// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
 */
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/bpf_lirc.h>
#include <linux/bpf_verifier.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/bpf-netns.h>
#include <linux/rcupdate_trace.h>
#include <linux/memcontrol.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,
};

static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
{
        const struct bpf_map_ops *ops;
        u32 type = attr->map_type;
        struct bpf_map *map;
        int err;

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

        if (ops->map_alloc_check) {
                err = ops->map_alloc_check(attr);
                if (err)
                        return ERR_PTR(err);
        }
        if (attr->map_ifindex)
                ops = &bpf_map_offload_ops;
        map = ops->map_alloc(attr);
        if (IS_ERR(map))
                return map;
        map->ops = ops;
        map->map_type = type;
        return map;
}

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 fd f, void *key,
                                void *value, __u64 flags)
{
        int err;

        /* Need to create a kthread, thus must support schedule */
        if (bpf_map_is_dev_bound(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, f.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, f.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, f.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) {
                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_dev_bound(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) {
                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.
         */

        const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_ACCOUNT;
        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);
}

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, bool do_idr_lock)
{
        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;

        if (do_idr_lock)
                spin_lock_irqsave(&map_idr_lock, flags);
        else
                __acquire(&map_idr_lock);

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

        if (do_idr_lock)
                spin_unlock_irqrestore(&map_idr_lock, flags);
        else
                __release(&map_idr_lock);
}

#ifdef CONFIG_MEMCG_KMEM
static void bpf_map_save_memcg(struct bpf_map *map)
{
        map->memcg = get_mem_cgroup_from_mm(current->mm);
}

static void bpf_map_release_memcg(struct bpf_map *map)
{
        mem_cgroup_put(map->memcg);
}

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

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

        return ptr;
}

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

        old_memcg = set_active_memcg(map->memcg);
        ptr = kzalloc(size, flags | __GFP_ACCOUNT);
        set_active_memcg(old_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 *old_memcg;
        void __percpu *ptr;

        old_memcg = set_active_memcg(map->memcg);
        ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
        set_active_memcg(old_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

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

        security_bpf_map_free(map);
        bpf_map_release_memcg(map);
        /* implementation dependent freeing */
        map->ops->map_free(map);
}

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
 * (unrelying map implementation ops->map_free() might sleep)
 */
static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
{
        if (atomic64_dec_and_test(&map->refcnt)) {
                /* bpf_map_free_id() must be called first */
                bpf_map_free_id(map, do_idr_lock);
                btf_put(map->btf);
                INIT_WORK(&map->work, bpf_map_free_deferred);
                schedule_work(&map->work);
        }
}

void bpf_map_put(struct bpf_map *map)
{
        __bpf_map_put(map, true);
}
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
/* Provides an approximation of the map's memory footprint.
 * Used only to provide a backward compatibility and display
 * a reasonable "memlock" info.
 */
static unsigned long bpf_map_memory_footprint(const struct bpf_map *map)
{
        unsigned long size;

        size = round_up(map->key_size + bpf_map_value_size(map), 8);

        return round_up(map->max_entries * size, PAGE_SIZE);
}

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

        if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
                array = container_of(map, struct bpf_array, map);
                spin_lock(&array->aux->owner.lock);
                type  = array->aux->owner.type;
                jited = array->aux->owner.jited;
                spin_unlock(&array->aux->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"
                   "memlock:\t%lu\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,
                   bpf_map_memory_footprint(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) {
                mutex_lock(&map->freeze_mutex);
                map->writecnt++;
                mutex_unlock(&map->freeze_mutex);
        }
}

/* 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) {
                mutex_lock(&map->freeze_mutex);
                map->writecnt--;
                mutex_unlock(&map->freeze_mutex);
        }
}

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 || map_value_has_spin_lock(map) ||
            map_value_has_timer(map))
                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;
        vma->vm_flags &= ~VM_MAYEXEC;
        if (!(vma->vm_flags & VM_WRITE))
                /* disallow re-mapping with PROT_WRITE */
                vma->vm_flags &= ~VM_MAYWRITE;

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

        if (vma->vm_flags & VM_MAYWRITE)
                map->writecnt++;
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->spin_lock_off = btf_find_spin_lock(btf, value_type);

        if (map_value_has_spin_lock(map)) {
                if (map->map_flags & BPF_F_RDONLY_PROG)
                        return -EACCES;
                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)
                        return -ENOTSUPP;
                if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
                    map->value_size) {
                        WARN_ONCE(1,
                                  "verifier bug spin_lock_off %d value_size %d\n",
                                  map->spin_lock_off, map->value_size);
                        return -EFAULT;
                }
        }

        map->timer_off = btf_find_timer(btf, value_type);
        if (map_value_has_timer(map)) {
                if (map->map_flags & BPF_F_RDONLY_PROG)
                        return -EACCES;
                if (map->map_type != BPF_MAP_TYPE_HASH &&
                    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
                    map->map_type != BPF_MAP_TYPE_ARRAY)
                        return -EOPNOTSUPP;
        }

        if (map->ops->map_check_btf)
                ret = map->ops->map_check_btf(map, btf, key_type, value_type);

        return ret;
}

#define BPF_MAP_CREATE_LAST_FIELD btf_vmlinux_value_type_id
/* called via syscall */
static int map_create(union bpf_attr *attr)
{
        int numa_node = bpf_map_attr_numa_node(attr);
        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;
        }

        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 = find_and_alloc_map(attr);
        if (IS_ERR(map))
                return PTR_ERR(map);

        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);

        map->spin_lock_off = -EINVAL;
        map->timer_off = -EINVAL;
        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;
}

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 */
static 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) &&
            !map_value_has_spin_lock(map)) {
                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 = 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);
        if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
                err = -EPERM;
                goto err_put;
        }

        if ((attr->flags & BPF_F_LOCK) &&
            !map_value_has_spin_lock(map)) {
                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 = -EFAULT;
        if (copy_from_bpfptr(value, uvalue, value_size) != 0)
                goto free_value;

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

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

#define BPF_MAP_DELETE_ELEM_LAST_FIELD key

static int map_delete_elem(union bpf_attr *attr)
{
        void __user *ukey = u64_to_user_ptr(attr->key);
        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);
        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_dev_bound(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:
        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_dev_bound(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) &&
            !map_value_has_spin_lock(map)) {
                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_dev_bound(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();
                maybe_wait_bpf_programs(map);
                if (err)
                        break;
        }
        if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
                err = -EFAULT;

        kvfree(key);
        return err;
}

int generic_map_update_batch(struct bpf_map *map,
                             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;
        int ufd = attr->batch.map_fd;
        void *key, *value;
        struct fd f;
        int err = 0;

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

        if ((attr->batch.elem_flags & BPF_F_LOCK) &&
            !map_value_has_spin_lock(map)) {
                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;
        }

        f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
        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, f, key, value,
                                           attr->batch.elem_flags);

                if (err)
                        break;
        }

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

        kvfree(value);
        kvfree(key);
        fdput(f);
        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) &&
            !map_value_has_spin_lock(map))
                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++;
        }

        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);
        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) &&
            !map_value_has_spin_lock(map)) {
                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_dev_bound(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:
        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 ||
            map_value_has_timer(map)) {
                fdput(f);
                return -ENOTSUPP;
        }

        mutex_lock(&map->freeze_mutex);

        if (map->writecnt) {
                err = -EBUSY;
                goto err_put;
        }
        if (READ_ONCE(map->frozen)) {
                err = -EBUSY;
                goto err_put;
        }
        if (!bpf_capable()) {
                err = -EPERM;
                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_dev_bound(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 (op == BPF_AUDIT_LOAD)
                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, bool do_idr_lock)
{
        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;

        if (do_idr_lock)
                spin_lock_irqsave(&prog_idr_lock, flags);
        else
                __acquire(&prog_idr_lock);

        idr_remove(&prog_idr, prog->aux->id);
        prog->aux->id = 0;

        if (do_idr_lock)
                spin_unlock_irqrestore(&prog_idr_lock, flags);
        else
                __release(&prog_idr_lock);
}

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);
        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_put_noref(prog, true);
}

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

        if (atomic64_dec_and_test(&aux->refcnt)) {
                /* bpf_prog_free_id() must be called first */
                bpf_prog_free_id(prog, do_idr_lock);

                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, true);
}
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;
}

static void bpf_prog_get_stats(const struct bpf_prog *prog,
                               struct bpf_prog_stats *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_irq(&st->syncp);
                        tnsecs = st->nsecs;
                        tcnt = st->cnt;
                        tmisses = st->misses;
                } while (u64_stats_fetch_retry_irq(&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_stats 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",
                   prog->type,
                   prog->jited,
                   prog_tag,
                   prog->pages * 1ULL << PAGE_SHIFT,
                   prog->aux->id,
                   stats.nsecs,
                   stats.cnt,
                   stats.misses);
}
#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_dev_bound(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_INET4_GETPEERNAME:
                case BPF_CGROUP_INET6_GETPEERNAME:
                case BPF_CGROUP_INET4_GETSOCKNAME:
                case BPF_CGROUP_INET6_GETSOCKNAME:
                case BPF_CGROUP_UDP4_SENDMSG:
                case BPF_CGROUP_UDP6_SENDMSG:
                case BPF_CGROUP_UDP4_RECVMSG:
                case BPF_CGROUP_UDP6_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_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_LIRC_MODE2:
        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 */
                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 fd_array

static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
{
        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];
        bool is_gpl;

        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))
                return -EINVAL;

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

        /* copy eBPF program license from user space */
        if (strncpy_from_bpfptr(license,
                                make_bpfptr(attr->license, uattr.is_kernel),
                                sizeof(license) - 1) < 0)
                return -EFAULT;
        license[sizeof(license) - 1] = 0;

        /* eBPF programs must be GPL compatible to use GPL-ed functions */
        is_gpl = license_is_gpl_compatible(license);

        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->offload_requested = !!attr->prog_ifindex;
        prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;

        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;

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

        atomic64_set(&prog->aux->refcnt, 1);
        prog->gpl_compatible = is_gpl ? 1 : 0;

        if (bpf_prog_is_dev_bound(prog->aux)) {
                err = bpf_prog_offload_init(prog, attr);
                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);
        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->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 file_flags

static int bpf_obj_pin(const union bpf_attr *attr)
{
        if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
                return -EINVAL;

        return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
}

static int bpf_obj_get(const union bpf_attr *attr)
{
        if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
            attr->file_flags & ~BPF_OBJ_FLAG_MASK)
                return -EINVAL;

        return bpf_obj_get_user(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 marksbpf_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.
 */
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 can be called from atomic context, but ensures that resources
 * are freed from process context
 */
void bpf_link_put(struct bpf_link *link)
{
        if (!atomic64_dec_and_test(&link->refcnt))
                return;

        if (in_atomic()) {
                INIT_WORK(&link->work, bpf_link_put_deferred);
                schedule_work(&link->work);
        } else {
                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(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] = { };

        bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
        seq_printf(m,
                   "link_type:\t%s\n"
                   "link_id:\t%u\n"
                   "prog_tag:\t%s\n"
                   "prog_id:\t%u\n",
                   bpf_link_type_strs[link->type],
                   link->id,
                   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 inbetween 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;
}

struct bpf_tracing_link {
        struct bpf_link link;
        enum bpf_attach_type attach_type;
        struct bpf_trampoline *trampoline;
        struct bpf_prog *tgt_prog;
};

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

        WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog,
                                                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);

        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);

        seq_printf(seq,
                   "attach_type:\t%d\n",
                   tr_link->attach_type);
}

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);

        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)
{
        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, BPF_LINK_TYPE_TRACING,
                      &bpf_tracing_link_lops, prog);
        link->attach_type = prog->expected_attach_type;

        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;

                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_primer);
        if (err)
                goto out_unlock;

        err = bpf_trampoline_link_prog(prog, 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_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;

        if (ulen >= tp_len + 1) {
                if (copy_to_user(ubuf, tp_name, tp_len + 1))
                        return -EFAULT;
        } else {
                char zero = '\0';

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

        return 0;
}

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

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;
}
#endif /* CONFIG_PERF_EVENTS */

#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd

static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
{
        struct bpf_link_primer link_primer;
        struct bpf_raw_tp_link *link;
        struct bpf_raw_event_map *btp;
        struct bpf_prog *prog;
        const char *tp_name;
        char buf[128];
        int err;

        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);

        switch (prog->type) {
        case BPF_PROG_TYPE_TRACING:
        case BPF_PROG_TYPE_EXT: