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> | |
fcf8a1e4 | 20 | #include <linux/debugfs.h> |
039363f3 CL |
21 | #include <asm/cacheflush.h> |
22 | #include <asm/tlbflush.h> | |
23 | #include <asm/page.h> | |
2633d7a0 | 24 | #include <linux/memcontrol.h> |
928cec9c AR |
25 | |
26 | #define CREATE_TRACE_POINTS | |
f1b6eb6e | 27 | #include <trace/events/kmem.h> |
039363f3 | 28 | |
44405099 LL |
29 | #include "internal.h" |
30 | ||
97d06609 CL |
31 | #include "slab.h" |
32 | ||
33 | enum slab_state slab_state; | |
18004c5d CL |
34 | LIST_HEAD(slab_caches); |
35 | DEFINE_MUTEX(slab_mutex); | |
9b030cb8 | 36 | struct kmem_cache *kmem_cache; |
97d06609 | 37 | |
2d891fbc KC |
38 | #ifdef CONFIG_HARDENED_USERCOPY |
39 | bool usercopy_fallback __ro_after_init = | |
40 | IS_ENABLED(CONFIG_HARDENED_USERCOPY_FALLBACK); | |
41 | module_param(usercopy_fallback, bool, 0400); | |
42 | MODULE_PARM_DESC(usercopy_fallback, | |
43 | "WARN instead of reject usercopy whitelist violations"); | |
44 | #endif | |
45 | ||
657dc2f9 TH |
46 | static LIST_HEAD(slab_caches_to_rcu_destroy); |
47 | static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work); | |
48 | static DECLARE_WORK(slab_caches_to_rcu_destroy_work, | |
49 | slab_caches_to_rcu_destroy_workfn); | |
50 | ||
423c929c JK |
51 | /* |
52 | * Set of flags that will prevent slab merging | |
53 | */ | |
54 | #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
5f0d5a3a | 55 | SLAB_TRACE | SLAB_TYPESAFE_BY_RCU | SLAB_NOLEAKTRACE | \ |
7ed2f9e6 | 56 | SLAB_FAILSLAB | SLAB_KASAN) |
423c929c | 57 | |
230e9fc2 | 58 | #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ |
6d6ea1e9 | 59 | SLAB_CACHE_DMA32 | SLAB_ACCOUNT) |
423c929c JK |
60 | |
61 | /* | |
62 | * Merge control. If this is set then no merging of slab caches will occur. | |
423c929c | 63 | */ |
7660a6fd | 64 | static bool slab_nomerge = !IS_ENABLED(CONFIG_SLAB_MERGE_DEFAULT); |
423c929c JK |
65 | |
66 | static int __init setup_slab_nomerge(char *str) | |
67 | { | |
7660a6fd | 68 | slab_nomerge = true; |
423c929c JK |
69 | return 1; |
70 | } | |
71 | ||
72 | #ifdef CONFIG_SLUB | |
73 | __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0); | |
74 | #endif | |
75 | ||
76 | __setup("slab_nomerge", setup_slab_nomerge); | |
77 | ||
07f361b2 JK |
78 | /* |
79 | * Determine the size of a slab object | |
80 | */ | |
81 | unsigned int kmem_cache_size(struct kmem_cache *s) | |
82 | { | |
83 | return s->object_size; | |
84 | } | |
85 | EXPORT_SYMBOL(kmem_cache_size); | |
86 | ||
77be4b13 | 87 | #ifdef CONFIG_DEBUG_VM |
f4957d5b | 88 | static int kmem_cache_sanity_check(const char *name, unsigned int size) |
039363f3 | 89 | { |
039363f3 CL |
90 | if (!name || in_interrupt() || size < sizeof(void *) || |
91 | size > KMALLOC_MAX_SIZE) { | |
77be4b13 SK |
92 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); |
93 | return -EINVAL; | |
039363f3 | 94 | } |
b920536a | 95 | |
20cea968 | 96 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ |
77be4b13 SK |
97 | return 0; |
98 | } | |
99 | #else | |
f4957d5b | 100 | static inline int kmem_cache_sanity_check(const char *name, unsigned int size) |
77be4b13 SK |
101 | { |
102 | return 0; | |
103 | } | |
20cea968 CL |
104 | #endif |
105 | ||
484748f0 CL |
106 | void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p) |
107 | { | |
108 | size_t i; | |
109 | ||
ca257195 JDB |
110 | for (i = 0; i < nr; i++) { |
111 | if (s) | |
112 | kmem_cache_free(s, p[i]); | |
113 | else | |
114 | kfree(p[i]); | |
115 | } | |
484748f0 CL |
116 | } |
117 | ||
865762a8 | 118 | int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr, |
484748f0 CL |
119 | void **p) |
120 | { | |
121 | size_t i; | |
122 | ||
123 | for (i = 0; i < nr; i++) { | |
124 | void *x = p[i] = kmem_cache_alloc(s, flags); | |
125 | if (!x) { | |
126 | __kmem_cache_free_bulk(s, i, p); | |
865762a8 | 127 | return 0; |
484748f0 CL |
128 | } |
129 | } | |
865762a8 | 130 | return i; |
484748f0 CL |
131 | } |
132 | ||
692ae74a BL |
133 | /* |
134 | * Figure out what the alignment of the objects will be given a set of | |
135 | * flags, a user specified alignment and the size of the objects. | |
136 | */ | |
f4957d5b AD |
137 | static unsigned int calculate_alignment(slab_flags_t flags, |
138 | unsigned int align, unsigned int size) | |
692ae74a BL |
139 | { |
140 | /* | |
141 | * If the user wants hardware cache aligned objects then follow that | |
142 | * suggestion if the object is sufficiently large. | |
143 | * | |
144 | * The hardware cache alignment cannot override the specified | |
145 | * alignment though. If that is greater then use it. | |
146 | */ | |
147 | if (flags & SLAB_HWCACHE_ALIGN) { | |
f4957d5b | 148 | unsigned int ralign; |
692ae74a BL |
149 | |
150 | ralign = cache_line_size(); | |
151 | while (size <= ralign / 2) | |
152 | ralign /= 2; | |
153 | align = max(align, ralign); | |
154 | } | |
155 | ||
156 | if (align < ARCH_SLAB_MINALIGN) | |
157 | align = ARCH_SLAB_MINALIGN; | |
158 | ||
159 | return ALIGN(align, sizeof(void *)); | |
160 | } | |
161 | ||
423c929c JK |
162 | /* |
163 | * Find a mergeable slab cache | |
164 | */ | |
165 | int slab_unmergeable(struct kmem_cache *s) | |
166 | { | |
167 | if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) | |
168 | return 1; | |
169 | ||
423c929c JK |
170 | if (s->ctor) |
171 | return 1; | |
172 | ||
8eb8284b DW |
173 | if (s->usersize) |
174 | return 1; | |
175 | ||
423c929c JK |
176 | /* |
