[thirdparty/linux.git] /

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
 */
#include <linux/bpf.h>
#include <linux/bpf-cgroup.h>
#include <linux/bpf_trace.h>
#include <linux/bpf_lirc.h>
#include <linux/bpf_verifier.h>
#include <linux/bsearch.h>
#include <linux/btf.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/vmalloc.h>
#include <linux/mmzone.h>
#include <linux/anon_inodes.h>
#include <linux/fdtable.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/license.h>
#include <linux/filter.h>
#include <linux/kernel.h>
#include <linux/idr.h>
#include <linux/cred.h>
#include <linux/timekeeping.h>
#include <linux/ctype.h>
#include <linux/nospec.h>
#include <linux/audit.h>
#include <uapi/linux/btf.h>
#include <linux/pgtable.h>
#include <linux/bpf_lsm.h>
#include <linux/poll.h>
#include <linux/sort.h>
#include <linux/bpf-netns.h>
#include <linux/rcupdate_trace.h>
#include <linux/memcontrol.h>
#include <linux/trace_events.h>

#include <net/netfilter/nf_bpf_link.h>
#include <net/netkit.h>
#include <net/tcx.h>

#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
                          (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
                          (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
#define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
#define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
                        IS_FD_HASH(map))

#define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)

DEFINE_PER_CPU(int, bpf_prog_active);
static DEFINE_IDR(prog_idr);
static DEFINE_SPINLOCK(prog_idr_lock);
static DEFINE_IDR(map_idr);
static DEFINE_SPINLOCK(map_idr_lock);
static DEFINE_IDR(link_idr);
static DEFINE_SPINLOCK(link_idr_lock);

int sysctl_unprivileged_bpf_disabled __read_mostly =
        IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;

static const struct bpf_map_ops * const bpf_map_types[] = {
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
#define BPF_MAP_TYPE(_id, _ops) \
        [_id] = &_ops,
#define BPF_LINK_TYPE(_id, _name)
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
#undef BPF_LINK_TYPE
};

/*
 * If we're handed a bigger struct than we know of, ensure all the unknown bits
 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
 * we don't know about yet.
 *
 * There is a ToCToU between this function call and the following
 * copy_from_user() call. However, this is not a concern since this function is
 * meant to be a future-proofing of bits.
 */
int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
                             size_t expected_size,
                             size_t actual_size)
{
        int res;

        if (unlikely(actual_size > PAGE_SIZE))  /* silly large */
                return -E2BIG;

        if (actual_size <= expected_size)
                return 0;

        if (uaddr.is_kernel)
                res = memchr_inv(uaddr.kernel + expected_size, 0,
                                 actual_size - expected_size) == NULL;
        else
                res = check_zeroed_user(uaddr.user + expected_size,
                                        actual_size - expected_size);
        if (res < 0)
                return res;
        return res ? 0 : -E2BIG;
}

const struct bpf_map_ops bpf_map_offload_ops = {
        .map_meta_equal = bpf_map_meta_equal,
        .map_alloc = bpf_map_offload_map_alloc,
        .map_free = bpf_map_offload_map_free,
        .map_check_btf = map_check_no_btf,
        .map_mem_usage = bpf_map_offload_map_mem_usage,
};

static void bpf_map_write_active_inc(struct bpf_map *map)
{
        atomic64_inc(&map->writecnt);
}

static void bpf_map_write_active_dec(struct bpf_map *map)
{
        atomic64_dec(&map->writecnt);
}

bool bpf_map_write_active(const struct bpf_map *map)
{
        return atomic64_read(&map->writecnt) != 0;
}

static u32 bpf_map_value_size(const struct bpf_map *map)
{
        if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
            map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
            map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
            map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
                return round_up(map->value_size, 8) * num_possible_cpus();
        else if (IS_FD_MAP(map))
                return sizeof(u32);
        else
                return  map->value_size;
}

static void maybe_wait_bpf_programs(struct bpf_map *map)
{
        /* Wait for any running BPF programs to complete so that
         * userspace, when we return to it, knows that all programs
         * that could be running use the new map value.
         */
        if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
            map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
                synchronize_rcu();
}

static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
                                void *key, void *value, __u64 flags)
{
        int err;

        /* Need to create a kthread, thus must support schedule */
        if (bpf_map_is_offloaded(map)) {
                return bpf_map_offload_update_elem(map, key, value, flags);
        } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
                   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
                return map->ops->map_update_elem(map, key, value, flags);
        } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
                   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
                return sock_map_update_elem_sys(map, key, value, flags);
        } else if (IS_FD_PROG_ARRAY(map)) {
                return bpf_fd_array_map_update_elem(map, map_file, key, value,
                                                    flags);
        }

        bpf_disable_instrumentation();
        if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
            map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
                err = bpf_percpu_hash_update(map, key, value, flags);
        } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
                err = bpf_percpu_array_update(map, key, value, flags);
        } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
                err = bpf_percpu_cgroup_storage_update(map, key, value,
                                                       flags);
        } else if (IS_FD_ARRAY(map)) {
                rcu_read_lock();
                err = bpf_fd_array_map_update_elem(map, map_file, key, value,
                                                   flags);
                rcu_read_unlock();
        } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
                rcu_read_lock();
                err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
                                                  flags);
                rcu_read_unlock();
        } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
                /* rcu_read_lock() is not needed */
                err = bpf_fd_reuseport_array_update_elem(map, key, value,
                                                         flags);
        } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
                   map->map_type == BPF_MAP_TYPE_STACK ||
                   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
                err = map->ops->map_push_elem(map, value, flags);
        } else {
                rcu_read_lock();
                err = map->ops->map_update_elem(map, key, value, flags);
                rcu_read_unlock();
        }
        bpf_enable_instrumentation();
        maybe_wait_bpf_programs(map);

        return err;
}

static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
                              __u64 flags)
{
        void *ptr;
        int err;

        if (bpf_map_is_offloaded(map))
                return bpf_map_offload_lookup_elem(map, key, value);

        bpf_disable_instrumentation();
        if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
            map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
                err = bpf_percpu_hash_copy(map, key, value);
        } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
                err = bpf_percpu_array_copy(map, key, value);
        } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
                err = bpf_percpu_cgroup_storage_copy(map, key, value);
        } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
                err = bpf_stackmap_copy(map, key, value);
        } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
                err = bpf_fd_array_map_lookup_elem(map, key, value);
        } else if (IS_FD_HASH(map)) {
                err = bpf_fd_htab_map_lookup_elem(map, key, value);
        } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
                err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
        } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
                   map->map_type == BPF_MAP_TYPE_STACK ||
                   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
                err = map->ops->map_peek_elem(map, value);
        } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
                /* struct_ops map requires directly updating "value" */
                err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
        } else {
                rcu_read_lock();
                if (map->ops->map_lookup_elem_sys_only)
                        ptr = map->ops->map_lookup_elem_sys_only(map, key);
                else
                        ptr = map->ops->map_lookup_elem(map, key);
                if (IS_ERR(ptr)) {
                        err = PTR_ERR(ptr);
                } else if (!ptr) {
                        err = -ENOENT;
                } else {
                        err = 0;
                        if (flags & BPF_F_LOCK)
                                /* lock 'ptr' and copy everything but lock */
                                copy_map_value_locked(map, value, ptr, true);
                        else
                                copy_map_value(map, value, ptr);
                        /* mask lock and timer, since value wasn't zero inited */
                        check_and_init_map_value(map, value);
                }
                rcu_read_unlock();
        }

        bpf_enable_instrumentation();
        maybe_wait_bpf_programs(map);

        return err;
}

/* Please, do not use this function outside from the map creation path
 * (e.g. in map update path) without taking care of setting the active
 * memory cgroup (see at bpf_map_kmalloc_node() for example).
 */
static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
{
        /* We really just want to fail instead of triggering OOM killer
         * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
         * which is used for lower order allocation requests.
         *
         * It has been observed that higher order allocation requests done by
         * vmalloc with __GFP_NORETRY being set might fail due to not trying
         * to reclaim memory from the page cache, thus we set
         * __GFP_RETRY_MAYFAIL to avoid such situations.
         */

        gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
        unsigned int flags = 0;
        unsigned long align = 1;
        void *area;

        if (size >= SIZE_MAX)
                return NULL;

        /* kmalloc()'ed memory can't be mmap()'ed */
        if (mmapable) {
                BUG_ON(!PAGE_ALIGNED(size));
                align = SHMLBA;
                flags = VM_USERMAP;
        } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
                area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
                                    numa_node);
                if (area != NULL)
                        return area;
        }

        return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
                        gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
                        flags, numa_node, __builtin_return_address(0));
}

void *bpf_map_area_alloc(u64 size, int numa_node)
{
        return __bpf_map_area_alloc(size, numa_node, false);
}

void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
{
        return __bpf_map_area_alloc(size, numa_node, true);
}

void bpf_map_area_free(void *area)
{
        kvfree(area);
}

static u32 bpf_map_flags_retain_permanent(u32 flags)
{
        /* Some map creation flags are not tied to the map object but
         * rather to the map fd instead, so they have no meaning upon
         * map object inspection since multiple file descriptors with
         * different (access) properties can exist here. Thus, given
         * this has zero meaning for the map itself, lets clear these
         * from here.
         */
        return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
}

void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
{
        map->map_type = attr->map_type;
        map->key_size = attr->key_size;
        map->value_size = attr->value_size;
        map->max_entries = attr->max_entries;
        map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
        map->numa_node = bpf_map_attr_numa_node(attr);
        map->map_extra = attr->map_extra;
}

static int bpf_map_alloc_id(struct bpf_map *map)
{
        int id;

        idr_preload(GFP_KERNEL);
        spin_lock_bh(&map_idr_lock);
        id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
        if (id > 0)
                map->id = id;
        spin_unlock_bh(&map_idr_lock);
        idr_preload_end();

        if (WARN_ON_ONCE(!id))
                return -ENOSPC;

        return id > 0 ? 0 : id;
}

void bpf_map_free_id(struct bpf_map *map)
{
        unsigned long flags;

        /* Offloaded maps are removed from the IDR store when their device
         * disappears - even if someone holds an fd to them they are unusable,
         * the memory is gone, all ops will fail; they are simply waiting for
         * refcnt to drop to be freed.
         */
        if (!map->id)
                return;

        spin_lock_irqsave(&map_idr_lock, flags);

        idr_remove(&map_idr, map->id);
        map->id = 0;

        spin_unlock_irqrestore(&map_idr_lock, flags);
}

#ifdef CONFIG_MEMCG_KMEM
static void bpf_map_save_memcg(struct bpf_map *map)
{
        /* Currently if a map is created by a process belonging to the root
         * memory cgroup, get_obj_cgroup_from_current() will return NULL.
         * So we have to check map->objcg for being NULL each time it's
         * being used.
         */
        if (memcg_bpf_enabled())
                map->objcg = get_obj_cgroup_from_current();
}

static void bpf_map_release_memcg(struct bpf_map *map)
{
        if (map->objcg)
                obj_cgroup_put(map->objcg);
}

static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
{
        if (map->objcg)
                return get_mem_cgroup_from_objcg(map->objcg);

        return root_mem_cgroup;
}

void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
                           int node)
{
        struct mem_cgroup *memcg, *old_memcg;
        void *ptr;

        memcg = bpf_map_get_memcg(map);
        old_memcg = set_active_memcg(memcg);
        ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
        set_active_memcg(old_memcg);
        mem_cgroup_put(memcg);

        return ptr;
}

void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
{
        struct mem_cgroup *memcg, *old_memcg;
        void *ptr;

        memcg = bpf_map_get_memcg(map);
        old_memcg = set_active_memcg(memcg);
        ptr = kzalloc(size, flags | __GFP_ACCOUNT);
        set_active_memcg(old_memcg);
        mem_cgroup_put(memcg);

        return ptr;
}

void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
                       gfp_t flags)
{
        struct mem_cgroup *memcg, *old_memcg;
        void *ptr;

        memcg = bpf_map_get_memcg(map);
        old_memcg = set_active_memcg(memcg);
        ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
        set_active_memcg(old_memcg);
        mem_cgroup_put(memcg);

        return ptr;
}

void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
                                    size_t align, gfp_t flags)
{
        struct mem_cgroup *memcg, *old_memcg;
        void __percpu *ptr;

        memcg = bpf_map_get_memcg(map);
        old_memcg = set_active_memcg(memcg);
        ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
        set_active_memcg(old_memcg);
        mem_cgroup_put(memcg);

        return ptr;
}

#else
static void bpf_map_save_memcg(struct bpf_map *map)
{
}

static void bpf_map_release_memcg(struct bpf_map *map)
{
}
#endif

static int btf_field_cmp(const void *a, const void *b)
{
        const struct btf_field *f1 = a, *f2 = b;

        if (f1->offset < f2->offset)
                return -1;
        else if (f1->offset > f2->offset)
                return 1;
        return 0;
}

struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
                                  u32 field_mask)
{
        struct btf_field *field;

        if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
                return NULL;
        field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
        if (!field || !(field->type & field_mask))
                return NULL;
        return field;
}

void btf_record_free(struct btf_record *rec)
{
        int i;

        if (IS_ERR_OR_NULL(rec))
                return;
        for (i = 0; i < rec->cnt; i++) {
                switch (rec->fields[i].type) {
                case BPF_KPTR_UNREF:
                case BPF_KPTR_REF:
                case BPF_KPTR_PERCPU:
                        if (rec->fields[i].kptr.module)
                                module_put(rec->fields[i].kptr.module);
                        btf_put(rec->fields[i].kptr.btf);
                        break;
                case BPF_LIST_HEAD:
                case BPF_LIST_NODE:
                case BPF_RB_ROOT:
                case BPF_RB_NODE:
                case BPF_SPIN_LOCK:
                case BPF_TIMER:
                case BPF_REFCOUNT:
                        /* Nothing to release */
                        break;
                default:
                        WARN_ON_ONCE(1);
                        continue;
                }
        }
        kfree(rec);
}

void bpf_map_free_record(struct bpf_map *map)
{
        btf_record_free(map->record);
        map->record = NULL;
}

struct btf_record *btf_record_dup(const struct btf_record *rec)
{
        const struct btf_field *fields;
        struct btf_record *new_rec;
        int ret, size, i;

        if (IS_ERR_OR_NULL(rec))
                return NULL;
        size = offsetof(struct btf_record, fields[rec->cnt]);
        new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
        if (!new_rec)
                return ERR_PTR(-ENOMEM);
        /* Do a deep copy of the btf_record */
        fields = rec->fields;
        new_rec->cnt = 0;
        for (i = 0; i < rec->cnt; i++) {
                switch (fields[i].type) {
                case BPF_KPTR_UNREF:
                case BPF_KPTR_REF:
                case BPF_KPTR_PERCPU:
                        btf_get(fields[i].kptr.btf);
                        if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
                                ret = -ENXIO;
                                goto free;
                        }
                        break;
                case BPF_LIST_HEAD:
                case BPF_LIST_NODE:
                case BPF_RB_ROOT:
                case BPF_RB_NODE:
                case BPF_SPIN_LOCK:
                case BPF_TIMER:
                case BPF_REFCOUNT:
                        /* Nothing to acquire */
                        break;
                default:
                        ret = -EFAULT;
                        WARN_ON_ONCE(1);
                        goto free;
                }
                new_rec->cnt++;
        }
        return new_rec;
free:
        btf_record_free(new_rec);
        return ERR_PTR(ret);
}

bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
{
        bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
        int size;

        if (!a_has_fields && !b_has_fields)
                return true;
        if (a_has_fields != b_has_fields)
                return false;
        if (rec_a->cnt != rec_b->cnt)
                return false;
        size = offsetof(struct btf_record, fields[rec_a->cnt]);
        /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
         * members are zeroed out. So memcmp is safe to do without worrying
         * about padding/unused fields.
         *
         * While spin_lock, timer, and kptr have no relation to map BTF,
         * list_head metadata is specific to map BTF, the btf and value_rec
         * members in particular. btf is the map BTF, while value_rec points to
         * btf_record in that map BTF.
         *
         * So while by default, we don't rely on the map BTF (which the records
         * were parsed from) matching for both records, which is not backwards
         * compatible, in case list_head is part of it, we implicitly rely on
         * that by way of depending on memcmp succeeding for it.
         */
        return !memcmp(rec_a, rec_b, size);
}

void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
{
        if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
                return;
        bpf_timer_cancel_and_free(obj + rec->timer_off);
}

void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
{
        const struct btf_field *fields;
        int i;

        if (IS_ERR_OR_NULL(rec))
                return;
        fields = rec->fields;
        for (i = 0; i < rec->cnt; i++) {
                struct btf_struct_meta *pointee_struct_meta;
                const struct btf_field *field = &fields[i];
                void *field_ptr = obj + field->offset;
                void *xchgd_field;

                switch (fields[i].type) {
                case BPF_SPIN_LOCK:
                        break;
                case BPF_TIMER:
                        bpf_timer_cancel_and_free(field_ptr);
                        break;
                case BPF_KPTR_UNREF:
                        WRITE_ONCE(*(u64 *)field_ptr, 0);
                        break;
                case BPF_KPTR_REF:
                case BPF_KPTR_PERCPU:
                        xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
                        if (!xchgd_field)
                                break;

                        if (!btf_is_kernel(field->kptr.btf)) {
                                pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
                                                                           field->kptr.btf_id);
                                migrate_disable();
                                __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
                                                                 pointee_struct_meta->record : NULL,
                                                                 fields[i].type == BPF_KPTR_PERCPU);
                                migrate_enable();
                        } else {
                                field->kptr.dtor(xchgd_field);
                        }
                        break;
                case BPF_LIST_HEAD:
                        if (WARN_ON_ONCE(rec->spin_lock_off < 0))
                                continue;
                        bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
                        break;
                case BPF_RB_ROOT:
                        if (WARN_ON_ONCE(rec->spin_lock_off < 0))
                                continue;
                        bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
                        break;
                case BPF_LIST_NODE:
                case BPF_RB_NODE:
                case BPF_REFCOUNT:
                        break;
                default:
                        WARN_ON_ONCE(1);
                        continue;
                }
        }
}

/* called from workqueue */
static void bpf_map_free_deferred(struct work_struct *work)
{
        struct bpf_map *map = container_of(work, struct bpf_map, work);
        struct btf_record *rec = map->record;

        security_bpf_map_free(map);
        bpf_map_release_memcg(map);
        /* implementation dependent freeing */
        map->ops->map_free(map);
        /* Delay freeing of btf_record for maps, as map_free
         * callback usually needs access to them. It is better to do it here
         * than require each callback to do the free itself manually.
         *
         * Note that the btf_record stashed in map->inner_map_meta->record was
         * already freed using the map_free callback for map in map case which
         * eventually calls bpf_map_free_meta, since inner_map_meta is only a
         * template bpf_map struct used during verification.
         */
        btf_record_free(rec);
}

static void bpf_map_put_uref(struct bpf_map *map)
{
        if (atomic64_dec_and_test(&map->usercnt)) {
                if (map->ops->map_release_uref)
                        map->ops->map_release_uref(map);
        }
}

/* decrement map refcnt and schedule it for freeing via workqueue
 * (underlying map implementation ops->map_free() might sleep)
 */
void bpf_map_put(struct bpf_map *map)
{
        if (atomic64_dec_and_test(&map->refcnt)) {
                /* bpf_map_free_id() must be called first */
                bpf_map_free_id(map);
                btf_put(map->btf);
                INIT_WORK(&map->work, bpf_map_free_deferred);
                /* Avoid spawning kworkers, since they all might contend
                 * for the same mutex like slab_mutex.
                 */
                queue_work(system_unbound_wq, &map->work);
        }
}
EXPORT_SYMBOL_GPL(bpf_map_put);

void bpf_map_put_with_uref(struct bpf_map *map)
{
        bpf_map_put_uref(map);
        bpf_map_put(map);
}

static int bpf_map_release(struct inode *inode, struct file *filp)
{
        struct bpf_map *map = filp->private_data;

        if (map->ops->map_release)
                map->ops->map_release(map, filp);

        bpf_map_put_with_uref(map);
        return 0;
}

static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
{
        fmode_t mode = f.file->f_mode;

        /* Our file permissions may have been overridden by global
         * map permissions facing syscall side.
         */
        if (READ_ONCE(map->frozen))
                mode &= ~FMODE_CAN_WRITE;
        return mode;
}

#ifdef CONFIG_PROC_FS
/* Show the memory usage of a bpf map */
static u64 bpf_map_memory_usage(const struct bpf_map *map)
{
        return map->ops->map_mem_usage(map);
}

static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
{
        struct bpf_map *map = filp->private_data;
        u32 type = 0, jited = 0;

        if (map_type_contains_progs(map)) {
                spin_lock(&map->owner.lock);
                type  = map->owner.type;
                jited = map->owner.jited;
                spin_unlock(&map->owner.lock);
        }

        seq_printf(m,
                   "map_type:\t%u\n"
                   "key_size:\t%u\n"
                   "value_size:\t%u\n"
                   "max_entries:\t%u\n"
                   "map_flags:\t%#x\n"
                   "map_extra:\t%#llx\n"
                   "memlock:\t%llu\n"
                   "map_id:\t%u\n"
                   "frozen:\t%u\n",
                   map->map_type,
                   map->key_size,
                   map->value_size,
                   map->max_entries,
                   map->map_flags,
                   (unsigned long long)map->map_extra,
                   bpf_map_memory_usage(map),
                   map->id,
                   READ_ONCE(map->frozen));
        if (type) {
                seq_printf(m, "owner_prog_type:\t%u\n", type);
                seq_printf(m, "owner_jited:\t%u\n", jited);
        }
}
#endif

static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
                              loff_t *ppos)
{
        /* We need this handler such that alloc_file() enables
         * f_mode with FMODE_CAN_READ.
         */
        return -EINVAL;
}

static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
                               size_t siz, loff_t *ppos)
{
        /* We need this handler such that alloc_file() enables
         * f_mode with FMODE_CAN_WRITE.
         */
        return -EINVAL;
}

/* called for any extra memory-mapped regions (except initial) */
static void bpf_map_mmap_open(struct vm_area_struct *vma)
{
        struct bpf_map *map = vma->vm_file->private_data;

        if (vma->vm_flags & VM_MAYWRITE)
                bpf_map_write_active_inc(map);
}

/* called for all unmapped memory region (including initial) */
static void bpf_map_mmap_close(struct vm_area_struct *vma)
{
        struct bpf_map *map = vma->vm_file->private_data;

        if (vma->vm_flags & VM_MAYWRITE)
                bpf_map_write_active_dec(map);
}

static const struct vm_operations_struct bpf_map_default_vmops = {
        .open           = bpf_map_mmap_open,
        .close          = bpf_map_mmap_close,
};

static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
{
        struct bpf_map *map = filp->private_data;
        int err;

        if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
                return -ENOTSUPP;

        if (!(vma->vm_flags & VM_SHARED))
                return -EINVAL;

        mutex_lock(&map->freeze_mutex);

        if (vma->vm_flags & VM_WRITE) {
                if (map->frozen) {
                        err = -EPERM;
                        goto out;
                }
                /* map is meant to be read-only, so do not allow mapping as
                 * writable, because it's possible to leak a writable page
                 * reference and allows user-space to still modify it after
                 * freezing, while verifier will assume contents do not change
                 */
                if (map->map_flags & BPF_F_RDONLY_PROG) {
                        err = -EACCES;
                        goto out;
                }
        }

        /* set default open/close callbacks */
        vma->vm_ops = &bpf_map_default_vmops;
        vma->vm_private_data = map;
        vm_flags_clear(vma, VM_MAYEXEC);
        if (!(vma->vm_flags & VM_WRITE))
                /* disallow re-mapping with PROT_WRITE */
                vm_flags_clear(vma, VM_MAYWRITE);

        err = map->ops->map_mmap(map, vma);
        if (err)
                goto out;

        if (vma->vm_flags & VM_MAYWRITE)
                bpf_map_write_active_inc(map);
out:
        mutex_unlock(&map->freeze_mutex);
        return err;
}

static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
{
        struct bpf_map *map = filp->private_data;

        if (map->ops->map_poll)
                return map->ops->map_poll(map, filp, pts);

        return EPOLLERR;
}

const struct file_operations bpf_map_fops = {
#ifdef CONFIG_PROC_FS
        .show_fdinfo    = bpf_map_show_fdinfo,
#endif
        .release        = bpf_map_release,
        .read           = bpf_dummy_read,
        .write          = bpf_dummy_write,
        .mmap           = bpf_map_mmap,
        .poll           = bpf_map_poll,
};

int bpf_map_new_fd(struct bpf_map *map, int flags)
{
        int ret;

        ret = security_bpf_map(map, OPEN_FMODE(flags));
        if (ret < 0)
                return ret;

        return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
                                flags | O_CLOEXEC);
}

int bpf_get_file_flag(int flags)
{
        if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
                return -EINVAL;
        if (flags & BPF_F_RDONLY)
                return O_RDONLY;
        if (flags & BPF_F_WRONLY)
                return O_WRONLY;
        return O_RDWR;
}

/* helper macro to check that unused fields 'union bpf_attr' are zero */
#define CHECK_ATTR(CMD) \
        memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
                   sizeof(attr->CMD##_LAST_FIELD), 0, \
                   sizeof(*attr) - \
                   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
                   sizeof(attr->CMD##_LAST_FIELD)) != NULL

/* dst and src must have at least "size" number of bytes.
 * Return strlen on success and < 0 on error.
 */
int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
{
        const char *end = src + size;
        const char *orig_src = src;

        memset(dst, 0, size);
        /* Copy all isalnum(), '_' and '.' chars. */
        while (src < end && *src) {
                if (!isalnum(*src) &&
                    *src != '_' && *src != '.')
                        return -EINVAL;
                *dst++ = *src++;
        }

        /* No '\0' found in "size" number of bytes */
        if (src == end)
                return -EINVAL;

        return src - orig_src;
}

int map_check_no_btf(const struct bpf_map *map,
                     const struct btf *btf,
                     const struct btf_type *key_type,
                     const struct btf_type *value_type)
{
        return -ENOTSUPP;
}

static int map_check_btf(struct bpf_map *map, const struct btf *btf,
                         u32 btf_key_id, u32 btf_value_id)
{
        const struct btf_type *key_type, *value_type;
        u32 key_size, value_size;
        int ret = 0;

        /* Some maps allow key to be unspecified. */
        if (btf_key_id) {
                key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
                if (!key_type || key_size != map->key_size)
                        return -EINVAL;
        } else {
                key_type = btf_type_by_id(btf, 0);
                if (!map->ops->map_check_btf)
                        return -EINVAL;
        }

        value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
        if (!value_type || value_size != map->value_size)
                return -EINVAL;

        map->record = btf_parse_fields(btf, value_type,
                                       BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
                                       BPF_RB_ROOT | BPF_REFCOUNT,
                                       map->value_size);
        if (!IS_ERR_OR_NULL(map->record)) {
                int i;

                if (!bpf_capable()) {
                        ret = -EPERM;
                        goto free_map_tab;
                }
                if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
                        ret = -EACCES;
                        goto free_map_tab;
                }
                for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
                        switch (map->record->field_mask & (1 << i)) {
                        case 0:
                                continue;
                        case BPF_SPIN_LOCK:
                                if (map->map_type != BPF_MAP_TYPE_HASH &&
                                    map->map_type != BPF_MAP_TYPE_ARRAY &&
                                    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
                                    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
                                    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
                                    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
                                    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
                                        ret = -EOPNOTSUPP;
                                        goto free_map_tab;
                                }
                                break;
                        case BPF_TIMER:
                                if (map->map_type != BPF_MAP_TYPE_HASH &&
                                    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
                                    map->map_type != BPF_MAP_TYPE_ARRAY) {
                                        ret = -EOPNOTSUPP;
                                        goto free_map_tab;
                                }
                                break;
                        case BPF_KPTR_UNREF:
                        case BPF_KPTR_REF:
                        case BPF_KPTR_PERCPU:
                        case BPF_REFCOUNT:
                                if (map->map_type != BPF_MAP_TYPE_HASH &&
                                    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
                                    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
                                    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
                                    map->map_type != BPF_MAP_TYPE_ARRAY &&
                                    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
                                    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
                                    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
                                    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
                                    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
                                        ret = -EOPNOTSUPP;
                                        goto free_map_tab;
                                }
                                break;
                        case BPF_LIST_HEAD:
                        case BPF_RB_ROOT:
                                if (map->map_type != BPF_MAP_TYPE_HASH &&
                                    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
                                    map->map_type != BPF_MAP_TYPE_ARRAY) {
                                        ret = -EOPNOTSUPP;
                                        goto free_map_tab;
                                }
                                break;
                        default:
                                /* Fail if map_type checks are missing for a field type */
                                ret = -EOPNOTSUPP;
                                goto free_map_tab;
                        }
                }
        }

        ret = btf_check_and_fixup_fields(btf, map->record);
        if (ret < 0)
                goto free_map_tab;

        if (map->ops->map_check_btf) {
                ret = map->ops->map_check_btf(map, btf, key_type, value_type);
                if (ret < 0)
                        goto free_map_tab;
        }

        return ret;
free_map_tab:
        bpf_map_free_record(map);
        return ret;
}

#define BPF_MAP_CREATE_LAST_FIELD map_extra
/* called via syscall */
static int map_create(union bpf_attr *attr)
{
        const struct bpf_map_ops *ops;
        int numa_node = bpf_map_attr_numa_node(attr);
        u32 map_type = attr->map_type;
        struct bpf_map *map;
        int f_flags;
        int err;

        err = CHECK_ATTR(BPF_MAP_CREATE);
        if (err)
                return -EINVAL;

        if (attr->btf_vmlinux_value_type_id) {
                if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
                    attr->btf_key_type_id || attr->btf_value_type_id)
                        return -EINVAL;
        } else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
                return -EINVAL;
        }

        if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
            attr->map_extra != 0)
                return -EINVAL;

        f_flags = bpf_get_file_flag(attr->map_flags);
        if (f_flags < 0)
                return f_flags;

        if (numa_node != NUMA_NO_NODE &&
            ((unsigned int)numa_node >= nr_node_ids ||
             !node_online(numa_node)))
                return -EINVAL;

        /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
        map_type = attr->map_type;
        if (map_type >= ARRAY_SIZE(bpf_map_types))
                return -EINVAL;
        map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
        ops = bpf_map_types[map_type];
        if (!ops)
                return -EINVAL;

        if (ops->map_alloc_check) {
                err = ops->map_alloc_check(attr);
                if (err)
                        return err;
        }
        if (attr->map_ifindex)
                ops = &bpf_map_offload_ops;
        if (!ops->map_mem_usage)
                return -EINVAL;

        /* Intent here is for unprivileged_bpf_disabled to block BPF map
         * creation for unprivileged users; other actions depend
         * on fd availability and access to bpffs, so are dependent on
         * object creation success. Even with unprivileged BPF disabled,
         * capability checks are still carried out.
         */
        if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
                return -EPERM;

        /* check privileged map type permissions */
        switch (map_type) {
        case BPF_MAP_TYPE_ARRAY:
        case BPF_MAP_TYPE_PERCPU_ARRAY:
        case BPF_MAP_TYPE_PROG_ARRAY:
        case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
        case BPF_MAP_TYPE_CGROUP_ARRAY:
        case BPF_MAP_TYPE_ARRAY_OF_MAPS:
        case BPF_MAP_TYPE_HASH:
        case BPF_MAP_TYPE_PERCPU_HASH:
        case BPF_MAP_TYPE_HASH_OF_MAPS:
        case BPF_MAP_TYPE_RINGBUF:
        case BPF_MAP_TYPE_USER_RINGBUF:
        case BPF_MAP_TYPE_CGROUP_STORAGE:
        case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
                /* unprivileged */
                break;
        case BPF_MAP_TYPE_SK_STORAGE:
        case BPF_MAP_TYPE_INODE_STORAGE:
        case BPF_MAP_TYPE_TASK_STORAGE:
        case BPF_MAP_TYPE_CGRP_STORAGE:
        case BPF_MAP_TYPE_BLOOM_FILTER:
        case BPF_MAP_TYPE_LPM_TRIE:
        case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
        case BPF_MAP_TYPE_STACK_TRACE:
        case BPF_MAP_TYPE_QUEUE:
        case BPF_MAP_TYPE_STACK:
        case BPF_MAP_TYPE_LRU_HASH:
        case BPF_MAP_TYPE_LRU_PERCPU_HASH:
        case BPF_MAP_TYPE_STRUCT_OPS:
        case BPF_MAP_TYPE_CPUMAP:
                if (!bpf_capable())
                        return -EPERM;
                break;
        case BPF_MAP_TYPE_SOCKMAP:
        case BPF_MAP_TYPE_SOCKHASH:
        case BPF_MAP_TYPE_DEVMAP:
        case BPF_MAP_TYPE_DEVMAP_HASH:
        case BPF_MAP_TYPE_XSKMAP:
                if (!capable(CAP_NET_ADMIN))
                        return -EPERM;
                break;
        default:
                WARN(1, "unsupported map type %d", map_type);
                return -EPERM;
        }

        map = ops->map_alloc(attr);
        if (IS_ERR(map))
                return PTR_ERR(map);
        map->ops = ops;
        map->map_type = map_type;

        err = bpf_obj_name_cpy(map->name, attr->map_name,
                               sizeof(attr->map_name));
        if (err < 0)
                goto free_map;

        atomic64_set(&map->refcnt, 1);
        atomic64_set(&map->usercnt, 1);
        mutex_init(&map->freeze_mutex);
        spin_lock_init(&map->owner.lock);

        if (attr->btf_key_type_id || attr->btf_value_type_id ||
            /* Even the map's value is a kernel's struct,
             * the bpf_prog.o must have BTF to begin with
             * to figure out the corresponding kernel's
             * counter part.  Thus, attr->btf_fd has
             * to be valid also.
             */
            attr->btf_vmlinux_value_type_id) {
                struct btf *btf;

                btf = btf_get_by_fd(attr->btf_fd);
                if (IS_ERR(btf)) {
                        err = PTR_ERR(btf);
                        goto free_map;
                }
                if (btf_is_kernel(btf)) {
                        btf_put(btf);
                        err = -EACCES;
                        goto free_map;
                }
                map->btf = btf;

                if (attr->btf_value_type_id) {
                        err = map_check_btf(map, btf, attr->btf_key_type_id,
                                            attr->btf_value_type_id);
                        if (err)
                                goto free_map;
                }

                map->btf_key_type_id = attr->btf_key_type_id;
                map->btf_value_type_id = attr->btf_value_type_id;
                map->btf_vmlinux_value_type_id =
                        attr->btf_vmlinux_value_type_id;
        }

        err = security_bpf_map_alloc(map);
        if (err)
                goto free_map;

        err = bpf_map_alloc_id(map);
        if (err)
                goto free_map_sec;

        bpf_map_save_memcg(map);

        err = bpf_map_new_fd(map, f_flags);
        if (err < 0) {
                /* failed to allocate fd.
                 * bpf_map_put_with_uref() is needed because the above
                 * bpf_map_alloc_id() has published the map
                 * to the userspace and the userspace may
                 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
                 */
                bpf_map_put_with_uref(map);
                return err;
        }

        return err;

free_map_sec:
        security_bpf_map_free(map);
free_map:
        btf_put(map->btf);
        map->ops->map_free(map);
        return err;
}

/* if error is returned, fd is released.
 * On success caller should complete fd access with matching fdput()
 */
struct bpf_map *__bpf_map_get(struct fd f)
{
        if (!f.file)
                return ERR_PTR(-EBADF);
        if (f.file->f_op != &bpf_map_fops) {
                fdput(f);
                return ERR_PTR(-EINVAL);
        }

        return f.file->private_data;
}

void bpf_map_inc(struct bpf_map *map)
{
        atomic64_inc(&map->refcnt);
}
EXPORT_SYMBOL_GPL(bpf_map_inc);

void bpf_map_inc_with_uref(struct bpf_map *map)
{
        atomic64_inc(&map->refcnt);
        atomic64_inc(&map->usercnt);
}
EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);

struct bpf_map *bpf_map_get(u32 ufd)
{
        struct fd f = fdget(ufd);
        struct bpf_map *map;

        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return map;

        bpf_map_inc(map);
        fdput(f);

        return map;
}
EXPORT_SYMBOL(bpf_map_get);

struct bpf_map *bpf_map_get_with_uref(u32 ufd)
{
        struct fd f = fdget(ufd);
        struct bpf_map *map;

        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return map;

        bpf_map_inc_with_uref(map);
        fdput(f);

        return map;
}

/* map_idr_lock should have been held or the map should have been
 * protected by rcu read lock.
 */
struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
{
        int refold;

        refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
        if (!refold)
                return ERR_PTR(-ENOENT);
        if (uref)
                atomic64_inc(&map->usercnt);

        return map;
}

struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
{
        spin_lock_bh(&map_idr_lock);
        map = __bpf_map_inc_not_zero(map, false);
        spin_unlock_bh(&map_idr_lock);

        return map;
}
EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);

int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
{
        return -ENOTSUPP;
}

static void *__bpf_copy_key(void __user *ukey, u64 key_size)
{
        if (key_size)
                return vmemdup_user(ukey, key_size);

        if (ukey)
                return ERR_PTR(-EINVAL);

        return NULL;
}

static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
{
        if (key_size)
                return kvmemdup_bpfptr(ukey, key_size);

        if (!bpfptr_is_null(ukey))
                return ERR_PTR(-EINVAL);

        return NULL;
}

/* last field in 'union bpf_attr' used by this command */
#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags

static int map_lookup_elem(union bpf_attr *attr)
{
        void __user *ukey = u64_to_user_ptr(attr->key);
        void __user *uvalue = u64_to_user_ptr(attr->value);
        int ufd = attr->map_fd;
        struct bpf_map *map;
        void *key, *value;
        u32 value_size;
        struct fd f;
        int err;

        if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
                return -EINVAL;

        if (attr->flags & ~BPF_F_LOCK)
                return -EINVAL;

        f = fdget(ufd);
        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return PTR_ERR(map);
        if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
                err = -EPERM;
                goto err_put;
        }

        if ((attr->flags & BPF_F_LOCK) &&
            !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
                err = -EINVAL;
                goto err_put;
        }

        key = __bpf_copy_key(ukey, map->key_size);
        if (IS_ERR(key)) {
                err = PTR_ERR(key);
                goto err_put;
        }

        value_size = bpf_map_value_size(map);

        err = -ENOMEM;
        value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
        if (!value)
                goto free_key;

        if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
                if (copy_from_user(value, uvalue, value_size))
                        err = -EFAULT;
                else
                        err = bpf_map_copy_value(map, key, value, attr->flags);
                goto free_value;
        }

        err = bpf_map_copy_value(map, key, value, attr->flags);
        if (err)
                goto free_value;

        err = -EFAULT;
        if (copy_to_user(uvalue, value, value_size) != 0)
                goto free_value;

        err = 0;

free_value:
        kvfree(value);
free_key:
        kvfree(key);
err_put:
        fdput(f);
        return err;
}


