Commit | Line | Data |
---|---|---|
81819f0f CL |
1 | /* |
2 | * SLUB: A slab allocator that limits cache line use instead of queuing | |
3 | * objects in per cpu and per node lists. | |
4 | * | |
5 | * The allocator synchronizes using per slab locks and only | |
6 | * uses a centralized lock to manage a pool of partial slabs. | |
7 | * | |
8 | * (C) 2007 SGI, Christoph Lameter <clameter@sgi.com> | |
9 | */ | |
10 | ||
11 | #include <linux/mm.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/bit_spinlock.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/bitops.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/seq_file.h> | |
18 | #include <linux/cpu.h> | |
19 | #include <linux/cpuset.h> | |
20 | #include <linux/mempolicy.h> | |
21 | #include <linux/ctype.h> | |
22 | #include <linux/kallsyms.h> | |
23 | ||
24 | /* | |
25 | * Lock order: | |
26 | * 1. slab_lock(page) | |
27 | * 2. slab->list_lock | |
28 | * | |
29 | * The slab_lock protects operations on the object of a particular | |
30 | * slab and its metadata in the page struct. If the slab lock | |
31 | * has been taken then no allocations nor frees can be performed | |
32 | * on the objects in the slab nor can the slab be added or removed | |
33 | * from the partial or full lists since this would mean modifying | |
34 | * the page_struct of the slab. | |
35 | * | |
36 | * The list_lock protects the partial and full list on each node and | |
37 | * the partial slab counter. If taken then no new slabs may be added or | |
38 | * removed from the lists nor make the number of partial slabs be modified. | |
39 | * (Note that the total number of slabs is an atomic value that may be | |
40 | * modified without taking the list lock). | |
41 | * | |
42 | * The list_lock is a centralized lock and thus we avoid taking it as | |
43 | * much as possible. As long as SLUB does not have to handle partial | |
44 | * slabs, operations can continue without any centralized lock. F.e. | |
45 | * allocating a long series of objects that fill up slabs does not require | |
46 | * the list lock. | |
47 | * | |
48 | * The lock order is sometimes inverted when we are trying to get a slab | |
49 | * off a list. We take the list_lock and then look for a page on the list | |
50 | * to use. While we do that objects in the slabs may be freed. We can | |
51 | * only operate on the slab if we have also taken the slab_lock. So we use | |
52 | * a slab_trylock() on the slab. If trylock was successful then no frees | |
53 | * can occur anymore and we can use the slab for allocations etc. If the | |
54 | * slab_trylock() does not succeed then frees are in progress in the slab and | |
55 | * we must stay away from it for a while since we may cause a bouncing | |
56 | * cacheline if we try to acquire the lock. So go onto the next slab. | |
57 | * If all pages are busy then we may allocate a new slab instead of reusing | |
58 | * a partial slab. A new slab has noone operating on it and thus there is | |
59 | * no danger of cacheline contention. | |
60 | * | |
61 | * Interrupts are disabled during allocation and deallocation in order to | |
62 | * make the slab allocator safe to use in the context of an irq. In addition | |
63 | * interrupts are disabled to ensure that the processor does not change | |
64 | * while handling per_cpu slabs, due to kernel preemption. | |
65 | * | |
66 | * SLUB assigns one slab for allocation to each processor. | |
67 | * Allocations only occur from these slabs called cpu slabs. | |
68 | * | |
69 | * Slabs with free elements are kept on a partial list. | |
70 | * There is no list for full slabs. If an object in a full slab is | |
71 | * freed then the slab will show up again on the partial lists. | |
72 | * Otherwise there is no need to track full slabs unless we have to | |
73 | * track full slabs for debugging purposes. | |
74 | * | |
75 | * Slabs are freed when they become empty. Teardown and setup is | |
76 | * minimal so we rely on the page allocators per cpu caches for | |
77 | * fast frees and allocs. | |
78 | * | |
79 | * Overloading of page flags that are otherwise used for LRU management. | |
80 | * | |
81 | * PageActive The slab is used as a cpu cache. Allocations | |
82 | * may be performed from the slab. The slab is not | |
83 | * on any slab list and cannot be moved onto one. | |
84 | * | |
85 | * PageError Slab requires special handling due to debug | |
86 | * options set. This moves slab handling out of | |
87 | * the fast path. | |
88 | */ | |
89 | ||
90 | /* | |
91 | * Issues still to be resolved: | |
92 | * | |
93 | * - The per cpu array is updated for each new slab and and is a remote | |
94 | * cacheline for most nodes. This could become a bouncing cacheline given | |
95 | * enough frequent updates. There are 16 pointers in a cacheline.so at | |
96 | * max 16 cpus could compete. Likely okay. | |
97 | * | |
98 | * - Support PAGE_ALLOC_DEBUG. Should be easy to do. | |
99 | * | |
100 | * - Support DEBUG_SLAB_LEAK. Trouble is we do not know where the full | |
101 | * slabs are in SLUB. | |
102 | * | |
103 | * - SLAB_DEBUG_INITIAL is not supported but I have never seen a use of | |
104 | * it. | |
105 | * | |
106 | * - Variable sizing of the per node arrays | |
107 | */ | |
108 | ||
109 | /* Enable to test recovery from slab corruption on boot */ | |
110 | #undef SLUB_RESILIENCY_TEST | |
111 | ||
112 | #if PAGE_SHIFT <= 12 | |
113 | ||
114 | /* | |
115 | * Small page size. Make sure that we do not fragment memory | |
116 | */ | |
117 | #define DEFAULT_MAX_ORDER 1 | |
118 | #define DEFAULT_MIN_OBJECTS 4 | |
119 | ||
120 | #else | |
121 | ||
122 | /* | |
123 | * Large page machines are customarily able to handle larger | |
124 | * page orders. | |
125 | */ | |
126 | #define DEFAULT_MAX_ORDER 2 | |
127 | #define DEFAULT_MIN_OBJECTS 8 | |
128 | ||
129 | #endif | |
130 | ||
131 | /* | |
132 | * Flags from the regular SLAB that SLUB does not support: | |
133 | */ | |
134 | #define SLUB_UNIMPLEMENTED (SLAB_DEBUG_INITIAL) | |
135 | ||
136 | #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \ | |
137 | SLAB_POISON | SLAB_STORE_USER) | |
138 | /* | |
139 | * Set of flags that will prevent slab merging | |
140 | */ | |
141 | #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ | |
142 | SLAB_TRACE | SLAB_DESTROY_BY_RCU) | |
143 | ||
144 | #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ | |
145 | SLAB_CACHE_DMA) | |
146 | ||
147 | #ifndef ARCH_KMALLOC_MINALIGN | |
148 | #define ARCH_KMALLOC_MINALIGN sizeof(void *) | |
149 | #endif | |
150 | ||
151 | #ifndef ARCH_SLAB_MINALIGN | |
152 | #define ARCH_SLAB_MINALIGN sizeof(void *) | |
153 | #endif | |
154 | ||
155 | /* Internal SLUB flags */ | |
156 | #define __OBJECT_POISON 0x80000000 /* Poison object */ | |
157 | ||
158 | static int kmem_size = sizeof(struct kmem_cache); | |
159 | ||
160 | #ifdef CONFIG_SMP | |
161 | static struct notifier_block slab_notifier; | |
162 | #endif | |
163 | ||
164 | static enum { | |
165 | DOWN, /* No slab functionality available */ | |
166 | PARTIAL, /* kmem_cache_open() works but kmalloc does not */ | |
167 | UP, /* Everything works */ | |
168 | SYSFS /* Sysfs up */ | |
169 | } slab_state = DOWN; | |
170 | ||
171 | /* A list of all slab caches on the system */ | |
172 | static DECLARE_RWSEM(slub_lock); | |
173 | LIST_HEAD(slab_caches); | |
174 | ||
175 | #ifdef CONFIG_SYSFS | |
176 | static int sysfs_slab_add(struct kmem_cache *); | |
177 | static int sysfs_slab_alias(struct kmem_cache *, const char *); | |
178 | static void sysfs_slab_remove(struct kmem_cache *); | |
179 | #else | |
180 | static int sysfs_slab_add(struct kmem_cache *s) { return 0; } | |
181 | static int sysfs_slab_alias(struct kmem_cache *s, const char *p) { return 0; } | |
182 | static void sysfs_slab_remove(struct kmem_cache *s) {} | |
183 | #endif | |
184 | ||
185 | /******************************************************************** | |
186 | * Core slab cache functions | |
187 | *******************************************************************/ | |
188 | ||
189 | int slab_is_available(void) | |
190 | { | |
191 | return slab_state >= UP; | |
192 | } | |
193 | ||
194 | static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) | |
195 | { | |
196 | #ifdef CONFIG_NUMA | |
197 | return s->node[node]; | |
198 | #else | |
199 | return &s->local_node; | |
200 | #endif | |
201 | } | |
202 | ||
203 | /* | |
204 | * Object debugging | |
205 | */ | |
206 | static void print_section(char *text, u8 *addr, unsigned int length) | |
207 | { | |
208 | int i, offset; | |
209 | int newline = 1; | |
210 | char ascii[17]; | |
211 | ||
212 | ascii[16] = 0; | |
213 | ||
214 | for (i = 0; i < length; i++) { | |
215 | if (newline) { | |
216 | printk(KERN_ERR "%10s 0x%p: ", text, addr + i); | |
217 | newline = 0; | |
218 | } | |
219 | printk(" %02x", addr[i]); | |
220 | offset = i % 16; | |
221 | ascii[offset] = isgraph(addr[i]) ? addr[i] : '.'; | |
222 | if (offset == 15) { | |
223 | printk(" %s\n",ascii); | |
224 | newline = 1; | |
225 | } | |
226 | } | |
227 | if (!newline) { | |
228 | i %= 16; | |
229 | while (i < 16) { | |
230 | printk(" "); | |
231 | ascii[i] = ' '; | |
232 | i++; | |
233 | } | |
234 | printk(" %s\n", ascii); | |
235 | } | |
236 | } | |
237 | ||
238 | /* | |
239 | * Slow version of get and set free pointer. | |
240 | * | |
241 | * This requires touching the cache lines of kmem_cache. | |
242 | * The offset can also be obtained from the page. In that | |
243 | * case it is in the cacheline that we already need to touch. | |
244 | */ | |
245 | static void *get_freepointer(struct kmem_cache *s, void *object) | |
246 | { | |
247 | return *(void **)(object + s->offset); | |
248 | } | |
249 | ||
250 | static void set_freepointer(struct kmem_cache *s, void *object, void *fp) | |
251 | { | |
252 | *(void **)(object + s->offset) = fp; | |
253 | } | |
254 | ||
255 | /* | |
256 | * Tracking user of a slab. | |
257 | */ | |
258 | struct track { | |
259 | void *addr; /* Called from address */ | |
260 | int cpu; /* Was running on cpu */ | |
261 | int pid; /* Pid context */ | |
262 | unsigned long when; /* When did the operation occur */ | |
263 | }; | |
264 | ||
265 | enum track_item { TRACK_ALLOC, TRACK_FREE }; | |
266 | ||
267 | static struct track *get_track(struct kmem_cache *s, void *object, | |
268 | enum track_item alloc) | |
269 | { | |
270 | struct track *p; | |
271 | ||
272 | if (s->offset) | |
273 | p = object + s->offset + sizeof(void *); | |
274 | else | |
275 | p = object + s->inuse; | |
276 | ||
277 | return p + alloc; | |
278 | } | |
279 | ||
280 | static void set_track(struct kmem_cache *s, void *object, | |
281 | enum track_item alloc, void *addr) | |
282 | { | |
283 | struct track *p; | |
284 | ||
285 | if (s->offset) | |
286 | p = object + s->offset + sizeof(void *); | |
287 | else | |
288 | p = object + s->inuse; | |
289 | ||
290 | p += alloc; | |
291 | if (addr) { | |
292 | p->addr = addr; | |
293 | p->cpu = smp_processor_id(); | |
294 | p->pid = current ? current->pid : -1; | |
295 | p->when = jiffies; | |
296 | } else | |
297 | memset(p, 0, sizeof(struct track)); | |
298 | } | |
299 | ||
300 | #define set_tracking(__s, __o, __a) set_track(__s, __o, __a, \ | |
301 | __builtin_return_address(0)) | |
302 | ||
303 | static void init_tracking(struct kmem_cache *s, void *object) | |
304 | { | |
305 | if (s->flags & SLAB_STORE_USER) { | |
306 | set_track(s, object, TRACK_FREE, NULL); | |
307 | set_track(s, object, TRACK_ALLOC, NULL); | |
308 | } | |
309 | } | |
310 | ||
311 | static void print_track(const char *s, struct track *t) | |
312 | { | |
313 | if (!t->addr) | |
314 | return; | |
315 | ||
316 | printk(KERN_ERR "%s: ", s); | |
317 | __print_symbol("%s", (unsigned long)t->addr); | |
318 | printk(" jiffies_ago=%lu cpu=%u pid=%d\n", jiffies - t->when, t->cpu, t->pid); | |
319 | } | |
320 | ||
321 | static void print_trailer(struct kmem_cache *s, u8 *p) | |
322 | { | |
323 | unsigned int off; /* Offset of last byte */ | |
324 | ||
325 | if (s->flags & SLAB_RED_ZONE) | |
326 | print_section("Redzone", p + s->objsize, | |
327 | s->inuse - s->objsize); | |
328 | ||
329 | printk(KERN_ERR "FreePointer 0x%p -> 0x%p\n", | |
330 | p + s->offset, | |
331 | get_freepointer(s, p)); | |
332 | ||
333 | if (s->offset) | |
334 | off = s->offset + sizeof(void *); | |
335 | else | |
336 | off = s->inuse; | |
337 | ||
338 | if (s->flags & SLAB_STORE_USER) { | |
339 | print_track("Last alloc", get_track(s, p, TRACK_ALLOC)); | |
340 | print_track("Last free ", get_track(s, p, TRACK_FREE)); | |
341 | off += 2 * sizeof(struct track); | |
342 | } | |
343 | ||
344 | if (off != s->size) | |
345 | /* Beginning of the filler is the free pointer */ | |
346 | print_section("Filler", p + off, s->size - off); | |
347 | } | |
348 | ||
349 | static void object_err(struct kmem_cache *s, struct page *page, | |
