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 struct btf *btf = map->btf; 696 697 security_bpf_map_free(map); 698 bpf_map_release_memcg(map); 699 /* implementation dependent freeing */ 700 map->ops->map_free(map); 701 /* Delay freeing of btf_record for maps, as map_free 702 * callback usually needs access to them. It is better to do it here 703 * than require each callback to do the free itself manually. 704 * 705 * Note that the btf_record stashed in map->inner_map_meta->record was 706 * already freed using the map_free callback for map in map case which 707 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 708 * template bpf_map struct used during verification. 709 */ 710 btf_record_free(rec); 711 /* Delay freeing of btf for maps, as map_free callback may need 712 * struct_meta info which will be freed with btf_put(). 713 */ 714 btf_put(btf); 715 } 716 717 static void bpf_map_put_uref(struct bpf_map *map) 718 { 719 if (atomic64_dec_and_test(&map->usercnt)) { 720 if (map->ops->map_release_uref) 721 map->ops->map_release_uref(map); 722 } 723 } 724 725 static void bpf_map_free_in_work(struct bpf_map *map) 726 { 727 INIT_WORK(&map->work, bpf_map_free_deferred); 728 /* Avoid spawning kworkers, since they all might contend 729 * for the same mutex like slab_mutex. 730 */ 731 queue_work(system_unbound_wq, &map->work); 732 } 733 734 static void bpf_map_free_rcu_gp(struct rcu_head *rcu) 735 { 736 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); 737 } 738 739 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu) 740 { 741 if (rcu_trace_implies_rcu_gp()) 742 bpf_map_free_rcu_gp(rcu); 743 else 744 call_rcu(rcu, bpf_map_free_rcu_gp); 745 } 746 747 /* decrement map refcnt and schedule it for freeing via workqueue 748 * (underlying map implementation ops->map_free() might sleep) 749 */ 750 void bpf_map_put(struct bpf_map *map) 751 { 752 if (atomic64_dec_and_test(&map->refcnt)) { 753 /* bpf_map_free_id() must be called first */ 754 bpf_map_free_id(map); 755 756 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); 757 if (READ_ONCE(map->free_after_mult_rcu_gp)) 758 call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp); 759 else if (READ_ONCE(map->free_after_rcu_gp)) 760 call_rcu(&map->rcu, bpf_map_free_rcu_gp); 761 else 762 bpf_map_free_in_work(map); 763 } 764 } 765 EXPORT_SYMBOL_GPL(bpf_map_put); 766 767 void bpf_map_put_with_uref(struct bpf_map *map) 768 { 769 bpf_map_put_uref(map); 770 bpf_map_put(map); 771 } 772 773 static int bpf_map_release(struct inode *inode, struct file *filp) 774 { 775 struct bpf_map *map = filp->private_data; 776 777 if (map->ops->map_release) 778 map->ops->map_release(map, filp); 779 780 bpf_map_put_with_uref(map); 781 return 0; 782 } 783 784 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 785 { 786 fmode_t mode = f.file->f_mode; 787 788 /* Our file permissions may have been overridden by global 789 * map permissions facing syscall side. 790 */ 791 if (READ_ONCE(map->frozen)) 792 mode &= ~FMODE_CAN_WRITE; 793 return mode; 794 } 795 796 #ifdef CONFIG_PROC_FS 797 /* Show the memory usage of a bpf map */ 798 static u64 bpf_map_memory_usage(const struct bpf_map *map) 799 { 800 return map->ops->map_mem_usage(map); 801 } 802 803 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 804 { 805 struct bpf_map *map = filp->private_data; 806 u32 type = 0, jited = 0; 807 808 if (map_type_contains_progs(map)) { 809 spin_lock(&map->owner.lock); 810 type = map->owner.type; 811 jited = map->owner.jited; 812 spin_unlock(&map->owner.lock); 813 } 814 815 seq_printf(m, 816 "map_type:\t%u\n" 817 "key_size:\t%u\n" 818 "value_size:\t%u\n" 819 "max_entries:\t%u\n" 820 "map_flags:\t%#x\n" 821 "map_extra:\t%#llx\n" 822 "memlock:\t%llu\n" 823 "map_id:\t%u\n" 824 "frozen:\t%u\n", 825 map->map_type, 826 map->key_size, 827 map->value_size, 828 map->max_entries, 829 map->map_flags, 830 (unsigned long long)map->map_extra, 831 bpf_map_memory_usage(map), 832 map->id, 833 READ_ONCE(map->frozen)); 834 if (type) { 835 seq_printf(m, "owner_prog_type:\t%u\n", type); 836 seq_printf(m, "owner_jited:\t%u\n", jited); 837 } 838 } 839 #endif 840 841 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 842 loff_t *ppos) 843 { 844 /* We need this handler such that alloc_file() enables 845 * f_mode with FMODE_CAN_READ. 846 */ 847 return -EINVAL; 848 } 849 850 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 851 size_t siz, loff_t *ppos) 852 { 853 /* We need this handler such that alloc_file() enables 854 * f_mode with FMODE_CAN_WRITE. 855 */ 856 return -EINVAL; 857 } 858 859 /* called for any extra memory-mapped regions (except initial) */ 860 static void bpf_map_mmap_open(struct vm_area_struct *vma) 861 { 862 struct bpf_map *map = vma->vm_file->private_data; 863 864 if (vma->vm_flags & VM_MAYWRITE) 865 bpf_map_write_active_inc(map); 866 } 867 868 /* called for all unmapped memory region (including initial) */ 869 static void bpf_map_mmap_close(struct vm_area_struct *vma) 870 { 871 struct bpf_map *map = vma->vm_file->private_data; 872 873 if (vma->vm_flags & VM_MAYWRITE) 874 bpf_map_write_active_dec(map); 875 } 876 877 static const struct vm_operations_struct bpf_map_default_vmops = { 878 .open = bpf_map_mmap_open, 879 .close = bpf_map_mmap_close, 880 }; 881 882 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 883 { 884 struct bpf_map *map = filp->private_data; 885 int err; 886 887 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 888 return -ENOTSUPP; 889 890 if (!(vma->vm_flags & VM_SHARED)) 891 return -EINVAL; 892 893 mutex_lock(&map->freeze_mutex); 894 895 if (vma->vm_flags & VM_WRITE) { 896 if (map->frozen) { 897 err = -EPERM; 898 goto out; 899 } 900 /* map is meant to be read-only, so do not allow mapping as 901 * writable, because it's possible to leak a writable page 902 * reference and allows user-space to still modify it after 903 * freezing, while verifier will assume contents do not change 904 */ 905 if (map->map_flags & BPF_F_RDONLY_PROG) { 906 err = -EACCES; 907 goto out; 908 } 909 } 910 911 /* set default open/close callbacks */ 912 vma->vm_ops = &bpf_map_default_vmops; 913 vma->vm_private_data = map; 914 vm_flags_clear(vma, VM_MAYEXEC); 915 if (!(vma->vm_flags & VM_WRITE)) 916 /* disallow re-mapping with PROT_WRITE */ 917 vm_flags_clear(vma, VM_MAYWRITE); 918 919 err = map->ops->map_mmap(map, vma); 920 if (err) 921 goto out; 922 923 if (vma->vm_flags & VM_MAYWRITE) 924 bpf_map_write_active_inc(map); 925 out: 926 mutex_unlock(&map->freeze_mutex); 927 return err; 928 } 929 930 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 931 { 932 struct bpf_map *map = filp->private_data; 933 934 if (map->ops->map_poll) 935 return map->ops->map_poll(map, filp, pts); 936 937 return EPOLLERR; 938 } 939 940 const struct file_operations bpf_map_fops = { 941 #ifdef CONFIG_PROC_FS 942 .show_fdinfo = bpf_map_show_fdinfo, 943 #endif 944 .release = bpf_map_release, 945 .read = bpf_dummy_read, 946 .write = bpf_dummy_write, 947 .mmap = bpf_map_mmap, 948 .poll = bpf_map_poll, 949 }; 950 951 int bpf_map_new_fd(struct bpf_map *map, int flags) 952 { 953 int ret; 954 955 ret = security_bpf_map(map, OPEN_FMODE(flags)); 956 if (ret < 0) 957 return ret; 958 959 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 960 flags | O_CLOEXEC); 961 } 962 963 int bpf_get_file_flag(int flags) 964 { 965 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 966 return -EINVAL; 967 if (flags & BPF_F_RDONLY) 968 return O_RDONLY; 969 if (flags & BPF_F_WRONLY) 970 return O_WRONLY; 971 return O_RDWR; 972 } 973 974 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 975 #define CHECK_ATTR(CMD) \ 976 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 977 sizeof(attr->CMD##_LAST_FIELD), 0, \ 978 sizeof(*attr) - \ 979 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 980 sizeof(attr->CMD##_LAST_FIELD)) != NULL 981 982 /* dst and src must have at least "size" number of bytes. 983 * Return strlen on success and < 0 on error. 984 */ 985 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 986 { 987 const char *end = src + size; 988 const char *orig_src = src; 989 990 memset(dst, 0, size); 991 /* Copy all isalnum(), '_' and '.' chars. */ 992 while (src < end && *src) { 993 if (!isalnum(*src) && 994 *src != '_' && *src != '.') 995 return -EINVAL; 996 *dst++ = *src++; 997 } 998 999 /* No '\0' found in "size" number of bytes */ 1000 if (src == end) 1001 return -EINVAL; 1002 1003 return src - orig_src; 1004 } 1005 1006 int map_check_no_btf(const struct bpf_map *map, 1007 const struct btf *btf, 1008 const struct btf_type *key_type, 1009 const struct btf_type *value_type) 1010 { 1011 return -ENOTSUPP; 1012 } 1013 1014 static int map_check_btf(struct bpf_map *map, const struct btf *btf, 1015 u32 btf_key_id, u32 btf_value_id) 1016 { 1017 const struct btf_type *key_type, *value_type; 1018 u32 key_size, value_size; 1019 int ret = 0; 1020 1021 /* Some maps allow key to be unspecified. */ 1022 if (btf_key_id) { 1023 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 1024 if (!key_type || key_size != map->key_size) 1025 return -EINVAL; 1026 } else { 1027 key_type = btf_type_by_id(btf, 0); 1028 if (!map->ops->map_check_btf) 1029 return -EINVAL; 1030 } 1031 1032 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1033 if (!value_type || value_size != map->value_size) 1034 return -EINVAL; 1035 1036 map->record = btf_parse_fields(btf, value_type, 1037 BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1038 BPF_RB_ROOT | BPF_REFCOUNT, 1039 map->value_size); 1040 if (!IS_ERR_OR_NULL(map->record)) { 1041 int i; 1042 1043 if (!bpf_capable()) { 1044 ret = -EPERM; 1045 goto free_map_tab; 1046 } 1047 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1048 ret = -EACCES; 1049 goto free_map_tab; 1050 } 1051 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1052 switch (map->record->field_mask & (1 << i)) { 1053 case 0: 1054 continue; 1055 case BPF_SPIN_LOCK: 1056 if (map->map_type != BPF_MAP_TYPE_HASH && 1057 map->map_type != BPF_MAP_TYPE_ARRAY && 1058 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1059 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1060 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1061 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1062 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1063 ret = -EOPNOTSUPP; 1064 goto free_map_tab; 1065 } 1066 break; 1067 case BPF_TIMER: 1068 if (map->map_type != BPF_MAP_TYPE_HASH && 1069 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1070 map->map_type != BPF_MAP_TYPE_ARRAY) { 1071 ret = -EOPNOTSUPP; 1072 goto free_map_tab; 1073 } 1074 break; 1075 case BPF_KPTR_UNREF: 1076 case BPF_KPTR_REF: 1077 case BPF_REFCOUNT: 1078 if (map->map_type != BPF_MAP_TYPE_HASH && 1079 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1080 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1081 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1082 map->map_type != BPF_MAP_TYPE_ARRAY && 1083 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1084 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1085 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1086 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1087 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1088 ret = -EOPNOTSUPP; 1089 goto free_map_tab; 1090 } 1091 break; 1092 case BPF_LIST_HEAD: 1093 case BPF_RB_ROOT: 1094 if (map->map_type != BPF_MAP_TYPE_HASH && 1095 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1096 map->map_type != BPF_MAP_TYPE_ARRAY) { 1097 ret = -EOPNOTSUPP; 1098 goto free_map_tab; 1099 } 1100 break; 1101 default: 1102 /* Fail if map_type checks are missing for a field type */ 1103 ret = -EOPNOTSUPP; 1104 goto free_map_tab; 1105 } 1106 } 1107 } 1108 1109 ret = btf_check_and_fixup_fields(btf, map->record); 1110 if (ret < 0) 1111 goto free_map_tab; 1112 1113 if (map->ops->map_check_btf) { 1114 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1115 if (ret < 0) 1116 goto free_map_tab; 1117 } 1118 1119 return ret; 1120 free_map_tab: 1121 bpf_map_free_record(map); 1122 return ret; 1123 } 1124 1125 #define BPF_MAP_CREATE_LAST_FIELD map_extra 1126 /* called via syscall */ 1127 static int map_create(union bpf_attr *attr) 1128 { 1129 const struct bpf_map_ops *ops; 1130 int numa_node = bpf_map_attr_numa_node(attr); 1131 u32 map_type = attr->map_type; 1132 struct bpf_map *map; 1133 int f_flags; 1134 int err; 1135 1136 err = CHECK_ATTR(BPF_MAP_CREATE); 1137 if (err) 1138 return -EINVAL; 1139 1140 if (attr->btf_vmlinux_value_type_id) { 1141 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || 1142 attr->btf_key_type_id || attr->btf_value_type_id) 1143 return -EINVAL; 1144 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1145 return -EINVAL; 1146 } 1147 1148 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1149 attr->map_extra != 0) 1150 return -EINVAL; 1151 1152 f_flags = bpf_get_file_flag(attr->map_flags); 1153 if (f_flags < 0) 1154 return f_flags; 1155 1156 if (numa_node != NUMA_NO_NODE && 1157 ((unsigned int)numa_node >= nr_node_ids || 1158 !node_online(numa_node))) 1159 return -EINVAL; 1160 1161 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1162 map_type = attr->map_type; 1163 if (map_type >= ARRAY_SIZE(bpf_map_types)) 1164 return -EINVAL; 1165 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1166 ops = bpf_map_types[map_type]; 1167 if (!ops) 1168 return -EINVAL; 1169 1170 if (ops->map_alloc_check) { 1171 err = ops->map_alloc_check(attr); 1172 if (err) 1173 return err; 1174 } 1175 if (attr->map_ifindex) 1176 ops = &bpf_map_offload_ops; 1177 if (!ops->map_mem_usage) 1178 return -EINVAL; 1179 1180 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1181 * creation for unprivileged users; other actions depend 1182 * on fd availability and access to bpffs, so are dependent on 1183 * object creation success. Even with unprivileged BPF disabled, 1184 * capability checks are still carried out. 1185 */ 1186 if (sysctl_unprivileged_bpf_disabled && !bpf_capable()) 1187 return -EPERM; 1188 1189 /* check privileged map type permissions */ 1190 switch (map_type) { 1191 case BPF_MAP_TYPE_ARRAY: 1192 case BPF_MAP_TYPE_PERCPU_ARRAY: 1193 case BPF_MAP_TYPE_PROG_ARRAY: 1194 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1195 case BPF_MAP_TYPE_CGROUP_ARRAY: 1196 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1197 case BPF_MAP_TYPE_HASH: 1198 case BPF_MAP_TYPE_PERCPU_HASH: 1199 case BPF_MAP_TYPE_HASH_OF_MAPS: 1200 case BPF_MAP_TYPE_RINGBUF: 1201 case BPF_MAP_TYPE_USER_RINGBUF: 1202 case BPF_MAP_TYPE_CGROUP_STORAGE: 1203 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1204 /* unprivileged */ 1205 break; 1206 case BPF_MAP_TYPE_SK_STORAGE: 1207 case BPF_MAP_TYPE_INODE_STORAGE: 1208 case BPF_MAP_TYPE_TASK_STORAGE: 1209 case BPF_MAP_TYPE_CGRP_STORAGE: 1210 case BPF_MAP_TYPE_BLOOM_FILTER: 1211 case BPF_MAP_TYPE_LPM_TRIE: 1212 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1213 case BPF_MAP_TYPE_STACK_TRACE: 1214 case BPF_MAP_TYPE_QUEUE: 1215 case BPF_MAP_TYPE_STACK: 1216 case BPF_MAP_TYPE_LRU_HASH: 1217 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1218 case BPF_MAP_TYPE_STRUCT_OPS: 1219 case BPF_MAP_TYPE_CPUMAP: 1220 if (!bpf_capable()) 1221 return -EPERM; 1222 break; 1223 case BPF_MAP_TYPE_SOCKMAP: 1224 case BPF_MAP_TYPE_SOCKHASH: 1225 case BPF_MAP_TYPE_DEVMAP: 1226 case BPF_MAP_TYPE_DEVMAP_HASH: 1227 case BPF_MAP_TYPE_XSKMAP: 1228 if (!capable(CAP_NET_ADMIN)) 1229 return -EPERM; 1230 break; 1231 default: 1232 WARN(1, "unsupported map type %d", map_type); 1233 return -EPERM; 1234 } 1235 1236 map = ops->map_alloc(attr); 1237 if (IS_ERR(map)) 1238 return PTR_ERR(map); 1239 map->ops = ops; 1240 map->map_type = map_type; 1241 1242 err = bpf_obj_name_cpy(map->name, attr->map_name, 1243 sizeof(attr->map_name)); 1244 if (err < 0) 1245 goto free_map; 1246 1247 atomic64_set(&map->refcnt, 1); 1248 atomic64_set(&map->usercnt, 1); 1249 mutex_init(&map->freeze_mutex); 1250 spin_lock_init(&map->owner.lock); 1251 1252 if (attr->btf_key_type_id || attr->btf_value_type_id || 1253 /* Even the map's value is a kernel's struct, 1254 * the bpf_prog.o must have BTF to begin with 1255 * to figure out the corresponding kernel's 1256 * counter part. Thus, attr->btf_fd has 1257 * to be valid also. 1258 */ 1259 attr->btf_vmlinux_value_type_id) { 1260 struct btf *btf; 1261 1262 btf = btf_get_by_fd(attr->btf_fd); 1263 if (IS_ERR(btf)) { 1264 err = PTR_ERR(btf); 1265 goto free_map; 1266 } 1267 if (btf_is_kernel(btf)) { 1268 btf_put(btf); 1269 err = -EACCES; 1270 goto free_map; 1271 } 1272 map->btf = btf; 1273 1274 if (attr->btf_value_type_id) { 1275 err = map_check_btf(map, btf, attr->btf_key_type_id, 1276 attr->btf_value_type_id); 1277 if (err) 1278 goto free_map; 1279 } 1280 1281 map->btf_key_type_id = attr->btf_key_type_id; 1282 map->btf_value_type_id = attr->btf_value_type_id; 1283 map->btf_vmlinux_value_type_id = 1284 attr->btf_vmlinux_value_type_id; 1285 } 1286 1287 err = security_bpf_map_alloc(map); 1288 if (err) 1289 goto free_map; 1290 1291 err = bpf_map_alloc_id(map); 1292 if (err) 1293 goto free_map_sec; 1294 1295 bpf_map_save_memcg(map); 1296 1297 err = bpf_map_new_fd(map, f_flags); 1298 if (err < 0) { 1299 /* failed to allocate fd. 1300 * bpf_map_put_with_uref() is needed because the above 1301 * bpf_map_alloc_id() has published the map 1302 * to the userspace and the userspace may 1303 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1304 */ 1305 bpf_map_put_with_uref(map); 1306 return err; 1307 } 1308 1309 return err; 1310 1311 free_map_sec: 1312 security_bpf_map_free(map); 1313 free_map: 1314 btf_put(map->btf); 1315 map->ops->map_free(map); 1316 return err; 1317 } 1318 1319 /* if error is returned, fd is released. 