kernel/bpf/syscall.c

   1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful, but
   8  * WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10  * General Public License for more details.
  11  */
  12 #include <linux/bpf.h>
  13 #include <linux/syscalls.h>
  14 #include <linux/slab.h>
  15 #include <linux/anon_inodes.h>
  16 #include <linux/file.h>
  17 #include <linux/license.h>
  18 #include <linux/filter.h>
  19 #include <linux/version.h>
  20
  21 int sysctl_unprivileged_bpf_disabled __read_mostly;
  22
  23 static LIST_HEAD(bpf_map_types);
  24
  25 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
  26 {
  27         struct bpf_map_type_list *tl;
  28         struct bpf_map *map;
  29
  30         list_for_each_entry(tl, &bpf_map_types, list_node) {
  31                 if (tl->type == attr->map_type) {
  32                         map = tl->ops->map_alloc(attr);
  33                         if (IS_ERR(map))
  34                                 return map;
  35                         map->ops = tl->ops;
  36                         map->map_type = attr->map_type;
  37                         return map;
  38                 }
  39         }
  40         return ERR_PTR(-EINVAL);
  41 }
  42
  43 /* boot time registration of different map implementations */
  44 void bpf_register_map_type(struct bpf_map_type_list *tl)
  45 {
  46         list_add(&tl->list_node, &bpf_map_types);
  47 }
  48
  49 static int bpf_map_charge_memlock(struct bpf_map *map)
  50 {
  51         struct user_struct *user = get_current_user();
  52         unsigned long memlock_limit;
  53
  54         memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
  55
  56         atomic_long_add(map->pages, &user->locked_vm);
  57
  58         if (atomic_long_read(&user->locked_vm) > memlock_limit) {
  59                 atomic_long_sub(map->pages, &user->locked_vm);
  60                 free_uid(user);
  61                 return -EPERM;
  62         }
  63         map->user = user;
  64         return 0;
  65 }
  66
  67 static void bpf_map_uncharge_memlock(struct bpf_map *map)
  68 {
  69         struct user_struct *user = map->user;
  70
  71         atomic_long_sub(map->pages, &user->locked_vm);
  72         free_uid(user);
  73 }
  74
  75 /* called from workqueue */
  76 static void bpf_map_free_deferred(struct work_struct *work)
  77 {
  78         struct bpf_map *map = container_of(work, struct bpf_map, work);
  79
  80         bpf_map_uncharge_memlock(map);
  81         /* implementation dependent freeing */
  82         map->ops->map_free(map);
  83 }
  84
  85 /* decrement map refcnt and schedule it for freeing via workqueue
  86  * (unrelying map implementation ops->map_free() might sleep)
  87  */
  88 void bpf_map_put(struct bpf_map *map)
  89 {
  90         if (atomic_dec_and_test(&map->refcnt)) {
  91                 INIT_WORK(&map->work, bpf_map_free_deferred);
  92                 schedule_work(&map->work);
  93         }
  94 }
  95
  96 static int bpf_map_release(struct inode *inode, struct file *filp)
  97 {
  98         struct bpf_map *map = filp->private_data;
  99
 100         if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
 101                 /* prog_array stores refcnt-ed bpf_prog pointers
 102                  * release them all when user space closes prog_array_fd
 103                  */
 104                 bpf_fd_array_map_clear(map);
 105
 106         bpf_map_put(map);
 107         return 0;
 108 }
 109
 110 static const struct file_operations bpf_map_fops = {
 111         .release = bpf_map_release,
 112 };
 113
 114 /* helper macro to check that unused fields 'union bpf_attr' are zero */
 115 #define CHECK_ATTR(CMD) \
 116         memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
 117                    sizeof(attr->CMD##_LAST_FIELD), 0, \
 118                    sizeof(*attr) - \
 119                    offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
 120                    sizeof(attr->CMD##_LAST_FIELD)) != NULL
 121
 122 #define BPF_MAP_CREATE_LAST_FIELD max_entries
 123 /* called via syscall */
 124 static int map_create(union bpf_attr *attr)
 125 {
 126         struct bpf_map *map;
 127         int err;
 128
 129         err = CHECK_ATTR(BPF_MAP_CREATE);
 130         if (err)
 131                 return -EINVAL;
 132
 133         /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
 134         map = find_and_alloc_map(attr);
 135         if (IS_ERR(map))
 136                 return PTR_ERR(map);
 137
 138         atomic_set(&map->refcnt, 1);
 139
 140         err = bpf_map_charge_memlock(map);
 141         if (err)
 142                 goto free_map;
 143
 144         err = anon_inode_getfd("bpf-map", &bpf_map_fops, map, O_RDWR | O_CLOEXEC);
 145
 146         if (err < 0)
 147                 /* failed to allocate fd */
 148                 goto free_map;
 149
 150         return err;
 151
 152 free_map:
 153         map->ops->map_free(map);
 154         return err;
 155 }
 156
 157 /* if error is returned, fd is released.
