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1 | /* | |
2 | * linux/mm/slab.c | |
3 | * Written by Mark Hemment, 1996/97. | |
4 | * (markhe@nextd.demon.co.uk) | |
5 | * | |
6 | * kmem_cache_destroy() + some cleanup - 1999 Andrea Arcangeli | |
7 | * | |
8 | * Major cleanup, different bufctl logic, per-cpu arrays | |
9 | * (c) 2000 Manfred Spraul | |
10 | * | |
11 | * Cleanup, make the head arrays unconditional, preparation for NUMA | |
12 | * (c) 2002 Manfred Spraul | |
13 | * | |
14 | * An implementation of the Slab Allocator as described in outline in; | |
15 | * UNIX Internals: The New Frontiers by Uresh Vahalia | |
16 | * Pub: Prentice Hall ISBN 0-13-101908-2 | |
17 | * or with a little more detail in; | |
18 | * The Slab Allocator: An Object-Caching Kernel Memory Allocator | |
19 | * Jeff Bonwick (Sun Microsystems). | |
20 | * Presented at: USENIX Summer 1994 Technical Conference | |
21 | * | |
22 | * The memory is organized in caches, one cache for each object type. | |
23 | * (e.g. inode_cache, dentry_cache, buffer_head, vm_area_struct) | |
24 | * Each cache consists out of many slabs (they are small (usually one | |
25 | * page long) and always contiguous), and each slab contains multiple | |
26 | * initialized objects. | |
27 | * | |
28 | * This means, that your constructor is used only for newly allocated | |
29 | * slabs and you must pass objects with the same initializations to | |
30 | * kmem_cache_free. | |
31 | * | |
32 | * Each cache can only support one memory type (GFP_DMA, GFP_HIGHMEM, | |
33 | * normal). If you need a special memory type, then must create a new | |
34 | * cache for that memory type. | |
35 | * | |
36 | * In order to reduce fragmentation, the slabs are sorted in 3 groups: | |
37 | * full slabs with 0 free objects | |
38 | * partial slabs | |
39 | * empty slabs with no allocated objects | |
40 | * | |
41 | * If partial slabs exist, then new allocations come from these slabs, | |
42 | * otherwise from empty slabs or new slabs are allocated. | |
43 | * | |
44 | * kmem_cache_destroy() CAN CRASH if you try to allocate from the cache | |
45 | * during kmem_cache_destroy(). The caller must prevent concurrent allocs. | |
46 | * | |
47 | * Each cache has a short per-cpu head array, most allocs | |
48 | * and frees go into that array, and if that array overflows, then 1/2 | |
49 | * of the entries in the array are given back into the global cache. | |
50 | * The head array is strictly LIFO and should improve the cache hit rates. | |
51 | * On SMP, it additionally reduces the spinlock operations. | |
52 | * | |
53 | * The c_cpuarray may not be read with enabled local interrupts - | |
54 | * it's changed with a smp_call_function(). | |
55 | * | |
56 | * SMP synchronization: | |
57 | * constructors and destructors are called without any locking. | |
58 | * Several members in struct kmem_cache and struct slab never change, they | |
59 | * are accessed without any locking. | |
60 | * The per-cpu arrays are never accessed from the wrong cpu, no locking, | |
61 | * and local interrupts are disabled so slab code is preempt-safe. | |
62 | * The non-constant members are protected with a per-cache irq spinlock. | |
63 | * | |
64 | * Many thanks to Mark Hemment, who wrote another per-cpu slab patch | |
65 | * in 2000 - many ideas in the current implementation are derived from | |
66 | * his patch. | |
67 | * | |
68 | * Further notes from the original documentation: | |
69 | * | |
70 | * 11 April '97. Started multi-threading - markhe | |
71 | * The global cache-chain is protected by the mutex 'slab_mutex'. | |
72 | * The sem is only needed when accessing/extending the cache-chain, which | |
73 | * can never happen inside an interrupt (kmem_cache_create(), | |
74 | * kmem_cache_shrink() and kmem_cache_reap()). | |
75 | * | |
76 | * At present, each engine can be growing a cache. This should be blocked. | |
77 | * | |
78 | * 15 March 2005. NUMA slab allocator. | |
79 | * Shai Fultheim <shai@scalex86.org>. | |
80 | * Shobhit Dayal <shobhit@calsoftinc.com> | |
81 | * Alok N Kataria <alokk@calsoftinc.com> | |
82 | * Christoph Lameter <christoph@lameter.com> | |
83 | * | |
84 | * Modified the slab allocator to be node aware on NUMA systems. | |
85 | * Each node has its own list of partial, free and full slabs. | |
86 | * All object allocations for a node occur from node specific slab lists. | |
87 | */ | |
88 | ||
89 | #include <linux/slab.h> | |
90 | #include <linux/mm.h> | |
91 | #include <linux/poison.h> | |
92 | #include <linux/swap.h> | |
93 | #include <linux/cache.h> | |
94 | #include <linux/interrupt.h> | |
95 | #include <linux/init.h> | |
96 | #include <linux/compiler.h> | |
97 | #include <linux/cpuset.h> | |
98 | #include <linux/proc_fs.h> | |
99 | #include <linux/seq_file.h> | |
100 | #include <linux/notifier.h> | |
101 | #include <linux/kallsyms.h> | |
102 | #include <linux/cpu.h> | |
103 | #include <linux/sysctl.h> | |
104 | #include <linux/module.h> | |
105 | #include <linux/rcupdate.h> | |
106 | #include <linux/string.h> | |
107 | #include <linux/uaccess.h> | |
108 | #include <linux/nodemask.h> | |
109 | #include <linux/kmemleak.h> | |
110 | #include <linux/mempolicy.h> | |
111 | #include <linux/mutex.h> | |
112 | #include <linux/fault-inject.h> | |
113 | #include <linux/rtmutex.h> | |
114 | #include <linux/reciprocal_div.h> | |
115 | #include <linux/debugobjects.h> | |
116 | #include <linux/kmemcheck.h> | |
117 | #include <linux/memory.h> | |
118 | #include <linux/prefetch.h> | |
119 | ||
120 | #include <net/sock.h> | |
121 | ||
122 | #include <asm/cacheflush.h> | |
123 | #include <asm/tlbflush.h> | |
124 | #include <asm/page.h> | |
125 | ||
126 | #include <trace/events/kmem.h> | |
127 | ||
128 | #include "internal.h" | |
129 | ||
130 | #include "slab.h" | |
131 | ||
132 | /* | |
133 | * DEBUG - 1 for kmem_cache_create() to honour; SLAB_RED_ZONE & SLAB_POISON. | |
134 | * 0 for faster, smaller code (especially in the critical paths). | |
135 | * | |
136 | * STATS - 1 to collect stats for /proc/slabinfo. | |
137 | * 0 for faster, smaller code (especially in the critical paths). | |
138 | * | |
139 | * FORCED_DEBUG - 1 enables SLAB_RED_ZONE and SLAB_POISON (if possible) | |
140 | */ | |
141 | ||
142 | #ifdef CONFIG_DEBUG_SLAB | |
143 | #define DEBUG 1 | |
144 | #define STATS 1 | |
145 | #define FORCED_DEBUG 1 | |
146 | #else | |
147 | #define DEBUG 0 | |
148 | #define STATS 0 | |
149 | #define FORCED_DEBUG 0 | |
150 | #endif | |
151 | ||
152 | /* Shouldn't this be in a header file somewhere? */ | |
153 | #define BYTES_PER_WORD sizeof(void *) | |
154 | #define REDZONE_ALIGN max(BYTES_PER_WORD, __alignof__(unsigned long long)) | |
155 | ||
156 | #ifndef ARCH_KMALLOC_FLAGS | |
157 | #define ARCH_KMALLOC_FLAGS SLAB_HWCACHE_ALIGN | |
158 | #endif | |
159 | ||
160 | #define FREELIST_BYTE_INDEX (((PAGE_SIZE >> BITS_PER_BYTE) \ | |
161 | <= SLAB_OBJ_MIN_SIZE) ? 1 : 0) | |
162 | ||
163 | #if FREELIST_BYTE_INDEX | |
164 | typedef unsigned char freelist_idx_t; | |
165 | #else | |
166 | typedef unsigned short freelist_idx_t; | |
167 | #endif | |
168 | ||
169 | #define SLAB_OBJ_MAX_NUM ((1 << sizeof(freelist_idx_t) * BITS_PER_BYTE) - 1) | |
170 | ||
171 | /* | |
172 | * struct array_cache | |
173 | * | |
174 | * Purpose: | |
175 | * - LIFO ordering, to hand out cache-warm objects from _alloc | |
176 | * - reduce the number of linked list operations | |
177 | * - reduce spinlock operations | |
178 | * | |
179 | * The limit is stored in the per-cpu structure to reduce the data cache | |
180 | * footprint. | |
181 | * | |
182 | */ | |
183 | struct array_cache { | |
184 | unsigned int avail; | |
185 | unsigned int limit; | |
186 | unsigned int batchcount; | |
187 | unsigned int touched; | |
188 | void *entry[]; /* | |
189 | * Must have this definition in here for the proper | |
190 | * alignment of array_cache. Also simplifies accessing | |
191 | * the entries. | |
192 | */ | |
193 | }; | |
194 | ||
195 | struct alien_cache { | |
196 | spinlock_t lock; | |
197 | struct array_cache ac; | |
198 | }; | |
199 | ||
200 | /* | |
201 | * Need this for bootstrapping a per node allocator. | |
202 | */ | |
203 | #define NUM_INIT_LISTS (2 * MAX_NUMNODES) | |
204 | static struct kmem_cache_node __initdata init_kmem_cache_node[NUM_INIT_LISTS]; | |
205 | #define CACHE_CACHE 0 | |
206 | #define SIZE_NODE (MAX_NUMNODES) | |
207 | ||
208 | static int drain_freelist(struct kmem_cache *cache, | |
209 | struct kmem_cache_node *n, int tofree); | |
210 | static void free_block(struct kmem_cache *cachep, void **objpp, int len, | |
211 | int node, struct list_head *list); | |
212 | static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list); | |
213 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp); | |
214 | static void cache_reap(struct work_struct *unused); | |
215 | ||
216 | static inline void fixup_objfreelist_debug(struct kmem_cache *cachep, | |
217 | void **list); | |
218 | static inline void fixup_slab_list(struct kmem_cache *cachep, | |
219 | struct kmem_cache_node *n, struct page *page, | |
220 | void **list); | |
221 | static int slab_early_init = 1; | |
222 | ||
223 | #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) | |
224 | ||
225 | static void kmem_cache_node_init(struct kmem_cache_node *parent) | |
226 | { | |
227 | INIT_LIST_HEAD(&parent->slabs_full); | |
228 | INIT_LIST_HEAD(&parent->slabs_partial); | |
229 | INIT_LIST_HEAD(&parent->slabs_free); | |
230 | parent->total_slabs = 0; | |
231 | parent->free_slabs = 0; | |
232 | parent->shared = NULL; | |
233 | parent->alien = NULL; | |
234 | parent->colour_next = 0; | |
235 | spin_lock_init(&parent->list_lock); | |
236 | parent->free_objects = 0; | |
237 | parent->free_touched = 0; | |
238 | } | |
239 | ||
240 | #define MAKE_LIST(cachep, listp, slab, nodeid) \ | |
241 | do { \ | |
242 | INIT_LIST_HEAD(listp); \ | |
243 | list_splice(&get_node(cachep, nodeid)->slab, listp); \ | |
244 | } while (0) | |
245 | ||
246 | #define MAKE_ALL_LISTS(cachep, ptr, nodeid) \ | |
247 | do { \ | |
248 | MAKE_LIST((cachep), (&(ptr)->slabs_full), slabs_full, nodeid); \ | |
249 | MAKE_LIST((cachep), (&(ptr)->slabs_partial), slabs_partial, nodeid); \ | |
250 | MAKE_LIST((cachep), (&(ptr)->slabs_free), slabs_free, nodeid); \ | |
251 | } while (0) | |
252 | ||
253 | #define CFLGS_OBJFREELIST_SLAB (0x40000000UL) | |
254 | #define CFLGS_OFF_SLAB (0x80000000UL) | |
255 | #define OBJFREELIST_SLAB(x) ((x)->flags & CFLGS_OBJFREELIST_SLAB) | |
256 | #define OFF_SLAB(x) ((x)->flags & CFLGS_OFF_SLAB) | |
257 | ||
258 | #define BATCHREFILL_LIMIT 16 | |
259 | /* | |
260 | * Optimization question: fewer reaps means less probability for unnessary | |
261 | * cpucache drain/refill cycles. | |
262 | * | |
263 | * OTOH the cpuarrays can contain lots of objects, | |
264 | * which could lock up otherwise freeable slabs. | |
265 | */ | |
266 | #define REAPTIMEOUT_AC (2*HZ) | |
267 | #define REAPTIMEOUT_NODE (4*HZ) | |
268 | ||
269 | #if STATS | |
270 | #define STATS_INC_ACTIVE(x) ((x)->num_active++) | |
271 | #define STATS_DEC_ACTIVE(x) ((x)->num_active--) | |
272 | #define STATS_INC_ALLOCED(x) ((x)->num_allocations++) | |
273 | #define STATS_INC_GROWN(x) ((x)->grown++) | |
274 | #define STATS_ADD_REAPED(x,y) ((x)->reaped += (y)) | |
275 | #define STATS_SET_HIGH(x) \ | |
276 | do { \ | |
277 | if ((x)->num_active > (x)->high_mark) \ | |
278 | (x)->high_mark = (x)->num_active; \ | |
279 | } while (0) | |
280 | #define STATS_INC_ERR(x) ((x)->errors++) | |
281 | #define STATS_INC_NODEALLOCS(x) ((x)->node_allocs++) | |
282 | #define STATS_INC_NODEFREES(x) ((x)->node_frees++) | |
283 | #define STATS_INC_ACOVERFLOW(x) ((x)->node_overflow++) | |
284 | #define STATS_SET_FREEABLE(x, i) \ | |
285 | do { \ | |
286 | if ((x)->max_freeable < i) \ | |
287 | (x)->max_freeable = i; \ | |
288 | } while (0) | |
289 | #define STATS_INC_ALLOCHIT(x) atomic_inc(&(x)->allochit) | |
290 | #define STATS_INC_ALLOCMISS(x) atomic_inc(&(x)->allocmiss) | |
291 | #define STATS_INC_FREEHIT(x) atomic_inc(&(x)->freehit) | |
292 | #define STATS_INC_FREEMISS(x) atomic_inc(&(x)->freemiss) | |
293 | #else | |
294 | #define STATS_INC_ACTIVE(x) do { } while (0) | |
295 | #define STATS_DEC_ACTIVE(x) do { } while (0) | |
296 | #define STATS_INC_ALLOCED(x) do { } while (0) | |
297 | #define STATS_INC_GROWN(x) do { } while (0) | |
298 | #define STATS_ADD_REAPED(x,y) do { (void)(y); } while (0) | |
299 | #define STATS_SET_HIGH(x) do { } while (0) | |
300 | #define STATS_INC_ERR(x) do { } while (0) | |
301 | #define STATS_INC_NODEALLOCS(x) do { } while (0) | |
302 | #define STATS_INC_NODEFREES(x) do { } while (0) | |
303 | #define STATS_INC_ACOVERFLOW(x) do { } while (0) | |
304 | #define STATS_SET_FREEABLE(x, i) do { } while (0) | |
305 | #define STATS_INC_ALLOCHIT(x) do { } while (0) | |
306 | #define STATS_INC_ALLOCMISS(x) do { } while (0) | |
307 | #define STATS_INC_FREEHIT(x) do { } while (0) | |
308 | #define STATS_INC_FREEMISS(x) do { } while (0) | |
309 | #endif | |
310 | ||
311 | #if DEBUG | |
312 | ||
313 | /* | |
314 | * memory layout of objects: | |
315 | * 0 : objp | |
316 | * 0 .. cachep->obj_offset - BYTES_PER_WORD - 1: padding. This ensures that | |
317 | * the end of an object is aligned with the end of the real | |
318 | * allocation. Catches writes behind the end of the allocation. | |
319 | * cachep->obj_offset - BYTES_PER_WORD .. cachep->obj_offset - 1: | |
320 | * redzone word. | |
321 | * cachep->obj_offset: The real object. | |
322 | * cachep->size - 2* BYTES_PER_WORD: redzone word [BYTES_PER_WORD long] | |
323 | * cachep->size - 1* BYTES_PER_WORD: last caller address | |
324 | * [BYTES_PER_WORD long] | |
325 | */ | |
326 | static int obj_offset(struct kmem_cache *cachep) | |
327 | { | |
328 | return cachep->obj_offset; | |
329 | } | |
330 | ||
331 | static unsigned long long *dbg_redzone1(struct kmem_cache *cachep, void *objp) | |
332 | { | |
333 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
334 | return (unsigned long long*) (objp + obj_offset(cachep) - | |
335 | sizeof(unsigned long long)); | |
336 | } | |
337 | ||
338 | static unsigned long long *dbg_redzone2(struct kmem_cache *cachep, void *objp) | |
339 | { | |
340 | BUG_ON(!(cachep->flags & SLAB_RED_ZONE)); | |
341 | if (cachep->flags & SLAB_STORE_USER) | |
342 | return (unsigned long long *)(objp + cachep->size - | |
343 | sizeof(unsigned long long) - | |
344 | REDZONE_ALIGN); | |
345 | return (unsigned long long *) (objp + cachep->size - | |
346 | sizeof(unsigned long long)); | |
347 | } | |
348 | ||
349 | static void **dbg_userword(struct kmem_cache *cachep, void *objp) | |
350 | { | |
351 | BUG_ON(!(cachep->flags & SLAB_STORE_USER)); | |
352 | return (void **)(objp + cachep->size - BYTES_PER_WORD); | |
353 | } | |
354 | ||
355 | #else | |
356 | ||
357 | #define obj_offset(x) 0 | |
358 | #define dbg_redzone1(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
359 | #define dbg_redzone2(cachep, objp) ({BUG(); (unsigned long long *)NULL;}) | |
360 | #define dbg_userword(cachep, objp) ({BUG(); (void **)NULL;}) | |
361 | ||
362 | #endif | |
363 | ||
364 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
365 | ||
366 | static inline bool is_store_user_clean(struct kmem_cache *cachep) | |
367 | { | |
368 | return atomic_read(&cachep->store_user_clean) == 1; | |
369 | } | |
370 | ||
371 | static inline void set_store_user_clean(struct kmem_cache *cachep) | |
372 | { | |
373 | atomic_set(&cachep->store_user_clean, 1); | |
374 | } | |
375 | ||
376 | static inline void set_store_user_dirty(struct kmem_cache *cachep) | |
377 | { | |
378 | if (is_store_user_clean(cachep)) | |
379 | atomic_set(&cachep->store_user_clean, 0); | |
380 | } | |
381 | ||
382 | #else | |
383 | static inline void set_store_user_dirty(struct kmem_cache *cachep) {} | |
384 | ||
385 | #endif | |
386 | ||
387 | /* | |
388 | * Do not go above this order unless 0 objects fit into the slab or | |
389 | * overridden on the command line. | |
390 | */ | |
391 | #define SLAB_MAX_ORDER_HI 1 | |
392 | #define SLAB_MAX_ORDER_LO 0 | |
393 | static int slab_max_order = SLAB_MAX_ORDER_LO; | |
394 | static bool slab_max_order_set __initdata; | |
395 | ||
396 | static inline struct kmem_cache *virt_to_cache(const void *obj) | |
397 | { | |
398 | struct page *page = virt_to_head_page(obj); | |
399 | return page->slab_cache; | |
400 | } | |
401 | ||
402 | static inline void *index_to_obj(struct kmem_cache *cache, struct page *page, | |
403 | unsigned int idx) | |
404 | { | |
405 | return page->s_mem + cache->size * idx; | |
406 | } | |
407 | ||
408 | /* | |
409 | * We want to avoid an expensive divide : (offset / cache->size) | |
410 | * Using the fact that size is a constant for a particular cache, | |
411 | * we can replace (offset / cache->size) by | |
412 | * reciprocal_divide(offset, cache->reciprocal_buffer_size) | |
413 | */ | |
414 | static inline unsigned int obj_to_index(const struct kmem_cache *cache, | |
415 | const struct page *page, void *obj) | |
416 | { | |
417 | u32 offset = (obj - page->s_mem); | |
418 | return reciprocal_divide(offset, cache->reciprocal_buffer_size); | |
419 | } | |
420 | ||
421 | #define BOOT_CPUCACHE_ENTRIES 1 | |
422 | /* internal cache of cache description objs */ | |
423 | static struct kmem_cache kmem_cache_boot = { | |
424 | .batchcount = 1, | |
425 | .limit = BOOT_CPUCACHE_ENTRIES, | |
426 | .shared = 1, | |
427 | .size = sizeof(struct kmem_cache), | |
428 | .name = "kmem_cache", | |
429 | }; | |
430 | ||
431 | static DEFINE_PER_CPU(struct delayed_work, slab_reap_work); | |
432 | ||
433 | static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) | |
434 | { | |
435 | return this_cpu_ptr(cachep->cpu_cache); | |
436 | } | |
437 | ||
438 | /* | |
439 | * Calculate the number of objects and left-over bytes for a given buffer size. | |
440 | */ | |
441 | static unsigned int cache_estimate(unsigned long gfporder, size_t buffer_size, | |
442 | unsigned long flags, size_t *left_over) | |
443 | { | |
444 | unsigned int num; | |
445 | size_t slab_size = PAGE_SIZE << gfporder; | |
446 | ||
447 | /* | |
448 | * The slab management structure can be either off the slab or | |
449 | * on it. For the latter case, the memory allocated for a | |
450 | * slab is used for: | |
451 | * | |
452 | * - @buffer_size bytes for each object | |
453 | * - One freelist_idx_t for each object | |
454 | * | |
455 | * We don't need to consider alignment of freelist because | |
456 | * freelist will be at the end of slab page. The objects will be | |
457 | * at the correct alignment. | |
458 | * | |
459 | * If the slab management structure is off the slab, then the | |
460 | * alignment will already be calculated into the size. Because | |
461 | * the slabs are all pages aligned, the objects will be at the | |
462 | * correct alignment when allocated. | |
463 | */ | |
464 | if (flags & (CFLGS_OBJFREELIST_SLAB | CFLGS_OFF_SLAB)) { | |
465 | num = slab_size / buffer_size; | |
466 | *left_over = slab_size % buffer_size; | |
467 | } else { | |
468 | num = slab_size / (buffer_size + sizeof(freelist_idx_t)); | |
469 | *left_over = slab_size % | |
470 | (buffer_size + sizeof(freelist_idx_t)); | |
471 | } | |