1320 * On success caller should complete fd access with matching fdput() 1321 */ 1322 struct bpf_map *__bpf_map_get(struct fd f) 1323 { 1324 if (!f.file) 1325 return ERR_PTR(-EBADF); 1326 if (f.file->f_op != &bpf_map_fops) { 1327 fdput(f); 1328 return ERR_PTR(-EINVAL); 1329 } 1330 1331 return f.file->private_data; 1332 } 1333 1334 void bpf_map_inc(struct bpf_map *map) 1335 { 1336 atomic64_inc(&map->refcnt); 1337 } 1338 EXPORT_SYMBOL_GPL(bpf_map_inc); 1339 1340 void bpf_map_inc_with_uref(struct bpf_map *map) 1341 { 1342 atomic64_inc(&map->refcnt); 1343 atomic64_inc(&map->usercnt); 1344 } 1345 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1346 1347 struct bpf_map *bpf_map_get(u32 ufd) 1348 { 1349 struct fd f = fdget(ufd); 1350 struct bpf_map *map; 1351 1352 map = __bpf_map_get(f); 1353 if (IS_ERR(map)) 1354 return map; 1355 1356 bpf_map_inc(map); 1357 fdput(f); 1358 1359 return map; 1360 } 1361 EXPORT_SYMBOL(bpf_map_get); 1362 1363 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1364 { 1365 struct fd f = fdget(ufd); 1366 struct bpf_map *map; 1367 1368 map = __bpf_map_get(f); 1369 if (IS_ERR(map)) 1370 return map; 1371 1372 bpf_map_inc_with_uref(map); 1373 fdput(f); 1374 1375 return map; 1376 } 1377 1378 /* map_idr_lock should have been held or the map should have been 1379 * protected by rcu read lock. 1380 */ 1381 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1382 { 1383 int refold; 1384 1385 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1386 if (!refold) 1387 return ERR_PTR(-ENOENT); 1388 if (uref) 1389 atomic64_inc(&map->usercnt); 1390 1391 return map; 1392 } 1393 1394 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1395 { 1396 spin_lock_bh(&map_idr_lock); 1397 map = __bpf_map_inc_not_zero(map, false); 1398 spin_unlock_bh(&map_idr_lock); 1399 1400 return map; 1401 } 1402 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1403 1404 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) 1405 { 1406 return -ENOTSUPP; 1407 } 1408 1409 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1410 { 1411 if (key_size) 1412 return vmemdup_user(ukey, key_size); 1413 1414 if (ukey) 1415 return ERR_PTR(-EINVAL); 1416 1417 return NULL; 1418 } 1419 1420 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1421 { 1422 if (key_size) 1423 return kvmemdup_bpfptr(ukey, key_size); 1424 1425 if (!bpfptr_is_null(ukey)) 1426 return ERR_PTR(-EINVAL); 1427 1428 return NULL; 1429 } 1430 1431 /* last field in 'union bpf_attr' used by this command */ 1432 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1433 1434 static int map_lookup_elem(union bpf_attr *attr) 1435 { 1436 void __user *ukey = u64_to_user_ptr(attr->key); 1437 void __user *uvalue = u64_to_user_ptr(attr->value); 1438 int ufd = attr->map_fd; 1439 struct bpf_map *map; 1440 void *key, *value; 1441 u32 value_size; 1442 struct fd f; 1443 int err; 1444 1445 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1446 return -EINVAL; 1447 1448 if (attr->flags & ~BPF_F_LOCK) 1449 return -EINVAL; 1450 1451 f = fdget(ufd); 1452 map = __bpf_map_get(f); 1453 if (IS_ERR(map)) 1454 return PTR_ERR(map); 1455 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1456 err = -EPERM; 1457 goto err_put; 1458 } 1459 1460 if ((attr->flags & BPF_F_LOCK) && 1461 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1462 err = -EINVAL; 1463 goto err_put; 1464 } 1465 1466 key = __bpf_copy_key(ukey, map->key_size); 1467 if (IS_ERR(key)) { 1468 err = PTR_ERR(key); 1469 goto err_put; 1470 } 1471 1472 value_size = bpf_map_value_size(map); 1473 1474 err = -ENOMEM; 1475 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1476 if (!value) 1477 goto free_key; 1478 1479 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1480 if (copy_from_user(value, uvalue, value_size)) 1481 err = -EFAULT; 1482 else 1483 err = bpf_map_copy_value(map, key, value, attr->flags); 1484 goto free_value; 1485 } 1486 1487 err = bpf_map_copy_value(map, key, value, attr->flags); 1488 if (err) 1489 goto free_value; 1490 1491 err = -EFAULT; 1492 if (copy_to_user(uvalue, value, value_size) != 0) 1493 goto free_value; 1494 1495 err = 0; 1496 1497 free_value: 1498 kvfree(value); 1499 free_key: 1500 kvfree(key); 1501 err_put: 1502 fdput(f); 1503 return err; 1504 } 1505 1506 1507 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1508 1509 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1510 { 1511 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1512 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1513 int ufd = attr->map_fd; 1514 struct bpf_map *map; 1515 void *key, *value; 1516 u32 value_size; 1517 struct fd f; 1518 int err; 1519 1520 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1521 return -EINVAL; 1522 1523 f = fdget(ufd); 1524 map = __bpf_map_get(f); 1525 if (IS_ERR(map)) 1526 return PTR_ERR(map); 1527 bpf_map_write_active_inc(map); 1528 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1529 err = -EPERM; 1530 goto err_put; 1531 } 1532 1533 if ((attr->flags & BPF_F_LOCK) && 1534 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1535 err = -EINVAL; 1536 goto err_put; 1537 } 1538 1539 key = ___bpf_copy_key(ukey, map->key_size); 1540 if (IS_ERR(key)) { 1541 err = PTR_ERR(key); 1542 goto err_put; 1543 } 1544 1545 value_size = bpf_map_value_size(map); 1546 value = kvmemdup_bpfptr(uvalue, value_size); 1547 if (IS_ERR(value)) { 1548 err = PTR_ERR(value); 1549 goto free_key; 1550 } 1551 1552 err = bpf_map_update_value(map, f.file, key, value, attr->flags); 1553 1554 kvfree(value); 1555 free_key: 1556 kvfree(key); 1557 err_put: 1558 bpf_map_write_active_dec(map); 1559 fdput(f); 1560 return err; 1561 } 1562 1563 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1564 1565 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1566 { 1567 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1568 int ufd = attr->map_fd; 1569 struct bpf_map *map; 1570 struct fd f; 1571 void *key; 1572 int err; 1573 1574 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1575 return -EINVAL; 1576 1577 f = fdget(ufd); 1578 map = __bpf_map_get(f); 1579 if (IS_ERR(map)) 1580 return PTR_ERR(map); 1581 bpf_map_write_active_inc(map); 1582 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1583 err = -EPERM; 1584 goto err_put; 1585 } 1586 1587 key = ___bpf_copy_key(ukey, map->key_size); 1588 if (IS_ERR(key)) { 1589 err = PTR_ERR(key); 1590 goto err_put; 1591 } 1592 1593 if (bpf_map_is_offloaded(map)) { 1594 err = bpf_map_offload_delete_elem(map, key); 1595 goto out; 1596 } else if (IS_FD_PROG_ARRAY(map) || 1597 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1598 /* These maps require sleepable context */ 1599 err = map->ops->map_delete_elem(map, key); 1600 goto out; 1601 } 1602 1603 bpf_disable_instrumentation(); 1604 rcu_read_lock(); 1605 err = map->ops->map_delete_elem(map, key); 1606 rcu_read_unlock(); 1607 bpf_enable_instrumentation(); 1608 maybe_wait_bpf_programs(map); 1609 out: 1610 kvfree(key); 1611 err_put: 1612 bpf_map_write_active_dec(map); 1613 fdput(f); 1614 return err; 1615 } 1616 1617 /* last field in 'union bpf_attr' used by this command */ 1618 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1619 1620 static int map_get_next_key(union bpf_attr *attr) 1621 { 1622 void __user *ukey = u64_to_user_ptr(attr->key); 1623 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1624 int ufd = attr->map_fd; 1625 struct bpf_map *map; 1626 void *key, *next_key; 1627 struct fd f; 1628 int err; 1629 1630 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1631 return -EINVAL; 1632 1633 f = fdget(ufd); 1634 map = __bpf_map_get(f); 1635 if (IS_ERR(map)) 1636 return PTR_ERR(map); 1637 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1638 err = -EPERM; 1639 goto err_put; 1640 } 1641 1642 if (ukey) { 1643 key = __bpf_copy_key(ukey, map->key_size); 1644 if (IS_ERR(key)) { 1645 err = PTR_ERR(key); 1646 goto err_put; 1647 } 1648 } else { 1649 key = NULL; 1650 } 1651 1652 err = -ENOMEM; 1653 next_key = kvmalloc(map->key_size, GFP_USER); 1654 if (!next_key) 1655 goto free_key; 1656 1657 if (bpf_map_is_offloaded(map)) { 1658 err = bpf_map_offload_get_next_key(map, key, next_key); 1659 goto out; 1660 } 1661 1662 rcu_read_lock(); 1663 err = map->ops->map_get_next_key(map, key, next_key); 1664 rcu_read_unlock(); 1665 out: 1666 if (err) 1667 goto free_next_key; 1668 1669 err = -EFAULT; 1670 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1671 goto free_next_key; 1672 1673 err = 0; 1674 1675 free_next_key: 1676 kvfree(next_key); 1677 free_key: 1678 kvfree(key); 1679 err_put: 1680 fdput(f); 1681 return err; 1682 } 1683 1684 int generic_map_delete_batch(struct bpf_map *map, 1685 const union bpf_attr *attr, 1686 union bpf_attr __user *uattr) 1687 { 1688 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1689 u32 cp, max_count; 1690 int err = 0; 1691 void *key; 1692 1693 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1694 return -EINVAL; 1695 1696 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1697 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1698 return -EINVAL; 1699 } 1700 1701 max_count = attr->batch.count; 1702 if (!max_count) 1703 return 0; 1704 1705 if (put_user(0, &uattr->batch.count)) 1706 return -EFAULT; 1707 1708 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1709 if (!key) 1710 return -ENOMEM; 1711 1712 for (cp = 0; cp < max_count; cp++) { 1713 err = -EFAULT; 1714 if (copy_from_user(key, keys + cp * map->key_size, 1715 map->key_size)) 1716 break; 1717 1718 if (bpf_map_is_offloaded(map)) { 1719 err = bpf_map_offload_delete_elem(map, key); 1720 break; 1721 } 1722 1723 bpf_disable_instrumentation(); 1724 rcu_read_lock(); 1725 err = map->ops->map_delete_elem(map, key); 1726 rcu_read_unlock(); 1727 bpf_enable_instrumentation(); 1728 if (err) 1729 break; 1730 cond_resched(); 1731 } 1732 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1733 err = -EFAULT; 1734 1735 kvfree(key); 1736 1737 maybe_wait_bpf_programs(map); 1738 return err; 1739 } 1740 1741 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 1742 const union bpf_attr *attr, 1743 union bpf_attr __user *uattr) 1744 { 1745 void __user *values = u64_to_user_ptr(attr->batch.values); 1746 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1747 u32 value_size, cp, max_count; 1748 void *key, *value; 1749 int err = 0; 1750 1751 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1752 return -EINVAL; 1753 1754 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1755 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1756 return -EINVAL; 1757 } 1758 1759 value_size = bpf_map_value_size(map); 1760 1761 max_count = attr->batch.count; 1762 if (!max_count) 1763 return 0; 1764 1765 if (put_user(0, &uattr->batch.count)) 1766 return -EFAULT; 1767 1768 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1769 if (!key) 1770 return -ENOMEM; 1771 1772 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1773 if (!value) { 1774 kvfree(key); 1775 return -ENOMEM; 1776 } 1777 1778 for (cp = 0; cp < max_count; cp++) { 1779 err = -EFAULT; 1780 if (copy_from_user(key, keys + cp * map->key_size, 1781 map->key_size) || 1782 copy_from_user(value, values + cp * value_size, value_size)) 1783 break; 1784 1785 err = bpf_map_update_value(map, map_file, key, value, 1786 attr->batch.elem_flags); 1787 1788 if (err) 1789 break; 1790 cond_resched(); 1791 } 1792 1793 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1794 err = -EFAULT; 1795 1796 kvfree(value); 1797 kvfree(key); 1798 return err; 1799 } 1800 1801 #define MAP_LOOKUP_RETRIES 3 1802 1803 int generic_map_lookup_batch(struct bpf_map *map, 1804 const union bpf_attr *attr, 1805 union bpf_attr __user *uattr) 1806 { 1807 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 1808 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 1809 void __user *values = u64_to_user_ptr(attr->batch.values); 1810 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1811 void *buf, *buf_prevkey, *prev_key, *key, *value; 1812 int err, retry = MAP_LOOKUP_RETRIES; 1813 u32 value_size, cp, max_count; 1814 1815 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1816 return -EINVAL; 1817 1818 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1819 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 1820 return -EINVAL; 1821 1822 value_size = bpf_map_value_size(map); 1823 1824 max_count = attr->batch.count; 1825 if (!max_count) 1826 return 0; 1827 1828 if (put_user(0, &uattr->batch.count)) 1829 return -EFAULT; 1830 1831 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1832 if (!buf_prevkey) 1833 return -ENOMEM; 1834 1835 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 1836 if (!buf) { 1837 kvfree(buf_prevkey); 1838 return -ENOMEM; 1839 } 1840 1841 err = -EFAULT; 1842 prev_key = NULL; 1843 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 1844 goto free_buf; 1845 key = buf; 1846 value = key + map->key_size; 1847 if (ubatch) 1848 prev_key = buf_prevkey; 1849 1850 for (cp = 0; cp < max_count;) { 1851 rcu_read_lock(); 1852 err = map->ops->map_get_next_key(map, prev_key, key); 1853 rcu_read_unlock(); 1854 if (err) 1855 break; 1856 err = bpf_map_copy_value(map, key, value, 1857 attr->batch.elem_flags); 1858 1859 if (err == -ENOENT) { 1860 if (retry) { 1861 retry--; 1862 continue; 1863 } 1864 err = -EINTR; 1865 break; 1866 } 1867 1868 if (err) 1869 goto free_buf; 1870 1871 if (copy_to_user(keys + cp * map->key_size, key, 1872 map->key_size)) { 1873 err = -EFAULT; 1874 goto free_buf; 1875 } 1876 if (copy_to_user(values + cp * value_size, value, value_size)) { 1877 err = -EFAULT; 1878 goto free_buf; 1879 } 1880 1881 if (!prev_key) 1882 prev_key = buf_prevkey; 1883 1884 swap(prev_key, key); 1885 retry = MAP_LOOKUP_RETRIES; 1886 cp++; 1887 cond_resched(); 1888 } 1889 1890 if (err == -EFAULT) 1891 goto free_buf; 1892 1893 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 1894 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 1895 err = -EFAULT; 1896 1897 free_buf: 1898 kvfree(buf_prevkey); 1899 kvfree(buf); 1900 return err; 1901 } 1902 1903 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 1904 1905 static int map_lookup_and_delete_elem(union bpf_attr *attr) 1906 { 1907 void __user *ukey = u64_to_user_ptr(attr->key); 1908 void __user *uvalue = u64_to_user_ptr(attr->value); 1909 int ufd = attr->map_fd; 1910 struct bpf_map *map; 1911 void *key, *value; 1912 u32 value_size; 1913 struct fd f; 1914 int err; 1915 1916 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 1917 return -EINVAL; 1918 1919 if (attr->flags & ~BPF_F_LOCK) 1920 return -EINVAL; 1921 1922 f = fdget(ufd); 1923 map = __bpf_map_get(f); 1924 if (IS_ERR(map)) 1925 return PTR_ERR(map); 1926 bpf_map_write_active_inc(map); 1927 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 1928 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1929 err = -EPERM; 1930 goto err_put; 1931 } 1932 1933 if (attr->flags && 1934 (map->map_type == BPF_MAP_TYPE_QUEUE || 1935 map->map_type == BPF_MAP_TYPE_STACK)) { 1936 err = -EINVAL; 1937 goto err_put; 1938 } 1939 1940 if ((attr->flags & BPF_F_LOCK) && 1941 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1942 err = -EINVAL; 1943 goto err_put; 1944 } 1945 1946 key = __bpf_copy_key(ukey, map->key_size); 1947 if (IS_ERR(key)) { 1948 err = PTR_ERR(key); 1949 goto err_put; 1950 } 1951 1952 value_size = bpf_map_value_size(map); 1953 1954 err = -ENOMEM; 1955 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1956 if (!value) 1957 goto free_key; 1958 1959 err = -ENOTSUPP; 1960 if (map->map_type == BPF_MAP_TYPE_QUEUE || 1961 map->map_type == BPF_MAP_TYPE_STACK) { 1962 err = map->ops->map_pop_elem(map, value); 1963 } else if (map->map_type == BPF_MAP_TYPE_HASH || 1964 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 1965 map->map_type == BPF_MAP_TYPE_LRU_HASH || 1966 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 1967 if (!bpf_map_is_offloaded(map)) { 1968 bpf_disable_instrumentation(); 1969 rcu_read_lock(); 1970 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 1971 rcu_read_unlock(); 1972 bpf_enable_instrumentation(); 1973 } 1974 } 1975 1976 if (err) 1977 goto free_value; 1978 1979 if (copy_to_user(uvalue, value, value_size) != 0) { 1980 err = -EFAULT; 1981 goto free_value; 1982 } 1983 1984 err = 0; 1985 1986 free_value: 1987 kvfree(value); 1988 free_key: 1989 kvfree(key); 1990 err_put: 1991 bpf_map_write_active_dec(map); 1992 fdput(f); 1993 return err; 1994 } 1995 1996 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 1997 1998 static int map_freeze(const union bpf_attr *attr) 1999 { 2000 int err = 0, ufd = attr->map_fd; 2001 struct bpf_map *map; 2002 struct fd f; 2003 2004 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2005 return -EINVAL; 2006 2007 f = fdget(ufd); 2008 map = __bpf_map_get(f); 2009 if (IS_ERR(map)) 2010 return PTR_ERR(map); 2011 2012 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) { 2013 fdput(f); 2014 return -ENOTSUPP; 2015 } 2016 2017 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2018 fdput(f); 2019 return -EPERM; 2020 } 2021 2022 mutex_lock(&map->freeze_mutex); 2023 if (bpf_map_write_active(map)) { 2024 err = -EBUSY; 2025 goto err_put; 2026 } 2027 if (READ_ONCE(map->frozen)) { 2028 err = -EBUSY; 2029 goto err_put; 2030 } 2031 2032 WRITE_ONCE(map->frozen, true); 2033 err_put: 2034 mutex_unlock(&map->freeze_mutex); 2035 fdput(f); 2036 return err; 2037 } 2038 2039 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2040 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2041 [_id] = & _name ## _prog_ops, 2042 #define BPF_MAP_TYPE(_id, _ops) 2043 #define BPF_LINK_TYPE(_id, _name) 2044 #include <linux/bpf_types.h> 2045 #undef BPF_PROG_TYPE 2046 #undef BPF_MAP_TYPE 2047 #undef BPF_LINK_TYPE 2048 }; 2049 2050 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2051 { 2052 const struct bpf_prog_ops *ops; 2053 2054 if (type >= ARRAY_SIZE(bpf_prog_types)) 2055 return -EINVAL; 2056 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2057 ops = bpf_prog_types[type]; 2058 if (!ops) 2059 return -EINVAL; 2060 2061 if (!bpf_prog_is_offloaded(prog->aux)) 2062 prog->aux->ops = ops; 2063 else 2064 prog->aux->ops = &bpf_offload_prog_ops; 2065 prog->type = type; 2066 return 0; 2067 } 2068 2069 enum bpf_audit { 2070 BPF_AUDIT_LOAD, 2071 BPF_AUDIT_UNLOAD, 2072 BPF_AUDIT_MAX, 2073 }; 2074 2075 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2076 [BPF_AUDIT_LOAD] = "LOAD", 2077 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2078 }; 2079 2080 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2081 { 2082 struct audit_context *ctx = NULL; 2083 struct audit_buffer *ab; 2084 2085 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2086 return; 2087 if (audit_enabled == AUDIT_OFF) 2088 return; 2089 if (!in_irq() && !irqs_disabled()) 2090 ctx = audit_context(); 2091 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2092 if (unlikely(!ab)) 2093 return; 2094 audit_log_format(ab, "prog-id=%u op=%s", 2095 prog->aux->id, bpf_audit_str[op]); 2096 audit_log_end(ab); 2097 } 2098 2099 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2100 { 2101 int id; 2102 2103 idr_preload(GFP_KERNEL); 2104 spin_lock_bh(&prog_idr_lock); 2105 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2106 if (id > 0) 2107 prog->aux->id = id; 2108 spin_unlock_bh(&prog_idr_lock); 2109 idr_preload_end(); 2110 2111 /* id is in [1, INT_MAX) */ 2112 if (WARN_ON_ONCE(!id)) 2113 return -ENOSPC; 2114 2115 return id > 0 ? 