text: /* 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/bpf_lirc.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/version.h>
  #include <linux/kernel.h>
  #include <linux/idr.h>
  #include <linux/cred.h>
  #include <linux/timekeeping.h>
  #include <linux/ctype.h>
  #include <linux/btf.h>
  #include <linux/nospec.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 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);
  
  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.
   */
  int bpf_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;
  }
  
  const struct bpf_map_ops bpf_map_offload_ops = {
  	.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;
  }
  
  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);
  }
  
  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 = attr->map_flags;
  	map->numa_node = bpf_map_attr_numa_node(attr);
  }
  
  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_charge_memlock(struct user_struct *user, u32 pages)
  {
  	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  
  	if (atomic_long_add_return(pages, &user->locked_vm) > memlock_limit) {
  		atomic_long_sub(pages, &user->locked_vm);
  		return -EPERM;
  	}
  	return 0;
  }
  
  static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
  {
  	atomic_long_sub(pages, &user->locked_vm);
  }
  
  static int bpf_map_init_memlock(struct bpf_map *map)
  {
  	struct user_struct *user = get_current_user();
  	int ret;
  
  	ret = bpf_charge_memlock(user, map->pages);
  	if (ret) {
  		free_uid(user);
  		return ret;
  	}
  	map->user = user;
  	return ret;
  }
  
  static void bpf_map_release_memlock(struct bpf_map *map)
  {
  	struct user_struct *user = map->user;
  	bpf_uncharge_memlock(user, map->pages);
  	free_uid(user);
  }
  
  int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
  {
  	int ret;
  
  	ret = bpf_charge_memlock(map->user, pages);
  	if (ret)
  		return ret;
  	map->pages += pages;
  	return ret;
  }
  
  void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
  {
  	bpf_uncharge_memlock(map->user, pages);
  	map->pages -= pages;
  }
  
  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);
  }
  
  /* 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_release_memlock(map);
  	security_bpf_map_free(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);
  		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;
  }
  
  #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\n"
  		   "key_size:\t%u\n"
  		   "value_size:\t%u\n"
  		   "max_entries:\t%u\n"
  		   "map_flags:\t%#x\n"
  		   "memlock:\t%llu\n"
  		   "map_id:\t%u\n",
  		   map->map_type,
  		   map->key_size,
  		   map->value_size,
  		   map->max_entries,
  		   map->map_flags,
  		   map->pages * 1ULL << PAGE_SHIFT,
  		   map->id);
  
  	if (owner_prog_type) {
  		seq_printf(m, "owner_prog_type:\t%u\n",
  			   owner_prog_type);
  		seq_printf(m, "owner_jited:\t%u\n",
  			   owner_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;
  }
  
  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,
  };
  
  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 BPF_OBJ_NAME_LEN number of bytes.
   * Return 0 on success and < 0 on error.
   */
  static int bpf_obj_name_cpy(char *dst, const char *src)
  {
  	const char *end = src + BPF_OBJ_NAME_LEN;
  
  	memset(dst, 0, BPF_OBJ_NAME_LEN);
  
  	/* Copy all isalnum() and '_' char */
  	while (src < end && *src) {
  		if (!isalnum(*src) && *src != '_')
  			return -EINVAL;
  		*dst++ = *src++;
  	}
  
  	/* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */
  	if (src == end)
  		return -EINVAL;
  
  	return 0;
  }
  
  int map_check_no_btf(const struct bpf_map *map,
  		     const struct btf_type *key_type,
  		     const struct btf_type *value_type)
  {
  	return -ENOTSUPP;
  }
  
  static int map_check_btf(const 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;
  
  	key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
  	if (!key_type || key_size != map->key_size)
  		return -EINVAL;
  
  	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
  	if (!value_type || value_size != map->value_size)
  		return -EINVAL;
  
  	if (map->ops->map_check_btf)
  		ret = map->ops->map_check_btf(map, key_type, value_type);
  
  	return ret;
  }
  
  #define BPF_MAP_CREATE_LAST_FIELD btf_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;
  
