xref: /openbmc/linux/mm/slab_common.c (revision 1d7a0395)
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 
35 enum slab_state slab_state;
36 LIST_HEAD(slab_caches);
37 DEFINE_MUTEX(slab_mutex);
38 struct kmem_cache *kmem_cache;
39 
40 #ifdef CONFIG_HARDENED_USERCOPY
41 bool usercopy_fallback __ro_after_init =
42 		IS_ENABLED(CONFIG_HARDENED_USERCOPY_FALLBACK);
43 module_param(usercopy_fallback, bool, 0400);
44 MODULE_PARM_DESC(usercopy_fallback,
45 		"WARN instead of reject usercopy whitelist violations");
46 #endif
47 
48 static LIST_HEAD(slab_caches_to_rcu_destroy);
49 static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work);
50 static 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  */
66 static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT);
67 
68 static int __init setup_slab_nomerge(char *str)
69 {
70 	slab_nomerge = true;
71 	return 1;
72 }
73 
74 static 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  */
91 unsigned int kmem_cache_size(struct kmem_cache *s)
92 {
93 	return s->object_size;
94 }
95 EXPORT_SYMBOL(kmem_cache_size);
96 
97 #ifdef CONFIG_DEBUG_VM
98 static 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
109 static inline int kmem_cache_sanity_check(const char *name, unsigned int size)
110 {
111 	return 0;
112 }
113 #endif
114 
115 void __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 
127 int __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  */
146 static 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  */
174 int 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 
194 struct 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 
241 static 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);
271 out:
272 	if (err)
273 		return ERR_PTR(err);
274 	return s;
275 
276 out_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  */
309 struct kmem_cache *
310 kmem_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 
375 out_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 }
391 EXPORT_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  */
418 struct kmem_cache *
419 kmem_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 }
425 EXPORT_SYMBOL(kmem_cache_create);
426 
427 static 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 
461 static 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 
491 void 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 
498 void 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 	}
517 out_unlock:
518 	mutex_unlock(&slab_mutex);
519 }
520 EXPORT_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  */
531 int 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 }
541 EXPORT_SYMBOL(kmem_cache_shrink);
542 
543 bool 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  */
557 bool 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 }
567 EXPORT_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 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  */
584 void 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 EXPORT_SYMBOL_GPL(kmem_dump_obj);
625 #endif
626 
627 #ifndef CONFIG_SLOB
628 /* Create a cache during boot when no slab services are available yet */
629 void __init create_boot_cache(struct kmem_cache *s, const char *name,
630 		unsigned int size, slab_flags_t flags,
631 		unsigned int useroffset, unsigned int usersize)
632 {
633 	int err;
634 	unsigned int align = ARCH_KMALLOC_MINALIGN;
635 
636 	s->name = name;
637 	s->size = s->object_size = size;
638 
639 	/*
640 	 * For power of two sizes, guarantee natural alignment for kmalloc
641 	 * caches, regardless of SL*B debugging options.
642 	 */
643 	if (is_power_of_2(size))
644 		align = max(align, size);
645 	s->align = calculate_alignment(flags, align, size);
646 
647 	s->useroffset = useroffset;
648 	s->usersize = usersize;
649 
650 	err = __kmem_cache_create(s, flags);
651 
652 	if (err)
653 		panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n",
654 					name, size, err);
655 
656 	s->refcount = -1;	/* Exempt from merging for now */
657 }
658 
659 struct kmem_cache *__init create_kmalloc_cache(const char *name,
660 		unsigned int size, slab_flags_t flags,
661 		unsigned int useroffset, unsigned int usersize)
662 {
663 	struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
664 
665 	if (!s)
666 		panic("Out of memory when creating slab %s\n", name);
667 
668 	create_boot_cache(s, name, size, flags, useroffset, usersize);
669 	kasan_cache_create_kmalloc(s);
670 	list_add(&s->list, &slab_caches);
671 	s->refcount = 1;
672 	return s;
673 }
674 
675 struct kmem_cache *
676 kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init =
677 { /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ };
678 EXPORT_SYMBOL(kmalloc_caches);
679 
680 /*
681  * Conversion table for small slabs sizes / 8 to the index in the
682  * kmalloc array. This is necessary for slabs < 192 since we have non power
683  * of two cache sizes there. The size of larger slabs can be determined using
684  * fls.
