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1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_SLUB_DEF_H
3 : #define _LINUX_SLUB_DEF_H
4 :
5 : /*
6 : * SLUB : A Slab allocator without object queues.
7 : *
8 : * (C) 2007 SGI, Christoph Lameter
9 : */
10 : #include <linux/kfence.h>
11 : #include <linux/kobject.h>
12 : #include <linux/reciprocal_div.h>
13 :
14 : enum stat_item {
15 : ALLOC_FASTPATH, /* Allocation from cpu slab */
16 : ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
17 : FREE_FASTPATH, /* Free to cpu slab */
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 */
22 : ALLOC_FROM_PARTIAL, /* Cpu slab acquired from node partial list */
23 : ALLOC_SLAB, /* Cpu slab acquired from page allocator */
24 : ALLOC_REFILL, /* Refill cpu slab from slab freelist */
25 : ALLOC_NODE_MISMATCH, /* Switching cpu slab */
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 */
33 : DEACTIVATE_BYPASS, /* Implicit deactivation */
34 : ORDER_FALLBACK, /* Number of times fallback was necessary */
35 : CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
36 : CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
37 : CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
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 */
41 : NR_SLUB_STAT_ITEMS };
42 :
43 : struct kmem_cache_cpu {
44 : void **freelist; /* Pointer to next available object */
45 : unsigned long tid; /* Globally unique transaction id */
46 : struct page *page; /* The slab from which we are allocating */
47 : #ifdef CONFIG_SLUB_CPU_PARTIAL
48 : struct page *partial; /* Partially allocated frozen slabs */
49 : #endif
50 : #ifdef CONFIG_SLUB_STATS
51 : unsigned stat[NR_SLUB_STAT_ITEMS];
52 : #endif
53 : };
54 :
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 :
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 {
78 : unsigned int x;
79 : };
80 :
81 : /*
82 : * Slab cache management.
83 : */
84 : struct kmem_cache {
85 : struct kmem_cache_cpu __percpu *cpu_slab;
86 : /* Used for retrieving partial slabs, etc. */
87 : slab_flags_t flags;
88 : unsigned long min_partial;
89 : unsigned int size; /* The size of an object including metadata */
90 : unsigned int object_size;/* The size of an object without metadata */
91 : struct reciprocal_value reciprocal_size;
92 : unsigned int offset; /* Free pointer offset */
93 : #ifdef CONFIG_SLUB_CPU_PARTIAL
94 : /* Number of per cpu partial objects to keep around */
95 : unsigned int cpu_partial;
96 : #endif
97 : struct kmem_cache_order_objects oo;
98 :
99 : /* Allocation and freeing of slabs */
100 : struct kmem_cache_order_objects max;
101 : struct kmem_cache_order_objects min;
102 : gfp_t allocflags; /* gfp flags to use on each alloc */
103 : int refcount; /* Refcount for slab cache destroy */
104 : void (*ctor)(void *);
105 : unsigned int inuse; /* Offset to metadata */
106 : unsigned int align; /* Alignment */
107 : unsigned int red_left_pad; /* Left redzone padding size */
108 : const char *name; /* Name (only for display!) */
109 : struct list_head list; /* List of slab caches */
110 : #ifdef CONFIG_SYSFS
111 : struct kobject kobj; /* For sysfs */
112 : #endif
113 : #ifdef CONFIG_SLAB_FREELIST_HARDENED
114 : unsigned long random;
115 : #endif
116 :
117 : #ifdef CONFIG_NUMA
118 : /*
119 : * Defragmentation by allocating from a remote node.
120 : */
121 : unsigned int remote_node_defrag_ratio;
122 : #endif
123 :
124 : #ifdef CONFIG_SLAB_FREELIST_RANDOM
125 : unsigned int *random_seq;
126 : #endif
127 :
128 : #ifdef CONFIG_KASAN
129 : struct kasan_cache kasan_info;
130 : #endif
131 :
132 : unsigned int useroffset; /* Usercopy region offset */
133 : unsigned int usersize; /* Usercopy region size */
134 :
135 : struct kmem_cache_node *node[MAX_NUMNODES];
136 : };
137 :
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)
147 : #endif /* CONFIG_SLUB_CPU_PARTIAL */
148 :
149 : #ifdef CONFIG_SYSFS
150 : #define SLAB_SUPPORTS_SYSFS
151 : void sysfs_slab_unlink(struct kmem_cache *);
152 : void sysfs_slab_release(struct kmem_cache *);
153 : #else
154 : static inline void sysfs_slab_unlink(struct kmem_cache *s)
155 : {
156 : }
157 : static inline void sysfs_slab_release(struct kmem_cache *s)
158 : {
159 : }
160 : #endif
161 :
162 : void object_err(struct kmem_cache *s, struct page *page,
163 : u8 *object, char *reason);
164 :
165 : void *fixup_red_left(struct kmem_cache *s, void *p);
166 :
167 2036703 : static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
168 : void *x) {
169 2036703 : void *object = x - (x - page_address(page)) % cache->size;
170 2036703 : void *last_object = page_address(page) +
171 2036703 : (page->objects - 1) * cache->size;
172 2036703 : void *result = (unlikely(object > last_object)) ? last_object : object;
173 :
174 2036703 : result = fixup_red_left(cache, result);
175 2036477 : return result;
176 : }
177 :
178 : /* Determine object index from a given position */
179 0 : static inline unsigned int __obj_to_index(const struct kmem_cache *cache,
180 : void *addr, void *obj)
181 : {
182 0 : return reciprocal_divide(kasan_reset_tag(obj) - addr,
183 : cache->reciprocal_size);
184 : }
185 :
186 0 : static inline unsigned int obj_to_index(const struct kmem_cache *cache,
187 : const struct page *page, void *obj)
188 : {
189 0 : if (is_kfence_address(obj))
190 : return 0;
191 0 : return __obj_to_index(cache, page_address(page), obj);
192 : }
193 :
194 : static inline int objs_per_slab_page(const struct kmem_cache *cache,
195 : const struct page *page)
196 : {
197 : return page->objects;
198 : }
199 : #endif /* _LINUX_SLUB_DEF_H */
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