1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 */ 4 #include <linux/bpf.h> 5 #include <linux/bpf-cgroup.h> 6 #include <linux/bpf_trace.h> 7 #include <linux/bpf_lirc.h> 8 #include <linux/bpf_verifier.h> 9 #include <linux/bsearch.h> 10 #include <linux/btf.h> 11 #include <linux/syscalls.h> 12 #include <linux/slab.h> 13 #include <linux/sched/signal.h> 14 #include <linux/vmalloc.h> 15 #include <linux/mmzone.h> 16 #include <linux/anon_inodes.h> 17 #include <linux/fdtable.h> 18 #include <linux/file.h> 19 #include <linux/fs.h> 20 #include <linux/license.h> 21 #include <linux/filter.h> 22 #include <linux/kernel.h> 23 #include <linux/idr.h> 24 #include <linux/cred.h> 25 #include <linux/timekeeping.h> 26 #include <linux/ctype.h> 27 #include <linux/nospec.h> 28 #include <linux/audit.h> 29 #include <uapi/linux/btf.h> 30 #include <linux/pgtable.h> 31 #include <linux/bpf_lsm.h> 32 #include <linux/poll.h> 33 #include <linux/sort.h> 34 #include <linux/bpf-netns.h> 35 #include <linux/rcupdate_trace.h> 36 #include <linux/memcontrol.h> 37 #include <linux/trace_events.h> 38 39 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ 40 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ 41 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 42 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) 43 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) 44 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ 45 IS_FD_HASH(map)) 46 47 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) 48 49 DEFINE_PER_CPU(int, bpf_prog_active); 50 static DEFINE_IDR(prog_idr); 51 static DEFINE_SPINLOCK(prog_idr_lock); 52 static DEFINE_IDR(map_idr); 53 static DEFINE_SPINLOCK(map_idr_lock); 54 static DEFINE_IDR(link_idr); 55 static DEFINE_SPINLOCK(link_idr_lock); 56 57 int sysctl_unprivileged_bpf_disabled __read_mostly = 58 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; 59 60 static const struct bpf_map_ops * const bpf_map_types[] = { 61 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 62 #define BPF_MAP_TYPE(_id, _ops) \ 63 [_id] = &_ops, 64 #define BPF_LINK_TYPE(_id, _name) 65 #include <linux/bpf_types.h> 66 #undef BPF_PROG_TYPE 67 #undef BPF_MAP_TYPE 68 #undef BPF_LINK_TYPE 69 }; 70 71 /* 72 * If we're handed a bigger struct than we know of, ensure all the unknown bits 73 * are 0 - i.e. new user-space does not rely on any kernel feature extensions 74 * we don't know about yet. 75 * 76 * There is a ToCToU between this function call and the following 77 * copy_from_user() call. However, this is not a concern since this function is 78 * meant to be a future-proofing of bits. 79 */ 80 int bpf_check_uarg_tail_zero(bpfptr_t uaddr, 81 size_t expected_size, 82 size_t actual_size) 83 { 84 int res; 85 86 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ 87 return -E2BIG; 88 89 if (actual_size <= expected_size) 90 return 0; 91 92 if (uaddr.is_kernel) 93 res = memchr_inv(uaddr.kernel + expected_size, 0, 94 actual_size - expected_size) == NULL; 95 else 96 res = check_zeroed_user(uaddr.user + expected_size, 97 actual_size - expected_size); 98 if (res < 0) 99 return res; 100 return res ? 0 : -E2BIG; 101 } 102 103 const struct bpf_map_ops bpf_map_offload_ops = { 104 .map_meta_equal = bpf_map_meta_equal, 105 .map_alloc = bpf_map_offload_map_alloc, 106 .map_free = bpf_map_offload_map_free, 107 .map_check_btf = map_check_no_btf, 108 }; 109 110 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) 111 { 112 const struct bpf_map_ops *ops; 113 u32 type = attr->map_type; 114 struct bpf_map *map; 115 int err; 116 117 if (type >= ARRAY_SIZE(bpf_map_types)) 118 return ERR_PTR(-EINVAL); 119 type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types)); 120 ops = bpf_map_types[type]; 121 if (!ops) 122 return ERR_PTR(-EINVAL); 123 124 if (ops->map_alloc_check) { 125 err = ops->map_alloc_check(attr); 126 if (err) 127 return ERR_PTR(err); 128 } 129 if (attr->map_ifindex) 130 ops = &bpf_map_offload_ops; 131 map = ops->map_alloc(attr); 132 if (IS_ERR(map)) 133 return map; 134 map->ops = ops; 135 map->map_type = type; 136 return map; 137 } 138 139 static void bpf_map_write_active_inc(struct bpf_map *map) 140 { 141 atomic64_inc(&map->writecnt); 142 } 143 144 static void bpf_map_write_active_dec(struct bpf_map *map) 145 { 146 atomic64_dec(&map->writecnt); 147 } 148 149 bool bpf_map_write_active(const struct bpf_map *map) 150 { 151 return atomic64_read(&map->writecnt) != 0; 152 } 153 154 static u32 bpf_map_value_size(const struct bpf_map *map) 155 { 156 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 157 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 158 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || 159 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) 160 return round_up(map->value_size, 8) * num_possible_cpus(); 161 else if (IS_FD_MAP(map)) 162 return sizeof(u32); 163 else 164 return map->value_size; 165 } 166 167 static void maybe_wait_bpf_programs(struct bpf_map *map) 168 { 169 /* Wait for any running BPF programs to complete so that 170 * userspace, when we return to it, knows that all programs 171 * that could be running use the new map value. 172 */ 173 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || 174 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 175 synchronize_rcu(); 176 } 177 178 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, 179 void *key, void *value, __u64 flags) 180 { 181 int err; 182 183 /* Need to create a kthread, thus must support schedule */ 184 if (bpf_map_is_dev_bound(map)) { 185 return bpf_map_offload_update_elem(map, key, value, flags); 186 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || 187 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 188 return map->ops->map_update_elem(map, key, value, flags); 189 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || 190 map->map_type == BPF_MAP_TYPE_SOCKMAP) { 191 return sock_map_update_elem_sys(map, key, value, flags); 192 } else if (IS_FD_PROG_ARRAY(map)) { 193 return bpf_fd_array_map_update_elem(map, map_file, key, value, 194 flags); 195 } 196 197 bpf_disable_instrumentation(); 198 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 199 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 200 err = bpf_percpu_hash_update(map, key, value, flags); 201 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 202 err = bpf_percpu_array_update(map, key, value, flags); 203 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 204 err = bpf_percpu_cgroup_storage_update(map, key, value, 205 flags); 206 } else if (IS_FD_ARRAY(map)) { 207 rcu_read_lock(); 208 err = bpf_fd_array_map_update_elem(map, map_file, key, value, 209 flags); 210 rcu_read_unlock(); 211 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 212 rcu_read_lock(); 213 err = bpf_fd_htab_map_update_elem(map, map_file, key, value, 214 flags); 215 rcu_read_unlock(); 216 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 217 /* rcu_read_lock() is not needed */ 218 err = bpf_fd_reuseport_array_update_elem(map, key, value, 219 flags); 220 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 221 map->map_type == BPF_MAP_TYPE_STACK || 222 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 223 err = map->ops->map_push_elem(map, value, flags); 224 } else { 225 rcu_read_lock(); 226 err = map->ops->map_update_elem(map, key, value, flags); 227 rcu_read_unlock(); 228 } 229 bpf_enable_instrumentation(); 230 maybe_wait_bpf_programs(map); 231 232 return err; 233 } 234 235 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, 236 __u64 flags) 237 { 238 void *ptr; 239 int err; 240 241 if (bpf_map_is_dev_bound(map)) 242 return bpf_map_offload_lookup_elem(map, key, value); 243 244 bpf_disable_instrumentation(); 245 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 246 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 247 err = bpf_percpu_hash_copy(map, key, value); 248 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 249 err = bpf_percpu_array_copy(map, key, value); 250 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 251 err = bpf_percpu_cgroup_storage_copy(map, key, value); 252 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 253 err = bpf_stackmap_copy(map, key, value); 254 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { 255 err = bpf_fd_array_map_lookup_elem(map, key, value); 256 } else if (IS_FD_HASH(map)) { 257 err = bpf_fd_htab_map_lookup_elem(map, key, value); 258 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 259 err = bpf_fd_reuseport_array_lookup_elem(map, key, value); 260 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 261 map->map_type == BPF_MAP_TYPE_STACK || 262 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 263 err = map->ops->map_peek_elem(map, value); 264 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 265 /* struct_ops map requires directly updating "value" */ 266 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value); 267 } else { 268 rcu_read_lock(); 269 if (map->ops->map_lookup_elem_sys_only) 270 ptr = map->ops->map_lookup_elem_sys_only(map, key); 271 else 272 ptr = map->ops->map_lookup_elem(map, key); 273 if (IS_ERR(ptr)) { 274 err = PTR_ERR(ptr); 275 } else if (!ptr) { 276 err = -ENOENT; 277 } else { 278 err = 0; 279 if (flags & BPF_F_LOCK) 280 /* lock 'ptr' and copy everything but lock */ 281 copy_map_value_locked(map, value, ptr, true); 282 else 283 copy_map_value(map, value, ptr); 284 /* mask lock and timer, since value wasn't zero inited */ 285 check_and_init_map_value(map, value); 286 } 287 rcu_read_unlock(); 288 } 289 290 bpf_enable_instrumentation(); 291 maybe_wait_bpf_programs(map); 292 293 return err; 294 } 295 296 /* Please, do not use this function outside from the map creation path 297 * (e.g. in map update path) without taking care of setting the active 298 * memory cgroup (see at bpf_map_kmalloc_node() for example). 299 */ 300 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) 301 { 302 /* We really just want to fail instead of triggering OOM killer 303 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, 304 * which is used for lower order allocation requests. 305 * 306 * It has been observed that higher order allocation requests done by 307 * vmalloc with __GFP_NORETRY being set might fail due to not trying 308 * to reclaim memory from the page cache, thus we set 309 * __GFP_RETRY_MAYFAIL to avoid such situations. 310 */ 311 312 const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_ACCOUNT; 313 unsigned int flags = 0; 314 unsigned long align = 1; 315 void *area; 316 317 if (size >= SIZE_MAX) 318 return NULL; 319 320 /* kmalloc()'ed memory can't be mmap()'ed */ 321 if (mmapable) { 322 BUG_ON(!PAGE_ALIGNED(size)); 323 align = SHMLBA; 324 flags = VM_USERMAP; 325 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { 326 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, 327 numa_node); 328 if (area != NULL) 329 return area; 330 } 331 332 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 333 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, 334 flags, numa_node, __builtin_return_address(0)); 335 } 336 337 void *bpf_map_area_alloc(u64 size, int numa_node) 338 { 339 return __bpf_map_area_alloc(size, numa_node, false); 340 } 341 342 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) 343 { 344 return __bpf_map_area_alloc(size, numa_node, true); 345 } 346 347 void bpf_map_area_free(void *area) 348 { 349 kvfree(area); 350 } 351 352 static u32 bpf_map_flags_retain_permanent(u32 flags) 353 { 354 /* Some map creation flags are not tied to the map object but 355 * rather to the map fd instead, so they have no meaning upon 356 * map object inspection since multiple file descriptors with 357 * different (access) properties can exist here. Thus, given 358 * this has zero meaning for the map itself, lets clear these 359 * from here. 360 */ 361 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); 362 } 363 364 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) 365 { 366 map->map_type = attr->map_type; 367 map->key_size = attr->key_size; 368 map->value_size = attr->value_size; 369 map->max_entries = attr->max_entries; 370 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); 371 map->numa_node = bpf_map_attr_numa_node(attr); 372 map->map_extra = attr->map_extra; 373 } 374 375 static int bpf_map_alloc_id(struct bpf_map *map) 376 { 377 int id; 378 379 idr_preload(GFP_KERNEL); 380 spin_lock_bh(&map_idr_lock); 381 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); 382 if (id > 0) 383 map->id = id; 384 spin_unlock_bh(&map_idr_lock); 385 idr_preload_end(); 386 387 if (WARN_ON_ONCE(!id)) 388 return -ENOSPC; 389 390 return id > 0 ? 0 : id; 391 } 392 393 void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock) 394 { 395 unsigned long flags; 396 397 /* Offloaded maps are removed from the IDR store when their device 398 * disappears - even if someone holds an fd to them they are unusable, 399 * the memory is gone, all ops will fail; they are simply waiting for 400 * refcnt to drop to be freed. 401 */ 402 if (!map->id) 403 return; 404 405 if (do_idr_lock) 406 spin_lock_irqsave(&map_idr_lock, flags); 407 else 408 __acquire(&map_idr_lock); 409 410 idr_remove(&map_idr, map->id); 411 map->id = 0; 412 413 if (do_idr_lock) 414 spin_unlock_irqrestore(&map_idr_lock, flags); 415 else 416 __release(&map_idr_lock); 417 } 418 419 #ifdef CONFIG_MEMCG_KMEM 420 static void bpf_map_save_memcg(struct bpf_map *map) 421 { 422 /* Currently if a map is created by a process belonging to the root 423 * memory cgroup, get_obj_cgroup_from_current() will return NULL. 424 * So we have to check map->objcg for being NULL each time it's 425 * being used. 426 */ 427 map->objcg = get_obj_cgroup_from_current(); 428 } 429 430 static void bpf_map_release_memcg(struct bpf_map *map) 431 { 432 if (map->objcg) 433 obj_cgroup_put(map->objcg); 434 } 435 436 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) 437 { 438 if (map->objcg) 439 return get_mem_cgroup_from_objcg(map->objcg); 440 441 return root_mem_cgroup; 442 } 443 444 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, 445 int node) 446 { 447 struct mem_cgroup *memcg, *old_memcg; 448 void *ptr; 449 450 memcg = bpf_map_get_memcg(map); 451 old_memcg = set_active_memcg(memcg); 452 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); 453 set_active_memcg(old_memcg); 454 mem_cgroup_put(memcg); 455 456 return ptr; 457 } 458 459 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) 460 { 461 struct mem_cgroup *memcg, *old_memcg; 462 void *ptr; 463 464 memcg = bpf_map_get_memcg(map); 465 old_memcg = set_active_memcg(memcg); 466 ptr = kzalloc(size, flags | __GFP_ACCOUNT); 467 set_active_memcg(old_memcg); 468 mem_cgroup_put(memcg); 469 470 return ptr; 471 } 472 473 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, 474 size_t align, gfp_t flags) 475 { 476 struct mem_cgroup *memcg, *old_memcg; 477 void __percpu *ptr; 478 479 memcg = bpf_map_get_memcg(map); 480 old_memcg = set_active_memcg(memcg); 481 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); 482 set_active_memcg(old_memcg); 483 mem_cgroup_put(memcg); 484 485 return ptr; 486 } 487 488 #else 489 static void bpf_map_save_memcg(struct bpf_map *map) 490 { 491 } 492 493 static void bpf_map_release_memcg(struct bpf_map *map) 494 { 495 } 496 #endif 497 498 static int btf_field_cmp(const void *a, const void *b) 499 { 500 const struct btf_field *f1 = a, *f2 = b; 501 502 if (f1->offset < f2->offset) 503 return -1; 504 else if (f1->offset > f2->offset) 505 return 1; 506 return 0; 507 } 508 509 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 510 enum btf_field_type type) 511 { 512 struct btf_field *field; 513 514 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & type)) 515 return NULL; 516 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 517 if (!field || !(field->type & type)) 518 return NULL; 519 return field; 520 } 521 522 void btf_record_free(struct btf_record *rec) 523 { 524 int i; 525 526 if (IS_ERR_OR_NULL(rec)) 527 return; 528 for (i = 0; i < rec->cnt; i++) { 529 switch (rec->fields[i].type) { 530 case BPF_SPIN_LOCK: 531 case BPF_TIMER: 532 break; 533 case BPF_KPTR_UNREF: 534 case BPF_KPTR_REF: 535 if (rec->fields[i].kptr.module) 536 module_put(rec->fields[i].kptr.module); 537 btf_put(rec->fields[i].kptr.btf); 538 break; 539 case BPF_LIST_HEAD: 540 case BPF_LIST_NODE: 541 /* Nothing to release for bpf_list_head */ 542 break; 543 default: 544 WARN_ON_ONCE(1); 545 continue; 546 } 547 } 548 kfree(rec); 549 } 550 551 void bpf_map_free_record(struct bpf_map *map) 552 { 553 btf_record_free(map->record); 554 map->record = NULL; 555 } 556 557 struct btf_record *btf_record_dup(const struct btf_record *rec) 558 { 559 const struct btf_field *fields; 560 struct btf_record *new_rec; 561 int ret, size, i; 562 563 if (IS_ERR_OR_NULL(rec)) 564 return NULL; 565 size = offsetof(struct btf_record, fields[rec->cnt]); 566 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 567 if (!new_rec) 568 return ERR_PTR(-ENOMEM); 569 /* Do a deep copy of the btf_record */ 570 fields = rec->fields; 571 new_rec->cnt = 0; 572 for (i = 0; i < rec->cnt; i++) { 573 switch (fields[i].type) { 574 case BPF_SPIN_LOCK: 575 case BPF_TIMER: 576 break; 577 case BPF_KPTR_UNREF: 578 case BPF_KPTR_REF: 579 btf_get(fields[i].kptr.btf); 580 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 581 ret = -ENXIO; 582 goto free; 583 } 584 break; 585 case BPF_LIST_HEAD: 586 case BPF_LIST_NODE: 587 /* Nothing to acquire for bpf_list_head */ 588 break; 589 default: 590 ret = -EFAULT; 591 WARN_ON_ONCE(1); 592 goto free; 593 } 594 new_rec->cnt++; 595 } 596 return new_rec; 597 free: 598 btf_record_free(new_rec); 599 return ERR_PTR(ret); 600 } 601 602 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 603 { 604 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 605 int size; 606 607 if (!a_has_fields && !b_has_fields) 608 return true; 609 if (a_has_fields != b_has_fields) 610 return false; 611 if (rec_a->cnt != rec_b->cnt) 612 return false; 613 size = offsetof(struct btf_record, fields[rec_a->cnt]); 614 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 615 * members are zeroed out. So memcmp is safe to do without worrying 616 * about padding/unused fields. 