that require metadata to be stored in the slab.  These get
246  * disabled when slub_debug=O is used and a cache's min order increases with
247  * metadata.
248  */
249 #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
250 
251 #define OO_SHIFT	16
252 #define OO_MASK		((1 << OO_SHIFT) - 1)
253 #define MAX_OBJS_PER_PAGE	32767 /* since slab.objects is u15 */
254 
255 /* Internal SLUB flags */
256 /* Poison object */
257 #define __OBJECT_POISON		((slab_flags_t __force)0x80000000U)
258 /* Use cmpxchg_double */
259 #define __CMPXCHG_DOUBLE	((slab_flags_t __force)0x40000000U)
260 
261 /*
262  * Tracking user of a slab.
263  */
264 #define TRACK_ADDRS_COUNT 16
265 struct track {
266 	unsigned long addr;	/* Called from address */
267 #ifdef CONFIG_STACKTRACE
268 	unsigned long addrs[TRACK_ADDRS_COUNT];	/* Called from address */
269 #endif
270 	int cpu;		/* Was running on cpu */
271 	int pid;		/* Pid context */
272 	unsigned long when;	/* When did the operation occur */
273 };
274 
275 enum track_item { TRACK_ALLOC, TRACK_FREE };
276 
277 #ifdef CONFIG_SYSFS
278 static int sysfs_slab_add(struct kmem_cache *);
279 static int sysfs_slab_alias(struct kmem_cache *, const char *);
280 #else
281 static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
282 static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
283 							{ return 0; }
284 #endif
285 
286 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
287 static void debugfs_slab_add(struct kmem_cache *);
288 #else
289 static inline void debugfs_slab_add(struct kmem_cache *s) { }
290 #endif
291 
292 static inline void stat(const struct kmem_cache *s, enum stat_item si)
293 {
294 #ifdef CONFIG_SLUB_STATS
295 	/*
296 	 * The rmw is racy on a preemptible kernel but this is acceptable, so
297 	 * avoid this_cpu_add()'s irq-disable overhead.
298 	 */
299 	raw_cpu_inc(s->cpu_slab->stat[si]);
300 #endif
301 }
302 
303 /*
304  * Tracks for which NUMA nodes we have kmem_cache_nodes allocated.
305  * Corresponds to node_state[N_NORMAL_MEMORY], but can temporarily
306  * differ during memory hotplug/hotremove operations.
307  * Protected by slab_mutex.
308  */
309 static nodemask_t slab_nodes;
310 
311 /********************************************************************
312  * 			Core slab cache functions
313  *******************************************************************/
314 
315 /*
316  * Returns freelist pointer (ptr). With hardening, this is obfuscated
317  * with an XOR of the address where the pointer is held and a per-cache
318  * random number.
319  */
320 static inline void *freelist_ptr(const struct kmem_cache *s, void *ptr,
321 				 unsigned long ptr_addr)
322 {
323 #ifdef CONFIG_SLAB_FREELIST_HARDENED
324 	/*
325 	 * When CONFIG_KASAN_SW/HW_TAGS is enabled, ptr_addr might be tagged.
326 	 * Normally, this doesn't cause any issues, as both set_freepointer()
327 	 * and get_freepointer() are called with a pointer with the same tag.
328 	 * However, there are some issues with CONFIG_SLUB_DEBUG code. For
329 	 * example, when __free_slub() iterates over objects in a cache, it
330 	 * passes untagged pointers to check_object(). check_object() in turns
331 	 * calls get_freepointer() with an untagged pointer, which causes the
332 	 * freepointer to be restored incorrectly.
333 	 */
334 	return (void *)((unsigned long)ptr ^ s->random ^
335 			swab((unsigned long)kasan_reset_tag((void *)ptr_addr)));
336 #else
337 	return ptr;
338 #endif
339 }
340 
341 /* Returns the freelist pointer recorded at location ptr_addr. */
342 static inline void *freelist_dereference(const struct kmem_cache *s,
343 					 void *ptr_addr)
344 {
345 	return freelist_ptr(s, (void *)*(unsigned long *)(ptr_addr),
346 			    (unsigned long)ptr_addr);
347 }
348 
349 static inline void *get_freepointer(struct kmem_cache *s, void *object)
350 {
351 	object = kasan_reset_tag(object);
352 	return freelist_dereference(s, object + s->offset);
353 }
354 
355 static void prefetch_freepointer(const struct kmem_cache *s, void *object)
356 {
357 	prefetchw(object + s->offset);
358 }
359 
360 static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
361 {
362 	unsigned long freepointer_addr;
363 	void *p;
364 
365 	if (!debug_pagealloc_enabled_static())
366 		return get_freepointer(s, object);
367 
368 	object = kasan_reset_tag(object);
369 	freepointer_addr = (unsigned long)object + s->offset;
370 	copy_from_kernel_nofault(&p, (void **)freepointer_addr, sizeof(p));
371 	return freelist_ptr(s, p, freepointer_addr);
372 }
373 
374 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
375 {
376 	unsigned long freeptr_addr = (unsigned long)object + s->offset;
377 
378 #ifdef CONFIG_SLAB_FREELIST_HARDENED
379 	BUG_ON(object == fp); /* naive detection of double free or corruption */
380 #endif
381 
382 	freeptr_addr = (unsigned long)kasan_reset_tag((void *)freeptr_addr);
383 	*(void **)freeptr_addr = freelist_ptr(s, fp, freeptr_addr);
384 }
385 
386 /* Loop over all objects in a slab */
387 #define for_each_object(__p, __s, __addr, __objects) \
388 	for (__p = fixup_red_left(__s, __addr); \
389 		__p < (__addr) + (__objects) * (__s)->size; \
390 		__p += (__s)->size)
391 
392 static inline unsigned int order_objects(unsigned int order, unsigned int size)
393 {
394 	return ((unsigned int)PAGE_SIZE << order) / size;
395 }
396 
397 static inline struct kmem_cache_order_objects oo_make(unsigned int order,
398 		unsigned int size)
399 {
400 	struct kmem_cache_order_objects x = {
401 		(order << OO_SHIFT) + order_objects(order, size)
402 	};
403 
404 	return x;
405 }
406 
407 static inline unsigned int oo_order(struct kmem_cache_order_objects x)
408 {
409 	return x.x >> OO_SHIFT;
410 }
411 
412 static inline unsigned int oo_objects(struct kmem_cache_order_objects x)
413 {
414 	return x.x & OO_MASK;
415 }
416 
417 #ifdef CONFIG_SLUB_CPU_PARTIAL
418 static void slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects)
419 {
420 	unsigned int nr_slabs;
421 
422 	s->cpu_partial = nr_objects;
423 
424 	/*
425 	 * We take the number of objects but actually limit the number of
426 	 * slabs on the per cpu partial list, in order to limit excessive
427 	 * growth of the list. For simplicity we assume that the slabs will
428 	 * be half-full.
429 	 */
430 	nr_slabs = DIV_ROUND_UP(nr_objects * 2, oo_objects(s->oo));
431 	s->cpu_partial_slabs = nr_slabs;
432 }
433 #else
434 static inline void
435 slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects)
436 {
437 }
438 #endif /* CONFIG_SLUB_CPU_PARTIAL */
439 
440 /*
441  * Per slab locking using the pagelock
442  */
443 static __always_inline void __slab_lock(struct slab *slab)
444 {
445 	struct page *page = slab_page(slab);
446 
447 	VM_BUG_ON_PAGE(PageTail(page), page);
448 	bit_spin_lock(PG_locked, &page->flags);
449 }
450 
451 static __always_inline void __slab_unlock(struct slab *slab)
452 {
453 	struct page *page = slab_page(slab);
454 
455 	VM_BUG_ON_PAGE(PageTail(page), page);
456 	__bit_spin_unlock(PG_locked, &page->flags);
457 }
458 
459 static __always_inline void slab_lock(struct slab *slab, unsigned long *flags)
460 {
461 	if (IS_ENABLED(CONFIG_PREEMPT_RT))
462 		local_irq_save(*flags);
463 	__slab_lock(slab);
464 }
465 
466 static __always_inline void slab_unlock(struct slab *slab, unsigned long *flags)
467 {
468 	__slab_unlock(slab);
469 	if (IS_ENABLED(CONFIG_PREEMPT_RT))
470 		local_irq_restore(*flags);
471 }
472 
473 /*
474  * Interrupts must be disabled (for the fallback code to work right), typically
475  * by an _irqsave() lock variant. Except on PREEMPT_RT where locks are different
476  * so we disable interrupts as part of slab_[un]lock().
477  */
478 static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct slab *slab,
479 		void *freelist_old, unsigned long counters_old,
480 		void *freelist_new, unsigned long counters_new,
481 		const char *n)
482 {
483 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
484 		lockdep_assert_irqs_disabled();
485 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
486     defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
487 	if (s->flags & __CMPXCHG_DOUBLE) {
488 		if (cmpxchg_double(&slab->freelist, &slab->counters,
489 				   freelist_old, counters_old,
490 				   freelist_new, counters_new))
491 			return true;
492 	} else
493 #endif
494 	{
495 		/* init to 0 to prevent spurious warnings */
496 		unsigned long flags = 0;
497 
498 		slab_lock(slab, &flags);
499 		if (slab->freelist == freelist_old &&
500 					slab->counters == counters_old) {
501 			slab->freelist = freelist_new;
502 			slab->counters = counters_new;
503 			slab_unlock(slab, &flags);
504 			return true;
505 		}
506 		slab_unlock(slab, &flags);
507 	}
508 
509 	cpu_relax();
510 	stat(s, CMPXCHG_DOUBLE_FAIL);
511 
512 #ifdef SLUB_DEBUG_CMPXCHG
513 	pr_info("%s %s: cmpxchg double redo ", n, s->name);
514 #endif
515 
516 	return false;
517 }
518 
519 static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct slab *slab,
520 		void *freelist_old, unsigned long counters_old,
521 		void *freelist_new, unsigned long counters_new,
522 		const char *n)
523 {
524 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
525     defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
526 	if (s->flags & __CMPXCHG_DOUBLE) {
527 		if (cmpxchg_double(&slab->freelist, &slab->counters,
528 				   freelist_old, counters_old,
529 				   freelist_new, counters_new))
530 			return true;
531 	} else
532 #endif
533 	{
534 		unsigned long flags;
535 
536 		local_irq_save(flags);
537 		__slab_lock(slab);
538 		if (slab->freelist == freelist_old &&
539 					slab->counters == counters_old) {
540 			slab->freelist = freelist_new;
541 			slab->counters = counters_new;
542 			__slab_unlock(slab);
543 			local_irq_restore(flags);
544 			return true;
545 		}
546 		__slab_unlock(slab);
547 		local_irq_restore(flags);
548 	}
549 
550 	cpu_relax();
551 	stat(s, CMPXCHG_DOUBLE_FAIL);
552 
553 #ifdef SLUB_DEBUG_CMPXCHG
554 	pr_info("%s %s: cmpxchg double redo ", n, s->name);
555 #endif
556 
557 	return false;
558 }
559 
560 #ifdef CONFIG_SLUB_DEBUG
561 static unsigned long object_map[BITS_TO_LONGS(MAX_OBJS_PER_PAGE)];
562 static DEFINE_RAW_SPINLOCK(object_map_lock);
563 
564 static void __fill_map(unsigned long *obj_map, struct kmem_cache *s,
565 		       struct slab *slab)
566 {
567 	void *addr = slab_address(slab);
568 	void *p;
569 
570 	bitmap_zero(obj_map, slab->objects);
571 
572 	for (p = slab->freelist; p; p = get_freepointer(s, p))
573 		set_bit(__obj_to_index(s, addr, p), obj_map);
574 }
575 
576 #if IS_ENABLED(CONFIG_KUNIT)
577 static bool slab_add_kunit_errors(void)
578 {
579 	struct kunit_resource *resource;
580 
581 	if (likely(!current->kunit_test))
582 		return false;
583 
584 	resource = kunit_find_named_resource(current->kunit_test, "slab_errors");
585 	if (!resource)
586 		return false;
587 
588 	(*(int *)resource->data)++;
589 	kunit_put_resource(resource);
590 	return true;
591 }
592 #else
593 static inline bool slab_add_kunit_errors(void) { return false; }
594 #endif
595 
596 /*
597  * Determine a map of objects in use in a slab.
598  *
599  * Node listlock must be held to guarantee that the slab does
600  * not vanish from under us.
601  */
602 static unsigned long *get_map(struct kmem_cache *s, struct slab *slab)
603 	__acquires(&object_map_lock)
604 {
605 	VM_BUG_ON(!irqs_disabled());
606 
607 	raw_spin_lock(&object_map_lock);
608 
609 	__fill_map(object_map, s, slab);
610 
611 	return object_map;
612 }
613 
614 static void put_map(unsigned long *map) __releases(&object_map_lock)
615 {
616 	VM_BUG_ON(map != object_map);
617 	raw_spin_unlock(&object_map_lock);
618 }
619 
620 static inline unsigned int size_from_object(struct kmem_cache *s)
621 {
622 	if (s->flags & SLAB_RED_ZONE)
623 		return s->size - s->red_left_pad;
624 
625 	return s->size;
626 }
627 
628 static inline void *restore_red_left(struct kmem_cache *s, void *p)
629 {
630 	if (s->flags & SLAB_RED_ZONE)
631 		p -= s->red_left_pad;
632 
633 	return p;
634 }
635 
636 /*
637  * Debug settings:
638  */
639 #if defined(CONFIG_SLUB_DEBUG_ON)
640 static slab_flags_t slub_debug = DEBUG_DEFAULT_FLAGS;
641 #else
642 static slab_flags_t slub_debug;
643 #endif
644 
645 static char *slub_debug_string;
646 static int disable_higher_order_debug;
647 
648 /*
649  * slub is about to manipulate internal object metadata.  This memory lies
650  * outside the range of the allocated object, so accessing it would normally
651  * be reported by kasan as a bounds error.  metadata_access_enable() is used
652  * to tell kasan that these accesses are OK.
653  */
654 static inline void metadata_access_enable(void)
655 {
656 	kasan_disable_current();
657 }
658 
659 static inline void metadata_access_disable(void)
660 {
661 	kasan_enable_current();
662 }
663 
664 /*
665  * Object debugging
666  */
667 
668 /* Verify that a pointer has an address that is valid within a slab page */
669 static inline int check_valid_pointer(struct kmem_cache *s,
670 				struct slab *slab, void *object)
671 {
672 	void *base;
673 
674 	if (!object)
675 		return 1;
676 
677 	base = slab_address(slab);
678 	object = kasan_reset_tag(object);
679 	object = restore_red_left(s, object);
680 	if (object < base || object >= base + slab->objects * s->size ||
681 		(object - base) % s->size) {
682 		return 0;
683 	}
684 
685 	return 1;
686 }
687 
688 static void print_section(char *level, char *text, u8 *addr,
689 			  unsigned int length)
690 {
691 	metadata_access_enable();
692 	print_hex_dump(level, text, DUMP_PREFIX_ADDRESS,
693 			16, 1, kasan_reset_tag((void *)addr), length, 1);
694 	metadata_access_disable();
695 }
696 
697 /*
698  * See comment in calculate_sizes().
699  */
700 static inline bool freeptr_outside_object(struct kmem_cache *s)
701 {
702 	return s->offset >= s->inuse;
703 }
704 
705 /*
706  * Return offset of the end of info block which is inuse + free pointer if
707  * not overlapping with object.
708  */
709 static inline unsigned int get_info_end(struct kmem_cache *s)
710 {
711 	if (freeptr_outside_object(s))
712 		return s->inuse + sizeof(void *);
713 	else
714 		return s->inuse;
715 }
716 
717 static struct track *get_track(struct kmem_cache *s, void *object,
718 	enum track_item alloc)
719 {
720 	struct track *p;
721 
722 	p = object + get_info_end(s);
723 
724 	return kasan_reset_tag(p + alloc);
725 }
726 
727 static void set_track(struct kmem_cache *s, void *object,
728 			enum track_item alloc, unsigned long addr)
729 {
730 	struct track *p = get_track(s, object, alloc);
731 
732 	if (addr) {
733 #ifdef CONFIG_STACKTRACE
734 		unsigned int nr_entries;
735 
736 		metadata_access_enable();
737 		nr_entries = stack_trace_save(kasan_reset_tag(p->addrs),
738 					      TRACK_ADDRS_COUNT, 3);
739 		metadata_access_disable();
740 
741 		if (nr_entries < TRACK_ADDRS_COUNT)
742 			p->addrs[nr_entries] = 0;
743 #endif
744 		p->addr = addr;
745 		p->cpu = smp_processor_id();
746 		p->pid = current->pid;
747 		p->when = jiffies;
748 	} else {
749 		memset(p, 0, sizeof(struct track));
750 	}
751 }
752 
753 static void init_tracking(struct kmem_cache *s, void *object)
754 {
755 	if (!(s->flags & SLAB_STORE_USER))
756 		return;
757 
758 	set_track(s, object, TRACK_FREE, 0UL);
759 	set_track(s, object, TRACK_ALLOC, 0UL);
760 }
761 
762 static void print_track(const char *s, struct track *t, unsigned long pr_time)
763 {
764 	if (!t->addr)
765 		return;
766 
767 	pr_err("%s in %pS age=%lu cpu=%u pid=%d\n",
768 	       s, (void *)t->addr, pr_time - t->when, t->cpu, t->pid);
769 #ifdef CONFIG_STACKTRACE
770 	{
771 		int i;
772 		for (i = 0; i < TRACK_ADDRS_COUNT; i++)
773 			if (t->addrs[i])
774 				pr_err("\t%pS\n", (void *)t->addrs[i]);
775 			else
776 				break;
777 	}
778 #endif
779 }
780 
781 void print_tracking(struct kmem_cache *s, void *object)
782 {
783 	unsigned long pr_time = jiffies;
784 	if (!(s->flags & SLAB_STORE_USER))
785 		return;
786 
787 	print_track("Allocated", get_track(s, object, TRACK_ALLOC), pr_time);
788 	print_track("Freed", get_track(s, object, TRACK_FREE), pr_time);
789 }
790 
791 static void print_slab_info(const struct slab *slab)
792 {
793 	struct folio *folio = (struct folio *)slab_folio(slab);
794 
795 	pr_err("Slab 0x%p objects=%u used=%u fp=0x%p flags=%pGp\n",
796 	       slab, slab->objects, slab->inuse, slab->freelist,
797 	       folio_flags(folio, 0));
798 }
799 
800 static void slab_bug(struct kmem_cache *s, char *fmt, ...)
801 {
802 	struct va_format vaf;
803 	va_list args;
804 
805 	va_start(args, fmt);
806 	vaf.fmt = fmt;
807 	vaf.va = &args;
808 	pr_err("=============================================================================\n");
809 	pr_err("BUG %s (%s): %pV\n", s->name, print_tainted(), &vaf);
810 	pr_err("-----------------------------------------------------------------------------\n\n");
811 	va_end(args);
812 }
813 
814 __printf(2, 3)
815 static void slab_fix(struct kmem_cache *s, char *fmt, ...)
816 {
817 	struct va_format vaf;
818 	va_list args;
819 
820 	if (slab_add_kunit_errors())
821 		return;
822 
823 	va_start(args, fmt);
824 	vaf.fmt = fmt;
825 	vaf.va = &args;
826 	pr_err("FIX %s: %pV\n", s->name, &vaf);
827 	va_end(args);
828 }
829 
830 static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p)
831 {
832 	unsigned int off;	/* Offset of last byte */
833 	u8 *addr = slab_address(slab);
834 
835 	print_tracking(s, p);
836 
837 	print_slab_info(slab);
838 
839 	pr_err("Object 0x%p @offset=%tu fp=0x%p\n\n",
840 	       p, p - addr, get_freepointer(s, p));
841 
842 	if (s->flags & SLAB_RED_ZONE)
843 		print_section(KERN_ERR, "Redzone  ", p - s->red_left_pad,
844 			      s->red_left_pad);
845 	else if (p > addr + 16)
846 		print_section(KERN_ERR, "Bytes b4 ", p - 16, 16);
847 
848 	print_section(KERN_ERR,         "Object   ", p,
849 		      min_t(unsigned int, s->object_size, PAGE_SIZE));
850 	if (s->flags & SLAB_RED_ZONE)
851 		print_section(KERN_ERR, "Redzone  ", p + s->object_size,
852 			s->inuse - s->object_size);
853 
854 	off = get_info_end(s);
855 
856 	if (s->flags & SLAB_STORE_USER)
857 		off += 2 * sizeof(struct track);
858 
859 	off += kasan_metadata_size(s);
860 
861 	if (off != size_from_object(s))
862 		/* Beginning of the filler is the free pointer */
863 		print_section(KERN_ERR, "Padding  ", p + off,
864 			      size_from_object(s) - off);
865 
866 	dump_stack();
867 }
868 
869 static void object_err(struct kmem_cache *s, struct slab *slab,
870 			u8 *object, char *reason)
871 {
872 	if (slab_add_kunit_errors())
873 		return;
874 
875 	slab_bug(s, "%s", reason);
876 	print_trailer(s, slab, object);
877 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
878 }
879 
880 static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab,
881 			       void **freelist, void *nextfree)
882 {
883 	if ((s->flags & SLAB_CONSISTENCY_CHECKS) &&
884 	    !check_valid_pointer(s, slab, nextfree) && freelist) {
885 		object_err(s, slab, *freelist, "Freechain corrupt");
886 		*freelist = NULL;
887 		slab_fix(s, "Isolate corrupted freechain");
888 		return true;
889 	}
890 
891 	return false;
892 }
893 
894 static __printf(3, 4) void slab_err(struct kmem_cache *s, struct slab *slab,
895 			const char *fmt, ...)
896 {
897 	va_list args;
898 	char buf[100];
899 
900 	if (slab_add_kunit_errors())
901 		return;
902 
903 	va_start(args, fmt);
904 	vsnprintf(buf, sizeof(buf), fmt, args);
905 	va_end(args);
906 	slab_bug(s, "%s", buf);
907 	print_slab_info(slab);
908 	dump_stack();
909 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
910 }
911 
912 static void init_object(struct kmem_cache *s, void *object, u8 val)
913 {
914 	u8 *p = kasan_reset_tag(object);
915 
916 	if (s->flags & SLAB_RED_ZONE)
917 		memset(p - s->red_left_pad, val, s->red_left_pad);
918 
919 	if (s->flags & __OBJECT_POISON) {
920 		memset(p, POISON_FREE, s->object_size - 1);
921 		p[s->object_size - 1] = POISON_END;
922 	}
923 
924 	if (s->flags & SLAB_RED_ZONE)
925 		memset(p + s->object_size, val, s->inuse - s->object_size);
926 }
927 
928 static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
929 						void *from, void *to)
930 {
931 	slab_fix(s, "Restoring %s 0x%p-0x%p=0x%x", message, from, to - 1, data);
932 	memset(from, data, to - from);
933 }
934 
935 static int check_bytes_and_report(struct kmem_cache *s, struct slab *slab,
936 			u8 *object, char *what,
937 			u8 *start, unsigned int value, unsigned int bytes)
938 {
939 	u8 *fault;
940 	u8 *end;
941 	u8 *addr = slab_address(slab);
942 
943 	metadata_access_enable();
944 	fault = memchr_inv(kasan_reset_tag(start), value, bytes);
945 	metadata_access_disable();
946 	if (!fault)
947 		return 1;
948 
949 	end = start + bytes;
950 	while (end > fault && end[-1] == value)
951 		end--;
952 
953 	if (slab_add_kunit_errors())
954 		goto skip_bug_print;
955 
956 	slab_bug(s, "%s overwritten", what);
957 	pr_err("0x%p-0x%p @offset=%tu. First byte 0x%x instead of 0x%x\n",
958 					fault, end - 1, fault - addr,
959 					fault[0], value);
960 	print_trailer(s, slab, object);
961 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
962 
963 skip_bug_print:
964 	restore_bytes(s, what, value, fault, end);
965 	return 0;
966 }
967 
968 /*
969  * Object layout:
970  *
971  * object address
972  * 	Bytes of the object to be managed.
973  * 	If the freepointer may overlay the object then the free
974  *	pointer is at the middle of the object.
975  *
976  * 	Poisoning uses 0x6b (POISON_FREE) and the last byte is
977  * 	0xa5 (POISON_END)
978  *
979  * object + s->object_size
980  * 	Padding to reach word boundary. This is also used for Redzoning.
981  * 	Padding is extended by another word if Redzoning is enabled and
982  * 	object_size == inuse.
983  *
984  * 	We fill with 0xbb (RED_INACTIVE) for inactive objects and with
985  * 	0xcc (RED_ACTIVE) for objects in use.
986  *
987  * object + s->inuse
988  * 	Meta data starts here.
989  *
990  * 	A. Free pointer (if we cannot overwrite object on free)
991  * 	B. Tracking data for SLAB_STORE_USER
992  *	C. Padding to reach required alignment boundary or at minimum
993  * 		one word if debugging is on to be able to detect writes
994  * 		before the word boundary.
995  *
996  *	Padding is done using 0x5a (POISON_INUSE)
997  *
998  * object + s->size
999  * 	Nothing is used beyond s->size.
1000  *
1001  * If slabcaches are merged then the object_size and inuse boundaries are mostly
1002  * ignored. And therefore no slab options that rely on these boundaries
1003  * may be used with merged slabcaches.