 158  * On success caller should complete fd access with matching fdput()
 159  */
 160 struct bpf_map *bpf_map_get(struct fd f)
 161 {
 162         struct bpf_map *map;
 163
 164         if (!f.file)
 165                 return ERR_PTR(-EBADF);
 166
 167         if (f.file->f_op != &bpf_map_fops) {
 168                 fdput(f);
 169                 return ERR_PTR(-EINVAL);
 170         }
 171
 172         map = f.file->private_data;
 173
 174         return map;
 175 }
 176
 177 /* helper to convert user pointers passed inside __aligned_u64 fields */
 178 static void __user *u64_to_ptr(__u64 val)
 179 {
 180         return (void __user *) (unsigned long) val;
 181 }
 182
 183 /* last field in 'union bpf_attr' used by this command */
 184 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
 185
 186 static int map_lookup_elem(union bpf_attr *attr)
 187 {
 188         void __user *ukey = u64_to_ptr(attr->key);
 189         void __user *uvalue = u64_to_ptr(attr->value);
 190         int ufd = attr->map_fd;
 191         struct bpf_map *map;
 192         void *key, *value, *ptr;
 193         struct fd f;
 194         int err;
 195
 196         if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
 197                 return -EINVAL;
 198
 199         f = fdget(ufd);
 200         map = bpf_map_get(f);
 201         if (IS_ERR(map))
 202                 return PTR_ERR(map);
 203
 204         err = -ENOMEM;
 205         key = kmalloc(map->key_size, GFP_USER);
 206         if (!key)
 207                 goto err_put;
 208
 209         err = -EFAULT;
 210         if (copy_from_user(key, ukey, map->key_size) != 0)
 211                 goto free_key;
 212
 213         err = -ENOMEM;
 214         value = kmalloc(map->value_size, GFP_USER);
 215         if (!value)
 216                 goto free_key;
 217
 218         rcu_read_lock();
 219         ptr = map->ops->map_lookup_elem(map, key);
 220         if (ptr)
 221                 memcpy(value, ptr, map->value_size);
 222         rcu_read_unlock();
 223
 224         err = -ENOENT;
 225         if (!ptr)
 226                 goto free_value;
 227
 228         err = -EFAULT;
 229         if (copy_to_user(uvalue, value, map->value_size) != 0)
 230                 goto free_value;
 231
 232         err = 0;
 233
 234 free_value:
 235         kfree(value);
 236 free_key:
 237         kfree(key);
 238 err_put:
 239         fdput(f);
 240         return err;
 241 }
 242
 243 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
 244
 245 static int map_update_elem(union bpf_attr *attr)
 246 {
 247         void __user *ukey = u64_to_ptr(attr->key);
 248         void __user *uvalue = u64_to_ptr(attr->value);
 249         int ufd = attr->map_fd;
 250         struct bpf_map *map;
 251         void *key, *value;
 252         struct fd f;
 253         int err;
 254
 255         if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
 256                 return -EINVAL;
 257
 258         f = fdget(ufd);
 259         map = bpf_map_get(f);
 260         if (IS_ERR(map))
 261                 return PTR_ERR(map);
 262
 263         err = -ENOMEM;
 264         key = kmalloc(map->key_size, GFP_USER);
 265         if (!key)
 266                 goto err_put;
 267
 268         err = -EFAULT;
 269         if (copy_from_user(key, ukey, map->key_size) != 0)
 270                 goto free_key;
 271
 272         err = -ENOMEM;
 273         value = kmalloc(map->value_size, GFP_USER);
 274         if (!value)
 275                 goto free_key;
 276
 277         err = -EFAULT;
 278         if (copy_from_user(value, uvalue, map->value_size) != 0)
 279                 goto free_value;
 280
 281         /* eBPF program that use maps are running under rcu_read_lock(),
 282          * therefore all map accessors rely on this fact, so do the same here
 283          */
 284         rcu_read_lock();
 285         err = map->ops->map_update_elem(map, key, value, attr->flags);