350 | u8 *object, char *reason) | |
351 | { | |
352 | u8 *addr = page_address(page); | |
353 | ||
354 | printk(KERN_ERR "*** SLUB %s: %s@0x%p slab 0x%p\n", | |
355 | s->name, reason, object, page); | |
356 | printk(KERN_ERR " offset=%tu flags=0x%04lx inuse=%u freelist=0x%p\n", | |
357 | object - addr, page->flags, page->inuse, page->freelist); | |
358 | if (object > addr + 16) | |
359 | print_section("Bytes b4", object - 16, 16); | |
360 | print_section("Object", object, min(s->objsize, 128)); | |
361 | print_trailer(s, object); | |
362 | dump_stack(); | |
363 | } | |
364 | ||
365 | static void slab_err(struct kmem_cache *s, struct page *page, char *reason, ...) | |
366 | { | |
367 | va_list args; | |
368 | char buf[100]; | |
369 | ||
370 | va_start(args, reason); | |
371 | vsnprintf(buf, sizeof(buf), reason, args); | |
372 | va_end(args); | |
373 | printk(KERN_ERR "*** SLUB %s: %s in slab @0x%p\n", s->name, buf, | |
374 | page); | |
375 | dump_stack(); | |
376 | } | |
377 | ||
378 | static void init_object(struct kmem_cache *s, void *object, int active) | |
379 | { | |
380 | u8 *p = object; | |
381 | ||
382 | if (s->flags & __OBJECT_POISON) { | |
383 | memset(p, POISON_FREE, s->objsize - 1); | |
384 | p[s->objsize -1] = POISON_END; | |
385 | } | |
386 | ||
387 | if (s->flags & SLAB_RED_ZONE) | |
388 | memset(p + s->objsize, | |
389 | active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE, | |
390 | s->inuse - s->objsize); | |
391 | } | |
392 | ||
393 | static int check_bytes(u8 *start, unsigned int value, unsigned int bytes) | |
394 | { | |
395 | while (bytes) { | |
396 | if (*start != (u8)value) | |
397 | return 0; | |
398 | start++; | |
399 | bytes--; | |
400 | } | |
401 | return 1; | |
402 | } | |
403 | ||
404 | ||
405 | static int check_valid_pointer(struct kmem_cache *s, struct page *page, | |
406 | void *object) | |
407 | { | |
408 | void *base; | |
409 | ||
410 | if (!object) | |
411 | return 1; | |
412 | ||
413 | base = page_address(page); | |
414 | if (object < base || object >= base + s->objects * s->size || | |
415 | (object - base) % s->size) { | |
416 | return 0; | |
417 | } | |
418 | ||
419 | return 1; | |
420 | } | |
421 | ||
422 | /* | |
423 | * Object layout: | |
424 | * | |
425 | * object address | |
426 | * Bytes of the object to be managed. | |
427 | * If the freepointer may overlay the object then the free | |
428 | * pointer is the first word of the object. | |
429 | * Poisoning uses 0x6b (POISON_FREE) and the last byte is | |
430 | * 0xa5 (POISON_END) | |
431 | * | |
432 | * object + s->objsize | |
433 | * Padding to reach word boundary. This is also used for Redzoning. | |
434 | * Padding is extended to word size if Redzoning is enabled | |
435 | * and objsize == inuse. | |
436 | * We fill with 0xbb (RED_INACTIVE) for inactive objects and with | |
437 | * 0xcc (RED_ACTIVE) for objects in use. | |
438 | * | |
439 | * object + s->inuse | |
440 | * A. Free pointer (if we cannot overwrite object on free) | |
441 | * B. Tracking data for SLAB_STORE_USER | |
442 | * C. Padding to reach required alignment boundary | |
443 | * Padding is done using 0x5a (POISON_INUSE) | |
444 | * | |
445 | * object + s->size | |
446 | * | |
447 | * If slabcaches are merged then the objsize and inuse boundaries are to | |
448 | * be ignored. And therefore no slab options that rely on these boundaries | |
449 | * may be used with merged slabcaches. | |
450 | */ | |
451 | ||
452 | static void restore_bytes(struct kmem_cache *s, char *message, u8 data, | |
453 | void *from, void *to) | |
454 | { | |
455 | printk(KERN_ERR "@@@ SLUB: %s Restoring %s (0x%x) from 0x%p-0x%p\n", | |
456 | s->name, message, data, from, to - 1); | |
457 | memset(from, data, to - from); | |
458 | } | |
459 | ||
460 | static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p) | |
461 | { | |
462 | unsigned long off = s->inuse; /* The end of info */ | |
463 | ||
464 | if (s->offset) | |
465 | /* Freepointer is placed after the object. */ | |
466 | off += sizeof(void *); | |
467 | ||
468 | if (s->flags & SLAB_STORE_USER) | |
469 | /* We also have user information there */ | |
470 | off += 2 * sizeof(struct track); | |
471 | ||
472 | if (s->size == off) | |
473 | return 1; | |
474 | ||
475 | if (check_bytes(p + off, POISON_INUSE, s->size - off)) | |
476 | return 1; | |
477 | ||
478 | object_err(s, page, p, "Object padding check fails"); | |
479 | ||
480 | /* | |
481 | * Restore padding | |
482 | */ | |
483 | restore_bytes(s, "object padding", POISON_INUSE, p + off, p + s->size); | |
484 | return 0; | |
485 | } | |
486 | ||
487 | static int slab_pad_check(struct kmem_cache *s, struct page *page) | |
488 | { | |
489 | u8 *p; | |
490 | int length, remainder; | |
491 | ||
492 | if (!(s->flags & SLAB_POISON)) | |
493 | return 1; | |
494 | ||
495 | p = page_address(page); | |
496 | length = s->objects * s->size; | |
497 | remainder = (PAGE_SIZE << s->order) - length; | |
498 | if (!remainder) | |
499 | return 1; | |
500 | ||
501 | if (!check_bytes(p + length, POISON_INUSE, remainder)) { | |
502 | printk(KERN_ERR "SLUB: %s slab 0x%p: Padding fails check\n", | |
503 | s->name, p); | |
504 | dump_stack(); | |
505 | restore_bytes(s, "slab padding", POISON_INUSE, p + length, | |
506 | p + length + remainder); | |
507 | return 0; | |
508 | } | |
509 | return 1; | |
510 | } | |
511 | ||
512 | static int check_object(struct kmem_cache *s, struct page *page, | |
513 | void *object, int active) | |
514 | { | |
515 | u8 *p = object; | |
516 | u8 *endobject = object + s->objsize; | |
517 | ||
518 | if (s->flags & SLAB_RED_ZONE) { | |
519 | unsigned int red = | |
520 | active ? SLUB_RED_ACTIVE : SLUB_RED_INACTIVE; | |
521 | ||
522 | if (!check_bytes(endobject, red, s->inuse - s->objsize)) { | |
523 | object_err(s, page, object, | |
524 | active ? "Redzone Active" : "Redzone Inactive"); | |
525 | restore_bytes(s, "redzone", red, | |
526 | endobject, object + s->inuse); | |
527 | return 0; | |
528 | } | |
529 | } else { | |
530 | if ((s->flags & SLAB_POISON) && s->objsize < s->inuse && | |
531 | !check_bytes(endobject, POISON_INUSE, | |
532 | s->inuse - s->objsize)) { | |
533 | object_err(s, page, p, "Alignment padding check fails"); | |
534 | /* | |
535 | * Fix it so that there will not be another report. | |
536 | * | |
537 | * Hmmm... We may be corrupting an object that now expects | |
538 | * to be longer than allowed. | |
539 | */ | |
540 | restore_bytes(s, "alignment padding", POISON_INUSE, | |
541 | endobject, object + s->inuse); | |
542 | } | |
543 | } | |
544 | ||
545 | if (s->flags & SLAB_POISON) { | |
546 | if (!active && (s->flags & __OBJECT_POISON) && | |
547 | (!check_bytes(p, POISON_FREE, s->objsize - 1) || | |
548 | p[s->objsize - 1] != POISON_END)) { | |
549 | ||
550 | object_err(s, page, p, "Poison check failed"); | |
551 | restore_bytes(s, "Poison", POISON_FREE, | |
552 | p, p + s->objsize -1); | |
553 | restore_bytes(s, "Poison", POISON_END, | |
554 | p + s->objsize - 1, p + s->objsize); | |
555 | return 0; | |
556 | } | |
557 | /* | |
558 | * check_pad_bytes cleans up on its own. | |
559 | */ | |
560 | check_pad_bytes(s, page, p); | |
561 | } | |
562 | ||
563 | if (!s->offset && active) | |
564 | /* | |
565 | * Object and freepointer overlap. Cannot check | |
566 | * freepointer while object is allocated. | |
567 | */ | |
568 | return 1; | |
569 | ||
570 | /* Check free pointer validity */ | |
571 | if (!check_valid_pointer(s, page, get_freepointer(s, p))) { | |
572 | object_err(s, page, p, "Freepointer corrupt"); | |
573 | /* | |
574 | * No choice but to zap it and thus loose the remainder | |
575 | * of the free objects in this slab. May cause | |
576 | * another error because the object count maybe | |
577 | * wrong now. | |
578 | */ | |
579 | set_freepointer(s, p, NULL); | |
580 | return 0; | |
581 | } | |
582 | return 1; | |
583 | } | |
584 | ||
585 | static int check_slab(struct kmem_cache *s, struct page *page) | |
586 | { | |
587 | VM_BUG_ON(!irqs_disabled()); | |
588 | ||
589 | if (!PageSlab(page)) { | |
590 | printk(KERN_ERR "SLUB: %s Not a valid slab page @0x%p " | |
591 | "flags=%lx mapping=0x%p count=%d \n", | |
592 | s->name, page, page->flags, page->mapping, | |
593 | page_count(page)); | |
594 | return 0; | |
595 | } | |
596 | if (page->offset * sizeof(void *) != s->offset) { | |
597 | printk(KERN_ERR "SLUB: %s Corrupted offset %lu in slab @0x%p" | |
598 | " flags=0x%lx mapping=0x%p count=%d\n", | |
599 | s->name, | |
600 | (unsigned long)(page->offset * sizeof(void *)), | |
601 | page, | |
602 | page->flags, | |
603 | page->mapping, | |
604 | page_count(page)); | |
605 | dump_stack(); | |
606 | return 0; | |
607 | } | |
608 | if (page->inuse > s->objects) { | |
609 | printk(KERN_ERR "SLUB: %s Inuse %u > max %u in slab " | |
610 | "page @0x%p flags=%lx mapping=0x%p count=%d\n", | |
611 | s->name, page->inuse, s->objects, page, page->flags, | |
612 | page->mapping, page_count(page)); | |
613 | dump_stack(); | |
614 | return 0; | |
615 | } | |
616 | /* Slab_pad_check fixes things up after itself */ | |
617 | slab_pad_check(s, page); | |
618 | return 1; | |
619 | } | |
620 | ||
621 | /* | |
622 | * Determine if a certain object on a page is on the freelist and | |
623 | * therefore free. Must hold the slab lock for cpu slabs to | |
624 | * guarantee that the chains are consistent. | |
625 | */ | |
626 | static int on_freelist(struct kmem_cache *s, struct page *page, void *search) | |
627 | { | |
628 | int nr = 0; | |
629 | void *fp = page->freelist; | |
630 | void *object = NULL; | |
631 | ||
632 | while (fp && nr <= s->objects) { | |
633 | if (fp == search) | |
634 | return 1; | |
635 | if (!check_valid_pointer(s, page, fp)) { | |
636 | if (object) { | |
637 | object_err(s, page, object, | |
638 | "Freechain corrupt"); | |
639 | set_freepointer(s, object, NULL); | |
640 | break; | |
641 | } else { | |
642 | printk(KERN_ERR "SLUB: %s slab 0x%p " | |
643 | "freepointer 0x%p corrupted.\n", | |
644 | s->name, page, fp); | |
645 | dump_stack(); | |
646 | page->freelist = NULL; | |
647 | page->inuse = s->objects; | |
648 | return 0; | |
649 | } | |
650 | break; | |
651 | } | |
652 | object = fp; | |
653 | fp = get_freepointer(s, object); | |
654 | nr++; | |
655 | } | |
656 | ||
657 | if (page->inuse != s->objects - nr) { | |
658 | printk(KERN_ERR "slab %s: page 0x%p wrong object count." | |
659 | " counter is %d but counted were %d\n", | |
660 | s->name, page, page->inuse, | |
661 | s->objects - nr); | |
662 | page->inuse = s->objects - nr; | |
663 | } | |
664 | return search == NULL; | |
665 | } | |
666 | ||
667 | static int alloc_object_checks(struct kmem_cache *s, struct page *page, | |
668 | void *object) | |
669 | { | |
670 | if (!check_slab(s, page)) | |
671 | goto bad; | |
672 | ||
673 | if (object && !on_freelist(s, page, object)) { | |
674 | printk(KERN_ERR "SLUB: %s Object 0x%p@0x%p " | |
675 | "already allocated.\n", | |
676 | s->name, object, page); | |
677 | goto dump; | |
678 | } | |
679 | ||
680 | if (!check_valid_pointer(s, page, object)) { | |
681 | object_err(s, page, object, "Freelist Pointer check fails"); | |
682 | goto dump; | |
683 | } | |
684 | ||
685 | if (!object) | |
686 | return 1; | |
687 | ||
688 | if (!check_object(s, page, object, 0)) | |
689 | goto bad; | |
690 | init_object(s, object, 1); | |
691 | ||
692 | if (s->flags & SLAB_TRACE) { | |
693 | printk(KERN_INFO "TRACE %s alloc 0x%p inuse=%d fp=0x%p\n", | |
694 | s->name, object, page->inuse, | |
695 | page->freelist); | |
696 | dump_stack(); | |
697 | } | |
698 | return 1; | |
699 | dump: | |
700 | dump_stack(); | |
701 | bad: | |
702 | if (PageSlab(page)) { | |
703 | /* | |
704 | * If this is a slab page then lets do the best we can | |
705 | * to avoid issues in the future. Marking all objects | |
706 | * as used avoids touching the remainder. | |
707 | */ | |
708 | printk(KERN_ERR "@@@ SLUB: %s slab 0x%p. Marking all objects used.\n", | |
709 | s->name, page); | |
710 | page->inuse = s->objects; | |
711 | page->freelist = NULL; | |
712 | /* Fix up fields that may be corrupted */ | |
713 | page->offset = s->offset / sizeof(void *); | |
714 | } | |
715 | return 0; | |
716 | } | |
717 | ||
718 | static int free_object_checks(struct kmem_cache *s, struct page *page, | |
719 | void *object) | |
720 | { | |
721 | if (!check_slab(s, page)) | |
722 | goto fail; | |
723 | ||
724 | if (!check_valid_pointer(s, page, object)) { | |
725 | printk(KERN_ERR "SLUB: %s slab 0x%p invalid " | |
726 | "object pointer 0x%p\n", | |
727 | s->name, page, object); | |
728 | goto fail; | |
729 | } | |
730 | ||
731 | if (on_freelist(s, page, object)) { | |
732 | printk(KERN_ERR "SLUB: %s slab 0x%p object " | |
733 | "0x%p already free.\n", s->name, page, object); | |
734 | goto fail; | |
735 | } | |
736 | ||
737 | if (!check_object(s, page, object, 1)) | |
738 | return 0; | |
739 | ||
