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->jited_linfo); 2465 kvfree(aux->linfo); 2466 kvfree(aux->func_info); 2467 kfree(aux->func_info_aux); 2468 free_uid(aux->user); 2469 security_bpf_prog_free(aux->prog); 2470 bpf_prog_free(aux->prog); 2471 } 2472 2473 /* 2474 * Progs called from a trampoline can also be reached by a task that was 2475 * preempted in the trampoline before the prog's enter helper took its RCU 2476 * read lock, wait for those first. 2477 */ 2478 static void __bpf_prog_put_rcu_tasks(struct rcu_head *rcu) 2479 { 2480 struct bpf_prog *prog = container_of(rcu, struct bpf_prog_aux, rcu)->prog; 2481 2482 if (bpf_prog_runs_sleepable(prog)) 2483 call_rcu_tasks_trace(rcu, __bpf_prog_put_rcu); 2484 else 2485 call_rcu(rcu, __bpf_prog_put_rcu); 2486 } 2487 2488 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2489 { 2490 module_put(prog->aux->mod); 2491 kfree(prog->aux->kfunc_tab); 2492 kfree(prog->aux->ctx_arg_info); 2493 if (prog->aux->attach_btf) 2494 btf_put(prog->aux->attach_btf); 2495 2496 if (deferred) { 2497 if (IS_ENABLED(CONFIG_TASKS_RCU) && prog->aux->tramp_linked) 2498 call_rcu_tasks(&prog->aux->rcu, __bpf_prog_put_rcu_tasks); 2499 else if (bpf_prog_runs_sleepable(prog)) 2500 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2501 else 2502 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2503 } else { 2504 __bpf_prog_put_rcu(&prog->aux->rcu); 2505 } 2506 } 2507 2508 static void bpf_prog_put_deferred(struct work_struct *work) 2509 { 2510 struct bpf_prog_aux *aux; 2511 struct bpf_prog *prog; 2512 2513 aux = container_of(work, struct bpf_prog_aux, work); 2514 prog = aux->prog; 2515 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2516 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2517 bpf_prog_free_id(prog); 2518 __bpf_prog_put_noref(prog, true); 2519 } 2520 2521 static void __bpf_prog_put(struct bpf_prog *prog) 2522 { 2523 struct bpf_prog_aux *aux = prog->aux; 2524 2525 if (atomic64_dec_and_test(&aux->refcnt)) { 2526 if (in_hardirq() || irqs_disabled()) { 2527 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2528 schedule_work(&aux->work); 2529 } else { 2530 bpf_prog_put_deferred(&aux->work); 2531 } 2532 } 2533 } 2534 2535 void bpf_prog_put(struct bpf_prog *prog) 2536 { 2537 __bpf_prog_put(prog); 2538 } 2539 EXPORT_SYMBOL_GPL(bpf_prog_put); 2540 2541 static int bpf_prog_release(struct inode *inode, struct file *filp) 2542 { 2543 struct bpf_prog *prog = filp->private_data; 2544 2545 bpf_prog_put(prog); 2546 return 0; 2547 } 2548 2549 struct bpf_prog_kstats { 2550 u64 nsecs; 2551 u64 cnt; 2552 u64 misses; 2553 }; 2554 2555 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2556 { 2557 struct bpf_prog_stats *stats; 2558 unsigned int flags; 2559 2560 if (unlikely(!prog->stats)) 2561 return; 2562 2563 stats = this_cpu_ptr(prog->stats); 2564 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2565 u64_stats_inc(&stats->misses); 2566 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2567 } 2568 2569 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2570 struct bpf_prog_kstats *stats) 2571 { 2572 u64 nsecs = 0, cnt = 0, misses = 0; 2573 int cpu; 2574 2575 for_each_possible_cpu(cpu) { 2576 const struct bpf_prog_stats *st; 2577 unsigned int start; 2578 u64 tnsecs, tcnt, tmisses; 2579 2580 st = per_cpu_ptr(prog->stats, cpu); 2581 do { 2582 start = u64_stats_fetch_begin(&st->syncp); 2583 tnsecs = u64_stats_read(&st->nsecs); 2584 tcnt = u64_stats_read(&st->cnt); 2585 tmisses = u64_stats_read(&st->misses); 2586 } while (u64_stats_fetch_retry(&st->syncp, start)); 2587 nsecs += tnsecs; 2588 cnt += tcnt; 2589 misses += tmisses; 2590 } 2591 stats->nsecs = nsecs; 2592 stats->cnt = cnt; 2593 stats->misses = misses; 2594 } 2595 2596 #ifdef CONFIG_PROC_FS 2597 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2598 { 2599 const struct bpf_prog *prog = filp->private_data; 2600 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2601 struct bpf_prog_kstats stats; 2602 2603 bpf_prog_get_stats(prog, &stats); 2604 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2605 seq_printf(m, 2606 "prog_type:\t%u\n" 2607 "prog_jited:\t%u\n" 2608 "prog_tag:\t%s\n" 2609 "memlock:\t%llu\n" 2610 "prog_id:\t%u\n" 2611 "run_time_ns:\t%llu\n" 2612 "run_cnt:\t%llu\n" 2613 "recursion_misses:\t%llu\n" 2614 "verified_insns:\t%u\n", 2615 prog->type, 2616 prog->jited, 2617 prog_tag, 2618 prog->pages * 1ULL << PAGE_SHIFT, 2619 prog->aux->id, 2620 stats.nsecs, 2621 stats.cnt, 2622 stats.misses, 2623 prog->aux->verified_insns); 2624 } 2625 #endif 2626 2627 const struct file_operations bpf_prog_fops = { 2628 #ifdef CONFIG_PROC_FS 2629 .show_fdinfo = bpf_prog_show_fdinfo, 2630 #endif 2631 .release = bpf_prog_release, 2632 .read = bpf_dummy_read, 2633 .write = bpf_dummy_write, 2634 }; 2635 2636 int bpf_prog_new_fd(struct bpf_prog *prog) 2637 { 2638 int ret; 2639 2640 ret = security_bpf_prog(prog); 2641 if (ret < 0) 2642 return ret; 2643 2644 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2645 O_RDWR | O_CLOEXEC); 2646 } 2647 2648 void bpf_prog_add(struct bpf_prog *prog, int i) 2649 { 2650 atomic64_add(i, &prog->aux->refcnt); 2651 } 2652 EXPORT_SYMBOL_GPL(bpf_prog_add); 2653 2654 void bpf_prog_sub(struct bpf_prog *prog, int i) 2655 { 2656 /* Only to be used for undoing previous bpf_prog_add() in some 2657 * error path. We still know that another entity in our call 2658 * path holds a reference to the program, thus atomic_sub() can 2659 * be safely used in such cases! 2660 */ 2661 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2662 } 2663 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2664 2665 void bpf_prog_inc(struct bpf_prog *prog) 2666 { 2667 atomic64_inc(&prog->aux->refcnt); 2668 } 2669 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2670 2671 /* prog_idr_lock should have been held */ 2672 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2673 { 2674 int refold; 2675 2676 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2677 2678 if (!refold) 2679 return ERR_PTR(-ENOENT); 2680 2681 return prog; 2682 } 2683 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2684 2685 bool bpf_prog_get_ok(struct bpf_prog *prog, 2686 enum bpf_prog_type *attach_type, bool attach_drv) 2687 { 2688 /* not an attachment, just a refcount inc, always allow */ 2689 if (!attach_type) 2690 return true; 2691 2692 if (prog->type != *attach_type) 2693 return false; 2694 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2695 return false; 2696 2697 return true; 2698 } 2699 2700 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2701 bool attach_drv) 2702 { 2703 CLASS(fd, f)(ufd); 2704 struct bpf_prog *prog; 2705 2706 if (fd_empty(f)) 2707 return ERR_PTR(-EBADF); 2708 if (fd_file(f)->f_op != &bpf_prog_fops) 2709 return ERR_PTR(-EINVAL); 2710 2711 prog = fd_file(f)->private_data; 2712 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2713 return ERR_PTR(-EINVAL); 2714 2715 bpf_prog_inc(prog); 2716 return prog; 2717 } 2718 2719 struct bpf_prog *bpf_prog_get(u32 ufd) 2720 { 2721 return __bpf_prog_get(ufd, NULL, false); 2722 } 2723 2724 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2725 bool attach_drv) 2726 { 2727 return __bpf_prog_get(ufd, &type, attach_drv); 2728 } 2729 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2730 2731 /* Initially all BPF programs could be loaded w/o specifying 2732 * expected_attach_type. Later for some of them specifying expected_attach_type 2733 * at load time became required so that program could be validated properly. 2734 * Programs of types that are allowed to be loaded both w/ and w/o (for 2735 * backward compatibility) expected_attach_type, should have the default attach 2736 * type assigned to expected_attach_type for the latter case, so that it can be 2737 * validated later at attach time. 2738 * 2739 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2740 * prog type requires it but has some attach types that have to be backward 2741 * compatible. 2742 */ 2743 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2744 { 2745 switch (attr->prog_type) { 2746 case BPF_PROG_TYPE_CGROUP_SOCK: 2747 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2748 * exist so checking for non-zero is the way to go here. 2749 */ 2750 if (!attr->expected_attach_type) 2751 attr->expected_attach_type = 2752 BPF_CGROUP_INET_SOCK_CREATE; 2753 break; 2754 case BPF_PROG_TYPE_SK_REUSEPORT: 2755 if (!attr->expected_attach_type) 2756 attr->expected_attach_type = 2757 BPF_SK_REUSEPORT_SELECT; 2758 break; 2759 } 2760 } 2761 2762 static int 2763 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2764 enum bpf_attach_type expected_attach_type, 2765 struct btf *attach_btf, u32 btf_id, 2766 struct bpf_prog *dst_prog, 2767 bool multi_func) 2768 { 2769 if (btf_id) { 2770 if (btf_id > BTF_MAX_TYPE) 2771 return -EINVAL; 2772 2773 if (!attach_btf && !dst_prog) 2774 return -EINVAL; 2775 2776 switch (prog_type) { 2777 case BPF_PROG_TYPE_TRACING: 2778 case BPF_PROG_TYPE_LSM: 2779 case BPF_PROG_TYPE_STRUCT_OPS: 2780 case BPF_PROG_TYPE_EXT: 2781 break; 2782 default: 2783 return -EINVAL; 2784 } 2785 } 2786 2787 if (multi_func) { 2788 if (prog_type != BPF_PROG_TYPE_TRACING) 2789 return -EINVAL; 2790 if (!attach_btf || btf_id) 2791 return -EINVAL; 2792 return 0; 2793 } 2794 2795 if (attach_btf && (!btf_id || dst_prog)) 2796 return -EINVAL; 2797 2798 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2799 prog_type != BPF_PROG_TYPE_EXT) 2800 return -EINVAL; 2801 2802 switch (prog_type) { 2803 case BPF_PROG_TYPE_CGROUP_SOCK: 2804 switch (expected_attach_type) { 2805 case BPF_CGROUP_INET_SOCK_CREATE: 2806 case BPF_CGROUP_INET_SOCK_RELEASE: 2807 case BPF_CGROUP_INET4_POST_BIND: 2808 case BPF_CGROUP_INET6_POST_BIND: 2809 return 0; 2810 default: 2811 return -EINVAL; 2812 } 2813 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2814 switch (expected_attach_type) { 2815 case BPF_CGROUP_INET4_BIND: 2816 case BPF_CGROUP_INET6_BIND: 2817 case BPF_CGROUP_INET4_CONNECT: 2818 case BPF_CGROUP_INET6_CONNECT: 2819 case BPF_CGROUP_UNIX_CONNECT: 2820 case BPF_CGROUP_INET4_GETPEERNAME: 2821 case BPF_CGROUP_INET6_GETPEERNAME: 2822 case BPF_CGROUP_UNIX_GETPEERNAME: 2823 case BPF_CGROUP_INET4_GETSOCKNAME: 2824 case BPF_CGROUP_INET6_GETSOCKNAME: 2825 case BPF_CGROUP_UNIX_GETSOCKNAME: 2826 case BPF_CGROUP_UDP4_SENDMSG: 2827 case BPF_CGROUP_UDP6_SENDMSG: 2828 case BPF_CGROUP_UNIX_SENDMSG: 2829 case BPF_CGROUP_UDP4_RECVMSG: 2830 case BPF_CGROUP_UDP6_RECVMSG: 2831 case BPF_CGROUP_UNIX_RECVMSG: 2832 return 0; 2833 default: 2834 return -EINVAL; 2835 } 2836 case BPF_PROG_TYPE_CGROUP_SKB: 2837 switch (expected_attach_type) { 2838 case BPF_CGROUP_INET_INGRESS: 2839 case BPF_CGROUP_INET_EGRESS: 2840 return 0; 2841 default: 2842 return -EINVAL; 2843 } 2844 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2845 switch (expected_attach_type) { 2846 case BPF_CGROUP_SETSOCKOPT: 2847 case BPF_CGROUP_GETSOCKOPT: 2848 return 0; 2849 default: 2850 return -EINVAL; 2851 } 2852 case BPF_PROG_TYPE_SK_LOOKUP: 2853 if (expected_attach_type == BPF_SK_LOOKUP) 2854 return 0; 2855 return -EINVAL; 2856 case BPF_PROG_TYPE_SK_REUSEPORT: 2857 switch (expected_attach_type) { 2858 case BPF_SK_REUSEPORT_SELECT: 2859 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2860 return 0; 2861 default: 2862 return -EINVAL; 2863 } 2864 case BPF_PROG_TYPE_NETFILTER: 2865 if (expected_attach_type == BPF_NETFILTER) 2866 return 0; 2867 return -EINVAL; 2868 case BPF_PROG_TYPE_SYSCALL: 2869 case BPF_PROG_TYPE_EXT: 2870 if (expected_attach_type) 2871 return -EINVAL; 2872 fallthrough; 2873 default: 2874 return 0; 2875 } 2876 } 2877 2878 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2879 { 2880 switch (prog_type) { 2881 case BPF_PROG_TYPE_SCHED_CLS: 2882 case BPF_PROG_TYPE_SCHED_ACT: 2883 case BPF_PROG_TYPE_XDP: 2884 case BPF_PROG_TYPE_LWT_IN: 2885 case BPF_PROG_TYPE_LWT_OUT: 2886 case BPF_PROG_TYPE_LWT_XMIT: 2887 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2888 case BPF_PROG_TYPE_SK_SKB: 2889 case BPF_PROG_TYPE_SK_MSG: 2890 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2891 case BPF_PROG_TYPE_CGROUP_DEVICE: 2892 case BPF_PROG_TYPE_CGROUP_SOCK: 2893 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2894 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2895 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2896 case BPF_PROG_TYPE_SOCK_OPS: 2897 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2898 case BPF_PROG_TYPE_NETFILTER: 2899 return true; 2900 case BPF_PROG_TYPE_CGROUP_SKB: 2901 /* always unpriv */ 2902 case BPF_PROG_TYPE_SK_REUSEPORT: 2903 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2904 default: 2905 return false; 2906 } 2907 } 2908 2909 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2910 { 2911 switch (prog_type) { 2912 case BPF_PROG_TYPE_KPROBE: 2913 case BPF_PROG_TYPE_TRACEPOINT: 2914 case BPF_PROG_TYPE_PERF_EVENT: 2915 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2916 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2917 case BPF_PROG_TYPE_TRACING: 2918 case BPF_PROG_TYPE_LSM: 2919 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2920 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2921 return true; 2922 default: 2923 return false; 2924 } 2925 } 2926 2927 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) 2928 { 2929 int err; 2930 int i; 2931 2932 for (i = 0; i < prog->aux->used_map_cnt; i++) { 2933 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY) 2934 continue; 2935 2936 err = bpf_insn_array_ready(prog->aux->used_maps[i]); 2937 if (err) 2938 return err; 2939 } 2940 2941 return 0; 2942 } 2943 2944 extern int bpf_multi_func(void); 2945 int __init __used bpf_multi_func(void) { return 0; } 2946 2947 BTF_ID_LIST_GLOBAL_SINGLE(bpf_multi_func_btf_id, func, bpf_multi_func) 2948 2949 /* last field in 'union bpf_attr' used by this command */ 2950 #define BPF_PROG_LOAD_LAST_FIELD keyring_id 2951 2952 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 2953 { 2954 enum bpf_prog_type type = attr->prog_type; 2955 struct bpf_prog *prog, *dst_prog = NULL; 2956 struct btf *attach_btf = NULL; 2957 struct bpf_token *token = NULL; 2958 bool bpf_cap; 2959 int err; 2960 char license[128]; 2961 bool multi_func; 2962 2963 if (CHECK_ATTR(BPF_PROG_LOAD)) 2964 return -EINVAL; 2965 2966 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2967 BPF_F_ANY_ALIGNMENT | 2968 BPF_F_TEST_STATE_FREQ | 2969 BPF_F_SLEEPABLE | 2970 BPF_F_TEST_RND_HI32 | 2971 BPF_F_XDP_HAS_FRAGS | 2972 BPF_F_XDP_DEV_BOUND_ONLY | 2973 BPF_F_TEST_REG_INVARIANTS | 2974 BPF_F_TOKEN_FD)) 2975 return -EINVAL; 2976 2977 bpf_prog_load_fixup_attach_type(attr); 2978 2979 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2980 token = bpf_token_get_from_fd(attr->prog_token_fd); 2981 if (IS_ERR(token)) 2982 return PTR_ERR(token); 2983 /* if current token doesn't grant prog loading permissions, 2984 * then we can't use this token, so ignore it and rely on 2985 * system-wide capabilities checks 2986 */ 2987 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2988 !bpf_token_allow_prog_type(token, attr->prog_type, 2989 attr->expected_attach_type)) { 2990 bpf_token_put(token); 2991 token = NULL; 2992 } 2993 } 2994 2995 bpf_cap = bpf_token_capable(token, CAP_BPF); 2996 err = -EPERM; 2997 2998 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2999 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 3000 !bpf_cap) 3001 goto put_token; 3002 3003 /* Intent here is for unprivileged_bpf_disabled to block BPF program 3004 * creation for unprivileged users; other actions depend 3005 * on fd availability and access to bpffs, so are dependent on 3006 * object creation success. Even with unprivileged BPF disabled, 3007 * capability checks are still carried out for these 3008 * and other operations. 