#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags

static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
{
        bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
        bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
        int ufd = attr->map_fd;
        struct bpf_map *map;
        void *key, *value;
        u32 value_size;
        struct fd f;
        int err;

        if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
                return -EINVAL;

        f = fdget(ufd);
        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return PTR_ERR(map);
        bpf_map_write_active_inc(map);
        if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
                err = -EPERM;
                goto err_put;
        }

        if ((attr->flags & BPF_F_LOCK) &&
            !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
                err = -EINVAL;
                goto err_put;
        }

        key = ___bpf_copy_key(ukey, map->key_size);
        if (IS_ERR(key)) {
                err = PTR_ERR(key);
                goto err_put;
        }

        value_size = bpf_map_value_size(map);
        value = kvmemdup_bpfptr(uvalue, value_size);
        if (IS_ERR(value)) {
                err = PTR_ERR(value);
                goto free_key;
        }

        err = bpf_map_update_value(map, f.file, key, value, attr->flags);

        kvfree(value);
free_key:
        kvfree(key);
err_put:
        bpf_map_write_active_dec(map);
        fdput(f);
        return err;
}

#define BPF_MAP_DELETE_ELEM_LAST_FIELD key

static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
{
        bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
        int ufd = attr->map_fd;
        struct bpf_map *map;
        struct fd f;
        void *key;
        int err;

        if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
                return -EINVAL;

        f = fdget(ufd);
        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return PTR_ERR(map);
        bpf_map_write_active_inc(map);
        if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
                err = -EPERM;
                goto err_put;
        }

        key = ___bpf_copy_key(ukey, map->key_size);
        if (IS_ERR(key)) {
                err = PTR_ERR(key);
                goto err_put;
        }

        if (bpf_map_is_offloaded(map)) {
                err = bpf_map_offload_delete_elem(map, key);
                goto out;
        } else if (IS_FD_PROG_ARRAY(map) ||
                   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
                /* These maps require sleepable context */
                err = map->ops->map_delete_elem(map, key);
                goto out;
        }

        bpf_disable_instrumentation();
        rcu_read_lock();
        err = map->ops->map_delete_elem(map, key);
        rcu_read_unlock();
        bpf_enable_instrumentation();
        maybe_wait_bpf_programs(map);
out:
        kvfree(key);
err_put:
        bpf_map_write_active_dec(map);
        fdput(f);
        return err;
}

/* last field in 'union bpf_attr' used by this command */
#define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key

static int map_get_next_key(union bpf_attr *attr)
{
        void __user *ukey = u64_to_user_ptr(attr->key);
        void __user *unext_key = u64_to_user_ptr(attr->next_key);
        int ufd = attr->map_fd;
        struct bpf_map *map;
        void *key, *next_key;
        struct fd f;
        int err;

        if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
                return -EINVAL;

        f = fdget(ufd);
        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return PTR_ERR(map);
        if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
                err = -EPERM;
                goto err_put;
        }

        if (ukey) {
                key = __bpf_copy_key(ukey, map->key_size);
                if (IS_ERR(key)) {
                        err = PTR_ERR(key);
                        goto err_put;
                }
        } else {
                key = NULL;
        }

        err = -ENOMEM;
        next_key = kvmalloc(map->key_size, GFP_USER);
        if (!next_key)
                goto free_key;

        if (bpf_map_is_offloaded(map)) {
                err = bpf_map_offload_get_next_key(map, key, next_key);
                goto out;
        }

        rcu_read_lock();
        err = map->ops->map_get_next_key(map, key, next_key);
        rcu_read_unlock();
out:
        if (err)
                goto free_next_key;

        err = -EFAULT;
        if (copy_to_user(unext_key, next_key, map->key_size) != 0)
                goto free_next_key;

        err = 0;

free_next_key:
        kvfree(next_key);
free_key:
        kvfree(key);
err_put:
        fdput(f);
        return err;
}

int generic_map_delete_batch(struct bpf_map *map,
                             const union bpf_attr *attr,
                             union bpf_attr __user *uattr)
{
        void __user *keys = u64_to_user_ptr(attr->batch.keys);
        u32 cp, max_count;
        int err = 0;
        void *key;

        if (attr->batch.elem_flags & ~BPF_F_LOCK)
                return -EINVAL;

        if ((attr->batch.elem_flags & BPF_F_LOCK) &&
            !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
                return -EINVAL;
        }

        max_count = attr->batch.count;
        if (!max_count)
                return 0;

        key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
        if (!key)
                return -ENOMEM;

        for (cp = 0; cp < max_count; cp++) {
                err = -EFAULT;
                if (copy_from_user(key, keys + cp * map->key_size,
                                   map->key_size))
                        break;

                if (bpf_map_is_offloaded(map)) {
                        err = bpf_map_offload_delete_elem(map, key);
                        break;
                }

                bpf_disable_instrumentation();
                rcu_read_lock();
                err = map->ops->map_delete_elem(map, key);
                rcu_read_unlock();
                bpf_enable_instrumentation();
                if (err)
                        break;
                cond_resched();
        }
        if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
                err = -EFAULT;

        kvfree(key);

        maybe_wait_bpf_programs(map);
        return err;
}

int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
                             const union bpf_attr *attr,
                             union bpf_attr __user *uattr)
{
        void __user *values = u64_to_user_ptr(attr->batch.values);
        void __user *keys = u64_to_user_ptr(attr->batch.keys);
        u32 value_size, cp, max_count;
        void *key, *value;
        int err = 0;

        if (attr->batch.elem_flags & ~BPF_F_LOCK)
                return -EINVAL;

        if ((attr->batch.elem_flags & BPF_F_LOCK) &&
            !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
                return -EINVAL;
        }

        value_size = bpf_map_value_size(map);

        max_count = attr->batch.count;
        if (!max_count)
                return 0;

        key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
        if (!key)
                return -ENOMEM;

        value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
        if (!value) {
                kvfree(key);
                return -ENOMEM;
        }

        for (cp = 0; cp < max_count; cp++) {
                err = -EFAULT;
                if (copy_from_user(key, keys + cp * map->key_size,
                    map->key_size) ||
                    copy_from_user(value, values + cp * value_size, value_size))
                        break;

                err = bpf_map_update_value(map, map_file, key, value,
                                           attr->batch.elem_flags);

                if (err)
                        break;
                cond_resched();
        }

        if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
                err = -EFAULT;

        kvfree(value);
        kvfree(key);
        return err;
}

#define MAP_LOOKUP_RETRIES 3

int generic_map_lookup_batch(struct bpf_map *map,
                                    const union bpf_attr *attr,
                                    union bpf_attr __user *uattr)
{
        void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
        void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
        void __user *values = u64_to_user_ptr(attr->batch.values);
        void __user *keys = u64_to_user_ptr(attr->batch.keys);
        void *buf, *buf_prevkey, *prev_key, *key, *value;
        int err, retry = MAP_LOOKUP_RETRIES;
        u32 value_size, cp, max_count;

        if (attr->batch.elem_flags & ~BPF_F_LOCK)
                return -EINVAL;

        if ((attr->batch.elem_flags & BPF_F_LOCK) &&
            !btf_record_has_field(map->record, BPF_SPIN_LOCK))
                return -EINVAL;

        value_size = bpf_map_value_size(map);

        max_count = attr->batch.count;
        if (!max_count)
                return 0;

        if (put_user(0, &uattr->batch.count))
                return -EFAULT;

        buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
        if (!buf_prevkey)
                return -ENOMEM;

        buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
        if (!buf) {
                kvfree(buf_prevkey);
                return -ENOMEM;
        }

        err = -EFAULT;
        prev_key = NULL;
        if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
                goto free_buf;
        key = buf;
        value = key + map->key_size;
        if (ubatch)
                prev_key = buf_prevkey;

        for (cp = 0; cp < max_count;) {
                rcu_read_lock();
                err = map->ops->map_get_next_key(map, prev_key, key);
                rcu_read_unlock();
                if (err)
                        break;
                err = bpf_map_copy_value(map, key, value,
                                         attr->batch.elem_flags);

                if (err == -ENOENT) {
                        if (retry) {
                                retry--;
                                continue;
                        }
                        err = -EINTR;
                        break;
                }

                if (err)
                        goto free_buf;

                if (copy_to_user(keys + cp * map->key_size, key,
                                 map->key_size)) {
                        err = -EFAULT;
                        goto free_buf;
                }
                if (copy_to_user(values + cp * value_size, value, value_size)) {
                        err = -EFAULT;
                        goto free_buf;
                }

                if (!prev_key)
                        prev_key = buf_prevkey;

                swap(prev_key, key);
                retry = MAP_LOOKUP_RETRIES;
                cp++;
                cond_resched();
        }

        if (err == -EFAULT)
                goto free_buf;

        if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
                    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
                err = -EFAULT;

free_buf:
        kvfree(buf_prevkey);
        kvfree(buf);
        return err;
}

#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags

static int map_lookup_and_delete_elem(union bpf_attr *attr)
{
        void __user *ukey = u64_to_user_ptr(attr->key);
        void __user *uvalue = u64_to_user_ptr(attr->value);
        int ufd = attr->map_fd;
        struct bpf_map *map;
        void *key, *value;
        u32 value_size;
        struct fd f;
        int err;

        if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
                return -EINVAL;

        if (attr->flags & ~BPF_F_LOCK)
                return -EINVAL;

        f = fdget(ufd);
        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return PTR_ERR(map);
        bpf_map_write_active_inc(map);
        if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
            !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
                err = -EPERM;
                goto err_put;
        }

        if (attr->flags &&
            (map->map_type == BPF_MAP_TYPE_QUEUE ||
             map->map_type == BPF_MAP_TYPE_STACK)) {
                err = -EINVAL;
                goto err_put;
        }

        if ((attr->flags & BPF_F_LOCK) &&
            !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
                err = -EINVAL;
                goto err_put;
        }

        key = __bpf_copy_key(ukey, map->key_size);
        if (IS_ERR(key)) {
                err = PTR_ERR(key);
                goto err_put;
        }

        value_size = bpf_map_value_size(map);

        err = -ENOMEM;
        value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
        if (!value)
                goto free_key;

        err = -ENOTSUPP;
        if (map->map_type == BPF_MAP_TYPE_QUEUE ||
            map->map_type == BPF_MAP_TYPE_STACK) {
                err = map->ops->map_pop_elem(map, value);
        } else if (map->map_type == BPF_MAP_TYPE_HASH ||
                   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
                   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
                   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
                if (!bpf_map_is_offloaded(map)) {
                        bpf_disable_instrumentation();
                        rcu_read_lock();
                        err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
                        rcu_read_unlock();
                        bpf_enable_instrumentation();
                }
        }

        if (err)
                goto free_value;

        if (copy_to_user(uvalue, value, value_size) != 0) {
                err = -EFAULT;
                goto free_value;
        }

        err = 0;

free_value:
        kvfree(value);
free_key:
        kvfree(key);
err_put:
        bpf_map_write_active_dec(map);
        fdput(f);
        return err;
}

#define BPF_MAP_FREEZE_LAST_FIELD map_fd

static int map_freeze(const union bpf_attr *attr)
{
        int err = 0, ufd = attr->map_fd;
        struct bpf_map *map;
        struct fd f;

        if (CHECK_ATTR(BPF_MAP_FREEZE))
                return -EINVAL;

        f = fdget(ufd);
        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return PTR_ERR(map);

        if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) {
                fdput(f);
                return -ENOTSUPP;
        }

        if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
                fdput(f);
                return -EPERM;
        }

        mutex_lock(&map->freeze_mutex);
        if (bpf_map_write_active(map)) {
                err = -EBUSY;
                goto err_put;
        }
        if (READ_ONCE(map->frozen)) {
                err = -EBUSY;
                goto err_put;
        }

        WRITE_ONCE(map->frozen, true);
err_put:
        mutex_unlock(&map->freeze_mutex);
        fdput(f);
        return err;
}

static const struct bpf_prog_ops * const bpf_prog_types[] = {
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
        [_id] = & _name ## _prog_ops,
#define BPF_MAP_TYPE(_id, _ops)
#define BPF_LINK_TYPE(_id, _name)
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
#undef BPF_LINK_TYPE
};

static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
{
        const struct bpf_prog_ops *ops;

        if (type >= ARRAY_SIZE(bpf_prog_types))
                return -EINVAL;
        type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
        ops = bpf_prog_types[type];
        if (!ops)
                return -EINVAL;

        if (!bpf_prog_is_offloaded(prog->aux))
                prog->aux->ops = ops;
        else
                prog->aux->ops = &bpf_offload_prog_ops;
        prog->type = type;
        return 0;
}

enum bpf_audit {
        BPF_AUDIT_LOAD,
        BPF_AUDIT_UNLOAD,
        BPF_AUDIT_MAX,
};

static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
        [BPF_AUDIT_LOAD]   = "LOAD",
        [BPF_AUDIT_UNLOAD] = "UNLOAD",
};

static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
{
        struct audit_context *ctx = NULL;
        struct audit_buffer *ab;

        if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
                return;
        if (audit_enabled == AUDIT_OFF)
                return;
        if (!in_irq() && !irqs_disabled())
                ctx = audit_context();
        ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
        if (unlikely(!ab))
                return;
        audit_log_format(ab, "prog-id=%u op=%s",
                         prog->aux->id, bpf_audit_str[op]);
        audit_log_end(ab);
}

static int bpf_prog_alloc_id(struct bpf_prog *prog)
{
        int id;

        idr_preload(GFP_KERNEL);
        spin_lock_bh(&prog_idr_lock);
        id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
        if (id > 0)
                prog->aux->id = id;
        spin_unlock_bh(&prog_idr_lock);
        idr_preload_end();

        /* id is in [1, INT_MAX) */
        if (WARN_ON_ONCE(!id))
                return -ENOSPC;

        return id > 0 ? 0 : id;
}

void bpf_prog_free_id(struct bpf_prog *prog)
{
        unsigned long flags;

        /* cBPF to eBPF migrations are currently not in the idr store.
         * Offloaded programs are removed from the store when their device
         * disappears - even if someone grabs an fd to them they are unusable,
         * simply waiting for refcnt to drop to be freed.
         */
        if (!prog->aux->id)
                return;

        spin_lock_irqsave(&prog_idr_lock, flags);
        idr_remove(&prog_idr, prog->aux->id);
        prog->aux->id = 0;
        spin_unlock_irqrestore(&prog_idr_lock, flags);
}

static void __bpf_prog_put_rcu(struct rcu_head *rcu)
{
        struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);

        kvfree(aux->func_info);
        kfree(aux->func_info_aux);
        free_uid(aux->user);
        security_bpf_prog_free(aux);
        bpf_prog_free(aux->prog);
}

static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
{
        bpf_prog_kallsyms_del_all(prog);
        btf_put(prog->aux->btf);
        module_put(prog->aux->mod);
        kvfree(prog->aux->jited_linfo);
        kvfree(prog->aux->linfo);
        kfree(prog->aux->kfunc_tab);
        if (prog->aux->attach_btf)
                btf_put(prog->aux->attach_btf);

        if (deferred) {
                if (prog->aux->sleepable)
                        call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
                else
                        call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
        } else {
                __bpf_prog_put_rcu(&prog->aux->rcu);
        }
}

static void bpf_prog_put_deferred(struct work_struct *work)
{
        struct bpf_prog_aux *aux;
        struct bpf_prog *prog;

        aux = container_of(work, struct bpf_prog_aux, work);
        prog = aux->prog;
        perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
        bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
        bpf_prog_free_id(prog);
        __bpf_prog_put_noref(prog, true);
}

static void __bpf_prog_put(struct bpf_prog *prog)
{
        struct bpf_prog_aux *aux = prog->aux;

        if (atomic64_dec_and_test(&aux->refcnt)) {
                if (in_irq() || irqs_disabled()) {
                        INIT_WORK(&aux->work, bpf_prog_put_deferred);
                        schedule_work(&aux->work);
                } else {
                        bpf_prog_put_deferred(&aux->work);
                }
        }
}

void bpf_prog_put(struct bpf_prog *prog)
{
        __bpf_prog_put(prog);
}
EXPORT_SYMBOL_GPL(bpf_prog_put);

static int bpf_prog_release(struct inode *inode, struct file *filp)
{
        struct bpf_prog *prog = filp->private_data;

        bpf_prog_put(prog);
        return 0;
}

struct bpf_prog_kstats {
        u64 nsecs;
        u64 cnt;
        u64 misses;
};

void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
{
        struct bpf_prog_stats *stats;
        unsigned int flags;

        stats = this_cpu_ptr(prog->stats);
        flags = u64_stats_update_begin_irqsave(&stats->syncp);
        u64_stats_inc(&stats->misses);
        u64_stats_update_end_irqrestore(&stats->syncp, flags);
}

static void bpf_prog_get_stats(const struct bpf_prog *prog,
                               struct bpf_prog_kstats *stats)
{
        u64 nsecs = 0, cnt = 0, misses = 0;
        int cpu;

        for_each_possible_cpu(cpu) {
                const struct bpf_prog_stats *st;
                unsigned int start;
                u64 tnsecs, tcnt, tmisses;

                st = per_cpu_ptr(prog->stats, cpu);
                do {
                        start = u64_stats_fetch_begin(&st->syncp);
                        tnsecs = u64_stats_read(&st->nsecs);
                        tcnt = u64_stats_read(&st->cnt);
                        tmisses = u64_stats_read(&st->misses);
                } while (u64_stats_fetch_retry(&st->syncp, start));
                nsecs += tnsecs;
                cnt += tcnt;
                misses += tmisses;
        }
        stats->nsecs = nsecs;
        stats->cnt = cnt;
        stats->misses = misses;
}

#ifdef CONFIG_PROC_FS
static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
{
        const struct bpf_prog *prog = filp->private_data;
        char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
        struct bpf_prog_kstats stats;

        bpf_prog_get_stats(prog, &stats);
        bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
        seq_printf(m,
                   "prog_type:\t%u\n"
                   "prog_jited:\t%u\n"
                   "prog_tag:\t%s\n"
                   "memlock:\t%llu\n"
                   "prog_id:\t%u\n"
                   "run_time_ns:\t%llu\n"
                   "run_cnt:\t%llu\n"
                   "recursion_misses:\t%llu\n"
                   "verified_insns:\t%u\n",
                   prog->type,
                   prog->jited,
                   prog_tag,
                   prog->pages * 1ULL << PAGE_SHIFT,
                   prog->aux->id,
                   stats.nsecs,
                   stats.cnt,
                   stats.misses,
                   prog->aux->verified_insns);
}
#endif

const struct file_operations bpf_prog_fops = {
#ifdef CONFIG_PROC_FS
        .show_fdinfo    = bpf_prog_show_fdinfo,
#endif
        .release        = bpf_prog_release,
        .read           = bpf_dummy_read,
        .write          = bpf_dummy_write,
};

int bpf_prog_new_fd(struct bpf_prog *prog)
{
        int ret;

        ret = security_bpf_prog(prog);
        if (ret < 0)
                return ret;

        return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
                                O_RDWR | O_CLOEXEC);
}

static struct bpf_prog *____bpf_prog_get(struct fd f)
{
        if (!f.file)
                return ERR_PTR(-EBADF);
        if (f.file->f_op != &bpf_prog_fops) {
                fdput(f);
                return ERR_PTR(-EINVAL);
        }

        return f.file->private_data;
}

void bpf_prog_add(struct bpf_prog *prog, int i)
{
        atomic64_add(i, &prog->aux->refcnt);
}
EXPORT_SYMBOL_GPL(bpf_prog_add);

void bpf_prog_sub(struct bpf_prog *prog, int i)
{
        /* Only to be used for undoing previous bpf_prog_add() in some
         * error path. We still know that another entity in our call
         * path holds a reference to the program, thus atomic_sub() can
         * be safely used in such cases!
         */
        WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
}
EXPORT_SYMBOL_GPL(bpf_prog_sub);

void bpf_prog_inc(struct bpf_prog *prog)
{
        atomic64_inc(&prog->aux->refcnt);
}
EXPORT_SYMBOL_GPL(bpf_prog_inc);

