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Commit | Line | Data |
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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> | |
14 | #include <linux/cpu.h> | |
15 | #include <linux/uaccess.h> | |
16 | #include <linux/seq_file.h> | |
17 | #include <linux/proc_fs.h> | |
18 | #include <asm/cacheflush.h> | |
19 | #include <asm/tlbflush.h> | |
20 | #include <asm/page.h> | |
21 | #include <linux/memcontrol.h> | |
22 | ||
23 | #define CREATE_TRACE_POINTS | |
24 | #include <trace/events/kmem.h> | |
25 | ||
26 | #include "slab.h" | |
27 | ||
28 | enum slab_state slab_state; | |
29 | LIST_HEAD(slab_caches); | |
30 | DEFINE_MUTEX(slab_mutex); | |
31 | struct kmem_cache *kmem_cache; | |
32 | ||
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 | SLAB_KASAN) | |
39 | ||
40 | #define SLAB_MERGE_SAME (SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \ | |
41 | SLAB_NOTRACK | SLAB_ACCOUNT) | |
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 | ||
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 | ||
70 | #ifdef CONFIG_DEBUG_VM | |
71 | static int kmem_cache_sanity_check(const char *name, size_t size) | |
72 | { | |
73 | struct kmem_cache *s = NULL; | |
74 | ||
75 | if (!name || in_interrupt() || size < sizeof(void *) || | |
76 | size > KMALLOC_MAX_SIZE) { | |
77 | pr_err("kmem_cache_create(%s) integrity check failed\n", name); | |
78 | return -EINVAL; | |
79 | } | |
80 | ||
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) { | |
92 | pr_err("Slab cache with size %d has lost its name\n", | |
93 | s->object_size); | |
94 | continue; | |
95 | } | |
96 | } | |
97 | ||
98 | WARN_ON(strchr(name, ' ')); /* It confuses parsers */ | |
99 | return 0; | |
100 | } | |
101 | #else | |
102 | static inline int kmem_cache_sanity_check(const char *name, size_t size) | |
103 | { | |
104 | return 0; | |
105 | } | |
106 | #endif | |
107 | ||
108 | void __kmem_cache_free_bulk(struct kmem_cache *s, size_t nr, void **p) | |
109 | { | |
110 | size_t i; | |
111 | ||
112 | for (i = 0; i < nr; i++) { | |
113 | if (s) | |
114 | kmem_cache_free(s, p[i]); | |
115 | else | |
116 | kfree(p[i]); | |
117 | } | |
118 | } | |
119 | ||
120 | int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr, | |
121 | void **p) | |
122 | { | |
123 | size_t i; | |
124 | ||
125 | for (i = 0; i < nr; i++) { | |
126 | void *x = p[i] = kmem_cache_alloc(s, flags); | |
127 | if (!x) { | |
128 | __kmem_cache_free_bulk(s, i, p); | |
129 | return 0; | |
130 | } | |
131 | } | |
132 | return i; | |
133 | } | |
134 | ||
135 | #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) | |
136 | void slab_init_memcg_params(struct kmem_cache *s) | |
137 | { | |
138 | s->memcg_params.is_root_cache = true; | |
139 | INIT_LIST_HEAD(&s->memcg_params.list); | |
140 | RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL); | |
141 | } | |
142 | ||
143 | static int init_memcg_params(struct kmem_cache *s, | |
144 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
145 | { | |
146 | struct memcg_cache_array *arr; | |
147 | ||
148 | if (memcg) { | |
149 | s->memcg_params.is_root_cache = false; | |
150 | s->memcg_params.memcg = memcg; | |
151 | s->memcg_params.root_cache = root_cache; | |
152 | return 0; | |
153 | } | |
154 | ||
155 | slab_init_memcg_params(s); | |
156 | ||
157 | if (!memcg_nr_cache_ids) | |
158 | return 0; | |
159 | ||
160 | arr = kzalloc(sizeof(struct memcg_cache_array) + | |
161 | memcg_nr_cache_ids * sizeof(void *), | |
162 | GFP_KERNEL); | |
163 | if (!arr) | |
164 | return -ENOMEM; | |
165 | ||
166 | RCU_INIT_POINTER(s->memcg_params.memcg_caches, arr); | |
167 | return 0; | |
168 | } | |
169 | ||
170 | static void destroy_memcg_params(struct kmem_cache *s) | |
171 | { | |
172 | if (is_root_cache(s)) | |
173 | kfree(rcu_access_pointer(s->memcg_params.memcg_caches)); | |
174 | } | |
175 | ||
176 | static int update_memcg_params(struct kmem_cache *s, int new_array_size) | |
177 | { | |
178 | struct memcg_cache_array *old, *new; | |
179 | ||
180 | if (!is_root_cache(s)) | |
181 | return 0; | |
182 | ||
183 | new = kzalloc(sizeof(struct memcg_cache_array) + | |
184 | new_array_size * sizeof(void *), GFP_KERNEL); | |
185 | if (!new) | |
186 | return -ENOMEM; | |
187 | ||
188 | old = rcu_dereference_protected(s->memcg_params.memcg_caches, | |
189 | lockdep_is_held(&slab_mutex)); | |
190 | if (old) | |
191 | memcpy(new->entries, old->entries, | |
192 | memcg_nr_cache_ids * sizeof(void *)); | |
193 | ||
194 | rcu_assign_pointer(s->memcg_params.memcg_caches, new); | |
195 | if (old) | |
196 | kfree_rcu(old, rcu); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | int memcg_update_all_caches(int num_memcgs) | |
201 | { | |
202 | struct kmem_cache *s; | |
203 | int ret = 0; | |
204 | ||
205 | mutex_lock(&slab_mutex); | |
206 | list_for_each_entry(s, &slab_caches, list) { | |
207 | ret = update_memcg_params(s, num_memcgs); | |
208 | /* | |
209 | * Instead of freeing the memory, we'll just leave the caches | |
210 | * up to this point in an updated state. | |
211 | */ | |
212 | if (ret) | |
213 | break; | |
214 | } | |
215 | mutex_unlock(&slab_mutex); | |
216 | return ret; | |
217 | } | |
218 | #else | |
219 | static inline int init_memcg_params(struct kmem_cache *s, | |
220 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
221 | { | |
222 | return 0; | |
