1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 */ 4 #include <linux/bpf.h> 5 #include <linux/bpf-cgroup.h> 6 #include <linux/bpf_trace.h> 7 #include <linux/bpf_lirc.h> 8 #include <linux/bpf_verifier.h> 9 #include <linux/bsearch.h> 10 #include <linux/btf.h> 11 #include <linux/syscalls.h> 12 #include <linux/slab.h> 13 #include <linux/sched/signal.h> 14 #include <linux/vmalloc.h> 15 #include <linux/mmzone.h> 16 #include <linux/anon_inodes.h> 17 #include <linux/fdtable.h> 18 #include <linux/file.h> 19 #include <linux/fs.h> 20 #include <linux/license.h> 21 #include <linux/filter.h> 22 #include <linux/kernel.h> 23 #include <linux/idr.h> 24 #include <linux/cred.h> 25 #include <linux/timekeeping.h> 26 #include <linux/ctype.h> 27 #include <linux/nospec.h> 28 #include <linux/audit.h> 29 #include <uapi/linux/btf.h> 30 #include <linux/pgtable.h> 31 #include <linux/bpf_lsm.h> 32 #include <linux/poll.h> 33 #include <linux/sort.h> 34 #include <linux/bpf-netns.h> 35 #include <linux/rcupdate_trace.h> 36 #include <linux/memcontrol.h> 37 #include <linux/trace_events.h> 38 39 #include <net/netfilter/nf_bpf_link.h> 40 #include <net/netkit.h> 41 #include <net/tcx.h> 42 43 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ 44 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ 45 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 46 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) 47 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) 48 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ 49 IS_FD_HASH(map)) 50 51 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) 52 53 DEFINE_PER_CPU(int, bpf_prog_active); 54 static DEFINE_IDR(prog_idr); 55 static DEFINE_SPINLOCK(prog_idr_lock); 56 static DEFINE_IDR(map_idr); 57 static DEFINE_SPINLOCK(map_idr_lock); 58 static DEFINE_IDR(link_idr); 59 static DEFINE_SPINLOCK(link_idr_lock); 60 61 int sysctl_unprivileged_bpf_disabled __read_mostly = 62 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; 63 64 static const struct bpf_map_ops * const bpf_map_types[] = { 65 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 66 #define BPF_MAP_TYPE(_id, _ops) \ 67 [_id] = &_ops, 68 #define BPF_LINK_TYPE(_id, _name) 69 #include <linux/bpf_types.h> 70 #undef BPF_PROG_TYPE 71 #undef BPF_MAP_TYPE 72 #undef BPF_LINK_TYPE 73 }; 74 75 /* 76 * If we're handed a bigger struct than we know of, ensure all the unknown bits 77 * are 0 - i.e. new user-space does not rely on any kernel feature extensions 78 * we don't know about yet. 79 * 80 * There is a ToCToU between this function call and the following 81 * copy_from_user() call. However, this is not a concern since this function is 82 * meant to be a future-proofing of bits. 83 */ 84 int bpf_check_uarg_tail_zero(bpfptr_t uaddr, 85 size_t expected_size, 86 size_t actual_size) 87 { 88 int res; 89 90 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ 91 return -E2BIG; 92 93 if (actual_size <= expected_size) 94 return 0; 95 96 if (uaddr.is_kernel) 97 res = memchr_inv(uaddr.kernel + expected_size, 0, 98 actual_size - expected_size) == NULL; 99 else 100 res = check_zeroed_user(uaddr.user + expected_size, 101 actual_size - expected_size); 102 if (res < 0) 103 return res; 104 return res ? 0 : -E2BIG; 105 } 106 107 const struct bpf_map_ops bpf_map_offload_ops = { 108 .map_meta_equal = bpf_map_meta_equal, 109 .map_alloc = bpf_map_offload_map_alloc, 110 .map_free = bpf_map_offload_map_free, 111 .map_check_btf = map_check_no_btf, 112 .map_mem_usage = bpf_map_offload_map_mem_usage, 113 }; 114 115 static void bpf_map_write_active_inc(struct bpf_map *map) 116 { 117 atomic64_inc(&map->writecnt); 118 } 119 120 static void bpf_map_write_active_dec(struct bpf_map *map) 121 { 122 atomic64_dec(&map->writecnt); 123 } 124 125 bool bpf_map_write_active(const struct bpf_map *map) 126 { 127 return atomic64_read(&map->writecnt) != 0; 128 } 129 130 static u32 bpf_map_value_size(const struct bpf_map *map) 131 { 132 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 133 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 134 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || 135 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) 136 return round_up(map->value_size, 8) * num_possible_cpus(); 137 else if (IS_FD_MAP(map)) 138 return sizeof(u32); 139 else 140 return map->value_size; 141 } 142 143 static void maybe_wait_bpf_programs(struct bpf_map *map) 144 { 145 /* Wait for any running non-sleepable BPF programs to complete so that 146 * userspace, when we return to it, knows that all non-sleepable 147 * programs that could be running use the new map value. For sleepable 148 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait 149 * for the completions of these programs, but considering the waiting 150 * time can be very long and userspace may think it will hang forever, 151 * so don't handle sleepable BPF programs now. 152 */ 153 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || 154 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 155 synchronize_rcu(); 156 } 157 158 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, 159 void *key, void *value, __u64 flags) 160 { 161 int err; 162 163 /* Need to create a kthread, thus must support schedule */ 164 if (bpf_map_is_offloaded(map)) { 165 return bpf_map_offload_update_elem(map, key, value, flags); 166 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || 167 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 168 return map->ops->map_update_elem(map, key, value, flags); 169 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || 170 map->map_type == BPF_MAP_TYPE_SOCKMAP) { 171 return sock_map_update_elem_sys(map, key, value, flags); 172 } else if (IS_FD_PROG_ARRAY(map)) { 173 return bpf_fd_array_map_update_elem(map, map_file, key, value, 174 flags); 175 } 176 177 bpf_disable_instrumentation(); 178 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 179 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 180 err = bpf_percpu_hash_update(map, key, value, flags); 181 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 182 err = bpf_percpu_array_update(map, key, value, flags); 183 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 184 err = bpf_percpu_cgroup_storage_update(map, key, value, 185 flags); 186 } else if (IS_FD_ARRAY(map)) { 187 err = bpf_fd_array_map_update_elem(map, map_file, key, value, 188 flags); 189 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 190 err = bpf_fd_htab_map_update_elem(map, map_file, key, value, 191 flags); 192 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 193 /* rcu_read_lock() is not needed */ 194 err = bpf_fd_reuseport_array_update_elem(map, key, value, 195 flags); 196 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 197 map->map_type == BPF_MAP_TYPE_STACK || 198 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 199 err = map->ops->map_push_elem(map, value, flags); 200 } else { 201 rcu_read_lock(); 202 err = map->ops->map_update_elem(map, key, value, flags); 203 rcu_read_unlock(); 204 } 205 bpf_enable_instrumentation(); 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(); 266 267 return err; 268 } 269 270 /* Please, do not use this function outside from the map creation path 271 * (e.g. in map update path) without taking care of setting the active 272 * memory cgroup (see at bpf_map_kmalloc_node() for example). 273 */ 274 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) 275 { 276 /* We really just want to fail instead of triggering OOM killer 277 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, 278 * which is used for lower order allocation requests. 279 * 280 * It has been observed that higher order allocation requests done by 281 * vmalloc with __GFP_NORETRY being set might fail due to not trying 282 * to reclaim memory from the page cache, thus we set 283 * __GFP_RETRY_MAYFAIL to avoid such situations. 284 */ 285 286 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO); 287 unsigned int flags = 0; 288 unsigned long align = 1; 289 void *area; 290 291 if (size >= SIZE_MAX) 292 return NULL; 293 294 /* kmalloc()'ed memory can't be mmap()'ed */ 295 if (mmapable) { 296 BUG_ON(!PAGE_ALIGNED(size)); 297 align = SHMLBA; 298 flags = VM_USERMAP; 299 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { 300 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, 301 numa_node); 302 if (area != NULL) 303 return area; 304 } 305 306 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 307 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, 308 flags, numa_node, __builtin_return_address(0)); 309 } 310 311 void *bpf_map_area_alloc(u64 size, int numa_node) 312 { 313 return __bpf_map_area_alloc(size, numa_node, false); 314 } 315 316 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) 317 { 318 return __bpf_map_area_alloc(size, numa_node, true); 319 } 320 321 void bpf_map_area_free(void *area) 322 { 323 kvfree(area); 324 } 325 326 static u32 bpf_map_flags_retain_permanent(u32 flags) 327 { 328 /* Some map creation flags are not tied to the map object but 329 * rather to the map fd instead, so they have no meaning upon 330 * map object inspection since multiple file descriptors with 331 * different (access) properties can exist here. Thus, given 332 * this has zero meaning for the map itself, lets clear these 333 * from here. 334 */ 335 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); 336 } 337 338 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) 339 { 340 map->map_type = attr->map_type; 341 map->key_size = attr->key_size; 342 map->value_size = attr->value_size; 343 map->max_entries = attr->max_entries; 344 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); 345 map->numa_node = bpf_map_attr_numa_node(attr); 346 map->map_extra = attr->map_extra; 347 } 348 349 static int bpf_map_alloc_id(struct bpf_map *map) 350 { 351 int id; 352 353 idr_preload(GFP_KERNEL); 354 spin_lock_bh(&map_idr_lock); 355 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); 356 if (id > 0) 357 map->id = id; 358 spin_unlock_bh(&map_idr_lock); 359 idr_preload_end(); 360 361 if (WARN_ON_ONCE(!id)) 362 return -ENOSPC; 363 364 return id > 0 ? 0 : id; 365 } 366 367 void bpf_map_free_id(struct bpf_map *map) 368 { 369 unsigned long flags; 370 371 /* Offloaded maps are removed from the IDR store when their device 372 * disappears - even if someone holds an fd to them they are unusable, 373 * the memory is gone, all ops will fail; they are simply waiting for 374 * refcnt to drop to be freed. 375 */ 376 if (!map->id) 377 return; 378 379 spin_lock_irqsave(&map_idr_lock, flags); 380 381 idr_remove(&map_idr, map->id); 382 map->id = 0; 383 384 spin_unlock_irqrestore(&map_idr_lock, flags); 385 } 386 387 #ifdef CONFIG_MEMCG_KMEM 388 static void bpf_map_save_memcg(struct bpf_map *map) 389 { 390 /* Currently if a map is created by a process belonging to the root 391 * memory cgroup, get_obj_cgroup_from_current() will return NULL. 392 * So we have to check map->objcg for being NULL each time it's 393 * being used. 394 */ 395 if (memcg_bpf_enabled()) 396 map->objcg = get_obj_cgroup_from_current(); 397 } 398 399 static void bpf_map_release_memcg(struct bpf_map *map) 400 { 401 if (map->objcg) 402 obj_cgroup_put(map->objcg); 403 } 404 405 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) 406 { 407 if (map->objcg) 408 return get_mem_cgroup_from_objcg(map->objcg); 409 410 return root_mem_cgroup; 411 } 412 413 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, 414 int node) 415 { 416 struct mem_cgroup *memcg, *old_memcg; 417 void *ptr; 418 419 memcg = bpf_map_get_memcg(map); 420 old_memcg = set_active_memcg(memcg); 421 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); 422 set_active_memcg(old_memcg); 423 mem_cgroup_put(memcg); 424 425 return ptr; 426 } 427 428 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) 429 { 430 struct mem_cgroup *memcg, *old_memcg; 431 void *ptr; 432 433 memcg = bpf_map_get_memcg(map); 434 old_memcg = set_active_memcg(memcg); 435 ptr = kzalloc(size, flags | __GFP_ACCOUNT); 436 set_active_memcg(old_memcg); 437 mem_cgroup_put(memcg); 438 439 return ptr; 440 } 441 442 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, 443 gfp_t flags) 444 { 445 struct mem_cgroup *memcg, *old_memcg; 446 void *ptr; 447 448 memcg = bpf_map_get_memcg(map); 449 old_memcg = set_active_memcg(memcg); 450 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); 451 set_active_memcg(old_memcg); 452 mem_cgroup_put(memcg); 453 454 return ptr; 455 } 456 457 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, 458 size_t align, gfp_t flags) 459 { 460 struct mem_cgroup *memcg, *old_memcg; 461 void __percpu *ptr; 462 463 memcg = bpf_map_get_memcg(map); 464 old_memcg = set_active_memcg(memcg); 465 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); 466 set_active_memcg(old_memcg); 467 mem_cgroup_put(memcg); 468 469 return ptr; 470 } 471 472 #else 473 static void bpf_map_save_memcg(struct bpf_map *map) 474 { 475 } 476 477 static void bpf_map_release_memcg(struct bpf_map *map) 478 { 479 } 480 #endif 481 482 static int btf_field_cmp(const void *a, const void *b) 483 { 484 const struct btf_field *f1 = a, *f2 = b; 485 486 if (f1->offset < f2->offset) 487 return -1; 488 else if (f1->offset > f2->offset) 489 return 1; 490 return 0; 491 } 492 493 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 494 u32 field_mask) 495 { 496 struct btf_field *field; 497 498 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 499 return NULL; 500 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 501 if (!field || !(field->type & field_mask)) 502 return NULL; 503 return field; 504 } 505 506 void btf_record_free(struct btf_record *rec) 507 { 508 int i; 509 510 if (IS_ERR_OR_NULL(rec)) 511 return; 512 for (i = 0; i < rec->cnt; i++) { 513 switch (rec->fields[i].type) { 514 case BPF_KPTR_UNREF: 515 case BPF_KPTR_REF: 516 case BPF_KPTR_PERCPU: 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 case BPF_KPTR_PERCPU: 564 btf_get(fields[i].kptr.btf); 565 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 566 ret = -ENXIO; 567 goto free; 568 } 569 break; 570 case BPF_LIST_HEAD: 571 case BPF_LIST_NODE: 572 case BPF_RB_ROOT: 573 case BPF_RB_NODE: 574 case BPF_SPIN_LOCK: 575 case BPF_TIMER: 576 case BPF_REFCOUNT: 577 /* Nothing to acquire */ 578 break; 579 default: 580 ret = -EFAULT; 581 WARN_ON_ONCE(1); 582 goto free; 583 } 584 new_rec->cnt++; 585 } 586 return new_rec; 587 free: 588 btf_record_free(new_rec); 589 return ERR_PTR(ret); 590 } 591 592 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 593 { 594 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 595 int size; 596 597 if (!a_has_fields && !b_has_fields) 598 return true; 599 if (a_has_fields != b_has_fields) 600 return false; 601 if (rec_a->cnt != rec_b->cnt) 602 return false; 603 size = offsetof(struct btf_record, fields[rec_a->cnt]); 604 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 605 * members are zeroed out. So memcmp is safe to do without worrying 606 * about padding/unused fields. 607 * 608 * While spin_lock, timer, and kptr have no relation to map BTF, 609 * list_head metadata is specific to map BTF, the btf and value_rec 610 * members in particular. btf is the map BTF, while value_rec points to 611 * btf_record in that map BTF. 612 * 613 * So while by default, we don't rely on the map BTF (which the records 614 * were parsed from) matching for both records, which is not backwards 615 * compatible, in case list_head is part of it, we implicitly rely on 616 * that by way of depending on memcmp succeeding for it. 617 */ 618 return !memcmp(rec_a, rec_b, size); 619 } 620 621 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 622 { 623 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 624 return; 625 bpf_timer_cancel_and_free(obj + rec->timer_off); 626 } 627 628 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 629 { 630 const struct btf_field *fields; 631 int i; 632 633 if (IS_ERR_OR_NULL(rec)) 634 return; 635 fields = rec->fields; 636 for (i = 0; i < rec->cnt; i++) { 637 struct btf_struct_meta *pointee_struct_meta; 638 const struct btf_field *field = &fields[i]; 639 void *field_ptr = obj + field->offset; 640 void *xchgd_field; 641 642 switch (fields[i].type) { 643 case BPF_SPIN_LOCK: 644 break; 645 case BPF_TIMER: 646 bpf_timer_cancel_and_free(field_ptr); 647 break; 648 case BPF_KPTR_UNREF: 649 WRITE_ONCE(*(u64 *)field_ptr, 0); 650 break; 651 case BPF_KPTR_REF: 652 case BPF_KPTR_PERCPU: 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 : NULL, 663 fields[i].type == BPF_KPTR_PERCPU); 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_KPTR_PERCPU: 1078 case BPF_REFCOUNT: 1079 if (map->map_type != BPF_MAP_TYPE_HASH && 1080 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1081 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1082 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1083 map->map_type != BPF_MAP_TYPE_ARRAY && 1084 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1085 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1086 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1087 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1088 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1089 ret = -EOPNOTSUPP; 1090 goto free_map_tab; 1091 } 1092 break; 1093 case BPF_LIST_HEAD: 1094 case BPF_RB_ROOT: 1095 if (map->map_type != BPF_MAP_TYPE_HASH && 1096 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1097 map->map_type != BPF_MAP_TYPE_ARRAY) { 1098 ret = -EOPNOTSUPP; 1099 goto free_map_tab; 1100 } 1101 break; 1102 default: 1103 /* Fail if map_type checks are missing for a field type */ 1104 ret = -EOPNOTSUPP; 1105 goto free_map_tab; 1106 } 1107 } 1108 } 1109 1110 ret = btf_check_and_fixup_fields(btf, map->record); 1111 if (ret < 0) 1112 goto free_map_tab; 1113 1114 if (map->ops->map_check_btf) { 1115 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1116 if (ret < 0) 1117 goto free_map_tab; 1118 } 1119 1120 return ret; 1121 free_map_tab: 1122 bpf_map_free_record(map); 1123 return ret; 1124 } 1125 1126 #define BPF_MAP_CREATE_LAST_FIELD map_extra 1127 /* called via syscall */ 1128 static int map_create(union bpf_attr *attr) 1129 { 1130 const struct bpf_map_ops *ops; 1131 int numa_node = bpf_map_attr_numa_node(attr); 1132 u32 map_type = attr->map_type; 1133 struct bpf_map *map; 1134 int f_flags; 1135 int err; 1136 1137 err = CHECK_ATTR(BPF_MAP_CREATE); 1138 if (err) 1139 return -EINVAL; 1140 1141 if (attr->btf_vmlinux_value_type_id) { 1142 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || 1143 attr->btf_key_type_id || attr->btf_value_type_id) 1144 return -EINVAL; 1145 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1146 return -EINVAL; 1147 } 1148 1149 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1150 attr->map_extra != 0) 1151 return -EINVAL; 1152 1153 f_flags = bpf_get_file_flag(attr->map_flags); 1154 if (f_flags < 0) 1155 return f_flags; 1156 1157 if (numa_node != NUMA_NO_NODE && 1158 ((unsigned int)numa_node >= nr_node_ids || 1159 !node_online(numa_node))) 1160 return -EINVAL; 1161 1162 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1163 map_type = attr->map_type; 1164 if (map_type >= ARRAY_SIZE(bpf_map_types)) 1165 return -EINVAL; 1166 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1167 ops = bpf_map_types[map_type]; 1168 if (!ops) 1169 return -EINVAL; 1170 1171 if (ops->map_alloc_check) { 1172 err = ops->map_alloc_check(attr); 1173 if (err) 1174 return err; 1175 } 1176 if (attr->map_ifindex) 1177 ops = &bpf_map_offload_ops; 1178 if (!ops->map_mem_usage) 1179 return -EINVAL; 1180 1181 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1182 * creation for unprivileged users; other actions depend 1183 * on fd availability and access to bpffs, so are dependent on 1184 * object creation success. Even with unprivileged BPF disabled, 1185 * capability checks are still carried out. 1186 */ 1187 if (sysctl_unprivileged_bpf_disabled && !bpf_capable()) 1188 return -EPERM; 1189 1190 /* check privileged map type permissions */ 1191 switch (map_type) { 1192 case BPF_MAP_TYPE_ARRAY: 1193 case BPF_MAP_TYPE_PERCPU_ARRAY: 1194 case BPF_MAP_TYPE_PROG_ARRAY: 1195 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1196 case BPF_MAP_TYPE_CGROUP_ARRAY: 1197 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1198 case BPF_MAP_TYPE_HASH: 1199 case BPF_MAP_TYPE_PERCPU_HASH: 1200 case BPF_MAP_TYPE_HASH_OF_MAPS: 1201 case BPF_MAP_TYPE_RINGBUF: 1202 case BPF_MAP_TYPE_USER_RINGBUF: 1203 case BPF_MAP_TYPE_CGROUP_STORAGE: 1204 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1205 /* unprivileged */ 1206 break; 1207 case BPF_MAP_TYPE_SK_STORAGE: 1208 case BPF_MAP_TYPE_INODE_STORAGE: 1209 case BPF_MAP_TYPE_TASK_STORAGE: 1210 case BPF_MAP_TYPE_CGRP_STORAGE: 1211 case BPF_MAP_TYPE_BLOOM_FILTER: 1212 case BPF_MAP_TYPE_LPM_TRIE: 1213 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1214 case BPF_MAP_TYPE_STACK_TRACE: 1215 case BPF_MAP_TYPE_QUEUE: 1216 case BPF_MAP_TYPE_STACK: 1217 case BPF_MAP_TYPE_LRU_HASH: 1218 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1219 case BPF_MAP_TYPE_STRUCT_OPS: 1220 case BPF_MAP_TYPE_CPUMAP: 1221 if (!bpf_capable()) 1222 return -EPERM; 1223 break; 1224 case BPF_MAP_TYPE_SOCKMAP: 1225 case BPF_MAP_TYPE_SOCKHASH: 1226 case BPF_MAP_TYPE_DEVMAP: 1227 case BPF_MAP_TYPE_DEVMAP_HASH: 1228 case BPF_MAP_TYPE_XSKMAP: 1229 if (!capable(CAP_NET_ADMIN)) 1230 return -EPERM; 1231 break; 1232 default: 1233 WARN(1, "unsupported map type %d", map_type); 1234 return -EPERM; 1235 } 1236 1237 map = ops->map_alloc(attr); 1238 if (IS_ERR(map)) 1239 return PTR_ERR(map); 1240 map->ops = ops; 1241 map->map_type = map_type; 1242 1243 err = bpf_obj_name_cpy(map->name, attr->map_name, 1244 sizeof(attr->map_name)); 1245 if (err < 0) 1246 goto free_map; 1247 1248 atomic64_set(&map->refcnt, 1); 1249 atomic64_set(&map->usercnt, 1); 1250 mutex_init(&map->freeze_mutex); 1251 spin_lock_init(&map->owner.lock); 1252 1253 if (attr->btf_key_type_id || attr->btf_value_type_id || 1254 /* Even the map's value is a kernel's struct, 1255 * the bpf_prog.o must have BTF to begin with 1256 * to figure out the corresponding kernel's 1257 * counter part. Thus, attr->btf_fd has 1258 * to be valid also. 1259 */ 1260 attr->btf_vmlinux_value_type_id) { 1261 struct btf *btf; 1262 1263 btf = btf_get_by_fd(attr->btf_fd); 1264 if (IS_ERR(btf)) { 1265 err = PTR_ERR(btf); 1266 goto free_map; 1267 } 1268 if (btf_is_kernel(btf)) { 1269 btf_put(btf); 1270 err = -EACCES; 1271 goto free_map; 1272 } 1273 map->btf = btf; 1274 1275 if (attr->btf_value_type_id) { 1276 err = map_check_btf(map, btf, attr->btf_key_type_id, 1277 attr->btf_value_type_id); 1278 if (err) 1279 goto free_map; 1280 } 1281 1282 map->btf_key_type_id = attr->btf_key_type_id; 1283 map->btf_value_type_id = attr->btf_value_type_id; 1284 map->btf_vmlinux_value_type_id = 1285 attr->btf_vmlinux_value_type_id; 1286 } 1287 1288 err = security_bpf_map_alloc(map); 1289 if (err) 1290 goto free_map; 1291 1292 err = bpf_map_alloc_id(map); 1293 if (err) 1294 goto free_map_sec; 1295 1296 bpf_map_save_memcg(map); 1297 1298 err = bpf_map_new_fd(map, f_flags); 1299 if (err < 0) { 1300 /* failed to allocate fd. 1301 * bpf_map_put_with_uref() is needed because the above 1302 * bpf_map_alloc_id() has published the map 1303 * to the userspace and the userspace may 1304 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1305 */ 1306 bpf_map_put_with_uref(map); 1307 return err; 1308 } 1309 1310 return err; 1311 1312 free_map_sec: 1313 security_bpf_map_free(map); 1314 free_map: 1315 btf_put(map->btf); 1316 map->ops->map_free(map); 1317 return err; 1318 } 1319 1320 /* if error is returned, fd is released. 1321 * On success caller should complete fd access with matching fdput() 1322 */ 1323 struct bpf_map *__bpf_map_get(struct fd f) 1324 { 1325 if (!f.file) 1326 return ERR_PTR(-EBADF); 1327 if (f.file->f_op != &bpf_map_fops) { 1328 fdput(f); 1329 return ERR_PTR(-EINVAL); 1330 } 1331 1332 return f.file->private_data; 1333 } 1334 1335 void bpf_map_inc(struct bpf_map *map) 1336 { 1337 atomic64_inc(&map->refcnt); 1338 } 1339 EXPORT_SYMBOL_GPL(bpf_map_inc); 1340 1341 void bpf_map_inc_with_uref(struct bpf_map *map) 1342 { 1343 atomic64_inc(&map->refcnt); 1344 atomic64_inc(&map->usercnt); 1345 } 1346 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1347 1348 struct bpf_map *bpf_map_get(u32 ufd) 1349 { 1350 struct fd f = fdget(ufd); 1351 struct bpf_map *map; 1352 1353 map = __bpf_map_get(f); 1354 if (IS_ERR(map)) 1355 return map; 1356 1357 bpf_map_inc(map); 1358 fdput(f); 1359 1360 return map; 1361 } 1362 EXPORT_SYMBOL(bpf_map_get); 1363 1364 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1365 { 1366 struct fd f = fdget(ufd); 1367 struct bpf_map *map; 1368 1369 map = __bpf_map_get(f); 1370 if (IS_ERR(map)) 1371 return map; 1372 1373 bpf_map_inc_with_uref(map); 1374 fdput(f); 1375 1376 return map; 1377 } 1378 1379 /* map_idr_lock should have been held or the map should have been 1380 * protected by rcu read lock. 1381 */ 1382 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1383 { 1384 int refold; 1385 1386 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1387 if (!refold) 1388 return ERR_PTR(-ENOENT); 1389 if (uref) 1390 atomic64_inc(&map->usercnt); 1391 1392 return map; 1393 } 1394 1395 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1396 { 1397 spin_lock_bh(&map_idr_lock); 1398 map = __bpf_map_inc_not_zero(map, false); 1399 spin_unlock_bh(&map_idr_lock); 1400 1401 return map; 1402 } 1403 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1404 1405 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) 1406 { 1407 return -ENOTSUPP; 1408 } 1409 1410 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1411 { 1412 if (key_size) 1413 return vmemdup_user(ukey, key_size); 1414 1415 if (ukey) 1416 return ERR_PTR(-EINVAL); 1417 1418 return NULL; 1419 } 1420 1421 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1422 { 1423 if (key_size) 1424 return kvmemdup_bpfptr(ukey, key_size); 1425 1426 if (!bpfptr_is_null(ukey)) 1427 return ERR_PTR(-EINVAL); 1428 1429 return NULL; 1430 } 1431 1432 /* last field in 'union bpf_attr' used by this command */ 1433 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1434 1435 static int map_lookup_elem(union bpf_attr *attr) 1436 { 1437 void __user *ukey = u64_to_user_ptr(attr->key); 1438 void __user *uvalue = u64_to_user_ptr(attr->value); 1439 int ufd = attr->map_fd; 1440 struct bpf_map *map; 1441 void *key, *value; 1442 u32 value_size; 1443 struct fd f; 1444 int err; 1445 1446 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1447 return -EINVAL; 1448 1449 if (attr->flags & ~BPF_F_LOCK) 1450 return -EINVAL; 1451 1452 f = fdget(ufd); 1453 map = __bpf_map_get(f); 1454 if (IS_ERR(map)) 1455 return PTR_ERR(map); 1456 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1457 err = -EPERM; 1458 goto err_put; 1459 } 1460 1461 if ((attr->flags & BPF_F_LOCK) && 1462 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1463 err = -EINVAL; 1464 goto err_put; 1465 } 1466 1467 key = __bpf_copy_key(ukey, map->key_size); 1468 if (IS_ERR(key)) { 1469 err = PTR_ERR(key); 1470 goto err_put; 1471 } 1472 1473 value_size = bpf_map_value_size(map); 1474 1475 err = -ENOMEM; 1476 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1477 if (!value) 1478 goto free_key; 1479 1480 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1481 if (copy_from_user(value, uvalue, value_size)) 1482 err = -EFAULT; 1483 else 1484 err = bpf_map_copy_value(map, key, value, attr->flags); 1485 goto free_value; 1486 } 1487 1488 err = bpf_map_copy_value(map, key, value, attr->flags); 1489 if (err) 1490 goto free_value; 1491 1492 err = -EFAULT; 1493 if (copy_to_user(uvalue, value, value_size) != 0) 1494 goto free_value; 1495 1496 err = 0; 1497 1498 free_value: 1499 kvfree(value); 1500 free_key: 1501 kvfree(key); 1502 err_put: 1503 fdput(f); 1504 return err; 1505 } 1506 1507 1508 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1509 1510 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1511 { 1512 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1513 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1514 int ufd = attr->map_fd; 1515 struct bpf_map *map; 1516 void *key, *value; 1517 u32 value_size; 1518 struct fd f; 1519 int err; 1520 1521 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1522 return -EINVAL; 1523 1524 f = fdget(ufd); 1525 map = __bpf_map_get(f); 1526 if (IS_ERR(map)) 1527 return PTR_ERR(map); 1528 bpf_map_write_active_inc(map); 1529 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1530 err = -EPERM; 1531 goto err_put; 1532 } 1533 1534 if ((attr->flags & BPF_F_LOCK) && 1535 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1536 err = -EINVAL; 1537 goto err_put; 1538 } 1539 1540 key = ___bpf_copy_key(ukey, map->key_size); 1541 if (IS_ERR(key)) { 1542 err = PTR_ERR(key); 1543 goto err_put; 1544 } 1545 1546 value_size = bpf_map_value_size(map); 1547 value = kvmemdup_bpfptr(uvalue, value_size); 1548 if (IS_ERR(value)) { 1549 err = PTR_ERR(value); 1550 goto free_key; 1551 } 1552 1553 err = bpf_map_update_value(map, f.file, key, value, attr->flags); 1554 if (!err) 1555 maybe_wait_bpf_programs(map); 1556 1557 kvfree(value); 1558 free_key: 1559 kvfree(key); 1560 err_put: 1561 bpf_map_write_active_dec(map); 1562 fdput(f); 1563 return err; 1564 } 1565 1566 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1567 1568 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1569 { 1570 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1571 int ufd = attr->map_fd; 1572 struct bpf_map *map; 1573 struct fd f; 1574 void *key; 1575 int err; 1576 1577 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1578 return -EINVAL; 1579 1580 f = fdget(ufd); 1581 map = __bpf_map_get(f); 1582 if (IS_ERR(map)) 1583 return PTR_ERR(map); 1584 bpf_map_write_active_inc(map); 1585 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1586 err = -EPERM; 1587 goto err_put; 1588 } 1589 1590 key = ___bpf_copy_key(ukey, map->key_size); 1591 if (IS_ERR(key)) { 1592 err = PTR_ERR(key); 1593 goto err_put; 1594 } 1595 1596 if (bpf_map_is_offloaded(map)) { 1597 err = bpf_map_offload_delete_elem(map, key); 1598 goto out; 1599 } else if (IS_FD_PROG_ARRAY(map) || 1600 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1601 /* These maps require sleepable context */ 1602 err = map->ops->map_delete_elem(map, key); 1603 goto out; 1604 } 1605 1606 bpf_disable_instrumentation(); 1607 rcu_read_lock(); 1608 err = map->ops->map_delete_elem(map, key); 1609 rcu_read_unlock(); 1610 bpf_enable_instrumentation(); 1611 if (!err) 1612 maybe_wait_bpf_programs(map); 1613 out: 1614 kvfree(key); 1615 err_put: 1616 bpf_map_write_active_dec(map); 1617 fdput(f); 1618 return err; 1619 } 1620 1621 /* last field in 'union bpf_attr' used by this command */ 1622 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1623 1624 static int map_get_next_key(union bpf_attr *attr) 1625 { 1626 void __user *ukey = u64_to_user_ptr(attr->key); 1627 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1628 int ufd = attr->map_fd; 1629 struct bpf_map *map; 1630 void *key, *next_key; 1631 struct fd f; 1632 int err; 1633 1634 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1635 return -EINVAL; 1636 1637 f = fdget(ufd); 1638 map = __bpf_map_get(f); 1639 if (IS_ERR(map)) 1640 return PTR_ERR(map); 1641 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 1642 err = -EPERM; 1643 goto err_put; 1644 } 1645 1646 if (ukey) { 1647 key = __bpf_copy_key(ukey, map->key_size); 1648 if (IS_ERR(key)) { 1649 err = PTR_ERR(key); 1650 goto err_put; 1651 } 1652 } else { 1653 key = NULL; 1654 } 1655 1656 err = -ENOMEM; 1657 next_key = kvmalloc(map->key_size, GFP_USER); 1658 if (!next_key) 1659 goto free_key; 1660 1661 if (bpf_map_is_offloaded(map)) { 1662 err = bpf_map_offload_get_next_key(map, key, next_key); 1663 goto out; 1664 } 1665 1666 rcu_read_lock(); 1667 err = map->ops->map_get_next_key(map, key, next_key); 1668 rcu_read_unlock(); 1669 out: 1670 if (err) 1671 goto free_next_key; 1672 1673 err = -EFAULT; 1674 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1675 goto free_next_key; 1676 1677 err = 0; 1678 1679 free_next_key: 1680 kvfree(next_key); 1681 free_key: 1682 kvfree(key); 1683 err_put: 1684 fdput(f); 1685 return err; 1686 } 1687 1688 int generic_map_delete_batch(struct bpf_map *map, 1689 const union bpf_attr *attr, 1690 union bpf_attr __user *uattr) 1691 { 1692 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1693 u32 cp, max_count; 1694 int err = 0; 1695 void *key; 1696 1697 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1698 return -EINVAL; 1699 1700 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1701 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1702 return -EINVAL; 1703 } 1704 1705 max_count = attr->batch.count; 1706 if (!max_count) 1707 return 0; 1708 1709 if (put_user(0, &uattr->batch.count)) 1710 return -EFAULT; 1711 1712 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1713 if (!key) 1714 return -ENOMEM; 1715 1716 for (cp = 0; cp < max_count; cp++) { 1717 err = -EFAULT; 1718 if (copy_from_user(key, keys + cp * map->key_size, 1719 map->key_size)) 1720 break; 1721 1722 if (bpf_map_is_offloaded(map)) { 1723 err = bpf_map_offload_delete_elem(map, key); 1724 break; 1725 } 1726 1727 bpf_disable_instrumentation(); 1728 rcu_read_lock(); 1729 err = map->ops->map_delete_elem(map, key); 1730 rcu_read_unlock(); 1731 bpf_enable_instrumentation(); 1732 if (err) 1733 break; 1734 cond_resched(); 1735 } 1736 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1737 err = -EFAULT; 1738 1739 kvfree(key); 1740 1741 return err; 1742 } 1743 1744 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 1745 const union bpf_attr *attr, 1746 union bpf_attr __user *uattr) 1747 { 1748 void __user *values = u64_to_user_ptr(attr->batch.values); 1749 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1750 u32 value_size, cp, max_count; 1751 void *key, *value; 1752 int err = 0; 1753 1754 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1755 return -EINVAL; 1756 1757 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1758 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1759 return -EINVAL; 1760 } 1761 1762 value_size = bpf_map_value_size(map); 1763 1764 max_count = attr->batch.count; 1765 if (!max_count) 1766 return 0; 1767 1768 if (put_user(0, &uattr->batch.count)) 1769 return -EFAULT; 1770 1771 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1772 if (!key) 1773 return -ENOMEM; 1774 1775 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1776 if (!value) { 1777 kvfree(key); 1778 return -ENOMEM; 1779 } 1780 1781 for (cp = 0; cp < max_count; cp++) { 1782 err = -EFAULT; 1783 if (copy_from_user(key, keys + cp * map->key_size, 1784 map->key_size) || 1785 copy_from_user(value, values + cp * value_size, value_size)) 1786 break; 1787 1788 err = bpf_map_update_value(map, map_file, key, value, 1789 attr->batch.elem_flags); 1790 1791 if (err) 1792 break; 1793 cond_resched(); 1794 } 1795 1796 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1797 err = -EFAULT; 1798 1799 kvfree(value); 1800 kvfree(key); 1801 1802 return err; 1803 } 1804 1805 #define MAP_LOOKUP_RETRIES 3 1806 1807 int generic_map_lookup_batch(struct bpf_map *map, 1808 const union bpf_attr *attr, 1809 union bpf_attr __user *uattr) 1810 { 1811 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 1812 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 1813 void __user *values = u64_to_user_ptr(attr->batch.values); 1814 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1815 void *buf, *buf_prevkey, *prev_key, *key, *value; 1816 int err, retry = MAP_LOOKUP_RETRIES; 1817 u32 value_size, cp, max_count; 1818 1819 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1820 return -EINVAL; 1821 1822 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1823 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 1824 return -EINVAL; 1825 1826 value_size = bpf_map_value_size(map); 1827 1828 max_count = attr->batch.count; 1829 if (!max_count) 1830 return 0; 1831 1832 if (put_user(0, &uattr->batch.count)) 1833 return -EFAULT; 1834 1835 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1836 if (!buf_prevkey) 1837 return -ENOMEM; 1838 1839 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 1840 if (!buf) { 1841 kvfree(buf_prevkey); 1842 return -ENOMEM; 1843 } 1844 1845 err = -EFAULT; 1846 prev_key = NULL; 1847 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 1848 goto free_buf; 1849 