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Commit | Line | Data |
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039363f3 CL |
1 | /* |
2 | * Slab allocator functions that are independent of the allocator strategy | |
3 | * | |
4 | * (C) 2012 Christoph Lameter <cl@linux.com> | |
5 | */ | |
6 | #include <linux/slab.h> | |
7 | ||
8 | #include <linux/mm.h> | |
9 | #include <linux/poison.h> | |
10 | #include <linux/interrupt.h> | |
11 | #include <linux/memory.h> | |
12 | #include <linux/compiler.h> | |
13 | #include <linux/module.h> | |
20cea968 CL |
14 | #include <linux/cpu.h> |
15 | #include <linux/uaccess.h> | |
b7454ad3 GC |
16 | #include <linux/seq_file.h> |
17 | #include <linux/proc_fs.h> | |
039363f3 CL |
18 | #include <asm/cacheflush.h> |
19 | #include <asm/tlbflush.h> | |
20 | #include <asm/page.h> | |
2633d7a0 | 21 | #include <linux/memcontrol.h> |
928cec9c AR |
22 | |
23 | #define CREATE_TRACE_POINTS | |
f1b6eb6e | 24 | #include <trace/events/kmem.h> |
039363f3 | 25 | |
97d06609 CL |
26 | #include "slab.h" |
27 | ||
28 | enum slab_state slab_state; | |
18004c5d CL |
29 | LIST_HEAD(slab_caches); |
30 | DEFINE_MUTEX(slab_mutex); | |
9b030cb8 | 31 | struct kmem_cache *kmem_cache; |
97d06609 | 32 | |
423c929c JK |
33 | /* |
34 | * Set of flags that will prevent slab merging | |
35 | */ | |
36 | #define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
37 | SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ | |
38 | SLAB_FAILSLAB) | |
39 | ||
40 | #define SLAB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ | |
41 | SLAB_CACHE_DMA | SLAB_NOTRACK) | |
42 | ||
43 | /* | |
44 | * Merge control. If this is set then no merging of slab caches will occur. | |
45 | * (Could be removed. This was introduced to pacify the merge skeptics.) | |
46 | */ | |
47 | static int slab_nomerge; | |
48 | ||
49 | static int __init setup_slab_nomerge(char *str) | |
50 | { | |
51 | slab_nomerge = 1; | |
52 | return 1; | |
53 | } | |
54 | ||
55 | #ifdef CONFIG_SLUB | |
56 | __setup_param("slub_nomerge", slub_nomerge, setup_slab_nomerge, 0); | |
57 | #endif | |
58 | ||
59 | __setup("slab_nomerge", setup_slab_nomerge); | |
60 | ||
07f361b2 JK |
61 | /* |
62 | * Determine the size of a slab object | |
63 | */ | |
64 | unsigned int kmem_cache_size(struct kmem_cache *s) | |
65 | { | |
66 | return s->object_size; | |
67 | } | |
68 | EXPORT_SYMBOL(kmem_cache_size); | |
69 | ||
77be4b13 | 70 | #ifdef CONFIG_DEBUG_VM |
794b1248 | 71 | static int kmem_cache_sanity_check(const char *name, size_t size) |
039363f3 CL |
72 | { |
73 | struct kmem_cache *s = NULL; | |
74 | ||
039363f3 CL |
75 | if (!name || in_interrupt() || size < sizeof(void *) || |
76 | size > KMALLOC_MAX_SIZE) { | |
77be4b13 SK |
77 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); |
78 | return -EINVAL; | |
039363f3 | 79 | } |
b920536a | 80 | |
20cea968 CL |
81 | list_for_each_entry(s, &slab_caches, list) { |
82 | char tmp; | |
83 | int res; | |
84 | ||
85 | /* | |
86 | * This happens when the module gets unloaded and doesn't | |
87 | * destroy its slab cache and no-one else reuses the vmalloc | |
88 | * area of the module. Print a warning. | |
89 | */ | |
90 | res = probe_kernel_address(s->name, tmp); | |
91 | if (res) { | |
77be4b13 | 92 | pr_err("Slab cache with size %d has lost its name\n", |
20cea968 CL |
93 | s->object_size); |
94 | continue; | |
95 | } | |
20cea968 CL |
96 | } |
97 | ||
98 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ | |
77be4b13 SK |
99 | return 0; |
100 | } | |
101 | #else | |
794b1248 | 102 | static inline int kmem_cache_sanity_check(const char *name, size_t size) |
77be4b13 SK |
103 | { |
104 | return 0; | |
105 | } | |
20cea968 CL |
106 | #endif |
107 | ||
55007d84 | 108 | #ifdef CONFIG_MEMCG_KMEM |
f7ce3190 | 109 | void slab_init_memcg_params(struct kmem_cache *s) |
33a690c4 | 110 | { |
f7ce3190 VD |
111 | s->memcg_params.is_root_cache = true; |
112 | RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL); | |
113 | } | |
114 | ||
115 | static int init_memcg_params(struct kmem_cache *s, | |
116 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
117 | { | |
118 | struct memcg_cache_array *arr; | |
33a690c4 | 119 | |
f7ce3190 VD |
120 | if (memcg) { |
121 | s->memcg_params.is_root_cache = false; | |
122 | s->memcg_params.memcg = memcg; | |
123 | s->memcg_params.root_cache = root_cache; | |
33a690c4 | 124 | return 0; |
f7ce3190 | 125 | } |
33a690c4 | 126 | |
f7ce3190 | 127 | slab_init_memcg_params(s); |
33a690c4 | 128 | |
f7ce3190 VD |
129 | if (!memcg_nr_cache_ids) |
130 | return 0; | |
33a690c4 | 131 | |
f7ce3190 VD |
132 | arr = kzalloc(sizeof(struct memcg_cache_array) + |
133 | memcg_nr_cache_ids * sizeof(void *), | |
134 | GFP_KERNEL); | |
135 | if (!arr) | |
136 | return -ENOMEM; | |
33a690c4 | 137 | |
f7ce3190 | 138 | RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr); |
33a690c4 VD |
139 | return 0; |
140 | } | |
141 | ||
f7ce3190 | 142 | static void destroy_memcg_params(struct kmem_cache *s) |
33a690c4 | 143 | { |
f7ce3190 VD |
144 | if (is_root_cache(s)) |
145 | kfree(rcu_access_pointer(s->memcg_params.memcg_caches)); | |
33a690c4 VD |
146 | } |
147 | ||
f7ce3190 | 148 | static int update_memcg_params(struct kmem_cache *s, int new_array_size) |
6f817f4c | 149 | { |
f7ce3190 | 150 | struct memcg_cache_array *old, *new; |
6f817f4c | 151 | |
f7ce3190 VD |
152 | if (!is_root_cache(s)) |
153 | return 0; | |
6f817f4c | 154 | |
f7ce3190 VD |
155 | new = kzalloc(sizeof(struct memcg_cache_array) + |
156 | new_array_size * sizeof(void *), GFP_KERNEL); | |
157 | if (!new) | |
6f817f4c VD |
158 | return -ENOMEM; |
159 | ||
f7ce3190 VD |
160 | old = rcu_dereference_protected(s->memcg_params.memcg_caches, |
161 | lockdep_is_held(&slab_mutex)); | |
162 | if (old) | |
163 | memcpy(new->entries, old->entries, | |
164 | memcg_nr_cache_ids * sizeof(void *)); | |
6f817f4c | 165 | |
f7ce3190 VD |
166 | rcu_assign_pointer(s->memcg_params.memcg_caches, new); |
167 | if (old) | |
168 | kfree_rcu(old, rcu); | |
6f817f4c VD |
169 | return 0; |
170 | } | |
171 | ||
55007d84 GC |
172 | int memcg_update_all_caches(int num_memcgs) |
173 | { | |
174 | struct kmem_cache *s; | |
175 | int ret = 0; | |
55007d84 | 176 | |
05257a1a | 177 | mutex_lock(&slab_mutex); |
55007d84 | 178 | list_for_each_entry(s, &slab_caches, list) { |
f7ce3190 | 179 | ret = update_memcg_params(s, num_memcgs); |
55007d84 | 180 | /* |
55007d84 GC |
181 | * Instead of freeing the memory, we'll just leave the caches |
182 | * up to this point in an updated state. | |
183 | */ | |
184 | if (ret) | |
05257a1a | 185 | break; |
55007d84 | 186 | } |
55007d84 GC |
187 | mutex_unlock(&slab_mutex); |
188 | return ret; | |
189 | } | |
33a690c4 | 190 | #else |
f7ce3190 VD |
191 | static inline int init_memcg_params(struct kmem_cache *s, |
192 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
33a690c4 VD |
193 | { |
194 | return 0; | |
195 | } | |
196 | ||
f7ce3190 | 197 | static inline void destroy_memcg_params(struct kmem_cache *s) |
33a690c4 VD |
198 | { |
199 | } | |
200 | #endif /* CONFIG_MEMCG_KMEM */ | |
55007d84 | 201 | |
423c929c JK |
202 | /* |
203 | * Find a mergeable slab cache | |
204 | */ | |
205 | int slab_unmergeable(struct kmem_cache *s) | |
206 | { | |
207 | if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) | |
208 | return 1; | |
209 | ||
210 | if (!is_root_cache(s)) | |
211 | return 1; | |
212 | ||
213 | if (s->ctor) | |
214 | return 1; | |
215 | ||
216 | /* | |
217 | * We may have set a slab to be unmergeable during bootstrap. | |
218 | */ | |
219 | if (s->refcount < 0) | |
220 | return 1; | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
225 | struct kmem_cache *find_mergeable(size_t size, size_t align, | |
226 | unsigned long flags, const char *name, void (*ctor)(void *)) | |
227 | { | |
228 | struct kmem_cache *s; | |
229 | ||
230 | if (slab_nomerge || (flags & SLAB_NEVER_MERGE)) | |
231 | return NULL; | |
232 | ||
233 | if (ctor) | |
234 | return NULL; | |
235 | ||
236 | size = ALIGN(size, sizeof(void *)); | |
237 | align = calculate_alignment(flags, align, size); | |
238 | size = ALIGN(size, align); | |
239 | flags = kmem_cache_flags(size, flags, name, NULL); | |
240 | ||
54362057 | 241 | list_for_each_entry_reverse(s, &slab_caches, list) { |
423c929c JK |
242 | if (slab_unmergeable(s)) |
243 | continue; | |
244 | ||
245 | if (size > s->size) | |
246 | continue; | |
247 | ||
248 | if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) | |
249 | continue; | |
250 | /* | |
251 | * Check if alignment is compatible. | |
252 | * Courtesy of Adrian Drzewiecki | |
253 | */ | |
254 | if ((s->size & ~(align - 1)) != s->size) | |
255 | continue; | |
256 | ||
257 | if (s->size - size >= sizeof(void *)) | |
258 | continue; | |
259 | ||
95069ac8 JK |
260 | if (IS_ENABLED(CONFIG_SLAB) && align && |
261 | (align > s->align || s->align % align)) | |
262 | continue; | |
263 | ||
423c929c JK |
264 | return s; |
265 | } | |
266 | return NULL; | |
267 | } | |
268 | ||
45906855 CL |
269 | /* |
270 | * Figure out what the alignment of the objects will be given a set of | |
271 | * flags, a user specified alignment and the size of the objects. | |
272 | */ | |
273 | unsigned long calculate_alignment(unsigned long flags, | |
274 | unsigned long align, unsigned long size) | |
275 | { | |
276 | /* | |
277 | * If the user wants hardware cache aligned objects then follow that | |
278 | * suggestion if the object is sufficiently large. | |
279 | * | |
280 | * The hardware cache alignment cannot override the specified | |
281 | * alignment though. If that is greater then use it. | |
282 | */ | |
283 | if (flags & SLAB_HWCACHE_ALIGN) { | |
284 | unsigned long ralign = cache_line_size(); | |
285 | while (size <= ralign / 2) | |
286 | ralign /= 2; | |
287 | align = max(align, ralign); | |
288 | } | |
289 | ||
290 | if (align < ARCH_SLAB_MINALIGN) | |
