~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/slab.h

Version: ~ [ linux-5.13-rc1 ] ~ [ linux-5.12.2 ] ~ [ linux-5.11.19 ] ~ [ linux-5.10.35 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.117 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.190 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.232 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.268 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.268 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
  3  *
  4  * (C) SGI 2006, Christoph Lameter
  5  *      Cleaned up and restructured to ease the addition of alternative
  6  *      implementations of SLAB allocators.
  7  * (C) Linux Foundation 2008-2013
  8  *      Unified interface for all slab allocators
  9  */
 10 
 11 #ifndef _LINUX_SLAB_H
 12 #define _LINUX_SLAB_H
 13 
 14 #include <linux/gfp.h>
 15 #include <linux/types.h>
 16 #include <linux/workqueue.h>
 17 
 18 
 19 /*
 20  * Flags to pass to kmem_cache_create().
 21  * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set.
 22  */
 23 #define SLAB_DEBUG_FREE         0x00000100UL    /* DEBUG: Perform (expensive) checks on free */
 24 #define SLAB_RED_ZONE           0x00000400UL    /* DEBUG: Red zone objs in a cache */
 25 #define SLAB_POISON             0x00000800UL    /* DEBUG: Poison objects */
 26 #define SLAB_HWCACHE_ALIGN      0x00002000UL    /* Align objs on cache lines */
 27 #define SLAB_CACHE_DMA          0x00004000UL    /* Use GFP_DMA memory */
 28 #define SLAB_STORE_USER         0x00010000UL    /* DEBUG: Store the last owner for bug hunting */
 29 #define SLAB_PANIC              0x00040000UL    /* Panic if kmem_cache_create() fails */
 30 /*
 31  * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS!
 32  *
 33  * This delays freeing the SLAB page by a grace period, it does _NOT_
 34  * delay object freeing. This means that if you do kmem_cache_free()
 35  * that memory location is free to be reused at any time. Thus it may
 36  * be possible to see another object there in the same RCU grace period.
 37  *
 38  * This feature only ensures the memory location backing the object
 39  * stays valid, the trick to using this is relying on an independent
 40  * object validation pass. Something like:
 41  *
 42  *  rcu_read_lock()
 43  * again:
 44  *  obj = lockless_lookup(key);
 45  *  if (obj) {
 46  *    if (!try_get_ref(obj)) // might fail for free objects
 47  *      goto again;
 48  *
 49  *    if (obj->key != key) { // not the object we expected
 50  *      put_ref(obj);
 51  *      goto again;
 52  *    }
 53  *  }
 54  *  rcu_read_unlock();
 55  *
 56  * This is useful if we need to approach a kernel structure obliquely,
 57  * from its address obtained without the usual locking. We can lock
 58  * the structure to stabilize it and check it's still at the given address,
 59  * only if we can be sure that the memory has not been meanwhile reused
 60  * for some other kind of object (which our subsystem's lock might corrupt).
 61  *
 62  * rcu_read_lock before reading the address, then rcu_read_unlock after
 63  * taking the spinlock within the structure expected at that address.
 64  */
 65 #define SLAB_DESTROY_BY_RCU     0x00080000UL    /* Defer freeing slabs to RCU */
 66 #define SLAB_MEM_SPREAD         0x00100000UL    /* Spread some memory over cpuset */
 67 #define SLAB_TRACE              0x00200000UL    /* Trace allocations and frees */
 68 
 69 /* Flag to prevent checks on free */
 70 #ifdef CONFIG_DEBUG_OBJECTS
 71 # define SLAB_DEBUG_OBJECTS     0x00400000UL
 72 #else
 73 # define SLAB_DEBUG_OBJECTS     0x00000000UL
 74 #endif
 75 
 76 #define SLAB_NOLEAKTRACE        0x00800000UL    /* Avoid kmemleak tracing */
 77 
 78 /* Don't track use of uninitialized memory */
 79 #ifdef CONFIG_KMEMCHECK
 80 # define SLAB_NOTRACK           0x01000000UL
 81 #else
 82 # define SLAB_NOTRACK           0x00000000UL
 83 #endif
 84 #ifdef CONFIG_FAILSLAB
 85 # define SLAB_FAILSLAB          0x02000000UL    /* Fault injection mark */
 86 #else
 87 # define SLAB_FAILSLAB          0x00000000UL
 88 #endif
 89 
 90 /* The following flags affect the page allocator grouping pages by mobility */
 91 #define SLAB_RECLAIM_ACCOUNT    0x00020000UL            /* Objects are reclaimable */
 92 #define SLAB_TEMPORARY          SLAB_RECLAIM_ACCOUNT    /* Objects are short-lived */
 93 /*
 94  * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
 95  *
 96  * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
 97  *
 98  * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
 99  * Both make kfree a no-op.
100  */
101 #define ZERO_SIZE_PTR ((void *)16)
102 
103 #define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
104                                 (unsigned long)ZERO_SIZE_PTR)
105 
106 #include <linux/kmemleak.h>
107 
108 struct mem_cgroup;
109 /*
110  * struct kmem_cache related prototypes
111  */
112 void __init kmem_cache_init(void);
113 int slab_is_available(void);
114 
115 struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
116                         unsigned long,
117                         void (*)(void *));
118 struct kmem_cache *
119 kmem_cache_create_memcg(struct mem_cgroup *, const char *, size_t, size_t,
120                         unsigned long, void (*)(void *), struct kmem_cache *);
121 void kmem_cache_destroy(struct kmem_cache *);
122 int kmem_cache_shrink(struct kmem_cache *);
123 void kmem_cache_free(struct kmem_cache *, void *);
124 
125 /*
126  * Please use this macro to create slab caches. Simply specify the
127  * name of the structure and maybe some flags that are listed above.
128  *
129  * The alignment of the struct determines object alignment. If you
130  * f.e. add ____cacheline_aligned_in_smp to the struct declaration
131  * then the objects will be properly aligned in SMP configurations.
132  */
133 #define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
134                 sizeof(struct __struct), __alignof__(struct __struct),\
135                 (__flags), NULL)
136 
137 /*
138  * Common kmalloc functions provided by all allocators
139  */
140 void * __must_check __krealloc(const void *, size_t, gfp_t);
141 void * __must_check krealloc(const void *, size_t, gfp_t);
142 void kfree(const void *);
143 void kzfree(const void *);
144 size_t ksize(const void *);
145 
146 /*
147  * Some archs want to perform DMA into kmalloc caches and need a guaranteed
148  * alignment larger than the alignment of a 64-bit integer.
149  * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
150  */
151 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
152 #define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
153 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
154 #define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
155 #else
156 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
157 #endif
158 
159 #ifdef CONFIG_SLOB
160 /*
161  * Common fields provided in kmem_cache by all slab allocators
162  * This struct is either used directly by the allocator (SLOB)
163  * or the allocator must include definitions for all fields
164  * provided in kmem_cache_common in their definition of kmem_cache.
165  *
166  * Once we can do anonymous structs (C11 standard) we could put a
167  * anonymous struct definition in these allocators so that the
168  * separate allocations in the kmem_cache structure of SLAB and
169  * SLUB is no longer needed.
170  */
171 struct kmem_cache {
172         unsigned int object_size;/* The original size of the object */
173         unsigned int size;      /* The aligned/padded/added on size  */
174         unsigned int align;     /* Alignment as calculated */
175         unsigned long flags;    /* Active flags on the slab */
176         const char *name;       /* Slab name for sysfs */
177         int refcount;           /* Use counter */
178         void (*ctor)(void *);   /* Called on object slot creation */
179         struct list_head list;  /* List of all slab caches on the system */
180 };
181 
182 #endif /* CONFIG_SLOB */
183 
184 /*
185  * Kmalloc array related definitions
186  */
187 
188 #ifdef CONFIG_SLAB
189 /*
190  * The largest kmalloc size supported by the SLAB allocators is
191  * 32 megabyte (2^25) or the maximum allocatable page order if that is
192  * less than 32 MB.