 286         rcu_read_unlock();
 287
 288 free_value:
 289         kfree(value);
 290 free_key:
 291         kfree(key);
 292 err_put:
 293         fdput(f);
 294         return err;
 295 }
 296
 297 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
 298
 299 static int map_delete_elem(union bpf_attr *attr)
 300 {
 301         void __user *ukey = u64_to_ptr(attr->key);
 302         int ufd = attr->map_fd;
 303         struct bpf_map *map;
 304         struct fd f;
 305         void *key;
 306         int err;
 307
 308         if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
 309                 return -EINVAL;
 310
 311         f = fdget(ufd);
 312         map = bpf_map_get(f);
 313         if (IS_ERR(map))
 314                 return PTR_ERR(map);
 315
 316         err = -ENOMEM;
 317         key = kmalloc(map->key_size, GFP_USER);
 318         if (!key)
 319                 goto err_put;
 320
 321         err = -EFAULT;
 322         if (copy_from_user(key, ukey, map->key_size) != 0)
 323                 goto free_key;
 324
 325         rcu_read_lock();
 326         err = map->ops->map_delete_elem(map, key);
 327         rcu_read_unlock();
 328
 329 free_key:
 330         kfree(key);
 331 err_put:
 332         fdput(f);
 333         return err;
 334 }
 335
 336 /* last field in 'union bpf_attr' used by this command */
 337 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
 338
 339 static int map_get_next_key(union bpf_attr *attr)
 340 {
 341         void __user *ukey = u64_to_ptr(attr->key);
 342         void __user *unext_key = u64_to_ptr(attr->next_key);
 343         int ufd = attr->map_fd;
 344         struct bpf_map *map;
 345         void *key, *next_key;
 346         struct fd f;
 347         int err;
 348
 349         if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
 350                 return -EINVAL;
 351
 352         f = fdget(ufd);
 353         map = bpf_map_get(f);
 354         if (IS_ERR(map))
 355                 return PTR_ERR(map);
 356
 357         err = -ENOMEM;
 358         key = kmalloc(map->key_size, GFP_USER);
 359         if (!key)
 360                 goto err_put;
 361
 362         err = -EFAULT;
 363         if (copy_from_user(key, ukey, map->key_size) != 0)
 364                 goto free_key;
 365
 366         err = -ENOMEM;
 367         next_key = kmalloc(map->key_size, GFP_USER);
 368         if (!next_key)
 369                 goto free_key;
 370
 371         rcu_read_lock();
 372         err = map->ops->map_get_next_key(map, key, next_key);
 373         rcu_read_unlock();
 374         if (err)
 375                 goto free_next_key;
 376
 377         err = -EFAULT;
 378         if (copy_to_user(unext_key, next_key, map->key_size) != 0)
 379                 goto free_next_key;
 380
 381         err = 0;
 382
 383 free_next_key:
 384         kfree(next_key);
 385 free_key:
 386         kfree(key);
 387 err_put:
 388         fdput(f);
 389         return err;
 390 }
 391
 392 static LIST_HEAD(bpf_prog_types);
 393
 394 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
 395 {
 396         struct bpf_prog_type_list *tl;
 397
 398         list_for_each_entry(tl, &bpf_prog_types, list_node) {
 399                 if (tl->type == type) {
 400                         prog->aux->ops = tl->ops;
 401                         prog->type = type;
 402                         return 0;
 403                 }
 404         }
 405
 406         return -EINVAL;
 407 }
 408
 409 void bpf_register_prog_type(struct bpf_prog_type_list *tl)
 410 {
 411         list_add(&tl->list_node, &bpf_prog_types);
 412 }
 413
 414 /* fixup insn->imm field of bpf_call instructions:
 415  * if (insn->imm == BPF_FUNC_map_lookup_elem)
 416  *      insn->imm = bpf_map_lookup_elem - __bpf_call_base;
 417  * else if (insn->imm == BPF_FUNC_map_update_elem)
 418  *      insn->imm = bpf_map_update_elem - __bpf_call_base;
 419  * else ...
 420  *
 421  * this function is called after eBPF program passed verification
 422  */
 423 static void fixup_bpf_calls(struct bpf_prog *prog)
 424 {
 425         const struct bpf_func_proto *fn;
 426         int i;
 427
 428         for (i = 0; i < prog->len; i++) {
 429                 struct bpf_insn *insn = &prog->insnsi[i];
 430
 431                 if (insn->code == (BPF_JMP | BPF_CALL)) {
 432                         /* we reach here when program has bpf_call instructions
 433                          * and it passed bpf_check(), means that
 434                          * ops->get_func_proto must have been supplied, check it
 435                          */
 436                         BUG_ON(!prog->aux->ops->get_func_proto);
 437
 438                         if (insn->imm == BPF_FUNC_get_route_realm)
 439                                 prog->dst_needed = 1;
 440                         if (insn->imm == BPF_FUNC_get_prandom_u32)
 441                                 bpf_user_rnd_init_once();
 442                         if (insn->imm == BPF_FUNC_tail_call) {
 443                                 /* mark bpf_tail_call as different opcode
 444                                  * to avoid conditional branch in
 445                                  * interpeter for every normal call
 446                                  * and to prevent accidental JITing by
 447                                  * JIT compiler that doesn't support
 448                                  * bpf_tail_call yet
 449                                  */
 450                                 insn->imm = 0;
 451                                 insn->code |= BPF_X;
 452                                 continue;
 453                         }
 454
 455                         fn = prog->aux->ops->get_func_proto(insn->imm);
 456                         /* all functions that have prototype and verifier allowed
 457                          * programs to call them, must be real in-kernel functions
 458                          */
 459                         BUG_ON(!fn->func);
 460                         insn->imm = fn->func - __bpf_call_base;
 461                 }
 462         }
 463 }
 464
 465 /* drop refcnt on maps used by eBPF program and free auxilary data */
 466 static void free_used_maps(struct bpf_prog_aux *aux)
 467 {
 468         int i;
 469
 470         for (i = 0; i < aux->used_map_cnt; i++)
 471                 bpf_map_put(aux->used_maps[i]);
 472
 473         kfree(aux->used_maps);
 474 }
 475
 476 static int bpf_prog_charge_memlock(struct bpf_prog *prog)
 477 {
 478         struct user_struct *user = get_current_user();
 479         unsigned long memlock_limit;
 480
 481         memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 482
 483         atomic_long_add(prog->pages, &user->locked_vm);
 484         if (atomic_long_read(&user->locked_vm) > memlock_limit) {
 485                 atomic_long_sub(prog->pages, &user->locked_vm);
 486                 free_uid(user);
 487                 return -EPERM;
 488         }
 489         prog->aux->user = user;
 490         return 0;
 491 }
 492
 493 static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
 494 {
 495         struct user_struct *user = prog->aux->user;
 496
 497         atomic_long_sub(prog->pages, &user->locked_vm);
 498         free_uid(user);
 499 }
 500
 501 static void __prog_put_rcu(struct rcu_head *rcu)
 502 {
 503         struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
 504
 505         free_used_maps(aux);
 506         bpf_prog_uncharge_memlock(aux->prog);
 507         bpf_prog_free(aux->prog);
 508 }
 509