177 | * We may have set a slab to be unmergeable during bootstrap. | |
178 | */ | |
179 | if (s->refcount < 0) | |
180 | return 1; | |
181 | ||
182 | return 0; | |
183 | } | |
184 | ||
f4957d5b | 185 | struct kmem_cache *find_mergeable(unsigned int size, unsigned int align, |
d50112ed | 186 | slab_flags_t flags, const char *name, void (*ctor)(void *)) |
423c929c JK |
187 | { |
188 | struct kmem_cache *s; | |
189 | ||
c6e28895 | 190 | if (slab_nomerge) |
423c929c JK |
191 | return NULL; |
192 | ||
193 | if (ctor) | |
194 | return NULL; | |
195 | ||
196 | size = ALIGN(size, sizeof(void *)); | |
197 | align = calculate_alignment(flags, align, size); | |
198 | size = ALIGN(size, align); | |
199 | flags = kmem_cache_flags(size, flags, name, NULL); | |
200 | ||
c6e28895 GM |
201 | if (flags & SLAB_NEVER_MERGE) |
202 | return NULL; | |
203 | ||
c7094406 | 204 | list_for_each_entry_reverse(s, &slab_caches, list) { |
423c929c JK |
205 | if (slab_unmergeable(s)) |
206 | continue; | |
207 | ||
208 | if (size > s->size) | |
209 | continue; | |
210 | ||
211 | if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) | |
212 | continue; | |
213 | /* | |
214 | * Check if alignment is compatible. | |
215 | * Courtesy of Adrian Drzewiecki | |
216 | */ | |
217 | if ((s->size & ~(align - 1)) != s->size) | |
218 | continue; | |
219 | ||
220 | if (s->size - size >= sizeof(void *)) | |
221 | continue; | |
222 | ||
95069ac8 JK |
223 | if (IS_ENABLED(CONFIG_SLAB) && align && |
224 | (align > s->align || s->align % align)) | |
225 | continue; | |
226 | ||
423c929c JK |
227 | return s; |
228 | } | |
229 | return NULL; | |
230 | } | |
231 | ||
c9a77a79 | 232 | static struct kmem_cache *create_cache(const char *name, |
613a5eb5 | 233 | unsigned int object_size, unsigned int align, |
7bbdb81e AD |
234 | slab_flags_t flags, unsigned int useroffset, |
235 | unsigned int usersize, void (*ctor)(void *), | |
9855609b | 236 | struct kmem_cache *root_cache) |
794b1248 VD |
237 | { |
238 | struct kmem_cache *s; | |
239 | int err; | |
240 | ||
8eb8284b DW |
241 | if (WARN_ON(useroffset + usersize > object_size)) |
242 | useroffset = usersize = 0; | |
243 | ||
794b1248 VD |
244 | err = -ENOMEM; |
245 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); | |
246 | if (!s) | |
247 | goto out; | |
248 | ||
249 | s->name = name; | |
613a5eb5 | 250 | s->size = s->object_size = object_size; |
794b1248 VD |
251 | s->align = align; |
252 | s->ctor = ctor; | |
8eb8284b DW |
253 | s->useroffset = useroffset; |
254 | s->usersize = usersize; | |
794b1248 | 255 | |
794b1248 VD |
256 | err = __kmem_cache_create(s, flags); |
257 | if (err) | |
258 | goto out_free_cache; | |
259 | ||
260 | s->refcount = 1; | |
261 | list_add(&s->list, &slab_caches); | |
794b1248 VD |
262 | out: |
263 | if (err) | |
264 | return ERR_PTR(err); | |
265 | return s; | |
266 | ||
267 | out_free_cache: | |
7c4da061 | 268 | kmem_cache_free(kmem_cache, s); |
794b1248 VD |
269 | goto out; |
270 | } | |
45906855 | 271 | |
f496990f MR |
272 | /** |
273 | * kmem_cache_create_usercopy - Create a cache with a region suitable | |
274 | * for copying to userspace | |
77be4b13 SK |
275 | * @name: A string which is used in /proc/slabinfo to identify this cache. |
276 | * @size: The size of objects to be created in this cache. | |
277 | * @align: The required alignment for the objects. | |
278 | * @flags: SLAB flags | |
8eb8284b DW |
279 | * @useroffset: Usercopy region offset |
280 | * @usersize: Usercopy region size | |
77be4b13 SK |
281 | * @ctor: A constructor for the objects. |
282 | * | |
77be4b13 SK |
283 | * Cannot be called within a interrupt, but can be interrupted. |
284 | * The @ctor is run when new pages are allocated by the cache. | |
285 | * | |
286 | * The flags are | |
287 | * | |
288 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
289 | * to catch references to uninitialised memory. | |
290 | * | |
f496990f | 291 | * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check |
77be4b13 SK |
292 | * for buffer overruns. |
293 | * | |
294 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
295 | * cacheline. This can be beneficial if you're counting cycles as closely | |
296 | * as davem. | |
f496990f MR |
297 | * |
298 | * Return: a pointer to the cache on success, NULL on failure. | |
77be4b13 | 299 | */ |
2633d7a0 | 300 | struct kmem_cache * |
f4957d5b AD |
301 | kmem_cache_create_usercopy(const char *name, |
302 | unsigned int size, unsigned int align, | |
7bbdb81e AD |
303 | slab_flags_t flags, |
304 | unsigned int useroffset, unsigned int usersize, | |
8eb8284b | 305 | void (*ctor)(void *)) |
77be4b13 | 306 | { |
40911a79 | 307 | struct kmem_cache *s = NULL; |
3dec16ea | 308 | const char *cache_name; |
3965fc36 | 309 | int err; |
039363f3 | 310 | |
77be4b13 | 311 | get_online_cpus(); |
03afc0e2 VD |
312 | get_online_mems(); |
313 | ||
77be4b13 | 314 | mutex_lock(&slab_mutex); |
686d550d | 315 | |
794b1248 | 316 | err = kmem_cache_sanity_check(name, size); |
3aa24f51 | 317 | if (err) { |
3965fc36 | 318 | goto out_unlock; |
3aa24f51 | 319 | } |
686d550d | 320 | |
e70954fd TG |
321 | /* Refuse requests with allocator specific flags */ |
322 | if (flags & ~SLAB_FLAGS_PERMITTED) { | |
323 | err = -EINVAL; | |
324 | goto out_unlock; | |
325 | } | |
326 | ||
d8843922 GC |
327 | /* |
328 | * Some allocators will constraint the set of valid flags to a subset | |
329 | * of all flags. We expect them to define CACHE_CREATE_MASK in this | |
330 | * case, and we'll just provide them with a sanitized version of the | |
331 | * passed flags. | |
332 | */ | |
333 | flags &= CACHE_CREATE_MASK; | |
686d550d | 334 | |
8eb8284b DW |
335 | /* Fail closed on bad usersize of useroffset values. */ |
336 | if (WARN_ON(!usersize && useroffset) || | |
337 | WARN_ON(size < usersize || size - usersize < useroffset)) | |
338 | usersize = useroffset = 0; | |
339 | ||
340 | if (!usersize) | |
341 | s = __kmem_cache_alias(name, size, align, flags, ctor); | |
794b1248 | 342 | if (s) |
3965fc36 | 343 | goto out_unlock; |
2633d7a0 | 344 | |
3dec16ea | 345 | cache_name = kstrdup_const(name, GFP_KERNEL); |
794b1248 VD |
346 | if (!cache_name) { |
347 | err = -ENOMEM; | |
348 | goto out_unlock; | |
349 | } | |
7c9adf5a | 350 | |
613a5eb5 | 351 | s = create_cache(cache_name, size, |
c9a77a79 | 352 | calculate_alignment(flags, align, size), |
9855609b | 353 | flags, useroffset, usersize, ctor, NULL); |
794b1248 VD |
354 | if (IS_ERR(s)) { |
355 | err = PTR_ERR(s); | |
3dec16ea | 356 | kfree_const(cache_name); |
794b1248 | 357 | } |
3965fc36 VD |
358 | |
359 | out_unlock: | |
20cea968 | 360 | mutex_unlock(&slab_mutex); |
03afc0e2 VD |
361 | |
362 | put_online_mems(); | |
20cea968 CL |
363 | put_online_cpus(); |
364 | ||
ba3253c7 | 365 | if (err) { |
686d550d CL |
366 | if (flags & SLAB_PANIC) |
367 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
368 | name, err); | |
369 | else { | |
1170532b | 370 | pr_warn("kmem_cache_create(%s) failed with error %d\n", |
686d550d CL |
371 | name, err); |
372 | dump_stack(); | |
373 | } | |
686d550d CL |
374 | return NULL; |
375 | } | |
039363f3 CL |
376 | return s; |
377 | } | |
8eb8284b DW |
378 | EXPORT_SYMBOL(kmem_cache_create_usercopy); |
379 | ||
f496990f MR |
380 | /** |
381 | * kmem_cache_create - Create a cache. | |
382 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
383 | * @size: The size of objects to be created in this cache. | |
384 | * @align: The required alignment for the objects. | |
385 | * @flags: SLAB flags | |
386 | * @ctor: A constructor for the objects. | |
387 | * | |
388 | * Cannot be called within a interrupt, but can be interrupted. | |
389 | * The @ctor is run when new pages are allocated by the cache. | |
390 | * | |
391 | * The flags are | |
392 | * | |
393 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
394 | * to catch references to uninitialised memory. | |
395 | * | |
396 | * %SLAB_RED_ZONE - Insert `Red` zones around the allocated memory to check | |
397 | * for buffer overruns. | |
398 | * | |
399 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
400 | * cacheline. This can be beneficial if you're counting cycles as closely | |
401 | * as davem. | |
402 | * | |
403 | * Return: a pointer to the cache on success, NULL on failure. | |
404 | */ | |
8eb8284b | 405 | struct kmem_cache * |
f4957d5b | 406 | kmem_cache_create(const char *name, unsigned int size, unsigned int align, |
8eb8284b DW |
407 | slab_flags_t flags, void (*ctor)(void *)) |
408 | { | |
6d07d1cd | 409 | return kmem_cache_create_usercopy(name, size, align, flags, 0, 0, |
8eb8284b DW |
410 | ctor); |
411 | } | |
794b1248 | 412 | EXPORT_SYMBOL(kmem_cache_create); |
2633d7a0 | 413 | |
657dc2f9 | 414 | static void slab_caches_to_rcu_destroy_workfn(struct work_struct *work) |
d5b3cf71 | 415 | { |
657dc2f9 TH |
416 | LIST_HEAD(to_destroy); |
417 | struct kmem_cache *s, *s2; | |
d5b3cf71 | 418 | |
657dc2f9 | 419 | /* |
5f0d5a3a | 420 | * On destruction, SLAB_TYPESAFE_BY_RCU kmem_caches are put on the |
657dc2f9 | 421 | * @slab_caches_to_rcu_destroy list. The slab pages are freed |
081a06fa | 422 | * through RCU and the associated kmem_cache are dereferenced |
657dc2f9 TH |
423 | * while freeing the pages, so the kmem_caches should be freed only |
424 | * after the pending RCU operations are finished. As rcu_barrier() | |
425 | * is a pretty slow operation, we batch all pending destructions | |
426 | * asynchronously. | |
427 | */ | |
428 | mutex_lock(&slab_mutex); | |
429 | list_splice_init(&slab_caches_to_rcu_destroy, &to_destroy); | |
430 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 431 | |
657dc2f9 TH |
432 | if (list_empty(&to_destroy)) |
433 | return; | |
434 | ||
435 | rcu_barrier(); | |
436 | ||
437 | list_for_each_entry_safe(s, s2, &to_destroy, list) { | |
438 | #ifdef SLAB_SUPPORTS_SYSFS | |
439 | sysfs_slab_release(s); | |
440 | #else | |
441 | slab_kmem_cache_release(s); | |
442 | #endif | |
443 | } | |
d5b3cf71 VD |
444 | } |
445 | ||
657dc2f9 | 446 | static int shutdown_cache(struct kmem_cache *s) |
d5b3cf71 | 447 | { |
f9fa1d91 GT |
448 | /* free asan quarantined objects */ |
449 | kasan_cache_shutdown(s); | |
450 | ||
657dc2f9 TH |
451 | if (__kmem_cache_shutdown(s) != 0) |
452 | return -EBUSY; | |
d5b3cf71 | 453 | |
657dc2f9 | 454 | list_del(&s->list); |
d5b3cf71 | 455 | |
5f0d5a3a | 456 | if (s->flags & SLAB_TYPESAFE_BY_RCU) { |
d50d82fa MP |
457 | #ifdef SLAB_SUPPORTS_SYSFS |
458 | sysfs_slab_unlink(s); | |
459 | #endif | |
657dc2f9 TH |
460 | list_add_tail(&s->list, &slab_caches_to_rcu_destroy); |
461 | schedule_work(&slab_caches_to_rcu_destroy_work); | |
462 | } else { | |
d5b3cf71 | 463 | #ifdef SLAB_SUPPORTS_SYSFS |
d50d82fa | 464 | sysfs_slab_unlink(s); |
bf5eb3de | 465 | sysfs_slab_release(s); |
d5b3cf71 VD |
466 | #else |
467 | slab_kmem_cache_release(s); | |
468 | #endif | |
469 | } | |
657dc2f9 TH |
470 | |
471 | return 0; | |