685  */
686 static u8 size_index[24] __ro_after_init = {
687 	3,	/* 8 */
688 	4,	/* 16 */
689 	5,	/* 24 */
690 	5,	/* 32 */
691 	6,	/* 40 */
692 	6,	/* 48 */
693 	6,	/* 56 */
694 	6,	/* 64 */
695 	1,	/* 72 */
696 	1,	/* 80 */
697 	1,	/* 88 */
698 	1,	/* 96 */
699 	7,	/* 104 */
700 	7,	/* 112 */
701 	7,	/* 120 */
702 	7,	/* 128 */
703 	2,	/* 136 */
704 	2,	/* 144 */
705 	2,	/* 152 */
706 	2,	/* 160 */
707 	2,	/* 168 */
708 	2,	/* 176 */
709 	2,	/* 184 */
710 	2	/* 192 */
711 };
712 
713 static inline unsigned int size_index_elem(unsigned int bytes)
714 {
715 	return (bytes - 1) / 8;
716 }
717 
718 /*
719  * Find the kmem_cache structure that serves a given size of
720  * allocation
721  */
722 struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
723 {
724 	unsigned int index;
725 
726 	if (size <= 192) {
727 		if (!size)
728 			return ZERO_SIZE_PTR;
729 
730 		index = size_index[size_index_elem(size)];
731 	} else {
732 		if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE))
733 			return NULL;
734 		index = fls(size - 1);
735 	}
736 
737 	return kmalloc_caches[kmalloc_type(flags)][index];
738 }
739 
740 #ifdef CONFIG_ZONE_DMA
741 #define KMALLOC_DMA_NAME(sz)	.name[KMALLOC_DMA] = "dma-kmalloc-" #sz,
742 #else
743 #define KMALLOC_DMA_NAME(sz)
744 #endif
745 
746 #ifdef CONFIG_MEMCG_KMEM
747 #define KMALLOC_CGROUP_NAME(sz)	.name[KMALLOC_CGROUP] = "kmalloc-cg-" #sz,
748 #else
749 #define KMALLOC_CGROUP_NAME(sz)
750 #endif
751 
752 #define INIT_KMALLOC_INFO(__size, __short_size)			\
753 {								\
754 	.name[KMALLOC_NORMAL]  = "kmalloc-" #__short_size,	\
755 	.name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size,	\
756 	KMALLOC_CGROUP_NAME(__short_size)			\
757 	KMALLOC_DMA_NAME(__short_size)				\
758 	.size = __size,						\
759 }
760 
761 /*
762  * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time.
763  * kmalloc_index() supports up to 2^25=32MB, so the final entry of the table is
764  * kmalloc-32M.