0 : id; 2116 } 2117 2118 void bpf_prog_free_id(struct bpf_prog *prog) 2119 { 2120 unsigned long flags; 2121 2122 /* cBPF to eBPF migrations are currently not in the idr store. 2123 * Offloaded programs are removed from the store when their device 2124 * disappears - even if someone grabs an fd to them they are unusable, 2125 * simply waiting for refcnt to drop to be freed. 2126 */ 2127 if (!prog->aux->id) 2128 return; 2129 2130 spin_lock_irqsave(&prog_idr_lock, flags); 2131 idr_remove(&prog_idr, prog->aux->id); 2132 prog->aux->id = 0; 2133 spin_unlock_irqrestore(&prog_idr_lock, flags); 2134 } 2135 2136 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2137 { 2138 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2139 2140 kvfree(aux->func_info); 2141 kfree(aux->func_info_aux); 2142 free_uid(aux->user); 2143 security_bpf_prog_free(aux); 2144 bpf_prog_free(aux->prog); 2145 } 2146 2147 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2148 { 2149 bpf_prog_kallsyms_del_all(prog); 2150 btf_put(prog->aux->btf); 2151 module_put(prog->aux->mod); 2152 kvfree(prog->aux->jited_linfo); 2153 kvfree(prog->aux->linfo); 2154 kfree(prog->aux->kfunc_tab); 2155 if (prog->aux->attach_btf) 2156 btf_put(prog->aux->attach_btf); 2157 2158 if (deferred) { 2159 if (prog->aux->sleepable) 2160 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2161 else 2162 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2163 } else { 2164 __bpf_prog_put_rcu(&prog->aux->rcu); 2165 } 2166 } 2167 2168 static void bpf_prog_put_deferred(struct work_struct *work) 2169 { 2170 struct bpf_prog_aux *aux; 2171 struct bpf_prog *prog; 2172 2173 aux = container_of(work, struct bpf_prog_aux, work); 2174 prog = aux->prog; 2175 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2176 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2177 bpf_prog_free_id(prog); 2178 __bpf_prog_put_noref(prog, true); 2179 } 2180 2181 static void __bpf_prog_put(struct bpf_prog *prog) 2182 { 2183 struct bpf_prog_aux *aux = prog->aux; 2184 2185 if (atomic64_dec_and_test(&aux->refcnt)) { 2186 if (in_irq() || irqs_disabled()) { 2187 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2188 schedule_work(&aux->work); 2189 } else { 2190 bpf_prog_put_deferred(&aux->work); 2191 } 2192 } 2193 } 2194 2195 void bpf_prog_put(struct bpf_prog *prog) 2196 { 2197 __bpf_prog_put(prog); 2198 } 2199 EXPORT_SYMBOL_GPL(bpf_prog_put); 2200 2201 static int bpf_prog_release(struct inode *inode, struct file *filp) 2202 { 2203 struct bpf_prog *prog = filp->private_data; 2204 2205 bpf_prog_put(prog); 2206 return 0; 2207 } 2208 2209 struct bpf_prog_kstats { 2210 u64 nsecs; 2211 u64 cnt; 2212 u64 misses; 2213 }; 2214 2215 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2216 { 2217 struct bpf_prog_stats *stats; 2218 unsigned int flags; 2219 2220 stats = this_cpu_ptr(prog->stats); 2221 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2222 u64_stats_inc(&stats->misses); 2223 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2224 } 2225 2226 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2227 struct bpf_prog_kstats *stats) 2228 { 2229 u64 nsecs = 0, cnt = 0, misses = 0; 2230 int cpu; 2231 2232 for_each_possible_cpu(cpu) { 2233 const struct bpf_prog_stats *st; 2234 unsigned int start; 2235 u64 tnsecs, tcnt, tmisses; 2236 2237 st = per_cpu_ptr(prog->stats, cpu); 2238 do { 2239 start = u64_stats_fetch_begin(&st->syncp); 2240 tnsecs = u64_stats_read(&st->nsecs); 2241 tcnt = u64_stats_read(&st->cnt); 2242 tmisses = u64_stats_read(&st->misses); 2243 } while (u64_stats_fetch_retry(&st->syncp, start)); 2244 nsecs += tnsecs; 2245 cnt += tcnt; 2246 misses += tmisses; 2247 } 2248 stats->nsecs = nsecs; 2249 stats->cnt = cnt; 2250 stats->misses = misses; 2251 } 2252 2253 #ifdef CONFIG_PROC_FS 2254 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2255 { 2256 const struct bpf_prog *prog = filp->private_data; 2257 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2258 struct bpf_prog_kstats stats; 2259 2260 bpf_prog_get_stats(prog, &stats); 2261 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2262 seq_printf(m, 2263 "prog_type:\t%u\n" 2264 "prog_jited:\t%u\n" 2265 "prog_tag:\t%s\n" 2266 "memlock:\t%llu\n" 2267 "prog_id:\t%u\n" 2268 "run_time_ns:\t%llu\n" 2269 "run_cnt:\t%llu\n" 2270 "recursion_misses:\t%llu\n" 2271 "verified_insns:\t%u\n", 2272 prog->type, 2273 prog->jited, 2274 prog_tag, 2275 prog->pages * 1ULL << PAGE_SHIFT, 2276 prog->aux->id, 2277 stats.nsecs, 2278 stats.cnt, 2279 stats.misses, 2280 prog->aux->verified_insns); 2281 } 2282 #endif 2283 2284 const struct file_operations bpf_prog_fops = { 2285 #ifdef CONFIG_PROC_FS 2286 .show_fdinfo = bpf_prog_show_fdinfo, 2287 #endif 2288 .release = bpf_prog_release, 2289 .read = bpf_dummy_read, 2290 .write = bpf_dummy_write, 2291 }; 2292 2293 int bpf_prog_new_fd(struct bpf_prog *prog) 2294 { 2295 int ret; 2296 2297 ret = security_bpf_prog(prog); 2298 if (ret < 0) 2299 return ret; 2300 2301 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2302 O_RDWR | O_CLOEXEC); 2303 } 2304 2305 static struct bpf_prog *____bpf_prog_get(struct fd f) 2306 { 2307 if (!f.file) 2308 return ERR_PTR(-EBADF); 2309 if (f.file->f_op != &bpf_prog_fops) { 2310 fdput(f); 2311 return ERR_PTR(-EINVAL); 2312 } 2313 2314 return f.file->private_data; 2315 } 2316 2317 void bpf_prog_add(struct bpf_prog *prog, int i) 2318 { 2319 atomic64_add(i, &prog->aux->refcnt); 2320 } 2321 EXPORT_SYMBOL_GPL(bpf_prog_add); 2322 2323 void bpf_prog_sub(struct bpf_prog *prog, int i) 2324 { 2325 /* Only to be used for undoing previous bpf_prog_add() in some 2326 * error path. We still know that another entity in our call 2327 * path holds a reference to the program, thus atomic_sub() can 2328 * be safely used in such cases! 2329 */ 2330 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2331 } 2332 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2333 2334 void bpf_prog_inc(struct bpf_prog *prog) 2335 { 2336 atomic64_inc(&prog->aux->refcnt); 2337 } 2338 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2339 2340 /* prog_idr_lock should have been held */ 2341 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2342 { 2343 int refold; 2344 2345 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2346 2347 if (!refold) 2348 return ERR_PTR(-ENOENT); 2349 2350 return prog; 2351 } 2352 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2353 2354 bool bpf_prog_get_ok(struct bpf_prog *prog, 2355 enum bpf_prog_type *attach_type, bool attach_drv) 2356 { 2357 /* not an attachment, just a refcount inc, always allow */ 2358 if (!attach_type) 2359 return true; 2360 2361 if (prog->type != *attach_type) 2362 return false; 2363 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2364 return false; 2365 2366 return true; 2367 } 2368 2369 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2370 bool attach_drv) 2371 { 2372 struct fd f = fdget(ufd); 2373 struct bpf_prog *prog; 2374 2375 prog = ____bpf_prog_get(f); 2376 if (IS_ERR(prog)) 2377 return prog; 2378 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) { 2379 prog = ERR_PTR(-EINVAL); 2380 goto out; 2381 } 2382 2383 bpf_prog_inc(prog); 2384 out: 2385 fdput(f); 2386 return prog; 2387 } 2388 2389 struct bpf_prog *bpf_prog_get(u32 ufd) 2390 { 2391 return __bpf_prog_get(ufd, NULL, false); 2392 } 2393 2394 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2395 bool attach_drv) 2396 { 2397 return __bpf_prog_get(ufd, &type, attach_drv); 2398 } 2399 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2400 2401 /* Initially all BPF programs could be loaded w/o specifying 2402 * expected_attach_type. Later for some of them specifying expected_attach_type 2403 * at load time became required so that program could be validated properly. 2404 * Programs of types that are allowed to be loaded both w/ and w/o (for 2405 * backward compatibility) expected_attach_type, should have the default attach 2406 * type assigned to expected_attach_type for the latter case, so that it can be 2407 * validated later at attach time. 2408 * 2409 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2410 * prog type requires it but has some attach types that have to be backward 2411 * compatible. 2412 */ 2413 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2414 { 2415 switch (attr->prog_type) { 2416 case BPF_PROG_TYPE_CGROUP_SOCK: 2417 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2418 * exist so checking for non-zero is the way to go here. 2419 */ 2420 if (!attr->expected_attach_type) 2421 attr->expected_attach_type = 2422 BPF_CGROUP_INET_SOCK_CREATE; 2423 break; 2424 case BPF_PROG_TYPE_SK_REUSEPORT: 2425 if (!attr->expected_attach_type) 2426 attr->expected_attach_type = 2427 BPF_SK_REUSEPORT_SELECT; 2428 break; 2429 } 2430 } 2431 2432 static int 2433 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2434 enum bpf_attach_type expected_attach_type, 2435 struct btf *attach_btf, u32 btf_id, 2436 struct bpf_prog *dst_prog) 2437 { 2438 if (btf_id) { 2439 if (btf_id > BTF_MAX_TYPE) 2440 return -EINVAL; 2441 2442 if (!attach_btf && !dst_prog) 2443 return -EINVAL; 2444 2445 switch (prog_type) { 2446 case BPF_PROG_TYPE_TRACING: 2447 case BPF_PROG_TYPE_LSM: 2448 case BPF_PROG_TYPE_STRUCT_OPS: 2449 case BPF_PROG_TYPE_EXT: 2450 break; 2451 default: 2452 return -EINVAL; 2453 } 2454 } 2455 2456 if (attach_btf && (!btf_id || dst_prog)) 2457 return -EINVAL; 2458 2459 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2460 prog_type != BPF_PROG_TYPE_EXT) 2461 return -EINVAL; 2462 2463 switch (prog_type) { 2464 case BPF_PROG_TYPE_CGROUP_SOCK: 2465 switch (expected_attach_type) { 2466 case BPF_CGROUP_INET_SOCK_CREATE: 2467 case BPF_CGROUP_INET_SOCK_RELEASE: 2468 case BPF_CGROUP_INET4_POST_BIND: 2469 case BPF_CGROUP_INET6_POST_BIND: 2470 return 0; 2471 default: 2472 return -EINVAL; 2473 } 2474 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2475 switch (expected_attach_type) { 2476 case BPF_CGROUP_INET4_BIND: 2477 case BPF_CGROUP_INET6_BIND: 2478 case BPF_CGROUP_INET4_CONNECT: 2479 case BPF_CGROUP_INET6_CONNECT: 2480 case BPF_CGROUP_INET4_GETPEERNAME: 2481 case BPF_CGROUP_INET6_GETPEERNAME: 2482 case BPF_CGROUP_INET4_GETSOCKNAME: 2483 case BPF_CGROUP_INET6_GETSOCKNAME: 2484 case BPF_CGROUP_UDP4_SENDMSG: 2485 case BPF_CGROUP_UDP6_SENDMSG: 2486 case BPF_CGROUP_UDP4_RECVMSG: 2487 case BPF_CGROUP_UDP6_RECVMSG: 2488 return 0; 2489 default: 2490 return -EINVAL; 2491 } 2492 case BPF_PROG_TYPE_CGROUP_SKB: 2493 switch (expected_attach_type) { 2494 case BPF_CGROUP_INET_INGRESS: 2495 case BPF_CGROUP_INET_EGRESS: 2496 return 0; 2497 default: 2498 return -EINVAL; 2499 } 2500 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2501 switch (expected_attach_type) { 2502 case BPF_CGROUP_SETSOCKOPT: 2503 case BPF_CGROUP_GETSOCKOPT: 2504 return 0; 2505 default: 2506 return -EINVAL; 2507 } 2508 case BPF_PROG_TYPE_SK_LOOKUP: 2509 if (expected_attach_type == BPF_SK_LOOKUP) 2510 return 0; 2511 return -EINVAL; 2512 case BPF_PROG_TYPE_SK_REUSEPORT: 2513 switch (expected_attach_type) { 2514 case BPF_SK_REUSEPORT_SELECT: 2515 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2516 return 0; 2517 default: 2518 return -EINVAL; 2519 } 2520 case BPF_PROG_TYPE_NETFILTER: 2521 if (expected_attach_type == BPF_NETFILTER) 2522 return 0; 2523 return -EINVAL; 2524 case BPF_PROG_TYPE_SYSCALL: 2525 case BPF_PROG_TYPE_EXT: 2526 if (expected_attach_type) 2527 return -EINVAL; 2528 fallthrough; 2529 default: 2530 return 0; 2531 } 2532 } 2533 2534 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2535 { 2536 switch (prog_type) { 2537 case BPF_PROG_TYPE_SCHED_CLS: 2538 case BPF_PROG_TYPE_SCHED_ACT: 2539 case BPF_PROG_TYPE_XDP: 2540 case BPF_PROG_TYPE_LWT_IN: 2541 case BPF_PROG_TYPE_LWT_OUT: 2542 case BPF_PROG_TYPE_LWT_XMIT: 2543 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2544 case BPF_PROG_TYPE_SK_SKB: 2545 case BPF_PROG_TYPE_SK_MSG: 2546 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2547 case BPF_PROG_TYPE_CGROUP_DEVICE: 2548 case BPF_PROG_TYPE_CGROUP_SOCK: 2549 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2550 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2551 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2552 case BPF_PROG_TYPE_SOCK_OPS: 2553 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2554 case BPF_PROG_TYPE_NETFILTER: 2555 return true; 2556 case BPF_PROG_TYPE_CGROUP_SKB: 2557 /* always unpriv */ 2558 case BPF_PROG_TYPE_SK_REUSEPORT: 2559 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2560 default: 2561 return false; 2562 } 2563 } 2564 2565 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2566 { 2567 switch (prog_type) { 2568 case BPF_PROG_TYPE_KPROBE: 2569 case BPF_PROG_TYPE_TRACEPOINT: 2570 case BPF_PROG_TYPE_PERF_EVENT: 2571 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2572 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2573 case BPF_PROG_TYPE_TRACING: 2574 case BPF_PROG_TYPE_LSM: 2575 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2576 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2577 return true; 2578 default: 2579 return false; 2580 } 2581 } 2582 2583 /* last field in 'union bpf_attr' used by this command */ 2584 #define BPF_PROG_LOAD_LAST_FIELD log_true_size 2585 2586 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) 2587 { 2588 enum bpf_prog_type type = attr->prog_type; 2589 struct bpf_prog *prog, *dst_prog = NULL; 2590 struct btf *attach_btf = NULL; 2591 int err; 2592 char license[128]; 2593 2594 if (CHECK_ATTR(BPF_PROG_LOAD)) 2595 return -EINVAL; 2596 2597 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2598 BPF_F_ANY_ALIGNMENT | 2599 BPF_F_TEST_STATE_FREQ | 2600 BPF_F_SLEEPABLE | 2601 BPF_F_TEST_RND_HI32 | 2602 BPF_F_XDP_HAS_FRAGS | 2603 BPF_F_XDP_DEV_BOUND_ONLY)) 2604 return -EINVAL; 2605 2606 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2607 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2608 !bpf_capable()) 2609 return -EPERM; 2610 2611 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2612 * creation for unprivileged users; other actions depend 2613 * on fd availability and access to bpffs, so are dependent on 2614 * object creation success. Even with unprivileged BPF disabled, 2615 * capability checks are still carried out for these 2616 * and other operations. 