223 | } | |
224 | ||
225 | static inline void destroy_memcg_params(struct kmem_cache *s) | |
226 | { | |
227 | } | |
228 | #endif /* CONFIG_MEMCG && !CONFIG_SLOB */ | |
229 | ||
230 | /* | |
231 | * Find a mergeable slab cache | |
232 | */ | |
233 | int slab_unmergeable(struct kmem_cache *s) | |
234 | { | |
235 | if (slab_nomerge || (s->flags & SLAB_NEVER_MERGE)) | |
236 | return 1; | |
237 | ||
238 | if (!is_root_cache(s)) | |
239 | return 1; | |
240 | ||
241 | if (s->ctor) | |
242 | return 1; | |
243 | ||
244 | /* | |
245 | * We may have set a slab to be unmergeable during bootstrap. | |
246 | */ | |
247 | if (s->refcount < 0) | |
248 | return 1; | |
249 | ||
250 | return 0; | |
251 | } | |
252 | ||
253 | struct kmem_cache *find_mergeable(size_t size, size_t align, | |
254 | unsigned long flags, const char *name, void (*ctor)(void *)) | |
255 | { | |
256 | struct kmem_cache *s; | |
257 | ||
258 | if (slab_nomerge || (flags & SLAB_NEVER_MERGE)) | |
259 | return NULL; | |
260 | ||
261 | if (ctor) | |
262 | return NULL; | |
263 | ||
264 | size = ALIGN(size, sizeof(void *)); | |
265 | align = calculate_alignment(flags, align, size); | |
266 | size = ALIGN(size, align); | |
267 | flags = kmem_cache_flags(size, flags, name, NULL); | |
268 | ||
269 | list_for_each_entry_reverse(s, &slab_caches, list) { | |
270 | if (slab_unmergeable(s)) | |
271 | continue; | |
272 | ||
273 | if (size > s->size) | |
274 | continue; | |
275 | ||
276 | if ((flags & SLAB_MERGE_SAME) != (s->flags & SLAB_MERGE_SAME)) | |
277 | continue; | |
278 | /* | |
279 | * Check if alignment is compatible. | |
280 | * Courtesy of Adrian Drzewiecki | |
281 | */ | |
282 | if ((s->size & ~(align - 1)) != s->size) | |
283 | continue; | |
284 | ||
285 | if (s->size - size >= sizeof(void *)) | |
286 | continue; | |
287 | ||
288 | if (IS_ENABLED(CONFIG_SLAB) && align && | |
289 | (align > s->align || s->align % align)) | |
290 | continue; | |
291 | ||
292 | return s; | |
293 | } | |
294 | return NULL; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Figure out what the alignment of the objects will be given a set of | |
299 | * flags, a user specified alignment and the size of the objects. | |
300 | */ | |
301 | unsigned long calculate_alignment(unsigned long flags, | |
302 | unsigned long align, unsigned long size) | |
303 | { | |
304 | /* | |
305 | * If the user wants hardware cache aligned objects then follow that | |
306 | * suggestion if the object is sufficiently large. | |
307 | * | |
308 | * The hardware cache alignment cannot override the specified | |
309 | * alignment though. If that is greater then use it. | |
310 | */ | |
311 | if (flags & SLAB_HWCACHE_ALIGN) { | |
312 | unsigned long ralign = cache_line_size(); | |
313 | while (size <= ralign / 2) | |
314 | ralign /= 2; | |
315 | align = max(align, ralign); | |
316 | } | |
317 | ||
318 | if (align < ARCH_SLAB_MINALIGN) | |
319 | align = ARCH_SLAB_MINALIGN; | |
320 | ||
321 | return ALIGN(align, sizeof(void *)); | |
322 | } | |
323 | ||
324 | static struct kmem_cache *create_cache(const char *name, | |
325 | size_t object_size, size_t size, size_t align, | |
326 | unsigned long flags, void (*ctor)(void *), | |
327 | struct mem_cgroup *memcg, struct kmem_cache *root_cache) | |
328 | { | |
329 | struct kmem_cache *s; | |
330 | int err; | |
331 | ||
332 | err = -ENOMEM; | |
333 | s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); | |
334 | if (!s) | |
335 | goto out; | |
336 | ||
337 | s->name = name; | |
338 | s->object_size = object_size; | |
339 | s->size = size; | |
340 | s->align = align; | |
341 | s->ctor = ctor; | |
342 | ||
343 | err = init_memcg_params(s, memcg, root_cache); | |
344 | if (err) | |
345 | goto out_free_cache; | |
346 | ||
347 | err = __kmem_cache_create(s, flags); | |
348 | if (err) | |
349 | goto out_free_cache; | |
350 | ||
351 | s->refcount = 1; | |
352 | list_add(&s->list, &slab_caches); | |
353 | out: | |
354 | if (err) | |
355 | return ERR_PTR(err); | |
356 | return s; | |
357 | ||
358 | out_free_cache: | |
359 | destroy_memcg_params(s); | |
360 | kmem_cache_free(kmem_cache, s); | |
361 | goto out; | |
362 | } | |
363 | ||
364 | /* | |
365 | * kmem_cache_create - Create a cache. | |
366 | * @name: A string which is used in /proc/slabinfo to identify this cache. | |
367 | * @size: The size of objects to be created in this cache. | |
368 | * @align: The required alignment for the objects. | |
369 | * @flags: SLAB flags | |
370 | * @ctor: A constructor for the objects. | |
371 | * | |
372 | * Returns a ptr to the cache on success, NULL on failure. | |
373 | * Cannot be called within a interrupt, but can be interrupted. | |
374 | * The @ctor is run when new pages are allocated by the cache. | |
375 | * | |
376 | * The flags are | |
377 | * | |
378 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
379 | * to catch references to uninitialised memory. | |
380 | * | |
381 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
382 | * for buffer overruns. | |
383 | * | |
384 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
385 | * cacheline. This can be beneficial if you're counting cycles as closely | |
386 | * as davem. | |
387 | */ | |
388 | struct kmem_cache * | |
389 | kmem_cache_create(const char *name, size_t size, size_t align, | |
390 | unsigned long flags, void (*ctor)(void *)) | |