/* prog_idr_lock should have been held */
struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
{
        int refold;

        refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);

        if (!refold)
                return ERR_PTR(-ENOENT);

        return prog;
}
EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);

bool bpf_prog_get_ok(struct bpf_prog *prog,
                            enum bpf_prog_type *attach_type, bool attach_drv)
{
        /* not an attachment, just a refcount inc, always allow */
        if (!attach_type)
                return true;

        if (prog->type != *attach_type)
                return false;
        if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
                return false;

        return true;
}

static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
                                       bool attach_drv)
{
        struct fd f = fdget(ufd);
        struct bpf_prog *prog;

        prog = ____bpf_prog_get(f);
        if (IS_ERR(prog))
                return prog;
        if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
                prog = ERR_PTR(-EINVAL);
                goto out;
        }

        bpf_prog_inc(prog);
out:
        fdput(f);
        return prog;
}

struct bpf_prog *bpf_prog_get(u32 ufd)
{
        return __bpf_prog_get(ufd, NULL, false);
}

struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
                                       bool attach_drv)
{
        return __bpf_prog_get(ufd, &type, attach_drv);
}
EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);

/* Initially all BPF programs could be loaded w/o specifying
 * expected_attach_type. Later for some of them specifying expected_attach_type
 * at load time became required so that program could be validated properly.
 * Programs of types that are allowed to be loaded both w/ and w/o (for
 * backward compatibility) expected_attach_type, should have the default attach
 * type assigned to expected_attach_type for the latter case, so that it can be
 * validated later at attach time.
 *
 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
 * prog type requires it but has some attach types that have to be backward
 * compatible.
 */
static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
{
        switch (attr->prog_type) {
        case BPF_PROG_TYPE_CGROUP_SOCK:
                /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
                 * exist so checking for non-zero is the way to go here.
                 */
                if (!attr->expected_attach_type)
                        attr->expected_attach_type =
                                BPF_CGROUP_INET_SOCK_CREATE;
                break;
        case BPF_PROG_TYPE_SK_REUSEPORT:
                if (!attr->expected_attach_type)
                        attr->expected_attach_type =
                                BPF_SK_REUSEPORT_SELECT;
                break;
        }
}

static int
bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
                           enum bpf_attach_type expected_attach_type,
                           struct btf *attach_btf, u32 btf_id,
                           struct bpf_prog *dst_prog)
{
        if (btf_id) {
                if (btf_id > BTF_MAX_TYPE)
                        return -EINVAL;

                if (!attach_btf && !dst_prog)
                        return -EINVAL;

                switch (prog_type) {
                case BPF_PROG_TYPE_TRACING:
                case BPF_PROG_TYPE_LSM:
                case BPF_PROG_TYPE_STRUCT_OPS:
                case BPF_PROG_TYPE_EXT:
                        break;
                default:
                        return -EINVAL;
                }
        }

        if (attach_btf && (!btf_id || dst_prog))
                return -EINVAL;

        if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
            prog_type != BPF_PROG_TYPE_EXT)
                return -EINVAL;

        switch (prog_type) {
        case BPF_PROG_TYPE_CGROUP_SOCK:
                switch (expected_attach_type) {
                case BPF_CGROUP_INET_SOCK_CREATE:
                case BPF_CGROUP_INET_SOCK_RELEASE:
                case BPF_CGROUP_INET4_POST_BIND:
                case BPF_CGROUP_INET6_POST_BIND:
                        return 0;
                default:
                        return -EINVAL;
                }
        case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
                switch (expected_attach_type) {
                case BPF_CGROUP_INET4_BIND:
                case BPF_CGROUP_INET6_BIND:
                case BPF_CGROUP_INET4_CONNECT:
                case BPF_CGROUP_INET6_CONNECT:
                case BPF_CGROUP_UNIX_CONNECT:
                case BPF_CGROUP_INET4_GETPEERNAME:
                case BPF_CGROUP_INET6_GETPEERNAME:
                case BPF_CGROUP_UNIX_GETPEERNAME:
                case BPF_CGROUP_INET4_GETSOCKNAME:
                case BPF_CGROUP_INET6_GETSOCKNAME:
                case BPF_CGROUP_UNIX_GETSOCKNAME:
                case BPF_CGROUP_UDP4_SENDMSG:
                case BPF_CGROUP_UDP6_SENDMSG:
                case BPF_CGROUP_UNIX_SENDMSG:
                case BPF_CGROUP_UDP4_RECVMSG:
                case BPF_CGROUP_UDP6_RECVMSG:
                case BPF_CGROUP_UNIX_RECVMSG:
                        return 0;
                default:
                        return -EINVAL;
                }
        case BPF_PROG_TYPE_CGROUP_SKB:
                switch (expected_attach_type) {
                case BPF_CGROUP_INET_INGRESS:
                case BPF_CGROUP_INET_EGRESS:
                        return 0;
                default:
                        return -EINVAL;
                }
        case BPF_PROG_TYPE_CGROUP_SOCKOPT:
                switch (expected_attach_type) {
                case BPF_CGROUP_SETSOCKOPT:
                case BPF_CGROUP_GETSOCKOPT:
                        return 0;
                default:
                        return -EINVAL;
                }
        case BPF_PROG_TYPE_SK_LOOKUP:
                if (expected_attach_type == BPF_SK_LOOKUP)
                        return 0;
                return -EINVAL;
        case BPF_PROG_TYPE_SK_REUSEPORT:
                switch (expected_attach_type) {
                case BPF_SK_REUSEPORT_SELECT:
                case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
                        return 0;
                default:
                        return -EINVAL;
                }
        case BPF_PROG_TYPE_NETFILTER:
                if (expected_attach_type == BPF_NETFILTER)
                        return 0;
                return -EINVAL;
        case BPF_PROG_TYPE_SYSCALL:
        case BPF_PROG_TYPE_EXT:
                if (expected_attach_type)
                        return -EINVAL;
                fallthrough;
        default:
                return 0;
        }
}

static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
{
        switch (prog_type) {
        case BPF_PROG_TYPE_SCHED_CLS:
        case BPF_PROG_TYPE_SCHED_ACT:
        case BPF_PROG_TYPE_XDP:
        case BPF_PROG_TYPE_LWT_IN:
        case BPF_PROG_TYPE_LWT_OUT:
        case BPF_PROG_TYPE_LWT_XMIT:
        case BPF_PROG_TYPE_LWT_SEG6LOCAL:
        case BPF_PROG_TYPE_SK_SKB:
        case BPF_PROG_TYPE_SK_MSG:
        case BPF_PROG_TYPE_FLOW_DISSECTOR:
        case BPF_PROG_TYPE_CGROUP_DEVICE:
        case BPF_PROG_TYPE_CGROUP_SOCK:
        case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
        case BPF_PROG_TYPE_CGROUP_SOCKOPT:
        case BPF_PROG_TYPE_CGROUP_SYSCTL:
        case BPF_PROG_TYPE_SOCK_OPS:
        case BPF_PROG_TYPE_EXT: /* extends any prog */
        case BPF_PROG_TYPE_NETFILTER:
                return true;
        case BPF_PROG_TYPE_CGROUP_SKB:
                /* always unpriv */
        case BPF_PROG_TYPE_SK_REUSEPORT:
                /* equivalent to SOCKET_FILTER. need CAP_BPF only */
        default:
                return false;
        }
}

static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
{
        switch (prog_type) {
        case BPF_PROG_TYPE_KPROBE:
        case BPF_PROG_TYPE_TRACEPOINT:
        case BPF_PROG_TYPE_PERF_EVENT:
        case BPF_PROG_TYPE_RAW_TRACEPOINT:
        case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
        case BPF_PROG_TYPE_TRACING:
        case BPF_PROG_TYPE_LSM:
        case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
        case BPF_PROG_TYPE_EXT: /* extends any prog */
                return true;
        default:
                return false;
        }
}

/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD log_true_size

static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
{
        enum bpf_prog_type type = attr->prog_type;
        struct bpf_prog *prog, *dst_prog = NULL;
        struct btf *attach_btf = NULL;
        int err;
        char license[128];

        if (CHECK_ATTR(BPF_PROG_LOAD))
                return -EINVAL;

        if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
                                 BPF_F_ANY_ALIGNMENT |
                                 BPF_F_TEST_STATE_FREQ |
                                 BPF_F_SLEEPABLE |
                                 BPF_F_TEST_RND_HI32 |
                                 BPF_F_XDP_HAS_FRAGS |
                                 BPF_F_XDP_DEV_BOUND_ONLY |
                                 BPF_F_TEST_REG_INVARIANTS))
                return -EINVAL;

        if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
            (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
            !bpf_capable())
                return -EPERM;

        /* Intent here is for unprivileged_bpf_disabled to block BPF program
         * creation for unprivileged users; other actions depend
         * on fd availability and access to bpffs, so are dependent on
         * object creation success. Even with unprivileged BPF disabled,
         * capability checks are still carried out for these
         * and other operations.
         */
        if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
                return -EPERM;

        if (attr->insn_cnt == 0 ||
            attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
                return -E2BIG;
        if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
            type != BPF_PROG_TYPE_CGROUP_SKB &&
            !bpf_capable())
                return -EPERM;

        if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (is_perfmon_prog_type(type) && !perfmon_capable())
                return -EPERM;

        /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
         * or btf, we need to check which one it is
         */
        if (attr->attach_prog_fd) {
                dst_prog = bpf_prog_get(attr->attach_prog_fd);
                if (IS_ERR(dst_prog)) {
                        dst_prog = NULL;
                        attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
                        if (IS_ERR(attach_btf))
                                return -EINVAL;
                        if (!btf_is_kernel(attach_btf)) {
                                /* attaching through specifying bpf_prog's BTF
                                 * objects directly might be supported eventually
                                 */
                                btf_put(attach_btf);
                                return -ENOTSUPP;
                        }
                }
        } else if (attr->attach_btf_id) {
                /* fall back to vmlinux BTF, if BTF type ID is specified */
                attach_btf = bpf_get_btf_vmlinux();
                if (IS_ERR(attach_btf))
                        return PTR_ERR(attach_btf);
                if (!attach_btf)
                        return -EINVAL;
                btf_get(attach_btf);
        }

        bpf_prog_load_fixup_attach_type(attr);
        if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
                                       attach_btf, attr->attach_btf_id,
                                       dst_prog)) {
                if (dst_prog)
                        bpf_prog_put(dst_prog);
                if (attach_btf)
                        btf_put(attach_btf);
                return -EINVAL;
        }

        /* plain bpf_prog allocation */
        prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
        if (!prog) {
                if (dst_prog)
                        bpf_prog_put(dst_prog);
                if (attach_btf)
                        btf_put(attach_btf);
                return -ENOMEM;
        }

        prog->expected_attach_type = attr->expected_attach_type;
        prog->aux->attach_btf = attach_btf;
        prog->aux->attach_btf_id = attr->attach_btf_id;
        prog->aux->dst_prog = dst_prog;
        prog->aux->dev_bound = !!attr->prog_ifindex;
        prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
        prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;

        err = security_bpf_prog_alloc(prog->aux);
        if (err)
                goto free_prog;

        prog->aux->user = get_current_user();
        prog->len = attr->insn_cnt;

        err = -EFAULT;
        if (copy_from_bpfptr(prog->insns,
                             make_bpfptr(attr->insns, uattr.is_kernel),
                             bpf_prog_insn_size(prog)) != 0)
                goto free_prog_sec;
        /* copy eBPF program license from user space */
        if (strncpy_from_bpfptr(license,
                                make_bpfptr(attr->license, uattr.is_kernel),
                                sizeof(license) - 1) < 0)
                goto free_prog_sec;
        license[sizeof(license) - 1] = 0;

        /* eBPF programs must be GPL compatible to use GPL-ed functions */
        prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;

        prog->orig_prog = NULL;
        prog->jited = 0;

        atomic64_set(&prog->aux->refcnt, 1);

        if (bpf_prog_is_dev_bound(prog->aux)) {
                err = bpf_prog_dev_bound_init(prog, attr);
                if (err)
                        goto free_prog_sec;
        }

        if (type == BPF_PROG_TYPE_EXT && dst_prog &&
            bpf_prog_is_dev_bound(dst_prog->aux)) {
                err = bpf_prog_dev_bound_inherit(prog, dst_prog);
                if (err)
                        goto free_prog_sec;
        }

        /* find program type: socket_filter vs tracing_filter */
        err = find_prog_type(type, prog);
        if (err < 0)
                goto free_prog_sec;

        prog->aux->load_time = ktime_get_boottime_ns();
        err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
                               sizeof(attr->prog_name));
        if (err < 0)
                goto free_prog_sec;

        /* run eBPF verifier */
        err = bpf_check(&prog, attr, uattr, uattr_size);
        if (err < 0)
                goto free_used_maps;

        prog = bpf_prog_select_runtime(prog, &err);
        if (err < 0)
                goto free_used_maps;

        err = bpf_prog_alloc_id(prog);
        if (err)
                goto free_used_maps;

        /* Upon success of bpf_prog_alloc_id(), the BPF prog is
         * effectively publicly exposed. However, retrieving via
         * bpf_prog_get_fd_by_id() will take another reference,
         * therefore it cannot be gone underneath us.
         *
         * Only for the time /after/ successful bpf_prog_new_fd()
         * and before returning to userspace, we might just hold
         * one reference and any parallel close on that fd could
         * rip everything out. Hence, below notifications must
         * happen before bpf_prog_new_fd().
         *
         * Also, any failure handling from this point onwards must
         * be using bpf_prog_put() given the program is exposed.
         */
        bpf_prog_kallsyms_add(prog);
        perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
        bpf_audit_prog(prog, BPF_AUDIT_LOAD);

        err = bpf_prog_new_fd(prog);
        if (err < 0)
                bpf_prog_put(prog);
        return err;

free_used_maps:
        /* In case we have subprogs, we need to wait for a grace
         * period before we can tear down JIT memory since symbols
         * are already exposed under kallsyms.
         */
        __bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
        return err;
free_prog_sec:
        free_uid(prog->aux->user);
        security_bpf_prog_free(prog->aux);
free_prog:
        if (prog->aux->attach_btf)
                btf_put(prog->aux->attach_btf);
        bpf_prog_free(prog);
        return err;
}

#define BPF_OBJ_LAST_FIELD path_fd

static int bpf_obj_pin(const union bpf_attr *attr)
{
        int path_fd;

        if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
                return -EINVAL;

        /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
        if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
                return -EINVAL;

        path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
        return bpf_obj_pin_user(attr->bpf_fd, path_fd,
                                u64_to_user_ptr(attr->pathname));
}

static int bpf_obj_get(const union bpf_attr *attr)
{
        int path_fd;

        if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
            attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
                return -EINVAL;

        /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
        if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
                return -EINVAL;

        path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
        return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
                                attr->file_flags);
}

void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
                   const struct bpf_link_ops *ops, struct bpf_prog *prog)
{
        atomic64_set(&link->refcnt, 1);
        link->type = type;
        link->id = 0;
        link->ops = ops;
        link->prog = prog;
}

static void bpf_link_free_id(int id)
{
        if (!id)
                return;

        spin_lock_bh(&link_idr_lock);
        idr_remove(&link_idr, id);
        spin_unlock_bh(&link_idr_lock);
}

/* Clean up bpf_link and corresponding anon_inode file and FD. After
 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
 * anon_inode's release() call. This helper marks bpf_link as
 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
 * is not decremented, it's the responsibility of a calling code that failed
 * to complete bpf_link initialization.
 * This helper eventually calls link's dealloc callback, but does not call
 * link's release callback.
 */
void bpf_link_cleanup(struct bpf_link_primer *primer)
{
        primer->link->prog = NULL;
        bpf_link_free_id(primer->id);
        fput(primer->file);
        put_unused_fd(primer->fd);
}

void bpf_link_inc(struct bpf_link *link)
{
        atomic64_inc(&link->refcnt);
}

/* bpf_link_free is guaranteed to be called from process context */
static void bpf_link_free(struct bpf_link *link)
{
        bpf_link_free_id(link->id);
        if (link->prog) {
                /* detach BPF program, clean up used resources */
                link->ops->release(link);
                bpf_prog_put(link->prog);
        }
        /* free bpf_link and its containing memory */
        link->ops->dealloc(link);
}

static void bpf_link_put_deferred(struct work_struct *work)
{
        struct bpf_link *link = container_of(work, struct bpf_link, work);

        bpf_link_free(link);
}

/* bpf_link_put might be called from atomic context. It needs to be called
 * from sleepable context in order to acquire sleeping locks during the process.
 */
void bpf_link_put(struct bpf_link *link)
{
        if (!atomic64_dec_and_test(&link->refcnt))
                return;

        INIT_WORK(&link->work, bpf_link_put_deferred);
        schedule_work(&link->work);
}
EXPORT_SYMBOL(bpf_link_put);

static void bpf_link_put_direct(struct bpf_link *link)
{
        if (!atomic64_dec_and_test(&link->refcnt))
                return;
        bpf_link_free(link);
}

static int bpf_link_release(struct inode *inode, struct file *filp)
{
        struct bpf_link *link = filp->private_data;

        bpf_link_put_direct(link);
        return 0;
}

#ifdef CONFIG_PROC_FS
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
#define BPF_MAP_TYPE(_id, _ops)
#define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
static const char *bpf_link_type_strs[] = {
        [BPF_LINK_TYPE_UNSPEC] = "<invalid>",
#include <linux/bpf_types.h>
};
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
#undef BPF_LINK_TYPE

static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
{
        const struct bpf_link *link = filp->private_data;
        const struct bpf_prog *prog = link->prog;
        char prog_tag[sizeof(prog->tag) * 2 + 1] = { };

        seq_printf(m,
                   "link_type:\t%s\n"
                   "link_id:\t%u\n",
                   bpf_link_type_strs[link->type],
                   link->id);
        if (prog) {
                bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
                seq_printf(m,
                           "prog_tag:\t%s\n"
                           "prog_id:\t%u\n",
                           prog_tag,
                           prog->aux->id);
        }
        if (link->ops->show_fdinfo)
                link->ops->show_fdinfo(link, m);
}
#endif

static const struct file_operations bpf_link_fops = {
#ifdef CONFIG_PROC_FS
        .show_fdinfo    = bpf_link_show_fdinfo,
#endif
        .release        = bpf_link_release,
        .read           = bpf_dummy_read,
        .write          = bpf_dummy_write,
};

static int bpf_link_alloc_id(struct bpf_link *link)
{
        int id;

        idr_preload(GFP_KERNEL);
        spin_lock_bh(&link_idr_lock);
        id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
        spin_unlock_bh(&link_idr_lock);
        idr_preload_end();

        return id;
}

/* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
 * reserving unused FD and allocating ID from link_idr. This is to be paired
 * with bpf_link_settle() to install FD and ID and expose bpf_link to
 * user-space, if bpf_link is successfully attached. If not, bpf_link and
 * pre-allocated resources are to be freed with bpf_cleanup() call. All the
 * transient state is passed around in struct bpf_link_primer.
 * This is preferred way to create and initialize bpf_link, especially when
 * there are complicated and expensive operations in between creating bpf_link
 * itself and attaching it to BPF hook. By using bpf_link_prime() and
 * bpf_link_settle() kernel code using bpf_link doesn't have to perform
 * expensive (and potentially failing) roll back operations in a rare case
 * that file, FD, or ID can't be allocated.
 */
int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
{
        struct file *file;
        int fd, id;

        fd = get_unused_fd_flags(O_CLOEXEC);
        if (fd < 0)
                return fd;


        id = bpf_link_alloc_id(link);
        if (id < 0) {
                put_unused_fd(fd);
                return id;
        }

        file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
        if (IS_ERR(file)) {
                bpf_link_free_id(id);
                put_unused_fd(fd);
                return PTR_ERR(file);
        }

        primer->link = link;
        primer->file = file;
        primer->fd = fd;
        primer->id = id;
        return 0;
}

int bpf_link_settle(struct bpf_link_primer *primer)
{
        /* make bpf_link fetchable by ID */
        spin_lock_bh(&link_idr_lock);
        primer->link->id = primer->id;
        spin_unlock_bh(&link_idr_lock);
        /* make bpf_link fetchable by FD */
        fd_install(primer->fd, primer->file);
        /* pass through installed FD */
        return primer->fd;
}

int bpf_link_new_fd(struct bpf_link *link)
{
        return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
}

struct bpf_link *bpf_link_get_from_fd(u32 ufd)
{
        struct fd f = fdget(ufd);
        struct bpf_link *link;

        if (!f.file)
                return ERR_PTR(-EBADF);
        if (f.file->f_op != &bpf_link_fops) {
                fdput(f);
                return ERR_PTR(-EINVAL);
        }

        link = f.file->private_data;
        bpf_link_inc(link);
        fdput(f);

        return link;
}
EXPORT_SYMBOL(bpf_link_get_from_fd);

static void bpf_tracing_link_release(struct bpf_link *link)
{
        struct bpf_tracing_link *tr_link =
                container_of(link, struct bpf_tracing_link, link.link);

        WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
                                                tr_link->trampoline));

        bpf_trampoline_put(tr_link->trampoline);

        /* tgt_prog is NULL if target is a kernel function */
        if (tr_link->tgt_prog)
                bpf_prog_put(tr_link->tgt_prog);
}

static void bpf_tracing_link_dealloc(struct bpf_link *link)
{
        struct bpf_tracing_link *tr_link =
                container_of(link, struct bpf_tracing_link, link.link);

        kfree(tr_link);
}

static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
                                         struct seq_file *seq)
{
        struct bpf_tracing_link *tr_link =
                container_of(link, struct bpf_tracing_link, link.link);
        u32 target_btf_id, target_obj_id;

        bpf_trampoline_unpack_key(tr_link->trampoline->key,
                                  &target_obj_id, &target_btf_id);
        seq_printf(seq,
                   "attach_type:\t%d\n"
                   "target_obj_id:\t%u\n"
                   "target_btf_id:\t%u\n",
                   tr_link->attach_type,
                   target_obj_id,
                   target_btf_id);
}

static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
                                           struct bpf_link_info *info)
{
        struct bpf_tracing_link *tr_link =
                container_of(link, struct bpf_tracing_link, link.link);

        info->tracing.attach_type = tr_link->attach_type;
        bpf_trampoline_unpack_key(tr_link->trampoline->key,
                                  &info->tracing.target_obj_id,
                                  &info->tracing.target_btf_id);

        return 0;
}

static const struct bpf_link_ops bpf_tracing_link_lops = {
        .release = bpf_tracing_link_release,
        .dealloc = bpf_tracing_link_dealloc,
        .show_fdinfo = bpf_tracing_link_show_fdinfo,
        .fill_link_info = bpf_tracing_link_fill_link_info,
};

static int bpf_tracing_prog_attach(struct bpf_prog *prog,
                                   int tgt_prog_fd,
                                   u32 btf_id,
                                   u64 bpf_cookie)
{
        struct bpf_link_primer link_primer;
        struct bpf_prog *tgt_prog = NULL;
        struct bpf_trampoline *tr = NULL;
        struct bpf_tracing_link *link;
        u64 key = 0;
        int err;

        switch (prog->type) {
        case BPF_PROG_TYPE_TRACING:
                if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
                    prog->expected_attach_type != BPF_TRACE_FEXIT &&
                    prog->expected_attach_type != BPF_MODIFY_RETURN) {
                        err = -EINVAL;
                        goto out_put_prog;
                }
                break;
        case BPF_PROG_TYPE_EXT:
                if (prog->expected_attach_type != 0) {
                        err = -EINVAL;
                        goto out_put_prog;
                }
                break;
        case BPF_PROG_TYPE_LSM:
                if (prog->expected_attach_type != BPF_LSM_MAC) {
                        err = -EINVAL;
                        goto out_put_prog;
                }
                break;
        default:
                err = -EINVAL;
                goto out_put_prog;
        }

        if (!!tgt_prog_fd != !!btf_id) {
                err = -EINVAL;
                goto out_put_prog;
        }

        if (tgt_prog_fd) {
                /* For now we only allow new targets for BPF_PROG_TYPE_EXT */
                if (prog->type != BPF_PROG_TYPE_EXT) {
                        err = -EINVAL;
                        goto out_put_prog;
                }

                tgt_prog = bpf_prog_get(tgt_prog_fd);
                if (IS_ERR(tgt_prog)) {
                        err = PTR_ERR(tgt_prog);
                        tgt_prog = NULL;
                        goto out_put_prog;
                }

                key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
        }

        link = kzalloc(sizeof(*link), GFP_USER);
        if (!link) {
                err = -ENOMEM;
                goto out_put_prog;
        }
        bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
                      &bpf_tracing_link_lops, prog);
        link->attach_type = prog->expected_attach_type;
        link->link.cookie = bpf_cookie;

        mutex_lock(&prog->aux->dst_mutex);

        /* There are a few possible cases here:
         *
         * - if prog->aux->dst_trampoline is set, the program was just loaded
         *   and not yet attached to anything, so we can use the values stored
         *   in prog->aux
         *
         * - if prog->aux->dst_trampoline is NULL, the program has already been
         *   attached to a target and its initial target was cleared (below)
         *
         * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
         *   target_btf_id using the link_create API.
         *
         * - if tgt_prog == NULL when this function was called using the old
         *   raw_tracepoint_open API, and we need a target from prog->aux
         *
         * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
         *   was detached and is going for re-attachment.
         */
        if (!prog->aux->dst_trampoline && !tgt_prog) {
                /*
                 * Allow re-attach for TRACING and LSM programs. If it's
                 * currently linked, bpf_trampoline_link_prog will fail.
                 * EXT programs need to specify tgt_prog_fd, so they
                 * re-attach in separate code path.
                 */
                if (prog->type != BPF_PROG_TYPE_TRACING &&
                    prog->type != BPF_PROG_TYPE_LSM) {
                        err = -EINVAL;
                        goto out_unlock;
                }
                btf_id = prog->aux->attach_btf_id;
                key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
        }

        if (!prog->aux->dst_trampoline ||
            (key && key != prog->aux->dst_trampoline->key)) {
                /* If there is no saved target, or the specified target is
                 * different from the destination specified at load time, we
                 * need a new trampoline and a check for compatibility
                 */
                struct bpf_attach_target_info tgt_info = {};

                err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
                                              &tgt_info);
                if (err)
                        goto out_unlock;

                if (tgt_info.tgt_mod) {
                        module_put(prog->aux->mod);
                        prog->aux->mod = tgt_info.tgt_mod;
                }

                tr = bpf_trampoline_get(key, &tgt_info);
                if (!tr) {
                        err = -ENOMEM;
                        goto out_unlock;
                }
        } else {
                /* The caller didn't specify a target, or the target was the
                 * same as the destination supplied during program load. This
                 * means we can reuse the trampoline and reference from program
                 * load time, and there is no need to allocate a new one. This
                 * can only happen once for any program, as the saved values in
                 * prog->aux are cleared below.
                 */
                tr = prog->aux->dst_trampoline;
                tgt_prog = prog->aux->dst_prog;
        }

        err = bpf_link_prime(&link->link.link, &link_primer);
        if (err)
                goto out_unlock;

        err = bpf_trampoline_link_prog(&link->link, tr);
        if (err) {
                bpf_link_cleanup(&link_primer);
                link = NULL;
                goto out_unlock;
        }

        link->tgt_prog = tgt_prog;
        link->trampoline = tr;

        /* Always clear the trampoline and target prog from prog->aux to make
         * sure the original attach destination is not kept alive after a
         * program is (re-)attached to another target.
         */
        if (prog->aux->dst_prog &&
            (tgt_prog_fd || tr != prog->aux->dst_trampoline))
                /* got extra prog ref from syscall, or attaching to different prog */
                bpf_prog_put(prog->aux->dst_prog);
        if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
                /* we allocated a new trampoline, so free the old one */
                bpf_trampoline_put(prog->aux->dst_trampoline);

        prog->aux->dst_prog = NULL;
        prog->aux->dst_trampoline = NULL;
        mutex_unlock(&prog->aux->dst_mutex);

        return bpf_link_settle(&link_primer);
out_unlock:
        if (tr && tr != prog->aux->dst_trampoline)
                bpf_trampoline_put(tr);
        mutex_unlock(&prog->aux->dst_mutex);
        kfree(link);
out_put_prog:
        if (tgt_prog_fd && tgt_prog)
                bpf_prog_put(tgt_prog);
        return err;
}

struct bpf_raw_tp_link {
        struct bpf_link link;
        struct bpf_raw_event_map *btp;
};

static void bpf_raw_tp_link_release(struct bpf_link *link)
{
        struct bpf_raw_tp_link *raw_tp =
                container_of(link, struct bpf_raw_tp_link, link);

        bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
        bpf_put_raw_tracepoint(raw_tp->btp);
}

static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
{
        struct bpf_raw_tp_link *raw_tp =
                container_of(link, struct bpf_raw_tp_link, link);

        kfree(raw_tp);
}

static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
                                        struct seq_file *seq)
{
        struct bpf_raw_tp_link *raw_tp_link =
                container_of(link, struct bpf_raw_tp_link, link);

        seq_printf(seq,
                   "tp_name:\t%s\n",
                   raw_tp_link->btp->tp->name);
}

static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
                            u32 len)
{
        if (ulen >= len + 1) {
                if (copy_to_user(ubuf, buf, len + 1))
                        return -EFAULT;
        } else {
                char zero = '\0';

                if (copy_to_user(ubuf, buf, ulen - 1))
                        return -EFAULT;
                if (put_user(zero, ubuf + ulen - 1))
                        return -EFAULT;
                return -ENOSPC;
        }

        return 0;
}

static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
                                          struct bpf_link_info *info)
{
        struct bpf_raw_tp_link *raw_tp_link =
                container_of(link, struct bpf_raw_tp_link, link);
        char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
        const char *tp_name = raw_tp_link->btp->tp->name;
        u32 ulen = info->raw_tracepoint.tp_name_len;
        size_t tp_len = strlen(tp_name);

        if (!ulen ^ !ubuf)
                return -EINVAL;

        info->raw_tracepoint.tp_name_len = tp_len + 1;

        if (!ubuf)
                return 0;

        return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
}

static const struct bpf_link_ops bpf_raw_tp_link_lops = {
        .release = bpf_raw_tp_link_release,
        .dealloc = bpf_raw_tp_link_dealloc,
        .show_fdinfo = bpf_raw_tp_link_show_fdinfo,
        .fill_link_info = bpf_raw_tp_link_fill_link_info,
};

#ifdef CONFIG_PERF_EVENTS
struct bpf_perf_link {
        struct bpf_link link;
        struct file *perf_file;
};

static void bpf_perf_link_release(struct bpf_link *link)
{
        struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
        struct perf_event *event = perf_link->perf_file->private_data;

        perf_event_free_bpf_prog(event);
        fput(perf_link->perf_file);
}

static void bpf_perf_link_dealloc(struct bpf_link *link)
{
        struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);

        kfree(perf_link);
}

static int bpf_perf_link_fill_common(const struct perf_event *event,
                                     char __user *uname, u32 ulen,
                                     u64 *probe_offset, u64 *probe_addr,
                                     u32 *fd_type, unsigned long *missed)
{
        const char *buf;
        u32 prog_id;
        size_t len;
        int err;

        if (!ulen ^ !uname)
                return -EINVAL;

        err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
                                      probe_offset, probe_addr, missed);
        if (err)
                return err;
        if (!uname)
                return 0;
        if (buf) {
                len = strlen(buf);
                err = bpf_copy_to_user(uname, buf, ulen, len);
                if (err)
                        return err;
        } else {
                char zero = '\0';

                if (put_user(zero, uname))
                        return -EFAULT;
        }
        return 0;
}

#ifdef CONFIG_KPROBE_EVENTS
static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
                                     struct bpf_link_info *info)
{
        unsigned long missed;
        char __user *uname;
        u64 addr, offset;
        u32 ulen, type;
        int err;

        uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
        ulen = info->perf_event.kprobe.name_len;
        err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
                                        &type, &missed);
        if (err)
                return err;
        if (type == BPF_FD_TYPE_KRETPROBE)
                info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
        else
                info->perf_event.type = BPF_PERF_EVENT_KPROBE;

        info->perf_event.kprobe.offset = offset;
        info->perf_event.kprobe.missed = missed;
        if (!kallsyms_show_value(current_cred()))
                addr = 0;
        info->perf_event.kprobe.addr = addr;
        return 0;
}
#endif

#ifdef CONFIG_UPROBE_EVENTS
static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
                                     struct bpf_link_info *info)
{
        char __user *uname;
        u64 addr, offset;
        u32 ulen, type;
        int err;

        uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
        ulen = info->perf_event.uprobe.name_len;
        err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
                                        &type, NULL);
        if (err)
                return err;

        if (type == BPF_FD_TYPE_URETPROBE)
                info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
        else
                info->perf_event.type = BPF_PERF_EVENT_UPROBE;
        info->perf_event.uprobe.offset = offset;
        return 0;
}
#endif

static int bpf_perf_link_fill_probe(const struct perf_event *event,
                                    struct bpf_link_info *info)
{
#ifdef CONFIG_KPROBE_EVENTS
        if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
                return bpf_perf_link_fill_kprobe(event, info);
#endif
#ifdef CONFIG_UPROBE_EVENTS
        if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
                return bpf_perf_link_fill_uprobe(event, info);
#endif
        return -EOPNOTSUPP;
}

static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
                                         struct bpf_link_info *info)
{
        char __user *uname;
        u32 ulen;

        uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
        ulen = info->perf_event.tracepoint.name_len;
        info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
        return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL);
}

static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
                                         struct bpf_link_info *info)
{
        info->perf_event.event.type = event->attr.type;
        info->perf_event.event.config = event->attr.config;
        info->perf_event.type = BPF_PERF_EVENT_EVENT;
        return 0;
}

static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
                                        struct bpf_link_info *info)
{
        struct bpf_perf_link *perf_link;
        const struct perf_event *event;

        perf_link = container_of(link, struct bpf_perf_link, link);
        event = perf_get_event(perf_link->perf_file);
        if (IS_ERR(event))
                return PTR_ERR(event);

        switch (event->prog->type) {
        case BPF_PROG_TYPE_PERF_EVENT:
                return bpf_perf_link_fill_perf_event(event, info);
        case BPF_PROG_TYPE_TRACEPOINT:
                return bpf_perf_link_fill_tracepoint(event, info);
        case BPF_PROG_TYPE_KPROBE:
                return bpf_perf_link_fill_probe(event, info);
        default:
                return -EOPNOTSUPP;
        }
}

static const struct bpf_link_ops bpf_perf_link_lops = {
        .release = bpf_perf_link_release,
        .dealloc = bpf_perf_link_dealloc,
        .fill_link_info = bpf_perf_link_fill_link_info,
};

static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
        struct bpf_link_primer link_primer;
        struct bpf_perf_link *link;
        struct perf_event *event;
        struct file *perf_file;
        int err;

        if (attr->link_create.flags)
                return -EINVAL;

        perf_file = perf_event_get(attr->link_create.target_fd);
        if (IS_ERR(perf_file))
                return PTR_ERR(perf_file);

        link = kzalloc(sizeof(*link), GFP_USER);
        if (!link) {
                err = -ENOMEM;
                goto out_put_file;
        }
        bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
        link->perf_file = perf_file;

        err = bpf_link_prime(&link->link, &link_primer);
        if (err) {
                kfree(link);
                goto out_put_file;
        }

        event = perf_file->private_data;
        err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
        if (err) {
                bpf_link_cleanup(&link_primer);
                goto out_put_file;
        }
        /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
        bpf_prog_inc(prog);

        return bpf_link_settle(&link_primer);

out_put_file:
        fput(perf_file);
        return err;
}
#else
static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
        return -EOPNOTSUPP;
}
#endif /* CONFIG_PERF_EVENTS */

static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
                                  const char __user *user_tp_name)
{
        struct bpf_link_primer link_primer;
        struct bpf_raw_tp_link *link;
        struct bpf_raw_event_map *btp;
        const char *tp_name;
        char buf[128];
        int err;

        switch (prog->type) {
        case BPF_PROG_TYPE_TRACING:
        case BPF_PROG_TYPE_EXT:
        case BPF_PROG_TYPE_LSM:
                if (user_tp_name)
                        /* The attach point for this category of programs
                         * should be specified via btf_id during program load.
                         */
                        return -EINVAL;
                if (prog->type == BPF_PROG_TYPE_TRACING &&
                    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
                        tp_name = prog->aux->attach_func_name;
                        break;
                }
                return bpf_tracing_prog_attach(prog, 0, 0, 0);
        case BPF_PROG_TYPE_RAW_TRACEPOINT:
        case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
                if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
                        return -EFAULT;
                buf[sizeof(buf) - 1] = 0;
                tp_name = buf;
                break;
        default:
                return -EINVAL;
        }

        btp = bpf_get_raw_tracepoint(tp_name);
        if (!btp)
                return -ENOENT;

        link = kzalloc(sizeof(*link), GFP_USER);
        if (!link) {
                err = -ENOMEM;
                goto out_put_btp;
        }
        bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
                      &bpf_raw_tp_link_lops, prog);
        link->btp = btp;

        err = bpf_link_prime(&link->link, &link_primer);
        if (err) {
                kfree(link);
                goto out_put_btp;
        }

        err = bpf_probe_register(link->btp, prog);
        if (err) {
                bpf_link_cleanup(&link_primer);
                goto out_put_btp;
        }

        return bpf_link_settle(&link_primer);

out_put_btp:
        bpf_put_raw_tracepoint(btp);
        return err;
}

#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd

static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
{
        struct bpf_prog *prog;
        int fd;

        if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
                return -EINVAL;

        prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
        if (IS_ERR(prog))
                return PTR_ERR(prog);

        fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name));
        if (fd < 0)
                bpf_prog_put(prog);
        return fd;
}

static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)
{
        switch (attach_type) {
        case BPF_CGROUP_INET_INGRESS:
        case BPF_CGROUP_INET_EGRESS:
                return BPF_PROG_TYPE_CGROUP_SKB;
        case BPF_CGROUP_INET_SOCK_CREATE:
        case BPF_CGROUP_INET_SOCK_RELEASE:
        case BPF_CGROUP_INET4_POST_BIND:
        case BPF_CGROUP_INET6_POST_BIND:
                return BPF_PROG_TYPE_CGROUP_SOCK;
        case BPF_CGROUP_INET4_BIND:
        case BPF_CGROUP_INET6_BIND:
        case BPF_CGROUP_INET4_CONNECT:
        case BPF_CGROUP_INET6_CONNECT:
        case BPF_CGROUP_UNIX_CONNECT:
        case BPF_CGROUP_INET4_GETPEERNAME:
        case BPF_CGROUP_INET6_GETPEERNAME:
        case BPF_CGROUP_UNIX_GETPEERNAME:
        case BPF_CGROUP_INET4_GETSOCKNAME:
        case BPF_CGROUP_INET6_GETSOCKNAME:
        case BPF_CGROUP_UNIX_GETSOCKNAME:
        case BPF_CGROUP_UDP4_SENDMSG:
        case BPF_CGROUP_UDP6_SENDMSG:
        case BPF_CGROUP_UNIX_SENDMSG:
        case BPF_CGROUP_UDP4_RECVMSG:
        case BPF_CGROUP_UDP6_RECVMSG:
        case BPF_CGROUP_UNIX_RECVMSG:
                return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
        case BPF_CGROUP_SOCK_OPS:
                return BPF_PROG_TYPE_SOCK_OPS;
        case BPF_CGROUP_DEVICE:
                return BPF_PROG_TYPE_CGROUP_DEVICE;
        case BPF_SK_MSG_VERDICT:
                return BPF_PROG_TYPE_SK_MSG;
        case BPF_SK_SKB_STREAM_PARSER:
        case BPF_SK_SKB_STREAM_VERDICT:
        case BPF_SK_SKB_VERDICT:
                return BPF_PROG_TYPE_SK_SKB;
        case BPF_LIRC_MODE2:
                return BPF_PROG_TYPE_LIRC_MODE2;
        case BPF_FLOW_DISSECTOR:
                return BPF_PROG_TYPE_FLOW_DISSECTOR;
        case BPF_CGROUP_SYSCTL:
                return BPF_PROG_TYPE_CGROUP_SYSCTL;
        case BPF_CGROUP_GETSOCKOPT:
        case BPF_CGROUP_SETSOCKOPT:
                return BPF_PROG_TYPE_CGROUP_SOCKOPT;
        case BPF_TRACE_ITER:
        case BPF_TRACE_RAW_TP:
        case BPF_TRACE_FENTRY:
        case BPF_TRACE_FEXIT:
        case BPF_MODIFY_RETURN:
                return BPF_PROG_TYPE_TRACING;
        case BPF_LSM_MAC:
                return BPF_PROG_TYPE_LSM;
        case BPF_SK_LOOKUP:
                return BPF_PROG_TYPE_SK_LOOKUP;
        case BPF_XDP:
                return BPF_PROG_TYPE_XDP;
        case BPF_LSM_CGROUP:
                return BPF_PROG_TYPE_LSM;
        case BPF_TCX_INGRESS:
        case BPF_TCX_EGRESS:
        case BPF_NETKIT_PRIMARY:
        case BPF_NETKIT_PEER:
                return BPF_PROG_TYPE_SCHED_CLS;
        default:
                return BPF_PROG_TYPE_UNSPEC;
        }
}

static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
                                             enum bpf_attach_type attach_type)
{
        enum bpf_prog_type ptype;

        switch (prog->type) {
        case BPF_PROG_TYPE_CGROUP_SOCK:
        case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
        case BPF_PROG_TYPE_CGROUP_SOCKOPT:
        case BPF_PROG_TYPE_SK_LOOKUP:
                return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
        case BPF_PROG_TYPE_CGROUP_SKB:
                if (!capable(CAP_NET_ADMIN))
                        /* cg-skb progs can be loaded by unpriv user.
                         * check permissions at attach time.
                         */
                        return -EPERM;
                return prog->enforce_expected_attach_type &&
                        prog->expected_attach_type != attach_type ?
                        -EINVAL : 0;
        case BPF_PROG_TYPE_EXT:
                return 0;
        case BPF_PROG_TYPE_NETFILTER:
                if (attach_type != BPF_NETFILTER)
                        return -EINVAL;
                return 0;
        case BPF_PROG_TYPE_PERF_EVENT:
        case BPF_PROG_TYPE_TRACEPOINT:
                if (attach_type != BPF_PERF_EVENT)
                        return -EINVAL;
                return 0;
        case BPF_PROG_TYPE_KPROBE:
                if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
                    attach_type != BPF_TRACE_KPROBE_MULTI)
                        return -EINVAL;
                if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
                    attach_type != BPF_TRACE_UPROBE_MULTI)
                        return -EINVAL;
                if (attach_type != BPF_PERF_EVENT &&
                    attach_type != BPF_TRACE_KPROBE_MULTI &&
                    attach_type != BPF_TRACE_UPROBE_MULTI)
                        return -EINVAL;
                return 0;
        case BPF_PROG_TYPE_SCHED_CLS:
                if (attach_type != BPF_TCX_INGRESS &&
                    attach_type != BPF_TCX_EGRESS &&
                    attach_type != BPF_NETKIT_PRIMARY &&
                    attach_type != BPF_NETKIT_PEER)
                        return -EINVAL;
                return 0;
        default:
                ptype = attach_type_to_prog_type(attach_type);
                if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
                        return -EINVAL;
                return 0;
        }
}

#define BPF_PROG_ATTACH_LAST_FIELD expected_revision

#define BPF_F_ATTACH_MASK_BASE  \
        (BPF_F_ALLOW_OVERRIDE | \
         BPF_F_ALLOW_MULTI |    \
         BPF_F_REPLACE)

#define BPF_F_ATTACH_MASK_MPROG \
        (BPF_F_REPLACE |        \
         BPF_F_BEFORE |         \
         BPF_F_AFTER |          \
         BPF_F_ID |             \
         BPF_F_LINK)

static int bpf_prog_attach(const union bpf_attr *attr)
{
        enum bpf_prog_type ptype;
        struct bpf_prog *prog;
        int ret;

        if (CHECK_ATTR(BPF_PROG_ATTACH))
                return -EINVAL;

        ptype = attach_type_to_prog_type(attr->attach_type);
        if (ptype == BPF_PROG_TYPE_UNSPEC)
                return -EINVAL;
        if (bpf_mprog_supported(ptype)) {
                if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
                        return -EINVAL;
        } else {
                if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
                        return -EINVAL;
                if (attr->relative_fd ||
                    attr->expected_revision)
                        return -EINVAL;
        }

        prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
        if (IS_ERR(prog))
                return PTR_ERR(prog);

        if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
                bpf_prog_put(prog);
                return -EINVAL;
        }

        switch (ptype) {
        case BPF_PROG_TYPE_SK_SKB:
        case BPF_PROG_TYPE_SK_MSG:
                ret = sock_map_get_from_fd(attr, prog);
                break;
        case BPF_PROG_TYPE_LIRC_MODE2:
                ret = lirc_prog_attach(attr, prog);
                break;
        case BPF_PROG_TYPE_FLOW_DISSECTOR:
                ret = netns_bpf_prog_attach(attr, prog);
                break;
        case BPF_PROG_TYPE_CGROUP_DEVICE:
        case BPF_PROG_TYPE_CGROUP_SKB:
        case BPF_PROG_TYPE_CGROUP_SOCK:
        case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
        case BPF_PROG_TYPE_CGROUP_SOCKOPT:
        case BPF_PROG_TYPE_CGROUP_SYSCTL:
        case BPF_PROG_TYPE_SOCK_OPS:
        case BPF_PROG_TYPE_LSM:
                if (ptype == BPF_PROG_TYPE_LSM &&
                    prog->expected_attach_type != BPF_LSM_CGROUP)
                        ret = -EINVAL;
                else
                        ret = cgroup_bpf_prog_attach(attr, ptype, prog);
                break;
        case BPF_PROG_TYPE_SCHED_CLS:
                if (attr->attach_type == BPF_TCX_INGRESS ||
                    attr->attach_type == BPF_TCX_EGRESS)
                        ret = tcx_prog_attach(attr, prog);
                else
                        ret = netkit_prog_attach(attr, prog);
                break;
        default:
                ret = -EINVAL;
        }

        if (ret)
                bpf_prog_put(prog);
        return ret;
}

#define BPF_PROG_DETACH_LAST_FIELD expected_revision

static int bpf_prog_detach(const union bpf_attr *attr)
{
        struct bpf_prog *prog = NULL;
        enum bpf_prog_type ptype;
        int ret;

        if (CHECK_ATTR(BPF_PROG_DETACH))
                return -EINVAL;

        ptype = attach_type_to_prog_type(attr->attach_type);
        if (bpf_mprog_supported(ptype)) {
                if (ptype == BPF_PROG_TYPE_UNSPEC)
                        return -EINVAL;
                if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
                        return -EINVAL;
                if (attr->attach_bpf_fd) {
                        prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
                        if (IS_ERR(prog))
                                return PTR_ERR(prog);
                }
        } else if (attr->attach_flags ||
                   attr->relative_fd ||
                   attr->expected_revision) {
                return -EINVAL;
        }

        switch (ptype) {
        case BPF_PROG_TYPE_SK_MSG:
        case BPF_PROG_TYPE_SK_SKB:
                ret = sock_map_prog_detach(attr, ptype);
                break;
        case BPF_PROG_TYPE_LIRC_MODE2:
                ret = lirc_prog_detach(attr);
                break;
        case BPF_PROG_TYPE_FLOW_DISSECTOR:
                ret = netns_bpf_prog_detach(attr, ptype);
                break;
        case BPF_PROG_TYPE_CGROUP_DEVICE:
        case BPF_PROG_TYPE_CGROUP_SKB:
        case BPF_PROG_TYPE_CGROUP_SOCK:
        case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
        case BPF_PROG_TYPE_CGROUP_SOCKOPT:
        case BPF_PROG_TYPE_CGROUP_SYSCTL:
        case BPF_PROG_TYPE_SOCK_OPS:
        case BPF_PROG_TYPE_LSM:
                ret = cgroup_bpf_prog_detach(attr, ptype);
                break;
        case BPF_PROG_TYPE_SCHED_CLS:
                if (attr->attach_type == BPF_TCX_INGRESS ||
                    attr->attach_type == BPF_TCX_EGRESS)
                        ret = tcx_prog_detach(attr, prog);
                else
                        ret = netkit_prog_detach(attr, prog);
                break;
        default:
                ret = -EINVAL;
        }

        if (prog)
                bpf_prog_put(prog);
        return ret;
}

#define BPF_PROG_QUERY_LAST_FIELD query.revision

static int bpf_prog_query(const union bpf_attr *attr,
                          union bpf_attr __user *uattr)
{
        if (!capable(CAP_NET_ADMIN))
                return -EPERM;
        if (CHECK_ATTR(BPF_PROG_QUERY))
                return -EINVAL;
        if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
                return -EINVAL;

        switch (attr->query.attach_type) {
        case BPF_CGROUP_INET_INGRESS:
        case BPF_CGROUP_INET_EGRESS:
        case BPF_CGROUP_INET_SOCK_CREATE:
        case BPF_CGROUP_INET_SOCK_RELEASE:
        case BPF_CGROUP_INET4_BIND:
        case BPF_CGROUP_INET6_BIND:
        case BPF_CGROUP_INET4_POST_BIND:
        case BPF_CGROUP_INET6_POST_BIND:
        case BPF_CGROUP_INET4_CONNECT:
        case BPF_CGROUP_INET6_CONNECT:
        case BPF_CGROUP_UNIX_CONNECT:
        case BPF_CGROUP_INET4_GETPEERNAME:
        case BPF_CGROUP_INET6_GETPEERNAME:
        case BPF_CGROUP_UNIX_GETPEERNAME:
        case BPF_CGROUP_INET4_GETSOCKNAME:
        case BPF_CGROUP_INET6_GETSOCKNAME:
        case BPF_CGROUP_UNIX_GETSOCKNAME:
        case BPF_CGROUP_UDP4_SENDMSG:
        case BPF_CGROUP_UDP6_SENDMSG:
        case BPF_CGROUP_UNIX_SENDMSG:
        case BPF_CGROUP_UDP4_RECVMSG:
        case BPF_CGROUP_UDP6_RECVMSG:
        case BPF_CGROUP_UNIX_RECVMSG:
        case BPF_CGROUP_SOCK_OPS:
        case BPF_CGROUP_DEVICE:
        case BPF_CGROUP_SYSCTL:
        case BPF_CGROUP_GETSOCKOPT:
        case BPF_CGROUP_SETSOCKOPT:
        case BPF_LSM_CGROUP:
                return cgroup_bpf_prog_query(attr, uattr);
        case BPF_LIRC_MODE2:
                return lirc_prog_query(attr, uattr);
        case BPF_FLOW_DISSECTOR:
        case BPF_SK_LOOKUP:
                return netns_bpf_prog_query(attr, uattr);
        case BPF_SK_SKB_STREAM_PARSER:
        case BPF_SK_SKB_STREAM_VERDICT:
        case BPF_SK_MSG_VERDICT:
        case BPF_SK_SKB_VERDICT:
                return sock_map_bpf_prog_query(attr, uattr);
        case BPF_TCX_INGRESS:
        case BPF_TCX_EGRESS:
                return tcx_prog_query(attr, uattr);
        case BPF_NETKIT_PRIMARY:
        case BPF_NETKIT_PEER:
                return netkit_prog_query(attr, uattr);
        default:
                return -EINVAL;
        }
}

#define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size

static int bpf_prog_test_run(const union bpf_attr *attr,
                             union bpf_attr __user *uattr)
{
        struct bpf_prog *prog;
        int ret = -ENOTSUPP;

        if (CHECK_ATTR(BPF_PROG_TEST_RUN))
                return -EINVAL;

        if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
            (!attr->test.ctx_size_in && attr->test.ctx_in))
                return -EINVAL;

        if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
            (!attr->test.ctx_size_out && attr->test.ctx_out))
                return -EINVAL;

        prog = bpf_prog_get(attr->test.prog_fd);
        if (IS_ERR(prog))
                return PTR_ERR(prog);

        if (prog->aux->ops->test_run)
                ret = prog->aux->ops->test_run(prog, attr, uattr);

        bpf_prog_put(prog);
        return ret;
}

#define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id

static int bpf_obj_get_next_id(const union bpf_attr *attr,
                               union bpf_attr __user *uattr,
                               struct idr *idr,
                               spinlock_t *lock)
{
        u32 next_id = attr->start_id;
        int err = 0;

        if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
                return -EINVAL;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        next_id++;
        spin_lock_bh(lock);
        if (!idr_get_next(idr, &next_id))
                err = -ENOENT;
        spin_unlock_bh(lock);

        if (!err)
                err = put_user(next_id, &uattr->next_id);

        return err;
}

struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
{
        struct bpf_map *map;

        spin_lock_bh(&map_idr_lock);
again:
        map = idr_get_next(&map_idr, id);
        if (map) {
                map = __bpf_map_inc_not_zero(map, false);
                if (IS_ERR(map)) {
                        (*id)++;
                        goto again;
                }
        }
        spin_unlock_bh(&map_idr_lock);

        return map;
}

struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
{
        struct bpf_prog *prog;

        spin_lock_bh(&prog_idr_lock);
again:
        prog = idr_get_next(&prog_idr, id);
        if (prog) {
                prog = bpf_prog_inc_not_zero(prog);
                if (IS_ERR(prog)) {
                        (*id)++;
                        goto again;
                }
        }
        spin_unlock_bh(&prog_idr_lock);

        return prog;
}

#define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id

struct bpf_prog *bpf_prog_by_id(u32 id)
{
        struct bpf_prog *prog;

        if (!id)
                return ERR_PTR(-ENOENT);

        spin_lock_bh(&prog_idr_lock);
        prog = idr_find(&prog_idr, id);
        if (prog)
                prog = bpf_prog_inc_not_zero(prog);
        else
                prog = ERR_PTR(-ENOENT);
        spin_unlock_bh(&prog_idr_lock);
        return prog;
}

static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
{
        struct bpf_prog *prog;
        u32 id = attr->prog_id;
        int fd;

        if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
                return -EINVAL;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        prog = bpf_prog_by_id(id);
        if (IS_ERR(prog))
                return PTR_ERR(prog);

        fd = bpf_prog_new_fd(prog);
        if (fd < 0)
                bpf_prog_put(prog);

        return fd;
}

#define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags

static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
{
        struct bpf_map *map;
        u32 id = attr->map_id;
        int f_flags;
        int fd;

        if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
            attr->open_flags & ~BPF_OBJ_FLAG_MASK)
                return -EINVAL;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        f_flags = bpf_get_file_flag(attr->open_flags);
        if (f_flags < 0)
                return f_flags;

        spin_lock_bh(&map_idr_lock);
        map = idr_find(&map_idr, id);
        if (map)
                map = __bpf_map_inc_not_zero(map, true);
        else
                map = ERR_PTR(-ENOENT);
        spin_unlock_bh(&map_idr_lock);

        if (IS_ERR(map))
                return PTR_ERR(map);

        fd = bpf_map_new_fd(map, f_flags);
        if (fd < 0)
                bpf_map_put_with_uref(map);

        return fd;
}

static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
                                              unsigned long addr, u32 *off,
                                              u32 *type)
{
        const struct bpf_map *map;
        int i;

        mutex_lock(&prog->aux->used_maps_mutex);
        for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
                map = prog->aux->used_maps[i];
                if (map == (void *)addr) {
                        *type = BPF_PSEUDO_MAP_FD;
                        goto out;
                }
                if (!map->ops->map_direct_value_meta)
                        continue;
                if (!map->ops->map_direct_value_meta(map, addr, off)) {
                        *type = BPF_PSEUDO_MAP_VALUE;
                        goto out;
                }
        }
        map = NULL;

out:
        mutex_unlock(&prog->aux->used_maps_mutex);
        return map;
}

static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
                                              const struct cred *f_cred)
{
        const struct bpf_map *map;
        struct bpf_insn *insns;
        u32 off, type;
        u64 imm;
        u8 code;
        int i;

        insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
                        GFP_USER);
        if (!insns)
                return insns;

        for (i = 0; i < prog->len; i++) {
                code = insns[i].code;

                if (code == (BPF_JMP | BPF_TAIL_CALL)) {
                        insns[i].code = BPF_JMP | BPF_CALL;
                        insns[i].imm = BPF_FUNC_tail_call;
                        /* fall-through */
                }
                if (code == (BPF_JMP | BPF_CALL) ||
                    code == (BPF_JMP | BPF_CALL_ARGS)) {
                        if (code == (BPF_JMP | BPF_CALL_ARGS))
                                insns[i].code = BPF_JMP | BPF_CALL;
                        if (!bpf_dump_raw_ok(f_cred))
                                insns[i].imm = 0;
                        continue;
                }
                if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
                        insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
                        continue;
                }

                if (code != (BPF_LD | BPF_IMM | BPF_DW))
                        continue;

                imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
                map = bpf_map_from_imm(prog, imm, &off, &type);
                if (map) {
                        insns[i].src_reg = type;
                        insns[i].imm = map->id;
                        insns[i + 1].imm = off;
                        continue;
                }
        }

        return insns;
}

static int set_info_rec_size(struct bpf_prog_info *info)
{
        /*
         * Ensure info.*_rec_size is the same as kernel expected size
         *
         * or
         *
         * Only allow zero *_rec_size if both _rec_size and _cnt are
         * zero.  In this case, the kernel will set the expected
         * _rec_size back to the info.
         */

        if ((info->nr_func_info || info->func_info_rec_size) &&
            info->func_info_rec_size != sizeof(struct bpf_func_info))
                return -EINVAL;

        if ((info->nr_line_info || info->line_info_rec_size) &&
            info->line_info_rec_size != sizeof(struct bpf_line_info))
                return -EINVAL;

        if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
            info->jited_line_info_rec_size != sizeof(__u64))
                return -EINVAL;

        info->func_info_rec_size = sizeof(struct bpf_func_info);
        info->line_info_rec_size = sizeof(struct bpf_line_info);
        info->jited_line_info_rec_size = sizeof(__u64);

        return 0;
}

static int bpf_prog_get_info_by_fd(struct file *file,
                                   struct bpf_prog *prog,
                                   const union bpf_attr *attr,
                                   union bpf_attr __user *uattr)
{
        struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
        struct btf *attach_btf = bpf_prog_get_target_btf(prog);
        struct bpf_prog_info info;
        u32 info_len = attr->info.info_len;
        struct bpf_prog_kstats stats;
        char __user *uinsns;
        u32 ulen;
        int err;

        err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
        if (err)
                return err;
        info_len = min_t(u32, sizeof(info), info_len);

        memset(&info, 0, sizeof(info));
        if (copy_from_user(&info, uinfo, info_len))
                return -EFAULT;

        info.type = prog->type;
        info.id = prog->aux->id;
        info.load_time = prog->aux->load_time;
        info.created_by_uid = from_kuid_munged(current_user_ns(),
                                               prog->aux->user->uid);
        info.gpl_compatible = prog->gpl_compatible;

        memcpy(info.tag, prog->tag, sizeof(prog->tag));
        memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));

        mutex_lock(&prog->aux->used_maps_mutex);
        ulen = info.nr_map_ids;
        info.nr_map_ids = prog->aux->used_map_cnt;
        ulen = min_t(u32, info.nr_map_ids, ulen);
        if (ulen) {
                u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
                u32 i;

                for (i = 0; i < ulen; i++)
                        if (put_user(prog->aux->used_maps[i]->id,
                                     &user_map_ids[i])) {
                                mutex_unlock(&prog->aux->used_maps_mutex);
                                return -EFAULT;
                        }
        }
        mutex_unlock(&prog->aux->used_maps_mutex);

        err = set_info_rec_size(&info);
        if (err)
                return err;

        bpf_prog_get_stats(prog, &stats);
        info.run_time_ns = stats.nsecs;
        info.run_cnt = stats.cnt;
        info.recursion_misses = stats.misses;

        info.verified_insns = prog->aux->verified_insns;

        if (!bpf_capable()) {
                info.jited_prog_len = 0;
                info.xlated_prog_len = 0;
                info.nr_jited_ksyms = 0;
                info.nr_jited_func_lens = 0;
                info.nr_func_info = 0;
                info.nr_line_info = 0;
                info.nr_jited_line_info = 0;
                goto done;
        }

        ulen = info.xlated_prog_len;
        info.xlated_prog_len = bpf_prog_insn_size(prog);
        if (info.xlated_prog_len && ulen) {
                struct bpf_insn *insns_sanitized;
                bool fault;

                if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
                        info.xlated_prog_insns = 0;
                        goto done;
                }
                insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
                if (!insns_sanitized)
                        return -ENOMEM;
                uinsns = u64_to_user_ptr(info.xlated_prog_insns);
                ulen = min_t(u32, info.xlated_prog_len, ulen);
                fault = copy_to_user(uinsns, insns_sanitized, ulen);
                kfree(insns_sanitized);
                if (fault)
                        return -EFAULT;
        }

        if (bpf_prog_is_offloaded(prog->aux)) {
                err = bpf_prog_offload_info_fill(&info, prog);
                if (err)
                        return err;
                goto done;
        }

        /* NOTE: the following code is supposed to be skipped for offload.
         * bpf_prog_offload_info_fill() is the place to fill similar fields
         * for offload.
         */
        ulen = info.jited_prog_len;
        if (prog->aux->func_cnt) {
                u32 i;

                info.jited_prog_len = 0;
                for (i = 0; i < prog->aux->func_cnt; i++)
                        info.jited_prog_len += prog->aux->func[i]->jited_len;
        } else {
                info.jited_prog_len = prog->jited_len;
        }

        if (info.jited_prog_len && ulen) {
                if (bpf_dump_raw_ok(file->f_cred)) {
                        uinsns = u64_to_user_ptr(info.jited_prog_insns);
                        ulen = min_t(u32, info.jited_prog_len, ulen);

                        /* for multi-function programs, copy the JITed
                         * instructions for all the functions
                         */
                        if (prog->aux->func_cnt) {
                                u32 len, free, i;
                                u8 *img;

                                free = ulen;
                                for (i = 0; i < prog->aux->func_cnt; i++) {
                                        len = prog->aux->func[i]->jited_len;
                                        len = min_t(u32, len, free);
                                        img = (u8 *) prog->aux->func[i]->bpf_func;
                                        if (copy_to_user(uinsns, img, len))
                                                return -EFAULT;
                                        uinsns += len;
                                        free -= len;
                                        if (!free)
                                                break;
                                }
                        } else {
                                if (copy_to_user(uinsns, prog->bpf_func, ulen))
                                        return -EFAULT;
                        }
                } else {
                        info.jited_prog_insns = 0;
                }
        }

        ulen = info.nr_jited_ksyms;
        info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
        if (ulen) {
                if (bpf_dump_raw_ok(file->f_cred)) {
                        unsigned long ksym_addr;
                        u64 __user *user_ksyms;
                        u32 i;

                        /* copy the address of the kernel symbol
                         * corresponding to each function
                         */
                        ulen = min_t(u32, info.nr_jited_ksyms, ulen);
                        user_ksyms = u64_to_user_ptr(info.jited_ksyms);
                        if (prog->aux->func_cnt) {
                                for (i = 0; i < ulen; i++) {
                                        ksym_addr = (unsigned long)
                                                prog->aux->func[i]->bpf_func;
                                        if (put_user((u64) ksym_addr,
                                                     &user_ksyms[i]))
                                                return -EFAULT;
                                }
                        } else {
                                ksym_addr = (unsigned long) prog->bpf_func;
                                if (put_user((u64) ksym_addr, &user_ksyms[0]))
                                        return -EFAULT;
                        }
                } else {
                        info.jited_ksyms = 0;
                }
        }

        ulen = info.nr_jited_func_lens;
        info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
        if (ulen) {
                if (bpf_dump_raw_ok(file->f_cred)) {
                        u32 __user *user_lens;
                        u32 func_len, i;

                        /* copy the JITed image lengths for each function */
                        ulen = min_t(u32, info.nr_jited_func_lens, ulen);
                        user_lens = u64_to_user_ptr(info.jited_func_lens);
                        if (prog->aux->func_cnt) {
                                for (i = 0; i < ulen; i++) {
                                        func_len =
                                                prog->aux->func[i]->jited_len;
                                        if (put_user(func_len, &user_lens[i]))
                                                return -EFAULT;
                                }
                        } else {
                                func_len = prog->jited_len;
                                if (put_user(func_len, &user_lens[0]))
                                        return -EFAULT;
                        }
                } else {
                        info.jited_func_lens = 0;
                }
        }

        if (prog->aux->btf)
                info.btf_id = btf_obj_id(prog->aux->btf);
        info.attach_btf_id = prog->aux->attach_btf_id;
        if (attach_btf)
                info.attach_btf_obj_id = btf_obj_id(attach_btf);

        ulen = info.nr_func_info;
        info.nr_func_info = prog->aux->func_info_cnt;
        if (info.nr_func_info && ulen) {
                char __user *user_finfo;

                user_finfo = u64_to_user_ptr(info.func_info);
                ulen = min_t(u32, info.nr_func_info, ulen);
                if (copy_to_user(user_finfo, prog->aux->func_info,
                                 info.func_info_rec_size * ulen))
                        return -EFAULT;
        }

        ulen = info.nr_line_info;
        info.nr_line_info = prog->aux->nr_linfo;
        if (info.nr_line_info && ulen) {
                __u8 __user *user_linfo;

                user_linfo = u64_to_user_ptr(info.line_info);
                ulen = min_t(u32, info.nr_line_info, ulen);
                if (copy_to_user(user_linfo, prog->aux->linfo,
                                 info.line_info_rec_size * ulen))
                        return -EFAULT;
        }

        ulen = info.nr_jited_line_info;
        if (prog->aux->jited_linfo)
                info.nr_jited_line_info = prog->aux->nr_linfo;
        else
                info.nr_jited_line_info = 0;
        if (info.nr_jited_line_info && ulen) {
                if (bpf_dump_raw_ok(file->f_cred)) {
                        unsigned long line_addr;
                        __u64 __user *user_linfo;
                        u32 i;

                        user_linfo = u64_to_user_ptr(info.jited_line_info);
                        ulen = min_t(u32, info.nr_jited_line_info, ulen);
                        for (i = 0; i < ulen; i++) {
                                line_addr = (unsigned long)prog->aux->jited_linfo[i];
                                if (put_user((__u64)line_addr, &user_linfo[i]))
                                        return -EFAULT;
                        }
                } else {
                        info.jited_line_info = 0;
                }
        }

        ulen = info.nr_prog_tags;
        info.nr_prog_tags = prog->aux->func_cnt ? : 1;
        if (ulen) {
                __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
                u32 i;

                user_prog_tags = u64_to_user_ptr(info.prog_tags);
                ulen = min_t(u32, info.nr_prog_tags, ulen);
                if (prog->aux->func_cnt) {
                        for (i = 0; i < ulen; i++) {
                                if (copy_to_user(user_prog_tags[i],
                                                 prog->aux->func[i]->tag,
                                                 BPF_TAG_SIZE))
                                        return -EFAULT;
                        }
                } else {
                        if (copy_to_user(user_prog_tags[0],
                                         prog->tag, BPF_TAG_SIZE))
                                return -EFAULT;
                }
        }

done:
        if (copy_to_user(uinfo, &info, info_len) ||
            put_user(info_len, &uattr->info.info_len))
                return -EFAULT;

        return 0;
}

static int bpf_map_get_info_by_fd(struct file *file,
                                  struct bpf_map *map,
                                  const union bpf_attr *attr,
                                  union bpf_attr __user *uattr)
{
        struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
        struct bpf_map_info info;
        u32 info_len = attr->info.info_len;
        int err;

        err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
        if (err)
                return err;
        info_len = min_t(u32, sizeof(info), info_len);

        memset(&info, 0, sizeof(info));
        info.type = map->map_type;
        info.id = map->id;
        info.key_size = map->key_size;
        info.value_size = map->value_size;
        info.max_entries = map->max_entries;
        info.map_flags = map->map_flags;
        info.map_extra = map->map_extra;
        memcpy(info.name, map->name, sizeof(map->name));

        if (map->btf) {
                info.btf_id = btf_obj_id(map->btf);
                info.btf_key_type_id = map->btf_key_type_id;
                info.btf_value_type_id = map->btf_value_type_id;
        }
        info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;

        if (bpf_map_is_offloaded(map)) {
                err = bpf_map_offload_info_fill(&info, map);
                if (err)
                        return err;
        }

        if (copy_to_user(uinfo, &info, info_len) ||
            put_user(info_len, &uattr->info.info_len))
                return -EFAULT;

        return 0;
}

static int bpf_btf_get_info_by_fd(struct file *file,
                                  struct btf *btf,
                                  const union bpf_attr *attr,
                                  union bpf_attr __user *uattr)
{
        struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
        u32 info_len = attr->info.info_len;
        int err;

        err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
        if (err)
                return err;

        return btf_get_info_by_fd(btf, attr, uattr);
}

static int bpf_link_get_info_by_fd(struct file *file,
                                  struct bpf_link *link,
                                  const union bpf_attr *attr,
                                  union bpf_attr __user *uattr)
{
        struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
        struct bpf_link_info info;
        u32 info_len = attr->info.info_len;
        int err;

        err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
        if (err)
                return err;
        info_len = min_t(u32, sizeof(info), info_len);

        memset(&info, 0, sizeof(info));
        if (copy_from_user(&info, uinfo, info_len))
                return -EFAULT;

        info.type = link->type;
        info.id = link->id;
        if (link->prog)
                info.prog_id = link->prog->aux->id;

        if (link->ops->fill_link_info) {
                err = link->ops->fill_link_info(link, &info);
                if (err)
                        return err;
        }

        if (copy_to_user(uinfo, &info, info_len) ||
            put_user(info_len, &uattr->info.info_len))
                return -EFAULT;

        return 0;
}


#define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info

static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
                                  union bpf_attr __user *uattr)
{
        int ufd = attr->info.bpf_fd;
        struct fd f;
        int err;

        if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
                return -EINVAL;

        f = fdget(ufd);
        if (!f.file)
                return -EBADFD;

        if (f.file->f_op == &bpf_prog_fops)
                err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
                                              uattr);
        else if (f.file->f_op == &bpf_map_fops)
                err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
                                             uattr);
        else if (f.file->f_op == &btf_fops)
                err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
        else if (f.file->f_op == &bpf_link_fops)
                err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
                                              attr, uattr);
        else
                err = -EINVAL;

        fdput(f);
        return err;
}

#define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size

static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
{
        if (CHECK_ATTR(BPF_BTF_LOAD))
                return -EINVAL;

        if (!bpf_capable())
                return -EPERM;

        return btf_new_fd(attr, uattr, uattr_size);
}

#define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id

static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
{
        if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
                return -EINVAL;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        return btf_get_fd_by_id(attr->btf_id);
}

static int bpf_task_fd_query_copy(const union bpf_attr *attr,
                                    union bpf_attr __user *uattr,
                                    u32 prog_id, u32 fd_type,
                                    const char *buf, u64 probe_offset,
                                    u64 probe_addr)
{
        char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
        u32 len = buf ? strlen(buf) : 0, input_len;
        int err = 0;

        if (put_user(len, &uattr->task_fd_query.buf_len))
                return -EFAULT;
        input_len = attr->task_fd_query.buf_len;
        if (input_len && ubuf) {
                if (!len) {
                        /* nothing to copy, just make ubuf NULL terminated */
                        char zero = '\0';

                        if (put_user(zero, ubuf))
                                return -EFAULT;
                } else if (input_len >= len + 1) {
                        /* ubuf can hold the string with NULL terminator */
                        if (copy_to_user(ubuf, buf, len + 1))
                                return -EFAULT;
                } else {
                        /* ubuf cannot hold the string with NULL terminator,
                         * do a partial copy with NULL terminator.
                         */
                        char zero = '\0';

                        err = -ENOSPC;
                        if (copy_to_user(ubuf, buf, input_len - 1))
                                return -EFAULT;
                        if (put_user(zero, ubuf + input_len - 1))
                                return -EFAULT;
                }
        }

        if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
            put_user(fd_type, &uattr->task_fd_query.fd_type) ||
            put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
            put_user(probe_addr, &uattr->task_fd_query.probe_addr))
                return -EFAULT;

        return err;
}

#define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr

static int bpf_task_fd_query(const union bpf_attr *attr,
                             union bpf_attr __user *uattr)
{
        pid_t pid = attr->task_fd_query.pid;
        u32 fd = attr->task_fd_query.fd;
        const struct perf_event *event;
        struct task_struct *task;
        struct file *file;
        int err;

        if (CHECK_ATTR(BPF_TASK_FD_QUERY))
                return -EINVAL;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        if (attr->task_fd_query.flags != 0)
                return -EINVAL;

        rcu_read_lock();
        task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
        rcu_read_unlock();
        if (!task)
                return -ENOENT;

        err = 0;
        file = fget_task(task, fd);
        put_task_struct(task);
        if (!file)
                return -EBADF;

        if (file->f_op == &bpf_link_fops) {
                struct bpf_link *link = file->private_data;

                if (link->ops == &bpf_raw_tp_link_lops) {
                        struct bpf_raw_tp_link *raw_tp =
                                container_of(link, struct bpf_raw_tp_link, link);
                        struct bpf_raw_event_map *btp = raw_tp->btp;

                        err = bpf_task_fd_query_copy(attr, uattr,
                                                     raw_tp->link.prog->aux->id,
                                                     BPF_FD_TYPE_RAW_TRACEPOINT,
                                                     btp->tp->name, 0, 0);
                        goto put_file;
                }
                goto out_not_supp;
        }

        event = perf_get_event(file);
        if (!IS_ERR(event)) {
                u64 probe_offset, probe_addr;
                u32 prog_id, fd_type;
                const char *buf;

                err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
                                              &buf, &probe_offset,
                                              &probe_addr, NULL);
                if (!err)
                        err = bpf_task_fd_query_copy(attr, uattr, prog_id,
                                                     fd_type, buf,
                                                     probe_offset,
                                                     probe_addr);
                goto put_file;
        }

out_not_supp:
        err = -ENOTSUPP;
put_file:
        fput(file);
        return err;
}

#define BPF_MAP_BATCH_LAST_FIELD batch.flags

#define BPF_DO_BATCH(fn, ...)                   \
        do {                                    \
                if (!fn) {                      \
                        err = -ENOTSUPP;        \
                        goto err_put;           \
                }                               \
                err = fn(__VA_ARGS__);          \
        } while (0)

static int bpf_map_do_batch(const union bpf_attr *attr,
                            union bpf_attr __user *uattr,
                            int cmd)
{
        bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
                         cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
        bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
        struct bpf_map *map;
        int err, ufd;
        struct fd f;

        if (CHECK_ATTR(BPF_MAP_BATCH))
                return -EINVAL;

        ufd = attr->batch.map_fd;
        f = fdget(ufd);
        map = __bpf_map_get(f);
        if (IS_ERR(map))
                return PTR_ERR(map);
        if (has_write)
                bpf_map_write_active_inc(map);
        if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
                err = -EPERM;
                goto err_put;
        }
        if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
                err = -EPERM;
                goto err_put;
        }

        if (cmd == BPF_MAP_LOOKUP_BATCH)
                BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
        else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
                BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
        else if (cmd == BPF_MAP_UPDATE_BATCH)
                BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr);
        else
                BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
err_put:
        if (has_write)
                bpf_map_write_active_dec(map);
        fdput(f);
        return err;
}

#define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
static int link_create(union bpf_attr *attr, bpfptr_t uattr)
{
        struct bpf_prog *prog;
        int ret;

        if (CHECK_ATTR(BPF_LINK_CREATE))
                return -EINVAL;

        if (attr->link_create.attach_type == BPF_STRUCT_OPS)
                return bpf_struct_ops_link_create(attr);

        prog = bpf_prog_get(attr->link_create.prog_fd);
        if (IS_ERR(prog))
                return PTR_ERR(prog);

        ret = bpf_prog_attach_check_attach_type(prog,
                                                attr->link_create.attach_type);
        if (ret)
                goto out;

        switch (prog->type) {
        case BPF_PROG_TYPE_CGROUP_SKB:
        case BPF_PROG_TYPE_CGROUP_SOCK:
        case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
        case BPF_PROG_TYPE_SOCK_OPS:
        case BPF_PROG_TYPE_CGROUP_DEVICE:
        case BPF_PROG_TYPE_CGROUP_SYSCTL:
        case BPF_PROG_TYPE_CGROUP_SOCKOPT:
                ret = cgroup_bpf_link_attach(attr, prog);
                break;
        case BPF_PROG_TYPE_EXT:
                ret = bpf_tracing_prog_attach(prog,
                                              attr->link_create.target_fd,
                                              attr->link_create.target_btf_id,
                                              attr->link_create.tracing.cookie);
                break;
        case BPF_PROG_TYPE_LSM:
        case BPF_PROG_TYPE_TRACING:
                if (attr->link_create.attach_type != prog->expected_attach_type) {
                        ret = -EINVAL;
                        goto out;
                }
                if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
                        ret = bpf_raw_tp_link_attach(prog, NULL);
                else if (prog->expected_attach_type == BPF_TRACE_ITER)
                        ret = bpf_iter_link_attach(attr, uattr, prog);
                else if (prog->expected_attach_type == BPF_LSM_CGROUP)
                        ret = cgroup_bpf_link_attach(attr, prog);
                else
                        ret = bpf_tracing_prog_attach(prog,
                                                      attr->link_create.target_fd,
                                                      attr->link_create.target_btf_id,
                                                      attr->link_create.tracing.cookie);
                break;
        case BPF_PROG_TYPE_FLOW_DISSECTOR:
        case BPF_PROG_TYPE_SK_LOOKUP:
                ret = netns_bpf_link_create(attr, prog);
                break;
#ifdef CONFIG_NET
        case BPF_PROG_TYPE_XDP:
                ret = bpf_xdp_link_attach(attr, prog);
                break;
        case BPF_PROG_TYPE_SCHED_CLS:
                if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
                    attr->link_create.attach_type == BPF_TCX_EGRESS)
                        ret = tcx_link_attach(attr, prog);
                else
                        ret = netkit_link_attach(attr, prog);
                break;
        case BPF_PROG_TYPE_NETFILTER:
                ret = bpf_nf_link_attach(attr, prog);
                break;
#endif
        case BPF_PROG_TYPE_PERF_EVENT:
        case BPF_PROG_TYPE_TRACEPOINT:
                ret = bpf_perf_link_attach(attr, prog);
                break;
        case BPF_PROG_TYPE_KPROBE:
                if (attr->link_create.attach_type == BPF_PERF_EVENT)
                        ret = bpf_perf_link_attach(attr, prog);
                else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI)
                        ret = bpf_kprobe_multi_link_attach(attr, prog);
                else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI)
                        ret = bpf_uprobe_multi_link_attach(attr, prog);
                break;
        default:
                ret = -EINVAL;
        }

out:
        if (ret < 0)
                bpf_prog_put(prog);
        return ret;
}

static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
{
        struct bpf_map *new_map, *old_map = NULL;
        int ret;

        new_map = bpf_map_get(attr->link_update.new_map_fd);
        if (IS_ERR(new_map))
                return PTR_ERR(new_map);

        if (attr->link_update.flags & BPF_F_REPLACE) {
                old_map = bpf_map_get(attr->link_update.old_map_fd);
                if (IS_ERR(old_map)) {
                        ret = PTR_ERR(old_map);
                        goto out_put;
                }
        } else if (attr->link_update.old_map_fd) {
                ret = -EINVAL;
                goto out_put;
        }

        ret = link->ops->update_map(link, new_map, old_map);

        if (old_map)
                bpf_map_put(old_map);
out_put:
        bpf_map_put(new_map);
        return ret;
}

#define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd

static int link_update(union bpf_attr *attr)
{
        struct bpf_prog *old_prog = NULL, *new_prog;
        struct bpf_link *link;
        u32 flags;
        int ret;

        if (CHECK_ATTR(BPF_LINK_UPDATE))
                return -EINVAL;

        flags = attr->link_update.flags;
        if (flags & ~BPF_F_REPLACE)
                return -EINVAL;

        link = bpf_link_get_from_fd(attr->link_update.link_fd);
        if (IS_ERR(link))
                return PTR_ERR(link);

        if (link->ops->update_map) {
                ret = link_update_map(link, attr);
                goto out_put_link;
        }

        new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
        if (IS_ERR(new_prog)) {
                ret = PTR_ERR(new_prog);
                goto out_put_link;
        }

        if (flags & BPF_F_REPLACE) {
                old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
                if (IS_ERR(old_prog)) {
                        ret = PTR_ERR(old_prog);
                        old_prog = NULL;
                        goto out_put_progs;
                }
        } else if (attr->link_update.old_prog_fd) {
                ret = -EINVAL;
                goto out_put_progs;
        }

        if (link->ops->update_prog)
                ret = link->ops->update_prog(link, new_prog, old_prog);
        else
                ret = -EINVAL;

out_put_progs:
        if (old_prog)
                bpf_prog_put(old_prog);
        if (ret)
                bpf_prog_put(new_prog);
out_put_link:
        bpf_link_put_direct(link);
        return ret;
}

#define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd

static int link_detach(union bpf_attr *attr)
{
        struct bpf_link *link;
        int ret;

        if (CHECK_ATTR(BPF_LINK_DETACH))
                return -EINVAL;

        link = bpf_link_get_from_fd(attr->link_detach.link_fd);
        if (IS_ERR(link))
                return PTR_ERR(link);

        if (link->ops->detach)
                ret = link->ops->detach(link);
        else
                ret = -EOPNOTSUPP;

        bpf_link_put_direct(link);
        return ret;
}

static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
{
        return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
}

struct bpf_link *bpf_link_by_id(u32 id)
{
        struct bpf_link *link;

        if (!id)
                return ERR_PTR(-ENOENT);

        spin_lock_bh(&link_idr_lock);
        /* before link is "settled", ID is 0, pretend it doesn't exist yet */
        link = idr_find(&link_idr, id);
        if (link) {
                if (link->id)
                        link = bpf_link_inc_not_zero(link);
                else
                        link = ERR_PTR(-EAGAIN);
        } else {
                link = ERR_PTR(-ENOENT);
        }
        spin_unlock_bh(&link_idr_lock);
        return link;
}

struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
{
        struct bpf_link *link;

        spin_lock_bh(&link_idr_lock);
again:
        link = idr_get_next(&link_idr, id);
        if (link) {
                link = bpf_link_inc_not_zero(link);
                if (IS_ERR(link)) {
                        (*id)++;
                        goto again;
                }
        }
        spin_unlock_bh(&link_idr_lock);

        return link;
}

#define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id

static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
{
        struct bpf_link *link;
        u32 id = attr->link_id;
        int fd;

        if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
                return -EINVAL;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        link = bpf_link_by_id(id);
        if (IS_ERR(link))
                return PTR_ERR(link);

        fd = bpf_link_new_fd(link);
        if (fd < 0)
                bpf_link_put_direct(link);

        return fd;
}

DEFINE_MUTEX(bpf_stats_enabled_mutex);

static int bpf_stats_release(struct inode *inode, struct file *file)
{
        mutex_lock(&bpf_stats_enabled_mutex);
        static_key_slow_dec(&bpf_stats_enabled_key.key);
        mutex_unlock(&bpf_stats_enabled_mutex);
        return 0;
}

static const struct file_operations bpf_stats_fops = {
        .release = bpf_stats_release,
};

static int bpf_enable_runtime_stats(void)
{
        int fd;

        mutex_lock(&bpf_stats_enabled_mutex);

        /* Set a very high limit to avoid overflow */
        if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
                mutex_unlock(&bpf_stats_enabled_mutex);
                return -EBUSY;
        }

        fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
        if (fd >= 0)
                static_key_slow_inc(&bpf_stats_enabled_key.key);

        mutex_unlock(&bpf_stats_enabled_mutex);
        return fd;
}

#define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type

static int bpf_enable_stats(union bpf_attr *attr)
{

        if (CHECK_ATTR(BPF_ENABLE_STATS))
                return -EINVAL;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;

        switch (attr->enable_stats.type) {
        case BPF_STATS_RUN_TIME:
                return bpf_enable_runtime_stats();
        default:
                break;
        }
        return -EINVAL;
}

#define BPF_ITER_CREATE_LAST_FIELD iter_create.flags

static int bpf_iter_create(union bpf_attr *attr)
{
        struct bpf_link *link;
        int err;

        if (CHECK_ATTR(BPF_ITER_CREATE))
                return -EINVAL;

        if (attr->iter_create.flags)
                return -EINVAL;

        link = bpf_link_get_from_fd(attr->iter_create.link_fd);
        if (IS_ERR(link))
                return PTR_ERR(link);

        err = bpf_iter_new_fd(link);
        bpf_link_put_direct(link);

        return err;
}

#define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags

static int bpf_prog_bind_map(union bpf_attr *attr)
{
        struct bpf_prog *prog;
        struct bpf_map *map;
        struct bpf_map **used_maps_old, **used_maps_new;
        int i, ret = 0;

        if (CHECK_ATTR(BPF_PROG_BIND_MAP))
                return -EINVAL;

        if (attr->prog_bind_map.flags)
                return -EINVAL;

        prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
        if (IS_ERR(prog))
                return PTR_ERR(prog);

        map = bpf_map_get(attr->prog_bind_map.map_fd);
        if (IS_ERR(map)) {
                ret = PTR_ERR(map);
                goto out_prog_put;
        }

        mutex_lock(&prog->aux->used_maps_mutex);

        used_maps_old = prog->aux->used_maps;

        for (i = 0; i < prog->aux->used_map_cnt; i++)
                if (used_maps_old[i] == map) {
                        bpf_map_put(map);
                        goto out_unlock;
                }

        used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
                                      sizeof(used_maps_new[0]),
                                      GFP_KERNEL);
        if (!used_maps_new) {
                ret = -ENOMEM;
                goto out_unlock;
        }

        memcpy(used_maps_new, used_maps_old,
               sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
        used_maps_new[prog->aux->used_map_cnt] = map;

        prog->aux->used_map_cnt++;
        prog->aux->used_maps = used_maps_new;

        kfree(used_maps_old);

out_unlock:
        mutex_unlock(&prog->aux->used_maps_mutex);

        if (ret)
                bpf_map_put(map);
out_prog_put:
        bpf_prog_put(prog);
        return ret;
}

static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
{
        union bpf_attr attr;
        int err;

        err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
        if (err)
                return err;
        size = min_t(u32, size, sizeof(attr));

        /* copy attributes from user space, may be less than sizeof(bpf_attr) */
        memset(&attr, 0, sizeof(attr));
        if (copy_from_bpfptr(&attr, uattr, size) != 0)
                return -EFAULT;

        err = security_bpf(cmd, &attr, size);
        if (err < 0)
                return err;

        switch (cmd) {
        case BPF_MAP_CREATE:
                err = map_create(&attr);
                break;
        case BPF_MAP_LOOKUP_ELEM:
                err = map_lookup_elem(&attr);
                break;
        case BPF_MAP_UPDATE_ELEM:
                err = map_update_elem(&attr, uattr);
                break;
        case BPF_MAP_DELETE_ELEM:
                err = map_delete_elem(&attr, uattr);
                break;
        case BPF_MAP_GET_NEXT_KEY:
                err = map_get_next_key(&attr);
                break;
        case BPF_MAP_FREEZE:
                err = map_freeze(&attr);
                break;
        case BPF_PROG_LOAD:
                err = bpf_prog_load(&attr, uattr, size);
                break;
        case BPF_OBJ_PIN:
                err = bpf_obj_pin(&attr);
                break;
        case BPF_OBJ_GET:
                err = bpf_obj_get(&attr);
                break;
        case BPF_PROG_ATTACH:
                err = bpf_prog_attach(&attr);
                break;
        case BPF_PROG_DETACH:
                err = bpf_prog_detach(&attr);
                break;
        case BPF_PROG_QUERY:
                err = bpf_prog_query(&attr, uattr.user);
                break;
        case BPF_PROG_TEST_RUN:
                err = bpf_prog_test_run(&attr, uattr.user);
                break;
        case BPF_PROG_GET_NEXT_ID:
                err = bpf_obj_get_next_id(&attr, uattr.user,
                                          &prog_idr, &prog_idr_lock);
                break;
        case BPF_MAP_GET_NEXT_ID:
                err = bpf_obj_get_next_id(&attr, uattr.user,
                                          &map_idr, &map_idr_lock);
                break;
        case BPF_BTF_GET_NEXT_ID:
                err = bpf_obj_get_next_id(&attr, uattr.user,
                                          &btf_idr, &btf_idr_lock);
                break;
        case BPF_PROG_GET_FD_BY_ID:
                err = bpf_prog_get_fd_by_id(&attr);
                break;
        case BPF_MAP_GET_FD_BY_ID:
                err = bpf_map_get_fd_by_id(&attr);
                break;
        case BPF_OBJ_GET_INFO_BY_FD:
                err = bpf_obj_get_info_by_fd(&attr, uattr.user);
                break;
        case BPF_RAW_TRACEPOINT_OPEN:
                err = bpf_raw_tracepoint_open(&attr);
                break;
        case BPF_BTF_LOAD:
                err = bpf_btf_load(&attr, uattr, size);
                break;
        case BPF_BTF_GET_FD_BY_ID:
                err = bpf_btf_get_fd_by_id(&attr);
                break;
        case BPF_TASK_FD_QUERY:
                err = bpf_task_fd_query(&attr, uattr.user);
                break;
        case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
                err = map_lookup_and_delete_elem(&attr);
                break;
        case BPF_MAP_LOOKUP_BATCH:
                err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
                break;
        case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
                err = bpf_map_do_batch(&attr, uattr.user,
                                       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
                break;
        case BPF_MAP_UPDATE_BATCH:
                err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
                break;
        case BPF_MAP_DELETE_BATCH:
                err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
                break;
        case BPF_LINK_CREATE:
                err = link_create(&attr, uattr);
                break;
        case BPF_LINK_UPDATE:
                err = link_update(&attr);
                break;
        case BPF_LINK_GET_FD_BY_ID:
                err = bpf_link_get_fd_by_id(&attr);
                break;
        case BPF_LINK_GET_NEXT_ID:
                err = bpf_obj_get_next_id(&attr, uattr.user,
                                          &link_idr, &link_idr_lock);
                break;
        case BPF_ENABLE_STATS:
                err = bpf_enable_stats(&attr);
                break;
        case BPF_ITER_CREATE:
                err = bpf_iter_create(&attr);
                break;
        case BPF_LINK_DETACH:
                err = link_detach(&attr);
                break;
        case BPF_PROG_BIND_MAP:
                err = bpf_prog_bind_map(&attr);
                break;
        default:
                err = -EINVAL;
                break;
        }

        return err;
}

SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
        return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
}

static bool syscall_prog_is_valid_access(int off, int size,
                                         enum bpf_access_type type,
                                         const struct bpf_prog *prog,
                                         struct bpf_insn_access_aux *info)
{
        if (off < 0 || off >= U16_MAX)
                return false;
        if (off % size != 0)
                return false;
        return true;
}

BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
{
        switch (cmd) {
        case BPF_MAP_CREATE:
        case BPF_MAP_DELETE_ELEM:
        case BPF_MAP_UPDATE_ELEM:
        case BPF_MAP_FREEZE:
        case BPF_MAP_GET_FD_BY_ID:
        case BPF_PROG_LOAD:
        case BPF_BTF_LOAD:
        case BPF_LINK_CREATE:
        case BPF_RAW_TRACEPOINT_OPEN:
                break;
        default:
                return -EINVAL;
        }
        return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
}


/* To shut up -Wmissing-prototypes.
 * This function is used by the kernel light skeleton
 * to load bpf programs when modules are loaded or during kernel boot.
 * See tools/lib/bpf/skel_internal.h
 */
int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);

int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
{
        struct bpf_prog * __maybe_unused prog;
        struct bpf_tramp_run_ctx __maybe_unused run_ctx;

        switch (cmd) {
#ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
        case BPF_PROG_TEST_RUN:
                if (attr->test.data_in || attr->test.data_out ||
                    attr->test.ctx_out || attr->test.duration ||
                    attr->test.repeat || attr->test.flags)
                        return -EINVAL;

                prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
                if (IS_ERR(prog))
                        return PTR_ERR(prog);

                if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
                    attr->test.ctx_size_in > U16_MAX) {
                        bpf_prog_put(prog);
                        return -EINVAL;
                }

                run_ctx.bpf_cookie = 0;
                if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
                        /* recursion detected */
                        __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
                        bpf_prog_put(prog);
                        return -EBUSY;
                }
                attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
                __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
                                                &run_ctx);
                bpf_prog_put(prog);
                return 0;
#endif
        default:
                return ____bpf_sys_bpf(cmd, attr, size);
        }
}
EXPORT_SYMBOL(kern_sys_bpf);

static const struct bpf_func_proto bpf_sys_bpf_proto = {
        .func           = bpf_sys_bpf,
        .gpl_only       = false,
        .ret_type       = RET_INTEGER,
        .arg1_type      = ARG_ANYTHING,
        .arg2_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
        .arg3_type      = ARG_CONST_SIZE,
};

const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        return bpf_base_func_proto(func_id);
}

BPF_CALL_1(bpf_sys_close, u32, fd)
{
        /* When bpf program calls this helper there should not be
         * an fdget() without matching completed fdput().
         * This helper is allowed in the following callchain only:
         * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
         */
        return close_fd(fd);
}

static const struct bpf_func_proto bpf_sys_close_proto = {
        .func           = bpf_sys_close,
        .gpl_only       = false,
        .ret_type       = RET_INTEGER,
        .arg1_type      = ARG_ANYTHING,
};

BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
{
        if (flags)
                return -EINVAL;

        if (name_sz <= 1 || name[name_sz - 1])
                return -EINVAL;

        if (!bpf_dump_raw_ok(current_cred()))
                return -EPERM;

        *res = kallsyms_lookup_name(name);
        return *res ? 0 : -ENOENT;
}

static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
        .func           = bpf_kallsyms_lookup_name,
        .gpl_only       = false,
        .ret_type       = RET_INTEGER,
        .arg1_type      = ARG_PTR_TO_MEM,
        .arg2_type      = ARG_CONST_SIZE_OR_ZERO,
        .arg3_type      = ARG_ANYTHING,
        .arg4_type      = ARG_PTR_TO_LONG,
};

static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
        switch (func_id) {
        case BPF_FUNC_sys_bpf:
                return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto;
        case BPF_FUNC_btf_find_by_name_kind:
                return &bpf_btf_find_by_name_kind_proto;
        case BPF_FUNC_sys_close:
                return &bpf_sys_close_proto;
        case BPF_FUNC_kallsyms_lookup_name:
                return &bpf_kallsyms_lookup_name_proto;
        default:
                return tracing_prog_func_proto(func_id, prog);
        }
}

const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
        .get_func_proto  = syscall_prog_func_proto,
        .is_valid_access = syscall_prog_is_valid_access,
};

const struct bpf_prog_ops bpf_syscall_prog_ops = {
        .test_run = bpf_prog_test_run_syscall,
};

#ifdef CONFIG_SYSCTL
static int bpf_stats_handler(struct ctl_table *table, int write,
                             void *buffer, size_t *lenp, loff_t *ppos)
{
        struct static_key *key = (struct static_key *)table->data;
        static int saved_val;
        int val, ret;
        struct ctl_table tmp = {
                .data   = &val,
                .maxlen = sizeof(val),
                .mode   = table->mode,
                .extra1 = SYSCTL_ZERO,
                .extra2 = SYSCTL_ONE,
        };

        if (write && !capable(CAP_SYS_ADMIN))
                return -EPERM;

        mutex_lock(&bpf_stats_enabled_mutex);
        val = saved_val;
        ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
        if (write && !ret && val != saved_val) {
                if (val)
                        static_key_slow_inc(key);
                else
                        static_key_slow_dec(key);
                saved_val = val;
        }
        mutex_unlock(&bpf_stats_enabled_mutex);
        return ret;
}

void __weak unpriv_ebpf_notify(int new_state)
{
}

static int bpf_unpriv_handler(struct ctl_table *table, int write,
                              void *buffer, size_t *lenp, loff_t *ppos)
{
        int ret, unpriv_enable = *(int *)table->data;
        bool locked_state = unpriv_enable == 1;
        struct ctl_table tmp = *table;

        if (write && !capable(CAP_SYS_ADMIN))
                return -EPERM;

        tmp.data = &unpriv_enable;
        ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
        if (write && !ret) {
                if (locked_state && unpriv_enable != 1)
                        return -EPERM;
                *(int *)table->data = unpriv_enable;
        }

        if (write)
                unpriv_ebpf_notify(unpriv_enable);

        return ret;
}

static struct ctl_table bpf_syscall_table[] = {
        {
                .procname       = "unprivileged_bpf_disabled",
                .data           = &sysctl_unprivileged_bpf_disabled,
                .maxlen         = sizeof(sysctl_unprivileged_bpf_disabled),
                .mode           = 0644,
                .proc_handler   = bpf_unpriv_handler,
                .extra1         = SYSCTL_ZERO,
                .extra2         = SYSCTL_TWO,
        },
        {
                .procname       = "bpf_stats_enabled",
                .data           = &bpf_stats_enabled_key.key,
                .mode           = 0644,
                .proc_handler   = bpf_stats_handler,
        },
        { }
};

static int __init bpf_syscall_sysctl_init(void)
{
        register_sysctl_init("kernel", bpf_syscall_table);
        return 0;
}
late_initcall(bpf_syscall_sysctl_init);
#endif /* CONFIG_SYSCTL */