xref: /linux-6.15/include/linux/slab.h (revision 173d6681)
1 /*
2  * linux/include/linux/slab.h
3  * Written by Mark Hemment, 1996.
4  * ([email protected])
5  */
6 
7 #ifndef _LINUX_SLAB_H
8 #define	_LINUX_SLAB_H
9 
10 #ifdef __KERNEL__
11 
12 #include <linux/gfp.h>
13 #include <linux/init.h>
14 #include <linux/types.h>
15 #include <asm/page.h>		/* kmalloc_sizes.h needs PAGE_SIZE */
16 #include <asm/cache.h>		/* kmalloc_sizes.h needs L1_CACHE_BYTES */
17 #include <linux/compiler.h>
18 
19 /* kmem_cache_t exists for legacy reasons and is not used by code in mm */
20 typedef struct kmem_cache kmem_cache_t __deprecated;
21 
22 /* flags to pass to kmem_cache_create().
23  * The first 3 are only valid when the allocator as been build
24  * SLAB_DEBUG_SUPPORT.
25  */
26 #define	SLAB_DEBUG_FREE		0x00000100UL	/* Peform (expensive) checks on free */
27 #define	SLAB_DEBUG_INITIAL	0x00000200UL	/* Call constructor (as verifier) */
28 #define	SLAB_RED_ZONE		0x00000400UL	/* Red zone objs in a cache */
29 #define	SLAB_POISON		0x00000800UL	/* Poison objects */
30 #define	SLAB_HWCACHE_ALIGN	0x00002000UL	/* align objs on a h/w cache lines */
31 #define SLAB_CACHE_DMA		0x00004000UL	/* use GFP_DMA memory */
32 #define SLAB_MUST_HWCACHE_ALIGN	0x00008000UL	/* force alignment */
33 #define SLAB_STORE_USER		0x00010000UL	/* store the last owner for bug hunting */
34 #define SLAB_RECLAIM_ACCOUNT	0x00020000UL	/* track pages allocated to indicate
35 						   what is reclaimable later*/
36 #define SLAB_PANIC		0x00040000UL	/* panic if kmem_cache_create() fails */
37 #define SLAB_DESTROY_BY_RCU	0x00080000UL	/* defer freeing pages to RCU */
38 #define SLAB_MEM_SPREAD		0x00100000UL	/* Spread some memory over cpuset */
39 
40 /* flags passed to a constructor func */
41 #define	SLAB_CTOR_CONSTRUCTOR	0x001UL		/* if not set, then deconstructor */
42 #define SLAB_CTOR_ATOMIC	0x002UL		/* tell constructor it can't sleep */
43 #define	SLAB_CTOR_VERIFY	0x004UL		/* tell constructor it's a verify call */
44 
45 #ifndef CONFIG_SLOB
46 
47 /* prototypes */
48 extern void __init kmem_cache_init(void);
49 
50 extern struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
51 			unsigned long,
52 			void (*)(void *, struct kmem_cache *, unsigned long),
53 			void (*)(void *, struct kmem_cache *, unsigned long));
54 extern void kmem_cache_destroy(struct kmem_cache *);
55 extern int kmem_cache_shrink(struct kmem_cache *);
56 extern void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
57 extern void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
58 extern void kmem_cache_free(struct kmem_cache *, void *);
59 extern unsigned int kmem_cache_size(struct kmem_cache *);
60 extern const char *kmem_cache_name(struct kmem_cache *);
61 
62 /* Size description struct for general caches. */
63 struct cache_sizes {
64 	size_t		 	cs_size;
65 	struct kmem_cache	*cs_cachep;
66 	struct kmem_cache	*cs_dmacachep;
67 };
68 extern struct cache_sizes malloc_sizes[];
69 
70 extern void *__kmalloc(size_t, gfp_t);
71 
72 /**
73  * kmalloc - allocate memory
74  * @size: how many bytes of memory are required.
75  * @flags: the type of memory to allocate.
76  *
77  * kmalloc is the normal method of allocating memory
78  * in the kernel.
