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 struct page *bpf_alloc_page(int nid, bool sleepable) 606 { 607 if (!sleepable || !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 | __GFP_RETRY_MAYFAIL, 613 0); 614 } 615 616 void bpf_free_pages(struct llist_head *pages) 617 { 618 struct llist_node *node; 619 struct page *page, *tmp; 620 621 node = llist_del_all(pages); 622 llist_for_each_entry_safe(page, tmp, node, pcp_llist) 623 free_pages_nolock(page, 0); 624 } 625 626 int bpf_alloc_pages(int nid, unsigned long nr_pages, 627 struct llist_head *pages, bool sleepable) 628 { 629 unsigned long i; 630 struct page *pg; 631 632 for (i = 0; i < nr_pages; i++) { 633 pg = bpf_alloc_page(nid, sleepable); 634 if (!pg) 635 goto free_pages; 636 llist_add(&pg->pcp_llist, pages); 637 } 638 639 return 0; 640 641 free_pages: 642 bpf_free_pages(pages); 643 return -ENOMEM; 644 } 645 646 static int btf_field_cmp(const void *a, const void *b) 647 { 648 const struct btf_field *f1 = a, *f2 = b; 649 650 if (f1->offset < f2->offset) 651 return -1; 652 else if (f1->offset > f2->offset) 653 return 1; 654 return 0; 655 } 656 657 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 658 u32 field_mask) 659 { 660 struct btf_field *field; 661 662 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 663 return NULL; 664 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 665 if (!field || !(field->type & field_mask)) 666 return NULL; 667 return field; 668 } 669 670 void btf_record_free(struct btf_record *rec) 671 { 672 int i; 673 674 if (IS_ERR_OR_NULL(rec)) 675 return; 676 for (i = 0; i < rec->cnt; i++) { 677 switch (rec->fields[i].type) { 678 case BPF_KPTR_UNREF: 679 case BPF_KPTR_REF: 680 case BPF_KPTR_PERCPU: 681 case BPF_UPTR: 682 if (rec->fields[i].kptr.module) 683 module_put(rec->fields[i].kptr.module); 684 if (btf_is_kernel(rec->fields[i].kptr.btf)) 685 btf_put(rec->fields[i].kptr.btf); 686 break; 687 case BPF_LIST_HEAD: 688 case BPF_LIST_NODE: 689 case BPF_RB_ROOT: 690 case BPF_RB_NODE: 691 case BPF_SPIN_LOCK: 692 case BPF_RES_SPIN_LOCK: 693 case BPF_TIMER: 694 case BPF_REFCOUNT: 695 case BPF_WORKQUEUE: 696 case BPF_TASK_WORK: 697 case BPF_RCU_HEAD: 698 /* Nothing to release */ 699 break; 700 default: 701 WARN_ON_ONCE(1); 702 continue; 703 } 704 } 705 kfree(rec); 706 } 707 708 void bpf_map_free_record(struct bpf_map *map) 709 { 710 btf_record_free(map->record); 711 map->record = NULL; 712 } 713 714 struct btf_record *btf_record_dup(const struct btf_record *rec) 715 { 716 const struct btf_field *fields; 717 struct btf_record *new_rec; 718 int ret, size, i; 719 720 if (IS_ERR_OR_NULL(rec)) 721 return NULL; 722 size = struct_size(rec, fields, rec->cnt); 723 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 724 if (!new_rec) 725 return ERR_PTR(-ENOMEM); 726 /* Do a deep copy of the btf_record */ 727 fields = rec->fields; 728 new_rec->cnt = 0; 729 for (i = 0; i < rec->cnt; i++) { 730 switch (fields[i].type) { 731 case BPF_KPTR_UNREF: 732 case BPF_KPTR_REF: 733 case BPF_KPTR_PERCPU: 734 case BPF_UPTR: 735 if (btf_is_kernel(fields[i].kptr.btf)) 736 btf_get(fields[i].kptr.btf); 737 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 738 ret = -ENXIO; 739 goto free; 740 } 741 break; 742 case BPF_LIST_HEAD: 743 case BPF_LIST_NODE: 744 case BPF_RB_ROOT: 745 case BPF_RB_NODE: 746 case BPF_SPIN_LOCK: 747 case BPF_RES_SPIN_LOCK: 748 case BPF_TIMER: 749 case BPF_REFCOUNT: 750 case BPF_WORKQUEUE: 751 case BPF_TASK_WORK: 752 case BPF_RCU_HEAD: 753 /* Nothing to acquire */ 754 break; 755 default: 756 ret = -EFAULT; 757 WARN_ON_ONCE(1); 758 goto free; 759 } 760 new_rec->cnt++; 761 } 762 return new_rec; 763 free: 764 btf_record_free(new_rec); 765 return ERR_PTR(ret); 766 } 767 768 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 769 { 770 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 771 int size; 772 773 if (!a_has_fields && !b_has_fields) 774 return true; 775 if (a_has_fields != b_has_fields) 776 return false; 777 if (rec_a->cnt != rec_b->cnt) 778 return false; 779 size = struct_size(rec_a, fields, rec_a->cnt); 780 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 781 * members are zeroed out. So memcmp is safe to do without worrying 782 * about padding/unused fields. 783 * 784 * While spin_lock, timer, and kptr have no relation to map BTF, 785 * list_head metadata is specific to map BTF, the btf and value_rec 786 * members in particular. btf is the map BTF, while value_rec points to 787 * btf_record in that map BTF. 788 * 789 * So while by default, we don't rely on the map BTF (which the records 790 * were parsed from) matching for both records, which is not backwards 791 * compatible, in case list_head is part of it, we implicitly rely on 792 * that by way of depending on memcmp succeeding for it. 793 */ 794 return !memcmp(rec_a, rec_b, size); 795 } 796 797 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 798 { 799 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 800 return; 801 bpf_timer_cancel_and_free(obj + rec->timer_off); 802 } 803 804 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj) 805 { 806 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE))) 807 return; 808 bpf_wq_cancel_and_free(obj + rec->wq_off); 809 } 810 811 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj) 812 { 813 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK))) 814 return; 815 bpf_task_work_cancel_and_free(obj + rec->task_work_off); 816 } 817 818 void bpf_obj_cancel_fields(struct bpf_map *map, void *obj) 819 { 820 bpf_map_free_internal_structs(map, obj); 821 } 822 823 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 824 { 825 const struct btf_field *fields; 826 int i; 827 828 if (IS_ERR_OR_NULL(rec)) 829 return; 830 fields = rec->fields; 831 for (i = 0; i < rec->cnt; i++) { 832 struct btf_struct_meta *pointee_struct_meta; 833 const struct btf_field *field = &fields[i]; 834 void *field_ptr = obj + field->offset; 835 void *xchgd_field; 836 837 switch (fields[i].type) { 838 case BPF_SPIN_LOCK: 839 case BPF_RES_SPIN_LOCK: 840 break; 841 case BPF_TIMER: 842 bpf_timer_cancel_and_free(field_ptr); 843 break; 844 case BPF_WORKQUEUE: 845 bpf_wq_cancel_and_free(field_ptr); 846 break; 847 case BPF_TASK_WORK: 848 bpf_task_work_cancel_and_free(field_ptr); 849 break; 850 case BPF_KPTR_UNREF: 851 WRITE_ONCE(*(u64 *)field_ptr, 0); 852 break; 853 case BPF_KPTR_REF: 854 case BPF_KPTR_PERCPU: 855 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); 856 if (!xchgd_field) 857 break; 858 859 if (!btf_is_kernel(field->kptr.btf)) { 860 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, 861 field->kptr.btf_id); 862 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? 863 pointee_struct_meta->record : NULL, 864 fields[i].type == BPF_KPTR_PERCPU); 865 } else { 866 field->kptr.dtor(xchgd_field); 867 } 868 break; 869 case BPF_UPTR: 870 /* The caller ensured that no one is using the uptr */ 871 unpin_uptr_kaddr(*(void **)field_ptr); 872 break; 873 case BPF_LIST_HEAD: 874 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 875 continue; 876 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 877 break; 878 case BPF_RB_ROOT: 879 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 880 continue; 881 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); 882 break; 883 case BPF_LIST_NODE: 884 case BPF_RB_NODE: 885 case BPF_REFCOUNT: 886 case BPF_RCU_HEAD: 887 break; 888 default: 889 WARN_ON_ONCE(1); 890 continue; 891 } 892 } 893 } 894 895 static void bpf_map_free(struct bpf_map *map) 896 { 897 struct btf_record *rec = map->record; 898 struct btf *btf = map->btf; 899 900 /* implementation dependent freeing. Disabling migration to simplify 901 * the free of values or special fields allocated from bpf memory 902 * allocator. 903 */ 904 kfree(map->excl_prog_sha); 905 migrate_disable(); 906 map->ops->map_free(map); 907 migrate_enable(); 908 909 /* Delay freeing of btf_record for maps, as map_free 910 * callback usually needs access to them. It is better to do it here 911 * than require each callback to do the free itself manually. 912 * 913 * Note that the btf_record stashed in map->inner_map_meta->record was 914 * already freed using the map_free callback for map in map case which 915 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 916 * template bpf_map struct used during verification. 917 */ 918 btf_record_free(rec); 919 /* Delay freeing of btf for maps, as map_free callback may need 920 * struct_meta info which will be freed with btf_put(). 921 */ 922 btf_put(btf); 923 } 924 925 /* called from workqueue */ 926 static void bpf_map_free_deferred(struct work_struct *work) 927 { 928 struct bpf_map *map = container_of(work, struct bpf_map, work); 929 930 security_bpf_map_free(map); 931 bpf_map_release_memcg(map); 932 bpf_map_owner_free(map); 933 bpf_map_free(map); 934 } 935 936 static void bpf_map_put_uref(struct bpf_map *map) 937 { 938 if (atomic64_dec_and_test(&map->usercnt)) { 939 if (map->ops->map_release_uref) 940 map->ops->map_release_uref(map); 941 } 942 } 943 944 static void bpf_map_free_in_work(struct bpf_map *map) 945 { 946 INIT_WORK(&map->work, bpf_map_free_deferred); 947 /* Avoid spawning kworkers, since they all might contend 948 * for the same mutex like slab_mutex. 949 */ 950 queue_work(system_dfl_wq, &map->work); 951 } 952 953 static void bpf_map_free_rcu_gp(struct rcu_head *rcu) 954 { 955 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); 956 } 957 958 /* decrement map refcnt and schedule it for freeing via workqueue 959 * (underlying map implementation ops->map_free() might sleep) 960 */ 961 void bpf_map_put(struct bpf_map *map) 962 { 963 if (atomic64_dec_and_test(&map->refcnt)) { 964 /* bpf_map_free_id() must be called first */ 965 bpf_map_free_id(map); 966 967 if (map->ops->map_free_pre_rcu) 968 map->ops->map_free_pre_rcu(map); 969 970 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); 971 /* RCU tasks trace grace period implies RCU grace period. */ 972 if (READ_ONCE(map->free_after_mult_rcu_gp)) 973 call_rcu_tasks_trace(&map->rcu, bpf_map_free_rcu_gp); 974 else if (READ_ONCE(map->free_after_rcu_gp)) 975 call_rcu(&map->rcu, bpf_map_free_rcu_gp); 976 else 977 bpf_map_free_in_work(map); 978 } 979 } 980 EXPORT_SYMBOL_GPL(bpf_map_put); 981 982 void bpf_map_put_with_uref(struct bpf_map *map) 983 { 984 bpf_map_put_uref(map); 985 bpf_map_put(map); 986 } 987 988 static int bpf_map_release(struct inode *inode, struct file *filp) 989 { 990 struct bpf_map *map = filp->private_data; 991 992 if (map->ops->map_release) 993 map->ops->map_release(map, filp); 994 995 bpf_map_put_with_uref(map); 996 return 0; 997 } 998 999 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 1000 { 1001 fmode_t mode = fd_file(f)->f_mode; 1002 1003 /* Our file permissions may have been overridden by global 1004 * map permissions facing syscall side. 1005 */ 1006 if (READ_ONCE(map->frozen)) 1007 mode &= ~FMODE_CAN_WRITE; 1008 return mode; 1009 } 1010 1011 #ifdef CONFIG_PROC_FS 1012 /* Show the memory usage of a bpf map */ 1013 static u64 bpf_map_memory_usage(const struct bpf_map *map) 1014 { 1015 return map->ops->map_mem_usage(map); 1016 } 1017 1018 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 1019 { 1020 struct bpf_map *map = filp->private_data; 1021 u32 type = 0, jited = 0; 1022 1023 spin_lock(&map->owner_lock); 1024 if (map->owner) { 1025 type = map->owner->type; 1026 jited = map->owner->jited; 1027 } 1028 spin_unlock(&map->owner_lock); 1029 1030 seq_printf(m, 1031 "map_type:\t%u\n" 1032 "key_size:\t%u\n" 1033 "value_size:\t%u\n" 1034 "max_entries:\t%u\n" 1035 "map_flags:\t%#x\n" 1036 "map_extra:\t%#llx\n" 1037 "memlock:\t%llu\n" 1038 "map_id:\t%u\n" 1039 "frozen:\t%u\n", 1040 map->map_type, 1041 map->key_size, 1042 map->value_size, 1043 map->max_entries, 1044 map->map_flags, 1045 (unsigned long long)map->map_extra, 1046 bpf_map_memory_usage(map), 1047 map->id, 1048 READ_ONCE(map->frozen)); 1049 if (type) { 1050 seq_printf(m, "owner_prog_type:\t%u\n", type); 1051 seq_printf(m, "owner_jited:\t%u\n", jited); 1052 } 1053 } 1054 #endif 1055 1056 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 1057 loff_t *ppos) 1058 { 1059 /* We need this handler such that alloc_file() enables 1060 * f_mode with FMODE_CAN_READ. 1061 */ 1062 return -EINVAL; 1063 } 1064 1065 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 1066 size_t siz, loff_t *ppos) 1067 { 1068 /* We need this handler such that alloc_file() enables 1069 * f_mode with FMODE_CAN_WRITE. 1070 */ 1071 return -EINVAL; 1072 } 1073 1074 /* called for any extra memory-mapped regions (except initial) */ 1075 static void bpf_map_mmap_open(struct vm_area_struct *vma) 1076 { 1077 struct bpf_map *map = vma->vm_file->private_data; 1078 1079 if (vma->vm_flags & VM_MAYWRITE) 1080 bpf_map_write_active_inc(map); 1081 } 1082 1083 /* called for all unmapped memory region (including initial) */ 1084 static void bpf_map_mmap_close(struct vm_area_struct *vma) 1085 { 1086 struct bpf_map *map = vma->vm_file->private_data; 1087 1088 if (vma->vm_flags & VM_MAYWRITE) 1089 bpf_map_write_active_dec(map); 1090 } 1091 1092 static vm_fault_t bpf_map_mmap_fault(struct vm_fault *vmf) 1093 { 1094 struct bpf_map *map = vmf->vma->vm_private_data; 1095 1096 return map->ops->map_mmap_fault(map, vmf); 1097 } 1098 1099 static const struct vm_operations_struct bpf_map_default_vmops = { 1100 .open = bpf_map_mmap_open, 1101 .close = bpf_map_mmap_close, 1102 }; 1103 1104 static const struct vm_operations_struct bpf_map_lazy_vmops = { 1105 .open = bpf_map_mmap_open, 1106 .close = bpf_map_mmap_close, 1107 .fault = bpf_map_mmap_fault, 1108 }; 1109 1110 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 1111 { 1112 struct bpf_map *map = filp->private_data; 1113 int err = 0; 1114 1115 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 1116 return -ENOTSUPP; 1117 1118 if (!(vma->vm_flags & VM_SHARED)) 1119 return -EINVAL; 1120 1121 mutex_lock(&map->freeze_mutex); 1122 1123 if (vma->vm_flags & VM_WRITE) { 1124 if (map->frozen) { 1125 err = -EPERM; 1126 goto out; 1127 } 1128 /* map is meant to be read-only, so do not allow mapping as 1129 * writable, because it's possible to leak a writable page 1130 * reference and allows user-space to still modify it after 1131 * freezing, while verifier will assume contents do not change 1132 */ 1133 if (map->map_flags & BPF_F_RDONLY_PROG) { 1134 err = -EACCES; 1135 goto out; 1136 } 1137 bpf_map_write_active_inc(map); 1138 } 1139 out: 1140 mutex_unlock(&map->freeze_mutex); 1141 if (err) 1142 return err; 1143 1144 /* set default open/close callbacks */ 1145 vma->vm_ops = map->ops->map_mmap_fault ? &bpf_map_lazy_vmops : &bpf_map_default_vmops; 1146 vma->vm_private_data = map; 1147 vm_flags_clear(vma, VM_MAYEXEC); 1148 /* If mapping is read-only, then disallow potentially re-mapping with 1149 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing 1150 * means that as far as BPF map's memory-mapped VMAs are concerned, 1151 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set, 1152 * both should be set, so we can forget about VM_MAYWRITE and always 1153 * check just VM_WRITE 1154 */ 1155 if (!(vma->vm_flags & VM_WRITE)) 1156 vm_flags_clear(vma, VM_MAYWRITE); 1157 1158 err = map->ops->map_mmap(map, vma); 1159 if (err) { 1160 if (vma->vm_flags & VM_WRITE) 1161 bpf_map_write_active_dec(map); 1162 } 1163 1164 return err; 1165 } 1166 1167 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 1168 { 1169 struct bpf_map *map = filp->private_data; 1170 1171 if (map->ops->map_poll) 1172 return map->ops->map_poll(map, filp, pts); 1173 1174 return EPOLLERR; 1175 } 1176 1177 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr, 1178 unsigned long len, unsigned long pgoff, 1179 unsigned long flags) 1180 { 1181 struct bpf_map *map = filp->private_data; 1182 1183 if (map->ops->map_get_unmapped_area) 1184 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); 1185 #ifdef CONFIG_MMU 1186 return mm_get_unmapped_area(filp, addr, len, pgoff, flags); 1187 #else 1188 return addr; 1189 #endif 1190 } 1191 1192 const struct file_operations bpf_map_fops = { 1193 #ifdef CONFIG_PROC_FS 1194 .show_fdinfo = bpf_map_show_fdinfo, 1195 #endif 1196 .release = bpf_map_release, 1197 .read = bpf_dummy_read, 1198 .write = bpf_dummy_write, 1199 .mmap = bpf_map_mmap, 1200 .poll = bpf_map_poll, 1201 .get_unmapped_area = bpf_get_unmapped_area, 1202 }; 1203 1204 int bpf_map_new_fd(struct bpf_map *map, int flags) 1205 { 1206 int ret; 1207 1208 ret = security_bpf_map(map, OPEN_FMODE(flags)); 1209 if (ret < 0) 1210 return ret; 1211 1212 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 1213 flags | O_CLOEXEC); 1214 } 1215 1216 int bpf_get_file_flag(int flags) 1217 { 1218 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 1219 return -EINVAL; 1220 if (flags & BPF_F_RDONLY) 1221 return O_RDONLY; 1222 if (flags & BPF_F_WRONLY) 1223 return O_WRONLY; 1224 return O_RDWR; 1225 } 1226 1227 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 1228 #define CHECK_ATTR(CMD) \ 1229 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 1230 sizeof(attr->CMD##_LAST_FIELD), 0, \ 1231 sizeof(*attr) - \ 1232 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 1233 sizeof(attr->CMD##_LAST_FIELD)) != NULL 1234 1235 /* dst and src must have at least "size" number of bytes. 1236 * Return strlen on success and < 0 on error. 1237 */ 1238 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 1239 { 1240 const char *end = src + size; 1241 const char *orig_src = src; 1242 1243 memset(dst, 0, size); 1244 /* Copy all isalnum(), '_' and '.' chars. */ 1245 while (src < end && *src) { 1246 if (!isalnum(*src) && 1247 *src != '_' && *src != '.') 1248 return -EINVAL; 1249 *dst++ = *src++; 1250 } 1251 1252 /* No '\0' found in "size" number of bytes */ 1253 if (src == end) 1254 return -EINVAL; 1255 1256 return src - orig_src; 1257 } 1258 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy); 1259 1260 int map_check_no_btf(struct bpf_map *map, 1261 const struct btf *btf, 1262 const struct btf_type *key_type, 1263 const struct btf_type *value_type) 1264 { 1265 return -ENOTSUPP; 1266 } 1267 1268 static int map_check_btf(struct bpf_map *map, struct bpf_token *token, 1269 const struct btf *btf, u32 btf_key_id, u32 btf_value_id) 1270 { 1271 const struct btf_type *key_type, *value_type; 1272 u32 key_size, value_size; 1273 int ret = 0; 1274 1275 /* Some maps allow key to be unspecified. */ 1276 if (btf_key_id) { 1277 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 1278 if (!key_type || key_size != map->key_size) 1279 return -EINVAL; 1280 } else { 1281 key_type = btf_type_by_id(btf, 0); 1282 if (!map->ops->map_check_btf) 1283 return -EINVAL; 1284 } 1285 1286 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1287 if (!value_type || value_size != map->value_size) 1288 return -EINVAL; 1289 1290 map->record = btf_parse_fields(btf, value_type, 1291 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1292 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR | 1293 BPF_TASK_WORK | BPF_RCU_HEAD, 1294 map->value_size); 1295 if (!IS_ERR_OR_NULL(map->record)) { 1296 int i; 1297 1298 if (!bpf_token_capable(token, CAP_BPF)) { 1299 ret = -EPERM; 1300 goto free_map_tab; 1301 } 1302 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1303 ret = -EACCES; 1304 goto free_map_tab; 1305 } 1306 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1307 switch (map->record->field_mask & (1 << i)) { 1308 case 0: 1309 continue; 1310 case BPF_SPIN_LOCK: 1311 case BPF_RES_SPIN_LOCK: 1312 if (map->map_type != BPF_MAP_TYPE_HASH && 1313 map->map_type != BPF_MAP_TYPE_RHASH && 1314 map->map_type != BPF_MAP_TYPE_ARRAY && 1315 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1316 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1317 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1318 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1319 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1320 ret = -EOPNOTSUPP; 1321 goto free_map_tab; 1322 } 1323 break; 1324 case BPF_TIMER: 1325 case BPF_WORKQUEUE: 1326 case BPF_TASK_WORK: 1327 if (map->map_type != BPF_MAP_TYPE_HASH && 1328 map->map_type != BPF_MAP_TYPE_RHASH && 1329 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1330 map->map_type != BPF_MAP_TYPE_ARRAY) { 1331 ret = -EOPNOTSUPP; 1332 goto free_map_tab; 1333 } 1334 break; 1335 case BPF_RCU_HEAD: 1336 if (map->map_type != BPF_MAP_TYPE_ARRAY) { 1337 ret = -EOPNOTSUPP; 1338 goto free_map_tab; 1339 } 1340 break; 1341 case BPF_KPTR_UNREF: 1342 case BPF_KPTR_REF: 1343 case BPF_KPTR_PERCPU: 1344 case BPF_REFCOUNT: 1345 if (map->map_type != BPF_MAP_TYPE_HASH && 1346 map->map_type != BPF_MAP_TYPE_RHASH && 1347 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1348 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1349 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1350 map->map_type != BPF_MAP_TYPE_ARRAY && 1351 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1352 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1353 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1354 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1355 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1356 ret = -EOPNOTSUPP; 1357 goto free_map_tab; 1358 } 1359 break; 1360 case BPF_UPTR: 1361 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { 1362 ret = -EOPNOTSUPP; 1363 goto free_map_tab; 1364 } 1365 break; 1366 case BPF_LIST_HEAD: 1367 case BPF_RB_ROOT: 1368 if (map->map_type != BPF_MAP_TYPE_HASH && 1369 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1370 map->map_type != BPF_MAP_TYPE_ARRAY) { 1371 ret = -EOPNOTSUPP; 1372 goto free_map_tab; 1373 } 1374 break; 1375 default: 1376 /* Fail if map_type checks are missing for a field type */ 1377 ret = -EOPNOTSUPP; 1378 goto free_map_tab; 1379 } 1380 } 1381 } 1382 1383 ret = btf_check_and_fixup_fields(btf, map->record); 1384 if (ret < 0) 1385 goto free_map_tab; 1386 1387 if (map->ops->map_check_btf) { 1388 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1389 if (ret < 0) 1390 goto free_map_tab; 1391 } 1392 1393 return ret; 1394 free_map_tab: 1395 bpf_map_free_record(map); 1396 return ret; 1397 } 1398 1399 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size 1400 /* called via syscall */ 1401 static int map_create_alloc(union bpf_attr *attr, bpfptr_t uattr, struct bpf_verifier_log *log, 1402 struct bpf_map **mapp, struct bpf_token **tokenp) 1403 { 1404 const struct bpf_map_ops *ops; 1405 struct bpf_token *token = NULL; 1406 int numa_node = bpf_map_attr_numa_node(attr); 1407 u32 map_type = attr->map_type; 1408 struct bpf_map *map; 1409 bool token_flag; 1410 int err; 1411 1412 err = CHECK_ATTR(BPF_MAP_CREATE); 1413 if (err) { 1414 bpf_log(log, "Invalid attr.