472 | ||
473 | return num; | |
474 | } | |
475 | ||
476 | #if DEBUG | |
477 | #define slab_error(cachep, msg) __slab_error(__func__, cachep, msg) | |
478 | ||
479 | static void __slab_error(const char *function, struct kmem_cache *cachep, | |
480 | char *msg) | |
481 | { | |
482 | pr_err("slab error in %s(): cache `%s': %s\n", | |
483 | function, cachep->name, msg); | |
484 | dump_stack(); | |
485 | add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); | |
486 | } | |
487 | #endif | |
488 | ||
489 | /* | |
490 | * By default on NUMA we use alien caches to stage the freeing of | |
491 | * objects allocated from other nodes. This causes massive memory | |
492 | * inefficiencies when using fake NUMA setup to split memory into a | |
493 | * large number of small nodes, so it can be disabled on the command | |
494 | * line | |
495 | */ | |
496 | ||
497 | static int use_alien_caches __read_mostly = 1; | |
498 | static int __init noaliencache_setup(char *s) | |
499 | { | |
500 | use_alien_caches = 0; | |
501 | return 1; | |
502 | } | |
503 | __setup("noaliencache", noaliencache_setup); | |
504 | ||
505 | static int __init slab_max_order_setup(char *str) | |
506 | { | |
507 | get_option(&str, &slab_max_order); | |
508 | slab_max_order = slab_max_order < 0 ? 0 : | |
509 | min(slab_max_order, MAX_ORDER - 1); | |
510 | slab_max_order_set = true; | |
511 | ||
512 | return 1; | |
513 | } | |
514 | __setup("slab_max_order=", slab_max_order_setup); | |
515 | ||
516 | #ifdef CONFIG_NUMA | |
517 | /* | |
518 | * Special reaping functions for NUMA systems called from cache_reap(). | |
519 | * These take care of doing round robin flushing of alien caches (containing | |
520 | * objects freed on different nodes from which they were allocated) and the | |
521 | * flushing of remote pcps by calling drain_node_pages. | |
522 | */ | |
523 | static DEFINE_PER_CPU(unsigned long, slab_reap_node); | |
524 | ||
525 | static void init_reap_node(int cpu) | |
526 | { | |
527 | per_cpu(slab_reap_node, cpu) = next_node_in(cpu_to_mem(cpu), | |
528 | node_online_map); | |
529 | } | |
530 | ||
531 | static void next_reap_node(void) | |
532 | { | |
533 | int node = __this_cpu_read(slab_reap_node); | |
534 | ||
535 | node = next_node_in(node, node_online_map); | |
536 | __this_cpu_write(slab_reap_node, node); | |
537 | } | |
538 | ||
539 | #else | |
540 | #define init_reap_node(cpu) do { } while (0) | |
541 | #define next_reap_node(void) do { } while (0) | |
542 | #endif | |
543 | ||
544 | /* | |
545 | * Initiate the reap timer running on the target CPU. We run at around 1 to 2Hz | |
546 | * via the workqueue/eventd. | |
547 | * Add the CPU number into the expiration time to minimize the possibility of | |
548 | * the CPUs getting into lockstep and contending for the global cache chain | |
549 | * lock. | |
550 | */ | |
551 | static void start_cpu_timer(int cpu) | |
552 | { | |
553 | struct delayed_work *reap_work = &per_cpu(slab_reap_work, cpu); | |
554 | ||
555 | if (reap_work->work.func == NULL) { | |
556 | init_reap_node(cpu); | |
557 | INIT_DEFERRABLE_WORK(reap_work, cache_reap); | |
558 | schedule_delayed_work_on(cpu, reap_work, | |
559 | __round_jiffies_relative(HZ, cpu)); | |
560 | } | |
561 | } | |
562 | ||
563 | static void init_arraycache(struct array_cache *ac, int limit, int batch) | |
564 | { | |
565 | /* | |
566 | * The array_cache structures contain pointers to free object. | |
567 | * However, when such objects are allocated or transferred to another | |
568 | * cache the pointers are not cleared and they could be counted as | |
569 | * valid references during a kmemleak scan. Therefore, kmemleak must | |
570 | * not scan such objects. | |
571 | */ | |
572 | kmemleak_no_scan(ac); | |
573 | if (ac) { | |
574 | ac->avail = 0; | |
575 | ac->limit = limit; | |
576 | ac->batchcount = batch; | |
577 | ac->touched = 0; | |
578 | } | |
579 | } | |
580 | ||
581 | static struct array_cache *alloc_arraycache(int node, int entries, | |
582 | int batchcount, gfp_t gfp) | |
583 | { | |
584 | size_t memsize = sizeof(void *) * entries + sizeof(struct array_cache); | |
585 | struct array_cache *ac = NULL; | |
586 | ||
587 | ac = kmalloc_node(memsize, gfp, node); | |
588 | init_arraycache(ac, entries, batchcount); | |
589 | return ac; | |
590 | } | |
591 | ||
592 | static noinline void cache_free_pfmemalloc(struct kmem_cache *cachep, | |
593 | struct page *page, void *objp) | |
594 | { | |
595 | struct kmem_cache_node *n; | |
596 | int page_node; | |
597 | LIST_HEAD(list); | |
598 | ||
599 | page_node = page_to_nid(page); | |
600 | n = get_node(cachep, page_node); | |
601 | ||
602 | spin_lock(&n->list_lock); | |
603 | free_block(cachep, &objp, 1, page_node, &list); | |
604 | spin_unlock(&n->list_lock); | |
605 | ||
606 | slabs_destroy(cachep, &list); | |
607 | } | |
608 | ||
609 | /* | |
610 | * Transfer objects in one arraycache to another. | |
611 | * Locking must be handled by the caller. | |
612 | * | |
613 | * Return the number of entries transferred. | |
614 | */ | |
615 | static int transfer_objects(struct array_cache *to, | |
616 | struct array_cache *from, unsigned int max) | |
617 | { | |
618 | /* Figure out how many entries to transfer */ | |
619 | int nr = min3(from->avail, max, to->limit - to->avail); | |
620 | ||
621 | if (!nr) | |
622 | return 0; | |
623 | ||
624 | memcpy(to->entry + to->avail, from->entry + from->avail -nr, | |
625 | sizeof(void *) *nr); | |
626 | ||
627 | from->avail -= nr; | |
628 | to->avail += nr; | |
629 | return nr; | |
630 | } | |
631 | ||
632 | #ifndef CONFIG_NUMA | |
633 | ||
634 | #define drain_alien_cache(cachep, alien) do { } while (0) | |
635 | #define reap_alien(cachep, n) do { } while (0) | |
636 | ||
637 | static inline struct alien_cache **alloc_alien_cache(int node, | |
638 | int limit, gfp_t gfp) | |
639 | { | |
640 | return NULL; | |
641 | } | |
642 | ||
643 | static inline void free_alien_cache(struct alien_cache **ac_ptr) | |
644 | { | |
645 | } | |
646 | ||
647 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
648 | { | |
649 | return 0; | |
650 | } | |
651 | ||
652 | static inline void *alternate_node_alloc(struct kmem_cache *cachep, | |
653 | gfp_t flags) | |
654 | { | |
655 | return NULL; | |
656 | } | |
657 | ||
658 | static inline void *____cache_alloc_node(struct kmem_cache *cachep, | |
659 | gfp_t flags, int nodeid) | |
660 | { | |
661 | return NULL; | |
662 | } | |
663 | ||
664 | static inline gfp_t gfp_exact_node(gfp_t flags) | |
665 | { | |
666 | return flags & ~__GFP_NOFAIL; | |
667 | } | |
668 | ||
669 | #else /* CONFIG_NUMA */ | |
670 | ||
671 | static void *____cache_alloc_node(struct kmem_cache *, gfp_t, int); | |
672 | static void *alternate_node_alloc(struct kmem_cache *, gfp_t); | |
673 | ||
674 | static struct alien_cache *__alloc_alien_cache(int node, int entries, | |
675 | int batch, gfp_t gfp) | |
676 | { | |
677 | size_t memsize = sizeof(void *) * entries + sizeof(struct alien_cache); | |
678 | struct alien_cache *alc = NULL; | |
679 | ||
680 | alc = kmalloc_node(memsize, gfp, node); | |
681 | init_arraycache(&alc->ac, entries, batch); | |
682 | spin_lock_init(&alc->lock); | |
683 | return alc; | |
684 | } | |
685 | ||
686 | static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp) | |
687 | { | |
688 | struct alien_cache **alc_ptr; | |
689 | size_t memsize = sizeof(void *) * nr_node_ids; | |
690 | int i; | |
691 | ||
692 | if (limit > 1) | |
693 | limit = 12; | |
694 | alc_ptr = kzalloc_node(memsize, gfp, node); | |
695 | if (!alc_ptr) | |
696 | return NULL; | |
697 | ||
698 | for_each_node(i) { | |
699 | if (i == node || !node_online(i)) | |
700 | continue; | |
701 | alc_ptr[i] = __alloc_alien_cache(node, limit, 0xbaadf00d, gfp); | |
702 | if (!alc_ptr[i]) { | |
703 | for (i--; i >= 0; i--) | |
704 | kfree(alc_ptr[i]); | |
705 | kfree(alc_ptr); | |
706 | return NULL; | |
707 | } | |
708 | } | |
709 | return alc_ptr; | |
710 | } | |
711 | ||
712 | static void free_alien_cache(struct alien_cache **alc_ptr) | |
713 | { | |
714 | int i; | |
715 | ||
716 | if (!alc_ptr) | |
717 | return; | |
718 | for_each_node(i) | |
719 | kfree(alc_ptr[i]); | |
720 | kfree(alc_ptr); | |
721 | } | |
722 | ||
723 | static void __drain_alien_cache(struct kmem_cache *cachep, | |
724 | struct array_cache *ac, int node, | |
725 | struct list_head *list) | |
726 | { | |
727 | struct kmem_cache_node *n = get_node(cachep, node); | |
728 | ||
729 | if (ac->avail) { | |
730 | spin_lock(&n->list_lock); | |
731 | /* | |
732 | * Stuff objects into the remote nodes shared array first. | |
733 | * That way we could avoid the overhead of putting the objects | |
734 | * into the free lists and getting them back later. | |
735 | */ | |
736 | if (n->shared) | |
737 | transfer_objects(n->shared, ac, ac->limit); | |
738 | ||
739 | free_block(cachep, ac->entry, ac->avail, node, list); | |
740 | ac->avail = 0; | |
741 | spin_unlock(&n->list_lock); | |
742 | } | |
743 | } | |
744 | ||
745 | /* | |
746 | * Called from cache_reap() to regularly drain alien caches round robin. | |
747 | */ | |
748 | static void reap_alien(struct kmem_cache *cachep, struct kmem_cache_node *n) | |
749 | { | |
750 | int node = __this_cpu_read(slab_reap_node); | |
751 | ||
752 | if (n->alien) { | |
753 | struct alien_cache *alc = n->alien[node]; | |
754 | struct array_cache *ac; | |
755 | ||
756 | if (alc) { | |
757 | ac = &alc->ac; | |
758 | if (ac->avail && spin_trylock_irq(&alc->lock)) { | |
759 | LIST_HEAD(list); | |
760 | ||
761 | __drain_alien_cache(cachep, ac, node, &list); | |
762 | spin_unlock_irq(&alc->lock); | |
763 | slabs_destroy(cachep, &list); | |
764 | } | |
765 | } | |
766 | } | |
767 | } | |
768 | ||
769 | static void drain_alien_cache(struct kmem_cache *cachep, | |
770 | struct alien_cache **alien) | |
771 | { | |
772 | int i = 0; | |
773 | struct alien_cache *alc; | |
774 | struct array_cache *ac; | |
775 | unsigned long flags; | |
776 | ||
777 | for_each_online_node(i) { | |
778 | alc = alien[i]; | |
779 | if (alc) { | |
780 | LIST_HEAD(list); | |
781 | ||
782 | ac = &alc->ac; | |
783 | spin_lock_irqsave(&alc->lock, flags); | |
784 | __drain_alien_cache(cachep, ac, i, &list); | |
785 | spin_unlock_irqrestore(&alc->lock, flags); | |
786 | slabs_destroy(cachep, &list); | |
787 | } | |
788 | } | |
789 | } | |
790 | ||
791 | static int __cache_free_alien(struct kmem_cache *cachep, void *objp, | |
792 | int node, int page_node) | |
793 | { | |
794 | struct kmem_cache_node *n; | |
795 | struct alien_cache *alien = NULL; | |
796 | struct array_cache *ac; | |
797 | LIST_HEAD(list); | |
798 | ||
799 | n = get_node(cachep, node); | |
800 | STATS_INC_NODEFREES(cachep); | |
801 | if (n->alien && n->alien[page_node]) { | |
802 | alien = n->alien[page_node]; | |
803 | ac = &alien->ac; | |
804 | spin_lock(&alien->lock); | |
805 | if (unlikely(ac->avail == ac->limit)) { | |
806 | STATS_INC_ACOVERFLOW(cachep); | |
807 | __drain_alien_cache(cachep, ac, page_node, &list); | |
808 | } | |
809 | ac->entry[ac->avail++] = objp; | |
810 | spin_unlock(&alien->lock); | |
811 | slabs_destroy(cachep, &list); | |
812 | } else { | |
813 | n = get_node(cachep, page_node); | |
814 | spin_lock(&n->list_lock); | |
815 | free_block(cachep, &objp, 1, page_node, &list); | |
816 | spin_unlock(&n->list_lock); | |
817 | slabs_destroy(cachep, &list); | |
818 | } | |
819 | return 1; | |
820 | } | |
821 | ||
822 | static inline int cache_free_alien(struct kmem_cache *cachep, void *objp) | |
823 | { | |
824 | int page_node = page_to_nid(virt_to_page(objp)); | |
825 | int node = numa_mem_id(); | |
826 | /* | |
827 | * Make sure we are not freeing a object from another node to the array | |
828 | * cache on this cpu. | |
829 | */ | |
830 | if (likely(node == page_node)) | |
831 | return 0; | |
832 | ||
833 | return __cache_free_alien(cachep, objp, node, page_node); | |
834 | } | |
835 | ||
836 | /* | |
837 | * Construct gfp mask to allocate from a specific node but do not reclaim or | |
838 | * warn about failures. | |
839 | */ | |
840 | static inline gfp_t gfp_exact_node(gfp_t flags) | |
841 | { | |
842 | return (flags | __GFP_THISNODE | __GFP_NOWARN) & ~(__GFP_RECLAIM|__GFP_NOFAIL); | |
843 | } | |
844 | #endif | |
845 | ||
846 | static int init_cache_node(struct kmem_cache *cachep, int node, gfp_t gfp) | |
847 | { | |
848 | struct kmem_cache_node *n; | |
849 | ||
850 | /* | |
851 | * Set up the kmem_cache_node for cpu before we can | |
852 | * begin anything. Make sure some other cpu on this | |
853 | * node has not already allocated this | |
854 | */ | |
855 | n = get_node(cachep, node); | |
856 | if (n) { | |
857 | spin_lock_irq(&n->list_lock); | |
858 | n->free_limit = (1 + nr_cpus_node(node)) * cachep->batchcount + | |
859 | cachep->num; | |
860 | spin_unlock_irq(&n->list_lock); | |
861 | ||
862 | return 0; | |
863 | } | |
864 | ||
865 | n = kmalloc_node(sizeof(struct kmem_cache_node), gfp, node); | |
866 | if (!n) | |
867 | return -ENOMEM; | |
868 | ||
869 | kmem_cache_node_init(n); | |
870 | n->next_reap = jiffies + REAPTIMEOUT_NODE + | |
871 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; | |
872 | ||
873 | n->free_limit = | |
874 | (1 + nr_cpus_node(node)) * cachep->batchcount + cachep->num; | |
875 | ||
876 | /* | |
877 | * The kmem_cache_nodes don't come and go as CPUs | |
878 | * come and go. slab_mutex is sufficient | |
879 | * protection here. | |
880 | */ | |
881 | cachep->node[node] = n; | |
882 | ||
883 | return 0; | |
884 | } | |
885 | ||
886 | #if (defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG)) || defined(CONFIG_SMP) | |
887 | /* | |
888 | * Allocates and initializes node for a node on each slab cache, used for | |
889 | * either memory or cpu hotplug. If memory is being hot-added, the kmem_cache_node | |
890 | * will be allocated off-node since memory is not yet online for the new node. | |
891 | * When hotplugging memory or a cpu, existing node are not replaced if | |
892 | * already in use. | |
893 | * | |
894 | * Must hold slab_mutex. | |
895 | */ | |
896 | static int init_cache_node_node(int node) | |
897 | { | |
898 | int ret; | |
899 | struct kmem_cache *cachep; | |
900 | ||
901 | list_for_each_entry(cachep, &slab_caches, list) { | |
902 | ret = init_cache_node(cachep, node, GFP_KERNEL); | |
903 | if (ret) | |
904 | return ret; | |
905 | } | |
906 | ||
907 | return 0; | |
908 | } | |
909 | #endif | |
910 | ||
911 | static int setup_kmem_cache_node(struct kmem_cache *cachep, | |
912 | int node, gfp_t gfp, bool force_change) | |
913 | { | |
914 | int ret = -ENOMEM; | |
915 | struct kmem_cache_node *n; | |
916 | struct array_cache *old_shared = NULL; | |
917 | struct array_cache *new_shared = NULL; | |
918 | struct alien_cache **new_alien = NULL; | |
919 | LIST_HEAD(list); | |
920 | ||
921 | if (use_alien_caches) { | |
922 | new_alien = alloc_alien_cache(node, cachep->limit, gfp); | |
923 | if (!new_alien) | |
924 | goto fail; | |
925 | } | |
926 | ||
927 | if (cachep->shared) { | |
928 | new_shared = alloc_arraycache(node, | |
929 | cachep->shared * cachep->batchcount, 0xbaadf00d, gfp); | |
930 | if (!new_shared) | |
931 | goto fail; | |
932 | } | |
933 | ||
934 | ret = init_cache_node(cachep, node, gfp); | |
935 | if (ret) | |
936 | goto fail; | |
937 | ||
938 | n = get_node(cachep, node); | |
939 | spin_lock_irq(&n->list_lock); | |
940 | if (n->shared && force_change) { | |
941 | free_block(cachep, n->shared->entry, | |
942 | n->shared->avail, node, &list); | |
943 | n->shared->avail = 0; | |
944 | } | |
945 | ||
946 | if (!n->shared || force_change) { | |
947 | old_shared = n->shared; | |
948 | n->shared = new_shared; | |
949 | new_shared = NULL; | |
950 | } | |
951 | ||
952 | if (!n->alien) { | |
953 | n->alien = new_alien; | |
954 | new_alien = NULL; | |
955 | } | |
956 | ||
957 | spin_unlock_irq(&n->list_lock); | |
958 | slabs_destroy(cachep, &list); | |
959 | ||
960 | /* | |
961 | * To protect lockless access to n->shared during irq disabled context. | |
962 | * If n->shared isn't NULL in irq disabled context, accessing to it is | |
963 | * guaranteed to be valid until irq is re-enabled, because it will be | |
964 | * freed after synchronize_sched(). | |
965 | */ | |
966 | if (old_shared && force_change) | |
967 | synchronize_sched(); | |
968 | ||
969 | fail: | |
970 | kfree(old_shared); | |
971 | kfree(new_shared); | |
972 | free_alien_cache(new_alien); | |
973 | ||
974 | return ret; | |
975 | } | |
976 | ||
977 | #ifdef CONFIG_SMP | |
978 | ||
979 | static void cpuup_canceled(long cpu) | |
980 | { | |
981 | struct kmem_cache *cachep; | |
982 | struct kmem_cache_node *n = NULL; | |
983 | int node = cpu_to_mem(cpu); | |
984 | const struct cpumask *mask = cpumask_of_node(node); | |
985 | ||
986 | list_for_each_entry(cachep, &slab_caches, list) { | |
987 | struct array_cache *nc; | |
988 | struct array_cache *shared; | |
989 | struct alien_cache **alien; | |
990 | LIST_HEAD(list); | |
991 | ||
992 | n = get_node(cachep, node); | |
993 | if (!n) | |
994 | continue; | |
995 | ||
996 | spin_lock_irq(&n->list_lock); | |
997 | ||
998 | /* Free limit for this kmem_cache_node */ | |
999 | n->free_limit -= cachep->batchcount; | |
1000 | ||
1001 | /* cpu is dead; no one can alloc from it. */ | |
1002 | nc = per_cpu_ptr(cachep->cpu_cache, cpu); | |
1003 | if (nc) { | |
1004 | free_block(cachep, nc->entry, nc->avail, node, &list); | |
1005 | nc->avail = 0; | |
1006 | } | |
1007 | ||
1008 | if (!cpumask_empty(mask)) { | |
1009 | spin_unlock_irq(&n->list_lock); | |
1010 | goto free_slab; | |
1011 | } | |
1012 | ||
1013 | shared = n->shared; | |
1014 | if (shared) { | |
1015 | free_block(cachep, shared->entry, | |
1016 | shared->avail, node, &list); | |
1017 | n->shared = NULL; | |
1018 | } | |
1019 | ||
1020 | alien = n->alien; | |
1021 | n->alien = NULL; | |
1022 | ||
1023 | spin_unlock_irq(&n->list_lock); | |
1024 | ||
1025 | kfree(shared); | |
1026 | if (alien) { | |
1027 | drain_alien_cache(cachep, alien); | |
1028 | free_alien_cache(alien); | |
1029 | } | |
1030 | ||
1031 | free_slab: | |
1032 | slabs_destroy(cachep, &list); | |
1033 | } | |
1034 | /* | |
1035 | * In the previous loop, all the objects were freed to | |
1036 | * the respective cache's slabs, now we can go ahead and | |
1037 | * shrink each nodelist to its limit. | |
1038 | */ | |
1039 | list_for_each_entry(cachep, &slab_caches, list) { | |
1040 | n = get_node(cachep, node); | |
1041 | if (!n) | |
1042 | continue; | |
1043 | drain_freelist(cachep, n, INT_MAX); | |
1044 | } | |
1045 | } | |
1046 | ||
1047 | static int cpuup_prepare(long cpu) | |
1048 | { | |
1049 | struct kmem_cache *cachep; | |
1050 | int node = cpu_to_mem(cpu); | |
1051 | int err; | |
1052 | ||
1053 | /* | |
1054 | * We need to do this right in the beginning since | |
1055 | * alloc_arraycache's are going to use this list. | |
1056 | * kmalloc_node allows us to add the slab to the right | |
1057 | * kmem_cache_node and not this cpu's kmem_cache_node | |
1058 | */ | |
1059 | err = init_cache_node_node(node); | |
1060 | if (err < 0) | |
1061 | goto bad; | |
1062 | ||
1063 | /* | |
1064 | * Now we can go ahead with allocating the shared arrays and | |
1065 | * array caches | |
1066 | */ | |