391 | { | |
392 | struct kmem_cache *s = NULL; | |
393 | const char *cache_name; | |
394 | int err; | |
395 | ||
396 | get_online_cpus(); | |
397 | get_online_mems(); | |
398 | memcg_get_cache_ids(); | |
399 | ||
400 | mutex_lock(&slab_mutex); | |
401 | ||
402 | err = kmem_cache_sanity_check(name, size); | |
403 | if (err) { | |
404 | goto out_unlock; | |
405 | } | |
406 | ||
407 | /* Refuse requests with allocator specific flags */ | |
408 | if (flags & ~SLAB_FLAGS_PERMITTED) { | |
409 | err = -EINVAL; | |
410 | goto out_unlock; | |
411 | } | |
412 | ||
413 | /* | |
414 | * Some allocators will constraint the set of valid flags to a subset | |
415 | * of all flags. We expect them to define CACHE_CREATE_MASK in this | |
416 | * case, and we'll just provide them with a sanitized version of the | |
417 | * passed flags. | |
418 | */ | |
419 | flags &= CACHE_CREATE_MASK; | |
420 | ||
421 | s = __kmem_cache_alias(name, size, align, flags, ctor); | |
422 | if (s) | |
423 | goto out_unlock; | |
424 | ||
425 | cache_name = kstrdup_const(name, GFP_KERNEL); | |
426 | if (!cache_name) { | |
427 | err = -ENOMEM; | |
428 | goto out_unlock; | |
429 | } | |
430 | ||
431 | s = create_cache(cache_name, size, size, | |
432 | calculate_alignment(flags, align, size), | |
433 | flags, ctor, NULL, NULL); | |
434 | if (IS_ERR(s)) { | |
435 | err = PTR_ERR(s); | |
436 | kfree_const(cache_name); | |
437 | } | |
438 | ||
439 | out_unlock: | |
440 | mutex_unlock(&slab_mutex); | |
441 | ||
442 | memcg_put_cache_ids(); | |
443 | put_online_mems(); | |
444 | put_online_cpus(); | |
445 | ||
446 | if (err) { | |
447 | if (flags & SLAB_PANIC) | |
448 | panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n", | |
449 | name, err); | |
450 | else { | |
451 | pr_warn("kmem_cache_create(%s) failed with error %d\n", | |
452 | name, err); | |
453 | dump_stack(); | |
454 | } | |
455 | return NULL; | |
456 | } | |
457 | return s; | |
458 | } | |
459 | EXPORT_SYMBOL(kmem_cache_create); | |
460 | ||
461 | static int shutdown_cache(struct kmem_cache *s, | |
462 | struct list_head *release, bool *need_rcu_barrier) | |
463 | { | |
464 | if (__kmem_cache_shutdown(s) != 0) | |
465 | return -EBUSY; | |
466 | ||
467 | if (s->flags & SLAB_DESTROY_BY_RCU) | |
468 | *need_rcu_barrier = true; | |
469 | ||
470 | list_move(&s->list, release); | |
471 | return 0; | |
472 | } | |
473 | ||
474 | static void release_caches(struct list_head *release, bool need_rcu_barrier) | |
475 | { | |
476 | struct kmem_cache *s, *s2; | |
477 | ||
478 | if (need_rcu_barrier) | |
479 | rcu_barrier(); | |
480 | ||
481 | list_for_each_entry_safe(s, s2, release, list) { | |
482 | #ifdef SLAB_SUPPORTS_SYSFS | |
483 | sysfs_slab_remove(s); | |
484 | #else | |
485 | slab_kmem_cache_release(s); | |
486 | #endif | |
487 | } | |
488 | } | |
489 | ||
490 | #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) | |
491 | /* | |
492 | * memcg_create_kmem_cache - Create a cache for a memory cgroup. | |
493 | * @memcg: The memory cgroup the new cache is for. | |
494 | * @root_cache: The parent of the new cache. | |
495 | * | |
496 | * This function attempts to create a kmem cache that will serve allocation | |
497 | * requests going from @memcg to @root_cache. The new cache inherits properties | |
498 | * from its parent. | |
499 | */ | |
500 | void memcg_create_kmem_cache(struct mem_cgroup *memcg, | |
501 | struct kmem_cache *root_cache) | |
502 | { | |
503 | static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */ | |
504 | struct cgroup_subsys_state *css = &memcg->css; | |
505 | struct memcg_cache_array *arr; | |
506 | struct kmem_cache *s = NULL; | |
507 | char *cache_name; | |
508 | int idx; | |
509 | ||
510 | get_online_cpus(); | |
511 | get_online_mems(); | |
512 | ||
513 | mutex_lock(&slab_mutex); | |
514 | ||
515 | /* | |
516 | * The memory cgroup could have been offlined while the cache | |
517 | * creation work was pending. | |
518 | */ | |
519 | if (memcg->kmem_state != KMEM_ONLINE) | |
520 | goto out_unlock; | |
521 | ||
522 | idx = memcg_cache_id(memcg); | |
523 | arr = rcu_dereference_protected(root_cache->memcg_params.memcg_caches, | |
524 | lockdep_is_held(&slab_mutex)); | |
525 | ||
526 | /* | |
527 | * Since per-memcg caches are created asynchronously on first | |
528 | * allocation (see memcg_kmem_get_cache()), several threads can try to | |
529 | * create the same cache, but only one of them may succeed. | |
530 | */ | |
531 | if (arr->entries[idx]) | |
532 | goto out_unlock; | |
533 | ||
534 | cgroup_name(css->cgroup, memcg_name_buf, sizeof(memcg_name_buf)); | |
535 | cache_name = kasprintf(GFP_KERNEL, "%s(%llu:%s)", root_cache->name, | |
536 | css->serial_nr, memcg_name_buf); | |
537 | if (!cache_name) | |
538 | goto out_unlock; | |
539 | ||
540 | s = create_cache(cache_name, root_cache->object_size, | |
541 | root_cache->size, root_cache->align, | |
542 | root_cache->flags & CACHE_CREATE_MASK, | |
543 | root_cache->ctor, memcg, root_cache); | |
544 | /* | |
545 | * If we could not create a memcg cache, do not complain, because | |
546 | * that's not critical at all as we can always proceed with the root | |
547 | * cache. | |
548 | */ | |
549 | if (IS_ERR(s)) { | |
550 | kfree(cache_name); | |
551 | goto out_unlock; | |
552 | } | |
553 | ||
554 | list_add(&s->memcg_params.list, &root_cache->memcg_params.list); | |