1004  */
1005 
1006 static int check_pad_bytes(struct kmem_cache *s, struct slab *slab, u8 *p)
1007 {
1008 	unsigned long off = get_info_end(s);	/* The end of info */
1009 
1010 	if (s->flags & SLAB_STORE_USER)
1011 		/* We also have user information there */
1012 		off += 2 * sizeof(struct track);
1013 
1014 	off += kasan_metadata_size(s);
1015 
1016 	if (size_from_object(s) == off)
1017 		return 1;
1018 
1019 	return check_bytes_and_report(s, slab, p, "Object padding",
1020 			p + off, POISON_INUSE, size_from_object(s) - off);
1021 }
1022 
1023 /* Check the pad bytes at the end of a slab page */
1024 static int slab_pad_check(struct kmem_cache *s, struct slab *slab)
1025 {
1026 	u8 *start;
1027 	u8 *fault;
1028 	u8 *end;
1029 	u8 *pad;
1030 	int length;
1031 	int remainder;
1032 
1033 	if (!(s->flags & SLAB_POISON))
1034 		return 1;
1035 
1036 	start = slab_address(slab);
1037 	length = slab_size(slab);
1038 	end = start + length;
1039 	remainder = length % s->size;
1040 	if (!remainder)
1041 		return 1;
1042 
1043 	pad = end - remainder;
1044 	metadata_access_enable();
1045 	fault = memchr_inv(kasan_reset_tag(pad), POISON_INUSE, remainder);
1046 	metadata_access_disable();
1047 	if (!fault)
1048 		return 1;
1049 	while (end > fault && end[-1] == POISON_INUSE)
1050 		end--;
1051 
1052 	slab_err(s, slab, "Padding overwritten. 0x%p-0x%p @offset=%tu",
1053 			fault, end - 1, fault - start);
1054 	print_section(KERN_ERR, "Padding ", pad, remainder);
1055 
1056 	restore_bytes(s, "slab padding", POISON_INUSE, fault, end);
1057 	return 0;
1058 }
1059 
1060 static int check_object(struct kmem_cache *s, struct slab *slab,
1061 					void *object, u8 val)
1062 {
1063 	u8 *p = object;
1064 	u8 *endobject = object + s->object_size;
1065 
1066 	if (s->flags & SLAB_RED_ZONE) {
1067 		if (!check_bytes_and_report(s, slab, object, "Left Redzone",
1068 			object - s->red_left_pad, val, s->red_left_pad))
1069 			return 0;
1070 
1071 		if (!check_bytes_and_report(s, slab, object, "Right Redzone",
1072 			endobject, val, s->inuse - s->object_size))
1073 			return 0;
1074 	} else {
1075 		if ((s->flags & SLAB_POISON) && s->object_size < s->inuse) {
1076 			check_bytes_and_report(s, slab, p, "Alignment padding",
1077 				endobject, POISON_INUSE,
1078 				s->inuse - s->object_size);
1079 		}
1080 	}
1081 
1082 	if (s->flags & SLAB_POISON) {
1083 		if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) &&
1084 			(!check_bytes_and_report(s, slab, p, "Poison", p,
1085 					POISON_FREE, s->object_size - 1) ||
1086 			 !check_bytes_and_report(s, slab, p, "End Poison",
1087 				p + s->object_size - 1, POISON_END, 1)))
1088 			return 0;
1089 		/*
1090 		 * check_pad_bytes cleans up on its own.
1091 		 */
1092 		check_pad_bytes(s, slab, p);
1093 	}
1094 
1095 	if (!freeptr_outside_object(s) && val == SLUB_RED_ACTIVE)
1096 		/*
1097 		 * Object and freepointer overlap. Cannot check
1098 		 * freepointer while object is allocated.
1099 		 */
1100 		return 1;
1101 
1102 	/* Check free pointer validity */
1103 	if (!check_valid_pointer(s, slab, get_freepointer(s, p))) {
1104 		object_err(s, slab, p, "Freepointer corrupt");
1105 		/*
1106 		 * No choice but to zap it and thus lose the remainder
1107 		 * of the free objects in this slab. May cause
1108 		 * another error because the object count is now wrong.
1109 		 */
1110 		set_freepointer(s, p, NULL);
1111 		return 0;
1112 	}
1113 	return 1;
1114 }
1115 
1116 static int check_slab(struct kmem_cache *s, struct slab *slab)
1117 {
1118 	int maxobj;
1119 
1120 	if (!folio_test_slab(slab_folio(slab))) {
1121 		slab_err(s, slab, "Not a valid slab page");
1122 		return 0;
1123 	}
1124 
1125 	maxobj = order_objects(slab_order(slab), s->size);
1126 	if (slab->objects > maxobj) {
1127 		slab_err(s, slab, "objects %u > max %u",
1128 			slab->objects, maxobj);
1129 		return 0;
1130 	}
1131 	if (slab->inuse > slab->objects) {
1132 		slab_err(s, slab, "inuse %u > max %u",
1133 			slab->inuse, slab->objects);
1134 		return 0;
1135 	}
1136 	/* Slab_pad_check fixes things up after itself */
1137 	slab_pad_check(s, slab);
1138 	return 1;
1139 }
1140 
1141 /*
1142  * Determine if a certain object in a slab is on the freelist. Must hold the
1143  * slab lock to guarantee that the chains are in a consistent state.
1144  */
1145 static int on_freelist(struct kmem_cache *s, struct slab *slab, void *search)
1146 {
1147 	int nr = 0;
1148 	void *fp;
1149 	void *object = NULL;
1150 	int max_objects;
1151 
1152 	fp = slab->freelist;
1153 	while (fp && nr <= slab->objects) {
1154 		if (fp == search)
1155 			return 1;
1156 		if (!check_valid_pointer(s, slab, fp)) {
1157 			if (object) {
1158 				object_err(s, slab, object,
1159 					"Freechain corrupt");
1160 				set_freepointer(s, object, NULL);
1161 			} else {
1162 				slab_err(s, slab, "Freepointer corrupt");
1163 				slab->freelist = NULL;
1164 				slab->inuse = slab->objects;
1165 				slab_fix(s, "Freelist cleared");
1166 				return 0;
1167 			}
1168 			break;
1169 		}
1170 		object = fp;
1171 		fp = get_freepointer(s, object);
1172 		nr++;
1173 	}
1174 
1175 	max_objects = order_objects(slab_order(slab), s->size);
1176 	if (max_objects > MAX_OBJS_PER_PAGE)
1177 		max_objects = MAX_OBJS_PER_PAGE;
1178 
1179 	if (slab->objects != max_objects) {
1180 		slab_err(s, slab, "Wrong number of objects. Found %d but should be %d",
1181 			 slab->objects, max_objects);
1182 		slab->objects = max_objects;
1183 		slab_fix(s, "Number of objects adjusted");
1184 	}
1185 	if (slab->inuse != slab->objects - nr) {
1186 		slab_err(s, slab, "Wrong object count. Counter is %d but counted were %d",
1187 			 slab->inuse, slab->objects - nr);
1188 		slab->inuse = slab->objects - nr;
1189 		slab_fix(s, "Object count adjusted");
1190 	}
1191 	return search == NULL;
1192 }
1193 
1194 static void trace(struct kmem_cache *s, struct slab *slab, void *object,
1195 								int alloc)
1196 {
1197 	if (s->flags & SLAB_TRACE) {
1198 		pr_info("TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
1199 			s->name,
1200 			alloc ? "alloc" : "free",
1201 			object, slab->inuse,
1202 			slab->freelist);
1203 
1204 		if (!alloc)
1205 			print_section(KERN_INFO, "Object ", (void *)object,
1206 					s->object_size);
1207 
1208 		dump_stack();
1209 	}
1210 }
1211 
1212 /*
1213  * Tracking of fully allocated slabs for debugging purposes.
1214  */
1215 static void add_full(struct kmem_cache *s,
1216 	struct kmem_cache_node *n, struct slab *slab)
1217 {
1218 	if (!(s->flags & SLAB_STORE_USER))
1219 		return;
1220 
1221 	lockdep_assert_held(&n->list_lock);
1222 	list_add(&slab->slab_list, &n->full);
1223 }
1224 
1225 static void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, struct slab *slab)
1226 {
1227 	if (!(s->flags & SLAB_STORE_USER))
1228 		return;
1229 
1230 	lockdep_assert_held(&n->list_lock);
1231 	list_del(&slab->slab_list);
1232 }
1233 
1234 /* Tracking of the number of slabs for debugging purposes */
1235 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
1236 {
1237 	struct kmem_cache_node *n = get_node(s, node);
1238 
1239 	return atomic_long_read(&n->nr_slabs);
1240 }
1241 
1242 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
1243 {
1244 	return atomic_long_read(&n->nr_slabs);
1245 }
1246 
1247 static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
1248 {
1249 	struct kmem_cache_node *n = get_node(s, node);
1250 
1251 	/*
1252 	 * May be called early in order to allocate a slab for the
1253 	 * kmem_cache_node structure. Solve the chicken-egg
1254 	 * dilemma by deferring the increment of the count during
1255 	 * bootstrap (see early_kmem_cache_node_alloc).
1256 	 */
1257 	if (likely(n)) {
1258 		atomic_long_inc(&n->nr_slabs);
1259 		atomic_long_add(objects, &n->total_objects);
1260 	}
1261 }
1262 static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
1263 {
1264 	struct kmem_cache_node *n = get_node(s, node);
1265 
1266 	atomic_long_dec(&n->nr_slabs);
1267 	atomic_long_sub(objects, &n->total_objects);
1268 }
1269 
1270 /* Object debug checks for alloc/free paths */
1271 static void setup_object_debug(struct kmem_cache *s, struct slab *slab,
1272 								void *object)
1273 {
1274 	if (!kmem_cache_debug_flags(s, SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))
1275 		return;
1276 
1277 	init_object(s, object, SLUB_RED_INACTIVE);
1278 	init_tracking(s, object);
1279 }
1280 
1281 static
1282 void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr)
1283 {
1284 	if (!kmem_cache_debug_flags(s, SLAB_POISON))
1285 		return;
1286 
1287 	metadata_access_enable();
1288 	memset(kasan_reset_tag(addr), POISON_INUSE, slab_size(slab));
1289 	metadata_access_disable();
1290 }
1291 
1292 static inline int alloc_consistency_checks(struct kmem_cache *s,
1293 					struct slab *slab, void *object)
1294 {
1295 	if (!check_slab(s, slab))
1296 		return 0;
1297 
1298 	if (!check_valid_pointer(s, slab, object)) {
1299 		object_err(s, slab, object, "Freelist Pointer check fails");
1300 		return 0;
1301 	}
1302 
1303 	if (!check_object(s, slab, object, SLUB_RED_INACTIVE))
1304 		return 0;
1305 
1306 	return 1;
1307 }
1308 
1309 static noinline int alloc_debug_processing(struct kmem_cache *s,
1310 					struct slab *slab,
1311 					void *object, unsigned long addr)
1312 {
1313 	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
1314 		if (!alloc_consistency_checks(s, slab, object))
1315 			goto bad;
1316 	}
1317 
1318 	/* Success perform special debug activities for allocs */
1319 	if (s->flags & SLAB_STORE_USER)
1320 		set_track(s, object, TRACK_ALLOC, addr);
1321 	trace(s, slab, object, 1);
1322 	init_object(s, object, SLUB_RED_ACTIVE);
1323 	return 1;
1324 
1325 bad:
1326 	if (folio_test_slab(slab_folio(slab))) {
1327 		/*
1328 		 * If this is a slab page then lets do the best we can
1329 		 * to avoid issues in the future. Marking all objects
1330 		 * as used avoids touching the remaining objects.
1331 		 */
1332 		slab_fix(s, "Marking all objects used");
1333 		slab->inuse = slab->objects;
1334 		slab->freelist = NULL;
1335 	}
1336 	return 0;
1337 }
1338 
1339 static inline int free_consistency_checks(struct kmem_cache *s,
1340 		struct slab *slab, void *object, unsigned long addr)
1341 {
1342 	if (!check_valid_pointer(s, slab, object)) {
1343 		slab_err(s, slab, "Invalid object pointer 0x%p", object);
1344 		return 0;
1345 	}
1346 
1347 	if (on_freelist(s, slab, object)) {
1348 		object_err(s, slab, object, "Object already free");
1349 		return 0;
1350 	}
1351 
1352 	if (!check_object(s, slab, object, SLUB_RED_ACTIVE))
1353 		return 0;
1354 
1355 	if (unlikely(s != slab->slab_cache)) {
1356 		if (!folio_test_slab(slab_folio(slab))) {
1357 			slab_err(s, slab, "Attempt to free object(0x%p) outside of slab",
1358 				 object);
1359 		} else if (!slab->slab_cache) {
1360 			pr_err("SLUB <none>: no slab for object 0x%p.\n",
1361 			       object);
1362 			dump_stack();
1363 		} else
1364 			object_err(s, slab, object,
1365 					"page slab pointer corrupt.");
1366 		return 0;
1367 	}
1368 	return 1;
1369 }
1370 
1371 /* Supports checking bulk free of a constructed freelist */
1372 static noinline int free_debug_processing(
1373 	struct kmem_cache *s, struct slab *slab,
1374 	void *head, void *tail, int bulk_cnt,
1375 	unsigned long addr)
1376 {
1377 	struct kmem_cache_node *n = get_node(s, slab_nid(slab));
1378 	void *object = head;
1379 	int cnt = 0;
1380 	unsigned long flags, flags2;
1381 	int ret = 0;
1382 
1383 	spin_lock_irqsave(&n->list_lock, flags);
1384 	slab_lock(slab, &flags2);
1385 
1386 	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
1387 		if (!check_slab(s, slab))
1388 			goto out;
1389 	}
1390 
1391 next_object:
1392 	cnt++;
1393 
1394 	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
1395 		if (!free_consistency_checks(s, slab, object, addr))
1396 			goto out;
1397 	}
1398 
1399 	if (s->flags & SLAB_STORE_USER)
1400 		set_track(s, object, TRACK_FREE, addr);
1401 	trace(s, slab, object, 0);
1402 	/* Freepointer not overwritten by init_object(), SLAB_POISON moved it */
1403 	init_object(s, object, SLUB_RED_INACTIVE);
1404 
1405 	/* Reached end of constructed freelist yet? */
1406 	if (object != tail) {
1407 		object = get_freepointer(s, object);
1408 		goto next_object;
1409 	}
1410 	ret = 1;
1411 
1412 out:
1413 	if (cnt != bulk_cnt)
1414 		slab_err(s, slab, "Bulk freelist count(%d) invalid(%d)\n",
1415 			 bulk_cnt, cnt);
1416 
1417 	slab_unlock(slab, &flags2);
1418 	spin_unlock_irqrestore(&n->list_lock, flags);
1419 	if (!ret)
1420 		slab_fix(s, "Object at 0x%p not freed", object);
1421 	return ret;
1422 }
1423 
1424 /*
1425  * Parse a block of slub_debug options. Blocks are delimited by ';'
1426  *
1427  * @str:    start of block
1428  * @flags:  returns parsed flags, or DEBUG_DEFAULT_FLAGS if none specified
1429  * @slabs:  return start of list of slabs, or NULL when there's no list
1430  * @init:   assume this is initial parsing and not per-kmem-create parsing
1431  *
1432  * returns the start of next block if there's any, or NULL
1433  */
1434 static char *
1435 parse_slub_debug_flags(char *str, slab_flags_t *flags, char **slabs, bool init)
1436 {
1437 	bool higher_order_disable = false;
1438 
1439 	/* Skip any completely empty blocks */
1440 	while (*str && *str == ';')
1441 		str++;
1442 
1443 	if (*str == ',') {
1444 		/*
1445 		 * No options but restriction on slabs. This means full
1446 		 * debugging for slabs matching a pattern.
1447 		 */
1448 		*flags = DEBUG_DEFAULT_FLAGS;
1449 		goto check_slabs;
1450 	}
1451 	*flags = 0;
1452 
1453 	/* Determine which debug features should be switched on */
1454 	for (; *str && *str != ',' && *str != ';'; str++) {
1455 		switch (tolower(*str)) {
1456 		case '-':
1457 			*flags = 0;
1458 			break;
1459 		case 'f':
1460 			*flags |= SLAB_CONSISTENCY_CHECKS;
1461 			break;
1462 		case 'z':
1463 			*flags |= SLAB_RED_ZONE;
1464 			break;
1465 		case 'p':
1466 			*flags |= SLAB_POISON;
1467 			break;
1468 		case 'u':
1469 			*flags |= SLAB_STORE_USER;
1470 			break;
1471 		case 't':
1472 			*flags |= SLAB_TRACE;
1473 			break;
1474 		case 'a':
1475 			*flags |= SLAB_FAILSLAB;
1476 			break;
1477 		case 'o':
1478 			/*
1479 			 * Avoid enabling debugging on caches if its minimum
1480 			 * order would increase as a result.
1481 			 */
1482 			higher_order_disable = true;
1483 			break;
1484 		default:
1485 			if (init)
1486 				pr_err("slub_debug option '%c' unknown. skipped\n", *str);
1487 		}
1488 	}
1489 check_slabs:
1490 	if (*str == ',')
1491 		*slabs = ++str;
1492 	else
1493 		*slabs = NULL;
1494 
1495 	/* Skip over the slab list */
1496 	while (*str && *str != ';')
1497 		str++;
1498 
1499 	/* Skip any completely empty blocks */
1500 	while (*str && *str == ';')
1501 		str++;
1502 
1503 	if (init && higher_order_disable)
1504 		disable_higher_order_debug = 1;
1505 
1506 	if (*str)
1507 		return str;
1508 	else
1509 		return NULL;
1510 }
1511 
1512 static int __init setup_slub_debug(char *str)
1513 {
1514 	slab_flags_t flags;
1515 	slab_flags_t global_flags;
1516 	char *saved_str;
1517 	char *slab_list;
1518 	bool global_slub_debug_changed = false;
1519 	bool slab_list_specified = false;
1520 
1521 	global_flags = DEBUG_DEFAULT_FLAGS;
1522 	if (*str++ != '=' || !*str)
1523 		/*
1524 		 * No options specified. Switch on full debugging.
1525 		 */
1526 		goto out;
1527 
1528 	saved_str = str;
1529 	while (str) {
1530 		str = parse_slub_debug_flags(str, &flags, &slab_list, true);
1531 
1532 		if (!slab_list) {
1533 			global_flags = flags;
1534 			global_slub_debug_changed = true;
1535 		} else {
1536 			slab_list_specified = true;
1537 		}
1538 	}
1539 
1540 	/*
1541 	 * For backwards compatibility, a single list of flags with list of
1542 	 * slabs means debugging is only changed for those slabs, so the global
1543 	 * slub_debug should be unchanged (0 or DEBUG_DEFAULT_FLAGS, depending
1544 	 * on CONFIG_SLUB_DEBUG_ON). We can extended that to multiple lists as
1545 	 * long as there is no option specifying flags without a slab list.
1546 	 */
1547 	if (slab_list_specified) {
1548 		if (!global_slub_debug_changed)
1549 			global_flags = slub_debug;
1550 		slub_debug_string = saved_str;
1551 	}
1552 out:
1553 	slub_debug = global_flags;
1554 	if (slub_debug != 0 || slub_debug_string)
1555 		static_branch_enable(&slub_debug_enabled);
1556 	else
1557 		static_branch_disable(&slub_debug_enabled);
1558 	if ((static_branch_unlikely(&init_on_alloc) ||
1559 	     static_branch_unlikely(&init_on_free)) &&
1560 	    (slub_debug & SLAB_POISON))
1561 		pr_info("mem auto-init: SLAB_POISON will take precedence over init_on_alloc/init_on_free\n");
1562 	return 1;
1563 }
1564 
1565 __setup("slub_debug", setup_slub_debug);
1566 
1567 /*
1568  * kmem_cache_flags - apply debugging options to the cache
1569  * @object_size:	the size of an object without meta data
1570  * @flags:		flags to set
1571  * @name:		name of the cache
1572  *
1573  * Debug option(s) are applied to @flags. In addition to the debug
1574  * option(s), if a slab name (or multiple) is specified i.e.
1575  * slub_debug=<Debug-Options>,<slab name1>,<slab name2> ...
1576  * then only the select slabs will receive the debug option(s).
1577  */
1578 slab_flags_t kmem_cache_flags(unsigned int object_size,
1579 	slab_flags_t flags, const char *name)
1580 {
1581 	char *iter;
1582 	size_t len;
1583 	char *next_block;
1584 	slab_flags_t block_flags;
1585 	slab_flags_t slub_debug_local = slub_debug;
1586 
1587 	/*
1588 	 * If the slab cache is for debugging (e.g. kmemleak) then
1589 	 * don't store user (stack trace) information by default,
1590 	 * but let the user enable it via the command line below.
1591 	 */
1592 	if (flags & SLAB_NOLEAKTRACE)
1593 		slub_debug_local &= ~SLAB_STORE_USER;
1594 
1595 	len = strlen(name);
1596 	next_block = slub_debug_string;
1597 	/* Go through all blocks of debug options, see if any matches our slab's name */
1598 	while (next_block) {
1599 		next_block = parse_slub_debug_flags(next_block, &block_flags, &iter, false);
1600 		if (!iter)
1601 			continue;
1602 		/* Found a block that has a slab list, search it */
1603 		while (*iter) {
1604 			char *end, *glob;
1605 			size_t cmplen;
1606 
1607 			end = strchrnul(iter, ',');
1608 			if (next_block && next_block < end)
1609 				end = next_block - 1;
1610 
1611 			glob = strnchr(iter, end - iter, '*');
1612 			if (glob)
1613 				cmplen = glob - iter;
1614 			else
1615 				cmplen = max_t(size_t, len, (end - iter));
1616 
1617 			if (!strncmp(name, iter, cmplen)) {
1618 				flags |= block_flags;
1619 				return flags;
1620 			}
1621 
1622 			if (!*end || *end == ';')
1623 				break;
1624 			iter = end + 1;
1625 		}
1626 	}
1627 
1628 	return flags | slub_debug_local;
1629 }
1630 #else /* !CONFIG_SLUB_DEBUG */
1631 static inline void setup_object_debug(struct kmem_cache *s,
1632 			struct slab *slab, void *object) {}
1633 static inline
1634 void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr) {}
1635 
1636 static inline int alloc_debug_processing(struct kmem_cache *s,
1637 	struct slab *slab, void *object, unsigned long addr) { return 0; }
1638 
1639 static inline int free_debug_processing(
1640 	struct kmem_cache *s, struct slab *slab,
1641 	void *head, void *tail, int bulk_cnt,
1642 	unsigned long addr) { return 0; }
1643 
1644 static inline int slab_pad_check(struct kmem_cache *s, struct slab *slab)
1645 			{ return 1; }
1646 static inline int check_object(struct kmem_cache *s, struct slab *slab,
1647 			void *object, u8 val) { return 1; }
1648 static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
1649 					struct slab *slab) {}
1650 static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n,
1651 					struct slab *slab) {}
1652 slab_flags_t kmem_cache_flags(unsigned int object_size,
1653 	slab_flags_t flags, const char *name)
1654 {
1655 	return flags;
1656 }
1657 #define slub_debug 0
1658 
1659 #define disable_higher_order_debug 0
1660 
1661 static inline unsigned long slabs_node(struct kmem_cache *s, int node)
1662 							{ return 0; }
1663 static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
1664 							{ return 0; }
1665 static inline void inc_slabs_node(struct kmem_cache *s, int node,
1666 							int objects) {}
1667 static inline void dec_slabs_node(struct kmem_cache *s, int node,
1668 							int objects) {}
1669 
1670 static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab,
1671 			       void **freelist, void *nextfree)
1672 {
1673 	return false;
1674 }
1675 #endif /* CONFIG_SLUB_DEBUG */
1676 
1677 /*
1678  * Hooks for other subsystems that check memory allocations. In a typical
1679  * production configuration these hooks all should produce no code at all.
1680  */
1681 static inline void *kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
1682 {
1683 	ptr = kasan_kmalloc_large(ptr, size, flags);
1684 	/* As ptr might get tagged, call kmemleak hook after KASAN. */
1685 	kmemleak_alloc(ptr, size, 1, flags);
1686 	return ptr;
1687 }
1688 
1689 static __always_inline void kfree_hook(void *x)
1690 {
1691 	kmemleak_free(x);
1692 	kasan_kfree_large(x);
1693 }
1694 
1695 static __always_inline bool slab_free_hook(struct kmem_cache *s,
1696 						void *x, bool init)
1697 {
1698 	kmemleak_free_recursive(x, s->flags);
1699 
1700 	debug_check_no_locks_freed(x, s->object_size);
1701 
1702 	if (!(s->flags & SLAB_DEBUG_OBJECTS))
1703 		debug_check_no_obj_freed(x, s->object_size);
1704 
1705 	/* Use KCSAN to help debug racy use-after-free. */
1706 	if (!(s->flags & SLAB_TYPESAFE_BY_RCU))
1707 		__kcsan_check_access(x, s->object_size,
1708 				     KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT);
1709 
1710 	/*
1711 	 * As memory initialization might be integrated into KASAN,
1712 	 * kasan_slab_free and initialization memset's must be
1713 	 * kept together to avoid discrepancies in behavior.
1714 	 *
1715 	 * The initialization memset's clear the object and the metadata,
1716 	 * but don't touch the SLAB redzone.
1717 	 */
1718 	if (init) {
1719 		int rsize;
1720 
1721 		if (!kasan_has_integrated_init())
1722 			memset(kasan_reset_tag(x), 0, s->object_size);
1723 		rsize = (s->flags & SLAB_RED_ZONE) ? s->red_left_pad : 0;
1724 		memset((char *)kasan_reset_tag(x) + s->inuse, 0,
1725 		       s->size - s->inuse - rsize);
1726 	}
1727 	/* KASAN might put x into memory quarantine, delaying its reuse. */
1728 	return kasan_slab_free(s, x, init);
1729 }
1730 
1731 static inline bool slab_free_freelist_hook(struct kmem_cache *s,
1732 					   void **head, void **tail,
1733 					   int *cnt)
1734 {
1735 
1736 	void *object;
1737 	void *next = *head;
1738 	void *old_tail = *tail ? *tail : *head;
1739 
1740 	if (is_kfence_address(next)) {
1741 		slab_free_hook(s, next, false);
1742 		return true;
1743 	}
1744 
1745 	/* Head and tail of the reconstructed freelist */
1746 	*head = NULL;
1747 	*tail = NULL;
1748 
1749 	do {
1750 		object = next;
1751 		next = get_freepointer(s, object);
1752 
1753 		/* If object's reuse doesn't have to be delayed */
1754 		if (!slab_free_hook(s, object, slab_want_init_on_free(s))) {
1755 			/* Move object to the new freelist */
1756 			set_freepointer(s, object, *head);
1757 			*head = object;
1758 			if (!*tail)
1759 				*tail = object;
1760 		} else {
1761 			/*
1762 			 * Adjust the reconstructed freelist depth
1763 			 * accordingly if object's reuse is delayed.
