/* SPDX-License-Identifier: GPL-2.0 */ #ifndef MM_SLAB_H #define MM_SLAB_H /* * Internal slab definitions */ #ifdef CONFIG_SLOB /* * Common fields provided in kmem_cache by all slab allocators * This struct is either used directly by the allocator (SLOB) * or the allocator must include definitions for all fields * provided in kmem_cache_common in their definition of kmem_cache. * * Once we can do anonymous structs (C11 standard) we could put a * anonymous struct definition in these allocators so that the * separate allocations in the kmem_cache structure of SLAB and * SLUB is no longer needed. */ struct kmem_cache { unsigned int object_size;/* The original size of the object */ unsigned int size; /* The aligned/padded/added on size */ unsigned int align; /* Alignment as calculated */ slab_flags_t flags; /* Active flags on the slab */ unsigned int useroffset;/* Usercopy region offset */ unsigned int usersize; /* Usercopy region size */ const char *name; /* Slab name for sysfs */ int refcount; /* Use counter */ void (*ctor)(void *); /* Called on object slot creation */ struct list_head list; /* List of all slab caches on the system */ }; #endif /* CONFIG_SLOB */ #ifdef CONFIG_SLAB #include <linux/slab_def.h> #endif #ifdef CONFIG_SLUB #include <linux/slub_def.h> #endif #include <linux/memcontrol.h> #include <linux/fault-inject.h> #include <linux/kasan.h> #include <linux/kmemleak.h> #include <linux/random.h> #include <linux/sched/mm.h> /* * State of the slab allocator. * * This is used to describe the states of the allocator during bootup. * Allocators use this to gradually bootstrap themselves. Most allocators * have the problem that the structures used for managing slab caches are * allocated from slab caches themselves. */ enum slab_state { DOWN, /* No slab functionality yet */ PARTIAL, /* SLUB: kmem_cache_node available */ PARTIAL_NODE, /* SLAB: kmalloc size for node struct available */ UP, /* Slab caches usable but not all extras yet */ FULL /* Everything is working */ }; extern enum slab_state slab_state; /* The slab cache mutex protects the management structures during changes */ extern struct mutex slab_mutex; /* The list of all slab caches on the system */ extern struct list_head slab_caches; /* The slab cache that manages slab cache information */ extern struct kmem_cache *kmem_cache; /* A table of kmalloc cache names and sizes */ extern const struct kmalloc_info_struct { const char *name[NR_KMALLOC_TYPES]; unsigned int size; } kmalloc_info[]; #ifndef CONFIG_SLOB /* Kmalloc array related functions */ void setup_kmalloc_cache_index_table(void); void create_kmalloc_caches(slab_flags_t); /* Find the kmalloc slab corresponding for a certain size */ struct kmem_cache *kmalloc_slab(size_t, gfp_t); #endif gfp_t kmalloc_fix_flags(gfp_t flags); /* Functions provided by the slab allocators */ int __kmem_cache_create(struct kmem_cache *, slab_flags_t flags); struct kmem_cache *create_kmalloc_cache(const char *name, unsigned int size, slab_flags_t flags, unsigned int useroffset, unsigned int usersize); extern void create_boot_cache(struct kmem_cache *, const char *name, unsigned int size, slab_flags_t flags, unsigned int useroffset, unsigned int usersize); int slab_unmergeable(struct kmem_cache *s); struct kmem_cache *find_mergeable(unsigned size, unsigned align, slab_flags_t flags, const char *name, void (*ctor)(void *)); #ifndef CONFIG_SLOB struct kmem_cache * __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, slab_flags_t flags, void (*ctor)(void *)); slab_flags_t kmem_cache_flags(unsigned int object_size, slab_flags_t flags, const char *name); #else static inline struct kmem_cache * __kmem_cache_alias(const char *name, unsigned int size, unsigned int align, slab_flags_t flags, void (*ctor)(void *)) { return NULL; } static inline slab_flags_t kmem_cache_flags(unsigned int object_size, slab_flags_t flags, const char *name) { return flags; } #endif /* Legal flag mask for kmem_cache_create(), for various configurations */ #define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | \ SLAB_CACHE_DMA32 | SLAB_PANIC | \ SLAB_TYPESAFE_BY_RCU | SLAB_DEBUG_OBJECTS ) #if defined(CONFIG_DEBUG_SLAB) #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER) #elif defined(CONFIG_SLUB_DEBUG) #define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ SLAB_TRACE | SLAB_CONSISTENCY_CHECKS) #else #define SLAB_DEBUG_FLAGS (0) #endif #if defined(CONFIG_SLAB) #define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \ SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | \ SLAB_ACCOUNT) #elif defined(CONFIG_SLUB) #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ SLAB_TEMPORARY | SLAB_ACCOUNT) #else #define SLAB_CACHE_FLAGS (0) #endif /* Common flags available with current configuration */ #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) /* Common flags permitted for kmem_cache_create */ #define SLAB_FLAGS_PERMITTED (SLAB_CORE_FLAGS | \ SLAB_RED_ZONE | \ SLAB_POISON | \ SLAB_STORE_USER | \ SLAB_TRACE | \ SLAB_CONSISTENCY_CHECKS | \ SLAB_MEM_SPREAD | \ SLAB_NOLEAKTRACE | \ SLAB_RECLAIM_ACCOUNT | \ SLAB_TEMPORARY | \ SLAB_ACCOUNT) bool __kmem_cache_empty(struct kmem_cache *); int __kmem_cache_shutdown(struct kmem_cache *); void __kmem_cache_release(struct kmem_cache *); int __kmem_cache_shrink(struct kmem_cache *); void slab_kmem_cache_release(struct kmem_cache *); struct seq_file; struct file; struct slabinfo { unsigned long active_objs; unsigned long num_objs; unsigned long active_slabs; unsigned long num_slabs; unsigned long shared_avail; unsigned int limit; unsigned int batchcount; unsigned int shared; unsigned int objects_per_slab; unsigned int cache_order; }; void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo); void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s); ssize_t slabinfo_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos); /* * Generic implementation of bulk operations * These are useful for situations in which the allocator cannot * perform optimizations. In that case segments of the object listed * may be allocated or freed using these operations. */ void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **); int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **); static inline enum node_stat_item cache_vmstat_idx(struct kmem_cache *s) { return (s->flags & SLAB_RECLAIM_ACCOUNT) ? NR_SLAB_RECLAIMABLE_B : NR_SLAB_UNRECLAIMABLE_B; } #ifdef CONFIG_SLUB_DEBUG #ifdef CONFIG_SLUB_DEBUG_ON DECLARE_STATIC_KEY_TRUE(slub_debug_enabled); #else DECLARE_STATIC_KEY_FALSE(slub_debug_enabled); #endif extern void print_tracking(struct kmem_cache *s, void *object); long validate_slab_cache(struct kmem_cache *s); #else static inline void print_tracking(struct kmem_cache *s, void *object) { } #endif /* * Returns true if any of the specified slub_debug flags is enabled for the * cache. Use only for flags parsed by setup_slub_debug() as it also enables * the static key. */ static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags) { #ifdef CONFIG_SLUB_DEBUG VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS)); if (static_branch_unlikely(&slub_debug_enabled)) return s->flags & flags; #endif return false; } #ifdef CONFIG_MEMCG_KMEM int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, gfp_t gfp, bool new_page); void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, enum node_stat_item idx, int nr); static inline void memcg_free_page_obj_cgroups(struct page *page) { kfree(page_objcgs(page)); page->memcg_data = 0; } static inline size_t obj_full_size(struct kmem_cache *s) { /* * For each accounted object there is an extra space which is used * to store obj_cgroup membership. Charge it too. */ return s->size + sizeof(struct obj_cgroup *); } /* * Returns false if the allocation should fail. */ static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, struct obj_cgroup **objcgp, size_t objects, gfp_t flags) { struct obj_cgroup *objcg; if (!memcg_kmem_enabled()) return true; if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)) return true; objcg = get_obj_cgroup_from_current(); if (!objcg) return true; if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) { obj_cgroup_put(objcg); return false; } *objcgp = objcg; return true; } static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg, gfp_t flags, size_t size, void **p) { struct page *page; unsigned long off; size_t i; if (!memcg_kmem_enabled() || !objcg) return; for (i = 0; i < size; i++) { if (likely(p[i])) { page = virt_to_head_page(p[i]); if (!page_objcgs(page) && memcg_alloc_page_obj_cgroups(page, s, flags, false)) { obj_cgroup_uncharge(objcg, obj_full_size(s)); continue; } off = obj_to_index(s, page, p[i]); obj_cgroup_get(objcg); page_objcgs(page)[off] = objcg; mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s), obj_full_size(s)); } else { obj_cgroup_uncharge(objcg, obj_full_size(s)); } } obj_cgroup_put(objcg); } static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, void **p, int objects) { struct kmem_cache *s; struct obj_cgroup **objcgs; struct obj_cgroup *objcg; struct page *page; unsigned int off; int i; if (!memcg_kmem_enabled()) return; for (i = 0; i < objects; i++) { if (unlikely(!p[i])) continue; page = virt_to_head_page(p[i]); objcgs = page_objcgs(page); if (!objcgs) continue; if (!s_orig) s = page->slab_cache; else s = s_orig; off = obj_to_index(s, page, p[i]); objcg = objcgs[off]; if (!objcg) continue; objcgs[off] = NULL; obj_cgroup_uncharge(objcg, obj_full_size(s)); mod_objcg_state(objcg, page_pgdat(page), cache_vmstat_idx(s), -obj_full_size(s)); obj_cgroup_put(objcg); } } #else /* CONFIG_MEMCG_KMEM */ static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) { return NULL; } static inline int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s, gfp_t gfp, bool new_page) { return 0; } static inline void memcg_free_page_obj_cgroups(struct page *page) { } static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, struct obj_cgroup **objcgp, size_t objects, gfp_t flags) { return true; } static inline void memcg_slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg, gfp_t flags, size_t size, void **p) { } static inline void memcg_slab_free_hook(struct kmem_cache *s, void **p, int objects) { } #endif /* CONFIG_MEMCG_KMEM */ static inline struct kmem_cache *virt_to_cache(const void *obj) { struct page *page; page = virt_to_head_page(obj); if (WARN_ONCE(!PageSlab(page), "%s: Object is not a Slab page!\n", __func__)) return NULL; return page->slab_cache; } static __always_inline void account_slab_page(struct page *page, int order, struct kmem_cache *s, gfp_t gfp) { if (memcg_kmem_enabled() && (s->flags & SLAB_ACCOUNT)) memcg_alloc_page_obj_cgroups(page, s, gfp, true); mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), PAGE_SIZE << order); } static __always_inline void unaccount_slab_page(struct page *page, int order, struct kmem_cache *s) { if (memcg_kmem_enabled()) memcg_free_page_obj_cgroups(page); mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), -(PAGE_SIZE << order)); } static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) { struct kmem_cache *cachep; if (!IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && !kmem_cache_debug_flags(s, SLAB_CONSISTENCY_CHECKS)) return s; cachep = virt_to_cache(x); if (WARN(cachep && cachep != s, "%s: Wrong slab cache. %s but object is from %s\n", __func__, s->name, cachep->name)) print_tracking(cachep, x); return cachep; } static inline size_t slab_ksize(const struct kmem_cache *s) { #ifndef CONFIG_SLUB return s->object_size; #else /* CONFIG_SLUB */ # ifdef CONFIG_SLUB_DEBUG /* * Debugging requires use of the padding between object * and whatever may come after it. */ if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) return s->object_size; # endif if (s->flags & SLAB_KASAN) return s->object_size; /* * If we have the need to store the freelist pointer * back there or track user information then we can * only use the space before that information. */ if (s->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_STORE_USER)) return s->inuse; /* * Else we can use all the padding etc for the allocation */ return s->size; #endif } static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s, struct obj_cgroup **objcgp, size_t size, gfp_t flags) { flags &= gfp_allowed_mask; might_alloc(flags); if (should_failslab(s, flags)) return NULL; if (!memcg_slab_pre_alloc_hook(s, objcgp, size, flags)) return NULL; return s; } static inline void slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg, gfp_t flags, size_t size, void **p, bool init) { size_t i; flags &= gfp_allowed_mask; /* * As memory initialization might be integrated into KASAN, * kasan_slab_alloc and initialization memset must be * kept together to avoid discrepancies in behavior. * * As p[i] might get tagged, memset and kmemleak hook come after KASAN. */ for (i = 0; i < size; i++) { p[i] = kasan_slab_alloc(s, p[i], flags, init); if (p[i] && init && !kasan_has_integrated_init()) memset(p[i], 0, s->object_size); kmemleak_alloc_recursive(p[i], s->object_size, 1, s->flags, flags); } memcg_slab_post_alloc_hook(s, objcg, flags, size, p); } #ifndef CONFIG_SLOB /* * The slab lists for all objects. */ struct kmem_cache_node { spinlock_t list_lock; #ifdef CONFIG_SLAB struct list_head slabs_partial; /* partial list first, better asm code */ struct list_head slabs_full; struct list_head slabs_free; unsigned long total_slabs; /* length of all slab lists */ unsigned long free_slabs; /* length of free slab list only */ unsigned long free_objects; unsigned int free_limit; unsigned int colour_next; /* Per-node cache coloring */ struct array_cache *shared; /* shared per node */ struct alien_cache **alien; /* on other nodes */ unsigned long next_reap; /* updated without locking */ int free_touched; /* updated without locking */ #endif #ifdef CONFIG_SLUB unsigned long nr_partial; struct list_head partial; #ifdef CONFIG_SLUB_DEBUG atomic_long_t nr_slabs; atomic_long_t total_objects; struct list_head full; #endif #endif }; static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) { return s->node[node]; } /* * Iterator over all nodes. The body will be executed for each node that has * a kmem_cache_node structure allocated (which is true for all online nodes) */ #define for_each_kmem_cache_node(__s, __node, __n) \ for (__node = 0; __node < nr_node_ids; __node++) \ if ((__n = get_node(__s, __node))) #endif void *slab_start(struct seq_file *m, loff_t *pos); void *slab_next(struct seq_file *m, void *p, loff_t *pos); void slab_stop(struct seq_file *m, void *p); int memcg_slab_show(struct seq_file *m, void *p); #if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) void dump_unreclaimable_slab(void); #else static inline void dump_unreclaimable_slab(void) { } #endif void ___cache_free(struct kmem_cache *cache, void *x, unsigned long addr); #ifdef CONFIG_SLAB_FREELIST_RANDOM int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, gfp_t gfp); void cache_random_seq_destroy(struct kmem_cache *cachep); #else static inline int cache_random_seq_create(struct kmem_cache *cachep, unsigned int count, gfp_t gfp) { return 0; } static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } #endif /* CONFIG_SLAB_FREELIST_RANDOM */ static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) { if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, &init_on_alloc)) { if (c->ctor) return false; if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) return flags & __GFP_ZERO; return true; } return flags & __GFP_ZERO; } static inline bool slab_want_init_on_free(struct kmem_cache *c) { if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, &init_on_free)) return !(c->ctor || (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); return false; } #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG) void debugfs_slab_release(struct kmem_cache *); #else static inline void debugfs_slab_release(struct kmem_cache *s) { } #endif #ifdef CONFIG_PRINTK #define KS_ADDRS_COUNT 16 struct kmem_obj_info { void *kp_ptr; struct page *kp_page; void *kp_objp; unsigned long kp_data_offset; struct kmem_cache *kp_slab_cache; void *kp_ret; void *kp_stack[KS_ADDRS_COUNT]; void *kp_free_stack[KS_ADDRS_COUNT]; }; void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page); #endif #endif /* MM_SLAB_H */