  	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);
  	if (err)
  		goto free_map_nouncharge;
  
  	atomic_set(&map->refcnt, 1);
  	atomic_set(&map->usercnt, 1);
  
  	if (attr->btf_key_type_id || attr->btf_value_type_id) {
  		struct btf *btf;
  
  		if (!attr->btf_key_type_id || !attr->btf_value_type_id) {
  			err = -EINVAL;
  			goto free_map_nouncharge;
  		}
  
  		btf = btf_get_by_fd(attr->btf_fd);
  		if (IS_ERR(btf)) {
  			err = PTR_ERR(btf);
  			goto free_map_nouncharge;
  		}
  
  		err = map_check_btf(map, btf, attr->btf_key_type_id,
  				    attr->btf_value_type_id);
  		if (err) {
  			btf_put(btf);
  			goto free_map_nouncharge;
  		}
  
  		map->btf = btf;
  		map->btf_key_type_id = attr->btf_key_type_id;
  		map->btf_value_type_id = attr->btf_value_type_id;
  	}
  
  	err = security_bpf_map_alloc(map);
  	if (err)
  		goto free_map_nouncharge;
  
  	err = bpf_map_init_memlock(map);
  	if (err)
  		goto free_map_sec;
  
  	err = bpf_map_alloc_id(map);
  	if (err)
  		goto free_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:
  	bpf_map_release_memlock(map);
  free_map_sec:
  	security_bpf_map_free(map);
  free_map_nouncharge:
  	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;
  }
  
  /* 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;
  }
  EXPORT_SYMBOL_GPL(bpf_map_inc);
  
  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_fetch_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);
  
  	if (!(f.file->f_mode & FMODE_CAN_READ)) {
  		err = -EPERM;
  		goto err_put;
  	}
  
  	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 (bpf_map_is_dev_bound(map)) {
  		err = bpf_map_offload_lookup_elem(map, key, value);
  		goto done;
  	}
  
  	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_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 if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
  		err = bpf_fd_reuseport_array_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 (ptr)
  			memcpy(value, ptr, value_size);
  		rcu_read_unlock();
  		err = ptr ? 0 : -ENOENT;
  	}
  	this_cpu_dec(bpf_prog_active);
  	preempt_enable();
  
  done:
  	if (err)
  		goto free_value;
  
  	err = -EFAULT;
  	if (copy_to_user(uvalue, value, value_size) != 0)
  		goto free_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);
  
  	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
  		err = -EPERM;
  		goto err_put;
  	}
  
  	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;
  
  	/* Need to create a kthread, thus must support schedule */
  	if (bpf_map_is_dev_bound(map)) {
  		err = bpf_map_offload_update_elem(map, key, value, attr->flags);
  		goto out;
  	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
  		   map->map_type == BPF_MAP_TYPE_SOCKHASH ||
  		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
  		err = map->ops->map_update_elem(map, key, value, attr->flags);
  		goto out;
  	}
  
  	/* 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 (IS_FD_ARRAY(map)) {
  		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 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,
  							 attr->flags);
  	} 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);
  out:
  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);
  
  	if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
  		err = -EPERM;
  		goto err_put;
  	}
  
  	key = memdup_user(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;
  	}
  
  	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);
  out:
  	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 (!(f.file->f_mode & FMODE_CAN_READ)) {
  		err = -EPERM;
  		goto err_put;
  	}
  
  	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;
  
  	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:
  	kfree(next_key);
  free_key:
  	kfree(key);
  err_put:
  	fdput(f);
  	return err;
  }
  
  static const struct bpf_prog_ops * const bpf_prog_types[] = {
  #define BPF_PROG_TYPE(_id, _name) \
  	[_id] = & _name ## _prog_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)
  {
  	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;
  }
  
  /* drop refcnt on maps used by eBPF program and free auxilary data */
  static void free_used_maps(struct bpf_prog_aux *aux)
  {
  	int i;
  
  	if (aux->cgroup_storage)
  		bpf_cgroup_storage_release(aux->prog, aux->cgroup_storage);
  
  	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;
  
  	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)
  {
  	/* 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_bh(&prog_idr_lock);
  	else
  		__acquire(&prog_idr_lock);
  
  	idr_remove(&prog_idr, prog->aux->id);
  	prog->aux->id = 0;
  
  	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);
  	security_bpf_prog_free(aux);
  	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)) {
  		/* bpf_prog_free_id() must be called first */
  		bpf_prog_free_id(prog, do_idr_lock);
  		bpf_prog_kallsyms_del_all(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\n"
  		   "prog_jited:\t%u\n"
  		   "prog_tag:\t%s\n"
  		   "memlock:\t%llu\n"
  		   "prog_id:\t%u\n",
  		   prog->type,
  		   prog->jited,
  		   prog_tag,
  		   prog->pages * 1ULL << PAGE_SHIFT,
  		   prog->aux->id);
  }
  #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;
  }
  