\n"); 1415 return -EINVAL; 1416 } 1417 1418 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it 1419 * to avoid per-map type checks tripping on unknown flag 1420 */ 1421 token_flag = attr->map_flags & BPF_F_TOKEN_FD; 1422 attr->map_flags &= ~BPF_F_TOKEN_FD; 1423 1424 if (attr->btf_vmlinux_value_type_id) { 1425 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 1426 bpf_log(log, "btf_vmlinux_value_type_id can only be used with struct_ops maps.\n"); 1427 return -EINVAL; 1428 } 1429 if (attr->btf_key_type_id || attr->btf_value_type_id) { 1430 bpf_log(log, "btf_vmlinux_value_type_id is mutually exclusive with btf_key_type_id and btf_value_type_id.\n"); 1431 return -EINVAL; 1432 } 1433 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1434 bpf_log(log, "Invalid btf_value_type_id.\n"); 1435 return -EINVAL; 1436 } 1437 1438 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1439 attr->map_type != BPF_MAP_TYPE_ARENA && 1440 attr->map_type != BPF_MAP_TYPE_RHASH && 1441 attr->map_extra != 0) { 1442 bpf_log(log, "Invalid map_extra.\n"); 1443 return -EINVAL; 1444 } 1445 1446 if (numa_node != NUMA_NO_NODE && 1447 ((unsigned int)numa_node >= nr_node_ids || 1448 !node_online(numa_node))) { 1449 bpf_log(log, "Invalid numa_node.\n"); 1450 return -EINVAL; 1451 } 1452 1453 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1454 map_type = attr->map_type; 1455 if (map_type >= ARRAY_SIZE(bpf_map_types)) { 1456 bpf_log(log, "Invalid map_type.\n"); 1457 return -EINVAL; 1458 } 1459 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1460 ops = bpf_map_types[map_type]; 1461 if (!ops) 1462 return -EINVAL; 1463 1464 if (ops->map_alloc_check) { 1465 err = ops->map_alloc_check(attr); 1466 if (err) 1467 return err; 1468 } 1469 if (attr->map_ifindex) 1470 ops = &bpf_map_offload_ops; 1471 if (!ops->map_mem_usage) 1472 return -EINVAL; 1473 1474 if (token_flag) { 1475 token = bpf_token_get_from_fd(attr->map_token_fd); 1476 if (IS_ERR(token)) { 1477 bpf_log(log, "Invalid map_token_fd.\n"); 1478 return PTR_ERR(token); 1479 } 1480 1481 /* if current token doesn't grant map creation permissions, 1482 * then we can't use this token, so ignore it and rely on 1483 * system-wide capabilities checks 1484 */ 1485 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || 1486 !bpf_token_allow_map_type(token, attr->map_type)) { 1487 bpf_token_put(token); 1488 token = NULL; 1489 } 1490 } 1491 1492 err = -EPERM; 1493 1494 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1495 * creation for unprivileged users; other actions depend 1496 * on fd availability and access to bpffs, so are dependent on 1497 * object creation success. Even with unprivileged BPF disabled, 1498 * capability checks are still carried out. 1499 */ 1500 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) 1501 goto put_token; 1502 1503 /* check privileged map type permissions */ 1504 switch (map_type) { 1505 case BPF_MAP_TYPE_ARRAY: 1506 case BPF_MAP_TYPE_PERCPU_ARRAY: 1507 case BPF_MAP_TYPE_PROG_ARRAY: 1508 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1509 case BPF_MAP_TYPE_CGROUP_ARRAY: 1510 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1511 case BPF_MAP_TYPE_HASH: 1512 case BPF_MAP_TYPE_RHASH: 1513 case BPF_MAP_TYPE_PERCPU_HASH: 1514 case BPF_MAP_TYPE_HASH_OF_MAPS: 1515 case BPF_MAP_TYPE_RINGBUF: 1516 case BPF_MAP_TYPE_USER_RINGBUF: 1517 case BPF_MAP_TYPE_CGROUP_STORAGE: 1518 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1519 /* unprivileged */ 1520 break; 1521 case BPF_MAP_TYPE_SK_STORAGE: 1522 case BPF_MAP_TYPE_INODE_STORAGE: 1523 case BPF_MAP_TYPE_TASK_STORAGE: 1524 case BPF_MAP_TYPE_CGRP_STORAGE: 1525 case BPF_MAP_TYPE_BLOOM_FILTER: 1526 case BPF_MAP_TYPE_LPM_TRIE: 1527 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1528 case BPF_MAP_TYPE_STACK_TRACE: 1529 case BPF_MAP_TYPE_QUEUE: 1530 case BPF_MAP_TYPE_STACK: 1531 case BPF_MAP_TYPE_LRU_HASH: 1532 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1533 case BPF_MAP_TYPE_STRUCT_OPS: 1534 case BPF_MAP_TYPE_CPUMAP: 1535 case BPF_MAP_TYPE_ARENA: 1536 case BPF_MAP_TYPE_INSN_ARRAY: 1537 if (!bpf_token_capable(token, CAP_BPF)) 1538 goto put_token; 1539 break; 1540 case BPF_MAP_TYPE_SOCKMAP: 1541 case BPF_MAP_TYPE_SOCKHASH: 1542 case BPF_MAP_TYPE_DEVMAP: 1543 case BPF_MAP_TYPE_DEVMAP_HASH: 1544 case BPF_MAP_TYPE_XSKMAP: 1545 if (!bpf_token_capable(token, CAP_NET_ADMIN)) 1546 goto put_token; 1547 break; 1548 default: 1549 WARN(1, "unsupported map type %d", map_type); 1550 goto put_token; 1551 } 1552 1553 map = ops->map_alloc(attr); 1554 if (IS_ERR(map)) { 1555 err = PTR_ERR(map); 1556 goto put_token; 1557 } 1558 map->ops = ops; 1559 map->map_type = map_type; 1560 1561 err = bpf_obj_name_cpy(map->name, attr->map_name, 1562 sizeof(attr->map_name)); 1563 if (err < 0) { 1564 bpf_log(log, "Invalid map_name.\n"); 1565 goto free_map; 1566 } 1567 1568 preempt_disable(); 1569 map->cookie = gen_cookie_next(&bpf_map_cookie); 1570 preempt_enable(); 1571 1572 atomic64_set(&map->refcnt, 1); 1573 atomic64_set(&map->usercnt, 1); 1574 mutex_init(&map->freeze_mutex); 1575 spin_lock_init(&map->owner_lock); 1576 1577 if (attr->btf_key_type_id || attr->btf_value_type_id || 1578 /* Even the map's value is a kernel's struct, 1579 * the bpf_prog.o must have BTF to begin with 1580 * to figure out the corresponding kernel's 1581 * counter part. Thus, attr->btf_fd has 1582 * to be valid also. 1583 */ 1584 attr->btf_vmlinux_value_type_id) { 1585 struct btf *btf; 1586 1587 btf = btf_get_by_fd(attr->btf_fd); 1588 if (IS_ERR(btf)) { 1589 bpf_log(log, "Invalid btf_fd.\n"); 1590 err = PTR_ERR(btf); 1591 goto free_map; 1592 } 1593 if (btf_is_kernel(btf)) { 1594 btf_put(btf); 1595 err = -EACCES; 1596 goto free_map; 1597 } 1598 map->btf = btf; 1599 1600 if (attr->btf_value_type_id) { 1601 err = map_check_btf(map, token, btf, attr->btf_key_type_id, 1602 attr->btf_value_type_id); 1603 if (err) 1604 goto free_map; 1605 } 1606 1607 map->btf_key_type_id = attr->btf_key_type_id; 1608 map->btf_value_type_id = attr->btf_value_type_id; 1609 map->btf_vmlinux_value_type_id = 1610 attr->btf_vmlinux_value_type_id; 1611 } 1612 1613 if (attr->excl_prog_hash) { 1614 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); 1615 1616 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { 1617 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1618 err = -EINVAL; 1619 goto free_map; 1620 } 1621 1622 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); 1623 if (!map->excl_prog_sha) { 1624 err = -ENOMEM; 1625 goto free_map; 1626 } 1627 1628 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) { 1629 err = -EFAULT; 1630 goto free_map; 1631 } 1632 } else if (attr->excl_prog_hash_size) { 1633 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1634 err = -EINVAL; 1635 goto free_map; 1636 } 1637 1638 *mapp = map; 1639 *tokenp = token; 1640 return 0; 1641 1642 free_map: 1643 bpf_map_free(map); 1644 put_token: 1645 bpf_token_put(token); 1646 return err; 1647 } 1648 1649 static int map_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common, 1650 bpfptr_t uattr_common, u32 size_common) 1651 { 1652 struct bpf_token *token = NULL; 1653 struct bpf_verifier_log *log; 1654 struct bpf_log_attr attr_log; 1655 struct bpf_map *map = NULL; 1656 int err, ret; 1657 int f_flags; 1658 1659 log = bpf_log_attr_create_vlog(&attr_log, attr_common, uattr_common, size_common); 1660 if (IS_ERR(log)) 1661 return PTR_ERR(log); 1662 1663 err = map_create_alloc(attr, uattr, log, &map, &token); 1664 1665 /* preserve original error even if log finalization is successful */ 1666 ret = bpf_log_attr_finalize(&attr_log, log); 1667 if (ret) 1668 err = ret; 1669 1670 kfree(log); 1671 1672 if (err) 1673 goto free_map; 1674 1675 f_flags = bpf_get_file_flag(attr->map_flags); 1676 if (f_flags < 0) { 1677 err = f_flags; 1678 goto free_map; 1679 } 1680 1681 err = security_bpf_map_create(map, attr, token, uattr.is_kernel); 1682 if (err) 1683 goto free_map; 1684 1685 err = bpf_map_alloc_id(map); 1686 if (err) 1687 goto free_map_sec; 1688 1689 bpf_map_save_memcg(map); 1690 bpf_token_put(token); 1691 1692 err = bpf_map_new_fd(map, f_flags); 1693 if (err < 0) { 1694 /* failed to allocate fd. 1695 * bpf_map_put_with_uref() is needed because the above 1696 * bpf_map_alloc_id() has published the map 1697 * to the userspace and the userspace may 1698 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1699 */ 1700 bpf_map_put_with_uref(map); 1701 return err; 1702 } 1703 1704 return err; 1705 1706 free_map_sec: 1707 security_bpf_map_free(map); 1708 free_map: 1709 if (map) 1710 bpf_map_free(map); 1711 bpf_token_put(token); 1712 return err; 1713 } 1714 1715 void bpf_map_inc(struct bpf_map *map) 1716 { 1717 atomic64_inc(&map->refcnt); 1718 } 1719 EXPORT_SYMBOL_GPL(bpf_map_inc); 1720 1721 void bpf_map_inc_with_uref(struct bpf_map *map) 1722 { 1723 atomic64_inc(&map->refcnt); 1724 atomic64_inc(&map->usercnt); 1725 } 1726 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1727 1728 struct bpf_map *bpf_map_get(u32 ufd) 1729 { 1730 CLASS(fd, f)(ufd); 1731 struct bpf_map *map = __bpf_map_get(f); 1732 1733 if (!IS_ERR(map)) 1734 bpf_map_inc(map); 1735 1736 return map; 1737 } 1738 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); 1739 1740 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1741 { 1742 CLASS(fd, f)(ufd); 1743 struct bpf_map *map = __bpf_map_get(f); 1744 1745 if (!IS_ERR(map)) 1746 bpf_map_inc_with_uref(map); 1747 1748 return map; 1749 } 1750 1751 /* map_idr_lock should have been held or the map should have been 1752 * protected by rcu read lock. 1753 */ 1754 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1755 { 1756 int refold; 1757 1758 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1759 if (!refold) 1760 return ERR_PTR(-ENOENT); 1761 if (uref) 1762 atomic64_inc(&map->usercnt); 1763 1764 return map; 1765 } 1766 1767 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1768 { 1769 lockdep_assert(rcu_read_lock_held()); 1770 return __bpf_map_inc_not_zero(map, false); 1771 } 1772 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1773 1774 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value, 1775 bool delete) 1776 { 1777 return -ENOTSUPP; 1778 } 1779 1780 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1781 { 1782 if (key_size) 1783 return vmemdup_user(ukey, key_size); 1784 1785 if (ukey) 1786 return ERR_PTR(-EINVAL); 1787 1788 return NULL; 1789 } 1790 1791 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1792 { 1793 if (key_size) 1794 return kvmemdup_bpfptr(ukey, key_size); 1795 1796 if (!bpfptr_is_null(ukey)) 1797 return ERR_PTR(-EINVAL); 1798 1799 return NULL; 1800 } 1801 1802 /* last field in 'union bpf_attr' used by this command */ 1803 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1804 1805 static int map_lookup_elem(union bpf_attr *attr) 1806 { 1807 void __user *ukey = u64_to_user_ptr(attr->key); 1808 void __user *uvalue = u64_to_user_ptr(attr->value); 1809 struct bpf_map *map; 1810 void *key, *value; 1811 u32 value_size; 1812 int err; 1813 1814 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1815 return -EINVAL; 1816 1817 CLASS(fd, f)(attr->map_fd); 1818 map = __bpf_map_get(f); 1819 if (IS_ERR(map)) 1820 return PTR_ERR(map); 1821 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1822 return -EPERM; 1823 1824 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU); 1825 if (err) 1826 return err; 1827 1828 key = __bpf_copy_key(ukey, map->key_size); 1829 if (IS_ERR(key)) 1830 return PTR_ERR(key); 1831 1832 value_size = bpf_map_value_size(map, attr->flags); 1833 1834 err = -ENOMEM; 1835 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1836 if (!value) 1837 goto free_key; 1838 1839 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1840 if (copy_from_user(value, uvalue, value_size)) 1841 err = -EFAULT; 1842 else 1843 err = bpf_map_copy_value(map, key, value, attr->flags); 1844 goto free_value; 1845 } 1846 1847 err = bpf_map_copy_value(map, key, value, attr->flags); 1848 if (err) 1849 goto free_value; 1850 1851 err = -EFAULT; 1852 if (copy_to_user(uvalue, value, value_size) != 0) 1853 goto free_value; 1854 1855 err = 0; 1856 1857 free_value: 1858 kvfree(value); 1859 free_key: 1860 kvfree(key); 1861 return err; 1862 } 1863 1864 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1865 1866 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1867 { 1868 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1869 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1870 struct bpf_map *map; 1871 void *key, *value; 1872 u32 value_size; 1873 int err; 1874 1875 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1876 return -EINVAL; 1877 1878 CLASS(fd, f)(attr->map_fd); 1879 map = __bpf_map_get(f); 1880 if (IS_ERR(map)) 1881 return PTR_ERR(map); 1882 bpf_map_write_active_inc(map); 1883 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1884 err = -EPERM; 1885 goto err_put; 1886 } 1887 1888 err = bpf_map_check_op_flags(map, attr->flags, ~0); 1889 if (err) 1890 goto err_put; 1891 1892 key = ___bpf_copy_key(ukey, map->key_size); 1893 if (IS_ERR(key)) { 1894 err = PTR_ERR(key); 1895 goto err_put; 1896 } 1897 1898 value_size = bpf_map_value_size(map, attr->flags); 1899 value = kvmemdup_bpfptr(uvalue, value_size); 1900 if (IS_ERR(value)) { 1901 err = PTR_ERR(value); 1902 goto free_key; 1903 } 1904 1905 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); 1906 if (!err) 1907 maybe_wait_bpf_programs(map); 1908 1909 kvfree(value); 1910 free_key: 1911 kvfree(key); 1912 err_put: 1913 bpf_map_write_active_dec(map); 1914 return err; 1915 } 1916 1917 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1918 1919 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1920 { 1921 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1922 struct bpf_map *map; 1923 void *key; 1924 int err; 1925 1926 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1927 return -EINVAL; 1928 1929 CLASS(fd, f)(attr->map_fd); 1930 map = __bpf_map_get(f); 1931 if (IS_ERR(map)) 1932 return PTR_ERR(map); 1933 bpf_map_write_active_inc(map); 1934 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1935 err = -EPERM; 1936 goto err_put; 1937 } 1938 1939 key = ___bpf_copy_key(ukey, map->key_size); 1940 if (IS_ERR(key)) { 1941 err = PTR_ERR(key); 1942 goto err_put; 1943 } 1944 1945 if (bpf_map_is_offloaded(map)) { 1946 err = bpf_map_offload_delete_elem(map, key); 1947 goto out; 1948 } else if (IS_FD_PROG_ARRAY(map) || 1949 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1950 /* These maps require sleepable context */ 1951 err = map->ops->map_delete_elem(map, key); 1952 goto out; 1953 } 1954 1955 bpf_disable_instrumentation(); 1956 rcu_read_lock(); 1957 err = map->ops->map_delete_elem(map, key); 1958 rcu_read_unlock(); 1959 bpf_enable_instrumentation(); 1960 if (!err) 1961 maybe_wait_bpf_programs(map); 1962 out: 1963 kvfree(key); 1964 err_put: 1965 bpf_map_write_active_dec(map); 1966 return err; 1967 } 1968 1969 /* last field in 'union bpf_attr' used by this command */ 1970 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1971 1972 static int map_get_next_key(union bpf_attr *attr) 1973 { 1974 void __user *ukey = u64_to_user_ptr(attr->key); 1975 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1976 struct bpf_map *map; 1977 void *key, *next_key; 1978 int err; 1979 1980 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1981 return -EINVAL; 1982 1983 CLASS(fd, f)(attr->map_fd); 1984 map = __bpf_map_get(f); 1985 if (IS_ERR(map)) 1986 return PTR_ERR(map); 1987 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1988 return -EPERM; 1989 1990 if (ukey) { 1991 key = __bpf_copy_key(ukey, map->key_size); 1992 if (IS_ERR(key)) 1993 return PTR_ERR(key); 1994 } else { 1995 key = NULL; 1996 } 1997 1998 err = -ENOMEM; 1999 next_key = kvmalloc(map->key_size, GFP_USER); 2000 if (!next_key) 2001 goto free_key; 2002 2003 if (bpf_map_is_offloaded(map)) { 2004 err = bpf_map_offload_get_next_key(map, key, next_key); 2005 goto out; 2006 } 2007 2008 rcu_read_lock(); 2009 err = map->ops->map_get_next_key(map, key, next_key); 2010 rcu_read_unlock(); 2011 out: 2012 if (err) 2013 goto free_next_key; 2014 2015 err = -EFAULT; 2016 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 2017 goto free_next_key; 2018 2019 err = 0; 2020 2021 free_next_key: 2022 kvfree(next_key); 2023 free_key: 2024 kvfree(key); 2025 return err; 2026 } 2027 2028 int generic_map_delete_batch(struct bpf_map *map, 2029 const union bpf_attr *attr, 2030 union bpf_attr __user *uattr) 2031 { 2032 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2033 u32 cp, max_count; 2034 int err = 0; 2035 void *key; 2036 2037 if (attr->batch.elem_flags & ~BPF_F_LOCK) 2038 return -EINVAL; 2039 2040 if ((attr->batch.elem_flags & BPF_F_LOCK) && 2041 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2042 return -EINVAL; 2043 } 2044 2045 max_count = attr->batch.count; 2046 if (!max_count) 2047 return 0; 2048 2049 if (put_user(0, &uattr->batch.count)) 2050 return -EFAULT; 2051 2052 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2053 if (!key) 2054 return -ENOMEM; 2055 2056 for (cp = 0; cp < max_count; cp++) { 2057 err = -EFAULT; 2058 if (copy_from_user(key, keys + (size_t)cp * map->key_size, 2059 map->key_size)) 2060 break; 2061 2062 if (bpf_map_is_offloaded(map)) { 2063 err = bpf_map_offload_delete_elem(map, key); 2064 break; 2065 } 2066 2067 bpf_disable_instrumentation(); 2068 rcu_read_lock(); 2069 err = map->ops->map_delete_elem(map, key); 2070 rcu_read_unlock(); 2071 bpf_enable_instrumentation(); 2072 if (err) 2073 break; 2074 cond_resched(); 2075 } 2076 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2077 err = -EFAULT; 2078 2079 kvfree(key); 2080 2081 return err; 2082 } 2083 2084 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 2085 const union bpf_attr *attr, 2086 union bpf_attr __user *uattr) 2087 { 2088 void __user *values = u64_to_user_ptr(attr->batch.values); 2089 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2090 u32 value_size, cp, max_count; 2091 void *key, *value; 2092 int err = 0; 2093 2094 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, 2095 BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS); 2096 if (err) 2097 return err; 2098 2099 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2100 2101 max_count = attr->batch.count; 2102 if (!max_count) 2103 return 0; 2104 2105 if (put_user(0, &uattr->batch.count)) 2106 return -EFAULT; 2107 2108 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2109 if (!key) 2110 return -ENOMEM; 2111 2112 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2113 if (!value) { 2114 kvfree(key); 2115 return -ENOMEM; 2116 } 2117 2118 for (cp = 0; cp < max_count; cp++) { 2119 err = -EFAULT; 2120 if (copy_from_user(key, keys + (size_t)cp * map->key_size, 2121 map->key_size) || 2122 copy_from_user(value, values + (size_t)cp * value_size, value_size)) 2123 break; 2124 2125 err = bpf_map_update_value(map, map_file, key, value, 2126 attr->batch.elem_flags); 2127 2128 if (err) 2129 break; 2130 cond_resched(); 2131 } 2132 2133 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2134 err = -EFAULT; 2135 2136 kvfree(value); 2137 kvfree(key); 2138 2139 return err; 2140 } 2141 2142 int generic_map_lookup_batch(struct bpf_map *map, 2143 const union bpf_attr *attr, 2144 union bpf_attr __user *uattr) 2145 { 2146 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 2147 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 2148 void __user *values = u64_to_user_ptr(attr->batch.values); 2149 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2150 void *buf, *buf_prevkey, *prev_key, *key, *value; 2151 u32 value_size, cp, max_count; 2152 int err; 2153 2154 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU); 2155 if (err) 2156 return err; 2157 2158 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2159 2160 max_count = attr->batch.count; 2161 if (!max_count) 2162 return 0; 2163 2164 if (put_user(0, &uattr->batch.count)) 2165 return -EFAULT; 2166 2167 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2168 if (!buf_prevkey) 2169 return -ENOMEM; 2170 2171 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 2172 if (!buf) { 2173 kvfree(buf_prevkey); 2174 return -ENOMEM; 2175 } 2176 2177 err = -EFAULT; 2178 prev_key = NULL; 2179 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 2180 goto free_buf; 2181 key = buf; 2182 value = key + map->key_size; 2183 if (ubatch) 2184 prev_key = buf_prevkey; 2185 2186 for (cp = 0; cp < max_count;) { 2187 rcu_read_lock(); 2188 err = map->ops->map_get_next_key(map, prev_key, key); 2189 rcu_read_unlock(); 2190 if (err) 2191 break; 2192 err = bpf_map_copy_value(map, key, value, 2193 attr->batch.elem_flags); 2194 2195 if (err == -ENOENT) 2196 goto next_key; 2197 2198 if (err) 2199 goto free_buf; 2200 2201 if (copy_to_user(keys + (size_t)cp * map->key_size, key, 2202 map->key_size)) { 2203 err = -EFAULT; 2204 goto free_buf; 2205 } 2206 if (copy_to_user(values + (size_t)cp * value_size, value, value_size)) { 2207 err = -EFAULT; 2208 goto free_buf; 2209 } 2210 2211 cp++; 2212 next_key: 2213 if (!prev_key) 2214 prev_key = buf_prevkey; 2215 2216 swap(prev_key, key); 2217 cond_resched(); 2218 } 