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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  #include <linux/random.h>
46  
47  /*
48   * State of the slab allocator.
49   *
50   * This is used to describe the states of the allocator during bootup.
51   * Allocators use this to gradually bootstrap themselves. Most allocators
52   * have the problem that the structures used for managing slab caches are
53   * allocated from slab caches themselves.
54   */
55  enum slab_state {
56  	DOWN,			/* No slab functionality yet */
57  	PARTIAL,		/* SLUB: kmem_cache_node available */
58  	PARTIAL_NODE,		/* SLAB: kmalloc size for node struct available */
59  	UP,			/* Slab caches usable but not all extras yet */
60  	FULL			/* Everything is working */
61  };
62  
63  extern enum slab_state slab_state;
64  
65  /* The slab cache mutex protects the management structures during changes */
66  extern struct mutex slab_mutex;
67  
68  /* The list of all slab caches on the system */
69  extern struct list_head slab_caches;
70  
71  /* The slab cache that manages slab cache information */
72  extern struct kmem_cache *kmem_cache;
73  
74  unsigned long calculate_alignment(unsigned long flags,
75  		unsigned long align, unsigned long size);
76  
77  #ifndef CONFIG_SLOB
78  /* Kmalloc array related functions */
79  void setup_kmalloc_cache_index_table(void);
80  void create_kmalloc_caches(unsigned long);
81  
82  /* Find the kmalloc slab corresponding for a certain size */
83  struct kmem_cache *kmalloc_slab(size_t, gfp_t);
84  #endif
85  
86  
87  /* Functions provided by the slab allocators */
88  extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
89  
90  extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
91  			unsigned long flags);
92  extern void create_boot_cache(struct kmem_cache *, const char *name,
93  			size_t size, unsigned long flags);
94  
95  int slab_unmergeable(struct kmem_cache *s);
96  struct kmem_cache *find_mergeable(size_t size, size_t align,
97  		unsigned long flags, const char *name, void (*ctor)(void *));
98  #ifndef CONFIG_SLOB
99  struct kmem_cache *
100  __kmem_cache_alias(const char *name, size_t size, size_t align,
101  		   unsigned long flags, void (*ctor)(void *));
102  
103  unsigned long kmem_cache_flags(unsigned long object_size,
104  	unsigned long flags, const char *name,
105  	void (*ctor)(void *));
106  #else
107  static inline struct kmem_cache *
__kmem_cache_alias(const char * name,size_t size,size_t align,unsigned long flags,void (* ctor)(void *))108  __kmem_cache_alias(const char *name, size_t size, size_t align,
109  		   unsigned long flags, void (*ctor)(void *))
110  { return NULL; }
111  
kmem_cache_flags(unsigned long object_size,unsigned long flags,const char * name,void (* ctor)(void *))112  static inline unsigned long kmem_cache_flags(unsigned long object_size,
113  	unsigned long flags, const char *name,
114  	void (*ctor)(void *))
115  {
116  	return flags;
117  }
118  #endif
119  
120  
121  /* Legal flag mask for kmem_cache_create(), for various configurations */
122  #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
123  			 SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )
124  
125  #if defined(CONFIG_DEBUG_SLAB)
126  #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
127  #elif defined(CONFIG_SLUB_DEBUG)
128  #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
129  			  SLAB_TRACE | SLAB_CONSISTENCY_CHECKS)
130  #else
131  #define SLAB_DEBUG_FLAGS (0)
132  #endif
133  
134  #if defined(CONFIG_SLAB)
135  #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
136  			  SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \
137  			  SLAB_NOTRACK | SLAB_ACCOUNT)
138  #elif defined(CONFIG_SLUB)
139  #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
140  			  SLAB_TEMPORARY | SLAB_NOTRACK | SLAB_ACCOUNT)
141  #else
142  #define SLAB_CACHE_FLAGS (0)
143  #endif
144  
145  #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)
146  
147  int __kmem_cache_shutdown(struct kmem_cache *);
148  void __kmem_cache_release(struct kmem_cache *);
149  int __kmem_cache_shrink(struct kmem_cache *);
150  void slab_kmem_cache_release(struct kmem_cache *);
151  
152  struct seq_file;
153  struct file;
154  
155  struct slabinfo {
156  	unsigned long active_objs;
157  	unsigned long num_objs;
158  	unsigned long active_slabs;
159  	unsigned long num_slabs;
160  	unsigned long shared_avail;
161  	unsigned int limit;
162  	unsigned int batchcount;
163  	unsigned int shared;
164  	unsigned int objects_per_slab;
165  	unsigned int cache_order;
166  };
167  
168  void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
169  void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
170  ssize_t slabinfo_write(struct file *file, const char __user *buffer,
171  		       size_t count, loff_t *ppos);
172  
173  /*
174   * Generic implementation of bulk operations
175   * These are useful for situations in which the allocator cannot
176   * perform optimizations. In that case segments of the object listed
177   * may be allocated or freed using these operations.