key = buf; 1850 value = key + map->key_size; 1851 if (ubatch) 1852 prev_key = buf_prevkey; 1853 1854 for (cp = 0; cp < max_count;) { 1855 rcu_read_lock(); 1856 err = map->ops->map_get_next_key(map, prev_key, key); 1857 rcu_read_unlock(); 1858 if (err) 1859 break; 1860 err = bpf_map_copy_value(map, key, value, 1861 attr->batch.elem_flags); 1862 1863 if (err == -ENOENT) { 1864 if (retry) { 1865 retry--; 1866 continue; 1867 } 1868 err = -EINTR; 1869 break; 1870 } 1871 1872 if (err) 1873 goto free_buf; 1874 1875 if (copy_to_user(keys + cp * map->key_size, key, 1876 map->key_size)) { 1877 err = -EFAULT; 1878 goto free_buf; 1879 } 1880 if (copy_to_user(values + cp * value_size, value, value_size)) { 1881 err = -EFAULT; 1882 goto free_buf; 1883 } 1884 1885 if (!prev_key) 1886 prev_key = buf_prevkey; 1887 1888 swap(prev_key, key); 1889 retry = MAP_LOOKUP_RETRIES; 1890 cp++; 1891 cond_resched(); 1892 } 1893 1894 if (err == -EFAULT) 1895 goto free_buf; 1896 1897 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 1898 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 1899 err = -EFAULT; 1900 1901 free_buf: 1902 kvfree(buf_prevkey); 1903 kvfree(buf); 1904 return err; 1905 } 1906 1907 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 1908 1909 static int map_lookup_and_delete_elem(union bpf_attr *attr) 1910 { 1911 void __user *ukey = u64_to_user_ptr(attr->key); 1912 void __user *uvalue = u64_to_user_ptr(attr->value); 1913 int ufd = attr->map_fd; 1914 struct bpf_map *map; 1915 void *key, *value; 1916 u32 value_size; 1917 struct fd f; 1918 int err; 1919 1920 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 1921 return -EINVAL; 1922 1923 if (attr->flags & ~BPF_F_LOCK) 1924 return -EINVAL; 1925 1926 f = fdget(ufd); 1927 map = __bpf_map_get(f); 1928 if (IS_ERR(map)) 1929 return PTR_ERR(map); 1930 bpf_map_write_active_inc(map); 1931 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 1932 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1933 err = -EPERM; 1934 goto err_put; 1935 } 1936 1937 if (attr->flags && 1938 (map->map_type == BPF_MAP_TYPE_QUEUE || 1939 map->map_type == BPF_MAP_TYPE_STACK)) { 1940 err = -EINVAL; 1941 goto err_put; 1942 } 1943 1944 if ((attr->flags & BPF_F_LOCK) && 1945 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1946 err = -EINVAL; 1947 goto err_put; 1948 } 1949 1950 key = __bpf_copy_key(ukey, map->key_size); 1951 if (IS_ERR(key)) { 1952 err = PTR_ERR(key); 1953 goto err_put; 1954 } 1955 1956 value_size = bpf_map_value_size(map); 1957 1958 err = -ENOMEM; 1959 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1960 if (!value) 1961 goto free_key; 1962 1963 err = -ENOTSUPP; 1964 if (map->map_type == BPF_MAP_TYPE_QUEUE || 1965 map->map_type == BPF_MAP_TYPE_STACK) { 1966 err = map->ops->map_pop_elem(map, value); 1967 } else if (map->map_type == BPF_MAP_TYPE_HASH || 1968 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 1969 map->map_type == BPF_MAP_TYPE_LRU_HASH || 1970 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 1971 if (!bpf_map_is_offloaded(map)) { 1972 bpf_disable_instrumentation(); 1973 rcu_read_lock(); 1974 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 1975 rcu_read_unlock(); 1976 bpf_enable_instrumentation(); 1977 } 1978 } 1979 1980 if (err) 1981 goto free_value; 1982 1983 if (copy_to_user(uvalue, value, value_size) != 0) { 1984 err = -EFAULT; 1985 goto free_value; 1986 } 1987 1988 err = 0; 1989 1990 free_value: 1991 kvfree(value); 1992 free_key: 1993 kvfree(key); 1994 err_put: 1995 bpf_map_write_active_dec(map); 1996 fdput(f); 1997 return err; 1998 } 1999 2000 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2001 2002 static int map_freeze(const union bpf_attr *attr) 2003 { 2004 int err = 0, ufd = attr->map_fd; 2005 struct bpf_map *map; 2006 struct fd f; 2007 2008 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2009 return -EINVAL; 2010 2011 f = fdget(ufd); 2012 map = __bpf_map_get(f); 2013 if (IS_ERR(map)) 2014 return PTR_ERR(map); 2015 2016 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) { 2017 fdput(f); 2018 return -ENOTSUPP; 2019 } 2020 2021 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2022 fdput(f); 2023 return -EPERM; 2024 } 2025 2026 mutex_lock(&map->freeze_mutex); 2027 if (bpf_map_write_active(map)) { 2028 err = -EBUSY; 2029 goto err_put; 2030 } 2031 if (READ_ONCE(map->frozen)) { 2032 err = -EBUSY; 2033 goto err_put; 2034 } 2035 2036 WRITE_ONCE(map->frozen, true); 2037 err_put: 2038 mutex_unlock(&map->freeze_mutex); 2039 fdput(f); 2040 return err; 2041 } 2042 2043 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2044 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2045 [_id] = & _name ## _prog_ops, 2046 #define BPF_MAP_TYPE(_id, _ops) 2047 #define BPF_LINK_TYPE(_id, _name) 2048 #include <linux/bpf_types.h> 2049 #undef BPF_PROG_TYPE 2050 #undef BPF_MAP_TYPE 2051 #undef BPF_LINK_TYPE 2052 }; 2053 2054 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2055 { 2056 const struct bpf_prog_ops *ops; 2057 2058 if (type >= ARRAY_SIZE(bpf_prog_types)) 2059 return -EINVAL; 2060 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2061 ops = bpf_prog_types[type]; 2062 if (!ops) 2063 return -EINVAL; 2064 2065 if (!bpf_prog_is_offloaded(prog->aux)) 2066 prog->aux->ops = ops; 2067 else 2068 prog->aux->ops = &bpf_offload_prog_ops; 2069 prog->type = type; 2070 return 0; 2071 } 2072 2073 enum bpf_audit { 2074 BPF_AUDIT_LOAD, 2075 BPF_AUDIT_UNLOAD, 2076 BPF_AUDIT_MAX, 2077 }; 2078 2079 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2080 [BPF_AUDIT_LOAD] = "LOAD", 2081 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2082 }; 2083 2084 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2085 { 2086 struct audit_context *ctx = NULL; 2087 struct audit_buffer *ab; 2088 2089 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2090 return; 2091 if (audit_enabled == AUDIT_OFF) 2092 return; 2093 if (!in_irq() && !irqs_disabled()) 2094 ctx = audit_context(); 2095 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2096 if (unlikely(!ab)) 2097 return; 2098 audit_log_format(ab, "prog-id=%u op=%s", 2099 prog->aux->id, bpf_audit_str[op]); 2100 audit_log_end(ab); 2101 } 2102 2103 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2104 { 2105 int id; 2106 2107 idr_preload(GFP_KERNEL); 2108 spin_lock_bh(&prog_idr_lock); 2109 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2110 if (id > 0) 2111 prog->aux->id = id; 2112 spin_unlock_bh(&prog_idr_lock); 2113 idr_preload_end(); 2114 2115 /* id is in [1, INT_MAX) */ 2116 if (WARN_ON_ONCE(!id)) 2117 return -ENOSPC; 2118 2119 return id > 0 ? 0 : id; 2120 } 2121 2122 void bpf_prog_free_id(struct bpf_prog *prog) 2123 { 2124 unsigned long flags; 2125 2126 /* cBPF to eBPF migrations are currently not in the idr store. 2127 * Offloaded programs are removed from the store when their device 2128 * disappears - even if someone grabs an fd to them they are unusable, 2129 * simply waiting for refcnt to drop to be freed. 2130 */ 2131 if (!prog->aux->id) 2132 return; 2133 2134 spin_lock_irqsave(&prog_idr_lock, flags); 2135 idr_remove(&prog_idr, prog->aux->id); 2136 prog->aux->id = 0; 2137 spin_unlock_irqrestore(&prog_idr_lock, flags); 2138 } 2139 2140 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2141 { 2142 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2143 2144 kvfree(aux->func_info); 2145 kfree(aux->func_info_aux); 2146 free_uid(aux->user); 2147 security_bpf_prog_free(aux); 2148 bpf_prog_free(aux->prog); 2149 } 2150 2151 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2152 { 2153 bpf_prog_kallsyms_del_all(prog); 2154 btf_put(prog->aux->btf); 2155 module_put(prog->aux->mod); 2156 kvfree(prog->aux->jited_linfo); 2157 kvfree(prog->aux->linfo); 2158 kfree(prog->aux->kfunc_tab); 2159 if (prog->aux->attach_btf) 2160 btf_put(prog->aux->attach_btf); 2161 2162 if (deferred) { 2163 if (prog->aux->sleepable) 2164 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2165 else 2166 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2167 } else { 2168 __bpf_prog_put_rcu(&prog->aux->rcu); 2169 } 2170 } 2171 2172 static void bpf_prog_put_deferred(struct work_struct *work) 2173 { 2174 struct bpf_prog_aux *aux; 2175 struct bpf_prog *prog; 2176 2177 aux = container_of(work, struct bpf_prog_aux, work); 2178 prog = aux->prog; 2179 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2180 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2181 bpf_prog_free_id(prog); 2182 __bpf_prog_put_noref(prog, true); 2183 } 2184 2185 static void __bpf_prog_put(struct bpf_prog *prog) 2186 { 2187 struct bpf_prog_aux *aux = prog->aux; 2188 2189 if (atomic64_dec_and_test(&aux->refcnt)) { 2190 if (in_irq() || irqs_disabled()) { 2191 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2192 schedule_work(&aux->work); 2193 } else { 2194 bpf_prog_put_deferred(&aux->work); 2195 } 2196 } 2197 } 2198 2199 void bpf_prog_put(struct bpf_prog *prog) 2200 { 2201 __bpf_prog_put(prog); 2202 } 2203 EXPORT_SYMBOL_GPL(bpf_prog_put); 2204 2205 static int bpf_prog_release(struct inode *inode, struct file *filp) 2206 { 2207 struct bpf_prog *prog = filp->private_data; 2208 2209 bpf_prog_put(prog); 2210 return 0; 2211 } 2212 2213 struct bpf_prog_kstats { 2214 u64 nsecs; 2215 u64 cnt; 2216 u64 misses; 2217 }; 2218 2219 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2220 { 2221 struct bpf_prog_stats *stats; 2222 unsigned int flags; 2223 2224 stats = this_cpu_ptr(prog->stats); 2225 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2226 u64_stats_inc(&stats->misses); 2227 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2228 } 2229 2230 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2231 struct bpf_prog_kstats *stats) 2232 { 2233 u64 nsecs = 0, cnt = 0, misses = 0; 2234 int cpu; 2235 2236 for_each_possible_cpu(cpu) { 2237 const struct bpf_prog_stats *st; 2238 unsigned int start; 2239 u64 tnsecs, tcnt, tmisses; 2240 2241 st = per_cpu_ptr(prog->stats, cpu); 2242 do { 2243 start = u64_stats_fetch_begin(&st->syncp); 2244 tnsecs = u64_stats_read(&st->nsecs); 2245 tcnt = u64_stats_read(&st->cnt); 2246 tmisses = u64_stats_read(&st->misses); 2247 } while (u64_stats_fetch_retry(&st->syncp, start)); 2248 nsecs += tnsecs; 2249 cnt += tcnt; 2250 misses += tmisses; 2251 } 2252 stats->nsecs = nsecs; 2253 stats->cnt = cnt; 2254 stats->misses = misses; 2255 } 2256 2257 #ifdef CONFIG_PROC_FS 2258 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2259 { 2260 const struct bpf_prog *prog = filp->private_data; 2261 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2262 struct bpf_prog_kstats stats; 2263 2264 bpf_prog_get_stats(prog, &stats); 2265 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2266 seq_printf(m, 2267 "prog_type:\t%u\n" 2268 "prog_jited:\t%u\n" 2269 "prog_tag:\t%s\n" 2270 "memlock:\t%llu\n" 2271 "prog_id:\t%u\n" 2272 "run_time_ns:\t%llu\n" 2273 "run_cnt:\t%llu\n" 2274 "recursion_misses:\t%llu\n" 2275 "verified_insns:\t%u\n", 2276 prog->type, 2277 prog->jited, 2278 prog_tag, 2279 prog->pages * 1ULL << PAGE_SHIFT, 2280 prog->aux->id, 2281 stats.nsecs, 2282 stats.cnt, 2283 stats.misses, 2284 prog->aux->verified_insns); 2285 } 2286 #endif 2287 2288 const struct file_operations bpf_prog_fops = { 2289 #ifdef CONFIG_PROC_FS 2290 .show_fdinfo = bpf_prog_show_fdinfo, 2291 #endif 2292 .release = bpf_prog_release, 2293 .read = bpf_dummy_read, 2294 .write = bpf_dummy_write, 2295 }; 2296 2297 int bpf_prog_new_fd(struct bpf_prog *prog) 2298 { 2299 int ret; 2300 2301 ret = security_bpf_prog(prog); 2302 if (ret < 0) 2303 return ret; 2304 2305 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2306 O_RDWR | O_CLOEXEC); 2307 } 2308 2309 static struct bpf_prog *____bpf_prog_get(struct fd f) 2310 { 2311 if (!f.file) 2312 return ERR_PTR(-EBADF); 2313 if (f.file->f_op != &bpf_prog_fops) { 2314 fdput(f); 2315 return ERR_PTR(-EINVAL); 2316 } 2317 2318 return f.file->private_data; 2319 } 2320 2321 void bpf_prog_add(struct bpf_prog *prog, int i) 2322 { 2323 atomic64_add(i, &prog->aux->refcnt); 2324 } 2325 EXPORT_SYMBOL_GPL(bpf_prog_add); 2326 2327 void bpf_prog_sub(struct bpf_prog *prog, int i) 2328 { 2329 /* Only to be used for undoing previous bpf_prog_add() in some 2330 * error path. We still know that another entity in our call 2331 * path holds a reference to the program, thus atomic_sub() can 2332 * be safely used in such cases! 2333 */ 2334 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2335 } 2336 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2337 2338 void bpf_prog_inc(struct bpf_prog *prog) 2339 { 2340 atomic64_inc(&prog->aux->refcnt); 2341 } 2342 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2343 2344 /* prog_idr_lock should have been held */ 2345 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2346 { 2347 int refold; 2348 2349 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2350 2351 if (!refold) 2352 return ERR_PTR(-ENOENT); 2353 2354 return prog; 2355 } 2356 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2357 2358 bool bpf_prog_get_ok(struct bpf_prog *prog, 2359 enum bpf_prog_type *attach_type, bool attach_drv) 2360 { 2361 /* not an attachment, just a refcount inc, always allow */ 2362 if (!attach_type) 2363 return true; 2364 2365 if (prog->type != *attach_type) 2366 return false; 2367 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2368 return false; 2369 2370 return true; 2371 } 2372 2373 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2374 bool attach_drv) 2375 { 2376 struct fd f = fdget(ufd); 2377 struct bpf_prog *prog; 2378 2379 prog = ____bpf_prog_get(f); 2380 if (IS_ERR(prog)) 2381 return prog; 2382 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) { 2383 prog = ERR_PTR(-EINVAL); 2384 goto out; 2385 } 2386 2387 bpf_prog_inc(prog); 2388 out: 2389 fdput(f); 2390 return prog; 2391 } 2392 2393 struct bpf_prog *bpf_prog_get(u32 ufd) 2394 { 2395 return __bpf_prog_get(ufd, NULL, false); 2396 } 2397 2398 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2399 bool attach_drv) 2400 { 2401 return __bpf_prog_get(ufd, &type, attach_drv); 2402 } 2403 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2404 2405 /* Initially all BPF programs could be loaded w/o specifying 2406 * expected_attach_type. Later for some of them specifying expected_attach_type 2407 * at load time became required so that program could be validated properly. 2408 * Programs of types that are allowed to be loaded both w/ and w/o (for 2409 * backward compatibility) expected_attach_type, should have the default attach 2410 * type assigned to expected_attach_type for the latter case, so that it can be 2411 * validated later at attach time. 2412 * 2413 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2414 * prog type requires it but has some attach types that have to be backward 2415 * compatible. 2416 */ 2417 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2418 { 2419 switch (attr->prog_type) { 2420 case BPF_PROG_TYPE_CGROUP_SOCK: 2421 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2422 * exist so checking for non-zero is the way to go here. 2423 */ 2424 if (!attr->expected_attach_type) 2425 attr->expected_attach_type = 2426 BPF_CGROUP_INET_SOCK_CREATE; 2427 break; 2428 case BPF_PROG_TYPE_SK_REUSEPORT: 2429 if (!attr->expected_attach_type) 2430 attr->expected_attach_type = 2431 BPF_SK_REUSEPORT_SELECT; 2432 break; 2433 } 2434 } 2435 2436 static int 2437 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2438 enum bpf_attach_type expected_attach_type, 2439 struct btf *attach_btf, u32 btf_id, 2440 struct bpf_prog *dst_prog) 2441 { 2442 if (btf_id) { 2443 if (btf_id > BTF_MAX_TYPE) 2444 return -EINVAL; 2445 2446 if (!attach_btf && !dst_prog) 2447 return -EINVAL; 2448 2449 switch (prog_type) { 2450 case BPF_PROG_TYPE_TRACING: 2451 case BPF_PROG_TYPE_LSM: 2452 case BPF_PROG_TYPE_STRUCT_OPS: 2453 case BPF_PROG_TYPE_EXT: 2454 break; 2455 default: 2456 return -EINVAL; 2457 } 2458 } 2459 2460 if (attach_btf && (!btf_id || dst_prog)) 2461 return -EINVAL; 2462 2463 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2464 prog_type != BPF_PROG_TYPE_EXT) 2465 return -EINVAL; 2466 2467 switch (prog_type) { 2468 case BPF_PROG_TYPE_CGROUP_SOCK: 2469 switch (expected_attach_type) { 2470 case BPF_CGROUP_INET_SOCK_CREATE: 2471 case BPF_CGROUP_INET_SOCK_RELEASE: 2472 case BPF_CGROUP_INET4_POST_BIND: 2473 case BPF_CGROUP_INET6_POST_BIND: 2474 return 0; 2475 default: 2476 return -EINVAL; 2477 } 2478 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2479 switch (expected_attach_type) { 2480 case BPF_CGROUP_INET4_BIND: 2481 case BPF_CGROUP_INET6_BIND: 2482 case BPF_CGROUP_INET4_CONNECT: 2483 case BPF_CGROUP_INET6_CONNECT: 2484 case BPF_CGROUP_UNIX_CONNECT: 2485 case BPF_CGROUP_INET4_GETPEERNAME: 2486 case BPF_CGROUP_INET6_GETPEERNAME: 2487 case BPF_CGROUP_UNIX_GETPEERNAME: 2488 case BPF_CGROUP_INET4_GETSOCKNAME: 2489 case BPF_CGROUP_INET6_GETSOCKNAME: 2490 case BPF_CGROUP_UNIX_GETSOCKNAME: 2491 case BPF_CGROUP_UDP4_SENDMSG: 2492 case BPF_CGROUP_UDP6_SENDMSG: 2493 case BPF_CGROUP_UNIX_SENDMSG: 2494 case BPF_CGROUP_UDP4_RECVMSG: 2495 case BPF_CGROUP_UDP6_RECVMSG: 2496 case BPF_CGROUP_UNIX_RECVMSG: 2497 return 0; 2498 default: 2499 return -EINVAL; 2500 } 2501 case BPF_PROG_TYPE_CGROUP_SKB: 2502 switch (expected_attach_type) { 2503 case BPF_CGROUP_INET_INGRESS: 2504 case BPF_CGROUP_INET_EGRESS: 2505 return 0; 2506 default: 2507 return -EINVAL; 2508 } 2509 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2510 switch (expected_attach_type) { 2511 case BPF_CGROUP_SETSOCKOPT: 2512 case BPF_CGROUP_GETSOCKOPT: 2513 return 0; 2514 default: 2515 return -EINVAL; 2516 } 2517 case BPF_PROG_TYPE_SK_LOOKUP: 2518 if (expected_attach_type == BPF_SK_LOOKUP) 2519 return 0; 2520 return -EINVAL; 2521 case BPF_PROG_TYPE_SK_REUSEPORT: 2522 switch (expected_attach_type) { 2523 case BPF_SK_REUSEPORT_SELECT: 2524 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2525 return 0; 2526 default: 2527 return -EINVAL; 2528 } 2529 case BPF_PROG_TYPE_NETFILTER: 2530 if (expected_attach_type == BPF_NETFILTER) 2531 return 0; 2532 return -EINVAL; 2533 case BPF_PROG_TYPE_SYSCALL: 2534 case BPF_PROG_TYPE_EXT: 2535 if (expected_attach_type) 2536 return -EINVAL; 2537 fallthrough; 2538 default: 2539 return 0; 2540 } 2541 } 2542 2543 