  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_fetch_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);
  
  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;
  	}
  
  	prog = 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;
  	}
  }
  
  static int
  bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
  				enum bpf_attach_type expected_attach_type)
  {
  	switch (prog_type) {
  	case BPF_PROG_TYPE_CGROUP_SOCK:
  		switch (expected_attach_type) {
  		case BPF_CGROUP_INET_SOCK_CREATE:
  		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_UDP4_SENDMSG:
  		case BPF_CGROUP_UDP6_SENDMSG:
  		case BPF_CGROUP_UDP4_RECVMSG:
  		case BPF_CGROUP_UDP6_RECVMSG:
  			return 0;
  		default:
  			return -EINVAL;
  		}
  	default:
  		return 0;
  	}
  }
  
  /* last field in 'union bpf_attr' used by this command */
  #define	BPF_PROG_LOAD_LAST_FIELD expected_attach_type
  
  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;
  
  	bpf_prog_load_fixup_attach_type(attr);
  	if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type))
  		return -EINVAL;
  
  	/* plain bpf_prog allocation */
  	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
  	if (!prog)
  		return -ENOMEM;
  
  	prog->expected_attach_type = attr->expected_attach_type;
  
  	prog->aux->offload_requested = !!attr->prog_ifindex;
  
  	err = security_bpf_prog_alloc(prog->aux);
  	if (err)
  		goto free_prog_nouncharge;
  
  	err = bpf_prog_charge_memlock(prog);
  	if (err)
  		goto free_prog_sec;
  
  	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;
  
  	if (bpf_prog_is_dev_bound(prog->aux)) {
  		err = bpf_prog_offload_init(prog, attr);
  		if (err)
  			goto free_prog;
  	}
  
  	/* find program type: socket_filter vs tracing_filter */
  	err = find_prog_type(type, prog);
  	if (err < 0)
  		goto free_prog;
  
  	prog->aux->load_time = ktime_get_boot_ns();
  	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
  	if (err)
  		goto free_prog;
  
  	/* run eBPF verifier */
  	err = bpf_check(&prog, attr);
  	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);
  
  	err = bpf_prog_new_fd(prog);
  	if (err < 0)
  		bpf_prog_put(prog);
  	return err;
  
  free_used_maps:
  	bpf_prog_kallsyms_del_subprogs(prog);
  	free_used_maps(prog->aux);
  free_prog:
  	bpf_prog_uncharge_memlock(prog);
  free_prog_sec:
  	security_bpf_prog_free(prog->aux);
  free_prog_nouncharge:
  	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);
  }
  
  struct bpf_raw_tracepoint {
  	struct bpf_raw_event_map *btp;
  	struct bpf_prog *prog;
  };
  
  static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp)
  {
  	struct bpf_raw_tracepoint *raw_tp = filp->private_data;
  
  	if (raw_tp->prog) {
  		bpf_probe_unregister(raw_tp->btp, raw_tp->prog);
  		bpf_prog_put(raw_tp->prog);
  	}
  	kfree(raw_tp);
  	return 0;
  }
  
  static const struct file_operations bpf_raw_tp_fops = {
  	.release	= bpf_raw_tracepoint_release,
  	.read		= bpf_dummy_read,
  	.write		= bpf_dummy_write,
  };
  
  #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
  
  static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
  {
  	struct bpf_raw_tracepoint *raw_tp;
  	struct bpf_raw_event_map *btp;
  	struct bpf_prog *prog;
  	char tp_name[128];
  	int tp_fd, err;
  
  	if (strncpy_from_user(tp_name, u64_to_user_ptr(attr->raw_tracepoint.name),
  			      sizeof(tp_name) - 1) < 0)
  		return -EFAULT;
  	tp_name[sizeof(tp_name) - 1] = 0;
  
  	btp = bpf_find_raw_tracepoint(tp_name);
  	if (!btp)
  		return -ENOENT;
  
  	raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER);
  	if (!raw_tp)
  		return -ENOMEM;
  	raw_tp->btp = btp;
  
  	prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd,
  				 BPF_PROG_TYPE_RAW_TRACEPOINT);
  	if (IS_ERR(prog)) {
  		err = PTR_ERR(prog);
  		goto out_free_tp;
  	}
  
