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1 | // SPDX-License-Identifier: GPL-2.0 |
---|---|
2 | /* |
3 | * linux/mm/slab.c |
4 | * Written by Mark Hemment, 1996/97. |
5 | * (markhe@nextd.demon.co.uk) |
6 | * |
7 | * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli |
8 | * |
9 | * Major cleanup, different bufctl logic, per-cpu arrays |
10 | * (c) 2000 Manfred Spraul |
11 | * |
12 | * Cleanup, make the head arrays unconditional, preparation for NUMA |
13 | * (c) 2002 Manfred Spraul |
14 | * |
15 | * An implementation of the Slab Allocator as described in outline in; |
16 | * UNIX Internals: The New Frontiers by Uresh Vahalia |
17 | * Pub: Prentice Hall ISBN 0-13-101908-2 |
18 | * or with a little more detail in; |
19 | * The Slab Allocator: An Object-Caching Kernel Memory Allocator |
20 | * Jeff Bonwick (Sun Microsystems). |
21 | * Presented at: USENIX Summer 1994 Technical Conference |
22 | * |
23 | * The memory is organized in caches, one cache for each object type. |
24 | * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) |
25 | * Each cache consists out of many slabs (they are small (usually one |
26 | * page long) and always contiguous), and each slab contains multiple |
27 | * initialized objects. |
28 | * |
29 | * This means, that your constructor is used only for newly allocated |
30 | * slabs and you must pass objects with the same initializations to |
31 | * kmem_cache_free. |
32 | * |
33 | * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM, |
34 | * normal). If you need a special memory type, then must create a new |
35 | * cache for that memory type. |
36 | * |
37 | * In order to reduce fragmentation, the slabs are sorted in 3 groups: |
38 | * full slabs with 0 free objects |
39 | * partial slabs |
40 | * empty slabs with no allocated objects |
41 | * |
42 | * If partial slabs exist, then new allocations come from these slabs, |
43 | * otherwise from empty slabs or new slabs are allocated. |
44 | * |
45 | * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache |
46 | * during kmem_cache_destroy(). The caller must prevent concurrent allocs. |
47 | * |
48 | * Each cache has a short per-cpu head array, most allocs |
49 | * and frees go into that array, and if that array overflows, then 1/2 |
50 | * of the entries in the array are given back into the global cache. |
51 | * The head array is strictly LIFO and should improve the cache hit rates. |
52 | * On SMP, it additionally reduces the spinlock operations. |
53 | * |
54 | * The c_cpuarray may not be read with enabled local interrupts - |
55 | * it's changed with a smp_call_function(). |
56 | * |
57 | * SMP synchronization: |
58 | * constructors and destructors are called without any locking. |
59 | * Several members in struct kmem_cache and struct slab never change, they |
60 | * are accessed without any locking. |
61 | * The per-cpu arrays are never accessed from the wrong cpu, no locking, |
62 | * and local interrupts are disabled so slab code is preempt-safe. |
63 | * The non-constant members are protected with a per-cache irq spinlock. |
64 | * |
65 | * Many thanks to Mark Hemment, who wrote another per-cpu slab patch |
66 | * in 2000 - many ideas in the current implementation are derived from |
67 | * his patch. |
68 | * |
69 | * Further notes from the original documentation: |
70 | * |
71 | * 11 April '97. Started multi-threading - markhe |
72 | * The global cache-chain is protected by the mutex 'slab_mutex'. |
73 | * The sem is only needed when accessing/extending the cache-chain, which |
74 | * can never happen inside an interrupt (kmem_cache_create(), |
75 | * kmem_cache_shrink() and kmem_cache_reap()). |
76 | * |
77 | * At present, each engine can be growing a cache. This should be blocked. |
78 | * |
79 | * 15 March 2005. NUMA slab allocator. |
80 | * Shai Fultheim <shai@scalex86.org>. |
81 | * Shobhit Dayal <shobhit@calsoftinc.com> |
82 | * Alok N Kataria <alokk@calsoftinc.com> |
83 | * Christoph Lameter <christoph@lameter.com> |
84 | * |
85 | * Modified the slab allocator to be node aware on NUMA systems. |
86 | * Each node has its own list of partial, free and full slabs. |
87 | * All object allocations for a node occur from node specific slab lists. |
88 | */ |
89 | |
90 | #include <linux/slab.h> |
91 | #include <linux/mm.h> |
92 | #include <linux/poison.h> |
93 | #include <linux/swap.h> |
94 | #include <linux/cache.h> |
95 | #include <linux/interrupt.h> |
96 | #include <linux/init.h> |
97 | #include <linux/compiler.h> |
98 | #include <linux/cpuset.h> |
99 | #include <linux/proc_fs.h> |
100 | #include <linux/seq_file.h> |
101 | #include <linux/notifier.h> |
102 | #include <linux/kallsyms.h> |
103 | #include <linux/cpu.h> |
104 | #include <linux/sysctl.h> |
105 | #include <linux/module.h> |
106 | #include <linux/rcupdate.h> |
107 | #include <linux/string.h> |
108 | #include <linux/uaccess.h> |
109 | #include <linux/nodemask.h> |
110 | #include <linux/kmemleak.h> |
111 | #include <linux/mempolicy.h> |
112 | #include <linux/mutex.h> |
113 | #include <linux/fault-inject.h> |
114 | #include <linux/rtmutex.h> |
115 | #include <linux/reciprocal_div.h> |
116 | #include <linux/debugobjects.h> |
117 | #include <linux/memory.h> |
118 | #include <linux/prefetch.h> |
119 | #include <linux/sched/task_stack.h> |
120 | |
121 | #include <net/sock.h> |
122 | |
123 | #include <asm/cacheflush.h> |
124 | #include <asm/tlbflush.h> |
125 | #include <asm/page.h> |
126 | |
127 | #include <trace/events/kmem.h> |
128 | |
129 | #include "internal.h" |
130 | |
131 | #include "slab.h" |
132 | |
133 | /* |
134 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. |
135 | * 0 for faster, smaller code (especially in the critical paths). |
136 | * |
137 | * STATS - 1 to collect stats for /proc/slabinfo. |
138 | * 0 for faster, smaller code (especially in the critical paths). |
139 | * |
140 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) |
141 | */ |
142 | |
143 | #ifdef CONFIG_DEBUG_SLAB |
144 | #define DEBUG 1 |
145 | #define STATS 1 |
146 | #define FORCED_DEBUG 1 |
147 | #else |
148 | #define DEBUG 0 |
149 | #define STATS 0 |
150 | #define FORCED_DEBUG 0 |
151 | #endif |
152 | |
153 | /* Shouldn't this be in a header file somewhere? */ |
154 | #define BYTES_PER_WORD sizeof(void *) |
155 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) |
156 | |
157 | #ifndef ARCH_KMALLOC_FLAGS |
158 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN |
159 | #endif |
160 | |
161 | #define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \ |
162 | <= SLAB_OBJ_MIN_SIZE) ? 1 : 0) |
163 | |
164 | #if FREELIST_BYTE_INDEX |
165 | typedef unsigned char freelist_idx_t; |
166 | #else |
167 | typedef unsigned short freelist_idx_t; |
168 | #endif |
169 | |
170 | #define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1) |
171 | |
172 | /* |
173 | * struct array_cache |
174 | * |
175 | * Purpose: |
176 | * - LIFO ordering, to hand out cache-warm objects from _alloc |
177 | * - reduce the number of linked list operations |
178 | * - reduce spinlock operations |
179 | * |
180 | * The limit is stored in the per-cpu structure to reduce the data cache |
181 | * footprint. |
182 | * |
183 | */ |
184 | struct array_cache { |
185 | unsigned int avail; |
186 | unsigned int limit; |
187 | unsigned int batchcount; |
188 | unsigned int touched; |
189 | void *entry[]; /* |
190 | * Must have this definition in here for the proper |
191 | * alignment of array_cache. Also simplifies accessing |
192 | * the entries. |
193 | */ |
194 | }; |
195 | |
196 | struct alien_cache { |
197 | spinlock_t lock; |
198 | struct array_cache ac; |
199 | }; |
200 | |
201 | /* |
202 | * Need this for bootstrapping a per node allocator. |
203 | */ |
204 | #define NUM_INIT_LISTS (2 * MAX_NUMNODES) |
205 | static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; |
206 | #define CACHE_CACHE 0 |
207 | #define SIZE_NODE (MAX_NUMNODES) |
208 | |
209 | static int drain_freelist(struct kmem_cache *cache, |
210 | struct kmem_cache_node *n, int tofree); |
211 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, |
212 | int node, struct list_head *list); |
213 | static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list); |
214 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); |
215 | static void cache_reap(struct work_struct *unused); |
216 | |
217 | static inline void fixup_objfreelist_debug(struct kmem_cache *cachep, |
218 | void **list); |
219 | static inline void fixup_slab_list(struct kmem_cache *cachep, |
220 | struct kmem_cache_node *n, struct page *page, |
221 | void **list); |
222 | static int slab_early_init = 1; |
223 | |
224 | #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) |
225 | |
226 | static void kmem_cache_node_init(struct kmem_cache_node *parent) |
227 | { |
228 | INIT_LIST_HEAD(&parent->slabs_full); |
229 | INIT_LIST_HEAD(&parent->slabs_partial); |
230 | INIT_LIST_HEAD(&parent->slabs_free); |
231 | parent->total_slabs = 0; |
232 | parent->free_slabs = 0; |
233 | parent->shared = NULL; |
234 | parent->alien = NULL; |
235 | parent->colour_next = 0; |
236 | spin_lock_init(&parent->list_lock); |
237 | parent->free_objects = 0; |
238 | parent->free_touched = 0; |
239 | } |
240 | |
241 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ |
242 | do { \ |
243 | INIT_LIST_HEAD(listp); \ |
244 | list_splice(&get_node(cachep, nodeid)->slab, listp); \ |
245 | } while (0) |
246 | |
247 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ |
248 | do { \ |
249 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ |
250 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ |
251 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ |
252 | } while (0) |
253 | |
254 | #define CFLGS_OBJFREELIST_SLAB ((slab_flags_t __force)0x40000000U) |
255 | #define CFLGS_OFF_SLAB ((slab_flags_t __force)0x80000000U) |
256 | #define OBJFREELIST_SLAB(x) ((x)->flags & CFLGS_OBJFREELIST_SLAB) |
257 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) |
258 | |
259 | #define BATCHREFILL_LIMIT 16 |
260 | /* |
261 | * Optimization question: fewer reaps means less probability for unnessary |
262 | * cpucache drain/refill cycles. |
263 | * |
264 | * OTOH the cpuarrays can contain lots of objects, |
265 | * which could lock up otherwise freeable slabs. |
266 | */ |
267 | #define REAPTIMEOUT_AC (2*HZ) |
268 | #define REAPTIMEOUT_NODE (4*HZ) |
269 | |
270 | #if STATS |
271 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) |
272 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) |
273 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) |
274 | #define STATS_INC_GROWN(x) ((x)->grown++) |
275 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) |
276 | #define STATS_SET_HIGH(x) \ |
277 | do { \ |
278 | if ((x)->num_active > (x)->high_mark) \ |
279 | (x)->high_mark = (x)->num_active; \ |
280 | } while (0) |
281 | #define STATS_INC_ERR(x) ((x)->errors++) |
282 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) |
283 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) |
284 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) |
285 | #define STATS_SET_FREEABLE(x, i) \ |
286 | do { \ |
287 | if ((x)->max_freeable < i) \ |
288 | (x)->max_freeable = i; \ |
289 | } while (0) |
290 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) |
291 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) |
292 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) |
293 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) |
294 | #else |
295 | #define STATS_INC_ACTIVE(x) do { } while (0) |
296 | #define STATS_DEC_ACTIVE(x) do { } while (0) |
297 | #define STATS_INC_ALLOCED(x) do { } while (0) |
298 | #define STATS_INC_GROWN(x) do { } while (0) |
299 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) |
300 | #define STATS_SET_HIGH(x) do { } while (0) |
301 | #define STATS_INC_ERR(x) do { } while (0) |
302 | #define STATS_INC_NODEALLOCS(x) do { } while (0) |
303 | #define STATS_INC_NODEFREES(x) do { } while (0) |
304 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) |
305 | #define STATS_SET_FREEABLE(x, i) do { } while (0) |
306 | #define STATS_INC_ALLOCHIT(x) do { } while (0) |
307 | #define STATS_INC_ALLOCMISS(x) do { } while (0) |
308 | #define STATS_INC_FREEHIT(x) do { } while (0) |
309 | #define STATS_INC_FREEMISS(x) do { } while (0) |
310 | #endif |
311 | |
312 | #if DEBUG |
313 | |
314 | /* |
315 | * memory layout of objects: |
316 | * 0 : objp |
317 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that |
318 | * the end of an object is aligned with the end of the real |
319 | * allocation. Catches writes behind the end of the allocation. |
320 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: |
321 | * redzone word. |
322 | * cachep->obj_offset: The real object. |
323 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] |
324 | * cachep->size - 1* BYTES_PER_WORD: last caller address |
325 | * [BYTES_PER_WORD long] |
326 | */ |
327 | static int obj_offset(struct kmem_cache *cachep) |
328 | { |
329 | return cachep->obj_offset; |
330 | } |
331 | |
332 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) |
333 | { |
334 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
335 | return (unsigned long long*) (objp + obj_offset(cachep) - |
336 | sizeof(unsigned long long)); |
337 | } |
338 | |
339 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) |
340 | { |
341 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); |
342 | if (cachep->flags & SLAB_STORE_USER) |
343 | return (unsigned long long *)(objp + cachep->size - |
344 | sizeof(unsigned long long) - |
345 | REDZONE_ALIGN); |
346 | return (unsigned long long *) (objp + cachep->size - |
347 | sizeof(unsigned long long)); |
348 | } |
349 | |
350 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) |
351 | { |
352 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); |
353 | return (void **)(objp + cachep->size - BYTES_PER_WORD); |
354 | } |
355 | |
356 | #else |
357 | |
358 | #define obj_offset(x) 0 |
359 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
360 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) |
361 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) |
362 | |
363 | #endif |
364 | |
365 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
366 | |
367 | static inline bool is_store_user_clean(struct kmem_cache *cachep) |
368 | { |
369 | return atomic_read(&cachep->store_user_clean) == 1; |
370 | } |
371 | |
372 | static inline void set_store_user_clean(struct kmem_cache *cachep) |
373 | { |
374 | atomic_set(&cachep->store_user_clean, 1); |
375 | } |
376 | |
377 | static inline void set_store_user_dirty(struct kmem_cache *cachep) |
378 | { |
379 | if (is_store_user_clean(cachep)) |
380 | atomic_set(&cachep->store_user_clean, 0); |
381 | } |
382 | |
383 | #else |
384 | static inline void set_store_user_dirty(struct kmem_cache *cachep) {} |
385 | |
386 | #endif |
387 | |
388 | /* |
389 | * Do not go above this order unless 0 objects fit into the slab or |
390 | * overridden on the command line. |
391 | */ |
392 | #define SLAB_MAX_ORDER_HI 1 |
393 | #define SLAB_MAX_ORDER_LO 0 |
394 | static int slab_max_order = SLAB_MAX_ORDER_LO; |
395 | static bool slab_max_order_set __initdata; |
396 | |
397 | static inline struct kmem_cache *virt_to_cache(const void *obj) |
398 | { |
399 | struct page *page = virt_to_head_page(obj); |
400 | return page->slab_cache; |
401 | } |
402 | |
403 | static inline void *index_to_obj(struct kmem_cache *cache, struct page *page, |
404 | unsigned int idx) |
405 | { |
406 | return page->s_mem + cache->size * idx; |
407 | } |
408 | |
409 | #define BOOT_CPUCACHE_ENTRIES 1 |
410 | /* internal cache of cache description objs */ |
411 | static struct kmem_cache kmem_cache_boot = { |
412 | .batchcount = 1, |
413 | .limit = BOOT_CPUCACHE_ENTRIES, |
414 | .shared = 1, |
415 | .size = sizeof(struct kmem_cache), |
416 | .name = "kmem_cache", |
417 | }; |
418 | |
419 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); |
420 | |
421 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) |
422 | { |
423 | return this_cpu_ptr(cachep->cpu_cache); |
424 | } |
425 | |
426 | /* |
427 | * Calculate the number of objects and left-over bytes for a given buffer size. |
428 | */ |
429 | static unsigned int cache_estimate(unsigned long gfporder, size_t buffer_size, |
430 | slab_flags_t flags, size_t *left_over) |
431 | { |
432 | unsigned int num; |
433 | size_t slab_size = PAGE_SIZE << gfporder; |
434 | |
435 | /* |
436 | * The slab management structure can be either off the slab or |
437 | * on it. For the latter case, the memory allocated for a |
438 | * slab is used for: |
439 | * |
440 | * - @buffer_size bytes for each object |
441 | * - One freelist_idx_t for each object |
442 | * |
443 | * We don't need to consider alignment of freelist because |
444 | * freelist will be at the end of slab page. The objects will be |
445 | * at the correct alignment. |
446 | * |
447 | * If the slab management structure is off the slab, then the |
448 | * alignment will already be calculated into the size. Because |
449 | * the slabs are all pages aligned, the objects will be at the |
450 | * correct alignment when allocated. |
451 | */ |
452 | if (flags & (CFLGS_OBJFREELIST_SLAB | CFLGS_OFF_SLAB)) { |
453 | num = slab_size / buffer_size; |
454 | *left_over = slab_size % buffer_size; |
455 | } else { |
456 | num = slab_size / (buffer_size + sizeof(freelist_idx_t)); |
457 | *left_over = slab_size % |
458 | (buffer_size + sizeof(freelist_idx_t)); |
459 | } |
460 | |
461 | return num; |
462 | } |
463 | |
464 | #if DEBUG |
465 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) |
466 | |
467 | static void __slab_error(const char *function, struct kmem_cache *cachep, |
468 | char *msg) |
469 | { |
470 | pr_err("slab error in %s(): cache `%s': %s\n", |
471 | function, cachep->name, msg); |
472 | dump_stack(); |
473 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); |
474 | } |
475 | #endif |
476 | |
477 | /* |
478 | * By default on NUMA we use alien caches to stage the freeing of |
479 | * objects allocated from other nodes. This causes massive memory |
480 | * inefficiencies when using fake NUMA setup to split memory into a |