765  */
766 const struct kmalloc_info_struct kmalloc_info[] __initconst = {
767 	INIT_KMALLOC_INFO(0, 0),
768 	INIT_KMALLOC_INFO(96, 96),
769 	INIT_KMALLOC_INFO(192, 192),
770 	INIT_KMALLOC_INFO(8, 8),
771 	INIT_KMALLOC_INFO(16, 16),
772 	INIT_KMALLOC_INFO(32, 32),
773 	INIT_KMALLOC_INFO(64, 64),
774 	INIT_KMALLOC_INFO(128, 128),
775 	INIT_KMALLOC_INFO(256, 256),
776 	INIT_KMALLOC_INFO(512, 512),
777 	INIT_KMALLOC_INFO(1024, 1k),
778 	INIT_KMALLOC_INFO(2048, 2k),
779 	INIT_KMALLOC_INFO(4096, 4k),
780 	INIT_KMALLOC_INFO(8192, 8k),
781 	INIT_KMALLOC_INFO(16384, 16k),
782 	INIT_KMALLOC_INFO(32768, 32k),
783 	INIT_KMALLOC_INFO(65536, 64k),
784 	INIT_KMALLOC_INFO(131072, 128k),
785 	INIT_KMALLOC_INFO(262144, 256k),
786 	INIT_KMALLOC_INFO(524288, 512k),
787 	INIT_KMALLOC_INFO(1048576, 1M),
788 	INIT_KMALLOC_INFO(2097152, 2M),
789 	INIT_KMALLOC_INFO(4194304, 4M),
790 	INIT_KMALLOC_INFO(8388608, 8M),
791 	INIT_KMALLOC_INFO(16777216, 16M),
792 	INIT_KMALLOC_INFO(33554432, 32M)
793 };
794 
795 /*
796  * Patch up the size_index table if we have strange large alignment
797  * requirements for the kmalloc array. This is only the case for
798  * MIPS it seems. The standard arches will not generate any code here.
799  *
800  * Largest permitted alignment is 256 bytes due to the way we
801  * handle the index determination for the smaller caches.
802  *
803  * Make sure that nothing crazy happens if someone starts tinkering
804  * around with ARCH_KMALLOC_MINALIGN
805  */
806 void __init setup_kmalloc_cache_index_table(void)
807 {
808 	unsigned int i;
809 
810 	BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
811 		(KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
812 
813 	for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
814 		unsigned int elem = size_index_elem(i);
815 
816 		if (elem >= ARRAY_SIZE(size_index))
817 			break;
818 		size_index[elem] = KMALLOC_SHIFT_LOW;
819 	}
820 
821 	if (KMALLOC_MIN_SIZE >= 64) {
822 		/*
823 		 * The 96 byte size cache is not used if the alignment
824 		 * is 64 byte.
825 		 */
826 		for (i = 64 + 8; i <= 96; i += 8)
827 			size_index[size_index_elem(i)] = 7;
828 
829 	}
830 
831 	if (KMALLOC_MIN_SIZE >= 128) {
832 		/*
833 		 * The 192 byte sized cache is not used if the alignment
834 		 * is 128 byte. Redirect kmalloc to use the 256 byte cache
835 		 * instead.
836 		 */
837 		for (i = 128 + 8; i <= 192; i += 8)
838 			size_index[size_index_elem(i)] = 8;
839 	}
840 }
841 
842 static void __init
843 new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
844 {
845 	if (type == KMALLOC_RECLAIM) {
846 		flags |= SLAB_RECLAIM_ACCOUNT;
847 	} else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
848 		if (cgroup_memory_nokmem) {
849 			kmalloc_caches[type][idx] = kmalloc_caches[KMALLOC_NORMAL][idx];
850 			return;
851 		}
852 		flags |= SLAB_ACCOUNT;
853 	}
854 
855 	kmalloc_caches[type][idx] = create_kmalloc_cache(
856 					kmalloc_info[idx].name[type],
857 					kmalloc_info[idx].size, flags, 0,
858 					kmalloc_info[idx].size);
859 
860 	/*
861 	 * If CONFIG_MEMCG_KMEM is enabled, disable cache merging for
862 	 * KMALLOC_NORMAL caches.
863 	 */
864 	if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_NORMAL))
865 		kmalloc_caches[type][idx]->refcount = -1;
866 }
867 
868 /*
869  * Create the kmalloc array. Some of the regular kmalloc arrays
870  * may already have been created because they were needed to
871  * enable allocations for slab creation.
872  */
873 void __init create_kmalloc_caches(slab_flags_t flags)
874 {
875 	int i;
876 	enum kmalloc_cache_type type;
877 
878 	/*
879 	 * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined
880 	 */
881 	for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) {
882 		for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
883 			if (!kmalloc_caches[type][i])
884 				new_kmalloc_cache(i, type, flags);
885 
886 			/*
887 			 * Caches that are not of the two-to-the-power-of size.
