summaryrefslogtreecommitdiffstats
path: root/mm/slab.h
diff options
context:
space:
mode:
Diffstat (limited to 'mm/slab.h')
-rw-r--r--mm/slab.h638
1 files changed, 638 insertions, 0 deletions
diff --git a/mm/slab.h b/mm/slab.h
new file mode 100644
index 000000000..6952e10cf
--- /dev/null
+++ b/mm/slab.h
@@ -0,0 +1,638 @@
+/* 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 (SLAB_NOLEAKTRACE)
+#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 int 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);
+#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
+static inline struct obj_cgroup **page_obj_cgroups(struct page *page)
+{
+ /*
+ * page->mem_cgroup and page->obj_cgroups are sharing the same
+ * space. To distinguish between them in case we don't know for sure
+ * that the page is a slab page (e.g. page_cgroup_ino()), let's
+ * always set the lowest bit of obj_cgroups.
+ */
+ return (struct obj_cgroup **)
+ ((unsigned long)page->obj_cgroups & ~0x1UL);
+}
+
+static inline bool page_has_obj_cgroups(struct page *page)
+{
+ return ((unsigned long)page->obj_cgroups & 0x1UL);
+}
+
+int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
+ gfp_t gfp);
+
+static inline void memcg_free_page_obj_cgroups(struct page *page)
+{
+ kfree(page_obj_cgroups(page));
+ page->obj_cgroups = NULL;
+}
+
+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 mod_objcg_state(struct obj_cgroup *objcg,
+ struct pglist_data *pgdat,
+ int idx, int nr)
+{
+ struct mem_cgroup *memcg;
+ struct lruvec *lruvec;
+
+ rcu_read_lock();
+ memcg = obj_cgroup_memcg(objcg);
+ lruvec = mem_cgroup_lruvec(memcg, pgdat);
+ mod_memcg_lruvec_state(lruvec, idx, nr);
+ rcu_read_unlock();
+}
+
+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_has_obj_cgroups(page) &&
+ memcg_alloc_page_obj_cgroups(page, s, flags)) {
+ obj_cgroup_uncharge(objcg, obj_full_size(s));
+ continue;
+ }
+
+ off = obj_to_index(s, page, p[i]);
+ obj_cgroup_get(objcg);
+ page_obj_cgroups(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 *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]);
+ if (!page_has_obj_cgroups(page))
+ continue;
+
+ if (!s_orig)
+ s = page->slab_cache;
+ else
+ s = s_orig;
+
+ off = obj_to_index(s, page, p[i]);
+ objcg = page_obj_cgroups(page)[off];
+ if (!objcg)
+ continue;
+
+ page_obj_cgroups(page)[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 bool page_has_obj_cgroups(struct page *page)
+{
+ return false;
+}
+
+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)
+{
+ 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)
+{
+ 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;
+
+ fs_reclaim_acquire(flags);
+ fs_reclaim_release(flags);
+
+ might_sleep_if(gfpflags_allow_blocking(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)
+{
+ 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);
+ }
+
+ 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_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 */