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