2617 */ 2618 if (sysctl_unprivileged_bpf_disabled && !bpf_capable()) 2619 return -EPERM; 2620 2621 if (attr->insn_cnt == 0 || 2622 attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) 2623 return -E2BIG; 2624 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2625 type != BPF_PROG_TYPE_CGROUP_SKB && 2626 !bpf_capable()) 2627 return -EPERM; 2628 2629 if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN)) 2630 return -EPERM; 2631 if (is_perfmon_prog_type(type) && !perfmon_capable()) 2632 return -EPERM; 2633 2634 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 2635 * or btf, we need to check which one it is 2636 */ 2637 if (attr->attach_prog_fd) { 2638 dst_prog = bpf_prog_get(attr->attach_prog_fd); 2639 if (IS_ERR(dst_prog)) { 2640 dst_prog = NULL; 2641 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 2642 if (IS_ERR(attach_btf)) 2643 return -EINVAL; 2644 if (!btf_is_kernel(attach_btf)) { 2645 /* attaching through specifying bpf_prog's BTF 2646 * objects directly might be supported eventually 2647 */ 2648 btf_put(attach_btf); 2649 return -ENOTSUPP; 2650 } 2651 } 2652 } else if (attr->attach_btf_id) { 2653 /* fall back to vmlinux BTF, if BTF type ID is specified */ 2654 attach_btf = bpf_get_btf_vmlinux(); 2655 if (IS_ERR(attach_btf)) 2656 return PTR_ERR(attach_btf); 2657 if (!attach_btf) 2658 return -EINVAL; 2659 btf_get(attach_btf); 2660 } 2661 2662 bpf_prog_load_fixup_attach_type(attr); 2663 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 2664 attach_btf, attr->attach_btf_id, 2665 dst_prog)) { 2666 if (dst_prog) 2667 bpf_prog_put(dst_prog); 2668 if (attach_btf) 2669 btf_put(attach_btf); 2670 return -EINVAL; 2671 } 2672 2673 /* plain bpf_prog allocation */ 2674 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 2675 if (!prog) { 2676 if (dst_prog) 2677 bpf_prog_put(dst_prog); 2678 if (attach_btf) 2679 btf_put(attach_btf); 2680 return -ENOMEM; 2681 } 2682 2683 prog->expected_attach_type = attr->expected_attach_type; 2684 prog->aux->attach_btf = attach_btf; 2685 prog->aux->attach_btf_id = attr->attach_btf_id; 2686 prog->aux->dst_prog = dst_prog; 2687 prog->aux->dev_bound = !!attr->prog_ifindex; 2688 prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE; 2689 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 2690 2691 err = security_bpf_prog_alloc(prog->aux); 2692 if (err) 2693 goto free_prog; 2694 2695 prog->aux->user = get_current_user(); 2696 prog->len = attr->insn_cnt; 2697 2698 err = -EFAULT; 2699 if (copy_from_bpfptr(prog->insns, 2700 make_bpfptr(attr->insns, uattr.is_kernel), 2701 bpf_prog_insn_size(prog)) != 0) 2702 goto free_prog_sec; 2703 /* copy eBPF program license from user space */ 2704 if (strncpy_from_bpfptr(license, 2705 make_bpfptr(attr->license, uattr.is_kernel), 2706 sizeof(license) - 1) < 0) 2707 goto free_prog_sec; 2708 license[sizeof(license) - 1] = 0; 2709 2710 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 2711 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 2712 2713 prog->orig_prog = NULL; 2714 prog->jited = 0; 2715 2716 atomic64_set(&prog->aux->refcnt, 1); 2717 2718 if (bpf_prog_is_dev_bound(prog->aux)) { 2719 err = bpf_prog_dev_bound_init(prog, attr); 2720 if (err) 2721 goto free_prog_sec; 2722 } 2723 2724 if (type == BPF_PROG_TYPE_EXT && dst_prog && 2725 bpf_prog_is_dev_bound(dst_prog->aux)) { 2726 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 2727 if (err) 2728 goto free_prog_sec; 2729 } 2730 2731 /* find program type: socket_filter vs tracing_filter */ 2732 err = find_prog_type(type, prog); 2733 if (err < 0) 2734 goto free_prog_sec; 2735 2736 prog->aux->load_time = ktime_get_boottime_ns(); 2737 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 2738 sizeof(attr->prog_name)); 2739 if (err < 0) 2740 goto free_prog_sec; 2741 2742 /* run eBPF verifier */ 2743 err = bpf_check(&prog, attr, uattr, uattr_size); 2744 if (err < 0) 2745 goto free_used_maps; 2746 2747 prog = bpf_prog_select_runtime(prog, &err); 2748 if (err < 0) 2749 goto free_used_maps; 2750 2751 err = bpf_prog_alloc_id(prog); 2752 if (err) 2753 goto free_used_maps; 2754 2755 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 2756 * effectively publicly exposed. However, retrieving via 2757 * bpf_prog_get_fd_by_id() will take another reference, 2758 * therefore it cannot be gone underneath us. 2759 * 2760 * Only for the time /after/ successful bpf_prog_new_fd() 2761 * and before returning to userspace, we might just hold 2762 * one reference and any parallel close on that fd could 2763 * rip everything out. Hence, below notifications must 2764 * happen before bpf_prog_new_fd(). 2765 * 2766 * Also, any failure handling from this point onwards must 2767 * be using bpf_prog_put() given the program is exposed. 2768 */ 2769 bpf_prog_kallsyms_add(prog); 2770 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 2771 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 2772 2773 err = bpf_prog_new_fd(prog); 2774 if (err < 0) 2775 bpf_prog_put(prog); 2776 return err; 2777 2778 free_used_maps: 2779 /* In case we have subprogs, we need to wait for a grace 2780 * period before we can tear down JIT memory since symbols 2781 * are already exposed under kallsyms. 2782 */ 2783 __bpf_prog_put_noref(prog, prog->aux->func_cnt); 2784 return err; 2785 free_prog_sec: 2786 free_uid(prog->aux->user); 2787 security_bpf_prog_free(prog->aux); 2788 free_prog: 2789 if (prog->aux->attach_btf) 2790 btf_put(prog->aux->attach_btf); 2791 bpf_prog_free(prog); 2792 return err; 2793 } 2794 2795 #define BPF_OBJ_LAST_FIELD path_fd 2796 2797 static int bpf_obj_pin(const union bpf_attr *attr) 2798 { 2799 int path_fd; 2800 2801 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 2802 return -EINVAL; 2803 2804 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 2805 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 2806 return -EINVAL; 2807 2808 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 2809 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 2810 u64_to_user_ptr(attr->pathname)); 2811 } 2812 2813 static int bpf_obj_get(const union bpf_attr *attr) 2814 { 2815 int path_fd; 2816 2817 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 2818 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 2819 return -EINVAL; 2820 2821 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 2822 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 2823 return -EINVAL; 2824 2825 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 2826 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 2827 attr->file_flags); 2828 } 2829 2830 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 2831 const struct bpf_link_ops *ops, struct bpf_prog *prog) 2832 { 2833 WARN_ON(ops->dealloc && ops->dealloc_deferred); 2834 atomic64_set(&link->refcnt, 1); 2835 link->type = type; 2836 link->id = 0; 2837 link->ops = ops; 2838 link->prog = prog; 2839 } 2840 2841 static void bpf_link_free_id(int id) 2842 { 2843 if (!id) 2844 return; 2845 2846 spin_lock_bh(&link_idr_lock); 2847 idr_remove(&link_idr, id); 2848 spin_unlock_bh(&link_idr_lock); 2849 } 2850 2851 /* Clean up bpf_link and corresponding anon_inode file and FD. After 2852 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 2853 * anon_inode's release() call. This helper marks bpf_link as 2854 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 2855 * is not decremented, it's the responsibility of a calling code that failed 2856 * to complete bpf_link initialization. 2857 * This helper eventually calls link's dealloc callback, but does not call 2858 * link's release callback. 2859 */ 2860 void bpf_link_cleanup(struct bpf_link_primer *primer) 2861 { 2862 primer->link->prog = NULL; 2863 bpf_link_free_id(primer->id); 2864 fput(primer->file); 2865 put_unused_fd(primer->fd); 2866 } 2867 2868 void bpf_link_inc(struct bpf_link *link) 2869 { 2870 atomic64_inc(&link->refcnt); 2871 } 2872 2873 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 2874 { 2875 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 2876 2877 /* free bpf_link and its containing memory */ 2878 link->ops->dealloc_deferred(link); 2879 } 2880 2881 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu) 2882 { 2883 if (rcu_trace_implies_rcu_gp()) 2884 bpf_link_defer_dealloc_rcu_gp(rcu); 2885 else 2886 call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp); 2887 } 2888 2889 /* bpf_link_free is guaranteed to be called from process context */ 2890 static void bpf_link_free(struct bpf_link *link) 2891 { 2892 const struct bpf_link_ops *ops = link->ops; 2893 bool sleepable = false; 2894 2895 bpf_link_free_id(link->id); 2896 if (link->prog) { 2897 sleepable = link->prog->aux->sleepable; 2898 /* detach BPF program, clean up used resources */ 2899 ops->release(link); 2900 bpf_prog_put(link->prog); 2901 } 2902 if (ops->dealloc_deferred) { 2903 /* schedule BPF link deallocation; if underlying BPF program 2904 * is sleepable, we need to first wait for RCU tasks trace 2905 * sync, then go through "classic" RCU grace period 2906 */ 2907 if (sleepable) 2908 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp); 2909 else 2910 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 2911 } else if (ops->dealloc) 2912 ops->dealloc(link); 2913 } 2914 2915 static void bpf_link_put_deferred(struct work_struct *work) 2916 { 2917 struct bpf_link *link = container_of(work, struct bpf_link, work); 2918 2919 bpf_link_free(link); 2920 } 2921 2922 /* bpf_link_put might be called from atomic context. It needs to be called 2923 * from sleepable context in order to acquire sleeping locks during the process. 2924 */ 2925 void bpf_link_put(struct bpf_link *link) 2926 { 2927 if (!atomic64_dec_and_test(&link->refcnt)) 2928 return; 2929 2930 INIT_WORK(&link->work, bpf_link_put_deferred); 2931 schedule_work(&link->work); 2932 } 2933 EXPORT_SYMBOL(bpf_link_put); 2934 2935 static void bpf_link_put_direct(struct bpf_link *link) 2936 { 2937 if (!atomic64_dec_and_test(&link->refcnt)) 2938 return; 2939 bpf_link_free(link); 2940 } 2941 2942 static int bpf_link_release(struct inode *inode, struct file *filp) 2943 { 2944 struct bpf_link *link = filp->private_data; 2945 2946 bpf_link_put_direct(link); 2947 return 0; 2948 } 2949 2950 #ifdef CONFIG_PROC_FS 2951 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 2952 #define BPF_MAP_TYPE(_id, _ops) 2953 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 2954 static const char *bpf_link_type_strs[] = { 2955 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 2956 #include <linux/bpf_types.h> 2957 }; 2958 #undef BPF_PROG_TYPE 2959 #undef BPF_MAP_TYPE 2960 #undef BPF_LINK_TYPE 2961 2962 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 2963 { 2964 const struct bpf_link *link = filp->private_data; 2965 const struct bpf_prog *prog = link->prog; 2966 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2967 2968 seq_printf(m, 2969 "link_type:\t%s\n" 2970 "link_id:\t%u\n", 2971 bpf_link_type_strs[link->type], 2972 link->id); 2973 if (prog) { 2974 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2975 seq_printf(m, 2976 "prog_tag:\t%s\n" 2977 "prog_id:\t%u\n", 2978 prog_tag, 2979 prog->aux->id); 2980 } 2981 if (link->ops->show_fdinfo) 2982 link->ops->show_fdinfo(link, m); 2983 } 2984 #endif 2985 2986 static const struct file_operations bpf_link_fops = { 2987 #ifdef CONFIG_PROC_FS 2988 .show_fdinfo = bpf_link_show_fdinfo, 2989 #endif 2990 .release = bpf_link_release, 2991 .read = bpf_dummy_read, 2992 .write = bpf_dummy_write, 2993 }; 2994 2995 static int bpf_link_alloc_id(struct bpf_link *link) 2996 { 2997 int id; 2998 2999 idr_preload(GFP_KERNEL); 3000 spin_lock_bh(&link_idr_lock); 3001 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3002 spin_unlock_bh(&link_idr_lock); 3003 idr_preload_end(); 3004 3005 return id; 3006 } 3007 3008 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3009 * reserving unused FD and allocating ID from link_idr. This is to be paired 3010 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3011 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3012 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3013 * transient state is passed around in struct bpf_link_primer. 3014 * This is preferred way to create and initialize bpf_link, especially when 3015 * there are complicated and expensive operations in between creating bpf_link 3016 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3017 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3018 * expensive (and potentially failing) roll back operations in a rare case 3019 * that file, FD, or ID can't be allocated. 3020 */ 3021 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3022 { 3023 struct file *file; 3024 int fd, id; 3025 3026 fd = get_unused_fd_flags(O_CLOEXEC); 3027 if (fd < 0) 3028 return fd; 3029 3030 3031 id = bpf_link_alloc_id(link); 3032 if (id < 0) { 3033 put_unused_fd(fd); 3034 return id; 3035 } 3036 3037 file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC); 3038 if (IS_ERR(file)) { 3039 bpf_link_free_id(id); 3040 put_unused_fd(fd); 3041 return PTR_ERR(file); 3042 } 3043 3044 primer->link = link; 3045 primer->file = file; 3046 primer->fd = fd; 3047 primer->id = id; 3048 return 0; 3049 } 3050 3051 int bpf_link_settle(struct bpf_link_primer *primer) 3052 { 3053 /* make bpf_link fetchable by ID */ 3054 spin_lock_bh(&link_idr_lock); 3055 primer->link->id = primer->id; 3056 spin_unlock_bh(&link_idr_lock); 3057 /* make bpf_link fetchable by FD */ 3058 fd_install(primer->fd, primer->file); 3059 /* pass through installed FD */ 3060 return primer->fd; 3061 } 3062 3063 int bpf_link_new_fd(struct bpf_link *link) 3064 { 3065 return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC); 3066 } 3067 3068 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3069 { 3070 struct fd f = fdget(ufd); 3071 struct bpf_link *link; 3072 3073 if (!f.file) 3074 return ERR_PTR(-EBADF); 3075 if (f.file->f_op != &bpf_link_fops) { 3076 fdput(f); 3077 return ERR_PTR(-EINVAL); 3078 } 3079 3080 link = f.file->private_data; 3081 bpf_link_inc(link); 3082 fdput(f); 3083 3084 return link; 3085 } 3086 EXPORT_SYMBOL(bpf_link_get_from_fd); 3087 3088 static void bpf_tracing_link_release(struct bpf_link *link) 3089 { 3090 struct bpf_tracing_link *tr_link = 3091 container_of(link, struct bpf_tracing_link, link.link); 3092 3093 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3094 tr_link->trampoline)); 3095 3096 bpf_trampoline_put(tr_link->trampoline); 3097 3098 /* tgt_prog is NULL if target is a kernel function */ 3099 if (tr_link->tgt_prog) 3100 bpf_prog_put(tr_link->tgt_prog); 3101 } 3102 3103 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3104 { 3105 struct bpf_tracing_link *tr_link = 3106 container_of(link, struct bpf_tracing_link, link.link); 3107 3108 kfree(tr_link); 3109 } 3110 3111 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3112 struct seq_file *seq) 3113 { 3114 struct bpf_tracing_link *tr_link = 3115 container_of(link, struct bpf_tracing_link, link.link); 3116 u32 target_btf_id, target_obj_id; 3117 3118 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3119 &target_obj_id, &target_btf_id); 3120 seq_printf(seq, 3121 "attach_type:\t%d\n" 3122 "target_obj_id:\t%u\n" 3123 "target_btf_id:\t%u\n", 3124 tr_link->attach_type, 3125 target_obj_id, 3126 target_btf_id); 3127 } 3128 3129 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3130 struct bpf_link_info *info) 3131 { 3132 struct bpf_tracing_link *tr_link = 3133 container_of(link, struct bpf_tracing_link, link.link); 3134 3135 info->tracing.attach_type = tr_link->attach_type; 3136 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3137 &info->tracing.target_obj_id, 3138 &info->tracing.target_btf_id); 3139 3140 return 0; 3141 } 3142 3143 static const struct bpf_link_ops bpf_tracing_link_lops = { 3144 .release = bpf_tracing_link_release, 3145 .dealloc = bpf_tracing_link_dealloc, 3146 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3147 .fill_link_info = bpf_tracing_link_fill_link_info, 3148 }; 3149 3150 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3151 int tgt_prog_fd, 3152 u32 btf_id, 3153 u64 bpf_cookie) 3154 { 3155 struct bpf_link_primer link_primer; 3156 struct bpf_prog *tgt_prog = NULL; 3157 struct bpf_trampoline *tr = NULL; 3158 struct bpf_tracing_link *link; 3159 u64 key = 0; 3160 int err; 3161 3162 switch (prog->type) { 3163 case BPF_PROG_TYPE_TRACING: 3164 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3165 prog->expected_attach_type != BPF_TRACE_FEXIT && 3166 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3167 err = -EINVAL; 3168 goto out_put_prog; 3169 } 3170 break; 3171 case BPF_PROG_TYPE_EXT: 3172 if (prog->expected_attach_type != 0) { 3173 err = -EINVAL; 3174 goto out_put_prog; 3175 } 3176 break; 3177 case BPF_PROG_TYPE_LSM: 3178 if (prog->expected_attach_type != BPF_LSM_MAC) { 3179 err = -EINVAL; 3180 goto out_put_prog; 3181 } 3182 break; 3183 default: 3184 err = -EINVAL; 3185 goto out_put_prog; 3186 } 3187 3188 if (!!tgt_prog_fd != !!btf_id) { 3189 err = -EINVAL; 3190 goto out_put_prog; 3191 } 3192 3193 if (tgt_prog_fd) { 3194 /* For now we only allow new targets for BPF_PROG_TYPE_EXT */ 3195 if (prog->type != BPF_PROG_TYPE_EXT) { 3196 err = -EINVAL; 3197 goto out_put_prog; 3198 } 3199 3200 tgt_prog = bpf_prog_get(tgt_prog_fd); 3201 if (IS_ERR(tgt_prog)) { 3202 err = PTR_ERR(tgt_prog); 3203 tgt_prog = NULL; 3204 goto out_put_prog; 3205 } 3206 3207 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3208 } 3209 3210 link = kzalloc(sizeof(*link), GFP_USER); 3211 if (!link) { 3212 err = -ENOMEM; 3213 goto out_put_prog; 3214 } 3215 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3216 &bpf_tracing_link_lops, prog); 3217 link->attach_type = prog->expected_attach_type; 3218 link->link.cookie = bpf_cookie; 3219 3220 mutex_lock(&prog->aux->dst_mutex); 3221 3222 /* There are a few possible cases here: 3223 * 3224 * - if prog->aux->dst_trampoline is set, the program was just loaded 3225 * and not yet attached to anything, so we can use the values stored 3226 * in prog->aux 3227 * 3228 * - if prog->aux->dst_trampoline is NULL, the program has already been 3229 * attached to a target and its initial target was cleared (below) 3230 * 3231 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3232 * target_btf_id using the link_create API. 3233 * 3234 * - if tgt_prog == NULL when this function was called using the old 3235 * raw_tracepoint_open API, and we need a target from prog->aux 3236 * 3237 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3238 * was detached and is going for re-attachment. 