Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
039363f3 CL |
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> | |
1c99ba29 | 13 | #include <linux/cache.h> |
039363f3 | 14 | #include <linux/compiler.h> |
d3fb45f3 | 15 | #include <linux/kfence.h> |
039363f3 | 16 | #include <linux/module.h> |
20cea968 CL |
17 | #include <linux/cpu.h> |
18 | #include <linux/uaccess.h> | |
b7454ad3 GC |
19 | #include <linux/seq_file.h> |
20 | #include <linux/proc_fs.h> | |
fcf8a1e4 | 21 | #include <linux/debugfs.h> |
e86f8b09 | 22 | #include <linux/kasan.h> |
039363f3 CL |
23 | #include <asm/cacheflush.h> |
24 | #include <asm/tlbflush.h> | |
25 | #include <asm/page.h> | |
2633d7a0 | 26 | #include <linux/memcontrol.h> |
5cf909c5 | 27 | #include <linux/stackdepot.h> |
928cec9c | 28 | |
44405099 | 29 | #include "internal.h" |
97d06609 CL |
30 | #include "slab.h" |
31 | ||
b347aa7b VA |
32 | #define CREATE_TRACE_POINTS |
33 | #include <trace/events/kmem.h> | |
34 | ||
97d06609 | 35 | enum slab_state slab_state; |
18004c5d CL |
36 | LIST_HEAD(slab_caches); |
37 | DEFINE_MUTEX(slab_mutex); | |
9b030cb8 | 38 | struct kmem_cache *kmem_cache; |
97d06609 | 39 | |
657dc2f9 TH |
40 | static LIST_HEAD(slab_caches_to_rcu_destroy); |
41 | static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work); | |
42 | static DECLARE_WORK(slab_caches_to_rcu_destroy_work, | |
43 | slab_caches_to_rcu_destroy_workfn); | |
44 | ||
423c929c JK |
45 | /* |
46 | * Set of flags that will prevent slab merging | |
47 | */ | |
48 | #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
5f0d5a3a | 49 | SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ |
e86f8b09 | 50 | SLAB_FAILSLAB | kasan_never_merge()) |
423c929c | 51 | |
230e9fc2 | 52 | #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ |
6d6ea1e9 | 53 | SLAB_CACHE_DMA32 | SLAB_ACCOUNT) |
423c929c JK |
54 | |
55 | /* | |
56 | * Merge control. If this is set then no merging of slab caches will occur. | |
423c929c | 57 | */ |
7660a6fd | 58 | static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT); |
423c929c JK |
59 | |
60 | static int __init setup_slab_nomerge(char *str) | |
61 | { | |
7660a6fd | 62 | slab_nomerge = true; |
423c929c JK |
63 | return 1; |
64 | } | |
65 | ||
82edd9d5 RA |
66 | static int __init setup_slab_merge(char *str) |
67 | { | |
68 | slab_nomerge = false; | |
69 | return 1; | |
70 | } | |
71 | ||
423c929c JK |
72 | #ifdef CONFIG_SLUB |
73 | __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0); | |
82edd9d5 | 74 | __setup_param("slub_merge", slub_merge, setup_slab_merge, 0); |
423c929c JK |
75 | #endif |
76 | ||
77 | __setup("slab_nomerge", setup_slab_nomerge); | |
82edd9d5 | 78 | __setup("slab_merge", setup_slab_merge); |
423c929c | 79 | |
07f361b2 JK |
80 | /* |
81 | * Determine the size of a slab object | |
82 | */ | |
83 | unsigned int kmem_cache_size(struct kmem_cache *s) | |
84 | { | |
85 | return s->object_size; | |
86 | } | |
87 | EXPORT_SYMBOL(kmem_cache_size); | |
88 | ||
77be4b13 | 89 | #ifdef CONFIG_DEBUG_VM |
f4957d5b | 90 | static int kmem_cache_sanity_check(const char *name, unsigned int size) |
039363f3 | 91 | { |
74c1d3e0 | 92 | if (!name || in_interrupt() || size > KMALLOC_MAX_SIZE) { |
77be4b13 SK |
93 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); |
94 | return -EINVAL; | |
039363f3 | 95 | } |
b920536a | 96 | |
20cea968 | 97 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ |
77be4b13 SK |
98 | return 0; |
99 | } | |
100 | #else | |
f4957d5b | 101 | static inline int kmem_cache_sanity_check(const char *name, unsigned int size) |
77be4b13 SK |
102 | { |
103 | return 0; | |
104 | } | |
20cea968 CL |
105 | #endif |
106 | ||
692ae74a BL |
107 | /* |
108 | * Figure out what the alignment of the objects will be given a set of | |
109 | * flags, a user specified alignment and the size of the objects. | |
110 | */ | |
f4957d5b AD |
111 | static unsigned int calculate_alignment(slab_flags_t flags, |
112 | unsigned int align, unsigned int size) | |
692ae74a BL |
113 | { |
114 | /* | |
115 | * If the user wants hardware cache aligned objects then follow that | |
116 | * suggestion if the object is sufficiently large. | |
117 | * | |
118 | * The hardware cache alignment cannot override the specified | |
119 | * alignment though. If that is greater then use it. | |
120 | */ | |
121 | if (flags & SLAB_HWCACHE_ALIGN) { | |
f4957d5b | 122 | unsigned int ralign; |
692ae74a BL |
123 | |
124 | ralign = cache_line_size(); | |
125 | while (size <= ralign / 2) | |
126 | ralign /= 2; | |
127 | align = max(align, ralign); | |
128 | } | |
129 | ||
d949a815 | 130 | align = max(align, arch_slab_minalign()); |
692ae74a BL |
131 | |
132 | return ALIGN(align, sizeof(void *)); | |
133 | } | |
134 | ||
423c929c JK |
135 | /* |
136 | * Find a mergeable slab cache | |
137 | */ | |
138 | int slab_unmergeable(struct kmem_cache *s) | |
139 | { | |
140 | if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) | |
141 | return 1; | |
142 | ||
423c929c JK |
143 | if (s->ctor) |
144 | return 1; | |
145 | ||
8eb8284b DW |
146 | if (s->usersize) |
147 | return 1; | |
148 | ||
423c929c JK |
149 | /* |
150 | * We may have set a slab to be unmergeable during bootstrap. | |
151 | */ | |
152 | if (s->refcount < 0) | |
153 | return 1; | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
f4957d5b | 158 | struct kmem_cache *find_mergeable(unsigned int size, unsigned int align, |
d50112ed | 159 | slab_flags_t flags, const char *name, void (*ctor)(void *)) |
423c929c JK |
160 | { |
161 | struct kmem_cache *s; | |
162 | ||
c6e28895 | 163 | if (slab_nomerge) |
423c929c JK |
164 | return NULL; |
165 | ||
166 | if (ctor) | |
167 | return NULL; | |
168 | ||
169 | size = ALIGN(size, sizeof(void *)); | |
170 | align = calculate_alignment(flags, align, size); | |
171 | size = ALIGN(size, align); | |
37540008 | 172 | flags = kmem_cache_flags(size, flags, name); |
423c929c | 173 | |
c6e28895 GM |
174 | if (flags & SLAB_NEVER_MERGE) |
175 | return NULL; | |
176 | ||
c7094406 | 177 | list_for_each_entry_reverse(s, &slab_caches, list) { |
423c929c JK |
178 | if (slab_unmergeable(s)) |
179 | continue; | |
180 | ||
181 | if (size > s->size) | |
182 | continue; | |
183 | ||
184 | if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) | |
185 | continue; | |
186 | /* | |
187 | * Check if alignment is compatible. | |
188 | * Courtesy of Adrian Drzewiecki | |
189 | */ | |
190 | if ((s->size & ~(align - 1)) != s->size) | |
191 | continue; | |
192 | ||
193 | if (s->size - size >= sizeof(void *)) | |
194 | continue; | |
195 | ||
95069ac8 JK |
196 | if (IS_ENABLED(CONFIG_SLAB) && align && |
197 | (align > s->align || s->align % align)) | |
198 | continue; | |
199 | ||
423c929c JK |
200 | return s; |
201 | } | |
202 | return NULL; | |
203 | } | |
204 | ||
c9a77a79 | 205 | static struct kmem_cache *create_cache(const char *name, |
613a5eb5 | 206 | unsigned int object_size, unsigned int align, |
7bbdb81e AD |
207 | slab_flags_t flags, unsigned int useroffset, |
