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/btf_ids.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 static int btf_field_cmp(const void *a, const void *b) 640 { 641 const struct btf_field *f1 = a, *f2 = b; 642 643 if (f1->offset < f2->offset) 644 return -1; 645 else if (f1->offset > f2->offset) 646 return 1; 647 return 0; 648 } 649 650 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 651 u32 field_mask) 652 { 653 struct btf_field *field; 654 655 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 656 return NULL; 657 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 658 if (!field || !(field->type & field_mask)) 659 return NULL; 660 return field; 661 } 662 663 void btf_record_free(struct btf_record *rec) 664 { 665 int i; 666 667 if (IS_ERR_OR_NULL(rec)) 668 return; 669 for (i = 0; i < rec->cnt; i++) { 670 switch (rec->fields[i].type) { 671 case BPF_KPTR_UNREF: 672 case BPF_KPTR_REF: 673 case BPF_KPTR_PERCPU: 674 case BPF_UPTR: 675 if (rec->fields[i].kptr.module) 676 module_put(rec->fields[i].kptr.module); 677 if (btf_is_kernel(rec->fields[i].kptr.btf)) 678 btf_put(rec->fields[i].kptr.btf); 679 break; 680 case BPF_LIST_HEAD: 681 case BPF_LIST_NODE: 682 case BPF_RB_ROOT: 683 case BPF_RB_NODE: 684 case BPF_SPIN_LOCK: 685 case BPF_RES_SPIN_LOCK: 686 case BPF_TIMER: 687 case BPF_REFCOUNT: 688 case BPF_WORKQUEUE: 689 case BPF_TASK_WORK: 690 /* Nothing to release */ 691 break; 692 default: 693 WARN_ON_ONCE(1); 694 continue; 695 } 696 } 697 kfree(rec); 698 } 699 700 void bpf_map_free_record(struct bpf_map *map) 701 { 702 btf_record_free(map->record); 703 map->record = NULL; 704 } 705 706 struct btf_record *btf_record_dup(const struct btf_record *rec) 707 { 708 const struct btf_field *fields; 709 struct btf_record *new_rec; 710 int ret, size, i; 711 712 if (IS_ERR_OR_NULL(rec)) 713 return NULL; 714 size = struct_size(rec, fields, rec->cnt); 715 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 716 if (!new_rec) 717 return ERR_PTR(-ENOMEM); 718 /* Do a deep copy of the btf_record */ 719 fields = rec->fields; 720 new_rec->cnt = 0; 721 for (i = 0; i < rec->cnt; i++) { 722 switch (fields[i].type) { 723 case BPF_KPTR_UNREF: 724 case BPF_KPTR_REF: 725 case BPF_KPTR_PERCPU: 726 case BPF_UPTR: 727 if (btf_is_kernel(fields[i].kptr.btf)) 728 btf_get(fields[i].kptr.btf); 729 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 730 ret = -ENXIO; 731 goto free; 732 } 733 break; 734 case BPF_LIST_HEAD: 735 case BPF_LIST_NODE: 736 case BPF_RB_ROOT: 737 case BPF_RB_NODE: 738 case BPF_SPIN_LOCK: 739 case BPF_RES_SPIN_LOCK: 740 case BPF_TIMER: 741 case BPF_REFCOUNT: 742 case BPF_WORKQUEUE: 743 case BPF_TASK_WORK: 744 /* Nothing to acquire */ 745 break; 746 default: 747 ret = -EFAULT; 748 WARN_ON_ONCE(1); 749 goto free; 750 } 751 new_rec->cnt++; 752 } 753 return new_rec; 754 free: 755 btf_record_free(new_rec); 756 return ERR_PTR(ret); 757 } 758 759 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 760 { 761 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 762 int size; 763 764 if (!a_has_fields && !b_has_fields) 765 return true; 766 if (a_has_fields != b_has_fields) 767 return false; 768 if (rec_a->cnt != rec_b->cnt) 769 return false; 770 size = struct_size(rec_a, fields, rec_a->cnt); 771 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 772 * members are zeroed out. So memcmp is safe to do without worrying 773 * about padding/unused fields. 774 * 775 * While spin_lock, timer, and kptr have no relation to map BTF, 776 * list_head metadata is specific to map BTF, the btf and value_rec 777 * members in particular. btf is the map BTF, while value_rec points to 778 * btf_record in that map BTF. 779 * 780 * So while by default, we don't rely on the map BTF (which the records 781 * were parsed from) matching for both records, which is not backwards 782 * compatible, in case list_head is part of it, we implicitly rely on 783 * that by way of depending on memcmp succeeding for it. 784 */ 785 return !memcmp(rec_a, rec_b, size); 786 } 787 788 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 789 { 790 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 791 return; 792 bpf_timer_cancel_and_free(obj + rec->timer_off); 793 } 794 795 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj) 796 { 797 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE))) 798 return; 799 bpf_wq_cancel_and_free(obj + rec->wq_off); 800 } 801 802 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj) 803 { 804 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK))) 805 return; 806 bpf_task_work_cancel_and_free(obj + rec->task_work_off); 807 } 808 809 void bpf_obj_cancel_fields(struct bpf_map *map, void *obj) 810 { 811 bpf_map_free_internal_structs(map, obj); 812 } 813 814 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 815 { 816 const struct btf_field *fields; 817 int i; 818 819 if (IS_ERR_OR_NULL(rec)) 820 return; 821 fields = rec->fields; 822 for (i = 0; i < rec->cnt; i++) { 823 struct btf_struct_meta *pointee_struct_meta; 824 const struct btf_field *field = &fields[i]; 825 void *field_ptr = obj + field->offset; 826 void *xchgd_field; 827 828 switch (fields[i].type) { 829 case BPF_SPIN_LOCK: 830 case BPF_RES_SPIN_LOCK: 831 break; 832 case BPF_TIMER: 833 bpf_timer_cancel_and_free(field_ptr); 834 break; 835 case BPF_WORKQUEUE: 836 bpf_wq_cancel_and_free(field_ptr); 837 break; 838 case BPF_TASK_WORK: 839 bpf_task_work_cancel_and_free(field_ptr); 840 break; 841 case BPF_KPTR_UNREF: 842 WRITE_ONCE(*(u64 *)field_ptr, 0); 843 break; 844 case BPF_KPTR_REF: 845 case BPF_KPTR_PERCPU: 846 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); 847 if (!xchgd_field) 848 break; 849 850 if (!btf_is_kernel(field->kptr.btf)) { 851 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, 852 field->kptr.btf_id); 853 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? 854 pointee_struct_meta->record : NULL, 855 fields[i].type == BPF_KPTR_PERCPU); 856 } else { 857 field->kptr.dtor(xchgd_field); 858 } 859 break; 860 case BPF_UPTR: 861 /* The caller ensured that no one is using the uptr */ 862 unpin_uptr_kaddr(*(void **)field_ptr); 863 break; 864 case BPF_LIST_HEAD: 865 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 866 continue; 867 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 868 break; 869 case BPF_RB_ROOT: 870 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 871 continue; 872 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); 873 break; 874 case BPF_LIST_NODE: 875 case BPF_RB_NODE: 876 case BPF_REFCOUNT: 877 break; 878 default: 879 WARN_ON_ONCE(1); 880 continue; 881 } 882 } 883 } 884 885 static void bpf_map_free(struct bpf_map *map) 886 { 887 struct btf_record *rec = map->record; 888 struct btf *btf = map->btf; 889 890 /* implementation dependent freeing. Disabling migration to simplify 891 * the free of values or special fields allocated from bpf memory 892 * allocator. 893 */ 894 kfree(map->excl_prog_sha); 895 migrate_disable(); 896 map->ops->map_free(map); 897 migrate_enable(); 898 899 /* Delay freeing of btf_record for maps, as map_free 900 * callback usually needs access to them. It is better to do it here 901 * than require each callback to do the free itself manually. 902 * 903 * Note that the btf_record stashed in map->inner_map_meta->record was 904 * already freed using the map_free callback for map in map case which 905 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 906 * template bpf_map struct used during verification. 907 */ 908 btf_record_free(rec); 909 /* Delay freeing of btf for maps, as map_free callback may need 910 * struct_meta info which will be freed with btf_put(). 911 */ 912 btf_put(btf); 913 } 914 915 /* called from workqueue */ 916 static void bpf_map_free_deferred(struct work_struct *work) 917 { 918 struct bpf_map *map = container_of(work, struct bpf_map, work); 919 920 security_bpf_map_free(map); 921 bpf_map_release_memcg(map); 922 bpf_map_owner_free(map); 923 bpf_map_free(map); 924 } 925 926 static void bpf_map_put_uref(struct bpf_map *map) 927 { 928 if (atomic64_dec_and_test(&map->usercnt)) { 929 if (map->ops->map_release_uref) 930 map->ops->map_release_uref(map); 931 } 932 } 933 934 static void bpf_map_free_in_work(struct bpf_map *map) 935 { 936 INIT_WORK(&map->work, bpf_map_free_deferred); 937 /* Avoid spawning kworkers, since they all might contend 938 * for the same mutex like slab_mutex. 939 */ 940 queue_work(system_dfl_wq, &map->work); 941 } 942 943 static void bpf_map_free_rcu_gp(struct rcu_head *rcu) 944 { 945 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); 946 } 947 948 /* decrement map refcnt and schedule it for freeing via workqueue 949 * (underlying map implementation ops->map_free() might sleep) 950 */ 951 void bpf_map_put(struct bpf_map *map) 952 { 953 if (atomic64_dec_and_test(&map->refcnt)) { 954 /* bpf_map_free_id() must be called first */ 955 bpf_map_free_id(map); 956 957 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); 958 /* RCU tasks trace grace period implies RCU grace period. */ 959 if (READ_ONCE(map->free_after_mult_rcu_gp)) 960 call_rcu_tasks_trace(&map->rcu, bpf_map_free_rcu_gp); 961 else if (READ_ONCE(map->free_after_rcu_gp)) 962 call_rcu(&map->rcu, bpf_map_free_rcu_gp); 963 else 964 bpf_map_free_in_work(map); 965 } 966 } 967 EXPORT_SYMBOL_GPL(bpf_map_put); 968 969 void bpf_map_put_with_uref(struct bpf_map *map) 970 { 971 bpf_map_put_uref(map); 972 bpf_map_put(map); 973 } 974 975 static int bpf_map_release(struct inode *inode, struct file *filp) 976 { 977 struct bpf_map *map = filp->private_data; 978 979 if (map->ops->map_release) 980 map->ops->map_release(map, filp); 981 982 bpf_map_put_with_uref(map); 983 return 0; 984 } 985 986 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 987 { 988 fmode_t mode = fd_file(f)->f_mode; 989 990 /* Our file permissions may have been overridden by global 991 * map permissions facing syscall side. 992 */ 993 if (READ_ONCE(map->frozen)) 994 mode &= ~FMODE_CAN_WRITE; 995 return mode; 996 } 997 998 #ifdef CONFIG_PROC_FS 999 /* Show the memory usage of a bpf map */ 1000 static u64 bpf_map_memory_usage(const struct bpf_map *map) 1001 { 1002 return map->ops->map_mem_usage(map); 1003 } 1004 1005 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 1006 { 1007 struct bpf_map *map = filp->private_data; 1008 u32 type = 0, jited = 0; 1009 1010 spin_lock(&map->owner_lock); 1011 if (map->owner) { 1012 type = map->owner->type; 1013 jited = map->owner->jited; 1014 } 1015 spin_unlock(&map->owner_lock); 1016 1017 seq_printf(m, 1018 "map_type:\t%u\n" 1019 "key_size:\t%u\n" 1020 "value_size:\t%u\n" 1021 "max_entries:\t%u\n" 1022 "map_flags:\t%#x\n" 1023 "map_extra:\t%#llx\n" 1024 "memlock:\t%llu\n" 1025 "map_id:\t%u\n" 1026 "frozen:\t%u\n", 1027 map->map_type, 1028 map->key_size, 1029 map->value_size, 1030 map->max_entries, 1031 map->map_flags, 1032 (unsigned long long)map->map_extra, 1033 bpf_map_memory_usage(map), 1034 map->id, 1035 READ_ONCE(map->frozen)); 1036 if (type) { 1037 seq_printf(m, "owner_prog_type:\t%u\n", type); 1038 seq_printf(m, "owner_jited:\t%u\n", jited); 1039 } 1040 } 1041 #endif 1042 1043 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 1044 loff_t *ppos) 1045 { 1046 /* We need this handler such that alloc_file() enables 1047 * f_mode with FMODE_CAN_READ. 1048 */ 1049 return -EINVAL; 1050 } 1051 1052 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 1053 size_t siz, loff_t *ppos) 1054 { 1055 /* We need this handler such that alloc_file() enables 1056 * f_mode with FMODE_CAN_WRITE. 1057 */ 1058 return -EINVAL; 1059 } 1060 1061 /* called for any extra memory-mapped regions (except initial) */ 1062 static void bpf_map_mmap_open(struct vm_area_struct *vma) 1063 { 1064 struct bpf_map *map = vma->vm_file->private_data; 1065 1066 if (vma->vm_flags & VM_MAYWRITE) 1067 bpf_map_write_active_inc(map); 1068 } 1069 1070 /* called for all unmapped memory region (including initial) */ 1071 static void bpf_map_mmap_close(struct vm_area_struct *vma) 1072 { 1073 struct bpf_map *map = vma->vm_file->private_data; 1074 1075 if (vma->vm_flags & VM_MAYWRITE) 1076 bpf_map_write_active_dec(map); 1077 } 1078 1079 static vm_fault_t bpf_map_mmap_fault(struct vm_fault *vmf) 1080 { 1081 struct bpf_map *map = vmf->vma->vm_private_data; 1082 1083 return map->ops->map_mmap_fault(map, vmf); 1084 } 1085 1086 static const struct vm_operations_struct bpf_map_default_vmops = { 1087 .open = bpf_map_mmap_open, 1088 .close = bpf_map_mmap_close, 1089 }; 1090 1091 static const struct vm_operations_struct bpf_map_lazy_vmops = { 1092 .open = bpf_map_mmap_open, 1093 .close = bpf_map_mmap_close, 1094 .fault = bpf_map_mmap_fault, 1095 }; 1096 1097 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 1098 { 1099 struct bpf_map *map = filp->private_data; 1100 int err = 0; 1101 1102 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 1103 return -ENOTSUPP; 1104 1105 if (!(vma->vm_flags & VM_SHARED)) 1106 return -EINVAL; 1107 1108 mutex_lock(&map->freeze_mutex); 1109 1110 if (vma->vm_flags & VM_WRITE) { 1111 if (map->frozen) { 1112 err = -EPERM; 1113 goto out; 1114 } 1115 /* map is meant to be read-only, so do not allow mapping as 1116 * writable, because it's possible to leak a writable page 1117 * reference and allows user-space to still modify it after 1118 * freezing, while verifier will assume contents do not change 1119 */ 1120 if (map->map_flags & BPF_F_RDONLY_PROG) { 1121 err = -EACCES; 1122 goto out; 1123 } 1124 bpf_map_write_active_inc(map); 1125 } 1126 out: 1127 mutex_unlock(&map->freeze_mutex); 1128 if (err) 1129 return err; 1130 1131 /* set default open/close callbacks */ 1132 vma->vm_ops = map->ops->map_mmap_fault ? &bpf_map_lazy_vmops : &bpf_map_default_vmops; 1133 vma->vm_private_data = map; 1134 vm_flags_clear(vma, VM_MAYEXEC); 1135 /* If mapping is read-only, then disallow potentially re-mapping with 1136 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing 1137 * means that as far as BPF map's memory-mapped VMAs are concerned, 1138 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set, 1139 * both should be set, so we can forget about VM_MAYWRITE and always 1140 * check just VM_WRITE 1141 */ 1142 if (!(vma->vm_flags & VM_WRITE)) 1143 vm_flags_clear(vma, VM_MAYWRITE); 1144 1145 err = map->ops->map_mmap(map, vma); 1146 if (err) { 1147 if (vma->vm_flags & VM_WRITE) 1148 bpf_map_write_active_dec(map); 1149 } 1150 1151 return err; 1152 } 1153 1154 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 1155 { 1156 struct bpf_map *map = filp->private_data; 1157 1158 if (map->ops->map_poll) 1159 return map->ops->map_poll(map, filp, pts); 1160 1161 return EPOLLERR; 1162 } 1163 1164 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr, 1165 unsigned long len, unsigned long pgoff, 1166 unsigned long flags) 1167 { 1168 struct bpf_map *map = filp->private_data; 1169 1170 if (map->ops->map_get_unmapped_area) 1171 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); 1172 #ifdef CONFIG_MMU 1173 return mm_get_unmapped_area(filp, addr, len, pgoff, flags); 1174 #else 1175 return addr; 1176 #endif 1177 } 1178 1179 const struct file_operations bpf_map_fops = { 1180 #ifdef CONFIG_PROC_FS 1181 .show_fdinfo = bpf_map_show_fdinfo, 1182 #endif 1183 .release = bpf_map_release, 1184 .read = bpf_dummy_read, 1185 .write = bpf_dummy_write, 1186 .mmap = bpf_map_mmap, 1187 .poll = bpf_map_poll, 1188 .get_unmapped_area = bpf_get_unmapped_area, 1189 }; 1190 1191 int bpf_map_new_fd(struct bpf_map *map, int flags) 1192 { 1193 int ret; 1194 1195 ret = security_bpf_map(map, OPEN_FMODE(flags)); 1196 if (ret < 0) 1197 return ret; 1198 1199 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 1200 flags | O_CLOEXEC); 1201 } 1202 1203 int bpf_get_file_flag(int flags) 1204 { 1205 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 1206 return -EINVAL; 1207 if (flags & BPF_F_RDONLY) 1208 return O_RDONLY; 1209 if (flags & BPF_F_WRONLY) 1210 return O_WRONLY; 1211 return O_RDWR; 1212 } 1213 1214 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 1215 #define CHECK_ATTR(CMD) \ 1216 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 1217 sizeof(attr->CMD##_LAST_FIELD), 0, \ 1218 sizeof(*attr) - \ 1219 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 1220 sizeof(attr->CMD##_LAST_FIELD)) != NULL 1221 1222 /* dst and src must have at least "size" number of bytes. 1223 * Return strlen on success and < 0 on error. 1224 */ 1225 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 1226 { 1227 const char *end = src + size; 1228 const char *orig_src = src; 1229 1230 memset(dst, 0, size); 1231 /* Copy all isalnum(), '_' and '.' chars. */ 1232 while (src < end && *src) { 1233 if (!isalnum(*src) && 1234 *src != '_' && *src != '.') 1235 return -EINVAL; 1236 *dst++ = *src++; 1237 } 1238 1239 /* No '\0' found in "size" number of bytes */ 1240 if (src == end) 1241 return -EINVAL; 1242 1243 return src - orig_src; 1244 } 1245 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy); 1246 1247 int map_check_no_btf(struct bpf_map *map, 1248 const struct btf *btf, 1249 const struct btf_type *key_type, 1250 const struct btf_type *value_type) 1251 { 1252 return -ENOTSUPP; 1253 } 1254 1255 static int map_check_btf(struct bpf_map *map, struct bpf_token *token, 1256 const struct btf *btf, u32 btf_key_id, u32 btf_value_id) 1257 { 1258 const struct btf_type *key_type, *value_type; 1259 u32 key_size, value_size; 1260 int ret = 0; 1261 1262 /* Some maps allow key to be unspecified. */ 1263 if (btf_key_id) { 1264 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 1265 if (!key_type || key_size != map->key_size) 1266 return -EINVAL; 1267 } else { 1268 key_type = btf_type_by_id(btf, 0); 1269 if (!map->ops->map_check_btf) 1270 return -EINVAL; 1271 } 1272 1273 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1274 if (!value_type || value_size != map->value_size) 1275 return -EINVAL; 1276 1277 map->record = btf_parse_fields(btf, value_type, 1278 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1279 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR | 1280 BPF_TASK_WORK, 1281 map->value_size); 1282 if (!IS_ERR_OR_NULL(map->record)) { 1283 int i; 1284 1285 if (!bpf_token_capable(token, CAP_BPF)) { 1286 ret = -EPERM; 1287 goto free_map_tab; 1288 } 1289 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1290 ret = -EACCES; 1291 goto free_map_tab; 1292 } 1293 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1294 switch (map->record->field_mask & (1 << i)) { 1295 case 0: 1296 continue; 1297 case BPF_SPIN_LOCK: 1298 case BPF_RES_SPIN_LOCK: 1299 if (map->map_type != BPF_MAP_TYPE_HASH && 1300 map->map_type != BPF_MAP_TYPE_RHASH && 1301 map->map_type != BPF_MAP_TYPE_ARRAY && 1302 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1303 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1304 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1305 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1306 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1307 ret = -EOPNOTSUPP; 1308 goto free_map_tab; 1309 } 1310 break; 1311 case BPF_TIMER: 1312 case BPF_WORKQUEUE: 1313 case BPF_TASK_WORK: 1314 if (map->map_type != BPF_MAP_TYPE_HASH && 1315 map->map_type != BPF_MAP_TYPE_RHASH && 1316 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1317 map->map_type != BPF_MAP_TYPE_ARRAY) { 1318 ret = -EOPNOTSUPP; 1319 goto free_map_tab; 1320 } 1321 break; 1322 case BPF_KPTR_UNREF: 1323 case BPF_KPTR_REF: 1324 case BPF_KPTR_PERCPU: 1325 case BPF_REFCOUNT: 1326 if (map->map_type != BPF_MAP_TYPE_HASH && 1327 map->map_type != BPF_MAP_TYPE_RHASH && 1328 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1329 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1330 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1331 map->map_type != BPF_MAP_TYPE_ARRAY && 1332 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1333 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1334 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1335 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1336 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1337 ret = -EOPNOTSUPP; 1338 goto free_map_tab; 1339 } 1340 break; 1341 case BPF_UPTR: 1342 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { 1343 ret = -EOPNOTSUPP; 1344 goto free_map_tab; 1345 } 1346 break; 1347 case BPF_LIST_HEAD: 1348 case BPF_RB_ROOT: 1349 if (map->map_type != BPF_MAP_TYPE_HASH && 1350 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1351 map->map_type != BPF_MAP_TYPE_ARRAY) { 1352 ret = -EOPNOTSUPP; 1353 goto free_map_tab; 1354 } 1355 break; 1356 default: 1357 /* Fail if map_type checks are missing for a field type */ 1358 ret = -EOPNOTSUPP; 1359 goto free_map_tab; 1360 } 1361 } 1362 } 1363 1364 ret = btf_check_and_fixup_fields(btf, map->record); 1365 if (ret < 0) 1366 goto free_map_tab; 1367 1368 if (map->ops->map_check_btf) { 1369 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1370 if (ret < 0) 1371 goto free_map_tab; 1372 } 1373 1374 return ret; 1375 free_map_tab: 1376 bpf_map_free_record(map); 1377 return ret; 1378 } 1379 1380 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size 1381 /* called via syscall */ 1382 static int map_create_alloc(union bpf_attr *attr, bpfptr_t uattr, struct bpf_verifier_log *log, 1383 struct bpf_map **mapp, struct bpf_token **tokenp) 1384 { 1385 const struct bpf_map_ops *ops; 1386 struct bpf_token *token = NULL; 1387 int numa_node = bpf_map_attr_numa_node(attr); 1388 u32 map_type = attr->map_type; 1389 struct bpf_map *map; 1390 bool token_flag; 1391 int err; 1392 1393 err = CHECK_ATTR(BPF_MAP_CREATE); 1394 if (err) { 1395 bpf_log(log, "Invalid attr.\n"); 1396 return -EINVAL; 1397 } 1398 1399 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it 1400 * to avoid per-map type checks tripping on unknown flag 1401 */ 1402 token_flag = attr->map_flags & BPF_F_TOKEN_FD; 1403 attr->map_flags &= ~BPF_F_TOKEN_FD; 1404 1405 if (attr->btf_vmlinux_value_type_id) { 1406 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 1407 bpf_log(log, "btf_vmlinux_value_type_id can only be used with struct_ops maps.\n"); 1408 return -EINVAL; 1409 } 1410 if (attr->btf_key_type_id || attr->btf_value_type_id) { 1411 bpf_log(log, "btf_vmlinux_value_type_id is mutually exclusive with btf_key_type_id and btf_value_type_id.\n"); 1412 return -EINVAL; 1413 } 1414 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1415 bpf_log(log, "Invalid btf_value_type_id.\n"); 1416 return -EINVAL; 1417 } 1418 1419 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1420 attr->map_type != BPF_MAP_TYPE_ARENA && 1421 attr->map_type != BPF_MAP_TYPE_RHASH && 1422 attr->map_extra != 0) { 1423 bpf_log(log, "Invalid map_extra.\n"); 1424 return -EINVAL; 1425 } 1426 1427 if (numa_node != NUMA_NO_NODE && 1428 ((unsigned int)numa_node >= nr_node_ids || 1429 !node_online(numa_node))) { 1430 bpf_log(log, "Invalid numa_node.\n"); 1431 return -EINVAL; 1432 } 1433 1434 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1435 map_type = attr->map_type; 1436 if (map_type >= ARRAY_SIZE(bpf_map_types)) { 1437 bpf_log(log, "Invalid map_type.\n"); 1438 return -EINVAL; 1439 } 1440 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1441 ops = bpf_map_types[map_type]; 1442 if (!ops) 1443 return -EINVAL; 1444 1445 if (ops->map_alloc_check) { 1446 err = ops->map_alloc_check(attr); 1447 if (err) 1448 return err; 1449 } 1450 if (attr->map_ifindex) 1451 ops = &bpf_map_offload_ops; 1452 if (!ops->map_mem_usage) 1453 return -EINVAL; 1454 1455 if (token_flag) { 1456 token = bpf_token_get_from_fd(attr->map_token_fd); 1457 if (IS_ERR(token)) { 1458 bpf_log(log, "Invalid map_token_fd.\n"); 1459 return PTR_ERR(token); 1460 } 1461 1462 /* if current token doesn't grant map creation permissions, 1463 * then we can't use this token, so ignore it and rely on 1464 * system-wide capabilities checks 1465 */ 1466 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || 1467 !bpf_token_allow_map_type(token, attr->map_type)) { 1468 bpf_token_put(token); 1469 token = NULL; 1470 } 1471 } 1472 1473 err = -EPERM; 1474 1475 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1476 * creation for unprivileged users; other actions depend 1477 * on fd availability and access to bpffs, so are dependent on 1478 * object creation success. Even with unprivileged BPF disabled, 1479 * capability checks are still carried out. 1480 */ 1481 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) 1482 goto put_token; 1483 1484 /* check privileged map type permissions */ 1485 switch (map_type) { 1486 case BPF_MAP_TYPE_ARRAY: 1487 case BPF_MAP_TYPE_PERCPU_ARRAY: 1488 case BPF_MAP_TYPE_PROG_ARRAY: 1489 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1490 case BPF_MAP_TYPE_CGROUP_ARRAY: 1491 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1492 case BPF_MAP_TYPE_HASH: 1493 case BPF_MAP_TYPE_RHASH: 1494 case BPF_MAP_TYPE_PERCPU_HASH: 1495 case BPF_MAP_TYPE_HASH_OF_MAPS: 1496 case BPF_MAP_TYPE_RINGBUF: 1497 case BPF_MAP_TYPE_USER_RINGBUF: 1498 case BPF_MAP_TYPE_CGROUP_STORAGE: 1499 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1500 /* unprivileged */ 1501 break; 1502 case BPF_MAP_TYPE_SK_STORAGE: 1503 case BPF_MAP_TYPE_INODE_STORAGE: 1504 case BPF_MAP_TYPE_TASK_STORAGE: 1505 case BPF_MAP_TYPE_CGRP_STORAGE: 1506 case BPF_MAP_TYPE_BLOOM_FILTER: 1507 case BPF_MAP_TYPE_LPM_TRIE: 1508 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1509 case BPF_MAP_TYPE_STACK_TRACE: 1510 case BPF_MAP_TYPE_QUEUE: 1511 case BPF_MAP_TYPE_STACK: 1512 case BPF_MAP_TYPE_LRU_HASH: 1513 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1514 case BPF_MAP_TYPE_STRUCT_OPS: 1515 case BPF_MAP_TYPE_CPUMAP: 1516 case BPF_MAP_TYPE_ARENA: 1517 case BPF_MAP_TYPE_INSN_ARRAY: 1518 if (!bpf_token_capable(token, CAP_BPF)) 1519 goto put_token; 1520 break; 1521 case BPF_MAP_TYPE_SOCKMAP: 1522 case BPF_MAP_TYPE_SOCKHASH: 1523 case BPF_MAP_TYPE_DEVMAP: 1524 case BPF_MAP_TYPE_DEVMAP_HASH: 1525 case BPF_MAP_TYPE_XSKMAP: 1526 if (!bpf_token_capable(token, CAP_NET_ADMIN)) 1527 goto put_token; 1528 break; 1529 default: 1530 WARN(1, "unsupported map type %d", map_type); 1531 goto put_token; 1532 } 1533 1534 map = ops->map_alloc(attr); 1535 if (IS_ERR(map)) { 1536 err = PTR_ERR(map); 1537 goto put_token; 1538 } 1539 map->ops = ops; 1540 map->map_type = map_type; 1541 1542 err = bpf_obj_name_cpy(map->name, attr->map_name, 1543 sizeof(attr->map_name)); 1544 if (err < 0) { 1545 bpf_log(log, "Invalid map_name.\n"); 1546 goto free_map; 1547 } 1548 1549 preempt_disable(); 1550 map->cookie = gen_cookie_next(&bpf_map_cookie); 1551 preempt_enable(); 1552 1553 atomic64_set(&map->refcnt, 1); 1554 atomic64_set(&map->usercnt, 1); 1555 mutex_init(&map->freeze_mutex); 1556 spin_lock_init(&map->owner_lock); 1557 1558 if (attr->btf_key_type_id || attr->btf_value_type_id || 1559 /* Even the map's value is a kernel's struct, 1560 * the bpf_prog.o must have BTF to begin with 1561 * to figure out the corresponding kernel's 1562 * counter part. Thus, attr->btf_fd has 1563 * to be valid also. 1564 */ 1565 attr->btf_vmlinux_value_type_id) { 1566 struct btf *btf; 1567 1568 btf = btf_get_by_fd(attr->btf_fd); 1569 if (IS_ERR(btf)) { 1570 bpf_log(log, "Invalid btf_fd.\n"); 1571 err = PTR_ERR(btf); 1572 goto free_map; 1573 } 1574 if (btf_is_kernel(btf)) { 1575 btf_put(btf); 1576 err = -EACCES; 1577 goto free_map; 1578 } 1579 map->btf = btf; 1580 1581 if (attr->btf_value_type_id) { 1582 err = map_check_btf(map, token, btf, attr->btf_key_type_id, 1583 attr->btf_value_type_id); 1584 if (err) 1585 goto free_map; 1586 } 1587 1588 map->btf_key_type_id = attr->btf_key_type_id; 1589 map->btf_value_type_id = attr->btf_value_type_id; 1590 map->btf_vmlinux_value_type_id = 1591 attr->btf_vmlinux_value_type_id; 1592 } 1593 1594 if (attr->excl_prog_hash) { 1595 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); 1596 1597 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { 1598 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1599 err = -EINVAL; 1600 goto free_map; 1601 } 1602 1603 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); 1604 if (!map->excl_prog_sha) { 1605 err = -ENOMEM; 1606 goto free_map; 1607 } 1608 1609 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) { 1610 err = -EFAULT; 1611 goto free_map; 1612 } 1613 } else if (attr->excl_prog_hash_size) { 1614 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1615 err = -EINVAL; 1616 goto free_map; 1617 } 1618 1619 *mapp = map; 1620 *tokenp = token; 1621 return 0; 1622 1623 free_map: 1624 bpf_map_free(map); 1625 put_token: 1626 bpf_token_put(token); 1627 return err; 1628 } 1629 1630 static int map_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common, 1631 bpfptr_t uattr_common, u32 size_common) 1632 { 1633 struct bpf_token *token = NULL; 1634 struct bpf_verifier_log *log; 1635 struct bpf_log_attr attr_log; 1636 struct bpf_map *map = NULL; 1637 int err, ret; 1638 int f_flags; 1639 1640 log = bpf_log_attr_create_vlog(&attr_log, attr_common, uattr_common, size_common); 1641 if (IS_ERR(log)) 1642 return PTR_ERR(log); 1643 1644 err = map_create_alloc(attr, uattr, log, &map, &token); 1645 1646 /* preserve original error even if log finalization is successful */ 1647 ret = bpf_log_attr_finalize(&attr_log, log); 1648 if (ret) 1649 err = ret; 1650 1651 kfree(log); 1652 1653 if (err) 1654 goto free_map; 1655 1656 f_flags = bpf_get_file_flag(attr->map_flags); 1657 if (f_flags < 0) { 1658 err = f_flags; 1659 goto free_map; 1660 } 1661 1662 err = security_bpf_map_create(map, attr, token, uattr.is_kernel); 1663 if (err) 1664 goto free_map; 1665 1666 err = bpf_map_alloc_id(map); 1667 if (err) 1668 goto free_map_sec; 1669 1670 bpf_map_save_memcg(map); 1671 bpf_token_put(token); 1672 1673 err = bpf_map_new_fd(map, f_flags); 1674 if (err < 0) { 1675 /* failed to allocate fd. 1676 * bpf_map_put_with_uref() is needed because the above 1677 * bpf_map_alloc_id() has published the map 1678 * to the userspace and the userspace may 1679 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1680 */ 1681 bpf_map_put_with_uref(map); 1682 return err; 1683 } 1684 1685 return err; 1686 1687 free_map_sec: 1688 security_bpf_map_free(map); 1689 free_map: 1690 if (map) 1691 bpf_map_free(map); 1692 bpf_token_put(token); 1693 return err; 1694 } 1695 1696 void bpf_map_inc(struct bpf_map *map) 1697 { 1698 atomic64_inc(&map->refcnt); 1699 } 1700 EXPORT_SYMBOL_GPL(bpf_map_inc); 1701 1702 void bpf_map_inc_with_uref(struct bpf_map *map) 1703 { 1704 atomic64_inc(&map->refcnt); 1705 atomic64_inc(&map->usercnt); 1706 } 1707 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1708 1709 struct bpf_map *bpf_map_get(u32 ufd) 1710 { 1711 CLASS(fd, f)(ufd); 1712 struct bpf_map *map = __bpf_map_get(f); 1713 1714 if (!IS_ERR(map)) 1715 bpf_map_inc(map); 1716 1717 return map; 1718 } 1719 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); 1720 1721 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1722 { 1723 CLASS(fd, f)(ufd); 1724 struct bpf_map *map = __bpf_map_get(f); 1725 1726 if (!IS_ERR(map)) 1727 bpf_map_inc_with_uref(map); 1728 1729 return map; 1730 } 1731 1732 /* map_idr_lock should have been held or the map should have been 1733 * protected by rcu read lock. 1734 */ 1735 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1736 { 1737 int refold; 1738 1739 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1740 if (!refold) 1741 return ERR_PTR(-ENOENT); 1742 if (uref) 1743 atomic64_inc(&map->usercnt); 1744 1745 return map; 1746 } 1747 1748 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1749 { 1750 lockdep_assert(rcu_read_lock_held()); 1751 return __bpf_map_inc_not_zero(map, false); 1752 } 1753 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1754 1755 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value, 1756 bool delete) 1757 { 1758 return -ENOTSUPP; 1759 } 1760 1761 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1762 { 1763 if (key_size) 1764 return vmemdup_user(ukey, key_size); 1765 1766 if (ukey) 1767 return ERR_PTR(-EINVAL); 1768 1769 return NULL; 1770 } 1771 1772 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1773 { 1774 if (key_size) 1775 return kvmemdup_bpfptr(ukey, key_size); 1776 1777 if (!bpfptr_is_null(ukey)) 1778 return ERR_PTR(-EINVAL); 1779 1780 return NULL; 1781 } 1782 1783 /* last field in 'union bpf_attr' used by this command */ 1784 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1785 1786 static int map_lookup_elem(union bpf_attr *attr) 1787 { 1788 void __user *ukey = u64_to_user_ptr(attr->key); 1789 void __user *uvalue = u64_to_user_ptr(attr->value); 1790 struct bpf_map *map; 1791 void *key, *value; 1792 u32 value_size; 1793 int err; 1794 1795 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1796 return -EINVAL; 1797 1798 CLASS(fd, f)(attr->map_fd); 1799 map = __bpf_map_get(f); 1800 if (IS_ERR(map)) 1801 return PTR_ERR(map); 1802 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1803 return -EPERM; 1804 1805 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU); 1806 if (err) 1807 return err; 1808 1809 key = __bpf_copy_key(ukey, map->key_size); 1810 if (IS_ERR(key)) 1811 return PTR_ERR(key); 1812 1813 value_size = bpf_map_value_size(map, attr->flags); 1814 1815 err = -ENOMEM; 1816 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1817 if (!value) 1818 goto free_key; 1819 1820 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1821 if (copy_from_user(value, uvalue, value_size)) 1822 err = -EFAULT; 1823 else 1824 err = bpf_map_copy_value(map, key, value, attr->flags); 1825 goto free_value; 1826 } 1827 1828 err = bpf_map_copy_value(map, key, value, attr->flags); 1829 if (err) 1830 goto free_value; 1831 1832 err = -EFAULT; 1833 if (copy_to_user(uvalue, value, value_size) != 0) 1834 goto free_value; 1835 1836 err = 0; 1837 1838 free_value: 1839 kvfree(value); 1840 free_key: 1841 kvfree(key); 1842 return err; 1843 } 1844 1845 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1846 1847 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1848 { 1849 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1850 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1851 struct bpf_map *map; 1852 void *key, *value; 1853 u32 value_size; 1854 int err; 1855 1856 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1857 return -EINVAL; 1858 1859 CLASS(fd, f)(attr->map_fd); 1860 map = __bpf_map_get(f); 1861 if (IS_ERR(map)) 1862 return PTR_ERR(map); 1863 bpf_map_write_active_inc(map); 1864 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1865 err = -EPERM; 1866 goto err_put; 1867 } 1868 1869 err = bpf_map_check_op_flags(map, attr->flags, ~0); 1870 if (err) 1871 goto err_put; 1872 1873 key = ___bpf_copy_key(ukey, map->key_size); 1874 if (IS_ERR(key)) { 1875 err = PTR_ERR(key); 1876 goto err_put; 1877 } 1878 1879 value_size = bpf_map_value_size(map, attr->flags); 1880 value = kvmemdup_bpfptr(uvalue, value_size); 1881 if (IS_ERR(value)) { 1882 err = PTR_ERR(value); 1883 goto free_key; 1884 } 1885 1886 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); 1887 if (!err) 1888 maybe_wait_bpf_programs(map); 1889 1890 kvfree(value); 1891 free_key: 1892 kvfree(key); 1893 err_put: 1894 bpf_map_write_active_dec(map); 1895 return err; 1896 } 1897 1898 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1899 1900 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1901 { 1902 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1903 struct bpf_map *map; 1904 void *key; 1905 int err; 1906 1907 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1908 return -EINVAL; 1909 1910 CLASS(fd, f)(attr->map_fd); 1911 map = __bpf_map_get(f); 1912 if (IS_ERR(map)) 1913 return PTR_ERR(map); 1914 bpf_map_write_active_inc(map); 1915 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1916 err = -EPERM; 1917 goto err_put; 1918 } 1919 1920 key = ___bpf_copy_key(ukey, map->key_size); 1921 if (IS_ERR(key)) { 1922 err = PTR_ERR(key); 1923 goto err_put; 1924 } 1925 1926 if (bpf_map_is_offloaded(map)) { 1927 err = bpf_map_offload_delete_elem(map, key); 1928 goto out; 1929 } else if (IS_FD_PROG_ARRAY(map) || 1930 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1931 /* These maps require sleepable context */ 1932 err = map->ops->map_delete_elem(map, key); 1933 goto out; 1934 } 1935 1936 bpf_disable_instrumentation(); 1937 rcu_read_lock(); 1938 err = map->ops->map_delete_elem(map, key); 1939 rcu_read_unlock(); 1940 bpf_enable_instrumentation(); 1941 if (!err) 1942 maybe_wait_bpf_programs(map); 1943 out: 1944 kvfree(key); 1945 err_put: 1946 bpf_map_write_active_dec(map); 1947 return err; 1948 } 1949 1950 /* last field in 'union bpf_attr' used by this command */ 1951 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1952 1953 static int map_get_next_key(union bpf_attr *attr) 1954 { 1955 void __user *ukey = u64_to_user_ptr(attr->key); 1956 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1957 struct bpf_map *map; 1958 void *key, *next_key; 1959 int err; 1960 1961 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1962 return -EINVAL; 1963 1964 CLASS(fd, f)(attr->map_fd); 1965 map = __bpf_map_get(f); 1966 if (IS_ERR(map)) 1967 return PTR_ERR(map); 1968 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1969 return -EPERM; 1970 1971 if (ukey) { 1972 key = __bpf_copy_key(ukey, map->key_size); 1973 if (IS_ERR(key)) 1974 return PTR_ERR(key); 1975 } else { 1976 key = NULL; 1977 } 1978 1979 err = -ENOMEM; 1980 next_key = kvmalloc(map->key_size, GFP_USER); 1981 if (!next_key) 1982 goto free_key; 1983 1984 if (bpf_map_is_offloaded(map)) { 1985 err = bpf_map_offload_get_next_key(map, key, next_key); 1986 goto out; 1987 } 1988 1989 rcu_read_lock(); 1990 err = map->ops->map_get_next_key(map, key, next_key); 1991 rcu_read_unlock(); 1992 out: 1993 if (err) 1994 goto free_next_key; 1995 1996 err = -EFAULT; 1997 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1998 goto free_next_key; 1999 2000 err = 0; 2001 2002 free_next_key: 2003 kvfree(next_key); 2004 free_key: 2005 kvfree(key); 2006 return err; 2007 } 2008 2009 int generic_map_delete_batch(struct bpf_map *map, 2010 const union bpf_attr *attr, 2011 union bpf_attr __user *uattr) 2012 { 2013 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2014 u32 cp, max_count; 2015 int err = 0; 2016 void *key; 2017 2018 if (attr->batch.elem_flags & ~BPF_F_LOCK) 2019 return -EINVAL; 2020 2021 if ((attr->batch.elem_flags & BPF_F_LOCK) && 2022 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2023 return -EINVAL; 2024 } 2025 2026 max_count = attr->batch.count; 2027 if (!max_count) 2028 return 0; 2029 2030 if (put_user(0, &uattr->batch.count)) 2031 return -EFAULT; 2032 2033 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2034 if (!key) 2035 return -ENOMEM; 2036 2037 for (cp = 0; cp < max_count; cp++) { 2038 err = -EFAULT; 2039 if (copy_from_user(key, keys + (size_t)cp * map->key_size, 2040 map->key_size)) 2041 break; 2042 2043 if (bpf_map_is_offloaded(map)) { 2044 err = bpf_map_offload_delete_elem(map, key); 2045 break; 2046 } 2047 2048 bpf_disable_instrumentation(); 2049 rcu_read_lock(); 2050 err = map->ops->map_delete_elem(map, key); 2051 rcu_read_unlock(); 2052 bpf_enable_instrumentation(); 2053 if (err) 2054 break; 2055 cond_resched(); 2056 } 2057 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2058 err = -EFAULT; 2059 2060 kvfree(key); 2061 2062 return err; 2063 } 2064 2065 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 2066 const union bpf_attr *attr, 2067 union bpf_attr __user *uattr) 2068 { 2069 void __user *values = u64_to_user_ptr(attr->batch.values); 2070 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2071 u32 value_size, cp, max_count; 2072 void *key, *value; 2073 int err = 0; 2074 2075 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, 2076 BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS); 2077 if (err) 2078 return err; 2079 2080 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2081 2082 max_count = attr->batch.count; 2083 if (!max_count) 2084 return 0; 2085 2086 if (put_user(0, &uattr->batch.count)) 2087 return -EFAULT; 2088 2089 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2090 if (!key) 2091 return -ENOMEM; 2092 2093 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2094 if (!value) { 2095 kvfree(key); 2096 return -ENOMEM; 2097 } 2098 2099 for (cp = 0; cp < max_count; cp++) { 2100 err = -EFAULT; 2101 if (copy_from_user(key, keys + (size_t)cp * map->key_size, 2102 map->key_size) || 2103 copy_from_user(value, values + (size_t)cp * value_size, value_size)) 2104 break; 2105 2106 err = bpf_map_update_value(map, map_file, key, value, 2107 attr->batch.elem_flags); 2108 2109 if (err) 2110 break; 2111 cond_resched(); 2112 } 2113 2114 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2115 err = -EFAULT; 2116 2117 kvfree(value); 2118 kvfree(key); 2119 2120 return err; 2121 } 2122 2123 int generic_map_lookup_batch(struct bpf_map *map, 2124 const union bpf_attr *attr, 2125 union bpf_attr __user *uattr) 2126 { 2127 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 2128 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 2129 void __user *values = u64_to_user_ptr(attr->batch.values); 2130 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2131 void *buf, *buf_prevkey, *prev_key, *key, *value; 2132 u32 value_size, cp, max_count; 2133 int err; 2134 2135 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU); 2136 if (err) 2137 return err; 2138 2139 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2140 2141 max_count = attr->batch.count; 2142 if (!max_count) 2143 return 0; 2144 2145 if (put_user(0, &uattr->batch.count)) 2146 return -EFAULT; 2147 2148 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2149 if (!buf_prevkey) 2150 return -ENOMEM; 2151 2152 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 2153 if (!buf) { 2154 kvfree(buf_prevkey); 2155 return -ENOMEM; 2156 } 2157 2158 err = -EFAULT; 2159 prev_key = NULL; 2160 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 2161 goto free_buf; 2162 key = buf; 2163 value = key + map->key_size; 2164 if (ubatch) 2165 prev_key = buf_prevkey; 2166 2167 for (cp = 0; cp < max_count;) { 2168 rcu_read_lock(); 2169 err = map->ops->map_get_next_key(map, prev_key, key); 2170 rcu_read_unlock(); 2171 if (err) 2172 break; 2173 err = bpf_map_copy_value(map, key, value, 2174 attr->batch.elem_flags); 2175 2176 if (err == -ENOENT) 2177 goto next_key; 2178 2179 if (err) 2180 goto free_buf; 2181 2182 if (copy_to_user(keys + (size_t)cp * map->key_size, key, 2183 map->key_size)) { 2184 err = -EFAULT; 2185 goto free_buf; 2186 } 2187 if (copy_to_user(values + (size_t)cp * value_size, value, value_size)) { 2188 err = -EFAULT; 2189 goto free_buf; 2190 } 2191 2192 cp++; 2193 next_key: 2194 if (!prev_key) 2195 prev_key = buf_prevkey; 2196 2197 swap(prev_key, key); 2198 cond_resched(); 2199 } 2200 2201 if (err == -EFAULT) 2202 goto free_buf; 2203 2204 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 2205 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 2206 err = -EFAULT; 2207 2208 free_buf: 2209 kvfree(buf_prevkey); 2210 kvfree(buf); 2211 return err; 2212 } 2213 2214 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 2215 2216 static int map_lookup_and_delete_elem(union bpf_attr *attr) 2217 { 2218 void __user *ukey = u64_to_user_ptr(attr->key); 2219 void __user *uvalue = u64_to_user_ptr(attr->value); 2220 struct bpf_map *map; 2221 void *key, *value; 2222 u32 value_size; 2223 int err; 2224 2225 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 2226 return -EINVAL; 2227 2228 if (attr->flags & ~BPF_F_LOCK) 2229 return -EINVAL; 2230 2231 CLASS(fd, f)(attr->map_fd); 2232 map = __bpf_map_get(f); 2233 if (IS_ERR(map)) 2234 return PTR_ERR(map); 2235 bpf_map_write_active_inc(map); 2236 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 2237 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2238 err = -EPERM; 2239 goto err_put; 2240 } 2241 2242 if (attr->flags && 2243 (map->map_type == BPF_MAP_TYPE_QUEUE || 2244 map->map_type == BPF_MAP_TYPE_STACK)) { 2245 err = -EINVAL; 2246 goto err_put; 2247 } 2248 2249 if ((attr->flags & BPF_F_LOCK) && 2250 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2251 err = -EINVAL; 2252 goto err_put; 2253 } 2254 2255 key = __bpf_copy_key(ukey, map->key_size); 2256 if (IS_ERR(key)) { 2257 err = PTR_ERR(key); 2258 goto err_put; 2259 } 2260 2261 value_size = bpf_map_value_size(map, 0); 2262 2263 err = -ENOMEM; 2264 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2265 if (!value) 2266 goto free_key; 2267 2268 err = -ENOTSUPP; 2269 if (map->map_type == BPF_MAP_TYPE_QUEUE || 2270 map->map_type == BPF_MAP_TYPE_STACK) { 2271 err = map->ops->map_pop_elem(map, value); 2272 } else if (map->map_type == BPF_MAP_TYPE_HASH || 2273 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 2274 map->map_type == BPF_MAP_TYPE_LRU_HASH || 2275 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 2276 map->map_type == BPF_MAP_TYPE_RHASH || 2277 map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 2278 if (!bpf_map_is_offloaded(map)) { 2279 bpf_disable_instrumentation(); 2280 rcu_read_lock(); 2281 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 2282 rcu_read_unlock(); 2283 bpf_enable_instrumentation(); 2284 } 2285 } 2286 2287 if (err) 2288 goto free_value; 2289 2290 if (copy_to_user(uvalue, value, value_size) != 0) { 2291 err = -EFAULT; 2292 goto free_value; 2293 } 2294 2295 err = 0; 2296 2297 free_value: 2298 kvfree(value); 2299 free_key: 2300 kvfree(key); 2301 err_put: 2302 bpf_map_write_active_dec(map); 2303 return err; 2304 } 2305 2306 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2307 2308 static int map_freeze(const union bpf_attr *attr) 2309 { 2310 int err = 0; 2311 struct bpf_map *map; 2312 2313 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2314 return -EINVAL; 2315 2316 CLASS(fd, f)(attr->map_fd); 2317 map = __bpf_map_get(f); 2318 if (IS_ERR(map)) 2319 return PTR_ERR(map); 2320 2321 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) 2322 return -ENOTSUPP; 2323 2324 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) 2325 return -EPERM; 2326 2327 mutex_lock(&map->freeze_mutex); 2328 if (bpf_map_write_active(map)) { 2329 err = -EBUSY; 2330 goto err_put; 2331 } 2332 if (READ_ONCE(map->frozen)) { 2333 err = -EBUSY; 2334 goto err_put; 2335 } 2336 2337 WRITE_ONCE(map->frozen, true); 2338 err_put: 2339 mutex_unlock(&map->freeze_mutex); 2340 return err; 2341 } 2342 2343 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2344 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2345 [_id] = & _name ## _prog_ops, 2346 #define BPF_MAP_TYPE(_id, _ops) 2347 #define BPF_LINK_TYPE(_id, _name) 2348 #include <linux/bpf_types.h> 2349 #undef BPF_PROG_TYPE 2350 #undef BPF_MAP_TYPE 2351 #undef BPF_LINK_TYPE 2352 }; 2353 2354 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2355 { 2356 const struct bpf_prog_ops *ops; 2357 2358 if (type >= ARRAY_SIZE(bpf_prog_types)) 2359 return -EINVAL; 2360 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2361 ops = bpf_prog_types[type]; 2362 if (!ops) 2363 return -EINVAL; 2364 2365 if (!bpf_prog_is_offloaded(prog->aux)) 2366 prog->aux->ops = ops; 2367 else 2368 prog->aux->ops = &bpf_offload_prog_ops; 2369 prog->type = type; 2370 return 0; 2371 } 2372 2373 enum bpf_audit { 2374 BPF_AUDIT_LOAD, 2375 BPF_AUDIT_UNLOAD, 2376 BPF_AUDIT_MAX, 2377 }; 2378 2379 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2380 [BPF_AUDIT_LOAD] = "LOAD", 2381 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2382 }; 2383 2384 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2385 { 2386 struct audit_context *ctx = NULL; 2387 struct audit_buffer *ab; 2388 2389 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2390 return; 2391 if (audit_enabled == AUDIT_OFF) 2392 return; 2393 if (!in_hardirq() && !irqs_disabled()) 2394 ctx = audit_context(); 2395 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2396 if (unlikely(!ab)) 2397 return; 2398 audit_log_format(ab, "prog-id=%u op=%s", 2399 prog->aux->id, bpf_audit_str[op]); 2400 audit_log_end(ab); 2401 } 2402 2403 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2404 { 2405 int id; 2406 2407 idr_preload(GFP_KERNEL); 2408 spin_lock_bh(&prog_idr_lock); 2409 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2410 if (id > 0) 2411 prog->aux->id = id; 2412 spin_unlock_bh(&prog_idr_lock); 2413 idr_preload_end(); 2414 2415 /* id is in [1, INT_MAX) */ 2416 if (WARN_ON_ONCE(!id)) 2417 return -ENOSPC; 2418 2419 return id > 0 ? 0 : id; 2420 } 2421 2422 void bpf_prog_free_id(struct bpf_prog *prog) 2423 { 2424 unsigned long flags; 2425 2426 /* cBPF to eBPF migrations are currently not in the idr store. 2427 * Offloaded programs are removed from the store when their device 2428 * disappears - even if someone grabs an fd to them they are unusable, 2429 * simply waiting for refcnt to drop to be freed. 2430 */ 2431 if (!prog->aux->id) 2432 return; 2433 2434 spin_lock_irqsave(&prog_idr_lock, flags); 2435 idr_remove(&prog_idr, prog->aux->id); 2436 prog->aux->id = 0; 2437 spin_unlock_irqrestore(&prog_idr_lock, flags); 2438 } 2439 2440 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2441 { 2442 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2443 2444 kvfree(aux->func_info); 2445 kfree(aux->func_info_aux); 2446 free_uid(aux->user); 2447 security_bpf_prog_free(aux->prog); 2448 bpf_prog_free(aux->prog); 2449 } 2450 2451 /* 2452 * Progs called from a trampoline can also be reached by a task that was 2453 * preempted in the trampoline before the prog's enter helper took its RCU 2454 * read lock, wait for those first. 2455 */ 2456 static void __bpf_prog_put_rcu_tasks(struct rcu_head *rcu) 2457 { 2458 struct bpf_prog *prog = container_of(rcu, struct bpf_prog_aux, rcu)->prog; 2459 2460 if (prog->sleepable) 2461 call_rcu_tasks_trace(rcu, __bpf_prog_put_rcu); 2462 else 2463 call_rcu(rcu, __bpf_prog_put_rcu); 2464 } 2465 2466 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2467 { 2468 bpf_prog_kallsyms_del_all(prog); 2469 btf_put(prog->aux->btf); 2470 module_put(prog->aux->mod); 2471 kvfree(prog->aux->jited_linfo); 2472 kvfree(prog->aux->linfo); 2473 kfree(prog->aux->kfunc_tab); 2474 kfree(prog->aux->ctx_arg_info); 2475 if (prog->aux->attach_btf) 2476 btf_put(prog->aux->attach_btf); 2477 2478 if (deferred) { 2479 if (IS_ENABLED(CONFIG_TASKS_RCU) && prog->aux->tramp_linked) 2480 call_rcu_tasks(&prog->aux->rcu, __bpf_prog_put_rcu_tasks); 2481 else if (prog->sleepable) 2482 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2483 else 2484 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2485 } else { 2486 __bpf_prog_put_rcu(&prog->aux->rcu); 2487 } 2488 } 2489 2490 static void bpf_prog_put_deferred(struct work_struct *work) 2491 { 2492 struct bpf_prog_aux *aux; 2493 struct bpf_prog *prog; 2494 2495 aux = container_of(work, struct bpf_prog_aux, work); 2496 prog = aux->prog; 2497 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2498 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2499 bpf_prog_free_id(prog); 2500 __bpf_prog_put_noref(prog, true); 2501 } 2502 2503 static void __bpf_prog_put(struct bpf_prog *prog) 2504 { 2505 struct bpf_prog_aux *aux = prog->aux; 2506 2507 if (atomic64_dec_and_test(&aux->refcnt)) { 2508 if (in_hardirq() || irqs_disabled()) { 2509 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2510 schedule_work(&aux->work); 2511 } else { 2512 bpf_prog_put_deferred(&aux->work); 2513 } 2514 } 2515 } 2516 2517 void bpf_prog_put(struct bpf_prog *prog) 2518 { 2519 __bpf_prog_put(prog); 2520 } 2521 EXPORT_SYMBOL_GPL(bpf_prog_put); 2522 2523 static int bpf_prog_release(struct inode *inode, struct file *filp) 2524 { 2525 struct bpf_prog *prog = filp->private_data; 2526 2527 bpf_prog_put(prog); 2528 return 0; 2529 } 2530 2531 struct bpf_prog_kstats { 2532 u64 nsecs; 2533 u64 cnt; 2534 u64 misses; 2535 }; 2536 2537 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2538 { 2539 struct bpf_prog_stats *stats; 2540 unsigned int flags; 2541 2542 if (unlikely(!prog->stats)) 2543 return; 2544 2545 stats = this_cpu_ptr(prog->stats); 2546 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2547 u64_stats_inc(&stats->misses); 2548 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2549 } 2550 2551 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2552 struct bpf_prog_kstats *stats) 2553 { 2554 u64 nsecs = 0, cnt = 0, misses = 0; 2555 int cpu; 2556 2557 for_each_possible_cpu(cpu) { 2558 const struct bpf_prog_stats *st; 2559 unsigned int start; 2560 u64 tnsecs, tcnt, tmisses; 2561 2562 st = per_cpu_ptr(prog->stats, cpu); 2563 do { 2564 start = u64_stats_fetch_begin(&st->syncp); 2565 tnsecs = u64_stats_read(&st->nsecs); 2566 tcnt = u64_stats_read(&st->cnt); 2567 tmisses = u64_stats_read(&st->misses); 2568 } while (u64_stats_fetch_retry(&st->syncp, start)); 2569 nsecs += tnsecs; 2570 cnt += tcnt; 2571 misses += tmisses; 2572 } 2573 stats->nsecs = nsecs; 2574 stats->cnt = cnt; 2575 stats->misses = misses; 2576 } 2577 2578 #ifdef CONFIG_PROC_FS 2579 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2580 { 2581 const struct bpf_prog *prog = filp->private_data; 2582 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2583 struct bpf_prog_kstats stats; 2584 2585 bpf_prog_get_stats(prog, &stats); 2586 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2587 seq_printf(m, 2588 "prog_type:\t%u\n" 2589 "prog_jited:\t%u\n" 2590 "prog_tag:\t%s\n" 2591 "memlock:\t%llu\n" 2592 "prog_id:\t%u\n" 2593 "run_time_ns:\t%llu\n" 2594 "run_cnt:\t%llu\n" 2595 "recursion_misses:\t%llu\n" 2596 "verified_insns:\t%u\n", 2597 prog->type, 2598 prog->jited, 2599 prog_tag, 2600 prog->pages * 1ULL << PAGE_SHIFT, 2601 prog->aux->id, 2602 stats.nsecs, 2603 stats.cnt, 2604 stats.misses, 2605 prog->aux->verified_insns); 2606 } 2607 #endif 2608 2609 const struct file_operations bpf_prog_fops = { 2610 #ifdef CONFIG_PROC_FS 2611 .show_fdinfo = bpf_prog_show_fdinfo, 2612 #endif 2613 .release = bpf_prog_release, 2614 .read = bpf_dummy_read, 2615 .write = bpf_dummy_write, 2616 }; 2617 2618 int bpf_prog_new_fd(struct bpf_prog *prog) 2619 { 2620 int ret; 2621 2622 ret = security_bpf_prog(prog); 2623 if (ret < 0) 2624 return ret; 2625 2626 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2627 O_RDWR | O_CLOEXEC); 2628 } 2629 2630 void bpf_prog_add(struct bpf_prog *prog, int i) 2631 { 2632 atomic64_add(i, &prog->aux->refcnt); 2633 } 2634 EXPORT_SYMBOL_GPL(bpf_prog_add); 2635 2636 void bpf_prog_sub(struct bpf_prog *prog, int i) 2637 { 2638 /* Only to be used for undoing previous bpf_prog_add() in some 2639 * error path. We still know that another entity in our call 2640 * path holds a reference to the program, thus atomic_sub() can 2641 * be safely used in such cases! 2642 */ 2643 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2644 } 2645 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2646 2647 void bpf_prog_inc(struct bpf_prog *prog) 2648 { 2649 atomic64_inc(&prog->aux->refcnt); 2650 } 2651 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2652 2653 /* prog_idr_lock should have been held */ 2654 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2655 { 2656 int refold; 2657 2658 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2659 2660 if (!refold) 2661 return ERR_PTR(-ENOENT); 2662 2663 return prog; 2664 } 2665 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2666 2667 bool bpf_prog_get_ok(struct bpf_prog *prog, 2668 enum bpf_prog_type *attach_type, bool attach_drv) 2669 { 2670 /* not an attachment, just a refcount inc, always allow */ 2671 if (!attach_type) 2672 return true; 2673 2674 if (prog->type != *attach_type) 2675 return false; 2676 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2677 return false; 2678 2679 return true; 2680 } 2681 2682 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2683 bool attach_drv) 2684 { 2685 CLASS(fd, f)(ufd); 2686 struct bpf_prog *prog; 2687 2688 if (fd_empty(f)) 2689 return ERR_PTR(-EBADF); 2690 if (fd_file(f)->f_op != &bpf_prog_fops) 2691 return ERR_PTR(-EINVAL); 2692 2693 prog = fd_file(f)->private_data; 2694 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2695 return ERR_PTR(-EINVAL); 2696 2697 bpf_prog_inc(prog); 2698 return prog; 2699 } 2700 2701 struct bpf_prog *bpf_prog_get(u32 ufd) 2702 { 2703 return __bpf_prog_get(ufd, NULL, false); 2704 } 2705 2706 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2707 bool attach_drv) 2708 { 2709 return __bpf_prog_get(ufd, &type, attach_drv); 2710 } 2711 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2712 2713 /* Initially all BPF programs could be loaded w/o specifying 2714 * expected_attach_type. Later for some of them specifying expected_attach_type 2715 * at load time became required so that program could be validated properly. 2716 * Programs of types that are allowed to be loaded both w/ and w/o (for 2717 * backward compatibility) expected_attach_type, should have the default attach 2718 * type assigned to expected_attach_type for the latter case, so that it can be 2719 * validated later at attach time. 2720 * 2721 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2722 * prog type requires it but has some attach types that have to be backward 2723 * compatible. 2724 */ 2725 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2726 { 2727 switch (attr->prog_type) { 2728 case BPF_PROG_TYPE_CGROUP_SOCK: 2729 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2730 * exist so checking for non-zero is the way to go here. 2731 */ 2732 if (!attr->expected_attach_type) 2733 attr->expected_attach_type = 2734 BPF_CGROUP_INET_SOCK_CREATE; 2735 break; 2736 case BPF_PROG_TYPE_SK_REUSEPORT: 2737 if (!attr->expected_attach_type) 2738 attr->expected_attach_type = 2739 BPF_SK_REUSEPORT_SELECT; 2740 break; 2741 } 2742 } 2743 2744 static int 2745 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2746 enum bpf_attach_type expected_attach_type, 2747 struct btf *attach_btf, u32 btf_id, 2748 struct bpf_prog *dst_prog, 2749 bool multi_func) 2750 { 2751 if (btf_id) { 2752 if (btf_id > BTF_MAX_TYPE) 2753 return -EINVAL; 2754 2755 if (!attach_btf && !dst_prog) 2756 return -EINVAL; 2757 2758 switch (prog_type) { 2759 case BPF_PROG_TYPE_TRACING: 2760 case BPF_PROG_TYPE_LSM: 2761 case BPF_PROG_TYPE_STRUCT_OPS: 2762 case BPF_PROG_TYPE_EXT: 2763 break; 2764 default: 2765 return -EINVAL; 2766 } 2767 } 2768 2769 if (multi_func) { 2770 if (prog_type != BPF_PROG_TYPE_TRACING) 2771 return -EINVAL; 2772 if (!attach_btf || btf_id) 2773 return -EINVAL; 2774 return 0; 2775 } 2776 2777 if (attach_btf && (!btf_id || dst_prog)) 2778 return -EINVAL; 2779 2780 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2781 prog_type != BPF_PROG_TYPE_EXT) 2782 return -EINVAL; 2783 2784 switch (prog_type) { 2785 case BPF_PROG_TYPE_CGROUP_SOCK: 2786 switch (expected_attach_type) { 2787 case BPF_CGROUP_INET_SOCK_CREATE: 2788 case BPF_CGROUP_INET_SOCK_RELEASE: 2789 case BPF_CGROUP_INET4_POST_BIND: 2790 case BPF_CGROUP_INET6_POST_BIND: 2791 return 0; 2792 default: 2793 return -EINVAL; 2794 } 2795 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2796 switch (expected_attach_type) { 2797 case BPF_CGROUP_INET4_BIND: 2798 case BPF_CGROUP_INET6_BIND: 2799 case BPF_CGROUP_INET4_CONNECT: 2800 case BPF_CGROUP_INET6_CONNECT: 2801 case BPF_CGROUP_UNIX_CONNECT: 2802 case BPF_CGROUP_INET4_GETPEERNAME: 2803 case BPF_CGROUP_INET6_GETPEERNAME: 2804 case BPF_CGROUP_UNIX_GETPEERNAME: 2805 case BPF_CGROUP_INET4_GETSOCKNAME: 2806 case BPF_CGROUP_INET6_GETSOCKNAME: 2807 case BPF_CGROUP_UNIX_GETSOCKNAME: 2808 case BPF_CGROUP_UDP4_SENDMSG: 2809 case BPF_CGROUP_UDP6_SENDMSG: 2810 case BPF_CGROUP_UNIX_SENDMSG: 2811 case BPF_CGROUP_UDP4_RECVMSG: 2812 case BPF_CGROUP_UDP6_RECVMSG: 2813 case BPF_CGROUP_UNIX_RECVMSG: 2814 return 0; 2815 default: 2816 return -EINVAL; 2817 } 2818 case BPF_PROG_TYPE_CGROUP_SKB: 2819 switch (expected_attach_type) { 2820 case BPF_CGROUP_INET_INGRESS: 2821 case BPF_CGROUP_INET_EGRESS: 2822 return 0; 2823 default: 2824 return -EINVAL; 2825 } 2826 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2827 switch (expected_attach_type) { 2828 case BPF_CGROUP_SETSOCKOPT: 2829 case BPF_CGROUP_GETSOCKOPT: 2830 return 0; 2831 default: 2832 return -EINVAL; 2833 } 2834 case BPF_PROG_TYPE_SK_LOOKUP: 2835 if (expected_attach_type == BPF_SK_LOOKUP) 2836 return 0; 2837 return -EINVAL; 2838 case BPF_PROG_TYPE_SK_REUSEPORT: 2839 switch (expected_attach_type) { 2840 case BPF_SK_REUSEPORT_SELECT: 2841 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2842 return 0; 2843 default: 2844 return -EINVAL; 2845 } 2846 case BPF_PROG_TYPE_NETFILTER: 2847 if (expected_attach_type == BPF_NETFILTER) 2848 return 0; 2849 return -EINVAL; 2850 case BPF_PROG_TYPE_SYSCALL: 2851 case BPF_PROG_TYPE_EXT: 2852 if (expected_attach_type) 2853 return -EINVAL; 2854 fallthrough; 2855 default: 2856 return 0; 2857 } 2858 } 2859 2860 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2861 { 2862 switch (prog_type) { 2863 case BPF_PROG_TYPE_SCHED_CLS: 2864 case BPF_PROG_TYPE_SCHED_ACT: 2865 case BPF_PROG_TYPE_XDP: 2866 case BPF_PROG_TYPE_LWT_IN: 2867 case BPF_PROG_TYPE_LWT_OUT: 2868 case BPF_PROG_TYPE_LWT_XMIT: 2869 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2870 case BPF_PROG_TYPE_SK_SKB: 2871 case BPF_PROG_TYPE_SK_MSG: 2872 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2873 case BPF_PROG_TYPE_CGROUP_DEVICE: 2874 case BPF_PROG_TYPE_CGROUP_SOCK: 2875 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2876 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2877 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2878 case BPF_PROG_TYPE_SOCK_OPS: 2879 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2880 case BPF_PROG_TYPE_NETFILTER: 2881 return true; 2882 case BPF_PROG_TYPE_CGROUP_SKB: 2883 /* always unpriv */ 2884 case BPF_PROG_TYPE_SK_REUSEPORT: 2885 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2886 default: 2887 return false; 2888 } 2889 } 2890 2891 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2892 { 2893 switch (prog_type) { 2894 case BPF_PROG_TYPE_KPROBE: 2895 case BPF_PROG_TYPE_TRACEPOINT: 2896 case BPF_PROG_TYPE_PERF_EVENT: 2897 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2898 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2899 case BPF_PROG_TYPE_TRACING: 2900 case BPF_PROG_TYPE_LSM: 2901 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2902 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2903 return true; 2904 default: 2905 return false; 2906 } 2907 } 2908 2909 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) 2910 { 2911 int err; 2912 int i; 2913 2914 for (i = 0; i < prog->aux->used_map_cnt; i++) { 2915 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY) 2916 continue; 2917 2918 err = bpf_insn_array_ready(prog->aux->used_maps[i]); 2919 if (err) 2920 return err; 2921 } 2922 2923 return 0; 2924 } 2925 2926 extern int bpf_multi_func(void); 2927 int __init __used bpf_multi_func(void) { return 0; } 2928 2929 BTF_ID_LIST_GLOBAL_SINGLE(bpf_multi_func_btf_id, func, bpf_multi_func) 2930 2931 /* last field in 'union bpf_attr' used by this command */ 2932 #define BPF_PROG_LOAD_LAST_FIELD keyring_id 2933 2934 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 2935 { 2936 enum bpf_prog_type type = attr->prog_type; 2937 struct bpf_prog *prog, *dst_prog = NULL; 2938 struct btf *attach_btf = NULL; 2939 struct bpf_token *token = NULL; 2940 bool bpf_cap; 2941 int err; 2942 char license[128]; 2943 bool multi_func; 2944 2945 if (CHECK_ATTR(BPF_PROG_LOAD)) 2946 return -EINVAL; 2947 2948 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2949 BPF_F_ANY_ALIGNMENT | 2950 BPF_F_TEST_STATE_FREQ | 2951 BPF_F_SLEEPABLE | 2952 BPF_F_TEST_RND_HI32 | 2953 BPF_F_XDP_HAS_FRAGS | 2954 BPF_F_XDP_DEV_BOUND_ONLY | 2955 BPF_F_TEST_REG_INVARIANTS | 2956 BPF_F_TOKEN_FD)) 2957 return -EINVAL; 2958 2959 bpf_prog_load_fixup_attach_type(attr); 2960 2961 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2962 token = bpf_token_get_from_fd(attr->prog_token_fd); 2963 if (IS_ERR(token)) 2964 return PTR_ERR(token); 2965 /* if current token doesn't grant prog loading permissions, 2966 * then we can't use this token, so ignore it and rely on 2967 * system-wide capabilities checks 2968 */ 2969 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2970 !bpf_token_allow_prog_type(token, attr->prog_type, 2971 attr->expected_attach_type)) { 2972 bpf_token_put(token); 2973 token = NULL; 2974 } 2975 } 2976 2977 bpf_cap = bpf_token_capable(token, CAP_BPF); 2978 err = -EPERM; 2979 2980 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2981 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2982 !bpf_cap) 2983 goto put_token; 2984 2985 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2986 * creation for unprivileged users; other actions depend 2987 * on fd availability and access to bpffs, so are dependent on 2988 * object creation success. Even with unprivileged BPF disabled, 2989 * capability checks are still carried out for these 2990 * and other operations. 2991 */ 2992 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 2993 goto put_token; 2994 2995 if (attr->insn_cnt == 0 || 2996 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 2997 err = -E2BIG; 2998 goto put_token; 2999 } 3000 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 3001 type != BPF_PROG_TYPE_CGROUP_SKB && 3002 !bpf_cap) 3003 goto put_token; 3004 3005 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 3006 goto put_token; 3007 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 3008 goto put_token; 3009 3010 multi_func = is_tracing_multi(attr->expected_attach_type); 3011 3012 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 3013 * or btf, we need to check which one it is 3014 */ 3015 if (attr->attach_prog_fd) { 3016 dst_prog = bpf_prog_get(attr->attach_prog_fd); 3017 if (IS_ERR(dst_prog)) { 3018 dst_prog = NULL; 3019 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 3020 if (IS_ERR(attach_btf)) { 3021 err = -EINVAL; 3022 goto put_token; 3023 } 3024 if (!btf_is_kernel(attach_btf)) { 3025 /* attaching through specifying bpf_prog's BTF 3026 * objects directly might be supported eventually 3027 */ 3028 btf_put(attach_btf); 3029 err = -ENOTSUPP; 3030 goto put_token; 3031 } 3032 } 3033 } else if (attr->attach_btf_id || multi_func) { 3034 /* fall back to vmlinux BTF, if BTF type ID is specified */ 3035 attach_btf = bpf_get_btf_vmlinux(); 3036 if (IS_ERR(attach_btf)) { 3037 err = PTR_ERR(attach_btf); 3038 goto put_token; 3039 } 3040 if (!attach_btf) { 3041 err = -EINVAL; 3042 goto put_token; 3043 } 3044 btf_get(attach_btf); 3045 } 3046 3047 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 3048 attach_btf, attr->attach_btf_id, 3049 dst_prog, multi_func)) { 3050 if (dst_prog) 3051 bpf_prog_put(dst_prog); 3052 if (attach_btf) 3053 btf_put(attach_btf); 3054 err = -EINVAL; 3055 goto put_token; 3056 } 3057 3058 /* plain bpf_prog allocation */ 3059 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 3060 if (!prog) { 3061 if (dst_prog) 3062 bpf_prog_put(dst_prog); 3063 if (attach_btf) 3064 btf_put(attach_btf); 3065 err = -EINVAL; 3066 goto put_token; 3067 } 3068 3069 prog->expected_attach_type = attr->expected_attach_type; 3070 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 3071 prog->aux->attach_btf = attach_btf; 3072 prog->aux->attach_btf_id = multi_func ? bpf_multi_func_btf_id[0] : attr->attach_btf_id; 3073 prog->aux->dst_prog = dst_prog; 3074 if (dst_prog) { 3075 prog->aux->saved_dst_prog_type = dst_prog->type; 3076 prog->aux->saved_dst_attach_type = dst_prog->expected_attach_type; 3077 } 3078 prog->aux->dev_bound = !!attr->prog_ifindex; 3079 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 3080 3081 /* move token into prog->aux, reuse taken refcnt */ 3082 prog->aux->token = token; 3083 token = NULL; 3084 3085 prog->aux->user = get_current_user(); 3086 prog->len = attr->insn_cnt; 3087 3088 err = -EFAULT; 3089 if (copy_from_bpfptr(prog->insns, 3090 make_bpfptr(attr->insns, uattr.is_kernel), 3091 bpf_prog_insn_size(prog)) != 0) 3092 goto free_prog; 3093 /* copy eBPF program license from user space */ 3094 if (strncpy_from_bpfptr(license, 3095 make_bpfptr(attr->license, uattr.is_kernel), 3096 sizeof(license) - 1) < 0) 3097 goto free_prog; 3098 license[sizeof(license) - 1] = 0; 3099 3100 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 3101 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 3102 prog->aux->sig.keyring_type = BPF_SIG_KEYRING_NONE; 3103 prog->aux->sig.verdict = BPF_SIG_UNSIGNED; 3104 prog->orig_prog = NULL; 3105 prog->jited = 0; 3106 3107 atomic64_set(&prog->aux->refcnt, 1); 3108 3109 if (bpf_prog_is_dev_bound(prog->aux)) { 3110 err = bpf_prog_dev_bound_init(prog, attr); 3111 if (err) 3112 goto free_prog; 3113 } 3114 3115 if (type == BPF_PROG_TYPE_EXT && dst_prog && 3116 bpf_prog_is_dev_bound(dst_prog->aux)) { 3117 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 3118 if (err) 3119 goto free_prog; 3120 } 3121 3122 /* 3123 * Bookkeeping for managing the program attachment chain. 3124 * 3125 * It might be tempting to set attach_tracing_prog flag at the attachment 3126 * time, but this will not prevent from loading bunch of tracing prog 3127 * first, then attach them one to another. 3128 * 3129 * The flag attach_tracing_prog is set for the whole program lifecycle, and 3130 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 3131 * programs cannot change attachment target. 3132 */ 3133 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 3134 dst_prog->type == BPF_PROG_TYPE_TRACING) { 3135 prog->aux->attach_tracing_prog = true; 3136 } 3137 3138 /* find program type: socket_filter vs tracing_filter */ 3139 err = find_prog_type(type, prog); 3140 if (err < 0) 3141 goto free_prog; 3142 3143 prog->aux->load_time = ktime_get_boottime_ns(); 3144 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 3145 sizeof(attr->prog_name)); 3146 if (err < 0) 3147 goto free_prog; 3148 3149 /* run eBPF verifier */ 3150 err = bpf_check(&prog, attr, uattr, attr_log); 3151 if (err < 0) 3152 goto free_used_maps; 3153 3154 err = bpf_prog_mark_insn_arrays_ready(prog); 3155 if (err < 0) 3156 goto free_used_maps; 3157 3158 err = bpf_prog_alloc_id(prog); 3159 if (err) 3160 goto free_used_maps; 3161 3162 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 3163 * effectively publicly exposed. However, retrieving via 3164 * bpf_prog_get_fd_by_id() will take another reference, 3165 * therefore it cannot be gone underneath us. 3166 * 3167 * Only for the time /after/ successful bpf_prog_new_fd() 3168 * and before returning to userspace, we might just hold 3169 * one reference and any parallel close on that fd could 3170 * rip everything out. Hence, below notifications must 3171 * happen before bpf_prog_new_fd(). 3172 * 3173 * Also, any failure handling from this point onwards must 3174 * be using bpf_prog_put() given the program is exposed. 3175 */ 3176 bpf_prog_kallsyms_add(prog); 3177 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 3178 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 3179 3180 err = bpf_prog_new_fd(prog); 3181 if (err < 0) 3182 bpf_prog_put(prog); 3183 return err; 3184 3185 free_used_maps: 3186 /* In case we have subprogs, we need to wait for a grace 3187 * period before we can tear down JIT memory since symbols 3188 * are already exposed under kallsyms. 3189 */ 3190 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 3191 return err; 3192 3193 free_prog: 3194 free_uid(prog->aux->user); 3195 if (prog->aux->attach_btf) 3196 btf_put(prog->aux->attach_btf); 3197 bpf_prog_free(prog); 3198 put_token: 3199 bpf_token_put(token); 3200 return err; 3201 } 3202 3203 #define BPF_OBJ_LAST_FIELD path_fd 3204 3205 static int bpf_obj_pin(const union bpf_attr *attr) 3206 { 3207 int path_fd; 3208 3209 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3210 return -EINVAL; 3211 3212 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3213 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3214 return -EINVAL; 3215 3216 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3217 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3218 u64_to_user_ptr(attr->pathname)); 3219 } 3220 3221 static int bpf_obj_get(const union bpf_attr *attr) 3222 { 3223 int path_fd; 3224 3225 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3226 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3227 return -EINVAL; 3228 3229 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3230 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3231 return -EINVAL; 3232 3233 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3234 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3235 attr->file_flags); 3236 } 3237 3238 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3239 * "sleepable" semantics, which normally would mean that BPF link's attach 3240 * hook can dereference link or link's underlying program for some time after 3241 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3242 * BPF program itself can be non-sleepable, yet, because it's transitively 3243 * reachable through BPF link, its freeing has to be delayed until after RCU 3244 * Tasks Trace GP. 3245 */ 3246 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3247 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3248 enum bpf_attach_type attach_type, bool sleepable) 3249 { 3250 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3251 atomic64_set(&link->refcnt, 1); 3252 link->type = type; 3253 link->sleepable = sleepable; 3254 link->id = 0; 3255 link->ops = ops; 3256 link->prog = prog; 3257 link->attach_type = attach_type; 3258 } 3259 3260 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3261 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3262 enum bpf_attach_type attach_type) 3263 { 3264 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); 3265 } 3266 3267 void bpf_tramp_link_init(struct bpf_tramp_link *link, enum bpf_link_type type, 3268 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3269 enum bpf_attach_type attach_type, u64 cookie) 3270 { 3271 bpf_link_init(&link->link, type, ops, prog, attach_type); 3272 link->node.link = &link->link; 3273 link->node.cookie = cookie; 3274 } 3275 3276 static void bpf_link_free_id(int id) 3277 { 3278 if (!id) 3279 return; 3280 3281 spin_lock_bh(&link_idr_lock); 3282 idr_remove(&link_idr, id); 3283 spin_unlock_bh(&link_idr_lock); 3284 } 3285 3286 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3287 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3288 * anon_inode's release() call. This helper marks bpf_link as 3289 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3290 * is not decremented, it's the responsibility of a calling code that failed 3291 * to complete bpf_link initialization. 3292 * This helper eventually calls link's dealloc callback, but does not call 3293 * link's release callback. 3294 */ 3295 void bpf_link_cleanup(struct bpf_link_primer *primer) 3296 { 3297 primer->link->prog = NULL; 3298 bpf_link_free_id(primer->id); 3299 fput(primer->file); 3300 put_unused_fd(primer->fd); 3301 } 3302 3303 void bpf_link_inc(struct bpf_link *link) 3304 { 3305 atomic64_inc(&link->refcnt); 3306 } 3307 3308 static void bpf_link_dealloc(struct bpf_link *link) 3309 { 3310 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3311 if (link->prog) 3312 bpf_prog_put(link->prog); 3313 3314 /* free bpf_link and its containing memory */ 3315 if (link->ops->dealloc_deferred) 3316 link->ops->dealloc_deferred(link); 3317 else 3318 link->ops->dealloc(link); 3319 } 3320 3321 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3322 { 3323 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3324 3325 bpf_link_dealloc(link); 3326 } 3327 3328 static bool bpf_link_is_tracepoint(struct bpf_link *link) 3329 { 3330 /* 3331 * Only these combinations support a tracepoint bpf_link. 3332 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use 3333 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see 3334 * bpf_raw_tp_link_attach(). 3335 */ 3336 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT || 3337 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP); 3338 } 3339 3340 /* bpf_link_free is guaranteed to be called from process context */ 3341 static void bpf_link_free(struct bpf_link *link) 3342 { 3343 const struct bpf_link_ops *ops = link->ops; 3344 3345 bpf_link_free_id(link->id); 3346 /* detach BPF program, clean up used resources */ 3347 if (link->prog) 3348 ops->release(link); 3349 if (ops->dealloc_deferred) { 3350 /* 3351 * Schedule BPF link deallocation, which will only then 3352 * trigger putting BPF program refcount. 3353 * If underlying BPF program is sleepable or BPF link's target 3354 * attach hookpoint is sleepable or otherwise requires RCU GPs 3355 * to ensure link and its underlying BPF program is not 3356 * reachable anymore, we need to first wait for RCU tasks 3357 * trace sync, and then go through "classic" RCU grace period. 3358 * 3359 * For tracepoint BPF links, we need to go through SRCU grace 3360 * period wait instead when non-faultable tracepoint is used. We 3361 * don't need to chain SRCU grace period waits, however, for the 3362 * faultable case, since it exclusively uses RCU Tasks Trace. 3363 */ 3364 if (link->sleepable || (link->prog && link->prog->sleepable)) 3365 /* RCU Tasks Trace grace period implies RCU grace period. */ 3366 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3367 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */ 3368 else if (bpf_link_is_tracepoint(link)) 3369 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3370 else 3371 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3372 } else if (ops->dealloc) { 3373 bpf_link_dealloc(link); 3374 } 3375 } 3376 3377 static void bpf_link_put_deferred(struct work_struct *work) 3378 { 3379 struct bpf_link *link = container_of(work, struct bpf_link, work); 3380 3381 bpf_link_free(link); 3382 } 3383 3384 /* bpf_link_put might be called from atomic context. It needs to be called 3385 * from sleepable context in order to acquire sleeping locks during the process. 3386 */ 3387 void bpf_link_put(struct bpf_link *link) 3388 { 3389 if (!atomic64_dec_and_test(&link->refcnt)) 3390 return; 3391 3392 INIT_WORK(&link->work, bpf_link_put_deferred); 3393 schedule_work(&link->work); 3394 } 3395 EXPORT_SYMBOL(bpf_link_put); 3396 3397 static void bpf_link_put_direct(struct bpf_link *link) 3398 { 3399 if (!atomic64_dec_and_test(&link->refcnt)) 3400 return; 3401 bpf_link_free(link); 3402 } 3403 3404 static int bpf_link_release(struct inode *inode, struct file *filp) 3405 { 3406 struct bpf_link *link = filp->private_data; 3407 3408 bpf_link_put_direct(link); 3409 return 0; 3410 } 3411 3412 #ifdef CONFIG_PROC_FS 3413 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3414 #define BPF_MAP_TYPE(_id, _ops) 3415 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3416 static const char *bpf_link_type_strs[] = { 3417 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3418 #include <linux/bpf_types.h> 3419 }; 3420 #undef BPF_PROG_TYPE 3421 #undef BPF_MAP_TYPE 3422 #undef BPF_LINK_TYPE 3423 3424 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3425 { 3426 const struct bpf_link *link = filp->private_data; 3427 const struct bpf_prog *prog; 3428 enum bpf_link_type type = link->type; 3429 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3430 u32 prog_id = 0; 3431 3432 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3433 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) 3434 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? 3435 "kretprobe_multi" : "kprobe_multi"); 3436 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) 3437 seq_printf(m, "link_type:\t%s\n", link->flags & BPF_F_UPROBE_MULTI_RETURN ? 3438 "uretprobe_multi" : "uprobe_multi"); 3439 else 3440 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3441 } else { 3442 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3443 seq_printf(m, "link_type:\t<%u>\n", type); 3444 } 3445 seq_printf(m, "link_id:\t%u\n", link->id); 3446 3447 rcu_read_lock(); 3448 prog = READ_ONCE(link->prog); 3449 if (prog) { 3450 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3451 prog_id = prog->aux->id; 3452 } 3453 rcu_read_unlock(); 3454 3455 if (prog) { 3456 seq_printf(m, 3457 "prog_tag:\t%s\n" 3458 "prog_id:\t%u\n", 3459 prog_tag, 3460 prog_id); 3461 } 3462 if (link->ops->show_fdinfo) 3463 link->ops->show_fdinfo(link, m); 3464 } 3465 #endif 3466 3467 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3468 { 3469 struct bpf_link *link = file->private_data; 3470 3471 return link->ops->poll(file, pts); 3472 } 3473 3474 static const struct file_operations bpf_link_fops = { 3475 #ifdef CONFIG_PROC_FS 3476 .show_fdinfo = bpf_link_show_fdinfo, 3477 #endif 3478 .release = bpf_link_release, 3479 .read = bpf_dummy_read, 3480 .write = bpf_dummy_write, 3481 }; 3482 3483 static const struct file_operations bpf_link_fops_poll = { 3484 #ifdef CONFIG_PROC_FS 3485 .show_fdinfo = bpf_link_show_fdinfo, 3486 #endif 3487 .release = bpf_link_release, 3488 .read = bpf_dummy_read, 3489 .write = bpf_dummy_write, 3490 .poll = bpf_link_poll, 3491 }; 3492 3493 static int bpf_link_alloc_id(struct bpf_link *link) 3494 { 3495 int id; 3496 3497 idr_preload(GFP_KERNEL); 3498 spin_lock_bh(&link_idr_lock); 3499 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3500 spin_unlock_bh(&link_idr_lock); 3501 idr_preload_end(); 3502 3503 return id; 3504 } 3505 3506 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3507 * reserving unused FD and allocating ID from link_idr. This is to be paired 3508 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3509 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3510 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3511 * transient state is passed around in struct bpf_link_primer. 3512 * This is preferred way to create and initialize bpf_link, especially when 3513 * there are complicated and expensive operations in between creating bpf_link 3514 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3515 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3516 * expensive (and potentially failing) roll back operations in a rare case 3517 * that file, FD, or ID can't be allocated. 3518 */ 3519 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3520 { 3521 struct file *file; 3522 int fd, id; 3523 3524 fd = get_unused_fd_flags(O_CLOEXEC); 3525 if (fd < 0) 3526 return fd; 3527 3528 id = bpf_link_alloc_id(link); 3529 if (id < 0) { 3530 put_unused_fd(fd); 3531 return id; 3532 } 3533 3534 file = anon_inode_getfile("bpf_link", 3535 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3536 link, O_CLOEXEC); 3537 if (IS_ERR(file)) { 3538 bpf_link_free_id(id); 3539 put_unused_fd(fd); 3540 return PTR_ERR(file); 3541 } 3542 3543 primer->link = link; 3544 primer->file = file; 3545 primer->fd = fd; 3546 primer->id = id; 3547 return 0; 3548 } 3549 3550 int bpf_link_settle(struct bpf_link_primer *primer) 3551 { 3552 /* make bpf_link fetchable by ID */ 3553 spin_lock_bh(&link_idr_lock); 3554 primer->link->id = primer->id; 3555 spin_unlock_bh(&link_idr_lock); 3556 /* make bpf_link fetchable by FD */ 3557 fd_install(primer->fd, primer->file); 3558 /* pass through installed FD */ 3559 return primer->fd; 3560 } 3561 3562 int bpf_link_new_fd(struct bpf_link *link) 3563 { 3564 return anon_inode_getfd("bpf-link", 3565 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3566 link, O_CLOEXEC); 3567 } 3568 3569 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3570 { 3571 CLASS(fd, f)(ufd); 3572 struct bpf_link *link; 3573 3574 if (fd_empty(f)) 3575 return ERR_PTR(-EBADF); 3576 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3577 return ERR_PTR(-EINVAL); 3578 3579 link = fd_file(f)->private_data; 3580 bpf_link_inc(link); 3581 return link; 3582 } 3583 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); 3584 3585 static void bpf_tracing_link_release(struct bpf_link *link) 3586 { 3587 struct bpf_tracing_link *tr_link = 3588 container_of(link, struct bpf_tracing_link, link.link); 3589 int err; 3590 3591 err = bpf_trampoline_unlink_prog(&tr_link->link.node, 3592 tr_link->trampoline, 3593 tr_link->tgt_prog); 3594 WARN_ONCE(err, "bpf_trampoline_unlink_prog failed: %d\n", err); 3595 3596 bpf_trampoline_put(tr_link->trampoline); 3597 3598 /* tgt_prog is NULL if target is a kernel function */ 3599 if (tr_link->tgt_prog) 3600 bpf_prog_put(tr_link->tgt_prog); 3601 } 3602 3603 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3604 { 3605 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3606 3607 kfree(tr_link); 3608 } 3609 3610 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3611 struct seq_file *seq) 3612 { 3613 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3614 3615 u32 target_btf_id, target_obj_id; 3616 3617 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3618 &target_obj_id, &target_btf_id); 3619 seq_printf(seq, 3620 "attach_type:\t%d\n" 3621 "target_obj_id:\t%u\n" 3622 "target_btf_id:\t%u\n" 3623 "cookie:\t%llu\n", 3624 link->attach_type, 3625 target_obj_id, 3626 target_btf_id, 3627 tr_link->link.node.cookie); 3628 } 3629 3630 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3631 struct bpf_link_info *info) 3632 { 3633 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3634 3635 info->tracing.attach_type = link->attach_type; 3636 info->tracing.cookie = tr_link->link.node.cookie; 3637 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3638 &info->tracing.target_obj_id, 3639 &info->tracing.target_btf_id); 3640 3641 return 0; 3642 } 3643 3644 static const struct bpf_link_ops bpf_tracing_link_lops = { 3645 .release = bpf_tracing_link_release, 3646 .dealloc = bpf_tracing_link_dealloc, 3647 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3648 .fill_link_info = bpf_tracing_link_fill_link_info, 3649 }; 3650 3651 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3652 int tgt_prog_fd, 3653 u32 btf_id, 3654 u64 bpf_cookie, 3655 enum bpf_attach_type attach_type) 3656 { 3657 struct bpf_link_primer link_primer; 3658 struct bpf_prog *tgt_prog = NULL; 3659 struct bpf_trampoline *tr = NULL; 3660 struct bpf_tracing_link *link; 3661 u64 key = 0; 3662 int err; 3663 3664 switch (prog->type) { 3665 case BPF_PROG_TYPE_TRACING: 3666 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3667 prog->expected_attach_type != BPF_TRACE_FEXIT && 3668 prog->expected_attach_type != BPF_TRACE_FSESSION && 3669 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3670 err = -EINVAL; 3671 goto out_put_prog; 3672 } 3673 break; 3674 case BPF_PROG_TYPE_EXT: 3675 if (prog->expected_attach_type != 0) { 3676 err = -EINVAL; 3677 goto out_put_prog; 3678 } 3679 break; 3680 case BPF_PROG_TYPE_LSM: 3681 if (prog->expected_attach_type != BPF_LSM_MAC) { 3682 err = -EINVAL; 3683 goto out_put_prog; 3684 } 3685 break; 3686 default: 3687 err = -EINVAL; 3688 goto out_put_prog; 3689 } 3690 3691 if (!!tgt_prog_fd != !!btf_id) { 3692 err = -EINVAL; 3693 goto out_put_prog; 3694 } 3695 3696 if (tgt_prog_fd) { 3697 /* 3698 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3699 * part would be changed to implement the same for 3700 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3701 * attach_tracing_prog flag is set. 3702 */ 3703 if (prog->type != BPF_PROG_TYPE_EXT) { 3704 err = -EINVAL; 3705 goto out_put_prog; 3706 } 3707 3708 tgt_prog = bpf_prog_get(tgt_prog_fd); 3709 if (IS_ERR(tgt_prog)) { 3710 err = PTR_ERR(tgt_prog); 3711 tgt_prog = NULL; 3712 goto out_put_prog; 3713 } 3714 3715 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3716 } 3717 3718 link = kzalloc_obj(*link, GFP_USER); 3719 if (!link) { 3720 err = -ENOMEM; 3721 goto out_put_prog; 3722 } 3723 bpf_tramp_link_init(&link->link, BPF_LINK_TYPE_TRACING, 3724 &bpf_tracing_link_lops, prog, attach_type, bpf_cookie); 3725 3726 if (prog->expected_attach_type == BPF_TRACE_FSESSION) { 3727 link->fexit.link = &link->link.link; 3728 link->fexit.cookie = bpf_cookie; 3729 } 3730 3731 mutex_lock(&prog->aux->dst_mutex); 3732 3733 /* There are a few possible cases here: 3734 * 3735 * - if prog->aux->dst_trampoline is set, the program was just loaded 3736 * and not yet attached to anything, so we can use the values stored 3737 * in prog->aux 3738 * 3739 * - if prog->aux->dst_trampoline is NULL, the program has already been 3740 * attached to a target and its initial target was cleared (below) 3741 * 3742 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3743 * target_btf_id using the link_create API. 3744 * 3745 * - if tgt_prog == NULL when this function was called using the old 3746 * raw_tracepoint_open API, and we need a target from prog->aux 3747 * 3748 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3749 * was detached and is going for re-attachment. 3750 * 3751 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3752 * are NULL, then program was already attached and user did not provide 3753 * tgt_prog_fd so we have no way to find out or create trampoline 3754 */ 3755 if (!prog->aux->dst_trampoline && !tgt_prog) { 3756 /* 3757 * Allow re-attach for TRACING and LSM programs. If it's 3758 * currently linked, bpf_trampoline_link_prog will fail. 3759 * EXT programs need to specify tgt_prog_fd, so they 3760 * re-attach in separate code path. 3761 */ 3762 if (prog->type != BPF_PROG_TYPE_TRACING && 3763 prog->type != BPF_PROG_TYPE_LSM) { 3764 err = -EINVAL; 3765 goto out_unlock; 3766 } 3767 /* We can allow re-attach only if we have valid attach_btf. */ 3768 if (!prog->aux->attach_btf) { 3769 err = -EINVAL; 3770 goto out_unlock; 3771 } 3772 btf_id = prog->aux->attach_btf_id; 3773 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3774 } 3775 3776 if (!prog->aux->dst_trampoline || 3777 (key && key != prog->aux->dst_trampoline->key)) { 3778 /* If there is no saved target, or the specified target is 3779 * different from the destination specified at load time, we 3780 * need a new trampoline and a check for compatibility 3781 */ 3782 struct bpf_attach_target_info tgt_info = {}; 3783 3784 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3785 &tgt_info); 3786 if (err) 3787 goto out_unlock; 3788 3789 if (tgt_info.tgt_mod) { 3790 module_put(prog->aux->mod); 3791 prog->aux->mod = tgt_info.tgt_mod; 3792 } 3793 3794 tr = bpf_trampoline_get(key, &tgt_info); 3795 if (!tr) { 3796 err = -ENOMEM; 3797 goto out_unlock; 3798 } 3799 } else { 3800 /* The caller didn't specify a target, or the target was the 3801 * same as the destination supplied during program load. This 3802 * means we can reuse the trampoline and reference from program 3803 * load time, and there is no need to allocate a new one. This 3804 * can only happen once for any program, as the saved values in 3805 * prog->aux are cleared below. 3806 */ 3807 tr = prog->aux->dst_trampoline; 3808 tgt_prog = prog->aux->dst_prog; 3809 } 3810 /* 3811 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true 3812 * freplace prog. Without this check, kprobe_write_ctx=true freplace 3813 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and 3814 * then modify the registers of the kprobe prog's target kernel 3815 * function. 3816 * 3817 * This also blocks the combination of uprobe+freplace, because it is 3818 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe 3819 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by 3820 * the target perf event flags in __perf_event_set_bpf_prog(). 3821 */ 3822 if (prog->type == BPF_PROG_TYPE_EXT && 3823 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) { 3824 err = -EINVAL; 3825 goto out_unlock; 3826 } 3827 3828 err = bpf_link_prime(&link->link.link, &link_primer); 3829 if (err) 3830 goto out_unlock; 3831 3832 err = bpf_trampoline_link_prog(&link->link.node, tr, tgt_prog); 3833 if (err) { 3834 bpf_link_cleanup(&link_primer); 3835 link = NULL; 3836 goto out_unlock; 3837 } 3838 3839 link->tgt_prog = tgt_prog; 3840 link->trampoline = tr; 3841 3842 /* Always clear the trampoline and target prog from prog->aux to make 3843 * sure the original attach destination is not kept alive after a 3844 * program is (re-)attached to another target. 3845 */ 3846 if (prog->aux->dst_prog && 3847 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3848 /* got extra prog ref from syscall, or attaching to different prog */ 3849 bpf_prog_put(prog->aux->dst_prog); 3850 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3851 /* we allocated a new trampoline, so free the old one */ 3852 bpf_trampoline_put(prog->aux->dst_trampoline); 3853 3854 prog->aux->dst_prog = NULL; 3855 prog->aux->dst_trampoline = NULL; 3856 mutex_unlock(&prog->aux->dst_mutex); 3857 3858 return bpf_link_settle(&link_primer); 3859 out_unlock: 3860 if (tr && tr != prog->aux->dst_trampoline) 3861 bpf_trampoline_put(tr); 3862 mutex_unlock(&prog->aux->dst_mutex); 3863 kfree(link); 3864 out_put_prog: 3865 if (tgt_prog_fd && tgt_prog) 3866 bpf_prog_put(tgt_prog); 3867 return err; 3868 } 3869 3870 static void bpf_raw_tp_link_release(struct bpf_link *link) 3871 { 3872 struct bpf_raw_tp_link *raw_tp = 3873 container_of(link, struct bpf_raw_tp_link, link); 3874 3875 bpf_probe_unregister(raw_tp->btp, raw_tp); 3876 bpf_put_raw_tracepoint(raw_tp->btp); 3877 } 3878 3879 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3880 { 3881 struct bpf_raw_tp_link *raw_tp = 3882 container_of(link, struct bpf_raw_tp_link, link); 3883 3884 kfree(raw_tp); 3885 } 3886 3887 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3888 struct seq_file *seq) 3889 { 3890 struct bpf_raw_tp_link *raw_tp_link = 3891 container_of(link, struct bpf_raw_tp_link, link); 3892 3893 seq_printf(seq, 3894 "tp_name:\t%s\n" 3895 "cookie:\t%llu\n", 3896 raw_tp_link->btp->tp->name, 3897 raw_tp_link->cookie); 3898 } 3899 3900 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3901 u32 len) 3902 { 3903 if (ulen >= len + 1) { 3904 if (copy_to_user(ubuf, buf, len + 1)) 3905 return -EFAULT; 3906 } else { 3907 char zero = '\0'; 3908 3909 if (copy_to_user(ubuf, buf, ulen - 1)) 3910 return -EFAULT; 3911 if (put_user(zero, ubuf + ulen - 1)) 3912 return -EFAULT; 3913 return -ENOSPC; 3914 } 3915 3916 return 0; 3917 } 3918 3919 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3920 struct bpf_link_info *info) 3921 { 3922 struct bpf_raw_tp_link *raw_tp_link = 3923 container_of(link, struct bpf_raw_tp_link, link); 3924 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3925 const char *tp_name = raw_tp_link->btp->tp->name; 3926 u32 ulen = info->raw_tracepoint.tp_name_len; 3927 size_t tp_len = strlen(tp_name); 3928 3929 if (!ulen ^ !ubuf) 3930 return -EINVAL; 3931 3932 info->raw_tracepoint.tp_name_len = tp_len + 1; 3933 info->raw_tracepoint.cookie = raw_tp_link->cookie; 3934 3935 if (!ubuf) 3936 return 0; 3937 3938 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3939 } 3940 3941 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3942 .release = bpf_raw_tp_link_release, 3943 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3944 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3945 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3946 }; 3947 3948 #ifdef CONFIG_PERF_EVENTS 3949 struct bpf_perf_link { 3950 struct bpf_link link; 3951 struct file *perf_file; 3952 }; 3953 3954 static void bpf_perf_link_release(struct bpf_link *link) 3955 { 3956 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3957 struct perf_event *event = perf_link->perf_file->private_data; 3958 3959 perf_event_free_bpf_prog(event); 3960 fput(perf_link->perf_file); 3961 } 3962 3963 static void bpf_perf_link_dealloc(struct bpf_link *link) 3964 { 3965 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3966 3967 kfree(perf_link); 3968 } 3969 3970 static int bpf_perf_link_fill_common(const struct perf_event *event, 3971 char __user *uname, u32 *ulenp, 3972 u64 *probe_offset, u64 *probe_addr, 3973 u32 *fd_type, unsigned long *missed) 3974 { 3975 const char *buf; 3976 u32 prog_id, ulen; 3977 size_t len; 3978 int err; 3979 3980 ulen = *ulenp; 3981 if (!ulen ^ !uname) 3982 return -EINVAL; 3983 3984 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3985 probe_offset, probe_addr, missed); 3986 if (err) 3987 return err; 3988 3989 if (buf) { 3990 len = strlen(buf); 3991 *ulenp = len + 1; 3992 } else { 3993 *ulenp = 1; 3994 } 3995 if (!uname) 3996 return 0; 3997 3998 if (buf) { 3999 err = bpf_copy_to_user(uname, buf, ulen, len); 4000 if (err) 4001 return err; 4002 } else { 4003 char zero = '\0'; 4004 4005 if (put_user(zero, uname)) 4006 return -EFAULT; 4007 } 4008 return 0; 4009 } 4010 4011 #ifdef CONFIG_KPROBE_EVENTS 4012 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 4013 struct bpf_link_info *info) 4014 { 4015 unsigned long missed; 4016 char __user *uname; 4017 u64 addr, offset; 4018 u32 ulen, type; 4019 int err; 4020 4021 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 4022 ulen = info->perf_event.kprobe.name_len; 4023 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 4024 &type, &missed); 4025 if (err) 4026 return err; 4027 if (type == BPF_FD_TYPE_KRETPROBE) 4028 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 4029 else 4030 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 4031 info->perf_event.kprobe.name_len = ulen; 4032 info->perf_event.kprobe.offset = offset; 4033 info->perf_event.kprobe.missed = missed; 4034 if (!kallsyms_show_value(current_cred())) 4035 addr = 0; 4036 info->perf_event.kprobe.addr = addr; 4037 info->perf_event.kprobe.cookie = event->bpf_cookie; 4038 return 0; 4039 } 4040 4041 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, 4042 struct seq_file *seq) 4043 { 4044 const char *name; 4045 int err; 4046 u32 prog_id, type; 4047 u64 offset, addr; 4048 unsigned long missed; 4049 4050 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4051 &offset, &addr, &missed); 4052 if (err) 4053 return; 4054 4055 seq_printf(seq, 4056 "name:\t%s\n" 4057 "offset:\t%#llx\n" 4058 "missed:\t%lu\n" 4059 "addr:\t%#llx\n" 4060 "event_type:\t%s\n" 4061 "cookie:\t%llu\n", 4062 name, offset, missed, addr, 4063 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", 4064 event->bpf_cookie); 4065 } 4066 #endif 4067 4068 #ifdef CONFIG_UPROBE_EVENTS 4069 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 4070 struct bpf_link_info *info) 4071 { 4072 u64 ref_ctr_offset, offset; 4073 char __user *uname; 4074 u32 ulen, type; 4075 int err; 4076 4077 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 4078 ulen = info->perf_event.uprobe.name_len; 4079 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, 4080 &type, NULL); 4081 if (err) 4082 return err; 4083 4084 if (type == BPF_FD_TYPE_URETPROBE) 4085 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 4086 else 4087 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 4088 info->perf_event.uprobe.name_len = ulen; 4089 info->perf_event.uprobe.offset = offset; 4090 info->perf_event.uprobe.cookie = event->bpf_cookie; 4091 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; 4092 return 0; 4093 } 4094 4095 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, 4096 struct seq_file *seq) 4097 { 4098 const char *name; 4099 int err; 4100 u32 prog_id, type; 4101 u64 offset, ref_ctr_offset; 4102 unsigned long missed; 4103 4104 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4105 &offset, &ref_ctr_offset, &missed); 4106 if (err) 4107 return; 4108 4109 seq_printf(seq, 4110 "name:\t%s\n" 4111 "offset:\t%#llx\n" 4112 "ref_ctr_offset:\t%#llx\n" 4113 "event_type:\t%s\n" 4114 "cookie:\t%llu\n", 4115 name, offset, ref_ctr_offset, 4116 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", 4117 event->bpf_cookie); 4118 } 4119 #endif 4120 4121 static int bpf_perf_link_fill_probe(const struct perf_event *event, 4122 struct bpf_link_info *info) 4123 { 4124 #ifdef CONFIG_KPROBE_EVENTS 4125 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4126 return bpf_perf_link_fill_kprobe(event, info); 4127 #endif 4128 #ifdef CONFIG_UPROBE_EVENTS 4129 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4130 return bpf_perf_link_fill_uprobe(event, info); 4131 #endif 4132 return -EOPNOTSUPP; 4133 } 4134 4135 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 4136 struct bpf_link_info *info) 4137 { 4138 char __user *uname; 4139 u32 ulen; 4140 int err; 4141 4142 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 4143 ulen = info->perf_event.tracepoint.name_len; 4144 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 4145 if (err) 4146 return err; 4147 4148 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 4149 info->perf_event.tracepoint.name_len = ulen; 4150 info->perf_event.tracepoint.cookie = event->bpf_cookie; 4151 return 0; 4152 } 4153 4154 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 4155 struct bpf_link_info *info) 4156 { 4157 info->perf_event.event.type = event->attr.type; 4158 info->perf_event.event.config = event->attr.config; 4159 info->perf_event.event.cookie = event->bpf_cookie; 4160 info->perf_event.type = BPF_PERF_EVENT_EVENT; 4161 return 0; 4162 } 4163 4164 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 4165 struct bpf_link_info *info) 4166 { 4167 struct bpf_perf_link *perf_link; 4168 const struct perf_event *event; 4169 4170 perf_link = container_of(link, struct bpf_perf_link, link); 4171 event = perf_get_event(perf_link->perf_file); 4172 if (IS_ERR(event)) 4173 return PTR_ERR(event); 4174 4175 switch (event->prog->type) { 4176 case BPF_PROG_TYPE_PERF_EVENT: 4177 return bpf_perf_link_fill_perf_event(event, info); 4178 case BPF_PROG_TYPE_TRACEPOINT: 4179 return bpf_perf_link_fill_tracepoint(event, info); 4180 case BPF_PROG_TYPE_KPROBE: 4181 return bpf_perf_link_fill_probe(event, info); 4182 default: 4183 return -EOPNOTSUPP; 4184 } 4185 } 4186 4187 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, 4188 struct seq_file *seq) 4189 { 4190 seq_printf(seq, 4191 "type:\t%u\n" 4192 "config:\t%llu\n" 4193 "event_type:\t%s\n" 4194 "cookie:\t%llu\n", 4195 event->attr.type, event->attr.config, 4196 "event", event->bpf_cookie); 4197 } 4198 4199 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, 4200 struct seq_file *seq) 4201 { 4202 int err; 4203 const char *name; 4204 u32 prog_id; 4205 4206 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, 4207 NULL, NULL); 4208 if (err) 4209 return; 4210 4211 seq_printf(seq, 4212 "tp_name:\t%s\n" 4213 "event_type:\t%s\n" 4214 "cookie:\t%llu\n", 4215 name, "tracepoint", event->bpf_cookie); 4216 } 4217 4218 static void bpf_probe_link_show_fdinfo(const struct perf_event *event, 4219 struct seq_file *seq) 4220 { 4221 #ifdef CONFIG_KPROBE_EVENTS 4222 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4223 return bpf_perf_link_fdinfo_kprobe(event, seq); 4224 #endif 4225 4226 #ifdef CONFIG_UPROBE_EVENTS 4227 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4228 return bpf_perf_link_fdinfo_uprobe(event, seq); 4229 #endif 4230 } 4231 4232 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, 4233 struct seq_file *seq) 4234 { 4235 struct bpf_perf_link *perf_link; 4236 const struct perf_event *event; 4237 4238 perf_link = container_of(link, struct bpf_perf_link, link); 4239 event = perf_get_event(perf_link->perf_file); 4240 if (IS_ERR(event)) 4241 return; 4242 4243 switch (event->prog->type) { 4244 case BPF_PROG_TYPE_PERF_EVENT: 4245 return bpf_perf_event_link_show_fdinfo(event, seq); 4246 case BPF_PROG_TYPE_TRACEPOINT: 4247 return bpf_tracepoint_link_show_fdinfo(event, seq); 4248 case BPF_PROG_TYPE_KPROBE: 4249 return bpf_probe_link_show_fdinfo(event, seq); 4250 default: 4251 return; 4252 } 4253 } 4254 4255 static const struct bpf_link_ops bpf_perf_link_lops = { 4256 .release = bpf_perf_link_release, 4257 .dealloc = bpf_perf_link_dealloc, 4258 .fill_link_info = bpf_perf_link_fill_link_info, 4259 .show_fdinfo = bpf_perf_link_show_fdinfo, 4260 }; 4261 4262 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4263 { 4264 struct bpf_link_primer link_primer; 4265 struct bpf_perf_link *link; 4266 struct perf_event *event; 4267 struct file *perf_file; 4268 int err; 4269 4270 if (attr->link_create.flags) 4271 return -EINVAL; 4272 4273 perf_file = perf_event_get(attr->link_create.target_fd); 4274 if (IS_ERR(perf_file)) 4275 return PTR_ERR(perf_file); 4276 4277 link = kzalloc_obj(*link, GFP_USER); 4278 if (!link) { 4279 err = -ENOMEM; 4280 goto out_put_file; 4281 } 4282 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, 4283 attr->link_create.attach_type); 4284 link->perf_file = perf_file; 4285 4286 err = bpf_link_prime(&link->link, &link_primer); 4287 if (err) { 4288 kfree(link); 4289 goto out_put_file; 4290 } 4291 4292 event = perf_file->private_data; 4293 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 4294 if (err) { 4295 bpf_link_cleanup(&link_primer); 4296 goto out_put_file; 4297 } 4298 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 4299 bpf_prog_inc(prog); 4300 4301 return bpf_link_settle(&link_primer); 4302 4303 out_put_file: 4304 fput(perf_file); 4305 return err; 4306 } 4307 #else 4308 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4309 { 4310 return -EOPNOTSUPP; 4311 } 4312 #endif /* CONFIG_PERF_EVENTS */ 4313 4314 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 4315 const char __user *user_tp_name, u64 cookie, 4316 enum bpf_attach_type attach_type) 4317 { 4318 struct bpf_link_primer link_primer; 4319 struct bpf_raw_tp_link *link; 4320 struct bpf_raw_event_map *btp; 4321 const char *tp_name; 4322 char buf[128]; 4323 int err; 4324 4325 switch (prog->type) { 4326 case BPF_PROG_TYPE_TRACING: 4327 case BPF_PROG_TYPE_EXT: 4328 case BPF_PROG_TYPE_LSM: 4329 if (user_tp_name) 4330 /* The attach point for this category of programs 4331 * should be specified via btf_id during program load. 4332 */ 4333 return -EINVAL; 4334 if (prog->type == BPF_PROG_TYPE_TRACING && 4335 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 4336 tp_name = prog->aux->attach_func_name; 4337 break; 4338 } 4339 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); 4340 case BPF_PROG_TYPE_RAW_TRACEPOINT: 4341 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 4342 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 4343 return -EFAULT; 4344 buf[sizeof(buf) - 1] = 0; 4345 tp_name = buf; 4346 break; 4347 default: 4348 return -EINVAL; 4349 } 4350 4351 btp = bpf_get_raw_tracepoint(tp_name); 4352 if (!btp) 4353 return -ENOENT; 4354 4355 if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) { 4356 bpf_put_raw_tracepoint(btp); 4357 return -EINVAL; 4358 } 4359 4360 link = kzalloc_obj(*link, GFP_USER); 4361 if (!link) { 4362 err = -ENOMEM; 4363 goto out_put_btp; 4364 } 4365 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 4366 &bpf_raw_tp_link_lops, prog, attach_type, 4367 tracepoint_is_faultable(btp->tp)); 4368 link->btp = btp; 4369 link->cookie = cookie; 4370 4371 err = bpf_link_prime(&link->link, &link_primer); 4372 if (err) { 4373 kfree(link); 4374 goto out_put_btp; 4375 } 4376 4377 err = bpf_probe_register(link->btp, link); 4378 if (err) { 4379 bpf_link_cleanup(&link_primer); 4380 goto out_put_btp; 4381 } 4382 4383 return bpf_link_settle(&link_primer); 4384 4385 out_put_btp: 4386 bpf_put_raw_tracepoint(btp); 4387 return err; 4388 } 4389 4390 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 4391 4392 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4393 { 4394 struct bpf_prog *prog; 4395 void __user *tp_name; 4396 __u64 cookie; 4397 int fd; 4398 4399 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4400 return -EINVAL; 4401 4402 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4403 if (IS_ERR(prog)) 4404 return PTR_ERR(prog); 4405 4406 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4407 cookie = attr->raw_tracepoint.cookie; 4408 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); 4409 if (fd < 0) 4410 bpf_prog_put(prog); 4411 return fd; 4412 } 4413 4414 static enum bpf_prog_type 4415 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4416 { 4417 switch (attach_type) { 4418 case BPF_CGROUP_INET_INGRESS: 4419 case BPF_CGROUP_INET_EGRESS: 4420 return BPF_PROG_TYPE_CGROUP_SKB; 4421 case BPF_CGROUP_INET_SOCK_CREATE: 4422 case BPF_CGROUP_INET_SOCK_RELEASE: 4423 case BPF_CGROUP_INET4_POST_BIND: 4424 case BPF_CGROUP_INET6_POST_BIND: 4425 return BPF_PROG_TYPE_CGROUP_SOCK; 4426 case BPF_CGROUP_INET4_BIND: 4427 case BPF_CGROUP_INET6_BIND: 4428 case BPF_CGROUP_INET4_CONNECT: 4429 case BPF_CGROUP_INET6_CONNECT: 4430 case BPF_CGROUP_UNIX_CONNECT: 4431 case BPF_CGROUP_INET4_GETPEERNAME: 4432 case BPF_CGROUP_INET6_GETPEERNAME: 4433 case BPF_CGROUP_UNIX_GETPEERNAME: 4434 case BPF_CGROUP_INET4_GETSOCKNAME: 4435 case BPF_CGROUP_INET6_GETSOCKNAME: 4436 case BPF_CGROUP_UNIX_GETSOCKNAME: 4437 case BPF_CGROUP_UDP4_SENDMSG: 4438 case BPF_CGROUP_UDP6_SENDMSG: 4439 case BPF_CGROUP_UNIX_SENDMSG: 4440 case BPF_CGROUP_UDP4_RECVMSG: 4441 case BPF_CGROUP_UDP6_RECVMSG: 4442 case BPF_CGROUP_UNIX_RECVMSG: 4443 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4444 case BPF_CGROUP_SOCK_OPS: 4445 return BPF_PROG_TYPE_SOCK_OPS; 4446 case BPF_CGROUP_DEVICE: 4447 return BPF_PROG_TYPE_CGROUP_DEVICE; 4448 case BPF_SK_MSG_VERDICT: 4449 return BPF_PROG_TYPE_SK_MSG; 4450 case BPF_SK_SKB_STREAM_PARSER: 4451 case BPF_SK_SKB_STREAM_VERDICT: 4452 case BPF_SK_SKB_VERDICT: 4453 return BPF_PROG_TYPE_SK_SKB; 4454 case BPF_LIRC_MODE2: 4455 return BPF_PROG_TYPE_LIRC_MODE2; 4456 case BPF_FLOW_DISSECTOR: 4457 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4458 case BPF_CGROUP_SYSCTL: 4459 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4460 case BPF_CGROUP_GETSOCKOPT: 4461 case BPF_CGROUP_SETSOCKOPT: 4462 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4463 case BPF_TRACE_ITER: 4464 case BPF_TRACE_RAW_TP: 4465 case BPF_TRACE_FENTRY: 4466 case BPF_TRACE_FEXIT: 4467 case BPF_TRACE_FSESSION: 4468 case BPF_TRACE_FSESSION_MULTI: 4469 case BPF_TRACE_FENTRY_MULTI: 4470 case BPF_TRACE_FEXIT_MULTI: 4471 case BPF_MODIFY_RETURN: 4472 return BPF_PROG_TYPE_TRACING; 4473 case BPF_LSM_MAC: 4474 return BPF_PROG_TYPE_LSM; 4475 case BPF_SK_LOOKUP: 4476 return BPF_PROG_TYPE_SK_LOOKUP; 4477 case BPF_XDP: 4478 return BPF_PROG_TYPE_XDP; 4479 case BPF_LSM_CGROUP: 4480 return BPF_PROG_TYPE_LSM; 4481 case BPF_TCX_INGRESS: 4482 case BPF_TCX_EGRESS: 4483 case BPF_NETKIT_PRIMARY: 4484 case BPF_NETKIT_PEER: 4485 return BPF_PROG_TYPE_SCHED_CLS; 4486 default: 4487 return BPF_PROG_TYPE_UNSPEC; 4488 } 4489 } 4490 4491 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4492 enum bpf_attach_type attach_type) 4493 { 4494 enum bpf_prog_type ptype; 4495 4496 switch (prog->type) { 4497 case BPF_PROG_TYPE_CGROUP_SOCK: 4498 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4499 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4500 case BPF_PROG_TYPE_SK_LOOKUP: 4501 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4502 case BPF_PROG_TYPE_CGROUP_SKB: 4503 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4504 /* cg-skb progs can be loaded by unpriv user. 4505 * check permissions at attach time. 4506 */ 4507 return -EPERM; 4508 4509 ptype = attach_type_to_prog_type(attach_type); 4510 if (prog->type != ptype) 4511 return -EINVAL; 4512 4513 return prog->enforce_expected_attach_type && 4514 prog->expected_attach_type != attach_type ? 4515 -EINVAL : 0; 4516 case BPF_PROG_TYPE_EXT: 4517 return 0; 4518 case BPF_PROG_TYPE_NETFILTER: 4519 if (attach_type != BPF_NETFILTER) 4520 return -EINVAL; 4521 return 0; 4522 case BPF_PROG_TYPE_PERF_EVENT: 4523 case BPF_PROG_TYPE_TRACEPOINT: 4524 if (attach_type != BPF_PERF_EVENT) 4525 return -EINVAL; 4526 return 0; 4527 case BPF_PROG_TYPE_KPROBE: 4528 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4529 attach_type != BPF_TRACE_KPROBE_MULTI) 4530 return -EINVAL; 4531 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4532 attach_type != BPF_TRACE_KPROBE_SESSION) 4533 return -EINVAL; 4534 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4535 attach_type != BPF_TRACE_UPROBE_MULTI) 4536 return -EINVAL; 4537 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4538 attach_type != BPF_TRACE_UPROBE_SESSION) 4539 return -EINVAL; 4540 if (attach_type != BPF_PERF_EVENT && 4541 attach_type != BPF_TRACE_KPROBE_MULTI && 4542 attach_type != BPF_TRACE_KPROBE_SESSION && 4543 attach_type != BPF_TRACE_UPROBE_MULTI && 4544 attach_type != BPF_TRACE_UPROBE_SESSION) 4545 return -EINVAL; 4546 return 0; 4547 case BPF_PROG_TYPE_SCHED_CLS: 4548 if (attach_type != BPF_TCX_INGRESS && 4549 attach_type != BPF_TCX_EGRESS && 4550 attach_type != BPF_NETKIT_PRIMARY && 4551 attach_type != BPF_NETKIT_PEER) 4552 return -EINVAL; 4553 return 0; 4554 default: 4555 ptype = attach_type_to_prog_type(attach_type); 4556 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4557 return -EINVAL; 4558 return 0; 4559 } 4560 } 4561 4562 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, 4563 bool check_atype) 4564 { 4565 switch (ptype) { 4566 case BPF_PROG_TYPE_CGROUP_DEVICE: 4567 case BPF_PROG_TYPE_CGROUP_SKB: 4568 case BPF_PROG_TYPE_CGROUP_SOCK: 4569 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4570 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4571 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4572 case BPF_PROG_TYPE_SOCK_OPS: 4573 return true; 4574 case BPF_PROG_TYPE_LSM: 4575 return check_atype ? atype == BPF_LSM_CGROUP : true; 4576 default: 4577 return false; 4578 } 4579 } 4580 4581 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4582 4583 #define BPF_F_ATTACH_MASK_BASE \ 4584 (BPF_F_ALLOW_OVERRIDE | \ 4585 BPF_F_ALLOW_MULTI | \ 4586 BPF_F_REPLACE | \ 4587 BPF_F_PREORDER) 4588 4589 #define BPF_F_ATTACH_MASK_MPROG \ 4590 (BPF_F_REPLACE | \ 4591 BPF_F_BEFORE | \ 4592 BPF_F_AFTER | \ 4593 BPF_F_ID | \ 4594 BPF_F_LINK) 4595 4596 static int bpf_prog_attach(const union bpf_attr *attr) 4597 { 4598 enum bpf_prog_type ptype; 4599 struct bpf_prog *prog; 4600 int ret; 4601 4602 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4603 return -EINVAL; 4604 4605 ptype = attach_type_to_prog_type(attr->attach_type); 4606 if (ptype == BPF_PROG_TYPE_UNSPEC) 4607 return -EINVAL; 4608 if (bpf_mprog_supported(ptype)) { 4609 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4610 return -EINVAL; 4611 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4612 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) 4613 return -EINVAL; 4614 } else { 4615 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4616 return -EINVAL; 4617 if (attr->relative_fd || 4618 attr->expected_revision) 4619 return -EINVAL; 4620 } 4621 4622 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4623 if (IS_ERR(prog)) 4624 return PTR_ERR(prog); 4625 4626 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4627 bpf_prog_put(prog); 4628 return -EINVAL; 4629 } 4630 4631 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { 4632 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4633 goto out; 4634 } 4635 4636 switch (ptype) { 4637 case BPF_PROG_TYPE_SK_SKB: 4638 case BPF_PROG_TYPE_SK_MSG: 4639 ret = sock_map_get_from_fd(attr, prog); 4640 break; 4641 case BPF_PROG_TYPE_LIRC_MODE2: 4642 ret = lirc_prog_attach(attr, prog); 4643 break; 4644 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4645 ret = netns_bpf_prog_attach(attr, prog); 4646 break; 4647 case BPF_PROG_TYPE_SCHED_CLS: 4648 if (attr->attach_type == BPF_TCX_INGRESS || 4649 attr->attach_type == BPF_TCX_EGRESS) 4650 ret = tcx_prog_attach(attr, prog); 4651 else 4652 ret = netkit_prog_attach(attr, prog); 4653 break; 4654 default: 4655 ret = -EINVAL; 4656 } 4657 out: 4658 if (ret) 4659 bpf_prog_put(prog); 4660 return ret; 4661 } 4662 4663 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4664 4665 static int bpf_prog_detach(const union bpf_attr *attr) 4666 { 4667 struct bpf_prog *prog = NULL; 4668 enum bpf_prog_type ptype; 4669 int ret; 4670 4671 if (CHECK_ATTR(BPF_PROG_DETACH)) 4672 return -EINVAL; 4673 4674 ptype = attach_type_to_prog_type(attr->attach_type); 4675 if (bpf_mprog_supported(ptype)) { 4676 if (ptype == BPF_PROG_TYPE_UNSPEC) 4677 return -EINVAL; 4678 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4679 return -EINVAL; 4680 if (attr->attach_bpf_fd) { 4681 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4682 if (IS_ERR(prog)) 4683 return PTR_ERR(prog); 4684 } else if (!bpf_mprog_detach_empty(ptype)) { 4685 return -EPERM; 4686 } 4687 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4688 if (attr->attach_flags || attr->relative_fd) 4689 return -EINVAL; 4690 } else if (attr->attach_flags || 4691 attr->relative_fd || 4692 attr->expected_revision) { 4693 return -EINVAL; 4694 } 4695 4696 switch (ptype) { 4697 case BPF_PROG_TYPE_SK_MSG: 4698 case BPF_PROG_TYPE_SK_SKB: 4699 ret = sock_map_prog_detach(attr, ptype); 4700 break; 4701 case BPF_PROG_TYPE_LIRC_MODE2: 4702 ret = lirc_prog_detach(attr); 4703 break; 4704 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4705 ret = netns_bpf_prog_detach(attr, ptype); 4706 break; 4707 case BPF_PROG_TYPE_CGROUP_DEVICE: 4708 case BPF_PROG_TYPE_CGROUP_SKB: 4709 case BPF_PROG_TYPE_CGROUP_SOCK: 4710 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4711 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4712 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4713 case BPF_PROG_TYPE_SOCK_OPS: 4714 case BPF_PROG_TYPE_LSM: 4715 ret = cgroup_bpf_prog_detach(attr, ptype); 4716 break; 4717 case BPF_PROG_TYPE_SCHED_CLS: 4718 if (attr->attach_type == BPF_TCX_INGRESS || 4719 attr->attach_type == BPF_TCX_EGRESS) 4720 ret = tcx_prog_detach(attr, prog); 4721 else 4722 ret = netkit_prog_detach(attr, prog); 4723 break; 4724 default: 4725 ret = -EINVAL; 4726 } 4727 4728 if (prog) 4729 bpf_prog_put(prog); 4730 return ret; 4731 } 4732 4733 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4734 4735 static int bpf_prog_query(const union bpf_attr *attr, 4736 union bpf_attr __user *uattr, u32 uattr_size) 4737 { 4738 if (!bpf_net_capable()) 4739 return -EPERM; 4740 if (CHECK_ATTR(BPF_PROG_QUERY)) 4741 return -EINVAL; 4742 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4743 return -EINVAL; 4744 4745 switch (attr->query.attach_type) { 4746 case BPF_CGROUP_INET_INGRESS: 4747 case BPF_CGROUP_INET_EGRESS: 4748 case BPF_CGROUP_INET_SOCK_CREATE: 4749 case BPF_CGROUP_INET_SOCK_RELEASE: 4750 case BPF_CGROUP_INET4_BIND: 4751 case BPF_CGROUP_INET6_BIND: 4752 case BPF_CGROUP_INET4_POST_BIND: 4753 case BPF_CGROUP_INET6_POST_BIND: 4754 case BPF_CGROUP_INET4_CONNECT: 4755 case BPF_CGROUP_INET6_CONNECT: 4756 case BPF_CGROUP_UNIX_CONNECT: 4757 case BPF_CGROUP_INET4_GETPEERNAME: 4758 case BPF_CGROUP_INET6_GETPEERNAME: 4759 case BPF_CGROUP_UNIX_GETPEERNAME: 4760 case BPF_CGROUP_INET4_GETSOCKNAME: 4761 case BPF_CGROUP_INET6_GETSOCKNAME: 4762 case BPF_CGROUP_UNIX_GETSOCKNAME: 4763 case BPF_CGROUP_UDP4_SENDMSG: 4764 case BPF_CGROUP_UDP6_SENDMSG: 4765 case BPF_CGROUP_UNIX_SENDMSG: 4766 case BPF_CGROUP_UDP4_RECVMSG: 4767 case BPF_CGROUP_UDP6_RECVMSG: 4768 case BPF_CGROUP_UNIX_RECVMSG: 4769 case BPF_CGROUP_SOCK_OPS: 4770 case BPF_CGROUP_DEVICE: 4771 case BPF_CGROUP_SYSCTL: 4772 case BPF_CGROUP_GETSOCKOPT: 4773 case BPF_CGROUP_SETSOCKOPT: 4774 case BPF_LSM_CGROUP: 4775 return cgroup_bpf_prog_query(attr, uattr, uattr_size); 4776 case BPF_LIRC_MODE2: 4777 return lirc_prog_query(attr, uattr); 4778 case BPF_FLOW_DISSECTOR: 4779 case BPF_SK_LOOKUP: 4780 return netns_bpf_prog_query(attr, uattr); 4781 case BPF_SK_SKB_STREAM_PARSER: 4782 case BPF_SK_SKB_STREAM_VERDICT: 4783 case BPF_SK_MSG_VERDICT: 4784 case BPF_SK_SKB_VERDICT: 4785 return sock_map_bpf_prog_query(attr, uattr); 4786 case BPF_TCX_INGRESS: 4787 case BPF_TCX_EGRESS: 4788 return tcx_prog_query(attr, uattr); 4789 case BPF_NETKIT_PRIMARY: 4790 case BPF_NETKIT_PEER: 4791 return netkit_prog_query(attr, uattr); 4792 default: 4793 return -EINVAL; 4794 } 4795 } 4796 4797 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4798 4799 static int bpf_prog_test_run(const union bpf_attr *attr, 4800 union bpf_attr __user *uattr) 4801 { 4802 struct bpf_prog *prog; 4803 int ret = -ENOTSUPP; 4804 4805 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4806 return -EINVAL; 4807 4808 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4809 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4810 return -EINVAL; 4811 4812 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4813 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4814 return -EINVAL; 4815 4816 prog = bpf_prog_get(attr->test.prog_fd); 4817 if (IS_ERR(prog)) 4818 return PTR_ERR(prog); 4819 4820 if (prog->aux->ops->test_run) 4821 ret = prog->aux->ops->test_run(prog, attr, uattr); 4822 4823 bpf_prog_put(prog); 4824 return ret; 4825 } 4826 4827 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4828 4829 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4830 union bpf_attr __user *uattr, 4831 struct idr *idr, 4832 spinlock_t *lock) 4833 { 4834 u32 next_id = attr->start_id; 4835 int err = 0; 4836 4837 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4838 return -EINVAL; 4839 4840 if (!capable(CAP_SYS_ADMIN)) 4841 return -EPERM; 4842 4843 next_id++; 4844 spin_lock_bh(lock); 4845 if (!idr_get_next(idr, &next_id)) 4846 err = -ENOENT; 4847 spin_unlock_bh(lock); 4848 4849 if (!err) 4850 err = put_user(next_id, &uattr->next_id); 4851 4852 return err; 4853 } 4854 4855 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4856 { 4857 struct bpf_map *map; 4858 4859 spin_lock_bh(&map_idr_lock); 4860 again: 4861 map = idr_get_next(&map_idr, id); 4862 if (map) { 4863 map = __bpf_map_inc_not_zero(map, false); 4864 if (IS_ERR(map)) { 4865 (*id)++; 4866 goto again; 4867 } 4868 } 4869 spin_unlock_bh(&map_idr_lock); 4870 4871 return map; 4872 } 4873 4874 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4875 { 4876 struct bpf_prog *prog; 4877 4878 spin_lock_bh(&prog_idr_lock); 4879 again: 4880 prog = idr_get_next(&prog_idr, id); 4881 if (prog) { 4882 prog = bpf_prog_inc_not_zero(prog); 4883 if (IS_ERR(prog)) { 4884 (*id)++; 4885 goto again; 4886 } 4887 } 4888 spin_unlock_bh(&prog_idr_lock); 4889 4890 return prog; 4891 } 4892 4893 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4894 4895 struct bpf_prog *bpf_prog_by_id(u32 id) 4896 { 4897 struct bpf_prog *prog; 4898 4899 if (!id) 4900 return ERR_PTR(-ENOENT); 4901 4902 spin_lock_bh(&prog_idr_lock); 4903 prog = idr_find(&prog_idr, id); 4904 if (prog) 4905 prog = bpf_prog_inc_not_zero(prog); 4906 else 4907 prog = ERR_PTR(-ENOENT); 4908 spin_unlock_bh(&prog_idr_lock); 4909 return prog; 4910 } 4911 4912 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4913 { 4914 struct bpf_prog *prog; 4915 u32 id = attr->prog_id; 4916 int fd; 4917 4918 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4919 return -EINVAL; 4920 4921 if (!capable(CAP_SYS_ADMIN)) 4922 return -EPERM; 4923 4924 prog = bpf_prog_by_id(id); 4925 if (IS_ERR(prog)) 4926 return PTR_ERR(prog); 4927 4928 fd = bpf_prog_new_fd(prog); 4929 if (fd < 0) 4930 bpf_prog_put(prog); 4931 4932 return fd; 4933 } 4934 4935 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4936 4937 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4938 { 4939 struct bpf_map *map; 4940 u32 id = attr->map_id; 4941 int f_flags; 4942 int fd; 4943 4944 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4945 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4946 return -EINVAL; 4947 4948 if (!capable(CAP_SYS_ADMIN)) 4949 return -EPERM; 4950 4951 f_flags = bpf_get_file_flag(attr->open_flags); 4952 if (f_flags < 0) 4953 return f_flags; 4954 4955 spin_lock_bh(&map_idr_lock); 4956 map = idr_find(&map_idr, id); 4957 if (map) 4958 map = __bpf_map_inc_not_zero(map, true); 4959 else 4960 map = ERR_PTR(-ENOENT); 4961 spin_unlock_bh(&map_idr_lock); 4962 4963 if (IS_ERR(map)) 4964 return PTR_ERR(map); 4965 4966 fd = bpf_map_new_fd(map, f_flags); 4967 if (fd < 0) 4968 bpf_map_put_with_uref(map); 4969 4970 return fd; 4971 } 4972 4973 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4974 unsigned long addr, u32 *off, 4975 u32 *type) 4976 { 4977 const struct bpf_map *map; 4978 int i; 4979 4980 mutex_lock(&prog->aux->used_maps_mutex); 4981 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4982 map = prog->aux->used_maps[i]; 4983 if (map == (void *)addr) { 4984 *type = BPF_PSEUDO_MAP_FD; 4985 goto out; 4986 } 4987 if (!map->ops->map_direct_value_meta) 4988 continue; 4989 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4990 *type = BPF_PSEUDO_MAP_VALUE; 4991 goto out; 4992 } 4993 } 4994 map = NULL; 4995 4996 out: 4997 mutex_unlock(&prog->aux->used_maps_mutex); 4998 return map; 4999 } 5000 5001 static void prepare_dump_pseudo_call(struct bpf_insn *insn) 5002 { 5003 s32 call_off = insn->imm; 5004 5005 /* 5006 * BPF_CALL_ARGS only exists for interpreter fallback. 5007 * 1. For interpreter (BPF_CALL_ARGS): insn->off is the index of 5008 * interpreters_args array, so here using bpf_call_args_imm() 5009 * to get the real address offset. 5010 * 2. For JIT (BPF_CALL): insn->off is the subprog id. 5011 */ 5012 if (insn->code == (BPF_JMP | BPF_CALL_ARGS)) 5013 insn->imm = bpf_call_args_imm(insn->off); 5014 else 5015 insn->imm = insn->off; 5016 5017 /* Avoid dumping a truncated and misleading pc-relative offset. */ 5018 if (call_off > S16_MAX || call_off < S16_MIN) 5019 insn->off = 0; 5020 else 5021 insn->off = call_off; 5022 } 5023 5024 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 5025 const struct cred *f_cred) 5026 { 5027 const struct bpf_map *map; 5028 struct bpf_insn *insns; 5029 u32 off, type; 5030 u64 imm; 5031 u8 code; 5032 int i; 5033 5034 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 5035 GFP_USER); 5036 if (!insns) 5037 return insns; 5038 5039 for (i = 0; i < prog->len; i++) { 5040 code = insns[i].code; 5041 5042 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 5043 insns[i].code = BPF_JMP | BPF_CALL; 5044 insns[i].imm = BPF_FUNC_tail_call; 5045 /* fall-through */ 5046 } 5047 if (code == (BPF_JMP | BPF_CALL) || 5048 code == (BPF_JMP | BPF_CALL_ARGS)) { 5049 /* Restore the legacy xlated dump layout. */ 5050 if (insns[i].src_reg == BPF_PSEUDO_CALL) 5051 prepare_dump_pseudo_call(&insns[i]); 5052 if (code == (BPF_JMP | BPF_CALL_ARGS)) 5053 insns[i].code = BPF_JMP | BPF_CALL; 5054 if (!bpf_dump_raw_ok(f_cred)) 5055 insns[i].imm = 0; 5056 continue; 5057 } 5058 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 5059 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 5060 continue; 5061 } 5062 5063 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 5064 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 5065 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 5066 continue; 5067 } 5068 5069 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 5070 continue; 5071 5072 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 5073 map = bpf_map_from_imm(prog, imm, &off, &type); 5074 if (map) { 5075 insns[i].src_reg = type; 5076 insns[i].imm = map->id; 5077 insns[i + 1].imm = off; 5078 continue; 5079 } 5080 } 5081 5082 return insns; 5083 } 5084 5085 static int set_info_rec_size(struct bpf_prog_info *info) 5086 { 5087 /* 5088 * Ensure info.*_rec_size is the same as kernel expected size 5089 * 5090 * or 5091 * 5092 * Only allow zero *_rec_size if both _rec_size and _cnt are 5093 * zero. In this case, the kernel will set the expected 5094 * _rec_size back to the info. 5095 */ 5096 5097 if ((info->nr_func_info || info->func_info_rec_size) && 5098 info->func_info_rec_size != sizeof(struct bpf_func_info)) 5099 return -EINVAL; 5100 5101 if ((info->nr_line_info || info->line_info_rec_size) && 5102 info->line_info_rec_size != sizeof(struct bpf_line_info)) 5103 return -EINVAL; 5104 5105 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 5106 info->jited_line_info_rec_size != sizeof(__u64)) 5107 return -EINVAL; 5108 5109 info->func_info_rec_size = sizeof(struct bpf_func_info); 5110 info->line_info_rec_size = sizeof(struct bpf_line_info); 5111 info->jited_line_info_rec_size = sizeof(__u64); 5112 5113 return 0; 5114 } 5115 5116 static int bpf_prog_get_info_by_fd(struct file *file, 5117 struct bpf_prog *prog, 5118 const union bpf_attr *attr, 5119 union bpf_attr __user *uattr) 5120 { 5121 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5122 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 5123 struct bpf_prog_info info; 5124 u32 info_len = attr->info.info_len; 5125 struct bpf_prog_kstats stats; 5126 char __user *uinsns; 5127 u32 ulen, len; 5128 int err; 5129 5130 len = offsetofend(struct bpf_prog_info, attach_btf_id); 5131 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len); 5132 if (err) 5133 return err; 5134 info_len = min_t(u32, sizeof(info), info_len); 5135 5136 memset(&info, 0, sizeof(info)); 5137 if (copy_from_user(&info, uinfo, info_len)) 5138 return -EFAULT; 5139 5140 info.type = prog->type; 5141 info.id = prog->aux->id; 5142 info.load_time = prog->aux->load_time; 5143 info.created_by_uid = from_kuid_munged(current_user_ns(), 5144 prog->aux->user->uid); 5145 info.gpl_compatible = prog->gpl_compatible; 5146 5147 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 5148 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 5149 5150 mutex_lock(&prog->aux->used_maps_mutex); 5151 ulen = info.nr_map_ids; 5152 info.nr_map_ids = prog->aux->used_map_cnt; 5153 ulen = min_t(u32, info.nr_map_ids, ulen); 5154 if (ulen) { 5155 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 5156 u32 i; 5157 5158 for (i = 0; i < ulen; i++) 5159 if (put_user(prog->aux->used_maps[i]->id, 5160 &user_map_ids[i])) { 5161 mutex_unlock(&prog->aux->used_maps_mutex); 5162 return -EFAULT; 5163 } 5164 } 5165 mutex_unlock(&prog->aux->used_maps_mutex); 5166 5167 err = set_info_rec_size(&info); 5168 if (err) 5169 return err; 5170 5171 bpf_prog_get_stats(prog, &stats); 5172 info.run_time_ns = stats.nsecs; 5173 info.run_cnt = stats.cnt; 5174 info.recursion_misses = stats.misses; 5175 5176 info.verified_insns = prog->aux->verified_insns; 5177 if (prog->aux->btf) 5178 info.btf_id = btf_obj_id(prog->aux->btf); 5179 5180 if (!bpf_capable()) { 5181 info.jited_prog_len = 0; 5182 info.xlated_prog_len = 0; 5183 info.nr_jited_ksyms = 0; 5184 info.nr_jited_func_lens = 0; 5185 info.nr_func_info = 0; 5186 info.nr_line_info = 0; 5187 info.nr_jited_line_info = 0; 5188 goto done; 5189 } 5190 5191 ulen = info.xlated_prog_len; 5192 info.xlated_prog_len = bpf_prog_insn_size(prog); 5193 if (info.xlated_prog_len && ulen) { 5194 struct bpf_insn *insns_sanitized; 5195 bool fault; 5196 5197 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) { 5198 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 5199 if (!insns_sanitized) 5200 return -ENOMEM; 5201 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 5202 ulen = min_t(u32, info.xlated_prog_len, ulen); 5203 fault = copy_to_user(uinsns, insns_sanitized, ulen); 5204 kfree(insns_sanitized); 5205 if (fault) 5206 return -EFAULT; 5207 } else { 5208 info.xlated_prog_insns = 0; 5209 } 5210 } 5211 5212 if (bpf_prog_is_offloaded(prog->aux)) { 5213 err = bpf_prog_offload_info_fill(&info, prog); 5214 if (err) 5215 return err; 5216 goto done; 5217 } 5218 5219 /* NOTE: the following code is supposed to be skipped for offload. 5220 * bpf_prog_offload_info_fill() is the place to fill similar fields 5221 * for offload. 5222 */ 5223 ulen = info.jited_prog_len; 5224 if (prog->aux->func_cnt) { 5225 u32 i; 5226 5227 info.jited_prog_len = 0; 5228 for (i = 0; i < prog->aux->func_cnt; i++) 5229 info.jited_prog_len += prog->aux->func[i]->jited_len; 5230 } else { 5231 info.jited_prog_len = prog->jited_len; 5232 } 5233 5234 if (info.jited_prog_len && ulen) { 5235 if (bpf_dump_raw_ok(file->f_cred)) { 5236 uinsns = u64_to_user_ptr(info.jited_prog_insns); 5237 ulen = min_t(u32, info.jited_prog_len, ulen); 5238 5239 /* for multi-function programs, copy the JITed 5240 * instructions for all the functions 5241 */ 5242 if (prog->aux->func_cnt) { 5243 u32 len, free, i; 5244 u8 *img; 5245 5246 free = ulen; 5247 for (i = 0; i < prog->aux->func_cnt; i++) { 5248 len = prog->aux->func[i]->jited_len; 5249 len = min_t(u32, len, free); 5250 img = (u8 *) prog->aux->func[i]->bpf_func; 5251 if (copy_to_user(uinsns, img, len)) 5252 return -EFAULT; 5253 uinsns += len; 5254 free -= len; 5255 if (!free) 5256 break; 5257 } 5258 } else { 5259 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 5260 return -EFAULT; 5261 } 5262 } else { 5263 info.jited_prog_insns = 0; 5264 } 5265 } 5266 5267 ulen = info.nr_jited_ksyms; 5268 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 5269 if (ulen) { 5270 if (bpf_dump_raw_ok(file->f_cred)) { 5271 unsigned long ksym_addr; 5272 u64 __user *user_ksyms; 5273 u32 i; 5274 5275 /* copy the address of the kernel symbol 5276 * corresponding to each function 5277 */ 5278 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 5279 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 5280 if (prog->aux->func_cnt) { 5281 for (i = 0; i < ulen; i++) { 5282 ksym_addr = (unsigned long) 5283 prog->aux->func[i]->bpf_func; 5284 if (put_user((u64) ksym_addr, 5285 &user_ksyms[i])) 5286 return -EFAULT; 5287 } 5288 } else { 5289 ksym_addr = (unsigned long) prog->bpf_func; 5290 if (put_user((u64) ksym_addr, &user_ksyms[0])) 5291 return -EFAULT; 5292 } 5293 } else { 5294 info.jited_ksyms = 0; 5295 } 5296 } 5297 5298 ulen = info.nr_jited_func_lens; 5299 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 5300 if (ulen) { 5301 if (bpf_dump_raw_ok(file->f_cred)) { 5302 u32 __user *user_lens; 5303 u32 func_len, i; 5304 5305 /* copy the JITed image lengths for each function */ 5306 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 5307 user_lens = u64_to_user_ptr(info.jited_func_lens); 5308 if (prog->aux->func_cnt) { 5309 for (i = 0; i < ulen; i++) { 5310 func_len = 5311 prog->aux->func[i]->jited_len; 5312 if (put_user(func_len, &user_lens[i])) 5313 return -EFAULT; 5314 } 5315 } else { 5316 func_len = prog->jited_len; 5317 if (put_user(func_len, &user_lens[0])) 5318 return -EFAULT; 5319 } 5320 } else { 5321 info.jited_func_lens = 0; 5322 } 5323 } 5324 5325 info.attach_btf_id = prog->aux->attach_btf_id; 5326 if (attach_btf) 5327 info.attach_btf_obj_id = btf_obj_id(attach_btf); 5328 5329 ulen = info.nr_func_info; 5330 info.nr_func_info = prog->aux->func_info_cnt; 5331 if (info.nr_func_info && ulen) { 5332 char __user *user_finfo; 5333 5334 user_finfo = u64_to_user_ptr(info.func_info); 5335 ulen = min_t(u32, info.nr_func_info, ulen); 5336 if (copy_to_user(user_finfo, prog->aux->func_info, 5337 info.func_info_rec_size * ulen)) 5338 return -EFAULT; 5339 } 5340 5341 ulen = info.nr_line_info; 5342 info.nr_line_info = prog->aux->nr_linfo; 5343 if (info.nr_line_info && ulen) { 5344 __u8 __user *user_linfo; 5345 5346 user_linfo = u64_to_user_ptr(info.line_info); 5347 ulen = min_t(u32, info.nr_line_info, ulen); 5348 if (copy_to_user(user_linfo, prog->aux->linfo, 5349 info.line_info_rec_size * ulen)) 5350 return -EFAULT; 5351 } 5352 5353 ulen = info.nr_jited_line_info; 5354 if (prog->aux->jited_linfo) 5355 info.nr_jited_line_info = prog->aux->nr_linfo; 5356 else 5357 info.nr_jited_line_info = 0; 5358 if (info.nr_jited_line_info && ulen) { 5359 if (bpf_dump_raw_ok(file->f_cred)) { 5360 unsigned long line_addr; 5361 __u64 __user *user_linfo; 5362 u32 i; 5363 5364 user_linfo = u64_to_user_ptr(info.jited_line_info); 5365 ulen = min_t(u32, info.nr_jited_line_info, ulen); 5366 for (i = 0; i < ulen; i++) { 5367 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 5368 if (put_user((__u64)line_addr, &user_linfo[i])) 5369 return -EFAULT; 5370 } 5371 } else { 5372 info.jited_line_info = 0; 5373 } 5374 } 5375 5376 ulen = info.nr_prog_tags; 5377 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 5378 if (ulen) { 5379 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 5380 u32 i; 5381 5382 user_prog_tags = u64_to_user_ptr(info.prog_tags); 5383 ulen = min_t(u32, info.nr_prog_tags, ulen); 5384 if (prog->aux->func_cnt) { 5385 for (i = 0; i < ulen; i++) { 5386 if (copy_to_user(user_prog_tags[i], 5387 prog->aux->func[i]->tag, 5388 BPF_TAG_SIZE)) 5389 return -EFAULT; 5390 } 5391 } else { 5392 if (copy_to_user(user_prog_tags[0], 5393 prog->tag, BPF_TAG_SIZE)) 5394 return -EFAULT; 5395 } 5396 } 5397 5398 done: 5399 if (copy_to_user(uinfo, &info, info_len) || 5400 put_user(info_len, &uattr->info.info_len)) 5401 return -EFAULT; 5402 5403 return 0; 5404 } 5405 5406 static int bpf_map_get_info_by_fd(struct file *file, 5407 struct bpf_map *map, 5408 const union bpf_attr *attr, 5409 union bpf_attr __user *uattr) 5410 { 5411 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5412 struct bpf_map_info info; 5413 u32 info_len = attr->info.info_len, len; 5414 int err; 5415 5416 len = offsetofend(struct bpf_map_info, hash_size); 5417 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len); 5418 if (err) 5419 return err; 5420 info_len = min_t(u32, sizeof(info), info_len); 5421 5422 memset(&info, 0, sizeof(info)); 5423 if (copy_from_user(&info, uinfo, info_len)) 5424 return -EFAULT; 5425 5426 info.type = map->map_type; 5427 info.id = map->id; 5428 info.key_size = map->key_size; 5429 info.value_size = map->value_size; 5430 info.max_entries = map->max_entries; 5431 info.map_flags = map->map_flags; 5432 info.map_extra = map->map_extra; 5433 memcpy(info.name, map->name, sizeof(map->name)); 5434 5435 if (map->btf) { 5436 info.btf_id = btf_obj_id(map->btf); 5437 info.btf_key_type_id = map->btf_key_type_id; 5438 info.btf_value_type_id = map->btf_value_type_id; 5439 } 5440 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 5441 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 5442 bpf_map_struct_ops_info_fill(&info, map); 5443 5444 if (bpf_map_is_offloaded(map)) { 5445 err = bpf_map_offload_info_fill(&info, map); 5446 if (err) 5447 return err; 5448 } 5449 5450 if (info.hash) { 5451 char __user *uhash = u64_to_user_ptr(info.hash); 5452 5453 if (!map->ops->map_get_hash) 5454 return -EINVAL; 5455 if (info.hash_size != sizeof(map->sha)) 5456 return -EINVAL; 5457 if (!READ_ONCE(map->frozen)) 5458 return -EPERM; 5459 5460 err = map->ops->map_get_hash(map); 5461 if (err != 0) 5462 return err; 5463 5464 if (copy_to_user(uhash, map->sha, sizeof(map->sha)) != 0) 5465 return -EFAULT; 5466 } else if (info.hash_size) { 5467 return -EINVAL; 5468 } 5469 5470 if (copy_to_user(uinfo, &info, info_len) || 5471 put_user(info_len, &uattr->info.info_len)) 5472 return -EFAULT; 5473 5474 return 0; 5475 } 5476 5477 static int bpf_btf_get_info_by_fd(struct file *file, 5478 struct btf *btf, 5479 const union bpf_attr *attr, 5480 union bpf_attr __user *uattr) 5481 { 5482 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5483 u32 info_len = attr->info.info_len; 5484 int err; 5485 5486 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5487 if (err) 5488 return err; 5489 5490 return btf_get_info_by_fd(btf, attr, uattr); 5491 } 5492 5493 static int bpf_link_get_info_by_fd(struct file *file, 5494 struct bpf_link *link, 5495 const union bpf_attr *attr, 5496 union bpf_attr __user *uattr) 5497 { 5498 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5499 struct bpf_link_info info; 5500 const struct bpf_prog *prog; 5501 u32 info_len = attr->info.info_len; 5502 int err; 5503 5504 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5505 if (err) 5506 return err; 5507 info_len = min_t(u32, sizeof(info), info_len); 5508 5509 memset(&info, 0, sizeof(info)); 5510 if (copy_from_user(&info, uinfo, info_len)) 5511 return -EFAULT; 5512 5513 info.type = link->type; 5514 info.id = link->id; 5515 5516 rcu_read_lock(); 5517 prog = READ_ONCE(link->prog); 5518 if (prog) 5519 info.prog_id = prog->aux->id; 5520 rcu_read_unlock(); 5521 5522 if (link->ops->fill_link_info) { 5523 err = link->ops->fill_link_info(link, &info); 5524 if (err) 5525 return err; 5526 } 5527 5528 if (copy_to_user(uinfo, &info, info_len) || 5529 put_user(info_len, &uattr->info.info_len)) 5530 return -EFAULT; 5531 5532 return 0; 5533 } 5534 5535 static int token_get_info_by_fd(struct file *file, 5536 struct bpf_token *token, 5537 const union bpf_attr *attr, 5538 union bpf_attr __user *uattr) 5539 { 5540 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5541 u32 info_len = attr->info.info_len; 5542 int err; 5543 5544 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5545 if (err) 5546 return err; 5547 return bpf_token_get_info_by_fd(token, attr, uattr); 5548 } 5549 5550 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5551 5552 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5553 union bpf_attr __user *uattr) 5554 { 5555 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5556 return -EINVAL; 5557 5558 CLASS(fd, f)(attr->info.bpf_fd); 5559 if (fd_empty(f)) 5560 return -EBADFD; 5561 5562 if (fd_file(f)->f_op == &bpf_prog_fops) 5563 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5564 uattr); 5565 else if (fd_file(f)->f_op == &bpf_map_fops) 5566 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5567 uattr); 5568 else if (fd_file(f)->f_op == &btf_fops) 5569 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5570 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5571 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5572 attr, uattr); 5573 else if (fd_file(f)->f_op == &bpf_token_fops) 5574 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5575 attr, uattr); 5576 return -EINVAL; 5577 } 5578 5579 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5580 5581 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 5582 { 5583 struct bpf_token *token = NULL; 5584 5585 if (CHECK_ATTR(BPF_BTF_LOAD)) 5586 return -EINVAL; 5587 5588 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5589 return -EINVAL; 5590 5591 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5592 token = bpf_token_get_from_fd(attr->btf_token_fd); 5593 if (IS_ERR(token)) 5594 return PTR_ERR(token); 5595 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5596 bpf_token_put(token); 5597 token = NULL; 5598 } 5599 } 5600 5601 if (!bpf_token_capable(token, CAP_BPF)) { 5602 bpf_token_put(token); 5603 return -EPERM; 5604 } 5605 5606 bpf_token_put(token); 5607 5608 return btf_new_fd(attr, uattr, attr_log); 5609 } 5610 5611 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd 5612 5613 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5614 { 5615 struct bpf_token *token = NULL; 5616 5617 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5618 return -EINVAL; 5619 5620 if (attr->open_flags & ~BPF_F_TOKEN_FD) 5621 return -EINVAL; 5622 5623 if (attr->open_flags & BPF_F_TOKEN_FD) { 5624 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); 5625 if (IS_ERR(token)) 5626 return PTR_ERR(token); 5627 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { 5628 bpf_token_put(token); 5629 token = NULL; 5630 } 5631 } 5632 5633 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { 5634 bpf_token_put(token); 5635 return -EPERM; 5636 } 5637 5638 bpf_token_put(token); 5639 5640 return btf_get_fd_by_id(attr->btf_id); 5641 } 5642 5643 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5644 union bpf_attr __user *uattr, 5645 u32 prog_id, u32 fd_type, 5646 const char *buf, u64 probe_offset, 5647 u64 probe_addr) 5648 { 5649 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5650 u32 len = buf ? strlen(buf) : 0, input_len; 5651 int err = 0; 5652 5653 if (put_user(len, &uattr->task_fd_query.buf_len)) 5654 return -EFAULT; 5655 input_len = attr->task_fd_query.buf_len; 5656 if (input_len && ubuf) { 5657 if (!len) { 5658 /* nothing to copy, just make ubuf NULL terminated */ 5659 char zero = '\0'; 5660 5661 if (put_user(zero, ubuf)) 5662 return -EFAULT; 5663 } else { 5664 err = bpf_copy_to_user(ubuf, buf, input_len, len); 5665 if (err == -EFAULT) 5666 return err; 5667 } 5668 } 5669 5670 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5671 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5672 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5673 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5674 return -EFAULT; 5675 5676 return err; 5677 } 5678 5679 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5680 5681 static int bpf_task_fd_query(const union bpf_attr *attr, 5682 union bpf_attr __user *uattr) 5683 { 5684 pid_t pid = attr->task_fd_query.pid; 5685 u32 fd = attr->task_fd_query.fd; 5686 const struct perf_event *event; 5687 struct task_struct *task; 5688 struct file *file; 5689 int err; 5690 5691 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5692 return -EINVAL; 5693 5694 if (!capable(CAP_SYS_ADMIN)) 5695 return -EPERM; 5696 5697 if (attr->task_fd_query.flags != 0) 5698 return -EINVAL; 5699 5700 rcu_read_lock(); 5701 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5702 rcu_read_unlock(); 5703 if (!task) 5704 return -ENOENT; 5705 5706 err = 0; 5707 file = fget_task(task, fd); 5708 put_task_struct(task); 5709 if (!file) 5710 return -EBADF; 5711 5712 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5713 struct bpf_link *link = file->private_data; 5714 5715 if (link->ops == &bpf_raw_tp_link_lops) { 5716 struct bpf_raw_tp_link *raw_tp = 5717 container_of(link, struct bpf_raw_tp_link, link); 5718 struct bpf_raw_event_map *btp = raw_tp->btp; 5719 5720 err = bpf_task_fd_query_copy(attr, uattr, 5721 raw_tp->link.prog->aux->id, 5722 BPF_FD_TYPE_RAW_TRACEPOINT, 5723 btp->tp->name, 0, 0); 5724 goto put_file; 5725 } 5726 goto out_not_supp; 5727 } 5728 5729 event = perf_get_event(file); 5730 if (!IS_ERR(event)) { 5731 u64 probe_offset, probe_addr; 5732 u32 prog_id, fd_type; 5733 const char *buf; 5734 5735 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5736 &buf, &probe_offset, 5737 &probe_addr, NULL); 5738 if (!err) 5739 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5740 fd_type, buf, 5741 probe_offset, 5742 probe_addr); 5743 goto put_file; 5744 } 5745 5746 out_not_supp: 5747 err = -ENOTSUPP; 5748 put_file: 5749 fput(file); 5750 return err; 5751 } 5752 5753 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5754 5755 #define BPF_DO_BATCH(fn, ...) \ 5756 do { \ 5757 if (!fn) { \ 5758 err = -ENOTSUPP; \ 5759 goto err_put; \ 5760 } \ 5761 err = fn(__VA_ARGS__); \ 5762 } while (0) 5763 5764 static int bpf_map_do_batch(const union bpf_attr *attr, 5765 union bpf_attr __user *uattr, 5766 int cmd) 5767 { 5768 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5769 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5770 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5771 struct bpf_map *map; 5772 int err; 5773 5774 if (CHECK_ATTR(BPF_MAP_BATCH)) 5775 return -EINVAL; 5776 5777 CLASS(fd, f)(attr->batch.map_fd); 5778 5779 map = __bpf_map_get(f); 5780 if (IS_ERR(map)) 5781 return PTR_ERR(map); 5782 if (has_write) 5783 bpf_map_write_active_inc(map); 5784 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5785 err = -EPERM; 5786 goto err_put; 5787 } 5788 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5789 err = -EPERM; 5790 goto err_put; 5791 } 5792 5793 if (cmd == BPF_MAP_LOOKUP_BATCH) 5794 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5795 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5796 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5797 else if (cmd == BPF_MAP_UPDATE_BATCH) 5798 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5799 else 5800 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5801 err_put: 5802 if (has_write) { 5803 maybe_wait_bpf_programs(map); 5804 bpf_map_write_active_dec(map); 5805 } 5806 return err; 5807 } 5808 5809 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.path_fd 5810 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5811 { 5812 struct bpf_prog *prog; 5813 int ret; 5814 5815 if (CHECK_ATTR(BPF_LINK_CREATE)) 5816 return -EINVAL; 5817 5818 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5819 return bpf_struct_ops_link_create(attr); 5820 5821 prog = bpf_prog_get(attr->link_create.prog_fd); 5822 if (IS_ERR(prog)) 5823 return PTR_ERR(prog); 5824 5825 ret = bpf_prog_attach_check_attach_type(prog, 5826 attr->link_create.attach_type); 5827 if (ret) 5828 goto out; 5829 5830 switch (prog->type) { 5831 case BPF_PROG_TYPE_CGROUP_SKB: 5832 case BPF_PROG_TYPE_CGROUP_SOCK: 5833 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5834 case BPF_PROG_TYPE_SOCK_OPS: 5835 case BPF_PROG_TYPE_CGROUP_DEVICE: 5836 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5837 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5838 ret = cgroup_bpf_link_attach(attr, prog); 5839 break; 5840 case BPF_PROG_TYPE_EXT: 5841 ret = bpf_tracing_prog_attach(prog, 5842 attr->link_create.target_fd, 5843 attr->link_create.target_btf_id, 5844 attr->link_create.tracing.cookie, 5845 attr->link_create.attach_type); 5846 break; 5847 case BPF_PROG_TYPE_LSM: 5848 case BPF_PROG_TYPE_TRACING: 5849 if (attr->link_create.attach_type != prog->expected_attach_type) { 5850 ret = -EINVAL; 5851 goto out; 5852 } 5853 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5854 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, 5855 attr->link_create.attach_type); 5856 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5857 ret = bpf_iter_link_attach(attr, uattr, prog); 5858 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5859 ret = cgroup_bpf_link_attach(attr, prog); 5860 else if (is_tracing_multi(prog->expected_attach_type)) 5861 ret = bpf_tracing_multi_attach(prog, attr); 5862 else 5863 ret = bpf_tracing_prog_attach(prog, 5864 attr->link_create.target_fd, 5865 attr->link_create.target_btf_id, 5866 attr->link_create.tracing.cookie, 5867 attr->link_create.attach_type); 5868 break; 5869 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5870 case BPF_PROG_TYPE_SK_LOOKUP: 5871 ret = netns_bpf_link_create(attr, prog); 5872 break; 5873 case BPF_PROG_TYPE_SK_MSG: 5874 case BPF_PROG_TYPE_SK_SKB: 5875 ret = sock_map_link_create(attr, prog); 5876 break; 5877 #ifdef CONFIG_NET 5878 case BPF_PROG_TYPE_XDP: 5879 ret = bpf_xdp_link_attach(attr, prog); 5880 break; 5881 case BPF_PROG_TYPE_SCHED_CLS: 5882 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5883 attr->link_create.attach_type == BPF_TCX_EGRESS) 5884 ret = tcx_link_attach(attr, prog); 5885 else 5886 ret = netkit_link_attach(attr, prog); 5887 break; 5888 case BPF_PROG_TYPE_NETFILTER: 5889 ret = bpf_nf_link_attach(attr, prog); 5890 break; 5891 #endif 5892 case BPF_PROG_TYPE_PERF_EVENT: 5893 case BPF_PROG_TYPE_TRACEPOINT: 5894 ret = bpf_perf_link_attach(attr, prog); 5895 break; 5896 case BPF_PROG_TYPE_KPROBE: 5897 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5898 ret = bpf_perf_link_attach(attr, prog); 5899 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5900 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5901 ret = bpf_kprobe_multi_link_attach(attr, prog); 5902 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5903 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5904 ret = bpf_uprobe_multi_link_attach(attr, prog); 5905 break; 5906 default: 5907 ret = -EINVAL; 5908 } 5909 5910 out: 5911 if (ret < 0) 5912 bpf_prog_put(prog); 5913 return ret; 5914 } 5915 5916 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5917 { 5918 struct bpf_map *new_map, *old_map = NULL; 5919 int ret; 5920 5921 new_map = bpf_map_get(attr->link_update.new_map_fd); 5922 if (IS_ERR(new_map)) 5923 return PTR_ERR(new_map); 5924 5925 if (attr->link_update.flags & BPF_F_REPLACE) { 5926 old_map = bpf_map_get(attr->link_update.old_map_fd); 5927 if (IS_ERR(old_map)) { 5928 ret = PTR_ERR(old_map); 5929 goto out_put; 5930 } 5931 } else if (attr->link_update.old_map_fd) { 5932 ret = -EINVAL; 5933 goto out_put; 5934 } 5935 5936 ret = link->ops->update_map(link, new_map, old_map); 5937 5938 if (old_map) 5939 bpf_map_put(old_map); 5940 out_put: 5941 bpf_map_put(new_map); 5942 return ret; 5943 } 5944 5945 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5946 5947 static int link_update(union bpf_attr *attr) 5948 { 5949 struct bpf_prog *old_prog = NULL, *new_prog; 5950 struct bpf_link *link; 5951 u32 flags; 5952 int ret; 5953 5954 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5955 return -EINVAL; 5956 5957 flags = attr->link_update.flags; 5958 if (flags & ~BPF_F_REPLACE) 5959 return -EINVAL; 5960 5961 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5962 if (IS_ERR(link)) 5963 return PTR_ERR(link); 5964 5965 if (link->ops->update_map) { 5966 ret = link_update_map(link, attr); 5967 goto out_put_link; 5968 } 5969 5970 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5971 if (IS_ERR(new_prog)) { 5972 ret = PTR_ERR(new_prog); 5973 goto out_put_link; 5974 } 5975 5976 if (flags & BPF_F_REPLACE) { 5977 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5978 if (IS_ERR(old_prog)) { 5979 ret = PTR_ERR(old_prog); 5980 old_prog = NULL; 5981 goto out_put_progs; 5982 } 5983 } else if (attr->link_update.old_prog_fd) { 5984 ret = -EINVAL; 5985 goto out_put_progs; 5986 } 5987 5988 if (link->ops->update_prog) 5989 ret = link->ops->update_prog(link, new_prog, old_prog); 5990 else 5991 ret = -EINVAL; 5992 5993 out_put_progs: 5994 if (old_prog) 5995 bpf_prog_put(old_prog); 5996 if (ret) 5997 bpf_prog_put(new_prog); 5998 out_put_link: 5999 bpf_link_put_direct(link); 6000 return ret; 6001 } 6002 6003 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 6004 6005 static int link_detach(union bpf_attr *attr) 6006 { 6007 struct bpf_link *link; 6008 int ret; 6009 6010 if (CHECK_ATTR(BPF_LINK_DETACH)) 6011 return -EINVAL; 6012 6013 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 6014 if (IS_ERR(link)) 6015 return PTR_ERR(link); 6016 6017 if (link->ops->detach) 6018 ret = link->ops->detach(link); 6019 else 6020 ret = -EOPNOTSUPP; 6021 6022 bpf_link_put_direct(link); 6023 return ret; 6024 } 6025 6026 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 6027 { 6028 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 6029 } 6030 EXPORT_SYMBOL(bpf_link_inc_not_zero); 6031 6032 struct bpf_link *bpf_link_by_id(u32 id) 6033 { 6034 struct bpf_link *link; 6035 6036 if (!id) 6037 return ERR_PTR(-ENOENT); 6038 6039 spin_lock_bh(&link_idr_lock); 6040 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 6041 link = idr_find(&link_idr, id); 6042 if (link) { 6043 if (link->id) 6044 link = bpf_link_inc_not_zero(link); 6045 else 6046 link = ERR_PTR(-EAGAIN); 6047 } else { 6048 link = ERR_PTR(-ENOENT); 6049 } 6050 spin_unlock_bh(&link_idr_lock); 6051 return link; 6052 } 6053 6054 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 6055 { 6056 struct bpf_link *link; 6057 6058 spin_lock_bh(&link_idr_lock); 6059 again: 6060 link = idr_get_next(&link_idr, id); 6061 if (link) { 6062 if (link->id) 6063 link = bpf_link_inc_not_zero(link); 6064 else 6065 link = ERR_PTR(-EAGAIN); 6066 if (IS_ERR(link)) { 6067 (*id)++; 6068 goto again; 6069 } 6070 } 6071 spin_unlock_bh(&link_idr_lock); 6072 6073 return link; 6074 } 6075 6076 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 6077 6078 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 6079 { 6080 struct bpf_link *link; 6081 u32 id = attr->link_id; 6082 int fd; 6083 6084 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 6085 return -EINVAL; 6086 6087 if (!capable(CAP_SYS_ADMIN)) 6088 return -EPERM; 6089 6090 link = bpf_link_by_id(id); 6091 if (IS_ERR(link)) 6092 return PTR_ERR(link); 6093 6094 fd = bpf_link_new_fd(link); 6095 if (fd < 0) 6096 bpf_link_put_direct(link); 6097 6098 return fd; 6099 } 6100 6101 DEFINE_MUTEX(bpf_stats_enabled_mutex); 6102 6103 static int bpf_stats_release(struct inode *inode, struct file *file) 6104 { 6105 mutex_lock(&bpf_stats_enabled_mutex); 6106 static_key_slow_dec(&bpf_stats_enabled_key.key); 6107 mutex_unlock(&bpf_stats_enabled_mutex); 6108 return 0; 6109 } 6110 6111 static const struct file_operations bpf_stats_fops = { 6112 .release = bpf_stats_release, 6113 }; 6114 6115 static int bpf_enable_runtime_stats(void) 6116 { 6117 int fd; 6118 6119 mutex_lock(&bpf_stats_enabled_mutex); 6120 6121 /* Set a very high limit to avoid overflow */ 6122 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 6123 mutex_unlock(&bpf_stats_enabled_mutex); 6124 return -EBUSY; 6125 } 6126 6127 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 6128 if (fd >= 0) 6129 static_key_slow_inc(&bpf_stats_enabled_key.key); 6130 6131 mutex_unlock(&bpf_stats_enabled_mutex); 6132 return fd; 6133 } 6134 6135 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 6136 6137 static int bpf_enable_stats(union bpf_attr *attr) 6138 { 6139 6140 if (CHECK_ATTR(BPF_ENABLE_STATS)) 6141 return -EINVAL; 6142 6143 if (!capable(CAP_SYS_ADMIN)) 6144 return -EPERM; 6145 6146 switch (attr->enable_stats.type) { 6147 case BPF_STATS_RUN_TIME: 6148 return bpf_enable_runtime_stats(); 6149 default: 6150 break; 6151 } 6152 return -EINVAL; 6153 } 6154 6155 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 6156 6157 static int bpf_iter_create(union bpf_attr *attr) 6158 { 6159 struct bpf_link *link; 6160 int err; 6161 6162 if (CHECK_ATTR(BPF_ITER_CREATE)) 6163 return -EINVAL; 6164 6165 if (attr->iter_create.flags) 6166 return -EINVAL; 6167 6168 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 6169 if (IS_ERR(link)) 6170 return PTR_ERR(link); 6171 6172 err = bpf_iter_new_fd(link); 6173 bpf_link_put_direct(link); 6174 6175 return err; 6176 } 6177 6178 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 6179 6180 static int bpf_prog_bind_map(union bpf_attr *attr) 6181 { 6182 struct bpf_prog *prog; 6183 struct bpf_map *map; 6184 struct bpf_map **used_maps_old, **used_maps_new; 6185 int i, ret = 0; 6186 6187 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 6188 return -EINVAL; 6189 6190 if (attr->prog_bind_map.flags) 6191 return -EINVAL; 6192 6193 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 6194 if (IS_ERR(prog)) 6195 return PTR_ERR(prog); 6196 6197 map = bpf_map_get(attr->prog_bind_map.map_fd); 6198 if (IS_ERR(map)) { 6199 ret = PTR_ERR(map); 6200 goto out_prog_put; 6201 } 6202 6203 mutex_lock(&prog->aux->used_maps_mutex); 6204 6205 used_maps_old = prog->aux->used_maps; 6206 6207 for (i = 0; i < prog->aux->used_map_cnt; i++) 6208 if (used_maps_old[i] == map) { 6209 bpf_map_put(map); 6210 goto out_unlock; 6211 } 6212 6213 used_maps_new = kmalloc_objs(used_maps_new[0], 6214 prog->aux->used_map_cnt + 1); 6215 if (!used_maps_new) { 6216 ret = -ENOMEM; 6217 goto out_unlock; 6218 } 6219 6220 /* The bpf program will not access the bpf map, but for the sake of 6221 * simplicity, increase sleepable_refcnt for sleepable program as well. 6222 */ 6223 if (prog->sleepable) 6224 atomic64_inc(&map->sleepable_refcnt); 6225 memcpy(used_maps_new, used_maps_old, 6226 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 6227 used_maps_new[prog->aux->used_map_cnt] = map; 6228 6229 prog->aux->used_map_cnt++; 6230 prog->aux->used_maps = used_maps_new; 6231 6232 kfree(used_maps_old); 6233 6234 out_unlock: 6235 mutex_unlock(&prog->aux->used_maps_mutex); 6236 6237 if (ret) 6238 bpf_map_put(map); 6239 out_prog_put: 6240 bpf_prog_put(prog); 6241 return ret; 6242 } 6243 6244 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 6245 6246 static int token_create(union bpf_attr *attr) 6247 { 6248 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 6249 return -EINVAL; 6250 6251 /* no flags are supported yet */ 6252 if (attr->token_create.flags) 6253 return -EINVAL; 6254 6255 return bpf_token_create(attr); 6256 } 6257 6258 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd 6259 6260 static int prog_stream_read(union bpf_attr *attr) 6261 { 6262 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); 6263 u32 len = attr->prog_stream_read.stream_buf_len; 6264 struct bpf_prog *prog; 6265 int ret; 6266 6267 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) 6268 return -EINVAL; 6269 6270 prog = bpf_prog_get(attr->prog_stream_read.prog_fd); 6271 if (IS_ERR(prog)) 6272 return PTR_ERR(prog); 6273 6274 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); 6275 bpf_prog_put(prog); 6276 6277 return ret; 6278 } 6279 6280 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.flags 6281 6282 static int prog_assoc_struct_ops(union bpf_attr *attr) 6283 { 6284 struct bpf_prog *prog; 6285 struct bpf_map *map; 6286 int ret; 6287 6288 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS)) 6289 return -EINVAL; 6290 6291 if (attr->prog_assoc_struct_ops.flags) 6292 return -EINVAL; 6293 6294 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd); 6295 if (IS_ERR(prog)) 6296 return PTR_ERR(prog); 6297 6298 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) { 6299 ret = -EINVAL; 6300 goto put_prog; 6301 } 6302 6303 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd); 6304 if (IS_ERR(map)) { 6305 ret = PTR_ERR(map); 6306 goto put_prog; 6307 } 6308 6309 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 6310 ret = -EINVAL; 6311 goto put_map; 6312 } 6313 6314 ret = bpf_prog_assoc_struct_ops(prog, map); 6315 6316 put_map: 6317 bpf_map_put(map); 6318 put_prog: 6319 bpf_prog_put(prog); 6320 return ret; 6321 } 6322 6323 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, 6324 bpfptr_t uattr_common, unsigned int size_common) 6325 { 6326 struct bpf_common_attr attr_common; 6327 u32 offsetof_log_true_size = 0; 6328 struct bpf_log_attr attr_log; 6329 union bpf_attr attr; 6330 int err; 6331 6332 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 6333 if (err) 6334 return err; 6335 size = min_t(u32, size, sizeof(attr)); 6336 6337 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 6338 memset(&attr, 0, sizeof(attr)); 6339 if (copy_from_bpfptr(&attr, uattr, size) != 0) 6340 return -EFAULT; 6341 6342 memset(&attr_common, 0, sizeof(attr_common)); 6343 if (cmd & BPF_COMMON_ATTRS) { 6344 err = bpf_check_uarg_tail_zero(uattr_common, 6345 offsetofend(struct bpf_common_attr, log_true_size), 6346 size_common); 6347 if (err) 6348 return err; 6349 6350 cmd &= ~BPF_COMMON_ATTRS; 6351 size_common = min_t(u32, size_common, sizeof(attr_common)); 6352 if (copy_from_bpfptr(&attr_common, uattr_common, size_common) != 0) 6353 return -EFAULT; 6354 } else { 6355 size_common = 0; 6356 } 6357 6358 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 6359 if (err < 0) 6360 return err; 6361 6362 switch (cmd) { 6363 case BPF_MAP_CREATE: 6364 err = map_create(&attr, uattr, &attr_common, uattr_common, size_common); 6365 break; 6366 case BPF_MAP_LOOKUP_ELEM: 6367 err = map_lookup_elem(&attr); 6368 break; 6369 case BPF_MAP_UPDATE_ELEM: 6370 err = map_update_elem(&attr, uattr); 6371 break; 6372 case BPF_MAP_DELETE_ELEM: 6373 err = map_delete_elem(&attr, uattr); 6374 break; 6375 case BPF_MAP_GET_NEXT_KEY: 6376 err = map_get_next_key(&attr); 6377 break; 6378 case BPF_MAP_FREEZE: 6379 err = map_freeze(&attr); 6380 break; 6381 case BPF_PROG_LOAD: 6382 if (size >= offsetofend(union bpf_attr, log_true_size)) 6383 offsetof_log_true_size = offsetof(union bpf_attr, log_true_size); 6384 err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level, 6385 offsetof_log_true_size, uattr, &attr_common, uattr_common, 6386 size_common); 6387 err = err ?: bpf_prog_load(&attr, uattr, &attr_log); 6388 break; 6389 case BPF_OBJ_PIN: 6390 err = bpf_obj_pin(&attr); 6391 break; 6392 case BPF_OBJ_GET: 6393 err = bpf_obj_get(&attr); 6394 break; 6395 case BPF_PROG_ATTACH: 6396 err = bpf_prog_attach(&attr); 6397 break; 6398 case BPF_PROG_DETACH: 6399 err = bpf_prog_detach(&attr); 6400 break; 6401 case BPF_PROG_QUERY: 6402 err = bpf_prog_query(&attr, uattr.user, size); 6403 break; 6404 case BPF_PROG_TEST_RUN: 6405 err = bpf_prog_test_run(&attr, uattr.user); 6406 break; 6407 case BPF_PROG_GET_NEXT_ID: 6408 err = bpf_obj_get_next_id(&attr, uattr.user, 6409 &prog_idr, &prog_idr_lock); 6410 break; 6411 case BPF_MAP_GET_NEXT_ID: 6412 err = bpf_obj_get_next_id(&attr, uattr.user, 6413 &map_idr, &map_idr_lock); 6414 break; 6415 case BPF_BTF_GET_NEXT_ID: 6416 err = bpf_obj_get_next_id(&attr, uattr.user, 6417 &btf_idr, &btf_idr_lock); 6418 break; 6419 case BPF_PROG_GET_FD_BY_ID: 6420 err = bpf_prog_get_fd_by_id(&attr); 6421 break; 6422 case BPF_MAP_GET_FD_BY_ID: 6423 err = bpf_map_get_fd_by_id(&attr); 6424 break; 6425 case BPF_OBJ_GET_INFO_BY_FD: 6426 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 6427 break; 6428 case BPF_RAW_TRACEPOINT_OPEN: 6429 err = bpf_raw_tracepoint_open(&attr); 6430 break; 6431 case BPF_BTF_LOAD: 6432 if (size >= offsetofend(union bpf_attr, btf_log_true_size)) 6433 offsetof_log_true_size = offsetof(union bpf_attr, btf_log_true_size); 6434 err = bpf_log_attr_init(&attr_log, attr.btf_log_buf, attr.btf_log_size, 6435 attr.btf_log_level, offsetof_log_true_size, uattr, 6436 &attr_common, uattr_common, size_common); 6437 err = err ?: bpf_btf_load(&attr, uattr, &attr_log); 6438 break; 6439 case BPF_BTF_GET_FD_BY_ID: 6440 err = bpf_btf_get_fd_by_id(&attr); 6441 break; 6442 case BPF_TASK_FD_QUERY: 6443 err = bpf_task_fd_query(&attr, uattr.user); 6444 break; 6445 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 6446 err = map_lookup_and_delete_elem(&attr); 6447 break; 6448 case BPF_MAP_LOOKUP_BATCH: 6449 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 6450 break; 6451 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 6452 err = bpf_map_do_batch(&attr, uattr.user, 6453 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 6454 break; 6455 case BPF_MAP_UPDATE_BATCH: 6456 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 6457 break; 6458 case BPF_MAP_DELETE_BATCH: 6459 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 6460 break; 6461 case BPF_LINK_CREATE: 6462 err = link_create(&attr, uattr); 6463 break; 6464 case BPF_LINK_UPDATE: 6465 err = link_update(&attr); 6466 break; 6467 case BPF_LINK_GET_FD_BY_ID: 6468 err = bpf_link_get_fd_by_id(&attr); 6469 break; 6470 case BPF_LINK_GET_NEXT_ID: 6471 err = bpf_obj_get_next_id(&attr, uattr.user, 6472 &link_idr, &link_idr_lock); 6473 break; 6474 case BPF_ENABLE_STATS: 6475 err = bpf_enable_stats(&attr); 6476 break; 6477 case BPF_ITER_CREATE: 6478 err = bpf_iter_create(&attr); 6479 break; 6480 case BPF_LINK_DETACH: 6481 err = link_detach(&attr); 6482 break; 6483 case BPF_PROG_BIND_MAP: 6484 err = bpf_prog_bind_map(&attr); 6485 break; 6486 case BPF_TOKEN_CREATE: 6487 err = token_create(&attr); 6488 break; 6489 case BPF_PROG_STREAM_READ_BY_FD: 6490 err = prog_stream_read(&attr); 6491 break; 6492 case BPF_PROG_ASSOC_STRUCT_OPS: 6493 err = prog_assoc_struct_ops(&attr); 6494 break; 6495 default: 6496 err = -EINVAL; 6497 break; 6498 } 6499 6500 return err; 6501 } 6502 6503 SYSCALL_DEFINE5(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size, 6504 struct bpf_common_attr __user *, uattr_common, unsigned int, size_common) 6505 { 6506 return __sys_bpf(cmd, USER_BPFPTR(uattr), size, USER_BPFPTR(uattr_common), size_common); 6507 } 6508 6509 static bool syscall_prog_is_valid_access(int off, int size, 6510 enum bpf_access_type type, 6511 const struct bpf_prog *prog, 6512 struct bpf_insn_access_aux *info) 6513 { 6514 if (off < 0 || off >= U16_MAX) 6515 return false; 6516 /* No alignment requirements for syscall ctx accesses. */ 6517 return true; 6518 } 6519 6520 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 6521 { 6522 switch (cmd) { 6523 case BPF_MAP_CREATE: 6524 case BPF_MAP_DELETE_ELEM: 6525 case BPF_MAP_UPDATE_ELEM: 6526 case BPF_MAP_FREEZE: 6527 case BPF_MAP_GET_FD_BY_ID: 6528 case BPF_PROG_LOAD: 6529 case BPF_BTF_LOAD: 6530 case BPF_LINK_CREATE: 6531 case BPF_RAW_TRACEPOINT_OPEN: 6532 break; 6533 default: 6534 return -EINVAL; 6535 } 6536 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size, KERNEL_BPFPTR(NULL), 0); 6537 } 6538 6539 /* To shut up -Wmissing-prototypes. 6540 * This function is used by the kernel light skeleton 6541 * to load bpf programs when modules are loaded or during kernel boot. 6542 * See tools/lib/bpf/skel_internal.h 6543 */ 6544 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 6545 6546 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 6547 { 6548 struct bpf_prog * __maybe_unused prog; 6549 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 6550 6551 switch (cmd) { 6552 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 6553 case BPF_PROG_TEST_RUN: 6554 if (attr->test.data_in || attr->test.data_out || 6555 attr->test.ctx_out || attr->test.duration || 6556 attr->test.repeat || attr->test.flags) 6557 return -EINVAL; 6558 6559 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 6560 if (IS_ERR(prog)) 6561 return PTR_ERR(prog); 6562 6563 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 6564 attr->test.ctx_size_in > U16_MAX) { 6565 bpf_prog_put(prog); 6566 return -EINVAL; 6567 } 6568 6569 run_ctx.bpf_cookie = 0; 6570 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 6571 /* recursion detected */ 6572 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 6573 bpf_prog_put(prog); 6574 return -EBUSY; 6575 } 6576 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 6577 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 6578 &run_ctx); 6579 bpf_prog_put(prog); 6580 return 0; 6581 #endif 6582 default: 6583 return ____bpf_sys_bpf(cmd, attr, size); 6584 } 6585 } 6586 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); 6587 6588 static const struct bpf_func_proto bpf_sys_bpf_proto = { 6589 .func = bpf_sys_bpf, 6590 .gpl_only = false, 6591 .might_sleep = true, 6592 .ret_type = RET_INTEGER, 6593 .arg1_type = ARG_ANYTHING, 6594 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6595 .arg3_type = ARG_MEM_SIZE, 6596 }; 6597 6598 const struct bpf_func_proto * __weak 6599 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6600 { 6601 return bpf_base_func_proto(func_id, prog); 6602 } 6603 6604 BPF_CALL_1(bpf_sys_close, u32, fd) 6605 { 6606 /* When bpf program calls this helper there should not be 6607 * an fdget() without matching completed fdput(). 6608 * This helper is allowed in the following callchain only: 6609 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6610 */ 6611 return close_fd(fd); 6612 } 6613 6614 static const struct bpf_func_proto bpf_sys_close_proto = { 6615 .func = bpf_sys_close, 6616 .gpl_only = false, 6617 .might_sleep = true, 6618 .ret_type = RET_INTEGER, 6619 .arg1_type = ARG_ANYTHING, 6620 }; 6621 6622 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6623 { 6624 *res = 0; 6625 if (flags) 6626 return -EINVAL; 6627 6628 if (name_sz <= 1 || name[name_sz - 1]) 6629 return -EINVAL; 6630 6631 if (!bpf_dump_raw_ok(current_cred())) 6632 return -EPERM; 6633 6634 *res = kallsyms_lookup_name(name); 6635 return *res ? 0 : -ENOENT; 6636 } 6637 6638 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6639 .func = bpf_kallsyms_lookup_name, 6640 .gpl_only = false, 6641 .ret_type = RET_INTEGER, 6642 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6643 .arg2_type = ARG_MEM_SIZE_OR_ZERO, 6644 .arg3_type = ARG_ANYTHING, 6645 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6646 .arg4_size = sizeof(u64), 6647 }; 6648 6649 static const struct bpf_func_proto * 6650 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6651 { 6652 switch (func_id) { 6653 case BPF_FUNC_sys_bpf: 6654 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6655 ? NULL : &bpf_sys_bpf_proto; 6656 case BPF_FUNC_btf_find_by_name_kind: 6657 return &bpf_btf_find_by_name_kind_proto; 6658 case BPF_FUNC_sys_close: 6659 return &bpf_sys_close_proto; 6660 case BPF_FUNC_kallsyms_lookup_name: 6661 return &bpf_kallsyms_lookup_name_proto; 6662 default: 6663 return tracing_prog_func_proto(func_id, prog); 6664 } 6665 } 6666 6667 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6668 .get_func_proto = syscall_prog_func_proto, 6669 .is_valid_access = syscall_prog_is_valid_access, 6670 }; 6671 6672 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6673 .test_run = bpf_prog_test_run_syscall, 6674 }; 6675 6676 #ifdef CONFIG_SYSCTL 6677 static int bpf_stats_handler(const struct ctl_table *table, int write, 6678 void *buffer, size_t *lenp, loff_t *ppos) 6679 { 6680 struct static_key *key = (struct static_key *)table->data; 6681 static int saved_val; 6682 int val, ret; 6683 struct ctl_table tmp = { 6684 .data = &val, 6685 .maxlen = sizeof(val), 6686 .mode = table->mode, 6687 .extra1 = SYSCTL_ZERO, 6688 .extra2 = SYSCTL_ONE, 6689 }; 6690 6691 if (write && !capable(CAP_SYS_ADMIN)) 6692 return -EPERM; 6693 6694 mutex_lock(&bpf_stats_enabled_mutex); 6695 val = saved_val; 6696 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6697 if (write && !ret && val != saved_val) { 6698 if (val) 6699 static_key_slow_inc(key); 6700 else 6701 static_key_slow_dec(key); 6702 saved_val = val; 6703 } 6704 mutex_unlock(&bpf_stats_enabled_mutex); 6705 return ret; 6706 } 6707 6708 void __weak unpriv_ebpf_notify(int new_state) 6709 { 6710 } 6711 6712 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6713 void *buffer, size_t *lenp, loff_t *ppos) 6714 { 6715 int ret, unpriv_enable = *(int *)table->data; 6716 bool locked_state = unpriv_enable == 1; 6717 struct ctl_table tmp = *table; 6718 6719 if (write && !capable(CAP_SYS_ADMIN)) 6720 return -EPERM; 6721 6722 tmp.data = &unpriv_enable; 6723 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6724 if (write && !ret) { 6725 if (locked_state && unpriv_enable != 1) 6726 return -EPERM; 6727 *(int *)table->data = unpriv_enable; 6728 } 6729 6730 if (write) 6731 unpriv_ebpf_notify(unpriv_enable); 6732 6733 return ret; 6734 } 6735 6736 static const struct ctl_table bpf_syscall_table[] = { 6737 { 6738 .procname = "unprivileged_bpf_disabled", 6739 .data = &sysctl_unprivileged_bpf_disabled, 6740 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6741 .mode = 0644, 6742 .proc_handler = bpf_unpriv_handler, 6743 .extra1 = SYSCTL_ZERO, 6744 .extra2 = SYSCTL_TWO, 6745 }, 6746 { 6747 .procname = "bpf_stats_enabled", 6748 .data = &bpf_stats_enabled_key.key, 6749 .mode = 0644, 6750 .proc_handler = bpf_stats_handler, 6751 }, 6752 }; 6753 6754 static int __init bpf_syscall_sysctl_init(void) 6755 { 6756 register_sysctl_init("kernel", bpf_syscall_table); 6757 return 0; 6758 } 6759 late_initcall(bpf_syscall_sysctl_init); 6760 #endif /* CONFIG_SYSCTL */ 6761