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 #include <net/netfilter/nf_bpf_link.h> 39 40 #include <net/tcx.h> 41 42 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ 43 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ 44 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 45 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) 46 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) 47 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ 48 IS_FD_HASH(map)) 49 50 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) 51 52 DEFINE_PER_CPU(int, bpf_prog_active); 53 static DEFINE_IDR(prog_idr); 54 static DEFINE_SPINLOCK(prog_idr_lock); 55 static DEFINE_IDR(map_idr); 56 static DEFINE_SPINLOCK(map_idr_lock); 57 static DEFINE_IDR(link_idr); 58 static DEFINE_SPINLOCK(link_idr_lock); 59 60 int sysctl_unprivileged_bpf_disabled __read_mostly = 61 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; 62 63 static const struct bpf_map_ops * const bpf_map_types[] = { 64 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 65 #define BPF_MAP_TYPE(_id, _ops) \ 66 [_id] = &_ops, 67 #define BPF_LINK_TYPE(_id, _name) 68 #include <linux/bpf_types.h> 69 #undef BPF_PROG_TYPE 70 #undef BPF_MAP_TYPE 71 #undef BPF_LINK_TYPE 72 }; 73 74 /* 75 * If we're handed a bigger struct than we know of, ensure all the unknown bits 76 * are 0 - i.e. new user-space does not rely on any kernel feature extensions 77 * we don't know about yet. 78 * 79 * There is a ToCToU between this function call and the following 80 * copy_from_user() call. However, this is not a concern since this function is 81 * meant to be a future-proofing of bits. 82 */ 83 int bpf_check_uarg_tail_zero(bpfptr_t uaddr, 84 size_t expected_size, 85 size_t actual_size) 86 { 87 int res; 88 89 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ 90 return -E2BIG; 91 92 if (actual_size <= expected_size) 93 return 0; 94 95 if (uaddr.is_kernel) 96 res = memchr_inv(uaddr.kernel + expected_size, 0, 97 actual_size - expected_size) == NULL; 98 else 99 res = check_zeroed_user(uaddr.user + expected_size, 100 actual_size - expected_size); 101 if (res < 0) 102 return res; 103 return res ? 0 : -E2BIG; 104 } 105 106 const struct bpf_map_ops bpf_map_offload_ops = { 107 .map_meta_equal = bpf_map_meta_equal, 108 .map_alloc = bpf_map_offload_map_alloc, 109 .map_free = bpf_map_offload_map_free, 110 .map_check_btf = map_check_no_btf, 111 .map_mem_usage = bpf_map_offload_map_mem_usage, 112 }; 113 114 static void bpf_map_write_active_inc(struct bpf_map *map) 115 { 116 atomic64_inc(&map->writecnt); 117 } 118 119 static void bpf_map_write_active_dec(struct bpf_map *map) 120 { 121 atomic64_dec(&map->writecnt); 122 } 123 124 bool bpf_map_write_active(const struct bpf_map *map) 125 { 126 return atomic64_read(&map->writecnt) != 0; 127 } 128 129 static u32 bpf_map_value_size(const struct bpf_map *map) 130 { 131 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 132 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 133 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || 134 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) 135 return round_up(map->value_size, 8) * num_possible_cpus(); 136 else if (IS_FD_MAP(map)) 137 return sizeof(u32); 138 else 139 return map->value_size; 140 } 141 142 static void maybe_wait_bpf_programs(struct bpf_map *map) 143 { 144 /* Wait for any running BPF programs to complete so that 145 * userspace, when we return to it, knows that all programs 146 * that could be running use the new map value. 147 */ 148 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || 149 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 150 synchronize_rcu(); 151 } 152 153 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, 154 void *key, void *value, __u64 flags) 155 { 156 int err; 157 158 /* Need to create a kthread, thus must support schedule */ 159 if (bpf_map_is_offloaded(map)) { 160 return bpf_map_offload_update_elem(map, key, value, flags); 161 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || 162 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 163 return map->ops->map_update_elem(map, key, value, flags); 164 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || 165 map->map_type == BPF_MAP_TYPE_SOCKMAP) { 166 return sock_map_update_elem_sys(map, key, value, flags); 167 } else if (IS_FD_PROG_ARRAY(map)) { 168 return bpf_fd_array_map_update_elem(map, map_file, key, value, 169 flags); 170 } 171 172 bpf_disable_instrumentation(); 173 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 174 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 175 err = bpf_percpu_hash_update(map, key, value, flags); 176 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 177 err = bpf_percpu_array_update(map, key, value, flags); 178 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 179 err = bpf_percpu_cgroup_storage_update(map, key, value, 180 flags); 181 } else if (IS_FD_ARRAY(map)) { 182 rcu_read_lock(); 183 err = bpf_fd_array_map_update_elem(map, map_file, key, value, 184 flags); 185 rcu_read_unlock(); 186 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 187 rcu_read_lock(); 188 err = bpf_fd_htab_map_update_elem(map, map_file, key, value, 189 flags); 190 rcu_read_unlock(); 191 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 192 /* rcu_read_lock() is not needed */ 193 err = bpf_fd_reuseport_array_update_elem(map, key, value, 194 flags); 195 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 196 map->map_type == BPF_MAP_TYPE_STACK || 197 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 198 err = map->ops->map_push_elem(map, value, flags); 199 } else { 200 rcu_read_lock(); 201 err = map->ops->map_update_elem(map, key, value, flags); 202 rcu_read_unlock(); 203 } 204 bpf_enable_instrumentation(); 205 maybe_wait_bpf_programs(map); 206 207 return err; 208 } 209 210 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, 211 __u64 flags) 212 { 213 void *ptr; 214 int err; 215 216 if (bpf_map_is_offloaded(map)) 217 return bpf_map_offload_lookup_elem(map, key, value); 218 219 bpf_disable_instrumentation(); 220 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 221 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 222 err = bpf_percpu_hash_copy(map, key, value); 223 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 224 err = bpf_percpu_array_copy(map, key, value); 225 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 226 err = bpf_percpu_cgroup_storage_copy(map, key, value); 227 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 228 err = bpf_stackmap_copy(map, key, value); 229 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { 230 err = bpf_fd_array_map_lookup_elem(map, key, value); 231 } else if (IS_FD_HASH(map)) { 232 err = bpf_fd_htab_map_lookup_elem(map, key, value); 233 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 234 err = bpf_fd_reuseport_array_lookup_elem(map, key, value); 235 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 236 map->map_type == BPF_MAP_TYPE_STACK || 237 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 238 err = map->ops->map_peek_elem(map, value); 239 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 240 /* struct_ops map requires directly updating "value" */ 241 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value); 242 } else { 243 rcu_read_lock(); 244 if (map->ops->map_lookup_elem_sys_only) 245 ptr = map->ops->map_lookup_elem_sys_only(map, key); 246 else 247 ptr = map->ops->map_lookup_elem(map, key); 248 if (IS_ERR(ptr)) { 249 err = PTR_ERR(ptr); 250 } else if (!ptr) { 251 err = -ENOENT; 252 } else { 253 err = 0; 254 if (flags & BPF_F_LOCK) 255 /* lock 'ptr' and copy everything but lock */ 256 copy_map_value_locked(map, value, ptr, true); 257 else 258 copy_map_value(map, value, ptr); 259 /* mask lock and timer, since value wasn't zero inited */ 260 check_and_init_map_value(map, value); 261 } 262 rcu_read_unlock(); 263 } 264 265 bpf_enable_instrumentation(); 266 maybe_wait_bpf_programs(map); 267 268 return err; 269 } 270 271 /* Please, do not use this function outside from the map creation path 272 * (e.g. in map update path) without taking care of setting the active 273 * memory cgroup (see at bpf_map_kmalloc_node() for example). 274 */ 275 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) 276 { 277 /* We really just want to fail instead of triggering OOM killer 278 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, 279 * which is used for lower order allocation requests. 280 * 281 * It has been observed that higher order allocation requests done by 282 * vmalloc with __GFP_NORETRY being set might fail due to not trying 283 * to reclaim memory from the page cache, thus we set 284 * __GFP_RETRY_MAYFAIL to avoid such situations. 285 */ 286 287 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO); 288 unsigned int flags = 0; 289 unsigned long align = 1; 290 void *area; 291 292 if (size >= SIZE_MAX) 293 return NULL; 294 295 /* kmalloc()'ed memory can't be mmap()'ed */ 296 if (mmapable) { 297 BUG_ON(!PAGE_ALIGNED(size)); 298 align = SHMLBA; 299 flags = VM_USERMAP; 300 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { 301 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, 302 numa_node); 303 if (area != NULL) 304 return area; 305 } 306 307 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 308 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, 309 flags, numa_node, __builtin_return_address(0)); 310 } 311 312 void *bpf_map_area_alloc(u64 size, int numa_node) 313 { 314 return __bpf_map_area_alloc(size, numa_node, false); 315 } 316 317 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) 318 { 319 return __bpf_map_area_alloc(size, numa_node, true); 320 } 321 322 void bpf_map_area_free(void *area) 323 { 324 kvfree(area); 325 } 326 327 static u32 bpf_map_flags_retain_permanent(u32 flags) 328 { 329 /* Some map creation flags are not tied to the map object but 330 * rather to the map fd instead, so they have no meaning upon 331 * map object inspection since multiple file descriptors with 332 * different (access) properties can exist here. Thus, given 333 * this has zero meaning for the map itself, lets clear these 334 * from here. 335 */ 336 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); 337 } 338 339 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) 340 { 341 map->map_type = attr->map_type; 342 map->key_size = attr->key_size; 343 map->value_size = attr->value_size; 344 map->max_entries = attr->max_entries; 345 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); 346 map->numa_node = bpf_map_attr_numa_node(attr); 347 map->map_extra = attr->map_extra; 348 } 349 350 static int bpf_map_alloc_id(struct bpf_map *map) 351 { 352 int id; 353 354 idr_preload(GFP_KERNEL); 355 spin_lock_bh(&map_idr_lock); 356 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); 357 if (id > 0) 358 map->id = id; 359 spin_unlock_bh(&map_idr_lock); 360 idr_preload_end(); 361 362 if (WARN_ON_ONCE(!id)) 363 return -ENOSPC; 364 365 return id > 0 ? 0 : id; 366 } 367 368 void bpf_map_free_id(struct bpf_map *map) 369 { 370 unsigned long flags; 371 372 /* Offloaded maps are removed from the IDR store when their device 373 * disappears - even if someone holds an fd to them they are unusable, 374 * the memory is gone, all ops will fail; they are simply waiting for 375 * refcnt to drop to be freed. 376 */ 377 if (!map->id) 378 return; 379 380 spin_lock_irqsave(&map_idr_lock, flags); 381 382 idr_remove(&map_idr, map->id); 383 map->id = 0; 384 385 spin_unlock_irqrestore(&map_idr_lock, flags); 386 } 387 388 #ifdef CONFIG_MEMCG_KMEM 389 static void bpf_map_save_memcg(struct bpf_map *map) 390 { 391 /* Currently if a map is created by a process belonging to the root 392 * memory cgroup, get_obj_cgroup_from_current() will return NULL. 393 * So we have to check map->objcg for being NULL each time it's 394 * being used. 395 */ 396 if (memcg_bpf_enabled()) 397 map->objcg = get_obj_cgroup_from_current(); 398 } 399 400 static void bpf_map_release_memcg(struct bpf_map *map) 401 { 402 if (map->objcg) 403 obj_cgroup_put(map->objcg); 404 } 405 406 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) 407 { 408 if (map->objcg) 409 return get_mem_cgroup_from_objcg(map->objcg); 410 411 return root_mem_cgroup; 412 } 413 414 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, 415 int node) 416 { 417 struct mem_cgroup *memcg, *old_memcg; 418 void *ptr; 419 420 memcg = bpf_map_get_memcg(map); 421 old_memcg = set_active_memcg(memcg); 422 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); 423 set_active_memcg(old_memcg); 424 mem_cgroup_put(memcg); 425 426 return ptr; 427 } 428 429 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) 430 { 431 struct mem_cgroup *memcg, *old_memcg; 432 void *ptr; 433 434 memcg = bpf_map_get_memcg(map); 435 old_memcg = set_active_memcg(memcg); 436 ptr = kzalloc(size, flags | __GFP_ACCOUNT); 437 set_active_memcg(old_memcg); 438 mem_cgroup_put(memcg); 439 440 return ptr; 441 } 442 443 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, 444 gfp_t flags) 445 { 446 struct mem_cgroup *memcg, *old_memcg; 447 void *ptr; 448 449 memcg = bpf_map_get_memcg(map); 450 old_memcg = set_active_memcg(memcg); 451 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); 452 set_active_memcg(old_memcg); 453 mem_cgroup_put(memcg); 454 455 return ptr; 456 } 457 458 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, 459 size_t align, gfp_t flags) 460 { 461 struct mem_cgroup *memcg, *old_memcg; 462 void __percpu *ptr; 463 464 memcg = bpf_map_get_memcg(map); 465 old_memcg = set_active_memcg(memcg); 466 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); 467 set_active_memcg(old_memcg); 468 mem_cgroup_put(memcg); 469 470 return ptr; 471 } 472 473 #else 474 static void bpf_map_save_memcg(struct bpf_map *map) 475 { 476 } 477 478 static void bpf_map_release_memcg(struct bpf_map *map) 479 { 480 } 481 #endif 482 483 static int btf_field_cmp(const void *a, const void *b) 484 { 485 const struct btf_field *f1 = a, *f2 = b; 486 487 if (f1->offset < f2->offset) 488 return -1; 489 else if (f1->offset > f2->offset) 490 return 1; 491 return 0; 492 } 493 494 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 495 u32 field_mask) 496 { 497 struct btf_field *field; 498 499 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 500 return NULL; 501 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 502 if (!field || !(field->type & field_mask)) 503 return NULL; 504 return field; 505 } 506 507 void btf_record_free(struct btf_record *rec) 508 { 509 int i; 510 511 if (IS_ERR_OR_NULL(rec)) 512 return; 513 for (i = 0; i < rec->cnt; i++) { 514 switch (rec->fields[i].type) { 515 case BPF_KPTR_UNREF: 516 case BPF_KPTR_REF: 517 case BPF_KPTR_PERCPU: 518 if (rec->fields[i].kptr.module) 519 module_put(rec->fields[i].kptr.module); 520 btf_put(rec->fields[i].kptr.btf); 521 break; 522 case BPF_LIST_HEAD: 523 case BPF_LIST_NODE: 524 case BPF_RB_ROOT: 525 case BPF_RB_NODE: 526 case BPF_SPIN_LOCK: 527 case BPF_TIMER: 528 case BPF_REFCOUNT: 529 /* Nothing to release */ 530 break; 531 default: 532 WARN_ON_ONCE(1); 533 continue; 534 } 535 } 536 kfree(rec); 537 } 538 539 void bpf_map_free_record(struct bpf_map *map) 540 { 541 btf_record_free(map->record); 542 map->record = NULL; 543 } 544 545 struct btf_record *btf_record_dup(const struct btf_record *rec) 546 { 547 const struct btf_field *fields; 548 struct btf_record *new_rec; 549 int ret, size, i; 550 551 if (IS_ERR_OR_NULL(rec)) 552 return NULL; 553 size = offsetof(struct btf_record, fields[rec->cnt]); 554 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 555 if (!new_rec) 556 return ERR_PTR(-ENOMEM); 557 /* Do a deep copy of the btf_record */ 558 fields = rec->fields; 559 new_rec->cnt = 0; 560 for (i = 0; i < rec->cnt; i++) { 561 switch (fields[i].type) { 562 case BPF_KPTR_UNREF: 563 case BPF_KPTR_REF: 564 case BPF_KPTR_PERCPU: 565 btf_get(fields[i].kptr.btf); 566 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 567 ret = -ENXIO; 568 goto free; 569 } 570 break; 571 case BPF_LIST_HEAD: 572 case BPF_LIST_NODE: 573 case BPF_RB_ROOT: 574 case BPF_RB_NODE: 575 case BPF_SPIN_LOCK: 576 case BPF_TIMER: 577 case BPF_REFCOUNT: 578 /* Nothing to acquire */ 579 break; 580 default: 581 ret = -EFAULT; 582 WARN_ON_ONCE(1); 583 goto free; 584 } 585 new_rec->cnt++; 586 } 587 return new_rec; 588 free: 589 btf_record_free(new_rec); 590 return ERR_PTR(ret); 591 } 592 593 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 594 { 595 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 596 int size; 597 598 if (!a_has_fields && !b_has_fields) 599 return true; 600 if (a_has_fields != b_has_fields) 601 return false; 602 if (rec_a->cnt != rec_b->cnt) 603 return false; 604 size = offsetof(struct btf_record, fields[rec_a->cnt]); 605 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 606 * members are zeroed out. So memcmp is safe to do without worrying 607 * about padding/unused fields. 608 * 609 * While spin_lock, timer, and kptr have no relation to map BTF, 610 * list_head metadata is specific to map BTF, the btf and value_rec 611 * members in particular. btf is the map BTF, while value_rec points to 612 * btf_record in that map BTF. 613 * 614 * So while by default, we don't rely on the map BTF (which the records 615 * were parsed from) matching for both records, which is not backwards 616 * compatible, in case list_head is part of it, we implicitly rely on 617 * that by way of depending on memcmp succeeding for it. 618 */ 619 return !memcmp(rec_a, rec_b, size); 620 } 621 622 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 623 { 624 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 625 return; 626 bpf_timer_cancel_and_free(obj + rec->timer_off); 627 } 628 629 extern void __bpf_obj_drop_impl(void *p, const struct btf_record *rec); 630 631 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 632 { 633 const struct btf_field *fields; 634 int i; 635 636 if (IS_ERR_OR_NULL(rec)) 637 return; 638 fields = rec->fields; 639 for (i = 0; i < rec->cnt; i++) { 640 struct btf_struct_meta *pointee_struct_meta; 641 const struct btf_field *field = &fields[i]; 642 void *field_ptr = obj + field->offset; 643 void *xchgd_field; 644 645 switch (fields[i].type) { 646 case BPF_SPIN_LOCK: 647 break; 648 case BPF_TIMER: 649 bpf_timer_cancel_and_free(field_ptr); 650 break; 651 case BPF_KPTR_UNREF: 652 WRITE_ONCE(*(u64 *)field_ptr, 0); 653 break; 654 case BPF_KPTR_REF: 655 case BPF_KPTR_PERCPU: 656 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); 657 if (!xchgd_field) 658 break; 659 660 if (!btf_is_kernel(field->kptr.btf)) { 661 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, 662 field->kptr.btf_id); 663 migrate_disable(); 664 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? 665 pointee_struct_meta->record : 666 NULL); 667 migrate_enable(); 668 } else { 669 field->kptr.dtor(xchgd_field); 670 } 671 break; 672 case BPF_LIST_HEAD: 673 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 674 continue; 675 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 676 break; 677 case BPF_RB_ROOT: 678 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 679 continue; 680 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); 681 break; 682 case BPF_LIST_NODE: 683 case BPF_RB_NODE: 684 case BPF_REFCOUNT: 685 break; 686 default: 687 WARN_ON_ONCE(1); 688 continue; 689 } 690 } 691 } 692 693 /* called from workqueue */ 694 static void bpf_map_free_deferred(struct work_struct *work) 695 { 696 struct bpf_map *map = container_of(work, struct bpf_map, work); 697 struct btf_record *rec = map->record; 698 699 security_bpf_map_free(map); 700 bpf_map_release_memcg(map); 701 /* implementation dependent freeing */ 702 map->ops->map_free(map); 703 /* Delay freeing of btf_record for maps, as map_free 704 * callback usually needs access to them. It is better to do it here 705 * than require each callback to do the free itself manually. 