740 | if (unlikely(s != page->slab)) { | |
741 | if (!PageSlab(page)) | |
742 | printk(KERN_ERR "slab_free %s size %d: attempt to" | |
743 | "free object(0x%p) outside of slab.\n", | |
744 | s->name, s->size, object); | |
745 | else | |
746 | if (!page->slab) | |
747 | printk(KERN_ERR | |
748 | "slab_free : no slab(NULL) for object 0x%p.\n", | |
749 | object); | |
750 | else | |
751 | printk(KERN_ERR "slab_free %s(%d): object at 0x%p" | |
752 | " belongs to slab %s(%d)\n", | |
753 | s->name, s->size, object, | |
754 | page->slab->name, page->slab->size); | |
755 | goto fail; | |
756 | } | |
757 | if (s->flags & SLAB_TRACE) { | |
758 | printk(KERN_INFO "TRACE %s free 0x%p inuse=%d fp=0x%p\n", | |
759 | s->name, object, page->inuse, | |
760 | page->freelist); | |
761 | print_section("Object", object, s->objsize); | |
762 | dump_stack(); | |
763 | } | |
764 | init_object(s, object, 0); | |
765 | return 1; | |
766 | fail: | |
767 | dump_stack(); | |
768 | printk(KERN_ERR "@@@ SLUB: %s slab 0x%p object at 0x%p not freed.\n", | |
769 | s->name, page, object); | |
770 | return 0; | |
771 | } | |
772 | ||
773 | /* | |
774 | * Slab allocation and freeing | |
775 | */ | |
776 | static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) | |
777 | { | |
778 | struct page * page; | |
779 | int pages = 1 << s->order; | |
780 | ||
781 | if (s->order) | |
782 | flags |= __GFP_COMP; | |
783 | ||
784 | if (s->flags & SLAB_CACHE_DMA) | |
785 | flags |= SLUB_DMA; | |
786 | ||
787 | if (node == -1) | |
788 | page = alloc_pages(flags, s->order); | |
789 | else | |
790 | page = alloc_pages_node(node, flags, s->order); | |
791 | ||
792 | if (!page) | |
793 | return NULL; | |
794 | ||
795 | mod_zone_page_state(page_zone(page), | |
796 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? | |
797 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, | |
798 | pages); | |
799 | ||
800 | return page; | |
801 | } | |
802 | ||
803 | static void setup_object(struct kmem_cache *s, struct page *page, | |
804 | void *object) | |
805 | { | |
806 | if (PageError(page)) { | |
807 | init_object(s, object, 0); | |
808 | init_tracking(s, object); | |
809 | } | |
810 | ||
811 | if (unlikely(s->ctor)) { | |
812 | int mode = SLAB_CTOR_CONSTRUCTOR; | |
813 | ||
814 | if (!(s->flags & __GFP_WAIT)) | |
815 | mode |= SLAB_CTOR_ATOMIC; | |
816 | ||
817 | s->ctor(object, s, mode); | |
818 | } | |
819 | } | |
820 | ||
821 | static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) | |
822 | { | |
823 | struct page *page; | |
824 | struct kmem_cache_node *n; | |
825 | void *start; | |
826 | void *end; | |
827 | void *last; | |
828 | void *p; | |
829 | ||
830 | if (flags & __GFP_NO_GROW) | |
831 | return NULL; | |
832 | ||
833 | BUG_ON(flags & ~(GFP_DMA | GFP_LEVEL_MASK)); | |
834 | ||
835 | if (flags & __GFP_WAIT) | |
836 | local_irq_enable(); | |
837 | ||
838 | page = allocate_slab(s, flags & GFP_LEVEL_MASK, node); | |
839 | if (!page) | |
840 | goto out; | |
841 | ||
842 | n = get_node(s, page_to_nid(page)); | |
843 | if (n) | |
844 | atomic_long_inc(&n->nr_slabs); | |
845 | page->offset = s->offset / sizeof(void *); | |
846 | page->slab = s; | |
847 | page->flags |= 1 << PG_slab; | |
848 | if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON | | |
849 | SLAB_STORE_USER | SLAB_TRACE)) | |
850 | page->flags |= 1 << PG_error; | |
851 | ||
852 | start = page_address(page); | |
853 | end = start + s->objects * s->size; | |
854 | ||
855 | if (unlikely(s->flags & SLAB_POISON)) | |
856 | memset(start, POISON_INUSE, PAGE_SIZE << s->order); | |
857 | ||
858 | last = start; | |
859 | for (p = start + s->size; p < end; p += s->size) { | |
860 | setup_object(s, page, last); | |
861 | set_freepointer(s, last, p); | |
862 | last = p; | |
863 | } | |
864 | setup_object(s, page, last); | |
865 | set_freepointer(s, last, NULL); | |
866 | ||
867 | page->freelist = start; | |
868 | page->inuse = 0; | |
869 | out: | |
870 | if (flags & __GFP_WAIT) | |
871 | local_irq_disable(); | |
872 | return page; | |
873 | } | |
874 | ||
875 | static void __free_slab(struct kmem_cache *s, struct page *page) | |
876 | { | |
877 | int pages = 1 << s->order; | |
878 | ||
879 | if (unlikely(PageError(page) || s->dtor)) { | |
880 | void *start = page_address(page); | |
881 | void *end = start + (pages << PAGE_SHIFT); | |
882 | void *p; | |
883 | ||
884 | slab_pad_check(s, page); | |
885 | for (p = start; p <= end - s->size; p += s->size) { | |
886 | if (s->dtor) | |
887 | s->dtor(p, s, 0); | |
888 | check_object(s, page, p, 0); | |
889 | } | |
890 | } | |
891 | ||
892 | mod_zone_page_state(page_zone(page), | |
893 | (s->flags & SLAB_RECLAIM_ACCOUNT) ? | |
894 | NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE, | |
895 | - pages); | |
896 | ||
897 | page->mapping = NULL; | |
898 | __free_pages(page, s->order); | |
899 | } | |
900 | ||
901 | static void rcu_free_slab(struct rcu_head *h) | |
902 | { | |
903 | struct page *page; | |
904 | ||
905 | page = container_of((struct list_head *)h, struct page, lru); | |
906 | __free_slab(page->slab, page); | |
907 | } | |
908 | ||
909 | static void free_slab(struct kmem_cache *s, struct page *page) | |
910 | { | |
911 | if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { | |
912 | /* | |
913 | * RCU free overloads the RCU head over the LRU | |
914 | */ | |
915 | struct rcu_head *head = (void *)&page->lru; | |
916 | ||
917 | call_rcu(head, rcu_free_slab); | |
918 | } else | |
919 | __free_slab(s, page); | |
920 | } | |
921 | ||
922 | static void discard_slab(struct kmem_cache *s, struct page *page) | |
923 | { | |
924 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); | |
925 | ||
926 | atomic_long_dec(&n->nr_slabs); | |
927 | reset_page_mapcount(page); | |
928 | page->flags &= ~(1 << PG_slab | 1 << PG_error); | |
929 | free_slab(s, page); | |
930 | } | |
931 | ||
932 | /* | |
933 | * Per slab locking using the pagelock | |
934 | */ | |
935 | static __always_inline void slab_lock(struct page *page) | |
936 | { | |
937 | bit_spin_lock(PG_locked, &page->flags); | |
938 | } | |
939 | ||
940 | static __always_inline void slab_unlock(struct page *page) | |
941 | { | |
942 | bit_spin_unlock(PG_locked, &page->flags); | |
943 | } | |
944 | ||
945 | static __always_inline int slab_trylock(struct page *page) | |
946 | { | |
947 | int rc = 1; | |
948 | ||
949 | rc = bit_spin_trylock(PG_locked, &page->flags); | |
950 | return rc; | |
951 | } | |
952 | ||
953 | /* | |
954 | * Management of partially allocated slabs | |
955 | */ | |
956 | static void add_partial(struct kmem_cache *s, struct page *page) | |
957 | { | |
958 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); | |
959 | ||
960 | spin_lock(&n->list_lock); | |
961 | n->nr_partial++; | |
962 | list_add(&page->lru, &n->partial); | |
963 | spin_unlock(&n->list_lock); | |
964 | } | |
965 | ||
966 | static void remove_partial(struct kmem_cache *s, | |
967 | struct page *page) | |
968 | { | |
969 | struct kmem_cache_node *n = get_node(s, page_to_nid(page)); | |
970 | ||
971 | spin_lock(&n->list_lock); | |
972 | list_del(&page->lru); | |
973 | n->nr_partial--; | |
974 | spin_unlock(&n->list_lock); | |
975 | } | |
976 | ||
977 | /* | |
978 | * Lock page and remove it from the partial list | |
979 | * | |
980 | * Must hold list_lock | |
981 | */ | |
982 | static int lock_and_del_slab(struct kmem_cache_node *n, struct page *page) | |
983 | { | |
984 | if (slab_trylock(page)) { | |
985 | list_del(&page->lru); | |
986 | n->nr_partial--; | |
987 | return 1; | |
988 | } | |
989 | return 0; | |
990 | } | |
991 | ||
992 | /* | |
993 | * Try to get a partial slab from a specific node | |
994 | */ | |
995 | static struct page *get_partial_node(struct kmem_cache_node *n) | |
996 | { | |
997 | struct page *page; | |
998 | ||
999 | /* | |
1000 | * Racy check. If we mistakenly see no partial slabs then we | |
1001 | * just allocate an empty slab. If we mistakenly try to get a | |
1002 | * partial slab then get_partials() will return NULL. | |
1003 | */ | |
1004 | if (!n || !n->nr_partial) | |
1005 | return NULL; | |
1006 | ||
1007 | spin_lock(&n->list_lock); | |
1008 | list_for_each_entry(page, &n->partial, lru) | |
1009 | if (lock_and_del_slab(n, page)) | |
1010 | goto out; | |
1011 | page = NULL; | |
1012 | out: | |
1013 | spin_unlock(&n->list_lock); | |
1014 | return page; | |
1015 | } | |
1016 | ||
1017 | /* | |
1018 | * Get a page from somewhere. Search in increasing NUMA | |
1019 | * distances. | |
1020 | */ | |
1021 | static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags) | |
1022 | { | |
1023 | #ifdef CONFIG_NUMA | |
1024 | struct zonelist *zonelist; | |
1025 | struct zone **z; | |
1026 | struct page *page; | |
1027 | ||
1028 | /* | |
1029 | * The defrag ratio allows to configure the tradeoffs between | |
1030 | * inter node defragmentation and node local allocations. | |
1031 | * A lower defrag_ratio increases the tendency to do local | |
1032 | * allocations instead of scanning throught the partial | |
1033 | * lists on other nodes. | |
1034 | * | |
1035 | * If defrag_ratio is set to 0 then kmalloc() always | |
1036 | * returns node local objects. If its higher then kmalloc() | |
1037 | * may return off node objects in order to avoid fragmentation. | |
1038 | * | |
1039 | * A higher ratio means slabs may be taken from other nodes | |
1040 | * thus reducing the number of partial slabs on those nodes. | |
1041 | * | |
1042 | * If /sys/slab/xx/defrag_ratio is set to 100 (which makes | |
1043 | * defrag_ratio = 1000) then every (well almost) allocation | |
1044 | * will first attempt to defrag slab caches on other nodes. This | |
1045 | * means scanning over all nodes to look for partial slabs which | |
1046 | * may be a bit expensive to do on every slab allocation. | |
1047 | */ | |
1048 | if (!s->defrag_ratio || get_cycles() % 1024 > s->defrag_ratio) | |
1049 | return NULL; | |
1050 | ||
1051 | zonelist = &NODE_DATA(slab_node(current->mempolicy)) | |
1052 | ->node_zonelists[gfp_zone(flags)]; | |
1053 | for (z = zonelist->zones; *z; z++) { | |
1054 | struct kmem_cache_node *n; | |
1055 | ||
1056 | n = get_node(s, zone_to_nid(*z)); | |
1057 | ||
1058 | if (n && cpuset_zone_allowed_hardwall(*z, flags) && | |
1059 | n->nr_partial > 2) { | |
1060 | page = get_partial_node(n); | |
1061 | if (page) | |
1062 | return page; | |
1063 | } | |
1064 | } | |
1065 | #endif | |
1066 | return NULL; | |
1067 | } | |
1068 | ||
1069 | /* | |
1070 | * Get a partial page, lock it and return it. | |
1071 | */ | |
1072 | static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node) | |
1073 | { | |
1074 | struct page *page; | |
1075 | int searchnode = (node == -1) ? numa_node_id() : node; | |
1076 | ||
1077 | page = get_partial_node(get_node(s, searchnode)); | |
1078 | if (page || (flags & __GFP_THISNODE)) | |
1079 | return page; | |
1080 | ||
1081 | return get_any_partial(s, flags); | |
1082 | } | |
1083 | ||
1084 | /* | |
1085 | * Move a page back to the lists. | |
1086 | * | |
1087 | * Must be called with the slab lock held. | |
1088 | * | |
1089 | * On exit the slab lock will have been dropped. | |
1090 | */ | |
1091 | static void putback_slab(struct kmem_cache *s, struct page *page) | |
1092 | { | |
1093 | if (page->inuse) { | |
1094 | if (page->freelist) | |
1095 | add_partial(s, page); | |
1096 | slab_unlock(page); | |
1097 | } else { | |
1098 | slab_unlock(page); | |
1099 | discard_slab(s, page); | |
1100 | } | |
1101 | } | |
1102 | ||
1103 | /* | |
1104 | * Remove the cpu slab | |
1105 | */ | |
1106 | static void deactivate_slab(struct kmem_cache *s, struct page *page, int cpu) | |
1107 | { | |
1108 | s->cpu_slab[cpu] = NULL; | |
1109 | ClearPageActive(page); | |
1110 | ||
1111 | putback_slab(s, page); | |
1112 | } | |
1113 | ||
1114 | static void flush_slab(struct kmem_cache *s, struct page *page, int cpu) | |
1115 | { | |
1116 | slab_lock(page); | |
1117 | deactivate_slab(s, page, cpu); | |
1118 | } | |
1119 | ||
1120 | /* | |
1121 | * Flush cpu slab. | |
1122 | * Called from IPI handler with interrupts disabled. | |
1123 | */ | |
1124 | static void __flush_cpu_slab(struct kmem_cache *s, int cpu) | |
1125 | { | |
1126 | struct page *page = s->cpu_slab[cpu]; | |
1127 | ||
1128 | if (likely(page)) | |
1129 | flush_slab(s, page, cpu); | |
1130 | } | |
1131 | ||
1132 | static void flush_cpu_slab(void *d) | |
1133 | { | |
1134 | struct kmem_cache *s = d; | |
1135 | int cpu = smp_processor_id(); | |
1136 | ||
1137 | __flush_cpu_slab(s, cpu); | |
1138 | } | |
1139 | ||
1140 | static void flush_all(struct kmem_cache *s) | |
1141 | { | |
1142 | #ifdef CONFIG_SMP | |
1143 | on_each_cpu(flush_cpu_slab, s, 1, 1); | |
1144 | #else | |
1145 | unsigned long flags; | |
1146 | ||
1147 | local_irq_save(flags); | |
1148 | flush_cpu_slab(s); | |
1149 | local_irq_restore(flags); | |
1150 | #endif | |
1151 | } | |
1152 | ||