1067 | list_for_each_entry(cachep, &slab_caches, list) { | |
1068 | err = setup_kmem_cache_node(cachep, node, GFP_KERNEL, false); | |
1069 | if (err) | |
1070 | goto bad; | |
1071 | } | |
1072 | ||
1073 | return 0; | |
1074 | bad: | |
1075 | cpuup_canceled(cpu); | |
1076 | return -ENOMEM; | |
1077 | } | |
1078 | ||
1079 | int slab_prepare_cpu(unsigned int cpu) | |
1080 | { | |
1081 | int err; | |
1082 | ||
1083 | mutex_lock(&slab_mutex); | |
1084 | err = cpuup_prepare(cpu); | |
1085 | mutex_unlock(&slab_mutex); | |
1086 | return err; | |
1087 | } | |
1088 | ||
1089 | /* | |
1090 | * This is called for a failed online attempt and for a successful | |
1091 | * offline. | |
1092 | * | |
1093 | * Even if all the cpus of a node are down, we don't free the | |
1094 | * kmem_list3 of any cache. This to avoid a race between cpu_down, and | |
1095 | * a kmalloc allocation from another cpu for memory from the node of | |
1096 | * the cpu going down. The list3 structure is usually allocated from | |
1097 | * kmem_cache_create() and gets destroyed at kmem_cache_destroy(). | |
1098 | */ | |
1099 | int slab_dead_cpu(unsigned int cpu) | |
1100 | { | |
1101 | mutex_lock(&slab_mutex); | |
1102 | cpuup_canceled(cpu); | |
1103 | mutex_unlock(&slab_mutex); | |
1104 | return 0; | |
1105 | } | |
1106 | #endif | |
1107 | ||
1108 | static int slab_online_cpu(unsigned int cpu) | |
1109 | { | |
1110 | start_cpu_timer(cpu); | |
1111 | return 0; | |
1112 | } | |
1113 | ||
1114 | static int slab_offline_cpu(unsigned int cpu) | |
1115 | { | |
1116 | /* | |
1117 | * Shutdown cache reaper. Note that the slab_mutex is held so | |
1118 | * that if cache_reap() is invoked it cannot do anything | |
1119 | * expensive but will only modify reap_work and reschedule the | |
1120 | * timer. | |
1121 | */ | |
1122 | cancel_delayed_work_sync(&per_cpu(slab_reap_work, cpu)); | |
1123 | /* Now the cache_reaper is guaranteed to be not running. */ | |
1124 | per_cpu(slab_reap_work, cpu).work.func = NULL; | |
1125 | return 0; | |
1126 | } | |
1127 | ||
1128 | #if defined(CONFIG_NUMA) && defined(CONFIG_MEMORY_HOTPLUG) | |
1129 | /* | |
1130 | * Drains freelist for a node on each slab cache, used for memory hot-remove. | |
1131 | * Returns -EBUSY if all objects cannot be drained so that the node is not | |
1132 | * removed. | |
1133 | * | |
1134 | * Must hold slab_mutex. | |
1135 | */ | |
1136 | static int __meminit drain_cache_node_node(int node) | |
1137 | { | |
1138 | struct kmem_cache *cachep; | |
1139 | int ret = 0; | |
1140 | ||
1141 | list_for_each_entry(cachep, &slab_caches, list) { | |
1142 | struct kmem_cache_node *n; | |
1143 | ||
1144 | n = get_node(cachep, node); | |
1145 | if (!n) | |
1146 | continue; | |
1147 | ||
1148 | drain_freelist(cachep, n, INT_MAX); | |
1149 | ||
1150 | if (!list_empty(&n->slabs_full) || | |
1151 | !list_empty(&n->slabs_partial)) { | |
1152 | ret = -EBUSY; | |
1153 | break; | |
1154 | } | |
1155 | } | |
1156 | return ret; | |
1157 | } | |
1158 | ||
1159 | static int __meminit slab_memory_callback(struct notifier_block *self, | |
1160 | unsigned long action, void *arg) | |
1161 | { | |
1162 | struct memory_notify *mnb = arg; | |
1163 | int ret = 0; | |
1164 | int nid; | |
1165 | ||
1166 | nid = mnb->status_change_nid; | |
1167 | if (nid < 0) | |
1168 | goto out; | |
1169 | ||
1170 | switch (action) { | |
1171 | case MEM_GOING_ONLINE: | |
1172 | mutex_lock(&slab_mutex); | |
1173 | ret = init_cache_node_node(nid); | |
1174 | mutex_unlock(&slab_mutex); | |
1175 | break; | |
1176 | case MEM_GOING_OFFLINE: | |
1177 | mutex_lock(&slab_mutex); | |
1178 | ret = drain_cache_node_node(nid); | |
1179 | mutex_unlock(&slab_mutex); | |
1180 | break; | |
1181 | case MEM_ONLINE: | |
1182 | case MEM_OFFLINE: | |
1183 | case MEM_CANCEL_ONLINE: | |
1184 | case MEM_CANCEL_OFFLINE: | |
1185 | break; | |
1186 | } | |
1187 | out: | |
1188 | return notifier_from_errno(ret); | |
1189 | } | |
1190 | #endif /* CONFIG_NUMA && CONFIG_MEMORY_HOTPLUG */ | |
1191 | ||
1192 | /* | |
1193 | * swap the static kmem_cache_node with kmalloced memory | |
1194 | */ | |
1195 | static void __init init_list(struct kmem_cache *cachep, struct kmem_cache_node *list, | |
1196 | int nodeid) | |
1197 | { | |
1198 | struct kmem_cache_node *ptr; | |
1199 | ||
1200 | ptr = kmalloc_node(sizeof(struct kmem_cache_node), GFP_NOWAIT, nodeid); | |
1201 | BUG_ON(!ptr); | |
1202 | ||
1203 | memcpy(ptr, list, sizeof(struct kmem_cache_node)); | |
1204 | /* | |
1205 | * Do not assume that spinlocks can be initialized via memcpy: | |
1206 | */ | |
1207 | spin_lock_init(&ptr->list_lock); | |
1208 | ||
1209 | MAKE_ALL_LISTS(cachep, ptr, nodeid); | |
1210 | cachep->node[nodeid] = ptr; | |
1211 | } | |
1212 | ||
1213 | /* | |
1214 | * For setting up all the kmem_cache_node for cache whose buffer_size is same as | |
1215 | * size of kmem_cache_node. | |
1216 | */ | |
1217 | static void __init set_up_node(struct kmem_cache *cachep, int index) | |
1218 | { | |
1219 | int node; | |
1220 | ||
1221 | for_each_online_node(node) { | |
1222 | cachep->node[node] = &init_kmem_cache_node[index + node]; | |
1223 | cachep->node[node]->next_reap = jiffies + | |
1224 | REAPTIMEOUT_NODE + | |
1225 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; | |
1226 | } | |
1227 | } | |
1228 | ||
1229 | /* | |
1230 | * Initialisation. Called after the page allocator have been initialised and | |
1231 | * before smp_init(). | |
1232 | */ | |
1233 | void __init kmem_cache_init(void) | |
1234 | { | |
1235 | int i; | |
1236 | ||
1237 | BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) < | |
1238 | sizeof(struct rcu_head)); | |
1239 | kmem_cache = &kmem_cache_boot; | |
1240 | ||
1241 | if (!IS_ENABLED(CONFIG_NUMA) || num_possible_nodes() == 1) | |
1242 | use_alien_caches = 0; | |
1243 | ||
1244 | for (i = 0; i < NUM_INIT_LISTS; i++) | |
1245 | kmem_cache_node_init(&init_kmem_cache_node[i]); | |
1246 | ||
1247 | /* | |
1248 | * Fragmentation resistance on low memory - only use bigger | |
1249 | * page orders on machines with more than 32MB of memory if | |
1250 | * not overridden on the command line. | |
1251 | */ | |
1252 | if (!slab_max_order_set && totalram_pages > (32 << 20) >> PAGE_SHIFT) | |
1253 | slab_max_order = SLAB_MAX_ORDER_HI; | |
1254 | ||
1255 | /* Bootstrap is tricky, because several objects are allocated | |
1256 | * from caches that do not exist yet: | |
1257 | * 1) initialize the kmem_cache cache: it contains the struct | |
1258 | * kmem_cache structures of all caches, except kmem_cache itself: | |
1259 | * kmem_cache is statically allocated. | |
1260 | * Initially an __init data area is used for the head array and the | |
1261 | * kmem_cache_node structures, it's replaced with a kmalloc allocated | |
1262 | * array at the end of the bootstrap. | |
1263 | * 2) Create the first kmalloc cache. | |
1264 | * The struct kmem_cache for the new cache is allocated normally. | |
1265 | * An __init data area is used for the head array. | |
1266 | * 3) Create the remaining kmalloc caches, with minimally sized | |
1267 | * head arrays. | |
1268 | * 4) Replace the __init data head arrays for kmem_cache and the first | |
1269 | * kmalloc cache with kmalloc allocated arrays. | |
1270 | * 5) Replace the __init data for kmem_cache_node for kmem_cache and | |
1271 | * the other cache's with kmalloc allocated memory. | |
1272 | * 6) Resize the head arrays of the kmalloc caches to their final sizes. | |
1273 | */ | |
1274 | ||
1275 | /* 1) create the kmem_cache */ | |
1276 | ||
1277 | /* | |
1278 | * struct kmem_cache size depends on nr_node_ids & nr_cpu_ids | |
1279 | */ | |
1280 | create_boot_cache(kmem_cache, "kmem_cache", | |
1281 | offsetof(struct kmem_cache, node) + | |
1282 | nr_node_ids * sizeof(struct kmem_cache_node *), | |
1283 | SLAB_HWCACHE_ALIGN); | |
1284 | list_add(&kmem_cache->list, &slab_caches); | |
1285 | slab_state = PARTIAL; | |
1286 | ||
1287 | /* | |
1288 | * Initialize the caches that provide memory for the kmem_cache_node | |
1289 | * structures first. Without this, further allocations will bug. | |
1290 | */ | |
1291 | kmalloc_caches[INDEX_NODE] = create_kmalloc_cache("kmalloc-node", | |
1292 | kmalloc_size(INDEX_NODE), ARCH_KMALLOC_FLAGS); | |
1293 | slab_state = PARTIAL_NODE; | |
1294 | setup_kmalloc_cache_index_table(); | |
1295 | ||
1296 | slab_early_init = 0; | |
1297 | ||
1298 | /* 5) Replace the bootstrap kmem_cache_node */ | |
1299 | { | |
1300 | int nid; | |
1301 | ||
1302 | for_each_online_node(nid) { | |
1303 | init_list(kmem_cache, &init_kmem_cache_node[CACHE_CACHE + nid], nid); | |
1304 | ||
1305 | init_list(kmalloc_caches[INDEX_NODE], | |
1306 | &init_kmem_cache_node[SIZE_NODE + nid], nid); | |
1307 | } | |
1308 | } | |
1309 | ||
1310 | create_kmalloc_caches(ARCH_KMALLOC_FLAGS); | |
1311 | } | |
1312 | ||
1313 | void __init kmem_cache_init_late(void) | |
1314 | { | |
1315 | struct kmem_cache *cachep; | |
1316 | ||
1317 | slab_state = UP; | |
1318 | ||
1319 | /* 6) resize the head arrays to their final sizes */ | |
1320 | mutex_lock(&slab_mutex); | |
1321 | list_for_each_entry(cachep, &slab_caches, list) | |
1322 | if (enable_cpucache(cachep, GFP_NOWAIT)) | |
1323 | BUG(); | |
1324 | mutex_unlock(&slab_mutex); | |
1325 | ||
1326 | /* Done! */ | |
1327 | slab_state = FULL; | |
1328 | ||
1329 | #ifdef CONFIG_NUMA | |
1330 | /* | |
1331 | * Register a memory hotplug callback that initializes and frees | |
1332 | * node. | |
1333 | */ | |
1334 | hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI); | |
1335 | #endif | |
1336 | ||
1337 | /* | |
1338 | * The reap timers are started later, with a module init call: That part | |
1339 | * of the kernel is not yet operational. | |
1340 | */ | |
1341 | } | |
1342 | ||
1343 | static int __init cpucache_init(void) | |
1344 | { | |
1345 | int ret; | |
1346 | ||
1347 | /* | |
1348 | * Register the timers that return unneeded pages to the page allocator | |
1349 | */ | |
1350 | ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "SLAB online", | |
1351 | slab_online_cpu, slab_offline_cpu); | |
1352 | WARN_ON(ret < 0); | |
1353 | ||
1354 | /* Done! */ | |
1355 | slab_state = FULL; | |
1356 | return 0; | |
1357 | } | |
1358 | __initcall(cpucache_init); | |
1359 | ||
1360 | static noinline void | |
1361 | slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid) | |
1362 | { | |
1363 | #if DEBUG | |
1364 | struct kmem_cache_node *n; | |
1365 | unsigned long flags; | |
1366 | int node; | |
1367 | static DEFINE_RATELIMIT_STATE(slab_oom_rs, DEFAULT_RATELIMIT_INTERVAL, | |
1368 | DEFAULT_RATELIMIT_BURST); | |
1369 | ||
1370 | if ((gfpflags & __GFP_NOWARN) || !__ratelimit(&slab_oom_rs)) | |
1371 | return; | |
1372 | ||
1373 | pr_warn("SLAB: Unable to allocate memory on node %d, gfp=%#x(%pGg)\n", | |
1374 | nodeid, gfpflags, &gfpflags); | |
1375 | pr_warn(" cache: %s, object size: %d, order: %d\n", | |
1376 | cachep->name, cachep->size, cachep->gfporder); | |
1377 | ||
1378 | for_each_kmem_cache_node(cachep, node, n) { | |
1379 | unsigned long total_slabs, free_slabs, free_objs; | |
1380 | ||
1381 | spin_lock_irqsave(&n->list_lock, flags); | |
1382 | total_slabs = n->total_slabs; | |
1383 | free_slabs = n->free_slabs; | |
1384 | free_objs = n->free_objects; | |
1385 | spin_unlock_irqrestore(&n->list_lock, flags); | |
1386 | ||
1387 | pr_warn(" node %d: slabs: %ld/%ld, objs: %ld/%ld\n", | |
1388 | node, total_slabs - free_slabs, total_slabs, | |
1389 | (total_slabs * cachep->num) - free_objs, | |
1390 | total_slabs * cachep->num); | |
1391 | } | |
1392 | #endif | |
1393 | } | |
1394 | ||
1395 | /* | |
1396 | * Interface to system's page allocator. No need to hold the | |
1397 | * kmem_cache_node ->list_lock. | |
1398 | * | |
1399 | * If we requested dmaable memory, we will get it. Even if we | |
1400 | * did not request dmaable memory, we might get it, but that | |
1401 | * would be relatively rare and ignorable. | |
1402 | */ | |
1403 | static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, | |
1404 | int nodeid) | |
1405 | { | |
1406 | struct page *page; | |
1407 | int nr_pages; | |
1408 | ||
1409 | flags |= cachep->allocflags; | |
1410 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1411 | flags |= __GFP_RECLAIMABLE; | |
1412 | ||
1413 | page = __alloc_pages_node(nodeid, flags | __GFP_NOTRACK, cachep->gfporder); | |
1414 | if (!page) { | |
1415 | slab_out_of_memory(cachep, flags, nodeid); | |
1416 | return NULL; | |
1417 | } | |
1418 | ||
1419 | if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) { | |
1420 | __free_pages(page, cachep->gfporder); | |
1421 | return NULL; | |
1422 | } | |
1423 | ||
1424 | nr_pages = (1 << cachep->gfporder); | |
1425 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1426 | add_zone_page_state(page_zone(page), | |
1427 | NR_SLAB_RECLAIMABLE, nr_pages); | |
1428 | else | |
1429 | add_zone_page_state(page_zone(page), | |
1430 | NR_SLAB_UNRECLAIMABLE, nr_pages); | |
1431 | ||
1432 | __SetPageSlab(page); | |
1433 | /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ | |
1434 | if (sk_memalloc_socks() && page_is_pfmemalloc(page)) | |
1435 | SetPageSlabPfmemalloc(page); | |
1436 | ||
1437 | if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { | |
1438 | kmemcheck_alloc_shadow(page, cachep->gfporder, flags, nodeid); | |
1439 | ||
1440 | if (cachep->ctor) | |
1441 | kmemcheck_mark_uninitialized_pages(page, nr_pages); | |
1442 | else | |
1443 | kmemcheck_mark_unallocated_pages(page, nr_pages); | |
1444 | } | |
1445 | ||
1446 | return page; | |
1447 | } | |
1448 | ||
1449 | /* | |
1450 | * Interface to system's page release. | |
1451 | */ | |
1452 | static void kmem_freepages(struct kmem_cache *cachep, struct page *page) | |
1453 | { | |
1454 | int order = cachep->gfporder; | |
1455 | unsigned long nr_freed = (1 << order); | |
1456 | ||
1457 | kmemcheck_free_shadow(page, order); | |
1458 | ||
1459 | if (cachep->flags & SLAB_RECLAIM_ACCOUNT) | |
1460 | sub_zone_page_state(page_zone(page), | |
1461 | NR_SLAB_RECLAIMABLE, nr_freed); | |
1462 | else | |
1463 | sub_zone_page_state(page_zone(page), | |
1464 | NR_SLAB_UNRECLAIMABLE, nr_freed); | |
1465 | ||
1466 | BUG_ON(!PageSlab(page)); | |
1467 | __ClearPageSlabPfmemalloc(page); | |
1468 | __ClearPageSlab(page); | |
1469 | page_mapcount_reset(page); | |
1470 | page->mapping = NULL; | |
1471 | ||
1472 | if (current->reclaim_state) | |
1473 | current->reclaim_state->reclaimed_slab += nr_freed; | |
1474 | memcg_uncharge_slab(page, order, cachep); | |
1475 | __free_pages(page, order); | |
1476 | } | |
1477 | ||
1478 | static void kmem_rcu_free(struct rcu_head *head) | |
1479 | { | |
1480 | struct kmem_cache *cachep; | |
1481 | struct page *page; | |
1482 | ||
1483 | page = container_of(head, struct page, rcu_head); | |
1484 | cachep = page->slab_cache; | |
1485 | ||
1486 | kmem_freepages(cachep, page); | |
1487 | } | |
1488 | ||
1489 | #if DEBUG | |
1490 | static bool is_debug_pagealloc_cache(struct kmem_cache *cachep) | |
1491 | { | |
1492 | if (debug_pagealloc_enabled() && OFF_SLAB(cachep) && | |
1493 | (cachep->size % PAGE_SIZE) == 0) | |
1494 | return true; | |
1495 | ||
1496 | return false; | |
1497 | } | |
1498 | ||
1499 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
1500 | static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, | |
1501 | unsigned long caller) | |
1502 | { | |
1503 | int size = cachep->object_size; | |
1504 | ||
1505 | addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; | |
1506 | ||
1507 | if (size < 5 * sizeof(unsigned long)) | |
1508 | return; | |
1509 | ||
1510 | *addr++ = 0x12345678; | |
1511 | *addr++ = caller; | |
1512 | *addr++ = smp_processor_id(); | |
1513 | size -= 3 * sizeof(unsigned long); | |
1514 | { | |
1515 | unsigned long *sptr = &caller; | |
1516 | unsigned long svalue; | |
1517 | ||
1518 | while (!kstack_end(sptr)) { | |
1519 | svalue = *sptr++; | |
1520 | if (kernel_text_address(svalue)) { | |
1521 | *addr++ = svalue; | |
1522 | size -= sizeof(unsigned long); | |
1523 | if (size <= sizeof(unsigned long)) | |
1524 | break; | |
1525 | } | |
1526 | } | |
1527 | ||
1528 | } | |
1529 | *addr++ = 0x87654321; | |
1530 | } | |
1531 | ||
1532 | static void slab_kernel_map(struct kmem_cache *cachep, void *objp, | |
1533 | int map, unsigned long caller) | |
1534 | { | |
1535 | if (!is_debug_pagealloc_cache(cachep)) | |
1536 | return; | |
1537 | ||
1538 | if (caller) | |
1539 | store_stackinfo(cachep, objp, caller); | |
1540 | ||
1541 | kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map); | |
1542 | } | |
1543 | ||
1544 | #else | |
1545 | static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp, | |
1546 | int map, unsigned long caller) {} | |
1547 | ||
1548 | #endif | |
1549 | ||
1550 | static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) | |
1551 | { | |
1552 | int size = cachep->object_size; | |
1553 | addr = &((char *)addr)[obj_offset(cachep)]; | |
1554 | ||
1555 | memset(addr, val, size); | |
1556 | *(unsigned char *)(addr + size - 1) = POISON_END; | |
1557 | } | |
1558 | ||
1559 | static void dump_line(char *data, int offset, int limit) | |
1560 | { | |
1561 | int i; | |
1562 | unsigned char error = 0; | |
1563 | int bad_count = 0; | |
1564 | ||
1565 | pr_err("%03x: ", offset); | |
1566 | for (i = 0; i < limit; i++) { | |
1567 | if (data[offset + i] != POISON_FREE) { | |
1568 | error = data[offset + i]; | |
1569 | bad_count++; | |
1570 | } | |
1571 | } | |
1572 | print_hex_dump(KERN_CONT, "", 0, 16, 1, | |
1573 | &data[offset], limit, 1); | |
1574 | ||
1575 | if (bad_count == 1) { | |
1576 | error ^= POISON_FREE; | |
1577 | if (!(error & (error - 1))) { | |
1578 | pr_err("Single bit error detected. Probably bad RAM.\n"); | |
1579 | #ifdef CONFIG_X86 | |
1580 | pr_err("Run memtest86+ or a similar memory test tool.\n"); | |
1581 | #else | |
1582 | pr_err("Run a memory test tool.\n"); | |
1583 | #endif | |
1584 | } | |
1585 | } | |
1586 | } | |
1587 | #endif | |
1588 | ||
1589 | #if DEBUG | |
1590 | ||
1591 | static void print_objinfo(struct kmem_cache *cachep, void *objp, int lines) | |
1592 | { | |
1593 | int i, size; | |
1594 | char *realobj; | |
1595 | ||
1596 | if (cachep->flags & SLAB_RED_ZONE) { | |
1597 | pr_err("Redzone: 0x%llx/0x%llx\n", | |
1598 | *dbg_redzone1(cachep, objp), | |
1599 | *dbg_redzone2(cachep, objp)); | |
1600 | } | |
1601 | ||
1602 | if (cachep->flags & SLAB_STORE_USER) { | |
1603 | pr_err("Last user: [<%p>](%pSR)\n", | |
1604 | *dbg_userword(cachep, objp), | |
1605 | *dbg_userword(cachep, objp)); | |
1606 | } | |
1607 | realobj = (char *)objp + obj_offset(cachep); | |
1608 | size = cachep->object_size; | |
1609 | for (i = 0; i < size && lines; i += 16, lines--) { | |
1610 | int limit; | |
1611 | limit = 16; | |
1612 | if (i + limit > size) | |
1613 | limit = size - i; | |
1614 | dump_line(realobj, i, limit); | |
1615 | } | |
1616 | } | |
1617 | ||
1618 | static void check_poison_obj(struct kmem_cache *cachep, void *objp) | |
1619 | { | |
1620 | char *realobj; | |
1621 | int size, i; | |
1622 | int lines = 0; | |
1623 | ||
1624 | if (is_debug_pagealloc_cache(cachep)) | |
1625 | return; | |
1626 | ||
1627 | realobj = (char *)objp + obj_offset(cachep); | |
1628 | size = cachep->object_size; | |