  	err = bpf_probe_register(raw_tp->btp, prog);
  	if (err)
  		goto out_put_prog;
  
  	raw_tp->prog = prog;
  	tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp,
  				 O_CLOEXEC);
  	if (tp_fd < 0) {
  		bpf_probe_unregister(raw_tp->btp, prog);
  		err = tp_fd;
  		goto out_put_prog;
  	}
  	return tp_fd;
  
  out_put_prog:
  	bpf_prog_put(prog);
  out_free_tp:
  	kfree(raw_tp);
  	return err;
  }
  
  static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
  					     enum bpf_attach_type attach_type)
  {
  	switch (prog->type) {
  	case BPF_PROG_TYPE_CGROUP_SOCK:
  	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
  		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
  	default:
  		return 0;
  	}
  }
  
  #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
  
  #define BPF_F_ATTACH_MASK \
  	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
  
  static int bpf_prog_attach(const union bpf_attr *attr)
  {
  	enum bpf_prog_type ptype;
  	struct bpf_prog *prog;
  	int ret;
  
  	if (!capable(CAP_NET_ADMIN))
  		return -EPERM;
  
  	if (CHECK_ATTR(BPF_PROG_ATTACH))
  		return -EINVAL;
  
  	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
  		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:
  	case BPF_CGROUP_INET4_POST_BIND:
  	case BPF_CGROUP_INET6_POST_BIND:
  		ptype = BPF_PROG_TYPE_CGROUP_SOCK;
  		break;
  	case BPF_CGROUP_INET4_BIND:
  	case BPF_CGROUP_INET6_BIND:
  	case BPF_CGROUP_INET4_CONNECT:
  	case BPF_CGROUP_INET6_CONNECT:
  	case BPF_CGROUP_UDP4_SENDMSG:
  	case BPF_CGROUP_UDP6_SENDMSG:
  	case BPF_CGROUP_UDP4_RECVMSG:
  	case BPF_CGROUP_UDP6_RECVMSG:
  		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
  		break;
  	case BPF_CGROUP_SOCK_OPS:
  		ptype = BPF_PROG_TYPE_SOCK_OPS;
  		break;
  	case BPF_CGROUP_DEVICE:
  		ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
  		break;
  	case BPF_SK_MSG_VERDICT:
  		ptype = BPF_PROG_TYPE_SK_MSG;
  		break;
  	case BPF_SK_SKB_STREAM_PARSER:
  	case BPF_SK_SKB_STREAM_VERDICT:
  		ptype = BPF_PROG_TYPE_SK_SKB;
  		break;
  	case BPF_LIRC_MODE2:
  		ptype = BPF_PROG_TYPE_LIRC_MODE2;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
  	if (IS_ERR(prog))
  		return PTR_ERR(prog);
  
  	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
  		bpf_prog_put(prog);
  		return -EINVAL;
  	}
  
  	switch (ptype) {
  	case BPF_PROG_TYPE_SK_SKB:
  	case BPF_PROG_TYPE_SK_MSG:
  		ret = sockmap_get_from_fd(attr, ptype, prog);
  		break;
  	case BPF_PROG_TYPE_LIRC_MODE2:
  		ret = lirc_prog_attach(attr, prog);
  		break;
  	default:
  		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
  	}
  
  	if (ret)
  		bpf_prog_put(prog);
  	return ret;
  }
  
  #define BPF_PROG_DETACH_LAST_FIELD attach_type
  
  static int bpf_prog_detach(const union bpf_attr *attr)
  {
  	enum bpf_prog_type ptype;
  
  	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:
  		ptype = BPF_PROG_TYPE_CGROUP_SKB;
  		break;
  	case BPF_CGROUP_INET_SOCK_CREATE:
  	case BPF_CGROUP_INET4_POST_BIND:
  	case BPF_CGROUP_INET6_POST_BIND:
  		ptype = BPF_PROG_TYPE_CGROUP_SOCK;
  		break;
  	case BPF_CGROUP_INET4_BIND:
  	case BPF_CGROUP_INET6_BIND:
  	case BPF_CGROUP_INET4_CONNECT:
  	case BPF_CGROUP_INET6_CONNECT:
  	case BPF_CGROUP_UDP4_SENDMSG:
  	case BPF_CGROUP_UDP6_SENDMSG:
  	case BPF_CGROUP_UDP4_RECVMSG:
  	case BPF_CGROUP_UDP6_RECVMSG:
  		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
  		break;
  	case BPF_CGROUP_SOCK_OPS:
  		ptype = BPF_PROG_TYPE_SOCK_OPS;
  		break;
  	case BPF_CGROUP_DEVICE:
  		ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
  		break;
  	case BPF_SK_MSG_VERDICT:
  		return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, NULL);
  	case BPF_SK_SKB_STREAM_PARSER:
  	case BPF_SK_SKB_STREAM_VERDICT:
  		return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, NULL);
  	case BPF_LIRC_MODE2:
  		return lirc_prog_detach(attr);
  	default:
  		return -EINVAL;
  	}
  