888 			 * These have to be created immediately after the
889 			 * earlier power of two caches
890 			 */
891 			if (KMALLOC_MIN_SIZE <= 32 && i == 6 &&
892 					!kmalloc_caches[type][1])
893 				new_kmalloc_cache(1, type, flags);
894 			if (KMALLOC_MIN_SIZE <= 64 && i == 7 &&
895 					!kmalloc_caches[type][2])
896 				new_kmalloc_cache(2, type, flags);
897 		}
898 	}
899 
900 	/* Kmalloc array is now usable */
901 	slab_state = UP;
902 
903 #ifdef CONFIG_ZONE_DMA
904 	for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) {
905 		struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i];
906 
907 		if (s) {
908 			kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache(
909 				kmalloc_info[i].name[KMALLOC_DMA],
910 				kmalloc_info[i].size,
911 				SLAB_CACHE_DMA | flags, 0,
912 				kmalloc_info[i].size);
913 		}
914 	}
915 #endif
916 }
917 #endif /* !CONFIG_SLOB */
918 
919 gfp_t kmalloc_fix_flags(gfp_t flags)
920 {
921 	gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK;
922 
923 	flags &= ~GFP_SLAB_BUG_MASK;
924 	pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n",
925 			invalid_mask, &invalid_mask, flags, &flags);
926 	dump_stack();
927 
928 	return flags;
929 }
930 
931 /*
932  * To avoid unnecessary overhead, we pass through large allocation requests
933  * directly to the page allocator. We use __GFP_COMP, because we will need to
934  * know the allocation order to free the pages properly in kfree.
935  */
936 void *kmalloc_order(size_t size, gfp_t flags, unsigned int order)
937 {
938 	void *ret = NULL;
939 	struct page *page;
940 
941 	if (unlikely(flags & GFP_SLAB_BUG_MASK))
942 		flags = kmalloc_fix_flags(flags);
943 
944 	flags |= __GFP_COMP;
945 	page = alloc_pages(flags, order);
946 	if (likely(page)) {
947 		ret = page_address(page);
948 		mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B,
949 				      PAGE_SIZE << order);
950 	}
951 	ret = kasan_kmalloc_large(ret, size, flags);
952 	/* As ret might get tagged, call kmemleak hook after KASAN. */
953 	kmemleak_alloc(ret, size, 1, flags);
954 	return ret;
955 }
956 EXPORT_SYMBOL(kmalloc_order);
957 
958 #ifdef CONFIG_TRACING
959 void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
960 {
961 	void *ret = kmalloc_order(size, flags, order);
962 	trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
963 	return ret;
964 }
965 EXPORT_SYMBOL(kmalloc_order_trace);
966 #endif
967 
968 #ifdef CONFIG_SLAB_FREELIST_RANDOM
969 /* Randomize a generic freelist */
970 static void freelist_randomize(struct rnd_state *state, unsigned int *list,
971 			       unsigned int count)
972 {
973 	unsigned int rand;
974 	unsigned int i;
975 
976 	for (i = 0; i < count; i++)
977 		list[i] = i;
978 
979 	/* Fisher-Yates shuffle */
980 	for (i = count - 1; i > 0; i--) {
981 		rand = prandom_u32_state(state);
982 		rand %= (i + 1);
983 		swap(list[i], list[rand]);
984 	}
985 }
986 
987 /* Create a random sequence per cache */
988 int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
989 				    gfp_t gfp)
990 {
991 	struct rnd_state state;
992 
993 	if (count < 2 || cachep->random_seq)
994 		return 0;
995 
996 	cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp);
997 	if (!cachep->random_seq)
998 		return -ENOMEM;
999 
1000 	/* Get best entropy at this stage of boot */
1001 	prandom_seed_state(&state, get_random_long());
1002 
1003 	freelist_randomize(&state, cachep->random_seq, count);
1004 	return 0;
1005 }
1006 
1007 /* Destroy the per-cache random freelist sequence */
1008 void cache_random_seq_destroy(struct kmem_cache *cachep)
1009 {
1010 	kfree(cachep->random_seq);
1011 	cachep->random_seq = NULL;
1012 }
1013 #endif /* CONFIG_SLAB_FREELIST_RANDOM */
1014 
1015 #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)
1016 #ifdef CONFIG_SLAB
1017 #define SLABINFO_RIGHTS (0600)
1018 #else
1019 #define SLABINFO_RIGHTS (0400)
1020 #endif
1021 
1022 static void print_slabinfo_header(struct seq_file *m)
1023 {
1024 	/*
1025 	 * Output format version, so at least we can change it
1026 	 * without _too_ many complaints.