1629 | ||
1630 | for (i = 0; i < size; i++) { | |
1631 | char exp = POISON_FREE; | |
1632 | if (i == size - 1) | |
1633 | exp = POISON_END; | |
1634 | if (realobj[i] != exp) { | |
1635 | int limit; | |
1636 | /* Mismatch ! */ | |
1637 | /* Print header */ | |
1638 | if (lines == 0) { | |
1639 | pr_err("Slab corruption (%s): %s start=%p, len=%d\n", | |
1640 | print_tainted(), cachep->name, | |
1641 | realobj, size); | |
1642 | print_objinfo(cachep, objp, 0); | |
1643 | } | |
1644 | /* Hexdump the affected line */ | |
1645 | i = (i / 16) * 16; | |
1646 | limit = 16; | |
1647 | if (i + limit > size) | |
1648 | limit = size - i; | |
1649 | dump_line(realobj, i, limit); | |
1650 | i += 16; | |
1651 | lines++; | |
1652 | /* Limit to 5 lines */ | |
1653 | if (lines > 5) | |
1654 | break; | |
1655 | } | |
1656 | } | |
1657 | if (lines != 0) { | |
1658 | /* Print some data about the neighboring objects, if they | |
1659 | * exist: | |
1660 | */ | |
1661 | struct page *page = virt_to_head_page(objp); | |
1662 | unsigned int objnr; | |
1663 | ||
1664 | objnr = obj_to_index(cachep, page, objp); | |
1665 | if (objnr) { | |
1666 | objp = index_to_obj(cachep, page, objnr - 1); | |
1667 | realobj = (char *)objp + obj_offset(cachep); | |
1668 | pr_err("Prev obj: start=%p, len=%d\n", realobj, size); | |
1669 | print_objinfo(cachep, objp, 2); | |
1670 | } | |
1671 | if (objnr + 1 < cachep->num) { | |
1672 | objp = index_to_obj(cachep, page, objnr + 1); | |
1673 | realobj = (char *)objp + obj_offset(cachep); | |
1674 | pr_err("Next obj: start=%p, len=%d\n", realobj, size); | |
1675 | print_objinfo(cachep, objp, 2); | |
1676 | } | |
1677 | } | |
1678 | } | |
1679 | #endif | |
1680 | ||
1681 | #if DEBUG | |
1682 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, | |
1683 | struct page *page) | |
1684 | { | |
1685 | int i; | |
1686 | ||
1687 | if (OBJFREELIST_SLAB(cachep) && cachep->flags & SLAB_POISON) { | |
1688 | poison_obj(cachep, page->freelist - obj_offset(cachep), | |
1689 | POISON_FREE); | |
1690 | } | |
1691 | ||
1692 | for (i = 0; i < cachep->num; i++) { | |
1693 | void *objp = index_to_obj(cachep, page, i); | |
1694 | ||
1695 | if (cachep->flags & SLAB_POISON) { | |
1696 | check_poison_obj(cachep, objp); | |
1697 | slab_kernel_map(cachep, objp, 1, 0); | |
1698 | } | |
1699 | if (cachep->flags & SLAB_RED_ZONE) { | |
1700 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
1701 | slab_error(cachep, "start of a freed object was overwritten"); | |
1702 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
1703 | slab_error(cachep, "end of a freed object was overwritten"); | |
1704 | } | |
1705 | } | |
1706 | } | |
1707 | #else | |
1708 | static void slab_destroy_debugcheck(struct kmem_cache *cachep, | |
1709 | struct page *page) | |
1710 | { | |
1711 | } | |
1712 | #endif | |
1713 | ||
1714 | /** | |
1715 | * slab_destroy - destroy and release all objects in a slab | |
1716 | * @cachep: cache pointer being destroyed | |
1717 | * @page: page pointer being destroyed | |
1718 | * | |
1719 | * Destroy all the objs in a slab page, and release the mem back to the system. | |
1720 | * Before calling the slab page must have been unlinked from the cache. The | |
1721 | * kmem_cache_node ->list_lock is not held/needed. | |
1722 | */ | |
1723 | static void slab_destroy(struct kmem_cache *cachep, struct page *page) | |
1724 | { | |
1725 | void *freelist; | |
1726 | ||
1727 | freelist = page->freelist; | |
1728 | slab_destroy_debugcheck(cachep, page); | |
1729 | if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) | |
1730 | call_rcu(&page->rcu_head, kmem_rcu_free); | |
1731 | else | |
1732 | kmem_freepages(cachep, page); | |
1733 | ||
1734 | /* | |
1735 | * From now on, we don't use freelist | |
1736 | * although actual page can be freed in rcu context | |
1737 | */ | |
1738 | if (OFF_SLAB(cachep)) | |
1739 | kmem_cache_free(cachep->freelist_cache, freelist); | |
1740 | } | |
1741 | ||
1742 | static void slabs_destroy(struct kmem_cache *cachep, struct list_head *list) | |
1743 | { | |
1744 | struct page *page, *n; | |
1745 | ||
1746 | list_for_each_entry_safe(page, n, list, lru) { | |
1747 | list_del(&page->lru); | |
1748 | slab_destroy(cachep, page); | |
1749 | } | |
1750 | } | |
1751 | ||
1752 | /** | |
1753 | * calculate_slab_order - calculate size (page order) of slabs | |
1754 | * @cachep: pointer to the cache that is being created | |
1755 | * @size: size of objects to be created in this cache. | |
1756 | * @flags: slab allocation flags | |
1757 | * | |
1758 | * Also calculates the number of objects per slab. | |
1759 | * | |
1760 | * This could be made much more intelligent. For now, try to avoid using | |
1761 | * high order pages for slabs. When the gfp() functions are more friendly | |
1762 | * towards high-order requests, this should be changed. | |
1763 | */ | |
1764 | static size_t calculate_slab_order(struct kmem_cache *cachep, | |
1765 | size_t size, unsigned long flags) | |
1766 | { | |
1767 | size_t left_over = 0; | |
1768 | int gfporder; | |
1769 | ||
1770 | for (gfporder = 0; gfporder <= KMALLOC_MAX_ORDER; gfporder++) { | |
1771 | unsigned int num; | |
1772 | size_t remainder; | |
1773 | ||
1774 | num = cache_estimate(gfporder, size, flags, &remainder); | |
1775 | if (!num) | |
1776 | continue; | |
1777 | ||
1778 | /* Can't handle number of objects more than SLAB_OBJ_MAX_NUM */ | |
1779 | if (num > SLAB_OBJ_MAX_NUM) | |
1780 | break; | |
1781 | ||
1782 | if (flags & CFLGS_OFF_SLAB) { | |
1783 | struct kmem_cache *freelist_cache; | |
1784 | size_t freelist_size; | |
1785 | ||
1786 | freelist_size = num * sizeof(freelist_idx_t); | |
1787 | freelist_cache = kmalloc_slab(freelist_size, 0u); | |
1788 | if (!freelist_cache) | |
1789 | continue; | |
1790 | ||
1791 | /* | |
1792 | * Needed to avoid possible looping condition | |
1793 | * in cache_grow_begin() | |
1794 | */ | |
1795 | if (OFF_SLAB(freelist_cache)) | |
1796 | continue; | |
1797 | ||
1798 | /* check if off slab has enough benefit */ | |
1799 | if (freelist_cache->size > cachep->size / 2) | |
1800 | continue; | |
1801 | } | |
1802 | ||
1803 | /* Found something acceptable - save it away */ | |
1804 | cachep->num = num; | |
1805 | cachep->gfporder = gfporder; | |
1806 | left_over = remainder; | |
1807 | ||
1808 | /* | |
1809 | * A VFS-reclaimable slab tends to have most allocations | |
1810 | * as GFP_NOFS and we really don't want to have to be allocating | |
1811 | * higher-order pages when we are unable to shrink dcache. | |
1812 | */ | |
1813 | if (flags & SLAB_RECLAIM_ACCOUNT) | |
1814 | break; | |
1815 | ||
1816 | /* | |
1817 | * Large number of objects is good, but very large slabs are | |
1818 | * currently bad for the gfp()s. | |
1819 | */ | |
1820 | if (gfporder >= slab_max_order) | |
1821 | break; | |
1822 | ||
1823 | /* | |
1824 | * Acceptable internal fragmentation? | |
1825 | */ | |
1826 | if (left_over * 8 <= (PAGE_SIZE << gfporder)) | |
1827 | break; | |
1828 | } | |
1829 | return left_over; | |
1830 | } | |
1831 | ||
1832 | static struct array_cache __percpu *alloc_kmem_cache_cpus( | |
1833 | struct kmem_cache *cachep, int entries, int batchcount) | |
1834 | { | |
1835 | int cpu; | |
1836 | size_t size; | |
1837 | struct array_cache __percpu *cpu_cache; | |
1838 | ||
1839 | size = sizeof(void *) * entries + sizeof(struct array_cache); | |
1840 | cpu_cache = __alloc_percpu(size, sizeof(void *)); | |
1841 | ||
1842 | if (!cpu_cache) | |
1843 | return NULL; | |
1844 | ||
1845 | for_each_possible_cpu(cpu) { | |
1846 | init_arraycache(per_cpu_ptr(cpu_cache, cpu), | |
1847 | entries, batchcount); | |
1848 | } | |
1849 | ||
1850 | return cpu_cache; | |
1851 | } | |
1852 | ||
1853 | static int __ref setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) | |
1854 | { | |
1855 | if (slab_state >= FULL) | |
1856 | return enable_cpucache(cachep, gfp); | |
1857 | ||
1858 | cachep->cpu_cache = alloc_kmem_cache_cpus(cachep, 1, 1); | |
1859 | if (!cachep->cpu_cache) | |
1860 | return 1; | |
1861 | ||
1862 | if (slab_state == DOWN) { | |
1863 | /* Creation of first cache (kmem_cache). */ | |
1864 | set_up_node(kmem_cache, CACHE_CACHE); | |
1865 | } else if (slab_state == PARTIAL) { | |
1866 | /* For kmem_cache_node */ | |
1867 | set_up_node(cachep, SIZE_NODE); | |
1868 | } else { | |
1869 | int node; | |
1870 | ||
1871 | for_each_online_node(node) { | |
1872 | cachep->node[node] = kmalloc_node( | |
1873 | sizeof(struct kmem_cache_node), gfp, node); | |
1874 | BUG_ON(!cachep->node[node]); | |
1875 | kmem_cache_node_init(cachep->node[node]); | |
1876 | } | |
1877 | } | |
1878 | ||
1879 | cachep->node[numa_mem_id()]->next_reap = | |
1880 | jiffies + REAPTIMEOUT_NODE + | |
1881 | ((unsigned long)cachep) % REAPTIMEOUT_NODE; | |
1882 | ||
1883 | cpu_cache_get(cachep)->avail = 0; | |
1884 | cpu_cache_get(cachep)->limit = BOOT_CPUCACHE_ENTRIES; | |
1885 | cpu_cache_get(cachep)->batchcount = 1; | |
1886 | cpu_cache_get(cachep)->touched = 0; | |
1887 | cachep->batchcount = 1; | |
1888 | cachep->limit = BOOT_CPUCACHE_ENTRIES; | |
1889 | return 0; | |
1890 | } | |
1891 | ||
1892 | unsigned long kmem_cache_flags(unsigned long object_size, | |
1893 | unsigned long flags, const char *name, | |
1894 | void (*ctor)(void *)) | |
1895 | { | |
1896 | return flags; | |
1897 | } | |
1898 | ||
1899 | struct kmem_cache * | |
1900 | __kmem_cache_alias(const char *name, size_t size, size_t align, | |
1901 | unsigned long flags, void (*ctor)(void *)) | |
1902 | { | |
1903 | struct kmem_cache *cachep; | |
1904 | ||
1905 | cachep = find_mergeable(size, align, flags, name, ctor); | |
1906 | if (cachep) { | |
1907 | cachep->refcount++; | |
1908 | ||
1909 | /* | |
1910 | * Adjust the object sizes so that we clear | |
1911 | * the complete object on kzalloc. | |
1912 | */ | |
1913 | cachep->object_size = max_t(int, cachep->object_size, size); | |
1914 | } | |
1915 | return cachep; | |
1916 | } | |
1917 | ||
1918 | static bool set_objfreelist_slab_cache(struct kmem_cache *cachep, | |
1919 | size_t size, unsigned long flags) | |
1920 | { | |
1921 | size_t left; | |
1922 | ||
1923 | cachep->num = 0; | |
1924 | ||
1925 | if (cachep->ctor || flags & SLAB_DESTROY_BY_RCU) | |
1926 | return false; | |
1927 | ||
1928 | left = calculate_slab_order(cachep, size, | |
1929 | flags | CFLGS_OBJFREELIST_SLAB); | |
1930 | if (!cachep->num) | |
1931 | return false; | |
1932 | ||
1933 | if (cachep->num * sizeof(freelist_idx_t) > cachep->object_size) | |
1934 | return false; | |
1935 | ||
1936 | cachep->colour = left / cachep->colour_off; | |
1937 | ||
1938 | return true; | |
1939 | } | |
1940 | ||
1941 | static bool set_off_slab_cache(struct kmem_cache *cachep, | |
1942 | size_t size, unsigned long flags) | |
1943 | { | |
1944 | size_t left; | |
1945 | ||
1946 | cachep->num = 0; | |
1947 | ||
1948 | /* | |
1949 | * Always use on-slab management when SLAB_NOLEAKTRACE | |
1950 | * to avoid recursive calls into kmemleak. | |
1951 | */ | |
1952 | if (flags & SLAB_NOLEAKTRACE) | |
1953 | return false; | |
1954 | ||
1955 | /* | |
1956 | * Size is large, assume best to place the slab management obj | |
1957 | * off-slab (should allow better packing of objs). | |
1958 | */ | |
1959 | left = calculate_slab_order(cachep, size, flags | CFLGS_OFF_SLAB); | |
1960 | if (!cachep->num) | |
1961 | return false; | |
1962 | ||
1963 | /* | |
1964 | * If the slab has been placed off-slab, and we have enough space then | |
1965 | * move it on-slab. This is at the expense of any extra colouring. | |
1966 | */ | |
1967 | if (left >= cachep->num * sizeof(freelist_idx_t)) | |
1968 | return false; | |
1969 | ||
1970 | cachep->colour = left / cachep->colour_off; | |
1971 | ||
1972 | return true; | |
1973 | } | |
1974 | ||
1975 | static bool set_on_slab_cache(struct kmem_cache *cachep, | |
1976 | size_t size, unsigned long flags) | |
1977 | { | |
1978 | size_t left; | |
1979 | ||
1980 | cachep->num = 0; | |
1981 | ||
1982 | left = calculate_slab_order(cachep, size, flags); | |
1983 | if (!cachep->num) | |
1984 | return false; | |
1985 | ||
1986 | cachep->colour = left / cachep->colour_off; | |
1987 | ||
1988 | return true; | |
1989 | } | |
1990 | ||
1991 | /** | |
1992 | * __kmem_cache_create - Create a cache. | |
1993 | * @cachep: cache management descriptor | |
1994 | * @flags: SLAB flags | |
1995 | * | |
1996 | * Returns a ptr to the cache on success, NULL on failure. | |
1997 | * Cannot be called within a int, but can be interrupted. | |
1998 | * The @ctor is run when new pages are allocated by the cache. | |
1999 | * | |
2000 | * The flags are | |
2001 | * | |
2002 | * %SLAB_POISON - Poison the slab with a known test pattern (a5a5a5a5) | |
2003 | * to catch references to uninitialised memory. | |
2004 | * | |
2005 | * %SLAB_RED_ZONE - Insert `Red' zones around the allocated memory to check | |
2006 | * for buffer overruns. | |
2007 | * | |
2008 | * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware | |
2009 | * cacheline. This can be beneficial if you're counting cycles as closely | |
2010 | * as davem. | |
2011 | */ | |
2012 | int | |
2013 | __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) | |
2014 | { | |
2015 | size_t ralign = BYTES_PER_WORD; | |
2016 | gfp_t gfp; | |
2017 | int err; | |
2018 | size_t size = cachep->size; | |
2019 | ||
2020 | #if DEBUG | |
2021 | #if FORCED_DEBUG | |
2022 | /* | |
2023 | * Enable redzoning and last user accounting, except for caches with | |
2024 | * large objects, if the increased size would increase the object size | |
2025 | * above the next power of two: caches with object sizes just above a | |
2026 | * power of two have a significant amount of internal fragmentation. | |
2027 | */ | |
2028 | if (size < 4096 || fls(size - 1) == fls(size-1 + REDZONE_ALIGN + | |
2029 | 2 * sizeof(unsigned long long))) | |
2030 | flags |= SLAB_RED_ZONE | SLAB_STORE_USER; | |
2031 | if (!(flags & SLAB_DESTROY_BY_RCU)) | |
2032 | flags |= SLAB_POISON; | |
2033 | #endif | |
2034 | #endif | |
2035 | ||
2036 | /* | |
2037 | * Check that size is in terms of words. This is needed to avoid | |
2038 | * unaligned accesses for some archs when redzoning is used, and makes | |
2039 | * sure any on-slab bufctl's are also correctly aligned. | |
2040 | */ | |
2041 | if (size & (BYTES_PER_WORD - 1)) { | |
2042 | size += (BYTES_PER_WORD - 1); | |
2043 | size &= ~(BYTES_PER_WORD - 1); | |
2044 | } | |
2045 | ||
2046 | if (flags & SLAB_RED_ZONE) { | |
2047 | ralign = REDZONE_ALIGN; | |
2048 | /* If redzoning, ensure that the second redzone is suitably | |
2049 | * aligned, by adjusting the object size accordingly. */ | |
2050 | size += REDZONE_ALIGN - 1; | |
2051 | size &= ~(REDZONE_ALIGN - 1); | |
2052 | } | |
2053 | ||
2054 | /* 3) caller mandated alignment */ | |
2055 | if (ralign < cachep->align) { | |
2056 | ralign = cachep->align; | |
2057 | } | |
2058 | /* disable debug if necessary */ | |
2059 | if (ralign > __alignof__(unsigned long long)) | |
2060 | flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); | |
2061 | /* | |
2062 | * 4) Store it. | |
2063 | */ | |
2064 | cachep->align = ralign; | |
2065 | cachep->colour_off = cache_line_size(); | |
2066 | /* Offset must be a multiple of the alignment. */ | |
2067 | if (cachep->colour_off < cachep->align) | |
2068 | cachep->colour_off = cachep->align; | |
2069 | ||
2070 | if (slab_is_available()) | |
2071 | gfp = GFP_KERNEL; | |
2072 | else | |
2073 | gfp = GFP_NOWAIT; | |
2074 | ||
2075 | #if DEBUG | |
2076 | ||
2077 | /* | |
2078 | * Both debugging options require word-alignment which is calculated | |
2079 | * into align above. | |
2080 | */ | |
2081 | if (flags & SLAB_RED_ZONE) { | |
2082 | /* add space for red zone words */ | |
2083 | cachep->obj_offset += sizeof(unsigned long long); | |
2084 | size += 2 * sizeof(unsigned long long); | |
2085 | } | |
2086 | if (flags & SLAB_STORE_USER) { | |
2087 | /* user store requires one word storage behind the end of | |
2088 | * the real object. But if the second red zone needs to be | |
2089 | * aligned to 64 bits, we must allow that much space. | |
2090 | */ | |
2091 | if (flags & SLAB_RED_ZONE) | |
2092 | size += REDZONE_ALIGN; | |
2093 | else | |
2094 | size += BYTES_PER_WORD; | |
2095 | } | |
2096 | #endif | |
2097 | ||
2098 | kasan_cache_create(cachep, &size, &flags); | |
2099 | ||
2100 | size = ALIGN(size, cachep->align); | |
2101 | /* | |
2102 | * We should restrict the number of objects in a slab to implement | |
2103 | * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition. | |
2104 | */ | |
2105 | if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE) | |
2106 | size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align); | |
2107 | ||
2108 | #if DEBUG | |
2109 | /* | |
2110 | * To activate debug pagealloc, off-slab management is necessary | |
2111 | * requirement. In early phase of initialization, small sized slab | |
2112 | * doesn't get initialized so it would not be possible. So, we need | |
2113 | * to check size >= 256. It guarantees that all necessary small | |
2114 | * sized slab is initialized in current slab initialization sequence. | |
2115 | */ | |
2116 | if (debug_pagealloc_enabled() && (flags & SLAB_POISON) && | |
2117 | size >= 256 && cachep->object_size > cache_line_size()) { | |
2118 | if (size < PAGE_SIZE || size % PAGE_SIZE == 0) { | |
2119 | size_t tmp_size = ALIGN(size, PAGE_SIZE); | |
2120 | ||
2121 | if (set_off_slab_cache(cachep, tmp_size, flags)) { | |
2122 | flags |= CFLGS_OFF_SLAB; | |
2123 | cachep->obj_offset += tmp_size - size; | |
2124 | size = tmp_size; | |
2125 | goto done; | |
2126 | } | |
2127 | } | |
2128 | } | |
2129 | #endif | |
2130 | ||
2131 | if (set_objfreelist_slab_cache(cachep, size, flags)) { | |
2132 | flags |= CFLGS_OBJFREELIST_SLAB; | |
2133 | goto done; | |
2134 | } | |
2135 | ||
2136 | if (set_off_slab_cache(cachep, size, flags)) { | |
2137 | flags |= CFLGS_OFF_SLAB; | |
2138 | goto done; | |
2139 | } | |
2140 | ||
2141 | if (set_on_slab_cache(cachep, size, flags)) | |
2142 | goto done; | |
2143 | ||
2144 | return -E2BIG; | |
2145 | ||
2146 | done: | |
2147 | cachep->freelist_size = cachep->num * sizeof(freelist_idx_t); | |
2148 | cachep->flags = flags; | |
2149 | cachep->allocflags = __GFP_COMP; | |
2150 | if (flags & SLAB_CACHE_DMA) | |
2151 | cachep->allocflags |= GFP_DMA; | |
2152 | cachep->size = size; | |
2153 | cachep->reciprocal_buffer_size = reciprocal_value(size); | |
2154 | ||
2155 | #if DEBUG | |
2156 | /* | |
2157 | * If we're going to use the generic kernel_map_pages() | |
2158 | * poisoning, then it's going to smash the contents of | |
2159 | * the redzone and userword anyhow, so switch them off. | |
2160 | */ | |
2161 | if (IS_ENABLED(CONFIG_PAGE_POISONING) && | |
2162 | (cachep->flags & SLAB_POISON) && | |
2163 | is_debug_pagealloc_cache(cachep)) | |
2164 | cachep->flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER); | |
2165 | #endif | |
2166 | ||
2167 | if (OFF_SLAB(cachep)) { | |
2168 | cachep->freelist_cache = | |
2169 | kmalloc_slab(cachep->freelist_size, 0u); | |
2170 | } | |
2171 | ||
2172 | err = setup_cpu_cache(cachep, gfp); | |
2173 | if (err) { | |
2174 | __kmem_cache_release(cachep); | |
2175 | return err; | |