 510 /* version of bpf_prog_put() that is called after a grace period */
 511 void bpf_prog_put_rcu(struct bpf_prog *prog)
 512 {
 513         if (atomic_dec_and_test(&prog->aux->refcnt)) {
 514                 prog->aux->prog = prog;
 515                 call_rcu(&prog->aux->rcu, __prog_put_rcu);
 516         }
 517 }
 518
 519 void bpf_prog_put(struct bpf_prog *prog)
 520 {
 521         if (atomic_dec_and_test(&prog->aux->refcnt)) {
 522                 free_used_maps(prog->aux);
 523                 bpf_prog_free(prog);
 524         }
 525 }
 526 EXPORT_SYMBOL_GPL(bpf_prog_put);
 527
 528 static int bpf_prog_release(struct inode *inode, struct file *filp)
 529 {
 530         struct bpf_prog *prog = filp->private_data;
 531
 532         bpf_prog_put_rcu(prog);
 533         return 0;
 534 }
 535
 536 static const struct file_operations bpf_prog_fops = {
 537         .release = bpf_prog_release,
 538 };
 539
 540 static struct bpf_prog *get_prog(struct fd f)
 541 {
 542         struct bpf_prog *prog;
 543
 544         if (!f.file)
 545                 return ERR_PTR(-EBADF);
 546
 547         if (f.file->f_op != &bpf_prog_fops) {
 548                 fdput(f);
 549                 return ERR_PTR(-EINVAL);
 550         }
 551
 552         prog = f.file->private_data;
 553
 554         return prog;
 555 }
 556
 557 /* called by sockets/tracing/seccomp before attaching program to an event
 558  * pairs with bpf_prog_put()
 559  */
 560 struct bpf_prog *bpf_prog_get(u32 ufd)
 561 {
 562         struct fd f = fdget(ufd);
 563         struct bpf_prog *prog;
 564
 565         prog = get_prog(f);
 566
 567         if (IS_ERR(prog))
 568                 return prog;
 569
 570         atomic_inc(&prog->aux->refcnt);
 571         fdput(f);
 572         return prog;
 573 }
 574 EXPORT_SYMBOL_GPL(bpf_prog_get);
 575
 576 /* last field in 'union bpf_attr' used by this command */
 577 #define BPF_PROG_LOAD_LAST_FIELD kern_version
 578
 579 static int bpf_prog_load(union bpf_attr *attr)
 580 {
 581         enum bpf_prog_type type = attr->prog_type;
 582         struct bpf_prog *prog;
 583         int err;
 584         char license[128];
 585         bool is_gpl;
 586
 587         if (CHECK_ATTR(BPF_PROG_LOAD))
 588                 return -EINVAL;
 589
 590         /* copy eBPF program license from user space */
 591         if (strncpy_from_user(license, u64_to_ptr(attr->license),
 592                               sizeof(license) - 1) < 0)
 593                 return -EFAULT;
 594         license[sizeof(license) - 1] = 0;
 595
 596         /* eBPF programs must be GPL compatible to use GPL-ed functions */
 597         is_gpl = license_is_gpl_compatible(license);
 598
 599         if (attr->insn_cnt >= BPF_MAXINSNS)
 600                 return -EINVAL;
 601
 602         if (type == BPF_PROG_TYPE_KPROBE &&
 603             attr->kern_version != LINUX_VERSION_CODE)
 604                 return -EINVAL;
 605
 606         if (type != BPF_PROG_TYPE_SOCKET_FILTER && !capable(CAP_SYS_ADMIN))
 607                 return -EPERM;
 608
 609         /* plain bpf_prog allocation */
 610         prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
 611         if (!prog)
 612                 return -ENOMEM;
 613
 614         err = bpf_prog_charge_memlock(prog);
 615         if (err)
 616                 goto free_prog_nouncharge;
 617
 618         prog->len = attr->insn_cnt;
 619
 620         err = -EFAULT;
 621         if (copy_from_user(prog->insns, u64_to_ptr(attr->insns),
 622                            prog->len * sizeof(struct bpf_insn)) != 0)
 623                 goto free_prog;
 624