291 | align = ARCH_SLAB_MINALIGN; | |
292 | ||
293 | return ALIGN(align, sizeof(void *)); | |
294 | } | |
295 | ||
794b1248 VD |
296 | static struct kmem_cache * |
297 | do_kmem_cache_create(char *name, size_t object_size, size_t size, size_t align, | |
298 | unsigned long flags, void (*ctor)(void *), | |
299 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
300 | { | |
301 | struct kmem_cache *s; | |
302 | int err; | |
303 | ||
304 | err = -ENOMEM; | |
305 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); | |
306 | if (!s) | |
307 | goto out; | |
308 | ||
309 | s->name = name; | |
310 | s->object_size = object_size; | |
311 | s->size = size; | |
312 | s->align = align; | |
313 | s->ctor = ctor; | |
314 | ||
f7ce3190 | 315 | err = init_memcg_params(s, memcg, root_cache); |
794b1248 VD |
316 | if (err) |
317 | goto out_free_cache; | |
318 | ||
319 | err = __kmem_cache_create(s, flags); | |
320 | if (err) | |
321 | goto out_free_cache; | |
322 | ||
323 | s->refcount = 1; | |
324 | list_add(&s->list, &slab_caches); | |
794b1248 VD |
325 | out: |
326 | if (err) | |
327 | return ERR_PTR(err); | |
328 | return s; | |
329 | ||
330 | out_free_cache: | |
f7ce3190 | 331 | destroy_memcg_params(s); |
7c4da061 | 332 | kmem_cache_free(kmem_cache, s); |
794b1248 VD |
333 | goto out; |
334 | } | |
45906855 | 335 | |
77be4b13 SK |
336 | /* |
337 | * kmem_cache_create - Create a cache. | |
338 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
339 | * @size: The size of objects to be created in this cache. | |
340 | * @align: The required alignment for the objects. | |
341 | * @flags: SLAB flags | |
342 | * @ctor: A constructor for the objects. | |
343 | * | |
344 | * Returns a ptr to the cache on success, NULL on failure. | |
345 | * Cannot be called within a interrupt, but can be interrupted. | |
346 | * The @ctor is run when new pages are allocated by the cache. | |
347 | * | |
348 | * The flags are | |
349 | * | |
350 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
351 | * to catch references to uninitialised memory. | |
352 | * | |
353 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
354 | * for buffer overruns. | |
355 | * | |
356 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
357 | * cacheline. This can be beneficial if you're counting cycles as closely | |
358 | * as davem. | |
359 | */ | |
2633d7a0 | 360 | struct kmem_cache * |
794b1248 VD |
361 | kmem_cache_create(const char *name, size_t size, size_t align, |
362 | unsigned long flags, void (*ctor)(void *)) | |
77be4b13 | 363 | { |
794b1248 VD |
364 | struct kmem_cache *s; |
365 | char *cache_name; | |
3965fc36 | 366 | int err; |
039363f3 | 367 | |
77be4b13 | 368 | get_online_cpus(); |
03afc0e2 | 369 | get_online_mems(); |
05257a1a | 370 | memcg_get_cache_ids(); |
03afc0e2 | 371 | |
77be4b13 | 372 | mutex_lock(&slab_mutex); |
686d550d | 373 | |
794b1248 | 374 | err = kmem_cache_sanity_check(name, size); |
3aa24f51 AM |
375 | if (err) { |
376 | s = NULL; /* suppress uninit var warning */ | |
3965fc36 | 377 | goto out_unlock; |
3aa24f51 | 378 | } |
686d550d | 379 | |
d8843922 GC |
380 | /* |
381 | * Some allocators will constraint the set of valid flags to a subset | |
382 | * of all flags. We expect them to define CACHE_CREATE_MASK in this | |
383 | * case, and we'll just provide them with a sanitized version of the | |
384 | * passed flags. | |
385 | */ | |
386 | flags &= CACHE_CREATE_MASK; | |
686d550d | 387 | |
794b1248 VD |
388 | s = __kmem_cache_alias(name, size, align, flags, ctor); |
389 | if (s) | |
3965fc36 | 390 | goto out_unlock; |
2633d7a0 | 391 | |
794b1248 VD |
392 | cache_name = kstrdup(name, GFP_KERNEL); |
393 | if (!cache_name) { | |
394 | err = -ENOMEM; | |
395 | goto out_unlock; | |
396 | } | |
7c9adf5a | 397 | |
794b1248 VD |
398 | s = do_kmem_cache_create(cache_name, size, size, |
399 | calculate_alignment(flags, align, size), | |
400 | flags, ctor, NULL, NULL); | |
401 | if (IS_ERR(s)) { | |
402 | err = PTR_ERR(s); | |
403 | kfree(cache_name); | |
404 | } | |
3965fc36 VD |
405 | |
406 | out_unlock: | |
20cea968 | 407 | mutex_unlock(&slab_mutex); |
03afc0e2 | 408 | |
05257a1a | 409 | memcg_put_cache_ids(); |
03afc0e2 | 410 | put_online_mems(); |
20cea968 CL |
411 | put_online_cpus(); |
412 | ||
ba3253c7 | 413 | if (err) { |
686d550d CL |
414 | if (flags & SLAB_PANIC) |
415 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
416 | name, err); | |
417 | else { | |
418 | printk(KERN_WARNING "kmem_cache_create(%s) failed with error %d", | |
419 | name, err); | |
420 | dump_stack(); | |
421 | } | |
686d550d CL |
422 | return NULL; |
423 | } | |
039363f3 CL |
424 | return s; |
425 | } | |
794b1248 | 426 | EXPORT_SYMBOL(kmem_cache_create); |
2633d7a0 | 427 | |
d5b3cf71 VD |
428 | static int do_kmem_cache_shutdown(struct kmem_cache *s, |
429 | struct list_head *release, bool *need_rcu_barrier) | |
430 | { | |
431 | if (__kmem_cache_shutdown(s) != 0) { | |