617 * 618 * While spin_lock, timer, and kptr have no relation to map BTF, 619 * list_head metadata is specific to map BTF, the btf and value_rec 620 * members in particular. btf is the map BTF, while value_rec points to 621 * btf_record in that map BTF. 622 * 623 * So while by default, we don't rely on the map BTF (which the records 624 * were parsed from) matching for both records, which is not backwards 625 * compatible, in case list_head is part of it, we implicitly rely on 626 * that by way of depending on memcmp succeeding for it. 627 */ 628 return !memcmp(rec_a, rec_b, size); 629 } 630 631 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 632 { 633 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 634 return; 635 bpf_timer_cancel_and_free(obj + rec->timer_off); 636 } 637 638 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 639 { 640 const struct btf_field *fields; 641 int i; 642 643 if (IS_ERR_OR_NULL(rec)) 644 return; 645 fields = rec->fields; 646 for (i = 0; i < rec->cnt; i++) { 647 const struct btf_field *field = &fields[i]; 648 void *field_ptr = obj + field->offset; 649 650 switch (fields[i].type) { 651 case BPF_SPIN_LOCK: 652 break; 653 case BPF_TIMER: 654 bpf_timer_cancel_and_free(field_ptr); 655 break; 656 case BPF_KPTR_UNREF: 657 WRITE_ONCE(*(u64 *)field_ptr, 0); 658 break; 659 case BPF_KPTR_REF: 660 field->kptr.dtor((void *)xchg((unsigned long *)field_ptr, 0)); 661 break; 662 case BPF_LIST_HEAD: 663 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 664 continue; 665 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 666 break; 667 case BPF_LIST_NODE: 668 break; 669 default: 670 WARN_ON_ONCE(1); 671 continue; 672 } 673 } 674 } 675 676 /* called from workqueue */ 677 static void bpf_map_free_deferred(struct work_struct *work) 678 { 679 struct bpf_map *map = container_of(work, struct bpf_map, work); 680 struct btf_field_offs *foffs = map->field_offs; 681 struct btf_record *rec = map->record; 682 683 security_bpf_map_free(map); 684 bpf_map_release_memcg(map); 685 /* implementation dependent freeing */ 686 map->ops->map_free(map); 687 /* Delay freeing of field_offs and btf_record for maps, as map_free 688 * callback usually needs access to them. It is better to do it here 689 * than require each callback to do the free itself manually. 690 * 691 * Note that the btf_record stashed in map->inner_map_meta->record was 692 * already freed using the map_free callback for map in map case which 693 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 694 * template bpf_map struct used during verification. 695 */ 696 kfree(foffs); 697 btf_record_free(rec); 698 } 699 700 static void bpf_map_put_uref(struct bpf_map *map) 701 { 702 if (atomic64_dec_and_test(&map->usercnt)) { 703 if (map->ops->map_release_uref) 704 map->ops->map_release_uref(map); 705 } 706 } 707 708 /* decrement map refcnt and schedule it for freeing via workqueue 709 * (unrelying map implementation ops->map_free() might sleep) 710 */ 711 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock) 712 { 713 if (atomic64_dec_and_test(&map->refcnt)) { 714 /* bpf_map_free_id() must be called first */ 715 bpf_map_free_id(map, do_idr_lock); 716 btf_put(map->btf); 717 INIT_WORK(&map->work, bpf_map_free_deferred); 718 /* Avoid spawning kworkers, since they all might contend 719 * for the same mutex like slab_mutex. 720 */ 721 queue_work(system_unbound_wq, &map->work); 722 } 723 } 724 725 void bpf_map_put(struct bpf_map *map) 726 { 727 __bpf_map_put(map, true); 728 } 729 EXPORT_SYMBOL_GPL(bpf_map_put); 730 731 void bpf_map_put_with_uref(struct bpf_map *map) 732 { 733 bpf_map_put_uref(map); 734 bpf_map_put(map); 735 } 736 737 static int bpf_map_release(struct inode *inode, struct file *filp) 738 { 739 struct bpf_map *map = filp->private_data; 740 741 if (map->ops->map_release) 742 map->ops->map_release(map, filp); 743 744 bpf_map_put_with_uref(map); 745 return 0; 746 } 747 748 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 749 { 750 fmode_t mode = f.file->f_mode; 751 752 /* Our file permissions may have been overridden by global 753 * map permissions facing syscall side. 754 */ 755 if (READ_ONCE(map->frozen)) 756 mode &= ~FMODE_CAN_WRITE; 757 return mode; 758 } 759 760 #ifdef CONFIG_PROC_FS 761 /* Provides an approximation of the map's memory footprint. 762 * Used only to provide a backward compatibility and display 763 * a reasonable "memlock" info. 764 */ 765 static unsigned long bpf_map_memory_footprint(const struct bpf_map *map) 766 { 767 unsigned long size; 768 769 size = round_up(map->key_size + bpf_map_value_size(map), 8); 770 771 return round_up(map->max_entries * size, PAGE_SIZE); 772 } 773 774 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 775 { 776 struct bpf_map *map = filp->private_data; 777 u32 type = 0, jited = 0; 778 779 if (map_type_contains_progs(map)) { 780 spin_lock(&map->owner.lock); 781 type = map->owner.type; 782 jited = map->owner.jited; 783 spin_unlock(&map->owner.lock); 784 } 785 786 seq_printf(m, 787 "map_type:\t%u\n" 788 "key_size:\t%u\n" 789 "value_size:\t%u\n" 790 "max_entries:\t%u\n" 791 "map_flags:\t%#x\n" 792 "map_extra:\t%#llx\n" 793 "memlock:\t%lu\n" 794 "map_id:\t%u\n" 795 "frozen:\t%u\n", 796 map->map_type, 797 map->key_size, 798 map->value_size, 799 map->max_entries, 800 map->map_flags, 801 (unsigned long long)map->map_extra, 802 bpf_map_memory_footprint(map), 803 map->id, 804 READ_ONCE(map->frozen)); 805 if (type) { 806 seq_printf(m, "owner_prog_type:\t%u\n", type); 807 seq_printf(m, "owner_jited:\t%u\n", jited); 808 } 809 } 810 #endif 811 812 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 813 loff_t *ppos) 814 { 815 /* We need this handler such that alloc_file() enables 816 * f_mode with FMODE_CAN_READ. 817 */ 818 return -EINVAL; 819 } 820 821 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 822 size_t siz, loff_t *ppos) 823 { 824 /* We need this handler such that alloc_file() enables 825 * f_mode with FMODE_CAN_WRITE. 826 */ 827 return -EINVAL; 828 } 829 830 /* called for any extra memory-mapped regions (except initial) */ 831 static void bpf_map_mmap_open(struct vm_area_struct *vma) 832 { 833 struct bpf_map *map = vma->vm_file->private_data; 834 835 if (vma->vm_flags & VM_MAYWRITE) 836 bpf_map_write_active_inc(map); 837 } 838 839 /* called for all unmapped memory region (including initial) */ 840 static void bpf_map_mmap_close(struct vm_area_struct *vma) 841 { 842 struct bpf_map *map = vma->vm_file->private_data; 843 844 if (vma->vm_flags & VM_MAYWRITE) 845 bpf_map_write_active_dec(map); 846 } 847 848 static const struct vm_operations_struct bpf_map_default_vmops = { 849 .open = bpf_map_mmap_open, 850 .close = bpf_map_mmap_close, 851 }; 852 853 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 854 { 855 struct bpf_map *map = filp->private_data; 856 int err; 857 858 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 859 return -ENOTSUPP; 860 861 if (!(vma->vm_flags & VM_SHARED)) 862 return -EINVAL; 863 864 mutex_lock(&map->freeze_mutex); 865 866 if (vma->vm_flags & VM_WRITE) { 867 if (map->frozen) { 868 err = -EPERM; 869 goto out; 870 } 871 /* map is meant to be read-only, so do not allow mapping as 872 * writable, because it's possible to leak a writable page 873 * reference and allows user-space to still modify it after 874 * freezing, while verifier will assume contents do not change 875 */ 876 if (map->map_flags & BPF_F_RDONLY_PROG) { 877 err = -EACCES; 878 goto out; 879 } 880 } 881 882 /* set default open/close callbacks */ 883 vma->vm_ops = &bpf_map_default_vmops; 884 vma->vm_private_data = map; 885 vma->vm_flags &= ~VM_MAYEXEC; 886 if (!(vma->vm_flags & VM_WRITE)) 887 /* disallow re-mapping with PROT_WRITE */ 888 vma->vm_flags &= ~VM_MAYWRITE; 889 890 err = map->ops->map_mmap(map, vma); 891 if (err) 892 goto out; 893 894 if (vma->vm_flags & VM_MAYWRITE) 895 bpf_map_write_active_inc(map); 896 out: 897 mutex_unlock(&map->freeze_mutex); 898 return err; 899 } 900 901 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 902 { 903 struct bpf_map *map = filp->private_data; 904 905 if (map->ops->map_poll) 906 return map->ops->map_poll(map, filp, pts); 907 908 return EPOLLERR; 909 } 910 911 const struct file_operations bpf_map_fops = { 912 #ifdef CONFIG_PROC_FS 913 .show_fdinfo = bpf_map_show_fdinfo, 914 #endif 915 .release = bpf_map_release, 916 .read = bpf_dummy_read, 917 .write = bpf_dummy_write, 918 .mmap = bpf_map_mmap, 919 .poll = bpf_map_poll, 920 }; 921 922 int bpf_map_new_fd(struct bpf_map *map, int flags) 923 { 924 int ret; 925 926 ret = security_bpf_map(map, OPEN_FMODE(flags)); 927 if (ret < 0) 928 return ret; 929 930 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 931 flags | O_CLOEXEC); 932 } 933 934 int bpf_get_file_flag(int flags) 935 { 936 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 937 return -EINVAL; 938 if (flags & BPF_F_RDONLY) 939 return O_RDONLY; 940 if (flags & BPF_F_WRONLY) 941 return O_WRONLY; 942 return O_RDWR; 943 } 944 945 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 946 #define CHECK_ATTR(CMD) \ 947 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 948 sizeof(attr->CMD##_LAST_FIELD), 0, \ 949 sizeof(*attr) - \ 950 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 951 sizeof(attr->CMD##_LAST_FIELD)) != NULL 952 953 /* dst and src must have at least "size" number of bytes. 954 * Return strlen on success and < 0 on error. 955 */ 956 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 957 { 958 const char *end = src + size; 959 const char *orig_src = src; 960 961 memset(dst, 0, size); 962 /* Copy all isalnum(), '_' and '.' chars. */ 963 while (src < end && *src) { 964 if (!isalnum(*src) && 965 *src != '_' && *src != '.') 966 return -EINVAL; 967 *dst++ = *src++; 968 } 969 970 /* No '\0' found in "size" number of bytes */ 971 if (src == end) 972 return -EINVAL; 973 974 return src - orig_src; 975 } 976 977 int map_check_no_btf(const struct bpf_map *map, 978 const struct btf *btf, 979 const struct btf_type *key_type, 980 const struct btf_type *value_type) 981 { 982 return -ENOTSUPP; 983 } 984 985 static int map_check_btf(struct bpf_map *map, const struct btf *btf, 986 u32 btf_key_id, u32 btf_value_id) 987 { 988 const struct btf_type *key_type, *value_type; 989 u32 key_size, value_size; 990 int ret = 0; 991 992 /* Some maps allow key to be unspecified. */ 993 if (btf_key_id) { 994 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 995 if (!key_type || key_size != map->key_size) 996 return -EINVAL; 997 } else { 998 key_type = btf_type_by_id(btf, 0); 999 if (!map->ops->map_check_btf) 1000 return -EINVAL; 1001 } 1002 1003 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1004 if (!value_type || value_size != map->value_size) 1005 return -EINVAL; 1006 1007 map->record = btf_parse_fields(btf, value_type, 1008 BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD, 1009 map->value_size); 1010 if (!IS_ERR_OR_NULL(map->record)) { 1011 int i; 1012 1013 if (!bpf_capable()) { 1014 ret = -EPERM; 1015 goto free_map_tab; 1016 } 1017 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1018 ret = -EACCES; 1019 goto free_map_tab; 1020 } 1021 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1022 switch (map->record->field_mask & (1 << i)) { 1023 case 0: 1024 continue; 1025 case BPF_SPIN_LOCK: 1026 if (map->map_type != BPF_MAP_TYPE_HASH && 1027 map->map_type != BPF_MAP_TYPE_ARRAY && 1028 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1029 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1030 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1031 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1032 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1033 ret = -EOPNOTSUPP; 1034 goto free_map_tab; 1035 } 1036 break; 1037 case BPF_TIMER: 1038 if (map->map_type != BPF_MAP_TYPE_HASH && 1039 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1040 map->map_type != BPF_MAP_TYPE_ARRAY) { 1041 ret = -EOPNOTSUPP; 1042 goto free_map_tab; 1043 } 1044 break; 1045 case BPF_KPTR_UNREF: 1046 case BPF_KPTR_REF: 1047 if (map->map_type != BPF_MAP_TYPE_HASH && 1048 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1049 map->map_type != BPF_MAP_TYPE_ARRAY && 1050 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY) { 1051 ret = -EOPNOTSUPP; 1052 goto free_map_tab; 1053 } 1054 break; 1055 case BPF_LIST_HEAD: 1056 if (map->map_type != BPF_MAP_TYPE_HASH && 1057 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1058 map->map_type != BPF_MAP_TYPE_ARRAY) { 1059 ret = -EOPNOTSUPP; 1060 goto free_map_tab; 1061 } 1062 break; 1063 default: 1064 /* Fail if map_type checks are missing for a field type */ 1065 ret = -EOPNOTSUPP; 1066 goto free_map_tab; 1067 } 1068 } 1069 } 1070 1071 ret = btf_check_and_fixup_fields(btf, map->record); 1072 if (ret < 0) 1073 goto free_map_tab; 1074 1075 if (map->ops->map_check_btf) { 1076 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1077 if (ret < 0) 1078 goto free_map_tab; 1079 } 1080 1081 return ret; 1082 free_map_tab: 1083 bpf_map_free_record(map); 1084 return ret; 1085 } 1086 1087 #define BPF_MAP_CREATE_LAST_FIELD map_extra 1088 /* called via syscall */ 1089 static int map_create(union bpf_attr *attr) 1090 { 1091 int numa_node = bpf_map_attr_numa_node(attr); 1092 struct btf_field_offs *foffs; 1093 struct bpf_map *map; 1094 int f_flags; 1095 int err; 1096 1097 err = CHECK_ATTR(BPF_MAP_CREATE); 1098 if (err) 1099 return -EINVAL; 1100 1101 if (attr->btf_vmlinux_value_type_id) { 1102 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || 1103 attr->btf_key_type_id || attr->btf_value_type_id) 1104 return -EINVAL; 1105 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1106 return -EINVAL; 1107 } 1108 1109 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1110 attr->map_extra != 0) 1111 return -EINVAL; 1112 1113 f_flags = bpf_get_file_flag(attr->map_flags); 1114 if (f_flags < 0) 1115 return f_flags; 1116 1117 if (numa_node != NUMA_NO_NODE && 1118 ((unsigned int)numa_node >= nr_node_ids || 1119 !node_online(numa_node))) 1120 return -EINVAL; 1121 1122 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1123 map = find_and_alloc_map(attr); 1124 if (IS_ERR(map)) 1125 return PTR_ERR(map); 1126 1127 err = bpf_obj_name_cpy(map->name, attr->map_name, 1128 sizeof(attr->map_name)); 1129 if (err < 0) 1130 goto free_map; 1131 1132 atomic64_set(&map->refcnt, 1); 1133 atomic64_set(&map->usercnt, 1); 1134 mutex_init(&map->freeze_mutex); 1135 spin_lock_init(&map->owner.lock); 1136 1137 if (attr->btf_key_type_id || attr->btf_value_type_id || 1138 /* Even the map's value is a kernel's struct, 1139 * the bpf_prog.o must have BTF to begin with 1140 * to figure out the corresponding kernel's 1141 * counter part. Thus, attr->btf_fd has 1142 * to be valid also. 1143 */ 1144 attr->btf_vmlinux_value_type_id) { 1145 struct btf *btf; 1146 1147 btf = btf_get_by_fd(attr->btf_fd); 1148 if (IS_ERR(btf)) { 1149 err = PTR_ERR(btf); 1150 goto free_map; 1151 } 1152 if (btf_is_kernel(btf)) { 1153 btf_put(btf); 1154 err = -EACCES; 1155 goto free_map; 1156 } 1157 map->btf = btf; 1158 1159 if (attr->btf_value_type_id) { 1160 err = map_check_btf(map, btf, attr->btf_key_type_id, 1161 attr->btf_value_type_id); 1162 if (err) 1163 goto free_map; 1164 } 1165 1166 map->btf_key_type_id = attr->btf_key_type_id; 1167 map->btf_value_type_id = attr->btf_value_type_id; 1168 map->btf_vmlinux_value_type_id = 1169 attr->btf_vmlinux_value_type_id; 1170 } 1171 1172 1173 foffs = btf_parse_field_offs(map->record); 1174 if (IS_ERR(foffs)) { 1175 err = PTR_ERR(foffs); 1176 goto free_map; 1177 } 1178 map->field_offs = foffs; 1179 1180 err = security_bpf_map_alloc(map); 1181 if (err) 1182 goto free_map_field_offs; 1183 1184 err = bpf_map_alloc_id(map); 1185 if (err) 1186 goto free_map_sec; 1187 1188 bpf_map_save_memcg(map); 1189 1190 err = bpf_map_new_fd(map, f_flags); 1191 if (err < 0) { 1192 /* failed to allocate fd. 1193 * bpf_map_put_with_uref() is needed because the above 1194 * bpf_map_alloc_id() has published the map 1195 * to the userspace and the userspace may 1196 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1197 */ 1198 bpf_map_put_with_uref(map); 1199 return err; 1200 } 1201 1202 return err; 1203 1204 free_map_sec: 1205 security_bpf_map_free(map); 1206 free_map_field_offs: 1207 kfree(map->field_offs); 1208 free_map: 1209 btf_put(map->btf); 1210 map->ops->map_free(map); 1211 return err; 1212 } 1213 1214 /* if error is returned, fd is released. 