linux/mm/slab_common.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Slab allocator functions that are independent of the allocator strategy
   4 *
   5 * (C) 2012 Christoph Lameter <cl@linux.com>
   6 */
   7#include <linux/slab.h>
   8
   9#include <linux/mm.h>
  10#include <linux/poison.h>
  11#include <linux/interrupt.h>
  12#include <linux/memory.h>
  13#include <linux/cache.h>
  14#include <linux/compiler.h>
  15#include <linux/kfence.h>
  16#include <linux/module.h>
  17#include <linux/cpu.h>
  18#include <linux/uaccess.h>
  19#include <linux/seq_file.h>
  20#include <linux/proc_fs.h>
  21#include <linux/debugfs.h>
  22#include <linux/kasan.h>
  23#include <asm/cacheflush.h>
  24#include <asm/tlbflush.h>
  25#include <asm/page.h>
  26#include <linux/memcontrol.h>
  27
  28#define CREATE_TRACE_POINTS
  29#include <trace/events/kmem.h>
  30
  31#include "internal.h"
  32
  33#include "slab.h"
  34
  35enum slab_state slab_state;
  36LIST_HEAD(slab_caches);
  37DEFINE_MUTEX(slab_mutex);
  38struct kmem_cache *kmem_cache;
  39
  40#ifdef CONFIG_HARDENED_USERCOPY
  41bool usercopy_fallback __ro_after_init =
  42                IS_ENABLED(CONFIG_HARDENED_USERCOPY_FALLBACK);
  43module_param(usercopy_fallback, bool, 0400);
  44MODULE_PARM_DESC(usercopy_fallback,
  45                "WARN instead of reject usercopy whitelist violations");
  46#endif
  47
  48static LIST_HEAD(slab_caches_to_rcu_destroy);
  49static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work);
  50static DECLARE_WORK(slab_caches_to_rcu_destroy_work,
  51                    slab_caches_to_rcu_destroy_workfn);
  52
  53/*
  54 * Set of flags that will prevent slab merging
  55 */
  56#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
  57                SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \
  58                SLAB_FAILSLAB | kasan_never_merge())
  59
  60#define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
  61                         SLAB_CACHE_DMA32 | SLAB_ACCOUNT)
  62
  63/*
  64 * Merge control. If this is set then no merging of slab caches will occur.
  65 */
  66static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT);
  67
  68static int __init setup_slab_nomerge(char *str)
  69{
  70        slab_nomerge = true;
  71        return 1;
  72}
  73
  74static int __init setup_slab_merge(char *str)
  75{
  76        slab_nomerge = false;
  77        return 1;
  78}
  79
  80#ifdef CONFIG_SLUB
  81__setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0);
  82__setup_param("slub_merge", slub_merge, setup_slab_merge, 0);
  83#endif
  84
  85__setup("slab_nomerge", setup_slab_nomerge);
  86__setup("slab_merge", setup_slab_merge);
  87
  88/*
  89 * Determine the size of a slab object
  90 */
  91unsigned int kmem_cache_size(struct kmem_cache *s)
  92{
  93        return s->object_size;
  94}
  95EXPORT_SYMBOL(kmem_cache_size);
  96
  97#ifdef CONFIG_DEBUG_VM
  98static int kmem_cache_sanity_check(const char *name, unsigned int size)
  99{
 100        if (!name || in_interrupt() || size > KMALLOC_MAX_SIZE) {
 101                pr_err("kmem_cache_create(%s) integrity check failed\n", name);
 102                return -EINVAL;
 103        }
 104
 105        WARN_ON(strchr(name, ' '));     /* It confuses parsers */
 106        return 0;
 107}
 108#else
 109static inline int kmem_cache_sanity_check(const char *name, unsigned int size)
 110{
 111        return 0;
 112}
 113#endif
 114
 115void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p)
 116{
 117        size_t i;
 118
 119        for (i = 0; i < nr; i++) {
 120                if (s)
 121                        kmem_cache_free(s, p[i]);
 122                else
 123                        kfree(p[i]);
 124        }
 125}
 126
 127int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr,
 128                                                                void **p)
 129{
 130        size_t i;
 131
 132        for (i = 0; i < nr; i++) {
 133                void *x = p[i] = kmem_cache_alloc(s, flags);
 134                if (!x) {
 135                        __kmem_cache_free_bulk(s, i, p);
 136                        return 0;
 137                }
 138        }
 139        return i;
 140}
 141
 142/*
 143 * Figure out what the alignment of the objects will be given a set of
 144 * flags, a user specified alignment and the size of the objects.
 145 */
 146static unsigned int calculate_alignment(slab_flags_t flags,
 147                unsigned int align, unsigned int size)
 148{
 149        /*
 150         * If the user wants hardware cache aligned objects then follow that
 151         * suggestion if the object is sufficiently large.
 152         *
 153         * The hardware cache alignment cannot override the specified
 154         * alignment though. If that is greater then use it.
 155         */
 156        if (flags & SLAB_HWCACHE_ALIGN) {
 157                unsigned int ralign;
 158
 159                ralign = cache_line_size();
 160                while (size <= ralign / 2)
 161                        ralign /= 2;
 162                align = max(align, ralign);
 163        }
 164
 165        if (align < ARCH_SLAB_MINALIGN)
 166                align = ARCH_SLAB_MINALIGN;
 167
 168        return ALIGN(align, sizeof(void *));
 169}
 170
 171/*
 172 * Find a mergeable slab cache
 173 */
 174int slab_unmergeable(struct kmem_cache *s)
 175{
 176        if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE))
 177                return 1;
 178
 179        if (s->ctor)
 180                return 1;
 181
 182        if (s->usersize)
 183                return 1;
 184
 185        /*
 186         * We may have set a slab to be unmergeable during bootstrap.
 187         */
 188        if (s->refcount < 0)
 189                return 1;
 190
 191        return 0;
 192}
 193
 194struct kmem_cache *find_mergeable(unsigned int size, unsigned int align,
 195                slab_flags_t flags, const char *name, void (*ctor)(void *))
 196{
 197        struct kmem_cache *s;
 198
 199        if (slab_nomerge)
 200                return NULL;
 201
 202        if (ctor)
 203                return NULL;
 204
 205        size = ALIGN(size, sizeof(void *));
 206        align = calculate_alignment(flags, align, size);
 207        size = ALIGN(size, align);
 208        flags = kmem_cache_flags(size, flags, name);
 209
 210        if (flags & SLAB_NEVER_MERGE)
 211                return NULL;
 212
 213        list_for_each_entry_reverse(s, &slab_caches, list) {
 214                if (slab_unmergeable(s))
 215                        continue;
 216
 217                if (size > s->size)
 218                        continue;
 219
 220                if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME))
 221                        continue;
 222                /*
 223                 * Check if alignment is compatible.
 224                 * Courtesy of Adrian Drzewiecki
 225                 */
 226                if ((s->size & ~(align - 1)) != s->size)
 227                        continue;
 228
 229                if (s->size - size >= sizeof(void *))
 230                        continue;
 231
 232                if (IS_ENABLED(CONFIG_SLAB) && align &&
 233                        (align > s->align || s->align % align))
 234                        continue;
 235
 236                return s;
 237        }
 238        return NULL;
 239}
 240
 241static struct kmem_cache *create_cache(const char *name,
 242                unsigned int object_size, unsigned int align,
 243                slab_flags_t flags, unsigned int useroffset,
 244                unsigned int usersize, void (*ctor)(void *),
 245                struct kmem_cache *root_cache)
 246{
 247        struct kmem_cache *s;
 248        int err;
 249
 250        if (WARN_ON(useroffset + usersize > object_size))
 251                useroffset = usersize = 0;
 252
 253        err = -ENOMEM;
 254        s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL);
 255        if (!s)
 256                goto out;
 257
 258        s->name = name;
 259        s->size = s->object_size = object_size;
 260        s->align = align;
 261        s->ctor = ctor;
 262        s->useroffset = useroffset;
 263        s->usersize = usersize;
 264
 265        err = __kmem_cache_create(s, flags);
 266        if (err)
 267                goto out_free_cache;
 268
 269        s->refcount = 1;
 270        list_add(&s->list, &slab_caches);
 271out:
 272        if (err)
 273                return ERR_PTR(err);
 274        return s;
 275
 276out_free_cache:
 277        kmem_cache_free(kmem_cache, s);
 278        goto out;
 279}
 280
 281/**
 282 * kmem_cache_create_usercopy - Create a cache with a region suitable
 283 * for copying to userspace
 284 * @name: A string which is used in /proc/slabinfo to identify this cache.
 285 * @size: The size of objects to be created in this cache.
 286 * @align: The required alignment for the objects.
 287 * @flags: SLAB flags
 288 * @useroffset: Usercopy region offset
 289 * @usersize: Usercopy region size
 290 * @ctor: A constructor for the objects.
 291 *
 292 * Cannot be called within a interrupt, but can be interrupted.
 293 * The @ctor is run when new pages are allocated by the cache.
 294 *
 295 * The flags are
 296 *
 297 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
 298 * to catch references to uninitialised memory.
 299 *
 300 * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check
 301 * for buffer overruns.
 302 *
 303 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
 304 * cacheline.  This can be beneficial if you're counting cycles as closely
 305 * as davem.
 306 *
 307 * Return: a pointer to the cache on success, NULL on failure.
 308 */
 309struct kmem_cache *
 310kmem_cache_create_usercopy(const char *name,
 311                  unsigned int size, unsigned int align,
 312                  slab_flags_t flags,
 313                  unsigned int useroffset, unsigned int usersize,
 314                  void (*ctor)(void *))
 315{
 316        struct kmem_cache *s = NULL;
 317        const char *cache_name;
 318        int err;
 319
 320#ifdef CONFIG_SLUB_DEBUG
 321        /*
 322         * If no slub_debug was enabled globally, the static key is not yet
 323         * enabled by setup_slub_debug(). Enable it if the cache is being
 324         * created with any of the debugging flags passed explicitly.
 325         */
 326        if (flags & SLAB_DEBUG_FLAGS)
 327                static_branch_enable(&slub_debug_enabled);
 328#endif
 329
 330        mutex_lock(&slab_mutex);
 331
 332        err = kmem_cache_sanity_check(name, size);
 333        if (err) {
 334                goto out_unlock;
 335        }
 336
 337        /* Refuse requests with allocator specific flags */
 338        if (flags & ~SLAB_FLAGS_PERMITTED) {
 339                err = -EINVAL;
 340                goto out_unlock;
 341        }
 342
 343        /*
 344         * Some allocators will constraint the set of valid flags to a subset
 345         * of all flags. We expect them to define CACHE_CREATE_MASK in this
 346         * case, and we'll just provide them with a sanitized version of the
 347         * passed flags.