432 | printk(KERN_ERR "kmem_cache_destroy %s: " | |
433 | "Slab cache still has objects\n", s->name); | |
434 | dump_stack(); | |
435 | return -EBUSY; | |
436 | } | |
437 | ||
438 | if (s->flags & SLAB_DESTROY_BY_RCU) | |
439 | *need_rcu_barrier = true; | |
440 | ||
441 | #ifdef CONFIG_MEMCG_KMEM | |
442 | if (!is_root_cache(s)) { | |
f7ce3190 VD |
443 | int idx; |
444 | struct memcg_cache_array *arr; | |
445 | ||
446 | idx = memcg_cache_id(s->memcg_params.memcg); | |
447 | arr = rcu_dereference_protected(s->memcg_params.root_cache-> | |
448 | memcg_params.memcg_caches, | |
449 | lockdep_is_held(&slab_mutex)); | |
450 | BUG_ON(arr->entries[idx] != s); | |
451 | arr->entries[idx] = NULL; | |
d5b3cf71 VD |
452 | } |
453 | #endif | |
454 | list_move(&s->list, release); | |
455 | return 0; | |
456 | } | |
457 | ||
458 | static void do_kmem_cache_release(struct list_head *release, | |
459 | bool need_rcu_barrier) | |
460 | { | |
461 | struct kmem_cache *s, *s2; | |
462 | ||
463 | if (need_rcu_barrier) | |
464 | rcu_barrier(); | |
465 | ||
466 | list_for_each_entry_safe(s, s2, release, list) { | |
467 | #ifdef SLAB_SUPPORTS_SYSFS | |
468 | sysfs_slab_remove(s); | |
469 | #else | |
470 | slab_kmem_cache_release(s); | |
471 | #endif | |
472 | } | |
473 | } | |
474 | ||
794b1248 VD |
475 | #ifdef CONFIG_MEMCG_KMEM |
476 | /* | |
776ed0f0 | 477 | * memcg_create_kmem_cache - Create a cache for a memory cgroup. |
794b1248 VD |
478 | * @memcg: The memory cgroup the new cache is for. |
479 | * @root_cache: The parent of the new cache. | |
480 | * | |
481 | * This function attempts to create a kmem cache that will serve allocation | |
482 | * requests going from @memcg to @root_cache. The new cache inherits properties | |
483 | * from its parent. | |
484 | */ | |
d5b3cf71 VD |
485 | void memcg_create_kmem_cache(struct mem_cgroup *memcg, |
486 | struct kmem_cache *root_cache) | |
2633d7a0 | 487 | { |
3e0350a3 | 488 | static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */ |
f7ce3190 | 489 | struct memcg_cache_array *arr; |
bd673145 | 490 | struct kmem_cache *s = NULL; |
794b1248 | 491 | char *cache_name; |
f7ce3190 | 492 | int idx; |
794b1248 VD |
493 | |
494 | get_online_cpus(); | |
03afc0e2 VD |
495 | get_online_mems(); |
496 | ||
794b1248 VD |
497 | mutex_lock(&slab_mutex); |
498 | ||
f7ce3190 VD |
499 | idx = memcg_cache_id(memcg); |
500 | arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches, | |
501 | lockdep_is_held(&slab_mutex)); | |
502 | ||
d5b3cf71 VD |
503 | /* |
504 | * Since per-memcg caches are created asynchronously on first | |
505 | * allocation (see memcg_kmem_get_cache()), several threads can try to | |
506 | * create the same cache, but only one of them may succeed. | |
507 | */ | |
f7ce3190 | 508 | if (arr->entries[idx]) |
d5b3cf71 VD |
509 | goto out_unlock; |
510 | ||
3e0350a3 VD |
511 | cgroup_name(mem_cgroup_css(memcg)->cgroup, |
512 | memcg_name_buf, sizeof(memcg_name_buf)); | |
073ee1c6 | 513 | cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name, |
f7ce3190 | 514 | idx, memcg_name_buf); |
794b1248 VD |
515 | if (!cache_name) |
516 | goto out_unlock; | |
517 | ||
518 | s = do_kmem_cache_create(cache_name, root_cache->object_size, | |
519 | root_cache->size, root_cache->align, | |
520 | root_cache->flags, root_cache->ctor, | |
521 | memcg, root_cache); | |
d5b3cf71 VD |
522 | /* |
523 | * If we could not create a memcg cache, do not complain, because | |
524 | * that's not critical at all as we can always proceed with the root | |
525 | * cache. | |
526 | */ | |
bd673145 | 527 | if (IS_ERR(s)) { |
794b1248 | 528 | kfree(cache_name); |
d5b3cf71 | 529 | goto out_unlock; |
bd673145 | 530 | } |
794b1248 | 531 | |
d5b3cf71 VD |
532 | /* |
533 | * Since readers won't lock (see cache_from_memcg_idx()), we need a | |
534 | * barrier here to ensure nobody will see the kmem_cache partially | |
535 | * initialized. | |
536 | */ | |
537 | smp_wmb(); | |
f7ce3190 | 538 | arr->entries[idx] = s; |
d5b3cf71 | 539 | |
794b1248 VD |
540 | out_unlock: |
541 | mutex_unlock(&slab_mutex); | |
03afc0e2 VD |
542 | |
543 | put_online_mems(); | |
794b1248 | 544 | put_online_cpus(); |
2633d7a0 | 545 | } |
b8529907 | 546 | |
d5b3cf71 | 547 | void memcg_destroy_kmem_caches(struct mem_cgroup *memcg) |
b8529907 | 548 | { |
d5b3cf71 VD |
549 | LIST_HEAD(release); |
550 | bool need_rcu_barrier = false; | |
551 | struct kmem_cache *s, *s2; | |
b8529907 | 552 | |
d5b3cf71 VD |
553 | get_online_cpus(); |
554 | get_online_mems(); | |
b8529907 | 555 | |
b8529907 | 556 | mutex_lock(&slab_mutex); |
d5b3cf71 | 557 | list_for_each_entry_safe(s, s2, &slab_caches, list) { |
f7ce3190 | 558 | if (is_root_cache(s) || s->memcg_params.memcg != memcg) |
d5b3cf71 VD |
559 | continue; |
560 | /* | |
561 | * The cgroup is about to be freed and therefore has no charges | |
562 | * left. Hence, all its caches must be empty by now. | |
563 | */ | |
564 | BUG_ON(do_kmem_cache_shutdown(s, &release, &need_rcu_barrier)); | |
565 | } | |
566 | mutex_unlock(&slab_mutex); | |
b8529907 | 567 | |
d5b3cf71 VD |
568 | put_online_mems(); |
569 | put_online_cpus(); | |
570 | ||
571 | do_kmem_cache_release(&release, need_rcu_barrier); | |
b8529907 | 572 | } |
794b1248 | 573 | #endif /* CONFIG_MEMCG_KMEM */ |
97d06609 | 574 | |
41a21285 CL |
575 | void slab_kmem_cache_release(struct kmem_cache *s) |
576 | { | |
f7ce3190 | 577 | destroy_memcg_params(s); |
41a21285 CL |
578 | kfree(s->name); |
579 | kmem_cache_free(kmem_cache, s); | |
580 | } | |
581 | ||
945cf2b6 CL |
582 | void kmem_cache_destroy(struct kmem_cache *s) |
583 | { | |
d5b3cf71 VD |
584 | int i; |
585 | LIST_HEAD(release); | |
586 | bool need_rcu_barrier = false; | |
587 | bool busy = false; | |
588 | ||
945cf2b6 | 589 | get_online_cpus(); |
03afc0e2 VD |
590 | get_online_mems(); |
591 | ||
945cf2b6 | 592 | mutex_lock(&slab_mutex); |
b8529907 | 593 | |
945cf2b6 | 594 | s->refcount--; |
b8529907 VD |
595 | if (s->refcount) |
596 | goto out_unlock; | |
597 | ||
d5b3cf71 VD |
598 | for_each_memcg_cache_index(i) { |
599 | struct kmem_cache *c = cache_from_memcg_idx(s, i); | |
b8529907 | 600 | |
d5b3cf71 VD |
601 | if (c && do_kmem_cache_shutdown(c, &release, &need_rcu_barrier)) |
602 | busy = true; | |
945cf2b6 | 603 | } |
b8529907 | 604 | |
d5b3cf71 VD |
605 | if (!busy) |
606 | do_kmem_cache_shutdown(s, &release, &need_rcu_barrier); | |
b8529907 VD |
607 | |
608 | out_unlock: | |
609 | mutex_unlock(&slab_mutex); | |
d5b3cf71 | 610 | |
03afc0e2 | 611 | put_online_mems(); |
945cf2b6 | 612 | put_online_cpus(); |
d5b3cf71 VD |
613 | |
614 | do_kmem_cache_release(&release, need_rcu_barrier); | |
945cf2b6 CL |
615 | } |
616 | EXPORT_SYMBOL(kmem_cache_destroy); | |
617 | ||
03afc0e2 VD |
618 | /** |
619 | * kmem_cache_shrink - Shrink a cache. | |
620 | * @cachep: The cache to shrink. | |
621 | * | |
622 | * Releases as many slabs as possible for a cache. | |
623 | * To help debugging, a zero exit status indicates all slabs were released. | |
624 | */ | |
625 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
626 | { | |
627 | int ret; | |
628 | ||
629 | get_online_cpus(); | |
630 | get_online_mems(); | |
631 | ret = __kmem_cache_shrink(cachep); | |
632 | put_online_mems(); | |
633 | put_online_cpus(); | |
634 | return ret; | |
635 | } | |
636 | EXPORT_SYMBOL(kmem_cache_shrink); | |
637 | ||
97d06609 CL |
638 | int slab_is_available(void) |
639 | { | |
640 | return slab_state >= UP; | |
641 | } | |
b7454ad3 | 642 | |
45530c44 CL |
643 | #ifndef CONFIG_SLOB |
644 | /* Create a cache during boot when no slab services are available yet */ | |
645 | void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size, | |
646 | unsigned long flags) | |
647 | { | |
648 | int err; | |
649 | ||
650 | s->name = name; | |
651 | s->size = s->object_size = size; | |
45906855 | 652 | s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size); |
f7ce3190 VD |
653 | |
654 | slab_init_memcg_params(s); | |
655 | ||
45530c44 CL |
656 | err = __kmem_cache_create(s, flags); |
657 | ||
658 | if (err) | |
31ba7346 | 659 | panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n", |
45530c44 CL |
660 | name, size, err); |
661 | ||
662 | s->refcount = -1; /* Exempt from merging for now */ | |
663 | } | |
664 | ||
665 | struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size, | |
666 | unsigned long flags) | |
667 | { | |
668 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); | |
669 | ||
670 | if (!s) | |
671 | panic("Out of memory when creating slab %s\n", name); | |
672 | ||
673 | create_boot_cache(s, name, size, flags); | |
674 | list_add(&s->list, &slab_caches); | |
675 | s->refcount = 1; | |
676 | return s; | |
677 | } | |
678 | ||
9425c58e CL |
679 | struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1]; |
680 | EXPORT_SYMBOL(kmalloc_caches); | |
681 | ||
682 | #ifdef CONFIG_ZONE_DMA | |
683 | struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1]; | |
684 | EXPORT_SYMBOL(kmalloc_dma_caches); | |
685 | #endif | |
686 | ||
2c59dd65 CL |
687 | /* |
688 | * Conversion table for small slabs sizes / 8 to the index in the | |
689 | * kmalloc array. This is necessary for slabs < 192 since we have non power | |
690 | * of two cache sizes there. The size of larger slabs can be determined using | |
691 | * fls. | |
692 | */ | |
693 | static s8 size_index[24] = { | |
694 | 3, /* 8 */ | |
695 | 4, /* 16 */ | |
696 | 5, /* 24 */ | |
697 | 5, /* 32 */ | |
698 | 6, /* 40 */ | |
699 | 6, /* 48 */ | |
700 | 6, /* 56 */ | |
701 | 6, /* 64 */ | |
702 | 1, /* 72 */ | |
703 | 1, /* 80 */ | |
704 | 1, /* 88 */ | |
705 | 1, /* 96 */ | |
706 | 7, /* 104 */ | |
707 | 7, /* 112 */ | |
708 | 7, /* 120 */ | |
709 | 7, /* 128 */ | |
710 | 2, /* 136 */ | |
711 | 2, /* 144 */ | |
712 | 2, /* 152 */ | |
713 | 2, /* 160 */ | |
714 | 2, /* 168 */ | |
715 | 2, /* 176 */ | |
716 | 2, /* 184 */ | |
717 | 2 /* 192 */ | |