193  *
194  * WARNING: Its not easy to increase this value since the allocators have
195  * to do various tricks to work around compiler limitations in order to
196  * ensure proper constant folding.
197  */
198 #define KMALLOC_SHIFT_HIGH      ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
199                                 (MAX_ORDER + PAGE_SHIFT - 1) : 25)
200 #define KMALLOC_SHIFT_MAX       KMALLOC_SHIFT_HIGH
201 #ifndef KMALLOC_SHIFT_LOW
202 #define KMALLOC_SHIFT_LOW       5
203 #endif
204 #endif
205 
206 #ifdef CONFIG_SLUB
207 /*
208  * SLUB directly allocates requests fitting in to an order-1 page
209  * (PAGE_SIZE*2).  Larger requests are passed to the page allocator.
210  */
211 #define KMALLOC_SHIFT_HIGH      (PAGE_SHIFT + 1)
212 #define KMALLOC_SHIFT_MAX       (MAX_ORDER + PAGE_SHIFT)
213 #ifndef KMALLOC_SHIFT_LOW
214 #define KMALLOC_SHIFT_LOW       3
215 #endif
216 #endif
217 
218 #ifdef CONFIG_SLOB
219 /*
220  * SLOB passes all requests larger than one page to the page allocator.
221  * No kmalloc array is necessary since objects of different sizes can
222  * be allocated from the same page.
223  */
224 #define KMALLOC_SHIFT_HIGH      PAGE_SHIFT
225 #define KMALLOC_SHIFT_MAX       30
226 #ifndef KMALLOC_SHIFT_LOW
227 #define KMALLOC_SHIFT_LOW       3
228 #endif
229 #endif
230 
231 /* Maximum allocatable size */
232 #define KMALLOC_MAX_SIZE        (1UL << KMALLOC_SHIFT_MAX)
233 /* Maximum size for which we actually use a slab cache */
234 #define KMALLOC_MAX_CACHE_SIZE  (1UL << KMALLOC_SHIFT_HIGH)
235 /* Maximum order allocatable via the slab allocagtor */
236 #define KMALLOC_MAX_ORDER       (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
237 
238 /*
239  * Kmalloc subsystem.
240  */
241 #ifndef KMALLOC_MIN_SIZE
242 #define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
243 #endif
244 
245 #ifndef CONFIG_SLOB
246 extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
247 #ifdef CONFIG_ZONE_DMA
248 extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
249 #endif
250 
251 /*
252  * Figure out which kmalloc slab an allocation of a certain size
253  * belongs to.
254  * 0 = zero alloc
255  * 1 =  65 .. 96 bytes
256  * 2 = 120 .. 192 bytes
257  * n = 2^(n-1) .. 2^n -1
258  */
259 static __always_inline int kmalloc_index(size_t size)
260 {
261         if (!size)
262                 return 0;
263 
264         if (size <= KMALLOC_MIN_SIZE)
265                 return KMALLOC_SHIFT_LOW;
266 
267         if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
268                 return 1;
269         if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
270                 return 2;
271         if (size <=          8) return 3;
272         if (size <=         16) return 4;
273         if (size <=         32) return 5;
274         if (size <=         64) return 6;
275         if (size <=        128) return 7;
276         if (size <=        256) return 8;
277         if (size <=        512) return 9;
278         if (size <=       1024) return 10;
279         if (size <=   2 * 1024) return 11;
280         if (size <=   4 * 1024) return 12;
281         if (size <=   8 * 1024) return 13;
282         if (size <=  16 * 1024) return 14;
283         if (size <=  32 * 1024) return 15;
284         if (size <=  64 * 1024) return 16;
285         if (size <= 128 * 1024) return 17;
286         if (size <= 256 * 1024) return 18;
287         if (size <= 512 * 1024) return 19;
288         if (size <= 1024 * 1024) return 20;
289         if (size <=  2 * 1024 * 1024) return 21;
290         if (size <=  4 * 1024 * 1024) return 22;
291         if (size <=  8 * 1024 * 1024) return 23;
292         if (size <=  16 * 1024 * 1024) return 24;
293         if (size <=  32 * 1024 * 1024) return 25;
294         if (size <=  64 * 1024 * 1024) return 26;
295         BUG();
296 
297         /* Will never be reached. Needed because the compiler may complain */
298         return -1;
299 }
300 #endif /* !CONFIG_SLOB */
301 
302 void *__kmalloc(size_t size, gfp_t flags);