1215 * On success caller should complete fd access with matching fdput() 1216 */ 1217 struct bpf_map *__bpf_map_get(struct fd f) 1218 { 1219 if (!f.file) 1220 return ERR_PTR(-EBADF); 1221 if (f.file->f_op != &bpf_map_fops) { 1222 fdput(f); 1223 return ERR_PTR(-EINVAL); 1224 } 1225 1226 return f.file->private_data; 1227 } 1228 1229 void bpf_map_inc(struct bpf_map *map) 1230 { 1231 atomic64_inc(&map->refcnt); 1232 } 1233 EXPORT_SYMBOL_GPL(bpf_map_inc); 1234 1235 void bpf_map_inc_with_uref(struct bpf_map *map) 1236 { 1237 atomic64_inc(&map->refcnt); 1238 atomic64_inc(&map->usercnt); 1239 } 1240 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1241 1242 struct bpf_map *bpf_map_get(u32 ufd) 1243 { 1244 struct fd f = fdget(ufd); 1245 struct bpf_map *map; 1246 1247 map = __bpf_map_get(f); 1248 if (IS_ERR(map)) 1249 return map; 1250 1251 bpf_map_inc(map); 1252 fdput(f); 1253 1254 return map; 1255 } 1256 EXPORT_SYMBOL(bpf_map_get); 1257 1258 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1259 { 1260 struct fd f = fdget(ufd); 1261 struct bpf_map *map; 1262 1263 map = __bpf_map_get(f); 1264 if (IS_ERR(map)) 1265 return map; 1266 1267 bpf_map_inc_with_uref(map); 1268 fdput(f); 1269 1270 return map; 1271 } 1272 1273 /* map_idr_lock should have been held */ 1274 static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1275 { 1276 int refold; 1277 1278 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1279 if (!refold) 1280 return ERR_PTR(-ENOENT); 1281 if (uref) 1282 atomic64_inc(&map->usercnt); 1283 1284 return map; 1285 } 1286 1287 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1288 { 1289 spin_lock_bh(&map_idr_lock); 1290 map = __bpf_map_inc_not_zero(map, false); 1291 spin_unlock_bh(&map_idr_lock); 1292 1293 return map; 1294 } 1295 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1296 1297 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) 1298 { 1299 return -ENOTSUPP; 1300 } 1301 1302 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1303 { 1304 if (key_size) 1305 return vmemdup_user(ukey, key_size); 1306 1307 if (ukey) 1308 return ERR_PTR(-EINVAL); 1309 1310 return NULL; 1311 } 1312 1313 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1314 { 1315 if (key_size) 1316 return kvmemdup_bpfptr(ukey, key_size); 1317 1318 if (!bpfptr_is_null(ukey)) 1319 return ERR_PTR(-EINVAL); 1320 1321 return NULL; 1322 } 1323 1324 /* last field in 'union bpf_attr' used by this command */ 1325 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1326 1327 static int map_lookup_elem(union bpf_attr *attr) 1328 { 1329 void __user *ukey = u64_to_user_ptr(attr->key); 1330 void __user *uvalue = u64_to_user_ptr(attr->value); 1331 int ufd = attr->map_fd; 1332 struct bpf_map *map; 1333 void *key, *value; 1334 u32 value_size; 1335 struct fd f; 1336 int err; 1337 1338 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1339 return -EINVAL; 1340 1341 if (attr->flags & ~BPF_F_LOCK) 1342 return -EINVAL; 1343 1344 f = fdget(ufd); 1345 map = __bpf_map_get(f); 1346 if (IS_ERR(map)) 1347 return PTR_ERR(map); 1348 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1349 err = -EPERM; 1350 goto err_put; 1351 } 1352 1353 if ((attr->flags & BPF_F_LOCK) && 1354 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1355 err = -EINVAL; 1356 goto err_put; 1357 } 1358 1359 key = __bpf_copy_key(ukey, map->key_size); 1360 if (IS_ERR(key)) { 1361 err = PTR_ERR(key); 1362 goto err_put; 1363 } 1364 1365 value_size = bpf_map_value_size(map); 1366 1367 err = -ENOMEM; 1368 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1369 if (!value) 1370 goto free_key; 1371 1372 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1373 if (copy_from_user(value, uvalue, value_size)) 1374 err = -EFAULT; 1375 else 1376 err = bpf_map_copy_value(map, key, value, attr->flags); 1377 goto free_value; 1378 } 1379 1380 err = bpf_map_copy_value(map, key, value, attr->flags); 1381 if (err) 1382 goto free_value; 1383 1384 err = -EFAULT; 1385 if (copy_to_user(uvalue, value, value_size) != 0) 1386 goto free_value; 1387 1388 err = 0; 1389 1390 free_value: 1391 kvfree(value); 1392 free_key: 1393 kvfree(key); 1394 err_put: 1395 fdput(f); 1396 return err; 1397 } 1398 1399 1400 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1401 1402 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1403 { 1404 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1405 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1406 int ufd = attr->map_fd; 1407 struct bpf_map *map; 1408 void *key, *value; 1409 u32 value_size; 1410 struct fd f; 1411 int err; 1412 1413 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1414 return -EINVAL; 1415 1416 f = fdget(ufd); 1417 map = __bpf_map_get(f); 1418 if (IS_ERR(map)) 1419 return PTR_ERR(map); 1420 bpf_map_write_active_inc(map); 1421 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1422 err = -EPERM; 1423 goto err_put; 1424 } 1425 1426 if ((attr->flags & BPF_F_LOCK) && 1427 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1428 err = -EINVAL; 1429 goto err_put; 1430 } 1431 1432 key = ___bpf_copy_key(ukey, map->key_size); 1433 if (IS_ERR(key)) { 1434 err = PTR_ERR(key); 1435 goto err_put; 1436 } 1437 1438 value_size = bpf_map_value_size(map); 1439 value = kvmemdup_bpfptr(uvalue, value_size); 1440 if (IS_ERR(value)) { 1441 err = PTR_ERR(value); 1442 goto free_key; 1443 } 1444 1445 err = bpf_map_update_value(map, f.file, key, value, attr->flags); 1446 1447 kvfree(value); 1448 free_key: 1449 kvfree(key); 1450 err_put: 1451 bpf_map_write_active_dec(map); 1452 fdput(f); 1453 return err; 1454 } 1455 1456 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1457 1458 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1459 { 1460 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1461 int ufd = attr->map_fd; 1462 struct bpf_map *map; 1463 struct fd f; 1464 void *key; 1465 int err; 1466 1467 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1468 return -EINVAL; 1469 1470 f = fdget(ufd); 1471 map = __bpf_map_get(f); 1472 if (IS_ERR(map)) 1473 return PTR_ERR(map); 1474 bpf_map_write_active_inc(map); 1475 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1476 err = -EPERM; 1477 goto err_put; 1478 } 1479 1480 key = ___bpf_copy_key(ukey, map->key_size); 1481 if (IS_ERR(key)) { 1482 err = PTR_ERR(key); 1483 goto err_put; 1484 } 1485 1486 if (bpf_map_is_dev_bound(map)) { 1487 err = bpf_map_offload_delete_elem(map, key); 1488 goto out; 1489 } else if (IS_FD_PROG_ARRAY(map) || 1490 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1491 /* These maps require sleepable context */ 1492 err = map->ops->map_delete_elem(map, key); 1493 goto out; 1494 } 1495 1496 bpf_disable_instrumentation(); 1497 rcu_read_lock(); 1498 err = map->ops->map_delete_elem(map, key); 1499 rcu_read_unlock(); 1500 bpf_enable_instrumentation(); 1501 maybe_wait_bpf_programs(map); 1502 out: 1503 kvfree(key); 1504 err_put: 1505 bpf_map_write_active_dec(map); 1506 fdput(f); 1507 return err; 1508 } 1509 1510 /* last field in 'union bpf_attr' used by this command */ 1511 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1512 1513 static int map_get_next_key(union bpf_attr *attr) 1514 { 1515 void __user *ukey = u64_to_user_ptr(attr->key); 1516 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1517 int ufd = attr->map_fd; 1518 struct bpf_map *map; 1519 void *key, *next_key; 1520 struct fd f; 1521 int err; 1522 1523 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1524 return -EINVAL; 1525 1526 f = fdget(ufd); 1527 map = __bpf_map_get(f); 1528 if (IS_ERR(map)) 1529 return PTR_ERR(map); 1530 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1531 err = -EPERM; 1532 goto err_put; 1533 } 1534 1535 if (ukey) { 1536 key = __bpf_copy_key(ukey, map->key_size); 1537 if (IS_ERR(key)) { 1538 err = PTR_ERR(key); 1539 goto err_put; 1540 } 1541 } else { 1542 key = NULL; 1543 } 1544 1545 err = -ENOMEM; 1546 next_key = kvmalloc(map->key_size, GFP_USER); 1547 if (!next_key) 1548 goto free_key; 1549 1550 if (bpf_map_is_dev_bound(map)) { 1551 err = bpf_map_offload_get_next_key(map, key, next_key); 1552 goto out; 1553 } 1554 1555 rcu_read_lock(); 1556 err = map->ops->map_get_next_key(map, key, next_key); 1557 rcu_read_unlock(); 1558 out: 1559 if (err) 1560 goto free_next_key; 1561 1562 err = -EFAULT; 1563 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1564 goto free_next_key; 1565 1566 err = 0; 1567 1568 free_next_key: 1569 kvfree(next_key); 1570 free_key: 1571 kvfree(key); 1572 err_put: 1573 fdput(f); 1574 return err; 1575 } 1576 1577 int generic_map_delete_batch(struct bpf_map *map, 1578 const union bpf_attr *attr, 1579 union bpf_attr __user *uattr) 1580 { 1581 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1582 u32 cp, max_count; 1583 int err = 0; 1584 void *key; 1585 1586 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1587 return -EINVAL; 1588 1589 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1590 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1591 return -EINVAL; 1592 } 1593 1594 max_count = attr->batch.count; 1595 if (!max_count) 1596 return 0; 1597 1598 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1599 if (!key) 1600 return -ENOMEM; 1601 1602 for (cp = 0; cp < max_count; cp++) { 1603 err = -EFAULT; 1604 if (copy_from_user(key, keys + cp * map->key_size, 1605 map->key_size)) 1606 break; 1607 1608 if (bpf_map_is_dev_bound(map)) { 1609 err = bpf_map_offload_delete_elem(map, key); 1610 break; 1611 } 1612 1613 bpf_disable_instrumentation(); 1614 rcu_read_lock(); 1615 err = map->ops->map_delete_elem(map, key); 1616 rcu_read_unlock(); 1617 bpf_enable_instrumentation(); 1618 if (err) 1619 break; 1620 cond_resched(); 1621 } 1622 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1623 err = -EFAULT; 1624 1625 kvfree(key); 1626 1627 maybe_wait_bpf_programs(map); 1628 return err; 1629 } 1630 1631 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 1632 const union bpf_attr *attr, 1633 union bpf_attr __user *uattr) 1634 { 1635 void __user *values = u64_to_user_ptr(attr->batch.values); 1636 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1637 u32 value_size, cp, max_count; 1638 void *key, *value; 1639 int err = 0; 1640 1641 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1642 return -EINVAL; 1643 1644 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1645 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1646 return -EINVAL; 1647 } 1648 1649 value_size = bpf_map_value_size(map); 1650 1651 max_count = attr->batch.count; 1652 if (!max_count) 1653 return 0; 1654 1655 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1656 if (!key) 1657 return -ENOMEM; 1658 1659 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1660 if (!value) { 1661 kvfree(key); 1662 return -ENOMEM; 1663 } 1664 1665 for (cp = 0; cp < max_count; cp++) { 1666 err = -EFAULT; 1667 if (copy_from_user(key, keys + cp * map->key_size, 1668 map->key_size) || 1669 copy_from_user(value, values + cp * value_size, value_size)) 1670 break; 1671 1672 err = bpf_map_update_value(map, map_file, key, value, 1673 attr->batch.elem_flags); 1674 1675 if (err) 1676 break; 1677 cond_resched(); 1678 } 1679 1680 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1681 err = -EFAULT; 1682 1683 kvfree(value); 1684 kvfree(key); 1685 return err; 1686 } 1687 1688 #define MAP_LOOKUP_RETRIES 3 1689 1690 int generic_map_lookup_batch(struct bpf_map *map, 1691 const union bpf_attr *attr, 1692 union bpf_attr __user *uattr) 1693 { 1694 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 1695 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 1696 void __user *values = u64_to_user_ptr(attr->batch.values); 1697 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1698 void *buf, *buf_prevkey, *prev_key, *key, *value; 1699 int err, retry = MAP_LOOKUP_RETRIES; 1700 u32 value_size, cp, max_count; 1701 1702 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1703 return -EINVAL; 1704 1705 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1706 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 1707 return -EINVAL; 1708 1709 value_size = bpf_map_value_size(map); 1710 1711 max_count = attr->batch.count; 1712 if (!max_count) 1713 return 0; 1714 1715 if (put_user(0, &uattr->batch.count)) 1716 return -EFAULT; 1717 1718 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1719 if (!buf_prevkey) 1720 return -ENOMEM; 1721 1722 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 1723 if (!buf) { 1724 kvfree(buf_prevkey); 1725 return -ENOMEM; 1726 } 1727 1728 err = -EFAULT; 1729 prev_key = NULL; 1730 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 1731 goto free_buf; 1732 key = buf; 1733 value = key + map->key_size; 1734 if (ubatch) 1735 prev_key = buf_prevkey; 1736 1737 for (cp = 0; cp < max_count;) { 1738 rcu_read_lock(); 1739 err = map->ops->map_get_next_key(map, prev_key, key); 1740 rcu_read_unlock(); 1741 if (err) 1742 break; 1743 err = bpf_map_copy_value(map, key, value, 1744 attr->batch.elem_flags); 1745 1746 if (err == -ENOENT) { 1747 if (retry) { 1748 retry--; 1749 continue; 1750 } 1751 err = -EINTR; 1752 break; 1753 } 1754 1755 if (err) 1756 goto free_buf; 1757 1758 if (copy_to_user(keys + cp * map->key_size, key, 1759 map->key_size)) { 1760 err = -EFAULT; 1761 goto free_buf; 1762 } 1763 if (copy_to_user(values + cp * value_size, value, value_size)) { 1764 err = -EFAULT; 1765 goto free_buf; 1766 } 1767 1768 if (!prev_key) 1769 prev_key = buf_prevkey; 1770 1771 swap(prev_key, key); 1772 retry = MAP_LOOKUP_RETRIES; 1773 cp++; 1774 cond_resched(); 1775 } 1776 1777 if (err == -EFAULT) 1778 goto free_buf; 1779 1780 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 1781 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 1782 err = -EFAULT; 1783 1784 free_buf: 1785 kvfree(buf_prevkey); 1786 kvfree(buf); 1787 return err; 1788 } 1789 1790 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 1791 1792 static int map_lookup_and_delete_elem(union bpf_attr *attr) 1793 { 1794 void __user *ukey = u64_to_user_ptr(attr->key); 1795 void __user *uvalue = u64_to_user_ptr(attr->value); 1796 int ufd = attr->map_fd; 1797 struct bpf_map *map; 1798 void *key, *value; 1799 u32 value_size; 1800 struct fd f; 1801 int err; 1802 1803 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 1804 return -EINVAL; 1805 1806 if (attr->flags & ~BPF_F_LOCK) 1807 return -EINVAL; 1808 1809 f = fdget(ufd); 1810 map = __bpf_map_get(f); 1811 if (IS_ERR(map)) 1812 return PTR_ERR(map); 1813 bpf_map_write_active_inc(map); 1814 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 1815 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1816 err = -EPERM; 1817 goto err_put; 1818 } 1819 1820 if (attr->flags && 1821 (map->map_type == BPF_MAP_TYPE_QUEUE || 1822 map->map_type == BPF_MAP_TYPE_STACK)) { 1823 err = -EINVAL; 1824 goto err_put; 1825 } 1826 1827 if ((attr->flags & BPF_F_LOCK) && 1828 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1829 err = -EINVAL; 1830 goto err_put; 1831 } 1832 1833 key = __bpf_copy_key(ukey, map->key_size); 1834 if (IS_ERR(key)) { 1835 err = PTR_ERR(key); 1836 goto err_put; 1837 } 1838 1839 value_size = bpf_map_value_size(map); 1840 1841 err = -ENOMEM; 1842 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1843 if (!value) 1844 goto free_key; 1845 1846 err = -ENOTSUPP; 1847 if (map->map_type == BPF_MAP_TYPE_QUEUE || 1848 map->map_type == BPF_MAP_TYPE_STACK) { 1849 err = map->ops->map_pop_elem(map, value); 1850 } else if (map->map_type == BPF_MAP_TYPE_HASH || 1851 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 1852 map->map_type == BPF_MAP_TYPE_LRU_HASH || 1853 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 1854 if (!bpf_map_is_dev_bound(map)) { 1855 bpf_disable_instrumentation(); 1856 rcu_read_lock(); 1857 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 1858 rcu_read_unlock(); 1859 bpf_enable_instrumentation(); 1860 } 1861 } 1862 1863 if (err) 1864 goto free_value; 1865 1866 if (copy_to_user(uvalue, value, value_size) != 0) { 1867 err = -EFAULT; 1868 goto free_value; 1869 } 1870 1871 err = 0; 1872 1873 free_value: 1874 kvfree(value); 1875 free_key: 1876 kvfree(key); 1877 err_put: 1878 bpf_map_write_active_dec(map); 1879 fdput(f); 1880 return err; 1881 } 1882 1883 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 1884 1885 static int map_freeze(const union bpf_attr *attr) 1886 { 1887 int err = 0, ufd = attr->map_fd; 1888 struct bpf_map *map; 1889 struct fd f; 1890 1891 if (CHECK_ATTR(BPF_MAP_FREEZE)) 1892 return -EINVAL; 1893 1894 f = fdget(ufd); 1895 map = __bpf_map_get(f); 1896 if (IS_ERR(map)) 1897 return PTR_ERR(map); 1898 1899 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) { 1900 fdput(f); 1901 return -ENOTSUPP; 1902 } 1903 1904 mutex_lock(&map->freeze_mutex); 1905 if (bpf_map_write_active(map)) { 1906 err = -EBUSY; 1907 goto err_put; 1908 } 1909 if (READ_ONCE(map->frozen)) { 1910 err = -EBUSY; 1911 goto err_put; 1912 } 1913 if (!bpf_capable()) { 1914 err = -EPERM; 1915 goto err_put; 1916 } 1917 1918 WRITE_ONCE(map->frozen, true); 1919 err_put: 1920 mutex_unlock(&map->freeze_mutex); 1921 fdput(f); 1922 return err; 1923 } 1924 1925 static const struct bpf_prog_ops * const bpf_prog_types[] = { 1926 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 1927 [_id] = & _name ## _prog_ops, 1928 #define BPF_MAP_TYPE(_id, _ops) 1929 #define BPF_LINK_TYPE(_id, _name) 1930 #include <linux/bpf_types.h> 1931 #undef BPF_PROG_TYPE 1932 #undef BPF_MAP_TYPE 1933 #undef BPF_LINK_TYPE 1934 }; 1935 1936 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 1937 { 1938 const struct bpf_prog_ops *ops; 1939 1940 if (type >= ARRAY_SIZE(bpf_prog_types)) 1941 return -EINVAL; 1942 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 1943 ops = bpf_prog_types[type]; 1944 if (!ops) 1945 return -EINVAL; 1946 1947 if (!bpf_prog_is_dev_bound(prog->aux)) 1948 prog->aux->ops = ops; 1949 else 1950 prog->aux->ops = &bpf_offload_prog_ops; 1951 prog->type = type; 1952 return 0; 1953 } 1954 1955 enum bpf_audit { 1956 BPF_AUDIT_LOAD, 1957 BPF_AUDIT_UNLOAD, 1958 BPF_AUDIT_MAX, 1959 }; 1960 1961 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 1962 [BPF_AUDIT_LOAD] = "LOAD", 1963 [BPF_AUDIT_UNLOAD] = "UNLOAD", 1964 }; 1965 1966 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 1967 { 1968 struct audit_context *ctx = NULL; 1969 struct audit_buffer *ab; 1970 1971 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 1972 return; 1973 if (audit_enabled == AUDIT_OFF) 1974 return; 1975 if (!in_irq() && !irqs_disabled()) 1976 ctx = audit_context(); 1977 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 1978 if (unlikely(!ab)) 1979 return; 1980 audit_log_format(ab, "prog-id=%u op=%s", 1981 prog->aux->id, bpf_audit_str[op]); 1982 audit_log_end(ab); 1983 } 1984 1985 static int bpf_prog_alloc_id(struct bpf_prog *prog) 1986 { 1987 int id; 1988 1989 idr_preload(GFP_KERNEL); 1990 spin_lock_bh(&prog_idr_lock); 1991 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 1992 if (id > 0) 1993 prog->aux->id = id; 1994 spin_unlock_bh(&prog_idr_lock); 1995 idr_preload_end(); 1996 1997 /* id is in [1, INT_MAX) */ 1998 if (WARN_ON_ONCE(!id)) 1999 return -ENOSPC; 2000 2001 return id > 0 ? 0 : id; 2002 } 2003 2004 void bpf_prog_free_id(struct bpf_prog *prog) 2005 { 2006 unsigned long flags; 2007 2008 /* cBPF to eBPF migrations are currently not in the idr store. 2009 * Offloaded programs are removed from the store when their device 2010 * disappears - even if someone grabs an fd to them they are unusable, 2011 * simply waiting for refcnt to drop to be freed. 2012 */ 2013 if (!prog->aux->id) 2014 return; 2015 2016 spin_lock_irqsave(&prog_idr_lock, flags); 2017 idr_remove(&prog_idr, prog->aux->id); 2018 prog->aux->id = 0; 2019 spin_unlock_irqrestore(&prog_idr_lock, flags); 2020 } 2021 2022 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2023 { 2024 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2025 2026 kvfree(aux->func_info); 2027 kfree(aux->func_info_aux); 2028 free_uid(aux->user); 2029 security_bpf_prog_free(aux); 2030 bpf_prog_free(aux->prog); 2031 } 2032 2033 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2034 { 2035 bpf_prog_kallsyms_del_all(prog); 2036 btf_put(prog->aux->btf); 2037 kvfree(prog->aux->jited_linfo); 2038 kvfree(prog->aux->linfo); 2039 kfree(prog->aux->kfunc_tab); 2040 if (prog->aux->attach_btf) 2041 btf_put(prog->aux->attach_btf); 2042 2043 if (deferred) { 2044 if (prog->aux->sleepable) 2045 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2046 else 2047 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2048 } else { 2049 __bpf_prog_put_rcu(&prog->aux->rcu); 2050 } 2051 } 2052 2053 static void bpf_prog_put_deferred(struct work_struct *work) 2054 { 2055 struct bpf_prog_aux *aux; 2056 struct bpf_prog *prog; 2057 2058 aux = container_of(work, struct bpf_prog_aux, work); 2059 prog = aux->prog; 2060 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2061 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2062 bpf_prog_free_id(prog); 2063 __bpf_prog_put_noref(prog, true); 2064 } 2065 2066 static void __bpf_prog_put(struct bpf_prog *prog) 2067 { 2068 struct bpf_prog_aux *aux = prog->aux; 2069 2070 if (atomic64_dec_and_test(&aux->refcnt)) { 2071 if (in_irq() || irqs_disabled()) { 2072 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2073 schedule_work(&aux->work); 2074 } else { 2075 bpf_prog_put_deferred(&aux->work); 2076 } 2077 } 2078 } 2079 2080 void bpf_prog_put(struct bpf_prog *prog) 2081 { 2082 __bpf_prog_put(prog); 2083 } 2084 EXPORT_SYMBOL_GPL(bpf_prog_put); 2085 2086 static int bpf_prog_release(struct inode *inode, struct file *filp) 2087 { 2088 struct bpf_prog *prog = filp->private_data; 2089 2090 bpf_prog_put(prog); 2091 return 0; 2092 } 2093 2094 struct bpf_prog_kstats { 2095 u64 nsecs; 2096 u64 cnt; 2097 u64 misses; 2098 }; 2099 2100 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2101 { 2102 struct bpf_prog_stats *stats; 2103 unsigned int flags; 2104 2105 stats = this_cpu_ptr(prog->stats); 2106 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2107 u64_stats_inc(&stats->misses); 2108 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2109 } 2110 2111 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2112 struct bpf_prog_kstats *stats) 2113 { 2114 u64 nsecs = 0, cnt = 0, misses = 0; 2115 int cpu; 2116 2117 for_each_possible_cpu(cpu) { 2118 const struct bpf_prog_stats *st; 2119 unsigned int start; 2120 u64 tnsecs, tcnt, tmisses; 2121 2122 st = per_cpu_ptr(prog->stats, cpu); 2123 do { 2124 start = u64_stats_fetch_begin(&st->syncp); 2125 tnsecs = u64_stats_read(&st->nsecs); 2126 tcnt = u64_stats_read(&st->cnt); 2127 tmisses = u64_stats_read(&st->misses); 2128 } while (u64_stats_fetch_retry(&st->syncp, start)); 2129 nsecs += tnsecs; 2130 cnt += tcnt; 2131 misses += tmisses; 2132 } 2133 stats->nsecs = nsecs; 2134 stats->cnt = cnt; 2135 stats->misses = misses; 2136 } 2137 2138 #ifdef CONFIG_PROC_FS 2139 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2140 { 2141 const struct bpf_prog *prog = filp->private_data; 2142 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2143 struct bpf_prog_kstats stats; 2144 2145 bpf_prog_get_stats(prog, &stats); 2146 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2147 seq_printf(m, 2148 "prog_type:\t%u\n" 2149 "prog_jited:\t%u\n" 2150 "prog_tag:\t%s\n" 2151 "memlock:\t%llu\n" 2152 "prog_id:\t%u\n" 2153 "run_time_ns:\t%llu\n" 2154 "run_cnt:\t%llu\n" 2155 "recursion_misses:\t%llu\n" 2156 "verified_insns:\t%u\n", 2157 prog->type, 2158 prog->jited, 2159 prog_tag, 2160 prog->pages * 1ULL << PAGE_SHIFT, 2161 prog->aux->id, 2162 stats.nsecs, 2163 stats.cnt, 2164 stats.misses, 2165 prog->aux->verified_insns); 2166 } 2167 #endif 2168 2169 const struct file_operations bpf_prog_fops = { 2170 #ifdef CONFIG_PROC_FS 2171 .show_fdinfo = bpf_prog_show_fdinfo, 2172 #endif 2173 .release = bpf_prog_release, 2174 .read = bpf_dummy_read, 2175 .write = bpf_dummy_write, 2176 }; 2177 2178 int bpf_prog_new_fd(struct bpf_prog *prog) 2179 { 2180 int ret; 2181 2182 ret = security_bpf_prog(prog); 2183 if (ret < 0) 2184 return ret; 2185 2186 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2187 O_RDWR | O_CLOEXEC); 2188 } 2189 2190 static struct bpf_prog *____bpf_prog_get(struct fd f) 2191 { 2192 if (!f.file) 2193 return ERR_PTR(-EBADF); 2194 if (f.file->f_op != &bpf_prog_fops) { 2195 fdput(f); 2196 return ERR_PTR(-EINVAL); 2197 } 2198 2199 return f.file->private_data; 2200 } 2201 2202 void bpf_prog_add(struct bpf_prog *prog, int i) 2203 { 2204 atomic64_add(i, &prog->aux->refcnt); 2205 } 2206 EXPORT_SYMBOL_GPL(bpf_prog_add); 2207 2208 void bpf_prog_sub(struct bpf_prog *prog, int i) 2209 { 2210 /* Only to be used for undoing previous bpf_prog_add() in some 2211 * error path. We still know that another entity in our call 2212 * path holds a reference to the program, thus atomic_sub() can 2213 * be safely used in such cases! 2214 */ 2215 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2216 } 2217 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2218 2219 void bpf_prog_inc(struct bpf_prog *prog) 2220 { 2221 atomic64_inc(&prog->aux->refcnt); 2222 } 2223 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2224 2225 /* prog_idr_lock should have been held */ 2226 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2227 { 2228 int refold; 2229 2230 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2231 2232 if (!refold) 2233 return ERR_PTR(-ENOENT); 2234 2235 return prog; 2236 } 2237 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2238 2239 bool bpf_prog_get_ok(struct bpf_prog *prog, 2240 enum bpf_prog_type *attach_type, bool attach_drv) 2241 { 2242 /* not an attachment, just a refcount inc, always allow */ 2243 if (!attach_type) 2244 return true; 2245 2246 if (prog->type != *attach_type) 2247 return false; 2248 if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv) 2249 return false; 2250 2251 return true; 2252 } 2253 2254 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2255 bool attach_drv) 2256 { 2257 struct fd f = fdget(ufd); 2258 struct bpf_prog *prog; 2259 2260 prog = ____bpf_prog_get(f); 2261 if (IS_ERR(prog)) 2262 return prog; 2263 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) { 2264 prog = ERR_PTR(-EINVAL); 2265 goto out; 2266 } 2267 2268 bpf_prog_inc(prog); 2269 out: 2270 fdput(f); 2271 return prog; 2272 } 2273 2274 struct bpf_prog *bpf_prog_get(u32 ufd) 2275 { 2276 return __bpf_prog_get(ufd, NULL, false); 2277 } 2278 2279 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2280 bool attach_drv) 2281 { 2282 return __bpf_prog_get(ufd, &type, attach_drv); 2283 } 2284 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2285 2286 /* Initially all BPF programs could be loaded w/o specifying 2287 * expected_attach_type. Later for some of them specifying expected_attach_type 2288 * at load time became required so that program could be validated properly. 2289 * Programs of types that are allowed to be loaded both w/ and w/o (for 2290 * backward compatibility) expected_attach_type, should have the default attach 2291 * type assigned to expected_attach_type for the latter case, so that it can be 2292 * validated later at attach time. 2293 * 2294 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2295 * prog type requires it but has some attach types that have to be backward 2296 * compatible. 2297 */ 2298 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2299 { 2300 switch (attr->prog_type) { 2301 case BPF_PROG_TYPE_CGROUP_SOCK: 2302 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2303 * exist so checking for non-zero is the way to go here. 2304 */ 2305 if (!attr->expected_attach_type) 2306 attr->expected_attach_type = 2307 BPF_CGROUP_INET_SOCK_CREATE; 2308 break; 2309 case BPF_PROG_TYPE_SK_REUSEPORT: 2310 if (!attr->expected_attach_type) 2311 attr->expected_attach_type = 2312 BPF_SK_REUSEPORT_SELECT; 2313 break; 2314 } 2315 } 2316 2317 static int 2318 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2319 enum bpf_attach_type expected_attach_type, 2320 struct btf *attach_btf, u32 btf_id, 2321 struct bpf_prog *dst_prog) 2322 { 2323 if (btf_id) { 2324 if (btf_id > BTF_MAX_TYPE) 2325 return -EINVAL; 2326 2327 if (!attach_btf && !dst_prog) 2328 return -EINVAL; 2329 2330 switch (prog_type) { 2331 case BPF_PROG_TYPE_TRACING: 2332 case BPF_PROG_TYPE_LSM: 2333 case BPF_PROG_TYPE_STRUCT_OPS: 2334 case BPF_PROG_TYPE_EXT: 2335 break; 2336 default: 2337 return -EINVAL; 2338 } 2339 } 2340 2341 if (attach_btf && (!btf_id || dst_prog)) 2342 return -EINVAL; 2343 2344 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2345 prog_type != BPF_PROG_TYPE_EXT) 2346 return -EINVAL; 2347 2348 switch (prog_type) { 2349 case BPF_PROG_TYPE_CGROUP_SOCK: 2350 switch (expected_attach_type) { 2351 case BPF_CGROUP_INET_SOCK_CREATE: 2352 case BPF_CGROUP_INET_SOCK_RELEASE: 2353 case BPF_CGROUP_INET4_POST_BIND: 2354 case BPF_CGROUP_INET6_POST_BIND: 2355 return 0; 2356 default: 2357 return -EINVAL; 2358 } 2359 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2360 switch (expected_attach_type) { 2361 case BPF_CGROUP_INET4_BIND: 2362 case BPF_CGROUP_INET6_BIND: 2363 case BPF_CGROUP_INET4_CONNECT: 2364 case BPF_CGROUP_INET6_CONNECT: 2365 case BPF_CGROUP_INET4_GETPEERNAME: 2366 case BPF_CGROUP_INET6_GETPEERNAME: 2367 case BPF_CGROUP_INET4_GETSOCKNAME: 2368 case BPF_CGROUP_INET6_GETSOCKNAME: 2369 case BPF_CGROUP_UDP4_SENDMSG: 2370 case BPF_CGROUP_UDP6_SENDMSG: 2371 case BPF_CGROUP_UDP4_RECVMSG: 2372 case BPF_CGROUP_UDP6_RECVMSG: 2373 return 0; 2374 default: 2375 return -EINVAL; 2376 } 2377 case BPF_PROG_TYPE_CGROUP_SKB: 2378 switch (expected_attach_type) { 2379 case BPF_CGROUP_INET_INGRESS: 2380 case BPF_CGROUP_INET_EGRESS: 2381 return 0; 2382 default: 2383 return -EINVAL; 2384 } 2385 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2386 switch (expected_attach_type) { 2387 case BPF_CGROUP_SETSOCKOPT: 2388 case BPF_CGROUP_GETSOCKOPT: 2389 return 0; 2390 default: 2391 return -EINVAL; 2392 } 2393 case BPF_PROG_TYPE_SK_LOOKUP: 2394 if (expected_attach_type == BPF_SK_LOOKUP) 2395 return 0; 2396 return -EINVAL; 2397 case BPF_PROG_TYPE_SK_REUSEPORT: 2398 switch (expected_attach_type) { 2399 case BPF_SK_REUSEPORT_SELECT: 2400 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2401 return 0; 2402 default: 2403 return -EINVAL; 2404 } 2405 case BPF_PROG_TYPE_SYSCALL: 2406 case BPF_PROG_TYPE_EXT: 2407 if (expected_attach_type) 2408 return -EINVAL; 2409 fallthrough; 2410 default: 2411 return 0; 2412 } 2413 } 2414 2415 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2416 { 2417 switch (prog_type) { 2418 case BPF_PROG_TYPE_SCHED_CLS: 2419 case BPF_PROG_TYPE_SCHED_ACT: 2420 case BPF_PROG_TYPE_XDP: 2421 case BPF_PROG_TYPE_LWT_IN: 2422 case BPF_PROG_TYPE_LWT_OUT: 2423 case BPF_PROG_TYPE_LWT_XMIT: 2424 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2425 case BPF_PROG_TYPE_SK_SKB: 2426 case BPF_PROG_TYPE_SK_MSG: 2427 case BPF_PROG_TYPE_LIRC_MODE2: 2428 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2429 case BPF_PROG_TYPE_CGROUP_DEVICE: 2430 case BPF_PROG_TYPE_CGROUP_SOCK: 2431 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2432 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2433 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2434 case BPF_PROG_TYPE_SOCK_OPS: 2435 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2436 return true; 2437 case BPF_PROG_TYPE_CGROUP_SKB: 2438 /* always unpriv */ 2439 case BPF_PROG_TYPE_SK_REUSEPORT: 2440 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2441 default: 2442 return false; 2443 } 2444 } 2445 2446 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2447 { 2448 switch (prog_type) { 2449 case BPF_PROG_TYPE_KPROBE: 2450 case BPF_PROG_TYPE_TRACEPOINT: 2451 case BPF_PROG_TYPE_PERF_EVENT: 2452 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2453 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2454 case BPF_PROG_TYPE_TRACING: 2455 case BPF_PROG_TYPE_LSM: 2456 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2457 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2458 return true; 2459 default: 2460 return false; 2461 } 2462 } 2463 2464 /* last field in 'union bpf_attr' used by this command */ 2465 #define BPF_PROG_LOAD_LAST_FIELD core_relo_rec_size 2466 2467 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr) 2468 { 2469 enum bpf_prog_type type = attr->prog_type; 2470 struct bpf_prog *prog, *dst_prog = NULL; 2471 struct btf *attach_btf = NULL; 2472 int err; 2473 char license[128]; 2474 bool is_gpl; 2475 2476 if (CHECK_ATTR(BPF_PROG_LOAD)) 2477 return -EINVAL; 2478 2479 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2480 BPF_F_ANY_ALIGNMENT | 2481 BPF_F_TEST_STATE_FREQ | 2482 BPF_F_SLEEPABLE | 2483 BPF_F_TEST_RND_HI32 | 2484 BPF_F_XDP_HAS_FRAGS)) 2485 return -EINVAL; 2486 2487 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2488 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2489 !bpf_capable()) 2490 return -EPERM; 2491 2492 /* copy eBPF program license from user space */ 2493 if (strncpy_from_bpfptr(license, 2494 make_bpfptr(attr->license, uattr.is_kernel), 2495 sizeof(license) - 1) < 0) 2496 return -EFAULT; 2497 license[sizeof(license) - 1] = 0; 2498 2499 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 2500 is_gpl = license_is_gpl_compatible(license); 2501 2502 if (attr->insn_cnt == 0 || 2503 attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) 2504 return -E2BIG; 2505 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2506 type != BPF_PROG_TYPE_CGROUP_SKB && 2507 !bpf_capable()) 2508 return -EPERM; 2509 2510 if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN)) 2511 return -EPERM; 2512 if (is_perfmon_prog_type(type) && !perfmon_capable()) 2513 return -EPERM; 2514 2515 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 2516 * or btf, we need to check which one it is 2517 */ 2518 if (attr->attach_prog_fd) { 2519 dst_prog = bpf_prog_get(attr->attach_prog_fd); 2520 if (IS_ERR(dst_prog)) { 2521 dst_prog = NULL; 2522 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 2523 if (IS_ERR(attach_btf)) 2524 return -EINVAL; 2525 if (!btf_is_kernel(attach_btf)) { 2526 /* attaching through specifying bpf_prog's BTF 2527 * objects directly might be supported eventually 2528 */ 2529 btf_put(attach_btf); 2530 return -ENOTSUPP; 2531 } 2532 } 2533 } else if (attr->attach_btf_id) { 2534 /* fall back to vmlinux BTF, if BTF type ID is specified */ 2535 attach_btf = bpf_get_btf_vmlinux(); 2536 if (IS_ERR(attach_btf)) 2537 return PTR_ERR(attach_btf); 2538 if (!attach_btf) 2539 return -EINVAL; 2540 btf_get(attach_btf); 2541 } 2542 2543 bpf_prog_load_fixup_attach_type(attr); 2544 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 2545 attach_btf, attr->attach_btf_id, 2546 dst_prog)) { 2547 if (dst_prog) 2548 bpf_prog_put(dst_prog); 2549 if (attach_btf) 2550 btf_put(attach_btf); 2551 return -EINVAL; 2552 } 2553 2554 /* plain bpf_prog allocation */ 2555 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 2556 if (!prog) { 2557 if (dst_prog) 2558 bpf_prog_put(dst_prog); 2559 if (attach_btf) 2560 btf_put(attach_btf); 2561 return -ENOMEM; 2562 } 2563 2564 prog->expected_attach_type = attr->expected_attach_type; 2565 prog->aux->attach_btf = attach_btf; 2566 prog->aux->attach_btf_id = attr->attach_btf_id; 2567 prog->aux->dst_prog = dst_prog; 2568 prog->aux->offload_requested = !!attr->prog_ifindex; 2569 prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE; 2570 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 2571 2572 err = security_bpf_prog_alloc(prog->aux); 2573 if (err) 2574 goto free_prog; 2575 2576 prog->aux->user = get_current_user(); 2577 prog->len = attr->insn_cnt; 2578 2579 err = -EFAULT; 2580 if (copy_from_bpfptr(prog->insns, 2581 make_bpfptr(attr->insns, uattr.is_kernel), 2582 bpf_prog_insn_size(prog)) != 0) 2583 goto free_prog_sec; 2584 2585 prog->orig_prog = NULL; 2586 prog->jited = 0; 2587 2588 atomic64_set(&prog->aux->refcnt, 1); 2589 prog->gpl_compatible = is_gpl ? 1 : 0; 2590 2591 if (bpf_prog_is_dev_bound(prog->aux)) { 2592 err = bpf_prog_offload_init(prog, attr); 2593 if (err) 2594 goto free_prog_sec; 2595 } 2596 2597 /* find program type: socket_filter vs tracing_filter */ 2598 err = find_prog_type(type, prog); 2599 if (err < 0) 2600 goto free_prog_sec; 2601 2602 prog->aux->load_time = ktime_get_boottime_ns(); 2603 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 2604 sizeof(attr->prog_name)); 2605 if (err < 0) 2606 goto free_prog_sec; 2607 2608 /* run eBPF verifier */ 2609 err = bpf_check(&prog, attr, uattr); 2610 if (err < 0) 2611 goto free_used_maps; 2612 2613 prog = bpf_prog_select_runtime(prog, &err); 2614 if (err < 0) 2615 goto free_used_maps; 2616 2617 err = bpf_prog_alloc_id(prog); 2618 if (err) 2619 goto free_used_maps; 2620 2621 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 2622 * effectively publicly exposed. However, retrieving via 2623 * bpf_prog_get_fd_by_id() will take another reference, 2624 * therefore it cannot be gone underneath us. 2625 * 2626 * Only for the time /after/ successful bpf_prog_new_fd() 2627 * and before returning to userspace, we might just hold 2628 * one reference and any parallel close on that fd could 2629 * rip everything out. Hence, below notifications must 2630 * happen before bpf_prog_new_fd(). 2631 * 2632 * Also, any failure handling from this point onwards must 2633 * be using bpf_prog_put() given the program is exposed. 2634 */ 2635 bpf_prog_kallsyms_add(prog); 2636 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 2637 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 2638 2639 err = bpf_prog_new_fd(prog); 2640 if (err < 0) 2641 bpf_prog_put(prog); 2642 return err; 2643 2644 free_used_maps: 2645 /* In case we have subprogs, we need to wait for a grace 2646 * period before we can tear down JIT memory since symbols 2647 * are already exposed under kallsyms. 