2176 | } | |
2177 | ||
2178 | return 0; | |
2179 | } | |
2180 | ||
2181 | #if DEBUG | |
2182 | static void check_irq_off(void) | |
2183 | { | |
2184 | BUG_ON(!irqs_disabled()); | |
2185 | } | |
2186 | ||
2187 | static void check_irq_on(void) | |
2188 | { | |
2189 | BUG_ON(irqs_disabled()); | |
2190 | } | |
2191 | ||
2192 | static void check_mutex_acquired(void) | |
2193 | { | |
2194 | BUG_ON(!mutex_is_locked(&slab_mutex)); | |
2195 | } | |
2196 | ||
2197 | static void check_spinlock_acquired(struct kmem_cache *cachep) | |
2198 | { | |
2199 | #ifdef CONFIG_SMP | |
2200 | check_irq_off(); | |
2201 | assert_spin_locked(&get_node(cachep, numa_mem_id())->list_lock); | |
2202 | #endif | |
2203 | } | |
2204 | ||
2205 | static void check_spinlock_acquired_node(struct kmem_cache *cachep, int node) | |
2206 | { | |
2207 | #ifdef CONFIG_SMP | |
2208 | check_irq_off(); | |
2209 | assert_spin_locked(&get_node(cachep, node)->list_lock); | |
2210 | #endif | |
2211 | } | |
2212 | ||
2213 | #else | |
2214 | #define check_irq_off() do { } while(0) | |
2215 | #define check_irq_on() do { } while(0) | |
2216 | #define check_mutex_acquired() do { } while(0) | |
2217 | #define check_spinlock_acquired(x) do { } while(0) | |
2218 | #define check_spinlock_acquired_node(x, y) do { } while(0) | |
2219 | #endif | |
2220 | ||
2221 | static void drain_array_locked(struct kmem_cache *cachep, struct array_cache *ac, | |
2222 | int node, bool free_all, struct list_head *list) | |
2223 | { | |
2224 | int tofree; | |
2225 | ||
2226 | if (!ac || !ac->avail) | |
2227 | return; | |
2228 | ||
2229 | tofree = free_all ? ac->avail : (ac->limit + 4) / 5; | |
2230 | if (tofree > ac->avail) | |
2231 | tofree = (ac->avail + 1) / 2; | |
2232 | ||
2233 | free_block(cachep, ac->entry, tofree, node, list); | |
2234 | ac->avail -= tofree; | |
2235 | memmove(ac->entry, &(ac->entry[tofree]), sizeof(void *) * ac->avail); | |
2236 | } | |
2237 | ||
2238 | static void do_drain(void *arg) | |
2239 | { | |
2240 | struct kmem_cache *cachep = arg; | |
2241 | struct array_cache *ac; | |
2242 | int node = numa_mem_id(); | |
2243 | struct kmem_cache_node *n; | |
2244 | LIST_HEAD(list); | |
2245 | ||
2246 | check_irq_off(); | |
2247 | ac = cpu_cache_get(cachep); | |
2248 | n = get_node(cachep, node); | |
2249 | spin_lock(&n->list_lock); | |
2250 | free_block(cachep, ac->entry, ac->avail, node, &list); | |
2251 | spin_unlock(&n->list_lock); | |
2252 | slabs_destroy(cachep, &list); | |
2253 | ac->avail = 0; | |
2254 | } | |
2255 | ||
2256 | static void drain_cpu_caches(struct kmem_cache *cachep) | |
2257 | { | |
2258 | struct kmem_cache_node *n; | |
2259 | int node; | |
2260 | LIST_HEAD(list); | |
2261 | ||
2262 | on_each_cpu(do_drain, cachep, 1); | |
2263 | check_irq_on(); | |
2264 | for_each_kmem_cache_node(cachep, node, n) | |
2265 | if (n->alien) | |
2266 | drain_alien_cache(cachep, n->alien); | |
2267 | ||
2268 | for_each_kmem_cache_node(cachep, node, n) { | |
2269 | spin_lock_irq(&n->list_lock); | |
2270 | drain_array_locked(cachep, n->shared, node, true, &list); | |
2271 | spin_unlock_irq(&n->list_lock); | |
2272 | ||
2273 | slabs_destroy(cachep, &list); | |
2274 | } | |
2275 | } | |
2276 | ||
2277 | /* | |
2278 | * Remove slabs from the list of free slabs. | |
2279 | * Specify the number of slabs to drain in tofree. | |
2280 | * | |
2281 | * Returns the actual number of slabs released. | |
2282 | */ | |
2283 | static int drain_freelist(struct kmem_cache *cache, | |
2284 | struct kmem_cache_node *n, int tofree) | |
2285 | { | |
2286 | struct list_head *p; | |
2287 | int nr_freed; | |
2288 | struct page *page; | |
2289 | ||
2290 | nr_freed = 0; | |
2291 | while (nr_freed < tofree && !list_empty(&n->slabs_free)) { | |
2292 | ||
2293 | spin_lock_irq(&n->list_lock); | |
2294 | p = n->slabs_free.prev; | |
2295 | if (p == &n->slabs_free) { | |
2296 | spin_unlock_irq(&n->list_lock); | |
2297 | goto out; | |
2298 | } | |
2299 | ||
2300 | page = list_entry(p, struct page, lru); | |
2301 | list_del(&page->lru); | |
2302 | n->free_slabs--; | |
2303 | n->total_slabs--; | |
2304 | /* | |
2305 | * Safe to drop the lock. The slab is no longer linked | |
2306 | * to the cache. | |
2307 | */ | |
2308 | n->free_objects -= cache->num; | |
2309 | spin_unlock_irq(&n->list_lock); | |
2310 | slab_destroy(cache, page); | |
2311 | nr_freed++; | |
2312 | } | |
2313 | out: | |
2314 | return nr_freed; | |
2315 | } | |
2316 | ||
2317 | int __kmem_cache_shrink(struct kmem_cache *cachep) | |
2318 | { | |
2319 | int ret = 0; | |
2320 | int node; | |
2321 | struct kmem_cache_node *n; | |
2322 | ||
2323 | drain_cpu_caches(cachep); | |
2324 | ||
2325 | check_irq_on(); | |
2326 | for_each_kmem_cache_node(cachep, node, n) { | |
2327 | drain_freelist(cachep, n, INT_MAX); | |
2328 | ||
2329 | ret += !list_empty(&n->slabs_full) || | |
2330 | !list_empty(&n->slabs_partial); | |
2331 | } | |
2332 | return (ret ? 1 : 0); | |
2333 | } | |
2334 | ||
2335 | int __kmem_cache_shutdown(struct kmem_cache *cachep) | |
2336 | { | |
2337 | return __kmem_cache_shrink(cachep); | |
2338 | } | |
2339 | ||
2340 | void __kmem_cache_release(struct kmem_cache *cachep) | |
2341 | { | |
2342 | int i; | |
2343 | struct kmem_cache_node *n; | |
2344 | ||
2345 | cache_random_seq_destroy(cachep); | |
2346 | ||
2347 | free_percpu(cachep->cpu_cache); | |
2348 | ||
2349 | /* NUMA: free the node structures */ | |
2350 | for_each_kmem_cache_node(cachep, i, n) { | |
2351 | kfree(n->shared); | |
2352 | free_alien_cache(n->alien); | |
2353 | kfree(n); | |
2354 | cachep->node[i] = NULL; | |
2355 | } | |
2356 | } | |
2357 | ||
2358 | /* | |
2359 | * Get the memory for a slab management obj. | |
2360 | * | |
2361 | * For a slab cache when the slab descriptor is off-slab, the | |
2362 | * slab descriptor can't come from the same cache which is being created, | |
2363 | * Because if it is the case, that means we defer the creation of | |
2364 | * the kmalloc_{dma,}_cache of size sizeof(slab descriptor) to this point. | |
2365 | * And we eventually call down to __kmem_cache_create(), which | |
2366 | * in turn looks up in the kmalloc_{dma,}_caches for the disired-size one. | |
2367 | * This is a "chicken-and-egg" problem. | |
2368 | * | |
2369 | * So the off-slab slab descriptor shall come from the kmalloc_{dma,}_caches, | |
2370 | * which are all initialized during kmem_cache_init(). | |
2371 | */ | |
2372 | static void *alloc_slabmgmt(struct kmem_cache *cachep, | |
2373 | struct page *page, int colour_off, | |
2374 | gfp_t local_flags, int nodeid) | |
2375 | { | |
2376 | void *freelist; | |
2377 | void *addr = page_address(page); | |
2378 | ||
2379 | page->s_mem = addr + colour_off; | |
2380 | page->active = 0; | |
2381 | ||
2382 | if (OBJFREELIST_SLAB(cachep)) | |
2383 | freelist = NULL; | |
2384 | else if (OFF_SLAB(cachep)) { | |
2385 | /* Slab management obj is off-slab. */ | |
2386 | freelist = kmem_cache_alloc_node(cachep->freelist_cache, | |
2387 | local_flags, nodeid); | |
2388 | if (!freelist) | |
2389 | return NULL; | |
2390 | } else { | |
2391 | /* We will use last bytes at the slab for freelist */ | |
2392 | freelist = addr + (PAGE_SIZE << cachep->gfporder) - | |
2393 | cachep->freelist_size; | |
2394 | } | |
2395 | ||
2396 | return freelist; | |
2397 | } | |
2398 | ||
2399 | static inline freelist_idx_t get_free_obj(struct page *page, unsigned int idx) | |
2400 | { | |
2401 | return ((freelist_idx_t *)page->freelist)[idx]; | |
2402 | } | |
2403 | ||
2404 | static inline void set_free_obj(struct page *page, | |
2405 | unsigned int idx, freelist_idx_t val) | |
2406 | { | |
2407 | ((freelist_idx_t *)(page->freelist))[idx] = val; | |
2408 | } | |
2409 | ||
2410 | static void cache_init_objs_debug(struct kmem_cache *cachep, struct page *page) | |
2411 | { | |
2412 | #if DEBUG | |
2413 | int i; | |
2414 | ||
2415 | for (i = 0; i < cachep->num; i++) { | |
2416 | void *objp = index_to_obj(cachep, page, i); | |
2417 | ||
2418 | if (cachep->flags & SLAB_STORE_USER) | |
2419 | *dbg_userword(cachep, objp) = NULL; | |
2420 | ||
2421 | if (cachep->flags & SLAB_RED_ZONE) { | |
2422 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2423 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2424 | } | |
2425 | /* | |
2426 | * Constructors are not allowed to allocate memory from the same | |
2427 | * cache which they are a constructor for. Otherwise, deadlock. | |
2428 | * They must also be threaded. | |
2429 | */ | |
2430 | if (cachep->ctor && !(cachep->flags & SLAB_POISON)) { | |
2431 | kasan_unpoison_object_data(cachep, | |
2432 | objp + obj_offset(cachep)); | |
2433 | cachep->ctor(objp + obj_offset(cachep)); | |
2434 | kasan_poison_object_data( | |
2435 | cachep, objp + obj_offset(cachep)); | |
2436 | } | |
2437 | ||
2438 | if (cachep->flags & SLAB_RED_ZONE) { | |
2439 | if (*dbg_redzone2(cachep, objp) != RED_INACTIVE) | |
2440 | slab_error(cachep, "constructor overwrote the end of an object"); | |
2441 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE) | |
2442 | slab_error(cachep, "constructor overwrote the start of an object"); | |
2443 | } | |
2444 | /* need to poison the objs? */ | |
2445 | if (cachep->flags & SLAB_POISON) { | |
2446 | poison_obj(cachep, objp, POISON_FREE); | |
2447 | slab_kernel_map(cachep, objp, 0, 0); | |
2448 | } | |
2449 | } | |
2450 | #endif | |
2451 | } | |
2452 | ||
2453 | #ifdef CONFIG_SLAB_FREELIST_RANDOM | |
2454 | /* Hold information during a freelist initialization */ | |
2455 | union freelist_init_state { | |
2456 | struct { | |
2457 | unsigned int pos; | |
2458 | unsigned int *list; | |
2459 | unsigned int count; | |
2460 | }; | |
2461 | struct rnd_state rnd_state; | |
2462 | }; | |
2463 | ||
2464 | /* | |
2465 | * Initialize the state based on the randomization methode available. | |
2466 | * return true if the pre-computed list is available, false otherwize. | |
2467 | */ | |
2468 | static bool freelist_state_initialize(union freelist_init_state *state, | |
2469 | struct kmem_cache *cachep, | |
2470 | unsigned int count) | |
2471 | { | |
2472 | bool ret; | |
2473 | unsigned int rand; | |
2474 | ||
2475 | /* Use best entropy available to define a random shift */ | |
2476 | rand = get_random_int(); | |
2477 | ||
2478 | /* Use a random state if the pre-computed list is not available */ | |
2479 | if (!cachep->random_seq) { | |
2480 | prandom_seed_state(&state->rnd_state, rand); | |
2481 | ret = false; | |
2482 | } else { | |
2483 | state->list = cachep->random_seq; | |
2484 | state->count = count; | |
2485 | state->pos = rand % count; | |
2486 | ret = true; | |
2487 | } | |
2488 | return ret; | |
2489 | } | |
2490 | ||
2491 | /* Get the next entry on the list and randomize it using a random shift */ | |
2492 | static freelist_idx_t next_random_slot(union freelist_init_state *state) | |
2493 | { | |
2494 | if (state->pos >= state->count) | |
2495 | state->pos = 0; | |
2496 | return state->list[state->pos++]; | |
2497 | } | |
2498 | ||
2499 | /* Swap two freelist entries */ | |
2500 | static void swap_free_obj(struct page *page, unsigned int a, unsigned int b) | |
2501 | { | |
2502 | swap(((freelist_idx_t *)page->freelist)[a], | |
2503 | ((freelist_idx_t *)page->freelist)[b]); | |
2504 | } | |
2505 | ||
2506 | /* | |
2507 | * Shuffle the freelist initialization state based on pre-computed lists. | |
2508 | * return true if the list was successfully shuffled, false otherwise. | |
2509 | */ | |
2510 | static bool shuffle_freelist(struct kmem_cache *cachep, struct page *page) | |
2511 | { | |
2512 | unsigned int objfreelist = 0, i, rand, count = cachep->num; | |
2513 | union freelist_init_state state; | |
2514 | bool precomputed; | |
2515 | ||
2516 | if (count < 2) | |
2517 | return false; | |
2518 | ||
2519 | precomputed = freelist_state_initialize(&state, cachep, count); | |
2520 | ||
2521 | /* Take a random entry as the objfreelist */ | |
2522 | if (OBJFREELIST_SLAB(cachep)) { | |
2523 | if (!precomputed) | |
2524 | objfreelist = count - 1; | |
2525 | else | |
2526 | objfreelist = next_random_slot(&state); | |
2527 | page->freelist = index_to_obj(cachep, page, objfreelist) + | |
2528 | obj_offset(cachep); | |
2529 | count--; | |
2530 | } | |
2531 | ||
2532 | /* | |
2533 | * On early boot, generate the list dynamically. | |
2534 | * Later use a pre-computed list for speed. | |
2535 | */ | |
2536 | if (!precomputed) { | |
2537 | for (i = 0; i < count; i++) | |
2538 | set_free_obj(page, i, i); | |
2539 | ||
2540 | /* Fisher-Yates shuffle */ | |
2541 | for (i = count - 1; i > 0; i--) { | |
2542 | rand = prandom_u32_state(&state.rnd_state); | |
2543 | rand %= (i + 1); | |
2544 | swap_free_obj(page, i, rand); | |
2545 | } | |
2546 | } else { | |
2547 | for (i = 0; i < count; i++) | |
2548 | set_free_obj(page, i, next_random_slot(&state)); | |
2549 | } | |
2550 | ||
2551 | if (OBJFREELIST_SLAB(cachep)) | |
2552 | set_free_obj(page, cachep->num - 1, objfreelist); | |
2553 | ||
2554 | return true; | |
2555 | } | |
2556 | #else | |
2557 | static inline bool shuffle_freelist(struct kmem_cache *cachep, | |
2558 | struct page *page) | |
2559 | { | |
2560 | return false; | |
2561 | } | |
2562 | #endif /* CONFIG_SLAB_FREELIST_RANDOM */ | |
2563 | ||
2564 | static void cache_init_objs(struct kmem_cache *cachep, | |
2565 | struct page *page) | |
2566 | { | |
2567 | int i; | |
2568 | void *objp; | |
2569 | bool shuffled; | |
2570 | ||
2571 | cache_init_objs_debug(cachep, page); | |
2572 | ||
2573 | /* Try to randomize the freelist if enabled */ | |
2574 | shuffled = shuffle_freelist(cachep, page); | |
2575 | ||
2576 | if (!shuffled && OBJFREELIST_SLAB(cachep)) { | |
2577 | page->freelist = index_to_obj(cachep, page, cachep->num - 1) + | |
2578 | obj_offset(cachep); | |
2579 | } | |
2580 | ||
2581 | for (i = 0; i < cachep->num; i++) { | |
2582 | objp = index_to_obj(cachep, page, i); | |
2583 | kasan_init_slab_obj(cachep, objp); | |
2584 | ||
2585 | /* constructor could break poison info */ | |
2586 | if (DEBUG == 0 && cachep->ctor) { | |
2587 | kasan_unpoison_object_data(cachep, objp); | |
2588 | cachep->ctor(objp); | |
2589 | kasan_poison_object_data(cachep, objp); | |
2590 | } | |
2591 | ||
2592 | if (!shuffled) | |
2593 | set_free_obj(page, i, i); | |
2594 | } | |
2595 | } | |
2596 | ||
2597 | static void *slab_get_obj(struct kmem_cache *cachep, struct page *page) | |
2598 | { | |
2599 | void *objp; | |
2600 | ||
2601 | objp = index_to_obj(cachep, page, get_free_obj(page, page->active)); | |
2602 | page->active++; | |
2603 | ||
2604 | #if DEBUG | |
2605 | if (cachep->flags & SLAB_STORE_USER) | |
2606 | set_store_user_dirty(cachep); | |
2607 | #endif | |
2608 | ||
2609 | return objp; | |
2610 | } | |
2611 | ||
2612 | static void slab_put_obj(struct kmem_cache *cachep, | |
2613 | struct page *page, void *objp) | |
2614 | { | |
2615 | unsigned int objnr = obj_to_index(cachep, page, objp); | |
2616 | #if DEBUG | |
2617 | unsigned int i; | |
2618 | ||
2619 | /* Verify double free bug */ | |
2620 | for (i = page->active; i < cachep->num; i++) { | |
2621 | if (get_free_obj(page, i) == objnr) { | |
2622 | pr_err("slab: double free detected in cache '%s', objp %p\n", | |
2623 | cachep->name, objp); | |
2624 | BUG(); | |
2625 | } | |
2626 | } | |
2627 | #endif | |
2628 | page->active--; | |
2629 | if (!page->freelist) | |
2630 | page->freelist = objp + obj_offset(cachep); | |
2631 | ||
2632 | set_free_obj(page, page->active, objnr); | |
2633 | } | |
2634 | ||
2635 | /* | |
2636 | * Map pages beginning at addr to the given cache and slab. This is required | |
2637 | * for the slab allocator to be able to lookup the cache and slab of a | |
2638 | * virtual address for kfree, ksize, and slab debugging. | |
2639 | */ | |
2640 | static void slab_map_pages(struct kmem_cache *cache, struct page *page, | |
2641 | void *freelist) | |
2642 | { | |
2643 | page->slab_cache = cache; | |
2644 | page->freelist = freelist; | |
2645 | } | |
2646 | ||
2647 | /* | |
2648 | * Grow (by 1) the number of slabs within a cache. This is called by | |
2649 | * kmem_cache_alloc() when there are no active objs left in a cache. | |
2650 | */ | |
2651 | static struct page *cache_grow_begin(struct kmem_cache *cachep, | |
2652 | gfp_t flags, int nodeid) | |
2653 | { | |
2654 | void *freelist; | |
2655 | size_t offset; | |
2656 | gfp_t local_flags; | |
2657 | int page_node; | |
2658 | struct kmem_cache_node *n; | |
2659 | struct page *page; | |
2660 | ||
2661 | /* | |
2662 | * Be lazy and only check for valid flags here, keeping it out of the | |
2663 | * critical path in kmem_cache_alloc(). | |
2664 | */ | |
2665 | if (unlikely(flags & GFP_SLAB_BUG_MASK)) { | |
2666 | gfp_t invalid_mask = flags & GFP_SLAB_BUG_MASK; | |
2667 | flags &= ~GFP_SLAB_BUG_MASK; | |
2668 | pr_warn("Unexpected gfp: %#x (%pGg). Fixing up to gfp: %#x (%pGg). Fix your code!\n", | |
2669 | invalid_mask, &invalid_mask, flags, &flags); | |
2670 | dump_stack(); | |
2671 | } | |
2672 | local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK); | |
2673 | ||
2674 | check_irq_off(); | |
2675 | if (gfpflags_allow_blocking(local_flags)) | |
2676 | local_irq_enable(); | |
2677 | ||
2678 | /* | |
2679 | * Get mem for the objs. Attempt to allocate a physical page from | |
2680 | * 'nodeid'. | |
2681 | */ | |
2682 | page = kmem_getpages(cachep, local_flags, nodeid); | |
2683 | if (!page) | |
2684 | goto failed; | |
2685 | ||
2686 | page_node = page_to_nid(page); | |
2687 | n = get_node(cachep, page_node); | |
2688 | ||
2689 | /* Get colour for the slab, and cal the next value. */ | |
2690 | n->colour_next++; | |
2691 | if (n->colour_next >= cachep->colour) | |
2692 | n->colour_next = 0; | |
2693 | ||
2694 | offset = n->colour_next; | |
2695 | if (offset >= cachep->colour) | |
2696 | offset = 0; | |
2697 | ||
2698 | offset *= cachep->colour_off; | |
2699 | ||
2700 | /* Get slab management. */ | |
2701 | freelist = alloc_slabmgmt(cachep, page, offset, | |
2702 | local_flags & ~GFP_CONSTRAINT_MASK, page_node); | |
2703 | if (OFF_SLAB(cachep) && !freelist) | |
2704 | goto opps1; | |
2705 | ||
2706 | slab_map_pages(cachep, page, freelist); | |
2707 | ||
2708 | kasan_poison_slab(page); | |
2709 | cache_init_objs(cachep, page); | |
2710 | ||
2711 | if (gfpflags_allow_blocking(local_flags)) | |
2712 | local_irq_disable(); | |
2713 | ||
2714 | return page; | |
2715 | ||
2716 | opps1: | |
2717 | kmem_freepages(cachep, page); | |
2718 | failed: | |
2719 | if (gfpflags_allow_blocking(local_flags)) | |
2720 | local_irq_disable(); | |
2721 | return NULL; | |
2722 | } | |
2723 | ||
2724 | static void cache_grow_end(struct kmem_cache *cachep, struct page *page) | |
2725 | { | |
2726 | struct kmem_cache_node *n; | |
2727 | void *list = NULL; | |
2728 | ||
2729 | check_irq_off(); | |
2730 | ||
2731 | if (!page) | |
2732 | return; | |
2733 | ||
2734 | INIT_LIST_HEAD(&page->lru); | |
2735 | n = get_node(cachep, page_to_nid(page)); | |
2736 | ||
2737 | spin_lock(&n->list_lock); | |
2738 | n->total_slabs++; | |
2739 | if (!page->active) { | |
2740 | list_add_tail(&page->lru, &(n->slabs_free)); | |
2741 | n->free_slabs++; | |
2742 | } else | |
2743 | fixup_slab_list(cachep, n, page, &list); | |
2744 | ||
2745 | STATS_INC_GROWN(cachep); | |
