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> /* mm_account_reclaimed_pages() */
  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/kmsan.h>
  26#include <linux/cpu.h>
  27#include <linux/cpuset.h>
  28#include <linux/mempolicy.h>
  29#include <linux/ctype.h>
  30#include <linux/stackdepot.h>
  31#include <linux/debugobjects.h>
  32#include <linux/kallsyms.h>
  33#include <linux/kfence.h>
  34#include <linux/memory.h>
  35#include <linux/math64.h>
  36#include <linux/fault-inject.h>
  37#include <linux/kmemleak.h>
  38#include <linux/stacktrace.h>
  39#include <linux/prefetch.h>
  40#include <linux/memcontrol.h>
  41#include <linux/random.h>
  42#include <kunit/test.h>
  43#include <kunit/test-bug.h>
  44#include <linux/sort.h>
  45
  46#include <linux/debugfs.h>
  47#include <trace/events/kmem.h>
  48
  49#include "internal.h"
  50
  51/*
  52 * Lock order:
  53 *   1. slab_mutex (Global Mutex)
  54 *   2. node->list_lock (Spinlock)
  55 *   3. kmem_cache->cpu_slab->lock (Local lock)
  56 *   4. slab_lock(slab) (Only on some arches)
  57 *   5. object_map_lock (Only for debugging)
  58 *
  59 *   slab_mutex
  60 *
  61 *   The role of the slab_mutex is to protect the list of all the slabs
  62 *   and to synchronize major metadata changes to slab cache structures.
  63 *   Also synchronizes memory hotplug callbacks.
  64 *
  65 *   slab_lock
  66 *
  67 *   The slab_lock is a wrapper around the page lock, thus it is a bit
  68 *   spinlock.
  69 *
  70 *   The slab_lock is only used on arches that do not have the ability
  71 *   to do a cmpxchg_double. It only protects:
  72 *
  73 *	A. slab->freelist	-> List of free objects in a slab
  74 *	B. slab->inuse		-> Number of objects in use
  75 *	C. slab->objects	-> Number of objects in slab
  76 *	D. slab->frozen		-> frozen state
  77 *
  78 *   Frozen slabs
  79 *
  80 *   If a slab is frozen then it is exempt from list management. It is
  81 *   the cpu slab which is actively allocated from by the processor that
  82 *   froze it and it is not on any list. The processor that froze the
  83 *   slab is the one who can perform list operations on the slab. Other
  84 *   processors may put objects onto the freelist but the processor that
  85 *   froze the slab is the only one that can retrieve the objects from the
  86 *   slab's freelist.
  87 *
  88 *   CPU partial slabs
  89 *
  90 *   The partially empty slabs cached on the CPU partial list are used
  91 *   for performance reasons, which speeds up the allocation process.
  92 *   These slabs are not frozen, but are also exempt from list management,
  93 *   by clearing the PG_workingset flag when moving out of the node
  94 *   partial list. Please see __slab_free() for more details.
  95 *
  96 *   To sum up, the current scheme is:
  97 *   - node partial slab: PG_Workingset && !frozen
  98 *   - cpu partial slab: !PG_Workingset && !frozen
  99 *   - cpu slab: !PG_Workingset && frozen
 100 *   - full slab: !PG_Workingset && !frozen
 101 *
 102 *   list_lock
 103 *
 104 *   The list_lock protects the partial and full list on each node and
 105 *   the partial slab counter. If taken then no new slabs may be added or
 106 *   removed from the lists nor make the number of partial slabs be modified.
 107 *   (Note that the total number of slabs is an atomic value that may be
 108 *   modified without taking the list lock).
 109 *
 110 *   The list_lock is a centralized lock and thus we avoid taking it as
 111 *   much as possible. As long as SLUB does not have to handle partial
 112 *   slabs, operations can continue without any centralized lock. F.e.
 113 *   allocating a long series of objects that fill up slabs does not require
 114 *   the list lock.
 115 *
 116 *   For debug caches, all allocations are forced to go through a list_lock
 117 *   protected region to serialize against concurrent validation.
 118 *
 119 *   cpu_slab->lock local lock
 120 *
 121 *   This locks protect slowpath manipulation of all kmem_cache_cpu fields
 122 *   except the stat counters. This is a percpu structure manipulated only by
 123 *   the local cpu, so the lock protects against being preempted or interrupted
 124 *   by an irq. Fast path operations rely on lockless operations instead.
 125 *
 126 *   On PREEMPT_RT, the local lock neither disables interrupts nor preemption
 127 *   which means the lockless fastpath cannot be used as it might interfere with
 128 *   an in-progress slow path operations. In this case the local lock is always
 129 *   taken but it still utilizes the freelist for the common operations.
 130 *
 131 *   lockless fastpaths
 132 *
 133 *   The fast path allocation (slab_alloc_node()) and freeing (do_slab_free())
 134 *   are fully lockless when satisfied from the percpu slab (and when
 135 *   cmpxchg_double is possible to use, otherwise slab_lock is taken).
 136 *   They also don't disable preemption or migration or irqs. They rely on
 137 *   the transaction id (tid) field to detect being preempted or moved to
 138 *   another cpu.
 139 *
 140 *   irq, preemption, migration considerations
 141 *
 142 *   Interrupts are disabled as part of list_lock or local_lock operations, or
 143 *   around the slab_lock operation, in order to make the slab allocator safe
 144 *   to use in the context of an irq.
 145 *
 146 *   In addition, preemption (or migration on PREEMPT_RT) is disabled in the
 147 *   allocation slowpath, bulk allocation, and put_cpu_partial(), so that the
 148 *   local cpu doesn't change in the process and e.g. the kmem_cache_cpu pointer
 149 *   doesn't have to be revalidated in each section protected by the local lock.
 150 *
 151 * SLUB assigns one slab for allocation to each processor.
 152 * Allocations only occur from these slabs called cpu slabs.
 153 *
 154 * Slabs with free elements are kept on a partial list and during regular
 155 * operations no list for full slabs is used. If an object in a full slab is
 156 * freed then the slab will show up again on the partial lists.
 157 * We track full slabs for debugging purposes though because otherwise we
 158 * cannot scan all objects.
 159 *
 160 * Slabs are freed when they become empty. Teardown and setup is
 161 * minimal so we rely on the page allocators per cpu caches for
 162 * fast frees and allocs.
 163 *
 164 * slab->frozen		The slab is frozen and exempt from list processing.
 
 
 165 * 			This means that the slab is dedicated to a purpose
 166 * 			such as satisfying allocations for a specific
 167 * 			processor. Objects may be freed in the slab while
 168 * 			it is frozen but slab_free will then skip the usual
 169 * 			list operations. It is up to the processor holding
 170 * 			the slab to integrate the slab into the slab lists
 171 * 			when the slab is no longer needed.
 172 *
 173 * 			One use of this flag is to mark slabs that are
 174 * 			used for allocations. Then such a slab becomes a cpu
 175 * 			slab. The cpu slab may be equipped with an additional
 176 * 			freelist that allows lockless access to
 177 * 			free objects in addition to the regular freelist
 178 * 			that requires the slab lock.
 179 *
 180 * SLAB_DEBUG_FLAGS	Slab requires special handling due to debug
 181 * 			options set. This moves	slab handling out of
 182 * 			the fast path and disables lockless freelists.
 183 */
 184
 185/*
 186 * We could simply use migrate_disable()/enable() but as long as it's a
 187 * function call even on !PREEMPT_RT, use inline preempt_disable() there.
 188 */
 189#ifndef CONFIG_PREEMPT_RT
 190#define slub_get_cpu_ptr(var)		get_cpu_ptr(var)
 191#define slub_put_cpu_ptr(var)		put_cpu_ptr(var)
 192#define USE_LOCKLESS_FAST_PATH()	(true)
 193#else
 194#define slub_get_cpu_ptr(var)		\
 195({					\
 196	migrate_disable();		\
 197	this_cpu_ptr(var);		\
 198})
 199#define slub_put_cpu_ptr(var)		\
 200do {					\
 201	(void)(var);			\
 202	migrate_enable();		\
 203} while (0)
 204#define USE_LOCKLESS_FAST_PATH()	(false)
 205#endif
 206
 207#ifndef CONFIG_SLUB_TINY
 208#define __fastpath_inline __always_inline
 209#else
 210#define __fastpath_inline
 211#endif
 212
 213#ifdef CONFIG_SLUB_DEBUG
 214#ifdef CONFIG_SLUB_DEBUG_ON
 215DEFINE_STATIC_KEY_TRUE(slub_debug_enabled);
 216#else
 217DEFINE_STATIC_KEY_FALSE(slub_debug_enabled);
 218#endif
 219#endif		/* CONFIG_SLUB_DEBUG */
 220
 221#ifdef CONFIG_NUMA
 222static DEFINE_STATIC_KEY_FALSE(strict_numa);
 223#endif
 224
 225/* Structure holding parameters for get_partial() call chain */
 226struct partial_context {
 227	gfp_t flags;
 228	unsigned int orig_size;
 229	void *object;
 230};
 231
 232static inline bool kmem_cache_debug(struct kmem_cache *s)
 233{
 234	return kmem_cache_debug_flags(s, SLAB_DEBUG_FLAGS);
 235}
 236
 237void *fixup_red_left(struct kmem_cache *s, void *p)
 238{
 239	if (kmem_cache_debug_flags(s, SLAB_RED_ZONE))
 240		p += s->red_left_pad;
 241
 242	return p;
 243}
 244
 245static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
 246{
 247#ifdef CONFIG_SLUB_CPU_PARTIAL
 248	return !kmem_cache_debug(s);
 249#else
 250	return false;
 251#endif
 252}
 253
 254/*
 255 * Issues still to be resolved:
 256 *
 257 * - Support PAGE_ALLOC_DEBUG. Should be easy to do.
 258 *
 259 * - Variable sizing of the per node arrays
 260 */
 261
 
 
 
 262/* Enable to log cmpxchg failures */
 263#undef SLUB_DEBUG_CMPXCHG
 264
 265#ifndef CONFIG_SLUB_TINY
 266/*
 267 * Minimum number of partial slabs. These will be left on the partial
 268 * lists even if they are empty. kmem_cache_shrink may reclaim them.
 269 */
 270#define MIN_PARTIAL 5
 271
 272/*
 273 * Maximum number of desirable partial slabs.
 274 * The existence of more partial slabs makes kmem_cache_shrink
 275 * sort the partial list by the number of objects in use.
 276 */
 277#define MAX_PARTIAL 10
 278#else
 279#define MIN_PARTIAL 0
 280#define MAX_PARTIAL 0
 281#endif
 282
 283#define DEBUG_DEFAULT_FLAGS (SLAB_CONSISTENCY_CHECKS | SLAB_RED_ZONE | \
 284				SLAB_POISON | SLAB_STORE_USER)
 285
 286/*
 287 * These debug flags cannot use CMPXCHG because there might be consistency
 288 * issues when checking or reading debug information
 289 */
 290#define SLAB_NO_CMPXCHG (SLAB_CONSISTENCY_CHECKS | SLAB_STORE_USER | \
 291				SLAB_TRACE)
 292
 293
 294/*
 295 * Debugging flags that require metadata to be stored in the slab.  These get
 296 * disabled when slab_debug=O is used and a cache's min order increases with
 297 * metadata.
 298 */
 299#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
 300
 301#define OO_SHIFT	16
 302#define OO_MASK		((1 << OO_SHIFT) - 1)
 303#define MAX_OBJS_PER_PAGE	32767 /* since slab.objects is u15 */
 304
 305/* Internal SLUB flags */
 306/* Poison object */
 307#define __OBJECT_POISON		__SLAB_FLAG_BIT(_SLAB_OBJECT_POISON)
 308/* Use cmpxchg_double */
 309
 310#ifdef system_has_freelist_aba
 311#define __CMPXCHG_DOUBLE	__SLAB_FLAG_BIT(_SLAB_CMPXCHG_DOUBLE)
 312#else
 313#define __CMPXCHG_DOUBLE	__SLAB_FLAG_UNUSED
 314#endif
 315
 316/*
 317 * Tracking user of a slab.
 318 */
 319#define TRACK_ADDRS_COUNT 16
 320struct track {
 321	unsigned long addr;	/* Called from address */
 322#ifdef CONFIG_STACKDEPOT
 323	depot_stack_handle_t handle;
 324#endif
 325	int cpu;		/* Was running on cpu */
 326	int pid;		/* Pid context */
 327	unsigned long when;	/* When did the operation occur */
 328};
 329
 330enum track_item { TRACK_ALLOC, TRACK_FREE };
 331
 332#ifdef SLAB_SUPPORTS_SYSFS
 333static int sysfs_slab_add(struct kmem_cache *);
 334static int sysfs_slab_alias(struct kmem_cache *, const char *);
 
 335#else
 336static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
 337static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
 338							{ return 0; }
 
 339#endif
 340
 341#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG)
 342static void debugfs_slab_add(struct kmem_cache *);
 343#else
 344static inline void debugfs_slab_add(struct kmem_cache *s) { }
 345#endif
 346
 347enum stat_item {
 348	ALLOC_FASTPATH,		/* Allocation from cpu slab */
 349	ALLOC_SLOWPATH,		/* Allocation by getting a new cpu slab */
 350	FREE_FASTPATH,		/* Free to cpu slab */
 351	FREE_SLOWPATH,		/* Freeing not to cpu slab */
 352	FREE_FROZEN,		/* Freeing to frozen slab */
 353	FREE_ADD_PARTIAL,	/* Freeing moves slab to partial list */
 354	FREE_REMOVE_PARTIAL,	/* Freeing removes last object */
 355	ALLOC_FROM_PARTIAL,	/* Cpu slab acquired from node partial list */
 356	ALLOC_SLAB,		/* Cpu slab acquired from page allocator */
 357	ALLOC_REFILL,		/* Refill cpu slab from slab freelist */
 358	ALLOC_NODE_MISMATCH,	/* Switching cpu slab */
 359	FREE_SLAB,		/* Slab freed to the page allocator */
 360	CPUSLAB_FLUSH,		/* Abandoning of the cpu slab */
 361	DEACTIVATE_FULL,	/* Cpu slab was full when deactivated */
 362	DEACTIVATE_EMPTY,	/* Cpu slab was empty when deactivated */
 363	DEACTIVATE_TO_HEAD,	/* Cpu slab was moved to the head of partials */
 364	DEACTIVATE_TO_TAIL,	/* Cpu slab was moved to the tail of partials */
 365	DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
 366	DEACTIVATE_BYPASS,	/* Implicit deactivation */
 367	ORDER_FALLBACK,		/* Number of times fallback was necessary */
 368	CMPXCHG_DOUBLE_CPU_FAIL,/* Failures of this_cpu_cmpxchg_double */
 369	CMPXCHG_DOUBLE_FAIL,	/* Failures of slab freelist update */
 370	CPU_PARTIAL_ALLOC,	/* Used cpu partial on alloc */
 371	CPU_PARTIAL_FREE,	/* Refill cpu partial on free */
 372	CPU_PARTIAL_NODE,	/* Refill cpu partial from node partial */
 373	CPU_PARTIAL_DRAIN,	/* Drain cpu partial to node partial */
 374	NR_SLUB_STAT_ITEMS
 375};
 376
 377#ifndef CONFIG_SLUB_TINY
 378/*
 379 * When changing the layout, make sure freelist and tid are still compatible
 380 * with this_cpu_cmpxchg_double() alignment requirements.
 381 */
 382struct kmem_cache_cpu {
 383	union {
 384		struct {
 385			void **freelist;	/* Pointer to next available object */
 386			unsigned long tid;	/* Globally unique transaction id */
 387		};
 388		freelist_aba_t freelist_tid;
 389	};
 390	struct slab *slab;	/* The slab from which we are allocating */
 391#ifdef CONFIG_SLUB_CPU_PARTIAL
 392	struct slab *partial;	/* Partially allocated slabs */
 393#endif
 394	local_lock_t lock;	/* Protects the fields above */
 395#ifdef CONFIG_SLUB_STATS
 396	unsigned int stat[NR_SLUB_STAT_ITEMS];
 397#endif
 398};
 399#endif /* CONFIG_SLUB_TINY */
 400
 401static inline void stat(const struct kmem_cache *s, enum stat_item si)
 402{
 403#ifdef CONFIG_SLUB_STATS
 404	/*
 405	 * The rmw is racy on a preemptible kernel but this is acceptable, so
 406	 * avoid this_cpu_add()'s irq-disable overhead.
 407	 */
 408	raw_cpu_inc(s->cpu_slab->stat[si]);
 409#endif
 410}
 411
 412static inline
 413void stat_add(const struct kmem_cache *s, enum stat_item si, int v)
 414{
 415#ifdef CONFIG_SLUB_STATS
 416	raw_cpu_add(s->cpu_slab->stat[si], v);
 417#endif
 418}
 419
 420/*
 421 * The slab lists for all objects.
 422 */
 423struct kmem_cache_node {
 424	spinlock_t list_lock;
 425	unsigned long nr_partial;
 426	struct list_head partial;
 427#ifdef CONFIG_SLUB_DEBUG
 428	atomic_long_t nr_slabs;
 429	atomic_long_t total_objects;
 430	struct list_head full;
 431#endif
 432};
 433
 434static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
 435{
 436	return s->node[node];
 437}
 438
 439/*
 440 * Iterator over all nodes. The body will be executed for each node that has
 441 * a kmem_cache_node structure allocated (which is true for all online nodes)
 442 */
 443#define for_each_kmem_cache_node(__s, __node, __n) \
 444	for (__node = 0; __node < nr_node_ids; __node++) \
 445		 if ((__n = get_node(__s, __node)))
 446
 447/*
 448 * Tracks for which NUMA nodes we have kmem_cache_nodes allocated.
 449 * Corresponds to node_state[N_NORMAL_MEMORY], but can temporarily
 450 * differ during memory hotplug/hotremove operations.
 451 * Protected by slab_mutex.
 452 */
 453static nodemask_t slab_nodes;
 454
 455#ifndef CONFIG_SLUB_TINY
 456/*
 457 * Workqueue used for flush_cpu_slab().
 458 */
 459static struct workqueue_struct *flushwq;
 460#endif
 461
 462/********************************************************************
 463 * 			Core slab cache functions
 464 *******************************************************************/
 465
 466/*
 467 * Returns freelist pointer (ptr). With hardening, this is obfuscated
 468 * with an XOR of the address where the pointer is held and a per-cache
 469 * random number.
 470 */
 471static inline freeptr_t freelist_ptr_encode(const struct kmem_cache *s,
 472					    void *ptr, unsigned long ptr_addr)
 473{
 474	unsigned long encoded;
 475
 476#ifdef CONFIG_SLAB_FREELIST_HARDENED
 477	encoded = (unsigned long)ptr ^ s->random ^ swab(ptr_addr);
 478#else
 479	encoded = (unsigned long)ptr;
 480#endif
 481	return (freeptr_t){.v = encoded};
 482}
 483
 484static inline void *freelist_ptr_decode(const struct kmem_cache *s,
 485					freeptr_t ptr, unsigned long ptr_addr)
 486{
 487	void *decoded;
 488
 489#ifdef CONFIG_SLAB_FREELIST_HARDENED
 490	decoded = (void *)(ptr.v ^ s->random ^ swab(ptr_addr));
 491#else
 492	decoded = (void *)ptr.v;
 493#endif
 494	return decoded;
 495}
 496
 497static inline void *get_freepointer(struct kmem_cache *s, void *object)
 498{
 499	unsigned long ptr_addr;
 500	freeptr_t p;
 501
 502	object = kasan_reset_tag(object);
 503	ptr_addr = (unsigned long)object + s->offset;
 504	p = *(freeptr_t *)(ptr_addr);
 505	return freelist_ptr_decode(s, p, ptr_addr);
 506}
 507
 508#ifndef CONFIG_SLUB_TINY
 509static void prefetch_freepointer(const struct kmem_cache *s, void *object)
 510{
 511	prefetchw(object + s->offset);
 512}
 513#endif
 514
 515/*
 516 * When running under KMSAN, get_freepointer_safe() may return an uninitialized
 517 * pointer value in the case the current thread loses the race for the next
 518 * memory chunk in the freelist. In that case this_cpu_cmpxchg_double() in
 519 * slab_alloc_node() will fail, so the uninitialized value won't be used, but
 520 * KMSAN will still check all arguments of cmpxchg because of imperfect
 521 * handling of inline assembly.
 522 * To work around this problem, we apply __no_kmsan_checks to ensure that
 523 * get_freepointer_safe() returns initialized memory.
 524 */
 525__no_kmsan_checks
 526static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
 527{
 528	unsigned long freepointer_addr;
 529	freeptr_t p;
 530
 531	if (!debug_pagealloc_enabled_static())
 532		return get_freepointer(s, object);
 533
 534	object = kasan_reset_tag(object);
 535	freepointer_addr = (unsigned long)object + s->offset;
 536	copy_from_kernel_nofault(&p, (freeptr_t *)freepointer_addr, sizeof(p));
 537	return freelist_ptr_decode(s, p, freepointer_addr);
 538}
 539
 540static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
 541{
 542	unsigned long freeptr_addr = (unsigned long)object + s->offset;
 543
 544#ifdef CONFIG_SLAB_FREELIST_HARDENED
 545	BUG_ON(object == fp); /* naive detection of double free or corruption */
 546#endif
 547
 548	freeptr_addr = (unsigned long)kasan_reset_tag((void *)freeptr_addr);
 549	*(freeptr_t *)freeptr_addr = freelist_ptr_encode(s, fp, freeptr_addr);
 550}
 551
 552/*
 553 * See comment in calculate_sizes().
 554 */
 555static inline bool freeptr_outside_object(struct kmem_cache *s)
 556{
 557	return s->offset >= s->inuse;
 558}
 559
 560/*
 561 * Return offset of the end of info block which is inuse + free pointer if
 562 * not overlapping with object.
 563 */
 564static inline unsigned int get_info_end(struct kmem_cache *s)
 565{
 566	if (freeptr_outside_object(s))
 567		return s->inuse + sizeof(void *);
 568	else
 569		return s->inuse;
 570}
 571
 572/* Loop over all objects in a slab */
 573#define for_each_object(__p, __s, __addr, __objects) \
 574	for (__p = fixup_red_left(__s, __addr); \
 575		__p < (__addr) + (__objects) * (__s)->size; \
 576		__p += (__s)->size)
 577
 578static inline unsigned int order_objects(unsigned int order, unsigned int size)
 
 
 
 
 
 
 579{
 580	return ((unsigned int)PAGE_SIZE << order) / size;
 581}
 582
 583static inline struct kmem_cache_order_objects oo_make(unsigned int order,
 584		unsigned int size)
 
 
 
 
 
 585{
 586	struct kmem_cache_order_objects x = {
 587		(order << OO_SHIFT) + order_objects(order, size)
 588	};
 589
 590	return x;
 591}
 592
 593static inline unsigned int oo_order(struct kmem_cache_order_objects x)
 594{
 595	return x.x >> OO_SHIFT;
 596}
 597
 598static inline unsigned int oo_objects(struct kmem_cache_order_objects x)
 599{
 600	return x.x & OO_MASK;
 601}
 602
 603#ifdef CONFIG_SLUB_CPU_PARTIAL
 604static void slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects)
 605{
 606	unsigned int nr_slabs;
 607
 608	s->cpu_partial = nr_objects;
 609
 610	/*
 611	 * We take the number of objects but actually limit the number of
 612	 * slabs on the per cpu partial list, in order to limit excessive
 613	 * growth of the list. For simplicity we assume that the slabs will
 614	 * be half-full.
 615	 */
 616	nr_slabs = DIV_ROUND_UP(nr_objects * 2, oo_objects(s->oo));
 617	s->cpu_partial_slabs = nr_slabs;
 618}
 619
 620static inline unsigned int slub_get_cpu_partial(struct kmem_cache *s)
 621{
 622	return s->cpu_partial_slabs;
 623}
 624#else
 625static inline void
 626slub_set_cpu_partial(struct kmem_cache *s, unsigned int nr_objects)
 627{
 628}
 629
 630static inline unsigned int slub_get_cpu_partial(struct kmem_cache *s)
 631{
 632	return 0;
 633}
 634#endif /* CONFIG_SLUB_CPU_PARTIAL */
 635
 636/*
 637 * Per slab locking using the pagelock
 638 */
 639static __always_inline void slab_lock(struct slab *slab)
 640{
 641	bit_spin_lock(PG_locked, &slab->__page_flags);
 
 642}
 643
 644static __always_inline void slab_unlock(struct slab *slab)
 645{
 646	bit_spin_unlock(PG_locked, &slab->__page_flags);
 
 647}
 648
 649static inline bool
 650__update_freelist_fast(struct slab *slab,
 651		      void *freelist_old, unsigned long counters_old,
 652		      void *freelist_new, unsigned long counters_new)
 653{
 654#ifdef system_has_freelist_aba
 655	freelist_aba_t old = { .freelist = freelist_old, .counter = counters_old };
 656	freelist_aba_t new = { .freelist = freelist_new, .counter = counters_new };
 657
 658	return try_cmpxchg_freelist(&slab->freelist_counter.full, &old.full, new.full);
 659#else
 660	return false;
 661#endif
 662}
 663
 664static inline bool
 665__update_freelist_slow(struct slab *slab,
 666		      void *freelist_old, unsigned long counters_old,
 667		      void *freelist_new, unsigned long counters_new)
 668{
 669	bool ret = false;
 670
 671	slab_lock(slab);
 672	if (slab->freelist == freelist_old &&
 673	    slab->counters == counters_old) {
 674		slab->freelist = freelist_new;
 675		slab->counters = counters_new;
 676		ret = true;
 677	}
 678	slab_unlock(slab);
 679
 680	return ret;
 681}
 682
 683/*
 684 * Interrupts must be disabled (for the fallback code to work right), typically
 685 * by an _irqsave() lock variant. On PREEMPT_RT the preempt_disable(), which is
 686 * part of bit_spin_lock(), is sufficient because the policy is not to allow any
 687 * allocation/ free operation in hardirq context. Therefore nothing can
 688 * interrupt the operation.
 689 */
 690static inline bool __slab_update_freelist(struct kmem_cache *s, struct slab *slab,
 691		void *freelist_old, unsigned long counters_old,
 692		void *freelist_new, unsigned long counters_new,
 693		const char *n)
 694{
 695	bool ret;
 696
 697	if (USE_LOCKLESS_FAST_PATH())
 698		lockdep_assert_irqs_disabled();
 699
 700	if (s->flags & __CMPXCHG_DOUBLE) {
 701		ret = __update_freelist_fast(slab, freelist_old, counters_old,
 702				            freelist_new, counters_new);
 703	} else {
 704		ret = __update_freelist_slow(slab, freelist_old, counters_old,
 705				            freelist_new, counters_new);
 
 
 
 
 
 
 
 
 
 
 
 706	}
 707	if (likely(ret))
 708		return true;
 709
 710	cpu_relax();
 711	stat(s, CMPXCHG_DOUBLE_FAIL);
 712
 713#ifdef SLUB_DEBUG_CMPXCHG
 714	pr_info("%s %s: cmpxchg double redo ", n, s->name);
 715#endif
 716
 717	return false;
 718}
 719
 720static inline bool slab_update_freelist(struct kmem_cache *s, struct slab *slab,
 721		void *freelist_old, unsigned long counters_old,
 722		void *freelist_new, unsigned long counters_new,
 723		const char *n)
 724{
 725	bool ret;
 726
 727	if (s->flags & __CMPXCHG_DOUBLE) {
 728		ret = __update_freelist_fast(slab, freelist_old, counters_old,
 729				            freelist_new, counters_new);
 730	} else {
 
 
 
 
 731		unsigned long flags;
 732
 733		local_irq_save(flags);
 734		ret = __update_freelist_slow(slab, freelist_old, counters_old,
 735				            freelist_new, counters_new);
 
 
 
 
 
 
 
 
 736		local_irq_restore(flags);
 737	}
 738	if (likely(ret))
 739		return true;
 740
 741	cpu_relax();
 742	stat(s, CMPXCHG_DOUBLE_FAIL);
 743
 744#ifdef SLUB_DEBUG_CMPXCHG
 745	pr_info("%s %s: cmpxchg double redo ", n, s->name);
 746#endif
 747
 748	return false;
 749}
 750
 
 751/*
 752 * kmalloc caches has fixed sizes (mostly power of 2), and kmalloc() API
 753 * family will round up the real request size to these fixed ones, so
 754 * there could be an extra area than what is requested. Save the original
 755 * request size in the meta data area, for better debug and sanity check.
 756 */
 757static inline void set_orig_size(struct kmem_cache *s,
 758				void *object, unsigned int orig_size)
 759{
 760	void *p = kasan_reset_tag(object);
 761
 762	if (!slub_debug_orig_size(s))
 763		return;
 764
 765	p += get_info_end(s);
 766	p += sizeof(struct track) * 2;
 767
 768	*(unsigned int *)p = orig_size;
 769}
 770
 771static inline unsigned int get_orig_size(struct kmem_cache *s, void *object)
 772{
 773	void *p = kasan_reset_tag(object);
 774
 775	if (is_kfence_address(object))
 776		return kfence_ksize(object);
 777
 778	if (!slub_debug_orig_size(s))
 779		return s->object_size;
 780
 781	p += get_info_end(s);
 782	p += sizeof(struct track) * 2;
 783
 784	return *(unsigned int *)p;
 785}
 786
 787#ifdef CONFIG_SLUB_DEBUG
 788static unsigned long object_map[BITS_TO_LONGS(MAX_OBJS_PER_PAGE)];
 789static DEFINE_SPINLOCK(object_map_lock);
 790
 791static void __fill_map(unsigned long *obj_map, struct kmem_cache *s,
 792		       struct slab *slab)
 793{
 794	void *addr = slab_address(slab);
 795	void *p;
 
 796
 797	bitmap_zero(obj_map, slab->objects);
 798
 799	for (p = slab->freelist; p; p = get_freepointer(s, p))
 800		set_bit(__obj_to_index(s, addr, p), obj_map);
 801}
 802
 803#if IS_ENABLED(CONFIG_KUNIT)
 804static bool slab_add_kunit_errors(void)
 805{
 806	struct kunit_resource *resource;
 807
 808	if (!kunit_get_current_test())
 809		return false;
 810
 811	resource = kunit_find_named_resource(current->kunit_test, "slab_errors");
 812	if (!resource)
 813		return false;
 814
 815	(*(int *)resource->data)++;
 816	kunit_put_resource(resource);
 817	return true;
 818}
 819
 820bool slab_in_kunit_test(void)
 821{
 822	struct kunit_resource *resource;
 823
 824	if (!kunit_get_current_test())
 825		return false;
 826
 827	resource = kunit_find_named_resource(current->kunit_test, "slab_errors");
 828	if (!resource)
 829		return false;
 830
 831	kunit_put_resource(resource);
 832	return true;
 833}
 834#else
 835static inline bool slab_add_kunit_errors(void) { return false; }
 836#endif
 837
 838static inline unsigned int size_from_object(struct kmem_cache *s)
 839{
 840	if (s->flags & SLAB_RED_ZONE)
 841		return s->size - s->red_left_pad;
 842
 843	return s->size;
 844}
 845
 846static inline void *restore_red_left(struct kmem_cache *s, void *p)
 847{
 848	if (s->flags & SLAB_RED_ZONE)
 849		p -= s->red_left_pad;
 850
 851	return p;
 852}
 853
 854/*
 855 * Debug settings:
 856 */
 857#if defined(CONFIG_SLUB_DEBUG_ON)
 858static slab_flags_t slub_debug = DEBUG_DEFAULT_FLAGS;
 