3009 */ 3010 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 3011 goto put_token; 3012 3013 if (attr->insn_cnt == 0 || 3014 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 3015 err = -E2BIG; 3016 goto put_token; 3017 } 3018 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 3019 type != BPF_PROG_TYPE_CGROUP_SKB && 3020 !bpf_cap) 3021 goto put_token; 3022 3023 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 3024 goto put_token; 3025 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 3026 goto put_token; 3027 3028 multi_func = is_tracing_multi(attr->expected_attach_type); 3029 3030 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 3031 * or btf, we need to check which one it is 3032 */ 3033 if (attr->attach_prog_fd) { 3034 dst_prog = bpf_prog_get(attr->attach_prog_fd); 3035 if (IS_ERR(dst_prog)) { 3036 dst_prog = NULL; 3037 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 3038 if (IS_ERR(attach_btf)) { 3039 err = -EINVAL; 3040 goto put_token; 3041 } 3042 if (!btf_is_kernel(attach_btf)) { 3043 /* attaching through specifying bpf_prog's BTF 3044 * objects directly might be supported eventually 3045 */ 3046 btf_put(attach_btf); 3047 err = -ENOTSUPP; 3048 goto put_token; 3049 } 3050 } 3051 } else if (attr->attach_btf_id || multi_func) { 3052 /* fall back to vmlinux BTF, if BTF type ID is specified */ 3053 attach_btf = bpf_get_btf_vmlinux(); 3054 if (IS_ERR(attach_btf)) { 3055 err = PTR_ERR(attach_btf); 3056 goto put_token; 3057 } 3058 if (!attach_btf) { 3059 err = -EINVAL; 3060 goto put_token; 3061 } 3062 btf_get(attach_btf); 3063 } 3064 3065 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 3066 attach_btf, attr->attach_btf_id, 3067 dst_prog, multi_func)) { 3068 if (dst_prog) 3069 bpf_prog_put(dst_prog); 3070 if (attach_btf) 3071 btf_put(attach_btf); 3072 err = -EINVAL; 3073 goto put_token; 3074 } 3075 3076 /* plain bpf_prog allocation */ 3077 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 3078 if (!prog) { 3079 if (dst_prog) 3080 bpf_prog_put(dst_prog); 3081 if (attach_btf) 3082 btf_put(attach_btf); 3083 err = -EINVAL; 3084 goto put_token; 3085 } 3086 3087 prog->expected_attach_type = attr->expected_attach_type; 3088 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 3089 prog->aux->attach_btf = attach_btf; 3090 prog->aux->attach_btf_id = multi_func ? bpf_multi_func_btf_id[0] : attr->attach_btf_id; 3091 prog->aux->dst_prog = dst_prog; 3092 if (dst_prog) { 3093 prog->aux->saved_dst_prog_type = dst_prog->type; 3094 prog->aux->saved_dst_attach_type = dst_prog->expected_attach_type; 3095 } 3096 prog->aux->dev_bound = !!attr->prog_ifindex; 3097 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 3098 3099 /* move token into prog->aux, reuse taken refcnt */ 3100 prog->aux->token = token; 3101 token = NULL; 3102 3103 prog->aux->user = get_current_user(); 3104 prog->len = attr->insn_cnt; 3105 3106 err = bpf_prog_stream_init(prog, GFP_USER); 3107 if (err) 3108 goto free_prog; 3109 3110 err = -EFAULT; 3111 if (copy_from_bpfptr(prog->insns, 3112 make_bpfptr(attr->insns, uattr.is_kernel), 3113 bpf_prog_insn_size(prog)) != 0) 3114 goto free_prog; 3115 /* copy eBPF program license from user space */ 3116 if (strncpy_from_bpfptr(license, 3117 make_bpfptr(attr->license, uattr.is_kernel), 3118 sizeof(license) - 1) < 0) 3119 goto free_prog; 3120 license[sizeof(license) - 1] = 0; 3121 3122 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 3123 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 3124 prog->aux->sig.keyring_type = BPF_SIG_KEYRING_NONE; 3125 prog->aux->sig.verdict = BPF_SIG_UNSIGNED; 3126 prog->orig_prog = NULL; 3127 prog->jited = 0; 3128 3129 atomic64_set(&prog->aux->refcnt, 1); 3130 3131 if (bpf_prog_is_dev_bound(prog->aux)) { 3132 err = bpf_prog_dev_bound_init(prog, attr); 3133 if (err) 3134 goto free_prog; 3135 } 3136 3137 if (type == BPF_PROG_TYPE_EXT && dst_prog && 3138 bpf_prog_is_dev_bound(dst_prog->aux)) { 3139 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 3140 if (err) 3141 goto free_prog; 3142 } 3143 3144 /* 3145 * Bookkeeping for managing the program attachment chain. 3146 * 3147 * It might be tempting to set attach_tracing_prog flag at the attachment 3148 * time, but this will not prevent from loading bunch of tracing prog 3149 * first, then attach them one to another. 3150 * 3151 * The flag attach_tracing_prog is set for the whole program lifecycle, and 3152 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 3153 * programs cannot change attachment target. 3154 */ 3155 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 3156 dst_prog->type == BPF_PROG_TYPE_TRACING) { 3157 prog->aux->attach_tracing_prog = true; 3158 } 3159 3160 /* find program type: socket_filter vs tracing_filter */ 3161 err = find_prog_type(type, prog); 3162 if (err < 0) 3163 goto free_prog; 3164 3165 prog->aux->load_time = ktime_get_boottime_ns(); 3166 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 3167 sizeof(attr->prog_name)); 3168 if (err < 0) 3169 goto free_prog; 3170 3171 /* run eBPF verifier */ 3172 err = bpf_check(&prog, attr, uattr, attr_log); 3173 if (err < 0) 3174 goto free_used_maps; 3175 3176 err = bpf_prog_mark_insn_arrays_ready(prog); 3177 if (err < 0) 3178 goto free_used_maps; 3179 3180 err = bpf_prog_alloc_id(prog); 3181 if (err) 3182 goto free_used_maps; 3183 3184 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 3185 * effectively publicly exposed. However, retrieving via 3186 * bpf_prog_get_fd_by_id() will take another reference, 3187 * therefore it cannot be gone underneath us. 3188 * 3189 * Only for the time /after/ successful bpf_prog_new_fd() 3190 * and before returning to userspace, we might just hold 3191 * one reference and any parallel close on that fd could 3192 * rip everything out. Hence, below notifications must 3193 * happen before bpf_prog_new_fd(). 3194 * 3195 * Also, any failure handling from this point onwards must 3196 * be using bpf_prog_put() given the program is exposed. 3197 */ 3198 bpf_prog_kallsyms_add(prog); 3199 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 3200 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 3201 3202 err = bpf_prog_new_fd(prog); 3203 if (err < 0) 3204 bpf_prog_put(prog); 3205 return err; 3206 3207 free_used_maps: 3208 /* In case we have subprogs, we need to wait for a grace 3209 * period before we can tear down JIT memory since symbols 3210 * are already exposed under kallsyms. 3211 */ 3212 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 3213 return err; 3214 3215 free_prog: 3216 free_uid(prog->aux->user); 3217 if (prog->aux->attach_btf) 3218 btf_put(prog->aux->attach_btf); 3219 bpf_prog_free(prog); 3220 put_token: 3221 bpf_token_put(token); 3222 return err; 3223 } 3224 3225 #define BPF_OBJ_LAST_FIELD path_fd 3226 3227 static int bpf_obj_pin(const union bpf_attr *attr) 3228 { 3229 int path_fd; 3230 3231 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3232 return -EINVAL; 3233 3234 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3235 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3236 return -EINVAL; 3237 3238 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3239 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3240 u64_to_user_ptr(attr->pathname)); 3241 } 3242 3243 static int bpf_obj_get(const union bpf_attr *attr) 3244 { 3245 int path_fd; 3246 3247 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3248 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3249 return -EINVAL; 3250 3251 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3252 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3253 return -EINVAL; 3254 3255 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3256 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3257 attr->file_flags); 3258 } 3259 3260 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3261 * "sleepable" semantics, which normally would mean that BPF link's attach 3262 * hook can dereference link or link's underlying program for some time after 3263 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3264 * BPF program itself can be non-sleepable, yet, because it's transitively 3265 * reachable through BPF link, its freeing has to be delayed until after RCU 3266 * Tasks Trace GP. 3267 */ 3268 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3269 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3270 enum bpf_attach_type attach_type, bool sleepable) 3271 { 3272 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3273 atomic64_set(&link->refcnt, 1); 3274 link->type = type; 3275 link->sleepable = sleepable; 3276 link->id = 0; 3277 link->ops = ops; 3278 link->prog = prog; 3279 link->attach_type = attach_type; 3280 } 3281 3282 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3283 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3284 enum bpf_attach_type attach_type) 3285 { 3286 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); 3287 } 3288 3289 void bpf_tramp_link_init(struct bpf_tramp_link *link, enum bpf_link_type type, 3290 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3291 enum bpf_attach_type attach_type, u64 cookie) 3292 { 3293 bpf_link_init(&link->link, type, ops, prog, attach_type); 3294 link->node.link = &link->link; 3295 link->node.cookie = cookie; 3296 } 3297 3298 static void bpf_link_free_id(int id) 3299 { 3300 if (!id) 3301 return; 3302 3303 spin_lock_bh(&link_idr_lock); 3304 idr_remove(&link_idr, id); 3305 spin_unlock_bh(&link_idr_lock); 3306 } 3307 3308 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3309 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3310 * anon_inode's release() call. This helper marks bpf_link as 3311 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3312 * is not decremented, it's the responsibility of a calling code that failed 3313 * to complete bpf_link initialization. 3314 * This helper eventually calls link's dealloc callback, but does not call 3315 * link's release callback. 3316 */ 3317 void bpf_link_cleanup(struct bpf_link_primer *primer) 3318 { 3319 primer->link->prog = NULL; 3320 bpf_link_free_id(primer->id); 3321 fput(primer->file); 3322 put_unused_fd(primer->fd); 3323 } 3324 3325 void bpf_link_inc(struct bpf_link *link) 3326 { 3327 atomic64_inc(&link->refcnt); 3328 } 3329 3330 static void bpf_link_dealloc(struct bpf_link *link) 3331 { 3332 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3333 if (link->prog) 3334 bpf_prog_put(link->prog); 3335 3336 /* free bpf_link and its containing memory */ 3337 if (link->ops->dealloc_deferred) 3338 link->ops->dealloc_deferred(link); 3339 else 3340 link->ops->dealloc(link); 3341 } 3342 3343 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3344 { 3345 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3346 3347 bpf_link_dealloc(link); 3348 } 3349 3350 static bool bpf_link_is_tracepoint(struct bpf_link *link) 3351 { 3352 /* 3353 * Only these combinations support a tracepoint bpf_link. 3354 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use 3355 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see 3356 * bpf_raw_tp_link_attach(). 3357 */ 3358 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT || 3359 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP); 3360 } 3361 3362 /* bpf_link_free is guaranteed to be called from process context */ 3363 static void bpf_link_free(struct bpf_link *link) 3364 { 3365 const struct bpf_link_ops *ops = link->ops; 3366 3367 bpf_link_free_id(link->id); 3368 /* detach BPF program, clean up used resources */ 3369 if (link->prog) 3370 ops->release(link); 3371 if (ops->dealloc_deferred) { 3372 /* 3373 * Schedule BPF link deallocation, which will only then 3374 * trigger putting BPF program refcount. 3375 * If underlying BPF program is sleepable or BPF link's target 3376 * attach hookpoint is sleepable or otherwise requires RCU GPs 3377 * to ensure link and its underlying BPF program is not 3378 * reachable anymore, we need to first wait for RCU tasks 3379 * trace sync, and then go through "classic" RCU grace period. 3380 * 3381 * For tracepoint BPF links, we need to go through SRCU grace 3382 * period wait instead when non-faultable tracepoint is used. We 3383 * don't need to chain SRCU grace period waits, however, for the 3384 * faultable case, since it exclusively uses RCU Tasks Trace. 3385 */ 3386 if (link->sleepable || (link->prog && link->prog->sleepable)) 3387 /* RCU Tasks Trace grace period implies RCU grace period. */ 3388 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3389 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */ 3390 else if (bpf_link_is_tracepoint(link)) 3391 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3392 else 3393 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3394 } else if (ops->dealloc) { 3395 bpf_link_dealloc(link); 3396 } 3397 } 3398 3399 static void bpf_link_put_deferred(struct work_struct *work) 3400 { 3401 struct bpf_link *link = container_of(work, struct bpf_link, work); 3402 3403 bpf_link_free(link); 3404 } 3405 3406 /* bpf_link_put might be called from atomic context. It needs to be called 3407 * from sleepable context in order to acquire sleeping locks during the process. 3408 */ 3409 void bpf_link_put(struct bpf_link *link) 3410 { 3411 if (!atomic64_dec_and_test(&link->refcnt)) 3412 return; 3413 3414 INIT_WORK(&link->work, bpf_link_put_deferred); 3415 schedule_work(&link->work); 3416 } 3417 EXPORT_SYMBOL(bpf_link_put); 3418 3419 static void bpf_link_put_direct(struct bpf_link *link) 3420 { 3421 if (!atomic64_dec_and_test(&link->refcnt)) 3422 return; 3423 bpf_link_free(link); 3424 } 3425 3426 static int bpf_link_release(struct inode *inode, struct file *filp) 3427 { 3428 struct bpf_link *link = filp->private_data; 3429 3430 bpf_link_put_direct(link); 3431 return 0; 3432 } 3433 3434 #ifdef CONFIG_PROC_FS 3435 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3436 #define BPF_MAP_TYPE(_id, _ops) 3437 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3438 static const char *bpf_link_type_strs[] = { 3439 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3440 #include <linux/bpf_types.h> 3441 }; 3442 #undef BPF_PROG_TYPE 3443 #undef BPF_MAP_TYPE 3444 #undef BPF_LINK_TYPE 3445 3446 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3447 { 3448 const struct bpf_link *link = filp->private_data; 3449 const struct bpf_prog *prog; 3450 enum bpf_link_type type = link->type; 3451 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3452 u32 prog_id = 0; 3453 3454 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3455 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) 3456 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? 3457 "kretprobe_multi" : "kprobe_multi"); 3458 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) 3459 seq_printf(m, "link_type:\t%s\n", link->flags & BPF_F_UPROBE_MULTI_RETURN ? 3460 "uretprobe_multi" : "uprobe_multi"); 3461 else 3462 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3463 } else { 3464 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3465 seq_printf(m, "link_type:\t<%u>\n", type); 3466 } 3467 seq_printf(m, "link_id:\t%u\n", link->id); 3468 3469 rcu_read_lock(); 3470 prog = READ_ONCE(link->prog); 3471 if (prog) { 3472 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3473 prog_id = prog->aux->id; 3474 } 3475 rcu_read_unlock(); 3476 3477 if (prog) { 3478 seq_printf(m, 3479 "prog_tag:\t%s\n" 3480 "prog_id:\t%u\n", 3481 prog_tag, 3482 prog_id); 3483 } 3484 if (link->ops->show_fdinfo) 3485 link->ops->show_fdinfo(link, m); 3486 } 3487 #endif 3488 3489 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3490 { 3491 struct bpf_link *link = file->private_data; 3492 3493 return link->ops->poll(file, pts); 3494 } 3495 3496 static const struct file_operations bpf_link_fops = { 3497 #ifdef CONFIG_PROC_FS 3498 .show_fdinfo = bpf_link_show_fdinfo, 3499 #endif 3500 .release = bpf_link_release, 3501 .read = bpf_dummy_read, 3502 .write = bpf_dummy_write, 3503 }; 3504 3505 static const struct file_operations bpf_link_fops_poll = { 3506 #ifdef CONFIG_PROC_FS 3507 .show_fdinfo = bpf_link_show_fdinfo, 3508 #endif 3509 .release = bpf_link_release, 3510 .read = bpf_dummy_read, 3511 .write = bpf_dummy_write, 3512 .poll = bpf_link_poll, 3513 }; 3514 3515 static int bpf_link_alloc_id(struct bpf_link *link) 3516 { 3517 int id; 3518 3519 idr_preload(GFP_KERNEL); 3520 spin_lock_bh(&link_idr_lock); 3521 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3522 spin_unlock_bh(&link_idr_lock); 3523 idr_preload_end(); 3524 3525 return id; 3526 } 3527 3528 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3529 * reserving unused FD and allocating ID from link_idr. This is to be paired 3530 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3531 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3532 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3533 * transient state is passed around in struct bpf_link_primer. 3534 * This is preferred way to create and initialize bpf_link, especially when 3535 * there are complicated and expensive operations in between creating bpf_link 3536 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3537 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3538 * expensive (and potentially failing) roll back operations in a rare case 3539 * that file, FD, or ID can't be allocated. 3540 */ 3541 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3542 { 3543 struct file *file; 3544 int fd, id; 3545 3546 fd = get_unused_fd_flags(O_CLOEXEC); 3547 if (fd < 0) 3548 return fd; 3549 3550 id = bpf_link_alloc_id(link); 3551 if (id < 0) { 3552 put_unused_fd(fd); 3553 return id; 3554 } 3555 3556 file = anon_inode_getfile("bpf_link", 3557 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3558 link, O_CLOEXEC); 3559 if (IS_ERR(file)) { 3560 bpf_link_free_id(id); 3561 put_unused_fd(fd); 3562 return PTR_ERR(file); 3563 } 3564 3565 primer->link = link; 3566 primer->file = file; 3567 primer->fd = fd; 3568 primer->id = id; 3569 return 0; 3570 } 3571 3572 int bpf_link_settle(struct bpf_link_primer *primer) 3573 { 3574 /* make bpf_link fetchable by ID */ 3575 spin_lock_bh(&link_idr_lock); 3576 primer->link->id = primer->id; 3577 spin_unlock_bh(&link_idr_lock); 3578 /* make bpf_link fetchable by FD */ 3579 fd_install(primer->fd, primer->file); 3580 /* pass through installed FD */ 3581 return primer->fd; 3582 } 3583 3584 int bpf_link_new_fd(struct bpf_link *link) 3585 { 3586 return anon_inode_getfd("bpf-link", 3587 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3588 link, O_CLOEXEC); 3589 } 3590 3591 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3592 { 3593 CLASS(fd, f)(ufd); 3594 struct bpf_link *link; 3595 3596 if (fd_empty(f)) 3597 return ERR_PTR(-EBADF); 3598 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3599 return ERR_PTR(-EINVAL); 3600 3601 link = fd_file(f)->private_data; 3602 bpf_link_inc(link); 3603 return link; 3604 } 3605 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); 3606 3607 static void bpf_tracing_link_release(struct bpf_link *link) 3608 { 3609 struct bpf_tracing_link *tr_link = 3610 container_of(link, struct bpf_tracing_link, link.link); 3611 int err; 3612 3613 err = bpf_trampoline_unlink_prog(&tr_link->link.node, 3614 tr_link->trampoline, 3615 tr_link->tgt_prog); 3616 WARN_ONCE(err, "bpf_trampoline_unlink_prog failed: %d\n", err); 3617 3618 bpf_trampoline_put(tr_link->trampoline); 3619 3620 /* tgt_prog is NULL if target is a kernel function */ 3621 if (tr_link->tgt_prog) 3622 bpf_prog_put(tr_link->tgt_prog); 3623 } 3624 3625 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3626 { 3627 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3628 3629 kfree(tr_link); 3630 } 3631 3632 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3633 struct seq_file *seq) 3634 { 3635 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3636 3637 u32 target_btf_id, target_obj_id; 3638 3639 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3640 &target_obj_id, &target_btf_id); 3641 seq_printf(seq, 3642 "attach_type:\t%d\n" 3643 "target_obj_id:\t%u\n" 3644 "target_btf_id:\t%u\n" 3645 "cookie:\t%llu\n", 3646 link->attach_type, 3647 target_obj_id, 3648 target_btf_id, 3649 tr_link->link.node.cookie); 3650 } 3651 3652 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3653 struct bpf_link_info *info) 3654 { 3655 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link); 3656 3657 info->tracing.attach_type = link->attach_type; 3658 info->tracing.cookie = tr_link->link.node.cookie; 3659 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3660 &info->tracing.target_obj_id, 3661 &info->tracing.target_btf_id); 3662 3663 return 0; 3664 } 3665 3666 static const struct bpf_link_ops bpf_tracing_link_lops = { 3667 .release = bpf_tracing_link_release, 3668 .dealloc = bpf_tracing_link_dealloc, 3669 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3670 .fill_link_info = bpf_tracing_link_fill_link_info, 3671 }; 3672 3673 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3674 int tgt_prog_fd, 3675 u32 btf_id, 3676 u64 bpf_cookie, 3677 enum bpf_attach_type attach_type) 3678 { 3679 struct bpf_link_primer link_primer; 3680 struct bpf_prog *tgt_prog = NULL; 3681 struct bpf_trampoline *tr = NULL; 3682 struct bpf_tracing_link *link; 3683 u64 key = 0; 3684 int err; 3685 3686 switch (prog->type) { 3687 case BPF_PROG_TYPE_TRACING: 3688 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3689 prog->expected_attach_type != BPF_TRACE_FEXIT && 3690 prog->expected_attach_type != BPF_TRACE_FSESSION && 3691 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3692 err = -EINVAL; 3693 goto out_put_prog; 3694 } 3695 break; 3696 case BPF_PROG_TYPE_EXT: 3697 if (prog->expected_attach_type != 0) { 3698 err = -EINVAL; 3699 goto out_put_prog; 3700 } 3701 break; 3702 case BPF_PROG_TYPE_LSM: 3703 if (prog->expected_attach_type != BPF_LSM_MAC) { 3704 err = -EINVAL; 3705 goto out_put_prog; 3706 } 3707 break; 3708 default: 3709 err = -EINVAL; 3710 goto out_put_prog; 3711 } 3712 3713 if (!!tgt_prog_fd != !!btf_id) { 3714 err = -EINVAL; 3715 goto out_put_prog; 3716 } 3717 3718 if (tgt_prog_fd) { 3719 /* 3720 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3721 * part would be changed to implement the same for 3722 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3723 * attach_tracing_prog flag is set. 3724 */ 3725 if (prog->type != BPF_PROG_TYPE_EXT) { 3726 err = -EINVAL; 3727 goto out_put_prog; 3728 } 3729 3730 tgt_prog = bpf_prog_get(tgt_prog_fd); 3731 if (IS_ERR(tgt_prog)) { 3732 err = PTR_ERR(tgt_prog); 3733 tgt_prog = NULL; 3734 goto out_put_prog; 3735 } 3736 3737 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3738 } 3739 3740 link = kzalloc_obj(*link, GFP_USER); 3741 if (!link) { 3742 err = -ENOMEM; 3743 goto out_put_prog; 3744 } 3745 bpf_tramp_link_init(&link->link, BPF_LINK_TYPE_TRACING, 3746 &bpf_tracing_link_lops, prog, attach_type, bpf_cookie); 3747 3748 if (prog->expected_attach_type == BPF_TRACE_FSESSION) { 3749 link->fexit.link = &link->link.link; 3750 link->fexit.cookie = bpf_cookie; 3751 } 3752 3753 mutex_lock(&prog->aux->dst_mutex); 3754 3755 /* There are a few possible cases here: 3756 * 3757 * - if prog->aux->dst_trampoline is set, the program was just loaded 3758 * and not yet attached to anything, so we can use the values stored 3759 * in prog->aux 3760 * 3761 * - if prog->aux->dst_trampoline is NULL, the program has already been 3762 * attached to a target and its initial target was cleared (below) 3763 * 3764 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3765 * target_btf_id using the link_create API. 3766 * 3767 * - if tgt_prog == NULL when this function was called using the old 3768 * raw_tracepoint_open API, and we need a target from prog->aux 3769 * 3770 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3771 * was detached and is going for re-attachment. 3772 * 3773 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3774 * are NULL, then program was already attached and user did not provide 3775 * tgt_prog_fd so we have no way to find out or create trampoline 3776 */ 3777 if (!prog->aux->dst_trampoline && !tgt_prog) { 3778 /* 3779 * Allow re-attach for TRACING and LSM programs. If it's 3780 * currently linked, bpf_trampoline_link_prog will fail. 3781 * EXT programs need to specify tgt_prog_fd, so they 3782 * re-attach in separate code path. 3783 */ 3784 if (prog->type != BPF_PROG_TYPE_TRACING && 3785 prog->type != BPF_PROG_TYPE_LSM) { 3786 err = -EINVAL; 3787 goto out_unlock; 3788 } 3789 /* We can allow re-attach only if we have valid attach_btf. */ 3790 if (!prog->aux->attach_btf) { 3791 err = -EINVAL; 3792 goto out_unlock; 3793 } 3794 btf_id = prog->aux->attach_btf_id; 3795 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3796 } 3797 3798 if (!prog->aux->dst_trampoline || 3799 (key && key != prog->aux->dst_trampoline->key)) { 3800 /* If there is no saved target, or the specified target is 3801 * different from the destination specified at load time, we 3802 * need a new trampoline and a check for compatibility 3803 */ 3804 struct bpf_attach_target_info tgt_info = {}; 3805 3806 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3807 &tgt_info); 3808 if (err) 3809 goto out_unlock; 3810 3811 if (tgt_info.tgt_mod) { 3812 module_put(prog->aux->mod); 3813 prog->aux->mod = tgt_info.tgt_mod; 3814 } 3815 3816 tr = bpf_trampoline_get(key, &tgt_info); 3817 if (!tr) { 3818 err = -ENOMEM; 3819 goto out_unlock; 3820 } 3821 } else { 3822 /* The caller didn't specify a target, or the target was the 3823 * same as the destination supplied during program load. This 3824 * means we can reuse the trampoline and reference from program 3825 * load time, and there is no need to allocate a new one. This 3826 * can only happen once for any program, as the saved values in 3827 * prog->aux are cleared below. 3828 */ 3829 tr = prog->aux->dst_trampoline; 3830 tgt_prog = prog->aux->dst_prog; 3831 } 3832 /* 3833 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true 3834 * freplace prog. Without this check, kprobe_write_ctx=true freplace 3835 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and 3836 * then modify the registers of the kprobe prog's target kernel 3837 * function. 3838 * 3839 * This also blocks the combination of uprobe+freplace, because it is 3840 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe 3841 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by 3842 * the target perf event flags in __perf_event_set_bpf_prog(). 3843 */ 3844 if (prog->type == BPF_PROG_TYPE_EXT && 3845 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) { 3846 err = -EINVAL; 3847 goto out_unlock; 3848 } 3849 /* 3850 * The size of these contexts depends on what the program is attached 3851 * to, or run with. That is compared with max_ctx_offset of the program, 3852 * and nobody looks at the one of its extensions. 3853 */ 3854 if (prog->type == BPF_PROG_TYPE_EXT && 3855 (tgt_prog->type == BPF_PROG_TYPE_RAW_TRACEPOINT || 3856 tgt_prog->type == BPF_PROG_TYPE_TRACEPOINT || 3857 tgt_prog->type == BPF_PROG_TYPE_SYSCALL) && 3858 prog->aux->max_ctx_offset > tgt_prog->aux->max_ctx_offset) { 3859 err = -EINVAL; 3860 goto out_unlock; 3861 } 3862 3863 err = bpf_link_prime(&link->link.link, &link_primer); 3864 if (err) 3865 goto out_unlock; 3866 3867 err = bpf_trampoline_link_prog(&link->link.node, tr, tgt_prog); 3868 if (err) { 3869 bpf_link_cleanup(&link_primer); 3870 link = NULL; 3871 goto out_unlock; 3872 } 3873 3874 link->tgt_prog = tgt_prog; 3875 link->trampoline = tr; 3876 3877 /* Always clear the trampoline and target prog from prog->aux to make 3878 * sure the original attach destination is not kept alive after a 3879 * program is (re-)attached to another target. 3880 */ 3881 if (prog->aux->dst_prog && 3882 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3883 /* got extra prog ref from syscall, or attaching to different prog */ 3884 bpf_prog_put(prog->aux->dst_prog); 3885 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3886 /* we allocated a new trampoline, so free the old one */ 3887 bpf_trampoline_put(prog->aux->dst_trampoline); 3888 3889 prog->aux->dst_prog = NULL; 3890 prog->aux->dst_trampoline = NULL; 3891 mutex_unlock(&prog->aux->dst_mutex); 3892 3893 return bpf_link_settle(&link_primer); 3894 out_unlock: 3895 if (tr && tr != prog->aux->dst_trampoline) 3896 bpf_trampoline_put(tr); 3897 mutex_unlock(&prog->aux->dst_mutex); 3898 kfree(link); 3899 out_put_prog: 3900 if (tgt_prog_fd && tgt_prog) 3901 bpf_prog_put(tgt_prog); 3902 return err; 3903 } 3904 3905 static void bpf_raw_tp_link_release(struct bpf_link *link) 3906 { 3907 struct bpf_raw_tp_link *raw_tp = 3908 container_of(link, struct bpf_raw_tp_link, link); 3909 3910 bpf_probe_unregister(raw_tp->btp, raw_tp); 3911 bpf_put_raw_tracepoint(raw_tp->btp); 3912 } 3913 3914 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3915 { 3916 struct bpf_raw_tp_link *raw_tp = 3917 container_of(link, struct bpf_raw_tp_link, link); 3918 3919 kfree(raw_tp); 3920 } 3921 3922 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3923 struct seq_file *seq) 3924 { 3925 struct bpf_raw_tp_link *raw_tp_link = 3926 container_of(link, struct bpf_raw_tp_link, link); 3927 3928 seq_printf(seq, 3929 "tp_name:\t%s\n" 3930 "cookie:\t%llu\n", 3931 raw_tp_link->btp->tp->name, 3932 raw_tp_link->cookie); 3933 } 3934 3935 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3936 u32 len) 3937 { 3938 if (ulen >= len + 1) { 3939 if (copy_to_user(ubuf, buf, len + 1)) 3940 return -EFAULT; 3941 } else { 3942 char zero = '\0'; 3943 3944 if (copy_to_user(ubuf, buf, ulen - 1)) 3945 return -EFAULT; 3946 if (put_user(zero, ubuf + ulen - 1)) 3947 return -EFAULT; 3948 return -ENOSPC; 3949 } 3950 3951 return 0; 3952 } 3953 3954 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3955 struct bpf_link_info *info) 3956 { 3957 struct bpf_raw_tp_link *raw_tp_link = 3958 container_of(link, struct bpf_raw_tp_link, link); 3959 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3960 const char *tp_name = raw_tp_link->btp->tp->name; 3961 u32 ulen = info->raw_tracepoint.tp_name_len; 3962 size_t tp_len = strlen(tp_name); 3963 3964 if (!ulen ^ !ubuf) 3965 return -EINVAL; 3966 3967 info->raw_tracepoint.tp_name_len = tp_len + 1; 3968 info->raw_tracepoint.cookie = raw_tp_link->cookie; 3969 3970 if (!ubuf) 3971 return 0; 3972 3973 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3974 } 3975 3976 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3977 .release = bpf_raw_tp_link_release, 3978 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3979 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3980 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3981 }; 3982 3983 #ifdef CONFIG_PERF_EVENTS 3984 struct bpf_perf_link { 3985 struct bpf_link link; 3986 struct file *perf_file; 3987 }; 3988 3989 static void bpf_perf_link_release(struct bpf_link *link) 3990 { 3991 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3992 struct perf_event *event = perf_link->perf_file->private_data; 3993 3994 perf_event_free_bpf_prog(event); 3995 fput(perf_link->perf_file); 3996 } 3997 3998 static void bpf_perf_link_dealloc(struct bpf_link *link) 3999 { 4000 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 4001 4002 kfree(perf_link); 4003 } 4004 4005 static int bpf_perf_link_fill_common(const struct perf_event *event, 4006 char __user *uname, u32 *ulenp, 4007 u64 *probe_offset, u64 *probe_addr, 4008 u32 *fd_type, unsigned long *missed) 4009 { 4010 const char *buf; 4011 u32 prog_id, ulen; 4012 size_t len; 4013 int err; 4014 4015 ulen = *ulenp; 4016 if (!ulen ^ !uname) 4017 return -EINVAL; 