2746 | n->free_objects += cachep->num - page->active; | |
2747 | spin_unlock(&n->list_lock); | |
2748 | ||
2749 | fixup_objfreelist_debug(cachep, &list); | |
2750 | } | |
2751 | ||
2752 | #if DEBUG | |
2753 | ||
2754 | /* | |
2755 | * Perform extra freeing checks: | |
2756 | * - detect bad pointers. | |
2757 | * - POISON/RED_ZONE checking | |
2758 | */ | |
2759 | static void kfree_debugcheck(const void *objp) | |
2760 | { | |
2761 | if (!virt_addr_valid(objp)) { | |
2762 | pr_err("kfree_debugcheck: out of range ptr %lxh\n", | |
2763 | (unsigned long)objp); | |
2764 | BUG(); | |
2765 | } | |
2766 | } | |
2767 | ||
2768 | static inline void verify_redzone_free(struct kmem_cache *cache, void *obj) | |
2769 | { | |
2770 | unsigned long long redzone1, redzone2; | |
2771 | ||
2772 | redzone1 = *dbg_redzone1(cache, obj); | |
2773 | redzone2 = *dbg_redzone2(cache, obj); | |
2774 | ||
2775 | /* | |
2776 | * Redzone is ok. | |
2777 | */ | |
2778 | if (redzone1 == RED_ACTIVE && redzone2 == RED_ACTIVE) | |
2779 | return; | |
2780 | ||
2781 | if (redzone1 == RED_INACTIVE && redzone2 == RED_INACTIVE) | |
2782 | slab_error(cache, "double free detected"); | |
2783 | else | |
2784 | slab_error(cache, "memory outside object was overwritten"); | |
2785 | ||
2786 | pr_err("%p: redzone 1:0x%llx, redzone 2:0x%llx\n", | |
2787 | obj, redzone1, redzone2); | |
2788 | } | |
2789 | ||
2790 | static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, | |
2791 | unsigned long caller) | |
2792 | { | |
2793 | unsigned int objnr; | |
2794 | struct page *page; | |
2795 | ||
2796 | BUG_ON(virt_to_cache(objp) != cachep); | |
2797 | ||
2798 | objp -= obj_offset(cachep); | |
2799 | kfree_debugcheck(objp); | |
2800 | page = virt_to_head_page(objp); | |
2801 | ||
2802 | if (cachep->flags & SLAB_RED_ZONE) { | |
2803 | verify_redzone_free(cachep, objp); | |
2804 | *dbg_redzone1(cachep, objp) = RED_INACTIVE; | |
2805 | *dbg_redzone2(cachep, objp) = RED_INACTIVE; | |
2806 | } | |
2807 | if (cachep->flags & SLAB_STORE_USER) { | |
2808 | set_store_user_dirty(cachep); | |
2809 | *dbg_userword(cachep, objp) = (void *)caller; | |
2810 | } | |
2811 | ||
2812 | objnr = obj_to_index(cachep, page, objp); | |
2813 | ||
2814 | BUG_ON(objnr >= cachep->num); | |
2815 | BUG_ON(objp != index_to_obj(cachep, page, objnr)); | |
2816 | ||
2817 | if (cachep->flags & SLAB_POISON) { | |
2818 | poison_obj(cachep, objp, POISON_FREE); | |
2819 | slab_kernel_map(cachep, objp, 0, caller); | |
2820 | } | |
2821 | return objp; | |
2822 | } | |
2823 | ||
2824 | #else | |
2825 | #define kfree_debugcheck(x) do { } while(0) | |
2826 | #define cache_free_debugcheck(x,objp,z) (objp) | |
2827 | #endif | |
2828 | ||
2829 | static inline void fixup_objfreelist_debug(struct kmem_cache *cachep, | |
2830 | void **list) | |
2831 | { | |
2832 | #if DEBUG | |
2833 | void *next = *list; | |
2834 | void *objp; | |
2835 | ||
2836 | while (next) { | |
2837 | objp = next - obj_offset(cachep); | |
2838 | next = *(void **)next; | |
2839 | poison_obj(cachep, objp, POISON_FREE); | |
2840 | } | |
2841 | #endif | |
2842 | } | |
2843 | ||
2844 | static inline void fixup_slab_list(struct kmem_cache *cachep, | |
2845 | struct kmem_cache_node *n, struct page *page, | |
2846 | void **list) | |
2847 | { | |
2848 | /* move slabp to correct slabp list: */ | |
2849 | list_del(&page->lru); | |
2850 | if (page->active == cachep->num) { | |
2851 | list_add(&page->lru, &n->slabs_full); | |
2852 | if (OBJFREELIST_SLAB(cachep)) { | |
2853 | #if DEBUG | |
2854 | /* Poisoning will be done without holding the lock */ | |
2855 | if (cachep->flags & SLAB_POISON) { | |
2856 | void **objp = page->freelist; | |
2857 | ||
2858 | *objp = *list; | |
2859 | *list = objp; | |
2860 | } | |
2861 | #endif | |
2862 | page->freelist = NULL; | |
2863 | } | |
2864 | } else | |
2865 | list_add(&page->lru, &n->slabs_partial); | |
2866 | } | |
2867 | ||
2868 | /* Try to find non-pfmemalloc slab if needed */ | |
2869 | static noinline struct page *get_valid_first_slab(struct kmem_cache_node *n, | |
2870 | struct page *page, bool pfmemalloc) | |
2871 | { | |
2872 | if (!page) | |
2873 | return NULL; | |
2874 | ||
2875 | if (pfmemalloc) | |
2876 | return page; | |
2877 | ||
2878 | if (!PageSlabPfmemalloc(page)) | |
2879 | return page; | |
2880 | ||
2881 | /* No need to keep pfmemalloc slab if we have enough free objects */ | |
2882 | if (n->free_objects > n->free_limit) { | |
2883 | ClearPageSlabPfmemalloc(page); | |
2884 | return page; | |
2885 | } | |
2886 | ||
2887 | /* Move pfmemalloc slab to the end of list to speed up next search */ | |
2888 | list_del(&page->lru); | |
2889 | if (!page->active) { | |
2890 | list_add_tail(&page->lru, &n->slabs_free); | |
2891 | n->free_slabs++; | |
2892 | } else | |
2893 | list_add_tail(&page->lru, &n->slabs_partial); | |
2894 | ||
2895 | list_for_each_entry(page, &n->slabs_partial, lru) { | |
2896 | if (!PageSlabPfmemalloc(page)) | |
2897 | return page; | |
2898 | } | |
2899 | ||
2900 | n->free_touched = 1; | |
2901 | list_for_each_entry(page, &n->slabs_free, lru) { | |
2902 | if (!PageSlabPfmemalloc(page)) { | |
2903 | n->free_slabs--; | |
2904 | return page; | |
2905 | } | |
2906 | } | |
2907 | ||
2908 | return NULL; | |
2909 | } | |
2910 | ||
2911 | static struct page *get_first_slab(struct kmem_cache_node *n, bool pfmemalloc) | |
2912 | { | |
2913 | struct page *page; | |
2914 | ||
2915 | assert_spin_locked(&n->list_lock); | |
2916 | page = list_first_entry_or_null(&n->slabs_partial, struct page, lru); | |
2917 | if (!page) { | |
2918 | n->free_touched = 1; | |
2919 | page = list_first_entry_or_null(&n->slabs_free, struct page, | |
2920 | lru); | |
2921 | if (page) | |
2922 | n->free_slabs--; | |
2923 | } | |
2924 | ||
2925 | if (sk_memalloc_socks()) | |
2926 | page = get_valid_first_slab(n, page, pfmemalloc); | |
2927 | ||
2928 | return page; | |
2929 | } | |
2930 | ||
2931 | static noinline void *cache_alloc_pfmemalloc(struct kmem_cache *cachep, | |
2932 | struct kmem_cache_node *n, gfp_t flags) | |
2933 | { | |
2934 | struct page *page; | |
2935 | void *obj; | |
2936 | void *list = NULL; | |
2937 | ||
2938 | if (!gfp_pfmemalloc_allowed(flags)) | |
2939 | return NULL; | |
2940 | ||
2941 | spin_lock(&n->list_lock); | |
2942 | page = get_first_slab(n, true); | |
2943 | if (!page) { | |
2944 | spin_unlock(&n->list_lock); | |
2945 | return NULL; | |
2946 | } | |
2947 | ||
2948 | obj = slab_get_obj(cachep, page); | |
2949 | n->free_objects--; | |
2950 | ||
2951 | fixup_slab_list(cachep, n, page, &list); | |
2952 | ||
2953 | spin_unlock(&n->list_lock); | |
2954 | fixup_objfreelist_debug(cachep, &list); | |
2955 | ||
2956 | return obj; | |
2957 | } | |
2958 | ||
2959 | /* | |
2960 | * Slab list should be fixed up by fixup_slab_list() for existing slab | |
2961 | * or cache_grow_end() for new slab | |
2962 | */ | |
2963 | static __always_inline int alloc_block(struct kmem_cache *cachep, | |
2964 | struct array_cache *ac, struct page *page, int batchcount) | |
2965 | { | |
2966 | /* | |
2967 | * There must be at least one object available for | |
2968 | * allocation. | |
2969 | */ | |
2970 | BUG_ON(page->active >= cachep->num); | |
2971 | ||
2972 | while (page->active < cachep->num && batchcount--) { | |
2973 | STATS_INC_ALLOCED(cachep); | |
2974 | STATS_INC_ACTIVE(cachep); | |
2975 | STATS_SET_HIGH(cachep); | |
2976 | ||
2977 | ac->entry[ac->avail++] = slab_get_obj(cachep, page); | |
2978 | } | |
2979 | ||
2980 | return batchcount; | |
2981 | } | |
2982 | ||
2983 | static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags) | |
2984 | { | |
2985 | int batchcount; | |
2986 | struct kmem_cache_node *n; | |
2987 | struct array_cache *ac, *shared; | |
2988 | int node; | |
2989 | void *list = NULL; | |
2990 | struct page *page; | |
2991 | ||
2992 | check_irq_off(); | |
2993 | node = numa_mem_id(); | |
2994 | ||
2995 | ac = cpu_cache_get(cachep); | |
2996 | batchcount = ac->batchcount; | |
2997 | if (!ac->touched && batchcount > BATCHREFILL_LIMIT) { | |
2998 | /* | |
2999 | * If there was little recent activity on this cache, then | |
3000 | * perform only a partial refill. Otherwise we could generate | |
3001 | * refill bouncing. | |
3002 | */ | |
3003 | batchcount = BATCHREFILL_LIMIT; | |
3004 | } | |
3005 | n = get_node(cachep, node); | |
3006 | ||
3007 | BUG_ON(ac->avail > 0 || !n); | |
3008 | shared = READ_ONCE(n->shared); | |
3009 | if (!n->free_objects && (!shared || !shared->avail)) | |
3010 | goto direct_grow; | |
3011 | ||
3012 | spin_lock(&n->list_lock); | |
3013 | shared = READ_ONCE(n->shared); | |
3014 | ||
3015 | /* See if we can refill from the shared array */ | |
3016 | if (shared && transfer_objects(ac, shared, batchcount)) { | |
3017 | shared->touched = 1; | |
3018 | goto alloc_done; | |
3019 | } | |
3020 | ||
3021 | while (batchcount > 0) { | |
3022 | /* Get slab alloc is to come from. */ | |
3023 | page = get_first_slab(n, false); | |
3024 | if (!page) | |
3025 | goto must_grow; | |
3026 | ||
3027 | check_spinlock_acquired(cachep); | |
3028 | ||
3029 | batchcount = alloc_block(cachep, ac, page, batchcount); | |
3030 | fixup_slab_list(cachep, n, page, &list); | |
3031 | } | |
3032 | ||
3033 | must_grow: | |
3034 | n->free_objects -= ac->avail; | |
3035 | alloc_done: | |
3036 | spin_unlock(&n->list_lock); | |
3037 | fixup_objfreelist_debug(cachep, &list); | |
3038 | ||
3039 | direct_grow: | |
3040 | if (unlikely(!ac->avail)) { | |
3041 | /* Check if we can use obj in pfmemalloc slab */ | |
3042 | if (sk_memalloc_socks()) { | |
3043 | void *obj = cache_alloc_pfmemalloc(cachep, n, flags); | |
3044 | ||
3045 | if (obj) | |
3046 | return obj; | |
3047 | } | |
3048 | ||
3049 | page = cache_grow_begin(cachep, gfp_exact_node(flags), node); | |
3050 | ||
3051 | /* | |
3052 | * cache_grow_begin() can reenable interrupts, | |
3053 | * then ac could change. | |
3054 | */ | |
3055 | ac = cpu_cache_get(cachep); | |
3056 | if (!ac->avail && page) | |
3057 | alloc_block(cachep, ac, page, batchcount); | |
3058 | cache_grow_end(cachep, page); | |
3059 | ||
3060 | if (!ac->avail) | |
3061 | return NULL; | |
3062 | } | |
3063 | ac->touched = 1; | |
3064 | ||
3065 | return ac->entry[--ac->avail]; | |
3066 | } | |
3067 | ||
3068 | static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, | |
3069 | gfp_t flags) | |
3070 | { | |
3071 | might_sleep_if(gfpflags_allow_blocking(flags)); | |
3072 | } | |
3073 | ||
3074 | #if DEBUG | |
3075 | static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, | |
3076 | gfp_t flags, void *objp, unsigned long caller) | |
3077 | { | |
3078 | if (!objp) | |
3079 | return objp; | |
3080 | if (cachep->flags & SLAB_POISON) { | |
3081 | check_poison_obj(cachep, objp); | |
3082 | slab_kernel_map(cachep, objp, 1, 0); | |
3083 | poison_obj(cachep, objp, POISON_INUSE); | |
3084 | } | |
3085 | if (cachep->flags & SLAB_STORE_USER) | |
3086 | *dbg_userword(cachep, objp) = (void *)caller; | |
3087 | ||
3088 | if (cachep->flags & SLAB_RED_ZONE) { | |
3089 | if (*dbg_redzone1(cachep, objp) != RED_INACTIVE || | |
3090 | *dbg_redzone2(cachep, objp) != RED_INACTIVE) { | |
3091 | slab_error(cachep, "double free, or memory outside object was overwritten"); | |
3092 | pr_err("%p: redzone 1:0x%llx, redzone 2:0x%llx\n", | |
3093 | objp, *dbg_redzone1(cachep, objp), | |
3094 | *dbg_redzone2(cachep, objp)); | |
3095 | } | |
3096 | *dbg_redzone1(cachep, objp) = RED_ACTIVE; | |
3097 | *dbg_redzone2(cachep, objp) = RED_ACTIVE; | |
3098 | } | |
3099 | ||
3100 | objp += obj_offset(cachep); | |
3101 | if (cachep->ctor && cachep->flags & SLAB_POISON) | |
3102 | cachep->ctor(objp); | |
3103 | if (ARCH_SLAB_MINALIGN && | |
3104 | ((unsigned long)objp & (ARCH_SLAB_MINALIGN-1))) { | |
3105 | pr_err("0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n", | |
3106 | objp, (int)ARCH_SLAB_MINALIGN); | |
3107 | } | |
3108 | return objp; | |
3109 | } | |
3110 | #else | |
3111 | #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) | |
3112 | #endif | |
3113 | ||
3114 | static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3115 | { | |
3116 | void *objp; | |
3117 | struct array_cache *ac; | |
3118 | ||
3119 | check_irq_off(); | |
3120 | ||
3121 | ac = cpu_cache_get(cachep); | |
3122 | if (likely(ac->avail)) { | |
3123 | ac->touched = 1; | |
3124 | objp = ac->entry[--ac->avail]; | |
3125 | ||
3126 | STATS_INC_ALLOCHIT(cachep); | |
3127 | goto out; | |
3128 | } | |
3129 | ||
3130 | STATS_INC_ALLOCMISS(cachep); | |
3131 | objp = cache_alloc_refill(cachep, flags); | |
3132 | /* | |
3133 | * the 'ac' may be updated by cache_alloc_refill(), | |
3134 | * and kmemleak_erase() requires its correct value. | |
3135 | */ | |
3136 | ac = cpu_cache_get(cachep); | |
3137 | ||
3138 | out: | |
3139 | /* | |
3140 | * To avoid a false negative, if an object that is in one of the | |
3141 | * per-CPU caches is leaked, we need to make sure kmemleak doesn't | |
3142 | * treat the array pointers as a reference to the object. | |
3143 | */ | |
3144 | if (objp) | |
3145 | kmemleak_erase(&ac->entry[ac->avail]); | |
3146 | return objp; | |
3147 | } | |
3148 | ||
3149 | #ifdef CONFIG_NUMA | |
3150 | /* | |
3151 | * Try allocating on another node if PFA_SPREAD_SLAB is a mempolicy is set. | |
3152 | * | |
3153 | * If we are in_interrupt, then process context, including cpusets and | |
3154 | * mempolicy, may not apply and should not be used for allocation policy. | |
3155 | */ | |
3156 | static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3157 | { | |
3158 | int nid_alloc, nid_here; | |
3159 | ||
3160 | if (in_interrupt() || (flags & __GFP_THISNODE)) | |
3161 | return NULL; | |
3162 | nid_alloc = nid_here = numa_mem_id(); | |
3163 | if (cpuset_do_slab_mem_spread() && (cachep->flags & SLAB_MEM_SPREAD)) | |
3164 | nid_alloc = cpuset_slab_spread_node(); | |
3165 | else if (current->mempolicy) | |
3166 | nid_alloc = mempolicy_slab_node(); | |
3167 | if (nid_alloc != nid_here) | |
3168 | return ____cache_alloc_node(cachep, flags, nid_alloc); | |
3169 | return NULL; | |
3170 | } | |
3171 | ||
3172 | /* | |
3173 | * Fallback function if there was no memory available and no objects on a | |
3174 | * certain node and fall back is permitted. First we scan all the | |
3175 | * available node for available objects. If that fails then we | |
3176 | * perform an allocation without specifying a node. This allows the page | |
3177 | * allocator to do its reclaim / fallback magic. We then insert the | |
3178 | * slab into the proper nodelist and then allocate from it. | |
3179 | */ | |
3180 | static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags) | |
3181 | { | |
3182 | struct zonelist *zonelist; | |
3183 | struct zoneref *z; | |
3184 | struct zone *zone; | |
3185 | enum zone_type high_zoneidx = gfp_zone(flags); | |
3186 | void *obj = NULL; | |
3187 | struct page *page; | |
3188 | int nid; | |
3189 | unsigned int cpuset_mems_cookie; | |
3190 | ||
3191 | if (flags & __GFP_THISNODE) | |
3192 | return NULL; | |
3193 | ||
3194 | retry_cpuset: | |
3195 | cpuset_mems_cookie = read_mems_allowed_begin(); | |
3196 | zonelist = node_zonelist(mempolicy_slab_node(), flags); | |
3197 | ||
3198 | retry: | |
3199 | /* | |
3200 | * Look through allowed nodes for objects available | |
3201 | * from existing per node queues. | |
3202 | */ | |
3203 | for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) { | |
3204 | nid = zone_to_nid(zone); | |
3205 | ||
3206 | if (cpuset_zone_allowed(zone, flags) && | |
3207 | get_node(cache, nid) && | |
3208 | get_node(cache, nid)->free_objects) { | |
3209 | obj = ____cache_alloc_node(cache, | |
3210 | gfp_exact_node(flags), nid); | |
3211 | if (obj) | |
3212 | break; | |
3213 | } | |
3214 | } | |
3215 | ||
3216 | if (!obj) { | |
3217 | /* | |
3218 | * This allocation will be performed within the constraints | |
3219 | * of the current cpuset / memory policy requirements. | |
3220 | * We may trigger various forms of reclaim on the allowed | |
3221 | * set and go into memory reserves if necessary. | |
3222 | */ | |
3223 | page = cache_grow_begin(cache, flags, numa_mem_id()); | |
3224 | cache_grow_end(cache, page); | |
3225 | if (page) { | |
3226 | nid = page_to_nid(page); | |
3227 | obj = ____cache_alloc_node(cache, | |
3228 | gfp_exact_node(flags), nid); | |
3229 | ||
3230 | /* | |
3231 | * Another processor may allocate the objects in | |
3232 | * the slab since we are not holding any locks. | |
3233 | */ | |
3234 | if (!obj) | |
3235 | goto retry; | |
3236 | } | |
3237 | } | |
3238 | ||
3239 | if (unlikely(!obj && read_mems_allowed_retry(cpuset_mems_cookie))) | |
3240 | goto retry_cpuset; | |
3241 | return obj; | |
3242 | } | |
3243 | ||
3244 | /* | |
3245 | * A interface to enable slab creation on nodeid | |
3246 | */ | |
3247 | static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, | |
3248 | int nodeid) | |
3249 | { | |
3250 | struct page *page; | |
3251 | struct kmem_cache_node *n; | |
3252 | void *obj = NULL; | |
3253 | void *list = NULL; | |
3254 | ||
3255 | VM_BUG_ON(nodeid < 0 || nodeid >= MAX_NUMNODES); | |
3256 | n = get_node(cachep, nodeid); | |
3257 | BUG_ON(!n); | |
3258 | ||
3259 | check_irq_off(); | |
3260 | spin_lock(&n->list_lock); | |
3261 | page = get_first_slab(n, false); | |
3262 | if (!page) | |
3263 | goto must_grow; | |
3264 | ||
3265 | check_spinlock_acquired_node(cachep, nodeid); | |
3266 | ||
3267 | STATS_INC_NODEALLOCS(cachep); | |
3268 | STATS_INC_ACTIVE(cachep); | |
3269 | STATS_SET_HIGH(cachep); | |
3270 | ||
3271 | BUG_ON(page->active == cachep->num); | |
3272 | ||
3273 | obj = slab_get_obj(cachep, page); | |
3274 | n->free_objects--; | |
3275 | ||
3276 | fixup_slab_list(cachep, n, page, &list); | |
3277 | ||
3278 | spin_unlock(&n->list_lock); | |
3279 | fixup_objfreelist_debug(cachep, &list); | |
3280 | return obj; | |
3281 | ||
3282 | must_grow: | |
3283 | spin_unlock(&n->list_lock); | |
3284 | page = cache_grow_begin(cachep, gfp_exact_node(flags), nodeid); | |
3285 | if (page) { | |
3286 | /* This slab isn't counted yet so don't update free_objects */ | |
3287 | obj = slab_get_obj(cachep, page); | |
3288 | } | |
3289 | cache_grow_end(cachep, page); | |
3290 | ||
3291 | return obj ? obj : fallback_alloc(cachep, flags); | |
3292 | } | |
3293 | ||
3294 | static __always_inline void * | |
3295 | slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, | |
3296 | unsigned long caller) | |
3297 | { | |
3298 | unsigned long save_flags; | |
3299 | void *ptr; | |
3300 | int slab_node = numa_mem_id(); | |
3301 | ||
3302 | flags &= gfp_allowed_mask; | |
3303 | cachep = slab_pre_alloc_hook(cachep, flags); | |
3304 | if (unlikely(!cachep)) | |
3305 | return NULL; | |
3306 | ||
3307 | cache_alloc_debugcheck_before(cachep, flags); | |
3308 | local_irq_save(save_flags); | |
3309 | ||
3310 | if (nodeid == NUMA_NO_NODE) | |
3311 | nodeid = slab_node; | |
3312 | ||
3313 | if (unlikely(!get_node(cachep, nodeid))) { | |
3314 | /* Node not bootstrapped yet */ | |
3315 | ptr = fallback_alloc(cachep, flags); | |
3316 | goto out; | |
3317 | } | |
3318 | ||
3319 | if (nodeid == slab_node) { | |
3320 | /* | |
3321 | * Use the locally cached objects if possible. | |
3322 | * However ____cache_alloc does not allow fallback | |