1153 | /* | |
1154 | * slab_alloc is optimized to only modify two cachelines on the fast path | |
1155 | * (aside from the stack): | |
1156 | * | |
1157 | * 1. The page struct | |
1158 | * 2. The first cacheline of the object to be allocated. | |
1159 | * | |
1160 | * The only cache lines that are read (apart from code) is the | |
1161 | * per cpu array in the kmem_cache struct. | |
1162 | * | |
1163 | * Fastpath is not possible if we need to get a new slab or have | |
1164 | * debugging enabled (which means all slabs are marked with PageError) | |
1165 | */ | |
1166 | static __always_inline void *slab_alloc(struct kmem_cache *s, | |
1167 | gfp_t gfpflags, int node) | |
1168 | { | |
1169 | struct page *page; | |
1170 | void **object; | |
1171 | unsigned long flags; | |
1172 | int cpu; | |
1173 | ||
1174 | local_irq_save(flags); | |
1175 | cpu = smp_processor_id(); | |
1176 | page = s->cpu_slab[cpu]; | |
1177 | if (!page) | |
1178 | goto new_slab; | |
1179 | ||
1180 | slab_lock(page); | |
1181 | if (unlikely(node != -1 && page_to_nid(page) != node)) | |
1182 | goto another_slab; | |
1183 | redo: | |
1184 | object = page->freelist; | |
1185 | if (unlikely(!object)) | |
1186 | goto another_slab; | |
1187 | if (unlikely(PageError(page))) | |
1188 | goto debug; | |
1189 | ||
1190 | have_object: | |
1191 | page->inuse++; | |
1192 | page->freelist = object[page->offset]; | |
1193 | slab_unlock(page); | |
1194 | local_irq_restore(flags); | |
1195 | return object; | |
1196 | ||
1197 | another_slab: | |
1198 | deactivate_slab(s, page, cpu); | |
1199 | ||
1200 | new_slab: | |
1201 | page = get_partial(s, gfpflags, node); | |
1202 | if (likely(page)) { | |
1203 | have_slab: | |
1204 | s->cpu_slab[cpu] = page; | |
1205 | SetPageActive(page); | |
1206 | goto redo; | |
1207 | } | |
1208 | ||
1209 | page = new_slab(s, gfpflags, node); | |
1210 | if (page) { | |
1211 | cpu = smp_processor_id(); | |
1212 | if (s->cpu_slab[cpu]) { | |
1213 | /* | |
1214 | * Someone else populated the cpu_slab while we enabled | |
1215 | * interrupts, or we have got scheduled on another cpu. | |
1216 | * The page may not be on the requested node. | |
1217 | */ | |
1218 | if (node == -1 || | |
1219 | page_to_nid(s->cpu_slab[cpu]) == node) { | |
1220 | /* | |
1221 | * Current cpuslab is acceptable and we | |
1222 | * want the current one since its cache hot | |
1223 | */ | |
1224 | discard_slab(s, page); | |
1225 | page = s->cpu_slab[cpu]; | |
1226 | slab_lock(page); | |
1227 | goto redo; | |
1228 | } | |
1229 | /* Dump the current slab */ | |
1230 | flush_slab(s, s->cpu_slab[cpu], cpu); | |
1231 | } | |
1232 | slab_lock(page); | |
1233 | goto have_slab; | |
1234 | } | |
1235 | local_irq_restore(flags); | |
1236 | return NULL; | |
1237 | debug: | |
1238 | if (!alloc_object_checks(s, page, object)) | |
1239 | goto another_slab; | |
1240 | if (s->flags & SLAB_STORE_USER) | |
1241 | set_tracking(s, object, TRACK_ALLOC); | |
1242 | goto have_object; | |
1243 | } | |
1244 | ||
1245 | void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) | |
1246 | { | |
1247 | return slab_alloc(s, gfpflags, -1); | |
1248 | } | |
1249 | EXPORT_SYMBOL(kmem_cache_alloc); | |
1250 | ||
1251 | #ifdef CONFIG_NUMA | |
1252 | void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node) | |
1253 | { | |
1254 | return slab_alloc(s, gfpflags, node); | |
1255 | } | |
1256 | EXPORT_SYMBOL(kmem_cache_alloc_node); | |
1257 | #endif | |
1258 | ||
1259 | /* | |
1260 | * The fastpath only writes the cacheline of the page struct and the first | |
1261 | * cacheline of the object. | |
1262 | * | |
1263 | * No special cachelines need to be read | |
1264 | */ | |
1265 | static void slab_free(struct kmem_cache *s, struct page *page, void *x) | |
1266 | { | |
1267 | void *prior; | |
1268 | void **object = (void *)x; | |
1269 | unsigned long flags; | |
1270 | ||
1271 | local_irq_save(flags); | |
1272 | slab_lock(page); | |
1273 | ||
1274 | if (unlikely(PageError(page))) | |
1275 | goto debug; | |
1276 | checks_ok: | |
1277 | prior = object[page->offset] = page->freelist; | |
1278 | page->freelist = object; | |
1279 | page->inuse--; | |
1280 | ||
1281 | if (unlikely(PageActive(page))) | |
1282 | /* | |
1283 | * Cpu slabs are never on partial lists and are | |
1284 | * never freed. | |
1285 | */ | |
1286 | goto out_unlock; | |
1287 | ||
1288 | if (unlikely(!page->inuse)) | |
1289 | goto slab_empty; | |
1290 | ||
1291 | /* | |
1292 | * Objects left in the slab. If it | |
1293 | * was not on the partial list before | |
1294 | * then add it. | |
1295 | */ | |
1296 | if (unlikely(!prior)) | |
1297 | add_partial(s, page); | |
1298 | ||
1299 | out_unlock: | |
1300 | slab_unlock(page); | |
1301 | local_irq_restore(flags); | |
1302 | return; | |
1303 | ||
1304 | slab_empty: | |
1305 | if (prior) | |
1306 | /* | |
1307 | * Partially used slab that is on the partial list. | |
1308 | */ | |
1309 | remove_partial(s, page); | |
1310 | ||
1311 | slab_unlock(page); | |
1312 | discard_slab(s, page); | |
1313 | local_irq_restore(flags); | |
1314 | return; | |
1315 | ||
1316 | debug: | |
1317 | if (free_object_checks(s, page, x)) | |
1318 | goto checks_ok; | |
1319 | goto out_unlock; | |
1320 | } | |
1321 | ||
1322 | void kmem_cache_free(struct kmem_cache *s, void *x) | |
1323 | { | |
1324 | struct page * page; | |
1325 | ||
1326 | page = virt_to_page(x); | |
1327 | ||
1328 | if (unlikely(PageCompound(page))) | |
1329 | page = page->first_page; | |
1330 | ||
1331 | ||
1332 | if (unlikely(PageError(page) && (s->flags & SLAB_STORE_USER))) | |
1333 | set_tracking(s, x, TRACK_FREE); | |
1334 | slab_free(s, page, x); | |
1335 | } | |
1336 | EXPORT_SYMBOL(kmem_cache_free); | |
1337 | ||
1338 | /* Figure out on which slab object the object resides */ | |
1339 | static struct page *get_object_page(const void *x) | |
1340 | { | |
1341 | struct page *page = virt_to_page(x); | |
1342 | ||
1343 | if (unlikely(PageCompound(page))) | |
1344 | page = page->first_page; | |
1345 | ||
1346 | if (!PageSlab(page)) | |
1347 | return NULL; | |
1348 | ||
1349 | return page; | |
1350 | } | |
1351 | ||
1352 | /* | |
1353 | * kmem_cache_open produces objects aligned at "size" and the first object | |
1354 | * is placed at offset 0 in the slab (We have no metainformation on the | |
1355 | * slab, all slabs are in essence "off slab"). | |
1356 | * | |
1357 | * In order to get the desired alignment one just needs to align the | |
1358 | * size. | |
1359 | * | |
1360 | * Notice that the allocation order determines the sizes of the per cpu | |
1361 | * caches. Each processor has always one slab available for allocations. | |
1362 | * Increasing the allocation order reduces the number of times that slabs | |
1363 | * must be moved on and off the partial lists and therefore may influence | |
1364 | * locking overhead. | |
1365 | * | |
1366 | * The offset is used to relocate the free list link in each object. It is | |
1367 | * therefore possible to move the free list link behind the object. This | |
1368 | * is necessary for RCU to work properly and also useful for debugging. | |
1369 | */ | |
1370 | ||
1371 | /* | |
1372 | * Mininum / Maximum order of slab pages. This influences locking overhead | |
1373 | * and slab fragmentation. A higher order reduces the number of partial slabs | |
1374 | * and increases the number of allocations possible without having to | |
1375 | * take the list_lock. | |
1376 | */ | |
1377 | static int slub_min_order; | |
1378 | static int slub_max_order = DEFAULT_MAX_ORDER; | |
1379 | ||
1380 | /* | |
1381 | * Minimum number of objects per slab. This is necessary in order to | |
1382 | * reduce locking overhead. Similar to the queue size in SLAB. | |
1383 | */ | |
1384 | static int slub_min_objects = DEFAULT_MIN_OBJECTS; | |
1385 | ||
1386 | /* | |
1387 | * Merge control. If this is set then no merging of slab caches will occur. | |
1388 | */ | |
1389 | static int slub_nomerge; | |
1390 | ||
1391 | /* | |
1392 | * Debug settings: | |
1393 | */ | |
1394 | static int slub_debug; | |
1395 | ||
1396 | static char *slub_debug_slabs; | |
1397 | ||
1398 | /* | |
1399 | * Calculate the order of allocation given an slab object size. | |
1400 | * | |
1401 | * The order of allocation has significant impact on other elements | |
1402 | * of the system. Generally order 0 allocations should be preferred | |
1403 | * since they do not cause fragmentation in the page allocator. Larger | |
1404 | * objects may have problems with order 0 because there may be too much | |
1405 | * space left unused in a slab. We go to a higher order if more than 1/8th | |
1406 | * of the slab would be wasted. | |
1407 | * | |
1408 | * In order to reach satisfactory performance we must ensure that | |
1409 | * a minimum number of objects is in one slab. Otherwise we may | |
1410 | * generate too much activity on the partial lists. This is less a | |
1411 | * concern for large slabs though. slub_max_order specifies the order | |
1412 | * where we begin to stop considering the number of objects in a slab. | |
1413 | * | |
1414 | * Higher order allocations also allow the placement of more objects | |
1415 | * in a slab and thereby reduce object handling overhead. If the user | |
1416 | * has requested a higher mininum order then we start with that one | |
1417 | * instead of zero. | |
1418 | */ | |
1419 | static int calculate_order(int size) | |
1420 | { | |
1421 | int order; | |
1422 | int rem; | |
1423 | ||
1424 | for (order = max(slub_min_order, fls(size - 1) - PAGE_SHIFT); | |
1425 | order < MAX_ORDER; order++) { | |
1426 | unsigned long slab_size = PAGE_SIZE << order; | |
1427 | ||
1428 | if (slub_max_order > order && | |
1429 | slab_size < slub_min_objects * size) | |
1430 | continue; | |
1431 | ||
1432 | if (slab_size < size) | |
1433 | continue; | |
1434 | ||
1435 | rem = slab_size % size; | |
1436 | ||
1437 | if (rem <= (PAGE_SIZE << order) / 8) | |
1438 | break; | |
1439 | ||
1440 | } | |
1441 | if (order >= MAX_ORDER) | |
1442 | return -E2BIG; | |
1443 | return order; | |
1444 | } | |
1445 | ||
1446 | /* | |
1447 | * Function to figure out which alignment to use from the | |
1448 | * various ways of specifying it. | |
1449 | */ | |
1450 | static unsigned long calculate_alignment(unsigned long flags, | |
1451 | unsigned long align, unsigned long size) | |
1452 | { | |
1453 | /* | |
1454 | * If the user wants hardware cache aligned objects then | |
1455 | * follow that suggestion if the object is sufficiently | |
1456 | * large. | |
1457 | * | |
1458 | * The hardware cache alignment cannot override the | |
1459 | * specified alignment though. If that is greater | |
1460 | * then use it. | |
1461 | */ | |
1462 | if ((flags & (SLAB_MUST_HWCACHE_ALIGN | SLAB_HWCACHE_ALIGN)) && | |
1463 | size > L1_CACHE_BYTES / 2) | |
1464 | return max_t(unsigned long, align, L1_CACHE_BYTES); | |
1465 | ||
1466 | if (align < ARCH_SLAB_MINALIGN) | |
1467 | return ARCH_SLAB_MINALIGN; | |
1468 | ||
1469 | return ALIGN(align, sizeof(void *)); | |
1470 | } | |
1471 | ||
1472 | static void init_kmem_cache_node(struct kmem_cache_node *n) | |
1473 | { | |
1474 | n->nr_partial = 0; | |
1475 | atomic_long_set(&n->nr_slabs, 0); | |
1476 | spin_lock_init(&n->list_lock); | |
1477 | INIT_LIST_HEAD(&n->partial); | |
1478 | } | |
1479 | ||
1480 | #ifdef CONFIG_NUMA | |
1481 | /* | |
1482 | * No kmalloc_node yet so do it by hand. We know that this is the first | |
1483 | * slab on the node for this slabcache. There are no concurrent accesses | |
1484 | * possible. | |
1485 | * | |
1486 | * Note that this function only works on the kmalloc_node_cache | |
1487 | * when allocating for the kmalloc_node_cache. | |
1488 | */ | |
1489 | static struct kmem_cache_node * __init early_kmem_cache_node_alloc(gfp_t gfpflags, | |
1490 | int node) | |
1491 | { | |
1492 | struct page *page; | |
1493 | struct kmem_cache_node *n; | |
1494 | ||
1495 | BUG_ON(kmalloc_caches->size < sizeof(struct kmem_cache_node)); | |
1496 | ||
1497 | page = new_slab(kmalloc_caches, gfpflags | GFP_THISNODE, node); | |
1498 | /* new_slab() disables interupts */ | |
1499 | local_irq_enable(); | |
1500 | ||
1501 | BUG_ON(!page); | |
1502 | n = page->freelist; | |
1503 | BUG_ON(!n); | |
1504 | page->freelist = get_freepointer(kmalloc_caches, n); | |
1505 | page->inuse++; | |
1506 | kmalloc_caches->node[node] = n; | |
1507 | init_object(kmalloc_caches, n, 1); | |
1508 | init_kmem_cache_node(n); | |
1509 | atomic_long_inc(&n->nr_slabs); | |
1510 | add_partial(kmalloc_caches, page); | |
1511 | return n; | |
1512 | } | |
1513 | ||
1514 | static void free_kmem_cache_nodes(struct kmem_cache *s) | |
1515 | { | |
1516 | int node; | |
1517 | ||
1518 | for_each_online_node(node) { | |
1519 | struct kmem_cache_node *n = s->node[node]; | |
1520 | if (n && n != &s->local_node) | |
1521 | kmem_cache_free(kmalloc_caches, n); | |