  	return cgroup_bpf_prog_detach(attr, ptype);
  }
  
  #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
  
  static int bpf_prog_query(const union bpf_attr *attr,
  			  union bpf_attr __user *uattr)
  {
  	if (!capable(CAP_NET_ADMIN))
  		return -EPERM;
  	if (CHECK_ATTR(BPF_PROG_QUERY))
  		return -EINVAL;
  	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
  		return -EINVAL;
  
  	switch (attr->query.attach_type) {
  	case BPF_CGROUP_INET_INGRESS:
  	case BPF_CGROUP_INET_EGRESS:
  	case BPF_CGROUP_INET_SOCK_CREATE:
  	case BPF_CGROUP_INET4_BIND:
  	case BPF_CGROUP_INET6_BIND:
  	case BPF_CGROUP_INET4_POST_BIND:
  	case BPF_CGROUP_INET6_POST_BIND:
  	case BPF_CGROUP_INET4_CONNECT:
  	case BPF_CGROUP_INET6_CONNECT:
  	case BPF_CGROUP_UDP4_SENDMSG:
  	case BPF_CGROUP_UDP6_SENDMSG:
  	case BPF_CGROUP_UDP4_RECVMSG:
  	case BPF_CGROUP_UDP6_RECVMSG:
  	case BPF_CGROUP_SOCK_OPS:
  	case BPF_CGROUP_DEVICE:
  		break;
  	case BPF_LIRC_MODE2:
  		return lirc_prog_query(attr, uattr);
  	default:
  		return -EINVAL;
  	}
  
  	return cgroup_bpf_prog_query(attr, uattr);
  }
  
  #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 (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  	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 open_flags
  
  static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
  {
  	struct bpf_map *map;
  	u32 id = attr->map_id;
  	int f_flags;
  	int fd;
  
  	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
  	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
  		return -EINVAL;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	f_flags = bpf_get_file_flag(attr->open_flags);
  	if (f_flags < 0)
  		return f_flags;
  
  	spin_lock_bh(&map_idr_lock);
  	map = idr_find(&map_idr, id);
  	if (map)
  		map = bpf_map_inc_not_zero(map, true);
  	else
  		map = ERR_PTR(-ENOENT);
  	spin_unlock_bh(&map_idr_lock);
  
  	if (IS_ERR(map))
  		return PTR_ERR(map);
  
  	fd = bpf_map_new_fd(map, f_flags);
  	if (fd < 0)
  		bpf_map_put_with_uref(map);
  
  	return fd;
  }
  
  static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
  					      unsigned long addr)
  {
  	int i;
  
  	for (i = 0; i < prog->aux->used_map_cnt; i++)
  		if (prog->aux->used_maps[i] == (void *)addr)
  			return prog->aux->used_maps[i];
  	return NULL;
  }
  
  static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
  {
  	const struct bpf_map *map;
  	struct bpf_insn *insns;
  	u64 imm;
  	int i;
  
  	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
  			GFP_USER);
  	if (!insns)
  		return insns;
  
  	for (i = 0; i < prog->len; i++) {
  		if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
  			insns[i].code = BPF_JMP | BPF_CALL;
  			insns[i].imm = BPF_FUNC_tail_call;
  			/* fall-through */
  		}
  		if (insns[i].code == (BPF_JMP | BPF_CALL) ||
  		    insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
  			if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
  				insns[i].code = BPF_JMP | BPF_CALL;
  			if (!bpf_dump_raw_ok())
  				insns[i].imm = 0;
  			continue;
  		}
  
  		if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
  			continue;
  