555 | ||
556 | /* | |
557 | * Since readers won't lock (see cache_from_memcg_idx()), we need a | |
558 | * barrier here to ensure nobody will see the kmem_cache partially | |
559 | * initialized. | |
560 | */ | |
561 | smp_wmb(); | |
562 | arr->entries[idx] = s; | |
563 | ||
564 | out_unlock: | |
565 | mutex_unlock(&slab_mutex); | |
566 | ||
567 | put_online_mems(); | |
568 | put_online_cpus(); | |
569 | } | |
570 | ||
571 | void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) | |
572 | { | |
573 | int idx; | |
574 | struct memcg_cache_array *arr; | |
575 | struct kmem_cache *s, *c; | |
576 | ||
577 | idx = memcg_cache_id(memcg); | |
578 | ||
579 | get_online_cpus(); | |
580 | get_online_mems(); | |
581 | ||
582 | #ifdef CONFIG_SLUB | |
583 | /* | |
584 | * In case of SLUB, we need to disable empty slab caching to | |
585 | * avoid pinning the offline memory cgroup by freeable kmem | |
586 | * pages charged to it. SLAB doesn't need this, as it | |
587 | * periodically purges unused slabs. | |
588 | */ | |
589 | mutex_lock(&slab_mutex); | |
590 | list_for_each_entry(s, &slab_caches, list) { | |
591 | c = is_root_cache(s) ? cache_from_memcg_idx(s, idx) : NULL; | |
592 | if (c) { | |
593 | c->cpu_partial = 0; | |
594 | c->min_partial = 0; | |
595 | } | |
596 | } | |
597 | mutex_unlock(&slab_mutex); | |
598 | /* | |
599 | * kmem_cache->cpu_partial is checked locklessly (see | |
600 | * put_cpu_partial()). Make sure the change is visible. | |
601 | */ | |
602 | synchronize_sched(); | |
603 | #endif | |
604 | ||
605 | mutex_lock(&slab_mutex); | |
606 | list_for_each_entry(s, &slab_caches, list) { | |
607 | if (!is_root_cache(s)) | |
608 | continue; | |
609 | ||
610 | arr = rcu_dereference_protected(s->memcg_params.memcg_caches, | |
611 | lockdep_is_held(&slab_mutex)); | |
612 | c = arr->entries[idx]; | |
613 | if (!c) | |
614 | continue; | |
615 | ||
616 | __kmem_cache_shrink(c); | |
617 | arr->entries[idx] = NULL; | |
618 | } | |
619 | mutex_unlock(&slab_mutex); | |
620 | ||
621 | put_online_mems(); | |
622 | put_online_cpus(); | |
623 | } | |
624 | ||
625 | static int __shutdown_memcg_cache(struct kmem_cache *s, | |
626 | struct list_head *release, bool *need_rcu_barrier) | |
627 | { | |
628 | BUG_ON(is_root_cache(s)); | |
629 | ||
630 | if (shutdown_cache(s, release, need_rcu_barrier)) | |
631 | return -EBUSY; | |
632 | ||
633 | list_del(&s->memcg_params.list); | |
634 | return 0; | |
635 | } | |
636 | ||
637 | void memcg_destroy_kmem_caches(struct mem_cgroup *memcg) | |
638 | { | |
639 | LIST_HEAD(release); | |
640 | bool need_rcu_barrier = false; | |
641 | struct kmem_cache *s, *s2; | |
642 | ||
643 | get_online_cpus(); | |
644 | get_online_mems(); | |
645 | ||
646 | mutex_lock(&slab_mutex); | |
647 | list_for_each_entry_safe(s, s2, &slab_caches, list) { | |
648 | if (is_root_cache(s) || s->memcg_params.memcg != memcg) | |
649 | continue; | |
650 | /* | |
651 | * The cgroup is about to be freed and therefore has no charges | |
652 | * left. Hence, all its caches must be empty by now. | |
653 | */ | |
654 | BUG_ON(__shutdown_memcg_cache(s, &release, &need_rcu_barrier)); | |
655 | } | |
656 | mutex_unlock(&slab_mutex); | |
657 | ||
658 | put_online_mems(); | |
659 | put_online_cpus(); | |
660 | ||
661 | release_caches(&release, need_rcu_barrier); | |
662 | } | |
663 | ||
664 | static int shutdown_memcg_caches(struct kmem_cache *s, | |
665 | struct list_head *release, bool *need_rcu_barrier) | |
666 | { | |
667 | struct memcg_cache_array *arr; | |
668 | struct kmem_cache *c, *c2; | |
669 | LIST_HEAD(busy); | |
670 | int i; | |
671 | ||
672 | BUG_ON(!is_root_cache(s)); | |
673 | ||
674 | /* | |
675 | * First, shutdown active caches, i.e. caches that belong to online | |
676 | * memory cgroups. | |
677 | */ | |
678 | arr = rcu_dereference_protected(s->memcg_params.memcg_caches, | |
679 | lockdep_is_held(&slab_mutex)); | |
680 | for_each_memcg_cache_index(i) { | |
681 | c = arr->entries[i]; | |
682 | if (!c) | |
683 | continue; | |
684 | if (__shutdown_memcg_cache(c, release, need_rcu_barrier)) | |
685 | /* | |
686 | * The cache still has objects. Move it to a temporary | |
687 | * list so as not to try to destroy it for a second | |
688 | * time while iterating over inactive caches below. | |
689 | */ | |
690 | list_move(&c->memcg_params.list, &busy); | |
691 | else | |
692 | /* | |
693 | * The cache is empty and will be destroyed soon. Clear | |
694 | * the pointer to it in the memcg_caches array so that | |
695 | * it will never be accessed even if the root cache | |
696 | * stays alive. | |
697 | */ | |
698 | arr->entries[i] = NULL; | |
699 | } | |
700 | ||
701 | /* | |
702 | * Second, shutdown all caches left from memory cgroups that are now | |
703 | * offline. | |
704 | */ | |
705 | list_for_each_entry_safe(c, c2, &s->memcg_params.list, | |
706 | memcg_params.list) | |
707 | __shutdown_memcg_cache(c, release, need_rcu_barrier); | |
708 | ||
709 | list_splice(&busy, &s->memcg_params.list); | |
710 | ||
711 | /* | |
712 | * A cache being destroyed must be empty. In particular, this means | |
713 | * that all per memcg caches attached to it must be empty too. | |
714 | */ | |
715 | if (!list_empty(&s->memcg_params.list)) | |
716 | return -EBUSY; | |
717 | return 0; | |
718 | } | |
719 | #else | |
720 | static inline int shutdown_memcg_caches(struct kmem_cache *s, | |
