Commit | Line | Data |
---|---|---|
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 CL |
14 | #include <linux/compiler.h> |
15 | #include <linux/module.h> | |
20cea968 CL |
16 | #include <linux/cpu.h> |
17 | #include <linux/uaccess.h> | |
b7454ad3 GC |
18 | #include <linux/seq_file.h> |
19 | #include <linux/proc_fs.h> | |
039363f3 CL |
20 | #include <asm/cacheflush.h> |
21 | #include <asm/tlbflush.h> | |
22 | #include <asm/page.h> | |
2633d7a0 | 23 | #include <linux/memcontrol.h> |
928cec9c AR |
24 | |
25 | #define CREATE_TRACE_POINTS | |
f1b6eb6e | 26 | #include <trace/events/kmem.h> |
039363f3 | 27 | |
97d06609 CL |
28 | #include "slab.h" |
29 | ||
30 | enum slab_state slab_state; | |
18004c5d CL |
31 | LIST_HEAD(slab_caches); |
32 | DEFINE_MUTEX(slab_mutex); | |
9b030cb8 | 33 | struct kmem_cache *kmem_cache; |
97d06609 | 34 | |
2d891fbc KC |
35 | #ifdef CONFIG_HARDENED_USERCOPY |
36 | bool usercopy_fallback __ro_after_init = | |
37 | IS_ENABLED(CONFIG_HARDENED_USERCOPY_FALLBACK); | |
38 | module_param(usercopy_fallback, bool, 0400); | |
39 | MODULE_PARM_DESC(usercopy_fallback, | |
40 | "WARN instead of reject usercopy whitelist violations"); | |
41 | #endif | |
42 | ||
657dc2f9 TH |
43 | static LIST_HEAD(slab_caches_to_rcu_destroy); |
44 | static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work); | |
45 | static DECLARE_WORK(slab_caches_to_rcu_destroy_work, | |
46 | slab_caches_to_rcu_destroy_workfn); | |
47 | ||
423c929c JK |
48 | /* |
49 | * Set of flags that will prevent slab merging | |
50 | */ | |
51 | #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
5f0d5a3a | 52 | SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ |
7ed2f9e6 | 53 | SLAB_FAILSLAB | SLAB_KASAN) |
423c929c | 54 | |
230e9fc2 | 55 | #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ |
75f296d9 | 56 | SLAB_ACCOUNT) |
423c929c JK |
57 | |
58 | /* | |
59 | * Merge control. If this is set then no merging of slab caches will occur. | |
423c929c | 60 | */ |
7660a6fd | 61 | static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT); |
423c929c JK |
62 | |
63 | static int __init setup_slab_nomerge(char *str) | |
64 | { | |
7660a6fd | 65 | slab_nomerge = true; |
423c929c JK |
66 | return 1; |
67 | } | |
68 | ||
69 | #ifdef CONFIG_SLUB | |
70 | __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0); | |
71 | #endif | |
72 | ||
73 | __setup("slab_nomerge", setup_slab_nomerge); | |
74 | ||
07f361b2 JK |
75 | /* |
76 | * Determine the size of a slab object | |
77 | */ | |
78 | unsigned int kmem_cache_size(struct kmem_cache *s) | |
79 | { | |
80 | return s->object_size; | |
81 | } | |
82 | EXPORT_SYMBOL(kmem_cache_size); | |
83 | ||
77be4b13 | 84 | #ifdef CONFIG_DEBUG_VM |
f4957d5b | 85 | static int kmem_cache_sanity_check(const char *name, unsigned int size) |
039363f3 | 86 | { |
039363f3 CL |
87 | if (!name || in_interrupt() || size < sizeof(void *) || |
88 | size > KMALLOC_MAX_SIZE) { | |
77be4b13 SK |
89 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); |
90 | return -EINVAL; | |
039363f3 | 91 | } |
b920536a | 92 | |
20cea968 | 93 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ |
77be4b13 SK |
94 | return 0; |
95 | } | |
96 | #else | |
f4957d5b | 97 | static inline int kmem_cache_sanity_check(const char *name, unsigned int size) |
77be4b13 SK |
98 | { |
99 | return 0; | |
100 | } | |
20cea968 CL |
101 | #endif |
102 | ||
484748f0 CL |
103 | void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p) |
104 | { | |
105 | size_t i; | |
106 | ||
ca257195 JDB |
107 | for (i = 0; i < nr; i++) { |
108 | if (s) | |
109 | kmem_cache_free(s, p[i]); | |
110 | else | |
111 | kfree(p[i]); | |
112 | } | |
484748f0 CL |
113 | } |
114 | ||
865762a8 | 115 | int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr, |
484748f0 CL |
116 | void **p) |
117 | { | |
118 | size_t i; | |
119 | ||
120 | for (i = 0; i < nr; i++) { | |
121 | void *x = p[i] = kmem_cache_alloc(s, flags); | |
122 | if (!x) { | |
123 | __kmem_cache_free_bulk(s, i, p); | |
865762a8 | 124 | return 0; |
484748f0 CL |
125 | } |
126 | } | |
865762a8 | 127 | return i; |
484748f0 CL |
128 | } |
129 | ||
127424c8 | 130 | #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) |
510ded33 TH |
131 | |
132 | LIST_HEAD(slab_root_caches); | |
133 | ||
f7ce3190 | 134 | void slab_init_memcg_params(struct kmem_cache *s) |
33a690c4 | 135 | { |
9eeadc8b | 136 | s->memcg_params.root_cache = NULL; |
f7ce3190 | 137 | RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL); |
9eeadc8b | 138 | INIT_LIST_HEAD(&s->memcg_params.children); |
f7ce3190 VD |
139 | } |
140 | ||
141 | static int init_memcg_params(struct kmem_cache *s, | |
142 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
143 | { | |
144 | struct memcg_cache_array *arr; | |
33a690c4 | 145 | |
9eeadc8b | 146 | if (root_cache) { |
f7ce3190 | 147 | s->memcg_params.root_cache = root_cache; |
9eeadc8b TH |
148 | s->memcg_params.memcg = memcg; |
149 | INIT_LIST_HEAD(&s->memcg_params.children_node); | |
bc2791f8 | 150 | INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node); |
33a690c4 | 151 | return 0; |
f7ce3190 | 152 | } |
33a690c4 | 153 | |
f7ce3190 | 154 | slab_init_memcg_params(s); |
33a690c4 | 155 | |
f7ce3190 VD |
156 | if (!memcg_nr_cache_ids) |
157 | return 0; | |
33a690c4 | 158 | |
f80c7dab JW |
159 | arr = kvzalloc(sizeof(struct memcg_cache_array) + |
160 | memcg_nr_cache_ids * sizeof(void *), | |
161 | GFP_KERNEL); | |
f7ce3190 VD |
162 | if (!arr) |
163 | return -ENOMEM; | |
33a690c4 | 164 | |
f7ce3190 | 165 | RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr); |
33a690c4 VD |
166 | return 0; |
167 | } | |
168 | ||
f7ce3190 | 169 | static void destroy_memcg_params(struct kmem_cache *s) |
33a690c4 | 170 | { |
f7ce3190 | 171 | if (is_root_cache(s)) |
f80c7dab JW |
172 | kvfree(rcu_access_pointer(s->memcg_params.memcg_caches)); |
173 | } | |
174 | ||
175 | static void free_memcg_params(struct rcu_head *rcu) | |
176 | { | |
177 | struct memcg_cache_array *old; | |
178 | ||
179 | old = container_of(rcu, struct memcg_cache_array, rcu); | |
180 | kvfree(old); | |
33a690c4 VD |
181 | } |
182 | ||
f7ce3190 | 183 | static int update_memcg_params(struct kmem_cache *s, int new_array_size) |
6f817f4c | 184 | { |
f7ce3190 | 185 | struct memcg_cache_array *old, *new; |
6f817f4c | 186 | |
f80c7dab JW |
187 | new = kvzalloc(sizeof(struct memcg_cache_array) + |
188 | new_array_size * sizeof(void *), GFP_KERNEL); | |
f7ce3190 | 189 | if (!new) |
6f817f4c VD |
190 | return -ENOMEM; |
191 | ||
f7ce3190 VD |
192 | old = rcu_dereference_protected(s->memcg_params.memcg_caches, |
193 | lockdep_is_held(&slab_mutex)); | |
194 | if (old) | |
195 | memcpy(new->entries, old->entries, | |
196 | memcg_nr_cache_ids * sizeof(void *)); | |
6f817f4c | 197 | |
f7ce3190 VD |
198 | rcu_assign_pointer(s->memcg_params.memcg_caches, new); |
199 | if (old) | |
f80c7dab | 200 | call_rcu(&old->rcu, free_memcg_params); |
6f817f4c VD |
201 | return 0; |
202 | } | |
203 | ||
55007d84 GC |
204 | int memcg_update_all_caches(int num_memcgs) |
205 | { | |
206 | struct kmem_cache *s; | |
207 | int ret = 0; | |
55007d84 | 208 | |
05257a1a | 209 | mutex_lock(&slab_mutex); |
510ded33 | 210 | list_for_each_entry(s, &slab_root_caches, root_caches_node) { |
f7ce3190 | 211 | ret = update_memcg_params(s, num_memcgs); |
55007d84 | 212 | /* |
55007d84 GC |
213 | * Instead of freeing the memory, we'll just leave the caches |
214 | * up to this point in an updated state. | |
215 | */ | |
216 | if (ret) | |
05257a1a | 217 | break; |
55007d84 | 218 | } |
55007d84 GC |
219 | mutex_unlock(&slab_mutex); |
220 | return ret; | |
221 | } | |
657dc2f9 | 222 | |
510ded33 | 223 | void memcg_link_cache(struct kmem_cache *s) |
657dc2f9 | 224 | { |
510ded33 TH |
225 | if (is_root_cache(s)) { |
226 | list_add(&s->root_caches_node, &slab_root_caches); | |
227 | } else { | |
228 | list_add(&s->memcg_params.children_node, | |
229 | &s->memcg_params.root_cache->memcg_params.children); | |
230 | list_add(&s->memcg_params.kmem_caches_node, | |
231 | &s->memcg_params.memcg->kmem_caches); | |
232 | } | |
233 | } | |
234 | ||
235 | static void memcg_unlink_cache(struct kmem_cache *s) | |
236 | { | |
237 | if (is_root_cache(s)) { | |
238 | list_del(&s->root_caches_node); | |
239 | } else { | |
240 | list_del(&s->memcg_params.children_node); | |
241 | list_del(&s->memcg_params.kmem_caches_node); | |
242 | } | |
657dc2f9 | 243 | } |
33a690c4 | 244 | #else |
f7ce3190 VD |
245 | static inline int init_memcg_params(struct kmem_cache *s, |
246 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
33a690c4 VD |
247 | { |
248 | return 0; | |
249 | } | |
250 | ||
f7ce3190 | 251 | static inline void destroy_memcg_params(struct kmem_cache *s) |
33a690c4 VD |
252 | { |
253 | } | |
657dc2f9 | 254 | |
510ded33 | 255 | static inline void memcg_unlink_cache(struct kmem_cache *s) |
657dc2f9 TH |
256 | { |
257 | } | |
127424c8 | 258 | #endif /* CONFIG_MEMCG && !CONFIG_SLOB */ |
55007d84 | 259 | |
692ae74a BL |
260 | /* |
261 | * Figure out what the alignment of the objects will be given a set of | |
262 | * flags, a user specified alignment and the size of the objects. | |
263 | */ | |
f4957d5b AD |
264 | static unsigned int calculate_alignment(slab_flags_t flags, |
265 | unsigned int align, unsigned int size) | |
692ae74a BL |
266 | { |
267 | /* | |
268 | * If the user wants hardware cache aligned objects then follow that | |
269 | * suggestion if the object is sufficiently large. | |
270 | * | |
271 | * The hardware cache alignment cannot override the specified | |
272 | * alignment though. If that is greater then use it. | |
273 | */ | |
274 | if (flags & SLAB_HWCACHE_ALIGN) { | |
f4957d5b | 275 | unsigned int ralign; |
692ae74a BL |
276 | |
277 | ralign = cache_line_size(); | |
278 | while (size <= ralign / 2) | |
279 | ralign /= 2; | |
280 | align = max(align, ralign); | |
281 | } | |
282 | ||
283 | if (align < ARCH_SLAB_MINALIGN) | |
284 | align = ARCH_SLAB_MINALIGN; | |
285 | ||
286 | return ALIGN(align, sizeof(void *)); | |
287 | } | |
288 | ||
423c929c JK |
289 | /* |
290 | * Find a mergeable slab cache | |
291 | */ | |
292 | int slab_unmergeable(struct kmem_cache *s) | |
293 | { | |
294 | if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) | |
295 | return 1; | |
296 | ||
297 | if (!is_root_cache(s)) | |
298 | return 1; | |
299 | ||
300 | if (s->ctor) | |
301 | return 1; | |
302 | ||
8eb8284b DW |
303 | if (s->usersize) |
304 | return 1; | |
305 | ||
423c929c JK |
306 | /* |
307 | * We may have set a slab to be unmergeable during bootstrap. | |
308 | */ | |
309 | if (s->refcount < 0) | |
310 | return 1; | |
311 | ||
312 | return 0; | |
313 | } | |
314 | ||
f4957d5b | 315 | struct kmem_cache *find_mergeable(unsigned int size, unsigned int align, |
d50112ed | 316 | slab_flags_t flags, const char *name, void (*ctor)(void *)) |
423c929c JK |
317 | { |
318 | struct kmem_cache *s; | |
319 | ||
c6e28895 | 320 | if (slab_nomerge) |
423c929c JK |
321 | return NULL; |
322 | ||
323 | if (ctor) | |
324 | return NULL; | |
325 | ||
326 | size = ALIGN(size, sizeof(void *)); | |
327 | align = calculate_alignment(flags, align, size); | |
328 | size = ALIGN(size, align); | |
329 | flags = kmem_cache_flags(size, flags, name, NULL); | |
330 | ||
c6e28895 GM |
331 | if (flags & SLAB_NEVER_MERGE) |
332 | return NULL; | |
333 | ||
510ded33 | 334 | list_for_each_entry_reverse(s, &slab_root_caches, root_caches_node) { |
423c929c JK |
335 | if (slab_unmergeable(s)) |
336 | continue; | |
337 | ||
338 | if (size > s->size) | |
339 | continue; | |
340 | ||
341 | if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) | |
342 | continue; | |
343 | /* | |
344 | * Check if alignment is compatible. | |
345 | * Courtesy of Adrian Drzewiecki | |
346 | */ | |
347 | if ((s->size & ~(align - 1)) != s->size) | |
348 | continue; | |
349 | ||
350 | if (s->size - size >= sizeof(void *)) | |
351 | continue; | |
352 | ||
95069ac8 JK |
353 | if (IS_ENABLED(CONFIG_SLAB) && align && |
354 | (align > s->align || s->align % align)) | |
355 | continue; | |
356 | ||
423c929c JK |
357 | return s; |
358 | } | |
359 | return NULL; | |
360 | } | |
361 | ||
c9a77a79 | 362 | static struct kmem_cache *create_cache(const char *name, |
613a5eb5 | 363 | unsigned int object_size, unsigned int align, |
7bbdb81e AD |
364 | slab_flags_t flags, unsigned int useroffset, |
365 | unsigned int usersize, void (*ctor)(void *), | |
c9a77a79 | 366 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) |
794b1248 VD |
367 | { |
368 | struct kmem_cache *s; | |
369 | int err; | |
370 | ||
8eb8284b DW |
371 | if (WARN_ON(useroffset + usersize > object_size)) |
372 | useroffset = usersize = 0; | |
373 | ||
794b1248 VD |
374 | err = -ENOMEM; |
375 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); | |
376 | if (!s) | |
377 | goto out; | |
378 | ||
379 | s->name = name; | |
613a5eb5 | 380 | s->size = s->object_size = object_size; |
794b1248 VD |
381 | s->align = align; |
382 | s->ctor = ctor; | |
8eb8284b DW |
383 | s->useroffset = useroffset; |
384 | s->usersize = usersize; | |
794b1248 | 385 | |
f7ce3190 | 386 | err = init_memcg_params(s, memcg, root_cache); |
794b1248 VD |
387 | if (err) |
388 | goto out_free_cache; | |
389 | ||
390 | err = __kmem_cache_create(s, flags); | |
391 | if (err) | |
392 | goto out_free_cache; | |
393 | ||
394 | s->refcount = 1; | |
395 | list_add(&s->list, &slab_caches); | |
510ded33 | 396 | memcg_link_cache(s); |
794b1248 VD |
397 | out: |
398 | if (err) | |
399 | return ERR_PTR(err); | |
400 | return s; | |
401 | ||
402 | out_free_cache: | |
f7ce3190 | 403 | destroy_memcg_params(s); |
7c4da061 | 404 | kmem_cache_free(kmem_cache, s); |
794b1248 VD |
405 | goto out; |
406 | } | |
45906855 | 407 | |
77be4b13 | 408 | /* |
8eb8284b | 409 | * kmem_cache_create_usercopy - Create a cache. |
77be4b13 SK |
410 | * @name: A string which is used in /proc/slabinfo to identify this cache. |
411 | * @size: The size of objects to be created in this cache. | |
412 | * @align: The required alignment for the objects. | |
413 | * @flags: SLAB flags | |
8eb8284b DW |
414 | * @useroffset: Usercopy region offset |
415 | * @usersize: Usercopy region size | |
77be4b13 SK |
416 | * @ctor: A constructor for the objects. |
417 | * | |
418 | * Returns a ptr to the cache on success, NULL on failure. | |
419 | * Cannot be called within a interrupt, but can be interrupted. | |
420 | * The @ctor is run when new pages are allocated by the cache. | |
421 | * | |
422 | * The flags are | |
423 | * | |
424 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
425 | * to catch references to uninitialised memory. | |
426 | * | |
427 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
428 | * for buffer overruns. | |
429 | * | |
430 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
431 | * cacheline. This can be beneficial if you're counting cycles as closely | |
432 | * as davem. | |
433 | */ | |
2633d7a0 | 434 | struct kmem_cache * |
f4957d5b AD |
435 | kmem_cache_create_usercopy(const char *name, |
436 | unsigned int size, unsigned int align, | |
7bbdb81e AD |
437 | slab_flags_t flags, |
438 | unsigned int useroffset, unsigned int usersize, | |
8eb8284b | 439 | void (*ctor)(void *)) |
77be4b13 | 440 | { |
40911a79 | 441 | struct kmem_cache *s = NULL; |
3dec16ea | 442 | const char *cache_name; |
3965fc36 | 443 | int err; |
039363f3 | 444 | |
77be4b13 | 445 | get_online_cpus(); |
03afc0e2 | 446 | get_online_mems(); |
05257a1a | 447 | memcg_get_cache_ids(); |
03afc0e2 | 448 | |
77be4b13 | 449 | mutex_lock(&slab_mutex); |
686d550d | 450 | |
794b1248 | 451 | err = kmem_cache_sanity_check(name, size); |
3aa24f51 | 452 | if (err) { |
3965fc36 | 453 | goto out_unlock; |
3aa24f51 | 454 | } |
686d550d | 455 | |
e70954fd TG |
456 | /* Refuse requests with allocator specific flags */ |
457 | if (flags & ~SLAB_FLAGS_PERMITTED) { | |
458 | err = -EINVAL; | |
459 | goto out_unlock; | |
460 | } | |
461 | ||
d8843922 GC |
462 | /* |
463 | * Some allocators will constraint the set of valid flags to a subset | |
464 | * of all flags. We expect them to define CACHE_CREATE_MASK in this | |
465 | * case, and we'll just provide them with a sanitized version of the | |
466 | * passed flags. | |
467 | */ | |
468 | flags &= CACHE_CREATE_MASK; | |
686d550d | 469 | |
8eb8284b DW |
470 | /* Fail closed on bad usersize of useroffset values. */ |
471 | if (WARN_ON(!usersize && useroffset) || | |
472 | WARN_ON(size < usersize || size - usersize < useroffset)) | |
473 | usersize = useroffset = 0; | |
474 | ||
475 | if (!usersize) | |
476 | s = __kmem_cache_alias(name, size, align, flags, ctor); | |
794b1248 | 477 | if (s) |
3965fc36 | 478 | goto out_unlock; |
2633d7a0 | 479 | |
3dec16ea | 480 | cache_name = kstrdup_const(name, GFP_KERNEL); |
794b1248 VD |
481 | if (!cache_name) { |
482 | err = -ENOMEM; | |
483 | goto out_unlock; | |
484 | } | |
7c9adf5a | 485 | |
613a5eb5 | 486 | s = create_cache(cache_name, size, |
c9a77a79 | 487 | calculate_alignment(flags, align, size), |
8eb8284b | 488 | flags, useroffset, usersize, ctor, NULL, NULL); |
794b1248 VD |
489 | if (IS_ERR(s)) { |
490 | err = PTR_ERR(s); | |
3dec16ea | 491 | kfree_const(cache_name); |
794b1248 | 492 | } |
3965fc36 VD |
493 | |
494 | out_unlock: | |
20cea968 | 495 | mutex_unlock(&slab_mutex); |
03afc0e2 | 496 | |
05257a1a | 497 | memcg_put_cache_ids(); |
03afc0e2 | 498 | put_online_mems(); |
20cea968 CL |
499 | put_online_cpus(); |
500 | ||
ba3253c7 | 501 | if (err) { |
686d550d CL |
502 | if (flags & SLAB_PANIC) |
503 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
504 | name, err); | |
505 | else { | |
1170532b | 506 | pr_warn("kmem_cache_create(%s) failed with error %d\n", |
686d550d CL |
507 | name, err); |
508 | dump_stack(); | |
509 | } | |
686d550d CL |
510 | return NULL; |
511 | } | |
039363f3 CL |
512 | return s; |
513 | } | |
8eb8284b DW |
514 | EXPORT_SYMBOL(kmem_cache_create_usercopy); |
515 | ||
516 | struct kmem_cache * | |
f4957d5b | 517 | kmem_cache_create(const char *name, unsigned int size, unsigned int align, |
8eb8284b DW |
518 | slab_flags_t flags, void (*ctor)(void *)) |
519 | { | |
6d07d1cd | 520 | return kmem_cache_create_usercopy(name, size, align, flags, 0, 0, |
8eb8284b DW |
521 | ctor); |
522 | } | |
794b1248 | 523 | EXPORT_SYMBOL(kmem_cache_create); |
2633d7a0 | 524 | |
657dc2f9 | 525 | static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work) |
d5b3cf71 | 526 | { |
657dc2f9 TH |
527 | LIST_HEAD(to_destroy); |
528 | struct kmem_cache *s, *s2; | |
d5b3cf71 | 529 | |
657dc2f9 | 530 | /* |
5f0d5a3a | 531 | * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the |
657dc2f9 TH |
532 | * @slab_caches_to_rcu_destroy list. The slab pages are freed |
533 | * through RCU and and the associated kmem_cache are dereferenced | |
534 | * while freeing the pages, so the kmem_caches should be freed only | |
535 | * after the pending RCU operations are finished. As rcu_barrier() | |
536 | * is a pretty slow operation, we batch all pending destructions | |
537 | * asynchronously. | |
538 | */ | |
539 | mutex_lock(&slab_mutex); | |
540 | list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy); | |
541 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 542 | |
657dc2f9 TH |
543 | if (list_empty(&to_destroy)) |
544 | return; | |
545 | ||
546 | rcu_barrier(); | |
547 | ||
548 | list_for_each_entry_safe(s, s2, &to_destroy, list) { | |
549 | #ifdef SLAB_SUPPORTS_SYSFS | |
550 | sysfs_slab_release(s); | |
551 | #else | |
552 | slab_kmem_cache_release(s); | |
553 | #endif | |
554 | } | |
d5b3cf71 VD |
555 | } |
556 | ||
657dc2f9 | 557 | static int shutdown_cache(struct kmem_cache *s) |
d5b3cf71 | 558 | { |
f9fa1d91 GT |
559 | /* free asan quarantined objects */ |
560 | kasan_cache_shutdown(s); | |
561 | ||
657dc2f9 TH |
562 | if (__kmem_cache_shutdown(s) != 0) |
563 | return -EBUSY; | |
d5b3cf71 | 564 | |
510ded33 | 565 | memcg_unlink_cache(s); |
657dc2f9 | 566 | list_del(&s->list); |
d5b3cf71 | 567 | |
5f0d5a3a | 568 | if (s->flags & SLAB_TYPESAFE_BY_RCU) { |
657dc2f9 TH |
569 | list_add_tail(&s->list, &slab_caches_to_rcu_destroy); |
570 | schedule_work(&slab_caches_to_rcu_destroy_work); | |
571 | } else { | |
d5b3cf71 | 572 | #ifdef SLAB_SUPPORTS_SYSFS |
bf5eb3de | 573 | sysfs_slab_release(s); |
d5b3cf71 VD |
574 | #else |
575 | slab_kmem_cache_release(s); | |
576 | #endif | |
577 | } | |
657dc2f9 TH |
578 | |
579 | return 0; | |
d5b3cf71 VD |
580 | } |
581 | ||
127424c8 | 582 | #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) |
794b1248 | 583 | /* |
776ed0f0 | 584 | * memcg_create_kmem_cache - Create a cache for a memory cgroup. |
794b1248 VD |
585 | * @memcg: The memory cgroup the new cache is for. |
586 | * @root_cache: The parent of the new cache. | |
587 | * | |
588 | * This function attempts to create a kmem cache that will serve allocation | |