481 | * large number of small nodes, so it can be disabled on the command |
482 | * line |
483 | */ |
484 | |
485 | static int use_alien_caches __read_mostly = 1; |
486 | static int __init noaliencache_setup(char *s) |
487 | { |
488 | use_alien_caches = 0; |
489 | return 1; |
490 | } |
491 | __setup("noaliencache", noaliencache_setup); |
492 | |
493 | static int __init slab_max_order_setup(char *str) |
494 | { |
495 | get_option(&str, &slab_max_order); |
496 | slab_max_order = slab_max_order < 0 ? 0 : |
497 | min(slab_max_order, MAX_ORDER - 1); |
498 | slab_max_order_set = true; |
499 | |
500 | return 1; |
501 | } |
502 | __setup("slab_max_order=", slab_max_order_setup); |
503 | |
504 | #ifdef CONFIG_NUMA |
505 | /* |
506 | * Special reaping functions for NUMA systems called from cache_reap(). |
507 | * These take care of doing round robin flushing of alien caches (containing |
508 | * objects freed on different nodes from which they were allocated) and the |
509 | * flushing of remote pcps by calling drain_node_pages. |
510 | */ |
511 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); |
512 | |
513 | static void init_reap_node(int cpu) |
514 | { |
515 | per_cpu(slab_reap_node, cpu) = next_node_in(cpu_to_mem(cpu), |
516 | node_online_map); |
517 | } |
518 | |
519 | static void next_reap_node(void) |
520 | { |
521 | int node = __this_cpu_read(slab_reap_node); |
522 | |
523 | node = next_node_in(node, node_online_map); |
524 | __this_cpu_write(slab_reap_node, node); |
525 | } |
526 | |
527 | #else |
528 | #define init_reap_node(cpu) do { } while (0) |
529 | #define next_reap_node(void) do { } while (0) |
530 | #endif |
531 | |
532 | /* |
533 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz |
534 | * via the workqueue/eventd. |
535 | * Add the CPU number into the expiration time to minimize the possibility of |
536 | * the CPUs getting into lockstep and contending for the global cache chain |
537 | * lock. |
538 | */ |
539 | static void start_cpu_timer(int cpu) |
540 | { |
541 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); |
542 | |
543 | if (reap_work->work.func == NULL) { |
544 | init_reap_node(cpu); |
545 | INIT_DEFERRABLE_WORK(reap_work, cache_reap); |
546 | schedule_delayed_work_on(cpu, reap_work, |
547 | __round_jiffies_relative(HZ, cpu)); |
548 | } |
549 | } |
550 | |
551 | static void init_arraycache(struct array_cache *ac, int limit, int batch) |
552 | { |
553 | if (ac) { |
554 | ac->avail = 0; |
555 | ac->limit = limit; |
556 | ac->batchcount = batch; |
557 | ac->touched = 0; |
558 | } |
559 | } |
560 | |
561 | static struct array_cache *alloc_arraycache(int node, int entries, |
562 | int batchcount, gfp_t gfp) |
563 | { |
564 | size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache); |
565 | struct array_cache *ac = NULL; |
566 | |
567 | ac = kmalloc_node(memsize, gfp, node); |
568 | /* |
569 | * The array_cache structures contain pointers to free object. |
570 | * However, when such objects are allocated or transferred to another |
571 | * cache the pointers are not cleared and they could be counted as |
572 | * valid references during a kmemleak scan. Therefore, kmemleak must |
573 | * not scan such objects. |
574 | */ |
575 | kmemleak_no_scan(ac); |
576 | init_arraycache(ac, entries, batchcount); |
577 | return ac; |
578 | } |
579 | |
580 | static noinline void cache_free_pfmemalloc(struct kmem_cache *cachep, |
581 | struct page *page, void *objp) |
582 | { |
583 | struct kmem_cache_node *n; |
584 | int page_node; |
585 | LIST_HEAD(list); |
586 | |
587 | page_node = page_to_nid(page); |
588 | n = get_node(cachep, page_node); |
589 | |
590 | spin_lock(&n->list_lock); |
591 | free_block(cachep, &objp, 1, page_node, &list); |
592 | spin_unlock(&n->list_lock); |
593 | |
594 | slabs_destroy(cachep, &list); |
595 | } |
596 | |
597 | /* |
598 | * Transfer objects in one arraycache to another. |
599 | * Locking must be handled by the caller. |
600 | * |
601 | * Return the number of entries transferred. |
602 | */ |
603 | static int transfer_objects(struct array_cache *to, |
604 | struct array_cache *from, unsigned int max) |
605 | { |
606 | /* Figure out how many entries to transfer */ |
607 | int nr = min3(from->avail, max, to->limit - to->avail); |
608 | |
609 | if (!nr) |
610 | return 0; |
611 | |
612 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, |
613 | sizeof(void *) *nr); |
614 | |
615 | from->avail -= nr; |
616 | to->avail += nr; |
617 | return nr; |
618 | } |
619 | |
620 | #ifndef CONFIG_NUMA |
621 | |
622 | #define drain_alien_cache(cachep, alien) do { } while (0) |
623 | #define reap_alien(cachep, n) do { } while (0) |
624 | |
625 | static inline struct alien_cache **alloc_alien_cache(int node, |
626 | int limit, gfp_t gfp) |
627 | { |
628 | return NULL; |
629 | } |
630 | |
631 | static inline void free_alien_cache(struct alien_cache **ac_ptr) |
632 | { |
633 | } |
634 | |
635 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
636 | { |
637 | return 0; |
638 | } |
639 | |
640 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, |
641 | gfp_t flags) |
642 | { |
643 | return NULL; |
644 | } |
645 | |
646 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, |
647 | gfp_t flags, int nodeid) |
648 | { |
649 | return NULL; |
650 | } |
651 | |
652 | static inline gfp_t gfp_exact_node(gfp_t flags) |
653 | { |
654 | return flags & ~__GFP_NOFAIL; |
655 | } |
656 | |
657 | #else /* CONFIG_NUMA */ |
658 | |
659 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); |
660 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); |
661 | |
662 | static struct alien_cache *__alloc_alien_cache(int node, int entries, |
663 | int batch, gfp_t gfp) |
664 | { |
665 | size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache); |
666 | struct alien_cache *alc = NULL; |
667 | |
668 | alc = kmalloc_node(memsize, gfp, node); |
669 | if (alc) { |
670 | kmemleak_no_scan(alc); |
671 | init_arraycache(&alc->ac, entries, batch); |
672 | spin_lock_init(&alc->lock); |
673 | } |
674 | return alc; |
675 | } |
676 | |
677 | static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) |
678 | { |
679 | struct alien_cache **alc_ptr; |
680 | int i; |
681 | |
682 | if (limit > 1) |
683 | limit = 12; |
684 | alc_ptr = kcalloc_node(nr_node_ids, sizeof(void *), gfp, node); |
685 | if (!alc_ptr) |
686 | return NULL; |
687 | |
688 | for_each_node(i) { |
689 | if (i == node || !node_online(i)) |
690 | continue; |
691 | alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp); |
692 | if (!alc_ptr[i]) { |
693 | for (i--; i >= 0; i--) |
694 | kfree(alc_ptr[i]); |
695 | kfree(alc_ptr); |
696 | return NULL; |
697 | } |
698 | } |
699 | return alc_ptr; |
700 | } |
701 | |
702 | static void free_alien_cache(struct alien_cache **alc_ptr) |
703 | { |
704 | int i; |
705 | |
706 | if (!alc_ptr) |
707 | return; |
708 | for_each_node(i) |
709 | kfree(alc_ptr[i]); |
710 | kfree(alc_ptr); |
711 | } |
712 | |
713 | static void __drain_alien_cache(struct kmem_cache *cachep, |
714 | struct array_cache *ac, int node, |
715 | struct list_head *list) |
716 | { |
717 | struct kmem_cache_node *n = get_node(cachep, node); |
718 | |
719 | if (ac->avail) { |
720 | spin_lock(&n->list_lock); |
721 | /* |
722 | * Stuff objects into the remote nodes shared array first. |
723 | * That way we could avoid the overhead of putting the objects |
724 | * into the free lists and getting them back later. |
725 | */ |
726 | if (n->shared) |
727 | transfer_objects(n->shared, ac, ac->limit); |
728 | |
729 | free_block(cachep, ac->entry, ac->avail, node, list); |
730 | ac->avail = 0; |
731 | spin_unlock(&n->list_lock); |
732 | } |
733 | } |
734 | |
735 | /* |
736 | * Called from cache_reap() to regularly drain alien caches round robin. |
737 | */ |
738 | static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) |
739 | { |
740 | int node = __this_cpu_read(slab_reap_node); |
741 | |
742 | if (n->alien) { |
743 | struct alien_cache *alc = n->alien[node]; |
744 | struct array_cache *ac; |
745 | |
746 | if (alc) { |
747 | ac = &alc->ac; |
748 | if (ac->avail && spin_trylock_irq(&alc->lock)) { |
749 | LIST_HEAD(list); |
750 | |
751 | __drain_alien_cache(cachep, ac, node, &list); |
752 | spin_unlock_irq(&alc->lock); |
753 | slabs_destroy(cachep, &list); |
754 | } |
755 | } |
756 | } |
757 | } |
758 | |
759 | static void drain_alien_cache(struct kmem_cache *cachep, |
760 | struct alien_cache **alien) |
761 | { |
762 | int i = 0; |
763 | struct alien_cache *alc; |
764 | struct array_cache *ac; |
765 | unsigned long flags; |
766 | |
767 | for_each_online_node(i) { |
768 | alc = alien[i]; |
769 | if (alc) { |
770 | LIST_HEAD(list); |
771 | |
772 | ac = &alc->ac; |
773 | spin_lock_irqsave(&alc->lock, flags); |
774 | __drain_alien_cache(cachep, ac, i, &list); |
775 | spin_unlock_irqrestore(&alc->lock, flags); |
776 | slabs_destroy(cachep, &list); |
777 | } |
778 | } |
779 | } |
780 | |
781 | static int __cache_free_alien(struct kmem_cache *cachep, void *objp, |
782 | int node, int page_node) |
783 | { |
784 | struct kmem_cache_node *n; |
785 | struct alien_cache *alien = NULL; |
786 | struct array_cache *ac; |
787 | LIST_HEAD(list); |
788 | |
789 | n = get_node(cachep, node); |
790 | STATS_INC_NODEFREES(cachep); |
791 | if (n->alien && n->alien[page_node]) { |
792 | alien = n->alien[page_node]; |
793 | ac = &alien->ac; |
794 | spin_lock(&alien->lock); |
795 | if (unlikely(ac->avail == ac->limit)) { |
796 | STATS_INC_ACOVERFLOW(cachep); |
797 | __drain_alien_cache(cachep, ac, page_node, &list); |
798 | } |
799 | ac->entry[ac->avail++] = objp; |
800 | spin_unlock(&alien->lock); |
801 | slabs_destroy(cachep, &list); |
802 | } else { |
803 | n = get_node(cachep, page_node); |
804 | spin_lock(&n->list_lock); |
805 | free_block(cachep, &objp, 1, page_node, &list); |
806 | spin_unlock(&n->list_lock); |
807 | slabs_destroy(cachep, &list); |
808 | } |
809 | return 1; |
810 | } |
811 | |
812 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) |
813 | { |
814 | int page_node = page_to_nid(virt_to_page(objp)); |
815 | int node = numa_mem_id(); |
816 | /* |
817 | * Make sure we are not freeing a object from another node to the array |
818 | * cache on this cpu. |
819 | */ |
820 | if (likely(node == page_node)) |
821 | return 0; |
822 | |
823 | return __cache_free_alien(cachep, objp, node, page_node); |
824 | } |
825 | |
826 | /* |
827 | * Construct gfp mask to allocate from a specific node but do not reclaim or |
828 | * warn about failures. |
829 | */ |
830 | static inline gfp_t gfp_exact_node(gfp_t flags) |
831 | { |
832 | return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~(__GFP_RECLAIM|__GFP_NOFAIL); |
833 | } |
834 | #endif |
835 | |
836 | static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp) |
837 | { |
838 | struct kmem_cache_node *n; |
839 | |
840 | /* |
841 | * Set up the kmem_cache_node for cpu before we can |
842 | * begin anything. Make sure some other cpu on this |
843 | * node has not already allocated this |
844 | */ |
845 | n = get_node(cachep, node); |
846 | if (n) { |
847 | spin_lock_irq(&n->list_lock); |
848 | n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount + |
849 | cachep->num; |
850 | spin_unlock_irq(&n->list_lock); |
851 | |
852 | return 0; |
853 | } |
854 | |
855 | n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); |
856 | if (!n) |
857 | return -ENOMEM; |
858 | |
859 | kmem_cache_node_init(n); |
860 | n->next_reap = jiffies + REAPTIMEOUT_NODE + |
861 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
862 | |
863 | n->free_limit = |
864 | (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num; |
865 | |
866 | /* |
867 | * The kmem_cache_nodes don't come and go as CPUs |
868 | * come and go. slab_mutex is sufficient |
869 | * protection here. |
870 | */ |
871 | cachep->node[node] = n; |
872 | |
873 | return 0; |
874 | } |
875 | |
876 | #if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP) |
877 | /* |
878 | * Allocates and initializes node for a node on each slab cache, used for |
879 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node |
880 | * will be allocated off-node since memory is not yet online for the new node. |
881 | * When hotplugging memory or a cpu, existing node are not replaced if |
882 | * already in use. |
883 | * |
884 | * Must hold slab_mutex. |
885 | */ |
886 | static int init_cache_node_node(int node) |
887 | { |
888 | int ret; |
889 | struct kmem_cache *cachep; |
890 | |
891 | list_for_each_entry(cachep, &slab_caches, list) { |
892 | ret = init_cache_node(cachep, node, GFP_KERNEL); |
893 | if (ret) |
894 | return ret; |
895 | } |
896 | |
897 | return 0; |
898 | } |
899 | #endif |
900 | |
901 | static int setup_kmem_cache_node(struct kmem_cache *cachep, |
902 | int node, gfp_t gfp, bool force_change) |
903 | { |
904 | int ret = -ENOMEM; |
905 | struct kmem_cache_node *n; |
906 | struct array_cache *old_shared = NULL; |
907 | struct array_cache *new_shared = NULL; |
908 | struct alien_cache **new_alien = NULL; |
909 | LIST_HEAD(list); |
910 | |
911 | if (use_alien_caches) { |
912 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); |
913 | if (!new_alien) |
914 | goto fail; |
915 | } |
916 | |
917 | if (cachep->shared) { |
918 | new_shared = alloc_arraycache(node, |
919 | cachep->shared * cachep->batchcount, 0xbaadf00d, gfp); |
920 | if (!new_shared) |
921 | goto fail; |
922 | } |
923 | |
924 | ret = init_cache_node(cachep, node, gfp); |
925 | if (ret) |
926 | goto fail; |
927 | |
928 | n = get_node(cachep, node); |
929 | spin_lock_irq(&n->list_lock); |
930 | if (n->shared && force_change) { |
931 | free_block(cachep, n->shared->entry, |
932 | n->shared->avail, node, &list); |
933 | n->shared->avail = 0; |
934 | } |
935 | |
936 | if (!n->shared || force_change) { |
937 | old_shared = n->shared; |
938 | n->shared = new_shared; |
939 | new_shared = NULL; |
940 | } |
941 | |
942 | if (!n->alien) { |
943 | n->alien = new_alien; |
944 | new_alien = NULL; |
945 | } |
946 | |
947 | spin_unlock_irq(&n->list_lock); |
948 | slabs_destroy(cachep, &list); |
949 | |
950 | /* |
951 | * To protect lockless access to n->shared during irq disabled context. |
952 | * If n->shared isn't NULL in irq disabled context, accessing to it is |
953 | * guaranteed to be valid until irq is re-enabled, because it will be |
954 | * freed after synchronize_rcu(). |
955 | */ |
956 | if (old_shared && force_change) |
957 | synchronize_rcu(); |
958 | |
959 | fail: |
960 | kfree(old_shared); |
961 | kfree(new_shared); |
962 | free_alien_cache(new_alien); |
963 | |
964 | return ret; |
965 | } |
966 | |
967 | #ifdef CONFIG_SMP |
968 | |
969 | static void cpuup_canceled(long cpu) |
970 | { |
971 | struct kmem_cache *cachep; |
972 | struct kmem_cache_node *n = NULL; |
973 | int node = cpu_to_mem(cpu); |
974 | const struct cpumask *mask = cpumask_of_node(node); |
975 | |
976 | list_for_each_entry(cachep, &slab_caches, list) { |
977 | struct array_cache *nc; |
978 | struct array_cache *shared; |
979 | struct alien_cache **alien; |
980 | LIST_HEAD(list); |
981 | |
982 | n = get_node(cachep, node); |
983 | if (!n) |
984 | continue; |
985 | |
986 | spin_lock_irq(&n->list_lock); |
987 | |
988 | /* Free limit for this kmem_cache_node */ |
989 | n->free_limit -= cachep->batchcount; |
990 | |
991 | /* cpu is dead; no one can alloc from it. */ |
992 | nc = per_cpu_ptr(cachep->cpu_cache, cpu); |
993 | if (nc) { |
994 | free_block(cachep, nc->entry, nc->avail, node, &list); |
995 | nc->avail = 0; |
996 | } |
997 | |
998 | if (!cpumask_empty(mask)) { |
999 | spin_unlock_irq(&n->list_lock); |
1000 | goto free_slab; |
1001 | } |
1002 | |
1003 | shared = n->shared; |
1004 | if (shared) { |
1005 | free_block(cachep, shared->entry, |
1006 | shared->avail, node, &list); |
1007 | n->shared = NULL; |
1008 | } |
1009 | |
1010 | alien = n->alien; |
1011 | n->alien = NULL; |
1012 | |
1013 | spin_unlock_irq(&n->list_lock); |
1014 | |
1015 | kfree(shared); |
1016 | if (alien) { |
1017 | drain_alien_cache(cachep, alien); |
1018 | free_alien_cache(alien); |
1019 | } |
1020 | |
1021 | free_slab: |
1022 | slabs_destroy(cachep, &list); |
1023 | } |
1024 | /* |
1025 | * In the previous loop, all the objects were freed to |
1026 | * the respective cache's slabs, now we can go ahead and |
1027 | * shrink each nodelist to its limit. |
1028 | */ |
1029 | list_for_each_entry(cachep, &slab_caches, list) { |
1030 | n = get_node(cachep, node); |
1031 | if (!n) |
1032 | continue; |
1033 | drain_freelist(cachep, n, INT_MAX); |
1034 | } |
1035 | } |
1036 | |
1037 | static int cpuup_prepare(long cpu) |
1038 | { |
1039 | struct kmem_cache *cachep; |
1040 | int node = cpu_to_mem(cpu); |
1041 | int err; |
1042 | |
1043 | /* |
1044 | * We need to do this right in the beginning since |
1045 | * alloc_arraycache's are going to use this list. |
1046 | * kmalloc_node allows us to add the slab to the right |
1047 | * kmem_cache_node and not this cpu's kmem_cache_node |
1048 | */ |
1049 | err = init_cache_node_node(node); |
1050 | if (err < 0) |
1051 | goto bad; |
1052 | |
1053 | /* |
1054 | * Now we can go ahead with allocating the shared arrays and |
1055 | * array caches |
1056 | */ |
1057 | list_for_each_entry(cachep, &slab_caches, list) { |
1058 | err = setup_kmem_cache_node(cachep, node, GFP_KERNEL, false); |
1059 | if (err) |
1060 | goto bad; |
1061 | } |
1062 | |
1063 | return 0; |
1064 | bad: |
1065 | cpuup_canceled(cpu); |
1066 | return -ENOMEM; |
1067 | } |
1068 | |
1069 | int slab_prepare_cpu(unsigned int cpu) |
1070 | { |
1071 | int err; |
1072 | |
1073 | mutex_lock(&slab_mutex); |
1074 | err = cpuup_prepare(cpu); |
1075 | mutex_unlock(&slab_mutex); |
1076 | return err; |
1077 | } |
1078 | |
1079 | /* |
1080 | * This is called for a failed online attempt and for a successful |
1081 | * offline. |
1082 | * |
1083 | * Even if all the cpus of a node are down, we don't free the |
1084 | * kmem_list3 of any cache. This to avoid a race between cpu_down, and |
1085 | * a kmalloc allocation from another cpu for memory from the node of |
1086 | * the cpu going down. The list3 structure is usually allocated from |
1087 | * kmem_cache_create() and gets destroyed at kmem_cache_destroy(). |