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2544 { 2545 switch (prog_type) { 2546 case BPF_PROG_TYPE_SCHED_CLS: 2547 case BPF_PROG_TYPE_SCHED_ACT: 2548 case BPF_PROG_TYPE_XDP: 2549 case BPF_PROG_TYPE_LWT_IN: 2550 case BPF_PROG_TYPE_LWT_OUT: 2551 case BPF_PROG_TYPE_LWT_XMIT: 2552 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2553 case BPF_PROG_TYPE_SK_SKB: 2554 case BPF_PROG_TYPE_SK_MSG: 2555 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2556 case BPF_PROG_TYPE_CGROUP_DEVICE: 2557 case BPF_PROG_TYPE_CGROUP_SOCK: 2558 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2559 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2560 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2561 case BPF_PROG_TYPE_SOCK_OPS: 2562 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2563 case BPF_PROG_TYPE_NETFILTER: 2564 return true; 2565 case BPF_PROG_TYPE_CGROUP_SKB: 2566 /* always unpriv */ 2567 case BPF_PROG_TYPE_SK_REUSEPORT: 2568 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2569 default: 2570 return false; 2571 } 2572 } 2573 2574 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2575 { 2576 switch (prog_type) { 2577 case BPF_PROG_TYPE_KPROBE: 2578 case BPF_PROG_TYPE_TRACEPOINT: 2579 case BPF_PROG_TYPE_PERF_EVENT: 2580 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2581 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2582 case BPF_PROG_TYPE_TRACING: 2583 case BPF_PROG_TYPE_LSM: 2584 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2585 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2586 return true; 2587 default: 2588 return false; 2589 } 2590 } 2591 2592 /* last field in 'union bpf_attr' used by this command */ 2593 #define BPF_PROG_LOAD_LAST_FIELD log_true_size 2594 2595 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) 2596 { 2597 enum bpf_prog_type type = attr->prog_type; 2598 struct bpf_prog *prog, *dst_prog = NULL; 2599 struct btf *attach_btf = NULL; 2600 int err; 2601 char license[128]; 2602 2603 if (CHECK_ATTR(BPF_PROG_LOAD)) 2604 return -EINVAL; 2605 2606 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2607 BPF_F_ANY_ALIGNMENT | 2608 BPF_F_TEST_STATE_FREQ | 2609 BPF_F_SLEEPABLE | 2610 BPF_F_TEST_RND_HI32 | 2611 BPF_F_XDP_HAS_FRAGS | 2612 BPF_F_XDP_DEV_BOUND_ONLY | 2613 BPF_F_TEST_REG_INVARIANTS)) 2614 return -EINVAL; 2615 2616 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2617 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2618 !bpf_capable()) 2619 return -EPERM; 2620 2621 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2622 * creation for unprivileged users; other actions depend 2623 * on fd availability and access to bpffs, so are dependent on 2624 * object creation success. Even with unprivileged BPF disabled, 2625 * capability checks are still carried out for these 2626 * and other operations. 2627 */ 2628 if (sysctl_unprivileged_bpf_disabled && !bpf_capable()) 2629 return -EPERM; 2630 2631 if (attr->insn_cnt == 0 || 2632 attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) 2633 return -E2BIG; 2634 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2635 type != BPF_PROG_TYPE_CGROUP_SKB && 2636 !bpf_capable()) 2637 return -EPERM; 2638 2639 if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN)) 2640 return -EPERM; 2641 if (is_perfmon_prog_type(type) && !perfmon_capable()) 2642 return -EPERM; 2643 2644 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 2645 * or btf, we need to check which one it is 2646 */ 2647 if (attr->attach_prog_fd) { 2648 dst_prog = bpf_prog_get(attr->attach_prog_fd); 2649 if (IS_ERR(dst_prog)) { 2650 dst_prog = NULL; 2651 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 2652 if (IS_ERR(attach_btf)) 2653 return -EINVAL; 2654 if (!btf_is_kernel(attach_btf)) { 2655 /* attaching through specifying bpf_prog's BTF 2656 * objects directly might be supported eventually 2657 */ 2658 btf_put(attach_btf); 2659 return -ENOTSUPP; 2660 } 2661 } 2662 } else if (attr->attach_btf_id) { 2663 /* fall back to vmlinux BTF, if BTF type ID is specified */ 2664 attach_btf = bpf_get_btf_vmlinux(); 2665 if (IS_ERR(attach_btf)) 2666 return PTR_ERR(attach_btf); 2667 if (!attach_btf) 2668 return -EINVAL; 2669 btf_get(attach_btf); 2670 } 2671 2672 bpf_prog_load_fixup_attach_type(attr); 2673 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 2674 attach_btf, attr->attach_btf_id, 2675 dst_prog)) { 2676 if (dst_prog) 2677 bpf_prog_put(dst_prog); 2678 if (attach_btf) 2679 btf_put(attach_btf); 2680 return -EINVAL; 2681 } 2682 2683 /* plain bpf_prog allocation */ 2684 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 2685 if (!prog) { 2686 if (dst_prog) 2687 bpf_prog_put(dst_prog); 2688 if (attach_btf) 2689 btf_put(attach_btf); 2690 return -ENOMEM; 2691 } 2692 2693 prog->expected_attach_type = attr->expected_attach_type; 2694 prog->aux->attach_btf = attach_btf; 2695 prog->aux->attach_btf_id = attr->attach_btf_id; 2696 prog->aux->dst_prog = dst_prog; 2697 prog->aux->dev_bound = !!attr->prog_ifindex; 2698 prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE; 2699 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 2700 2701 err = security_bpf_prog_alloc(prog->aux); 2702 if (err) 2703 goto free_prog; 2704 2705 prog->aux->user = get_current_user(); 2706 prog->len = attr->insn_cnt; 2707 2708 err = -EFAULT; 2709 if (copy_from_bpfptr(prog->insns, 2710 make_bpfptr(attr->insns, uattr.is_kernel), 2711 bpf_prog_insn_size(prog)) != 0) 2712 goto free_prog_sec; 2713 /* copy eBPF program license from user space */ 2714 if (strncpy_from_bpfptr(license, 2715 make_bpfptr(attr->license, uattr.is_kernel), 2716 sizeof(license) - 1) < 0) 2717 goto free_prog_sec; 2718 license[sizeof(license) - 1] = 0; 2719 2720 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 2721 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 2722 2723 prog->orig_prog = NULL; 2724 prog->jited = 0; 2725 2726 atomic64_set(&prog->aux->refcnt, 1); 2727 2728 if (bpf_prog_is_dev_bound(prog->aux)) { 2729 err = bpf_prog_dev_bound_init(prog, attr); 2730 if (err) 2731 goto free_prog_sec; 2732 } 2733 2734 if (type == BPF_PROG_TYPE_EXT && dst_prog && 2735 bpf_prog_is_dev_bound(dst_prog->aux)) { 2736 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 2737 if (err) 2738 goto free_prog_sec; 2739 } 2740 2741 /* find program type: socket_filter vs tracing_filter */ 2742 err = find_prog_type(type, prog); 2743 if (err < 0) 2744 goto free_prog_sec; 2745 2746 prog->aux->load_time = ktime_get_boottime_ns(); 2747 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 2748 sizeof(attr->prog_name)); 2749 if (err < 0) 2750 goto free_prog_sec; 2751 2752 /* run eBPF verifier */ 2753 err = bpf_check(&prog, attr, uattr, uattr_size); 2754 if (err < 0) 2755 goto free_used_maps; 2756 2757 prog = bpf_prog_select_runtime(prog, &err); 2758 if (err < 0) 2759 goto free_used_maps; 2760 2761 err = bpf_prog_alloc_id(prog); 2762 if (err) 2763 goto free_used_maps; 2764 2765 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 2766 * effectively publicly exposed. However, retrieving via 2767 * bpf_prog_get_fd_by_id() will take another reference, 2768 * therefore it cannot be gone underneath us. 2769 * 2770 * Only for the time /after/ successful bpf_prog_new_fd() 2771 * and before returning to userspace, we might just hold 2772 * one reference and any parallel close on that fd could 2773 * rip everything out. Hence, below notifications must 2774 * happen before bpf_prog_new_fd(). 2775 * 2776 * Also, any failure handling from this point onwards must 2777 * be using bpf_prog_put() given the program is exposed. 2778 */ 2779 bpf_prog_kallsyms_add(prog); 2780 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 2781 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 2782 2783 err = bpf_prog_new_fd(prog); 2784 if (err < 0) 2785 bpf_prog_put(prog); 2786 return err; 2787 2788 free_used_maps: 2789 /* In case we have subprogs, we need to wait for a grace 2790 * period before we can tear down JIT memory since symbols 2791 * are already exposed under kallsyms. 2792 */ 2793 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 2794 return err; 2795 free_prog_sec: 2796 free_uid(prog->aux->user); 2797 security_bpf_prog_free(prog->aux); 2798 free_prog: 2799 if (prog->aux->attach_btf) 2800 btf_put(prog->aux->attach_btf); 2801 bpf_prog_free(prog); 2802 return err; 2803 } 2804 2805 #define BPF_OBJ_LAST_FIELD path_fd 2806 2807 static int bpf_obj_pin(const union bpf_attr *attr) 2808 { 2809 int path_fd; 2810 2811 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 2812 return -EINVAL; 2813 2814 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 2815 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 2816 return -EINVAL; 2817 2818 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 2819 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 2820 u64_to_user_ptr(attr->pathname)); 2821 } 2822 2823 static int bpf_obj_get(const union bpf_attr *attr) 2824 { 2825 int path_fd; 2826 2827 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 2828 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 2829 return -EINVAL; 2830 2831 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 2832 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 2833 return -EINVAL; 2834 2835 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 2836 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 2837 attr->file_flags); 2838 } 2839 2840 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 2841 const struct bpf_link_ops *ops, struct bpf_prog *prog) 2842 { 2843 atomic64_set(&link->refcnt, 1); 2844 link->type = type; 2845 link->id = 0; 2846 link->ops = ops; 2847 link->prog = prog; 2848 } 2849 2850 static void bpf_link_free_id(int id) 2851 { 2852 if (!id) 2853 return; 2854 2855 spin_lock_bh(&link_idr_lock); 2856 idr_remove(&link_idr, id); 2857 spin_unlock_bh(&link_idr_lock); 2858 } 2859 2860 /* Clean up bpf_link and corresponding anon_inode file and FD. After 2861 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 2862 * anon_inode's release() call. This helper marks bpf_link as 2863 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 2864 * is not decremented, it's the responsibility of a calling code that failed 2865 * to complete bpf_link initialization. 2866 * This helper eventually calls link's dealloc callback, but does not call 2867 * link's release callback. 2868 */ 2869 void bpf_link_cleanup(struct bpf_link_primer *primer) 2870 { 2871 primer->link->prog = NULL; 2872 bpf_link_free_id(primer->id); 2873 fput(primer->file); 2874 put_unused_fd(primer->fd); 2875 } 2876 2877 void bpf_link_inc(struct bpf_link *link) 2878 { 2879 atomic64_inc(&link->refcnt); 2880 } 2881 2882 /* bpf_link_free is guaranteed to be called from process context */ 2883 static void bpf_link_free(struct bpf_link *link) 2884 { 2885 bpf_link_free_id(link->id); 2886 if (link->prog) { 2887 /* detach BPF program, clean up used resources */ 2888 link->ops->release(link); 2889 bpf_prog_put(link->prog); 2890 } 2891 /* free bpf_link and its containing memory */ 2892 link->ops->dealloc(link); 2893 } 2894 2895 static void bpf_link_put_deferred(struct work_struct *work) 2896 { 2897 struct bpf_link *link = container_of(work, struct bpf_link, work); 2898 2899 bpf_link_free(link); 2900 } 2901 2902 /* bpf_link_put might be called from atomic context. It needs to be called 2903 * from sleepable context in order to acquire sleeping locks during the process. 2904 */ 2905 void bpf_link_put(struct bpf_link *link) 2906 { 2907 if (!atomic64_dec_and_test(&link->refcnt)) 2908 return; 2909 2910 INIT_WORK(&link->work, bpf_link_put_deferred); 2911 schedule_work(&link->work); 2912 } 2913 EXPORT_SYMBOL(bpf_link_put); 2914 2915 static void bpf_link_put_direct(struct bpf_link *link) 2916 { 2917 if (!atomic64_dec_and_test(&link->refcnt)) 2918 return; 2919 bpf_link_free(link); 2920 } 2921 2922 static int bpf_link_release(struct inode *inode, struct file *filp) 2923 { 2924 struct bpf_link *link = filp->private_data; 2925 2926 bpf_link_put_direct(link); 2927 return 0; 2928 } 2929 2930 #ifdef CONFIG_PROC_FS 2931 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 2932 #define BPF_MAP_TYPE(_id, _ops) 2933 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 2934 static const char *bpf_link_type_strs[] = { 2935 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 2936 #include <linux/bpf_types.h> 2937 }; 2938 #undef BPF_PROG_TYPE 2939 #undef BPF_MAP_TYPE 2940 #undef BPF_LINK_TYPE 2941 2942 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 2943 { 2944 const struct bpf_link *link = filp->private_data; 2945 const struct bpf_prog *prog = link->prog; 2946 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2947 2948 seq_printf(m, 2949 "link_type:\t%s\n" 2950 "link_id:\t%u\n", 2951 bpf_link_type_strs[link->type], 2952 link->id); 2953 if (prog) { 2954 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2955 seq_printf(m, 2956 "prog_tag:\t%s\n" 2957 "prog_id:\t%u\n", 2958 prog_tag, 2959 prog->aux->id); 2960 } 2961 if (link->ops->show_fdinfo) 2962 link->ops->show_fdinfo(link, m); 2963 } 2964 #endif 2965 2966 static const struct file_operations bpf_link_fops = { 2967 #ifdef CONFIG_PROC_FS 2968 .show_fdinfo = bpf_link_show_fdinfo, 2969 #endif 2970 .release = bpf_link_release, 2971 .read = bpf_dummy_read, 2972 .write = bpf_dummy_write, 2973 }; 2974 2975 static int bpf_link_alloc_id(struct bpf_link *link) 2976 { 2977 int id; 2978 2979 idr_preload(GFP_KERNEL); 2980 spin_lock_bh(&link_idr_lock); 2981 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 2982 spin_unlock_bh(&link_idr_lock); 2983 idr_preload_end(); 2984 2985 return id; 2986 } 2987 2988 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 2989 * reserving unused FD and allocating ID from link_idr. This is to be paired 2990 * with bpf_link_settle() to install FD and ID and expose bpf_link to 2991 * user-space, if bpf_link is successfully attached. If not, bpf_link and 2992 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 2993 * transient state is passed around in struct bpf_link_primer. 2994 * This is preferred way to create and initialize bpf_link, especially when 2995 * there are complicated and expensive operations in between creating bpf_link 2996 * itself and attaching it to BPF hook. By using bpf_link_prime() and 2997 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 2998 * expensive (and potentially failing) roll back operations in a rare case 2999 * that file, FD, or ID can't be allocated. 3000 */ 3001 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3002 { 3003 struct file *file; 3004 int fd, id; 3005 3006 fd = get_unused_fd_flags(O_CLOEXEC); 3007 if (fd < 0) 3008 return fd; 3009 3010 3011 id = bpf_link_alloc_id(link); 3012 if (id < 0) { 3013 put_unused_fd(fd); 3014 return id; 3015 } 3016 3017 file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC); 3018 if (IS_ERR(file)) { 3019 bpf_link_free_id(id); 3020 put_unused_fd(fd); 3021 return PTR_ERR(file); 3022 } 3023 3024 primer->link = link; 3025 primer->file = file; 3026 primer->fd = fd; 3027 primer->id = id; 3028 return 0; 3029 } 3030 3031 int bpf_link_settle(struct bpf_link_primer *primer) 3032 { 3033 /* make bpf_link fetchable by ID */ 3034 spin_lock_bh(&link_idr_lock); 3035 primer->link->id = primer->id; 3036 spin_unlock_bh(&link_idr_lock); 3037 /* make bpf_link fetchable by FD */ 3038 fd_install(primer->fd, primer->file); 3039 /* pass through installed FD */ 3040 return primer->fd; 3041 } 3042 3043 int bpf_link_new_fd(struct bpf_link *link) 3044 { 3045 return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC); 3046 } 3047 3048 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3049 { 3050 struct fd f = fdget(ufd); 3051 struct bpf_link *link; 3052 3053 if (!f.file) 3054 return ERR_PTR(-EBADF); 3055 if (f.file->f_op != &bpf_link_fops) { 3056 fdput(f); 3057 return ERR_PTR(-EINVAL); 3058 } 3059 3060 link = f.file->private_data; 3061 bpf_link_inc(link); 3062 fdput(f); 3063 3064 return link; 3065 } 3066 EXPORT_SYMBOL(bpf_link_get_from_fd); 3067 3068 static void bpf_tracing_link_release(struct bpf_link *link) 3069 { 3070 struct bpf_tracing_link *tr_link = 3071 container_of(link, struct bpf_tracing_link, link.link); 3072 3073 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3074 tr_link->trampoline)); 3075 3076 bpf_trampoline_put(tr_link->trampoline); 3077 3078 /* tgt_prog is NULL if target is a kernel function */ 3079 if (tr_link->tgt_prog) 3080 bpf_prog_put(tr_link->tgt_prog); 3081 } 3082 3083 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3084 { 3085 struct bpf_tracing_link *tr_link = 3086 container_of(link, struct bpf_tracing_link, link.link); 3087 3088 kfree(tr_link); 3089 } 3090 3091 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3092 struct seq_file *seq) 3093 { 3094 struct bpf_tracing_link *tr_link = 3095 container_of(link, struct bpf_tracing_link, link.link); 3096 u32 target_btf_id, target_obj_id; 3097 3098 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3099 &target_obj_id, &target_btf_id); 3100 seq_printf(seq, 3101 "attach_type:\t%d\n" 3102 "target_obj_id:\t%u\n" 3103 "target_btf_id:\t%u\n", 3104 tr_link->attach_type, 3105 target_obj_id, 3106 target_btf_id); 3107 } 3108 3109 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3110 struct bpf_link_info *info) 3111 { 3112 struct bpf_tracing_link *tr_link = 3113 container_of(link, struct bpf_tracing_link, link.link); 3114 3115 info->tracing.attach_type = tr_link->attach_type; 3116 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3117 &info->tracing.target_obj_id, 3118 &info->tracing.target_btf_id); 3119 3120 return 0; 3121 } 3122 3123 static const struct bpf_link_ops bpf_tracing_link_lops = { 3124 .release = bpf_tracing_link_release, 3125 .dealloc = bpf_tracing_link_dealloc, 3126 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3127 .fill_link_info = bpf_tracing_link_fill_link_info, 3128 }; 3129 3130 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3131 int tgt_prog_fd, 3132 u32 btf_id, 3133 u64 bpf_cookie) 3134 { 3135 struct bpf_link_primer link_primer; 3136 struct bpf_prog *tgt_prog = NULL; 3137 struct bpf_trampoline *tr = NULL; 3138 struct bpf_tracing_link *link; 3139 u64 key = 0; 3140 int err; 3141 3142 switch (prog->type) { 3143 case BPF_PROG_TYPE_TRACING: 3144 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3145 prog->expected_attach_type != BPF_TRACE_FEXIT && 3146 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3147 err = -EINVAL; 3148 goto out_put_prog; 3149 } 3150 break; 3151 case BPF_PROG_TYPE_EXT: 3152 if (prog->expected_attach_type != 0) { 3153 err = -EINVAL; 3154 goto out_put_prog; 3155 } 3156 break; 3157 case BPF_PROG_TYPE_LSM: 3158 if (prog->expected_attach_type != BPF_LSM_MAC) { 3159 err = -EINVAL; 3160 goto out_put_prog; 3161 } 3162 break; 3163 default: 3164 err = -EINVAL; 3165 goto out_put_prog; 3166 } 3167 3168 if (!!tgt_prog_fd != !!btf_id) { 3169 err = -EINVAL; 3170 goto out_put_prog; 3171 } 3172 3173 if (tgt_prog_fd) { 3174 /* For now we only allow new targets for BPF_PROG_TYPE_EXT */ 3175 if (prog->type != BPF_PROG_TYPE_EXT) { 3176 err = -EINVAL; 3177 goto out_put_prog; 3178 } 3179 3180 tgt_prog = bpf_prog_get(tgt_prog_fd); 3181 if (IS_ERR(tgt_prog)) { 3182 err = PTR_ERR(tgt_prog); 3183 tgt_prog = NULL; 3184 goto out_put_prog; 3185 } 3186 3187 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3188 } 3189 3190 link = kzalloc(sizeof(*link), GFP_USER); 3191 if (!link) { 3192 err = -ENOMEM; 3193 goto out_put_prog; 3194 } 3195 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3196 &bpf_tracing_link_lops, prog); 3197 link->attach_type = prog->expected_attach_type; 3198 link->link.cookie = bpf_cookie; 3199 3200 mutex_lock(&prog->aux->dst_mutex); 3201 3202 /* There are a few possible cases here: 3203 * 3204 * - if prog->aux->dst_trampoline is set, the program was just loaded 3205 * and not yet attached to anything, so we can use the values stored 3206 * in prog->aux 3207 * 3208 * - if prog->aux->dst_trampoline is NULL, the program has already been 3209 * attached to a target and its initial target was cleared (below) 3210 * 3211 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3212 * target_btf_id using the link_create API. 3213 * 3214 * - if tgt_prog == NULL when this function was called using the old 3215 * raw_tracepoint_open API, and we need a target from prog->aux 3216 * 3217 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3218 * was detached and is going for re-attachment. 