706 * 707 * Note that the btf_record stashed in map->inner_map_meta->record was 708 * already freed using the map_free callback for map in map case which 709 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 710 * template bpf_map struct used during verification. 711 */ 712 btf_record_free(rec); 713 } 714 715 static void bpf_map_put_uref(struct bpf_map *map) 716 { 717 if (atomic64_dec_and_test(&map->usercnt)) { 718 if (map->ops->map_release_uref) 719 map->ops->map_release_uref(map); 720 } 721 } 722 723 /* decrement map refcnt and schedule it for freeing via workqueue 724 * (underlying map implementation ops->map_free() might sleep) 725 */ 726 void bpf_map_put(struct bpf_map *map) 727 { 728 if (atomic64_dec_and_test(&map->refcnt)) { 729 /* bpf_map_free_id() must be called first */ 730 bpf_map_free_id(map); 731 btf_put(map->btf); 732 INIT_WORK(&map->work, bpf_map_free_deferred); 733 /* Avoid spawning kworkers, since they all might contend 734 * for the same mutex like slab_mutex. 735 */ 736 queue_work(system_unbound_wq, &map->work); 737 } 738 } 739 EXPORT_SYMBOL_GPL(bpf_map_put); 740 741 void bpf_map_put_with_uref(struct bpf_map *map) 742 { 743 bpf_map_put_uref(map); 744 bpf_map_put(map); 745 } 746 747 static int bpf_map_release(struct inode *inode, struct file *filp) 748 { 749 struct bpf_map *map = filp->private_data; 750 751 if (map->ops->map_release) 752 map->ops->map_release(map, filp); 753 754 bpf_map_put_with_uref(map); 755 return 0; 756 } 757 758 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 759 { 760 fmode_t mode = f.file->f_mode; 761 762 /* Our file permissions may have been overridden by global 763 * map permissions facing syscall side. 764 */ 765 if (READ_ONCE(map->frozen)) 766 mode &= ~FMODE_CAN_WRITE; 767 return mode; 768 } 769 770 #ifdef CONFIG_PROC_FS 771 /* Show the memory usage of a bpf map */ 772 static u64 bpf_map_memory_usage(const struct bpf_map *map) 773 { 774 return map->ops->map_mem_usage(map); 775 } 776 777 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 778 { 779 struct bpf_map *map = filp->private_data; 780 u32 type = 0, jited = 0; 781 782 if (map_type_contains_progs(map)) { 783 spin_lock(&map->owner.lock); 784 type = map->owner.type; 785 jited = map->owner.jited; 786 spin_unlock(&map->owner.lock); 787 } 788 789 seq_printf(m, 790 "map_type:\t%u\n" 791 "key_size:\t%u\n" 792 "value_size:\t%u\n" 793 "max_entries:\t%u\n" 794 "map_flags:\t%#x\n" 795 "map_extra:\t%#llx\n" 796 "memlock:\t%llu\n" 797 "map_id:\t%u\n" 798 "frozen:\t%u\n", 799 map->map_type, 800 map->key_size, 801 map->value_size, 802 map->max_entries, 803 map->map_flags, 804 (unsigned long long)map->map_extra, 805 bpf_map_memory_usage(map), 806 map->id, 807 READ_ONCE(map->frozen)); 808 if (type) { 809 seq_printf(m, "owner_prog_type:\t%u\n", type); 810 seq_printf(m, "owner_jited:\t%u\n", jited); 811 } 812 } 813 #endif 814 815 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 816 loff_t *ppos) 817 { 818 /* We need this handler such that alloc_file() enables 819 * f_mode with FMODE_CAN_READ. 820 */ 821 return -EINVAL; 822 } 823 824 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 825 size_t siz, loff_t *ppos) 826 { 827 /* We need this handler such that alloc_file() enables 828 * f_mode with FMODE_CAN_WRITE. 829 */ 830 return -EINVAL; 831 } 832 833 /* called for any extra memory-mapped regions (except initial) */ 834 static void bpf_map_mmap_open(struct vm_area_struct *vma) 835 { 836 struct bpf_map *map = vma->vm_file->private_data; 837 838 if (vma->vm_flags & VM_MAYWRITE) 839 bpf_map_write_active_inc(map); 840 } 841 842 /* called for all unmapped memory region (including initial) */ 843 static void bpf_map_mmap_close(struct vm_area_struct *vma) 844 { 845 struct bpf_map *map = vma->vm_file->private_data; 846 847 if (vma->vm_flags & VM_MAYWRITE) 848 bpf_map_write_active_dec(map); 849 } 850 851 static const struct vm_operations_struct bpf_map_default_vmops = { 852 .open = bpf_map_mmap_open, 853 .close = bpf_map_mmap_close, 854 }; 855 856 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 857 { 858 struct bpf_map *map = filp->private_data; 859 int err; 860 861 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 862 return -ENOTSUPP; 863 864 if (!(vma->vm_flags & VM_SHARED)) 865 return -EINVAL; 866 867 mutex_lock(&map->freeze_mutex); 868 869 if (vma->vm_flags & VM_WRITE) { 870 if (map->frozen) { 871 err = -EPERM; 872 goto out; 873 } 874 /* map is meant to be read-only, so do not allow mapping as 875 * writable, because it's possible to leak a writable page 876 * reference and allows user-space to still modify it after 877 * freezing, while verifier will assume contents do not change 878 */ 879 if (map->map_flags & BPF_F_RDONLY_PROG) { 880 err = -EACCES; 881 goto out; 882 } 883 } 884 885 /* set default open/close callbacks */ 886 vma->vm_ops = &bpf_map_default_vmops; 887 vma->vm_private_data = map; 888 vm_flags_clear(vma, VM_MAYEXEC); 889 if (!(vma->vm_flags & VM_WRITE)) 890 /* disallow re-mapping with PROT_WRITE */ 891 vm_flags_clear(vma, VM_MAYWRITE); 892 893 err = map->ops->map_mmap(map, vma); 894 if (err) 895 goto out; 896 897 if (vma->vm_flags & VM_MAYWRITE) 898 bpf_map_write_active_inc(map); 899 out: 900 mutex_unlock(&map->freeze_mutex); 901 return err; 902 } 903 904 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 905 { 906 struct bpf_map *map = filp->private_data; 907 908 if (map->ops->map_poll) 909 return map->ops->map_poll(map, filp, pts); 910 911 return EPOLLERR; 912 } 913 914 const struct file_operations bpf_map_fops = { 915 #ifdef CONFIG_PROC_FS 916 .show_fdinfo = bpf_map_show_fdinfo, 917 #endif 918 .release = bpf_map_release, 919 .read = bpf_dummy_read, 920 .write = bpf_dummy_write, 921 .mmap = bpf_map_mmap, 922 .poll = bpf_map_poll, 923 }; 924 925 int bpf_map_new_fd(struct bpf_map *map, int flags) 926 { 927 int ret; 928 929 ret = security_bpf_map(map, OPEN_FMODE(flags)); 930 if (ret < 0) 931 return ret; 932 933 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 934 flags | O_CLOEXEC); 935 } 936 937 int bpf_get_file_flag(int flags) 938 { 939 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 940 return -EINVAL; 941 if (flags & BPF_F_RDONLY) 942 return O_RDONLY; 943 if (flags & BPF_F_WRONLY) 944 return O_WRONLY; 945 return O_RDWR; 946 } 947 948 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 949 #define CHECK_ATTR(CMD) \ 950 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 951 sizeof(attr->CMD##_LAST_FIELD), 0, \ 952 sizeof(*attr) - \ 953 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 954 sizeof(attr->CMD##_LAST_FIELD)) != NULL 955 956 /* dst and src must have at least "size" number of bytes. 957 * Return strlen on success and < 0 on error. 958 */ 959 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 960 { 961 const char *end = src + size; 962 const char *orig_src = src; 963 964 memset(dst, 0, size); 965 /* Copy all isalnum(), '_' and '.' chars. */ 966 while (src < end && *src) { 967 if (!isalnum(*src) && 968 *src != '_' && *src != '.') 969 return -EINVAL; 970 *dst++ = *src++; 971 } 972 973 /* No '\0' found in "size" number of bytes */ 974 if (src == end) 975 return -EINVAL; 976 977 return src - orig_src; 978 } 979 980 int map_check_no_btf(const struct bpf_map *map, 981 const struct btf *btf, 982 const struct btf_type *key_type, 983 const struct btf_type *value_type) 984 { 985 return -ENOTSUPP; 986 } 987 988 static int map_check_btf(struct bpf_map *map, const struct btf *btf, 989 u32 btf_key_id, u32 btf_value_id) 990 { 991 const struct btf_type *key_type, *value_type; 992 u32 key_size, value_size; 993 int ret = 0; 994 995 /* Some maps allow key to be unspecified. */ 996 if (btf_key_id) { 997 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 998 if (!key_type || key_size != map->key_size) 999 return -EINVAL; 1000 } else { 1001 key_type = btf_type_by_id(btf, 0); 1002 if (!map->ops->map_check_btf) 1003 return -EINVAL; 1004 } 1005 1006 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1007 if (!value_type || value_size != map->value_size) 1008 return -EINVAL; 1009 1010 map->record = btf_parse_fields(btf, value_type, 1011 BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1012 BPF_RB_ROOT | BPF_REFCOUNT, 1013 map->value_size); 1014 if (!IS_ERR_OR_NULL(map->record)) { 1015 int i; 1016 1017 if (!bpf_capable()) { 1018 ret = -EPERM; 1019 goto free_map_tab; 1020 } 1021 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1022 ret = -EACCES; 1023 goto free_map_tab; 1024 } 1025 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1026 switch (map->record->field_mask & (1 << i)) { 1027 case 0: 1028 continue; 1029 case BPF_SPIN_LOCK: 1030 if (map->map_type != BPF_MAP_TYPE_HASH && 1031 map->map_type != BPF_MAP_TYPE_ARRAY && 1032 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1033 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1034 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1035 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1036 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1037 ret = -EOPNOTSUPP; 1038 goto free_map_tab; 1039 } 1040 break; 1041 case BPF_TIMER: 1042 if (map->map_type != BPF_MAP_TYPE_HASH && 1043 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1044 map->map_type != BPF_MAP_TYPE_ARRAY) { 1045 ret = -EOPNOTSUPP; 1046 goto free_map_tab; 1047 } 1048 break; 1049 case BPF_KPTR_UNREF: 1050 case BPF_KPTR_REF: 1051 case BPF_KPTR_PERCPU: 1052 case BPF_REFCOUNT: 1053 if (map->map_type != BPF_MAP_TYPE_HASH && 1054 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1055 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1056 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1057 map->map_type != BPF_MAP_TYPE_ARRAY && 1058 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1059 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1060 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1061 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1062 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1063 ret = -EOPNOTSUPP; 1064 goto free_map_tab; 1065 } 1066 break; 1067 case BPF_LIST_HEAD: 1068 case BPF_RB_ROOT: 1069 if (map->map_type != BPF_MAP_TYPE_HASH && 1070 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1071 map->map_type != BPF_MAP_TYPE_ARRAY) { 1072 ret = -EOPNOTSUPP; 1073 goto free_map_tab; 1074 } 1075 break; 1076 default: 1077 /* Fail if map_type checks are missing for a field type */ 1078 ret = -EOPNOTSUPP; 1079 goto free_map_tab; 1080 } 1081 } 1082 } 1083 1084 ret = btf_check_and_fixup_fields(btf, map->record); 1085 if (ret < 0) 1086 goto free_map_tab; 1087 1088 if (map->ops->map_check_btf) { 1089 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1090 if (ret < 0) 1091 goto free_map_tab; 1092 } 1093 1094 return ret; 1095 free_map_tab: 1096 bpf_map_free_record(map); 1097 return ret; 1098 } 1099 1100 #define BPF_MAP_CREATE_LAST_FIELD map_extra 1101 /* called via syscall */ 1102 static int map_create(union bpf_attr *attr) 1103 { 1104 const struct bpf_map_ops *ops; 1105 int numa_node = bpf_map_attr_numa_node(attr); 1106 u32 map_type = attr->map_type; 1107 struct bpf_map *map; 1108 int f_flags; 1109 int err; 1110 1111 err = CHECK_ATTR(BPF_MAP_CREATE); 1112 if (err) 1113 return -EINVAL; 1114 1115 if (attr->btf_vmlinux_value_type_id) { 1116 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || 1117 attr->btf_key_type_id || attr->btf_value_type_id) 1118 return -EINVAL; 1119 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1120 return -EINVAL; 1121 } 1122 1123 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1124 attr->map_extra != 0) 1125 return -EINVAL; 1126 1127 f_flags = bpf_get_file_flag(attr->map_flags); 1128 if (f_flags < 0) 1129 return f_flags; 1130 1131 if (numa_node != NUMA_NO_NODE && 1132 ((unsigned int)numa_node >= nr_node_ids || 1133 !node_online(numa_node))) 1134 return -EINVAL; 1135 1136 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1137 map_type = attr->map_type; 1138 if (map_type >= ARRAY_SIZE(bpf_map_types)) 1139 return -EINVAL; 1140 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1141 ops = bpf_map_types[map_type]; 1142 if (!ops) 1143 return -EINVAL; 1144 1145 if (ops->map_alloc_check) { 1146 err = ops->map_alloc_check(attr); 1147 if (err) 1148 return err; 1149 } 1150 if (attr->map_ifindex) 1151 ops = &bpf_map_offload_ops; 1152 if (!ops->map_mem_usage) 1153 return -EINVAL; 1154 1155 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1156 * creation for unprivileged users; other actions depend 1157 * on fd availability and access to bpffs, so are dependent on 1158 * object creation success. Even with unprivileged BPF disabled, 1159 * capability checks are still carried out. 1160 */ 1161 if (sysctl_unprivileged_bpf_disabled && !bpf_capable()) 1162 return -EPERM; 1163 1164 /* check privileged map type permissions */ 1165 switch (map_type) { 1166 case BPF_MAP_TYPE_ARRAY: 1167 case BPF_MAP_TYPE_PERCPU_ARRAY: 1168 case BPF_MAP_TYPE_PROG_ARRAY: 1169 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1170 case BPF_MAP_TYPE_CGROUP_ARRAY: 1171 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1172 case BPF_MAP_TYPE_HASH: 1173 case BPF_MAP_TYPE_PERCPU_HASH: 1174 case BPF_MAP_TYPE_HASH_OF_MAPS: 1175 case BPF_MAP_TYPE_RINGBUF: 1176 case BPF_MAP_TYPE_USER_RINGBUF: 1177 case BPF_MAP_TYPE_CGROUP_STORAGE: 1178 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1179 /* unprivileged */ 1180 break; 1181 case BPF_MAP_TYPE_SK_STORAGE: 1182 case BPF_MAP_TYPE_INODE_STORAGE: 1183 case BPF_MAP_TYPE_TASK_STORAGE: 1184 case BPF_MAP_TYPE_CGRP_STORAGE: 1185 case BPF_MAP_TYPE_BLOOM_FILTER: 1186 case BPF_MAP_TYPE_LPM_TRIE: 1187 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1188 case BPF_MAP_TYPE_STACK_TRACE: 1189 case BPF_MAP_TYPE_QUEUE: 1190 case BPF_MAP_TYPE_STACK: 1191 case BPF_MAP_TYPE_LRU_HASH: 1192 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1193 case BPF_MAP_TYPE_STRUCT_OPS: 1194 case BPF_MAP_TYPE_CPUMAP: 1195 if (!bpf_capable()) 1196 return -EPERM; 1197 break; 1198 case BPF_MAP_TYPE_SOCKMAP: 1199 case BPF_MAP_TYPE_SOCKHASH: 1200 case BPF_MAP_TYPE_DEVMAP: 1201 case BPF_MAP_TYPE_DEVMAP_HASH: 1202 case BPF_MAP_TYPE_XSKMAP: 1203 if (!capable(CAP_NET_ADMIN)) 1204 return -EPERM; 1205 break; 1206 default: 1207 WARN(1, "unsupported map type %d", map_type); 1208 return -EPERM; 1209 } 1210 1211 map = ops->map_alloc(attr); 1212 if (IS_ERR(map)) 1213 return PTR_ERR(map); 1214 map->ops = ops; 1215 map->map_type = map_type; 1216 1217 err = bpf_obj_name_cpy(map->name, attr->map_name, 1218 sizeof(attr->map_name)); 1219 if (err < 0) 1220 goto free_map; 1221 1222 atomic64_set(&map->refcnt, 1); 1223 atomic64_set(&map->usercnt, 1); 1224 mutex_init(&map->freeze_mutex); 1225 spin_lock_init(&map->owner.lock); 1226 1227 if (attr->btf_key_type_id || attr->btf_value_type_id || 1228 /* Even the map's value is a kernel's struct, 1229 * the bpf_prog.o must have BTF to begin with 1230 * to figure out the corresponding kernel's 1231 * counter part. Thus, attr->btf_fd has 1232 * to be valid also. 1233 */ 1234 attr->btf_vmlinux_value_type_id) { 1235 struct btf *btf; 1236 1237 btf = btf_get_by_fd(attr->btf_fd); 1238 if (IS_ERR(btf)) { 1239 err = PTR_ERR(btf); 1240 goto free_map; 1241 } 1242 if (btf_is_kernel(btf)) { 1243 btf_put(btf); 1244 err = -EACCES; 1245 goto free_map; 1246 } 1247 map->btf = btf; 1248 1249 if (attr->btf_value_type_id) { 1250 err = map_check_btf(map, btf, attr->btf_key_type_id, 1251 attr->btf_value_type_id); 1252 if (err) 1253 goto free_map; 1254 } 1255 1256 map->btf_key_type_id = attr->btf_key_type_id; 1257 map->btf_value_type_id = attr->btf_value_type_id; 1258 map->btf_vmlinux_value_type_id = 1259 attr->btf_vmlinux_value_type_id; 1260 } 1261 1262 err = security_bpf_map_alloc(map); 1263 if (err) 1264 goto free_map; 1265 1266 err = bpf_map_alloc_id(map); 1267 if (err) 1268 goto free_map_sec; 1269 1270 bpf_map_save_memcg(map); 1271 1272 err = bpf_map_new_fd(map, f_flags); 1273 if (err < 0) { 1274 /* failed to allocate fd. 1275 * bpf_map_put_with_uref() is needed because the above 1276 * bpf_map_alloc_id() has published the map 1277 * to the userspace and the userspace may 1278 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1279 */ 1280 bpf_map_put_with_uref(map); 1281 return err; 1282 } 1283 1284 return err; 1285 1286 free_map_sec: 1287 security_bpf_map_free(map); 1288 free_map: 1289 btf_put(map->btf); 1290 map->ops->map_free(map); 1291 return err; 1292 } 1293 1294 /* if error is returned, fd is released. 1295 * On success caller should complete fd access with matching fdput() 1296 */ 1297 struct bpf_map *__bpf_map_get(struct fd f) 1298 { 1299 if (!f.file) 1300 return ERR_PTR(-EBADF); 1301 if (f.file->f_op != &bpf_map_fops) { 1302 fdput(f); 1303 return ERR_PTR(-EINVAL); 1304 } 1305 1306 return f.file->private_data; 1307 } 1308 1309 void bpf_map_inc(struct bpf_map *map) 1310 { 1311 atomic64_inc(&map->refcnt); 1312 } 1313 EXPORT_SYMBOL_GPL(bpf_map_inc); 1314 1315 void bpf_map_inc_with_uref(struct bpf_map *map) 1316 { 1317 atomic64_inc(&map->refcnt); 1318 atomic64_inc(&map->usercnt); 1319 } 1320 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1321 1322 struct bpf_map *bpf_map_get(u32 ufd) 1323 { 1324 struct fd f = fdget(ufd); 1325 struct bpf_map *map; 1326 1327 map = __bpf_map_get(f); 1328 if (IS_ERR(map)) 1329 return map; 1330 1331 bpf_map_inc(map); 1332 fdput(f); 1333 1334 return map; 1335 } 1336 EXPORT_SYMBOL(bpf_map_get); 1337 1338 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1339 { 1340 struct fd f = fdget(ufd); 1341 struct bpf_map *map; 1342 1343 map = __bpf_map_get(f); 1344 if (IS_ERR(map)) 1345 return map; 1346 1347 bpf_map_inc_with_uref(map); 1348 fdput(f); 1349 1350 return map; 1351 } 1352 1353 /* map_idr_lock should have been held or the map should have been 1354 * protected by rcu read lock. 1355 */ 1356 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1357 { 1358 int refold; 1359 1360 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1361 if (!refold) 1362 return ERR_PTR(-ENOENT); 1363 if (uref) 1364 atomic64_inc(&map->usercnt); 1365 1366 return map; 1367 } 1368 1369 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1370 { 1371 spin_lock_bh(&map_idr_lock); 1372 map = __bpf_map_inc_not_zero(map, false); 1373 spin_unlock_bh(&map_idr_lock); 1374 1375 return map; 1376 } 1377 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1378 1379 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) 1380 { 1381 return -ENOTSUPP; 1382 } 1383 1384 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1385 { 1386 if (key_size) 1387 return vmemdup_user(ukey, key_size); 1388 1389 if (ukey) 1390 return ERR_PTR(-EINVAL); 1391 1392 return NULL; 1393 } 1394 1395 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1396 { 1397 if (key_size) 1398 return kvmemdup_bpfptr(ukey, key_size); 1399 1400 if (!bpfptr_is_null(ukey)) 1401 return ERR_PTR(-EINVAL); 1402 1403 return NULL; 1404 } 1405 1406 /* last field in 'union bpf_attr' used by this command */ 1407 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1408 1409 static int map_lookup_elem(union bpf_attr *attr) 1410 { 1411 void __user *ukey = u64_to_user_ptr(attr->key); 1412 void __user *uvalue = u64_to_user_ptr(attr->value); 1413 int ufd = attr->map_fd; 1414 struct bpf_map *map; 1415 void *key, *value; 1416 u32 value_size; 1417 struct fd f; 1418 int err; 1419 1420 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1421 return -EINVAL; 1422 1423 if (attr->flags & ~BPF_F_LOCK) 1424 return -EINVAL; 1425 1426 f = fdget(ufd); 1427 map = __bpf_map_get(f); 1428 if (IS_ERR(map)) 1429 return PTR_ERR(map); 1430 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1431 err = -EPERM; 1432 goto err_put; 1433 } 1434 1435 if ((attr->flags & BPF_F_LOCK) && 1436 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1437 err = -EINVAL; 1438 goto err_put; 1439 } 1440 1441 key = __bpf_copy_key(ukey, map->key_size); 1442 if (IS_ERR(key)) { 1443 err = PTR_ERR(key); 1444 goto err_put; 1445 } 1446 1447 value_size = bpf_map_value_size(map); 1448 1449 err = -ENOMEM; 1450 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1451 if (!value) 1452 goto free_key; 1453 1454 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1455 if (copy_from_user(value, uvalue, value_size)) 1456 err = -EFAULT; 1457 else 1458 err = bpf_map_copy_value(map, key, value, attr->flags); 1459 goto free_value; 1460 } 1461 1462 err = bpf_map_copy_value(map, key, value, attr->flags); 1463 if (err) 1464 goto free_value; 1465 1466 err = -EFAULT; 1467 if (copy_to_user(uvalue, value, value_size) != 0) 1468 goto free_value; 1469 1470 err = 0; 1471 1472 free_value: 1473 kvfree(value); 1474 free_key: 1475 kvfree(key); 1476 err_put: 1477 fdput(f); 1478 return err; 1479 } 1480 1481 1482 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1483 1484 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1485 { 1486 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1487 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1488 int ufd = attr->map_fd; 1489 struct bpf_map *map; 1490 void *key, *value; 1491 u32 value_size; 1492 struct fd f; 1493 int err; 1494 1495 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1496 return -EINVAL; 1497 1498 f = fdget(ufd); 1499 map = __bpf_map_get(f); 1500 if (IS_ERR(map)) 1501 return PTR_ERR(map); 1502 bpf_map_write_active_inc(map); 1503 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1504 err = -EPERM; 1505 goto err_put; 1506 } 1507 1508 if ((attr->flags & BPF_F_LOCK) && 1509 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1510 err = -EINVAL; 1511 goto err_put; 1512 } 1513 1514 key = ___bpf_copy_key(ukey, map->key_size); 1515 if (IS_ERR(key)) { 1516 err = PTR_ERR(key); 1517 goto err_put; 1518 } 1519 1520 value_size = bpf_map_value_size(map); 1521 value = kvmemdup_bpfptr(uvalue, value_size); 1522 if (IS_ERR(value)) { 1523 err = PTR_ERR(value); 1524 goto free_key; 1525 } 1526 1527 err = bpf_map_update_value(map, f.file, key, value, attr->flags); 1528 1529 kvfree(value); 1530 free_key: 1531 kvfree(key); 1532 err_put: 1533 bpf_map_write_active_dec(map); 1534 fdput(f); 1535 return err; 1536 } 1537 1538 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1539 1540 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1541 { 1542 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1543 int ufd = attr->map_fd; 1544 struct bpf_map *map; 1545 struct fd f; 1546 void *key; 1547 int err; 1548 1549 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1550 return -EINVAL; 1551 1552 f = fdget(ufd); 1553 map = __bpf_map_get(f); 1554 if (IS_ERR(map)) 1555 return PTR_ERR(map); 1556 bpf_map_write_active_inc(map); 1557 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1558 err = -EPERM; 1559 goto err_put; 1560 } 1561 1562 key = ___bpf_copy_key(ukey, map->key_size); 1563 if (IS_ERR(key)) { 1564 err = PTR_ERR(key); 1565 goto err_put; 1566 } 1567 1568 if (bpf_map_is_offloaded(map)) { 1569 err = bpf_map_offload_delete_elem(map, key); 1570 goto out; 1571 } else if (IS_FD_PROG_ARRAY(map) || 1572 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1573 /* These maps require sleepable context */ 1574 err = map->ops->map_delete_elem(map, key); 1575 goto out; 1576 } 1577 1578 bpf_disable_instrumentation(); 1579 rcu_read_lock(); 1580 err = map->ops->map_delete_elem(map, key); 1581 rcu_read_unlock(); 1582 bpf_enable_instrumentation(); 1583 maybe_wait_bpf_programs(map); 1584 out: 1585 kvfree(key); 1586 err_put: 1587 bpf_map_write_active_dec(map); 1588 fdput(f); 1589 return err; 1590 } 1591 1592 /* last field in 'union bpf_attr' used by this command */ 1593 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1594 1595 static int map_get_next_key(union bpf_attr *attr) 1596 { 1597 void __user *ukey = u64_to_user_ptr(attr->key); 1598 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1599 int ufd = attr->map_fd; 1600 struct bpf_map *map; 1601 void *key, *next_key; 1602 struct fd f; 1603 int err; 1604 1605 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1606 return -EINVAL; 1607 1608 f = fdget(ufd); 1609 map = __bpf_map_get(f); 1610 if (IS_ERR(map)) 1611 return PTR_ERR(map); 1612 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1613 err = -EPERM; 1614 goto err_put; 1615 } 1616 1617 if (ukey) { 1618 key = __bpf_copy_key(ukey, map->key_size); 1619 if (IS_ERR(key)) { 1620 err = PTR_ERR(key); 1621 goto err_put; 1622 } 1623 } else { 1624 key = NULL; 1625 } 1626 1627 err = -ENOMEM; 1628 next_key = kvmalloc(map->key_size, GFP_USER); 1629 if (!next_key) 1630 goto free_key; 1631 1632 if (bpf_map_is_offloaded(map)) { 1633 err = bpf_map_offload_get_next_key(map, key, next_key); 1634 goto out; 1635 } 1636 1637 rcu_read_lock(); 1638 err = map->ops->map_get_next_key(map, key, next_key); 1639 rcu_read_unlock(); 1640 out: 1641 if (err) 1642 goto free_next_key; 1643 1644 err = -EFAULT; 1645 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1646 goto free_next_key; 1647 1648 err = 0; 1649 1650 free_next_key: 1651 kvfree(next_key); 1652 free_key: 1653 kvfree(key); 1654 err_put: 1655 fdput(f); 1656 return err; 1657 } 1658 1659 int generic_map_delete_batch(struct bpf_map *map, 1660 const union bpf_attr *attr, 1661 union bpf_attr __user *uattr) 1662 { 1663 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1664 u32 cp, max_count; 1665 int err = 0; 1666 void *key; 1667 1668 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1669 return -EINVAL; 1670 1671 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1672 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1673 return -EINVAL; 1674 } 1675 1676 max_count = attr->batch.count; 1677 if (!max_count) 1678 return 0; 1679 1680 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1681 if (!key) 1682 return -ENOMEM; 1683 1684 for (cp = 0; cp < max_count; cp++) { 1685 err = -EFAULT; 1686 if (copy_from_user(key, keys + cp * map->key_size, 1687 map->key_size)) 1688 break; 1689 1690 if (bpf_map_is_offloaded(map)) { 1691 err = bpf_map_offload_delete_elem(map, key); 1692 break; 1693 } 1694 1695 bpf_disable_instrumentation(); 1696 rcu_read_lock(); 1697 err = map->ops->map_delete_elem(map, key); 1698 rcu_read_unlock(); 1699 bpf_enable_instrumentation(); 1700 if (err) 1701 break; 1702 cond_resched(); 1703 } 1704 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1705 err = -EFAULT; 1706 1707 kvfree(key); 1708 1709 maybe_wait_bpf_programs(map); 1710 return err; 1711 } 1712 1713 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 1714 const union bpf_attr *attr, 1715 union bpf_attr __user *uattr) 1716 { 1717 void __user *values = u64_to_user_ptr(attr->batch.values); 1718 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1719 u32 value_size, cp, max_count; 1720 void *key, *value; 1721 int err = 0; 1722 1723 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1724 return -EINVAL; 1725 1726 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1727 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1728 return -EINVAL; 1729 } 1730 1731 value_size = bpf_map_value_size(map); 1732 1733 max_count = attr->batch.count; 1734 if (!max_count) 1735 return 0; 1736 1737 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1738 if (!key) 1739 return -ENOMEM; 1740 1741 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1742 if (!value) { 1743 kvfree(key); 1744 return -ENOMEM; 1745 } 1746 1747 for (cp = 0; cp < max_count; cp++) { 1748 err = -EFAULT; 1749 if (copy_from_user(key, keys + cp * map->key_size, 1750 map->key_size) || 1751 copy_from_user(value, values + cp * value_size, value_size)) 1752 break; 1753 1754 err = bpf_map_update_value(map, map_file, key, value, 1755 attr->batch.elem_flags); 1756 1757 if (err) 1758 break; 1759 cond_resched(); 1760 } 1761 1762 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1763 err = -EFAULT; 1764 1765 kvfree(value); 1766 kvfree(key); 1767 return err; 1768 } 1769 1770 #define MAP_LOOKUP_RETRIES 3 1771 1772 int generic_map_lookup_batch(struct bpf_map *map, 1773 const union bpf_attr *attr, 1774 union bpf_attr __user *uattr) 1775 { 1776 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 1777 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 1778 void __user *values = u64_to_user_ptr(attr->batch.values); 1779 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1780 void *buf, *buf_prevkey, *prev_key, *key, *value; 1781 int err, retry = MAP_LOOKUP_RETRIES; 1782 u32 value_size, cp, max_count; 1783 1784 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1785 return -EINVAL; 1786 1787 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1788 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 1789 return -EINVAL; 1790 1791 value_size = bpf_map_value_size(map); 1792 1793 max_count = attr->batch.count; 1794 if (!max_count) 1795 return 0; 1796 1797 if (put_user(0, &uattr->batch.count)) 1798 return -EFAULT; 1799 1800 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1801 if (!buf_prevkey) 1802 return -ENOMEM; 1803 1804 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 1805 if (!buf) { 1806 kvfree(buf_prevkey); 1807 return -ENOMEM; 1808 } 1809 1810 err = -EFAULT; 1811 prev_key = NULL; 1812 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 1813 goto free_buf; 1814 key = buf; 1815 value = key + map->key_size; 1816 if (ubatch) 1817 prev_key = buf_prevkey; 1818 1819 for (cp = 0; cp < max_count;) { 1820 rcu_read_lock(); 1821 err = map->ops->map_get_next_key(map, prev_key, key); 1822 rcu_read_unlock(); 1823 if (err) 1824 break; 1825 err = bpf_map_copy_value(map, key, value, 1826 attr->batch.elem_flags); 1827 1828 if (err == -ENOENT) { 1829 if (retry) { 1830 retry--; 1831 continue; 1832 } 1833 err = -EINTR; 1834 break; 1835 } 1836 1837 if (err) 1838 goto free_buf; 1839 1840 if (copy_to_user(keys + cp * map->key_size, key, 1841 map->key_size)) { 1842 err = -EFAULT; 1843 goto free_buf; 1844 } 1845 if (copy_to_user(values + cp * value_size, value, value_size)) { 1846 err = -EFAULT; 1847 goto free_buf; 1848 } 1849 1850 if (!prev_key) 1851 prev_key = buf_prevkey; 1852 1853 swap(prev_key, key); 1854 retry = MAP_LOOKUP_RETRIES; 1855 cp++; 1856 cond_resched(); 1857 } 1858 1859 if (err == -EFAULT) 1860 goto free_buf; 1861 1862 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 1863 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 1864 err = -EFAULT; 1865 1866 free_buf: 1867 kvfree(buf_prevkey); 1868 kvfree(buf); 1869 return err; 1870 } 1871 1872 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 1873 1874 static int map_lookup_and_delete_elem(union bpf_attr *attr) 1875 { 1876 void __user *ukey = u64_to_user_ptr(attr->key); 1877 void __user *uvalue = u64_to_user_ptr(attr->value); 1878 int ufd = attr->map_fd; 1879 struct bpf_map *map; 1880 void *key, *value; 1881 u32 value_size; 1882 struct fd f; 1883 int err; 1884 1885 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 1886 return -EINVAL; 1887 1888 if (attr->flags & ~BPF_F_LOCK) 1889 return -EINVAL; 1890 1891 f = fdget(ufd); 1892 map = __bpf_map_get(f); 1893 if (IS_ERR(map)) 1894 return PTR_ERR(map); 1895 bpf_map_write_active_inc(map); 1896 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 1897 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1898 err = -EPERM; 1899 goto err_put; 1900 } 1901 1902 if (attr->flags && 1903 (map->map_type == BPF_MAP_TYPE_QUEUE || 1904 map->map_type == BPF_MAP_TYPE_STACK)) { 1905 err = -EINVAL; 1906 goto err_put; 1907 } 1908 1909 if ((attr->flags & BPF_F_LOCK) && 1910 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1911 err = -EINVAL; 1912 goto err_put; 1913 } 1914 1915 key = __bpf_copy_key(ukey, map->key_size); 1916 if (IS_ERR(key)) { 1917 err = PTR_ERR(key); 1918 goto err_put; 1919 } 1920 1921 value_size = bpf_map_value_size(map); 1922 1923 err = -ENOMEM; 1924 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1925 if (!value) 1926 goto free_key; 1927 1928 err = -ENOTSUPP; 1929 if (map->map_type == BPF_MAP_TYPE_QUEUE || 1930 map->map_type == BPF_MAP_TYPE_STACK) { 1931 err = map->ops->map_pop_elem(map, value); 1932 } else if (map->map_type == BPF_MAP_TYPE_HASH || 1933 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 1934 map->map_type == BPF_MAP_TYPE_LRU_HASH || 1935 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 1936 if (!bpf_map_is_offloaded(map)) { 1937 bpf_disable_instrumentation(); 1938 rcu_read_lock(); 1939 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 1940 rcu_read_unlock(); 1941 bpf_enable_instrumentation(); 1942 } 1943 } 1944 1945 if (err) 1946 goto free_value; 1947 1948 if (copy_to_user(uvalue, value, value_size) != 0) { 1949 err = -EFAULT; 1950 goto free_value; 1951 } 1952 1953 err = 0; 1954 1955 free_value: 1956 kvfree(value); 1957 free_key: 1958 kvfree(key); 1959 err_put: 1960 bpf_map_write_active_dec(map); 1961 fdput(f); 1962 return err; 1963 } 1964 1965 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 1966 1967 static int map_freeze(const union bpf_attr *attr) 1968 { 1969 int err = 0, ufd = attr->map_fd; 1970 struct bpf_map *map; 1971 struct fd f; 1972 1973 if (CHECK_ATTR(BPF_MAP_FREEZE)) 1974 return -EINVAL; 1975 1976 f = fdget(ufd); 1977 map = __bpf_map_get(f); 1978 if (IS_ERR(map)) 1979 return PTR_ERR(map); 1980 1981 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) { 1982 fdput(f); 1983 return -ENOTSUPP; 1984 } 1985 1986 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1987 fdput(f); 1988 return -EPERM; 1989 } 1990 1991 mutex_lock(&map->freeze_mutex); 1992 if (bpf_map_write_active(map)) { 1993 err = -EBUSY; 1994 goto err_put; 1995 } 1996 if (READ_ONCE(map->frozen)) { 1997 err = -EBUSY; 1998 goto err_put; 1999 } 2000 2001 WRITE_ONCE(map->frozen, true); 2002 err_put: 2003 mutex_unlock(&map->freeze_mutex); 2004 fdput(f); 2005 return err; 2006 } 2007 2008 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2009 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2010 [_id] = & _name ## _prog_ops, 2011 #define BPF_MAP_TYPE(_id, _ops) 2012 #define BPF_LINK_TYPE(_id, _name) 2013 #include <linux/bpf_types.h> 2014 #undef BPF_PROG_TYPE 2015 #undef BPF_MAP_TYPE 2016 #undef BPF_LINK_TYPE 2017 }; 2018 2019 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2020 { 2021 const struct bpf_prog_ops *ops; 2022 2023 if (type >= ARRAY_SIZE(bpf_prog_types)) 2024 return -EINVAL; 2025 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2026 ops = bpf_prog_types[type]; 2027 if (!ops) 2028 return -EINVAL; 2029 2030 if (!bpf_prog_is_offloaded(prog->aux)) 2031 prog->aux->ops = ops; 2032 else 2033 prog->aux->ops = &bpf_offload_prog_ops; 2034 prog->type = type; 2035 return 0; 2036 } 2037 2038 enum bpf_audit { 2039 BPF_AUDIT_LOAD, 2040 BPF_AUDIT_UNLOAD, 2041 BPF_AUDIT_MAX, 2042 }; 2043 2044 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2045 [BPF_AUDIT_LOAD] = "LOAD", 2046 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2047 }; 2048 2049 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2050 { 2051 struct audit_context *ctx = NULL; 2052 struct audit_buffer *ab; 2053 2054 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2055 return; 2056 if (audit_enabled == AUDIT_OFF) 2057 return; 2058 if (!in_irq() && !irqs_disabled()) 2059 ctx = audit_context(); 2060 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2061 if (unlikely(!ab)) 2062 return; 2063 audit_log_format(ab, "prog-id=%u op=%s", 2064 prog->aux->id, bpf_audit_str[op]); 2065 audit_log_end(ab); 2066 } 2067 2068 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2069 { 2070 int id; 2071 2072 idr_preload(GFP_KERNEL); 2073 spin_lock_bh(&prog_idr_lock); 2074 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2075 if (id > 0) 2076 prog->aux->id = id; 2077 spin_unlock_bh(&prog_idr_lock); 2078 idr_preload_end(); 2079 2080 /* id is in [1, INT_MAX) */ 2081 if (WARN_ON_ONCE(!id)) 2082 return -ENOSPC; 2083 2084 return id > 0 ? 0 : id; 2085 } 2086 2087 void bpf_prog_free_id(struct bpf_prog *prog) 2088 { 2089 unsigned long flags; 2090 2091 /* cBPF to eBPF migrations are currently not in the idr store. 2092 * Offloaded programs are removed from the store when their device 2093 * disappears - even if someone grabs an fd to them they are unusable, 2094 * simply waiting for refcnt to drop to be freed. 2095 */ 2096 if (!prog->aux->id) 2097 return; 2098 2099 spin_lock_irqsave(&prog_idr_lock, flags); 2100 idr_remove(&prog_idr, prog->aux->id); 2101 prog->aux->id = 0; 2102 spin_unlock_irqrestore(&prog_idr_lock, flags); 2103 } 2104 2105 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2106 { 2107 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2108 2109 kvfree(aux->func_info); 2110 kfree(aux->func_info_aux); 2111 free_uid(aux->user); 2112 security_bpf_prog_free(aux); 2113 bpf_prog_free(aux->prog); 2114 } 2115 2116 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2117 { 2118 bpf_prog_kallsyms_del_all(prog); 2119 btf_put(prog->aux->btf); 2120 module_put(prog->aux->mod); 2121 kvfree(prog->aux->jited_linfo); 2122 kvfree(prog->aux->linfo); 2123 kfree(prog->aux->kfunc_tab); 2124 if (prog->aux->attach_btf) 2125 btf_put(prog->aux->attach_btf); 2126 2127 if (deferred) { 2128 if (prog->aux->sleepable) 2129 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2130 else 2131 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2132 } else { 2133 __bpf_prog_put_rcu(&prog->aux->rcu); 2134 } 2135 } 2136 2137 static void bpf_prog_put_deferred(struct work_struct *work) 2138 { 2139 struct bpf_prog_aux *aux; 2140 struct bpf_prog *prog; 2141 2142 aux = container_of(work, struct bpf_prog_aux, work); 2143 prog = aux->prog; 2144 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2145 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2146 bpf_prog_free_id(prog); 2147 __bpf_prog_put_noref(prog, true); 2148 } 2149 2150 static void __bpf_prog_put(struct bpf_prog *prog) 2151 { 2152 struct bpf_prog_aux *aux = prog->aux; 2153 2154 if (atomic64_dec_and_test(&aux->refcnt)) { 2155 if (in_irq() || irqs_disabled()) { 2156 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2157 schedule_work(&aux->work); 2158 } else { 2159 bpf_prog_put_deferred(&aux->work); 2160 } 2161 } 2162 } 2163 2164 void bpf_prog_put(struct bpf_prog *prog) 2165 { 2166 __bpf_prog_put(prog); 2167 } 2168 EXPORT_SYMBOL_GPL(bpf_prog_put); 2169 2170 static int bpf_prog_release(struct inode *inode, struct file *filp) 2171 { 2172 struct bpf_prog *prog = filp->private_data; 2173 2174 bpf_prog_put(prog); 2175 return 0; 2176 } 2177 2178 struct bpf_prog_kstats { 2179 u64 nsecs; 2180 u64 cnt; 2181 u64 misses; 2182 }; 2183 2184 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2185 { 2186 struct bpf_prog_stats *stats; 2187 unsigned int flags; 2188 2189 stats = this_cpu_ptr(prog->stats); 2190 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2191 u64_stats_inc(&stats->misses); 2192 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2193 } 2194 2195 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2196 struct bpf_prog_kstats *stats) 2197 { 2198 u64 nsecs = 0, cnt = 0, misses = 0; 2199 int cpu; 2200 2201 for_each_possible_cpu(cpu) { 2202 const struct bpf_prog_stats *st; 2203 unsigned int start; 2204 u64 tnsecs, tcnt, tmisses; 2205 2206 st = per_cpu_ptr(prog->stats, cpu); 2207 do { 2208 start = u64_stats_fetch_begin(&st->syncp); 2209 tnsecs = u64_stats_read(&st->nsecs); 2210 tcnt = u64_stats_read(&st->cnt); 2211 tmisses = u64_stats_read(&st->misses); 2212 } while (u64_stats_fetch_retry(&st->syncp, start)); 2213 nsecs += tnsecs; 2214 cnt += tcnt; 2215 misses += tmisses; 2216 } 2217 stats->nsecs = nsecs; 2218 stats->cnt = cnt; 2219 stats->misses = misses; 2220 } 2221 2222 #ifdef CONFIG_PROC_FS 2223 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2224 { 2225 const struct bpf_prog *prog = filp->private_data; 2226 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2227 struct bpf_prog_kstats stats; 2228 2229 bpf_prog_get_stats(prog, &stats); 2230 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2231 seq_printf(m, 2232 "prog_type:\t%u\n" 2233 "prog_jited:\t%u\n" 2234 "prog_tag:\t%s\n" 2235 "memlock:\t%llu\n" 2236 "prog_id:\t%u\n" 2237 "run_time_ns:\t%llu\n" 2238 "run_cnt:\t%llu\n" 2239 "recursion_misses:\t%llu\n" 2240 "verified_insns:\t%u\n", 2241 prog->type, 2242 prog->jited, 2243 prog_tag, 2244 prog->pages * 1ULL << PAGE_SHIFT, 2245 prog->aux->id, 2246 stats.nsecs, 2247 stats.cnt, 2248 stats.misses, 2249 prog->aux->verified_insns); 2250 } 2251 #endif 2252 2253 const struct file_operations bpf_prog_fops = { 2254 #ifdef CONFIG_PROC_FS 2255 .show_fdinfo = bpf_prog_show_fdinfo, 2256 #endif 2257 .release = bpf_prog_release, 2258 .read = bpf_dummy_read, 2259 .write = bpf_dummy_write, 2260 }; 2261 2262 int bpf_prog_new_fd(struct bpf_prog *prog) 2263 { 2264 int ret; 2265 2266 ret = security_bpf_prog(prog); 2267 if (ret < 0) 2268 return ret; 2269 2270 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2271 O_RDWR | O_CLOEXEC); 2272 } 2273 2274 static struct bpf_prog *____bpf_prog_get(struct fd f) 2275 { 2276 if (!f.file) 2277 return ERR_PTR(-EBADF); 2278 if (f.file->f_op != &bpf_prog_fops) { 2279 fdput(f); 2280 return ERR_PTR(-EINVAL); 2281 } 2282 2283 return f.file->private_data; 2284 } 2285 2286 void bpf_prog_add(struct bpf_prog *prog, int i) 2287 { 2288 atomic64_add(i, &prog->aux->refcnt); 2289 } 2290 EXPORT_SYMBOL_GPL(bpf_prog_add); 2291 2292 void bpf_prog_sub(struct bpf_prog *prog, int i) 2293 { 2294 /* Only to be used for undoing previous bpf_prog_add() in some 2295 * error path. We still know that another entity in our call 2296 * path holds a reference to the program, thus atomic_sub() can 2297 * be safely used in such cases! 2298 */ 2299 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2300 } 2301 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2302 2303 void bpf_prog_inc(struct bpf_prog *prog) 2304 { 2305 atomic64_inc(&prog->aux->refcnt); 2306 } 2307 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2308 2309 /* prog_idr_lock should have been held */ 2310 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2311 { 2312 int refold; 2313 2314 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2315 2316 if (!refold) 2317 return ERR_PTR(-ENOENT); 2318 2319 return prog; 2320 } 2321 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2322 2323 bool bpf_prog_get_ok(struct bpf_prog *prog, 2324 enum bpf_prog_type *attach_type, bool attach_drv) 2325 { 2326 /* not an attachment, just a refcount inc, always allow */ 2327 if (!attach_type) 2328 return true; 2329 2330 if (prog->type != *attach_type) 2331 return false; 2332 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2333 return false; 2334 2335 return true; 2336 } 2337 2338 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2339 bool attach_drv) 2340 { 2341 struct fd f = fdget(ufd); 2342 struct bpf_prog *prog; 2343 2344 prog = ____bpf_prog_get(f); 2345 if (IS_ERR(prog)) 2346 return prog; 2347 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) { 2348 prog = ERR_PTR(-EINVAL); 2349 goto out; 2350 } 2351 2352 bpf_prog_inc(prog); 2353 out: 2354 fdput(f); 2355 return prog; 2356 } 2357 2358 struct bpf_prog *bpf_prog_get(u32 ufd) 2359 { 2360 return __bpf_prog_get(ufd, NULL, false); 2361 } 2362 2363 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2364 bool attach_drv) 2365 { 2366 return __bpf_prog_get(ufd, &type, attach_drv); 2367 } 2368 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2369 2370 /* Initially all BPF programs could be loaded w/o specifying 2371 * expected_attach_type. Later for some of them specifying expected_attach_type 2372 * at load time became required so that program could be validated properly. 2373 * Programs of types that are allowed to be loaded both w/ and w/o (for 2374 * backward compatibility) expected_attach_type, should have the default attach 2375 * type assigned to expected_attach_type for the latter case, so that it can be 2376 * validated later at attach time. 2377 * 2378 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2379 * prog type requires it but has some attach types that have to be backward 2380 * compatible. 2381 */ 2382 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2383 { 2384 switch (attr->prog_type) { 2385 case BPF_PROG_TYPE_CGROUP_SOCK: 2386 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2387 * exist so checking for non-zero is the way to go here. 2388 */ 2389 if (!attr->expected_attach_type) 2390 attr->expected_attach_type = 2391 BPF_CGROUP_INET_SOCK_CREATE; 2392 break; 2393 case BPF_PROG_TYPE_SK_REUSEPORT: 2394 if (!attr->expected_attach_type) 2395 attr->expected_attach_type = 2396 BPF_SK_REUSEPORT_SELECT; 2397 break; 2398 } 2399 } 2400 2401 static int 2402 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2403 enum bpf_attach_type expected_attach_type, 2404 struct btf *attach_btf, u32 btf_id, 2405 struct bpf_prog *dst_prog) 2406 { 2407 if (btf_id) { 2408 if (btf_id > BTF_MAX_TYPE) 2409 return -EINVAL; 2410 2411 if (!attach_btf && !dst_prog) 2412 return -EINVAL; 2413 2414 switch (prog_type) { 2415 case BPF_PROG_TYPE_TRACING: 2416 case BPF_PROG_TYPE_LSM: 2417 case BPF_PROG_TYPE_STRUCT_OPS: 2418 case BPF_PROG_TYPE_EXT: 2419 break; 2420 default: 2421 return -EINVAL; 2422 } 2423 } 2424 2425 if (attach_btf && (!btf_id || dst_prog)) 2426 return -EINVAL; 2427 2428 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2429 prog_type != BPF_PROG_TYPE_EXT) 2430 return -EINVAL; 2431 2432 switch (prog_type) { 2433 case BPF_PROG_TYPE_CGROUP_SOCK: 2434 switch (expected_attach_type) { 2435 case BPF_CGROUP_INET_SOCK_CREATE: 2436 case BPF_CGROUP_INET_SOCK_RELEASE: 2437 case BPF_CGROUP_INET4_POST_BIND: 2438 case BPF_CGROUP_INET6_POST_BIND: 2439 return 0; 2440 default: 2441 return -EINVAL; 2442 } 2443 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2444 switch (expected_attach_type) { 2445 case BPF_CGROUP_INET4_BIND: 2446 case BPF_CGROUP_INET6_BIND: 2447 case BPF_CGROUP_INET4_CONNECT: 2448 case BPF_CGROUP_INET6_CONNECT: 2449 case BPF_CGROUP_UNIX_CONNECT: 2450 case BPF_CGROUP_INET4_GETPEERNAME: 2451 case BPF_CGROUP_INET6_GETPEERNAME: 2452 case BPF_CGROUP_UNIX_GETPEERNAME: 2453 case BPF_CGROUP_INET4_GETSOCKNAME: 2454 case BPF_CGROUP_INET6_GETSOCKNAME: 2455 case BPF_CGROUP_UNIX_GETSOCKNAME: 2456 case BPF_CGROUP_UDP4_SENDMSG: 2457 case BPF_CGROUP_UDP6_SENDMSG: 2458 case BPF_CGROUP_UNIX_SENDMSG: 2459 case BPF_CGROUP_UDP4_RECVMSG: 2460 case BPF_CGROUP_UDP6_RECVMSG: 2461 case BPF_CGROUP_UNIX_RECVMSG: 2462 return 0; 2463 default: 2464 return -EINVAL; 2465 } 2466 case BPF_PROG_TYPE_CGROUP_SKB: 2467 switch (expected_attach_type) { 2468 case BPF_CGROUP_INET_INGRESS: 2469 case BPF_CGROUP_INET_EGRESS: 2470 return 0; 2471 default: 2472 return -EINVAL; 2473 } 2474 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2475 switch (expected_attach_type) { 2476 case BPF_CGROUP_SETSOCKOPT: 2477 case BPF_CGROUP_GETSOCKOPT: 2478 return 0; 2479 default: 2480 return -EINVAL; 2481 } 2482 case BPF_PROG_TYPE_SK_LOOKUP: 2483 if (expected_attach_type == BPF_SK_LOOKUP) 2484 return 0; 2485 return -EINVAL; 2486 case BPF_PROG_TYPE_SK_REUSEPORT: 2487 switch (expected_attach_type) { 2488 case BPF_SK_REUSEPORT_SELECT: 2489 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2490 return 0; 2491 default: 2492 return -EINVAL; 2493 } 2494 case BPF_PROG_TYPE_NETFILTER: 2495 if (expected_attach_type == BPF_NETFILTER) 2496 return 0; 2497 return -EINVAL; 2498 case BPF_PROG_TYPE_SYSCALL: 2499 case BPF_PROG_TYPE_EXT: 2500 if (expected_attach_type) 2501 return -EINVAL; 2502 fallthrough; 2503 default: 2504 return 0; 2505 } 2506 } 2507 2508 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2509 { 2510 switch (prog_type) { 2511 case BPF_PROG_TYPE_SCHED_CLS: 2512 case BPF_PROG_TYPE_SCHED_ACT: 2513 case BPF_PROG_TYPE_XDP: 2514 case BPF_PROG_TYPE_LWT_IN: 2515 case BPF_PROG_TYPE_LWT_OUT: 2516 case BPF_PROG_TYPE_LWT_XMIT: 2517 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2518 case BPF_PROG_TYPE_SK_SKB: 2519 case BPF_PROG_TYPE_SK_MSG: 2520 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2521 case BPF_PROG_TYPE_CGROUP_DEVICE: 2522 case BPF_PROG_TYPE_CGROUP_SOCK: 2523 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2524 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2525 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2526 case BPF_PROG_TYPE_SOCK_OPS: 2527 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2528 case BPF_PROG_TYPE_NETFILTER: 2529 return true; 2530 case BPF_PROG_TYPE_CGROUP_SKB: 2531 /* always unpriv */ 2532 case BPF_PROG_TYPE_SK_REUSEPORT: 2533 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2534 default: 2535 return false; 2536 } 2537 } 2538 2539 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2540 { 2541 switch (prog_type) { 2542 case BPF_PROG_TYPE_KPROBE: 2543 case BPF_PROG_TYPE_TRACEPOINT: 2544 case BPF_PROG_TYPE_PERF_EVENT: 2545 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2546 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2547 case BPF_PROG_TYPE_TRACING: 2548 case BPF_PROG_TYPE_LSM: 2549 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2550 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2551 return true; 2552 default: 2553 return false; 2554 } 2555 } 2556 2557 /* last field in 'union bpf_attr' used by this command */ 2558 #define BPF_PROG_LOAD_LAST_FIELD log_true_size 2559 2560 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) 2561 { 2562 enum bpf_prog_type type = attr->prog_type; 2563 struct bpf_prog *prog, *dst_prog = NULL; 2564 struct btf *attach_btf = NULL; 2565 int err; 2566 char license[128]; 2567 2568 if (CHECK_ATTR(BPF_PROG_LOAD)) 2569 return -EINVAL; 2570 2571 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2572 BPF_F_ANY_ALIGNMENT | 2573 BPF_F_TEST_STATE_FREQ | 2574 BPF_F_SLEEPABLE | 2575 BPF_F_TEST_RND_HI32 | 2576 BPF_F_XDP_HAS_FRAGS | 2577 BPF_F_XDP_DEV_BOUND_ONLY)) 2578 return -EINVAL; 2579 2580 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2581 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2582 !bpf_capable()) 2583 return -EPERM; 2584 2585 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2586 * creation for unprivileged users; other actions depend 2587 * on fd availability and access to bpffs, so are dependent on 2588 * object creation success. Even with unprivileged BPF disabled, 2589 * capability checks are still carried out for these 2590 * and other operations. 2591 */ 2592 if (sysctl_unprivileged_bpf_disabled && !bpf_capable()) 2593 return -EPERM; 2594 2595 if (attr->insn_cnt == 0 || 2596 attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) 2597 return -E2BIG; 2598 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2599 type != BPF_PROG_TYPE_CGROUP_SKB && 2600 !bpf_capable()) 2601 return -EPERM; 2602 2603 if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN)) 2604 return -EPERM; 2605 if (is_perfmon_prog_type(type) && !perfmon_capable()) 2606 return -EPERM; 2607 2608 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 2609 * or btf, we need to check which one it is 2610 */ 2611 if (attr->attach_prog_fd) { 2612 dst_prog = bpf_prog_get(attr->attach_prog_fd); 2613 if (IS_ERR(dst_prog)) { 2614 dst_prog = NULL; 2615 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 2616 if (IS_ERR(attach_btf)) 2617 return -EINVAL; 2618 if (!btf_is_kernel(attach_btf)) { 2619 /* attaching through specifying bpf_prog's BTF 2620 * objects directly might be supported eventually 2621 */ 2622 btf_put(attach_btf); 2623 return -ENOTSUPP; 2624 } 2625 } 2626 } else if (attr->attach_btf_id) { 2627 /* fall back to vmlinux BTF, if BTF type ID is specified */ 2628 attach_btf = bpf_get_btf_vmlinux(); 2629 if (IS_ERR(attach_btf)) 2630 return PTR_ERR(attach_btf); 2631 if (!attach_btf) 2632 return -EINVAL; 2633 btf_get(attach_btf); 2634 } 2635 2636 bpf_prog_load_fixup_attach_type(attr); 2637 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 2638 attach_btf, attr->attach_btf_id, 2639 dst_prog)) { 2640 if (dst_prog) 2641 bpf_prog_put(dst_prog); 2642 if (attach_btf) 2643 btf_put(attach_btf); 2644 return -EINVAL; 2645 } 2646 2647 /* plain bpf_prog allocation */ 2648 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 2649 if (!prog) { 2650 if (dst_prog) 2651 bpf_prog_put(dst_prog); 2652 if (attach_btf) 2653 btf_put(attach_btf); 2654 return -ENOMEM; 2655 } 2656 2657 prog->expected_attach_type = attr->expected_attach_type; 2658 prog->aux->attach_btf = attach_btf; 2659 prog->aux->attach_btf_id = attr->attach_btf_id; 2660 prog->aux->dst_prog = dst_prog; 2661 prog->aux->dev_bound = !!attr->prog_ifindex; 2662 prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE; 2663 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 2664 2665 err = security_bpf_prog_alloc(prog->aux); 2666 if (err) 2667 goto free_prog; 2668 2669 prog->aux->user = get_current_user(); 2670 prog->len = attr->insn_cnt; 2671 2672 err = -EFAULT; 2673 if (copy_from_bpfptr(prog->insns, 2674 make_bpfptr(attr->insns, uattr.is_kernel), 2675 bpf_prog_insn_size(prog)) != 0) 2676 goto free_prog_sec; 2677 /* copy eBPF program license from user space */ 2678 if (strncpy_from_bpfptr(license, 2679 make_bpfptr(attr->license, uattr.is_kernel), 2680 sizeof(license) - 1) < 0) 2681 goto free_prog_sec; 2682 license[sizeof(license) - 1] = 0; 2683 2684 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 2685 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 2686 2687 prog->orig_prog = NULL; 2688 prog->jited = 0; 2689 2690 atomic64_set(&prog->aux->refcnt, 1); 2691 2692 if (bpf_prog_is_dev_bound(prog->aux)) { 2693 err = bpf_prog_dev_bound_init(prog, attr); 2694 if (err) 2695 goto free_prog_sec; 2696 } 2697 2698 if (type == BPF_PROG_TYPE_EXT && dst_prog && 2699 bpf_prog_is_dev_bound(dst_prog->aux)) { 2700 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 2701 if (err) 2702 goto free_prog_sec; 2703 } 2704 2705 /* find program type: socket_filter vs tracing_filter */ 2706 err = find_prog_type(type, prog); 2707 if (err < 0) 2708 goto free_prog_sec; 2709 2710 prog->aux->load_time = ktime_get_boottime_ns(); 2711 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 2712 sizeof(attr->prog_name)); 2713 if (err < 0) 2714 goto free_prog_sec; 2715 2716 /* run eBPF verifier */ 2717 err = bpf_check(&prog, attr, uattr, uattr_size); 2718 if (err < 0) 2719 goto free_used_maps; 2720 2721 prog = bpf_prog_select_runtime(prog, &err); 2722 if (err < 0) 2723 goto free_used_maps; 2724 2725 err = bpf_prog_alloc_id(prog); 2726 if (err) 2727 goto free_used_maps; 2728 2729 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 2730 * effectively publicly exposed. However, retrieving via 2731 * bpf_prog_get_fd_by_id() will take another reference, 2732 * therefore it cannot be gone underneath us. 2733 * 2734 * Only for the time /after/ successful bpf_prog_new_fd() 2735 * and before returning to userspace, we might just hold 2736 * one reference and any parallel close on that fd could 2737 * rip everything out. Hence, below notifications must 2738 * happen before bpf_prog_new_fd(). 2739 * 2740 * Also, any failure handling from this point onwards must 2741 * be using bpf_prog_put() given the program is exposed. 2742 */ 2743 bpf_prog_kallsyms_add(prog); 2744 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 2745 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 2746 2747 err = bpf_prog_new_fd(prog); 2748 if (err < 0) 2749 bpf_prog_put(prog); 2750 return err; 2751 2752 free_used_maps: 2753 /* In case we have subprogs, we need to wait for a grace 2754 * period before we can tear down JIT memory since symbols 2755 * are already exposed under kallsyms. 2756 */ 2757 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 2758 return err; 2759 free_prog_sec: 2760 free_uid(prog->aux->user); 2761 security_bpf_prog_free(prog->aux); 2762 free_prog: 2763 if (prog->aux->attach_btf) 2764 btf_put(prog->aux->attach_btf); 2765 bpf_prog_free(prog); 2766 return err; 2767 } 2768 2769 #define BPF_OBJ_LAST_FIELD path_fd 2770 2771 static int bpf_obj_pin(const union bpf_attr *attr) 2772 { 2773 int path_fd; 2774 2775 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 2776 return -EINVAL; 2777 2778 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 2779 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 2780 return -EINVAL; 2781 2782 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 2783 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 2784 u64_to_user_ptr(attr->pathname)); 2785 } 2786 2787 static int bpf_obj_get(const union bpf_attr *attr) 2788 { 2789 int path_fd; 2790 2791 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 2792 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 2793 return -EINVAL; 2794 2795 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 2796 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 2797 return -EINVAL; 2798 2799 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 2800 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 2801 attr->file_flags); 2802 } 2803 2804 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 2805 const struct bpf_link_ops *ops, struct bpf_prog *prog) 2806 { 2807 atomic64_set(&link->refcnt, 1); 2808 link->type = type; 2809 link->id = 0; 2810 link->ops = ops; 2811 link->prog = prog; 2812 } 2813 2814 static void bpf_link_free_id(int id) 2815 { 2816 if (!id) 2817 return; 2818 2819 spin_lock_bh(&link_idr_lock); 2820 idr_remove(&link_idr, id); 2821 spin_unlock_bh(&link_idr_lock); 2822 } 2823 2824 /* Clean up bpf_link and corresponding anon_inode file and FD. After 2825 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 2826 * anon_inode's release() call. This helper marks bpf_link as 2827 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 2828 * is not decremented, it's the responsibility of a calling code that failed 2829 * to complete bpf_link initialization. 2830 * This helper eventually calls link's dealloc callback, but does not call 2831 * link's release callback. 2832 */ 2833 void bpf_link_cleanup(struct bpf_link_primer *primer) 2834 { 2835 primer->link->prog = NULL; 2836 bpf_link_free_id(primer->id); 2837 fput(primer->file); 2838 put_unused_fd(primer->fd); 2839 } 2840 2841 void bpf_link_inc(struct bpf_link *link) 2842 { 2843 atomic64_inc(&link->refcnt); 2844 } 2845 2846 /* bpf_link_free is guaranteed to be called from process context */ 2847 static void bpf_link_free(struct bpf_link *link) 2848 { 2849 bpf_link_free_id(link->id); 2850 if (link->prog) { 2851 /* detach BPF program, clean up used resources */ 2852 link->ops->release(link); 2853 bpf_prog_put(link->prog); 2854 } 2855 /* free bpf_link and its containing memory */ 2856 link->ops->dealloc(link); 2857 } 2858 2859 static void bpf_link_put_deferred(struct work_struct *work) 2860 { 2861 struct bpf_link *link = container_of(work, struct bpf_link, work); 2862 2863 bpf_link_free(link); 2864 } 2865 2866 /* bpf_link_put might be called from atomic context. It needs to be called 2867 * from sleepable context in order to acquire sleeping locks during the process. 2868 */ 2869 void bpf_link_put(struct bpf_link *link) 2870 { 2871 if (!atomic64_dec_and_test(&link->refcnt)) 2872 return; 2873 2874 INIT_WORK(&link->work, bpf_link_put_deferred); 2875 schedule_work(&link->work); 2876 } 2877 EXPORT_SYMBOL(bpf_link_put); 2878 2879 static void bpf_link_put_direct(struct bpf_link *link) 2880 { 2881 if (!atomic64_dec_and_test(&link->refcnt)) 2882 return; 2883 bpf_link_free(link); 2884 } 2885 2886 static int bpf_link_release(struct inode *inode, struct file *filp) 2887 { 2888 struct bpf_link *link = filp->private_data; 2889 2890 bpf_link_put_direct(link); 2891 return 0; 2892 } 2893 2894 #ifdef CONFIG_PROC_FS 2895 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 2896 #define BPF_MAP_TYPE(_id, _ops) 2897 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 2898 static const char *bpf_link_type_strs[] = { 2899 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 2900 #include <linux/bpf_types.h> 2901 }; 2902 #undef BPF_PROG_TYPE 2903 #undef BPF_MAP_TYPE 2904 #undef BPF_LINK_TYPE 2905 2906 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 2907 { 2908 const struct bpf_link *link = filp->private_data; 2909 const struct bpf_prog *prog = link->prog; 2910 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2911 2912 seq_printf(m, 2913 "link_type:\t%s\n" 2914 "link_id:\t%u\n", 2915 bpf_link_type_strs[link->type], 2916 link->id); 2917 if (prog) { 2918 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2919 seq_printf(m, 2920 "prog_tag:\t%s\n" 2921 "prog_id:\t%u\n", 2922 prog_tag, 2923 prog->aux->id); 2924 } 2925 if (link->ops->show_fdinfo) 2926 link->ops->show_fdinfo(link, m); 2927 } 2928 #endif 2929 2930 static const struct file_operations bpf_link_fops = { 2931 #ifdef CONFIG_PROC_FS 2932 .show_fdinfo = bpf_link_show_fdinfo, 2933 #endif 2934 .release = bpf_link_release, 2935 .read = bpf_dummy_read, 2936 .write = bpf_dummy_write, 2937 }; 2938 2939 static int bpf_link_alloc_id(struct bpf_link *link) 2940 { 2941 int id; 2942 2943 idr_preload(GFP_KERNEL); 2944 spin_lock_bh(&link_idr_lock); 2945 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 2946 spin_unlock_bh(&link_idr_lock); 2947 idr_preload_end(); 2948 2949 return id; 2950 } 2951 2952 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 2953 * reserving unused FD and allocating ID from link_idr. This is to be paired 2954 * with bpf_link_settle() to install FD and ID and expose bpf_link to 2955 * user-space, if bpf_link is successfully attached. If not, bpf_link and 2956 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 2957 * transient state is passed around in struct bpf_link_primer. 2958 * This is preferred way to create and initialize bpf_link, especially when 2959 * there are complicated and expensive operations in between creating bpf_link 2960 * itself and attaching it to BPF hook. By using bpf_link_prime() and 2961 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 2962 * expensive (and potentially failing) roll back operations in a rare case 2963 * that file, FD, or ID can't be allocated. 2964 */ 2965 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 2966 { 2967 struct file *file; 2968 int fd, id; 2969 2970 fd = get_unused_fd_flags(O_CLOEXEC); 2971 if (fd < 0) 2972 return fd; 2973 2974 2975 id = bpf_link_alloc_id(link); 2976 if (id < 0) { 2977 put_unused_fd(fd); 2978 return id; 2979 } 2980 2981 file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC); 2982 if (IS_ERR(file)) { 2983 bpf_link_free_id(id); 2984 put_unused_fd(fd); 2985 return PTR_ERR(file); 2986 } 2987 2988 primer->link = link; 2989 primer->file = file; 2990 primer->fd = fd; 2991 primer->id = id; 2992 return 0; 2993 } 2994 2995 int bpf_link_settle(struct bpf_link_primer *primer) 2996 { 2997 /* make bpf_link fetchable by ID */ 2998 spin_lock_bh(&link_idr_lock); 2999 primer->link->id = primer->id; 3000 spin_unlock_bh(&link_idr_lock); 3001 /* make bpf_link fetchable by FD */ 3002 fd_install(primer->fd, primer->file); 3003 /* pass through installed FD */ 3004 return primer->fd; 3005 } 3006 3007 int bpf_link_new_fd(struct bpf_link *link) 3008 { 3009 return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC); 3010 } 3011 3012 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3013 { 3014 struct fd f = fdget(ufd); 3015 struct bpf_link *link; 3016 3017 if (!f.file) 3018 return ERR_PTR(-EBADF); 3019 if (f.file->f_op != &bpf_link_fops) { 3020 fdput(f); 3021 return ERR_PTR(-EINVAL); 3022 } 3023 3024 link = f.file->private_data; 3025 bpf_link_inc(link); 3026 fdput(f); 3027 3028 return link; 3029 } 3030 EXPORT_SYMBOL(bpf_link_get_from_fd); 3031 3032 static void bpf_tracing_link_release(struct bpf_link *link) 3033 { 3034 struct bpf_tracing_link *tr_link = 3035 container_of(link, struct bpf_tracing_link, link.link); 3036 3037 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3038 tr_link->trampoline)); 3039 3040 bpf_trampoline_put(tr_link->trampoline); 3041 3042 /* tgt_prog is NULL if target is a kernel function */ 3043 if (tr_link->tgt_prog) 3044 bpf_prog_put(tr_link->tgt_prog); 3045 } 3046 3047 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3048 { 3049 struct bpf_tracing_link *tr_link = 3050 container_of(link, struct bpf_tracing_link, link.link); 3051 3052 kfree(tr_link); 3053 } 3054 3055 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3056 struct seq_file *seq) 3057 { 3058 struct bpf_tracing_link *tr_link = 3059 container_of(link, struct bpf_tracing_link, link.link); 3060 u32 target_btf_id, target_obj_id; 3061 3062 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3063 &target_obj_id, &target_btf_id); 3064 seq_printf(seq, 3065 "attach_type:\t%d\n" 3066 "target_obj_id:\t%u\n" 3067 "target_btf_id:\t%u\n", 3068 tr_link->attach_type, 3069 target_obj_id, 3070 target_btf_id); 3071 } 3072 3073 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3074 struct bpf_link_info *info) 3075 { 3076 struct bpf_tracing_link *tr_link = 3077 container_of(link, struct bpf_tracing_link, link.link); 3078 3079 info->tracing.attach_type = tr_link->attach_type; 3080 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3081 &info->tracing.target_obj_id, 3082 &info->tracing.target_btf_id); 3083 3084 return 0; 3085 } 3086 3087 static const struct bpf_link_ops bpf_tracing_link_lops = { 3088 .release = bpf_tracing_link_release, 3089 .dealloc = bpf_tracing_link_dealloc, 3090 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3091 .fill_link_info = bpf_tracing_link_fill_link_info, 3092 }; 3093 3094 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3095 int tgt_prog_fd, 3096 u32 btf_id, 3097 u64 bpf_cookie) 3098 { 3099 struct bpf_link_primer link_primer; 3100 struct bpf_prog *tgt_prog = NULL; 3101 struct bpf_trampoline *tr = NULL; 3102 struct bpf_tracing_link *link; 3103 u64 key = 0; 3104 int err; 3105 3106 switch (prog->type) { 3107 case BPF_PROG_TYPE_TRACING: 3108 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3109 prog->expected_attach_type != BPF_TRACE_FEXIT && 3110 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3111 err = -EINVAL; 3112 goto out_put_prog; 3113 } 3114 break; 3115 case BPF_PROG_TYPE_EXT: 3116 if (prog->expected_attach_type != 0) { 3117 err = -EINVAL; 3118 goto out_put_prog; 3119 } 3120 break; 3121 case BPF_PROG_TYPE_LSM: 3122 if (prog->expected_attach_type != BPF_LSM_MAC) { 3123 err = -EINVAL; 3124 goto out_put_prog; 3125 } 3126 break; 3127 default: 3128 err = -EINVAL; 3129 goto out_put_prog; 3130 } 3131 3132 if (!!tgt_prog_fd != !!btf_id) { 3133 err = -EINVAL; 3134 goto out_put_prog; 3135 } 3136 3137 if (tgt_prog_fd) { 3138 /* For now we only allow new targets for BPF_PROG_TYPE_EXT */ 3139 if (prog->type != BPF_PROG_TYPE_EXT) { 3140 err = -EINVAL; 3141 goto out_put_prog; 3142 } 3143 3144 tgt_prog = bpf_prog_get(tgt_prog_fd); 3145 if (IS_ERR(tgt_prog)) { 3146 err = PTR_ERR(tgt_prog); 3147 tgt_prog = NULL; 3148 goto out_put_prog; 3149 } 3150 3151 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3152 } 3153 3154 link = kzalloc(sizeof(*link), GFP_USER); 3155 if (!link) { 3156 err = -ENOMEM; 3157 goto out_put_prog; 3158 } 3159 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3160 &bpf_tracing_link_lops, prog); 3161 link->attach_type = prog->expected_attach_type; 3162 link->link.cookie = bpf_cookie; 3163 3164 mutex_lock(&prog->aux->dst_mutex); 3165 3166 /* There are a few possible cases here: 3167 * 3168 * - if prog->aux->dst_trampoline is set, the program was just loaded 3169 * and not yet attached to anything, so we can use the values stored 3170 * in prog->aux 3171 * 3172 * - if prog->aux->dst_trampoline is NULL, the program has already been 3173 * attached to a target and its initial target was cleared (below) 3174 * 3175 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3176 * target_btf_id using the link_create API. 3177 * 3178 * - if tgt_prog == NULL when this function was called using the old 3179 * raw_tracepoint_open API, and we need a target from prog->aux 3180 * 3181 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3182 * was detached and is going for re-attachment. 3183 */ 3184 if (!prog->aux->dst_trampoline && !tgt_prog) { 3185 /* 3186 * Allow re-attach for TRACING and LSM programs. If it's 3187 * currently linked, bpf_trampoline_link_prog will fail. 3188 * EXT programs need to specify tgt_prog_fd, so they 3189 * re-attach in separate code path. 3190 */ 3191 if (prog->type != BPF_PROG_TYPE_TRACING && 3192 prog->type != BPF_PROG_TYPE_LSM) { 3193 err = -EINVAL; 3194 goto out_unlock; 3195 } 3196 btf_id = prog->aux->attach_btf_id; 3197 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3198 } 3199 3200 if (!prog->aux->dst_trampoline || 3201 (key && key != prog->aux->dst_trampoline->key)) { 3202 /* If there is no saved target, or the specified target is 3203 * different from the destination specified at load time, we 3204 * need a new trampoline and a check for compatibility 3205 */ 3206 struct bpf_attach_target_info tgt_info = {}; 3207 3208 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3209 &tgt_info); 3210 if (err) 3211 goto out_unlock; 3212 3213 if (tgt_info.tgt_mod) { 3214 module_put(prog->aux->mod); 3215 prog->aux->mod = tgt_info.tgt_mod; 3216 } 3217 3218 tr = bpf_trampoline_get(key, &tgt_info); 3219 if (!tr) { 3220 err = -ENOMEM; 3221 goto out_unlock; 3222 } 3223 } else { 3224 /* The caller didn't specify a target, or the target was the 3225 * same as the destination supplied during program load. This 3226 * means we can reuse the trampoline and reference from program 3227 * load time, and there is no need to allocate a new one. This 3228 * can only happen once for any program, as the saved values in 3229 * prog->aux are cleared below. 3230 */ 3231 tr = prog->aux->dst_trampoline; 3232 tgt_prog = prog->aux->dst_prog; 3233 } 3234 3235 err = bpf_link_prime(&link->link.link, &link_primer); 3236 if (err) 3237 goto out_unlock; 3238 3239 err = bpf_trampoline_link_prog(&link->link, tr); 3240 if (err) { 3241 bpf_link_cleanup(&link_primer); 3242 link = NULL; 3243 goto out_unlock; 3244 } 3245 3246 link->tgt_prog = tgt_prog; 3247 link->trampoline = tr; 3248 3249 /* Always clear the trampoline and target prog from prog->aux to make 3250 * sure the original attach destination is not kept alive after a 3251 * program is (re-)attached to another target. 3252 */ 3253 if (prog->aux->dst_prog && 3254 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3255 /* got extra prog ref from syscall, or attaching to different prog */ 3256 bpf_prog_put(prog->aux->dst_prog); 3257 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3258 /* we allocated a new trampoline, so free the old one */ 3259 bpf_trampoline_put(prog->aux->dst_trampoline); 3260 3261 prog->aux->dst_prog = NULL; 3262 prog->aux->dst_trampoline = NULL; 3263 mutex_unlock(&prog->aux->dst_mutex); 3264 3265 return bpf_link_settle(&link_primer); 3266 out_unlock: 3267 if (tr && tr != prog->aux->dst_trampoline) 3268 bpf_trampoline_put(tr); 3269 mutex_unlock(&prog->aux->dst_mutex); 3270 kfree(link); 3271 out_put_prog: 3272 if (tgt_prog_fd && tgt_prog) 3273 bpf_prog_put(tgt_prog); 3274 return err; 3275 } 3276 3277 struct bpf_raw_tp_link { 3278 struct bpf_link link; 3279 struct bpf_raw_event_map *btp; 3280 }; 3281 3282 static void bpf_raw_tp_link_release(struct bpf_link *link) 3283 { 3284 struct bpf_raw_tp_link *raw_tp = 3285 container_of(link, struct bpf_raw_tp_link, link); 3286 3287 bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog); 3288 bpf_put_raw_tracepoint(raw_tp->btp); 3289 } 3290 3291 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3292 { 3293 struct bpf_raw_tp_link *raw_tp = 3294 container_of(link, struct bpf_raw_tp_link, link); 3295 3296 kfree(raw_tp); 3297 } 3298 3299 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3300 struct seq_file *seq) 3301 { 3302 struct bpf_raw_tp_link *raw_tp_link = 3303 container_of(link, struct bpf_raw_tp_link, link); 3304 3305 seq_printf(seq, 3306 "tp_name:\t%s\n", 3307 raw_tp_link->btp->tp->name); 3308 } 3309 3310 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3311 u32 len) 3312 { 3313 if (ulen >= len + 1) { 3314 if (copy_to_user(ubuf, buf, len + 1)) 3315 return -EFAULT; 3316 } else { 3317 char zero = '\0'; 3318 3319 if (copy_to_user(ubuf, buf, ulen - 1)) 3320 return -EFAULT; 3321 if (put_user(zero, ubuf + ulen - 1)) 3322 return -EFAULT; 3323 return -ENOSPC; 3324 } 3325 3326 return 0; 3327 } 3328 3329 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3330 struct bpf_link_info *info) 3331 { 3332 struct bpf_raw_tp_link *raw_tp_link = 3333 container_of(link, struct bpf_raw_tp_link, link); 3334 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3335 const char *tp_name = raw_tp_link->btp->tp->name; 3336 u32 ulen = info->raw_tracepoint.tp_name_len; 3337 size_t tp_len = strlen(tp_name); 3338 3339 if (!ulen ^ !ubuf) 3340 return -EINVAL; 3341 3342 info->raw_tracepoint.tp_name_len = tp_len + 1; 3343 3344 if (!ubuf) 3345 return 0; 3346 3347 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3348 } 3349 3350 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3351 .release = bpf_raw_tp_link_release, 3352 .dealloc = bpf_raw_tp_link_dealloc, 3353 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3354 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3355 }; 3356 3357 #ifdef CONFIG_PERF_EVENTS 3358 struct bpf_perf_link { 3359 struct bpf_link link; 3360 struct file *perf_file; 3361 }; 3362 3363 static void bpf_perf_link_release(struct bpf_link *link) 3364 { 3365 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3366 struct perf_event *event = perf_link->perf_file->private_data; 3367 3368 perf_event_free_bpf_prog(event); 3369 fput(perf_link->perf_file); 3370 } 3371 3372 static void bpf_perf_link_dealloc(struct bpf_link *link) 3373 { 3374 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3375 3376 kfree(perf_link); 3377 } 3378 3379 static int bpf_perf_link_fill_common(const struct perf_event *event, 3380 char __user *uname, u32 ulen, 3381 u64 *probe_offset, u64 *probe_addr, 3382 u32 *fd_type, unsigned long *missed) 3383 { 3384 const char *buf; 3385 u32 prog_id; 3386 size_t len; 3387 int err; 3388 3389 if (!ulen ^ !uname) 3390 return -EINVAL; 3391 3392 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3393 probe_offset, probe_addr, missed); 3394 if (err) 3395 return err; 3396 if (!uname) 3397 return 0; 3398 if (buf) { 3399 len = strlen(buf); 3400 err = bpf_copy_to_user(uname, buf, ulen, len); 3401 if (err) 3402 return err; 3403 } else { 3404 char zero = '\0'; 3405 3406 if (put_user(zero, uname)) 3407 return -EFAULT; 3408 } 3409 return 0; 3410 } 3411 3412 #ifdef CONFIG_KPROBE_EVENTS 3413 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 3414 struct bpf_link_info *info) 3415 { 3416 unsigned long missed; 3417 char __user *uname; 3418 u64 addr, offset; 3419 u32 ulen, type; 3420 int err; 3421 3422 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 3423 ulen = info->perf_event.kprobe.name_len; 3424 err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, 3425 &type, &missed); 3426 if (err) 3427 return err; 3428 if (type == BPF_FD_TYPE_KRETPROBE) 3429 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 3430 else 3431 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 3432 3433 info->perf_event.kprobe.offset = offset; 3434 info->perf_event.kprobe.missed = missed; 3435 if (!kallsyms_show_value(current_cred())) 3436 addr = 0; 3437 info->perf_event.kprobe.addr = addr; 3438 return 0; 3439 } 3440 #endif 3441 3442 #ifdef CONFIG_UPROBE_EVENTS 3443 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 3444 struct bpf_link_info *info) 3445 { 3446 char __user *uname; 3447 u64 addr, offset; 3448 u32 ulen, type; 3449 int err; 3450 3451 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 3452 ulen = info->perf_event.uprobe.name_len; 3453 err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, 3454 &type, NULL); 3455 if (err) 3456 return err; 3457 3458 if (type == BPF_FD_TYPE_URETPROBE) 3459 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 3460 else 3461 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 3462 info->perf_event.uprobe.offset = offset; 3463 return 0; 3464 } 3465 #endif 3466 3467 static int bpf_perf_link_fill_probe(const struct perf_event *event, 3468 struct bpf_link_info *info) 3469 { 3470 #ifdef CONFIG_KPROBE_EVENTS 3471 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 3472 return bpf_perf_link_fill_kprobe(event, info); 3473 #endif 3474 #ifdef CONFIG_UPROBE_EVENTS 3475 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 3476 return bpf_perf_link_fill_uprobe(event, info); 3477 #endif 3478 return -EOPNOTSUPP; 3479 } 3480 3481 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 3482 struct bpf_link_info *info) 3483 { 3484 char __user *uname; 3485 u32 ulen; 3486 3487 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 3488 ulen = info->perf_event.tracepoint.name_len; 3489 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 3490 return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL); 3491 } 3492 3493 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 3494 struct bpf_link_info *info) 3495 { 3496 info->perf_event.event.type = event->attr.type; 3497 info->perf_event.event.config = event->attr.config; 3498 info->perf_event.type = BPF_PERF_EVENT_EVENT; 3499 return 0; 3500 } 3501 3502 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 3503 struct bpf_link_info *info) 3504 { 3505 struct bpf_perf_link *perf_link; 3506 const struct perf_event *event; 3507 3508 perf_link = container_of(link, struct bpf_perf_link, link); 3509 event = perf_get_event(perf_link->perf_file); 3510 if (IS_ERR(event)) 3511 return PTR_ERR(event); 3512 3513 switch (event->prog->type) { 3514 case BPF_PROG_TYPE_PERF_EVENT: 3515 return bpf_perf_link_fill_perf_event(event, info); 3516 case BPF_PROG_TYPE_TRACEPOINT: 3517 return bpf_perf_link_fill_tracepoint(event, info); 3518 case BPF_PROG_TYPE_KPROBE: 3519 return bpf_perf_link_fill_probe(event, info); 3520 default: 3521 return -EOPNOTSUPP; 3522 } 3523 } 3524 3525 static const struct bpf_link_ops bpf_perf_link_lops = { 3526 .release = bpf_perf_link_release, 3527 .dealloc = bpf_perf_link_dealloc, 3528 .fill_link_info = bpf_perf_link_fill_link_info, 3529 }; 3530 3531 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3532 { 3533 struct bpf_link_primer link_primer; 3534 struct bpf_perf_link *link; 3535 struct perf_event *event; 3536 struct file *perf_file; 3537 int err; 3538 3539 if (attr->link_create.flags) 3540 return -EINVAL; 3541 3542 perf_file = perf_event_get(attr->link_create.target_fd); 3543 if (IS_ERR(perf_file)) 3544 return PTR_ERR(perf_file); 3545 3546 link = kzalloc(sizeof(*link), GFP_USER); 3547 if (!link) { 3548 err = -ENOMEM; 3549 goto out_put_file; 3550 } 3551 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog); 3552 link->perf_file = perf_file; 3553 3554 err = bpf_link_prime(&link->link, &link_primer); 3555 if (err) { 3556 kfree(link); 3557 goto out_put_file; 3558 } 3559 3560 event = perf_file->private_data; 3561 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 3562 if (err) { 3563 bpf_link_cleanup(&link_primer); 3564 goto out_put_file; 3565 } 3566 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 3567 bpf_prog_inc(prog); 3568 3569 return bpf_link_settle(&link_primer); 3570 3571 out_put_file: 3572 fput(perf_file); 3573 return err; 3574 } 3575 #else 3576 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3577 { 3578 return -EOPNOTSUPP; 3579 } 3580 #endif /* CONFIG_PERF_EVENTS */ 3581 3582 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 3583 const char __user *user_tp_name) 3584 { 3585 struct bpf_link_primer link_primer; 3586 struct bpf_raw_tp_link *link; 3587 struct bpf_raw_event_map *btp; 3588 const char *tp_name; 3589 char buf[128]; 3590 int err; 3591 3592 switch (prog->type) { 3593 case BPF_PROG_TYPE_TRACING: 3594 case BPF_PROG_TYPE_EXT: 3595 case BPF_PROG_TYPE_LSM: 3596 if (user_tp_name) 3597 /* The attach point for this category of programs 3598 * should be specified via btf_id during program load. 3599 */ 3600 return -EINVAL; 3601 if (prog->type == BPF_PROG_TYPE_TRACING && 3602 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 3603 tp_name = prog->aux->attach_func_name; 3604 break; 3605 } 3606 return bpf_tracing_prog_attach(prog, 0, 0, 0); 3607 case BPF_PROG_TYPE_RAW_TRACEPOINT: 3608 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 3609 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 3610 return -EFAULT; 3611 buf[sizeof(buf) - 1] = 0; 3612 tp_name = buf; 3613 break; 3614 default: 3615 return -EINVAL; 3616 } 3617 3618 btp = bpf_get_raw_tracepoint(tp_name); 3619 if (!btp) 3620 return -ENOENT; 3621 3622 link = kzalloc(sizeof(*link), GFP_USER); 3623 if (!link) { 3624 err = -ENOMEM; 3625 goto out_put_btp; 3626 } 3627 bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 3628 &bpf_raw_tp_link_lops, prog); 3629 link->btp = btp; 3630 3631 err = bpf_link_prime(&link->link, &link_primer); 3632 if (err) { 3633 kfree(link); 3634 goto out_put_btp; 3635 } 3636 3637 err = bpf_probe_register(link->btp, prog); 3638 if (err) { 3639 bpf_link_cleanup(&link_primer); 3640 goto out_put_btp; 3641 } 3642 3643 return bpf_link_settle(&link_primer); 3644 3645 out_put_btp: 3646 bpf_put_raw_tracepoint(btp); 3647 return err; 3648 } 3649 3650 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd 3651 3652 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 3653 { 3654 struct bpf_prog *prog; 3655 int fd; 3656 3657 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 3658 return -EINVAL; 3659 3660 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 3661 if (IS_ERR(prog)) 3662 return PTR_ERR(prog); 3663 3664 fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name)); 3665 if (fd < 0) 3666 bpf_prog_put(prog); 3667 return fd; 3668 } 3669 3670 static enum bpf_prog_type 3671 attach_type_to_prog_type(enum bpf_attach_type attach_type) 3672 { 3673 switch (attach_type) { 3674 case BPF_CGROUP_INET_INGRESS: 3675 case BPF_CGROUP_INET_EGRESS: 3676 return BPF_PROG_TYPE_CGROUP_SKB; 3677 case BPF_CGROUP_INET_SOCK_CREATE: 3678 case BPF_CGROUP_INET_SOCK_RELEASE: 3679 case BPF_CGROUP_INET4_POST_BIND: 3680 case BPF_CGROUP_INET6_POST_BIND: 3681 return BPF_PROG_TYPE_CGROUP_SOCK; 3682 case BPF_CGROUP_INET4_BIND: 3683 case BPF_CGROUP_INET6_BIND: 3684 case BPF_CGROUP_INET4_CONNECT: 3685 case BPF_CGROUP_INET6_CONNECT: 3686 case BPF_CGROUP_UNIX_CONNECT: 3687 case BPF_CGROUP_INET4_GETPEERNAME: 3688 case BPF_CGROUP_INET6_GETPEERNAME: 3689 case BPF_CGROUP_UNIX_GETPEERNAME: 3690 case BPF_CGROUP_INET4_GETSOCKNAME: 3691 case BPF_CGROUP_INET6_GETSOCKNAME: 3692 case BPF_CGROUP_UNIX_GETSOCKNAME: 3693 case BPF_CGROUP_UDP4_SENDMSG: 3694 case BPF_CGROUP_UDP6_SENDMSG: 3695 case BPF_CGROUP_UNIX_SENDMSG: 3696 case BPF_CGROUP_UDP4_RECVMSG: 3697 case BPF_CGROUP_UDP6_RECVMSG: 3698 case BPF_CGROUP_UNIX_RECVMSG: 3699 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 3700 case BPF_CGROUP_SOCK_OPS: 3701 return BPF_PROG_TYPE_SOCK_OPS; 3702 case BPF_CGROUP_DEVICE: 3703 return BPF_PROG_TYPE_CGROUP_DEVICE; 3704 case BPF_SK_MSG_VERDICT: 3705 return BPF_PROG_TYPE_SK_MSG; 3706 case BPF_SK_SKB_STREAM_PARSER: 3707 case BPF_SK_SKB_STREAM_VERDICT: 3708 case BPF_SK_SKB_VERDICT: 3709 return BPF_PROG_TYPE_SK_SKB; 3710 case BPF_LIRC_MODE2: 3711 return BPF_PROG_TYPE_LIRC_MODE2; 3712 case BPF_FLOW_DISSECTOR: 3713 return BPF_PROG_TYPE_FLOW_DISSECTOR; 3714 case BPF_CGROUP_SYSCTL: 3715 return BPF_PROG_TYPE_CGROUP_SYSCTL; 3716 case BPF_CGROUP_GETSOCKOPT: 3717 case BPF_CGROUP_SETSOCKOPT: 3718 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 3719 case BPF_TRACE_ITER: 3720 case BPF_TRACE_RAW_TP: 3721 case BPF_TRACE_FENTRY: 3722 case BPF_TRACE_FEXIT: 3723 case BPF_MODIFY_RETURN: 3724 return BPF_PROG_TYPE_TRACING; 3725 case BPF_LSM_MAC: 3726 return BPF_PROG_TYPE_LSM; 3727 case BPF_SK_LOOKUP: 3728 return BPF_PROG_TYPE_SK_LOOKUP; 3729 case BPF_XDP: 3730 return BPF_PROG_TYPE_XDP; 3731 case BPF_LSM_CGROUP: 3732 return BPF_PROG_TYPE_LSM; 3733 case BPF_TCX_INGRESS: 3734 case BPF_TCX_EGRESS: 3735 return BPF_PROG_TYPE_SCHED_CLS; 3736 default: 3737 return BPF_PROG_TYPE_UNSPEC; 3738 } 3739 } 3740 3741 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 3742 enum bpf_attach_type attach_type) 3743 { 3744 enum bpf_prog_type ptype; 3745 3746 switch (prog->type) { 3747 case BPF_PROG_TYPE_CGROUP_SOCK: 3748 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3749 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3750 case BPF_PROG_TYPE_SK_LOOKUP: 3751 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 3752 case BPF_PROG_TYPE_CGROUP_SKB: 3753 if (!capable(CAP_NET_ADMIN)) 3754 /* cg-skb progs can be loaded by unpriv user. 3755 * check permissions at attach time. 3756 */ 3757 return -EPERM; 3758 return prog->enforce_expected_attach_type && 3759 prog->expected_attach_type != attach_type ? 3760 -EINVAL : 0; 3761 case BPF_PROG_TYPE_EXT: 3762 return 0; 3763 case BPF_PROG_TYPE_NETFILTER: 3764 if (attach_type != BPF_NETFILTER) 3765 return -EINVAL; 3766 return 0; 3767 case BPF_PROG_TYPE_PERF_EVENT: 3768 case BPF_PROG_TYPE_TRACEPOINT: 3769 if (attach_type != BPF_PERF_EVENT) 3770 return -EINVAL; 3771 return 0; 3772 case BPF_PROG_TYPE_KPROBE: 3773 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 3774 attach_type != BPF_TRACE_KPROBE_MULTI) 3775 return -EINVAL; 3776 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 3777 attach_type != BPF_TRACE_UPROBE_MULTI) 3778 return -EINVAL; 3779 if (attach_type != BPF_PERF_EVENT && 3780 attach_type != BPF_TRACE_KPROBE_MULTI && 3781 attach_type != BPF_TRACE_UPROBE_MULTI) 3782 return -EINVAL; 3783 return 0; 3784 case BPF_PROG_TYPE_SCHED_CLS: 3785 if (attach_type != BPF_TCX_INGRESS && 3786 attach_type != BPF_TCX_EGRESS) 3787 return -EINVAL; 3788 return 0; 3789 default: 3790 ptype = attach_type_to_prog_type(attach_type); 3791 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 3792 return -EINVAL; 3793 return 0; 3794 } 3795 } 3796 3797 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 3798 3799 #define BPF_F_ATTACH_MASK_BASE \ 3800 (BPF_F_ALLOW_OVERRIDE | \ 3801 BPF_F_ALLOW_MULTI | \ 3802 BPF_F_REPLACE) 3803 3804 #define BPF_F_ATTACH_MASK_MPROG \ 3805 (BPF_F_REPLACE | \ 3806 BPF_F_BEFORE | \ 3807 BPF_F_AFTER | \ 3808 BPF_F_ID | \ 3809 BPF_F_LINK) 3810 3811 static int bpf_prog_attach(const union bpf_attr *attr) 3812 { 3813 enum bpf_prog_type ptype; 3814 struct bpf_prog *prog; 3815 u32 mask; 3816 int ret; 3817 3818 if (CHECK_ATTR(BPF_PROG_ATTACH)) 3819 return -EINVAL; 3820 3821 ptype = attach_type_to_prog_type(attr->attach_type); 3822 if (ptype == BPF_PROG_TYPE_UNSPEC) 3823 return -EINVAL; 3824 mask = bpf_mprog_supported(ptype) ? 3825 BPF_F_ATTACH_MASK_MPROG : BPF_F_ATTACH_MASK_BASE; 3826 if (attr->attach_flags & ~mask) 3827 return -EINVAL; 3828 3829 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 3830 if (IS_ERR(prog)) 3831 return PTR_ERR(prog); 3832 3833 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 3834 bpf_prog_put(prog); 3835 return -EINVAL; 3836 } 3837 3838 switch (ptype) { 3839 case BPF_PROG_TYPE_SK_SKB: 3840 case BPF_PROG_TYPE_SK_MSG: 3841 ret = sock_map_get_from_fd(attr, prog); 3842 break; 3843 case BPF_PROG_TYPE_LIRC_MODE2: 3844 ret = lirc_prog_attach(attr, prog); 3845 break; 3846 case BPF_PROG_TYPE_FLOW_DISSECTOR: 3847 ret = netns_bpf_prog_attach(attr, prog); 3848 break; 3849 case BPF_PROG_TYPE_CGROUP_DEVICE: 3850 case BPF_PROG_TYPE_CGROUP_SKB: 3851 case BPF_PROG_TYPE_CGROUP_SOCK: 3852 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3853 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3854 case BPF_PROG_TYPE_CGROUP_SYSCTL: 3855 case BPF_PROG_TYPE_SOCK_OPS: 3856 case BPF_PROG_TYPE_LSM: 3857 if (ptype == BPF_PROG_TYPE_LSM && 3858 prog->expected_attach_type != BPF_LSM_CGROUP) 3859 ret = -EINVAL; 3860 else 3861 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 3862 break; 3863 case BPF_PROG_TYPE_SCHED_CLS: 3864 ret = tcx_prog_attach(attr, prog); 3865 break; 3866 default: 3867 ret = -EINVAL; 3868 } 3869 3870 if (ret) 3871 bpf_prog_put(prog); 3872 return ret; 3873 } 3874 3875 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 3876 3877 static int bpf_prog_detach(const union bpf_attr *attr) 3878 { 3879 struct bpf_prog *prog = NULL; 3880 enum bpf_prog_type ptype; 3881 int ret; 3882 3883 if (CHECK_ATTR(BPF_PROG_DETACH)) 3884 return -EINVAL; 3885 3886 ptype = attach_type_to_prog_type(attr->attach_type); 3887 if (bpf_mprog_supported(ptype)) { 3888 if (ptype == BPF_PROG_TYPE_UNSPEC) 3889 return -EINVAL; 3890 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 3891 return -EINVAL; 3892 if (attr->attach_bpf_fd) { 3893 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 3894 if (IS_ERR(prog)) 3895 return PTR_ERR(prog); 3896 } 3897 } 3898 3899 switch (ptype) { 3900 case BPF_PROG_TYPE_SK_MSG: 3901 case BPF_PROG_TYPE_SK_SKB: 3902 ret = sock_map_prog_detach(attr, ptype); 3903 break; 3904 case BPF_PROG_TYPE_LIRC_MODE2: 3905 ret = lirc_prog_detach(attr); 3906 break; 3907 case BPF_PROG_TYPE_FLOW_DISSECTOR: 3908 ret = netns_bpf_prog_detach(attr, ptype); 3909 break; 3910 case BPF_PROG_TYPE_CGROUP_DEVICE: 3911 case BPF_PROG_TYPE_CGROUP_SKB: 3912 case BPF_PROG_TYPE_CGROUP_SOCK: 3913 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3914 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3915 case BPF_PROG_TYPE_CGROUP_SYSCTL: 3916 case BPF_PROG_TYPE_SOCK_OPS: 3917 case BPF_PROG_TYPE_LSM: 3918 ret = cgroup_bpf_prog_detach(attr, ptype); 3919 break; 3920 case BPF_PROG_TYPE_SCHED_CLS: 3921 ret = tcx_prog_detach(attr, prog); 3922 break; 3923 default: 3924 ret = -EINVAL; 3925 } 3926 3927 if (prog) 3928 bpf_prog_put(prog); 3929 return ret; 3930 } 3931 3932 #define BPF_PROG_QUERY_LAST_FIELD query.link_attach_flags 3933 3934 static int bpf_prog_query(const union bpf_attr *attr, 3935 union bpf_attr __user *uattr) 3936 { 3937 if (!capable(CAP_NET_ADMIN)) 3938 return -EPERM; 3939 if (CHECK_ATTR(BPF_PROG_QUERY)) 3940 return -EINVAL; 3941 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 3942 return -EINVAL; 3943 3944 switch (attr->query.attach_type) { 3945 case BPF_CGROUP_INET_INGRESS: 3946 case BPF_CGROUP_INET_EGRESS: 3947 case BPF_CGROUP_INET_SOCK_CREATE: 3948 case BPF_CGROUP_INET_SOCK_RELEASE: 3949 case BPF_CGROUP_INET4_BIND: 3950 case BPF_CGROUP_INET6_BIND: 3951 case BPF_CGROUP_INET4_POST_BIND: 3952 case BPF_CGROUP_INET6_POST_BIND: 3953 case BPF_CGROUP_INET4_CONNECT: 3954 case BPF_CGROUP_INET6_CONNECT: 3955 case BPF_CGROUP_UNIX_CONNECT: 3956 case BPF_CGROUP_INET4_GETPEERNAME: 3957 case BPF_CGROUP_INET6_GETPEERNAME: 3958 case BPF_CGROUP_UNIX_GETPEERNAME: 3959 case BPF_CGROUP_INET4_GETSOCKNAME: 3960 case BPF_CGROUP_INET6_GETSOCKNAME: 3961 case BPF_CGROUP_UNIX_GETSOCKNAME: 3962 case BPF_CGROUP_UDP4_SENDMSG: 3963 case BPF_CGROUP_UDP6_SENDMSG: 3964 case BPF_CGROUP_UNIX_SENDMSG: 3965 case BPF_CGROUP_UDP4_RECVMSG: 3966 case BPF_CGROUP_UDP6_RECVMSG: 3967 case BPF_CGROUP_UNIX_RECVMSG: 3968 case BPF_CGROUP_SOCK_OPS: 3969 case BPF_CGROUP_DEVICE: 3970 case BPF_CGROUP_SYSCTL: 3971 case BPF_CGROUP_GETSOCKOPT: 3972 case BPF_CGROUP_SETSOCKOPT: 3973 case BPF_LSM_CGROUP: 3974 return cgroup_bpf_prog_query(attr, uattr); 3975 case BPF_LIRC_MODE2: 3976 return lirc_prog_query(attr, uattr); 3977 case BPF_FLOW_DISSECTOR: 3978 case BPF_SK_LOOKUP: 3979 return netns_bpf_prog_query(attr, uattr); 3980 case BPF_SK_SKB_STREAM_PARSER: 3981 case BPF_SK_SKB_STREAM_VERDICT: 3982 case BPF_SK_MSG_VERDICT: 3983 case BPF_SK_SKB_VERDICT: 3984 return sock_map_bpf_prog_query(attr, uattr); 3985 case BPF_TCX_INGRESS: 3986 case BPF_TCX_EGRESS: 3987 return tcx_prog_query(attr, uattr); 3988 default: 3989 return -EINVAL; 3990 } 3991 } 3992 3993 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 3994 3995 static int bpf_prog_test_run(const union bpf_attr *attr, 3996 union bpf_attr __user *uattr) 3997 { 3998 struct bpf_prog *prog; 3999 int ret = -ENOTSUPP; 4000 4001 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4002 return -EINVAL; 4003 4004 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4005 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4006 return -EINVAL; 4007 4008 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4009 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4010 return -EINVAL; 4011 4012 prog = bpf_prog_get(attr->test.prog_fd); 4013 if (IS_ERR(prog)) 4014 return PTR_ERR(prog); 4015 4016 if (prog->aux->ops->test_run) 4017 ret = prog->aux->ops->test_run(prog, attr, uattr); 4018 4019 bpf_prog_put(prog); 4020 return ret; 4021 } 4022 4023 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4024 4025 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4026 union bpf_attr __user *uattr, 4027 struct idr *idr, 4028 spinlock_t *lock) 4029 { 4030 u32 next_id = attr->start_id; 4031 int err = 0; 4032 4033 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4034 return -EINVAL; 4035 4036 if (!capable(CAP_SYS_ADMIN)) 4037 return -EPERM; 4038 4039 next_id++; 4040 spin_lock_bh(lock); 4041 if (!idr_get_next(idr, &next_id)) 4042 err = -ENOENT; 4043 spin_unlock_bh(lock); 4044 4045 if (!err) 4046 err = put_user(next_id, &uattr->next_id); 4047 4048 return err; 4049 } 4050 4051 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4052 { 4053 struct bpf_map *map; 4054 4055 spin_lock_bh(&map_idr_lock); 4056 again: 4057 map = idr_get_next(&map_idr, id); 4058 if (map) { 4059 map = __bpf_map_inc_not_zero(map, false); 4060 if (IS_ERR(map)) { 4061 (*id)++; 4062 goto again; 4063 } 4064 } 4065 spin_unlock_bh(&map_idr_lock); 4066 4067 return map; 4068 } 4069 4070 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4071 { 4072 struct bpf_prog *prog; 4073 4074 spin_lock_bh(&prog_idr_lock); 4075 again: 4076 prog = idr_get_next(&prog_idr, id); 4077 if (prog) { 4078 prog = bpf_prog_inc_not_zero(prog); 4079 if (IS_ERR(prog)) { 4080 (*id)++; 4081 goto again; 4082 } 4083 } 4084 spin_unlock_bh(&prog_idr_lock); 4085 4086 return prog; 4087 } 4088 4089 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4090 4091 struct bpf_prog *bpf_prog_by_id(u32 id) 4092 { 4093 struct bpf_prog *prog; 4094 4095 if (!id) 4096 return ERR_PTR(-ENOENT); 4097 4098 spin_lock_bh(&prog_idr_lock); 4099 prog = idr_find(&prog_idr, id); 4100 if (prog) 4101 prog = bpf_prog_inc_not_zero(prog); 4102 else 4103 prog = ERR_PTR(-ENOENT); 4104 spin_unlock_bh(&prog_idr_lock); 4105 return prog; 4106 } 4107 4108 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4109 { 4110 struct bpf_prog *prog; 4111 u32 id = attr->prog_id; 4112 int fd; 4113 4114 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4115 return -EINVAL; 4116 4117 if (!capable(CAP_SYS_ADMIN)) 4118 return -EPERM; 4119 4120 prog = bpf_prog_by_id(id); 4121 if (IS_ERR(prog)) 4122 return PTR_ERR(prog); 4123 4124 fd = bpf_prog_new_fd(prog); 4125 if (fd < 0) 4126 bpf_prog_put(prog); 4127 4128 return fd; 4129 } 4130 4131 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4132 4133 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4134 { 4135 struct bpf_map *map; 4136 u32 id = attr->map_id; 4137 int f_flags; 4138 int fd; 4139 4140 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4141 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4142 return -EINVAL; 4143 4144 if (!capable(CAP_SYS_ADMIN)) 4145 return -EPERM; 4146 4147 f_flags = bpf_get_file_flag(attr->open_flags); 4148 if (f_flags < 0) 4149 return f_flags; 4150 4151 spin_lock_bh(&map_idr_lock); 4152 map = idr_find(&map_idr, id); 4153 if (map) 4154 map = __bpf_map_inc_not_zero(map, true); 4155 else 4156 map = ERR_PTR(-ENOENT); 4157 spin_unlock_bh(&map_idr_lock); 4158 4159 if (IS_ERR(map)) 4160 return PTR_ERR(map); 4161 4162 fd = bpf_map_new_fd(map, f_flags); 4163 if (fd < 0) 4164 bpf_map_put_with_uref(map); 4165 4166 return fd; 4167 } 4168 4169 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4170 unsigned long addr, u32 *off, 4171 u32 *type) 4172 { 4173 const struct bpf_map *map; 4174 int i; 4175 4176 mutex_lock(&prog->aux->used_maps_mutex); 4177 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4178 map = prog->aux->used_maps[i]; 4179 if (map == (void *)addr) { 4180 *type = BPF_PSEUDO_MAP_FD; 4181 goto out; 4182 } 4183 if (!map->ops->map_direct_value_meta) 4184 continue; 4185 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4186 *type = BPF_PSEUDO_MAP_VALUE; 4187 goto out; 4188 } 4189 } 4190 map = NULL; 4191 4192 out: 4193 mutex_unlock(&prog->aux->used_maps_mutex); 4194 return map; 4195 } 4196 4197 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 4198 const struct cred *f_cred) 4199 { 4200 const struct bpf_map *map; 4201 struct bpf_insn *insns; 4202 u32 off, type; 4203 u64 imm; 4204 u8 code; 4205 int i; 4206 4207 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 4208 GFP_USER); 4209 if (!insns) 4210 return insns; 4211 4212 for (i = 0; i < prog->len; i++) { 4213 code = insns[i].code; 4214 4215 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 4216 insns[i].code = BPF_JMP | BPF_CALL; 4217 insns[i].imm = BPF_FUNC_tail_call; 4218 /* fall-through */ 4219 } 4220 if (code == (BPF_JMP | BPF_CALL) || 4221 code == (BPF_JMP | BPF_CALL_ARGS)) { 4222 if (code == (BPF_JMP | BPF_CALL_ARGS)) 4223 insns[i].code = BPF_JMP | BPF_CALL; 4224 if (!bpf_dump_raw_ok(f_cred)) 4225 insns[i].imm = 0; 4226 continue; 4227 } 4228 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 4229 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 4230 continue; 4231 } 4232 4233 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 4234 continue; 4235 4236 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 4237 map = bpf_map_from_imm(prog, imm, &off, &type); 4238 if (map) { 4239 insns[i].src_reg = type; 4240 insns[i].imm = map->id; 4241 insns[i + 1].imm = off; 4242 continue; 4243 } 4244 } 4245 4246 return insns; 4247 } 4248 4249 static int set_info_rec_size(struct bpf_prog_info *info) 4250 { 4251 /* 4252 * Ensure info.*_rec_size is the same as kernel expected size 4253 * 4254 * or 4255 * 4256 * Only allow zero *_rec_size if both _rec_size and _cnt are 4257 * zero. In this case, the kernel will set the expected 4258 * _rec_size back to the info. 4259 */ 4260 4261 if ((info->nr_func_info || info->func_info_rec_size) && 4262 info->func_info_rec_size != sizeof(struct bpf_func_info)) 4263 return -EINVAL; 4264 4265 if ((info->nr_line_info || info->line_info_rec_size) && 4266 info->line_info_rec_size != sizeof(struct bpf_line_info)) 4267 return -EINVAL; 4268 4269 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 4270 info->jited_line_info_rec_size != sizeof(__u64)) 4271 return -EINVAL; 4272 4273 info->func_info_rec_size = sizeof(struct bpf_func_info); 4274 info->line_info_rec_size = sizeof(struct bpf_line_info); 4275 info->jited_line_info_rec_size = sizeof(__u64); 4276 4277 return 0; 4278 } 4279 4280 static int bpf_prog_get_info_by_fd(struct file *file, 4281 struct bpf_prog *prog, 4282 const union bpf_attr *attr, 4283 union bpf_attr __user *uattr) 4284 { 4285 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4286 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 4287 struct bpf_prog_info info; 4288 u32 info_len = attr->info.info_len; 4289 struct bpf_prog_kstats stats; 4290 char __user *uinsns; 4291 u32 ulen; 4292 int err; 4293 4294 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4295 if (err) 4296 return err; 4297 info_len = min_t(u32, sizeof(info), info_len); 4298 4299 memset(&info, 0, sizeof(info)); 4300 if (copy_from_user(&info, uinfo, info_len)) 4301 return -EFAULT; 4302 4303 info.type = prog->type; 4304 info.id = prog->aux->id; 4305 info.load_time = prog->aux->load_time; 4306 info.created_by_uid = from_kuid_munged(current_user_ns(), 4307 prog->aux->user->uid); 4308 info.gpl_compatible = prog->gpl_compatible; 4309 4310 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 4311 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 4312 4313 mutex_lock(&prog->aux->used_maps_mutex); 4314 ulen = info.nr_map_ids; 4315 info.nr_map_ids = prog->aux->used_map_cnt; 4316 ulen = min_t(u32, info.nr_map_ids, ulen); 4317 if (ulen) { 4318 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 4319 u32 i; 4320 4321 for (i = 0; i < ulen; i++) 4322 if (put_user(prog->aux->used_maps[i]->id, 4323 &user_map_ids[i])) { 4324 mutex_unlock(&prog->aux->used_maps_mutex); 4325 return -EFAULT; 4326 } 4327 } 4328 mutex_unlock(&prog->aux->used_maps_mutex); 4329 4330 err = set_info_rec_size(&info); 4331 if (err) 4332 return err; 4333 4334 bpf_prog_get_stats(prog, &stats); 4335 info.run_time_ns = stats.nsecs; 4336 info.run_cnt = stats.cnt; 4337 info.recursion_misses = stats.misses; 4338 4339 info.verified_insns = prog->aux->verified_insns; 4340 4341 if (!bpf_capable()) { 4342 info.jited_prog_len = 0; 4343 info.xlated_prog_len = 0; 4344 info.nr_jited_ksyms = 0; 4345 info.nr_jited_func_lens = 0; 4346 info.nr_func_info = 0; 4347 info.nr_line_info = 0; 4348 info.nr_jited_line_info = 0; 4349 goto done; 4350 } 4351 4352 ulen = info.xlated_prog_len; 4353 info.xlated_prog_len = bpf_prog_insn_size(prog); 4354 if (info.xlated_prog_len && ulen) { 4355 struct bpf_insn *insns_sanitized; 4356 bool fault; 4357 4358 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) { 4359 info.xlated_prog_insns = 0; 4360 goto done; 4361 } 4362 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 4363 if (!insns_sanitized) 4364 return -ENOMEM; 4365 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 4366 ulen = min_t(u32, info.xlated_prog_len, ulen); 4367 fault = copy_to_user(uinsns, insns_sanitized, ulen); 4368 kfree(insns_sanitized); 4369 if (fault) 4370 return -EFAULT; 4371 } 4372 4373 if (bpf_prog_is_offloaded(prog->aux)) { 4374 err = bpf_prog_offload_info_fill(&info, prog); 4375 if (err) 4376 return err; 4377 goto done; 4378 } 4379 4380 /* NOTE: the following code is supposed to be skipped for offload. 4381 * bpf_prog_offload_info_fill() is the place to fill similar fields 4382 * for offload. 4383 */ 4384 ulen = info.jited_prog_len; 4385 if (prog->aux->func_cnt) { 4386 u32 i; 4387 4388 info.jited_prog_len = 0; 4389 for (i = 0; i < prog->aux->func_cnt; i++) 4390 info.jited_prog_len += prog->aux->func[i]->jited_len; 4391 } else { 4392 info.jited_prog_len = prog->jited_len; 4393 } 4394 4395 if (info.jited_prog_len && ulen) { 4396 if (bpf_dump_raw_ok(file->f_cred)) { 4397 uinsns = u64_to_user_ptr(info.jited_prog_insns); 4398 ulen = min_t(u32, info.jited_prog_len, ulen); 4399 4400 /* for multi-function programs, copy the JITed 4401 * instructions for all the functions 4402 */ 4403 if (prog->aux->func_cnt) { 4404 u32 len, free, i; 4405 u8 *img; 4406 4407 free = ulen; 4408 for (i = 0; i < prog->aux->func_cnt; i++) { 4409 len = prog->aux->func[i]->jited_len; 4410 len = min_t(u32, len, free); 4411 img = (u8 *) prog->aux->func[i]->bpf_func; 4412 if (copy_to_user(uinsns, img, len)) 4413 return -EFAULT; 4414 uinsns += len; 4415 free -= len; 4416 if (!free) 4417 break; 4418 } 4419 } else { 4420 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 4421 return -EFAULT; 4422 } 4423 } else { 4424 info.jited_prog_insns = 0; 4425 } 4426 } 4427 4428 ulen = info.nr_jited_ksyms; 4429 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 4430 if (ulen) { 4431 if (bpf_dump_raw_ok(file->f_cred)) { 4432 unsigned long ksym_addr; 4433 u64 __user *user_ksyms; 4434 u32 i; 4435 4436 /* copy the address of the kernel symbol 4437 * corresponding to each function 4438 */ 4439 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 4440 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 4441 if (prog->aux->func_cnt) { 4442 for (i = 0; i < ulen; i++) { 4443 ksym_addr = (unsigned long) 4444 prog->aux->func[i]->bpf_func; 4445 if (put_user((u64) ksym_addr, 4446 &user_ksyms[i])) 4447 return -EFAULT; 4448 } 4449 } else { 4450 ksym_addr = (unsigned long) prog->bpf_func; 4451 if (put_user((u64) ksym_addr, &user_ksyms[0])) 4452 return -EFAULT; 4453 } 4454 } else { 4455 info.jited_ksyms = 0; 4456 } 4457 } 4458 4459 ulen = info.nr_jited_func_lens; 4460 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 4461 if (ulen) { 4462 if (bpf_dump_raw_ok(file->f_cred)) { 4463 u32 __user *user_lens; 4464 u32 func_len, i; 4465 4466 /* copy the JITed image lengths for each function */ 4467 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 4468 user_lens = u64_to_user_ptr(info.jited_func_lens); 4469 if (prog->aux->func_cnt) { 4470 for (i = 0; i < ulen; i++) { 4471 func_len = 4472 prog->aux->func[i]->jited_len; 4473 if (put_user(func_len, &user_lens[i])) 4474 return -EFAULT; 4475 } 4476 } else { 4477 func_len = prog->jited_len; 4478 if (put_user(func_len, &user_lens[0])) 4479 return -EFAULT; 4480 } 4481 } else { 4482 info.jited_func_lens = 0; 4483 } 4484 } 4485 4486 if (prog->aux->btf) 4487 info.btf_id = btf_obj_id(prog->aux->btf); 4488 info.attach_btf_id = prog->aux->attach_btf_id; 4489 if (attach_btf) 4490 info.attach_btf_obj_id = btf_obj_id(attach_btf); 4491 4492 ulen = info.nr_func_info; 4493 info.nr_func_info = prog->aux->func_info_cnt; 4494 if (info.nr_func_info && ulen) { 4495 char __user *user_finfo; 4496 4497 user_finfo = u64_to_user_ptr(info.func_info); 4498 ulen = min_t(u32, info.nr_func_info, ulen); 4499 if (copy_to_user(user_finfo, prog->aux->func_info, 4500 info.func_info_rec_size * ulen)) 4501 return -EFAULT; 4502 } 4503 4504 ulen = info.nr_line_info; 4505 info.nr_line_info = prog->aux->nr_linfo; 4506 if (info.nr_line_info && ulen) { 4507 __u8 __user *user_linfo; 4508 4509 user_linfo = u64_to_user_ptr(info.line_info); 4510 ulen = min_t(u32, info.nr_line_info, ulen); 4511 if (copy_to_user(user_linfo, prog->aux->linfo, 4512 info.line_info_rec_size * ulen)) 4513 return -EFAULT; 4514 } 4515 4516 ulen = info.nr_jited_line_info; 4517 if (prog->aux->jited_linfo) 4518 info.nr_jited_line_info = prog->aux->nr_linfo; 4519 else 4520 info.nr_jited_line_info = 0; 4521 if (info.nr_jited_line_info && ulen) { 4522 if (bpf_dump_raw_ok(file->f_cred)) { 4523 unsigned long line_addr; 4524 __u64 __user *user_linfo; 4525 u32 i; 4526 4527 user_linfo = u64_to_user_ptr(info.jited_line_info); 4528 ulen = min_t(u32, info.nr_jited_line_info, ulen); 4529 for (i = 0; i < ulen; i++) { 4530 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 4531 if (put_user((__u64)line_addr, &user_linfo[i])) 4532 return -EFAULT; 4533 } 4534 } else { 4535 info.jited_line_info = 0; 4536 } 4537 } 4538 4539 ulen = info.nr_prog_tags; 4540 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 4541 if (ulen) { 4542 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 4543 u32 i; 4544 4545 user_prog_tags = u64_to_user_ptr(info.prog_tags); 4546 ulen = min_t(u32, info.nr_prog_tags, ulen); 4547 if (prog->aux->func_cnt) { 4548 for (i = 0; i < ulen; i++) { 4549 if (copy_to_user(user_prog_tags[i], 4550 prog->aux->func[i]->tag, 4551 BPF_TAG_SIZE)) 4552 return -EFAULT; 4553 } 4554 } else { 4555 if (copy_to_user(user_prog_tags[0], 4556 prog->tag, BPF_TAG_SIZE)) 4557 return -EFAULT; 4558 } 4559 } 4560 4561 done: 4562 if (copy_to_user(uinfo, &info, info_len) || 4563 put_user(info_len, &uattr->info.info_len)) 4564 return -EFAULT; 4565 4566 return 0; 4567 } 4568 4569 static int bpf_map_get_info_by_fd(struct file *file, 4570 struct bpf_map *map, 4571 const union bpf_attr *attr, 4572 union bpf_attr __user *uattr) 4573 { 4574 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4575 struct bpf_map_info info; 4576 u32 info_len = attr->info.info_len; 4577 int err; 4578 4579 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4580 if (err) 4581 return err; 4582 info_len = min_t(u32, sizeof(info), info_len); 4583 4584 memset(&info, 0, sizeof(info)); 4585 info.type = map->map_type; 4586 info.id = map->id; 4587 info.key_size = map->key_size; 4588 info.value_size = map->value_size; 4589 info.max_entries = map->max_entries; 4590 info.map_flags = map->map_flags; 4591 info.map_extra = map->map_extra; 4592 memcpy(info.name, map->name, sizeof(map->name)); 4593 4594 if (map->btf) { 4595 info.btf_id = btf_obj_id(map->btf); 4596 info.btf_key_type_id = map->btf_key_type_id; 4597 info.btf_value_type_id = map->btf_value_type_id; 4598 } 4599 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 4600 4601 if (bpf_map_is_offloaded(map)) { 4602 err = bpf_map_offload_info_fill(&info, map); 4603 if (err) 4604 return err; 4605 } 4606 4607 if (copy_to_user(uinfo, &info, info_len) || 4608 put_user(info_len, &uattr->info.info_len)) 4609 return -EFAULT; 4610 4611 return 0; 4612 } 4613 4614 static int bpf_btf_get_info_by_fd(struct file *file, 4615 struct btf *btf, 4616 const union bpf_attr *attr, 4617 union bpf_attr __user *uattr) 4618 { 4619 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4620 u32 info_len = attr->info.info_len; 4621 int err; 4622 4623 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 4624 if (err) 4625 return err; 4626 4627 return btf_get_info_by_fd(btf, attr, uattr); 4628 } 4629 4630 static int bpf_link_get_info_by_fd(struct file *file, 4631 struct bpf_link *link, 4632 const union bpf_attr *attr, 4633 union bpf_attr __user *uattr) 4634 { 4635 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4636 struct bpf_link_info info; 4637 u32 info_len = attr->info.info_len; 4638 int err; 4639 4640 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4641 if (err) 4642 return err; 4643 info_len = min_t(u32, sizeof(info), info_len); 4644 4645 memset(&info, 0, sizeof(info)); 4646 if (copy_from_user(&info, uinfo, info_len)) 4647 return -EFAULT; 4648 4649 info.type = link->type; 4650 info.id = link->id; 4651 if (link->prog) 4652 info.prog_id = link->prog->aux->id; 4653 4654 if (link->ops->fill_link_info) { 4655 err = link->ops->fill_link_info(link, &info); 4656 if (err) 4657 return err; 4658 } 4659 4660 if (copy_to_user(uinfo, &info, info_len) || 4661 put_user(info_len, &uattr->info.info_len)) 4662 return -EFAULT; 4663 4664 return 0; 4665 } 4666 4667 4668 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 4669 4670 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 4671 union bpf_attr __user *uattr) 4672 { 4673 int ufd = attr->info.bpf_fd; 4674 struct fd f; 4675 int err; 4676 4677 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 4678 return -EINVAL; 4679 4680 f = fdget(ufd); 4681 if (!f.file) 4682 return -EBADFD; 4683 4684 if (f.file->f_op == &bpf_prog_fops) 4685 err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr, 4686 uattr); 4687 else if (f.file->f_op == &bpf_map_fops) 4688 err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr, 4689 uattr); 4690 else if (f.file->f_op == &btf_fops) 4691 err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr); 4692 else if (f.file->f_op == &bpf_link_fops) 4693 err = bpf_link_get_info_by_fd(f.file, f.file->private_data, 4694 attr, uattr); 4695 else 4696 err = -EINVAL; 4697 4698 fdput(f); 4699 return err; 4700 } 4701 4702 #define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size 4703 4704 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) 4705 { 4706 if (CHECK_ATTR(BPF_BTF_LOAD)) 4707 return -EINVAL; 4708 4709 if (!bpf_capable()) 4710 return -EPERM; 4711 4712 return btf_new_fd(attr, uattr, uattr_size); 4713 } 4714 4715 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id 4716 4717 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 4718 { 4719 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 4720 return -EINVAL; 4721 4722 if (!capable(CAP_SYS_ADMIN)) 4723 return -EPERM; 4724 4725 return btf_get_fd_by_id(attr->btf_id); 4726 } 4727 4728 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 4729 union bpf_attr __user *uattr, 4730 u32 prog_id, u32 fd_type, 4731 const char *buf, u64 probe_offset, 4732 u64 probe_addr) 4733 { 4734 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 4735 u32 len = buf ? strlen(buf) : 0, input_len; 4736 int err = 0; 4737 4738 if (put_user(len, &uattr->task_fd_query.buf_len)) 4739 return -EFAULT; 4740 input_len = attr->task_fd_query.buf_len; 4741 if (input_len && ubuf) { 4742 if (!len) { 4743 /* nothing to copy, just make ubuf NULL terminated */ 4744 char zero = '\0'; 4745 4746 if (put_user(zero, ubuf)) 4747 return -EFAULT; 4748 } else if (input_len >= len + 1) { 4749 /* ubuf can hold the string with NULL terminator */ 4750 if (copy_to_user(ubuf, buf, len + 1)) 4751 return -EFAULT; 4752 } else { 4753 /* ubuf cannot hold the string with NULL terminator, 4754 * do a partial copy with NULL terminator. 4755 */ 4756 char zero = '\0'; 4757 4758 err = -ENOSPC; 4759 if (copy_to_user(ubuf, buf, input_len - 1)) 4760 return -EFAULT; 4761 if (put_user(zero, ubuf + input_len - 1)) 4762 return -EFAULT; 4763 } 4764 } 4765 4766 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 4767 put_user(fd_type, &uattr->task_fd_query.fd_type) || 4768 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 4769 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 4770 return -EFAULT; 4771 4772 return err; 4773 } 4774 4775 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 4776 4777 static int bpf_task_fd_query(const union bpf_attr *attr, 4778 union bpf_attr __user *uattr) 4779 { 4780 pid_t pid = attr->task_fd_query.pid; 4781 u32 fd = attr->task_fd_query.fd; 4782 const struct perf_event *event; 4783 struct task_struct *task; 4784 struct file *file; 4785 int err; 4786 4787 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 4788 return -EINVAL; 4789 4790 if (!capable(CAP_SYS_ADMIN)) 4791 return -EPERM; 4792 4793 if (attr->task_fd_query.flags != 0) 4794 return -EINVAL; 4795 4796 rcu_read_lock(); 4797 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 4798 rcu_read_unlock(); 4799 if (!task) 4800 return -ENOENT; 4801 4802 err = 0; 4803 file = fget_task(task, fd); 4804 put_task_struct(task); 4805 if (!file) 4806 return -EBADF; 4807 4808 if (file->f_op == &bpf_link_fops) { 4809 struct bpf_link *link = file->private_data; 4810 4811 if (link->ops == &bpf_raw_tp_link_lops) { 4812 struct bpf_raw_tp_link *raw_tp = 4813 container_of(link, struct bpf_raw_tp_link, link); 4814 struct bpf_raw_event_map *btp = raw_tp->btp; 4815 4816 err = bpf_task_fd_query_copy(attr, uattr, 4817 raw_tp->link.prog->aux->id, 4818 BPF_FD_TYPE_RAW_TRACEPOINT, 4819 btp->tp->name, 0, 0); 4820 goto put_file; 4821 } 4822 goto out_not_supp; 4823 } 4824 4825 event = perf_get_event(file); 4826 if (!IS_ERR(event)) { 4827 u64 probe_offset, probe_addr; 4828 u32 prog_id, fd_type; 4829 const char *buf; 4830 4831 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 4832 &buf, &probe_offset, 4833 &probe_addr, NULL); 4834 if (!err) 4835 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 4836 fd_type, buf, 4837 probe_offset, 4838 probe_addr); 4839 goto put_file; 4840 } 4841 4842 out_not_supp: 4843 err = -ENOTSUPP; 4844 put_file: 4845 fput(file); 4846 return err; 4847 } 4848 4849 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 4850 4851 #define BPF_DO_BATCH(fn, ...) \ 4852 do { \ 4853 if (!fn) { \ 4854 err = -ENOTSUPP; \ 4855 goto err_put; \ 4856 } \ 4857 err = fn(__VA_ARGS__); \ 4858 } while (0) 4859 4860 static int bpf_map_do_batch(const union bpf_attr *attr, 4861 union bpf_attr __user *uattr, 4862 int cmd) 4863 { 4864 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 4865 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 4866 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 4867 struct bpf_map *map; 4868 int err, ufd; 4869 struct fd f; 4870 4871 if (CHECK_ATTR(BPF_MAP_BATCH)) 4872 return -EINVAL; 4873 4874 ufd = attr->batch.map_fd; 4875 f = fdget(ufd); 4876 map = __bpf_map_get(f); 4877 if (IS_ERR(map)) 4878 return PTR_ERR(map); 4879 if (has_write) 4880 bpf_map_write_active_inc(map); 4881 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 4882 err = -EPERM; 4883 goto err_put; 4884 } 4885 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 4886 err = -EPERM; 4887 goto err_put; 4888 } 4889 4890 if (cmd == BPF_MAP_LOOKUP_BATCH) 4891 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 4892 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 4893 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 4894 else if (cmd == BPF_MAP_UPDATE_BATCH) 4895 BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr); 4896 else 4897 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 4898 err_put: 4899 if (has_write) 4900 bpf_map_write_active_dec(map); 4901 fdput(f); 4902 return err; 4903 } 4904 4905 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 4906 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 4907 { 4908 struct bpf_prog *prog; 4909 int ret; 4910 4911 if (CHECK_ATTR(BPF_LINK_CREATE)) 4912 return -EINVAL; 4913 4914 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 4915 return bpf_struct_ops_link_create(attr); 4916 4917 prog = bpf_prog_get(attr->link_create.prog_fd); 4918 if (IS_ERR(prog)) 4919 return PTR_ERR(prog); 4920 4921 ret = bpf_prog_attach_check_attach_type(prog, 4922 attr->link_create.attach_type); 4923 if (ret) 4924 goto out; 4925 4926 switch (prog->type) { 4927 case BPF_PROG_TYPE_CGROUP_SKB: 4928 case BPF_PROG_TYPE_CGROUP_SOCK: 4929 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4930 case BPF_PROG_TYPE_SOCK_OPS: 4931 case BPF_PROG_TYPE_CGROUP_DEVICE: 4932 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4933 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4934 ret = cgroup_bpf_link_attach(attr, prog); 4935 break; 4936 case BPF_PROG_TYPE_EXT: 4937 ret = bpf_tracing_prog_attach(prog, 4938 attr->link_create.target_fd, 4939 attr->link_create.target_btf_id, 4940 attr->link_create.tracing.cookie); 4941 break; 4942 case BPF_PROG_TYPE_LSM: 4943 case BPF_PROG_TYPE_TRACING: 4944 if (attr->link_create.attach_type != prog->expected_attach_type) { 4945 ret = -EINVAL; 4946 goto out; 4947 } 4948 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 4949 ret = bpf_raw_tp_link_attach(prog, NULL); 4950 else if (prog->expected_attach_type == BPF_TRACE_ITER) 4951 ret = bpf_iter_link_attach(attr, uattr, prog); 4952 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 4953 ret = cgroup_bpf_link_attach(attr, prog); 4954 else 4955 ret = bpf_tracing_prog_attach(prog, 4956 attr->link_create.target_fd, 4957 attr->link_create.target_btf_id, 4958 attr->link_create.tracing.cookie); 4959 break; 4960 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4961 case BPF_PROG_TYPE_SK_LOOKUP: 4962 ret = netns_bpf_link_create(attr, prog); 