303 void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags);
304 
305 #ifdef CONFIG_NUMA
306 void *__kmalloc_node(size_t size, gfp_t flags, int node);
307 void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
308 #else
309 static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
310 {
311         return __kmalloc(size, flags);
312 }
313 
314 static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
315 {
316         return kmem_cache_alloc(s, flags);
317 }
318 #endif
319 
320 #ifdef CONFIG_TRACING
321 extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t);
322 
323 #ifdef CONFIG_NUMA
324 extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
325                                            gfp_t gfpflags,
326                                            int node, size_t size);
327 #else
328 static __always_inline void *
329 kmem_cache_alloc_node_trace(struct kmem_cache *s,
330                               gfp_t gfpflags,
331                               int node, size_t size)
332 {
333         return kmem_cache_alloc_trace(s, gfpflags, size);
334 }
335 #endif /* CONFIG_NUMA */
336 
337 #else /* CONFIG_TRACING */
338 static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
339                 gfp_t flags, size_t size)
340 {
341         return kmem_cache_alloc(s, flags);
342 }
343 
344 static __always_inline void *
345 kmem_cache_alloc_node_trace(struct kmem_cache *s,
346                               gfp_t gfpflags,
347                               int node, size_t size)
348 {
349         return kmem_cache_alloc_node(s, gfpflags, node);
350 }
351 #endif /* CONFIG_TRACING */
352 
353 #ifdef CONFIG_SLAB
354 #include <linux/slab_def.h>
355 #endif
356 
357 #ifdef CONFIG_SLUB
358 #include <linux/slub_def.h>
359 #endif
360 
361 static __always_inline void *
362 kmalloc_order(size_t size, gfp_t flags, unsigned int order)
363 {
364         void *ret;
365 
366         flags |= (__GFP_COMP | __GFP_KMEMCG);
367         ret = (void *) __get_free_pages(flags, order);
368         kmemleak_alloc(ret, size, 1, flags);
369         return ret;
370 }
371 
372 #ifdef CONFIG_TRACING
373 extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
374 #else
375 static __always_inline void *
376 kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
377 {
378         return kmalloc_order(size, flags, order);
379 }
380 #endif
381 
382 static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
383 {
384         unsigned int order = get_order(size);
385         return kmalloc_order_trace(size, flags, order);
386 }
387 
388 /**
389  * kmalloc - allocate memory
390  * @size: how many bytes of memory are required.
391  * @flags: the type of memory to allocate.
392  *
393  * kmalloc is the normal method of allocating memory
394  * for objects smaller than page size in the kernel.
395  *
396  * The @flags argument may be one of:
397  *
398  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
399  *
400  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
401  *
402  * %GFP_ATOMIC - Allocation will not sleep.  May use emergency pools.
403  *   For example, use this inside interrupt handlers.
404  *
405  * %GFP_HIGHUSER - Allocate pages from high memory.
406  *
407  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
408  *
409  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
410  *
411  * %GFP_NOWAIT - Allocation will not sleep.
412  *
413  * %__GFP_THISNODE - Allocate node-local memory only.
414  *
415  * %GFP_DMA - Allocation suitable for DMA.
416  *   Should only be used for kmalloc() caches. Otherwise, use a
417  *   slab created with SLAB_DMA.
418  *
419  * Also it is possible to set different flags by OR'ing
420  * in one or more of the following additional @flags:
421  *
422  * %__GFP_COLD - Request cache-cold pages instead of
423  *   trying to return cache-warm pages.
424  *
425  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
426  *
427  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
428  *   (think twice before using).