3219 */ 3220 if (!prog->aux->dst_trampoline && !tgt_prog) { 3221 /* 3222 * Allow re-attach for TRACING and LSM programs. If it's 3223 * currently linked, bpf_trampoline_link_prog will fail. 3224 * EXT programs need to specify tgt_prog_fd, so they 3225 * re-attach in separate code path. 3226 */ 3227 if (prog->type != BPF_PROG_TYPE_TRACING && 3228 prog->type != BPF_PROG_TYPE_LSM) { 3229 err = -EINVAL; 3230 goto out_unlock; 3231 } 3232 btf_id = prog->aux->attach_btf_id; 3233 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3234 } 3235 3236 if (!prog->aux->dst_trampoline || 3237 (key && key != prog->aux->dst_trampoline->key)) { 3238 /* If there is no saved target, or the specified target is 3239 * different from the destination specified at load time, we 3240 * need a new trampoline and a check for compatibility 3241 */ 3242 struct bpf_attach_target_info tgt_info = {}; 3243 3244 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3245 &tgt_info); 3246 if (err) 3247 goto out_unlock; 3248 3249 if (tgt_info.tgt_mod) { 3250 module_put(prog->aux->mod); 3251 prog->aux->mod = tgt_info.tgt_mod; 3252 } 3253 3254 tr = bpf_trampoline_get(key, &tgt_info); 3255 if (!tr) { 3256 err = -ENOMEM; 3257 goto out_unlock; 3258 } 3259 } else { 3260 /* The caller didn't specify a target, or the target was the 3261 * same as the destination supplied during program load. This 3262 * means we can reuse the trampoline and reference from program 3263 * load time, and there is no need to allocate a new one. This 3264 * can only happen once for any program, as the saved values in 3265 * prog->aux are cleared below. 3266 */ 3267 tr = prog->aux->dst_trampoline; 3268 tgt_prog = prog->aux->dst_prog; 3269 } 3270 3271 err = bpf_link_prime(&link->link.link, &link_primer); 3272 if (err) 3273 goto out_unlock; 3274 3275 err = bpf_trampoline_link_prog(&link->link, tr); 3276 if (err) { 3277 bpf_link_cleanup(&link_primer); 3278 link = NULL; 3279 goto out_unlock; 3280 } 3281 3282 link->tgt_prog = tgt_prog; 3283 link->trampoline = tr; 3284 3285 /* Always clear the trampoline and target prog from prog->aux to make 3286 * sure the original attach destination is not kept alive after a 3287 * program is (re-)attached to another target. 3288 */ 3289 if (prog->aux->dst_prog && 3290 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3291 /* got extra prog ref from syscall, or attaching to different prog */ 3292 bpf_prog_put(prog->aux->dst_prog); 3293 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3294 /* we allocated a new trampoline, so free the old one */ 3295 bpf_trampoline_put(prog->aux->dst_trampoline); 3296 3297 prog->aux->dst_prog = NULL; 3298 prog->aux->dst_trampoline = NULL; 3299 mutex_unlock(&prog->aux->dst_mutex); 3300 3301 return bpf_link_settle(&link_primer); 3302 out_unlock: 3303 if (tr && tr != prog->aux->dst_trampoline) 3304 bpf_trampoline_put(tr); 3305 mutex_unlock(&prog->aux->dst_mutex); 3306 kfree(link); 3307 out_put_prog: 3308 if (tgt_prog_fd && tgt_prog) 3309 bpf_prog_put(tgt_prog); 3310 return err; 3311 } 3312 3313 struct bpf_raw_tp_link { 3314 struct bpf_link link; 3315 struct bpf_raw_event_map *btp; 3316 }; 3317 3318 static void bpf_raw_tp_link_release(struct bpf_link *link) 3319 { 3320 struct bpf_raw_tp_link *raw_tp = 3321 container_of(link, struct bpf_raw_tp_link, link); 3322 3323 bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog); 3324 bpf_put_raw_tracepoint(raw_tp->btp); 3325 } 3326 3327 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3328 { 3329 struct bpf_raw_tp_link *raw_tp = 3330 container_of(link, struct bpf_raw_tp_link, link); 3331 3332 kfree(raw_tp); 3333 } 3334 3335 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3336 struct seq_file *seq) 3337 { 3338 struct bpf_raw_tp_link *raw_tp_link = 3339 container_of(link, struct bpf_raw_tp_link, link); 3340 3341 seq_printf(seq, 3342 "tp_name:\t%s\n", 3343 raw_tp_link->btp->tp->name); 3344 } 3345 3346 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3347 u32 len) 3348 { 3349 if (ulen >= len + 1) { 3350 if (copy_to_user(ubuf, buf, len + 1)) 3351 return -EFAULT; 3352 } else { 3353 char zero = '\0'; 3354 3355 if (copy_to_user(ubuf, buf, ulen - 1)) 3356 return -EFAULT; 3357 if (put_user(zero, ubuf + ulen - 1)) 3358 return -EFAULT; 3359 return -ENOSPC; 3360 } 3361 3362 return 0; 3363 } 3364 3365 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3366 struct bpf_link_info *info) 3367 { 3368 struct bpf_raw_tp_link *raw_tp_link = 3369 container_of(link, struct bpf_raw_tp_link, link); 3370 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3371 const char *tp_name = raw_tp_link->btp->tp->name; 3372 u32 ulen = info->raw_tracepoint.tp_name_len; 3373 size_t tp_len = strlen(tp_name); 3374 3375 if (!ulen ^ !ubuf) 3376 return -EINVAL; 3377 3378 info->raw_tracepoint.tp_name_len = tp_len + 1; 3379 3380 if (!ubuf) 3381 return 0; 3382 3383 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3384 } 3385 3386 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3387 .release = bpf_raw_tp_link_release, 3388 .dealloc = bpf_raw_tp_link_dealloc, 3389 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3390 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3391 }; 3392 3393 #ifdef CONFIG_PERF_EVENTS 3394 struct bpf_perf_link { 3395 struct bpf_link link; 3396 struct file *perf_file; 3397 }; 3398 3399 static void bpf_perf_link_release(struct bpf_link *link) 3400 { 3401 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3402 struct perf_event *event = perf_link->perf_file->private_data; 3403 3404 perf_event_free_bpf_prog(event); 3405 fput(perf_link->perf_file); 3406 } 3407 3408 static void bpf_perf_link_dealloc(struct bpf_link *link) 3409 { 3410 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3411 3412 kfree(perf_link); 3413 } 3414 3415 static int bpf_perf_link_fill_common(const struct perf_event *event, 3416 char __user *uname, u32 ulen, 3417 u64 *probe_offset, u64 *probe_addr, 3418 u32 *fd_type, unsigned long *missed) 3419 { 3420 const char *buf; 3421 u32 prog_id; 3422 size_t len; 3423 int err; 3424 3425 if (!ulen ^ !uname) 3426 return -EINVAL; 3427 3428 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3429 probe_offset, probe_addr, missed); 3430 if (err) 3431 return err; 3432 if (!uname) 3433 return 0; 3434 if (buf) { 3435 len = strlen(buf); 3436 err = bpf_copy_to_user(uname, buf, ulen, len); 3437 if (err) 3438 return err; 3439 } else { 3440 char zero = '\0'; 3441 3442 if (put_user(zero, uname)) 3443 return -EFAULT; 3444 } 3445 return 0; 3446 } 3447 3448 #ifdef CONFIG_KPROBE_EVENTS 3449 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 3450 struct bpf_link_info *info) 3451 { 3452 unsigned long missed; 3453 char __user *uname; 3454 u64 addr, offset; 3455 u32 ulen, type; 3456 int err; 3457 3458 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 3459 ulen = info->perf_event.kprobe.name_len; 3460 err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, 3461 &type, &missed); 3462 if (err) 3463 return err; 3464 if (type == BPF_FD_TYPE_KRETPROBE) 3465 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 3466 else 3467 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 3468 3469 info->perf_event.kprobe.offset = offset; 3470 info->perf_event.kprobe.missed = missed; 3471 if (!kallsyms_show_value(current_cred())) 3472 addr = 0; 3473 info->perf_event.kprobe.addr = addr; 3474 return 0; 3475 } 3476 #endif 3477 3478 #ifdef CONFIG_UPROBE_EVENTS 3479 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 3480 struct bpf_link_info *info) 3481 { 3482 char __user *uname; 3483 u64 addr, offset; 3484 u32 ulen, type; 3485 int err; 3486 3487 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 3488 ulen = info->perf_event.uprobe.name_len; 3489 err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, 3490 &type, NULL); 3491 if (err) 3492 return err; 3493 3494 if (type == BPF_FD_TYPE_URETPROBE) 3495 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 3496 else 3497 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 3498 info->perf_event.uprobe.offset = offset; 3499 return 0; 3500 } 3501 #endif 3502 3503 static int bpf_perf_link_fill_probe(const struct perf_event *event, 3504 struct bpf_link_info *info) 3505 { 3506 #ifdef CONFIG_KPROBE_EVENTS 3507 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 3508 return bpf_perf_link_fill_kprobe(event, info); 3509 #endif 3510 #ifdef CONFIG_UPROBE_EVENTS 3511 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 3512 return bpf_perf_link_fill_uprobe(event, info); 3513 #endif 3514 return -EOPNOTSUPP; 3515 } 3516 3517 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 3518 struct bpf_link_info *info) 3519 { 3520 char __user *uname; 3521 u32 ulen; 3522 3523 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 3524 ulen = info->perf_event.tracepoint.name_len; 3525 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 3526 return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL); 3527 } 3528 3529 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 3530 struct bpf_link_info *info) 3531 { 3532 info->perf_event.event.type = event->attr.type; 3533 info->perf_event.event.config = event->attr.config; 3534 info->perf_event.type = BPF_PERF_EVENT_EVENT; 3535 return 0; 3536 } 3537 3538 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 3539 struct bpf_link_info *info) 3540 { 3541 struct bpf_perf_link *perf_link; 3542 const struct perf_event *event; 3543 3544 perf_link = container_of(link, struct bpf_perf_link, link); 3545 event = perf_get_event(perf_link->perf_file); 3546 if (IS_ERR(event)) 3547 return PTR_ERR(event); 3548 3549 switch (event->prog->type) { 3550 case BPF_PROG_TYPE_PERF_EVENT: 3551 return bpf_perf_link_fill_perf_event(event, info); 3552 case BPF_PROG_TYPE_TRACEPOINT: 3553 return bpf_perf_link_fill_tracepoint(event, info); 3554 case BPF_PROG_TYPE_KPROBE: 3555 return bpf_perf_link_fill_probe(event, info); 3556 default: 3557 return -EOPNOTSUPP; 3558 } 3559 } 3560 3561 static const struct bpf_link_ops bpf_perf_link_lops = { 3562 .release = bpf_perf_link_release, 3563 .dealloc = bpf_perf_link_dealloc, 3564 .fill_link_info = bpf_perf_link_fill_link_info, 3565 }; 3566 3567 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3568 { 3569 struct bpf_link_primer link_primer; 3570 struct bpf_perf_link *link; 3571 struct perf_event *event; 3572 struct file *perf_file; 3573 int err; 3574 3575 if (attr->link_create.flags) 3576 return -EINVAL; 3577 3578 perf_file = perf_event_get(attr->link_create.target_fd); 3579 if (IS_ERR(perf_file)) 3580 return PTR_ERR(perf_file); 3581 3582 link = kzalloc(sizeof(*link), GFP_USER); 3583 if (!link) { 3584 err = -ENOMEM; 3585 goto out_put_file; 3586 } 3587 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog); 3588 link->perf_file = perf_file; 3589 3590 err = bpf_link_prime(&link->link, &link_primer); 3591 if (err) { 3592 kfree(link); 3593 goto out_put_file; 3594 } 3595 3596 event = perf_file->private_data; 3597 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 3598 if (err) { 3599 bpf_link_cleanup(&link_primer); 3600 goto out_put_file; 3601 } 3602 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 3603 bpf_prog_inc(prog); 3604 3605 return bpf_link_settle(&link_primer); 3606 3607 out_put_file: 3608 fput(perf_file); 3609 return err; 3610 } 3611 #else 3612 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3613 { 3614 return -EOPNOTSUPP; 3615 } 3616 #endif /* CONFIG_PERF_EVENTS */ 3617 3618 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 3619 const char __user *user_tp_name) 3620 { 3621 struct bpf_link_primer link_primer; 3622 struct bpf_raw_tp_link *link; 3623 struct bpf_raw_event_map *btp; 3624 const char *tp_name; 3625 char buf[128]; 3626 int err; 3627 3628 switch (prog->type) { 3629 case BPF_PROG_TYPE_TRACING: 3630 case BPF_PROG_TYPE_EXT: 3631 case BPF_PROG_TYPE_LSM: 3632 if (user_tp_name) 3633 /* The attach point for this category of programs 3634 * should be specified via btf_id during program load. 3635 */ 3636 return -EINVAL; 3637 if (prog->type == BPF_PROG_TYPE_TRACING && 3638 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 3639 tp_name = prog->aux->attach_func_name; 3640 break; 3641 } 3642 return bpf_tracing_prog_attach(prog, 0, 0, 0); 3643 case BPF_PROG_TYPE_RAW_TRACEPOINT: 3644 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 3645 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 3646 return -EFAULT; 3647 buf[sizeof(buf) - 1] = 0; 3648 tp_name = buf; 3649 break; 3650 default: 3651 return -EINVAL; 3652 } 3653 3654 btp = bpf_get_raw_tracepoint(tp_name); 3655 if (!btp) 3656 return -ENOENT; 3657 3658 link = kzalloc(sizeof(*link), GFP_USER); 3659 if (!link) { 3660 err = -ENOMEM; 3661 goto out_put_btp; 3662 } 3663 bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 3664 &bpf_raw_tp_link_lops, prog); 3665 link->btp = btp; 3666 3667 err = bpf_link_prime(&link->link, &link_primer); 3668 if (err) { 3669 kfree(link); 3670 goto out_put_btp; 3671 } 3672 3673 err = bpf_probe_register(link->btp, prog); 3674 if (err) { 3675 bpf_link_cleanup(&link_primer); 3676 goto out_put_btp; 3677 } 3678 3679 return bpf_link_settle(&link_primer); 3680 3681 out_put_btp: 3682 bpf_put_raw_tracepoint(btp); 3683 return err; 3684 } 3685 3686 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd 3687 3688 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 3689 { 3690 struct bpf_prog *prog; 3691 int fd; 3692 3693 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 3694 return -EINVAL; 3695 3696 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 3697 if (IS_ERR(prog)) 3698 return PTR_ERR(prog); 3699 3700 fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name)); 3701 if (fd < 0) 3702 bpf_prog_put(prog); 3703 return fd; 3704 } 3705 3706 static enum bpf_prog_type 3707 attach_type_to_prog_type(enum bpf_attach_type attach_type) 3708 { 3709 switch (attach_type) { 3710 case BPF_CGROUP_INET_INGRESS: 3711 case BPF_CGROUP_INET_EGRESS: 3712 return BPF_PROG_TYPE_CGROUP_SKB; 3713 case BPF_CGROUP_INET_SOCK_CREATE: 3714 case BPF_CGROUP_INET_SOCK_RELEASE: 3715 case BPF_CGROUP_INET4_POST_BIND: 3716 case BPF_CGROUP_INET6_POST_BIND: 3717 return BPF_PROG_TYPE_CGROUP_SOCK; 3718 case BPF_CGROUP_INET4_BIND: 3719 case BPF_CGROUP_INET6_BIND: 3720 case BPF_CGROUP_INET4_CONNECT: 3721 case BPF_CGROUP_INET6_CONNECT: 3722 case BPF_CGROUP_UNIX_CONNECT: 3723 case BPF_CGROUP_INET4_GETPEERNAME: 3724 case BPF_CGROUP_INET6_GETPEERNAME: 3725 case BPF_CGROUP_UNIX_GETPEERNAME: 3726 case BPF_CGROUP_INET4_GETSOCKNAME: 3727 case BPF_CGROUP_INET6_GETSOCKNAME: 3728 case BPF_CGROUP_UNIX_GETSOCKNAME: 3729 case BPF_CGROUP_UDP4_SENDMSG: 3730 case BPF_CGROUP_UDP6_SENDMSG: 3731 case BPF_CGROUP_UNIX_SENDMSG: 3732 case BPF_CGROUP_UDP4_RECVMSG: 3733 case BPF_CGROUP_UDP6_RECVMSG: 3734 case BPF_CGROUP_UNIX_RECVMSG: 3735 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 3736 case BPF_CGROUP_SOCK_OPS: 3737 return BPF_PROG_TYPE_SOCK_OPS; 3738 case BPF_CGROUP_DEVICE: 3739 return BPF_PROG_TYPE_CGROUP_DEVICE; 3740 case BPF_SK_MSG_VERDICT: 3741 return BPF_PROG_TYPE_SK_MSG; 3742 case BPF_SK_SKB_STREAM_PARSER: 3743 case BPF_SK_SKB_STREAM_VERDICT: 3744 case BPF_SK_SKB_VERDICT: 3745 return BPF_PROG_TYPE_SK_SKB; 3746 case BPF_LIRC_MODE2: 3747 return BPF_PROG_TYPE_LIRC_MODE2; 3748 case BPF_FLOW_DISSECTOR: 3749 return BPF_PROG_TYPE_FLOW_DISSECTOR; 3750 case BPF_CGROUP_SYSCTL: 3751 return BPF_PROG_TYPE_CGROUP_SYSCTL; 3752 case BPF_CGROUP_GETSOCKOPT: 3753 case BPF_CGROUP_SETSOCKOPT: 3754 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 3755 case BPF_TRACE_ITER: 3756 case BPF_TRACE_RAW_TP: 3757 case BPF_TRACE_FENTRY: 3758 case BPF_TRACE_FEXIT: 3759 case BPF_MODIFY_RETURN: 3760 return BPF_PROG_TYPE_TRACING; 3761 case BPF_LSM_MAC: 3762 return BPF_PROG_TYPE_LSM; 3763 case BPF_SK_LOOKUP: 3764 return BPF_PROG_TYPE_SK_LOOKUP; 3765 case BPF_XDP: 3766 return BPF_PROG_TYPE_XDP; 3767 case BPF_LSM_CGROUP: 3768 return BPF_PROG_TYPE_LSM; 3769 case BPF_TCX_INGRESS: 3770 case BPF_TCX_EGRESS: 3771 case BPF_NETKIT_PRIMARY: 3772 case BPF_NETKIT_PEER: 3773 return BPF_PROG_TYPE_SCHED_CLS; 3774 default: 3775 return BPF_PROG_TYPE_UNSPEC; 3776 } 3777 } 3778 3779 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 3780 enum bpf_attach_type attach_type) 3781 { 3782 enum bpf_prog_type ptype; 3783 3784 switch (prog->type) { 3785 case BPF_PROG_TYPE_CGROUP_SOCK: 3786 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3787 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3788 case BPF_PROG_TYPE_SK_LOOKUP: 3789 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 3790 case BPF_PROG_TYPE_CGROUP_SKB: 3791 if (!capable(CAP_NET_ADMIN)) 3792 /* cg-skb progs can be loaded by unpriv user. 3793 * check permissions at attach time. 3794 */ 3795 return -EPERM; 3796 return prog->enforce_expected_attach_type && 3797 prog->expected_attach_type != attach_type ? 