79  *
80  * The @flags argument may be one of:
81  *
82  * %GFP_USER - Allocate memory on behalf of user.  May sleep.
83  *
84  * %GFP_KERNEL - Allocate normal kernel ram.  May sleep.
85  *
86  * %GFP_ATOMIC - Allocation will not sleep.
87  *   For example, use this inside interrupt handlers.
88  *
89  * %GFP_HIGHUSER - Allocate pages from high memory.
90  *
91  * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
92  *
93  * %GFP_NOFS - Do not make any fs calls while trying to get memory.
94  *
95  * Also it is possible to set different flags by OR'ing
96  * in one or more of the following additional @flags:
97  *
98  * %__GFP_COLD - Request cache-cold pages instead of
99  *   trying to return cache-warm pages.
100  *
101  * %__GFP_DMA - Request memory from the DMA-capable zone.
102  *
103  * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
104  *
105  * %__GFP_HIGHMEM - Allocated memory may be from highmem.
106  *
107  * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
108  *   (think twice before using).
109  *
110  * %__GFP_NORETRY - If memory is not immediately available,
111  *   then give up at once.
112  *
113  * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
114  *
115  * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
116  */
117 static inline void *kmalloc(size_t size, gfp_t flags)
118 {
119 	if (__builtin_constant_p(size)) {
120 		int i = 0;
121 #define CACHE(x) \
122 		if (size <= x) \
123 			goto found; \
124 		else \
125 			i++;
126 #include "kmalloc_sizes.h"
127 #undef CACHE
128 		{
129 			extern void __you_cannot_kmalloc_that_much(void);
130 			__you_cannot_kmalloc_that_much();
131 		}
132 found:
133 		return kmem_cache_alloc((flags & GFP_DMA) ?
134 			malloc_sizes[i].cs_dmacachep :
135 			malloc_sizes[i].cs_cachep, flags);
136 	}
137 	return __kmalloc(size, flags);
138 }
139 
140 /*
141  * kmalloc_track_caller is a special version of kmalloc that records the
142  * calling function of the routine calling it for slab leak tracking instead
143  * of just the calling function (confusing, eh?).
144  * It's useful when the call to kmalloc comes from a widely-used standard
145  * allocator where we care about the real place the memory allocation
146  * request comes from.
147  */
148 #ifndef CONFIG_DEBUG_SLAB
149 #define kmalloc_track_caller(size, flags) \
150 	__kmalloc(size, flags)
151 #else
152 extern void *__kmalloc_track_caller(size_t, gfp_t, void*);
153 #define kmalloc_track_caller(size, flags) \
154 	__kmalloc_track_caller(size, flags, __builtin_return_address(0))
155 #endif
156 
157 extern void *__kzalloc(size_t, gfp_t);
158 
159 /**
160  * kzalloc - allocate memory. The memory is set to zero.
161  * @size: how many bytes of memory are required.
162  * @flags: the type of memory to allocate (see kmalloc).
163  */
164 static inline void *kzalloc(size_t size, gfp_t flags)
165 {
166 	if (__builtin_constant_p(size)) {
167 		int i = 0;
168 #define CACHE(x) \
169 		if (size <= x) \
170 			goto found; \
171 		else \
172 			i++;
173 #include "kmalloc_sizes.h"
174 #undef CACHE
175 		{
176 			extern void __you_cannot_kzalloc_that_much(void);
177 			__you_cannot_kzalloc_that_much();
178 		}
179 found:
180 		return kmem_cache_zalloc((flags & GFP_DMA) ?
181 			malloc_sizes[i].cs_dmacachep :
182 			malloc_sizes[i].cs_cachep, flags);
183 	}
184 	return __kzalloc(size, flags);
185 }
186 
187 /**
188  * kcalloc - allocate memory for an array. The memory is set to zero.
189  * @n: number of elements.
190  * @size: element size.
191  * @flags: the type of memory to allocate.