2219 2220 if (err == -EFAULT) 2221 goto free_buf; 2222 2223 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 2224 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 2225 err = -EFAULT; 2226 2227 free_buf: 2228 kvfree(buf_prevkey); 2229 kvfree(buf); 2230 return err; 2231 } 2232 2233 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 2234 2235 static int map_lookup_and_delete_elem(union bpf_attr *attr) 2236 { 2237 void __user *ukey = u64_to_user_ptr(attr->key); 2238 void __user *uvalue = u64_to_user_ptr(attr->value); 2239 struct bpf_map *map; 2240 void *key, *value; 2241 u32 value_size; 2242 int err; 2243 2244 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 2245 return -EINVAL; 2246 2247 if (attr->flags & ~BPF_F_LOCK) 2248 return -EINVAL; 2249 2250 CLASS(fd, f)(attr->map_fd); 2251 map = __bpf_map_get(f); 2252 if (IS_ERR(map)) 2253 return PTR_ERR(map); 2254 bpf_map_write_active_inc(map); 2255 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 2256 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2257 err = -EPERM; 2258 goto err_put; 2259 } 2260 2261 if (attr->flags && 2262 (map->map_type == BPF_MAP_TYPE_QUEUE || 2263 map->map_type == BPF_MAP_TYPE_STACK)) { 2264 err = -EINVAL; 2265 goto err_put; 2266 } 2267 2268 if ((attr->flags & BPF_F_LOCK) && 2269 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2270 err = -EINVAL; 2271 goto err_put; 2272 } 2273 2274 key = __bpf_copy_key(ukey, map->key_size); 2275 if (IS_ERR(key)) { 2276 err = PTR_ERR(key); 2277 goto err_put; 2278 } 2279 2280 value_size = bpf_map_value_size(map, 0); 2281 2282 err = -ENOMEM; 2283 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2284 if (!value) 2285 goto free_key; 2286 2287 err = -ENOTSUPP; 2288 if (map->map_type == BPF_MAP_TYPE_QUEUE || 2289 map->map_type == BPF_MAP_TYPE_STACK) { 2290 err = map->ops->map_pop_elem(map, value); 2291 } else if (map->map_type == BPF_MAP_TYPE_HASH || 2292 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 2293 map->map_type == BPF_MAP_TYPE_LRU_HASH || 2294 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 2295 map->map_type == BPF_MAP_TYPE_RHASH || 2296 map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 2297 if (!bpf_map_is_offloaded(map)) { 2298 bpf_disable_instrumentation(); 2299 rcu_read_lock(); 2300 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 2301 rcu_read_unlock(); 2302 bpf_enable_instrumentation(); 2303 } 2304 } 2305 2306 if (err) 2307 goto free_value; 2308 2309 if (copy_to_user(uvalue, value, value_size) != 0) { 2310 err = -EFAULT; 2311 goto free_value; 2312 } 2313 2314 err = 0; 2315 2316 free_value: 2317 kvfree(value); 2318 free_key: 2319 kvfree(key); 2320 err_put: 2321 bpf_map_write_active_dec(map); 2322 return err; 2323 } 2324 2325 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2326 2327 static int map_freeze(const union bpf_attr *attr) 2328 { 2329 int err = 0; 2330 struct bpf_map *map; 2331 2332 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2333 return -EINVAL; 2334 2335 CLASS(fd, f)(attr->map_fd); 2336 map = __bpf_map_get(f); 2337 if (IS_ERR(map)) 2338 return PTR_ERR(map); 2339 2340 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) 2341 return -ENOTSUPP; 2342 2343 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) 2344 return -EPERM; 2345 2346 mutex_lock(&map->freeze_mutex); 2347 if (bpf_map_write_active(map)) { 2348 err = -EBUSY; 2349 goto err_put; 2350 } 2351 if (READ_ONCE(map->frozen)) { 2352 err = -EBUSY; 2353 goto err_put; 2354 } 2355 2356 WRITE_ONCE(map->frozen, true); 2357 err_put: 2358 mutex_unlock(&map->freeze_mutex); 2359 return err; 2360 } 2361 2362 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2363 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2364 [_id] = & _name ## _prog_ops, 2365 #define BPF_MAP_TYPE(_id, _ops) 2366 #define BPF_LINK_TYPE(_id, _name) 2367 #include <linux/bpf_types.h> 2368 #undef BPF_PROG_TYPE 2369 #undef BPF_MAP_TYPE 2370 #undef BPF_LINK_TYPE 2371 }; 2372 2373 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2374 { 2375 const struct bpf_prog_ops *ops; 2376 2377 if (type >= ARRAY_SIZE(bpf_prog_types)) 2378 return -EINVAL; 2379 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2380 ops = bpf_prog_types[type]; 2381 if (!ops) 2382 return -EINVAL; 2383 2384 if (!bpf_prog_is_offloaded(prog->aux)) 2385 prog->aux->ops = ops; 2386 else 2387 prog->aux->ops = &bpf_offload_prog_ops; 2388 prog->type = type; 2389 return 0; 2390 } 2391 2392 enum bpf_audit { 2393 BPF_AUDIT_LOAD, 2394 BPF_AUDIT_UNLOAD, 2395 BPF_AUDIT_MAX, 2396 }; 2397 2398 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2399 [BPF_AUDIT_LOAD] = "LOAD", 2400 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2401 }; 2402 2403 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2404 { 2405 struct audit_context *ctx = NULL; 2406 struct audit_buffer *ab; 2407 2408 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2409 return; 2410 if (audit_enabled == AUDIT_OFF) 2411 return; 2412 if (!in_hardirq() && !irqs_disabled()) 2413 ctx = audit_context(); 2414 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2415 if (unlikely(!ab)) 2416 return; 2417 audit_log_format(ab, "prog-id=%u op=%s", 2418 prog->aux->id, bpf_audit_str[op]); 2419 audit_log_end(ab); 2420 } 2421 2422 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2423 { 2424 int id; 2425 2426 idr_preload(GFP_KERNEL); 2427 spin_lock_bh(&prog_idr_lock); 2428 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2429 if (id > 0) 2430 prog->aux->id = id; 2431 spin_unlock_bh(&prog_idr_lock); 2432 idr_preload_end(); 2433 2434 /* id is in [1, INT_MAX) */ 2435 if (WARN_ON_ONCE(!id)) 2436 return -ENOSPC; 2437 2438 return id > 0 ? 0 : id; 2439 } 2440 2441 void bpf_prog_free_id(struct bpf_prog *prog) 2442 { 2443 unsigned long flags; 2444 2445 /* cBPF to eBPF migrations are currently not in the idr store. 2446 * Offloaded programs are removed from the store when their device 2447 * disappears - even if someone grabs an fd to them they are unusable, 2448 * simply waiting for refcnt to drop to be freed. 2449 */ 2450 if (!prog->aux->id) 2451 return; 2452 2453 spin_lock_irqsave(&prog_idr_lock, flags); 2454 idr_remove(&prog_idr, prog->aux->id); 2455 prog->aux->id = 0; 2456 spin_unlock_irqrestore(&prog_idr_lock, flags); 2457 } 2458 2459 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2460 { 2461 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2462 2463 btf_put(aux->btf); 2464 kvfree(aux->func_info); 2465 kfree(aux->func_info_aux); 2466 free_uid(aux->user); 2467 security_bpf_prog_free(aux->prog); 2468 bpf_prog_free(aux->prog); 2469 } 2470 2471 /* 2472 * Progs called from a trampoline can also be reached by a task that was 2473 * preempted in the trampoline before the prog's enter helper took its RCU 2474 * read lock, wait for those first. 2475 */ 2476 static void __bpf_prog_put_rcu_tasks(struct rcu_head *rcu) 2477 { 2478 struct bpf_prog *prog = container_of(rcu, struct bpf_prog_aux, rcu)->prog; 2479 2480 if (prog->sleepable) 2481 call_rcu_tasks_trace(rcu, __bpf_prog_put_rcu); 2482 else 2483 call_rcu(rcu, __bpf_prog_put_rcu); 2484 } 2485 2486 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2487 { 2488 bpf_prog_kallsyms_del_all(prog); 2489 module_put(prog->aux->mod); 2490 kvfree(prog->aux->jited_linfo); 2491 kvfree(prog->aux->linfo); 2492 kfree(prog->aux->kfunc_tab); 2493 kfree(prog->aux->ctx_arg_info); 2494 if (prog->aux->attach_btf) 2495 btf_put(prog->aux->attach_btf); 2496 2497 if (deferred) { 2498 if (IS_ENABLED(CONFIG_TASKS_RCU) && prog->aux->tramp_linked) 2499 call_rcu_tasks(&prog->aux->rcu, __bpf_prog_put_rcu_tasks); 2500 else if (prog->sleepable) 2501 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2502 else 2503 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2504 } else { 2505 __bpf_prog_put_rcu(&prog->aux->rcu); 2506 } 2507 } 2508 2509 static void bpf_prog_put_deferred(struct work_struct *work) 2510 { 2511 struct bpf_prog_aux *aux; 2512 struct bpf_prog *prog; 2513 2514 aux = container_of(work, struct bpf_prog_aux, work); 2515 prog = aux->prog; 2516 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2517 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2518 bpf_prog_free_id(prog); 2519 __bpf_prog_put_noref(prog, true); 2520 } 2521 2522 static void __bpf_prog_put(struct bpf_prog *prog) 2523 { 2524 struct bpf_prog_aux *aux = prog->aux; 2525 2526 if (atomic64_dec_and_test(&aux->refcnt)) { 2527 if (in_hardirq() || irqs_disabled()) { 2528 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2529 schedule_work(&aux->work); 2530 } else { 2531 bpf_prog_put_deferred(&aux->work); 2532 } 2533 } 2534 } 2535 2536 void bpf_prog_put(struct bpf_prog *prog) 2537 { 2538 __bpf_prog_put(prog); 2539 } 2540 EXPORT_SYMBOL_GPL(bpf_prog_put); 2541 2542 static int bpf_prog_release(struct inode *inode, struct file *filp) 2543 { 2544 struct bpf_prog *prog = filp->private_data; 2545 2546 bpf_prog_put(prog); 2547 return 0; 2548 } 2549 2550 struct bpf_prog_kstats { 2551 u64 nsecs; 2552 u64 cnt; 2553 u64 misses; 2554 }; 2555 2556 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2557 { 2558 struct bpf_prog_stats *stats; 2559 unsigned int flags; 2560 2561 if (unlikely(!prog->stats)) 2562 return; 2563 2564 stats = this_cpu_ptr(prog->stats); 2565 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2566 u64_stats_inc(&stats->misses); 2567 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2568 } 2569 2570 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2571 struct bpf_prog_kstats *stats) 2572 { 2573 u64 nsecs = 0, cnt = 0, misses = 0; 2574 int cpu; 2575 2576 for_each_possible_cpu(cpu) { 2577 const struct bpf_prog_stats *st; 2578 unsigned int start; 2579 u64 tnsecs, tcnt, tmisses; 2580 2581 st = per_cpu_ptr(prog->stats, cpu); 2582 do { 2583 start = u64_stats_fetch_begin(&st->syncp); 2584 tnsecs = u64_stats_read(&st->nsecs); 2585 tcnt = u64_stats_read(&st->cnt); 2586 tmisses = u64_stats_read(&st->misses); 2587 } while (u64_stats_fetch_retry(&st->syncp, start)); 2588 nsecs += tnsecs; 2589 cnt += tcnt; 2590 misses += tmisses; 2591 } 2592 stats->nsecs = nsecs; 2593 stats->cnt = cnt; 2594 stats->misses = misses; 2595 } 2596 2597 #ifdef CONFIG_PROC_FS 2598 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2599 { 2600 const struct bpf_prog *prog = filp->private_data; 2601 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2602 struct bpf_prog_kstats stats; 2603 2604 bpf_prog_get_stats(prog, &stats); 2605 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2606 seq_printf(m, 2607 "prog_type:\t%u\n" 2608 "prog_jited:\t%u\n" 2609 "prog_tag:\t%s\n" 2610 "memlock:\t%llu\n" 2611 "prog_id:\t%u\n" 2612 "run_time_ns:\t%llu\n" 2613 "run_cnt:\t%llu\n" 2614 "recursion_misses:\t%llu\n" 2615 "verified_insns:\t%u\n", 2616 prog->type, 2617 prog->jited, 2618 prog_tag, 2619 prog->pages * 1ULL << PAGE_SHIFT, 2620 prog->aux->id, 2621 stats.nsecs, 2622 stats.cnt, 2623 stats.misses, 2624 prog->aux->verified_insns); 2625 } 2626 #endif 2627 2628 const struct file_operations bpf_prog_fops = { 2629 #ifdef CONFIG_PROC_FS 2630 .show_fdinfo = bpf_prog_show_fdinfo, 2631 #endif 2632 .release = bpf_prog_release, 2633 .read = bpf_dummy_read, 2634 .write = bpf_dummy_write, 2635 }; 2636 2637 int bpf_prog_new_fd(struct bpf_prog *prog) 2638 { 2639 int ret; 2640 2641 ret = security_bpf_prog(prog); 2642 if (ret < 0) 2643 return ret; 2644 2645 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2646 O_RDWR | O_CLOEXEC); 2647 } 2648 2649 void bpf_prog_add(struct bpf_prog *prog, int i) 2650 { 2651 atomic64_add(i, &prog->aux->refcnt); 2652 } 2653 EXPORT_SYMBOL_GPL(bpf_prog_add); 2654 2655 void bpf_prog_sub(struct bpf_prog *prog, int i) 2656 { 2657 /* Only to be used for undoing previous bpf_prog_add() in some 2658 * error path. We still know that another entity in our call 2659 * path holds a reference to the program, thus atomic_sub() can 2660 * be safely used in such cases! 2661 */ 2662 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2663 } 2664 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2665 2666 void bpf_prog_inc(struct bpf_prog *prog) 2667 { 2668 atomic64_inc(&prog->aux->refcnt); 2669 } 2670 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2671 2672 /* prog_idr_lock should have been held */ 2673 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2674 { 2675 int refold; 2676 2677 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2678 2679 if (!refold) 2680 return ERR_PTR(-ENOENT); 2681 2682 return prog; 2683 } 2684 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2685 2686 bool bpf_prog_get_ok(struct bpf_prog *prog, 2687 enum bpf_prog_type *attach_type, bool attach_drv) 2688 { 2689 /* not an attachment, just a refcount inc, always allow */ 2690 if (!attach_type) 2691 return true; 2692 2693 if (prog->type != *attach_type) 2694 return false; 2695 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2696 return false; 2697 2698 return true; 2699 } 2700 2701 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2702 bool attach_drv) 2703 { 2704 CLASS(fd, f)(ufd); 2705 struct bpf_prog *prog; 2706 2707 if (fd_empty(f)) 2708 return ERR_PTR(-EBADF); 2709 if (fd_file(f)->f_op != &bpf_prog_fops) 2710 return ERR_PTR(-EINVAL); 2711 2712 prog = fd_file(f)->private_data; 2713 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2714 return ERR_PTR(-EINVAL); 2715 2716 bpf_prog_inc(prog); 2717 return prog; 2718 } 2719 2720 struct bpf_prog *bpf_prog_get(u32 ufd) 2721 { 2722 return __bpf_prog_get(ufd, NULL, false); 2723 } 2724 2725 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2726 bool attach_drv) 2727 { 2728 return __bpf_prog_get(ufd, &type, attach_drv); 2729 } 2730 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2731 2732 /* Initially all BPF programs could be loaded w/o specifying 2733 * expected_attach_type. Later for some of them specifying expected_attach_type 2734 * at load time became required so that program could be validated properly. 2735 * Programs of types that are allowed to be loaded both w/ and w/o (for 2736 * backward compatibility) expected_attach_type, should have the default attach 2737 * type assigned to expected_attach_type for the latter case, so that it can be 2738 * validated later at attach time. 2739 * 2740 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2741 * prog type requires it but has some attach types that have to be backward 2742 * compatible. 2743 */ 2744 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2745 { 2746 switch (attr->prog_type) { 2747 case BPF_PROG_TYPE_CGROUP_SOCK: 2748 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2749 * exist so checking for non-zero is the way to go here. 2750 */ 2751 if (!attr->expected_attach_type) 2752 attr->expected_attach_type = 2753 BPF_CGROUP_INET_SOCK_CREATE; 2754 break; 2755 case BPF_PROG_TYPE_SK_REUSEPORT: 2756 if (!attr->expected_attach_type) 2757 attr->expected_attach_type = 2758 BPF_SK_REUSEPORT_SELECT; 2759 break; 2760 } 2761 } 2762 2763 static int 2764 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2765 enum bpf_attach_type expected_attach_type, 2766 struct btf *attach_btf, u32 btf_id, 2767 struct bpf_prog *dst_prog, 2768 bool multi_func) 2769 { 2770 if (btf_id) { 2771 if (btf_id > BTF_MAX_TYPE) 2772 return -EINVAL; 2773 2774 if (!attach_btf && !dst_prog) 2775 return -EINVAL; 2776 2777 switch (prog_type) { 2778 case BPF_PROG_TYPE_TRACING: 2779 case BPF_PROG_TYPE_LSM: 2780 case BPF_PROG_TYPE_STRUCT_OPS: 2781 case BPF_PROG_TYPE_EXT: 2782 break; 2783 default: 2784 return -EINVAL; 2785 } 2786 } 2787 2788 if (multi_func) { 2789 if (prog_type != BPF_PROG_TYPE_TRACING) 2790 return -EINVAL; 2791 if (!attach_btf || btf_id) 2792 return -EINVAL; 2793 return 0; 2794 } 2795 2796 if (attach_btf && (!btf_id || dst_prog)) 2797 return -EINVAL; 2798 2799 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2800 prog_type != BPF_PROG_TYPE_EXT) 2801 return -EINVAL; 2802 2803 switch (prog_type) { 2804 case BPF_PROG_TYPE_CGROUP_SOCK: 2805 switch (expected_attach_type) { 2806 case BPF_CGROUP_INET_SOCK_CREATE: 2807 case BPF_CGROUP_INET_SOCK_RELEASE: 2808 case BPF_CGROUP_INET4_POST_BIND: 2809 case BPF_CGROUP_INET6_POST_BIND: 2810 return 0; 2811 default: 2812 return -EINVAL; 2813 } 2814 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2815 switch (expected_attach_type) { 2816 case BPF_CGROUP_INET4_BIND: 2817 case BPF_CGROUP_INET6_BIND: 2818 case BPF_CGROUP_INET4_CONNECT: 2819 case BPF_CGROUP_INET6_CONNECT: 2820 case BPF_CGROUP_UNIX_CONNECT: 2821 case BPF_CGROUP_INET4_GETPEERNAME: 2822 case BPF_CGROUP_INET6_GETPEERNAME: 2823 case BPF_CGROUP_UNIX_GETPEERNAME: 2824 case BPF_CGROUP_INET4_GETSOCKNAME: 2825 case BPF_CGROUP_INET6_GETSOCKNAME: 2826 case BPF_CGROUP_UNIX_GETSOCKNAME: 2827 case BPF_CGROUP_UDP4_SENDMSG: 2828 case BPF_CGROUP_UDP6_SENDMSG: 2829 case BPF_CGROUP_UNIX_SENDMSG: 2830 case BPF_CGROUP_UDP4_RECVMSG: 2831 case BPF_CGROUP_UDP6_RECVMSG: 2832 case BPF_CGROUP_UNIX_RECVMSG: 2833 return 0; 2834 default: 2835 return -EINVAL; 2836 } 2837 case BPF_PROG_TYPE_CGROUP_SKB: 2838 switch (expected_attach_type) { 2839 case BPF_CGROUP_INET_INGRESS: 2840 case BPF_CGROUP_INET_EGRESS: 2841 return 0; 2842 default: 2843 return -EINVAL; 2844 } 2845 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2846 switch (expected_attach_type) { 2847 case BPF_CGROUP_SETSOCKOPT: 2848 case BPF_CGROUP_GETSOCKOPT: 2849 return 0; 2850 default: 2851 return -EINVAL; 2852 } 2853 case BPF_PROG_TYPE_SK_LOOKUP: 2854 if (expected_attach_type == BPF_SK_LOOKUP) 2855 return 0; 2856 return -EINVAL; 2857 case BPF_PROG_TYPE_SK_REUSEPORT: 2858 switch (expected_attach_type) { 2859 case BPF_SK_REUSEPORT_SELECT: 2860 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2861 return 0; 2862 default: 2863 return -EINVAL; 2864 } 2865 case BPF_PROG_TYPE_NETFILTER: 2866 if (expected_attach_type == BPF_NETFILTER) 2867 return 0; 2868 return -EINVAL; 2869 case BPF_PROG_TYPE_SYSCALL: 2870 case BPF_PROG_TYPE_EXT: 2871 if (expected_attach_type) 2872 return -EINVAL; 2873 fallthrough; 2874 default: 2875 return 0; 2876 } 2877 } 2878 2879 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2880 { 2881 switch (prog_type) { 2882 case BPF_PROG_TYPE_SCHED_CLS: 2883 case BPF_PROG_TYPE_SCHED_ACT: 2884 case BPF_PROG_TYPE_XDP: 2885 case BPF_PROG_TYPE_LWT_IN: 2886 case BPF_PROG_TYPE_LWT_OUT: 2887 case BPF_PROG_TYPE_LWT_XMIT: 2888 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2889 case BPF_PROG_TYPE_SK_SKB: 2890 case BPF_PROG_TYPE_SK_MSG: 2891 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2892 case BPF_PROG_TYPE_CGROUP_DEVICE: 2893 case BPF_PROG_TYPE_CGROUP_SOCK: 2894 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2895 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2896 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2897 case BPF_PROG_TYPE_SOCK_OPS: 2898 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2899 case BPF_PROG_TYPE_NETFILTER: 2900 return true; 2901 case BPF_PROG_TYPE_CGROUP_SKB: 2902 /* always unpriv */ 2903 case BPF_PROG_TYPE_SK_REUSEPORT: 2904 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2905 default: 2906 return false; 2907 } 2908 } 2909 2910 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2911 { 2912 switch (prog_type) { 2913 case BPF_PROG_TYPE_KPROBE: 2914 case BPF_PROG_TYPE_TRACEPOINT: 2915 case BPF_PROG_TYPE_PERF_EVENT: 2916 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2917 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2918 case BPF_PROG_TYPE_TRACING: 2919 case BPF_PROG_TYPE_LSM: 2920 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2921 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2922 return true; 2923 default: 2924 return false; 2925 } 2926 } 2927 2928 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) 2929 { 2930 int err; 2931 int i; 2932 2933 for (i = 0; i < prog->aux->used_map_cnt; i++) { 2934 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY) 2935 continue; 2936 2937 err = bpf_insn_array_ready(prog->aux->used_maps[i]); 2938 if (err) 2939 return err; 2940 } 2941 2942 return 0; 2943 } 2944 2945 extern int bpf_multi_func(void); 2946 int __init __used bpf_multi_func(void) { return 0; } 2947 2948 BTF_ID_LIST_GLOBAL_SINGLE(bpf_multi_func_btf_id, func, bpf_multi_func) 2949 2950 /* last field in 'union bpf_attr' used by this command */ 2951 #define BPF_PROG_LOAD_LAST_FIELD keyring_id 2952 2953 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 2954 { 2955 enum bpf_prog_type type = attr->prog_type; 2956 struct bpf_prog *prog, *dst_prog = NULL; 2957 struct btf *attach_btf = NULL; 2958 struct bpf_token *token = NULL; 2959 bool bpf_cap; 2960 int err; 2961 char license[128]; 2962 bool multi_func; 2963 2964 if (CHECK_ATTR(BPF_PROG_LOAD)) 2965 return -EINVAL; 2966 2967 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2968 BPF_F_ANY_ALIGNMENT | 2969 BPF_F_TEST_STATE_FREQ | 2970 BPF_F_SLEEPABLE | 2971 BPF_F_TEST_RND_HI32 | 2972 BPF_F_XDP_HAS_FRAGS | 2973 BPF_F_XDP_DEV_BOUND_ONLY | 2974 BPF_F_TEST_REG_INVARIANTS | 2975 BPF_F_TOKEN_FD)) 2976 return -EINVAL; 2977 2978 bpf_prog_load_fixup_attach_type(attr); 2979 2980 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2981 token = bpf_token_get_from_fd(attr->prog_token_fd); 2982 if (IS_ERR(token)) 2983 return PTR_ERR(token); 2984 /* if current token doesn't grant prog loading permissions, 2985 * then we can't use this token, so ignore it and rely on 2986 * system-wide capabilities checks 2987 */ 2988 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2989 !bpf_token_allow_prog_type(token, attr->prog_type, 2990 attr->expected_attach_type)) { 2991 bpf_token_put(token); 2992 token = NULL; 2993 } 2994 } 2995 2996 bpf_cap = bpf_token_capable(token, CAP_BPF); 2997 err = -EPERM; 2998 2999 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 3000 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 3001 !bpf_cap) 3002 goto put_token; 3003 3004 /* Intent here is for unprivileged_bpf_disabled to block BPF program 3005 * creation for unprivileged users; other actions depend 3006 * on fd availability and access to bpffs, so are dependent on 3007 * object creation success. Even with unprivileged BPF disabled, 3008 * capability checks are still carried out for these 3009 * and other operations. 3010 */ 3011 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 3012 goto put_token; 3013 3014 if (attr->insn_cnt == 0 || 3015 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 3016 err = -E2BIG; 3017 goto put_token; 3018 } 3019 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 3020 type != BPF_PROG_TYPE_CGROUP_SKB && 3021 !bpf_cap) 3022 goto put_token; 3023 3024 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 3025 goto put_token; 3026 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 3027 goto put_token; 3028 3029 multi_func = is_tracing_multi(attr->expected_attach_type); 3030 3031 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 3032 * or btf, we need to check which one it is 3033 */ 3034 if (attr->attach_prog_fd) { 3035 dst_prog = bpf_prog_get(attr->attach_prog_fd); 3036 if (IS_ERR(dst_prog)) { 3037 dst_prog = NULL; 3038 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 3039 if (IS_ERR(attach_btf)) { 3040 err = -EINVAL; 3041 goto put_token; 3042 } 3043 if (!btf_is_kernel(attach_btf)) { 3044 /* attaching through specifying bpf_prog's BTF 3045 * objects directly might be supported eventually 3046 */ 3047 btf_put(attach_btf); 3048 err = -ENOTSUPP; 3049 goto put_token; 3050 } 3051 } 3052 } else if (attr->attach_btf_id || multi_func) { 3053 /* fall back to vmlinux BTF, if BTF type ID is specified */ 3054 attach_btf = bpf_get_btf_vmlinux(); 3055 if (IS_ERR(attach_btf)) { 3056 err = PTR_ERR(attach_btf); 3057 goto put_token; 3058 } 3059 if (!attach_btf) { 3060 err = -EINVAL; 3061 goto put_token; 3062 } 3063 btf_get(attach_btf); 3064 } 3065 3066 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 3067 attach_btf, attr->attach_btf_id, 3068 dst_prog, multi_func)) { 3069 if (dst_prog) 3070 bpf_prog_put(dst_prog); 3071 if (attach_btf) 3072 btf_put(attach_btf); 3073 err = -EINVAL; 3074 goto put_token; 3075 } 3076 3077 /* plain bpf_prog allocation */ 3078 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 3079 if (!prog) { 3080 if (dst_prog) 3081 bpf_prog_put(dst_prog); 3082 if (attach_btf) 3083 btf_put(attach_btf); 3084 err = -EINVAL; 3085 goto put_token; 3086 } 3087 3088 prog->expected_attach_type = attr->expected_attach_type; 3089 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 3090 prog->aux->attach_btf = attach_btf; 3091 prog->aux->attach_btf_id = multi_func ? bpf_multi_func_btf_id[0] : attr->attach_btf_id; 3092 prog->aux->dst_prog = dst_prog; 3093 if (dst_prog) { 3094 prog->aux->saved_dst_prog_type = dst_prog->type; 3095 prog->aux->saved_dst_attach_type = dst_prog->expected_attach_type; 3096 } 3097 prog->aux->dev_bound = !!attr->prog_ifindex; 3098 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 3099 3100 /* move token into prog->aux, reuse taken refcnt */ 3101 prog->aux->token = token; 3102 token = NULL; 3103 3104 prog->aux->user = get_current_user(); 3105 prog->len = attr->insn_cnt; 3106 3107 err = bpf_prog_stream_init(prog, GFP_USER); 3108 if (err) 3109 goto free_prog; 3110 3111 err = -EFAULT; 3112 if (copy_from_bpfptr(prog->insns, 3113 make_bpfptr(attr->insns, uattr.is_kernel), 3114 bpf_prog_insn_size(prog)) != 0) 3115 goto free_prog; 3116 /* copy eBPF program license from user space */ 3117 if (strncpy_from_bpfptr(license, 3118 make_bpfptr(attr->license, uattr.is_kernel), 3119 sizeof(license) - 1) < 0) 3120 goto free_prog; 3121 license[sizeof(license) - 1] = 0; 3122 3123 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 3124 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 3125 prog->aux->sig.keyring_type = BPF_SIG_KEYRING_NONE; 3126 prog->aux->sig.verdict = BPF_SIG_UNSIGNED; 3127 prog->orig_prog = NULL; 3128 prog->jited = 0; 3129 3130 atomic64_set(&prog->aux->refcnt, 1); 3131 3132 if (bpf_prog_is_dev_bound(prog->aux)) { 3133 err = bpf_prog_dev_bound_init(prog, attr); 3134 if (err) 3135 goto free_prog; 3136 } 3137 3138 if (type == BPF_PROG_TYPE_EXT && dst_prog && 3139 bpf_prog_is_dev_bound(dst_prog->aux)) { 3140 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 3141 if (err) 3142 goto free_prog; 3143 } 3144 3145 /* 3146 * Bookkeeping for managing the program attachment chain. 3147 * 3148 * It might be tempting to set attach_tracing_prog flag at the attachment 3149 * time, but this will not prevent from loading bunch of tracing prog 3150 * first, then attach them one to another. 3151 * 3152 * The flag attach_tracing_prog is set for the whole program lifecycle, and 3153 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 3154 * programs cannot change attachment target. 3155 */ 3156 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 3157 dst_prog->type == BPF_PROG_TYPE_TRACING) { 3158 prog->aux->attach_tracing_prog = true; 3159 } 3160 3161 /* find program type: socket_filter vs tracing_filter */ 3162 err = find_prog_type(type, prog); 3163 if (err < 0) 3164 goto free_prog; 3165 3166 prog->aux->load_time = ktime_get_boottime_ns(); 3167 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 3168 sizeof(attr->prog_name)); 3169 if (err < 0) 3170 goto free_prog; 3171 3172 /* run eBPF verifier */ 3173 err = bpf_check(&prog, attr, uattr, attr_log); 3174 if (err < 0) 3175 goto free_used_maps; 3176 3177 err = bpf_prog_mark_insn_arrays_ready(prog); 3178 if (err < 0) 3179 goto free_used_maps; 3180 3181 err = bpf_prog_alloc_id(prog); 3182 if (err) 3183 goto free_used_maps; 3184 3185 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 3186 * effectively publicly exposed. However, retrieving via 3187 * bpf_prog_get_fd_by_id() will take another reference, 3188 * therefore it cannot be gone underneath us. 3189 * 3190 * Only for the time /after/ successful bpf_prog_new_fd() 3191 * and before returning to userspace, we might just hold 3192 * one reference and any parallel close on that fd could 3193 * rip everything out. Hence, below notifications must 3194 * happen before bpf_prog_new_fd(). 3195 * 3196 * Also, any failure handling from this point onwards must 3197 * be using bpf_prog_put() given the program is exposed. 3198 */ 3199 bpf_prog_kallsyms_add(prog); 3200 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 3201 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 3202 3203 err = bpf_prog_new_fd(prog); 3204 if (err < 0) 3205 bpf_prog_put(prog); 3206 return err; 3207 3208 free_used_maps: 3209 /* In case we have subprogs, we need to wait for a grace 3210 * period before we can tear down JIT memory since symbols 3211 * are already exposed under kallsyms. 3212 */ 3213 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 3214 return err; 3215 3216 free_prog: 3217 free_uid(prog->aux->user); 3218 if (prog->aux->attach_btf) 3219 btf_put(prog->aux->attach_btf); 3220 bpf_prog_free(prog); 3221 put_token: 3222 bpf_token_put(token); 3223 return err; 3224 } 3225 3226 #define BPF_OBJ_LAST_FIELD path_fd 3227 3228 static int bpf_obj_pin(const union bpf_attr *attr) 3229 { 3230 int path_fd; 3231 3232 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3233 return -EINVAL; 3234 3235 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3236 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3237 return -EINVAL; 3238 3239 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3240 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3241 u64_to_user_ptr(attr->pathname)); 3242 } 3243 3244 static int bpf_obj_get(const union bpf_attr *attr) 3245 { 3246 int path_fd; 3247 3248 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3249 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3250 return -EINVAL; 3251 3252 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3253 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3254 return -EINVAL; 3255 3256 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3257 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3258 attr->file_flags); 3259 } 3260 3261 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3262 * "sleepable" semantics, which normally would mean that BPF link's attach 3263 * hook can dereference link or link's underlying program for some time after 3264 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3265 * BPF program itself can be non-sleepable, yet, because it's transitively 3266 * reachable through BPF link, its freeing has to be delayed until after RCU 3267 * Tasks Trace GP. 3268 */ 3269 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3270 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3271 enum bpf_attach_type attach_type, bool sleepable) 3272 { 3273 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3274 atomic64_set(&link->refcnt, 1); 3275 link->type = type; 3276 link->sleepable = sleepable; 3277 link->id = 0; 3278 link->ops = ops; 3279 link->prog = prog; 3280 link->attach_type = attach_type; 3281 } 3282 3283 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3284 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3285 enum bpf_attach_type attach_type) 3286 { 3287 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); 3288 } 3289 3290 void bpf_tramp_link_init(struct bpf_tramp_link *link, enum bpf_link_type type, 3291 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3292 enum bpf_attach_type attach_type, u64 cookie) 3293 { 3294 bpf_link_init(&link->link, type, ops, prog, attach_type); 3295 link->node.link = &link->link; 3296 link->node.cookie = cookie; 3297 } 3298 3299 static void bpf_link_free_id(int id) 3300 { 3301 if (!id) 3302 return; 3303 3304 spin_lock_bh(&link_idr_lock); 3305 idr_remove(&link_idr, id); 3306 spin_unlock_bh(&link_idr_lock); 3307 } 3308 3309 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3310 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3311 * anon_inode's release() call. This helper marks bpf_link as 3312 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3313 * is not decremented, it's the responsibility of a calling code that failed 3314 * to complete bpf_link initialization. 3315 * This helper eventually calls link's dealloc callback, but does not call 3316 * link's release callback. 3317 */ 3318 void bpf_link_cleanup(struct bpf_link_primer *primer) 3319 { 3320 primer->link->prog = NULL; 3321 bpf_link_free_id(primer->id); 3322 fput(primer->file); 3323 put_unused_fd(primer->fd); 3324 } 3325 3326 void bpf_link_inc(struct bpf_link *link) 3327 { 3328 atomic64_inc(&link->refcnt); 3329 } 3330 3331 static void bpf_link_dealloc(struct bpf_link *link) 3332 { 3333 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3334 if (link->prog) 3335 bpf_prog_put(link->prog); 3336 3337 /* free bpf_link and its containing memory */ 3338 if (link->ops->dealloc_deferred) 3339 link->ops->dealloc_deferred(link); 3340 else 3341 link->ops->dealloc(link); 3342 } 3343 3344 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3345 { 3346 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3347 3348 bpf_link_dealloc(link); 3349 } 3350 3351 static bool bpf_link_is_tracepoint(struct bpf_link *link) 3352 { 3353 /* 3354 * Only these combinations support a tracepoint bpf_link. 3355 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use 3356 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see 3357 * bpf_raw_tp_link_attach(). 3358 */ 3359 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT || 3360 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP); 3361 } 3362 3363 /* bpf_link_free is guaranteed to be called from process context */ 3364 static void bpf_link_free(struct bpf_link *link) 3365 { 3366 const struct bpf_link_ops *ops = link->ops; 3367 3368 bpf_link_free_id(link->id); 3369 /* detach BPF program, clean up used resources */ 3370 if (link->prog) 3371 ops->release(link); 3372 if (ops->dealloc_deferred) { 3373 /* 3374 * Schedule BPF link deallocation, which will only then 3375 * trigger putting BPF program refcount. 3376 * If underlying BPF program is sleepable or BPF link's target 3377 * attach hookpoint is sleepable or otherwise requires RCU GPs 3378 * to ensure link and its underlying BPF program is not 3379 * reachable anymore, we need to first wait for RCU tasks 3380 * trace sync, and then go through "classic" RCU grace period. 3381 * 3382 * For tracepoint BPF links, we need to go through SRCU grace 3383 * period wait instead when non-faultable tracepoint is used. We 3384 * don't need to chain SRCU grace period waits, however, for the 3385 * faultable case, since it exclusively uses RCU Tasks Trace. 3386 */ 3387 if (link->sleepable || (link->prog && link->prog->sleepable)) 3388 /* RCU Tasks Trace grace period implies RCU grace period. */ 3389 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3390 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */ 3391 else if (bpf_link_is_tracepoint(link)) 3392 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3393 else 3394 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3395 } else if (ops->dealloc) { 3396 bpf_link_dealloc(link); 3397 } 3398 } 3399 3400 static void bpf_link_put_deferred(struct work_struct *work) 3401 { 3402 struct bpf_link *link = container_of(work, struct bpf_link, work); 3403 3404 bpf_link_free(link); 3405 } 3406 3407 /* bpf_link_put might be called from atomic context. It needs to be called 3408 * from sleepable context in order to acquire sleeping locks during the process. 3409 */ 3410 void bpf_link_put(struct bpf_link *link) 3411 { 3412 if (!atomic64_dec_and_test(&link->refcnt)) 3413 return; 3414 3415 INIT_WORK(&link->work, bpf_link_put_deferred); 3416 schedule_work(&link->work); 3417 } 3418 EXPORT_SYMBOL(bpf_link_put); 3419 3420 static void bpf_link_put_direct(struct bpf_link *link) 3421 { 3422 if (!atomic64_dec_and_test(&link->refcnt)) 3423 return; 3424 bpf_link_free(link); 3425 } 3426 3427 static int bpf_link_release(struct inode *inode, struct file *filp) 3428 { 3429 struct bpf_link *link = filp->private_data; 3430 3431 bpf_link_put_direct(link); 3432 return 0; 3433 } 3434 3435 #ifdef CONFIG_PROC_FS 3436 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3437 #define BPF_MAP_TYPE(_id, _ops) 3438 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3439 static const char *bpf_link_type_strs[] = { 3440 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3441 #include <linux/bpf_types.h> 3442 }; 3443 #undef BPF_PROG_TYPE 3444 #undef BPF_MAP_TYPE 3445 #undef BPF_LINK_TYPE 3446 3447 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3448 { 3449 const struct bpf_link *link = filp->private_data; 3450 const struct bpf_prog *prog; 3451 enum bpf_link_type type = link->type; 3452 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3453 u32 prog_id = 0; 3454 3455 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3456 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) 3457 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? 3458 "kretprobe_multi" : "kprobe_multi"); 3459 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) 3460 seq_printf(m, "link_type:\t%s\n", link->flags & BPF_F_UPROBE_MULTI_RETURN ? 3461 "uretprobe_multi" : "uprobe_multi"); 3462 else 3463 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3464 } else { 3465 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3466 seq_printf(m, "link_type:\t<%u>\n", type); 3467 } 3468 seq_printf(m, "link_id:\t%u\n", link->id); 3469 3470 rcu_read_lock(); 3471 prog = READ_ONCE(link->prog); 3472 if (prog) { 3473 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3474 prog_id = prog->aux->id; 3475 } 3476 rcu_read_unlock(); 3477 3478 if (prog) { 3479 seq_printf(m, 3480 "prog_tag:\t%s\n" 3481 "prog_id:\t%u\n", 3482 prog_tag, 3483 prog_id); 3484 } 3485 if (link->ops->show_fdinfo) 3486 link->ops->show_fdinfo(link, m); 3487 } 3488 #endif 3489 3490 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3491 { 3492 struct bpf_link *link = file->private_data; 3493 3494 return link->ops->poll(file, pts); 3495 } 3496 3497 static const struct file_operations bpf_link_fops = { 3498 #ifdef CONFIG_PROC_FS 3499 .show_fdinfo = bpf_link_show_fdinfo, 3500 #endif 3501 .release = bpf_link_release, 3502 .read = bpf_dummy_read, 3503 .write = bpf_dummy_write, 3504 }; 3505 3506 static const struct file_operations bpf_link_fops_poll = { 3507 #ifdef CONFIG_PROC_FS 3508 .show_fdinfo = bpf_link_show_fdinfo, 3509 #endif 3510 .release = bpf_link_release, 3511 .read = bpf_dummy_read, 3512 .write = bpf_dummy_write, 3513 .poll = bpf_link_poll, 3514 }; 3515 3516 static int bpf_link_alloc_id(struct bpf_link *link) 3517 { 3518 int id; 3519 3520 idr_preload(GFP_KERNEL); 3521 spin_lock_bh(&link_idr_lock); 3522 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3523 spin_unlock_bh(&link_idr_lock); 3524 idr_preload_end(); 3525 3526 return id; 3527 } 3528 3529 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3530 * reserving unused FD and allocating ID from link_idr. This is to be paired 3531 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3532 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3533 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3534 * transient state is passed around in struct bpf_link_primer. 3535 * This is preferred way to create and initialize bpf_link, especially when 3536 * there are complicated and expensive operations in between creating bpf_link 3537 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3538 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3539 * expensive (and potentially failing) roll back operations in a rare case 3540 * that file, FD, or ID can't be allocated. 3541 */ 3542 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3543 { 3544 struct file *file; 3545 int fd, id; 3546 3547 fd = get_unused_fd_flags(O_CLOEXEC); 3548 if (fd < 0) 3549 return fd; 3550 3551 id = bpf_link_alloc_id(link); 3552 if (id < 0) { 3553 put_unused_fd(fd); 3554 return id; 3555 } 3556 3557 file = anon_inode_getfile("bpf_link", 3558 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3559 link, O_CLOEXEC); 3560 if (IS_ERR(file)) { 3561 bpf_link_free_id(id); 3562 put_unused_fd(fd); 3563 return PTR_ERR(file); 3564 } 3565 3566 primer->link = link; 3567 primer->file = file; 3568 primer->fd = fd; 3569 primer->id = id; 3570 return 0; 3571 } 3572 3573 int bpf_link_settle(struct bpf_link_primer *primer) 3574 { 3575 /* make bpf_link fetchable by ID */ 3576 spin_lock_bh(&link_idr_lock); 3577 primer->link->id = primer->id; 3578 spin_unlock_bh(&link_idr_lock); 3579 /* make bpf_link fetchable by FD */ 3580 fd_install(primer->fd, primer->file); 3581 /* pass through installed FD */ 3582 return primer->fd; 3583 } 3584 3585 int bpf_link_new_fd(struct bpf_link *link) 3586 { 3587 return anon_inode_getfd("bpf-link", 3588 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3589 link, O_CLOEXEC); 3590 } 3591 3592 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3593 { 3594 CLASS(fd, f)(ufd); 3595 struct bpf_link *link; 3596 3597 if (fd_empty(f)) 3598 return ERR_PTR(-EBADF); 3599 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3600 return ERR_PTR(-EINVAL); 3601 3602 link = fd_file(f)->private_data; 3603 bpf_link_inc(link); 3604 return link; 3605 } 3606 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); 3607 3608 static void bpf_tracing_link_release(struct bpf_link *link) 3609 { 3610 struct bpf_tracing_link *tr_link = 3611 container_of(link, struct bpf_tracing_link, link.link); 3612 int err; 3613 3614 err = bpf_trampoline_unlink_prog(&tr_link->link.node, 3615 tr_link->trampoline, 3616 tr_link->tgt_prog); 3617 WARN_ONCE(err, "bpf_trampoline_unlink_prog failed: %d\n", err); 3618 3619 bpf_trampoline_put(tr_link->trampoline); 3620 3621 /* tgt_prog is NULL if target is a kernel function */ 3622 if (tr_link->tgt_prog) 3623 bpf_prog_put(tr_link->tgt_prog); 3624 } 3625 3626 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3627 { 3628 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3629 3630 kfree(tr_link); 3631 } 3632 3633 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3634 struct seq_file *seq) 3635 { 3636 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3637 3638 u32 target_btf_id, target_obj_id; 3639 3640 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3641 &target_obj_id, &target_btf_id); 3642 seq_printf(seq, 3643 "attach_type:\t%d\n" 3644 "target_obj_id:\t%u\n" 3645 "target_btf_id:\t%u\n" 3646 "cookie:\t%llu\n", 3647 link->attach_type, 3648 target_obj_id, 3649 target_btf_id, 3650 tr_link->link.node.cookie); 3651 } 3652 3653 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3654 struct bpf_link_info *info) 3655 { 3656 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3657 3658 info->tracing.attach_type = link->attach_type; 3659 info->tracing.cookie = tr_link->link.node.cookie; 3660 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3661 &info->tracing.target_obj_id, 3662 &info->tracing.target_btf_id); 3663 3664 return 0; 3665 } 3666 3667 static const struct bpf_link_ops bpf_tracing_link_lops = { 3668 .release = bpf_tracing_link_release, 3669 .dealloc = bpf_tracing_link_dealloc, 3670 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3671 .fill_link_info = bpf_tracing_link_fill_link_info, 3672 }; 3673 3674 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3675 int tgt_prog_fd, 3676 u32 btf_id, 3677 u64 bpf_cookie, 3678 enum bpf_attach_type attach_type) 3679 { 3680 struct bpf_link_primer link_primer; 3681 struct bpf_prog *tgt_prog = NULL; 3682 struct bpf_trampoline *tr = NULL; 3683 struct bpf_tracing_link *link; 3684 u64 key = 0; 3685 int err; 3686 3687 switch (prog->type) { 3688 case BPF_PROG_TYPE_TRACING: 3689 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3690 prog->expected_attach_type != BPF_TRACE_FEXIT && 3691 prog->expected_attach_type != BPF_TRACE_FSESSION && 3692 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3693 err = -EINVAL; 3694 goto out_put_prog; 3695 } 3696 break; 3697 case BPF_PROG_TYPE_EXT: 3698 if (prog->expected_attach_type != 0) { 3699 err = -EINVAL; 3700 goto out_put_prog; 3701 } 3702 break; 3703 case BPF_PROG_TYPE_LSM: 3704 if (prog->expected_attach_type != BPF_LSM_MAC) { 3705 err = -EINVAL; 3706 goto out_put_prog; 3707 } 3708 break; 3709 default: 3710 err = -EINVAL; 3711 goto out_put_prog; 3712 } 3713 3714 if (!!tgt_prog_fd != !!btf_id) { 3715 err = -EINVAL; 3716 goto out_put_prog; 3717 } 3718 3719 if (tgt_prog_fd) { 3720 /* 3721 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3722 * part would be changed to implement the same for 3723 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3724 * attach_tracing_prog flag is set. 3725 */ 3726 if (prog->type != BPF_PROG_TYPE_EXT) { 3727 err = -EINVAL; 3728 goto out_put_prog; 3729 } 3730 3731 tgt_prog = bpf_prog_get(tgt_prog_fd); 3732 if (IS_ERR(tgt_prog)) { 3733 err = PTR_ERR(tgt_prog); 3734 tgt_prog = NULL; 3735 goto out_put_prog; 3736 } 3737 3738 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3739 } 3740 3741 link = kzalloc_obj(*link, GFP_USER); 3742 if (!link) { 3743 err = -ENOMEM; 3744 goto out_put_prog; 3745 } 3746 bpf_tramp_link_init(&link->link, BPF_LINK_TYPE_TRACING, 3747 &bpf_tracing_link_lops, prog, attach_type, bpf_cookie); 3748 3749 if (prog->expected_attach_type == BPF_TRACE_FSESSION) { 3750 link->fexit.link = &link->link.link; 3751 link->fexit.cookie = bpf_cookie; 3752 } 3753 3754 mutex_lock(&prog->aux->dst_mutex); 3755 3756 /* There are a few possible cases here: 3757 * 3758 * - if prog->aux->dst_trampoline is set, the program was just loaded 3759 * and not yet attached to anything, so we can use the values stored 3760 * in prog->aux 3761 * 3762 * - if prog->aux->dst_trampoline is NULL, the program has already been 3763 * attached to a target and its initial target was cleared (below) 3764 * 3765 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3766 * target_btf_id using the link_create API. 3767 * 3768 * - if tgt_prog == NULL when this function was called using the old 3769 * raw_tracepoint_open API, and we need a target from prog->aux 3770 * 3771 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3772 * was detached and is going for re-attachment. 