  		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
  		map = bpf_map_from_imm(prog, imm);
  		if (map) {
  			insns[i].src_reg = BPF_PSEUDO_MAP_FD;
  			insns[i].imm = map->id;
  			insns[i + 1].imm = 0;
  			continue;
  		}
  
  		if (!bpf_dump_raw_ok() &&
  		    imm == (unsigned long)prog->aux) {
  			insns[i].imm = 0;
  			insns[i + 1].imm = 0;
  			continue;
  		}
  	}
  
  	return insns;
  }
  
  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 = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
  	if (err)
  		return err;
  	info_len = min_t(u32, sizeof(info), info_len);
  
  	memset(&info, 0, sizeof(info));
  	if (copy_from_user(&info, uinfo, info_len))
  		return -EFAULT;
  
  	info.type = prog->type;
  	info.id = prog->aux->id;
  	info.load_time = prog->aux->load_time;
  	info.created_by_uid = from_kuid_munged(current_user_ns(),
  					       prog->aux->user->uid);
  	info.gpl_compatible = prog->gpl_compatible;
  
  	memcpy(info.tag, prog->tag, sizeof(prog->tag));
  	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
  
  	ulen = info.nr_map_ids;
  	info.nr_map_ids = prog->aux->used_map_cnt;
  	ulen = min_t(u32, info.nr_map_ids, ulen);
  	if (ulen) {
  		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
  		u32 i;
  
  		for (i = 0; i < ulen; i++)
  			if (put_user(prog->aux->used_maps[i]->id,
  				     &user_map_ids[i]))
  				return -EFAULT;
  	}
  
  	if (!capable(CAP_SYS_ADMIN)) {
  		info.jited_prog_len = 0;
  		info.xlated_prog_len = 0;
  		info.nr_jited_ksyms = 0;
  		info.nr_jited_func_lens = 0;
  		goto done;
  	}
  
  	ulen = info.xlated_prog_len;
  	info.xlated_prog_len = bpf_prog_insn_size(prog);
  	if (info.xlated_prog_len && ulen) {
  		struct bpf_insn *insns_sanitized;
  		bool fault;
  
  		if (prog->blinded && !bpf_dump_raw_ok()) {
  			info.xlated_prog_insns = 0;
  			goto done;
  		}
  		insns_sanitized = bpf_insn_prepare_dump(prog);
  		if (!insns_sanitized)
  			return -ENOMEM;
  		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
  		ulen = min_t(u32, info.xlated_prog_len, ulen);
  		fault = copy_to_user(uinsns, insns_sanitized, ulen);
  		kfree(insns_sanitized);
  		if (fault)
  			return -EFAULT;
  	}
  
  	if (bpf_prog_is_dev_bound(prog->aux)) {
  		err = bpf_prog_offload_info_fill(&info, prog);
  		if (err)
  			return err;
  		goto done;
  	}
  
  	/* NOTE: the following code is supposed to be skipped for offload.
  	 * bpf_prog_offload_info_fill() is the place to fill similar fields
  	 * for offload.
  	 */
  	ulen = info.jited_prog_len;
  	if (prog->aux->func_cnt) {
  		u32 i;
  
  		info.jited_prog_len = 0;
  		for (i = 0; i < prog->aux->func_cnt; i++)
  			info.jited_prog_len += prog->aux->func[i]->jited_len;
  	} else {
  		info.jited_prog_len = prog->jited_len;
  	}
  
  	if (info.jited_prog_len && ulen) {
  		if (bpf_dump_raw_ok()) {
  			uinsns = u64_to_user_ptr(info.jited_prog_insns);
  			ulen = min_t(u32, info.jited_prog_len, ulen);
  
  			/* for multi-function programs, copy the JITed
  			 * instructions for all the functions
  			 */
  			if (prog->aux->func_cnt) {
  				u32 len, free, i;
  				u8 *img;
  
  				free = ulen;
  				for (i = 0; i < prog->aux->func_cnt; i++) {
  					len = prog->aux->func[i]->jited_len;
  					len = min_t(u32, len, free);
  					img = (u8 *) prog->aux->func[i]->bpf_func;
  					if (copy_to_user(uinsns, img, len))
  						return -EFAULT;
  					uinsns += len;
  					free -= len;
  					if (!free)
  						break;
  				}
  			} else {
  				if (copy_to_user(uinsns, prog->bpf_func, ulen))
  					return -EFAULT;
  			}
  		} else {
  			info.jited_prog_insns = 0;
  		}
  	}
  
  	ulen = info.nr_jited_ksyms;
  	info.nr_jited_ksyms = prog->aux->func_cnt;
  	if (info.nr_jited_ksyms && ulen) {
  		if (bpf_dump_raw_ok()) {
  			u64 __user *user_ksyms;
  			ulong ksym_addr;
  			u32 i;
  