2648 */ 2649 __bpf_prog_put_noref(prog, prog->aux->func_cnt); 2650 return err; 2651 free_prog_sec: 2652 free_uid(prog->aux->user); 2653 security_bpf_prog_free(prog->aux); 2654 free_prog: 2655 if (prog->aux->attach_btf) 2656 btf_put(prog->aux->attach_btf); 2657 bpf_prog_free(prog); 2658 return err; 2659 } 2660 2661 #define BPF_OBJ_LAST_FIELD file_flags 2662 2663 static int bpf_obj_pin(const union bpf_attr *attr) 2664 { 2665 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0) 2666 return -EINVAL; 2667 2668 return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname)); 2669 } 2670 2671 static int bpf_obj_get(const union bpf_attr *attr) 2672 { 2673 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 2674 attr->file_flags & ~BPF_OBJ_FLAG_MASK) 2675 return -EINVAL; 2676 2677 return bpf_obj_get_user(u64_to_user_ptr(attr->pathname), 2678 attr->file_flags); 2679 } 2680 2681 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 2682 const struct bpf_link_ops *ops, struct bpf_prog *prog) 2683 { 2684 atomic64_set(&link->refcnt, 1); 2685 link->type = type; 2686 link->id = 0; 2687 link->ops = ops; 2688 link->prog = prog; 2689 } 2690 2691 static void bpf_link_free_id(int id) 2692 { 2693 if (!id) 2694 return; 2695 2696 spin_lock_bh(&link_idr_lock); 2697 idr_remove(&link_idr, id); 2698 spin_unlock_bh(&link_idr_lock); 2699 } 2700 2701 /* Clean up bpf_link and corresponding anon_inode file and FD. After 2702 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 2703 * anon_inode's release() call. This helper marksbpf_link as 2704 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 2705 * is not decremented, it's the responsibility of a calling code that failed 2706 * to complete bpf_link initialization. 2707 */ 2708 void bpf_link_cleanup(struct bpf_link_primer *primer) 2709 { 2710 primer->link->prog = NULL; 2711 bpf_link_free_id(primer->id); 2712 fput(primer->file); 2713 put_unused_fd(primer->fd); 2714 } 2715 2716 void bpf_link_inc(struct bpf_link *link) 2717 { 2718 atomic64_inc(&link->refcnt); 2719 } 2720 2721 /* bpf_link_free is guaranteed to be called from process context */ 2722 static void bpf_link_free(struct bpf_link *link) 2723 { 2724 bpf_link_free_id(link->id); 2725 if (link->prog) { 2726 /* detach BPF program, clean up used resources */ 2727 link->ops->release(link); 2728 bpf_prog_put(link->prog); 2729 } 2730 /* free bpf_link and its containing memory */ 2731 link->ops->dealloc(link); 2732 } 2733 2734 static void bpf_link_put_deferred(struct work_struct *work) 2735 { 2736 struct bpf_link *link = container_of(work, struct bpf_link, work); 2737 2738 bpf_link_free(link); 2739 } 2740 2741 /* bpf_link_put can be called from atomic context, but ensures that resources 2742 * are freed from process context 2743 */ 2744 void bpf_link_put(struct bpf_link *link) 2745 { 2746 if (!atomic64_dec_and_test(&link->refcnt)) 2747 return; 2748 2749 if (in_atomic()) { 2750 INIT_WORK(&link->work, bpf_link_put_deferred); 2751 schedule_work(&link->work); 2752 } else { 2753 bpf_link_free(link); 2754 } 2755 } 2756 EXPORT_SYMBOL(bpf_link_put); 2757 2758 static int bpf_link_release(struct inode *inode, struct file *filp) 2759 { 2760 struct bpf_link *link = filp->private_data; 2761 2762 bpf_link_put(link); 2763 return 0; 2764 } 2765 2766 #ifdef CONFIG_PROC_FS 2767 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 2768 #define BPF_MAP_TYPE(_id, _ops) 2769 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 2770 static const char *bpf_link_type_strs[] = { 2771 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 2772 #include <linux/bpf_types.h> 2773 }; 2774 #undef BPF_PROG_TYPE 2775 #undef BPF_MAP_TYPE 2776 #undef BPF_LINK_TYPE 2777 2778 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 2779 { 2780 const struct bpf_link *link = filp->private_data; 2781 const struct bpf_prog *prog = link->prog; 2782 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2783 2784 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2785 seq_printf(m, 2786 "link_type:\t%s\n" 2787 "link_id:\t%u\n" 2788 "prog_tag:\t%s\n" 2789 "prog_id:\t%u\n", 2790 bpf_link_type_strs[link->type], 2791 link->id, 2792 prog_tag, 2793 prog->aux->id); 2794 if (link->ops->show_fdinfo) 2795 link->ops->show_fdinfo(link, m); 2796 } 2797 #endif 2798 2799 static const struct file_operations bpf_link_fops = { 2800 #ifdef CONFIG_PROC_FS 2801 .show_fdinfo = bpf_link_show_fdinfo, 2802 #endif 2803 .release = bpf_link_release, 2804 .read = bpf_dummy_read, 2805 .write = bpf_dummy_write, 2806 }; 2807 2808 static int bpf_link_alloc_id(struct bpf_link *link) 2809 { 2810 int id; 2811 2812 idr_preload(GFP_KERNEL); 2813 spin_lock_bh(&link_idr_lock); 2814 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 2815 spin_unlock_bh(&link_idr_lock); 2816 idr_preload_end(); 2817 2818 return id; 2819 } 2820 2821 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 2822 * reserving unused FD and allocating ID from link_idr. This is to be paired 2823 * with bpf_link_settle() to install FD and ID and expose bpf_link to 2824 * user-space, if bpf_link is successfully attached. If not, bpf_link and 2825 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 2826 * transient state is passed around in struct bpf_link_primer. 2827 * This is preferred way to create and initialize bpf_link, especially when 2828 * there are complicated and expensive operations in between creating bpf_link 2829 * itself and attaching it to BPF hook. By using bpf_link_prime() and 2830 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 2831 * expensive (and potentially failing) roll back operations in a rare case 2832 * that file, FD, or ID can't be allocated. 2833 */ 2834 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 2835 { 2836 struct file *file; 2837 int fd, id; 2838 2839 fd = get_unused_fd_flags(O_CLOEXEC); 2840 if (fd < 0) 2841 return fd; 2842 2843 2844 id = bpf_link_alloc_id(link); 2845 if (id < 0) { 2846 put_unused_fd(fd); 2847 return id; 2848 } 2849 2850 file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC); 2851 if (IS_ERR(file)) { 2852 bpf_link_free_id(id); 2853 put_unused_fd(fd); 2854 return PTR_ERR(file); 2855 } 2856 2857 primer->link = link; 2858 primer->file = file; 2859 primer->fd = fd; 2860 primer->id = id; 2861 return 0; 2862 } 2863 2864 int bpf_link_settle(struct bpf_link_primer *primer) 2865 { 2866 /* make bpf_link fetchable by ID */ 2867 spin_lock_bh(&link_idr_lock); 2868 primer->link->id = primer->id; 2869 spin_unlock_bh(&link_idr_lock); 2870 /* make bpf_link fetchable by FD */ 2871 fd_install(primer->fd, primer->file); 2872 /* pass through installed FD */ 2873 return primer->fd; 2874 } 2875 2876 int bpf_link_new_fd(struct bpf_link *link) 2877 { 2878 return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC); 2879 } 2880 2881 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 2882 { 2883 struct fd f = fdget(ufd); 2884 struct bpf_link *link; 2885 2886 if (!f.file) 2887 return ERR_PTR(-EBADF); 2888 if (f.file->f_op != &bpf_link_fops) { 2889 fdput(f); 2890 return ERR_PTR(-EINVAL); 2891 } 2892 2893 link = f.file->private_data; 2894 bpf_link_inc(link); 2895 fdput(f); 2896 2897 return link; 2898 } 2899 EXPORT_SYMBOL(bpf_link_get_from_fd); 2900 2901 static void bpf_tracing_link_release(struct bpf_link *link) 2902 { 2903 struct bpf_tracing_link *tr_link = 2904 container_of(link, struct bpf_tracing_link, link.link); 2905 2906 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 2907 tr_link->trampoline)); 2908 2909 bpf_trampoline_put(tr_link->trampoline); 2910 2911 /* tgt_prog is NULL if target is a kernel function */ 2912 if (tr_link->tgt_prog) 2913 bpf_prog_put(tr_link->tgt_prog); 2914 } 2915 2916 static void bpf_tracing_link_dealloc(struct bpf_link *link) 2917 { 2918 struct bpf_tracing_link *tr_link = 2919 container_of(link, struct bpf_tracing_link, link.link); 2920 2921 kfree(tr_link); 2922 } 2923 2924 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 2925 struct seq_file *seq) 2926 { 2927 struct bpf_tracing_link *tr_link = 2928 container_of(link, struct bpf_tracing_link, link.link); 2929 2930 seq_printf(seq, 2931 "attach_type:\t%d\n", 2932 tr_link->attach_type); 2933 } 2934 2935 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 2936 struct bpf_link_info *info) 2937 { 2938 struct bpf_tracing_link *tr_link = 2939 container_of(link, struct bpf_tracing_link, link.link); 2940 2941 info->tracing.attach_type = tr_link->attach_type; 2942 bpf_trampoline_unpack_key(tr_link->trampoline->key, 2943 &info->tracing.target_obj_id, 2944 &info->tracing.target_btf_id); 2945 2946 return 0; 2947 } 2948 2949 static const struct bpf_link_ops bpf_tracing_link_lops = { 2950 .release = bpf_tracing_link_release, 2951 .dealloc = bpf_tracing_link_dealloc, 2952 .show_fdinfo = bpf_tracing_link_show_fdinfo, 2953 .fill_link_info = bpf_tracing_link_fill_link_info, 2954 }; 2955 2956 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 2957 int tgt_prog_fd, 2958 u32 btf_id, 2959 u64 bpf_cookie) 2960 { 2961 struct bpf_link_primer link_primer; 2962 struct bpf_prog *tgt_prog = NULL; 2963 struct bpf_trampoline *tr = NULL; 2964 struct bpf_tracing_link *link; 2965 u64 key = 0; 2966 int err; 2967 2968 switch (prog->type) { 2969 case BPF_PROG_TYPE_TRACING: 2970 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 2971 prog->expected_attach_type != BPF_TRACE_FEXIT && 2972 prog->expected_attach_type != BPF_MODIFY_RETURN) { 2973 err = -EINVAL; 2974 goto out_put_prog; 2975 } 2976 break; 2977 case BPF_PROG_TYPE_EXT: 2978 if (prog->expected_attach_type != 0) { 2979 err = -EINVAL; 2980 goto out_put_prog; 2981 } 2982 break; 2983 case BPF_PROG_TYPE_LSM: 2984 if (prog->expected_attach_type != BPF_LSM_MAC) { 2985 err = -EINVAL; 2986 goto out_put_prog; 2987 } 2988 break; 2989 default: 2990 err = -EINVAL; 2991 goto out_put_prog; 2992 } 2993 2994 if (!!tgt_prog_fd != !!btf_id) { 2995 err = -EINVAL; 2996 goto out_put_prog; 2997 } 2998 2999 if (tgt_prog_fd) { 3000 /* For now we only allow new targets for BPF_PROG_TYPE_EXT */ 3001 if (prog->type != BPF_PROG_TYPE_EXT) { 3002 err = -EINVAL; 3003 goto out_put_prog; 3004 } 3005 3006 tgt_prog = bpf_prog_get(tgt_prog_fd); 3007 if (IS_ERR(tgt_prog)) { 3008 err = PTR_ERR(tgt_prog); 3009 tgt_prog = NULL; 3010 goto out_put_prog; 3011 } 3012 3013 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3014 } 3015 3016 link = kzalloc(sizeof(*link), GFP_USER); 3017 if (!link) { 3018 err = -ENOMEM; 3019 goto out_put_prog; 3020 } 3021 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3022 &bpf_tracing_link_lops, prog); 3023 link->attach_type = prog->expected_attach_type; 3024 link->link.cookie = bpf_cookie; 3025 3026 mutex_lock(&prog->aux->dst_mutex); 3027 3028 /* There are a few possible cases here: 3029 * 3030 * - if prog->aux->dst_trampoline is set, the program was just loaded 3031 * and not yet attached to anything, so we can use the values stored 3032 * in prog->aux 3033 * 3034 * - if prog->aux->dst_trampoline is NULL, the program has already been 3035 * attached to a target and its initial target was cleared (below) 3036 * 3037 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3038 * target_btf_id using the link_create API. 3039 * 3040 * - if tgt_prog == NULL when this function was called using the old 3041 * raw_tracepoint_open API, and we need a target from prog->aux 3042 * 3043 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3044 * was detached and is going for re-attachment. 3045 */ 3046 if (!prog->aux->dst_trampoline && !tgt_prog) { 3047 /* 3048 * Allow re-attach for TRACING and LSM programs. If it's 3049 * currently linked, bpf_trampoline_link_prog will fail. 3050 * EXT programs need to specify tgt_prog_fd, so they 3051 * re-attach in separate code path. 3052 */ 3053 if (prog->type != BPF_PROG_TYPE_TRACING && 3054 prog->type != BPF_PROG_TYPE_LSM) { 3055 err = -EINVAL; 3056 goto out_unlock; 3057 } 3058 btf_id = prog->aux->attach_btf_id; 3059 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3060 } 3061 3062 if (!prog->aux->dst_trampoline || 3063 (key && key != prog->aux->dst_trampoline->key)) { 3064 /* If there is no saved target, or the specified target is 3065 * different from the destination specified at load time, we 3066 * need a new trampoline and a check for compatibility 3067 */ 3068 struct bpf_attach_target_info tgt_info = {}; 3069 3070 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3071 &tgt_info); 3072 if (err) 3073 goto out_unlock; 3074 3075 tr = bpf_trampoline_get(key, &tgt_info); 3076 if (!tr) { 3077 err = -ENOMEM; 3078 goto out_unlock; 3079 } 3080 } else { 3081 /* The caller didn't specify a target, or the target was the 3082 * same as the destination supplied during program load. This 3083 * means we can reuse the trampoline and reference from program 3084 * load time, and there is no need to allocate a new one. This 3085 * can only happen once for any program, as the saved values in 3086 * prog->aux are cleared below. 3087 */ 3088 tr = prog->aux->dst_trampoline; 3089 tgt_prog = prog->aux->dst_prog; 3090 } 3091 3092 err = bpf_link_prime(&link->link.link, &link_primer); 3093 if (err) 3094 goto out_unlock; 3095 3096 err = bpf_trampoline_link_prog(&link->link, tr); 3097 if (err) { 3098 bpf_link_cleanup(&link_primer); 3099 link = NULL; 3100 goto out_unlock; 3101 } 3102 3103 link->tgt_prog = tgt_prog; 3104 link->trampoline = tr; 3105 3106 /* Always clear the trampoline and target prog from prog->aux to make 3107 * sure the original attach destination is not kept alive after a 3108 * program is (re-)attached to another target. 3109 */ 3110 if (prog->aux->dst_prog && 3111 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3112 /* got extra prog ref from syscall, or attaching to different prog */ 3113 bpf_prog_put(prog->aux->dst_prog); 3114 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3115 /* we allocated a new trampoline, so free the old one */ 3116 bpf_trampoline_put(prog->aux->dst_trampoline); 3117 3118 prog->aux->dst_prog = NULL; 3119 prog->aux->dst_trampoline = NULL; 3120 mutex_unlock(&prog->aux->dst_mutex); 3121 3122 return bpf_link_settle(&link_primer); 3123 out_unlock: 3124 if (tr && tr != prog->aux->dst_trampoline) 3125 bpf_trampoline_put(tr); 3126 mutex_unlock(&prog->aux->dst_mutex); 3127 kfree(link); 3128 out_put_prog: 3129 if (tgt_prog_fd && tgt_prog) 3130 bpf_prog_put(tgt_prog); 3131 return err; 3132 } 3133 3134 struct bpf_raw_tp_link { 3135 struct bpf_link link; 3136 struct bpf_raw_event_map *btp; 3137 }; 3138 3139 static void bpf_raw_tp_link_release(struct bpf_link *link) 3140 { 3141 struct bpf_raw_tp_link *raw_tp = 3142 container_of(link, struct bpf_raw_tp_link, link); 3143 3144 bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog); 3145 bpf_put_raw_tracepoint(raw_tp->btp); 3146 } 3147 3148 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3149 { 3150 struct bpf_raw_tp_link *raw_tp = 3151 container_of(link, struct bpf_raw_tp_link, link); 3152 3153 kfree(raw_tp); 3154 } 3155 3156 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3157 struct seq_file *seq) 3158 { 3159 struct bpf_raw_tp_link *raw_tp_link = 3160 container_of(link, struct bpf_raw_tp_link, link); 3161 3162 seq_printf(seq, 3163 "tp_name:\t%s\n", 3164 raw_tp_link->btp->tp->name); 3165 } 3166 3167 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3168 struct bpf_link_info *info) 3169 { 3170 struct bpf_raw_tp_link *raw_tp_link = 3171 container_of(link, struct bpf_raw_tp_link, link); 3172 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3173 const char *tp_name = raw_tp_link->btp->tp->name; 3174 u32 ulen = info->raw_tracepoint.tp_name_len; 3175 size_t tp_len = strlen(tp_name); 3176 3177 if (!ulen ^ !ubuf) 3178 return -EINVAL; 3179 3180 info->raw_tracepoint.tp_name_len = tp_len + 1; 3181 3182 if (!ubuf) 3183 return 0; 3184 3185 if (ulen >= tp_len + 1) { 3186 if (copy_to_user(ubuf, tp_name, tp_len + 1)) 3187 return -EFAULT; 3188 } else { 3189 char zero = '\0'; 3190 3191 if (copy_to_user(ubuf, tp_name, ulen - 1)) 3192 return -EFAULT; 3193 if (put_user(zero, ubuf + ulen - 1)) 3194 return -EFAULT; 3195 return -ENOSPC; 3196 } 3197 3198 return 0; 3199 } 3200 3201 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3202 .release = bpf_raw_tp_link_release, 3203 .dealloc = bpf_raw_tp_link_dealloc, 3204 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3205 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3206 }; 3207 3208 #ifdef CONFIG_PERF_EVENTS 3209 struct bpf_perf_link { 3210 struct bpf_link link; 3211 struct file *perf_file; 3212 }; 3213 3214 static void bpf_perf_link_release(struct bpf_link *link) 3215 { 3216 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3217 struct perf_event *event = perf_link->perf_file->private_data; 3218 3219 perf_event_free_bpf_prog(event); 3220 fput(perf_link->perf_file); 3221 } 3222 3223 static void bpf_perf_link_dealloc(struct bpf_link *link) 3224 { 3225 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3226 3227 kfree(perf_link); 3228 } 3229 3230 static const struct bpf_link_ops bpf_perf_link_lops = { 3231 .release = bpf_perf_link_release, 3232 .dealloc = bpf_perf_link_dealloc, 3233 }; 3234 3235 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3236 { 3237 struct bpf_link_primer link_primer; 3238 struct bpf_perf_link *link; 3239 struct perf_event *event; 3240 struct file *perf_file; 3241 int err; 3242 3243 if (attr->link_create.flags) 3244 return -EINVAL; 3245 3246 perf_file = perf_event_get(attr->link_create.target_fd); 3247 if (IS_ERR(perf_file)) 3248 return PTR_ERR(perf_file); 3249 3250 link = kzalloc(sizeof(*link), GFP_USER); 3251 if (!link) { 3252 err = -ENOMEM; 3253 goto out_put_file; 3254 } 3255 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog); 3256 link->perf_file = perf_file; 3257 3258 err = bpf_link_prime(&link->link, &link_primer); 3259 if (err) { 3260 kfree(link); 3261 goto out_put_file; 3262 } 3263 3264 event = perf_file->private_data; 3265 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 3266 if (err) { 3267 bpf_link_cleanup(&link_primer); 3268 goto out_put_file; 3269 } 3270 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 3271 bpf_prog_inc(prog); 3272 3273 return bpf_link_settle(&link_primer); 3274 3275 out_put_file: 3276 fput(perf_file); 3277 return err; 3278 } 3279 #else 3280 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3281 { 3282 return -EOPNOTSUPP; 3283 } 3284 #endif /* CONFIG_PERF_EVENTS */ 3285 3286 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 3287 const char __user *user_tp_name) 3288 { 3289 struct bpf_link_primer link_primer; 3290 struct bpf_raw_tp_link *link; 3291 struct bpf_raw_event_map *btp; 3292 const char *tp_name; 3293 char buf[128]; 3294 int err; 3295 3296 switch (prog->type) { 3297 case BPF_PROG_TYPE_TRACING: 3298 case BPF_PROG_TYPE_EXT: 3299 case BPF_PROG_TYPE_LSM: 3300 if (user_tp_name) 3301 /* The attach point for this category of programs 3302 * should be specified via btf_id during program load. 3303 */ 3304 return -EINVAL; 3305 if (prog->type == BPF_PROG_TYPE_TRACING && 3306 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 3307 tp_name = prog->aux->attach_func_name; 3308 break; 3309 } 3310 return bpf_tracing_prog_attach(prog, 0, 0, 0); 3311 case BPF_PROG_TYPE_RAW_TRACEPOINT: 3312 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 3313 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 3314 return -EFAULT; 3315 buf[sizeof(buf) - 1] = 0; 3316 tp_name = buf; 3317 break; 3318 default: 3319 return -EINVAL; 3320 } 3321 3322 btp = bpf_get_raw_tracepoint(tp_name); 3323 if (!btp) 3324 return -ENOENT; 3325 3326 link = kzalloc(sizeof(*link), GFP_USER); 3327 if (!link) { 3328 err = -ENOMEM; 3329 goto out_put_btp; 3330 } 3331 bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 3332 &bpf_raw_tp_link_lops, prog); 3333 link->btp = btp; 3334 3335 err = bpf_link_prime(&link->link, &link_primer); 3336 if (err) { 3337 kfree(link); 3338 goto out_put_btp; 3339 } 3340 3341 err = bpf_probe_register(link->btp, prog); 3342 if (err) { 3343 bpf_link_cleanup(&link_primer); 3344 goto out_put_btp; 3345 } 3346 3347 return bpf_link_settle(&link_primer); 3348 3349 out_put_btp: 3350 bpf_put_raw_tracepoint(btp); 3351 return err; 3352 } 3353 3354 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd 3355 3356 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 3357 { 3358 struct bpf_prog *prog; 3359 int fd; 3360 3361 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 3362 return -EINVAL; 3363 3364 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 3365 if (IS_ERR(prog)) 3366 return PTR_ERR(prog); 3367 3368 fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name)); 3369 if (fd < 0) 3370 bpf_prog_put(prog); 3371 return fd; 3372 } 3373 3374 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 3375 enum bpf_attach_type attach_type) 3376 { 3377 switch (prog->type) { 3378 case BPF_PROG_TYPE_CGROUP_SOCK: 3379 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3380 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3381 case BPF_PROG_TYPE_SK_LOOKUP: 3382 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 3383 case BPF_PROG_TYPE_CGROUP_SKB: 3384 if (!capable(CAP_NET_ADMIN)) 3385 /* cg-skb progs can be loaded by unpriv user. 3386 * check permissions at attach time. 3387 */ 3388 return -EPERM; 3389 return prog->enforce_expected_attach_type && 3390 prog->expected_attach_type != attach_type ? 