3239 * 3240 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3241 * are NULL, then program was already attached and user did not provide 3242 * tgt_prog_fd so we have no way to find out or create trampoline 3243 */ 3244 if (!prog->aux->dst_trampoline && !tgt_prog) { 3245 /* 3246 * Allow re-attach for TRACING and LSM programs. If it's 3247 * currently linked, bpf_trampoline_link_prog will fail. 3248 * EXT programs need to specify tgt_prog_fd, so they 3249 * re-attach in separate code path. 3250 */ 3251 if (prog->type != BPF_PROG_TYPE_TRACING && 3252 prog->type != BPF_PROG_TYPE_LSM) { 3253 err = -EINVAL; 3254 goto out_unlock; 3255 } 3256 /* We can allow re-attach only if we have valid attach_btf. */ 3257 if (!prog->aux->attach_btf) { 3258 err = -EINVAL; 3259 goto out_unlock; 3260 } 3261 btf_id = prog->aux->attach_btf_id; 3262 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3263 } 3264 3265 if (!prog->aux->dst_trampoline || 3266 (key && key != prog->aux->dst_trampoline->key)) { 3267 /* If there is no saved target, or the specified target is 3268 * different from the destination specified at load time, we 3269 * need a new trampoline and a check for compatibility 3270 */ 3271 struct bpf_attach_target_info tgt_info = {}; 3272 3273 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3274 &tgt_info); 3275 if (err) 3276 goto out_unlock; 3277 3278 if (tgt_info.tgt_mod) { 3279 module_put(prog->aux->mod); 3280 prog->aux->mod = tgt_info.tgt_mod; 3281 } 3282 3283 tr = bpf_trampoline_get(key, &tgt_info); 3284 if (!tr) { 3285 err = -ENOMEM; 3286 goto out_unlock; 3287 } 3288 } else { 3289 /* The caller didn't specify a target, or the target was the 3290 * same as the destination supplied during program load. This 3291 * means we can reuse the trampoline and reference from program 3292 * load time, and there is no need to allocate a new one. This 3293 * can only happen once for any program, as the saved values in 3294 * prog->aux are cleared below. 3295 */ 3296 tr = prog->aux->dst_trampoline; 3297 tgt_prog = prog->aux->dst_prog; 3298 } 3299 3300 err = bpf_link_prime(&link->link.link, &link_primer); 3301 if (err) 3302 goto out_unlock; 3303 3304 err = bpf_trampoline_link_prog(&link->link, tr); 3305 if (err) { 3306 bpf_link_cleanup(&link_primer); 3307 link = NULL; 3308 goto out_unlock; 3309 } 3310 3311 link->tgt_prog = tgt_prog; 3312 link->trampoline = tr; 3313 3314 /* Always clear the trampoline and target prog from prog->aux to make 3315 * sure the original attach destination is not kept alive after a 3316 * program is (re-)attached to another target. 3317 */ 3318 if (prog->aux->dst_prog && 3319 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3320 /* got extra prog ref from syscall, or attaching to different prog */ 3321 bpf_prog_put(prog->aux->dst_prog); 3322 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3323 /* we allocated a new trampoline, so free the old one */ 3324 bpf_trampoline_put(prog->aux->dst_trampoline); 3325 3326 prog->aux->dst_prog = NULL; 3327 prog->aux->dst_trampoline = NULL; 3328 mutex_unlock(&prog->aux->dst_mutex); 3329 3330 return bpf_link_settle(&link_primer); 3331 out_unlock: 3332 if (tr && tr != prog->aux->dst_trampoline) 3333 bpf_trampoline_put(tr); 3334 mutex_unlock(&prog->aux->dst_mutex); 3335 kfree(link); 3336 out_put_prog: 3337 if (tgt_prog_fd && tgt_prog) 3338 bpf_prog_put(tgt_prog); 3339 return err; 3340 } 3341 3342 struct bpf_raw_tp_link { 3343 struct bpf_link link; 3344 struct bpf_raw_event_map *btp; 3345 }; 3346 3347 static void bpf_raw_tp_link_release(struct bpf_link *link) 3348 { 3349 struct bpf_raw_tp_link *raw_tp = 3350 container_of(link, struct bpf_raw_tp_link, link); 3351 3352 bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog); 3353 bpf_put_raw_tracepoint(raw_tp->btp); 3354 } 3355 3356 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3357 { 3358 struct bpf_raw_tp_link *raw_tp = 3359 container_of(link, struct bpf_raw_tp_link, link); 3360 3361 kfree(raw_tp); 3362 } 3363 3364 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3365 struct seq_file *seq) 3366 { 3367 struct bpf_raw_tp_link *raw_tp_link = 3368 container_of(link, struct bpf_raw_tp_link, link); 3369 3370 seq_printf(seq, 3371 "tp_name:\t%s\n", 3372 raw_tp_link->btp->tp->name); 3373 } 3374 3375 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3376 u32 len) 3377 { 3378 if (ulen >= len + 1) { 3379 if (copy_to_user(ubuf, buf, len + 1)) 3380 return -EFAULT; 3381 } else { 3382 char zero = '\0'; 3383 3384 if (copy_to_user(ubuf, buf, ulen - 1)) 3385 return -EFAULT; 3386 if (put_user(zero, ubuf + ulen - 1)) 3387 return -EFAULT; 3388 return -ENOSPC; 3389 } 3390 3391 return 0; 3392 } 3393 3394 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3395 struct bpf_link_info *info) 3396 { 3397 struct bpf_raw_tp_link *raw_tp_link = 3398 container_of(link, struct bpf_raw_tp_link, link); 3399 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3400 const char *tp_name = raw_tp_link->btp->tp->name; 3401 u32 ulen = info->raw_tracepoint.tp_name_len; 3402 size_t tp_len = strlen(tp_name); 3403 3404 if (!ulen ^ !ubuf) 3405 return -EINVAL; 3406 3407 info->raw_tracepoint.tp_name_len = tp_len + 1; 3408 3409 if (!ubuf) 3410 return 0; 3411 3412 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3413 } 3414 3415 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3416 .release = bpf_raw_tp_link_release, 3417 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3418 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3419 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3420 }; 3421 3422 #ifdef CONFIG_PERF_EVENTS 3423 struct bpf_perf_link { 3424 struct bpf_link link; 3425 struct file *perf_file; 3426 }; 3427 3428 static void bpf_perf_link_release(struct bpf_link *link) 3429 { 3430 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3431 struct perf_event *event = perf_link->perf_file->private_data; 3432 3433 perf_event_free_bpf_prog(event); 3434 fput(perf_link->perf_file); 3435 } 3436 3437 static void bpf_perf_link_dealloc(struct bpf_link *link) 3438 { 3439 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3440 3441 kfree(perf_link); 3442 } 3443 3444 static int bpf_perf_link_fill_common(const struct perf_event *event, 3445 char __user *uname, u32 *ulenp, 3446 u64 *probe_offset, u64 *probe_addr, 3447 u32 *fd_type, unsigned long *missed) 3448 { 3449 const char *buf; 3450 u32 prog_id, ulen; 3451 size_t len; 3452 int err; 3453 3454 ulen = *ulenp; 3455 if (!ulen ^ !uname) 3456 return -EINVAL; 3457 3458 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3459 probe_offset, probe_addr, missed); 3460 if (err) 3461 return err; 3462 3463 if (buf) { 3464 len = strlen(buf); 3465 *ulenp = len + 1; 3466 } else { 3467 *ulenp = 1; 3468 } 3469 if (!uname) 3470 return 0; 3471 3472 if (buf) { 3473 err = bpf_copy_to_user(uname, buf, ulen, len); 3474 if (err) 3475 return err; 3476 } else { 3477 char zero = '\0'; 3478 3479 if (put_user(zero, uname)) 3480 return -EFAULT; 3481 } 3482 return 0; 3483 } 3484 3485 #ifdef CONFIG_KPROBE_EVENTS 3486 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 3487 struct bpf_link_info *info) 3488 { 3489 unsigned long missed; 3490 char __user *uname; 3491 u64 addr, offset; 3492 u32 ulen, type; 3493 int err; 3494 3495 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 3496 ulen = info->perf_event.kprobe.name_len; 3497 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 3498 &type, &missed); 3499 if (err) 3500 return err; 3501 if (type == BPF_FD_TYPE_KRETPROBE) 3502 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 3503 else 3504 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 3505 info->perf_event.kprobe.name_len = ulen; 3506 info->perf_event.kprobe.offset = offset; 3507 info->perf_event.kprobe.missed = missed; 3508 if (!kallsyms_show_value(current_cred())) 3509 addr = 0; 3510 info->perf_event.kprobe.addr = addr; 3511 info->perf_event.kprobe.cookie = event->bpf_cookie; 3512 return 0; 3513 } 3514 #endif 3515 3516 #ifdef CONFIG_UPROBE_EVENTS 3517 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 3518 struct bpf_link_info *info) 3519 { 3520 char __user *uname; 3521 u64 addr, offset; 3522 u32 ulen, type; 3523 int err; 3524 3525 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 3526 ulen = info->perf_event.uprobe.name_len; 3527 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 3528 &type, NULL); 3529 if (err) 3530 return err; 3531 3532 if (type == BPF_FD_TYPE_URETPROBE) 3533 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 3534 else 3535 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 3536 info->perf_event.uprobe.name_len = ulen; 3537 info->perf_event.uprobe.offset = offset; 3538 info->perf_event.uprobe.cookie = event->bpf_cookie; 3539 return 0; 3540 } 3541 #endif 3542 3543 static int bpf_perf_link_fill_probe(const struct perf_event *event, 3544 struct bpf_link_info *info) 3545 { 3546 #ifdef CONFIG_KPROBE_EVENTS 3547 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 3548 return bpf_perf_link_fill_kprobe(event, info); 3549 #endif 3550 #ifdef CONFIG_UPROBE_EVENTS 3551 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 3552 return bpf_perf_link_fill_uprobe(event, info); 3553 #endif 3554 return -EOPNOTSUPP; 3555 } 3556 3557 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 3558 struct bpf_link_info *info) 3559 { 3560 char __user *uname; 3561 u32 ulen; 3562 int err; 3563 3564 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 3565 ulen = info->perf_event.tracepoint.name_len; 3566 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 3567 if (err) 3568 return err; 3569 3570 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 3571 info->perf_event.tracepoint.name_len = ulen; 3572 info->perf_event.tracepoint.cookie = event->bpf_cookie; 3573 return 0; 3574 } 3575 3576 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 3577 struct bpf_link_info *info) 3578 { 3579 info->perf_event.event.type = event->attr.type; 3580 info->perf_event.event.config = event->attr.config; 3581 info->perf_event.event.cookie = event->bpf_cookie; 3582 info->perf_event.type = BPF_PERF_EVENT_EVENT; 3583 return 0; 3584 } 3585 3586 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 3587 struct bpf_link_info *info) 3588 { 3589 struct bpf_perf_link *perf_link; 3590 const struct perf_event *event; 3591 3592 perf_link = container_of(link, struct bpf_perf_link, link); 3593 event = perf_get_event(perf_link->perf_file); 3594 if (IS_ERR(event)) 3595 return PTR_ERR(event); 3596 3597 switch (event->prog->type) { 3598 case BPF_PROG_TYPE_PERF_EVENT: 3599 return bpf_perf_link_fill_perf_event(event, info); 3600 case BPF_PROG_TYPE_TRACEPOINT: 3601 return bpf_perf_link_fill_tracepoint(event, info); 3602 case BPF_PROG_TYPE_KPROBE: 3603 return bpf_perf_link_fill_probe(event, info); 3604 default: 3605 return -EOPNOTSUPP; 3606 } 3607 } 3608 3609 static const struct bpf_link_ops bpf_perf_link_lops = { 3610 .release = bpf_perf_link_release, 3611 .dealloc = bpf_perf_link_dealloc, 3612 .fill_link_info = bpf_perf_link_fill_link_info, 3613 }; 3614 3615 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3616 { 3617 struct bpf_link_primer link_primer; 3618 struct bpf_perf_link *link; 3619 struct perf_event *event; 3620 struct file *perf_file; 3621 int err; 3622 3623 if (attr->link_create.flags) 3624 return -EINVAL; 3625 3626 perf_file = perf_event_get(attr->link_create.target_fd); 3627 if (IS_ERR(perf_file)) 3628 return PTR_ERR(perf_file); 3629 3630 link = kzalloc(sizeof(*link), GFP_USER); 3631 if (!link) { 3632 err = -ENOMEM; 3633 goto out_put_file; 3634 } 3635 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog); 3636 link->perf_file = perf_file; 3637 3638 err = bpf_link_prime(&link->link, &link_primer); 3639 if (err) { 3640 kfree(link); 3641 goto out_put_file; 3642 } 3643 3644 event = perf_file->private_data; 3645 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 3646 if (err) { 3647 bpf_link_cleanup(&link_primer); 3648 goto out_put_file; 3649 } 3650 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 3651 bpf_prog_inc(prog); 3652 3653 return bpf_link_settle(&link_primer); 3654 3655 out_put_file: 3656 fput(perf_file); 3657 return err; 3658 } 3659 #else 3660 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3661 { 3662 return -EOPNOTSUPP; 3663 } 3664 #endif /* CONFIG_PERF_EVENTS */ 3665 3666 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 3667 const char __user *user_tp_name) 3668 { 3669 struct bpf_link_primer link_primer; 3670 struct bpf_raw_tp_link *link; 3671 struct bpf_raw_event_map *btp; 3672 const char *tp_name; 3673 char buf[128]; 3674 int err; 3675 3676 switch (prog->type) { 3677 case BPF_PROG_TYPE_TRACING: 3678 case BPF_PROG_TYPE_EXT: 3679 case BPF_PROG_TYPE_LSM: 3680 if (user_tp_name) 3681 /* The attach point for this category of programs 3682 * should be specified via btf_id during program load. 3683 */ 3684 return -EINVAL; 3685 if (prog->type == BPF_PROG_TYPE_TRACING && 3686 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 3687 tp_name = prog->aux->attach_func_name; 3688 break; 3689 } 3690 return bpf_tracing_prog_attach(prog, 0, 0, 0); 3691 case BPF_PROG_TYPE_RAW_TRACEPOINT: 3692 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 3693 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 3694 return -EFAULT; 3695 buf[sizeof(buf) - 1] = 0; 3696 tp_name = buf; 3697 break; 3698 default: 3699 return -EINVAL; 3700 } 3701 3702 btp = bpf_get_raw_tracepoint(tp_name); 3703 if (!btp) 3704 return -ENOENT; 3705 3706 link = kzalloc(sizeof(*link), GFP_USER); 3707 if (!link) { 3708 err = -ENOMEM; 3709 goto out_put_btp; 3710 } 3711 bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 3712 &bpf_raw_tp_link_lops, prog); 3713 link->btp = btp; 3714 3715 err = bpf_link_prime(&link->link, &link_primer); 3716 if (err) { 3717 kfree(link); 3718 goto out_put_btp; 3719 } 3720 3721 err = bpf_probe_register(link->btp, prog); 3722 if (err) { 3723 bpf_link_cleanup(&link_primer); 3724 goto out_put_btp; 3725 } 3726 3727 return bpf_link_settle(&link_primer); 3728 3729 out_put_btp: 3730 bpf_put_raw_tracepoint(btp); 3731 return err; 3732 } 3733 3734 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd 3735 3736 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 3737 { 3738 struct bpf_prog *prog; 3739 int fd; 3740 3741 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 3742 return -EINVAL; 3743 3744 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 3745 if (IS_ERR(prog)) 3746 return PTR_ERR(prog); 3747 3748 fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name)); 3749 if (fd < 0) 3750 bpf_prog_put(prog); 3751 return fd; 3752 } 3753 3754 static enum bpf_prog_type 3755 attach_type_to_prog_type(enum bpf_attach_type attach_type) 3756 { 3757 switch (attach_type) { 3758 case BPF_CGROUP_INET_INGRESS: 3759 case BPF_CGROUP_INET_EGRESS: 3760 return BPF_PROG_TYPE_CGROUP_SKB; 3761 case BPF_CGROUP_INET_SOCK_CREATE: 3762 case BPF_CGROUP_INET_SOCK_RELEASE: 3763 case BPF_CGROUP_INET4_POST_BIND: 3764 case BPF_CGROUP_INET6_POST_BIND: 3765 return BPF_PROG_TYPE_CGROUP_SOCK; 3766 case BPF_CGROUP_INET4_BIND: 3767 case BPF_CGROUP_INET6_BIND: 3768 case BPF_CGROUP_INET4_CONNECT: 3769 case BPF_CGROUP_INET6_CONNECT: 3770 case BPF_CGROUP_INET4_GETPEERNAME: 3771 case BPF_CGROUP_INET6_GETPEERNAME: 3772 case BPF_CGROUP_INET4_GETSOCKNAME: 3773 case BPF_CGROUP_INET6_GETSOCKNAME: 3774 case BPF_CGROUP_UDP4_SENDMSG: 3775 case BPF_CGROUP_UDP6_SENDMSG: 3776 case BPF_CGROUP_UDP4_RECVMSG: 3777 case BPF_CGROUP_UDP6_RECVMSG: 3778 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 3779 case BPF_CGROUP_SOCK_OPS: 3780 return BPF_PROG_TYPE_SOCK_OPS; 3781 case BPF_CGROUP_DEVICE: 3782 return BPF_PROG_TYPE_CGROUP_DEVICE; 3783 case BPF_SK_MSG_VERDICT: 3784 return BPF_PROG_TYPE_SK_MSG; 3785 case BPF_SK_SKB_STREAM_PARSER: 3786 case BPF_SK_SKB_STREAM_VERDICT: 3787 case BPF_SK_SKB_VERDICT: 3788 return BPF_PROG_TYPE_SK_SKB; 3789 case BPF_LIRC_MODE2: 3790 return BPF_PROG_TYPE_LIRC_MODE2; 3791 case BPF_FLOW_DISSECTOR: 3792 return BPF_PROG_TYPE_FLOW_DISSECTOR; 3793 case BPF_CGROUP_SYSCTL: 3794 return BPF_PROG_TYPE_CGROUP_SYSCTL; 3795 case BPF_CGROUP_GETSOCKOPT: 3796 case BPF_CGROUP_SETSOCKOPT: 3797 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 3798 case BPF_TRACE_ITER: 3799 case BPF_TRACE_RAW_TP: 3800 case BPF_TRACE_FENTRY: 3801 case BPF_TRACE_FEXIT: 3802 case BPF_MODIFY_RETURN: 3803 return BPF_PROG_TYPE_TRACING; 3804 case BPF_LSM_MAC: 3805 return BPF_PROG_TYPE_LSM; 3806 case BPF_SK_LOOKUP: 3807 return BPF_PROG_TYPE_SK_LOOKUP; 3808 case BPF_XDP: 3809 return BPF_PROG_TYPE_XDP; 3810 case BPF_LSM_CGROUP: 3811 return BPF_PROG_TYPE_LSM; 3812 case BPF_TCX_INGRESS: 3813 case BPF_TCX_EGRESS: 3814 return BPF_PROG_TYPE_SCHED_CLS; 3815 default: 3816 return BPF_PROG_TYPE_UNSPEC; 3817 } 3818 } 3819 3820 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 3821 enum bpf_attach_type attach_type) 3822 { 3823 enum bpf_prog_type ptype; 3824 3825 switch (prog->type) { 3826 case BPF_PROG_TYPE_CGROUP_SOCK: 3827 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3828 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3829 case BPF_PROG_TYPE_SK_LOOKUP: 3830 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 3831 case BPF_PROG_TYPE_CGROUP_SKB: 3832 if (!capable(CAP_NET_ADMIN)) 3833 /* cg-skb progs can be loaded by unpriv user. 3834 * check permissions at attach time. 3835 */ 3836 return -EPERM; 3837 3838 ptype = attach_type_to_prog_type(attach_type); 3839 if (prog->type != ptype) 3840 return -EINVAL; 3841 3842 return prog->enforce_expected_attach_type && 3843 prog->expected_attach_type != attach_type ? 