589 | * requests going from @memcg to @root_cache. The new cache inherits properties | |
590 | * from its parent. | |
591 | */ | |
d5b3cf71 VD |
592 | void memcg_create_kmem_cache(struct mem_cgroup *memcg, |
593 | struct kmem_cache *root_cache) | |
2633d7a0 | 594 | { |
3e0350a3 | 595 | static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */ |
33398cf2 | 596 | struct cgroup_subsys_state *css = &memcg->css; |
f7ce3190 | 597 | struct memcg_cache_array *arr; |
bd673145 | 598 | struct kmem_cache *s = NULL; |
794b1248 | 599 | char *cache_name; |
f7ce3190 | 600 | int idx; |
794b1248 VD |
601 | |
602 | get_online_cpus(); | |
03afc0e2 VD |
603 | get_online_mems(); |
604 | ||
794b1248 VD |
605 | mutex_lock(&slab_mutex); |
606 | ||
2a4db7eb | 607 | /* |
567e9ab2 | 608 | * The memory cgroup could have been offlined while the cache |
2a4db7eb VD |
609 | * creation work was pending. |
610 | */ | |
b6ecd2de | 611 | if (memcg->kmem_state != KMEM_ONLINE) |
2a4db7eb VD |
612 | goto out_unlock; |
613 | ||
f7ce3190 VD |
614 | idx = memcg_cache_id(memcg); |
615 | arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches, | |
616 | lockdep_is_held(&slab_mutex)); | |
617 | ||
d5b3cf71 VD |
618 | /* |
619 | * Since per-memcg caches are created asynchronously on first | |
620 | * allocation (see memcg_kmem_get_cache()), several threads can try to | |
621 | * create the same cache, but only one of them may succeed. | |
622 | */ | |
f7ce3190 | 623 | if (arr->entries[idx]) |
d5b3cf71 VD |
624 | goto out_unlock; |
625 | ||
f1008365 | 626 | cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf)); |
73f576c0 JW |
627 | cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name, |
628 | css->serial_nr, memcg_name_buf); | |
794b1248 VD |
629 | if (!cache_name) |
630 | goto out_unlock; | |
631 | ||
c9a77a79 | 632 | s = create_cache(cache_name, root_cache->object_size, |
613a5eb5 | 633 | root_cache->align, |
f773e36d | 634 | root_cache->flags & CACHE_CREATE_MASK, |
8eb8284b | 635 | root_cache->useroffset, root_cache->usersize, |
f773e36d | 636 | root_cache->ctor, memcg, root_cache); |
d5b3cf71 VD |
637 | /* |
638 | * If we could not create a memcg cache, do not complain, because | |
639 | * that's not critical at all as we can always proceed with the root | |
640 | * cache. | |
641 | */ | |
bd673145 | 642 | if (IS_ERR(s)) { |
794b1248 | 643 | kfree(cache_name); |
d5b3cf71 | 644 | goto out_unlock; |
bd673145 | 645 | } |
794b1248 | 646 | |
d5b3cf71 VD |
647 | /* |
648 | * Since readers won't lock (see cache_from_memcg_idx()), we need a | |
649 | * barrier here to ensure nobody will see the kmem_cache partially | |
650 | * initialized. | |
651 | */ | |
652 | smp_wmb(); | |
f7ce3190 | 653 | arr->entries[idx] = s; |
d5b3cf71 | 654 | |
794b1248 VD |
655 | out_unlock: |
656 | mutex_unlock(&slab_mutex); | |
03afc0e2 VD |
657 | |
658 | put_online_mems(); | |
794b1248 | 659 | put_online_cpus(); |
2633d7a0 | 660 | } |
b8529907 | 661 | |
01fb58bc TH |
662 | static void kmemcg_deactivate_workfn(struct work_struct *work) |
663 | { | |
664 | struct kmem_cache *s = container_of(work, struct kmem_cache, | |
665 | memcg_params.deact_work); | |
666 | ||
667 | get_online_cpus(); | |
668 | get_online_mems(); | |
669 | ||
670 | mutex_lock(&slab_mutex); | |
671 | ||
672 | s->memcg_params.deact_fn(s); | |
673 | ||
674 | mutex_unlock(&slab_mutex); | |
675 | ||
676 | put_online_mems(); | |
677 | put_online_cpus(); | |
678 | ||
679 | /* done, put the ref from slab_deactivate_memcg_cache_rcu_sched() */ | |
680 | css_put(&s->memcg_params.memcg->css); | |
681 | } | |
682 | ||
683 | static void kmemcg_deactivate_rcufn(struct rcu_head *head) | |
684 | { | |
685 | struct kmem_cache *s = container_of(head, struct kmem_cache, | |
686 | memcg_params.deact_rcu_head); | |
687 | ||
688 | /* | |
689 | * We need to grab blocking locks. Bounce to ->deact_work. The | |
690 | * work item shares the space with the RCU head and can't be | |
691 | * initialized eariler. | |
692 | */ | |
693 | INIT_WORK(&s->memcg_params.deact_work, kmemcg_deactivate_workfn); | |
17cc4dfe | 694 | queue_work(memcg_kmem_cache_wq, &s->memcg_params.deact_work); |
01fb58bc TH |
695 | } |
696 | ||
697 | /** | |
698 | * slab_deactivate_memcg_cache_rcu_sched - schedule deactivation after a | |
699 | * sched RCU grace period | |
700 | * @s: target kmem_cache | |
701 | * @deact_fn: deactivation function to call | |
702 | * | |
703 | * Schedule @deact_fn to be invoked with online cpus, mems and slab_mutex | |
704 | * held after a sched RCU grace period. The slab is guaranteed to stay | |
705 | * alive until @deact_fn is finished. This is to be used from | |
706 | * __kmemcg_cache_deactivate(). | |
707 | */ | |
708 | void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, | |
709 | void (*deact_fn)(struct kmem_cache *)) | |
710 | { | |
711 | if (WARN_ON_ONCE(is_root_cache(s)) || | |
712 | WARN_ON_ONCE(s->memcg_params.deact_fn)) | |
713 | return; | |
714 | ||
715 | /* pin memcg so that @s doesn't get destroyed in the middle */ | |
716 | css_get(&s->memcg_params.memcg->css); | |
717 | ||
718 | s->memcg_params.deact_fn = deact_fn; | |
719 | call_rcu_sched(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn); | |
720 | } | |
721 | ||
2a4db7eb VD |
722 | void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) |
723 | { | |
724 | int idx; | |
725 | struct memcg_cache_array *arr; | |
d6e0b7fa | 726 | struct kmem_cache *s, *c; |
2a4db7eb VD |
727 | |
728 | idx = memcg_cache_id(memcg); | |
729 | ||
d6e0b7fa VD |
730 | get_online_cpus(); |
731 | get_online_mems(); | |
732 | ||
2a4db7eb | 733 | mutex_lock(&slab_mutex); |
510ded33 | 734 | list_for_each_entry(s, &slab_root_caches, root_caches_node) { |
2a4db7eb VD |
735 | arr = rcu_dereference_protected(s->memcg_params.memcg_caches, |
736 | lockdep_is_held(&slab_mutex)); | |
d6e0b7fa VD |
737 | c = arr->entries[idx]; |
738 | if (!c) | |
739 | continue; | |
740 | ||
c9fc5864 | 741 | __kmemcg_cache_deactivate(c); |
2a4db7eb VD |
742 | arr->entries[idx] = NULL; |
743 | } | |
744 | mutex_unlock(&slab_mutex); | |
d6e0b7fa VD |
745 | |
746 | put_online_mems(); | |
747 | put_online_cpus(); | |
2a4db7eb VD |
748 | } |
749 | ||
d5b3cf71 | 750 | void memcg_destroy_kmem_caches(struct mem_cgroup *memcg) |
b8529907 | 751 | { |
d5b3cf71 | 752 | struct kmem_cache *s, *s2; |
b8529907 | 753 | |
d5b3cf71 VD |
754 | get_online_cpus(); |
755 | get_online_mems(); | |
b8529907 | 756 | |
b8529907 | 757 | mutex_lock(&slab_mutex); |
bc2791f8 TH |
758 | list_for_each_entry_safe(s, s2, &memcg->kmem_caches, |
759 | memcg_params.kmem_caches_node) { | |
d5b3cf71 VD |
760 | /* |
761 | * The cgroup is about to be freed and therefore has no charges | |
762 | * left. Hence, all its caches must be empty by now. | |
763 | */ | |
657dc2f9 | 764 | BUG_ON(shutdown_cache(s)); |
d5b3cf71 VD |
765 | } |
766 | mutex_unlock(&slab_mutex); | |
b8529907 | 767 | |
d5b3cf71 VD |