721 | struct list_head *release, bool *need_rcu_barrier) | |
722 | { | |
723 | return 0; | |
724 | } | |
725 | #endif /* CONFIG_MEMCG && !CONFIG_SLOB */ | |
726 | ||
727 | void slab_kmem_cache_release(struct kmem_cache *s) | |
728 | { | |
729 | __kmem_cache_release(s); | |
730 | destroy_memcg_params(s); | |
731 | kfree_const(s->name); | |
732 | kmem_cache_free(kmem_cache, s); | |
733 | } | |
734 | ||
735 | void kmem_cache_destroy(struct kmem_cache *s) | |
736 | { | |
737 | LIST_HEAD(release); | |
738 | bool need_rcu_barrier = false; | |
739 | int err; | |
740 | ||
741 | if (unlikely(!s)) | |
742 | return; | |
743 | ||
744 | get_online_cpus(); | |
745 | get_online_mems(); | |
746 | ||
747 | kasan_cache_destroy(s); | |
748 | mutex_lock(&slab_mutex); | |
749 | ||
750 | s->refcount--; | |
751 | if (s->refcount) | |
752 | goto out_unlock; | |
753 | ||
754 | err = shutdown_memcg_caches(s, &release, &need_rcu_barrier); | |
755 | if (!err) | |
756 | err = shutdown_cache(s, &release, &need_rcu_barrier); | |
757 | ||
758 | if (err) { | |
759 | pr_err("kmem_cache_destroy %s: Slab cache still has objects\n", | |
760 | s->name); | |
761 | dump_stack(); | |
762 | } | |
763 | out_unlock: | |
764 | mutex_unlock(&slab_mutex); | |
765 | ||
766 | put_online_mems(); | |
767 | put_online_cpus(); | |
768 | ||
769 | release_caches(&release, need_rcu_barrier); | |
770 | } | |
771 | EXPORT_SYMBOL(kmem_cache_destroy); | |
772 | ||
773 | /** | |
774 | * kmem_cache_shrink - Shrink a cache. | |
775 | * @cachep: The cache to shrink. | |
776 | * | |
777 | * Releases as many slabs as possible for a cache. | |
778 | * To help debugging, a zero exit status indicates all slabs were released. | |
779 | */ | |
780 | int kmem_cache_shrink(struct kmem_cache *cachep) | |
781 | { | |
782 | int ret; | |
783 | ||
784 | get_online_cpus(); | |
785 | get_online_mems(); | |
786 | kasan_cache_shrink(cachep); | |
787 | ret = __kmem_cache_shrink(cachep); | |
788 | put_online_mems(); | |
789 | put_online_cpus(); | |
790 | return ret; | |
791 | } | |
792 | EXPORT_SYMBOL(kmem_cache_shrink); | |
793 | ||
794 | bool slab_is_available(void) | |
795 | { | |
796 | return slab_state >= UP; | |
797 | } | |
798 | ||
799 | #ifndef CONFIG_SLOB | |
800 | /* Create a cache during boot when no slab services are available yet */ | |
801 | void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size, | |
802 | unsigned long flags) | |
803 | { | |
804 | int err; | |
805 | ||
806 | s->name = name; | |
807 | s->size = s->object_size = size; | |
808 | s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size); | |
809 | ||
810 | slab_init_memcg_params(s); | |
811 | ||
812 | err = __kmem_cache_create(s, flags); | |
813 | ||
814 | if (err) | |
815 | panic("Creation of kmalloc slab %s size=%zu failed. Reason %d\n", | |
816 | name, size, err); | |
817 | ||
818 | s->refcount = -1; /* Exempt from merging for now */ | |
819 | } | |
820 | ||
821 | struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size, | |
822 | unsigned long flags) | |
823 | { | |
824 | struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT); | |
825 | ||
826 | if (!s) | |
827 | panic("Out of memory when creating slab %s\n", name); | |
828 | ||
829 | create_boot_cache(s, name, size, flags); | |
830 | list_add(&s->list, &slab_caches); | |
831 | s->refcount = 1; | |
832 | return s; | |
833 | } | |
834 | ||
835 | struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1]; | |
836 | EXPORT_SYMBOL(kmalloc_caches); | |
837 | ||
838 | #ifdef CONFIG_ZONE_DMA | |
839 | struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1]; | |
840 | EXPORT_SYMBOL(kmalloc_dma_caches); | |
841 | #endif | |
842 | ||
843 | /* | |
844 | * Conversion table for small slabs sizes / 8 to the index in the | |
845 | * kmalloc array. This is necessary for slabs < 192 since we have non power | |
846 | * of two cache sizes there. The size of larger slabs can be determined using | |
847 | * fls. | |
848 | */ | |
849 | static s8 size_index[24] = { | |
850 | 3, /* 8 */ | |
851 | 4, /* 16 */ | |
852 | 5, /* 24 */ | |
853 | 5, /* 32 */ | |
854 | 6, /* 40 */ | |
855 | 6, /* 48 */ | |
856 | 6, /* 56 */ | |
857 | 6, /* 64 */ | |
858 | 1, /* 72 */ | |
859 | 1, /* 80 */ | |
860 | 1, /* 88 */ | |
861 | 1, /* 96 */ | |
862 | 7, /* 104 */ | |
863 | 7, /* 112 */ | |
864 | 7, /* 120 */ | |
865 | 7, /* 128 */ | |
866 | 2, /* 136 */ | |
867 | 2, /* 144 */ | |
868 | 2, /* 152 */ | |
869 | 2, /* 160 */ | |
870 | 2, /* 168 */ | |
871 | 2, /* 176 */ | |
872 | 2, /* 184 */ | |
873 | 2 /* 192 */ | |
874 | }; | |
875 | ||
876 | static inline int size_index_elem(size_t bytes) | |
877 | { | |
878 | return (bytes - 1) / 8; | |
879 | } | |
880 | ||
881 | /* | |
882 | * Find the kmem_cache structure that serves a given size of | |
883 | * allocation | |
884 | */ | |
885 | struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags) | |
886 | { | |
887 | int index; | |
888 | ||
889 | if (unlikely(size > KMALLOC_MAX_SIZE)) { | |
890 | WARN_ON_ONCE(!(flags & __GFP_NOWARN)); | |
891 | return NULL; | |
892 | } | |
893 | ||
894 | if (size <= 192) { | |
895 | if (!size) | |
896 | return ZERO_SIZE_PTR; | |
897 | ||
898 | index = size_index[size_index_elem(size)]; | |
899 | } else | |
900 | index = fls(size - 1); | |
901 | ||
902 | #ifdef CONFIG_ZONE_DMA | |
903 | if (unlikely((flags & GFP_DMA))) | |