208 | unsigned int usersize, void (*ctor)(void *), | |
9855609b | 209 | struct kmem_cache *root_cache) |
794b1248 VD |
210 | { |
211 | struct kmem_cache *s; | |
212 | int err; | |
213 | ||
8eb8284b DW |
214 | if (WARN_ON(useroffset + usersize > object_size)) |
215 | useroffset = usersize = 0; | |
216 | ||
794b1248 VD |
217 | err = -ENOMEM; |
218 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); | |
219 | if (!s) | |
220 | goto out; | |
221 | ||
222 | s->name = name; | |
613a5eb5 | 223 | s->size = s->object_size = object_size; |
794b1248 VD |
224 | s->align = align; |
225 | s->ctor = ctor; | |
8eb8284b DW |
226 | s->useroffset = useroffset; |
227 | s->usersize = usersize; | |
794b1248 | 228 | |
794b1248 VD |
229 | err = __kmem_cache_create(s, flags); |
230 | if (err) | |
231 | goto out_free_cache; | |
232 | ||
233 | s->refcount = 1; | |
234 | list_add(&s->list, &slab_caches); | |
794b1248 VD |
235 | out: |
236 | if (err) | |
237 | return ERR_PTR(err); | |
238 | return s; | |
239 | ||
240 | out_free_cache: | |
7c4da061 | 241 | kmem_cache_free(kmem_cache, s); |
794b1248 VD |
242 | goto out; |
243 | } | |
45906855 | 244 | |
f496990f MR |
245 | /** |
246 | * kmem_cache_create_usercopy - Create a cache with a region suitable | |
247 | * for copying to userspace | |
77be4b13 SK |
248 | * @name: A string which is used in /proc/slabinfo to identify this cache. |
249 | * @size: The size of objects to be created in this cache. | |
250 | * @align: The required alignment for the objects. | |
251 | * @flags: SLAB flags | |
8eb8284b DW |
252 | * @useroffset: Usercopy region offset |
253 | * @usersize: Usercopy region size | |
77be4b13 SK |
254 | * @ctor: A constructor for the objects. |
255 | * | |
77be4b13 SK |
256 | * Cannot be called within a interrupt, but can be interrupted. |
257 | * The @ctor is run when new pages are allocated by the cache. | |
258 | * | |
259 | * The flags are | |
260 | * | |
261 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
262 | * to catch references to uninitialised memory. | |
263 | * | |
f496990f | 264 | * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check |
77be4b13 SK |
265 | * for buffer overruns. |
266 | * | |
267 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
268 | * cacheline. This can be beneficial if you're counting cycles as closely | |
269 | * as davem. | |
f496990f MR |
270 | * |
271 | * Return: a pointer to the cache on success, NULL on failure. | |
77be4b13 | 272 | */ |
2633d7a0 | 273 | struct kmem_cache * |
f4957d5b AD |
274 | kmem_cache_create_usercopy(const char *name, |
275 | unsigned int size, unsigned int align, | |
7bbdb81e AD |
276 | slab_flags_t flags, |
277 | unsigned int useroffset, unsigned int usersize, | |
8eb8284b | 278 | void (*ctor)(void *)) |
77be4b13 | 279 | { |
40911a79 | 280 | struct kmem_cache *s = NULL; |
3dec16ea | 281 | const char *cache_name; |
3965fc36 | 282 | int err; |
039363f3 | 283 | |
afe0c26d VB |
284 | #ifdef CONFIG_SLUB_DEBUG |
285 | /* | |
286 | * If no slub_debug was enabled globally, the static key is not yet | |
287 | * enabled by setup_slub_debug(). Enable it if the cache is being | |
288 | * created with any of the debugging flags passed explicitly. | |
5cf909c5 OG |
289 | * It's also possible that this is the first cache created with |
290 | * SLAB_STORE_USER and we should init stack_depot for it. | |
afe0c26d VB |
291 | */ |
292 | if (flags & SLAB_DEBUG_FLAGS) | |
293 | static_branch_enable(&slub_debug_enabled); | |
5cf909c5 OG |
294 | if (flags & SLAB_STORE_USER) |
295 | stack_depot_init(); | |
afe0c26d VB |
296 | #endif |
297 | ||
77be4b13 | 298 | mutex_lock(&slab_mutex); |
686d550d | 299 | |
794b1248 | 300 | err = kmem_cache_sanity_check(name, size); |
3aa24f51 | 301 | if (err) { |
3965fc36 | 302 | goto out_unlock; |
3aa24f51 | 303 | } |
686d550d | 304 | |
e70954fd TG |
305 | /* Refuse requests with allocator specific flags */ |
306 | if (flags & ~SLAB_FLAGS_PERMITTED) { | |
307 | err = -EINVAL; | |
308 | goto out_unlock; | |
309 | } | |
310 | ||
d8843922 GC |
311 | /* |
312 | * Some allocators will constraint the set of valid flags to a subset | |
313 | * of all flags. We expect them to define CACHE_CREATE_MASK in this | |
314 | * case, and we'll just provide them with a sanitized version of the | |
315 | * passed flags. | |
316 | */ | |
317 | flags &= CACHE_CREATE_MASK; | |
686d550d | 318 | |
8eb8284b DW |
319 | /* Fail closed on bad usersize of useroffset values. */ |
320 | if (WARN_ON(!usersize && useroffset) || | |
321 | WARN_ON(size < usersize || size - usersize < useroffset)) | |
322 | usersize = useroffset = 0; | |
323 | ||
324 | if (!usersize) | |
325 | s = __kmem_cache_alias(name, size, align, flags, ctor); | |
794b1248 | 326 | if (s) |
3965fc36 | 327 | goto out_unlock; |
2633d7a0 | 328 | |
3dec16ea | 329 | cache_name = kstrdup_const(name, GFP_KERNEL); |
794b1248 VD |
330 | if (!cache_name) { |
331 | err = -ENOMEM; | |
332 | goto out_unlock; | |
333 | } | |
7c9adf5a | 334 | |
613a5eb5 | 335 | s = create_cache(cache_name, size, |
c9a77a79 | 336 | calculate_alignment(flags, align, size), |
9855609b | 337 | flags, useroffset, usersize, ctor, NULL); |
794b1248 VD |
338 | if (IS_ERR(s)) { |
339 | err = PTR_ERR(s); | |
3dec16ea | 340 | kfree_const(cache_name); |
794b1248 | 341 | } |
3965fc36 VD |
342 | |
343 | out_unlock: | |
20cea968 | 344 | mutex_unlock(&slab_mutex); |
03afc0e2 | 345 | |
ba3253c7 | 346 | if (err) { |
686d550d | 347 | if (flags & SLAB_PANIC) |
4acaa7d5 | 348 | panic("%s: Failed to create slab '%s'. Error %d\n", |
349 | __func__, name, err); | |
686d550d | 350 | else { |
4acaa7d5 | 351 | pr_warn("%s(%s) failed with error %d\n", |
352 | __func__, name, err); | |
686d550d CL |
353 | dump_stack(); |
354 | } | |
686d550d CL |
355 | return NULL; |
356 | } | |
039363f3 CL |
357 | return s; |
358 | } | |
8eb8284b DW |
359 | EXPORT_SYMBOL(kmem_cache_create_usercopy); |
360 | ||
f496990f MR |
361 | /** |
362 | * kmem_cache_create - Create a cache. | |
363 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
364 | * @size: The size of objects to be created in this cache. | |
365 | * @align: The required alignment for the objects. | |
366 | * @flags: SLAB flags | |
367 | * @ctor: A constructor for the objects. | |
368 | * | |
369 | * Cannot be called within a interrupt, but can be interrupted. | |
370 | * The @ctor is run when new pages are allocated by the cache. | |
371 | * | |
372 | * The flags are | |
373 | * | |
374 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
375 | * to catch references to uninitialised memory. | |
376 | * | |
377 | * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check | |
378 | * for buffer overruns. | |
379 | * | |
380 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
381 | * cacheline. This can be beneficial if you're counting cycles as closely | |
382 | * as davem. | |
383 | * | |
384 | * Return: a pointer to the cache on success, NULL on failure. | |
385 | */ | |
8eb8284b | 386 | struct kmem_cache * |
f4957d5b | 387 | kmem_cache_create(const char *name, unsigned int size, unsigned int align, |