4018 4019 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 4020 probe_offset, probe_addr, missed); 4021 if (err) 4022 return err; 4023 4024 if (buf) { 4025 len = strlen(buf); 4026 *ulenp = len + 1; 4027 } else { 4028 *ulenp = 1; 4029 } 4030 if (!uname) 4031 goto out; 4032 4033 if (buf) { 4034 err = bpf_copy_to_user(uname, buf, ulen, len); 4035 } else { 4036 char zero = '\0'; 4037 4038 if (put_user(zero, uname)) 4039 err = -EFAULT; 4040 } 4041 out: 4042 kfree_const(buf); 4043 return err; 4044 } 4045 4046 #ifdef CONFIG_KPROBE_EVENTS 4047 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 4048 struct bpf_link_info *info) 4049 { 4050 unsigned long missed; 4051 char __user *uname; 4052 u64 addr, offset; 4053 u32 ulen, type; 4054 int err; 4055 4056 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 4057 ulen = info->perf_event.kprobe.name_len; 4058 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 4059 &type, &missed); 4060 if (err) 4061 return err; 4062 if (type == BPF_FD_TYPE_KRETPROBE) 4063 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 4064 else 4065 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 4066 info->perf_event.kprobe.name_len = ulen; 4067 info->perf_event.kprobe.offset = offset; 4068 info->perf_event.kprobe.missed = missed; 4069 if (!kallsyms_show_value(current_cred())) 4070 addr = 0; 4071 info->perf_event.kprobe.addr = addr; 4072 info->perf_event.kprobe.cookie = event->bpf_cookie; 4073 return 0; 4074 } 4075 4076 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, 4077 struct seq_file *seq) 4078 { 4079 const char *name; 4080 int err; 4081 u32 prog_id, type; 4082 u64 offset, addr; 4083 unsigned long missed; 4084 4085 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4086 &offset, &addr, &missed); 4087 if (err) 4088 return; 4089 4090 seq_printf(seq, 4091 "name:\t%s\n" 4092 "offset:\t%#llx\n" 4093 "missed:\t%lu\n" 4094 "addr:\t%#llx\n" 4095 "event_type:\t%s\n" 4096 "cookie:\t%llu\n", 4097 name, offset, missed, addr, 4098 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", 4099 event->bpf_cookie); 4100 kfree_const(name); 4101 } 4102 #endif 4103 4104 #ifdef CONFIG_UPROBE_EVENTS 4105 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 4106 struct bpf_link_info *info) 4107 { 4108 u64 ref_ctr_offset, offset; 4109 char __user *uname; 4110 u32 ulen, type; 4111 int err; 4112 4113 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 4114 ulen = info->perf_event.uprobe.name_len; 4115 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, 4116 &type, NULL); 4117 if (err) 4118 return err; 4119 4120 if (type == BPF_FD_TYPE_URETPROBE) 4121 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 4122 else 4123 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 4124 info->perf_event.uprobe.name_len = ulen; 4125 info->perf_event.uprobe.offset = offset; 4126 info->perf_event.uprobe.cookie = event->bpf_cookie; 4127 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; 4128 return 0; 4129 } 4130 4131 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, 4132 struct seq_file *seq) 4133 { 4134 const char *name; 4135 int err; 4136 u32 prog_id, type; 4137 u64 offset, ref_ctr_offset; 4138 unsigned long missed; 4139 4140 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4141 &offset, &ref_ctr_offset, &missed); 4142 if (err) 4143 return; 4144 4145 seq_printf(seq, 4146 "name:\t%s\n" 4147 "offset:\t%#llx\n" 4148 "ref_ctr_offset:\t%#llx\n" 4149 "event_type:\t%s\n" 4150 "cookie:\t%llu\n", 4151 name, offset, ref_ctr_offset, 4152 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", 4153 event->bpf_cookie); 4154 kfree_const(name); 4155 } 4156 #endif 4157 4158 static int bpf_perf_link_fill_probe(const struct perf_event *event, 4159 struct bpf_link_info *info) 4160 { 4161 #ifdef CONFIG_KPROBE_EVENTS 4162 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4163 return bpf_perf_link_fill_kprobe(event, info); 4164 #endif 4165 #ifdef CONFIG_UPROBE_EVENTS 4166 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4167 return bpf_perf_link_fill_uprobe(event, info); 4168 #endif 4169 return -EOPNOTSUPP; 4170 } 4171 4172 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 4173 struct bpf_link_info *info) 4174 { 4175 char __user *uname; 4176 u32 ulen; 4177 int err; 4178 4179 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 4180 ulen = info->perf_event.tracepoint.name_len; 4181 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 4182 if (err) 4183 return err; 4184 4185 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 4186 info->perf_event.tracepoint.name_len = ulen; 4187 info->perf_event.tracepoint.cookie = event->bpf_cookie; 4188 return 0; 4189 } 4190 4191 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 4192 struct bpf_link_info *info) 4193 { 4194 info->perf_event.event.type = event->attr.type; 4195 info->perf_event.event.config = event->attr.config; 4196 info->perf_event.event.cookie = event->bpf_cookie; 4197 info->perf_event.type = BPF_PERF_EVENT_EVENT; 4198 return 0; 4199 } 4200 4201 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 4202 struct bpf_link_info *info) 4203 { 4204 struct bpf_perf_link *perf_link; 4205 const struct perf_event *event; 4206 4207 perf_link = container_of(link, struct bpf_perf_link, link); 4208 event = perf_get_event(perf_link->perf_file); 4209 if (IS_ERR(event)) 4210 return PTR_ERR(event); 4211 4212 switch (event->prog->type) { 4213 case BPF_PROG_TYPE_PERF_EVENT: 4214 return bpf_perf_link_fill_perf_event(event, info); 4215 case BPF_PROG_TYPE_TRACEPOINT: 4216 return bpf_perf_link_fill_tracepoint(event, info); 4217 case BPF_PROG_TYPE_KPROBE: 4218 return bpf_perf_link_fill_probe(event, info); 4219 default: 4220 return -EOPNOTSUPP; 4221 } 4222 } 4223 4224 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, 4225 struct seq_file *seq) 4226 { 4227 seq_printf(seq, 4228 "type:\t%u\n" 4229 "config:\t%llu\n" 4230 "event_type:\t%s\n" 4231 "cookie:\t%llu\n", 4232 event->attr.type, event->attr.config, 4233 "event", event->bpf_cookie); 4234 } 4235 4236 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, 4237 struct seq_file *seq) 4238 { 4239 int err; 4240 const char *name; 4241 u32 prog_id; 4242 4243 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, 4244 NULL, NULL); 4245 if (err) 4246 return; 4247 4248 seq_printf(seq, 4249 "tp_name:\t%s\n" 4250 "event_type:\t%s\n" 4251 "cookie:\t%llu\n", 4252 name, "tracepoint", event->bpf_cookie); 4253 kfree_const(name); 4254 } 4255 4256 static void bpf_probe_link_show_fdinfo(const struct perf_event *event, 4257 struct seq_file *seq) 4258 { 4259 #ifdef CONFIG_KPROBE_EVENTS 4260 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4261 return bpf_perf_link_fdinfo_kprobe(event, seq); 4262 #endif 4263 4264 #ifdef CONFIG_UPROBE_EVENTS 4265 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4266 return bpf_perf_link_fdinfo_uprobe(event, seq); 4267 #endif 4268 } 4269 4270 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, 4271 struct seq_file *seq) 4272 { 4273 struct bpf_perf_link *perf_link; 4274 const struct perf_event *event; 4275 4276 perf_link = container_of(link, struct bpf_perf_link, link); 4277 event = perf_get_event(perf_link->perf_file); 4278 if (IS_ERR(event)) 4279 return; 4280 4281 switch (event->prog->type) { 4282 case BPF_PROG_TYPE_PERF_EVENT: 4283 return bpf_perf_event_link_show_fdinfo(event, seq); 4284 case BPF_PROG_TYPE_TRACEPOINT: 4285 return bpf_tracepoint_link_show_fdinfo(event, seq); 4286 case BPF_PROG_TYPE_KPROBE: 4287 return bpf_probe_link_show_fdinfo(event, seq); 4288 default: 4289 return; 4290 } 4291 } 4292 4293 static const struct bpf_link_ops bpf_perf_link_lops = { 4294 .release = bpf_perf_link_release, 4295 .dealloc = bpf_perf_link_dealloc, 4296 .fill_link_info = bpf_perf_link_fill_link_info, 4297 .show_fdinfo = bpf_perf_link_show_fdinfo, 4298 }; 4299 4300 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4301 { 4302 struct bpf_link_primer link_primer; 4303 struct bpf_perf_link *link; 4304 struct perf_event *event; 4305 struct file *perf_file; 4306 int err; 4307 4308 if (attr->link_create.flags) 4309 return -EINVAL; 4310 4311 perf_file = perf_event_get(attr->link_create.target_fd); 4312 if (IS_ERR(perf_file)) 4313 return PTR_ERR(perf_file); 4314 4315 link = kzalloc_obj(*link, GFP_USER); 4316 if (!link) { 4317 err = -ENOMEM; 4318 goto out_put_file; 4319 } 4320 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, 4321 attr->link_create.attach_type); 4322 link->perf_file = perf_file; 4323 4324 err = bpf_link_prime(&link->link, &link_primer); 4325 if (err) { 4326 kfree(link); 4327 goto out_put_file; 4328 } 4329 4330 event = perf_file->private_data; 4331 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 4332 if (err) { 4333 bpf_link_cleanup(&link_primer); 4334 goto out_put_file; 4335 } 4336 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 4337 bpf_prog_inc(prog); 4338 4339 return bpf_link_settle(&link_primer); 4340 4341 out_put_file: 4342 fput(perf_file); 4343 return err; 4344 } 4345 #else 4346 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4347 { 4348 return -EOPNOTSUPP; 4349 } 4350 #endif /* CONFIG_PERF_EVENTS */ 4351 4352 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 4353 const char __user *user_tp_name, u64 cookie, 4354 enum bpf_attach_type attach_type) 4355 { 4356 struct bpf_link_primer link_primer; 4357 struct bpf_raw_tp_link *link; 4358 struct bpf_raw_event_map *btp; 4359 const char *tp_name; 4360 char buf[128]; 4361 int err; 4362 4363 switch (prog->type) { 4364 case BPF_PROG_TYPE_TRACING: 4365 case BPF_PROG_TYPE_EXT: 4366 case BPF_PROG_TYPE_LSM: 4367 if (user_tp_name) 4368 /* The attach point for this category of programs 4369 * should be specified via btf_id during program load. 4370 */ 4371 return -EINVAL; 4372 if (prog->type == BPF_PROG_TYPE_TRACING && 4373 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 4374 tp_name = prog->aux->attach_func_name; 4375 break; 4376 } 4377 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); 4378 case BPF_PROG_TYPE_RAW_TRACEPOINT: 4379 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 4380 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 4381 return -EFAULT; 4382 buf[sizeof(buf) - 1] = 0; 4383 tp_name = buf; 4384 break; 4385 default: 4386 return -EINVAL; 4387 } 4388 4389 btp = bpf_get_raw_tracepoint(tp_name); 4390 if (!btp) 4391 return -ENOENT; 4392 4393 if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) { 4394 bpf_put_raw_tracepoint(btp); 4395 return -EINVAL; 4396 } 4397 4398 link = kzalloc_obj(*link, GFP_USER); 4399 if (!link) { 4400 err = -ENOMEM; 4401 goto out_put_btp; 4402 } 4403 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 4404 &bpf_raw_tp_link_lops, prog, attach_type, 4405 tracepoint_is_faultable(btp->tp)); 4406 link->btp = btp; 4407 link->cookie = cookie; 4408 4409 err = bpf_link_prime(&link->link, &link_primer); 4410 if (err) { 4411 kfree(link); 4412 goto out_put_btp; 4413 } 4414 4415 err = bpf_probe_register(link->btp, link); 4416 if (err) { 4417 bpf_link_cleanup(&link_primer); 4418 goto out_put_btp; 4419 } 4420 4421 return bpf_link_settle(&link_primer); 4422 4423 out_put_btp: 4424 bpf_put_raw_tracepoint(btp); 4425 return err; 4426 } 4427 4428 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 4429 4430 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4431 { 4432 struct bpf_prog *prog; 4433 void __user *tp_name; 4434 __u64 cookie; 4435 int fd; 4436 4437 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4438 return -EINVAL; 4439 4440 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4441 if (IS_ERR(prog)) 4442 return PTR_ERR(prog); 4443 4444 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4445 cookie = attr->raw_tracepoint.cookie; 4446 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); 4447 if (fd < 0) 4448 bpf_prog_put(prog); 4449 return fd; 4450 } 4451 4452 static enum bpf_prog_type 4453 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4454 { 4455 switch (attach_type) { 4456 case BPF_CGROUP_INET_INGRESS: 4457 case BPF_CGROUP_INET_EGRESS: 4458 return BPF_PROG_TYPE_CGROUP_SKB; 4459 case BPF_CGROUP_INET_SOCK_CREATE: 4460 case BPF_CGROUP_INET_SOCK_RELEASE: 4461 case BPF_CGROUP_INET4_POST_BIND: 4462 case BPF_CGROUP_INET6_POST_BIND: 4463 return BPF_PROG_TYPE_CGROUP_SOCK; 4464 case BPF_CGROUP_INET4_BIND: 4465 case BPF_CGROUP_INET6_BIND: 4466 case BPF_CGROUP_INET4_CONNECT: 4467 case BPF_CGROUP_INET6_CONNECT: 4468 case BPF_CGROUP_UNIX_CONNECT: 4469 case BPF_CGROUP_INET4_GETPEERNAME: 4470 case BPF_CGROUP_INET6_GETPEERNAME: 4471 case BPF_CGROUP_UNIX_GETPEERNAME: 4472 case BPF_CGROUP_INET4_GETSOCKNAME: 4473 case BPF_CGROUP_INET6_GETSOCKNAME: 4474 case BPF_CGROUP_UNIX_GETSOCKNAME: 4475 case BPF_CGROUP_UDP4_SENDMSG: 4476 case BPF_CGROUP_UDP6_SENDMSG: 4477 case BPF_CGROUP_UNIX_SENDMSG: 4478 case BPF_CGROUP_UDP4_RECVMSG: 4479 case BPF_CGROUP_UDP6_RECVMSG: 4480 case BPF_CGROUP_UNIX_RECVMSG: 4481 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4482 case BPF_CGROUP_SOCK_OPS: 4483 return BPF_PROG_TYPE_SOCK_OPS; 4484 case BPF_CGROUP_DEVICE: 4485 return BPF_PROG_TYPE_CGROUP_DEVICE; 4486 case BPF_SK_MSG_VERDICT: 4487 return BPF_PROG_TYPE_SK_MSG; 4488 case BPF_SK_SKB_STREAM_PARSER: 4489 case BPF_SK_SKB_STREAM_VERDICT: 4490 case BPF_SK_SKB_VERDICT: 4491 return BPF_PROG_TYPE_SK_SKB; 4492 case BPF_LIRC_MODE2: 4493 return BPF_PROG_TYPE_LIRC_MODE2; 4494 case BPF_FLOW_DISSECTOR: 4495 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4496 case BPF_CGROUP_SYSCTL: 4497 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4498 case BPF_CGROUP_GETSOCKOPT: 4499 case BPF_CGROUP_SETSOCKOPT: 4500 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4501 case BPF_TRACE_ITER: 4502 case BPF_TRACE_RAW_TP: 4503 case BPF_TRACE_FENTRY: 4504 case BPF_TRACE_FEXIT: 4505 case BPF_TRACE_FSESSION: 4506 case BPF_TRACE_FSESSION_MULTI: 4507 case BPF_TRACE_FENTRY_MULTI: 4508 case BPF_TRACE_FEXIT_MULTI: 4509 case BPF_MODIFY_RETURN: 4510 return BPF_PROG_TYPE_TRACING; 4511 case BPF_LSM_MAC: 4512 return BPF_PROG_TYPE_LSM; 4513 case BPF_SK_LOOKUP: 4514 return BPF_PROG_TYPE_SK_LOOKUP; 4515 case BPF_XDP: 4516 return BPF_PROG_TYPE_XDP; 4517 case BPF_LSM_CGROUP: 4518 return BPF_PROG_TYPE_LSM; 4519 case BPF_TCX_INGRESS: 4520 case BPF_TCX_EGRESS: 4521 case BPF_NETKIT_PRIMARY: 4522 case BPF_NETKIT_PEER: 4523 return BPF_PROG_TYPE_SCHED_CLS; 4524 default: 4525 return BPF_PROG_TYPE_UNSPEC; 4526 } 4527 } 4528 4529 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4530 enum bpf_attach_type attach_type) 4531 { 4532 enum bpf_prog_type ptype; 4533 4534 switch (prog->type) { 4535 case BPF_PROG_TYPE_CGROUP_SOCK: 4536 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4537 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4538 case BPF_PROG_TYPE_SK_LOOKUP: 4539 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4540 case BPF_PROG_TYPE_CGROUP_SKB: 4541 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4542 /* cg-skb progs can be loaded by unpriv user. 4543 * check permissions at attach time. 4544 */ 4545 return -EPERM; 4546 4547 ptype = attach_type_to_prog_type(attach_type); 4548 if (prog->type != ptype) 4549 return -EINVAL; 4550 4551 return prog->enforce_expected_attach_type && 4552 prog->expected_attach_type != attach_type ? 