 348         */
 349        flags &= CACHE_CREATE_MASK;
 350
 351        /* Fail closed on bad usersize of useroffset values. */
 352        if (WARN_ON(!usersize && useroffset) ||
 353            WARN_ON(size < usersize || size - usersize < useroffset))
 354                usersize = useroffset = 0;
 355
 356        if (!usersize)
 357                s = __kmem_cache_alias(name, size, align, flags, ctor);
 358        if (s)
 359                goto out_unlock;
 360
 361        cache_name = kstrdup_const(name, GFP_KERNEL);
 362        if (!cache_name) {
 363                err = -ENOMEM;
 364                goto out_unlock;
 365        }
 366
 367        s = create_cache(cache_name, size,
 368                         calculate_alignment(flags, align, size),
 369                         flags, useroffset, usersize, ctor, NULL);
 370        if (IS_ERR(s)) {
 371                err = PTR_ERR(s);
 372                kfree_const(cache_name);
 373        }
 374
 375out_unlock:
 376        mutex_unlock(&slab_mutex);
 377
 378        if (err) {
 379                if (flags & SLAB_PANIC)
 380                        panic("%s: Failed to create slab '%s'. Error %d\n",
 381                                __func__, name, err);
 382                else {
 383                        pr_warn("%s(%s) failed with error %d\n",
 384                                __func__, name, err);
 385                        dump_stack();
 386                }
 387                return NULL;
 388        }
 389        return s;
 390}
 391EXPORT_SYMBOL(kmem_cache_create_usercopy);
 392
 393/**
 394 * kmem_cache_create - Create a cache.
 395 * @name: A string which is used in /proc/slabinfo to identify this cache.
 396 * @size: The size of objects to be created in this cache.
 397 * @align: The required alignment for the objects.
 398 * @flags: SLAB flags
 399 * @ctor: A constructor for the objects.
 400 *
 401 * Cannot be called within a interrupt, but can be interrupted.
 402 * The @ctor is run when new pages are allocated by the cache.
 403 *
 404 * The flags are
 405 *
 406 * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5)
 407 * to catch references to uninitialised memory.
 408 *
 409 * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check
 410 * for buffer overruns.
 411 *
 412 * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
 413 * cacheline.  This can be beneficial if you're counting cycles as closely
 414 * as davem.
 415 *
 416 * Return: a pointer to the cache on success, NULL on failure.
 417 */
 418struct kmem_cache *
 419kmem_cache_create(const char *name, unsigned int size, unsigned int align,
 420                slab_flags_t flags, void (*ctor)(void *))
 421{
 422        return kmem_cache_create_usercopy(name, size, align, flags, 0, 0,
 423                                          ctor);
 424}
 425EXPORT_SYMBOL(kmem_cache_create);
 426
 427static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work)
 428{
 429        LIST_HEAD(to_destroy);
 430        struct kmem_cache *s, *s2;
 431
 432        /*
 433         * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the
 434         * @slab_caches_to_rcu_destroy list.  The slab pages are freed
 435         * through RCU and the associated kmem_cache are dereferenced
 436         * while freeing the pages, so the kmem_caches should be freed only
 437         * after the pending RCU operations are finished.  As rcu_barrier()
 438         * is a pretty slow operation, we batch all pending destructions
 439         * asynchronously.
 440         */
 441        mutex_lock(&slab_mutex);
 442        list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy);
 443        mutex_unlock(&slab_mutex);
 444
 445        if (list_empty(&to_destroy))
 446                return;
 447
 448        rcu_barrier();
 449
 450        list_for_each_entry_safe(s, s2, &to_destroy, list) {
 451                debugfs_slab_release(s);
 452                kfence_shutdown_cache(s);
 453#ifdef SLAB_SUPPORTS_SYSFS
 454                sysfs_slab_release(s);
 455#else
 456                slab_kmem_cache_release(s);
 457#endif
 458        }
 459}
 460
 461static int shutdown_cache(struct kmem_cache *s)
 462{
 463        /* free asan quarantined objects */
 464        kasan_cache_shutdown(s);
 465
 466        if (__kmem_cache_shutdown(s) != 0)
 467                return -EBUSY;
 468
 469        list_del(&s->list);
 470
 471        if (s->flags & SLAB_TYPESAFE_BY_RCU) {
 472#ifdef SLAB_SUPPORTS_SYSFS
 473                sysfs_slab_unlink(s);
 474#endif
 475                list_add_tail(&s->list, &slab_caches_to_rcu_destroy);
 476                schedule_work(&slab_caches_to_rcu_destroy_work);
 477        } else {
 478                kfence_shutdown_cache(s);
 479                debugfs_slab_release(s);
 480#ifdef SLAB_SUPPORTS_SYSFS
 481                sysfs_slab_unlink(s);
 482                sysfs_slab_release(s);
 483#else
 484                slab_kmem_cache_release(s);
 485#endif
 486        }
 487
 488        return 0;
 489}
 490
 491void slab_kmem_cache_release(struct kmem_cache *s)
 492{
 493        __kmem_cache_release(s);
 494        kfree_const(s->name);
 495        kmem_cache_free(kmem_cache, s);
 496}
 497
 498void kmem_cache_destroy(struct kmem_cache *s)
 499{
 500        int err;
 501
 502        if (unlikely(!s))
 503                return;
 504
 505        mutex_lock(&slab_mutex);
 506
 507        s->refcount--;
 508        if (s->refcount)
 509                goto out_unlock;
 510
 511        err = shutdown_cache(s);
 512        if (err) {
 513                pr_err("%s %s: Slab cache still has objects\n",
 514                       __func__, s->name);
 515                dump_stack();
 516        }
 517out_unlock:
 518        mutex_unlock(&slab_mutex);
 519}
 520EXPORT_SYMBOL(kmem_cache_destroy);
 521
 522/**
 523 * kmem_cache_shrink - Shrink a cache.
 524 * @cachep: The cache to shrink.
 525 *
 526 * Releases as many slabs as possible for a cache.
 527 * To help debugging, a zero exit status indicates all slabs were released.
 528 *
 529 * Return: %0 if all slabs were released, non-zero otherwise
 530 */
 531int kmem_cache_shrink(struct kmem_cache *cachep)
 532{
 533        int ret;
 534
 535
 536        kasan_cache_shrink(cachep);
 537        ret = __kmem_cache_shrink(cachep);
 538
 539        return ret;
 540}
 541EXPORT_SYMBOL(kmem_cache_shrink);
 542
 543bool slab_is_available(void)
 544{
 545        return slab_state >= UP;
 546}
 547
 548#ifdef CONFIG_PRINTK
 549/**
 550 * kmem_valid_obj - does the pointer reference a valid slab object?
 551 * @object: pointer to query.
 552 *
 553 * Return: %true if the pointer is to a not-yet-freed object from
 554 * kmalloc() or kmem_cache_alloc(), either %true or %false if the pointer
 555 * is to an already-freed object, and %false otherwise.
 556 */
 557bool kmem_valid_obj(void *object)
 558{
 559        struct page *page;
 560
 561        /* Some arches consider ZERO_SIZE_PTR to be a valid address. */
 562        if (object < (void *)PAGE_SIZE || !virt_addr_valid(object))
 563                return false;
 564        page = virt_to_head_page(object);
 565        return PageSlab(page);
 566}
 567EXPORT_SYMBOL_GPL(kmem_valid_obj);
 568
 569/**
 570 * kmem_dump_obj - Print available slab provenance information
 571 * @object: slab object for which to find provenance information.
 572 *
 573 * This function uses pr_cont(), so that the caller is expected to have
 574 * printed out whatever preamble is appropriate.  The provenance information
 575 * depends on the type of object and on how much debugging is enabled.
 576 * For a slab-cache object, the fact that it is a slab object is printed,
 577 * and, if available, the slab name, return address, and stack trace from
 578 * the allocation and last free path of that object.
 579 *
 580 * This function will splat if passed a pointer to a non-slab object.
 581 * If you are not sure what type of object you have, you should instead
 582 * use mem_dump_obj().
 583 */
 584void kmem_dump_obj(void *object)
 585{
 586        char *cp = IS_ENABLED(CONFIG_MMU) ? "" : "/vmalloc";
 587        int i;
 588        struct page *page;
 589        unsigned long ptroffset;
 590        struct kmem_obj_info kp = { };
 591
 592        if (WARN_ON_ONCE(!virt_addr_valid(object)))
 593                return;
 594        page = virt_to_head_page(object);
 595        if (WARN_ON_ONCE(!PageSlab(page))) {
 596                pr_cont(" non-slab memory.\n");
 597                return;
 598        }
 599        kmem_obj_info(&kp, object, page);
 600        if (kp.kp_slab_cache)
 601                pr_cont(" slab%s %s", cp, kp.kp_slab_cache->name);
 602        else
 603                pr_cont(" slab%s", cp);
 604        if (kp.kp_objp)
 605                pr_cont(" start %px", kp.kp_objp);
 606        if (kp.kp_data_offset)
 607                pr_cont(" data offset %lu", kp.kp_data_offset);
 608        if (kp.kp_objp) {
 609                ptroffset = ((char *)object - (char *)kp.kp_objp) - kp.kp_data_offset;
 610                pr_cont(" pointer offset %lu", ptroffset);
 611        }
 612        if (kp.kp_slab_cache && kp.kp_slab_cache->usersize)
 613                pr_cont(" size %u", kp.kp_slab_cache->usersize);
 614        if (kp.kp_ret)
 615                pr_cont(" allocated at %pS\n", kp.kp_ret);
 616        else
 617                pr_cont("\n");
 618        for (i = 0; i < ARRAY_SIZE(kp.kp_stack); i++) {
 619                if (!kp.kp_stack[i])
 620                        break;
 621                pr_info("    %pS\n", kp.kp_stack[i]);
 622        }
 623
 624        if (kp.kp_free_stack[0])
 625                pr_cont(" Free path:\n");
 626
 627        for (i = 0; i < ARRAY_SIZE(kp.kp_free_stack); i++) {
 628                if (!kp.kp_free_stack[i])
 629                        break;
 630                pr_info("    %pS\n", kp.kp_free_stack[i]);
 631        }
 632
 633}
 634EXPORT_SYMBOL_GPL(kmem_dump_obj);
 635#endif
 636
 637#ifndef CONFIG_SLOB
 638/* Create a cache during boot when no slab services are available yet */
 639void __init create_boot_cache(struct kmem_cache *s, const char *name,
 640                unsigned int size, slab_flags_t flags,
 641                unsigned int useroffset, unsigned int usersize)
 642{
 643        int err;
 644        unsigned int align = ARCH_KMALLOC_MINALIGN;
 645
 646        s->name = name;
 647        s->size = s->object_size = size;
 648
 649        /*
 650         * For power of two sizes, guarantee natural alignment for kmalloc
 651         * caches, regardless of SL*B debugging options.
 652         */
 653        if (is_power_of_2(size))
 654                align = max(align, size);
 655        s->align = calculate_alignment(flags, align, size);
 656
 657        s->useroffset = useroffset;
 658        s->usersize = usersize;
 659
 660        err = __kmem_cache_create(s, flags);
 661
 662        if (err)
 663                panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n",
 664                                        name, size, err);
 665
 666        s->refcount = -1;       /* Exempt from merging for now */
 667}
 668
 669struct kmem_cache *__init create_kmalloc_cache(const char *name,
 670                unsigned int size, slab_flags_t flags,
 671                unsigned int useroffset, unsigned int usersize)
 672{
 673        struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
 674
 675        if (!s)
 676                panic("Out of memory when creating slab %s\n", name);
 677
 678        create_boot_cache(s, name, size, flags, useroffset, usersize);
 679        kasan_cache_create_kmalloc(s);
 680        list_add(&s->list, &slab_caches);
 681        s->refcount = 1;
 682        return s;
 683}
 684
 685struct kmem_cache *
 686kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init =
 687{ /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ };
 688EXPORT_SYMBOL(kmalloc_caches);
 689
 690/*
 691 * Conversion table for small slabs sizes / 8 to the index in the
 692 * kmalloc array. This is necessary for slabs < 192 since we have non power
 693 * of two cache sizes there. The size of larger slabs can be determined using
 694 * fls.
 695 */
 696static u8 size_index[24] __ro_after_init = {
 697        3,      /* 8 */
 698        4,      /* 16 */
 699        5,      /* 24 */
 700        5,      /* 32 */
 701        6,      /* 40 */
 702        6,      /* 48 */
 703        6,      /* 56 */
 704        6,      /* 64 */
 705        1,      /* 72 */
 706        1,      /* 80 */
 707        1,      /* 88 */
 708        1,      /* 96 */
 709        7,      /* 104 */
 710        7,      /* 112 */
 711        7,      /* 120 */
 712        7,      /* 128 */
 713        2,      /* 136 */
 714        2,      /* 144 */
 715        2,      /* 152 */
 716        2,      /* 160 */
 717        2,      /* 168 */
 718        2,      /* 176 */
 719        2,      /* 184 */
 720        2       /* 192 */
 721};
 722
 723static inline unsigned int size_index_elem(unsigned int bytes)
 724{
 725        return (bytes - 1) / 8;
 726}
 727
 728/*
 729 * Find the kmem_cache structure that serves a given size of
 730 * allocation
 731 */
 732struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
 733{
 734        unsigned int index;
 735
 736        if (size <= 192) {
 737                if (!size)
 738                        return ZERO_SIZE_PTR;
 739
 740                index = size_index[size_index_elem(size)];
 741        } else {
 742                if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE))
 743                        return NULL;
 744                index = fls(size - 1);
 745        }
 746
 747        return kmalloc_caches[kmalloc_type(flags)][index];
 748}
 749
 750#ifdef CONFIG_ZONE_DMA
 751#define KMALLOC_DMA_NAME(sz)    .name[KMALLOC_DMA] = "dma-kmalloc-" #sz,
 752#else
 753#define KMALLOC_DMA_NAME(sz)
 754#endif
 755
 756#ifdef CONFIG_MEMCG_KMEM
 757#define KMALLOC_CGROUP_NAME(sz) .name[KMALLOC_CGROUP] = "kmalloc-cg-" #sz,
 758#else
 759#define KMALLOC_CGROUP_NAME(sz)
 760#endif
 761
 762#define INIT_KMALLOC_INFO(__size, __short_size)                 \
 763{                                                               \
 764        .name[KMALLOC_NORMAL]  = "kmalloc-" #__short_size,      \
 765        .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size,  \
 766        KMALLOC_CGROUP_NAME(__short_size)                       \
 767        KMALLOC_DMA_NAME(__short_size)                          \
 768        .size = __size,                                         \
 769}
 770
 771/*
 772 * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
 773 * kmalloc_index() supports up to 2^25=32MB, so the final entry of the table is
 774 * kmalloc-32M.
 775 */
 776const struct kmalloc_info_struct kmalloc_info[] __initconst = {
 777        INIT_KMALLOC_INFO(0, 0),
 778        INIT_KMALLOC_INFO(96, 96),
 779        INIT_KMALLOC_INFO(192, 192),
 780        INIT_KMALLOC_INFO(8, 8),
 781        INIT_KMALLOC_INFO(16, 16),
 782        INIT_KMALLOC_INFO(32, 32),
 783        INIT_KMALLOC_INFO(64, 64),
 784        INIT_KMALLOC_INFO(128, 128),
 785        INIT_KMALLOC_INFO(256, 256),
 786        INIT_KMALLOC_INFO(512, 512),
 787        INIT_KMALLOC_INFO(1024, 1k),
 788        INIT_KMALLOC_INFO(2048, 2k),
 789        INIT_KMALLOC_INFO(4096, 4k),
 790        INIT_KMALLOC_INFO(8192, 8k),
 791        INIT_KMALLOC_INFO(16384, 16k),
 792        INIT_KMALLOC_INFO(32768, 32k),
 793        INIT_KMALLOC_INFO(65536, 64k),
 794        INIT_KMALLOC_INFO(131072, 128k),
 795        INIT_KMALLOC_INFO(262144, 256k),
 796        INIT_KMALLOC_INFO(524288, 512k),
 797        INIT_KMALLOC_INFO(1048576, 1M),
 798        INIT_KMALLOC_INFO(2097152, 2M),
 799        INIT_KMALLOC_INFO(4194304, 4M),
 800        INIT_KMALLOC_INFO(8388608, 8M),
 801        INIT_KMALLOC_INFO(16777216, 16M),
 802        INIT_KMALLOC_INFO(33554432, 32M)
 803};
 804
 805/*
 806 * Patch up the size_index table if we have strange large alignment
 807 * requirements for the kmalloc array. This is only the case for
 808 * MIPS it seems. The standard arches will not generate any code here.
 809 *
 810 * Largest permitted alignment is 256 bytes due to the way we
 811 * handle the index determination for the smaller caches.