178   */
179  void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
180  int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
181  
182  #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB)
183  /*
184   * Iterate over all memcg caches of the given root cache. The caller must hold
185   * slab_mutex.
186   */
187  #define for_each_memcg_cache(iter, root) \
188  	list_for_each_entry(iter, &(root)->memcg_params.list, \
189  			    memcg_params.list)
190  
is_root_cache(struct kmem_cache * s)191  static inline bool is_root_cache(struct kmem_cache *s)
192  {
193  	return s->memcg_params.is_root_cache;
194  }
195  
slab_equal_or_root(struct kmem_cache * s,struct kmem_cache * p)196  static inline bool slab_equal_or_root(struct kmem_cache *s,
197  				      struct kmem_cache *p)
198  {
199  	return p == s || p == s->memcg_params.root_cache;
200  }
201  
202  /*
203   * We use suffixes to the name in memcg because we can't have caches
204   * created in the system with the same name. But when we print them
205   * locally, better refer to them with the base name
206   */
cache_name(struct kmem_cache * s)207  static inline const char *cache_name(struct kmem_cache *s)
208  {
209  	if (!is_root_cache(s))
210  		s = s->memcg_params.root_cache;
211  	return s->name;
212  }
213  
214  /*
215   * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
216   * That said the caller must assure the memcg's cache won't go away by either
217   * taking a css reference to the owner cgroup, or holding the slab_mutex.
218   */
219  static inline struct kmem_cache *
cache_from_memcg_idx(struct kmem_cache * s,int idx)220  cache_from_memcg_idx(struct kmem_cache *s, int idx)
221  {
222  	struct kmem_cache *cachep;
223  	struct memcg_cache_array *arr;
224  
225  	rcu_read_lock();
226  	arr = rcu_dereference(s->memcg_params.memcg_caches);
227  
228  	/*
229  	 * Make sure we will access the up-to-date value. The code updating
230  	 * memcg_caches issues a write barrier to match this (see
231  	 * memcg_create_kmem_cache()).
232  	 */
233  	cachep = lockless_dereference(arr->entries[idx]);
234  	rcu_read_unlock();
235  
236  	return cachep;
237  }
238  
memcg_root_cache(struct kmem_cache * s)239  static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
240  {
241  	if (is_root_cache(s))
242  		return s;
243  	return s->memcg_params.root_cache;
244  }
245  
memcg_charge_slab(struct page * page,gfp_t gfp,int order,struct kmem_cache * s)246  static __always_inline int memcg_charge_slab(struct page *page,
247  					     gfp_t gfp, int order,
248  					     struct kmem_cache *s)
249  {
250  	int ret;
251  
252  	if (!memcg_kmem_enabled())
253  		return 0;
254  	if (is_root_cache(s))
255  		return 0;
256  
257  	ret = memcg_kmem_charge_memcg(page, gfp, order, 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  
memcg_uncharge_slab(struct page * page,int order,struct kmem_cache * s)268  static __always_inline void memcg_uncharge_slab(struct page *page, int order,
269  						struct kmem_cache *s)
270  {
271  	if (!memcg_kmem_enabled())
272  		return;
273  
274  	memcg_kmem_update_page_stat(page,
275  			(s->flags & SLAB_RECLAIM_ACCOUNT) ?
