/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of version 2 of the GNU General Public
   * License as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * General Public License for more details.
   */
  #include <linux/bpf.h>

  #include <linux/bpf_trace.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/file.h>

  #include <linux/license.h>
  #include <linux/filter.h>

  #include <linux/version.h>

  #include <linux/kernel.h>

  #include <linux/idr.h>

  #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
  			   (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_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
  #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))

  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);

  int sysctl_unprivileged_bpf_disabled __read_mostly;

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

  static int check_uarg_tail_zero(void __user *uaddr,
  				size_t expected_size,
  				size_t actual_size)
  {
  	unsigned char __user *addr;
  	unsigned char __user *end;
  	unsigned char val;
  	int err;

  	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
  		return -E2BIG;
  
  	if (unlikely(!access_ok(VERIFY_READ, uaddr, actual_size)))
  		return -EFAULT;

  	if (actual_size <= expected_size)
  		return 0;
  
  	addr = uaddr + expected_size;
  	end  = uaddr + actual_size;
  
  	for (; addr < end; addr++) {
  		err = get_user(val, addr);
  		if (err)
  			return err;
  		if (val)
  			return -E2BIG;
  	}
  
  	return 0;
  }

  static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
  {

  	struct bpf_map *map;

  	if (attr->map_type >= ARRAY_SIZE(bpf_map_types) ||
  	    !bpf_map_types[attr->map_type])
  		return ERR_PTR(-EINVAL);

  	map = bpf_map_types[attr->map_type]->map_alloc(attr);
  	if (IS_ERR(map))
  		return map;
  	map->ops = bpf_map_types[attr->map_type];
  	map->map_type = attr->map_type;
  	return map;

  }

  void *bpf_map_area_alloc(size_t size, int numa_node)

  {
  	/* We definitely need __GFP_NORETRY, so OOM killer doesn't
  	 * trigger under memory pressure as we really just want to
  	 * fail instead.
  	 */
  	const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
  	void *area;
  
  	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {

  		area = kmalloc_node(size, GFP_USER | flags, numa_node);

  		if (area != NULL)
  			return area;
  	}

  	return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
  					   __builtin_return_address(0));

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

  int bpf_map_precharge_memlock(u32 pages)
  {
  	struct user_struct *user = get_current_user();
  	unsigned long memlock_limit, cur;
  
  	memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  	cur = atomic_long_read(&user->locked_vm);
  	free_uid(user);
  	if (cur + pages > memlock_limit)
  		return -EPERM;
  	return 0;
  }

  static int bpf_map_charge_memlock(struct bpf_map *map)
  {
  	struct user_struct *user = get_current_user();
  	unsigned long memlock_limit;
  
  	memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  
  	atomic_long_add(map->pages, &user->locked_vm);
  
  	if (atomic_long_read(&user->locked_vm) > memlock_limit) {
  		atomic_long_sub(map->pages, &user->locked_vm);
  		free_uid(user);
  		return -EPERM;
  	}
  	map->user = user;
  	return 0;
  }
  
  static void bpf_map_uncharge_memlock(struct bpf_map *map)
  {
  	struct user_struct *user = map->user;
  
  	atomic_long_sub(map->pages, &user->locked_vm);
  	free_uid(user);
  }

  static int bpf_map_alloc_id(struct bpf_map *map)
  {
  	int id;
  
  	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);
  
  	if (WARN_ON_ONCE(!id))
  		return -ENOSPC;
  
  	return id > 0 ? 0 : id;
  }

  static void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)

  {

  	unsigned long flags;

  	if (do_idr_lock)

  		spin_lock_irqsave(&map_idr_lock, flags);

  	else
  		__acquire(&map_idr_lock);

  	idr_remove(&map_idr, map->id);

  
  	if (do_idr_lock)

  		spin_unlock_irqrestore(&map_idr_lock, flags);

  	else
  		__release(&map_idr_lock);

  }

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

  	bpf_map_uncharge_memlock(map);