d5b3cf71 VD |
472 | } |
473 | ||
41a21285 CL |
474 | void slab_kmem_cache_release(struct kmem_cache *s) |
475 | { | |
52b4b950 | 476 | __kmem_cache_release(s); |
3dec16ea | 477 | kfree_const(s->name); |
41a21285 CL |
478 | kmem_cache_free(kmem_cache, s); |
479 | } | |
480 | ||
945cf2b6 CL |
481 | void kmem_cache_destroy(struct kmem_cache *s) |
482 | { | |
d60fdcc9 | 483 | int err; |
d5b3cf71 | 484 | |
3942d299 SS |
485 | if (unlikely(!s)) |
486 | return; | |
487 | ||
945cf2b6 | 488 | get_online_cpus(); |
03afc0e2 VD |
489 | get_online_mems(); |
490 | ||
945cf2b6 | 491 | mutex_lock(&slab_mutex); |
b8529907 | 492 | |
945cf2b6 | 493 | s->refcount--; |
b8529907 VD |
494 | if (s->refcount) |
495 | goto out_unlock; | |
496 | ||
10befea9 | 497 | err = shutdown_cache(s); |
cd918c55 | 498 | if (err) { |
756a025f JP |
499 | pr_err("kmem_cache_destroy %s: Slab cache still has objects\n", |
500 | s->name); | |
cd918c55 VD |
501 | dump_stack(); |
502 | } | |
b8529907 VD |
503 | out_unlock: |
504 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 505 | |
03afc0e2 | 506 | put_online_mems(); |
945cf2b6 CL |
507 | put_online_cpus(); |
508 | } | |
509 | EXPORT_SYMBOL(kmem_cache_destroy); | |
510 | ||
03afc0e2 VD |
511 | /** |
512 | * kmem_cache_shrink - Shrink a cache. | |
513 | * @cachep: The cache to shrink. | |
514 | * | |
515 | * Releases as many slabs as possible for a cache. | |
516 | * To help debugging, a zero exit status indicates all slabs were released. | |
a862f68a MR |
517 | * |
518 | * Return: %0 if all slabs were released, non-zero otherwise | |
03afc0e2 VD |
519 | */ |
520 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
521 | { | |
522 | int ret; | |
523 | ||
524 | get_online_cpus(); | |
525 | get_online_mems(); | |
55834c59 | 526 | kasan_cache_shrink(cachep); |
c9fc5864 | 527 | ret = __kmem_cache_shrink(cachep); |
03afc0e2 VD |
528 | put_online_mems(); |
529 | put_online_cpus(); | |
530 | return ret; | |
531 | } | |
532 | EXPORT_SYMBOL(kmem_cache_shrink); | |
533 | ||
fda90124 | 534 | bool slab_is_available(void) |
97d06609 CL |
535 | { |
536 | return slab_state >= UP; | |
537 | } | |
b7454ad3 | 538 | |
45530c44 CL |
539 | #ifndef CONFIG_SLOB |
540 | /* Create a cache during boot when no slab services are available yet */ | |
361d575e AD |
541 | void __init create_boot_cache(struct kmem_cache *s, const char *name, |
542 | unsigned int size, slab_flags_t flags, | |
543 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
544 | { |
545 | int err; | |
59bb4798 | 546 | unsigned int align = ARCH_KMALLOC_MINALIGN; |
45530c44 CL |
547 | |
548 | s->name = name; | |
549 | s->size = s->object_size = size; | |
59bb4798 VB |
550 | |
551 | /* | |
552 | * For power of two sizes, guarantee natural alignment for kmalloc | |
553 | * caches, regardless of SL*B debugging options. | |
554 | */ | |
555 | if (is_power_of_2(size)) | |
556 | align = max(align, size); | |
557 | s->align = calculate_alignment(flags, align, size); | |
558 | ||
8eb8284b DW |
559 | s->useroffset = useroffset; |
560 | s->usersize = usersize; | |
f7ce3190 | 561 | |
45530c44 CL |
562 | err = __kmem_cache_create(s, flags); |
563 | ||
564 | if (err) | |
361d575e | 565 | panic("Creation of kmalloc slab %s size=%u failed. Reason %d\n", |
45530c44 CL |
566 | name, size, err); |
567 | ||
568 | s->refcount = -1; /* Exempt from merging for now */ | |
569 | } | |
570 | ||
55de8b9c AD |
571 | struct kmem_cache *__init create_kmalloc_cache(const char *name, |
572 | unsigned int size, slab_flags_t flags, | |
573 | unsigned int useroffset, unsigned int usersize) | |
45530c44 CL |
574 | { |
575 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); | |
576 | ||
577 | if (!s) | |
578 | panic("Out of memory when creating slab %s\n", name); | |
579 | ||
6c0c21ad | 580 | create_boot_cache(s, name, size, flags, useroffset, usersize); |
45530c44 CL |
581 | list_add(&s->list, &slab_caches); |
582 | s->refcount = 1; | |
583 | return s; | |
584 | } | |
585 | ||
cc252eae | 586 | struct kmem_cache * |
a07057dc AB |
587 | kmalloc_caches[NR_KMALLOC_TYPES][KMALLOC_SHIFT_HIGH + 1] __ro_after_init = |
588 | { /* initialization for https://bugs.llvm.org/show_bug.cgi?id=42570 */ }; | |
9425c58e CL |
589 | EXPORT_SYMBOL(kmalloc_caches); |
590 | ||
2c59dd65 CL |
591 | /* |
592 | * Conversion table for small slabs sizes / 8 to the index in the | |
593 | * kmalloc array. This is necessary for slabs < 192 since we have non power | |
594 | * of two cache sizes there. The size of larger slabs can be determined using | |
595 | * fls. | |
596 | */ | |
d5f86655 | 597 | static u8 size_index[24] __ro_after_init = { |
2c59dd65 CL |
598 | 3, /* 8 */ |
599 | 4, /* 16 */ | |
600 | 5, /* 24 */ | |
601 | 5, /* 32 */ | |
602 | 6, /* 40 */ | |
603 | 6, /* 48 */ | |
604 | 6, /* 56 */ | |
605 | 6, /* 64 */ | |
606 | 1, /* 72 */ | |
607 | 1, /* 80 */ | |
608 | 1, /* 88 */ | |
609 | 1, /* 96 */ | |
610 | 7, /* 104 */ | |
611 | 7, /* 112 */ | |
612 | 7, /* 120 */ | |
613 | 7, /* 128 */ | |
614 | 2, /* 136 */ | |
615 | 2, /* 144 */ | |
616 | 2, /* 152 */ | |
617 | 2, /* 160 */ | |
618 | 2, /* 168 */ | |
619 | 2, /* 176 */ | |
620 | 2, /* 184 */ | |
621 | 2 /* 192 */ | |
622 | }; | |
623 | ||
ac914d08 | 624 | static inline unsigned int size_index_elem(unsigned int bytes) |
2c59dd65 CL |
625 | { |
626 | return (bytes - 1) / 8; | |
627 | } | |
628 | ||
629 | /* | |
630 | * Find the kmem_cache structure that serves a given size of | |
631 | * allocation | |