1027 	 */
1028 #ifdef CONFIG_DEBUG_SLAB
1029 	seq_puts(m, "slabinfo - version: 2.1 (statistics)\n");
1030 #else
1031 	seq_puts(m, "slabinfo - version: 2.1\n");
1032 #endif
1033 	seq_puts(m, "# name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>");
1034 	seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
1035 	seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
1036 #ifdef CONFIG_DEBUG_SLAB
1037 	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
1038 	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
1039 #endif
1040 	seq_putc(m, '\n');
1041 }
1042 
1043 void *slab_start(struct seq_file *m, loff_t *pos)
1044 {
1045 	mutex_lock(&slab_mutex);
1046 	return seq_list_start(&slab_caches, *pos);
1047 }
1048 
1049 void *slab_next(struct seq_file *m, void *p, loff_t *pos)
1050 {
1051 	return seq_list_next(p, &slab_caches, pos);
1052 }
1053 
1054 void slab_stop(struct seq_file *m, void *p)
1055 {
1056 	mutex_unlock(&slab_mutex);
1057 }
1058 
1059 static void cache_show(struct kmem_cache *s, struct seq_file *m)
1060 {
1061 	struct slabinfo sinfo;
1062 
1063 	memset(&sinfo, 0, sizeof(sinfo));
1064 	get_slabinfo(s, &sinfo);
1065 
1066 	seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d",
1067 		   s->name, sinfo.active_objs, sinfo.num_objs, s->size,
1068 		   sinfo.objects_per_slab, (1 << sinfo.cache_order));
1069 
1070 	seq_printf(m, " : tunables %4u %4u %4u",
1071 		   sinfo.limit, sinfo.batchcount, sinfo.shared);
1072 	seq_printf(m, " : slabdata %6lu %6lu %6lu",
1073 		   sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail);
1074 	slabinfo_show_stats(m, s);
1075 	seq_putc(m, '\n');
1076 }
1077 
1078 static int slab_show(struct seq_file *m, void *p)
1079 {
1080 	struct kmem_cache *s = list_entry(p, struct kmem_cache, list);
1081 
1082 	if (p == slab_caches.next)
1083 		print_slabinfo_header(m);
1084 	cache_show(s, m);
1085 	return 0;
1086 }
1087 
1088 void dump_unreclaimable_slab(void)
1089 {
1090 	struct kmem_cache *s;
1091 	struct slabinfo sinfo;
1092 
1093 	/*
1094 	 * Here acquiring slab_mutex is risky since we don't prefer to get
1095 	 * sleep in oom path. But, without mutex hold, it may introduce a
1096 	 * risk of crash.
1097 	 * Use mutex_trylock to protect the list traverse, dump nothing
1098 	 * without acquiring the mutex.
1099 	 */
1100 	if (!mutex_trylock(&slab_mutex)) {
1101 		pr_warn("excessive unreclaimable slab but cannot dump stats\n");
1102 		return;
1103 	}
1104 
1105 	pr_info("Unreclaimable slab info:\n");
1106 	pr_info("Name                      Used          Total\n");
1107 
1108 	list_for_each_entry(s, &slab_caches, list) {
1109 		if (s->flags & SLAB_RECLAIM_ACCOUNT)
1110 			continue;
1111 
1112 		get_slabinfo(s, &sinfo);
1113 
1114 		if (sinfo.num_objs > 0)
1115 			pr_info("%-17s %10luKB %10luKB\n", s->name,
1116 				(sinfo.active_objs * s->size) / 1024,
1117 				(sinfo.num_objs * s->size) / 1024);
1118 	}
1119 	mutex_unlock(&slab_mutex);
1120 }
1121 
1122 #if defined(CONFIG_MEMCG_KMEM)
1123 int memcg_slab_show(struct seq_file *m, void *p)
1124 {
1125 	/*
1126 	 * Deprecated.
1127 	 * Please, take a look at tools/cgroup/slabinfo.py .
1128 	 */
1129 	return 0;
1130 }
1131 #endif
1132 
1133 /*
1134  * slabinfo_op - iterator that generates /proc/slabinfo
1135  *
1136  * Output layout:
1137  * cache-name
1138  * num-active-objs
1139  * total-objs
1140  * object size
1141  * num-active-slabs
1142  * total-slabs
1143  * num-pages-per-slab
1144  * + further values on SMP and with statistics enabled
1145  */
1146 static const struct seq_operations slabinfo_op = {
1147 	.start = slab_start,
1148 	.next = slab_next,
1149 	.stop = slab_stop,
1150 	.show = slab_show,
1151 };
1152 
1153 static int slabinfo_open(struct inode *inode, struct file *file)
1154 {
1155 	return seq_open(file, &slabinfo_op);
1156 }
1157 
1158 static const struct proc_ops slabinfo_proc_ops = {
1159 	.proc_flags	= PROC_ENTRY_PERMANENT,
1160 	.proc_open	= slabinfo_open,
1161 	.proc_read	= seq_read,
1162 	.proc_write	= slabinfo_write,
1163 	.proc_lseek	= seq_lseek,
1164 	.proc_release	= seq_release,
1165 };
1166 
1167 static int __init slab_proc_init(void)
1168 {
1169 	proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops);
1170 	return 0;
1171 }
1172 module_init(slab_proc_init);
1173 
1174 #endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */
1175 
1176 static __always_inline void *__do_krealloc(const void *p, size_t new_size,
1177 					   gfp_t flags)
1178 {
1179 	void *ret;
1180 	size_t ks;
1181 
1182 	/* Don't use instrumented ksize to allow precise KASAN poisoning. */
1183 	if (likely(!ZERO_OR_NULL_PTR(p))) {
1184 		if (!kasan_check_byte(p))
1185 			return NULL;
1186 		ks = kfence_ksize(p) ?: __ksize(p);
1187 	} else
1188 		ks = 0;
1189 
1190 	/* If the object still fits, repoison it precisely. */
1191 	if (ks >= new_size) {
1192 		p = kasan_krealloc((void *)p, new_size, flags);
1193 		return (void *)p;
1194 	}
1195 
1196 	ret = kmalloc_track_caller(new_size, flags);
1197 	if (ret && p) {
1198 		/* Disable KASAN checks as the object's redzone is accessed. */
1199 		kasan_disable_current();
1200 		memcpy(ret, kasan_reset_tag(p), ks);
1201 		kasan_enable_current();
1202 	}
1203 
1204 	return ret;
1205 }
1206 
1207 /**
1208  * krealloc - reallocate memory. The contents will remain unchanged.
1209  * @p: object to reallocate memory for.
1210  * @new_size: how many bytes of memory are required.
1211  * @flags: the type of memory to allocate.
1212  *
1213  * The contents of the object pointed to are preserved up to the
1214  * lesser of the new and old sizes (__GFP_ZERO flag is effectively ignored).
1215  * If @p is %NULL, krealloc() behaves exactly like kmalloc().  If @new_size
1216  * is 0 and @p is not a %NULL pointer, the object pointed to is freed.