718 | }; | |
719 | ||
720 | static inline int size_index_elem(size_t bytes) | |
721 | { | |
722 | return (bytes - 1) / 8; | |
723 | } | |
724 | ||
725 | /* | |
726 | * Find the kmem_cache structure that serves a given size of | |
727 | * allocation | |
728 | */ | |
729 | struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) | |
730 | { | |
731 | int index; | |
732 | ||
9de1bc87 | 733 | if (unlikely(size > KMALLOC_MAX_SIZE)) { |
907985f4 | 734 | WARN_ON_ONCE(!(flags & __GFP_NOWARN)); |
6286ae97 | 735 | return NULL; |
907985f4 | 736 | } |
6286ae97 | 737 | |
2c59dd65 CL |
738 | if (size <= 192) { |
739 | if (!size) | |
740 | return ZERO_SIZE_PTR; | |
741 | ||
742 | index = size_index[size_index_elem(size)]; | |
743 | } else | |
744 | index = fls(size - 1); | |
745 | ||
746 | #ifdef CONFIG_ZONE_DMA | |
b1e05416 | 747 | if (unlikely((flags & GFP_DMA))) |
2c59dd65 CL |
748 | return kmalloc_dma_caches[index]; |
749 | ||
750 | #endif | |
751 | return kmalloc_caches[index]; | |
752 | } | |
753 | ||
f97d5f63 CL |
754 | /* |
755 | * Create the kmalloc array. Some of the regular kmalloc arrays | |
756 | * may already have been created because they were needed to | |
757 | * enable allocations for slab creation. | |
758 | */ | |
759 | void __init create_kmalloc_caches(unsigned long flags) | |
760 | { | |
761 | int i; | |
762 | ||
2c59dd65 CL |
763 | /* |
764 | * Patch up the size_index table if we have strange large alignment | |
765 | * requirements for the kmalloc array. This is only the case for | |
766 | * MIPS it seems. The standard arches will not generate any code here. | |
767 | * | |
768 | * Largest permitted alignment is 256 bytes due to the way we | |
769 | * handle the index determination for the smaller caches. | |
770 | * | |
771 | * Make sure that nothing crazy happens if someone starts tinkering | |
772 | * around with ARCH_KMALLOC_MINALIGN | |
773 | */ | |
774 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || | |
775 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); | |
776 | ||
777 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { | |
778 | int elem = size_index_elem(i); | |
779 | ||
780 | if (elem >= ARRAY_SIZE(size_index)) | |
781 | break; | |
782 | size_index[elem] = KMALLOC_SHIFT_LOW; | |
783 | } | |
784 | ||
785 | if (KMALLOC_MIN_SIZE >= 64) { | |
786 | /* | |
787 | * The 96 byte size cache is not used if the alignment | |
788 | * is 64 byte. | |
789 | */ | |
790 | for (i = 64 + 8; i <= 96; i += 8) | |
791 | size_index[size_index_elem(i)] = 7; | |
792 | ||
793 | } | |
794 | ||
795 | if (KMALLOC_MIN_SIZE >= 128) { | |
796 | /* | |
797 | * The 192 byte sized cache is not used if the alignment | |
798 | * is 128 byte. Redirect kmalloc to use the 256 byte cache | |
799 | * instead. | |
800 | */ | |
801 | for (i = 128 + 8; i <= 192; i += 8) | |
802 | size_index[size_index_elem(i)] = 8; | |
803 | } | |
8a965b3b CL |
804 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { |
805 | if (!kmalloc_caches[i]) { | |
f97d5f63 CL |
806 | kmalloc_caches[i] = create_kmalloc_cache(NULL, |
807 | 1 << i, flags); | |
956e46ef | 808 | } |
f97d5f63 | 809 | |
956e46ef CM |
810 | /* |
811 | * Caches that are not of the two-to-the-power-of size. | |
812 | * These have to be created immediately after the | |
813 | * earlier power of two caches | |
814 | */ | |
815 | if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6) | |
816 | kmalloc_caches[1] = create_kmalloc_cache(NULL, 96, flags); | |
8a965b3b | 817 | |
956e46ef CM |
818 | if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7) |
819 | kmalloc_caches[2] = create_kmalloc_cache(NULL, 192, flags); | |
8a965b3b CL |
820 | } |
821 | ||
f97d5f63 CL |
822 | /* Kmalloc array is now usable */ |
823 | slab_state = UP; | |
824 | ||
825 | for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { | |
826 | struct kmem_cache *s = kmalloc_caches[i]; | |
827 | char *n; | |
828 | ||
829 | if (s) { | |
830 | n = kasprintf(GFP_NOWAIT, "kmalloc-%d", kmalloc_size(i)); | |
831 | ||
832 | BUG_ON(!n); | |
833 | s->name = n; | |
834 | } | |
835 | } | |
836 | ||
837 | #ifdef CONFIG_ZONE_DMA | |
838 | for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { | |
839 | struct kmem_cache *s = kmalloc_caches[i]; | |
840 | ||
841 | if (s) { | |
842 | int size = kmalloc_size(i); | |
843 | char *n = kasprintf(GFP_NOWAIT, | |
844 | "dma-kmalloc-%d", size); | |
845 | ||
846 | BUG_ON(!n); | |
847 | kmalloc_dma_caches[i] = create_kmalloc_cache(n, | |
848 | size, SLAB_CACHE_DMA | flags); | |
849 | } | |
850 | } | |
851 | #endif | |
852 | } | |
45530c44 CL |
853 | #endif /* !CONFIG_SLOB */ |
854 | ||
cea371f4 VD |
855 | /* |
856 | * To avoid unnecessary overhead, we pass through large allocation requests | |
857 | * directly to the page allocator. We use __GFP_COMP, because we will need to | |
858 | * know the allocation order to free the pages properly in kfree. | |
859 | */ | |
52383431 VD |
860 | void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) |
861 | { | |
862 | void *ret; | |
863 | struct page *page; | |
864 | ||
865 | flags |= __GFP_COMP; | |
866 | page = alloc_kmem_pages(flags, order); | |
867 | ret = page ? page_address(page) : NULL; | |
868 | kmemleak_alloc(ret, size, 1, flags); | |
869 | return ret; | |
870 | } | |
871 | EXPORT_SYMBOL(kmalloc_order); | |
872 | ||
f1b6eb6e CL |
873 | #ifdef CONFIG_TRACING |
874 | void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) | |
875 | { | |
876 | void *ret = kmalloc_order(size, flags, order); | |
877 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags); | |
878 | return ret; | |
879 | } | |
880 | EXPORT_SYMBOL(kmalloc_order_trace); | |
881 | #endif | |
45530c44 | 882 | |
b7454ad3 | 883 | #ifdef CONFIG_SLABINFO |
e9b4db2b WL |
884 | |
885 | #ifdef CONFIG_SLAB | |
886 | #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR) | |
887 | #else | |
888 | #define SLABINFO_RIGHTS S_IRUSR | |
889 | #endif | |
890 | ||
b047501c | 891 | static void print_slabinfo_header(struct seq_file *m) |
bcee6e2a GC |
892 | { |
893 | /* | |
894 | * Output format version, so at least we can change it | |
895 | * without _too_ many complaints. | |
896 | */ | |
897 | #ifdef CONFIG_DEBUG_SLAB | |
898 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
899 | #else | |
900 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
901 | #endif | |
902 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> " | |
903 | "<objperslab> <pagesperslab>"); | |
904 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); | |
905 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
906 | #ifdef CONFIG_DEBUG_SLAB | |
907 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> " | |
908 | "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); | |
909 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); | |
910 | #endif | |
911 | seq_putc(m, '\n'); | |
912 | } | |
913 | ||
1df3b26f | 914 | void *slab_start(struct seq_file *m, loff_t *pos) |
b7454ad3 | 915 | { |
b7454ad3 | 916 | mutex_lock(&slab_mutex); |
b7454ad3 GC |
917 | return seq_list_start(&slab_caches, *pos); |
918 | } | |
919 | ||
276a2439 | 920 | void *slab_next(struct seq_file *m, void *p, loff_t *pos) |
b7454ad3 GC |
921 | { |
922 | return seq_list_next(p, &slab_caches, pos); | |
923 | } | |
924 | ||
276a2439 | 925 | void slab_stop(struct seq_file *m, void *p) |
b7454ad3 GC |
926 | { |
927 | mutex_unlock(&slab_mutex); | |
928 | } | |
929 | ||
749c5415 GC |
930 | static void |
931 | memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info) | |
932 | { | |
933 | struct kmem_cache *c; | |
934 | struct slabinfo sinfo; | |
935 | int i; | |
936 | ||
937 | if (!is_root_cache(s)) | |
938 | return; | |
939 | ||
940 | for_each_memcg_cache_index(i) { | |
2ade4de8 | 941 | c = cache_from_memcg_idx(s, i); |
749c5415 GC |
942 | if (!c) |
943 | continue; | |
944 | ||
945 | memset(&sinfo, 0, sizeof(sinfo)); | |
946 | get_slabinfo(c, &sinfo); | |
947 | ||
948 | info->active_slabs += sinfo.active_slabs; | |
949 | info->num_slabs += sinfo.num_slabs; | |
950 | info->shared_avail += sinfo.shared_avail; | |
951 | info->active_objs += sinfo.active_objs; | |
952 | info->num_objs += sinfo.num_objs; | |
953 | } | |
954 | } | |
955 | ||
b047501c | 956 | static void cache_show(struct kmem_cache *s, struct seq_file *m) |
b7454ad3 | 957 | { |
0d7561c6 GC |
958 | struct slabinfo sinfo; |
959 | ||
960 | memset(&sinfo, 0, sizeof(sinfo)); | |
961 | get_slabinfo(s, &sinfo); | |
962 | ||
749c5415 GC |
963 | memcg_accumulate_slabinfo(s, &sinfo); |
964 | ||
0d7561c6 | 965 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", |
749c5415 | 966 | cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, |
0d7561c6 GC |
967 | sinfo.objects_per_slab, (1 << sinfo.cache_order)); |
968 | ||
969 | seq_printf(m, " : tunables %4u %4u %4u", | |
970 | sinfo.limit, sinfo.batchcount, sinfo.shared); | |
971 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
972 | sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); | |
973 | slabinfo_show_stats(m, s); | |
974 | seq_putc(m, '\n'); | |
b7454ad3 GC |
975 | } |
976 | ||
1df3b26f | 977 | static int slab_show(struct seq_file *m, void *p) |
749c5415 GC |
978 | { |
979 | struct kmem_cache *s = list_entry(p, struct kmem_cache, list); | |
980 | ||
1df3b26f VD |
981 | if (p == slab_caches.next) |
982 | print_slabinfo_header(m); | |
b047501c VD |
983 | if (is_root_cache(s)) |
984 | cache_show(s, m); | |
985 | return 0; | |
986 | } | |
987 | ||
988 | #ifdef CONFIG_MEMCG_KMEM | |
989 | int memcg_slab_show(struct seq_file *m, void *p) | |
990 | { | |
991 | struct kmem_cache *s = list_entry(p, struct kmem_cache, list); | |
992 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
993 | ||
994 | if (p == slab_caches.next) | |
995 | print_slabinfo_header(m); | |
f7ce3190 | 996 | if (!is_root_cache(s) && s->memcg_params.memcg == memcg) |
b047501c VD |
997 | cache_show(s, m); |
