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 | \ |
6d6ea1e9 | 56 | SLAB_CACHE_DMA32 | 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 | ||
84c07d11 | 130 | #ifdef CONFIG_MEMCG_KMEM |
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); |
92ee383f | 139 | s->memcg_params.dying = false; |
f7ce3190 VD |
140 | } |
141 | ||
142 | static int init_memcg_params(struct kmem_cache *s, | |
143 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
144 | { | |
145 | struct memcg_cache_array *arr; | |
33a690c4 | 146 | |
9eeadc8b | 147 | if (root_cache) { |
f7ce3190 | 148 | s->memcg_params.root_cache = root_cache; |
9eeadc8b TH |
149 | s->memcg_params.memcg = memcg; |
150 | INIT_LIST_HEAD(&s->memcg_params.children_node); | |
bc2791f8 | 151 | INIT_LIST_HEAD(&s->memcg_params.kmem_caches_node); |
33a690c4 | 152 | return 0; |
f7ce3190 | 153 | } |
33a690c4 | 154 | |
f7ce3190 | 155 | slab_init_memcg_params(s); |
33a690c4 | 156 | |
f7ce3190 VD |
157 | if (!memcg_nr_cache_ids) |
158 | return 0; | |
33a690c4 | 159 | |
f80c7dab JW |
160 | arr = kvzalloc(sizeof(struct memcg_cache_array) + |
161 | memcg_nr_cache_ids * sizeof(void *), | |
162 | GFP_KERNEL); | |
f7ce3190 VD |
163 | if (!arr) |
164 | return -ENOMEM; | |
33a690c4 | 165 | |
f7ce3190 | 166 | RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr); |
33a690c4 VD |
167 | return 0; |
168 | } | |
169 | ||
f7ce3190 | 170 | static void destroy_memcg_params(struct kmem_cache *s) |
33a690c4 | 171 | { |
f7ce3190 | 172 | if (is_root_cache(s)) |
f80c7dab JW |
173 | kvfree(rcu_access_pointer(s->memcg_params.memcg_caches)); |
174 | } | |
175 | ||
176 | static void free_memcg_params(struct rcu_head *rcu) | |
177 | { | |
178 | struct memcg_cache_array *old; | |
179 | ||
180 | old = container_of(rcu, struct memcg_cache_array, rcu); | |
181 | kvfree(old); | |
33a690c4 VD |
182 | } |
183 | ||
f7ce3190 | 184 | static int update_memcg_params(struct kmem_cache *s, int new_array_size) |
6f817f4c | 185 | { |
f7ce3190 | 186 | struct memcg_cache_array *old, *new; |
6f817f4c | 187 | |
f80c7dab JW |
188 | new = kvzalloc(sizeof(struct memcg_cache_array) + |
189 | new_array_size * sizeof(void *), GFP_KERNEL); | |
f7ce3190 | 190 | if (!new) |
6f817f4c VD |
191 | return -ENOMEM; |
192 | ||
f7ce3190 VD |
193 | old = rcu_dereference_protected(s->memcg_params.memcg_caches, |
194 | lockdep_is_held(&slab_mutex)); | |
195 | if (old) | |
196 | memcpy(new->entries, old->entries, | |
197 | memcg_nr_cache_ids * sizeof(void *)); | |
6f817f4c | 198 | |
f7ce3190 VD |
199 | rcu_assign_pointer(s->memcg_params.memcg_caches, new); |
200 | if (old) | |
f80c7dab | 201 | call_rcu(&old->rcu, free_memcg_params); |
6f817f4c VD |
202 | return 0; |
203 | } | |
204 | ||
55007d84 GC |
205 | int memcg_update_all_caches(int num_memcgs) |
206 | { | |
207 | struct kmem_cache *s; | |
208 | int ret = 0; | |
55007d84 | 209 | |
05257a1a | 210 | mutex_lock(&slab_mutex); |
510ded33 | 211 | list_for_each_entry(s, &slab_root_caches, root_caches_node) { |
f7ce3190 | 212 | ret = update_memcg_params(s, num_memcgs); |
55007d84 | 213 | /* |
55007d84 GC |
214 | * Instead of freeing the memory, we'll just leave the caches |
215 | * up to this point in an updated state. | |
216 | */ | |
217 | if (ret) | |
05257a1a | 218 | break; |
55007d84 | 219 | } |
55007d84 GC |
220 | mutex_unlock(&slab_mutex); |
221 | return ret; | |
222 | } | |
657dc2f9 | 223 | |
510ded33 | 224 | void memcg_link_cache(struct kmem_cache *s) |
657dc2f9 | 225 | { |
510ded33 TH |
226 | if (is_root_cache(s)) { |
227 | list_add(&s->root_caches_node, &slab_root_caches); | |
228 | } else { | |
229 | list_add(&s->memcg_params.children_node, | |
230 | &s->memcg_params.root_cache->memcg_params.children); | |
231 | list_add(&s->memcg_params.kmem_caches_node, | |
232 | &s->memcg_params.memcg->kmem_caches); | |
233 | } | |
234 | } | |
235 | ||
236 | static void memcg_unlink_cache(struct kmem_cache *s) | |
237 | { | |
238 | if (is_root_cache(s)) { | |
239 | list_del(&s->root_caches_node); | |
240 | } else { | |
241 | list_del(&s->memcg_params.children_node); | |
242 | list_del(&s->memcg_params.kmem_caches_node); | |
243 | } | |
657dc2f9 | 244 | } |
33a690c4 | 245 | #else |
f7ce3190 VD |
246 | static inline int init_memcg_params(struct kmem_cache *s, |
247 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
33a690c4 VD |
248 | { |
249 | return 0; | |
250 | } | |
251 | ||
f7ce3190 | 252 | static inline void destroy_memcg_params(struct kmem_cache *s) |
33a690c4 VD |
253 | { |
254 | } | |
657dc2f9 | 255 | |
510ded33 | 256 | static inline void memcg_unlink_cache(struct kmem_cache *s) |
657dc2f9 TH |
257 | { |
258 | } | |
84c07d11 | 259 | #endif /* CONFIG_MEMCG_KMEM */ |
55007d84 | 260 | |
692ae74a BL |
261 | /* |
262 | * Figure out what the alignment of the objects will be given a set of | |
263 | * flags, a user specified alignment and the size of the objects. | |
264 | */ | |
f4957d5b AD |
265 | static unsigned int calculate_alignment(slab_flags_t flags, |
266 | unsigned int align, unsigned int size) | |
692ae74a BL |
267 | { |
268 | /* | |
269 | * If the user wants hardware cache aligned objects then follow that | |
270 | * suggestion if the object is sufficiently large. | |
271 | * | |
272 | * The hardware cache alignment cannot override the specified | |
273 | * alignment though. If that is greater then use it. | |
274 | */ | |
275 | if (flags & SLAB_HWCACHE_ALIGN) { | |
f4957d5b | 276 | unsigned int ralign; |
692ae74a BL |
277 | |
278 | ralign = cache_line_size(); | |
279 | while (size <= ralign / 2) | |
280 | ralign /= 2; | |
281 | align = max(align, ralign); | |
282 | } | |
283 | ||
284 | if (align < ARCH_SLAB_MINALIGN) | |
285 | align = ARCH_SLAB_MINALIGN; | |
286 | ||
287 | return ALIGN(align, sizeof(void *)); | |
288 | } | |
289 | ||
423c929c JK |
290 | /* |
291 | * Find a mergeable slab cache | |
292 | */ | |
293 | int slab_unmergeable(struct kmem_cache *s) | |
294 | { | |
295 | if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) | |
296 | return 1; | |
297 | ||
298 | if (!is_root_cache(s)) | |
299 | return 1; | |
300 | ||
301 | if (s->ctor) | |
302 | return 1; | |
303 | ||
8eb8284b DW |
304 | if (s->usersize) |
305 | return 1; | |
306 | ||
423c929c JK |
307 | /* |
308 | * We may have set a slab to be unmergeable during bootstrap. | |
309 | */ | |
310 | if (s->refcount < 0) | |
311 | return 1; | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
f4957d5b | 316 | struct kmem_cache *find_mergeable(unsigned int size, unsigned int align, |
d50112ed | 317 | slab_flags_t flags, const char *name, void (*ctor)(void *)) |
423c929c JK |
318 | { |
319 | struct kmem_cache *s; | |
320 | ||
c6e28895 | 321 | if (slab_nomerge) |
423c929c JK |
322 | return NULL; |
323 | ||
324 | if (ctor) | |
325 | return NULL; | |
326 | ||
327 | size = ALIGN(size, sizeof(void *)); | |
328 | align = calculate_alignment(flags, align, size); | |
329 | size = ALIGN(size, align); | |
330 | flags = kmem_cache_flags(size, flags, name, NULL); | |
331 | ||
c6e28895 GM |
332 | if (flags & SLAB_NEVER_MERGE) |
333 | return NULL; | |
334 | ||
510ded33 | 335 | list_for_each_entry_reverse(s, &slab_root_caches, root_caches_node) { |
423c929c JK |
336 | if (slab_unmergeable(s)) |
337 | continue; | |
338 | ||
339 | if (size > s->size) | |
340 | continue; | |
341 | ||
342 | if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) | |
343 | continue; | |
344 | /* | |
345 | * Check if alignment is compatible. | |
346 | * Courtesy of Adrian Drzewiecki | |
347 | */ | |
348 | if ((s->size & ~(align - 1)) != s->size) | |
349 | continue; | |
350 | ||
351 | if (s->size - size >= sizeof(void *)) | |
352 | continue; | |
353 | ||
95069ac8 JK |
354 | if (IS_ENABLED(CONFIG_SLAB) && align && |
355 | (align > s->align || s->align % align)) | |
356 | continue; | |
357 | ||
423c929c JK |
358 | return s; |
359 | } | |
360 | return NULL; | |
361 | } | |
362 | ||
c9a77a79 | 363 | static struct kmem_cache *create_cache(const char *name, |
613a5eb5 | 364 | unsigned int object_size, unsigned int align, |
7bbdb81e AD |
365 | slab_flags_t flags, unsigned int useroffset, |
366 | unsigned int usersize, void (*ctor)(void *), | |
c9a77a79 | 367 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) |
794b1248 VD |
368 | { |
369 | struct kmem_cache *s; | |
370 | int err; | |
371 | ||
8eb8284b DW |
372 | if (WARN_ON(useroffset + usersize > object_size)) |
373 | useroffset = usersize = 0; | |
374 | ||
794b1248 VD |
375 | err = -ENOMEM; |
376 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); | |
377 | if (!s) | |
378 | goto out; | |
379 | ||
380 | s->name = name; | |
613a5eb5 | 381 | s->size = s->object_size = object_size; |
794b1248 VD |
382 | s->align = align; |
383 | s->ctor = ctor; | |
8eb8284b DW |
384 | s->useroffset = useroffset; |
385 | s->usersize = usersize; | |
794b1248 | 386 | |
f7ce3190 | 387 | err = init_memcg_params(s, memcg, root_cache); |
794b1248 VD |
388 | if (err) |
389 | goto out_free_cache; | |
390 | ||
391 | err = __kmem_cache_create(s, flags); | |
392 | if (err) | |
393 | goto out_free_cache; | |
394 | ||
395 | s->refcount = 1; | |
396 | list_add(&s->list, &slab_caches); | |
510ded33 | 397 | memcg_link_cache(s); |
794b1248 VD |
398 | out: |
399 | if (err) | |
400 | return ERR_PTR(err); | |
401 | return s; | |
402 | ||
403 | out_free_cache: | |
f7ce3190 | 404 | destroy_memcg_params(s); |
7c4da061 | 405 | kmem_cache_free(kmem_cache, s); |
794b1248 VD |
406 | goto out; |
407 | } | |
45906855 | 408 | |
f496990f MR |
409 | /** |
410 | * kmem_cache_create_usercopy - Create a cache with a region suitable | |
411 | * for copying to userspace | |
77be4b13 SK |
412 | * @name: A string which is used in /proc/slabinfo to identify this cache. |
413 | * @size: The size of objects to be created in this cache. | |
414 | * @align: The required alignment for the objects. | |
415 | * @flags: SLAB flags | |
8eb8284b DW |
416 | * @useroffset: Usercopy region offset |
417 | * @usersize: Usercopy region size | |
77be4b13 SK |
418 | * @ctor: A constructor for the objects. |
419 | * | |
77be4b13 SK |
420 | * Cannot be called within a interrupt, but can be interrupted. |
421 | * The @ctor is run when new pages are allocated by the cache. | |
422 | * | |
423 | * The flags are | |
424 | * | |
425 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
426 | * to catch references to uninitialised memory. | |
427 | * | |
f496990f | 428 | * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check |
77be4b13 SK |
429 | * for buffer overruns. |
430 | * | |
431 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
432 | * cacheline. This can be beneficial if you're counting cycles as closely | |
433 | * as davem. | |
f496990f MR |
434 | * |
435 | * Return: a pointer to the cache on success, NULL on failure. | |
77be4b13 | 436 | */ |
2633d7a0 | 437 | struct kmem_cache * |
f4957d5b AD |
438 | kmem_cache_create_usercopy(const char *name, |
439 | unsigned int size, unsigned int align, | |
7bbdb81e AD |
440 | slab_flags_t flags, |
441 | unsigned int useroffset, unsigned int usersize, | |
8eb8284b | 442 | void (*ctor)(void *)) |
77be4b13 | 443 | { |
40911a79 | 444 | struct kmem_cache *s = NULL; |
3dec16ea | 445 | const char *cache_name; |
3965fc36 | 446 | int err; |
039363f3 | 447 | |
77be4b13 | 448 | get_online_cpus(); |
03afc0e2 | 449 | get_online_mems(); |
05257a1a | 450 | memcg_get_cache_ids(); |
03afc0e2 | 451 | |
77be4b13 | 452 | mutex_lock(&slab_mutex); |
686d550d | 453 | |
794b1248 | 454 | err = kmem_cache_sanity_check(name, size); |
3aa24f51 | 455 | if (err) { |
3965fc36 | 456 | goto out_unlock; |
3aa24f51 | 457 | } |
686d550d | 458 | |
e70954fd TG |
459 | /* Refuse requests with allocator specific flags */ |
460 | if (flags & ~SLAB_FLAGS_PERMITTED) { | |
461 | err = -EINVAL; | |
462 | goto out_unlock; | |
463 | } | |
464 | ||
d8843922 GC |
465 | /* |
466 | * Some allocators will constraint the set of valid flags to a subset | |
467 | * of all flags. We expect them to define CACHE_CREATE_MASK in this | |
468 | * case, and we'll just provide them with a sanitized version of the | |
469 | * passed flags. | |
470 | */ | |
471 | flags &= CACHE_CREATE_MASK; | |
686d550d | 472 | |
8eb8284b DW |
473 | /* Fail closed on bad usersize of useroffset values. */ |
474 | if (WARN_ON(!usersize && useroffset) || | |
475 | WARN_ON(size < usersize || size - usersize < useroffset)) | |
476 | usersize = useroffset = 0; | |
477 | ||
478 | if (!usersize) | |
479 | s = __kmem_cache_alias(name, size, align, flags, ctor); | |
794b1248 | 480 | if (s) |
3965fc36 | 481 | goto out_unlock; |
2633d7a0 | 482 | |
3dec16ea | 483 | cache_name = kstrdup_const(name, GFP_KERNEL); |
794b1248 VD |
484 | if (!cache_name) { |
485 | err = -ENOMEM; | |
486 | goto out_unlock; | |
487 | } | |
7c9adf5a | 488 | |
613a5eb5 | 489 | s = create_cache(cache_name, size, |
c9a77a79 | 490 | calculate_alignment(flags, align, size), |
8eb8284b | 491 | flags, useroffset, usersize, ctor, NULL, NULL); |
794b1248 VD |
492 | if (IS_ERR(s)) { |
493 | err = PTR_ERR(s); | |
3dec16ea | 494 | kfree_const(cache_name); |
794b1248 | 495 | } |
3965fc36 VD |
496 | |
497 | out_unlock: | |
20cea968 | 498 | mutex_unlock(&slab_mutex); |
03afc0e2 | 499 | |
05257a1a | 500 | memcg_put_cache_ids(); |
03afc0e2 | 501 | put_online_mems(); |
20cea968 CL |
502 | put_online_cpus(); |
503 | ||
ba3253c7 | 504 | if (err) { |
686d550d CL |
505 | if (flags & SLAB_PANIC) |
506 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
507 | name, err); | |
508 | else { | |
1170532b | 509 | pr_warn("kmem_cache_create(%s) failed with error %d\n", |
686d550d CL |
510 | name, err); |
511 | dump_stack(); | |
512 | } | |
686d550d CL |
513 | return NULL; |
514 | } | |
039363f3 CL |
515 | return s; |