1217  *
1218  * Return: pointer to the allocated memory or %NULL in case of error
1219  */
1220 void *krealloc(const void *p, size_t new_size, gfp_t flags)
1221 {
1222 	void *ret;
1223 
1224 	if (unlikely(!new_size)) {
1225 		kfree(p);
1226 		return ZERO_SIZE_PTR;
1227 	}
1228 
1229 	ret = __do_krealloc(p, new_size, flags);
1230 	if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret))
1231 		kfree(p);
1232 
1233 	return ret;
1234 }
1235 EXPORT_SYMBOL(krealloc);
1236 
1237 /**
1238  * kfree_sensitive - Clear sensitive information in memory before freeing
1239  * @p: object to free memory of
1240  *
1241  * The memory of the object @p points to is zeroed before freed.
1242  * If @p is %NULL, kfree_sensitive() does nothing.
1243  *
1244  * Note: this function zeroes the whole allocated buffer which can be a good
1245  * deal bigger than the requested buffer size passed to kmalloc(). So be
1246  * careful when using this function in performance sensitive code.
1247  */
1248 void kfree_sensitive(const void *p)
1249 {
1250 	size_t ks;
1251 	void *mem = (void *)p;
1252 
1253 	ks = ksize(mem);
1254 	if (ks)
1255 		memzero_explicit(mem, ks);
1256 	kfree(mem);
1257 }
1258 EXPORT_SYMBOL(kfree_sensitive);
1259 
1260 /**
1261  * ksize - get the actual amount of memory allocated for a given object
1262  * @objp: Pointer to the object
1263  *
1264  * kmalloc may internally round up allocations and return more memory
1265  * than requested. ksize() can be used to determine the actual amount of
1266  * memory allocated. The caller may use this additional memory, even though
1267  * a smaller amount of memory was initially specified with the kmalloc call.
1268  * The caller must guarantee that objp points to a valid object previously
1269  * allocated with either kmalloc() or kmem_cache_alloc(). The object
1270  * must not be freed during the duration of the call.
1271  *
1272  * Return: size of the actual memory used by @objp in bytes
1273  */
1274 size_t ksize(const void *objp)
1275 {
1276 	size_t size;
1277 
1278 	/*
1279 	 * We need to first check that the pointer to the object is valid, and
1280 	 * only then unpoison the memory. The report printed from ksize() is
1281 	 * more useful, then when it's printed later when the behaviour could
1282 	 * be undefined due to a potential use-after-free or double-free.
1283 	 *
1284 	 * We use kasan_check_byte(), which is supported for the hardware
1285 	 * tag-based KASAN mode, unlike kasan_check_read/write().
1286 	 *
1287 	 * If the pointed to memory is invalid, we return 0 to avoid users of
1288 	 * ksize() writing to and potentially corrupting the memory region.
1289 	 *
1290 	 * We want to perform the check before __ksize(), to avoid potentially
1291 	 * crashing in __ksize() due to accessing invalid metadata.
1292 	 */
1293 	if (unlikely(ZERO_OR_NULL_PTR(objp)) || !kasan_check_byte(objp))
1294 		return 0;
1295 
1296 	size = kfence_ksize(objp) ?: __ksize(objp);
1297 	/*
1298 	 * We assume that ksize callers could use whole allocated area,
1299 	 * so we need to unpoison this area.
1300 	 */
1301 	kasan_unpoison_range(objp, size);
1302 	return size;
1303 }
1304 EXPORT_SYMBOL(ksize);
1305 
1306 /* Tracepoints definitions. */
1307 EXPORT_TRACEPOINT_SYMBOL(kmalloc);
1308 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
1309 EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
1310 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
1311 EXPORT_TRACEPOINT_SYMBOL(kfree);
1312 EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
1313 
1314 int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
1315 {
1316 	if (__should_failslab(s, gfpflags))
1317 		return -ENOMEM;
1318 	return 0;
1319 }
1320 ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
1321