8eb8284b DW |
388 | slab_flags_t flags, void (*ctor)(void *)) |
389 | { | |
6d07d1cd | 390 | return kmem_cache_create_usercopy(name, size, align, flags, 0, 0, |
8eb8284b DW |
391 | ctor); |
392 | } | |
794b1248 | 393 | EXPORT_SYMBOL(kmem_cache_create); |
2633d7a0 | 394 | |
0495e337 WL |
395 | #ifdef SLAB_SUPPORTS_SYSFS |
396 | /* | |
397 | * For a given kmem_cache, kmem_cache_destroy() should only be called | |
398 | * once or there will be a use-after-free problem. The actual deletion | |
399 | * and release of the kobject does not need slab_mutex or cpu_hotplug_lock | |
400 | * protection. So they are now done without holding those locks. | |
401 | * | |
402 | * Note that there will be a slight delay in the deletion of sysfs files | |
403 | * if kmem_cache_release() is called indrectly from a work function. | |
404 | */ | |
405 | static void kmem_cache_release(struct kmem_cache *s) | |
406 | { | |
407 | sysfs_slab_unlink(s); | |
408 | sysfs_slab_release(s); | |
409 | } | |
410 | #else | |
411 | static void kmem_cache_release(struct kmem_cache *s) | |
412 | { | |
413 | slab_kmem_cache_release(s); | |
414 | } | |
415 | #endif | |
416 | ||
657dc2f9 | 417 | static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work) |
d5b3cf71 | 418 | { |
657dc2f9 TH |
419 | LIST_HEAD(to_destroy); |
420 | struct kmem_cache *s, *s2; | |
d5b3cf71 | 421 | |
657dc2f9 | 422 | /* |
5f0d5a3a | 423 | * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the |
657dc2f9 | 424 | * @slab_caches_to_rcu_destroy list. The slab pages are freed |
081a06fa | 425 | * through RCU and the associated kmem_cache are dereferenced |
657dc2f9 TH |
426 | * while freeing the pages, so the kmem_caches should be freed only |
427 | * after the pending RCU operations are finished. As rcu_barrier() | |
428 | * is a pretty slow operation, we batch all pending destructions | |
429 | * asynchronously. | |
430 | */ | |
431 | mutex_lock(&slab_mutex); | |
432 | list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy); | |
433 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 434 | |
657dc2f9 TH |
435 | if (list_empty(&to_destroy)) |
436 | return; | |
437 | ||
438 | rcu_barrier(); | |
439 | ||
440 | list_for_each_entry_safe(s, s2, &to_destroy, list) { | |
64dd6849 | 441 | debugfs_slab_release(s); |
d3fb45f3 | 442 | kfence_shutdown_cache(s); |
0495e337 | 443 | kmem_cache_release(s); |
657dc2f9 | 444 | } |
d5b3cf71 VD |
445 | } |
446 | ||
657dc2f9 | 447 | static int shutdown_cache(struct kmem_cache *s) |
d5b3cf71 | 448 | { |
f9fa1d91 GT |
449 | /* free asan quarantined objects */ |
450 | kasan_cache_shutdown(s); | |
451 | ||
657dc2f9 TH |
452 | if (__kmem_cache_shutdown(s) != 0) |
453 | return -EBUSY; | |
d5b3cf71 | 454 | |
657dc2f9 | 455 | list_del(&s->list); |
d5b3cf71 | 456 | |
5f0d5a3a | 457 | if (s->flags & SLAB_TYPESAFE_BY_RCU) { |
657dc2f9 TH |
458 | list_add_tail(&s->list, &slab_caches_to_rcu_destroy); |
459 | schedule_work(&slab_caches_to_rcu_destroy_work); | |
460 | } else { | |
d3fb45f3 | 461 | kfence_shutdown_cache(s); |
64dd6849 | 462 | debugfs_slab_release(s); |
d5b3cf71 | 463 | } |
657dc2f9 TH |
464 | |
465 | return 0; | |
d5b3cf71 VD |
466 | } |
467 | ||
41a21285 CL |
468 | void slab_kmem_cache_release(struct kmem_cache *s) |
469 | { | |
52b4b950 | 470 | __kmem_cache_release(s); |
3dec16ea | 471 | kfree_const(s->name); |
41a21285 CL |
472 | kmem_cache_free(kmem_cache, s); |
473 | } | |
474 | ||
945cf2b6 CL |
475 | void kmem_cache_destroy(struct kmem_cache *s) |
476 | { | |
0495e337 | 477 | int refcnt; |
d71608a8 | 478 | bool rcu_set; |
0495e337 | 479 | |
bed0a9b5 | 480 | if (unlikely(!s) || !kasan_check_byte(s)) |
3942d299 SS |
481 | return; |
482 | ||
5a836bf6 | 483 | cpus_read_lock(); |
945cf2b6 | 484 | mutex_lock(&slab_mutex); |
b8529907 | 485 | |
d71608a8 FT |
486 | rcu_set = s->flags & SLAB_TYPESAFE_BY_RCU; |
487 | ||
0495e337 WL |
488 | refcnt = --s->refcount; |
489 | if (refcnt) | |
b8529907 VD |
490 | goto out_unlock; |
491 | ||
7302e91f ME |
492 | WARN(shutdown_cache(s), |
493 | "%s %s: Slab cache still has objects when called from %pS", | |
494 | __func__, s->name, (void *)_RET_IP_); | |
b8529907 VD |
495 | out_unlock: |
496 | mutex_unlock(&slab_mutex); | |
5a836bf6 | 497 | cpus_read_unlock(); |
d71608a8 | 498 | if (!refcnt && !rcu_set) |
0495e337 | 499 | kmem_cache_release(s); |
945cf2b6 CL |
500 | } |
501 | EXPORT_SYMBOL(kmem_cache_destroy); | |
502 | ||
03afc0e2 VD |
503 | /** |
504 | * kmem_cache_shrink - Shrink a cache. | |
505 | * @cachep: The cache to shrink. | |
506 | * | |
507 | * Releases as many slabs as possible for a cache. | |
508 | * To help debugging, a zero exit status indicates all slabs were released. | |
a862f68a MR |
509 | * |
510 | * Return: %0 if all slabs were released, non-zero otherwise | |
03afc0e2 VD |
511 | */ |
512 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
513 | { | |
55834c59 | 514 | kasan_cache_shrink(cachep); |
7e1fa93d | 515 | |
610f9c00 | 516 | return __kmem_cache_shrink(cachep); |
03afc0e2 VD |
517 | } |
518 | EXPORT_SYMBOL(kmem_cache_shrink); | |
519 | ||
fda90124 | 520 | bool slab_is_available(void) |
97d06609 CL |
521 | { |
522 | return slab_state >= UP; | |
523 | } | |
b7454ad3 | 524 | |
5bb1bb35 | 525 | #ifdef CONFIG_PRINTK |
8e7f37f2 PM |
526 | /** |
527 | * kmem_valid_obj - does the pointer reference a valid slab object? | |
528 | * @object: pointer to query. | |
529 | * | |
530 | * Return: %true if the pointer is to a not-yet-freed object from | |
531 | * kmalloc() or kmem_cache_alloc(), either %true or %false if the pointer | |
532 | * is to an already-freed object, and %false otherwise. | |
533 | */ | |
534 | bool kmem_valid_obj(void *object) | |
535 | { | |
7213230a | 536 | struct folio *folio; |
8e7f37f2 PM |
537 | |
538 | /* Some arches consider ZERO_SIZE_PTR to be a valid address. */ | |
539 | if (object < (void *)PAGE_SIZE || !virt_addr_valid(object)) | |
540 | return false; | |
7213230a MWO |
541 | folio = virt_to_folio(object); |
542 | return folio_test_slab(folio); | |
8e7f37f2 | 543 | } |
0d3dd2c8 | 544 | EXPORT_SYMBOL_GPL(kmem_valid_obj); |
8e7f37f2 | 545 | |
2dfe63e6 ME |
546 | static void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab) |
547 | { | |
548 | if (__kfence_obj_info(kpp, object, slab)) | |
549 | return; | |
550 | __kmem_obj_info(kpp, object, slab); | |
551 | } | |
552 | ||
8e7f37f2 PM |
553 | /** |
554 | * kmem_dump_obj - Print available slab provenance information | |
555 | * @object: slab object for which to find provenance information. | |
556 | * | |
557 | * This function uses pr_cont(), so that the caller is expected to have | |
558 | * printed out whatever preamble is appropriate. The provenance information | |
559 | * depends on the type of object and on how much debugging is enabled. | |
560 | * For a slab-cache object, the fact that it is a slab object is printed, | |
561 | * and, if available, the slab name, return address, and stack trace from | |
e548eaa1 | 562 | * the allocation and last free path of that object. |