1522 | s->node[node] = NULL; | |
1523 | } | |
1524 | } | |
1525 | ||
1526 | static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) | |
1527 | { | |
1528 | int node; | |
1529 | int local_node; | |
1530 | ||
1531 | if (slab_state >= UP) | |
1532 | local_node = page_to_nid(virt_to_page(s)); | |
1533 | else | |
1534 | local_node = 0; | |
1535 | ||
1536 | for_each_online_node(node) { | |
1537 | struct kmem_cache_node *n; | |
1538 | ||
1539 | if (local_node == node) | |
1540 | n = &s->local_node; | |
1541 | else { | |
1542 | if (slab_state == DOWN) { | |
1543 | n = early_kmem_cache_node_alloc(gfpflags, | |
1544 | node); | |
1545 | continue; | |
1546 | } | |
1547 | n = kmem_cache_alloc_node(kmalloc_caches, | |
1548 | gfpflags, node); | |
1549 | ||
1550 | if (!n) { | |
1551 | free_kmem_cache_nodes(s); | |
1552 | return 0; | |
1553 | } | |
1554 | ||
1555 | } | |
1556 | s->node[node] = n; | |
1557 | init_kmem_cache_node(n); | |
1558 | } | |
1559 | return 1; | |
1560 | } | |
1561 | #else | |
1562 | static void free_kmem_cache_nodes(struct kmem_cache *s) | |
1563 | { | |
1564 | } | |
1565 | ||
1566 | static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags) | |
1567 | { | |
1568 | init_kmem_cache_node(&s->local_node); | |
1569 | return 1; | |
1570 | } | |
1571 | #endif | |
1572 | ||
1573 | /* | |
1574 | * calculate_sizes() determines the order and the distribution of data within | |
1575 | * a slab object. | |
1576 | */ | |
1577 | static int calculate_sizes(struct kmem_cache *s) | |
1578 | { | |
1579 | unsigned long flags = s->flags; | |
1580 | unsigned long size = s->objsize; | |
1581 | unsigned long align = s->align; | |
1582 | ||
1583 | /* | |
1584 | * Determine if we can poison the object itself. If the user of | |
1585 | * the slab may touch the object after free or before allocation | |
1586 | * then we should never poison the object itself. | |
1587 | */ | |
1588 | if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) && | |
1589 | !s->ctor && !s->dtor) | |
1590 | s->flags |= __OBJECT_POISON; | |
1591 | else | |
1592 | s->flags &= ~__OBJECT_POISON; | |
1593 | ||
1594 | /* | |
1595 | * Round up object size to the next word boundary. We can only | |
1596 | * place the free pointer at word boundaries and this determines | |
1597 | * the possible location of the free pointer. | |
1598 | */ | |
1599 | size = ALIGN(size, sizeof(void *)); | |
1600 | ||
1601 | /* | |
1602 | * If we are redzoning then check if there is some space between the | |
1603 | * end of the object and the free pointer. If not then add an | |
1604 | * additional word, so that we can establish a redzone between | |
1605 | * the object and the freepointer to be able to check for overwrites. | |
1606 | */ | |
1607 | if ((flags & SLAB_RED_ZONE) && size == s->objsize) | |
1608 | size += sizeof(void *); | |
1609 | ||
1610 | /* | |
1611 | * With that we have determined how much of the slab is in actual | |
1612 | * use by the object. This is the potential offset to the free | |
1613 | * pointer. | |
1614 | */ | |
1615 | s->inuse = size; | |
1616 | ||
1617 | if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) || | |
1618 | s->ctor || s->dtor)) { | |
1619 | /* | |
1620 | * Relocate free pointer after the object if it is not | |
1621 | * permitted to overwrite the first word of the object on | |
1622 | * kmem_cache_free. | |
1623 | * | |
1624 | * This is the case if we do RCU, have a constructor or | |
1625 | * destructor or are poisoning the objects. | |
1626 | */ | |
1627 | s->offset = size; | |
1628 | size += sizeof(void *); | |
1629 | } | |
1630 | ||
1631 | if (flags & SLAB_STORE_USER) | |
1632 | /* | |
1633 | * Need to store information about allocs and frees after | |
1634 | * the object. | |
1635 | */ | |
1636 | size += 2 * sizeof(struct track); | |
1637 | ||
1638 | if (flags & DEBUG_DEFAULT_FLAGS) | |
1639 | /* | |
1640 | * Add some empty padding so that we can catch | |
1641 | * overwrites from earlier objects rather than let | |
1642 | * tracking information or the free pointer be | |
1643 | * corrupted if an user writes before the start | |
1644 | * of the object. | |
1645 | */ | |
1646 | size += sizeof(void *); | |
1647 | /* | |
1648 | * Determine the alignment based on various parameters that the | |
1649 | * user specified (this is unecessarily complex due to the attempt | |
1650 | * to be compatible with SLAB. Should be cleaned up some day). | |
1651 | */ | |
1652 | align = calculate_alignment(flags, align, s->objsize); | |
1653 | ||
1654 | /* | |
1655 | * SLUB stores one object immediately after another beginning from | |
1656 | * offset 0. In order to align the objects we have to simply size | |
1657 | * each object to conform to the alignment. | |
1658 | */ | |
1659 | size = ALIGN(size, align); | |
1660 | s->size = size; | |
1661 | ||
1662 | s->order = calculate_order(size); | |
1663 | if (s->order < 0) | |
1664 | return 0; | |
1665 | ||
1666 | /* | |
1667 | * Determine the number of objects per slab | |
1668 | */ | |
1669 | s->objects = (PAGE_SIZE << s->order) / size; | |
1670 | ||
1671 | /* | |
1672 | * Verify that the number of objects is within permitted limits. | |
1673 | * The page->inuse field is only 16 bit wide! So we cannot have | |
1674 | * more than 64k objects per slab. | |
1675 | */ | |
1676 | if (!s->objects || s->objects > 65535) | |
1677 | return 0; | |
1678 | return 1; | |
1679 | ||
1680 | } | |
1681 | ||
1682 | static int __init finish_bootstrap(void) | |
1683 | { | |
1684 | struct list_head *h; | |
1685 | int err; | |
1686 | ||
1687 | slab_state = SYSFS; | |
1688 | ||
1689 | list_for_each(h, &slab_caches) { | |
1690 | struct kmem_cache *s = | |
1691 | container_of(h, struct kmem_cache, list); | |
1692 | ||
1693 | err = sysfs_slab_add(s); | |
1694 | BUG_ON(err); | |
1695 | } | |
1696 | return 0; | |
1697 | } | |
1698 | ||
1699 | static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, | |
1700 | const char *name, size_t size, | |
1701 | size_t align, unsigned long flags, | |
1702 | void (*ctor)(void *, struct kmem_cache *, unsigned long), | |
1703 | void (*dtor)(void *, struct kmem_cache *, unsigned long)) | |
1704 | { | |
1705 | memset(s, 0, kmem_size); | |
1706 | s->name = name; | |
1707 | s->ctor = ctor; | |
1708 | s->dtor = dtor; | |
1709 | s->objsize = size; | |
1710 | s->flags = flags; | |
1711 | s->align = align; | |
1712 | ||
1713 | BUG_ON(flags & SLUB_UNIMPLEMENTED); | |
1714 | ||
1715 | /* | |
1716 | * The page->offset field is only 16 bit wide. This is an offset | |
1717 | * in units of words from the beginning of an object. If the slab | |
1718 | * size is bigger then we cannot move the free pointer behind the | |
1719 | * object anymore. | |
1720 | * | |
1721 | * On 32 bit platforms the limit is 256k. On 64bit platforms | |
1722 | * the limit is 512k. | |
1723 | * | |
1724 | * Debugging or ctor/dtors may create a need to move the free | |
1725 | * pointer. Fail if this happens. | |
1726 | */ | |
1727 | if (s->size >= 65535 * sizeof(void *)) { | |
1728 | BUG_ON(flags & (SLAB_RED_ZONE | SLAB_POISON | | |
1729 | SLAB_STORE_USER | SLAB_DESTROY_BY_RCU)); | |
1730 | BUG_ON(ctor || dtor); | |
1731 | } | |
1732 | else | |
1733 | /* | |
1734 | * Enable debugging if selected on the kernel commandline. | |
1735 | */ | |
1736 | if (slub_debug && (!slub_debug_slabs || | |
1737 | strncmp(slub_debug_slabs, name, | |
1738 | strlen(slub_debug_slabs)) == 0)) | |
1739 | s->flags |= slub_debug; | |
1740 | ||
1741 | if (!calculate_sizes(s)) | |
1742 | goto error; | |
1743 | ||
1744 | s->refcount = 1; | |
1745 | #ifdef CONFIG_NUMA | |
1746 | s->defrag_ratio = 100; | |
1747 | #endif | |
1748 | ||
1749 | if (init_kmem_cache_nodes(s, gfpflags & ~SLUB_DMA)) | |
1750 | return 1; | |
1751 | error: | |
1752 | if (flags & SLAB_PANIC) | |
1753 | panic("Cannot create slab %s size=%lu realsize=%u " | |
1754 | "order=%u offset=%u flags=%lx\n", | |
1755 | s->name, (unsigned long)size, s->size, s->order, | |
1756 | s->offset, flags); | |
1757 | return 0; | |
1758 | } | |
1759 | EXPORT_SYMBOL(kmem_cache_open); | |
1760 | ||
1761 | /* | |
1762 | * Check if a given pointer is valid | |
1763 | */ | |
1764 | int kmem_ptr_validate(struct kmem_cache *s, const void *object) | |
1765 | { | |
1766 | struct page * page; | |
1767 | void *addr; | |
1768 | ||
1769 | page = get_object_page(object); | |
1770 | ||
1771 | if (!page || s != page->slab) | |
1772 | /* No slab or wrong slab */ | |
1773 | return 0; | |
1774 | ||
1775 | addr = page_address(page); | |
1776 | if (object < addr || object >= addr + s->objects * s->size) | |
1777 | /* Out of bounds */ | |
1778 | return 0; | |
1779 | ||
1780 | if ((object - addr) % s->size) | |
1781 | /* Improperly aligned */ | |
1782 | return 0; | |
1783 | ||
1784 | /* | |
1785 | * We could also check if the object is on the slabs freelist. | |
1786 | * But this would be too expensive and it seems that the main | |
1787 | * purpose of kmem_ptr_valid is to check if the object belongs | |
1788 | * to a certain slab. | |
1789 | */ | |
1790 | return 1; | |
1791 | } | |
1792 | EXPORT_SYMBOL(kmem_ptr_validate); | |
1793 | ||
1794 | /* | |
1795 | * Determine the size of a slab object | |
1796 | */ | |
1797 | unsigned int kmem_cache_size(struct kmem_cache *s) | |
1798 | { | |
1799 | return s->objsize; | |
1800 | } | |
1801 | EXPORT_SYMBOL(kmem_cache_size); | |
1802 | ||
1803 | const char *kmem_cache_name(struct kmem_cache *s) | |
1804 | { | |
1805 | return s->name; | |
1806 | } | |
1807 | EXPORT_SYMBOL(kmem_cache_name); | |
1808 | ||
1809 | /* | |
1810 | * Attempt to free all slabs on a node | |
1811 | */ | |
1812 | static int free_list(struct kmem_cache *s, struct kmem_cache_node *n, | |
1813 | struct list_head *list) | |
1814 | { | |
1815 | int slabs_inuse = 0; | |
1816 | unsigned long flags; | |
1817 | struct page *page, *h; | |
1818 | ||
1819 | spin_lock_irqsave(&n->list_lock, flags); | |
1820 | list_for_each_entry_safe(page, h, list, lru) | |
1821 | if (!page->inuse) { | |
1822 | list_del(&page->lru); | |
1823 | discard_slab(s, page); | |
1824 | } else | |
1825 | slabs_inuse++; | |
1826 | spin_unlock_irqrestore(&n->list_lock, flags); | |
1827 | return slabs_inuse; | |
1828 | } | |
1829 | ||
1830 | /* | |
1831 | * Release all resources used by slab cache | |
1832 | */ | |
1833 | static int kmem_cache_close(struct kmem_cache *s) | |
1834 | { | |
1835 | int node; | |
1836 | ||
1837 | flush_all(s); | |
1838 | ||
1839 | /* Attempt to free all objects */ | |
1840 | for_each_online_node(node) { | |
1841 | struct kmem_cache_node *n = get_node(s, node); | |
1842 | ||
1843 | free_list(s, n, &n->partial); | |
1844 | if (atomic_long_read(&n->nr_slabs)) | |
1845 | return 1; | |
1846 | } | |
1847 | free_kmem_cache_nodes(s); | |
1848 | return 0; | |
1849 | } | |
1850 | ||
1851 | /* | |
1852 | * Close a cache and release the kmem_cache structure | |
1853 | * (must be used for caches created using kmem_cache_create) | |
1854 | */ | |
1855 | void kmem_cache_destroy(struct kmem_cache *s) | |
1856 | { | |
1857 | down_write(&slub_lock); | |
1858 | s->refcount--; | |
1859 | if (!s->refcount) { | |
1860 | list_del(&s->list); | |
1861 | if (kmem_cache_close(s)) | |
1862 | WARN_ON(1); | |
1863 | sysfs_slab_remove(s); | |
1864 | kfree(s); | |
1865 | } | |
1866 | up_write(&slub_lock); | |
1867 | } | |
1868 | EXPORT_SYMBOL(kmem_cache_destroy); | |
1869 | ||
1870 | /******************************************************************** | |
1871 | * Kmalloc subsystem | |
1872 | *******************************************************************/ | |
1873 | ||
1874 | struct kmem_cache kmalloc_caches[KMALLOC_SHIFT_HIGH + 1] __cacheline_aligned; | |
1875 | EXPORT_SYMBOL(kmalloc_caches); | |
1876 | ||
1877 | #ifdef CONFIG_ZONE_DMA | |
1878 | static struct kmem_cache *kmalloc_caches_dma[KMALLOC_SHIFT_HIGH + 1]; | |
1879 | #endif | |
1880 | ||
1881 | static int __init setup_slub_min_order(char *str) | |
1882 | { | |
1883 | get_option (&str, &slub_min_order); | |
1884 | ||
1885 | return 1; | |
1886 | } | |
1887 | ||
1888 | __setup("slub_min_order=", setup_slub_min_order); | |
1889 | ||
1890 | static int __init setup_slub_max_order(char *str) | |
1891 | { | |
1892 | get_option (&str, &slub_max_order); | |
1893 | ||
1894 | return 1; | |
1895 | } | |
1896 | ||
1897 | __setup("slub_max_order=", setup_slub_max_order); | |
1898 | ||
1899 | static int __init setup_slub_min_objects(char *str) | |
1900 | { | |
1901 | get_option (&str, &slub_min_objects); | |
1902 | ||
1903 | return 1; | |
1904 | } | |
1905 | ||
1906 | __setup("slub_min_objects=", setup_slub_min_objects); | |
1907 | ||
1908 | static int __init setup_slub_nomerge(char *str) | |
1909 | { | |
1910 | slub_nomerge = 1; | |
1911 | return 1; | |
1912 | } | |
1913 | ||
1914 | __setup("slub_nomerge", setup_slub_nomerge); | |
1915 | ||
1916 | static int __init setup_slub_debug(char *str) | |
1917 | { | |