632 | */ | |
633 | struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) | |
634 | { | |
d5f86655 | 635 | unsigned int index; |
2c59dd65 CL |
636 | |
637 | if (size <= 192) { | |
638 | if (!size) | |
639 | return ZERO_SIZE_PTR; | |
640 | ||
641 | index = size_index[size_index_elem(size)]; | |
61448479 | 642 | } else { |
221d7da6 | 643 | if (WARN_ON_ONCE(size > KMALLOC_MAX_CACHE_SIZE)) |
61448479 | 644 | return NULL; |
2c59dd65 | 645 | index = fls(size - 1); |
61448479 | 646 | } |
2c59dd65 | 647 | |
cc252eae | 648 | return kmalloc_caches[kmalloc_type(flags)][index]; |
2c59dd65 CL |
649 | } |
650 | ||
cb5d9fb3 PL |
651 | #ifdef CONFIG_ZONE_DMA |
652 | #define INIT_KMALLOC_INFO(__size, __short_size) \ | |
653 | { \ | |
654 | .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \ | |
655 | .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \ | |
656 | .name[KMALLOC_DMA] = "dma-kmalloc-" #__short_size, \ | |
657 | .size = __size, \ | |
658 | } | |
659 | #else | |
660 | #define INIT_KMALLOC_INFO(__size, __short_size) \ | |
661 | { \ | |
662 | .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \ | |
663 | .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \ | |
664 | .size = __size, \ | |
665 | } | |
666 | #endif | |
667 | ||
4066c33d GG |
668 | /* |
669 | * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time. | |
670 | * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is | |
671 | * kmalloc-67108864. | |
672 | */ | |
af3b5f87 | 673 | const struct kmalloc_info_struct kmalloc_info[] __initconst = { |
cb5d9fb3 PL |
674 | INIT_KMALLOC_INFO(0, 0), |
675 | INIT_KMALLOC_INFO(96, 96), | |
676 | INIT_KMALLOC_INFO(192, 192), | |
677 | INIT_KMALLOC_INFO(8, 8), | |
678 | INIT_KMALLOC_INFO(16, 16), | |
679 | INIT_KMALLOC_INFO(32, 32), | |
680 | INIT_KMALLOC_INFO(64, 64), | |
681 | INIT_KMALLOC_INFO(128, 128), | |
682 | INIT_KMALLOC_INFO(256, 256), | |
683 | INIT_KMALLOC_INFO(512, 512), | |
684 | INIT_KMALLOC_INFO(1024, 1k), | |
685 | INIT_KMALLOC_INFO(2048, 2k), | |
686 | INIT_KMALLOC_INFO(4096, 4k), | |
687 | INIT_KMALLOC_INFO(8192, 8k), | |
688 | INIT_KMALLOC_INFO(16384, 16k), | |
689 | INIT_KMALLOC_INFO(32768, 32k), | |
690 | INIT_KMALLOC_INFO(65536, 64k), | |
691 | INIT_KMALLOC_INFO(131072, 128k), | |
692 | INIT_KMALLOC_INFO(262144, 256k), | |
693 | INIT_KMALLOC_INFO(524288, 512k), | |
694 | INIT_KMALLOC_INFO(1048576, 1M), | |
695 | INIT_KMALLOC_INFO(2097152, 2M), | |
696 | INIT_KMALLOC_INFO(4194304, 4M), | |
697 | INIT_KMALLOC_INFO(8388608, 8M), | |
698 | INIT_KMALLOC_INFO(16777216, 16M), | |
699 | INIT_KMALLOC_INFO(33554432, 32M), | |
700 | INIT_KMALLOC_INFO(67108864, 64M) | |
4066c33d GG |
701 | }; |
702 | ||
f97d5f63 | 703 | /* |
34cc6990 DS |
704 | * Patch up the size_index table if we have strange large alignment |
705 | * requirements for the kmalloc array. This is only the case for | |
706 | * MIPS it seems. The standard arches will not generate any code here. | |
707 | * | |
708 | * Largest permitted alignment is 256 bytes due to the way we | |
709 | * handle the index determination for the smaller caches. | |
710 | * | |
711 | * Make sure that nothing crazy happens if someone starts tinkering | |
712 | * around with ARCH_KMALLOC_MINALIGN | |
f97d5f63 | 713 | */ |
34cc6990 | 714 | void __init setup_kmalloc_cache_index_table(void) |
f97d5f63 | 715 | { |
ac914d08 | 716 | unsigned int i; |
f97d5f63 | 717 | |
2c59dd65 CL |
718 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || |
719 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); | |
720 | ||
721 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { | |
ac914d08 | 722 | unsigned int elem = size_index_elem(i); |
2c59dd65 CL |
723 | |
724 | if (elem >= ARRAY_SIZE(size_index)) | |
725 | break; | |
726 | size_index[elem] = KMALLOC_SHIFT_LOW; | |
727 | } | |
728 | ||
729 | if (KMALLOC_MIN_SIZE >= 64) { | |
730 | /* | |
731 | * The 96 byte size cache is not used if the alignment | |
732 | * is 64 byte. | |
733 | */ | |
734 | for (i = 64 + 8; i <= 96; i += 8) | |
735 | size_index[size_index_elem(i)] = 7; | |
736 | ||
737 | } | |
738 | ||
739 | if (KMALLOC_MIN_SIZE >= 128) { | |
740 | /* | |
741 | * The 192 byte sized cache is not used if the alignment | |
742 | * is 128 byte. Redirect kmalloc to use the 256 byte cache | |
743 | * instead. | |
744 | */ | |
745 | for (i = 128 + 8; i <= 192; i += 8) | |
746 | size_index[size_index_elem(i)] = 8; | |
747 | } | |
34cc6990 DS |
748 | } |
749 | ||
1291523f | 750 | static void __init |
13657d0a | 751 | new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags) |
a9730fca | 752 | { |
cb5d9fb3 | 753 | if (type == KMALLOC_RECLAIM) |
1291523f | 754 | flags |= SLAB_RECLAIM_ACCOUNT; |
1291523f | 755 | |
cb5d9fb3 PL |
756 | kmalloc_caches[type][idx] = create_kmalloc_cache( |
757 | kmalloc_info[idx].name[type], | |
6c0c21ad DW |
758 | kmalloc_info[idx].size, flags, 0, |
759 | kmalloc_info[idx].size); | |
a9730fca CL |
760 | } |
761 | ||
34cc6990 DS |
762 | /* |
763 | * Create the kmalloc array. Some of the regular kmalloc arrays | |
764 | * may already have been created because they were needed to | |
765 | * enable allocations for slab creation. | |
766 | */ | |
d50112ed | 767 | void __init create_kmalloc_caches(slab_flags_t flags) |
34cc6990 | 768 | { |
13657d0a PL |
769 | int i; |
770 | enum kmalloc_cache_type type; | |
34cc6990 | 771 | |
1291523f VB |
772 | for (type = KMALLOC_NORMAL; type <= KMALLOC_RECLAIM; type++) { |
