1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 */ 4 #include <crypto/sha2.h> 5 #include <linux/bpf.h> 6 #include <linux/bpf-cgroup.h> 7 #include <linux/bpf_trace.h> 8 #include <linux/bpf_lirc.h> 9 #include <linux/bpf_verifier.h> 10 #include <linux/bsearch.h> 11 #include <linux/btf.h> 12 #include <linux/hex.h> 13 #include <linux/syscalls.h> 14 #include <linux/slab.h> 15 #include <linux/sched/signal.h> 16 #include <linux/vmalloc.h> 17 #include <linux/mmzone.h> 18 #include <linux/anon_inodes.h> 19 #include <linux/fdtable.h> 20 #include <linux/file.h> 21 #include <linux/fs.h> 22 #include <linux/license.h> 23 #include <linux/filter.h> 24 #include <linux/kernel.h> 25 #include <linux/idr.h> 26 #include <linux/cred.h> 27 #include <linux/timekeeping.h> 28 #include <linux/ctype.h> 29 #include <linux/nospec.h> 30 #include <linux/audit.h> 31 #include <uapi/linux/btf.h> 32 #include <linux/pgtable.h> 33 #include <linux/bpf_lsm.h> 34 #include <linux/poll.h> 35 #include <linux/sort.h> 36 #include <linux/bpf-netns.h> 37 #include <linux/rcupdate_trace.h> 38 #include <linux/memcontrol.h> 39 #include <linux/trace_events.h> 40 #include <linux/tracepoint.h> 41 #include <linux/overflow.h> 42 #include <linux/cookie.h> 43 #include <linux/verification.h> 44 45 #include <net/netfilter/nf_bpf_link.h> 46 #include <net/netkit.h> 47 #include <net/tcx.h> 48 49 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ 50 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ 51 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 52 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) 53 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) 54 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ 55 IS_FD_HASH(map)) 56 57 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) 58 59 DEFINE_PER_CPU(int, bpf_prog_active); 60 DEFINE_COOKIE(bpf_map_cookie); 61 static DEFINE_IDR(prog_idr); 62 static DEFINE_SPINLOCK(prog_idr_lock); 63 static DEFINE_IDR(map_idr); 64 static DEFINE_SPINLOCK(map_idr_lock); 65 static DEFINE_IDR(link_idr); 66 static DEFINE_SPINLOCK(link_idr_lock); 67 68 int sysctl_unprivileged_bpf_disabled __read_mostly = 69 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; 70 71 static const struct bpf_map_ops * const bpf_map_types[] = { 72 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 73 #define BPF_MAP_TYPE(_id, _ops) \ 74 [_id] = &_ops, 75 #define BPF_LINK_TYPE(_id, _name) 76 #include <linux/bpf_types.h> 77 #undef BPF_PROG_TYPE 78 #undef BPF_MAP_TYPE 79 #undef BPF_LINK_TYPE 80 }; 81 82 /* 83 * If we're handed a bigger struct than we know of, ensure all the unknown bits 84 * are 0 - i.e. new user-space does not rely on any kernel feature extensions 85 * we don't know about yet. 86 * 87 * There is a ToCToU between this function call and the following 88 * copy_from_user() call. However, this is not a concern since this function is 89 * meant to be a future-proofing of bits. 90 */ 91 int bpf_check_uarg_tail_zero(bpfptr_t uaddr, 92 size_t expected_size, 93 size_t actual_size) 94 { 95 int res; 96 97 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ 98 return -E2BIG; 99 100 if (actual_size <= expected_size) 101 return 0; 102 103 if (uaddr.is_kernel) 104 res = memchr_inv(uaddr.kernel + expected_size, 0, 105 actual_size - expected_size) == NULL; 106 else 107 res = check_zeroed_user(uaddr.user + expected_size, 108 actual_size - expected_size); 109 if (res < 0) 110 return res; 111 return res ? 0 : -E2BIG; 112 } 113 114 const struct bpf_map_ops bpf_map_offload_ops = { 115 .map_meta_equal = bpf_map_meta_equal, 116 .map_alloc = bpf_map_offload_map_alloc, 117 .map_free = bpf_map_offload_map_free, 118 .map_check_btf = map_check_no_btf, 119 .map_mem_usage = bpf_map_offload_map_mem_usage, 120 }; 121 122 static void bpf_map_write_active_inc(struct bpf_map *map) 123 { 124 atomic64_inc(&map->writecnt); 125 } 126 127 static void bpf_map_write_active_dec(struct bpf_map *map) 128 { 129 atomic64_dec(&map->writecnt); 130 } 131 132 bool bpf_map_write_active(const struct bpf_map *map) 133 { 134 return atomic64_read(&map->writecnt) != 0; 135 } 136 137 static u32 bpf_map_value_size(const struct bpf_map *map, u64 flags) 138 { 139 if (flags & (BPF_F_CPU | BPF_F_ALL_CPUS)) 140 return map->value_size; 141 else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 142 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 143 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || 144 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) 145 return round_up(map->value_size, 8) * num_possible_cpus(); 146 else if (IS_FD_MAP(map)) 147 return sizeof(u32); 148 else 149 return map->value_size; 150 } 151 152 static void maybe_wait_bpf_programs(struct bpf_map *map) 153 { 154 /* Wait for any running non-sleepable BPF programs to complete so that 155 * userspace, when we return to it, knows that all non-sleepable 156 * programs that could be running use the new map value. For sleepable 157 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait 158 * for the completions of these programs, but considering the waiting 159 * time can be very long and userspace may think it will hang forever, 160 * so don't handle sleepable BPF programs now. 161 */ 162 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || 163 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 164 synchronize_rcu_expedited(); 165 } 166 167 static void unpin_uptr_kaddr(void *kaddr) 168 { 169 if (kaddr) 170 unpin_user_page(virt_to_page(kaddr)); 171 } 172 173 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj) 174 { 175 const struct btf_field *field; 176 void **uptr_addr; 177 int i; 178 179 for (i = 0, field = rec->fields; i < cnt; i++, field++) { 180 if (field->type != BPF_UPTR) 181 continue; 182 183 uptr_addr = obj + field->offset; 184 unpin_uptr_kaddr(*uptr_addr); 185 } 186 } 187 188 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj) 189 { 190 if (!btf_record_has_field(rec, BPF_UPTR)) 191 return; 192 193 __bpf_obj_unpin_uptrs(rec, rec->cnt, obj); 194 } 195 196 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj) 197 { 198 const struct btf_field *field; 199 const struct btf_type *t; 200 unsigned long start, end; 201 struct page *page; 202 void **uptr_addr; 203 int i, err; 204 205 if (!btf_record_has_field(rec, BPF_UPTR)) 206 return 0; 207 208 for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) { 209 if (field->type != BPF_UPTR) 210 continue; 211 212 uptr_addr = obj + field->offset; 213 start = *(unsigned long *)uptr_addr; 214 if (!start) 215 continue; 216 217 t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id); 218 /* t->size was checked for zero before */ 219 if (check_add_overflow(start, t->size - 1, &end)) { 220 err = -EFAULT; 221 goto unpin_all; 222 } 223 224 /* The uptr's struct cannot span across two pages */ 225 if ((start & PAGE_MASK) != (end & PAGE_MASK)) { 226 err = -EOPNOTSUPP; 227 goto unpin_all; 228 } 229 230 err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page); 231 if (err != 1) 232 goto unpin_all; 233 234 if (PageHighMem(page)) { 235 err = -EOPNOTSUPP; 236 unpin_user_page(page); 237 goto unpin_all; 238 } 239 240 *uptr_addr = page_address(page) + offset_in_page(start); 241 } 242 243 return 0; 244 245 unpin_all: 246 __bpf_obj_unpin_uptrs(rec, i, obj); 247 return err; 248 } 249 250 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, 251 void *key, void *value, __u64 flags) 252 { 253 int err; 254 255 /* Need to create a kthread, thus must support schedule */ 256 if (bpf_map_is_offloaded(map)) { 257 return bpf_map_offload_update_elem(map, key, value, flags); 258 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || 259 map->map_type == BPF_MAP_TYPE_ARENA || 260 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 261 return map->ops->map_update_elem(map, key, value, flags); 262 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || 263 map->map_type == BPF_MAP_TYPE_SOCKMAP) { 264 return sock_map_update_elem_sys(map, key, value, flags); 265 } else if (IS_FD_PROG_ARRAY(map)) { 266 return bpf_fd_array_map_update_elem(map, map_file, key, value, 267 flags); 268 } 269 270 bpf_disable_instrumentation(); 271 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 272 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 273 err = bpf_percpu_hash_update(map, key, value, flags); 274 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 275 err = bpf_percpu_array_update(map, key, value, flags); 276 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 277 err = bpf_percpu_cgroup_storage_update(map, key, value, 278 flags); 279 } else if (IS_FD_ARRAY(map)) { 280 err = bpf_fd_array_map_update_elem(map, map_file, key, value, 281 flags); 282 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 283 err = bpf_fd_htab_map_update_elem(map, map_file, key, value, 284 flags); 285 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 286 /* rcu_read_lock() is not needed */ 287 err = bpf_fd_reuseport_array_update_elem(map, key, value, 288 flags); 289 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 290 map->map_type == BPF_MAP_TYPE_STACK || 291 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 292 err = map->ops->map_push_elem(map, value, flags); 293 } else { 294 err = bpf_obj_pin_uptrs(map->record, value); 295 if (!err) { 296 rcu_read_lock(); 297 err = map->ops->map_update_elem(map, key, value, flags); 298 rcu_read_unlock(); 299 if (err) 300 bpf_obj_unpin_uptrs(map->record, value); 301 } 302 } 303 bpf_enable_instrumentation(); 304 305 return err; 306 } 307 308 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, 309 __u64 flags) 310 { 311 void *ptr; 312 int err; 313 314 if (bpf_map_is_offloaded(map)) 315 return bpf_map_offload_lookup_elem(map, key, value); 316 317 bpf_disable_instrumentation(); 318 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 319 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 320 err = bpf_percpu_hash_copy(map, key, value, flags); 321 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 322 err = bpf_percpu_array_copy(map, key, value, flags); 323 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 324 err = bpf_percpu_cgroup_storage_copy(map, key, value, flags); 325 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 326 err = bpf_stackmap_extract(map, key, value, false); 327 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { 328 err = bpf_fd_array_map_lookup_elem(map, key, value); 329 } else if (IS_FD_HASH(map)) { 330 err = bpf_fd_htab_map_lookup_elem(map, key, value); 331 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 332 err = bpf_fd_reuseport_array_lookup_elem(map, key, value); 333 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 334 map->map_type == BPF_MAP_TYPE_STACK || 335 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 336 err = map->ops->map_peek_elem(map, value); 337 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 338 /* struct_ops map requires directly updating "value" */ 339 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value); 340 } else { 341 rcu_read_lock(); 342 if (map->ops->map_lookup_elem_sys_only) 343 ptr = map->ops->map_lookup_elem_sys_only(map, key); 344 else 345 ptr = map->ops->map_lookup_elem(map, key); 346 if (IS_ERR(ptr)) { 347 err = PTR_ERR(ptr); 348 } else if (!ptr) { 349 err = -ENOENT; 350 } else { 351 err = 0; 352 if (flags & BPF_F_LOCK) 353 /* lock 'ptr' and copy everything but lock */ 354 copy_map_value_locked(map, value, ptr, true); 355 else 356 copy_map_value(map, value, ptr); 357 /* mask lock and timer, since value wasn't zero inited */ 358 check_and_init_map_value(map, value); 359 } 360 rcu_read_unlock(); 361 } 362 363 bpf_enable_instrumentation(); 364 365 return err; 366 } 367 368 /* Please, do not use this function outside from the map creation path 369 * (e.g. in map update path) without taking care of setting the active 370 * memory cgroup (see at bpf_map_kmalloc_node() for example). 371 */ 372 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) 373 { 374 /* We really just want to fail instead of triggering OOM killer 375 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, 376 * which is used for lower order allocation requests. 377 * 378 * It has been observed that higher order allocation requests done by 379 * vmalloc with __GFP_NORETRY being set might fail due to not trying 380 * to reclaim memory from the page cache, thus we set 381 * __GFP_RETRY_MAYFAIL to avoid such situations. 382 */ 383 384 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO); 385 unsigned int flags = 0; 386 unsigned long align = 1; 387 void *area; 388 389 if (size >= SIZE_MAX) 390 return NULL; 391 392 /* kmalloc()'ed memory can't be mmap()'ed */ 393 if (mmapable) { 394 BUG_ON(!PAGE_ALIGNED(size)); 395 align = SHMLBA; 396 flags = VM_USERMAP; 397 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { 398 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, 399 numa_node); 400 if (area != NULL) 401 return area; 402 } 403 404 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 405 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, 406 flags, numa_node, __builtin_return_address(0)); 407 } 408 409 void *bpf_map_area_alloc(u64 size, int numa_node) 410 { 411 return __bpf_map_area_alloc(size, numa_node, false); 412 } 413 414 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) 415 { 416 return __bpf_map_area_alloc(size, numa_node, true); 417 } 418 419 void bpf_map_area_free(void *area) 420 { 421 kvfree(area); 422 } 423 424 static u32 bpf_map_flags_retain_permanent(u32 flags) 425 { 426 /* Some map creation flags are not tied to the map object but 427 * rather to the map fd instead, so they have no meaning upon 428 * map object inspection since multiple file descriptors with 429 * different (access) properties can exist here. Thus, given 430 * this has zero meaning for the map itself, lets clear these 431 * from here. 432 */ 433 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); 434 } 435 436 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) 437 { 438 map->map_type = attr->map_type; 439 map->key_size = attr->key_size; 440 map->value_size = attr->value_size; 441 map->max_entries = attr->max_entries; 442 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); 443 map->numa_node = bpf_map_attr_numa_node(attr); 444 map->map_extra = attr->map_extra; 445 } 446 447 static int bpf_map_alloc_id(struct bpf_map *map) 448 { 449 int id; 450 451 idr_preload(GFP_KERNEL); 452 spin_lock_bh(&map_idr_lock); 453 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); 454 if (id > 0) 455 map->id = id; 456 spin_unlock_bh(&map_idr_lock); 457 idr_preload_end(); 458 459 if (WARN_ON_ONCE(!id)) 460 return -ENOSPC; 461 462 return id > 0 ? 0 : id; 463 } 464 465 void bpf_map_free_id(struct bpf_map *map) 466 { 467 unsigned long flags; 468 469 /* Offloaded maps are removed from the IDR store when their device 470 * disappears - even if someone holds an fd to them they are unusable, 471 * the memory is gone, all ops will fail; they are simply waiting for 472 * refcnt to drop to be freed. 473 */ 474 if (!map->id) 475 return; 476 477 spin_lock_irqsave(&map_idr_lock, flags); 478 479 idr_remove(&map_idr, map->id); 480 map->id = 0; 481 482 spin_unlock_irqrestore(&map_idr_lock, flags); 483 } 484 485 #ifdef CONFIG_MEMCG 486 static void bpf_map_save_memcg(struct bpf_map *map) 487 { 488 /* Currently if a map is created by a process belonging to the root 489 * memory cgroup, get_obj_cgroup_from_current() will return NULL. 490 * So we have to check map->objcg for being NULL each time it's 491 * being used. 492 */ 493 if (memcg_bpf_enabled()) 494 map->objcg = get_obj_cgroup_from_current(); 495 } 496 497 static void bpf_map_release_memcg(struct bpf_map *map) 498 { 499 if (map->objcg) 500 obj_cgroup_put(map->objcg); 501 } 502 503 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) 504 { 505 if (map->objcg) 506 return get_mem_cgroup_from_objcg(map->objcg); 507 508 return root_mem_cgroup; 509 } 510 511 void bpf_map_memcg_enter(const struct bpf_map *map, struct mem_cgroup **old_memcg, 512 struct mem_cgroup **new_memcg) 513 { 514 *new_memcg = bpf_map_get_memcg(map); 515 *old_memcg = set_active_memcg(*new_memcg); 516 } 517 518 void bpf_map_memcg_exit(struct mem_cgroup *old_memcg, 519 struct mem_cgroup *new_memcg) 520 { 521 set_active_memcg(old_memcg); 522 mem_cgroup_put(new_memcg); 523 } 524 525 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, 526 int node) 527 { 528 struct mem_cgroup *memcg, *old_memcg; 529 void *ptr; 530 531 bpf_map_memcg_enter(map, &old_memcg, &memcg); 532 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); 533 bpf_map_memcg_exit(old_memcg, memcg); 534 535 return ptr; 536 } 537 538 void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags, 539 int node) 540 { 541 struct mem_cgroup *memcg, *old_memcg; 542 void *ptr; 543 544 bpf_map_memcg_enter(map, &old_memcg, &memcg); 545 ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node); 546 bpf_map_memcg_exit(old_memcg, memcg); 547 548 return ptr; 549 } 550 551 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) 552 { 553 struct mem_cgroup *memcg, *old_memcg; 554 void *ptr; 555 556 bpf_map_memcg_enter(map, &old_memcg, &memcg); 557 ptr = kzalloc(size, flags | __GFP_ACCOUNT); 558 bpf_map_memcg_exit(old_memcg, memcg); 559 560 return ptr; 561 } 562 563 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, 564 gfp_t flags) 565 { 566 struct mem_cgroup *memcg, *old_memcg; 567 void *ptr; 568 569 bpf_map_memcg_enter(map, &old_memcg, &memcg); 570 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); 571 bpf_map_memcg_exit(old_memcg, memcg); 572 573 return ptr; 574 } 575 576 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, 577 size_t align, gfp_t flags) 578 { 579 struct mem_cgroup *memcg, *old_memcg; 580 void __percpu *ptr; 581 582 bpf_map_memcg_enter(map, &old_memcg, &memcg); 583 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); 584 bpf_map_memcg_exit(old_memcg, memcg); 585 586 return ptr; 587 } 588 589 #else 590 static void bpf_map_save_memcg(struct bpf_map *map) 591 { 592 } 593 594 static void bpf_map_release_memcg(struct bpf_map *map) 595 { 596 } 597 #endif 598 599 static bool can_alloc_pages(void) 600 { 601 return preempt_count() == 0 && !irqs_disabled() && 602 !IS_ENABLED(CONFIG_PREEMPT_RT); 603 } 604 605 static struct page *__bpf_alloc_page(int nid) 606 { 607 if (!can_alloc_pages()) 608 return alloc_pages_nolock(__GFP_ACCOUNT, nid, 0); 609 610 return alloc_pages_node(nid, 611 GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT 612 | __GFP_NOWARN, 613 0); 614 } 615 616 int bpf_map_alloc_pages(const struct bpf_map *map, int nid, 617 unsigned long nr_pages, struct page **pages) 618 { 619 unsigned long i, j; 620 struct page *pg; 621 int ret = 0; 622 623 for (i = 0; i < nr_pages; i++) { 624 pg = __bpf_alloc_page(nid); 625 626 if (pg) { 627 pages[i] = pg; 628 continue; 629 } 630 for (j = 0; j < i; j++) 631 free_pages_nolock(pages[j], 0); 632 ret = -ENOMEM; 633 break; 634 } 635 636 return ret; 637 } 638 639 640 static int btf_field_cmp(const void *a, const void *b) 641 { 642 const struct btf_field *f1 = a, *f2 = b; 643 644 if (f1->offset < f2->offset) 645 return -1; 646 else if (f1->offset > f2->offset) 647 return 1; 648 return 0; 649 } 650 651 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 652 u32 field_mask) 653 { 654 struct btf_field *field; 655 656 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 657 return NULL; 658 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 659 if (!field || !(field->type & field_mask)) 660 return NULL; 661 return field; 662 } 663 664 void btf_record_free(struct btf_record *rec) 665 { 666 int i; 667 668 if (IS_ERR_OR_NULL(rec)) 669 return; 670 for (i = 0; i < rec->cnt; i++) { 671 switch (rec->fields[i].type) { 672 case BPF_KPTR_UNREF: 673 case BPF_KPTR_REF: 674 case BPF_KPTR_PERCPU: 675 case BPF_UPTR: 676 if (rec->fields[i].kptr.module) 677 module_put(rec->fields[i].kptr.module); 678 if (btf_is_kernel(rec->fields[i].kptr.btf)) 679 btf_put(rec->fields[i].kptr.btf); 680 break; 681 case BPF_LIST_HEAD: 682 case BPF_LIST_NODE: 683 case BPF_RB_ROOT: 684 case BPF_RB_NODE: 685 case BPF_SPIN_LOCK: 686 case BPF_RES_SPIN_LOCK: 687 case BPF_TIMER: 688 case BPF_REFCOUNT: 689 case BPF_WORKQUEUE: 690 case BPF_TASK_WORK: 691 /* Nothing to release */ 692 break; 693 default: 694 WARN_ON_ONCE(1); 695 continue; 696 } 697 } 698 kfree(rec); 699 } 700 701 void bpf_map_free_record(struct bpf_map *map) 702 { 703 btf_record_free(map->record); 704 map->record = NULL; 705 } 706 707 struct btf_record *btf_record_dup(const struct btf_record *rec) 708 { 709 const struct btf_field *fields; 710 struct btf_record *new_rec; 711 int ret, size, i; 712 713 if (IS_ERR_OR_NULL(rec)) 714 return NULL; 715 size = struct_size(rec, fields, rec->cnt); 716 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 717 if (!new_rec) 718 return ERR_PTR(-ENOMEM); 719 /* Do a deep copy of the btf_record */ 720 fields = rec->fields; 721 new_rec->cnt = 0; 722 for (i = 0; i < rec->cnt; i++) { 723 switch (fields[i].type) { 724 case BPF_KPTR_UNREF: 725 case BPF_KPTR_REF: 726 case BPF_KPTR_PERCPU: 727 case BPF_UPTR: 728 if (btf_is_kernel(fields[i].kptr.btf)) 729 btf_get(fields[i].kptr.btf); 730 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 731 ret = -ENXIO; 732 goto free; 733 } 734 break; 735 case BPF_LIST_HEAD: 736 case BPF_LIST_NODE: 737 case BPF_RB_ROOT: 738 case BPF_RB_NODE: 739 case BPF_SPIN_LOCK: 740 case BPF_RES_SPIN_LOCK: 741 case BPF_TIMER: 742 case BPF_REFCOUNT: 743 case BPF_WORKQUEUE: 744 case BPF_TASK_WORK: 745 /* Nothing to acquire */ 746 break; 747 default: 748 ret = -EFAULT; 749 WARN_ON_ONCE(1); 750 goto free; 751 } 752 new_rec->cnt++; 753 } 754 return new_rec; 755 free: 756 btf_record_free(new_rec); 757 return ERR_PTR(ret); 758 } 759 760 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 761 { 762 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 763 int size; 764 765 if (!a_has_fields && !b_has_fields) 766 return true; 767 if (a_has_fields != b_has_fields) 768 return false; 769 if (rec_a->cnt != rec_b->cnt) 770 return false; 771 size = struct_size(rec_a, fields, rec_a->cnt); 772 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 773 * members are zeroed out. So memcmp is safe to do without worrying 774 * about padding/unused fields. 775 * 776 * While spin_lock, timer, and kptr have no relation to map BTF, 777 * list_head metadata is specific to map BTF, the btf and value_rec 778 * members in particular. btf is the map BTF, while value_rec points to 779 * btf_record in that map BTF. 780 * 781 * So while by default, we don't rely on the map BTF (which the records 782 * were parsed from) matching for both records, which is not backwards 783 * compatible, in case list_head is part of it, we implicitly rely on 784 * that by way of depending on memcmp succeeding for it. 785 */ 786 return !memcmp(rec_a, rec_b, size); 787 } 788 789 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 790 { 791 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 792 return; 793 bpf_timer_cancel_and_free(obj + rec->timer_off); 794 } 795 796 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj) 797 { 798 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE))) 799 return; 800 bpf_wq_cancel_and_free(obj + rec->wq_off); 801 } 802 803 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj) 804 { 805 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK))) 806 return; 807 bpf_task_work_cancel_and_free(obj + rec->task_work_off); 808 } 809 810 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 811 { 812 const struct btf_field *fields; 813 int i; 814 815 if (IS_ERR_OR_NULL(rec)) 816 return; 817 fields = rec->fields; 818 for (i = 0; i < rec->cnt; i++) { 819 struct btf_struct_meta *pointee_struct_meta; 820 const struct btf_field *field = &fields[i]; 821 void *field_ptr = obj + field->offset; 822 void *xchgd_field; 823 824 switch (fields[i].type) { 825 case BPF_SPIN_LOCK: 826 case BPF_RES_SPIN_LOCK: 827 break; 828 case BPF_TIMER: 829 bpf_timer_cancel_and_free(field_ptr); 830 break; 831 case BPF_WORKQUEUE: 832 bpf_wq_cancel_and_free(field_ptr); 833 break; 834 case BPF_TASK_WORK: 835 bpf_task_work_cancel_and_free(field_ptr); 836 break; 837 case BPF_KPTR_UNREF: 838 WRITE_ONCE(*(u64 *)field_ptr, 0); 839 break; 840 case BPF_KPTR_REF: 841 case BPF_KPTR_PERCPU: 842 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); 843 if (!xchgd_field) 844 break; 845 846 if (!btf_is_kernel(field->kptr.btf)) { 847 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, 848 field->kptr.btf_id); 849 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? 850 pointee_struct_meta->record : NULL, 851 fields[i].type == BPF_KPTR_PERCPU); 852 } else { 853 field->kptr.dtor(xchgd_field); 854 } 855 break; 856 case BPF_UPTR: 857 /* The caller ensured that no one is using the uptr */ 858 unpin_uptr_kaddr(*(void **)field_ptr); 859 break; 860 case BPF_LIST_HEAD: 861 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 862 continue; 863 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 864 break; 865 case BPF_RB_ROOT: 866 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 867 continue; 868 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); 869 break; 870 case BPF_LIST_NODE: 871 case BPF_RB_NODE: 872 case BPF_REFCOUNT: 873 break; 874 default: 875 WARN_ON_ONCE(1); 876 continue; 877 } 878 } 879 } 880 881 static void bpf_map_free(struct bpf_map *map) 882 { 883 struct btf_record *rec = map->record; 884 struct btf *btf = map->btf; 885 886 /* implementation dependent freeing. Disabling migration to simplify 887 * the free of values or special fields allocated from bpf memory 888 * allocator. 889 */ 890 kfree(map->excl_prog_sha); 891 migrate_disable(); 892 map->ops->map_free(map); 893 migrate_enable(); 894 895 /* Delay freeing of btf_record for maps, as map_free 896 * callback usually needs access to them. It is better to do it here 897 * than require each callback to do the free itself manually. 898 * 899 * Note that the btf_record stashed in map->inner_map_meta->record was 900 * already freed using the map_free callback for map in map case which 901 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 902 * template bpf_map struct used during verification. 903 */ 904 btf_record_free(rec); 905 /* Delay freeing of btf for maps, as map_free callback may need 906 * struct_meta info which will be freed with btf_put(). 907 */ 908 btf_put(btf); 909 } 910 911 /* called from workqueue */ 912 static void bpf_map_free_deferred(struct work_struct *work) 913 { 914 struct bpf_map *map = container_of(work, struct bpf_map, work); 915 916 security_bpf_map_free(map); 917 bpf_map_release_memcg(map); 918 bpf_map_owner_free(map); 919 bpf_map_free(map); 920 } 921 922 static void bpf_map_put_uref(struct bpf_map *map) 923 { 924 if (atomic64_dec_and_test(&map->usercnt)) { 925 if (map->ops->map_release_uref) 926 map->ops->map_release_uref(map); 927 } 928 } 929 930 static void bpf_map_free_in_work(struct bpf_map *map) 931 { 932 INIT_WORK(&map->work, bpf_map_free_deferred); 933 /* Avoid spawning kworkers, since they all might contend 934 * for the same mutex like slab_mutex. 935 */ 936 queue_work(system_dfl_wq, &map->work); 937 } 938 939 static void bpf_map_free_rcu_gp(struct rcu_head *rcu) 940 { 941 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); 942 } 943 944 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu) 945 { 946 if (rcu_trace_implies_rcu_gp()) 947 bpf_map_free_rcu_gp(rcu); 948 else 949 call_rcu(rcu, bpf_map_free_rcu_gp); 950 } 951 952 /* decrement map refcnt and schedule it for freeing via workqueue 953 * (underlying map implementation ops->map_free() might sleep) 954 */ 955 void bpf_map_put(struct bpf_map *map) 956 { 957 if (atomic64_dec_and_test(&map->refcnt)) { 958 /* bpf_map_free_id() must be called first */ 959 bpf_map_free_id(map); 960 961 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); 962 if (READ_ONCE(map->free_after_mult_rcu_gp)) 963 call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp); 964 else if (READ_ONCE(map->free_after_rcu_gp)) 965 call_rcu(&map->rcu, bpf_map_free_rcu_gp); 966 else 967 bpf_map_free_in_work(map); 968 } 969 } 970 EXPORT_SYMBOL_GPL(bpf_map_put); 971 972 void bpf_map_put_with_uref(struct bpf_map *map) 973 { 974 bpf_map_put_uref(map); 975 bpf_map_put(map); 976 } 977 978 static int bpf_map_release(struct inode *inode, struct file *filp) 979 { 980 struct bpf_map *map = filp->private_data; 981 982 if (map->ops->map_release) 983 map->ops->map_release(map, filp); 984 985 bpf_map_put_with_uref(map); 986 return 0; 987 } 988 989 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 990 { 991 fmode_t mode = fd_file(f)->f_mode; 992 993 /* Our file permissions may have been overridden by global 994 * map permissions facing syscall side. 995 */ 996 if (READ_ONCE(map->frozen)) 997 mode &= ~FMODE_CAN_WRITE; 998 return mode; 999 } 1000 1001 #ifdef CONFIG_PROC_FS 1002 /* Show the memory usage of a bpf map */ 1003 static u64 bpf_map_memory_usage(const struct bpf_map *map) 1004 { 1005 return map->ops->map_mem_usage(map); 1006 } 1007 1008 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 1009 { 1010 struct bpf_map *map = filp->private_data; 1011 u32 type = 0, jited = 0; 1012 1013 spin_lock(&map->owner_lock); 1014 if (map->owner) { 1015 type = map->owner->type; 1016 jited = map->owner->jited; 1017 } 1018 spin_unlock(&map->owner_lock); 1019 1020 seq_printf(m, 1021 "map_type:\t%u\n" 1022 "key_size:\t%u\n" 1023 "value_size:\t%u\n" 1024 "max_entries:\t%u\n" 1025 "map_flags:\t%#x\n" 1026 "map_extra:\t%#llx\n" 1027 "memlock:\t%llu\n" 1028 "map_id:\t%u\n" 1029 "frozen:\t%u\n", 1030 map->map_type, 1031 map->key_size, 1032 map->value_size, 1033 map->max_entries, 1034 map->map_flags, 1035 (unsigned long long)map->map_extra, 1036 bpf_map_memory_usage(map), 1037 map->id, 1038 READ_ONCE(map->frozen)); 1039 if (type) { 1040 seq_printf(m, "owner_prog_type:\t%u\n", type); 1041 seq_printf(m, "owner_jited:\t%u\n", jited); 1042 } 1043 } 1044 #endif 1045 1046 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 1047 loff_t *ppos) 1048 { 1049 /* We need this handler such that alloc_file() enables 1050 * f_mode with FMODE_CAN_READ. 1051 */ 1052 return -EINVAL; 1053 } 1054 1055 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 1056 size_t siz, loff_t *ppos) 1057 { 1058 /* We need this handler such that alloc_file() enables 1059 * f_mode with FMODE_CAN_WRITE. 1060 */ 1061 return -EINVAL; 1062 } 1063 1064 /* called for any extra memory-mapped regions (except initial) */ 1065 static void bpf_map_mmap_open(struct vm_area_struct *vma) 1066 { 1067 struct bpf_map *map = vma->vm_file->private_data; 1068 1069 if (vma->vm_flags & VM_MAYWRITE) 1070 bpf_map_write_active_inc(map); 1071 } 1072 1073 /* called for all unmapped memory region (including initial) */ 1074 static void bpf_map_mmap_close(struct vm_area_struct *vma) 1075 { 1076 struct bpf_map *map = vma->vm_file->private_data; 1077 1078 if (vma->vm_flags & VM_MAYWRITE) 1079 bpf_map_write_active_dec(map); 1080 } 1081 1082 static const struct vm_operations_struct bpf_map_default_vmops = { 1083 .open = bpf_map_mmap_open, 1084 .close = bpf_map_mmap_close, 1085 }; 1086 1087 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 1088 { 1089 struct bpf_map *map = filp->private_data; 1090 int err = 0; 1091 1092 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 1093 return -ENOTSUPP; 1094 1095 if (!(vma->vm_flags & VM_SHARED)) 1096 return -EINVAL; 1097 1098 mutex_lock(&map->freeze_mutex); 1099 1100 if (vma->vm_flags & VM_WRITE) { 1101 if (map->frozen) { 1102 err = -EPERM; 1103 goto out; 1104 } 1105 /* map is meant to be read-only, so do not allow mapping as 1106 * writable, because it's possible to leak a writable page 1107 * reference and allows user-space to still modify it after 1108 * freezing, while verifier will assume contents do not change 1109 */ 1110 if (map->map_flags & BPF_F_RDONLY_PROG) { 1111 err = -EACCES; 1112 goto out; 1113 } 1114 bpf_map_write_active_inc(map); 1115 } 1116 out: 1117 mutex_unlock(&map->freeze_mutex); 1118 if (err) 1119 return err; 1120 1121 /* set default open/close callbacks */ 1122 vma->vm_ops = &bpf_map_default_vmops; 1123 vma->vm_private_data = map; 1124 vm_flags_clear(vma, VM_MAYEXEC); 1125 /* If mapping is read-only, then disallow potentially re-mapping with 1126 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing 1127 * means that as far as BPF map's memory-mapped VMAs are concerned, 1128 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set, 1129 * both should be set, so we can forget about VM_MAYWRITE and always 1130 * check just VM_WRITE 1131 */ 1132 if (!(vma->vm_flags & VM_WRITE)) 1133 vm_flags_clear(vma, VM_MAYWRITE); 1134 1135 err = map->ops->map_mmap(map, vma); 1136 if (err) { 1137 if (vma->vm_flags & VM_WRITE) 1138 bpf_map_write_active_dec(map); 1139 } 1140 1141 return err; 1142 } 1143 1144 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 1145 { 1146 struct bpf_map *map = filp->private_data; 1147 1148 if (map->ops->map_poll) 1149 return map->ops->map_poll(map, filp, pts); 1150 1151 return EPOLLERR; 1152 } 1153 1154 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr, 1155 unsigned long len, unsigned long pgoff, 1156 unsigned long flags) 1157 { 1158 struct bpf_map *map = filp->private_data; 1159 1160 if (map->ops->map_get_unmapped_area) 1161 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); 1162 #ifdef CONFIG_MMU 1163 return mm_get_unmapped_area(filp, addr, len, pgoff, flags); 1164 #else 1165 return addr; 1166 #endif 1167 } 1168 1169 const struct file_operations bpf_map_fops = { 1170 #ifdef CONFIG_PROC_FS 1171 .show_fdinfo = bpf_map_show_fdinfo, 1172 #endif 1173 .release = bpf_map_release, 1174 .read = bpf_dummy_read, 1175 .write = bpf_dummy_write, 1176 .mmap = bpf_map_mmap, 1177 .poll = bpf_map_poll, 1178 .get_unmapped_area = bpf_get_unmapped_area, 1179 }; 1180 1181 int bpf_map_new_fd(struct bpf_map *map, int flags) 1182 { 1183 int ret; 1184 1185 ret = security_bpf_map(map, OPEN_FMODE(flags)); 1186 if (ret < 0) 1187 return ret; 1188 1189 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 1190 flags | O_CLOEXEC); 1191 } 1192 1193 int bpf_get_file_flag(int flags) 1194 { 1195 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 1196 return -EINVAL; 1197 if (flags & BPF_F_RDONLY) 1198 return O_RDONLY; 1199 if (flags & BPF_F_WRONLY) 1200 return O_WRONLY; 1201 return O_RDWR; 1202 } 1203 1204 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 1205 #define CHECK_ATTR(CMD) \ 1206 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 1207 sizeof(attr->CMD##_LAST_FIELD), 0, \ 1208 sizeof(*attr) - \ 1209 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 1210 sizeof(attr->CMD##_LAST_FIELD)) != NULL 1211 1212 /* dst and src must have at least "size" number of bytes. 1213 * Return strlen on success and < 0 on error. 1214 */ 1215 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 1216 { 1217 const char *end = src + size; 1218 const char *orig_src = src; 1219 1220 memset(dst, 0, size); 1221 /* Copy all isalnum(), '_' and '.' chars. */ 1222 while (src < end && *src) { 1223 if (!isalnum(*src) && 1224 *src != '_' && *src != '.') 1225 return -EINVAL; 1226 *dst++ = *src++; 1227 } 1228 1229 /* No '\0' found in "size" number of bytes */ 1230 if (src == end) 1231 return -EINVAL; 1232 1233 return src - orig_src; 1234 } 1235 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy); 1236 1237 int map_check_no_btf(const struct bpf_map *map, 1238 const struct btf *btf, 1239 const struct btf_type *key_type, 1240 const struct btf_type *value_type) 1241 { 1242 return -ENOTSUPP; 1243 } 1244 1245 static int map_check_btf(struct bpf_map *map, struct bpf_token *token, 1246 const struct btf *btf, u32 btf_key_id, u32 btf_value_id) 1247 { 1248 const struct btf_type *key_type, *value_type; 1249 u32 key_size, value_size; 1250 int ret = 0; 1251 1252 /* Some maps allow key to be unspecified. */ 1253 if (btf_key_id) { 1254 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 1255 if (!key_type || key_size != map->key_size) 1256 return -EINVAL; 1257 } else { 1258 key_type = btf_type_by_id(btf, 0); 1259 if (!map->ops->map_check_btf) 1260 return -EINVAL; 1261 } 1262 1263 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1264 if (!value_type || value_size != map->value_size) 1265 return -EINVAL; 1266 1267 map->record = btf_parse_fields(btf, value_type, 1268 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1269 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR | 1270 BPF_TASK_WORK, 1271 map->value_size); 1272 if (!IS_ERR_OR_NULL(map->record)) { 1273 int i; 1274 1275 if (!bpf_token_capable(token, CAP_BPF)) { 1276 ret = -EPERM; 1277 goto free_map_tab; 1278 } 1279 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1280 ret = -EACCES; 1281 goto free_map_tab; 1282 } 1283 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1284 switch (map->record->field_mask & (1 << i)) { 1285 case 0: 1286 continue; 1287 case BPF_SPIN_LOCK: 1288 case BPF_RES_SPIN_LOCK: 1289 if (map->map_type != BPF_MAP_TYPE_HASH && 1290 map->map_type != BPF_MAP_TYPE_ARRAY && 1291 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1292 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1293 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1294 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1295 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1296 ret = -EOPNOTSUPP; 1297 goto free_map_tab; 1298 } 1299 break; 1300 case BPF_TIMER: 1301 case BPF_WORKQUEUE: 1302 case BPF_TASK_WORK: 1303 if (map->map_type != BPF_MAP_TYPE_HASH && 1304 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1305 map->map_type != BPF_MAP_TYPE_ARRAY) { 1306 ret = -EOPNOTSUPP; 1307 goto free_map_tab; 1308 } 1309 break; 1310 case BPF_KPTR_UNREF: 1311 case BPF_KPTR_REF: 1312 case BPF_KPTR_PERCPU: 1313 case BPF_REFCOUNT: 1314 if (map->map_type != BPF_MAP_TYPE_HASH && 1315 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1316 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1317 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1318 map->map_type != BPF_MAP_TYPE_ARRAY && 1319 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1320 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1321 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1322 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1323 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1324 ret = -EOPNOTSUPP; 1325 goto free_map_tab; 1326 } 1327 break; 1328 case BPF_UPTR: 1329 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { 1330 ret = -EOPNOTSUPP; 1331 goto free_map_tab; 1332 } 1333 break; 1334 case BPF_LIST_HEAD: 1335 case BPF_RB_ROOT: 1336 if (map->map_type != BPF_MAP_TYPE_HASH && 1337 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1338 map->map_type != BPF_MAP_TYPE_ARRAY) { 1339 ret = -EOPNOTSUPP; 1340 goto free_map_tab; 1341 } 1342 break; 1343 default: 1344 /* Fail if map_type checks are missing for a field type */ 1345 ret = -EOPNOTSUPP; 1346 goto free_map_tab; 1347 } 1348 } 1349 } 1350 1351 ret = btf_check_and_fixup_fields(btf, map->record); 1352 if (ret < 0) 1353 goto free_map_tab; 1354 1355 if (map->ops->map_check_btf) { 1356 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1357 if (ret < 0) 1358 goto free_map_tab; 1359 } 1360 1361 return ret; 1362 free_map_tab: 1363 bpf_map_free_record(map); 1364 return ret; 1365 } 1366 1367 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size 1368 /* called via syscall */ 1369 static int map_create(union bpf_attr *attr, bpfptr_t uattr) 1370 { 1371 const struct bpf_map_ops *ops; 1372 struct bpf_token *token = NULL; 1373 int numa_node = bpf_map_attr_numa_node(attr); 1374 u32 map_type = attr->map_type; 1375 struct bpf_map *map; 1376 bool token_flag; 1377 int f_flags; 1378 int err; 1379 1380 err = CHECK_ATTR(BPF_MAP_CREATE); 1381 if (err) 1382 return -EINVAL; 1383 1384 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it 1385 * to avoid per-map type checks tripping on unknown flag 1386 */ 1387 token_flag = attr->map_flags & BPF_F_TOKEN_FD; 1388 attr->map_flags &= ~BPF_F_TOKEN_FD; 1389 1390 if (attr->btf_vmlinux_value_type_id) { 1391 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || 1392 attr->btf_key_type_id || attr->btf_value_type_id) 1393 return -EINVAL; 1394 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1395 return -EINVAL; 1396 } 1397 1398 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1399 attr->map_type != BPF_MAP_TYPE_ARENA && 1400 attr->map_extra != 0) 1401 return -EINVAL; 1402 1403 f_flags = bpf_get_file_flag(attr->map_flags); 1404 if (f_flags < 0) 1405 return f_flags; 1406 1407 if (numa_node != NUMA_NO_NODE && 1408 ((unsigned int)numa_node >= nr_node_ids || 1409 !node_online(numa_node))) 1410 return -EINVAL; 1411 1412 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1413 map_type = attr->map_type; 1414 if (map_type >= ARRAY_SIZE(bpf_map_types)) 1415 return -EINVAL; 1416 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1417 ops = bpf_map_types[map_type]; 1418 if (!ops) 1419 return -EINVAL; 1420 1421 if (ops->map_alloc_check) { 1422 err = ops->map_alloc_check(attr); 1423 if (err) 1424 return err; 1425 } 1426 if (attr->map_ifindex) 1427 ops = &bpf_map_offload_ops; 1428 if (!ops->map_mem_usage) 1429 return -EINVAL; 1430 1431 if (token_flag) { 1432 token = bpf_token_get_from_fd(attr->map_token_fd); 1433 if (IS_ERR(token)) 1434 return PTR_ERR(token); 1435 1436 /* if current token doesn't grant map creation permissions, 1437 * then we can't use this token, so ignore it and rely on 1438 * system-wide capabilities checks 1439 */ 1440 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || 1441 !bpf_token_allow_map_type(token, attr->map_type)) { 1442 bpf_token_put(token); 1443 token = NULL; 1444 } 1445 } 1446 1447 err = -EPERM; 1448 1449 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1450 * creation for unprivileged users; other actions depend 1451 * on fd availability and access to bpffs, so are dependent on 1452 * object creation success. Even with unprivileged BPF disabled, 1453 * capability checks are still carried out. 1454 */ 1455 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) 1456 goto put_token; 1457 1458 /* check privileged map type permissions */ 1459 switch (map_type) { 1460 case BPF_MAP_TYPE_ARRAY: 1461 case BPF_MAP_TYPE_PERCPU_ARRAY: 1462 case BPF_MAP_TYPE_PROG_ARRAY: 1463 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1464 case BPF_MAP_TYPE_CGROUP_ARRAY: 1465 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1466 case BPF_MAP_TYPE_HASH: 1467 case BPF_MAP_TYPE_PERCPU_HASH: 1468 case BPF_MAP_TYPE_HASH_OF_MAPS: 1469 case BPF_MAP_TYPE_RINGBUF: 1470 case BPF_MAP_TYPE_USER_RINGBUF: 1471 case BPF_MAP_TYPE_CGROUP_STORAGE: 1472 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1473 /* unprivileged */ 1474 break; 1475 case BPF_MAP_TYPE_SK_STORAGE: 1476 case BPF_MAP_TYPE_INODE_STORAGE: 1477 case BPF_MAP_TYPE_TASK_STORAGE: 1478 case BPF_MAP_TYPE_CGRP_STORAGE: 1479 case BPF_MAP_TYPE_BLOOM_FILTER: 1480 case BPF_MAP_TYPE_LPM_TRIE: 1481 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1482 case BPF_MAP_TYPE_STACK_TRACE: 1483 case BPF_MAP_TYPE_QUEUE: 1484 case BPF_MAP_TYPE_STACK: 1485 case BPF_MAP_TYPE_LRU_HASH: 1486 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1487 case BPF_MAP_TYPE_STRUCT_OPS: 1488 case BPF_MAP_TYPE_CPUMAP: 1489 case BPF_MAP_TYPE_ARENA: 1490 case BPF_MAP_TYPE_INSN_ARRAY: 1491 if (!bpf_token_capable(token, CAP_BPF)) 1492 goto put_token; 1493 break; 1494 case BPF_MAP_TYPE_SOCKMAP: 1495 case BPF_MAP_TYPE_SOCKHASH: 1496 case BPF_MAP_TYPE_DEVMAP: 1497 case BPF_MAP_TYPE_DEVMAP_HASH: 1498 case BPF_MAP_TYPE_XSKMAP: 1499 if (!bpf_token_capable(token, CAP_NET_ADMIN)) 1500 goto put_token; 1501 break; 1502 default: 1503 WARN(1, "unsupported map type %d", map_type); 1504 goto put_token; 1505 } 1506 1507 map = ops->map_alloc(attr); 1508 if (IS_ERR(map)) { 1509 err = PTR_ERR(map); 1510 goto put_token; 1511 } 1512 map->ops = ops; 1513 map->map_type = map_type; 1514 1515 err = bpf_obj_name_cpy(map->name, attr->map_name, 1516 sizeof(attr->map_name)); 1517 if (err < 0) 1518 goto free_map; 1519 1520 preempt_disable(); 1521 map->cookie = gen_cookie_next(&bpf_map_cookie); 1522 preempt_enable(); 1523 1524 atomic64_set(&map->refcnt, 1); 1525 atomic64_set(&map->usercnt, 1); 1526 mutex_init(&map->freeze_mutex); 1527 spin_lock_init(&map->owner_lock); 1528 1529 if (attr->btf_key_type_id || attr->btf_value_type_id || 1530 /* Even the map's value is a kernel's struct, 1531 * the bpf_prog.o must have BTF to begin with 1532 * to figure out the corresponding kernel's 1533 * counter part. Thus, attr->btf_fd has 1534 * to be valid also. 1535 */ 1536 attr->btf_vmlinux_value_type_id) { 1537 struct btf *btf; 1538 1539 btf = btf_get_by_fd(attr->btf_fd); 1540 if (IS_ERR(btf)) { 1541 err = PTR_ERR(btf); 1542 goto free_map; 1543 } 1544 if (btf_is_kernel(btf)) { 1545 btf_put(btf); 1546 err = -EACCES; 1547 goto free_map; 1548 } 1549 map->btf = btf; 1550 1551 if (attr->btf_value_type_id) { 1552 err = map_check_btf(map, token, btf, attr->btf_key_type_id, 1553 attr->btf_value_type_id); 1554 if (err) 1555 goto free_map; 1556 } 1557 1558 map->btf_key_type_id = attr->btf_key_type_id; 1559 map->btf_value_type_id = attr->btf_value_type_id; 1560 map->btf_vmlinux_value_type_id = 1561 attr->btf_vmlinux_value_type_id; 1562 } 1563 1564 if (attr->excl_prog_hash) { 1565 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); 1566 1567 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { 1568 err = -EINVAL; 1569 goto free_map; 1570 } 1571 1572 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); 1573 if (!map->excl_prog_sha) { 1574 err = -ENOMEM; 1575 goto free_map; 1576 } 1577 1578 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) { 1579 err = -EFAULT; 1580 goto free_map; 1581 } 1582 } else if (attr->excl_prog_hash_size) { 1583 err = -EINVAL; 1584 goto free_map; 1585 } 1586 1587 err = security_bpf_map_create(map, attr, token, uattr.is_kernel); 1588 if (err) 1589 goto free_map_sec; 1590 1591 err = bpf_map_alloc_id(map); 1592 if (err) 1593 goto free_map_sec; 1594 1595 bpf_map_save_memcg(map); 1596 bpf_token_put(token); 1597 1598 err = bpf_map_new_fd(map, f_flags); 1599 if (err < 0) { 1600 /* failed to allocate fd. 1601 * bpf_map_put_with_uref() is needed because the above 1602 * bpf_map_alloc_id() has published the map 1603 * to the userspace and the userspace may 1604 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1605 */ 1606 bpf_map_put_with_uref(map); 1607 return err; 1608 } 1609 1610 return err; 1611 1612 free_map_sec: 1613 security_bpf_map_free(map); 1614 free_map: 1615 bpf_map_free(map); 1616 put_token: 1617 bpf_token_put(token); 1618 return err; 1619 } 1620 1621 void bpf_map_inc(struct bpf_map *map) 1622 { 1623 atomic64_inc(&map->refcnt); 1624 } 1625 EXPORT_SYMBOL_GPL(bpf_map_inc); 1626 1627 void bpf_map_inc_with_uref(struct bpf_map *map) 1628 { 1629 atomic64_inc(&map->refcnt); 1630 atomic64_inc(&map->usercnt); 1631 } 1632 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1633 1634 struct bpf_map *bpf_map_get(u32 ufd) 1635 { 1636 CLASS(fd, f)(ufd); 1637 struct bpf_map *map = __bpf_map_get(f); 1638 1639 if (!IS_ERR(map)) 1640 bpf_map_inc(map); 1641 1642 return map; 1643 } 1644 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); 1645 1646 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1647 { 1648 CLASS(fd, f)(ufd); 1649 struct bpf_map *map = __bpf_map_get(f); 1650 1651 if (!IS_ERR(map)) 1652 bpf_map_inc_with_uref(map); 1653 1654 return map; 1655 } 1656 1657 /* map_idr_lock should have been held or the map should have been 1658 * protected by rcu read lock. 1659 */ 1660 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1661 { 1662 int refold; 1663 1664 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1665 if (!refold) 1666 return ERR_PTR(-ENOENT); 1667 if (uref) 1668 atomic64_inc(&map->usercnt); 1669 1670 return map; 1671 } 1672 1673 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1674 { 1675 lockdep_assert(rcu_read_lock_held()); 1676 return __bpf_map_inc_not_zero(map, false); 1677 } 1678 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1679 1680 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value, 1681 bool delete) 1682 { 1683 return -ENOTSUPP; 1684 } 1685 1686 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1687 { 1688 if (key_size) 1689 return vmemdup_user(ukey, key_size); 1690 1691 if (ukey) 1692 return ERR_PTR(-EINVAL); 1693 1694 return NULL; 1695 } 1696 1697 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1698 { 1699 if (key_size) 1700 return kvmemdup_bpfptr(ukey, key_size); 1701 1702 if (!bpfptr_is_null(ukey)) 1703 return ERR_PTR(-EINVAL); 1704 1705 return NULL; 1706 } 1707 1708 /* last field in 'union bpf_attr' used by this command */ 1709 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1710 1711 static int map_lookup_elem(union bpf_attr *attr) 1712 { 1713 void __user *ukey = u64_to_user_ptr(attr->key); 1714 void __user *uvalue = u64_to_user_ptr(attr->value); 1715 struct bpf_map *map; 1716 void *key, *value; 1717 u32 value_size; 1718 int err; 1719 1720 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1721 return -EINVAL; 1722 1723 CLASS(fd, f)(attr->map_fd); 1724 map = __bpf_map_get(f); 1725 if (IS_ERR(map)) 1726 return PTR_ERR(map); 1727 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1728 return -EPERM; 1729 1730 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU); 1731 if (err) 1732 return err; 1733 1734 key = __bpf_copy_key(ukey, map->key_size); 1735 if (IS_ERR(key)) 1736 return PTR_ERR(key); 1737 1738 value_size = bpf_map_value_size(map, attr->flags); 1739 1740 err = -ENOMEM; 1741 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1742 if (!value) 1743 goto free_key; 1744 1745 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1746 if (copy_from_user(value, uvalue, value_size)) 1747 err = -EFAULT; 1748 else 1749 err = bpf_map_copy_value(map, key, value, attr->flags); 1750 goto free_value; 1751 } 1752 1753 err = bpf_map_copy_value(map, key, value, attr->flags); 1754 if (err) 1755 goto free_value; 1756 1757 err = -EFAULT; 1758 if (copy_to_user(uvalue, value, value_size) != 0) 1759 goto free_value; 1760 1761 err = 0; 1762 1763 free_value: 1764 kvfree(value); 1765 free_key: 1766 kvfree(key); 1767 return err; 1768 } 1769 1770 1771 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1772 1773 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1774 { 1775 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1776 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1777 struct bpf_map *map; 1778 void *key, *value; 1779 u32 value_size; 1780 int err; 1781 1782 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1783 return -EINVAL; 1784 1785 CLASS(fd, f)(attr->map_fd); 1786 map = __bpf_map_get(f); 1787 if (IS_ERR(map)) 1788 return PTR_ERR(map); 1789 bpf_map_write_active_inc(map); 1790 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1791 err = -EPERM; 1792 goto err_put; 1793 } 1794 1795 err = bpf_map_check_op_flags(map, attr->flags, ~0); 1796 if (err) 1797 goto err_put; 1798 1799 key = ___bpf_copy_key(ukey, map->key_size); 1800 if (IS_ERR(key)) { 1801 err = PTR_ERR(key); 1802 goto err_put; 1803 } 1804 1805 value_size = bpf_map_value_size(map, attr->flags); 1806 value = kvmemdup_bpfptr(uvalue, value_size); 1807 if (IS_ERR(value)) { 1808 err = PTR_ERR(value); 1809 goto free_key; 1810 } 1811 1812 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); 1813 if (!err) 1814 maybe_wait_bpf_programs(map); 1815 1816 kvfree(value); 1817 free_key: 1818 kvfree(key); 1819 err_put: 1820 bpf_map_write_active_dec(map); 1821 return err; 1822 } 1823 1824 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1825 1826 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1827 { 1828 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1829 struct bpf_map *map; 1830 void *key; 1831 int err; 1832 1833 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1834 return -EINVAL; 1835 1836 CLASS(fd, f)(attr->map_fd); 1837 map = __bpf_map_get(f); 1838 if (IS_ERR(map)) 1839 return PTR_ERR(map); 1840 bpf_map_write_active_inc(map); 1841 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1842 err = -EPERM; 1843 goto err_put; 1844 } 1845 1846 key = ___bpf_copy_key(ukey, map->key_size); 1847 if (IS_ERR(key)) { 1848 err = PTR_ERR(key); 1849 goto err_put; 1850 } 1851 1852 if (bpf_map_is_offloaded(map)) { 1853 err = bpf_map_offload_delete_elem(map, key); 1854 goto out; 1855 } else if (IS_FD_PROG_ARRAY(map) || 1856 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1857 /* These maps require sleepable context */ 1858 err = map->ops->map_delete_elem(map, key); 1859 goto out; 1860 } 1861 1862 bpf_disable_instrumentation(); 1863 rcu_read_lock(); 1864 err = map->ops->map_delete_elem(map, key); 1865 rcu_read_unlock(); 1866 bpf_enable_instrumentation(); 1867 if (!err) 1868 maybe_wait_bpf_programs(map); 1869 out: 1870 kvfree(key); 1871 err_put: 1872 bpf_map_write_active_dec(map); 1873 return err; 1874 } 1875 1876 /* last field in 'union bpf_attr' used by this command */ 1877 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1878 1879 static int map_get_next_key(union bpf_attr *attr) 1880 { 1881 void __user *ukey = u64_to_user_ptr(attr->key); 1882 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1883 struct bpf_map *map; 1884 void *key, *next_key; 1885 int err; 1886 1887 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1888 return -EINVAL; 1889 1890 CLASS(fd, f)(attr->map_fd); 1891 map = __bpf_map_get(f); 1892 if (IS_ERR(map)) 1893 return PTR_ERR(map); 1894 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1895 return -EPERM; 1896 1897 if (ukey) { 1898 key = __bpf_copy_key(ukey, map->key_size); 1899 if (IS_ERR(key)) 1900 return PTR_ERR(key); 1901 } else { 1902 key = NULL; 1903 } 1904 1905 err = -ENOMEM; 1906 next_key = kvmalloc(map->key_size, GFP_USER); 1907 if (!next_key) 1908 goto free_key; 1909 1910 if (bpf_map_is_offloaded(map)) { 1911 err = bpf_map_offload_get_next_key(map, key, next_key); 1912 goto out; 1913 } 1914 1915 rcu_read_lock(); 1916 err = map->ops->map_get_next_key(map, key, next_key); 1917 rcu_read_unlock(); 1918 out: 1919 if (err) 1920 goto free_next_key; 1921 1922 err = -EFAULT; 1923 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1924 goto free_next_key; 1925 1926 err = 0; 1927 1928 free_next_key: 1929 kvfree(next_key); 1930 free_key: 1931 kvfree(key); 1932 return err; 1933 } 1934 1935 int generic_map_delete_batch(struct bpf_map *map, 1936 const union bpf_attr *attr, 1937 union bpf_attr __user *uattr) 1938 { 1939 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1940 u32 cp, max_count; 1941 int err = 0; 1942 void *key; 1943 1944 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1945 return -EINVAL; 1946 1947 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1948 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1949 return -EINVAL; 1950 } 1951 1952 max_count = attr->batch.count; 1953 if (!max_count) 1954 return 0; 1955 1956 if (put_user(0, &uattr->batch.count)) 1957 return -EFAULT; 1958 1959 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1960 if (!key) 1961 return -ENOMEM; 1962 1963 for (cp = 0; cp < max_count; cp++) { 1964 err = -EFAULT; 1965 if (copy_from_user(key, keys + cp * map->key_size, 1966 map->key_size)) 1967 break; 1968 1969 if (bpf_map_is_offloaded(map)) { 1970 err = bpf_map_offload_delete_elem(map, key); 1971 break; 1972 } 1973 1974 bpf_disable_instrumentation(); 1975 rcu_read_lock(); 1976 err = map->ops->map_delete_elem(map, key); 1977 rcu_read_unlock(); 1978 bpf_enable_instrumentation(); 1979 if (err) 1980 break; 1981 cond_resched(); 1982 } 1983 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1984 err = -EFAULT; 1985 1986 kvfree(key); 1987 1988 return err; 1989 } 1990 1991 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 1992 const union bpf_attr *attr, 1993 union bpf_attr __user *uattr) 1994 { 1995 void __user *values = u64_to_user_ptr(attr->batch.values); 1996 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1997 u32 value_size, cp, max_count; 1998 void *key, *value; 1999 int err = 0; 2000 2001 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, 2002 BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS); 2003 if (err) 2004 return err; 2005 2006 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2007 2008 max_count = attr->batch.count; 2009 if (!max_count) 2010 return 0; 2011 2012 if (put_user(0, &uattr->batch.count)) 2013 return -EFAULT; 2014 2015 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2016 if (!key) 2017 return -ENOMEM; 2018 2019 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2020 if (!value) { 2021 kvfree(key); 2022 return -ENOMEM; 2023 } 2024 2025 for (cp = 0; cp < max_count; cp++) { 2026 err = -EFAULT; 2027 if (copy_from_user(key, keys + cp * map->key_size, 2028 map->key_size) || 2029 copy_from_user(value, values + cp * value_size, value_size)) 2030 break; 2031 2032 err = bpf_map_update_value(map, map_file, key, value, 2033 attr->batch.elem_flags); 2034 2035 if (err) 2036 break; 2037 cond_resched(); 2038 } 2039 2040 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2041 err = -EFAULT; 2042 2043 kvfree(value); 2044 kvfree(key); 2045 2046 return err; 2047 } 2048 2049 int generic_map_lookup_batch(struct bpf_map *map, 2050 const union bpf_attr *attr, 2051 union bpf_attr __user *uattr) 2052 { 2053 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 2054 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 2055 void __user *values = u64_to_user_ptr(attr->batch.values); 2056 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2057 void *buf, *buf_prevkey, *prev_key, *key, *value; 2058 u32 value_size, cp, max_count; 2059 int err; 2060 2061 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU); 2062 if (err) 2063 return err; 2064 2065 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2066 2067 max_count = attr->batch.count; 2068 if (!max_count) 2069 return 0; 2070 2071 if (put_user(0, &uattr->batch.count)) 2072 return -EFAULT; 2073 2074 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2075 if (!buf_prevkey) 2076 return -ENOMEM; 2077 2078 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 2079 if (!buf) { 2080 kvfree(buf_prevkey); 2081 return -ENOMEM; 2082 } 2083 2084 err = -EFAULT; 2085 prev_key = NULL; 2086 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 2087 goto free_buf; 2088 key = buf; 2089 value = key + map->key_size; 2090 if (ubatch) 2091 prev_key = buf_prevkey; 2092 2093 for (cp = 0; cp < max_count;) { 2094 rcu_read_lock(); 2095 err = map->ops->map_get_next_key(map, prev_key, key); 2096 rcu_read_unlock(); 2097 if (err) 2098 break; 2099 err = bpf_map_copy_value(map, key, value, 2100 attr->batch.elem_flags); 2101 2102 if (err == -ENOENT) 2103 goto next_key; 2104 2105 if (err) 2106 goto free_buf; 2107 2108 if (copy_to_user(keys + cp * map->key_size, key, 2109 map->key_size)) { 2110 err = -EFAULT; 2111 goto free_buf; 2112 } 2113 if (copy_to_user(values + cp * value_size, value, value_size)) { 2114 err = -EFAULT; 2115 goto free_buf; 2116 } 2117 2118 cp++; 2119 next_key: 2120 if (!prev_key) 2121 prev_key = buf_prevkey; 2122 2123 swap(prev_key, key); 2124 cond_resched(); 2125 } 2126 2127 if (err == -EFAULT) 2128 goto free_buf; 2129 2130 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 2131 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 2132 err = -EFAULT; 2133 2134 free_buf: 2135 kvfree(buf_prevkey); 2136 kvfree(buf); 2137 return err; 2138 } 2139 2140 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 2141 2142 static int map_lookup_and_delete_elem(union bpf_attr *attr) 2143 { 2144 void __user *ukey = u64_to_user_ptr(attr->key); 2145 void __user *uvalue = u64_to_user_ptr(attr->value); 2146 struct bpf_map *map; 2147 void *key, *value; 2148 u32 value_size; 2149 int err; 2150 2151 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 2152 return -EINVAL; 2153 2154 if (attr->flags & ~BPF_F_LOCK) 2155 return -EINVAL; 2156 2157 CLASS(fd, f)(attr->map_fd); 2158 map = __bpf_map_get(f); 2159 if (IS_ERR(map)) 2160 return PTR_ERR(map); 2161 bpf_map_write_active_inc(map); 2162 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 2163 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2164 err = -EPERM; 2165 goto err_put; 2166 } 2167 2168 if (attr->flags && 2169 (map->map_type == BPF_MAP_TYPE_QUEUE || 2170 map->map_type == BPF_MAP_TYPE_STACK)) { 2171 err = -EINVAL; 2172 goto err_put; 2173 } 2174 2175 if ((attr->flags & BPF_F_LOCK) && 2176 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2177 err = -EINVAL; 2178 goto err_put; 2179 } 2180 2181 key = __bpf_copy_key(ukey, map->key_size); 2182 if (IS_ERR(key)) { 2183 err = PTR_ERR(key); 2184 goto err_put; 2185 } 2186 2187 value_size = bpf_map_value_size(map, 0); 2188 2189 err = -ENOMEM; 2190 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2191 if (!value) 2192 goto free_key; 2193 2194 err = -ENOTSUPP; 2195 if (map->map_type == BPF_MAP_TYPE_QUEUE || 2196 map->map_type == BPF_MAP_TYPE_STACK) { 2197 err = map->ops->map_pop_elem(map, value); 2198 } else if (map->map_type == BPF_MAP_TYPE_HASH || 2199 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 2200 map->map_type == BPF_MAP_TYPE_LRU_HASH || 2201 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 2202 map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 2203 if (!bpf_map_is_offloaded(map)) { 2204 bpf_disable_instrumentation(); 2205 rcu_read_lock(); 2206 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 2207 rcu_read_unlock(); 2208 bpf_enable_instrumentation(); 2209 } 2210 } 2211 2212 if (err) 2213 goto free_value; 2214 2215 if (copy_to_user(uvalue, value, value_size) != 0) { 2216 err = -EFAULT; 2217 goto free_value; 2218 } 2219 2220 err = 0; 2221 2222 free_value: 2223 kvfree(value); 2224 free_key: 2225 kvfree(key); 2226 err_put: 2227 bpf_map_write_active_dec(map); 2228 return err; 2229 } 2230 2231 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2232 2233 static int map_freeze(const union bpf_attr *attr) 2234 { 2235 int err = 0; 2236 struct bpf_map *map; 2237 2238 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2239 return -EINVAL; 2240 2241 CLASS(fd, f)(attr->map_fd); 2242 map = __bpf_map_get(f); 2243 if (IS_ERR(map)) 2244 return PTR_ERR(map); 2245 2246 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) 2247 return -ENOTSUPP; 2248 2249 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) 2250 return -EPERM; 2251 2252 mutex_lock(&map->freeze_mutex); 2253 if (bpf_map_write_active(map)) { 2254 err = -EBUSY; 2255 goto err_put; 2256 } 2257 if (READ_ONCE(map->frozen)) { 2258 err = -EBUSY; 2259 goto err_put; 2260 } 2261 2262 WRITE_ONCE(map->frozen, true); 2263 err_put: 2264 mutex_unlock(&map->freeze_mutex); 2265 return err; 2266 } 2267 2268 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2269 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2270 [_id] = & _name ## _prog_ops, 2271 #define BPF_MAP_TYPE(_id, _ops) 2272 #define BPF_LINK_TYPE(_id, _name) 2273 #include <linux/bpf_types.h> 2274 #undef BPF_PROG_TYPE 2275 #undef BPF_MAP_TYPE 2276 #undef BPF_LINK_TYPE 2277 }; 2278 2279 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2280 { 2281 const struct bpf_prog_ops *ops; 2282 2283 if (type >= ARRAY_SIZE(bpf_prog_types)) 2284 return -EINVAL; 2285 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2286 ops = bpf_prog_types[type]; 2287 if (!ops) 2288 return -EINVAL; 2289 2290 if (!bpf_prog_is_offloaded(prog->aux)) 2291 prog->aux->ops = ops; 2292 else 2293 prog->aux->ops = &bpf_offload_prog_ops; 2294 prog->type = type; 2295 return 0; 2296 } 2297 2298 enum bpf_audit { 2299 BPF_AUDIT_LOAD, 2300 BPF_AUDIT_UNLOAD, 2301 BPF_AUDIT_MAX, 2302 }; 2303 2304 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2305 [BPF_AUDIT_LOAD] = "LOAD", 2306 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2307 }; 2308 2309 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2310 { 2311 struct audit_context *ctx = NULL; 2312 struct audit_buffer *ab; 2313 2314 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2315 return; 2316 if (audit_enabled == AUDIT_OFF) 2317 return; 2318 if (!in_hardirq() && !irqs_disabled()) 2319 ctx = audit_context(); 2320 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2321 if (unlikely(!ab)) 2322 return; 2323 audit_log_format(ab, "prog-id=%u op=%s", 2324 prog->aux->id, bpf_audit_str[op]); 2325 audit_log_end(ab); 2326 } 2327 2328 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2329 { 2330 int id; 2331 2332 idr_preload(GFP_KERNEL); 2333 spin_lock_bh(&prog_idr_lock); 2334 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2335 if (id > 0) 2336 prog->aux->id = id; 2337 spin_unlock_bh(&prog_idr_lock); 2338 idr_preload_end(); 2339 2340 /* id is in [1, INT_MAX) */ 2341 if (WARN_ON_ONCE(!id)) 2342 return -ENOSPC; 2343 2344 return id > 0 ? 0 : id; 2345 } 2346 2347 void bpf_prog_free_id(struct bpf_prog *prog) 2348 { 2349 unsigned long flags; 2350 2351 /* cBPF to eBPF migrations are currently not in the idr store. 2352 * Offloaded programs are removed from the store when their device 2353 * disappears - even if someone grabs an fd to them they are unusable, 2354 * simply waiting for refcnt to drop to be freed. 2355 */ 2356 if (!prog->aux->id) 2357 return; 2358 2359 spin_lock_irqsave(&prog_idr_lock, flags); 2360 idr_remove(&prog_idr, prog->aux->id); 2361 prog->aux->id = 0; 2362 spin_unlock_irqrestore(&prog_idr_lock, flags); 2363 } 2364 2365 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2366 { 2367 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2368 2369 kvfree(aux->func_info); 2370 kfree(aux->func_info_aux); 2371 free_uid(aux->user); 2372 security_bpf_prog_free(aux->prog); 2373 bpf_prog_free(aux->prog); 2374 } 2375 2376 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2377 { 2378 bpf_prog_kallsyms_del_all(prog); 2379 btf_put(prog->aux->btf); 2380 module_put(prog->aux->mod); 2381 kvfree(prog->aux->jited_linfo); 2382 kvfree(prog->aux->linfo); 2383 kfree(prog->aux->kfunc_tab); 2384 kfree(prog->aux->ctx_arg_info); 2385 if (prog->aux->attach_btf) 2386 btf_put(prog->aux->attach_btf); 2387 2388 if (deferred) { 2389 if (prog->sleepable) 2390 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2391 else 2392 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2393 } else { 2394 __bpf_prog_put_rcu(&prog->aux->rcu); 2395 } 2396 } 2397 2398 static void bpf_prog_put_deferred(struct work_struct *work) 2399 { 2400 struct bpf_prog_aux *aux; 2401 struct bpf_prog *prog; 2402 2403 aux = container_of(work, struct bpf_prog_aux, work); 2404 prog = aux->prog; 2405 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2406 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2407 bpf_prog_free_id(prog); 2408 __bpf_prog_put_noref(prog, true); 2409 } 2410 2411 static void __bpf_prog_put(struct bpf_prog *prog) 2412 { 2413 struct bpf_prog_aux *aux = prog->aux; 2414 2415 if (atomic64_dec_and_test(&aux->refcnt)) { 2416 if (in_hardirq() || irqs_disabled()) { 2417 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2418 schedule_work(&aux->work); 2419 } else { 2420 bpf_prog_put_deferred(&aux->work); 2421 } 2422 } 2423 } 2424 2425 void bpf_prog_put(struct bpf_prog *prog) 2426 { 2427 __bpf_prog_put(prog); 2428 } 2429 EXPORT_SYMBOL_GPL(bpf_prog_put); 2430 2431 static int bpf_prog_release(struct inode *inode, struct file *filp) 2432 { 2433 struct bpf_prog *prog = filp->private_data; 2434 2435 bpf_prog_put(prog); 2436 return 0; 2437 } 2438 2439 struct bpf_prog_kstats { 2440 u64 nsecs; 2441 u64 cnt; 2442 u64 misses; 2443 }; 2444 2445 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2446 { 2447 struct bpf_prog_stats *stats; 2448 unsigned int flags; 2449 2450 if (unlikely(!prog->stats)) 2451 return; 2452 2453 stats = this_cpu_ptr(prog->stats); 2454 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2455 u64_stats_inc(&stats->misses); 2456 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2457 } 2458 2459 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2460 struct bpf_prog_kstats *stats) 2461 { 2462 u64 nsecs = 0, cnt = 0, misses = 0; 2463 int cpu; 2464 2465 for_each_possible_cpu(cpu) { 2466 const struct bpf_prog_stats *st; 2467 unsigned int start; 2468 u64 tnsecs, tcnt, tmisses; 2469 2470 st = per_cpu_ptr(prog->stats, cpu); 2471 do { 2472 start = u64_stats_fetch_begin(&st->syncp); 2473 tnsecs = u64_stats_read(&st->nsecs); 2474 tcnt = u64_stats_read(&st->cnt); 2475 tmisses = u64_stats_read(&st->misses); 2476 } while (u64_stats_fetch_retry(&st->syncp, start)); 2477 nsecs += tnsecs; 2478 cnt += tcnt; 2479 misses += tmisses; 2480 } 2481 stats->nsecs = nsecs; 2482 stats->cnt = cnt; 2483 stats->misses = misses; 2484 } 2485 2486 #ifdef CONFIG_PROC_FS 2487 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2488 { 2489 const struct bpf_prog *prog = filp->private_data; 2490 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2491 struct bpf_prog_kstats stats; 2492 2493 bpf_prog_get_stats(prog, &stats); 2494 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2495 seq_printf(m, 2496 "prog_type:\t%u\n" 2497 "prog_jited:\t%u\n" 2498 "prog_tag:\t%s\n" 2499 "memlock:\t%llu\n" 2500 "prog_id:\t%u\n" 2501 "run_time_ns:\t%llu\n" 2502 "run_cnt:\t%llu\n" 2503 "recursion_misses:\t%llu\n" 2504 "verified_insns:\t%u\n", 2505 prog->type, 2506 prog->jited, 2507 prog_tag, 2508 prog->pages * 1ULL << PAGE_SHIFT, 2509 prog->aux->id, 2510 stats.nsecs, 2511 stats.cnt, 2512 stats.misses, 2513 prog->aux->verified_insns); 2514 } 2515 #endif 2516 2517 const struct file_operations bpf_prog_fops = { 2518 #ifdef CONFIG_PROC_FS 2519 .show_fdinfo = bpf_prog_show_fdinfo, 2520 #endif 2521 .release = bpf_prog_release, 2522 .read = bpf_dummy_read, 2523 .write = bpf_dummy_write, 2524 }; 2525 2526 int bpf_prog_new_fd(struct bpf_prog *prog) 2527 { 2528 int ret; 2529 2530 ret = security_bpf_prog(prog); 2531 if (ret < 0) 2532 return ret; 2533 2534 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2535 O_RDWR | O_CLOEXEC); 2536 } 2537 2538 void bpf_prog_add(struct bpf_prog *prog, int i) 2539 { 2540 atomic64_add(i, &prog->aux->refcnt); 2541 } 2542 EXPORT_SYMBOL_GPL(bpf_prog_add); 2543 2544 void bpf_prog_sub(struct bpf_prog *prog, int i) 2545 { 2546 /* Only to be used for undoing previous bpf_prog_add() in some 2547 * error path. We still know that another entity in our call 2548 * path holds a reference to the program, thus atomic_sub() can 2549 * be safely used in such cases! 2550 */ 2551 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2552 } 2553 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2554 2555 void bpf_prog_inc(struct bpf_prog *prog) 2556 { 2557 atomic64_inc(&prog->aux->refcnt); 2558 } 2559 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2560 2561 /* prog_idr_lock should have been held */ 2562 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2563 { 2564 int refold; 2565 2566 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2567 2568 if (!refold) 2569 return ERR_PTR(-ENOENT); 2570 2571 return prog; 2572 } 2573 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2574 2575 bool bpf_prog_get_ok(struct bpf_prog *prog, 2576 enum bpf_prog_type *attach_type, bool attach_drv) 2577 { 2578 /* not an attachment, just a refcount inc, always allow */ 2579 if (!attach_type) 2580 return true; 2581 2582 if (prog->type != *attach_type) 2583 return false; 2584 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2585 return false; 2586 2587 return true; 2588 } 2589 2590 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2591 bool attach_drv) 2592 { 2593 CLASS(fd, f)(ufd); 2594 struct bpf_prog *prog; 2595 2596 if (fd_empty(f)) 2597 return ERR_PTR(-EBADF); 2598 if (fd_file(f)->f_op != &bpf_prog_fops) 2599 return ERR_PTR(-EINVAL); 2600 2601 prog = fd_file(f)->private_data; 2602 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2603 return ERR_PTR(-EINVAL); 2604 2605 bpf_prog_inc(prog); 2606 return prog; 2607 } 2608 2609 struct bpf_prog *bpf_prog_get(u32 ufd) 2610 { 2611 return __bpf_prog_get(ufd, NULL, false); 2612 } 2613 2614 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2615 bool attach_drv) 2616 { 2617 return __bpf_prog_get(ufd, &type, attach_drv); 2618 } 2619 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2620 2621 /* Initially all BPF programs could be loaded w/o specifying 2622 * expected_attach_type. Later for some of them specifying expected_attach_type 2623 * at load time became required so that program could be validated properly. 2624 * Programs of types that are allowed to be loaded both w/ and w/o (for 2625 * backward compatibility) expected_attach_type, should have the default attach 2626 * type assigned to expected_attach_type for the latter case, so that it can be 2627 * validated later at attach time. 2628 * 2629 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2630 * prog type requires it but has some attach types that have to be backward 2631 * compatible. 2632 */ 2633 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2634 { 2635 switch (attr->prog_type) { 2636 case BPF_PROG_TYPE_CGROUP_SOCK: 2637 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2638 * exist so checking for non-zero is the way to go here. 2639 */ 2640 if (!attr->expected_attach_type) 2641 attr->expected_attach_type = 2642 BPF_CGROUP_INET_SOCK_CREATE; 2643 break; 2644 case BPF_PROG_TYPE_SK_REUSEPORT: 2645 if (!attr->expected_attach_type) 2646 attr->expected_attach_type = 2647 BPF_SK_REUSEPORT_SELECT; 2648 break; 2649 } 2650 } 2651 2652 static int 2653 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2654 enum bpf_attach_type expected_attach_type, 2655 struct btf *attach_btf, u32 btf_id, 2656 struct bpf_prog *dst_prog) 2657 { 2658 if (btf_id) { 2659 if (btf_id > BTF_MAX_TYPE) 2660 return -EINVAL; 2661 2662 if (!attach_btf && !dst_prog) 2663 return -EINVAL; 2664 2665 switch (prog_type) { 2666 case BPF_PROG_TYPE_TRACING: 2667 case BPF_PROG_TYPE_LSM: 2668 case BPF_PROG_TYPE_STRUCT_OPS: 2669 case BPF_PROG_TYPE_EXT: 2670 break; 2671 default: 2672 return -EINVAL; 2673 } 2674 } 2675 2676 if (attach_btf && (!btf_id || dst_prog)) 2677 return -EINVAL; 2678 2679 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2680 prog_type != BPF_PROG_TYPE_EXT) 2681 return -EINVAL; 2682 2683 switch (prog_type) { 2684 case BPF_PROG_TYPE_CGROUP_SOCK: 2685 switch (expected_attach_type) { 2686 case BPF_CGROUP_INET_SOCK_CREATE: 2687 case BPF_CGROUP_INET_SOCK_RELEASE: 2688 case BPF_CGROUP_INET4_POST_BIND: 2689 case BPF_CGROUP_INET6_POST_BIND: 2690 return 0; 2691 default: 2692 return -EINVAL; 2693 } 2694 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2695 switch (expected_attach_type) { 2696 case BPF_CGROUP_INET4_BIND: 2697 case BPF_CGROUP_INET6_BIND: 2698 case BPF_CGROUP_INET4_CONNECT: 2699 case BPF_CGROUP_INET6_CONNECT: 2700 case BPF_CGROUP_UNIX_CONNECT: 2701 case BPF_CGROUP_INET4_GETPEERNAME: 2702 case BPF_CGROUP_INET6_GETPEERNAME: 2703 case BPF_CGROUP_UNIX_GETPEERNAME: 2704 case BPF_CGROUP_INET4_GETSOCKNAME: 2705 case BPF_CGROUP_INET6_GETSOCKNAME: 2706 case BPF_CGROUP_UNIX_GETSOCKNAME: 2707 case BPF_CGROUP_UDP4_SENDMSG: 2708 case BPF_CGROUP_UDP6_SENDMSG: 2709 case BPF_CGROUP_UNIX_SENDMSG: 2710 case BPF_CGROUP_UDP4_RECVMSG: 2711 case BPF_CGROUP_UDP6_RECVMSG: 2712 case BPF_CGROUP_UNIX_RECVMSG: 2713 return 0; 2714 default: 2715 return -EINVAL; 2716 } 2717 case BPF_PROG_TYPE_CGROUP_SKB: 2718 switch (expected_attach_type) { 2719 case BPF_CGROUP_INET_INGRESS: 2720 case BPF_CGROUP_INET_EGRESS: 2721 return 0; 2722 default: 2723 return -EINVAL; 2724 } 2725 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2726 switch (expected_attach_type) { 2727 case BPF_CGROUP_SETSOCKOPT: 2728 case BPF_CGROUP_GETSOCKOPT: 2729 return 0; 2730 default: 2731 return -EINVAL; 2732 } 2733 case BPF_PROG_TYPE_SK_LOOKUP: 2734 if (expected_attach_type == BPF_SK_LOOKUP) 2735 return 0; 2736 return -EINVAL; 2737 case BPF_PROG_TYPE_SK_REUSEPORT: 2738 switch (expected_attach_type) { 2739 case BPF_SK_REUSEPORT_SELECT: 2740 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2741 return 0; 2742 default: 2743 return -EINVAL; 2744 } 2745 case BPF_PROG_TYPE_NETFILTER: 2746 if (expected_attach_type == BPF_NETFILTER) 2747 return 0; 2748 return -EINVAL; 2749 case BPF_PROG_TYPE_SYSCALL: 2750 case BPF_PROG_TYPE_EXT: 2751 if (expected_attach_type) 2752 return -EINVAL; 2753 fallthrough; 2754 default: 2755 return 0; 2756 } 2757 } 2758 2759 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2760 { 2761 switch (prog_type) { 2762 case BPF_PROG_TYPE_SCHED_CLS: 2763 case BPF_PROG_TYPE_SCHED_ACT: 2764 case BPF_PROG_TYPE_XDP: 2765 case BPF_PROG_TYPE_LWT_IN: 2766 case BPF_PROG_TYPE_LWT_OUT: 2767 case BPF_PROG_TYPE_LWT_XMIT: 2768 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2769 case BPF_PROG_TYPE_SK_SKB: 2770 case BPF_PROG_TYPE_SK_MSG: 2771 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2772 case BPF_PROG_TYPE_CGROUP_DEVICE: 2773 case BPF_PROG_TYPE_CGROUP_SOCK: 2774 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2775 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2776 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2777 case BPF_PROG_TYPE_SOCK_OPS: 2778 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2779 case BPF_PROG_TYPE_NETFILTER: 2780 return true; 2781 case BPF_PROG_TYPE_CGROUP_SKB: 2782 /* always unpriv */ 2783 case BPF_PROG_TYPE_SK_REUSEPORT: 2784 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2785 default: 2786 return false; 2787 } 2788 } 2789 2790 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2791 { 2792 switch (prog_type) { 2793 case BPF_PROG_TYPE_KPROBE: 2794 case BPF_PROG_TYPE_TRACEPOINT: 2795 case BPF_PROG_TYPE_PERF_EVENT: 2796 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2797 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2798 case BPF_PROG_TYPE_TRACING: 2799 case BPF_PROG_TYPE_LSM: 2800 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2801 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2802 return true; 2803 default: 2804 return false; 2805 } 2806 } 2807 2808 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr, 2809 bool is_kernel) 2810 { 2811 bpfptr_t usig = make_bpfptr(attr->signature, is_kernel); 2812 struct bpf_dynptr_kern sig_ptr, insns_ptr; 2813 struct bpf_key *key = NULL; 2814 void *sig; 2815 int err = 0; 2816 2817 /* 2818 * Don't attempt to use kmalloc_large or vmalloc for signatures. 2819 * Practical signature for BPF program should be below this limit. 2820 */ 2821 if (attr->signature_size > KMALLOC_MAX_CACHE_SIZE) 2822 return -EINVAL; 2823 2824 if (system_keyring_id_check(attr->keyring_id) == 0) 2825 key = bpf_lookup_system_key(attr->keyring_id); 2826 else 2827 key = bpf_lookup_user_key(attr->keyring_id, 0); 2828 2829 if (!key) 2830 return -EINVAL; 2831 2832 sig = kvmemdup_bpfptr(usig, attr->signature_size); 2833 if (IS_ERR(sig)) { 2834 bpf_key_put(key); 2835 return -ENOMEM; 2836 } 2837 2838 bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0, 2839 attr->signature_size); 2840 bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0, 2841 prog->len * sizeof(struct bpf_insn)); 2842 2843 err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr, 2844 (struct bpf_dynptr *)&sig_ptr, key); 2845 2846 bpf_key_put(key); 2847 kvfree(sig); 2848 return err; 2849 } 2850 2851 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) 2852 { 2853 int err; 2854 int i; 2855 2856 for (i = 0; i < prog->aux->used_map_cnt; i++) { 2857 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY) 2858 continue; 2859 2860 err = bpf_insn_array_ready(prog->aux->used_maps[i]); 2861 if (err) 2862 return err; 2863 } 2864 2865 return 0; 2866 } 2867 2868 /* last field in 'union bpf_attr' used by this command */ 2869 #define BPF_PROG_LOAD_LAST_FIELD keyring_id 2870 2871 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) 2872 { 2873 enum bpf_prog_type type = attr->prog_type; 2874 struct bpf_prog *prog, *dst_prog = NULL; 2875 struct btf *attach_btf = NULL; 2876 struct bpf_token *token = NULL; 2877 bool bpf_cap; 2878 int err; 2879 char license[128]; 2880 2881 if (CHECK_ATTR(BPF_PROG_LOAD)) 2882 return -EINVAL; 2883 2884 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2885 BPF_F_ANY_ALIGNMENT | 2886 BPF_F_TEST_STATE_FREQ | 2887 BPF_F_SLEEPABLE | 2888 BPF_F_TEST_RND_HI32 | 2889 BPF_F_XDP_HAS_FRAGS | 2890 BPF_F_XDP_DEV_BOUND_ONLY | 2891 BPF_F_TEST_REG_INVARIANTS | 2892 BPF_F_TOKEN_FD)) 2893 return -EINVAL; 2894 2895 bpf_prog_load_fixup_attach_type(attr); 2896 2897 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2898 token = bpf_token_get_from_fd(attr->prog_token_fd); 2899 if (IS_ERR(token)) 2900 return PTR_ERR(token); 2901 /* if current token doesn't grant prog loading permissions, 2902 * then we can't use this token, so ignore it and rely on 2903 * system-wide capabilities checks 2904 */ 2905 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2906 !bpf_token_allow_prog_type(token, attr->prog_type, 2907 attr->expected_attach_type)) { 2908 bpf_token_put(token); 2909 token = NULL; 2910 } 2911 } 2912 2913 bpf_cap = bpf_token_capable(token, CAP_BPF); 2914 err = -EPERM; 2915 2916 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2917 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2918 !bpf_cap) 2919 goto put_token; 2920 2921 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2922 * creation for unprivileged users; other actions depend 2923 * on fd availability and access to bpffs, so are dependent on 2924 * object creation success. Even with unprivileged BPF disabled, 2925 * capability checks are still carried out for these 2926 * and other operations. 2927 */ 2928 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 2929 goto put_token; 2930 2931 if (attr->insn_cnt == 0 || 2932 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 2933 err = -E2BIG; 2934 goto put_token; 2935 } 2936 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2937 type != BPF_PROG_TYPE_CGROUP_SKB && 2938 !bpf_cap) 2939 goto put_token; 2940 2941 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 2942 goto put_token; 2943 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 2944 goto put_token; 2945 2946 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 2947 * or btf, we need to check which one it is 2948 */ 2949 if (attr->attach_prog_fd) { 2950 dst_prog = bpf_prog_get(attr->attach_prog_fd); 2951 if (IS_ERR(dst_prog)) { 2952 dst_prog = NULL; 2953 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 2954 if (IS_ERR(attach_btf)) { 2955 err = -EINVAL; 2956 goto put_token; 2957 } 2958 if (!btf_is_kernel(attach_btf)) { 2959 /* attaching through specifying bpf_prog's BTF 2960 * objects directly might be supported eventually 2961 */ 2962 btf_put(attach_btf); 2963 err = -ENOTSUPP; 2964 goto put_token; 2965 } 2966 } 2967 } else if (attr->attach_btf_id) { 2968 /* fall back to vmlinux BTF, if BTF type ID is specified */ 2969 attach_btf = bpf_get_btf_vmlinux(); 2970 if (IS_ERR(attach_btf)) { 2971 err = PTR_ERR(attach_btf); 2972 goto put_token; 2973 } 2974 if (!attach_btf) { 2975 err = -EINVAL; 2976 goto put_token; 2977 } 2978 btf_get(attach_btf); 2979 } 2980 2981 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 2982 attach_btf, attr->attach_btf_id, 2983 dst_prog)) { 2984 if (dst_prog) 2985 bpf_prog_put(dst_prog); 2986 if (attach_btf) 2987 btf_put(attach_btf); 2988 err = -EINVAL; 2989 goto put_token; 2990 } 2991 2992 /* plain bpf_prog allocation */ 2993 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 2994 if (!prog) { 2995 if (dst_prog) 2996 bpf_prog_put(dst_prog); 2997 if (attach_btf) 2998 btf_put(attach_btf); 2999 err = -EINVAL; 3000 goto put_token; 3001 } 3002 3003 prog->expected_attach_type = attr->expected_attach_type; 3004 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 3005 prog->aux->attach_btf = attach_btf; 3006 prog->aux->attach_btf_id = attr->attach_btf_id; 3007 prog->aux->dst_prog = dst_prog; 3008 prog->aux->dev_bound = !!attr->prog_ifindex; 3009 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 3010 3011 /* move token into prog->aux, reuse taken refcnt */ 3012 prog->aux->token = token; 3013 token = NULL; 3014 3015 prog->aux->user = get_current_user(); 3016 prog->len = attr->insn_cnt; 3017 3018 err = -EFAULT; 3019 if (copy_from_bpfptr(prog->insns, 3020 make_bpfptr(attr->insns, uattr.is_kernel), 3021 bpf_prog_insn_size(prog)) != 0) 3022 goto free_prog; 3023 /* copy eBPF program license from user space */ 3024 if (strncpy_from_bpfptr(license, 3025 make_bpfptr(attr->license, uattr.is_kernel), 3026 sizeof(license) - 1) < 0) 3027 goto free_prog; 3028 license[sizeof(license) - 1] = 0; 3029 3030 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 3031 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 3032 3033 if (attr->signature) { 3034 err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel); 3035 if (err) 3036 goto free_prog; 3037 } 3038 3039 prog->orig_prog = NULL; 3040 prog->jited = 0; 3041 3042 atomic64_set(&prog->aux->refcnt, 1); 3043 3044 if (bpf_prog_is_dev_bound(prog->aux)) { 3045 err = bpf_prog_dev_bound_init(prog, attr); 3046 if (err) 3047 goto free_prog; 3048 } 3049 3050 if (type == BPF_PROG_TYPE_EXT && dst_prog && 3051 bpf_prog_is_dev_bound(dst_prog->aux)) { 3052 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 3053 if (err) 3054 goto free_prog; 3055 } 3056 3057 /* 3058 * Bookkeeping for managing the program attachment chain. 3059 * 3060 * It might be tempting to set attach_tracing_prog flag at the attachment 3061 * time, but this will not prevent from loading bunch of tracing prog 3062 * first, then attach them one to another. 3063 * 3064 * The flag attach_tracing_prog is set for the whole program lifecycle, and 3065 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 3066 * programs cannot change attachment target. 3067 */ 3068 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 3069 dst_prog->type == BPF_PROG_TYPE_TRACING) { 3070 prog->aux->attach_tracing_prog = true; 3071 } 3072 3073 /* find program type: socket_filter vs tracing_filter */ 3074 err = find_prog_type(type, prog); 3075 if (err < 0) 3076 goto free_prog; 3077 3078 prog->aux->load_time = ktime_get_boottime_ns(); 3079 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 3080 sizeof(attr->prog_name)); 3081 if (err < 0) 3082 goto free_prog; 3083 3084 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel); 3085 if (err) 3086 goto free_prog_sec; 3087 3088 /* run eBPF verifier */ 3089 err = bpf_check(&prog, attr, uattr, uattr_size); 3090 if (err < 0) 3091 goto free_used_maps; 3092 3093 prog = bpf_prog_select_runtime(prog, &err); 3094 if (err < 0) 3095 goto free_used_maps; 3096 3097 err = bpf_prog_mark_insn_arrays_ready(prog); 3098 if (err < 0) 3099 goto free_used_maps; 3100 3101 err = bpf_prog_alloc_id(prog); 3102 if (err) 3103 goto free_used_maps; 3104 3105 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 3106 * effectively publicly exposed. However, retrieving via 3107 * bpf_prog_get_fd_by_id() will take another reference, 3108 * therefore it cannot be gone underneath us. 3109 * 3110 * Only for the time /after/ successful bpf_prog_new_fd() 3111 * and before returning to userspace, we might just hold 3112 * one reference and any parallel close on that fd could 3113 * rip everything out. Hence, below notifications must 3114 * happen before bpf_prog_new_fd(). 3115 * 3116 * Also, any failure handling from this point onwards must 3117 * be using bpf_prog_put() given the program is exposed. 3118 */ 3119 bpf_prog_kallsyms_add(prog); 3120 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 3121 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 3122 3123 err = bpf_prog_new_fd(prog); 3124 if (err < 0) 3125 bpf_prog_put(prog); 3126 return err; 3127 3128 free_used_maps: 3129 /* In case we have subprogs, we need to wait for a grace 3130 * period before we can tear down JIT memory since symbols 3131 * are already exposed under kallsyms. 3132 */ 3133 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 3134 return err; 3135 3136 free_prog_sec: 3137 security_bpf_prog_free(prog); 3138 free_prog: 3139 free_uid(prog->aux->user); 3140 if (prog->aux->attach_btf) 3141 btf_put(prog->aux->attach_btf); 3142 bpf_prog_free(prog); 3143 put_token: 3144 bpf_token_put(token); 3145 return err; 3146 } 3147 3148 #define BPF_OBJ_LAST_FIELD path_fd 3149 3150 static int bpf_obj_pin(const union bpf_attr *attr) 3151 { 3152 int path_fd; 3153 3154 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3155 return -EINVAL; 3156 3157 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3158 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3159 return -EINVAL; 3160 3161 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3162 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3163 u64_to_user_ptr(attr->pathname)); 3164 } 3165 3166 static int bpf_obj_get(const union bpf_attr *attr) 3167 { 3168 int path_fd; 3169 3170 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3171 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3172 return -EINVAL; 3173 3174 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3175 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3176 return -EINVAL; 3177 3178 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3179 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3180 attr->file_flags); 3181 } 3182 3183 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3184 * "sleepable" semantics, which normally would mean that BPF link's attach 3185 * hook can dereference link or link's underlying program for some time after 3186 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3187 * BPF program itself can be non-sleepable, yet, because it's transitively 3188 * reachable through BPF link, its freeing has to be delayed until after RCU 3189 * Tasks Trace GP. 3190 */ 3191 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3192 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3193 enum bpf_attach_type attach_type, bool sleepable) 3194 { 3195 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3196 atomic64_set(&link->refcnt, 1); 3197 link->type = type; 3198 link->sleepable = sleepable; 3199 link->id = 0; 3200 link->ops = ops; 3201 link->prog = prog; 3202 link->attach_type = attach_type; 3203 } 3204 3205 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3206 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3207 enum bpf_attach_type attach_type) 3208 { 3209 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); 3210 } 3211 3212 static void bpf_link_free_id(int id) 3213 { 3214 if (!id) 3215 return; 3216 3217 spin_lock_bh(&link_idr_lock); 3218 idr_remove(&link_idr, id); 3219 spin_unlock_bh(&link_idr_lock); 3220 } 3221 3222 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3223 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3224 * anon_inode's release() call. This helper marks bpf_link as 3225 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3226 * is not decremented, it's the responsibility of a calling code that failed 3227 * to complete bpf_link initialization. 3228 * This helper eventually calls link's dealloc callback, but does not call 3229 * link's release callback. 3230 */ 3231 void bpf_link_cleanup(struct bpf_link_primer *primer) 3232 { 3233 primer->link->prog = NULL; 3234 bpf_link_free_id(primer->id); 3235 fput(primer->file); 3236 put_unused_fd(primer->fd); 3237 } 3238 3239 void bpf_link_inc(struct bpf_link *link) 3240 { 3241 atomic64_inc(&link->refcnt); 3242 } 3243 3244 static void bpf_link_dealloc(struct bpf_link *link) 3245 { 3246 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3247 if (link->prog) 3248 bpf_prog_put(link->prog); 3249 3250 /* free bpf_link and its containing memory */ 3251 if (link->ops->dealloc_deferred) 3252 link->ops->dealloc_deferred(link); 3253 else 3254 link->ops->dealloc(link); 3255 } 3256 3257 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3258 { 3259 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3260 3261 bpf_link_dealloc(link); 3262 } 3263 3264 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu) 3265 { 3266 if (rcu_trace_implies_rcu_gp()) 3267 bpf_link_defer_dealloc_rcu_gp(rcu); 3268 else 3269 call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp); 3270 } 3271 3272 /* bpf_link_free is guaranteed to be called from process context */ 3273 static void bpf_link_free(struct bpf_link *link) 3274 { 3275 const struct bpf_link_ops *ops = link->ops; 3276 3277 bpf_link_free_id(link->id); 3278 /* detach BPF program, clean up used resources */ 3279 if (link->prog) 3280 ops->release(link); 3281 if (ops->dealloc_deferred) { 3282 /* Schedule BPF link deallocation, which will only then 3283 * trigger putting BPF program refcount. 3284 * If underlying BPF program is sleepable or BPF link's target 3285 * attach hookpoint is sleepable or otherwise requires RCU GPs 3286 * to ensure link and its underlying BPF program is not 3287 * reachable anymore, we need to first wait for RCU tasks 3288 * trace sync, and then go through "classic" RCU grace period 3289 */ 3290 if (link->sleepable || (link->prog && link->prog->sleepable)) 3291 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp); 3292 else 3293 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3294 } else if (ops->dealloc) { 3295 bpf_link_dealloc(link); 3296 } 3297 } 3298 3299 static void bpf_link_put_deferred(struct work_struct *work) 3300 { 3301 struct bpf_link *link = container_of(work, struct bpf_link, work); 3302 3303 bpf_link_free(link); 3304 } 3305 3306 /* bpf_link_put might be called from atomic context. It needs to be called 3307 * from sleepable context in order to acquire sleeping locks during the process. 3308 */ 3309 void bpf_link_put(struct bpf_link *link) 3310 { 3311 if (!atomic64_dec_and_test(&link->refcnt)) 3312 return; 3313 3314 INIT_WORK(&link->work, bpf_link_put_deferred); 3315 schedule_work(&link->work); 3316 } 3317 EXPORT_SYMBOL(bpf_link_put); 3318 3319 static void bpf_link_put_direct(struct bpf_link *link) 3320 { 3321 if (!atomic64_dec_and_test(&link->refcnt)) 3322 return; 3323 bpf_link_free(link); 3324 } 3325 3326 static int bpf_link_release(struct inode *inode, struct file *filp) 3327 { 3328 struct bpf_link *link = filp->private_data; 3329 3330 bpf_link_put_direct(link); 3331 return 0; 3332 } 3333 3334 #ifdef CONFIG_PROC_FS 3335 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3336 #define BPF_MAP_TYPE(_id, _ops) 3337 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3338 static const char *bpf_link_type_strs[] = { 3339 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3340 #include <linux/bpf_types.h> 3341 }; 3342 #undef BPF_PROG_TYPE 3343 #undef BPF_MAP_TYPE 3344 #undef BPF_LINK_TYPE 3345 3346 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3347 { 3348 const struct bpf_link *link = filp->private_data; 3349 const struct bpf_prog *prog = link->prog; 3350 enum bpf_link_type type = link->type; 3351 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3352 3353 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3354 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) 3355 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? 3356 "kretprobe_multi" : "kprobe_multi"); 3357 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) 3358 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ? 3359 "uretprobe_multi" : "uprobe_multi"); 3360 else 3361 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3362 } else { 3363 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3364 seq_printf(m, "link_type:\t<%u>\n", type); 3365 } 3366 seq_printf(m, "link_id:\t%u\n", link->id); 3367 3368 if (prog) { 3369 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3370 seq_printf(m, 3371 "prog_tag:\t%s\n" 3372 "prog_id:\t%u\n", 3373 prog_tag, 3374 prog->aux->id); 3375 } 3376 if (link->ops->show_fdinfo) 3377 link->ops->show_fdinfo(link, m); 3378 } 3379 #endif 3380 3381 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3382 { 3383 struct bpf_link *link = file->private_data; 3384 3385 return link->ops->poll(file, pts); 3386 } 3387 3388 static const struct file_operations bpf_link_fops = { 3389 #ifdef CONFIG_PROC_FS 3390 .show_fdinfo = bpf_link_show_fdinfo, 3391 #endif 3392 .release = bpf_link_release, 3393 .read = bpf_dummy_read, 3394 .write = bpf_dummy_write, 3395 }; 3396 3397 static const struct file_operations bpf_link_fops_poll = { 3398 #ifdef CONFIG_PROC_FS 3399 .show_fdinfo = bpf_link_show_fdinfo, 3400 #endif 3401 .release = bpf_link_release, 3402 .read = bpf_dummy_read, 3403 .write = bpf_dummy_write, 3404 .poll = bpf_link_poll, 3405 }; 3406 3407 static int bpf_link_alloc_id(struct bpf_link *link) 3408 { 3409 int id; 3410 3411 idr_preload(GFP_KERNEL); 3412 spin_lock_bh(&link_idr_lock); 3413 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3414 spin_unlock_bh(&link_idr_lock); 3415 idr_preload_end(); 3416 3417 return id; 3418 } 3419 3420 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3421 * reserving unused FD and allocating ID from link_idr. This is to be paired 3422 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3423 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3424 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3425 * transient state is passed around in struct bpf_link_primer. 3426 * This is preferred way to create and initialize bpf_link, especially when 3427 * there are complicated and expensive operations in between creating bpf_link 3428 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3429 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3430 * expensive (and potentially failing) roll back operations in a rare case 3431 * that file, FD, or ID can't be allocated. 3432 */ 3433 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3434 { 3435 struct file *file; 3436 int fd, id; 3437 3438 fd = get_unused_fd_flags(O_CLOEXEC); 3439 if (fd < 0) 3440 return fd; 3441 3442 3443 id = bpf_link_alloc_id(link); 3444 if (id < 0) { 3445 put_unused_fd(fd); 3446 return id; 3447 } 3448 3449 file = anon_inode_getfile("bpf_link", 3450 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3451 link, O_CLOEXEC); 3452 if (IS_ERR(file)) { 3453 bpf_link_free_id(id); 3454 put_unused_fd(fd); 3455 return PTR_ERR(file); 3456 } 3457 3458 primer->link = link; 3459 primer->file = file; 3460 primer->fd = fd; 3461 primer->id = id; 3462 return 0; 3463 } 3464 3465 int bpf_link_settle(struct bpf_link_primer *primer) 3466 { 3467 /* make bpf_link fetchable by ID */ 3468 spin_lock_bh(&link_idr_lock); 3469 primer->link->id = primer->id; 3470 spin_unlock_bh(&link_idr_lock); 3471 /* make bpf_link fetchable by FD */ 3472 fd_install(primer->fd, primer->file); 3473 /* pass through installed FD */ 3474 return primer->fd; 3475 } 3476 3477 int bpf_link_new_fd(struct bpf_link *link) 3478 { 3479 return anon_inode_getfd("bpf-link", 3480 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3481 link, O_CLOEXEC); 3482 } 3483 3484 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3485 { 3486 CLASS(fd, f)(ufd); 3487 struct bpf_link *link; 3488 3489 if (fd_empty(f)) 3490 return ERR_PTR(-EBADF); 3491 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3492 return ERR_PTR(-EINVAL); 3493 3494 link = fd_file(f)->private_data; 3495 bpf_link_inc(link); 3496 return link; 3497 } 3498 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); 3499 3500 static void bpf_tracing_link_release(struct bpf_link *link) 3501 { 3502 struct bpf_tracing_link *tr_link = 3503 container_of(link, struct bpf_tracing_link, link.link); 3504 3505 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3506 tr_link->trampoline, 3507 tr_link->tgt_prog)); 3508 3509 bpf_trampoline_put(tr_link->trampoline); 3510 3511 /* tgt_prog is NULL if target is a kernel function */ 3512 if (tr_link->tgt_prog) 3513 bpf_prog_put(tr_link->tgt_prog); 3514 } 3515 3516 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3517 { 3518 struct bpf_tracing_link *tr_link = 3519 container_of(link, struct bpf_tracing_link, link.link); 3520 3521 kfree(tr_link); 3522 } 3523 3524 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3525 struct seq_file *seq) 3526 { 3527 struct bpf_tracing_link *tr_link = 3528 container_of(link, struct bpf_tracing_link, link.link); 3529 u32 target_btf_id, target_obj_id; 3530 3531 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3532 &target_obj_id, &target_btf_id); 3533 seq_printf(seq, 3534 "attach_type:\t%d\n" 3535 "target_obj_id:\t%u\n" 3536 "target_btf_id:\t%u\n" 3537 "cookie:\t%llu\n", 3538 link->attach_type, 3539 target_obj_id, 3540 target_btf_id, 3541 tr_link->link.cookie); 3542 } 3543 3544 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3545 struct bpf_link_info *info) 3546 { 3547 struct bpf_tracing_link *tr_link = 3548 container_of(link, struct bpf_tracing_link, link.link); 3549 3550 info->tracing.attach_type = link->attach_type; 3551 info->tracing.cookie = tr_link->link.cookie; 3552 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3553 &info->tracing.target_obj_id, 3554 &info->tracing.target_btf_id); 3555 3556 return 0; 3557 } 3558 3559 static const struct bpf_link_ops bpf_tracing_link_lops = { 3560 .release = bpf_tracing_link_release, 3561 .dealloc = bpf_tracing_link_dealloc, 3562 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3563 .fill_link_info = bpf_tracing_link_fill_link_info, 3564 }; 3565 3566 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3567 int tgt_prog_fd, 3568 u32 btf_id, 3569 u64 bpf_cookie, 3570 enum bpf_attach_type attach_type) 3571 { 3572 struct bpf_link_primer link_primer; 3573 struct bpf_prog *tgt_prog = NULL; 3574 struct bpf_trampoline *tr = NULL; 3575 struct bpf_tracing_link *link; 3576 u64 key = 0; 3577 int err; 3578 3579 switch (prog->type) { 3580 case BPF_PROG_TYPE_TRACING: 3581 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3582 prog->expected_attach_type != BPF_TRACE_FEXIT && 3583 prog->expected_attach_type != BPF_TRACE_FSESSION && 3584 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3585 err = -EINVAL; 3586 goto out_put_prog; 3587 } 3588 break; 3589 case BPF_PROG_TYPE_EXT: 3590 if (prog->expected_attach_type != 0) { 3591 err = -EINVAL; 3592 goto out_put_prog; 3593 } 3594 break; 3595 case BPF_PROG_TYPE_LSM: 3596 if (prog->expected_attach_type != BPF_LSM_MAC) { 3597 err = -EINVAL; 3598 goto out_put_prog; 3599 } 3600 break; 3601 default: 3602 err = -EINVAL; 3603 goto out_put_prog; 3604 } 3605 3606 if (!!tgt_prog_fd != !!btf_id) { 3607 err = -EINVAL; 3608 goto out_put_prog; 3609 } 3610 3611 if (tgt_prog_fd) { 3612 /* 3613 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3614 * part would be changed to implement the same for 3615 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3616 * attach_tracing_prog flag is set. 3617 */ 3618 if (prog->type != BPF_PROG_TYPE_EXT) { 3619 err = -EINVAL; 3620 goto out_put_prog; 3621 } 3622 3623 tgt_prog = bpf_prog_get(tgt_prog_fd); 3624 if (IS_ERR(tgt_prog)) { 3625 err = PTR_ERR(tgt_prog); 3626 tgt_prog = NULL; 3627 goto out_put_prog; 3628 } 3629 3630 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3631 } 3632 3633 if (prog->expected_attach_type == BPF_TRACE_FSESSION) { 3634 struct bpf_fsession_link *fslink; 3635 3636 fslink = kzalloc(sizeof(*fslink), GFP_USER); 3637 if (fslink) { 3638 bpf_link_init(&fslink->fexit.link, BPF_LINK_TYPE_TRACING, 3639 &bpf_tracing_link_lops, prog, attach_type); 3640 fslink->fexit.cookie = bpf_cookie; 3641 link = &fslink->link; 3642 } else { 3643 link = NULL; 3644 } 3645 } else { 3646 link = kzalloc(sizeof(*link), GFP_USER); 3647 } 3648 if (!link) { 3649 err = -ENOMEM; 3650 goto out_put_prog; 3651 } 3652 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3653 &bpf_tracing_link_lops, prog, attach_type); 3654 3655 link->link.cookie = bpf_cookie; 3656 3657 mutex_lock(&prog->aux->dst_mutex); 3658 3659 /* There are a few possible cases here: 3660 * 3661 * - if prog->aux->dst_trampoline is set, the program was just loaded 3662 * and not yet attached to anything, so we can use the values stored 3663 * in prog->aux 3664 * 3665 * - if prog->aux->dst_trampoline is NULL, the program has already been 3666 * attached to a target and its initial target was cleared (below) 3667 * 3668 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3669 * target_btf_id using the link_create API. 3670 * 3671 * - if tgt_prog == NULL when this function was called using the old 3672 * raw_tracepoint_open API, and we need a target from prog->aux 3673 * 3674 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3675 * was detached and is going for re-attachment. 3676 * 3677 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3678 * are NULL, then program was already attached and user did not provide 3679 * tgt_prog_fd so we have no way to find out or create trampoline 3680 */ 3681 if (!prog->aux->dst_trampoline && !tgt_prog) { 3682 /* 3683 * Allow re-attach for TRACING and LSM programs. If it's 3684 * currently linked, bpf_trampoline_link_prog will fail. 3685 * EXT programs need to specify tgt_prog_fd, so they 3686 * re-attach in separate code path. 3687 */ 3688 if (prog->type != BPF_PROG_TYPE_TRACING && 3689 prog->type != BPF_PROG_TYPE_LSM) { 3690 err = -EINVAL; 3691 goto out_unlock; 3692 } 3693 /* We can allow re-attach only if we have valid attach_btf. */ 3694 if (!prog->aux->attach_btf) { 3695 err = -EINVAL; 3696 goto out_unlock; 3697 } 3698 btf_id = prog->aux->attach_btf_id; 3699 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3700 } 3701 3702 if (!prog->aux->dst_trampoline || 3703 (key && key != prog->aux->dst_trampoline->key)) { 3704 /* If there is no saved target, or the specified target is 3705 * different from the destination specified at load time, we 3706 * need a new trampoline and a check for compatibility 3707 */ 3708 struct bpf_attach_target_info tgt_info = {}; 3709 3710 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3711 &tgt_info); 3712 if (err) 3713 goto out_unlock; 3714 3715 if (tgt_info.tgt_mod) { 3716 module_put(prog->aux->mod); 3717 prog->aux->mod = tgt_info.tgt_mod; 3718 } 3719 3720 tr = bpf_trampoline_get(key, &tgt_info); 3721 if (!tr) { 3722 err = -ENOMEM; 3723 goto out_unlock; 3724 } 3725 } else { 3726 /* The caller didn't specify a target, or the target was the 3727 * same as the destination supplied during program load. This 3728 * means we can reuse the trampoline and reference from program 3729 * load time, and there is no need to allocate a new one. This 3730 * can only happen once for any program, as the saved values in 3731 * prog->aux are cleared below. 3732 */ 3733 tr = prog->aux->dst_trampoline; 3734 tgt_prog = prog->aux->dst_prog; 3735 } 3736 3737 err = bpf_link_prime(&link->link.link, &link_primer); 3738 if (err) 3739 goto out_unlock; 3740 3741 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog); 3742 if (err) { 3743 bpf_link_cleanup(&link_primer); 3744 link = NULL; 3745 goto out_unlock; 3746 } 3747 3748 link->tgt_prog = tgt_prog; 3749 link->trampoline = tr; 3750 3751 /* Always clear the trampoline and target prog from prog->aux to make 3752 * sure the original attach destination is not kept alive after a 3753 * program is (re-)attached to another target. 3754 */ 3755 if (prog->aux->dst_prog && 3756 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3757 /* got extra prog ref from syscall, or attaching to different prog */ 3758 bpf_prog_put(prog->aux->dst_prog); 3759 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3760 /* we allocated a new trampoline, so free the old one */ 3761 bpf_trampoline_put(prog->aux->dst_trampoline); 3762 3763 prog->aux->dst_prog = NULL; 3764 prog->aux->dst_trampoline = NULL; 3765 mutex_unlock(&prog->aux->dst_mutex); 3766 3767 return bpf_link_settle(&link_primer); 3768 out_unlock: 3769 if (tr && tr != prog->aux->dst_trampoline) 3770 bpf_trampoline_put(tr); 3771 mutex_unlock(&prog->aux->dst_mutex); 3772 kfree(link); 3773 out_put_prog: 3774 if (tgt_prog_fd && tgt_prog) 3775 bpf_prog_put(tgt_prog); 3776 return err; 3777 } 3778 3779 static void bpf_raw_tp_link_release(struct bpf_link *link) 3780 { 3781 struct bpf_raw_tp_link *raw_tp = 3782 container_of(link, struct bpf_raw_tp_link, link); 3783 3784 bpf_probe_unregister(raw_tp->btp, raw_tp); 3785 bpf_put_raw_tracepoint(raw_tp->btp); 3786 } 3787 3788 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3789 { 3790 struct bpf_raw_tp_link *raw_tp = 3791 container_of(link, struct bpf_raw_tp_link, link); 3792 3793 kfree(raw_tp); 3794 } 3795 3796 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3797 struct seq_file *seq) 3798 { 3799 struct bpf_raw_tp_link *raw_tp_link = 3800 container_of(link, struct bpf_raw_tp_link, link); 3801 3802 seq_printf(seq, 3803 "tp_name:\t%s\n" 3804 "cookie:\t%llu\n", 3805 raw_tp_link->btp->tp->name, 3806 raw_tp_link->cookie); 3807 } 3808 3809 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3810 u32 len) 3811 { 3812 if (ulen >= len + 1) { 3813 if (copy_to_user(ubuf, buf, len + 1)) 3814 return -EFAULT; 3815 } else { 3816 char zero = '\0'; 3817 3818 if (copy_to_user(ubuf, buf, ulen - 1)) 3819 return -EFAULT; 3820 if (put_user(zero, ubuf + ulen - 1)) 3821 return -EFAULT; 3822 return -ENOSPC; 3823 } 3824 3825 return 0; 3826 } 3827 3828 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3829 struct bpf_link_info *info) 3830 { 3831 struct bpf_raw_tp_link *raw_tp_link = 3832 container_of(link, struct bpf_raw_tp_link, link); 3833 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3834 const char *tp_name = raw_tp_link->btp->tp->name; 3835 u32 ulen = info->raw_tracepoint.tp_name_len; 3836 size_t tp_len = strlen(tp_name); 3837 3838 if (!ulen ^ !ubuf) 3839 return -EINVAL; 3840 3841 info->raw_tracepoint.tp_name_len = tp_len + 1; 3842 info->raw_tracepoint.cookie = raw_tp_link->cookie; 3843 3844 if (!ubuf) 3845 return 0; 3846 3847 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3848 } 3849 3850 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3851 .release = bpf_raw_tp_link_release, 3852 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3853 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3854 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3855 }; 3856 3857 #ifdef CONFIG_PERF_EVENTS 3858 struct bpf_perf_link { 3859 struct bpf_link link; 3860 struct file *perf_file; 3861 }; 3862 3863 static void bpf_perf_link_release(struct bpf_link *link) 3864 { 3865 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3866 struct perf_event *event = perf_link->perf_file->private_data; 3867 3868 perf_event_free_bpf_prog(event); 3869 fput(perf_link->perf_file); 3870 } 3871 3872 static void bpf_perf_link_dealloc(struct bpf_link *link) 3873 { 3874 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3875 3876 kfree(perf_link); 3877 } 3878 3879 static int bpf_perf_link_fill_common(const struct perf_event *event, 3880 char __user *uname, u32 *ulenp, 3881 u64 *probe_offset, u64 *probe_addr, 3882 u32 *fd_type, unsigned long *missed) 3883 { 3884 const char *buf; 3885 u32 prog_id, ulen; 3886 size_t len; 3887 int err; 3888 3889 ulen = *ulenp; 3890 if (!ulen ^ !uname) 3891 return -EINVAL; 3892 3893 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3894 probe_offset, probe_addr, missed); 3895 if (err) 3896 return err; 3897 3898 if (buf) { 3899 len = strlen(buf); 3900 *ulenp = len + 1; 3901 } else { 3902 *ulenp = 1; 3903 } 3904 if (!uname) 3905 return 0; 3906 3907 if (buf) { 3908 err = bpf_copy_to_user(uname, buf, ulen, len); 3909 if (err) 3910 return err; 3911 } else { 3912 char zero = '\0'; 3913 3914 if (put_user(zero, uname)) 3915 return -EFAULT; 3916 } 3917 return 0; 3918 } 3919 3920 #ifdef CONFIG_KPROBE_EVENTS 3921 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 3922 struct bpf_link_info *info) 3923 { 3924 unsigned long missed; 3925 char __user *uname; 3926 u64 addr, offset; 3927 u32 ulen, type; 3928 int err; 3929 3930 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 3931 ulen = info->perf_event.kprobe.name_len; 3932 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 3933 &type, &missed); 3934 if (err) 3935 return err; 3936 if (type == BPF_FD_TYPE_KRETPROBE) 3937 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 3938 else 3939 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 3940 info->perf_event.kprobe.name_len = ulen; 3941 info->perf_event.kprobe.offset = offset; 3942 info->perf_event.kprobe.missed = missed; 3943 if (!kallsyms_show_value(current_cred())) 3944 addr = 0; 3945 info->perf_event.kprobe.addr = addr; 3946 info->perf_event.kprobe.cookie = event->bpf_cookie; 3947 return 0; 3948 } 3949 3950 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, 3951 struct seq_file *seq) 3952 { 3953 const char *name; 3954 int err; 3955 u32 prog_id, type; 3956 u64 offset, addr; 3957 unsigned long missed; 3958 3959 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 3960 &offset, &addr, &missed); 3961 if (err) 3962 return; 3963 3964 seq_printf(seq, 3965 "name:\t%s\n" 3966 "offset:\t%#llx\n" 3967 "missed:\t%lu\n" 3968 "addr:\t%#llx\n" 3969 "event_type:\t%s\n" 3970 "cookie:\t%llu\n", 3971 name, offset, missed, addr, 3972 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", 3973 event->bpf_cookie); 3974 } 3975 #endif 3976 3977 #ifdef CONFIG_UPROBE_EVENTS 3978 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 3979 struct bpf_link_info *info) 3980 { 3981 u64 ref_ctr_offset, offset; 3982 char __user *uname; 3983 u32 ulen, type; 3984 int err; 3985 3986 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 3987 ulen = info->perf_event.uprobe.name_len; 3988 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, 3989 &type, NULL); 3990 if (err) 3991 return err; 3992 3993 if (type == BPF_FD_TYPE_URETPROBE) 3994 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 3995 else 3996 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 3997 info->perf_event.uprobe.name_len = ulen; 3998 info->perf_event.uprobe.offset = offset; 3999 info->perf_event.uprobe.cookie = event->bpf_cookie; 4000 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; 4001 return 0; 4002 } 4003 4004 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, 4005 struct seq_file *seq) 4006 { 4007 const char *name; 4008 int err; 4009 u32 prog_id, type; 4010 u64 offset, ref_ctr_offset; 4011 unsigned long missed; 4012 4013 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4014 &offset, &ref_ctr_offset, &missed); 4015 if (err) 4016 return; 4017 4018 seq_printf(seq, 4019 "name:\t%s\n" 4020 "offset:\t%#llx\n" 4021 "ref_ctr_offset:\t%#llx\n" 4022 "event_type:\t%s\n" 4023 "cookie:\t%llu\n", 4024 name, offset, ref_ctr_offset, 4025 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", 4026 event->bpf_cookie); 4027 } 4028 #endif 4029 4030 static int bpf_perf_link_fill_probe(const struct perf_event *event, 4031 struct bpf_link_info *info) 4032 { 4033 #ifdef CONFIG_KPROBE_EVENTS 4034 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4035 return bpf_perf_link_fill_kprobe(event, info); 4036 #endif 4037 #ifdef CONFIG_UPROBE_EVENTS 4038 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4039 return bpf_perf_link_fill_uprobe(event, info); 4040 #endif 4041 return -EOPNOTSUPP; 4042 } 4043 4044 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 4045 struct bpf_link_info *info) 4046 { 4047 char __user *uname; 4048 u32 ulen; 4049 int err; 4050 4051 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 4052 ulen = info->perf_event.tracepoint.name_len; 4053 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 4054 if (err) 4055 return err; 4056 4057 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 4058 info->perf_event.tracepoint.name_len = ulen; 4059 info->perf_event.tracepoint.cookie = event->bpf_cookie; 4060 return 0; 4061 } 4062 4063 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 4064 struct bpf_link_info *info) 4065 { 4066 info->perf_event.event.type = event->attr.type; 4067 info->perf_event.event.config = event->attr.config; 4068 info->perf_event.event.cookie = event->bpf_cookie; 4069 info->perf_event.type = BPF_PERF_EVENT_EVENT; 4070 return 0; 4071 } 4072 4073 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 4074 struct bpf_link_info *info) 4075 { 4076 struct bpf_perf_link *perf_link; 4077 const struct perf_event *event; 4078 4079 perf_link = container_of(link, struct bpf_perf_link, link); 4080 event = perf_get_event(perf_link->perf_file); 4081 if (IS_ERR(event)) 4082 return PTR_ERR(event); 4083 4084 switch (event->prog->type) { 4085 case BPF_PROG_TYPE_PERF_EVENT: 4086 return bpf_perf_link_fill_perf_event(event, info); 4087 case BPF_PROG_TYPE_TRACEPOINT: 4088 return bpf_perf_link_fill_tracepoint(event, info); 4089 case BPF_PROG_TYPE_KPROBE: 4090 return bpf_perf_link_fill_probe(event, info); 4091 default: 4092 return -EOPNOTSUPP; 4093 } 4094 } 4095 4096 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, 4097 struct seq_file *seq) 4098 { 4099 seq_printf(seq, 4100 "type:\t%u\n" 4101 "config:\t%llu\n" 4102 "event_type:\t%s\n" 4103 "cookie:\t%llu\n", 4104 event->attr.type, event->attr.config, 4105 "event", event->bpf_cookie); 4106 } 4107 4108 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, 4109 struct seq_file *seq) 4110 { 4111 int err; 4112 const char *name; 4113 u32 prog_id; 4114 4115 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, 4116 NULL, NULL); 4117 if (err) 4118 return; 4119 4120 seq_printf(seq, 4121 "tp_name:\t%s\n" 4122 "event_type:\t%s\n" 4123 "cookie:\t%llu\n", 4124 name, "tracepoint", event->bpf_cookie); 4125 } 4126 4127 static void bpf_probe_link_show_fdinfo(const struct perf_event *event, 4128 struct seq_file *seq) 4129 { 4130 #ifdef CONFIG_KPROBE_EVENTS 4131 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4132 return bpf_perf_link_fdinfo_kprobe(event, seq); 4133 #endif 4134 4135 #ifdef CONFIG_UPROBE_EVENTS 4136 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4137 return bpf_perf_link_fdinfo_uprobe(event, seq); 4138 #endif 4139 } 4140 4141 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, 4142 struct seq_file *seq) 4143 { 4144 struct bpf_perf_link *perf_link; 4145 const struct perf_event *event; 4146 4147 perf_link = container_of(link, struct bpf_perf_link, link); 4148 event = perf_get_event(perf_link->perf_file); 4149 if (IS_ERR(event)) 4150 return; 4151 4152 switch (event->prog->type) { 4153 case BPF_PROG_TYPE_PERF_EVENT: 4154 return bpf_perf_event_link_show_fdinfo(event, seq); 4155 case BPF_PROG_TYPE_TRACEPOINT: 4156 return bpf_tracepoint_link_show_fdinfo(event, seq); 4157 case BPF_PROG_TYPE_KPROBE: 4158 return bpf_probe_link_show_fdinfo(event, seq); 4159 default: 4160 return; 4161 } 4162 } 4163 4164 static const struct bpf_link_ops bpf_perf_link_lops = { 4165 .release = bpf_perf_link_release, 4166 .dealloc = bpf_perf_link_dealloc, 4167 .fill_link_info = bpf_perf_link_fill_link_info, 4168 .show_fdinfo = bpf_perf_link_show_fdinfo, 4169 }; 4170 4171 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4172 { 4173 struct bpf_link_primer link_primer; 4174 struct bpf_perf_link *link; 4175 struct perf_event *event; 4176 struct file *perf_file; 4177 int err; 4178 4179 if (attr->link_create.flags) 4180 return -EINVAL; 4181 4182 perf_file = perf_event_get(attr->link_create.target_fd); 4183 if (IS_ERR(perf_file)) 4184 return PTR_ERR(perf_file); 4185 4186 link = kzalloc(sizeof(*link), GFP_USER); 4187 if (!link) { 4188 err = -ENOMEM; 4189 goto out_put_file; 4190 } 4191 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, 4192 attr->link_create.attach_type); 4193 link->perf_file = perf_file; 4194 4195 err = bpf_link_prime(&link->link, &link_primer); 4196 if (err) { 4197 kfree(link); 4198 goto out_put_file; 4199 } 4200 4201 event = perf_file->private_data; 4202 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 4203 if (err) { 4204 bpf_link_cleanup(&link_primer); 4205 goto out_put_file; 4206 } 4207 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 4208 bpf_prog_inc(prog); 4209 4210 return bpf_link_settle(&link_primer); 4211 4212 out_put_file: 4213 fput(perf_file); 4214 return err; 4215 } 4216 #else 4217 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4218 { 4219 return -EOPNOTSUPP; 4220 } 4221 #endif /* CONFIG_PERF_EVENTS */ 4222 4223 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 4224 const char __user *user_tp_name, u64 cookie, 4225 enum bpf_attach_type attach_type) 4226 { 4227 struct bpf_link_primer link_primer; 4228 struct bpf_raw_tp_link *link; 4229 struct bpf_raw_event_map *btp; 4230 const char *tp_name; 4231 char buf[128]; 4232 int err; 4233 4234 switch (prog->type) { 4235 case BPF_PROG_TYPE_TRACING: 4236 case BPF_PROG_TYPE_EXT: 4237 case BPF_PROG_TYPE_LSM: 4238 if (user_tp_name) 4239 /* The attach point for this category of programs 4240 * should be specified via btf_id during program load. 4241 */ 4242 return -EINVAL; 4243 if (prog->type == BPF_PROG_TYPE_TRACING && 4244 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 4245 tp_name = prog->aux->attach_func_name; 4246 break; 4247 } 4248 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); 4249 case BPF_PROG_TYPE_RAW_TRACEPOINT: 4250 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 4251 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 4252 return -EFAULT; 4253 buf[sizeof(buf) - 1] = 0; 4254 tp_name = buf; 4255 break; 4256 default: 4257 return -EINVAL; 4258 } 4259 4260 btp = bpf_get_raw_tracepoint(tp_name); 4261 if (!btp) 4262 return -ENOENT; 4263 4264 link = kzalloc(sizeof(*link), GFP_USER); 4265 if (!link) { 4266 err = -ENOMEM; 4267 goto out_put_btp; 4268 } 4269 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 4270 &bpf_raw_tp_link_lops, prog, attach_type, 4271 tracepoint_is_faultable(btp->tp)); 4272 link->btp = btp; 4273 link->cookie = cookie; 4274 4275 err = bpf_link_prime(&link->link, &link_primer); 4276 if (err) { 4277 kfree(link); 4278 goto out_put_btp; 4279 } 4280 4281 err = bpf_probe_register(link->btp, link); 4282 if (err) { 4283 bpf_link_cleanup(&link_primer); 4284 goto out_put_btp; 4285 } 4286 4287 return bpf_link_settle(&link_primer); 4288 4289 out_put_btp: 4290 bpf_put_raw_tracepoint(btp); 4291 return err; 4292 } 4293 4294 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 4295 4296 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4297 { 4298 struct bpf_prog *prog; 4299 void __user *tp_name; 4300 __u64 cookie; 4301 int fd; 4302 4303 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4304 return -EINVAL; 4305 4306 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4307 if (IS_ERR(prog)) 4308 return PTR_ERR(prog); 4309 4310 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4311 cookie = attr->raw_tracepoint.cookie; 4312 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); 4313 if (fd < 0) 4314 bpf_prog_put(prog); 4315 return fd; 4316 } 4317 4318 static enum bpf_prog_type 4319 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4320 { 4321 switch (attach_type) { 4322 case BPF_CGROUP_INET_INGRESS: 4323 case BPF_CGROUP_INET_EGRESS: 4324 return BPF_PROG_TYPE_CGROUP_SKB; 4325 case BPF_CGROUP_INET_SOCK_CREATE: 4326 case BPF_CGROUP_INET_SOCK_RELEASE: 4327 case BPF_CGROUP_INET4_POST_BIND: 4328 case BPF_CGROUP_INET6_POST_BIND: 4329 return BPF_PROG_TYPE_CGROUP_SOCK; 4330 case BPF_CGROUP_INET4_BIND: 4331 case BPF_CGROUP_INET6_BIND: 4332 case BPF_CGROUP_INET4_CONNECT: 4333 case BPF_CGROUP_INET6_CONNECT: 4334 case BPF_CGROUP_UNIX_CONNECT: 4335 case BPF_CGROUP_INET4_GETPEERNAME: 4336 case BPF_CGROUP_INET6_GETPEERNAME: 4337 case BPF_CGROUP_UNIX_GETPEERNAME: 4338 case BPF_CGROUP_INET4_GETSOCKNAME: 4339 case BPF_CGROUP_INET6_GETSOCKNAME: 4340 case BPF_CGROUP_UNIX_GETSOCKNAME: 4341 case BPF_CGROUP_UDP4_SENDMSG: 4342 case BPF_CGROUP_UDP6_SENDMSG: 4343 case BPF_CGROUP_UNIX_SENDMSG: 4344 case BPF_CGROUP_UDP4_RECVMSG: 4345 case BPF_CGROUP_UDP6_RECVMSG: 4346 case BPF_CGROUP_UNIX_RECVMSG: 4347 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4348 case BPF_CGROUP_SOCK_OPS: 4349 return BPF_PROG_TYPE_SOCK_OPS; 4350 case BPF_CGROUP_DEVICE: 4351 return BPF_PROG_TYPE_CGROUP_DEVICE; 4352 case BPF_SK_MSG_VERDICT: 4353 return BPF_PROG_TYPE_SK_MSG; 4354 case BPF_SK_SKB_STREAM_PARSER: 4355 case BPF_SK_SKB_STREAM_VERDICT: 4356 case BPF_SK_SKB_VERDICT: 4357 return BPF_PROG_TYPE_SK_SKB; 4358 case BPF_LIRC_MODE2: 4359 return BPF_PROG_TYPE_LIRC_MODE2; 4360 case BPF_FLOW_DISSECTOR: 4361 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4362 case BPF_CGROUP_SYSCTL: 4363 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4364 case BPF_CGROUP_GETSOCKOPT: 4365 case BPF_CGROUP_SETSOCKOPT: 4366 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4367 case BPF_TRACE_ITER: 4368 case BPF_TRACE_RAW_TP: 4369 case BPF_TRACE_FENTRY: 4370 case BPF_TRACE_FEXIT: 4371 case BPF_TRACE_FSESSION: 4372 case BPF_MODIFY_RETURN: 4373 return BPF_PROG_TYPE_TRACING; 4374 case BPF_LSM_MAC: 4375 return BPF_PROG_TYPE_LSM; 4376 case BPF_SK_LOOKUP: 4377 return BPF_PROG_TYPE_SK_LOOKUP; 4378 case BPF_XDP: 4379 return BPF_PROG_TYPE_XDP; 4380 case BPF_LSM_CGROUP: 4381 return BPF_PROG_TYPE_LSM; 4382 case BPF_TCX_INGRESS: 4383 case BPF_TCX_EGRESS: 4384 case BPF_NETKIT_PRIMARY: 4385 case BPF_NETKIT_PEER: 4386 return BPF_PROG_TYPE_SCHED_CLS; 4387 default: 4388 return BPF_PROG_TYPE_UNSPEC; 4389 } 4390 } 4391 4392 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4393 enum bpf_attach_type attach_type) 4394 { 4395 enum bpf_prog_type ptype; 4396 4397 switch (prog->type) { 4398 case BPF_PROG_TYPE_CGROUP_SOCK: 4399 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4400 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4401 case BPF_PROG_TYPE_SK_LOOKUP: 4402 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4403 case BPF_PROG_TYPE_CGROUP_SKB: 4404 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4405 /* cg-skb progs can be loaded by unpriv user. 4406 * check permissions at attach time. 4407 */ 4408 return -EPERM; 4409 4410 ptype = attach_type_to_prog_type(attach_type); 4411 if (prog->type != ptype) 4412 return -EINVAL; 4413 4414 return prog->enforce_expected_attach_type && 4415 prog->expected_attach_type != attach_type ? 4416 -EINVAL : 0; 4417 case BPF_PROG_TYPE_EXT: 4418 return 0; 4419 case BPF_PROG_TYPE_NETFILTER: 4420 if (attach_type != BPF_NETFILTER) 4421 return -EINVAL; 4422 return 0; 4423 case BPF_PROG_TYPE_PERF_EVENT: 4424 case BPF_PROG_TYPE_TRACEPOINT: 4425 if (attach_type != BPF_PERF_EVENT) 4426 return -EINVAL; 4427 return 0; 4428 case BPF_PROG_TYPE_KPROBE: 4429 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4430 attach_type != BPF_TRACE_KPROBE_MULTI) 4431 return -EINVAL; 4432 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4433 attach_type != BPF_TRACE_KPROBE_SESSION) 4434 return -EINVAL; 4435 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4436 attach_type != BPF_TRACE_UPROBE_MULTI) 4437 return -EINVAL; 4438 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4439 attach_type != BPF_TRACE_UPROBE_SESSION) 4440 return -EINVAL; 4441 if (attach_type != BPF_PERF_EVENT && 4442 attach_type != BPF_TRACE_KPROBE_MULTI && 4443 attach_type != BPF_TRACE_KPROBE_SESSION && 4444 attach_type != BPF_TRACE_UPROBE_MULTI && 4445 attach_type != BPF_TRACE_UPROBE_SESSION) 4446 return -EINVAL; 4447 return 0; 4448 case BPF_PROG_TYPE_SCHED_CLS: 4449 if (attach_type != BPF_TCX_INGRESS && 4450 attach_type != BPF_TCX_EGRESS && 4451 attach_type != BPF_NETKIT_PRIMARY && 4452 attach_type != BPF_NETKIT_PEER) 4453 return -EINVAL; 4454 return 0; 4455 default: 4456 ptype = attach_type_to_prog_type(attach_type); 4457 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4458 return -EINVAL; 4459 return 0; 4460 } 4461 } 4462 4463 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, 4464 bool check_atype) 4465 { 4466 switch (ptype) { 4467 case BPF_PROG_TYPE_CGROUP_DEVICE: 4468 case BPF_PROG_TYPE_CGROUP_SKB: 4469 case BPF_PROG_TYPE_CGROUP_SOCK: 4470 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4471 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4472 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4473 case BPF_PROG_TYPE_SOCK_OPS: 4474 return true; 4475 case BPF_PROG_TYPE_LSM: 4476 return check_atype ? atype == BPF_LSM_CGROUP : true; 4477 default: 4478 return false; 4479 } 4480 } 4481 4482 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4483 4484 #define BPF_F_ATTACH_MASK_BASE \ 4485 (BPF_F_ALLOW_OVERRIDE | \ 4486 BPF_F_ALLOW_MULTI | \ 4487 BPF_F_REPLACE | \ 4488 BPF_F_PREORDER) 4489 4490 #define BPF_F_ATTACH_MASK_MPROG \ 4491 (BPF_F_REPLACE | \ 4492 BPF_F_BEFORE | \ 4493 BPF_F_AFTER | \ 4494 BPF_F_ID | \ 4495 BPF_F_LINK) 4496 4497 static int bpf_prog_attach(const union bpf_attr *attr) 4498 { 4499 enum bpf_prog_type ptype; 4500 struct bpf_prog *prog; 4501 int ret; 4502 4503 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4504 return -EINVAL; 4505 4506 ptype = attach_type_to_prog_type(attr->attach_type); 4507 if (ptype == BPF_PROG_TYPE_UNSPEC) 4508 return -EINVAL; 4509 if (bpf_mprog_supported(ptype)) { 4510 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4511 return -EINVAL; 4512 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4513 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) 4514 return -EINVAL; 4515 } else { 4516 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4517 return -EINVAL; 4518 if (attr->relative_fd || 4519 attr->expected_revision) 4520 return -EINVAL; 4521 } 4522 4523 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4524 if (IS_ERR(prog)) 4525 return PTR_ERR(prog); 4526 4527 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4528 bpf_prog_put(prog); 4529 return -EINVAL; 4530 } 4531 4532 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { 4533 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4534 goto out; 4535 } 4536 4537 switch (ptype) { 4538 case BPF_PROG_TYPE_SK_SKB: 4539 case BPF_PROG_TYPE_SK_MSG: 4540 ret = sock_map_get_from_fd(attr, prog); 4541 break; 4542 case BPF_PROG_TYPE_LIRC_MODE2: 4543 ret = lirc_prog_attach(attr, prog); 4544 break; 4545 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4546 ret = netns_bpf_prog_attach(attr, prog); 4547 break; 4548 case BPF_PROG_TYPE_SCHED_CLS: 4549 if (attr->attach_type == BPF_TCX_INGRESS || 4550 attr->attach_type == BPF_TCX_EGRESS) 4551 ret = tcx_prog_attach(attr, prog); 4552 else 4553 ret = netkit_prog_attach(attr, prog); 4554 break; 4555 default: 4556 ret = -EINVAL; 4557 } 4558 out: 4559 if (ret) 4560 bpf_prog_put(prog); 4561 return ret; 4562 } 4563 4564 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4565 4566 static int bpf_prog_detach(const union bpf_attr *attr) 4567 { 4568 struct bpf_prog *prog = NULL; 4569 enum bpf_prog_type ptype; 4570 int ret; 4571 4572 if (CHECK_ATTR(BPF_PROG_DETACH)) 4573 return -EINVAL; 4574 4575 ptype = attach_type_to_prog_type(attr->attach_type); 4576 if (bpf_mprog_supported(ptype)) { 4577 if (ptype == BPF_PROG_TYPE_UNSPEC) 4578 return -EINVAL; 4579 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4580 return -EINVAL; 4581 if (attr->attach_bpf_fd) { 4582 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4583 if (IS_ERR(prog)) 4584 return PTR_ERR(prog); 4585 } else if (!bpf_mprog_detach_empty(ptype)) { 4586 return -EPERM; 4587 } 4588 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4589 if (attr->attach_flags || attr->relative_fd) 4590 return -EINVAL; 4591 } else if (attr->attach_flags || 4592 attr->relative_fd || 4593 attr->expected_revision) { 4594 return -EINVAL; 4595 } 4596 4597 switch (ptype) { 4598 case BPF_PROG_TYPE_SK_MSG: 4599 case BPF_PROG_TYPE_SK_SKB: 4600 ret = sock_map_prog_detach(attr, ptype); 4601 break; 4602 case BPF_PROG_TYPE_LIRC_MODE2: 4603 ret = lirc_prog_detach(attr); 4604 break; 4605 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4606 ret = netns_bpf_prog_detach(attr, ptype); 4607 break; 4608 case BPF_PROG_TYPE_CGROUP_DEVICE: 4609 case BPF_PROG_TYPE_CGROUP_SKB: 4610 case BPF_PROG_TYPE_CGROUP_SOCK: 4611 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4612 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4613 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4614 case BPF_PROG_TYPE_SOCK_OPS: 4615 case BPF_PROG_TYPE_LSM: 4616 ret = cgroup_bpf_prog_detach(attr, ptype); 4617 break; 4618 case BPF_PROG_TYPE_SCHED_CLS: 4619 if (attr->attach_type == BPF_TCX_INGRESS || 4620 attr->attach_type == BPF_TCX_EGRESS) 4621 ret = tcx_prog_detach(attr, prog); 4622 else 4623 ret = netkit_prog_detach(attr, prog); 4624 break; 4625 default: 4626 ret = -EINVAL; 4627 } 4628 4629 if (prog) 4630 bpf_prog_put(prog); 4631 return ret; 4632 } 4633 4634 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4635 4636 static int bpf_prog_query(const union bpf_attr *attr, 4637 union bpf_attr __user *uattr) 4638 { 4639 if (!bpf_net_capable()) 4640 return -EPERM; 4641 if (CHECK_ATTR(BPF_PROG_QUERY)) 4642 return -EINVAL; 4643 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4644 return -EINVAL; 4645 4646 switch (attr->query.attach_type) { 4647 case BPF_CGROUP_INET_INGRESS: 4648 case BPF_CGROUP_INET_EGRESS: 4649 case BPF_CGROUP_INET_SOCK_CREATE: 4650 case BPF_CGROUP_INET_SOCK_RELEASE: 4651 case BPF_CGROUP_INET4_BIND: 4652 case BPF_CGROUP_INET6_BIND: 4653 case BPF_CGROUP_INET4_POST_BIND: 4654 case BPF_CGROUP_INET6_POST_BIND: 4655 case BPF_CGROUP_INET4_CONNECT: 4656 case BPF_CGROUP_INET6_CONNECT: 4657 case BPF_CGROUP_UNIX_CONNECT: 4658 case BPF_CGROUP_INET4_GETPEERNAME: 4659 case BPF_CGROUP_INET6_GETPEERNAME: 4660 case BPF_CGROUP_UNIX_GETPEERNAME: 4661 case BPF_CGROUP_INET4_GETSOCKNAME: 4662 case BPF_CGROUP_INET6_GETSOCKNAME: 4663 case BPF_CGROUP_UNIX_GETSOCKNAME: 4664 case BPF_CGROUP_UDP4_SENDMSG: 4665 case BPF_CGROUP_UDP6_SENDMSG: 4666 case BPF_CGROUP_UNIX_SENDMSG: 4667 case BPF_CGROUP_UDP4_RECVMSG: 4668 case BPF_CGROUP_UDP6_RECVMSG: 4669 case BPF_CGROUP_UNIX_RECVMSG: 4670 case BPF_CGROUP_SOCK_OPS: 4671 case BPF_CGROUP_DEVICE: 4672 case BPF_CGROUP_SYSCTL: 4673 case BPF_CGROUP_GETSOCKOPT: 4674 case BPF_CGROUP_SETSOCKOPT: 4675 case BPF_LSM_CGROUP: 4676 return cgroup_bpf_prog_query(attr, uattr); 4677 case BPF_LIRC_MODE2: 4678 return lirc_prog_query(attr, uattr); 4679 case BPF_FLOW_DISSECTOR: 4680 case BPF_SK_LOOKUP: 4681 return netns_bpf_prog_query(attr, uattr); 4682 case BPF_SK_SKB_STREAM_PARSER: 4683 case BPF_SK_SKB_STREAM_VERDICT: 4684 case BPF_SK_MSG_VERDICT: 4685 case BPF_SK_SKB_VERDICT: 4686 return sock_map_bpf_prog_query(attr, uattr); 4687 case BPF_TCX_INGRESS: 4688 case BPF_TCX_EGRESS: 4689 return tcx_prog_query(attr, uattr); 4690 case BPF_NETKIT_PRIMARY: 4691 case BPF_NETKIT_PEER: 4692 return netkit_prog_query(attr, uattr); 4693 default: 4694 return -EINVAL; 4695 } 4696 } 4697 4698 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4699 4700 static int bpf_prog_test_run(const union bpf_attr *attr, 4701 union bpf_attr __user *uattr) 4702 { 4703 struct bpf_prog *prog; 4704 int ret = -ENOTSUPP; 4705 4706 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4707 return -EINVAL; 4708 4709 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4710 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4711 return -EINVAL; 4712 4713 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4714 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4715 return -EINVAL; 4716 4717 prog = bpf_prog_get(attr->test.prog_fd); 4718 if (IS_ERR(prog)) 4719 return PTR_ERR(prog); 4720 4721 if (prog->aux->ops->test_run) 4722 ret = prog->aux->ops->test_run(prog, attr, uattr); 4723 4724 bpf_prog_put(prog); 4725 return ret; 4726 } 4727 4728 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4729 4730 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4731 union bpf_attr __user *uattr, 4732 struct idr *idr, 4733 spinlock_t *lock) 4734 { 4735 u32 next_id = attr->start_id; 4736 int err = 0; 4737 4738 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4739 return -EINVAL; 4740 4741 if (!capable(CAP_SYS_ADMIN)) 4742 return -EPERM; 4743 4744 next_id++; 4745 spin_lock_bh(lock); 4746 if (!idr_get_next(idr, &next_id)) 4747 err = -ENOENT; 4748 spin_unlock_bh(lock); 4749 4750 if (!err) 4751 err = put_user(next_id, &uattr->next_id); 4752 4753 return err; 4754 } 4755 4756 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4757 { 4758 struct bpf_map *map; 4759 4760 spin_lock_bh(&map_idr_lock); 4761 again: 4762 map = idr_get_next(&map_idr, id); 4763 if (map) { 4764 map = __bpf_map_inc_not_zero(map, false); 4765 if (IS_ERR(map)) { 4766 (*id)++; 4767 goto again; 4768 } 4769 } 4770 spin_unlock_bh(&map_idr_lock); 4771 4772 return map; 4773 } 4774 4775 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4776 { 4777 struct bpf_prog *prog; 4778 4779 spin_lock_bh(&prog_idr_lock); 4780 again: 4781 prog = idr_get_next(&prog_idr, id); 4782 if (prog) { 4783 prog = bpf_prog_inc_not_zero(prog); 4784 if (IS_ERR(prog)) { 4785 (*id)++; 4786 goto again; 4787 } 4788 } 4789 spin_unlock_bh(&prog_idr_lock); 4790 4791 return prog; 4792 } 4793 4794 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4795 4796 struct bpf_prog *bpf_prog_by_id(u32 id) 4797 { 4798 struct bpf_prog *prog; 4799 4800 if (!id) 4801 return ERR_PTR(-ENOENT); 4802 4803 spin_lock_bh(&prog_idr_lock); 4804 prog = idr_find(&prog_idr, id); 4805 if (prog) 4806 prog = bpf_prog_inc_not_zero(prog); 4807 else 4808 prog = ERR_PTR(-ENOENT); 4809 spin_unlock_bh(&prog_idr_lock); 4810 return prog; 4811 } 4812 4813 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4814 { 4815 struct bpf_prog *prog; 4816 u32 id = attr->prog_id; 4817 int fd; 4818 4819 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4820 return -EINVAL; 4821 4822 if (!capable(CAP_SYS_ADMIN)) 4823 return -EPERM; 4824 4825 prog = bpf_prog_by_id(id); 4826 if (IS_ERR(prog)) 4827 return PTR_ERR(prog); 4828 4829 fd = bpf_prog_new_fd(prog); 4830 if (fd < 0) 4831 bpf_prog_put(prog); 4832 4833 return fd; 4834 } 4835 4836 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4837 4838 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4839 { 4840 struct bpf_map *map; 4841 u32 id = attr->map_id; 4842 int f_flags; 4843 int fd; 4844 4845 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4846 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4847 return -EINVAL; 4848 4849 if (!capable(CAP_SYS_ADMIN)) 4850 return -EPERM; 4851 4852 f_flags = bpf_get_file_flag(attr->open_flags); 4853 if (f_flags < 0) 4854 return f_flags; 4855 4856 spin_lock_bh(&map_idr_lock); 4857 map = idr_find(&map_idr, id); 4858 if (map) 4859 map = __bpf_map_inc_not_zero(map, true); 4860 else 4861 map = ERR_PTR(-ENOENT); 4862 spin_unlock_bh(&map_idr_lock); 4863 4864 if (IS_ERR(map)) 4865 return PTR_ERR(map); 4866 4867 fd = bpf_map_new_fd(map, f_flags); 4868 if (fd < 0) 4869 bpf_map_put_with_uref(map); 4870 4871 return fd; 4872 } 4873 4874 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4875 unsigned long addr, u32 *off, 4876 u32 *type) 4877 { 4878 const struct bpf_map *map; 4879 int i; 4880 4881 mutex_lock(&prog->aux->used_maps_mutex); 4882 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4883 map = prog->aux->used_maps[i]; 4884 if (map == (void *)addr) { 4885 *type = BPF_PSEUDO_MAP_FD; 4886 goto out; 4887 } 4888 if (!map->ops->map_direct_value_meta) 4889 continue; 4890 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4891 *type = BPF_PSEUDO_MAP_VALUE; 4892 goto out; 4893 } 4894 } 4895 map = NULL; 4896 4897 out: 4898 mutex_unlock(&prog->aux->used_maps_mutex); 4899 return map; 4900 } 4901 4902 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 4903 const struct cred *f_cred) 4904 { 4905 const struct bpf_map *map; 4906 struct bpf_insn *insns; 4907 u32 off, type; 4908 u64 imm; 4909 u8 code; 4910 int i; 4911 4912 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 4913 GFP_USER); 4914 if (!insns) 4915 return insns; 4916 4917 for (i = 0; i < prog->len; i++) { 4918 code = insns[i].code; 4919 4920 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 4921 insns[i].code = BPF_JMP | BPF_CALL; 4922 insns[i].imm = BPF_FUNC_tail_call; 4923 /* fall-through */ 4924 } 4925 if (code == (BPF_JMP | BPF_CALL) || 4926 code == (BPF_JMP | BPF_CALL_ARGS)) { 4927 if (code == (BPF_JMP | BPF_CALL_ARGS)) 4928 insns[i].code = BPF_JMP | BPF_CALL; 4929 if (!bpf_dump_raw_ok(f_cred)) 4930 insns[i].imm = 0; 4931 continue; 4932 } 4933 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 4934 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 4935 continue; 4936 } 4937 4938 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 4939 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 4940 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 4941 continue; 4942 } 4943 4944 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 4945 continue; 4946 4947 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 4948 map = bpf_map_from_imm(prog, imm, &off, &type); 4949 if (map) { 4950 insns[i].src_reg = type; 4951 insns[i].imm = map->id; 4952 insns[i + 1].imm = off; 4953 continue; 4954 } 4955 } 4956 4957 return insns; 4958 } 4959 4960 static int set_info_rec_size(struct bpf_prog_info *info) 4961 { 4962 /* 4963 * Ensure info.*_rec_size is the same as kernel expected size 4964 * 4965 * or 4966 * 4967 * Only allow zero *_rec_size if both _rec_size and _cnt are 4968 * zero. In this case, the kernel will set the expected 4969 * _rec_size back to the info. 4970 */ 4971 4972 if ((info->nr_func_info || info->func_info_rec_size) && 4973 info->func_info_rec_size != sizeof(struct bpf_func_info)) 4974 return -EINVAL; 4975 4976 if ((info->nr_line_info || info->line_info_rec_size) && 4977 info->line_info_rec_size != sizeof(struct bpf_line_info)) 4978 return -EINVAL; 4979 4980 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 4981 info->jited_line_info_rec_size != sizeof(__u64)) 4982 return -EINVAL; 4983 4984 info->func_info_rec_size = sizeof(struct bpf_func_info); 4985 info->line_info_rec_size = sizeof(struct bpf_line_info); 4986 info->jited_line_info_rec_size = sizeof(__u64); 4987 4988 return 0; 4989 } 4990 4991 static int bpf_prog_get_info_by_fd(struct file *file, 4992 struct bpf_prog *prog, 4993 const union bpf_attr *attr, 4994 union bpf_attr __user *uattr) 4995 { 4996 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4997 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 4998 struct bpf_prog_info info; 4999 u32 info_len = attr->info.info_len; 5000 struct bpf_prog_kstats stats; 5001 char __user *uinsns; 5002 u32 ulen; 5003 int err; 5004 5005 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5006 if (err) 5007 return err; 5008 info_len = min_t(u32, sizeof(info), info_len); 5009 5010 memset(&info, 0, sizeof(info)); 5011 if (copy_from_user(&info, uinfo, info_len)) 5012 return -EFAULT; 5013 5014 info.type = prog->type; 5015 info.id = prog->aux->id; 5016 info.load_time = prog->aux->load_time; 5017 info.created_by_uid = from_kuid_munged(current_user_ns(), 5018 prog->aux->user->uid); 5019 info.gpl_compatible = prog->gpl_compatible; 5020 5021 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 5022 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 5023 5024 mutex_lock(&prog->aux->used_maps_mutex); 5025 ulen = info.nr_map_ids; 5026 info.nr_map_ids = prog->aux->used_map_cnt; 5027 ulen = min_t(u32, info.nr_map_ids, ulen); 5028 if (ulen) { 5029 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 5030 u32 i; 5031 5032 for (i = 0; i < ulen; i++) 5033 if (put_user(prog->aux->used_maps[i]->id, 5034 &user_map_ids[i])) { 5035 mutex_unlock(&prog->aux->used_maps_mutex); 5036 return -EFAULT; 5037 } 5038 } 5039 mutex_unlock(&prog->aux->used_maps_mutex); 5040 5041 err = set_info_rec_size(&info); 5042 if (err) 5043 return err; 5044 5045 bpf_prog_get_stats(prog, &stats); 5046 info.run_time_ns = stats.nsecs; 5047 info.run_cnt = stats.cnt; 5048 info.recursion_misses = stats.misses; 5049 5050 info.verified_insns = prog->aux->verified_insns; 5051 if (prog->aux->btf) 5052 info.btf_id = btf_obj_id(prog->aux->btf); 5053 5054 if (!bpf_capable()) { 5055 info.jited_prog_len = 0; 5056 info.xlated_prog_len = 0; 5057 info.nr_jited_ksyms = 0; 5058 info.nr_jited_func_lens = 0; 5059 info.nr_func_info = 0; 5060 info.nr_line_info = 0; 5061 info.nr_jited_line_info = 0; 5062 goto done; 5063 } 5064 5065 ulen = info.xlated_prog_len; 5066 info.xlated_prog_len = bpf_prog_insn_size(prog); 5067 if (info.xlated_prog_len && ulen) { 5068 struct bpf_insn *insns_sanitized; 5069 bool fault; 5070 5071 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) { 5072 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 5073 if (!insns_sanitized) 5074 return -ENOMEM; 5075 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 5076 ulen = min_t(u32, info.xlated_prog_len, ulen); 5077 fault = copy_to_user(uinsns, insns_sanitized, ulen); 5078 kfree(insns_sanitized); 5079 if (fault) 5080 return -EFAULT; 5081 } else { 5082 info.xlated_prog_insns = 0; 5083 } 5084 } 5085 5086 if (bpf_prog_is_offloaded(prog->aux)) { 5087 err = bpf_prog_offload_info_fill(&info, prog); 5088 if (err) 5089 return err; 5090 goto done; 5091 } 5092 5093 /* NOTE: the following code is supposed to be skipped for offload. 5094 * bpf_prog_offload_info_fill() is the place to fill similar fields 5095 * for offload. 5096 */ 5097 ulen = info.jited_prog_len; 5098 if (prog->aux->func_cnt) { 5099 u32 i; 5100 5101 info.jited_prog_len = 0; 5102 for (i = 0; i < prog->aux->func_cnt; i++) 5103 info.jited_prog_len += prog->aux->func[i]->jited_len; 5104 } else { 5105 info.jited_prog_len = prog->jited_len; 5106 } 5107 5108 if (info.jited_prog_len && ulen) { 5109 if (bpf_dump_raw_ok(file->f_cred)) { 5110 uinsns = u64_to_user_ptr(info.jited_prog_insns); 5111 ulen = min_t(u32, info.jited_prog_len, ulen); 5112 5113 /* for multi-function programs, copy the JITed 5114 * instructions for all the functions 5115 */ 5116 if (prog->aux->func_cnt) { 5117 u32 len, free, i; 5118 u8 *img; 5119 5120 free = ulen; 5121 for (i = 0; i < prog->aux->func_cnt; i++) { 5122 len = prog->aux->func[i]->jited_len; 5123 len = min_t(u32, len, free); 5124 img = (u8 *) prog->aux->func[i]->bpf_func; 5125 if (copy_to_user(uinsns, img, len)) 5126 return -EFAULT; 5127 uinsns += len; 5128 free -= len; 5129 if (!free) 5130 break; 5131 } 5132 } else { 5133 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 5134 return -EFAULT; 5135 } 5136 } else { 5137 info.jited_prog_insns = 0; 5138 } 5139 } 5140 5141 ulen = info.nr_jited_ksyms; 5142 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 5143 if (ulen) { 5144 if (bpf_dump_raw_ok(file->f_cred)) { 5145 unsigned long ksym_addr; 5146 u64 __user *user_ksyms; 5147 u32 i; 5148 5149 /* copy the address of the kernel symbol 5150 * corresponding to each function 5151 */ 5152 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 5153 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 5154 if (prog->aux->func_cnt) { 5155 for (i = 0; i < ulen; i++) { 5156 ksym_addr = (unsigned long) 5157 prog->aux->func[i]->bpf_func; 5158 if (put_user((u64) ksym_addr, 5159 &user_ksyms[i])) 5160 return -EFAULT; 5161 } 5162 } else { 5163 ksym_addr = (unsigned long) prog->bpf_func; 5164 if (put_user((u64) ksym_addr, &user_ksyms[0])) 5165 return -EFAULT; 5166 } 5167 } else { 5168 info.jited_ksyms = 0; 5169 } 5170 } 5171 5172 ulen = info.nr_jited_func_lens; 5173 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 5174 if (ulen) { 5175 if (bpf_dump_raw_ok(file->f_cred)) { 5176 u32 __user *user_lens; 5177 u32 func_len, i; 5178 5179 /* copy the JITed image lengths for each function */ 5180 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 5181 user_lens = u64_to_user_ptr(info.jited_func_lens); 5182 if (prog->aux->func_cnt) { 5183 for (i = 0; i < ulen; i++) { 5184 func_len = 5185 prog->aux->func[i]->jited_len; 5186 if (put_user(func_len, &user_lens[i])) 5187 return -EFAULT; 5188 } 5189 } else { 5190 func_len = prog->jited_len; 5191 if (put_user(func_len, &user_lens[0])) 5192 return -EFAULT; 5193 } 5194 } else { 5195 info.jited_func_lens = 0; 5196 } 5197 } 5198 5199 info.attach_btf_id = prog->aux->attach_btf_id; 5200 if (attach_btf) 5201 info.attach_btf_obj_id = btf_obj_id(attach_btf); 5202 5203 ulen = info.nr_func_info; 5204 info.nr_func_info = prog->aux->func_info_cnt; 5205 if (info.nr_func_info && ulen) { 5206 char __user *user_finfo; 5207 5208 user_finfo = u64_to_user_ptr(info.func_info); 5209 ulen = min_t(u32, info.nr_func_info, ulen); 5210 if (copy_to_user(user_finfo, prog->aux->func_info, 5211 info.func_info_rec_size * ulen)) 5212 return -EFAULT; 5213 } 5214 5215 ulen = info.nr_line_info; 5216 info.nr_line_info = prog->aux->nr_linfo; 5217 if (info.nr_line_info && ulen) { 5218 __u8 __user *user_linfo; 5219 5220 user_linfo = u64_to_user_ptr(info.line_info); 5221 ulen = min_t(u32, info.nr_line_info, ulen); 5222 if (copy_to_user(user_linfo, prog->aux->linfo, 5223 info.line_info_rec_size * ulen)) 5224 return -EFAULT; 5225 } 5226 5227 ulen = info.nr_jited_line_info; 5228 if (prog->aux->jited_linfo) 5229 info.nr_jited_line_info = prog->aux->nr_linfo; 5230 else 5231 info.nr_jited_line_info = 0; 5232 if (info.nr_jited_line_info && ulen) { 5233 if (bpf_dump_raw_ok(file->f_cred)) { 5234 unsigned long line_addr; 5235 __u64 __user *user_linfo; 5236 u32 i; 5237 5238 user_linfo = u64_to_user_ptr(info.jited_line_info); 5239 ulen = min_t(u32, info.nr_jited_line_info, ulen); 5240 for (i = 0; i < ulen; i++) { 5241 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 5242 if (put_user((__u64)line_addr, &user_linfo[i])) 5243 return -EFAULT; 5244 } 5245 } else { 5246 info.jited_line_info = 0; 5247 } 5248 } 5249 5250 ulen = info.nr_prog_tags; 5251 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 5252 if (ulen) { 5253 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 5254 u32 i; 5255 5256 user_prog_tags = u64_to_user_ptr(info.prog_tags); 5257 ulen = min_t(u32, info.nr_prog_tags, ulen); 5258 if (prog->aux->func_cnt) { 5259 for (i = 0; i < ulen; i++) { 5260 if (copy_to_user(user_prog_tags[i], 5261 prog->aux->func[i]->tag, 5262 BPF_TAG_SIZE)) 5263 return -EFAULT; 5264 } 5265 } else { 5266 if (copy_to_user(user_prog_tags[0], 5267 prog->tag, BPF_TAG_SIZE)) 5268 return -EFAULT; 5269 } 5270 } 5271 5272 done: 5273 if (copy_to_user(uinfo, &info, info_len) || 5274 put_user(info_len, &uattr->info.info_len)) 5275 return -EFAULT; 5276 5277 return 0; 5278 } 5279 5280 static int bpf_map_get_info_by_fd(struct file *file, 5281 struct bpf_map *map, 5282 const union bpf_attr *attr, 5283 union bpf_attr __user *uattr) 5284 { 5285 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5286 struct bpf_map_info info; 5287 u32 info_len = attr->info.info_len; 5288 int err; 5289 5290 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5291 if (err) 5292 return err; 5293 info_len = min_t(u32, sizeof(info), info_len); 5294 5295 memset(&info, 0, sizeof(info)); 5296 if (copy_from_user(&info, uinfo, info_len)) 5297 return -EFAULT; 5298 5299 info.type = map->map_type; 5300 info.id = map->id; 5301 info.key_size = map->key_size; 5302 info.value_size = map->value_size; 5303 info.max_entries = map->max_entries; 5304 info.map_flags = map->map_flags; 5305 info.map_extra = map->map_extra; 5306 memcpy(info.name, map->name, sizeof(map->name)); 5307 5308 if (map->btf) { 5309 info.btf_id = btf_obj_id(map->btf); 5310 info.btf_key_type_id = map->btf_key_type_id; 5311 info.btf_value_type_id = map->btf_value_type_id; 5312 } 5313 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 5314 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 5315 bpf_map_struct_ops_info_fill(&info, map); 5316 5317 if (bpf_map_is_offloaded(map)) { 5318 err = bpf_map_offload_info_fill(&info, map); 5319 if (err) 5320 return err; 5321 } 5322 5323 if (info.hash) { 5324 char __user *uhash = u64_to_user_ptr(info.hash); 5325 5326 if (!map->ops->map_get_hash) 5327 return -EINVAL; 5328 5329 if (info.hash_size != SHA256_DIGEST_SIZE) 5330 return -EINVAL; 5331 5332 if (!READ_ONCE(map->frozen)) 5333 return -EPERM; 5334 5335 err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha); 5336 if (err != 0) 5337 return err; 5338 5339 if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0) 5340 return -EFAULT; 5341 } else if (info.hash_size) { 5342 return -EINVAL; 5343 } 5344 5345 if (copy_to_user(uinfo, &info, info_len) || 5346 put_user(info_len, &uattr->info.info_len)) 5347 return -EFAULT; 5348 5349 return 0; 5350 } 5351 5352 static int bpf_btf_get_info_by_fd(struct file *file, 5353 struct btf *btf, 5354 const union bpf_attr *attr, 5355 union bpf_attr __user *uattr) 5356 { 5357 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5358 u32 info_len = attr->info.info_len; 5359 int err; 5360 5361 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5362 if (err) 5363 return err; 5364 5365 return btf_get_info_by_fd(btf, attr, uattr); 5366 } 5367 5368 static int bpf_link_get_info_by_fd(struct file *file, 5369 struct bpf_link *link, 5370 const union bpf_attr *attr, 5371 union bpf_attr __user *uattr) 5372 { 5373 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5374 struct bpf_link_info info; 5375 u32 info_len = attr->info.info_len; 5376 int err; 5377 5378 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5379 if (err) 5380 return err; 5381 info_len = min_t(u32, sizeof(info), info_len); 5382 5383 memset(&info, 0, sizeof(info)); 5384 if (copy_from_user(&info, uinfo, info_len)) 5385 return -EFAULT; 5386 5387 info.type = link->type; 5388 info.id = link->id; 5389 if (link->prog) 5390 info.prog_id = link->prog->aux->id; 5391 5392 if (link->ops->fill_link_info) { 5393 err = link->ops->fill_link_info(link, &info); 5394 if (err) 5395 return err; 5396 } 5397 5398 if (copy_to_user(uinfo, &info, info_len) || 5399 put_user(info_len, &uattr->info.info_len)) 5400 return -EFAULT; 5401 5402 return 0; 5403 } 5404 5405 5406 static int token_get_info_by_fd(struct file *file, 5407 struct bpf_token *token, 5408 const union bpf_attr *attr, 5409 union bpf_attr __user *uattr) 5410 { 5411 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5412 u32 info_len = attr->info.info_len; 5413 int err; 5414 5415 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5416 if (err) 5417 return err; 5418 return bpf_token_get_info_by_fd(token, attr, uattr); 5419 } 5420 5421 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5422 5423 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5424 union bpf_attr __user *uattr) 5425 { 5426 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5427 return -EINVAL; 5428 5429 CLASS(fd, f)(attr->info.bpf_fd); 5430 if (fd_empty(f)) 5431 return -EBADFD; 5432 5433 if (fd_file(f)->f_op == &bpf_prog_fops) 5434 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5435 uattr); 5436 else if (fd_file(f)->f_op == &bpf_map_fops) 5437 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5438 uattr); 5439 else if (fd_file(f)->f_op == &btf_fops) 5440 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5441 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5442 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5443 attr, uattr); 5444 else if (fd_file(f)->f_op == &bpf_token_fops) 5445 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5446 attr, uattr); 5447 return -EINVAL; 5448 } 5449 5450 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5451 5452 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) 5453 { 5454 struct bpf_token *token = NULL; 5455 5456 if (CHECK_ATTR(BPF_BTF_LOAD)) 5457 return -EINVAL; 5458 5459 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5460 return -EINVAL; 5461 5462 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5463 token = bpf_token_get_from_fd(attr->btf_token_fd); 5464 if (IS_ERR(token)) 5465 return PTR_ERR(token); 5466 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5467 bpf_token_put(token); 5468 token = NULL; 5469 } 5470 } 5471 5472 if (!bpf_token_capable(token, CAP_BPF)) { 5473 bpf_token_put(token); 5474 return -EPERM; 5475 } 5476 5477 bpf_token_put(token); 5478 5479 return btf_new_fd(attr, uattr, uattr_size); 5480 } 5481 5482 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd 5483 5484 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5485 { 5486 struct bpf_token *token = NULL; 5487 5488 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5489 return -EINVAL; 5490 5491 if (attr->open_flags & ~BPF_F_TOKEN_FD) 5492 return -EINVAL; 5493 5494 if (attr->open_flags & BPF_F_TOKEN_FD) { 5495 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); 5496 if (IS_ERR(token)) 5497 return PTR_ERR(token); 5498 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { 5499 bpf_token_put(token); 5500 token = NULL; 5501 } 5502 } 5503 5504 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { 5505 bpf_token_put(token); 5506 return -EPERM; 5507 } 5508 5509 bpf_token_put(token); 5510 5511 return btf_get_fd_by_id(attr->btf_id); 5512 } 5513 5514 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5515 union bpf_attr __user *uattr, 5516 u32 prog_id, u32 fd_type, 5517 const char *buf, u64 probe_offset, 5518 u64 probe_addr) 5519 { 5520 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5521 u32 len = buf ? strlen(buf) : 0, input_len; 5522 int err = 0; 5523 5524 if (put_user(len, &uattr->task_fd_query.buf_len)) 5525 return -EFAULT; 5526 input_len = attr->task_fd_query.buf_len; 5527 if (input_len && ubuf) { 5528 if (!len) { 5529 /* nothing to copy, just make ubuf NULL terminated */ 5530 char zero = '\0'; 5531 5532 if (put_user(zero, ubuf)) 5533 return -EFAULT; 5534 } else { 5535 err = bpf_copy_to_user(ubuf, buf, input_len, len); 5536 if (err == -EFAULT) 5537 return err; 5538 } 5539 } 5540 5541 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5542 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5543 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5544 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5545 return -EFAULT; 5546 5547 return err; 5548 } 5549 5550 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5551 5552 static int bpf_task_fd_query(const union bpf_attr *attr, 5553 union bpf_attr __user *uattr) 5554 { 5555 pid_t pid = attr->task_fd_query.pid; 5556 u32 fd = attr->task_fd_query.fd; 5557 const struct perf_event *event; 5558 struct task_struct *task; 5559 struct file *file; 5560 int err; 5561 5562 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5563 return -EINVAL; 5564 5565 if (!capable(CAP_SYS_ADMIN)) 5566 return -EPERM; 5567 5568 if (attr->task_fd_query.flags != 0) 5569 return -EINVAL; 5570 5571 rcu_read_lock(); 5572 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5573 rcu_read_unlock(); 5574 if (!task) 5575 return -ENOENT; 5576 5577 err = 0; 5578 file = fget_task(task, fd); 5579 put_task_struct(task); 5580 if (!file) 5581 return -EBADF; 5582 5583 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5584 struct bpf_link *link = file->private_data; 5585 5586 if (link->ops == &bpf_raw_tp_link_lops) { 5587 struct bpf_raw_tp_link *raw_tp = 5588 container_of(link, struct bpf_raw_tp_link, link); 5589 struct bpf_raw_event_map *btp = raw_tp->btp; 5590 5591 err = bpf_task_fd_query_copy(attr, uattr, 5592 raw_tp->link.prog->aux->id, 5593 BPF_FD_TYPE_RAW_TRACEPOINT, 5594 btp->tp->name, 0, 0); 5595 goto put_file; 5596 } 5597 goto out_not_supp; 5598 } 5599 5600 event = perf_get_event(file); 5601 if (!IS_ERR(event)) { 5602 u64 probe_offset, probe_addr; 5603 u32 prog_id, fd_type; 5604 const char *buf; 5605 5606 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5607 &buf, &probe_offset, 5608 &probe_addr, NULL); 5609 if (!err) 5610 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5611 fd_type, buf, 5612 probe_offset, 5613 probe_addr); 5614 goto put_file; 5615 } 5616 5617 out_not_supp: 5618 err = -ENOTSUPP; 5619 put_file: 5620 fput(file); 5621 return err; 5622 } 5623 5624 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5625 5626 #define BPF_DO_BATCH(fn, ...) \ 5627 do { \ 5628 if (!fn) { \ 5629 err = -ENOTSUPP; \ 5630 goto err_put; \ 5631 } \ 5632 err = fn(__VA_ARGS__); \ 5633 } while (0) 5634 5635 static int bpf_map_do_batch(const union bpf_attr *attr, 5636 union bpf_attr __user *uattr, 5637 int cmd) 5638 { 5639 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5640 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5641 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5642 struct bpf_map *map; 5643 int err; 5644 5645 if (CHECK_ATTR(BPF_MAP_BATCH)) 5646 return -EINVAL; 5647 5648 CLASS(fd, f)(attr->batch.map_fd); 5649 5650 map = __bpf_map_get(f); 5651 if (IS_ERR(map)) 5652 return PTR_ERR(map); 5653 if (has_write) 5654 bpf_map_write_active_inc(map); 5655 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5656 err = -EPERM; 5657 goto err_put; 5658 } 5659 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5660 err = -EPERM; 5661 goto err_put; 5662 } 5663 5664 if (cmd == BPF_MAP_LOOKUP_BATCH) 5665 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5666 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5667 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5668 else if (cmd == BPF_MAP_UPDATE_BATCH) 5669 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5670 else 5671 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5672 err_put: 5673 if (has_write) { 5674 maybe_wait_bpf_programs(map); 5675 bpf_map_write_active_dec(map); 5676 } 5677 return err; 5678 } 5679 5680 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 5681 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5682 { 5683 struct bpf_prog *prog; 5684 int ret; 5685 5686 if (CHECK_ATTR(BPF_LINK_CREATE)) 5687 return -EINVAL; 5688 5689 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5690 return bpf_struct_ops_link_create(attr); 5691 5692 prog = bpf_prog_get(attr->link_create.prog_fd); 5693 if (IS_ERR(prog)) 5694 return PTR_ERR(prog); 5695 5696 ret = bpf_prog_attach_check_attach_type(prog, 5697 attr->link_create.attach_type); 5698 if (ret) 5699 goto out; 5700 5701 switch (prog->type) { 5702 case BPF_PROG_TYPE_CGROUP_SKB: 5703 case BPF_PROG_TYPE_CGROUP_SOCK: 5704 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5705 case BPF_PROG_TYPE_SOCK_OPS: 5706 case BPF_PROG_TYPE_CGROUP_DEVICE: 5707 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5708 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5709 ret = cgroup_bpf_link_attach(attr, prog); 5710 break; 5711 case BPF_PROG_TYPE_EXT: 5712 ret = bpf_tracing_prog_attach(prog, 5713 attr->link_create.target_fd, 5714 attr->link_create.target_btf_id, 5715 attr->link_create.tracing.cookie, 5716 attr->link_create.attach_type); 5717 break; 5718 case BPF_PROG_TYPE_LSM: 5719 case BPF_PROG_TYPE_TRACING: 5720 if (attr->link_create.attach_type != prog->expected_attach_type) { 5721 ret = -EINVAL; 5722 goto out; 5723 } 5724 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5725 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, 5726 attr->link_create.attach_type); 5727 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5728 ret = bpf_iter_link_attach(attr, uattr, prog); 5729 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5730 ret = cgroup_bpf_link_attach(attr, prog); 5731 else 5732 ret = bpf_tracing_prog_attach(prog, 5733 attr->link_create.target_fd, 5734 attr->link_create.target_btf_id, 5735 attr->link_create.tracing.cookie, 5736 attr->link_create.attach_type); 5737 break; 5738 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5739 case BPF_PROG_TYPE_SK_LOOKUP: 5740 ret = netns_bpf_link_create(attr, prog); 5741 break; 5742 case BPF_PROG_TYPE_SK_MSG: 5743 case BPF_PROG_TYPE_SK_SKB: 5744 ret = sock_map_link_create(attr, prog); 5745 break; 5746 #ifdef CONFIG_NET 5747 case BPF_PROG_TYPE_XDP: 5748 ret = bpf_xdp_link_attach(attr, prog); 5749 break; 5750 case BPF_PROG_TYPE_SCHED_CLS: 5751 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5752 attr->link_create.attach_type == BPF_TCX_EGRESS) 5753 ret = tcx_link_attach(attr, prog); 5754 else 5755 ret = netkit_link_attach(attr, prog); 5756 break; 5757 case BPF_PROG_TYPE_NETFILTER: 5758 ret = bpf_nf_link_attach(attr, prog); 5759 break; 5760 #endif 5761 case BPF_PROG_TYPE_PERF_EVENT: 5762 case BPF_PROG_TYPE_TRACEPOINT: 5763 ret = bpf_perf_link_attach(attr, prog); 5764 break; 5765 case BPF_PROG_TYPE_KPROBE: 5766 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5767 ret = bpf_perf_link_attach(attr, prog); 5768 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5769 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5770 ret = bpf_kprobe_multi_link_attach(attr, prog); 5771 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5772 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5773 ret = bpf_uprobe_multi_link_attach(attr, prog); 5774 break; 5775 default: 5776 ret = -EINVAL; 5777 } 5778 5779 out: 5780 if (ret < 0) 5781 bpf_prog_put(prog); 5782 return ret; 5783 } 5784 5785 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5786 { 5787 struct bpf_map *new_map, *old_map = NULL; 5788 int ret; 5789 5790 new_map = bpf_map_get(attr->link_update.new_map_fd); 5791 if (IS_ERR(new_map)) 5792 return PTR_ERR(new_map); 5793 5794 if (attr->link_update.flags & BPF_F_REPLACE) { 5795 old_map = bpf_map_get(attr->link_update.old_map_fd); 5796 if (IS_ERR(old_map)) { 5797 ret = PTR_ERR(old_map); 5798 goto out_put; 5799 } 5800 } else if (attr->link_update.old_map_fd) { 5801 ret = -EINVAL; 5802 goto out_put; 5803 } 5804 5805 ret = link->ops->update_map(link, new_map, old_map); 5806 5807 if (old_map) 5808 bpf_map_put(old_map); 5809 out_put: 5810 bpf_map_put(new_map); 5811 return ret; 5812 } 5813 5814 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5815 5816 static int link_update(union bpf_attr *attr) 5817 { 5818 struct bpf_prog *old_prog = NULL, *new_prog; 5819 struct bpf_link *link; 5820 u32 flags; 5821 int ret; 5822 5823 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5824 return -EINVAL; 5825 5826 flags = attr->link_update.flags; 5827 if (flags & ~BPF_F_REPLACE) 5828 return -EINVAL; 5829 5830 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5831 if (IS_ERR(link)) 5832 return PTR_ERR(link); 5833 5834 if (link->ops->update_map) { 5835 ret = link_update_map(link, attr); 5836 goto out_put_link; 5837 } 5838 5839 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5840 if (IS_ERR(new_prog)) { 5841 ret = PTR_ERR(new_prog); 5842 goto out_put_link; 5843 } 5844 5845 if (flags & BPF_F_REPLACE) { 5846 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5847 if (IS_ERR(old_prog)) { 5848 ret = PTR_ERR(old_prog); 5849 old_prog = NULL; 5850 goto out_put_progs; 5851 } 5852 } else if (attr->link_update.old_prog_fd) { 5853 ret = -EINVAL; 5854 goto out_put_progs; 5855 } 5856 5857 if (link->ops->update_prog) 5858 ret = link->ops->update_prog(link, new_prog, old_prog); 5859 else 5860 ret = -EINVAL; 5861 5862 out_put_progs: 5863 if (old_prog) 5864 bpf_prog_put(old_prog); 5865 if (ret) 5866 bpf_prog_put(new_prog); 5867 out_put_link: 5868 bpf_link_put_direct(link); 5869 return ret; 5870 } 5871 5872 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5873 5874 static int link_detach(union bpf_attr *attr) 5875 { 5876 struct bpf_link *link; 5877 int ret; 5878 5879 if (CHECK_ATTR(BPF_LINK_DETACH)) 5880 return -EINVAL; 5881 5882 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 5883 if (IS_ERR(link)) 5884 return PTR_ERR(link); 5885 5886 if (link->ops->detach) 5887 ret = link->ops->detach(link); 5888 else 5889 ret = -EOPNOTSUPP; 5890 5891 bpf_link_put_direct(link); 5892 return ret; 5893 } 5894 5895 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 5896 { 5897 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 5898 } 5899 EXPORT_SYMBOL(bpf_link_inc_not_zero); 5900 5901 struct bpf_link *bpf_link_by_id(u32 id) 5902 { 5903 struct bpf_link *link; 5904 5905 if (!id) 5906 return ERR_PTR(-ENOENT); 5907 5908 spin_lock_bh(&link_idr_lock); 5909 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 5910 link = idr_find(&link_idr, id); 5911 if (link) { 5912 if (link->id) 5913 link = bpf_link_inc_not_zero(link); 5914 else 5915 link = ERR_PTR(-EAGAIN); 5916 } else { 5917 link = ERR_PTR(-ENOENT); 5918 } 5919 spin_unlock_bh(&link_idr_lock); 5920 return link; 5921 } 5922 5923 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 5924 { 5925 struct bpf_link *link; 5926 5927 spin_lock_bh(&link_idr_lock); 5928 again: 5929 link = idr_get_next(&link_idr, id); 5930 if (link) { 5931 link = bpf_link_inc_not_zero(link); 5932 if (IS_ERR(link)) { 5933 (*id)++; 5934 goto again; 5935 } 5936 } 5937 spin_unlock_bh(&link_idr_lock); 5938 5939 return link; 5940 } 5941 5942 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 5943 5944 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 5945 { 5946 struct bpf_link *link; 5947 u32 id = attr->link_id; 5948 int fd; 5949 5950 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 5951 return -EINVAL; 5952 5953 if (!capable(CAP_SYS_ADMIN)) 5954 return -EPERM; 5955 5956 link = bpf_link_by_id(id); 5957 if (IS_ERR(link)) 5958 return PTR_ERR(link); 5959 5960 fd = bpf_link_new_fd(link); 5961 if (fd < 0) 5962 bpf_link_put_direct(link); 5963 5964 return fd; 5965 } 5966 5967 DEFINE_MUTEX(bpf_stats_enabled_mutex); 5968 5969 static int bpf_stats_release(struct inode *inode, struct file *file) 5970 { 5971 mutex_lock(&bpf_stats_enabled_mutex); 5972 static_key_slow_dec(&bpf_stats_enabled_key.key); 5973 mutex_unlock(&bpf_stats_enabled_mutex); 5974 return 0; 5975 } 5976 5977 static const struct file_operations bpf_stats_fops = { 5978 .release = bpf_stats_release, 5979 }; 5980 5981 static int bpf_enable_runtime_stats(void) 5982 { 5983 int fd; 5984 5985 mutex_lock(&bpf_stats_enabled_mutex); 5986 5987 /* Set a very high limit to avoid overflow */ 5988 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 5989 mutex_unlock(&bpf_stats_enabled_mutex); 5990 return -EBUSY; 5991 } 5992 5993 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 5994 if (fd >= 0) 5995 static_key_slow_inc(&bpf_stats_enabled_key.key); 5996 5997 mutex_unlock(&bpf_stats_enabled_mutex); 5998 return fd; 5999 } 6000 6001 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 6002 6003 static int bpf_enable_stats(union bpf_attr *attr) 6004 { 6005 6006 if (CHECK_ATTR(BPF_ENABLE_STATS)) 6007 return -EINVAL; 6008 6009 if (!capable(CAP_SYS_ADMIN)) 6010 return -EPERM; 6011 6012 switch (attr->enable_stats.type) { 6013 case BPF_STATS_RUN_TIME: 6014 return bpf_enable_runtime_stats(); 6015 default: 6016 break; 6017 } 6018 return -EINVAL; 6019 } 6020 6021 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 6022 6023 static int bpf_iter_create(union bpf_attr *attr) 6024 { 6025 struct bpf_link *link; 6026 int err; 6027 6028 if (CHECK_ATTR(BPF_ITER_CREATE)) 6029 return -EINVAL; 6030 6031 if (attr->iter_create.flags) 6032 return -EINVAL; 6033 6034 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 6035 if (IS_ERR(link)) 6036 return PTR_ERR(link); 6037 6038 err = bpf_iter_new_fd(link); 6039 bpf_link_put_direct(link); 6040 6041 return err; 6042 } 6043 6044 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 6045 6046 static int bpf_prog_bind_map(union bpf_attr *attr) 6047 { 6048 struct bpf_prog *prog; 6049 struct bpf_map *map; 6050 struct bpf_map **used_maps_old, **used_maps_new; 6051 int i, ret = 0; 6052 6053 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 6054 return -EINVAL; 6055 6056 if (attr->prog_bind_map.flags) 6057 return -EINVAL; 6058 6059 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 6060 if (IS_ERR(prog)) 6061 return PTR_ERR(prog); 6062 6063 map = bpf_map_get(attr->prog_bind_map.map_fd); 6064 if (IS_ERR(map)) { 6065 ret = PTR_ERR(map); 6066 goto out_prog_put; 6067 } 6068 6069 mutex_lock(&prog->aux->used_maps_mutex); 6070 6071 used_maps_old = prog->aux->used_maps; 6072 6073 for (i = 0; i < prog->aux->used_map_cnt; i++) 6074 if (used_maps_old[i] == map) { 6075 bpf_map_put(map); 6076 goto out_unlock; 6077 } 6078 6079 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, 6080 sizeof(used_maps_new[0]), 6081 GFP_KERNEL); 6082 if (!used_maps_new) { 6083 ret = -ENOMEM; 6084 goto out_unlock; 6085 } 6086 6087 /* The bpf program will not access the bpf map, but for the sake of 6088 * simplicity, increase sleepable_refcnt for sleepable program as well. 6089 */ 6090 if (prog->sleepable) 6091 atomic64_inc(&map->sleepable_refcnt); 6092 memcpy(used_maps_new, used_maps_old, 6093 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 6094 used_maps_new[prog->aux->used_map_cnt] = map; 6095 6096 prog->aux->used_map_cnt++; 6097 prog->aux->used_maps = used_maps_new; 6098 6099 kfree(used_maps_old); 6100 6101 out_unlock: 6102 mutex_unlock(&prog->aux->used_maps_mutex); 6103 6104 if (ret) 6105 bpf_map_put(map); 6106 out_prog_put: 6107 bpf_prog_put(prog); 6108 return ret; 6109 } 6110 6111 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 6112 6113 static int token_create(union bpf_attr *attr) 6114 { 6115 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 6116 return -EINVAL; 6117 6118 /* no flags are supported yet */ 6119 if (attr->token_create.flags) 6120 return -EINVAL; 6121 6122 return bpf_token_create(attr); 6123 } 6124 6125 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd 6126 6127 static int prog_stream_read(union bpf_attr *attr) 6128 { 6129 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); 6130 u32 len = attr->prog_stream_read.stream_buf_len; 6131 struct bpf_prog *prog; 6132 int ret; 6133 6134 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) 6135 return -EINVAL; 6136 6137 prog = bpf_prog_get(attr->prog_stream_read.prog_fd); 6138 if (IS_ERR(prog)) 6139 return PTR_ERR(prog); 6140 6141 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); 6142 bpf_prog_put(prog); 6143 6144 return ret; 6145 } 6146 6147 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.prog_fd 6148 6149 static int prog_assoc_struct_ops(union bpf_attr *attr) 6150 { 6151 struct bpf_prog *prog; 6152 struct bpf_map *map; 6153 int ret; 6154 6155 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS)) 6156 return -EINVAL; 6157 6158 if (attr->prog_assoc_struct_ops.flags) 6159 return -EINVAL; 6160 6161 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd); 6162 if (IS_ERR(prog)) 6163 return PTR_ERR(prog); 6164 6165 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) { 6166 ret = -EINVAL; 6167 goto put_prog; 6168 } 6169 6170 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd); 6171 if (IS_ERR(map)) { 6172 ret = PTR_ERR(map); 6173 goto put_prog; 6174 } 6175 6176 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 6177 ret = -EINVAL; 6178 goto put_map; 6179 } 6180 6181 ret = bpf_prog_assoc_struct_ops(prog, map); 6182 6183 put_map: 6184 bpf_map_put(map); 6185 put_prog: 6186 bpf_prog_put(prog); 6187 return ret; 6188 } 6189 6190 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size) 6191 { 6192 union bpf_attr attr; 6193 int err; 6194 6195 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 6196 if (err) 6197 return err; 6198 size = min_t(u32, size, sizeof(attr)); 6199 6200 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 6201 memset(&attr, 0, sizeof(attr)); 6202 if (copy_from_bpfptr(&attr, uattr, size) != 0) 6203 return -EFAULT; 6204 6205 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 6206 if (err < 0) 6207 return err; 6208 6209 switch (cmd) { 6210 case BPF_MAP_CREATE: 6211 err = map_create(&attr, uattr); 6212 break; 6213 case BPF_MAP_LOOKUP_ELEM: 6214 err = map_lookup_elem(&attr); 6215 break; 6216 case BPF_MAP_UPDATE_ELEM: 6217 err = map_update_elem(&attr, uattr); 6218 break; 6219 case BPF_MAP_DELETE_ELEM: 6220 err = map_delete_elem(&attr, uattr); 6221 break; 6222 case BPF_MAP_GET_NEXT_KEY: 6223 err = map_get_next_key(&attr); 6224 break; 6225 case BPF_MAP_FREEZE: 6226 err = map_freeze(&attr); 6227 break; 6228 case BPF_PROG_LOAD: 6229 err = bpf_prog_load(&attr, uattr, size); 6230 break; 6231 case BPF_OBJ_PIN: 6232 err = bpf_obj_pin(&attr); 6233 break; 6234 case BPF_OBJ_GET: 6235 err = bpf_obj_get(&attr); 6236 break; 6237 case BPF_PROG_ATTACH: 6238 err = bpf_prog_attach(&attr); 6239 break; 6240 case BPF_PROG_DETACH: 6241 err = bpf_prog_detach(&attr); 6242 break; 6243 case BPF_PROG_QUERY: 6244 err = bpf_prog_query(&attr, uattr.user); 6245 break; 6246 case BPF_PROG_TEST_RUN: 6247 err = bpf_prog_test_run(&attr, uattr.user); 6248 break; 6249 case BPF_PROG_GET_NEXT_ID: 6250 err = bpf_obj_get_next_id(&attr, uattr.user, 6251 &prog_idr, &prog_idr_lock); 6252 break; 6253 case BPF_MAP_GET_NEXT_ID: 6254 err = bpf_obj_get_next_id(&attr, uattr.user, 6255 &map_idr, &map_idr_lock); 6256 break; 6257 case BPF_BTF_GET_NEXT_ID: 6258 err = bpf_obj_get_next_id(&attr, uattr.user, 6259 &btf_idr, &btf_idr_lock); 6260 break; 6261 case BPF_PROG_GET_FD_BY_ID: 6262 err = bpf_prog_get_fd_by_id(&attr); 6263 break; 6264 case BPF_MAP_GET_FD_BY_ID: 6265 err = bpf_map_get_fd_by_id(&attr); 6266 break; 6267 case BPF_OBJ_GET_INFO_BY_FD: 6268 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 6269 break; 6270 case BPF_RAW_TRACEPOINT_OPEN: 6271 err = bpf_raw_tracepoint_open(&attr); 6272 break; 6273 case BPF_BTF_LOAD: 6274 err = bpf_btf_load(&attr, uattr, size); 6275 break; 6276 case BPF_BTF_GET_FD_BY_ID: 6277 err = bpf_btf_get_fd_by_id(&attr); 6278 break; 6279 case BPF_TASK_FD_QUERY: 6280 err = bpf_task_fd_query(&attr, uattr.user); 6281 break; 6282 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 6283 err = map_lookup_and_delete_elem(&attr); 6284 break; 6285 case BPF_MAP_LOOKUP_BATCH: 6286 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 6287 break; 6288 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 6289 err = bpf_map_do_batch(&attr, uattr.user, 6290 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 6291 break; 6292 case BPF_MAP_UPDATE_BATCH: 6293 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 6294 break; 6295 case BPF_MAP_DELETE_BATCH: 6296 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 6297 break; 6298 case BPF_LINK_CREATE: 6299 err = link_create(&attr, uattr); 6300 break; 6301 case BPF_LINK_UPDATE: 6302 err = link_update(&attr); 6303 break; 6304 case BPF_LINK_GET_FD_BY_ID: 6305 err = bpf_link_get_fd_by_id(&attr); 6306 break; 6307 case BPF_LINK_GET_NEXT_ID: 6308 err = bpf_obj_get_next_id(&attr, uattr.user, 6309 &link_idr, &link_idr_lock); 6310 break; 6311 case BPF_ENABLE_STATS: 6312 err = bpf_enable_stats(&attr); 6313 break; 6314 case BPF_ITER_CREATE: 6315 err = bpf_iter_create(&attr); 6316 break; 6317 case BPF_LINK_DETACH: 6318 err = link_detach(&attr); 6319 break; 6320 case BPF_PROG_BIND_MAP: 6321 err = bpf_prog_bind_map(&attr); 6322 break; 6323 case BPF_TOKEN_CREATE: 6324 err = token_create(&attr); 6325 break; 6326 case BPF_PROG_STREAM_READ_BY_FD: 6327 err = prog_stream_read(&attr); 6328 break; 6329 case BPF_PROG_ASSOC_STRUCT_OPS: 6330 err = prog_assoc_struct_ops(&attr); 6331 break; 6332 default: 6333 err = -EINVAL; 6334 break; 6335 } 6336 6337 return err; 6338 } 6339 6340 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) 6341 { 6342 return __sys_bpf(cmd, USER_BPFPTR(uattr), size); 6343 } 6344 6345 static bool syscall_prog_is_valid_access(int off, int size, 6346 enum bpf_access_type type, 6347 const struct bpf_prog *prog, 6348 struct bpf_insn_access_aux *info) 6349 { 6350 if (off < 0 || off >= U16_MAX) 6351 return false; 6352 if (off % size != 0) 6353 return false; 6354 return true; 6355 } 6356 6357 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 6358 { 6359 switch (cmd) { 6360 case BPF_MAP_CREATE: 6361 case BPF_MAP_DELETE_ELEM: 6362 case BPF_MAP_UPDATE_ELEM: 6363 case BPF_MAP_FREEZE: 6364 case BPF_MAP_GET_FD_BY_ID: 6365 case BPF_PROG_LOAD: 6366 case BPF_BTF_LOAD: 6367 case BPF_LINK_CREATE: 6368 case BPF_RAW_TRACEPOINT_OPEN: 6369 break; 6370 default: 6371 return -EINVAL; 6372 } 6373 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); 6374 } 6375 6376 6377 /* To shut up -Wmissing-prototypes. 6378 * This function is used by the kernel light skeleton 6379 * to load bpf programs when modules are loaded or during kernel boot. 6380 * See tools/lib/bpf/skel_internal.h 6381 */ 6382 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 6383 6384 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 6385 { 6386 struct bpf_prog * __maybe_unused prog; 6387 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 6388 6389 switch (cmd) { 6390 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 6391 case BPF_PROG_TEST_RUN: 6392 if (attr->test.data_in || attr->test.data_out || 6393 attr->test.ctx_out || attr->test.duration || 6394 attr->test.repeat || attr->test.flags) 6395 return -EINVAL; 6396 6397 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 6398 if (IS_ERR(prog)) 6399 return PTR_ERR(prog); 6400 6401 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 6402 attr->test.ctx_size_in > U16_MAX) { 6403 bpf_prog_put(prog); 6404 return -EINVAL; 6405 } 6406 6407 run_ctx.bpf_cookie = 0; 6408 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 6409 /* recursion detected */ 6410 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 6411 bpf_prog_put(prog); 6412 return -EBUSY; 6413 } 6414 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 6415 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 6416 &run_ctx); 6417 bpf_prog_put(prog); 6418 return 0; 6419 #endif 6420 default: 6421 return ____bpf_sys_bpf(cmd, attr, size); 6422 } 6423 } 6424 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); 6425 6426 static const struct bpf_func_proto bpf_sys_bpf_proto = { 6427 .func = bpf_sys_bpf, 6428 .gpl_only = false, 6429 .ret_type = RET_INTEGER, 6430 .arg1_type = ARG_ANYTHING, 6431 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6432 .arg3_type = ARG_CONST_SIZE, 6433 }; 6434 6435 const struct bpf_func_proto * __weak 6436 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6437 { 6438 return bpf_base_func_proto(func_id, prog); 6439 } 6440 6441 BPF_CALL_1(bpf_sys_close, u32, fd) 6442 { 6443 /* When bpf program calls this helper there should not be 6444 * an fdget() without matching completed fdput(). 6445 * This helper is allowed in the following callchain only: 6446 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6447 */ 6448 return close_fd(fd); 6449 } 6450 6451 static const struct bpf_func_proto bpf_sys_close_proto = { 6452 .func = bpf_sys_close, 6453 .gpl_only = false, 6454 .ret_type = RET_INTEGER, 6455 .arg1_type = ARG_ANYTHING, 6456 }; 6457 6458 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6459 { 6460 *res = 0; 6461 if (flags) 6462 return -EINVAL; 6463 6464 if (name_sz <= 1 || name[name_sz - 1]) 6465 return -EINVAL; 6466 6467 if (!bpf_dump_raw_ok(current_cred())) 6468 return -EPERM; 6469 6470 *res = kallsyms_lookup_name(name); 6471 return *res ? 0 : -ENOENT; 6472 } 6473 6474 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6475 .func = bpf_kallsyms_lookup_name, 6476 .gpl_only = false, 6477 .ret_type = RET_INTEGER, 6478 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6479 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 6480 .arg3_type = ARG_ANYTHING, 6481 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6482 .arg4_size = sizeof(u64), 6483 }; 6484 6485 static const struct bpf_func_proto * 6486 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6487 { 6488 switch (func_id) { 6489 case BPF_FUNC_sys_bpf: 6490 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6491 ? NULL : &bpf_sys_bpf_proto; 6492 case BPF_FUNC_btf_find_by_name_kind: 6493 return &bpf_btf_find_by_name_kind_proto; 6494 case BPF_FUNC_sys_close: 6495 return &bpf_sys_close_proto; 6496 case BPF_FUNC_kallsyms_lookup_name: 6497 return &bpf_kallsyms_lookup_name_proto; 6498 default: 6499 return tracing_prog_func_proto(func_id, prog); 6500 } 6501 } 6502 6503 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6504 .get_func_proto = syscall_prog_func_proto, 6505 .is_valid_access = syscall_prog_is_valid_access, 6506 }; 6507 6508 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6509 .test_run = bpf_prog_test_run_syscall, 6510 }; 6511 6512 #ifdef CONFIG_SYSCTL 6513 static int bpf_stats_handler(const struct ctl_table *table, int write, 6514 void *buffer, size_t *lenp, loff_t *ppos) 6515 { 6516 struct static_key *key = (struct static_key *)table->data; 6517 static int saved_val; 6518 int val, ret; 6519 struct ctl_table tmp = { 6520 .data = &val, 6521 .maxlen = sizeof(val), 6522 .mode = table->mode, 6523 .extra1 = SYSCTL_ZERO, 6524 .extra2 = SYSCTL_ONE, 6525 }; 6526 6527 if (write && !capable(CAP_SYS_ADMIN)) 6528 return -EPERM; 6529 6530 mutex_lock(&bpf_stats_enabled_mutex); 6531 val = saved_val; 6532 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6533 if (write && !ret && val != saved_val) { 6534 if (val) 6535 static_key_slow_inc(key); 6536 else 6537 static_key_slow_dec(key); 6538 saved_val = val; 6539 } 6540 mutex_unlock(&bpf_stats_enabled_mutex); 6541 return ret; 6542 } 6543 6544 void __weak unpriv_ebpf_notify(int new_state) 6545 { 6546 } 6547 6548 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6549 void *buffer, size_t *lenp, loff_t *ppos) 6550 { 6551 int ret, unpriv_enable = *(int *)table->data; 6552 bool locked_state = unpriv_enable == 1; 6553 struct ctl_table tmp = *table; 6554 6555 if (write && !capable(CAP_SYS_ADMIN)) 6556 return -EPERM; 6557 6558 tmp.data = &unpriv_enable; 6559 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6560 if (write && !ret) { 6561 if (locked_state && unpriv_enable != 1) 6562 return -EPERM; 6563 *(int *)table->data = unpriv_enable; 6564 } 6565 6566 if (write) 6567 unpriv_ebpf_notify(unpriv_enable); 6568 6569 return ret; 6570 } 6571 6572 static const struct ctl_table bpf_syscall_table[] = { 6573 { 6574 .procname = "unprivileged_bpf_disabled", 6575 .data = &sysctl_unprivileged_bpf_disabled, 6576 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6577 .mode = 0644, 6578 .proc_handler = bpf_unpriv_handler, 6579 .extra1 = SYSCTL_ZERO, 6580 .extra2 = SYSCTL_TWO, 6581 }, 6582 { 6583 .procname = "bpf_stats_enabled", 6584 .data = &bpf_stats_enabled_key.key, 6585 .mode = 0644, 6586 .proc_handler = bpf_stats_handler, 6587 }, 6588 }; 6589 6590 static int __init bpf_syscall_sysctl_init(void) 6591 { 6592 register_sysctl_init("kernel", bpf_syscall_table); 6593 return 0; 6594 } 6595 late_initcall(bpf_syscall_sysctl_init); 6596 #endif /* CONFIG_SYSCTL */ 6597