1918 | if (!str || *str != '=') | |
1919 | slub_debug = DEBUG_DEFAULT_FLAGS; | |
1920 | else { | |
1921 | str++; | |
1922 | if (*str == 0 || *str == ',') | |
1923 | slub_debug = DEBUG_DEFAULT_FLAGS; | |
1924 | else | |
1925 | for( ;*str && *str != ','; str++) | |
1926 | switch (*str) { | |
1927 | case 'f' : case 'F' : | |
1928 | slub_debug |= SLAB_DEBUG_FREE; | |
1929 | break; | |
1930 | case 'z' : case 'Z' : | |
1931 | slub_debug |= SLAB_RED_ZONE; | |
1932 | break; | |
1933 | case 'p' : case 'P' : | |
1934 | slub_debug |= SLAB_POISON; | |
1935 | break; | |
1936 | case 'u' : case 'U' : | |
1937 | slub_debug |= SLAB_STORE_USER; | |
1938 | break; | |
1939 | case 't' : case 'T' : | |
1940 | slub_debug |= SLAB_TRACE; | |
1941 | break; | |
1942 | default: | |
1943 | printk(KERN_ERR "slub_debug option '%c' " | |
1944 | "unknown. skipped\n",*str); | |
1945 | } | |
1946 | } | |
1947 | ||
1948 | if (*str == ',') | |
1949 | slub_debug_slabs = str + 1; | |
1950 | return 1; | |
1951 | } | |
1952 | ||
1953 | __setup("slub_debug", setup_slub_debug); | |
1954 | ||
1955 | static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s, | |
1956 | const char *name, int size, gfp_t gfp_flags) | |
1957 | { | |
1958 | unsigned int flags = 0; | |
1959 | ||
1960 | if (gfp_flags & SLUB_DMA) | |
1961 | flags = SLAB_CACHE_DMA; | |
1962 | ||
1963 | down_write(&slub_lock); | |
1964 | if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN, | |
1965 | flags, NULL, NULL)) | |
1966 | goto panic; | |
1967 | ||
1968 | list_add(&s->list, &slab_caches); | |
1969 | up_write(&slub_lock); | |
1970 | if (sysfs_slab_add(s)) | |
1971 | goto panic; | |
1972 | return s; | |
1973 | ||
1974 | panic: | |
1975 | panic("Creation of kmalloc slab %s size=%d failed.\n", name, size); | |
1976 | } | |
1977 | ||
1978 | static struct kmem_cache *get_slab(size_t size, gfp_t flags) | |
1979 | { | |
1980 | int index = kmalloc_index(size); | |
1981 | ||
1982 | if (!size) | |
1983 | return NULL; | |
1984 | ||
1985 | /* Allocation too large? */ | |
1986 | BUG_ON(index < 0); | |
1987 | ||
1988 | #ifdef CONFIG_ZONE_DMA | |
1989 | if ((flags & SLUB_DMA)) { | |
1990 | struct kmem_cache *s; | |
1991 | struct kmem_cache *x; | |
1992 | char *text; | |
1993 | size_t realsize; | |
1994 | ||
1995 | s = kmalloc_caches_dma[index]; | |
1996 | if (s) | |
1997 | return s; | |
1998 | ||
1999 | /* Dynamically create dma cache */ | |
2000 | x = kmalloc(kmem_size, flags & ~SLUB_DMA); | |
2001 | if (!x) | |
2002 | panic("Unable to allocate memory for dma cache\n"); | |
2003 | ||
2004 | if (index <= KMALLOC_SHIFT_HIGH) | |
2005 | realsize = 1 << index; | |
2006 | else { | |
2007 | if (index == 1) | |
2008 | realsize = 96; | |
2009 | else | |
2010 | realsize = 192; | |
2011 | } | |
2012 | ||
2013 | text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d", | |
2014 | (unsigned int)realsize); | |
2015 | s = create_kmalloc_cache(x, text, realsize, flags); | |
2016 | kmalloc_caches_dma[index] = s; | |
2017 | return s; | |
2018 | } | |
2019 | #endif | |
2020 | return &kmalloc_caches[index]; | |
2021 | } | |
2022 | ||
2023 | void *__kmalloc(size_t size, gfp_t flags) | |
2024 | { | |
2025 | struct kmem_cache *s = get_slab(size, flags); | |
2026 | ||
2027 | if (s) | |
2028 | return kmem_cache_alloc(s, flags); | |
2029 | return NULL; | |
2030 | } | |
2031 | EXPORT_SYMBOL(__kmalloc); | |
2032 | ||
2033 | #ifdef CONFIG_NUMA | |
2034 | void *__kmalloc_node(size_t size, gfp_t flags, int node) | |
2035 | { | |
2036 | struct kmem_cache *s = get_slab(size, flags); | |
2037 | ||
2038 | if (s) | |
2039 | return kmem_cache_alloc_node(s, flags, node); | |
2040 | return NULL; | |
2041 | } | |
2042 | EXPORT_SYMBOL(__kmalloc_node); | |
2043 | #endif | |
2044 | ||
2045 | size_t ksize(const void *object) | |
2046 | { | |
2047 | struct page *page = get_object_page(object); | |
2048 | struct kmem_cache *s; | |
2049 | ||
2050 | BUG_ON(!page); | |
2051 | s = page->slab; | |
2052 | BUG_ON(!s); | |
2053 | ||
2054 | /* | |
2055 | * Debugging requires use of the padding between object | |
2056 | * and whatever may come after it. | |
2057 | */ | |
2058 | if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) | |
2059 | return s->objsize; | |
2060 | ||
2061 | /* | |
2062 | * If we have the need to store the freelist pointer | |
2063 | * back there or track user information then we can | |
2064 | * only use the space before that information. | |
2065 | */ | |
2066 | if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) | |
2067 | return s->inuse; | |
2068 | ||
2069 | /* | |
2070 | * Else we can use all the padding etc for the allocation | |
2071 | */ | |
2072 | return s->size; | |
2073 | } | |
2074 | EXPORT_SYMBOL(ksize); | |
2075 | ||
2076 | void kfree(const void *x) | |
2077 | { | |
2078 | struct kmem_cache *s; | |
2079 | struct page *page; | |
2080 | ||
2081 | if (!x) | |
2082 | return; | |
2083 | ||
2084 | page = virt_to_page(x); | |
2085 | ||
2086 | if (unlikely(PageCompound(page))) | |
2087 | page = page->first_page; | |
2088 | ||
2089 | s = page->slab; | |
2090 | ||
2091 | if (unlikely(PageError(page) && (s->flags & SLAB_STORE_USER))) | |
2092 | set_tracking(s, (void *)x, TRACK_FREE); | |
2093 | slab_free(s, page, (void *)x); | |
2094 | } | |
2095 | EXPORT_SYMBOL(kfree); | |
2096 | ||
2097 | /** | |
2098 | * krealloc - reallocate memory. The contents will remain unchanged. | |
2099 | * | |
2100 | * @p: object to reallocate memory for. | |
2101 | * @new_size: how many bytes of memory are required. | |
2102 | * @flags: the type of memory to allocate. | |
2103 | * | |
2104 | * The contents of the object pointed to are preserved up to the | |
2105 | * lesser of the new and old sizes. If @p is %NULL, krealloc() | |
2106 | * behaves exactly like kmalloc(). If @size is 0 and @p is not a | |
2107 | * %NULL pointer, the object pointed to is freed. | |
2108 | */ | |
2109 | void *krealloc(const void *p, size_t new_size, gfp_t flags) | |
2110 | { | |
2111 | struct kmem_cache *new_cache; | |
2112 | void *ret; | |
2113 | struct page *page; | |
2114 | ||
2115 | if (unlikely(!p)) | |
2116 | return kmalloc(new_size, flags); | |
2117 | ||
2118 | if (unlikely(!new_size)) { | |
2119 | kfree(p); | |
2120 | return NULL; | |
2121 | } | |
2122 | ||
2123 | page = virt_to_page(p); | |
2124 | ||
2125 | if (unlikely(PageCompound(page))) | |
2126 | page = page->first_page; | |
2127 | ||
2128 | new_cache = get_slab(new_size, flags); | |
2129 | ||
2130 | /* | |
2131 | * If new size fits in the current cache, bail out. | |
2132 | */ | |
2133 | if (likely(page->slab == new_cache)) | |
2134 | return (void *)p; | |
2135 | ||
2136 | ret = kmalloc(new_size, flags); | |
2137 | if (ret) { | |
2138 | memcpy(ret, p, min(new_size, ksize(p))); | |
2139 | kfree(p); | |
2140 | } | |
2141 | return ret; | |
2142 | } | |
2143 | EXPORT_SYMBOL(krealloc); | |
2144 | ||
2145 | /******************************************************************** | |
2146 | * Basic setup of slabs | |
2147 | *******************************************************************/ | |
2148 | ||
2149 | void __init kmem_cache_init(void) | |
2150 | { | |
2151 | int i; | |
2152 | ||
2153 | #ifdef CONFIG_NUMA | |
2154 | /* | |
2155 | * Must first have the slab cache available for the allocations of the | |
2156 | * struct kmalloc_cache_node's. There is special bootstrap code in | |
2157 | * kmem_cache_open for slab_state == DOWN. | |
2158 | */ | |
2159 | create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node", | |
2160 | sizeof(struct kmem_cache_node), GFP_KERNEL); | |
2161 | #endif | |
2162 | ||
2163 | /* Able to allocate the per node structures */ | |
2164 | slab_state = PARTIAL; | |
2165 | ||
2166 | /* Caches that are not of the two-to-the-power-of size */ | |
2167 | create_kmalloc_cache(&kmalloc_caches[1], | |
2168 | "kmalloc-96", 96, GFP_KERNEL); | |
2169 | create_kmalloc_cache(&kmalloc_caches[2], | |
2170 | "kmalloc-192", 192, GFP_KERNEL); | |
2171 | ||
2172 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) | |
2173 | create_kmalloc_cache(&kmalloc_caches[i], | |
2174 | "kmalloc", 1 << i, GFP_KERNEL); | |
2175 | ||
2176 | slab_state = UP; | |
2177 | ||
2178 | /* Provide the correct kmalloc names now that the caches are up */ | |
2179 | for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) | |
2180 | kmalloc_caches[i]. name = | |
2181 | kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i); | |
2182 | ||
2183 | #ifdef CONFIG_SMP | |
2184 | register_cpu_notifier(&slab_notifier); | |
2185 | #endif | |
2186 | ||
2187 | if (nr_cpu_ids) /* Remove when nr_cpu_ids is fixed upstream ! */ | |
2188 | kmem_size = offsetof(struct kmem_cache, cpu_slab) | |
2189 | + nr_cpu_ids * sizeof(struct page *); | |
2190 | ||
2191 | printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," | |
2192 | " Processors=%d, Nodes=%d\n", | |
2193 | KMALLOC_SHIFT_HIGH, L1_CACHE_BYTES, | |
2194 | slub_min_order, slub_max_order, slub_min_objects, | |
2195 | nr_cpu_ids, nr_node_ids); | |
2196 | } | |
2197 | ||
2198 | /* | |
2199 | * Find a mergeable slab cache | |
2200 | */ | |
2201 | static int slab_unmergeable(struct kmem_cache *s) | |
2202 | { | |
2203 | if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE)) | |
2204 | return 1; | |
2205 | ||
2206 | if (s->ctor || s->dtor) | |
2207 | return 1; | |
2208 | ||
2209 | return 0; | |
2210 | } | |
2211 | ||
2212 | static struct kmem_cache *find_mergeable(size_t size, | |
2213 | size_t align, unsigned long flags, | |
2214 | void (*ctor)(void *, struct kmem_cache *, unsigned long), | |
2215 | void (*dtor)(void *, struct kmem_cache *, unsigned long)) | |
2216 | { | |
2217 | struct list_head *h; | |
2218 | ||
2219 | if (slub_nomerge || (flags & SLUB_NEVER_MERGE)) | |
2220 | return NULL; | |
2221 | ||
2222 | if (ctor || dtor) | |
2223 | return NULL; | |
2224 | ||
2225 | size = ALIGN(size, sizeof(void *)); | |
2226 | align = calculate_alignment(flags, align, size); | |
2227 | size = ALIGN(size, align); | |
2228 | ||
2229 | list_for_each(h, &slab_caches) { | |
2230 | struct kmem_cache *s = | |
2231 | container_of(h, struct kmem_cache, list); | |
2232 | ||
2233 | if (slab_unmergeable(s)) | |
2234 | continue; | |
2235 | ||
2236 | if (size > s->size) | |
2237 | continue; | |
2238 | ||
2239 | if (((flags | slub_debug) & SLUB_MERGE_SAME) != | |
2240 | (s->flags & SLUB_MERGE_SAME)) | |
2241 | continue; | |
2242 | /* | |
2243 | * Check if alignment is compatible. | |
2244 | * Courtesy of Adrian Drzewiecki | |
2245 | */ | |
2246 | if ((s->size & ~(align -1)) != s->size) | |
2247 | continue; | |
2248 | ||
2249 | if (s->size - size >= sizeof(void *)) | |
2250 | continue; | |
2251 | ||
2252 | return s; | |
2253 | } | |
2254 | return NULL; | |
2255 | } | |
2256 | ||
2257 | struct kmem_cache *kmem_cache_create(const char *name, size_t size, | |
2258 | size_t align, unsigned long flags, | |
2259 | void (*ctor)(void *, struct kmem_cache *, unsigned long), | |
2260 | void (*dtor)(void *, struct kmem_cache *, unsigned long)) | |
2261 | { | |
2262 | struct kmem_cache *s; | |
2263 | ||
2264 | down_write(&slub_lock); | |
2265 | s = find_mergeable(size, align, flags, dtor, ctor); | |
2266 | if (s) { | |
2267 | s->refcount++; | |
2268 | /* | |
2269 | * Adjust the object sizes so that we clear | |
2270 | * the complete object on kzalloc. | |
2271 | */ | |
2272 | s->objsize = max(s->objsize, (int)size); | |
2273 | s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *))); | |
2274 | if (sysfs_slab_alias(s, name)) | |
2275 | goto err; | |
2276 | } else { | |
2277 | s = kmalloc(kmem_size, GFP_KERNEL); | |
2278 | if (s && kmem_cache_open(s, GFP_KERNEL, name, | |
2279 | size, align, flags, ctor, dtor)) { | |
2280 | if (sysfs_slab_add(s)) { | |
2281 | kfree(s); | |
2282 | goto err; | |
2283 | } | |
2284 | list_add(&s->list, &slab_caches); | |
2285 | } else | |
2286 | kfree(s); | |
2287 | } | |
2288 | up_write(&slub_lock); | |
2289 | return s; | |
2290 | ||
2291 | err: | |
2292 | up_write(&slub_lock); | |
2293 | if (flags & SLAB_PANIC) | |
2294 | panic("Cannot create slabcache %s\n", name); | |
2295 | else | |
2296 | s = NULL; | |
2297 | return s; | |
2298 | } | |
2299 | EXPORT_SYMBOL(kmem_cache_create); | |
2300 | ||
2301 | void *kmem_cache_zalloc(struct kmem_cache *s, gfp_t flags) | |
2302 | { | |
2303 | void *x; | |
2304 | ||
2305 | x = kmem_cache_alloc(s, flags); | |
2306 | if (x) | |
2307 | memset(x, 0, s->objsize); | |
2308 | return x; | |
2309 | } | |
2310 | EXPORT_SYMBOL(kmem_cache_zalloc); | |
2311 | ||
2312 | #ifdef CONFIG_SMP | |
2313 | static void for_all_slabs(void (*func)(struct kmem_cache *, int), int cpu) | |
2314 | { | |
2315 | struct list_head *h; | |
2316 | ||
2317 | down_read(&slub_lock); | |
2318 | list_for_each(h, &slab_caches) { | |
2319 | struct kmem_cache *s = | |
2320 | container_of(h, struct kmem_cache, list); | |
2321 | ||
2322 | func(s, cpu); | |
2323 | } | |