3773 * 3774 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3775 * are NULL, then program was already attached and user did not provide 3776 * tgt_prog_fd so we have no way to find out or create trampoline 3777 */ 3778 if (!prog->aux->dst_trampoline && !tgt_prog) { 3779 /* 3780 * Allow re-attach for TRACING and LSM programs. If it's 3781 * currently linked, bpf_trampoline_link_prog will fail. 3782 * EXT programs need to specify tgt_prog_fd, so they 3783 * re-attach in separate code path. 3784 */ 3785 if (prog->type != BPF_PROG_TYPE_TRACING && 3786 prog->type != BPF_PROG_TYPE_LSM) { 3787 err = -EINVAL; 3788 goto out_unlock; 3789 } 3790 /* We can allow re-attach only if we have valid attach_btf. */ 3791 if (!prog->aux->attach_btf) { 3792 err = -EINVAL; 3793 goto out_unlock; 3794 } 3795 btf_id = prog->aux->attach_btf_id; 3796 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3797 } 3798 3799 if (!prog->aux->dst_trampoline || 3800 (key && key != prog->aux->dst_trampoline->key)) { 3801 /* If there is no saved target, or the specified target is 3802 * different from the destination specified at load time, we 3803 * need a new trampoline and a check for compatibility 3804 */ 3805 struct bpf_attach_target_info tgt_info = {}; 3806 3807 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3808 &tgt_info); 3809 if (err) 3810 goto out_unlock; 3811 3812 if (tgt_info.tgt_mod) { 3813 module_put(prog->aux->mod); 3814 prog->aux->mod = tgt_info.tgt_mod; 3815 } 3816 3817 tr = bpf_trampoline_get(key, &tgt_info); 3818 if (!tr) { 3819 err = -ENOMEM; 3820 goto out_unlock; 3821 } 3822 } else { 3823 /* The caller didn't specify a target, or the target was the 3824 * same as the destination supplied during program load. This 3825 * means we can reuse the trampoline and reference from program 3826 * load time, and there is no need to allocate a new one. This 3827 * can only happen once for any program, as the saved values in 3828 * prog->aux are cleared below. 3829 */ 3830 tr = prog->aux->dst_trampoline; 3831 tgt_prog = prog->aux->dst_prog; 3832 } 3833 /* 3834 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true 3835 * freplace prog. Without this check, kprobe_write_ctx=true freplace 3836 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and 3837 * then modify the registers of the kprobe prog's target kernel 3838 * function. 3839 * 3840 * This also blocks the combination of uprobe+freplace, because it is 3841 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe 3842 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by 3843 * the target perf event flags in __perf_event_set_bpf_prog(). 3844 */ 3845 if (prog->type == BPF_PROG_TYPE_EXT && 3846 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) { 3847 err = -EINVAL; 3848 goto out_unlock; 3849 } 3850 3851 err = bpf_link_prime(&link->link.link, &link_primer); 3852 if (err) 3853 goto out_unlock; 3854 3855 err = bpf_trampoline_link_prog(&link->link.node, tr, tgt_prog); 3856 if (err) { 3857 bpf_link_cleanup(&link_primer); 3858 link = NULL; 3859 goto out_unlock; 3860 } 3861 3862 link->tgt_prog = tgt_prog; 3863 link->trampoline = tr; 3864 3865 /* Always clear the trampoline and target prog from prog->aux to make 3866 * sure the original attach destination is not kept alive after a 3867 * program is (re-)attached to another target. 3868 */ 3869 if (prog->aux->dst_prog && 3870 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3871 /* got extra prog ref from syscall, or attaching to different prog */ 3872 bpf_prog_put(prog->aux->dst_prog); 3873 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3874 /* we allocated a new trampoline, so free the old one */ 3875 bpf_trampoline_put(prog->aux->dst_trampoline); 3876 3877 prog->aux->dst_prog = NULL; 3878 prog->aux->dst_trampoline = NULL; 3879 mutex_unlock(&prog->aux->dst_mutex); 3880 3881 return bpf_link_settle(&link_primer); 3882 out_unlock: 3883 if (tr && tr != prog->aux->dst_trampoline) 3884 bpf_trampoline_put(tr); 3885 mutex_unlock(&prog->aux->dst_mutex); 3886 kfree(link); 3887 out_put_prog: 3888 if (tgt_prog_fd && tgt_prog) 3889 bpf_prog_put(tgt_prog); 3890 return err; 3891 } 3892 3893 static void bpf_raw_tp_link_release(struct bpf_link *link) 3894 { 3895 struct bpf_raw_tp_link *raw_tp = 3896 container_of(link, struct bpf_raw_tp_link, link); 3897 3898 bpf_probe_unregister(raw_tp->btp, raw_tp); 3899 bpf_put_raw_tracepoint(raw_tp->btp); 3900 } 3901 3902 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3903 { 3904 struct bpf_raw_tp_link *raw_tp = 3905 container_of(link, struct bpf_raw_tp_link, link); 3906 3907 kfree(raw_tp); 3908 } 3909 3910 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3911 struct seq_file *seq) 3912 { 3913 struct bpf_raw_tp_link *raw_tp_link = 3914 container_of(link, struct bpf_raw_tp_link, link); 3915 3916 seq_printf(seq, 3917 "tp_name:\t%s\n" 3918 "cookie:\t%llu\n", 3919 raw_tp_link->btp->tp->name, 3920 raw_tp_link->cookie); 3921 } 3922 3923 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3924 u32 len) 3925 { 3926 if (ulen >= len + 1) { 3927 if (copy_to_user(ubuf, buf, len + 1)) 3928 return -EFAULT; 3929 } else { 3930 char zero = '\0'; 3931 3932 if (copy_to_user(ubuf, buf, ulen - 1)) 3933 return -EFAULT; 3934 if (put_user(zero, ubuf + ulen - 1)) 3935 return -EFAULT; 3936 return -ENOSPC; 3937 } 3938 3939 return 0; 3940 } 3941 3942 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3943 struct bpf_link_info *info) 3944 { 3945 struct bpf_raw_tp_link *raw_tp_link = 3946 container_of(link, struct bpf_raw_tp_link, link); 3947 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3948 const char *tp_name = raw_tp_link->btp->tp->name; 3949 u32 ulen = info->raw_tracepoint.tp_name_len; 3950 size_t tp_len = strlen(tp_name); 3951 3952 if (!ulen ^ !ubuf) 3953 return -EINVAL; 3954 3955 info->raw_tracepoint.tp_name_len = tp_len + 1; 3956 info->raw_tracepoint.cookie = raw_tp_link->cookie; 3957 3958 if (!ubuf) 3959 return 0; 3960 3961 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3962 } 3963 3964 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3965 .release = bpf_raw_tp_link_release, 3966 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3967 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3968 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3969 }; 3970 3971 #ifdef CONFIG_PERF_EVENTS 3972 struct bpf_perf_link { 3973 struct bpf_link link; 3974 struct file *perf_file; 3975 }; 3976 3977 static void bpf_perf_link_release(struct bpf_link *link) 3978 { 3979 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3980 struct perf_event *event = perf_link->perf_file->private_data; 3981 3982 perf_event_free_bpf_prog(event); 3983 fput(perf_link->perf_file); 3984 } 3985 3986 static void bpf_perf_link_dealloc(struct bpf_link *link) 3987 { 3988 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3989 3990 kfree(perf_link); 3991 } 3992 3993 static int bpf_perf_link_fill_common(const struct perf_event *event, 3994 char __user *uname, u32 *ulenp, 3995 u64 *probe_offset, u64 *probe_addr, 3996 u32 *fd_type, unsigned long *missed) 3997 { 3998 const char *buf; 3999 u32 prog_id, ulen; 4000 size_t len; 4001 int err; 4002 4003 ulen = *ulenp; 4004 if (!ulen ^ !uname) 4005 return -EINVAL; 4006 4007 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 4008 probe_offset, probe_addr, missed); 4009 if (err) 4010 return err; 4011 4012 if (buf) { 4013 len = strlen(buf); 4014 *ulenp = len + 1; 4015 } else { 4016 *ulenp = 1; 4017 } 4018 if (!uname) 4019 return 0; 4020 4021 if (buf) { 4022 err = bpf_copy_to_user(uname, buf, ulen, len); 4023 if (err) 4024 return err; 4025 } else { 4026 char zero = '\0'; 4027 4028 if (put_user(zero, uname)) 4029 return -EFAULT; 4030 } 4031 return 0; 4032 } 4033 4034 #ifdef CONFIG_KPROBE_EVENTS 4035 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 4036 struct bpf_link_info *info) 4037 { 4038 unsigned long missed; 4039 char __user *uname; 4040 u64 addr, offset; 4041 u32 ulen, type; 4042 int err; 4043 4044 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 4045 ulen = info->perf_event.kprobe.name_len; 4046 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 4047 &type, &missed); 4048 if (err) 4049 return err; 4050 if (type == BPF_FD_TYPE_KRETPROBE) 4051 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 4052 else 4053 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 4054 info->perf_event.kprobe.name_len = ulen; 4055 info->perf_event.kprobe.offset = offset; 4056 info->perf_event.kprobe.missed = missed; 4057 if (!kallsyms_show_value(current_cred())) 4058 addr = 0; 4059 info->perf_event.kprobe.addr = addr; 4060 info->perf_event.kprobe.cookie = event->bpf_cookie; 4061 return 0; 4062 } 4063 4064 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, 4065 struct seq_file *seq) 4066 { 4067 const char *name; 4068 int err; 4069 u32 prog_id, type; 4070 u64 offset, addr; 4071 unsigned long missed; 4072 4073 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4074 &offset, &addr, &missed); 4075 if (err) 4076 return; 4077 4078 seq_printf(seq, 4079 "name:\t%s\n" 4080 "offset:\t%#llx\n" 4081 "missed:\t%lu\n" 4082 "addr:\t%#llx\n" 4083 "event_type:\t%s\n" 4084 "cookie:\t%llu\n", 4085 name, offset, missed, addr, 4086 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", 4087 event->bpf_cookie); 4088 } 4089 #endif 4090 4091 #ifdef CONFIG_UPROBE_EVENTS 4092 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 4093 struct bpf_link_info *info) 4094 { 4095 u64 ref_ctr_offset, offset; 4096 char __user *uname; 4097 u32 ulen, type; 4098 int err; 4099 4100 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 4101 ulen = info->perf_event.uprobe.name_len; 4102 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, 4103 &type, NULL); 4104 if (err) 4105 return err; 4106 4107 if (type == BPF_FD_TYPE_URETPROBE) 4108 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 4109 else 4110 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 4111 info->perf_event.uprobe.name_len = ulen; 4112 info->perf_event.uprobe.offset = offset; 4113 info->perf_event.uprobe.cookie = event->bpf_cookie; 4114 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; 4115 return 0; 4116 } 4117 4118 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, 4119 struct seq_file *seq) 4120 { 4121 const char *name; 4122 int err; 4123 u32 prog_id, type; 4124 u64 offset, ref_ctr_offset; 4125 unsigned long missed; 4126 4127 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4128 &offset, &ref_ctr_offset, &missed); 4129 if (err) 4130 return; 4131 4132 seq_printf(seq, 4133 "name:\t%s\n" 4134 "offset:\t%#llx\n" 4135 "ref_ctr_offset:\t%#llx\n" 4136 "event_type:\t%s\n" 4137 "cookie:\t%llu\n", 4138 name, offset, ref_ctr_offset, 4139 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", 4140 event->bpf_cookie); 4141 } 4142 #endif 4143 4144 static int bpf_perf_link_fill_probe(const struct perf_event *event, 4145 struct bpf_link_info *info) 4146 { 4147 #ifdef CONFIG_KPROBE_EVENTS 4148 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4149 return bpf_perf_link_fill_kprobe(event, info); 4150 #endif 4151 #ifdef CONFIG_UPROBE_EVENTS 4152 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4153 return bpf_perf_link_fill_uprobe(event, info); 4154 #endif 4155 return -EOPNOTSUPP; 4156 } 4157 4158 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 4159 struct bpf_link_info *info) 4160 { 4161 char __user *uname; 4162 u32 ulen; 4163 int err; 4164 4165 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 4166 ulen = info->perf_event.tracepoint.name_len; 4167 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 4168 if (err) 4169 return err; 4170 4171 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 4172 info->perf_event.tracepoint.name_len = ulen; 4173 info->perf_event.tracepoint.cookie = event->bpf_cookie; 4174 return 0; 4175 } 4176 4177 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 4178 struct bpf_link_info *info) 4179 { 4180 info->perf_event.event.type = event->attr.type; 4181 info->perf_event.event.config = event->attr.config; 4182 info->perf_event.event.cookie = event->bpf_cookie; 4183 info->perf_event.type = BPF_PERF_EVENT_EVENT; 4184 return 0; 4185 } 4186 4187 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 4188 struct bpf_link_info *info) 4189 { 4190 struct bpf_perf_link *perf_link; 4191 const struct perf_event *event; 4192 4193 perf_link = container_of(link, struct bpf_perf_link, link); 4194 event = perf_get_event(perf_link->perf_file); 4195 if (IS_ERR(event)) 4196 return PTR_ERR(event); 4197 4198 switch (event->prog->type) { 4199 case BPF_PROG_TYPE_PERF_EVENT: 4200 return bpf_perf_link_fill_perf_event(event, info); 4201 case BPF_PROG_TYPE_TRACEPOINT: 4202 return bpf_perf_link_fill_tracepoint(event, info); 4203 case BPF_PROG_TYPE_KPROBE: 4204 return bpf_perf_link_fill_probe(event, info); 4205 default: 4206 return -EOPNOTSUPP; 4207 } 4208 } 4209 4210 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, 4211 struct seq_file *seq) 4212 { 4213 seq_printf(seq, 4214 "type:\t%u\n" 4215 "config:\t%llu\n" 4216 "event_type:\t%s\n" 4217 "cookie:\t%llu\n", 4218 event->attr.type, event->attr.config, 4219 "event", event->bpf_cookie); 4220 } 4221 4222 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, 4223 struct seq_file *seq) 4224 { 4225 int err; 4226 const char *name; 4227 u32 prog_id; 4228 4229 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, 4230 NULL, NULL); 4231 if (err) 4232 return; 4233 4234 seq_printf(seq, 4235 "tp_name:\t%s\n" 4236 "event_type:\t%s\n" 4237 "cookie:\t%llu\n", 4238 name, "tracepoint", event->bpf_cookie); 4239 } 4240 4241 static void bpf_probe_link_show_fdinfo(const struct perf_event *event, 4242 struct seq_file *seq) 4243 { 4244 #ifdef CONFIG_KPROBE_EVENTS 4245 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4246 return bpf_perf_link_fdinfo_kprobe(event, seq); 4247 #endif 4248 4249 #ifdef CONFIG_UPROBE_EVENTS 4250 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4251 return bpf_perf_link_fdinfo_uprobe(event, seq); 4252 #endif 4253 } 4254 4255 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, 4256 struct seq_file *seq) 4257 { 4258 struct bpf_perf_link *perf_link; 4259 const struct perf_event *event; 4260 4261 perf_link = container_of(link, struct bpf_perf_link, link); 4262 event = perf_get_event(perf_link->perf_file); 4263 if (IS_ERR(event)) 4264 return; 4265 4266 switch (event->prog->type) { 4267 case BPF_PROG_TYPE_PERF_EVENT: 4268 return bpf_perf_event_link_show_fdinfo(event, seq); 4269 case BPF_PROG_TYPE_TRACEPOINT: 4270 return bpf_tracepoint_link_show_fdinfo(event, seq); 4271 case BPF_PROG_TYPE_KPROBE: 4272 return bpf_probe_link_show_fdinfo(event, seq); 4273 default: 4274 return; 4275 } 4276 } 4277 4278 static const struct bpf_link_ops bpf_perf_link_lops = { 4279 .release = bpf_perf_link_release, 4280 .dealloc = bpf_perf_link_dealloc, 4281 .fill_link_info = bpf_perf_link_fill_link_info, 4282 .show_fdinfo = bpf_perf_link_show_fdinfo, 4283 }; 4284 4285 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4286 { 4287 struct bpf_link_primer link_primer; 4288 struct bpf_perf_link *link; 4289 struct perf_event *event; 4290 struct file *perf_file; 4291 int err; 4292 4293 if (attr->link_create.flags) 4294 return -EINVAL; 4295 4296 perf_file = perf_event_get(attr->link_create.target_fd); 4297 if (IS_ERR(perf_file)) 4298 return PTR_ERR(perf_file); 4299 4300 link = kzalloc_obj(*link, GFP_USER); 4301 if (!link) { 4302 err = -ENOMEM; 4303 goto out_put_file; 4304 } 4305 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, 4306 attr->link_create.attach_type); 4307 link->perf_file = perf_file; 4308 4309 err = bpf_link_prime(&link->link, &link_primer); 4310 if (err) { 4311 kfree(link); 4312 goto out_put_file; 4313 } 4314 4315 event = perf_file->private_data; 4316 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 4317 if (err) { 4318 bpf_link_cleanup(&link_primer); 4319 goto out_put_file; 4320 } 4321 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 4322 bpf_prog_inc(prog); 4323 4324 return bpf_link_settle(&link_primer); 4325 4326 out_put_file: 4327 fput(perf_file); 4328 return err; 4329 } 4330 #else 4331 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4332 { 4333 return -EOPNOTSUPP; 4334 } 4335 #endif /* CONFIG_PERF_EVENTS */ 4336 4337 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 4338 const char __user *user_tp_name, u64 cookie, 4339 enum bpf_attach_type attach_type) 4340 { 4341 struct bpf_link_primer link_primer; 4342 struct bpf_raw_tp_link *link; 4343 struct bpf_raw_event_map *btp; 4344 const char *tp_name; 4345 char buf[128]; 4346 int err; 4347 4348 switch (prog->type) { 4349 case BPF_PROG_TYPE_TRACING: 4350 case BPF_PROG_TYPE_EXT: 4351 case BPF_PROG_TYPE_LSM: 4352 if (user_tp_name) 4353 /* The attach point for this category of programs 4354 * should be specified via btf_id during program load. 4355 */ 4356 return -EINVAL; 4357 if (prog->type == BPF_PROG_TYPE_TRACING && 4358 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 4359 tp_name = prog->aux->attach_func_name; 4360 break; 4361 } 4362 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); 4363 case BPF_PROG_TYPE_RAW_TRACEPOINT: 4364 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 4365 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 4366 return -EFAULT; 4367 buf[sizeof(buf) - 1] = 0; 4368 tp_name = buf; 4369 break; 4370 default: 4371 return -EINVAL; 4372 } 4373 4374 btp = bpf_get_raw_tracepoint(tp_name); 4375 if (!btp) 4376 return -ENOENT; 4377 4378 if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) { 4379 bpf_put_raw_tracepoint(btp); 4380 return -EINVAL; 4381 } 4382 4383 link = kzalloc_obj(*link, GFP_USER); 4384 if (!link) { 4385 err = -ENOMEM; 4386 goto out_put_btp; 4387 } 4388 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 4389 &bpf_raw_tp_link_lops, prog, attach_type, 4390 tracepoint_is_faultable(btp->tp)); 4391 link->btp = btp; 4392 link->cookie = cookie; 4393 4394 err = bpf_link_prime(&link->link, &link_primer); 4395 if (err) { 4396 kfree(link); 4397 goto out_put_btp; 4398 } 4399 4400 err = bpf_probe_register(link->btp, link); 4401 if (err) { 4402 bpf_link_cleanup(&link_primer); 4403 goto out_put_btp; 4404 } 4405 4406 return bpf_link_settle(&link_primer); 4407 4408 out_put_btp: 4409 bpf_put_raw_tracepoint(btp); 4410 return err; 4411 } 4412 4413 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 4414 4415 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4416 { 4417 struct bpf_prog *prog; 4418 void __user *tp_name; 4419 __u64 cookie; 4420 int fd; 4421 4422 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4423 return -EINVAL; 4424 4425 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4426 if (IS_ERR(prog)) 4427 return PTR_ERR(prog); 4428 4429 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4430 cookie = attr->raw_tracepoint.cookie; 4431 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); 4432 if (fd < 0) 4433 bpf_prog_put(prog); 4434 return fd; 4435 } 4436 4437 static enum bpf_prog_type 4438 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4439 { 4440 switch (attach_type) { 4441 case BPF_CGROUP_INET_INGRESS: 4442 case BPF_CGROUP_INET_EGRESS: 4443 return BPF_PROG_TYPE_CGROUP_SKB; 4444 case BPF_CGROUP_INET_SOCK_CREATE: 4445 case BPF_CGROUP_INET_SOCK_RELEASE: 4446 case BPF_CGROUP_INET4_POST_BIND: 4447 case BPF_CGROUP_INET6_POST_BIND: 4448 return BPF_PROG_TYPE_CGROUP_SOCK; 4449 case BPF_CGROUP_INET4_BIND: 4450 case BPF_CGROUP_INET6_BIND: 4451 case BPF_CGROUP_INET4_CONNECT: 4452 case BPF_CGROUP_INET6_CONNECT: 4453 case BPF_CGROUP_UNIX_CONNECT: 4454 case BPF_CGROUP_INET4_GETPEERNAME: 4455 case BPF_CGROUP_INET6_GETPEERNAME: 4456 case BPF_CGROUP_UNIX_GETPEERNAME: 4457 case BPF_CGROUP_INET4_GETSOCKNAME: 4458 case BPF_CGROUP_INET6_GETSOCKNAME: 4459 case BPF_CGROUP_UNIX_GETSOCKNAME: 4460 case BPF_CGROUP_UDP4_SENDMSG: 4461 case BPF_CGROUP_UDP6_SENDMSG: 4462 case BPF_CGROUP_UNIX_SENDMSG: 4463 case BPF_CGROUP_UDP4_RECVMSG: 4464 case BPF_CGROUP_UDP6_RECVMSG: 4465 case BPF_CGROUP_UNIX_RECVMSG: 4466 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4467 case BPF_CGROUP_SOCK_OPS: 4468 return BPF_PROG_TYPE_SOCK_OPS; 4469 case BPF_CGROUP_DEVICE: 4470 return BPF_PROG_TYPE_CGROUP_DEVICE; 4471 case BPF_SK_MSG_VERDICT: 4472 return BPF_PROG_TYPE_SK_MSG; 4473 case BPF_SK_SKB_STREAM_PARSER: 4474 case BPF_SK_SKB_STREAM_VERDICT: 4475 case BPF_SK_SKB_VERDICT: 4476 return BPF_PROG_TYPE_SK_SKB; 4477 case BPF_LIRC_MODE2: 4478 return BPF_PROG_TYPE_LIRC_MODE2; 4479 case BPF_FLOW_DISSECTOR: 4480 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4481 case BPF_CGROUP_SYSCTL: 4482 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4483 case BPF_CGROUP_GETSOCKOPT: 4484 case BPF_CGROUP_SETSOCKOPT: 4485 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4486 case BPF_TRACE_ITER: 4487 case BPF_TRACE_RAW_TP: 4488 case BPF_TRACE_FENTRY: 4489 case BPF_TRACE_FEXIT: 4490 case BPF_TRACE_FSESSION: 4491 case BPF_TRACE_FSESSION_MULTI: 4492 case BPF_TRACE_FENTRY_MULTI: 4493 case BPF_TRACE_FEXIT_MULTI: 4494 case BPF_MODIFY_RETURN: 4495 return BPF_PROG_TYPE_TRACING; 4496 case BPF_LSM_MAC: 4497 return BPF_PROG_TYPE_LSM; 4498 case BPF_SK_LOOKUP: 4499 return BPF_PROG_TYPE_SK_LOOKUP; 4500 case BPF_XDP: 4501 return BPF_PROG_TYPE_XDP; 4502 case BPF_LSM_CGROUP: 4503 return BPF_PROG_TYPE_LSM; 4504 case BPF_TCX_INGRESS: 4505 case BPF_TCX_EGRESS: 4506 case BPF_NETKIT_PRIMARY: 4507 case BPF_NETKIT_PEER: 4508 return BPF_PROG_TYPE_SCHED_CLS; 4509 default: 4510 return BPF_PROG_TYPE_UNSPEC; 4511 } 4512 } 4513 4514 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4515 enum bpf_attach_type attach_type) 4516 { 4517 enum bpf_prog_type ptype; 4518 4519 switch (prog->type) { 4520 case BPF_PROG_TYPE_CGROUP_SOCK: 4521 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4522 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4523 case BPF_PROG_TYPE_SK_LOOKUP: 4524 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4525 case BPF_PROG_TYPE_CGROUP_SKB: 4526 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4527 /* cg-skb progs can be loaded by unpriv user. 4528 * check permissions at attach time. 4529 */ 4530 return -EPERM; 4531 4532 ptype = attach_type_to_prog_type(attach_type); 4533 if (prog->type != ptype) 4534 return -EINVAL; 4535 4536 return prog->enforce_expected_attach_type && 4537 prog->expected_attach_type != attach_type ? 