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1 #ifndef MM_SLAB_H
2 #define MM_SLAB_H
3 /*
4 * Internal slab definitions
5 */
6
7 #ifdef CONFIG_SLOB
8 /*
9 * Common fields provided in kmem_cache by all slab allocators
10 * This struct is either used directly by the allocator (SLOB)
11 * or the allocator must include definitions for all fields
12 * provided in kmem_cache_common in their definition of kmem_cache.
13 *
14 * Once we can do anonymous structs (C11 standard) we could put a
15 * anonymous struct definition in these allocators so that the
16 * separate allocations in the kmem_cache structure of SLAB and
17 * SLUB is no longer needed.
18 */
19 struct kmem_cache {
20 unsigned int object_size;/* The original size of the object */
21 unsigned int size; /* The aligned/padded/added on size */
22 unsigned int align; /* Alignment as calculated */
23 unsigned long flags; /* Active flags on the slab */
24 const char *name; /* Slab name for sysfs */
25 int refcount; /* Use counter */
26 void (*ctor)(void *); /* Called on object slot creation */
27 struct list_head list; /* List of all slab caches on the system */
28 };
29
30 #endif /* CONFIG_SLOB */
31
32 #ifdef CONFIG_SLAB
33 #include <linux/slab_def.h>
34 #endif
35
36 #ifdef CONFIG_SLUB
37 #include <linux/slub_def.h>
38 #endif
39
40 #include <linux/memcontrol.h>
41 #include <linux/fault-inject.h>
42 #include <linux/kmemcheck.h>
43 #include <linux/kasan.h>
44 #include <linux/kmemleak.h>
45
46 /*
47 * State of the slab allocator.
48 *
49 * This is used to describe the states of the allocator during bootup.
50 * Allocators use this to gradually bootstrap themselves. Most allocators
51 * have the problem that the structures used for managing slab caches are
52 * allocated from slab caches themselves.
53 */
54 enum slab_state {
55 DOWN, /* No slab functionality yet */
56 PARTIAL, /* SLUB: kmem_cache_node available */
57 PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */
58 UP, /* Slab caches usable but not all extras yet */
59 FULL /* Everything is working */
60 };
61
62 extern enum slab_state slab_state;
63
64 /* The slab cache mutex protects the management structures during changes */
65 extern struct mutex slab_mutex;
66
67 /* The list of all slab caches on the system */
68 extern struct list_head slab_caches;
69
70 /* The slab cache that manages slab cache information */
71 extern struct kmem_cache *kmem_cache;
72
73 unsigned long calculate_alignment(unsigned long flags,
74 unsigned long align, unsigned long size);
75
76 #ifndef CONFIG_SLOB
77 /* Kmalloc array related functions */
78 void setup_kmalloc_cache_index_table(void);
79 void create_kmalloc_caches(unsigned long);
80
81 /* Find the kmalloc slab corresponding for a certain size */
82 struct kmem_cache *kmalloc_slab(size_t, gfp_t);
83 #endif
84
85
86 /* Functions provided by the slab allocators */
87 extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
88
89 extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
90 unsigned long flags);
91 extern void create_boot_cache(struct kmem_cache *, const char *name,
92 size_t size, unsigned long flags);
93
94 int slab_unmergeable(struct kmem_cache *s);
95 struct kmem_cache *find_mergeable(size_t size, size_t align,
96 unsigned long flags, const char *name, void (*ctor)(void *));
97 #ifndef CONFIG_SLOB
98 struct kmem_cache *
99 __kmem_cache_alias(const char *name, size_t size, size_t align,
100 unsigned long flags, void (*ctor)(void *));
101
102 unsigned long kmem_cache_flags(unsigned long object_size,
103 unsigned long flags, const char *name,
104 void (*ctor)(void *));
105 #else
106 static inline struct kmem_cache *
107 __kmem_cache_alias(const char *name, size_t size, size_t align,
108 unsigned long flags, void (*ctor)(void *))
109 { return NULL; }
110
111 static inline unsigned long kmem_cache_flags(unsigned long object_size,
112 unsigned long flags, const char *name,
113 void (*ctor)(void *))
114 {
115 return flags;
116 }
117 #endif
118
119
120 /* Legal flag mask for kmem_cache_create(), for various configurations */
121 #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
122 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
123
124 #if defined(CONFIG_DEBUG_SLAB)
125 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
126 #elif defined(CONFIG_SLUB_DEBUG)
127 #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
128 SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
129 #else
130 #define SLAB_DEBUG_FLAGS (0)
131 #endif
132
133 #if defined(CONFIG_SLAB)
134 #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
135 SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
136 SLAB_NOTRACK | SLAB_ACCOUNT)
137 #elif defined(CONFIG_SLUB)
138 #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
139 SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT)
140 #else
141 #define SLAB_CACHE_FLAGS (0)
142 #endif
143
144 #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
145
146 int __kmem_cache_shutdown(struct kmem_cache *);
147 void __kmem_cache_release(struct kmem_cache *);
148 int __kmem_cache_shrink(struct kmem_cache *, bool);
149 void slab_kmem_cache_release(struct kmem_cache *);
150
151 struct seq_file;
152 struct file;
153
154 struct slabinfo {
155 unsigned long active_objs;
156 unsigned long num_objs;
157 unsigned long active_slabs;
158 unsigned long num_slabs;
159 unsigned long shared_avail;
160 unsigned int limit;
161 unsigned int batchcount;
162 unsigned int shared;
163 unsigned int objects_per_slab;
164 unsigned int cache_order;
165 };
166
167 void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
168 void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
169 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
170 size_t count, loff_t *ppos);
171
172 /*
173 * Generic implementation of bulk operations
174 * These are useful for situations in which the allocator cannot
175 * perform optimizations. In that case segments of the object listed
176 * may be allocated or freed using these operations.
177 */
178 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
179 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
180
181 #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
182 /*
183 * Iterate over all memcg caches of the given root cache. The caller must hold
184 * slab_mutex.
185 */
186 #define for_each_memcg_cache(iter, root) \
187 list_for_each_entry(iter, &(root)->memcg_params.list, \
188 memcg_params.list)
189
190 static inline bool is_root_cache(struct kmem_cache *s)
191 {
192 return s->memcg_params.is_root_cache;
193 }
194
195 static inline bool slab_equal_or_root(struct kmem_cache *s,
196 struct kmem_cache *p)
197 {
198 return p == s || p == s->memcg_params.root_cache;
199 }
200
201 /*
202 * We use suffixes to the name in memcg because we can't have caches
203 * created in the system with the same name. But when we print them
204 * locally, better refer to them with the base name
205 */
206 static inline const char *cache_name(struct kmem_cache *s)
207 {
208 if (!is_root_cache(s))
209 s = s->memcg_params.root_cache;
210 return s->name;
211 }
212
213 /*
214 * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
215 * That said the caller must assure the memcg's cache won't go away by either
216 * taking a css reference to the owner cgroup, or holding the slab_mutex.
217 */
218 static inline struct kmem_cache *
219 cache_from_memcg_idx(struct kmem_cache *s, int idx)
220 {
221 struct kmem_cache *cachep;
222 struct memcg_cache_array *arr;
223
224 rcu_read_lock();
225 arr = rcu_dereference(s->memcg_params.memcg_caches);
226
227 /*
228 * Make sure we will access the up-to-date value. The code updating
229 * memcg_caches issues a write barrier to match this (see
230 * memcg_create_kmem_cache()).
231 */
232 cachep = lockless_dereference(arr->entries[idx]);
233 rcu_read_unlock();
234
235 return cachep;
236 }
237
238 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
239 {
240 if (is_root_cache(s))
241 return s;
242 return s->memcg_params.root_cache;
243 }
244
245 static __always_inline int memcg_charge_slab(struct page *page,
246 gfp_t gfp, int order,
247 struct kmem_cache *s)
248 {
249 int ret;
250
251 if (!memcg_kmem_enabled())
252 return 0;
253 if (is_root_cache(s))
254 return 0;
255
256 ret = __memcg_kmem_charge_memcg(page, gfp, order,
257 s->memcg_params.memcg);
258 if (ret)
259 return ret;
260
261 memcg_kmem_update_page_stat(page,
262 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
263 MEMCG_SLAB_RECLAIMABLE : MEMCG_SLAB_UNRECLAIMABLE,
264 1 << order);
265 return 0;
266 }
267
268 static __always_inline void memcg_uncharge_slab(struct page *page, int order,
269 struct kmem_cache *s)
270 {
271 memcg_kmem_update_page_stat(page,
272 (s->flags & SLAB_RECLAIM_ACCOUNT) ?