 
 859#else
 860static slab_flags_t slub_debug;
 861#endif
 862
 863static char *slub_debug_string;
 864static int disable_higher_order_debug;
 865
 866/*
 867 * slub is about to manipulate internal object metadata.  This memory lies
 868 * outside the range of the allocated object, so accessing it would normally
 869 * be reported by kasan as a bounds error.  metadata_access_enable() is used
 870 * to tell kasan that these accesses are OK.
 871 */
 872static inline void metadata_access_enable(void)
 873{
 874	kasan_disable_current();
 875	kmsan_disable_current();
 876}
 877
 878static inline void metadata_access_disable(void)
 879{
 880	kmsan_enable_current();
 881	kasan_enable_current();
 882}
 883
 884/*
 885 * Object debugging
 886 */
 887
 888/* Verify that a pointer has an address that is valid within a slab page */
 889static inline int check_valid_pointer(struct kmem_cache *s,
 890				struct slab *slab, void *object)
 891{
 892	void *base;
 893
 894	if (!object)
 895		return 1;
 896
 897	base = slab_address(slab);
 898	object = kasan_reset_tag(object);
 899	object = restore_red_left(s, object);
 900	if (object < base || object >= base + slab->objects * s->size ||
 901		(object - base) % s->size) {
 902		return 0;
 903	}
 904
 905	return 1;
 906}
 907
 908static void print_section(char *level, char *text, u8 *addr,
 909			  unsigned int length)
 910{
 911	metadata_access_enable();
 912	print_hex_dump(level, text, DUMP_PREFIX_ADDRESS,
 913			16, 1, kasan_reset_tag((void *)addr), length, 1);
 914	metadata_access_disable();
 915}
 916
 917static struct track *get_track(struct kmem_cache *s, void *object,
 918	enum track_item alloc)
 919{
 920	struct track *p;
 921
 922	p = object + get_info_end(s);
 923
 924	return kasan_reset_tag(p + alloc);
 925}
 926
 927#ifdef CONFIG_STACKDEPOT
 928static noinline depot_stack_handle_t set_track_prepare(void)
 929{
 930	depot_stack_handle_t handle;
 931	unsigned long entries[TRACK_ADDRS_COUNT];
 932	unsigned int nr_entries;
 933
 934	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 3);
 935	handle = stack_depot_save(entries, nr_entries, GFP_NOWAIT);
 936
 937	return handle;
 938}
 939#else
 940static inline depot_stack_handle_t set_track_prepare(void)
 941{
 942	return 0;
 943}
 944#endif
 945
 946static void set_track_update(struct kmem_cache *s, void *object,
 947			     enum track_item alloc, unsigned long addr,
 948			     depot_stack_handle_t handle)
 949{
 950	struct track *p = get_track(s, object, alloc);
 951
 952#ifdef CONFIG_STACKDEPOT
 953	p->handle = handle;
 954#endif
 955	p->addr = addr;
 956	p->cpu = smp_processor_id();
 957	p->pid = current->pid;
 958	p->when = jiffies;
 959}
 960
 961static __always_inline void set_track(struct kmem_cache *s, void *object,
 962				      enum track_item alloc, unsigned long addr)
 963{
 964	depot_stack_handle_t handle = set_track_prepare();
 965
 966	set_track_update(s, object, alloc, addr, handle);
 
 
 
 
 
 
 
 
 
 
 
 
 967}
 968
 969static void init_tracking(struct kmem_cache *s, void *object)
 970{
 971	struct track *p;
 972
 973	if (!(s->flags & SLAB_STORE_USER))
 974		return;
 975
 976	p = get_track(s, object, TRACK_ALLOC);
 977	memset(p, 0, 2*sizeof(struct track));
 978}
 979
 980static void print_track(const char *s, struct track *t, unsigned long pr_time)
 981{
 982	depot_stack_handle_t handle __maybe_unused;
 983
 984	if (!t->addr)
 985		return;
 986
 987	pr_err("%s in %pS age=%lu cpu=%u pid=%d\n",
 988	       s, (void *)t->addr, pr_time - t->when, t->cpu, t->pid);
 989#ifdef CONFIG_STACKDEPOT
 990	handle = READ_ONCE(t->handle);
 991	if (handle)
 992		stack_depot_print(handle);
 993	else
 994		pr_err("object allocation/free stack trace missing\n");
 
 
 
 995#endif
 996}
 997
 998void print_tracking(struct kmem_cache *s, void *object)
 999{
1000	unsigned long pr_time = jiffies;
1001	if (!(s->flags & SLAB_STORE_USER))
1002		return;
1003
1004	print_track("Allocated", get_track(s, object, TRACK_ALLOC), pr_time);
1005	print_track("Freed", get_track(s, object, TRACK_FREE), pr_time);
1006}
1007
1008static void print_slab_info(const struct slab *slab)
1009{
1010	pr_err("Slab 0x%p objects=%u used=%u fp=0x%p flags=%pGp\n",
1011	       slab, slab->objects, slab->inuse, slab->freelist,
1012	       &slab->__page_flags);
1013}
1014
1015void skip_orig_size_check(struct kmem_cache *s, const void *object)
1016{
1017	set_orig_size(s, (void *)object, s->object_size);
1018}
1019
1020static void slab_bug(struct kmem_cache *s, char *fmt, ...)
1021{
1022	struct va_format vaf;
1023	va_list args;
1024
1025	va_start(args, fmt);
1026	vaf.fmt = fmt;
1027	vaf.va = &args;
1028	pr_err("=============================================================================\n");
1029	pr_err("BUG %s (%s): %pV\n", s->name, print_tainted(), &vaf);
1030	pr_err("-----------------------------------------------------------------------------\n\n");
 
 
1031	va_end(args);
1032}
1033
1034__printf(2, 3)
1035static void slab_fix(struct kmem_cache *s, char *fmt, ...)
1036{
1037	struct va_format vaf;
1038	va_list args;
1039
1040	if (slab_add_kunit_errors())
1041		return;
1042
1043	va_start(args, fmt);
1044	vaf.fmt = fmt;
1045	vaf.va = &args;
1046	pr_err("FIX %s: %pV\n", s->name, &vaf);
1047	va_end(args);
1048}
1049
1050static void print_trailer(struct kmem_cache *s, struct slab *slab, u8 *p)
1051{
1052	unsigned int off;	/* Offset of last byte */
1053	u8 *addr = slab_address(slab);
1054
1055	print_tracking(s, p);
1056
1057	print_slab_info(slab);
1058
1059	pr_err("Object 0x%p @offset=%tu fp=0x%p\n\n",
1060	       p, p - addr, get_freepointer(s, p));
1061
1062	if (s->flags & SLAB_RED_ZONE)
1063		print_section(KERN_ERR, "Redzone  ", p - s->red_left_pad,
1064			      s->red_left_pad);
1065	else if (p > addr + 16)
1066		print_section(KERN_ERR, "Bytes b4 ", p - 16, 16);
1067
1068	print_section(KERN_ERR,         "Object   ", p,
1069		      min_t(unsigned int, s->object_size, PAGE_SIZE));
1070	if (s->flags & SLAB_RED_ZONE)
1071		print_section(KERN_ERR, "Redzone  ", p + s->object_size,
1072			s->inuse - s->object_size);
1073
1074	off = get_info_end(s);
 
 
 
1075
1076	if (s->flags & SLAB_STORE_USER)
1077		off += 2 * sizeof(struct track);
1078
1079	if (slub_debug_orig_size(s))
1080		off += sizeof(unsigned int);
1081
1082	off += kasan_metadata_size(s, false);
1083
1084	if (off != size_from_object(s))
1085		/* Beginning of the filler is the free pointer */
1086		print_section(KERN_ERR, "Padding  ", p + off,
1087			      size_from_object(s) - off);
1088
1089	dump_stack();
1090}
1091
1092static void object_err(struct kmem_cache *s, struct slab *slab,
1093			u8 *object, char *reason)
1094{
1095	if (slab_add_kunit_errors())
1096		return;
1097
1098	slab_bug(s, "%s", reason);
1099	print_trailer(s, slab, object);
1100	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
1101}
1102
1103static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab,
1104			       void **freelist, void *nextfree)
1105{
1106	if ((s->flags & SLAB_CONSISTENCY_CHECKS) &&
1107	    !check_valid_pointer(s, slab, nextfree) && freelist) {
1108		object_err(s, slab, *freelist, "Freechain corrupt");
1109		*freelist = NULL;
1110		slab_fix(s, "Isolate corrupted freechain");
1111		return true;
1112	}
1113
1114	return false;
1115}
1116
1117static __printf(3, 4) void slab_err(struct kmem_cache *s, struct slab *slab,
1118			const char *fmt, ...)
1119{
1120	va_list args;
1121	char buf[100];
1122
1123	if (slab_add_kunit_errors())
1124		return;
1125
1126	va_start(args, fmt);
1127	vsnprintf(buf, sizeof(buf), fmt, args);
1128	va_end(args);
1129	slab_bug(s, "%s", buf);
1130	print_slab_info(slab);
1131	dump_stack();
1132	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
1133}
1134
1135static void init_object(struct kmem_cache *s, void *object, u8 val)
1136{
1137	u8 *p = kasan_reset_tag(object);
1138	unsigned int poison_size = s->object_size;
1139
1140	if (s->flags & SLAB_RED_ZONE) {
1141		/*
1142		 * Here and below, avoid overwriting the KMSAN shadow. Keeping
1143		 * the shadow makes it possible to distinguish uninit-value
1144		 * from use-after-free.
1145		 */
1146		memset_no_sanitize_memory(p - s->red_left_pad, val,
1147					  s->red_left_pad);
1148
1149		if (slub_debug_orig_size(s) && val == SLUB_RED_ACTIVE) {
1150			/*
1151			 * Redzone the extra allocated space by kmalloc than
1152			 * requested, and the poison size will be limited to
1153			 * the original request size accordingly.
1154			 */
1155			poison_size = get_orig_size(s, object);
1156		}
1157	}
1158
1159	if (s->flags & __OBJECT_POISON) {
1160		memset_no_sanitize_memory(p, POISON_FREE, poison_size - 1);
1161		memset_no_sanitize_memory(p + poison_size - 1, POISON_END, 1);
1162	}
1163
1164	if (s->flags & SLAB_RED_ZONE)
1165		memset_no_sanitize_memory(p + poison_size, val,
1166					  s->inuse - poison_size);
1167}
1168
1169static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
1170						void *from, void *to)
1171{
1172	slab_fix(s, "Restoring %s 0x%p-0x%p=0x%x", message, from, to - 1, data);
1173	memset(from, data, to - from);
1174}
1175
1176#ifdef CONFIG_KMSAN
1177#define pad_check_attributes noinline __no_kmsan_checks
1178#else
1179#define pad_check_attributes
1180#endif
1181
1182static pad_check_attributes int
1183check_bytes_and_report(struct kmem_cache *s, struct slab *slab,
1184		       u8 *object, char *what,
1185		       u8 *start, unsigned int value, unsigned int bytes)
1186{
1187	u8 *fault;
1188	u8 *end;
1189	u8 *addr = slab_address(slab);
1190
1191	metadata_access_enable();
1192	fault = memchr_inv(kasan_reset_tag(start), value, bytes);
1193	metadata_access_disable();
1194	if (!fault)
1195		return 1;
1196
1197	end = start + bytes;
1198	while (end > fault && end[-1] == value)
1199		end--;
1200
1201	if (slab_add_kunit_errors())
1202		goto skip_bug_print;
1203
1204	slab_bug(s, "%s overwritten", what);
1205	pr_err("0x%p-0x%p @offset=%tu. First byte 0x%x instead of 0x%x\n",
1206					fault, end - 1, fault - addr,
1207					fault[0], value);
1208
1209skip_bug_print:
1210	restore_bytes(s, what, value, fault, end);
1211	return 0;
1212}
1213
1214/*
1215 * Object layout:
1216 *
1217 * object address
1218 * 	Bytes of the object to be managed.
1219 * 	If the freepointer may overlay the object then the free
1220 *	pointer is at the middle of the object.
1221 *
1222 * 	Poisoning uses 0x6b (POISON_FREE) and the last byte is
1223 * 	0xa5 (POISON_END)
1224 *
1225 * object + s->object_size
1226 * 	Padding to reach word boundary. This is also used for Redzoning.
1227 * 	Padding is extended by another word if Redzoning is enabled and
1228 * 	object_size == inuse.
1229 *
1230 * 	We fill with 0xbb (SLUB_RED_INACTIVE) for inactive objects and with
1231 * 	0xcc (SLUB_RED_ACTIVE) for objects in use.
1232 *
1233 * object + s->inuse
1234 * 	Meta data starts here.
1235 *
1236 * 	A. Free pointer (if we cannot overwrite object on free)
1237 * 	B. Tracking data for SLAB_STORE_USER
1238 *	C. Original request size for kmalloc object (SLAB_STORE_USER enabled)
1239 *	D. Padding to reach required alignment boundary or at minimum
1240 * 		one word if debugging is on to be able to detect writes
1241 * 		before the word boundary.
1242 *
1243 *	Padding is done using 0x5a (POISON_INUSE)
1244 *
1245 * object + s->size
1246 * 	Nothing is used beyond s->size.
1247 *
1248 * If slabcaches are merged then the object_size and inuse boundaries are mostly
1249 * ignored. And therefore no slab options that rely on these boundaries
1250 * may be used with merged slabcaches.
1251 */
1252
1253static int check_pad_bytes(struct kmem_cache *s, struct slab *slab, u8 *p)
1254{
1255	unsigned long off = get_info_end(s);	/* The end of info */
 
 
 
 
1256
1257	if (s->flags & SLAB_STORE_USER) {
1258		/* We also have user information there */
1259		off += 2 * sizeof(struct track);
1260
1261		if (s->flags & SLAB_KMALLOC)
1262			off += sizeof(unsigned int);
1263	}
1264
1265	off += kasan_metadata_size(s, false);
1266
1267	if (size_from_object(s) == off)
1268		return 1;
1269
1270	return check_bytes_and_report(s, slab, p, "Object padding",
1271			p + off, POISON_INUSE, size_from_object(s) - off);
1272}
1273
1274/* Check the pad bytes at the end of a slab page */
1275static pad_check_attributes void
1276slab_pad_check(struct kmem_cache *s, struct slab *slab)
1277{
1278	u8 *start;
1279	u8 *fault;
1280	u8 *end;
1281	u8 *pad;
1282	int length;
1283	int remainder;
1284
1285	if (!(s->flags & SLAB_POISON))
1286		return;
1287
1288	start = slab_address(slab);
1289	length = slab_size(slab);
1290	end = start + length;
1291	remainder = length % s->size;
1292	if (!remainder)
1293		return;
1294
1295	pad = end - remainder;
1296	metadata_access_enable();
1297	fault = memchr_inv(kasan_reset_tag(pad), POISON_INUSE, remainder);
1298	metadata_access_disable();
1299	if (!fault)
1300		return;
1301	while (end > fault && end[-1] == POISON_INUSE)
1302		end--;
1303
1304	slab_err(s, slab, "Padding overwritten. 0x%p-0x%p @offset=%tu",
1305			fault, end - 1, fault - start);
1306	print_section(KERN_ERR, "Padding ", pad, remainder);
1307
1308	restore_bytes(s, "slab padding", POISON_INUSE, fault, end);
 
1309}
1310
1311static int check_object(struct kmem_cache *s, struct slab *slab,
1312					void *object, u8 val)
1313{
1314	u8 *p = object;
1315	u8 *endobject = object + s->object_size;
1316	unsigned int orig_size, kasan_meta_size;
1317	int ret = 1;
1318
1319	if (s->flags & SLAB_RED_ZONE) {
1320		if (!check_bytes_and_report(s, slab, object, "Left Redzone",
1321			object - s->red_left_pad, val, s->red_left_pad))
1322			ret = 0;
1323
1324		if (!check_bytes_and_report(s, slab, object, "Right Redzone",
1325			endobject, val, s->inuse - s->object_size))
1326			ret = 0;
1327
1328		if (slub_debug_orig_size(s) && val == SLUB_RED_ACTIVE) {
1329			orig_size = get_orig_size(s, object);
1330
1331			if (s->object_size > orig_size  &&
1332				!check_bytes_and_report(s, slab, object,
1333					"kmalloc Redzone", p + orig_size,
1334					val, s->object_size - orig_size)) {
1335				ret = 0;
1336			}
1337		}
1338	} else {
1339		if ((s->flags & SLAB_POISON) && s->object_size < s->inuse) {
1340			if (!check_bytes_and_report(s, slab, p, "Alignment padding",
1341				endobject, POISON_INUSE,
1342				s->inuse - s->object_size))
1343				ret = 0;
1344		}
1345	}
1346
1347	if (s->flags & SLAB_POISON) {
1348		if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON)) {
1349			/*
1350			 * KASAN can save its free meta data inside of the
1351			 * object at offset 0. Thus, skip checking the part of
1352			 * the redzone that overlaps with the meta data.
1353			 */
1354			kasan_meta_size = kasan_metadata_size(s, true);
1355			if (kasan_meta_size < s->object_size - 1 &&
1356			    !check_bytes_and_report(s, slab, p, "Poison",
1357					p + kasan_meta_size, POISON_FREE,
1358					s->object_size - kasan_meta_size - 1))
1359				ret = 0;
1360			if (kasan_meta_size < s->object_size &&
1361			    !check_bytes_and_report(s, slab, p, "End Poison",
1362					p + s->object_size - 1, POISON_END, 1))
1363				ret = 0;
1364		}
1365		/*
1366		 * check_pad_bytes cleans up on its own.
1367		 */
1368		if (!check_pad_bytes(s, slab, p))
1369			ret = 0;
1370	}
1371
1372	/*
1373	 * Cannot check freepointer while object is allocated if
1374	 * object and freepointer overlap.
1375	 */
1376	if ((freeptr_outside_object(s) || val != SLUB_RED_ACTIVE) &&
1377	    !check_valid_pointer(s, slab, get_freepointer(s, p))) {
1378		object_err(s, slab, p, "Freepointer corrupt");
 
 
 
1379		/*
1380		 * No choice but to zap it and thus lose the remainder
1381		 * of the free objects in this slab. May cause
1382		 * another error because the object count is now wrong.
1383		 */
1384		set_freepointer(s, p, NULL);
1385		ret = 0;
1386	}
1387
1388	if (!ret && !slab_in_kunit_test()) {
1389		print_trailer(s, slab, object);
1390		add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
1391	}
1392
1393	return ret;
1394}
1395
1396static int check_slab(struct kmem_cache *s, struct slab *slab)
1397{
1398	int maxobj;
1399
1400	if (!folio_test_slab(slab_folio(slab))) {
1401		slab_err(s, slab, "Not a valid slab page");
1402		return 0;
1403	}
1404
1405	maxobj = order_objects(slab_order(slab), s->size);
1406	if (slab->objects > maxobj) {
1407		slab_err(s, slab, "objects %u > max %u",
1408			slab->objects, maxobj);
1409		return 0;
1410	}
1411	if (slab->inuse > slab->objects) {
1412		slab_err(s, slab, "inuse %u > max %u",
1413			slab->inuse, slab->objects);
 
 
1414		return 0;
1415	}
1416	if (slab->frozen) {
1417		slab_err(s, slab, "Slab disabled since SLUB metadata consistency check failed");
 
1418		return 0;
1419	}
1420
1421	/* Slab_pad_check fixes things up after itself */
1422	slab_pad_check(s, slab);
1423	return 1;
1424}
1425
1426/*
1427 * Determine if a certain object in a slab is on the freelist. Must hold the
1428 * slab lock to guarantee that the chains are in a consistent state.
1429 */
1430static int on_freelist(struct kmem_cache *s, struct slab *slab, void *search)
1431{
1432	int nr = 0;
1433	void *fp;
1434	void *object = NULL;
1435	int max_objects;
1436
1437	fp = slab->freelist;
1438	while (fp && nr <= slab->objects) {
1439		if (fp == search)
1440			return 1;
1441		if (!check_valid_pointer(s, slab, fp)) {
1442			if (object) {
1443				object_err(s, slab, object,
1444					"Freechain corrupt");
1445				set_freepointer(s, object, NULL);
1446			} else {
1447				slab_err(s, slab, "Freepointer corrupt");
1448				slab->freelist = NULL;
1449				slab->inuse = slab->objects;
1450				slab_fix(s, "Freelist cleared");
1451				return 0;
1452			}
1453			break;
1454		}
1455		object = fp;
1456		fp = get_freepointer(s, object);
1457		nr++;
1458	}
1459
1460	max_objects = order_objects(slab_order(slab), s->size);
1461	if (max_objects > MAX_OBJS_PER_PAGE)
1462		max_objects = MAX_OBJS_PER_PAGE;
1463
1464	if (slab->objects != max_objects) {
1465		slab_err(s, slab, "Wrong number of objects. Found %d but should be %d",
1466			 slab->objects, max_objects);
1467		slab->objects = max_objects;
1468		slab_fix(s, "Number of objects adjusted");
1469	}
1470	if (slab->inuse != slab->objects - nr) {
1471		slab_err(s, slab, "Wrong object count. Counter is %d but counted were %d",
1472			 slab->inuse, slab->objects - nr);
1473		slab->inuse = slab->objects - nr;
1474		slab_fix(s, "Object count adjusted");
1475	}
1476	return search == NULL;
1477}
1478
1479static void trace(struct kmem_cache *s, struct slab *slab, void *object,
1480								int alloc)
1481{
1482	if (s->flags & SLAB_TRACE) {
1483		pr_info("TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
1484			s->name,
1485			alloc ? "alloc" : "free",
1486			object, slab->inuse,
1487			slab->freelist);
1488
1489		if (!alloc)
1490			print_section(KERN_INFO, "Object ", (void *)object,
1491					s->object_size);
1492
1493		dump_stack();
1494	}
1495}
1496
1497/*
1498 * Tracking of fully allocated slabs for debugging purposes.
1499 */
1500static void add_full(struct kmem_cache *s,
1501	struct kmem_cache_node *n, struct slab *slab)
1502{
1503	if (!(s->flags & SLAB_STORE_USER))
1504		return;
1505
1506	lockdep_assert_held(&n->list_lock);
1507	list_add(&slab->slab_list, &n->full);
1508}
1509
1510static void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, struct slab *slab)
1511{
1512	if (!(s->flags & SLAB_STORE_USER))
1513		return;
1514
1515	lockdep_assert_held(&n->list_lock);
1516	list_del(&slab->slab_list);
 
 
 
 
 
 
 
 
1517}
1518
1519static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
1520{
1521	return atomic_long_read(&n->nr_slabs);
1522}
1523
1524static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
1525{
1526	struct kmem_cache_node *n = get_node(s, node);
1527
1528	atomic_long_inc(&n->nr_slabs);
1529	atomic_long_add(objects, &n->total_objects);
 
 
 
 
 
 
 
 
1530}
1531static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
1532{
1533	struct kmem_cache_node *n = get_node(s, node);
1534
1535	atomic_long_dec(&n->nr_slabs);
1536	atomic_long_sub(objects, &n->total_objects);
1537}
1538
1539/* Object debug checks for alloc/free paths */
1540static void setup_object_debug(struct kmem_cache *s, void *object)
 
1541{
1542	if (!kmem_cache_debug_flags(s, SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON))
1543		return;
1544
1545	init_object(s, object, SLUB_RED_INACTIVE);
1546	init_tracking(s, object);
1547}
1548
1549static
1550void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr)
1551{
1552	if (!kmem_cache_debug_flags(s, SLAB_POISON))
1553		return;
1554
1555	metadata_access_enable();
1556	memset(kasan_reset_tag(addr), POISON_INUSE, slab_size(slab));
1557	metadata_access_disable();
1558}
1559
1560static inline int alloc_consistency_checks(struct kmem_cache *s,
1561					struct slab *slab, void *object)
 
1562{
1563	if (!check_slab(s, slab))
1564		return 0;
1565
1566	if (!check_valid_pointer(s, slab, object)) {
1567		object_err(s, slab, object, "Freelist Pointer check fails");
1568		return 0;
1569	}
1570
1571	if (!check_object(s, slab, object, SLUB_RED_INACTIVE))
1572		return 0;
1573
1574	return 1;
1575}
1576
1577static noinline bool alloc_debug_processing(struct kmem_cache *s,
1578			struct slab *slab, void *object, int orig_size)
 
1579{
1580	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
1581		if (!alloc_consistency_checks(s, slab, object))
1582			goto bad;
1583	}
1584
1585	/* Success. Perform special debug activities for allocs */
1586	trace(s, slab, object, 1);
1587	set_orig_size(s, object, orig_size);
 
1588	init_object(s, object, SLUB_RED_ACTIVE);
1589	return true;
1590
1591bad:
1592	if (folio_test_slab(slab_folio(slab))) {
1593		/*
1594		 * If this is a slab page then lets do the best we can
1595		 * to avoid issues in the future. Marking all objects
1596		 * as used avoids touching the remaining objects.
1597		 */
1598		slab_fix(s, "Marking all objects used");
1599		slab->inuse = slab->objects;
1600		slab->freelist = NULL;
1601		slab->frozen = 1; /* mark consistency-failed slab as frozen */
1602	}
1603	return false;
1604}
1605
1606static inline int free_consistency_checks(struct kmem_cache *s,
1607		struct slab *slab, void *object, unsigned long addr)
1608{
1609	if (!check_valid_pointer(s, slab, object)) {
1610		slab_err(s, slab, "Invalid object pointer 0x%p", object);
1611		return 0;
1612	}
1613
1614	if (on_freelist(s, slab, object)) {
1615		object_err(s, slab, object, "Object already free");
1616		return 0;
1617	}
1618
1619	if (!check_object(s, slab, object, SLUB_RED_ACTIVE))
1620		return 0;
1621
1622	if (unlikely(s != slab->slab_cache)) {
1623		if (!folio_test_slab(slab_folio(slab))) {
1624			slab_err(s, slab, "Attempt to free object(0x%p) outside of slab",
1625				 object);
1626		} else if (!slab->slab_cache) {
1627			pr_err("SLUB <none>: no slab for object 0x%p.\n",
1628			       object);
1629			dump_stack();
1630		} else
1631			object_err(s, slab, object,
1632					"page slab pointer corrupt.");
1633		return 0;
1634	}
1635	return 1;
1636}
1637
1638/*
1639 * Parse a block of slab_debug options. Blocks are delimited by ';'
1640 *
1641 * @str:    start of block
1642 * @flags:  returns parsed flags, or DEBUG_DEFAULT_FLAGS if none specified
1643 * @slabs:  return start of list of slabs, or NULL when there's no list
1644 * @init:   assume this is initial parsing and not per-kmem-create parsing
1645 *
1646 * returns the start of next block if there's any, or NULL
1647 */
1648static char *
1649parse_slub_debug_flags(char *str, slab_flags_t *flags, char **slabs, bool init)
1650{
1651	bool higher_order_disable = false;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1652
1653	/* Skip any completely empty blocks */
1654	while (*str && *str == ';')
1655		str++;
 
 
 
 
 
 
 
 
 
 
 
 
1656
1657	if (*str == ',') {
1658		/*
1659		 * No options but restriction on slabs. This means full
1660		 * debugging for slabs matching a pattern.
1661		 */
1662		*flags = DEBUG_DEFAULT_FLAGS;
1663		goto check_slabs;
1664	}
1665	*flags = 0;
1666
1667	/* Determine which debug features should be switched on */
1668	for (; *str && *str != ',' && *str != ';'; str++) {
 
 
 
 
 
 
 
 
 
1669		switch (tolower(*str)) {
1670		case '-':
1671			*flags = 0;
1672			break;
1673		case 'f':
1674			*flags |= SLAB_CONSISTENCY_CHECKS;
1675			break;
1676		case 'z':
1677			*flags |= SLAB_RED_ZONE;
1678			break;
1679		case 'p':
1680			*flags |= SLAB_POISON;
1681			break;
1682		case 'u':
1683			*flags |= SLAB_STORE_USER;
1684			break;
1685		case 't':
1686			*flags |= SLAB_TRACE;
1687			break;
1688		case 'a':
1689			*flags |= SLAB_FAILSLAB;
1690			break;
1691		case 'o':
1692			/*
1693			 * Avoid enabling debugging on caches if its minimum
1694			 * order would increase as a result.
1695			 */
1696			higher_order_disable = true;
1697			break;
1698		default:
1699			if (init)
1700				pr_err("slab_debug option '%c' unknown. skipped\n", *str);
1701		}
1702	}
 
1703check_slabs:
1704	if (*str == ',')
1705		*slabs = ++str;
1706	else
1707		*slabs = NULL;
1708
1709	/* Skip over the slab list */
1710	while (*str && *str != ';')
1711		str++;
1712
1713	/* Skip any completely empty blocks */
1714	while (*str && *str == ';')
1715		str++;
1716
1717	if (init && higher_order_disable)
1718		disable_higher_order_debug = 1;
1719
1720	if (*str)
1721		return str;
1722	else
1723		return NULL;
1724}
1725
1726static int __init setup_slub_debug(char *str)
1727{
1728	slab_flags_t flags;
1729	slab_flags_t global_flags;
1730	char *saved_str;
1731	char *slab_list;
1732	bool global_slub_debug_changed = false;
1733	bool slab_list_specified = false;
1734
1735	global_flags = DEBUG_DEFAULT_FLAGS;
1736	if (*str++ != '=' || !*str)
1737		/*
1738		 * No options specified. Switch on full debugging.
1739		 */
1740		goto out;
1741
1742	saved_str = str;
1743	while (str) {
1744		str = parse_slub_debug_flags(str, &flags, &slab_list, true);
1745
1746		if (!slab_list) {
1747			global_flags = flags;
1748			global_slub_debug_changed = true;
1749		} else {
1750			slab_list_specified = true;
1751			if (flags & SLAB_STORE_USER)
1752				stack_depot_request_early_init();
1753		}
1754	}
1755
1756	/*
1757	 * For backwards compatibility, a single list of flags with list of
1758	 * slabs means debugging is only changed for those slabs, so the global
1759	 * slab_debug should be unchanged (0 or DEBUG_DEFAULT_FLAGS, depending
1760	 * on CONFIG_SLUB_DEBUG_ON). We can extended that to multiple lists as
1761	 * long as there is no option specifying flags without a slab list.
1762	 */
1763	if (slab_list_specified) {
1764		if (!global_slub_debug_changed)
1765			global_flags = slub_debug;
1766		slub_debug_string = saved_str;
1767	}
1768out:
1769	slub_debug = global_flags;
1770	if (slub_debug & SLAB_STORE_USER)
1771		stack_depot_request_early_init();
1772	if (slub_debug != 0 || slub_debug_string)
1773		static_branch_enable(&slub_debug_enabled);
1774	else
1775		static_branch_disable(&slub_debug_enabled);
1776	if ((static_branch_unlikely(&init_on_alloc) ||
1777	     static_branch_unlikely(&init_on_free)) &&
1778	    (slub_debug & SLAB_POISON))
1779		pr_info("mem auto-init: SLAB_POISON will take precedence over init_on_alloc/init_on_free\n");
1780	return 1;
1781}
1782
1783__setup("slab_debug", setup_slub_debug);
1784__setup_param("slub_debug", slub_debug, setup_slub_debug, 0);
1785
1786/*
1787 * kmem_cache_flags - apply debugging options to the cache
1788 * @flags:		flags to set
1789 * @name:		name of the cache
1790 *
1791 * Debug option(s) are applied to @flags. In addition to the debug
1792 * option(s), if a slab name (or multiple) is specified i.e.
1793 * slab_debug=<Debug-Options>,<slab name1>,<slab name2> ...
1794 * then only the select slabs will receive the debug option(s).
1795 */
1796slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name)
1797{
1798	char *iter;
1799	size_t len;
1800	char *next_block;
1801	slab_flags_t block_flags;
1802	slab_flags_t slub_debug_local = slub_debug;
1803
1804	if (flags & SLAB_NO_USER_FLAGS)
1805		return flags;
1806
1807	/*
1808	 * If the slab cache is for debugging (e.g. kmemleak) then
1809	 * don't store user (stack trace) information by default,
1810	 * but let the user enable it via the command line below.
1811	 */
1812	if (flags & SLAB_NOLEAKTRACE)
1813		slub_debug_local &= ~SLAB_STORE_USER;
1814
1815	len = strlen(name);
1816	next_block = slub_debug_string;
1817	/* Go through all blocks of debug options, see if any matches our slab's name */
1818	while (next_block) {
1819		next_block = parse_slub_debug_flags(next_block, &block_flags, &iter, false);
1820		if (!iter)
1821			continue;
1822		/* Found a block that has a slab list, search it */
1823		while (*iter) {
1824			char *end, *glob;
1825			size_t cmplen;
1826
1827			end = strchrnul(iter, ',');
1828			if (next_block && next_block < end)
1829				end = next_block - 1;
1830
1831			glob = strnchr(iter, end - iter, '*');
1832			if (glob)
1833				cmplen = glob - iter;
1834			else
1835				cmplen = max_t(size_t, len, (end - iter));
1836
1837			if (!strncmp(name, iter, cmplen)) {
1838				flags |= block_flags;
1839				return flags;
1840			}
1841
1842			if (!*end || *end == ';')
1843				break;
1844			iter = end + 1;
1845		}
1846	}
1847
1848	return flags | slub_debug_local;
1849}
1850#else /* !CONFIG_SLUB_DEBUG */
1851static inline void setup_object_debug(struct kmem_cache *s, void *object) {}
1852static inline
1853void setup_slab_debug(struct kmem_cache *s, struct slab *slab, void *addr) {}
1854
1855static inline bool alloc_debug_processing(struct kmem_cache *s,
1856	struct slab *slab, void *object, int orig_size) { return true; }
1857
1858static inline bool free_debug_processing(struct kmem_cache *s,
1859	struct slab *slab, void *head, void *tail, int *bulk_cnt,
1860	unsigned long addr, depot_stack_handle_t handle) { return true; }
 