2324 | up_read(&slub_lock); | |
2325 | } | |
2326 | ||
2327 | /* | |
2328 | * Use the cpu notifier to insure that the slab are flushed | |
2329 | * when necessary. | |
2330 | */ | |
2331 | static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb, | |
2332 | unsigned long action, void *hcpu) | |
2333 | { | |
2334 | long cpu = (long)hcpu; | |
2335 | ||
2336 | switch (action) { | |
2337 | case CPU_UP_CANCELED: | |
2338 | case CPU_DEAD: | |
2339 | for_all_slabs(__flush_cpu_slab, cpu); | |
2340 | break; | |
2341 | default: | |
2342 | break; | |
2343 | } | |
2344 | return NOTIFY_OK; | |
2345 | } | |
2346 | ||
2347 | static struct notifier_block __cpuinitdata slab_notifier = | |
2348 | { &slab_cpuup_callback, NULL, 0 }; | |
2349 | ||
2350 | #endif | |
2351 | ||
2352 | /*************************************************************** | |
2353 | * Compatiblility definitions | |
2354 | **************************************************************/ | |
2355 | ||
2356 | int kmem_cache_shrink(struct kmem_cache *s) | |
2357 | { | |
2358 | flush_all(s); | |
2359 | return 0; | |
2360 | } | |
2361 | EXPORT_SYMBOL(kmem_cache_shrink); | |
2362 | ||
2363 | #ifdef CONFIG_NUMA | |
2364 | ||
2365 | /***************************************************************** | |
2366 | * Generic reaper used to support the page allocator | |
2367 | * (the cpu slabs are reaped by a per slab workqueue). | |
2368 | * | |
2369 | * Maybe move this to the page allocator? | |
2370 | ****************************************************************/ | |
2371 | ||
2372 | static DEFINE_PER_CPU(unsigned long, reap_node); | |
2373 | ||
2374 | static void init_reap_node(int cpu) | |
2375 | { | |
2376 | int node; | |
2377 | ||
2378 | node = next_node(cpu_to_node(cpu), node_online_map); | |
2379 | if (node == MAX_NUMNODES) | |
2380 | node = first_node(node_online_map); | |
2381 | ||
2382 | __get_cpu_var(reap_node) = node; | |
2383 | } | |
2384 | ||
2385 | static void next_reap_node(void) | |
2386 | { | |
2387 | int node = __get_cpu_var(reap_node); | |
2388 | ||
2389 | /* | |
2390 | * Also drain per cpu pages on remote zones | |
2391 | */ | |
2392 | if (node != numa_node_id()) | |
2393 | drain_node_pages(node); | |
2394 | ||
2395 | node = next_node(node, node_online_map); | |
2396 | if (unlikely(node >= MAX_NUMNODES)) | |
2397 | node = first_node(node_online_map); | |
2398 | __get_cpu_var(reap_node) = node; | |
2399 | } | |
2400 | #else | |
2401 | #define init_reap_node(cpu) do { } while (0) | |
2402 | #define next_reap_node(void) do { } while (0) | |
2403 | #endif | |
2404 | ||
2405 | #define REAPTIMEOUT_CPUC (2*HZ) | |
2406 | ||
2407 | #ifdef CONFIG_SMP | |
2408 | static DEFINE_PER_CPU(struct delayed_work, reap_work); | |
2409 | ||
2410 | static void cache_reap(struct work_struct *unused) | |
2411 | { | |
2412 | next_reap_node(); | |
2413 | refresh_cpu_vm_stats(smp_processor_id()); | |
2414 | schedule_delayed_work(&__get_cpu_var(reap_work), | |
2415 | REAPTIMEOUT_CPUC); | |
2416 | } | |
2417 | ||
2418 | static void __devinit start_cpu_timer(int cpu) | |
2419 | { | |
2420 | struct delayed_work *reap_work = &per_cpu(reap_work, cpu); | |
2421 | ||
2422 | /* | |
2423 | * When this gets called from do_initcalls via cpucache_init(), | |
2424 | * init_workqueues() has already run, so keventd will be setup | |
2425 | * at that time. | |
2426 | */ | |
2427 | if (keventd_up() && reap_work->work.func == NULL) { | |
2428 | init_reap_node(cpu); | |
2429 | INIT_DELAYED_WORK(reap_work, cache_reap); | |
2430 | schedule_delayed_work_on(cpu, reap_work, HZ + 3 * cpu); | |
2431 | } | |
2432 | } | |
2433 | ||
2434 | static int __init cpucache_init(void) | |
2435 | { | |
2436 | int cpu; | |
2437 | ||
2438 | /* | |
2439 | * Register the timers that drain pcp pages and update vm statistics | |
2440 | */ | |
2441 | for_each_online_cpu(cpu) | |
2442 | start_cpu_timer(cpu); | |
2443 | return 0; | |
2444 | } | |
2445 | __initcall(cpucache_init); | |
2446 | #endif | |
2447 | ||
2448 | #ifdef SLUB_RESILIENCY_TEST | |
2449 | static unsigned long validate_slab_cache(struct kmem_cache *s); | |
2450 | ||
2451 | static void resiliency_test(void) | |
2452 | { | |
2453 | u8 *p; | |
2454 | ||
2455 | printk(KERN_ERR "SLUB resiliency testing\n"); | |
2456 | printk(KERN_ERR "-----------------------\n"); | |
2457 | printk(KERN_ERR "A. Corruption after allocation\n"); | |
2458 | ||
2459 | p = kzalloc(16, GFP_KERNEL); | |
2460 | p[16] = 0x12; | |
2461 | printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer" | |
2462 | " 0x12->0x%p\n\n", p + 16); | |
2463 | ||
2464 | validate_slab_cache(kmalloc_caches + 4); | |
2465 | ||
2466 | /* Hmmm... The next two are dangerous */ | |
2467 | p = kzalloc(32, GFP_KERNEL); | |
2468 | p[32 + sizeof(void *)] = 0x34; | |
2469 | printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab" | |
2470 | " 0x34 -> -0x%p\n", p); | |
2471 | printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n"); | |
2472 | ||
2473 | validate_slab_cache(kmalloc_caches + 5); | |
2474 | p = kzalloc(64, GFP_KERNEL); | |
2475 | p += 64 + (get_cycles() & 0xff) * sizeof(void *); | |
2476 | *p = 0x56; | |
2477 | printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n", | |
2478 | p); | |
2479 | printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n"); | |
2480 | validate_slab_cache(kmalloc_caches + 6); | |
2481 | ||
2482 | printk(KERN_ERR "\nB. Corruption after free\n"); | |
2483 | p = kzalloc(128, GFP_KERNEL); | |
2484 | kfree(p); | |
2485 | *p = 0x78; | |
2486 | printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p); | |
2487 | validate_slab_cache(kmalloc_caches + 7); | |
2488 | ||
2489 | p = kzalloc(256, GFP_KERNEL); | |
2490 | kfree(p); | |
2491 | p[50] = 0x9a; | |
2492 | printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", p); | |
2493 | validate_slab_cache(kmalloc_caches + 8); | |
2494 | ||
2495 | p = kzalloc(512, GFP_KERNEL); | |
2496 | kfree(p); | |
2497 | p[512] = 0xab; | |
2498 | printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p); | |
2499 | validate_slab_cache(kmalloc_caches + 9); | |
2500 | } | |
2501 | #else | |
2502 | static void resiliency_test(void) {}; | |
2503 | #endif | |
2504 | ||
2505 | /* | |
2506 | * These are not as efficient as kmalloc for the non debug case. | |
2507 | * We do not have the page struct available so we have to touch one | |
2508 | * cacheline in struct kmem_cache to check slab flags. | |
2509 | */ | |
2510 | void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller) | |
2511 | { | |
2512 | struct kmem_cache *s = get_slab(size, gfpflags); | |
2513 | void *object; | |
2514 | ||
2515 | if (!s) | |
2516 | return NULL; | |
2517 | ||
2518 | object = kmem_cache_alloc(s, gfpflags); | |
2519 | ||
2520 | if (object && (s->flags & SLAB_STORE_USER)) | |
2521 | set_track(s, object, TRACK_ALLOC, caller); | |
2522 | ||
2523 | return object; | |
2524 | } | |
2525 | ||
2526 | void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, | |
2527 | int node, void *caller) | |
2528 | { | |
2529 | struct kmem_cache *s = get_slab(size, gfpflags); | |
2530 | void *object; | |
2531 | ||
2532 | if (!s) | |
2533 | return NULL; | |
2534 | ||
2535 | object = kmem_cache_alloc_node(s, gfpflags, node); | |
2536 | ||
2537 | if (object && (s->flags & SLAB_STORE_USER)) | |
2538 | set_track(s, object, TRACK_ALLOC, caller); | |
2539 | ||
2540 | return object; | |
2541 | } | |
2542 | ||
2543 | #ifdef CONFIG_SYSFS | |
2544 | ||
2545 | static unsigned long count_partial(struct kmem_cache_node *n) | |
2546 | { | |
2547 | unsigned long flags; | |
2548 | unsigned long x = 0; | |
2549 | struct page *page; | |
2550 | ||
2551 | spin_lock_irqsave(&n->list_lock, flags); | |
2552 | list_for_each_entry(page, &n->partial, lru) | |
2553 | x += page->inuse; | |
2554 | spin_unlock_irqrestore(&n->list_lock, flags); | |
2555 | return x; | |
2556 | } | |
2557 | ||
2558 | enum slab_stat_type { | |
2559 | SL_FULL, | |
2560 | SL_PARTIAL, | |
2561 | SL_CPU, | |
2562 | SL_OBJECTS | |
2563 | }; | |
2564 | ||
2565 | #define SO_FULL (1 << SL_FULL) | |
2566 | #define SO_PARTIAL (1 << SL_PARTIAL) | |
2567 | #define SO_CPU (1 << SL_CPU) | |
2568 | #define SO_OBJECTS (1 << SL_OBJECTS) | |
2569 | ||
2570 | static unsigned long slab_objects(struct kmem_cache *s, | |
2571 | char *buf, unsigned long flags) | |
2572 | { | |
2573 | unsigned long total = 0; | |
2574 | int cpu; | |
2575 | int node; | |
2576 | int x; | |
2577 | unsigned long *nodes; | |
2578 | unsigned long *per_cpu; | |
2579 | ||
2580 | nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL); | |
2581 | per_cpu = nodes + nr_node_ids; | |
2582 | ||
2583 | for_each_possible_cpu(cpu) { | |
2584 | struct page *page = s->cpu_slab[cpu]; | |
2585 | int node; | |
2586 | ||
2587 | if (page) { | |
2588 | node = page_to_nid(page); | |
2589 | if (flags & SO_CPU) { | |
2590 | int x = 0; | |
2591 | ||
2592 | if (flags & SO_OBJECTS) | |
2593 | x = page->inuse; | |
2594 | else | |
2595 | x = 1; | |
2596 | total += x; | |
2597 | nodes[node] += x; | |
2598 | } | |
2599 | per_cpu[node]++; | |
2600 | } | |
2601 | } | |
2602 | ||
2603 | for_each_online_node(node) { | |
2604 | struct kmem_cache_node *n = get_node(s, node); | |
2605 | ||
2606 | if (flags & SO_PARTIAL) { | |
2607 | if (flags & SO_OBJECTS) | |
2608 | x = count_partial(n); | |
2609 | else | |
2610 | x = n->nr_partial; | |
2611 | total += x; | |
2612 | nodes[node] += x; | |
2613 | } | |
2614 | ||
2615 | if (flags & SO_FULL) { | |
2616 | int full_slabs = atomic_read(&n->nr_slabs) | |
2617 | - per_cpu[node] | |
2618 | - n->nr_partial; | |
2619 | ||
2620 | if (flags & SO_OBJECTS) | |
2621 | x = full_slabs * s->objects; | |
2622 | else | |
2623 | x = full_slabs; | |
2624 | total += x; | |
2625 | nodes[node] += x; | |
2626 | } | |
2627 | } | |
2628 | ||
2629 | x = sprintf(buf, "%lu", total); | |
2630 | #ifdef CONFIG_NUMA | |
2631 | for_each_online_node(node) | |
2632 | if (nodes[node]) | |
2633 | x += sprintf(buf + x, " N%d=%lu", | |
2634 | node, nodes[node]); | |
2635 | #endif | |
2636 | kfree(nodes); | |
2637 | return x + sprintf(buf + x, "\n"); | |
2638 | } | |
2639 | ||
2640 | static int any_slab_objects(struct kmem_cache *s) | |
2641 | { | |
2642 | int node; | |
2643 | int cpu; | |
2644 | ||
2645 | for_each_possible_cpu(cpu) | |
2646 | if (s->cpu_slab[cpu]) | |
2647 | return 1; | |
2648 | ||
2649 | for_each_node(node) { | |
2650 | struct kmem_cache_node *n = get_node(s, node); | |
2651 | ||
2652 | if (n->nr_partial || atomic_read(&n->nr_slabs)) | |
2653 | return 1; | |
2654 | } | |
2655 | return 0; | |
2656 | } | |
2657 | ||
2658 | #define to_slab_attr(n) container_of(n, struct slab_attribute, attr) | |
2659 | #define to_slab(n) container_of(n, struct kmem_cache, kobj); | |
2660 | ||
2661 | struct slab_attribute { | |
2662 | struct attribute attr; | |
2663 | ssize_t (*show)(struct kmem_cache *s, char *buf); | |
2664 | ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count); | |
2665 | }; | |
2666 | ||
2667 | #define SLAB_ATTR_RO(_name) \ | |
2668 | static struct slab_attribute _name##_attr = __ATTR_RO(_name) | |
2669 | ||
2670 | #define SLAB_ATTR(_name) \ | |
2671 | static struct slab_attribute _name##_attr = \ | |
2672 | __ATTR(_name, 0644, _name##_show, _name##_store) | |
2673 | ||
2674 | ||
2675 | static ssize_t slab_size_show(struct kmem_cache *s, char *buf) | |
2676 | { | |
2677 | return sprintf(buf, "%d\n", s->size); | |
2678 | } | |
2679 | SLAB_ATTR_RO(slab_size); | |
2680 | ||
2681 | static ssize_t align_show(struct kmem_cache *s, char *buf) | |
2682 | { | |
2683 | return sprintf(buf, "%d\n", s->align); | |
2684 | } | |
2685 | SLAB_ATTR_RO(align); | |
2686 | ||
2687 | static ssize_t object_size_show(struct kmem_cache *s, char *buf) | |
2688 | { | |
2689 | return sprintf(buf, "%d\n", s->objsize); | |
2690 | } | |
2691 | SLAB_ATTR_RO(object_size); | |
2692 | ||
2693 | static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf) | |
2694 | { | |
2695 | return sprintf(buf, "%d\n", s->objects); | |
2696 | } | |
2697 | SLAB_ATTR_RO(objs_per_slab); | |
2698 | ||
2699 | static ssize_t order_show(struct kmem_cache *s, char *buf) | |
2700 | { | |
2701 | return sprintf(buf, "%d\n", s->order); | |
2702 | } | |
2703 | SLAB_ATTR_RO(order); | |
2704 | ||
2705 | static ssize_t ctor_show(struct kmem_cache *s, char *buf) | |
2706 | { | |
2707 | if (s->ctor) { | |
2708 | int n = sprint_symbol(buf, (unsigned long)s->ctor); | |
2709 | ||
2710 | return n + sprintf(buf + n, "\n"); | |
2711 | } | |
2712 | return 0; | |
2713 | } | |
2714 | SLAB_ATTR_RO(ctor); | |
2715 | ||
2716 | static ssize_t dtor_show(struct kmem_cache *s, char *buf) | |
2717 | { | |
2718 | if (s->dtor) { | |
2719 | int n = sprint_symbol(buf, (unsigned long)s->dtor); | |
2720 | ||
2721 | return n + sprintf(buf + n, "\n"); | |
2722 | } | |
2723 | return 0; | |
2724 | } | |
2725 | SLAB_ATTR_RO(dtor); | |
2726 | ||