429  *
430  * %__GFP_NORETRY - If memory is not immediately available,
431  *   then give up at once.
432  *
433  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
434  *
435  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
436  *
437  * There are other flags available as well, but these are not intended
438  * for general use, and so are not documented here. For a full list of
439  * potential flags, always refer to linux/gfp.h.
440  */
441 static __always_inline void *kmalloc(size_t size, gfp_t flags)
442 {
443         if (__builtin_constant_p(size)) {
444                 if (size > KMALLOC_MAX_CACHE_SIZE)
445                         return kmalloc_large(size, flags);
446 #ifndef CONFIG_SLOB
447                 if (!(flags & GFP_DMA)) {
448                         int index = kmalloc_index(size);
449 
450                         if (!index)
451                                 return ZERO_SIZE_PTR;
452 
453                         return kmem_cache_alloc_trace(kmalloc_caches[index],
454                                         flags, size);
455                 }
456 #endif
457         }
458         return __kmalloc(size, flags);
459 }
460 
461 /*
462  * Determine size used for the nth kmalloc cache.
463  * return size or 0 if a kmalloc cache for that
464  * size does not exist
465  */
466 static __always_inline int kmalloc_size(int n)
467 {
468 #ifndef CONFIG_SLOB
469         if (n > 2)
470                 return 1 << n;
471 
472         if (n == 1 && KMALLOC_MIN_SIZE <= 32)
473                 return 96;
474 
475         if (n == 2 && KMALLOC_MIN_SIZE <= 64)
476                 return 192;
477 #endif
478         return 0;
479 }
480 
481 static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
482 {
483 #ifndef CONFIG_SLOB
484         if (__builtin_constant_p(size) &&
485                 size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
486                 int i = kmalloc_index(size);
487 
488                 if (!i)
489                         return ZERO_SIZE_PTR;
490 
491                 return kmem_cache_alloc_node_trace(kmalloc_caches[i],
492                                                 flags, node, size);
493         }
494 #endif
495         return __kmalloc_node(size, flags, node);
496 }
497 
498 /*
499  * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
500  * Intended for arches that get misalignment faults even for 64 bit integer
501  * aligned buffers.
502  */
503 #ifndef ARCH_SLAB_MINALIGN
504 #define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
505 #endif
506 /*
507  * This is the main placeholder for memcg-related information in kmem caches.
508  * struct kmem_cache will hold a pointer to it, so the memory cost while
509  * disabled is 1 pointer. The runtime cost while enabled, gets bigger than it
510  * would otherwise be if that would be bundled in kmem_cache: we'll need an
511  * extra pointer chase. But the trade off clearly lays in favor of not
512  * penalizing non-users.
513  *
514  * Both the root cache and the child caches will have it. For the root cache,
515  * this will hold a dynamically allocated array large enough to hold
516  * information about the currently limited memcgs in the system. To allow the
517  * array to be accessed without taking any locks, on relocation we free the old
518  * version only after a grace period.
519  *
520  * Child caches will hold extra metadata needed for its operation. Fields are:
521  *
522  * @memcg: pointer to the memcg this cache belongs to
523  * @list: list_head for the list of all caches in this memcg
524  * @root_cache: pointer to the global, root cache, this cache was derived from
525  * @dead: set to true after the memcg dies; the cache may still be around.
526  * @nr_pages: number of pages that belongs to this cache.
527  * @destroy: worker to be called whenever we are ready, or believe we may be
528  *           ready, to destroy this cache.
529  */
530 struct memcg_cache_params {
531         bool is_root_cache;
532         union {
533                 struct {
534                         struct rcu_head rcu_head;
535                         struct kmem_cache *memcg_caches[0];
536                 };
537                 struct {
538                         struct mem_cgroup *memcg;
539                         struct list_head list;
540                         struct kmem_cache *root_cache;
541                         bool dead;
542                         atomic_t nr_pages;
543                         struct work_struct destroy;
544                 };
545         };
546 };
547 
548 int memcg_update_all_caches(int num_memcgs);
549 
550 struct seq_file;
551 int cache_show(struct kmem_cache *s, struct seq_file *m);
552 void print_slabinfo_header(struct seq_file *m);
553 
554 /**
555  * kmalloc_array - allocate memory for an array.