1861
1862static inline void slab_pad_check(struct kmem_cache *s, struct slab *slab) {}
1863static inline int check_object(struct kmem_cache *s, struct slab *slab,
 
1864			void *object, u8 val) { return 1; }
1865static inline depot_stack_handle_t set_track_prepare(void) { return 0; }
1866static inline void set_track(struct kmem_cache *s, void *object,
1867			     enum track_item alloc, unsigned long addr) {}
1868static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
1869					struct slab *slab) {}
1870static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n,
1871					struct slab *slab) {}
1872slab_flags_t kmem_cache_flags(slab_flags_t flags, const char *name)
 
 
1873{
1874	return flags;
1875}
1876#define slub_debug 0
1877
1878#define disable_higher_order_debug 0
1879
 
 
1880static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
1881							{ return 0; }
1882static inline void inc_slabs_node(struct kmem_cache *s, int node,
1883							int objects) {}
1884static inline void dec_slabs_node(struct kmem_cache *s, int node,
1885							int objects) {}
1886#ifndef CONFIG_SLUB_TINY
1887static bool freelist_corrupted(struct kmem_cache *s, struct slab *slab,
1888			       void **freelist, void *nextfree)
1889{
1890	return false;
1891}
1892#endif
1893#endif /* CONFIG_SLUB_DEBUG */
1894
1895#ifdef CONFIG_SLAB_OBJ_EXT
1896
1897#ifdef CONFIG_MEM_ALLOC_PROFILING_DEBUG
1898
1899static inline void mark_objexts_empty(struct slabobj_ext *obj_exts)
1900{
1901	struct slabobj_ext *slab_exts;
1902	struct slab *obj_exts_slab;
1903
1904	obj_exts_slab = virt_to_slab(obj_exts);
1905	slab_exts = slab_obj_exts(obj_exts_slab);
1906	if (slab_exts) {
1907		unsigned int offs = obj_to_index(obj_exts_slab->slab_cache,
1908						 obj_exts_slab, obj_exts);
1909		/* codetag should be NULL */
1910		WARN_ON(slab_exts[offs].ref.ct);
1911		set_codetag_empty(&slab_exts[offs].ref);
1912	}
1913}
1914
1915static inline void mark_failed_objexts_alloc(struct slab *slab)
1916{
1917	slab->obj_exts = OBJEXTS_ALLOC_FAIL;
1918}
1919
1920static inline void handle_failed_objexts_alloc(unsigned long obj_exts,
1921			struct slabobj_ext *vec, unsigned int objects)
1922{
1923	/*
1924	 * If vector previously failed to allocate then we have live
1925	 * objects with no tag reference. Mark all references in this
1926	 * vector as empty to avoid warnings later on.
1927	 */
1928	if (obj_exts & OBJEXTS_ALLOC_FAIL) {
1929		unsigned int i;
1930
1931		for (i = 0; i < objects; i++)
1932			set_codetag_empty(&vec[i].ref);
1933	}
1934}
1935
1936#else /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
1937
1938static inline void mark_objexts_empty(struct slabobj_ext *obj_exts) {}
1939static inline void mark_failed_objexts_alloc(struct slab *slab) {}
1940static inline void handle_failed_objexts_alloc(unsigned long obj_exts,
1941			struct slabobj_ext *vec, unsigned int objects) {}
1942
1943#endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */
1944
1945/*
1946 * The allocated objcg pointers array is not accounted directly.
1947 * Moreover, it should not come from DMA buffer and is not readily
1948 * reclaimable. So those GFP bits should be masked off.
1949 */
1950#define OBJCGS_CLEAR_MASK	(__GFP_DMA | __GFP_RECLAIMABLE | \
1951				__GFP_ACCOUNT | __GFP_NOFAIL)
1952
1953int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
1954		        gfp_t gfp, bool new_slab)
1955{
1956	unsigned int objects = objs_per_slab(s, slab);
1957	unsigned long new_exts;
1958	unsigned long old_exts;
1959	struct slabobj_ext *vec;
1960
1961	gfp &= ~OBJCGS_CLEAR_MASK;
1962	/* Prevent recursive extension vector allocation */
1963	gfp |= __GFP_NO_OBJ_EXT;
1964	vec = kcalloc_node(objects, sizeof(struct slabobj_ext), gfp,
1965			   slab_nid(slab));
1966	if (!vec) {
1967		/* Mark vectors which failed to allocate */
1968		if (new_slab)
1969			mark_failed_objexts_alloc(slab);
1970
1971		return -ENOMEM;
1972	}
1973
1974	new_exts = (unsigned long)vec;
1975#ifdef CONFIG_MEMCG
1976	new_exts |= MEMCG_DATA_OBJEXTS;
1977#endif
1978	old_exts = READ_ONCE(slab->obj_exts);
1979	handle_failed_objexts_alloc(old_exts, vec, objects);
1980	if (new_slab) {
1981		/*
1982		 * If the slab is brand new and nobody can yet access its
1983		 * obj_exts, no synchronization is required and obj_exts can
1984		 * be simply assigned.
1985		 */
1986		slab->obj_exts = new_exts;
1987	} else if ((old_exts & ~OBJEXTS_FLAGS_MASK) ||
1988		   cmpxchg(&slab->obj_exts, old_exts, new_exts) != old_exts) {
1989		/*
1990		 * If the slab is already in use, somebody can allocate and
1991		 * assign slabobj_exts in parallel. In this case the existing
1992		 * objcg vector should be reused.
1993		 */
1994		mark_objexts_empty(vec);
1995		kfree(vec);
1996		return 0;
1997	}
1998
1999	kmemleak_not_leak(vec);
2000	return 0;
2001}
2002
2003static inline void free_slab_obj_exts(struct slab *slab)
2004{
2005	struct slabobj_ext *obj_exts;
2006
2007	obj_exts = slab_obj_exts(slab);
2008	if (!obj_exts)
2009		return;
2010
2011	/*
2012	 * obj_exts was created with __GFP_NO_OBJ_EXT flag, therefore its
2013	 * corresponding extension will be NULL. alloc_tag_sub() will throw a
2014	 * warning if slab has extensions but the extension of an object is
2015	 * NULL, therefore replace NULL with CODETAG_EMPTY to indicate that
2016	 * the extension for obj_exts is expected to be NULL.
2017	 */
2018	mark_objexts_empty(obj_exts);
2019	kfree(obj_exts);
2020	slab->obj_exts = 0;
2021}
2022
2023static inline bool need_slab_obj_ext(void)
2024{
2025	if (mem_alloc_profiling_enabled())
2026		return true;
2027
2028	/*
2029	 * CONFIG_MEMCG creates vector of obj_cgroup objects conditionally
2030	 * inside memcg_slab_post_alloc_hook. No other users for now.
2031	 */
2032	return false;
2033}
2034
2035#else /* CONFIG_SLAB_OBJ_EXT */
2036
2037static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
2038			       gfp_t gfp, bool new_slab)
2039{
2040	return 0;
2041}
2042
2043static inline void free_slab_obj_exts(struct slab *slab)
2044{
2045}
2046
2047static inline bool need_slab_obj_ext(void)
2048{
2049	return false;
2050}
2051
2052#endif /* CONFIG_SLAB_OBJ_EXT */
2053
2054#ifdef CONFIG_MEM_ALLOC_PROFILING
2055
2056static inline struct slabobj_ext *
2057prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p)
2058{
2059	struct slab *slab;
2060
2061	if (!p)
2062		return NULL;
2063
2064	if (s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE))
2065		return NULL;
2066
2067	if (flags & __GFP_NO_OBJ_EXT)
2068		return NULL;
2069
2070	slab = virt_to_slab(p);
2071	if (!slab_obj_exts(slab) &&
2072	    WARN(alloc_slab_obj_exts(slab, s, flags, false),
2073		 "%s, %s: Failed to create slab extension vector!\n",
2074		 __func__, s->name))
2075		return NULL;
2076
2077	return slab_obj_exts(slab) + obj_to_index(s, slab, p);
2078}
2079
2080static inline void
2081alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
2082{
2083	if (need_slab_obj_ext()) {
2084		struct slabobj_ext *obj_exts;
2085
2086		obj_exts = prepare_slab_obj_exts_hook(s, flags, object);
2087		/*
2088		 * Currently obj_exts is used only for allocation profiling.
2089		 * If other users appear then mem_alloc_profiling_enabled()
2090		 * check should be added before alloc_tag_add().
2091		 */
2092		if (likely(obj_exts))
2093			alloc_tag_add(&obj_exts->ref, current->alloc_tag, s->size);
2094	}
2095}
2096
2097static inline void
2098alloc_tagging_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p,
2099			     int objects)
2100{
2101	struct slabobj_ext *obj_exts;
2102	int i;
2103
2104	if (!mem_alloc_profiling_enabled())
2105		return;
2106
2107	/* slab->obj_exts might not be NULL if it was created for MEMCG accounting. */
2108	if (s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE))
2109		return;
2110
2111	obj_exts = slab_obj_exts(slab);
2112	if (!obj_exts)
2113		return;
2114
2115	for (i = 0; i < objects; i++) {
2116		unsigned int off = obj_to_index(s, slab, p[i]);
2117
2118		alloc_tag_sub(&obj_exts[off].ref, s->size);
2119	}
2120}
2121
2122#else /* CONFIG_MEM_ALLOC_PROFILING */
2123
2124static inline void
2125alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
2126{
2127}
2128
2129static inline void
2130alloc_tagging_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p,
2131			     int objects)
2132{
2133}
2134
2135#endif /* CONFIG_MEM_ALLOC_PROFILING */
2136
2137
2138#ifdef CONFIG_MEMCG
2139
2140static void memcg_alloc_abort_single(struct kmem_cache *s, void *object);
2141
2142static __fastpath_inline
2143bool memcg_slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
2144				gfp_t flags, size_t size, void **p)
2145{
2146	if (likely(!memcg_kmem_online()))
2147		return true;
2148
2149	if (likely(!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)))
2150		return true;
2151
2152	if (likely(__memcg_slab_post_alloc_hook(s, lru, flags, size, p)))
2153		return true;
2154
2155	if (likely(size == 1)) {
2156		memcg_alloc_abort_single(s, *p);
2157		*p = NULL;
2158	} else {
2159		kmem_cache_free_bulk(s, size, p);
2160	}
2161
2162	return false;
2163}
2164
2165static __fastpath_inline
2166void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p,
2167			  int objects)
2168{
2169	struct slabobj_ext *obj_exts;
2170
2171	if (!memcg_kmem_online())
2172		return;
2173
2174	obj_exts = slab_obj_exts(slab);
2175	if (likely(!obj_exts))
2176		return;
2177
2178	__memcg_slab_free_hook(s, slab, p, objects, obj_exts);
2179}
2180
2181static __fastpath_inline
2182bool memcg_slab_post_charge(void *p, gfp_t flags)
2183{
2184	struct slabobj_ext *slab_exts;
2185	struct kmem_cache *s;
2186	struct folio *folio;
2187	struct slab *slab;
2188	unsigned long off;
2189
2190	folio = virt_to_folio(p);
2191	if (!folio_test_slab(folio)) {
2192		int size;
2193
2194		if (folio_memcg_kmem(folio))
2195			return true;
2196
2197		if (__memcg_kmem_charge_page(folio_page(folio, 0), flags,
2198					     folio_order(folio)))
2199			return false;
2200
2201		/*
2202		 * This folio has already been accounted in the global stats but
2203		 * not in the memcg stats. So, subtract from the global and use
2204		 * the interface which adds to both global and memcg stats.
2205		 */
2206		size = folio_size(folio);
2207		node_stat_mod_folio(folio, NR_SLAB_UNRECLAIMABLE_B, -size);
2208		lruvec_stat_mod_folio(folio, NR_SLAB_UNRECLAIMABLE_B, size);
2209		return true;
2210	}
2211
2212	slab = folio_slab(folio);
2213	s = slab->slab_cache;
2214
2215	/*
2216	 * Ignore KMALLOC_NORMAL cache to avoid possible circular dependency
2217	 * of slab_obj_exts being allocated from the same slab and thus the slab
2218	 * becoming effectively unfreeable.
2219	 */
2220	if (is_kmalloc_normal(s))
2221		return true;
 
2222
2223	/* Ignore already charged objects. */
2224	slab_exts = slab_obj_exts(slab);
2225	if (slab_exts) {
2226		off = obj_to_index(s, slab, p);
2227		if (unlikely(slab_exts[off].objcg))
2228			return true;
2229	}
2230
2231	return __memcg_slab_post_alloc_hook(s, NULL, flags, 1, &p);
2232}
2233
2234#else /* CONFIG_MEMCG */
2235static inline bool memcg_slab_post_alloc_hook(struct kmem_cache *s,
2236					      struct list_lru *lru,
2237					      gfp_t flags, size_t size,
2238					      void **p)
2239{
2240	return true;
2241}
2242
2243static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
2244					void **p, int objects)
2245{
2246}
2247
2248static inline bool memcg_slab_post_charge(void *p, gfp_t flags)
2249{
2250	return true;
2251}
2252#endif /* CONFIG_MEMCG */
2253
2254#ifdef CONFIG_SLUB_RCU_DEBUG
2255static void slab_free_after_rcu_debug(struct rcu_head *rcu_head);
2256
2257struct rcu_delayed_free {
2258	struct rcu_head head;
2259	void *object;
2260};
2261#endif
2262
2263/*
2264 * Hooks for other subsystems that check memory allocations. In a typical
2265 * production configuration these hooks all should produce no code at all.
2266 *
2267 * Returns true if freeing of the object can proceed, false if its reuse
2268 * was delayed by CONFIG_SLUB_RCU_DEBUG or KASAN quarantine, or it was returned
2269 * to KFENCE.
2270 */
2271static __always_inline
2272bool slab_free_hook(struct kmem_cache *s, void *x, bool init,
2273		    bool after_rcu_delay)
2274{
2275	/* Are the object contents still accessible? */
2276	bool still_accessible = (s->flags & SLAB_TYPESAFE_BY_RCU) && !after_rcu_delay;
2277
2278	kmemleak_free_recursive(x, s->flags);
2279	kmsan_slab_free(s, x);
2280
2281	debug_check_no_locks_freed(x, s->object_size);
2282
2283	if (!(s->flags & SLAB_DEBUG_OBJECTS))
2284		debug_check_no_obj_freed(x, s->object_size);
2285
2286	/* Use KCSAN to help debug racy use-after-free. */
2287	if (!still_accessible)
2288		__kcsan_check_access(x, s->object_size,
2289				     KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT);
2290
2291	if (kfence_free(x))
2292		return false;
2293
2294	/*
2295	 * Give KASAN a chance to notice an invalid free operation before we
2296	 * modify the object.
2297	 */
2298	if (kasan_slab_pre_free(s, x))
2299		return false;
2300
2301#ifdef CONFIG_SLUB_RCU_DEBUG
2302	if (still_accessible) {
2303		struct rcu_delayed_free *delayed_free;
2304
2305		delayed_free = kmalloc(sizeof(*delayed_free), GFP_NOWAIT);
2306		if (delayed_free) {
2307			/*
2308			 * Let KASAN track our call stack as a "related work
2309			 * creation", just like if the object had been freed
2310			 * normally via kfree_rcu().
2311			 * We have to do this manually because the rcu_head is
2312			 * not located inside the object.
2313			 */
2314			kasan_record_aux_stack_noalloc(x);
2315
2316			delayed_free->object = x;
2317			call_rcu(&delayed_free->head, slab_free_after_rcu_debug);
2318			return false;
2319		}
2320	}
2321#endif /* CONFIG_SLUB_RCU_DEBUG */
2322
2323	/*
2324	 * As memory initialization might be integrated into KASAN,
2325	 * kasan_slab_free and initialization memset's must be
2326	 * kept together to avoid discrepancies in behavior.
2327	 *
2328	 * The initialization memset's clear the object and the metadata,
2329	 * but don't touch the SLAB redzone.
2330	 *
2331	 * The object's freepointer is also avoided if stored outside the
2332	 * object.
2333	 */
2334	if (unlikely(init)) {
2335		int rsize;
2336		unsigned int inuse, orig_size;
2337
2338		inuse = get_info_end(s);
2339		orig_size = get_orig_size(s, x);
2340		if (!kasan_has_integrated_init())
2341			memset(kasan_reset_tag(x), 0, orig_size);
2342		rsize = (s->flags & SLAB_RED_ZONE) ? s->red_left_pad : 0;
2343		memset((char *)kasan_reset_tag(x) + inuse, 0,
2344		       s->size - inuse - rsize);
2345		/*
2346		 * Restore orig_size, otherwize kmalloc redzone overwritten
2347		 * would be reported
2348		 */
2349		set_orig_size(s, x, orig_size);
2350
2351	}
2352	/* KASAN might put x into memory quarantine, delaying its reuse. */
2353	return !kasan_slab_free(s, x, init, still_accessible);
2354}
2355
2356static __fastpath_inline
2357bool slab_free_freelist_hook(struct kmem_cache *s, void **head, void **tail,
2358			     int *cnt)
2359{
 
 
 
 
 
 
 
 
 
2360
2361	void *object;
2362	void *next = *head;
2363	void *old_tail = *tail;
2364	bool init;
2365
2366	if (is_kfence_address(next)) {
2367		slab_free_hook(s, next, false, false);
2368		return false;
2369	}
2370
2371	/* Head and tail of the reconstructed freelist */
2372	*head = NULL;
2373	*tail = NULL;
2374
2375	init = slab_want_init_on_free(s);
2376
2377	do {
2378		object = next;
2379		next = get_freepointer(s, object);
2380
2381		/* If object's reuse doesn't have to be delayed */
2382		if (likely(slab_free_hook(s, object, init, false))) {
2383			/* Move object to the new freelist */
2384			set_freepointer(s, object, *head);
2385			*head = object;
2386			if (!*tail)
2387				*tail = object;
2388		} else {
2389			/*
2390			 * Adjust the reconstructed freelist depth
2391			 * accordingly if object's reuse is delayed.
2392			 */
2393			--(*cnt);
2394		}
2395	} while (object != old_tail);
2396
2397	return *head != NULL;
2398}
2399
2400static void *setup_object(struct kmem_cache *s, void *object)
 
2401{
2402	setup_object_debug(s, object);
2403	object = kasan_init_slab_obj(s, object);
2404	if (unlikely(s->ctor)) {
2405		kasan_unpoison_new_object(s, object);
2406		s->ctor(object);
2407		kasan_poison_new_object(s, object);
2408	}
2409	return object;
2410}
2411
2412/*
2413 * Slab allocation and freeing
2414 */
2415static inline struct slab *alloc_slab_page(gfp_t flags, int node,
2416		struct kmem_cache_order_objects oo)
2417{
2418	struct folio *folio;
2419	struct slab *slab;
2420	unsigned int order = oo_order(oo);
 
2421
2422	if (node == NUMA_NO_NODE)
2423		folio = (struct folio *)alloc_pages(flags, order);
2424	else
2425		folio = (struct folio *)__alloc_pages_node(node, flags, order);
2426
2427	if (!folio)
2428		return NULL;
2429
2430	slab = folio_slab(folio);
2431	__folio_set_slab(folio);
2432	/* Make the flag visible before any changes to folio->mapping */
2433	smp_wmb();
2434	if (folio_is_pfmemalloc(folio))
2435		slab_set_pfmemalloc(slab);
2436
2437	return slab;
2438}
2439
2440#ifdef CONFIG_SLAB_FREELIST_RANDOM
2441/* Pre-initialize the random sequence cache */
2442static int init_cache_random_seq(struct kmem_cache *s)
2443{
2444	unsigned int count = oo_objects(s->oo);
2445	int err;
2446
2447	/* Bailout if already initialised */
2448	if (s->random_seq)
2449		return 0;
2450
2451	err = cache_random_seq_create(s, count, GFP_KERNEL);
2452	if (err) {
2453		pr_err("SLUB: Unable to initialize free list for %s\n",
2454			s->name);
2455		return err;
2456	}
2457
2458	/* Transform to an offset on the set of pages */
2459	if (s->random_seq) {
2460		unsigned int i;
2461
2462		for (i = 0; i < count; i++)
2463			s->random_seq[i] *= s->size;
2464	}
2465	return 0;
2466}
2467
2468/* Initialize each random sequence freelist per cache */
2469static void __init init_freelist_randomization(void)
2470{
2471	struct kmem_cache *s;
2472
2473	mutex_lock(&slab_mutex);
2474
2475	list_for_each_entry(s, &slab_caches, list)
2476		init_cache_random_seq(s);
2477
2478	mutex_unlock(&slab_mutex);
2479}
2480
2481/* Get the next entry on the pre-computed freelist randomized */
2482static void *next_freelist_entry(struct kmem_cache *s,
2483				unsigned long *pos, void *start,
2484				unsigned long page_limit,
2485				unsigned long freelist_count)
2486{
2487	unsigned int idx;
2488
2489	/*
2490	 * If the target page allocation failed, the number of objects on the
2491	 * page might be smaller than the usual size defined by the cache.
2492	 */
2493	do {
2494		idx = s->random_seq[*pos];
2495		*pos += 1;
2496		if (*pos >= freelist_count)
2497			*pos = 0;
2498	} while (unlikely(idx >= page_limit));
2499
2500	return (char *)start + idx;
2501}
2502
2503/* Shuffle the single linked freelist based on a random pre-computed sequence */
2504static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
2505{
2506	void *start;
2507	void *cur;
2508	void *next;
2509	unsigned long idx, pos, page_limit, freelist_count;
2510
2511	if (slab->objects < 2 || !s->random_seq)
2512		return false;
2513
2514	freelist_count = oo_objects(s->oo);
2515	pos = get_random_u32_below(freelist_count);
2516
2517	page_limit = slab->objects * s->size;
2518	start = fixup_red_left(s, slab_address(slab));
2519
2520	/* First entry is used as the base of the freelist */
2521	cur = next_freelist_entry(s, &pos, start, page_limit, freelist_count);
2522	cur = setup_object(s, cur);
2523	slab->freelist = cur;
2524
2525	for (idx = 1; idx < slab->objects; idx++) {
2526		next = next_freelist_entry(s, &pos, start, page_limit,
2527			freelist_count);
2528		next = setup_object(s, next);
2529		set_freepointer(s, cur, next);
2530		cur = next;
2531	}
2532	set_freepointer(s, cur, NULL);
2533
2534	return true;
2535}
2536#else
2537static inline int init_cache_random_seq(struct kmem_cache *s)
2538{
2539	return 0;
2540}
2541static inline void init_freelist_randomization(void) { }
2542static inline bool shuffle_freelist(struct kmem_cache *s, struct slab *slab)
2543{
2544	return false;
2545}
2546#endif /* CONFIG_SLAB_FREELIST_RANDOM */
2547
2548static __always_inline void account_slab(struct slab *slab, int order,
2549					 struct kmem_cache *s, gfp_t gfp)
2550{
2551	if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT))
2552		alloc_slab_obj_exts(slab, s, gfp, true);
2553
2554	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
2555			    PAGE_SIZE << order);
2556}
2557
2558static __always_inline void unaccount_slab(struct slab *slab, int order,
2559					   struct kmem_cache *s)
2560{
2561	if (memcg_kmem_online() || need_slab_obj_ext())
2562		free_slab_obj_exts(slab);
2563
2564	mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
2565			    -(PAGE_SIZE << order));
2566}
2567
2568static struct slab *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
2569{
2570	struct slab *slab;
2571	struct kmem_cache_order_objects oo = s->oo;
2572	gfp_t alloc_gfp;
2573	void *start, *p, *next;
2574	int idx;
2575	bool shuffle;
2576
2577	flags &= gfp_allowed_mask;
2578
 
 
 
2579	flags |= s->allocflags;
2580
2581	/*
2582	 * Let the initial higher-order allocation fail under memory pressure
2583	 * so we fall-back to the minimum order allocation.
2584	 */
2585	alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
2586	if ((alloc_gfp & __GFP_DIRECT_RECLAIM) && oo_order(oo) > oo_order(s->min))
2587		alloc_gfp = (alloc_gfp | __GFP_NOMEMALLOC) & ~__GFP_RECLAIM;
2588
2589	slab = alloc_slab_page(alloc_gfp, node, oo);
2590	if (unlikely(!slab)) {
2591		oo = s->min;
2592		alloc_gfp = flags;
2593		/*
2594		 * Allocation may have failed due to fragmentation.
2595		 * Try a lower order alloc if possible
2596		 */
2597		slab = alloc_slab_page(alloc_gfp, node, oo);
2598		if (unlikely(!slab))
2599			return NULL;
2600		stat(s, ORDER_FALLBACK);
2601	}
2602
2603	slab->objects = oo_objects(oo);
2604	slab->inuse = 0;
2605	slab->frozen = 0;
2606
2607	account_slab(slab, oo_order(oo), s, flags);
2608
2609	slab->slab_cache = s;
 
 
 
 
 
 
 
 
2610
2611	kasan_poison_slab(slab);
2612
2613	start = slab_address(slab);
 
 
 
 
2614
2615	setup_slab_debug(s, slab, start);
2616
2617	shuffle = shuffle_freelist(s, slab);
 
2618
2619	if (!shuffle) {
2620		start = fixup_red_left(s, start);
2621		start = setup_object(s, start);
2622		slab->freelist = start;
2623		for (idx = 0, p = start; idx < slab->objects - 1; idx++) {
2624			next = p + s->size;
2625			next = setup_object(s, next);
2626			set_freepointer(s, p, next);
2627			p = next;
2628		}
2629		set_freepointer(s, p, NULL);
2630	}
2631
2632	return slab;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2633}
2634
2635static struct slab *new_slab(struct kmem_cache *s, gfp_t flags, int node)
2636{
2637	if (unlikely(flags & GFP_SLAB_BUG_MASK))
2638		flags = kmalloc_fix_flags(flags);
2639
2640	WARN_ON_ONCE(s->ctor && (flags & __GFP_ZERO));
2641
2642	return allocate_slab(s,
2643		flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
2644}
2645
2646static void __free_slab(struct kmem_cache *s, struct slab *slab)
2647{
2648	struct folio *folio = slab_folio(slab);
2649	int order = folio_order(folio);
2650	int pages = 1 << order;
2651
2652	__slab_clear_pfmemalloc(slab);
2653	folio->mapping = NULL;
2654	/* Make the mapping reset visible before clearing the flag */
2655	smp_wmb();
2656	__folio_clear_slab(folio);
2657	mm_account_reclaimed_pages(pages);
2658	unaccount_slab(slab, order, s);
2659	__free_pages(&folio->page, order);
2660}
2661
2662static void rcu_free_slab(struct rcu_head *h)
2663{
2664	struct slab *slab = container_of(h, struct slab, rcu_head);
 
 
2665
2666	__free_slab(slab->slab_cache, slab);
2667}
2668
2669static void free_slab(struct kmem_cache *s, struct slab *slab)
2670{
2671	if (kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) {
2672		void *p;
2673
2674		slab_pad_check(s, slab);
2675		for_each_object(p, s, slab_address(slab), slab->objects)
2676			check_object(s, slab, p, SLUB_RED_INACTIVE);
2677	}
2678
2679	if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU))
2680		call_rcu(&slab->rcu_head, rcu_free_slab);
2681	else
2682		__free_slab(s, slab);
 
2683}
2684
2685static void discard_slab(struct kmem_cache *s, struct slab *slab)
2686{
2687	dec_slabs_node(s, slab_nid(slab), slab->objects);
2688	free_slab(s, slab);
2689}
2690
2691/*
2692 * SLUB reuses PG_workingset bit to keep track of whether it's on
2693 * the per-node partial list.
2694 */
2695static inline bool slab_test_node_partial(const struct slab *slab)
2696{
2697	return folio_test_workingset(slab_folio(slab));
 
 
 
 
 
 
 
2698}
2699
2700static inline void slab_set_node_partial(struct slab *slab)
2701{
2702	set_bit(PG_workingset, folio_flags(slab_folio(slab), 0));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2703}
2704
2705static inline void slab_clear_node_partial(struct slab *slab)
2706{
2707	clear_bit(PG_workingset, folio_flags(slab_folio(slab), 0));
 
2708}
2709
2710/*
2711 * Management of partially allocated slabs.
2712 */
2713static inline void
2714__add_partial(struct kmem_cache_node *n, struct slab *slab, int tail)
2715{
2716	n->nr_partial++;
2717	if (tail == DEACTIVATE_TO_TAIL)
2718		list_add_tail(&slab->slab_list, &n->partial);
2719	else
2720		list_add(&slab->slab_list, &n->partial);
2721	slab_set_node_partial(slab);
2722}
2723
2724static inline void add_partial(struct kmem_cache_node *n,
2725				struct slab *slab, int tail)
2726{
2727	lockdep_assert_held(&n->list_lock);
2728	__add_partial(n, slab, tail);
2729}
2730
2731static inline void remove_partial(struct kmem_cache_node *n,
2732					struct slab *slab)
2733{
2734	lockdep_assert_held(&n->list_lock);
2735	list_del(&slab->slab_list);
2736	slab_clear_node_partial(slab);
2737	n->nr_partial--;
2738}
2739
2740/*
2741 * Called only for kmem_cache_debug() caches instead of remove_partial(), with a
2742 * slab from the n->partial list. Remove only a single object from the slab, do
2743 * the alloc_debug_processing() checks and leave the slab on the list, or move
2744 * it to full list if it was the last free object.
2745 */
2746static void *alloc_single_from_partial(struct kmem_cache *s,
2747		struct kmem_cache_node *n, struct slab *slab, int orig_size)
 
2748{
2749	void *object;
 
 
2750
2751	lockdep_assert_held(&n->list_lock);
2752
2753	object = slab->freelist;
2754	slab->freelist = get_freepointer(s, object);
2755	slab->inuse++;
2756
2757	if (!alloc_debug_processing(s, slab, object, orig_size)) {
2758		if (folio_test_slab(slab_folio(slab)))
2759			remove_partial(n, slab);
2760		return NULL;
2761	}
2762
2763	if (slab->inuse == slab->objects) {
2764		remove_partial(n, slab);
2765		add_full(s, n, slab);
 
2766	}
2767
2768	return object;
2769}
2770
2771/*
2772 * Called only for kmem_cache_debug() caches to allocate from a freshly
2773 * allocated slab. Allocate a single object instead of whole freelist
2774 * and put the slab to the partial (or full) list.
2775 */
2776static void *alloc_single_from_new_slab(struct kmem_cache *s,
2777					struct slab *slab, int orig_size)
2778{
2779	int nid = slab_nid(slab);
2780	struct kmem_cache_node *n = get_node(s, nid);
2781	unsigned long flags;
2782	void *object;
2783
2784
2785	object = slab->freelist;
2786	slab->freelist = get_freepointer(s, object);
2787	slab->inuse = 1;
2788
2789	if (!alloc_debug_processing(s, slab, object, orig_size))
2790		/*
2791		 * It's not really expected that this would fail on a
2792		 * freshly allocated slab, but a concurrent memory
2793		 * corruption in theory could cause that.
2794		 */
2795		return NULL;
2796
2797	spin_lock_irqsave(&n->list_lock, flags);
2798
2799	if (slab->inuse == slab->objects)
2800		add_full(s, n, slab);
2801	else
2802		add_partial(n, slab, DEACTIVATE_TO_HEAD);
2803
2804	inc_slabs_node(s, nid, slab->objects);
2805	spin_unlock_irqrestore(&n->list_lock, flags);
2806
2807	return object;
2808}
2809
2810#ifdef CONFIG_SLUB_CPU_PARTIAL
2811static void put_cpu_partial(struct kmem_cache *s, struct slab *slab, int drain);
2812#else
2813static inline void put_cpu_partial(struct kmem_cache *s, struct slab *slab,
2814				   int drain) { }
2815#endif
2816static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags);
2817
2818/*
2819 * Try to allocate a partial slab from a specific node.
2820 */
2821static struct slab *get_partial_node(struct kmem_cache *s,
2822				     struct kmem_cache_node *n,
2823				     struct partial_context *pc)
2824{
2825	struct slab *slab, *slab2, *partial = NULL;
2826	unsigned long flags;
2827	unsigned int partial_slabs = 0;
 
2828
2829	/*
2830	 * Racy check. If we mistakenly see no partial slabs then we
2831	 * just allocate an empty slab. If we mistakenly try to get a
2832	 * partial slab and there is none available then get_partial()
2833	 * will return NULL.
2834	 */
2835	if (!n || !n->nr_partial)
2836		return NULL;
2837
2838	spin_lock_irqsave(&n->list_lock, flags);
2839	list_for_each_entry_safe(slab, slab2, &n->partial, slab_list) {
2840		if (!pfmemalloc_match(slab, pc->flags))
2841			continue;
2842
2843		if (IS_ENABLED(CONFIG_SLUB_TINY) || kmem_cache_debug(s)) {
2844			void *object = alloc_single_from_partial(s, n, slab,
2845							pc->orig_size);
2846			if (object) {
2847				partial = slab;
2848				pc->object = object;
2849				break;
2850			}
2851			continue;
2852		}
2853
2854		remove_partial(n, slab);
 
 
2855
2856		if (!partial) {
2857			partial = slab;
 
2858			stat(s, ALLOC_FROM_PARTIAL);
2859
2860			if ((slub_get_cpu_partial(s) == 0)) {
2861				break;
2862			}
2863		} else {
2864			put_cpu_partial(s, slab, 0);
2865			stat(s, CPU_PARTIAL_NODE);
2866
2867			if (++partial_slabs > slub_get_cpu_partial(s) / 2) {
2868				break;
2869			}
2870		}
 
 
 
 
2871	}
2872	spin_unlock_irqrestore(&n->list_lock, flags);
2873	return partial;
2874}
2875
2876/*
2877 * Get a slab from somewhere. Search in increasing NUMA distances.
2878 */
2879static struct slab *get_any_partial(struct kmem_cache *s,
2880				    struct partial_context *pc)
2881{
2882#ifdef CONFIG_NUMA
2883	struct zonelist *zonelist;
2884	struct zoneref *z;
2885	struct zone *zone;
2886	enum zone_type highest_zoneidx = gfp_zone(pc->flags);
2887	struct slab *slab;
2888	unsigned int cpuset_mems_cookie;
2889
2890	/*
2891	 * The defrag ratio allows a configuration of the tradeoffs between
2892	 * inter node defragmentation and node local allocations. A lower
2893	 * defrag_ratio increases the tendency to do local allocations
2894	 * instead of attempting to obtain partial slabs from other nodes.
2895	 *
2896	 * If the defrag_ratio is set to 0 then kmalloc() always
2897	 * returns node local objects. If the ratio is higher then kmalloc()
2898	 * may return off node objects because partial slabs are obtained
2899	 * from other nodes and filled up.
2900	 *
2901	 * If /sys/kernel/slab/xx/remote_node_defrag_ratio is set to 100
2902	 * (which makes defrag_ratio = 1000) then every (well almost)
2903	 * allocation will first attempt to defrag slab caches on other nodes.
2904	 * This means scanning over all nodes to look for partial slabs which
2905	 * may be expensive if we do it every time we are trying to find a slab
2906	 * with available objects.
2907	 */
2908	if (!s->remote_node_defrag_ratio ||
2909			get_cycles() % 1024 > s->remote_node_defrag_ratio)
2910		return NULL;
2911
2912	do {
2913		cpuset_mems_cookie = read_mems_allowed_begin();
2914		zonelist = node_zonelist(mempolicy_slab_node(), pc->flags);
2915		for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
2916			struct kmem_cache_node *n;
2917
2918			n = get_node(s, zone_to_nid(zone));
2919
2920			if (n && cpuset_zone_allowed(zone, pc->flags) &&
2921					n->nr_partial > s->min_partial) {
2922				slab = get_partial_node(s, n, pc);
2923				if (slab) {
2924					/*
2925					 * Don't check read_mems_allowed_retry()
2926					 * here - if mems_allowed was updated in
2927					 * parallel, that was a harmless race
2928					 * between allocation and the cpuset
2929					 * update
2930					 */
2931					return slab;
2932				}
2933			}
2934		}
2935	} while (read_mems_allowed_retry(cpuset_mems_cookie));
2936#endif	/* CONFIG_NUMA */
2937	return NULL;
2938}
2939
2940/*
2941 * Get a partial slab, lock it and return it.
2942 */
2943static struct slab *get_partial(struct kmem_cache *s, int node,
2944				struct partial_context *pc)
2945{
2946	struct slab *slab;
2947	int searchnode = node;
2948
2949	if (node == NUMA_NO_NODE)
2950		searchnode = numa_mem_id();
 
 
2951
2952	slab = get_partial_node(s, get_node(s, searchnode), pc);
2953	if (slab || (node != NUMA_NO_NODE && (pc->flags & __GFP_THISNODE)))
2954		return slab;
2955
2956	return get_any_partial(s, pc);
2957}
2958
2959#ifndef CONFIG_SLUB_TINY
2960
2961#ifdef CONFIG_PREEMPTION
2962/*
2963 * Calculate the next globally unique transaction for disambiguation
2964 * during cmpxchg. The transactions start with the cpu number and are then
2965 * incremented by CONFIG_NR_CPUS.
2966 */
2967#define TID_STEP  roundup_pow_of_two(CONFIG_NR_CPUS)
2968#else
2969/*
2970 * No preemption supported therefore also no need to check for
2971 * different cpus.
2972 */
2973#define TID_STEP 1
2974#endif /* CONFIG_PREEMPTION */
2975
2976static inline unsigned long next_tid(unsigned long tid)
2977{
2978	return tid + TID_STEP;
2979}
2980
2981#ifdef SLUB_DEBUG_CMPXCHG
2982static inline unsigned int tid_to_cpu(unsigned long tid)
2983{
2984	return tid % TID_STEP;
2985}
2986
2987static inline unsigned long tid_to_event(unsigned long tid)
2988{
2989	return tid / TID_STEP;
2990}
2991#endif
2992
2993static inline unsigned int init_tid(int cpu)
2994{
2995	return cpu;
2996}
2997
2998static inline void note_cmpxchg_failure(const char *n,
2999		const struct kmem_cache *s, unsigned long tid)
3000{
3001#ifdef SLUB_DEBUG_CMPXCHG
3002	unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
3003
3004	pr_info("%s %s: cmpxchg redo ", n, s->name);
3005
3006#ifdef CONFIG_PREEMPTION
3007	if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
3008		pr_warn("due to cpu change %d -> %d\n",
3009			tid_to_cpu(tid), tid_to_cpu(actual_tid));
3010	else
3011#endif
3012	if (tid_to_event(tid) != tid_to_event(actual_tid))
3013		pr_warn("due to cpu running other code. Event %ld->%ld\n",
3014			tid_to_event(tid), tid_to_event(actual_tid));
3015	else
3016		pr_warn("for unknown reason: actual=%lx was=%lx target=%lx\n",
3017			actual_tid, tid, next_tid(tid));
3018#endif
3019	stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
3020}
3021
3022static void init_kmem_cache_cpus(struct kmem_cache *s)
3023{
3024	int cpu;
3025	struct kmem_cache_cpu *c;
3026
3027	for_each_possible_cpu(cpu) {
3028		c = per_cpu_ptr(s->cpu_slab, cpu);
3029		local_lock_init(&c->lock);
3030		c->tid = init_tid(cpu);
3031	}
3032}
3033
3034/*
3035 * Finishes removing the cpu slab. Merges cpu's freelist with slab's freelist,
3036 * unfreezes the slabs and puts it on the proper list.
3037 * Assumes the slab has been already safely taken away from kmem_cache_cpu
3038 * by the caller.
3039 */
3040static void deactivate_slab(struct kmem_cache *s, struct slab *slab,
3041			    void *freelist)
3042{
3043	struct kmem_cache_node *n = get_node(s, slab_nid(slab));
3044	int free_delta = 0;
3045	void *nextfree, *freelist_iter, *freelist_tail;
 
 
3046	int tail = DEACTIVATE_TO_HEAD;
3047	unsigned long flags = 0;
3048	struct slab new;
3049	struct slab old;
3050
3051	if (READ_ONCE(slab->freelist)) {
3052		stat(s, DEACTIVATE_REMOTE_FREES);
3053		tail = DEACTIVATE_TO_TAIL;
3054	}
3055
3056	/*
3057	 * Stage one: Count the objects on cpu's freelist as free_delta and
3058	 * remember the last object in freelist_tail for later splicing.
 
 
 
 
3059	 */
3060	freelist_tail = NULL;
3061	freelist_iter = freelist;
3062	while (freelist_iter) {
3063		nextfree = get_freepointer(s, freelist_iter);
3064
3065		/*
3066		 * If 'nextfree' is invalid, it is possible that the object at
3067		 * 'freelist_iter' is already corrupted.  So isolate all objects
3068		 * starting at 'freelist_iter' by skipping them.
3069		 */
3070		if (freelist_corrupted(s, slab, &freelist_iter, nextfree))
3071			break;
3072
3073		freelist_tail = freelist_iter;
3074		free_delta++;
 
 
3075
3076		freelist_iter = nextfree;
3077	}
3078
3079	/*
3080	 * Stage two: Unfreeze the slab while splicing the per-cpu
3081	 * freelist to the head of slab's freelist.
 
 
 
 
 
 
 
 
 
 
3082	 */
3083	do {
3084		old.freelist = READ_ONCE(slab->freelist);
3085		old.counters = READ_ONCE(slab->counters);
3086		VM_BUG_ON(!old.frozen);
3087
3088		/* Determine target state of the slab */
3089		new.counters = old.counters;
3090		new.frozen = 0;
3091		if (freelist_tail) {
3092			new.inuse -= free_delta;
3093			set_freepointer(s, freelist_tail, old.freelist);
3094			new.freelist = freelist;
3095		} else {
3096			new.freelist = old.freelist;
3097		}
3098	} while (!slab_update_freelist(s, slab,
3099		old.freelist, old.counters,
3100		new.freelist, new.counters,
3101		"unfreezing slab"));
3102
3103	/*
3104	 * Stage three: Manipulate the slab list based on the updated state.
3105	 */
3106	if (!new.inuse && n->nr_partial >= s->min_partial) {
3107		stat(s, DEACTIVATE_EMPTY);
3108		discard_slab(s, slab);
3109		stat(s, FREE_SLAB);
3110	} else if (new.freelist) {
3111		spin_lock_irqsave(&n->list_lock, flags);
3112		add_partial(n, slab, tail);
3113		spin_unlock_irqrestore(&n->list_lock, flags);
3114		stat(s, tail);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3115	} else {
3116		stat(s, DEACTIVATE_FULL);
 
 
 
 
 
 
 
 
 
3117	}
3118}
3119
3120#ifdef CONFIG_SLUB_CPU_PARTIAL
3121static void __put_partials(struct kmem_cache *s, struct slab *partial_slab)
3122{
3123	struct kmem_cache_node *n = NULL, *n2 = NULL;
3124	struct slab *slab, *slab_to_discard = NULL;
3125	unsigned long flags = 0;
3126
3127	while (partial_slab) {
3128		slab = partial_slab;
3129		partial_slab = slab->next;
3130
3131		n2 = get_node(s, slab_nid(slab));
3132		if (n != n2) {
3133			if (n)
3134				spin_unlock_irqrestore(&n->list_lock, flags);
3135
3136			n = n2;
3137			spin_lock_irqsave(&n->list_lock, flags);
3138		}
 
 
 
 
 
 
 
 
 
 
3139
3140		if (unlikely(!slab->inuse && n->nr_partial >= s->min_partial)) {
3141			slab->next = slab_to_discard;
3142			slab_to_discard = slab;
3143		} else {
3144			add_partial(n, slab, DEACTIVATE_TO_TAIL);
3145			stat(s, FREE_ADD_PARTIAL);
3146		}
3147	}
3148
3149	if (n)
3150		spin_unlock_irqrestore(&n->list_lock, flags);
 
 
 
 
3151
3152	while (slab_to_discard) {
3153		slab = slab_to_discard;
3154		slab_to_discard = slab_to_discard->next;
3155
 
3156		stat(s, DEACTIVATE_EMPTY);
3157		discard_slab(s, slab);
3158		stat(s, FREE_SLAB);
3159	}
3160}
3161
3162/*
3163 * Put all the cpu partial slabs to the node partial list.
 
 
 
 
3164 */
3165static void put_partials(struct kmem_cache *s)
 
3166{
3167	struct slab *partial_slab;
3168	unsigned long flags;
 
3169
3170	local_lock_irqsave(&s->cpu_slab->lock, flags);
3171	partial_slab = this_cpu_read(s->cpu_slab->partial);
3172	this_cpu_write(s->cpu_slab->partial, NULL);
3173	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3174
3175	if (partial_slab)
3176		__put_partials(s, partial_slab);
3177}
3178
3179static void put_partials_cpu(struct kmem_cache *s,
3180			     struct kmem_cache_cpu *c)
3181{
3182	struct slab *partial_slab;
3183
3184	partial_slab = slub_percpu_partial(c);
3185	c->partial = NULL;
 
3186
3187	if (partial_slab)
3188		__put_partials(s, partial_slab);
3189}
3190
3191/*
3192 * Put a slab into a partial slab slot if available.
3193 *
3194 * If we did not find a slot then simply move all the partials to the
3195 * per node partial list.
3196 */
3197static void put_cpu_partial(struct kmem_cache *s, struct slab *slab, int drain)
3198{
3199	struct slab *oldslab;
3200	struct slab *slab_to_put = NULL;
3201	unsigned long flags;
3202	int slabs = 0;
3203
3204	local_lock_irqsave(&s->cpu_slab->lock, flags);
 
3205
3206	oldslab = this_cpu_read(s->cpu_slab->partial);
3207
3208	if (oldslab) {
3209		if (drain && oldslab->slabs >= s->cpu_partial_slabs) {
3210			/*
3211			 * Partial array is full. Move the existing set to the
3212			 * per node partial list. Postpone the actual unfreezing
3213			 * outside of the critical section.
3214			 */
3215			slab_to_put = oldslab;
3216			oldslab = NULL;
3217		} else {
3218			slabs = oldslab->slabs;
 
3219		}
3220	}
3221
3222	slabs++;
3223
3224	slab->slabs = slabs;
3225	slab->next = oldslab;
3226
3227	this_cpu_write(s->cpu_slab->partial, slab);
3228
3229	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
 
 
3230
3231	if (slab_to_put) {
3232		__put_partials(s, slab_to_put);
3233		stat(s, CPU_PARTIAL_DRAIN);
3234	}
 
3235}
3236
3237#else	/* CONFIG_SLUB_CPU_PARTIAL */
3238
3239static inline void put_partials(struct kmem_cache *s) { }
3240static inline void put_partials_cpu(struct kmem_cache *s,
3241				    struct kmem_cache_cpu *c) { }
3242
3243#endif	/* CONFIG_SLUB_CPU_PARTIAL */
3244
3245static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 
3246{
3247	unsigned long flags;
3248	struct slab *slab;
3249	void *freelist;
3250
3251	local_lock_irqsave(&s->cpu_slab->lock, flags);
3252
3253	slab = c->slab;
3254	freelist = c->freelist;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3255
3256	c->slab = NULL;
3257	c->freelist = NULL;
3258	c->tid = next_tid(c->tid);
3259
3260	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
 
 
 
 
 
 
 
3261
3262	if (slab) {
3263		deactivate_slab(s, slab, freelist);
3264		stat(s, CPUSLAB_FLUSH);
3265	}
 
 
3266}
3267
3268static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
3269{
3270	struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
3271	void *freelist = c->freelist;
3272	struct slab *slab = c->slab;
3273
3274	c->slab = NULL;
3275	c->freelist = NULL;
3276	c->tid = next_tid(c->tid);
3277
3278	if (slab) {
3279		deactivate_slab(s, slab, freelist);
3280		stat(s, CPUSLAB_FLUSH);
3281	}
3282
3283	put_partials_cpu(s, c);
3284}
3285
3286struct slub_flush_work {
3287	struct work_struct work;
3288	struct kmem_cache *s;
3289	bool skip;
3290};
3291
3292/*
3293 * Flush cpu slab.
3294 *
3295 * Called from CPU work handler with migration disabled.
3296 */
3297static void flush_cpu_slab(struct work_struct *w)
3298{
3299	struct kmem_cache *s;
3300	struct kmem_cache_cpu *c;
3301	struct slub_flush_work *sfw;
3302
3303	sfw = container_of(w, struct slub_flush_work, work);
3304
3305	s = sfw->s;
3306	c = this_cpu_ptr(s->cpu_slab);
3307
3308	if (c->slab)
3309		flush_slab(s, c);
 
3310
3311	put_partials(s);
 
3312}
3313
3314static bool has_cpu_slab(int cpu, struct kmem_cache *s)
3315{
3316	struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
3317
3318	return c->slab || slub_percpu_partial(c);
3319}
3320
3321static DEFINE_MUTEX(flush_lock);
3322static DEFINE_PER_CPU(struct slub_flush_work, slub_flush);
3323
3324static void flush_all_cpus_locked(struct kmem_cache *s)
3325{
3326	struct slub_flush_work *sfw;
3327	unsigned int cpu;
3328
3329	lockdep_assert_cpus_held();
3330	mutex_lock(&flush_lock);
3331
3332	for_each_online_cpu(cpu) {
3333		sfw = &per_cpu(slub_flush, cpu);
3334		if (!has_cpu_slab(cpu, s)) {
3335			sfw->skip = true;
3336			continue;
3337		}
3338		INIT_WORK(&sfw->work, flush_cpu_slab);
3339		sfw->skip = false;
3340		sfw->s = s;
3341		queue_work_on(cpu, flushwq, &sfw->work);
3342	}
3343
3344	for_each_online_cpu(cpu) {
3345		sfw = &per_cpu(slub_flush, cpu);
3346		if (sfw->skip)
3347			continue;
3348		flush_work(&sfw->work);
3349	}
3350
3351	mutex_unlock(&flush_lock);
3352}
3353
3354static void flush_all(struct kmem_cache *s)
3355{
3356	cpus_read_lock();
3357	flush_all_cpus_locked(s);
3358	cpus_read_unlock();
3359}
3360
3361/*
3362 * Use the cpu notifier to insure that the cpu slabs are flushed when
3363 * necessary.
3364 */
3365static int slub_cpu_dead(unsigned int cpu)
3366{
3367	struct kmem_cache *s;
3368
3369	mutex_lock(&slab_mutex);
3370	list_for_each_entry(s, &slab_caches, list)
3371		__flush_cpu_slab(s, cpu);
3372	mutex_unlock(&slab_mutex);
3373	return 0;
3374}
3375
3376#else /* CONFIG_SLUB_TINY */
3377static inline void flush_all_cpus_locked(struct kmem_cache *s) { }
3378static inline void flush_all(struct kmem_cache *s) { }
3379static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) { }
3380static inline int slub_cpu_dead(unsigned int cpu) { return 0; }
3381#endif /* CONFIG_SLUB_TINY */
3382
3383/*
3384 * Check if the objects in a per cpu structure fit numa
3385 * locality expectations.
3386 */
3387static inline int node_match(struct slab *slab, int node)
3388{
3389#ifdef CONFIG_NUMA
3390	if (node != NUMA_NO_NODE && slab_nid(slab) != node)
3391		return 0;
3392#endif
3393	return 1;
3394}
3395
3396#ifdef CONFIG_SLUB_DEBUG
3397static int count_free(struct slab *slab)
3398{
3399	return slab->objects - slab->inuse;
3400}
3401
3402static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
3403{
3404	return atomic_long_read(&n->total_objects);
3405}
3406
3407/* Supports checking bulk free of a constructed freelist */
3408static inline bool free_debug_processing(struct kmem_cache *s,
3409	struct slab *slab, void *head, void *tail, int *bulk_cnt,
3410	unsigned long addr, depot_stack_handle_t handle)
3411{
3412	bool checks_ok = false;
3413	void *object = head;
3414	int cnt = 0;
3415
3416	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
3417		if (!check_slab(s, slab))
3418			goto out;
3419	}
3420
3421	if (slab->inuse < *bulk_cnt) {
3422		slab_err(s, slab, "Slab has %d allocated objects but %d are to be freed\n",
3423			 slab->inuse, *bulk_cnt);
3424		goto out;
3425	}
3426
3427next_object:
3428
3429	if (++cnt > *bulk_cnt)
3430		goto out_cnt;
3431
3432	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
3433		if (!free_consistency_checks(s, slab, object, addr))
3434			goto out;
3435	}
3436
3437	if (s->flags & SLAB_STORE_USER)
3438		set_track_update(s, object, TRACK_FREE, addr, handle);
3439	trace(s, slab, object, 0);
3440	/* Freepointer not overwritten by init_object(), SLAB_POISON moved it */
3441	init_object(s, object, SLUB_RED_INACTIVE);
3442
3443	/* Reached end of constructed freelist yet? */
3444	if (object != tail) {
3445		object = get_freepointer(s, object);
3446		goto next_object;
3447	}
3448	checks_ok = true;
3449
3450out_cnt:
3451	if (cnt != *bulk_cnt) {
3452		slab_err(s, slab, "Bulk free expected %d objects but found %d\n",
3453			 *bulk_cnt, cnt);
3454		*bulk_cnt = cnt;
3455	}
3456
3457out:
3458
3459	if (!checks_ok)
3460		slab_fix(s, "Object at 0x%p not freed", object);
3461
3462	return checks_ok;
3463}
3464#endif /* CONFIG_SLUB_DEBUG */
3465
3466#if defined(CONFIG_SLUB_DEBUG) || defined(SLAB_SUPPORTS_SYSFS)
3467static unsigned long count_partial(struct kmem_cache_node *n,
3468					int (*get_count)(struct slab *))
3469{
3470	unsigned long flags;
3471	unsigned long x = 0;
3472	struct slab *slab;
3473
3474	spin_lock_irqsave(&n->list_lock, flags);
3475	list_for_each_entry(slab, &n->partial, slab_list)
3476		x += get_count(slab);
3477	spin_unlock_irqrestore(&n->list_lock, flags);
3478	return x;
3479}
3480#endif /* CONFIG_SLUB_DEBUG || SLAB_SUPPORTS_SYSFS */
3481
3482#ifdef CONFIG_SLUB_DEBUG
3483#define MAX_PARTIAL_TO_SCAN 10000
3484
3485static unsigned long count_partial_free_approx(struct kmem_cache_node *n)
3486{
3487	unsigned long flags;
3488	unsigned long x = 0;
3489	struct slab *slab;
3490
3491	spin_lock_irqsave(&n->list_lock, flags);
3492	if (n->nr_partial <= MAX_PARTIAL_TO_SCAN) {
3493		list_for_each_entry(slab, &n->partial, slab_list)
3494			x += slab->objects - slab->inuse;
3495	} else {
3496		/*
3497		 * For a long list, approximate the total count of objects in
3498		 * it to meet the limit on the number of slabs to scan.
3499		 * Scan from both the list's head and tail for better accuracy.
3500		 */
3501		unsigned long scanned = 0;
3502
3503		list_for_each_entry(slab, &n->partial, slab_list) {
3504			x += slab->objects - slab->inuse;
3505			if (++scanned == MAX_PARTIAL_TO_SCAN / 2)
3506				break;
3507		}
3508		list_for_each_entry_reverse(slab, &n->partial, slab_list) {
3509			x += slab->objects - slab->inuse;
3510			if (++scanned == MAX_PARTIAL_TO_SCAN)
3511				break;
3512		}
3513		x = mult_frac(x, n->nr_partial, scanned);
3514		x = min(x, node_nr_objs(n));
3515	}
3516	spin_unlock_irqrestore(&n->list_lock, flags);
3517	return x;
3518}
 
3519
3520static noinline void
3521slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
3522{
 
3523	static DEFINE_RATELIMIT_STATE(slub_oom_rs, DEFAULT_RATELIMIT_INTERVAL,
3524				      DEFAULT_RATELIMIT_BURST);
3525	int cpu = raw_smp_processor_id();
3526	int node;
3527	struct kmem_cache_node *n;
3528
3529	if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slub_oom_rs))
3530		return;
3531
3532	pr_warn("SLUB: Unable to allocate memory on CPU %u (of node %d) on node %d, gfp=%#x(%pGg)\n",
3533		cpu, cpu_to_node(cpu), nid, gfpflags, &gfpflags);
3534	pr_warn("  cache: %s, object size: %u, buffer size: %u, default order: %u, min order: %u\n",
3535		s->name, s->object_size, s->size, oo_order(s->oo),
3536		oo_order(s->min));
3537
3538	if (oo_order(s->min) > get_order(s->object_size))
3539		pr_warn("  %s debugging increased min order, use slab_debug=O to disable.\n",
3540			s->name);
3541
3542	for_each_kmem_cache_node(s, node, n) {
3543		unsigned long nr_slabs;
3544		unsigned long nr_objs;
3545		unsigned long nr_free;
3546
3547		nr_free  = count_partial_free_approx(n);
3548		nr_slabs = node_nr_slabs(n);
3549		nr_objs  = node_nr_objs(n);
3550
3551		pr_warn("  node %d: slabs: %ld, objs: %ld, free: %ld\n",
3552			node, nr_slabs, nr_objs, nr_free);
3553	}
3554}
3555#else /* CONFIG_SLUB_DEBUG */
3556static inline void
3557slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid) { }
3558#endif
3559
3560static inline bool pfmemalloc_match(struct slab *slab, gfp_t gfpflags)
3561{
3562	if (unlikely(slab_test_pfmemalloc(slab)))
3563		return gfp_pfmemalloc_allowed(gfpflags);
3564
3565	return true;
3566}
3567
3568#ifndef CONFIG_SLUB_TINY
3569static inline bool
3570__update_cpu_freelist_fast(struct kmem_cache *s,
3571			   void *freelist_old, void *freelist_new,
3572			   unsigned long tid)
3573{
3574	freelist_aba_t old = { .freelist = freelist_old, .counter = tid };
3575	freelist_aba_t new = { .freelist = freelist_new, .counter = next_tid(tid) };
3576
3577	return this_cpu_try_cmpxchg_freelist(s->cpu_slab->freelist_tid.full,
3578					     &old.full, new.full);
3579}
3580
3581/*
3582 * Check the slab->freelist and either transfer the freelist to the
3583 * per cpu freelist or deactivate the slab.
3584 *
3585 * The slab is still frozen if the return value is not NULL.
3586 *
3587 * If this function returns NULL then the slab has been unfrozen.
3588 */
3589static inline void *get_freelist(struct kmem_cache *s, struct slab *slab)
3590{
3591	struct slab new;
3592	unsigned long counters;
3593	void *freelist;
 
 
3594
3595	lockdep_assert_held(this_cpu_ptr(&s->cpu_slab->lock));
3596
3597	do {
3598		freelist = slab->freelist;
3599		counters = slab->counters;
3600
3601		new.counters = counters;
 
 
 
 
3602
3603		new.inuse = slab->objects;
3604		new.frozen = freelist != NULL;
 
 
 
 
3605
3606	} while (!__slab_update_freelist(s, slab,
3607		freelist, counters,
3608		NULL, new.counters,
3609		"get_freelist"));
 
3610
3611	return freelist;
3612}
3613
 
 
 
 
 
 
 
 
3614/*
3615 * Freeze the partial slab and return the pointer to the freelist.
 
 
 
 
 
 
 
3616 */
3617static inline void *freeze_slab(struct kmem_cache *s, struct slab *slab)
3618{
3619	struct slab new;
3620	unsigned long counters;
3621	void *freelist;
3622
3623	do {
3624		freelist = slab->freelist;
3625		counters = slab->counters;
3626
3627		new.counters = counters;
3628		VM_BUG_ON(new.frozen);
3629
3630		new.inuse = slab->objects;
3631		new.frozen = 1;
3632
3633	} while (!slab_update_freelist(s, slab,
3634		freelist, counters,
3635		NULL, new.counters,
3636		"freeze_slab"));
3637
3638	return freelist;
3639}
3640
3641/*
3642 * Slow path. The lockless freelist is empty or we need to perform
3643 * debugging duties.
3644 *
3645 * Processing is still very fast if new objects have been freed to the
3646 * regular freelist. In that case we simply take over the regular freelist
3647 * as the lockless freelist and zap the regular freelist.
3648 *
3649 * If that is not working then we fall back to the partial lists. We take the
3650 * first element of the freelist as the object to allocate now and move the
3651 * rest of the freelist to the lockless freelist.
3652 *
3653 * And if we were unable to get a new slab from the partial slab lists then
3654 * we need to allocate a new slab. This is the slowest path since it involves
3655 * a call to the page allocator and the setup of a new slab.
3656 *
3657 * Version of __slab_alloc to use when we know that preemption is
3658 * already disabled (which is the case for bulk allocation).
3659 */
3660static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
3661			  unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size)
3662{
3663	void *freelist;
3664	struct slab *slab;
3665	unsigned long flags;
3666	struct partial_context pc;
3667	bool try_thisnode = true;
3668
3669	stat(s, ALLOC_SLOWPATH);
 
 
 
3670
3671reread_slab:
 
3672
3673	slab = READ_ONCE(c->slab);
3674	if (!slab) {
3675		/*
3676		 * if the node is not online or has no normal memory, just
3677		 * ignore the node constraint
3678		 */
3679		if (unlikely(node != NUMA_NO_NODE &&
3680			     !node_isset(node, slab_nodes)))
3681			node = NUMA_NO_NODE;
3682		goto new_slab;
3683	}
3684
3685	if (unlikely(!node_match(slab, node))) {
3686		/*
3687		 * same as above but node_match() being false already
3688		 * implies node != NUMA_NO_NODE
3689		 */
3690		if (!node_isset(node, slab_nodes)) {
3691			node = NUMA_NO_NODE;
3692		} else {
3693			stat(s, ALLOC_NODE_MISMATCH);
3694			goto deactivate_slab;
 
 
 
3695		}
3696	}
3697
3698	/*
3699	 * By rights, we should be searching for a slab page that was
3700	 * PFMEMALLOC but right now, we are losing the pfmemalloc
3701	 * information when the page leaves the per-cpu allocator
3702	 */
3703	if (unlikely(!pfmemalloc_match(slab, gfpflags)))
3704		goto deactivate_slab;
3705
3706	/* must check again c->slab in case we got preempted and it changed */
3707	local_lock_irqsave(&s->cpu_slab->lock, flags);
3708	if (unlikely(slab != c->slab)) {
3709		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3710		goto reread_slab;
3711	}
 
 
3712	freelist = c->freelist;
3713	if (freelist)
3714		goto load_freelist;
3715
3716	freelist = get_freelist(s, slab);
3717
3718	if (!freelist) {
3719		c->slab = NULL;
3720		c->tid = next_tid(c->tid);
3721		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3722		stat(s, DEACTIVATE_BYPASS);
3723		goto new_slab;
3724	}
3725
3726	stat(s, ALLOC_REFILL);
3727
3728load_freelist:
3729
3730	lockdep_assert_held(this_cpu_ptr(&s->cpu_slab->lock));
3731
3732	/*
3733	 * freelist is pointing to the list of objects to be used.
3734	 * slab is pointing to the slab from which the objects are obtained.
3735	 * That slab must be frozen for per cpu allocations to work.
3736	 */
3737	VM_BUG_ON(!c->slab->frozen);
3738	c->freelist = get_freepointer(s, freelist);
3739	c->tid = next_tid(c->tid);
3740	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3741	return freelist;
3742
3743deactivate_slab:
3744
3745	local_lock_irqsave(&s->cpu_slab->lock, flags);
3746	if (slab != c->slab) {
3747		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3748		goto reread_slab;
3749	}
3750	freelist = c->freelist;
3751	c->slab = NULL;
3752	c->freelist = NULL;
3753	c->tid = next_tid(c->tid);
3754	local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3755	deactivate_slab(s, slab, freelist);
3756
3757new_slab:
3758
3759#ifdef CONFIG_SLUB_CPU_PARTIAL
3760	while (slub_percpu_partial(c)) {
3761		local_lock_irqsave(&s->cpu_slab->lock, flags);
3762		if (unlikely(c->slab)) {
3763			local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3764			goto reread_slab;
3765		}
3766		if (unlikely(!slub_percpu_partial(c))) {
3767			local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3768			/* we were preempted and partial list got empty */
3769			goto new_objects;
3770		}
3771
3772		slab = slub_percpu_partial(c);
3773		slub_set_percpu_partial(c, slab);
3774
3775		if (likely(node_match(slab, node) &&
3776			   pfmemalloc_match(slab, gfpflags))) {
3777			c->slab = slab;
3778			freelist = get_freelist(s, slab);
3779			VM_BUG_ON(!freelist);
3780			stat(s, CPU_PARTIAL_ALLOC);
3781			goto load_freelist;
3782		}
3783
3784		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3785
3786		slab->next = NULL;
3787		__put_partials(s, slab);
3788	}
3789#endif
3790
3791new_objects:
3792
3793	pc.flags = gfpflags;
3794	/*
3795	 * When a preferred node is indicated but no __GFP_THISNODE
3796	 *
3797	 * 1) try to get a partial slab from target node only by having
3798	 *    __GFP_THISNODE in pc.flags for get_partial()
3799	 * 2) if 1) failed, try to allocate a new slab from target node with
3800	 *    GPF_NOWAIT | __GFP_THISNODE opportunistically
3801	 * 3) if 2) failed, retry with original gfpflags which will allow
3802	 *    get_partial() try partial lists of other nodes before potentially
3803	 *    allocating new page from other nodes
3804	 */
3805	if (unlikely(node != NUMA_NO_NODE && !(gfpflags & __GFP_THISNODE)
3806		     && try_thisnode))
3807		pc.flags = GFP_NOWAIT | __GFP_THISNODE;
3808
3809	pc.orig_size = orig_size;
3810	slab = get_partial(s, node, &pc);
3811	if (slab) {
3812		if (kmem_cache_debug(s)) {
3813			freelist = pc.object;
3814			/*
3815			 * For debug caches here we had to go through
3816			 * alloc_single_from_partial() so just store the
3817			 * tracking info and return the object.
3818			 */
3819			if (s->flags & SLAB_STORE_USER)
3820				set_track(s, freelist, TRACK_ALLOC, addr);
3821
3822			return freelist;
3823		}
3824
3825		freelist = freeze_slab(s, slab);
3826		goto retry_load_slab;
3827	}
3828
3829	slub_put_cpu_ptr(s->cpu_slab);
3830	slab = new_slab(s, pc.flags, node);
3831	c = slub_get_cpu_ptr(s->cpu_slab);
3832
3833	if (unlikely(!slab)) {
3834		if (node != NUMA_NO_NODE && !(gfpflags & __GFP_THISNODE)
3835		    && try_thisnode) {
3836			try_thisnode = false;
3837			goto new_objects;
3838		}
3839		slab_out_of_memory(s, gfpflags, node);
3840		return NULL;
3841	}
3842
3843	stat(s, ALLOC_SLAB);
3844
3845	if (kmem_cache_debug(s)) {
3846		freelist = alloc_single_from_new_slab(s, slab, orig_size);
3847
3848		if (unlikely(!freelist))
3849			goto new_objects;
3850
3851		if (s->flags & SLAB_STORE_USER)
3852			set_track(s, freelist, TRACK_ALLOC, addr);
3853
3854		return freelist;
3855	}
3856
3857	/*
3858	 * No other reference to the slab yet so we can
3859	 * muck around with it freely without cmpxchg
3860	 */
3861	freelist = slab->freelist;
3862	slab->freelist = NULL;
3863	slab->inuse = slab->objects;
3864	slab->frozen = 1;
3865
3866	inc_slabs_node(s, slab_nid(slab), slab->objects);
3867
3868	if (unlikely(!pfmemalloc_match(slab, gfpflags))) {
3869		/*
3870		 * For !pfmemalloc_match() case we don't load freelist so that
3871		 * we don't make further mismatched allocations easier.
3872		 */
3873		deactivate_slab(s, slab, get_freepointer(s, freelist));
3874		return freelist;
3875	}
3876
3877retry_load_slab:
3878
3879	local_lock_irqsave(&s->cpu_slab->lock, flags);
3880	if (unlikely(c->slab)) {
3881		void *flush_freelist = c->freelist;
3882		struct slab *flush_slab = c->slab;
3883
3884		c->slab = NULL;
3885		c->freelist = NULL;
3886		c->tid = next_tid(c->tid);
3887
3888		local_unlock_irqrestore(&s->cpu_slab->lock, flags);
3889
3890		deactivate_slab(s, flush_slab, flush_freelist);
3891
3892		stat(s, CPUSLAB_FLUSH);
3893
3894		goto retry_load_slab;
3895	}
3896	c->slab = slab;
 
3897
3898	goto load_freelist;
 
 
 
3899}
3900
3901/*
3902 * A wrapper for ___slab_alloc() for contexts where preemption is not yet
3903 * disabled. Compensates for possible cpu changes by refetching the per cpu area
3904 * pointer.
3905 */
3906static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
3907			  unsigned long addr, struct kmem_cache_cpu *c, unsigned int orig_size)
3908{
3909	void *p;
 
3910
3911#ifdef CONFIG_PREEMPT_COUNT
 
3912	/*
3913	 * We may have been preempted and rescheduled on a different
3914	 * cpu before disabling preemption. Need to reload cpu area
3915	 * pointer.
3916	 */
3917	c = slub_get_cpu_ptr(s->cpu_slab);
3918#endif
3919
3920	p = ___slab_alloc(s, gfpflags, node, addr, c, orig_size);
3921#ifdef CONFIG_PREEMPT_COUNT
3922	slub_put_cpu_ptr(s->cpu_slab);
3923#endif
3924	return p;
3925}
3926
3927static __always_inline void *__slab_alloc_node(struct kmem_cache *s,
3928		gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
 
 
 
 
 
 
 
 
 
 
3929{
 
3930	struct kmem_cache_cpu *c;
3931	struct slab *slab;
3932	unsigned long tid;
3933	void *object;
3934
 
 
 
3935redo:
3936	/*
3937	 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
3938	 * enabled. We may switch back and forth between cpus while
3939	 * reading from one cpu area. That does not matter as long
3940	 * as we end up on the original cpu again when doing the cmpxchg.
3941	 *
3942	 * We must guarantee that tid and kmem_cache_cpu are retrieved on the
3943	 * same cpu. We read first the kmem_cache_cpu pointer and use it to read
3944	 * the tid. If we are preempted and switched to another cpu between the
3945	 * two reads, it's OK as the two are still associated with the same cpu
3946	 * and cmpxchg later will validate the cpu.
3947	 */
3948	c = raw_cpu_ptr(s->cpu_slab);
3949	tid = READ_ONCE(c->tid);
 
 
 
3950
3951	/*
3952	 * Irqless object alloc/free algorithm used here depends on sequence
3953	 * of fetching cpu_slab's data. tid should be fetched before anything
3954	 * on c to guarantee that object and slab associated with previous tid
3955	 * won't be used with current tid. If we fetch tid first, object and
3956	 * slab could be one associated with next tid and our alloc/free
3957	 * request will be failed. In this case, we will retry. So, no problem.
3958	 */
3959	barrier();
3960
3961	/*
3962	 * The transaction ids are globally unique per cpu and per operation on
3963	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
3964	 * occurs on the right processor and that there was no operation on the
3965	 * linked list in between.
3966	 */
3967
3968	object = c->freelist;
3969	slab = c->slab;
3970
3971#ifdef CONFIG_NUMA
3972	if (static_branch_unlikely(&strict_numa) &&
3973			node == NUMA_NO_NODE) {
3974
3975		struct mempolicy *mpol = current->mempolicy;
3976
3977		if (mpol) {
3978			/*
3979			 * Special BIND rule support. If existing slab
3980			 * is in permitted set then do not redirect
3981			 * to a particular node.
3982			 * Otherwise we apply the memory policy to get
3983			 * the node we need to allocate on.
3984			 */
3985			if (mpol->mode != MPOL_BIND || !slab ||
3986					!node_isset(slab_nid(slab), mpol->nodes))
3987
3988				node = mempolicy_slab_node();
3989		}
3990	}
3991#endif
3992
3993	if (!USE_LOCKLESS_FAST_PATH() ||
3994	    unlikely(!object || !slab || !node_match(slab, node))) {
3995		object = __slab_alloc(s, gfpflags, node, addr, c, orig_size);
3996	} else {
3997		void *next_object = get_freepointer_safe(s, object);
3998
3999		/*
4000		 * The cmpxchg will only match if there was no additional
4001		 * operation and if we are on the right processor.
4002		 *
4003		 * The cmpxchg does the following atomically (without lock
4004		 * semantics!)
4005		 * 1. Relocate first pointer to the current per cpu area.
4006		 * 2. Verify that tid and freelist have not been changed
4007		 * 3. If they were not changed replace tid and freelist
4008		 *
4009		 * Since this is without lock semantics the protection is only
4010		 * against code executing on this cpu *not* from access by
4011		 * other cpus.
4012		 */
4013		if (unlikely(!__update_cpu_freelist_fast(s, object, next_object, tid))) {
 
 
 
 
4014			note_cmpxchg_failure("slab_alloc", s, tid);
4015			goto redo;
4016		}
4017		prefetch_freepointer(s, next_object);
4018		stat(s, ALLOC_FASTPATH);
4019	}
4020
4021	return object;
4022}
4023#else /* CONFIG_SLUB_TINY */
4024static void *__slab_alloc_node(struct kmem_cache *s,
4025		gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
4026{
4027	struct partial_context pc;
4028	struct slab *slab;
4029	void *object;
4030
4031	pc.flags = gfpflags;
4032	pc.orig_size = orig_size;
4033	slab = get_partial(s, node, &pc);
4034
4035	if (slab)
4036		return pc.object;
4037
4038	slab = new_slab(s, gfpflags, node);
4039	if (unlikely(!slab)) {
4040		slab_out_of_memory(s, gfpflags, node);
4041		return NULL;
4042	}
4043
4044	object = alloc_single_from_new_slab(s, slab, orig_size);
4045
4046	return object;
4047}
4048#endif /* CONFIG_SLUB_TINY */
4049
4050/*
4051 * If the object has been wiped upon free, make sure it's fully initialized by
4052 * zeroing out freelist pointer.
4053 *
4054 * Note that we also wipe custom freelist pointers.
4055 */
4056static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
4057						   void *obj)
4058{
4059	if (unlikely(slab_want_init_on_free(s)) && obj &&
4060	    !freeptr_outside_object(s))
4061		memset((void *)((char *)kasan_reset_tag(obj) + s->offset),
4062			0, sizeof(void *));
4063}
4064
4065static __fastpath_inline
4066struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
4067{
4068	flags &= gfp_allowed_mask;
4069
4070	might_alloc(flags);
4071
4072	if (unlikely(should_failslab(s, flags)))
4073		return NULL;
4074
4075	return s;
4076}
4077
4078static __fastpath_inline
4079bool slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru,
4080			  gfp_t flags, size_t size, void **p, bool init,
4081			  unsigned int orig_size)
4082{
4083	unsigned int zero_size = s->object_size;
4084	bool kasan_init = init;
4085	size_t i;
4086	gfp_t init_flags = flags & gfp_allowed_mask;
4087
4088	/*
4089	 * For kmalloc object, the allocated memory size(object_size) is likely
4090	 * larger than the requested size(orig_size). If redzone check is
4091	 * enabled for the extra space, don't zero it, as it will be redzoned
4092	 * soon. The redzone operation for this extra space could be seen as a
4093	 * replacement of current poisoning under certain debug option, and
4094	 * won't break other sanity checks.
4095	 */
4096	if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
4097	    (s->flags & SLAB_KMALLOC))
4098		zero_size = orig_size;
4099
4100	/*
4101	 * When slab_debug is enabled, avoid memory initialization integrated
4102	 * into KASAN and instead zero out the memory via the memset below with
4103	 * the proper size. Otherwise, KASAN might overwrite SLUB redzones and
4104	 * cause false-positive reports. This does not lead to a performance
4105	 * penalty on production builds, as slab_debug is not intended to be
4106	 * enabled there.
4107	 */
4108	if (__slub_debug_enabled())
4109		kasan_init = false;
4110
4111	/*
4112	 * As memory initialization might be integrated into KASAN,
4113	 * kasan_slab_alloc and initialization memset must be
4114	 * kept together to avoid discrepancies in behavior.
4115	 *
4116	 * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
4117	 */
4118	for (i = 0; i < size; i++) {
4119		p[i] = kasan_slab_alloc(s, p[i], init_flags, kasan_init);
4120		if (p[i] && init && (!kasan_init ||
4121				     !kasan_has_integrated_init()))
4122			memset(p[i], 0, zero_size);
4123		kmemleak_alloc_recursive(p[i], s->object_size, 1,
4124					 s->flags, init_flags);
4125		kmsan_slab_alloc(s, p[i], init_flags);
4126		alloc_tagging_slab_alloc_hook(s, p[i], flags);
4127	}
4128
4129	return memcg_slab_post_alloc_hook(s, lru, flags, size, p);
4130}
4131
4132/*
4133 * Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
4134 * have the fastpath folded into their functions. So no function call
4135 * overhead for requests that can be satisfied on the fastpath.
4136 *
4137 * The fastpath works by first checking if the lockless freelist can be used.
4138 * If not then __slab_alloc is called for slow processing.
4139 *
4140 * Otherwise we can simply pick the next object from the lockless free list.
4141 */
4142static __fastpath_inline void *slab_alloc_node(struct kmem_cache *s, struct list_lru *lru,
4143		gfp_t gfpflags, int node, unsigned long addr, size_t orig_size)
4144{
4145	void *object;
4146	bool init = false;
4147
4148	s = slab_pre_alloc_hook(s, gfpflags);
4149	if (unlikely(!s))
4150		return NULL;
4151
4152	object = kfence_alloc(s, orig_size, gfpflags);
4153	if (unlikely(object))
4154		goto out;
4155
4156	object = __slab_alloc_node(s, gfpflags, node, addr, orig_size);
4157
4158	maybe_wipe_obj_freeptr(s, object);
4159	init = slab_want_init_on_alloc(gfpflags, s);
4160
4161out:
4162	/*
4163	 * When init equals 'true', like for kzalloc() family, only
4164	 * @orig_size bytes might be zeroed instead of s->object_size
4165	 * In case this fails due to memcg_slab_post_alloc_hook(),
4166	 * object is set to NULL
4167	 */
4168	slab_post_alloc_hook(s, lru, gfpflags, 1, &object, init, orig_size);
4169
4170	return object;
4171}
4172
4173void *kmem_cache_alloc_noprof(struct kmem_cache *s, gfp_t gfpflags)
 
4174{
4175	void *ret = slab_alloc_node(s, NULL, gfpflags, NUMA_NO_NODE, _RET_IP_,
4176				    s->object_size);
4177
4178	trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE);
4179
4180	return ret;
4181}
4182EXPORT_SYMBOL(kmem_cache_alloc_noprof);
4183
4184void *kmem_cache_alloc_lru_noprof(struct kmem_cache *s, struct list_lru *lru,
4185			   gfp_t gfpflags)
4186{
4187	void *ret = slab_alloc_node(s, lru, gfpflags, NUMA_NO_NODE, _RET_IP_,
4188				    s->object_size);
4189
4190	trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, NUMA_NO_NODE);
 
4191
4192	return ret;
4193}
4194EXPORT_SYMBOL(kmem_cache_alloc_lru_noprof);
4195
4196bool kmem_cache_charge(void *objp, gfp_t gfpflags)
4197{
4198	if (!memcg_kmem_online())
4199		return true;
4200
4201	return memcg_slab_post_charge(objp, gfpflags);
4202}
4203EXPORT_SYMBOL(kmem_cache_charge);
4204
4205/**
4206 * kmem_cache_alloc_node - Allocate an object on the specified node
4207 * @s: The cache to allocate from.
4208 * @gfpflags: See kmalloc().
4209 * @node: node number of the target node.
4210 *
4211 * Identical to kmem_cache_alloc but it will allocate memory on the given
4212 * node, which can improve the performance for cpu bound structures.
4213 *
4214 * Fallback to other node is possible if __GFP_THISNODE is not set.
4215 *
4216 * Return: pointer to the new object or %NULL in case of error
4217 */
4218void *kmem_cache_alloc_node_noprof(struct kmem_cache *s, gfp_t gfpflags, int node)
4219{
4220	void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, s->object_size);
4221
4222	trace_kmem_cache_alloc(_RET_IP_, ret, s, gfpflags, node);
4223
4224	return ret;
4225}
4226EXPORT_SYMBOL(kmem_cache_alloc_node_noprof);
4227
4228/*
4229 * To avoid unnecessary overhead, we pass through large allocation requests
4230 * directly to the page allocator. We use __GFP_COMP, because we will need to
4231 * know the allocation order to free the pages properly in kfree.
4232 */
4233static void *___kmalloc_large_node(size_t size, gfp_t flags, int node)
4234{
4235	struct folio *folio;
4236	void *ptr = NULL;
4237	unsigned int order = get_order(size);
4238
4239	if (unlikely(flags & GFP_SLAB_BUG_MASK))
4240		flags = kmalloc_fix_flags(flags);
4241
4242	flags |= __GFP_COMP;
4243	folio = (struct folio *)alloc_pages_node_noprof(node, flags, order);
4244	if (folio) {
4245		ptr = folio_address(folio);
4246		lruvec_stat_mod_folio(folio, NR_SLAB_UNRECLAIMABLE_B,
4247				      PAGE_SIZE << order);
4248	}
4249
4250	ptr = kasan_kmalloc_large(ptr, size, flags);
4251	/* As ptr might get tagged, call kmemleak hook after KASAN. */
4252	kmemleak_alloc(ptr, size, 1, flags);
4253	kmsan_kmalloc_large(ptr, size, flags);
4254
4255	return ptr;
4256}
4257
4258void *__kmalloc_large_noprof(size_t size, gfp_t flags)
4259{
4260	void *ret = ___kmalloc_large_node(size, flags, NUMA_NO_NODE);
4261
4262	trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
4263		      flags, NUMA_NO_NODE);
4264	return ret;
4265}
4266EXPORT_SYMBOL(__kmalloc_large_noprof);
4267
4268void *__kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
4269{
4270	void *ret = ___kmalloc_large_node(size, flags, node);
4271
4272	trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
4273		      flags, node);
4274	return ret;
4275}
4276EXPORT_SYMBOL(__kmalloc_large_node_noprof);
4277
4278static __always_inline
4279void *__do_kmalloc_node(size_t size, kmem_buckets *b, gfp_t flags, int node,
4280			unsigned long caller)
4281{
4282	struct kmem_cache *s;
4283	void *ret;
4284
4285	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
4286		ret = __kmalloc_large_node_noprof(size, flags, node);
4287		trace_kmalloc(caller, ret, size,
4288			      PAGE_SIZE << get_order(size), flags, node);
4289		return ret;
4290	}
4291
4292	if (unlikely(!size))
4293		return ZERO_SIZE_PTR;
4294
4295	s = kmalloc_slab(size, b, flags, caller);
4296
4297	ret = slab_alloc_node(s, NULL, flags, node, caller, size);
4298	ret = kasan_kmalloc(s, ret, size, flags);
4299	trace_kmalloc(caller, ret, size, s->size, flags, node);
4300	return ret;
4301}
4302void *__kmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags, int node)
4303{
4304	return __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), flags, node, _RET_IP_);
4305}
4306EXPORT_SYMBOL(__kmalloc_node_noprof);
4307
4308void *__kmalloc_noprof(size_t size, gfp_t flags)
4309{
4310	return __do_kmalloc_node(size, NULL, flags, NUMA_NO_NODE, _RET_IP_);
4311}
4312EXPORT_SYMBOL(__kmalloc_noprof);
4313
4314void *__kmalloc_node_track_caller_noprof(DECL_BUCKET_PARAMS(size, b), gfp_t flags,
4315					 int node, unsigned long caller)
4316{
4317	return __do_kmalloc_node(size, PASS_BUCKET_PARAM(b), flags, node, caller);
4318
4319}
4320EXPORT_SYMBOL(__kmalloc_node_track_caller_noprof);
4321
4322void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t gfpflags, size_t size)
 
4323{
4324	void *ret = slab_alloc_node(s, NULL, gfpflags, NUMA_NO_NODE,
4325					    _RET_IP_, size);
4326
4327	trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, NUMA_NO_NODE);
 
4328
4329	ret = kasan_kmalloc(s, ret, size, gfpflags);
4330	return ret;
4331}
4332EXPORT_SYMBOL(__kmalloc_cache_noprof);
4333
4334void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
4335				  int node, size_t size)
 
 
4336{
4337	void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, size);
4338
4339	trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, node);
 
4340
4341	ret = kasan_kmalloc(s, ret, size, gfpflags);
4342	return ret;
4343}
4344EXPORT_SYMBOL(__kmalloc_cache_node_noprof);
4345
4346static noinline void free_to_partial_list(
4347	struct kmem_cache *s, struct slab *slab,
4348	void *head, void *tail, int bulk_cnt,
4349	unsigned long addr)
4350{
4351	struct kmem_cache_node *n = get_node(s, slab_nid(slab));
4352	struct slab *slab_free = NULL;
4353	int cnt = bulk_cnt;
4354	unsigned long flags;
4355	depot_stack_handle_t handle = 0;
4356
4357	if (s->flags & SLAB_STORE_USER)
4358		handle = set_track_prepare();
4359
4360	spin_lock_irqsave(&n->list_lock, flags);
4361
4362	if (free_debug_processing(s, slab, head, tail, &cnt, addr, handle)) {
4363		void *prior = slab->freelist;
4364
4365		/* Perform the actual freeing while we still hold the locks */
4366		slab->inuse -= cnt;
4367		set_freepointer(s, tail, prior);
4368		slab->freelist = head;
4369
4370		/*
4371		 * If the slab is empty, and node's partial list is full,
4372		 * it should be discarded anyway no matter it's on full or
4373		 * partial list.
4374		 */
4375		if (slab->inuse == 0 && n->nr_partial >= s->min_partial)
4376			slab_free = slab;
4377
4378		if (!prior) {
4379			/* was on full list */
4380			remove_full(s, n, slab);
4381			if (!slab_free) {
4382				add_partial(n, slab, DEACTIVATE_TO_TAIL);
4383				stat(s, FREE_ADD_PARTIAL);
4384			}
4385		} else if (slab_free) {
4386			remove_partial(n, slab);
4387			stat(s, FREE_REMOVE_PARTIAL);
4388		}
4389	}
4390
4391	if (slab_free) {
4392		/*
4393		 * Update the counters while still holding n->list_lock to
4394		 * prevent spurious validation warnings
4395		 */
4396		dec_slabs_node(s, slab_nid(slab_free), slab_free->objects);
4397	}
4398
4399	spin_unlock_irqrestore(&n->list_lock, flags);
4400
4401	if (slab_free) {
4402		stat(s, FREE_SLAB);
4403		free_slab(s, slab_free);
4404	}
4405}
4406
4407/*
4408 * Slow path handling. This may still be called frequently since objects
4409 * have a longer lifetime than the cpu slabs in most processing loads.
4410 *
4411 * So we still attempt to reduce cache line usage. Just take the slab
4412 * lock and free the item. If there is no additional partial slab
4413 * handling required then we can return immediately.
4414 */
4415static void __slab_free(struct kmem_cache *s, struct slab *slab,
4416			void *head, void *tail, int cnt,
4417			unsigned long addr)
4418
4419{
4420	void *prior;
4421	int was_frozen;
4422	struct slab new;
4423	unsigned long counters;
4424	struct kmem_cache_node *n = NULL;
4425	unsigned long flags;
4426	bool on_node_partial;
4427
4428	stat(s, FREE_SLOWPATH);
4429
4430	if (IS_ENABLED(CONFIG_SLUB_TINY) || kmem_cache_debug(s)) {
4431		free_to_partial_list(s, slab, head, tail, cnt, addr);
4432		return;
4433	}
4434
4435	do {
4436		if (unlikely(n)) {
4437			spin_unlock_irqrestore(&n->list_lock, flags);
4438			n = NULL;
4439		}
4440		prior = slab->freelist;
4441		counters = slab->counters;
4442		set_freepointer(s, tail, prior);
4443		new.counters = counters;
4444		was_frozen = new.frozen;
4445		new.inuse -= cnt;
4446		if ((!new.inuse || !prior) && !was_frozen) {
4447			/* Needs to be taken off a list */
4448			if (!kmem_cache_has_cpu_partial(s) || prior) {
4449
4450				n = get_node(s, slab_nid(slab));
 
 
 
 
 
 
 
 
 
 
 
 
4451				/*
4452				 * Speculatively acquire the list_lock.
4453				 * If the cmpxchg does not succeed then we may
4454				 * drop the list_lock without any processing.
4455				 *
4456				 * Otherwise the list_lock will synchronize with
4457				 * other processors updating the list of slabs.
4458				 */
4459				spin_lock_irqsave(&n->list_lock, flags);
4460
4461				on_node_partial = slab_test_node_partial(slab);
4462			}
4463		}
4464
4465	} while (!slab_update_freelist(s, slab,
4466		prior, counters,
4467		head, new.counters,
4468		"__slab_free"));
4469
4470	if (likely(!n)) {
4471
4472		if (likely(was_frozen)) {
4473			/*
4474			 * The list lock was not taken therefore no list
4475			 * activity can be necessary.
4476			 */
4477			stat(s, FREE_FROZEN);
4478		} else if (kmem_cache_has_cpu_partial(s) && !prior) {
4479			/*
4480			 * If we started with a full slab then put it onto the
4481			 * per cpu partial list.
4482			 */
4483			put_cpu_partial(s, slab, 1);
4484			stat(s, CPU_PARTIAL_FREE);
4485		}
4486
4487		return;
4488	}
4489
4490	/*
4491	 * This slab was partially empty but not on the per-node partial list,
4492	 * in which case we shouldn't manipulate its list, just return.
4493	 */
4494	if (prior && !on_node_partial) {
4495		spin_unlock_irqrestore(&n->list_lock, flags);
4496		return;
4497	}
4498
4499	if (unlikely(!new.inuse && n->nr_partial >= s->min_partial))
4500		goto slab_empty;
4501
4502	/*
4503	 * Objects left in the slab. If it was not on the partial list before
4504	 * then add it.
4505	 */
4506	if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
4507		add_partial(n, slab, DEACTIVATE_TO_TAIL);
 
 
4508		stat(s, FREE_ADD_PARTIAL);
4509	}
4510	spin_unlock_irqrestore(&n->list_lock, flags);
4511	return;
4512
4513slab_empty:
4514	if (prior) {
4515		/*
4516		 * Slab on the partial list.
4517		 */
4518		remove_partial(n, slab);
4519		stat(s, FREE_REMOVE_PARTIAL);
 
 
 
4520	}
4521
4522	spin_unlock_irqrestore(&n->list_lock, flags);
4523	stat(s, FREE_SLAB);
4524	discard_slab(s, slab);
4525}
4526
4527#ifndef CONFIG_SLUB_TINY
4528/*
4529 * Fastpath with forced inlining to produce a kfree and kmem_cache_free that
4530 * can perform fastpath freeing without additional function calls.
4531 *
4532 * The fastpath is only possible if we are freeing to the current cpu slab
4533 * of this processor. This typically the case if we have just allocated
4534 * the item before.
4535 *
4536 * If fastpath is not possible then fall back to __slab_free where we deal
4537 * with all sorts of special processing.
4538 *
4539 * Bulk free of a freelist with several objects (all pointing to the
4540 * same slab) possible by specifying head and tail ptr, plus objects
4541 * count (cnt). Bulk free indicated by tail pointer being set.
4542 */
4543static __always_inline void do_slab_free(struct kmem_cache *s,
4544				struct slab *slab, void *head, void *tail,
4545				int cnt, unsigned long addr)
4546{
 
4547	struct kmem_cache_cpu *c;
4548	unsigned long tid;
4549	void **freelist;
 
4550
4551redo:
4552	/*
4553	 * Determine the currently cpus per cpu slab.
4554	 * The cpu may change afterward. However that does not matter since
4555	 * data is retrieved via this pointer. If we are on the same cpu
4556	 * during the cmpxchg then the free will succeed.
4557	 */
4558	c = raw_cpu_ptr(s->cpu_slab);
4559	tid = READ_ONCE(c->tid);
 
 
 
4560
4561	/* Same with comment on barrier() in __slab_alloc_node() */
4562	barrier();
4563
4564	if (unlikely(slab != c->slab)) {
4565		__slab_free(s, slab, head, tail, cnt, addr);
4566		return;
4567	}
4568
4569	if (USE_LOCKLESS_FAST_PATH()) {
4570		freelist = READ_ONCE(c->freelist);
 
 
4571
4572		set_freepointer(s, tail, freelist);
4573
4574		if (unlikely(!__update_cpu_freelist_fast(s, freelist, head, tid))) {
4575			note_cmpxchg_failure("slab_free", s, tid);
4576			goto redo;
4577		}
4578	} else {
4579		/* Update the free list under the local lock */
4580		local_lock(&s->cpu_slab->lock);
4581		c = this_cpu_ptr(s->cpu_slab);
4582		if (unlikely(slab != c->slab)) {
4583			local_unlock(&s->cpu_slab->lock);
4584			goto redo;
4585		}
4586		tid = c->tid;
4587		freelist = c->freelist;
4588
4589		set_freepointer(s, tail, freelist);
4590		c->freelist = head;
4591		c->tid = next_tid(tid);
4592
4593		local_unlock(&s->cpu_slab->lock);
4594	}
4595	stat_add(s, FREE_FASTPATH, cnt);
4596}
4597#else /* CONFIG_SLUB_TINY */
4598static void do_slab_free(struct kmem_cache *s,
4599				struct slab *slab, void *head, void *tail,
4600				int cnt, unsigned long addr)
4601{
4602	__slab_free(s, slab, head, tail, cnt, addr);
4603}
4604#endif /* CONFIG_SLUB_TINY */
4605
4606static __fastpath_inline
4607void slab_free(struct kmem_cache *s, struct slab *slab, void *object,
4608	       unsigned long addr)
4609{
4610	memcg_slab_free_hook(s, slab, &object, 1);
4611	alloc_tagging_slab_free_hook(s, slab, &object, 1);
4612
4613	if (likely(slab_free_hook(s, object, slab_want_init_on_free(s), false)))
4614		do_slab_free(s, slab, object, object, 1, addr);
4615}
4616
4617#ifdef CONFIG_MEMCG
4618/* Do not inline the rare memcg charging failed path into the allocation path */
4619static noinline
4620void memcg_alloc_abort_single(struct kmem_cache *s, void *object)
4621{
4622	if (likely(slab_free_hook(s, object, slab_want_init_on_free(s), false)))
4623		do_slab_free(s, virt_to_slab(object), object, object, 1, _RET_IP_);
4624}
4625#endif
4626
4627static __fastpath_inline
4628void slab_free_bulk(struct kmem_cache *s, struct slab *slab, void *head,
4629		    void *tail, void **p, int cnt, unsigned long addr)
4630{
4631	memcg_slab_free_hook(s, slab, p, cnt);
4632	alloc_tagging_slab_free_hook(s, slab, p, cnt);
4633	/*
4634	 * With KASAN enabled slab_free_freelist_hook modifies the freelist
4635	 * to remove objects, whose reuse must be delayed.
4636	 */
4637	if (likely(slab_free_freelist_hook(s, &head, &tail, &cnt)))
4638		do_slab_free(s, slab, head, tail, cnt, addr);
4639}
4640
4641#ifdef CONFIG_SLUB_RCU_DEBUG
4642static void slab_free_after_rcu_debug(struct rcu_head *rcu_head)
4643{
4644	struct rcu_delayed_free *delayed_free =
4645			container_of(rcu_head, struct rcu_delayed_free, head);
4646	void *object = delayed_free->object;
4647	struct slab *slab = virt_to_slab(object);
4648	struct kmem_cache *s;
4649
4650	kfree(delayed_free);
4651
4652	if (WARN_ON(is_kfence_address(object)))
4653		return;
4654
4655	/* find the object and the cache again */
4656	if (WARN_ON(!slab))
4657		return;
4658	s = slab->slab_cache;
4659	if (WARN_ON(!(s->flags & SLAB_TYPESAFE_BY_RCU)))
4660		return;
4661
4662	/* resume freeing */
4663	if (slab_free_hook(s, object, slab_want_init_on_free(s), true))
4664		do_slab_free(s, slab, object, object, 1, _THIS_IP_);
4665}
4666#endif /* CONFIG_SLUB_RCU_DEBUG */
4667
4668#ifdef CONFIG_KASAN_GENERIC
4669void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr)
4670{
4671	do_slab_free(cache, virt_to_slab(x), x, x, 1, addr);
4672}
4673#endif
4674
4675static inline struct kmem_cache *virt_to_cache(const void *obj)
4676{
4677	struct slab *slab;
4678
4679	slab = virt_to_slab(obj);
4680	if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n", __func__))
4681		return NULL;
4682	return slab->slab_cache;
4683}
4684
4685static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
4686{
4687	struct kmem_cache *cachep;
4688
4689	if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) &&
4690	    !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS))
4691		return s;
4692
4693	cachep = virt_to_cache(x);
4694	if (WARN(cachep && cachep != s,
4695		 "%s: Wrong slab cache. %s but object is from %s\n",
4696		 __func__, s->name, cachep->name))
4697		print_tracking(cachep, x);
4698	return cachep;
4699}
4700
4701/**
4702 * kmem_cache_free - Deallocate an object
4703 * @s: The cache the allocation was from.
4704 * @x: The previously allocated object.
4705 *
4706 * Free an object which was previously allocated from this
4707 * cache.
4708 */
4709void kmem_cache_free(struct kmem_cache *s, void *x)
4710{
4711	s = cache_from_obj(s, x);
4712	if (!s)
4713		return;
4714	trace_kmem_cache_free(_RET_IP_, x, s);
4715	slab_free(s, virt_to_slab(x), x, _RET_IP_);
4716}
4717EXPORT_SYMBOL(kmem_cache_free);
4718
4719static void free_large_kmalloc(struct folio *folio, void *object)
4720{
4721	unsigned int order = folio_order(folio);
4722
4723	if (WARN_ON_ONCE(order == 0))
4724		pr_warn_once("object pointer: 0x%p\n", object);
4725
4726	kmemleak_free(object);
4727	kasan_kfree_large(object);
4728	kmsan_kfree_large(object);
4729
4730	lruvec_stat_mod_folio(folio, NR_SLAB_UNRECLAIMABLE_B,
4731			      -(PAGE_SIZE << order));
4732	folio_put(folio);
4733}
4734
4735/**
4736 * kfree - free previously allocated memory
4737 * @object: pointer returned by kmalloc() or kmem_cache_alloc()
4738 *
4739 * If @object is NULL, no operation is performed.
4740 */
4741void kfree(const void *object)
4742{
4743	struct folio *folio;
4744	struct slab *slab;
4745	struct kmem_cache *s;
4746	void *x = (void *)object;
4747
4748	trace_kfree(_RET_IP_, object);
4749
4750	if (unlikely(ZERO_OR_NULL_PTR(object)))
4751		return;
4752
4753	folio = virt_to_folio(object);
4754	if (unlikely(!folio_test_slab(folio))) {
4755		free_large_kmalloc(folio, (void *)object);
4756		return;
4757	}
4758
4759	slab = folio_slab(folio);
4760	s = slab->slab_cache;
4761	slab_free(s, slab, x, _RET_IP_);
4762}
4763EXPORT_SYMBOL(kfree);
4764
4765static __always_inline __realloc_size(2) void *
4766__do_krealloc(const void *p, size_t new_size, gfp_t flags)
4767{
4768	void *ret;
4769	size_t ks = 0;
4770	int orig_size = 0;
4771	struct kmem_cache *s = NULL;
4772
4773	if (unlikely(ZERO_OR_NULL_PTR(p)))
4774		goto alloc_new;
4775
4776	/* Check for double-free. */
4777	if (!kasan_check_byte(p))
4778		return NULL;
4779
4780	if (is_kfence_address(p)) {
4781		ks = orig_size = kfence_ksize(p);
4782	} else {
4783		struct folio *folio;
4784
4785		folio = virt_to_folio(p);
4786		if (unlikely(!folio_test_slab(folio))) {
4787			/* Big kmalloc object */
4788			WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE);
4789			WARN_ON(p != folio_address(folio));
4790			ks = folio_size(folio);
4791		} else {
4792			s = folio_slab(folio)->slab_cache;
4793			orig_size = get_orig_size(s, (void *)p);
4794			ks = s->object_size;
4795		}
4796	}
4797
4798	/* If the old object doesn't fit, allocate a bigger one */
4799	if (new_size > ks)
4800		goto alloc_new;
4801
4802	/* Zero out spare memory. */
4803	if (want_init_on_alloc(flags)) {
4804		kasan_disable_current();
4805		if (orig_size && orig_size < new_size)
4806			memset(kasan_reset_tag(p) + orig_size, 0, new_size - orig_size);
4807		else
4808			memset(kasan_reset_tag(p) + new_size, 0, ks - new_size);
4809		kasan_enable_current();
4810	}
4811
4812	/* Setup kmalloc redzone when needed */
4813	if (s && slub_debug_orig_size(s)) {
4814		set_orig_size(s, (void *)p, new_size);
4815		if (s->flags & SLAB_RED_ZONE && new_size < ks)
4816			memset_no_sanitize_memory(kasan_reset_tag(p) + new_size,
4817						SLUB_RED_ACTIVE, ks - new_size);
4818	}
4819
4820	p = kasan_krealloc(p, new_size, flags);
4821	return (void *)p;
4822
4823alloc_new:
4824	ret = kmalloc_node_track_caller_noprof(new_size, flags, NUMA_NO_NODE, _RET_IP_);
4825	if (ret && p) {
4826		/* Disable KASAN checks as the object's redzone is accessed. */
4827		kasan_disable_current();
4828		memcpy(ret, kasan_reset_tag(p), orig_size ?: ks);
4829		kasan_enable_current();
4830	}
4831
4832	return ret;
4833}
4834
4835/**
4836 * krealloc - reallocate memory. The contents will remain unchanged.
4837 * @p: object to reallocate memory for.
4838 * @new_size: how many bytes of memory are required.
4839 * @flags: the type of memory to allocate.
4840 *
4841 * If @p is %NULL, krealloc() behaves exactly like kmalloc().  If @new_size
4842 * is 0 and @p is not a %NULL pointer, the object pointed to is freed.
4843 *
4844 * If __GFP_ZERO logic is requested, callers must ensure that, starting with the
4845 * initial memory allocation, every subsequent call to this API for the same
4846 * memory allocation is flagged with __GFP_ZERO. Otherwise, it is possible that
4847 * __GFP_ZERO is not fully honored by this API.
4848 *
4849 * When slub_debug_orig_size() is off, krealloc() only knows about the bucket
4850 * size of an allocation (but not the exact size it was allocated with) and
4851 * hence implements the following semantics for shrinking and growing buffers
4852 * with __GFP_ZERO.
4853 *
4854 *         new             bucket
4855 * 0       size             size
4856 * |--------|----------------|
4857 * |  keep  |      zero      |
4858 *
4859 * Otherwise, the original allocation size 'orig_size' could be used to
4860 * precisely clear the requested size, and the new size will also be stored
4861 * as the new 'orig_size'.
4862 *
4863 * In any case, the contents of the object pointed to are preserved up to the
4864 * lesser of the new and old sizes.
4865 *
4866 * Return: pointer to the allocated memory or %NULL in case of error
4867 */
4868void *krealloc_noprof(const void *p, size_t new_size, gfp_t flags)
4869{
4870	void *ret;
4871
4872	if (unlikely(!new_size)) {
4873		kfree(p);
4874		return ZERO_SIZE_PTR;
4875	}
4876
4877	ret = __do_krealloc(p, new_size, flags);
4878	if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret))
4879		kfree(p);
4880
4881	return ret;
4882}
4883EXPORT_SYMBOL(krealloc_noprof);
4884
4885struct detached_freelist {
4886	struct slab *slab;
4887	void *tail;
4888	void *freelist;
4889	int cnt;
4890	struct kmem_cache *s;
4891};
4892
4893/*
4894 * This function progressively scans the array with free objects (with
4895 * a limited look ahead) and extract objects belonging to the same
4896 * slab.  It builds a detached freelist directly within the given
4897 * slab/objects.  This can happen without any need for
4898 * synchronization, because the objects are owned by running process.
4899 * The freelist is build up as a single linked list in the objects.
4900 * The idea is, that this detached freelist can then be bulk
4901 * transferred to the real freelist(s), but only requiring a single
4902 * synchronization primitive.  Look ahead in the array is limited due
4903 * to performance reasons.
4904 */
4905static inline
4906int build_detached_freelist(struct kmem_cache *s, size_t size,
4907			    void **p, struct detached_freelist *df)
4908{
 
4909	int lookahead = 3;
4910	void *object;
4911	struct folio *folio;
4912	size_t same;
 
 
4913
4914	object = p[--size];
4915	folio = virt_to_folio(object);
 
 
 
 
 
 
 
4916	if (!s) {
4917		/* Handle kalloc'ed objects */
4918		if (unlikely(!folio_test_slab(folio))) {
4919			free_large_kmalloc(folio, object);
4920			df->slab = NULL;
 
 
4921			return size;
4922		}
4923		/* Derive kmem_cache from object */
4924		df->slab = folio_slab(folio);
4925		df->s = df->slab->slab_cache;
4926	} else {
4927		df->slab = folio_slab(folio);
4928		df->s = cache_from_obj(s, object); /* Support for memcg */
4929	}
4930
4931	/* Start new detached freelist */
 
 
4932	df->tail = object;
4933	df->freelist = object;
 
4934	df->cnt = 1;
4935
4936	if (is_kfence_address(object))
4937		return size;
4938
4939	set_freepointer(df->s, object, NULL);
4940
4941	same = size;
4942	while (size) {
4943		object = p[--size];
4944		/* df->slab is always set at this point */
4945		if (df->slab == virt_to_slab(object)) {
 
 
 
4946			/* Opportunity build freelist */
4947			set_freepointer(df->s, object, df->freelist);
4948			df->freelist = object;
4949			df->cnt++;
4950			same--;
4951			if (size != same)
4952				swap(p[size], p[same]);
4953			continue;
4954		}
4955
4956		/* Limit look ahead search */
4957		if (!--lookahead)
4958			break;
4959	}
4960
4961	return same;
4962}
4963
4964/*
4965 * Internal bulk free of objects that were not initialised by the post alloc
4966 * hooks and thus should not be processed by the free hooks
4967 */
4968static void __kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
4969{
4970	if (!size)
4971		return;
4972
4973	do {
4974		struct detached_freelist df;
4975
4976		size = build_detached_freelist(s, size, p, &df);
4977		if (!df.slab)
4978			continue;
4979
4980		if (kfence_free(df.freelist))
4981			continue;
 
4982
4983		do_slab_free(df.s, df.slab, df.freelist, df.tail, df.cnt,
4984			     _RET_IP_);
4985	} while (likely(size));
4986}
4987
4988/* Note that interrupts must be enabled when calling this function. */
4989void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
4990{
4991	if (!size)
4992		return;
4993
4994	do {
4995		struct detached_freelist df;
4996
4997		size = build_detached_freelist(s, size, p, &df);
4998		if (!df.slab)
4999			continue;
5000
5001		slab_free_bulk(df.s, df.slab, df.freelist, df.tail, &p[size],
5002			       df.cnt, _RET_IP_);
5003	} while (likely(size));
5004}
5005EXPORT_SYMBOL(kmem_cache_free_bulk);
5006
5007#ifndef CONFIG_SLUB_TINY
5008static inline
5009int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
5010			    void **p)
5011{
5012	struct kmem_cache_cpu *c;
5013	unsigned long irqflags;
5014	int i;
5015
 
 
 
 
5016	/*
5017	 * Drain objects in the per cpu slab, while disabling local
5018	 * IRQs, which protects against PREEMPT and interrupts
5019	 * handlers invoking normal fastpath.
5020	 */
5021	c = slub_get_cpu_ptr(s->cpu_slab);
5022	local_lock_irqsave(&s->cpu_slab->lock, irqflags);
5023
5024	for (i = 0; i < size; i++) {
5025		void *object = kfence_alloc(s, s->object_size, flags);
5026
5027		if (unlikely(object)) {
5028			p[i] = object;
5029			continue;
5030		}
5031
5032		object = c->freelist;
5033		if (unlikely(!object)) {
5034			/*
5035			 * We may have removed an object from c->freelist using
5036			 * the fastpath in the previous iteration; in that case,
5037			 * c->tid has not been bumped yet.
5038			 * Since ___slab_alloc() may reenable interrupts while
5039			 * allocating memory, we should bump c->tid now.
5040			 */
5041			c->tid = next_tid(c->tid);
5042
5043			local_unlock_irqrestore(&s->cpu_slab->lock, irqflags);
5044
5045			/*
5046			 * Invoking slow path likely have side-effect
5047			 * of re-populating per CPU c->freelist
5048			 */
5049			p[i] = ___slab_alloc(s, flags, NUMA_NO_NODE,
5050					    _RET_IP_, c, s->object_size);
5051			if (unlikely(!p[i]))
5052				goto error;
5053
5054			c = this_cpu_ptr(s->cpu_slab);
5055			maybe_wipe_obj_freeptr(s, p[i]);
5056
5057			local_lock_irqsave(&s->cpu_slab->lock, irqflags);
5058
5059			continue; /* goto for-loop */
5060		}
5061		c->freelist = get_freepointer(s, object);
5062		p[i] = object;
5063		maybe_wipe_obj_freeptr(s, p[i]);
5064		stat(s, ALLOC_FASTPATH);
5065	}
5066	c->tid = next_tid(c->tid);
5067	local_unlock_irqrestore(&s->cpu_slab->lock, irqflags);
5068	slub_put_cpu_ptr(s->cpu_slab);
5069
5070	return i;
5071
5072error:
5073	slub_put_cpu_ptr(s->cpu_slab);
5074	__kmem_cache_free_bulk(s, i, p);
5075	return 0;
5076
5077}
5078#else /* CONFIG_SLUB_TINY */
5079static int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags,
5080				   size_t size, void **p)
5081{
5082	int i;
5083
5084	for (i = 0; i < size; i++) {
5085		void *object = kfence_alloc(s, s->object_size, flags);
5086
5087		if (unlikely(object)) {
5088			p[i] = object;
5089			continue;
5090		}
5091
5092		p[i] = __slab_alloc_node(s, flags, NUMA_NO_NODE,
5093					 _RET_IP_, s->object_size);
5094		if (unlikely(!p[i]))
5095			goto error;
5096
5097		maybe_wipe_obj_freeptr(s, p[i]);
 
5098	}
5099
 
 
5100	return i;
5101
5102error:
 
 
5103	__kmem_cache_free_bulk(s, i, p);
5104	return 0;
5105}
5106#endif /* CONFIG_SLUB_TINY */
5107
5108/* Note that interrupts must be enabled when calling this function. */
5109int kmem_cache_alloc_bulk_noprof(struct kmem_cache *s, gfp_t flags, size_t size,
5110				 void **p)
5111{
5112	int i;
5113
5114	if (!size)
5115		return 0;
5116
5117	s = slab_pre_alloc_hook(s, flags);
5118	if (unlikely(!s))
5119		return 0;
5120
5121	i = __kmem_cache_alloc_bulk(s, flags, size, p);
5122	if (unlikely(i == 0))
5123		return 0;
5124
5125	/*
5126	 * memcg and kmem_cache debug support and memory initialization.
5127	 * Done outside of the IRQ disabled fastpath loop.
5128	 */
5129	if (unlikely(!slab_post_alloc_hook(s, NULL, flags, size, p,
5130		    slab_want_init_on_alloc(flags, s), s->object_size))) {
5131		return 0;
5132	}
5133	return i;
5134}
5135EXPORT_SYMBOL(kmem_cache_alloc_bulk_noprof);
5136
5137
5138/*
5139 * Object placement in a slab is made very easy because we always start at
5140 * offset 0. If we tune the size of the object to the alignment then we can
5141 * get the required alignment by putting one properly sized object after
5142 * another.
5143 *
5144 * Notice that the allocation order determines the sizes of the per cpu
5145 * caches. Each processor has always one slab available for allocations.
5146 * Increasing the allocation order reduces the number of times that slabs
5147 * must be moved on and off the partial lists and is therefore a factor in
5148 * locking overhead.
5149 */
5150
5151/*
5152 * Minimum / Maximum order of slab pages. This influences locking overhead
5153 * and slab fragmentation. A higher order reduces the number of partial slabs
5154 * and increases the number of allocations possible without having to
5155 * take the list_lock.
5156 */
5157static unsigned int slub_min_order;
5158static unsigned int slub_max_order =
5159	IS_ENABLED(CONFIG_SLUB_TINY) ? 1 : PAGE_ALLOC_COSTLY_ORDER;
5160static unsigned int slub_min_objects;
5161
5162/*
5163 * Calculate the order of allocation given an slab object size.
5164 *
5165 * The order of allocation has significant impact on performance and other
5166 * system components. Generally order 0 allocations should be preferred since
5167 * order 0 does not cause fragmentation in the page allocator. Larger objects
5168 * be problematic to put into order 0 slabs because there may be too much
5169 * unused space left. We go to a higher order if more than 1/16th of the slab
5170 * would be wasted.
5171 *
5172 * In order to reach satisfactory performance we must ensure that a minimum
5173 * number of objects is in one slab. Otherwise we may generate too much
5174 * activity on the partial lists which requires taking the list_lock. This is
5175 * less a concern for large slabs though which are rarely used.
5176 *
5177 * slab_max_order specifies the order where we begin to stop considering the
5178 * number of objects in a slab as critical. If we reach slab_max_order then
5179 * we try to keep the page order as low as possible. So we accept more waste
5180 * of space in favor of a small page order.
5181 *
5182 * Higher order allocations also allow the placement of more objects in a
5183 * slab and thereby reduce object handling overhead. If the user has
5184 * requested a higher minimum order then we start with that one instead of
5185 * the smallest order which will fit the object.
5186 */
5187static inline unsigned int calc_slab_order(unsigned int size,
5188		unsigned int min_order, unsigned int max_order,
5189		unsigned int fract_leftover)
5190{
5191	unsigned int order;
 
 
5192
5193	for (order = min_order; order <= max_order; order++) {
 
5194
5195		unsigned int slab_size = (unsigned int)PAGE_SIZE << order;
5196		unsigned int rem;
5197
5198		rem = slab_size % size;
 
 
5199
5200		if (rem <= slab_size / fract_leftover)
5201			break;
5202	}
5203
5204	return order;
5205}
5206
5207static inline int calculate_order(unsigned int size)
5208{
5209	unsigned int order;
5210	unsigned int min_objects;
5211	unsigned int max_objects;
5212	unsigned int min_order;
5213
 
 
 
 
 
 
 
 
5214	min_objects = slub_min_objects;
5215	if (!min_objects) {
5216		/*
5217		 * Some architectures will only update present cpus when
5218		 * onlining them, so don't trust the number if it's just 1. But
5219		 * we also don't want to use nr_cpu_ids always, as on some other
5220		 * architectures, there can be many possible cpus, but never
5221		 * onlined. Here we compromise between trying to avoid too high
5222		 * order on systems that appear larger than they are, and too
5223		 * low order on systems that appear smaller than they are.
5224		 */
5225		unsigned int nr_cpus = num_present_cpus();
5226		if (nr_cpus <= 1)
5227			nr_cpus = nr_cpu_ids;
5228		min_objects = 4 * (fls(nr_cpus) + 1);
5229	}
5230	/* min_objects can't be 0 because get_order(0) is undefined */
5231	max_objects = max(order_objects(slub_max_order, size), 1U);
5232	min_objects = min(min_objects, max_objects);
5233
5234	min_order = max_t(unsigned int, slub_min_order,
5235			  get_order(min_objects * size));
5236	if (order_objects(min_order, size) > MAX_OBJS_PER_PAGE)
5237		return get_order(size * MAX_OBJS_PER_PAGE) - 1;
 
 
 
 
 
 
 
5238
5239	/*
5240	 * Attempt to find best configuration for a slab. This works by first
5241	 * attempting to generate a layout with the best possible configuration
5242	 * and backing off gradually.
5243	 *
5244	 * We start with accepting at most 1/16 waste and try to find the
5245	 * smallest order from min_objects-derived/slab_min_order up to
5246	 * slab_max_order that will satisfy the constraint. Note that increasing
5247	 * the order can only result in same or less fractional waste, not more.
5248	 *
5249	 * If that fails, we increase the acceptable fraction of waste and try
5250	 * again. The last iteration with fraction of 1/2 would effectively
5251	 * accept any waste and give us the order determined by min_objects, as
5252	 * long as at least single object fits within slab_max_order.
5253	 */
5254	for (unsigned int fraction = 16; fraction > 1; fraction /= 2) {
5255		order = calc_slab_order(size, min_order, slub_max_order,
5256					fraction);
5257		if (order <= slub_max_order)
5258			return order;
5259	}
5260
5261	/*
5262	 * Doh this slab cannot be placed using slab_max_order.
5263	 */
5264	order = get_order(size);
5265	if (order <= MAX_PAGE_ORDER)
5266		return order;
5267	return -ENOSYS;
5268}
5269
5270static void
5271init_kmem_cache_node(struct kmem_cache_node *n)
5272{
5273	n->nr_partial = 0;
5274	spin_lock_init(&n->list_lock);
5275	INIT_LIST_HEAD(&n->partial);
5276#ifdef CONFIG_SLUB_DEBUG
5277	atomic_long_set(&n->nr_slabs, 0);
5278	atomic_long_set(&n->total_objects, 0);
5279	INIT_LIST_HEAD(&n->full);
5280#endif
5281}
5282
5283#ifndef CONFIG_SLUB_TINY
5284static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
5285{
5286	BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
5287			NR_KMALLOC_TYPES * KMALLOC_SHIFT_HIGH *
5288			sizeof(struct kmem_cache_cpu));
5289
5290	/*
5291	 * Must align to double word boundary for the double cmpxchg
5292	 * instructions to work; see __pcpu_double_call_return_bool().
5293	 */
5294	s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu),
5295				     2 * sizeof(void *));
5296
5297	if (!s->cpu_slab)
5298		return 0;
5299
5300	init_kmem_cache_cpus(s);
5301
5302	return 1;
5303}
5304#else
5305static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
5306{
5307	return 1;
5308}
5309#endif /* CONFIG_SLUB_TINY */
5310
5311static struct kmem_cache *kmem_cache_node;
5312
5313/*
5314 * No kmalloc_node yet so do it by hand. We know that this is the first
5315 * slab on the node for this slabcache. There are no concurrent accesses
5316 * possible.
5317 *
5318 * Note that this function only works on the kmem_cache_node
5319 * when allocating for the kmem_cache_node. This is used for bootstrapping
5320 * memory on a fresh node that has no slab structures yet.
5321 */
5322static void early_kmem_cache_node_alloc(int node)
5323{
5324	struct slab *slab;
5325	struct kmem_cache_node *n;
5326
5327	BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
5328
5329	slab = new_slab(kmem_cache_node, GFP_NOWAIT, node);
5330
5331	BUG_ON(!slab);
5332	if (slab_nid(slab) != node) {
5333		pr_err("SLUB: Unable to allocate memory from node %d\n", node);
5334		pr_err("SLUB: Allocating a useless per node structure in order to be able to continue\n");
5335	}
5336
5337	n = slab->freelist;
5338	BUG_ON(!n);
 
 
 
 
5339#ifdef CONFIG_SLUB_DEBUG
5340	init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
 
5341#endif
5342	n = kasan_slab_alloc(kmem_cache_node, n, GFP_KERNEL, false);
5343	slab->freelist = get_freepointer(kmem_cache_node, n);
5344	slab->inuse = 1;
5345	kmem_cache_node->node[node] = n;
5346	init_kmem_cache_node(n);
5347	inc_slabs_node(kmem_cache_node, node, slab->objects);
5348
5349	/*
5350	 * No locks need to be taken here as it has just been
5351	 * initialized and there is no concurrent access.
5352	 */
5353	__add_partial(n, slab, DEACTIVATE_TO_HEAD);
5354}
5355
5356static void free_kmem_cache_nodes(struct kmem_cache *s)
5357{
5358	int node;
5359	struct kmem_cache_node *n;
5360
5361	for_each_kmem_cache_node(s, node, n) {
5362		s->node[node] = NULL;
5363		kmem_cache_free(kmem_cache_node, n);
 
5364	}
5365}
5366
5367void __kmem_cache_release(struct kmem_cache *s)
5368{
5369	cache_random_seq_destroy(s);
5370#ifndef CONFIG_SLUB_TINY
5371	free_percpu(s->cpu_slab);
5372#endif
5373	free_kmem_cache_nodes(s);
5374}
5375
5376static int init_kmem_cache_nodes(struct kmem_cache *s)
5377{
5378	int node;
5379
5380	for_each_node_mask(node, slab_nodes) {
5381		struct kmem_cache_node *n;
5382
5383		if (slab_state == DOWN) {
5384			early_kmem_cache_node_alloc(node);
5385			continue;
5386		}
5387		n = kmem_cache_alloc_node(kmem_cache_node,
5388						GFP_KERNEL, node);
5389
5390		if (!n) {
5391			free_kmem_cache_nodes(s);
5392			return 0;
5393		}
5394
5395		init_kmem_cache_node(n);
5396		s->node[node] = n;
 
5397	}
5398	return 1;
5399}
5400
5401static void set_cpu_partial(struct kmem_cache *s)
5402{
5403#ifdef CONFIG_SLUB_CPU_PARTIAL
5404	unsigned int nr_objects;
5405
5406	/*
5407	 * cpu_partial determined the maximum number of objects kept in the
5408	 * per cpu partial lists of a processor.
5409	 *
5410	 * Per cpu partial lists mainly contain slabs that just have one
5411	 * object freed. If they are used for allocation then they can be
5412	 * filled up again with minimal effort. The slab will never hit the
5413	 * per node partial lists and therefore no locking will be required.
5414	 *
5415	 * For backwards compatibility reasons, this is determined as number
5416	 * of objects, even though we now limit maximum number of pages, see
5417	 * slub_set_cpu_partial()
5418	 */
5419	if (!kmem_cache_has_cpu_partial(s))
5420		nr_objects = 0;
5421	else if (s->size >= PAGE_SIZE)
5422		nr_objects = 6;
5423	else if (s->size >= 1024)
5424		nr_objects = 24;
5425	else if (s->size >= 256)
5426		nr_objects = 52;
5427	else
5428		nr_objects = 120;
5429
5430	slub_set_cpu_partial(s, nr_objects);
5431#endif
5432}
5433
5434/*
5435 * calculate_sizes() determines the order and the distribution of data within
5436 * a slab object.
5437 */
5438static int calculate_sizes(struct kmem_cache_args *args, struct kmem_cache *s)
5439{
5440	slab_flags_t flags = s->flags;
5441	unsigned int size = s->object_size;
5442	unsigned int order;
5443
5444	/*
5445	 * Round up object size to the next word boundary. We can only
5446	 * place the free pointer at word boundaries and this determines
5447	 * the possible location of the free pointer.
5448	 */
5449	size = ALIGN(size, sizeof(void *));
5450
5451#ifdef CONFIG_SLUB_DEBUG
5452	/*
5453	 * Determine if we can poison the object itself. If the user of
5454	 * the slab may touch the object after free or before allocation
5455	 * then we should never poison the object itself.
5456	 */
5457	if ((flags & SLAB_POISON) && !(flags & SLAB_TYPESAFE_BY_RCU) &&
5458			!s->ctor)
5459		s->flags |= __OBJECT_POISON;
5460	else
5461		s->flags &= ~__OBJECT_POISON;
5462
5463
5464	/*
5465	 * If we are Redzoning then check if there is some space between the
5466	 * end of the object and the free pointer. If not then add an
5467	 * additional word to have some bytes to store Redzone information.
5468	 */
5469	if ((flags & SLAB_RED_ZONE) && size == s->object_size)
5470		size += sizeof(void *);
5471#endif
5472
5473	/*
5474	 * With that we have determined the number of bytes in actual use
5475	 * by the object and redzoning.
5476	 */
5477	s->inuse = size;
5478
5479	if (((flags & SLAB_TYPESAFE_BY_RCU) && !args->use_freeptr_offset) ||
5480	    (flags & SLAB_POISON) || s->ctor ||
5481	    ((flags & SLAB_RED_ZONE) &&
5482	     (s->object_size < sizeof(void *) || slub_debug_orig_size(s)))) {
5483		/*
5484		 * Relocate free pointer after the object if it is not
5485		 * permitted to overwrite the first word of the object on
5486		 * kmem_cache_free.
5487		 *
5488		 * This is the case if we do RCU, have a constructor or
5489		 * destructor, are poisoning the objects, or are
5490		 * redzoning an object smaller than sizeof(void *) or are
5491		 * redzoning an object with slub_debug_orig_size() enabled,
5492		 * in which case the right redzone may be extended.
5493		 *
5494		 * The assumption that s->offset >= s->inuse means free
5495		 * pointer is outside of the object is used in the
5496		 * freeptr_outside_object() function. If that is no
5497		 * longer true, the function needs to be modified.
5498		 */
5499		s->offset = size;
5500		size += sizeof(void *);
5501	} else if ((flags & SLAB_TYPESAFE_BY_RCU) && args->use_freeptr_offset) {
5502		s->offset = args->freeptr_offset;
5503	} else {
5504		/*
5505		 * Store freelist pointer near middle of object to keep
5506		 * it away from the edges of the object to avoid small
5507		 * sized over/underflows from neighboring allocations.
5508		 */
5509		s->offset = ALIGN_DOWN(s->object_size / 2, sizeof(void *));
5510	}
5511
5512#ifdef CONFIG_SLUB_DEBUG
5513	if (flags & SLAB_STORE_USER) {
5514		/*
5515		 * Need to store information about allocs and frees after
5516		 * the object.
5517		 */
5518		size += 2 * sizeof(struct track);
5519
5520		/* Save the original kmalloc request size */
5521		if (flags & SLAB_KMALLOC)
5522			size += sizeof(unsigned int);
5523	}
5524#endif
5525
5526	kasan_cache_create(s, &size, &s->flags);
5527#ifdef CONFIG_SLUB_DEBUG
5528	if (flags & SLAB_RED_ZONE) {
5529		/*
5530		 * Add some empty padding so that we can catch
5531		 * overwrites from earlier objects rather than let
5532		 * tracking information or the free pointer be
5533		 * corrupted if a user writes before the start
5534		 * of the object.
5535		 */
5536		size += sizeof(void *);
5537
5538		s->red_left_pad = sizeof(void *);
5539		s->red_left_pad = ALIGN(s->red_left_pad, s->align);
5540		size += s->red_left_pad;
5541	}
5542#endif
5543
5544	/*
5545	 * SLUB stores one object immediately after another beginning from
5546	 * offset 0. In order to align the objects we have to simply size
5547	 * each object to conform to the alignment.
5548	 */
5549	size = ALIGN(size, s->align);
5550	s->size = size;
5551	s->reciprocal_size = reciprocal_value(size);
5552	order = calculate_order(size);
 
 
5553
5554	if ((int)order < 0)
5555		return 0;
5556
5557	s->allocflags = __GFP_COMP;
 
 
5558
5559	if (s->flags & SLAB_CACHE_DMA)
5560		s->allocflags |= GFP_DMA;
5561
5562	if (s->flags & SLAB_CACHE_DMA32)
5563		s->allocflags |= GFP_DMA32;
5564
5565	if (s->flags & SLAB_RECLAIM_ACCOUNT)
5566		s->allocflags |= __GFP_RECLAIMABLE;
5567
5568	/*
5569	 * Determine the number of objects per slab
5570	 */
5571	s->oo = oo_make(order, size);
5572	s->min = oo_make(get_order(size), size);
 
 
5573
5574	return !!oo_objects(s->oo);
5575}
5576
5577static void list_slab_objects(struct kmem_cache *s, struct slab *slab,
5578			      const char *text)
5579{
5580#ifdef CONFIG_SLUB_DEBUG
5581	void *addr = slab_address(slab);
5582	void *p;
 
 
5583
5584	slab_err(s, slab, text, s->name);
 
 
 
 
 
 
 
 
 
 
 
 
 
5585
5586	spin_lock(&object_map_lock);
5587	__fill_map(object_map, s, slab);
 
 
 
 
5588
5589	for_each_object(p, s, addr, slab->objects) {
 
 
 
 
5590
5591		if (!test_bit(__obj_to_index(s, addr, p), object_map)) {
5592			if (slab_add_kunit_errors())
5593				continue;
5594			pr_err("Object 0x%p @offset=%tu\n", p, p - addr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5595			print_tracking(s, p);
5596		}
5597	}
5598	spin_unlock(&object_map_lock);
 