 812 *
 813 * Make sure that nothing crazy happens if someone starts tinkering
 814 * around with ARCH_KMALLOC_MINALIGN
 815 */
 816void __init setup_kmalloc_cache_index_table(void)
 817{
 818        unsigned int i;
 819
 820        BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
 821                (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
 822
 823        for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
 824                unsigned int elem = size_index_elem(i);
 825
 826                if (elem >= ARRAY_SIZE(size_index))
 827                        break;
 828                size_index[elem] = KMALLOC_SHIFT_LOW;
 829        }
 830
 831        if (KMALLOC_MIN_SIZE >= 64) {
 832                /*
 833                 * The 96 byte size cache is not used if the alignment
 834                 * is 64 byte.
 835                 */
 836                for (i = 64 + 8; i <= 96; i += 8)
 837                        size_index[size_index_elem(i)] = 7;
 838
 839        }
 840
 841        if (KMALLOC_MIN_SIZE >= 128) {
 842                /*
 843                 * The 192 byte sized cache is not used if the alignment
 844                 * is 128 byte. Redirect kmalloc to use the 256 byte cache
 845                 * instead.
 846                 */
 847                for (i = 128 + 8; i <= 192; i += 8)
 848                        size_index[size_index_elem(i)] = 8;
 849        }
 850}
 851
 852static void __init
 853new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
 854{
 855        if (type == KMALLOC_RECLAIM) {
 856                flags |= SLAB_RECLAIM_ACCOUNT;
 857        } else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
 858                if (cgroup_memory_nokmem) {
 859                        kmalloc_caches[type][idx] = kmalloc_caches[KMALLOC_NORMAL][idx];
 860                        return;
 861                }
 862                flags |= SLAB_ACCOUNT;
 863        }
 864
 865        kmalloc_caches[type][idx] = create_kmalloc_cache(
 866                                        kmalloc_info[idx].name[type],
 867                                        kmalloc_info[idx].size, flags, 0,
 868                                        kmalloc_info[idx].size);
 869
 870        /*
 871         * If CONFIG_MEMCG_KMEM is enabled, disable cache merging for
 872         * KMALLOC_NORMAL caches.
 873         */
 874        if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_NORMAL))
 875                kmalloc_caches[type][idx]->refcount = -1;
 876}
 877
 878/*
 879 * Create the kmalloc array. Some of the regular kmalloc arrays
 880 * may already have been created because they were needed to
 881 * enable allocations for slab creation.
 882 */
 883void __init create_kmalloc_caches(slab_flags_t flags)
 884{
 885        int i;
 886        enum kmalloc_cache_type type;
 887
 888        /*
 889         * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined
 890         */
 891        for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) {
 892                for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
 893                        if (!kmalloc_caches[type][i])
 894                                new_kmalloc_cache(i, type, flags);
 895
 896                        /*
 897                         * Caches that are not of the two-to-the-power-of size.
 898                         * These have to be created immediately after the
 899                         * earlier power of two caches
 900                         */
 901                        if (KMALLOC_MIN_SIZE <= 32 && i == 6 &&
 902                                        !kmalloc_caches[type][1])
 903                                new_kmalloc_cache(1, type, flags);
 904                        if (KMALLOC_MIN_SIZE <= 64 && i == 7 &&
 905                                        !kmalloc_caches[type][2])
 906                                new_kmalloc_cache(2, type, flags);
 907                }
 908        }
 909
 910        /* Kmalloc array is now usable */
 911        slab_state = UP;
 912
 913#ifdef CONFIG_ZONE_DMA
 914        for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
 915                struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i];
 916
 917                if (s) {
 918                        kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache(
 919                                kmalloc_info[i].name[KMALLOC_DMA],
 920                                kmalloc_info[i].size,
 921                                SLAB_CACHE_DMA | flags, 0,
 922                                kmalloc_info[i].size);
 923                }
 924        }
 925#endif
 926}
 927#endif /* !CONFIG_SLOB */
 928
 929gfp_t kmalloc_fix_flags(gfp_t flags)
 930{
 931        gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK;
 932
 933        flags &= ~GFP_SLAB_BUG_MASK;
 934        pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n",
 935                        invalid_mask, &invalid_mask, flags, &flags);
 936        dump_stack();
 937
 938        return flags;
 939}
 940
 941/*
 942 * To avoid unnecessary overhead, we pass through large allocation requests
 943 * directly to the page allocator. We use __GFP_COMP, because we will need to
 944 * know the allocation order to free the pages properly in kfree.
 945 */
 946void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
 947{
 948        void *ret = NULL;
 949        struct page *page;
 950
 951        if (unlikely(flags & GFP_SLAB_BUG_MASK))
 952                flags = kmalloc_fix_flags(flags);
 953
 954        flags |= __GFP_COMP;
 955        page = alloc_pages(flags, order);
 956        if (likely(page)) {
 957                ret = page_address(page);
 958                mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B,
 959                                      PAGE_SIZE << order);
 960        }
 961        ret = kasan_kmalloc_large(ret, size, flags);
 962        /* As ret might get tagged, call kmemleak hook after KASAN. */
 963        kmemleak_alloc(ret, size, 1, flags);
 964        return ret;
 965}
 966EXPORT_SYMBOL(kmalloc_order);
 967
 968#ifdef CONFIG_TRACING
 969void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
 970{
 971        void *ret = kmalloc_order(size, flags, order);
 972        trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
 973        return ret;
 974}
 975EXPORT_SYMBOL(kmalloc_order_trace);
 976#endif
 977
 978#ifdef CONFIG_SLAB_FREELIST_RANDOM
 979/* Randomize a generic freelist */
 980static void freelist_randomize(struct rnd_state *state, unsigned int *list,
 981                               unsigned int count)
 982{
 983        unsigned int rand;
 984        unsigned int i;
 985
 986        for (i = 0; i < count; i++)
 987                list[i] = i;
 988
 989        /* Fisher-Yates shuffle */
 990        for (i = count - 1; i > 0; i--) {
 991                rand = prandom_u32_state(state);
 992                rand %= (i + 1);
 993                swap(list[i], list[rand]);
 994        }
 995}
 996
 997/* Create a random sequence per cache */
 998int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
 999                                    gfp_t gfp)
1000{
1001        struct rnd_state state;
1002
1003        if (count < 2 || cachep->random_seq)
1004                return 0;
1005
1006        cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
1007        if (!cachep->random_seq)
1008                return -ENOMEM;
1009
1010        /* Get best entropy at this stage of boot */
1011        prandom_seed_state(&state, get_random_long());
1012
1013        freelist_randomize(&state, cachep->random_seq, count);
1014        return 0;
1015}
1016
1017/* Destroy the per-cache random freelist sequence */
1018void cache_random_seq_destroy(struct kmem_cache *cachep)
1019{
1020        kfree(cachep->random_seq);
1021        cachep->random_seq = NULL;
1022}
1023#endif /* CONFIG_SLAB_FREELIST_RANDOM */
1024
1025#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
1026#ifdef CONFIG_SLAB
1027#define SLABINFO_RIGHTS (0600)
1028#else
1029#define SLABINFO_RIGHTS (0400)
1030#endif
1031
1032static void print_slabinfo_header(struct seq_file *m)
1033{
1034        /*
1035         * Output format version, so at least we can change it
1036         * without _too_ many complaints.