2727 | static ssize_t aliases_show(struct kmem_cache *s, char *buf) | |
2728 | { | |
2729 | return sprintf(buf, "%d\n", s->refcount - 1); | |
2730 | } | |
2731 | SLAB_ATTR_RO(aliases); | |
2732 | ||
2733 | static ssize_t slabs_show(struct kmem_cache *s, char *buf) | |
2734 | { | |
2735 | return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU); | |
2736 | } | |
2737 | SLAB_ATTR_RO(slabs); | |
2738 | ||
2739 | static ssize_t partial_show(struct kmem_cache *s, char *buf) | |
2740 | { | |
2741 | return slab_objects(s, buf, SO_PARTIAL); | |
2742 | } | |
2743 | SLAB_ATTR_RO(partial); | |
2744 | ||
2745 | static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf) | |
2746 | { | |
2747 | return slab_objects(s, buf, SO_CPU); | |
2748 | } | |
2749 | SLAB_ATTR_RO(cpu_slabs); | |
2750 | ||
2751 | static ssize_t objects_show(struct kmem_cache *s, char *buf) | |
2752 | { | |
2753 | return slab_objects(s, buf, SO_FULL|SO_PARTIAL|SO_CPU|SO_OBJECTS); | |
2754 | } | |
2755 | SLAB_ATTR_RO(objects); | |
2756 | ||
2757 | static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf) | |
2758 | { | |
2759 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE)); | |
2760 | } | |
2761 | ||
2762 | static ssize_t sanity_checks_store(struct kmem_cache *s, | |
2763 | const char *buf, size_t length) | |
2764 | { | |
2765 | s->flags &= ~SLAB_DEBUG_FREE; | |
2766 | if (buf[0] == '1') | |
2767 | s->flags |= SLAB_DEBUG_FREE; | |
2768 | return length; | |
2769 | } | |
2770 | SLAB_ATTR(sanity_checks); | |
2771 | ||
2772 | static ssize_t trace_show(struct kmem_cache *s, char *buf) | |
2773 | { | |
2774 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE)); | |
2775 | } | |
2776 | ||
2777 | static ssize_t trace_store(struct kmem_cache *s, const char *buf, | |
2778 | size_t length) | |
2779 | { | |
2780 | s->flags &= ~SLAB_TRACE; | |
2781 | if (buf[0] == '1') | |
2782 | s->flags |= SLAB_TRACE; | |
2783 | return length; | |
2784 | } | |
2785 | SLAB_ATTR(trace); | |
2786 | ||
2787 | static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) | |
2788 | { | |
2789 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); | |
2790 | } | |
2791 | ||
2792 | static ssize_t reclaim_account_store(struct kmem_cache *s, | |
2793 | const char *buf, size_t length) | |
2794 | { | |
2795 | s->flags &= ~SLAB_RECLAIM_ACCOUNT; | |
2796 | if (buf[0] == '1') | |
2797 | s->flags |= SLAB_RECLAIM_ACCOUNT; | |
2798 | return length; | |
2799 | } | |
2800 | SLAB_ATTR(reclaim_account); | |
2801 | ||
2802 | static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf) | |
2803 | { | |
2804 | return sprintf(buf, "%d\n", !!(s->flags & | |
2805 | (SLAB_HWCACHE_ALIGN|SLAB_MUST_HWCACHE_ALIGN))); | |
2806 | } | |
2807 | SLAB_ATTR_RO(hwcache_align); | |
2808 | ||
2809 | #ifdef CONFIG_ZONE_DMA | |
2810 | static ssize_t cache_dma_show(struct kmem_cache *s, char *buf) | |
2811 | { | |
2812 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA)); | |
2813 | } | |
2814 | SLAB_ATTR_RO(cache_dma); | |
2815 | #endif | |
2816 | ||
2817 | static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) | |
2818 | { | |
2819 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU)); | |
2820 | } | |
2821 | SLAB_ATTR_RO(destroy_by_rcu); | |
2822 | ||
2823 | static ssize_t red_zone_show(struct kmem_cache *s, char *buf) | |
2824 | { | |
2825 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE)); | |
2826 | } | |
2827 | ||
2828 | static ssize_t red_zone_store(struct kmem_cache *s, | |
2829 | const char *buf, size_t length) | |
2830 | { | |
2831 | if (any_slab_objects(s)) | |
2832 | return -EBUSY; | |
2833 | ||
2834 | s->flags &= ~SLAB_RED_ZONE; | |
2835 | if (buf[0] == '1') | |
2836 | s->flags |= SLAB_RED_ZONE; | |
2837 | calculate_sizes(s); | |
2838 | return length; | |
2839 | } | |
2840 | SLAB_ATTR(red_zone); | |
2841 | ||
2842 | static ssize_t poison_show(struct kmem_cache *s, char *buf) | |
2843 | { | |
2844 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON)); | |
2845 | } | |
2846 | ||
2847 | static ssize_t poison_store(struct kmem_cache *s, | |
2848 | const char *buf, size_t length) | |
2849 | { | |
2850 | if (any_slab_objects(s)) | |
2851 | return -EBUSY; | |
2852 | ||
2853 | s->flags &= ~SLAB_POISON; | |
2854 | if (buf[0] == '1') | |
2855 | s->flags |= SLAB_POISON; | |
2856 | calculate_sizes(s); | |
2857 | return length; | |
2858 | } | |
2859 | SLAB_ATTR(poison); | |
2860 | ||
2861 | static ssize_t store_user_show(struct kmem_cache *s, char *buf) | |
2862 | { | |
2863 | return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER)); | |
2864 | } | |
2865 | ||
2866 | static ssize_t store_user_store(struct kmem_cache *s, | |
2867 | const char *buf, size_t length) | |
2868 | { | |
2869 | if (any_slab_objects(s)) | |
2870 | return -EBUSY; | |
2871 | ||
2872 | s->flags &= ~SLAB_STORE_USER; | |
2873 | if (buf[0] == '1') | |
2874 | s->flags |= SLAB_STORE_USER; | |
2875 | calculate_sizes(s); | |
2876 | return length; | |
2877 | } | |
2878 | SLAB_ATTR(store_user); | |
2879 | ||
2880 | #ifdef CONFIG_NUMA | |
2881 | static ssize_t defrag_ratio_show(struct kmem_cache *s, char *buf) | |
2882 | { | |
2883 | return sprintf(buf, "%d\n", s->defrag_ratio / 10); | |
2884 | } | |
2885 | ||
2886 | static ssize_t defrag_ratio_store(struct kmem_cache *s, | |
2887 | const char *buf, size_t length) | |
2888 | { | |
2889 | int n = simple_strtoul(buf, NULL, 10); | |
2890 | ||
2891 | if (n < 100) | |
2892 | s->defrag_ratio = n * 10; | |
2893 | return length; | |
2894 | } | |
2895 | SLAB_ATTR(defrag_ratio); | |
2896 | #endif | |
2897 | ||
2898 | static struct attribute * slab_attrs[] = { | |
2899 | &slab_size_attr.attr, | |
2900 | &object_size_attr.attr, | |
2901 | &objs_per_slab_attr.attr, | |
2902 | &order_attr.attr, | |
2903 | &objects_attr.attr, | |
2904 | &slabs_attr.attr, | |
2905 | &partial_attr.attr, | |
2906 | &cpu_slabs_attr.attr, | |
2907 | &ctor_attr.attr, | |
2908 | &dtor_attr.attr, | |
2909 | &aliases_attr.attr, | |
2910 | &align_attr.attr, | |
2911 | &sanity_checks_attr.attr, | |
2912 | &trace_attr.attr, | |
2913 | &hwcache_align_attr.attr, | |
2914 | &reclaim_account_attr.attr, | |
2915 | &destroy_by_rcu_attr.attr, | |
2916 | &red_zone_attr.attr, | |
2917 | &poison_attr.attr, | |
2918 | &store_user_attr.attr, | |
2919 | #ifdef CONFIG_ZONE_DMA | |
2920 | &cache_dma_attr.attr, | |
2921 | #endif | |
2922 | #ifdef CONFIG_NUMA | |
2923 | &defrag_ratio_attr.attr, | |
2924 | #endif | |
2925 | NULL | |
2926 | }; | |
2927 | ||
2928 | static struct attribute_group slab_attr_group = { | |
2929 | .attrs = slab_attrs, | |
2930 | }; | |
2931 | ||
2932 | static ssize_t slab_attr_show(struct kobject *kobj, | |
2933 | struct attribute *attr, | |
2934 | char *buf) | |
2935 | { | |
2936 | struct slab_attribute *attribute; | |
2937 | struct kmem_cache *s; | |
2938 | int err; | |
2939 | ||
2940 | attribute = to_slab_attr(attr); | |
2941 | s = to_slab(kobj); | |
2942 | ||
2943 | if (!attribute->show) | |
2944 | return -EIO; | |
2945 | ||
2946 | err = attribute->show(s, buf); | |
2947 | ||
2948 | return err; | |
2949 | } | |
2950 | ||
2951 | static ssize_t slab_attr_store(struct kobject *kobj, | |
2952 | struct attribute *attr, | |
2953 | const char *buf, size_t len) | |
2954 | { | |
2955 | struct slab_attribute *attribute; | |
2956 | struct kmem_cache *s; | |
2957 | int err; | |
2958 | ||
2959 | attribute = to_slab_attr(attr); | |
2960 | s = to_slab(kobj); | |
2961 | ||
2962 | if (!attribute->store) | |
2963 | return -EIO; | |
2964 | ||
2965 | err = attribute->store(s, buf, len); | |
2966 | ||
2967 | return err; | |
2968 | } | |
2969 | ||
2970 | static struct sysfs_ops slab_sysfs_ops = { | |
2971 | .show = slab_attr_show, | |
2972 | .store = slab_attr_store, | |
2973 | }; | |
2974 | ||
2975 | static struct kobj_type slab_ktype = { | |
2976 | .sysfs_ops = &slab_sysfs_ops, | |
2977 | }; | |
2978 | ||
2979 | static int uevent_filter(struct kset *kset, struct kobject *kobj) | |
2980 | { | |
2981 | struct kobj_type *ktype = get_ktype(kobj); | |
2982 | ||
2983 | if (ktype == &slab_ktype) | |
2984 | return 1; | |
2985 | return 0; | |
2986 | } | |
2987 | ||
2988 | static struct kset_uevent_ops slab_uevent_ops = { | |
2989 | .filter = uevent_filter, | |
2990 | }; | |
2991 | ||
2992 | decl_subsys(slab, &slab_ktype, &slab_uevent_ops); | |
2993 | ||
2994 | #define ID_STR_LENGTH 64 | |
2995 | ||
2996 | /* Create a unique string id for a slab cache: | |
2997 | * format | |
2998 | * :[flags-]size:[memory address of kmemcache] | |
2999 | */ | |
3000 | static char *create_unique_id(struct kmem_cache *s) | |
3001 | { | |
3002 | char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL); | |
3003 | char *p = name; | |
3004 | ||
3005 | BUG_ON(!name); | |
3006 | ||
3007 | *p++ = ':'; | |
3008 | /* | |
3009 | * First flags affecting slabcache operations. We will only | |
3010 | * get here for aliasable slabs so we do not need to support | |
3011 | * too many flags. The flags here must cover all flags that | |
3012 | * are matched during merging to guarantee that the id is | |
3013 | * unique. | |
3014 | */ | |
3015 | if (s->flags & SLAB_CACHE_DMA) | |
3016 | *p++ = 'd'; | |
3017 | if (s->flags & SLAB_RECLAIM_ACCOUNT) | |
3018 | *p++ = 'a'; | |
3019 | if (s->flags & SLAB_DEBUG_FREE) | |
3020 | *p++ = 'F'; | |
3021 | if (p != name + 1) | |
3022 | *p++ = '-'; | |
3023 | p += sprintf(p, "%07d", s->size); | |
3024 | BUG_ON(p > name + ID_STR_LENGTH - 1); | |
3025 | return name; | |
3026 | } | |
3027 | ||
3028 | static int sysfs_slab_add(struct kmem_cache *s) | |
3029 | { | |
3030 | int err; | |
3031 | const char *name; | |
3032 | int unmergeable; | |
3033 | ||
3034 | if (slab_state < SYSFS) | |
3035 | /* Defer until later */ | |
3036 | return 0; | |
3037 | ||
3038 | unmergeable = slab_unmergeable(s); | |
3039 | if (unmergeable) { | |
3040 | /* | |
3041 | * Slabcache can never be merged so we can use the name proper. | |
3042 | * This is typically the case for debug situations. In that | |
3043 | * case we can catch duplicate names easily. | |
3044 | */ | |
3045 | sysfs_remove_link(&slab_subsys.kset.kobj, s->name); | |
3046 | name = s->name; | |
3047 | } else { | |
3048 | /* | |
3049 | * Create a unique name for the slab as a target | |
3050 | * for the symlinks. | |
3051 | */ | |
3052 | name = create_unique_id(s); | |
3053 | } | |
3054 | ||
3055 | kobj_set_kset_s(s, slab_subsys); | |
3056 | kobject_set_name(&s->kobj, name); | |
3057 | kobject_init(&s->kobj); | |
3058 | err = kobject_add(&s->kobj); | |
3059 | if (err) | |
3060 | return err; | |
3061 | ||
3062 | err = sysfs_create_group(&s->kobj, &slab_attr_group); | |
3063 | if (err) | |
3064 | return err; | |
3065 | kobject_uevent(&s->kobj, KOBJ_ADD); | |
3066 | if (!unmergeable) { | |
3067 | /* Setup first alias */ | |
3068 | sysfs_slab_alias(s, s->name); | |
3069 | kfree(name); | |
3070 | } | |
3071 | return 0; | |
3072 | } | |
3073 | ||
3074 | static void sysfs_slab_remove(struct kmem_cache *s) | |
3075 | { | |
3076 | kobject_uevent(&s->kobj, KOBJ_REMOVE); | |
3077 | kobject_del(&s->kobj); | |
3078 | } | |
3079 | ||
3080 | /* | |
3081 | * Need to buffer aliases during bootup until sysfs becomes | |
3082 | * available lest we loose that information. | |
3083 | */ | |
3084 | struct saved_alias { | |
3085 | struct kmem_cache *s; | |
3086 | const char *name; | |
3087 | struct saved_alias *next; | |
3088 | }; | |
3089 | ||
3090 | struct saved_alias *alias_list; | |
3091 | ||
3092 | static int sysfs_slab_alias(struct kmem_cache *s, const char *name) | |
3093 | { | |
3094 | struct saved_alias *al; | |
3095 | ||
3096 | if (slab_state == SYSFS) { | |
3097 | /* | |
3098 | * If we have a leftover link then remove it. | |
3099 | */ | |
3100 | sysfs_remove_link(&slab_subsys.kset.kobj, name); | |
3101 | return sysfs_create_link(&slab_subsys.kset.kobj, | |
3102 | &s->kobj, name); | |
3103 | } | |
3104 | ||
3105 | al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL); | |
3106 | if (!al) | |
3107 | return -ENOMEM; | |
3108 | ||
3109 | al->s = s; | |
3110 | al->name = name; | |
3111 | al->next = alias_list; | |
3112 | alias_list = al; | |
3113 | return 0; | |
3114 | } | |
3115 | ||
3116 | static int __init slab_sysfs_init(void) | |
3117 | { | |
3118 | int err; | |
3119 | ||
3120 | err = subsystem_register(&slab_subsys); | |
3121 | if (err) { | |
3122 | printk(KERN_ERR "Cannot register slab subsystem.\n"); | |
3123 | return -ENOSYS; | |
3124 | } | |
3125 | ||
3126 | finish_bootstrap(); | |
3127 | ||
3128 | while (alias_list) { | |
3129 | struct saved_alias *al = alias_list; | |
3130 | ||
3131 | alias_list = alias_list->next; | |
3132 | err = sysfs_slab_alias(al->s, al->name); | |
3133 | BUG_ON(err); | |
3134 | kfree(al); | |
3135 | } | |
3136 | ||
3137 | resiliency_test(); | |
3138 | return 0; | |
3139 | } | |
3140 | ||
3141 | __initcall(slab_sysfs_init); | |
3142 | #else | |
3143 | __initcall(finish_bootstrap); | |
3144 | #endif |