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

  static void bpf_map_put_uref(struct bpf_map *map)
  {
  	if (atomic_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 (atomic_dec_and_test(&map->refcnt)) {

  		/* bpf_map_free_id() must be called first */

  		bpf_map_free_id(map, do_idr_lock);

  		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);
  }

  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;
  }

  #ifdef CONFIG_PROC_FS
  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 owner_prog_type = 0;

  	u32 owner_jited = 0;

  
  	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
  		array = container_of(map, struct bpf_array, map);
  		owner_prog_type = array->owner_prog_type;

  		owner_jited = array->owner_jited;

  	}

  
  	seq_printf(m,
  		   "map_type:\t%u
  "
  		   "key_size:\t%u
  "
  		   "value_size:\t%u
  "

  		   "max_entries:\t%u
  "

  		   "map_flags:\t%#x
  "
  		   "memlock:\t%llu
  ",

  		   map->map_type,
  		   map->key_size,
  		   map->value_size,

  		   map->max_entries,

  		   map->map_flags,
  		   map->pages * 1ULL << PAGE_SHIFT);

  	if (owner_prog_type) {

  		seq_printf(m, "owner_prog_type:\t%u
  ",
  			   owner_prog_type);

  		seq_printf(m, "owner_jited:\t%u
  ",
  			   owner_jited);
  	}

  }
  #endif

  static const struct file_operations bpf_map_fops = {

  #ifdef CONFIG_PROC_FS
  	.show_fdinfo	= bpf_map_show_fdinfo,
  #endif
  	.release	= bpf_map_release,

  };

  int bpf_map_new_fd(struct bpf_map *map)

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

  /* 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

  #define BPF_MAP_CREATE_LAST_FIELD numa_node

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

  	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);
  
  	atomic_set(&map->refcnt, 1);

  	atomic_set(&map->usercnt, 1);

  	err = bpf_map_charge_memlock(map);
  	if (err)

  		goto free_map_nouncharge;

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

  	err = bpf_map_new_fd(map);

  	if (err < 0) {
  		/* failed to allocate fd.
  		 * bpf_map_put() 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(map);
  		return err;
  	}

  	trace_bpf_map_create(map, err);

  	return err;
  
  free_map:

  	bpf_map_uncharge_memlock(map);
  free_map_nouncharge:

  	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;
  }

  /* prog's and map's refcnt limit */
  #define BPF_MAX_REFCNT 32768
  
  struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)

  {

  	if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
  		atomic_dec(&map->refcnt);
  		return ERR_PTR(-EBUSY);
  	}

  	if (uref)
  		atomic_inc(&map->usercnt);

  	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;

  	map = bpf_map_inc(map, true);

  	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 = __atomic_add_unless(&map->refcnt, 1, 0);
  
  	if (refold >= BPF_MAX_REFCNT) {
  		__bpf_map_put(map, false);
  		return ERR_PTR(-EBUSY);
  	}
  
  	if (!refold)
  		return ERR_PTR(-ENOENT);
  
  	if (uref)
  		atomic_inc(&map->usercnt);
  
  	return map;
  }

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

  /* last field in 'union bpf_attr' used by this command */
  #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
  
  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, *ptr;

  	u32 value_size;

  	struct fd f;

  	int err;
  
  	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
  		return -EINVAL;

  	f = fdget(ufd);

  	map = __bpf_map_get(f);

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

  	key = memdup_user(ukey, map->key_size);
  	if (IS_ERR(key)) {
  		err = PTR_ERR(key);

  		goto err_put;

  	}

  	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)
  		value_size = round_up(map->value_size, 8) * num_possible_cpus();

  	else if (IS_FD_MAP(map))
  		value_size = sizeof(u32);

  	else
  		value_size = map->value_size;

  	err = -ENOMEM;

  	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);

  	if (!value)

  		goto free_key;

  	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_STACK_TRACE) {
  		err = bpf_stackmap_copy(map, key, value);