3391 -EINVAL : 0; 3392 default: 3393 return 0; 3394 } 3395 } 3396 3397 static enum bpf_prog_type 3398 attach_type_to_prog_type(enum bpf_attach_type attach_type) 3399 { 3400 switch (attach_type) { 3401 case BPF_CGROUP_INET_INGRESS: 3402 case BPF_CGROUP_INET_EGRESS: 3403 return BPF_PROG_TYPE_CGROUP_SKB; 3404 case BPF_CGROUP_INET_SOCK_CREATE: 3405 case BPF_CGROUP_INET_SOCK_RELEASE: 3406 case BPF_CGROUP_INET4_POST_BIND: 3407 case BPF_CGROUP_INET6_POST_BIND: 3408 return BPF_PROG_TYPE_CGROUP_SOCK; 3409 case BPF_CGROUP_INET4_BIND: 3410 case BPF_CGROUP_INET6_BIND: 3411 case BPF_CGROUP_INET4_CONNECT: 3412 case BPF_CGROUP_INET6_CONNECT: 3413 case BPF_CGROUP_INET4_GETPEERNAME: 3414 case BPF_CGROUP_INET6_GETPEERNAME: 3415 case BPF_CGROUP_INET4_GETSOCKNAME: 3416 case BPF_CGROUP_INET6_GETSOCKNAME: 3417 case BPF_CGROUP_UDP4_SENDMSG: 3418 case BPF_CGROUP_UDP6_SENDMSG: 3419 case BPF_CGROUP_UDP4_RECVMSG: 3420 case BPF_CGROUP_UDP6_RECVMSG: 3421 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 3422 case BPF_CGROUP_SOCK_OPS: 3423 return BPF_PROG_TYPE_SOCK_OPS; 3424 case BPF_CGROUP_DEVICE: 3425 return BPF_PROG_TYPE_CGROUP_DEVICE; 3426 case BPF_SK_MSG_VERDICT: 3427 return BPF_PROG_TYPE_SK_MSG; 3428 case BPF_SK_SKB_STREAM_PARSER: 3429 case BPF_SK_SKB_STREAM_VERDICT: 3430 case BPF_SK_SKB_VERDICT: 3431 return BPF_PROG_TYPE_SK_SKB; 3432 case BPF_LIRC_MODE2: 3433 return BPF_PROG_TYPE_LIRC_MODE2; 3434 case BPF_FLOW_DISSECTOR: 3435 return BPF_PROG_TYPE_FLOW_DISSECTOR; 3436 case BPF_CGROUP_SYSCTL: 3437 return BPF_PROG_TYPE_CGROUP_SYSCTL; 3438 case BPF_CGROUP_GETSOCKOPT: 3439 case BPF_CGROUP_SETSOCKOPT: 3440 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 3441 case BPF_TRACE_ITER: 3442 case BPF_TRACE_RAW_TP: 3443 case BPF_TRACE_FENTRY: 3444 case BPF_TRACE_FEXIT: 3445 case BPF_MODIFY_RETURN: 3446 return BPF_PROG_TYPE_TRACING; 3447 case BPF_LSM_MAC: 3448 return BPF_PROG_TYPE_LSM; 3449 case BPF_SK_LOOKUP: 3450 return BPF_PROG_TYPE_SK_LOOKUP; 3451 case BPF_XDP: 3452 return BPF_PROG_TYPE_XDP; 3453 case BPF_LSM_CGROUP: 3454 return BPF_PROG_TYPE_LSM; 3455 default: 3456 return BPF_PROG_TYPE_UNSPEC; 3457 } 3458 } 3459 3460 #define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd 3461 3462 #define BPF_F_ATTACH_MASK \ 3463 (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE) 3464 3465 static int bpf_prog_attach(const union bpf_attr *attr) 3466 { 3467 enum bpf_prog_type ptype; 3468 struct bpf_prog *prog; 3469 int ret; 3470 3471 if (CHECK_ATTR(BPF_PROG_ATTACH)) 3472 return -EINVAL; 3473 3474 if (attr->attach_flags & ~BPF_F_ATTACH_MASK) 3475 return -EINVAL; 3476 3477 ptype = attach_type_to_prog_type(attr->attach_type); 3478 if (ptype == BPF_PROG_TYPE_UNSPEC) 3479 return -EINVAL; 3480 3481 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 3482 if (IS_ERR(prog)) 3483 return PTR_ERR(prog); 3484 3485 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 3486 bpf_prog_put(prog); 3487 return -EINVAL; 3488 } 3489 3490 switch (ptype) { 3491 case BPF_PROG_TYPE_SK_SKB: 3492 case BPF_PROG_TYPE_SK_MSG: 3493 ret = sock_map_get_from_fd(attr, prog); 3494 break; 3495 case BPF_PROG_TYPE_LIRC_MODE2: 3496 ret = lirc_prog_attach(attr, prog); 3497 break; 3498 case BPF_PROG_TYPE_FLOW_DISSECTOR: 3499 ret = netns_bpf_prog_attach(attr, prog); 3500 break; 3501 case BPF_PROG_TYPE_CGROUP_DEVICE: 3502 case BPF_PROG_TYPE_CGROUP_SKB: 3503 case BPF_PROG_TYPE_CGROUP_SOCK: 3504 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3505 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3506 case BPF_PROG_TYPE_CGROUP_SYSCTL: 3507 case BPF_PROG_TYPE_SOCK_OPS: 3508 case BPF_PROG_TYPE_LSM: 3509 if (ptype == BPF_PROG_TYPE_LSM && 3510 prog->expected_attach_type != BPF_LSM_CGROUP) 3511 ret = -EINVAL; 3512 else 3513 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 3514 break; 3515 default: 3516 ret = -EINVAL; 3517 } 3518 3519 if (ret) 3520 bpf_prog_put(prog); 3521 return ret; 3522 } 3523 3524 #define BPF_PROG_DETACH_LAST_FIELD attach_type 3525 3526 static int bpf_prog_detach(const union bpf_attr *attr) 3527 { 3528 enum bpf_prog_type ptype; 3529 3530 if (CHECK_ATTR(BPF_PROG_DETACH)) 3531 return -EINVAL; 3532 3533 ptype = attach_type_to_prog_type(attr->attach_type); 3534 3535 switch (ptype) { 3536 case BPF_PROG_TYPE_SK_MSG: 3537 case BPF_PROG_TYPE_SK_SKB: 3538 return sock_map_prog_detach(attr, ptype); 3539 case BPF_PROG_TYPE_LIRC_MODE2: 3540 return lirc_prog_detach(attr); 3541 case BPF_PROG_TYPE_FLOW_DISSECTOR: 3542 return netns_bpf_prog_detach(attr, ptype); 3543 case BPF_PROG_TYPE_CGROUP_DEVICE: 3544 case BPF_PROG_TYPE_CGROUP_SKB: 3545 case BPF_PROG_TYPE_CGROUP_SOCK: 3546 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3547 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3548 case BPF_PROG_TYPE_CGROUP_SYSCTL: 3549 case BPF_PROG_TYPE_SOCK_OPS: 3550 case BPF_PROG_TYPE_LSM: 3551 return cgroup_bpf_prog_detach(attr, ptype); 3552 default: 3553 return -EINVAL; 3554 } 3555 } 3556 3557 #define BPF_PROG_QUERY_LAST_FIELD query.prog_attach_flags 3558 3559 static int bpf_prog_query(const union bpf_attr *attr, 3560 union bpf_attr __user *uattr) 3561 { 3562 if (!capable(CAP_NET_ADMIN)) 3563 return -EPERM; 3564 if (CHECK_ATTR(BPF_PROG_QUERY)) 3565 return -EINVAL; 3566 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 3567 return -EINVAL; 3568 3569 switch (attr->query.attach_type) { 3570 case BPF_CGROUP_INET_INGRESS: 3571 case BPF_CGROUP_INET_EGRESS: 3572 case BPF_CGROUP_INET_SOCK_CREATE: 3573 case BPF_CGROUP_INET_SOCK_RELEASE: 3574 case BPF_CGROUP_INET4_BIND: 3575 case BPF_CGROUP_INET6_BIND: 3576 case BPF_CGROUP_INET4_POST_BIND: 3577 case BPF_CGROUP_INET6_POST_BIND: 3578 case BPF_CGROUP_INET4_CONNECT: 3579 case BPF_CGROUP_INET6_CONNECT: 3580 case BPF_CGROUP_INET4_GETPEERNAME: 3581 case BPF_CGROUP_INET6_GETPEERNAME: 3582 case BPF_CGROUP_INET4_GETSOCKNAME: 3583 case BPF_CGROUP_INET6_GETSOCKNAME: 3584 case BPF_CGROUP_UDP4_SENDMSG: 3585 case BPF_CGROUP_UDP6_SENDMSG: 3586 case BPF_CGROUP_UDP4_RECVMSG: 3587 case BPF_CGROUP_UDP6_RECVMSG: 3588 case BPF_CGROUP_SOCK_OPS: 3589 case BPF_CGROUP_DEVICE: 3590 case BPF_CGROUP_SYSCTL: 3591 case BPF_CGROUP_GETSOCKOPT: 3592 case BPF_CGROUP_SETSOCKOPT: 3593 case BPF_LSM_CGROUP: 3594 return cgroup_bpf_prog_query(attr, uattr); 3595 case BPF_LIRC_MODE2: 3596 return lirc_prog_query(attr, uattr); 3597 case BPF_FLOW_DISSECTOR: 3598 case BPF_SK_LOOKUP: 3599 return netns_bpf_prog_query(attr, uattr); 3600 case BPF_SK_SKB_STREAM_PARSER: 3601 case BPF_SK_SKB_STREAM_VERDICT: 3602 case BPF_SK_MSG_VERDICT: 3603 case BPF_SK_SKB_VERDICT: 3604 return sock_map_bpf_prog_query(attr, uattr); 3605 default: 3606 return -EINVAL; 3607 } 3608 } 3609 3610 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 3611 3612 static int bpf_prog_test_run(const union bpf_attr *attr, 3613 union bpf_attr __user *uattr) 3614 { 3615 struct bpf_prog *prog; 3616 int ret = -ENOTSUPP; 3617 3618 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 3619 return -EINVAL; 3620 3621 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 3622 (!attr->test.ctx_size_in && attr->test.ctx_in)) 3623 return -EINVAL; 3624 3625 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 3626 (!attr->test.ctx_size_out && attr->test.ctx_out)) 3627 return -EINVAL; 3628 3629 prog = bpf_prog_get(attr->test.prog_fd); 3630 if (IS_ERR(prog)) 3631 return PTR_ERR(prog); 3632 3633 if (prog->aux->ops->test_run) 3634 ret = prog->aux->ops->test_run(prog, attr, uattr); 3635 3636 bpf_prog_put(prog); 3637 return ret; 3638 } 3639 3640 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 3641 3642 static int bpf_obj_get_next_id(const union bpf_attr *attr, 3643 union bpf_attr __user *uattr, 3644 struct idr *idr, 3645 spinlock_t *lock) 3646 { 3647 u32 next_id = attr->start_id; 3648 int err = 0; 3649 3650 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 3651 return -EINVAL; 3652 3653 if (!capable(CAP_SYS_ADMIN)) 3654 return -EPERM; 3655 3656 next_id++; 3657 spin_lock_bh(lock); 3658 if (!idr_get_next(idr, &next_id)) 3659 err = -ENOENT; 3660 spin_unlock_bh(lock); 3661 3662 if (!err) 3663 err = put_user(next_id, &uattr->next_id); 3664 3665 return err; 3666 } 3667 3668 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 3669 { 3670 struct bpf_map *map; 3671 3672 spin_lock_bh(&map_idr_lock); 3673 again: 3674 map = idr_get_next(&map_idr, id); 3675 if (map) { 3676 map = __bpf_map_inc_not_zero(map, false); 3677 if (IS_ERR(map)) { 3678 (*id)++; 3679 goto again; 3680 } 3681 } 3682 spin_unlock_bh(&map_idr_lock); 3683 3684 return map; 3685 } 3686 3687 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 3688 { 3689 struct bpf_prog *prog; 3690 3691 spin_lock_bh(&prog_idr_lock); 3692 again: 3693 prog = idr_get_next(&prog_idr, id); 3694 if (prog) { 3695 prog = bpf_prog_inc_not_zero(prog); 3696 if (IS_ERR(prog)) { 3697 (*id)++; 3698 goto again; 3699 } 3700 } 3701 spin_unlock_bh(&prog_idr_lock); 3702 3703 return prog; 3704 } 3705 3706 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 3707 3708 struct bpf_prog *bpf_prog_by_id(u32 id) 3709 { 3710 struct bpf_prog *prog; 3711 3712 if (!id) 3713 return ERR_PTR(-ENOENT); 3714 3715 spin_lock_bh(&prog_idr_lock); 3716 prog = idr_find(&prog_idr, id); 3717 if (prog) 3718 prog = bpf_prog_inc_not_zero(prog); 3719 else 3720 prog = ERR_PTR(-ENOENT); 3721 spin_unlock_bh(&prog_idr_lock); 3722 return prog; 3723 } 3724 3725 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 3726 { 3727 struct bpf_prog *prog; 3728 u32 id = attr->prog_id; 3729 int fd; 3730 3731 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 3732 return -EINVAL; 3733 3734 if (!capable(CAP_SYS_ADMIN)) 3735 return -EPERM; 3736 3737 prog = bpf_prog_by_id(id); 3738 if (IS_ERR(prog)) 3739 return PTR_ERR(prog); 3740 3741 fd = bpf_prog_new_fd(prog); 3742 if (fd < 0) 3743 bpf_prog_put(prog); 3744 3745 return fd; 3746 } 3747 3748 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 3749 3750 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 3751 { 3752 struct bpf_map *map; 3753 u32 id = attr->map_id; 3754 int f_flags; 3755 int fd; 3756 3757 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 3758 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 3759 return -EINVAL; 3760 3761 if (!capable(CAP_SYS_ADMIN)) 3762 return -EPERM; 3763 3764 f_flags = bpf_get_file_flag(attr->open_flags); 3765 if (f_flags < 0) 3766 return f_flags; 3767 3768 spin_lock_bh(&map_idr_lock); 3769 map = idr_find(&map_idr, id); 3770 if (map) 3771 map = __bpf_map_inc_not_zero(map, true); 3772 else 3773 map = ERR_PTR(-ENOENT); 3774 spin_unlock_bh(&map_idr_lock); 3775 3776 if (IS_ERR(map)) 3777 return PTR_ERR(map); 3778 3779 fd = bpf_map_new_fd(map, f_flags); 3780 if (fd < 0) 3781 bpf_map_put_with_uref(map); 3782 3783 return fd; 3784 } 3785 3786 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 3787 unsigned long addr, u32 *off, 3788 u32 *type) 3789 { 3790 const struct bpf_map *map; 3791 int i; 3792 3793 mutex_lock(&prog->aux->used_maps_mutex); 3794 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 3795 map = prog->aux->used_maps[i]; 3796 if (map == (void *)addr) { 3797 *type = BPF_PSEUDO_MAP_FD; 3798 goto out; 3799 } 3800 if (!map->ops->map_direct_value_meta) 3801 continue; 3802 if (!map->ops->map_direct_value_meta(map, addr, off)) { 3803 *type = BPF_PSEUDO_MAP_VALUE; 3804 goto out; 3805 } 3806 } 3807 map = NULL; 3808 3809 out: 3810 mutex_unlock(&prog->aux->used_maps_mutex); 3811 return map; 3812 } 3813 3814 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 3815 const struct cred *f_cred) 3816 { 3817 const struct bpf_map *map; 3818 struct bpf_insn *insns; 3819 u32 off, type; 3820 u64 imm; 3821 u8 code; 3822 int i; 3823 3824 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 3825 GFP_USER); 3826 if (!insns) 3827 return insns; 3828 3829 for (i = 0; i < prog->len; i++) { 3830 code = insns[i].code; 3831 3832 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 3833 insns[i].code = BPF_JMP | BPF_CALL; 3834 insns[i].imm = BPF_FUNC_tail_call; 3835 /* fall-through */ 3836 } 3837 if (code == (BPF_JMP | BPF_CALL) || 3838 code == (BPF_JMP | BPF_CALL_ARGS)) { 3839 if (code == (BPF_JMP | BPF_CALL_ARGS)) 3840 insns[i].code = BPF_JMP | BPF_CALL; 3841 if (!bpf_dump_raw_ok(f_cred)) 3842 insns[i].imm = 0; 3843 continue; 3844 } 3845 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 3846 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 3847 continue; 3848 } 3849 3850 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 3851 continue; 3852 3853 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 3854 map = bpf_map_from_imm(prog, imm, &off, &type); 3855 if (map) { 3856 insns[i].src_reg = type; 3857 insns[i].imm = map->id; 3858 insns[i + 1].imm = off; 3859 continue; 3860 } 3861 } 3862 3863 return insns; 3864 } 3865 3866 static int set_info_rec_size(struct bpf_prog_info *info) 3867 { 3868 /* 3869 * Ensure info.*_rec_size is the same as kernel expected size 3870 * 3871 * or 3872 * 3873 * Only allow zero *_rec_size if both _rec_size and _cnt are 3874 * zero. In this case, the kernel will set the expected 3875 * _rec_size back to the info. 3876 */ 3877 3878 if ((info->nr_func_info || info->func_info_rec_size) && 3879 info->func_info_rec_size != sizeof(struct bpf_func_info)) 3880 return -EINVAL; 3881 3882 if ((info->nr_line_info || info->line_info_rec_size) && 3883 info->line_info_rec_size != sizeof(struct bpf_line_info)) 3884 return -EINVAL; 3885 3886 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 3887 info->jited_line_info_rec_size != sizeof(__u64)) 3888 return -EINVAL; 3889 3890 info->func_info_rec_size = sizeof(struct bpf_func_info); 3891 info->line_info_rec_size = sizeof(struct bpf_line_info); 3892 info->jited_line_info_rec_size = sizeof(__u64); 3893 3894 return 0; 3895 } 3896 3897 static int bpf_prog_get_info_by_fd(struct file *file, 3898 struct bpf_prog *prog, 3899 const union bpf_attr *attr, 3900 union bpf_attr __user *uattr) 3901 { 3902 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 3903 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 3904 struct bpf_prog_info info; 3905 u32 info_len = attr->info.info_len; 3906 struct bpf_prog_kstats stats; 3907 char __user *uinsns; 3908 u32 ulen; 3909 int err; 3910 3911 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 3912 if (err) 3913 return err; 3914 info_len = min_t(u32, sizeof(info), info_len); 3915 3916 memset(&info, 0, sizeof(info)); 3917 if (copy_from_user(&info, uinfo, info_len)) 3918 return -EFAULT; 3919 3920 info.type = prog->type; 3921 info.id = prog->aux->id; 3922 info.load_time = prog->aux->load_time; 3923 info.created_by_uid = from_kuid_munged(current_user_ns(), 3924 prog->aux->user->uid); 3925 info.gpl_compatible = prog->gpl_compatible; 3926 3927 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 3928 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 3929 3930 mutex_lock(&prog->aux->used_maps_mutex); 3931 ulen = info.nr_map_ids; 3932 info.nr_map_ids = prog->aux->used_map_cnt; 3933 ulen = min_t(u32, info.nr_map_ids, ulen); 3934 if (ulen) { 3935 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 3936 u32 i; 3937 3938 for (i = 0; i < ulen; i++) 3939 if (put_user(prog->aux->used_maps[i]->id, 3940 &user_map_ids[i])) { 3941 mutex_unlock(&prog->aux->used_maps_mutex); 3942 return -EFAULT; 3943 } 3944 } 3945 mutex_unlock(&prog->aux->used_maps_mutex); 3946 3947 err = set_info_rec_size(&info); 3948 if (err) 3949 return err; 3950 3951 bpf_prog_get_stats(prog, &stats); 3952 info.run_time_ns = stats.nsecs; 3953 info.run_cnt = stats.cnt; 3954 info.recursion_misses = stats.misses; 3955 3956 info.verified_insns = prog->aux->verified_insns; 3957 3958 if (!bpf_capable()) { 3959 info.jited_prog_len = 0; 3960 info.xlated_prog_len = 0; 3961 info.nr_jited_ksyms = 0; 3962 info.nr_jited_func_lens = 0; 3963 info.nr_func_info = 0; 3964 info.nr_line_info = 0; 3965 info.nr_jited_line_info = 0; 3966 goto done; 3967 } 3968 3969 ulen = info.xlated_prog_len; 3970 info.xlated_prog_len = bpf_prog_insn_size(prog); 3971 if (info.xlated_prog_len && ulen) { 3972 struct bpf_insn *insns_sanitized; 3973 bool fault; 3974 3975 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) { 3976 info.xlated_prog_insns = 0; 3977 goto done; 3978 } 3979 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 3980 if (!insns_sanitized) 3981 return -ENOMEM; 3982 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 3983 ulen = min_t(u32, info.xlated_prog_len, ulen); 3984 fault = copy_to_user(uinsns, insns_sanitized, ulen); 3985 kfree(insns_sanitized); 3986 if (fault) 3987 return -EFAULT; 3988 } 3989 3990 if (bpf_prog_is_dev_bound(prog->aux)) { 3991 err = bpf_prog_offload_info_fill(&info, prog); 3992 if (err) 3993 return err; 3994 goto done; 3995 } 3996 3997 /* NOTE: the following code is supposed to be skipped for offload. 