276  			MEMCG_SLAB_RECLAIMABLE : MEMCG_SLAB_UNRECLAIMABLE,
277  			-(1 << order));
278  	memcg_kmem_uncharge(page, order);
279  }
280  
281  extern void slab_init_memcg_params(struct kmem_cache *);
282  
283  #else /* CONFIG_MEMCG && !CONFIG_SLOB */
284  
285  #define for_each_memcg_cache(iter, root) \
286  	for ((void)(iter), (void)(root); 0; )
287  
is_root_cache(struct kmem_cache * s)288  static inline bool is_root_cache(struct kmem_cache *s)
289  {
290  	return true;
291  }
292  
slab_equal_or_root(struct kmem_cache * s,struct kmem_cache * p)293  static inline bool slab_equal_or_root(struct kmem_cache *s,
294  				      struct kmem_cache *p)
295  {
296  	return true;
297  }
298  
cache_name(struct kmem_cache * s)299  static inline const char *cache_name(struct kmem_cache *s)
300  {
301  	return s->name;
302  }
303  
304  static inline struct kmem_cache *
cache_from_memcg_idx(struct kmem_cache * s,int idx)305  cache_from_memcg_idx(struct kmem_cache *s, int idx)
306  {
307  	return NULL;
308  }
309  
memcg_root_cache(struct kmem_cache * s)310  static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
311  {
312  	return s;
313  }
314  
memcg_charge_slab(struct page * page,gfp_t gfp,int order,struct kmem_cache * s)315  static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order,
316  				    struct kmem_cache *s)
317  {
318  	return 0;
319  }
320  
memcg_uncharge_slab(struct page * page,int order,struct kmem_cache * s)321  static inline void memcg_uncharge_slab(struct page *page, int order,
322  				       struct kmem_cache *s)
323  {
324  }
325  
slab_init_memcg_params(struct kmem_cache * s)326  static inline void slab_init_memcg_params(struct kmem_cache *s)
327  {
328  }
329  #endif /* CONFIG_MEMCG && !CONFIG_SLOB */
330  
cache_from_obj(struct kmem_cache * s,void * x)331  static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
332  {
333  	struct kmem_cache *cachep;
334  	struct page *page;
335  
336  	/*
337  	 * When kmemcg is not being used, both assignments should return the
338  	 * same value. but we don't want to pay the assignment price in that
339  	 * case. If it is not compiled in, the compiler should be smart enough
340  	 * to not do even the assignment. In that case, slab_equal_or_root
341  	 * will also be a constant.
342  	 */
343  	if (!memcg_kmem_enabled() &&
344  	    !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS))
345  		return s;
346  
347  	page = virt_to_head_page(x);
348  	cachep = page->slab_cache;
349  	if (slab_equal_or_root(cachep, s))
350  		return cachep;
351  
352  	pr_err("%s: Wrong slab cache. %s but object is from %s\n",
353  	       __func__, s->name, cachep->name);
354  	WARN_ON_ONCE(1);
355  	return s;
356  }
357  
slab_ksize(const struct kmem_cache * s)358  static inline size_t slab_ksize(const struct kmem_cache *s)
359  {
360  #ifndef CONFIG_SLUB
361  	return s->object_size;
362  
363  #else /* CONFIG_SLUB */
364  # ifdef CONFIG_SLUB_DEBUG
365  	/*
366  	 * Debugging requires use of the padding between object
367  	 * and whatever may come after it.
368  	 */
369  	if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
370  		return s->object_size;
371  # endif
372  	if (s->flags & SLAB_KASAN)
373  		return s->object_size;
374  	/*
375  	 * If we have the need to store the freelist pointer
376  	 * back there or track user information then we can
377  	 * only use the space before that information.
