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 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; 172 void *result = (unlikely(object > last_object)) ? last_object : object; 173 174 result = fixup_red_left(cache, result); 175 return result; 176 } 177 178 /* 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 { 189 if (is_kfence_address(obj)) 190 return 0; 191 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 */ 200