1037         */
1038#ifdef CONFIG_DEBUG_SLAB
1039        seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
1040#else
1041        seq_puts(m, "slabinfo - version: 2.1\n");
1042#endif
1043        seq_puts(m, "# name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
1044        seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
1045        seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
1046#ifdef CONFIG_DEBUG_SLAB
1047        seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
1048        seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
1049#endif
1050        seq_putc(m, '\n');
1051}
1052
1053void *slab_start(struct seq_file *m, loff_t *pos)
1054{
1055        mutex_lock(&slab_mutex);
1056        return seq_list_start(&slab_caches, *pos);
1057}
1058
1059void *slab_next(struct seq_file *m, void *p, loff_t *pos)
1060{
1061        return seq_list_next(p, &slab_caches, pos);
1062}
1063
1064void slab_stop(struct seq_file *m, void *p)
1065{
1066        mutex_unlock(&slab_mutex);
1067}
1068
1069static void cache_show(struct kmem_cache *s, struct seq_file *m)
1070{
1071        struct slabinfo sinfo;
1072
1073        memset(&sinfo, 0, sizeof(sinfo));
1074        get_slabinfo(s, &sinfo);
1075
1076        seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
1077                   s->name, sinfo.active_objs, sinfo.num_objs, s->size,
1078                   sinfo.objects_per_slab, (1 << sinfo.cache_order));
1079
1080        seq_printf(m, " : tunables %4u %4u %4u",
1081                   sinfo.limit, sinfo.batchcount, sinfo.shared);
1082        seq_printf(m, " : slabdata %6lu %6lu %6lu",
1083                   sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1084        slabinfo_show_stats(m, s);
1085        seq_putc(m, '\n');
1086}
1087
1088static int slab_show(struct seq_file *m, void *p)
1089{
1090        struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1091
1092        if (p == slab_caches.next)
1093                print_slabinfo_header(m);
1094        cache_show(s, m);
1095        return 0;
1096}
1097
1098void dump_unreclaimable_slab(void)
1099{
1100        struct kmem_cache *s;
1101        struct slabinfo sinfo;
1102
1103        /*
1104         * Here acquiring slab_mutex is risky since we don't prefer to get
1105         * sleep in oom path. But, without mutex hold, it may introduce a
1106         * risk of crash.
1107         * Use mutex_trylock to protect the list traverse, dump nothing
1108         * without acquiring the mutex.
1109         */
1110        if (!mutex_trylock(&slab_mutex)) {
1111                pr_warn("excessive unreclaimable slab but cannot dump stats\n");
1112                return;
1113        }
1114
1115        pr_info("Unreclaimable slab info:\n");
1116        pr_info("Name                      Used          Total\n");
1117
1118        list_for_each_entry(s, &slab_caches, list) {
1119                if (s->flags & SLAB_RECLAIM_ACCOUNT)
1120                        continue;
1121
1122                get_slabinfo(s, &sinfo);
1123
1124                if (sinfo.num_objs > 0)
1125                        pr_info("%-17s %10luKB %10luKB\n", s->name,
1126                                (sinfo.active_objs * s->size) / 1024,
1127                                (sinfo.num_objs * s->size) / 1024);
1128        }
1129        mutex_unlock(&slab_mutex);
1130}
1131
1132#if defined(CONFIG_MEMCG_KMEM)
1133int memcg_slab_show(struct seq_file *m, void *p)
1134{
1135        /*
1136         * Deprecated.
1137         * Please, take a look at tools/cgroup/slabinfo.py .