904 | return kmalloc_dma_caches[index]; | |
905 | ||
906 | #endif | |
907 | return kmalloc_caches[index]; | |
908 | } | |
909 | ||
910 | /* | |
911 | * kmalloc_info[] is to make slub_debug=,kmalloc-xx option work at boot time. | |
912 | * kmalloc_index() supports up to 2^26=64MB, so the final entry of the table is | |
913 | * kmalloc-67108864. | |
914 | */ | |
915 | static struct { | |
916 | const char *name; | |
917 | unsigned long size; | |
918 | } const kmalloc_info[] __initconst = { | |
919 | {NULL, 0}, {"kmalloc-96", 96}, | |
920 | {"kmalloc-192", 192}, {"kmalloc-8", 8}, | |
921 | {"kmalloc-16", 16}, {"kmalloc-32", 32}, | |
922 | {"kmalloc-64", 64}, {"kmalloc-128", 128}, | |
923 | {"kmalloc-256", 256}, {"kmalloc-512", 512}, | |
924 | {"kmalloc-1024", 1024}, {"kmalloc-2048", 2048}, | |
925 | {"kmalloc-4096", 4096}, {"kmalloc-8192", 8192}, | |
926 | {"kmalloc-16384", 16384}, {"kmalloc-32768", 32768}, | |
927 | {"kmalloc-65536", 65536}, {"kmalloc-131072", 131072}, | |
928 | {"kmalloc-262144", 262144}, {"kmalloc-524288", 524288}, | |
929 | {"kmalloc-1048576", 1048576}, {"kmalloc-2097152", 2097152}, | |
930 | {"kmalloc-4194304", 4194304}, {"kmalloc-8388608", 8388608}, | |
931 | {"kmalloc-16777216", 16777216}, {"kmalloc-33554432", 33554432}, | |
932 | {"kmalloc-67108864", 67108864} | |
933 | }; | |
934 | ||
935 | /* | |
936 | * Patch up the size_index table if we have strange large alignment | |
937 | * requirements for the kmalloc array. This is only the case for | |
938 | * MIPS it seems. The standard arches will not generate any code here. | |
939 | * | |
940 | * Largest permitted alignment is 256 bytes due to the way we | |
941 | * handle the index determination for the smaller caches. | |
942 | * | |
943 | * Make sure that nothing crazy happens if someone starts tinkering | |
944 | * around with ARCH_KMALLOC_MINALIGN | |
945 | */ | |
946 | void __init setup_kmalloc_cache_index_table(void) | |
947 | { | |
948 | int i; | |
949 | ||
950 | BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 || | |
951 | (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1))); | |
952 | ||
953 | for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) { | |
954 | int elem = size_index_elem(i); | |
955 | ||
956 | if (elem >= ARRAY_SIZE(size_index)) | |
957 | break; | |
958 | size_index[elem] = KMALLOC_SHIFT_LOW; | |
959 | } | |
960 | ||
961 | if (KMALLOC_MIN_SIZE >= 64) { | |
962 | /* | |
963 | * The 96 byte size cache is not used if the alignment | |
964 | * is 64 byte. | |
965 | */ | |
966 | for (i = 64 + 8; i <= 96; i += 8) | |
967 | size_index[size_index_elem(i)] = 7; | |
968 | ||
969 | } | |
970 | ||
971 | if (KMALLOC_MIN_SIZE >= 128) { | |
972 | /* | |
973 | * The 192 byte sized cache is not used if the alignment | |
974 | * is 128 byte. Redirect kmalloc to use the 256 byte cache | |
975 | * instead. | |
976 | */ | |
977 | for (i = 128 + 8; i <= 192; i += 8) | |
978 | size_index[size_index_elem(i)] = 8; | |
979 | } | |
980 | } | |
981 | ||
982 | static void __init new_kmalloc_cache(int idx, unsigned long flags) | |
983 | { | |
984 | kmalloc_caches[idx] = create_kmalloc_cache(kmalloc_info[idx].name, | |
985 | kmalloc_info[idx].size, flags); | |
986 | } | |
987 | ||
988 | /* | |
989 | * Create the kmalloc array. Some of the regular kmalloc arrays | |
990 | * may already have been created because they were needed to | |
991 | * enable allocations for slab creation. | |
992 | */ | |
993 | void __init create_kmalloc_caches(unsigned long flags) | |
994 | { | |
995 | int i; | |
996 | ||
997 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { | |
998 | if (!kmalloc_caches[i]) | |
999 | new_kmalloc_cache(i, flags); | |
1000 | ||
1001 | /* | |
1002 | * Caches that are not of the two-to-the-power-of size. | |
1003 | * These have to be created immediately after the | |
1004 | * earlier power of two caches | |
1005 | */ | |
1006 | if (KMALLOC_MIN_SIZE <= 32 && !kmalloc_caches[1] && i == 6) | |
1007 | new_kmalloc_cache(1, flags); | |
1008 | if (KMALLOC_MIN_SIZE <= 64 && !kmalloc_caches[2] && i == 7) | |
1009 | new_kmalloc_cache(2, flags); | |
1010 | } | |
1011 | ||
1012 | /* Kmalloc array is now usable */ | |
1013 | slab_state = UP; | |
1014 | ||
1015 | #ifdef CONFIG_ZONE_DMA | |
1016 | for (i = 0; i <= KMALLOC_SHIFT_HIGH; i++) { | |
1017 | struct kmem_cache *s = kmalloc_caches[i]; | |
1018 | ||
1019 | if (s) { | |
1020 | int size = kmalloc_size(i); | |
1021 | char *n = kasprintf(GFP_NOWAIT, | |
1022 | "dma-kmalloc-%d", size); | |
1023 | ||
1024 | BUG_ON(!n); | |
1025 | kmalloc_dma_caches[i] = create_kmalloc_cache(n, | |
1026 | size, SLAB_CACHE_DMA | flags); | |
1027 | } | |
1028 | } | |
1029 | #endif | |
1030 | } | |
1031 | #endif /* !CONFIG_SLOB */ | |
1032 | ||
1033 | /* | |
1034 | * To avoid unnecessary overhead, we pass through large allocation requests | |
1035 | * directly to the page allocator. We use __GFP_COMP, because we will need to | |
1036 | * know the allocation order to free the pages properly in kfree. | |
1037 | */ | |
1038 | void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) | |
1039 | { | |
1040 | void *ret; | |
1041 | struct page *page; | |
1042 | ||
1043 | flags |= __GFP_COMP; | |
1044 | page = alloc_pages(flags, order); | |
1045 | ret = page ? page_address(page) : NULL; | |
1046 | kmemleak_alloc(ret, size, 1, flags); | |
1047 | kasan_kmalloc_large(ret, size, flags); | |