192  */
193 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
194 {
195 	if (n != 0 && size > ULONG_MAX / n)
196 		return NULL;
197 	return kzalloc(n * size, flags);
198 }
199 
200 extern void kfree(const void *);
201 extern unsigned int ksize(const void *);
202 extern int slab_is_available(void);
203 
204 #ifdef CONFIG_NUMA
205 extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
206 extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
207 
208 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
209 {
210 	if (__builtin_constant_p(size)) {
211 		int i = 0;
212 #define CACHE(x) \
213 		if (size <= x) \
214 			goto found; \
215 		else \
216 			i++;
217 #include "kmalloc_sizes.h"
218 #undef CACHE
219 		{
220 			extern void __you_cannot_kmalloc_that_much(void);
221 			__you_cannot_kmalloc_that_much();
222 		}
223 found:
224 		return kmem_cache_alloc_node((flags & GFP_DMA) ?
225 			malloc_sizes[i].cs_dmacachep :
226 			malloc_sizes[i].cs_cachep, flags, node);
227 	}
228 	return __kmalloc_node(size, flags, node);
229 }
230 
231 /*
232  * kmalloc_node_track_caller is a special version of kmalloc_node that
233  * records the calling function of the routine calling it for slab leak
234  * tracking instead of just the calling function (confusing, eh?).
235  * It's useful when the call to kmalloc_node comes from a widely-used
236  * standard allocator where we care about the real place the memory
237  * allocation request comes from.
238  */
239 #ifndef CONFIG_DEBUG_SLAB
240 #define kmalloc_node_track_caller(size, flags, node) \
241 	__kmalloc_node(size, flags, node)
242 #else
243 extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, void *);
244 #define kmalloc_node_track_caller(size, flags, node) \
245 	__kmalloc_node_track_caller(size, flags, node, \
246 			__builtin_return_address(0))
247 #endif
248 #else /* CONFIG_NUMA */
249 static inline void *kmem_cache_alloc_node(struct kmem_cache *cachep,
250 					gfp_t flags, int node)
251 {
252 	return kmem_cache_alloc(cachep, flags);
253 }
254 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
255 {
256 	return kmalloc(size, flags);
257 }
258 
259 #define kmalloc_node_track_caller(size, flags, node) \
260 	kmalloc_track_caller(size, flags)
261 #endif
262 
263 extern int FASTCALL(kmem_cache_reap(int));
264 extern int FASTCALL(kmem_ptr_validate(struct kmem_cache *cachep, void *ptr));
265 
266 #else /* CONFIG_SLOB */
267 
268 /* SLOB allocator routines */
269 
270 void kmem_cache_init(void);
271 struct kmem_cache *kmem_cache_create(const char *c, size_t, size_t,
272 	unsigned long,
273 	void (*)(void *, struct kmem_cache *, unsigned long),
274 	void (*)(void *, struct kmem_cache *, unsigned long));
275 void kmem_cache_destroy(struct kmem_cache *c);
276 void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags);
277 void *kmem_cache_zalloc(struct kmem_cache *, gfp_t);
278 void kmem_cache_free(struct kmem_cache *c, void *b);
279 const char *kmem_cache_name(struct kmem_cache *);
280 void *kmalloc(size_t size, gfp_t flags);
281 void *__kzalloc(size_t size, gfp_t flags);
282 void kfree(const void *m);
283 unsigned int ksize(const void *m);
284 unsigned int kmem_cache_size(struct kmem_cache *c);
285 
286 static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
287 {
288 	return __kzalloc(n * size, flags);
289 }
290 
291 #define kmem_cache_shrink(d) (0)
292 #define kmem_cache_reap(a)
293 #define kmem_ptr_validate(a, b) (0)
294 #define kmem_cache_alloc_node(c, f, n) kmem_cache_alloc(c, f)
295 #define kmalloc_node(s, f, n) kmalloc(s, f)
296 #define kzalloc(s, f) __kzalloc(s, f)
297 #define kmalloc_track_caller kmalloc
298 
299 #define kmalloc_node_track_caller kmalloc_node
300 
301 #endif /* CONFIG_SLOB */
302 
303 #endif	/* __KERNEL__ */
304 
305 #endif	/* _LINUX_SLAB_H */
306