3998 * bpf_prog_offload_info_fill() is the place to fill similar fields 3999 * for offload. 4000 */ 4001 ulen = info.jited_prog_len; 4002 if (prog->aux->func_cnt) { 4003 u32 i; 4004 4005 info.jited_prog_len = 0; 4006 for (i = 0; i < prog->aux->func_cnt; i++) 4007 info.jited_prog_len += prog->aux->func[i]->jited_len; 4008 } else { 4009 info.jited_prog_len = prog->jited_len; 4010 } 4011 4012 if (info.jited_prog_len && ulen) { 4013 if (bpf_dump_raw_ok(file->f_cred)) { 4014 uinsns = u64_to_user_ptr(info.jited_prog_insns); 4015 ulen = min_t(u32, info.jited_prog_len, ulen); 4016 4017 /* for multi-function programs, copy the JITed 4018 * instructions for all the functions 4019 */ 4020 if (prog->aux->func_cnt) { 4021 u32 len, free, i; 4022 u8 *img; 4023 4024 free = ulen; 4025 for (i = 0; i < prog->aux->func_cnt; i++) { 4026 len = prog->aux->func[i]->jited_len; 4027 len = min_t(u32, len, free); 4028 img = (u8 *) prog->aux->func[i]->bpf_func; 4029 if (copy_to_user(uinsns, img, len)) 4030 return -EFAULT; 4031 uinsns += len; 4032 free -= len; 4033 if (!free) 4034 break; 4035 } 4036 } else { 4037 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 4038 return -EFAULT; 4039 } 4040 } else { 4041 info.jited_prog_insns = 0; 4042 } 4043 } 4044 4045 ulen = info.nr_jited_ksyms; 4046 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 4047 if (ulen) { 4048 if (bpf_dump_raw_ok(file->f_cred)) { 4049 unsigned long ksym_addr; 4050 u64 __user *user_ksyms; 4051 u32 i; 4052 4053 /* copy the address of the kernel symbol 4054 * corresponding to each function 4055 */ 4056 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 4057 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 4058 if (prog->aux->func_cnt) { 4059 for (i = 0; i < ulen; i++) { 4060 ksym_addr = (unsigned long) 4061 prog->aux->func[i]->bpf_func; 4062 if (put_user((u64) ksym_addr, 4063 &user_ksyms[i])) 4064 return -EFAULT; 4065 } 4066 } else { 4067 ksym_addr = (unsigned long) prog->bpf_func; 4068 if (put_user((u64) ksym_addr, &user_ksyms[0])) 4069 return -EFAULT; 4070 } 4071 } else { 4072 info.jited_ksyms = 0; 4073 } 4074 } 4075 4076 ulen = info.nr_jited_func_lens; 4077 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 4078 if (ulen) { 4079 if (bpf_dump_raw_ok(file->f_cred)) { 4080 u32 __user *user_lens; 4081 u32 func_len, i; 4082 4083 /* copy the JITed image lengths for each function */ 4084 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 4085 user_lens = u64_to_user_ptr(info.jited_func_lens); 4086 if (prog->aux->func_cnt) { 4087 for (i = 0; i < ulen; i++) { 4088 func_len = 4089 prog->aux->func[i]->jited_len; 4090 if (put_user(func_len, &user_lens[i])) 4091 return -EFAULT; 4092 } 4093 } else { 4094 func_len = prog->jited_len; 4095 if (put_user(func_len, &user_lens[0])) 4096 return -EFAULT; 4097 } 4098 } else { 4099 info.jited_func_lens = 0; 4100 } 4101 } 4102 4103 if (prog->aux->btf) 4104 info.btf_id = btf_obj_id(prog->aux->btf); 4105 info.attach_btf_id = prog->aux->attach_btf_id; 4106 if (attach_btf) 4107 info.attach_btf_obj_id = btf_obj_id(attach_btf); 4108 4109 ulen = info.nr_func_info; 4110 info.nr_func_info = prog->aux->func_info_cnt; 4111 if (info.nr_func_info && ulen) { 4112 char __user *user_finfo; 4113 4114 user_finfo = u64_to_user_ptr(info.func_info); 4115 ulen = min_t(u32, info.nr_func_info, ulen); 4116 if (copy_to_user(user_finfo, prog->aux->func_info, 4117 info.func_info_rec_size * ulen)) 4118 return -EFAULT; 4119 } 4120 4121 ulen = info.nr_line_info; 4122 info.nr_line_info = prog->aux->nr_linfo; 4123 if (info.nr_line_info && ulen) { 4124 __u8 __user *user_linfo; 4125 4126 user_linfo = u64_to_user_ptr(info.line_info); 4127 ulen = min_t(u32, info.nr_line_info, ulen); 4128 if (copy_to_user(user_linfo, prog->aux->linfo, 4129 info.line_info_rec_size * ulen)) 4130 return -EFAULT; 4131 } 4132 4133 ulen = info.nr_jited_line_info; 4134 if (prog->aux->jited_linfo) 4135 info.nr_jited_line_info = prog->aux->nr_linfo; 4136 else 4137 info.nr_jited_line_info = 0; 4138 if (info.nr_jited_line_info && ulen) { 4139 if (bpf_dump_raw_ok(file->f_cred)) { 4140 unsigned long line_addr; 4141 __u64 __user *user_linfo; 4142 u32 i; 4143 4144 user_linfo = u64_to_user_ptr(info.jited_line_info); 4145 ulen = min_t(u32, info.nr_jited_line_info, ulen); 4146 for (i = 0; i < ulen; i++) { 4147 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 4148 if (put_user((__u64)line_addr, &user_linfo[i])) 4149 return -EFAULT; 4150 } 4151 } else { 4152 info.jited_line_info = 0; 4153 } 4154 } 4155 4156 ulen = info.nr_prog_tags; 4157 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 4158 if (ulen) { 4159 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 4160 u32 i; 4161 4162 user_prog_tags = u64_to_user_ptr(info.prog_tags); 4163 ulen = min_t(u32, info.nr_prog_tags, ulen); 4164 if (prog->aux->func_cnt) { 4165 for (i = 0; i < ulen; i++) { 4166 if (copy_to_user(user_prog_tags[i], 4167 prog->aux->func[i]->tag, 4168 BPF_TAG_SIZE)) 4169 return -EFAULT; 4170 } 4171 } else { 4172 if (copy_to_user(user_prog_tags[0], 4173 prog->tag, BPF_TAG_SIZE)) 4174 return -EFAULT; 4175 } 4176 } 4177 4178 done: 4179 if (copy_to_user(uinfo, &info, info_len) || 4180 put_user(info_len, &uattr->info.info_len)) 4181 return -EFAULT; 4182 4183 return 0; 4184 } 4185 4186 static int bpf_map_get_info_by_fd(struct file *file, 4187 struct bpf_map *map, 4188 const union bpf_attr *attr, 4189 union bpf_attr __user *uattr) 4190 { 4191 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4192 struct bpf_map_info info; 4193 u32 info_len = attr->info.info_len; 4194 int err; 4195 4196 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4197 if (err) 4198 return err; 4199 info_len = min_t(u32, sizeof(info), info_len); 4200 4201 memset(&info, 0, sizeof(info)); 4202 info.type = map->map_type; 4203 info.id = map->id; 4204 info.key_size = map->key_size; 4205 info.value_size = map->value_size; 4206 info.max_entries = map->max_entries; 4207 info.map_flags = map->map_flags; 4208 info.map_extra = map->map_extra; 4209 memcpy(info.name, map->name, sizeof(map->name)); 4210 4211 if (map->btf) { 4212 info.btf_id = btf_obj_id(map->btf); 4213 info.btf_key_type_id = map->btf_key_type_id; 4214 info.btf_value_type_id = map->btf_value_type_id; 4215 } 4216 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 4217 4218 if (bpf_map_is_dev_bound(map)) { 4219 err = bpf_map_offload_info_fill(&info, map); 4220 if (err) 4221 return err; 4222 } 4223 4224 if (copy_to_user(uinfo, &info, info_len) || 4225 put_user(info_len, &uattr->info.info_len)) 4226 return -EFAULT; 4227 4228 return 0; 4229 } 4230 4231 static int bpf_btf_get_info_by_fd(struct file *file, 4232 struct btf *btf, 4233 const union bpf_attr *attr, 4234 union bpf_attr __user *uattr) 4235 { 4236 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4237 u32 info_len = attr->info.info_len; 4238 int err; 4239 4240 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 4241 if (err) 4242 return err; 4243 4244 return btf_get_info_by_fd(btf, attr, uattr); 4245 } 4246 4247 static int bpf_link_get_info_by_fd(struct file *file, 4248 struct bpf_link *link, 4249 const union bpf_attr *attr, 4250 union bpf_attr __user *uattr) 4251 { 4252 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4253 struct bpf_link_info info; 4254 u32 info_len = attr->info.info_len; 4255 int err; 4256 4257 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4258 if (err) 4259 return err; 4260 info_len = min_t(u32, sizeof(info), info_len); 4261 4262 memset(&info, 0, sizeof(info)); 4263 if (copy_from_user(&info, uinfo, info_len)) 4264 return -EFAULT; 4265 4266 info.type = link->type; 4267 info.id = link->id; 4268 info.prog_id = link->prog->aux->id; 4269 4270 if (link->ops->fill_link_info) { 4271 err = link->ops->fill_link_info(link, &info); 4272 if (err) 4273 return err; 4274 } 4275 4276 if (copy_to_user(uinfo, &info, info_len) || 4277 put_user(info_len, &uattr->info.info_len)) 4278 return -EFAULT; 4279 4280 return 0; 4281 } 4282 4283 4284 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 4285 4286 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 4287 union bpf_attr __user *uattr) 4288 { 4289 int ufd = attr->info.bpf_fd; 4290 struct fd f; 4291 int err; 4292 4293 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 4294 return -EINVAL; 4295 4296 f = fdget(ufd); 4297 if (!f.file) 4298 return -EBADFD; 4299 4300 if (f.file->f_op == &bpf_prog_fops) 4301 err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr, 4302 uattr); 4303 else if (f.file->f_op == &bpf_map_fops) 4304 err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr, 4305 uattr); 4306 else if (f.file->f_op == &btf_fops) 4307 err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr); 4308 else if (f.file->f_op == &bpf_link_fops) 4309 err = bpf_link_get_info_by_fd(f.file, f.file->private_data, 4310 attr, uattr); 4311 else 4312 err = -EINVAL; 4313 4314 fdput(f); 4315 return err; 4316 } 4317 4318 #define BPF_BTF_LOAD_LAST_FIELD btf_log_level 4319 4320 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr) 4321 { 4322 if (CHECK_ATTR(BPF_BTF_LOAD)) 4323 return -EINVAL; 4324 4325 if (!bpf_capable()) 4326 return -EPERM; 4327 4328 return btf_new_fd(attr, uattr); 4329 } 4330 4331 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id 4332 4333 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 4334 { 4335 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 4336 return -EINVAL; 4337 4338 if (!capable(CAP_SYS_ADMIN)) 4339 return -EPERM; 4340 4341 return btf_get_fd_by_id(attr->btf_id); 4342 } 4343 4344 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 4345 union bpf_attr __user *uattr, 4346 u32 prog_id, u32 fd_type, 4347 const char *buf, u64 probe_offset, 4348 u64 probe_addr) 4349 { 4350 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 4351 u32 len = buf ? strlen(buf) : 0, input_len; 4352 int err = 0; 4353 4354 if (put_user(len, &uattr->task_fd_query.buf_len)) 4355 return -EFAULT; 4356 input_len = attr->task_fd_query.buf_len; 4357 if (input_len && ubuf) { 4358 if (!len) { 4359 /* nothing to copy, just make ubuf NULL terminated */ 4360 char zero = '\0'; 4361 4362 if (put_user(zero, ubuf)) 4363 return -EFAULT; 4364 } else if (input_len >= len + 1) { 4365 /* ubuf can hold the string with NULL terminator */ 4366 if (copy_to_user(ubuf, buf, len + 1)) 4367 return -EFAULT; 4368 } else { 4369 /* ubuf cannot hold the string with NULL terminator, 4370 * do a partial copy with NULL terminator. 4371 */ 4372 char zero = '\0'; 4373 4374 err = -ENOSPC; 4375 if (copy_to_user(ubuf, buf, input_len - 1)) 4376 return -EFAULT; 4377 if (put_user(zero, ubuf + input_len - 1)) 4378 return -EFAULT; 4379 } 4380 } 4381 4382 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 4383 put_user(fd_type, &uattr->task_fd_query.fd_type) || 4384 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 4385 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 4386 return -EFAULT; 4387 4388 return err; 4389 } 4390 4391 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 4392 4393 static int bpf_task_fd_query(const union bpf_attr *attr, 4394 union bpf_attr __user *uattr) 4395 { 4396 pid_t pid = attr->task_fd_query.pid; 4397 u32 fd = attr->task_fd_query.fd; 4398 const struct perf_event *event; 4399 struct task_struct *task; 4400 struct file *file; 4401 int err; 4402 4403 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 4404 return -EINVAL; 4405 4406 if (!capable(CAP_SYS_ADMIN)) 4407 return -EPERM; 4408 4409 if (attr->task_fd_query.flags != 0) 4410 return -EINVAL; 4411 4412 rcu_read_lock(); 4413 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 4414 rcu_read_unlock(); 4415 if (!task) 4416 return -ENOENT; 4417 4418 err = 0; 4419 file = fget_task(task, fd); 4420 put_task_struct(task); 4421 if (!file) 4422 return -EBADF; 4423 4424 if (file->f_op == &bpf_link_fops) { 4425 struct bpf_link *link = file->private_data; 4426 4427 if (link->ops == &bpf_raw_tp_link_lops) { 4428 struct bpf_raw_tp_link *raw_tp = 4429 container_of(link, struct bpf_raw_tp_link, link); 4430 struct bpf_raw_event_map *btp = raw_tp->btp; 4431 4432 err = bpf_task_fd_query_copy(attr, uattr, 4433 raw_tp->link.prog->aux->id, 4434 BPF_FD_TYPE_RAW_TRACEPOINT, 4435 btp->tp->name, 0, 0); 4436 goto put_file; 4437 } 4438 goto out_not_supp; 4439 } 4440 4441 event = perf_get_event(file); 4442 if (!IS_ERR(event)) { 4443 u64 probe_offset, probe_addr; 4444 u32 prog_id, fd_type; 4445 const char *buf; 4446 4447 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 4448 &buf, &probe_offset, 4449 &probe_addr); 4450 if (!err) 4451 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 4452 fd_type, buf, 4453 probe_offset, 4454 probe_addr); 4455 goto put_file; 4456 } 4457 4458 out_not_supp: 4459 err = -ENOTSUPP; 4460 put_file: 4461 fput(file); 4462 return err; 4463 } 4464 4465 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 4466 4467 #define BPF_DO_BATCH(fn, ...) \ 4468 do { \ 4469 if (!fn) { \ 4470 err = -ENOTSUPP; \ 4471 goto err_put; \ 4472 } \ 4473 err = fn(__VA_ARGS__); \ 4474 } while (0) 4475 4476 static int bpf_map_do_batch(const union bpf_attr *attr, 4477 union bpf_attr __user *uattr, 4478 int cmd) 4479 { 4480 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 4481 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 4482 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 4483 struct bpf_map *map; 4484 int err, ufd; 4485 struct fd f; 4486 4487 if (CHECK_ATTR(BPF_MAP_BATCH)) 4488 return -EINVAL; 4489 4490 ufd = attr->batch.map_fd; 4491 f = fdget(ufd); 4492 map = __bpf_map_get(f); 4493 if (IS_ERR(map)) 4494 return PTR_ERR(map); 4495 if (has_write) 4496 bpf_map_write_active_inc(map); 4497 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 4498 err = -EPERM; 4499 goto err_put; 4500 } 4501 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 4502 err = -EPERM; 4503 goto err_put; 4504 } 4505 4506 if (cmd == BPF_MAP_LOOKUP_BATCH) 4507 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 4508 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 4509 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 4510 else if (cmd == BPF_MAP_UPDATE_BATCH) 4511 BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr); 4512 else 4513 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 4514 err_put: 4515 if (has_write) 4516 bpf_map_write_active_dec(map); 4517 fdput(f); 4518 return err; 4519 } 4520 4521 #define BPF_LINK_CREATE_LAST_FIELD link_create.kprobe_multi.cookies 4522 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 4523 { 4524 enum bpf_prog_type ptype; 4525 struct bpf_prog *prog; 4526 int ret; 4527 4528 if (CHECK_ATTR(BPF_LINK_CREATE)) 4529 return -EINVAL; 4530 4531 prog = bpf_prog_get(attr->link_create.prog_fd); 4532 if (IS_ERR(prog)) 4533 return PTR_ERR(prog); 4534 4535 ret = bpf_prog_attach_check_attach_type(prog, 4536 attr->link_create.attach_type); 4537 if (ret) 4538 goto out; 4539 4540 switch (prog->type) { 4541 case BPF_PROG_TYPE_EXT: 4542 break; 4543 case BPF_PROG_TYPE_PERF_EVENT: 4544 case BPF_PROG_TYPE_TRACEPOINT: 4545 if (attr->link_create.attach_type != BPF_PERF_EVENT) { 4546 ret = -EINVAL; 4547 goto out; 4548 } 4549 break; 4550 case BPF_PROG_TYPE_KPROBE: 4551 if (attr->link_create.attach_type != BPF_PERF_EVENT && 4552 attr->link_create.attach_type != BPF_TRACE_KPROBE_MULTI) { 4553 ret = -EINVAL; 4554 goto out; 4555 } 4556 break; 4557 default: 4558 ptype = attach_type_to_prog_type(attr->link_create.attach_type); 4559 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) { 4560 ret = -EINVAL; 4561 goto out; 4562 } 4563 break; 4564 } 4565 4566 switch (prog->type) { 4567 case BPF_PROG_TYPE_CGROUP_SKB: 4568 case BPF_PROG_TYPE_CGROUP_SOCK: 4569 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4570 case BPF_PROG_TYPE_SOCK_OPS: 4571 case BPF_PROG_TYPE_CGROUP_DEVICE: 4572 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4573 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4574 ret = cgroup_bpf_link_attach(attr, prog); 4575 break; 4576 case BPF_PROG_TYPE_EXT: 4577 ret = bpf_tracing_prog_attach(prog, 4578 attr->link_create.target_fd, 4579 attr->link_create.target_btf_id, 4580 attr->link_create.tracing.cookie); 4581 break; 4582 case BPF_PROG_TYPE_LSM: 4583 case BPF_PROG_TYPE_TRACING: 4584 if (attr->link_create.attach_type != prog->expected_attach_type) { 4585 ret = -EINVAL; 4586 goto out; 4587 } 4588 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 4589 ret = bpf_raw_tp_link_attach(prog, NULL); 4590 else if (prog->expected_attach_type == BPF_TRACE_ITER) 4591 ret = bpf_iter_link_attach(attr, uattr, prog); 4592 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 4593 ret = cgroup_bpf_link_attach(attr, prog); 4594 else 4595 ret = bpf_tracing_prog_attach(prog, 4596 attr->link_create.target_fd, 4597 attr->link_create.target_btf_id, 4598 attr->link_create.tracing.cookie); 4599 break; 4600 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4601 case BPF_PROG_TYPE_SK_LOOKUP: 4602 ret = netns_bpf_link_create(attr, prog); 4603 break; 4604 #ifdef CONFIG_NET 4605 case BPF_PROG_TYPE_XDP: 4606 ret = bpf_xdp_link_attach(attr, prog); 4607 break; 4608 #endif 4609 case BPF_PROG_TYPE_PERF_EVENT: 4610 case BPF_PROG_TYPE_TRACEPOINT: 4611 ret = bpf_perf_link_attach(attr, prog); 4612 break; 4613 case BPF_PROG_TYPE_KPROBE: 4614 if (attr->link_create.attach_type == BPF_PERF_EVENT) 4615 ret = bpf_perf_link_attach(attr, prog); 4616 else 4617 ret = bpf_kprobe_multi_link_attach(attr, prog); 4618 break; 4619 default: 4620 ret = -EINVAL; 4621 } 4622 4623 out: 4624 if (ret < 0) 4625 bpf_prog_put(prog); 4626 return ret; 4627 } 4628 4629 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 4630 4631 static int link_update(union bpf_attr *attr) 4632 { 4633 struct bpf_prog *old_prog = NULL, *new_prog; 