8e7f37f2 PM |
563 | * |
564 | * This function will splat if passed a pointer to a non-slab object. | |
565 | * If you are not sure what type of object you have, you should instead | |
566 | * use mem_dump_obj(). | |
567 | */ | |
568 | void kmem_dump_obj(void *object) | |
569 | { | |
570 | char *cp = IS_ENABLED(CONFIG_MMU) ? "" : "/vmalloc"; | |
571 | int i; | |
7213230a | 572 | struct slab *slab; |
8e7f37f2 PM |
573 | unsigned long ptroffset; |
574 | struct kmem_obj_info kp = { }; | |
575 | ||
576 | if (WARN_ON_ONCE(!virt_addr_valid(object))) | |
577 | return; | |
7213230a MWO |
578 | slab = virt_to_slab(object); |
579 | if (WARN_ON_ONCE(!slab)) { | |
8e7f37f2 PM |
580 | pr_cont(" non-slab memory.\n"); |
581 | return; | |
582 | } | |
7213230a | 583 | kmem_obj_info(&kp, object, slab); |
8e7f37f2 PM |
584 | if (kp.kp_slab_cache) |
585 | pr_cont(" slab%s %s", cp, kp.kp_slab_cache->name); | |
586 | else | |
587 | pr_cont(" slab%s", cp); | |
2dfe63e6 ME |
588 | if (is_kfence_address(object)) |
589 | pr_cont(" (kfence)"); | |
8e7f37f2 PM |
590 | if (kp.kp_objp) |
591 | pr_cont(" start %px", kp.kp_objp); | |
592 | if (kp.kp_data_offset) | |
593 | pr_cont(" data offset %lu", kp.kp_data_offset); | |
594 | if (kp.kp_objp) { | |
595 | ptroffset = ((char *)object - (char *)kp.kp_objp) - kp.kp_data_offset; | |
596 | pr_cont(" pointer offset %lu", ptroffset); | |
597 | } | |
598 | if (kp.kp_slab_cache && kp.kp_slab_cache->usersize) | |
599 | pr_cont(" size %u", kp.kp_slab_cache->usersize); | |
600 | if (kp.kp_ret) | |
601 | pr_cont(" allocated at %pS\n", kp.kp_ret); | |
602 | else | |
603 | pr_cont("\n"); | |
604 | for (i = 0; i < ARRAY_SIZE(kp.kp_stack); i++) { | |
605 | if (!kp.kp_stack[i]) | |
606 | break; | |
607 | pr_info(" %pS\n", kp.kp_stack[i]); | |
608 | } | |
e548eaa1 MS |
609 | |
610 | if (kp.kp_free_stack[0]) | |
611 | pr_cont(" Free path:\n"); | |
612 | ||
613 | for (i = 0; i < ARRAY_SIZE(kp.kp_free_stack); i++) { | |
614 | if (!kp.kp_free_stack[i]) | |
615 | break; | |
616 | pr_info(" %pS\n", kp.kp_free_stack[i]); | |
617 | } | |
618 | ||
8e7f37f2 | 619 | } |
0d3dd2c8 | 620 | EXPORT_SYMBOL_GPL(kmem_dump_obj); |
5bb1bb35 | 621 | #endif |
8e7f37f2 | 622 | |
45530c44 CL |
623 | #ifndef CONFIG_SLOB |
624 | /* Create a cache during boot when no slab services are available yet */ | |
361d575e AD |
625 | void __init create_boot_cache(struct kmem_cache *s, const char *name, |
626 | unsigned int size, slab_flags_t flags, | |
627 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
628 | { |
629 | int err; | |
59bb4798 | 630 | unsigned int align = ARCH_KMALLOC_MINALIGN; |
45530c44 CL |
631 | |
632 | s->name = name; | |
633 | s->size = s->object_size = size; | |
59bb4798 VB |
634 | |
635 | /* | |
636 | * For power of two sizes, guarantee natural alignment for kmalloc | |
637 | * caches, regardless of SL*B debugging options. | |
638 | */ | |
639 | if (is_power_of_2(size)) | |
640 | align = max(align, size); | |
641 | s->align = calculate_alignment(flags, align, size); | |
642 | ||
8eb8284b DW |
643 | s->useroffset = useroffset; |
644 | s->usersize = usersize; | |
f7ce3190 | 645 | |
45530c44 CL |
646 | err = __kmem_cache_create(s, flags); |
647 | ||
648 | if (err) | |
361d575e | 649 | panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n", |
45530c44 CL |
650 | name, size, err); |
651 | ||
652 | s->refcount = -1; /* Exempt from merging for now */ | |
653 | } | |
654 | ||
55de8b9c AD |
655 | struct kmem_cache *__init create_kmalloc_cache(const char *name, |
656 | unsigned int size, slab_flags_t flags, | |
657 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
658 | { |
659 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); | |
660 | ||
661 | if (!s) | |
662 | panic("Out of memory when creating slab %s\n", name); | |
663 | ||
6edf2576 FT |
664 | create_boot_cache(s, name, size, flags | SLAB_KMALLOC, useroffset, |
665 | usersize); | |
92850134 | 666 | kasan_cache_create_kmalloc(s); |
45530c44 CL |
667 | list_add(&s->list, &slab_caches); |
668 | s->refcount = 1; | |
669 | return s; | |
670 | } | |
671 | ||
cc252eae | 672 | struct kmem_cache * |
a07057dc AB |
673 | kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init = |
674 | { /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ }; | |
9425c58e CL |
675 | EXPORT_SYMBOL(kmalloc_caches); |
676 | ||
2c59dd65 CL |
677 | /* |
678 | * Conversion table for small slabs sizes / 8 to the index in the | |
679 | * kmalloc array. This is necessary for slabs < 192 since we have non power | |
680 | * of two cache sizes there. The size of larger slabs can be determined using | |
681 | * fls. | |
682 | */ | |
d5f86655 | 683 | static u8 size_index[24] __ro_after_init = { |
2c59dd65 CL |
684 | 3, /* 8 */ |
685 | 4, /* 16 */ | |
686 | 5, /* 24 */ | |
687 | 5, /* 32 */ | |
688 | 6, /* 40 */ | |
689 | 6, /* 48 */ | |
690 | 6, /* 56 */ | |
691 | 6, /* 64 */ | |
692 | 1, /* 72 */ | |
693 | 1, /* 80 */ | |
694 | 1, /* 88 */ | |
695 | 1, /* 96 */ | |
696 | 7, /* 104 */ | |
697 | 7, /* 112 */ | |
698 | 7, /* 120 */ | |
699 | 7, /* 128 */ | |
700 | 2, /* 136 */ | |
701 | 2, /* 144 */ | |
702 | 2, /* 152 */ | |
703 | 2, /* 160 */ | |
704 | 2, /* 168 */ | |
705 | 2, /* 176 */ | |
706 | 2, /* 184 */ | |
707 | 2 /* 192 */ | |
708 | }; | |
709 | ||
ac914d08 | 710 | static inline unsigned int size_index_elem(unsigned int bytes) |
2c59dd65 CL |
711 | { |
712 | return (bytes - 1) / 8; | |
713 | } | |
714 | ||
715 | /* | |
716 | * Find the kmem_cache structure that serves a given size of | |
717 | * allocation | |
718 | */ | |
719 | struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) | |
720 | { | |
d5f86655 | 721 | unsigned int index; |
2c59dd65 CL |
722 | |
723 | if (size <= 192) { | |
724 | if (!size) | |
725 | return ZERO_SIZE_PTR; | |
726 | ||
727 | index = size_index[size_index_elem(size)]; | |
61448479 | 728 | } else { |
221d7da6 | 729 | if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE)) |
61448479 | 730 | return NULL; |
2c59dd65 | 731 | index = fls(size - 1); |
61448479 | 732 | } |
2c59dd65 | 733 | |
cc252eae | 734 | return kmalloc_caches[kmalloc_type(flags)][index]; |
2c59dd65 CL |
735 | } |
736 | ||
05a94065 KC |
737 | size_t kmalloc_size_roundup(size_t size) |
738 | { | |
739 | struct kmem_cache *c; | |
740 | ||
741 | /* Short-circuit the 0 size case. */ | |
742 | if (unlikely(size == 0)) | |
743 | return 0; | |
744 | /* Short-circuit saturated "too-large" case. */ | |
745 | if (unlikely(size == SIZE_MAX)) | |
746 | return SIZE_MAX; | |
747 | /* Above the smaller buckets, size is a multiple of page size. */ | |
748 | if (size > KMALLOC_MAX_CACHE_SIZE) | |
749 | return PAGE_SIZE << get_order(size); | |
750 | ||
751 | /* The flags don't matter since size_index is common to all. */ | |
752 | c = kmalloc_slab(size, GFP_KERNEL); | |
753 | return c ? c->object_size : 0; | |
754 | } | |
755 | EXPORT_SYMBOL(kmalloc_size_roundup); | |
756 | ||
cb5d9fb3 | 757 | #ifdef CONFIG_ZONE_DMA |
494c1dfe WL |