768 | put_online_mems(); |
769 | put_online_cpus(); | |
b8529907 | 770 | } |
d60fdcc9 | 771 | |
657dc2f9 | 772 | static int shutdown_memcg_caches(struct kmem_cache *s) |
d60fdcc9 VD |
773 | { |
774 | struct memcg_cache_array *arr; | |
775 | struct kmem_cache *c, *c2; | |
776 | LIST_HEAD(busy); | |
777 | int i; | |
778 | ||
779 | BUG_ON(!is_root_cache(s)); | |
780 | ||
781 | /* | |
782 | * First, shutdown active caches, i.e. caches that belong to online | |
783 | * memory cgroups. | |
784 | */ | |
785 | arr = rcu_dereference_protected(s->memcg_params.memcg_caches, | |
786 | lockdep_is_held(&slab_mutex)); | |
787 | for_each_memcg_cache_index(i) { | |
788 | c = arr->entries[i]; | |
789 | if (!c) | |
790 | continue; | |
657dc2f9 | 791 | if (shutdown_cache(c)) |
d60fdcc9 VD |
792 | /* |
793 | * The cache still has objects. Move it to a temporary | |
794 | * list so as not to try to destroy it for a second | |
795 | * time while iterating over inactive caches below. | |
796 | */ | |
9eeadc8b | 797 | list_move(&c->memcg_params.children_node, &busy); |
d60fdcc9 VD |
798 | else |
799 | /* | |
800 | * The cache is empty and will be destroyed soon. Clear | |
801 | * the pointer to it in the memcg_caches array so that | |
802 | * it will never be accessed even if the root cache | |
803 | * stays alive. | |
804 | */ | |
805 | arr->entries[i] = NULL; | |
806 | } | |
807 | ||
808 | /* | |
809 | * Second, shutdown all caches left from memory cgroups that are now | |
810 | * offline. | |
811 | */ | |
9eeadc8b TH |
812 | list_for_each_entry_safe(c, c2, &s->memcg_params.children, |
813 | memcg_params.children_node) | |
657dc2f9 | 814 | shutdown_cache(c); |
d60fdcc9 | 815 | |
9eeadc8b | 816 | list_splice(&busy, &s->memcg_params.children); |
d60fdcc9 VD |
817 | |
818 | /* | |
819 | * A cache being destroyed must be empty. In particular, this means | |
820 | * that all per memcg caches attached to it must be empty too. | |
821 | */ | |
9eeadc8b | 822 | if (!list_empty(&s->memcg_params.children)) |
d60fdcc9 VD |
823 | return -EBUSY; |
824 | return 0; | |
825 | } | |
826 | #else | |
657dc2f9 | 827 | static inline int shutdown_memcg_caches(struct kmem_cache *s) |
d60fdcc9 VD |
828 | { |
829 | return 0; | |
830 | } | |
127424c8 | 831 | #endif /* CONFIG_MEMCG && !CONFIG_SLOB */ |
97d06609 | 832 | |
41a21285 CL |
833 | void slab_kmem_cache_release(struct kmem_cache *s) |
834 | { | |
52b4b950 | 835 | __kmem_cache_release(s); |
f7ce3190 | 836 | destroy_memcg_params(s); |
3dec16ea | 837 | kfree_const(s->name); |
41a21285 CL |
838 | kmem_cache_free(kmem_cache, s); |
839 | } | |
840 | ||
945cf2b6 CL |
841 | void kmem_cache_destroy(struct kmem_cache *s) |
842 | { | |
d60fdcc9 | 843 | int err; |
d5b3cf71 | 844 | |
3942d299 SS |
845 | if (unlikely(!s)) |
846 | return; | |
847 | ||
945cf2b6 | 848 | get_online_cpus(); |
03afc0e2 VD |
849 | get_online_mems(); |
850 | ||
945cf2b6 | 851 | mutex_lock(&slab_mutex); |
b8529907 | 852 | |
945cf2b6 | 853 | s->refcount--; |
b8529907 VD |
854 | if (s->refcount) |
855 | goto out_unlock; | |
856 | ||
657dc2f9 | 857 | err = shutdown_memcg_caches(s); |
d60fdcc9 | 858 | if (!err) |
657dc2f9 | 859 | err = shutdown_cache(s); |
b8529907 | 860 | |
cd918c55 | 861 | if (err) { |
756a025f JP |
862 | pr_err("kmem_cache_destroy %s: Slab cache still has objects\n", |
863 | s->name); | |
cd918c55 VD |
864 | dump_stack(); |
865 | } | |
b8529907 VD |
866 | out_unlock: |
867 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 868 | |
03afc0e2 | 869 | put_online_mems(); |
945cf2b6 CL |
870 | put_online_cpus(); |
871 | } | |
872 | EXPORT_SYMBOL(kmem_cache_destroy); | |
873 | ||
03afc0e2 VD |
874 | /** |
875 | * kmem_cache_shrink - Shrink a cache. | |
876 | * @cachep: The cache to shrink. | |
877 | * | |
878 | * Releases as many slabs as possible for a cache. | |
879 | * To help debugging, a zero exit status indicates all slabs were released. | |
880 | */ | |
881 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
882 | { | |
883 | int ret; | |
884 | ||
885 | get_online_cpus(); | |
886 | get_online_mems(); | |
55834c59 | 887 | kasan_cache_shrink(cachep); |
c9fc5864 | 888 | ret = __kmem_cache_shrink(cachep); |
03afc0e2 VD |
889 | put_online_mems(); |
890 | put_online_cpus(); | |
891 | return ret; | |
892 | } | |
893 | EXPORT_SYMBOL(kmem_cache_shrink); | |
894 | ||
fda90124 | 895 | bool slab_is_available(void) |
97d06609 CL |
896 | { |
897 | return slab_state >= UP; | |
898 | } | |
b7454ad3 | 899 | |
45530c44 CL |
900 | #ifndef CONFIG_SLOB |
901 | /* Create a cache during boot when no slab services are available yet */ | |
361d575e AD |
902 | void __init create_boot_cache(struct kmem_cache *s, const char *name, |
903 | unsigned int size, slab_flags_t flags, | |
904 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
905 | { |
906 | int err; | |
907 | ||
908 | s->name = name; | |
909 | s->size = s->object_size = size; | |
45906855 | 910 | s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size); |
8eb8284b DW |
911 | s->useroffset = useroffset; |
912 | s->usersize = usersize; | |
f7ce3190 VD |
913 | |
914 | slab_init_memcg_params(s); | |
915 | ||
45530c44 CL |
916 | err = __kmem_cache_create(s, flags); |
917 | ||
918 | if (err) | |
361d575e | 919 | panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n", |
45530c44 CL |
920 | name, size, err); |
921 | ||
922 | s->refcount = -1; /* Exempt from merging for now */ | |
923 | } | |
924 | ||
55de8b9c AD |
925 | struct kmem_cache *__init create_kmalloc_cache(const char *name, |
926 | unsigned int size, slab_flags_t flags, | |
927 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
928 | { |
929 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); | |
930 | ||
931 | if (!s) | |
932 | panic("Out of memory when creating slab %s\n", name); | |
933 | ||
6c0c21ad | 934 | create_boot_cache(s, name, size, flags, useroffset, usersize); |
45530c44 | 935 | list_add(&s->list, &slab_caches); |
510ded33 | 936 | memcg_link_cache(s); |
45530c44 CL |
937 | s->refcount = 1; |
938 | return s; | |
939 | } | |
940 | ||
1c99ba29 | 941 | struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1] __ro_after_init; |
9425c58e CL |
942 | EXPORT_SYMBOL(kmalloc_caches); |
943 | ||
944 | #ifdef CONFIG_ZONE_DMA | |
1c99ba29 | 945 | struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1] __ro_after_init; |
9425c58e CL |
946 | EXPORT_SYMBOL(kmalloc_dma_caches); |
947 | #endif | |
948 | ||
2c59dd65 CL |
949 | /* |
950 | * Conversion table for small slabs sizes / 8 to the index in the | |
951 | * kmalloc array. This is necessary for slabs < 192 since we have non power | |
952 | * of two cache sizes there. The size of larger slabs can be determined using | |
953 | * fls. | |
954 | */ | |
d5f86655 | 955 | static u8 size_index[24] __ro_after_init = { |
2c59dd65 CL |
956 | 3, /* 8 */ |
957 | 4, /* 16 */ | |
958 | 5, /* 24 */ | |
959 | 5, /* 32 */ | |
960 | 6, /* 40 */ | |
961 | 6, /* 48 */ | |
962 | 6, /* 56 */ | |
963 | 6, /* 64 */ | |
964 | 1, /* 72 */ | |
965 | 1, /* 80 */ | |
966 | 1, /* 88 */ | |
967 | 1, /* 96 */ | |
968 | 7, /* 104 */ | |
969 | 7, /* 112 */ | |
970 | 7, /* 120 */ | |
971 | 7, /* 128 */ | |
972 | 2, /* 136 */ | |
973 | 2, /* 144 */ | |
974 | 2, /* 152 */ | |
975 | 2, /* 160 */ | |
976 | 2, /* 168 */ | |
977 | 2, /* 176 */ | |
978 | 2, /* 184 */ | |
979 | 2 /* 192 */ | |
980 | }; | |
981 | ||
ac914d08 | 982 | static inline unsigned int size_index_elem(unsigned int bytes) |
2c59dd65 CL |
983 | { |
984 | return (bytes - 1) / 8; | |
985 | } | |
986 | ||
987 | /* | |
988 | * Find the kmem_cache structure that serves a given size of | |
989 | * allocation | |
990 | */ | |
991 | struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) | |
992 | { | |
d5f86655 | 993 | unsigned int index; |
2c59dd65 | 994 | |
9de1bc87 | 995 | if (unlikely(size > KMALLOC_MAX_SIZE)) { |
907985f4 | 996 | WARN_ON_ONCE(!(flags & __GFP_NOWARN)); |
6286ae97 | 997 | return NULL; |
907985f4 | 998 | } |
6286ae97 | 999 | |
2c59dd65 CL |
1000 | if (size <= 192) { |
1001 | if (!size) | |
1002 | return ZERO_SIZE_PTR; | |
1003 | ||
1004 | index = size_index[size_index_elem(size)]; | |
1005 | } else | |
1006 | index = fls(size - 1); | |
1007 | ||
1008 | #ifdef CONFIG_ZONE_DMA | |
b1e05416 | 1009 | if (unlikely((flags & GFP_DMA))) |
2c59dd65 CL |
1010 | return kmalloc_dma_caches[index]; |
1011 | ||
1012 | #endif | |
1013 | return kmalloc_caches[index]; | |
1014 | } | |
1015 | ||
4066c33d GG |
1016 | /* |
1017 | * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time. | |
1018 | * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is | |
1019 | * kmalloc-67108864. | |
1020 | */ | |
af3b5f87 | 1021 | const struct kmalloc_info_struct kmalloc_info[] __initconst = { |
4066c33d GG |
1022 | {NULL, 0}, {"kmalloc-96", 96}, |
1023 | {"kmalloc-192", 192}, {"kmalloc-8", 8}, | |
1024 | {"kmalloc-16", 16}, {"kmalloc-32", 32}, | |
1025 | {"kmalloc-64", 64}, {"kmalloc-128", 128}, | |
1026 | {"kmalloc-256", 256}, {"kmalloc-512", 512}, | |
1027 | {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048}, | |
1028 | {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192}, | |
1029 | {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768}, | |
1030 | {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072}, | |
1031 | {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288}, | |
1032 | {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152}, | |
1033 | {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608}, | |
1034 | {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432}, | |
1035 | {"kmalloc-67108864", 67108864} | |
1036 | }; | |
1037 | ||
f97d5f63 | 1038 | /* |
34cc6990 DS |
1039 | * Patch up the size_index table if we have strange large alignment |
1040 | * requirements for the kmalloc array. This is only the case for | |
1041 | * MIPS it seems. The standard arches will not generate any code here. | |
1042 | * | |
1043 | * Largest permitted alignment is 256 bytes due to the way we | |
1044 | * handle the index determination for the smaller caches. | |
1045 | * | |
1046 | * Make sure that nothing crazy happens if someone starts tinkering | |
1047 | * around with ARCH_KMALLOC_MINALIGN | |
f97d5f63 | 1048 | */ |
34cc6990 | 1049 | void __init setup_kmalloc_cache_index_table(void) |
f97d5f63 | 1050 | { |
ac914d08 | 1051 | unsigned int i; |
f97d5f63 | 1052 | |
2c59dd65 CL |
1053 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || |
1054 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); | |
1055 | ||
1056 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { | |
ac914d08 | 1057 | unsigned int elem = size_index_elem(i); |
2c59dd65 CL |
1058 | |
1059 | if (elem >= ARRAY_SIZE(size_index)) | |
1060 | break; | |
1061 | size_index[elem] = KMALLOC_SHIFT_LOW; | |
1062 | } | |
1063 | ||
1064 | if (KMALLOC_MIN_SIZE >= 64) { | |
1065 | /* | |
1066 | * The 96 byte size cache is not used if the alignment | |
1067 | * is 64 byte. | |
1068 | */ | |
1069 | for (i = 64 + 8; i <= 96; i += 8) | |
1070 | size_index[size_index_elem(i)] = 7; | |
1071 | ||
1072 | } | |
1073 | ||
1074 | if (KMALLOC_MIN_SIZE >= 128) { | |
1075 | /* | |
1076 | * The 192 byte sized cache is not used if the alignment | |
1077 | * is 128 byte. Redirect kmalloc to use the 256 byte cache | |
1078 | * instead. | |
1079 | */ | |
1080 | for (i = 128 + 8; i <= 192; i += 8) | |
1081 | size_index[size_index_elem(i)] = 8; | |
1082 | } | |
34cc6990 DS |
1083 | } |
1084 | ||
d50112ed | 1085 | static void __init new_kmalloc_cache(int idx, slab_flags_t flags) |
a9730fca CL |
1086 | { |
1087 | kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name, | |
6c0c21ad DW |
1088 | kmalloc_info[idx].size, flags, 0, |
1089 | kmalloc_info[idx].size); | |
a9730fca CL |
1090 | } |
1091 | ||
34cc6990 DS |
1092 | /* |
1093 | * Create the kmalloc array. Some of the regular kmalloc arrays | |
1094 | * may already have been created because they were needed to | |
1095 | * enable allocations for slab creation. | |
1096 | */ | |
d50112ed | 1097 | void __init create_kmalloc_caches(slab_flags_t flags) |
34cc6990 DS |
1098 | { |
1099 | int i; | |
1100 | ||
a9730fca CL |
1101 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { |
1102 | if (!kmalloc_caches[i]) | |
1103 | new_kmalloc_cache(i, flags); | |
f97d5f63 | 1104 | |
956e46ef | 1105 | /* |
a9730fca CL |
1106 | * Caches that are not of the two-to-the-power-of size. |
1107 | * These have to be created immediately after the | |
1108 | * earlier power of two caches | |
956e46ef | 1109 | */ |
a9730fca CL |
1110 | if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6) |
1111 | new_kmalloc_cache(1, flags); | |
1112 | if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7) | |
1113 | new_kmalloc_cache(2, flags); | |
8a965b3b CL |
1114 | } |
1115 | ||
f97d5f63 CL |
1116 | /* Kmalloc array is now usable */ |
1117 | slab_state = UP; | |
1118 | ||
f97d5f63 CL |
1119 | #ifdef CONFIG_ZONE_DMA |
1120 | for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { | |
1121 | struct kmem_cache *s = kmalloc_caches[i]; | |
1122 | ||
1123 | if (s) { | |
0be70327 | 1124 | unsigned int size = kmalloc_size(i); |
f97d5f63 | 1125 | char *n = kasprintf(GFP_NOWAIT, |
0be70327 | 1126 | "dma-kmalloc-%u", size); |
f97d5f63 CL |
1127 | |
1128 | BUG_ON(!n); | |
1129 | kmalloc_dma_caches[i] = create_kmalloc_cache(n, | |
6c0c21ad | 1130 | size, SLAB_CACHE_DMA | flags, 0, 0); |
f97d5f63 CL |
1131 | } |
1132 | } | |
1133 | #endif | |
1134 | } | |
45530c44 CL |
1135 | #endif /* !CONFIG_SLOB */ |
1136 | ||
cea371f4 VD |
1137 | /* |
1138 | * To avoid unnecessary overhead, we pass through large allocation requests | |
1139 | * directly to the page allocator. We use __GFP_COMP, because we will need to | |
1140 | * know the allocation order to free the pages properly in kfree. | |
1141 | */ | |
52383431 VD |
1142 | void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) |
1143 | { | |
1144 | void *ret; | |
1145 | struct page *page; | |
1146 | ||
1147 | flags |= __GFP_COMP; | |
4949148a | 1148 | page = alloc_pages(flags, order); |
52383431 VD |
1149 | ret = page ? page_address(page) : NULL; |
1150 | kmemleak_alloc(ret, size, 1, flags); | |
505f5dcb | 1151 | kasan_kmalloc_large(ret, size, flags); |
52383431 VD |
1152 | return ret; |
1153 | } | |
1154 | EXPORT_SYMBOL(kmalloc_order); | |
1155 | ||
f1b6eb6e CL |
1156 | #ifdef CONFIG_TRACING |
1157 | void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) | |
1158 | { | |
1159 | void *ret = kmalloc_order(size, flags, order); | |
1160 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags); | |
1161 | return ret; | |
1162 | } | |
1163 | EXPORT_SYMBOL(kmalloc_order_trace); | |
1164 | #endif | |
45530c44 | 1165 | |
7c00fce9 TG |
1166 | #ifdef CONFIG_SLAB_FREELIST_RANDOM |
1167 | /* Randomize a generic freelist */ | |
1168 | static void freelist_randomize(struct rnd_state *state, unsigned int *list, | |
302d55d5 | 1169 | unsigned int count) |
7c00fce9 | 1170 | { |
7c00fce9 | 1171 | unsigned int rand; |
302d55d5 | 1172 | unsigned int i; |
7c00fce9 TG |
1173 | |
1174 | for (i = 0; i < count; i++) | |
1175 | list[i] = i; | |
1176 | ||
1177 | /* Fisher-Yates shuffle */ | |
1178 | for (i = count - 1; i > 0; i--) { | |
1179 | rand = prandom_u32_state(state); | |
1180 | rand %= (i + 1); | |
1181 | swap(list[i], list[rand]); | |
1182 | } | |
1183 | } | |
1184 | ||
1185 | /* Create a random sequence per cache */ | |
1186 | int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, | |
1187 | gfp_t gfp) | |
1188 | { | |
1189 | struct rnd_state state; | |
1190 | ||
1191 | if (count < 2 || cachep->random_seq) | |
1192 | return 0; | |
1193 | ||
1194 | cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp); | |
1195 | if (!cachep->random_seq) | |
1196 | return -ENOMEM; | |
1197 | ||
1198 | /* Get best entropy at this stage of boot */ | |
1199 | prandom_seed_state(&state, get_random_long()); | |
1200 | ||
1201 | freelist_randomize(&state, cachep->random_seq, count); | |
1202 | return 0; | |
1203 | } | |
1204 | ||
1205 | /* Destroy the per-cache random freelist sequence */ | |
1206 | void cache_random_seq_destroy(struct kmem_cache *cachep) | |
1207 | { | |
1208 | kfree(cachep->random_seq); | |
1209 | cachep->random_seq = NULL; | |
1210 | } | |
1211 | #endif /* CONFIG_SLAB_FREELIST_RANDOM */ | |
1212 | ||
5b365771 | 1213 | #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) |
e9b4db2b WL |
1214 | #ifdef CONFIG_SLAB |
1215 | #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR) | |
1216 | #else | |
1217 | #define SLABINFO_RIGHTS S_IRUSR | |
1218 | #endif | |
1219 | ||
b047501c | 1220 | static void print_slabinfo_header(struct seq_file *m) |
bcee6e2a GC |
1221 | { |
1222 | /* | |
1223 | * Output format version, so at least we can change it | |
1224 | * without _too_ many complaints. | |
1225 | */ | |
1226 | #ifdef CONFIG_DEBUG_SLAB | |
1227 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
1228 | #else | |
1229 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
1230 | #endif | |
756a025f | 1231 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); |
bcee6e2a GC |
1232 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
1233 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
1234 | #ifdef CONFIG_DEBUG_SLAB | |
756a025f | 1235 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); |
bcee6e2a GC |
1236 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); |
1237 | #endif | |
1238 | seq_putc(m, '\n'); | |
1239 | } | |
1240 | ||
1df3b26f | 1241 | void *slab_start(struct seq_file *m, loff_t *pos) |
b7454ad3 | 1242 | { |
b7454ad3 | 1243 | mutex_lock(&slab_mutex); |
510ded33 | 1244 | return seq_list_start(&slab_root_caches, *pos); |
b7454ad3 GC |
1245 | } |
1246 | ||
276a2439 | 1247 | void *slab_next(struct seq_file *m, void *p, loff_t *pos) |
b7454ad3 | 1248 | { |
510ded33 | 1249 | return seq_list_next(p, &slab_root_caches, pos); |
b7454ad3 GC |
1250 | } |
1251 | ||
276a2439 | 1252 | void slab_stop(struct seq_file *m, void *p) |
b7454ad3 GC |
1253 | { |
1254 | mutex_unlock(&slab_mutex); | |
1255 | } | |
1256 | ||
749c5415 GC |
1257 | static void |
1258 | memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info) | |
1259 | { | |
1260 | struct kmem_cache *c; | |
1261 | struct slabinfo sinfo; | |
749c5415 GC |
1262 | |
1263 | if (!is_root_cache(s)) | |
1264 | return; | |
1265 | ||
426589f5 | 1266 | for_each_memcg_cache(c, s) { |
749c5415 GC |
1267 | memset(&sinfo, 0, sizeof(sinfo)); |
1268 | get_slabinfo(c, &sinfo); | |
1269 | ||
1270 | info->active_slabs += sinfo.active_slabs; | |
1271 | info->num_slabs += sinfo.num_slabs; | |
1272 | info->shared_avail += sinfo.shared_avail; | |
1273 | info->active_objs += sinfo.active_objs; | |
1274 | info->num_objs += sinfo.num_objs; | |
1275 | } | |
1276 | } | |
1277 | ||
b047501c | 1278 | static void cache_show(struct kmem_cache *s, struct seq_file *m) |
b7454ad3 | 1279 | { |
0d7561c6 GC |
1280 | struct slabinfo sinfo; |
1281 | ||
1282 | memset(&sinfo, 0, sizeof(sinfo)); | |
1283 | get_slabinfo(s, &sinfo); | |
1284 | ||
749c5415 GC |
1285 | memcg_accumulate_slabinfo(s, &sinfo); |
1286 | ||
0d7561c6 | 1287 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
749c5415 | 1288 | cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, |
0d7561c6 GC |
1289 | sinfo.objects_per_slab, (1 << sinfo.cache_order)); |
1290 | ||
1291 | seq_printf(m, " : tunables %4u %4u %4u", | |
1292 | sinfo.limit, sinfo.batchcount, sinfo.shared); | |
1293 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
1294 | sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); | |
1295 | slabinfo_show_stats(m, s); | |
1296 | seq_putc(m, '\n'); | |
b7454ad3 GC |
1297 | } |
1298 | ||
1df3b26f | 1299 | static int slab_show(struct seq_file *m, void *p) |
749c5415 | 1300 | { |
510ded33 | 1301 | struct kmem_cache *s = list_entry(p, struct kmem_cache, root_caches_node); |
749c5415 | 1302 | |
510ded33 | 1303 | if (p == slab_root_caches.next) |
1df3b26f | 1304 | print_slabinfo_header(m); |
510ded33 | 1305 | cache_show(s, m); |
b047501c VD |
1306 | return 0; |
1307 | } | |
1308 | ||
852d8be0 YS |
1309 | void dump_unreclaimable_slab(void) |
1310 | { | |
1311 | struct kmem_cache *s, *s2; | |
1312 | struct slabinfo sinfo; | |
1313 | ||
1314 | /* | |
1315 | * Here acquiring slab_mutex is risky since we don't prefer to get | |
1316 | * sleep in oom path. But, without mutex hold, it may introduce a | |
1317 | * risk of crash. | |
1318 | * Use mutex_trylock to protect the list traverse, dump nothing | |
1319 | * without acquiring the mutex. | |
1320 | */ | |
1321 | if (!mutex_trylock(&slab_mutex)) { | |
1322 | pr_warn("excessive unreclaimable slab but cannot dump stats\n"); | |
1323 | return; | |
1324 | } | |
1325 | ||
1326 | pr_info("Unreclaimable slab info:\n"); | |
1327 | pr_info("Name Used Total\n"); | |
1328 | ||
1329 | list_for_each_entry_safe(s, s2, &slab_caches, list) { | |
1330 | if (!is_root_cache(s) || (s->flags & SLAB_RECLAIM_ACCOUNT)) | |
1331 | continue; | |
1332 | ||
1333 | get_slabinfo(s, &sinfo); | |
1334 | ||
1335 | if (sinfo.num_objs > 0) | |
1336 | pr_info("%-17s %10luKB %10luKB\n", cache_name(s), | |
1337 | (sinfo.active_objs * s->size) / 1024, | |
1338 | (sinfo.num_objs * s->size) / 1024); | |
1339 | } | |
1340 | mutex_unlock(&slab_mutex); | |
1341 | } | |
1342 | ||
5b365771 | 1343 | #if defined(CONFIG_MEMCG) |
bc2791f8 TH |
1344 | void *memcg_slab_start(struct seq_file *m, loff_t *pos) |
1345 | { | |
1346 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
1347 | ||
1348 | mutex_lock(&slab_mutex); | |
1349 | return seq_list_start(&memcg->kmem_caches, *pos); | |
1350 | } | |
1351 | ||
1352 | void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos) | |
1353 | { | |
1354 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
1355 | ||
1356 | return seq_list_next(p, &memcg->kmem_caches, pos); | |
1357 | } | |
1358 | ||
1359 | void memcg_slab_stop(struct seq_file *m, void *p) | |
1360 | { | |
1361 | mutex_unlock(&slab_mutex); | |
1362 | } | |
1363 | ||
b047501c VD |
1364 | int memcg_slab_show(struct seq_file *m, void *p) |
1365 | { | |
bc2791f8 TH |
1366 | struct kmem_cache *s = list_entry(p, struct kmem_cache, |
1367 | memcg_params.kmem_caches_node); | |
b047501c VD |
1368 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); |
1369 | ||
bc2791f8 | 1370 | if (p == memcg->kmem_caches.next) |
b047501c | 1371 | print_slabinfo_header(m); |
bc2791f8 | 1372 | cache_show(s, m); |
b047501c | 1373 | return 0; |
749c5415 | 1374 | } |
b047501c | 1375 | #endif |
749c5415 | 1376 | |
b7454ad3 GC |
1377 | /* |
1378 | * slabinfo_op - iterator that generates /proc/slabinfo | |
1379 | * | |
1380 | * Output layout: | |
1381 | * cache-name | |
1382 | * num-active-objs | |
1383 | * total-objs | |
1384 | * object size | |
1385 | * num-active-slabs | |
1386 | * total-slabs | |
1387 | * num-pages-per-slab | |
1388 | * + further values on SMP and with statistics enabled | |
1389 | */ | |
1390 | static const struct seq_operations slabinfo_op = { | |
1df3b26f | 1391 | .start = slab_start, |
276a2439 WL |
1392 | .next = slab_next, |
1393 | .stop = slab_stop, | |
1df3b26f | 1394 | .show = slab_show, |
b7454ad3 GC |
1395 | }; |
1396 | ||
1397 | static int slabinfo_open(struct inode *inode, struct file *file) | |
1398 | { | |
1399 | return seq_open(file, &slabinfo_op); | |
1400 | } | |
1401 | ||
1402 | static const struct file_operations proc_slabinfo_operations = { | |
1403 | .open = slabinfo_open, | |
1404 | .read = seq_read, | |
1405 | .write = slabinfo_write, | |
1406 | .llseek = seq_lseek, | |
1407 | .release = seq_release, | |
1408 | }; | |
1409 | ||
1410 | static int __init slab_proc_init(void) | |
1411 | { | |
e9b4db2b WL |
1412 | proc_create("slabinfo", SLABINFO_RIGHTS, NULL, |
1413 | &proc_slabinfo_operations); | |
b7454ad3 GC |
1414 | return 0; |
1415 | } | |
1416 | module_init(slab_proc_init); | |
5b365771 | 1417 | #endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */ |
928cec9c AR |
1418 | |
1419 | static __always_inline void *__do_krealloc(const void *p, size_t new_size, | |
1420 | gfp_t flags) | |
1421 | { | |
1422 | void *ret; | |
1423 | size_t ks = 0; | |
1424 | ||
1425 | if (p) | |
1426 | ks = ksize(p); | |
1427 | ||
0316bec2 | 1428 | if (ks >= new_size) { |
505f5dcb | 1429 | kasan_krealloc((void *)p, new_size, flags); |
928cec9c | 1430 | return (void *)p; |
0316bec2 | 1431 | } |
928cec9c AR |
1432 | |
1433 | ret = kmalloc_track_caller(new_size, flags); | |
1434 | if (ret && p) | |
1435 | memcpy(ret, p, ks); | |
1436 | ||
1437 | return ret; | |
1438 | } | |
1439 | ||
1440 | /** | |
1441 | * __krealloc - like krealloc() but don't free @p. | |
1442 | * @p: object to reallocate memory for. | |
1443 | * @new_size: how many bytes of memory are required. | |
1444 | * @flags: the type of memory to allocate. | |
1445 | * | |
1446 | * This function is like krealloc() except it never frees the originally | |
1447 | * allocated buffer. Use this if you don't want to free the buffer immediately | |
1448 | * like, for example, with RCU. | |
1449 | */ | |
1450 | void *__krealloc(const void *p, size_t new_size, gfp_t flags) | |
1451 | { | |
1452 | if (unlikely(!new_size)) | |
1453 | return ZERO_SIZE_PTR; | |
1454 | ||
1455 | return __do_krealloc(p, new_size, flags); | |
1456 | ||
1457 | } | |
1458 | EXPORT_SYMBOL(__krealloc); | |
1459 | ||
1460 | /** | |
1461 | * krealloc - reallocate memory. The contents will remain unchanged. | |
1462 | * @p: object to reallocate memory for. | |
1463 | * @new_size: how many bytes of memory are required. | |
1464 | * @flags: the type of memory to allocate. | |
1465 | * | |
1466 | * The contents of the object pointed to are preserved up to the | |
1467 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
1468 | * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a | |
1469 | * %NULL pointer, the object pointed to is freed. | |
1470 | */ | |
1471 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
1472 | { | |
1473 | void *ret; | |
1474 | ||
1475 | if (unlikely(!new_size)) { | |
1476 | kfree(p); | |
1477 | return ZERO_SIZE_PTR; | |
1478 | } | |
1479 | ||
1480 | ret = __do_krealloc(p, new_size, flags); | |
1481 | if (ret && p != ret) | |
1482 | kfree(p); | |
1483 | ||
1484 | return ret; | |
1485 | } | |
1486 | EXPORT_SYMBOL(krealloc); | |
1487 | ||
1488 | /** | |
1489 | * kzfree - like kfree but zero memory | |
1490 | * @p: object to free memory of | |
1491 | * | |
1492 | * The memory of the object @p points to is zeroed before freed. | |
1493 | * If @p is %NULL, kzfree() does nothing. | |
1494 | * | |
1495 | * Note: this function zeroes the whole allocated buffer which can be a good | |
1496 | * deal bigger than the requested buffer size passed to kmalloc(). So be | |
1497 | * careful when using this function in performance sensitive code. | |
1498 | */ | |
1499 | void kzfree(const void *p) | |
1500 | { | |
1501 | size_t ks; | |
1502 | void *mem = (void *)p; | |
1503 | ||
1504 | if (unlikely(ZERO_OR_NULL_PTR(mem))) | |
1505 | return; | |
1506 | ks = ksize(mem); | |
1507 | memset(mem, 0, ks); | |
1508 | kfree(mem); | |
1509 | } | |
1510 | EXPORT_SYMBOL(kzfree); | |
1511 | ||
1512 | /* Tracepoints definitions. */ | |
1513 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); | |
1514 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); | |
1515 | EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); | |
1516 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); | |
1517 | EXPORT_TRACEPOINT_SYMBOL(kfree); | |
1518 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); | |
4f6923fb HM |
1519 | |
1520 | int should_failslab(struct kmem_cache *s, gfp_t gfpflags) | |
1521 | { | |
1522 | if (__should_failslab(s, gfpflags)) | |
1523 | return -ENOMEM; | |
1524 | return 0; | |
1525 | } | |
1526 | ALLOW_ERROR_INJECTION(should_failslab, ERRNO); |