1048 | return ret; | |
1049 | } | |
1050 | EXPORT_SYMBOL(kmalloc_order); | |
1051 | ||
1052 | #ifdef CONFIG_TRACING | |
1053 | void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order) | |
1054 | { | |
1055 | void *ret = kmalloc_order(size, flags, order); | |
1056 | trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags); | |
1057 | return ret; | |
1058 | } | |
1059 | EXPORT_SYMBOL(kmalloc_order_trace); | |
1060 | #endif | |
1061 | ||
1062 | #ifdef CONFIG_SLAB_FREELIST_RANDOM | |
1063 | /* Randomize a generic freelist */ | |
1064 | static void freelist_randomize(struct rnd_state *state, unsigned int *list, | |
1065 | size_t count) | |
1066 | { | |
1067 | size_t i; | |
1068 | unsigned int rand; | |
1069 | ||
1070 | for (i = 0; i < count; i++) | |
1071 | list[i] = i; | |
1072 | ||
1073 | /* Fisher-Yates shuffle */ | |
1074 | for (i = count - 1; i > 0; i--) { | |
1075 | rand = prandom_u32_state(state); | |
1076 | rand %= (i + 1); | |
1077 | swap(list[i], list[rand]); | |
1078 | } | |
1079 | } | |
1080 | ||
1081 | /* Create a random sequence per cache */ | |
1082 | int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, | |
1083 | gfp_t gfp) | |
1084 | { | |
1085 | struct rnd_state state; | |
1086 | ||
1087 | if (count < 2 || cachep->random_seq) | |
1088 | return 0; | |
1089 | ||
1090 | cachep->random_seq = kcalloc(count, sizeof(unsigned int), gfp); | |
1091 | if (!cachep->random_seq) | |
1092 | return -ENOMEM; | |
1093 | ||
1094 | /* Get best entropy at this stage of boot */ | |
1095 | prandom_seed_state(&state, get_random_long()); | |
1096 | ||
1097 | freelist_randomize(&state, cachep->random_seq, count); | |
1098 | return 0; | |
1099 | } | |
1100 | ||
1101 | /* Destroy the per-cache random freelist sequence */ | |
1102 | void cache_random_seq_destroy(struct kmem_cache *cachep) | |
1103 | { | |
1104 | kfree(cachep->random_seq); | |
1105 | cachep->random_seq = NULL; | |
1106 | } | |
1107 | #endif /* CONFIG_SLAB_FREELIST_RANDOM */ | |
1108 | ||
1109 | #ifdef CONFIG_SLABINFO | |
1110 | ||
1111 | #ifdef CONFIG_SLAB | |
1112 | #define SLABINFO_RIGHTS (S_IWUSR | S_IRUSR) | |
1113 | #else | |
1114 | #define SLABINFO_RIGHTS S_IRUSR | |
1115 | #endif | |
1116 | ||
1117 | static void print_slabinfo_header(struct seq_file *m) | |
1118 | { | |
1119 | /* | |
1120 | * Output format version, so at least we can change it | |
1121 | * without _too_ many complaints. | |
1122 | */ | |
1123 | #ifdef CONFIG_DEBUG_SLAB | |
1124 | seq_puts(m, "slabinfo - version: 2.1 (statistics)\n"); | |
1125 | #else | |
1126 | seq_puts(m, "slabinfo - version: 2.1\n"); | |
1127 | #endif | |
1128 | seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); | |
1129 | seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); | |
1130 | seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); | |
1131 | #ifdef CONFIG_DEBUG_SLAB | |
1132 | seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>"); | |
1133 | seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>"); | |
1134 | #endif | |
1135 | seq_putc(m, '\n'); | |
1136 | } | |
1137 | ||
1138 | void *slab_start(struct seq_file *m, loff_t *pos) | |
1139 | { | |
1140 | mutex_lock(&slab_mutex); | |
1141 | return seq_list_start(&slab_caches, *pos); | |
1142 | } | |
1143 | ||
1144 | void *slab_next(struct seq_file *m, void *p, loff_t *pos) | |
1145 | { | |
1146 | return seq_list_next(p, &slab_caches, pos); | |
1147 | } | |
1148 | ||
1149 | void slab_stop(struct seq_file *m, void *p) | |
1150 | { | |
1151 | mutex_unlock(&slab_mutex); | |
1152 | } | |
1153 | ||
1154 | static void | |
1155 | memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info) | |
1156 | { | |
1157 | struct kmem_cache *c; | |
1158 | struct slabinfo sinfo; | |
1159 | ||
1160 | if (!is_root_cache(s)) | |
1161 | return; | |
1162 | ||
1163 | for_each_memcg_cache(c, s) { | |
1164 | memset(&sinfo, 0, sizeof(sinfo)); | |
1165 | get_slabinfo(c, &sinfo); | |
1166 | ||
1167 | info->active_slabs += sinfo.active_slabs; | |
1168 | info->num_slabs += sinfo.num_slabs; | |
1169 | info->shared_avail += sinfo.shared_avail; | |
1170 | info->active_objs += sinfo.active_objs; | |
1171 | info->num_objs += sinfo.num_objs; | |
1172 | } | |
1173 | } | |
1174 | ||
1175 | static void cache_show(struct kmem_cache *s, struct seq_file *m) | |
1176 | { | |
1177 | struct slabinfo sinfo; | |
1178 | ||
1179 | memset(&sinfo, 0, sizeof(sinfo)); | |
1180 | get_slabinfo(s, &sinfo); | |
1181 | ||
1182 | memcg_accumulate_slabinfo(s, &sinfo); | |
1183 | ||
1184 | seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", | |
1185 | cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, | |
1186 | sinfo.objects_per_slab, (1 << sinfo.cache_order)); | |
1187 | ||
1188 | seq_printf(m, " : tunables %4u %4u %4u", | |
1189 | sinfo.limit, sinfo.batchcount, sinfo.shared); | |
1190 | seq_printf(m, " : slabdata %6lu %6lu %6lu", | |
1191 | sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); | |
1192 | slabinfo_show_stats(m, s); | |
1193 | seq_putc(m, '\n'); | |
1194 | } | |
1195 | ||
1196 | static int slab_show(struct seq_file *m, void *p) | |
1197 | { | |
1198 | struct kmem_cache *s = list_entry(p, struct kmem_cache, list); | |
1199 | ||
1200 | if (p == slab_caches.next) | |
1201 | print_slabinfo_header(m); | |
1202 | if (is_root_cache(s)) | |
1203 | cache_show(s, m); | |
1204 | return 0; | |
1205 | } | |
