1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 */ 4 #include <crypto/sha2.h> 5 #include <linux/bpf.h> 6 #include <linux/bpf-cgroup.h> 7 #include <linux/bpf_trace.h> 8 #include <linux/bpf_lirc.h> 9 #include <linux/bpf_verifier.h> 10 #include <linux/bsearch.h> 11 #include <linux/btf.h> 12 #include <linux/hex.h> 13 #include <linux/syscalls.h> 14 #include <linux/slab.h> 15 #include <linux/sched/signal.h> 16 #include <linux/vmalloc.h> 17 #include <linux/mmzone.h> 18 #include <linux/anon_inodes.h> 19 #include <linux/fdtable.h> 20 #include <linux/file.h> 21 #include <linux/fs.h> 22 #include <linux/license.h> 23 #include <linux/filter.h> 24 #include <linux/kernel.h> 25 #include <linux/idr.h> 26 #include <linux/cred.h> 27 #include <linux/timekeeping.h> 28 #include <linux/ctype.h> 29 #include <linux/nospec.h> 30 #include <linux/audit.h> 31 #include <uapi/linux/btf.h> 32 #include <linux/pgtable.h> 33 #include <linux/bpf_lsm.h> 34 #include <linux/poll.h> 35 #include <linux/sort.h> 36 #include <linux/bpf-netns.h> 37 #include <linux/rcupdate_trace.h> 38 #include <linux/memcontrol.h> 39 #include <linux/trace_events.h> 40 #include <linux/tracepoint.h> 41 #include <linux/overflow.h> 42 #include <linux/cookie.h> 43 #include <linux/verification.h> 44 45 #include <net/netfilter/nf_bpf_link.h> 46 #include <net/netkit.h> 47 #include <net/tcx.h> 48 49 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ 50 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ 51 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 52 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) 53 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) 54 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ 55 IS_FD_HASH(map)) 56 57 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) 58 59 DEFINE_PER_CPU(int, bpf_prog_active); 60 DEFINE_COOKIE(bpf_map_cookie); 61 static DEFINE_IDR(prog_idr); 62 static DEFINE_SPINLOCK(prog_idr_lock); 63 static DEFINE_IDR(map_idr); 64 static DEFINE_SPINLOCK(map_idr_lock); 65 static DEFINE_IDR(link_idr); 66 static DEFINE_SPINLOCK(link_idr_lock); 67 68 int sysctl_unprivileged_bpf_disabled __read_mostly = 69 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; 70 71 static const struct bpf_map_ops * const bpf_map_types[] = { 72 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 73 #define BPF_MAP_TYPE(_id, _ops) \ 74 [_id] = &_ops, 75 #define BPF_LINK_TYPE(_id, _name) 76 #include <linux/bpf_types.h> 77 #undef BPF_PROG_TYPE 78 #undef BPF_MAP_TYPE 79 #undef BPF_LINK_TYPE 80 }; 81 82 /* 83 * If we're handed a bigger struct than we know of, ensure all the unknown bits 84 * are 0 - i.e. new user-space does not rely on any kernel feature extensions 85 * we don't know about yet. 86 * 87 * There is a ToCToU between this function call and the following 88 * copy_from_user() call. However, this is not a concern since this function is 89 * meant to be a future-proofing of bits. 90 */ 91 int bpf_check_uarg_tail_zero(bpfptr_t uaddr, 92 size_t expected_size, 93 size_t actual_size) 94 { 95 int res; 96 97 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ 98 return -E2BIG; 99 100 if (actual_size <= expected_size) 101 return 0; 102 103 if (uaddr.is_kernel) 104 res = memchr_inv(uaddr.kernel + expected_size, 0, 105 actual_size - expected_size) == NULL; 106 else 107 res = check_zeroed_user(uaddr.user + expected_size, 108 actual_size - expected_size); 109 if (res < 0) 110 return res; 111 return res ? 0 : -E2BIG; 112 } 113 114 const struct bpf_map_ops bpf_map_offload_ops = { 115 .map_meta_equal = bpf_map_meta_equal, 116 .map_alloc = bpf_map_offload_map_alloc, 117 .map_free = bpf_map_offload_map_free, 118 .map_check_btf = map_check_no_btf, 119 .map_mem_usage = bpf_map_offload_map_mem_usage, 120 }; 121 122 static void bpf_map_write_active_inc(struct bpf_map *map) 123 { 124 atomic64_inc(&map->writecnt); 125 } 126 127 static void bpf_map_write_active_dec(struct bpf_map *map) 128 { 129 atomic64_dec(&map->writecnt); 130 } 131 132 bool bpf_map_write_active(const struct bpf_map *map) 133 { 134 return atomic64_read(&map->writecnt) != 0; 135 } 136 137 static u32 bpf_map_value_size(const struct bpf_map *map, u64 flags) 138 { 139 if (flags & (BPF_F_CPU | BPF_F_ALL_CPUS)) 140 return map->value_size; 141 else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 142 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 143 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || 144 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) 145 return round_up(map->value_size, 8) * num_possible_cpus(); 146 else if (IS_FD_MAP(map)) 147 return sizeof(u32); 148 else 149 return map->value_size; 150 } 151 152 static void maybe_wait_bpf_programs(struct bpf_map *map) 153 { 154 /* Wait for any running non-sleepable BPF programs to complete so that 155 * userspace, when we return to it, knows that all non-sleepable 156 * programs that could be running use the new map value. For sleepable 157 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait 158 * for the completions of these programs, but considering the waiting 159 * time can be very long and userspace may think it will hang forever, 160 * so don't handle sleepable BPF programs now. 161 */ 162 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || 163 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 164 synchronize_rcu_expedited(); 165 } 166 167 static void unpin_uptr_kaddr(void *kaddr) 168 { 169 if (kaddr) 170 unpin_user_page(virt_to_page(kaddr)); 171 } 172 173 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj) 174 { 175 const struct btf_field *field; 176 void **uptr_addr; 177 int i; 178 179 for (i = 0, field = rec->fields; i < cnt; i++, field++) { 180 if (field->type != BPF_UPTR) 181 continue; 182 183 uptr_addr = obj + field->offset; 184 unpin_uptr_kaddr(*uptr_addr); 185 } 186 } 187 188 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj) 189 { 190 if (!btf_record_has_field(rec, BPF_UPTR)) 191 return; 192 193 __bpf_obj_unpin_uptrs(rec, rec->cnt, obj); 194 } 195 196 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj) 197 { 198 const struct btf_field *field; 199 const struct btf_type *t; 200 unsigned long start, end; 201 struct page *page; 202 void **uptr_addr; 203 int i, err; 204 205 if (!btf_record_has_field(rec, BPF_UPTR)) 206 return 0; 207 208 for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) { 209 if (field->type != BPF_UPTR) 210 continue; 211 212 uptr_addr = obj + field->offset; 213 start = *(unsigned long *)uptr_addr; 214 if (!start) 215 continue; 216 217 t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id); 218 /* t->size was checked for zero before */ 219 if (check_add_overflow(start, t->size - 1, &end)) { 220 err = -EFAULT; 221 goto unpin_all; 222 } 223 224 /* The uptr's struct cannot span across two pages */ 225 if ((start & PAGE_MASK) != (end & PAGE_MASK)) { 226 err = -EOPNOTSUPP; 227 goto unpin_all; 228 } 229 230 err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page); 231 if (err != 1) 232 goto unpin_all; 233 234 if (PageHighMem(page)) { 235 err = -EOPNOTSUPP; 236 unpin_user_page(page); 237 goto unpin_all; 238 } 239 240 *uptr_addr = page_address(page) + offset_in_page(start); 241 } 242 243 return 0; 244 245 unpin_all: 246 __bpf_obj_unpin_uptrs(rec, i, obj); 247 return err; 248 } 249 250 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, 251 void *key, void *value, __u64 flags) 252 { 253 int err; 254 255 /* Need to create a kthread, thus must support schedule */ 256 if (bpf_map_is_offloaded(map)) { 257 return bpf_map_offload_update_elem(map, key, value, flags); 258 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || 259 map->map_type == BPF_MAP_TYPE_ARENA || 260 