758 | #define KMALLOC_DMA_NAME(sz) .name[KMALLOC_DMA] = "dma-kmalloc-" #sz, |
759 | #else | |
760 | #define KMALLOC_DMA_NAME(sz) | |
761 | #endif | |
762 | ||
763 | #ifdef CONFIG_MEMCG_KMEM | |
764 | #define KMALLOC_CGROUP_NAME(sz) .name[KMALLOC_CGROUP] = "kmalloc-cg-" #sz, | |
cb5d9fb3 | 765 | #else |
494c1dfe WL |
766 | #define KMALLOC_CGROUP_NAME(sz) |
767 | #endif | |
768 | ||
cb5d9fb3 PL |
769 | #define INIT_KMALLOC_INFO(__size, __short_size) \ |
770 | { \ | |
771 | .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \ | |
772 | .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \ | |
494c1dfe WL |
773 | KMALLOC_CGROUP_NAME(__short_size) \ |
774 | KMALLOC_DMA_NAME(__short_size) \ | |
cb5d9fb3 PL |
775 | .size = __size, \ |
776 | } | |
cb5d9fb3 | 777 | |
4066c33d GG |
778 | /* |
779 | * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time. | |
d6a71648 HY |
780 | * kmalloc_index() supports up to 2^21=2MB, so the final entry of the table is |
781 | * kmalloc-2M. | |
4066c33d | 782 | */ |
af3b5f87 | 783 | const struct kmalloc_info_struct kmalloc_info[] __initconst = { |
cb5d9fb3 PL |
784 | INIT_KMALLOC_INFO(0, 0), |
785 | INIT_KMALLOC_INFO(96, 96), | |
786 | INIT_KMALLOC_INFO(192, 192), | |
787 | INIT_KMALLOC_INFO(8, 8), | |
788 | INIT_KMALLOC_INFO(16, 16), | |
789 | INIT_KMALLOC_INFO(32, 32), | |
790 | INIT_KMALLOC_INFO(64, 64), | |
791 | INIT_KMALLOC_INFO(128, 128), | |
792 | INIT_KMALLOC_INFO(256, 256), | |
793 | INIT_KMALLOC_INFO(512, 512), | |
794 | INIT_KMALLOC_INFO(1024, 1k), | |
795 | INIT_KMALLOC_INFO(2048, 2k), | |
796 | INIT_KMALLOC_INFO(4096, 4k), | |
797 | INIT_KMALLOC_INFO(8192, 8k), | |
798 | INIT_KMALLOC_INFO(16384, 16k), | |
799 | INIT_KMALLOC_INFO(32768, 32k), | |
800 | INIT_KMALLOC_INFO(65536, 64k), | |
801 | INIT_KMALLOC_INFO(131072, 128k), | |
802 | INIT_KMALLOC_INFO(262144, 256k), | |
803 | INIT_KMALLOC_INFO(524288, 512k), | |
804 | INIT_KMALLOC_INFO(1048576, 1M), | |
d6a71648 | 805 | INIT_KMALLOC_INFO(2097152, 2M) |
4066c33d GG |
806 | }; |
807 | ||
f97d5f63 | 808 | /* |
34cc6990 DS |
809 | * Patch up the size_index table if we have strange large alignment |
810 | * requirements for the kmalloc array. This is only the case for | |
811 | * MIPS it seems. The standard arches will not generate any code here. | |
812 | * | |
813 | * Largest permitted alignment is 256 bytes due to the way we | |
814 | * handle the index determination for the smaller caches. | |
815 | * | |
816 | * Make sure that nothing crazy happens if someone starts tinkering | |
817 | * around with ARCH_KMALLOC_MINALIGN | |
f97d5f63 | 818 | */ |
34cc6990 | 819 | void __init setup_kmalloc_cache_index_table(void) |
f97d5f63 | 820 | { |
ac914d08 | 821 | unsigned int i; |
f97d5f63 | 822 | |
2c59dd65 | 823 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || |
7d6b6cc3 | 824 | !is_power_of_2(KMALLOC_MIN_SIZE)); |
2c59dd65 CL |
825 | |
826 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { | |
ac914d08 | 827 | unsigned int elem = size_index_elem(i); |
2c59dd65 CL |
828 | |
829 | if (elem >= ARRAY_SIZE(size_index)) | |
830 | break; | |
831 | size_index[elem] = KMALLOC_SHIFT_LOW; | |
832 | } | |
833 | ||
834 | if (KMALLOC_MIN_SIZE >= 64) { | |
835 | /* | |
0b8f0d87 | 836 | * The 96 byte sized cache is not used if the alignment |
2c59dd65 CL |
837 | * is 64 byte. |
838 | */ | |
839 | for (i = 64 + 8; i <= 96; i += 8) | |
840 | size_index[size_index_elem(i)] = 7; | |
841 | ||
842 | } | |
843 | ||
844 | if (KMALLOC_MIN_SIZE >= 128) { | |
845 | /* | |
846 | * The 192 byte sized cache is not used if the alignment | |
847 | * is 128 byte. Redirect kmalloc to use the 256 byte cache | |
848 | * instead. | |
849 | */ | |
850 | for (i = 128 + 8; i <= 192; i += 8) | |
851 | size_index[size_index_elem(i)] = 8; | |
852 | } | |
34cc6990 DS |
853 | } |
854 | ||
1291523f | 855 | static void __init |
13657d0a | 856 | new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags) |
a9730fca | 857 | { |
494c1dfe | 858 | if (type == KMALLOC_RECLAIM) { |
1291523f | 859 | flags |= SLAB_RECLAIM_ACCOUNT; |
494c1dfe | 860 | } else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) { |
17c17367 | 861 | if (mem_cgroup_kmem_disabled()) { |
494c1dfe WL |
862 | kmalloc_caches[type][idx] = kmalloc_caches[KMALLOC_NORMAL][idx]; |
863 | return; | |
864 | } | |
865 | flags |= SLAB_ACCOUNT; | |
33647783 OK |
866 | } else if (IS_ENABLED(CONFIG_ZONE_DMA) && (type == KMALLOC_DMA)) { |
867 | flags |= SLAB_CACHE_DMA; | |
494c1dfe | 868 | } |
1291523f | 869 | |
cb5d9fb3 PL |
870 | kmalloc_caches[type][idx] = create_kmalloc_cache( |
871 | kmalloc_info[idx].name[type], | |
6c0c21ad DW |
872 | kmalloc_info[idx].size, flags, 0, |
873 | kmalloc_info[idx].size); | |
13e680fb WL |
874 | |
875 | /* | |
876 | * If CONFIG_MEMCG_KMEM is enabled, disable cache merging for | |
877 | * KMALLOC_NORMAL caches. | |
878 | */ | |
879 | if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_NORMAL)) | |
880 | kmalloc_caches[type][idx]->refcount = -1; | |
a9730fca CL |
881 | } |
882 | ||
34cc6990 DS |
883 | /* |
884 | * Create the kmalloc array. Some of the regular kmalloc arrays | |
885 | * may already have been created because they were needed to | |
886 | * enable allocations for slab creation. | |
887 | */ | |
d50112ed | 888 | void __init create_kmalloc_caches(slab_flags_t flags) |
34cc6990 | 889 | { |
13657d0a PL |
890 | int i; |
891 | enum kmalloc_cache_type type; | |
34cc6990 | 892 | |
494c1dfe WL |
893 | /* |
894 | * Including KMALLOC_CGROUP if CONFIG_MEMCG_KMEM defined | |
895 | */ | |
33647783 | 896 | for (type = KMALLOC_NORMAL; type < NR_KMALLOC_TYPES; type++) { |
1291523f VB |
897 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { |
898 | if (!kmalloc_caches[type][i]) | |
899 | new_kmalloc_cache(i, type, flags); | |
f97d5f63 | 900 | |
1291523f VB |
901 | /* |
902 | * Caches that are not of the two-to-the-power-of size. | |
903 | * These have to be created immediately after the | |
904 | * earlier power of two caches | |
905 | */ | |
906 | if (KMALLOC_MIN_SIZE <= 32 && i == 6 && | |
907 | !kmalloc_caches[type][1]) | |
908 | new_kmalloc_cache(1, type, flags); | |
909 | if (KMALLOC_MIN_SIZE <= 64 && i == 7 && | |
910 | !kmalloc_caches[type][2]) | |
911 | new_kmalloc_cache(2, type, flags); | |
912 | } | |
8a965b3b CL |
913 | } |
914 | ||
f97d5f63 CL |
915 | /* Kmalloc array is now usable */ |
916 | slab_state = UP; | |
f97d5f63 | 917 | } |
d6a71648 HY |
918 | |
919 | void free_large_kmalloc(struct folio *folio, void *object) | |
920 | { | |
921 | unsigned int order = folio_order(folio); | |
922 | ||
923 | if (WARN_ON_ONCE(order == 0)) | |
924 | pr_warn_once("object pointer: 0x%p\n", object); | |
925 | ||
926 | kmemleak_free(object); | |
927 | kasan_kfree_large(object); | |
27bc50fc | 928 | kmsan_kfree_large(object); |
d6a71648 HY |
929 | |
930 | mod_lruvec_page_state(folio_page(folio, 0), NR_SLAB_UNRECLAIMABLE_B, | |
931 | -(PAGE_SIZE << order)); | |
932 | __free_pages(folio_page(folio, 0), order); | |
933 | } | |
b1405135 HY |
934 | |
935 | static void *__kmalloc_large_node(size_t size, gfp_t flags, int node); | |