1206 | ||
1207 | #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) | |
1208 | int memcg_slab_show(struct seq_file *m, void *p) | |
1209 | { | |
1210 | struct kmem_cache *s = list_entry(p, struct kmem_cache, list); | |
1211 | struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); | |
1212 | ||
1213 | if (p == slab_caches.next) | |
1214 | print_slabinfo_header(m); | |
1215 | if (!is_root_cache(s) && s->memcg_params.memcg == memcg) | |
1216 | cache_show(s, m); | |
1217 | return 0; | |
1218 | } | |
1219 | #endif | |
1220 | ||
1221 | /* | |
1222 | * slabinfo_op - iterator that generates /proc/slabinfo | |
1223 | * | |
1224 | * Output layout: | |
1225 | * cache-name | |
1226 | * num-active-objs | |
1227 | * total-objs | |
1228 | * object size | |
1229 | * num-active-slabs | |
1230 | * total-slabs | |
1231 | * num-pages-per-slab | |
1232 | * + further values on SMP and with statistics enabled | |
1233 | */ | |
1234 | static const struct seq_operations slabinfo_op = { | |
1235 | .start = slab_start, | |
1236 | .next = slab_next, | |
1237 | .stop = slab_stop, | |
1238 | .show = slab_show, | |
1239 | }; | |
1240 | ||
1241 | static int slabinfo_open(struct inode *inode, struct file *file) | |
1242 | { | |
1243 | return seq_open(file, &slabinfo_op); | |
1244 | } | |
1245 | ||
1246 | static const struct file_operations proc_slabinfo_operations = { | |
1247 | .open = slabinfo_open, | |
1248 | .read = seq_read, | |
1249 | .write = slabinfo_write, | |
1250 | .llseek = seq_lseek, | |
1251 | .release = seq_release, | |
1252 | }; | |
1253 | ||
1254 | static int __init slab_proc_init(void) | |
1255 | { | |
1256 | proc_create("slabinfo", SLABINFO_RIGHTS, NULL, | |
1257 | &proc_slabinfo_operations); | |
1258 | return 0; | |
1259 | } | |
1260 | module_init(slab_proc_init); | |
1261 | #endif /* CONFIG_SLABINFO */ | |
1262 | ||
1263 | static __always_inline void *__do_krealloc(const void *p, size_t new_size, | |
1264 | gfp_t flags) | |
1265 | { | |
1266 | void *ret; | |
1267 | size_t ks = 0; | |
1268 | ||
1269 | if (p) | |
1270 | ks = ksize(p); | |
1271 | ||
1272 | if (ks >= new_size) { | |
1273 | kasan_krealloc((void *)p, new_size, flags); | |
1274 | return (void *)p; | |
1275 | } | |
1276 | ||
1277 | ret = kmalloc_track_caller(new_size, flags); | |
1278 | if (ret && p) | |
1279 | memcpy(ret, p, ks); | |
1280 | ||
1281 | return ret; | |
1282 | } | |
1283 | ||
1284 | /** | |
1285 | * __krealloc - like krealloc() but don't free @p. | |
1286 | * @p: object to reallocate memory for. | |
1287 | * @new_size: how many bytes of memory are required. | |
1288 | * @flags: the type of memory to allocate. | |
1289 | * | |
1290 | * This function is like krealloc() except it never frees the originally | |
1291 | * allocated buffer. Use this if you don't want to free the buffer immediately | |
1292 | * like, for example, with RCU. | |
1293 | */ | |
1294 | void *__krealloc(const void *p, size_t new_size, gfp_t flags) | |
1295 | { | |
1296 | if (unlikely(!new_size)) | |
1297 | return ZERO_SIZE_PTR; | |
1298 | ||
1299 | return __do_krealloc(p, new_size, flags); | |
1300 | ||
1301 | } | |
1302 | EXPORT_SYMBOL(__krealloc); | |
1303 | ||
1304 | /** | |
1305 | * krealloc - reallocate memory. The contents will remain unchanged. | |
1306 | * @p: object to reallocate memory for. | |
1307 | * @new_size: how many bytes of memory are required. | |
1308 | * @flags: the type of memory to allocate. | |
1309 | * | |
1310 | * The contents of the object pointed to are preserved up to the | |
1311 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
1312 | * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a | |
1313 | * %NULL pointer, the object pointed to is freed. | |
1314 | */ | |
1315 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
1316 | { | |
1317 | void *ret; | |
1318 | ||
1319 | if (unlikely(!new_size)) { | |
1320 | kfree(p); | |
1321 | return ZERO_SIZE_PTR; | |
1322 | } | |
1323 | ||
1324 | ret = __do_krealloc(p, new_size, flags); | |
1325 | if (ret && p != ret) | |
1326 | kfree(p); | |
1327 | ||
1328 | return ret; | |
1329 | } | |
1330 | EXPORT_SYMBOL(krealloc); | |
1331 | ||
1332 | /** | |
1333 | * kzfree - like kfree but zero memory | |
1334 | * @p: object to free memory of | |
1335 | * | |
1336 | * The memory of the object @p points to is zeroed before freed. | |
1337 | * If @p is %NULL, kzfree() does nothing. | |
1338 | * | |
1339 | * Note: this function zeroes the whole allocated buffer which can be a good | |
1340 | * deal bigger than the requested buffer size passed to kmalloc(). So be | |
1341 | * careful when using this function in performance sensitive code. | |
1342 | */ | |
1343 | void kzfree(const void *p) | |
1344 | { | |
1345 | size_t ks; | |
1346 | void *mem = (void *)p; | |
1347 | ||
1348 | if (unlikely(ZERO_OR_NULL_PTR(mem))) | |
1349 | return; | |
1350 | ks = ksize(mem); | |
1351 | memset(mem, 0, ks); | |
1352 | kfree(mem); | |
1353 | } | |
1354 | EXPORT_SYMBOL(kzfree); | |
1355 | ||
1356 | /* Tracepoints definitions. */ | |
1357 | EXPORT_TRACEPOINT_SYMBOL(kmalloc); | |
1358 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc); | |
1359 | EXPORT_TRACEPOINT_SYMBOL(kmalloc_node); | |
1360 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node); | |
1361 | EXPORT_TRACEPOINT_SYMBOL(kfree); | |
1362 | EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free); |