378  	 */
379  	if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
380  		return s->inuse;
381  	/*
382  	 * Else we can use all the padding etc for the allocation
383  	 */
384  	return s->size;
385  #endif
386  }
387  
slab_pre_alloc_hook(struct kmem_cache * s,gfp_t flags)388  static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
389  						     gfp_t flags)
390  {
391  	flags &= gfp_allowed_mask;
392  	lockdep_trace_alloc(flags);
393  	might_sleep_if(gfpflags_allow_blocking(flags));
394  
395  	if (should_failslab(s, flags))
396  		return NULL;
397  
398  	if (memcg_kmem_enabled() &&
399  	    ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT)))
400  		return memcg_kmem_get_cache(s);
401  
402  	return s;
403  }
404  
slab_post_alloc_hook(struct kmem_cache * s,gfp_t flags,size_t size,void ** p)405  static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
406  					size_t size, void **p)
407  {
408  	size_t i;
409  
410  	flags &= gfp_allowed_mask;
411  	for (i = 0; i < size; i++) {
412  		void *object = p[i];
413  
414  		kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
415  		kmemleak_alloc_recursive(object, s->object_size, 1,
416  					 s->flags, flags);
417  		kasan_slab_alloc(s, object, flags);
418  	}
419  
420  	if (memcg_kmem_enabled())
421  		memcg_kmem_put_cache(s);
422  }
423  
424  #ifndef CONFIG_SLOB
425  /*
426   * The slab lists for all objects.
427   */
428  struct kmem_cache_node {
429  	spinlock_t list_lock;
430  
431  #ifdef CONFIG_SLAB
432  	struct list_head slabs_partial;	/* partial list first, better asm code */
433  	struct list_head slabs_full;
434  	struct list_head slabs_free;
435  	unsigned long num_slabs;
436  	unsigned long free_objects;
437  	unsigned int free_limit;
438  	unsigned int colour_next;	/* Per-node cache coloring */
439  	struct array_cache *shared;	/* shared per node */
440  	struct alien_cache **alien;	/* on other nodes */
441  	unsigned long next_reap;	/* updated without locking */
442  	int free_touched;		/* updated without locking */
443  #endif
444  
445  #ifdef CONFIG_SLUB
446  	unsigned long nr_partial;
447  	struct list_head partial;
448  #ifdef CONFIG_SLUB_DEBUG
449  	atomic_long_t nr_slabs;
450  	atomic_long_t total_objects;
451  	struct list_head full;
452  #endif
453  #endif
454  
455  };
456  
get_node(struct kmem_cache * s,int node)457  static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
458  {
459  	return s->node[node];
460  }
461  
462  /*
463   * Iterator over all nodes. The body will be executed for each node that has
464   * a kmem_cache_node structure allocated (which is true for all online nodes)
465   */
466  #define for_each_kmem_cache_node(__s, __node, __n) \
467  	for (__node = 0; __node < nr_node_ids; __node++) \
468  		 if ((__n = get_node(__s, __node)))
469  
470  #endif
471  
472  void *slab_start(struct seq_file *m, loff_t *pos);
473  void *slab_next(struct seq_file *m, void *p, loff_t *pos);
474  void slab_stop(struct seq_file *m, void *p);
475  int memcg_slab_show(struct seq_file *m, void *p);
476  
477  void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr);
478  
479  #ifdef CONFIG_SLAB_FREELIST_RANDOM
480  int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count,
481  			gfp_t gfp);
482  void cache_random_seq_destroy(struct kmem_cache *cachep);
483  #else
cache_random_seq_create(struct kmem_cache * cachep,unsigned int count,gfp_t gfp)484  static inline int cache_random_seq_create(struct kmem_cache *cachep,
485  					unsigned int count, gfp_t gfp)
486  {
487  	return 0;
488  }
cache_random_seq_destroy(struct kmem_cache * cachep)489  static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { }
490  #endif /* CONFIG_SLAB_FREELIST_RANDOM */
491  
492  #endif /* MM_SLAB_H */
493