  			/* copy the address of the kernel symbol
  			 * corresponding to each function
  			 */
  			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
  			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
  			for (i = 0; i < ulen; i++) {
  				ksym_addr = (ulong) prog->aux->func[i]->bpf_func;
  				ksym_addr &= PAGE_MASK;
  				if (put_user((u64) ksym_addr, &user_ksyms[i]))
  					return -EFAULT;
  			}
  		} else {
  			info.jited_ksyms = 0;
  		}
  	}
  
  	ulen = info.nr_jited_func_lens;
  	info.nr_jited_func_lens = prog->aux->func_cnt;
  	if (info.nr_jited_func_lens && ulen) {
  		if (bpf_dump_raw_ok()) {
  			u32 __user *user_lens;
  			u32 func_len, i;
  
  			/* copy the JITed image lengths for each function */
  			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
  			user_lens = u64_to_user_ptr(info.jited_func_lens);
  			for (i = 0; i < ulen; i++) {
  				func_len = prog->aux->func[i]->jited_len;
  				if (put_user(func_len, &user_lens[i]))
  					return -EFAULT;
  			}
  		} else {
  			info.jited_func_lens = 0;
  		}
  	}
  
  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 = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
  	if (err)
  		return err;
  	info_len = min_t(u32, sizeof(info), info_len);
  
  	memset(&info, 0, sizeof(info));
  	info.type = map->map_type;
  	info.id = map->id;
  	info.key_size = map->key_size;
  	info.value_size = map->value_size;
  	info.max_entries = map->max_entries;
  	info.map_flags = map->map_flags;
  	memcpy(info.name, map->name, sizeof(map->name));
  
  	if (map->btf) {
  		info.btf_id = btf_id(map->btf);
  		info.btf_key_type_id = map->btf_key_type_id;
  		info.btf_value_type_id = map->btf_value_type_id;
  	}
  
  	if (bpf_map_is_dev_bound(map)) {
  		err = bpf_map_offload_info_fill(&info, map);
  		if (err)
  			return err;
  	}
  
  	if (copy_to_user(uinfo, &info, info_len) ||
  	    put_user(info_len, &uattr->info.info_len))
  		return -EFAULT;
  
  	return 0;
  }
  
  static int bpf_btf_get_info_by_fd(struct btf *btf,
  				  const union bpf_attr *attr,
  				  union bpf_attr __user *uattr)
  {
  	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
  	u32 info_len = attr->info.info_len;
  	int err;
  
  	err = bpf_check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len);
  	if (err)
  		return err;
  
  	return btf_get_info_by_fd(btf, attr, uattr);
  }
  
  #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 if (f.file->f_op == &btf_fops)
  		err = bpf_btf_get_info_by_fd(f.file->private_data, attr, uattr);
  	else
  		err = -EINVAL;
  
  	fdput(f);
  	return err;
  }
  
  #define BPF_BTF_LOAD_LAST_FIELD btf_log_level
  
  static int bpf_btf_load(const union bpf_attr *attr)
  {
  	if (CHECK_ATTR(BPF_BTF_LOAD))
  		return -EINVAL;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	return btf_new_fd(attr);
  }
  
  #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
  
  static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
  {
  	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
  		return -EINVAL;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	return btf_get_fd_by_id(attr->btf_id);
  }
  
  static int bpf_task_fd_query_copy(const union bpf_attr *attr,
  				    union bpf_attr __user *uattr,
  				    u32 prog_id, u32 fd_type,
  				    const char *buf, u64 probe_offset,
  				    u64 probe_addr)
  {
  	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
  	u32 len = buf ? strlen(buf) : 0, input_len;
  	int err = 0;
  
  	if (put_user(len, &uattr->task_fd_query.buf_len))
  		return -EFAULT;
  	input_len = attr->task_fd_query.buf_len;
  	if (input_len && ubuf) {
  		if (!len) {
  			/* nothing to copy, just make ubuf NULL terminated */
  			char zero = '\0';
  
  			if (put_user(zero, ubuf))
  				return -EFAULT;
  		} else if (input_len >= len + 1) {
  			/* ubuf can hold the string with NULL terminator */
  			if (copy_to_user(ubuf, buf, len + 1))
  				return -EFAULT;
  		} else {
  			/* ubuf cannot hold the string with NULL terminator,
  			 * do a partial copy with NULL terminator.
  			 */
  			char zero = '\0';
  
  			err = -ENOSPC;
  			if (copy_to_user(ubuf, buf, input_len - 1))
  				return -EFAULT;
  			if (put_user(zero, ubuf + input_len - 1))
  				return -EFAULT;
  		}
  	}
  