4538 -EINVAL : 0; 4539 case BPF_PROG_TYPE_EXT: 4540 return 0; 4541 case BPF_PROG_TYPE_NETFILTER: 4542 if (attach_type != BPF_NETFILTER) 4543 return -EINVAL; 4544 return 0; 4545 case BPF_PROG_TYPE_PERF_EVENT: 4546 case BPF_PROG_TYPE_TRACEPOINT: 4547 if (attach_type != BPF_PERF_EVENT) 4548 return -EINVAL; 4549 return 0; 4550 case BPF_PROG_TYPE_KPROBE: 4551 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4552 attach_type != BPF_TRACE_KPROBE_MULTI) 4553 return -EINVAL; 4554 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4555 attach_type != BPF_TRACE_KPROBE_SESSION) 4556 return -EINVAL; 4557 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4558 attach_type != BPF_TRACE_UPROBE_MULTI) 4559 return -EINVAL; 4560 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4561 attach_type != BPF_TRACE_UPROBE_SESSION) 4562 return -EINVAL; 4563 if (attach_type != BPF_PERF_EVENT && 4564 attach_type != BPF_TRACE_KPROBE_MULTI && 4565 attach_type != BPF_TRACE_KPROBE_SESSION && 4566 attach_type != BPF_TRACE_UPROBE_MULTI && 4567 attach_type != BPF_TRACE_UPROBE_SESSION) 4568 return -EINVAL; 4569 return 0; 4570 case BPF_PROG_TYPE_SCHED_CLS: 4571 if (attach_type != BPF_TCX_INGRESS && 4572 attach_type != BPF_TCX_EGRESS && 4573 attach_type != BPF_NETKIT_PRIMARY && 4574 attach_type != BPF_NETKIT_PEER) 4575 return -EINVAL; 4576 return 0; 4577 default: 4578 ptype = attach_type_to_prog_type(attach_type); 4579 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4580 return -EINVAL; 4581 return 0; 4582 } 4583 } 4584 4585 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, 4586 bool check_atype) 4587 { 4588 switch (ptype) { 4589 case BPF_PROG_TYPE_CGROUP_DEVICE: 4590 case BPF_PROG_TYPE_CGROUP_SKB: 4591 case BPF_PROG_TYPE_CGROUP_SOCK: 4592 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4593 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4594 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4595 case BPF_PROG_TYPE_SOCK_OPS: 4596 return true; 4597 case BPF_PROG_TYPE_LSM: 4598 return check_atype ? atype == BPF_LSM_CGROUP : true; 4599 default: 4600 return false; 4601 } 4602 } 4603 4604 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4605 4606 #define BPF_F_ATTACH_MASK_BASE \ 4607 (BPF_F_ALLOW_OVERRIDE | \ 4608 BPF_F_ALLOW_MULTI | \ 4609 BPF_F_REPLACE | \ 4610 BPF_F_PREORDER) 4611 4612 #define BPF_F_ATTACH_MASK_MPROG \ 4613 (BPF_F_REPLACE | \ 4614 BPF_F_BEFORE | \ 4615 BPF_F_AFTER | \ 4616 BPF_F_ID | \ 4617 BPF_F_LINK) 4618 4619 static int bpf_prog_attach(const union bpf_attr *attr) 4620 { 4621 enum bpf_prog_type ptype; 4622 struct bpf_prog *prog; 4623 int ret; 4624 4625 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4626 return -EINVAL; 4627 4628 ptype = attach_type_to_prog_type(attr->attach_type); 4629 if (ptype == BPF_PROG_TYPE_UNSPEC) 4630 return -EINVAL; 4631 if (bpf_mprog_supported(ptype)) { 4632 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4633 return -EINVAL; 4634 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4635 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) 4636 return -EINVAL; 4637 } else { 4638 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4639 return -EINVAL; 4640 if (attr->relative_fd || 4641 attr->expected_revision) 4642 return -EINVAL; 4643 } 4644 4645 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4646 if (IS_ERR(prog)) 4647 return PTR_ERR(prog); 4648 4649 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4650 bpf_prog_put(prog); 4651 return -EINVAL; 4652 } 4653 4654 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { 4655 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4656 goto out; 4657 } 4658 4659 switch (ptype) { 4660 case BPF_PROG_TYPE_SK_SKB: 4661 case BPF_PROG_TYPE_SK_MSG: 4662 ret = sock_map_get_from_fd(attr, prog); 4663 break; 4664 case BPF_PROG_TYPE_LIRC_MODE2: 4665 ret = lirc_prog_attach(attr, prog); 4666 break; 4667 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4668 ret = netns_bpf_prog_attach(attr, prog); 4669 break; 4670 case BPF_PROG_TYPE_SCHED_CLS: 4671 if (attr->attach_type == BPF_TCX_INGRESS || 4672 attr->attach_type == BPF_TCX_EGRESS) 4673 ret = tcx_prog_attach(attr, prog); 4674 else 4675 ret = netkit_prog_attach(attr, prog); 4676 break; 4677 default: 4678 ret = -EINVAL; 4679 } 4680 out: 4681 if (ret) 4682 bpf_prog_put(prog); 4683 return ret; 4684 } 4685 4686 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4687 4688 static int bpf_prog_detach(const union bpf_attr *attr) 4689 { 4690 struct bpf_prog *prog = NULL; 4691 enum bpf_prog_type ptype; 4692 int ret; 4693 4694 if (CHECK_ATTR(BPF_PROG_DETACH)) 4695 return -EINVAL; 4696 4697 ptype = attach_type_to_prog_type(attr->attach_type); 4698 if (bpf_mprog_supported(ptype)) { 4699 if (ptype == BPF_PROG_TYPE_UNSPEC) 4700 return -EINVAL; 4701 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4702 return -EINVAL; 4703 if (attr->attach_bpf_fd) { 4704 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4705 if (IS_ERR(prog)) 4706 return PTR_ERR(prog); 4707 } else if (!bpf_mprog_detach_empty(ptype)) { 4708 return -EPERM; 4709 } 4710 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4711 if (attr->attach_flags || attr->relative_fd) 4712 return -EINVAL; 4713 } else if (attr->attach_flags || 4714 attr->relative_fd || 4715 attr->expected_revision) { 4716 return -EINVAL; 4717 } 4718 4719 switch (ptype) { 4720 case BPF_PROG_TYPE_SK_MSG: 4721 case BPF_PROG_TYPE_SK_SKB: 4722 ret = sock_map_prog_detach(attr, ptype); 4723 break; 4724 case BPF_PROG_TYPE_LIRC_MODE2: 4725 ret = lirc_prog_detach(attr); 4726 break; 4727 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4728 ret = netns_bpf_prog_detach(attr, ptype); 4729 break; 4730 case BPF_PROG_TYPE_CGROUP_DEVICE: 4731 case BPF_PROG_TYPE_CGROUP_SKB: 4732 case BPF_PROG_TYPE_CGROUP_SOCK: 4733 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4734 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4735 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4736 case BPF_PROG_TYPE_SOCK_OPS: 4737 case BPF_PROG_TYPE_LSM: 4738 ret = cgroup_bpf_prog_detach(attr, ptype); 4739 break; 4740 case BPF_PROG_TYPE_SCHED_CLS: 4741 if (attr->attach_type == BPF_TCX_INGRESS || 4742 attr->attach_type == BPF_TCX_EGRESS) 4743 ret = tcx_prog_detach(attr, prog); 4744 else 4745 ret = netkit_prog_detach(attr, prog); 4746 break; 4747 default: 4748 ret = -EINVAL; 4749 } 4750 4751 if (prog) 4752 bpf_prog_put(prog); 4753 return ret; 4754 } 4755 4756 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4757 4758 static int bpf_prog_query(const union bpf_attr *attr, 4759 union bpf_attr __user *uattr, u32 uattr_size) 4760 { 4761 if (!bpf_net_capable()) 4762 return -EPERM; 4763 if (CHECK_ATTR(BPF_PROG_QUERY)) 4764 return -EINVAL; 4765 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4766 return -EINVAL; 4767 4768 switch (attr->query.attach_type) { 4769 case BPF_CGROUP_INET_INGRESS: 4770 case BPF_CGROUP_INET_EGRESS: 4771 case BPF_CGROUP_INET_SOCK_CREATE: 4772 case BPF_CGROUP_INET_SOCK_RELEASE: 4773 case BPF_CGROUP_INET4_BIND: 4774 case BPF_CGROUP_INET6_BIND: 4775 case BPF_CGROUP_INET4_POST_BIND: 4776 case BPF_CGROUP_INET6_POST_BIND: 4777 case BPF_CGROUP_INET4_CONNECT: 4778 case BPF_CGROUP_INET6_CONNECT: 4779 case BPF_CGROUP_UNIX_CONNECT: 4780 case BPF_CGROUP_INET4_GETPEERNAME: 4781 case BPF_CGROUP_INET6_GETPEERNAME: 4782 case BPF_CGROUP_UNIX_GETPEERNAME: 4783 case BPF_CGROUP_INET4_GETSOCKNAME: 4784 case BPF_CGROUP_INET6_GETSOCKNAME: 4785 case BPF_CGROUP_UNIX_GETSOCKNAME: 4786 case BPF_CGROUP_UDP4_SENDMSG: 4787 case BPF_CGROUP_UDP6_SENDMSG: 4788 case BPF_CGROUP_UNIX_SENDMSG: 4789 case BPF_CGROUP_UDP4_RECVMSG: 4790 case BPF_CGROUP_UDP6_RECVMSG: 4791 case BPF_CGROUP_UNIX_RECVMSG: 4792 case BPF_CGROUP_SOCK_OPS: 4793 case BPF_CGROUP_DEVICE: 4794 case BPF_CGROUP_SYSCTL: 4795 case BPF_CGROUP_GETSOCKOPT: 4796 case BPF_CGROUP_SETSOCKOPT: 4797 case BPF_LSM_CGROUP: 4798 case BPF_STRUCT_OPS: 4799 return cgroup_bpf_prog_query(attr, uattr, uattr_size); 4800 case BPF_LIRC_MODE2: 4801 return lirc_prog_query(attr, uattr); 4802 case BPF_FLOW_DISSECTOR: 4803 case BPF_SK_LOOKUP: 4804 return netns_bpf_prog_query(attr, uattr); 4805 case BPF_SK_SKB_STREAM_PARSER: 4806 case BPF_SK_SKB_STREAM_VERDICT: 4807 case BPF_SK_MSG_VERDICT: 4808 case BPF_SK_SKB_VERDICT: 4809 return sock_map_bpf_prog_query(attr, uattr); 4810 case BPF_TCX_INGRESS: 4811 case BPF_TCX_EGRESS: 4812 return tcx_prog_query(attr, uattr); 4813 case BPF_NETKIT_PRIMARY: 4814 case BPF_NETKIT_PEER: 4815 return netkit_prog_query(attr, uattr); 4816 default: 4817 return -EINVAL; 4818 } 4819 } 4820 4821 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4822 4823 static int bpf_prog_test_run(const union bpf_attr *attr, 4824 union bpf_attr __user *uattr) 4825 { 4826 struct bpf_prog *prog; 4827 int ret = -ENOTSUPP; 4828 4829 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4830 return -EINVAL; 4831 4832 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4833 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4834 return -EINVAL; 4835 4836 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4837 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4838 return -EINVAL; 4839 4840 prog = bpf_prog_get(attr->test.prog_fd); 4841 if (IS_ERR(prog)) 4842 return PTR_ERR(prog); 4843 4844 if (prog->aux->ops->test_run) 4845 ret = prog->aux->ops->test_run(prog, attr, uattr); 4846 4847 bpf_prog_put(prog); 4848 return ret; 4849 } 4850 4851 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4852 4853 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4854 union bpf_attr __user *uattr, 4855 struct idr *idr, 4856 spinlock_t *lock) 4857 { 4858 u32 next_id = attr->start_id; 4859 int err = 0; 4860 4861 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4862 return -EINVAL; 4863 4864 if (!capable(CAP_SYS_ADMIN)) 4865 return -EPERM; 4866 4867 next_id++; 4868 spin_lock_bh(lock); 4869 if (!idr_get_next(idr, &next_id)) 4870 err = -ENOENT; 4871 spin_unlock_bh(lock); 4872 4873 if (!err) 4874 err = put_user(next_id, &uattr->next_id); 4875 4876 return err; 4877 } 4878 4879 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4880 { 4881 struct bpf_map *map; 4882 4883 spin_lock_bh(&map_idr_lock); 4884 again: 4885 map = idr_get_next(&map_idr, id); 4886 if (map) { 4887 map = __bpf_map_inc_not_zero(map, false); 4888 if (IS_ERR(map)) { 4889 (*id)++; 4890 goto again; 4891 } 4892 } 4893 spin_unlock_bh(&map_idr_lock); 4894 4895 return map; 4896 } 4897 4898 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4899 { 4900 struct bpf_prog *prog; 4901 4902 spin_lock_bh(&prog_idr_lock); 4903 again: 4904 prog = idr_get_next(&prog_idr, id); 4905 if (prog) { 4906 prog = bpf_prog_inc_not_zero(prog); 4907 if (IS_ERR(prog)) { 4908 (*id)++; 4909 goto again; 4910 } 4911 } 4912 spin_unlock_bh(&prog_idr_lock); 4913 4914 return prog; 4915 } 4916 4917 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4918 4919 struct bpf_prog *bpf_prog_by_id(u32 id) 4920 { 4921 struct bpf_prog *prog; 4922 4923 if (!id) 4924 return ERR_PTR(-ENOENT); 4925 4926 spin_lock_bh(&prog_idr_lock); 4927 prog = idr_find(&prog_idr, id); 4928 if (prog) 4929 prog = bpf_prog_inc_not_zero(prog); 4930 else 4931 prog = ERR_PTR(-ENOENT); 4932 spin_unlock_bh(&prog_idr_lock); 4933 return prog; 4934 } 4935 4936 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4937 { 4938 struct bpf_prog *prog; 4939 u32 id = attr->prog_id; 4940 int fd; 4941 4942 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4943 return -EINVAL; 4944 4945 if (!capable(CAP_SYS_ADMIN)) 4946 return -EPERM; 4947 4948 prog = bpf_prog_by_id(id); 4949 if (IS_ERR(prog)) 4950 return PTR_ERR(prog); 4951 4952 fd = bpf_prog_new_fd(prog); 4953 if (fd < 0) 4954 bpf_prog_put(prog); 4955 4956 return fd; 4957 } 4958 4959 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4960 4961 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4962 { 4963 struct bpf_map *map; 4964 u32 id = attr->map_id; 4965 int f_flags; 4966 int fd; 4967 4968 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4969 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4970 return -EINVAL; 4971 4972 if (!capable(CAP_SYS_ADMIN)) 4973 return -EPERM; 4974 4975 f_flags = bpf_get_file_flag(attr->open_flags); 4976 if (f_flags < 0) 4977 return f_flags; 4978 4979 spin_lock_bh(&map_idr_lock); 4980 map = idr_find(&map_idr, id); 4981 if (map) 4982 map = __bpf_map_inc_not_zero(map, true); 4983 else 4984 map = ERR_PTR(-ENOENT); 4985 spin_unlock_bh(&map_idr_lock); 4986 4987 if (IS_ERR(map)) 4988 return PTR_ERR(map); 4989 4990 fd = bpf_map_new_fd(map, f_flags); 4991 if (fd < 0) 4992 bpf_map_put_with_uref(map); 4993 4994 return fd; 4995 } 4996 4997 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4998 unsigned long addr, u32 *off, 4999 u32 *type) 5000 { 5001 const struct bpf_map *map; 5002 int i; 5003 5004 mutex_lock(&prog->aux->used_maps_mutex); 5005 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 5006 map = prog->aux->used_maps[i]; 5007 if (map == (void *)addr) { 5008 *type = BPF_PSEUDO_MAP_FD; 5009 goto out; 5010 } 5011 if (!map->ops->map_direct_value_meta) 5012 continue; 5013 if (!map->ops->map_direct_value_meta(map, addr, off)) { 5014 *type = BPF_PSEUDO_MAP_VALUE; 5015 goto out; 5016 } 5017 } 5018 map = NULL; 5019 5020 out: 5021 mutex_unlock(&prog->aux->used_maps_mutex); 5022 return map; 5023 } 5024 5025 static void prepare_dump_pseudo_call(struct bpf_insn *insn) 5026 { 5027 s32 call_off = insn->imm; 5028 5029 /* 5030 * BPF_CALL_ARGS only exists for interpreter fallback. 5031 * 1. For interpreter (BPF_CALL_ARGS): insn->off is the index of 5032 * interpreters_args array, so here using bpf_call_args_imm() 5033 * to get the real address offset. 5034 * 2. For JIT (BPF_CALL): insn->off is the subprog id. 5035 */ 5036 if (insn->code == (BPF_JMP | BPF_CALL_ARGS)) 5037 insn->imm = bpf_call_args_imm(insn->off); 5038 else 5039 insn->imm = insn->off; 5040 5041 /* Avoid dumping a truncated and misleading pc-relative offset. */ 5042 if (call_off > S16_MAX || call_off < S16_MIN) 5043 insn->off = 0; 5044 else 5045 insn->off = call_off; 5046 } 5047 5048 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 5049 const struct cred *f_cred) 5050 { 5051 const struct bpf_map *map; 5052 struct bpf_insn *insns; 5053 u32 off, type; 5054 u64 imm; 5055 u8 code; 5056 int i; 5057 5058 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 5059 GFP_USER); 5060 if (!insns) 5061 return insns; 5062 5063 for (i = 0; i < prog->len; i++) { 5064 code = insns[i].code; 5065 5066 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 5067 insns[i].code = BPF_JMP | BPF_CALL; 5068 insns[i].imm = BPF_FUNC_tail_call; 5069 /* fall-through */ 5070 } 5071 if (code == (BPF_JMP | BPF_CALL) || 5072 code == (BPF_JMP | BPF_CALL_ARGS)) { 5073 /* Restore the legacy xlated dump layout. */ 5074 if (insns[i].src_reg == BPF_PSEUDO_CALL) 5075 prepare_dump_pseudo_call(&insns[i]); 5076 if (code == (BPF_JMP | BPF_CALL_ARGS)) 5077 insns[i].code = BPF_JMP | BPF_CALL; 5078 if (!bpf_dump_raw_ok(f_cred)) 5079 insns[i].imm = 0; 5080 continue; 5081 } 5082 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 5083 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 5084 continue; 5085 } 5086 5087 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 5088 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 5089 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 5090 continue; 5091 } 5092 5093 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 5094 continue; 5095 5096 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 5097 map = bpf_map_from_imm(prog, imm, &off, &type); 5098 if (map) { 5099 insns[i].src_reg = type; 5100 insns[i].imm = map->id; 5101 insns[i + 1].imm = off; 5102 continue; 5103 } 5104 } 5105 5106 return insns; 5107 } 5108 5109 static int set_info_rec_size(struct bpf_prog_info *info) 5110 { 5111 /* 5112 * Ensure info.*_rec_size is the same as kernel expected size 5113 * 5114 * or 5115 * 5116 * Only allow zero *_rec_size if both _rec_size and _cnt are 5117 * zero. In this case, the kernel will set the expected 5118 * _rec_size back to the info. 5119 */ 5120 5121 if ((info->nr_func_info || info->func_info_rec_size) && 5122 info->func_info_rec_size != sizeof(struct bpf_func_info)) 5123 return -EINVAL; 5124 5125 if ((info->nr_line_info || info->line_info_rec_size) && 5126 info->line_info_rec_size != sizeof(struct bpf_line_info)) 5127 return -EINVAL; 5128 5129 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 5130 info->jited_line_info_rec_size != sizeof(__u64)) 5131 return -EINVAL; 5132 5133 info->func_info_rec_size = sizeof(struct bpf_func_info); 5134 info->line_info_rec_size = sizeof(struct bpf_line_info); 5135 info->jited_line_info_rec_size = sizeof(__u64); 5136 5137 return 0; 5138 } 5139 5140 static int bpf_prog_get_info_by_fd(struct file *file, 5141 struct bpf_prog *prog, 5142 const union bpf_attr *attr, 5143 union bpf_attr __user *uattr) 5144 { 5145 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5146 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 5147 struct bpf_prog_info info; 5148 u32 info_len = attr->info.info_len; 5149 struct bpf_prog_kstats stats; 5150 char __user *uinsns; 5151 u32 ulen, len; 5152 int err; 5153 5154 len = offsetofend(struct bpf_prog_info, attach_btf_id); 5155 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len); 5156 if (err) 5157 return err; 5158 info_len = min_t(u32, sizeof(info), info_len); 5159 5160 memset(&info, 0, sizeof(info)); 5161 if (copy_from_user(&info, uinfo, info_len)) 5162 return -EFAULT; 5163 5164 info.type = prog->type; 5165 info.id = prog->aux->id; 5166 info.load_time = prog->aux->load_time; 5167 info.created_by_uid = from_kuid_munged(current_user_ns(), 5168 prog->aux->user->uid); 5169 info.gpl_compatible = prog->gpl_compatible; 5170 5171 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 5172 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 5173 5174 mutex_lock(&prog->aux->used_maps_mutex); 5175 ulen = info.nr_map_ids; 5176 info.nr_map_ids = prog->aux->used_map_cnt; 5177 ulen = min_t(u32, info.nr_map_ids, ulen); 5178 if (ulen) { 5179 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 5180 u32 i; 5181 5182 for (i = 0; i < ulen; i++) 5183 if (put_user(prog->aux->used_maps[i]->id, 5184 &user_map_ids[i])) { 5185 mutex_unlock(&prog->aux->used_maps_mutex); 5186 return -EFAULT; 5187 } 5188 } 5189 mutex_unlock(&prog->aux->used_maps_mutex); 5190 5191 err = set_info_rec_size(&info); 5192 if (err) 5193 return err; 5194 5195 bpf_prog_get_stats(prog, &stats); 5196 info.run_time_ns = stats.nsecs; 5197 info.run_cnt = stats.cnt; 5198 info.recursion_misses = stats.misses; 5199 5200 info.verified_insns = prog->aux->verified_insns; 5201 if (prog->aux->btf) 5202 info.btf_id = btf_obj_id(prog->aux->btf); 5203 5204 if (!bpf_capable()) { 5205 info.jited_prog_len = 0; 5206 info.xlated_prog_len = 0; 5207 info.nr_jited_ksyms = 0; 5208 info.nr_jited_func_lens = 0; 5209 info.nr_func_info = 0; 5210 info.nr_line_info = 0; 5211 info.nr_jited_line_info = 0; 5212 goto done; 5213 } 5214 5215 ulen = info.xlated_prog_len; 5216 info.xlated_prog_len = bpf_prog_insn_size(prog); 5217 if (info.xlated_prog_len && ulen) { 5218 struct bpf_insn *insns_sanitized; 5219 bool fault; 5220 5221 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) { 5222 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 5223 if (!insns_sanitized) 5224 return -ENOMEM; 5225 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 5226 ulen = min_t(u32, info.xlated_prog_len, ulen); 5227 fault = copy_to_user(uinsns, insns_sanitized, ulen); 5228 kfree(insns_sanitized); 5229 if (fault) 5230 return -EFAULT; 5231 } else { 5232 info.xlated_prog_insns = 0; 5233 } 5234 } 5235 5236 if (bpf_prog_is_offloaded(prog->aux)) { 5237 err = bpf_prog_offload_info_fill(&info, prog); 5238 if (err) 5239 return err; 5240 goto done; 5241 } 5242 5243 /* NOTE: the following code is supposed to be skipped for offload. 5244 * bpf_prog_offload_info_fill() is the place to fill similar fields 5245 * for offload. 5246 */ 5247 ulen = info.jited_prog_len; 5248 if (prog->aux->func_cnt) { 5249 u32 i; 5250 5251 info.jited_prog_len = 0; 5252 for (i = 0; i < prog->aux->func_cnt; i++) 5253 info.jited_prog_len += prog->aux->func[i]->jited_len; 5254 } else { 5255 info.jited_prog_len = prog->jited_len; 5256 } 5257 5258 if (info.jited_prog_len && ulen) { 5259 if (bpf_dump_raw_ok(file->f_cred)) { 5260 uinsns = u64_to_user_ptr(info.jited_prog_insns); 5261 ulen = min_t(u32, info.jited_prog_len, ulen); 5262 5263 /* for multi-function programs, copy the JITed 5264 * instructions for all the functions 5265 */ 5266 if (prog->aux->func_cnt) { 5267 u32 len, free, i; 5268 u8 *img; 5269 5270 free = ulen; 5271 for (i = 0; i < prog->aux->func_cnt; i++) { 5272 len = prog->aux->func[i]->jited_len; 5273 len = min_t(u32, len, free); 5274 img = (u8 *) prog->aux->func[i]->bpf_func; 5275 if (copy_to_user(uinsns, img, len)) 5276 return -EFAULT; 5277 uinsns += len; 5278 free -= len; 5279 if (!free) 5280 break; 5281 } 5282 } else { 5283 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 5284 return -EFAULT; 5285 } 5286 } else { 5287 info.jited_prog_insns = 0; 5288 } 5289 } 5290 5291 ulen = info.nr_jited_ksyms; 5292 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 5293 if (ulen) { 5294 if (bpf_dump_raw_ok(file->f_cred)) { 5295 unsigned long ksym_addr; 5296 u64 __user *user_ksyms; 5297 u32 i; 5298 5299 /* copy the address of the kernel symbol 5300 * corresponding to each function 5301 */ 5302 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 5303 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 5304 if (prog->aux->func_cnt) { 5305 for (i = 0; i < ulen; i++) { 5306 ksym_addr = (unsigned long) 5307 prog->aux->func[i]->bpf_func; 5308 if (put_user((u64) ksym_addr, 5309 &user_ksyms[i])) 5310 return -EFAULT; 5311 } 5312 } else { 5313 ksym_addr = (unsigned long) prog->bpf_func; 5314 if (put_user((u64) ksym_addr, &user_ksyms[0])) 5315 return -EFAULT; 5316 } 5317 } else { 5318 info.jited_ksyms = 0; 5319 } 5320 } 5321 5322 ulen = info.nr_jited_func_lens; 5323 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 5324 if (ulen) { 5325 if (bpf_dump_raw_ok(file->f_cred)) { 5326 u32 __user *user_lens; 5327 u32 func_len, i; 5328 5329 /* copy the JITed image lengths for each function */ 5330 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 5331 user_lens = u64_to_user_ptr(info.jited_func_lens); 5332 if (prog->aux->func_cnt) { 5333 for (i = 0; i < ulen; i++) { 5334 func_len = 5335 prog->aux->func[i]->jited_len; 5336 if (put_user(func_len, &user_lens[i])) 5337 return -EFAULT; 5338 } 5339 } else { 5340 func_len = prog->jited_len; 5341 if (put_user(func_len, &user_lens[0])) 5342 return -EFAULT; 5343 } 5344 } else { 5345 info.jited_func_lens = 0; 5346 } 5347 } 5348 5349 info.attach_btf_id = prog->aux->attach_btf_id; 5350 if (attach_btf) 5351 info.attach_btf_obj_id = btf_obj_id(attach_btf); 5352 5353 ulen = info.nr_func_info; 5354 info.nr_func_info = prog->aux->func_info_cnt; 5355 if (info.nr_func_info && ulen) { 5356 char __user *user_finfo; 5357 5358 user_finfo = u64_to_user_ptr(info.func_info); 5359 ulen = min_t(u32, info.nr_func_info, ulen); 5360 if (copy_to_user(user_finfo, prog->aux->func_info, 5361 info.func_info_rec_size * ulen)) 5362 return -EFAULT; 5363 } 5364 5365 ulen = info.nr_line_info; 5366 info.nr_line_info = prog->aux->nr_linfo; 5367 if (info.nr_line_info && ulen) { 5368 __u8 __user *user_linfo; 5369 5370 user_linfo = u64_to_user_ptr(info.line_info); 5371 ulen = min_t(u32, info.nr_line_info, ulen); 5372 if (copy_to_user(user_linfo, prog->aux->linfo, 5373 info.line_info_rec_size * ulen)) 5374 return -EFAULT; 5375 } 5376 5377 ulen = info.nr_jited_line_info; 5378 if (prog->aux->jited_linfo) 5379 info.nr_jited_line_info = prog->aux->nr_linfo; 5380 else 5381 info.nr_jited_line_info = 0; 5382 if (info.nr_jited_line_info && ulen) { 5383 if (bpf_dump_raw_ok(file->f_cred)) { 5384 unsigned long line_addr; 5385 __u64 __user *user_linfo; 5386 u32 i; 5387 5388 user_linfo = u64_to_user_ptr(info.jited_line_info); 5389 ulen = min_t(u32, info.nr_jited_line_info, ulen); 5390 for (i = 0; i < ulen; i++) { 5391 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 5392 if (put_user((__u64)line_addr, &user_linfo[i])) 5393 return -EFAULT; 5394 } 5395 } else { 5396 info.jited_line_info = 0; 5397 } 5398 } 5399 5400 ulen = info.nr_prog_tags; 5401 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 5402 if (ulen) { 5403 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 5404 u32 i; 5405 5406 user_prog_tags = u64_to_user_ptr(info.prog_tags); 5407 ulen = min_t(u32, info.nr_prog_tags, ulen); 5408 if (prog->aux->func_cnt) { 5409 for (i = 0; i < ulen; i++) { 5410 if (copy_to_user(user_prog_tags[i], 5411 prog->aux->func[i]->tag, 5412 BPF_TAG_SIZE)) 5413 return -EFAULT; 5414 } 5415 } else { 5416 if (copy_to_user(user_prog_tags[0], 5417 prog->tag, BPF_TAG_SIZE)) 5418 return -EFAULT; 5419 } 5420 } 5421 5422 done: 5423 if (copy_to_user(uinfo, &info, info_len) || 5424 put_user(info_len, &uattr->info.info_len)) 5425 return -EFAULT; 5426 5427 return 0; 5428 } 5429 5430 static int bpf_map_get_info_by_fd(struct file *file, 5431 struct bpf_map *map, 5432 const union bpf_attr *attr, 5433 union bpf_attr __user *uattr) 5434 { 5435 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5436 struct bpf_map_info info; 5437 u32 info_len = attr->info.info_len, len; 5438 int err; 5439 5440 len = offsetofend(struct bpf_map_info, hash_size); 5441 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len); 5442 if (err) 5443 return err; 5444 info_len = min_t(u32, sizeof(info), info_len); 5445 5446 memset(&info, 0, sizeof(info)); 5447 if (copy_from_user(&info, uinfo, info_len)) 5448 return -EFAULT; 5449 5450 info.type = map->map_type; 5451 info.id = map->id; 5452 info.key_size = map->key_size; 5453 info.value_size = map->value_size; 5454 info.max_entries = map->max_entries; 5455 info.map_flags = map->map_flags; 5456 info.map_extra = map->map_extra; 5457 memcpy(info.name, map->name, sizeof(map->name)); 5458 5459 if (map->btf) { 5460 info.btf_id = btf_obj_id(map->btf); 5461 info.btf_key_type_id = map->btf_key_type_id; 5462 info.btf_value_type_id = map->btf_value_type_id; 5463 } 5464 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 5465 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 5466 bpf_map_struct_ops_info_fill(&info, map); 5467 5468 if (bpf_map_is_offloaded(map)) { 5469 err = bpf_map_offload_info_fill(&info, map); 5470 if (err) 5471 return err; 5472 } 5473 5474 if (info.hash) { 5475 char __user *uhash = u64_to_user_ptr(info.hash); 5476 5477 if (!map->ops->map_get_hash) 5478 return -EINVAL; 5479 if (info.hash_size != sizeof(map->sha)) 5480 return -EINVAL; 5481 if (!READ_ONCE(map->frozen)) 5482 return -EPERM; 5483 5484 err = map->ops->map_get_hash(map); 5485 if (err != 0) 5486 return err; 5487 5488 if (copy_to_user(uhash, map->sha, sizeof(map->sha)) != 0) 5489 return -EFAULT; 5490 } else if (info.hash_size) { 5491 return -EINVAL; 5492 } 5493 5494 if (copy_to_user(uinfo, &info, info_len) || 5495 put_user(info_len, &uattr->info.info_len)) 5496 return -EFAULT; 5497 5498 return 0; 5499 } 5500 5501 static int bpf_btf_get_info_by_fd(struct file *file, 5502 struct btf *btf, 5503 const union bpf_attr *attr, 5504 union bpf_attr __user *uattr) 5505 { 5506 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5507 u32 info_len = attr->info.info_len; 5508 int err; 5509 5510 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5511 if (err) 5512 return err; 5513 5514 return btf_get_info_by_fd(btf, attr, uattr); 5515 } 5516 5517 static int bpf_link_get_info_by_fd(struct file *file, 5518 struct bpf_link *link, 5519 const union bpf_attr *attr, 5520 union bpf_attr __user *uattr) 5521 { 5522 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5523 struct bpf_link_info info; 5524 const struct bpf_prog *prog; 5525 u32 info_len = attr->info.info_len; 5526 int err; 5527 5528 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5529 if (err) 5530 return err; 5531 info_len = min_t(u32, sizeof(info), info_len); 5532 5533 memset(&info, 0, sizeof(info)); 5534 if (copy_from_user(&info, uinfo, info_len)) 5535 return -EFAULT; 5536 5537 info.type = link->type; 5538 info.id = link->id; 5539 5540 rcu_read_lock(); 5541 prog = READ_ONCE(link->prog); 5542 if (prog) 5543 info.prog_id = prog->aux->id; 5544 rcu_read_unlock(); 5545 5546 if (link->ops->fill_link_info) { 5547 err = link->ops->fill_link_info(link, &info); 5548 if (err) 5549 return err; 5550 } 5551 5552 if (copy_to_user(uinfo, &info, info_len) || 5553 put_user(info_len, &uattr->info.info_len)) 5554 return -EFAULT; 5555 5556 return 0; 5557 } 5558 5559 static int token_get_info_by_fd(struct file *file, 5560 struct bpf_token *token, 5561 const union bpf_attr *attr, 5562 union bpf_attr __user *uattr) 5563 { 5564 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5565 u32 info_len = attr->info.info_len; 5566 int err; 5567 5568 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5569 if (err) 5570 return err; 5571 return bpf_token_get_info_by_fd(token, attr, uattr); 5572 } 5573 5574 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5575 5576 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5577 union bpf_attr __user *uattr) 5578 { 5579 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5580 return -EINVAL; 5581 5582 CLASS(fd, f)(attr->info.bpf_fd); 5583 if (fd_empty(f)) 5584 return -EBADFD; 5585 5586 if (fd_file(f)->f_op == &bpf_prog_fops) 5587 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5588 uattr); 5589 else if (fd_file(f)->f_op == &bpf_map_fops) 5590 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5591 uattr); 5592 else if (fd_file(f)->f_op == &btf_fops) 5593 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5594 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5595 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5596 attr, uattr); 5597 else if (fd_file(f)->f_op == &bpf_token_fops) 5598 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5599 attr, uattr); 5600 return -EINVAL; 5601 } 5602 5603 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5604 5605 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 5606 { 5607 struct bpf_token *token = NULL; 5608 5609 if (CHECK_ATTR(BPF_BTF_LOAD)) 5610 return -EINVAL; 5611 5612 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5613 return -EINVAL; 5614 5615 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5616 token = bpf_token_get_from_fd(attr->btf_token_fd); 5617 if (IS_ERR(token)) 5618 return PTR_ERR(token); 5619 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5620 bpf_token_put(token); 5621 token = NULL; 5622 } 5623 } 5624 5625 if (!bpf_token_capable(token, CAP_BPF)) { 5626 bpf_token_put(token); 5627 return -EPERM; 5628 } 5629 5630 bpf_token_put(token); 5631 5632 return btf_new_fd(attr, uattr, attr_log); 5633 } 5634 5635 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd 5636 5637 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5638 { 5639 struct bpf_token *token = NULL; 5640 5641 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5642 return -EINVAL; 5643 5644 if (attr->open_flags & ~BPF_F_TOKEN_FD) 5645 return -EINVAL; 5646 5647 if (attr->open_flags & BPF_F_TOKEN_FD) { 5648 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); 5649 if (IS_ERR(token)) 5650 return PTR_ERR(token); 5651 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { 5652 bpf_token_put(token); 5653 token = NULL; 5654 } 5655 } 5656 5657 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { 5658 bpf_token_put(token); 5659 return -EPERM; 5660 } 5661 5662 bpf_token_put(token); 5663 5664 return btf_get_fd_by_id(attr->btf_id); 5665 } 5666 5667 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5668 union bpf_attr __user *uattr, 5669 u32 prog_id, u32 fd_type, 5670 const char *buf, u64 probe_offset, 5671 u64 probe_addr) 5672 { 5673 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5674 u32 len = buf ? strlen(buf) : 0, input_len; 5675 int err = 0; 5676 5677 if (put_user(len, &uattr->task_fd_query.buf_len)) 5678 return -EFAULT; 5679 input_len = attr->task_fd_query.buf_len; 5680 if (input_len && ubuf) { 5681 if (!len) { 5682 /* nothing to copy, just make ubuf NULL terminated */ 5683 char zero = '\0'; 5684 5685 if (put_user(zero, ubuf)) 5686 return -EFAULT; 5687 } else { 5688 err = bpf_copy_to_user(ubuf, buf, input_len, len); 5689 if (err == -EFAULT) 5690 return err; 5691 } 5692 } 5693 5694 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5695 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5696 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5697 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5698 return -EFAULT; 5699 5700 return err; 5701 } 5702 5703 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5704 5705 static int bpf_task_fd_query(const union bpf_attr *attr, 5706 union bpf_attr __user *uattr) 5707 { 5708 pid_t pid = attr->task_fd_query.pid; 5709 u32 fd = attr->task_fd_query.fd; 5710 const struct perf_event *event; 5711 struct task_struct *task; 5712 struct file *file; 5713 int err; 5714 5715 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5716 return -EINVAL; 5717 5718 if (!capable(CAP_SYS_ADMIN)) 5719 return -EPERM; 5720 5721 if (attr->task_fd_query.flags != 0) 5722 return -EINVAL; 5723 5724 rcu_read_lock(); 5725 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5726 rcu_read_unlock(); 5727 if (!task) 5728 return -ENOENT; 5729 5730 err = 0; 5731 file = fget_task(task, fd); 5732 put_task_struct(task); 5733 if (!file) 5734 return -EBADF; 5735 5736 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5737 struct bpf_link *link = file->private_data; 5738 5739 if (link->ops == &bpf_raw_tp_link_lops) { 5740 struct bpf_raw_tp_link *raw_tp = 5741 container_of(link, struct bpf_raw_tp_link, link); 5742 struct bpf_raw_event_map *btp = raw_tp->btp; 5743 5744 err = bpf_task_fd_query_copy(attr, uattr, 5745 raw_tp->link.prog->aux->id, 5746 BPF_FD_TYPE_RAW_TRACEPOINT, 5747 btp->tp->name, 0, 0); 5748 goto put_file; 5749 } 5750 goto out_not_supp; 5751 } 5752 5753 event = perf_get_event(file); 5754 if (!IS_ERR(event)) { 5755 u64 probe_offset, probe_addr; 5756 u32 prog_id, fd_type; 5757 const char *buf; 5758 5759 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5760 &buf, &probe_offset, 5761 &probe_addr, NULL); 5762 if (!err) 5763 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5764 fd_type, buf, 5765 probe_offset, 5766 probe_addr); 5767 goto put_file; 5768 } 5769 5770 out_not_supp: 5771 err = -ENOTSUPP; 5772 put_file: 5773 fput(file); 5774 return err; 5775 } 5776 5777 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5778 5779 #define BPF_DO_BATCH(fn, ...) \ 5780 do { \ 5781 if (!fn) { \ 5782 err = -ENOTSUPP; \ 5783 goto err_put; \ 5784 } \ 5785 err = fn(__VA_ARGS__); \ 5786 } while (0) 5787 5788 static int bpf_map_do_batch(const union bpf_attr *attr, 5789 union bpf_attr __user *uattr, 5790 int cmd) 5791 { 5792 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5793 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5794 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5795 struct bpf_map *map; 5796 int err; 5797 5798 if (CHECK_ATTR(BPF_MAP_BATCH)) 5799 return -EINVAL; 5800 5801 CLASS(fd, f)(attr->batch.map_fd); 5802 5803 map = __bpf_map_get(f); 5804 if (IS_ERR(map)) 5805 return PTR_ERR(map); 5806 if (has_write) 5807 bpf_map_write_active_inc(map); 5808 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5809 err = -EPERM; 5810 goto err_put; 5811 } 5812 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5813 err = -EPERM; 5814 goto err_put; 5815 } 5816 5817 if (cmd == BPF_MAP_LOOKUP_BATCH) 5818 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5819 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5820 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5821 else if (cmd == BPF_MAP_UPDATE_BATCH) 5822 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5823 else 5824 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5825 err_put: 5826 if (has_write) { 5827 maybe_wait_bpf_programs(map); 5828 bpf_map_write_active_dec(map); 5829 } 5830 return err; 5831 } 5832 5833 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.path_fd 5834 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5835 { 5836 struct bpf_prog *prog; 5837 int ret; 5838 5839 if (CHECK_ATTR(BPF_LINK_CREATE)) 5840 return -EINVAL; 5841 5842 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5843 return bpf_struct_ops_link_create(attr); 5844 5845 prog = bpf_prog_get(attr->link_create.prog_fd); 5846 if (IS_ERR(prog)) 5847 return PTR_ERR(prog); 5848 5849 ret = bpf_prog_attach_check_attach_type(prog, 5850 attr->link_create.attach_type); 5851 if (ret) 5852 goto out; 5853 5854 switch (prog->type) { 5855 case BPF_PROG_TYPE_CGROUP_SKB: 5856 case BPF_PROG_TYPE_CGROUP_SOCK: 5857 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5858 case BPF_PROG_TYPE_SOCK_OPS: 5859 case BPF_PROG_TYPE_CGROUP_DEVICE: 5860 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5861 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5862 ret = cgroup_bpf_link_attach(attr, prog); 5863 break; 5864 case BPF_PROG_TYPE_EXT: 5865 ret = bpf_tracing_prog_attach(prog, 5866 attr->link_create.target_fd, 5867 attr->link_create.target_btf_id, 5868 attr->link_create.tracing.cookie, 5869 attr->link_create.attach_type); 5870 break; 5871 case BPF_PROG_TYPE_LSM: 5872 case BPF_PROG_TYPE_TRACING: 5873 if (attr->link_create.attach_type != prog->expected_attach_type) { 5874 ret = -EINVAL; 5875 goto out; 5876 } 5877 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5878 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, 5879 attr->link_create.attach_type); 5880 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5881 ret = bpf_iter_link_attach(attr, uattr, prog); 5882 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5883 ret = cgroup_bpf_link_attach(attr, prog); 5884 else if (is_tracing_multi(prog->expected_attach_type)) 5885 ret = bpf_tracing_multi_attach(prog, attr); 5886 else 5887 ret = bpf_tracing_prog_attach(prog, 5888 attr->link_create.target_fd, 5889 attr->link_create.target_btf_id, 5890 attr->link_create.tracing.cookie, 5891 attr->link_create.attach_type); 5892 break; 5893 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5894 case BPF_PROG_TYPE_SK_LOOKUP: 5895 ret = netns_bpf_link_create(attr, prog); 5896 break; 5897 case BPF_PROG_TYPE_SK_MSG: 5898 case BPF_PROG_TYPE_SK_SKB: 5899 ret = sock_map_link_create(attr, prog); 5900 break; 5901 #ifdef CONFIG_NET 5902 case BPF_PROG_TYPE_XDP: 5903 ret = bpf_xdp_link_attach(attr, prog); 5904 break; 5905 case BPF_PROG_TYPE_SCHED_CLS: 5906 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5907 attr->link_create.attach_type == BPF_TCX_EGRESS) 5908 ret = tcx_link_attach(attr, prog); 5909 else 5910 ret = netkit_link_attach(attr, prog); 5911 break; 5912 case BPF_PROG_TYPE_NETFILTER: 5913 ret = bpf_nf_link_attach(attr, prog); 5914 break; 5915 #endif 5916 case BPF_PROG_TYPE_PERF_EVENT: 5917 case BPF_PROG_TYPE_TRACEPOINT: 5918 ret = bpf_perf_link_attach(attr, prog); 5919 break; 5920 case BPF_PROG_TYPE_KPROBE: 5921 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5922 ret = bpf_perf_link_attach(attr, prog); 5923 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5924 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5925 ret = bpf_kprobe_multi_link_attach(attr, prog); 5926 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5927 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5928 ret = bpf_uprobe_multi_link_attach(attr, prog); 5929 break; 5930 default: 5931 ret = -EINVAL; 5932 } 5933 5934 out: 5935 if (ret < 0) 5936 bpf_prog_put(prog); 5937 return ret; 5938 } 5939 5940 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5941 { 5942 struct bpf_map *new_map, *old_map = NULL; 5943 int ret; 5944 5945 new_map = bpf_map_get(attr->link_update.new_map_fd); 5946 if (IS_ERR(new_map)) 5947 return PTR_ERR(new_map); 5948 5949 if (attr->link_update.flags & BPF_F_REPLACE) { 5950 old_map = bpf_map_get(attr->link_update.old_map_fd); 5951 if (IS_ERR(old_map)) { 5952 ret = PTR_ERR(old_map); 5953 goto out_put; 5954 } 5955 } else if (attr->link_update.old_map_fd) { 5956 ret = -EINVAL; 5957 goto out_put; 5958 } 5959 5960 ret = link->ops->update_map(link, new_map, old_map); 5961 5962 if (old_map) 5963 bpf_map_put(old_map); 5964 out_put: 5965 bpf_map_put(new_map); 5966 return ret; 5967 } 5968 5969 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5970 5971 static int link_update(union bpf_attr *attr) 5972 { 5973 struct bpf_prog *old_prog = NULL, *new_prog; 5974 struct bpf_link *link; 5975 u32 flags; 5976 int ret; 5977 5978 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5979 return -EINVAL; 5980 5981 flags = attr->link_update.flags; 5982 if (flags & ~BPF_F_REPLACE) 5983 return -EINVAL; 5984 5985 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5986 if (IS_ERR(link)) 5987 return PTR_ERR(link); 5988 5989 if (link->ops->update_map) { 5990 ret = link_update_map(link, attr); 5991 goto out_put_link; 5992 } 5993 5994 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5995 if (IS_ERR(new_prog)) { 5996 ret = PTR_ERR(new_prog); 5997 goto out_put_link; 5998 } 5999 6000 if (flags & BPF_F_REPLACE) { 6001 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 6002 if (IS_ERR(old_prog)) { 6003 ret = PTR_ERR(old_prog); 6004 old_prog = NULL; 6005 goto out_put_progs; 6006 } 6007 } else if (attr->link_update.old_prog_fd) { 6008 ret = -EINVAL; 6009 goto out_put_progs; 6010 } 6011 6012 if (link->ops->update_prog) 6013 ret = link->ops->update_prog(link, new_prog, old_prog); 6014 else 6015 ret = -EINVAL; 6016 6017 out_put_progs: 6018 if (old_prog) 6019 bpf_prog_put(old_prog); 6020 if (ret) 6021 bpf_prog_put(new_prog); 6022 out_put_link: 6023 bpf_link_put_direct(link); 6024 return ret; 6025 } 6026 6027 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 6028 6029 static int link_detach(union bpf_attr *attr) 6030 { 6031 struct bpf_link *link; 6032 int ret; 6033 6034 if (CHECK_ATTR(BPF_LINK_DETACH)) 6035 return -EINVAL; 6036 6037 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 6038 if (IS_ERR(link)) 6039 return PTR_ERR(link); 6040 6041 if (link->ops->detach) 6042 ret = link->ops->detach(link); 6043 else 6044 ret = -EOPNOTSUPP; 6045 6046 bpf_link_put_direct(link); 6047 return ret; 6048 } 6049 6050 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 6051 { 6052 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 6053 } 6054 EXPORT_SYMBOL(bpf_link_inc_not_zero); 6055 6056 struct bpf_link *bpf_link_by_id(u32 id) 6057 { 6058 struct bpf_link *link; 6059 6060 if (!id) 6061 return ERR_PTR(-ENOENT); 6062 6063 spin_lock_bh(&link_idr_lock); 6064 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 6065 link = idr_find(&link_idr, id); 6066 if (link) { 6067 if (link->id) 6068 link = bpf_link_inc_not_zero(link); 6069 else 6070 link = ERR_PTR(-EAGAIN); 6071 } else { 6072 link = ERR_PTR(-ENOENT); 6073 } 6074 spin_unlock_bh(&link_idr_lock); 6075 return link; 6076 } 6077 6078 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 6079 { 6080 struct bpf_link *link; 6081 6082 spin_lock_bh(&link_idr_lock); 6083 again: 6084 link = idr_get_next(&link_idr, id); 6085 if (link) { 6086 if (link->id) 6087 link = bpf_link_inc_not_zero(link); 6088 else 6089 link = ERR_PTR(-EAGAIN); 6090 if (IS_ERR(link)) { 6091 (*id)++; 6092 goto again; 6093 } 6094 } 6095 spin_unlock_bh(&link_idr_lock); 6096 6097 return link; 6098 } 6099 6100 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 6101 6102 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 6103 { 6104 struct bpf_link *link; 6105 u32 id = attr->link_id; 6106 int fd; 6107 6108 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 6109 return -EINVAL; 6110 6111 if (!capable(CAP_SYS_ADMIN)) 6112 return -EPERM; 6113 6114 link = bpf_link_by_id(id); 6115 if (IS_ERR(link)) 6116 return PTR_ERR(link); 6117 6118 fd = bpf_link_new_fd(link); 6119 if (fd < 0) 6120 bpf_link_put_direct(link); 6121 6122 return fd; 6123 } 6124 6125 DEFINE_MUTEX(bpf_stats_enabled_mutex); 6126 6127 static int bpf_stats_release(struct inode *inode, struct file *file) 6128 { 6129 mutex_lock(&bpf_stats_enabled_mutex); 6130 static_key_slow_dec(&bpf_stats_enabled_key.key); 6131 mutex_unlock(&bpf_stats_enabled_mutex); 6132 return 0; 6133 } 6134 6135 static const struct file_operations bpf_stats_fops = { 6136 .release = bpf_stats_release, 6137 }; 6138 6139 static int bpf_enable_runtime_stats(void) 6140 { 6141 int fd; 6142 6143 mutex_lock(&bpf_stats_enabled_mutex); 6144 6145 /* Set a very high limit to avoid overflow */ 6146 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 6147 mutex_unlock(&bpf_stats_enabled_mutex); 6148 return -EBUSY; 6149 } 6150 6151 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 6152 if (fd >= 0) 6153 static_key_slow_inc(&bpf_stats_enabled_key.key); 6154 6155 mutex_unlock(&bpf_stats_enabled_mutex); 6156 return fd; 6157 } 6158 6159 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 6160 6161 static int bpf_enable_stats(union bpf_attr *attr) 6162 { 6163 6164 if (CHECK_ATTR(BPF_ENABLE_STATS)) 6165 return -EINVAL; 6166 6167 if (!capable(CAP_SYS_ADMIN)) 6168 return -EPERM; 6169 6170 switch (attr->enable_stats.type) { 6171 case BPF_STATS_RUN_TIME: 6172 return bpf_enable_runtime_stats(); 6173 default: 6174 break; 6175 } 6176 return -EINVAL; 6177 } 6178 6179 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 6180 6181 static int bpf_iter_create(union bpf_attr *attr) 6182 { 6183 struct bpf_link *link; 6184 int err; 6185 6186 if (CHECK_ATTR(BPF_ITER_CREATE)) 6187 return -EINVAL; 6188 6189 if (attr->iter_create.flags) 6190 return -EINVAL; 6191 6192 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 6193 if (IS_ERR(link)) 6194 return PTR_ERR(link); 6195 6196 err = bpf_iter_new_fd(link); 6197 bpf_link_put_direct(link); 6198 6199 return err; 6200 } 6201 6202 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 6203 6204 static int bpf_prog_bind_map(union bpf_attr *attr) 6205 { 6206 struct bpf_prog *prog; 6207 struct bpf_map *map; 6208 struct bpf_map **used_maps_old, **used_maps_new; 6209 int i, ret = 0; 6210 6211 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 6212 return -EINVAL; 6213 6214 if (attr->prog_bind_map.flags) 6215 return -EINVAL; 6216 6217 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 6218 if (IS_ERR(prog)) 6219 return PTR_ERR(prog); 6220 6221 map = bpf_map_get(attr->prog_bind_map.map_fd); 6222 if (IS_ERR(map)) { 6223 ret = PTR_ERR(map); 6224 goto out_prog_put; 6225 } 6226 6227 mutex_lock(&prog->aux->used_maps_mutex); 6228 6229 used_maps_old = prog->aux->used_maps; 6230 6231 for (i = 0; i < prog->aux->used_map_cnt; i++) 6232 if (used_maps_old[i] == map) { 6233 bpf_map_put(map); 6234 goto out_unlock; 6235 } 6236 6237 used_maps_new = kmalloc_objs(used_maps_new[0], 6238 prog->aux->used_map_cnt + 1); 6239 if (!used_maps_new) { 6240 ret = -ENOMEM; 6241 goto out_unlock; 6242 } 6243 6244 /* The bpf program will not access the bpf map, but for the sake of 6245 * simplicity, increase sleepable_refcnt for sleepable program as well. 6246 */ 6247 if (prog->sleepable) 6248 atomic64_inc(&map->sleepable_refcnt); 6249 memcpy(used_maps_new, used_maps_old, 6250 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 6251 used_maps_new[prog->aux->used_map_cnt] = map; 6252 6253 prog->aux->used_map_cnt++; 6254 prog->aux->used_maps = used_maps_new; 6255 6256 kfree(used_maps_old); 6257 6258 out_unlock: 6259 mutex_unlock(&prog->aux->used_maps_mutex); 6260 6261 if (ret) 6262 bpf_map_put(map); 6263 out_prog_put: 6264 bpf_prog_put(prog); 6265 return ret; 6266 } 6267 6268 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 6269 6270 static int token_create(union bpf_attr *attr) 6271 { 6272 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 6273 return -EINVAL; 6274 6275 /* no flags are supported yet */ 6276 if (attr->token_create.flags) 6277 return -EINVAL; 6278 6279 return bpf_token_create(attr); 6280 } 6281 6282 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd 6283 6284 static int prog_stream_read(union bpf_attr *attr) 6285 { 6286 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); 6287 u32 len = attr->prog_stream_read.stream_buf_len; 6288 struct bpf_prog *prog; 6289 int ret; 6290 6291 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) 6292 return -EINVAL; 6293 6294 prog = bpf_prog_get(attr->prog_stream_read.prog_fd); 6295 if (IS_ERR(prog)) 6296 return PTR_ERR(prog); 6297 6298 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); 6299 bpf_prog_put(prog); 6300 6301 return ret; 6302 } 6303 6304 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.flags 6305 6306 static int prog_assoc_struct_ops(union bpf_attr *attr) 6307 { 6308 struct bpf_prog *prog; 6309 struct bpf_map *map; 6310 int ret; 6311 6312 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS)) 6313 return -EINVAL; 6314 6315 if (attr->prog_assoc_struct_ops.flags) 6316 return -EINVAL; 6317 6318 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd); 6319 if (IS_ERR(prog)) 6320 return PTR_ERR(prog); 6321 6322 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) { 6323 ret = -EINVAL; 6324 goto put_prog; 6325 } 6326 6327 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd); 6328 if (IS_ERR(map)) { 6329 ret = PTR_ERR(map); 6330 goto put_prog; 6331 } 6332 6333 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 6334 ret = -EINVAL; 6335 goto put_map; 6336 } 6337 6338 ret = bpf_prog_assoc_struct_ops(prog, map); 6339 6340 put_map: 6341 bpf_map_put(map); 6342 put_prog: 6343 bpf_prog_put(prog); 6344 return ret; 6345 } 6346 6347 #define BPF_PROG_STREAM_OPEN_LAST_FIELD prog_stream_open.flags 6348 6349 static int prog_stream_open(union bpf_attr *attr) 6350 { 6351 struct bpf_prog *prog; 6352 u32 flags = attr->prog_stream_open.flags; 6353 int ret; 6354 6355 if (CHECK_ATTR(BPF_PROG_STREAM_OPEN)) 6356 return -EINVAL; 6357 if (flags & ~BPF_F_STREAM_NONBLOCK) 6358 return -EINVAL; 6359 6360 prog = bpf_prog_get(attr->prog_stream_open.prog_fd); 6361 if (IS_ERR(prog)) 6362 return PTR_ERR(prog); 6363 6364 ret = bpf_prog_stream_new_fd(prog, attr->prog_stream_open.stream_id, flags); 6365 bpf_prog_put(prog); 6366 return ret; 6367 } 6368 6369 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, 6370 bpfptr_t uattr_common, unsigned int size_common) 6371 { 6372 struct bpf_common_attr attr_common; 6373 u32 offsetof_log_true_size = 0; 6374 struct bpf_log_attr attr_log; 6375 union bpf_attr attr; 6376 int err; 6377 6378 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 6379 if (err) 6380 return err; 6381 size = min_t(u32, size, sizeof(attr)); 6382 6383 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 6384 memset(&attr, 0, sizeof(attr)); 6385 if (copy_from_bpfptr(&attr, uattr, size) != 0) 6386 return -EFAULT; 6387 6388 memset(&attr_common, 0, sizeof(attr_common)); 6389 if (cmd & BPF_COMMON_ATTRS) { 6390 err = bpf_check_uarg_tail_zero(uattr_common, 6391 offsetofend(struct bpf_common_attr, log_true_size), 6392 size_common); 6393 if (err) 6394 return err; 6395 6396 cmd &= ~BPF_COMMON_ATTRS; 6397 size_common = min_t(u32, size_common, sizeof(attr_common)); 6398 if (copy_from_bpfptr(&attr_common, uattr_common, size_common) != 0) 6399 return -EFAULT; 6400 } else { 6401 size_common = 0; 6402 } 6403 6404 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 6405 if (err < 0) 6406 return err; 6407 6408 switch (cmd) { 6409 case BPF_MAP_CREATE: 6410 err = map_create(&attr, uattr, &attr_common, uattr_common, size_common); 6411 break; 6412 case BPF_MAP_LOOKUP_ELEM: 6413 err = map_lookup_elem(&attr); 6414 break; 6415 case BPF_MAP_UPDATE_ELEM: 6416 err = map_update_elem(&attr, uattr); 6417 break; 6418 case BPF_MAP_DELETE_ELEM: 6419 err = map_delete_elem(&attr, uattr); 6420 break; 6421 case BPF_MAP_GET_NEXT_KEY: 6422 err = map_get_next_key(&attr); 6423 break; 6424 case BPF_MAP_FREEZE: 6425 err = map_freeze(&attr); 6426 break; 6427 case BPF_PROG_LOAD: 6428 if (size >= offsetofend(union bpf_attr, log_true_size)) 6429 offsetof_log_true_size = offsetof(union bpf_attr, log_true_size); 6430 err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level, 6431 offsetof_log_true_size, uattr, &attr_common, uattr_common, 6432 size_common); 6433 err = err ?: bpf_prog_load(&attr, uattr, &attr_log); 6434 break; 6435 case BPF_OBJ_PIN: 6436 err = bpf_obj_pin(&attr); 6437 break; 6438 case BPF_OBJ_GET: 6439 err = bpf_obj_get(&attr); 6440 break; 6441 case BPF_PROG_ATTACH: 6442 err = bpf_prog_attach(&attr); 6443 break; 6444 case BPF_PROG_DETACH: 6445 err = bpf_prog_detach(&attr); 6446 break; 6447 case BPF_PROG_QUERY: 6448 err = bpf_prog_query(&attr, uattr.user, size); 6449 break; 6450 case BPF_PROG_TEST_RUN: 6451 err = bpf_prog_test_run(&attr, uattr.user); 6452 break; 6453 case BPF_PROG_GET_NEXT_ID: 6454 err = bpf_obj_get_next_id(&attr, uattr.user, 6455 &prog_idr, &prog_idr_lock); 6456 break; 6457 case BPF_MAP_GET_NEXT_ID: 6458 err = bpf_obj_get_next_id(&attr, uattr.user, 6459 &map_idr, &map_idr_lock); 6460 break; 6461 case BPF_BTF_GET_NEXT_ID: 6462 err = bpf_obj_get_next_id(&attr, uattr.user, 6463 &btf_idr, &btf_idr_lock); 6464 break; 6465 case BPF_PROG_GET_FD_BY_ID: 6466 err = bpf_prog_get_fd_by_id(&attr); 6467 break; 6468 case BPF_MAP_GET_FD_BY_ID: 6469 err = bpf_map_get_fd_by_id(&attr); 6470 break; 6471 case BPF_OBJ_GET_INFO_BY_FD: 6472 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 6473 break; 6474 case BPF_RAW_TRACEPOINT_OPEN: 6475 err = bpf_raw_tracepoint_open(&attr); 6476 break; 6477 case BPF_BTF_LOAD: 6478 if (size >= offsetofend(union bpf_attr, btf_log_true_size)) 6479 offsetof_log_true_size = offsetof(union bpf_attr, btf_log_true_size); 6480 err = bpf_log_attr_init(&attr_log, attr.btf_log_buf, attr.btf_log_size, 6481 attr.btf_log_level, offsetof_log_true_size, uattr, 6482 &attr_common, uattr_common, size_common); 6483 err = err ?: bpf_btf_load(&attr, uattr, &attr_log); 6484 break; 6485 case BPF_BTF_GET_FD_BY_ID: 6486 err = bpf_btf_get_fd_by_id(&attr); 6487 break; 6488 case BPF_TASK_FD_QUERY: 6489 err = bpf_task_fd_query(&attr, uattr.user); 6490 break; 6491 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 6492 err = map_lookup_and_delete_elem(&attr); 6493 break; 6494 case BPF_MAP_LOOKUP_BATCH: 6495 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 6496 break; 6497 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 6498 err = bpf_map_do_batch(&attr, uattr.user, 6499 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 6500 break; 6501 case BPF_MAP_UPDATE_BATCH: 6502 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 6503 break; 6504 case BPF_MAP_DELETE_BATCH: 6505 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 6506 break; 6507 case BPF_LINK_CREATE: 6508 err = link_create(&attr, uattr); 6509 break; 6510 case BPF_LINK_UPDATE: 6511 err = link_update(&attr); 6512 break; 6513 case BPF_LINK_GET_FD_BY_ID: 6514 err = bpf_link_get_fd_by_id(&attr); 6515 break; 6516 case BPF_LINK_GET_NEXT_ID: 6517 err = bpf_obj_get_next_id(&attr, uattr.user, 6518 &link_idr, &link_idr_lock); 6519 break; 6520 case BPF_ENABLE_STATS: 6521 err = bpf_enable_stats(&attr); 6522 break; 6523 case BPF_ITER_CREATE: 6524 err = bpf_iter_create(&attr); 6525 break; 6526 case BPF_LINK_DETACH: 6527 err = link_detach(&attr); 6528 break; 6529 case BPF_PROG_BIND_MAP: 6530 err = bpf_prog_bind_map(&attr); 6531 break; 6532 case BPF_TOKEN_CREATE: 6533 err = token_create(&attr); 6534 break; 6535 case BPF_PROG_STREAM_READ_BY_FD: 6536 err = prog_stream_read(&attr); 6537 break; 6538 case BPF_PROG_ASSOC_STRUCT_OPS: 6539 err = prog_assoc_struct_ops(&attr); 6540 break; 6541 case BPF_PROG_STREAM_OPEN: 6542 err = prog_stream_open(&attr); 6543 break; 6544 default: 6545 err = -EINVAL; 6546 break; 6547 } 6548 6549 return err; 6550 } 6551 6552 SYSCALL_DEFINE5(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size, 6553 struct bpf_common_attr __user *, uattr_common, unsigned int, size_common) 6554 { 6555 return __sys_bpf(cmd, USER_BPFPTR(uattr), size, USER_BPFPTR(uattr_common), size_common); 6556 } 6557 6558 static bool syscall_prog_is_valid_access(int off, int size, 6559 enum bpf_access_type type, 6560 const struct bpf_prog *prog, 6561 struct bpf_insn_access_aux *info) 6562 { 6563 if (off < 0 || off >= U16_MAX) 6564 return false; 6565 /* No alignment requirements for syscall ctx accesses. */ 6566 return true; 6567 } 6568 6569 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 6570 { 6571 switch (cmd) { 6572 case BPF_MAP_CREATE: 6573 case BPF_MAP_DELETE_ELEM: 6574 case BPF_MAP_UPDATE_ELEM: 6575 case BPF_MAP_FREEZE: 6576 case BPF_MAP_GET_FD_BY_ID: 6577 case BPF_PROG_LOAD: 6578 case BPF_BTF_LOAD: 6579 case BPF_LINK_CREATE: 6580 case BPF_RAW_TRACEPOINT_OPEN: 6581 break; 6582 default: 6583 return -EINVAL; 6584 } 6585 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size, KERNEL_BPFPTR(NULL), 0); 6586 } 6587 6588 /* To shut up -Wmissing-prototypes. 6589 * This function is used by the kernel light skeleton 6590 * to load bpf programs when modules are loaded or during kernel boot. 6591 * See tools/lib/bpf/skel_internal.h 6592 */ 6593 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 6594 6595 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 6596 { 6597 struct bpf_prog * __maybe_unused prog; 6598 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 6599 6600 switch (cmd) { 6601 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 6602 case BPF_PROG_TEST_RUN: 6603 if (attr->test.data_in || attr->test.data_out || 6604 attr->test.ctx_out || attr->test.duration || 6605 attr->test.repeat || attr->test.flags) 6606 return -EINVAL; 6607 6608 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 6609 if (IS_ERR(prog)) 6610 return PTR_ERR(prog); 6611 6612 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 6613 attr->test.ctx_size_in > U16_MAX) { 6614 bpf_prog_put(prog); 6615 return -EINVAL; 6616 } 6617 6618 run_ctx.bpf_cookie = 0; 6619 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 6620 /* recursion detected */ 6621 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 6622 bpf_prog_put(prog); 6623 return -EBUSY; 6624 } 6625 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 6626 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 6627 &run_ctx); 6628 bpf_prog_put(prog); 6629 return 0; 6630 #endif 6631 default: 6632 return ____bpf_sys_bpf(cmd, attr, size); 6633 } 6634 } 6635 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); 6636 6637 static const struct bpf_func_proto bpf_sys_bpf_proto = { 6638 .func = bpf_sys_bpf, 6639 .gpl_only = false, 6640 .might_sleep = true, 6641 .ret_type = RET_INTEGER, 6642 .arg1_type = ARG_ANYTHING, 6643 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6644 .arg3_type = ARG_MEM_SIZE, 6645 }; 6646 6647 const struct bpf_func_proto * __weak 6648 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6649 { 6650 return bpf_base_func_proto(func_id, prog); 6651 } 6652 6653 BPF_CALL_1(bpf_sys_close, u32, fd) 6654 { 6655 /* When bpf program calls this helper there should not be 6656 * an fdget() without matching completed fdput(). 6657 * This helper is allowed in the following callchain only: 6658 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6659 */ 6660 return close_fd(fd); 6661 } 6662 6663 static const struct bpf_func_proto bpf_sys_close_proto = { 6664 .func = bpf_sys_close, 6665 .gpl_only = false, 6666 .might_sleep = true, 6667 .ret_type = RET_INTEGER, 6668 .arg1_type = ARG_ANYTHING, 6669 }; 6670 6671 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6672 { 6673 *res = 0; 6674 if (flags) 6675 return -EINVAL; 6676 6677 if (name_sz <= 1 || name[name_sz - 1]) 6678 return -EINVAL; 6679 6680 if (!bpf_dump_raw_ok(current_cred())) 6681 return -EPERM; 6682 6683 *res = kallsyms_lookup_name(name); 6684 return *res ? 0 : -ENOENT; 6685 } 6686 6687 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6688 .func = bpf_kallsyms_lookup_name, 6689 .gpl_only = false, 6690 .ret_type = RET_INTEGER, 6691 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6692 .arg2_type = ARG_MEM_SIZE_OR_ZERO, 6693 .arg3_type = ARG_ANYTHING, 6694 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6695 .arg4_size = sizeof(u64), 6696 }; 6697 6698 static const struct bpf_func_proto * 6699 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6700 { 6701 switch (func_id) { 6702 case BPF_FUNC_sys_bpf: 6703 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6704 ? NULL : &bpf_sys_bpf_proto; 6705 case BPF_FUNC_btf_find_by_name_kind: 6706 return &bpf_btf_find_by_name_kind_proto; 6707 case BPF_FUNC_sys_close: 6708 return &bpf_sys_close_proto; 6709 case BPF_FUNC_kallsyms_lookup_name: 6710 return &bpf_kallsyms_lookup_name_proto; 6711 default: 6712 return tracing_prog_func_proto(func_id, prog); 6713 } 6714 } 6715 6716 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6717 .get_func_proto = syscall_prog_func_proto, 6718 .is_valid_access = syscall_prog_is_valid_access, 6719 }; 6720 6721 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6722 .test_run = bpf_prog_test_run_syscall, 6723 }; 6724 6725 #ifdef CONFIG_SYSCTL 6726 static int bpf_stats_handler(const struct ctl_table *table, int write, 6727 void *buffer, size_t *lenp, loff_t *ppos) 6728 { 6729 struct static_key *key = (struct static_key *)table->data; 6730 static int saved_val; 6731 int val, ret; 6732 struct ctl_table tmp = { 6733 .data = &val, 6734 .maxlen = sizeof(val), 6735 .mode = table->mode, 6736 .extra1 = SYSCTL_ZERO, 6737 .extra2 = SYSCTL_ONE, 6738 }; 6739 6740 if (write && !capable(CAP_SYS_ADMIN)) 6741 return -EPERM; 6742 6743 mutex_lock(&bpf_stats_enabled_mutex); 6744 val = saved_val; 6745 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6746 if (write && !ret && val != saved_val) { 6747 if (val) 6748 static_key_slow_inc(key); 6749 else 6750 static_key_slow_dec(key); 6751 saved_val = val; 6752 } 6753 mutex_unlock(&bpf_stats_enabled_mutex); 6754 return ret; 6755 } 6756 6757 void __weak unpriv_ebpf_notify(int new_state) 6758 { 6759 } 6760 6761 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6762 void *buffer, size_t *lenp, loff_t *ppos) 6763 { 6764 int ret, unpriv_enable = *(int *)table->data; 6765 bool locked_state = unpriv_enable == 1; 6766 struct ctl_table tmp = *table; 6767 6768 if (write && !capable(CAP_SYS_ADMIN)) 6769 return -EPERM; 6770 6771 tmp.data = &unpriv_enable; 6772 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6773 if (write && !ret) { 6774 if (locked_state && unpriv_enable != 1) 6775 return -EPERM; 6776 *(int *)table->data = unpriv_enable; 6777 } 6778 6779 if (write) 6780 unpriv_ebpf_notify(unpriv_enable); 6781 6782 return ret; 6783 } 6784 6785 static const struct ctl_table bpf_syscall_table[] = { 6786 { 6787 .procname = "unprivileged_bpf_disabled", 6788 .data = &sysctl_unprivileged_bpf_disabled, 6789 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6790 .mode = 0644, 6791 .proc_handler = bpf_unpriv_handler, 6792 .extra1 = SYSCTL_ZERO, 6793 .extra2 = SYSCTL_TWO, 6794 }, 6795 { 6796 .procname = "bpf_stats_enabled", 6797 .data = &bpf_stats_enabled_key.key, 6798 .mode = 0644, 6799 .proc_handler = bpf_stats_handler, 6800 }, 6801 }; 6802 6803 static int __init bpf_syscall_sysctl_init(void) 6804 { 6805 register_sysctl_init("kernel", bpf_syscall_table); 6806 return 0; 6807 } 6808 late_initcall(bpf_syscall_sysctl_init); 6809 #endif /* CONFIG_SYSCTL */ 6810