4634 struct bpf_link *link; 4635 u32 flags; 4636 int ret; 4637 4638 if (CHECK_ATTR(BPF_LINK_UPDATE)) 4639 return -EINVAL; 4640 4641 flags = attr->link_update.flags; 4642 if (flags & ~BPF_F_REPLACE) 4643 return -EINVAL; 4644 4645 link = bpf_link_get_from_fd(attr->link_update.link_fd); 4646 if (IS_ERR(link)) 4647 return PTR_ERR(link); 4648 4649 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 4650 if (IS_ERR(new_prog)) { 4651 ret = PTR_ERR(new_prog); 4652 goto out_put_link; 4653 } 4654 4655 if (flags & BPF_F_REPLACE) { 4656 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 4657 if (IS_ERR(old_prog)) { 4658 ret = PTR_ERR(old_prog); 4659 old_prog = NULL; 4660 goto out_put_progs; 4661 } 4662 } else if (attr->link_update.old_prog_fd) { 4663 ret = -EINVAL; 4664 goto out_put_progs; 4665 } 4666 4667 if (link->ops->update_prog) 4668 ret = link->ops->update_prog(link, new_prog, old_prog); 4669 else 4670 ret = -EINVAL; 4671 4672 out_put_progs: 4673 if (old_prog) 4674 bpf_prog_put(old_prog); 4675 if (ret) 4676 bpf_prog_put(new_prog); 4677 out_put_link: 4678 bpf_link_put(link); 4679 return ret; 4680 } 4681 4682 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 4683 4684 static int link_detach(union bpf_attr *attr) 4685 { 4686 struct bpf_link *link; 4687 int ret; 4688 4689 if (CHECK_ATTR(BPF_LINK_DETACH)) 4690 return -EINVAL; 4691 4692 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 4693 if (IS_ERR(link)) 4694 return PTR_ERR(link); 4695 4696 if (link->ops->detach) 4697 ret = link->ops->detach(link); 4698 else 4699 ret = -EOPNOTSUPP; 4700 4701 bpf_link_put(link); 4702 return ret; 4703 } 4704 4705 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 4706 { 4707 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 4708 } 4709 4710 struct bpf_link *bpf_link_by_id(u32 id) 4711 { 4712 struct bpf_link *link; 4713 4714 if (!id) 4715 return ERR_PTR(-ENOENT); 4716 4717 spin_lock_bh(&link_idr_lock); 4718 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 4719 link = idr_find(&link_idr, id); 4720 if (link) { 4721 if (link->id) 4722 link = bpf_link_inc_not_zero(link); 4723 else 4724 link = ERR_PTR(-EAGAIN); 4725 } else { 4726 link = ERR_PTR(-ENOENT); 4727 } 4728 spin_unlock_bh(&link_idr_lock); 4729 return link; 4730 } 4731 4732 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 4733 { 4734 struct bpf_link *link; 4735 4736 spin_lock_bh(&link_idr_lock); 4737 again: 4738 link = idr_get_next(&link_idr, id); 4739 if (link) { 4740 link = bpf_link_inc_not_zero(link); 4741 if (IS_ERR(link)) { 4742 (*id)++; 4743 goto again; 4744 } 4745 } 4746 spin_unlock_bh(&link_idr_lock); 4747 4748 return link; 4749 } 4750 4751 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 4752 4753 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 4754 { 4755 struct bpf_link *link; 4756 u32 id = attr->link_id; 4757 int fd; 4758 4759 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 4760 return -EINVAL; 4761 4762 if (!capable(CAP_SYS_ADMIN)) 4763 return -EPERM; 4764 4765 link = bpf_link_by_id(id); 4766 if (IS_ERR(link)) 4767 return PTR_ERR(link); 4768 4769 fd = bpf_link_new_fd(link); 4770 if (fd < 0) 4771 bpf_link_put(link); 4772 4773 return fd; 4774 } 4775 4776 DEFINE_MUTEX(bpf_stats_enabled_mutex); 4777 4778 static int bpf_stats_release(struct inode *inode, struct file *file) 4779 { 4780 mutex_lock(&bpf_stats_enabled_mutex); 4781 static_key_slow_dec(&bpf_stats_enabled_key.key); 4782 mutex_unlock(&bpf_stats_enabled_mutex); 4783 return 0; 4784 } 4785 4786 static const struct file_operations bpf_stats_fops = { 4787 .release = bpf_stats_release, 4788 }; 4789 4790 static int bpf_enable_runtime_stats(void) 4791 { 4792 int fd; 4793 4794 mutex_lock(&bpf_stats_enabled_mutex); 4795 4796 /* Set a very high limit to avoid overflow */ 4797 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 4798 mutex_unlock(&bpf_stats_enabled_mutex); 4799 return -EBUSY; 4800 } 4801 4802 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 4803 if (fd >= 0) 4804 static_key_slow_inc(&bpf_stats_enabled_key.key); 4805 4806 mutex_unlock(&bpf_stats_enabled_mutex); 4807 return fd; 4808 } 4809 4810 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 4811 4812 static int bpf_enable_stats(union bpf_attr *attr) 4813 { 4814 4815 if (CHECK_ATTR(BPF_ENABLE_STATS)) 4816 return -EINVAL; 4817 4818 if (!capable(CAP_SYS_ADMIN)) 4819 return -EPERM; 4820 4821 switch (attr->enable_stats.type) { 4822 case BPF_STATS_RUN_TIME: 4823 return bpf_enable_runtime_stats(); 4824 default: 4825 break; 4826 } 4827 return -EINVAL; 4828 } 4829 4830 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 4831 4832 static int bpf_iter_create(union bpf_attr *attr) 4833 { 4834 struct bpf_link *link; 4835 int err; 4836 4837 if (CHECK_ATTR(BPF_ITER_CREATE)) 4838 return -EINVAL; 4839 4840 if (attr->iter_create.flags) 4841 return -EINVAL; 4842 4843 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 4844 if (IS_ERR(link)) 4845 return PTR_ERR(link); 4846 4847 err = bpf_iter_new_fd(link); 4848 bpf_link_put(link); 4849 4850 return err; 4851 } 4852 4853 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 4854 4855 static int bpf_prog_bind_map(union bpf_attr *attr) 4856 { 4857 struct bpf_prog *prog; 4858 struct bpf_map *map; 4859 struct bpf_map **used_maps_old, **used_maps_new; 4860 int i, ret = 0; 4861 4862 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 4863 return -EINVAL; 4864 4865 if (attr->prog_bind_map.flags) 4866 return -EINVAL; 4867 4868 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 4869 if (IS_ERR(prog)) 4870 return PTR_ERR(prog); 4871 4872 map = bpf_map_get(attr->prog_bind_map.map_fd); 4873 if (IS_ERR(map)) { 4874 ret = PTR_ERR(map); 4875 goto out_prog_put; 4876 } 4877 4878 mutex_lock(&prog->aux->used_maps_mutex); 4879 4880 used_maps_old = prog->aux->used_maps; 4881 4882 for (i = 0; i < prog->aux->used_map_cnt; i++) 4883 if (used_maps_old[i] == map) { 4884 bpf_map_put(map); 4885 goto out_unlock; 4886 } 4887 4888 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, 4889 sizeof(used_maps_new[0]), 4890 GFP_KERNEL); 4891 if (!used_maps_new) { 4892 ret = -ENOMEM; 4893 goto out_unlock; 4894 } 4895 4896 memcpy(used_maps_new, used_maps_old, 4897 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 4898 used_maps_new[prog->aux->used_map_cnt] = map; 4899 4900 prog->aux->used_map_cnt++; 4901 prog->aux->used_maps = used_maps_new; 4902 4903 kfree(used_maps_old); 4904 4905 out_unlock: 4906 mutex_unlock(&prog->aux->used_maps_mutex); 4907 4908 if (ret) 4909 bpf_map_put(map); 4910 out_prog_put: 4911 bpf_prog_put(prog); 4912 return ret; 4913 } 4914 4915 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size) 4916 { 4917 union bpf_attr attr; 4918 bool capable; 4919 int err; 4920 4921 capable = bpf_capable() || !sysctl_unprivileged_bpf_disabled; 4922 4923 /* Intent here is for unprivileged_bpf_disabled to block key object 4924 * creation commands for unprivileged users; other actions depend 4925 * of fd availability and access to bpffs, so are dependent on 4926 * object creation success. Capabilities are later verified for 4927 * operations such as load and map create, so even with unprivileged 4928 * BPF disabled, capability checks are still carried out for these 4929 * and other operations. 4930 */ 4931 if (!capable && 4932 (cmd == BPF_MAP_CREATE || cmd == BPF_PROG_LOAD)) 4933 return -EPERM; 4934 4935 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 4936 if (err) 4937 return err; 4938 size = min_t(u32, size, sizeof(attr)); 4939 4940 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 4941 memset(&attr, 0, sizeof(attr)); 4942 if (copy_from_bpfptr(&attr, uattr, size) != 0) 4943 return -EFAULT; 4944 4945 err = security_bpf(cmd, &attr, size); 4946 if (err < 0) 4947 return err; 4948 4949 switch (cmd) { 4950 case BPF_MAP_CREATE: 4951 err = map_create(&attr); 4952 break; 4953 case BPF_MAP_LOOKUP_ELEM: 4954 err = map_lookup_elem(&attr); 4955 break; 4956 case BPF_MAP_UPDATE_ELEM: 4957 err = map_update_elem(&attr, uattr); 4958 break; 4959 case BPF_MAP_DELETE_ELEM: 4960 err = map_delete_elem(&attr, uattr); 4961 break; 4962 case BPF_MAP_GET_NEXT_KEY: 4963 err = map_get_next_key(&attr); 4964 break; 4965 case BPF_MAP_FREEZE: 4966 err = map_freeze(&attr); 4967 break; 4968 case BPF_PROG_LOAD: 4969 err = bpf_prog_load(&attr, uattr); 4970 break; 4971 case BPF_OBJ_PIN: 4972 err = bpf_obj_pin(&attr); 4973 break; 4974 case BPF_OBJ_GET: 4975 err = bpf_obj_get(&attr); 4976 break; 4977 case BPF_PROG_ATTACH: 4978 err = bpf_prog_attach(&attr); 4979 break; 4980 case BPF_PROG_DETACH: 4981 err = bpf_prog_detach(&attr); 4982 break; 4983 case BPF_PROG_QUERY: 4984 err = bpf_prog_query(&attr, uattr.user); 4985 break; 4986 case BPF_PROG_TEST_RUN: 4987 err = bpf_prog_test_run(&attr, uattr.user); 4988 break; 4989 case BPF_PROG_GET_NEXT_ID: 4990 err = bpf_obj_get_next_id(&attr, uattr.user, 4991 &prog_idr, &prog_idr_lock); 4992 break; 4993 case BPF_MAP_GET_NEXT_ID: 4994 err = bpf_obj_get_next_id(&attr, uattr.user, 4995 &map_idr, &map_idr_lock); 4996 break; 4997 case BPF_BTF_GET_NEXT_ID: 4998 err = bpf_obj_get_next_id(&attr, uattr.user, 4999 &btf_idr, &btf_idr_lock); 5000 break; 5001 case BPF_PROG_GET_FD_BY_ID: 5002 err = bpf_prog_get_fd_by_id(&attr); 5003 break; 5004 case BPF_MAP_GET_FD_BY_ID: 5005 err = bpf_map_get_fd_by_id(&attr); 5006 break; 5007 case BPF_OBJ_GET_INFO_BY_FD: 5008 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 5009 break; 5010 case BPF_RAW_TRACEPOINT_OPEN: 5011 err = bpf_raw_tracepoint_open(&attr); 5012 break; 5013 case BPF_BTF_LOAD: 5014 err = bpf_btf_load(&attr, uattr); 5015 break; 5016 case BPF_BTF_GET_FD_BY_ID: 5017 err = bpf_btf_get_fd_by_id(&attr); 5018 break; 5019 case BPF_TASK_FD_QUERY: 5020 err = bpf_task_fd_query(&attr, uattr.user); 5021 break; 5022 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 5023 err = map_lookup_and_delete_elem(&attr); 5024 break; 5025 case BPF_MAP_LOOKUP_BATCH: 5026 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 5027 break; 5028 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 5029 err = bpf_map_do_batch(&attr, uattr.user, 5030 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 5031 break; 5032 case BPF_MAP_UPDATE_BATCH: 5033 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 5034 break; 5035 case BPF_MAP_DELETE_BATCH: 5036 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 5037 break; 5038 case BPF_LINK_CREATE: 5039 err = link_create(&attr, uattr); 5040 break; 5041 case BPF_LINK_UPDATE: 5042 err = link_update(&attr); 5043 break; 5044 case BPF_LINK_GET_FD_BY_ID: 5045 err = bpf_link_get_fd_by_id(&attr); 5046 break; 5047 case BPF_LINK_GET_NEXT_ID: 5048 err = bpf_obj_get_next_id(&attr, uattr.user, 5049 &link_idr, &link_idr_lock); 5050 break; 5051 case BPF_ENABLE_STATS: 5052 err = bpf_enable_stats(&attr); 5053 break; 5054 case BPF_ITER_CREATE: 5055 err = bpf_iter_create(&attr); 5056 break; 5057 case BPF_LINK_DETACH: 5058 err = link_detach(&attr); 5059 break; 5060 case BPF_PROG_BIND_MAP: 5061 err = bpf_prog_bind_map(&attr); 5062 break; 5063 default: 5064 err = -EINVAL; 5065 break; 5066 } 5067 5068 return err; 5069 } 5070 5071 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) 5072 { 5073 return __sys_bpf(cmd, USER_BPFPTR(uattr), size); 5074 } 5075 5076 static bool syscall_prog_is_valid_access(int off, int size, 5077 enum bpf_access_type type, 5078 const struct bpf_prog *prog, 5079 struct bpf_insn_access_aux *info) 5080 { 5081 if (off < 0 || off >= U16_MAX) 5082 return false; 5083 if (off % size != 0) 5084 return false; 5085 return true; 5086 } 5087 5088 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 5089 { 5090 switch (cmd) { 5091 case BPF_MAP_CREATE: 5092 case BPF_MAP_DELETE_ELEM: 5093 case BPF_MAP_UPDATE_ELEM: 5094 case BPF_MAP_FREEZE: 5095 case BPF_MAP_GET_FD_BY_ID: 5096 case BPF_PROG_LOAD: 5097 case BPF_BTF_LOAD: 5098 case BPF_LINK_CREATE: 5099 case BPF_RAW_TRACEPOINT_OPEN: 5100 break; 5101 default: 5102 return -EINVAL; 5103 } 5104 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); 5105 } 5106 5107 5108 /* To shut up -Wmissing-prototypes. 5109 * This function is used by the kernel light skeleton 5110 * to load bpf programs when modules are loaded or during kernel boot. 5111 * See tools/lib/bpf/skel_internal.h 5112 */ 5113 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 5114 5115 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 5116 { 5117 struct bpf_prog * __maybe_unused prog; 5118 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 5119 5120 switch (cmd) { 5121 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 5122 case BPF_PROG_TEST_RUN: 5123 if (attr->test.data_in || attr->test.data_out || 5124 attr->test.ctx_out || attr->test.duration || 5125 attr->test.repeat || attr->test.flags) 5126 return -EINVAL; 5127 5128 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 5129 if (IS_ERR(prog)) 5130 return PTR_ERR(prog); 5131 5132 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 5133 attr->test.ctx_size_in > U16_MAX) { 5134 bpf_prog_put(prog); 5135 return -EINVAL; 5136 } 5137 5138 run_ctx.bpf_cookie = 0; 5139 run_ctx.saved_run_ctx = NULL; 5140 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 5141 /* recursion detected */ 5142 bpf_prog_put(prog); 5143 return -EBUSY; 5144 } 5145 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 5146 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 5147 &run_ctx); 5148 bpf_prog_put(prog); 5149 return 0; 5150 #endif 5151 default: 5152 return ____bpf_sys_bpf(cmd, attr, size); 5153 } 5154 } 5155 EXPORT_SYMBOL(kern_sys_bpf); 5156 5157 static const struct bpf_func_proto bpf_sys_bpf_proto = { 5158 .func = bpf_sys_bpf, 5159 .gpl_only = false, 5160 .ret_type = RET_INTEGER, 5161 .arg1_type = ARG_ANYTHING, 5162 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 5163 .arg3_type = ARG_CONST_SIZE, 5164 }; 5165 5166 const struct bpf_func_proto * __weak 5167 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5168 { 5169 return bpf_base_func_proto(func_id); 5170 } 5171 5172 BPF_CALL_1(bpf_sys_close, u32, fd) 5173 { 5174 /* When bpf program calls this helper there should not be 5175 * an fdget() without matching completed fdput(). 5176 * This helper is allowed in the following callchain only: 5177 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 5178 */ 5179 return close_fd(fd); 5180 } 5181 5182 static const struct bpf_func_proto bpf_sys_close_proto = { 5183 .func = bpf_sys_close, 5184 .gpl_only = false, 5185 .ret_type = RET_INTEGER, 5186 .arg1_type = ARG_ANYTHING, 5187 }; 5188 5189 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 5190 { 5191 if (flags) 5192 return -EINVAL; 5193 5194 if (name_sz <= 1 || name[name_sz - 1]) 5195 return -EINVAL; 5196 5197 if (!bpf_dump_raw_ok(current_cred())) 5198 return -EPERM; 5199 5200 *res = kallsyms_lookup_name(name); 5201 return *res ? 0 : -ENOENT; 5202 } 5203 5204 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 5205 .func = bpf_kallsyms_lookup_name, 5206 .gpl_only = false, 5207 .ret_type = RET_INTEGER, 5208 .arg1_type = ARG_PTR_TO_MEM, 5209 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 5210 .arg3_type = ARG_ANYTHING, 5211 .arg4_type = ARG_PTR_TO_LONG, 5212 }; 5213 5214 static const struct bpf_func_proto * 5215 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5216 { 5217 switch (func_id) { 5218 case BPF_FUNC_sys_bpf: 5219 return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto; 5220 case BPF_FUNC_btf_find_by_name_kind: 5221 return &bpf_btf_find_by_name_kind_proto; 5222 case BPF_FUNC_sys_close: 5223 return &bpf_sys_close_proto; 5224 case BPF_FUNC_kallsyms_lookup_name: 5225 return &bpf_kallsyms_lookup_name_proto; 5226 default: 5227 return tracing_prog_func_proto(func_id, prog); 5228 } 5229 } 5230 5231 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 5232 .get_func_proto = syscall_prog_func_proto, 5233 .is_valid_access = syscall_prog_is_valid_access, 5234 }; 5235 5236 const struct bpf_prog_ops bpf_syscall_prog_ops = { 5237 .test_run = bpf_prog_test_run_syscall, 5238 }; 5239 5240 #ifdef CONFIG_SYSCTL 5241 static int bpf_stats_handler(struct ctl_table *table, int write, 5242 void *buffer, size_t *lenp, loff_t *ppos) 5243 { 5244 struct static_key *key = (struct static_key *)table->data; 5245 static int saved_val; 5246 int val, ret; 5247 struct ctl_table tmp = { 5248 .data = &val, 5249 .maxlen = sizeof(val), 5250 .mode = table->mode, 5251 .extra1 = SYSCTL_ZERO, 5252 .extra2 = SYSCTL_ONE, 5253 }; 5254 5255 if (write && !capable(CAP_SYS_ADMIN)) 5256 return -EPERM; 5257 5258 mutex_lock(&bpf_stats_enabled_mutex); 5259 val = saved_val; 5260 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5261 if (write && !ret && val != saved_val) { 5262 if (val) 5263 static_key_slow_inc(key); 5264 else 5265 static_key_slow_dec(key); 5266 saved_val = val; 5267 } 5268 mutex_unlock(&bpf_stats_enabled_mutex); 5269 return ret; 5270 } 5271 5272 void __weak unpriv_ebpf_notify(int new_state) 5273 { 5274 } 5275 5276 static int bpf_unpriv_handler(struct ctl_table *table, int write, 5277 void *buffer, size_t *lenp, loff_t *ppos) 5278 { 5279 int ret, unpriv_enable = *(int *)table->data; 5280 bool locked_state = unpriv_enable == 1; 5281 struct ctl_table tmp = *table; 5282 5283 if (write && !capable(CAP_SYS_ADMIN)) 5284 return -EPERM; 5285 5286 tmp.data = &unpriv_enable; 5287 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5288 if (write && !ret) { 5289 if (locked_state && unpriv_enable != 1) 5290 return -EPERM; 5291 *(int *)table->data = unpriv_enable; 5292 } 5293 5294 unpriv_ebpf_notify(unpriv_enable); 5295 5296 return ret; 5297 } 5298 5299 static struct ctl_table bpf_syscall_table[] = { 5300 { 5301 .procname = "unprivileged_bpf_disabled", 5302 .data = &sysctl_unprivileged_bpf_disabled, 5303 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 5304 .mode = 0644, 5305 .proc_handler = bpf_unpriv_handler, 5306 .extra1 = SYSCTL_ZERO, 5307 .extra2 = SYSCTL_TWO, 5308 }, 5309 { 5310 .procname = "bpf_stats_enabled", 5311 .data = &bpf_stats_enabled_key.key, 5312 .maxlen = sizeof(bpf_stats_enabled_key), 5313 .mode = 0644, 5314 .proc_handler = bpf_stats_handler, 5315 }, 5316 { } 5317 }; 5318 5319 static int __init bpf_syscall_sysctl_init(void) 5320 { 5321 register_sysctl_init("kernel", bpf_syscall_table); 5322 return 0; 5323 } 5324 late_initcall(bpf_syscall_sysctl_init); 5325 #endif /* CONFIG_SYSCTL */ 5326