  	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
  	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
  	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
  	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
  		return -EFAULT;
  
  	return err;
  }
  
  #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
  
  static int bpf_task_fd_query(const union bpf_attr *attr,
  			     union bpf_attr __user *uattr)
  {
  	pid_t pid = attr->task_fd_query.pid;
  	u32 fd = attr->task_fd_query.fd;
  	const struct perf_event *event;
  	struct files_struct *files;
  	struct task_struct *task;
  	struct file *file;
  	int err;
  
  	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
  		return -EINVAL;
  
  	if (!capable(CAP_SYS_ADMIN))
  		return -EPERM;
  
  	if (attr->task_fd_query.flags != 0)
  		return -EINVAL;
  
  	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
  	if (!task)
  		return -ENOENT;
  
  	files = get_files_struct(task);
  	put_task_struct(task);
  	if (!files)
  		return -ENOENT;
  
  	err = 0;
  	spin_lock(&files->file_lock);
  	file = fcheck_files(files, fd);
  	if (!file)
  		err = -EBADF;
  	else
  		get_file(file);
  	spin_unlock(&files->file_lock);
  	put_files_struct(files);
  
  	if (err)
  		goto out;
  
  	if (file->f_op == &bpf_raw_tp_fops) {
  		struct bpf_raw_tracepoint *raw_tp = file->private_data;
  		struct bpf_raw_event_map *btp = raw_tp->btp;
  
  		err = bpf_task_fd_query_copy(attr, uattr,
  					     raw_tp->prog->aux->id,
  					     BPF_FD_TYPE_RAW_TRACEPOINT,
  					     btp->tp->name, 0, 0);
  		goto put_file;
  	}
  
  	event = perf_get_event(file);
  	if (!IS_ERR(event)) {
  		u64 probe_offset, probe_addr;
  		u32 prog_id, fd_type;
  		const char *buf;
  
  		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
  					      &buf, &probe_offset,
  					      &probe_addr);
  		if (!err)
  			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
  						     fd_type, buf,
  						     probe_offset,
  						     probe_addr);
  		goto put_file;
  	}
  
  	err = -ENOTSUPP;
  put_file:
  	fput(file);
  out:
  	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 = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
  	if (err)
  		return err;
  	size = min_t(u32, size, sizeof(attr));
  
  	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
  	memset(&attr, 0, sizeof(attr));
  	if (copy_from_user(&attr, uattr, size) != 0)
  		return -EFAULT;
  
  	err = security_bpf(cmd, &attr, size);
  	if (err < 0)
  		return err;
  
  	switch (cmd) {
  	case BPF_MAP_CREATE:
  		err = map_create(&attr);
  		break;
  	case BPF_MAP_LOOKUP_ELEM:
  		err = map_lookup_elem(&attr);
  		break;
  	case BPF_MAP_UPDATE_ELEM:
  		err = map_update_elem(&attr);
  		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;
  	case BPF_PROG_ATTACH:
  		err = bpf_prog_attach(&attr);
  		break;
  	case BPF_PROG_DETACH:
  		err = bpf_prog_detach(&attr);
  		break;
  	case BPF_PROG_QUERY:
  		err = bpf_prog_query(&attr, uattr);
  		break;
  	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;
  	case BPF_RAW_TRACEPOINT_OPEN:
  		err = bpf_raw_tracepoint_open(&attr);
  		break;
  	case BPF_BTF_LOAD:
  		err = bpf_btf_load(&attr);
  		break;
  	case BPF_BTF_GET_FD_BY_ID:
  		err = bpf_btf_get_fd_by_id(&attr);
  		break;
  	case BPF_TASK_FD_QUERY:
  		err = bpf_task_fd_query(&attr, uattr);
  		break;
  	default:
  		err = -EINVAL;
  		break;
  	}
  
  	return err;
  }
  