1088 | */ |
1089 | int slab_dead_cpu(unsigned int cpu) |
1090 | { |
1091 | mutex_lock(&slab_mutex); |
1092 | cpuup_canceled(cpu); |
1093 | mutex_unlock(&slab_mutex); |
1094 | return 0; |
1095 | } |
1096 | #endif |
1097 | |
1098 | static int slab_online_cpu(unsigned int cpu) |
1099 | { |
1100 | start_cpu_timer(cpu); |
1101 | return 0; |
1102 | } |
1103 | |
1104 | static int slab_offline_cpu(unsigned int cpu) |
1105 | { |
1106 | /* |
1107 | * Shutdown cache reaper. Note that the slab_mutex is held so |
1108 | * that if cache_reap() is invoked it cannot do anything |
1109 | * expensive but will only modify reap_work and reschedule the |
1110 | * timer. |
1111 | */ |
1112 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); |
1113 | /* Now the cache_reaper is guaranteed to be not running. */ |
1114 | per_cpu(slab_reap_work, cpu).work.func = NULL; |
1115 | return 0; |
1116 | } |
1117 | |
1118 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) |
1119 | /* |
1120 | * Drains freelist for a node on each slab cache, used for memory hot-remove. |
1121 | * Returns -EBUSY if all objects cannot be drained so that the node is not |
1122 | * removed. |
1123 | * |
1124 | * Must hold slab_mutex. |
1125 | */ |
1126 | static int __meminit drain_cache_node_node(int node) |
1127 | { |
1128 | struct kmem_cache *cachep; |
1129 | int ret = 0; |
1130 | |
1131 | list_for_each_entry(cachep, &slab_caches, list) { |
1132 | struct kmem_cache_node *n; |
1133 | |
1134 | n = get_node(cachep, node); |
1135 | if (!n) |
1136 | continue; |
1137 | |
1138 | drain_freelist(cachep, n, INT_MAX); |
1139 | |
1140 | if (!list_empty(&n->slabs_full) || |
1141 | !list_empty(&n->slabs_partial)) { |
1142 | ret = -EBUSY; |
1143 | break; |
1144 | } |
1145 | } |
1146 | return ret; |
1147 | } |
1148 | |
1149 | static int __meminit slab_memory_callback(struct notifier_block *self, |
1150 | unsigned long action, void *arg) |
1151 | { |
1152 | struct memory_notify *mnb = arg; |
1153 | int ret = 0; |
1154 | int nid; |
1155 | |
1156 | nid = mnb->status_change_nid; |
1157 | if (nid < 0) |
1158 | goto out; |
1159 | |
1160 | switch (action) { |
1161 | case MEM_GOING_ONLINE: |
1162 | mutex_lock(&slab_mutex); |
1163 | ret = init_cache_node_node(nid); |
1164 | mutex_unlock(&slab_mutex); |
1165 | break; |
1166 | case MEM_GOING_OFFLINE: |
1167 | mutex_lock(&slab_mutex); |
1168 | ret = drain_cache_node_node(nid); |
1169 | mutex_unlock(&slab_mutex); |
1170 | break; |
1171 | case MEM_ONLINE: |
1172 | case MEM_OFFLINE: |
1173 | case MEM_CANCEL_ONLINE: |
1174 | case MEM_CANCEL_OFFLINE: |
1175 | break; |
1176 | } |
1177 | out: |
1178 | return notifier_from_errno(ret); |
1179 | } |
1180 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ |
1181 | |
1182 | /* |
1183 | * swap the static kmem_cache_node with kmalloced memory |
1184 | */ |
1185 | static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, |
1186 | int nodeid) |
1187 | { |
1188 | struct kmem_cache_node *ptr; |
1189 | |
1190 | ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); |
1191 | BUG_ON(!ptr); |
1192 | |
1193 | memcpy(ptr, list, sizeof(struct kmem_cache_node)); |
1194 | /* |
1195 | * Do not assume that spinlocks can be initialized via memcpy: |
1196 | */ |
1197 | spin_lock_init(&ptr->list_lock); |
1198 | |
1199 | MAKE_ALL_LISTS(cachep, ptr, nodeid); |
1200 | cachep->node[nodeid] = ptr; |
1201 | } |
1202 | |
1203 | /* |
1204 | * For setting up all the kmem_cache_node for cache whose buffer_size is same as |
1205 | * size of kmem_cache_node. |
1206 | */ |
1207 | static void __init set_up_node(struct kmem_cache *cachep, int index) |
1208 | { |
1209 | int node; |
1210 | |
1211 | for_each_online_node(node) { |
1212 | cachep->node[node] = &init_kmem_cache_node[index + node]; |
1213 | cachep->node[node]->next_reap = jiffies + |
1214 | REAPTIMEOUT_NODE + |
1215 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
1216 | } |
1217 | } |
1218 | |
1219 | /* |
1220 | * Initialisation. Called after the page allocator have been initialised and |
1221 | * before smp_init(). |
1222 | */ |
1223 | void __init kmem_cache_init(void) |
1224 | { |
1225 | int i; |
1226 | |
1227 | kmem_cache = &kmem_cache_boot; |
1228 | |
1229 | if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1) |
1230 | use_alien_caches = 0; |
1231 | |
1232 | for (i = 0; i < NUM_INIT_LISTS; i++) |
1233 | kmem_cache_node_init(&init_kmem_cache_node[i]); |
1234 | |
1235 | /* |
1236 | * Fragmentation resistance on low memory - only use bigger |
1237 | * page orders on machines with more than 32MB of memory if |
1238 | * not overridden on the command line. |
1239 | */ |
1240 | if (!slab_max_order_set && totalram_pages() > (32 << 20) >> PAGE_SHIFT) |
1241 | slab_max_order = SLAB_MAX_ORDER_HI; |
1242 | |
1243 | /* Bootstrap is tricky, because several objects are allocated |
1244 | * from caches that do not exist yet: |
1245 | * 1) initialize the kmem_cache cache: it contains the struct |
1246 | * kmem_cache structures of all caches, except kmem_cache itself: |
1247 | * kmem_cache is statically allocated. |
1248 | * Initially an __init data area is used for the head array and the |
1249 | * kmem_cache_node structures, it's replaced with a kmalloc allocated |
1250 | * array at the end of the bootstrap. |
1251 | * 2) Create the first kmalloc cache. |
1252 | * The struct kmem_cache for the new cache is allocated normally. |
1253 | * An __init data area is used for the head array. |
1254 | * 3) Create the remaining kmalloc caches, with minimally sized |
1255 | * head arrays. |
1256 | * 4) Replace the __init data head arrays for kmem_cache and the first |
1257 | * kmalloc cache with kmalloc allocated arrays. |
1258 | * 5) Replace the __init data for kmem_cache_node for kmem_cache and |
1259 | * the other cache's with kmalloc allocated memory. |
1260 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. |
1261 | */ |
1262 | |
1263 | /* 1) create the kmem_cache */ |
1264 | |
1265 | /* |
1266 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids |
1267 | */ |
1268 | create_boot_cache(kmem_cache, "kmem_cache", |
1269 | offsetof(struct kmem_cache, node) + |
1270 | nr_node_ids * sizeof(struct kmem_cache_node *), |
1271 | SLAB_HWCACHE_ALIGN, 0, 0); |
1272 | list_add(&kmem_cache->list, &slab_caches); |
1273 | memcg_link_cache(kmem_cache); |
1274 | slab_state = PARTIAL; |
1275 | |
1276 | /* |
1277 | * Initialize the caches that provide memory for the kmem_cache_node |
1278 | * structures first. Without this, further allocations will bug. |
1279 | */ |
1280 | kmalloc_caches[KMALLOC_NORMAL][INDEX_NODE] = create_kmalloc_cache( |
1281 | kmalloc_info[INDEX_NODE].name, |
1282 | kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS, |
1283 | 0, kmalloc_size(INDEX_NODE)); |
1284 | slab_state = PARTIAL_NODE; |
1285 | setup_kmalloc_cache_index_table(); |
1286 | |
1287 | slab_early_init = 0; |
1288 | |
1289 | /* 5) Replace the bootstrap kmem_cache_node */ |
1290 | { |
1291 | int nid; |
1292 | |
1293 | for_each_online_node(nid) { |
1294 | init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); |
1295 | |
1296 | init_list(kmalloc_caches[KMALLOC_NORMAL][INDEX_NODE], |
1297 | &init_kmem_cache_node[SIZE_NODE + nid], nid); |
1298 | } |
1299 | } |
1300 | |
1301 | create_kmalloc_caches(ARCH_KMALLOC_FLAGS); |
1302 | } |
1303 | |
1304 | void __init kmem_cache_init_late(void) |
1305 | { |
1306 | struct kmem_cache *cachep; |
1307 | |
1308 | /* 6) resize the head arrays to their final sizes */ |
1309 | mutex_lock(&slab_mutex); |
1310 | list_for_each_entry(cachep, &slab_caches, list) |
1311 | if (enable_cpucache(cachep, GFP_NOWAIT)) |
1312 | BUG(); |
1313 | mutex_unlock(&slab_mutex); |
1314 | |
1315 | /* Done! */ |
1316 | slab_state = FULL; |
1317 | |
1318 | #ifdef CONFIG_NUMA |
1319 | /* |
1320 | * Register a memory hotplug callback that initializes and frees |
1321 | * node. |
1322 | */ |
1323 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); |
1324 | #endif |
1325 | |
1326 | /* |
1327 | * The reap timers are started later, with a module init call: That part |
1328 | * of the kernel is not yet operational. |
1329 | */ |
1330 | } |
1331 | |
1332 | static int __init cpucache_init(void) |
1333 | { |
1334 | int ret; |
1335 | |
1336 | /* |
1337 | * Register the timers that return unneeded pages to the page allocator |
1338 | */ |
1339 | ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SLAB online", |
1340 | slab_online_cpu, slab_offline_cpu); |
1341 | WARN_ON(ret < 0); |
1342 | |
1343 | return 0; |
1344 | } |
1345 | __initcall(cpucache_init); |
1346 | |
1347 | static noinline void |
1348 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) |
1349 | { |
1350 | #if DEBUG |
1351 | struct kmem_cache_node *n; |
1352 | unsigned long flags; |
1353 | int node; |
1354 | static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL, |
1355 | DEFAULT_RATELIMIT_BURST); |
1356 | |
1357 | if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs)) |
1358 | return; |
1359 | |
1360 | pr_warn("SLAB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n", |
1361 | nodeid, gfpflags, &gfpflags); |
1362 | pr_warn(" cache: %s, object size: %d, order: %d\n", |
1363 | cachep->name, cachep->size, cachep->gfporder); |
1364 | |
1365 | for_each_kmem_cache_node(cachep, node, n) { |
1366 | unsigned long total_slabs, free_slabs, free_objs; |
1367 | |
1368 | spin_lock_irqsave(&n->list_lock, flags); |
1369 | total_slabs = n->total_slabs; |
1370 | free_slabs = n->free_slabs; |
1371 | free_objs = n->free_objects; |
1372 | spin_unlock_irqrestore(&n->list_lock, flags); |
1373 | |
1374 | pr_warn(" node %d: slabs: %ld/%ld, objs: %ld/%ld\n", |
1375 | node, total_slabs - free_slabs, total_slabs, |
1376 | (total_slabs * cachep->num) - free_objs, |
1377 | total_slabs * cachep->num); |
1378 | } |
1379 | #endif |
1380 | } |
1381 | |
1382 | /* |
1383 | * Interface to system's page allocator. No need to hold the |
1384 | * kmem_cache_node ->list_lock. |
1385 | * |
1386 | * If we requested dmaable memory, we will get it. Even if we |
1387 | * did not request dmaable memory, we might get it, but that |
1388 | * would be relatively rare and ignorable. |
1389 | */ |
1390 | static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, |
1391 | int nodeid) |
1392 | { |
1393 | struct page *page; |
1394 | int nr_pages; |
1395 | |
1396 | flags |= cachep->allocflags; |
1397 | |
1398 | page = __alloc_pages_node(nodeid, flags, cachep->gfporder); |
1399 | if (!page) { |
1400 | slab_out_of_memory(cachep, flags, nodeid); |
1401 | return NULL; |
1402 | } |
1403 | |
1404 | if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) { |
1405 | __free_pages(page, cachep->gfporder); |
1406 | return NULL; |
1407 | } |
1408 | |
1409 | nr_pages = (1 << cachep->gfporder); |
1410 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1411 | mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages); |
1412 | else |
1413 | mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages); |
1414 | |
1415 | __SetPageSlab(page); |
1416 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ |
1417 | if (sk_memalloc_socks() && page_is_pfmemalloc(page)) |
1418 | SetPageSlabPfmemalloc(page); |
1419 | |
1420 | return page; |
1421 | } |
1422 | |
1423 | /* |
1424 | * Interface to system's page release. |
1425 | */ |
1426 | static void kmem_freepages(struct kmem_cache *cachep, struct page *page) |
1427 | { |
1428 | int order = cachep->gfporder; |
1429 | unsigned long nr_freed = (1 << order); |
1430 | |
1431 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) |
1432 | mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed); |
1433 | else |
1434 | mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed); |
1435 | |
1436 | BUG_ON(!PageSlab(page)); |
1437 | __ClearPageSlabPfmemalloc(page); |
1438 | __ClearPageSlab(page); |
1439 | page_mapcount_reset(page); |
1440 | page->mapping = NULL; |
1441 | |
1442 | if (current->reclaim_state) |
1443 | current->reclaim_state->reclaimed_slab += nr_freed; |
1444 | memcg_uncharge_slab(page, order, cachep); |
1445 | __free_pages(page, order); |
1446 | } |
1447 | |
1448 | static void kmem_rcu_free(struct rcu_head *head) |
1449 | { |
1450 | struct kmem_cache *cachep; |
1451 | struct page *page; |
1452 | |
1453 | page = container_of(head, struct page, rcu_head); |
1454 | cachep = page->slab_cache; |
1455 | |
1456 | kmem_freepages(cachep, page); |
1457 | } |
1458 | |
1459 | #if DEBUG |
1460 | static bool is_debug_pagealloc_cache(struct kmem_cache *cachep) |
1461 | { |
1462 | if (debug_pagealloc_enabled() && OFF_SLAB(cachep) && |
1463 | (cachep->size % PAGE_SIZE) == 0) |
1464 | return true; |
1465 | |
1466 | return false; |
1467 | } |
1468 | |
1469 | #ifdef CONFIG_DEBUG_PAGEALLOC |
1470 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, |
1471 | unsigned long caller) |
1472 | { |
1473 | int size = cachep->object_size; |
1474 | |
1475 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; |
1476 | |
1477 | if (size < 5 * sizeof(unsigned long)) |
1478 | return; |
1479 | |
1480 | *addr++ = 0x12345678; |
1481 | *addr++ = caller; |
1482 | *addr++ = smp_processor_id(); |
1483 | size -= 3 * sizeof(unsigned long); |
1484 | { |
1485 | unsigned long *sptr = &caller; |
1486 | unsigned long svalue; |
1487 | |
1488 | while (!kstack_end(sptr)) { |
1489 | svalue = *sptr++; |
1490 | if (kernel_text_address(svalue)) { |
1491 | *addr++ = svalue; |
1492 | size -= sizeof(unsigned long); |
1493 | if (size <= sizeof(unsigned long)) |
1494 | break; |
1495 | } |
1496 | } |
1497 | |
1498 | } |
1499 | *addr++ = 0x87654321; |
1500 | } |
1501 | |
1502 | static void slab_kernel_map(struct kmem_cache *cachep, void *objp, |
1503 | int map, unsigned long caller) |
1504 | { |
1505 | if (!is_debug_pagealloc_cache(cachep)) |
1506 | return; |
1507 | |
1508 | if (caller) |
1509 | store_stackinfo(cachep, objp, caller); |
1510 | |
1511 | kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map); |
1512 | } |
1513 | |
1514 | #else |
1515 | static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp, |
1516 | int map, unsigned long caller) {} |
1517 | |
1518 | #endif |
1519 | |
1520 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) |
1521 | { |
1522 | int size = cachep->object_size; |
1523 | addr = &((char *)addr)[obj_offset(cachep)]; |
1524 | |
1525 | memset(addr, val, size); |
1526 | *(unsigned char *)(addr + size - 1) = POISON_END; |
1527 | } |
1528 | |
1529 | static void dump_line(char *data, int offset, int limit) |
1530 | { |
1531 | int i; |
1532 | unsigned char error = 0; |
1533 | int bad_count = 0; |
1534 | |
1535 | pr_err("%03x: ", offset); |
1536 | for (i = 0; i < limit; i++) { |
1537 | if (data[offset + i] != POISON_FREE) { |
1538 | error = data[offset + i]; |
1539 | bad_count++; |
1540 | } |
1541 | } |
1542 | print_hex_dump(KERN_CONT, "", 0, 16, 1, |
1543 | &data[offset], limit, 1); |
1544 | |
1545 | if (bad_count == 1) { |
1546 | error ^= POISON_FREE; |
1547 | if (!(error & (error - 1))) { |
1548 | pr_err("Single bit error detected. Probably bad RAM.\n"); |
1549 | #ifdef CONFIG_X86 |
1550 | pr_err("Run memtest86+ or a similar memory test tool.\n"); |
1551 | #else |
1552 | pr_err("Run a memory test tool.\n"); |
1553 | #endif |
1554 | } |
1555 | } |
1556 | } |
1557 | #endif |
1558 | |
1559 | #if DEBUG |
1560 | |
1561 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) |
1562 | { |
1563 | int i, size; |
1564 | char *realobj; |
1565 | |
1566 | if (cachep->flags & SLAB_RED_ZONE) { |
1567 | pr_err("Redzone: 0x%llx/0x%llx\n", |
1568 | *dbg_redzone1(cachep, objp), |
1569 | *dbg_redzone2(cachep, objp)); |
1570 | } |
1571 | |
1572 | if (cachep->flags & SLAB_STORE_USER) |
1573 | pr_err("Last user: (%pSR)\n", *dbg_userword(cachep, objp)); |
1574 | realobj = (char *)objp + obj_offset(cachep); |
1575 | size = cachep->object_size; |
1576 | for (i = 0; i < size && lines; i += 16, lines--) { |
1577 | int limit; |
1578 | limit = 16; |
1579 | if (i + limit > size) |
1580 | limit = size - i; |
1581 | dump_line(realobj, i, limit); |
1582 | } |
1583 | } |
1584 | |
1585 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) |
1586 | { |
1587 | char *realobj; |
1588 | int size, i; |
1589 | int lines = 0; |
1590 | |
1591 | if (is_debug_pagealloc_cache(cachep)) |
1592 | return; |
1593 | |
1594 | realobj = (char *)objp + obj_offset(cachep); |
1595 | size = cachep->object_size; |
1596 | |
1597 | for (i = 0; i < size; i++) { |
1598 | char exp = POISON_FREE; |
1599 | if (i == size - 1) |
1600 | exp = POISON_END; |
1601 | if (realobj[i] != exp) { |
1602 | int limit; |
1603 | /* Mismatch ! */ |
1604 | /* Print header */ |
1605 | if (lines == 0) { |
1606 | pr_err("Slab corruption (%s): %s start=%px, len=%d\n", |
1607 | print_tainted(), cachep->name, |
1608 | realobj, size); |
1609 | print_objinfo(cachep, objp, 0); |
1610 | } |
1611 | /* Hexdump the affected line */ |
1612 | i = (i / 16) * 16; |
1613 | limit = 16; |
1614 | if (i + limit > size) |
1615 | limit = size - i; |
1616 | dump_line(realobj, i, limit); |
1617 | i += 16; |
1618 | lines++; |
1619 | /* Limit to 5 lines */ |
1620 | if (lines > 5) |
1621 | break; |
1622 | } |
1623 | } |
1624 | if (lines != 0) { |
1625 | /* Print some data about the neighboring objects, if they |
1626 | * exist: |
1627 | */ |
1628 | struct page *page = virt_to_head_page(objp); |
1629 | unsigned int objnr; |
1630 | |
1631 | objnr = obj_to_index(cachep, page, objp); |
1632 | if (objnr) { |
1633 | objp = index_to_obj(cachep, page, objnr - 1); |
1634 | realobj = (char *)objp + obj_offset(cachep); |
1635 | pr_err("Prev obj: start=%px, len=%d\n", realobj, size); |
1636 | print_objinfo(cachep, objp, 2); |
1637 | } |
1638 | if (objnr + 1 < cachep->num) { |
1639 | objp = index_to_obj(cachep, page, objnr + 1); |
1640 | realobj = (char *)objp + obj_offset(cachep); |
1641 | pr_err("Next obj: start=%px, len=%d\n", realobj, size); |
1642 | print_objinfo(cachep, objp, 2); |
1643 | } |
1644 | } |
1645 | } |
1646 | #endif |
1647 | |
1648 | #if DEBUG |
1649 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
1650 | struct page *page) |
1651 | { |
1652 | int i; |
1653 | |
1654 | if (OBJFREELIST_SLAB(cachep) && cachep->flags & SLAB_POISON) { |
1655 | poison_obj(cachep, page->freelist - obj_offset(cachep), |
1656 | POISON_FREE); |
1657 | } |
1658 | |
1659 | for (i = 0; i < cachep->num; i++) { |
1660 | void *objp = index_to_obj(cachep, page, i); |
1661 | |
1662 | if (cachep->flags & SLAB_POISON) { |
1663 | check_poison_obj(cachep, objp); |
1664 | slab_kernel_map(cachep, objp, 1, 0); |
1665 | } |
1666 | if (cachep->flags & SLAB_RED_ZONE) { |
1667 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
1668 | slab_error(cachep, "start of a freed object was overwritten"); |
1669 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
1670 | slab_error(cachep, "end of a freed object was overwritten"); |
1671 | } |
1672 | } |
1673 | } |
1674 | #else |
1675 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, |
1676 | struct page *page) |
1677 | { |
1678 | } |
1679 | #endif |
1680 | |
1681 | /** |
1682 | * slab_destroy - destroy and release all objects in a slab |
1683 | * @cachep: cache pointer being destroyed |
1684 | * @page: page pointer being destroyed |
1685 | * |
1686 | * Destroy all the objs in a slab page, and release the mem back to the system. |
1687 | * Before calling the slab page must have been unlinked from the cache. The |
1688 | * kmem_cache_node ->list_lock is not held/needed. |
1689 | */ |
1690 | static void slab_destroy(struct kmem_cache *cachep, struct page *page) |
1691 | { |
1692 | void *freelist; |
1693 | |
1694 | freelist = page->freelist; |
1695 | slab_destroy_debugcheck(cachep, page); |
1696 | if (unlikely(cachep->flags & SLAB_TYPESAFE_BY_RCU)) |
1697 | call_rcu(&page->rcu_head, kmem_rcu_free); |
1698 | else |
1699 | kmem_freepages(cachep, page); |
1700 | |
1701 | /* |
1702 | * From now on, we don't use freelist |
1703 | * although actual page can be freed in rcu context |
1704 | */ |
1705 | if (OFF_SLAB(cachep)) |
1706 | kmem_cache_free(cachep->freelist_cache, freelist); |
1707 | } |
1708 | |
1709 | static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list) |
1710 | { |
1711 | struct page *page, *n; |
1712 | |
1713 | list_for_each_entry_safe(page, n, list, lru) { |
1714 | list_del(&page->lru); |
1715 | slab_destroy(cachep, page); |
1716 | } |
1717 | } |
1718 | |
1719 | /** |
1720 | * calculate_slab_order - calculate size (page order) of slabs |
1721 | * @cachep: pointer to the cache that is being created |
1722 | * @size: size of objects to be created in this cache. |
1723 | * @flags: slab allocation flags |
1724 | * |
1725 | * Also calculates the number of objects per slab. |
1726 | * |
1727 | * This could be made much more intelligent. For now, try to avoid using |
1728 | * high order pages for slabs. When the gfp() functions are more friendly |
1729 | * towards high-order requests, this should be changed. |
1730 | * |
1731 | * Return: number of left-over bytes in a slab |
1732 | */ |
1733 | static size_t calculate_slab_order(struct kmem_cache *cachep, |
1734 | size_t size, slab_flags_t flags) |
1735 | { |
1736 | size_t left_over = 0; |
1737 | int gfporder; |
1738 | |
1739 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { |
1740 | unsigned int num; |
1741 | size_t remainder; |
1742 | |
1743 | num = cache_estimate(gfporder, size, flags, &remainder); |
1744 | if (!num) |
1745 | continue; |
1746 | |
1747 | /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */ |
1748 | if (num > SLAB_OBJ_MAX_NUM) |
1749 | break; |
1750 | |
1751 | if (flags & CFLGS_OFF_SLAB) { |
1752 | struct kmem_cache *freelist_cache; |
1753 | size_t freelist_size; |
1754 | |
1755 | freelist_size = num * sizeof(freelist_idx_t); |
1756 | freelist_cache = kmalloc_slab(freelist_size, 0u); |
1757 | if (!freelist_cache) |
1758 | continue; |
1759 | |
1760 | /* |
1761 | * Needed to avoid possible looping condition |
1762 | * in cache_grow_begin() |
1763 | */ |
1764 | if (OFF_SLAB(freelist_cache)) |
1765 | continue; |
1766 | |
1767 | /* check if off slab has enough benefit */ |
1768 | if (freelist_cache->size > cachep->size / 2) |
1769 | continue; |
1770 | } |
1771 | |
1772 | /* Found something acceptable - save it away */ |
1773 | cachep->num = num; |
1774 | cachep->gfporder = gfporder; |
1775 | left_over = remainder; |
1776 | |
1777 | /* |
1778 | * A VFS-reclaimable slab tends to have most allocations |
1779 | * as GFP_NOFS and we really don't want to have to be allocating |
1780 | * higher-order pages when we are unable to shrink dcache. |
1781 | */ |
1782 | if (flags & SLAB_RECLAIM_ACCOUNT) |
1783 | break; |
1784 | |
1785 | /* |
1786 | * Large number of objects is good, but very large slabs are |
1787 | * currently bad for the gfp()s. |
1788 | */ |
1789 | if (gfporder >= slab_max_order) |
1790 | break; |
1791 | |
1792 | /* |
1793 | * Acceptable internal fragmentation? |
1794 | */ |
1795 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) |
1796 | break; |
1797 | } |
1798 | return left_over; |
1799 | } |
1800 | |
1801 | static struct array_cache __percpu *alloc_kmem_cache_cpus( |
1802 | struct kmem_cache *cachep, int entries, int batchcount) |
1803 | { |
1804 | int cpu; |
1805 | size_t size; |
1806 | struct array_cache __percpu *cpu_cache; |
1807 | |
1808 | size = sizeof(void *) * entries + sizeof(struct array_cache); |
1809 | cpu_cache = __alloc_percpu(size, sizeof(void *)); |
1810 | |
1811 | if (!cpu_cache) |
1812 | return NULL; |
1813 | |
1814 | for_each_possible_cpu(cpu) { |
1815 | init_arraycache(per_cpu_ptr(cpu_cache, cpu), |
1816 | entries, batchcount); |
1817 | } |
1818 | |
1819 | return cpu_cache; |
1820 | } |
1821 | |
1822 | static int __ref setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) |
1823 | { |
1824 | if (slab_state >= FULL) |
1825 | return enable_cpucache(cachep, gfp); |
1826 | |
1827 | cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1); |
1828 | if (!cachep->cpu_cache) |
1829 | return 1; |
1830 | |
1831 | if (slab_state == DOWN) { |
1832 | /* Creation of first cache (kmem_cache). */ |
1833 | set_up_node(kmem_cache, CACHE_CACHE); |
1834 | } else if (slab_state == PARTIAL) { |
1835 | /* For kmem_cache_node */ |
1836 | set_up_node(cachep, SIZE_NODE); |
1837 | } else { |
1838 | int node; |
1839 | |
1840 | for_each_online_node(node) { |
1841 | cachep->node[node] = kmalloc_node( |
1842 | sizeof(struct kmem_cache_node), gfp, node); |
1843 | BUG_ON(!cachep->node[node]); |
1844 | kmem_cache_node_init(cachep->node[node]); |
1845 | } |
1846 | } |
1847 | |
1848 | cachep->node[numa_mem_id()]->next_reap = |
1849 | jiffies + REAPTIMEOUT_NODE + |
1850 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; |
1851 | |
1852 | cpu_cache_get(cachep)->avail = 0; |
1853 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; |
1854 | cpu_cache_get(cachep)->batchcount = 1; |
1855 | cpu_cache_get(cachep)->touched = 0; |
1856 | cachep->batchcount = 1; |
1857 | cachep->limit = BOOT_CPUCACHE_ENTRIES; |
1858 | return 0; |
1859 | } |
1860 | |
1861 | slab_flags_t kmem_cache_flags(unsigned int object_size, |
1862 | slab_flags_t flags, const char *name, |
1863 | void (*ctor)(void *)) |
1864 | { |
1865 | return flags; |
1866 | } |
1867 | |
1868 | struct kmem_cache * |
1869 | __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, |
1870 | slab_flags_t flags, void (*ctor)(void *)) |
1871 | { |
1872 | struct kmem_cache *cachep; |
1873 | |
1874 | cachep = find_mergeable(size, align, flags, name, ctor); |
1875 | if (cachep) { |
1876 | cachep->refcount++; |
1877 | |
1878 | /* |
1879 | * Adjust the object sizes so that we clear |
1880 | * the complete object on kzalloc. |
1881 | */ |
1882 | cachep->object_size = max_t(int, cachep->object_size, size); |
1883 | } |
1884 | return cachep; |
1885 | } |
1886 | |
1887 | static bool set_objfreelist_slab_cache(struct kmem_cache *cachep, |
1888 | size_t size, slab_flags_t flags) |
1889 | { |
1890 | size_t left; |
1891 | |
1892 | cachep->num = 0; |
1893 | |
1894 | if (cachep->ctor || flags & SLAB_TYPESAFE_BY_RCU) |
1895 | return false; |
1896 | |
1897 | left = calculate_slab_order(cachep, size, |
1898 | flags | CFLGS_OBJFREELIST_SLAB); |
1899 | if (!cachep->num) |
1900 | return false; |
1901 | |
1902 | if (cachep->num * sizeof(freelist_idx_t) > cachep->object_size) |
1903 | return false; |
1904 | |
1905 | cachep->colour = left / cachep->colour_off; |
1906 | |
1907 | return true; |
1908 | } |
1909 | |
1910 | static bool set_off_slab_cache(struct kmem_cache *cachep, |
1911 | size_t size, slab_flags_t flags) |
1912 | { |
1913 | size_t left; |
1914 | |
1915 | cachep->num = 0; |
1916 | |
1917 | /* |
1918 | * Always use on-slab management when SLAB_NOLEAKTRACE |
1919 | * to avoid recursive calls into kmemleak. |
1920 | */ |
1921 | if (flags & SLAB_NOLEAKTRACE) |
1922 | return false; |
1923 | |
1924 | /* |
1925 | * Size is large, assume best to place the slab management obj |
1926 | * off-slab (should allow better packing of objs). |
1927 | */ |
1928 | left = calculate_slab_order(cachep, size, flags | CFLGS_OFF_SLAB); |
1929 | if (!cachep->num) |
1930 | return false; |
1931 | |
1932 | /* |
1933 | * If the slab has been placed off-slab, and we have enough space then |
1934 | * move it on-slab. This is at the expense of any extra colouring. |
1935 | */ |
1936 | if (left >= cachep->num * sizeof(freelist_idx_t)) |
1937 | return false; |
1938 | |
1939 | cachep->colour = left / cachep->colour_off; |
1940 | |
1941 | return true; |
1942 | } |
1943 | |
1944 | static bool set_on_slab_cache(struct kmem_cache *cachep, |
1945 | size_t size, slab_flags_t flags) |
1946 | { |
1947 | size_t left; |
1948 | |
1949 | cachep->num = 0; |
1950 | |
1951 | left = calculate_slab_order(cachep, size, flags); |
1952 | if (!cachep->num) |
1953 | return false; |
1954 | |
1955 | cachep->colour = left / cachep->colour_off; |
1956 | |
1957 | return true; |
1958 | } |
1959 | |
1960 | /** |
1961 | * __kmem_cache_create - Create a cache. |
1962 | * @cachep: cache management descriptor |
1963 | * @flags: SLAB flags |
1964 | * |
1965 | * Returns a ptr to the cache on success, NULL on failure. |
1966 | * Cannot be called within a int, but can be interrupted. |
1967 | * The @ctor is run when new pages are allocated by the cache. |
1968 | * |
1969 | * The flags are |
1970 | * |
1971 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) |
1972 | * to catch references to uninitialised memory. |
1973 | * |
1974 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check |
1975 | * for buffer overruns. |
1976 | * |
1977 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware |
1978 | * cacheline. This can be beneficial if you're counting cycles as closely |
1979 | * as davem. |
1980 | * |
1981 | * Return: a pointer to the created cache or %NULL in case of error |
1982 | */ |
1983 | int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags) |
1984 | { |
1985 | size_t ralign = BYTES_PER_WORD; |
1986 | gfp_t gfp; |
1987 | int err; |
1988 | unsigned int size = cachep->size; |
1989 | |
1990 | #if DEBUG |
1991 | #if FORCED_DEBUG |
1992 | /* |
1993 | * Enable redzoning and last user accounting, except for caches with |
1994 | * large objects, if the increased size would increase the object size |
1995 | * above the next power of two: caches with object sizes just above a |
1996 | * power of two have a significant amount of internal fragmentation. |
1997 | */ |
1998 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + |
1999 | 2 * sizeof(unsigned long long))) |
2000 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; |
2001 | if (!(flags & SLAB_TYPESAFE_BY_RCU)) |
2002 | flags |= SLAB_POISON; |
2003 | #endif |
2004 | #endif |
2005 | |
2006 | /* |
2007 | * Check that size is in terms of words. This is needed to avoid |
2008 | * unaligned accesses for some archs when redzoning is used, and makes |
2009 | * sure any on-slab bufctl's are also correctly aligned. |
2010 | */ |
2011 | size = ALIGN(size, BYTES_PER_WORD); |
2012 | |
2013 | if (flags & SLAB_RED_ZONE) { |
2014 | ralign = REDZONE_ALIGN; |
2015 | /* If redzoning, ensure that the second redzone is suitably |
2016 | * aligned, by adjusting the object size accordingly. */ |
2017 | size = ALIGN(size, REDZONE_ALIGN); |
2018 | } |
2019 | |
2020 | /* 3) caller mandated alignment */ |
2021 | if (ralign < cachep->align) { |
2022 | ralign = cachep->align; |
2023 | } |
2024 | /* disable debug if necessary */ |
2025 | if (ralign > __alignof__(unsigned long long)) |
2026 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2027 | /* |
2028 | * 4) Store it. |
2029 | */ |
2030 | cachep->align = ralign; |
2031 | cachep->colour_off = cache_line_size(); |
2032 | /* Offset must be a multiple of the alignment. */ |
2033 | if (cachep->colour_off < cachep->align) |
2034 | cachep->colour_off = cachep->align; |
2035 | |
2036 | if (slab_is_available()) |
2037 | gfp = GFP_KERNEL; |
2038 | else |
2039 | gfp = GFP_NOWAIT; |
2040 | |
2041 | #if DEBUG |
2042 | |
2043 | /* |
2044 | * Both debugging options require word-alignment which is calculated |
2045 | * into align above. |
2046 | */ |
2047 | if (flags & SLAB_RED_ZONE) { |
2048 | /* add space for red zone words */ |
2049 | cachep->obj_offset += sizeof(unsigned long long); |
2050 | size += 2 * sizeof(unsigned long long); |
2051 | } |
2052 | if (flags & SLAB_STORE_USER) { |
2053 | /* user store requires one word storage behind the end of |
2054 | * the real object. But if the second red zone needs to be |
2055 | * aligned to 64 bits, we must allow that much space. |
2056 | */ |
2057 | if (flags & SLAB_RED_ZONE) |
2058 | size += REDZONE_ALIGN; |
2059 | else |
2060 | size += BYTES_PER_WORD; |
2061 | } |
2062 | #endif |
2063 | |
2064 | kasan_cache_create(cachep, &size, &flags); |
2065 | |
2066 | size = ALIGN(size, cachep->align); |
2067 | /* |
2068 | * We should restrict the number of objects in a slab to implement |
2069 | * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition. |
2070 | */ |
2071 | if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE) |
2072 | size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align); |
2073 | |
2074 | #if DEBUG |
2075 | /* |
2076 | * To activate debug pagealloc, off-slab management is necessary |
2077 | * requirement. In early phase of initialization, small sized slab |
2078 | * doesn't get initialized so it would not be possible. So, we need |
2079 | * to check size >= 256. It guarantees that all necessary small |
2080 | * sized slab is initialized in current slab initialization sequence. |
2081 | */ |
2082 | if (debug_pagealloc_enabled() && (flags & SLAB_POISON) && |
2083 | size >= 256 && cachep->object_size > cache_line_size()) { |
2084 | if (size < PAGE_SIZE || size % PAGE_SIZE == 0) { |
2085 | size_t tmp_size = ALIGN(size, PAGE_SIZE); |
2086 | |
2087 | if (set_off_slab_cache(cachep, tmp_size, flags)) { |
2088 | flags |= CFLGS_OFF_SLAB; |
2089 | cachep->obj_offset += tmp_size - size; |
2090 | size = tmp_size; |
2091 | goto done; |
2092 | } |
2093 | } |
2094 | } |
2095 | #endif |
2096 | |
2097 | if (set_objfreelist_slab_cache(cachep, size, flags)) { |
2098 | flags |= CFLGS_OBJFREELIST_SLAB; |
2099 | goto done; |
2100 | } |
2101 | |
2102 | if (set_off_slab_cache(cachep, size, flags)) { |
2103 | flags |= CFLGS_OFF_SLAB; |
2104 | goto done; |
2105 | } |
2106 | |
2107 | if (set_on_slab_cache(cachep, size, flags)) |
2108 | goto done; |
2109 | |
2110 | return -E2BIG; |
2111 | |
2112 | done: |
2113 | cachep->freelist_size = cachep->num * sizeof(freelist_idx_t); |
2114 | cachep->flags = flags; |
2115 | cachep->allocflags = __GFP_COMP; |
2116 | if (flags & SLAB_CACHE_DMA) |
2117 | cachep->allocflags |= GFP_DMA; |
2118 | if (flags & SLAB_RECLAIM_ACCOUNT) |
2119 | cachep->allocflags |= __GFP_RECLAIMABLE; |
2120 | cachep->size = size; |
2121 | cachep->reciprocal_buffer_size = reciprocal_value(size); |
2122 | |
2123 | #if DEBUG |
2124 | /* |
2125 | * If we're going to use the generic kernel_map_pages() |
2126 | * poisoning, then it's going to smash the contents of |
2127 | * the redzone and userword anyhow, so switch them off. |
2128 | */ |
2129 | if (IS_ENABLED(CONFIG_PAGE_POISONING) && |
2130 | (cachep->flags & SLAB_POISON) && |
2131 | is_debug_pagealloc_cache(cachep)) |
2132 | cachep->flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); |
2133 | #endif |
2134 | |
2135 | if (OFF_SLAB(cachep)) { |
2136 | cachep->freelist_cache = |
2137 | kmalloc_slab(cachep->freelist_size, 0u); |
2138 | } |
2139 | |
2140 | err = setup_cpu_cache(cachep, gfp); |
2141 | if (err) { |
2142 | __kmem_cache_release(cachep); |
2143 | return err; |
2144 | } |
2145 | |
2146 | return 0; |
2147 | } |
2148 | |
2149 | #if DEBUG |
2150 | static void check_irq_off(void) |
2151 | { |
2152 | BUG_ON(!irqs_disabled()); |
2153 | } |
2154 | |
2155 | static void check_irq_on(void) |
2156 | { |
2157 | BUG_ON(irqs_disabled()); |
2158 | } |
2159 | |
2160 | static void check_mutex_acquired(void) |
2161 | { |
2162 | BUG_ON(!mutex_is_locked(&slab_mutex)); |
2163 | } |
2164 | |
2165 | static void check_spinlock_acquired(struct kmem_cache *cachep) |
2166 | { |
2167 | #ifdef CONFIG_SMP |
2168 | check_irq_off(); |
2169 | assert_spin_locked(&get_node(cachep, numa_mem_id())->list_lock); |
2170 | #endif |
2171 | } |
2172 | |
2173 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) |
2174 | { |
2175 | #ifdef CONFIG_SMP |
2176 | check_irq_off(); |
2177 | assert_spin_locked(&get_node(cachep, node)->list_lock); |
2178 | #endif |
2179 | } |
2180 | |
2181 | #else |
2182 | #define check_irq_off() do { } while(0) |
2183 | #define check_irq_on() do { } while(0) |
2184 | #define check_mutex_acquired() do { } while(0) |
2185 | #define check_spinlock_acquired(x) do { } while(0) |
2186 | #define check_spinlock_acquired_node(x, y) do { } while(0) |
2187 | #endif |
2188 | |
2189 | static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac, |
2190 | int node, bool free_all, struct list_head *list) |
2191 | { |
2192 | int tofree; |
2193 | |
2194 | if (!ac || !ac->avail) |
2195 | return; |
2196 | |
2197 | tofree = free_all ? ac->avail : (ac->limit + 4) / 5; |
2198 | if (tofree > ac->avail) |
2199 | tofree = (ac->avail + 1) / 2; |
2200 | |
2201 | free_block(cachep, ac->entry, tofree, node, list); |
2202 | ac->avail -= tofree; |
2203 | memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail); |
2204 | } |
2205 | |
2206 | static void do_drain(void *arg) |
2207 | { |
2208 | struct kmem_cache *cachep = arg; |
2209 | struct array_cache *ac; |
2210 | int node = numa_mem_id(); |
2211 | struct kmem_cache_node *n; |
2212 | LIST_HEAD(list); |
2213 | |
2214 | check_irq_off(); |
2215 | ac = cpu_cache_get(cachep); |
2216 | n = get_node(cachep, node); |
2217 | spin_lock(&n->list_lock); |
2218 | free_block(cachep, ac->entry, ac->avail, node, &list); |
2219 | spin_unlock(&n->list_lock); |
2220 | slabs_destroy(cachep, &list); |
2221 | ac->avail = 0; |
2222 | } |
2223 | |
2224 | static void drain_cpu_caches(struct kmem_cache *cachep) |
2225 | { |
2226 | struct kmem_cache_node *n; |
2227 | int node; |
2228 | LIST_HEAD(list); |
2229 | |
2230 | on_each_cpu(do_drain, cachep, 1); |
2231 | check_irq_on(); |
2232 | for_each_kmem_cache_node(cachep, node, n) |
2233 | if (n->alien) |
2234 | drain_alien_cache(cachep, n->alien); |
2235 | |
2236 | for_each_kmem_cache_node(cachep, node, n) { |
2237 | spin_lock_irq(&n->list_lock); |
2238 | drain_array_locked(cachep, n->shared, node, true, &list); |
2239 | spin_unlock_irq(&n->list_lock); |
2240 | |
2241 | slabs_destroy(cachep, &list); |
2242 | } |
2243 | } |
2244 | |
2245 | /* |
2246 | * Remove slabs from the list of free slabs. |
2247 | * Specify the number of slabs to drain in tofree. |
2248 | * |
2249 | * Returns the actual number of slabs released. |
2250 | */ |
2251 | static int drain_freelist(struct kmem_cache *cache, |
2252 | struct kmem_cache_node *n, int tofree) |
2253 | { |
2254 | struct list_head *p; |
2255 | int nr_freed; |
2256 | struct page *page; |
2257 | |
2258 | nr_freed = 0; |
2259 | while (nr_freed < tofree && !list_empty(&n->slabs_free)) { |
2260 | |
2261 | spin_lock_irq(&n->list_lock); |
2262 | p = n->slabs_free.prev; |
2263 | if (p == &n->slabs_free) { |
2264 | spin_unlock_irq(&n->list_lock); |
2265 | goto out; |
2266 | } |
2267 | |
2268 | page = list_entry(p, struct page, lru); |
2269 | list_del(&page->lru); |
2270 | n->free_slabs--; |
2271 | n->total_slabs--; |
2272 | /* |
2273 | * Safe to drop the lock. The slab is no longer linked |
2274 | * to the cache. |
2275 | */ |
2276 | n->free_objects -= cache->num; |
2277 | spin_unlock_irq(&n->list_lock); |
2278 | slab_destroy(cache, page); |
2279 | nr_freed++; |
2280 | } |
2281 | out: |
2282 | return nr_freed; |
2283 | } |
2284 | |
2285 | bool __kmem_cache_empty(struct kmem_cache *s) |
2286 | { |
2287 | int node; |
2288 | struct kmem_cache_node *n; |
2289 | |
2290 | for_each_kmem_cache_node(s, node, n) |
2291 | if (!list_empty(&n->slabs_full) || |
2292 | !list_empty(&n->slabs_partial)) |
2293 | return false; |
2294 | return true; |
2295 | } |
2296 | |
2297 | int __kmem_cache_shrink(struct kmem_cache *cachep) |
2298 | { |
2299 | int ret = 0; |
2300 | int node; |
2301 | struct kmem_cache_node *n; |
2302 | |
2303 | drain_cpu_caches(cachep); |
2304 | |
2305 | check_irq_on(); |
2306 | for_each_kmem_cache_node(cachep, node, n) { |
2307 | drain_freelist(cachep, n, INT_MAX); |
2308 | |
2309 | ret += !list_empty(&n->slabs_full) || |
2310 | !list_empty(&n->slabs_partial); |
2311 | } |
2312 | return (ret ? 1 : 0); |
2313 | } |
2314 | |
2315 | #ifdef CONFIG_MEMCG |
2316 | void __kmemcg_cache_deactivate(struct kmem_cache *cachep) |
2317 | { |
2318 | __kmem_cache_shrink(cachep); |
2319 | } |
2320 | #endif |
2321 | |
2322 | int __kmem_cache_shutdown(struct kmem_cache *cachep) |
2323 | { |
2324 | return __kmem_cache_shrink(cachep); |
2325 | } |
2326 | |
2327 | void __kmem_cache_release(struct kmem_cache *cachep) |
2328 | { |
2329 | int i; |
2330 | struct kmem_cache_node *n; |
2331 | |
2332 | cache_random_seq_destroy(cachep); |
2333 | |
2334 | free_percpu(cachep->cpu_cache); |
2335 | |
2336 | /* NUMA: free the node structures */ |
2337 | for_each_kmem_cache_node(cachep, i, n) { |
2338 | kfree(n->shared); |
2339 | free_alien_cache(n->alien); |
2340 | kfree(n); |
2341 | cachep->node[i] = NULL; |
2342 | } |
2343 | } |
2344 | |
2345 | /* |
2346 | * Get the memory for a slab management obj. |
2347 | * |
2348 | * For a slab cache when the slab descriptor is off-slab, the |
2349 | * slab descriptor can't come from the same cache which is being created, |
2350 | * Because if it is the case, that means we defer the creation of |
2351 | * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point. |
2352 | * And we eventually call down to __kmem_cache_create(), which |
2353 | * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one. |
2354 | * This is a "chicken-and-egg" problem. |
2355 | * |
2356 | * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches, |
2357 | * which are all initialized during kmem_cache_init(). |
2358 | */ |
2359 | static void *alloc_slabmgmt(struct kmem_cache *cachep, |
2360 | struct page *page, int colour_off, |
2361 | gfp_t local_flags, int nodeid) |
2362 | { |
2363 | void *freelist; |
2364 | void *addr = page_address(page); |
2365 | |
2366 | page->s_mem = addr + colour_off; |
2367 | page->active = 0; |
2368 | |
2369 | if (OBJFREELIST_SLAB(cachep)) |
2370 | freelist = NULL; |
2371 | else if (OFF_SLAB(cachep)) { |
2372 | /* Slab management obj is off-slab. */ |
2373 | freelist = kmem_cache_alloc_node(cachep->freelist_cache, |
2374 | local_flags, nodeid); |
2375 | freelist = kasan_reset_tag(freelist); |
2376 | if (!freelist) |
2377 | return NULL; |
2378 | } else { |
2379 | /* We will use last bytes at the slab for freelist */ |
2380 | freelist = addr + (PAGE_SIZE << cachep->gfporder) - |
2381 | cachep->freelist_size; |
2382 | } |
2383 | |
2384 | return freelist; |
2385 | } |
2386 | |
2387 | static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx) |
2388 | { |
2389 | return ((freelist_idx_t *)page->freelist)[idx]; |
2390 | } |
2391 | |
2392 | static inline void set_free_obj(struct page *page, |
2393 | unsigned int idx, freelist_idx_t val) |
2394 | { |
2395 | ((freelist_idx_t *)(page->freelist))[idx] = val; |
2396 | } |
2397 | |
2398 | static void cache_init_objs_debug(struct kmem_cache *cachep, struct page *page) |
2399 | { |
2400 | #if DEBUG |
2401 | int i; |
2402 | |
2403 | for (i = 0; i < cachep->num; i++) { |
2404 | void *objp = index_to_obj(cachep, page, i); |
2405 | |
2406 | if (cachep->flags & SLAB_STORE_USER) |
2407 | *dbg_userword(cachep, objp) = NULL; |
2408 | |
2409 | if (cachep->flags & SLAB_RED_ZONE) { |
2410 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2411 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2412 | } |
2413 | /* |
2414 | * Constructors are not allowed to allocate memory from the same |
2415 | * cache which they are a constructor for. Otherwise, deadlock. |
2416 | * They must also be threaded. |
2417 | */ |
2418 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) { |
2419 | kasan_unpoison_object_data(cachep, |
2420 | objp + obj_offset(cachep)); |
2421 | cachep->ctor(objp + obj_offset(cachep)); |
2422 | kasan_poison_object_data( |
2423 | cachep, objp + obj_offset(cachep)); |
2424 | } |
2425 | |
2426 | if (cachep->flags & SLAB_RED_ZONE) { |
2427 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) |
2428 | slab_error(cachep, "constructor overwrote the end of an object"); |
2429 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) |
2430 | slab_error(cachep, "constructor overwrote the start of an object"); |
2431 | } |
2432 | /* need to poison the objs? */ |
2433 | if (cachep->flags & SLAB_POISON) { |
2434 | poison_obj(cachep, objp, POISON_FREE); |
2435 | slab_kernel_map(cachep, objp, 0, 0); |
2436 | } |
2437 | } |
2438 | #endif |
2439 | } |
2440 | |
2441 | #ifdef CONFIG_SLAB_FREELIST_RANDOM |
2442 | /* Hold information during a freelist initialization */ |
2443 | union freelist_init_state { |
2444 | struct { |
2445 | unsigned int pos; |
2446 | unsigned int *list; |
2447 | unsigned int count; |
2448 | }; |
2449 | struct rnd_state rnd_state; |
2450 | }; |
2451 | |
2452 | /* |
2453 | * Initialize the state based on the randomization methode available. |
2454 | * return true if the pre-computed list is available, false otherwize. |
2455 | */ |
2456 | static bool freelist_state_initialize(union freelist_init_state *state, |
2457 | struct kmem_cache *cachep, |
2458 | unsigned int count) |
2459 | { |
2460 | bool ret; |
2461 | unsigned int rand; |
2462 | |
2463 | /* Use best entropy available to define a random shift */ |
2464 | rand = get_random_int(); |
2465 | |
2466 | /* Use a random state if the pre-computed list is not available */ |
2467 | if (!cachep->random_seq) { |
2468 | prandom_seed_state(&state->rnd_state, rand); |
2469 | ret = false; |
2470 | } else { |
2471 | state->list = cachep->random_seq; |
2472 | state->count = count; |
2473 | state->pos = rand % count; |
2474 | ret = true; |
2475 | } |
2476 | return ret; |
2477 | } |
2478 | |
2479 | /* Get the next entry on the list and randomize it using a random shift */ |
2480 | static freelist_idx_t next_random_slot(union freelist_init_state *state) |
2481 | { |
2482 | if (state->pos >= state->count) |
2483 | state->pos = 0; |
2484 | return state->list[state->pos++]; |
2485 | } |
2486 | |
2487 | /* Swap two freelist entries */ |
2488 | static void swap_free_obj(struct page *page, unsigned int a, unsigned int b) |
2489 | { |
2490 | swap(((freelist_idx_t *)page->freelist)[a], |
2491 | ((freelist_idx_t *)page->freelist)[b]); |
2492 | } |
2493 | |
2494 | /* |
2495 | * Shuffle the freelist initialization state based on pre-computed lists. |
2496 | * return true if the list was successfully shuffled, false otherwise. |
2497 | */ |
2498 | static bool shuffle_freelist(struct kmem_cache *cachep, struct page *page) |
2499 | { |
2500 | unsigned int objfreelist = 0, i, rand, count = cachep->num; |
2501 | union freelist_init_state state; |
2502 | bool precomputed; |
2503 | |
2504 | if (count < 2) |
2505 | return false; |
2506 | |
2507 | precomputed = freelist_state_initialize(&state, cachep, count); |
2508 | |
2509 | /* Take a random entry as the objfreelist */ |
2510 | if (OBJFREELIST_SLAB(cachep)) { |
2511 | if (!precomputed) |
2512 | objfreelist = count - 1; |
2513 | else |
2514 | objfreelist = next_random_slot(&state); |
2515 | page->freelist = index_to_obj(cachep, page, objfreelist) + |
2516 | obj_offset(cachep); |
2517 | count--; |
2518 | } |
2519 | |
2520 | /* |
2521 | * On early boot, generate the list dynamically. |
2522 | * Later use a pre-computed list for speed. |
2523 | */ |
2524 | if (!precomputed) { |
2525 | for (i = 0; i < count; i++) |
2526 | set_free_obj(page, i, i); |
2527 | |
2528 | /* Fisher-Yates shuffle */ |
2529 | for (i = count - 1; i > 0; i--) { |
2530 | rand = prandom_u32_state(&state.rnd_state); |
2531 | rand %= (i + 1); |
2532 | swap_free_obj(page, i, rand); |
2533 | } |
2534 | } else { |
2535 | for (i = 0; i < count; i++) |
2536 | set_free_obj(page, i, next_random_slot(&state)); |
2537 | } |
2538 | |
2539 | if (OBJFREELIST_SLAB(cachep)) |
2540 | set_free_obj(page, cachep->num - 1, objfreelist); |
2541 | |
2542 | return true; |
2543 | } |
2544 | #else |
2545 | static inline bool shuffle_freelist(struct kmem_cache *cachep, |
2546 | struct page *page) |
2547 | { |
2548 | return false; |
2549 | } |
2550 | #endif /* CONFIG_SLAB_FREELIST_RANDOM */ |
2551 | |
2552 | static void cache_init_objs(struct kmem_cache *cachep, |
2553 | struct page *page) |
2554 | { |
2555 | int i; |
2556 | void *objp; |
2557 | bool shuffled; |
2558 | |
2559 | cache_init_objs_debug(cachep, page); |
2560 | |
2561 | /* Try to randomize the freelist if enabled */ |
2562 | shuffled = shuffle_freelist(cachep, page); |
2563 | |
2564 | if (!shuffled && OBJFREELIST_SLAB(cachep)) { |
2565 | page->freelist = index_to_obj(cachep, page, cachep->num - 1) + |
2566 | obj_offset(cachep); |
2567 | } |
2568 | |
2569 | for (i = 0; i < cachep->num; i++) { |
2570 | objp = index_to_obj(cachep, page, i); |
2571 | objp = kasan_init_slab_obj(cachep, objp); |
2572 | |
2573 | /* constructor could break poison info */ |
2574 | if (DEBUG == 0 && cachep->ctor) { |
2575 | kasan_unpoison_object_data(cachep, objp); |
2576 | cachep->ctor(objp); |
2577 | kasan_poison_object_data(cachep, objp); |
2578 | } |
2579 | |
2580 | if (!shuffled) |
2581 | set_free_obj(page, i, i); |
2582 | } |
2583 | } |
2584 | |
2585 | static void *slab_get_obj(struct kmem_cache *cachep, struct page *page) |
2586 | { |
2587 | void *objp; |
2588 | |
2589 | objp = index_to_obj(cachep, page, get_free_obj(page, page->active)); |
2590 | page->active++; |
2591 | |
2592 | #if DEBUG |
2593 | if (cachep->flags & SLAB_STORE_USER) |
2594 | set_store_user_dirty(cachep); |
2595 | #endif |
2596 | |
2597 | return objp; |
2598 | } |
2599 | |
2600 | static void slab_put_obj(struct kmem_cache *cachep, |
2601 | struct page *page, void *objp) |
2602 | { |
2603 | unsigned int objnr = obj_to_index(cachep, page, objp); |
2604 | #if DEBUG |
2605 | unsigned int i; |
2606 | |
2607 | /* Verify double free bug */ |
2608 | for (i = page->active; i < cachep->num; i++) { |
2609 | if (get_free_obj(page, i) == objnr) { |
2610 | pr_err("slab: double free detected in cache '%s', objp %px\n", |
2611 | cachep->name, objp); |
2612 | BUG(); |
2613 | } |
2614 | } |
2615 | #endif |
2616 | page->active--; |
2617 | if (!page->freelist) |
2618 | page->freelist = objp + obj_offset(cachep); |
2619 | |
2620 | set_free_obj(page, page->active, objnr); |
2621 | } |
2622 | |
2623 | /* |
2624 | * Map pages beginning at addr to the given cache and slab. This is required |
2625 | * for the slab allocator to be able to lookup the cache and slab of a |
2626 | * virtual address for kfree, ksize, and slab debugging. |
2627 | */ |
2628 | static void slab_map_pages(struct kmem_cache *cache, struct page *page, |
2629 | void *freelist) |
2630 | { |
2631 | page->slab_cache = cache; |
2632 | page->freelist = freelist; |
2633 | } |
2634 | |
2635 | /* |
2636 | * Grow (by 1) the number of slabs within a cache. This is called by |
2637 | * kmem_cache_alloc() when there are no active objs left in a cache. |
2638 | */ |
2639 | static struct page *cache_grow_begin(struct kmem_cache *cachep, |
2640 | gfp_t flags, int nodeid) |
2641 | { |
2642 | void *freelist; |
2643 | size_t offset; |
2644 | gfp_t local_flags; |
2645 | int page_node; |
2646 | struct kmem_cache_node *n; |
2647 | struct page *page; |
2648 | |
2649 | /* |
2650 | * Be lazy and only check for valid flags here, keeping it out of the |
2651 | * critical path in kmem_cache_alloc(). |
2652 | */ |
2653 | if (unlikely(flags & GFP_SLAB_BUG_MASK)) { |
2654 | gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; |
2655 | flags &= ~GFP_SLAB_BUG_MASK; |
2656 | pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", |
2657 | invalid_mask, &invalid_mask, flags, &flags); |
2658 | dump_stack(); |
2659 | } |
2660 | WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO)); |
2661 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); |
2662 | |
2663 | check_irq_off(); |
2664 | if (gfpflags_allow_blocking(local_flags)) |
2665 | local_irq_enable(); |
2666 | |
2667 | /* |
2668 | * Get mem for the objs. Attempt to allocate a physical page from |
2669 | * 'nodeid'. |
2670 | */ |
2671 | page = kmem_getpages(cachep, local_flags, nodeid); |
2672 | if (!page) |
2673 | goto failed; |
2674 | |
2675 | page_node = page_to_nid(page); |
2676 | n = get_node(cachep, page_node); |
2677 | |
2678 | /* Get colour for the slab, and cal the next value. */ |
2679 | n->colour_next++; |
2680 | if (n->colour_next >= cachep->colour) |
2681 | n->colour_next = 0; |
2682 | |
2683 | offset = n->colour_next; |
2684 | if (offset >= cachep->colour) |
2685 | offset = 0; |
2686 | |
2687 | offset *= cachep->colour_off; |
2688 | |
2689 | /* |
2690 | * Call kasan_poison_slab() before calling alloc_slabmgmt(), so |
2691 | * page_address() in the latter returns a non-tagged pointer, |
2692 | * as it should be for slab pages. |
2693 | */ |
2694 | kasan_poison_slab(page); |
2695 | |
2696 | /* Get slab management. */ |
2697 | freelist = alloc_slabmgmt(cachep, page, offset, |
2698 | local_flags & ~GFP_CONSTRAINT_MASK, page_node); |
2699 | if (OFF_SLAB(cachep) && !freelist) |
2700 | goto opps1; |
2701 | |
2702 | slab_map_pages(cachep, page, freelist); |
2703 | |
2704 | cache_init_objs(cachep, page); |
2705 | |
2706 | if (gfpflags_allow_blocking(local_flags)) |
2707 | local_irq_disable(); |
2708 | |
2709 | return page; |
2710 | |
2711 | opps1: |
2712 | kmem_freepages(cachep, page); |
2713 | failed: |
2714 | if (gfpflags_allow_blocking(local_flags)) |
2715 | local_irq_disable(); |
2716 | return NULL; |
2717 | } |
2718 | |
2719 | static void cache_grow_end(struct kmem_cache *cachep, struct page *page) |
2720 | { |
2721 | struct kmem_cache_node *n; |
2722 | void *list = NULL; |
2723 | |
2724 | check_irq_off(); |
2725 | |
2726 | if (!page) |
2727 | return; |
2728 | |
2729 | INIT_LIST_HEAD(&page->lru); |
2730 | n = get_node(cachep, page_to_nid(page)); |
2731 | |
2732 | spin_lock(&n->list_lock); |
2733 | n->total_slabs++; |
2734 | if (!page->active) { |
2735 | list_add_tail(&page->lru, &(n->slabs_free)); |
2736 | n->free_slabs++; |
2737 | } else |
2738 | fixup_slab_list(cachep, n, page, &list); |
2739 | |
2740 | STATS_INC_GROWN(cachep); |
2741 | n->free_objects += cachep->num - page->active; |
2742 | spin_unlock(&n->list_lock); |
2743 | |
2744 | fixup_objfreelist_debug(cachep, &list); |
2745 | } |
2746 | |
2747 | #if DEBUG |
2748 | |
2749 | /* |
2750 | * Perform extra freeing checks: |
2751 | * - detect bad pointers. |
2752 | * - POISON/RED_ZONE checking |
2753 | */ |
2754 | static void kfree_debugcheck(const void *objp) |
2755 | { |
2756 | if (!virt_addr_valid(objp)) { |
2757 | pr_err("kfree_debugcheck: out of range ptr %lxh\n", |
2758 | (unsigned long)objp); |
2759 | BUG(); |
2760 | } |
2761 | } |
2762 | |
2763 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) |
2764 | { |
2765 | unsigned long long redzone1, redzone2; |
2766 | |
2767 | redzone1 = *dbg_redzone1(cache, obj); |
2768 | redzone2 = *dbg_redzone2(cache, obj); |
2769 | |
2770 | /* |
2771 | * Redzone is ok. |
2772 | */ |
2773 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) |
2774 | return; |
2775 | |
2776 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) |
2777 | slab_error(cache, "double free detected"); |
2778 | else |
2779 | slab_error(cache, "memory outside object was overwritten"); |
2780 | |
2781 | pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n", |
2782 | obj, redzone1, redzone2); |
2783 | } |
2784 | |
2785 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, |
2786 | unsigned long caller) |
2787 | { |
2788 | unsigned int objnr; |
2789 | struct page *page; |
2790 | |
2791 | BUG_ON(virt_to_cache(objp) != cachep); |
2792 | |
2793 | objp -= obj_offset(cachep); |
2794 | kfree_debugcheck(objp); |
2795 | page = virt_to_head_page(objp); |
2796 | |
2797 | if (cachep->flags & SLAB_RED_ZONE) { |
2798 | verify_redzone_free(cachep, objp); |
2799 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; |
2800 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; |
2801 | } |
2802 | if (cachep->flags & SLAB_STORE_USER) { |
2803 | set_store_user_dirty(cachep); |
2804 | *dbg_userword(cachep, objp) = (void *)caller; |
2805 | } |
2806 | |
2807 | objnr = obj_to_index(cachep, page, objp); |
2808 | |
2809 | BUG_ON(objnr >= cachep->num); |
2810 | BUG_ON(objp != index_to_obj(cachep, page, objnr)); |
2811 | |
2812 | if (cachep->flags & SLAB_POISON) { |
2813 | poison_obj(cachep, objp, POISON_FREE); |
2814 | slab_kernel_map(cachep, objp, 0, caller); |
2815 | } |
2816 | return objp; |
2817 | } |
2818 | |
2819 | #else |
2820 | #define kfree_debugcheck(x) do { } while(0) |
2821 | #define cache_free_debugcheck(x,objp,z) (objp) |
2822 | #endif |
2823 | |
2824 | static inline void fixup_objfreelist_debug(struct kmem_cache *cachep, |
2825 | void **list) |
2826 | { |
2827 | #if DEBUG |
2828 | void *next = *list; |
2829 | void *objp; |
2830 | |
2831 | while (next) { |
2832 | objp = next - obj_offset(cachep); |
2833 | next = *(void **)next; |
2834 | poison_obj(cachep, objp, POISON_FREE); |
2835 | } |
2836 | #endif |
2837 | } |
2838 | |
2839 | static inline void fixup_slab_list(struct kmem_cache *cachep, |
2840 | struct kmem_cache_node *n, struct page *page, |
2841 | void **list) |
2842 | { |
2843 | /* move slabp to correct slabp list: */ |
2844 | list_del(&page->lru); |
2845 | if (page->active == cachep->num) { |
2846 | list_add(&page->lru, &n->slabs_full); |
2847 | if (OBJFREELIST_SLAB(cachep)) { |
2848 | #if DEBUG |
2849 | /* Poisoning will be done without holding the lock */ |
2850 | if (cachep->flags & SLAB_POISON) { |
2851 | void **objp = page->freelist; |
2852 | |
2853 | *objp = *list; |
2854 | *list = objp; |
2855 | } |
2856 | #endif |
2857 | page->freelist = NULL; |
2858 | } |
2859 | } else |
2860 | list_add(&page->lru, &n->slabs_partial); |
2861 | } |
2862 | |
2863 | /* Try to find non-pfmemalloc slab if needed */ |
2864 | static noinline struct page *get_valid_first_slab(struct kmem_cache_node *n, |
2865 | struct page *page, bool pfmemalloc) |
2866 | { |
2867 | if (!page) |
2868 | return NULL; |
2869 | |
2870 | if (pfmemalloc) |
2871 | return page; |
2872 | |
2873 | if (!PageSlabPfmemalloc(page)) |
2874 | return page; |
2875 | |
2876 | /* No need to keep pfmemalloc slab if we have enough free objects */ |
2877 | if (n->free_objects > n->free_limit) { |
2878 | ClearPageSlabPfmemalloc(page); |
2879 | return page; |
2880 | } |
2881 | |
2882 | /* Move pfmemalloc slab to the end of list to speed up next search */ |
2883 | list_del(&page->lru); |
2884 | if (!page->active) { |
2885 | list_add_tail(&page->lru, &n->slabs_free); |
2886 | n->free_slabs++; |
2887 | } else |
2888 | list_add_tail(&page->lru, &n->slabs_partial); |
2889 | |
2890 | list_for_each_entry(page, &n->slabs_partial, lru) { |
2891 | if (!PageSlabPfmemalloc(page)) |
2892 | return page; |
2893 | } |
2894 | |
2895 | n->free_touched = 1; |
2896 | list_for_each_entry(page, &n->slabs_free, lru) { |
2897 | if (!PageSlabPfmemalloc(page)) { |
2898 | n->free_slabs--; |
2899 | return page; |
2900 | } |
2901 | } |
2902 | |
2903 | return NULL; |
2904 | } |
2905 | |
2906 | static struct page *get_first_slab(struct kmem_cache_node *n, bool pfmemalloc) |
2907 | { |
2908 | struct page *page; |
2909 | |
2910 | assert_spin_locked(&n->list_lock); |
2911 | page = list_first_entry_or_null(&n->slabs_partial, struct page, lru); |
2912 | if (!page) { |
2913 | n->free_touched = 1; |
2914 | page = list_first_entry_or_null(&n->slabs_free, struct page, |
2915 | lru); |
2916 | if (page) |
2917 | n->free_slabs--; |
2918 | } |
2919 | |
2920 | if (sk_memalloc_socks()) |
2921 | page = get_valid_first_slab(n, page, pfmemalloc); |
2922 | |
2923 | return page; |
2924 | } |
2925 | |
2926 | static noinline void *cache_alloc_pfmemalloc(struct kmem_cache *cachep, |
2927 | struct kmem_cache_node *n, gfp_t flags) |
2928 | { |
2929 | struct page *page; |
2930 | void *obj; |
2931 | void *list = NULL; |
2932 | |
2933 | if (!gfp_pfmemalloc_allowed(flags)) |
2934 | return NULL; |
2935 | |
2936 | spin_lock(&n->list_lock); |
2937 | page = get_first_slab(n, true); |
2938 | if (!page) { |
2939 | spin_unlock(&n->list_lock); |
2940 | return NULL; |
2941 | } |
2942 | |
2943 | obj = slab_get_obj(cachep, page); |
2944 | n->free_objects--; |
2945 | |
2946 | fixup_slab_list(cachep, n, page, &list); |
2947 | |
2948 | spin_unlock(&n->list_lock); |
2949 | fixup_objfreelist_debug(cachep, &list); |
2950 | |
2951 | return obj; |
2952 | } |
2953 | |
2954 | /* |
2955 | * Slab list should be fixed up by fixup_slab_list() for existing slab |
2956 | * or cache_grow_end() for new slab |
2957 | */ |
2958 | static __always_inline int alloc_block(struct kmem_cache *cachep, |
2959 | struct array_cache *ac, struct page *page, int batchcount) |
2960 | { |
2961 | /* |
2962 | * There must be at least one object available for |
2963 | * allocation. |
2964 | */ |
2965 | BUG_ON(page->active >= cachep->num); |
2966 | |
2967 | while (page->active < cachep->num && batchcount--) { |
2968 | STATS_INC_ALLOCED(cachep); |
2969 | STATS_INC_ACTIVE(cachep); |
2970 | STATS_SET_HIGH(cachep); |
2971 | |
2972 | ac->entry[ac->avail++] = slab_get_obj(cachep, page); |
2973 | } |
2974 | |
2975 | return batchcount; |
2976 | } |
2977 | |
2978 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) |
2979 | { |
2980 | int batchcount; |
2981 | struct kmem_cache_node *n; |
2982 | struct array_cache *ac, *shared; |
2983 | int node; |
2984 | void *list = NULL; |
2985 | struct page *page; |
2986 | |
2987 | check_irq_off(); |
2988 | node = numa_mem_id(); |
2989 | |
2990 | ac = cpu_cache_get(cachep); |
2991 | batchcount = ac->batchcount; |
2992 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { |
2993 | /* |
2994 | * If there was little recent activity on this cache, then |
2995 | * perform only a partial refill. Otherwise we could generate |
2996 | * refill bouncing. |
2997 | */ |
2998 | batchcount = BATCHREFILL_LIMIT; |
2999 | } |
3000 | n = get_node(cachep, node); |
3001 | |
3002 | BUG_ON(ac->avail > 0 || !n); |
3003 | shared = READ_ONCE(n->shared); |
3004 | if (!n->free_objects && (!shared || !shared->avail)) |
3005 | goto direct_grow; |
3006 | |
3007 | spin_lock(&n->list_lock); |
3008 | shared = READ_ONCE(n->shared); |
3009 | |
3010 | /* See if we can refill from the shared array */ |
3011 | if (shared && transfer_objects(ac, shared, batchcount)) { |
3012 | shared->touched = 1; |
3013 | goto alloc_done; |
3014 | } |
3015 | |
3016 | while (batchcount > 0) { |
3017 | /* Get slab alloc is to come from. */ |
3018 | page = get_first_slab(n, false); |
3019 | if (!page) |
3020 | goto must_grow; |
3021 | |
3022 | check_spinlock_acquired(cachep); |
3023 | |
3024 | batchcount = alloc_block(cachep, ac, page, batchcount); |
3025 | fixup_slab_list(cachep, n, page, &list); |
3026 | } |
3027 | |
3028 | must_grow: |
3029 | n->free_objects -= ac->avail; |
3030 | alloc_done: |
3031 | spin_unlock(&n->list_lock); |
3032 | fixup_objfreelist_debug(cachep, &list); |
3033 | |
3034 | direct_grow: |
3035 | if (unlikely(!ac->avail)) { |
3036 | /* Check if we can use obj in pfmemalloc slab */ |
3037 | if (sk_memalloc_socks()) { |
3038 | void *obj = cache_alloc_pfmemalloc(cachep, n, flags); |
3039 | |
3040 | if (obj) |
3041 | return obj; |
3042 | } |
3043 | |
3044 | page = cache_grow_begin(cachep, gfp_exact_node(flags), node); |
3045 | |
3046 | /* |
3047 | * cache_grow_begin() can reenable interrupts, |
3048 | * then ac could change. |
3049 | */ |
3050 | ac = cpu_cache_get(cachep); |
3051 | if (!ac->avail && page) |
3052 | alloc_block(cachep, ac, page, batchcount); |
3053 | cache_grow_end(cachep, page); |
3054 | |
3055 | if (!ac->avail) |
3056 | return NULL; |
3057 | } |
3058 | ac->touched = 1; |
3059 | |
3060 | return ac->entry[--ac->avail]; |
3061 | } |
3062 | |
3063 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, |
3064 | gfp_t flags) |
3065 | { |
3066 | might_sleep_if(gfpflags_allow_blocking(flags)); |
3067 | } |
3068 | |
3069 | #if DEBUG |
3070 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, |
3071 | gfp_t flags, void *objp, unsigned long caller) |
3072 | { |
3073 | WARN_ON_ONCE(cachep->ctor && (flags & __GFP_ZERO)); |
3074 | if (!objp) |
3075 | return objp; |
3076 | if (cachep->flags & SLAB_POISON) { |
3077 | check_poison_obj(cachep, objp); |
3078 | slab_kernel_map(cachep, objp, 1, 0); |
3079 | poison_obj(cachep, objp, POISON_INUSE); |
3080 | } |
3081 | if (cachep->flags & SLAB_STORE_USER) |
3082 | *dbg_userword(cachep, objp) = (void *)caller; |
3083 | |
3084 | if (cachep->flags & SLAB_RED_ZONE) { |
3085 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || |
3086 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { |
3087 | slab_error(cachep, "double free, or memory outside object was overwritten"); |
3088 | pr_err("%px: redzone 1:0x%llx, redzone 2:0x%llx\n", |
3089 | objp, *dbg_redzone1(cachep, objp), |
3090 | *dbg_redzone2(cachep, objp)); |
3091 | } |
3092 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; |
3093 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; |
3094 | } |
3095 | |
3096 | objp += obj_offset(cachep); |
3097 | if (cachep->ctor && cachep->flags & SLAB_POISON) |
3098 | cachep->ctor(objp); |
3099 | if (ARCH_SLAB_MINALIGN && |
3100 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { |
3101 | pr_err("0x%px: not aligned to ARCH_SLAB_MINALIGN=%d\n", |
3102 | objp, (int)ARCH_SLAB_MINALIGN); |
3103 | } |
3104 | return objp; |
3105 | } |
3106 | #else |
3107 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) |
3108 | #endif |
3109 | |
3110 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3111 | { |
3112 | void *objp; |
3113 | struct array_cache *ac; |
3114 | |
3115 | check_irq_off(); |
3116 | |
3117 | ac = cpu_cache_get(cachep); |
3118 | if (likely(ac->avail)) { |
3119 | ac->touched = 1; |
3120 | objp = ac->entry[--ac->avail]; |
3121 | |
3122 | STATS_INC_ALLOCHIT(cachep); |
3123 | goto out; |
3124 | } |
3125 | |
3126 | STATS_INC_ALLOCMISS(cachep); |
3127 | objp = cache_alloc_refill(cachep, flags); |
3128 | /* |
3129 | * the 'ac' may be updated by cache_alloc_refill(), |
3130 | * and kmemleak_erase() requires its correct value. |
3131 | */ |
3132 | ac = cpu_cache_get(cachep); |
3133 | |
3134 | out: |
3135 | /* |
3136 | * To avoid a false negative, if an object that is in one of the |
3137 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't |
3138 | * treat the array pointers as a reference to the object. |
3139 | */ |
3140 | if (objp) |
3141 | kmemleak_erase(&ac->entry[ac->avail]); |
3142 | return objp; |
3143 | } |
3144 | |
3145 | #ifdef CONFIG_NUMA |
3146 | /* |
3147 | * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set. |
3148 | * |
3149 | * If we are in_interrupt, then process context, including cpusets and |
3150 | * mempolicy, may not apply and should not be used for allocation policy. |
3151 | */ |
3152 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) |
3153 | { |
3154 | int nid_alloc, nid_here; |
3155 | |
3156 | if (in_interrupt() || (flags & __GFP_THISNODE)) |
3157 | return NULL; |
3158 | nid_alloc = nid_here = numa_mem_id(); |
3159 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) |
3160 | nid_alloc = cpuset_slab_spread_node(); |
3161 | else if (current->mempolicy) |
3162 | nid_alloc = mempolicy_slab_node(); |
3163 | if (nid_alloc != nid_here) |
3164 | return ____cache_alloc_node(cachep, flags, nid_alloc); |
3165 | return NULL; |
3166 | } |
3167 | |
3168 | /* |
3169 | * Fallback function if there was no memory available and no objects on a |
3170 | * certain node and fall back is permitted. First we scan all the |
3171 | * available node for available objects. If that fails then we |
3172 | * perform an allocation without specifying a node. This allows the page |
3173 | * allocator to do its reclaim / fallback magic. We then insert the |
3174 | * slab into the proper nodelist and then allocate from it. |
3175 | */ |
3176 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) |
3177 | { |
3178 | struct zonelist *zonelist; |
3179 | struct zoneref *z; |
3180 | struct zone *zone; |
3181 | enum zone_type high_zoneidx = gfp_zone(flags); |
3182 | void *obj = NULL; |
3183 | struct page *page; |
3184 | int nid; |
3185 | unsigned int cpuset_mems_cookie; |
3186 | |
3187 | if (flags & __GFP_THISNODE) |
3188 | return NULL; |
3189 | |
3190 | retry_cpuset: |
3191 | cpuset_mems_cookie = read_mems_allowed_begin(); |
3192 | zonelist = node_zonelist(mempolicy_slab_node(), flags); |
3193 | |
3194 | retry: |
3195 | /* |
3196 | * Look through allowed nodes for objects available |
3197 | * from existing per node queues. |
3198 | */ |
3199 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { |
3200 | nid = zone_to_nid(zone); |
3201 | |
3202 | if (cpuset_zone_allowed(zone, flags) && |
3203 | get_node(cache, nid) && |
3204 | get_node(cache, nid)->free_objects) { |
3205 | obj = ____cache_alloc_node(cache, |
3206 | gfp_exact_node(flags), nid); |
3207 | if (obj) |
3208 | break; |
3209 | } |
3210 | } |
3211 | |
3212 | if (!obj) { |
3213 | /* |
3214 | * This allocation will be performed within the constraints |
3215 | * of the current cpuset / memory policy requirements. |
3216 | * We may trigger various forms of reclaim on the allowed |
3217 | * set and go into memory reserves if necessary. |
3218 | */ |
3219 | page = cache_grow_begin(cache, flags, numa_mem_id()); |
3220 | cache_grow_end(cache, page); |
3221 | if (page) { |
3222 | nid = page_to_nid(page); |
3223 | obj = ____cache_alloc_node(cache, |
3224 | gfp_exact_node(flags), nid); |
3225 | |
3226 | /* |
3227 | * Another processor may allocate the objects in |
3228 | * the slab since we are not holding any locks. |
3229 | */ |
3230 | if (!obj) |
3231 | goto retry; |
3232 | } |
3233 | } |
3234 | |
3235 | if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie))) |
3236 | goto retry_cpuset; |
3237 | return obj; |
3238 | } |
3239 | |
3240 | /* |
3241 | * A interface to enable slab creation on nodeid |
3242 | */ |
3243 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, |
3244 | int nodeid) |
3245 | { |
3246 | struct page *page; |
3247 | struct kmem_cache_node *n; |
3248 | void *obj = NULL; |
3249 | void *list = NULL; |
3250 | |
3251 | VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES); |
3252 | n = get_node(cachep, nodeid); |
3253 | BUG_ON(!n); |
3254 | |
3255 | check_irq_off(); |
3256 | spin_lock(&n->list_lock); |
3257 | page = get_first_slab(n, false); |
3258 | if (!page) |
3259 | goto must_grow; |
3260 | |
3261 | check_spinlock_acquired_node(cachep, nodeid); |
3262 | |
3263 | STATS_INC_NODEALLOCS(cachep); |
3264 | STATS_INC_ACTIVE(cachep); |
3265 | STATS_SET_HIGH(cachep); |
3266 | |
3267 | BUG_ON(page->active == cachep->num); |
3268 | |
3269 | obj = slab_get_obj(cachep, page); |
3270 | n->free_objects--; |
3271 | |
3272 | fixup_slab_list(cachep, n, page, &list); |
3273 | |
3274 | spin_unlock(&n->list_lock); |
3275 | fixup_objfreelist_debug(cachep, &list); |
3276 | return obj; |
3277 | |
3278 | must_grow: |
3279 | spin_unlock(&n->list_lock); |
3280 | page = cache_grow_begin(cachep, gfp_exact_node(flags), nodeid); |
3281 | if (page) { |
3282 | /* This slab isn't counted yet so don't update free_objects */ |
3283 | obj = slab_get_obj(cachep, page); |
3284 | } |
3285 | cache_grow_end(cachep, page); |
3286 | |
3287 | return obj ? obj : fallback_alloc(cachep, flags); |
3288 | } |
3289 | |
3290 | static __always_inline void * |
3291 | slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, |
3292 | unsigned long caller) |
3293 | { |
3294 | unsigned long save_flags; |
3295 | void *ptr; |
3296 | int slab_node = numa_mem_id(); |
3297 | |
3298 | flags &= gfp_allowed_mask; |
3299 | cachep = slab_pre_alloc_hook(cachep, flags); |
3300 | if (unlikely(!cachep)) |
3301 | return NULL; |
3302 | |
3303 | cache_alloc_debugcheck_before(cachep, flags); |
3304 | local_irq_save(save_flags); |
3305 | |
3306 | if (nodeid == NUMA_NO_NODE) |
3307 | nodeid = slab_node; |
3308 | |
3309 | if (unlikely(!get_node(cachep, nodeid))) { |
3310 | /* Node not bootstrapped yet */ |
3311 | ptr = fallback_alloc(cachep, flags); |
3312 | goto out; |
3313 | } |
3314 | |
3315 | if (nodeid == slab_node) { |
3316 | /* |
3317 | * Use the locally cached objects if possible. |
3318 | * However ____cache_alloc does not allow fallback |
3319 | * to other nodes. It may fail while we still have |
3320 | * objects on other nodes available. |
3321 | */ |
3322 | ptr = ____cache_alloc(cachep, flags); |
3323 | if (ptr) |
3324 | goto out; |
3325 | } |
3326 | /* ___cache_alloc_node can fall back to other nodes */ |
3327 | ptr = ____cache_alloc_node(cachep, flags, nodeid); |
3328 | out: |
3329 | local_irq_restore(save_flags); |
3330 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); |
3331 | |
3332 | if (unlikely(flags & __GFP_ZERO) && ptr) |
3333 | memset(ptr, 0, cachep->object_size); |
3334 | |
3335 | slab_post_alloc_hook(cachep, flags, 1, &ptr); |
3336 | return ptr; |
3337 | } |
3338 | |
3339 | static __always_inline void * |
3340 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) |
3341 | { |
3342 | void *objp; |
3343 | |
3344 | if (current->mempolicy || cpuset_do_slab_mem_spread()) { |
3345 | objp = alternate_node_alloc(cache, flags); |
3346 | if (objp) |
3347 | goto out; |
3348 | } |
3349 | objp = ____cache_alloc(cache, flags); |
3350 | |
3351 | /* |
3352 | * We may just have run out of memory on the local node. |
3353 | * ____cache_alloc_node() knows how to locate memory on other nodes |
3354 | */ |
3355 | if (!objp) |
3356 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); |
3357 | |
3358 | out: |
3359 | return objp; |
3360 | } |
3361 | #else |
3362 | |
3363 | static __always_inline void * |
3364 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3365 | { |
3366 | return ____cache_alloc(cachep, flags); |
3367 | } |
3368 | |
3369 | #endif /* CONFIG_NUMA */ |
3370 | |
3371 | static __always_inline void * |
3372 | slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) |
3373 | { |
3374 | unsigned long save_flags; |
3375 | void *objp; |
3376 | |
3377 | flags &= gfp_allowed_mask; |
3378 | cachep = slab_pre_alloc_hook(cachep, flags); |
3379 | if (unlikely(!cachep)) |
3380 | return NULL; |
3381 | |
3382 | cache_alloc_debugcheck_before(cachep, flags); |
3383 | local_irq_save(save_flags); |
3384 | objp = __do_cache_alloc(cachep, flags); |
3385 | local_irq_restore(save_flags); |
3386 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); |
3387 | prefetchw(objp); |
3388 | |
3389 | if (unlikely(flags & __GFP_ZERO) && objp) |
3390 | memset(objp, 0, cachep->object_size); |
3391 | |
3392 | slab_post_alloc_hook(cachep, flags, 1, &objp); |
3393 | return objp; |
3394 | } |
3395 | |
3396 | /* |
3397 | * Caller needs to acquire correct kmem_cache_node's list_lock |
3398 | * @list: List of detached free slabs should be freed by caller |
3399 | */ |
3400 | static void free_block(struct kmem_cache *cachep, void **objpp, |
3401 | int nr_objects, int node, struct list_head *list) |
3402 | { |
3403 | int i; |
3404 | struct kmem_cache_node *n = get_node(cachep, node); |
3405 | struct page *page; |
3406 | |
3407 | n->free_objects += nr_objects; |
3408 | |
3409 | for (i = 0; i < nr_objects; i++) { |
3410 | void *objp; |
3411 | struct page *page; |
3412 | |
3413 | objp = objpp[i]; |
3414 | |
3415 | page = virt_to_head_page(objp); |
3416 | list_del(&page->lru); |
3417 | check_spinlock_acquired_node(cachep, node); |
3418 | slab_put_obj(cachep, page, objp); |
3419 | STATS_DEC_ACTIVE(cachep); |
3420 | |
3421 | /* fixup slab chains */ |
3422 | if (page->active == 0) { |
3423 | list_add(&page->lru, &n->slabs_free); |
3424 | n->free_slabs++; |
3425 | } else { |
3426 | /* Unconditionally move a slab to the end of the |
3427 | * partial list on free - maximum time for the |
3428 | * other objects to be freed, too. |
3429 | */ |
3430 | list_add_tail(&page->lru, &n->slabs_partial); |
3431 | } |
3432 | } |
3433 | |
3434 | while (n->free_objects > n->free_limit && !list_empty(&n->slabs_free)) { |
3435 | n->free_objects -= cachep->num; |
3436 | |
3437 | page = list_last_entry(&n->slabs_free, struct page, lru); |
3438 | list_move(&page->lru, list); |
3439 | n->free_slabs--; |
3440 | n->total_slabs--; |
3441 | } |
3442 | } |
3443 | |
3444 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) |
3445 | { |
3446 | int batchcount; |
3447 | struct kmem_cache_node *n; |
3448 | int node = numa_mem_id(); |
3449 | LIST_HEAD(list); |
3450 | |
3451 | batchcount = ac->batchcount; |
3452 | |
3453 | check_irq_off(); |
3454 | n = get_node(cachep, node); |
3455 | spin_lock(&n->list_lock); |
3456 | if (n->shared) { |
3457 | struct array_cache *shared_array = n->shared; |
3458 | int max = shared_array->limit - shared_array->avail; |
3459 | if (max) { |
3460 | if (batchcount > max) |
3461 | batchcount = max; |
3462 | memcpy(&(shared_array->entry[shared_array->avail]), |
3463 | ac->entry, sizeof(void *) * batchcount); |
3464 | shared_array->avail += batchcount; |
3465 | goto free_done; |
3466 | } |
3467 | } |
3468 | |
3469 | free_block(cachep, ac->entry, batchcount, node, &list); |
3470 | free_done: |
3471 | #if STATS |
3472 | { |
3473 | int i = 0; |
3474 | struct page *page; |
3475 | |
3476 | list_for_each_entry(page, &n->slabs_free, lru) { |
3477 | BUG_ON(page->active); |
3478 | |
3479 | i++; |
3480 | } |
3481 | STATS_SET_FREEABLE(cachep, i); |
3482 | } |
3483 | #endif |
3484 | spin_unlock(&n->list_lock); |
3485 | slabs_destroy(cachep, &list); |
3486 | ac->avail -= batchcount; |
3487 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); |
3488 | } |
3489 | |
3490 | /* |
3491 | * Release an obj back to its cache. If the obj has a constructed state, it must |
3492 | * be in this state _before_ it is released. Called with disabled ints. |
3493 | */ |
3494 | static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp, |
3495 | unsigned long caller) |
3496 | { |
3497 | /* Put the object into the quarantine, don't touch it for now. */ |
3498 | if (kasan_slab_free(cachep, objp, _RET_IP_)) |
3499 | return; |
3500 | |
3501 | ___cache_free(cachep, objp, caller); |
3502 | } |
3503 | |
3504 | void ___cache_free(struct kmem_cache *cachep, void *objp, |
3505 | unsigned long caller) |
3506 | { |
3507 | struct array_cache *ac = cpu_cache_get(cachep); |
3508 | |
3509 | check_irq_off(); |
3510 | kmemleak_free_recursive(objp, cachep->flags); |
3511 | objp = cache_free_debugcheck(cachep, objp, caller); |
3512 | |
3513 | /* |
3514 | * Skip calling cache_free_alien() when the platform is not numa. |
3515 | * This will avoid cache misses that happen while accessing slabp (which |
3516 | * is per page memory reference) to get nodeid. Instead use a global |
3517 | * variable to skip the call, which is mostly likely to be present in |
3518 | * the cache. |
3519 | */ |
3520 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) |
3521 | return; |
3522 | |
3523 | if (ac->avail < ac->limit) { |
3524 | STATS_INC_FREEHIT(cachep); |
3525 | } else { |
3526 | STATS_INC_FREEMISS(cachep); |
3527 | cache_flusharray(cachep, ac); |
3528 | } |
3529 | |
3530 | if (sk_memalloc_socks()) { |
3531 | struct page *page = virt_to_head_page(objp); |
3532 | |
3533 | if (unlikely(PageSlabPfmemalloc(page))) { |
3534 | cache_free_pfmemalloc(cachep, page, objp); |
3535 | return; |
3536 | } |
3537 | } |
3538 | |
3539 | ac->entry[ac->avail++] = objp; |
3540 | } |
3541 | |
3542 | /** |
3543 | * kmem_cache_alloc - Allocate an object |
3544 | * @cachep: The cache to allocate from. |
3545 | * @flags: See kmalloc(). |
3546 | * |
3547 | * Allocate an object from this cache. The flags are only relevant |
3548 | * if the cache has no available objects. |
3549 | * |
3550 | * Return: pointer to the new object or %NULL in case of error |
3551 | */ |
3552 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) |
3553 | { |
3554 | void *ret = slab_alloc(cachep, flags, _RET_IP_); |
3555 | |
3556 | trace_kmem_cache_alloc(_RET_IP_, ret, |
3557 | cachep->object_size, cachep->size, flags); |
3558 | |
3559 | return ret; |
3560 | } |
3561 | EXPORT_SYMBOL(kmem_cache_alloc); |
3562 | |
3563 | static __always_inline void |
3564 | cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags, |
3565 | size_t size, void **p, unsigned long caller) |
3566 | { |
3567 | size_t i; |
3568 | |
3569 | for (i = 0; i < size; i++) |
3570 | p[i] = cache_alloc_debugcheck_after(s, flags, p[i], caller); |
3571 | } |
3572 | |
3573 | int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, |
3574 | void **p) |
3575 | { |
3576 | size_t i; |
3577 | |
3578 | s = slab_pre_alloc_hook(s, flags); |
3579 | if (!s) |
3580 | return 0; |
3581 | |
3582 | cache_alloc_debugcheck_before(s, flags); |
3583 | |
3584 | local_irq_disable(); |
3585 | for (i = 0; i < size; i++) { |
3586 | void *objp = __do_cache_alloc(s, flags); |
3587 | |
3588 | if (unlikely(!objp)) |
3589 | goto error; |
3590 | p[i] = objp; |
3591 | } |
3592 | local_irq_enable(); |
3593 | |
3594 | cache_alloc_debugcheck_after_bulk(s, flags, size, p, _RET_IP_); |
3595 | |
3596 | /* Clear memory outside IRQ disabled section */ |
3597 | if (unlikely(flags & __GFP_ZERO)) |
3598 | for (i = 0; i < size; i++) |
3599 | memset(p[i], 0, s->object_size); |
3600 | |
3601 | slab_post_alloc_hook(s, flags, size, p); |
3602 | /* FIXME: Trace call missing. Christoph would like a bulk variant */ |
3603 | return size; |
3604 | error: |
3605 | local_irq_enable(); |
3606 | cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_); |
3607 | slab_post_alloc_hook(s, flags, i, p); |
3608 | __kmem_cache_free_bulk(s, i, p); |
3609 | return 0; |
3610 | } |
3611 | EXPORT_SYMBOL(kmem_cache_alloc_bulk); |
3612 | |
3613 | #ifdef CONFIG_TRACING |
3614 | void * |
3615 | kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) |
3616 | { |
3617 | void *ret; |
3618 | |
3619 | ret = slab_alloc(cachep, flags, _RET_IP_); |
3620 | |
3621 | ret = kasan_kmalloc(cachep, ret, size, flags); |
3622 | trace_kmalloc(_RET_IP_, ret, |
3623 | size, cachep->size, flags); |
3624 | return ret; |
3625 | } |
3626 | EXPORT_SYMBOL(kmem_cache_alloc_trace); |
3627 | #endif |
3628 | |
3629 | #ifdef CONFIG_NUMA |
3630 | /** |
3631 | * kmem_cache_alloc_node - Allocate an object on the specified node |
3632 | * @cachep: The cache to allocate from. |
3633 | * @flags: See kmalloc(). |
3634 | * @nodeid: node number of the target node. |
3635 | * |
3636 | * Identical to kmem_cache_alloc but it will allocate memory on the given |
3637 | * node, which can improve the performance for cpu bound structures. |
3638 | * |
3639 | * Fallback to other node is possible if __GFP_THISNODE is not set. |
3640 | * |
3641 | * Return: pointer to the new object or %NULL in case of error |
3642 | */ |
3643 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) |
3644 | { |
3645 | void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3646 | |
3647 | trace_kmem_cache_alloc_node(_RET_IP_, ret, |
3648 | cachep->object_size, cachep->size, |
3649 | flags, nodeid); |
3650 | |
3651 | return ret; |
3652 | } |
3653 | EXPORT_SYMBOL(kmem_cache_alloc_node); |
3654 | |
3655 | #ifdef CONFIG_TRACING |
3656 | void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, |
3657 | gfp_t flags, |
3658 | int nodeid, |
3659 | size_t size) |
3660 | { |
3661 | void *ret; |
3662 | |
3663 | ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); |
3664 | |
3665 | ret = kasan_kmalloc(cachep, ret, size, flags); |
3666 | trace_kmalloc_node(_RET_IP_, ret, |
3667 | size, cachep->size, |
3668 | flags, nodeid); |
3669 | return ret; |
3670 | } |
3671 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); |
3672 | #endif |
3673 | |
3674 | static __always_inline void * |
3675 | __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) |
3676 | { |
3677 | struct kmem_cache *cachep; |
3678 | void *ret; |
3679 | |
3680 | if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) |
3681 | return NULL; |
3682 | cachep = kmalloc_slab(size, flags); |
3683 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3684 | return cachep; |
3685 | ret = kmem_cache_alloc_node_trace(cachep, flags, node, size); |
3686 | ret = kasan_kmalloc(cachep, ret, size, flags); |
3687 | |
3688 | return ret; |
3689 | } |
3690 | |
3691 | void *__kmalloc_node(size_t size, gfp_t flags, int node) |
3692 | { |
3693 | return __do_kmalloc_node(size, flags, node, _RET_IP_); |
3694 | } |
3695 | EXPORT_SYMBOL(__kmalloc_node); |
3696 | |
3697 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, |
3698 | int node, unsigned long caller) |
3699 | { |
3700 | return __do_kmalloc_node(size, flags, node, caller); |
3701 | } |
3702 | EXPORT_SYMBOL(__kmalloc_node_track_caller); |
3703 | #endif /* CONFIG_NUMA */ |
3704 | |
3705 | /** |
3706 | * __do_kmalloc - allocate memory |
3707 | * @size: how many bytes of memory are required. |
3708 | * @flags: the type of memory to allocate (see kmalloc). |
3709 | * @caller: function caller for debug tracking of the caller |
3710 | * |
3711 | * Return: pointer to the allocated memory or %NULL in case of error |
3712 | */ |
3713 | static __always_inline void *__do_kmalloc(size_t size, gfp_t flags, |
3714 | unsigned long caller) |
3715 | { |
3716 | struct kmem_cache *cachep; |
3717 | void *ret; |
3718 | |
3719 | if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) |
3720 | return NULL; |
3721 | cachep = kmalloc_slab(size, flags); |
3722 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) |
3723 | return cachep; |
3724 | ret = slab_alloc(cachep, flags, caller); |
3725 | |
3726 | ret = kasan_kmalloc(cachep, ret, size, flags); |
3727 | trace_kmalloc(caller, ret, |
3728 | size, cachep->size, flags); |
3729 | |
3730 | return ret; |
3731 | } |
3732 | |
3733 | void *__kmalloc(size_t size, gfp_t flags) |
3734 | { |
3735 | return __do_kmalloc(size, flags, _RET_IP_); |
3736 | } |
3737 | EXPORT_SYMBOL(__kmalloc); |
3738 | |
3739 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) |
3740 | { |
3741 | return __do_kmalloc(size, flags, caller); |
3742 | } |
3743 | EXPORT_SYMBOL(__kmalloc_track_caller); |
3744 | |
3745 | /** |
3746 | * kmem_cache_free - Deallocate an object |
3747 | * @cachep: The cache the allocation was from. |
3748 | * @objp: The previously allocated object. |
3749 | * |
3750 | * Free an object which was previously allocated from this |
3751 | * cache. |
3752 | */ |
3753 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) |
3754 | { |
3755 | unsigned long flags; |
3756 | cachep = cache_from_obj(cachep, objp); |
3757 | if (!cachep) |
3758 | return; |
3759 | |
3760 | local_irq_save(flags); |
3761 | debug_check_no_locks_freed(objp, cachep->object_size); |
3762 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) |
3763 | debug_check_no_obj_freed(objp, cachep->object_size); |
3764 | __cache_free(cachep, objp, _RET_IP_); |
3765 | local_irq_restore(flags); |
3766 | |
3767 | trace_kmem_cache_free(_RET_IP_, objp); |
3768 | } |
3769 | EXPORT_SYMBOL(kmem_cache_free); |
3770 | |
3771 | void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p) |
3772 | { |
3773 | struct kmem_cache *s; |
3774 | size_t i; |
3775 | |
3776 | local_irq_disable(); |
3777 | for (i = 0; i < size; i++) { |
3778 | void *objp = p[i]; |
3779 | |
3780 | if (!orig_s) /* called via kfree_bulk */ |
3781 | s = virt_to_cache(objp); |
3782 | else |
3783 | s = cache_from_obj(orig_s, objp); |
3784 | |
3785 | debug_check_no_locks_freed(objp, s->object_size); |
3786 | if (!(s->flags & SLAB_DEBUG_OBJECTS)) |
3787 | debug_check_no_obj_freed(objp, s->object_size); |
3788 | |
3789 | __cache_free(s, objp, _RET_IP_); |
3790 | } |
3791 | local_irq_enable(); |
3792 | |
3793 | /* FIXME: add tracing */ |
3794 | } |
3795 | EXPORT_SYMBOL(kmem_cache_free_bulk); |
3796 | |
3797 | /** |
3798 | * kfree - free previously allocated memory |
3799 | * @objp: pointer returned by kmalloc. |
3800 | * |
3801 | * If @objp is NULL, no operation is performed. |
3802 | * |
3803 | * Don't free memory not originally allocated by kmalloc() |
3804 | * or you will run into trouble. |
3805 | */ |
3806 | void kfree(const void *objp) |
3807 | { |
3808 | struct kmem_cache *c; |
3809 | unsigned long flags; |
3810 | |
3811 | trace_kfree(_RET_IP_, objp); |
3812 | |
3813 | if (unlikely(ZERO_OR_NULL_PTR(objp))) |
3814 | return; |
3815 | local_irq_save(flags); |
3816 | kfree_debugcheck(objp); |
3817 | c = virt_to_cache(objp); |
3818 | debug_check_no_locks_freed(objp, c->object_size); |
3819 | |
3820 | debug_check_no_obj_freed(objp, c->object_size); |
3821 | __cache_free(c, (void *)objp, _RET_IP_); |
3822 | local_irq_restore(flags); |
3823 | } |
3824 | EXPORT_SYMBOL(kfree); |
3825 | |
3826 | /* |
3827 | * This initializes kmem_cache_node or resizes various caches for all nodes. |
3828 | */ |
3829 | static int setup_kmem_cache_nodes(struct kmem_cache *cachep, gfp_t gfp) |
3830 | { |
3831 | int ret; |
3832 | int node; |
3833 | struct kmem_cache_node *n; |
3834 | |
3835 | for_each_online_node(node) { |
3836 | ret = setup_kmem_cache_node(cachep, node, gfp, true); |
3837 | if (ret) |
3838 | goto fail; |
3839 | |
3840 | } |
3841 | |
3842 | return 0; |
3843 | |
3844 | fail: |
3845 | if (!cachep->list.next) { |
3846 | /* Cache is not active yet. Roll back what we did */ |
3847 | node--; |
3848 | while (node >= 0) { |
3849 | n = get_node(cachep, node); |
3850 | if (n) { |
3851 | kfree(n->shared); |
3852 | free_alien_cache(n->alien); |
3853 | kfree(n); |
3854 | cachep->node[node] = NULL; |
3855 | } |
3856 | node--; |
3857 | } |
3858 | } |
3859 | return -ENOMEM; |
3860 | } |
3861 | |
3862 | /* Always called with the slab_mutex held */ |
3863 | static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3864 | int batchcount, int shared, gfp_t gfp) |
3865 | { |
3866 | struct array_cache __percpu *cpu_cache, *prev; |
3867 | int cpu; |
3868 | |
3869 | cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount); |
3870 | if (!cpu_cache) |
3871 | return -ENOMEM; |
3872 | |
3873 | prev = cachep->cpu_cache; |
3874 | cachep->cpu_cache = cpu_cache; |
3875 | /* |
3876 | * Without a previous cpu_cache there's no need to synchronize remote |
3877 | * cpus, so skip the IPIs. |
3878 | */ |
3879 | if (prev) |
3880 | kick_all_cpus_sync(); |
3881 | |
3882 | check_irq_on(); |
3883 | cachep->batchcount = batchcount; |
3884 | cachep->limit = limit; |
3885 | cachep->shared = shared; |
3886 | |
3887 | if (!prev) |
3888 | goto setup_node; |
3889 | |
3890 | for_each_online_cpu(cpu) { |
3891 | LIST_HEAD(list); |
3892 | int node; |
3893 | struct kmem_cache_node *n; |
3894 | struct array_cache *ac = per_cpu_ptr(prev, cpu); |
3895 | |
3896 | node = cpu_to_mem(cpu); |
3897 | n = get_node(cachep, node); |
3898 | spin_lock_irq(&n->list_lock); |
3899 | free_block(cachep, ac->entry, ac->avail, node, &list); |
3900 | spin_unlock_irq(&n->list_lock); |
3901 | slabs_destroy(cachep, &list); |
3902 | } |
3903 | free_percpu(prev); |
3904 | |
3905 | setup_node: |
3906 | return setup_kmem_cache_nodes(cachep, gfp); |
3907 | } |
3908 | |
3909 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, |
3910 | int batchcount, int shared, gfp_t gfp) |
3911 | { |
3912 | int ret; |
3913 | struct kmem_cache *c; |
3914 | |
3915 | ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
3916 | |
3917 | if (slab_state < FULL) |
3918 | return ret; |
3919 | |
3920 | if ((ret < 0) || !is_root_cache(cachep)) |
3921 | return ret; |
3922 | |
3923 | lockdep_assert_held(&slab_mutex); |
3924 | for_each_memcg_cache(c, cachep) { |
3925 | /* return value determined by the root cache only */ |
3926 | __do_tune_cpucache(c, limit, batchcount, shared, gfp); |
3927 | } |
3928 | |
3929 | return ret; |
3930 | } |
3931 | |
3932 | /* Called with slab_mutex held always */ |
3933 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) |
3934 | { |
3935 | int err; |
3936 | int limit = 0; |
