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 #include <linux/local_lock.h> 14 15 enum stat_item { 16 ALLOC_FASTPATH, /* Allocation from cpu slab */ 17 ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */ 18 FREE_FASTPATH, /* Free to cpu slab */ 19 FREE_SLOWPATH, /* Freeing not to cpu slab */ 20 FREE_FROZEN, /* Freeing to frozen slab */ 21 FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */ 22 FREE_REMOVE_PARTIAL, /* Freeing removes last object */ 23 ALLOC_FROM_PARTIAL, /* Cpu slab acquired from node partial list */ 24 ALLOC_SLAB, /* Cpu slab acquired from page allocator */ 25 ALLOC_REFILL, /* Refill cpu slab from slab freelist */ 26 ALLOC_NODE_MISMATCH, /* Switching cpu slab */ 27 FREE_SLAB, /* Slab freed to the page allocator */ 28 CPUSLAB_FLUSH, /* Abandoning of the cpu slab */ 29 DEACTIVATE_FULL, /* Cpu slab was full when deactivated */ 30 DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */ 31 DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */ 32 DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */ 33 DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */ 34 DEACTIVATE_BYPASS, /* Implicit deactivation */ 35 ORDER_FALLBACK, /* Number of times fallback was necessary */ 36 CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */ 37 CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */ 38 CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */ 39 CPU_PARTIAL_FREE, /* Refill cpu partial on free */ 40 CPU_PARTIAL_NODE, /* Refill cpu partial from node partial */ 41 CPU_PARTIAL_DRAIN, /* Drain cpu partial to node partial */ 42 NR_SLUB_STAT_ITEMS }; 43 44 /* 45 * When changing the layout, make sure freelist and tid are still compatible 46 * with this_cpu_cmpxchg_double() alignment requirements. 47 */ 48 struct kmem_cache_cpu { 49 void **freelist; /* Pointer to next available object */ 50 unsigned long tid; /* Globally unique transaction id */ 51 struct page *page; /* The slab from which we are allocating */ 52 #ifdef CONFIG_SLUB_CPU_PARTIAL 53 struct page *partial; /* Partially allocated frozen slabs */ 54 #endif 55 local_lock_t lock; /* Protects the fields above */ 56 #ifdef CONFIG_SLUB_STATS 57 unsigned stat[NR_SLUB_STAT_ITEMS]; 58 #endif 59 }; 60 61 #ifdef CONFIG_SLUB_CPU_PARTIAL 62 #define slub_percpu_partial(c) ((c)->partial) 63 64 #define slub_set_percpu_partial(c, p) \ 65 ({ \ 66 slub_percpu_partial(c) = (p)->next; \ 67 }) 68 69 #define slub_percpu_partial_read_once(c) READ_ONCE(slub_percpu_partial(c)) 70 #else 71 #define slub_percpu_partial(c) NULL 72 73 #define slub_set_percpu_partial(c, p) 74 75 #define slub_percpu_partial_read_once(c) NULL 76 #endif // CONFIG_SLUB_CPU_PARTIAL 77 78 /* 79 * Word size structure that can be atomically updated or read and that 80 * contains both the order and the number of objects that a slab of the 81 * given order would contain. 82 */ 83 struct kmem_cache_order_objects { 84 unsigned int x; 85 }; 86 87 /* 88 * Slab cache management. 89 */ 90 struct kmem_cache { 91 struct kmem_cache_cpu __percpu *cpu_slab; 92 /* Used for retrieving partial slabs, etc. */ 93 slab_flags_t flags; 94 unsigned long min_partial; 95 unsigned int size; /* The size of an object including metadata */ 96 unsigned int object_size;/* The size of an object without metadata */ 97 struct reciprocal_value reciprocal_size; 98 unsigned int offset; /* Free pointer offset */ 99 #ifdef CONFIG_SLUB_CPU_PARTIAL 100 /* Number of per cpu partial objects to keep around */ 101 unsigned int cpu_partial; 102 /* Number of per cpu partial pages to keep around */ 103 unsigned int cpu_partial_pages; 104 #endif 105 struct kmem_cache_order_objects oo; 106 107 /* Allocation and freeing of slabs */ 108 struct kmem_cache_order_objects max; 109 struct kmem_cache_order_objects min; 110 gfp_t allocflags; /* gfp flags to use on each alloc */ 111 int refcount; /* Refcount for slab cache destroy */ 112 void (*ctor)(void *); 113 unsigned int inuse; /* Offset to metadata */ 114 unsigned int align; /* Alignment */ 115 unsigned int red_left_pad; /* Left redzone padding size */ 116 const char *name; /* Name (only for display!) */ 117 struct list_head list; /* List of slab caches */ 118 #ifdef CONFIG_SYSFS 119 struct kobject kobj; /* For sysfs */ 120 #endif 121 #ifdef CONFIG_SLAB_FREELIST_HARDENED 122 unsigned long random; 123 #endif 124 125 #ifdef CONFIG_NUMA 126 /* 127 * Defragmentation by allocating from a remote node. 128 */ 129 unsigned int remote_node_defrag_ratio; 130 #endif 131 132 #ifdef CONFIG_SLAB_FREELIST_RANDOM 133 unsigned int *random_seq; 134 #endif 135 136 #ifdef CONFIG_KASAN 137 struct kasan_cache kasan_info; 138 #endif 139 140 unsigned int useroffset; /* Usercopy region offset */ 141 unsigned int usersize; /* Usercopy region size */ 142 143 struct kmem_cache_node *node[MAX_NUMNODES]; 144 }; 145 146 #ifdef CONFIG_SYSFS 147 #define SLAB_SUPPORTS_SYSFS 148 void sysfs_slab_unlink(struct kmem_cache *); 149 void sysfs_slab_release(struct kmem_cache *); 150 #else 151 static inline void sysfs_slab_unlink(struct kmem_cache *s) 152 { 153 } 154 static inline void sysfs_slab_release(struct kmem_cache *s) 155 { 156 } 157 #endif 158 159 void object_err(struct kmem_cache *s, struct page *page, 160 u8 *object, char *reason); 161 162 void *fixup_red_left(struct kmem_cache *s, void *p); 163 164 static inline void *nearest_obj(struct kmem_cache *cache, struct page *page, 165 void *x) { 166 void *object = x - (x - page_address(page)) % cache->size; 167 void *last_object = page_address(page) + 168 (page->objects - 1) * cache->size; 169 void *result = (unlikely(object > last_object)) ? last_object : object; 170 171 result = fixup_red_left(cache, result); 172 return result; 173 } 174 175 /* Determine object index from a given position */ 176 static inline unsigned int __obj_to_index(const struct kmem_cache *cache, 177 void *addr, void *obj) 178 { 179 return reciprocal_divide(kasan_reset_tag(obj) - addr, 180 cache->reciprocal_size); 181 } 182 183 static inline unsigned int obj_to_index(const struct kmem_cache *cache, 184 const struct page *page, void *obj) 185 { 186 if (is_kfence_address(obj)) 187 return 0; 188 return __obj_to_index(cache, page_address(page), obj); 189 } 190 191 static inline int objs_per_slab_page(const struct kmem_cache *cache, 192 const struct page *page) 193 { 194 return page->objects; 195 } 196 #endif /* _LINUX_SLUB_DEF_H */ 197