773 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { | |
774 | if (!kmalloc_caches[type][i]) | |
775 | new_kmalloc_cache(i, type, flags); | |
f97d5f63 | 776 | |
1291523f VB |
777 | /* |
778 | * Caches that are not of the two-to-the-power-of size. | |
779 | * These have to be created immediately after the | |
780 | * earlier power of two caches | |
781 | */ | |
782 | if (KMALLOC_MIN_SIZE <= 32 && i == 6 && | |
783 | !kmalloc_caches[type][1]) | |
784 | new_kmalloc_cache(1, type, flags); | |
785 | if (KMALLOC_MIN_SIZE <= 64 && i == 7 && | |
786 | !kmalloc_caches[type][2]) | |
787 | new_kmalloc_cache(2, type, flags); | |
788 | } | |
8a965b3b CL |
789 | } |
790 | ||
f97d5f63 CL |
791 | /* Kmalloc array is now usable */ |
792 | slab_state = UP; | |
793 | ||
f97d5f63 CL |
794 | #ifdef CONFIG_ZONE_DMA |
795 | for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { | |
cc252eae | 796 | struct kmem_cache *s = kmalloc_caches[KMALLOC_NORMAL][i]; |
f97d5f63 CL |
797 | |
798 | if (s) { | |
cc252eae | 799 | kmalloc_caches[KMALLOC_DMA][i] = create_kmalloc_cache( |
cb5d9fb3 | 800 | kmalloc_info[i].name[KMALLOC_DMA], |
dc0a7f75 | 801 | kmalloc_info[i].size, |
49f2d241 VB |
802 | SLAB_CACHE_DMA | flags, 0, |
803 | kmalloc_info[i].size); | |
f97d5f63 CL |
804 | } |
805 | } | |
806 | #endif | |
807 | } | |
45530c44 CL |
808 | #endif /* !CONFIG_SLOB */ |
809 | ||
44405099 LL |
810 | gfp_t kmalloc_fix_flags(gfp_t flags) |
811 | { | |
812 | gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; | |
813 | ||
814 | flags &= ~GFP_SLAB_BUG_MASK; | |
815 | pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", | |
816 | invalid_mask, &invalid_mask, flags, &flags); | |
817 | dump_stack(); | |
818 | ||
819 | return flags; | |
820 | } | |
821 | ||
cea371f4 VD |
822 | /* |
823 | * To avoid unnecessary overhead, we pass through large allocation requests | |
824 | * directly to the page allocator. We use __GFP_COMP, because we will need to | |
825 | * know the allocation order to free the pages properly in kfree. | |
826 | */ | |
52383431 VD |
827 | void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) |
828 | { | |
6a486c0a | 829 | void *ret = NULL; |
52383431 VD |
830 | struct page *page; |
831 | ||
44405099 LL |
832 | if (unlikely(flags & GFP_SLAB_BUG_MASK)) |
833 | flags = kmalloc_fix_flags(flags); | |
834 | ||
52383431 | 835 | flags |= __GFP_COMP; |
4949148a | 836 | page = alloc_pages(flags, order); |
6a486c0a VB |
837 | if (likely(page)) { |
838 | ret = page_address(page); | |
d42f3245 RG |
839 | mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE_B, |
840 | PAGE_SIZE << order); | |
6a486c0a | 841 | } |
0116523c | 842 | ret = kasan_kmalloc_large(ret, size, flags); |
a2f77575 | 843 | /* As ret might get tagged, call kmemleak hook after KASAN. */ |
53128245 | 844 | kmemleak_alloc(ret, size, 1, flags); |
52383431 VD |
845 | return ret; |
846 | } | |
847 | EXPORT_SYMBOL(kmalloc_order); | |
848 | ||
f1b6eb6e CL |
849 | #ifdef CONFIG_TRACING |
850 | void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) | |
851 | { | |
852 | void *ret = kmalloc_order(size, flags, order); | |
853 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags); | |
854 | return ret; | |
855 | } | |
856 | EXPORT_SYMBOL(kmalloc_order_trace); | |
857 | #endif | |
45530c44 | 858 | |
7c00fce9 TG |
859 | #ifdef CONFIG_SLAB_FREELIST_RANDOM |
860 | /* Randomize a generic freelist */ | |
861 | static void freelist_randomize(struct rnd_state *state, unsigned int *list, | |
302d55d5 | 862 | unsigned int count) |
7c00fce9 | 863 | { |
7c00fce9 | 864 | unsigned int rand; |
302d55d5 | 865 | unsigned int i; |
7c00fce9 TG |
866 | |
867 | for (i = 0; i < count; i++) | |
868 | list[i] = i; | |
869 | ||
870 | /* Fisher-Yates shuffle */ | |
871 | for (i = count - 1; i > 0; i--) { | |
872 | rand = prandom_u32_state(state); | |
873 | rand %= (i + 1); | |
874 | swap(list[i], list[rand]); | |
875 | } | |
876 | } | |
877 | ||
878 | /* Create a random sequence per cache */ | |
879 | int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, | |
880 | gfp_t gfp) | |
881 | { | |
882 | struct rnd_state state; | |
883 | ||
884 | if (count < 2 || cachep->random_seq) | |
885 | return 0; | |
886 | ||
887 | cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp); | |
888 | if (!cachep->random_seq) | |
889 | return -ENOMEM; | |
890 | ||
891 | /* Get best entropy at this stage of boot */ | |
892 | prandom_seed_state(&state, get_random_long()); | |
893 | ||
894 | freelist_randomize(&state, cachep->random_seq, count); | |
895 | return 0; | |
896 | } | |
897 | ||
898 | /* Destroy the per-cache random freelist sequence */ | |
899 | void cache_random_seq_destroy(struct kmem_cache *cachep) | |
900 | { | |
901 | kfree(cachep->random_seq); | |
902 | cachep->random_seq = NULL; | |
903 | } | |
904 | #endif /* CONFIG_SLAB_FREELIST_RANDOM */ | |
905 | ||
5b365771 | 906 | #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) |
e9b4db2b | 907 | #ifdef CONFIG_SLAB |
0825a6f9 | 908 | #define SLABINFO_RIGHTS (0600) |
e9b4db2b | 909 | #else |
0825a6f9 | 910 | #define SLABINFO_RIGHTS (0400) |
e9b4db2b WL |
911 | #endif |
912 | ||
b047501c | 913 | static void print_slabinfo_header(struct seq_file *m) |
bcee6e2a GC |
914 | { |
915 | /* | |
916 | * Output format version, so at least we can change it | |
917 | * without _too_ many complaints. | |
918 | */ | |
919 | #ifdef CONFIG_DEBUG_SLAB | |
920 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
921 | #else | |