3844 -EINVAL : 0; 3845 case BPF_PROG_TYPE_EXT: 3846 return 0; 3847 case BPF_PROG_TYPE_NETFILTER: 3848 if (attach_type != BPF_NETFILTER) 3849 return -EINVAL; 3850 return 0; 3851 case BPF_PROG_TYPE_PERF_EVENT: 3852 case BPF_PROG_TYPE_TRACEPOINT: 3853 if (attach_type != BPF_PERF_EVENT) 3854 return -EINVAL; 3855 return 0; 3856 case BPF_PROG_TYPE_KPROBE: 3857 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 3858 attach_type != BPF_TRACE_KPROBE_MULTI) 3859 return -EINVAL; 3860 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 3861 attach_type != BPF_TRACE_UPROBE_MULTI) 3862 return -EINVAL; 3863 if (attach_type != BPF_PERF_EVENT && 3864 attach_type != BPF_TRACE_KPROBE_MULTI && 3865 attach_type != BPF_TRACE_UPROBE_MULTI) 3866 return -EINVAL; 3867 return 0; 3868 case BPF_PROG_TYPE_SCHED_CLS: 3869 if (attach_type != BPF_TCX_INGRESS && 3870 attach_type != BPF_TCX_EGRESS) 3871 return -EINVAL; 3872 return 0; 3873 default: 3874 ptype = attach_type_to_prog_type(attach_type); 3875 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 3876 return -EINVAL; 3877 return 0; 3878 } 3879 } 3880 3881 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 3882 3883 #define BPF_F_ATTACH_MASK_BASE \ 3884 (BPF_F_ALLOW_OVERRIDE | \ 3885 BPF_F_ALLOW_MULTI | \ 3886 BPF_F_REPLACE) 3887 3888 #define BPF_F_ATTACH_MASK_MPROG \ 3889 (BPF_F_REPLACE | \ 3890 BPF_F_BEFORE | \ 3891 BPF_F_AFTER | \ 3892 BPF_F_ID | \ 3893 BPF_F_LINK) 3894 3895 static int bpf_prog_attach(const union bpf_attr *attr) 3896 { 3897 enum bpf_prog_type ptype; 3898 struct bpf_prog *prog; 3899 int ret; 3900 3901 if (CHECK_ATTR(BPF_PROG_ATTACH)) 3902 return -EINVAL; 3903 3904 ptype = attach_type_to_prog_type(attr->attach_type); 3905 if (ptype == BPF_PROG_TYPE_UNSPEC) 3906 return -EINVAL; 3907 if (bpf_mprog_supported(ptype)) { 3908 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 3909 return -EINVAL; 3910 } else { 3911 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 3912 return -EINVAL; 3913 if (attr->relative_fd || 3914 attr->expected_revision) 3915 return -EINVAL; 3916 } 3917 3918 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 3919 if (IS_ERR(prog)) 3920 return PTR_ERR(prog); 3921 3922 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 3923 bpf_prog_put(prog); 3924 return -EINVAL; 3925 } 3926 3927 switch (ptype) { 3928 case BPF_PROG_TYPE_SK_SKB: 3929 case BPF_PROG_TYPE_SK_MSG: 3930 ret = sock_map_get_from_fd(attr, prog); 3931 break; 3932 case BPF_PROG_TYPE_LIRC_MODE2: 3933 ret = lirc_prog_attach(attr, prog); 3934 break; 3935 case BPF_PROG_TYPE_FLOW_DISSECTOR: 3936 ret = netns_bpf_prog_attach(attr, prog); 3937 break; 3938 case BPF_PROG_TYPE_CGROUP_DEVICE: 3939 case BPF_PROG_TYPE_CGROUP_SKB: 3940 case BPF_PROG_TYPE_CGROUP_SOCK: 3941 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3942 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3943 case BPF_PROG_TYPE_CGROUP_SYSCTL: 3944 case BPF_PROG_TYPE_SOCK_OPS: 3945 case BPF_PROG_TYPE_LSM: 3946 if (ptype == BPF_PROG_TYPE_LSM && 3947 prog->expected_attach_type != BPF_LSM_CGROUP) 3948 ret = -EINVAL; 3949 else 3950 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 3951 break; 3952 case BPF_PROG_TYPE_SCHED_CLS: 3953 ret = tcx_prog_attach(attr, prog); 3954 break; 3955 default: 3956 ret = -EINVAL; 3957 } 3958 3959 if (ret) 3960 bpf_prog_put(prog); 3961 return ret; 3962 } 3963 3964 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 3965 3966 static int bpf_prog_detach(const union bpf_attr *attr) 3967 { 3968 struct bpf_prog *prog = NULL; 3969 enum bpf_prog_type ptype; 3970 int ret; 3971 3972 if (CHECK_ATTR(BPF_PROG_DETACH)) 3973 return -EINVAL; 3974 3975 ptype = attach_type_to_prog_type(attr->attach_type); 3976 if (bpf_mprog_supported(ptype)) { 3977 if (ptype == BPF_PROG_TYPE_UNSPEC) 3978 return -EINVAL; 3979 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 3980 return -EINVAL; 3981 if (attr->attach_bpf_fd) { 3982 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 3983 if (IS_ERR(prog)) 3984 return PTR_ERR(prog); 3985 } 3986 } else if (attr->attach_flags || 3987 attr->relative_fd || 3988 attr->expected_revision) { 3989 return -EINVAL; 3990 } 3991 3992 switch (ptype) { 3993 case BPF_PROG_TYPE_SK_MSG: 3994 case BPF_PROG_TYPE_SK_SKB: 3995 ret = sock_map_prog_detach(attr, ptype); 3996 break; 3997 case BPF_PROG_TYPE_LIRC_MODE2: 3998 ret = lirc_prog_detach(attr); 3999 break; 4000 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4001 ret = netns_bpf_prog_detach(attr, ptype); 4002 break; 4003 case BPF_PROG_TYPE_CGROUP_DEVICE: 4004 case BPF_PROG_TYPE_CGROUP_SKB: 4005 case BPF_PROG_TYPE_CGROUP_SOCK: 4006 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4007 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4008 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4009 case BPF_PROG_TYPE_SOCK_OPS: 4010 case BPF_PROG_TYPE_LSM: 4011 ret = cgroup_bpf_prog_detach(attr, ptype); 4012 break; 4013 case BPF_PROG_TYPE_SCHED_CLS: 4014 ret = tcx_prog_detach(attr, prog); 4015 break; 4016 default: 4017 ret = -EINVAL; 4018 } 4019 4020 if (prog) 4021 bpf_prog_put(prog); 4022 return ret; 4023 } 4024 4025 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4026 4027 static int bpf_prog_query(const union bpf_attr *attr, 4028 union bpf_attr __user *uattr) 4029 { 4030 if (!capable(CAP_NET_ADMIN)) 4031 return -EPERM; 4032 if (CHECK_ATTR(BPF_PROG_QUERY)) 4033 return -EINVAL; 4034 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4035 return -EINVAL; 4036 4037 switch (attr->query.attach_type) { 4038 case BPF_CGROUP_INET_INGRESS: 4039 case BPF_CGROUP_INET_EGRESS: 4040 case BPF_CGROUP_INET_SOCK_CREATE: 4041 case BPF_CGROUP_INET_SOCK_RELEASE: 4042 case BPF_CGROUP_INET4_BIND: 4043 case BPF_CGROUP_INET6_BIND: 4044 case BPF_CGROUP_INET4_POST_BIND: 4045 case BPF_CGROUP_INET6_POST_BIND: 4046 case BPF_CGROUP_INET4_CONNECT: 4047 case BPF_CGROUP_INET6_CONNECT: 4048 case BPF_CGROUP_INET4_GETPEERNAME: 4049 case BPF_CGROUP_INET6_GETPEERNAME: 4050 case BPF_CGROUP_INET4_GETSOCKNAME: 4051 case BPF_CGROUP_INET6_GETSOCKNAME: 4052 case BPF_CGROUP_UDP4_SENDMSG: 4053 case BPF_CGROUP_UDP6_SENDMSG: 4054 case BPF_CGROUP_UDP4_RECVMSG: 4055 case BPF_CGROUP_UDP6_RECVMSG: 4056 case BPF_CGROUP_SOCK_OPS: 4057 case BPF_CGROUP_DEVICE: 4058 case BPF_CGROUP_SYSCTL: 4059 case BPF_CGROUP_GETSOCKOPT: 4060 case BPF_CGROUP_SETSOCKOPT: 4061 case BPF_LSM_CGROUP: 4062 return cgroup_bpf_prog_query(attr, uattr); 4063 case BPF_LIRC_MODE2: 4064 return lirc_prog_query(attr, uattr); 4065 case BPF_FLOW_DISSECTOR: 4066 case BPF_SK_LOOKUP: 4067 return netns_bpf_prog_query(attr, uattr); 4068 case BPF_SK_SKB_STREAM_PARSER: 4069 case BPF_SK_SKB_STREAM_VERDICT: 4070 case BPF_SK_MSG_VERDICT: 4071 case BPF_SK_SKB_VERDICT: 4072 return sock_map_bpf_prog_query(attr, uattr); 4073 case BPF_TCX_INGRESS: 4074 case BPF_TCX_EGRESS: 4075 return tcx_prog_query(attr, uattr); 4076 default: 4077 return -EINVAL; 4078 } 4079 } 4080 4081 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4082 4083 static int bpf_prog_test_run(const union bpf_attr *attr, 4084 union bpf_attr __user *uattr) 4085 { 4086 struct bpf_prog *prog; 4087 int ret = -ENOTSUPP; 4088 4089 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4090 return -EINVAL; 4091 4092 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4093 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4094 return -EINVAL; 4095 4096 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4097 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4098 return -EINVAL; 4099 4100 prog = bpf_prog_get(attr->test.prog_fd); 4101 if (IS_ERR(prog)) 4102 return PTR_ERR(prog); 4103 4104 if (prog->aux->ops->test_run) 4105 ret = prog->aux->ops->test_run(prog, attr, uattr); 4106 4107 bpf_prog_put(prog); 4108 return ret; 4109 } 4110 4111 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4112 4113 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4114 union bpf_attr __user *uattr, 4115 struct idr *idr, 4116 spinlock_t *lock) 4117 { 4118 u32 next_id = attr->start_id; 4119 int err = 0; 4120 4121 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4122 return -EINVAL; 4123 4124 if (!capable(CAP_SYS_ADMIN)) 4125 return -EPERM; 4126 4127 next_id++; 4128 spin_lock_bh(lock); 4129 if (!idr_get_next(idr, &next_id)) 4130 err = -ENOENT; 4131 spin_unlock_bh(lock); 4132 4133 if (!err) 4134 err = put_user(next_id, &uattr->next_id); 4135 4136 return err; 4137 } 4138 4139 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4140 { 4141 struct bpf_map *map; 4142 4143 spin_lock_bh(&map_idr_lock); 4144 again: 4145 map = idr_get_next(&map_idr, id); 4146 if (map) { 4147 map = __bpf_map_inc_not_zero(map, false); 4148 if (IS_ERR(map)) { 4149 (*id)++; 4150 goto again; 4151 } 4152 } 4153 spin_unlock_bh(&map_idr_lock); 4154 4155 return map; 4156 } 4157 4158 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4159 { 4160 struct bpf_prog *prog; 4161 4162 spin_lock_bh(&prog_idr_lock); 4163 again: 4164 prog = idr_get_next(&prog_idr, id); 4165 if (prog) { 4166 prog = bpf_prog_inc_not_zero(prog); 4167 if (IS_ERR(prog)) { 4168 (*id)++; 4169 goto again; 4170 } 4171 } 4172 spin_unlock_bh(&prog_idr_lock); 4173 4174 return prog; 4175 } 4176 4177 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4178 4179 struct bpf_prog *bpf_prog_by_id(u32 id) 4180 { 4181 struct bpf_prog *prog; 4182 4183 if (!id) 4184 return ERR_PTR(-ENOENT); 4185 4186 spin_lock_bh(&prog_idr_lock); 4187 prog = idr_find(&prog_idr, id); 4188 if (prog) 4189 prog = bpf_prog_inc_not_zero(prog); 4190 else 4191 prog = ERR_PTR(-ENOENT); 4192 spin_unlock_bh(&prog_idr_lock); 4193 return prog; 4194 } 4195 4196 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4197 { 4198 struct bpf_prog *prog; 4199 u32 id = attr->prog_id; 4200 int fd; 4201 4202 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4203 return -EINVAL; 4204 4205 if (!capable(CAP_SYS_ADMIN)) 4206 return -EPERM; 4207 4208 prog = bpf_prog_by_id(id); 4209 if (IS_ERR(prog)) 4210 return PTR_ERR(prog); 4211 4212 fd = bpf_prog_new_fd(prog); 4213 if (fd < 0) 4214 bpf_prog_put(prog); 4215 4216 return fd; 4217 } 4218 4219 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4220 4221 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4222 { 4223 struct bpf_map *map; 4224 u32 id = attr->map_id; 4225 int f_flags; 4226 int fd; 4227 4228 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4229 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4230 return -EINVAL; 4231 4232 if (!capable(CAP_SYS_ADMIN)) 4233 return -EPERM; 4234 4235 f_flags = bpf_get_file_flag(attr->open_flags); 4236 if (f_flags < 0) 4237 return f_flags; 4238 4239 spin_lock_bh(&map_idr_lock); 4240 map = idr_find(&map_idr, id); 4241 if (map) 4242 map = __bpf_map_inc_not_zero(map, true); 4243 else 4244 map = ERR_PTR(-ENOENT); 4245 spin_unlock_bh(&map_idr_lock); 4246 4247 if (IS_ERR(map)) 4248 return PTR_ERR(map); 4249 4250 fd = bpf_map_new_fd(map, f_flags); 4251 if (fd < 0) 4252 bpf_map_put_with_uref(map); 4253 4254 return fd; 4255 } 4256 4257 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4258 unsigned long addr, u32 *off, 4259 u32 *type) 4260 { 4261 const struct bpf_map *map; 4262 int i; 4263 4264 mutex_lock(&prog->aux->used_maps_mutex); 4265 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4266 map = prog->aux->used_maps[i]; 4267 if (map == (void *)addr) { 4268 *type = BPF_PSEUDO_MAP_FD; 4269 goto out; 4270 } 4271 if (!map->ops->map_direct_value_meta) 4272 continue; 4273 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4274 *type = BPF_PSEUDO_MAP_VALUE; 4275 goto out; 4276 } 4277 } 4278 map = NULL; 4279 4280 out: 4281 mutex_unlock(&prog->aux->used_maps_mutex); 4282 return map; 4283 } 4284 4285 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 4286 const struct cred *f_cred) 4287 { 4288 const struct bpf_map *map; 4289 struct bpf_insn *insns; 4290 u32 off, type; 4291 u64 imm; 4292 u8 code; 4293 int i; 4294 4295 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 4296 GFP_USER); 4297 if (!insns) 4298 return insns; 4299 4300 for (i = 0; i < prog->len; i++) { 4301 code = insns[i].code; 4302 4303 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 4304 insns[i].code = BPF_JMP | BPF_CALL; 4305 insns[i].imm = BPF_FUNC_tail_call; 4306 /* fall-through */ 4307 } 4308 if (code == (BPF_JMP | BPF_CALL) || 4309 code == (BPF_JMP | BPF_CALL_ARGS)) { 4310 if (code == (BPF_JMP | BPF_CALL_ARGS)) 4311 insns[i].code = BPF_JMP | BPF_CALL; 4312 if (!bpf_dump_raw_ok(f_cred)) 4313 insns[i].imm = 0; 4314 continue; 4315 } 4316 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 4317 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 4318 continue; 4319 } 4320 4321 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 4322 continue; 4323 4324 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 4325 map = bpf_map_from_imm(prog, imm, &off, &type); 4326 if (map) { 4327 insns[i].src_reg = type; 4328 insns[i].imm = map->id; 4329 insns[i + 1].imm = off; 4330 continue; 4331 } 4332 } 4333 4334 return insns; 4335 } 4336 4337 static int set_info_rec_size(struct bpf_prog_info *info) 4338 { 4339 /* 4340 * Ensure info.*_rec_size is the same as kernel expected size 4341 * 4342 * or 4343 * 4344 * Only allow zero *_rec_size if both _rec_size and _cnt are 4345 * zero. In this case, the kernel will set the expected 4346 * _rec_size back to the info. 4347 */ 4348 4349 if ((info->nr_func_info || info->func_info_rec_size) && 4350 info->func_info_rec_size != sizeof(struct bpf_func_info)) 4351 return -EINVAL; 4352 4353 if ((info->nr_line_info || info->line_info_rec_size) && 4354 info->line_info_rec_size != sizeof(struct bpf_line_info)) 4355 return -EINVAL; 4356 4357 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 4358 info->jited_line_info_rec_size != sizeof(__u64)) 4359 return -EINVAL; 4360 4361 info->func_info_rec_size = sizeof(struct bpf_func_info); 4362 info->line_info_rec_size = sizeof(struct bpf_line_info); 4363 info->jited_line_info_rec_size = sizeof(__u64); 4364 4365 return 0; 4366 } 4367 4368 static int bpf_prog_get_info_by_fd(struct file *file, 4369 struct bpf_prog *prog, 4370 const union bpf_attr *attr, 4371 union bpf_attr __user *uattr) 4372 { 4373 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4374 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 4375 struct bpf_prog_info info; 4376 u32 info_len = attr->info.info_len; 4377 struct bpf_prog_kstats stats; 4378 char __user *uinsns; 4379 u32 ulen; 4380 int err; 4381 4382 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4383 if (err) 4384 return err; 4385 info_len = min_t(u32, sizeof(info), info_len); 4386 4387 memset(&info, 0, sizeof(info)); 4388 if (copy_from_user(&info, uinfo, info_len)) 4389 return -EFAULT; 4390 4391 info.type = prog->type; 4392 info.id = prog->aux->id; 4393 info.load_time = prog->aux->load_time; 4394 info.created_by_uid = from_kuid_munged(current_user_ns(), 4395 prog->aux->user->uid); 4396 info.gpl_compatible = prog->gpl_compatible; 4397 4398 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 4399 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 4400 4401 mutex_lock(&prog->aux->used_maps_mutex); 4402 ulen = info.nr_map_ids; 4403 info.nr_map_ids = prog->aux->used_map_cnt; 4404 ulen = min_t(u32, info.nr_map_ids, ulen); 4405 if (ulen) { 4406 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 4407 u32 i; 4408 4409 for (i = 0; i < ulen; i++) 4410 if (put_user(prog->aux->used_maps[i]->id, 4411 &user_map_ids[i])) { 4412 mutex_unlock(&prog->aux->used_maps_mutex); 4413 return -EFAULT; 4414 } 4415 } 4416 mutex_unlock(&prog->aux->used_maps_mutex); 4417 4418 err = set_info_rec_size(&info); 4419 if (err) 4420 return err; 4421 4422 bpf_prog_get_stats(prog, &stats); 4423 info.run_time_ns = stats.nsecs; 4424 info.run_cnt = stats.cnt; 4425 info.recursion_misses = stats.misses; 4426 4427 info.verified_insns = prog->aux->verified_insns; 4428 4429 if (!bpf_capable()) { 4430 info.jited_prog_len = 0; 4431 info.xlated_prog_len = 0; 4432 info.nr_jited_ksyms = 0; 4433 info.nr_jited_func_lens = 0; 4434 info.nr_func_info = 0; 4435 info.nr_line_info = 0; 4436 info.nr_jited_line_info = 0; 4437 goto done; 4438 } 4439 4440 ulen = info.xlated_prog_len; 4441 info.xlated_prog_len = bpf_prog_insn_size(prog); 4442 if (info.xlated_prog_len && ulen) { 4443 struct bpf_insn *insns_sanitized; 4444 bool fault; 4445 4446 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) { 4447 info.xlated_prog_insns = 0; 4448 goto done; 4449 } 4450 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 4451 if (!insns_sanitized) 4452 return -ENOMEM; 4453 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 4454 ulen = min_t(u32, info.xlated_prog_len, ulen); 4455 fault = copy_to_user(uinsns, insns_sanitized, ulen); 4456 kfree(insns_sanitized); 4457 if (fault) 4458 return -EFAULT; 4459 } 4460 4461 if (bpf_prog_is_offloaded(prog->aux)) { 4462 err = bpf_prog_offload_info_fill(&info, prog); 4463 if (err) 4464 return err; 4465 goto done; 4466 } 4467 4468 /* NOTE: the following code is supposed to be skipped for offload. 4469 * bpf_prog_offload_info_fill() is the place to fill similar fields 4470 * for offload. 4471 */ 4472 ulen = info.jited_prog_len; 4473 if (prog->aux->func_cnt) { 4474 u32 i; 4475 4476 info.jited_prog_len = 0; 4477 for (i = 0; i < prog->aux->func_cnt; i++) 4478 info.jited_prog_len += prog->aux->func[i]->jited_len; 4479 } else { 4480 info.jited_prog_len = prog->jited_len; 4481 } 4482 4483 if (info.jited_prog_len && ulen) { 4484 if (bpf_dump_raw_ok(file->f_cred)) { 4485 uinsns = u64_to_user_ptr(info.jited_prog_insns); 4486 ulen = min_t(u32, info.jited_prog_len, ulen); 4487 4488 /* for multi-function programs, copy the JITed 4489 * instructions for all the functions 4490 */ 4491 if (prog->aux->func_cnt) { 4492 u32 len, free, i; 4493 u8 *img; 4494 4495 free = ulen; 4496 for (i = 0; i < prog->aux->func_cnt; i++) { 4497 len = prog->aux->func[i]->jited_len; 4498 len = min_t(u32, len, free); 4499 img = (u8 *) prog->aux->func[i]->bpf_func; 4500 if (copy_to_user(uinsns, img, len)) 4501 return -EFAULT; 4502 uinsns += len; 4503 free -= len; 4504 if (!free) 4505 break; 4506 } 4507 } else { 4508 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 4509 return -EFAULT; 4510 } 4511 } else { 4512 info.jited_prog_insns = 0; 4513 } 4514 } 4515 4516 ulen = info.nr_jited_ksyms; 4517 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 4518 if (ulen) { 4519 if (bpf_dump_raw_ok(file->f_cred)) { 4520 unsigned long ksym_addr; 4521 u64 __user *user_ksyms; 4522 u32 i; 4523 4524 /* copy the address of the kernel symbol 4525 * corresponding to each function 4526 */ 4527 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 4528 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 4529 if (prog->aux->func_cnt) { 4530 for (i = 0; i < ulen; i++) { 4531 ksym_addr = (unsigned long) 4532 prog->aux->func[i]->bpf_func; 4533 if (put_user((u64) ksym_addr, 4534 &user_ksyms[i])) 4535 return -EFAULT; 4536 } 4537 } else { 4538 ksym_addr = (unsigned long) prog->bpf_func; 4539 if (put_user((u64) ksym_addr, &user_ksyms[0])) 4540 return -EFAULT; 4541 } 4542 } else { 4543 info.jited_ksyms = 0; 4544 } 4545 } 4546 4547 ulen = info.nr_jited_func_lens; 4548 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 4549 if (ulen) { 4550 if (bpf_dump_raw_ok(file->f_cred)) { 4551 u32 __user *user_lens; 4552 u32 func_len, i; 4553 4554 /* copy the JITed image lengths for each function */ 4555 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 4556 user_lens = u64_to_user_ptr(info.jited_func_lens); 4557 if (prog->aux->func_cnt) { 4558 for (i = 0; i < ulen; i++) { 4559 func_len = 4560 prog->aux->func[i]->jited_len; 4561 if (put_user(func_len, &user_lens[i])) 4562 return -EFAULT; 4563 } 4564 } else { 4565 func_len = prog->jited_len; 4566 if (put_user(func_len, &user_lens[0])) 4567 return -EFAULT; 4568 } 4569 } else { 4570 info.jited_func_lens = 0; 4571 } 4572 } 4573 4574 if (prog->aux->btf) 4575 info.btf_id = btf_obj_id(prog->aux->btf); 4576 info.attach_btf_id = prog->aux->attach_btf_id; 4577 if (attach_btf) 4578 info.attach_btf_obj_id = btf_obj_id(attach_btf); 4579 4580 ulen = info.nr_func_info; 4581 info.nr_func_info = prog->aux->func_info_cnt; 4582 if (info.nr_func_info && ulen) { 4583 char __user *user_finfo; 4584 4585 user_finfo = u64_to_user_ptr(info.func_info); 4586 ulen = min_t(u32, info.nr_func_info, ulen); 4587 if (copy_to_user(user_finfo, prog->aux->func_info, 4588 info.func_info_rec_size * ulen)) 4589 return -EFAULT; 4590 } 4591 4592 ulen = info.nr_line_info; 4593 info.nr_line_info = prog->aux->nr_linfo; 4594 if (info.nr_line_info && ulen) { 4595 __u8 __user *user_linfo; 4596 4597 user_linfo = u64_to_user_ptr(info.line_info); 4598 ulen = min_t(u32, info.nr_line_info, ulen); 4599 if (copy_to_user(user_linfo, prog->aux->linfo, 4600 info.line_info_rec_size * ulen)) 4601 return -EFAULT; 4602 } 4603 4604 ulen = info.nr_jited_line_info; 4605 if (prog->aux->jited_linfo) 4606 info.nr_jited_line_info = prog->aux->nr_linfo; 4607 else 4608 info.nr_jited_line_info = 0; 4609 if (info.nr_jited_line_info && ulen) { 4610 if (bpf_dump_raw_ok(file->f_cred)) { 4611 unsigned long line_addr; 4612 __u64 __user *user_linfo; 4613 u32 i; 4614 4615 user_linfo = u64_to_user_ptr(info.jited_line_info); 4616 ulen = min_t(u32, info.nr_jited_line_info, ulen); 4617 for (i = 0; i < ulen; i++) { 4618 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 4619 if (put_user((__u64)line_addr, &user_linfo[i])) 4620 return -EFAULT; 4621 } 4622 } else { 4623 info.jited_line_info = 0; 4624 } 4625 } 4626 4627 ulen = info.nr_prog_tags; 4628 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 4629 if (ulen) { 4630 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 4631 u32 i; 4632 4633 user_prog_tags = u64_to_user_ptr(info.prog_tags); 4634 ulen = min_t(u32, info.nr_prog_tags, ulen); 4635 if (prog->aux->func_cnt) { 4636 for (i = 0; i < ulen; i++) { 4637 if (copy_to_user(user_prog_tags[i], 4638 prog->aux->func[i]->tag, 4639 BPF_TAG_SIZE)) 4640 return -EFAULT; 4641 } 4642 } else { 4643 if (copy_to_user(user_prog_tags[0], 4644 prog->tag, BPF_TAG_SIZE)) 4645 return -EFAULT; 4646 } 4647 } 4648 4649 done: 4650 if (copy_to_user(uinfo, &info, info_len) || 4651 put_user(info_len, &uattr->info.info_len)) 4652 return -EFAULT; 4653 4654 return 0; 4655 } 4656 4657 static int bpf_map_get_info_by_fd(struct file *file, 4658 struct bpf_map *map, 4659 const union bpf_attr *attr, 4660 union bpf_attr __user *uattr) 4661 { 4662 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4663 struct bpf_map_info info; 4664 u32 info_len = attr->info.info_len; 4665 int err; 4666 4667 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4668 if (err) 4669 return err; 4670 info_len = min_t(u32, sizeof(info), info_len); 4671 4672 memset(&info, 0, sizeof(info)); 4673 info.type = map->map_type; 4674 info.id = map->id; 4675 info.key_size = map->key_size; 4676 info.value_size = map->value_size; 4677 info.max_entries = map->max_entries; 4678 info.map_flags = map->map_flags; 4679 info.map_extra = map->map_extra; 4680 memcpy(info.name, map->name, sizeof(map->name)); 4681 4682 if (map->btf) { 4683 info.btf_id = btf_obj_id(map->btf); 4684 info.btf_key_type_id = map->btf_key_type_id; 4685 info.btf_value_type_id = map->btf_value_type_id; 4686 } 4687 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 4688 4689 if (bpf_map_is_offloaded(map)) { 4690 err = bpf_map_offload_info_fill(&info, map); 4691 if (err) 4692 return err; 4693 } 4694 4695 if (copy_to_user(uinfo, &info, info_len) || 4696 put_user(info_len, &uattr->info.info_len)) 4697 return -EFAULT; 4698 4699 return 0; 4700 } 4701 4702 static int bpf_btf_get_info_by_fd(struct file *file, 4703 struct btf *btf, 4704 const union bpf_attr *attr, 4705 union bpf_attr __user *uattr) 4706 { 4707 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4708 u32 info_len = attr->info.info_len; 4709 int err; 4710 4711 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 4712 if (err) 4713 return err; 4714 4715 return btf_get_info_by_fd(btf, attr, uattr); 4716 } 4717 4718 static int bpf_link_get_info_by_fd(struct file *file, 4719 struct bpf_link *link, 4720 const union bpf_attr *attr, 4721 union bpf_attr __user *uattr) 4722 { 4723 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4724 struct bpf_link_info info; 4725 u32 info_len = attr->info.info_len; 4726 int err; 4727 4728 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4729 if (err) 4730 return err; 4731 info_len = min_t(u32, sizeof(info), info_len); 4732 4733 memset(&info, 0, sizeof(info)); 4734 if (copy_from_user(&info, uinfo, info_len)) 4735 return -EFAULT; 4736 4737 info.type = link->type; 4738 info.id = link->id; 4739 if (link->prog) 4740 info.prog_id = link->prog->aux->id; 4741 4742 if (link->ops->fill_link_info) { 4743 err = link->ops->fill_link_info(link, &info); 4744 if (err) 4745 return err; 4746 } 4747 4748 if (copy_to_user(uinfo, &info, info_len) || 4749 put_user(info_len, &uattr->info.info_len)) 4750 return -EFAULT; 4751 4752 return 0; 4753 } 4754 4755 4756 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 4757 4758 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 4759 union bpf_attr __user *uattr) 4760 { 4761 int ufd = attr->info.bpf_fd; 4762 struct fd f; 4763 int err; 4764 4765 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 4766 return -EINVAL; 4767 4768 f = fdget(ufd); 4769 if (!f.file) 4770 return -EBADFD; 4771 4772 if (f.file->f_op == &bpf_prog_fops) 4773 err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr, 4774 uattr); 4775 else if (f.file->f_op == &bpf_map_fops) 4776 err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr, 4777 uattr); 4778 else if (f.file->f_op == &btf_fops) 4779 err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr); 4780 else if (f.file->f_op == &bpf_link_fops) 4781 err = bpf_link_get_info_by_fd(f.file, f.file->private_data, 4782 attr, uattr); 4783 else 4784 err = -EINVAL; 4785 4786 fdput(f); 4787 return err; 4788 } 4789 4790 #define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size 4791 4792 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) 4793 { 4794 if (CHECK_ATTR(BPF_BTF_LOAD)) 4795 return -EINVAL; 4796 4797 if (!bpf_capable()) 4798 return -EPERM; 4799 4800 return btf_new_fd(attr, uattr, uattr_size); 4801 } 4802 4803 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id 4804 4805 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 4806 { 4807 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 4808 return -EINVAL; 4809 4810 if (!capable(CAP_SYS_ADMIN)) 4811 return -EPERM; 4812 4813 return btf_get_fd_by_id(attr->btf_id); 4814 } 4815 4816 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 4817 union bpf_attr __user *uattr, 4818 u32 prog_id, u32 fd_type, 4819 const char *buf, u64 probe_offset, 4820 u64 probe_addr) 4821 { 4822 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 4823 u32 len = buf ? strlen(buf) : 0, input_len; 4824 int err = 0; 4825 4826 if (put_user(len, &uattr->task_fd_query.buf_len)) 4827 return -EFAULT; 4828 input_len = attr->task_fd_query.buf_len; 4829 if (input_len && ubuf) { 4830 if (!len) { 4831 /* nothing to copy, just make ubuf NULL terminated */ 4832 char zero = '\0'; 4833 4834 if (put_user(zero, ubuf)) 4835 return -EFAULT; 4836 } else if (input_len >= len + 1) { 4837 /* ubuf can hold the string with NULL terminator */ 4838 if (copy_to_user(ubuf, buf, len + 1)) 4839 return -EFAULT; 4840 } else { 4841 /* ubuf cannot hold the string with NULL terminator, 4842 * do a partial copy with NULL terminator. 4843 */ 4844 char zero = '\0'; 4845 4846 err = -ENOSPC; 4847 if (copy_to_user(ubuf, buf, input_len - 1)) 4848 return -EFAULT; 4849 if (put_user(zero, ubuf + input_len - 1)) 4850 return -EFAULT; 4851 } 4852 } 4853 4854 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 4855 put_user(fd_type, &uattr->task_fd_query.fd_type) || 4856 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 4857 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 4858 return -EFAULT; 4859 4860 return err; 4861 } 4862 4863 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 4864 4865 static int bpf_task_fd_query(const union bpf_attr *attr, 4866 union bpf_attr __user *uattr) 4867 { 4868 pid_t pid = attr->task_fd_query.pid; 4869 u32 fd = attr->task_fd_query.fd; 4870 const struct perf_event *event; 4871 struct task_struct *task; 4872 struct file *file; 4873 int err; 4874 4875 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 4876 return -EINVAL; 4877 4878 if (!capable(CAP_SYS_ADMIN)) 4879 return -EPERM; 4880 4881 if (attr->task_fd_query.flags != 0) 4882 return -EINVAL; 4883 4884 rcu_read_lock(); 4885 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 4886 rcu_read_unlock(); 4887 if (!task) 4888 return -ENOENT; 4889 4890 err = 0; 4891 file = fget_task(task, fd); 4892 put_task_struct(task); 4893 if (!file) 4894 return -EBADF; 4895 4896 if (file->f_op == &bpf_link_fops) { 4897 struct bpf_link *link = file->private_data; 4898 4899 if (link->ops == &bpf_raw_tp_link_lops) { 4900 struct bpf_raw_tp_link *raw_tp = 4901 container_of(link, struct bpf_raw_tp_link, link); 4902 struct bpf_raw_event_map *btp = raw_tp->btp; 4903 4904 err = bpf_task_fd_query_copy(attr, uattr, 4905 raw_tp->link.prog->aux->id, 4906 BPF_FD_TYPE_RAW_TRACEPOINT, 4907 btp->tp->name, 0, 0); 4908 goto put_file; 4909 } 4910 goto out_not_supp; 4911 } 4912 4913 event = perf_get_event(file); 4914 if (!IS_ERR(event)) { 4915 u64 probe_offset, probe_addr; 4916 u32 prog_id, fd_type; 4917 const char *buf; 4918 4919 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 4920 &buf, &probe_offset, 4921 &probe_addr, NULL); 4922 if (!err) 4923 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 4924 fd_type, buf, 4925 probe_offset, 4926 probe_addr); 4927 goto put_file; 4928 } 4929 4930 out_not_supp: 4931 err = -ENOTSUPP; 4932 put_file: 4933 fput(file); 4934 return err; 4935 } 4936 4937 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 4938 4939 #define BPF_DO_BATCH(fn, ...) \ 4940 do { \ 4941 if (!fn) { \ 4942 err = -ENOTSUPP; \ 4943 goto err_put; \ 4944 } \ 4945 err = fn(__VA_ARGS__); \ 4946 } while (0) 4947 4948 static int bpf_map_do_batch(const union bpf_attr *attr, 4949 union bpf_attr __user *uattr, 4950 int cmd) 4951 { 4952 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 4953 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 4954 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 4955 struct bpf_map *map; 4956 int err, ufd; 4957 struct fd f; 4958 4959 if (CHECK_ATTR(BPF_MAP_BATCH)) 4960 return -EINVAL; 4961 4962 ufd = attr->batch.map_fd; 4963 f = fdget(ufd); 4964 map = __bpf_map_get(f); 4965 if (IS_ERR(map)) 4966 return PTR_ERR(map); 4967 if (has_write) 4968 bpf_map_write_active_inc(map); 4969 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 4970 err = -EPERM; 4971 goto err_put; 4972 } 4973 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 4974 err = -EPERM; 4975 goto err_put; 4976 } 4977 4978 if (cmd == BPF_MAP_LOOKUP_BATCH) 4979 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 4980 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 4981 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 4982 else if (cmd == BPF_MAP_UPDATE_BATCH) 4983 BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr); 4984 else 4985 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 4986 err_put: 4987 if (has_write) 4988 bpf_map_write_active_dec(map); 4989 fdput(f); 4990 return err; 4991 } 4992 4993 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 4994 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 4995 { 4996 struct bpf_prog *prog; 4997 int ret; 4998 4999 if (CHECK_ATTR(BPF_LINK_CREATE)) 5000 return -EINVAL; 5001 5002 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5003 return bpf_struct_ops_link_create(attr); 5004 5005 prog = bpf_prog_get(attr->link_create.prog_fd); 5006 if (IS_ERR(prog)) 5007 return PTR_ERR(prog); 5008 5009 ret = bpf_prog_attach_check_attach_type(prog, 5010 attr->link_create.attach_type); 5011 if (ret) 5012 goto out; 5013 5014 switch (prog->type) { 5015 case BPF_PROG_TYPE_CGROUP_SKB: 5016 case BPF_PROG_TYPE_CGROUP_SOCK: 5017 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5018 case BPF_PROG_TYPE_SOCK_OPS: 5019 case BPF_PROG_TYPE_CGROUP_DEVICE: 5020 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5021 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5022 ret = cgroup_bpf_link_attach(attr, prog); 5023 break; 5024 case BPF_PROG_TYPE_EXT: 5025 ret = bpf_tracing_prog_attach(prog, 5026 attr->link_create.target_fd, 5027 attr->link_create.target_btf_id, 5028 attr->link_create.tracing.cookie); 5029 break; 5030 case BPF_PROG_TYPE_LSM: 5031 case BPF_PROG_TYPE_TRACING: 5032 if (attr->link_create.attach_type != prog->expected_attach_type) { 5033 ret = -EINVAL; 5034 goto out; 5035 } 5036 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5037 ret = bpf_raw_tp_link_attach(prog, NULL); 5038 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5039 ret = bpf_iter_link_attach(attr, uattr, prog); 5040 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5041 ret = cgroup_bpf_link_attach(attr, prog); 5042 else 5043 ret = bpf_tracing_prog_attach(prog, 5044 attr->link_create.target_fd, 5045 attr->link_create.target_btf_id, 5046 attr->link_create.tracing.cookie); 5047 break; 5048 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5049 case BPF_PROG_TYPE_SK_LOOKUP: 5050 ret = netns_bpf_link_create(attr, prog); 5051 break; 5052 #ifdef CONFIG_NET 5053 case BPF_PROG_TYPE_XDP: 5054 ret = bpf_xdp_link_attach(attr, prog); 5055 break; 5056 case BPF_PROG_TYPE_SCHED_CLS: 5057 ret = tcx_link_attach(attr, prog); 5058 break; 5059 case BPF_PROG_TYPE_NETFILTER: 5060 ret = bpf_nf_link_attach(attr, prog); 5061 break; 5062 #endif 5063 case BPF_PROG_TYPE_PERF_EVENT: 5064 case BPF_PROG_TYPE_TRACEPOINT: 5065 ret = bpf_perf_link_attach(attr, prog); 5066 break; 5067 case BPF_PROG_TYPE_KPROBE: 5068 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5069 ret = bpf_perf_link_attach(attr, prog); 5070 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI) 5071 ret = bpf_kprobe_multi_link_attach(attr, prog); 5072 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI) 5073 ret = bpf_uprobe_multi_link_attach(attr, prog); 5074 break; 5075 default: 5076 ret = -EINVAL; 5077 } 5078 5079 out: 5080 if (ret < 0) 5081 bpf_prog_put(prog); 5082 return ret; 5083 } 5084 5085 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5086 { 5087 struct bpf_map *new_map, *old_map = NULL; 5088 int ret; 5089 5090 new_map = bpf_map_get(attr->link_update.new_map_fd); 5091 if (IS_ERR(new_map)) 5092 return PTR_ERR(new_map); 5093 5094 if (attr->link_update.flags & BPF_F_REPLACE) { 5095 old_map = bpf_map_get(attr->link_update.old_map_fd); 5096 if (IS_ERR(old_map)) { 5097 ret = PTR_ERR(old_map); 5098 goto out_put; 5099 } 5100 } else if (attr->link_update.old_map_fd) { 5101 ret = -EINVAL; 5102 goto out_put; 5103 } 5104 5105 ret = link->ops->update_map(link, new_map, old_map); 5106 5107 if (old_map) 5108 bpf_map_put(old_map); 5109 out_put: 5110 bpf_map_put(new_map); 5111 return ret; 5112 } 5113 5114 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5115 5116 static int link_update(union bpf_attr *attr) 5117 { 5118 struct bpf_prog *old_prog = NULL, *new_prog; 5119 struct bpf_link *link; 5120 u32 flags; 5121 int ret; 5122 5123 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5124 return -EINVAL; 5125 5126 flags = attr->link_update.flags; 5127 if (flags & ~BPF_F_REPLACE) 5128 return -EINVAL; 5129 5130 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5131 if (IS_ERR(link)) 5132 return PTR_ERR(link); 5133 5134 if (link->ops->update_map) { 5135 ret = link_update_map(link, attr); 5136 goto out_put_link; 5137 } 5138 5139 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5140 if (IS_ERR(new_prog)) { 5141 ret = PTR_ERR(new_prog); 5142 goto out_put_link; 5143 } 5144 5145 if (flags & BPF_F_REPLACE) { 5146 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5147 if (IS_ERR(old_prog)) { 5148 ret = PTR_ERR(old_prog); 5149 old_prog = NULL; 5150 goto out_put_progs; 5151 } 5152 } else if (attr->link_update.old_prog_fd) { 5153 ret = -EINVAL; 5154 goto out_put_progs; 5155 } 5156 5157 if (link->ops->update_prog) 5158 ret = link->ops->update_prog(link, new_prog, old_prog); 5159 else 5160 ret = -EINVAL; 5161 5162 out_put_progs: 5163 if (old_prog) 5164 bpf_prog_put(old_prog); 5165 if (ret) 5166 bpf_prog_put(new_prog); 5167 out_put_link: 5168 bpf_link_put_direct(link); 5169 return ret; 5170 } 5171 5172 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5173 5174 static int link_detach(union bpf_attr *attr) 5175 { 5176 struct bpf_link *link; 5177 int ret; 5178 5179 if (CHECK_ATTR(BPF_LINK_DETACH)) 5180 return -EINVAL; 5181 5182 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 5183 if (IS_ERR(link)) 5184 return PTR_ERR(link); 5185 5186 if (link->ops->detach) 5187 ret = link->ops->detach(link); 5188 else 5189 ret = -EOPNOTSUPP; 5190 5191 bpf_link_put_direct(link); 5192 return ret; 5193 } 5194 5195 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 5196 { 5197 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 5198 } 5199 5200 struct bpf_link *bpf_link_by_id(u32 id) 5201 { 5202 struct bpf_link *link; 5203 5204 if (!id) 5205 return ERR_PTR(-ENOENT); 5206 5207 spin_lock_bh(&link_idr_lock); 5208 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 5209 link = idr_find(&link_idr, id); 5210 if (link) { 5211 if (link->id) 5212 link = bpf_link_inc_not_zero(link); 5213 else 5214 link = ERR_PTR(-EAGAIN); 5215 } else { 5216 link = ERR_PTR(-ENOENT); 5217 } 5218 spin_unlock_bh(&link_idr_lock); 5219 return link; 5220 } 5221 5222 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 5223 { 5224 struct bpf_link *link; 5225 5226 spin_lock_bh(&link_idr_lock); 5227 again: 5228 link = idr_get_next(&link_idr, id); 5229 if (link) { 5230 link = bpf_link_inc_not_zero(link); 5231 if (IS_ERR(link)) { 5232 (*id)++; 5233 goto again; 5234 } 5235 } 5236 spin_unlock_bh(&link_idr_lock); 5237 5238 return link; 5239 } 5240 5241 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 5242 5243 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 5244 { 5245 struct bpf_link *link; 5246 u32 id = attr->link_id; 5247 int fd; 5248 5249 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 5250 return -EINVAL; 5251 5252 if (!capable(CAP_SYS_ADMIN)) 5253 return -EPERM; 5254 5255 link = bpf_link_by_id(id); 5256 if (IS_ERR(link)) 5257 return PTR_ERR(link); 5258 5259 fd = bpf_link_new_fd(link); 5260 if (fd < 0) 5261 bpf_link_put_direct(link); 5262 5263 return fd; 5264 } 5265 5266 DEFINE_MUTEX(bpf_stats_enabled_mutex); 5267 5268 static int bpf_stats_release(struct inode *inode, struct file *file) 5269 { 5270 mutex_lock(&bpf_stats_enabled_mutex); 5271 static_key_slow_dec(&bpf_stats_enabled_key.key); 5272 mutex_unlock(&bpf_stats_enabled_mutex); 5273 return 0; 5274 } 5275 5276 static const struct file_operations bpf_stats_fops = { 5277 .release = bpf_stats_release, 5278 }; 5279 5280 static int bpf_enable_runtime_stats(void) 5281 { 5282 int fd; 5283 5284 mutex_lock(&bpf_stats_enabled_mutex); 5285 5286 /* Set a very high limit to avoid overflow */ 5287 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 5288 mutex_unlock(&bpf_stats_enabled_mutex); 5289 return -EBUSY; 5290 } 5291 5292 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 5293 if (fd >= 0) 5294 static_key_slow_inc(&bpf_stats_enabled_key.key); 5295 5296 mutex_unlock(&bpf_stats_enabled_mutex); 5297 return fd; 5298 } 5299 5300 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 5301 5302 static int bpf_enable_stats(union bpf_attr *attr) 5303 { 5304 5305 if (CHECK_ATTR(BPF_ENABLE_STATS)) 5306 return -EINVAL; 5307 5308 if (!capable(CAP_SYS_ADMIN)) 5309 return -EPERM; 5310 5311 switch (attr->enable_stats.type) { 5312 case BPF_STATS_RUN_TIME: 5313 return bpf_enable_runtime_stats(); 5314 default: 5315 break; 5316 } 5317 return -EINVAL; 5318 } 5319 5320 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 5321 5322 static int bpf_iter_create(union bpf_attr *attr) 5323 { 5324 struct bpf_link *link; 5325 int err; 5326 5327 if (CHECK_ATTR(BPF_ITER_CREATE)) 5328 return -EINVAL; 5329 5330 if (attr->iter_create.flags) 5331 return -EINVAL; 5332 5333 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 5334 if (IS_ERR(link)) 5335 return PTR_ERR(link); 5336 5337 err = bpf_iter_new_fd(link); 5338 bpf_link_put_direct(link); 5339 5340 return err; 5341 } 5342 5343 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 5344 5345 static int bpf_prog_bind_map(union bpf_attr *attr) 5346 { 5347 struct bpf_prog *prog; 5348 struct bpf_map *map; 5349 struct bpf_map **used_maps_old, **used_maps_new; 5350 int i, ret = 0; 5351 5352 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 5353 return -EINVAL; 5354 5355 if (attr->prog_bind_map.flags) 5356 return -EINVAL; 5357 5358 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 5359 if (IS_ERR(prog)) 5360 return PTR_ERR(prog); 5361 5362 map = bpf_map_get(attr->prog_bind_map.map_fd); 5363 if (IS_ERR(map)) { 5364 ret = PTR_ERR(map); 5365 goto out_prog_put; 5366 } 5367 5368 mutex_lock(&prog->aux->used_maps_mutex); 5369 5370 used_maps_old = prog->aux->used_maps; 5371 5372 for (i = 0; i < prog->aux->used_map_cnt; i++) 5373 if (used_maps_old[i] == map) { 5374 bpf_map_put(map); 5375 goto out_unlock; 5376 } 5377 5378 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, 5379 sizeof(used_maps_new[0]), 5380 GFP_KERNEL); 5381 if (!used_maps_new) { 5382 ret = -ENOMEM; 5383 goto out_unlock; 5384 } 5385 5386 /* The bpf program will not access the bpf map, but for the sake of 5387 * simplicity, increase sleepable_refcnt for sleepable program as well. 5388 */ 5389 if (prog->aux->sleepable) 5390 atomic64_inc(&map->sleepable_refcnt); 5391 memcpy(used_maps_new, used_maps_old, 5392 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 5393 used_maps_new[prog->aux->used_map_cnt] = map; 5394 5395 prog->aux->used_map_cnt++; 5396 prog->aux->used_maps = used_maps_new; 5397 5398 kfree(used_maps_old); 5399 5400 out_unlock: 5401 mutex_unlock(&prog->aux->used_maps_mutex); 5402 5403 if (ret) 5404 bpf_map_put(map); 5405 out_prog_put: 5406 bpf_prog_put(prog); 5407 return ret; 5408 } 5409 5410 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size) 5411 { 5412 union bpf_attr attr; 5413 int err; 5414 5415 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 5416 if (err) 5417 return err; 5418 size = min_t(u32, size, sizeof(attr)); 5419 5420 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 5421 memset(&attr, 0, sizeof(attr)); 5422 if (copy_from_bpfptr(&attr, uattr, size) != 0) 5423 return -EFAULT; 5424 5425 err = security_bpf(cmd, &attr, size); 5426 if (err < 0) 5427 return err; 5428 5429 switch (cmd) { 5430 case BPF_MAP_CREATE: 5431 err = map_create(&attr); 5432 break; 5433 case BPF_MAP_LOOKUP_ELEM: 5434 err = map_lookup_elem(&attr); 5435 break; 5436 case BPF_MAP_UPDATE_ELEM: 5437 err = map_update_elem(&attr, uattr); 5438 break; 5439 case BPF_MAP_DELETE_ELEM: 5440 err = map_delete_elem(&attr, uattr); 5441 break; 5442 case BPF_MAP_GET_NEXT_KEY: 5443 err = map_get_next_key(&attr); 5444 break; 5445 case BPF_MAP_FREEZE: 5446 err = map_freeze(&attr); 5447 break; 5448 case BPF_PROG_LOAD: 5449 err = bpf_prog_load(&attr, uattr, size); 5450 break; 5451 case BPF_OBJ_PIN: 5452 err = bpf_obj_pin(&attr); 5453 break; 5454 case BPF_OBJ_GET: 5455 err = bpf_obj_get(&attr); 5456 break; 5457 case BPF_PROG_ATTACH: 5458 err = bpf_prog_attach(&attr); 5459 break; 5460 case BPF_PROG_DETACH: 5461 err = bpf_prog_detach(&attr); 5462 break; 5463 case BPF_PROG_QUERY: 5464 err = bpf_prog_query(&attr, uattr.user); 5465 break; 5466 case BPF_PROG_TEST_RUN: 5467 err = bpf_prog_test_run(&attr, uattr.user); 5468 break; 5469 case BPF_PROG_GET_NEXT_ID: 5470 err = bpf_obj_get_next_id(&attr, uattr.user, 5471 &prog_idr, &prog_idr_lock); 5472 break; 5473 case BPF_MAP_GET_NEXT_ID: 5474 err = bpf_obj_get_next_id(&attr, uattr.user, 5475 &map_idr, &map_idr_lock); 5476 break; 5477 case BPF_BTF_GET_NEXT_ID: 5478 err = bpf_obj_get_next_id(&attr, uattr.user, 5479 &btf_idr, &btf_idr_lock); 5480 break; 5481 case BPF_PROG_GET_FD_BY_ID: 5482 err = bpf_prog_get_fd_by_id(&attr); 5483 break; 5484 case BPF_MAP_GET_FD_BY_ID: 5485 err = bpf_map_get_fd_by_id(&attr); 5486 break; 5487 case BPF_OBJ_GET_INFO_BY_FD: 5488 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 5489 break; 5490 case BPF_RAW_TRACEPOINT_OPEN: 5491 err = bpf_raw_tracepoint_open(&attr); 5492 break; 5493 case BPF_BTF_LOAD: 5494 err = bpf_btf_load(&attr, uattr, size); 5495 break; 5496 case BPF_BTF_GET_FD_BY_ID: 5497 err = bpf_btf_get_fd_by_id(&attr); 5498 break; 5499 case BPF_TASK_FD_QUERY: 5500 err = bpf_task_fd_query(&attr, uattr.user); 5501 break; 5502 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 5503 err = map_lookup_and_delete_elem(&attr); 5504 break; 5505 case BPF_MAP_LOOKUP_BATCH: 5506 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 5507 break; 5508 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 5509 err = bpf_map_do_batch(&attr, uattr.user, 5510 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 5511 break; 5512 case BPF_MAP_UPDATE_BATCH: 5513 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 5514 break; 5515 case BPF_MAP_DELETE_BATCH: 5516 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 5517 break; 5518 case BPF_LINK_CREATE: 5519 err = link_create(&attr, uattr); 5520 break; 5521 case BPF_LINK_UPDATE: 5522 err = link_update(&attr); 5523 break; 5524 case BPF_LINK_GET_FD_BY_ID: 5525 err = bpf_link_get_fd_by_id(&attr); 5526 break; 5527 case BPF_LINK_GET_NEXT_ID: 5528 err = bpf_obj_get_next_id(&attr, uattr.user, 5529 &link_idr, &link_idr_lock); 5530 break; 5531 case BPF_ENABLE_STATS: 5532 err = bpf_enable_stats(&attr); 5533 break; 5534 case BPF_ITER_CREATE: 5535 err = bpf_iter_create(&attr); 5536 break; 5537 case BPF_LINK_DETACH: 5538 err = link_detach(&attr); 5539 break; 5540 case BPF_PROG_BIND_MAP: 5541 err = bpf_prog_bind_map(&attr); 5542 break; 5543 default: 5544 err = -EINVAL; 5545 break; 5546 } 5547 5548 return err; 5549 } 5550 5551 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) 5552 { 5553 return __sys_bpf(cmd, USER_BPFPTR(uattr), size); 5554 } 5555 5556 static bool syscall_prog_is_valid_access(int off, int size, 5557 enum bpf_access_type type, 5558 const struct bpf_prog *prog, 5559 struct bpf_insn_access_aux *info) 5560 { 5561 if (off < 0 || off >= U16_MAX) 5562 return false; 5563 if (off % size != 0) 5564 return false; 5565 return true; 5566 } 5567 5568 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 5569 { 5570 switch (cmd) { 5571 case BPF_MAP_CREATE: 5572 case BPF_MAP_DELETE_ELEM: 5573 case BPF_MAP_UPDATE_ELEM: 5574 case BPF_MAP_FREEZE: 5575 case BPF_MAP_GET_FD_BY_ID: 5576 case BPF_PROG_LOAD: 5577 case BPF_BTF_LOAD: 5578 case BPF_LINK_CREATE: 5579 case BPF_RAW_TRACEPOINT_OPEN: 5580 break; 5581 default: 5582 return -EINVAL; 5583 } 5584 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); 5585 } 5586 5587 5588 /* To shut up -Wmissing-prototypes. 5589 * This function is used by the kernel light skeleton 5590 * to load bpf programs when modules are loaded or during kernel boot. 5591 * See tools/lib/bpf/skel_internal.h 5592 */ 5593 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 5594 5595 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 5596 { 5597 struct bpf_prog * __maybe_unused prog; 5598 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 5599 5600 switch (cmd) { 5601 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 5602 case BPF_PROG_TEST_RUN: 5603 if (attr->test.data_in || attr->test.data_out || 5604 attr->test.ctx_out || attr->test.duration || 5605 attr->test.repeat || attr->test.flags) 5606 return -EINVAL; 5607 5608 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 5609 if (IS_ERR(prog)) 5610 return PTR_ERR(prog); 5611 5612 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 5613 attr->test.ctx_size_in > U16_MAX) { 5614 bpf_prog_put(prog); 5615 return -EINVAL; 5616 } 5617 5618 run_ctx.bpf_cookie = 0; 5619 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 5620 /* recursion detected */ 5621 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 5622 bpf_prog_put(prog); 5623 return -EBUSY; 5624 } 5625 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 5626 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 5627 &run_ctx); 5628 bpf_prog_put(prog); 5629 return 0; 5630 #endif 5631 default: 5632 return ____bpf_sys_bpf(cmd, attr, size); 5633 } 5634 } 5635 EXPORT_SYMBOL(kern_sys_bpf); 5636 5637 static const struct bpf_func_proto bpf_sys_bpf_proto = { 5638 .func = bpf_sys_bpf, 5639 .gpl_only = false, 5640 .ret_type = RET_INTEGER, 5641 .arg1_type = ARG_ANYTHING, 5642 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 5643 .arg3_type = ARG_CONST_SIZE, 5644 }; 5645 5646 const struct bpf_func_proto * __weak 5647 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5648 { 5649 return bpf_base_func_proto(func_id); 5650 } 5651 5652 BPF_CALL_1(bpf_sys_close, u32, fd) 5653 { 5654 /* When bpf program calls this helper there should not be 5655 * an fdget() without matching completed fdput(). 5656 * This helper is allowed in the following callchain only: 5657 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 5658 */ 5659 return close_fd(fd); 5660 } 5661 5662 static const struct bpf_func_proto bpf_sys_close_proto = { 5663 .func = bpf_sys_close, 5664 .gpl_only = false, 5665 .ret_type = RET_INTEGER, 5666 .arg1_type = ARG_ANYTHING, 5667 }; 5668 5669 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 5670 { 5671 *res = 0; 5672 if (flags) 5673 return -EINVAL; 5674 5675 if (name_sz <= 1 || name[name_sz - 1]) 5676 return -EINVAL; 5677 5678 if (!bpf_dump_raw_ok(current_cred())) 5679 return -EPERM; 5680 5681 *res = kallsyms_lookup_name(name); 5682 return *res ? 0 : -ENOENT; 5683 } 5684 5685 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 5686 .func = bpf_kallsyms_lookup_name, 5687 .gpl_only = false, 5688 .ret_type = RET_INTEGER, 5689 .arg1_type = ARG_PTR_TO_MEM, 5690 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 5691 .arg3_type = ARG_ANYTHING, 5692 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 5693 .arg4_size = sizeof(u64), 5694 }; 5695 5696 static const struct bpf_func_proto * 5697 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5698 { 5699 switch (func_id) { 5700 case BPF_FUNC_sys_bpf: 5701 return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto; 5702 case BPF_FUNC_btf_find_by_name_kind: 5703 return &bpf_btf_find_by_name_kind_proto; 5704 case BPF_FUNC_sys_close: 5705 return &bpf_sys_close_proto; 5706 case BPF_FUNC_kallsyms_lookup_name: 5707 return &bpf_kallsyms_lookup_name_proto; 5708 default: 5709 return tracing_prog_func_proto(func_id, prog); 5710 } 5711 } 5712 5713 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 5714 .get_func_proto = syscall_prog_func_proto, 5715 .is_valid_access = syscall_prog_is_valid_access, 5716 }; 5717 5718 const struct bpf_prog_ops bpf_syscall_prog_ops = { 5719 .test_run = bpf_prog_test_run_syscall, 5720 }; 5721 5722 #ifdef CONFIG_SYSCTL 5723 static int bpf_stats_handler(struct ctl_table *table, int write, 5724 void *buffer, size_t *lenp, loff_t *ppos) 5725 { 5726 struct static_key *key = (struct static_key *)table->data; 5727 static int saved_val; 5728 int val, ret; 5729 struct ctl_table tmp = { 5730 .data = &val, 5731 .maxlen = sizeof(val), 5732 .mode = table->mode, 5733 .extra1 = SYSCTL_ZERO, 5734 .extra2 = SYSCTL_ONE, 5735 }; 5736 5737 if (write && !capable(CAP_SYS_ADMIN)) 5738 return -EPERM; 5739 5740 mutex_lock(&bpf_stats_enabled_mutex); 5741 val = saved_val; 5742 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5743 if (write && !ret && val != saved_val) { 5744 if (val) 5745 static_key_slow_inc(key); 5746 else 5747 static_key_slow_dec(key); 5748 saved_val = val; 5749 } 5750 mutex_unlock(&bpf_stats_enabled_mutex); 5751 return ret; 5752 } 5753 5754 void __weak unpriv_ebpf_notify(int new_state) 5755 { 5756 } 5757 5758 static int bpf_unpriv_handler(struct ctl_table *table, int write, 5759 void *buffer, size_t *lenp, loff_t *ppos) 5760 { 5761 int ret, unpriv_enable = *(int *)table->data; 5762 bool locked_state = unpriv_enable == 1; 5763 struct ctl_table tmp = *table; 5764 5765 if (write && !capable(CAP_SYS_ADMIN)) 5766 return -EPERM; 5767 5768 tmp.data = &unpriv_enable; 5769 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5770 if (write && !ret) { 5771 if (locked_state && unpriv_enable != 1) 5772 return -EPERM; 5773 *(int *)table->data = unpriv_enable; 5774 } 5775 5776 if (write) 5777 unpriv_ebpf_notify(unpriv_enable); 5778 5779 return ret; 5780 } 5781 5782 static struct ctl_table bpf_syscall_table[] = { 5783 { 5784 .procname = "unprivileged_bpf_disabled", 5785 .data = &sysctl_unprivileged_bpf_disabled, 5786 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 5787 .mode = 0644, 5788 .proc_handler = bpf_unpriv_handler, 5789 .extra1 = SYSCTL_ZERO, 5790 .extra2 = SYSCTL_TWO, 5791 }, 5792 { 5793 .procname = "bpf_stats_enabled", 5794 .data = &bpf_stats_enabled_key.key, 5795 .mode = 0644, 5796 .proc_handler = bpf_stats_handler, 5797 }, 5798 { } 5799 }; 5800 5801 static int __init bpf_syscall_sysctl_init(void) 5802 { 5803 register_sysctl_init("kernel", bpf_syscall_table); 5804 return 0; 5805 } 5806 late_initcall(bpf_syscall_sysctl_init); 5807 #endif /* CONFIG_SYSCTL */ 5808