273 MEMCG_SLAB_RECLAIMABLE : MEMCG_SLAB_UNRECLAIMABLE,
274 -(1 << order));
275 memcg_kmem_uncharge(page, order);
276 }
277
278 extern void slab_init_memcg_params(struct kmem_cache *);
279
280 #else /* CONFIG_MEMCG && !CONFIG_SLOB */
281
282 #define for_each_memcg_cache(iter, root) \
283 for ((void)(iter), (void)(root); 0; )
284
285 static inline bool is_root_cache(struct kmem_cache *s)
286 {
287 return true;
288 }
289
290 static inline bool slab_equal_or_root(struct kmem_cache *s,
291 struct kmem_cache *p)
292 {
293 return true;
294 }
295
296 static inline const char *cache_name(struct kmem_cache *s)
297 {
298 return s->name;
299 }
300
301 static inline struct kmem_cache *
302 cache_from_memcg_idx(struct kmem_cache *s, int idx)
303 {
304 return NULL;
305 }
306
307 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
308 {
309 return s;
310 }
311
312 static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
313 struct kmem_cache *s)
314 {
315 return 0;
316 }
317
318 static inline void memcg_uncharge_slab(struct page *page, int order,
319 struct kmem_cache *s)
320 {
321 }
322
323 static inline void slab_init_memcg_params(struct kmem_cache *s)
324 {
325 }
326 #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
327
328 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
329 {
330 struct kmem_cache *cachep;
331 struct page *page;
332
333 /*
334 * When kmemcg is not being used, both assignments should return the
335 * same value. but we don't want to pay the assignment price in that
336 * case. If it is not compiled in, the compiler should be smart enough
337 * to not do even the assignment. In that case, slab_equal_or_root
338 * will also be a constant.
339 */
340 if (!memcg_kmem_enabled() &&
341 !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
342 return s;
343
344 page = virt_to_head_page(x);
345 cachep = page->slab_cache;
346 if (slab_equal_or_root(cachep, s))
347 return cachep;
348
349 pr_err("%s: Wrong slab cache. %s but object is from %s\n",
350 __func__, s->name, cachep->name);
351 WARN_ON_ONCE(1);
352 return s;
353 }
354
355 static inline size_t slab_ksize(const struct kmem_cache *s)
356 {
357 #ifndef CONFIG_SLUB
358 return s->object_size;
359
360 #else /* CONFIG_SLUB */
361 # ifdef CONFIG_SLUB_DEBUG
362 /*
363 * Debugging requires use of the padding between object
364 * and whatever may come after it.
365 */
366 if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
367 return s->object_size;
368 # endif
369 /*
370 * If we have the need to store the freelist pointer
371 * back there or track user information then we can
372 * only use the space before that information.
373 */
374 if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
375 return s->inuse;
376 /*
377 * Else we can use all the padding etc for the allocation
378 */
379 return s->size;
380 #endif
381 }
382
383 static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
384 gfp_t flags)
385 {
386 flags &= gfp_allowed_mask;
387 lockdep_trace_alloc(flags);
388 might_sleep_if(gfpflags_allow_blocking(flags));
389
390 if (should_failslab(s, flags))
391 return NULL;
392
393 return memcg_kmem_get_cache(s, flags);
394 }
395
396 static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
397 size_t size, void **p)
398 {
399 size_t i;
400
401 flags &= gfp_allowed_mask;
402 for (i = 0; i < size; i++) {
403 void *object = p[i];
404
405 kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
406 kmemleak_alloc_recursive(object, s->object_size, 1,
407 s->flags, flags);
408 kasan_slab_alloc(s, object, flags);
409 }
410 memcg_kmem_put_cache(s);
411 }
412
413 #ifndef CONFIG_SLOB
414 /*
415 * The slab lists for all objects.
416 */
417 struct kmem_cache_node {
418 spinlock_t list_lock;
419
420 #ifdef CONFIG_SLAB
421 struct list_head slabs_partial; /* partial list first, better asm code */
422 struct list_head slabs_full;
423 struct list_head slabs_free;
424 unsigned long free_objects;
425 unsigned int free_limit;
426 unsigned int colour_next; /* Per-node cache coloring */
427 struct array_cache *shared; /* shared per node */
428 struct alien_cache **alien; /* on other nodes */
429 unsigned long next_reap; /* updated without locking */
430 int free_touched; /* updated without locking */
431 #endif
432
433 #ifdef CONFIG_SLUB
434 unsigned long nr_partial;
435 struct list_head partial;
436 #ifdef CONFIG_SLUB_DEBUG
437 atomic_long_t nr_slabs;
438 atomic_long_t total_objects;
439 struct list_head full;
440 #endif
441 #endif
442
443 };
444
445 static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
446 {
447 return s->node[node];
448 }
449
450 /*
451 * Iterator over all nodes. The body will be executed for each node that has
452 * a kmem_cache_node structure allocated (which is true for all online nodes)
453 */
454 #define for_each_kmem_cache_node(__s, __node, __n) \
455 for (__node = 0; __node < nr_node_ids; __node++) \
456 if ((__n = get_node(__s, __node)))
457
458 #endif
459
460 void *slab_start(struct seq_file *m, loff_t *pos);
461 void *slab_next(struct seq_file *m, void *p, loff_t *pos);
462 void slab_stop(struct seq_file *m, void *p);
463 int memcg_slab_show(struct seq_file *m, void *p);
464
465 #endif /* MM_SLAB_H */