922 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
923 | #endif | |
756a025f | 924 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); |
bcee6e2a GC |
925 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); |
926 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
927 | #ifdef CONFIG_DEBUG_SLAB | |
756a025f | 928 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); |
bcee6e2a GC |
929 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); |
930 | #endif | |
931 | seq_putc(m, '\n'); | |
932 | } | |
933 | ||
1df3b26f | 934 | void *slab_start(struct seq_file *m, loff_t *pos) |
b7454ad3 | 935 | { |
b7454ad3 | 936 | mutex_lock(&slab_mutex); |
c7094406 | 937 | return seq_list_start(&slab_caches, *pos); |
b7454ad3 GC |
938 | } |
939 | ||
276a2439 | 940 | void *slab_next(struct seq_file *m, void *p, loff_t *pos) |
b7454ad3 | 941 | { |
c7094406 | 942 | return seq_list_next(p, &slab_caches, pos); |
b7454ad3 GC |
943 | } |
944 | ||
276a2439 | 945 | void slab_stop(struct seq_file *m, void *p) |
b7454ad3 GC |
946 | { |
947 | mutex_unlock(&slab_mutex); | |
948 | } | |
949 | ||
b047501c | 950 | static void cache_show(struct kmem_cache *s, struct seq_file *m) |
b7454ad3 | 951 | { |
0d7561c6 GC |
952 | struct slabinfo sinfo; |
953 | ||
954 | memset(&sinfo, 0, sizeof(sinfo)); | |
955 | get_slabinfo(s, &sinfo); | |
956 | ||
957 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", | |
10befea9 | 958 | s->name, sinfo.active_objs, sinfo.num_objs, s->size, |
0d7561c6 GC |
959 | sinfo.objects_per_slab, (1 << sinfo.cache_order)); |
960 | ||
961 | seq_printf(m, " : tunables %4u %4u %4u", | |
962 | sinfo.limit, sinfo.batchcount, sinfo.shared); | |
963 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
964 | sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); | |
965 | slabinfo_show_stats(m, s); | |
966 | seq_putc(m, '\n'); | |
b7454ad3 GC |
967 | } |
968 | ||
1df3b26f | 969 | static int slab_show(struct seq_file *m, void *p) |
749c5415 | 970 | { |
c7094406 | 971 | struct kmem_cache *s = list_entry(p, struct kmem_cache, list); |
749c5415 | 972 | |
c7094406 | 973 | if (p == slab_caches.next) |
1df3b26f | 974 | print_slabinfo_header(m); |
10befea9 | 975 | cache_show(s, m); |
b047501c VD |
976 | return 0; |
977 | } | |
978 | ||
852d8be0 YS |
979 | void dump_unreclaimable_slab(void) |
980 | { | |
981 | struct kmem_cache *s, *s2; | |
982 | struct slabinfo sinfo; | |
983 | ||
984 | /* | |
985 | * Here acquiring slab_mutex is risky since we don't prefer to get | |
986 | * sleep in oom path. But, without mutex hold, it may introduce a | |
987 | * risk of crash. | |
988 | * Use mutex_trylock to protect the list traverse, dump nothing | |
989 | * without acquiring the mutex. | |
990 | */ | |
991 | if (!mutex_trylock(&slab_mutex)) { | |
992 | pr_warn("excessive unreclaimable slab but cannot dump stats\n"); | |
993 | return; | |
994 | } | |
995 | ||
996 | pr_info("Unreclaimable slab info:\n"); | |
997 | pr_info("Name Used Total\n"); | |
998 | ||
999 | list_for_each_entry_safe(s, s2, &slab_caches, list) { | |
10befea9 | 1000 | if (s->flags & SLAB_RECLAIM_ACCOUNT) |
852d8be0 YS |
1001 | continue; |
1002 | ||
1003 | get_slabinfo(s, &sinfo); | |
1004 | ||
1005 | if (sinfo.num_objs > 0) | |
10befea9 | 1006 | pr_info("%-17s %10luKB %10luKB\n", s->name, |
852d8be0 YS |
1007 | (sinfo.active_objs * s->size) / 1024, |
1008 | (sinfo.num_objs * s->size) / 1024); | |
1009 | } | |
1010 | mutex_unlock(&slab_mutex); | |
1011 | } | |
1012 | ||
a87425a3 | 1013 | #if defined(CONFIG_MEMCG_KMEM) |
b047501c VD |
1014 | int memcg_slab_show(struct seq_file *m, void *p) |
1015 | { | |
4330a26b RG |
1016 | /* |
1017 | * Deprecated. | |
1018 | * Please, take a look at tools/cgroup/slabinfo.py . | |
1019 | */ | |
b047501c | 1020 | return 0; |
749c5415 | 1021 | } |
b047501c | 1022 | #endif |
749c5415 | 1023 | |
b7454ad3 GC |
1024 | /* |
1025 | * slabinfo_op - iterator that generates /proc/slabinfo | |
1026 | * | |
1027 | * Output layout: | |
1028 | * cache-name | |
1029 | * num-active-objs | |
1030 | * total-objs | |
1031 | * object size | |
1032 | * num-active-slabs | |
1033 | * total-slabs | |
1034 | * num-pages-per-slab | |
1035 | * + further values on SMP and with statistics enabled | |
1036 | */ | |
1037 | static const struct seq_operations slabinfo_op = { | |
1df3b26f | 1038 | .start = slab_start, |
276a2439 WL |
1039 | .next = slab_next, |
1040 | .stop = slab_stop, | |
1df3b26f | 1041 | .show = slab_show, |
b7454ad3 GC |
1042 | }; |
1043 | ||
1044 | static int slabinfo_open(struct inode *inode, struct file *file) | |
1045 | { | |
1046 | return seq_open(file, &slabinfo_op); | |
1047 | } | |
1048 | ||
97a32539 | 1049 | static const struct proc_ops slabinfo_proc_ops = { |
d919b33d | 1050 | .proc_flags = PROC_ENTRY_PERMANENT, |
97a32539 AD |
1051 | .proc_open = slabinfo_open, |
1052 | .proc_read = seq_read, | |
1053 | .proc_write = slabinfo_write, | |
1054 | .proc_lseek = seq_lseek, | |
1055 | .proc_release = seq_release, | |
b7454ad3 GC |
1056 | }; |
1057 | ||
1058 | static int __init slab_proc_init(void) | |
1059 | { | |
97a32539 | 1060 | proc_create("slabinfo", SLABINFO_RIGHTS, NULL, &slabinfo_proc_ops); |
b7454ad3 GC |
1061 | return 0; |
1062 | } | |
1063 | module_init(slab_proc_init); | |
fcf8a1e4 | 1064 | |
5b365771 | 1065 | #endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */ |
928cec9c AR |
1066 | |
1067 | static __always_inline void *__do_krealloc(const void *p, size_t new_size, | |
1068 | gfp_t flags) | |
1069 | { | |
1070 | void *ret; | |
fa9ba3aa | 1071 | size_t ks; |
928cec9c | 1072 | |
fa9ba3aa | 1073 | ks = ksize(p); |
928cec9c | 1074 | |
0316bec2 | 1075 | if (ks >= new_size) { |
0116523c | 1076 | p = kasan_krealloc((void *)p, new_size, flags); |
928cec9c | 1077 | return (void *)p; |
0316bec2 | 1078 | } |
928cec9c AR |
1079 | |
1080 | ret = kmalloc_track_caller(new_size, flags); | |
1081 | if (ret && p) | |
1082 | memcpy(ret, p, ks); | |
1083 | ||
1084 | return ret; | |
1085 | } | |
1086 | ||
928cec9c AR |
1087 | /** |
1088 | * krealloc - reallocate memory. The contents will remain unchanged. | |
1089 | * @p: object to reallocate memory for. | |
1090 | * @new_size: how many bytes of memory are required. | |
1091 | * @flags: the type of memory to allocate. | |
1092 | * | |
1093 | * The contents of the object pointed to are preserved up to the | |
1094 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
1095 | * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a | |
1096 | * %NULL pointer, the object pointed to is freed. | |
a862f68a MR |
1097 | * |
1098 | * Return: pointer to the allocated memory or %NULL in case of error | |
928cec9c AR |
1099 | */ |
1100 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
1101 | { | |
1102 | void *ret; | |
1103 | ||
1104 | if (unlikely(!new_size)) { | |
1105 | kfree(p); | |
1106 | return ZERO_SIZE_PTR; | |
1107 | } | |
1108 | ||
1109 | ret = __do_krealloc(p, new_size, flags); | |
772a2fa5 | 1110 | if (ret && kasan_reset_tag(p) != kasan_reset_tag(ret)) |
928cec9c AR |
1111 | kfree(p); |
1112 | ||
1113 | return ret; | |
1114 | } | |
1115 | EXPORT_SYMBOL(krealloc); | |
1116 | ||
1117 | /** | |
453431a5 | 1118 | * kfree_sensitive - Clear sensitive information in memory before freeing |
928cec9c AR |
1119 | * @p: object to free memory of |
1120 | * | |
1121 | * The memory of the object @p points to is zeroed before freed. | |
453431a5 | 1122 | * If @p is %NULL, kfree_sensitive() does nothing. |
928cec9c AR |
1123 | * |
1124 | * Note: this function zeroes the whole allocated buffer which can be a good | |
1125 | * deal bigger than the requested buffer size passed to kmalloc(). So be | |
1126 | * careful when using this function in performance sensitive code. | |
1127 | */ | |
453431a5 | 1128 | void kfree_sensitive(const void *p) |
928cec9c AR |
1129 | { |
1130 | size_t ks; | |
1131 | void *mem = (void *)p; | |
1132 | ||
928cec9c | 1133 | ks = ksize(mem); |
fa9ba3aa WK |
1134 | if (ks) |
1135 | memzero_explicit(mem, ks); | |
928cec9c AR |
1136 | kfree(mem); |
1137 | } | |
453431a5 | 1138 | EXPORT_SYMBOL(kfree_sensitive); |
928cec9c | 1139 | |
10d1f8cb ME |
1140 | /** |
1141 | * ksize - get the actual amount of memory allocated for a given object | |
1142 | * @objp: Pointer to the object | |
1143 | * | |
1144 | * kmalloc may internally round up allocations and return more memory | |
1145 | * than requested. ksize() can be used to determine the actual amount of | |
1146 | * memory allocated. The caller may use this additional memory, even though | |
1147 | * a smaller amount of memory was initially specified with the kmalloc call. | |
1148 | * The caller must guarantee that objp points to a valid object previously | |
1149 | * allocated with either kmalloc() or kmem_cache_alloc(). The object | |
1150 | * must not be freed during the duration of the call. | |
1151 | * | |
1152 | * Return: size of the actual memory used by @objp in bytes | |
1153 | */ | |
1154 | size_t ksize(const void *objp) | |
1155 | { | |
0d4ca4c9 ME |
1156 | size_t size; |
1157 | ||
0d4ca4c9 ME |
1158 | /* |
1159 | * We need to check that the pointed to object is valid, and only then | |
1160 | * unpoison the shadow memory below. We use __kasan_check_read(), to | |
1161 | * generate a more useful report at the time ksize() is called (rather | |
1162 | * than later where behaviour is undefined due to potential | |
1163 | * use-after-free or double-free). | |
1164 | * | |
1165 | * If the pointed to memory is invalid we return 0, to avoid users of | |
1166 | * ksize() writing to and potentially corrupting the memory region. | |
1167 | * | |
1168 | * We want to perform the check before __ksize(), to avoid potentially | |
1169 | * crashing in __ksize() due to accessing invalid metadata. | |
1170 | */ | |
fa9ba3aa | 1171 | if (unlikely(ZERO_OR_NULL_PTR(objp)) || !__kasan_check_read(objp, 1)) |
0d4ca4c9 ME |
1172 | return 0; |
1173 | ||
1174 | size = __ksize(objp); | |
10d1f8cb ME |
1175 | /* |
1176 | * We assume that ksize callers could use whole allocated area, | |
1177 | * so we need to unpoison this area. | |
1178 | */ | |
1179 | kasan_unpoison_shadow(objp, size); | |
1180 | return size; | |
1181 | } | |
1182 | EXPORT_SYMBOL(ksize); | |
1183 | ||
928cec9c AR |
1184 | /* Tracepoints definitions. */ |
1185 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); | |
1186 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); | |
1187 | EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); | |
1188 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); | |
1189 | EXPORT_TRACEPOINT_SYMBOL(kfree); | |
1190 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); | |
4f6923fb HM |
1191 | |
1192 | int should_failslab(struct kmem_cache *s, gfp_t gfpflags) | |
1193 | { | |
1194 | if (__should_failslab(s, gfpflags)) | |
1195 | return -ENOMEM; | |
1196 | return 0; | |
1197 | } | |
1198 | ALLOW_ERROR_INJECTION(should_failslab, ERRNO); |