1764 			 */
1765 			--(*cnt);
1766 		}
1767 	} while (object != old_tail);
1768 
1769 	if (*head == *tail)
1770 		*tail = NULL;
1771 
1772 	return *head != NULL;
1773 }
1774 
1775 static void *setup_object(struct kmem_cache *s, struct slab *slab,
1776 				void *object)
1777 {
1778 	setup_object_debug(s, slab, object);
1779 	object = kasan_init_slab_obj(s, object);
1780 	if (unlikely(s->ctor)) {
1781 		kasan_unpoison_object_data(s, object);
1782 		s->ctor(object);
1783 		kasan_poison_object_data(s, object);
1784 	}
1785 	return object;
1786 }
1787 
1788 /*
1789  * Slab allocation and freeing
1790  */
1791 static inline struct slab *alloc_slab_page(gfp_t flags, int node,
1792 		struct kmem_cache_order_objects oo)
1793 {
1794 	struct folio *folio;
1795 	struct slab *slab;
1796 	unsigned int order = oo_order(oo);
1797 
1798 	if (node == NUMA_NO_NODE)
1799 		folio = (struct folio *)alloc_pages(flags, order);
1800 	else
1801 		folio = (struct folio *)__alloc_pages_node(node, flags, order);
1802 
1803 	if (!folio)
1804 		return NULL;
1805 
1806 	slab = folio_slab(folio);
1807 	__folio_set_slab(folio);
1808 	if (page_is_pfmemalloc(folio_page(folio, 0)))
1809 		slab_set_pfmemalloc(slab);
1810 
1811 	return slab;
1812 }
1813 
1814 #ifdef CONFIG_SLAB_FREELIST_RANDOM
1815 /* Pre-initialize the random sequence cache */
1816 static int init_cache_random_seq(struct kmem_cache *s)
1817 {
1818 	unsigned int count = oo_objects(s->oo);
1819 	int err;
1820 
1821 	/* Bailout if already initialised */
1822 	if (s->random_seq)
1823 		return 0;
1824 
1825 	err = cache_random_seq_create(s, count, GFP_KERNEL);
1826 	if (err) {
1827 		pr_err("SLUB: Unable to initialize free list for %s\n",
1828 			s->name);
1829 		return err;
1830 	}
1831 
1832 	/* Transform to an offset on the set of pages */
1833 	if (s->random_seq) {
1834 		unsigned int i;
1835 
1836 		for (i = 0; i < count; i++)
1837 			s->random_seq[i] *= s->size;
1838 	}
1839 	return 0;
1840 }
1841 
1842 /* Initialize each random sequence freelist per cache */
1843 static void __init init_freelist_randomization(void)
1844 {
1845 	struct kmem_cache *s;
1846 
1847 	mutex_lock(&slab_mutex);
1848 
1849 	list_for_each_entry(s, &slab_caches, list)
1850 		init_cache_random_seq(s);
1851 
1852 	mutex_unlock(&slab_mutex);
1853 }
1854 
1855 /* Get the next entry on the pre-computed freelist randomized */
1856 static void *next_freelist_entry(struct kmem_cache *s, struct slab *slab,
1857 				unsigned long *pos, void *start,
1858 				unsigned long page_limit,
1859 				unsigned long freelist_count)
1860 {
1861 	unsigned int idx;
1862 
1863 	/*
1864 	 * If the target page allocation failed, the number of objects on the
1865 	 * page might be smaller than the usual size defined by the cache.
1866 	 */
1867 	do {
1868 		idx = s->random_seq[*pos];
1869 		*pos += 1;
1870 		if (*pos >= freelist_count)
1871 			*pos = 0;
1872 	} while (unlikely(idx >= page_limit));
1873 
1874 	return (char *)start + idx;
1875 }
1876 
1877 /* Shuffle the single linked freelist based on a random pre-computed sequence */
1878 static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
1879 {
1880 	void *start;
1881 	void *cur;
1882 	void *next;
1883 	unsigned long idx, pos, page_limit, freelist_count;
1884 
1885 	if (slab->objects < 2 || !s->random_seq)
1886 		return false;
1887 
1888 	freelist_count = oo_objects(s->oo);
1889 	pos = get_random_int() % freelist_count;
1890 
1891 	page_limit = slab->objects * s->size;
1892 	start = fixup_red_left(s, slab_address(slab));
1893 
1894 	/* First entry is used as the base of the freelist */
1895 	cur = next_freelist_entry(s, slab, &pos, start, page_limit,
1896 				freelist_count);
1897 	cur = setup_object(s, slab, cur);
1898 	slab->freelist = cur;
1899 
1900 	for (idx = 1; idx < slab->objects; idx++) {
1901 		next = next_freelist_entry(s, slab, &pos, start, page_limit,
1902 			freelist_count);
1903 		next = setup_object(s, slab, next);
1904 		set_freepointer(s, cur, next);
1905 		cur = next;
1906 	}
1907 	set_freepointer(s, cur, NULL);
1908 
1909 	return true;
1910 }
1911 #else
1912 static inline int init_cache_random_seq(struct kmem_cache *s)
1913 {
1914 	return 0;
1915 }
1916 static inline void init_freelist_randomization(void) { }
1917 static inline bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
1918 {
1919 	return false;
1920 }
1921 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
1922 
1923 static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
1924 {
1925 	struct slab *slab;
1926 	struct kmem_cache_order_objects oo = s->oo;
1927 	gfp_t alloc_gfp;
1928 	void *start, *p, *next;
1929 	int idx;
1930 	bool shuffle;
1931 
1932 	flags &= gfp_allowed_mask;
1933 
1934 	flags |= s->allocflags;
1935 
1936 	/*
1937 	 * Let the initial higher-order allocation fail under memory pressure
1938 	 * so we fall-back to the minimum order allocation.
1939 	 */
1940 	alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
1941 	if ((alloc_gfp & __GFP_DIRECT_RECLAIM) && oo_order(oo) > oo_order(s->min))
1942 		alloc_gfp = (alloc_gfp | __GFP_NOMEMALLOC) & ~(__GFP_RECLAIM|__GFP_NOFAIL);
1943 
1944 	slab = alloc_slab_page(alloc_gfp, node, oo);
1945 	if (unlikely(!slab)) {
1946 		oo = s->min;
1947 		alloc_gfp = flags;
1948 		/*
1949 		 * Allocation may have failed due to fragmentation.
1950 		 * Try a lower order alloc if possible
1951 		 */
1952 		slab = alloc_slab_page(alloc_gfp, node, oo);
1953 		if (unlikely(!slab))
1954 			goto out;
1955 		stat(s, ORDER_FALLBACK);
1956 	}
1957 
1958 	slab->objects = oo_objects(oo);
1959 
1960 	account_slab(slab, oo_order(oo), s, flags);
1961 
1962 	slab->slab_cache = s;
1963 
1964 	kasan_poison_slab(slab);
1965 
1966 	start = slab_address(slab);
1967 
1968 	setup_slab_debug(s, slab, start);
1969 
1970 	shuffle = shuffle_freelist(s, slab);
1971 
1972 	if (!shuffle) {
1973 		start = fixup_red_left(s, start);
1974 		start = setup_object(s, slab, start);
1975 		slab->freelist = start;
1976 		for (idx = 0, p = start; idx < slab->objects - 1; idx++) {
1977 			next = p + s->size;
1978 			next = setup_object(s, slab, next);
1979 			set_freepointer(s, p, next);
1980 			p = next;
1981 		}
1982 		set_freepointer(s, p, NULL);
1983 	}
1984 
1985 	slab->inuse = slab->objects;
1986 	slab->frozen = 1;
1987 
1988 out:
1989 	if (!slab)
1990 		return NULL;
1991 
1992 	inc_slabs_node(s, slab_nid(slab), slab->objects);
1993 
1994 	return slab;
1995 }
1996 
1997 static struct slab *new_slab(struct kmem_cache *s, gfp_t flags, int node)
1998 {
1999 	if (unlikely(flags & GFP_SLAB_BUG_MASK))
2000 		flags = kmalloc_fix_flags(flags);
2001 
2002 	WARN_ON_ONCE(s->ctor && (flags & __GFP_ZERO));
2003 
2004 	return allocate_slab(s,
2005 		flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
2006 }
2007 
2008 static void __free_slab(struct kmem_cache *s, struct slab *slab)
2009 {
2010 	struct folio *folio = slab_folio(slab);
2011 	int order = folio_order(folio);
2012 	int pages = 1 << order;
2013 
2014 	if (kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) {
2015 		void *p;
2016 
2017 		slab_pad_check(s, slab);
2018 		for_each_object(p, s, slab_address(slab), slab->objects)
2019 			check_object(s, slab, p, SLUB_RED_INACTIVE);
2020 	}
2021 
2022 	__slab_clear_pfmemalloc(slab);
2023 	__folio_clear_slab(folio);
2024 	folio->mapping = NULL;
2025 	if (current->reclaim_state)
2026 		current->reclaim_state->reclaimed_slab += pages;
2027 	unaccount_slab(slab, order, s);
2028 	__free_pages(folio_page(folio, 0), order);
2029 }
2030 
2031 static void rcu_free_slab(struct rcu_head *h)
2032 {
2033 	struct slab *slab = container_of(h, struct slab, rcu_head);
2034 
2035 	__free_slab(slab->slab_cache, slab);
2036 }
2037 
2038 static void free_slab(struct kmem_cache *s, struct slab *slab)
2039 {
2040 	if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU)) {
2041 		call_rcu(&slab->rcu_head, rcu_free_slab);
2042 	} else
2043 		__free_slab(s, slab);
2044 }
2045 
2046 static void discard_slab(struct kmem_cache *s, struct slab *slab)
2047 {
2048 	dec_slabs_node(s, slab_nid(slab), slab->objects);
2049 	free_slab(s, slab);
2050 }
2051 
2052 /*
2053  * Management of partially allocated slabs.
2054  */
2055 static inline void
2056 __add_partial(struct kmem_cache_node *n, struct slab *slab, int tail)
2057 {
2058 	n->nr_partial++;
2059 	if (tail == DEACTIVATE_TO_TAIL)
2060 		list_add_tail(&slab->slab_list, &n->partial);
2061 	else
2062 		list_add(&slab->slab_list, &n->partial);
2063 }
2064 
2065 static inline void add_partial(struct kmem_cache_node *n,
2066 				struct slab *slab, int tail)
2067 {
2068 	lockdep_assert_held(&n->list_lock);
2069 	__add_partial(n, slab, tail);
2070 }
2071 
2072 static inline void remove_partial(struct kmem_cache_node *n,
2073 					struct slab *slab)
2074 {
2075 	lockdep_assert_held(&n->list_lock);
2076 	list_del(&slab->slab_list);
2077 	n->nr_partial--;
2078 }
2079 
2080 /*
2081  * Remove slab from the partial list, freeze it and
2082  * return the pointer to the freelist.
2083  *
2084  * Returns a list of objects or NULL if it fails.
2085  */
2086 static inline void *acquire_slab(struct kmem_cache *s,
2087 		struct kmem_cache_node *n, struct slab *slab,
2088 		int mode)
2089 {
2090 	void *freelist;
2091 	unsigned long counters;
2092 	struct slab new;
2093 
2094 	lockdep_assert_held(&n->list_lock);
2095 
2096 	/*
2097 	 * Zap the freelist and set the frozen bit.
2098 	 * The old freelist is the list of objects for the
2099 	 * per cpu allocation list.
2100 	 */
2101 	freelist = slab->freelist;
2102 	counters = slab->counters;
2103 	new.counters = counters;
2104 	if (mode) {
2105 		new.inuse = slab->objects;
2106 		new.freelist = NULL;
2107 	} else {
2108 		new.freelist = freelist;
2109 	}
2110 
2111 	VM_BUG_ON(new.frozen);
2112 	new.frozen = 1;
2113 
2114 	if (!__cmpxchg_double_slab(s, slab,
2115 			freelist, counters,
2116 			new.freelist, new.counters,
2117 			"acquire_slab"))
2118 		return NULL;
2119 
2120 	remove_partial(n, slab);
2121 	WARN_ON(!freelist);
2122 	return freelist;
2123 }
2124 
2125 #ifdef CONFIG_SLUB_CPU_PARTIAL
2126 static void put_cpu_partial(struct kmem_cache *s, struct slab *slab, int drain);
2127 #else
2128 static inline void put_cpu_partial(struct kmem_cache *s, struct slab *slab,
2129 				   int drain) { }
2130 #endif
2131 static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags);
2132 
2133 /*
2134  * Try to allocate a partial slab from a specific node.
2135  */
2136 static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n,
2137 			      struct slab **ret_slab, gfp_t gfpflags)
2138 {
2139 	struct slab *slab, *slab2;
2140 	void *object = NULL;
2141 	unsigned long flags;
2142 	unsigned int partial_slabs = 0;
2143 
2144 	/*
2145 	 * Racy check. If we mistakenly see no partial slabs then we
2146 	 * just allocate an empty slab. If we mistakenly try to get a
2147 	 * partial slab and there is none available then get_partial()
2148 	 * will return NULL.
2149 	 */
2150 	if (!n || !n->nr_partial)
2151 		return NULL;
2152 
2153 	spin_lock_irqsave(&n->list_lock, flags);
2154 	list_for_each_entry_safe(slab, slab2, &n->partial, slab_list) {
2155 		void *t;
2156 
2157 		if (!pfmemalloc_match(slab, gfpflags))
2158 			continue;
2159 
2160 		t = acquire_slab(s, n, slab, object == NULL);
2161 		if (!t)
2162 			break;
2163 
2164 		if (!object) {
2165 			*ret_slab = slab;
2166 			stat(s, ALLOC_FROM_PARTIAL);
2167 			object = t;
2168 		} else {
2169 			put_cpu_partial(s, slab, 0);
2170 			stat(s, CPU_PARTIAL_NODE);
2171 			partial_slabs++;
2172 		}
2173 #ifdef CONFIG_SLUB_CPU_PARTIAL
2174 		if (!kmem_cache_has_cpu_partial(s)
2175 			|| partial_slabs > s->cpu_partial_slabs / 2)
2176 			break;
2177 #else
2178 		break;
2179 #endif
2180 
2181 	}
2182 	spin_unlock_irqrestore(&n->list_lock, flags);
2183 	return object;
2184 }
2185 
2186 /*
2187  * Get a slab from somewhere. Search in increasing NUMA distances.
2188  */
2189 static void *get_any_partial(struct kmem_cache *s, gfp_t flags,
2190 			     struct slab **ret_slab)
2191 {
2192 #ifdef CONFIG_NUMA
2193 	struct zonelist *zonelist;
2194 	struct zoneref *z;
2195 	struct zone *zone;
2196 	enum zone_type highest_zoneidx = gfp_zone(flags);
2197 	void *object;
2198 	unsigned int cpuset_mems_cookie;
2199 
2200 	/*
2201 	 * The defrag ratio allows a configuration of the tradeoffs between
2202 	 * inter node defragmentation and node local allocations. A lower
2203 	 * defrag_ratio increases the tendency to do local allocations
2204 	 * instead of attempting to obtain partial slabs from other nodes.
2205 	 *
2206 	 * If the defrag_ratio is set to 0 then kmalloc() always
2207 	 * returns node local objects. If the ratio is higher then kmalloc()
2208 	 * may return off node objects because partial slabs are obtained
2209 	 * from other nodes and filled up.
2210 	 *
2211 	 * If /sys/kernel/slab/xx/remote_node_defrag_ratio is set to 100
2212 	 * (which makes defrag_ratio = 1000) then every (well almost)
2213 	 * allocation will first attempt to defrag slab caches on other nodes.
2214 	 * This means scanning over all nodes to look for partial slabs which
2215 	 * may be expensive if we do it every time we are trying to find a slab
2216 	 * with available objects.
2217 	 */
2218 	if (!s->remote_node_defrag_ratio ||
2219 			get_cycles() % 1024 > s->remote_node_defrag_ratio)
2220 		return NULL;
2221 
2222 	do {
2223 		cpuset_mems_cookie = read_mems_allowed_begin();
2224 		zonelist = node_zonelist(mempolicy_slab_node(), flags);
2225 		for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
2226 			struct kmem_cache_node *n;
2227 
2228 			n = get_node(s, zone_to_nid(zone));
2229 
2230 			if (n && cpuset_zone_allowed(zone, flags) &&
2231 					n->nr_partial > s->min_partial) {
2232 				object = get_partial_node(s, n, ret_slab, flags);
2233 				if (object) {
2234 					/*
2235 					 * Don't check read_mems_allowed_retry()
2236 					 * here - if mems_allowed was updated in
2237 					 * parallel, that was a harmless race
2238 					 * between allocation and the cpuset
2239 					 * update
2240 					 */
2241 					return object;
2242 				}
2243 			}
2244 		}
2245 	} while (read_mems_allowed_retry(cpuset_mems_cookie));
2246 #endif	/* CONFIG_NUMA */
2247 	return NULL;
2248 }
2249 
2250 /*
2251  * Get a partial slab, lock it and return it.
2252  */
2253 static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
2254 			 struct slab **ret_slab)
2255 {
2256 	void *object;
2257 	int searchnode = node;
2258 
2259 	if (node == NUMA_NO_NODE)
2260 		searchnode = numa_mem_id();
2261 
2262 	object = get_partial_node(s, get_node(s, searchnode), ret_slab, flags);
2263 	if (object || node != NUMA_NO_NODE)
2264 		return object;
2265 
2266 	return get_any_partial(s, flags, ret_slab);
2267 }
2268 
2269 #ifdef CONFIG_PREEMPTION
2270 /*
2271  * Calculate the next globally unique transaction for disambiguation
2272  * during cmpxchg. The transactions start with the cpu number and are then
2273  * incremented by CONFIG_NR_CPUS.
2274  */
2275 #define TID_STEP  roundup_pow_of_two(CONFIG_NR_CPUS)
2276 #else
2277 /*
2278  * No preemption supported therefore also no need to check for
2279  * different cpus.
2280  */
2281 #define TID_STEP 1
2282 #endif
2283 
2284 static inline unsigned long next_tid(unsigned long tid)
2285 {
2286 	return tid + TID_STEP;
2287 }
2288 
2289 #ifdef SLUB_DEBUG_CMPXCHG
2290 static inline unsigned int tid_to_cpu(unsigned long tid)
2291 {
2292 	return tid % TID_STEP;
2293 }
2294 
2295 static inline unsigned long tid_to_event(unsigned long tid)
2296 {
2297 	return tid / TID_STEP;
2298 }
2299 #endif
2300 
2301 static inline unsigned int init_tid(int cpu)
2302 {
2303 	return cpu;
2304 }
2305 
2306 static inline void note_cmpxchg_failure(const char *n,
2307 		const struct kmem_cache *s, unsigned long tid)
2308 {
2309 #ifdef SLUB_DEBUG_CMPXCHG
2310 	unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
2311 
2312 	pr_info("%s %s: cmpxchg redo ", n, s->name);
2313 
2314 #ifdef CONFIG_PREEMPTION
2315 	if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
2316 		pr_warn("due to cpu change %d -> %d\n",
2317 			tid_to_cpu(tid), tid_to_cpu(actual_tid));
2318 	else
2319 #endif
2320 	if (tid_to_event(tid) != tid_to_event(actual_tid))
2321 		pr_warn("due to cpu running other code. Event %ld->%ld\n",
2322 			tid_to_event(tid), tid_to_event(actual_tid));
2323 	else
2324 		pr_warn("for unknown reason: actual=%lx was=%lx target=%lx\n",
2325 			actual_tid, tid, next_tid(tid));
2326 #endif
2327 	stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
2328 }
2329 
2330 static void init_kmem_cache_cpus(struct kmem_cache *s)
2331 {
2332 	int cpu;
2333 	struct kmem_cache_cpu *c;
2334 
2335 	for_each_possible_cpu(cpu) {
2336 		c = per_cpu_ptr(s->cpu_slab, cpu);
2337 		local_lock_init(&c->lock);
2338 		c->tid = init_tid(cpu);
2339 	}
2340 }
2341 
2342 /*
2343  * Finishes removing the cpu slab. Merges cpu's freelist with slab's freelist,
2344  * unfreezes the slabs and puts it on the proper list.
2345  * Assumes the slab has been already safely taken away from kmem_cache_cpu
2346  * by the caller.
2347  */
2348 static void deactivate_slab(struct kmem_cache *s, struct slab *slab,
2349 			    void *freelist)
2350 {
2351 	enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE, M_FULL_NOLIST };
2352 	struct kmem_cache_node *n = get_node(s, slab_nid(slab));
2353 	int free_delta = 0;
2354 	enum slab_modes mode = M_NONE;
2355 	void *nextfree, *freelist_iter, *freelist_tail;
2356 	int tail = DEACTIVATE_TO_HEAD;
2357 	unsigned long flags = 0;
2358 	struct slab new;
2359 	struct slab old;
2360 
2361 	if (slab->freelist) {
2362 		stat(s, DEACTIVATE_REMOTE_FREES);
2363 		tail = DEACTIVATE_TO_TAIL;
2364 	}
2365 
2366 	/*
2367 	 * Stage one: Count the objects on cpu's freelist as free_delta and
2368 	 * remember the last object in freelist_tail for later splicing.
2369 	 */
2370 	freelist_tail = NULL;
2371 	freelist_iter = freelist;
2372 	while (freelist_iter) {
2373 		nextfree = get_freepointer(s, freelist_iter);
2374 
2375 		/*
2376 		 * If 'nextfree' is invalid, it is possible that the object at
2377 		 * 'freelist_iter' is already corrupted.  So isolate all objects
2378 		 * starting at 'freelist_iter' by skipping them.
2379 		 */
2380 		if (freelist_corrupted(s, slab, &freelist_iter, nextfree))
2381 			break;
2382 
2383 		freelist_tail = freelist_iter;
2384 		free_delta++;
2385 
2386 		freelist_iter = nextfree;
2387 	}
2388 
2389 	/*
2390 	 * Stage two: Unfreeze the slab while splicing the per-cpu
2391 	 * freelist to the head of slab's freelist.
2392 	 *
2393 	 * Ensure that the slab is unfrozen while the list presence
2394 	 * reflects the actual number of objects during unfreeze.
2395 	 *
2396 	 * We first perform cmpxchg holding lock and insert to list
2397 	 * when it succeed. If there is mismatch then the slab is not
2398 	 * unfrozen and number of objects in the slab may have changed.
2399 	 * Then release lock and retry cmpxchg again.
2400 	 */
2401 redo:
2402 
2403 	old.freelist = READ_ONCE(slab->freelist);
2404 	old.counters = READ_ONCE(slab->counters);
2405 	VM_BUG_ON(!old.frozen);
2406 
2407 	/* Determine target state of the slab */
2408 	new.counters = old.counters;
2409 	if (freelist_tail) {
2410 		new.inuse -= free_delta;
2411 		set_freepointer(s, freelist_tail, old.freelist);
2412 		new.freelist = freelist;
2413 	} else
2414 		new.freelist = old.freelist;
2415 
2416 	new.frozen = 0;
2417 
2418 	if (!new.inuse && n->nr_partial >= s->min_partial) {
2419 		mode = M_FREE;
2420 	} else if (new.freelist) {
2421 		mode = M_PARTIAL;
2422 		/*
2423 		 * Taking the spinlock removes the possibility that
2424 		 * acquire_slab() will see a slab that is frozen
2425 		 */
2426 		spin_lock_irqsave(&n->list_lock, flags);
2427 	} else if (kmem_cache_debug_flags(s, SLAB_STORE_USER)) {
2428 		mode = M_FULL;
2429 		/*
2430 		 * This also ensures that the scanning of full
2431 		 * slabs from diagnostic functions will not see
2432 		 * any frozen slabs.
2433 		 */
2434 		spin_lock_irqsave(&n->list_lock, flags);
2435 	} else {
2436 		mode = M_FULL_NOLIST;
2437 	}
2438 
2439 
2440 	if (!cmpxchg_double_slab(s, slab,
2441 				old.freelist, old.counters,
2442 				new.freelist, new.counters,
2443 				"unfreezing slab")) {
2444 		if (mode == M_PARTIAL || mode == M_FULL)
2445 			spin_unlock_irqrestore(&n->list_lock, flags);
2446 		goto redo;
2447 	}
2448 
2449 
2450 	if (mode == M_PARTIAL) {
2451 		add_partial(n, slab, tail);
2452 		spin_unlock_irqrestore(&n->list_lock, flags);
2453 		stat(s, tail);
2454 	} else if (mode == M_FREE) {
2455 		stat(s, DEACTIVATE_EMPTY);
2456 		discard_slab(s, slab);
2457 		stat(s, FREE_SLAB);
2458 	} else if (mode == M_FULL) {
2459 		add_full(s, n, slab);
2460 		spin_unlock_irqrestore(&n->list_lock, flags);
2461 		stat(s, DEACTIVATE_FULL);
2462 	} else if (mode == M_FULL_NOLIST) {
2463 		stat(s, DEACTIVATE_FULL);
2464 	}
2465 }
2466 
2467 #ifdef CONFIG_SLUB_CPU_PARTIAL
2468 static void __unfreeze_partials(struct kmem_cache *s, struct slab *partial_slab)
2469 {
2470 	struct kmem_cache_node *n = NULL, *n2 = NULL;
2471 	struct slab *slab, *slab_to_discard = NULL;
2472 	unsigned long flags = 0;
2473 
2474 	while (partial_slab) {
2475 		struct slab new;
2476 		struct slab old;
2477 
2478 		slab = partial_slab;
2479 		partial_slab = slab->next;
2480 
2481 		n2 = get_node(s, slab_nid(slab));
2482 		if (n != n2) {
2483 			if (n)
2484 				spin_unlock_irqrestore(&n->list_lock, flags);
2485 
2486 			n = n2;
2487 			spin_lock_irqsave(&n->list_lock, flags);
2488 		}
2489 
2490 		do {
2491 
2492 			old.freelist = slab->freelist;
2493 			old.counters = slab->counters;
2494 			VM_BUG_ON(!old.frozen);
2495 
2496 			new.counters = old.counters;
2497 			new.freelist = old.freelist;
2498 
2499 			new.frozen = 0;
2500 
2501 		} while (!__cmpxchg_double_slab(s, slab,
2502 				old.freelist, old.counters,
2503 				new.freelist, new.counters,
2504 				"unfreezing slab"));
2505 
2506 		if (unlikely(!new.inuse && n->nr_partial >= s->min_partial)) {
2507 			slab->next = slab_to_discard;
2508 			slab_to_discard = slab;
2509 		} else {
2510 			add_partial(n, slab, DEACTIVATE_TO_TAIL);
2511 			stat(s, FREE_ADD_PARTIAL);
2512 		}
2513 	}
2514 
2515 	if (n)
2516 		spin_unlock_irqrestore(&n->list_lock, flags);
2517 
2518 	while (slab_to_discard) {
2519 		slab = slab_to_discard;
2520 		slab_to_discard = slab_to_discard->next;
2521 
2522 		stat(s, DEACTIVATE_EMPTY);
2523 		discard_slab(s, slab);
2524 		stat(s, FREE_SLAB);
2525 	}
2526 }
2527 
2528 /*
2529  * Unfreeze all the cpu partial slabs.
2530  */
2531 static void unfreeze_partials(struct kmem_cache *s)
2532 {
2533 	struct slab *partial_slab;
2534 	unsigned long flags;
2535 
2536 	local_lock_irqsave(&s->cpu_slab->lock, flags);
2537 	partial_slab = this_cpu_read(s->cpu_slab->partial);
2538 	this_cpu_write(s->cpu_slab->partial, NULL);
2539 	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2540 
2541 	if (partial_slab)
2542 		__unfreeze_partials(s, partial_slab);
2543 }
2544 
2545 static void unfreeze_partials_cpu(struct kmem_cache *s,
2546 				  struct kmem_cache_cpu *c)
2547 {
2548 	struct slab *partial_slab;
2549 
2550 	partial_slab = slub_percpu_partial(c);
2551 	c->partial = NULL;
2552 
2553 	if (partial_slab)
2554 		__unfreeze_partials(s, partial_slab);
2555 }
2556 
2557 /*
2558  * Put a slab that was just frozen (in __slab_free|get_partial_node) into a
2559  * partial slab slot if available.
2560  *
2561  * If we did not find a slot then simply move all the partials to the
2562  * per node partial list.
2563  */
2564 static void put_cpu_partial(struct kmem_cache *s, struct slab *slab, int drain)
2565 {
2566 	struct slab *oldslab;
2567 	struct slab *slab_to_unfreeze = NULL;
2568 	unsigned long flags;
2569 	int slabs = 0;
2570 
2571 	local_lock_irqsave(&s->cpu_slab->lock, flags);
2572 
2573 	oldslab = this_cpu_read(s->cpu_slab->partial);
2574 
2575 	if (oldslab) {
2576 		if (drain && oldslab->slabs >= s->cpu_partial_slabs) {
2577 			/*
2578 			 * Partial array is full. Move the existing set to the
2579 			 * per node partial list. Postpone the actual unfreezing
2580 			 * outside of the critical section.
2581 			 */
2582 			slab_to_unfreeze = oldslab;
2583 			oldslab = NULL;
2584 		} else {
2585 			slabs = oldslab->slabs;
2586 		}
2587 	}
2588 
2589 	slabs++;
2590 
2591 	slab->slabs = slabs;
2592 	slab->next = oldslab;
2593 
2594 	this_cpu_write(s->cpu_slab->partial, slab);
2595 
2596 	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2597 
2598 	if (slab_to_unfreeze) {
2599 		__unfreeze_partials(s, slab_to_unfreeze);
2600 		stat(s, CPU_PARTIAL_DRAIN);
2601 	}
2602 }
2603 
2604 #else	/* CONFIG_SLUB_CPU_PARTIAL */
2605 
2606 static inline void unfreeze_partials(struct kmem_cache *s) { }
2607 static inline void unfreeze_partials_cpu(struct kmem_cache *s,
2608 				  struct kmem_cache_cpu *c) { }
2609 
2610 #endif	/* CONFIG_SLUB_CPU_PARTIAL */
2611 
2612 static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
2613 {
2614 	unsigned long flags;
2615 	struct slab *slab;
2616 	void *freelist;
2617 
2618 	local_lock_irqsave(&s->cpu_slab->lock, flags);
2619 
2620 	slab = c->slab;
2621 	freelist = c->freelist;
2622 
2623 	c->slab = NULL;
2624 	c->freelist = NULL;
2625 	c->tid = next_tid(c->tid);
2626 
2627 	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2628 
2629 	if (slab) {
2630 		deactivate_slab(s, slab, freelist);
2631 		stat(s, CPUSLAB_FLUSH);
2632 	}
2633 }
2634 
2635 static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
2636 {
2637 	struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
2638 	void *freelist = c->freelist;
2639 	struct slab *slab = c->slab;
2640 
2641 	c->slab = NULL;
2642 	c->freelist = NULL;
2643 	c->tid = next_tid(c->tid);
2644 
2645 	if (slab) {
2646 		deactivate_slab(s, slab, freelist);
2647 		stat(s, CPUSLAB_FLUSH);
2648 	}
2649 
2650 	unfreeze_partials_cpu(s, c);
2651 }
2652 
2653 struct slub_flush_work {
2654 	struct work_struct work;
2655 	struct kmem_cache *s;
2656 	bool skip;
2657 };
2658 
2659 /*
2660  * Flush cpu slab.
2661  *
2662  * Called from CPU work handler with migration disabled.
2663  */
2664 static void flush_cpu_slab(struct work_struct *w)
2665 {
2666 	struct kmem_cache *s;
2667 	struct kmem_cache_cpu *c;
2668 	struct slub_flush_work *sfw;
2669 
2670 	sfw = container_of(w, struct slub_flush_work, work);
2671 
2672 	s = sfw->s;
2673 	c = this_cpu_ptr(s->cpu_slab);
2674 
2675 	if (c->slab)
2676 		flush_slab(s, c);
2677 
2678 	unfreeze_partials(s);
2679 }
2680 
2681 static bool has_cpu_slab(int cpu, struct kmem_cache *s)
2682 {
2683 	struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
2684 
2685 	return c->slab || slub_percpu_partial(c);
2686 }
2687 
2688 static DEFINE_MUTEX(flush_lock);
2689 static DEFINE_PER_CPU(struct slub_flush_work, slub_flush);
2690 
2691 static void flush_all_cpus_locked(struct kmem_cache *s)
2692 {
2693 	struct slub_flush_work *sfw;
2694 	unsigned int cpu;
2695 
2696 	lockdep_assert_cpus_held();
2697 	mutex_lock(&flush_lock);
2698 
2699 	for_each_online_cpu(cpu) {
2700 		sfw = &per_cpu(slub_flush, cpu);
2701 		if (!has_cpu_slab(cpu, s)) {
2702 			sfw->skip = true;
2703 			continue;
2704 		}
2705 		INIT_WORK(&sfw->work, flush_cpu_slab);
2706 		sfw->skip = false;
2707 		sfw->s = s;
2708 		schedule_work_on(cpu, &sfw->work);
2709 	}
2710 
2711 	for_each_online_cpu(cpu) {
2712 		sfw = &per_cpu(slub_flush, cpu);
2713 		if (sfw->skip)
2714 			continue;
2715 		flush_work(&sfw->work);
2716 	}
2717 
2718 	mutex_unlock(&flush_lock);
2719 }
2720 
2721 static void flush_all(struct kmem_cache *s)
2722 {
2723 	cpus_read_lock();
2724 	flush_all_cpus_locked(s);
2725 	cpus_read_unlock();
2726 }
2727 
2728 /*
2729  * Use the cpu notifier to insure that the cpu slabs are flushed when
2730  * necessary.
2731  */
2732 static int slub_cpu_dead(unsigned int cpu)
2733 {
2734 	struct kmem_cache *s;
2735 
2736 	mutex_lock(&slab_mutex);
2737 	list_for_each_entry(s, &slab_caches, list)
2738 		__flush_cpu_slab(s, cpu);
2739 	mutex_unlock(&slab_mutex);
2740 	return 0;
2741 }
2742 
2743 /*
2744  * Check if the objects in a per cpu structure fit numa
2745  * locality expectations.
2746  */
2747 static inline int node_match(struct slab *slab, int node)
2748 {
2749 #ifdef CONFIG_NUMA
2750 	if (node != NUMA_NO_NODE && slab_nid(slab) != node)
2751 		return 0;
2752 #endif
2753 	return 1;
2754 }
2755 
2756 #ifdef CONFIG_SLUB_DEBUG
2757 static int count_free(struct slab *slab)
2758 {
2759 	return slab->objects - slab->inuse;
2760 }
2761 
2762 static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
2763 {
2764 	return atomic_long_read(&n->total_objects);
2765 }
2766 #endif /* CONFIG_SLUB_DEBUG */
2767 
2768 #if defined(CONFIG_SLUB_DEBUG) || defined(CONFIG_SYSFS)
2769 static unsigned long count_partial(struct kmem_cache_node *n,
2770 					int (*get_count)(struct slab *))
2771 {
2772 	unsigned long flags;
2773 	unsigned long x = 0;
2774 	struct slab *slab;
2775 
2776 	spin_lock_irqsave(&n->list_lock, flags);
2777 	list_for_each_entry(slab, &n->partial, slab_list)
2778 		x += get_count(slab);
2779 	spin_unlock_irqrestore(&n->list_lock, flags);
2780 	return x;
2781 }
2782 #endif /* CONFIG_SLUB_DEBUG || CONFIG_SYSFS */
2783 
2784 static noinline void
2785 slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
2786 {
2787 #ifdef CONFIG_SLUB_DEBUG
2788 	static DEFINE_RATELIMIT_STATE(slub_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
2789 				      DEFAULT_RATELIMIT_BURST);
2790 	int node;
2791 	struct kmem_cache_node *n;
2792 
2793 	if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slub_oom_rs))
2794 		return;
2795 
2796 	pr_warn("SLUB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n",
2797 		nid, gfpflags, &gfpflags);
2798 	pr_warn("  cache: %s, object size: %u, buffer size: %u, default order: %u, min order: %u\n",
2799 		s->name, s->object_size, s->size, oo_order(s->oo),
2800 		oo_order(s->min));
2801 
2802 	if (oo_order(s->min) > get_order(s->object_size))
2803 		pr_warn("  %s debugging increased min order, use slub_debug=O to disable.\n",
2804 			s->name);
2805 
2806 	for_each_kmem_cache_node(s, node, n) {
2807 		unsigned long nr_slabs;
2808 		unsigned long nr_objs;
2809 		unsigned long nr_free;
2810 
2811 		nr_free  = count_partial(n, count_free);
2812 		nr_slabs = node_nr_slabs(n);
2813 		nr_objs  = node_nr_objs(n);
2814 
2815 		pr_warn("  node %d: slabs: %ld, objs: %ld, free: %ld\n",
2816 			node, nr_slabs, nr_objs, nr_free);
2817 	}
2818 #endif
2819 }
2820 
2821 static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags)
2822 {
2823 	if (unlikely(slab_test_pfmemalloc(slab)))
2824 		return gfp_pfmemalloc_allowed(gfpflags);
2825 
2826 	return true;
2827 }
2828 
2829 /*
2830  * Check the slab->freelist and either transfer the freelist to the
2831  * per cpu freelist or deactivate the slab.
2832  *
2833  * The slab is still frozen if the return value is not NULL.
2834  *
2835  * If this function returns NULL then the slab has been unfrozen.
2836  */
2837 static inline void *get_freelist(struct kmem_cache *s, struct slab *slab)
2838 {
2839 	struct slab new;
2840 	unsigned long counters;
2841 	void *freelist;
2842 
2843 	lockdep_assert_held(this_cpu_ptr(&s->cpu_slab->lock));
2844 
2845 	do {
2846 		freelist = slab->freelist;
2847 		counters = slab->counters;
2848 
2849 		new.counters = counters;
2850 		VM_BUG_ON(!new.frozen);
2851 
2852 		new.inuse = slab->objects;
2853 		new.frozen = freelist != NULL;
2854 
2855 	} while (!__cmpxchg_double_slab(s, slab,
2856 		freelist, counters,
2857 		NULL, new.counters,
2858 		"get_freelist"));
2859 
2860 	return freelist;
2861 }
2862 
2863 /*
2864  * Slow path. The lockless freelist is empty or we need to perform
2865  * debugging duties.
2866  *
2867  * Processing is still very fast if new objects have been freed to the
2868  * regular freelist. In that case we simply take over the regular freelist
2869  * as the lockless freelist and zap the regular freelist.
2870  *
2871  * If that is not working then we fall back to the partial lists. We take the
2872  * first element of the freelist as the object to allocate now and move the
2873  * rest of the freelist to the lockless freelist.
2874  *
2875  * And if we were unable to get a new slab from the partial slab lists then
2876  * we need to allocate a new slab. This is the slowest path since it involves
2877  * a call to the page allocator and the setup of a new slab.
2878  *
2879  * Version of __slab_alloc to use when we know that preemption is
2880  * already disabled (which is the case for bulk allocation).
2881  */
2882 static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
2883 			  unsigned long addr, struct kmem_cache_cpu *c)
2884 {
2885 	void *freelist;
2886 	struct slab *slab;
2887 	unsigned long flags;
2888 
2889 	stat(s, ALLOC_SLOWPATH);
2890 
2891 reread_slab:
2892 
2893 	slab = READ_ONCE(c->slab);
2894 	if (!slab) {
2895 		/*
2896 		 * if the node is not online or has no normal memory, just
2897 		 * ignore the node constraint
2898 		 */
2899 		if (unlikely(node != NUMA_NO_NODE &&
2900 			     !node_isset(node, slab_nodes)))
2901 			node = NUMA_NO_NODE;
2902 		goto new_slab;
2903 	}
2904 redo:
2905 
2906 	if (unlikely(!node_match(slab, node))) {
2907 		/*
2908 		 * same as above but node_match() being false already
2909 		 * implies node != NUMA_NO_NODE
2910 		 */
2911 		if (!node_isset(node, slab_nodes)) {
2912 			node = NUMA_NO_NODE;
2913 			goto redo;
2914 		} else {
2915 			stat(s, ALLOC_NODE_MISMATCH);
2916 			goto deactivate_slab;
2917 		}
2918 	}
2919 
2920 	/*
2921 	 * By rights, we should be searching for a slab page that was
2922 	 * PFMEMALLOC but right now, we are losing the pfmemalloc
2923 	 * information when the page leaves the per-cpu allocator
2924 	 */
2925 	if (unlikely(!pfmemalloc_match(slab, gfpflags)))
2926 		goto deactivate_slab;
2927 
2928 	/* must check again c->slab in case we got preempted and it changed */
2929 	local_lock_irqsave(&s->cpu_slab->lock, flags);
2930 	if (unlikely(slab != c->slab)) {
2931 		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2932 		goto reread_slab;
2933 	}
2934 	freelist = c->freelist;
2935 	if (freelist)
2936 		goto load_freelist;
2937 
2938 	freelist = get_freelist(s, slab);
2939 
2940 	if (!freelist) {
2941 		c->slab = NULL;
2942 		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2943 		stat(s, DEACTIVATE_BYPASS);
2944 		goto new_slab;
2945 	}
2946 
2947 	stat(s, ALLOC_REFILL);
2948 
2949 load_freelist:
2950 
2951 	lockdep_assert_held(this_cpu_ptr(&s->cpu_slab->lock));
2952 
2953 	/*
2954 	 * freelist is pointing to the list of objects to be used.
2955 	 * slab is pointing to the slab from which the objects are obtained.
2956 	 * That slab must be frozen for per cpu allocations to work.
2957 	 */
2958 	VM_BUG_ON(!c->slab->frozen);
2959 	c->freelist = get_freepointer(s, freelist);
2960 	c->tid = next_tid(c->tid);
2961 	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2962 	return freelist;
2963 
2964 deactivate_slab:
2965 
2966 	local_lock_irqsave(&s->cpu_slab->lock, flags);
2967 	if (slab != c->slab) {
2968 		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2969 		goto reread_slab;
2970 	}
2971 	freelist = c->freelist;
2972 	c->slab = NULL;
2973 	c->freelist = NULL;
2974 	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2975 	deactivate_slab(s, slab, freelist);
2976 
2977 new_slab:
2978 
2979 	if (slub_percpu_partial(c)) {
2980 		local_lock_irqsave(&s->cpu_slab->lock, flags);
2981 		if (unlikely(c->slab)) {
2982 			local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2983 			goto reread_slab;
2984 		}
2985 		if (unlikely(!slub_percpu_partial(c))) {
2986 			local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2987 			/* we were preempted and partial list got empty */
2988 			goto new_objects;
2989 		}
2990 
2991 		slab = c->slab = slub_percpu_partial(c);
2992 		slub_set_percpu_partial(c, slab);
2993 		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
2994 		stat(s, CPU_PARTIAL_ALLOC);
2995 		goto redo;
2996 	}
2997 
2998 new_objects:
2999 
3000 	freelist = get_partial(s, gfpflags, node, &slab);
3001 	if (freelist)
3002 		goto check_new_slab;
3003 
3004 	slub_put_cpu_ptr(s->cpu_slab);
3005 	slab = new_slab(s, gfpflags, node);
3006 	c = slub_get_cpu_ptr(s->cpu_slab);
3007 
3008 	if (unlikely(!slab)) {
3009 		slab_out_of_memory(s, gfpflags, node);
3010 		return NULL;
3011 	}
3012 
3013 	/*
3014 	 * No other reference to the slab yet so we can
3015 	 * muck around with it freely without cmpxchg
3016 	 */
3017 	freelist = slab->freelist;
3018 	slab->freelist = NULL;
3019 
3020 	stat(s, ALLOC_SLAB);
3021 
3022 check_new_slab:
3023 
3024 	if (kmem_cache_debug(s)) {
3025 		if (!alloc_debug_processing(s, slab, freelist, addr)) {
3026 			/* Slab failed checks. Next slab needed */
3027 			goto new_slab;
3028 		} else {
3029 			/*
3030 			 * For debug case, we don't load freelist so that all
3031 			 * allocations go through alloc_debug_processing()
3032 			 */
3033 			goto return_single;
3034 		}
3035 	}
3036 
3037 	if (unlikely(!pfmemalloc_match(slab, gfpflags)))
3038 		/*
3039 		 * For !pfmemalloc_match() case we don't load freelist so that
3040 		 * we don't make further mismatched allocations easier.
3041 		 */
3042 		goto return_single;
3043 
3044 retry_load_slab:
3045 
3046 	local_lock_irqsave(&s->cpu_slab->lock, flags);
3047 	if (unlikely(c->slab)) {
3048 		void *flush_freelist = c->freelist;
3049 		struct slab *flush_slab = c->slab;
3050 
3051 		c->slab = NULL;
3052 		c->freelist = NULL;
3053 		c->tid = next_tid(c->tid);
3054 
3055 		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3056 
3057 		deactivate_slab(s, flush_slab, flush_freelist);
3058 
3059 		stat(s, CPUSLAB_FLUSH);
3060 
3061 		goto retry_load_slab;
3062 	}
3063 	c->slab = slab;
3064 
3065 	goto load_freelist;
3066 
3067 return_single:
3068 
3069 	deactivate_slab(s, slab, get_freepointer(s, freelist));
3070 	return freelist;
3071 }
3072 
3073 /*
3074  * A wrapper for ___slab_alloc() for contexts where preemption is not yet
3075  * disabled. Compensates for possible cpu changes by refetching the per cpu area
3076  * pointer.
3077  */
3078 static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
3079 			  unsigned long addr, struct kmem_cache_cpu *c)
3080 {
3081 	void *p;
3082 
3083 #ifdef CONFIG_PREEMPT_COUNT
3084 	/*
3085 	 * We may have been preempted and rescheduled on a different
3086 	 * cpu before disabling preemption. Need to reload cpu area
3087 	 * pointer.
3088 	 */
3089 	c = slub_get_cpu_ptr(s->cpu_slab);
3090 #endif
3091 
3092 	p = ___slab_alloc(s, gfpflags, node, addr, c);
3093 #ifdef CONFIG_PREEMPT_COUNT
3094 	slub_put_cpu_ptr(s->cpu_slab);
3095 #endif
3096 	return p;
3097 }
3098 
3099 /*
3100  * If the object has been wiped upon free, make sure it's fully initialized by
3101  * zeroing out freelist pointer.
3102  */
3103 static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
3104 						   void *obj)
3105 {
3106 	if (unlikely(slab_want_init_on_free(s)) && obj)
3107 		memset((void *)((char *)kasan_reset_tag(obj) + s->offset),
3108 			0, sizeof(void *));
3109 }
3110 
3111 /*
3112  * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
3113  * have the fastpath folded into their functions. So no function call
3114  * overhead for requests that can be satisfied on the fastpath.
3115  *
3116  * The fastpath works by first checking if the lockless freelist can be used.
3117  * If not then __slab_alloc is called for slow processing.
3118  *
3119  * Otherwise we can simply pick the next object from the lockless free list.
3120  */
3121 static __always_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru,
3122 		gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
3123 {
3124 	void *object;
3125 	struct kmem_cache_cpu *c;
3126 	struct slab *slab;
3127 	unsigned long tid;
3128 	struct obj_cgroup *objcg = NULL;
3129 	bool init = false;
3130 
3131 	s = slab_pre_alloc_hook(s, lru, &objcg, 1, gfpflags);
3132 	if (!s)
3133 		return NULL;
3134 
3135 	object = kfence_alloc(s, orig_size, gfpflags);
3136 	if (unlikely(object))
3137 		goto out;
3138 
3139 redo:
3140 	/*
3141 	 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
3142 	 * enabled. We may switch back and forth between cpus while
3143 	 * reading from one cpu area. That does not matter as long
3144 	 * as we end up on the original cpu again when doing the cmpxchg.
3145 	 *
3146 	 * We must guarantee that tid and kmem_cache_cpu are retrieved on the
3147 	 * same cpu. We read first the kmem_cache_cpu pointer and use it to read
3148 	 * the tid. If we are preempted and switched to another cpu between the
3149 	 * two reads, it's OK as the two are still associated with the same cpu
3150 	 * and cmpxchg later will validate the cpu.
3151 	 */
3152 	c = raw_cpu_ptr(s->cpu_slab);
3153 	tid = READ_ONCE(c->tid);
3154 
3155 	/*
3156 	 * Irqless object alloc/free algorithm used here depends on sequence
3157 	 * of fetching cpu_slab's data. tid should be fetched before anything
3158 	 * on c to guarantee that object and slab associated with previous tid
3159 	 * won't be used with current tid. If we fetch tid first, object and
3160 	 * slab could be one associated with next tid and our alloc/free
3161 	 * request will be failed. In this case, we will retry. So, no problem.
3162 	 */
3163 	barrier();
3164 
3165 	/*
3166 	 * The transaction ids are globally unique per cpu and per operation on
3167 	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
3168 	 * occurs on the right processor and that there was no operation on the
3169 	 * linked list in between.
3170 	 */
3171 
3172 	object = c->freelist;
3173 	slab = c->slab;
3174 	/*
3175 	 * We cannot use the lockless fastpath on PREEMPT_RT because if a
3176 	 * slowpath has taken the local_lock_irqsave(), it is not protected
3177 	 * against a fast path operation in an irq handler. So we need to take
3178 	 * the slow path which uses local_lock. It is still relatively fast if
3179 	 * there is a suitable cpu freelist.
3180 	 */
3181 	if (IS_ENABLED(CONFIG_PREEMPT_RT) ||
3182 	    unlikely(!object || !slab || !node_match(slab, node))) {
3183 		object = __slab_alloc(s, gfpflags, node, addr, c);
3184 	} else {
3185 		void *next_object = get_freepointer_safe(s, object);
3186 
3187 		/*
3188 		 * The cmpxchg will only match if there was no additional
3189 		 * operation and if we are on the right processor.
3190 		 *
3191 		 * The cmpxchg does the following atomically (without lock
3192 		 * semantics!)
3193 		 * 1. Relocate first pointer to the current per cpu area.
3194 		 * 2. Verify that tid and freelist have not been changed
3195 		 * 3. If they were not changed replace tid and freelist
3196 		 *
3197 		 * Since this is without lock semantics the protection is only
3198 		 * against code executing on this cpu *not* from access by
3199 		 * other cpus.