936 | static __always_inline | |
937 | void *__do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) | |
938 | { | |
939 | struct kmem_cache *s; | |
940 | void *ret; | |
941 | ||
942 | if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) { | |
943 | ret = __kmalloc_large_node(size, flags, node); | |
2c1d697f | 944 | trace_kmalloc(_RET_IP_, ret, size, |
11e9734b | 945 | PAGE_SIZE << get_order(size), flags, node); |
b1405135 HY |
946 | return ret; |
947 | } | |
948 | ||
949 | s = kmalloc_slab(size, flags); | |
950 | ||
951 | if (unlikely(ZERO_OR_NULL_PTR(s))) | |
952 | return s; | |
953 | ||
954 | ret = __kmem_cache_alloc_node(s, flags, node, size, caller); | |
955 | ret = kasan_kmalloc(s, ret, size, flags); | |
2c1d697f | 956 | trace_kmalloc(_RET_IP_, ret, size, s->size, flags, node); |
b1405135 HY |
957 | return ret; |
958 | } | |
959 | ||
960 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
961 | { | |
962 | return __do_kmalloc_node(size, flags, node, _RET_IP_); | |
963 | } | |
964 | EXPORT_SYMBOL(__kmalloc_node); | |
965 | ||
966 | void *__kmalloc(size_t size, gfp_t flags) | |
967 | { | |
968 | return __do_kmalloc_node(size, flags, NUMA_NO_NODE, _RET_IP_); | |
969 | } | |
970 | EXPORT_SYMBOL(__kmalloc); | |
971 | ||
972 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, | |
973 | int node, unsigned long caller) | |
974 | { | |
975 | return __do_kmalloc_node(size, flags, node, caller); | |
976 | } | |
977 | EXPORT_SYMBOL(__kmalloc_node_track_caller); | |
978 | ||
979 | /** | |
980 | * kfree - free previously allocated memory | |
981 | * @object: pointer returned by kmalloc. | |
982 | * | |
983 | * If @object is NULL, no operation is performed. | |
984 | * | |
985 | * Don't free memory not originally allocated by kmalloc() | |
986 | * or you will run into trouble. | |
987 | */ | |
988 | void kfree(const void *object) | |
989 | { | |
990 | struct folio *folio; | |
991 | struct slab *slab; | |
992 | struct kmem_cache *s; | |
993 | ||
994 | trace_kfree(_RET_IP_, object); | |
995 | ||
996 | if (unlikely(ZERO_OR_NULL_PTR(object))) | |
997 | return; | |
998 | ||
999 | folio = virt_to_folio(object); | |
1000 | if (unlikely(!folio_test_slab(folio))) { | |
1001 | free_large_kmalloc(folio, (void *)object); | |
1002 | return; | |
1003 | } | |
1004 | ||
1005 | slab = folio_slab(folio); | |
1006 | s = slab->slab_cache; | |
1007 | __kmem_cache_free(s, (void *)object, _RET_IP_); | |
1008 | } | |
1009 | EXPORT_SYMBOL(kfree); | |
1010 | ||
445d41d7 VB |
1011 | /** |
1012 | * __ksize -- Report full size of underlying allocation | |
1013 | * @objp: pointer to the object | |
1014 | * | |
1015 | * This should only be used internally to query the true size of allocations. | |
1016 | * It is not meant to be a way to discover the usable size of an allocation | |
1017 | * after the fact. Instead, use kmalloc_size_roundup(). Using memory beyond | |
1018 | * the originally requested allocation size may trigger KASAN, UBSAN_BOUNDS, | |
1019 | * and/or FORTIFY_SOURCE. | |
1020 | * | |
1021 | * Return: size of the actual memory used by @objp in bytes | |
1022 | */ | |
b1405135 HY |
1023 | size_t __ksize(const void *object) |
1024 | { | |
1025 | struct folio *folio; | |
1026 | ||
1027 | if (unlikely(object == ZERO_SIZE_PTR)) | |
1028 | return 0; | |
1029 | ||
1030 | folio = virt_to_folio(object); | |
1031 | ||
d5eff736 HY |
1032 | if (unlikely(!folio_test_slab(folio))) { |
1033 | if (WARN_ON(folio_size(folio) <= KMALLOC_MAX_CACHE_SIZE)) | |
1034 | return 0; | |
1035 | if (WARN_ON(object != folio_address(folio))) | |
1036 | return 0; | |
b1405135 | 1037 | return folio_size(folio); |
d5eff736 | 1038 | } |
b1405135 HY |
1039 | |
1040 | return slab_ksize(folio_slab(folio)->slab_cache); | |
1041 | } | |
26a40990 HY |
1042 | |
1043 | #ifdef CONFIG_TRACING | |
1044 | void *kmalloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size) | |
1045 | { | |
1046 | void *ret = __kmem_cache_alloc_node(s, gfpflags, NUMA_NO_NODE, | |
1047 | size, _RET_IP_); | |
1048 | ||
2c1d697f | 1049 | trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, NUMA_NO_NODE); |
26a40990 HY |
1050 | |
1051 | ret = kasan_kmalloc(s, ret, size, gfpflags); | |
1052 | return ret; | |
1053 | } | |
1054 | EXPORT_SYMBOL(kmalloc_trace); | |
1055 | ||
1056 | void *kmalloc_node_trace(struct kmem_cache *s, gfp_t gfpflags, | |
1057 | int node, size_t size) | |
1058 | { | |
1059 | void *ret = __kmem_cache_alloc_node(s, gfpflags, node, size, _RET_IP_); | |
1060 | ||
2c1d697f | 1061 | trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags, node); |
26a40990 HY |
1062 | |
1063 | ret = kasan_kmalloc(s, ret, size, gfpflags); | |
1064 | return ret; | |
1065 | } | |
1066 | EXPORT_SYMBOL(kmalloc_node_trace); | |
1067 | #endif /* !CONFIG_TRACING */ | |
45530c44 CL |
1068 | #endif /* !CONFIG_SLOB */ |
1069 | ||
44405099 LL |
1070 | gfp_t kmalloc_fix_flags(gfp_t flags) |
1071 | { | |
1072 | gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; | |
1073 | ||
1074 | flags &= ~GFP_SLAB_BUG_MASK; | |
1075 | pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", | |
1076 | invalid_mask, &invalid_mask, flags, &flags); | |
1077 | dump_stack(); | |
1078 | ||
1079 | return flags; | |
1080 | } | |
1081 | ||
cea371f4 VD |
1082 | /* |
1083 | * To avoid unnecessary overhead, we pass through large allocation requests | |
1084 | * directly to the page allocator. We use __GFP_COMP, because we will need to | |
1085 | * know the allocation order to free the pages properly in kfree. | |
1086 | */ | |
45530c44 | 1087 | |
b1405135 | 1088 | static void *__kmalloc_large_node(size_t size, gfp_t flags, int node) |
52383431 | 1089 | { |
52383431 | 1090 | struct page *page; |
a0c3b940 HY |
1091 | void *ptr = NULL; |
1092 | unsigned int order = get_order(size); | |
52383431 | 1093 | |
44405099 LL |
1094 | if (unlikely(flags & GFP_SLAB_BUG_MASK)) |
1095 | flags = kmalloc_fix_flags(flags); | |
1096 | ||
52383431 | 1097 | flags |= __GFP_COMP; |
a0c3b940 HY |
1098 | page = alloc_pages_node(node, flags, order); |
1099 | if (page) { | |
1100 | ptr = page_address(page); | |
96403bfe MS |
1101 | mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B, |
1102 | PAGE_SIZE << order); | |
6a486c0a | 1103 | } |
a0c3b940 HY |
1104 | |
1105 | ptr = kasan_kmalloc_large(ptr, size, flags); | |
1106 | /* As ptr might get tagged, call kmemleak hook after KASAN. */ | |
1107 | kmemleak_alloc(ptr, size, 1, flags); | |
27bc50fc | 1108 | kmsan_kmalloc_large(ptr, size, flags); |
a0c3b940 HY |
1109 | |
1110 | return ptr; | |
1111 | } | |
bf37d791 | 1112 | |
c4cab557 HY |
1113 | void *kmalloc_large(size_t size, gfp_t flags) |
1114 | { | |
b1405135 | 1115 | void *ret = __kmalloc_large_node(size, flags, NUMA_NO_NODE); |
c4cab557 | 1116 | |
2c1d697f HY |
1117 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size), |
1118 | flags, NUMA_NO_NODE); | |
52383431 VD |
1119 | return ret; |
1120 | } | |
c4cab557 | 1121 | EXPORT_SYMBOL(kmalloc_large); |
52383431 | 1122 | |
bf37d791 | 1123 | void *kmalloc_large_node(size_t size, gfp_t flags, int node) |
f1b6eb6e | 1124 | { |
b1405135 | 1125 | void *ret = __kmalloc_large_node(size, flags, node); |
bf37d791 | 1126 | |
2c1d697f HY |
1127 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size), |
1128 | flags, node); | |
f1b6eb6e CL |
1129 | return ret; |
1130 | } | |
a0c3b940 | 1131 | EXPORT_SYMBOL(kmalloc_large_node); |
45530c44 | 1132 | |
7c00fce9 TG |
1133 | #ifdef CONFIG_SLAB_FREELIST_RANDOM |
1134 | /* Randomize a generic freelist */ | |
1135 | static void freelist_randomize(struct rnd_state *state, unsigned int *list, | |
302d55d5 | 1136 | unsigned int count) |
7c00fce9 | 1137 | { |
7c00fce9 | 1138 | unsigned int rand; |
302d55d5 | 1139 | unsigned int i; |
7c00fce9 TG |
1140 | |
1141 | for (i = 0; i < count; i++) | |
1142 | list[i] = i; | |
1143 | ||
1144 | /* Fisher-Yates shuffle */ | |
1145 | for (i = count - 1; i > 0; i--) { | |
1146 | rand = prandom_u32_state(state); | |
1147 | rand %= (i + 1); | |
1148 | swap(list[i], list[rand]); | |
1149 | } | |
1150 | } | |
1151 | ||
1152 | /* Create a random sequence per cache */ | |
1153 | int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, | |
1154 | gfp_t gfp) | |
1155 | { | |
1156 | struct rnd_state state; | |
1157 | ||
1158 | if (count < 2 || cachep->random_seq) | |
1159 | return 0; | |
1160 | ||
1161 | cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp); | |
1162 | if (!cachep->random_seq) | |
1163 | return -ENOMEM; | |
1164 | ||
1165 | /* Get best entropy at this stage of boot */ | |
1166 | prandom_seed_state(&state, get_random_long()); | |
1167 | ||
1168 | freelist_randomize(&state, cachep->random_seq, count); | |
1169 | return 0; | |
1170 | } | |
1171 | ||
1172 | /* Destroy the per-cache random freelist sequence */ | |
1173 | void cache_random_seq_destroy(struct kmem_cache *cachep) | |
1174 | { | |
1175 | kfree(cachep->random_seq); | |
1176 | cachep->random_seq = NULL; | |
1177 | } | |
1178 | #endif /* CONFIG_SLAB_FREELIST_RANDOM */ | |
1179 | ||
5b365771 | 1180 | #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) |
e9b4db2b | 1181 | #ifdef CONFIG_SLAB |
0825a6f9 | 1182 | #define SLABINFO_RIGHTS (0600) |
e9b4db2b | 1183 | #else |
0825a6f9 | 1184 | #define SLABINFO_RIGHTS (0400) |
e9b4db2b WL |
1185 | #endif |
1186 | ||
b047501c | 1187 | static void print_slabinfo_header(struct seq_file *m) |
bcee6e2a GC |
1188 | { |
1189 | /* | |
1190 | * Output format version, so at least we can change it | |
1191 | * without _too_ many complaints. | |
1192 | */ | |
1193 | #ifdef CONFIG_DEBUG_SLAB | |
1194 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
1195 | #else | |
1196 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
1197 | #endif | |
756a025f | 1198 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); |
bcee6e2a GC |
1199 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
1200 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
1201 | #ifdef CONFIG_DEBUG_SLAB | |
756a025f | 1202 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); |
bcee6e2a GC |
1203 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); |
1204 | #endif | |
1205 | seq_putc(m, '\n'); | |
1206 | } | |
1207 | ||
c29b5b3d | 1208 | static void *slab_start(struct seq_file *m, loff_t *pos) |
b7454ad3 | 1209 | { |
b7454ad3 | 1210 | mutex_lock(&slab_mutex); |
c7094406 | 1211 | return seq_list_start(&slab_caches, *pos); |
b7454ad3 GC |
1212 | } |
1213 | ||
c29b5b3d | 1214 | static void *slab_next(struct seq_file *m, void *p, loff_t *pos) |
b7454ad3 | 1215 | { |
c7094406 | 1216 | return seq_list_next(p, &slab_caches, pos); |
b7454ad3 GC |
1217 | } |
1218 | ||
c29b5b3d | 1219 | static void slab_stop(struct seq_file *m, void *p) |
b7454ad3 GC |
1220 | { |
1221 | mutex_unlock(&slab_mutex); | |
1222 | } | |
1223 | ||
b047501c | 1224 | static void cache_show(struct kmem_cache *s, struct seq_file *m) |
b7454ad3 | 1225 | { |
0d7561c6 GC |
1226 | struct slabinfo sinfo; |
1227 | ||
1228 | memset(&sinfo, 0, sizeof(sinfo)); | |
1229 | get_slabinfo(s, &sinfo); | |
1230 | ||
1231 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", | |
10befea9 | 1232 | s->name, sinfo.active_objs, sinfo.num_objs, s->size, |
0d7561c6 GC |
1233 | sinfo.objects_per_slab, (1 << sinfo.cache_order)); |
1234 | ||
1235 | seq_printf(m, " : tunables %4u %4u %4u", | |
1236 | sinfo.limit, sinfo.batchcount, sinfo.shared); | |
1237 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
1238 | sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); | |
1239 | slabinfo_show_stats(m, s); | |
1240 | seq_putc(m, '\n'); | |
b7454ad3 GC |
1241 | } |
1242 | ||
1df3b26f | 1243 | static int slab_show(struct seq_file *m, void *p) |
749c5415 | 1244 | { |
c7094406 | 1245 | struct kmem_cache *s = list_entry(p, struct kmem_cache, list); |
749c5415 | 1246 | |
c7094406 | 1247 | if (p == slab_caches.next) |
1df3b26f | 1248 | print_slabinfo_header(m); |
10befea9 | 1249 | cache_show(s, m); |
b047501c VD |
1250 | return 0; |
1251 | } | |
1252 | ||
852d8be0 YS |
1253 | void dump_unreclaimable_slab(void) |
1254 | { | |
7714304f | 1255 | struct kmem_cache *s; |
852d8be0 YS |
1256 | struct slabinfo sinfo; |
1257 | ||
1258 | /* | |
1259 | * Here acquiring slab_mutex is risky since we don't prefer to get | |
1260 | * sleep in oom path. But, without mutex hold, it may introduce a | |
1261 | * risk of crash. | |
1262 | * Use mutex_trylock to protect the list traverse, dump nothing | |
1263 | * without acquiring the mutex. | |
1264 | */ | |
1265 | if (!mutex_trylock(&slab_mutex)) { | |
1266 | pr_warn("excessive unreclaimable slab but cannot dump stats\n"); | |
1267 | return; | |
1268 | } | |
1269 | ||
1270 | pr_info("Unreclaimable slab info:\n"); | |
1271 | pr_info("Name Used Total\n"); | |
1272 | ||
7714304f | 1273 | list_for_each_entry(s, &slab_caches, list) { |
10befea9 | 1274 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
852d8be0 YS |
1275 | continue; |
1276 | ||
1277 | get_slabinfo(s, &sinfo); | |
1278 | ||
1279 | if (sinfo.num_objs > 0) | |
10befea9 | 1280 | pr_info("%-17s %10luKB %10luKB\n", s->name, |
852d8be0 YS |
1281 | (sinfo.active_objs * s->size) / 1024, |
1282 | (sinfo.num_objs * s->size) / 1024); | |
1283 | } | |
1284 | mutex_unlock(&slab_mutex); | |
1285 | } | |
1286 | ||
b7454ad3 GC |
1287 | /* |
1288 | * slabinfo_op - iterator that generates /proc/slabinfo | |
1289 | * | |
1290 | * Output layout: | |
1291 | * cache-name | |
1292 | * num-active-objs | |
1293 | * total-objs | |
1294 | * object size | |
1295 | * num-active-slabs | |
1296 | * total-slabs | |
1297 | * num-pages-per-slab | |
1298 | * + further values on SMP and with statistics enabled | |
1299 | */ | |
1300 | static const struct seq_operations slabinfo_op = { | |
1df3b26f | 1301 | .start = slab_start, |
276a2439 WL |
1302 | .next = slab_next, |
1303 | .stop = slab_stop, | |
1df3b26f | 1304 | .show = slab_show, |
b7454ad3 GC |
1305 | }; |
1306 | ||
1307 | static int slabinfo_open(struct inode *inode, struct file *file) | |
1308 | { | |
1309 | return seq_open(file, &slabinfo_op); | |
1310 | } | |
1311 | ||
97a32539 | 1312 | static const struct proc_ops slabinfo_proc_ops = { |
d919b33d | 1313 | .proc_flags = PROC_ENTRY_PERMANENT, |
97a32539 AD |
1314 | .proc_open = slabinfo_open, |
1315 | .proc_read = seq_read, | |
1316 | .proc_write = slabinfo_write, | |
1317 | .proc_lseek = seq_lseek, | |
1318 | .proc_release = seq_release, | |
b7454ad3 GC |
1319 | }; |
1320 | ||
1321 | static int __init slab_proc_init(void) | |
1322 | { | |
97a32539 | 1323 | proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops); |
b7454ad3 GC |
1324 | return 0; |
1325 | } | |
1326 | module_init(slab_proc_init); | |
fcf8a1e4 | 1327 | |
5b365771 | 1328 | #endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */ |
928cec9c | 1329 | |
9ed9cac1 KC |
1330 | static __always_inline __realloc_size(2) void * |
1331 | __do_krealloc(const void *p, size_t new_size, gfp_t flags) | |
928cec9c AR |
1332 | { |
1333 | void *ret; | |
fa9ba3aa | 1334 | size_t ks; |
928cec9c | 1335 | |
d12d9ad8 AK |
1336 | /* Don't use instrumented ksize to allow precise KASAN poisoning. */ |
1337 | if (likely(!ZERO_OR_NULL_PTR(p))) { | |
1338 | if (!kasan_check_byte(p)) | |
1339 | return NULL; | |
1340 | ks = kfence_ksize(p) ?: __ksize(p); | |
1341 | } else | |
1342 | ks = 0; | |
928cec9c | 1343 | |
d12d9ad8 | 1344 | /* If the object still fits, repoison it precisely. */ |
0316bec2 | 1345 | if (ks >= new_size) { |
0116523c | 1346 | p = kasan_krealloc((void *)p, new_size, flags); |
928cec9c | 1347 | return (void *)p; |
0316bec2 | 1348 | } |
928cec9c AR |
1349 | |
1350 | ret = kmalloc_track_caller(new_size, flags); | |
d12d9ad8 AK |
1351 | if (ret && p) { |
1352 | /* Disable KASAN checks as the object's redzone is accessed. */ | |
1353 | kasan_disable_current(); | |
1354 | memcpy(ret, kasan_reset_tag(p), ks); | |
1355 | kasan_enable_current(); | |
1356 | } | |
928cec9c AR |
1357 | |
1358 | return ret; | |
1359 | } | |
1360 | ||
928cec9c AR |
1361 | /** |
1362 | * krealloc - reallocate memory. The contents will remain unchanged. | |
1363 | * @p: object to reallocate memory for. | |
1364 | * @new_size: how many bytes of memory are required. | |
1365 | * @flags: the type of memory to allocate. | |
1366 | * | |
1367 | * The contents of the object pointed to are preserved up to the | |
15d5de49 BG |
1368 | * lesser of the new and old sizes (__GFP_ZERO flag is effectively ignored). |
1369 | * If @p is %NULL, krealloc() behaves exactly like kmalloc(). If @new_size | |
1370 | * is 0 and @p is not a %NULL pointer, the object pointed to is freed. | |
a862f68a MR |
1371 | * |
1372 | * Return: pointer to the allocated memory or %NULL in case of error | |
928cec9c AR |
1373 | */ |
1374 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
1375 | { | |
1376 | void *ret; | |
1377 | ||
1378 | if (unlikely(!new_size)) { | |
1379 | kfree(p); | |
1380 | return ZERO_SIZE_PTR; | |
1381 | } | |
1382 | ||
1383 | ret = __do_krealloc(p, new_size, flags); | |
772a2fa5 | 1384 | if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret)) |
928cec9c AR |
1385 | kfree(p); |
1386 | ||
1387 | return ret; | |
1388 | } | |
1389 | EXPORT_SYMBOL(krealloc); | |
1390 | ||
1391 | /** | |
453431a5 | 1392 | * kfree_sensitive - Clear sensitive information in memory before freeing |
928cec9c AR |
1393 | * @p: object to free memory of |
1394 | * | |
1395 | * The memory of the object @p points to is zeroed before freed. | |
453431a5 | 1396 | * If @p is %NULL, kfree_sensitive() does nothing. |
928cec9c AR |
1397 | * |
1398 | * Note: this function zeroes the whole allocated buffer which can be a good | |
1399 | * deal bigger than the requested buffer size passed to kmalloc(). So be | |
1400 | * careful when using this function in performance sensitive code. | |
1401 | */ | |
453431a5 | 1402 | void kfree_sensitive(const void *p) |
928cec9c AR |
1403 | { |
1404 | size_t ks; | |
1405 | void *mem = (void *)p; | |
1406 | ||
928cec9c | 1407 | ks = ksize(mem); |
fa9ba3aa WK |
1408 | if (ks) |
1409 | memzero_explicit(mem, ks); | |
928cec9c AR |
1410 | kfree(mem); |
1411 | } | |
453431a5 | 1412 | EXPORT_SYMBOL(kfree_sensitive); |
928cec9c | 1413 | |
10d1f8cb ME |
1414 | /** |
1415 | * ksize - get the actual amount of memory allocated for a given object | |
1416 | * @objp: Pointer to the object | |
1417 | * | |
1418 | * kmalloc may internally round up allocations and return more memory | |
1419 | * than requested. ksize() can be used to determine the actual amount of | |
1420 | * memory allocated. The caller may use this additional memory, even though | |
1421 | * a smaller amount of memory was initially specified with the kmalloc call. | |
1422 | * The caller must guarantee that objp points to a valid object previously | |
1423 | * allocated with either kmalloc() or kmem_cache_alloc(). The object | |
1424 | * must not be freed during the duration of the call. | |
1425 | * | |
1426 | * Return: size of the actual memory used by @objp in bytes | |
1427 | */ | |
1428 | size_t ksize(const void *objp) | |
1429 | { | |
0d4ca4c9 ME |
1430 | size_t size; |
1431 | ||
0d4ca4c9 | 1432 | /* |
611806b4 AK |
1433 | * We need to first check that the pointer to the object is valid, and |
1434 | * only then unpoison the memory. The report printed from ksize() is | |
1435 | * more useful, then when it's printed later when the behaviour could | |
1436 | * be undefined due to a potential use-after-free or double-free. | |
0d4ca4c9 | 1437 | * |
611806b4 AK |
1438 | * We use kasan_check_byte(), which is supported for the hardware |
1439 | * tag-based KASAN mode, unlike kasan_check_read/write(). | |
1440 | * | |
1441 | * If the pointed to memory is invalid, we return 0 to avoid users of | |
0d4ca4c9 ME |
1442 | * ksize() writing to and potentially corrupting the memory region. |
1443 | * | |
1444 | * We want to perform the check before __ksize(), to avoid potentially | |
1445 | * crashing in __ksize() due to accessing invalid metadata. | |
1446 | */ | |
611806b4 | 1447 | if (unlikely(ZERO_OR_NULL_PTR(objp)) || !kasan_check_byte(objp)) |
0d4ca4c9 ME |
1448 | return 0; |
1449 | ||
d3fb45f3 | 1450 | size = kfence_ksize(objp) ?: __ksize(objp); |
10d1f8cb ME |
1451 | /* |
1452 | * We assume that ksize callers could use whole allocated area, | |
1453 | * so we need to unpoison this area. | |
1454 | */ | |
cebd0eb2 | 1455 | kasan_unpoison_range(objp, size); |
10d1f8cb ME |
1456 | return size; |
1457 | } | |
1458 | EXPORT_SYMBOL(ksize); | |
1459 | ||
928cec9c AR |
1460 | /* Tracepoints definitions. */ |
1461 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); | |
1462 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); | |
928cec9c AR |
1463 | EXPORT_TRACEPOINT_SYMBOL(kfree); |
1464 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); | |
4f6923fb HM |
1465 | |
1466 | int should_failslab(struct kmem_cache *s, gfp_t gfpflags) | |
1467 | { | |
1468 | if (__should_failslab(s, gfpflags)) | |
1469 | return -ENOMEM; | |
1470 | return 0; | |
1471 | } | |
1472 | ALLOW_ERROR_INJECTION(should_failslab, ERRNO); |