1138         */
1139        return 0;
1140}
1141#endif
1142
1143/*
1144 * slabinfo_op - iterator that generates /proc/slabinfo
1145 *
1146 * Output layout:
1147 * cache-name
1148 * num-active-objs
1149 * total-objs
1150 * object size
1151 * num-active-slabs
1152 * total-slabs
1153 * num-pages-per-slab
1154 * + further values on SMP and with statistics enabled
1155 */
1156static const struct seq_operations slabinfo_op = {
1157        .start = slab_start,
1158        .next = slab_next,
1159        .stop = slab_stop,
1160        .show = slab_show,
1161};
1162
1163static int slabinfo_open(struct inode *inode, struct file *file)
1164{
1165        return seq_open(file, &slabinfo_op);
1166}
1167
1168static const struct proc_ops slabinfo_proc_ops = {
1169        .proc_flags     = PROC_ENTRY_PERMANENT,
1170        .proc_open      = slabinfo_open,
1171        .proc_read      = seq_read,
1172        .proc_write     = slabinfo_write,
1173        .proc_lseek     = seq_lseek,
1174        .proc_release   = seq_release,
1175};
1176
1177static int __init slab_proc_init(void)
1178{
1179        proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops);
1180        return 0;
1181}
1182module_init(slab_proc_init);
1183
1184#endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */
1185
1186static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1187                                           gfp_t flags)
1188{
1189        void *ret;
1190        size_t ks;
1191
1192        /* Don't use instrumented ksize to allow precise KASAN poisoning. */
1193        if (likely(!ZERO_OR_NULL_PTR(p))) {
1194                if (!kasan_check_byte(p))
1195                        return NULL;
1196                ks = kfence_ksize(p) ?: __ksize(p);
1197        } else
1198                ks = 0;
1199
1200        /* If the object still fits, repoison it precisely. */
1201        if (ks >= new_size) {
1202                p = kasan_krealloc((void *)p, new_size, flags);
1203                return (void *)p;
1204        }
1205
1206        ret = kmalloc_track_caller(new_size, flags);
1207        if (ret && p) {
1208                /* Disable KASAN checks as the object's redzone is accessed. */
1209                kasan_disable_current();
1210                memcpy(ret, kasan_reset_tag(p), ks);
1211                kasan_enable_current();
1212        }
1213
1214        return ret;
1215}
1216
1217/**
1218 * krealloc - reallocate memory. The contents will remain unchanged.
1219 * @p: object to reallocate memory for.
1220 * @new_size: how many bytes of memory are required.
1221 * @flags: the type of memory to allocate.
1222 *
1223 * The contents of the object pointed to are preserved up to the
1224 * lesser of the new and old sizes (__GFP_ZERO flag is effectively ignored).
1225 * If @p is %NULL, krealloc() behaves exactly like kmalloc().  If @new_size
1226 * is 0 and @p is not a %NULL pointer, the object pointed to is freed.
1227 *
1228 * Return: pointer to the allocated memory or %NULL in case of error
1229 */
1230void *krealloc(const void *p, size_t new_size, gfp_t flags)
1231{
1232        void *ret;
1233
1234        if (unlikely(!new_size)) {
1235                kfree(p);
1236                return ZERO_SIZE_PTR;
1237        }
1238
1239        ret = __do_krealloc(p, new_size, flags);
1240        if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret))
1241                kfree(p);
1242
1243        return ret;
1244}
1245EXPORT_SYMBOL(krealloc);
1246
1247/**
1248 * kfree_sensitive - Clear sensitive information in memory before freeing
1249 * @p: object to free memory of
1250 *
1251 * The memory of the object @p points to is zeroed before freed.
1252 * If @p is %NULL, kfree_sensitive() does nothing.
1253 *
1254 * Note: this function zeroes the whole allocated buffer which can be a good
1255 * deal bigger than the requested buffer size passed to kmalloc(). So be
1256 * careful when using this function in performance sensitive code.
1257 */
1258void kfree_sensitive(const void *p)
1259{
1260        size_t ks;
1261        void *mem = (void *)p;
1262
1263        ks = ksize(mem);
1264        if (ks)
1265                memzero_explicit(mem, ks);
1266        kfree(mem);
1267}
1268EXPORT_SYMBOL(kfree_sensitive);
1269
1270/**
1271 * ksize - get the actual amount of memory allocated for a given object
1272 * @objp: Pointer to the object
1273 *
1274 * kmalloc may internally round up allocations and return more memory
1275 * than requested. ksize() can be used to determine the actual amount of
1276 * memory allocated. The caller may use this additional memory, even though
1277 * a smaller amount of memory was initially specified with the kmalloc call.
1278 * The caller must guarantee that objp points to a valid object previously
1279 * allocated with either kmalloc() or kmem_cache_alloc(). The object
1280 * must not be freed during the duration of the call.
1281 *
1282 * Return: size of the actual memory used by @objp in bytes
1283 */
1284size_t ksize(const void *objp)
1285{
1286        size_t size;
1287
1288        /*
1289         * We need to first check that the pointer to the object is valid, and
1290         * only then unpoison the memory. The report printed from ksize() is
1291         * more useful, then when it's printed later when the behaviour could
1292         * be undefined due to a potential use-after-free or double-free.
1293         *
1294         * We use kasan_check_byte(), which is supported for the hardware
1295         * tag-based KASAN mode, unlike kasan_check_read/write().
1296         *
1297         * If the pointed to memory is invalid, we return 0 to avoid users of
1298         * ksize() writing to and potentially corrupting the memory region.
1299         *
1300         * We want to perform the check before __ksize(), to avoid potentially
1301         * crashing in __ksize() due to accessing invalid metadata.
1302         */
1303        if (unlikely(ZERO_OR_NULL_PTR(objp)) || !kasan_check_byte(objp))
1304                return 0;
1305
1306        size = kfence_ksize(objp) ?: __ksize(objp);
1307        /*
1308         * We assume that ksize callers could use whole allocated area,
1309         * so we need to unpoison this area.
1310         */
1311        kasan_unpoison_range(objp, size);
1312        return size;
1313}
1314EXPORT_SYMBOL(ksize);
1315
1316/* Tracepoints definitions. */
1317EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1318EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1319EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1320EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1321EXPORT_TRACEPOINT_SYMBOL(kfree);
1322EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
1323
1324int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
1325{
1326        if (__should_failslab(s, gfpflags))
1327                return -ENOMEM;
1328        return 0;
1329}
1330ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
1331
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