556  * @n: number of elements.
557  * @size: element size.
558  * @flags: the type of memory to allocate (see kmalloc).
559  */
560 static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
561 {
562         if (size != 0 && n > SIZE_MAX / size)
563                 return NULL;
564         return __kmalloc(n * size, flags);
565 }
566 
567 /**
568  * kcalloc - allocate memory for an array. The memory is set to zero.
569  * @n: number of elements.
570  * @size: element size.
571  * @flags: the type of memory to allocate (see kmalloc).
572  */
573 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
574 {
575         return kmalloc_array(n, size, flags | __GFP_ZERO);
576 }
577 
578 /*
579  * kmalloc_track_caller is a special version of kmalloc that records the
580  * calling function of the routine calling it for slab leak tracking instead
581  * of just the calling function (confusing, eh?).
582  * It's useful when the call to kmalloc comes from a widely-used standard
583  * allocator where we care about the real place the memory allocation
584  * request comes from.
585  */
586 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \
587         (defined(CONFIG_SLAB) && defined(CONFIG_TRACING)) || \
588         (defined(CONFIG_SLOB) && defined(CONFIG_TRACING))
589 extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
590 #define kmalloc_track_caller(size, flags) \
591         __kmalloc_track_caller(size, flags, _RET_IP_)
592 #else
593 #define kmalloc_track_caller(size, flags) \
594         __kmalloc(size, flags)
595 #endif /* DEBUG_SLAB */
596 
597 #ifdef CONFIG_NUMA
598 /*
599  * kmalloc_node_track_caller is a special version of kmalloc_node that
600  * records the calling function of the routine calling it for slab leak
601  * tracking instead of just the calling function (confusing, eh?).
602  * It's useful when the call to kmalloc_node comes from a widely-used
603  * standard allocator where we care about the real place the memory
604  * allocation request comes from.
605  */
606 #if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB) || \
607         (defined(CONFIG_SLAB) && defined(CONFIG_TRACING)) || \
608         (defined(CONFIG_SLOB) && defined(CONFIG_TRACING))
609 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
610 #define kmalloc_node_track_caller(size, flags, node) \
611         __kmalloc_node_track_caller(size, flags, node, \
612                         _RET_IP_)
613 #else
614 #define kmalloc_node_track_caller(size, flags, node) \
615         __kmalloc_node(size, flags, node)
616 #endif
617 
618 #else /* CONFIG_NUMA */
619 
620 #define kmalloc_node_track_caller(size, flags, node) \
621         kmalloc_track_caller(size, flags)
622 
623 #endif /* CONFIG_NUMA */
624 
625 /*
626  * Shortcuts
627  */
628 static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
629 {
630         return kmem_cache_alloc(k, flags | __GFP_ZERO);
631 }
632 
633 /**
634  * kzalloc - allocate memory. The memory is set to zero.
635  * @size: how many bytes of memory are required.
636  * @flags: the type of memory to allocate (see kmalloc).
637  */
638 static inline void *kzalloc(size_t size, gfp_t flags)
639 {
640         return kmalloc(size, flags | __GFP_ZERO);
641 }
642 
643 /**
644  * kzalloc_node - allocate zeroed memory from a particular memory node.
645  * @size: how many bytes of memory are required.
646  * @flags: the type of memory to allocate (see kmalloc).
647  * @node: memory node from which to allocate
648  */
649 static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
650 {
651         return kmalloc_node(size, flags | __GFP_ZERO, node);
652 }
653 
654 /*
655  * Determine the size of a slab object
656  */
657 static inline unsigned int kmem_cache_size(struct kmem_cache *s)
658 {
659         return s->object_size;
660 }
661 
662 void __init kmem_cache_init_late(void);
663 
664 #endif  /* _LINUX_SLAB_H */
665 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp