diff options
Diffstat (limited to 'mm/slab.h')
| -rw-r--r-- | mm/slab.h | 551 |
1 files changed, 169 insertions, 382 deletions
@@ -1,10 +1,20 @@ /* SPDX-License-Identifier: GPL-2.0 */ #ifndef MM_SLAB_H #define MM_SLAB_H + +#include <linux/reciprocal_div.h> +#include <linux/list_lru.h> +#include <linux/local_lock.h> +#include <linux/random.h> +#include <linux/kobject.h> +#include <linux/sched/mm.h> +#include <linux/memcontrol.h> +#include <linux/kfence.h> +#include <linux/kasan.h> + /* * Internal slab definitions */ -void __init kmem_cache_init(void); #ifdef CONFIG_64BIT # ifdef system_has_cmpxchg128 @@ -42,21 +52,6 @@ typedef union { struct slab { unsigned long __page_flags; -#if defined(CONFIG_SLAB) - - struct kmem_cache *slab_cache; - union { - struct { - struct list_head slab_list; - void *freelist; /* array of free object indexes */ - void *s_mem; /* first object */ - }; - struct rcu_head rcu_head; - }; - unsigned int active; - -#elif defined(CONFIG_SLUB) - struct kmem_cache *slab_cache; union { struct { @@ -91,10 +86,6 @@ struct slab { }; unsigned int __unused; -#else -#error "Unexpected slab allocator configured" -#endif - atomic_t __page_refcount; #ifdef CONFIG_MEMCG unsigned long memcg_data; @@ -111,7 +102,7 @@ SLAB_MATCH(memcg_data, memcg_data); #endif #undef SLAB_MATCH static_assert(sizeof(struct slab) <= sizeof(struct page)); -#if defined(system_has_freelist_aba) && defined(CONFIG_SLUB) +#if defined(system_has_freelist_aba) static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t))); #endif @@ -228,21 +219,138 @@ static inline size_t slab_size(const struct slab *slab) return PAGE_SIZE << slab_order(slab); } -#ifdef CONFIG_SLAB -#include <linux/slab_def.h> +#ifdef CONFIG_SLUB_CPU_PARTIAL +#define slub_percpu_partial(c) ((c)->partial) + +#define slub_set_percpu_partial(c, p) \ +({ \ + slub_percpu_partial(c) = (p)->next; \ +}) + +#define slub_percpu_partial_read_once(c) READ_ONCE(slub_percpu_partial(c)) +#else +#define slub_percpu_partial(c) NULL + +#define slub_set_percpu_partial(c, p) + +#define slub_percpu_partial_read_once(c) NULL +#endif // CONFIG_SLUB_CPU_PARTIAL + +/* + * Word size structure that can be atomically updated or read and that + * contains both the order and the number of objects that a slab of the + * given order would contain. + */ +struct kmem_cache_order_objects { + unsigned int x; +}; + +/* + * Slab cache management. + */ +struct kmem_cache { +#ifndef CONFIG_SLUB_TINY + struct kmem_cache_cpu __percpu *cpu_slab; +#endif + /* Used for retrieving partial slabs, etc. */ + slab_flags_t flags; + unsigned long min_partial; + unsigned int size; /* Object size including metadata */ + unsigned int object_size; /* Object size without metadata */ + struct reciprocal_value reciprocal_size; + unsigned int offset; /* Free pointer offset */ +#ifdef CONFIG_SLUB_CPU_PARTIAL + /* Number of per cpu partial objects to keep around */ + unsigned int cpu_partial; + /* Number of per cpu partial slabs to keep around */ + unsigned int cpu_partial_slabs; +#endif + struct kmem_cache_order_objects oo; + + /* Allocation and freeing of slabs */ + struct kmem_cache_order_objects min; + gfp_t allocflags; /* gfp flags to use on each alloc */ + int refcount; /* Refcount for slab cache destroy */ + void (*ctor)(void *object); /* Object constructor */ + unsigned int inuse; /* Offset to metadata */ + unsigned int align; /* Alignment */ + unsigned int red_left_pad; /* Left redzone padding size */ + const char *name; /* Name (only for display!) */ + struct list_head list; /* List of slab caches */ +#ifdef CONFIG_SYSFS + struct kobject kobj; /* For sysfs */ +#endif +#ifdef CONFIG_SLAB_FREELIST_HARDENED + unsigned long random; #endif -#ifdef CONFIG_SLUB -#include <linux/slub_def.h> +#ifdef CONFIG_NUMA + /* + * Defragmentation by allocating from a remote node. + */ + unsigned int remote_node_defrag_ratio; #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> -#include <linux/list_lru.h> +#ifdef CONFIG_SLAB_FREELIST_RANDOM + unsigned int *random_seq; +#endif + +#ifdef CONFIG_KASAN_GENERIC + struct kasan_cache kasan_info; +#endif + +#ifdef CONFIG_HARDENED_USERCOPY + unsigned int useroffset; /* Usercopy region offset */ + unsigned int usersize; /* Usercopy region size */ +#endif + + struct kmem_cache_node *node[MAX_NUMNODES]; +}; + +#if defined(CONFIG_SYSFS) && !defined(CONFIG_SLUB_TINY) +#define SLAB_SUPPORTS_SYSFS +void sysfs_slab_unlink(struct kmem_cache *s); +void sysfs_slab_release(struct kmem_cache *s); +#else +static inline void sysfs_slab_unlink(struct kmem_cache *s) { } +static inline void sysfs_slab_release(struct kmem_cache *s) { } +#endif + +void *fixup_red_left(struct kmem_cache *s, void *p); + +static inline void *nearest_obj(struct kmem_cache *cache, + const struct slab *slab, void *x) +{ + void *object = x - (x - slab_address(slab)) % cache->size; + void *last_object = slab_address(slab) + + (slab->objects - 1) * cache->size; + void *result = (unlikely(object > last_object)) ? last_object : object; + + result = fixup_red_left(cache, result); + return result; +} + +/* Determine object index from a given position */ +static inline unsigned int __obj_to_index(const struct kmem_cache *cache, + void *addr, void *obj) +{ + return reciprocal_divide(kasan_reset_tag(obj) - addr, + cache->reciprocal_size); +} + +static inline unsigned int obj_to_index(const struct kmem_cache *cache, + const struct slab *slab, void *obj) +{ + if (is_kfence_address(obj)) + return 0; + return __obj_to_index(cache, slab_address(slab), obj); +} + +static inline int objs_per_slab(const struct kmem_cache *cache, + const struct slab *slab) +{ + return slab->objects; +} /* * State of the slab allocator. @@ -281,19 +389,39 @@ extern const struct kmalloc_info_struct { 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 size, gfp_t flags, unsigned long caller); +extern u8 kmalloc_size_index[24]; + +static inline unsigned int size_index_elem(unsigned int bytes) +{ + return (bytes - 1) / 8; +} + +/* + * Find the kmem_cache structure that serves a given size of + * allocation + * + * This assumes size is larger than zero and not larger than + * KMALLOC_MAX_CACHE_SIZE and the caller must check that. + */ +static inline struct kmem_cache * +kmalloc_slab(size_t size, gfp_t flags, unsigned long caller) +{ + unsigned int index; + + if (size <= 192) + index = kmalloc_size_index[size_index_elem(size)]; + else + index = fls(size - 1); -void *__kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, - int node, size_t orig_size, - unsigned long caller); -void __kmem_cache_free(struct kmem_cache *s, void *x, unsigned long caller); + return kmalloc_caches[kmalloc_type(flags, caller)][index]; +} 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); +void __init kmem_cache_init(void); void __init new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags); extern void create_boot_cache(struct kmem_cache *, const char *name, @@ -320,26 +448,16 @@ static inline bool is_kmalloc_cache(struct kmem_cache *s) 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) +#ifdef 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 | SLAB_NO_MERGE) -#elif defined(CONFIG_SLUB) #define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \ SLAB_TEMPORARY | SLAB_ACCOUNT | \ SLAB_NO_USER_FLAGS | SLAB_KMALLOC | SLAB_NO_MERGE) -#else -#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE) -#endif /* Common flags available with current configuration */ #define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS) @@ -387,12 +505,6 @@ 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); -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); @@ -452,238 +564,32 @@ int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, gfp_t gfp, bool new_slab); void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat, enum node_stat_item idx, int nr); - -static inline void memcg_free_slab_cgroups(struct slab *slab) -{ - kfree(slab_objcgs(slab)); - slab->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 list_lru *lru, - struct obj_cgroup **objcgp, - size_t objects, gfp_t flags) -{ - struct obj_cgroup *objcg; - - if (!memcg_kmem_online()) - return true; - - if (!(flags & __GFP_ACCOUNT) && !(s->flags & SLAB_ACCOUNT)) - return true; - - /* - * The obtained objcg pointer is safe to use within the current scope, - * defined by current task or set_active_memcg() pair. - * obj_cgroup_get() is used to get a permanent reference. - */ - objcg = current_obj_cgroup(); - if (!objcg) - return true; - - if (lru) { - int ret; - struct mem_cgroup *memcg; - - memcg = get_mem_cgroup_from_objcg(objcg); - ret = memcg_list_lru_alloc(memcg, lru, flags); - css_put(&memcg->css); - - if (ret) - return false; - } - - if (obj_cgroup_charge(objcg, flags, objects * obj_full_size(s))) - 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 slab *slab; - unsigned long off; - size_t i; - - if (!memcg_kmem_online() || !objcg) - return; - - for (i = 0; i < size; i++) { - if (likely(p[i])) { - slab = virt_to_slab(p[i]); - - if (!slab_objcgs(slab) && - memcg_alloc_slab_cgroups(slab, s, flags, - false)) { - obj_cgroup_uncharge(objcg, obj_full_size(s)); - continue; - } - - off = obj_to_index(s, slab, p[i]); - obj_cgroup_get(objcg); - slab_objcgs(slab)[off] = objcg; - mod_objcg_state(objcg, slab_pgdat(slab), - cache_vmstat_idx(s), obj_full_size(s)); - } else { - obj_cgroup_uncharge(objcg, obj_full_size(s)); - } - } -} - -static inline void memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab, - void **p, int objects) -{ - struct obj_cgroup **objcgs; - int i; - - if (!memcg_kmem_online()) - return; - - objcgs = slab_objcgs(slab); - if (!objcgs) - return; - - for (i = 0; i < objects; i++) { - struct obj_cgroup *objcg; - unsigned int off; - - off = obj_to_index(s, slab, p[i]); - objcg = objcgs[off]; - if (!objcg) - continue; - - objcgs[off] = NULL; - obj_cgroup_uncharge(objcg, obj_full_size(s)); - mod_objcg_state(objcg, slab_pgdat(slab), cache_vmstat_idx(s), - -obj_full_size(s)); - obj_cgroup_put(objcg); - } -} - #else /* CONFIG_MEMCG_KMEM */ static inline struct obj_cgroup **slab_objcgs(struct slab *slab) { return NULL; } -static inline struct mem_cgroup *memcg_from_slab_obj(void *ptr) -{ - return NULL; -} - static inline int memcg_alloc_slab_cgroups(struct slab *slab, struct kmem_cache *s, gfp_t gfp, bool new_slab) { return 0; } - -static inline void memcg_free_slab_cgroups(struct slab *slab) -{ -} - -static inline bool memcg_slab_pre_alloc_hook(struct kmem_cache *s, - struct list_lru *lru, - 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, struct slab *slab, - void **p, int objects) -{ -} #endif /* CONFIG_MEMCG_KMEM */ -static inline struct kmem_cache *virt_to_cache(const void *obj) -{ - struct slab *slab; - - slab = virt_to_slab(obj); - if (WARN_ONCE(!slab, "%s: Object is not a Slab page!\n", - __func__)) - return NULL; - return slab->slab_cache; -} - -static __always_inline void account_slab(struct slab *slab, int order, - struct kmem_cache *s, gfp_t gfp) -{ - if (memcg_kmem_online() && (s->flags & SLAB_ACCOUNT)) - memcg_alloc_slab_cgroups(slab, s, gfp, true); - - mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), - PAGE_SIZE << order); -} - -static __always_inline void unaccount_slab(struct slab *slab, int order, - struct kmem_cache *s) -{ - if (memcg_kmem_online()) - memcg_free_slab_cgroups(slab); - - mod_node_page_state(slab_pgdat(slab), 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; -} - -void free_large_kmalloc(struct folio *folio, void *object); - size_t __ksize(const void *objp); 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 +#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 +#endif if (s->flags & SLAB_KASAN) return s->object_size; /* @@ -697,128 +603,9 @@ static inline size_t slab_ksize(const struct kmem_cache *s) * 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 list_lru *lru, - 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, lru, 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, - unsigned int orig_size) -{ - unsigned int zero_size = s->object_size; - bool kasan_init = init; - size_t i; - - flags &= gfp_allowed_mask; - - /* - * For kmalloc object, the allocated memory size(object_size) is likely - * larger than the requested size(orig_size). If redzone check is - * enabled for the extra space, don't zero it, as it will be redzoned - * soon. The redzone operation for this extra space could be seen as a - * replacement of current poisoning under certain debug option, and - * won't break other sanity checks. - */ - if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) && - (s->flags & SLAB_KMALLOC)) - zero_size = orig_size; - - /* - * When slub_debug is enabled, avoid memory initialization integrated - * into KASAN and instead zero out the memory via the memset below with - * the proper size. Otherwise, KASAN might overwrite SLUB redzones and - * cause false-positive reports. This does not lead to a performance - * penalty on production builds, as slub_debug is not intended to be - * enabled there. - */ - if (__slub_debug_enabled()) - kasan_init = false; - - /* - * 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, kasan_init); - if (p[i] && init && (!kasan_init || !kasan_has_integrated_init())) - memset(p[i], 0, zero_size); - kmemleak_alloc_recursive(p[i], s->object_size, 1, - s->flags, flags); - kmsan_slab_alloc(s, p[i], flags); - } - - memcg_slab_post_alloc_hook(s, objcg, flags, size, p); } -/* - * The slab lists for all objects. - */ -struct kmem_cache_node { -#ifdef CONFIG_SLAB - raw_spinlock_t list_lock; - 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 - spinlock_t list_lock; - 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))) - - -#if defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG) void dump_unreclaimable_slab(void); #else static inline void dump_unreclaimable_slab(void) |