3200 		 */
3201 		if (unlikely(!this_cpu_cmpxchg_double(
3202 				s->cpu_slab->freelist, s->cpu_slab->tid,
3203 				object, tid,
3204 				next_object, next_tid(tid)))) {
3205 
3206 			note_cmpxchg_failure("slab_alloc", s, tid);
3207 			goto redo;
3208 		}
3209 		prefetch_freepointer(s, next_object);
3210 		stat(s, ALLOC_FASTPATH);
3211 	}
3212 
3213 	maybe_wipe_obj_freeptr(s, object);
3214 	init = slab_want_init_on_alloc(gfpflags, s);
3215 
3216 out:
3217 	slab_post_alloc_hook(s, objcg, gfpflags, 1, &object, init);
3218 
3219 	return object;
3220 }
3221 
3222 static __always_inline void *slab_alloc(struct kmem_cache *s, struct list_lru *lru,
3223 		gfp_t gfpflags, unsigned long addr, size_t orig_size)
3224 {
3225 	return slab_alloc_node(s, lru, gfpflags, NUMA_NO_NODE, addr, orig_size);
3226 }
3227 
3228 static __always_inline
3229 void *__kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
3230 			     gfp_t gfpflags)
3231 {
3232 	void *ret = slab_alloc(s, lru, gfpflags, _RET_IP_, s->object_size);
3233 
3234 	trace_kmem_cache_alloc(_RET_IP_, ret, s->object_size,
3235 				s->size, gfpflags);
3236 
3237 	return ret;
3238 }
3239 
3240 void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
3241 {
3242 	return __kmem_cache_alloc_lru(s, NULL, gfpflags);
3243 }
3244 EXPORT_SYMBOL(kmem_cache_alloc);
3245 
3246 void *kmem_cache_alloc_lru(struct kmem_cache *s, struct list_lru *lru,
3247 			   gfp_t gfpflags)
3248 {
3249 	return __kmem_cache_alloc_lru(s, lru, gfpflags);
3250 }
3251 EXPORT_SYMBOL(kmem_cache_alloc_lru);
3252 
3253 #ifdef CONFIG_TRACING
3254 void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
3255 {
3256 	void *ret = slab_alloc(s, NULL, gfpflags, _RET_IP_, size);
3257 	trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
3258 	ret = kasan_kmalloc(s, ret, size, gfpflags);
3259 	return ret;
3260 }
3261 EXPORT_SYMBOL(kmem_cache_alloc_trace);
3262 #endif
3263 
3264 #ifdef CONFIG_NUMA
3265 void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
3266 {
3267 	void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, s->object_size);
3268 
3269 	trace_kmem_cache_alloc_node(_RET_IP_, ret,
3270 				    s->object_size, s->size, gfpflags, node);
3271 
3272 	return ret;
3273 }
3274 EXPORT_SYMBOL(kmem_cache_alloc_node);
3275 
3276 #ifdef CONFIG_TRACING
3277 void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
3278 				    gfp_t gfpflags,
3279 				    int node, size_t size)
3280 {
3281 	void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, size);
3282 
3283 	trace_kmalloc_node(_RET_IP_, ret,
3284 			   size, s->size, gfpflags, node);
3285 
3286 	ret = kasan_kmalloc(s, ret, size, gfpflags);
3287 	return ret;
3288 }
3289 EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
3290 #endif
3291 #endif	/* CONFIG_NUMA */
3292 
3293 /*
3294  * Slow path handling. This may still be called frequently since objects
3295  * have a longer lifetime than the cpu slabs in most processing loads.
3296  *
3297  * So we still attempt to reduce cache line usage. Just take the slab
3298  * lock and free the item. If there is no additional partial slab
3299  * handling required then we can return immediately.
3300  */
3301 static void __slab_free(struct kmem_cache *s, struct slab *slab,
3302 			void *head, void *tail, int cnt,
3303 			unsigned long addr)
3304 
3305 {
3306 	void *prior;
3307 	int was_frozen;
3308 	struct slab new;
3309 	unsigned long counters;
3310 	struct kmem_cache_node *n = NULL;
3311 	unsigned long flags;
3312 
3313 	stat(s, FREE_SLOWPATH);
3314 
3315 	if (kfence_free(head))
3316 		return;
3317 
3318 	if (kmem_cache_debug(s) &&
3319 	    !free_debug_processing(s, slab, head, tail, cnt, addr))
3320 		return;
3321 
3322 	do {
3323 		if (unlikely(n)) {
3324 			spin_unlock_irqrestore(&n->list_lock, flags);
3325 			n = NULL;
3326 		}
3327 		prior = slab->freelist;
3328 		counters = slab->counters;
3329 		set_freepointer(s, tail, prior);
3330 		new.counters = counters;
3331 		was_frozen = new.frozen;
3332 		new.inuse -= cnt;
3333 		if ((!new.inuse || !prior) && !was_frozen) {
3334 
3335 			if (kmem_cache_has_cpu_partial(s) && !prior) {
3336 
3337 				/*
3338 				 * Slab was on no list before and will be
3339 				 * partially empty
3340 				 * We can defer the list move and instead
3341 				 * freeze it.
3342 				 */
3343 				new.frozen = 1;
3344 
3345 			} else { /* Needs to be taken off a list */
3346 
3347 				n = get_node(s, slab_nid(slab));
3348 				/*
3349 				 * Speculatively acquire the list_lock.
3350 				 * If the cmpxchg does not succeed then we may
3351 				 * drop the list_lock without any processing.
3352 				 *
3353 				 * Otherwise the list_lock will synchronize with
3354 				 * other processors updating the list of slabs.
3355 				 */
3356 				spin_lock_irqsave(&n->list_lock, flags);
3357 
3358 			}
3359 		}
3360 
3361 	} while (!cmpxchg_double_slab(s, slab,
3362 		prior, counters,
3363 		head, new.counters,
3364 		"__slab_free"));
3365 
3366 	if (likely(!n)) {
3367 
3368 		if (likely(was_frozen)) {
3369 			/*
3370 			 * The list lock was not taken therefore no list
3371 			 * activity can be necessary.
3372 			 */
3373 			stat(s, FREE_FROZEN);
3374 		} else if (new.frozen) {
3375 			/*
3376 			 * If we just froze the slab then put it onto the
3377 			 * per cpu partial list.
3378 			 */
3379 			put_cpu_partial(s, slab, 1);
3380 			stat(s, CPU_PARTIAL_FREE);
3381 		}
3382 
3383 		return;
3384 	}
3385 
3386 	if (unlikely(!new.inuse && n->nr_partial >= s->min_partial))
3387 		goto slab_empty;
3388 
3389 	/*
3390 	 * Objects left in the slab. If it was not on the partial list before
3391 	 * then add it.
3392 	 */
3393 	if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
3394 		remove_full(s, n, slab);
3395 		add_partial(n, slab, DEACTIVATE_TO_TAIL);
3396 		stat(s, FREE_ADD_PARTIAL);
3397 	}
3398 	spin_unlock_irqrestore(&n->list_lock, flags);
3399 	return;
3400 
3401 slab_empty:
3402 	if (prior) {
3403 		/*
3404 		 * Slab on the partial list.
3405 		 */
3406 		remove_partial(n, slab);
3407 		stat(s, FREE_REMOVE_PARTIAL);
3408 	} else {
3409 		/* Slab must be on the full list */
3410 		remove_full(s, n, slab);
3411 	}
3412 
3413 	spin_unlock_irqrestore(&n->list_lock, flags);
3414 	stat(s, FREE_SLAB);
3415 	discard_slab(s, slab);
3416 }
3417 
3418 /*
3419  * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
3420  * can perform fastpath freeing without additional function calls.
3421  *
3422  * The fastpath is only possible if we are freeing to the current cpu slab
3423  * of this processor. This typically the case if we have just allocated
3424  * the item before.
3425  *
3426  * If fastpath is not possible then fall back to __slab_free where we deal
3427  * with all sorts of special processing.
3428  *
3429  * Bulk free of a freelist with several objects (all pointing to the
3430  * same slab) possible by specifying head and tail ptr, plus objects
3431  * count (cnt). Bulk free indicated by tail pointer being set.
3432  */
3433 static __always_inline void do_slab_free(struct kmem_cache *s,
3434 				struct slab *slab, void *head, void *tail,
3435 				int cnt, unsigned long addr)
3436 {
3437 	void *tail_obj = tail ? : head;
3438 	struct kmem_cache_cpu *c;
3439 	unsigned long tid;
3440 
3441 	/* memcg_slab_free_hook() is already called for bulk free. */
3442 	if (!tail)
3443 		memcg_slab_free_hook(s, &head, 1);
3444 redo:
3445 	/*
3446 	 * Determine the currently cpus per cpu slab.
3447 	 * The cpu may change afterward. However that does not matter since
3448 	 * data is retrieved via this pointer. If we are on the same cpu
3449 	 * during the cmpxchg then the free will succeed.
3450 	 */
3451 	c = raw_cpu_ptr(s->cpu_slab);
3452 	tid = READ_ONCE(c->tid);
3453 
3454 	/* Same with comment on barrier() in slab_alloc_node() */
3455 	barrier();
3456 
3457 	if (likely(slab == c->slab)) {
3458 #ifndef CONFIG_PREEMPT_RT
3459 		void **freelist = READ_ONCE(c->freelist);
3460 
3461 		set_freepointer(s, tail_obj, freelist);
3462 
3463 		if (unlikely(!this_cpu_cmpxchg_double(
3464 				s->cpu_slab->freelist, s->cpu_slab->tid,
3465 				freelist, tid,
3466 				head, next_tid(tid)))) {
3467 
3468 			note_cmpxchg_failure("slab_free", s, tid);
3469 			goto redo;
3470 		}
3471 #else /* CONFIG_PREEMPT_RT */
3472 		/*
3473 		 * We cannot use the lockless fastpath on PREEMPT_RT because if
3474 		 * a slowpath has taken the local_lock_irqsave(), it is not
3475 		 * protected against a fast path operation in an irq handler. So
3476 		 * we need to take the local_lock. We shouldn't simply defer to
3477 		 * __slab_free() as that wouldn't use the cpu freelist at all.
3478 		 */
3479 		void **freelist;
3480 
3481 		local_lock(&s->cpu_slab->lock);
3482 		c = this_cpu_ptr(s->cpu_slab);
3483 		if (unlikely(slab != c->slab)) {
3484 			local_unlock(&s->cpu_slab->lock);
3485 			goto redo;
3486 		}
3487 		tid = c->tid;
3488 		freelist = c->freelist;
3489 
3490 		set_freepointer(s, tail_obj, freelist);
3491 		c->freelist = head;
3492 		c->tid = next_tid(tid);
3493 
3494 		local_unlock(&s->cpu_slab->lock);
3495 #endif
3496 		stat(s, FREE_FASTPATH);
3497 	} else
3498 		__slab_free(s, slab, head, tail_obj, cnt, addr);
3499 
3500 }
3501 
3502 static __always_inline void slab_free(struct kmem_cache *s, struct slab *slab,
3503 				      void *head, void *tail, int cnt,
3504 				      unsigned long addr)
3505 {
3506 	/*
3507 	 * With KASAN enabled slab_free_freelist_hook modifies the freelist
3508 	 * to remove objects, whose reuse must be delayed.
3509 	 */
3510 	if (slab_free_freelist_hook(s, &head, &tail, &cnt))
3511 		do_slab_free(s, slab, head, tail, cnt, addr);
3512 }
3513 
3514 #ifdef CONFIG_KASAN_GENERIC
3515 void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr)
3516 {
3517 	do_slab_free(cache, virt_to_slab(x), x, NULL, 1, addr);
3518 }
3519 #endif
3520 
3521 void kmem_cache_free(struct kmem_cache *s, void *x)
3522 {
3523 	s = cache_from_obj(s, x);
3524 	if (!s)
3525 		return;
3526 	trace_kmem_cache_free(_RET_IP_, x, s->name);
3527 	slab_free(s, virt_to_slab(x), x, NULL, 1, _RET_IP_);
3528 }
3529 EXPORT_SYMBOL(kmem_cache_free);
3530 
3531 struct detached_freelist {
3532 	struct slab *slab;
3533 	void *tail;
3534 	void *freelist;
3535 	int cnt;
3536 	struct kmem_cache *s;
3537 };
3538 
3539 static inline void free_large_kmalloc(struct folio *folio, void *object)
3540 {
3541 	unsigned int order = folio_order(folio);
3542 
3543 	if (WARN_ON_ONCE(order == 0))
3544 		pr_warn_once("object pointer: 0x%p\n", object);
3545 
3546 	kfree_hook(object);
3547 	mod_lruvec_page_state(folio_page(folio, 0), NR_SLAB_UNRECLAIMABLE_B,
3548 			      -(PAGE_SIZE << order));
3549 	__free_pages(folio_page(folio, 0), order);
3550 }
3551 
3552 /*
3553  * This function progressively scans the array with free objects (with
3554  * a limited look ahead) and extract objects belonging to the same
3555  * slab.  It builds a detached freelist directly within the given
3556  * slab/objects.  This can happen without any need for
3557  * synchronization, because the objects are owned by running process.
3558  * The freelist is build up as a single linked list in the objects.
3559  * The idea is, that this detached freelist can then be bulk
3560  * transferred to the real freelist(s), but only requiring a single
3561  * synchronization primitive.  Look ahead in the array is limited due
3562  * to performance reasons.
3563  */
3564 static inline
3565 int build_detached_freelist(struct kmem_cache *s, size_t size,
3566 			    void **p, struct detached_freelist *df)
3567 {
3568 	size_t first_skipped_index = 0;
3569 	int lookahead = 3;
3570 	void *object;
3571 	struct folio *folio;
3572 	struct slab *slab;
3573 
3574 	/* Always re-init detached_freelist */
3575 	df->slab = NULL;
3576 
3577 	do {
3578 		object = p[--size];
3579 		/* Do we need !ZERO_OR_NULL_PTR(object) here? (for kfree) */
3580 	} while (!object && size);
3581 
3582 	if (!object)
3583 		return 0;
3584 
3585 	folio = virt_to_folio(object);
3586 	if (!s) {
3587 		/* Handle kalloc'ed objects */
3588 		if (unlikely(!folio_test_slab(folio))) {
3589 			free_large_kmalloc(folio, object);
3590 			p[size] = NULL; /* mark object processed */
3591 			return size;
3592 		}
3593 		/* Derive kmem_cache from object */
3594 		slab = folio_slab(folio);
3595 		df->s = slab->slab_cache;
3596 	} else {
3597 		slab = folio_slab(folio);
3598 		df->s = cache_from_obj(s, object); /* Support for memcg */
3599 	}
3600 
3601 	if (is_kfence_address(object)) {
3602 		slab_free_hook(df->s, object, false);
3603 		__kfence_free(object);
3604 		p[size] = NULL; /* mark object processed */
3605 		return size;
3606 	}
3607 
3608 	/* Start new detached freelist */
3609 	df->slab = slab;
3610 	set_freepointer(df->s, object, NULL);
3611 	df->tail = object;
3612 	df->freelist = object;
3613 	p[size] = NULL; /* mark object processed */
3614 	df->cnt = 1;
3615 
3616 	while (size) {
3617 		object = p[--size];
3618 		if (!object)
3619 			continue; /* Skip processed objects */
3620 
3621 		/* df->slab is always set at this point */
3622 		if (df->slab == virt_to_slab(object)) {
3623 			/* Opportunity build freelist */
3624 			set_freepointer(df->s, object, df->freelist);
3625 			df->freelist = object;
3626 			df->cnt++;
3627 			p[size] = NULL; /* mark object processed */
3628 
3629 			continue;
3630 		}
3631 
3632 		/* Limit look ahead search */
3633 		if (!--lookahead)
3634 			break;
3635 
3636 		if (!first_skipped_index)
3637 			first_skipped_index = size + 1;
3638 	}
3639 
3640 	return first_skipped_index;
3641 }
3642 
3643 /* Note that interrupts must be enabled when calling this function. */
3644 void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
3645 {
3646 	if (WARN_ON(!size))
3647 		return;
3648 
3649 	memcg_slab_free_hook(s, p, size);
3650 	do {
3651 		struct detached_freelist df;
3652 
3653 		size = build_detached_freelist(s, size, p, &df);
3654 		if (!df.slab)
3655 			continue;
3656 
3657 		slab_free(df.s, df.slab, df.freelist, df.tail, df.cnt, _RET_IP_);
3658 	} while (likely(size));
3659 }
3660 EXPORT_SYMBOL(kmem_cache_free_bulk);
3661 
3662 /* Note that interrupts must be enabled when calling this function. */
3663 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
3664 			  void **p)
3665 {
3666 	struct kmem_cache_cpu *c;
3667 	int i;
3668 	struct obj_cgroup *objcg = NULL;
3669 
3670 	/* memcg and kmem_cache debug support */
3671 	s = slab_pre_alloc_hook(s, NULL, &objcg, size, flags);
3672 	if (unlikely(!s))
3673 		return false;
3674 	/*
3675 	 * Drain objects in the per cpu slab, while disabling local
3676 	 * IRQs, which protects against PREEMPT and interrupts
3677 	 * handlers invoking normal fastpath.
3678 	 */
3679 	c = slub_get_cpu_ptr(s->cpu_slab);
3680 	local_lock_irq(&s->cpu_slab->lock);
3681 
3682 	for (i = 0; i < size; i++) {
3683 		void *object = kfence_alloc(s, s->object_size, flags);
3684 
3685 		if (unlikely(object)) {
3686 			p[i] = object;
3687 			continue;
3688 		}
3689 
3690 		object = c->freelist;
3691 		if (unlikely(!object)) {
3692 			/*
3693 			 * We may have removed an object from c->freelist using
3694 			 * the fastpath in the previous iteration; in that case,
3695 			 * c->tid has not been bumped yet.
3696 			 * Since ___slab_alloc() may reenable interrupts while
3697 			 * allocating memory, we should bump c->tid now.
3698 			 */
3699 			c->tid = next_tid(c->tid);
3700 
3701 			local_unlock_irq(&s->cpu_slab->lock);
3702 
3703 			/*
3704 			 * Invoking slow path likely have side-effect
3705 			 * of re-populating per CPU c->freelist
3706 			 */
3707 			p[i] = ___slab_alloc(s, flags, NUMA_NO_NODE,
3708 					    _RET_IP_, c);
3709 			if (unlikely(!p[i]))
3710 				goto error;
3711 
3712 			c = this_cpu_ptr(s->cpu_slab);
3713 			maybe_wipe_obj_freeptr(s, p[i]);
3714 
3715 			local_lock_irq(&s->cpu_slab->lock);
3716 
3717 			continue; /* goto for-loop */
3718 		}
3719 		c->freelist = get_freepointer(s, object);
3720 		p[i] = object;
3721 		maybe_wipe_obj_freeptr(s, p[i]);
3722 	}
3723 	c->tid = next_tid(c->tid);
3724 	local_unlock_irq(&s->cpu_slab->lock);
3725 	slub_put_cpu_ptr(s->cpu_slab);
3726 
3727 	/*
3728 	 * memcg and kmem_cache debug support and memory initialization.
3729 	 * Done outside of the IRQ disabled fastpath loop.
3730 	 */
3731 	slab_post_alloc_hook(s, objcg, flags, size, p,
3732 				slab_want_init_on_alloc(flags, s));
3733 	return i;
3734 error:
3735 	slub_put_cpu_ptr(s->cpu_slab);
3736 	slab_post_alloc_hook(s, objcg, flags, i, p, false);
3737 	__kmem_cache_free_bulk(s, i, p);
3738 	return 0;
3739 }
3740 EXPORT_SYMBOL(kmem_cache_alloc_bulk);
3741 
3742 
3743 /*
3744  * Object placement in a slab is made very easy because we always start at
3745  * offset 0. If we tune the size of the object to the alignment then we can
3746  * get the required alignment by putting one properly sized object after
3747  * another.
3748  *
3749  * Notice that the allocation order determines the sizes of the per cpu
3750  * caches. Each processor has always one slab available for allocations.
3751  * Increasing the allocation order reduces the number of times that slabs
3752  * must be moved on and off the partial lists and is therefore a factor in
3753  * locking overhead.
3754  */
3755 
3756 /*
3757  * Minimum / Maximum order of slab pages. This influences locking overhead
3758  * and slab fragmentation. A higher order reduces the number of partial slabs
3759  * and increases the number of allocations possible without having to
3760  * take the list_lock.
3761  */
3762 static unsigned int slub_min_order;
3763 static unsigned int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
3764 static unsigned int slub_min_objects;
3765 
3766 /*
3767  * Calculate the order of allocation given an slab object size.
3768  *
3769  * The order of allocation has significant impact on performance and other
3770  * system components. Generally order 0 allocations should be preferred since
3771  * order 0 does not cause fragmentation in the page allocator. Larger objects
3772  * be problematic to put into order 0 slabs because there may be too much
3773  * unused space left. We go to a higher order if more than 1/16th of the slab
3774  * would be wasted.
3775  *
3776  * In order to reach satisfactory performance we must ensure that a minimum
3777  * number of objects is in one slab. Otherwise we may generate too much
3778  * activity on the partial lists which requires taking the list_lock. This is
3779  * less a concern for large slabs though which are rarely used.
3780  *
3781  * slub_max_order specifies the order where we begin to stop considering the
3782  * number of objects in a slab as critical. If we reach slub_max_order then
3783  * we try to keep the page order as low as possible. So we accept more waste
3784  * of space in favor of a small page order.
3785  *
3786  * Higher order allocations also allow the placement of more objects in a
3787  * slab and thereby reduce object handling overhead. If the user has
3788  * requested a higher minimum order then we start with that one instead of
3789  * the smallest order which will fit the object.
3790  */
3791 static inline unsigned int calc_slab_order(unsigned int size,
3792 		unsigned int min_objects, unsigned int max_order,
3793 		unsigned int fract_leftover)
3794 {
3795 	unsigned int min_order = slub_min_order;
3796 	unsigned int order;
3797 
3798 	if (order_objects(min_order, size) > MAX_OBJS_PER_PAGE)
3799 		return get_order(size * MAX_OBJS_PER_PAGE) - 1;
3800 
3801 	for (order = max(min_order, (unsigned int)get_order(min_objects * size));
3802 			order <= max_order; order++) {
3803 
3804 		unsigned int slab_size = (unsigned int)PAGE_SIZE << order;
3805 		unsigned int rem;
3806 
3807 		rem = slab_size % size;
3808 
3809 		if (rem <= slab_size / fract_leftover)
3810 			break;
3811 	}
3812 
3813 	return order;
3814 }
3815 
3816 static inline int calculate_order(unsigned int size)
3817 {
3818 	unsigned int order;
3819 	unsigned int min_objects;
3820 	unsigned int max_objects;
3821 	unsigned int nr_cpus;
3822 
3823 	/*
3824 	 * Attempt to find best configuration for a slab. This
3825 	 * works by first attempting to generate a layout with
3826 	 * the best configuration and backing off gradually.
3827 	 *
3828 	 * First we increase the acceptable waste in a slab. Then
3829 	 * we reduce the minimum objects required in a slab.
3830 	 */
3831 	min_objects = slub_min_objects;
3832 	if (!min_objects) {
3833 		/*
3834 		 * Some architectures will only update present cpus when
3835 		 * onlining them, so don't trust the number if it's just 1. But
3836 		 * we also don't want to use nr_cpu_ids always, as on some other
3837 		 * architectures, there can be many possible cpus, but never
3838 		 * onlined. Here we compromise between trying to avoid too high
3839 		 * order on systems that appear larger than they are, and too
3840 		 * low order on systems that appear smaller than they are.
3841 		 */
3842 		nr_cpus = num_present_cpus();
3843 		if (nr_cpus <= 1)
3844 			nr_cpus = nr_cpu_ids;
3845 		min_objects = 4 * (fls(nr_cpus) + 1);
3846 	}
3847 	max_objects = order_objects(slub_max_order, size);
3848 	min_objects = min(min_objects, max_objects);
3849 
3850 	while (min_objects > 1) {
3851 		unsigned int fraction;
3852 
3853 		fraction = 16;
3854 		while (fraction >= 4) {
3855 			order = calc_slab_order(size, min_objects,
3856 					slub_max_order, fraction);
3857 			if (order <= slub_max_order)
3858 				return order;
3859 			fraction /= 2;
3860 		}
3861 		min_objects--;
3862 	}
3863 
3864 	/*
3865 	 * We were unable to place multiple objects in a slab. Now
3866 	 * lets see if we can place a single object there.
3867 	 */
3868 	order = calc_slab_order(size, 1, slub_max_order, 1);
3869 	if (order <= slub_max_order)
3870 		return order;
3871 
3872 	/*
3873 	 * Doh this slab cannot be placed using slub_max_order.
3874 	 */
3875 	order = calc_slab_order(size, 1, MAX_ORDER, 1);
3876 	if (order < MAX_ORDER)
3877 		return order;
3878 	return -ENOSYS;
3879 }
3880 
3881 static void
3882 init_kmem_cache_node(struct kmem_cache_node *n)
3883 {
3884 	n->nr_partial = 0;
3885 	spin_lock_init(&n->list_lock);
3886 	INIT_LIST_HEAD(&n->partial);
3887 #ifdef CONFIG_SLUB_DEBUG
3888 	atomic_long_set(&n->nr_slabs, 0);
3889 	atomic_long_set(&n->total_objects, 0);
3890 	INIT_LIST_HEAD(&n->full);
3891 #endif
3892 }
3893 
3894 static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
3895 {
3896 	BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
3897 			KMALLOC_SHIFT_HIGH * sizeof(struct kmem_cache_cpu));
3898 
3899 	/*
3900 	 * Must align to double word boundary for the double cmpxchg
3901 	 * instructions to work; see __pcpu_double_call_return_bool().
3902 	 */
3903 	s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu),
3904 				     2 * sizeof(void *));
3905 
3906 	if (!s->cpu_slab)
3907 		return 0;
3908 
3909 	init_kmem_cache_cpus(s);
3910 
3911 	return 1;
3912 }
3913 
3914 static struct kmem_cache *kmem_cache_node;
3915 
3916 /*
3917  * No kmalloc_node yet so do it by hand. We know that this is the first
3918  * slab on the node for this slabcache. There are no concurrent accesses
3919  * possible.
3920  *
3921  * Note that this function only works on the kmem_cache_node
3922  * when allocating for the kmem_cache_node. This is used for bootstrapping
3923  * memory on a fresh node that has no slab structures yet.
3924  */
3925 static void early_kmem_cache_node_alloc(int node)
3926 {
3927 	struct slab *slab;
3928 	struct kmem_cache_node *n;
3929 
3930 	BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
3931 
3932 	slab = new_slab(kmem_cache_node, GFP_NOWAIT, node);
3933 
3934 	BUG_ON(!slab);
3935 	if (slab_nid(slab) != node) {
3936 		pr_err("SLUB: Unable to allocate memory from node %d\n", node);
3937 		pr_err("SLUB: Allocating a useless per node structure in order to be able to continue\n");
3938 	}
3939 
3940 	n = slab->freelist;
3941 	BUG_ON(!n);
3942 #ifdef CONFIG_SLUB_DEBUG
3943 	init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
3944 	init_tracking(kmem_cache_node, n);
3945 #endif
3946 	n = kasan_slab_alloc(kmem_cache_node, n, GFP_KERNEL, false);
3947 	slab->freelist = get_freepointer(kmem_cache_node, n);
3948 	slab->inuse = 1;
3949 	slab->frozen = 0;
3950 	kmem_cache_node->node[node] = n;
3951 	init_kmem_cache_node(n);
3952 	inc_slabs_node(kmem_cache_node, node, slab->objects);
3953 
3954 	/*
3955 	 * No locks need to be taken here as it has just been
3956 	 * initialized and there is no concurrent access.
