[mirror_ubuntu-jammy-kernel.git] / include / linux / slub_def.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_SLUB_DEF_H
#define _LINUX_SLUB_DEF_H

/*
 * SLUB : A Slab allocator without object queues.
 *
 * (C) 2007 SGI, Christoph Lameter
 */
#include <linux/kfence.h>
#include <linux/kobject.h>
#include <linux/reciprocal_div.h>

enum stat_item {
	ALLOC_FASTPATH,		/* Allocation from cpu slab */
	ALLOC_SLOWPATH,		/* Allocation by getting a new cpu slab */
	FREE_FASTPATH,		/* Free to cpu slab */
	FREE_SLOWPATH,		/* Freeing not to cpu slab */
	FREE_FROZEN,		/* Freeing to frozen slab */
	FREE_ADD_PARTIAL,	/* Freeing moves slab to partial list */
	FREE_REMOVE_PARTIAL,	/* Freeing removes last object */
	ALLOC_FROM_PARTIAL,	/* Cpu slab acquired from node partial list */
	ALLOC_SLAB,		/* Cpu slab acquired from page allocator */
	ALLOC_REFILL,		/* Refill cpu slab from slab freelist */
	ALLOC_NODE_MISMATCH,	/* Switching cpu slab */
	FREE_SLAB,		/* Slab freed to the page allocator */
	CPUSLAB_FLUSH,		/* Abandoning of the cpu slab */
	DEACTIVATE_FULL,	/* Cpu slab was full when deactivated */
	DEACTIVATE_EMPTY,	/* Cpu slab was empty when deactivated */
	DEACTIVATE_TO_HEAD,	/* Cpu slab was moved to the head of partials */
	DEACTIVATE_TO_TAIL,	/* Cpu slab was moved to the tail of partials */
	DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
	DEACTIVATE_BYPASS,	/* Implicit deactivation */
	ORDER_FALLBACK,		/* Number of times fallback was necessary */
	CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
	CMPXCHG_DOUBLE_FAIL,	/* Number of times that cmpxchg double did not match */
	CPU_PARTIAL_ALLOC,	/* Used cpu partial on alloc */
	CPU_PARTIAL_FREE,	/* Refill cpu partial on free */
	CPU_PARTIAL_NODE,	/* Refill cpu partial from node partial */
	CPU_PARTIAL_DRAIN,	/* Drain cpu partial to node partial */
	NR_SLUB_STAT_ITEMS };

struct kmem_cache_cpu {
	void **freelist;	/* Pointer to next available object */
	unsigned long tid;	/* Globally unique transaction id */
	struct page *page;	/* The slab from which we are allocating */
#ifdef CONFIG_SLUB_CPU_PARTIAL
	struct page *partial;	/* Partially allocated frozen slabs */
#endif
#ifdef CONFIG_SLUB_STATS
	unsigned stat[NR_SLUB_STAT_ITEMS];
#endif
};

#ifdef CONFIG_SLUB_CPU_PARTIAL
#define slub_percpu_partial(c)		((c)->partial)

#define slub_set_percpu_partial(c, p)		\
({						\
	slub_percpu_partial(c) = (p)->next;	\
})

#define slub_percpu_partial_read_once(c)     READ_ONCE(slub_percpu_partial(c))
#else
#define slub_percpu_partial(c)			NULL

#define slub_set_percpu_partial(c, p)

#define slub_percpu_partial_read_once(c)	NULL
#endif // CONFIG_SLUB_CPU_PARTIAL

/*
 * Word size structure that can be atomically updated or read and that
 * contains both the order and the number of objects that a slab of the
 * given order would contain.
 */
struct kmem_cache_order_objects {
	unsigned int x;
};

/*
 * Slab cache management.
 */
struct kmem_cache {
	struct kmem_cache_cpu __percpu *cpu_slab;
	/* Used for retrieving partial slabs, etc. */
	slab_flags_t flags;
	unsigned long min_partial;
	unsigned int size;	/* The size of an object including metadata */
	unsigned int object_size;/* The size of an object without metadata */
	struct reciprocal_value reciprocal_size;
	unsigned int offset;	/* Free pointer offset */
#ifdef CONFIG_SLUB_CPU_PARTIAL
	/* Number of per cpu partial objects to keep around */
	unsigned int cpu_partial;
#endif
	struct kmem_cache_order_objects oo;

	/* Allocation and freeing of slabs */
	struct kmem_cache_order_objects max;
	struct kmem_cache_order_objects min;
	gfp_t allocflags;	/* gfp flags to use on each alloc */
	int refcount;		/* Refcount for slab cache destroy */
	void (*ctor)(void *);
	unsigned int inuse;		/* Offset to metadata */
	unsigned int align;		/* Alignment */
	unsigned int red_left_pad;	/* Left redzone padding size */
	const char *name;	/* Name (only for display!) */
	struct list_head list;	/* List of slab caches */
#ifdef CONFIG_SYSFS
	struct kobject kobj;	/* For sysfs */
#endif
#ifdef CONFIG_SLAB_FREELIST_HARDENED
	unsigned long random;
#endif

#ifdef CONFIG_NUMA
	/*
	 * Defragmentation by allocating from a remote node.
	 */
	unsigned int remote_node_defrag_ratio;
#endif

#ifdef CONFIG_SLAB_FREELIST_RANDOM
	unsigned int *random_seq;
#endif

#ifdef CONFIG_KASAN
	struct kasan_cache kasan_info;
#endif

	unsigned int useroffset;	/* Usercopy region offset */
	unsigned int usersize;		/* Usercopy region size */

	struct kmem_cache_node *node[MAX_NUMNODES];
};

#ifdef CONFIG_SLUB_CPU_PARTIAL
#define slub_cpu_partial(s)		((s)->cpu_partial)
#define slub_set_cpu_partial(s, n)		\
({						\
	slub_cpu_partial(s) = (n);		\
})
#else
#define slub_cpu_partial(s)		(0)
#define slub_set_cpu_partial(s, n)
#endif /* CONFIG_SLUB_CPU_PARTIAL */

#ifdef CONFIG_SYSFS
#define SLAB_SUPPORTS_SYSFS
void sysfs_slab_unlink(struct kmem_cache *);
void sysfs_slab_release(struct kmem_cache *);
#else
static inline void sysfs_slab_unlink(struct kmem_cache *s)
{
}
static inline void sysfs_slab_release(struct kmem_cache *s)
{
}
#endif

void object_err(struct kmem_cache *s, struct page *page,
		u8 *object, char *reason);

void *fixup_red_left(struct kmem_cache *s, void *p);

static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
				void *x) {
	void *object = x - (x - page_address(page)) % cache->size;
	void *last_object = page_address(page) +
		(page->objects - 1) * cache->size;
	void *result = (unlikely(object > last_object)) ? last_object : object;

	result = fixup_red_left(cache, result);
	return result;
}

/* Determine object index from a given position */
static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
					  void *addr, void *obj)
{
	return reciprocal_divide(kasan_reset_tag(obj) - addr,
				 cache->reciprocal_size);
}

static inline unsigned int obj_to_index(const struct kmem_cache *cache,
					const struct page *page, void *obj)
{
	if (is_kfence_address(obj))
		return 0;
	return __obj_to_index(cache, page_address(page), obj);
}