  	} else if (IS_FD_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 {
  		rcu_read_lock();
  		ptr = map->ops->map_lookup_elem(map, key);
  		if (ptr)
  			memcpy(value, ptr, value_size);
  		rcu_read_unlock();
  		err = ptr ? 0 : -ENOENT;
  	}

  	if (err)

  		goto free_value;

  
  	err = -EFAULT;

  	if (copy_to_user(uvalue, value, value_size) != 0)

  		goto free_value;

  	trace_bpf_map_lookup_elem(map, ufd, key, value);

  	err = 0;

  free_value:
  	kfree(value);

  free_key:
  	kfree(key);
  err_put:
  	fdput(f);
  	return err;
  }

  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();
  }

  #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags

  
  static int map_update_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_UPDATE_ELEM))
  		return -EINVAL;

  	f = fdget(ufd);

  	map = __bpf_map_get(f);

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

  	key = memdup_user(ukey, map->key_size);
  	if (IS_ERR(key)) {
  		err = PTR_ERR(key);

  		goto err_put;

  	}

  	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)
  		value_size = round_up(map->value_size, 8) * num_possible_cpus();
  	else
  		value_size = map->value_size;

  	err = -ENOMEM;

  	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);

  	if (!value)
  		goto free_key;
  
  	err = -EFAULT;

  	if (copy_from_user(value, uvalue, value_size) != 0)

  		goto free_value;

  	/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
  	 * inside bpf map update or delete otherwise deadlocks are possible
  	 */
  	preempt_disable();
  	__this_cpu_inc(bpf_prog_active);

  	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, attr->flags);
  	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
  		err = bpf_percpu_array_update(map, key, value, attr->flags);

  	} else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY ||

  		   map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||

  		   map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY ||
  		   map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) {

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

  	} else {
  		rcu_read_lock();
  		err = map->ops->map_update_elem(map, key, value, attr->flags);
  		rcu_read_unlock();
  	}

  	__this_cpu_dec(bpf_prog_active);
  	preempt_enable();

  	maybe_wait_bpf_programs(map);

  	if (!err)
  		trace_bpf_map_update_elem(map, ufd, key, value);

  free_value:
  	kfree(value);
  free_key:
  	kfree(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);

  	key = memdup_user(ukey, map->key_size);
  	if (IS_ERR(key)) {
  		err = PTR_ERR(key);

  		goto err_put;

  	}

  	preempt_disable();
  	__this_cpu_inc(bpf_prog_active);

  	rcu_read_lock();
  	err = map->ops->map_delete_elem(map, key);
  	rcu_read_unlock();

  	__this_cpu_dec(bpf_prog_active);
  	preempt_enable();

  	maybe_wait_bpf_programs(map);

  	if (!err)
  		trace_bpf_map_delete_elem(map, ufd, key);

  	kfree(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 (ukey) {

  		key = memdup_user(ukey, map->key_size);
  		if (IS_ERR(key)) {
  			err = PTR_ERR(key);

  			goto err_put;

  		}

  	} else {
  		key = NULL;
  	}

  
  	err = -ENOMEM;
  	next_key = kmalloc(map->key_size, GFP_USER);
  	if (!next_key)
  		goto free_key;
  
  	rcu_read_lock();
  	err = map->ops->map_get_next_key(map, key, next_key);
  	rcu_read_unlock();
  	if (err)
  		goto free_next_key;
  
  	err = -EFAULT;
  	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
  		goto free_next_key;

  	trace_bpf_map_next_key(map, ufd, key, next_key);

  	err = 0;
  
  free_next_key:
  	kfree(next_key);
  free_key:
  	kfree(key);
  err_put:
  	fdput(f);
  	return err;
  }

  static const struct bpf_verifier_ops * const bpf_prog_types[] = {
  #define BPF_PROG_TYPE(_id, _ops) \
  	[_id] = &_ops,

  #define BPF_MAP_TYPE(_id, _ops)

  #include <linux/bpf_types.h>
  #undef BPF_PROG_TYPE

  #undef BPF_MAP_TYPE

  };

  
  static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
  {

  	if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
  		return -EINVAL;

  	prog->aux->ops = bpf_prog_types[type];
  	prog->type = type;
  	return 0;