3937 | int shared = 0; |
3938 | int batchcount = 0; |
3939 | |
3940 | err = cache_random_seq_create(cachep, cachep->num, gfp); |
3941 | if (err) |
3942 | goto end; |
3943 | |
3944 | if (!is_root_cache(cachep)) { |
3945 | struct kmem_cache *root = memcg_root_cache(cachep); |
3946 | limit = root->limit; |
3947 | shared = root->shared; |
3948 | batchcount = root->batchcount; |
3949 | } |
3950 | |
3951 | if (limit && shared && batchcount) |
3952 | goto skip_setup; |
3953 | /* |
3954 | * The head array serves three purposes: |
3955 | * - create a LIFO ordering, i.e. return objects that are cache-warm |
3956 | * - reduce the number of spinlock operations. |
3957 | * - reduce the number of linked list operations on the slab and |
3958 | * bufctl chains: array operations are cheaper. |
3959 | * The numbers are guessed, we should auto-tune as described by |
3960 | * Bonwick. |
3961 | */ |
3962 | if (cachep->size > 131072) |
3963 | limit = 1; |
3964 | else if (cachep->size > PAGE_SIZE) |
3965 | limit = 8; |
3966 | else if (cachep->size > 1024) |
3967 | limit = 24; |
3968 | else if (cachep->size > 256) |
3969 | limit = 54; |
3970 | else |
3971 | limit = 120; |
3972 | |
3973 | /* |
3974 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound |
3975 | * allocation behaviour: Most allocs on one cpu, most free operations |
3976 | * on another cpu. For these cases, an efficient object passing between |
3977 | * cpus is necessary. This is provided by a shared array. The array |
3978 | * replaces Bonwick's magazine layer. |
3979 | * On uniprocessor, it's functionally equivalent (but less efficient) |
3980 | * to a larger limit. Thus disabled by default. |
3981 | */ |
3982 | shared = 0; |
3983 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) |
3984 | shared = 8; |
3985 | |
3986 | #if DEBUG |
3987 | /* |
3988 | * With debugging enabled, large batchcount lead to excessively long |
3989 | * periods with disabled local interrupts. Limit the batchcount |
3990 | */ |
3991 | if (limit > 32) |
3992 | limit = 32; |
3993 | #endif |
3994 | batchcount = (limit + 1) / 2; |
3995 | skip_setup: |
3996 | err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); |
3997 | end: |
3998 | if (err) |
3999 | pr_err("enable_cpucache failed for %s, error %d\n", |
4000 | cachep->name, -err); |
4001 | return err; |
4002 | } |
4003 | |
4004 | /* |
4005 | * Drain an array if it contains any elements taking the node lock only if |
4006 | * necessary. Note that the node listlock also protects the array_cache |
4007 | * if drain_array() is used on the shared array. |
4008 | */ |
4009 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, |
4010 | struct array_cache *ac, int node) |
4011 | { |
4012 | LIST_HEAD(list); |
4013 | |
4014 | /* ac from n->shared can be freed if we don't hold the slab_mutex. */ |
4015 | check_mutex_acquired(); |
4016 | |
4017 | if (!ac || !ac->avail) |
4018 | return; |
4019 | |
4020 | if (ac->touched) { |
4021 | ac->touched = 0; |
4022 | return; |
4023 | } |
4024 | |
4025 | spin_lock_irq(&n->list_lock); |
4026 | drain_array_locked(cachep, ac, node, false, &list); |
4027 | spin_unlock_irq(&n->list_lock); |
4028 | |
4029 | slabs_destroy(cachep, &list); |
4030 | } |
4031 | |
4032 | /** |
4033 | * cache_reap - Reclaim memory from caches. |
4034 | * @w: work descriptor |
4035 | * |
4036 | * Called from workqueue/eventd every few seconds. |
4037 | * Purpose: |
4038 | * - clear the per-cpu caches for this CPU. |
4039 | * - return freeable pages to the main free memory pool. |
4040 | * |
4041 | * If we cannot acquire the cache chain mutex then just give up - we'll try |
4042 | * again on the next iteration. |
4043 | */ |
4044 | static void cache_reap(struct work_struct *w) |
4045 | { |
4046 | struct kmem_cache *searchp; |
4047 | struct kmem_cache_node *n; |
4048 | int node = numa_mem_id(); |
4049 | struct delayed_work *work = to_delayed_work(w); |
4050 | |
4051 | if (!mutex_trylock(&slab_mutex)) |
4052 | /* Give up. Setup the next iteration. */ |
4053 | goto out; |
4054 | |
4055 | list_for_each_entry(searchp, &slab_caches, list) { |
4056 | check_irq_on(); |
4057 | |
4058 | /* |
4059 | * We only take the node lock if absolutely necessary and we |
4060 | * have established with reasonable certainty that |
4061 | * we can do some work if the lock was obtained. |
4062 | */ |
4063 | n = get_node(searchp, node); |
4064 | |
4065 | reap_alien(searchp, n); |
4066 | |
4067 | drain_array(searchp, n, cpu_cache_get(searchp), node); |
4068 | |
4069 | /* |
4070 | * These are racy checks but it does not matter |
4071 | * if we skip one check or scan twice. |
4072 | */ |
4073 | if (time_after(n->next_reap, jiffies)) |
4074 | goto next; |
4075 | |
4076 | n->next_reap = jiffies + REAPTIMEOUT_NODE; |
4077 | |
4078 | drain_array(searchp, n, n->shared, node); |
4079 | |
4080 | if (n->free_touched) |
4081 | n->free_touched = 0; |
4082 | else { |
4083 | int freed; |
4084 | |
4085 | freed = drain_freelist(searchp, n, (n->free_limit + |
4086 | 5 * searchp->num - 1) / (5 * searchp->num)); |
4087 | STATS_ADD_REAPED(searchp, freed); |
4088 | } |
4089 | next: |
4090 | cond_resched(); |
4091 | } |
4092 | check_irq_on(); |
4093 | mutex_unlock(&slab_mutex); |
4094 | next_reap_node(); |
4095 | out: |
4096 | /* Set up the next iteration */ |
4097 | schedule_delayed_work_on(smp_processor_id(), work, |
4098 | round_jiffies_relative(REAPTIMEOUT_AC)); |
4099 | } |
4100 | |
4101 | void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) |
4102 | { |
4103 | unsigned long active_objs, num_objs, active_slabs; |
4104 | unsigned long total_slabs = 0, free_objs = 0, shared_avail = 0; |
4105 | unsigned long free_slabs = 0; |
4106 | int node; |
4107 | struct kmem_cache_node *n; |
4108 | |
4109 | for_each_kmem_cache_node(cachep, node, n) { |
4110 | check_irq_on(); |
4111 | spin_lock_irq(&n->list_lock); |
4112 | |
4113 | total_slabs += n->total_slabs; |
4114 | free_slabs += n->free_slabs; |
4115 | free_objs += n->free_objects; |
4116 | |
4117 | if (n->shared) |
4118 | shared_avail += n->shared->avail; |
4119 | |
4120 | spin_unlock_irq(&n->list_lock); |
4121 | } |
4122 | num_objs = total_slabs * cachep->num; |
4123 | active_slabs = total_slabs - free_slabs; |
4124 | active_objs = num_objs - free_objs; |
4125 | |
4126 | sinfo->active_objs = active_objs; |
4127 | sinfo->num_objs = num_objs; |
4128 | sinfo->active_slabs = active_slabs; |
4129 | sinfo->num_slabs = total_slabs; |
4130 | sinfo->shared_avail = shared_avail; |
4131 | sinfo->limit = cachep->limit; |
4132 | sinfo->batchcount = cachep->batchcount; |
4133 | sinfo->shared = cachep->shared; |
4134 | sinfo->objects_per_slab = cachep->num; |
4135 | sinfo->cache_order = cachep->gfporder; |
4136 | } |
4137 | |
4138 | void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) |
4139 | { |
4140 | #if STATS |
4141 | { /* node stats */ |
4142 | unsigned long high = cachep->high_mark; |
4143 | unsigned long allocs = cachep->num_allocations; |
4144 | unsigned long grown = cachep->grown; |
4145 | unsigned long reaped = cachep->reaped; |
4146 | unsigned long errors = cachep->errors; |
4147 | unsigned long max_freeable = cachep->max_freeable; |
4148 | unsigned long node_allocs = cachep->node_allocs; |
4149 | unsigned long node_frees = cachep->node_frees; |
4150 | unsigned long overflows = cachep->node_overflow; |
4151 | |
4152 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu", |
4153 | allocs, high, grown, |
4154 | reaped, errors, max_freeable, node_allocs, |
4155 | node_frees, overflows); |
4156 | } |
4157 | /* cpu stats */ |
4158 | { |
4159 | unsigned long allochit = atomic_read(&cachep->allochit); |
4160 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); |
4161 | unsigned long freehit = atomic_read(&cachep->freehit); |
4162 | unsigned long freemiss = atomic_read(&cachep->freemiss); |
4163 | |
4164 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", |
4165 | allochit, allocmiss, freehit, freemiss); |
4166 | } |
4167 | #endif |
4168 | } |
4169 | |
4170 | #define MAX_SLABINFO_WRITE 128 |
4171 | /** |
4172 | * slabinfo_write - Tuning for the slab allocator |
4173 | * @file: unused |
4174 | * @buffer: user buffer |
4175 | * @count: data length |
4176 | * @ppos: unused |
4177 | * |
4178 | * Return: %0 on success, negative error code otherwise. |
4179 | */ |
4180 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, |
4181 | size_t count, loff_t *ppos) |
4182 | { |
4183 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; |
4184 | int limit, batchcount, shared, res; |
4185 | struct kmem_cache *cachep; |
4186 | |
4187 | if (count > MAX_SLABINFO_WRITE) |
4188 | return -EINVAL; |
4189 | if (copy_from_user(&kbuf, buffer, count)) |
4190 | return -EFAULT; |
4191 | kbuf[MAX_SLABINFO_WRITE] = '\0'; |
4192 | |
4193 | tmp = strchr(kbuf, ' '); |
4194 | if (!tmp) |
4195 | return -EINVAL; |
4196 | *tmp = '\0'; |
4197 | tmp++; |
4198 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) |
4199 | return -EINVAL; |
4200 | |
4201 | /* Find the cache in the chain of caches. */ |
4202 | mutex_lock(&slab_mutex); |
4203 | res = -EINVAL; |
4204 | list_for_each_entry(cachep, &slab_caches, list) { |
4205 | if (!strcmp(cachep->name, kbuf)) { |
4206 | if (limit < 1 || batchcount < 1 || |
4207 | batchcount > limit || shared < 0) { |
4208 | res = 0; |
4209 | } else { |
4210 | res = do_tune_cpucache(cachep, limit, |
4211 | batchcount, shared, |
4212 | GFP_KERNEL); |
4213 | } |
4214 | break; |
4215 | } |
4216 | } |
4217 | mutex_unlock(&slab_mutex); |
4218 | if (res >= 0) |
4219 | res = count; |
4220 | return res; |
4221 | } |
4222 | |
4223 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4224 | |
4225 | static inline int add_caller(unsigned long *n, unsigned long v) |
4226 | { |
4227 | unsigned long *p; |
4228 | int l; |
4229 | if (!v) |
4230 | return 1; |
4231 | l = n[1]; |
4232 | p = n + 2; |
4233 | while (l) { |
4234 | int i = l/2; |
4235 | unsigned long *q = p + 2 * i; |
4236 | if (*q == v) { |
4237 | q[1]++; |
4238 | return 1; |
4239 | } |
4240 | if (*q > v) { |
4241 | l = i; |
4242 | } else { |
4243 | p = q + 2; |
4244 | l -= i + 1; |
4245 | } |
4246 | } |
4247 | if (++n[1] == n[0]) |
4248 | return 0; |
4249 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); |
4250 | p[0] = v; |
4251 | p[1] = 1; |
4252 | return 1; |
4253 | } |
4254 | |
4255 | static void handle_slab(unsigned long *n, struct kmem_cache *c, |
4256 | struct page *page) |
4257 | { |
4258 | void *p; |
4259 | int i, j; |
4260 | unsigned long v; |
4261 | |
4262 | if (n[0] == n[1]) |
4263 | return; |
4264 | for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) { |
4265 | bool active = true; |
4266 | |
4267 | for (j = page->active; j < c->num; j++) { |
4268 | if (get_free_obj(page, j) == i) { |
4269 | active = false; |
4270 | break; |
4271 | } |
4272 | } |
4273 | |
4274 | if (!active) |
4275 | continue; |
4276 | |
4277 | /* |
4278 | * probe_kernel_read() is used for DEBUG_PAGEALLOC. page table |
4279 | * mapping is established when actual object allocation and |
4280 | * we could mistakenly access the unmapped object in the cpu |
4281 | * cache. |
4282 | */ |
4283 | if (probe_kernel_read(&v, dbg_userword(c, p), sizeof(v))) |
4284 | continue; |
4285 | |
4286 | if (!add_caller(n, v)) |
4287 | return; |
4288 | } |
4289 | } |
4290 | |
4291 | static void show_symbol(struct seq_file *m, unsigned long address) |
4292 | { |
4293 | #ifdef CONFIG_KALLSYMS |
4294 | unsigned long offset, size; |
4295 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; |
4296 | |
4297 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { |
4298 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); |
4299 | if (modname[0]) |
4300 | seq_printf(m, " [%s]", modname); |
4301 | return; |
4302 | } |
4303 | #endif |
4304 | seq_printf(m, "%px", (void *)address); |
4305 | } |
4306 | |
4307 | static int leaks_show(struct seq_file *m, void *p) |
4308 | { |
4309 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); |
4310 | struct page *page; |
4311 | struct kmem_cache_node *n; |
4312 | const char *name; |
4313 | unsigned long *x = m->private; |
4314 | int node; |
4315 | int i; |
4316 | |
4317 | if (!(cachep->flags & SLAB_STORE_USER)) |
4318 | return 0; |
4319 | if (!(cachep->flags & SLAB_RED_ZONE)) |
4320 | return 0; |
4321 | |
4322 | /* |
4323 | * Set store_user_clean and start to grab stored user information |
4324 | * for all objects on this cache. If some alloc/free requests comes |
4325 | * during the processing, information would be wrong so restart |
4326 | * whole processing. |
4327 | */ |
4328 | do { |
4329 | set_store_user_clean(cachep); |
4330 | drain_cpu_caches(cachep); |
4331 | |
4332 | x[1] = 0; |
4333 | |
4334 | for_each_kmem_cache_node(cachep, node, n) { |
4335 | |
4336 | check_irq_on(); |
4337 | spin_lock_irq(&n->list_lock); |
4338 | |
4339 | list_for_each_entry(page, &n->slabs_full, lru) |
4340 | handle_slab(x, cachep, page); |
4341 | list_for_each_entry(page, &n->slabs_partial, lru) |
4342 | handle_slab(x, cachep, page); |
4343 | spin_unlock_irq(&n->list_lock); |
4344 | } |
4345 | } while (!is_store_user_clean(cachep)); |
4346 | |
4347 | name = cachep->name; |
4348 | if (x[0] == x[1]) { |
4349 | /* Increase the buffer size */ |
4350 | mutex_unlock(&slab_mutex); |
4351 | m->private = kcalloc(x[0] * 4, sizeof(unsigned long), |
4352 | GFP_KERNEL); |
4353 | if (!m->private) { |
4354 | /* Too bad, we are really out */ |
4355 | m->private = x; |
4356 | mutex_lock(&slab_mutex); |
4357 | return -ENOMEM; |
4358 | } |
4359 | *(unsigned long *)m->private = x[0] * 2; |
4360 | kfree(x); |
4361 | mutex_lock(&slab_mutex); |
4362 | /* Now make sure this entry will be retried */ |
4363 | m->count = m->size; |
4364 | return 0; |
4365 | } |
4366 | for (i = 0; i < x[1]; i++) { |
4367 | seq_printf(m, "%s: %lu ", name, x[2*i+3]); |
4368 | show_symbol(m, x[2*i+2]); |
4369 | seq_putc(m, '\n'); |
4370 | } |
4371 | |
4372 | return 0; |
4373 | } |
4374 | |
4375 | static const struct seq_operations slabstats_op = { |
4376 | .start = slab_start, |
4377 | .next = slab_next, |
4378 | .stop = slab_stop, |
4379 | .show = leaks_show, |
4380 | }; |
4381 | |
4382 | static int slabstats_open(struct inode *inode, struct file *file) |
4383 | { |
4384 | unsigned long *n; |
4385 | |
4386 | n = __seq_open_private(file, &slabstats_op, PAGE_SIZE); |
4387 | if (!n) |
4388 | return -ENOMEM; |
4389 | |
4390 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); |
4391 | |
4392 | return 0; |
4393 | } |
4394 | |
4395 | static const struct file_operations proc_slabstats_operations = { |
4396 | .open = slabstats_open, |
4397 | .read = seq_read, |
4398 | .llseek = seq_lseek, |
4399 | .release = seq_release_private, |
4400 | }; |
4401 | #endif |
4402 | |
4403 | static int __init slab_proc_init(void) |
4404 | { |
4405 | #ifdef CONFIG_DEBUG_SLAB_LEAK |
4406 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); |
4407 | #endif |
4408 | return 0; |
4409 | } |
4410 | module_init(slab_proc_init); |
4411 | |
4412 | #ifdef CONFIG_HARDENED_USERCOPY |
4413 | /* |
4414 | * Rejects incorrectly sized objects and objects that are to be copied |
4415 | * to/from userspace but do not fall entirely within the containing slab |
4416 | * cache's usercopy region. |
4417 | * |
4418 | * Returns NULL if check passes, otherwise const char * to name of cache |
4419 | * to indicate an error. |
4420 | */ |
4421 | void __check_heap_object(const void *ptr, unsigned long n, struct page *page, |
4422 | bool to_user) |
4423 | { |
4424 | struct kmem_cache *cachep; |
4425 | unsigned int objnr; |
4426 | unsigned long offset; |
4427 | |
4428 | ptr = kasan_reset_tag(ptr); |
4429 | |
4430 | /* Find and validate object. */ |
4431 | cachep = page->slab_cache; |
4432 | objnr = obj_to_index(cachep, page, (void *)ptr); |
4433 | BUG_ON(objnr >= cachep->num); |
4434 | |
4435 | /* Find offset within object. */ |
4436 | offset = ptr - index_to_obj(cachep, page, objnr) - obj_offset(cachep); |
4437 | |
4438 | /* Allow address range falling entirely within usercopy region. */ |
4439 | if (offset >= cachep->useroffset && |
4440 | offset - cachep->useroffset <= cachep->usersize && |
4441 | n <= cachep->useroffset - offset + cachep->usersize) |
4442 | return; |
4443 | |
4444 | /* |
4445 | * If the copy is still within the allocated object, produce |
4446 | * a warning instead of rejecting the copy. This is intended |
4447 | * to be a temporary method to find any missing usercopy |
4448 | * whitelists. |
4449 | */ |
4450 | if (usercopy_fallback && |
4451 | offset <= cachep->object_size && |
4452 | n <= cachep->object_size - offset) { |
4453 | usercopy_warn("SLAB object", cachep->name, to_user, offset, n); |
4454 | return; |
4455 | } |
4456 | |
4457 | usercopy_abort("SLAB object", cachep->name, to_user, offset, n); |
4458 | } |
4459 | #endif /* CONFIG_HARDENED_USERCOPY */ |
4460 | |
4461 | /** |
4462 | * ksize - get the actual amount of memory allocated for a given object |
4463 | * @objp: Pointer to the object |
4464 | * |
4465 | * kmalloc may internally round up allocations and return more memory |
4466 | * than requested. ksize() can be used to determine the actual amount of |
4467 | * memory allocated. The caller may use this additional memory, even though |
4468 | * a smaller amount of memory was initially specified with the kmalloc call. |
4469 | * The caller must guarantee that objp points to a valid object previously |
4470 | * allocated with either kmalloc() or kmem_cache_alloc(). The object |
4471 | * must not be freed during the duration of the call. |
4472 | * |
4473 | * Return: size of the actual memory used by @objp in bytes |
4474 | */ |
4475 | size_t ksize(const void *objp) |
4476 | { |
4477 | size_t size; |
4478 | |
4479 | BUG_ON(!objp); |
4480 | if (unlikely(objp == ZERO_SIZE_PTR)) |
4481 | return 0; |
4482 | |
4483 | size = virt_to_cache(objp)->object_size; |
4484 | /* We assume that ksize callers could use the whole allocated area, |
4485 | * so we need to unpoison this area. |
4486 | */ |
4487 | kasan_unpoison_shadow(objp, size); |
4488 | |
4489 | return size; |
4490 | } |
4491 | EXPORT_SYMBOL(ksize); |
4492 |
Warning: That file was not part of the compilation database. It may have many parsing errors.