/* 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);
static inline bool __slub_debug_enabled(void)
{
        return static_branch_unlikely(&slub_debug_enabled);
}
#else
static inline void print_tracking(struct kmem_cache *s, void *object)
{
}
static inline bool __slub_debug_enabled(void)
{
        return false;
}
#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)
{
        if (IS_ENABLED(CONFIG_SLUB_DEBUG))
                VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
        if (__slub_debug_enabled())
                return s->flags & flags;
        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_check(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 */