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 261 return map->ops->map_update_elem(map, key, value, flags); 262 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || 263 map->map_type == BPF_MAP_TYPE_SOCKMAP) { 264 return sock_map_update_elem_sys(map, key, value, flags); 265 } else if (IS_FD_PROG_ARRAY(map)) { 266 return bpf_fd_array_map_update_elem(map, map_file, key, value, 267 flags); 268 } 269 270 bpf_disable_instrumentation(); 271 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 272 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 273 err = bpf_percpu_hash_update(map, key, value, flags); 274 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 275 err = bpf_percpu_array_update(map, key, value, flags); 276 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 277 err = bpf_percpu_cgroup_storage_update(map, key, value, 278 flags); 279 } else if (IS_FD_ARRAY(map)) { 280 err = bpf_fd_array_map_update_elem(map, map_file, key, value, 281 flags); 282 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 283 err = bpf_fd_htab_map_update_elem(map, map_file, key, value, 284 flags); 285 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 286 /* rcu_read_lock() is not needed */ 287 err = bpf_fd_reuseport_array_update_elem(map, key, value, 288 flags); 289 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 290 map->map_type == BPF_MAP_TYPE_STACK || 291 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 292 err = map->ops->map_push_elem(map, value, flags); 293 } else { 294 err = bpf_obj_pin_uptrs(map->record, value); 295 if (!err) { 296 rcu_read_lock(); 297 err = map->ops->map_update_elem(map, key, value, flags); 298 rcu_read_unlock(); 299 if (err) 300 bpf_obj_unpin_uptrs(map->record, value); 301 } 302 } 303 bpf_enable_instrumentation(); 304 305 return err; 306 } 307 308 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, 309 __u64 flags) 310 { 311 void *ptr; 312 int err; 313 314 if (bpf_map_is_offloaded(map)) 315 return bpf_map_offload_lookup_elem(map, key, value); 316 317 bpf_disable_instrumentation(); 318 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 319 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 320 err = bpf_percpu_hash_copy(map, key, value, flags); 321 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 322 err = bpf_percpu_array_copy(map, key, value, flags); 323 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 324 err = bpf_percpu_cgroup_storage_copy(map, key, value, flags); 325 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 326 err = bpf_stackmap_extract(map, key, value, false); 327 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { 328 err = bpf_fd_array_map_lookup_elem(map, key, value); 329 } else if (IS_FD_HASH(map)) { 330 err = bpf_fd_htab_map_lookup_elem(map, key, value); 331 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 332 err = bpf_fd_reuseport_array_lookup_elem(map, key, value); 333 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 334 map->map_type == BPF_MAP_TYPE_STACK || 335 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 336 err = map->ops->map_peek_elem(map, value); 337 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 338 /* struct_ops map requires directly updating "value" */ 339 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value); 340 } else { 341 rcu_read_lock(); 342 if (map->ops->map_lookup_elem_sys_only) 343 ptr = map->ops->map_lookup_elem_sys_only(map, key); 344 else 345 ptr = map->ops->map_lookup_elem(map, key); 346 if (IS_ERR(ptr)) { 347 err = PTR_ERR(ptr); 348 } else if (!ptr) { 349 err = -ENOENT; 350 } else { 351 err = 0; 352 if (flags & BPF_F_LOCK) 353 /* lock 'ptr' and copy everything but lock */ 354 copy_map_value_locked(map, value, ptr, true); 355 else 356 copy_map_value(map, value, ptr); 357 /* mask lock and timer, since value wasn't zero inited */ 358 check_and_init_map_value(map, value); 359 } 360 rcu_read_unlock(); 361 } 362 363 bpf_enable_instrumentation(); 364 365 return err; 366 } 367 368 /* Please, do not use this function outside from the map creation path 369 * (e.g. in map update path) without taking care of setting the active 370 * memory cgroup (see at bpf_map_kmalloc_node() for example). 