 625         prog->orig_prog = NULL;
 626         prog->jited = 0;
 627
 628         atomic_set(&prog->aux->refcnt, 1);
 629         prog->gpl_compatible = is_gpl ? 1 : 0;
 630
 631         /* find program type: socket_filter vs tracing_filter */
 632         err = find_prog_type(type, prog);
 633         if (err < 0)
 634                 goto free_prog;
 635
 636         /* run eBPF verifier */
 637         err = bpf_check(&prog, attr);
 638         if (err < 0)
 639                 goto free_used_maps;
 640
 641         /* fixup BPF_CALL->imm field */
 642         fixup_bpf_calls(prog);
 643
 644         /* eBPF program is ready to be JITed */
 645         err = bpf_prog_select_runtime(prog);
 646         if (err < 0)
 647                 goto free_used_maps;
 648
 649         err = anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, O_RDWR | O_CLOEXEC);
 650         if (err < 0)
 651                 /* failed to allocate fd */
 652                 goto free_used_maps;
 653
 654         return err;
 655
 656 free_used_maps:
 657         free_used_maps(prog->aux);
 658 free_prog:
 659         bpf_prog_uncharge_memlock(prog);
 660 free_prog_nouncharge:
 661         bpf_prog_free(prog);
 662         return err;
 663 }
 664
 665 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
 666 {
 667         union bpf_attr attr = {};
 668         int err;
 669
 670         if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled)
 671                 return -EPERM;
 672
 673         if (!access_ok(VERIFY_READ, uattr, 1))
 674                 return -EFAULT;
 675
 676         if (size > PAGE_SIZE)   /* silly large */
 677                 return -E2BIG;
 678
 679         /* If we're handed a bigger struct than we know of,
 680          * ensure all the unknown bits are 0 - i.e. new
 681          * user-space does not rely on any kernel feature
 682          * extensions we dont know about yet.
 683          */
 684         if (size > sizeof(attr)) {
 685                 unsigned char __user *addr;
 686                 unsigned char __user *end;
 687                 unsigned char val;
 688
 689                 addr = (void __user *)uattr + sizeof(attr);
 690                 end  = (void __user *)uattr + size;
 691
 692                 for (; addr < end; addr++) {
 693                         err = get_user(val, addr);
 694                         if (err)
 695                                 return err;
 696                         if (val)
 697                                 return -E2BIG;
 698                 }
 699                 size = sizeof(attr);
 700         }
 701
 702         /* copy attributes from user space, may be less than sizeof(bpf_attr) */
 703         if (copy_from_user(&attr, uattr, size) != 0)
 704                 return -EFAULT;
 705
 706         switch (cmd) {
 707         case BPF_MAP_CREATE:
 708                 err = map_create(&attr);
 709                 break;
 710         case BPF_MAP_LOOKUP_ELEM:
 711                 err = map_lookup_elem(&attr);
 712                 break;
 713         case BPF_MAP_UPDATE_ELEM:
 714                 err = map_update_elem(&attr);
 715                 break;
 716         case BPF_MAP_DELETE_ELEM:
 717                 err = map_delete_elem(&attr);
 718                 break;
 719         case BPF_MAP_GET_NEXT_KEY:
 720                 err = map_get_next_key(&attr);
 721                 break;
 722         case BPF_PROG_LOAD:
 723                 err = bpf_prog_load(&attr);
 724                 break;
 725         default:
 726                 err = -EINVAL;
 727                 break;
 728         }
 729
 730         return err;
 731 }