static inline int objs_per_slab_page(const struct kmem_cache *cache,
				     const struct page *page)
{
	return page->objects;
}
#endif /* _LINUX_SLUB_DEF_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
81819f0f CL	2	#ifndef _LINUX_SLUB_DEF_H
	3	#define _LINUX_SLUB_DEF_H
	4
	5	/*
	6	* SLUB : A Slab allocator without object queues.
	7	*
cde53535	8	* (C) 2007 SGI, Christoph Lameter
81819f0f	9	*/
b89fb5ef	10	#include <linux/kfence.h>
81819f0f	11	#include <linux/kobject.h>
4138fdfc	12	#include <linux/reciprocal_div.h>
81819f0f	13
8ff12cfc CL	14	enum stat_item {
	15	ALLOC_FASTPATH, /* Allocation from cpu slab */
	16	ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
a941f836	17	FREE_FASTPATH, /* Free to cpu slab */
8ff12cfc CL	18	FREE_SLOWPATH, /* Freeing not to cpu slab */
	19	FREE_FROZEN, /* Freeing to frozen slab */
	20	FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */
	21	FREE_REMOVE_PARTIAL, /* Freeing removes last object */
8028dcea	22	ALLOC_FROM_PARTIAL, /* Cpu slab acquired from node partial list */
8ff12cfc CL	23	ALLOC_SLAB, /* Cpu slab acquired from page allocator */
8ff12cfc CL	24	ALLOC_REFILL, /* Refill cpu slab from slab freelist */
e36a2652	25	ALLOC_NODE_MISMATCH, /* Switching cpu slab */
8ff12cfc CL	26	FREE_SLAB, /* Slab freed to the page allocator */
	27	CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
	28	DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
	29	DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
	30	DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
	31	DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
	32	DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
03e404af	33	DEACTIVATE_BYPASS, /* Implicit deactivation */
65c3376a	34	ORDER_FALLBACK, /* Number of times fallback was necessary */
4fdccdfb	35	CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
b789ef51	36	CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
49e22585	37	CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
8028dcea AS	38	CPU_PARTIAL_FREE, /* Refill cpu partial on free */
	39	CPU_PARTIAL_NODE, /* Refill cpu partial from node partial */
	40	CPU_PARTIAL_DRAIN, /* Drain cpu partial to node partial */
8ff12cfc CL	41	NR_SLUB_STAT_ITEMS };
8ff12cfc CL	42
dfb4f096	43	struct kmem_cache_cpu {
8a5ec0ba	44	void *freelist; / Pointer to next available object */
8a5ec0ba	45	unsigned long tid; /* Globally unique transaction id */
da89b79e	46	struct page page; / The slab from which we are allocating */
a93cf07b	47	#ifdef CONFIG_SLUB_CPU_PARTIAL
49e22585	48	struct page partial; / Partially allocated frozen slabs */
a93cf07b	49	#endif
8ff12cfc CL	50	#ifdef CONFIG_SLUB_STATS
	51	unsigned stat[NR_SLUB_STAT_ITEMS];
	52	#endif
4c93c355	53	};
dfb4f096	54
a93cf07b WY	55	#ifdef CONFIG_SLUB_CPU_PARTIAL
	56	#define slub_percpu_partial(c) ((c)->partial)
	57
	58	#define slub_set_percpu_partial(c, p) \
	59	({ \
	60	slub_percpu_partial(c) = (p)->next; \
	61	})
	62
	63	#define slub_percpu_partial_read_once(c) READ_ONCE(slub_percpu_partial(c))
	64	#else
	65	#define slub_percpu_partial(c) NULL
	66
	67	#define slub_set_percpu_partial(c, p)
	68
	69	#define slub_percpu_partial_read_once(c) NULL
	70	#endif // CONFIG_SLUB_CPU_PARTIAL
	71
834f3d11 CL	72	/*
	73	* Word size structure that can be atomically updated or read and that
	74	* contains both the order and the number of objects that a slab of the
	75	* given order would contain.
	76	*/
	77	struct kmem_cache_order_objects {
19af27af	78	unsigned int x;
834f3d11 CL	79	};
834f3d11 CL	80
81819f0f CL	81	/*
	82	* Slab cache management.
	83	*/
	84	struct kmem_cache {
1b5ad248	85	struct kmem_cache_cpu __percpu *cpu_slab;
de810f49	86	/* Used for retrieving partial slabs, etc. */
d50112ed	87	slab_flags_t flags;
1a757fe5	88	unsigned long min_partial;
de810f49 TH	89	unsigned int size; /* The size of an object including metadata */
de810f49 TH	90	unsigned int object_size;/* The size of an object without metadata */