3957 	 */
3958 	__add_partial(n, slab, DEACTIVATE_TO_HEAD);
3959 }
3960 
3961 static void free_kmem_cache_nodes(struct kmem_cache *s)
3962 {
3963 	int node;
3964 	struct kmem_cache_node *n;
3965 
3966 	for_each_kmem_cache_node(s, node, n) {
3967 		s->node[node] = NULL;
3968 		kmem_cache_free(kmem_cache_node, n);
3969 	}
3970 }
3971 
3972 void __kmem_cache_release(struct kmem_cache *s)
3973 {
3974 	cache_random_seq_destroy(s);
3975 	free_percpu(s->cpu_slab);
3976 	free_kmem_cache_nodes(s);
3977 }
3978 
3979 static int init_kmem_cache_nodes(struct kmem_cache *s)
3980 {
3981 	int node;
3982 
3983 	for_each_node_mask(node, slab_nodes) {
3984 		struct kmem_cache_node *n;
3985 
3986 		if (slab_state == DOWN) {
3987 			early_kmem_cache_node_alloc(node);
3988 			continue;
3989 		}
3990 		n = kmem_cache_alloc_node(kmem_cache_node,
3991 						GFP_KERNEL, node);
3992 
3993 		if (!n) {
3994 			free_kmem_cache_nodes(s);
3995 			return 0;
3996 		}
3997 
3998 		init_kmem_cache_node(n);
3999 		s->node[node] = n;
4000 	}
4001 	return 1;
4002 }
4003 
4004 static void set_cpu_partial(struct kmem_cache *s)
4005 {
4006 #ifdef CONFIG_SLUB_CPU_PARTIAL
4007 	unsigned int nr_objects;
4008 
4009 	/*
4010 	 * cpu_partial determined the maximum number of objects kept in the
4011 	 * per cpu partial lists of a processor.
4012 	 *
4013 	 * Per cpu partial lists mainly contain slabs that just have one
4014 	 * object freed. If they are used for allocation then they can be
4015 	 * filled up again with minimal effort. The slab will never hit the
4016 	 * per node partial lists and therefore no locking will be required.
4017 	 *
4018 	 * For backwards compatibility reasons, this is determined as number
4019 	 * of objects, even though we now limit maximum number of pages, see
4020 	 * slub_set_cpu_partial()
4021 	 */
4022 	if (!kmem_cache_has_cpu_partial(s))
4023 		nr_objects = 0;
4024 	else if (s->size >= PAGE_SIZE)
4025 		nr_objects = 6;
4026 	else if (s->size >= 1024)
4027 		nr_objects = 24;
4028 	else if (s->size >= 256)
4029 		nr_objects = 52;
4030 	else
4031 		nr_objects = 120;
4032 
4033 	slub_set_cpu_partial(s, nr_objects);
4034 #endif
4035 }
4036 
4037 /*
4038  * calculate_sizes() determines the order and the distribution of data within
4039  * a slab object.
4040  */
4041 static int calculate_sizes(struct kmem_cache *s)
4042 {
4043 	slab_flags_t flags = s->flags;
4044 	unsigned int size = s->object_size;
4045 	unsigned int order;
4046 
4047 	/*
4048 	 * Round up object size to the next word boundary. We can only
4049 	 * place the free pointer at word boundaries and this determines
4050 	 * the possible location of the free pointer.
4051 	 */
4052 	size = ALIGN(size, sizeof(void *));
4053 
4054 #ifdef CONFIG_SLUB_DEBUG
4055 	/*
4056 	 * Determine if we can poison the object itself. If the user of
4057 	 * the slab may touch the object after free or before allocation
4058 	 * then we should never poison the object itself.
4059 	 */
4060 	if ((flags & SLAB_POISON) && !(flags & SLAB_TYPESAFE_BY_RCU) &&
4061 			!s->ctor)
4062 		s->flags |= __OBJECT_POISON;
4063 	else
4064 		s->flags &= ~__OBJECT_POISON;
4065 
4066 
4067 	/*
4068 	 * If we are Redzoning then check if there is some space between the
4069 	 * end of the object and the free pointer. If not then add an
4070 	 * additional word to have some bytes to store Redzone information.
4071 	 */
4072 	if ((flags & SLAB_RED_ZONE) && size == s->object_size)
4073 		size += sizeof(void *);
4074 #endif
4075 
4076 	/*
4077 	 * With that we have determined the number of bytes in actual use
4078 	 * by the object and redzoning.
4079 	 */
4080 	s->inuse = size;
4081 
4082 	if ((flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) ||
4083 	    ((flags & SLAB_RED_ZONE) && s->object_size < sizeof(void *)) ||
4084 	    s->ctor) {
4085 		/*
4086 		 * Relocate free pointer after the object if it is not
4087 		 * permitted to overwrite the first word of the object on
4088 		 * kmem_cache_free.
4089 		 *
4090 		 * This is the case if we do RCU, have a constructor or
4091 		 * destructor, are poisoning the objects, or are
4092 		 * redzoning an object smaller than sizeof(void *).
4093 		 *
4094 		 * The assumption that s->offset >= s->inuse means free
4095 		 * pointer is outside of the object is used in the
4096 		 * freeptr_outside_object() function. If that is no
4097 		 * longer true, the function needs to be modified.
4098 		 */
4099 		s->offset = size;
4100 		size += sizeof(void *);
4101 	} else {
4102 		/*
4103 		 * Store freelist pointer near middle of object to keep
4104 		 * it away from the edges of the object to avoid small
4105 		 * sized over/underflows from neighboring allocations.
4106 		 */
4107 		s->offset = ALIGN_DOWN(s->object_size / 2, sizeof(void *));
4108 	}
4109 
4110 #ifdef CONFIG_SLUB_DEBUG
4111 	if (flags & SLAB_STORE_USER)
4112 		/*
4113 		 * Need to store information about allocs and frees after
4114 		 * the object.
4115 		 */
4116 		size += 2 * sizeof(struct track);
4117 #endif
4118 
4119 	kasan_cache_create(s, &size, &s->flags);
4120 #ifdef CONFIG_SLUB_DEBUG
4121 	if (flags & SLAB_RED_ZONE) {
4122 		/*
4123 		 * Add some empty padding so that we can catch
4124 		 * overwrites from earlier objects rather than let
4125 		 * tracking information or the free pointer be
4126 		 * corrupted if a user writes before the start
4127 		 * of the object.
4128 		 */
4129 		size += sizeof(void *);
4130 
4131 		s->red_left_pad = sizeof(void *);
4132 		s->red_left_pad = ALIGN(s->red_left_pad, s->align);
4133 		size += s->red_left_pad;
4134 	}
4135 #endif
4136 
4137 	/*
4138 	 * SLUB stores one object immediately after another beginning from
4139 	 * offset 0. In order to align the objects we have to simply size
4140 	 * each object to conform to the alignment.
4141 	 */
4142 	size = ALIGN(size, s->align);
4143 	s->size = size;
4144 	s->reciprocal_size = reciprocal_value(size);
4145 	order = calculate_order(size);
4146 
4147 	if ((int)order < 0)
4148 		return 0;
4149 
4150 	s->allocflags = 0;
4151 	if (order)
4152 		s->allocflags |= __GFP_COMP;
4153 
4154 	if (s->flags & SLAB_CACHE_DMA)
4155 		s->allocflags |= GFP_DMA;
4156 
4157 	if (s->flags & SLAB_CACHE_DMA32)
4158 		s->allocflags |= GFP_DMA32;
4159 
4160 	if (s->flags & SLAB_RECLAIM_ACCOUNT)
4161 		s->allocflags |= __GFP_RECLAIMABLE;
4162 
4163 	/*
4164 	 * Determine the number of objects per slab
4165 	 */
4166 	s->oo = oo_make(order, size);
4167 	s->min = oo_make(get_order(size), size);
4168 	if (oo_objects(s->oo) > oo_objects(s->max))
4169 		s->max = s->oo;
4170 
4171 	return !!oo_objects(s->oo);
4172 }
4173 
4174 static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags)
4175 {
4176 	s->flags = kmem_cache_flags(s->size, flags, s->name);
4177 #ifdef CONFIG_SLAB_FREELIST_HARDENED
4178 	s->random = get_random_long();
4179 #endif
4180 
4181 	if (!calculate_sizes(s))
4182 		goto error;
4183 	if (disable_higher_order_debug) {
4184 		/*
4185 		 * Disable debugging flags that store metadata if the min slab
4186 		 * order increased.
4187 		 */
4188 		if (get_order(s->size) > get_order(s->object_size)) {
4189 			s->flags &= ~DEBUG_METADATA_FLAGS;
4190 			s->offset = 0;
4191 			if (!calculate_sizes(s))
4192 				goto error;
4193 		}
4194 	}
4195 
4196 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
4197     defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
4198 	if (system_has_cmpxchg_double() && (s->flags & SLAB_NO_CMPXCHG) == 0)
4199 		/* Enable fast mode */
4200 		s->flags |= __CMPXCHG_DOUBLE;
4201 #endif
4202 
4203 	/*
4204 	 * The larger the object size is, the more slabs we want on the partial
4205 	 * list to avoid pounding the page allocator excessively.
4206 	 */
4207 	s->min_partial = min_t(unsigned long, MAX_PARTIAL, ilog2(s->size) / 2);
4208 	s->min_partial = max_t(unsigned long, MIN_PARTIAL, s->min_partial);
4209 
4210 	set_cpu_partial(s);
4211 
4212 #ifdef CONFIG_NUMA
4213 	s->remote_node_defrag_ratio = 1000;
4214 #endif
4215 
4216 	/* Initialize the pre-computed randomized freelist if slab is up */
4217 	if (slab_state >= UP) {
4218 		if (init_cache_random_seq(s))
4219 			goto error;
4220 	}
4221 
4222 	if (!init_kmem_cache_nodes(s))
4223 		goto error;
4224 
4225 	if (alloc_kmem_cache_cpus(s))
4226 		return 0;
4227 
4228 error:
4229 	__kmem_cache_release(s);
4230 	return -EINVAL;
4231 }
4232 
4233 static void list_slab_objects(struct kmem_cache *s, struct slab *slab,
4234 			      const char *text)
4235 {
4236 #ifdef CONFIG_SLUB_DEBUG
4237 	void *addr = slab_address(slab);
4238 	unsigned long flags;
4239 	unsigned long *map;
4240 	void *p;
4241 
4242 	slab_err(s, slab, text, s->name);
4243 	slab_lock(slab, &flags);
4244 
4245 	map = get_map(s, slab);
4246 	for_each_object(p, s, addr, slab->objects) {
4247 
4248 		if (!test_bit(__obj_to_index(s, addr, p), map)) {
4249 			pr_err("Object 0x%p @offset=%tu\n", p, p - addr);
4250 			print_tracking(s, p);
4251 		}
4252 	}
4253 	put_map(map);
4254 	slab_unlock(slab, &flags);
4255 #endif
4256 }
4257 
4258 /*
4259  * Attempt to free all partial slabs on a node.
4260  * This is called from __kmem_cache_shutdown(). We must take list_lock
4261  * because sysfs file might still access partial list after the shutdowning.
4262  */
4263 static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
4264 {
4265 	LIST_HEAD(discard);
4266 	struct slab *slab, *h;
4267 
4268 	BUG_ON(irqs_disabled());
4269 	spin_lock_irq(&n->list_lock);
4270 	list_for_each_entry_safe(slab, h, &n->partial, slab_list) {
4271 		if (!slab->inuse) {
4272 			remove_partial(n, slab);
4273 			list_add(&slab->slab_list, &discard);
4274 		} else {
4275 			list_slab_objects(s, slab,
4276 			  "Objects remaining in %s on __kmem_cache_shutdown()");
4277 		}
4278 	}
4279 	spin_unlock_irq(&n->list_lock);
4280 
4281 	list_for_each_entry_safe(slab, h, &discard, slab_list)
4282 		discard_slab(s, slab);
4283 }
4284 
4285 bool __kmem_cache_empty(struct kmem_cache *s)
4286 {
4287 	int node;
4288 	struct kmem_cache_node *n;
4289 
4290 	for_each_kmem_cache_node(s, node, n)
4291 		if (n->nr_partial || slabs_node(s, node))
4292 			return false;
4293 	return true;
4294 }
4295 
4296 /*
4297  * Release all resources used by a slab cache.
4298  */
4299 int __kmem_cache_shutdown(struct kmem_cache *s)
4300 {
4301 	int node;
4302 	struct kmem_cache_node *n;
4303 
4304 	flush_all_cpus_locked(s);
4305 	/* Attempt to free all objects */
4306 	for_each_kmem_cache_node(s, node, n) {
4307 		free_partial(s, n);
4308 		if (n->nr_partial || slabs_node(s, node))
4309 			return 1;
4310 	}
4311 	return 0;
4312 }
4313 
4314 #ifdef CONFIG_PRINTK
4315 void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
4316 {
4317 	void *base;
4318 	int __maybe_unused i;
4319 	unsigned int objnr;
4320 	void *objp;
4321 	void *objp0;
4322 	struct kmem_cache *s = slab->slab_cache;
4323 	struct track __maybe_unused *trackp;
4324 
4325 	kpp->kp_ptr = object;
4326 	kpp->kp_slab = slab;
4327 	kpp->kp_slab_cache = s;
4328 	base = slab_address(slab);
4329 	objp0 = kasan_reset_tag(object);
4330 #ifdef CONFIG_SLUB_DEBUG
4331 	objp = restore_red_left(s, objp0);
4332 #else
4333 	objp = objp0;
4334 #endif
4335 	objnr = obj_to_index(s, slab, objp);
4336 	kpp->kp_data_offset = (unsigned long)((char *)objp0 - (char *)objp);
4337 	objp = base + s->size * objnr;
4338 	kpp->kp_objp = objp;
4339 	if (WARN_ON_ONCE(objp < base || objp >= base + slab->objects * s->size
4340 			 || (objp - base) % s->size) ||
4341 	    !(s->flags & SLAB_STORE_USER))
4342 		return;
4343 #ifdef CONFIG_SLUB_DEBUG
4344 	objp = fixup_red_left(s, objp);
4345 	trackp = get_track(s, objp, TRACK_ALLOC);
4346 	kpp->kp_ret = (void *)trackp->addr;
4347 #ifdef CONFIG_STACKTRACE
4348 	for (i = 0; i < KS_ADDRS_COUNT && i < TRACK_ADDRS_COUNT; i++) {
4349 		kpp->kp_stack[i] = (void *)trackp->addrs[i];
4350 		if (!kpp->kp_stack[i])
4351 			break;
4352 	}
4353 
4354 	trackp = get_track(s, objp, TRACK_FREE);
4355 	for (i = 0; i < KS_ADDRS_COUNT && i < TRACK_ADDRS_COUNT; i++) {
4356 		kpp->kp_free_stack[i] = (void *)trackp->addrs[i];
4357 		if (!kpp->kp_free_stack[i])
4358 			break;
4359 	}
4360 #endif
4361 #endif
4362 }
4363 #endif
4364 
4365 /********************************************************************
4366  *		Kmalloc subsystem
4367  *******************************************************************/
4368 
4369 static int __init setup_slub_min_order(char *str)
4370 {
4371 	get_option(&str, (int *)&slub_min_order);
4372 
4373 	return 1;
4374 }
4375 
4376 __setup("slub_min_order=", setup_slub_min_order);
4377 
4378 static int __init setup_slub_max_order(char *str)
4379 {
4380 	get_option(&str, (int *)&slub_max_order);
4381 	slub_max_order = min(slub_max_order, (unsigned int)MAX_ORDER - 1);
4382 
4383 	return 1;
4384 }
4385 
4386 __setup("slub_max_order=", setup_slub_max_order);
4387 
4388 static int __init setup_slub_min_objects(char *str)
4389 {
4390 	get_option(&str, (int *)&slub_min_objects);
4391 
4392 	return 1;
4393 }
4394 
4395 __setup("slub_min_objects=", setup_slub_min_objects);
4396 
4397 void *__kmalloc(size_t size, gfp_t flags)
4398 {
4399 	struct kmem_cache *s;
4400 	void *ret;
4401 
4402 	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
4403 		return kmalloc_large(size, flags);
4404 
4405 	s = kmalloc_slab(size, flags);
4406 
4407 	if (unlikely(ZERO_OR_NULL_PTR(s)))
4408 		return s;
4409 
4410 	ret = slab_alloc(s, NULL, flags, _RET_IP_, size);
4411 
4412 	trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
4413 
4414 	ret = kasan_kmalloc(s, ret, size, flags);
4415 
4416 	return ret;
4417 }
4418 EXPORT_SYMBOL(__kmalloc);
4419 
4420 #ifdef CONFIG_NUMA
4421 static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
4422 {
4423 	struct page *page;
4424 	void *ptr = NULL;
4425 	unsigned int order = get_order(size);
4426 
4427 	flags |= __GFP_COMP;
4428 	page = alloc_pages_node(node, flags, order);
4429 	if (page) {
4430 		ptr = page_address(page);
4431 		mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B,
4432 				      PAGE_SIZE << order);
4433 	}
4434 
4435 	return kmalloc_large_node_hook(ptr, size, flags);
4436 }
4437 
4438 void *__kmalloc_node(size_t size, gfp_t flags, int node)
4439 {
4440 	struct kmem_cache *s;
4441 	void *ret;
4442 
4443 	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
4444 		ret = kmalloc_large_node(size, flags, node);
4445 
4446 		trace_kmalloc_node(_RET_IP_, ret,
4447 				   size, PAGE_SIZE << get_order(size),
4448 				   flags, node);
4449 
4450 		return ret;
4451 	}
4452 
4453 	s = kmalloc_slab(size, flags);
4454 
4455 	if (unlikely(ZERO_OR_NULL_PTR(s)))
4456 		return s;
4457 
4458 	ret = slab_alloc_node(s, NULL, flags, node, _RET_IP_, size);
4459 
4460 	trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
4461 
4462 	ret = kasan_kmalloc(s, ret, size, flags);
4463 
4464 	return ret;
4465 }
4466 EXPORT_SYMBOL(__kmalloc_node);
4467 #endif	/* CONFIG_NUMA */
4468 
4469 #ifdef CONFIG_HARDENED_USERCOPY
4470 /*
4471  * Rejects incorrectly sized objects and objects that are to be copied
4472  * to/from userspace but do not fall entirely within the containing slab
4473  * cache's usercopy region.
4474  *
4475  * Returns NULL if check passes, otherwise const char * to name of cache
4476  * to indicate an error.
4477  */
4478 void __check_heap_object(const void *ptr, unsigned long n,
4479 			 const struct slab *slab, bool to_user)
4480 {
4481 	struct kmem_cache *s;
4482 	unsigned int offset;
4483 	bool is_kfence = is_kfence_address(ptr);
4484 
4485 	ptr = kasan_reset_tag(ptr);
4486 
4487 	/* Find object and usable object size. */
4488 	s = slab->slab_cache;
4489 
4490 	/* Reject impossible pointers. */
4491 	if (ptr < slab_address(slab))
4492 		usercopy_abort("SLUB object not in SLUB page?!", NULL,
4493 			       to_user, 0, n);
4494 
4495 	/* Find offset within object. */
4496 	if (is_kfence)
4497 		offset = ptr - kfence_object_start(ptr);
4498 	else
4499 		offset = (ptr - slab_address(slab)) % s->size;
4500 
4501 	/* Adjust for redzone and reject if within the redzone. */
4502 	if (!is_kfence && kmem_cache_debug_flags(s, SLAB_RED_ZONE)) {
4503 		if (offset < s->red_left_pad)
4504 			usercopy_abort("SLUB object in left red zone",
4505 				       s->name, to_user, offset, n);
4506 		offset -= s->red_left_pad;
4507 	}
4508 
4509 	/* Allow address range falling entirely within usercopy region. */
4510 	if (offset >= s->useroffset &&
4511 	    offset - s->useroffset <= s->usersize &&
4512 	    n <= s->useroffset - offset + s->usersize)
4513 		return;
4514 
4515 	usercopy_abort("SLUB object", s->name, to_user, offset, n);
4516 }
4517 #endif /* CONFIG_HARDENED_USERCOPY */
4518 
4519 size_t __ksize(const void *object)
4520 {
4521 	struct folio *folio;
4522 
4523 	if (unlikely(object == ZERO_SIZE_PTR))
4524 		return 0;
4525 
4526 	folio = virt_to_folio(object);
4527 
4528 	if (unlikely(!folio_test_slab(folio)))
4529 		return folio_size(folio);
4530 
4531 	return slab_ksize(folio_slab(folio)->slab_cache);
4532 }
4533 EXPORT_SYMBOL(__ksize);
4534 
4535 void kfree(const void *x)
4536 {
4537 	struct folio *folio;
4538 	struct slab *slab;
4539 	void *object = (void *)x;
4540 
4541 	trace_kfree(_RET_IP_, x);
4542 
4543 	if (unlikely(ZERO_OR_NULL_PTR(x)))
4544 		return;
4545 
4546 	folio = virt_to_folio(x);
4547 	if (unlikely(!folio_test_slab(folio))) {
4548 		free_large_kmalloc(folio, object);
4549 		return;
4550 	}
4551 	slab = folio_slab(folio);
4552 	slab_free(slab->slab_cache, slab, object, NULL, 1, _RET_IP_);
4553 }
4554 EXPORT_SYMBOL(kfree);
4555 
4556 #define SHRINK_PROMOTE_MAX 32
4557 
4558 /*
4559  * kmem_cache_shrink discards empty slabs and promotes the slabs filled
4560  * up most to the head of the partial lists. New allocations will then
4561  * fill those up and thus they can be removed from the partial lists.
4562  *
4563  * The slabs with the least items are placed last. This results in them
4564  * being allocated from last increasing the chance that the last objects
4565  * are freed in them.
4566  */
4567 static int __kmem_cache_do_shrink(struct kmem_cache *s)
4568 {
4569 	int node;
4570 	int i;
4571 	struct kmem_cache_node *n;
4572 	struct slab *slab;
4573 	struct slab *t;
4574 	struct list_head discard;
4575 	struct list_head promote[SHRINK_PROMOTE_MAX];
4576 	unsigned long flags;
4577 	int ret = 0;
4578 
4579 	for_each_kmem_cache_node(s, node, n) {
4580 		INIT_LIST_HEAD(&discard);
4581 		for (i = 0; i < SHRINK_PROMOTE_MAX; i++)
4582 			INIT_LIST_HEAD(promote + i);
4583 
4584 		spin_lock_irqsave(&n->list_lock, flags);
4585 
4586 		/*
4587 		 * Build lists of slabs to discard or promote.
4588 		 *
4589 		 * Note that concurrent frees may occur while we hold the
4590 		 * list_lock. slab->inuse here is the upper limit.
4591 		 */
4592 		list_for_each_entry_safe(slab, t, &n->partial, slab_list) {
4593 			int free = slab->objects - slab->inuse;
4594 
4595 			/* Do not reread slab->inuse */
4596 			barrier();
4597 
4598 			/* We do not keep full slabs on the list */
4599 			BUG_ON(free <= 0);
4600 
4601 			if (free == slab->objects) {
4602 				list_move(&slab->slab_list, &discard);
4603 				n->nr_partial--;
4604 			} else if (free <= SHRINK_PROMOTE_MAX)
4605 				list_move(&slab->slab_list, promote + free - 1);
4606 		}
4607 
4608 		/*
4609 		 * Promote the slabs filled up most to the head of the
4610 		 * partial list.
4611 		 */
4612 		for (i = SHRINK_PROMOTE_MAX - 1; i >= 0; i--)
4613 			list_splice(promote + i, &n->partial);
4614 
4615 		spin_unlock_irqrestore(&n->list_lock, flags);
4616 
4617 		/* Release empty slabs */
4618 		list_for_each_entry_safe(slab, t, &discard, slab_list)
4619 			discard_slab(s, slab);
4620 
4621 		if (slabs_node(s, node))
4622 			ret = 1;
4623 	}
4624 
4625 	return ret;
4626 }
4627 
4628 int __kmem_cache_shrink(struct kmem_cache *s)
4629 {
4630 	flush_all(s);
4631 	return __kmem_cache_do_shrink(s);
4632 }
4633 
4634 static int slab_mem_going_offline_callback(void *arg)
4635 {
4636 	struct kmem_cache *s;
4637 
4638 	mutex_lock(&slab_mutex);
4639 	list_for_each_entry(s, &slab_caches, list) {
4640 		flush_all_cpus_locked(s);
4641 		__kmem_cache_do_shrink(s);
4642 	}
4643 	mutex_unlock(&slab_mutex);
4644 
4645 	return 0;
4646 }
4647 
4648 static void slab_mem_offline_callback(void *arg)
4649 {
4650 	struct memory_notify *marg = arg;
4651 	int offline_node;
4652 
4653 	offline_node = marg->status_change_nid_normal;
4654 
4655 	/*
4656 	 * If the node still has available memory. we need kmem_cache_node
4657 	 * for it yet.
4658 	 */
4659 	if (offline_node < 0)
4660 		return;
4661 
4662 	mutex_lock(&slab_mutex);
4663 	node_clear(offline_node, slab_nodes);
4664 	/*
4665 	 * We no longer free kmem_cache_node structures here, as it would be
4666 	 * racy with all get_node() users, and infeasible to protect them with
4667 	 * slab_mutex.
4668 	 */
4669 	mutex_unlock(&slab_mutex);
4670 }
4671 
4672 static int slab_mem_going_online_callback(void *arg)
4673 {
4674 	struct kmem_cache_node *n;
4675 	struct kmem_cache *s;
4676 	struct memory_notify *marg = arg;
4677 	int nid = marg->status_change_nid_normal;
4678 	int ret = 0;
4679 
4680 	/*
4681 	 * If the node's memory is already available, then kmem_cache_node is
4682 	 * already created. Nothing to do.
4683 	 */
4684 	if (nid < 0)
4685 		return 0;
4686 
4687 	/*
4688 	 * We are bringing a node online. No memory is available yet. We must
4689 	 * allocate a kmem_cache_node structure in order to bring the node
4690 	 * online.
4691 	 */
4692 	mutex_lock(&slab_mutex);
4693 	list_for_each_entry(s, &slab_caches, list) {
4694 		/*
4695 		 * The structure may already exist if the node was previously
4696 		 * onlined and offlined.
4697 		 */
4698 		if (get_node(s, nid))
4699 			continue;
4700 		/*
4701 		 * XXX: kmem_cache_alloc_node will fallback to other nodes
4702 		 *      since memory is not yet available from the node that
4703 		 *      is brought up.
4704 		 */
4705 		n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
4706 		if (!n) {
4707 			ret = -ENOMEM;
4708 			goto out;
4709 		}
4710 		init_kmem_cache_node(n);
4711 		s->node[nid] = n;
4712 	}
4713 	/*
4714 	 * Any cache created after this point will also have kmem_cache_node
4715 	 * initialized for the new node.
4716 	 */
4717 	node_set(nid, slab_nodes);
4718 out:
4719 	mutex_unlock(&slab_mutex);
4720 	return ret;
4721 }
4722 
4723 static int slab_memory_callback(struct notifier_block *self,
4724 				unsigned long action, void *arg)
4725 {
4726 	int ret = 0;
4727 
4728 	switch (action) {
4729 	case MEM_GOING_ONLINE:
4730 		ret = slab_mem_going_online_callback(arg);
4731 		break;
4732 	case MEM_GOING_OFFLINE:
4733 		ret = slab_mem_going_offline_callback(arg);
4734 		break;
4735 	case MEM_OFFLINE:
4736 	case MEM_CANCEL_ONLINE:
4737 		slab_mem_offline_callback(arg);
4738 		break;
4739 	case MEM_ONLINE:
4740 	case MEM_CANCEL_OFFLINE:
4741 		break;
4742 	}
4743 	if (ret)
4744 		ret = notifier_from_errno(ret);
4745 	else
4746 		ret = NOTIFY_OK;
4747 	return ret;
4748 }
4749 
4750 static struct notifier_block slab_memory_callback_nb = {
4751 	.notifier_call = slab_memory_callback,
4752 	.priority = SLAB_CALLBACK_PRI,
4753 };
4754 
4755 /********************************************************************
4756  *			Basic setup of slabs
4757  *******************************************************************/
4758 
4759 /*
4760  * Used for early kmem_cache structures that were allocated using
4761  * the page allocator. Allocate them properly then fix up the pointers
4762  * that may be pointing to the wrong kmem_cache structure.
4763  */
4764 
4765 static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache)
4766 {
4767 	int node;
4768 	struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
4769 	struct kmem_cache_node *n;
4770 
4771 	memcpy(s, static_cache, kmem_cache->object_size);
4772 
4773 	/*
4774 	 * This runs very early, and only the boot processor is supposed to be
4775 	 * up.  Even if it weren't true, IRQs are not up so we couldn't fire
4776 	 * IPIs around.
4777 	 */
4778 	__flush_cpu_slab(s, smp_processor_id());
4779 	for_each_kmem_cache_node(s, node, n) {
4780 		struct slab *p;
4781 
4782 		list_for_each_entry(p, &n->partial, slab_list)
4783 			p->slab_cache = s;
4784 
4785 #ifdef CONFIG_SLUB_DEBUG
4786 		list_for_each_entry(p, &n->full, slab_list)
4787 			p->slab_cache = s;
4788 #endif
4789 	}
4790 	list_add(&s->list, &slab_caches);
4791 	return s;
4792 }
4793 
4794 void __init kmem_cache_init(void)
4795 {
4796 	static __initdata struct kmem_cache boot_kmem_cache,
4797 		boot_kmem_cache_node;
4798 	int node;
4799 
4800 	if (debug_guardpage_minorder())
4801 		slub_max_order = 0;
4802 
4803 	/* Print slub debugging pointers without hashing */
4804 	if (__slub_debug_enabled())
4805 		no_hash_pointers_enable(NULL);
4806 
4807 	kmem_cache_node = &boot_kmem_cache_node;
4808 	kmem_cache = &boot_kmem_cache;
4809 
4810 	/*
4811 	 * Initialize the nodemask for which we will allocate per node
4812 	 * structures. Here we don't need taking slab_mutex yet.
4813 	 */
4814 	for_each_node_state(node, N_NORMAL_MEMORY)
4815 		node_set(node, slab_nodes);
4816 
4817 	create_boot_cache(kmem_cache_node, "kmem_cache_node",
4818 		sizeof(struct kmem_cache_node), SLAB_HWCACHE_ALIGN, 0, 0);
4819 
4820 	register_hotmemory_notifier(&slab_memory_callback_nb);
4821 
4822 	/* Able to allocate the per node structures */
4823 	slab_state = PARTIAL;
4824 
4825 	create_boot_cache(kmem_cache, "kmem_cache",
4826 			offsetof(struct kmem_cache, node) +
4827 				nr_node_ids * sizeof(struct kmem_cache_node *),
4828 		       SLAB_HWCACHE_ALIGN, 0, 0);
4829 
4830 	kmem_cache = bootstrap(&boot_kmem_cache);
4831 	kmem_cache_node = bootstrap(&boot_kmem_cache_node);
4832 
4833 	/* Now we can use the kmem_cache to allocate kmalloc slabs */
4834 	setup_kmalloc_cache_index_table();
4835 	create_kmalloc_caches(0);
4836 
4837 	/* Setup random freelists for each cache */
4838 	init_freelist_randomization();
4839 
4840 	cpuhp_setup_state_nocalls(CPUHP_SLUB_DEAD, "slub:dead", NULL,
4841 				  slub_cpu_dead);
4842 
4843 	pr_info("SLUB: HWalign=%d, Order=%u-%u, MinObjects=%u, CPUs=%u, Nodes=%u\n",
4844 		cache_line_size(),
4845 		slub_min_order, slub_max_order, slub_min_objects,
4846 		nr_cpu_ids, nr_node_ids);
4847 }
4848 
4849 void __init kmem_cache_init_late(void)
4850 {
4851 }
4852 
4853 struct kmem_cache *
4854 __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
4855 		   slab_flags_t flags, void (*ctor)(void *))
4856 {
4857 	struct kmem_cache *s;
4858 
4859 	s = find_mergeable(size, align, flags, name, ctor);
4860 	if (s) {
4861 		s->refcount++;
4862 
4863 		/*
4864 		 * Adjust the object sizes so that we clear
4865 		 * the complete object on kzalloc.
4866 		 */
4867 		s->object_size = max(s->object_size, size);
4868 		s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
4869 
4870 		if (sysfs_slab_alias(s, name)) {
4871 			s->refcount--;
4872 			s = NULL;
4873 		}
4874 	}
4875 
4876 	return s;
4877 }
4878 
4879 int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags)
4880 {
4881 	int err;
4882 
4883 	err = kmem_cache_open(s, flags);
4884 	if (err)
4885 		return err;
4886 
4887 	/* Mutex is not taken during early boot */
4888 	if (slab_state <= UP)
4889 		return 0;
4890 
4891 	err = sysfs_slab_add(s);
4892 	if (err) {
4893 		__kmem_cache_release(s);
4894 		return err;
4895 	}
4896 
4897 	if (s->flags & SLAB_STORE_USER)
4898 		debugfs_slab_add(s);
4899 
4900 	return 0;
4901 }
4902 
4903 void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
4904 {
4905 	struct kmem_cache *s;
4906 	void *ret;
4907 
4908 	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))
4909 		return kmalloc_large(size, gfpflags);
4910 
4911 	s = kmalloc_slab(size, gfpflags);
4912 
4913 	if (unlikely(ZERO_OR_NULL_PTR(s)))
4914 		return s;
4915 
4916 	ret = slab_alloc(s, NULL, gfpflags, caller, size);
4917 
4918 	/* Honor the call site pointer we received. */
4919 	trace_kmalloc(caller, ret, size, s->size, gfpflags);
4920 
4921 	return ret;
4922 }
4923 EXPORT_SYMBOL(__kmalloc_track_caller);
4924 
4925 #ifdef CONFIG_NUMA
4926 void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
4927 					int node, unsigned long caller)
4928 {
4929 	struct kmem_cache *s;
4930 	void *ret;
4931 
4932 	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
4933 		ret = kmalloc_large_node(size, gfpflags, node);
4934 
4935 		trace_kmalloc_node(caller, ret,
4936 				   size, PAGE_SIZE << get_order(size),
4937 				   gfpflags, node);
4938 
4939 		return ret;
4940 	}
4941 
4942 	s = kmalloc_slab(size, gfpflags);
4943 
4944 	if (unlikely(ZERO_OR_NULL_PTR(s)))
4945 		return s;
4946 
4947 	ret = slab_alloc_node(s, NULL, gfpflags, node, caller, size);
4948 
4949 	/* Honor the call site pointer we received. */
4950 	trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
4951 
4952 	return ret;
4953 }
4954 EXPORT_SYMBOL(__kmalloc_node_track_caller);
4955 #endif
4956 
4957 #ifdef CONFIG_SYSFS
4958 static int count_inuse(struct slab *slab)
4959 {
4960 	return slab->inuse;
4961 }
4962 
4963 static int count_total(struct slab *slab)
4964 {
4965 	return slab->objects;
4966 }
4967 #endif
4968 
4969 #ifdef CONFIG_SLUB_DEBUG
4970 static void validate_slab(struct kmem_cache *s, struct slab *slab,
4971 			  unsigned long *obj_map)
4972 {
4973 	void *p;
4974 	void *addr = slab_address(slab);
4975 	unsigned long flags;
4976 
4977 	slab_lock(slab, &flags);
4978 
4979 	if (!check_slab(s, slab) || !on_freelist(s, slab, NULL))
4980 		goto unlock;
4981 
4982 	/* Now we know that a valid freelist exists */
4983 	__fill_map(obj_map, s, slab);
4984 	for_each_object(p, s, addr, slab->objects) {
4985 		u8 val = test_bit(__obj_to_index(s, addr, p), obj_map) ?
4986 			 SLUB_RED_INACTIVE : SLUB_RED_ACTIVE;
4987 
4988 		if (!check_object(s, slab, p, val))
4989 			break;
4990 	}
4991 unlock:
4992 	slab_unlock(slab, &flags);
4993 }
4994 
4995 static int validate_slab_node(struct kmem_cache *s,
4996 		struct kmem_cache_node *n, unsigned long *obj_map)
4997 {
4998 	unsigned long count = 0;
4999 	struct slab *slab;
5000 	unsigned long flags;
5001 
5002 	spin_lock_irqsave(&n->list_lock, flags);
5003 
5004 	list_for_each_entry(slab, &n->partial, slab_list) {
5005 		validate_slab(s, slab, obj_map);
5006 		count++;
5007 	}
5008 	if (count != n->nr_partial) {
5009 		pr_err("SLUB %s: %ld partial slabs counted but counter=%ld\n",
5010 		       s->name, count, n->nr_partial);
5011 		slab_add_kunit_errors();
5012 	}
5013 
5014 	if (!(s->flags & SLAB_STORE_USER))
5015 		goto out;
5016 
5017 	list_for_each_entry(slab, &n->full, slab_list) {
5018 		validate_slab(s, slab, obj_map);
5019 		count++;
5020 	}
5021 	if (count != atomic_long_read(&n->nr_slabs)) {
5022 		pr_err("SLUB: %s %ld slabs counted but counter=%ld\n",
5023 		       s->name, count, atomic_long_read(&n->nr_slabs));
5024 		slab_add_kunit_errors();
5025 	}
5026 
5027 out:
5028 	spin_unlock_irqrestore(&n->list_lock, flags);
5029 	return count;
5030 }
5031 
5032 long validate_slab_cache(struct kmem_cache *s)
5033 {
5034 	int node;
5035 	unsigned long count = 0;
5036 	struct kmem_cache_node *n;
5037 	unsigned long *obj_map;
5038 
5039 	obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
5040 	if (!obj_map)
5041 		return -ENOMEM;
5042 
5043 	flush_all(s);
5044 	for_each_kmem_cache_node(s, node, n)
5045 		count += validate_slab_node(s, n, obj_map);
5046 
5047 	bitmap_free(obj_map);
5048 
5049 	return count;
5050 }
5051 EXPORT_SYMBOL(validate_slab_cache);
5052 
5053 #ifdef CONFIG_DEBUG_FS
5054 /*
5055  * Generate lists of code addresses where slabcache objects are allocated
5056  * and freed.
5057  */
5058 
5059 struct location {
5060 	unsigned long count;
5061 	unsigned long addr;
5062 	long long sum_time;
5063 	long min_time;
5064 	long max_time;
5065 	long min_pid;
5066 	long max_pid;
5067 	DECLARE_BITMAP(cpus, NR_CPUS);
5068 	nodemask_t nodes;
5069 };
5070 
5071 struct loc_track {
5072 	unsigned long max;
5073 	unsigned long count;
5074 	struct location *loc;
5075 	loff_t idx;
5076 };
5077 
5078 static struct dentry *slab_debugfs_root;
5079 
5080 static void free_loc_track(struct loc_track *t)
5081 {
5082 	if (t->max)
5083 		free_pages((unsigned long)t->loc,
5084 			get_order(sizeof(struct location) * t->max));
5085 }
5086 
5087 static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
5088 {
5089 	struct location *l;
5090 	int order;
5091 
5092 	order = get_order(sizeof(struct location) * max);
5093 
5094 	l = (void *)__get_free_pages(flags, order);
5095 	if (!l)
5096 		return 0;
5097 
5098 	if (t->count) {
5099 		memcpy(l, t->loc, sizeof(struct location) * t->count);
5100 		free_loc_track(t);
5101 	}
5102 	t->max = max;
5103 	t->loc = l;
5104 	return 1;
5105 }
5106 
5107 static int add_location(struct loc_track *t, struct kmem_cache *s,
5108 				const struct track *track)
5109 {
5110 	long start, end, pos;
5111 	struct location *l;
5112 	unsigned long caddr;
5113 	unsigned long age = jiffies - track->when;
5114 
5115 	start = -1;
5116 	end = t->count;
5117 
5118 	for ( ; ; ) {
5119 		pos = start + (end - start + 1) / 2;
5120 
5121 		/*
5122 		 * There is nothing at "end". If we end up there
5123 		 * we need to add something to before end.
5124 		 */
5125 		if (pos == end)
5126 			break;
5127 
5128 		caddr = t->loc[pos].addr;
5129 		if (track->addr == caddr) {
5130 
5131 			l = &t->loc[pos];
5132 			l->count++;
5133 			if (track->when) {
5134 				l->sum_time += age;
5135 				if (age < l->min_time)
5136 					l->min_time = age;
5137 				if (age > l->max_time)
5138 					l->max_time = age;
5139 
5140 				if (track->pid < l->min_pid)
5141 					l->min_pid = track->pid;
5142 				if (track->pid > l->max_pid)
5143 					l->max_pid = track->pid;
5144 
5145 				cpumask_set_cpu(track->cpu,
5146 						to_cpumask(l->cpus));
5147 			}
5148 			node_set(page_to_nid(virt_to_page(track)), l->nodes);
5149 			return 1;
5150 		}
5151 
5152 		if (track->addr < caddr)
5153 			end = pos;
5154 		else
5155 			start = pos;
5156 	}
5157 
5158 	/*
5159 	 * Not found. Insert new tracking element.
5160 	 */
5161 	if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
5162 		return 0;
5163 
5164 	l = t->loc + pos;
5165 	if (pos < t->count)
5166 		memmove(l + 1, l,
5167 			(t->count - pos) * sizeof(struct location));
5168 	t->count++;
5169 	l->count = 1;
5170 	l->addr = track->addr;
5171 	l->sum_time = age;
5172 	l->min_time = age;
5173 	l->max_time = age;
5174 	l->min_pid = track->pid;
5175 	l->max_pid = track->pid;
5176 	cpumask_clear(to_cpumask(l->cpus));
5177 	cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
5178 	nodes_clear(l->nodes);
5179 	node_set(page_to_nid(virt_to_page(track)), l->nodes);
5180 	return 1;
5181 }
5182 
5183 static void process_slab(struct loc_track *t, struct kmem_cache *s,
5184 		struct slab *slab, enum track_item alloc,
5185 		unsigned long *obj_map)
5186 {
5187 	void *addr = slab_address(slab);
5188 	void *p;
5189 
5190 	__fill_map(obj_map, s, slab);
5191 
5192 	for_each_object(p, s, addr, slab->objects)
5193 		if (!test_bit(__obj_to_index(s, addr, p), obj_map))
5194 			add_location(t, s, get_track(s, p, alloc));
5195 }
5196 #endif  /* CONFIG_DEBUG_FS   */
5197 #endif	/* CONFIG_SLUB_DEBUG */
5198 
5199 #ifdef CONFIG_SYSFS
5200 enum slab_stat_type {
5201 	SL_ALL,			/* All slabs */
5202 	SL_PARTIAL,		/* Only partially allocated slabs */
5203 	SL_CPU,			/* Only slabs used for cpu caches */
5204 	SL_OBJECTS,		/* Determine allocated objects not slabs */
5205 	SL_TOTAL		/* Determine object capacity not slabs */
5206 };
5207 
5208 #define SO_ALL		(1 << SL_ALL)
5209 #define SO_PARTIAL	(1 << SL_PARTIAL)
5210 #define SO_CPU		(1 << SL_CPU)
5211 #define SO_OBJECTS	(1 << SL_OBJECTS)
5212 #define SO_TOTAL	(1 << SL_TOTAL)
5213 
5214 static ssize_t show_slab_objects(struct kmem_cache *s,
5215 				 char *buf, unsigned long flags)
5216 {
5217 	unsigned long total = 0;
5218 	int node;
5219 	int x;
5220 	unsigned long *nodes;
5221 	int len = 0;
5222 
5223 	nodes = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
5224 	if (!nodes)
5225 		return -ENOMEM;
5226 
5227 	if (flags & SO_CPU) {
5228 		int cpu;
5229 
5230 		for_each_possible_cpu(cpu) {
5231 			struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab,
5232 							       cpu);
5233 			int node;
5234 			struct slab *slab;
5235 
5236 			slab = READ_ONCE(c->slab);
5237 			if (!slab)
5238 				continue;
5239 
5240 			node = slab_nid(slab);
5241 			if (flags & SO_TOTAL)
5242 				x = slab->objects;
5243 			else if (flags & SO_OBJECTS)
5244 				x = slab->inuse;
5245 			else
5246 				x = 1;
5247 
5248 			total += x;
5249 			nodes[node] += x;
5250 
5251 #ifdef CONFIG_SLUB_CPU_PARTIAL
5252 			slab = slub_percpu_partial_read_once(c);
5253 			if (slab) {
5254 				node = slab_nid(slab);
5255 				if (flags & SO_TOTAL)
5256 					WARN_ON_ONCE(1);
5257 				else if (flags & SO_OBJECTS)
5258 					WARN_ON_ONCE(1);
5259 				else
5260 					x = slab->slabs;
5261 				total += x;
5262 				nodes[node] += x;
5263 			}
5264 #endif
5265 		}
5266 	}
5267 
5268 	/*
5269 	 * It is impossible to take "mem_hotplug_lock" here with "kernfs_mutex"
5270 	 * already held which will conflict with an existing lock order:
5271 	 *
5272 	 * mem_hotplug_lock->slab_mutex->kernfs_mutex
5273 	 *
5274 	 * We don't really need mem_hotplug_lock (to hold off
5275 	 * slab_mem_going_offline_callback) here because slab's memory hot
5276 	 * unplug code doesn't destroy the kmem_cache->node[] data.
5277 	 */
5278 
5279 #ifdef CONFIG_SLUB_DEBUG
5280 	if (flags & SO_ALL) {
5281 		struct kmem_cache_node *n;
5282 
5283 		for_each_kmem_cache_node(s, node, n) {
5284 
5285 			if (flags & SO_TOTAL)
5286 				x = atomic_long_read(&n->total_objects);
5287 			else if (flags & SO_OBJECTS)
5288 				x = atomic_long_read(&n->total_objects) -
5289 					count_partial(n, count_free);
5290 			else
5291 				x = atomic_long_read(&n->nr_slabs);
5292 			total += x;
5293 			nodes[node] += x;
5294 		}
5295 
5296 	} else
5297 #endif
5298 	if (flags & SO_PARTIAL) {
5299 		struct kmem_cache_node *n;
5300 
5301 		for_each_kmem_cache_node(s, node, n) {
5302 			if (flags & SO_TOTAL)
5303 				x = count_partial(n, count_total);
5304 			else if (flags & SO_OBJECTS)
5305 				x = count_partial(n, count_inuse);
5306 			else
5307 				x = n->nr_partial;
5308 			total += x;
5309 			nodes[node] += x;
5310 		}
5311 	}
5312 
5313 	len += sysfs_emit_at(buf, len, "%lu", total);
5314 #ifdef CONFIG_NUMA
5315 	for (node = 0; node < nr_node_ids; node++) {
5316 		if (nodes[node])
5317 			len += sysfs_emit_at(buf, len, " N%d=%lu",
5318 					     node, nodes[node]);
5319 	}
5320 #endif
5321 	len += sysfs_emit_at(buf, len, "\n");
5322 	kfree(nodes);
5323 
5324 	return len;
5325 }
5326 
5327 #define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
5328 #define to_slab(n) container_of(n, struct kmem_cache, kobj)
5329 
5330 struct slab_attribute {
5331 	struct attribute attr;
5332 	ssize_t (*show)(struct kmem_cache *s, char *buf);
5333 	ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
5334 };
5335 
5336 #define SLAB_ATTR_RO(_name) \
5337 	static struct slab_attribute _name##_attr = __ATTR_RO_MODE(_name, 0400)
5338 
5339 #define SLAB_ATTR(_name) \
5340 	static struct slab_attribute _name##_attr = __ATTR_RW_MODE(_name, 0600)
5341 
5342 static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
5343 {
5344 	return sysfs_emit(buf, "%u\n", s->size);
5345 }
5346 SLAB_ATTR_RO(slab_size);
5347 
5348 static ssize_t align_show(struct kmem_cache *s, char *buf)
5349 {
5350 	return sysfs_emit(buf, "%u\n", s->align);
5351 }
5352 SLAB_ATTR_RO(align);
5353 
5354 static ssize_t object_size_show(struct kmem_cache *s, char *buf)
5355 {
5356 	return sysfs_emit(buf, "%u\n", s->object_size);
5357 }
5358 SLAB_ATTR_RO(object_size);
5359 
5360 static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
5361 {
5362 	return sysfs_emit(buf, "%u\n", oo_objects(s->oo));
5363 }
5364 SLAB_ATTR_RO(objs_per_slab);
5365 
5366 static ssize_t order_show(struct kmem_cache *s, char *buf)
5367 {
5368 	return sysfs_emit(buf, "%u\n", oo_order(s->oo));
5369 }
5370 SLAB_ATTR_RO(order);
5371 
5372 static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
5373 {
5374 	return sysfs_emit(buf, "%lu\n", s->min_partial);
5375 }
5376 
5377 static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
5378 				 size_t length)
5379 {
5380 	unsigned long min;
5381 	int err;
5382 
5383 	err = kstrtoul(buf, 10, &min);
5384 	if (err)
5385 		return err;
5386 
5387 	s->min_partial = min;
5388 	return length;
5389 }
5390 SLAB_ATTR(min_partial);
5391 
5392 static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
5393 {
5394 	unsigned int nr_partial = 0;
5395 #ifdef CONFIG_SLUB_CPU_PARTIAL
5396 	nr_partial = s->cpu_partial;
5397 #endif
5398 
5399 	return sysfs_emit(buf, "%u\n", nr_partial);
5400 }
5401 
5402 static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
5403 				 size_t length)
5404 {
5405 	unsigned int objects;
5406 	int err;
5407 
5408 	err = kstrtouint(buf, 10, &objects);
5409 	if (err)
5410 		return err;
5411 	if (objects && !kmem_cache_has_cpu_partial(s))
5412 		return -EINVAL;
5413 
5414 	slub_set_cpu_partial(s, objects);
5415 	flush_all(s);
5416 	return length;
5417 }
5418 SLAB_ATTR(cpu_partial);
5419 
5420 static ssize_t ctor_show(struct kmem_cache *s, char *buf)
5421 {
5422 	if (!s->ctor)
5423 		return 0;
5424 	return sysfs_emit(buf, "%pS\n", s->ctor);
5425 }
5426 SLAB_ATTR_RO(ctor);
5427 
5428 static ssize_t aliases_show(struct kmem_cache *s, char *buf)
5429 {
5430 	return sysfs_emit(buf, "%d\n", s->refcount < 0 ? 0 : s->refcount - 1);
5431 }
5432 SLAB_ATTR_RO(aliases);
5433 
5434 static ssize_t partial_show(struct kmem_cache *s, char *buf)
5435 {
5436 	return show_slab_objects(s, buf, SO_PARTIAL);
5437 }
5438 SLAB_ATTR_RO(partial);
5439 
5440 static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
5441 {
5442 	return show_slab_objects(s, buf, SO_CPU);
5443 }
5444 SLAB_ATTR_RO(cpu_slabs);
5445 
5446 static ssize_t objects_show(struct kmem_cache *s, char *buf)
5447 {
5448 	return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
5449 }
5450 SLAB_ATTR_RO(objects);
5451 
5452 static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
5453 {
5454 	return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
5455 }
5456 SLAB_ATTR_RO(objects_partial);
5457 
5458 static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
5459 {
5460 	int objects = 0;
5461 	int slabs = 0;
5462 	int cpu __maybe_unused;
5463 	int len = 0;
5464 
5465 #ifdef CONFIG_SLUB_CPU_PARTIAL
5466 	for_each_online_cpu(cpu) {
5467 		struct slab *slab;
5468 
5469 		slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu));
5470 
5471 		if (slab)
5472 			slabs += slab->slabs;
5473 	}
5474 #endif
5475 
5476 	/* Approximate half-full slabs, see slub_set_cpu_partial() */
5477 	objects = (slabs * oo_objects(s->oo)) / 2;
5478 	len += sysfs_emit_at(buf, len, "%d(%d)", objects, slabs);
5479 
5480 #if defined(CONFIG_SLUB_CPU_PARTIAL) && defined(CONFIG_SMP)
5481 	for_each_online_cpu(cpu) {
5482 		struct slab *slab;
5483 
5484 		slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu));
5485 		if (slab) {
5486 			slabs = READ_ONCE(slab->slabs);
5487 			objects = (slabs * oo_objects(s->oo)) / 2;
5488 			len += sysfs_emit_at(buf, len, " C%d=%d(%d)",
5489 					     cpu, objects, slabs);
5490 		}
5491 	}
5492 #endif
5493 	len += sysfs_emit_at(buf, len, "\n");
5494 
5495 	return len;
5496 }
5497 SLAB_ATTR_RO(slabs_cpu_partial);
5498 
5499 static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
5500 {
5501 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
5502 }
5503 SLAB_ATTR_RO(reclaim_account);
5504 
5505 static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
5506 {
5507 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
5508 }
5509 SLAB_ATTR_RO(hwcache_align);
5510 
5511 #ifdef CONFIG_ZONE_DMA
5512 static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
5513 {
5514 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
5515 }
5516 SLAB_ATTR_RO(cache_dma);
5517 #endif
5518 
5519 static ssize_t usersize_show(struct kmem_cache *s, char *buf)
5520 {
5521 	return sysfs_emit(buf, "%u\n", s->usersize);
5522 }
5523 SLAB_ATTR_RO(usersize);
5524 
5525 static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
5526 {
5527 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TYPESAFE_BY_RCU));
5528 }
5529 SLAB_ATTR_RO(destroy_by_rcu);
5530 
5531 #ifdef CONFIG_SLUB_DEBUG
5532 static ssize_t slabs_show(struct kmem_cache *s, char *buf)
5533 {
5534 	return show_slab_objects(s, buf, SO_ALL);
5535 }
5536 SLAB_ATTR_RO(slabs);
5537 
5538 static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
5539 {
5540 	return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
5541 }
5542 SLAB_ATTR_RO(total_objects);
5543 
5544 static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
5545 {
5546 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CONSISTENCY_CHECKS));
5547 }
5548 SLAB_ATTR_RO(sanity_checks);
5549 
5550 static ssize_t trace_show(struct kmem_cache *s, char *buf)
5551 {
5552 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TRACE));
5553 }
5554 SLAB_ATTR_RO(trace);
5555 
5556 static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
5557 {
5558 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
5559 }
5560 
5561 SLAB_ATTR_RO(red_zone);
5562 
5563 static ssize_t poison_show(struct kmem_cache *s, char *buf)
5564 {
5565 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_POISON));
5566 }
5567 
5568 SLAB_ATTR_RO(poison);
5569 
5570 static ssize_t store_user_show(struct kmem_cache *s, char *buf)
5571 {
5572 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
5573 }
5574 
5575 SLAB_ATTR_RO(store_user);
5576 
5577 static ssize_t validate_show(struct kmem_cache *s, char *buf)
5578 {
5579 	return 0;
5580 }
5581 
5582 static ssize_t validate_store(struct kmem_cache *s,
5583 			const char *buf, size_t length)
5584 {
5585 	int ret = -EINVAL;
5586 
5587 	if (buf[0] == '1') {
5588 		ret = validate_slab_cache(s);
5589 		if (ret >= 0)
5590 			ret = length;
5591 	}
5592 	return ret;
5593 }
5594 SLAB_ATTR(validate);
5595 
5596 #endif /* CONFIG_SLUB_DEBUG */
5597 
5598 #ifdef CONFIG_FAILSLAB
5599 static ssize_t failslab_show(struct kmem_cache *s, char *buf)
5600 {
5601 	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
5602 }
5603 SLAB_ATTR_RO(failslab);
5604 #endif
5605 
5606 static ssize_t shrink_show(struct kmem_cache *s, char *buf)
5607 {
5608 	return 0;
5609 }
5610 
5611 static ssize_t shrink_store(struct kmem_cache *s,
5612 			const char *buf, size_t length)
5613 {
5614 	if (buf[0] == '1')
5615 		kmem_cache_shrink(s);
5616 	else
5617 		return -EINVAL;
5618 	return length;
5619 }
5620 SLAB_ATTR(shrink);
5621 
5622 #ifdef CONFIG_NUMA
5623 static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
5624 {
5625 	return sysfs_emit(buf, "%u\n", s->remote_node_defrag_ratio / 10);
5626 }
5627 
5628 static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
5629 				const char *buf, size_t length)
5630 {
5631 	unsigned int ratio;
5632 	int err;
5633 
5634 	err = kstrtouint(buf, 10, &ratio);
5635 	if (err)
5636 		return err;
5637 	if (ratio > 100)
5638 		return -ERANGE;
5639 
5640 	s->remote_node_defrag_ratio = ratio * 10;
5641 
5642 	return length;
5643 }
5644 SLAB_ATTR(remote_node_defrag_ratio);
5645 #endif
5646 
5647 #ifdef CONFIG_SLUB_STATS
5648 static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
5649 {
5650 	unsigned long sum  = 0;
5651 	int cpu;
5652 	int len = 0;
5653 	int *data = kmalloc_array(nr_cpu_ids, sizeof(int), GFP_KERNEL);
5654 
5655 	if (!data)
5656 		return -ENOMEM;
5657 
5658 	for_each_online_cpu(cpu) {
5659 		unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
5660 
5661 		data[cpu] = x;
5662 		sum += x;
5663 	}
5664 
5665 	len += sysfs_emit_at(buf, len, "%lu", sum);
5666 
5667 #ifdef CONFIG_SMP
5668 	for_each_online_cpu(cpu) {
5669 		if (data[cpu])
5670 			len += sysfs_emit_at(buf, len, " C%d=%u",
5671 					     cpu, data[cpu]);
5672 	}
5673 #endif
5674 	kfree(data);
5675 	len += sysfs_emit_at(buf, len, "\n");
5676 
5677 	return len;
5678 }
5679 
5680 static void clear_stat(struct kmem_cache *s, enum stat_item si)
5681 {
5682 	int cpu;
5683 
5684 	for_each_online_cpu(cpu)
5685 		per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
5686 }
5687 
5688 #define STAT_ATTR(si, text) 					\
5689 static ssize_t text##_show(struct kmem_cache *s, char *buf)	\
5690 {								\
5691 	return show_stat(s, buf, si);				\
5692 }								\
5693 static ssize_t text##_store(struct kmem_cache *s,		\
5694 				const char *buf, size_t length)	\
5695 {								\
5696 	if (buf[0] != '0')					\
5697 		return -EINVAL;					\
5698 	clear_stat(s, si);					\
5699 	return length;						\
5700 }								\
5701 SLAB_ATTR(text);						\
5702 
5703 STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
5704 STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
5705 STAT_ATTR(FREE_FASTPATH, free_fastpath);
5706 STAT_ATTR(FREE_SLOWPATH, free_slowpath);
5707 STAT_ATTR(FREE_FROZEN, free_frozen);
5708 STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
5709 STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
5710 STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
5711 STAT_ATTR(ALLOC_SLAB, alloc_slab);
5712 STAT_ATTR(ALLOC_REFILL, alloc_refill);
5713 STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch);
5714 STAT_ATTR(FREE_SLAB, free_slab);
5715 STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
5716 STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
5717 STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
5718 STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
5719 STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
5720 STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
5721 STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass);
5722 STAT_ATTR(ORDER_FALLBACK, order_fallback);
5723 STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
5724 STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
5725 STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc);
5726 STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);
5727 STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node);
5728 STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain);
5729 #endif	/* CONFIG_SLUB_STATS */
5730 
5731 static struct attribute *slab_attrs[] = {
5732 	&slab_size_attr.attr,
5733 	&object_size_attr.attr,
5734 	&objs_per_slab_attr.attr,
5735 	&order_attr.attr,
5736 	&min_partial_attr.attr,
5737 	&cpu_partial_attr.attr,
5738 	&objects_attr.attr,
5739 	&objects_partial_attr.attr,
5740 	&partial_attr.attr,
5741 	&cpu_slabs_attr.attr,
5742 	&ctor_attr.attr,
5743 	&aliases_attr.attr,
5744 	&align_attr.attr,
5745 	&hwcache_align_attr.attr,
5746 	&reclaim_account_attr.attr,
5747 	&destroy_by_rcu_attr.attr,
5748 	&shrink_attr.attr,
5749 	&slabs_cpu_partial_attr.attr,
5750 #ifdef CONFIG_SLUB_DEBUG
5751 	&total_objects_attr.attr,
5752 	&slabs_attr.attr,
5753 	&sanity_checks_attr.attr,
5754 	&trace_attr.attr,
5755 	&red_zone_attr.attr,
5756 	&poison_attr.attr,
5757 	&store_user_attr.attr,
5758 	&validate_attr.attr,
5759 #endif
5760 #ifdef CONFIG_ZONE_DMA
5761 	&cache_dma_attr.attr,
5762 #endif
5763 #ifdef CONFIG_NUMA
5764 	&remote_node_defrag_ratio_attr.attr,
5765 #endif
5766 #ifdef CONFIG_SLUB_STATS
5767 	&alloc_fastpath_attr.attr,
5768 	&alloc_slowpath_attr.attr,
5769 	&free_fastpath_attr.attr,
5770 	&free_slowpath_attr.attr,
5771 	&free_frozen_attr.attr,
5772 	&free_add_partial_attr.attr,
5773 	&free_remove_partial_attr.attr,
5774 	&alloc_from_partial_attr.attr,
5775 	&alloc_slab_attr.attr,
5776 	&alloc_refill_attr.attr,
5777 	&alloc_node_mismatch_attr.attr,
5778 	&free_slab_attr.attr,
5779 	&cpuslab_flush_attr.attr,
5780 	&deactivate_full_attr.attr,
5781 	&deactivate_empty_attr.attr,
5782 	&deactivate_to_head_attr.attr,
5783 	&deactivate_to_tail_attr.attr,
5784 	&deactivate_remote_frees_attr.attr,
5785 	&deactivate_bypass_attr.attr,
5786 	&order_fallback_attr.attr,
5787 	&cmpxchg_double_fail_attr.attr,
5788 	&cmpxchg_double_cpu_fail_attr.attr,
5789 	&cpu_partial_alloc_attr.attr,
5790 	&cpu_partial_free_attr.attr,
5791 	&cpu_partial_node_attr.attr,
5792 	&cpu_partial_drain_attr.attr,
5793 #endif
5794 #ifdef CONFIG_FAILSLAB
5795 	&failslab_attr.attr,
5796 #endif
5797 	&usersize_attr.attr,
5798 
5799 	NULL
5800 };
5801 
5802 static const struct attribute_group slab_attr_group = {
5803 	.attrs = slab_attrs,
5804 };
5805 
5806 static ssize_t slab_attr_show(struct kobject *kobj,
5807 				struct attribute *attr,
5808 				char *buf)
5809 {
5810 	struct slab_attribute *attribute;
5811 	struct kmem_cache *s;
5812 	int err;
5813 
5814 	attribute = to_slab_attr(attr);
5815 	s = to_slab(kobj);
5816 
5817 	if (!attribute->show)
5818 		return -EIO;
5819 
5820 	err = attribute->show(s, buf);
5821 
5822 	return err;
5823 }
5824 
5825 static ssize_t slab_attr_store(struct kobject *kobj,
5826 				struct attribute *attr,
5827 				const char *buf, size_t len)
5828 {
5829 	struct slab_attribute *attribute;
5830 	struct kmem_cache *s;
5831 	int err;
5832 
5833 	attribute = to_slab_attr(attr);
5834 	s = to_slab(kobj);
5835 
5836 	if (!attribute->store)
5837 		return -EIO;
5838 
5839 	err = attribute->store(s, buf, len);
5840 	return err;
5841 }
5842 
5843 static void kmem_cache_release(struct kobject *k)
5844 {
5845 	slab_kmem_cache_release(to_slab(k));
5846 }
5847 
5848 static const struct sysfs_ops slab_sysfs_ops = {
5849 	.show = slab_attr_show,
5850 	.store = slab_attr_store,
5851 };
5852 
5853 static struct kobj_type slab_ktype = {
5854 	.sysfs_ops = &slab_sysfs_ops,
5855 	.release = kmem_cache_release,
5856 };
5857 
5858 static struct kset *slab_kset;
5859 
5860 static inline struct kset *cache_kset(struct kmem_cache *s)
5861 {
5862 	return slab_kset;
5863 }
5864 
5865 #define ID_STR_LENGTH 64
5866 
5867 /* Create a unique string id for a slab cache:
5868  *
5869  * Format	:[flags-]size
5870  */
5871 static char *create_unique_id(struct kmem_cache *s)
5872 {
5873 	char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
5874 	char *p = name;
5875 
5876 	BUG_ON(!name);
5877 
5878 	*p++ = ':';
5879 	/*
5880 	 * First flags affecting slabcache operations. We will only
5881 	 * get here for aliasable slabs so we do not need to support
5882 	 * too many flags. The flags here must cover all flags that
5883 	 * are matched during merging to guarantee that the id is
5884 	 * unique.
5885 	 */
5886 	if (s->flags & SLAB_CACHE_DMA)
5887 		*p++ = 'd';
5888 	if (s->flags & SLAB_CACHE_DMA32)
5889 		*p++ = 'D';
5890 	if (s->flags & SLAB_RECLAIM_ACCOUNT)
5891 		*p++ = 'a';
5892 	if (s->flags & SLAB_CONSISTENCY_CHECKS)
5893 		*p++ = 'F';
5894 	if (s->flags & SLAB_ACCOUNT)
5895 		*p++ = 'A';
5896 	if (p != name + 1)
5897 		*p++ = '-';
5898 	p += sprintf(p, "%07u", s->size);
5899 
5900 	BUG_ON(p > name + ID_STR_LENGTH - 1);
5901 	return name;
5902 }
5903 
5904 static int sysfs_slab_add(struct kmem_cache *s)
5905 {
5906 	int err;
5907 	const char *name;
5908 	struct kset *kset = cache_kset(s);
5909 	int unmergeable = slab_unmergeable(s);
5910 
5911 	if (!kset) {
5912 		kobject_init(&s->kobj, &slab_ktype);
5913 		return 0;
5914 	}
5915 
5916 	if (!unmergeable && disable_higher_order_debug &&
5917 			(slub_debug & DEBUG_METADATA_FLAGS))
5918 		unmergeable = 1;
5919 
5920 	if (unmergeable) {
5921 		/*
5922 		 * Slabcache can never be merged so we can use the name proper.
5923 		 * This is typically the case for debug situations. In that
5924 		 * case we can catch duplicate names easily.
5925 		 */
5926 		sysfs_remove_link(&slab_kset->kobj, s->name);
5927 		name = s->name;
5928 	} else {
5929 		/*
5930 		 * Create a unique name for the slab as a target
5931 		 * for the symlinks.
5932 		 */
5933 		name = create_unique_id(s);
5934 	}
5935 
5936 	s->kobj.kset = kset;
5937 	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
5938 	if (err)
5939 		goto out;
5940 
5941 	err = sysfs_create_group(&s->kobj, &slab_attr_group);
5942 	if (err)
5943 		goto out_del_kobj;
5944 
5945 	if (!unmergeable) {
5946 		/* Setup first alias */
5947 		sysfs_slab_alias(s, s->name);
5948 	}
5949 out:
5950 	if (!unmergeable)
5951 		kfree(name);
5952 	return err;
5953 out_del_kobj:
5954 	kobject_del(&s->kobj);
5955 	goto out;
5956 }
5957 
5958 void sysfs_slab_unlink(struct kmem_cache *s)
5959 {
5960 	if (slab_state >= FULL)
5961 		kobject_del(&s->kobj);
5962 }
5963 
5964 void sysfs_slab_release(struct kmem_cache *s)
5965 {
5966 	if (slab_state >= FULL)
5967 		kobject_put(&s->kobj);
5968 }
5969 
5970 /*
5971  * Need to buffer aliases during bootup until sysfs becomes
5972  * available lest we lose that information.
5973  */
5974 struct saved_alias {
5975 	struct kmem_cache *s;
5976 	const char *name;
5977 	struct saved_alias *next;
5978 };
5979 
5980 static struct saved_alias *alias_list;
5981 
5982 static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
5983 {
5984 	struct saved_alias *al;
5985 
5986 	if (slab_state == FULL) {
5987 		/*
5988 		 * If we have a leftover link then remove it.
5989 		 */
5990 		sysfs_remove_link(&slab_kset->kobj, name);
5991 		return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
5992 	}
5993 
5994 	al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
5995 	if (!al)
5996 		return -ENOMEM;
5997 
5998 	al->s = s;
5999 	al->name = name;
6000 	al->next = alias_list;
6001 	alias_list = al;
6002 	return 0;
6003 }
6004 
6005 static int __init slab_sysfs_init(void)
6006 {
6007 	struct kmem_cache *s;
6008 	int err;
6009 
6010 	mutex_lock(&slab_mutex);
6011 
6012 	slab_kset = kset_create_and_add("slab", NULL, kernel_kobj);
6013 	if (!slab_kset) {
6014 		mutex_unlock(&slab_mutex);
6015 		pr_err("Cannot register slab subsystem.\n");
6016 		return -ENOSYS;
6017 	}
6018 
6019 	slab_state = FULL;
6020 
6021 	list_for_each_entry(s, &slab_caches, list) {
6022 		err = sysfs_slab_add(s);
6023 		if (err)
6024 			pr_err("SLUB: Unable to add boot slab %s to sysfs\n",
6025 			       s->name);
6026 	}
6027 
6028 	while (alias_list) {
6029 		struct saved_alias *al = alias_list;
6030 
6031 		alias_list = alias_list->next;
6032 		err = sysfs_slab_alias(al->s, al->name);
6033 		if (err)
6034 			pr_err("SLUB: Unable to add boot slab alias %s to sysfs\n",
6035 			       al->name);
6036 		kfree(al);
6037 	}
6038 
6039 	mutex_unlock(&slab_mutex);
6040 	return 0;
6041 }
6042 
6043 __initcall(slab_sysfs_init);
6044 #endif /* CONFIG_SYSFS */
6045 
6046 #if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
6047 static int slab_debugfs_show(struct seq_file *seq, void *v)
6048 {
6049 	struct loc_track *t = seq->private;
6050 	struct location *l;
6051 	unsigned long idx;
6052 
6053 	idx = (unsigned long) t->idx;
6054 	if (idx < t->count) {
6055 		l = &t->loc[idx];
6056 
6057 		seq_printf(seq, "%7ld ", l->count);
6058 
6059 		if (l->addr)
6060 			seq_printf(seq, "%pS", (void *)l->addr);
6061 		else
6062 			seq_puts(seq, "<not-available>");
6063 
6064 		if (l->sum_time != l->min_time) {
6065 			seq_printf(seq, " age=%ld/%llu/%ld",
6066 				l->min_time, div_u64(l->sum_time, l->count),
6067 				l->max_time);
6068 		} else
6069 			seq_printf(seq, " age=%ld", l->min_time);
6070 
6071 		if (l->min_pid != l->max_pid)
6072 			seq_printf(seq, " pid=%ld-%ld", l->min_pid, l->max_pid);
6073 		else
6074 			seq_printf(seq, " pid=%ld",
6075 				l->min_pid);
6076 
6077 		if (num_online_cpus() > 1 && !cpumask_empty(to_cpumask(l->cpus)))
6078 			seq_printf(seq, " cpus=%*pbl",
6079 				 cpumask_pr_args(to_cpumask(l->cpus)));
6080 
6081 		if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
6082 			seq_printf(seq, " nodes=%*pbl",
6083 				 nodemask_pr_args(&l->nodes));
6084 
6085 		seq_puts(seq, "\n");
6086 	}
6087 
6088 	if (!idx && !t->count)
6089 		seq_puts(seq, "No data\n");
6090 
6091 	return 0;
6092 }
6093 
6094 static void slab_debugfs_stop(struct seq_file *seq, void *v)
6095 {
6096 }
6097 
6098 static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
6099 {
6100 	struct loc_track *t = seq->private;
6101 
6102 	t->idx = ++(*ppos);
6103 	if (*ppos <= t->count)
6104 		return ppos;
6105 
6106 	return NULL;
6107 }
6108 
6109 static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
6110 {
6111 	struct loc_track *t = seq->private;
6112 
6113 	t->idx = *ppos;
6114 	return ppos;
6115 }
6116 
6117 static const struct seq_operations slab_debugfs_sops = {
6118 	.start  = slab_debugfs_start,
6119 	.next   = slab_debugfs_next,
6120 	.stop   = slab_debugfs_stop,
6121 	.show   = slab_debugfs_show,
6122 };
6123 
6124 static int slab_debug_trace_open(struct inode *inode, struct file *filep)
6125 {
6126 
6127 	struct kmem_cache_node *n;
6128 	enum track_item alloc;
6129 	int node;
6130 	struct loc_track *t = __seq_open_private(filep, &slab_debugfs_sops,
6131 						sizeof(struct loc_track));
6132 	struct kmem_cache *s = file_inode(filep)->i_private;
6133 	unsigned long *obj_map;
6134 
6135 	if (!t)
6136 		return -ENOMEM;
6137 
6138 	obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
6139 	if (!obj_map) {
6140 		seq_release_private(inode, filep);
6141 		return -ENOMEM;
6142 	}
6143 
6144 	if (strcmp(filep->f_path.dentry->d_name.name, "alloc_traces") == 0)
6145 		alloc = TRACK_ALLOC;
6146 	else
6147 		alloc = TRACK_FREE;
6148 
6149 	if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL)) {
6150 		bitmap_free(obj_map);
6151 		seq_release_private(inode, filep);
6152 		return -ENOMEM;
6153 	}
6154 
6155 	for_each_kmem_cache_node(s, node, n) {
6156 		unsigned long flags;
6157 		struct slab *slab;
6158 
6159 		if (!atomic_long_read(&n->nr_slabs))
6160 			continue;
6161 
6162 		spin_lock_irqsave(&n->list_lock, flags);
6163 		list_for_each_entry(slab, &n->partial, slab_list)
6164 			process_slab(t, s, slab, alloc, obj_map);
6165 		list_for_each_entry(slab, &n->full, slab_list)
6166 			process_slab(t, s, slab, alloc, obj_map);
6167 		spin_unlock_irqrestore(&n->list_lock, flags);
6168 	}
6169 
6170 	bitmap_free(obj_map);
6171 	return 0;
6172 }
6173 
6174 static int slab_debug_trace_release(struct inode *inode, struct file *file)
6175 {
6176 	struct seq_file *seq = file->private_data;
6177 	struct loc_track *t = seq->private;
6178 
6179 	free_loc_track(t);
6180 	return seq_release_private(inode, file);
6181 }
6182 
6183 static const struct file_operations slab_debugfs_fops = {
6184 	.open    = slab_debug_trace_open,
6185 	.read    = seq_read,
6186 	.llseek  = seq_lseek,
6187 	.release = slab_debug_trace_release,
6188 };
6189 
6190 static void debugfs_slab_add(struct kmem_cache *s)
6191 {
6192 	struct dentry *slab_cache_dir;
6193 
6194 	if (unlikely(!slab_debugfs_root))
6195 		return;
6196 
6197 	slab_cache_dir = debugfs_create_dir(s->name, slab_debugfs_root);
6198 
6199 	debugfs_create_file("alloc_traces", 0400,
6200 		slab_cache_dir, s, &slab_debugfs_fops);
6201 
6202 	debugfs_create_file("free_traces", 0400,
6203 		slab_cache_dir, s, &slab_debugfs_fops);
6204 }
6205 
6206 void debugfs_slab_release(struct kmem_cache *s)
6207 {
6208 	debugfs_remove_recursive(debugfs_lookup(s->name, slab_debugfs_root));
6209 }
6210 
6211 static int __init slab_debugfs_init(void)
6212 {
6213 	struct kmem_cache *s;
6214 
6215 	slab_debugfs_root = debugfs_create_dir("slab", NULL);
6216 
6217 	list_for_each_entry(s, &slab_caches, list)
6218 		if (s->flags & SLAB_STORE_USER)
6219 			debugfs_slab_add(s);
6220 
6221 	return 0;
6222 
6223 }
6224 __initcall(slab_debugfs_init);
6225 #endif
6226 /*
6227  * The /proc/slabinfo ABI
6228  */
6229 #ifdef CONFIG_SLUB_DEBUG
6230 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
6231 {
6232 	unsigned long nr_slabs = 0;
6233 	unsigned long nr_objs = 0;
6234 	unsigned long nr_free = 0;
6235 	int node;
6236 	struct kmem_cache_node *n;
6237 
6238 	for_each_kmem_cache_node(s, node, n) {
6239 		nr_slabs += node_nr_slabs(n);
6240 		nr_objs += node_nr_objs(n);
6241 		nr_free += count_partial(n, count_free);
6242 	}
6243 
6244 	sinfo->active_objs = nr_objs - nr_free;
6245 	sinfo->num_objs = nr_objs;
6246 	sinfo->active_slabs = nr_slabs;
6247 	sinfo->num_slabs = nr_slabs;
6248 	sinfo->objects_per_slab = oo_objects(s->oo);
6249 	sinfo->cache_order = oo_order(s->oo);
6250 }
6251 
6252 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s)
6253 {
6254 }
6255 
6256 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
6257 		       size_t count, loff_t *ppos)
6258 {
6259 	return -EIO;
6260 }
6261 #endif /* CONFIG_SLUB_DEBUG */
6262