4553 -EINVAL : 0; 4554 case BPF_PROG_TYPE_EXT: 4555 return 0; 4556 case BPF_PROG_TYPE_NETFILTER: 4557 if (attach_type != BPF_NETFILTER) 4558 return -EINVAL; 4559 return 0; 4560 case BPF_PROG_TYPE_PERF_EVENT: 4561 case BPF_PROG_TYPE_TRACEPOINT: 4562 if (attach_type != BPF_PERF_EVENT) 4563 return -EINVAL; 4564 return 0; 4565 case BPF_PROG_TYPE_KPROBE: 4566 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4567 attach_type != BPF_TRACE_KPROBE_MULTI) 4568 return -EINVAL; 4569 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4570 attach_type != BPF_TRACE_KPROBE_SESSION) 4571 return -EINVAL; 4572 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4573 attach_type != BPF_TRACE_UPROBE_MULTI) 4574 return -EINVAL; 4575 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4576 attach_type != BPF_TRACE_UPROBE_SESSION) 4577 return -EINVAL; 4578 if (attach_type != BPF_PERF_EVENT && 4579 attach_type != BPF_TRACE_KPROBE_MULTI && 4580 attach_type != BPF_TRACE_KPROBE_SESSION && 4581 attach_type != BPF_TRACE_UPROBE_MULTI && 4582 attach_type != BPF_TRACE_UPROBE_SESSION) 4583 return -EINVAL; 4584 return 0; 4585 case BPF_PROG_TYPE_SCHED_CLS: 4586 if (attach_type != BPF_TCX_INGRESS && 4587 attach_type != BPF_TCX_EGRESS && 4588 attach_type != BPF_NETKIT_PRIMARY && 4589 attach_type != BPF_NETKIT_PEER) 4590 return -EINVAL; 4591 return 0; 4592 default: 4593 ptype = attach_type_to_prog_type(attach_type); 4594 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4595 return -EINVAL; 4596 return 0; 4597 } 4598 } 4599 4600 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, 4601 bool check_atype) 4602 { 4603 switch (ptype) { 4604 case BPF_PROG_TYPE_CGROUP_DEVICE: 4605 case BPF_PROG_TYPE_CGROUP_SKB: 4606 case BPF_PROG_TYPE_CGROUP_SOCK: 4607 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4608 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4609 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4610 case BPF_PROG_TYPE_SOCK_OPS: 4611 return true; 4612 case BPF_PROG_TYPE_LSM: 4613 return check_atype ? atype == BPF_LSM_CGROUP : true; 4614 default: 4615 return false; 4616 } 4617 } 4618 4619 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4620 4621 #define BPF_F_ATTACH_MASK_BASE \ 4622 (BPF_F_ALLOW_OVERRIDE | \ 4623 BPF_F_ALLOW_MULTI | \ 4624 BPF_F_REPLACE | \ 4625 BPF_F_PREORDER) 4626 4627 #define BPF_F_ATTACH_MASK_MPROG \ 4628 (BPF_F_REPLACE | \ 4629 BPF_F_BEFORE | \ 4630 BPF_F_AFTER | \ 4631 BPF_F_ID | \ 4632 BPF_F_LINK) 4633 4634 static int bpf_prog_attach(const union bpf_attr *attr) 4635 { 4636 enum bpf_prog_type ptype; 4637 struct bpf_prog *prog; 4638 int ret; 4639 4640 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4641 return -EINVAL; 4642 4643 ptype = attach_type_to_prog_type(attr->attach_type); 4644 if (ptype == BPF_PROG_TYPE_UNSPEC) 4645 return -EINVAL; 4646 if (bpf_mprog_supported(ptype)) { 4647 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4648 return -EINVAL; 4649 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4650 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) 4651 return -EINVAL; 4652 } else { 4653 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4654 return -EINVAL; 4655 if (attr->relative_fd || 4656 attr->expected_revision) 4657 return -EINVAL; 4658 } 4659 4660 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4661 if (IS_ERR(prog)) 4662 return PTR_ERR(prog); 4663 4664 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4665 bpf_prog_put(prog); 4666 return -EINVAL; 4667 } 4668 4669 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { 4670 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4671 goto out; 4672 } 4673 4674 switch (ptype) { 4675 case BPF_PROG_TYPE_SK_SKB: 4676 case BPF_PROG_TYPE_SK_MSG: 4677 ret = sock_map_get_from_fd(attr, prog); 4678 break; 4679 case BPF_PROG_TYPE_LIRC_MODE2: 4680 ret = lirc_prog_attach(attr, prog); 4681 break; 4682 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4683 ret = netns_bpf_prog_attach(attr, prog); 4684 break; 4685 case BPF_PROG_TYPE_SCHED_CLS: 4686 if (attr->attach_type == BPF_TCX_INGRESS || 4687 attr->attach_type == BPF_TCX_EGRESS) 4688 ret = tcx_prog_attach(attr, prog); 4689 else 4690 ret = netkit_prog_attach(attr, prog); 4691 break; 4692 default: 4693 ret = -EINVAL; 4694 } 4695 out: 4696 if (ret) 4697 bpf_prog_put(prog); 4698 return ret; 4699 } 4700 4701 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4702 4703 static int bpf_prog_detach(const union bpf_attr *attr) 4704 { 4705 struct bpf_prog *prog = NULL; 4706 enum bpf_prog_type ptype; 4707 int ret; 4708 4709 if (CHECK_ATTR(BPF_PROG_DETACH)) 4710 return -EINVAL; 4711 4712 ptype = attach_type_to_prog_type(attr->attach_type); 4713 if (bpf_mprog_supported(ptype)) { 4714 if (ptype == BPF_PROG_TYPE_UNSPEC) 4715 return -EINVAL; 4716 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4717 return -EINVAL; 4718 if (attr->attach_bpf_fd) { 4719 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4720 if (IS_ERR(prog)) 4721 return PTR_ERR(prog); 4722 } else if (!bpf_mprog_detach_empty(ptype)) { 4723 return -EPERM; 4724 } 4725 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4726 if (attr->attach_flags || attr->relative_fd) 4727 return -EINVAL; 4728 } else if (attr->attach_flags || 4729 attr->relative_fd || 4730 attr->expected_revision) { 4731 return -EINVAL; 4732 } 4733 4734 switch (ptype) { 4735 case BPF_PROG_TYPE_SK_MSG: 4736 case BPF_PROG_TYPE_SK_SKB: 4737 ret = sock_map_prog_detach(attr, ptype); 4738 break; 4739 case BPF_PROG_TYPE_LIRC_MODE2: 4740 ret = lirc_prog_detach(attr); 4741 break; 4742 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4743 ret = netns_bpf_prog_detach(attr, ptype); 4744 break; 4745 case BPF_PROG_TYPE_CGROUP_DEVICE: 4746 case BPF_PROG_TYPE_CGROUP_SKB: 4747 case BPF_PROG_TYPE_CGROUP_SOCK: 4748 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4749 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4750 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4751 case BPF_PROG_TYPE_SOCK_OPS: 4752 case BPF_PROG_TYPE_LSM: 4753 ret = cgroup_bpf_prog_detach(attr, ptype); 4754 break; 4755 case BPF_PROG_TYPE_SCHED_CLS: 4756 if (attr->attach_type == BPF_TCX_INGRESS || 4757 attr->attach_type == BPF_TCX_EGRESS) 4758 ret = tcx_prog_detach(attr, prog); 4759 else 4760 ret = netkit_prog_detach(attr, prog); 4761 break; 4762 default: 4763 ret = -EINVAL; 4764 } 4765 4766 if (prog) 4767 bpf_prog_put(prog); 4768 return ret; 4769 } 4770 4771 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4772 4773 static int bpf_prog_query(const union bpf_attr *attr, 4774 union bpf_attr __user *uattr, u32 uattr_size) 4775 { 4776 if (!bpf_net_capable()) 4777 return -EPERM; 4778 if (CHECK_ATTR(BPF_PROG_QUERY)) 4779 return -EINVAL; 4780 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4781 return -EINVAL; 4782 4783 switch (attr->query.attach_type) { 4784 case BPF_CGROUP_INET_INGRESS: 4785 case BPF_CGROUP_INET_EGRESS: 4786 case BPF_CGROUP_INET_SOCK_CREATE: 4787 case BPF_CGROUP_INET_SOCK_RELEASE: 4788 case BPF_CGROUP_INET4_BIND: 4789 case BPF_CGROUP_INET6_BIND: 4790 case BPF_CGROUP_INET4_POST_BIND: 4791 case BPF_CGROUP_INET6_POST_BIND: 4792 case BPF_CGROUP_INET4_CONNECT: 4793 case BPF_CGROUP_INET6_CONNECT: 4794 case BPF_CGROUP_UNIX_CONNECT: 4795 case BPF_CGROUP_INET4_GETPEERNAME: 4796 case BPF_CGROUP_INET6_GETPEERNAME: 4797 case BPF_CGROUP_UNIX_GETPEERNAME: 4798 case BPF_CGROUP_INET4_GETSOCKNAME: 4799 case BPF_CGROUP_INET6_GETSOCKNAME: 4800 case BPF_CGROUP_UNIX_GETSOCKNAME: 4801 case BPF_CGROUP_UDP4_SENDMSG: 4802 case BPF_CGROUP_UDP6_SENDMSG: 4803 case BPF_CGROUP_UNIX_SENDMSG: 4804 case BPF_CGROUP_UDP4_RECVMSG: 4805 case BPF_CGROUP_UDP6_RECVMSG: 4806 case BPF_CGROUP_UNIX_RECVMSG: 4807 case BPF_CGROUP_SOCK_OPS: 4808 case BPF_CGROUP_DEVICE: 4809 case BPF_CGROUP_SYSCTL: 4810 case BPF_CGROUP_GETSOCKOPT: 4811 case BPF_CGROUP_SETSOCKOPT: 4812 case BPF_LSM_CGROUP: 4813 case BPF_STRUCT_OPS: 4814 return cgroup_bpf_prog_query(attr, uattr, uattr_size); 4815 case BPF_LIRC_MODE2: 4816 return lirc_prog_query(attr, uattr); 4817 case BPF_FLOW_DISSECTOR: 4818 case BPF_SK_LOOKUP: 4819 return netns_bpf_prog_query(attr, uattr); 4820 case BPF_SK_SKB_STREAM_PARSER: 4821 case BPF_SK_SKB_STREAM_VERDICT: 4822 case BPF_SK_MSG_VERDICT: 4823 case BPF_SK_SKB_VERDICT: 4824 return sock_map_bpf_prog_query(attr, uattr); 4825 case BPF_TCX_INGRESS: 4826 case BPF_TCX_EGRESS: 4827 return tcx_prog_query(attr, uattr); 4828 case BPF_NETKIT_PRIMARY: 4829 case BPF_NETKIT_PEER: 4830 return netkit_prog_query(attr, uattr); 4831 default: 4832 return -EINVAL; 4833 } 4834 } 4835 4836 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4837 4838 static int bpf_prog_test_run(const union bpf_attr *attr, 4839 union bpf_attr __user *uattr) 4840 { 4841 struct bpf_prog *prog; 4842 int ret = -ENOTSUPP; 4843 4844 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4845 return -EINVAL; 4846 4847 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4848 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4849 return -EINVAL; 4850 4851 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4852 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4853 return -EINVAL; 4854 4855 prog = bpf_prog_get(attr->test.prog_fd); 4856 if (IS_ERR(prog)) 4857 return PTR_ERR(prog); 4858 4859 if (prog->aux->ops->test_run) 4860 ret = prog->aux->ops->test_run(prog, attr, uattr); 4861 4862 bpf_prog_put(prog); 4863 return ret; 4864 } 4865 4866 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4867 4868 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4869 union bpf_attr __user *uattr, 4870 struct idr *idr, 4871 spinlock_t *lock) 4872 { 4873 u32 next_id = attr->start_id; 4874 int err = 0; 4875 4876 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4877 return -EINVAL; 4878 4879 if (!capable(CAP_SYS_ADMIN)) 4880 return -EPERM; 4881 4882 next_id++; 4883 spin_lock_bh(lock); 4884 if (!idr_get_next(idr, &next_id)) 4885 err = -ENOENT; 4886 spin_unlock_bh(lock); 4887 4888 if (!err) 4889 err = put_user(next_id, &uattr->next_id); 4890 4891 return err; 4892 } 4893 4894 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4895 { 4896 struct bpf_map *map; 4897 4898 spin_lock_bh(&map_idr_lock); 4899 again: 4900 map = idr_get_next(&map_idr, id); 4901 if (map) { 4902 map = __bpf_map_inc_not_zero(map, false); 4903 if (IS_ERR(map)) { 4904 (*id)++; 4905 goto again; 4906 } 4907 } 4908 spin_unlock_bh(&map_idr_lock); 4909 4910 return map; 4911 } 4912 4913 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4914 { 4915 struct bpf_prog *prog; 4916 4917 spin_lock_bh(&prog_idr_lock); 4918 again: 4919 prog = idr_get_next(&prog_idr, id); 4920 if (prog) { 4921 prog = bpf_prog_inc_not_zero(prog); 4922 if (IS_ERR(prog)) { 4923 (*id)++; 4924 goto again; 4925 } 4926 } 4927 spin_unlock_bh(&prog_idr_lock); 4928 4929 return prog; 4930 } 4931 4932 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4933 4934 struct bpf_prog *bpf_prog_by_id(u32 id) 4935 { 4936 struct bpf_prog *prog; 4937 4938 if (!id) 4939 return ERR_PTR(-ENOENT); 4940 4941 spin_lock_bh(&prog_idr_lock); 4942 prog = idr_find(&prog_idr, id); 4943 if (prog) 4944 prog = bpf_prog_inc_not_zero(prog); 4945 else 4946 prog = ERR_PTR(-ENOENT); 4947 spin_unlock_bh(&prog_idr_lock); 4948 return prog; 4949 } 4950 4951 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4952 { 4953 struct bpf_prog *prog; 4954 u32 id = attr->prog_id; 4955 int fd; 4956 4957 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4958 return -EINVAL; 4959 4960 if (!capable(CAP_SYS_ADMIN)) 4961 return -EPERM; 4962 4963 prog = bpf_prog_by_id(id); 4964 if (IS_ERR(prog)) 4965 return PTR_ERR(prog); 4966 4967 fd = bpf_prog_new_fd(prog); 4968 if (fd < 0) 4969 bpf_prog_put(prog); 4970 4971 return fd; 4972 } 4973 4974 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4975 4976 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4977 { 4978 struct bpf_map *map; 4979 u32 id = attr->map_id; 4980 int f_flags; 4981 int fd; 4982 4983 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4984 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4985 return -EINVAL; 4986 4987 if (!capable(CAP_SYS_ADMIN)) 4988 return -EPERM; 4989 4990 f_flags = bpf_get_file_flag(attr->open_flags); 4991 if (f_flags < 0) 4992 return f_flags; 4993 4994 spin_lock_bh(&map_idr_lock); 4995 map = idr_find(&map_idr, id); 4996 if (map) 4997 map = __bpf_map_inc_not_zero(map, true); 4998 else 4999 map = ERR_PTR(-ENOENT); 5000 spin_unlock_bh(&map_idr_lock); 5001 5002 if (IS_ERR(map)) 5003 return PTR_ERR(map); 5004 5005 fd = bpf_map_new_fd(map, f_flags); 5006 if (fd < 0) 5007 bpf_map_put_with_uref(map); 5008 5009 return fd; 5010 } 5011 5012 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 5013 unsigned long addr, u32 *off, 5014 u32 *type) 5015 { 5016 const struct bpf_map *map; 5017 int i; 5018 5019 mutex_lock(&prog->aux->used_maps_mutex); 5020 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 5021 map = prog->aux->used_maps[i]; 5022 if (map == (void *)addr) { 5023 *type = BPF_PSEUDO_MAP_FD; 5024 goto out; 5025 } 5026 if (!map->ops->map_direct_value_meta) 5027 continue; 5028 if (!map->ops->map_direct_value_meta(map, addr, off)) { 5029 *type = BPF_PSEUDO_MAP_VALUE; 5030 goto out; 5031 } 5032 } 5033 map = NULL; 5034 5035 out: 5036 mutex_unlock(&prog->aux->used_maps_mutex); 5037 return map; 5038 } 5039 5040 static void prepare_dump_pseudo_call(struct bpf_insn *insn) 5041 { 5042 s32 call_off = insn->imm; 5043 5044 /* 5045 * BPF_CALL_ARGS only exists for interpreter fallback. 5046 * 1. For interpreter (BPF_CALL_ARGS): insn->off is the index of 5047 * interpreters_args array, so here using bpf_call_args_imm() 5048 * to get the real address offset. 5049 * 2. For JIT (BPF_CALL): insn->off is the subprog id. 5050 */ 5051 if (insn->code == (BPF_JMP | BPF_CALL_ARGS)) 5052 insn->imm = bpf_call_args_imm(insn->off); 5053 else 5054 insn->imm = insn->off; 5055 5056 /* Avoid dumping a truncated and misleading pc-relative offset. */ 5057 if (call_off > S16_MAX || call_off < S16_MIN) 5058 insn->off = 0; 5059 else 5060 insn->off = call_off; 5061 } 5062 5063 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 5064 const struct cred *f_cred) 5065 { 5066 const struct bpf_map *map; 5067 struct bpf_insn *insns; 5068 u32 off, type; 5069 u64 imm; 5070 u8 code; 5071 int i; 5072 5073 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 5074 GFP_USER); 5075 if (!insns) 5076 return insns; 5077 5078 for (i = 0; i < prog->len; i++) { 5079 code = insns[i].code; 5080 5081 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 5082 insns[i].code = BPF_JMP | BPF_CALL; 5083 insns[i].imm = BPF_FUNC_tail_call; 5084 /* fall-through */ 5085 } 5086 /* 5087 * BPF_JCOND is the same opcode as BPF_CALL_ARGS. The latter is for 5088 * the interpreter, and a prog with unwind_goto is always JITed. 5089 */ 5090 if (prog->jited && bpf_is_unwind_goto(&insns[i])) 5091 continue; 5092 if (code == (BPF_JMP | BPF_CALL) || 5093 code == (BPF_JMP | BPF_CALL_ARGS)) { 5094 /* Restore the legacy xlated dump layout. */ 5095 if (insns[i].src_reg == BPF_PSEUDO_CALL) 5096 prepare_dump_pseudo_call(&insns[i]); 5097 if (code == (BPF_JMP | BPF_CALL_ARGS)) 5098 insns[i].code = BPF_JMP | BPF_CALL; 5099 if (!bpf_dump_raw_ok(f_cred)) 5100 insns[i].imm = 0; 5101 continue; 5102 } 5103 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 5104 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 5105 continue; 5106 } 5107 5108 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 5109 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 5110 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 5111 continue; 5112 } 5113 5114 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 5115 continue; 5116 5117 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 5118 map = bpf_map_from_imm(prog, imm, &off, &type); 5119 if (map) { 5120 insns[i].src_reg = type; 5121 insns[i].imm = map->id; 5122 insns[i + 1].imm = off; 5123 continue; 5124 } 5125 } 5126 5127 return insns; 5128 } 5129 5130 static int set_info_rec_size(struct bpf_prog_info *info) 5131 { 5132 /* 5133 * Ensure info.*_rec_size is the same as kernel expected size 5134 * 5135 * or 5136 * 5137 * Only allow zero *_rec_size if both _rec_size and _cnt are 5138 * zero. In this case, the kernel will set the expected 5139 * _rec_size back to the info. 5140 */ 5141 5142 if ((info->nr_func_info || info->func_info_rec_size) && 5143 info->func_info_rec_size != sizeof(struct bpf_func_info)) 5144 return -EINVAL; 5145 5146 if ((info->nr_line_info || info->line_info_rec_size) && 5147 info->line_info_rec_size != sizeof(struct bpf_line_info)) 5148 return -EINVAL; 5149 5150 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 5151 info->jited_line_info_rec_size != sizeof(__u64)) 5152 return -EINVAL; 5153 5154 info->func_info_rec_size = sizeof(struct bpf_func_info); 5155 info->line_info_rec_size = sizeof(struct bpf_line_info); 5156 info->jited_line_info_rec_size = sizeof(__u64); 5157 5158 return 0; 5159 } 5160 5161 static int bpf_prog_get_info_by_fd(struct file *file, 5162 struct bpf_prog *prog, 5163 const union bpf_attr *attr, 5164 union bpf_attr __user *uattr) 5165 { 5166 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5167 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 5168 struct bpf_prog_info info; 5169 u32 info_len = attr->info.info_len; 5170 struct bpf_prog_kstats stats; 5171 char __user *uinsns; 5172 u32 ulen, len; 5173 int err; 5174 5175 len = offsetofend(struct bpf_prog_info, attach_btf_id); 5176 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len); 5177 if (err) 5178 return err; 5179 info_len = min_t(u32, sizeof(info), info_len); 5180 5181 memset(&info, 0, sizeof(info)); 5182 if (copy_from_user(&info, uinfo, info_len)) 5183 return -EFAULT; 5184 5185 info.type = prog->type; 5186 info.id = prog->aux->id; 5187 info.load_time = prog->aux->load_time; 5188 info.created_by_uid = from_kuid_munged(current_user_ns(), 5189 prog->aux->user->uid); 5190 info.gpl_compatible = prog->gpl_compatible; 5191 5192 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 5193 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 5194 5195 mutex_lock(&prog->aux->used_maps_mutex); 5196 ulen = info.nr_map_ids; 5197 info.nr_map_ids = prog->aux->used_map_cnt; 5198 ulen = min_t(u32, info.nr_map_ids, ulen); 5199 if (ulen) { 5200 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 5201 u32 i; 5202 5203 for (i = 0; i < ulen; i++) 5204 if (put_user(prog->aux->used_maps[i]->id, 5205 &user_map_ids[i])) { 5206 mutex_unlock(&prog->aux->used_maps_mutex); 5207 return -EFAULT; 5208 } 5209 } 5210 mutex_unlock(&prog->aux->used_maps_mutex); 5211 5212 err = set_info_rec_size(&info); 5213 if (err) 5214 return err; 5215 5216 bpf_prog_get_stats(prog, &stats); 5217 info.run_time_ns = stats.nsecs; 5218 info.run_cnt = stats.cnt; 5219 info.recursion_misses = stats.misses; 5220 5221 info.verified_insns = prog->aux->verified_insns; 5222 if (prog->aux->btf) 5223 info.btf_id = btf_obj_id(prog->aux->btf); 5224 5225 if (!bpf_capable()) { 5226 info.jited_prog_len = 0; 5227 info.xlated_prog_len = 0; 5228 info.nr_jited_ksyms = 0; 5229 info.nr_jited_func_lens = 0; 5230 info.nr_func_info = 0; 5231 info.nr_line_info = 0; 5232 info.nr_jited_line_info = 0; 5233 goto done; 5234 } 5235 5236 ulen = info.xlated_prog_len; 5237 info.xlated_prog_len = bpf_prog_insn_size(prog); 5238 if (info.xlated_prog_len && ulen) { 5239 struct bpf_insn *insns_sanitized; 5240 bool fault; 5241 5242 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) { 5243 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 5244 if (!insns_sanitized) 5245 return -ENOMEM; 5246 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 5247 ulen = min_t(u32, info.xlated_prog_len, ulen); 5248 fault = copy_to_user(uinsns, insns_sanitized, ulen); 5249 kfree(insns_sanitized); 5250 if (fault) 5251 return -EFAULT; 5252 } else { 5253 info.xlated_prog_insns = 0; 5254 } 5255 } 5256 5257 if (bpf_prog_is_offloaded(prog->aux)) { 5258 err = bpf_prog_offload_info_fill(&info, prog); 5259 if (err) 5260 return err; 5261 goto done; 5262 } 5263 5264 /* NOTE: the following code is supposed to be skipped for offload. 5265 * bpf_prog_offload_info_fill() is the place to fill similar fields 5266 * for offload. 5267 */ 5268 ulen = info.jited_prog_len; 5269 if (prog->aux->func_cnt) { 5270 u32 i; 5271 5272 info.jited_prog_len = 0; 5273 for (i = 0; i < prog->aux->func_cnt; i++) 5274 info.jited_prog_len += prog->aux->func[i]->jited_len; 5275 } else { 5276 info.jited_prog_len = prog->jited_len; 5277 } 5278 5279 if (info.jited_prog_len && ulen) { 5280 if (bpf_dump_raw_ok(file->f_cred)) { 5281 uinsns = u64_to_user_ptr(info.jited_prog_insns); 5282 ulen = min_t(u32, info.jited_prog_len, ulen); 5283 5284 /* for multi-function programs, copy the JITed 5285 * instructions for all the functions 5286 */ 5287 if (prog->aux->func_cnt) { 5288 u32 len, free, i; 5289 u8 *img; 5290 5291 free = ulen; 5292 for (i = 0; i < prog->aux->func_cnt; i++) { 5293 len = prog->aux->func[i]->jited_len; 5294 len = min_t(u32, len, free); 5295 img = (u8 *) prog->aux->func[i]->bpf_func; 5296 if (copy_to_user(uinsns, img, len)) 5297 return -EFAULT; 5298 uinsns += len; 5299 free -= len; 5300 if (!free) 5301 break; 5302 } 5303 } else { 5304 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 5305 return -EFAULT; 5306 } 5307 } else { 5308 info.jited_prog_insns = 0; 5309 } 5310 } 5311 5312 ulen = info.nr_jited_ksyms; 5313 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 5314 if (ulen) { 5315 if (bpf_dump_raw_ok(file->f_cred)) { 5316 unsigned long ksym_addr; 5317 u64 __user *user_ksyms; 5318 u32 i; 5319 5320 /* copy the address of the kernel symbol 5321 * corresponding to each function 5322 */ 5323 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 5324 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 5325 if (prog->aux->func_cnt) { 5326 for (i = 0; i < ulen; i++) { 5327 ksym_addr = (unsigned long) 5328 prog->aux->func[i]->bpf_func; 5329 if (put_user((u64) ksym_addr, 5330 &user_ksyms[i])) 5331 return -EFAULT; 5332 } 5333 } else { 5334 ksym_addr = (unsigned long) prog->bpf_func; 5335 if (put_user((u64) ksym_addr, &user_ksyms[0])) 5336 return -EFAULT; 5337 } 5338 } else { 5339 info.jited_ksyms = 0; 5340 } 5341 } 5342 5343 ulen = info.nr_jited_func_lens; 5344 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 5345 if (ulen) { 5346 if (bpf_dump_raw_ok(file->f_cred)) { 5347 u32 __user *user_lens; 5348 u32 func_len, i; 5349 5350 /* copy the JITed image lengths for each function */ 5351 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 5352 user_lens = u64_to_user_ptr(info.jited_func_lens); 5353 if (prog->aux->func_cnt) { 5354 for (i = 0; i < ulen; i++) { 5355 func_len = 5356 prog->aux->func[i]->jited_len; 5357 if (put_user(func_len, &user_lens[i])) 5358 return -EFAULT; 5359 } 5360 } else { 5361 func_len = prog->jited_len; 5362 if (put_user(func_len, &user_lens[0])) 5363 return -EFAULT; 5364 } 5365 } else { 5366 info.jited_func_lens = 0; 5367 } 5368 } 5369 5370 info.attach_btf_id = prog->aux->attach_btf_id; 5371 if (attach_btf) 5372 info.attach_btf_obj_id = btf_obj_id(attach_btf); 5373 5374 ulen = info.nr_func_info; 5375 info.nr_func_info = prog->aux->func_info_cnt; 5376 if (info.nr_func_info && ulen) { 5377 char __user *user_finfo; 5378 5379 user_finfo = u64_to_user_ptr(info.func_info); 5380 ulen = min_t(u32, info.nr_func_info, ulen); 5381 if (copy_to_user(user_finfo, prog->aux->func_info, 5382 info.func_info_rec_size * ulen)) 5383 return -EFAULT; 5384 } 5385 5386 ulen = info.nr_line_info; 5387 info.nr_line_info = prog->aux->nr_linfo; 5388 if (info.nr_line_info && ulen) { 5389 __u8 __user *user_linfo; 5390 5391 user_linfo = u64_to_user_ptr(info.line_info); 5392 ulen = min_t(u32, info.nr_line_info, ulen); 5393 if (copy_to_user(user_linfo, prog->aux->linfo, 5394 info.line_info_rec_size * ulen)) 5395 return -EFAULT; 5396 } 5397 5398 ulen = info.nr_jited_line_info; 5399 if (prog->aux->jited_linfo) 5400 info.nr_jited_line_info = prog->aux->nr_linfo; 5401 else 5402 info.nr_jited_line_info = 0; 5403 if (info.nr_jited_line_info && ulen) { 5404 if (bpf_dump_raw_ok(file->f_cred)) { 5405 unsigned long line_addr; 5406 __u64 __user *user_linfo; 5407 u32 i; 5408 5409 user_linfo = u64_to_user_ptr(info.jited_line_info); 5410 ulen = min_t(u32, info.nr_jited_line_info, ulen); 5411 for (i = 0; i < ulen; i++) { 5412 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 5413 if (put_user((__u64)line_addr, &user_linfo[i])) 5414 return -EFAULT; 5415 } 5416 } else { 5417 info.jited_line_info = 0; 5418 } 5419 } 5420 5421 ulen = info.nr_prog_tags; 5422 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 5423 if (ulen) { 5424 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 5425 u32 i; 5426 5427 user_prog_tags = u64_to_user_ptr(info.prog_tags); 5428 ulen = min_t(u32, info.nr_prog_tags, ulen); 5429 if (prog->aux->func_cnt) { 5430 for (i = 0; i < ulen; i++) { 5431 if (copy_to_user(user_prog_tags[i], 5432 prog->aux->func[i]->tag, 5433 BPF_TAG_SIZE)) 5434 return -EFAULT; 5435 } 5436 } else { 5437 if (copy_to_user(user_prog_tags[0], 5438 prog->tag, BPF_TAG_SIZE)) 5439 return -EFAULT; 5440 } 5441 } 5442 5443 done: 5444 if (copy_to_user(uinfo, &info, info_len) || 5445 put_user(info_len, &uattr->info.info_len)) 5446 return -EFAULT; 5447 5448 return 0; 5449 } 5450 5451 static int bpf_map_get_info_by_fd(struct file *file, 5452 struct bpf_map *map, 5453 const union bpf_attr *attr, 5454 union bpf_attr __user *uattr) 5455 { 5456 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5457 struct bpf_map_info info; 5458 u32 info_len = attr->info.info_len, len; 5459 int err; 5460 5461 len = offsetofend(struct bpf_map_info, hash_size); 5462 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len); 5463 if (err) 5464 return err; 5465 info_len = min_t(u32, sizeof(info), info_len); 5466 5467 memset(&info, 0, sizeof(info)); 5468 if (info_len >= offsetofend(struct bpf_map_info, hash) && 5469 get_user(info.hash, &uinfo->hash)) 5470 return -EFAULT; 5471 if (info_len >= offsetofend(struct bpf_map_info, hash_size) && 5472 get_user(info.hash_size, &uinfo->hash_size)) 5473 return -EFAULT; 5474 5475 info.type = map->map_type; 5476 info.id = map->id; 5477 info.key_size = map->key_size; 5478 info.value_size = map->value_size; 5479 info.max_entries = map->max_entries; 5480 info.map_flags = map->map_flags; 5481 info.map_extra = map->map_extra; 5482 memcpy(info.name, map->name, sizeof(map->name)); 5483 5484 if (map->btf) { 5485 info.btf_id = btf_obj_id(map->btf); 5486 info.btf_key_type_id = map->btf_key_type_id; 5487 info.btf_value_type_id = map->btf_value_type_id; 5488 } 5489 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 5490 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 5491 bpf_map_struct_ops_info_fill(&info, map); 5492 5493 if (bpf_map_is_offloaded(map)) { 5494 err = bpf_map_offload_info_fill(&info, map); 5495 if (err) 5496 return err; 5497 } 5498 5499 if (info.hash) { 5500 char __user *uhash = u64_to_user_ptr(info.hash); 5501 5502 if (!map->ops->map_get_hash) 5503 return -EINVAL; 5504 if (info.hash_size != sizeof(map->sha)) 5505 return -EINVAL; 5506 if (!READ_ONCE(map->frozen)) 5507 return -EPERM; 5508 5509 err = map->ops->map_get_hash(map); 5510 if (err != 0) 5511 return err; 5512 5513 if (copy_to_user(uhash, map->sha, sizeof(map->sha)) != 0) 5514 return -EFAULT; 5515 } else if (info.hash_size) { 5516 return -EINVAL; 5517 } 5518 5519 if (copy_to_user(uinfo, &info, info_len) || 5520 put_user(info_len, &uattr->info.info_len)) 5521 return -EFAULT; 5522 5523 return 0; 5524 } 5525 5526 static int bpf_btf_get_info_by_fd(struct file *file, 5527 struct btf *btf, 5528 const union bpf_attr *attr, 5529 union bpf_attr __user *uattr) 5530 { 5531 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5532 u32 info_len = attr->info.info_len; 5533 int err; 5534 5535 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5536 if (err) 5537 return err; 5538 5539 return btf_get_info_by_fd(btf, attr, uattr); 5540 } 5541 5542 static int bpf_link_get_info_by_fd(struct file *file, 5543 struct bpf_link *link, 5544 const union bpf_attr *attr, 5545 union bpf_attr __user *uattr) 5546 { 5547 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5548 struct bpf_link_info info; 5549 const struct bpf_prog *prog; 5550 u32 info_len = attr->info.info_len; 5551 int err; 5552 5553 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5554 if (err) 5555 return err; 5556 info_len = min_t(u32, sizeof(info), info_len); 5557 5558 memset(&info, 0, sizeof(info)); 5559 if (copy_from_user(&info, uinfo, info_len)) 5560 return -EFAULT; 5561 5562 info.type = link->type; 5563 info.id = link->id; 5564 5565 rcu_read_lock(); 5566 prog = READ_ONCE(link->prog); 5567 if (prog) 5568 info.prog_id = prog->aux->id; 5569 rcu_read_unlock(); 5570 5571 if (link->ops->fill_link_info) { 5572 err = link->ops->fill_link_info(link, &info); 5573 if (err) 5574 return err; 5575 } 5576 5577 if (copy_to_user(uinfo, &info, info_len) || 5578 put_user(info_len, &uattr->info.info_len)) 5579 return -EFAULT; 5580 5581 return 0; 5582 } 5583 5584 static int token_get_info_by_fd(struct file *file, 5585 struct bpf_token *token, 5586 const union bpf_attr *attr, 5587 union bpf_attr __user *uattr) 5588 { 5589 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5590 u32 info_len = attr->info.info_len; 5591 int err; 5592 5593 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5594 if (err) 5595 return err; 5596 return bpf_token_get_info_by_fd(token, attr, uattr); 5597 } 5598 5599 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5600 5601 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5602 union bpf_attr __user *uattr) 5603 { 5604 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5605 return -EINVAL; 5606 5607 CLASS(fd, f)(attr->info.bpf_fd); 5608 if (fd_empty(f)) 5609 return -EBADFD; 5610 5611 if (fd_file(f)->f_op == &bpf_prog_fops) 5612 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5613 uattr); 5614 else if (fd_file(f)->f_op == &bpf_map_fops) 5615 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5616 uattr); 5617 else if (fd_file(f)->f_op == &btf_fops) 5618 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5619 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5620 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5621 attr, uattr); 5622 else if (fd_file(f)->f_op == &bpf_token_fops) 5623 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5624 attr, uattr); 5625 return -EINVAL; 5626 } 5627 5628 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5629 5630 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 5631 { 5632 struct bpf_token *token = NULL; 5633 5634 if (CHECK_ATTR(BPF_BTF_LOAD)) 5635 return -EINVAL; 5636 5637 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5638 return -EINVAL; 5639 5640 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5641 token = bpf_token_get_from_fd(attr->btf_token_fd); 5642 if (IS_ERR(token)) 5643 return PTR_ERR(token); 5644 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5645 bpf_token_put(token); 5646 token = NULL; 5647 } 5648 } 5649 5650 if (!bpf_token_capable(token, CAP_BPF)) { 5651 bpf_token_put(token); 5652 return -EPERM; 5653 } 5654 5655 bpf_token_put(token); 5656 5657 return btf_new_fd(attr, uattr, attr_log); 5658 } 5659 5660 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd 5661 5662 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5663 { 5664 struct bpf_token *token = NULL; 5665 5666 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5667 return -EINVAL; 5668 5669 if (attr->open_flags & ~BPF_F_TOKEN_FD) 5670 return -EINVAL; 5671 5672 if (attr->open_flags & BPF_F_TOKEN_FD) { 5673 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); 5674 if (IS_ERR(token)) 5675 return PTR_ERR(token); 5676 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { 5677 bpf_token_put(token); 5678 token = NULL; 5679 } 5680 } 5681 5682 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { 5683 bpf_token_put(token); 5684 return -EPERM; 5685 } 5686 5687 bpf_token_put(token); 5688 5689 return btf_get_fd_by_id(attr->btf_id); 5690 } 5691 5692 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5693 union bpf_attr __user *uattr, 5694 u32 prog_id, u32 fd_type, 5695 const char *buf, u64 probe_offset, 5696 u64 probe_addr) 5697 { 5698 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5699 u32 len = buf ? strlen(buf) : 0, input_len; 5700 int err = 0; 5701 5702 if (put_user(len, &uattr->task_fd_query.buf_len)) 5703 return -EFAULT; 5704 input_len = attr->task_fd_query.buf_len; 5705 if (input_len && ubuf) { 5706 if (!len) { 5707 /* nothing to copy, just make ubuf NULL terminated */ 5708 char zero = '\0'; 5709 5710 if (put_user(zero, ubuf)) 5711 return -EFAULT; 5712 } else { 5713 err = bpf_copy_to_user(ubuf, buf, input_len, len); 5714 if (err == -EFAULT) 5715 return err; 5716 } 5717 } 5718 5719 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5720 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5721 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5722 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5723 return -EFAULT; 5724 5725 return err; 5726 } 5727 5728 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5729 5730 static int bpf_task_fd_query(const union bpf_attr *attr, 5731 union bpf_attr __user *uattr) 5732 { 5733 pid_t pid = attr->task_fd_query.pid; 5734 u32 fd = attr->task_fd_query.fd; 5735 const struct perf_event *event; 5736 struct task_struct *task; 5737 struct file *file; 5738 int err; 5739 5740 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5741 return -EINVAL; 5742 5743 if (!capable(CAP_SYS_ADMIN)) 5744 return -EPERM; 5745 5746 if (attr->task_fd_query.flags != 0) 5747 return -EINVAL; 5748 5749 rcu_read_lock(); 5750 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5751 rcu_read_unlock(); 5752 if (!task) 5753 return -ENOENT; 5754 5755 err = 0; 5756 file = fget_task(task, fd); 5757 put_task_struct(task); 5758 if (!file) 5759 return -EBADF; 5760 5761 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5762 struct bpf_link *link = file->private_data; 5763 5764 if (link->ops == &bpf_raw_tp_link_lops) { 5765 struct bpf_raw_tp_link *raw_tp = 5766 container_of(link, struct bpf_raw_tp_link, link); 5767 struct bpf_raw_event_map *btp = raw_tp->btp; 5768 5769 err = bpf_task_fd_query_copy(attr, uattr, 5770 raw_tp->link.prog->aux->id, 5771 BPF_FD_TYPE_RAW_TRACEPOINT, 5772 btp->tp->name, 0, 0); 5773 goto put_file; 5774 } 5775 goto out_not_supp; 5776 } 5777 5778 event = perf_get_event(file); 5779 if (!IS_ERR(event)) { 5780 u64 probe_offset, probe_addr; 5781 u32 prog_id, fd_type; 5782 const char *buf; 5783 5784 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5785 &buf, &probe_offset, 5786 &probe_addr, NULL); 5787 if (!err) { 5788 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5789 fd_type, buf, 5790 probe_offset, 5791 probe_addr); 5792 kfree_const(buf); 5793 } 5794 goto put_file; 5795 } 5796 5797 out_not_supp: 5798 err = -ENOTSUPP; 5799 put_file: 5800 fput(file); 5801 return err; 5802 } 5803 5804 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5805 5806 #define BPF_DO_BATCH(fn, ...) \ 5807 do { \ 5808 if (!fn) { \ 5809 err = -ENOTSUPP; \ 5810 goto err_put; \ 5811 } \ 5812 err = fn(__VA_ARGS__); \ 5813 } while (0) 5814 5815 static int bpf_map_do_batch(const union bpf_attr *attr, 5816 union bpf_attr __user *uattr, 5817 int cmd) 5818 { 5819 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5820 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5821 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5822 struct bpf_map *map; 5823 int err; 5824 5825 if (CHECK_ATTR(BPF_MAP_BATCH)) 5826 return -EINVAL; 5827 5828 CLASS(fd, f)(attr->batch.map_fd); 5829 5830 map = __bpf_map_get(f); 5831 if (IS_ERR(map)) 5832 return PTR_ERR(map); 5833 if (has_write) 5834 bpf_map_write_active_inc(map); 5835 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5836 err = -EPERM; 5837 goto err_put; 5838 } 5839 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5840 err = -EPERM; 5841 goto err_put; 5842 } 5843 5844 if (cmd == BPF_MAP_LOOKUP_BATCH) 5845 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5846 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5847 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5848 else if (cmd == BPF_MAP_UPDATE_BATCH) 5849 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5850 else 5851 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5852 err_put: 5853 if (has_write) { 5854 maybe_wait_bpf_programs(map); 5855 bpf_map_write_active_dec(map); 5856 } 5857 return err; 5858 } 5859 5860 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.path_fd 5861 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5862 { 5863 struct bpf_prog *prog; 5864 int ret; 5865 5866 if (CHECK_ATTR(BPF_LINK_CREATE)) 5867 return -EINVAL; 5868 5869 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5870 return bpf_struct_ops_link_create(attr); 5871 5872 prog = bpf_prog_get(attr->link_create.prog_fd); 5873 if (IS_ERR(prog)) 5874 return PTR_ERR(prog); 5875 5876 ret = bpf_prog_attach_check_attach_type(prog, 5877 attr->link_create.attach_type); 5878 if (ret) 5879 goto out; 5880 5881 switch (prog->type) { 5882 case BPF_PROG_TYPE_CGROUP_SKB: 5883 case BPF_PROG_TYPE_CGROUP_SOCK: 5884 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5885 case BPF_PROG_TYPE_SOCK_OPS: 5886 case BPF_PROG_TYPE_CGROUP_DEVICE: 5887 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5888 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5889 ret = cgroup_bpf_link_attach(attr, prog); 5890 break; 5891 case BPF_PROG_TYPE_EXT: 5892 ret = bpf_tracing_prog_attach(prog, 5893 attr->link_create.target_fd, 5894 attr->link_create.target_btf_id, 5895 attr->link_create.tracing.cookie, 5896 attr->link_create.attach_type); 5897 break; 5898 case BPF_PROG_TYPE_LSM: 5899 case BPF_PROG_TYPE_TRACING: 5900 if (attr->link_create.attach_type != prog->expected_attach_type) { 5901 ret = -EINVAL; 5902 goto out; 5903 } 5904 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5905 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, 5906 attr->link_create.attach_type); 5907 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5908 ret = bpf_iter_link_attach(attr, uattr, prog); 5909 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5910 ret = cgroup_bpf_link_attach(attr, prog); 5911 else if (is_tracing_multi(prog->expected_attach_type)) 5912 ret = bpf_tracing_multi_attach(prog, attr); 5913 else 5914 ret = bpf_tracing_prog_attach(prog, 5915 attr->link_create.target_fd, 5916 attr->link_create.target_btf_id, 5917 attr->link_create.tracing.cookie, 5918 attr->link_create.attach_type); 5919 break; 5920 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5921 case BPF_PROG_TYPE_SK_LOOKUP: 5922 ret = netns_bpf_link_create(attr, prog); 5923 break; 5924 case BPF_PROG_TYPE_SK_MSG: 5925 case BPF_PROG_TYPE_SK_SKB: 5926 ret = sock_map_link_create(attr, prog); 5927 break; 5928 #ifdef CONFIG_NET 5929 case BPF_PROG_TYPE_XDP: 5930 ret = bpf_xdp_link_attach(attr, prog); 5931 break; 5932 case BPF_PROG_TYPE_SCHED_CLS: 5933 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5934 attr->link_create.attach_type == BPF_TCX_EGRESS) 5935 ret = tcx_link_attach(attr, prog); 5936 else 5937 ret = netkit_link_attach(attr, prog); 5938 break; 5939 case BPF_PROG_TYPE_NETFILTER: 5940 ret = bpf_nf_link_attach(attr, prog); 5941 break; 5942 #endif 5943 case BPF_PROG_TYPE_PERF_EVENT: 5944 case BPF_PROG_TYPE_TRACEPOINT: 5945 ret = bpf_perf_link_attach(attr, prog); 5946 break; 5947 case BPF_PROG_TYPE_KPROBE: 5948 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5949 ret = bpf_perf_link_attach(attr, prog); 5950 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5951 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5952 ret = bpf_kprobe_multi_link_attach(attr, prog); 5953 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5954 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5955 ret = bpf_uprobe_multi_link_attach(attr, prog); 5956 break; 5957 default: 5958 ret = -EINVAL; 5959 } 5960 5961 out: 5962 if (ret < 0) 5963 bpf_prog_put(prog); 5964 return ret; 5965 } 5966 5967 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5968 { 5969 struct bpf_map *new_map, *old_map = NULL; 5970 int ret; 5971 5972 new_map = bpf_map_get(attr->link_update.new_map_fd); 5973 if (IS_ERR(new_map)) 5974 return PTR_ERR(new_map); 5975 5976 if (attr->link_update.flags & BPF_F_REPLACE) { 5977 old_map = bpf_map_get(attr->link_update.old_map_fd); 5978 if (IS_ERR(old_map)) { 5979 ret = PTR_ERR(old_map); 5980 goto out_put; 5981 } 5982 } else if (attr->link_update.old_map_fd) { 5983 ret = -EINVAL; 5984 goto out_put; 5985 } 5986 5987 ret = link->ops->update_map(link, new_map, old_map); 5988 5989 if (old_map) 5990 bpf_map_put(old_map); 5991 out_put: 5992 bpf_map_put(new_map); 5993 return ret; 5994 } 5995 5996 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5997 5998 static int link_update(union bpf_attr *attr) 5999 { 6000 struct bpf_prog *old_prog = NULL, *new_prog; 6001 struct bpf_link *link; 6002 u32 flags; 6003 int ret; 6004 6005 if (CHECK_ATTR(BPF_LINK_UPDATE)) 6006 return -EINVAL; 6007 6008 flags = attr->link_update.flags; 6009 if (flags & ~BPF_F_REPLACE) 6010 return -EINVAL; 6011 6012 link = bpf_link_get_from_fd(attr->link_update.link_fd); 6013 if (IS_ERR(link)) 6014 return PTR_ERR(link); 6015 6016 if (link->ops->update_map) { 6017 ret = link_update_map(link, attr); 6018 goto out_put_link; 6019 } 6020 6021 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 6022 if (IS_ERR(new_prog)) { 6023 ret = PTR_ERR(new_prog); 6024 goto out_put_link; 6025 } 6026 6027 if (flags & BPF_F_REPLACE) { 6028 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 6029 if (IS_ERR(old_prog)) { 6030 ret = PTR_ERR(old_prog); 6031 old_prog = NULL; 6032 goto out_put_progs; 6033 } 6034 } else if (attr->link_update.old_prog_fd) { 6035 ret = -EINVAL; 6036 goto out_put_progs; 6037 } 6038 6039 if (link->ops->update_prog) 6040 ret = link->ops->update_prog(link, new_prog, old_prog); 6041 else 6042 ret = -EINVAL; 6043 6044 out_put_progs: 6045 if (old_prog) 6046 bpf_prog_put(old_prog); 6047 if (ret) 6048 bpf_prog_put(new_prog); 6049 out_put_link: 6050 bpf_link_put_direct(link); 6051 return ret; 6052 } 6053 6054 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 6055 6056 static int link_detach(union bpf_attr *attr) 6057 { 6058 struct bpf_link *link; 6059 int ret; 6060 6061 if (CHECK_ATTR(BPF_LINK_DETACH)) 6062 return -EINVAL; 6063 6064 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 6065 if (IS_ERR(link)) 6066 return PTR_ERR(link); 6067 6068 if (link->ops->detach) 6069 ret = link->ops->detach(link); 6070 else 6071 ret = -EOPNOTSUPP; 6072 6073 bpf_link_put_direct(link); 6074 return ret; 6075 } 6076 6077 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 6078 { 6079 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 6080 } 6081 EXPORT_SYMBOL(bpf_link_inc_not_zero); 6082 6083 struct bpf_link *bpf_link_by_id(u32 id) 6084 { 6085 struct bpf_link *link; 6086 6087 if (!id) 6088 return ERR_PTR(-ENOENT); 6089 6090 spin_lock_bh(&link_idr_lock); 6091 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 6092 link = idr_find(&link_idr, id); 6093 if (link) { 6094 if (link->id) 6095 link = bpf_link_inc_not_zero(link); 6096 else 6097 link = ERR_PTR(-EAGAIN); 6098 } else { 6099 link = ERR_PTR(-ENOENT); 6100 } 6101 spin_unlock_bh(&link_idr_lock); 6102 return link; 6103 } 6104 6105 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 6106 { 6107 struct bpf_link *link; 6108 6109 spin_lock_bh(&link_idr_lock); 6110 again: 6111 link = idr_get_next(&link_idr, id); 6112 if (link) { 6113 if (link->id) 6114 link = bpf_link_inc_not_zero(link); 6115 else 6116 link = ERR_PTR(-EAGAIN); 6117 if (IS_ERR(link)) { 6118 (*id)++; 6119 goto again; 6120 } 6121 } 6122 spin_unlock_bh(&link_idr_lock); 6123 6124 return link; 6125 } 6126 6127 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 6128 6129 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 6130 { 6131 struct bpf_link *link; 6132 u32 id = attr->link_id; 6133 int fd; 6134 6135 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 6136 return -EINVAL; 6137 6138 if (!capable(CAP_SYS_ADMIN)) 6139 return -EPERM; 6140 6141 link = bpf_link_by_id(id); 6142 if (IS_ERR(link)) 6143 return PTR_ERR(link); 6144 6145 fd = bpf_link_new_fd(link); 6146 if (fd < 0) 6147 bpf_link_put_direct(link); 6148 6149 return fd; 6150 } 6151 6152 DEFINE_MUTEX(bpf_stats_enabled_mutex); 6153 6154 static int bpf_stats_release(struct inode *inode, struct file *file) 6155 { 6156 mutex_lock(&bpf_stats_enabled_mutex); 6157 static_key_slow_dec(&bpf_stats_enabled_key.key); 6158 mutex_unlock(&bpf_stats_enabled_mutex); 6159 return 0; 6160 } 6161 6162 static const struct file_operations bpf_stats_fops = { 6163 .release = bpf_stats_release, 6164 }; 6165 6166 static int bpf_enable_runtime_stats(void) 6167 { 6168 int fd; 6169 6170 mutex_lock(&bpf_stats_enabled_mutex); 6171 6172 /* Set a very high limit to avoid overflow */ 6173 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 6174 mutex_unlock(&bpf_stats_enabled_mutex); 6175 return -EBUSY; 6176 } 6177 6178 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 6179 if (fd >= 0) 6180 static_key_slow_inc(&bpf_stats_enabled_key.key); 6181 6182 mutex_unlock(&bpf_stats_enabled_mutex); 6183 return fd; 6184 } 6185 6186 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 6187 6188 static int bpf_enable_stats(union bpf_attr *attr) 6189 { 6190 6191 if (CHECK_ATTR(BPF_ENABLE_STATS)) 6192 return -EINVAL; 6193 6194 if (!capable(CAP_SYS_ADMIN)) 6195 return -EPERM; 6196 6197 switch (attr->enable_stats.type) { 6198 case BPF_STATS_RUN_TIME: 6199 return bpf_enable_runtime_stats(); 6200 default: 6201 break; 6202 } 6203 return -EINVAL; 6204 } 6205 6206 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 6207 6208 static int bpf_iter_create(union bpf_attr *attr) 6209 { 6210 struct bpf_link *link; 6211 int err; 6212 6213 if (CHECK_ATTR(BPF_ITER_CREATE)) 6214 return -EINVAL; 6215 6216 if (attr->iter_create.flags) 6217 return -EINVAL; 6218 6219 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 6220 if (IS_ERR(link)) 6221 return PTR_ERR(link); 6222 6223 err = bpf_iter_new_fd(link); 6224 bpf_link_put_direct(link); 6225 6226 return err; 6227 } 6228 6229 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 6230 6231 static int bpf_prog_bind_map(union bpf_attr *attr) 6232 { 6233 struct bpf_prog *prog; 6234 struct bpf_map *map; 6235 struct bpf_map **used_maps_old, **used_maps_new; 6236 int i, ret = 0; 6237 6238 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 6239 return -EINVAL; 6240 6241 if (attr->prog_bind_map.flags) 6242 return -EINVAL; 6243 6244 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 6245 if (IS_ERR(prog)) 6246 return PTR_ERR(prog); 6247 6248 map = bpf_map_get(attr->prog_bind_map.map_fd); 6249 if (IS_ERR(map)) { 6250 ret = PTR_ERR(map); 6251 goto out_prog_put; 6252 } 6253 6254 mutex_lock(&prog->aux->used_maps_mutex); 6255 6256 used_maps_old = prog->aux->used_maps; 6257 6258 for (i = 0; i < prog->aux->used_map_cnt; i++) 6259 if (used_maps_old[i] == map) { 6260 bpf_map_put(map); 6261 goto out_unlock; 6262 } 6263 6264 used_maps_new = kmalloc_objs(used_maps_new[0], 6265 prog->aux->used_map_cnt + 1); 6266 if (!used_maps_new) { 6267 ret = -ENOMEM; 6268 goto out_unlock; 6269 } 6270 6271 /* The bpf program will not access the bpf map, but for the sake of 6272 * simplicity, increase sleepable_refcnt for sleepable program as well. 6273 */ 6274 if (bpf_prog_runs_sleepable(prog)) 6275 atomic64_inc(&map->sleepable_refcnt); 6276 memcpy(used_maps_new, used_maps_old, 6277 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 6278 used_maps_new[prog->aux->used_map_cnt] = map; 6279 6280 prog->aux->used_map_cnt++; 6281 prog->aux->used_maps = used_maps_new; 6282 6283 kfree(used_maps_old); 6284 6285 out_unlock: 6286 mutex_unlock(&prog->aux->used_maps_mutex); 6287 6288 if (ret) 6289 bpf_map_put(map); 6290 out_prog_put: 6291 bpf_prog_put(prog); 6292 return ret; 6293 } 6294 6295 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 6296 6297 static int token_create(union bpf_attr *attr) 6298 { 6299 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 6300 return -EINVAL; 6301 6302 /* no flags are supported yet */ 6303 if (attr->token_create.flags) 6304 return -EINVAL; 6305 6306 return bpf_token_create(attr); 6307 } 6308 6309 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd 6310 6311 static int prog_stream_read(union bpf_attr *attr) 6312 { 6313 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); 6314 u32 len = attr->prog_stream_read.stream_buf_len; 6315 struct bpf_prog *prog; 6316 int ret; 6317 6318 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) 6319 return -EINVAL; 6320 6321 prog = bpf_prog_get(attr->prog_stream_read.prog_fd); 6322 if (IS_ERR(prog)) 6323 return PTR_ERR(prog); 6324 6325 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); 6326 bpf_prog_put(prog); 6327 6328 return ret; 6329 } 6330 6331 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.flags 6332 6333 static int prog_assoc_struct_ops(union bpf_attr *attr) 6334 { 6335 struct bpf_prog *prog; 6336 struct bpf_map *map; 6337 int ret; 6338 6339 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS)) 6340 return -EINVAL; 6341 6342 if (attr->prog_assoc_struct_ops.flags) 6343 return -EINVAL; 6344 6345 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd); 6346 if (IS_ERR(prog)) 6347 return PTR_ERR(prog); 6348 6349 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) { 6350 ret = -EINVAL; 6351 goto put_prog; 6352 } 6353 6354 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd); 6355 if (IS_ERR(map)) { 6356 ret = PTR_ERR(map); 6357 goto put_prog; 6358 } 6359 6360 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 6361 ret = -EINVAL; 6362 goto put_map; 6363 } 6364 6365 ret = bpf_prog_assoc_struct_ops(prog, map); 6366 6367 put_map: 6368 bpf_map_put(map); 6369 put_prog: 6370 bpf_prog_put(prog); 6371 return ret; 6372 } 6373 6374 #define BPF_PROG_STREAM_OPEN_LAST_FIELD prog_stream_open.flags 6375 6376 static int prog_stream_open(union bpf_attr *attr) 6377 { 6378 struct bpf_prog *prog; 6379 u32 flags = attr->prog_stream_open.flags; 6380 int ret; 6381 6382 if (CHECK_ATTR(BPF_PROG_STREAM_OPEN)) 6383 return -EINVAL; 6384 if (flags & ~BPF_F_STREAM_NONBLOCK) 6385 return -EINVAL; 6386 6387 prog = bpf_prog_get(attr->prog_stream_open.prog_fd); 6388 if (IS_ERR(prog)) 6389 return PTR_ERR(prog); 6390 6391 ret = bpf_prog_stream_new_fd(prog, attr->prog_stream_open.stream_id, flags); 6392 bpf_prog_put(prog); 6393 return ret; 6394 } 6395 6396 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, 6397 bpfptr_t uattr_common, unsigned int size_common) 6398 { 6399 struct bpf_common_attr attr_common; 6400 u32 offsetof_log_true_size = 0; 6401 struct bpf_log_attr attr_log; 6402 union bpf_attr attr; 6403 int err; 6404 6405 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 6406 if (err) 6407 return err; 6408 size = min_t(u32, size, sizeof(attr)); 6409 6410 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 6411 memset(&attr, 0, sizeof(attr)); 6412 if (copy_from_bpfptr(&attr, uattr, size) != 0) 6413 return -EFAULT; 6414 6415 memset(&attr_common, 0, sizeof(attr_common)); 6416 if (cmd & BPF_COMMON_ATTRS) { 6417 err = bpf_check_uarg_tail_zero(uattr_common, 6418 offsetofend(struct bpf_common_attr, log_true_size), 6419 size_common); 6420 if (err) 6421 return err; 6422 6423 cmd &= ~BPF_COMMON_ATTRS; 6424 size_common = min_t(u32, size_common, sizeof(attr_common)); 6425 if (copy_from_bpfptr(&attr_common, uattr_common, size_common) != 0) 6426 return -EFAULT; 6427 } else { 6428 size_common = 0; 6429 } 6430 6431 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 6432 if (err < 0) 6433 return err; 6434 6435 switch (cmd) { 6436 case BPF_MAP_CREATE: 6437 err = map_create(&attr, uattr, &attr_common, uattr_common, size_common); 6438 break; 6439 case BPF_MAP_LOOKUP_ELEM: 6440 err = map_lookup_elem(&attr); 6441 break; 6442 case BPF_MAP_UPDATE_ELEM: 6443 err = map_update_elem(&attr, uattr); 6444 break; 6445 case BPF_MAP_DELETE_ELEM: 6446 err = map_delete_elem(&attr, uattr); 6447 break; 6448 case BPF_MAP_GET_NEXT_KEY: 6449 err = map_get_next_key(&attr); 6450 break; 6451 case BPF_MAP_FREEZE: 6452 err = map_freeze(&attr); 6453 break; 6454 case BPF_PROG_LOAD: 6455 if (size >= offsetofend(union bpf_attr, log_true_size)) 6456 offsetof_log_true_size = offsetof(union bpf_attr, log_true_size); 6457 err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level, 6458 offsetof_log_true_size, uattr, &attr_common, uattr_common, 6459 size_common); 6460 err = err ?: bpf_prog_load(&attr, uattr, &attr_log); 6461 break; 6462 case BPF_OBJ_PIN: 6463 err = bpf_obj_pin(&attr); 6464 break; 6465 case BPF_OBJ_GET: 6466 err = bpf_obj_get(&attr); 6467 break; 6468 case BPF_PROG_ATTACH: 6469 err = bpf_prog_attach(&attr); 6470 break; 6471 case BPF_PROG_DETACH: 6472 err = bpf_prog_detach(&attr); 6473 break; 6474 case BPF_PROG_QUERY: 6475 err = bpf_prog_query(&attr, uattr.user, size); 6476 break; 6477 case BPF_PROG_TEST_RUN: 6478 err = bpf_prog_test_run(&attr, uattr.user); 6479 break; 6480 case BPF_PROG_GET_NEXT_ID: 6481 err = bpf_obj_get_next_id(&attr, uattr.user, 6482 &prog_idr, &prog_idr_lock); 6483 break; 6484 case BPF_MAP_GET_NEXT_ID: 6485 err = bpf_obj_get_next_id(&attr, uattr.user, 6486 &map_idr, &map_idr_lock); 6487 break; 6488 case BPF_BTF_GET_NEXT_ID: 6489 err = bpf_obj_get_next_id(&attr, uattr.user, 6490 &btf_idr, &btf_idr_lock); 6491 break; 6492 case BPF_PROG_GET_FD_BY_ID: 6493 err = bpf_prog_get_fd_by_id(&attr); 6494 break; 6495 case BPF_MAP_GET_FD_BY_ID: 6496 err = bpf_map_get_fd_by_id(&attr); 6497 break; 6498 case BPF_OBJ_GET_INFO_BY_FD: 6499 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 6500 break; 6501 case BPF_RAW_TRACEPOINT_OPEN: 6502 err = bpf_raw_tracepoint_open(&attr); 6503 break; 6504 case BPF_BTF_LOAD: 6505 if (size >= offsetofend(union bpf_attr, btf_log_true_size)) 6506 offsetof_log_true_size = offsetof(union bpf_attr, btf_log_true_size); 6507 err = bpf_log_attr_init(&attr_log, attr.btf_log_buf, attr.btf_log_size, 6508 attr.btf_log_level, offsetof_log_true_size, uattr, 6509 &attr_common, uattr_common, size_common); 6510 err = err ?: bpf_btf_load(&attr, uattr, &attr_log); 6511 break; 6512 case BPF_BTF_GET_FD_BY_ID: 6513 err = bpf_btf_get_fd_by_id(&attr); 6514 break; 6515 case BPF_TASK_FD_QUERY: 6516 err = bpf_task_fd_query(&attr, uattr.user); 6517 break; 6518 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 6519 err = map_lookup_and_delete_elem(&attr); 6520 break; 6521 case BPF_MAP_LOOKUP_BATCH: 6522 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 6523 break; 6524 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 6525 err = bpf_map_do_batch(&attr, uattr.user, 6526 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 6527 break; 6528 case BPF_MAP_UPDATE_BATCH: 6529 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 6530 break; 6531 case BPF_MAP_DELETE_BATCH: 6532 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 6533 break; 6534 case BPF_LINK_CREATE: 6535 err = link_create(&attr, uattr); 6536 break; 6537 case BPF_LINK_UPDATE: 6538 err = link_update(&attr); 6539 break; 6540 case BPF_LINK_GET_FD_BY_ID: 6541 err = bpf_link_get_fd_by_id(&attr); 6542 break; 6543 case BPF_LINK_GET_NEXT_ID: 6544 err = bpf_obj_get_next_id(&attr, uattr.user, 6545 &link_idr, &link_idr_lock); 6546 break; 6547 case BPF_ENABLE_STATS: 6548 err = bpf_enable_stats(&attr); 6549 break; 6550 case BPF_ITER_CREATE: 6551 err = bpf_iter_create(&attr); 6552 break; 6553 case BPF_LINK_DETACH: 6554 err = link_detach(&attr); 6555 break; 6556 case BPF_PROG_BIND_MAP: 6557 err = bpf_prog_bind_map(&attr); 6558 break; 6559 case BPF_TOKEN_CREATE: 6560 err = token_create(&attr); 6561 break; 6562 case BPF_PROG_STREAM_READ_BY_FD: 6563 err = prog_stream_read(&attr); 6564 break; 6565 case BPF_PROG_ASSOC_STRUCT_OPS: 6566 err = prog_assoc_struct_ops(&attr); 6567 break; 6568 case BPF_PROG_STREAM_OPEN: 6569 err = prog_stream_open(&attr); 6570 break; 6571 default: 6572 err = -EINVAL; 6573 break; 6574 } 6575 6576 return err; 6577 } 6578 6579 SYSCALL_DEFINE5(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size, 6580 struct bpf_common_attr __user *, uattr_common, unsigned int, size_common) 6581 { 6582 return __sys_bpf(cmd, USER_BPFPTR(uattr), size, USER_BPFPTR(uattr_common), size_common); 6583 } 6584 6585 static bool syscall_prog_is_valid_access(int off, int size, 6586 enum bpf_access_type type, 6587 const struct bpf_prog *prog, 6588 struct bpf_insn_access_aux *info) 6589 { 6590 if (off < 0 || off >= U16_MAX) 6591 return false; 6592 /* No alignment requirements for syscall ctx accesses. */ 6593 return true; 6594 } 6595 6596 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 6597 { 6598 switch (cmd) { 6599 case BPF_MAP_CREATE: 6600 case BPF_MAP_DELETE_ELEM: 6601 case BPF_MAP_UPDATE_ELEM: 6602 case BPF_MAP_FREEZE: 6603 case BPF_MAP_GET_FD_BY_ID: 6604 case BPF_PROG_LOAD: 6605 case BPF_BTF_LOAD: 6606 case BPF_LINK_CREATE: 6607 case BPF_RAW_TRACEPOINT_OPEN: 6608 break; 6609 default: 6610 return -EINVAL; 6611 } 6612 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size, KERNEL_BPFPTR(NULL), 0); 6613 } 6614 6615 /* To shut up -Wmissing-prototypes. 6616 * This function is used by the kernel light skeleton 6617 * to load bpf programs when modules are loaded or during kernel boot. 6618 * See tools/lib/bpf/skel_internal.h 6619 */ 6620 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 6621 6622 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 6623 { 6624 struct bpf_prog * __maybe_unused prog; 6625 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 6626 6627 switch (cmd) { 6628 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 6629 case BPF_PROG_TEST_RUN: 6630 if (attr->test.data_in || attr->test.data_out || 6631 attr->test.ctx_out || attr->test.duration || 6632 attr->test.repeat || attr->test.flags) 6633 return -EINVAL; 6634 6635 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 6636 if (IS_ERR(prog)) 6637 return PTR_ERR(prog); 6638 6639 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 6640 attr->test.ctx_size_in > U16_MAX) { 6641 bpf_prog_put(prog); 6642 return -EINVAL; 6643 } 6644 6645 run_ctx.bpf_cookie = 0; 6646 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 6647 /* recursion detected */ 6648 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 6649 bpf_prog_put(prog); 6650 return -EBUSY; 6651 } 6652 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 6653 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 6654 &run_ctx); 6655 bpf_prog_put(prog); 6656 return 0; 6657 #endif 6658 default: 6659 return ____bpf_sys_bpf(cmd, attr, size); 6660 } 6661 } 6662 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); 6663 6664 static const struct bpf_func_proto bpf_sys_bpf_proto = { 6665 .func = bpf_sys_bpf, 6666 .gpl_only = false, 6667 .might_sleep = true, 6668 .ret_type = RET_INTEGER, 6669 .arg1_type = ARG_ANYTHING, 6670 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6671 .arg3_type = ARG_MEM_SIZE, 6672 }; 6673 6674 const struct bpf_func_proto * __weak 6675 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6676 { 6677 return bpf_base_func_proto(func_id, prog); 6678 } 6679 6680 BPF_CALL_1(bpf_sys_close, u32, fd) 6681 { 6682 /* When bpf program calls this helper there should not be 6683 * an fdget() without matching completed fdput(). 6684 * This helper is allowed in the following callchain only: 6685 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6686 */ 6687 return close_fd(fd); 6688 } 6689 6690 static const struct bpf_func_proto bpf_sys_close_proto = { 6691 .func = bpf_sys_close, 6692 .gpl_only = false, 6693 .might_sleep = true, 6694 .ret_type = RET_INTEGER, 6695 .arg1_type = ARG_ANYTHING, 6696 }; 6697 6698 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6699 { 6700 *res = 0; 6701 if (flags) 6702 return -EINVAL; 6703 6704 if (name_sz <= 1 || name[name_sz - 1]) 6705 return -EINVAL; 6706 6707 if (!bpf_dump_raw_ok(current_cred())) 6708 return -EPERM; 6709 6710 *res = kallsyms_lookup_name(name); 6711 return *res ? 0 : -ENOENT; 6712 } 6713 6714 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6715 .func = bpf_kallsyms_lookup_name, 6716 .gpl_only = false, 6717 .ret_type = RET_INTEGER, 6718 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6719 .arg2_type = ARG_MEM_SIZE_OR_ZERO, 6720 .arg3_type = ARG_ANYTHING, 6721 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6722 .arg4_size = sizeof(u64), 6723 }; 6724 6725 static const struct bpf_func_proto * 6726 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6727 { 6728 switch (func_id) { 6729 case BPF_FUNC_sys_bpf: 6730 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6731 ? NULL : &bpf_sys_bpf_proto; 6732 case BPF_FUNC_btf_find_by_name_kind: 6733 return &bpf_btf_find_by_name_kind_proto; 6734 case BPF_FUNC_sys_close: 6735 return &bpf_sys_close_proto; 6736 case BPF_FUNC_kallsyms_lookup_name: 6737 return &bpf_kallsyms_lookup_name_proto; 6738 default: 6739 return tracing_prog_func_proto(func_id, prog); 6740 } 6741 } 6742 6743 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6744 .get_func_proto = syscall_prog_func_proto, 6745 .is_valid_access = syscall_prog_is_valid_access, 6746 }; 6747 6748 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6749 .test_run = bpf_prog_test_run_syscall, 6750 }; 6751 6752 #ifdef CONFIG_SYSCTL 6753 static int bpf_stats_handler(const struct ctl_table *table, int write, 6754 void *buffer, size_t *lenp, loff_t *ppos) 6755 { 6756 struct static_key *key = (struct static_key *)table->data; 6757 static int saved_val; 6758 int val, ret; 6759 struct ctl_table tmp = { 6760 .data = &val, 6761 .maxlen = sizeof(val), 6762 .mode = table->mode, 6763 .extra1 = SYSCTL_ZERO, 6764 .extra2 = SYSCTL_ONE, 6765 }; 6766 6767 if (write && !capable(CAP_SYS_ADMIN)) 6768 return -EPERM; 6769 6770 mutex_lock(&bpf_stats_enabled_mutex); 6771 val = saved_val; 6772 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6773 if (write && !ret && val != saved_val) { 6774 if (val) 6775 static_key_slow_inc(key); 6776 else 6777 static_key_slow_dec(key); 6778 saved_val = val; 6779 } 6780 mutex_unlock(&bpf_stats_enabled_mutex); 6781 return ret; 6782 } 6783 6784 void __weak unpriv_ebpf_notify(int new_state) 6785 { 6786 } 6787 6788 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6789 void *buffer, size_t *lenp, loff_t *ppos) 6790 { 6791 int ret, unpriv_enable = *(int *)table->data; 6792 bool locked_state = unpriv_enable == 1; 6793 struct ctl_table tmp = *table; 6794 6795 if (write && !capable(CAP_SYS_ADMIN)) 6796 return -EPERM; 6797 6798 tmp.data = &unpriv_enable; 6799 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6800 if (write && !ret) { 6801 if (locked_state && unpriv_enable != 1) 6802 return -EPERM; 6803 *(int *)table->data = unpriv_enable; 6804 } 6805 6806 if (write) 6807 unpriv_ebpf_notify(unpriv_enable); 6808 6809 return ret; 6810 } 6811 6812 static const struct ctl_table bpf_syscall_table[] = { 6813 { 6814 .procname = "unprivileged_bpf_disabled", 6815 .data = &sysctl_unprivileged_bpf_disabled, 6816 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6817 .mode = 0644, 6818 .proc_handler = bpf_unpriv_handler, 6819 .extra1 = SYSCTL_ZERO, 6820 .extra2 = SYSCTL_TWO, 6821 }, 6822 { 6823 .procname = "bpf_stats_enabled", 6824 .data = &bpf_stats_enabled_key.key, 6825 .mode = 0644, 6826 .proc_handler = bpf_stats_handler, 6827 }, 6828 }; 6829 6830 static int __init bpf_syscall_sysctl_init(void) 6831 { 6832 register_sysctl_init("kernel", bpf_syscall_table); 6833 return 0; 6834 } 6835 late_initcall(bpf_syscall_sysctl_init); 6836 #endif /* CONFIG_SYSCTL */ 6837