3798 -EINVAL : 0; 3799 case BPF_PROG_TYPE_EXT: 3800 return 0; 3801 case BPF_PROG_TYPE_NETFILTER: 3802 if (attach_type != BPF_NETFILTER) 3803 return -EINVAL; 3804 return 0; 3805 case BPF_PROG_TYPE_PERF_EVENT: 3806 case BPF_PROG_TYPE_TRACEPOINT: 3807 if (attach_type != BPF_PERF_EVENT) 3808 return -EINVAL; 3809 return 0; 3810 case BPF_PROG_TYPE_KPROBE: 3811 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 3812 attach_type != BPF_TRACE_KPROBE_MULTI) 3813 return -EINVAL; 3814 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 3815 attach_type != BPF_TRACE_UPROBE_MULTI) 3816 return -EINVAL; 3817 if (attach_type != BPF_PERF_EVENT && 3818 attach_type != BPF_TRACE_KPROBE_MULTI && 3819 attach_type != BPF_TRACE_UPROBE_MULTI) 3820 return -EINVAL; 3821 return 0; 3822 case BPF_PROG_TYPE_SCHED_CLS: 3823 if (attach_type != BPF_TCX_INGRESS && 3824 attach_type != BPF_TCX_EGRESS && 3825 attach_type != BPF_NETKIT_PRIMARY && 3826 attach_type != BPF_NETKIT_PEER) 3827 return -EINVAL; 3828 return 0; 3829 default: 3830 ptype = attach_type_to_prog_type(attach_type); 3831 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 3832 return -EINVAL; 3833 return 0; 3834 } 3835 } 3836 3837 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 3838 3839 #define BPF_F_ATTACH_MASK_BASE \ 3840 (BPF_F_ALLOW_OVERRIDE | \ 3841 BPF_F_ALLOW_MULTI | \ 3842 BPF_F_REPLACE) 3843 3844 #define BPF_F_ATTACH_MASK_MPROG \ 3845 (BPF_F_REPLACE | \ 3846 BPF_F_BEFORE | \ 3847 BPF_F_AFTER | \ 3848 BPF_F_ID | \ 3849 BPF_F_LINK) 3850 3851 static int bpf_prog_attach(const union bpf_attr *attr) 3852 { 3853 enum bpf_prog_type ptype; 3854 struct bpf_prog *prog; 3855 int ret; 3856 3857 if (CHECK_ATTR(BPF_PROG_ATTACH)) 3858 return -EINVAL; 3859 3860 ptype = attach_type_to_prog_type(attr->attach_type); 3861 if (ptype == BPF_PROG_TYPE_UNSPEC) 3862 return -EINVAL; 3863 if (bpf_mprog_supported(ptype)) { 3864 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 3865 return -EINVAL; 3866 } else { 3867 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 3868 return -EINVAL; 3869 if (attr->relative_fd || 3870 attr->expected_revision) 3871 return -EINVAL; 3872 } 3873 3874 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 3875 if (IS_ERR(prog)) 3876 return PTR_ERR(prog); 3877 3878 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 3879 bpf_prog_put(prog); 3880 return -EINVAL; 3881 } 3882 3883 switch (ptype) { 3884 case BPF_PROG_TYPE_SK_SKB: 3885 case BPF_PROG_TYPE_SK_MSG: 3886 ret = sock_map_get_from_fd(attr, prog); 3887 break; 3888 case BPF_PROG_TYPE_LIRC_MODE2: 3889 ret = lirc_prog_attach(attr, prog); 3890 break; 3891 case BPF_PROG_TYPE_FLOW_DISSECTOR: 3892 ret = netns_bpf_prog_attach(attr, prog); 3893 break; 3894 case BPF_PROG_TYPE_CGROUP_DEVICE: 3895 case BPF_PROG_TYPE_CGROUP_SKB: 3896 case BPF_PROG_TYPE_CGROUP_SOCK: 3897 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3898 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3899 case BPF_PROG_TYPE_CGROUP_SYSCTL: 3900 case BPF_PROG_TYPE_SOCK_OPS: 3901 case BPF_PROG_TYPE_LSM: 3902 if (ptype == BPF_PROG_TYPE_LSM && 3903 prog->expected_attach_type != BPF_LSM_CGROUP) 3904 ret = -EINVAL; 3905 else 3906 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 3907 break; 3908 case BPF_PROG_TYPE_SCHED_CLS: 3909 if (attr->attach_type == BPF_TCX_INGRESS || 3910 attr->attach_type == BPF_TCX_EGRESS) 3911 ret = tcx_prog_attach(attr, prog); 3912 else 3913 ret = netkit_prog_attach(attr, prog); 3914 break; 3915 default: 3916 ret = -EINVAL; 3917 } 3918 3919 if (ret) 3920 bpf_prog_put(prog); 3921 return ret; 3922 } 3923 3924 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 3925 3926 static int bpf_prog_detach(const union bpf_attr *attr) 3927 { 3928 struct bpf_prog *prog = NULL; 3929 enum bpf_prog_type ptype; 3930 int ret; 3931 3932 if (CHECK_ATTR(BPF_PROG_DETACH)) 3933 return -EINVAL; 3934 3935 ptype = attach_type_to_prog_type(attr->attach_type); 3936 if (bpf_mprog_supported(ptype)) { 3937 if (ptype == BPF_PROG_TYPE_UNSPEC) 3938 return -EINVAL; 3939 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 3940 return -EINVAL; 3941 if (attr->attach_bpf_fd) { 3942 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 3943 if (IS_ERR(prog)) 3944 return PTR_ERR(prog); 3945 } 3946 } else if (attr->attach_flags || 3947 attr->relative_fd || 3948 attr->expected_revision) { 3949 return -EINVAL; 3950 } 3951 3952 switch (ptype) { 3953 case BPF_PROG_TYPE_SK_MSG: 3954 case BPF_PROG_TYPE_SK_SKB: 3955 ret = sock_map_prog_detach(attr, ptype); 3956 break; 3957 case BPF_PROG_TYPE_LIRC_MODE2: 3958 ret = lirc_prog_detach(attr); 3959 break; 3960 case BPF_PROG_TYPE_FLOW_DISSECTOR: 3961 ret = netns_bpf_prog_detach(attr, ptype); 3962 break; 3963 case BPF_PROG_TYPE_CGROUP_DEVICE: 3964 case BPF_PROG_TYPE_CGROUP_SKB: 3965 case BPF_PROG_TYPE_CGROUP_SOCK: 3966 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 3967 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 3968 case BPF_PROG_TYPE_CGROUP_SYSCTL: 3969 case BPF_PROG_TYPE_SOCK_OPS: 3970 case BPF_PROG_TYPE_LSM: 3971 ret = cgroup_bpf_prog_detach(attr, ptype); 3972 break; 3973 case BPF_PROG_TYPE_SCHED_CLS: 3974 if (attr->attach_type == BPF_TCX_INGRESS || 3975 attr->attach_type == BPF_TCX_EGRESS) 3976 ret = tcx_prog_detach(attr, prog); 3977 else 3978 ret = netkit_prog_detach(attr, prog); 3979 break; 3980 default: 3981 ret = -EINVAL; 3982 } 3983 3984 if (prog) 3985 bpf_prog_put(prog); 3986 return ret; 3987 } 3988 3989 #define BPF_PROG_QUERY_LAST_FIELD query.revision 3990 3991 static int bpf_prog_query(const union bpf_attr *attr, 3992 union bpf_attr __user *uattr) 3993 { 3994 if (!capable(CAP_NET_ADMIN)) 3995 return -EPERM; 3996 if (CHECK_ATTR(BPF_PROG_QUERY)) 3997 return -EINVAL; 3998 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 3999 return -EINVAL; 4000 4001 switch (attr->query.attach_type) { 4002 case BPF_CGROUP_INET_INGRESS: 4003 case BPF_CGROUP_INET_EGRESS: 4004 case BPF_CGROUP_INET_SOCK_CREATE: 4005 case BPF_CGROUP_INET_SOCK_RELEASE: 4006 case BPF_CGROUP_INET4_BIND: 4007 case BPF_CGROUP_INET6_BIND: 4008 case BPF_CGROUP_INET4_POST_BIND: 4009 case BPF_CGROUP_INET6_POST_BIND: 4010 case BPF_CGROUP_INET4_CONNECT: 4011 case BPF_CGROUP_INET6_CONNECT: 4012 case BPF_CGROUP_UNIX_CONNECT: 4013 case BPF_CGROUP_INET4_GETPEERNAME: 4014 case BPF_CGROUP_INET6_GETPEERNAME: 4015 case BPF_CGROUP_UNIX_GETPEERNAME: 4016 case BPF_CGROUP_INET4_GETSOCKNAME: 4017 case BPF_CGROUP_INET6_GETSOCKNAME: 4018 case BPF_CGROUP_UNIX_GETSOCKNAME: 4019 case BPF_CGROUP_UDP4_SENDMSG: 4020 case BPF_CGROUP_UDP6_SENDMSG: 4021 case BPF_CGROUP_UNIX_SENDMSG: 4022 case BPF_CGROUP_UDP4_RECVMSG: 4023 case BPF_CGROUP_UDP6_RECVMSG: 4024 case BPF_CGROUP_UNIX_RECVMSG: 4025 case BPF_CGROUP_SOCK_OPS: 4026 case BPF_CGROUP_DEVICE: 4027 case BPF_CGROUP_SYSCTL: 4028 case BPF_CGROUP_GETSOCKOPT: 4029 case BPF_CGROUP_SETSOCKOPT: 4030 case BPF_LSM_CGROUP: 4031 return cgroup_bpf_prog_query(attr, uattr); 4032 case BPF_LIRC_MODE2: 4033 return lirc_prog_query(attr, uattr); 4034 case BPF_FLOW_DISSECTOR: 4035 case BPF_SK_LOOKUP: 4036 return netns_bpf_prog_query(attr, uattr); 4037 case BPF_SK_SKB_STREAM_PARSER: 4038 case BPF_SK_SKB_STREAM_VERDICT: 4039 case BPF_SK_MSG_VERDICT: 4040 case BPF_SK_SKB_VERDICT: 4041 return sock_map_bpf_prog_query(attr, uattr); 4042 case BPF_TCX_INGRESS: 4043 case BPF_TCX_EGRESS: 4044 return tcx_prog_query(attr, uattr); 4045 case BPF_NETKIT_PRIMARY: 4046 case BPF_NETKIT_PEER: 4047 return netkit_prog_query(attr, uattr); 4048 default: 4049 return -EINVAL; 4050 } 4051 } 4052 4053 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4054 4055 static int bpf_prog_test_run(const union bpf_attr *attr, 4056 union bpf_attr __user *uattr) 4057 { 4058 struct bpf_prog *prog; 4059 int ret = -ENOTSUPP; 4060 4061 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4062 return -EINVAL; 4063 4064 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4065 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4066 return -EINVAL; 4067 4068 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4069 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4070 return -EINVAL; 4071 4072 prog = bpf_prog_get(attr->test.prog_fd); 4073 if (IS_ERR(prog)) 4074 return PTR_ERR(prog); 4075 4076 if (prog->aux->ops->test_run) 4077 ret = prog->aux->ops->test_run(prog, attr, uattr); 4078 4079 bpf_prog_put(prog); 4080 return ret; 4081 } 4082 4083 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4084 4085 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4086 union bpf_attr __user *uattr, 4087 struct idr *idr, 4088 spinlock_t *lock) 4089 { 4090 u32 next_id = attr->start_id; 4091 int err = 0; 4092 4093 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4094 return -EINVAL; 4095 4096 if (!capable(CAP_SYS_ADMIN)) 4097 return -EPERM; 4098 4099 next_id++; 4100 spin_lock_bh(lock); 4101 if (!idr_get_next(idr, &next_id)) 4102 err = -ENOENT; 4103 spin_unlock_bh(lock); 4104 4105 if (!err) 4106 err = put_user(next_id, &uattr->next_id); 4107 4108 return err; 4109 } 4110 4111 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4112 { 4113 struct bpf_map *map; 4114 4115 spin_lock_bh(&map_idr_lock); 4116 again: 4117 map = idr_get_next(&map_idr, id); 4118 if (map) { 4119 map = __bpf_map_inc_not_zero(map, false); 4120 if (IS_ERR(map)) { 4121 (*id)++; 4122 goto again; 4123 } 4124 } 4125 spin_unlock_bh(&map_idr_lock); 4126 4127 return map; 4128 } 4129 4130 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4131 { 4132 struct bpf_prog *prog; 4133 4134 spin_lock_bh(&prog_idr_lock); 4135 again: 4136 prog = idr_get_next(&prog_idr, id); 4137 if (prog) { 4138 prog = bpf_prog_inc_not_zero(prog); 4139 if (IS_ERR(prog)) { 4140 (*id)++; 4141 goto again; 4142 } 4143 } 4144 spin_unlock_bh(&prog_idr_lock); 4145 4146 return prog; 4147 } 4148 4149 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4150 4151 struct bpf_prog *bpf_prog_by_id(u32 id) 4152 { 4153 struct bpf_prog *prog; 4154 4155 if (!id) 4156 return ERR_PTR(-ENOENT); 4157 4158 spin_lock_bh(&prog_idr_lock); 4159 prog = idr_find(&prog_idr, id); 4160 if (prog) 4161 prog = bpf_prog_inc_not_zero(prog); 4162 else 4163 prog = ERR_PTR(-ENOENT); 4164 spin_unlock_bh(&prog_idr_lock); 4165 return prog; 4166 } 4167 4168 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4169 { 4170 struct bpf_prog *prog; 4171 u32 id = attr->prog_id; 4172 int fd; 4173 4174 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4175 return -EINVAL; 4176 4177 if (!capable(CAP_SYS_ADMIN)) 4178 return -EPERM; 4179 4180 prog = bpf_prog_by_id(id); 4181 if (IS_ERR(prog)) 4182 return PTR_ERR(prog); 4183 4184 fd = bpf_prog_new_fd(prog); 4185 if (fd < 0) 4186 bpf_prog_put(prog); 4187 4188 return fd; 4189 } 4190 4191 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4192 4193 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4194 { 4195 struct bpf_map *map; 4196 u32 id = attr->map_id; 4197 int f_flags; 4198 int fd; 4199 4200 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4201 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4202 return -EINVAL; 4203 4204 if (!capable(CAP_SYS_ADMIN)) 4205 return -EPERM; 4206 4207 f_flags = bpf_get_file_flag(attr->open_flags); 4208 if (f_flags < 0) 4209 return f_flags; 4210 4211 spin_lock_bh(&map_idr_lock); 4212 map = idr_find(&map_idr, id); 4213 if (map) 4214 map = __bpf_map_inc_not_zero(map, true); 4215 else 4216 map = ERR_PTR(-ENOENT); 4217 spin_unlock_bh(&map_idr_lock); 4218 4219 if (IS_ERR(map)) 4220 return PTR_ERR(map); 4221 4222 fd = bpf_map_new_fd(map, f_flags); 4223 if (fd < 0) 4224 bpf_map_put_with_uref(map); 4225 4226 return fd; 4227 } 4228 4229 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4230 unsigned long addr, u32 *off, 4231 u32 *type) 4232 { 4233 const struct bpf_map *map; 4234 int i; 4235 4236 mutex_lock(&prog->aux->used_maps_mutex); 4237 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4238 map = prog->aux->used_maps[i]; 4239 if (map == (void *)addr) { 4240 *type = BPF_PSEUDO_MAP_FD; 4241 goto out; 4242 } 4243 if (!map->ops->map_direct_value_meta) 4244 continue; 4245 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4246 *type = BPF_PSEUDO_MAP_VALUE; 4247 goto out; 4248 } 4249 } 4250 map = NULL; 4251 4252 out: 4253 mutex_unlock(&prog->aux->used_maps_mutex); 4254 return map; 4255 } 4256 4257 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 4258 const struct cred *f_cred) 4259 { 4260 const struct bpf_map *map; 4261 struct bpf_insn *insns; 4262 u32 off, type; 4263 u64 imm; 4264 u8 code; 4265 int i; 4266 4267 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 4268 GFP_USER); 4269 if (!insns) 4270 return insns; 4271 4272 for (i = 0; i < prog->len; i++) { 4273 code = insns[i].code; 4274 4275 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 4276 insns[i].code = BPF_JMP | BPF_CALL; 4277 insns[i].imm = BPF_FUNC_tail_call; 4278 /* fall-through */ 4279 } 4280 if (code == (BPF_JMP | BPF_CALL) || 4281 code == (BPF_JMP | BPF_CALL_ARGS)) { 4282 if (code == (BPF_JMP | BPF_CALL_ARGS)) 4283 insns[i].code = BPF_JMP | BPF_CALL; 4284 if (!bpf_dump_raw_ok(f_cred)) 4285 insns[i].imm = 0; 4286 continue; 4287 } 4288 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 4289 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 4290 continue; 4291 } 4292 4293 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 4294 continue; 4295 4296 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 4297 map = bpf_map_from_imm(prog, imm, &off, &type); 4298 if (map) { 4299 insns[i].src_reg = type; 4300 insns[i].imm = map->id; 4301 insns[i + 1].imm = off; 4302 continue; 4303 } 4304 } 4305 4306 return insns; 4307 } 4308 4309 static int set_info_rec_size(struct bpf_prog_info *info) 4310 { 4311 /* 4312 * Ensure info.*_rec_size is the same as kernel expected size 4313 * 4314 * or 4315 * 4316 * Only allow zero *_rec_size if both _rec_size and _cnt are 4317 * zero. In this case, the kernel will set the expected 4318 * _rec_size back to the info. 4319 */ 4320 4321 if ((info->nr_func_info || info->func_info_rec_size) && 4322 info->func_info_rec_size != sizeof(struct bpf_func_info)) 4323 return -EINVAL; 4324 4325 if ((info->nr_line_info || info->line_info_rec_size) && 4326 info->line_info_rec_size != sizeof(struct bpf_line_info)) 4327 return -EINVAL; 4328 4329 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 4330 info->jited_line_info_rec_size != sizeof(__u64)) 4331 return -EINVAL; 4332 4333 info->func_info_rec_size = sizeof(struct bpf_func_info); 4334 info->line_info_rec_size = sizeof(struct bpf_line_info); 4335 info->jited_line_info_rec_size = sizeof(__u64); 4336 4337 return 0; 4338 } 4339 4340 static int bpf_prog_get_info_by_fd(struct file *file, 4341 struct bpf_prog *prog, 4342 const union bpf_attr *attr, 4343 union bpf_attr __user *uattr) 4344 { 4345 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4346 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 4347 struct bpf_prog_info info; 4348 u32 info_len = attr->info.info_len; 4349 struct bpf_prog_kstats stats; 4350 char __user *uinsns; 4351 u32 ulen; 4352 int err; 4353 4354 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4355 if (err) 4356 return err; 4357 info_len = min_t(u32, sizeof(info), info_len); 4358 4359 memset(&info, 0, sizeof(info)); 4360 if (copy_from_user(&info, uinfo, info_len)) 4361 return -EFAULT; 4362 4363 info.type = prog->type; 4364 info.id = prog->aux->id; 4365 info.load_time = prog->aux->load_time; 4366 info.created_by_uid = from_kuid_munged(current_user_ns(), 4367 prog->aux->user->uid); 4368 info.gpl_compatible = prog->gpl_compatible; 4369 4370 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 4371 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 4372 4373 mutex_lock(&prog->aux->used_maps_mutex); 4374 ulen = info.nr_map_ids; 4375 info.nr_map_ids = prog->aux->used_map_cnt; 4376 ulen = min_t(u32, info.nr_map_ids, ulen); 4377 if (ulen) { 4378 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 4379 u32 i; 4380 4381 for (i = 0; i < ulen; i++) 4382 if (put_user(prog->aux->used_maps[i]->id, 4383 &user_map_ids[i])) { 4384 mutex_unlock(&prog->aux->used_maps_mutex); 4385 return -EFAULT; 4386 } 4387 } 4388 mutex_unlock(&prog->aux->used_maps_mutex); 4389 4390 err = set_info_rec_size(&info); 4391 if (err) 4392 return err; 4393 4394 bpf_prog_get_stats(prog, &stats); 4395 info.run_time_ns = stats.nsecs; 4396 info.run_cnt = stats.cnt; 4397 info.recursion_misses = stats.misses; 4398 4399 info.verified_insns = prog->aux->verified_insns; 4400 4401 if (!bpf_capable()) { 4402 info.jited_prog_len = 0; 4403 info.xlated_prog_len = 0; 4404 info.nr_jited_ksyms = 0; 4405 info.nr_jited_func_lens = 0; 4406 info.nr_func_info = 0; 4407 info.nr_line_info = 0; 4408 info.nr_jited_line_info = 0; 4409 goto done; 4410 } 4411 4412 ulen = info.xlated_prog_len; 4413 info.xlated_prog_len = bpf_prog_insn_size(prog); 4414 if (info.xlated_prog_len && ulen) { 4415 struct bpf_insn *insns_sanitized; 4416 bool fault; 4417 4418 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) { 4419 info.xlated_prog_insns = 0; 4420 goto done; 4421 } 4422 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 4423 if (!insns_sanitized) 4424 return -ENOMEM; 4425 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 4426 ulen = min_t(u32, info.xlated_prog_len, ulen); 4427 fault = copy_to_user(uinsns, insns_sanitized, ulen); 4428 kfree(insns_sanitized); 4429 if (fault) 4430 return -EFAULT; 4431 } 4432 4433 if (bpf_prog_is_offloaded(prog->aux)) { 4434 err = bpf_prog_offload_info_fill(&info, prog); 4435 if (err) 4436 return err; 4437 goto done; 4438 } 4439 4440 /* NOTE: the following code is supposed to be skipped for offload. 