5599#endif
5600}
5601
5602/*
5603 * Attempt to free all partial slabs on a node.
5604 * This is called from __kmem_cache_shutdown(). We must take list_lock
5605 * because sysfs file might still access partial list after the shutdowning.
5606 */
5607static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
5608{
5609	LIST_HEAD(discard);
5610	struct slab *slab, *h;
5611
5612	BUG_ON(irqs_disabled());
5613	spin_lock_irq(&n->list_lock);
5614	list_for_each_entry_safe(slab, h, &n->partial, slab_list) {
5615		if (!slab->inuse) {
5616			remove_partial(n, slab);
5617			list_add(&slab->slab_list, &discard);
5618		} else {
5619			list_slab_objects(s, slab,
5620			  "Objects remaining in %s on __kmem_cache_shutdown()");
5621		}
5622	}
5623	spin_unlock_irq(&n->list_lock);
5624
5625	list_for_each_entry_safe(slab, h, &discard, slab_list)
5626		discard_slab(s, slab);
5627}
5628
5629bool __kmem_cache_empty(struct kmem_cache *s)
5630{
5631	int node;
5632	struct kmem_cache_node *n;
5633
5634	for_each_kmem_cache_node(s, node, n)
5635		if (n->nr_partial || node_nr_slabs(n))
5636			return false;
5637	return true;
5638}
5639
5640/*
5641 * Release all resources used by a slab cache.
5642 */
5643int __kmem_cache_shutdown(struct kmem_cache *s)
5644{
5645	int node;
5646	struct kmem_cache_node *n;
5647
5648	flush_all_cpus_locked(s);
5649	/* Attempt to free all objects */
5650	for_each_kmem_cache_node(s, node, n) {
5651		free_partial(s, n);
5652		if (n->nr_partial || node_nr_slabs(n))
5653			return 1;
5654	}
5655	return 0;
5656}
5657
5658#ifdef CONFIG_PRINTK
5659void __kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
5660{
5661	void *base;
5662	int __maybe_unused i;
5663	unsigned int objnr;
5664	void *objp;
5665	void *objp0;
5666	struct kmem_cache *s = slab->slab_cache;
5667	struct track __maybe_unused *trackp;
5668
5669	kpp->kp_ptr = object;
5670	kpp->kp_slab = slab;
5671	kpp->kp_slab_cache = s;
5672	base = slab_address(slab);
5673	objp0 = kasan_reset_tag(object);
5674#ifdef CONFIG_SLUB_DEBUG
5675	objp = restore_red_left(s, objp0);
5676#else
5677	objp = objp0;
5678#endif
5679	objnr = obj_to_index(s, slab, objp);
5680	kpp->kp_data_offset = (unsigned long)((char *)objp0 - (char *)objp);
5681	objp = base + s->size * objnr;
5682	kpp->kp_objp = objp;
5683	if (WARN_ON_ONCE(objp < base || objp >= base + slab->objects * s->size
5684			 || (objp - base) % s->size) ||
5685	    !(s->flags & SLAB_STORE_USER))
5686		return;
5687#ifdef CONFIG_SLUB_DEBUG
5688	objp = fixup_red_left(s, objp);
5689	trackp = get_track(s, objp, TRACK_ALLOC);
5690	kpp->kp_ret = (void *)trackp->addr;
5691#ifdef CONFIG_STACKDEPOT
5692	{
5693		depot_stack_handle_t handle;
5694		unsigned long *entries;
5695		unsigned int nr_entries;
5696
5697		handle = READ_ONCE(trackp->handle);
5698		if (handle) {
5699			nr_entries = stack_depot_fetch(handle, &entries);
5700			for (i = 0; i < KS_ADDRS_COUNT && i < nr_entries; i++)
5701				kpp->kp_stack[i] = (void *)entries[i];
5702		}
5703
5704		trackp = get_track(s, objp, TRACK_FREE);
5705		handle = READ_ONCE(trackp->handle);
5706		if (handle) {
5707			nr_entries = stack_depot_fetch(handle, &entries);
5708			for (i = 0; i < KS_ADDRS_COUNT && i < nr_entries; i++)
5709				kpp->kp_free_stack[i] = (void *)entries[i];
5710		}
5711	}
5712#endif
5713#endif
5714}
5715#endif
5716
5717/********************************************************************
5718 *		Kmalloc subsystem
5719 *******************************************************************/
5720
5721static int __init setup_slub_min_order(char *str)
5722{
5723	get_option(&str, (int *)&slub_min_order);
5724
5725	if (slub_min_order > slub_max_order)
5726		slub_max_order = slub_min_order;
5727
5728	return 1;
5729}
5730
5731__setup("slab_min_order=", setup_slub_min_order);
5732__setup_param("slub_min_order=", slub_min_order, setup_slub_min_order, 0);
5733
5734
5735static int __init setup_slub_max_order(char *str)
5736{
5737	get_option(&str, (int *)&slub_max_order);
5738	slub_max_order = min_t(unsigned int, slub_max_order, MAX_PAGE_ORDER);
5739
5740	if (slub_min_order > slub_max_order)
5741		slub_min_order = slub_max_order;
5742
5743	return 1;
5744}
5745
5746__setup("slab_max_order=", setup_slub_max_order);
5747__setup_param("slub_max_order=", slub_max_order, setup_slub_max_order, 0);
5748
5749static int __init setup_slub_min_objects(char *str)
5750{
5751	get_option(&str, (int *)&slub_min_objects);
5752
5753	return 1;
5754}
5755
5756__setup("slab_min_objects=", setup_slub_min_objects);
5757__setup_param("slub_min_objects=", slub_min_objects, setup_slub_min_objects, 0);
5758
5759#ifdef CONFIG_NUMA
5760static int __init setup_slab_strict_numa(char *str)
5761{
5762	if (nr_node_ids > 1) {
5763		static_branch_enable(&strict_numa);
5764		pr_info("SLUB: Strict NUMA enabled.\n");
5765	} else {
5766		pr_warn("slab_strict_numa parameter set on non NUMA system.\n");
5767	}
5768
5769	return 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5770}
 
5771
5772__setup("slab_strict_numa", setup_slab_strict_numa);
5773#endif
 
 
 
5774
 
 
 
 
5775
5776#ifdef CONFIG_HARDENED_USERCOPY
5777/*
5778 * Rejects incorrectly sized objects and objects that are to be copied
5779 * to/from userspace but do not fall entirely within the containing slab
5780 * cache's usercopy region.
5781 *
5782 * Returns NULL if check passes, otherwise const char * to name of cache
5783 * to indicate an error.
5784 */
5785void __check_heap_object(const void *ptr, unsigned long n,
5786			 const struct slab *slab, bool to_user)
5787{
5788	struct kmem_cache *s;
5789	unsigned int offset;
5790	bool is_kfence = is_kfence_address(ptr);
5791
5792	ptr = kasan_reset_tag(ptr);
 
5793
5794	/* Find object and usable object size. */
5795	s = slab->slab_cache;
 
5796
5797	/* Reject impossible pointers. */
5798	if (ptr < slab_address(slab))
5799		usercopy_abort("SLUB object not in SLUB page?!", NULL,
5800			       to_user, 0, n);
5801
5802	/* Find offset within object. */
5803	if (is_kfence)
5804		offset = ptr - kfence_object_start(ptr);
5805	else
5806		offset = (ptr - slab_address(slab)) % s->size;
 
5807
5808	/* Adjust for redzone and reject if within the redzone. */
5809	if (!is_kfence && kmem_cache_debug_flags(s, SLAB_RED_ZONE)) {
5810		if (offset < s->red_left_pad)
5811			usercopy_abort("SLUB object in left red zone",
5812				       s->name, to_user, offset, n);
5813		offset -= s->red_left_pad;
 
 
 
 
 
 
 
 
 
 
 
 
 
5814	}
5815
5816	/* Allow address range falling entirely within usercopy region. */
5817	if (offset >= s->useroffset &&
5818	    offset - s->useroffset <= s->usersize &&
5819	    n <= s->useroffset - offset + s->usersize)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5820		return;
5821
5822	usercopy_abort("SLUB object", s->name, to_user, offset, n);
 
 
 
 
 
 
 
5823}
5824#endif /* CONFIG_HARDENED_USERCOPY */
5825
5826#define SHRINK_PROMOTE_MAX 32
5827
5828/*
5829 * kmem_cache_shrink discards empty slabs and promotes the slabs filled
5830 * up most to the head of the partial lists. New allocations will then
5831 * fill those up and thus they can be removed from the partial lists.
5832 *
5833 * The slabs with the least items are placed last. This results in them
5834 * being allocated from last increasing the chance that the last objects
5835 * are freed in them.
5836 */
5837static int __kmem_cache_do_shrink(struct kmem_cache *s)
5838{
5839	int node;
5840	int i;
5841	struct kmem_cache_node *n;
5842	struct slab *slab;
5843	struct slab *t;
5844	struct list_head discard;
5845	struct list_head promote[SHRINK_PROMOTE_MAX];
5846	unsigned long flags;
5847	int ret = 0;
5848
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5849	for_each_kmem_cache_node(s, node, n) {
5850		INIT_LIST_HEAD(&discard);
5851		for (i = 0; i < SHRINK_PROMOTE_MAX; i++)
5852			INIT_LIST_HEAD(promote + i);
5853
5854		spin_lock_irqsave(&n->list_lock, flags);
5855
5856		/*
5857		 * Build lists of slabs to discard or promote.
5858		 *
5859		 * Note that concurrent frees may occur while we hold the
5860		 * list_lock. slab->inuse here is the upper limit.
5861		 */
5862		list_for_each_entry_safe(slab, t, &n->partial, slab_list) {
5863			int free = slab->objects - slab->inuse;
5864
5865			/* Do not reread slab->inuse */
5866			barrier();
5867
5868			/* We do not keep full slabs on the list */
5869			BUG_ON(free <= 0);
5870
5871			if (free == slab->objects) {
5872				list_move(&slab->slab_list, &discard);
5873				slab_clear_node_partial(slab);
5874				n->nr_partial--;
5875				dec_slabs_node(s, node, slab->objects);
5876			} else if (free <= SHRINK_PROMOTE_MAX)
5877				list_move(&slab->slab_list, promote + free - 1);
5878		}
5879
5880		/*
5881		 * Promote the slabs filled up most to the head of the
5882		 * partial list.
5883		 */
5884		for (i = SHRINK_PROMOTE_MAX - 1; i >= 0; i--)
5885			list_splice(promote + i, &n->partial);
5886
5887		spin_unlock_irqrestore(&n->list_lock, flags);
5888
5889		/* Release empty slabs */
5890		list_for_each_entry_safe(slab, t, &discard, slab_list)
5891			free_slab(s, slab);
5892
5893		if (node_nr_slabs(n))
5894			ret = 1;
5895	}
5896
5897	return ret;
5898}
5899
5900int __kmem_cache_shrink(struct kmem_cache *s)
5901{
5902	flush_all(s);
5903	return __kmem_cache_do_shrink(s);
5904}
5905
5906static int slab_mem_going_offline_callback(void *arg)
5907{
5908	struct kmem_cache *s;
5909
5910	mutex_lock(&slab_mutex);
5911	list_for_each_entry(s, &slab_caches, list) {
5912		flush_all_cpus_locked(s);
5913		__kmem_cache_do_shrink(s);
5914	}
5915	mutex_unlock(&slab_mutex);
5916
5917	return 0;
5918}
5919
5920static void slab_mem_offline_callback(void *arg)
5921{
 
 
5922	struct memory_notify *marg = arg;
5923	int offline_node;
5924
5925	offline_node = marg->status_change_nid_normal;
5926
5927	/*
5928	 * If the node still has available memory. we need kmem_cache_node
5929	 * for it yet.
5930	 */
5931	if (offline_node < 0)
5932		return;
5933
5934	mutex_lock(&slab_mutex);
5935	node_clear(offline_node, slab_nodes);
5936	/*
5937	 * We no longer free kmem_cache_node structures here, as it would be
5938	 * racy with all get_node() users, and infeasible to protect them with
5939	 * slab_mutex.
5940	 */
 
 
 
 
 
 
 
 
 
5941	mutex_unlock(&slab_mutex);
5942}
5943
5944static int slab_mem_going_online_callback(void *arg)
5945{
5946	struct kmem_cache_node *n;
5947	struct kmem_cache *s;
5948	struct memory_notify *marg = arg;
5949	int nid = marg->status_change_nid_normal;
5950	int ret = 0;
5951
5952	/*
5953	 * If the node's memory is already available, then kmem_cache_node is
5954	 * already created. Nothing to do.
5955	 */
5956	if (nid < 0)
5957		return 0;
5958
5959	/*
5960	 * We are bringing a node online. No memory is available yet. We must
5961	 * allocate a kmem_cache_node structure in order to bring the node
5962	 * online.
5963	 */
5964	mutex_lock(&slab_mutex);
5965	list_for_each_entry(s, &slab_caches, list) {
5966		/*
5967		 * The structure may already exist if the node was previously
5968		 * onlined and offlined.
5969		 */
5970		if (get_node(s, nid))
5971			continue;
5972		/*
5973		 * XXX: kmem_cache_alloc_node will fallback to other nodes
5974		 *      since memory is not yet available from the node that
5975		 *      is brought up.
5976		 */
5977		n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
5978		if (!n) {
5979			ret = -ENOMEM;
5980			goto out;
5981		}
5982		init_kmem_cache_node(n);
5983		s->node[nid] = n;
5984	}
5985	/*
5986	 * Any cache created after this point will also have kmem_cache_node
5987	 * initialized for the new node.
5988	 */
5989	node_set(nid, slab_nodes);
5990out:
5991	mutex_unlock(&slab_mutex);
5992	return ret;
5993}
5994
5995static int slab_memory_callback(struct notifier_block *self,
5996				unsigned long action, void *arg)
5997{
5998	int ret = 0;
5999
6000	switch (action) {
6001	case MEM_GOING_ONLINE:
6002		ret = slab_mem_going_online_callback(arg);
6003		break;
6004	case MEM_GOING_OFFLINE:
6005		ret = slab_mem_going_offline_callback(arg);
6006		break;
6007	case MEM_OFFLINE:
6008	case MEM_CANCEL_ONLINE:
6009		slab_mem_offline_callback(arg);
6010		break;
6011	case MEM_ONLINE:
6012	case MEM_CANCEL_OFFLINE:
6013		break;
6014	}
6015	if (ret)
6016		ret = notifier_from_errno(ret);
6017	else
6018		ret = NOTIFY_OK;
6019	return ret;
6020}
6021
 
 
 
 
 
6022/********************************************************************
6023 *			Basic setup of slabs
6024 *******************************************************************/
6025
6026/*
6027 * Used for early kmem_cache structures that were allocated using
6028 * the page allocator. Allocate them properly then fix up the pointers
6029 * that may be pointing to the wrong kmem_cache structure.
6030 */
6031
6032static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache)
6033{
6034	int node;
6035	struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
6036	struct kmem_cache_node *n;
6037
6038	memcpy(s, static_cache, kmem_cache->object_size);
6039
6040	/*
6041	 * This runs very early, and only the boot processor is supposed to be
6042	 * up.  Even if it weren't true, IRQs are not up so we couldn't fire
6043	 * IPIs around.
6044	 */
6045	__flush_cpu_slab(s, smp_processor_id());
6046	for_each_kmem_cache_node(s, node, n) {
6047		struct slab *p;
6048
6049		list_for_each_entry(p, &n->partial, slab_list)
6050			p->slab_cache = s;
6051
6052#ifdef CONFIG_SLUB_DEBUG
6053		list_for_each_entry(p, &n->full, slab_list)
6054			p->slab_cache = s;
6055#endif
6056	}
 
6057	list_add(&s->list, &slab_caches);
6058	return s;
6059}
6060
6061void __init kmem_cache_init(void)
6062{
6063	static __initdata struct kmem_cache boot_kmem_cache,
6064		boot_kmem_cache_node;
6065	int node;
6066
6067	if (debug_guardpage_minorder())
6068		slub_max_order = 0;
6069
6070	/* Print slub debugging pointers without hashing */
6071	if (__slub_debug_enabled())
6072		no_hash_pointers_enable(NULL);
6073
6074	kmem_cache_node = &boot_kmem_cache_node;
6075	kmem_cache = &boot_kmem_cache;
6076
6077	/*
6078	 * Initialize the nodemask for which we will allocate per node
6079	 * structures. Here we don't need taking slab_mutex yet.
6080	 */
6081	for_each_node_state(node, N_NORMAL_MEMORY)
6082		node_set(node, slab_nodes);
6083
6084	create_boot_cache(kmem_cache_node, "kmem_cache_node",
6085			sizeof(struct kmem_cache_node),
6086			SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0);
6087
6088	hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
6089
6090	/* Able to allocate the per node structures */
6091	slab_state = PARTIAL;
6092
6093	create_boot_cache(kmem_cache, "kmem_cache",
6094			offsetof(struct kmem_cache, node) +
6095				nr_node_ids * sizeof(struct kmem_cache_node *),
6096			SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0);
6097
6098	kmem_cache = bootstrap(&boot_kmem_cache);
 
 
 
 
 
 
6099	kmem_cache_node = bootstrap(&boot_kmem_cache_node);
6100
6101	/* Now we can use the kmem_cache to allocate kmalloc slabs */
6102	setup_kmalloc_cache_index_table();
6103	create_kmalloc_caches();
6104
6105	/* Setup random freelists for each cache */
6106	init_freelist_randomization();
6107
6108	cpuhp_setup_state_nocalls(CPUHP_SLUB_DEAD, "slub:dead", NULL,
6109				  slub_cpu_dead);
 
6110
6111	pr_info("SLUB: HWalign=%d, Order=%u-%u, MinObjects=%u, CPUs=%u, Nodes=%u\n",
6112		cache_line_size(),
6113		slub_min_order, slub_max_order, slub_min_objects,
6114		nr_cpu_ids, nr_node_ids);
6115}
6116
6117void __init kmem_cache_init_late(void)
6118{
6119#ifndef CONFIG_SLUB_TINY
6120	flushwq = alloc_workqueue("slub_flushwq", WQ_MEM_RECLAIM, 0);
6121	WARN_ON(!flushwq);
6122#endif
6123}
6124
6125struct kmem_cache *
6126__kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
6127		   slab_flags_t flags, void (*ctor)(void *))
6128{
6129	struct kmem_cache *s;
6130
6131	s = find_mergeable(size, align, flags, name, ctor);
6132	if (s) {
6133		if (sysfs_slab_alias(s, name))
6134			pr_err("SLUB: Unable to add cache alias %s to sysfs\n",
6135			       name);
6136
6137		s->refcount++;
6138
6139		/*
6140		 * Adjust the object sizes so that we clear
6141		 * the complete object on kzalloc.
6142		 */
6143		s->object_size = max(s->object_size, size);
6144		s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
 
 
 
 
 
 
 
 
 
 
 
6145	}
6146
6147	return s;
6148}
6149
6150int do_kmem_cache_create(struct kmem_cache *s, const char *name,
6151			 unsigned int size, struct kmem_cache_args *args,
6152			 slab_flags_t flags)
6153{
6154	int err = -EINVAL;
6155
6156	s->name = name;
6157	s->size = s->object_size = size;
 
6158
6159	s->flags = kmem_cache_flags(flags, s->name);
6160#ifdef CONFIG_SLAB_FREELIST_HARDENED
6161	s->random = get_random_long();
6162#endif
6163	s->align = args->align;
6164	s->ctor = args->ctor;
6165#ifdef CONFIG_HARDENED_USERCOPY
6166	s->useroffset = args->useroffset;
6167	s->usersize = args->usersize;
6168#endif
6169
6170	if (!calculate_sizes(args, s))
6171		goto out;
6172	if (disable_higher_order_debug) {
6173		/*
6174		 * Disable debugging flags that store metadata if the min slab
6175		 * order increased.
6176		 */
6177		if (get_order(s->size) > get_order(s->object_size)) {
6178			s->flags &= ~DEBUG_METADATA_FLAGS;
6179			s->offset = 0;
6180			if (!calculate_sizes(args, s))
6181				goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6182		}
 
 
 
 
6183	}
 
 
 
 
 
 
6184
6185#ifdef system_has_freelist_aba
6186	if (system_has_freelist_aba() && !(s->flags & SLAB_NO_CMPXCHG)) {
6187		/* Enable fast mode */
6188		s->flags |= __CMPXCHG_DOUBLE;
6189	}
6190#endif
6191
6192	/*
6193	 * The larger the object size is, the more slabs we want on the partial
6194	 * list to avoid pounding the page allocator excessively.
6195	 */
6196	s->min_partial = min_t(unsigned long, MAX_PARTIAL, ilog2(s->size) / 2);
6197	s->min_partial = max_t(unsigned long, MIN_PARTIAL, s->min_partial);
 
6198
6199	set_cpu_partial(s);
 
 
 
 
 
 
 
 
 
 
 
6200
6201#ifdef CONFIG_NUMA
6202	s->remote_node_defrag_ratio = 1000;
6203#endif
 
 
 
6204
6205	/* Initialize the pre-computed randomized freelist if slab is up */
6206	if (slab_state >= UP) {
6207		if (init_cache_random_seq(s))
6208			goto out;
6209	}
6210
6211	if (!init_kmem_cache_nodes(s))
6212		goto out;
 
6213
6214	if (!alloc_kmem_cache_cpus(s))
6215		goto out;
6216
6217	err = 0;
6218
6219	/* Mutex is not taken during early boot */
6220	if (slab_state <= UP)
6221		goto out;
6222
6223	/*
6224	 * Failing to create sysfs files is not critical to SLUB functionality.
6225	 * If it fails, proceed with cache creation without these files.
6226	 */
6227	if (sysfs_slab_add(s))
6228		pr_err("SLUB: Unable to add cache %s to sysfs\n", s->name);
6229
6230	if (s->flags & SLAB_STORE_USER)
6231		debugfs_slab_add(s);
6232
6233out:
6234	if (err)
6235		__kmem_cache_release(s);
6236	return err;
6237}
 
6238
6239#ifdef SLAB_SUPPORTS_SYSFS
6240static int count_inuse(struct slab *slab)
6241{
6242	return slab->inuse;
6243}
6244
6245static int count_total(struct slab *slab)
6246{
6247	return slab->objects;
6248}
6249#endif
6250
6251#ifdef CONFIG_SLUB_DEBUG
6252static void validate_slab(struct kmem_cache *s, struct slab *slab,
6253			  unsigned long *obj_map)
6254{
6255	void *p;
6256	void *addr = slab_address(slab);
6257
6258	if (!check_slab(s, slab) || !on_freelist(s, slab, NULL))
6259		return;
 
6260
6261	/* Now we know that a valid freelist exists */
6262	__fill_map(obj_map, s, slab);
6263	for_each_object(p, s, addr, slab->objects) {
6264		u8 val = test_bit(__obj_to_index(s, addr, p), obj_map) ?
6265			 SLUB_RED_INACTIVE : SLUB_RED_ACTIVE;
6266
6267		if (!check_object(s, slab, p, val))
6268			break;
 
 
 
6269	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6270}
6271
6272static int validate_slab_node(struct kmem_cache *s,
6273		struct kmem_cache_node *n, unsigned long *obj_map)
6274{
6275	unsigned long count = 0;
6276	struct slab *slab;
6277	unsigned long flags;
6278
6279	spin_lock_irqsave(&n->list_lock, flags);
6280
6281	list_for_each_entry(slab, &n->partial, slab_list) {
6282		validate_slab(s, slab, obj_map);
6283		count++;
6284	}
6285	if (count != n->nr_partial) {
6286		pr_err("SLUB %s: %ld partial slabs counted but counter=%ld\n",
6287		       s->name, count, n->nr_partial);
6288		slab_add_kunit_errors();
6289	}
6290
6291	if (!(s->flags & SLAB_STORE_USER))
6292		goto out;
6293
6294	list_for_each_entry(slab, &n->full, slab_list) {
6295		validate_slab(s, slab, obj_map);
6296		count++;
6297	}
6298	if (count != node_nr_slabs(n)) {
6299		pr_err("SLUB: %s %ld slabs counted but counter=%ld\n",
6300		       s->name, count, node_nr_slabs(n));
6301		slab_add_kunit_errors();
6302	}
6303
6304out:
6305	spin_unlock_irqrestore(&n->list_lock, flags);
6306	return count;
6307}
6308
6309long validate_slab_cache(struct kmem_cache *s)
6310{
6311	int node;
6312	unsigned long count = 0;
 
 
6313	struct kmem_cache_node *n;
6314	unsigned long *obj_map;
6315
6316	obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
6317	if (!obj_map)
6318		return -ENOMEM;
6319
6320	flush_all(s);
6321	for_each_kmem_cache_node(s, node, n)
6322		count += validate_slab_node(s, n, obj_map);
6323
6324	bitmap_free(obj_map);
6325
6326	return count;
6327}
6328EXPORT_SYMBOL(validate_slab_cache);
6329
6330#ifdef CONFIG_DEBUG_FS
6331/*
6332 * Generate lists of code addresses where slabcache objects are allocated
6333 * and freed.
6334 */
6335
6336struct location {
6337	depot_stack_handle_t handle;
6338	unsigned long count;
6339	unsigned long addr;
6340	unsigned long waste;
6341	long long sum_time;
6342	long min_time;
6343	long max_time;
6344	long min_pid;
6345	long max_pid;
6346	DECLARE_BITMAP(cpus, NR_CPUS);
6347	nodemask_t nodes;
6348};
6349
6350struct loc_track {
6351	unsigned long max;
6352	unsigned long count;
6353	struct location *loc;
6354	loff_t idx;
6355};
6356
6357static struct dentry *slab_debugfs_root;
6358
6359static void free_loc_track(struct loc_track *t)
6360{
6361	if (t->max)
6362		free_pages((unsigned long)t->loc,
6363			get_order(sizeof(struct location) * t->max));
6364}
6365
6366static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
6367{
6368	struct location *l;
6369	int order;
6370
6371	order = get_order(sizeof(struct location) * max);
6372
6373	l = (void *)__get_free_pages(flags, order);
6374	if (!l)
6375		return 0;
6376
6377	if (t->count) {
6378		memcpy(l, t->loc, sizeof(struct location) * t->count);
6379		free_loc_track(t);
6380	}
6381	t->max = max;
6382	t->loc = l;
6383	return 1;
6384}
6385
6386static int add_location(struct loc_track *t, struct kmem_cache *s,
6387				const struct track *track,
6388				unsigned int orig_size)
6389{
6390	long start, end, pos;
6391	struct location *l;
6392	unsigned long caddr, chandle, cwaste;
6393	unsigned long age = jiffies - track->when;
6394	depot_stack_handle_t handle = 0;
6395	unsigned int waste = s->object_size - orig_size;
6396
6397#ifdef CONFIG_STACKDEPOT
6398	handle = READ_ONCE(track->handle);
6399#endif
6400	start = -1;
6401	end = t->count;
6402
6403	for ( ; ; ) {
6404		pos = start + (end - start + 1) / 2;
6405
6406		/*
6407		 * There is nothing at "end". If we end up there
6408		 * we need to add something to before end.
6409		 */
6410		if (pos == end)
6411			break;
6412
6413		l = &t->loc[pos];
6414		caddr = l->addr;
6415		chandle = l->handle;
6416		cwaste = l->waste;
6417		if ((track->addr == caddr) && (handle == chandle) &&
6418			(waste == cwaste)) {
6419
 
6420			l->count++;
6421			if (track->when) {
6422				l->sum_time += age;
6423				if (age < l->min_time)
6424					l->min_time = age;
6425				if (age > l->max_time)
6426					l->max_time = age;
6427
6428				if (track->pid < l->min_pid)
6429					l->min_pid = track->pid;
6430				if (track->pid > l->max_pid)
6431					l->max_pid = track->pid;
6432
6433				cpumask_set_cpu(track->cpu,
6434						to_cpumask(l->cpus));
6435			}
6436			node_set(page_to_nid(virt_to_page(track)), l->nodes);
6437			return 1;
6438		}
6439
6440		if (track->addr < caddr)
6441			end = pos;
6442		else if (track->addr == caddr && handle < chandle)
6443			end = pos;
6444		else if (track->addr == caddr && handle == chandle &&
6445				waste < cwaste)
6446			end = pos;
6447		else
6448			start = pos;
6449	}
6450
6451	/*
6452	 * Not found. Insert new tracking element.
6453	 */
6454	if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
6455		return 0;
6456
6457	l = t->loc + pos;
6458	if (pos < t->count)
6459		memmove(l + 1, l,
6460			(t->count - pos) * sizeof(struct location));
6461	t->count++;
6462	l->count = 1;
6463	l->addr = track->addr;
6464	l->sum_time = age;
6465	l->min_time = age;
6466	l->max_time = age;
6467	l->min_pid = track->pid;
6468	l->max_pid = track->pid;
6469	l->handle = handle;
6470	l->waste = waste;
6471	cpumask_clear(to_cpumask(l->cpus));
6472	cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
6473	nodes_clear(l->nodes);
6474	node_set(page_to_nid(virt_to_page(track)), l->nodes);
6475	return 1;
6476}
6477
6478static void process_slab(struct loc_track *t, struct kmem_cache *s,
6479		struct slab *slab, enum track_item alloc,
6480		unsigned long *obj_map)
6481{
6482	void *addr = slab_address(slab);
6483	bool is_alloc = (alloc == TRACK_ALLOC);
6484	void *p;
6485
6486	__fill_map(obj_map, s, slab);
 
6487
6488	for_each_object(p, s, addr, slab->objects)
6489		if (!test_bit(__obj_to_index(s, addr, p), obj_map))
6490			add_location(t, s, get_track(s, p, alloc),
6491				     is_alloc ? get_orig_size(s, p) :
6492						s->object_size);
6493}
6494#endif  /* CONFIG_DEBUG_FS   */
6495#endif	/* CONFIG_SLUB_DEBUG */
6496
6497#ifdef SLAB_SUPPORTS_SYSFS
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6498enum slab_stat_type {
6499	SL_ALL,			/* All slabs */
6500	SL_PARTIAL,		/* Only partially allocated slabs */
6501	SL_CPU,			/* Only slabs used for cpu caches */
6502	SL_OBJECTS,		/* Determine allocated objects not slabs */
6503	SL_TOTAL		/* Determine object capacity not slabs */
6504};
6505
6506#define SO_ALL		(1 << SL_ALL)
6507#define SO_PARTIAL	(1 << SL_PARTIAL)
6508#define SO_CPU		(1 << SL_CPU)
6509#define SO_OBJECTS	(1 << SL_OBJECTS)
6510#define SO_TOTAL	(1 << SL_TOTAL)
6511
6512static ssize_t show_slab_objects(struct kmem_cache *s,
6513				 char *buf, unsigned long flags)
6514{
6515	unsigned long total = 0;
6516	int node;
6517	int x;
6518	unsigned long *nodes;
6519	int len = 0;
6520
6521	nodes = kcalloc(nr_node_ids, sizeof(unsigned long), GFP_KERNEL);
6522	if (!nodes)
6523		return -ENOMEM;
6524
6525	if (flags & SO_CPU) {
6526		int cpu;
6527
6528		for_each_possible_cpu(cpu) {
6529			struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab,
6530							       cpu);
6531			int node;
6532			struct slab *slab;
6533
6534			slab = READ_ONCE(c->slab);
6535			if (!slab)
6536				continue;
6537
6538			node = slab_nid(slab);
6539			if (flags & SO_TOTAL)
6540				x = slab->objects;
6541			else if (flags & SO_OBJECTS)
6542				x = slab->inuse;
6543			else
6544				x = 1;
6545
6546			total += x;
6547			nodes[node] += x;
6548
6549#ifdef CONFIG_SLUB_CPU_PARTIAL
6550			slab = slub_percpu_partial_read_once(c);
6551			if (slab) {
6552				node = slab_nid(slab);
6553				if (flags & SO_TOTAL)
6554					WARN_ON_ONCE(1);
6555				else if (flags & SO_OBJECTS)
6556					WARN_ON_ONCE(1);
6557				else
6558					x = data_race(slab->slabs);
6559				total += x;
6560				nodes[node] += x;
6561			}
6562#endif
6563		}
6564	}
6565
6566	/*
6567	 * It is impossible to take "mem_hotplug_lock" here with "kernfs_mutex"
6568	 * already held which will conflict with an existing lock order:
6569	 *
6570	 * mem_hotplug_lock->slab_mutex->kernfs_mutex
6571	 *
6572	 * We don't really need mem_hotplug_lock (to hold off
6573	 * slab_mem_going_offline_callback) here because slab's memory hot
6574	 * unplug code doesn't destroy the kmem_cache->node[] data.
6575	 */
6576
6577#ifdef CONFIG_SLUB_DEBUG
6578	if (flags & SO_ALL) {
6579		struct kmem_cache_node *n;
6580
6581		for_each_kmem_cache_node(s, node, n) {
6582
6583			if (flags & SO_TOTAL)
6584				x = node_nr_objs(n);
6585			else if (flags & SO_OBJECTS)
6586				x = node_nr_objs(n) - count_partial(n, count_free);
 
6587			else
6588				x = node_nr_slabs(n);
6589			total += x;
6590			nodes[node] += x;
6591		}
6592
6593	} else
6594#endif
6595	if (flags & SO_PARTIAL) {
6596		struct kmem_cache_node *n;
6597
6598		for_each_kmem_cache_node(s, node, n) {
6599			if (flags & SO_TOTAL)
6600				x = count_partial(n, count_total);
6601			else if (flags & SO_OBJECTS)
6602				x = count_partial(n, count_inuse);
6603			else
6604				x = n->nr_partial;
6605			total += x;
6606			nodes[node] += x;
6607		}
6608	}
6609
6610	len += sysfs_emit_at(buf, len, "%lu", total);
6611#ifdef CONFIG_NUMA
6612	for (node = 0; node < nr_node_ids; node++) {
6613		if (nodes[node])
6614			len += sysfs_emit_at(buf, len, " N%d=%lu",
6615					     node, nodes[node]);
6616	}
6617#endif
6618	len += sysfs_emit_at(buf, len, "\n");
6619	kfree(nodes);
 
 
6620
6621	return len;
 
 
 
 
 
 
 
 
 
 
6622}
 
6623
6624#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
6625#define to_slab(n) container_of(n, struct kmem_cache, kobj)
6626
6627struct slab_attribute {
6628	struct attribute attr;
6629	ssize_t (*show)(struct kmem_cache *s, char *buf);
6630	ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
6631};
6632
6633#define SLAB_ATTR_RO(_name) \
6634	static struct slab_attribute _name##_attr = __ATTR_RO_MODE(_name, 0400)
 
6635
6636#define SLAB_ATTR(_name) \
6637	static struct slab_attribute _name##_attr = __ATTR_RW_MODE(_name, 0600)
 
6638
6639static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
6640{
6641	return sysfs_emit(buf, "%u\n", s->size);
6642}
6643SLAB_ATTR_RO(slab_size);
6644
6645static ssize_t align_show(struct kmem_cache *s, char *buf)
6646{
6647	return sysfs_emit(buf, "%u\n", s->align);
6648}
6649SLAB_ATTR_RO(align);
6650
6651static ssize_t object_size_show(struct kmem_cache *s, char *buf)
6652{
6653	return sysfs_emit(buf, "%u\n", s->object_size);
6654}
6655SLAB_ATTR_RO(object_size);
6656
6657static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
6658{
6659	return sysfs_emit(buf, "%u\n", oo_objects(s->oo));
6660}
6661SLAB_ATTR_RO(objs_per_slab);
6662
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6663static ssize_t order_show(struct kmem_cache *s, char *buf)
6664{
6665	return sysfs_emit(buf, "%u\n", oo_order(s->oo));
6666}
6667SLAB_ATTR_RO(order);
6668
6669static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
6670{
6671	return sysfs_emit(buf, "%lu\n", s->min_partial);
6672}
6673
6674static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
6675				 size_t length)
6676{
6677	unsigned long min;
6678	int err;
6679
6680	err = kstrtoul(buf, 10, &min);
6681	if (err)
6682		return err;
6683
6684	s->min_partial = min;
6685	return length;
6686}
6687SLAB_ATTR(min_partial);
6688
6689static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
6690{
6691	unsigned int nr_partial = 0;
6692#ifdef CONFIG_SLUB_CPU_PARTIAL
6693	nr_partial = s->cpu_partial;
6694#endif
6695
6696	return sysfs_emit(buf, "%u\n", nr_partial);
6697}
6698
6699static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
6700				 size_t length)
6701{
6702	unsigned int objects;
6703	int err;
6704
6705	err = kstrtouint(buf, 10, &objects);
6706	if (err)
6707		return err;
6708	if (objects && !kmem_cache_has_cpu_partial(s))
6709		return -EINVAL;
6710
6711	slub_set_cpu_partial(s, objects);
6712	flush_all(s);
6713	return length;
6714}
6715SLAB_ATTR(cpu_partial);
6716
6717static ssize_t ctor_show(struct kmem_cache *s, char *buf)
6718{
6719	if (!s->ctor)
6720		return 0;
6721	return sysfs_emit(buf, "%pS\n", s->ctor);
6722}
6723SLAB_ATTR_RO(ctor);
6724
6725static ssize_t aliases_show(struct kmem_cache *s, char *buf)
6726{
6727	return sysfs_emit(buf, "%d\n", s->refcount < 0 ? 0 : s->refcount - 1);
6728}
6729SLAB_ATTR_RO(aliases);
6730
6731static ssize_t partial_show(struct kmem_cache *s, char *buf)
6732{
6733	return show_slab_objects(s, buf, SO_PARTIAL);
6734}
6735SLAB_ATTR_RO(partial);
6736
6737static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
6738{
6739	return show_slab_objects(s, buf, SO_CPU);
6740}
6741SLAB_ATTR_RO(cpu_slabs);
6742
 
 
 
 
 
 
6743static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
6744{
6745	return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
6746}
6747SLAB_ATTR_RO(objects_partial);
6748
6749static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
6750{
6751	int objects = 0;
6752	int slabs = 0;
6753	int cpu __maybe_unused;
6754	int len = 0;
6755
6756#ifdef CONFIG_SLUB_CPU_PARTIAL
6757	for_each_online_cpu(cpu) {
6758		struct slab *slab;
6759
6760		slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu));
6761
6762		if (slab)
6763			slabs += data_race(slab->slabs);
6764	}
6765#endif
6766
6767	/* Approximate half-full slabs, see slub_set_cpu_partial() */
6768	objects = (slabs * oo_objects(s->oo)) / 2;
6769	len += sysfs_emit_at(buf, len, "%d(%d)", objects, slabs);
6770
6771#ifdef CONFIG_SLUB_CPU_PARTIAL
6772	for_each_online_cpu(cpu) {
6773		struct slab *slab;
6774
6775		slab = slub_percpu_partial(per_cpu_ptr(s->cpu_slab, cpu));
6776		if (slab) {
6777			slabs = data_race(slab->slabs);
6778			objects = (slabs * oo_objects(s->oo)) / 2;
6779			len += sysfs_emit_at(buf, len, " C%d=%d(%d)",
6780					     cpu, objects, slabs);
6781		}
6782	}
6783#endif
6784	len += sysfs_emit_at(buf, len, "\n");
6785
6786	return len;
6787}
6788SLAB_ATTR_RO(slabs_cpu_partial);
6789
6790static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
6791{
6792	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
6793}
6794SLAB_ATTR_RO(reclaim_account);
 
 
 
 
 
 
 
 
 
6795
6796static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
6797{
6798	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
6799}
6800SLAB_ATTR_RO(hwcache_align);
6801
6802#ifdef CONFIG_ZONE_DMA
6803static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
6804{
6805	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
6806}
6807SLAB_ATTR_RO(cache_dma);
6808#endif
6809
6810#ifdef CONFIG_HARDENED_USERCOPY
6811static ssize_t usersize_show(struct kmem_cache *s, char *buf)
6812{
6813	return sysfs_emit(buf, "%u\n", s->usersize);
6814}
6815SLAB_ATTR_RO(usersize);
6816#endif
6817
6818static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
6819{
6820	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TYPESAFE_BY_RCU));
6821}
6822SLAB_ATTR_RO(destroy_by_rcu);
6823
6824#ifdef CONFIG_SLUB_DEBUG
6825static ssize_t slabs_show(struct kmem_cache *s, char *buf)
6826{
6827	return show_slab_objects(s, buf, SO_ALL);
6828}
6829SLAB_ATTR_RO(slabs);
6830
6831static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
6832{
6833	return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
6834}
6835SLAB_ATTR_RO(total_objects);
6836
6837static ssize_t objects_show(struct kmem_cache *s, char *buf)
6838{
6839	return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
6840}
6841SLAB_ATTR_RO(objects);
6842
6843static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
 
6844{
6845	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_CONSISTENCY_CHECKS));
 
 
 
 
 
6846}
6847SLAB_ATTR_RO(sanity_checks);
6848
6849static ssize_t trace_show(struct kmem_cache *s, char *buf)
6850{
6851	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_TRACE));
6852}
6853SLAB_ATTR_RO(trace);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6854
6855static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
6856{
6857	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
6858}
6859
6860SLAB_ATTR_RO(red_zone);
 
 
 
 
 
 
 
 
 
 
 
 
 
6861
6862static ssize_t poison_show(struct kmem_cache *s, char *buf)
6863{
6864	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_POISON));
6865}
6866
6867SLAB_ATTR_RO(poison);
 
 
 
 
 
 
 
 
 
 
 
 
 
6868
6869static ssize_t store_user_show(struct kmem_cache *s, char *buf)
6870{
6871	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
6872}
6873
6874SLAB_ATTR_RO(store_user);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6875
6876static ssize_t validate_show(struct kmem_cache *s, char *buf)
6877{
6878	return 0;
6879}
6880
6881static ssize_t validate_store(struct kmem_cache *s,
6882			const char *buf, size_t length)
6883{
6884	int ret = -EINVAL;
6885
6886	if (buf[0] == '1' && kmem_cache_debug(s)) {
6887		ret = validate_slab_cache(s);
6888		if (ret >= 0)
6889			ret = length;
6890	}
6891	return ret;
6892}
6893SLAB_ATTR(validate);
6894
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
6895#endif /* CONFIG_SLUB_DEBUG */
6896
6897#ifdef CONFIG_FAILSLAB
6898static ssize_t failslab_show(struct kmem_cache *s, char *buf)
6899{
6900	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
6901}
6902
6903static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
6904				size_t length)
6905{
6906	if (s->refcount > 1)
6907		return -EINVAL;
6908
 
6909	if (buf[0] == '1')
6910		WRITE_ONCE(s->flags, s->flags | SLAB_FAILSLAB);
6911	else
6912		WRITE_ONCE(s->flags, s->flags & ~SLAB_FAILSLAB);
6913
6914	return length;
6915}
6916SLAB_ATTR(failslab);
6917#endif
6918
6919static ssize_t shrink_show(struct kmem_cache *s, char *buf)
6920{
6921	return 0;
6922}
6923
6924static ssize_t shrink_store(struct kmem_cache *s,
6925			const char *buf, size_t length)
6926{
6927	if (buf[0] == '1')
6928		kmem_cache_shrink(s);
6929	else
6930		return -EINVAL;
6931	return length;
6932}
6933SLAB_ATTR(shrink);
6934
6935#ifdef CONFIG_NUMA
6936static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
6937{
6938	return sysfs_emit(buf, "%u\n", s->remote_node_defrag_ratio / 10);
6939}
6940
6941static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
6942				const char *buf, size_t length)
6943{
6944	unsigned int ratio;
6945	int err;
6946
6947	err = kstrtouint(buf, 10, &ratio);
6948	if (err)
6949		return err;
6950	if (ratio > 100)
6951		return -ERANGE;
6952
6953	s->remote_node_defrag_ratio = ratio * 10;
 
6954
6955	return length;
6956}
6957SLAB_ATTR(remote_node_defrag_ratio);
6958#endif
6959
6960#ifdef CONFIG_SLUB_STATS
6961static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
6962{
6963	unsigned long sum  = 0;
6964	int cpu;
6965	int len = 0;
6966	int *data = kmalloc_array(nr_cpu_ids, sizeof(int), GFP_KERNEL);
6967
6968	if (!data)
6969		return -ENOMEM;
6970
6971	for_each_online_cpu(cpu) {
6972		unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
6973
6974		data[cpu] = x;
6975		sum += x;
6976	}
6977
6978	len += sysfs_emit_at(buf, len, "%lu", sum);
6979
6980#ifdef CONFIG_SMP
6981	for_each_online_cpu(cpu) {
6982		if (data[cpu])
6983			len += sysfs_emit_at(buf, len, " C%d=%u",
6984					     cpu, data[cpu]);
6985	}
6986#endif
6987	kfree(data);
6988	len += sysfs_emit_at(buf, len, "\n");
6989
6990	return len;
6991}
6992
6993static void clear_stat(struct kmem_cache *s, enum stat_item si)
6994{
6995	int cpu;
6996
6997	for_each_online_cpu(cpu)
6998		per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
6999}
7000
7001#define STAT_ATTR(si, text) 					\
7002static ssize_t text##_show(struct kmem_cache *s, char *buf)	\
7003{								\
7004	return show_stat(s, buf, si);				\
7005}								\
7006static ssize_t text##_store(struct kmem_cache *s,		\
7007				const char *buf, size_t length)	\
7008{								\
7009	if (buf[0] != '0')					\
7010		return -EINVAL;					\
7011	clear_stat(s, si);					\
7012	return length;						\
7013}								\
7014SLAB_ATTR(text);						\
7015
7016STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
7017STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
7018STAT_ATTR(FREE_FASTPATH, free_fastpath);
7019STAT_ATTR(FREE_SLOWPATH, free_slowpath);
7020STAT_ATTR(FREE_FROZEN, free_frozen);
7021STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
7022STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
7023STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
7024STAT_ATTR(ALLOC_SLAB, alloc_slab);
7025STAT_ATTR(ALLOC_REFILL, alloc_refill);
7026STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch);
7027STAT_ATTR(FREE_SLAB, free_slab);
7028STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
7029STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
7030STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
7031STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
7032STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
7033STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
7034STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass);
7035STAT_ATTR(ORDER_FALLBACK, order_fallback);
7036STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
7037STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
7038STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc);
7039STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);
7040STAT_ATTR(CPU_PARTIAL_NODE, cpu_partial_node);
7041STAT_ATTR(CPU_PARTIAL_DRAIN, cpu_partial_drain);
7042#endif	/* CONFIG_SLUB_STATS */
7043
7044#ifdef CONFIG_KFENCE
7045static ssize_t skip_kfence_show(struct kmem_cache *s, char *buf)
7046{
7047	return sysfs_emit(buf, "%d\n", !!(s->flags & SLAB_SKIP_KFENCE));
7048}
7049
7050static ssize_t skip_kfence_store(struct kmem_cache *s,
7051			const char *buf, size_t length)
7052{
7053	int ret = length;
7054
7055	if (buf[0] == '0')
7056		s->flags &= ~SLAB_SKIP_KFENCE;
7057	else if (buf[0] == '1')
7058		s->flags |= SLAB_SKIP_KFENCE;
7059	else
7060		ret = -EINVAL;
7061
7062	return ret;
7063}
7064SLAB_ATTR(skip_kfence);
7065#endif
7066
7067static struct attribute *slab_attrs[] = {
7068	&slab_size_attr.attr,
7069	&object_size_attr.attr,
7070	&objs_per_slab_attr.attr,
7071	&order_attr.attr,
7072	&min_partial_attr.attr,
7073	&cpu_partial_attr.attr,
 
7074	&objects_partial_attr.attr,
7075	&partial_attr.attr,
7076	&cpu_slabs_attr.attr,
7077	&ctor_attr.attr,
7078	&aliases_attr.attr,
7079	&align_attr.attr,
7080	&hwcache_align_attr.attr,
7081	&reclaim_account_attr.attr,
7082	&destroy_by_rcu_attr.attr,
7083	&shrink_attr.attr,
 
7084	&slabs_cpu_partial_attr.attr,
7085#ifdef CONFIG_SLUB_DEBUG
7086	&total_objects_attr.attr,
7087	&objects_attr.attr,
7088	&slabs_attr.attr,
7089	&sanity_checks_attr.attr,
7090	&trace_attr.attr,
7091	&red_zone_attr.attr,
7092	&poison_attr.attr,
7093	&store_user_attr.attr,
7094	&validate_attr.attr,
 
 
7095#endif
7096#ifdef CONFIG_ZONE_DMA
7097	&cache_dma_attr.attr,
7098#endif
7099#ifdef CONFIG_NUMA
7100	&remote_node_defrag_ratio_attr.attr,
7101#endif
7102#ifdef CONFIG_SLUB_STATS
7103	&alloc_fastpath_attr.attr,
7104	&alloc_slowpath_attr.attr,
7105	&free_fastpath_attr.attr,
7106	&free_slowpath_attr.attr,
7107	&free_frozen_attr.attr,
7108	&free_add_partial_attr.attr,
7109	&free_remove_partial_attr.attr,
7110	&alloc_from_partial_attr.attr,
7111	&alloc_slab_attr.attr,
7112	&alloc_refill_attr.attr,
7113	&alloc_node_mismatch_attr.attr,
7114	&free_slab_attr.attr,
7115	&cpuslab_flush_attr.attr,
7116	&deactivate_full_attr.attr,
7117	&deactivate_empty_attr.attr,
7118	&deactivate_to_head_attr.attr,
7119	&deactivate_to_tail_attr.attr,
7120	&deactivate_remote_frees_attr.attr,
7121	&deactivate_bypass_attr.attr,
7122	&order_fallback_attr.attr,
7123	&cmpxchg_double_fail_attr.attr,
7124	&cmpxchg_double_cpu_fail_attr.attr,
7125	&cpu_partial_alloc_attr.attr,
7126	&cpu_partial_free_attr.attr,
7127	&cpu_partial_node_attr.attr,
7128	&cpu_partial_drain_attr.attr,
7129#endif
7130#ifdef CONFIG_FAILSLAB
7131	&failslab_attr.attr,
7132#endif
7133#ifdef CONFIG_HARDENED_USERCOPY
7134	&usersize_attr.attr,
7135#endif
7136#ifdef CONFIG_KFENCE
7137	&skip_kfence_attr.attr,
7138#endif
7139
7140	NULL
7141};
7142
7143static const struct attribute_group slab_attr_group = {
7144	.attrs = slab_attrs,
7145};
7146
7147static ssize_t slab_attr_show(struct kobject *kobj,
7148				struct attribute *attr,
7149				char *buf)
7150{
7151	struct slab_attribute *attribute;
7152	struct kmem_cache *s;
 
7153
7154	attribute = to_slab_attr(attr);
7155	s = to_slab(kobj);
7156
7157	if (!attribute->show)
7158		return -EIO;
7159
7160	return attribute->show(s, buf);
 
 
7161}
7162
7163static ssize_t slab_attr_store(struct kobject *kobj,
7164				struct attribute *attr,
7165				const char *buf, size_t len)
7166{
7167	struct slab_attribute *attribute;
7168	struct kmem_cache *s;
 
7169
7170	attribute = to_slab_attr(attr);
7171	s = to_slab(kobj);
7172
7173	if (!attribute->store)
7174		return -EIO;
7175
7176	return attribute->store(s, buf, len);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
7177}
7178
7179static void kmem_cache_release(struct kobject *k)
7180{
7181	slab_kmem_cache_release(to_slab(k));
7182}
7183
7184static const struct sysfs_ops slab_sysfs_ops = {
7185	.show = slab_attr_show,
7186	.store = slab_attr_store,
7187};
7188
7189static const struct kobj_type slab_ktype = {
7190	.sysfs_ops = &slab_sysfs_ops,
7191	.release = kmem_cache_release,
7192};
7193
 
 
 
 
 
 
 
 
 
 
 
 
 
7194static struct kset *slab_kset;
7195
7196static inline struct kset *cache_kset(struct kmem_cache *s)
7197{
 
 
 
 
7198	return slab_kset;
7199}
7200
7201#define ID_STR_LENGTH 32
7202
7203/* Create a unique string id for a slab cache:
7204 *
7205 * Format	:[flags-]size
7206 */
7207static char *create_unique_id(struct kmem_cache *s)
7208{
7209	char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
7210	char *p = name;
7211
7212	if (!name)
7213		return ERR_PTR(-ENOMEM);
7214
7215	*p++ = ':';
7216	/*
7217	 * First flags affecting slabcache operations. We will only
7218	 * get here for aliasable slabs so we do not need to support
7219	 * too many flags. The flags here must cover all flags that
7220	 * are matched during merging to guarantee that the id is
7221	 * unique.
7222	 */
7223	if (s->flags & SLAB_CACHE_DMA)
7224		*p++ = 'd';
7225	if (s->flags & SLAB_CACHE_DMA32)
7226		*p++ = 'D';
7227	if (s->flags & SLAB_RECLAIM_ACCOUNT)
7228		*p++ = 'a';
7229	if (s->flags & SLAB_CONSISTENCY_CHECKS)
7230		*p++ = 'F';
 
 
7231	if (s->flags & SLAB_ACCOUNT)
7232		*p++ = 'A';
7233	if (p != name + 1)
7234		*p++ = '-';
7235	p += snprintf(p, ID_STR_LENGTH - (p - name), "%07u", s->size);
7236
7237	if (WARN_ON(p > name + ID_STR_LENGTH - 1)) {
7238		kfree(name);
7239		return ERR_PTR(-EINVAL);
7240	}
7241	kmsan_unpoison_memory(name, p - name);
7242	return name;
7243}
7244
7245static int sysfs_slab_add(struct kmem_cache *s)
7246{
7247	int err;
7248	const char *name;
7249	struct kset *kset = cache_kset(s);
7250	int unmergeable = slab_unmergeable(s);
7251
7252	if (!unmergeable && disable_higher_order_debug &&
7253			(slub_debug & DEBUG_METADATA_FLAGS))
7254		unmergeable = 1;
7255
7256	if (unmergeable) {
7257		/*
7258		 * Slabcache can never be merged so we can use the name proper.
7259		 * This is typically the case for debug situations. In that
7260		 * case we can catch duplicate names easily.
7261		 */
7262		sysfs_remove_link(&slab_kset->kobj, s->name);
7263		name = s->name;
7264	} else {
7265		/*
7266		 * Create a unique name for the slab as a target
7267		 * for the symlinks.
7268		 */
7269		name = create_unique_id(s);
7270		if (IS_ERR(name))
7271			return PTR_ERR(name);
7272	}
7273
7274	s->kobj.kset = kset;
7275	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
7276	if (err)
7277		goto out;
7278
7279	err = sysfs_create_group(&s->kobj, &slab_attr_group);
7280	if (err)
7281		goto out_del_kobj;
7282
 
 
 
 
 
 
 
 
 
 
 
7283	if (!unmergeable) {
7284		/* Setup first alias */
7285		sysfs_slab_alias(s, s->name);
7286	}
7287out:
7288	if (!unmergeable)
7289		kfree(name);
7290	return err;
7291out_del_kobj:
7292	kobject_del(&s->kobj);
7293	goto out;
7294}
7295
7296void sysfs_slab_unlink(struct kmem_cache *s)
7297{
7298	if (s->kobj.state_in_sysfs)
7299		kobject_del(&s->kobj);
7300}
 
 
 
7301
7302void sysfs_slab_release(struct kmem_cache *s)
7303{
 
 
 
7304	kobject_put(&s->kobj);
7305}
7306
7307/*
7308 * Need to buffer aliases during bootup until sysfs becomes
7309 * available lest we lose that information.
7310 */
7311struct saved_alias {
7312	struct kmem_cache *s;
7313	const char *name;
7314	struct saved_alias *next;
7315};
7316
7317static struct saved_alias *alias_list;
7318
7319static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
7320{
7321	struct saved_alias *al;
7322
7323	if (slab_state == FULL) {
7324		/*
7325		 * If we have a leftover link then remove it.
7326		 */
7327		sysfs_remove_link(&slab_kset->kobj, name);
7328		/*
7329		 * The original cache may have failed to generate sysfs file.
7330		 * In that case, sysfs_create_link() returns -ENOENT and
7331		 * symbolic link creation is skipped.
7332		 */
7333		return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
7334	}
7335
7336	al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
7337	if (!al)
7338		return -ENOMEM;
7339
7340	al->s = s;
7341	al->name = name;
7342	al->next = alias_list;
7343	alias_list = al;
7344	kmsan_unpoison_memory(al, sizeof(*al));
7345	return 0;
7346}
7347
7348static int __init slab_sysfs_init(void)
7349{
7350	struct kmem_cache *s;
7351	int err;
7352
7353	mutex_lock(&slab_mutex);
7354
7355	slab_kset = kset_create_and_add("slab", NULL, kernel_kobj);
7356	if (!slab_kset) {
7357		mutex_unlock(&slab_mutex);
7358		pr_err("Cannot register slab subsystem.\n");
7359		return -ENOMEM;
7360	}
7361
7362	slab_state = FULL;
7363
7364	list_for_each_entry(s, &slab_caches, list) {
7365		err = sysfs_slab_add(s);
7366		if (err)
7367			pr_err("SLUB: Unable to add boot slab %s to sysfs\n",
7368			       s->name);
7369	}
7370
7371	while (alias_list) {
7372		struct saved_alias *al = alias_list;
7373
7374		alias_list = alias_list->next;
7375		err = sysfs_slab_alias(al->s, al->name);
7376		if (err)
7377			pr_err("SLUB: Unable to add boot slab alias %s to sysfs\n",
7378			       al->name);
7379		kfree(al);
7380	}
7381
7382	mutex_unlock(&slab_mutex);
 
7383	return 0;
7384}
7385late_initcall(slab_sysfs_init);
7386#endif /* SLAB_SUPPORTS_SYSFS */
7387
7388#if defined(CONFIG_SLUB_DEBUG) && defined(CONFIG_DEBUG_FS)
7389static int slab_debugfs_show(struct seq_file *seq, void *v)
7390{
7391	struct loc_track *t = seq->private;
7392	struct location *l;
7393	unsigned long idx;
7394
7395	idx = (unsigned long) t->idx;
7396	if (idx < t->count) {
7397		l = &t->loc[idx];
7398
7399		seq_printf(seq, "%7ld ", l->count);
7400
7401		if (l->addr)
7402			seq_printf(seq, "%pS", (void *)l->addr);
7403		else
7404			seq_puts(seq, "<not-available>");
7405
7406		if (l->waste)
7407			seq_printf(seq, " waste=%lu/%lu",
7408				l->count * l->waste, l->waste);
7409
7410		if (l->sum_time != l->min_time) {
7411			seq_printf(seq, " age=%ld/%llu/%ld",
7412				l->min_time, div_u64(l->sum_time, l->count),
7413				l->max_time);
7414		} else
7415			seq_printf(seq, " age=%ld", l->min_time);
7416
7417		if (l->min_pid != l->max_pid)
7418			seq_printf(seq, " pid=%ld-%ld", l->min_pid, l->max_pid);
7419		else
7420			seq_printf(seq, " pid=%ld",
7421				l->min_pid);
7422
7423		if (num_online_cpus() > 1 && !cpumask_empty(to_cpumask(l->cpus)))
7424			seq_printf(seq, " cpus=%*pbl",
7425				 cpumask_pr_args(to_cpumask(l->cpus)));
7426
7427		if (nr_online_nodes > 1 && !nodes_empty(l->nodes))
7428			seq_printf(seq, " nodes=%*pbl",
7429				 nodemask_pr_args(&l->nodes));
7430
7431#ifdef CONFIG_STACKDEPOT
7432		{
7433			depot_stack_handle_t handle;
7434			unsigned long *entries;
7435			unsigned int nr_entries, j;
7436
7437			handle = READ_ONCE(l->handle);
7438			if (handle) {
7439				nr_entries = stack_depot_fetch(handle, &entries);
7440				seq_puts(seq, "\n");
7441				for (j = 0; j < nr_entries; j++)
7442					seq_printf(seq, "        %pS\n", (void *)entries[j]);
7443			}
7444		}
7445#endif
7446		seq_puts(seq, "\n");
7447	}
7448
7449	if (!idx && !t->count)
7450		seq_puts(seq, "No data\n");
7451
7452	return 0;
7453}
7454
7455static void slab_debugfs_stop(struct seq_file *seq, void *v)
7456{
7457}
7458
7459static void *slab_debugfs_next(struct seq_file *seq, void *v, loff_t *ppos)
7460{
7461	struct loc_track *t = seq->private;
7462
7463	t->idx = ++(*ppos);
7464	if (*ppos <= t->count)
7465		return ppos;
7466
7467	return NULL;
7468}
7469
7470static int cmp_loc_by_count(const void *a, const void *b, const void *data)
7471{
7472	struct location *loc1 = (struct location *)a;
7473	struct location *loc2 = (struct location *)b;
7474
7475	if (loc1->count > loc2->count)
7476		return -1;
7477	else
7478		return 1;
7479}
7480
7481static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos)
7482{
7483	struct loc_track *t = seq->private;
7484
7485	t->idx = *ppos;
7486	return ppos;
7487}
7488
7489static const struct seq_operations slab_debugfs_sops = {
7490	.start  = slab_debugfs_start,
7491	.next   = slab_debugfs_next,
7492	.stop   = slab_debugfs_stop,
7493	.show   = slab_debugfs_show,
7494};
7495
7496static int slab_debug_trace_open(struct inode *inode, struct file *filep)
7497{
7498
7499	struct kmem_cache_node *n;
7500	enum track_item alloc;
7501	int node;
7502	struct loc_track *t = __seq_open_private(filep, &slab_debugfs_sops,
7503						sizeof(struct loc_track));
7504	struct kmem_cache *s = file_inode(filep)->i_private;
7505	unsigned long *obj_map;
7506
7507	if (!t)
7508		return -ENOMEM;
7509
7510	obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
7511	if (!obj_map) {
7512		seq_release_private(inode, filep);
7513		return -ENOMEM;
7514	}
7515
7516	if (strcmp(filep->f_path.dentry->d_name.name, "alloc_traces") == 0)
7517		alloc = TRACK_ALLOC;
7518	else
7519		alloc = TRACK_FREE;
7520
7521	if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL)) {
7522		bitmap_free(obj_map);
7523		seq_release_private(inode, filep);
7524		return -ENOMEM;
7525	}
7526
7527	for_each_kmem_cache_node(s, node, n) {
7528		unsigned long flags;
7529		struct slab *slab;
7530
7531		if (!node_nr_slabs(n))
7532			continue;
7533
7534		spin_lock_irqsave(&n->list_lock, flags);
7535		list_for_each_entry(slab, &n->partial, slab_list)
7536			process_slab(t, s, slab, alloc, obj_map);
7537		list_for_each_entry(slab, &n->full, slab_list)
7538			process_slab(t, s, slab, alloc, obj_map);
7539		spin_unlock_irqrestore(&n->list_lock, flags);
7540	}
7541
7542	/* Sort locations by count */
7543	sort_r(t->loc, t->count, sizeof(struct location),
7544		cmp_loc_by_count, NULL, NULL);
7545
7546	bitmap_free(obj_map);
7547	return 0;
7548}
7549
7550static int slab_debug_trace_release(struct inode *inode, struct file *file)
7551{
7552	struct seq_file *seq = file->private_data;
7553	struct loc_track *t = seq->private;
7554
7555	free_loc_track(t);
7556	return seq_release_private(inode, file);
7557}
7558
7559static const struct file_operations slab_debugfs_fops = {
7560	.open    = slab_debug_trace_open,
7561	.read    = seq_read,
7562	.llseek  = seq_lseek,
7563	.release = slab_debug_trace_release,
7564};
7565
7566static void debugfs_slab_add(struct kmem_cache *s)
7567{
7568	struct dentry *slab_cache_dir;
7569
7570	if (unlikely(!slab_debugfs_root))
7571		return;
7572
7573	slab_cache_dir = debugfs_create_dir(s->name, slab_debugfs_root);
7574
7575	debugfs_create_file("alloc_traces", 0400,
7576		slab_cache_dir, s, &slab_debugfs_fops);
7577
7578	debugfs_create_file("free_traces", 0400,
7579		slab_cache_dir, s, &slab_debugfs_fops);
7580}
7581
7582void debugfs_slab_release(struct kmem_cache *s)
7583{
7584	debugfs_lookup_and_remove(s->name, slab_debugfs_root);
7585}
7586
7587static int __init slab_debugfs_init(void)
7588{
7589	struct kmem_cache *s;
7590
7591	slab_debugfs_root = debugfs_create_dir("slab", NULL);
7592
7593	list_for_each_entry(s, &slab_caches, list)
7594		if (s->flags & SLAB_STORE_USER)
7595			debugfs_slab_add(s);
7596
7597	return 0;
7598
7599}
7600__initcall(slab_debugfs_init);
7601#endif
7602/*
7603 * The /proc/slabinfo ABI
7604 */
7605#ifdef CONFIG_SLUB_DEBUG
7606void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo)
7607{
7608	unsigned long nr_slabs = 0;
7609	unsigned long nr_objs = 0;
7610	unsigned long nr_free = 0;
7611	int node;
7612	struct kmem_cache_node *n;
7613
7614	for_each_kmem_cache_node(s, node, n) {
7615		nr_slabs += node_nr_slabs(n);
7616		nr_objs += node_nr_objs(n);
7617		nr_free += count_partial_free_approx(n);
7618	}
7619
7620	sinfo->active_objs = nr_objs - nr_free;
7621	sinfo->num_objs = nr_objs;
7622	sinfo->active_slabs = nr_slabs;
7623	sinfo->num_slabs = nr_slabs;
7624	sinfo->objects_per_slab = oo_objects(s->oo);
7625	sinfo->cache_order = oo_order(s->oo);
7626}
7627#endif /* CONFIG_SLUB_DEBUG */