3323 | * to other nodes. It may fail while we still have | |
3324 | * objects on other nodes available. | |
3325 | */ | |
3326 | ptr = ____cache_alloc(cachep, flags); | |
3327 | if (ptr) | |
3328 | goto out; | |
3329 | } | |
3330 | /* ___cache_alloc_node can fall back to other nodes */ | |
3331 | ptr = ____cache_alloc_node(cachep, flags, nodeid); | |
3332 | out: | |
3333 | local_irq_restore(save_flags); | |
3334 | ptr = cache_alloc_debugcheck_after(cachep, flags, ptr, caller); | |
3335 | ||
3336 | if (unlikely(flags & __GFP_ZERO) && ptr) | |
3337 | memset(ptr, 0, cachep->object_size); | |
3338 | ||
3339 | slab_post_alloc_hook(cachep, flags, 1, &ptr); | |
3340 | return ptr; | |
3341 | } | |
3342 | ||
3343 | static __always_inline void * | |
3344 | __do_cache_alloc(struct kmem_cache *cache, gfp_t flags) | |
3345 | { | |
3346 | void *objp; | |
3347 | ||
3348 | if (current->mempolicy || cpuset_do_slab_mem_spread()) { | |
3349 | objp = alternate_node_alloc(cache, flags); | |
3350 | if (objp) | |
3351 | goto out; | |
3352 | } | |
3353 | objp = ____cache_alloc(cache, flags); | |
3354 | ||
3355 | /* | |
3356 | * We may just have run out of memory on the local node. | |
3357 | * ____cache_alloc_node() knows how to locate memory on other nodes | |
3358 | */ | |
3359 | if (!objp) | |
3360 | objp = ____cache_alloc_node(cache, flags, numa_mem_id()); | |
3361 | ||
3362 | out: | |
3363 | return objp; | |
3364 | } | |
3365 | #else | |
3366 | ||
3367 | static __always_inline void * | |
3368 | __do_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3369 | { | |
3370 | return ____cache_alloc(cachep, flags); | |
3371 | } | |
3372 | ||
3373 | #endif /* CONFIG_NUMA */ | |
3374 | ||
3375 | static __always_inline void * | |
3376 | slab_alloc(struct kmem_cache *cachep, gfp_t flags, unsigned long caller) | |
3377 | { | |
3378 | unsigned long save_flags; | |
3379 | void *objp; | |
3380 | ||
3381 | flags &= gfp_allowed_mask; | |
3382 | cachep = slab_pre_alloc_hook(cachep, flags); | |
3383 | if (unlikely(!cachep)) | |
3384 | return NULL; | |
3385 | ||
3386 | cache_alloc_debugcheck_before(cachep, flags); | |
3387 | local_irq_save(save_flags); | |
3388 | objp = __do_cache_alloc(cachep, flags); | |
3389 | local_irq_restore(save_flags); | |
3390 | objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller); | |
3391 | prefetchw(objp); | |
3392 | ||
3393 | if (unlikely(flags & __GFP_ZERO) && objp) | |
3394 | memset(objp, 0, cachep->object_size); | |
3395 | ||
3396 | slab_post_alloc_hook(cachep, flags, 1, &objp); | |
3397 | return objp; | |
3398 | } | |
3399 | ||
3400 | /* | |
3401 | * Caller needs to acquire correct kmem_cache_node's list_lock | |
3402 | * @list: List of detached free slabs should be freed by caller | |
3403 | */ | |
3404 | static void free_block(struct kmem_cache *cachep, void **objpp, | |
3405 | int nr_objects, int node, struct list_head *list) | |
3406 | { | |
3407 | int i; | |
3408 | struct kmem_cache_node *n = get_node(cachep, node); | |
3409 | struct page *page; | |
3410 | ||
3411 | n->free_objects += nr_objects; | |
3412 | ||
3413 | for (i = 0; i < nr_objects; i++) { | |
3414 | void *objp; | |
3415 | struct page *page; | |
3416 | ||
3417 | objp = objpp[i]; | |
3418 | ||
3419 | page = virt_to_head_page(objp); | |
3420 | list_del(&page->lru); | |
3421 | check_spinlock_acquired_node(cachep, node); | |
3422 | slab_put_obj(cachep, page, objp); | |
3423 | STATS_DEC_ACTIVE(cachep); | |
3424 | ||
3425 | /* fixup slab chains */ | |
3426 | if (page->active == 0) { | |
3427 | list_add(&page->lru, &n->slabs_free); | |
3428 | n->free_slabs++; | |
3429 | } else { | |
3430 | /* Unconditionally move a slab to the end of the | |
3431 | * partial list on free - maximum time for the | |
3432 | * other objects to be freed, too. | |
3433 | */ | |
3434 | list_add_tail(&page->lru, &n->slabs_partial); | |
3435 | } | |
3436 | } | |
3437 | ||
3438 | while (n->free_objects > n->free_limit && !list_empty(&n->slabs_free)) { | |
3439 | n->free_objects -= cachep->num; | |
3440 | ||
3441 | page = list_last_entry(&n->slabs_free, struct page, lru); | |
3442 | list_move(&page->lru, list); | |
3443 | n->free_slabs--; | |
3444 | n->total_slabs--; | |
3445 | } | |
3446 | } | |
3447 | ||
3448 | static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) | |
3449 | { | |
3450 | int batchcount; | |
3451 | struct kmem_cache_node *n; | |
3452 | int node = numa_mem_id(); | |
3453 | LIST_HEAD(list); | |
3454 | ||
3455 | batchcount = ac->batchcount; | |
3456 | ||
3457 | check_irq_off(); | |
3458 | n = get_node(cachep, node); | |
3459 | spin_lock(&n->list_lock); | |
3460 | if (n->shared) { | |
3461 | struct array_cache *shared_array = n->shared; | |
3462 | int max = shared_array->limit - shared_array->avail; | |
3463 | if (max) { | |
3464 | if (batchcount > max) | |
3465 | batchcount = max; | |
3466 | memcpy(&(shared_array->entry[shared_array->avail]), | |
3467 | ac->entry, sizeof(void *) * batchcount); | |
3468 | shared_array->avail += batchcount; | |
3469 | goto free_done; | |
3470 | } | |
3471 | } | |
3472 | ||
3473 | free_block(cachep, ac->entry, batchcount, node, &list); | |
3474 | free_done: | |
3475 | #if STATS | |
3476 | { | |
3477 | int i = 0; | |
3478 | struct page *page; | |
3479 | ||
3480 | list_for_each_entry(page, &n->slabs_free, lru) { | |
3481 | BUG_ON(page->active); | |
3482 | ||
3483 | i++; | |
3484 | } | |
3485 | STATS_SET_FREEABLE(cachep, i); | |
3486 | } | |
3487 | #endif | |
3488 | spin_unlock(&n->list_lock); | |
3489 | slabs_destroy(cachep, &list); | |
3490 | ac->avail -= batchcount; | |
3491 | memmove(ac->entry, &(ac->entry[batchcount]), sizeof(void *)*ac->avail); | |
3492 | } | |
3493 | ||
3494 | /* | |
3495 | * Release an obj back to its cache. If the obj has a constructed state, it must | |
3496 | * be in this state _before_ it is released. Called with disabled ints. | |
3497 | */ | |
3498 | static inline void __cache_free(struct kmem_cache *cachep, void *objp, | |
3499 | unsigned long caller) | |
3500 | { | |
3501 | /* Put the object into the quarantine, don't touch it for now. */ | |
3502 | if (kasan_slab_free(cachep, objp)) | |
3503 | return; | |
3504 | ||
3505 | ___cache_free(cachep, objp, caller); | |
3506 | } | |
3507 | ||
3508 | void ___cache_free(struct kmem_cache *cachep, void *objp, | |
3509 | unsigned long caller) | |
3510 | { | |
3511 | struct array_cache *ac = cpu_cache_get(cachep); | |
3512 | ||
3513 | check_irq_off(); | |
3514 | kmemleak_free_recursive(objp, cachep->flags); | |
3515 | objp = cache_free_debugcheck(cachep, objp, caller); | |
3516 | ||
3517 | kmemcheck_slab_free(cachep, objp, cachep->object_size); | |
3518 | ||
3519 | /* | |
3520 | * Skip calling cache_free_alien() when the platform is not numa. | |
3521 | * This will avoid cache misses that happen while accessing slabp (which | |
3522 | * is per page memory reference) to get nodeid. Instead use a global | |
3523 | * variable to skip the call, which is mostly likely to be present in | |
3524 | * the cache. | |
3525 | */ | |
3526 | if (nr_online_nodes > 1 && cache_free_alien(cachep, objp)) | |
3527 | return; | |
3528 | ||
3529 | if (ac->avail < ac->limit) { | |
3530 | STATS_INC_FREEHIT(cachep); | |
3531 | } else { | |
3532 | STATS_INC_FREEMISS(cachep); | |
3533 | cache_flusharray(cachep, ac); | |
3534 | } | |
3535 | ||
3536 | if (sk_memalloc_socks()) { | |
3537 | struct page *page = virt_to_head_page(objp); | |
3538 | ||
3539 | if (unlikely(PageSlabPfmemalloc(page))) { | |
3540 | cache_free_pfmemalloc(cachep, page, objp); | |
3541 | return; | |
3542 | } | |
3543 | } | |
3544 | ||
3545 | ac->entry[ac->avail++] = objp; | |
3546 | } | |
3547 | ||
3548 | /** | |
3549 | * kmem_cache_alloc - Allocate an object | |
3550 | * @cachep: The cache to allocate from. | |
3551 | * @flags: See kmalloc(). | |
3552 | * | |
3553 | * Allocate an object from this cache. The flags are only relevant | |
3554 | * if the cache has no available objects. | |
3555 | */ | |
3556 | void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) | |
3557 | { | |
3558 | void *ret = slab_alloc(cachep, flags, _RET_IP_); | |
3559 | ||
3560 | kasan_slab_alloc(cachep, ret, flags); | |
3561 | trace_kmem_cache_alloc(_RET_IP_, ret, | |
3562 | cachep->object_size, cachep->size, flags); | |
3563 | ||
3564 | return ret; | |
3565 | } | |
3566 | EXPORT_SYMBOL(kmem_cache_alloc); | |
3567 | ||
3568 | static __always_inline void | |
3569 | cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags, | |
3570 | size_t size, void **p, unsigned long caller) | |
3571 | { | |
3572 | size_t i; | |
3573 | ||
3574 | for (i = 0; i < size; i++) | |
3575 | p[i] = cache_alloc_debugcheck_after(s, flags, p[i], caller); | |
3576 | } | |
3577 | ||
3578 | int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size, | |
3579 | void **p) | |
3580 | { | |
3581 | size_t i; | |
3582 | ||
3583 | s = slab_pre_alloc_hook(s, flags); | |
3584 | if (!s) | |
3585 | return 0; | |
3586 | ||
3587 | cache_alloc_debugcheck_before(s, flags); | |
3588 | ||
3589 | local_irq_disable(); | |
3590 | for (i = 0; i < size; i++) { | |
3591 | void *objp = __do_cache_alloc(s, flags); | |
3592 | ||
3593 | if (unlikely(!objp)) | |
3594 | goto error; | |
3595 | p[i] = objp; | |
3596 | } | |
3597 | local_irq_enable(); | |
3598 | ||
3599 | cache_alloc_debugcheck_after_bulk(s, flags, size, p, _RET_IP_); | |
3600 | ||
3601 | /* Clear memory outside IRQ disabled section */ | |
3602 | if (unlikely(flags & __GFP_ZERO)) | |
3603 | for (i = 0; i < size; i++) | |
3604 | memset(p[i], 0, s->object_size); | |
3605 | ||
3606 | slab_post_alloc_hook(s, flags, size, p); | |
3607 | /* FIXME: Trace call missing. Christoph would like a bulk variant */ | |
3608 | return size; | |
3609 | error: | |
3610 | local_irq_enable(); | |
3611 | cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_); | |
3612 | slab_post_alloc_hook(s, flags, i, p); | |
3613 | __kmem_cache_free_bulk(s, i, p); | |
3614 | return 0; | |
3615 | } | |
3616 | EXPORT_SYMBOL(kmem_cache_alloc_bulk); | |
3617 | ||
3618 | #ifdef CONFIG_TRACING | |
3619 | void * | |
3620 | kmem_cache_alloc_trace(struct kmem_cache *cachep, gfp_t flags, size_t size) | |
3621 | { | |
3622 | void *ret; | |
3623 | ||
3624 | ret = slab_alloc(cachep, flags, _RET_IP_); | |
3625 | ||
3626 | kasan_kmalloc(cachep, ret, size, flags); | |
3627 | trace_kmalloc(_RET_IP_, ret, | |
3628 | size, cachep->size, flags); | |
3629 | return ret; | |
3630 | } | |
3631 | EXPORT_SYMBOL(kmem_cache_alloc_trace); | |
3632 | #endif | |
3633 | ||
3634 | #ifdef CONFIG_NUMA | |
3635 | /** | |
3636 | * kmem_cache_alloc_node - Allocate an object on the specified node | |
3637 | * @cachep: The cache to allocate from. | |
3638 | * @flags: See kmalloc(). | |
3639 | * @nodeid: node number of the target node. | |
3640 | * | |
3641 | * Identical to kmem_cache_alloc but it will allocate memory on the given | |
3642 | * node, which can improve the performance for cpu bound structures. | |
3643 | * | |
3644 | * Fallback to other node is possible if __GFP_THISNODE is not set. | |
3645 | */ | |
3646 | void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid) | |
3647 | { | |
3648 | void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); | |
3649 | ||
3650 | kasan_slab_alloc(cachep, ret, flags); | |
3651 | trace_kmem_cache_alloc_node(_RET_IP_, ret, | |
3652 | cachep->object_size, cachep->size, | |
3653 | flags, nodeid); | |
3654 | ||
3655 | return ret; | |
3656 | } | |
3657 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
3658 | ||
3659 | #ifdef CONFIG_TRACING | |
3660 | void *kmem_cache_alloc_node_trace(struct kmem_cache *cachep, | |
3661 | gfp_t flags, | |
3662 | int nodeid, | |
3663 | size_t size) | |
3664 | { | |
3665 | void *ret; | |
3666 | ||
3667 | ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_); | |
3668 | ||
3669 | kasan_kmalloc(cachep, ret, size, flags); | |
3670 | trace_kmalloc_node(_RET_IP_, ret, | |
3671 | size, cachep->size, | |
3672 | flags, nodeid); | |
3673 | return ret; | |
3674 | } | |
3675 | EXPORT_SYMBOL(kmem_cache_alloc_node_trace); | |
3676 | #endif | |
3677 | ||
3678 | static __always_inline void * | |
3679 | __do_kmalloc_node(size_t size, gfp_t flags, int node, unsigned long caller) | |
3680 | { | |
3681 | struct kmem_cache *cachep; | |
3682 | void *ret; | |
3683 | ||
3684 | cachep = kmalloc_slab(size, flags); | |
3685 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) | |
3686 | return cachep; | |
3687 | ret = kmem_cache_alloc_node_trace(cachep, flags, node, size); | |
3688 | kasan_kmalloc(cachep, ret, size, flags); | |
3689 | ||
3690 | return ret; | |
3691 | } | |
3692 | ||
3693 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
3694 | { | |
3695 | return __do_kmalloc_node(size, flags, node, _RET_IP_); | |
3696 | } | |
3697 | EXPORT_SYMBOL(__kmalloc_node); | |
3698 | ||
3699 | void *__kmalloc_node_track_caller(size_t size, gfp_t flags, | |
3700 | int node, unsigned long caller) | |
3701 | { | |
3702 | return __do_kmalloc_node(size, flags, node, caller); | |
3703 | } | |
3704 | EXPORT_SYMBOL(__kmalloc_node_track_caller); | |
3705 | #endif /* CONFIG_NUMA */ | |
3706 | ||
3707 | /** | |
3708 | * __do_kmalloc - allocate memory | |
3709 | * @size: how many bytes of memory are required. | |
3710 | * @flags: the type of memory to allocate (see kmalloc). | |
3711 | * @caller: function caller for debug tracking of the caller | |
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 | cachep = kmalloc_slab(size, flags); | |
3720 | if (unlikely(ZERO_OR_NULL_PTR(cachep))) | |
3721 | return cachep; | |
3722 | ret = slab_alloc(cachep, flags, caller); | |
3723 | ||
3724 | kasan_kmalloc(cachep, ret, size, flags); | |
3725 | trace_kmalloc(caller, ret, | |
3726 | size, cachep->size, flags); | |
3727 | ||
3728 | return ret; | |
3729 | } | |
3730 | ||
3731 | void *__kmalloc(size_t size, gfp_t flags) | |
3732 | { | |
3733 | return __do_kmalloc(size, flags, _RET_IP_); | |
3734 | } | |
3735 | EXPORT_SYMBOL(__kmalloc); | |
3736 | ||
3737 | void *__kmalloc_track_caller(size_t size, gfp_t flags, unsigned long caller) | |
3738 | { | |
3739 | return __do_kmalloc(size, flags, caller); | |
3740 | } | |
3741 | EXPORT_SYMBOL(__kmalloc_track_caller); | |
3742 | ||
3743 | /** | |
3744 | * kmem_cache_free - Deallocate an object | |
3745 | * @cachep: The cache the allocation was from. | |
3746 | * @objp: The previously allocated object. | |
3747 | * | |
3748 | * Free an object which was previously allocated from this | |
3749 | * cache. | |
3750 | */ | |
3751 | void kmem_cache_free(struct kmem_cache *cachep, void *objp) | |
3752 | { | |
3753 | unsigned long flags; | |
3754 | cachep = cache_from_obj(cachep, objp); | |
3755 | if (!cachep) | |
3756 | return; | |
3757 | ||
3758 | local_irq_save(flags); | |
3759 | debug_check_no_locks_freed(objp, cachep->object_size); | |
3760 | if (!(cachep->flags & SLAB_DEBUG_OBJECTS)) | |
3761 | debug_check_no_obj_freed(objp, cachep->object_size); | |
3762 | __cache_free(cachep, objp, _RET_IP_); | |
3763 | local_irq_restore(flags); | |
3764 | ||
3765 | trace_kmem_cache_free(_RET_IP_, objp); | |
3766 | } | |
3767 | EXPORT_SYMBOL(kmem_cache_free); | |
3768 | ||
3769 | void kmem_cache_free_bulk(struct kmem_cache *orig_s, size_t size, void **p) | |
3770 | { | |
3771 | struct kmem_cache *s; | |
3772 | size_t i; | |
3773 | ||
3774 | local_irq_disable(); | |
3775 | for (i = 0; i < size; i++) { | |
3776 | void *objp = p[i]; | |
3777 | ||
3778 | if (!orig_s) /* called via kfree_bulk */ | |
3779 | s = virt_to_cache(objp); | |
3780 | else | |
3781 | s = cache_from_obj(orig_s, objp); | |
3782 | ||
3783 | debug_check_no_locks_freed(objp, s->object_size); | |
3784 | if (!(s->flags & SLAB_DEBUG_OBJECTS)) | |
3785 | debug_check_no_obj_freed(objp, s->object_size); | |
3786 | ||
3787 | __cache_free(s, objp, _RET_IP_); | |
3788 | } | |
3789 | local_irq_enable(); | |
3790 | ||
3791 | /* FIXME: add tracing */ | |
3792 | } | |
3793 | EXPORT_SYMBOL(kmem_cache_free_bulk); | |
3794 | ||
3795 | /** | |
3796 | * kfree - free previously allocated memory | |
3797 | * @objp: pointer returned by kmalloc. | |
3798 | * | |
3799 | * If @objp is NULL, no operation is performed. | |
3800 | * | |
3801 | * Don't free memory not originally allocated by kmalloc() | |
3802 | * or you will run into trouble. | |
3803 | */ | |
3804 | void kfree(const void *objp) | |
3805 | { | |
3806 | struct kmem_cache *c; | |
3807 | unsigned long flags; | |
3808 | ||
3809 | trace_kfree(_RET_IP_, objp); | |
3810 | ||
3811 | if (unlikely(ZERO_OR_NULL_PTR(objp))) | |
3812 | return; | |
3813 | local_irq_save(flags); | |
3814 | kfree_debugcheck(objp); | |
3815 | c = virt_to_cache(objp); | |
3816 | debug_check_no_locks_freed(objp, c->object_size); | |
3817 | ||
3818 | debug_check_no_obj_freed(objp, c->object_size); | |
3819 | __cache_free(c, (void *)objp, _RET_IP_); | |
3820 | local_irq_restore(flags); | |
3821 | } | |
3822 | EXPORT_SYMBOL(kfree); | |
3823 | ||
3824 | /* | |
3825 | * This initializes kmem_cache_node or resizes various caches for all nodes. | |
3826 | */ | |
3827 | static int setup_kmem_cache_nodes(struct kmem_cache *cachep, gfp_t gfp) | |
3828 | { | |
3829 | int ret; | |
3830 | int node; | |
3831 | struct kmem_cache_node *n; | |
3832 | ||
3833 | for_each_online_node(node) { | |
3834 | ret = setup_kmem_cache_node(cachep, node, gfp, true); | |
3835 | if (ret) | |
3836 | goto fail; | |
3837 | ||
3838 | } | |
3839 | ||
3840 | return 0; | |
3841 | ||
3842 | fail: | |
3843 | if (!cachep->list.next) { | |
3844 | /* Cache is not active yet. Roll back what we did */ | |
3845 | node--; | |
3846 | while (node >= 0) { | |
3847 | n = get_node(cachep, node); | |
3848 | if (n) { | |
3849 | kfree(n->shared); | |
3850 | free_alien_cache(n->alien); | |
3851 | kfree(n); | |
3852 | cachep->node[node] = NULL; | |
3853 | } | |
3854 | node--; | |
3855 | } | |
3856 | } | |
3857 | return -ENOMEM; | |
3858 | } | |
3859 | ||
3860 | /* Always called with the slab_mutex held */ | |
3861 | static int __do_tune_cpucache(struct kmem_cache *cachep, int limit, | |
3862 | int batchcount, int shared, gfp_t gfp) | |
3863 | { | |
3864 | struct array_cache __percpu *cpu_cache, *prev; | |
3865 | int cpu; | |
3866 | ||
3867 | cpu_cache = alloc_kmem_cache_cpus(cachep, limit, batchcount); | |
3868 | if (!cpu_cache) | |
3869 | return -ENOMEM; | |
3870 | ||
3871 | prev = cachep->cpu_cache; | |
3872 | cachep->cpu_cache = cpu_cache; | |
3873 | kick_all_cpus_sync(); | |
3874 | ||
3875 | check_irq_on(); | |
3876 | cachep->batchcount = batchcount; | |
3877 | cachep->limit = limit; | |
3878 | cachep->shared = shared; | |
3879 | ||
3880 | if (!prev) | |
3881 | goto setup_node; | |
3882 | ||
3883 | for_each_online_cpu(cpu) { | |
3884 | LIST_HEAD(list); | |
3885 | int node; | |
3886 | struct kmem_cache_node *n; | |
3887 | struct array_cache *ac = per_cpu_ptr(prev, cpu); | |
3888 | ||
3889 | node = cpu_to_mem(cpu); | |
3890 | n = get_node(cachep, node); | |
3891 | spin_lock_irq(&n->list_lock); | |
3892 | free_block(cachep, ac->entry, ac->avail, node, &list); | |
3893 | spin_unlock_irq(&n->list_lock); | |
3894 | slabs_destroy(cachep, &list); | |
3895 | } | |
3896 | free_percpu(prev); | |
3897 | ||
3898 | setup_node: | |
3899 | return setup_kmem_cache_nodes(cachep, gfp); | |