4963 break; 4964 #ifdef CONFIG_NET 4965 case BPF_PROG_TYPE_XDP: 4966 ret = bpf_xdp_link_attach(attr, prog); 4967 break; 4968 case BPF_PROG_TYPE_SCHED_CLS: 4969 ret = tcx_link_attach(attr, prog); 4970 break; 4971 case BPF_PROG_TYPE_NETFILTER: 4972 ret = bpf_nf_link_attach(attr, prog); 4973 break; 4974 #endif 4975 case BPF_PROG_TYPE_PERF_EVENT: 4976 case BPF_PROG_TYPE_TRACEPOINT: 4977 ret = bpf_perf_link_attach(attr, prog); 4978 break; 4979 case BPF_PROG_TYPE_KPROBE: 4980 if (attr->link_create.attach_type == BPF_PERF_EVENT) 4981 ret = bpf_perf_link_attach(attr, prog); 4982 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI) 4983 ret = bpf_kprobe_multi_link_attach(attr, prog); 4984 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI) 4985 ret = bpf_uprobe_multi_link_attach(attr, prog); 4986 break; 4987 default: 4988 ret = -EINVAL; 4989 } 4990 4991 out: 4992 if (ret < 0) 4993 bpf_prog_put(prog); 4994 return ret; 4995 } 4996 4997 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 4998 { 4999 struct bpf_map *new_map, *old_map = NULL; 5000 int ret; 5001 5002 new_map = bpf_map_get(attr->link_update.new_map_fd); 5003 if (IS_ERR(new_map)) 5004 return PTR_ERR(new_map); 5005 5006 if (attr->link_update.flags & BPF_F_REPLACE) { 5007 old_map = bpf_map_get(attr->link_update.old_map_fd); 5008 if (IS_ERR(old_map)) { 5009 ret = PTR_ERR(old_map); 5010 goto out_put; 5011 } 5012 } else if (attr->link_update.old_map_fd) { 5013 ret = -EINVAL; 5014 goto out_put; 5015 } 5016 5017 ret = link->ops->update_map(link, new_map, old_map); 5018 5019 if (old_map) 5020 bpf_map_put(old_map); 5021 out_put: 5022 bpf_map_put(new_map); 5023 return ret; 5024 } 5025 5026 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5027 5028 static int link_update(union bpf_attr *attr) 5029 { 5030 struct bpf_prog *old_prog = NULL, *new_prog; 5031 struct bpf_link *link; 5032 u32 flags; 5033 int ret; 5034 5035 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5036 return -EINVAL; 5037 5038 flags = attr->link_update.flags; 5039 if (flags & ~BPF_F_REPLACE) 5040 return -EINVAL; 5041 5042 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5043 if (IS_ERR(link)) 5044 return PTR_ERR(link); 5045 5046 if (link->ops->update_map) { 5047 ret = link_update_map(link, attr); 5048 goto out_put_link; 5049 } 5050 5051 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5052 if (IS_ERR(new_prog)) { 5053 ret = PTR_ERR(new_prog); 5054 goto out_put_link; 5055 } 5056 5057 if (flags & BPF_F_REPLACE) { 5058 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5059 if (IS_ERR(old_prog)) { 5060 ret = PTR_ERR(old_prog); 5061 old_prog = NULL; 5062 goto out_put_progs; 5063 } 5064 } else if (attr->link_update.old_prog_fd) { 5065 ret = -EINVAL; 5066 goto out_put_progs; 5067 } 5068 5069 if (link->ops->update_prog) 5070 ret = link->ops->update_prog(link, new_prog, old_prog); 5071 else 5072 ret = -EINVAL; 5073 5074 out_put_progs: 5075 if (old_prog) 5076 bpf_prog_put(old_prog); 5077 if (ret) 5078 bpf_prog_put(new_prog); 5079 out_put_link: 5080 bpf_link_put_direct(link); 5081 return ret; 5082 } 5083 5084 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5085 5086 static int link_detach(union bpf_attr *attr) 5087 { 5088 struct bpf_link *link; 5089 int ret; 5090 5091 if (CHECK_ATTR(BPF_LINK_DETACH)) 5092 return -EINVAL; 5093 5094 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 5095 if (IS_ERR(link)) 5096 return PTR_ERR(link); 5097 5098 if (link->ops->detach) 5099 ret = link->ops->detach(link); 5100 else 5101 ret = -EOPNOTSUPP; 5102 5103 bpf_link_put_direct(link); 5104 return ret; 5105 } 5106 5107 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 5108 { 5109 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 5110 } 5111 5112 struct bpf_link *bpf_link_by_id(u32 id) 5113 { 5114 struct bpf_link *link; 5115 5116 if (!id) 5117 return ERR_PTR(-ENOENT); 5118 5119 spin_lock_bh(&link_idr_lock); 5120 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 5121 link = idr_find(&link_idr, id); 5122 if (link) { 5123 if (link->id) 5124 link = bpf_link_inc_not_zero(link); 5125 else 5126 link = ERR_PTR(-EAGAIN); 5127 } else { 5128 link = ERR_PTR(-ENOENT); 5129 } 5130 spin_unlock_bh(&link_idr_lock); 5131 return link; 5132 } 5133 5134 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 5135 { 5136 struct bpf_link *link; 5137 5138 spin_lock_bh(&link_idr_lock); 5139 again: 5140 link = idr_get_next(&link_idr, id); 5141 if (link) { 5142 link = bpf_link_inc_not_zero(link); 5143 if (IS_ERR(link)) { 5144 (*id)++; 5145 goto again; 5146 } 5147 } 5148 spin_unlock_bh(&link_idr_lock); 5149 5150 return link; 5151 } 5152 5153 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 5154 5155 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 5156 { 5157 struct bpf_link *link; 5158 u32 id = attr->link_id; 5159 int fd; 5160 5161 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 5162 return -EINVAL; 5163 5164 if (!capable(CAP_SYS_ADMIN)) 5165 return -EPERM; 5166 5167 link = bpf_link_by_id(id); 5168 if (IS_ERR(link)) 5169 return PTR_ERR(link); 5170 5171 fd = bpf_link_new_fd(link); 5172 if (fd < 0) 5173 bpf_link_put_direct(link); 5174 5175 return fd; 5176 } 5177 5178 DEFINE_MUTEX(bpf_stats_enabled_mutex); 5179 5180 static int bpf_stats_release(struct inode *inode, struct file *file) 5181 { 5182 mutex_lock(&bpf_stats_enabled_mutex); 5183 static_key_slow_dec(&bpf_stats_enabled_key.key); 5184 mutex_unlock(&bpf_stats_enabled_mutex); 5185 return 0; 5186 } 5187 5188 static const struct file_operations bpf_stats_fops = { 5189 .release = bpf_stats_release, 5190 }; 5191 5192 static int bpf_enable_runtime_stats(void) 5193 { 5194 int fd; 5195 5196 mutex_lock(&bpf_stats_enabled_mutex); 5197 5198 /* Set a very high limit to avoid overflow */ 5199 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 5200 mutex_unlock(&bpf_stats_enabled_mutex); 5201 return -EBUSY; 5202 } 5203 5204 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 5205 if (fd >= 0) 5206 static_key_slow_inc(&bpf_stats_enabled_key.key); 5207 5208 mutex_unlock(&bpf_stats_enabled_mutex); 5209 return fd; 5210 } 5211 5212 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 5213 5214 static int bpf_enable_stats(union bpf_attr *attr) 5215 { 5216 5217 if (CHECK_ATTR(BPF_ENABLE_STATS)) 5218 return -EINVAL; 5219 5220 if (!capable(CAP_SYS_ADMIN)) 5221 return -EPERM; 5222 5223 switch (attr->enable_stats.type) { 5224 case BPF_STATS_RUN_TIME: 5225 return bpf_enable_runtime_stats(); 5226 default: 5227 break; 5228 } 5229 return -EINVAL; 5230 } 5231 5232 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 5233 5234 static int bpf_iter_create(union bpf_attr *attr) 5235 { 5236 struct bpf_link *link; 5237 int err; 5238 5239 if (CHECK_ATTR(BPF_ITER_CREATE)) 5240 return -EINVAL; 5241 5242 if (attr->iter_create.flags) 5243 return -EINVAL; 5244 5245 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 5246 if (IS_ERR(link)) 5247 return PTR_ERR(link); 5248 5249 err = bpf_iter_new_fd(link); 5250 bpf_link_put_direct(link); 5251 5252 return err; 5253 } 5254 5255 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 5256 5257 static int bpf_prog_bind_map(union bpf_attr *attr) 5258 { 5259 struct bpf_prog *prog; 5260 struct bpf_map *map; 5261 struct bpf_map **used_maps_old, **used_maps_new; 5262 int i, ret = 0; 5263 5264 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 5265 return -EINVAL; 5266 5267 if (attr->prog_bind_map.flags) 5268 return -EINVAL; 5269 5270 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 5271 if (IS_ERR(prog)) 5272 return PTR_ERR(prog); 5273 5274 map = bpf_map_get(attr->prog_bind_map.map_fd); 5275 if (IS_ERR(map)) { 5276 ret = PTR_ERR(map); 5277 goto out_prog_put; 5278 } 5279 5280 mutex_lock(&prog->aux->used_maps_mutex); 5281 5282 used_maps_old = prog->aux->used_maps; 5283 5284 for (i = 0; i < prog->aux->used_map_cnt; i++) 5285 if (used_maps_old[i] == map) { 5286 bpf_map_put(map); 5287 goto out_unlock; 5288 } 5289 5290 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, 5291 sizeof(used_maps_new[0]), 5292 GFP_KERNEL); 5293 if (!used_maps_new) { 5294 ret = -ENOMEM; 5295 goto out_unlock; 5296 } 5297 5298 memcpy(used_maps_new, used_maps_old, 5299 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 5300 used_maps_new[prog->aux->used_map_cnt] = map; 5301 5302 prog->aux->used_map_cnt++; 5303 prog->aux->used_maps = used_maps_new; 5304 5305 kfree(used_maps_old); 5306 5307 out_unlock: 5308 mutex_unlock(&prog->aux->used_maps_mutex); 5309 5310 if (ret) 5311 bpf_map_put(map); 5312 out_prog_put: 5313 bpf_prog_put(prog); 5314 return ret; 5315 } 5316 5317 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size) 5318 { 5319 union bpf_attr attr; 5320 int err; 5321 5322 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 5323 if (err) 5324 return err; 5325 size = min_t(u32, size, sizeof(attr)); 5326 5327 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 5328 memset(&attr, 0, sizeof(attr)); 5329 if (copy_from_bpfptr(&attr, uattr, size) != 0) 5330 return -EFAULT; 5331 5332 err = security_bpf(cmd, &attr, size); 5333 if (err < 0) 5334 return err; 5335 5336 switch (cmd) { 5337 case BPF_MAP_CREATE: 5338 err = map_create(&attr); 5339 break; 5340 case BPF_MAP_LOOKUP_ELEM: 5341 err = map_lookup_elem(&attr); 5342 break; 5343 case BPF_MAP_UPDATE_ELEM: 5344 err = map_update_elem(&attr, uattr); 5345 break; 5346 case BPF_MAP_DELETE_ELEM: 5347 err = map_delete_elem(&attr, uattr); 5348 break; 5349 case BPF_MAP_GET_NEXT_KEY: 5350 err = map_get_next_key(&attr); 5351 break; 5352 case BPF_MAP_FREEZE: 5353 err = map_freeze(&attr); 5354 break; 5355 case BPF_PROG_LOAD: 5356 err = bpf_prog_load(&attr, uattr, size); 5357 break; 5358 case BPF_OBJ_PIN: 5359 err = bpf_obj_pin(&attr); 5360 break; 5361 case BPF_OBJ_GET: 5362 err = bpf_obj_get(&attr); 5363 break; 5364 case BPF_PROG_ATTACH: 5365 err = bpf_prog_attach(&attr); 5366 break; 5367 case BPF_PROG_DETACH: 5368 err = bpf_prog_detach(&attr); 5369 break; 5370 case BPF_PROG_QUERY: 5371 err = bpf_prog_query(&attr, uattr.user); 5372 break; 5373 case BPF_PROG_TEST_RUN: 5374 err = bpf_prog_test_run(&attr, uattr.user); 5375 break; 5376 case BPF_PROG_GET_NEXT_ID: 5377 err = bpf_obj_get_next_id(&attr, uattr.user, 5378 &prog_idr, &prog_idr_lock); 5379 break; 5380 case BPF_MAP_GET_NEXT_ID: 5381 err = bpf_obj_get_next_id(&attr, uattr.user, 5382 &map_idr, &map_idr_lock); 5383 break; 5384 case BPF_BTF_GET_NEXT_ID: 5385 err = bpf_obj_get_next_id(&attr, uattr.user, 5386 &btf_idr, &btf_idr_lock); 5387 break; 5388 case BPF_PROG_GET_FD_BY_ID: 5389 err = bpf_prog_get_fd_by_id(&attr); 5390 break; 5391 case BPF_MAP_GET_FD_BY_ID: 5392 err = bpf_map_get_fd_by_id(&attr); 5393 break; 5394 case BPF_OBJ_GET_INFO_BY_FD: 5395 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 5396 break; 5397 case BPF_RAW_TRACEPOINT_OPEN: 5398 err = bpf_raw_tracepoint_open(&attr); 5399 break; 5400 case BPF_BTF_LOAD: 5401 err = bpf_btf_load(&attr, uattr, size); 5402 break; 5403 case BPF_BTF_GET_FD_BY_ID: 5404 err = bpf_btf_get_fd_by_id(&attr); 5405 break; 5406 case BPF_TASK_FD_QUERY: 5407 err = bpf_task_fd_query(&attr, uattr.user); 5408 break; 5409 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 5410 err = map_lookup_and_delete_elem(&attr); 5411 break; 5412 case BPF_MAP_LOOKUP_BATCH: 5413 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 5414 break; 5415 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 5416 err = bpf_map_do_batch(&attr, uattr.user, 5417 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 5418 break; 5419 case BPF_MAP_UPDATE_BATCH: 5420 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 5421 break; 5422 case BPF_MAP_DELETE_BATCH: 5423 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 5424 break; 5425 case BPF_LINK_CREATE: 5426 err = link_create(&attr, uattr); 5427 break; 5428 case BPF_LINK_UPDATE: 5429 err = link_update(&attr); 5430 break; 5431 case BPF_LINK_GET_FD_BY_ID: 5432 err = bpf_link_get_fd_by_id(&attr); 5433 break; 5434 case BPF_LINK_GET_NEXT_ID: 5435 err = bpf_obj_get_next_id(&attr, uattr.user, 5436 &link_idr, &link_idr_lock); 5437 break; 5438 case BPF_ENABLE_STATS: 5439 err = bpf_enable_stats(&attr); 5440 break; 5441 case BPF_ITER_CREATE: 5442 err = bpf_iter_create(&attr); 5443 break; 5444 case BPF_LINK_DETACH: 5445 err = link_detach(&attr); 5446 break; 5447 case BPF_PROG_BIND_MAP: 5448 err = bpf_prog_bind_map(&attr); 5449 break; 5450 default: 5451 err = -EINVAL; 5452 break; 5453 } 5454 5455 return err; 5456 } 5457 5458 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) 5459 { 5460 return __sys_bpf(cmd, USER_BPFPTR(uattr), size); 5461 } 5462 5463 static bool syscall_prog_is_valid_access(int off, int size, 5464 enum bpf_access_type type, 5465 const struct bpf_prog *prog, 5466 struct bpf_insn_access_aux *info) 5467 { 5468 if (off < 0 || off >= U16_MAX) 5469 return false; 5470 if (off % size != 0) 5471 return false; 5472 return true; 5473 } 5474 5475 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 5476 { 5477 switch (cmd) { 5478 case BPF_MAP_CREATE: 5479 case BPF_MAP_DELETE_ELEM: 5480 case BPF_MAP_UPDATE_ELEM: 5481 case BPF_MAP_FREEZE: 5482 case BPF_MAP_GET_FD_BY_ID: 5483 case BPF_PROG_LOAD: 5484 case BPF_BTF_LOAD: 5485 case BPF_LINK_CREATE: 5486 case BPF_RAW_TRACEPOINT_OPEN: 5487 break; 5488 default: 5489 return -EINVAL; 5490 } 5491 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); 5492 } 5493 5494 5495 /* To shut up -Wmissing-prototypes. 5496 * This function is used by the kernel light skeleton 5497 * to load bpf programs when modules are loaded or during kernel boot. 5498 * See tools/lib/bpf/skel_internal.h 5499 */ 5500 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 5501 5502 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 5503 { 5504 struct bpf_prog * __maybe_unused prog; 5505 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 5506 5507 switch (cmd) { 5508 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 5509 case BPF_PROG_TEST_RUN: 5510 if (attr->test.data_in || attr->test.data_out || 5511 attr->test.ctx_out || attr->test.duration || 5512 attr->test.repeat || attr->test.flags) 5513 return -EINVAL; 5514 5515 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 5516 if (IS_ERR(prog)) 5517 return PTR_ERR(prog); 5518 5519 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 5520 attr->test.ctx_size_in > U16_MAX) { 5521 bpf_prog_put(prog); 5522 return -EINVAL; 5523 } 5524 5525 run_ctx.bpf_cookie = 0; 5526 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 5527 /* recursion detected */ 5528 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 5529 bpf_prog_put(prog); 5530 return -EBUSY; 5531 } 5532 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 5533 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 5534 &run_ctx); 5535 bpf_prog_put(prog); 5536 return 0; 5537 #endif 5538 default: 5539 return ____bpf_sys_bpf(cmd, attr, size); 5540 } 5541 } 5542 EXPORT_SYMBOL(kern_sys_bpf); 5543 5544 static const struct bpf_func_proto bpf_sys_bpf_proto = { 5545 .func = bpf_sys_bpf, 5546 .gpl_only = false, 5547 .ret_type = RET_INTEGER, 5548 .arg1_type = ARG_ANYTHING, 5549 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 5550 .arg3_type = ARG_CONST_SIZE, 5551 }; 5552 5553 const struct bpf_func_proto * __weak 5554 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5555 { 5556 return bpf_base_func_proto(func_id); 5557 } 5558 5559 BPF_CALL_1(bpf_sys_close, u32, fd) 5560 { 5561 /* When bpf program calls this helper there should not be 5562 * an fdget() without matching completed fdput(). 5563 * This helper is allowed in the following callchain only: 5564 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 5565 */ 5566 return close_fd(fd); 5567 } 5568 5569 static const struct bpf_func_proto bpf_sys_close_proto = { 5570 .func = bpf_sys_close, 5571 .gpl_only = false, 5572 .ret_type = RET_INTEGER, 5573 .arg1_type = ARG_ANYTHING, 5574 }; 5575 5576 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 5577 { 5578 if (flags) 5579 return -EINVAL; 5580 5581 if (name_sz <= 1 || name[name_sz - 1]) 5582 return -EINVAL; 5583 5584 if (!bpf_dump_raw_ok(current_cred())) 5585 return -EPERM; 5586 5587 *res = kallsyms_lookup_name(name); 5588 return *res ? 0 : -ENOENT; 5589 } 5590 5591 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 5592 .func = bpf_kallsyms_lookup_name, 5593 .gpl_only = false, 5594 .ret_type = RET_INTEGER, 5595 .arg1_type = ARG_PTR_TO_MEM, 5596 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 5597 .arg3_type = ARG_ANYTHING, 5598 .arg4_type = ARG_PTR_TO_LONG, 5599 }; 5600 5601 static const struct bpf_func_proto * 5602 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5603 { 5604 switch (func_id) { 5605 case BPF_FUNC_sys_bpf: 5606 return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto; 5607 case BPF_FUNC_btf_find_by_name_kind: 5608 return &bpf_btf_find_by_name_kind_proto; 5609 case BPF_FUNC_sys_close: 5610 return &bpf_sys_close_proto; 5611 case BPF_FUNC_kallsyms_lookup_name: 5612 return &bpf_kallsyms_lookup_name_proto; 5613 default: 5614 return tracing_prog_func_proto(func_id, prog); 5615 } 5616 } 5617 5618 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 5619 .get_func_proto = syscall_prog_func_proto, 5620 .is_valid_access = syscall_prog_is_valid_access, 5621 }; 5622 5623 const struct bpf_prog_ops bpf_syscall_prog_ops = { 5624 .test_run = bpf_prog_test_run_syscall, 5625 }; 5626 5627 #ifdef CONFIG_SYSCTL 5628 static int bpf_stats_handler(struct ctl_table *table, int write, 5629 void *buffer, size_t *lenp, loff_t *ppos) 5630 { 5631 struct static_key *key = (struct static_key *)table->data; 5632 static int saved_val; 5633 int val, ret; 5634 struct ctl_table tmp = { 5635 .data = &val, 5636 .maxlen = sizeof(val), 5637 .mode = table->mode, 5638 .extra1 = SYSCTL_ZERO, 5639 .extra2 = SYSCTL_ONE, 5640 }; 5641 5642 if (write && !capable(CAP_SYS_ADMIN)) 5643 return -EPERM; 5644 5645 mutex_lock(&bpf_stats_enabled_mutex); 5646 val = saved_val; 5647 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5648 if (write && !ret && val != saved_val) { 5649 if (val) 5650 static_key_slow_inc(key); 5651 else 5652 static_key_slow_dec(key); 5653 saved_val = val; 5654 } 5655 mutex_unlock(&bpf_stats_enabled_mutex); 5656 return ret; 5657 } 5658 5659 void __weak unpriv_ebpf_notify(int new_state) 5660 { 5661 } 5662 5663 static int bpf_unpriv_handler(struct ctl_table *table, int write, 5664 void *buffer, size_t *lenp, loff_t *ppos) 5665 { 5666 int ret, unpriv_enable = *(int *)table->data; 5667 bool locked_state = unpriv_enable == 1; 5668 struct ctl_table tmp = *table; 5669 5670 if (write && !capable(CAP_SYS_ADMIN)) 5671 return -EPERM; 5672 5673 tmp.data = &unpriv_enable; 5674 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5675 if (write && !ret) { 5676 if (locked_state && unpriv_enable != 1) 5677 return -EPERM; 5678 *(int *)table->data = unpriv_enable; 5679 } 5680 5681 if (write) 5682 unpriv_ebpf_notify(unpriv_enable); 5683 5684 return ret; 5685 } 5686 5687 static struct ctl_table bpf_syscall_table[] = { 5688 { 5689 .procname = "unprivileged_bpf_disabled", 5690 .data = &sysctl_unprivileged_bpf_disabled, 5691 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 5692 .mode = 0644, 5693 .proc_handler = bpf_unpriv_handler, 5694 .extra1 = SYSCTL_ZERO, 5695 .extra2 = SYSCTL_TWO, 5696 }, 5697 { 5698 .procname = "bpf_stats_enabled", 5699 .data = &bpf_stats_enabled_key.key, 5700 .mode = 0644, 5701 .proc_handler = bpf_stats_handler, 5702 }, 5703 { } 5704 }; 5705 5706 static int __init bpf_syscall_sysctl_init(void) 5707 { 5708 register_sysctl_init("kernel", bpf_syscall_table); 5709 return 0; 5710 } 5711 late_initcall(bpf_syscall_sysctl_init); 5712 #endif /* CONFIG_SYSCTL */ 5713