4138fdfc	91	struct reciprocal_value reciprocal_size;
de810f49	92	unsigned int offset; /* Free pointer offset */
e6d0e1dc	93	#ifdef CONFIG_SLUB_CPU_PARTIAL
e5d9998f AD	94	/* Number of per cpu partial objects to keep around */
e5d9998f AD	95	unsigned int cpu_partial;
e6d0e1dc	96	#endif
834f3d11	97	struct kmem_cache_order_objects oo;
81819f0f	98
81819f0f	99	/* Allocation and freeing of slabs */
205ab99d	100	struct kmem_cache_order_objects max;
65c3376a	101	struct kmem_cache_order_objects min;
b7a49f0d	102	gfp_t allocflags; /* gfp flags to use on each alloc */
81819f0f	103	int refcount; /* Refcount for slab cache destroy */
51cc5068	104	void (ctor)(void );
52ee6d74	105	unsigned int inuse; /* Offset to metadata */
3a3791ec	106	unsigned int align; /* Alignment */
2ca6d39b	107	unsigned int red_left_pad; /* Left redzone padding size */
81819f0f CL	108	const char name; / Name (only for display!) */
81819f0f CL	109	struct list_head list; /* List of slab caches */
ab4d5ed5	110	#ifdef CONFIG_SYSFS
81819f0f	111	struct kobject kobj; /* For sysfs */
0c710013	112	#endif
2482ddec KC	113	#ifdef CONFIG_SLAB_FREELIST_HARDENED
	114	unsigned long random;
	115	#endif
	116
81819f0f	117	#ifdef CONFIG_NUMA
9824601e CL	118	/*
	119	* Defragmentation by allocating from a remote node.
	120	*/
eb7235eb	121	unsigned int remote_node_defrag_ratio;
81819f0f	122	#endif
210e7a43 TG	123
	124	#ifdef CONFIG_SLAB_FREELIST_RANDOM
	125	unsigned int *random_seq;
	126	#endif
	127
80a9201a AP	128	#ifdef CONFIG_KASAN
	129	struct kasan_cache kasan_info;
	130	#endif
	131
7bbdb81e AD	132	unsigned int useroffset; /* Usercopy region offset */
7bbdb81e AD	133	unsigned int usersize; /* Usercopy region size */
8eb8284b	134
7340cc84	135	struct kmem_cache_node *node[MAX_NUMNODES];
81819f0f CL	136	};
81819f0f CL	137
e6d0e1dc WY	138	#ifdef CONFIG_SLUB_CPU_PARTIAL
	139	#define slub_cpu_partial(s) ((s)->cpu_partial)
	140	#define slub_set_cpu_partial(s, n) \
	141	({ \
	142	slub_cpu_partial(s) = (n); \
	143	})
	144	#else
	145	#define slub_cpu_partial(s) (0)
	146	#define slub_set_cpu_partial(s, n)
de810f49	147	#endif /* CONFIG_SLUB_CPU_PARTIAL */
e6d0e1dc	148
41a21285 CL	149	#ifdef CONFIG_SYSFS
41a21285 CL	150	#define SLAB_SUPPORTS_SYSFS
d50d82fa	151	void sysfs_slab_unlink(struct kmem_cache *);
bf5eb3de	152	void sysfs_slab_release(struct kmem_cache *);
41a21285	153	#else
d50d82fa MP	154	static inline void sysfs_slab_unlink(struct kmem_cache *s)
	155	{
	156	}
bf5eb3de	157	static inline void sysfs_slab_release(struct kmem_cache *s)
41a21285 CL	158	{
	159	}
	160	#endif
	161
75c66def AR	162	void object_err(struct kmem_cache s, struct page page,
	163	u8 object, char reason);
	164
c146a2b9 AP	165	void fixup_red_left(struct kmem_cache s, void *p);
c146a2b9 AP	166
7ed2f9e6 AP	167	static inline void nearest_obj(struct kmem_cache cache, struct page *page,
	168	void *x) {
	169	void *object = x - (x - page_address(page)) % cache->size;
	170	void *last_object = page_address(page) +
	171	(page->objects - 1) * cache->size;
c146a2b9 AP	172	void *result = (unlikely(object > last_object)) ? last_object : object;
	173
	174	result = fixup_red_left(cache, result);
	175	return result;
7ed2f9e6 AP	176	}
7ed2f9e6 AP	177
4138fdfc RG	178	/* Determine object index from a given position */
	179	static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
	180	void addr, void obj)
	181	{
	182	return reciprocal_divide(kasan_reset_tag(obj) - addr,
	183	cache->reciprocal_size);
	184	}
	185
	186	static inline unsigned int obj_to_index(const struct kmem_cache *cache,
	187	const struct page page, void obj)
	188	{
b89fb5ef AP	189	if (is_kfence_address(obj))
b89fb5ef AP	190	return 0;
4138fdfc RG	191	return __obj_to_index(cache, page_address(page), obj);
	192	}
	193
286e04b8 RG	194	static inline int objs_per_slab_page(const struct kmem_cache *cache,
	195	const struct page *page)
	196	{
	197	return page->objects;
	198	}
81819f0f	199	#endif /* _LINUX_SLUB_DEF_H */