516 | } | |
8eb8284b DW |
517 | EXPORT_SYMBOL(kmem_cache_create_usercopy); |
518 | ||
f496990f MR |
519 | /** |
520 | * kmem_cache_create - Create a cache. | |
521 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
522 | * @size: The size of objects to be created in this cache. | |
523 | * @align: The required alignment for the objects. | |
524 | * @flags: SLAB flags | |
525 | * @ctor: A constructor for the objects. | |
526 | * | |
527 | * Cannot be called within a interrupt, but can be interrupted. | |
528 | * The @ctor is run when new pages are allocated by the cache. | |
529 | * | |
530 | * The flags are | |
531 | * | |
532 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
533 | * to catch references to uninitialised memory. | |
534 | * | |
535 | * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check | |
536 | * for buffer overruns. | |
537 | * | |
538 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
539 | * cacheline. This can be beneficial if you're counting cycles as closely | |
540 | * as davem. | |
541 | * | |
542 | * Return: a pointer to the cache on success, NULL on failure. | |
543 | */ | |
8eb8284b | 544 | struct kmem_cache * |
f4957d5b | 545 | kmem_cache_create(const char *name, unsigned int size, unsigned int align, |
8eb8284b DW |
546 | slab_flags_t flags, void (*ctor)(void *)) |
547 | { | |
6d07d1cd | 548 | return kmem_cache_create_usercopy(name, size, align, flags, 0, 0, |
8eb8284b DW |
549 | ctor); |
550 | } | |
794b1248 | 551 | EXPORT_SYMBOL(kmem_cache_create); |
2633d7a0 | 552 | |
657dc2f9 | 553 | static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work) |
d5b3cf71 | 554 | { |
657dc2f9 TH |
555 | LIST_HEAD(to_destroy); |
556 | struct kmem_cache *s, *s2; | |
d5b3cf71 | 557 | |
657dc2f9 | 558 | /* |
5f0d5a3a | 559 | * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the |
657dc2f9 TH |
560 | * @slab_caches_to_rcu_destroy list. The slab pages are freed |
561 | * through RCU and and the associated kmem_cache are dereferenced | |
562 | * while freeing the pages, so the kmem_caches should be freed only | |
563 | * after the pending RCU operations are finished. As rcu_barrier() | |
564 | * is a pretty slow operation, we batch all pending destructions | |
565 | * asynchronously. | |
566 | */ | |
567 | mutex_lock(&slab_mutex); | |
568 | list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy); | |
569 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 570 | |
657dc2f9 TH |
571 | if (list_empty(&to_destroy)) |
572 | return; | |
573 | ||
574 | rcu_barrier(); | |
575 | ||
576 | list_for_each_entry_safe(s, s2, &to_destroy, list) { | |
577 | #ifdef SLAB_SUPPORTS_SYSFS | |
578 | sysfs_slab_release(s); | |
579 | #else | |
580 | slab_kmem_cache_release(s); | |
581 | #endif | |
582 | } | |
d5b3cf71 VD |
583 | } |
584 | ||
657dc2f9 | 585 | static int shutdown_cache(struct kmem_cache *s) |
d5b3cf71 | 586 | { |
f9fa1d91 GT |
587 | /* free asan quarantined objects */ |
588 | kasan_cache_shutdown(s); | |
589 | ||
657dc2f9 TH |
590 | if (__kmem_cache_shutdown(s) != 0) |
591 | return -EBUSY; | |
d5b3cf71 | 592 | |
510ded33 | 593 | memcg_unlink_cache(s); |
657dc2f9 | 594 | list_del(&s->list); |
d5b3cf71 | 595 | |
5f0d5a3a | 596 | if (s->flags & SLAB_TYPESAFE_BY_RCU) { |
d50d82fa MP |
597 | #ifdef SLAB_SUPPORTS_SYSFS |
598 | sysfs_slab_unlink(s); | |
599 | #endif | |
657dc2f9 TH |
600 | list_add_tail(&s->list, &slab_caches_to_rcu_destroy); |
601 | schedule_work(&slab_caches_to_rcu_destroy_work); | |
602 | } else { | |
d5b3cf71 | 603 | #ifdef SLAB_SUPPORTS_SYSFS |
d50d82fa | 604 | sysfs_slab_unlink(s); |
bf5eb3de | 605 | sysfs_slab_release(s); |
d5b3cf71 VD |
606 | #else |
607 | slab_kmem_cache_release(s); | |
608 | #endif | |
609 | } | |
657dc2f9 TH |
610 | |
611 | return 0; | |
d5b3cf71 VD |
612 | } |
613 | ||
84c07d11 | 614 | #ifdef CONFIG_MEMCG_KMEM |
794b1248 | 615 | /* |
776ed0f0 | 616 | * memcg_create_kmem_cache - Create a cache for a memory cgroup. |
794b1248 VD |
617 | * @memcg: The memory cgroup the new cache is for. |
618 | * @root_cache: The parent of the new cache. | |
619 | * | |
620 | * This function attempts to create a kmem cache that will serve allocation | |
621 | * requests going from @memcg to @root_cache. The new cache inherits properties | |
622 | * from its parent. | |
623 | */ | |
d5b3cf71 VD |
624 | void memcg_create_kmem_cache(struct mem_cgroup *memcg, |
625 | struct kmem_cache *root_cache) | |
2633d7a0 | 626 | { |
3e0350a3 | 627 | static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */ |
33398cf2 | 628 | struct cgroup_subsys_state *css = &memcg->css; |
f7ce3190 | 629 | struct memcg_cache_array *arr; |
bd673145 | 630 | struct kmem_cache *s = NULL; |
794b1248 | 631 | char *cache_name; |
f7ce3190 | 632 | int idx; |
794b1248 VD |
633 | |
634 | get_online_cpus(); | |
03afc0e2 VD |
635 | get_online_mems(); |
636 | ||
794b1248 VD |
637 | mutex_lock(&slab_mutex); |
638 | ||
2a4db7eb | 639 | /* |
567e9ab2 | 640 | * The memory cgroup could have been offlined while the cache |
2a4db7eb VD |
641 | * creation work was pending. |
642 | */ | |
92ee383f | 643 | if (memcg->kmem_state != KMEM_ONLINE || root_cache->memcg_params.dying) |
2a4db7eb VD |
644 | goto out_unlock; |
645 | ||
f7ce3190 VD |
646 | idx = memcg_cache_id(memcg); |
647 | arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches, | |
648 | lockdep_is_held(&slab_mutex)); | |
649 | ||
d5b3cf71 VD |
650 | /* |
651 | * Since per-memcg caches are created asynchronously on first | |
652 | * allocation (see memcg_kmem_get_cache()), several threads can try to | |
653 | * create the same cache, but only one of them may succeed. | |
654 | */ | |
f7ce3190 | 655 | if (arr->entries[idx]) |
d5b3cf71 VD |
656 | goto out_unlock; |
657 | ||
f1008365 | 658 | cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf)); |
73f576c0 JW |
659 | cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name, |
660 | css->serial_nr, memcg_name_buf); | |
794b1248 VD |
661 | if (!cache_name) |
662 | goto out_unlock; | |
663 | ||
c9a77a79 | 664 | s = create_cache(cache_name, root_cache->object_size, |
613a5eb5 | 665 | root_cache->align, |
f773e36d | 666 | root_cache->flags & CACHE_CREATE_MASK, |
8eb8284b | 667 | root_cache->useroffset, root_cache->usersize, |
f773e36d | 668 | root_cache->ctor, memcg, root_cache); |
d5b3cf71 VD |
669 | /* |
670 | * If we could not create a memcg cache, do not complain, because | |
671 | * that's not critical at all as we can always proceed with the root | |
672 | * cache. | |
673 | */ | |
bd673145 | 674 | if (IS_ERR(s)) { |
794b1248 | 675 | kfree(cache_name); |
d5b3cf71 | 676 | goto out_unlock; |
bd673145 | 677 | } |
794b1248 | 678 | |
d5b3cf71 VD |
679 | /* |
680 | * Since readers won't lock (see cache_from_memcg_idx()), we need a | |
681 | * barrier here to ensure nobody will see the kmem_cache partially | |
682 | * initialized. | |