  }
  
  /* drop refcnt on maps used by eBPF program and free auxilary data */
  static void free_used_maps(struct bpf_prog_aux *aux)
  {
  	int i;
  
  	for (i = 0; i < aux->used_map_cnt; i++)
  		bpf_map_put(aux->used_maps[i]);
  
  	kfree(aux->used_maps);
  }

  int __bpf_prog_charge(struct user_struct *user, u32 pages)
  {
  	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  	unsigned long user_bufs;
  
  	if (user) {
  		user_bufs = atomic_long_add_return(pages, &user->locked_vm);
  		if (user_bufs > memlock_limit) {
  			atomic_long_sub(pages, &user->locked_vm);
  			return -EPERM;
  		}
  	}
  
  	return 0;
  }
  
  void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
  {
  	if (user)
  		atomic_long_sub(pages, &user->locked_vm);
  }

  static int bpf_prog_charge_memlock(struct bpf_prog *prog)
  {
  	struct user_struct *user = get_current_user();

  	int ret;

  	ret = __bpf_prog_charge(user, prog->pages);
  	if (ret) {

  		free_uid(user);

  		return ret;

  	}

  	prog->aux->user = user;
  	return 0;
  }
  
  static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
  {
  	struct user_struct *user = prog->aux->user;

  	__bpf_prog_uncharge(user, prog->pages);

  	free_uid(user);
  }

  static int bpf_prog_alloc_id(struct bpf_prog *prog)
  {
  	int id;
  
  	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);
  
  	/* id is in [1, INT_MAX) */
  	if (WARN_ON_ONCE(!id))
  		return -ENOSPC;
  
  	return id > 0 ? 0 : id;
  }

  static void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)

  {
  	/* cBPF to eBPF migrations are currently not in the idr store. */
  	if (!prog->aux->id)
  		return;

  	if (do_idr_lock)
  		spin_lock_bh(&prog_idr_lock);
  	else
  		__acquire(&prog_idr_lock);

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

  
  	if (do_idr_lock)
  		spin_unlock_bh(&prog_idr_lock);
  	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);
  
  	free_used_maps(aux);

  	bpf_prog_uncharge_memlock(aux->prog);

  	bpf_prog_free(aux->prog);
  }

  static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)

  {

  	if (atomic_dec_and_test(&prog->aux->refcnt)) {
  		trace_bpf_prog_put_rcu(prog);

  		/* bpf_prog_free_id() must be called first */

  		bpf_prog_free_id(prog, do_idr_lock);

  		bpf_prog_kallsyms_del(prog);

  		call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);

  	}

  }

  
  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;
  }

  #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] = { };

  	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));

  	seq_printf(m,
  		   "prog_type:\t%u
  "
  		   "prog_jited:\t%u
  "

  		   "prog_tag:\t%s
  "

  		   "memlock:\t%llu
  ",
  		   prog->type,
  		   prog->jited,

  		   prog_tag,

  		   prog->pages * 1ULL << PAGE_SHIFT);
  }
  #endif

  static const struct file_operations bpf_prog_fops = {

  #ifdef CONFIG_PROC_FS
  	.show_fdinfo	= bpf_prog_show_fdinfo,
  #endif
  	.release	= bpf_prog_release,

  };

  int bpf_prog_new_fd(struct bpf_prog *prog)

  {
  	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;

  }

  struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)

  {

  	if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
  		atomic_sub(i, &prog->aux->refcnt);

  		return ERR_PTR(-EBUSY);
  	}
  	return prog;
  }

  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(atomic_sub_return(i, &prog->aux->refcnt) == 0);
  }
  EXPORT_SYMBOL_GPL(bpf_prog_sub);

  struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
  {
  	return bpf_prog_add(prog, 1);
  }

  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 = __atomic_add_unless(&prog->aux->refcnt, 1, 0);
  
  	if (refold >= BPF_MAX_REFCNT) {
  		__bpf_prog_put(prog, false);
  		return ERR_PTR(-EBUSY);
  	}
  
  	if (!refold)
  		return ERR_PTR(-ENOENT);
  
  	return prog;
  }

  EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);

  static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type)

  {
  	struct fd f = fdget(ufd);
  	struct bpf_prog *prog;

  	prog = ____bpf_prog_get(f);

  	if (IS_ERR(prog))
  		return prog;

  	if (type && prog->type != *type) {
  		prog = ERR_PTR(-EINVAL);
  		goto out;
  	}

  	prog = bpf_prog_inc(prog);

  out:

  	fdput(f);
  	return prog;
  }

  
  struct bpf_prog *bpf_prog_get(u32 ufd)
  {
  	return __bpf_prog_get(ufd, NULL);
  }
  
  struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type)
  {

  	struct bpf_prog *prog = __bpf_prog_get(ufd, &type);
  
  	if (!IS_ERR(prog))
  		trace_bpf_prog_get_type(prog);
  	return prog;

  }
  EXPORT_SYMBOL_GPL(bpf_prog_get_type);

  
  /* last field in 'union bpf_attr' used by this command */

  #define	BPF_PROG_LOAD_LAST_FIELD prog_flags

  
  static int bpf_prog_load(union bpf_attr *attr)
  {
  	enum bpf_prog_type type = attr->prog_type;
  	struct bpf_prog *prog;
  	int err;
  	char license[128];
  	bool is_gpl;
  
  	if (CHECK_ATTR(BPF_PROG_LOAD))
  		return -EINVAL;

  	if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
  		return -EINVAL;

  	/* copy eBPF program license from user space */

  	if (strncpy_from_user(license, u64_to_user_ptr(attr->license),

  			      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_MAXINSNS)
  		return -E2BIG;

  	if (type == BPF_PROG_TYPE_KPROBE &&
  	    attr->kern_version != LINUX_VERSION_CODE)
  		return -EINVAL;

  	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
  	    type != BPF_PROG_TYPE_CGROUP_SKB &&
  	    !capable(CAP_SYS_ADMIN))

  		return -EPERM;

  	/* plain bpf_prog allocation */
  	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
  	if (!prog)
  		return -ENOMEM;

  	err = bpf_prog_charge_memlock(prog);
  	if (err)
  		goto free_prog_nouncharge;

  	prog->len = attr->insn_cnt;
  
  	err = -EFAULT;

  	if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),

  			   bpf_prog_insn_size(prog)) != 0)

  		goto free_prog;
  
  	prog->orig_prog = NULL;

  	prog->jited = 0;

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

  	prog->gpl_compatible = is_gpl ? 1 : 0;

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

  	err = bpf_check(&prog, attr);

  	if (err < 0)
  		goto free_used_maps;
  
  	/* eBPF program is ready to be JITed */

  	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;

  	err = bpf_prog_new_fd(prog);

  	if (err < 0) {
  		/* failed to allocate fd.
  		 * bpf_prog_put() is needed because the above
  		 * bpf_prog_alloc_id() has published the prog
  		 * to the userspace and the userspace may
  		 * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
  		 */
  		bpf_prog_put(prog);
  		return err;
  	}

  	bpf_prog_kallsyms_add(prog);

  	trace_bpf_prog_load(prog, err);

  	return err;
  
  free_used_maps:
  	free_used_maps(prog->aux);
  free_prog:

  	bpf_prog_uncharge_memlock(prog);
  free_prog_nouncharge:

  	bpf_prog_free(prog);
  	return err;
  }

  #define BPF_OBJ_LAST_FIELD bpf_fd
  
  static int bpf_obj_pin(const union bpf_attr *attr)
  {
  	if (CHECK_ATTR(BPF_OBJ))
  		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)
  		return -EINVAL;

  	return bpf_obj_get_user(u64_to_user_ptr(attr->pathname));

  }

  #ifdef CONFIG_CGROUP_BPF

  #define BPF_PROG_ATTACH_LAST_FIELD attach_flags

  static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach)

  {

  	struct bpf_prog *prog = NULL;

  	int ufd = attr->target_fd;
  	struct bpf_map *map;
  	struct fd f;
  	int err;
  
  	f = fdget(ufd);
  	map = __bpf_map_get(f);
  	if (IS_ERR(map))
  		return PTR_ERR(map);

  	if (attach) {
  		prog = bpf_prog_get_type(attr->attach_bpf_fd,
  					 BPF_PROG_TYPE_SK_SKB);
  		if (IS_ERR(prog)) {
  			fdput(f);
  			return PTR_ERR(prog);
  		}

  	}

  	err = sock_map_prog(map, prog, attr->attach_type);

  	if (err) {
  		fdput(f);

  		if (prog)
  			bpf_prog_put(prog);

  		return err;

  	}
  
  	fdput(f);

  	return 0;

  }

  
  static int bpf_prog_attach(const union bpf_attr *attr)
  {

  	enum bpf_prog_type ptype;

  	struct bpf_prog *prog;
  	struct cgroup *cgrp;

  	int ret;

  
  	if (!capable(CAP_NET_ADMIN))
  		return -EPERM;
  
  	if (CHECK_ATTR(BPF_PROG_ATTACH))
  		return -EINVAL;

  	if (attr->attach_flags & ~BPF_F_ALLOW_OVERRIDE)
  		return -EINVAL;

  	switch (attr->attach_type) {
  	case BPF_CGROUP_INET_INGRESS:
  	case BPF_CGROUP_INET_EGRESS:

  		ptype = BPF_PROG_TYPE_CGROUP_SKB;

  		break;

  	case BPF_CGROUP_INET_SOCK_CREATE:
  		ptype = BPF_PROG_TYPE_CGROUP_SOCK;
  		break;

  	case BPF_CGROUP_SOCK_OPS:
  		ptype = BPF_PROG_TYPE_SOCK_OPS;
  		break;

  	case BPF_SK_SKB_STREAM_PARSER:
  	case BPF_SK_SKB_STREAM_VERDICT:

  		return sockmap_get_from_fd(attr, true);

  	default:
  		return -EINVAL;
  	}

  	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
  	if (IS_ERR(prog))
  		return PTR_ERR(prog);
  
  	cgrp = cgroup_get_from_fd(attr->target_fd);
  	if (IS_ERR(cgrp)) {
  		bpf_prog_put(prog);
  		return PTR_ERR(cgrp);
  	}

  	ret = cgroup_bpf_update(cgrp, prog, attr->attach_type,
  				attr->attach_flags & BPF_F_ALLOW_OVERRIDE);
  	if (ret)
  		bpf_prog_put(prog);

  	cgroup_put(cgrp);

  	return ret;

  }
  
  #define BPF_PROG_DETACH_LAST_FIELD attach_type
  
  static int bpf_prog_detach(const union bpf_attr *attr)
  {
  	struct cgroup *cgrp;

  	int ret;

  
  	if (!capable(CAP_NET_ADMIN))
  		return -EPERM;
  
  	if (CHECK_ATTR(BPF_PROG_DETACH))
  		return -EINVAL;
  
  	switch (attr->attach_type) {
  	case BPF_CGROUP_INET_INGRESS:
  	case BPF_CGROUP_INET_EGRESS:

  	case BPF_CGROUP_INET_SOCK_CREATE:

  	case BPF_CGROUP_SOCK_OPS:

  		cgrp = cgroup_get_from_fd(attr->target_fd);
  		if (IS_ERR(cgrp))
  			return PTR_ERR(cgrp);

  		ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false);

  		cgroup_put(cgrp);
  		break;

  	case BPF_SK_SKB_STREAM_PARSER:
  	case BPF_SK_SKB_STREAM_VERDICT:
  		ret = sockmap_get_from_fd(attr, false);
  		break;

  	default:
  		return -EINVAL;
  	}

  	return ret;

  }

  #endif /* CONFIG_CGROUP_BPF */

  #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
  
  static int bpf_prog_test_run(const union bpf_attr *attr,
  			     union bpf_attr __user *uattr)
  {
  	struct bpf_prog *prog;
  	int ret = -ENOTSUPP;
  
  	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
  		return -EINVAL;
  
  	prog = bpf_prog_get(attr->test.prog_fd);
  	if (IS_ERR(prog))
  		return PTR_ERR(prog);
  
  	if (prog->aux->ops->test_run)
  		ret = prog->aux->ops->test_run(prog, attr, uattr);
  
  	bpf_prog_put(prog);
  	return ret;
  }

  #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
  
  static int bpf_obj_get_next_id(const union bpf_attr *attr,
  			       union bpf_attr __user *uattr,
  			       struct idr *idr,
  			       spinlock_t *lock)
  {
  	u32 next_id = attr->start_id;
  	int err = 0;
  
  	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
  		return -EINVAL;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	next_id++;
  	spin_lock_bh(lock);
  	if (!idr_get_next(idr, &next_id))
  		err = -ENOENT;
  	spin_unlock_bh(lock);
  
  	if (!err)
  		err = put_user(next_id, &uattr->next_id);
  
  	return err;
  }

  #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
  
  static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
  {
  	struct bpf_prog *prog;
  	u32 id = attr->prog_id;
  	int fd;
  
  	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
  		return -EINVAL;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	spin_lock_bh(&prog_idr_lock);
  	prog = idr_find(&prog_idr, id);
  	if (prog)
  		prog = bpf_prog_inc_not_zero(prog);
  	else
  		prog = ERR_PTR(-ENOENT);
  	spin_unlock_bh(&prog_idr_lock);
  
  	if (IS_ERR(prog))
  		return PTR_ERR(prog);
  
  	fd = bpf_prog_new_fd(prog);
  	if (fd < 0)
  		bpf_prog_put(prog);
  
  	return fd;
  }

  #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD map_id
  
  static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
  {
  	struct bpf_map *map;
  	u32 id = attr->map_id;
  	int fd;
  
  	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID))
  		return -EINVAL;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	spin_lock_bh(&map_idr_lock);
  	map = idr_find(&map_idr, id);
  	if (map)
  		map = bpf_map_inc_not_zero(map, true);
  	else
  		map = ERR_PTR(-ENOENT);
  	spin_unlock_bh(&map_idr_lock);
  
  	if (IS_ERR(map))
  		return PTR_ERR(map);
  
  	fd = bpf_map_new_fd(map);
  	if (fd < 0)
  		bpf_map_put(map);
  
  	return fd;
  }

  static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
  				   const union bpf_attr *attr,
  				   union bpf_attr __user *uattr)
  {
  	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
  	struct bpf_prog_info info = {};
  	u32 info_len = attr->info.info_len;
  	char __user *uinsns;
  	u32 ulen;
  	int err;
  
  	err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
  	if (err)
  		return err;
  	info_len = min_t(u32, sizeof(info), info_len);
  
  	if (copy_from_user(&info, uinfo, info_len))

  		return -EFAULT;

  
  	info.type = prog->type;
  	info.id = prog->aux->id;
  
  	memcpy(info.tag, prog->tag, sizeof(prog->tag));
  
  	if (!capable(CAP_SYS_ADMIN)) {
  		info.jited_prog_len = 0;
  		info.xlated_prog_len = 0;
  		goto done;
  	}
  
  	ulen = info.jited_prog_len;
  	info.jited_prog_len = prog->jited_len;
  	if (info.jited_prog_len && ulen) {
  		uinsns = u64_to_user_ptr(info.jited_prog_insns);
  		ulen = min_t(u32, info.jited_prog_len, ulen);
  		if (copy_to_user(uinsns, prog->bpf_func, ulen))
  			return -EFAULT;
  	}
  
  	ulen = info.xlated_prog_len;

  	info.xlated_prog_len = bpf_prog_insn_size(prog);

  	if (info.xlated_prog_len && ulen) {
  		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
  		ulen = min_t(u32, info.xlated_prog_len, ulen);
  		if (copy_to_user(uinsns, prog->insnsi, ulen))
  			return -EFAULT;
  	}
  
  done:
  	if (copy_to_user(uinfo, &info, info_len) ||
  	    put_user(info_len, &uattr->info.info_len))
  		return -EFAULT;
  
  	return 0;
  }
  
  static int bpf_map_get_info_by_fd(struct bpf_map *map,
  				  const union bpf_attr *attr,
  				  union bpf_attr __user *uattr)
  {
  	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
  	struct bpf_map_info info = {};
  	u32 info_len = attr->info.info_len;
  	int err;
  
  	err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
  	if (err)
  		return err;
  	info_len = min_t(u32, sizeof(info), info_len);
  
  	info.type = map->map_type;
  	info.id = map->id;
  	info.key_size = map->key_size;
  	info.value_size = map->value_size;
  	info.max_entries = map->max_entries;
  	info.map_flags = map->map_flags;
  
  	if (copy_to_user(uinfo, &info, info_len) ||
  	    put_user(info_len, &uattr->info.info_len))
  		return -EFAULT;
  
  	return 0;
  }
  
  #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
  
  static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
  				  union bpf_attr __user *uattr)
  {
  	int ufd = attr->info.bpf_fd;
  	struct fd f;
  	int err;
  
  	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
  		return -EINVAL;
  
  	f = fdget(ufd);
  	if (!f.file)
  		return -EBADFD;
  
  	if (f.file->f_op == &bpf_prog_fops)
  		err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
  					      uattr);
  	else if (f.file->f_op == &bpf_map_fops)
  		err = bpf_map_get_info_by_fd(f.file->private_data, attr,
  					     uattr);
  	else
  		err = -EINVAL;
  
  	fdput(f);
  	return err;
  }

  SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
  {
  	union bpf_attr attr = {};
  	int err;

  	if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))

  		return -EPERM;

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

  
  	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
  	if (copy_from_user(&attr, uattr, size) != 0)
  		return -EFAULT;
  
  	switch (cmd) {
  	case BPF_MAP_CREATE:
  		err = map_create(&attr);
  		break;

  	case BPF_MAP_LOOKUP_ELEM:
  		err = map_lookup_elem(&attr);
  		break;
  	case BPF_MAP_UPDATE_ELEM:
  		err = map_update_elem(&attr);
  		break;
  	case BPF_MAP_DELETE_ELEM:
  		err = map_delete_elem(&attr);
  		break;
  	case BPF_MAP_GET_NEXT_KEY:
  		err = map_get_next_key(&attr);
  		break;

  	case BPF_PROG_LOAD:
  		err = bpf_prog_load(&attr);
  		break;

  	case BPF_OBJ_PIN:
  		err = bpf_obj_pin(&attr);
  		break;
  	case BPF_OBJ_GET:
  		err = bpf_obj_get(&attr);
  		break;

  #ifdef CONFIG_CGROUP_BPF
  	case BPF_PROG_ATTACH:
  		err = bpf_prog_attach(&attr);
  		break;
  	case BPF_PROG_DETACH:
  		err = bpf_prog_detach(&attr);
  		break;
  #endif

  	case BPF_PROG_TEST_RUN:
  		err = bpf_prog_test_run(&attr, uattr);
  		break;

  	case BPF_PROG_GET_NEXT_ID:
  		err = bpf_obj_get_next_id(&attr, uattr,
  					  &prog_idr, &prog_idr_lock);
  		break;
  	case BPF_MAP_GET_NEXT_ID:
  		err = bpf_obj_get_next_id(&attr, uattr,
  					  &map_idr, &map_idr_lock);
  		break;

  	case BPF_PROG_GET_FD_BY_ID:
  		err = bpf_prog_get_fd_by_id(&attr);
  		break;

  	case BPF_MAP_GET_FD_BY_ID:
  		err = bpf_map_get_fd_by_id(&attr);
  		break;

  	case BPF_OBJ_GET_INFO_BY_FD:
  		err = bpf_obj_get_info_by_fd(&attr, uattr);
  		break;

  	default:
  		err = -EINVAL;
  		break;
  	}
  
  	return err;
  }