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