683 | */ | |
684 | smp_wmb(); | |
f7ce3190 | 685 | arr->entries[idx] = s; |
d5b3cf71 | 686 | |
794b1248 VD |
687 | out_unlock: |
688 | mutex_unlock(&slab_mutex); | |
03afc0e2 VD |
689 | |
690 | put_online_mems(); | |
794b1248 | 691 | put_online_cpus(); |
2633d7a0 | 692 | } |
b8529907 | 693 | |
01fb58bc TH |
694 | static void kmemcg_deactivate_workfn(struct work_struct *work) |
695 | { | |
696 | struct kmem_cache *s = container_of(work, struct kmem_cache, | |
697 | memcg_params.deact_work); | |
698 | ||
699 | get_online_cpus(); | |
700 | get_online_mems(); | |
701 | ||
702 | mutex_lock(&slab_mutex); | |
703 | ||
704 | s->memcg_params.deact_fn(s); | |
705 | ||
706 | mutex_unlock(&slab_mutex); | |
707 | ||
708 | put_online_mems(); | |
709 | put_online_cpus(); | |
710 | ||
711 | /* done, put the ref from slab_deactivate_memcg_cache_rcu_sched() */ | |
712 | css_put(&s->memcg_params.memcg->css); | |
713 | } | |
714 | ||
715 | static void kmemcg_deactivate_rcufn(struct rcu_head *head) | |
716 | { | |
717 | struct kmem_cache *s = container_of(head, struct kmem_cache, | |
718 | memcg_params.deact_rcu_head); | |
719 | ||
720 | /* | |
721 | * We need to grab blocking locks. Bounce to ->deact_work. The | |
722 | * work item shares the space with the RCU head and can't be | |
723 | * initialized eariler. | |
724 | */ | |
725 | INIT_WORK(&s->memcg_params.deact_work, kmemcg_deactivate_workfn); | |
17cc4dfe | 726 | queue_work(memcg_kmem_cache_wq, &s->memcg_params.deact_work); |
01fb58bc TH |
727 | } |
728 | ||
729 | /** | |
730 | * slab_deactivate_memcg_cache_rcu_sched - schedule deactivation after a | |
731 | * sched RCU grace period | |
732 | * @s: target kmem_cache | |
733 | * @deact_fn: deactivation function to call | |
734 | * | |
735 | * Schedule @deact_fn to be invoked with online cpus, mems and slab_mutex | |
736 | * held after a sched RCU grace period. The slab is guaranteed to stay | |
737 | * alive until @deact_fn is finished. This is to be used from | |
738 | * __kmemcg_cache_deactivate(). | |
739 | */ | |
740 | void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, | |
741 | void (*deact_fn)(struct kmem_cache *)) | |
742 | { | |
743 | if (WARN_ON_ONCE(is_root_cache(s)) || | |
744 | WARN_ON_ONCE(s->memcg_params.deact_fn)) | |
745 | return; | |
746 | ||
92ee383f SB |
747 | if (s->memcg_params.root_cache->memcg_params.dying) |
748 | return; | |
749 | ||
01fb58bc TH |
750 | /* pin memcg so that @s doesn't get destroyed in the middle */ |
751 | css_get(&s->memcg_params.memcg->css); | |
752 | ||
753 | s->memcg_params.deact_fn = deact_fn; | |
6564a25e | 754 | call_rcu(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn); |
01fb58bc TH |
755 | } |
756 | ||
2a4db7eb VD |
757 | void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) |
758 | { | |
759 | int idx; | |
760 | struct memcg_cache_array *arr; | |
d6e0b7fa | 761 | struct kmem_cache *s, *c; |
2a4db7eb VD |
762 | |
763 | idx = memcg_cache_id(memcg); | |
764 | ||
d6e0b7fa VD |
765 | get_online_cpus(); |
766 | get_online_mems(); | |
767 | ||
2a4db7eb | 768 | mutex_lock(&slab_mutex); |
510ded33 | 769 | list_for_each_entry(s, &slab_root_caches, root_caches_node) { |
2a4db7eb VD |
770 | arr = rcu_dereference_protected(s->memcg_params.memcg_caches, |
771 | lockdep_is_held(&slab_mutex)); | |
d6e0b7fa VD |
772 | c = arr->entries[idx]; |
773 | if (!c) | |
774 | continue; | |
775 | ||
c9fc5864 | 776 | __kmemcg_cache_deactivate(c); |
2a4db7eb VD |
777 | arr->entries[idx] = NULL; |
778 | } | |
779 | mutex_unlock(&slab_mutex); | |
d6e0b7fa VD |
780 | |
781 | put_online_mems(); | |
782 | put_online_cpus(); | |
2a4db7eb VD |
783 | } |
784 | ||
d5b3cf71 | 785 | void memcg_destroy_kmem_caches(struct mem_cgroup *memcg) |
b8529907 | 786 | { |
d5b3cf71 | 787 | struct kmem_cache *s, *s2; |
b8529907 | 788 | |
d5b3cf71 VD |
789 | get_online_cpus(); |
790 | get_online_mems(); | |
b8529907 | 791 | |
b8529907 | 792 | mutex_lock(&slab_mutex); |
bc2791f8 TH |
793 | list_for_each_entry_safe(s, s2, &memcg->kmem_caches, |
794 | memcg_params.kmem_caches_node) { | |
d5b3cf71 VD |
795 | /* |
796 | * The cgroup is about to be freed and therefore has no charges | |
797 | * left. Hence, all its caches must be empty by now. | |
798 | */ | |
657dc2f9 | 799 | BUG_ON(shutdown_cache(s)); |
d5b3cf71 VD |
800 | } |
801 | mutex_unlock(&slab_mutex); | |
b8529907 | 802 | |
d5b3cf71 VD |
803 | put_online_mems(); |
804 | put_online_cpus(); | |
b8529907 | 805 | } |
d60fdcc9 | 806 | |
657dc2f9 | 807 | static int shutdown_memcg_caches(struct kmem_cache *s) |
d60fdcc9 VD |
808 | { |
809 | struct memcg_cache_array *arr; | |
810 | struct kmem_cache *c, *c2; | |
811 | LIST_HEAD(busy); | |
812 | int i; | |
813 | ||
814 | BUG_ON(!is_root_cache(s)); | |
815 | ||
816 | /* | |
817 | * First, shutdown active caches, i.e. caches that belong to online | |
818 | * memory cgroups. | |
819 | */ | |
820 | arr = rcu_dereference_protected(s->memcg_params.memcg_caches, | |
821 | lockdep_is_held(&slab_mutex)); | |
822 | for_each_memcg_cache_index(i) { | |
823 | c = arr->entries[i]; | |
824 | if (!c) | |
825 | continue; | |
657dc2f9 | 826 | if (shutdown_cache(c)) |
d60fdcc9 VD |
827 | /* |
828 | * The cache still has objects. Move it to a temporary | |
829 | * list so as not to try to destroy it for a second | |
830 | * time while iterating over inactive caches below. | |
831 | */ | |
9eeadc8b | 832 | list_move(&c->memcg_params.children_node, &busy); |
d60fdcc9 VD |
833 | else |
834 | /* | |
835 | * The cache is empty and will be destroyed soon. Clear | |
836 | * the pointer to it in the memcg_caches array so that | |
837 | * it will never be accessed even if the root cache | |
838 | * stays alive. | |
839 | */ | |
840 | arr->entries[i] = NULL; | |
841 | } | |
842 | ||
843 | /* | |
844 | * Second, shutdown all caches left from memory cgroups that are now | |
845 | * offline. | |
846 | */ | |
9eeadc8b TH |
847 | list_for_each_entry_safe(c, c2, &s->memcg_params.children, |
848 | memcg_params.children_node) | |
657dc2f9 | 849 | shutdown_cache(c); |
d60fdcc9 | 850 | |
9eeadc8b | 851 | list_splice(&busy, &s->memcg_params.children); |
d60fdcc9 VD |
852 | |
853 | /* | |
854 | * A cache being destroyed must be empty. In particular, this means | |
855 | * that all per memcg caches attached to it must be empty too. | |
856 | */ | |
9eeadc8b | 857 | if (!list_empty(&s->memcg_params.children)) |
d60fdcc9 VD |
858 | return -EBUSY; |
859 | return 0; | |
860 | } | |
92ee383f SB |
861 | |
862 | static void flush_memcg_workqueue(struct kmem_cache *s) | |
863 | { | |
864 | mutex_lock(&slab_mutex); | |
865 | s->memcg_params.dying = true; | |
866 | mutex_unlock(&slab_mutex); | |
867 | ||
868 | /* | |
6564a25e | 869 | * SLUB deactivates the kmem_caches through call_rcu. Make |
92ee383f SB |
870 | * sure all registered rcu callbacks have been invoked. |
871 | */ | |
872 | if (IS_ENABLED(CONFIG_SLUB)) | |
6564a25e | 873 | rcu_barrier(); |
92ee383f SB |
874 | |
875 | /* | |
876 | * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB | |
877 | * deactivates the memcg kmem_caches through workqueue. Make sure all | |
878 | * previous workitems on workqueue are processed. | |
879 | */ | |
880 | flush_workqueue(memcg_kmem_cache_wq); | |
881 | } | |
d60fdcc9 | 882 | #else |
657dc2f9 | 883 | static inline int shutdown_memcg_caches(struct kmem_cache *s) |
d60fdcc9 VD |
884 | { |
885 | return 0; | |
886 | } | |
92ee383f SB |
887 | |
888 | static inline void flush_memcg_workqueue(struct kmem_cache *s) | |
889 | { | |
890 | } | |
84c07d11 | 891 | #endif /* CONFIG_MEMCG_KMEM */ |
97d06609 | 892 | |
41a21285 CL |
893 | void slab_kmem_cache_release(struct kmem_cache *s) |
894 | { | |
52b4b950 | 895 | __kmem_cache_release(s); |
f7ce3190 | 896 | destroy_memcg_params(s); |
3dec16ea | 897 | kfree_const(s->name); |
41a21285 CL |
898 | kmem_cache_free(kmem_cache, s); |
899 | } | |
900 | ||
945cf2b6 CL |
901 | void kmem_cache_destroy(struct kmem_cache *s) |
902 | { | |
d60fdcc9 | 903 | int err; |
d5b3cf71 | 904 | |
3942d299 SS |
905 | if (unlikely(!s)) |
906 | return; | |
907 | ||
92ee383f SB |
908 | flush_memcg_workqueue(s); |
909 | ||
945cf2b6 | 910 | get_online_cpus(); |
03afc0e2 VD |
911 | get_online_mems(); |
912 | ||
945cf2b6 | 913 | mutex_lock(&slab_mutex); |
b8529907 | 914 | |
945cf2b6 | 915 | s->refcount--; |
b8529907 VD |
916 | if (s->refcount) |
917 | goto out_unlock; | |
918 | ||
657dc2f9 | 919 | err = shutdown_memcg_caches(s); |
d60fdcc9 | 920 | if (!err) |
657dc2f9 | 921 | err = shutdown_cache(s); |
b8529907 | 922 | |
cd918c55 | 923 | if (err) { |
756a025f JP |
924 | pr_err("kmem_cache_destroy %s: Slab cache still has objects\n", |
925 | s->name); | |
cd918c55 VD |
926 | dump_stack(); |
927 | } | |
b8529907 VD |
928 | out_unlock: |
929 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 930 | |
03afc0e2 | 931 | put_online_mems(); |
945cf2b6 CL |
932 | put_online_cpus(); |
933 | } | |
934 | EXPORT_SYMBOL(kmem_cache_destroy); | |
935 | ||
03afc0e2 VD |
936 | /** |
937 | * kmem_cache_shrink - Shrink a cache. | |
938 | * @cachep: The cache to shrink. | |
939 | * | |
940 | * Releases as many slabs as possible for a cache. | |
941 | * To help debugging, a zero exit status indicates all slabs were released. | |
a862f68a MR |
942 | * |
943 | * Return: %0 if all slabs were released, non-zero otherwise | |
03afc0e2 VD |
944 | */ |
945 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
946 | { | |
947 | int ret; | |
948 | ||
949 | get_online_cpus(); | |
950 | get_online_mems(); | |
55834c59 | 951 | kasan_cache_shrink(cachep); |
c9fc5864 | 952 | ret = __kmem_cache_shrink(cachep); |
03afc0e2 VD |
953 | put_online_mems(); |
954 | put_online_cpus(); | |
955 | return ret; | |
956 | } | |
957 | EXPORT_SYMBOL(kmem_cache_shrink); | |
958 | ||
fda90124 | 959 | bool slab_is_available(void) |
97d06609 CL |
960 | { |
961 | return slab_state >= UP; | |
962 | } | |
b7454ad3 | 963 | |
45530c44 CL |
964 | #ifndef CONFIG_SLOB |
965 | /* Create a cache during boot when no slab services are available yet */ | |
361d575e AD |
966 | void __init create_boot_cache(struct kmem_cache *s, const char *name, |
967 | unsigned int size, slab_flags_t flags, | |
968 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
969 | { |
970 | int err; | |
971 | ||
972 | s->name = name; | |
973 | s->size = s->object_size = size; | |
45906855 | 974 | s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size); |
8eb8284b DW |
975 | s->useroffset = useroffset; |
976 | s->usersize = usersize; | |
f7ce3190 VD |
977 | |
978 | slab_init_memcg_params(s); | |
979 | ||
45530c44 CL |
980 | err = __kmem_cache_create(s, flags); |
981 | ||
982 | if (err) | |
361d575e | 983 | panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n", |
45530c44 CL |
984 | name, size, err); |
985 | ||
986 | s->refcount = -1; /* Exempt from merging for now */ | |
987 | } | |
988 | ||
55de8b9c AD |
989 | struct kmem_cache *__init create_kmalloc_cache(const char *name, |
990 | unsigned int size, slab_flags_t flags, | |
991 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
992 | { |
993 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); | |
994 | ||
995 | if (!s) | |
996 | panic("Out of memory when creating slab %s\n", name); | |
997 | ||
6c0c21ad | 998 | create_boot_cache(s, name, size, flags, useroffset, usersize); |
45530c44 | 999 | list_add(&s->list, &slab_caches); |
510ded33 | 1000 | memcg_link_cache(s); |
45530c44 CL |
1001 | s->refcount = 1; |
1002 | return s; | |
1003 | } | |
1004 | ||
cc252eae VB |
1005 | struct kmem_cache * |
1006 | kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init; | |
9425c58e CL |
1007 | EXPORT_SYMBOL(kmalloc_caches); |
1008 | ||
2c59dd65 CL |
1009 | /* |
1010 | * Conversion table for small slabs sizes / 8 to the index in the | |
1011 | * kmalloc array. This is necessary for slabs < 192 since we have non power | |
1012 | * of two cache sizes there. The size of larger slabs can be determined using | |
1013 | * fls. | |
1014 | */ | |
d5f86655 | 1015 | static u8 size_index[24] __ro_after_init = { |
2c59dd65 CL |
1016 | 3, /* 8 */ |
1017 | 4, /* 16 */ | |
1018 | 5, /* 24 */ | |
1019 | 5, /* 32 */ | |
1020 | 6, /* 40 */ | |
1021 | 6, /* 48 */ | |
1022 | 6, /* 56 */ | |
1023 | 6, /* 64 */ | |
1024 | 1, /* 72 */ | |
1025 | 1, /* 80 */ | |
1026 | 1, /* 88 */ | |
1027 | 1, /* 96 */ | |
1028 | 7, /* 104 */ | |
1029 | 7, /* 112 */ | |
1030 | 7, /* 120 */ | |
1031 | 7, /* 128 */ | |
1032 | 2, /* 136 */ | |
1033 | 2, /* 144 */ | |
1034 | 2, /* 152 */ | |
1035 | 2, /* 160 */ | |
1036 | 2, /* 168 */ | |
1037 | 2, /* 176 */ | |
1038 | 2, /* 184 */ | |
1039 | 2 /* 192 */ | |
1040 | }; | |
1041 | ||
ac914d08 | 1042 | static inline unsigned int size_index_elem(unsigned int bytes) |
2c59dd65 CL |
1043 | { |
1044 | return (bytes - 1) / 8; | |
1045 | } | |
1046 | ||
1047 | /* | |
1048 | * Find the kmem_cache structure that serves a given size of | |
1049 | * allocation | |
1050 | */ | |
1051 | struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) | |
1052 | { | |
d5f86655 | 1053 | unsigned int index; |
2c59dd65 CL |
1054 | |
1055 | if (size <= 192) { | |
1056 | if (!size) | |
1057 | return ZERO_SIZE_PTR; | |
1058 | ||
1059 | index = size_index[size_index_elem(size)]; | |
61448479 | 1060 | } else { |
221d7da6 | 1061 | if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE)) |
61448479 | 1062 | return NULL; |
2c59dd65 | 1063 | index = fls(size - 1); |
61448479 | 1064 | } |
2c59dd65 | 1065 | |
cc252eae | 1066 | return kmalloc_caches[kmalloc_type(flags)][index]; |
2c59dd65 CL |
1067 | } |
1068 | ||
4066c33d GG |
1069 | /* |
1070 | * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time. | |
1071 | * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is | |
1072 | * kmalloc-67108864. | |
1073 | */ | |
af3b5f87 | 1074 | const struct kmalloc_info_struct kmalloc_info[] __initconst = { |
4066c33d GG |
1075 | {NULL, 0}, {"kmalloc-96", 96}, |
1076 | {"kmalloc-192", 192}, {"kmalloc-8", 8}, | |
1077 | {"kmalloc-16", 16}, {"kmalloc-32", 32}, | |
1078 | {"kmalloc-64", 64}, {"kmalloc-128", 128}, | |
1079 | {"kmalloc-256", 256}, {"kmalloc-512", 512}, | |
f0d77874 VB |
1080 | {"kmalloc-1k", 1024}, {"kmalloc-2k", 2048}, |
1081 | {"kmalloc-4k", 4096}, {"kmalloc-8k", 8192}, | |
1082 | {"kmalloc-16k", 16384}, {"kmalloc-32k", 32768}, | |
1083 | {"kmalloc-64k", 65536}, {"kmalloc-128k", 131072}, | |
1084 | {"kmalloc-256k", 262144}, {"kmalloc-512k", 524288}, | |
1085 | {"kmalloc-1M", 1048576}, {"kmalloc-2M", 2097152}, | |
1086 | {"kmalloc-4M", 4194304}, {"kmalloc-8M", 8388608}, | |
1087 | {"kmalloc-16M", 16777216}, {"kmalloc-32M", 33554432}, | |
1088 | {"kmalloc-64M", 67108864} | |
4066c33d GG |
1089 | }; |
1090 | ||
f97d5f63 | 1091 | /* |
34cc6990 DS |
1092 | * Patch up the size_index table if we have strange large alignment |
1093 | * requirements for the kmalloc array. This is only the case for | |
1094 | * MIPS it seems. The standard arches will not generate any code here. | |
1095 | * | |
1096 | * Largest permitted alignment is 256 bytes due to the way we | |
1097 | * handle the index determination for the smaller caches. | |
1098 | * | |
1099 | * Make sure that nothing crazy happens if someone starts tinkering | |
1100 | * around with ARCH_KMALLOC_MINALIGN | |
f97d5f63 | 1101 | */ |
34cc6990 | 1102 | void __init setup_kmalloc_cache_index_table(void) |
f97d5f63 | 1103 | { |
ac914d08 | 1104 | unsigned int i; |
f97d5f63 | 1105 | |
2c59dd65 CL |
1106 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || |
1107 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); | |
1108 | ||
1109 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { | |
ac914d08 | 1110 | unsigned int elem = size_index_elem(i); |
2c59dd65 CL |
1111 | |
1112 | if (elem >= ARRAY_SIZE(size_index)) | |
1113 | break; | |
1114 | size_index[elem] = KMALLOC_SHIFT_LOW; | |
1115 | } | |
1116 | ||
1117 | if (KMALLOC_MIN_SIZE >= 64) { | |
1118 | /* | |
1119 | * The 96 byte size cache is not used if the alignment | |
1120 | * is 64 byte. | |
1121 | */ | |
1122 | for (i = 64 + 8; i <= 96; i += 8) | |
1123 | size_index[size_index_elem(i)] = 7; | |
1124 | ||
1125 | } | |
1126 | ||
1127 | if (KMALLOC_MIN_SIZE >= 128) { | |
1128 | /* | |
1129 | * The 192 byte sized cache is not used if the alignment | |
1130 | * is 128 byte. Redirect kmalloc to use the 256 byte cache | |
1131 | * instead. | |
1132 | */ | |
1133 | for (i = 128 + 8; i <= 192; i += 8) | |
1134 | size_index[size_index_elem(i)] = 8; | |
1135 | } | |
34cc6990 DS |
1136 | } |
1137 | ||
f0d77874 VB |
1138 | static const char * |
1139 | kmalloc_cache_name(const char *prefix, unsigned int size) | |
1140 | { | |
1141 | ||
1142 | static const char units[3] = "\0kM"; | |
1143 | int idx = 0; | |
1144 | ||
1145 | while (size >= 1024 && (size % 1024 == 0)) { | |
1146 | size /= 1024; | |
1147 | idx++; | |
1148 | } | |
1149 | ||
1150 | return kasprintf(GFP_NOWAIT, "%s-%u%c", prefix, size, units[idx]); | |
1151 | } | |
1152 | ||
1291523f VB |
1153 | static void __init |
1154 | new_kmalloc_cache(int idx, int type, slab_flags_t flags) | |
a9730fca | 1155 | { |
1291523f VB |
1156 | const char *name; |
1157 | ||
1158 | if (type == KMALLOC_RECLAIM) { | |
1159 | flags |= SLAB_RECLAIM_ACCOUNT; | |
f0d77874 | 1160 | name = kmalloc_cache_name("kmalloc-rcl", |
1291523f VB |
1161 | kmalloc_info[idx].size); |
1162 | BUG_ON(!name); | |
1163 | } else { | |
1164 | name = kmalloc_info[idx].name; | |
1165 | } | |
1166 | ||
1167 | kmalloc_caches[type][idx] = create_kmalloc_cache(name, | |
6c0c21ad DW |
1168 | kmalloc_info[idx].size, flags, 0, |
1169 | kmalloc_info[idx].size); | |
a9730fca CL |
1170 | } |
1171 | ||
34cc6990 DS |
1172 | /* |
1173 | * Create the kmalloc array. Some of the regular kmalloc arrays | |
1174 | * may already have been created because they were needed to | |
1175 | * enable allocations for slab creation. | |
1176 | */ | |
d50112ed | 1177 | void __init create_kmalloc_caches(slab_flags_t flags) |
34cc6990 | 1178 | { |
1291523f | 1179 | int i, type; |
34cc6990 | 1180 | |
1291523f VB |
1181 | for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) { |
1182 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { | |
1183 | if (!kmalloc_caches[type][i]) | |
1184 | new_kmalloc_cache(i, type, flags); | |
f97d5f63 | 1185 | |
1291523f VB |
1186 | /* |
1187 | * Caches that are not of the two-to-the-power-of size. | |
1188 | * These have to be created immediately after the | |
1189 | * earlier power of two caches | |
1190 | */ | |
1191 | if (KMALLOC_MIN_SIZE <= 32 && i == 6 && | |
1192 | !kmalloc_caches[type][1]) | |
1193 | new_kmalloc_cache(1, type, flags); | |
1194 | if (KMALLOC_MIN_SIZE <= 64 && i == 7 && | |
1195 | !kmalloc_caches[type][2]) | |
1196 | new_kmalloc_cache(2, type, flags); | |
1197 | } | |
8a965b3b CL |
1198 | } |
1199 | ||
f97d5f63 CL |
1200 | /* Kmalloc array is now usable */ |
1201 | slab_state = UP; | |
1202 | ||
f97d5f63 CL |
1203 | #ifdef CONFIG_ZONE_DMA |
1204 | for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { | |
cc252eae | 1205 | struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i]; |
f97d5f63 CL |
1206 | |
1207 | if (s) { | |
0be70327 | 1208 | unsigned int size = kmalloc_size(i); |
f0d77874 | 1209 | const char *n = kmalloc_cache_name("dma-kmalloc", size); |
f97d5f63 CL |
1210 | |
1211 | BUG_ON(!n); | |
cc252eae VB |
1212 | kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( |
1213 | n, size, SLAB_CACHE_DMA | flags, 0, 0); | |
f97d5f63 CL |
1214 | } |
1215 | } | |
1216 | #endif | |
1217 | } | |
45530c44 CL |
1218 | #endif /* !CONFIG_SLOB */ |
1219 | ||
cea371f4 VD |
1220 | /* |
1221 | * To avoid unnecessary overhead, we pass through large allocation requests | |
1222 | * directly to the page allocator. We use __GFP_COMP, because we will need to | |
1223 | * know the allocation order to free the pages properly in kfree. | |
1224 | */ | |
52383431 VD |
1225 | void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) |
1226 | { | |
1227 | void *ret; | |
1228 | struct page *page; | |
1229 | ||
1230 | flags |= __GFP_COMP; | |
4949148a | 1231 | page = alloc_pages(flags, order); |
52383431 | 1232 | ret = page ? page_address(page) : NULL; |
0116523c | 1233 | ret = kasan_kmalloc_large(ret, size, flags); |
a2f77575 | 1234 | /* As ret might get tagged, call kmemleak hook after KASAN. */ |
53128245 | 1235 | kmemleak_alloc(ret, size, 1, flags); |
52383431 VD |
1236 | return ret; |
1237 | } | |
1238 | EXPORT_SYMBOL(kmalloc_order); | |
1239 | ||
f1b6eb6e CL |
1240 | #ifdef CONFIG_TRACING |
1241 | void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) | |
1242 | { | |
1243 | void *ret = kmalloc_order(size, flags, order); | |
1244 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags); | |
1245 | return ret; | |
1246 | } | |
1247 | EXPORT_SYMBOL(kmalloc_order_trace); | |
1248 | #endif | |
45530c44 | 1249 | |
7c00fce9 TG |
1250 | #ifdef CONFIG_SLAB_FREELIST_RANDOM |
1251 | /* Randomize a generic freelist */ | |
1252 | static void freelist_randomize(struct rnd_state *state, unsigned int *list, | |
302d55d5 | 1253 | unsigned int count) |
7c00fce9 | 1254 | { |
7c00fce9 | 1255 | unsigned int rand; |
302d55d5 | 1256 | unsigned int i; |
7c00fce9 TG |
1257 | |
1258 | for (i = 0; i < count; i++) | |
1259 | list[i] = i; | |
1260 | ||
1261 | /* Fisher-Yates shuffle */ | |
1262 | for (i = count - 1; i > 0; i--) { | |
1263 | rand = prandom_u32_state(state); | |
1264 | rand %= (i + 1); | |
1265 | swap(list[i], list[rand]); | |
1266 | } | |
1267 | } | |
1268 | ||
1269 | /* Create a random sequence per cache */ | |
1270 | int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, | |
1271 | gfp_t gfp) | |
1272 | { | |
1273 | struct rnd_state state; | |
1274 | ||
1275 | if (count < 2 || cachep->random_seq) | |
1276 | return 0; | |
1277 | ||
1278 | cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp); | |
1279 | if (!cachep->random_seq) | |
1280 | return -ENOMEM; | |
1281 | ||
1282 | /* Get best entropy at this stage of boot */ | |
1283 | prandom_seed_state(&state, get_random_long()); | |
1284 | ||
1285 | freelist_randomize(&state, cachep->random_seq, count); | |
1286 | return 0; | |
1287 | } | |
1288 | ||
1289 | /* Destroy the per-cache random freelist sequence */ | |
1290 | void cache_random_seq_destroy(struct kmem_cache *cachep) | |
1291 | { | |
1292 | kfree(cachep->random_seq); | |
1293 | cachep->random_seq = NULL; | |
1294 | } | |
1295 | #endif /* CONFIG_SLAB_FREELIST_RANDOM */ | |
1296 | ||
5b365771 | 1297 | #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) |
e9b4db2b | 1298 | #ifdef CONFIG_SLAB |
0825a6f9 | 1299 | #define SLABINFO_RIGHTS (0600) |
e9b4db2b | 1300 | #else |
0825a6f9 | 1301 | #define SLABINFO_RIGHTS (0400) |
e9b4db2b WL |
1302 | #endif |
1303 | ||
b047501c | 1304 | static void print_slabinfo_header(struct seq_file *m) |
bcee6e2a GC |
1305 | { |
1306 | /* | |
1307 | * Output format version, so at least we can change it | |
1308 | * without _too_ many complaints. | |
1309 | */ | |
1310 | #ifdef CONFIG_DEBUG_SLAB | |
1311 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
1312 | #else | |
1313 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
1314 | #endif | |
756a025f | 1315 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); |
bcee6e2a GC |
1316 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
1317 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
1318 | #ifdef CONFIG_DEBUG_SLAB | |
756a025f | 1319 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); |
bcee6e2a GC |
1320 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); |
1321 | #endif | |
1322 | seq_putc(m, '\n'); | |
1323 | } | |
1324 | ||
1df3b26f | 1325 | void *slab_start(struct seq_file *m, loff_t *pos) |
b7454ad3 | 1326 | { |
b7454ad3 | 1327 | mutex_lock(&slab_mutex); |
510ded33 | 1328 | return seq_list_start(&slab_root_caches, *pos); |
b7454ad3 GC |
1329 | } |
1330 | ||
276a2439 | 1331 | void *slab_next(struct seq_file *m, void *p, loff_t *pos) |
b7454ad3 | 1332 | { |
510ded33 | 1333 | return seq_list_next(p, &slab_root_caches, pos); |
b7454ad3 GC |
1334 | } |
1335 | ||
276a2439 | 1336 | void slab_stop(struct seq_file *m, void *p) |
b7454ad3 GC |
1337 | { |
1338 | mutex_unlock(&slab_mutex); | |
1339 | } | |
1340 | ||
749c5415 GC |
1341 | static void |
1342 | memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info) | |
1343 | { | |
1344 | struct kmem_cache *c; | |
1345 | struct slabinfo sinfo; | |
749c5415 GC |
1346 | |
1347 | if (!is_root_cache(s)) | |
1348 | return; | |
1349 | ||
426589f5 | 1350 | for_each_memcg_cache(c, s) { |
749c5415 GC |
1351 | memset(&sinfo, 0, sizeof(sinfo)); |
1352 | get_slabinfo(c, &sinfo); | |
1353 | ||
1354 | info->active_slabs += sinfo.active_slabs; | |
1355 | info->num_slabs += sinfo.num_slabs; | |
1356 | info->shared_avail += sinfo.shared_avail; | |
1357 | info->active_objs += sinfo.active_objs; | |
1358 | info->num_objs += sinfo.num_objs; | |
1359 | } | |
1360 | } | |
1361 | ||
b047501c | 1362 | static void cache_show(struct kmem_cache *s, struct seq_file *m) |
b7454ad3 | 1363 | { |
0d7561c6 GC |
1364 | struct slabinfo sinfo; |
1365 | ||
1366 | memset(&sinfo, 0, sizeof(sinfo)); | |
1367 | get_slabinfo(s, &sinfo); | |
1368 | ||
749c5415 GC |
1369 | memcg_accumulate_slabinfo(s, &sinfo); |
1370 | ||
0d7561c6 | 1371 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
749c5415 | 1372 | cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, |
0d7561c6 GC |
1373 | sinfo.objects_per_slab, (1 << sinfo.cache_order)); |
1374 | ||
1375 | seq_printf(m, " : tunables %4u %4u %4u", | |
1376 | sinfo.limit, sinfo.batchcount, sinfo.shared); | |
1377 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
1378 | sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); | |
1379 | slabinfo_show_stats(m, s); | |
1380 | seq_putc(m, '\n'); | |
b7454ad3 GC |
1381 | } |
1382 | ||
1df3b26f | 1383 | static int slab_show(struct seq_file *m, void *p) |
749c5415 | 1384 | { |
510ded33 | 1385 | struct kmem_cache *s = list_entry(p, struct kmem_cache, root_caches_node); |
749c5415 | 1386 | |
510ded33 | 1387 | if (p == slab_root_caches.next) |
1df3b26f | 1388 | print_slabinfo_header(m); |
510ded33 | 1389 | cache_show(s, m); |
b047501c VD |
1390 | return 0; |
1391 | } | |
1392 | ||
852d8be0 YS |
1393 | void dump_unreclaimable_slab(void) |
1394 | { | |
1395 | struct kmem_cache *s, *s2; | |
1396 | struct slabinfo sinfo; | |
1397 | ||
1398 | /* | |
1399 | * Here acquiring slab_mutex is risky since we don't prefer to get | |
1400 | * sleep in oom path. But, without mutex hold, it may introduce a | |
1401 | * risk of crash. | |
1402 | * Use mutex_trylock to protect the list traverse, dump nothing | |
1403 | * without acquiring the mutex. | |
1404 | */ | |
1405 | if (!mutex_trylock(&slab_mutex)) { | |
1406 | pr_warn("excessive unreclaimable slab but cannot dump stats\n"); | |
1407 | return; | |
1408 | } | |
1409 | ||
1410 | pr_info("Unreclaimable slab info:\n"); | |
1411 | pr_info("Name Used Total\n"); | |
1412 | ||
1413 | list_for_each_entry_safe(s, s2, &slab_caches, list) { | |
1414 | if (!is_root_cache(s) || (s->flags & SLAB_RECLAIM_ACCOUNT)) | |
1415 | continue; | |
1416 | ||
1417 | get_slabinfo(s, &sinfo); | |
1418 | ||
1419 | if (sinfo.num_objs > 0) | |
1420 | pr_info("%-17s %10luKB %10luKB\n", cache_name(s), | |
1421 | (sinfo.active_objs * s->size) / 1024, | |
1422 | (sinfo.num_objs * s->size) / 1024); | |
1423 | } | |
1424 | mutex_unlock(&slab_mutex); | |
1425 | } | |
1426 | ||
5b365771 | 1427 | #if defined(CONFIG_MEMCG) |
bc2791f8 TH |
1428 | void *memcg_slab_start(struct seq_file *m, loff_t *pos) |
1429 | { | |
aa9694bb | 1430 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
bc2791f8 TH |
1431 | |
1432 | mutex_lock(&slab_mutex); | |
1433 | return seq_list_start(&memcg->kmem_caches, *pos); | |
1434 | } | |
1435 | ||
1436 | void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos) | |
1437 | { | |
aa9694bb | 1438 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
bc2791f8 TH |
1439 | |
1440 | return seq_list_next(p, &memcg->kmem_caches, pos); | |
1441 | } | |
1442 | ||
1443 | void memcg_slab_stop(struct seq_file *m, void *p) | |
1444 | { | |
1445 | mutex_unlock(&slab_mutex); | |
1446 | } | |
1447 | ||
b047501c VD |
1448 | int memcg_slab_show(struct seq_file *m, void *p) |
1449 | { | |
bc2791f8 TH |
1450 | struct kmem_cache *s = list_entry(p, struct kmem_cache, |
1451 | memcg_params.kmem_caches_node); | |
aa9694bb | 1452 | struct mem_cgroup *memcg = mem_cgroup_from_seq(m); |
b047501c | 1453 | |
bc2791f8 | 1454 | if (p == memcg->kmem_caches.next) |
b047501c | 1455 | print_slabinfo_header(m); |
bc2791f8 | 1456 | cache_show(s, m); |
b047501c | 1457 | return 0; |
749c5415 | 1458 | } |
b047501c | 1459 | #endif |
749c5415 | 1460 | |
b7454ad3 GC |
1461 | /* |
1462 | * slabinfo_op - iterator that generates /proc/slabinfo | |
1463 | * | |
1464 | * Output layout: | |
1465 | * cache-name | |
1466 | * num-active-objs | |
1467 | * total-objs | |
1468 | * object size | |
1469 | * num-active-slabs | |
1470 | * total-slabs | |
1471 | * num-pages-per-slab | |
1472 | * + further values on SMP and with statistics enabled | |
1473 | */ | |
1474 | static const struct seq_operations slabinfo_op = { | |
1df3b26f | 1475 | .start = slab_start, |
276a2439 WL |
1476 | .next = slab_next, |
1477 | .stop = slab_stop, | |
1df3b26f | 1478 | .show = slab_show, |
b7454ad3 GC |
1479 | }; |
1480 | ||
1481 | static int slabinfo_open(struct inode *inode, struct file *file) | |
1482 | { | |
1483 | return seq_open(file, &slabinfo_op); | |
1484 | } | |
1485 | ||
1486 | static const struct file_operations proc_slabinfo_operations = { | |
1487 | .open = slabinfo_open, | |
1488 | .read = seq_read, | |
1489 | .write = slabinfo_write, | |
1490 | .llseek = seq_lseek, | |
1491 | .release = seq_release, | |
1492 | }; | |
1493 | ||
1494 | static int __init slab_proc_init(void) | |
1495 | { | |
e9b4db2b WL |
1496 | proc_create("slabinfo", SLABINFO_RIGHTS, NULL, |
1497 | &proc_slabinfo_operations); | |
b7454ad3 GC |
1498 | return 0; |
1499 | } | |
1500 | module_init(slab_proc_init); | |
5b365771 | 1501 | #endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */ |
928cec9c AR |
1502 | |
1503 | static __always_inline void *__do_krealloc(const void *p, size_t new_size, | |
1504 | gfp_t flags) | |
1505 | { | |
1506 | void *ret; | |
1507 | size_t ks = 0; | |
1508 | ||
1509 | if (p) | |
1510 | ks = ksize(p); | |
1511 | ||
0316bec2 | 1512 | if (ks >= new_size) { |
0116523c | 1513 | p = kasan_krealloc((void *)p, new_size, flags); |
928cec9c | 1514 | return (void *)p; |
0316bec2 | 1515 | } |
928cec9c AR |
1516 | |
1517 | ret = kmalloc_track_caller(new_size, flags); | |
1518 | if (ret && p) | |
1519 | memcpy(ret, p, ks); | |
1520 | ||
1521 | return ret; | |
1522 | } | |
1523 | ||
1524 | /** | |
1525 | * __krealloc - like krealloc() but don't free @p. | |
1526 | * @p: object to reallocate memory for. | |
1527 | * @new_size: how many bytes of memory are required. | |
1528 | * @flags: the type of memory to allocate. | |
1529 | * | |
1530 | * This function is like krealloc() except it never frees the originally | |
1531 | * allocated buffer. Use this if you don't want to free the buffer immediately | |
1532 | * like, for example, with RCU. | |
a862f68a MR |
1533 | * |
1534 | * Return: pointer to the allocated memory or %NULL in case of error | |
928cec9c AR |
1535 | */ |
1536 | void *__krealloc(const void *p, size_t new_size, gfp_t flags) | |
1537 | { | |
1538 | if (unlikely(!new_size)) | |
1539 | return ZERO_SIZE_PTR; | |
1540 | ||
1541 | return __do_krealloc(p, new_size, flags); | |
1542 | ||
1543 | } | |
1544 | EXPORT_SYMBOL(__krealloc); | |
1545 | ||
1546 | /** | |
1547 | * krealloc - reallocate memory. The contents will remain unchanged. | |
1548 | * @p: object to reallocate memory for. | |
1549 | * @new_size: how many bytes of memory are required. | |
1550 | * @flags: the type of memory to allocate. | |
1551 | * | |
1552 | * The contents of the object pointed to are preserved up to the | |
1553 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
1554 | * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a | |
1555 | * %NULL pointer, the object pointed to is freed. | |
a862f68a MR |
1556 | * |
1557 | * Return: pointer to the allocated memory or %NULL in case of error | |
928cec9c AR |
1558 | */ |
1559 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
1560 | { | |
1561 | void *ret; | |
1562 | ||
1563 | if (unlikely(!new_size)) { | |
1564 | kfree(p); | |
1565 | return ZERO_SIZE_PTR; | |
1566 | } | |
1567 | ||
1568 | ret = __do_krealloc(p, new_size, flags); | |
772a2fa5 | 1569 | if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret)) |
928cec9c AR |
1570 | kfree(p); |
1571 | ||
1572 | return ret; | |
1573 | } | |
1574 | EXPORT_SYMBOL(krealloc); | |
1575 | ||
1576 | /** | |
1577 | * kzfree - like kfree but zero memory | |
1578 | * @p: object to free memory of | |
1579 | * | |
1580 | * The memory of the object @p points to is zeroed before freed. | |
1581 | * If @p is %NULL, kzfree() does nothing. | |
1582 | * | |
1583 | * Note: this function zeroes the whole allocated buffer which can be a good | |
1584 | * deal bigger than the requested buffer size passed to kmalloc(). So be | |
1585 | * careful when using this function in performance sensitive code. | |
1586 | */ | |
1587 | void kzfree(const void *p) | |
1588 | { | |
1589 | size_t ks; | |
1590 | void *mem = (void *)p; | |
1591 | ||
1592 | if (unlikely(ZERO_OR_NULL_PTR(mem))) | |
1593 | return; | |
1594 | ks = ksize(mem); | |
1595 | memset(mem, 0, ks); | |
1596 | kfree(mem); | |
1597 | } | |
1598 | EXPORT_SYMBOL(kzfree); | |
1599 | ||
1600 | /* Tracepoints definitions. */ | |
1601 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); | |
1602 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); | |
1603 | EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); | |
1604 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); | |
1605 | EXPORT_TRACEPOINT_SYMBOL(kfree); | |
1606 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); | |
4f6923fb HM |
1607 | |
1608 | int should_failslab(struct kmem_cache *s, gfp_t gfpflags) | |
1609 | { | |
1610 | if (__should_failslab(s, gfpflags)) | |
1611 | return -ENOMEM; | |
1612 | return 0; | |
1613 | } | |
1614 | ALLOW_ERROR_INJECTION(should_failslab, ERRNO); |