3900 | } | |
3901 | ||
3902 | static int do_tune_cpucache(struct kmem_cache *cachep, int limit, | |
3903 | int batchcount, int shared, gfp_t gfp) | |
3904 | { | |
3905 | int ret; | |
3906 | struct kmem_cache *c; | |
3907 | ||
3908 | ret = __do_tune_cpucache(cachep, limit, batchcount, shared, gfp); | |
3909 | ||
3910 | if (slab_state < FULL) | |
3911 | return ret; | |
3912 | ||
3913 | if ((ret < 0) || !is_root_cache(cachep)) | |
3914 | return ret; | |
3915 | ||
3916 | lockdep_assert_held(&slab_mutex); | |
3917 | for_each_memcg_cache(c, cachep) { | |
3918 | /* return value determined by the root cache only */ | |
3919 | __do_tune_cpucache(c, limit, batchcount, shared, gfp); | |
3920 | } | |
3921 | ||
3922 | return ret; | |
3923 | } | |
3924 | ||
3925 | /* Called with slab_mutex held always */ | |
3926 | static int enable_cpucache(struct kmem_cache *cachep, gfp_t gfp) | |
3927 | { | |
3928 | int err; | |
3929 | int limit = 0; | |
3930 | int shared = 0; | |
3931 | int batchcount = 0; | |
3932 | ||
3933 | err = cache_random_seq_create(cachep, cachep->num, gfp); | |
3934 | if (err) | |
3935 | goto end; | |
3936 | ||
3937 | if (!is_root_cache(cachep)) { | |
3938 | struct kmem_cache *root = memcg_root_cache(cachep); | |
3939 | limit = root->limit; | |
3940 | shared = root->shared; | |
3941 | batchcount = root->batchcount; | |
3942 | } | |
3943 | ||
3944 | if (limit && shared && batchcount) | |
3945 | goto skip_setup; | |
3946 | /* | |
3947 | * The head array serves three purposes: | |
3948 | * - create a LIFO ordering, i.e. return objects that are cache-warm | |
3949 | * - reduce the number of spinlock operations. | |
3950 | * - reduce the number of linked list operations on the slab and | |
3951 | * bufctl chains: array operations are cheaper. | |
3952 | * The numbers are guessed, we should auto-tune as described by | |
3953 | * Bonwick. | |
3954 | */ | |
3955 | if (cachep->size > 131072) | |
3956 | limit = 1; | |
3957 | else if (cachep->size > PAGE_SIZE) | |
3958 | limit = 8; | |
3959 | else if (cachep->size > 1024) | |
3960 | limit = 24; | |
3961 | else if (cachep->size > 256) | |
3962 | limit = 54; | |
3963 | else | |
3964 | limit = 120; | |
3965 | ||
3966 | /* | |
3967 | * CPU bound tasks (e.g. network routing) can exhibit cpu bound | |
3968 | * allocation behaviour: Most allocs on one cpu, most free operations | |
3969 | * on another cpu. For these cases, an efficient object passing between | |
3970 | * cpus is necessary. This is provided by a shared array. The array | |
3971 | * replaces Bonwick's magazine layer. | |
3972 | * On uniprocessor, it's functionally equivalent (but less efficient) | |
3973 | * to a larger limit. Thus disabled by default. | |
3974 | */ | |
3975 | shared = 0; | |
3976 | if (cachep->size <= PAGE_SIZE && num_possible_cpus() > 1) | |
3977 | shared = 8; | |
3978 | ||
3979 | #if DEBUG | |
3980 | /* | |
3981 | * With debugging enabled, large batchcount lead to excessively long | |
3982 | * periods with disabled local interrupts. Limit the batchcount | |
3983 | */ | |
3984 | if (limit > 32) | |
3985 | limit = 32; | |
3986 | #endif | |
3987 | batchcount = (limit + 1) / 2; | |
3988 | skip_setup: | |
3989 | err = do_tune_cpucache(cachep, limit, batchcount, shared, gfp); | |
3990 | end: | |
3991 | if (err) | |
3992 | pr_err("enable_cpucache failed for %s, error %d\n", | |
3993 | cachep->name, -err); | |
3994 | return err; | |
3995 | } | |
3996 | ||
3997 | /* | |
3998 | * Drain an array if it contains any elements taking the node lock only if | |
3999 | * necessary. Note that the node listlock also protects the array_cache | |
4000 | * if drain_array() is used on the shared array. | |
4001 | */ | |
4002 | static void drain_array(struct kmem_cache *cachep, struct kmem_cache_node *n, | |
4003 | struct array_cache *ac, int node) | |
4004 | { | |
4005 | LIST_HEAD(list); | |
4006 | ||
4007 | /* ac from n->shared can be freed if we don't hold the slab_mutex. */ | |
4008 | check_mutex_acquired(); | |
4009 | ||
4010 | if (!ac || !ac->avail) | |
4011 | return; | |
4012 | ||
4013 | if (ac->touched) { | |
4014 | ac->touched = 0; | |
4015 | return; | |
4016 | } | |
4017 | ||
4018 | spin_lock_irq(&n->list_lock); | |
4019 | drain_array_locked(cachep, ac, node, false, &list); | |
4020 | spin_unlock_irq(&n->list_lock); | |
4021 | ||
4022 | slabs_destroy(cachep, &list); | |
4023 | } | |
4024 | ||
4025 | /** | |
4026 | * cache_reap - Reclaim memory from caches. | |
4027 | * @w: work descriptor | |
4028 | * | |
4029 | * Called from workqueue/eventd every few seconds. | |
4030 | * Purpose: | |
4031 | * - clear the per-cpu caches for this CPU. | |
4032 | * - return freeable pages to the main free memory pool. | |
4033 | * | |
4034 | * If we cannot acquire the cache chain mutex then just give up - we'll try | |
4035 | * again on the next iteration. | |
4036 | */ | |
4037 | static void cache_reap(struct work_struct *w) | |
4038 | { | |
4039 | struct kmem_cache *searchp; | |
4040 | struct kmem_cache_node *n; | |
4041 | int node = numa_mem_id(); | |
4042 | struct delayed_work *work = to_delayed_work(w); | |
4043 | ||
4044 | if (!mutex_trylock(&slab_mutex)) | |
4045 | /* Give up. Setup the next iteration. */ | |
4046 | goto out; | |
4047 | ||
4048 | list_for_each_entry(searchp, &slab_caches, list) { | |
4049 | check_irq_on(); | |
4050 | ||
4051 | /* | |
4052 | * We only take the node lock if absolutely necessary and we | |
4053 | * have established with reasonable certainty that | |
4054 | * we can do some work if the lock was obtained. | |
4055 | */ | |
4056 | n = get_node(searchp, node); | |
4057 | ||
4058 | reap_alien(searchp, n); | |
4059 | ||
4060 | drain_array(searchp, n, cpu_cache_get(searchp), node); | |
4061 | ||
4062 | /* | |
4063 | * These are racy checks but it does not matter | |
4064 | * if we skip one check or scan twice. | |
4065 | */ | |
4066 | if (time_after(n->next_reap, jiffies)) | |
4067 | goto next; | |
4068 | ||
4069 | n->next_reap = jiffies + REAPTIMEOUT_NODE; | |
4070 | ||
4071 | drain_array(searchp, n, n->shared, node); | |
4072 | ||
4073 | if (n->free_touched) | |
4074 | n->free_touched = 0; | |
4075 | else { | |
4076 | int freed; | |
4077 | ||
4078 | freed = drain_freelist(searchp, n, (n->free_limit + | |
4079 | 5 * searchp->num - 1) / (5 * searchp->num)); | |
4080 | STATS_ADD_REAPED(searchp, freed); | |
4081 | } | |
4082 | next: | |
4083 | cond_resched(); | |
4084 | } | |
4085 | check_irq_on(); | |
4086 | mutex_unlock(&slab_mutex); | |
4087 | next_reap_node(); | |
4088 | out: | |
4089 | /* Set up the next iteration */ | |
4090 | schedule_delayed_work(work, round_jiffies_relative(REAPTIMEOUT_AC)); | |
4091 | } | |
4092 | ||
4093 | #ifdef CONFIG_SLABINFO | |
4094 | void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo) | |
4095 | { | |
4096 | unsigned long active_objs, num_objs, active_slabs; | |
4097 | unsigned long total_slabs = 0, free_objs = 0, shared_avail = 0; | |
4098 | unsigned long free_slabs = 0; | |
4099 | int node; | |
4100 | struct kmem_cache_node *n; | |
4101 | ||
4102 | for_each_kmem_cache_node(cachep, node, n) { | |
4103 | check_irq_on(); | |
4104 | spin_lock_irq(&n->list_lock); | |
4105 | ||
4106 | total_slabs += n->total_slabs; | |
4107 | free_slabs += n->free_slabs; | |
4108 | free_objs += n->free_objects; | |
4109 | ||
4110 | if (n->shared) | |
4111 | shared_avail += n->shared->avail; | |
4112 | ||
4113 | spin_unlock_irq(&n->list_lock); | |
4114 | } | |
4115 | num_objs = total_slabs * cachep->num; | |
4116 | active_slabs = total_slabs - free_slabs; | |
4117 | active_objs = num_objs - free_objs; | |
4118 | ||
4119 | sinfo->active_objs = active_objs; | |
4120 | sinfo->num_objs = num_objs; | |
4121 | sinfo->active_slabs = active_slabs; | |
4122 | sinfo->num_slabs = total_slabs; | |
4123 | sinfo->shared_avail = shared_avail; | |
4124 | sinfo->limit = cachep->limit; | |
4125 | sinfo->batchcount = cachep->batchcount; | |
4126 | sinfo->shared = cachep->shared; | |
4127 | sinfo->objects_per_slab = cachep->num; | |
4128 | sinfo->cache_order = cachep->gfporder; | |
4129 | } | |
4130 | ||
4131 | void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *cachep) | |
4132 | { | |
4133 | #if STATS | |
4134 | { /* node stats */ | |
4135 | unsigned long high = cachep->high_mark; | |
4136 | unsigned long allocs = cachep->num_allocations; | |
4137 | unsigned long grown = cachep->grown; | |
4138 | unsigned long reaped = cachep->reaped; | |
4139 | unsigned long errors = cachep->errors; | |
4140 | unsigned long max_freeable = cachep->max_freeable; | |
4141 | unsigned long node_allocs = cachep->node_allocs; | |
4142 | unsigned long node_frees = cachep->node_frees; | |
4143 | unsigned long overflows = cachep->node_overflow; | |
4144 | ||
4145 | seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu", | |
4146 | allocs, high, grown, | |
4147 | reaped, errors, max_freeable, node_allocs, | |
4148 | node_frees, overflows); | |
4149 | } | |
4150 | /* cpu stats */ | |
4151 | { | |
4152 | unsigned long allochit = atomic_read(&cachep->allochit); | |
4153 | unsigned long allocmiss = atomic_read(&cachep->allocmiss); | |
4154 | unsigned long freehit = atomic_read(&cachep->freehit); | |
4155 | unsigned long freemiss = atomic_read(&cachep->freemiss); | |
4156 | ||
4157 | seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", | |
4158 | allochit, allocmiss, freehit, freemiss); | |
4159 | } | |
4160 | #endif | |
4161 | } | |
4162 | ||
4163 | #define MAX_SLABINFO_WRITE 128 | |
4164 | /** | |
4165 | * slabinfo_write - Tuning for the slab allocator | |
4166 | * @file: unused | |
4167 | * @buffer: user buffer | |
4168 | * @count: data length | |
4169 | * @ppos: unused | |
4170 | */ | |
4171 | ssize_t slabinfo_write(struct file *file, const char __user *buffer, | |
4172 | size_t count, loff_t *ppos) | |
4173 | { | |
4174 | char kbuf[MAX_SLABINFO_WRITE + 1], *tmp; | |
4175 | int limit, batchcount, shared, res; | |
4176 | struct kmem_cache *cachep; | |
4177 | ||
4178 | if (count > MAX_SLABINFO_WRITE) | |
4179 | return -EINVAL; | |
4180 | if (copy_from_user(&kbuf, buffer, count)) | |
4181 | return -EFAULT; | |
4182 | kbuf[MAX_SLABINFO_WRITE] = '\0'; | |
4183 | ||
4184 | tmp = strchr(kbuf, ' '); | |
4185 | if (!tmp) | |
4186 | return -EINVAL; | |
4187 | *tmp = '\0'; | |
4188 | tmp++; | |
4189 | if (sscanf(tmp, " %d %d %d", &limit, &batchcount, &shared) != 3) | |
4190 | return -EINVAL; | |
4191 | ||
4192 | /* Find the cache in the chain of caches. */ | |
4193 | mutex_lock(&slab_mutex); | |
4194 | res = -EINVAL; | |
4195 | list_for_each_entry(cachep, &slab_caches, list) { | |
4196 | if (!strcmp(cachep->name, kbuf)) { | |
4197 | if (limit < 1 || batchcount < 1 || | |
4198 | batchcount > limit || shared < 0) { | |
4199 | res = 0; | |
4200 | } else { | |
4201 | res = do_tune_cpucache(cachep, limit, | |
4202 | batchcount, shared, | |
4203 | GFP_KERNEL); | |
4204 | } | |
4205 | break; | |
4206 | } | |
4207 | } | |
4208 | mutex_unlock(&slab_mutex); | |
4209 | if (res >= 0) | |
4210 | res = count; | |
4211 | return res; | |
4212 | } | |
4213 | ||
4214 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
4215 | ||
4216 | static inline int add_caller(unsigned long *n, unsigned long v) | |
4217 | { | |
4218 | unsigned long *p; | |
4219 | int l; | |
4220 | if (!v) | |
4221 | return 1; | |
4222 | l = n[1]; | |
4223 | p = n + 2; | |
4224 | while (l) { | |
4225 | int i = l/2; | |
4226 | unsigned long *q = p + 2 * i; | |
4227 | if (*q == v) { | |
4228 | q[1]++; | |
4229 | return 1; | |
4230 | } | |
4231 | if (*q > v) { | |
4232 | l = i; | |
4233 | } else { | |
4234 | p = q + 2; | |
4235 | l -= i + 1; | |
4236 | } | |
4237 | } | |
4238 | if (++n[1] == n[0]) | |
4239 | return 0; | |
4240 | memmove(p + 2, p, n[1] * 2 * sizeof(unsigned long) - ((void *)p - (void *)n)); | |
4241 | p[0] = v; | |
4242 | p[1] = 1; | |
4243 | return 1; | |
4244 | } | |
4245 | ||
4246 | static void handle_slab(unsigned long *n, struct kmem_cache *c, | |
4247 | struct page *page) | |
4248 | { | |
4249 | void *p; | |
4250 | int i, j; | |
4251 | unsigned long v; | |
4252 | ||
4253 | if (n[0] == n[1]) | |
4254 | return; | |
4255 | for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) { | |
4256 | bool active = true; | |
4257 | ||
4258 | for (j = page->active; j < c->num; j++) { | |
4259 | if (get_free_obj(page, j) == i) { | |
4260 | active = false; | |
4261 | break; | |
4262 | } | |
4263 | } | |
4264 | ||
4265 | if (!active) | |
4266 | continue; | |
4267 | ||
4268 | /* | |
4269 | * probe_kernel_read() is used for DEBUG_PAGEALLOC. page table | |
4270 | * mapping is established when actual object allocation and | |
4271 | * we could mistakenly access the unmapped object in the cpu | |
4272 | * cache. | |
4273 | */ | |
4274 | if (probe_kernel_read(&v, dbg_userword(c, p), sizeof(v))) | |
4275 | continue; | |
4276 | ||
4277 | if (!add_caller(n, v)) | |
4278 | return; | |
4279 | } | |
4280 | } | |
4281 | ||
4282 | static void show_symbol(struct seq_file *m, unsigned long address) | |
4283 | { | |
4284 | #ifdef CONFIG_KALLSYMS | |
4285 | unsigned long offset, size; | |
4286 | char modname[MODULE_NAME_LEN], name[KSYM_NAME_LEN]; | |
4287 | ||
4288 | if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { | |
4289 | seq_printf(m, "%s+%#lx/%#lx", name, offset, size); | |
4290 | if (modname[0]) | |
4291 | seq_printf(m, " [%s]", modname); | |
4292 | return; | |
4293 | } | |
4294 | #endif | |
4295 | seq_printf(m, "%p", (void *)address); | |
4296 | } | |
4297 | ||
4298 | static int leaks_show(struct seq_file *m, void *p) | |
4299 | { | |
4300 | struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list); | |
4301 | struct page *page; | |
4302 | struct kmem_cache_node *n; | |
4303 | const char *name; | |
4304 | unsigned long *x = m->private; | |
4305 | int node; | |
4306 | int i; | |
4307 | ||
4308 | if (!(cachep->flags & SLAB_STORE_USER)) | |
4309 | return 0; | |
4310 | if (!(cachep->flags & SLAB_RED_ZONE)) | |
4311 | return 0; | |
4312 | ||
4313 | /* | |
4314 | * Set store_user_clean and start to grab stored user information | |
4315 | * for all objects on this cache. If some alloc/free requests comes | |
4316 | * during the processing, information would be wrong so restart | |
4317 | * whole processing. | |
4318 | */ | |
4319 | do { | |
4320 | set_store_user_clean(cachep); | |
4321 | drain_cpu_caches(cachep); | |
4322 | ||
4323 | x[1] = 0; | |
4324 | ||
4325 | for_each_kmem_cache_node(cachep, node, n) { | |
4326 | ||
4327 | check_irq_on(); | |
4328 | spin_lock_irq(&n->list_lock); | |
4329 | ||
4330 | list_for_each_entry(page, &n->slabs_full, lru) | |
4331 | handle_slab(x, cachep, page); | |
4332 | list_for_each_entry(page, &n->slabs_partial, lru) | |
4333 | handle_slab(x, cachep, page); | |
4334 | spin_unlock_irq(&n->list_lock); | |
4335 | } | |
4336 | } while (!is_store_user_clean(cachep)); | |
4337 | ||
4338 | name = cachep->name; | |
4339 | if (x[0] == x[1]) { | |
4340 | /* Increase the buffer size */ | |
4341 | mutex_unlock(&slab_mutex); | |
4342 | m->private = kzalloc(x[0] * 4 * sizeof(unsigned long), GFP_KERNEL); | |
4343 | if (!m->private) { | |
4344 | /* Too bad, we are really out */ | |
4345 | m->private = x; | |
4346 | mutex_lock(&slab_mutex); | |
4347 | return -ENOMEM; | |
4348 | } | |
4349 | *(unsigned long *)m->private = x[0] * 2; | |
4350 | kfree(x); | |
4351 | mutex_lock(&slab_mutex); | |
4352 | /* Now make sure this entry will be retried */ | |
4353 | m->count = m->size; | |
4354 | return 0; | |
4355 | } | |
4356 | for (i = 0; i < x[1]; i++) { | |
4357 | seq_printf(m, "%s: %lu ", name, x[2*i+3]); | |
4358 | show_symbol(m, x[2*i+2]); | |
4359 | seq_putc(m, '\n'); | |
4360 | } | |
4361 | ||
4362 | return 0; | |
4363 | } | |
4364 | ||
4365 | static const struct seq_operations slabstats_op = { | |
4366 | .start = slab_start, | |
4367 | .next = slab_next, | |
4368 | .stop = slab_stop, | |
4369 | .show = leaks_show, | |
4370 | }; | |
4371 | ||
4372 | static int slabstats_open(struct inode *inode, struct file *file) | |
4373 | { | |
4374 | unsigned long *n; | |
4375 | ||
4376 | n = __seq_open_private(file, &slabstats_op, PAGE_SIZE); | |
4377 | if (!n) | |
4378 | return -ENOMEM; | |
4379 | ||
4380 | *n = PAGE_SIZE / (2 * sizeof(unsigned long)); | |
4381 | ||
4382 | return 0; | |
4383 | } | |
4384 | ||
4385 | static const struct file_operations proc_slabstats_operations = { | |
4386 | .open = slabstats_open, | |
4387 | .read = seq_read, | |
4388 | .llseek = seq_lseek, | |
4389 | .release = seq_release_private, | |
4390 | }; | |
4391 | #endif | |
4392 | ||
4393 | static int __init slab_proc_init(void) | |
4394 | { | |
4395 | #ifdef CONFIG_DEBUG_SLAB_LEAK | |
4396 | proc_create("slab_allocators", 0, NULL, &proc_slabstats_operations); | |
4397 | #endif | |
4398 | return 0; | |
4399 | } | |
4400 | module_init(slab_proc_init); | |
4401 | #endif | |
4402 | ||
4403 | #ifdef CONFIG_HARDENED_USERCOPY | |
4404 | /* | |
4405 | * Rejects objects that are incorrectly sized. | |
4406 | * | |
4407 | * Returns NULL if check passes, otherwise const char * to name of cache | |
4408 | * to indicate an error. | |
4409 | */ | |
4410 | const char *__check_heap_object(const void *ptr, unsigned long n, | |
4411 | struct page *page) | |
4412 | { | |
4413 | struct kmem_cache *cachep; | |
4414 | unsigned int objnr; | |
4415 | unsigned long offset; | |
4416 | ||
4417 | /* Find and validate object. */ | |
4418 | cachep = page->slab_cache; | |
4419 | objnr = obj_to_index(cachep, page, (void *)ptr); | |
4420 | BUG_ON(objnr >= cachep->num); | |
4421 | ||
4422 | /* Find offset within object. */ | |
4423 | offset = ptr - index_to_obj(cachep, page, objnr) - obj_offset(cachep); | |
4424 | ||
4425 | /* Allow address range falling entirely within object size. */ | |
4426 | if (offset <= cachep->object_size && n <= cachep->object_size - offset) | |
4427 | return NULL; | |
4428 | ||
4429 | return cachep->name; | |
4430 | } | |
4431 | #endif /* CONFIG_HARDENED_USERCOPY */ | |
4432 | ||
4433 | /** | |
4434 | * ksize - get the actual amount of memory allocated for a given object | |
4435 | * @objp: Pointer to the object | |
4436 | * | |
4437 | * kmalloc may internally round up allocations and return more memory | |
4438 | * than requested. ksize() can be used to determine the actual amount of | |
4439 | * memory allocated. The caller may use this additional memory, even though | |
4440 | * a smaller amount of memory was initially specified with the kmalloc call. | |
4441 | * The caller must guarantee that objp points to a valid object previously | |
4442 | * allocated with either kmalloc() or kmem_cache_alloc(). The object | |
4443 | * must not be freed during the duration of the call. | |
4444 | */ | |
4445 | size_t ksize(const void *objp) | |
4446 | { | |
4447 | size_t size; | |
4448 | ||
4449 | BUG_ON(!objp); | |
4450 | if (unlikely(objp == ZERO_SIZE_PTR)) | |
4451 | return 0; | |
4452 | ||
4453 | size = virt_to_cache(objp)->object_size; | |
4454 | /* We assume that ksize callers could use the whole allocated area, | |
4455 | * so we need to unpoison this area. | |
4456 | */ | |
4457 | kasan_unpoison_shadow(objp, size); | |
4458 | ||
4459 | return size; | |
4460 | } | |
4461 | EXPORT_SYMBOL(ksize); |