4441 * bpf_prog_offload_info_fill() is the place to fill similar fields 4442 * for offload. 4443 */ 4444 ulen = info.jited_prog_len; 4445 if (prog->aux->func_cnt) { 4446 u32 i; 4447 4448 info.jited_prog_len = 0; 4449 for (i = 0; i < prog->aux->func_cnt; i++) 4450 info.jited_prog_len += prog->aux->func[i]->jited_len; 4451 } else { 4452 info.jited_prog_len = prog->jited_len; 4453 } 4454 4455 if (info.jited_prog_len && ulen) { 4456 if (bpf_dump_raw_ok(file->f_cred)) { 4457 uinsns = u64_to_user_ptr(info.jited_prog_insns); 4458 ulen = min_t(u32, info.jited_prog_len, ulen); 4459 4460 /* for multi-function programs, copy the JITed 4461 * instructions for all the functions 4462 */ 4463 if (prog->aux->func_cnt) { 4464 u32 len, free, i; 4465 u8 *img; 4466 4467 free = ulen; 4468 for (i = 0; i < prog->aux->func_cnt; i++) { 4469 len = prog->aux->func[i]->jited_len; 4470 len = min_t(u32, len, free); 4471 img = (u8 *) prog->aux->func[i]->bpf_func; 4472 if (copy_to_user(uinsns, img, len)) 4473 return -EFAULT; 4474 uinsns += len; 4475 free -= len; 4476 if (!free) 4477 break; 4478 } 4479 } else { 4480 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 4481 return -EFAULT; 4482 } 4483 } else { 4484 info.jited_prog_insns = 0; 4485 } 4486 } 4487 4488 ulen = info.nr_jited_ksyms; 4489 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 4490 if (ulen) { 4491 if (bpf_dump_raw_ok(file->f_cred)) { 4492 unsigned long ksym_addr; 4493 u64 __user *user_ksyms; 4494 u32 i; 4495 4496 /* copy the address of the kernel symbol 4497 * corresponding to each function 4498 */ 4499 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 4500 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 4501 if (prog->aux->func_cnt) { 4502 for (i = 0; i < ulen; i++) { 4503 ksym_addr = (unsigned long) 4504 prog->aux->func[i]->bpf_func; 4505 if (put_user((u64) ksym_addr, 4506 &user_ksyms[i])) 4507 return -EFAULT; 4508 } 4509 } else { 4510 ksym_addr = (unsigned long) prog->bpf_func; 4511 if (put_user((u64) ksym_addr, &user_ksyms[0])) 4512 return -EFAULT; 4513 } 4514 } else { 4515 info.jited_ksyms = 0; 4516 } 4517 } 4518 4519 ulen = info.nr_jited_func_lens; 4520 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 4521 if (ulen) { 4522 if (bpf_dump_raw_ok(file->f_cred)) { 4523 u32 __user *user_lens; 4524 u32 func_len, i; 4525 4526 /* copy the JITed image lengths for each function */ 4527 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 4528 user_lens = u64_to_user_ptr(info.jited_func_lens); 4529 if (prog->aux->func_cnt) { 4530 for (i = 0; i < ulen; i++) { 4531 func_len = 4532 prog->aux->func[i]->jited_len; 4533 if (put_user(func_len, &user_lens[i])) 4534 return -EFAULT; 4535 } 4536 } else { 4537 func_len = prog->jited_len; 4538 if (put_user(func_len, &user_lens[0])) 4539 return -EFAULT; 4540 } 4541 } else { 4542 info.jited_func_lens = 0; 4543 } 4544 } 4545 4546 if (prog->aux->btf) 4547 info.btf_id = btf_obj_id(prog->aux->btf); 4548 info.attach_btf_id = prog->aux->attach_btf_id; 4549 if (attach_btf) 4550 info.attach_btf_obj_id = btf_obj_id(attach_btf); 4551 4552 ulen = info.nr_func_info; 4553 info.nr_func_info = prog->aux->func_info_cnt; 4554 if (info.nr_func_info && ulen) { 4555 char __user *user_finfo; 4556 4557 user_finfo = u64_to_user_ptr(info.func_info); 4558 ulen = min_t(u32, info.nr_func_info, ulen); 4559 if (copy_to_user(user_finfo, prog->aux->func_info, 4560 info.func_info_rec_size * ulen)) 4561 return -EFAULT; 4562 } 4563 4564 ulen = info.nr_line_info; 4565 info.nr_line_info = prog->aux->nr_linfo; 4566 if (info.nr_line_info && ulen) { 4567 __u8 __user *user_linfo; 4568 4569 user_linfo = u64_to_user_ptr(info.line_info); 4570 ulen = min_t(u32, info.nr_line_info, ulen); 4571 if (copy_to_user(user_linfo, prog->aux->linfo, 4572 info.line_info_rec_size * ulen)) 4573 return -EFAULT; 4574 } 4575 4576 ulen = info.nr_jited_line_info; 4577 if (prog->aux->jited_linfo) 4578 info.nr_jited_line_info = prog->aux->nr_linfo; 4579 else 4580 info.nr_jited_line_info = 0; 4581 if (info.nr_jited_line_info && ulen) { 4582 if (bpf_dump_raw_ok(file->f_cred)) { 4583 unsigned long line_addr; 4584 __u64 __user *user_linfo; 4585 u32 i; 4586 4587 user_linfo = u64_to_user_ptr(info.jited_line_info); 4588 ulen = min_t(u32, info.nr_jited_line_info, ulen); 4589 for (i = 0; i < ulen; i++) { 4590 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 4591 if (put_user((__u64)line_addr, &user_linfo[i])) 4592 return -EFAULT; 4593 } 4594 } else { 4595 info.jited_line_info = 0; 4596 } 4597 } 4598 4599 ulen = info.nr_prog_tags; 4600 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 4601 if (ulen) { 4602 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 4603 u32 i; 4604 4605 user_prog_tags = u64_to_user_ptr(info.prog_tags); 4606 ulen = min_t(u32, info.nr_prog_tags, ulen); 4607 if (prog->aux->func_cnt) { 4608 for (i = 0; i < ulen; i++) { 4609 if (copy_to_user(user_prog_tags[i], 4610 prog->aux->func[i]->tag, 4611 BPF_TAG_SIZE)) 4612 return -EFAULT; 4613 } 4614 } else { 4615 if (copy_to_user(user_prog_tags[0], 4616 prog->tag, BPF_TAG_SIZE)) 4617 return -EFAULT; 4618 } 4619 } 4620 4621 done: 4622 if (copy_to_user(uinfo, &info, info_len) || 4623 put_user(info_len, &uattr->info.info_len)) 4624 return -EFAULT; 4625 4626 return 0; 4627 } 4628 4629 static int bpf_map_get_info_by_fd(struct file *file, 4630 struct bpf_map *map, 4631 const union bpf_attr *attr, 4632 union bpf_attr __user *uattr) 4633 { 4634 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4635 struct bpf_map_info info; 4636 u32 info_len = attr->info.info_len; 4637 int err; 4638 4639 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4640 if (err) 4641 return err; 4642 info_len = min_t(u32, sizeof(info), info_len); 4643 4644 memset(&info, 0, sizeof(info)); 4645 info.type = map->map_type; 4646 info.id = map->id; 4647 info.key_size = map->key_size; 4648 info.value_size = map->value_size; 4649 info.max_entries = map->max_entries; 4650 info.map_flags = map->map_flags; 4651 info.map_extra = map->map_extra; 4652 memcpy(info.name, map->name, sizeof(map->name)); 4653 4654 if (map->btf) { 4655 info.btf_id = btf_obj_id(map->btf); 4656 info.btf_key_type_id = map->btf_key_type_id; 4657 info.btf_value_type_id = map->btf_value_type_id; 4658 } 4659 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 4660 4661 if (bpf_map_is_offloaded(map)) { 4662 err = bpf_map_offload_info_fill(&info, map); 4663 if (err) 4664 return err; 4665 } 4666 4667 if (copy_to_user(uinfo, &info, info_len) || 4668 put_user(info_len, &uattr->info.info_len)) 4669 return -EFAULT; 4670 4671 return 0; 4672 } 4673 4674 static int bpf_btf_get_info_by_fd(struct file *file, 4675 struct btf *btf, 4676 const union bpf_attr *attr, 4677 union bpf_attr __user *uattr) 4678 { 4679 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4680 u32 info_len = attr->info.info_len; 4681 int err; 4682 4683 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 4684 if (err) 4685 return err; 4686 4687 return btf_get_info_by_fd(btf, attr, uattr); 4688 } 4689 4690 static int bpf_link_get_info_by_fd(struct file *file, 4691 struct bpf_link *link, 4692 const union bpf_attr *attr, 4693 union bpf_attr __user *uattr) 4694 { 4695 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4696 struct bpf_link_info info; 4697 u32 info_len = attr->info.info_len; 4698 int err; 4699 4700 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4701 if (err) 4702 return err; 4703 info_len = min_t(u32, sizeof(info), info_len); 4704 4705 memset(&info, 0, sizeof(info)); 4706 if (copy_from_user(&info, uinfo, info_len)) 4707 return -EFAULT; 4708 4709 info.type = link->type; 4710 info.id = link->id; 4711 if (link->prog) 4712 info.prog_id = link->prog->aux->id; 4713 4714 if (link->ops->fill_link_info) { 4715 err = link->ops->fill_link_info(link, &info); 4716 if (err) 4717 return err; 4718 } 4719 4720 if (copy_to_user(uinfo, &info, info_len) || 4721 put_user(info_len, &uattr->info.info_len)) 4722 return -EFAULT; 4723 4724 return 0; 4725 } 4726 4727 4728 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 4729 4730 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 4731 union bpf_attr __user *uattr) 4732 { 4733 int ufd = attr->info.bpf_fd; 4734 struct fd f; 4735 int err; 4736 4737 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 4738 return -EINVAL; 4739 4740 f = fdget(ufd); 4741 if (!f.file) 4742 return -EBADFD; 4743 4744 if (f.file->f_op == &bpf_prog_fops) 4745 err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr, 4746 uattr); 4747 else if (f.file->f_op == &bpf_map_fops) 4748 err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr, 4749 uattr); 4750 else if (f.file->f_op == &btf_fops) 4751 err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr); 4752 else if (f.file->f_op == &bpf_link_fops) 4753 err = bpf_link_get_info_by_fd(f.file, f.file->private_data, 4754 attr, uattr); 4755 else 4756 err = -EINVAL; 4757 4758 fdput(f); 4759 return err; 4760 } 4761 4762 #define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size 4763 4764 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) 4765 { 4766 if (CHECK_ATTR(BPF_BTF_LOAD)) 4767 return -EINVAL; 4768 4769 if (!bpf_capable()) 4770 return -EPERM; 4771 4772 return btf_new_fd(attr, uattr, uattr_size); 4773 } 4774 4775 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id 4776 4777 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 4778 { 4779 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 4780 return -EINVAL; 4781 4782 if (!capable(CAP_SYS_ADMIN)) 4783 return -EPERM; 4784 4785 return btf_get_fd_by_id(attr->btf_id); 4786 } 4787 4788 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 4789 union bpf_attr __user *uattr, 4790 u32 prog_id, u32 fd_type, 4791 const char *buf, u64 probe_offset, 4792 u64 probe_addr) 4793 { 4794 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 4795 u32 len = buf ? strlen(buf) : 0, input_len; 4796 int err = 0; 4797 4798 if (put_user(len, &uattr->task_fd_query.buf_len)) 4799 return -EFAULT; 4800 input_len = attr->task_fd_query.buf_len; 4801 if (input_len && ubuf) { 4802 if (!len) { 4803 /* nothing to copy, just make ubuf NULL terminated */ 4804 char zero = '\0'; 4805 4806 if (put_user(zero, ubuf)) 4807 return -EFAULT; 4808 } else if (input_len >= len + 1) { 4809 /* ubuf can hold the string with NULL terminator */ 4810 if (copy_to_user(ubuf, buf, len + 1)) 4811 return -EFAULT; 4812 } else { 4813 /* ubuf cannot hold the string with NULL terminator, 4814 * do a partial copy with NULL terminator. 4815 */ 4816 char zero = '\0'; 4817 4818 err = -ENOSPC; 4819 if (copy_to_user(ubuf, buf, input_len - 1)) 4820 return -EFAULT; 4821 if (put_user(zero, ubuf + input_len - 1)) 4822 return -EFAULT; 4823 } 4824 } 4825 4826 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 4827 put_user(fd_type, &uattr->task_fd_query.fd_type) || 4828 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 4829 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 4830 return -EFAULT; 4831 4832 return err; 4833 } 4834 4835 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 4836 4837 static int bpf_task_fd_query(const union bpf_attr *attr, 4838 union bpf_attr __user *uattr) 4839 { 4840 pid_t pid = attr->task_fd_query.pid; 4841 u32 fd = attr->task_fd_query.fd; 4842 const struct perf_event *event; 4843 struct task_struct *task; 4844 struct file *file; 4845 int err; 4846 4847 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 4848 return -EINVAL; 4849 4850 if (!capable(CAP_SYS_ADMIN)) 4851 return -EPERM; 4852 4853 if (attr->task_fd_query.flags != 0) 4854 return -EINVAL; 4855 4856 rcu_read_lock(); 4857 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 4858 rcu_read_unlock(); 4859 if (!task) 4860 return -ENOENT; 4861 4862 err = 0; 4863 file = fget_task(task, fd); 4864 put_task_struct(task); 4865 if (!file) 4866 return -EBADF; 4867 4868 if (file->f_op == &bpf_link_fops) { 4869 struct bpf_link *link = file->private_data; 4870 4871 if (link->ops == &bpf_raw_tp_link_lops) { 4872 struct bpf_raw_tp_link *raw_tp = 4873 container_of(link, struct bpf_raw_tp_link, link); 4874 struct bpf_raw_event_map *btp = raw_tp->btp; 4875 4876 err = bpf_task_fd_query_copy(attr, uattr, 4877 raw_tp->link.prog->aux->id, 4878 BPF_FD_TYPE_RAW_TRACEPOINT, 4879 btp->tp->name, 0, 0); 4880 goto put_file; 4881 } 4882 goto out_not_supp; 4883 } 4884 4885 event = perf_get_event(file); 4886 if (!IS_ERR(event)) { 4887 u64 probe_offset, probe_addr; 4888 u32 prog_id, fd_type; 4889 const char *buf; 4890 4891 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 4892 &buf, &probe_offset, 4893 &probe_addr, NULL); 4894 if (!err) 4895 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 4896 fd_type, buf, 4897 probe_offset, 4898 probe_addr); 4899 goto put_file; 4900 } 4901 4902 out_not_supp: 4903 err = -ENOTSUPP; 4904 put_file: 4905 fput(file); 4906 return err; 4907 } 4908 4909 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 4910 4911 #define BPF_DO_BATCH(fn, ...) \ 4912 do { \ 4913 if (!fn) { \ 4914 err = -ENOTSUPP; \ 4915 goto err_put; \ 4916 } \ 4917 err = fn(__VA_ARGS__); \ 4918 } while (0) 4919 4920 static int bpf_map_do_batch(const union bpf_attr *attr, 4921 union bpf_attr __user *uattr, 4922 int cmd) 4923 { 4924 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 4925 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 4926 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 4927 struct bpf_map *map; 4928 int err, ufd; 4929 struct fd f; 4930 4931 if (CHECK_ATTR(BPF_MAP_BATCH)) 4932 return -EINVAL; 4933 4934 ufd = attr->batch.map_fd; 4935 f = fdget(ufd); 4936 map = __bpf_map_get(f); 4937 if (IS_ERR(map)) 4938 return PTR_ERR(map); 4939 if (has_write) 4940 bpf_map_write_active_inc(map); 4941 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 4942 err = -EPERM; 4943 goto err_put; 4944 } 4945 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 4946 err = -EPERM; 4947 goto err_put; 4948 } 4949 4950 if (cmd == BPF_MAP_LOOKUP_BATCH) 4951 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 4952 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 4953 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 4954 else if (cmd == BPF_MAP_UPDATE_BATCH) 4955 BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr); 4956 else 4957 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 4958 err_put: 4959 if (has_write) { 4960 maybe_wait_bpf_programs(map); 4961 bpf_map_write_active_dec(map); 4962 } 4963 fdput(f); 4964 return err; 4965 } 4966 4967 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 4968 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 4969 { 4970 struct bpf_prog *prog; 4971 int ret; 4972 4973 if (CHECK_ATTR(BPF_LINK_CREATE)) 4974 return -EINVAL; 4975 4976 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 4977 return bpf_struct_ops_link_create(attr); 4978 4979 prog = bpf_prog_get(attr->link_create.prog_fd); 4980 if (IS_ERR(prog)) 4981 return PTR_ERR(prog); 4982 4983 ret = bpf_prog_attach_check_attach_type(prog, 4984 attr->link_create.attach_type); 4985 if (ret) 4986 goto out; 4987 4988 switch (prog->type) { 4989 case BPF_PROG_TYPE_CGROUP_SKB: 4990 case BPF_PROG_TYPE_CGROUP_SOCK: 4991 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4992 case BPF_PROG_TYPE_SOCK_OPS: 4993 case BPF_PROG_TYPE_CGROUP_DEVICE: 4994 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4995 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4996 ret = cgroup_bpf_link_attach(attr, prog); 4997 break; 4998 case BPF_PROG_TYPE_EXT: 4999 ret = bpf_tracing_prog_attach(prog, 5000 attr->link_create.target_fd, 5001 attr->link_create.target_btf_id, 5002 attr->link_create.tracing.cookie); 5003 break; 5004 case BPF_PROG_TYPE_LSM: 5005 case BPF_PROG_TYPE_TRACING: 5006 if (attr->link_create.attach_type != prog->expected_attach_type) { 5007 ret = -EINVAL; 5008 goto out; 5009 } 5010 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5011 ret = bpf_raw_tp_link_attach(prog, NULL); 5012 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5013 ret = bpf_iter_link_attach(attr, uattr, prog); 5014 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5015 ret = cgroup_bpf_link_attach(attr, prog); 5016 else 5017 ret = bpf_tracing_prog_attach(prog, 5018 attr->link_create.target_fd, 5019 attr->link_create.target_btf_id, 5020 attr->link_create.tracing.cookie); 5021 break; 5022 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5023 case BPF_PROG_TYPE_SK_LOOKUP: 5024 ret = netns_bpf_link_create(attr, prog); 5025 break; 5026 #ifdef CONFIG_NET 5027 case BPF_PROG_TYPE_XDP: 5028 ret = bpf_xdp_link_attach(attr, prog); 5029 break; 5030 case BPF_PROG_TYPE_SCHED_CLS: 5031 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5032 attr->link_create.attach_type == BPF_TCX_EGRESS) 5033 ret = tcx_link_attach(attr, prog); 5034 else 5035 ret = netkit_link_attach(attr, prog); 5036 break; 5037 case BPF_PROG_TYPE_NETFILTER: 5038 ret = bpf_nf_link_attach(attr, prog); 5039 break; 5040 #endif 5041 case BPF_PROG_TYPE_PERF_EVENT: 5042 case BPF_PROG_TYPE_TRACEPOINT: 5043 ret = bpf_perf_link_attach(attr, prog); 5044 break; 5045 case BPF_PROG_TYPE_KPROBE: 5046 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5047 ret = bpf_perf_link_attach(attr, prog); 5048 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI) 5049 ret = bpf_kprobe_multi_link_attach(attr, prog); 5050 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI) 5051 ret = bpf_uprobe_multi_link_attach(attr, prog); 5052 break; 5053 default: 5054 ret = -EINVAL; 5055 } 5056 5057 out: 5058 if (ret < 0) 5059 bpf_prog_put(prog); 5060 return ret; 5061 } 5062 5063 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5064 { 5065 struct bpf_map *new_map, *old_map = NULL; 5066 int ret; 5067 5068 new_map = bpf_map_get(attr->link_update.new_map_fd); 5069 if (IS_ERR(new_map)) 5070 return PTR_ERR(new_map); 5071 5072 if (attr->link_update.flags & BPF_F_REPLACE) { 5073 old_map = bpf_map_get(attr->link_update.old_map_fd); 5074 if (IS_ERR(old_map)) { 5075 ret = PTR_ERR(old_map); 5076 goto out_put; 5077 } 5078 } else if (attr->link_update.old_map_fd) { 5079 ret = -EINVAL; 5080 goto out_put; 5081 } 5082 5083 ret = link->ops->update_map(link, new_map, old_map); 5084 5085 if (old_map) 5086 bpf_map_put(old_map); 5087 out_put: 5088 bpf_map_put(new_map); 5089 return ret; 5090 } 5091 5092 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5093 5094 static int link_update(union bpf_attr *attr) 5095 { 5096 struct bpf_prog *old_prog = NULL, *new_prog; 5097 struct bpf_link *link; 5098 u32 flags; 5099 int ret; 5100 5101 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5102 return -EINVAL; 5103 5104 flags = attr->link_update.flags; 5105 if (flags & ~BPF_F_REPLACE) 5106 return -EINVAL; 5107 5108 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5109 if (IS_ERR(link)) 5110 return PTR_ERR(link); 5111 5112 if (link->ops->update_map) { 5113 ret = link_update_map(link, attr); 5114 goto out_put_link; 5115 } 5116 5117 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5118 if (IS_ERR(new_prog)) { 5119 ret = PTR_ERR(new_prog); 5120 goto out_put_link; 5121 } 5122 5123 if (flags & BPF_F_REPLACE) { 5124 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5125 if (IS_ERR(old_prog)) { 5126 ret = PTR_ERR(old_prog); 5127 old_prog = NULL; 5128 goto out_put_progs; 5129 } 5130 } else if (attr->link_update.old_prog_fd) { 5131 ret = -EINVAL; 5132 goto out_put_progs; 5133 } 5134 5135 if (link->ops->update_prog) 5136 ret = link->ops->update_prog(link, new_prog, old_prog); 5137 else 5138 ret = -EINVAL; 5139 5140 out_put_progs: 5141 if (old_prog) 5142 bpf_prog_put(old_prog); 5143 if (ret) 5144 bpf_prog_put(new_prog); 5145 out_put_link: 5146 bpf_link_put_direct(link); 5147 return ret; 5148 } 5149 5150 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5151 5152 static int link_detach(union bpf_attr *attr) 5153 { 5154 struct bpf_link *link; 5155 int ret; 5156 5157 if (CHECK_ATTR(BPF_LINK_DETACH)) 5158 return -EINVAL; 5159 5160 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 5161 if (IS_ERR(link)) 5162 return PTR_ERR(link); 5163 5164 if (link->ops->detach) 5165 ret = link->ops->detach(link); 5166 else 5167 ret = -EOPNOTSUPP; 5168 5169 bpf_link_put_direct(link); 5170 return ret; 5171 } 5172 5173 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 5174 { 5175 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 5176 } 5177 5178 struct bpf_link *bpf_link_by_id(u32 id) 5179 { 5180 struct bpf_link *link; 5181 5182 if (!id) 5183 return ERR_PTR(-ENOENT); 5184 5185 spin_lock_bh(&link_idr_lock); 5186 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 5187 link = idr_find(&link_idr, id); 5188 if (link) { 5189 if (link->id) 5190 link = bpf_link_inc_not_zero(link); 5191 else 5192 link = ERR_PTR(-EAGAIN); 5193 } else { 5194 link = ERR_PTR(-ENOENT); 5195 } 5196 spin_unlock_bh(&link_idr_lock); 5197 return link; 5198 } 5199 5200 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 5201 { 5202 struct bpf_link *link; 5203 5204 spin_lock_bh(&link_idr_lock); 5205 again: 5206 link = idr_get_next(&link_idr, id); 5207 if (link) { 5208 link = bpf_link_inc_not_zero(link); 5209 if (IS_ERR(link)) { 5210 (*id)++; 5211 goto again; 5212 } 5213 } 5214 spin_unlock_bh(&link_idr_lock); 5215 5216 return link; 5217 } 5218 5219 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 5220 5221 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 5222 { 5223 struct bpf_link *link; 5224 u32 id = attr->link_id; 5225 int fd; 5226 5227 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 5228 return -EINVAL; 5229 5230 if (!capable(CAP_SYS_ADMIN)) 5231 return -EPERM; 5232 5233 link = bpf_link_by_id(id); 5234 if (IS_ERR(link)) 5235 return PTR_ERR(link); 5236 5237 fd = bpf_link_new_fd(link); 5238 if (fd < 0) 5239 bpf_link_put_direct(link); 5240 5241 return fd; 5242 } 5243 5244 DEFINE_MUTEX(bpf_stats_enabled_mutex); 5245 5246 static int bpf_stats_release(struct inode *inode, struct file *file) 5247 { 5248 mutex_lock(&bpf_stats_enabled_mutex); 5249 static_key_slow_dec(&bpf_stats_enabled_key.key); 5250 mutex_unlock(&bpf_stats_enabled_mutex); 5251 return 0; 5252 } 5253 5254 static const struct file_operations bpf_stats_fops = { 5255 .release = bpf_stats_release, 5256 }; 5257 5258 static int bpf_enable_runtime_stats(void) 5259 { 5260 int fd; 5261 5262 mutex_lock(&bpf_stats_enabled_mutex); 5263 5264 /* Set a very high limit to avoid overflow */ 5265 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 5266 mutex_unlock(&bpf_stats_enabled_mutex); 5267 return -EBUSY; 5268 } 5269 5270 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 5271 if (fd >= 0) 5272 static_key_slow_inc(&bpf_stats_enabled_key.key); 5273 5274 mutex_unlock(&bpf_stats_enabled_mutex); 5275 return fd; 5276 } 5277 5278 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 5279 5280 static int bpf_enable_stats(union bpf_attr *attr) 5281 { 5282 5283 if (CHECK_ATTR(BPF_ENABLE_STATS)) 5284 return -EINVAL; 5285 5286 if (!capable(CAP_SYS_ADMIN)) 5287 return -EPERM; 5288 5289 switch (attr->enable_stats.type) { 5290 case BPF_STATS_RUN_TIME: 5291 return bpf_enable_runtime_stats(); 5292 default: 5293 break; 5294 } 5295 return -EINVAL; 5296 } 5297 5298 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 5299 5300 static int bpf_iter_create(union bpf_attr *attr) 5301 { 5302 struct bpf_link *link; 5303 int err; 5304 5305 if (CHECK_ATTR(BPF_ITER_CREATE)) 5306 return -EINVAL; 5307 5308 if (attr->iter_create.flags) 5309 return -EINVAL; 5310 5311 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 5312 if (IS_ERR(link)) 5313 return PTR_ERR(link); 5314 5315 err = bpf_iter_new_fd(link); 5316 bpf_link_put_direct(link); 5317 5318 return err; 5319 } 5320 5321 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 5322 5323 static int bpf_prog_bind_map(union bpf_attr *attr) 5324 { 5325 struct bpf_prog *prog; 5326 struct bpf_map *map; 5327 struct bpf_map **used_maps_old, **used_maps_new; 5328 int i, ret = 0; 5329 5330 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 5331 return -EINVAL; 5332 5333 if (attr->prog_bind_map.flags) 5334 return -EINVAL; 5335 5336 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 5337 if (IS_ERR(prog)) 5338 return PTR_ERR(prog); 5339 5340 map = bpf_map_get(attr->prog_bind_map.map_fd); 5341 if (IS_ERR(map)) { 5342 ret = PTR_ERR(map); 5343 goto out_prog_put; 5344 } 5345 5346 mutex_lock(&prog->aux->used_maps_mutex); 5347 5348 used_maps_old = prog->aux->used_maps; 5349 5350 for (i = 0; i < prog->aux->used_map_cnt; i++) 5351 if (used_maps_old[i] == map) { 5352 bpf_map_put(map); 5353 goto out_unlock; 5354 } 5355 5356 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, 5357 sizeof(used_maps_new[0]), 5358 GFP_KERNEL); 5359 if (!used_maps_new) { 5360 ret = -ENOMEM; 5361 goto out_unlock; 5362 } 5363 5364 /* The bpf program will not access the bpf map, but for the sake of 5365 * simplicity, increase sleepable_refcnt for sleepable program as well. 5366 */ 5367 if (prog->aux->sleepable) 5368 atomic64_inc(&map->sleepable_refcnt); 5369 memcpy(used_maps_new, used_maps_old, 5370 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 5371 used_maps_new[prog->aux->used_map_cnt] = map; 5372 5373 prog->aux->used_map_cnt++; 5374 prog->aux->used_maps = used_maps_new; 5375 5376 kfree(used_maps_old); 5377 5378 out_unlock: 5379 mutex_unlock(&prog->aux->used_maps_mutex); 5380 5381 if (ret) 5382 bpf_map_put(map); 5383 out_prog_put: 5384 bpf_prog_put(prog); 5385 return ret; 5386 } 5387 5388 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size) 5389 { 5390 union bpf_attr attr; 5391 int err; 5392 5393 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 5394 if (err) 5395 return err; 5396 size = min_t(u32, size, sizeof(attr)); 5397 5398 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 5399 memset(&attr, 0, sizeof(attr)); 5400 if (copy_from_bpfptr(&attr, uattr, size) != 0) 5401 return -EFAULT; 5402 5403 err = security_bpf(cmd, &attr, size); 5404 if (err < 0) 5405 return err; 5406 5407 switch (cmd) { 5408 case BPF_MAP_CREATE: 5409 err = map_create(&attr); 5410 break; 5411 case BPF_MAP_LOOKUP_ELEM: 5412 err = map_lookup_elem(&attr); 5413 break; 5414 case BPF_MAP_UPDATE_ELEM: 5415 err = map_update_elem(&attr, uattr); 5416 break; 5417 case BPF_MAP_DELETE_ELEM: 5418 err = map_delete_elem(&attr, uattr); 5419 break; 5420 case BPF_MAP_GET_NEXT_KEY: 5421 err = map_get_next_key(&attr); 5422 break; 5423 case BPF_MAP_FREEZE: 5424 err = map_freeze(&attr); 5425 break; 5426 case BPF_PROG_LOAD: 5427 err = bpf_prog_load(&attr, uattr, size); 5428 break; 5429 case BPF_OBJ_PIN: 5430 err = bpf_obj_pin(&attr); 5431 break; 5432 case BPF_OBJ_GET: 5433 err = bpf_obj_get(&attr); 5434 break; 5435 case BPF_PROG_ATTACH: 5436 err = bpf_prog_attach(&attr); 5437 break; 5438 case BPF_PROG_DETACH: 5439 err = bpf_prog_detach(&attr); 5440 break; 5441 case BPF_PROG_QUERY: 5442 err = bpf_prog_query(&attr, uattr.user); 5443 break; 5444 case BPF_PROG_TEST_RUN: 5445 err = bpf_prog_test_run(&attr, uattr.user); 5446 break; 5447 case BPF_PROG_GET_NEXT_ID: 5448 err = bpf_obj_get_next_id(&attr, uattr.user, 5449 &prog_idr, &prog_idr_lock); 5450 break; 5451 case BPF_MAP_GET_NEXT_ID: 5452 err = bpf_obj_get_next_id(&attr, uattr.user, 5453 &map_idr, &map_idr_lock); 5454 break; 5455 case BPF_BTF_GET_NEXT_ID: 5456 err = bpf_obj_get_next_id(&attr, uattr.user, 5457 &btf_idr, &btf_idr_lock); 5458 break; 5459 case BPF_PROG_GET_FD_BY_ID: 5460 err = bpf_prog_get_fd_by_id(&attr); 5461 break; 5462 case BPF_MAP_GET_FD_BY_ID: 5463 err = bpf_map_get_fd_by_id(&attr); 5464 break; 5465 case BPF_OBJ_GET_INFO_BY_FD: 5466 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 5467 break; 5468 case BPF_RAW_TRACEPOINT_OPEN: 5469 err = bpf_raw_tracepoint_open(&attr); 5470 break; 5471 case BPF_BTF_LOAD: 5472 err = bpf_btf_load(&attr, uattr, size); 5473 break; 5474 case BPF_BTF_GET_FD_BY_ID: 5475 err = bpf_btf_get_fd_by_id(&attr); 5476 break; 5477 case BPF_TASK_FD_QUERY: 5478 err = bpf_task_fd_query(&attr, uattr.user); 5479 break; 5480 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 5481 err = map_lookup_and_delete_elem(&attr); 5482 break; 5483 case BPF_MAP_LOOKUP_BATCH: 5484 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 5485 break; 5486 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 5487 err = bpf_map_do_batch(&attr, uattr.user, 5488 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 5489 break; 5490 case BPF_MAP_UPDATE_BATCH: 5491 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 5492 break; 5493 case BPF_MAP_DELETE_BATCH: 5494 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 5495 break; 5496 case BPF_LINK_CREATE: 5497 err = link_create(&attr, uattr); 5498 break; 5499 case BPF_LINK_UPDATE: 5500 err = link_update(&attr); 5501 break; 5502 case BPF_LINK_GET_FD_BY_ID: 5503 err = bpf_link_get_fd_by_id(&attr); 5504 break; 5505 case BPF_LINK_GET_NEXT_ID: 5506 err = bpf_obj_get_next_id(&attr, uattr.user, 5507 &link_idr, &link_idr_lock); 5508 break; 5509 case BPF_ENABLE_STATS: 5510 err = bpf_enable_stats(&attr); 5511 break; 5512 case BPF_ITER_CREATE: 5513 err = bpf_iter_create(&attr); 5514 break; 5515 case BPF_LINK_DETACH: 5516 err = link_detach(&attr); 5517 break; 5518 case BPF_PROG_BIND_MAP: 5519 err = bpf_prog_bind_map(&attr); 5520 break; 5521 default: 5522 err = -EINVAL; 5523 break; 5524 } 5525 5526 return err; 5527 } 5528 5529 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) 5530 { 5531 return __sys_bpf(cmd, USER_BPFPTR(uattr), size); 5532 } 5533 5534 static bool syscall_prog_is_valid_access(int off, int size, 5535 enum bpf_access_type type, 5536 const struct bpf_prog *prog, 5537 struct bpf_insn_access_aux *info) 5538 { 5539 if (off < 0 || off >= U16_MAX) 5540 return false; 5541 if (off % size != 0) 5542 return false; 5543 return true; 5544 } 5545 5546 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 5547 { 5548 switch (cmd) { 5549 case BPF_MAP_CREATE: 5550 case BPF_MAP_DELETE_ELEM: 5551 case BPF_MAP_UPDATE_ELEM: 5552 case BPF_MAP_FREEZE: 5553 case BPF_MAP_GET_FD_BY_ID: 5554 case BPF_PROG_LOAD: 5555 case BPF_BTF_LOAD: 5556 case BPF_LINK_CREATE: 5557 case BPF_RAW_TRACEPOINT_OPEN: 5558 break; 5559 default: 5560 return -EINVAL; 5561 } 5562 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); 5563 } 5564 5565 5566 /* To shut up -Wmissing-prototypes. 5567 * This function is used by the kernel light skeleton 5568 * to load bpf programs when modules are loaded or during kernel boot. 5569 * See tools/lib/bpf/skel_internal.h 5570 */ 5571 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 5572 5573 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 5574 { 5575 struct bpf_prog * __maybe_unused prog; 5576 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 5577 5578 switch (cmd) { 5579 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 5580 case BPF_PROG_TEST_RUN: 5581 if (attr->test.data_in || attr->test.data_out || 5582 attr->test.ctx_out || attr->test.duration || 5583 attr->test.repeat || attr->test.flags) 5584 return -EINVAL; 5585 5586 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 5587 if (IS_ERR(prog)) 5588 return PTR_ERR(prog); 5589 5590 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 5591 attr->test.ctx_size_in > U16_MAX) { 5592 bpf_prog_put(prog); 5593 return -EINVAL; 5594 } 5595 5596 run_ctx.bpf_cookie = 0; 5597 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 5598 /* recursion detected */ 5599 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 5600 bpf_prog_put(prog); 5601 return -EBUSY; 5602 } 5603 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 5604 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 5605 &run_ctx); 5606 bpf_prog_put(prog); 5607 return 0; 5608 #endif 5609 default: 5610 return ____bpf_sys_bpf(cmd, attr, size); 5611 } 5612 } 5613 EXPORT_SYMBOL(kern_sys_bpf); 5614 5615 static const struct bpf_func_proto bpf_sys_bpf_proto = { 5616 .func = bpf_sys_bpf, 5617 .gpl_only = false, 5618 .ret_type = RET_INTEGER, 5619 .arg1_type = ARG_ANYTHING, 5620 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 5621 .arg3_type = ARG_CONST_SIZE, 5622 }; 5623 5624 const struct bpf_func_proto * __weak 5625 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5626 { 5627 return bpf_base_func_proto(func_id); 5628 } 5629 5630 BPF_CALL_1(bpf_sys_close, u32, fd) 5631 { 5632 /* When bpf program calls this helper there should not be 5633 * an fdget() without matching completed fdput(). 5634 * This helper is allowed in the following callchain only: 5635 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 5636 */ 5637 return close_fd(fd); 5638 } 5639 5640 static const struct bpf_func_proto bpf_sys_close_proto = { 5641 .func = bpf_sys_close, 5642 .gpl_only = false, 5643 .ret_type = RET_INTEGER, 5644 .arg1_type = ARG_ANYTHING, 5645 }; 5646 5647 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 5648 { 5649 if (flags) 5650 return -EINVAL; 5651 5652 if (name_sz <= 1 || name[name_sz - 1]) 5653 return -EINVAL; 5654 5655 if (!bpf_dump_raw_ok(current_cred())) 5656 return -EPERM; 5657 5658 *res = kallsyms_lookup_name(name); 5659 return *res ? 0 : -ENOENT; 5660 } 5661 5662 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 5663 .func = bpf_kallsyms_lookup_name, 5664 .gpl_only = false, 5665 .ret_type = RET_INTEGER, 5666 .arg1_type = ARG_PTR_TO_MEM, 5667 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 5668 .arg3_type = ARG_ANYTHING, 5669 .arg4_type = ARG_PTR_TO_LONG, 5670 }; 5671 5672 static const struct bpf_func_proto * 5673 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5674 { 5675 switch (func_id) { 5676 case BPF_FUNC_sys_bpf: 5677 return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto; 5678 case BPF_FUNC_btf_find_by_name_kind: 5679 return &bpf_btf_find_by_name_kind_proto; 5680 case BPF_FUNC_sys_close: 5681 return &bpf_sys_close_proto; 5682 case BPF_FUNC_kallsyms_lookup_name: 5683 return &bpf_kallsyms_lookup_name_proto; 5684 default: 5685 return tracing_prog_func_proto(func_id, prog); 5686 } 5687 } 5688 5689 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 5690 .get_func_proto = syscall_prog_func_proto, 5691 .is_valid_access = syscall_prog_is_valid_access, 5692 }; 5693 5694 const struct bpf_prog_ops bpf_syscall_prog_ops = { 5695 .test_run = bpf_prog_test_run_syscall, 5696 }; 5697 5698 #ifdef CONFIG_SYSCTL 5699 static int bpf_stats_handler(struct ctl_table *table, int write, 5700 void *buffer, size_t *lenp, loff_t *ppos) 5701 { 5702 struct static_key *key = (struct static_key *)table->data; 5703 static int saved_val; 5704 int val, ret; 5705 struct ctl_table tmp = { 5706 .data = &val, 5707 .maxlen = sizeof(val), 5708 .mode = table->mode, 5709 .extra1 = SYSCTL_ZERO, 5710 .extra2 = SYSCTL_ONE, 5711 }; 5712 5713 if (write && !capable(CAP_SYS_ADMIN)) 5714 return -EPERM; 5715 5716 mutex_lock(&bpf_stats_enabled_mutex); 5717 val = saved_val; 5718 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5719 if (write && !ret && val != saved_val) { 5720 if (val) 5721 static_key_slow_inc(key); 5722 else 5723 static_key_slow_dec(key); 5724 saved_val = val; 5725 } 5726 mutex_unlock(&bpf_stats_enabled_mutex); 5727 return ret; 5728 } 5729 5730 void __weak unpriv_ebpf_notify(int new_state) 5731 { 5732 } 5733 5734 static int bpf_unpriv_handler(struct ctl_table *table, int write, 5735 void *buffer, size_t *lenp, loff_t *ppos) 5736 { 5737 int ret, unpriv_enable = *(int *)table->data; 5738 bool locked_state = unpriv_enable == 1; 5739 struct ctl_table tmp = *table; 5740 5741 if (write && !capable(CAP_SYS_ADMIN)) 5742 return -EPERM; 5743 5744 tmp.data = &unpriv_enable; 5745 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 5746 if (write && !ret) { 5747 if (locked_state && unpriv_enable != 1) 5748 return -EPERM; 5749 *(int *)table->data = unpriv_enable; 5750 } 5751 5752 if (write) 5753 unpriv_ebpf_notify(unpriv_enable); 5754 5755 return ret; 5756 } 5757 5758 static struct ctl_table bpf_syscall_table[] = { 5759 { 5760 .procname = "unprivileged_bpf_disabled", 5761 .data = &sysctl_unprivileged_bpf_disabled, 5762 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 5763 .mode = 0644, 5764 .proc_handler = bpf_unpriv_handler, 5765 .extra1 = SYSCTL_ZERO, 5766 .extra2 = SYSCTL_TWO, 5767 }, 5768 { 5769 .procname = "bpf_stats_enabled", 5770 .data = &bpf_stats_enabled_key.key, 5771 .mode = 0644, 5772 .proc_handler = bpf_stats_handler, 5773 }, 5774 { } 5775 }; 5776 5777 static int __init bpf_syscall_sysctl_init(void) 5778 { 5779 register_sysctl_init("kernel", bpf_syscall_table); 5780 return 0; 5781 } 5782 late_initcall(bpf_syscall_sysctl_init); 5783 #endif /* CONFIG_SYSCTL */ 5784