/* 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 */ }; #else /* !CONFIG_SLOB */ struct memcg_cache_array { struct rcu_head rcu; struct kmem_cache *entries[0]; }; /* * This is the main placeholder for memcg-related information in kmem caches. * Both the root cache and the child caches will have it. For the root cache, * this will hold a dynamically allocated array large enough to hold * information about the currently limited memcgs in the system. To allow the * array to be accessed without taking any locks, on relocation we free the old * version only after a grace period. * * Root and child caches hold different metadata. * * @root_cache: Common to root and child caches. NULL for root, pointer to * the root cache for children. * * The following fields are specific to root caches. * * @memcg_caches: kmemcg ID indexed table of child caches. This table is * used to index child cachces during allocation and cleared * early during shutdown. * * @root_caches_node: List node for slab_root_caches list. * * @children: List of all child caches. While the child caches are also * reachable through @memcg_caches, a child cache remains on * this list until it is actually destroyed. * * The following fields are specific to child caches. * * @memcg: Pointer to the memcg this cache belongs to. * * @children_node: List node for @root_cache->children list. * * @kmem_caches_node: List node for @memcg->kmem_caches list. */ struct memcg_cache_params { struct kmem_cache *root_cache; union { struct { struct memcg_cache_array __rcu *memcg_caches; struct list_head __root_caches_node; struct list_head children; bool dying; }; struct { struct mem_cgroup *memcg; struct list_head children_node; struct list_head kmem_caches_node; struct percpu_ref refcnt; void (*work_fn)(struct kmem_cache *); union { struct rcu_head rcu_head; struct work_struct work; }; }; }; }; #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 /* 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, void (*ctor)(void *)); #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, void (*ctor)(void *)) { 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 __kmemcg_cache_deactivate(struct kmem_cache *s); void __kmemcg_cache_deactivate_after_rcu(struct kmem_cache *s); void slab_kmem_cache_release(struct kmem_cache *); void kmem_cache_shrink_all(struct kmem_cache *s); 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 int cache_vmstat_idx(struct kmem_cache *s) { return (s->flags & SLAB_RECLAIM_ACCOUNT) ? NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE; } #ifdef CONFIG_MEMCG_KMEM /* List of all root caches. */ extern struct list_head slab_root_caches; #define root_caches_node memcg_params.__root_caches_node /* * Iterate over all memcg caches of the given root cache. The caller must hold * slab_mutex. */ #define for_each_memcg_cache(iter, root) \ list_for_each_entry(iter, &(root)->memcg_params.children, \ memcg_params.children_node) static inline bool is_root_cache(struct kmem_cache *s) { return !s->memcg_params.root_cache; } static inline bool slab_equal_or_root(struct kmem_cache *s, struct kmem_cache *p) { return p == s || p == s->memcg_params.root_cache; } /* * We use suffixes to the name in memcg because we can't have caches * created in the system with the same name. But when we print them * locally, better refer to them with the base name */ static inline const char *cache_name(struct kmem_cache *s) { if (!is_root_cache(s)) s = s->memcg_params.root_cache; return s->name; } static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) { if (is_root_cache(s)) return s; return s->memcg_params.root_cache; } /* * Expects a pointer to a slab page. Please note, that PageSlab() check * isn't sufficient, as it returns true also for tail compound slab pages, * which do not have slab_cache pointer set. * So this function assumes that the page can pass PageSlab() && !PageTail() * check. * * The kmem_cache can be reparented asynchronously. The caller must ensure * the memcg lifetime, e.g. by taking rcu_read_lock() or cgroup_mutex. */ static inline struct mem_cgroup *memcg_from_slab_page(struct page *page) { struct kmem_cache *s; s = READ_ONCE(page->slab_cache); if (s && !is_root_cache(s)) return READ_ONCE(s->memcg_params.memcg); return NULL; } /* * Charge the slab page belonging to the non-root kmem_cache. * Can be called for non-root kmem_caches only. */ static __always_inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order, struct kmem_cache *s) { int nr_pages = 1 << order; struct mem_cgroup *memcg; struct lruvec *lruvec; int ret; rcu_read_lock(); memcg = READ_ONCE(s->memcg_params.memcg); while (memcg && !css_tryget_online(&memcg->css)) memcg = parent_mem_cgroup(memcg); rcu_read_unlock(); if (unlikely(!memcg || mem_cgroup_is_root(memcg))) { mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), nr_pages); percpu_ref_get_many(&s->memcg_params.refcnt, nr_pages); return 0; } ret = memcg_kmem_charge(memcg, gfp, nr_pages); if (ret) goto out; lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page)); mod_lruvec_state(lruvec, cache_vmstat_idx(s), nr_pages); /* transer try_charge() page references to kmem_cache */ percpu_ref_get_many(&s->memcg_params.refcnt, nr_pages); css_put_many(&memcg->css, nr_pages); out: css_put(&memcg->css); return ret; } /* * Uncharge a slab page belonging to a non-root kmem_cache. * Can be called for non-root kmem_caches only. */ static __always_inline void memcg_uncharge_slab(struct page *page, int order, struct kmem_cache *s) { int nr_pages = 1 << order; struct mem_cgroup *memcg; struct lruvec *lruvec; rcu_read_lock(); memcg = READ_ONCE(s->memcg_params.memcg); if (likely(!mem_cgroup_is_root(memcg))) { lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page)); mod_lruvec_state(lruvec, cache_vmstat_idx(s), -nr_pages); memcg_kmem_uncharge(memcg, nr_pages); } else { mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), -nr_pages); } rcu_read_unlock(); percpu_ref_put_many(&s->memcg_params.refcnt, nr_pages); } extern void slab_init_memcg_params(struct kmem_cache *); extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg); #else /* CONFIG_MEMCG_KMEM */ /* If !memcg, all caches are root. */ #define slab_root_caches slab_caches #define root_caches_node list #define for_each_memcg_cache(iter, root) \ for ((void)(iter), (void)(root); 0; ) static inline bool is_root_cache(struct kmem_cache *s) { return true; } static inline bool slab_equal_or_root(struct kmem_cache *s, struct kmem_cache *p) { return s == p; } static inline const char *cache_name(struct kmem_cache *s) { return s->name; } static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s) { return s; } static inline struct mem_cgroup *memcg_from_slab_page(struct page *page) { return NULL; } static inline int memcg_charge_slab(struct page *page, gfp_t gfp, int order, struct kmem_cache *s) { return 0; } static inline void memcg_uncharge_slab(struct page *page, int order, struct kmem_cache *s) { } static inline void slab_init_memcg_params(struct kmem_cache *s) { } static inline void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg) { } #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 int charge_slab_page(struct page *page, gfp_t gfp, int order, struct kmem_cache *s) { if (is_root_cache(s)) { mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), 1 << order); return 0; } return memcg_charge_slab(page, gfp, order, s); } static __always_inline void uncharge_slab_page(struct page *page, int order, struct kmem_cache *s) { if (is_root_cache(s)) { mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s), -(1 << order)); return; } memcg_uncharge_slab(page, order, s); } static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x) { struct kmem_cache *cachep; /* * When kmemcg is not being used, both assignments should return the * same value. but we don't want to pay the assignment price in that * case. If it is not compiled in, the compiler should be smart enough * to not do even the assignment. In that case, slab_equal_or_root * will also be a constant. */ if (!memcg_kmem_enabled() && !IS_ENABLED(CONFIG_SLAB_FREELIST_HARDENED) && !unlikely(s->flags & SLAB_CONSISTENCY_CHECKS)) return s; cachep = virt_to_cache(x); WARN_ONCE(cachep && !slab_equal_or_root(cachep, s), "%s: Wrong slab cache. %s but object is from %s\n", __func__, s->name, cachep->name); 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, gfp_t flags) { flags &= gfp_allowed_mask; fs_reclaim_acquire(flags); fs_reclaim_release(flags); might_sleep_if(gfpflags_allow_blocking(flags)); if (should_failslab(s, flags)) return NULL; if (memcg_kmem_enabled() && ((flags & __GFP_ACCOUNT) || (s->flags & SLAB_ACCOUNT))) return memcg_kmem_get_cache(s); return s; } static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, size_t size, void **p) { size_t i; flags &= gfp_allowed_mask; for (i = 0; i < size; i++) { p[i] = kasan_slab_alloc(s, p[i], flags); /* As p[i] might get tagged, call kmemleak hook after KASAN. */ kmemleak_alloc_recursive(p[i], s->object_size, 1, s->flags, flags); } if (memcg_kmem_enabled()) memcg_kmem_put_cache(s); } #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); void *memcg_slab_start(struct seq_file *m, loff_t *pos); void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos); void memcg_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_unlikely(&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_unlikely(&init_on_free)) return !(c->ctor || (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); return false; } #endif /* MM_SLAB_H */