998 | return 0; | |
749c5415 | 999 | } |
b047501c | 1000 | #endif |
749c5415 | 1001 | |
b7454ad3 GC |
1002 | /* |
1003 | * slabinfo_op - iterator that generates /proc/slabinfo | |
1004 | * | |
1005 | * Output layout: | |
1006 | * cache-name | |
1007 | * num-active-objs | |
1008 | * total-objs | |
1009 | * object size | |
1010 | * num-active-slabs | |
1011 | * total-slabs | |
1012 | * num-pages-per-slab | |
1013 | * + further values on SMP and with statistics enabled | |
1014 | */ | |
1015 | static const struct seq_operations slabinfo_op = { | |
1df3b26f | 1016 | .start = slab_start, |
276a2439 WL |
1017 | .next = slab_next, |
1018 | .stop = slab_stop, | |
1df3b26f | 1019 | .show = slab_show, |
b7454ad3 GC |
1020 | }; |
1021 | ||
1022 | static int slabinfo_open(struct inode *inode, struct file *file) | |
1023 | { | |
1024 | return seq_open(file, &slabinfo_op); | |
1025 | } | |
1026 | ||
1027 | static const struct file_operations proc_slabinfo_operations = { | |
1028 | .open = slabinfo_open, | |
1029 | .read = seq_read, | |
1030 | .write = slabinfo_write, | |
1031 | .llseek = seq_lseek, | |
1032 | .release = seq_release, | |
1033 | }; | |
1034 | ||
1035 | static int __init slab_proc_init(void) | |
1036 | { | |
e9b4db2b WL |
1037 | proc_create("slabinfo", SLABINFO_RIGHTS, NULL, |
1038 | &proc_slabinfo_operations); | |
b7454ad3 GC |
1039 | return 0; |
1040 | } | |
1041 | module_init(slab_proc_init); | |
1042 | #endif /* CONFIG_SLABINFO */ | |
928cec9c AR |
1043 | |
1044 | static __always_inline void *__do_krealloc(const void *p, size_t new_size, | |
1045 | gfp_t flags) | |
1046 | { | |
1047 | void *ret; | |
1048 | size_t ks = 0; | |
1049 | ||
1050 | if (p) | |
1051 | ks = ksize(p); | |
1052 | ||
1053 | if (ks >= new_size) | |
1054 | return (void *)p; | |
1055 | ||
1056 | ret = kmalloc_track_caller(new_size, flags); | |
1057 | if (ret && p) | |
1058 | memcpy(ret, p, ks); | |
1059 | ||
1060 | return ret; | |
1061 | } | |
1062 | ||
1063 | /** | |
1064 | * __krealloc - like krealloc() but don't free @p. | |
1065 | * @p: object to reallocate memory for. | |
1066 | * @new_size: how many bytes of memory are required. | |
1067 | * @flags: the type of memory to allocate. | |
1068 | * | |
1069 | * This function is like krealloc() except it never frees the originally | |
1070 | * allocated buffer. Use this if you don't want to free the buffer immediately | |
1071 | * like, for example, with RCU. | |
1072 | */ | |
1073 | void *__krealloc(const void *p, size_t new_size, gfp_t flags) | |
1074 | { | |
1075 | if (unlikely(!new_size)) | |
1076 | return ZERO_SIZE_PTR; | |
1077 | ||
1078 | return __do_krealloc(p, new_size, flags); | |
1079 | ||
1080 | } | |
1081 | EXPORT_SYMBOL(__krealloc); | |
1082 | ||
1083 | /** | |
1084 | * krealloc - reallocate memory. The contents will remain unchanged. | |
1085 | * @p: object to reallocate memory for. | |
1086 | * @new_size: how many bytes of memory are required. | |
1087 | * @flags: the type of memory to allocate. | |
1088 | * | |
1089 | * The contents of the object pointed to are preserved up to the | |
1090 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
1091 | * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a | |
1092 | * %NULL pointer, the object pointed to is freed. | |
1093 | */ | |
1094 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
1095 | { | |
1096 | void *ret; | |
1097 | ||
1098 | if (unlikely(!new_size)) { | |
1099 | kfree(p); | |
1100 | return ZERO_SIZE_PTR; | |
1101 | } | |
1102 | ||
1103 | ret = __do_krealloc(p, new_size, flags); | |
1104 | if (ret && p != ret) | |
1105 | kfree(p); | |
1106 | ||
1107 | return ret; | |
1108 | } | |
1109 | EXPORT_SYMBOL(krealloc); | |
1110 | ||
1111 | /** | |
1112 | * kzfree - like kfree but zero memory | |
1113 | * @p: object to free memory of | |
1114 | * | |
1115 | * The memory of the object @p points to is zeroed before freed. | |
1116 | * If @p is %NULL, kzfree() does nothing. | |
1117 | * | |
1118 | * Note: this function zeroes the whole allocated buffer which can be a good | |
1119 | * deal bigger than the requested buffer size passed to kmalloc(). So be | |
1120 | * careful when using this function in performance sensitive code. | |
1121 | */ | |
1122 | void kzfree(const void *p) | |
1123 | { | |
1124 | size_t ks; | |
1125 | void *mem = (void *)p; | |
1126 | ||
1127 | if (unlikely(ZERO_OR_NULL_PTR(mem))) | |
1128 | return; | |
1129 | ks = ksize(mem); | |
1130 | memset(mem, 0, ks); | |
1131 | kfree(mem); | |
1132 | } | |
1133 | EXPORT_SYMBOL(kzfree); | |
1134 | ||
1135 | /* Tracepoints definitions. */ | |
1136 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); | |
1137 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); | |
1138 | EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); | |
1139 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); | |
1140 | EXPORT_TRACEPOINT_SYMBOL(kfree); | |
1141 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); |