371 */ 372 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) 373 { 374 /* We really just want to fail instead of triggering OOM killer 375 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, 376 * which is used for lower order allocation requests. 377 * 378 * It has been observed that higher order allocation requests done by 379 * vmalloc with __GFP_NORETRY being set might fail due to not trying 380 * to reclaim memory from the page cache, thus we set 381 * __GFP_RETRY_MAYFAIL to avoid such situations. 382 */ 383 384 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO); 385 unsigned int flags = 0; 386 unsigned long align = 1; 387 void *area; 388 389 if (size >= SIZE_MAX) 390 return NULL; 391 392 /* kmalloc()'ed memory can't be mmap()'ed */ 393 if (mmapable) { 394 BUG_ON(!PAGE_ALIGNED(size)); 395 align = SHMLBA; 396 flags = VM_USERMAP; 397 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { 398 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, 399 numa_node); 400 if (area != NULL) 401 return area; 402 } 403 404 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 405 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, 406 flags, numa_node, __builtin_return_address(0)); 407 } 408 409 void *bpf_map_area_alloc(u64 size, int numa_node) 410 { 411 return __bpf_map_area_alloc(size, numa_node, false); 412 } 413 414 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) 415 { 416 return __bpf_map_area_alloc(size, numa_node, true); 417 } 418 419 void bpf_map_area_free(void *area) 420 { 421 kvfree(area); 422 } 423 424 static u32 bpf_map_flags_retain_permanent(u32 flags) 425 { 426 /* Some map creation flags are not tied to the map object but 427 * rather to the map fd instead, so they have no meaning upon 428 * map object inspection since multiple file descriptors with 429 * different (access) properties can exist here. Thus, given 430 * this has zero meaning for the map itself, lets clear these 431 * from here. 432 */ 433 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); 434 } 435 436 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) 437 { 438 map->map_type = attr->map_type; 439 map->key_size = attr->key_size; 440 map->value_size = attr->value_size; 441 map->max_entries = attr->max_entries; 442 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); 443 map->numa_node = bpf_map_attr_numa_node(attr); 444 map->map_extra = attr->map_extra; 445 } 446 447 static int bpf_map_alloc_id(struct bpf_map *map) 448 { 449 int id; 450 451 idr_preload(GFP_KERNEL); 452 spin_lock_bh(&map_idr_lock); 453 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); 454 if (id > 0) 455 map->id = id; 456 spin_unlock_bh(&map_idr_lock); 457 idr_preload_end(); 458 459 if (WARN_ON_ONCE(!id)) 460 return -ENOSPC; 461 462 return id > 0 ? 0 : id; 463 } 464 465 void bpf_map_free_id(struct bpf_map *map) 466 { 467 unsigned long flags; 468 469 /* Offloaded maps are removed from the IDR store when their device 470 * disappears - even if someone holds an fd to them they are unusable, 471 * the memory is gone, all ops will fail; they are simply waiting for 472 * refcnt to drop to be freed. 473 */ 474 if (!map->id) 475 return; 476 477 spin_lock_irqsave(&map_idr_lock, flags); 478 479 idr_remove(&map_idr, map->id); 480 map->id = 0; 481 482 spin_unlock_irqrestore(&map_idr_lock, flags); 483 } 484 485 #ifdef CONFIG_MEMCG 486 static void bpf_map_save_memcg(struct bpf_map *map) 487 { 488 /* Currently if a map is created by a process belonging to the root 489 * memory cgroup, get_obj_cgroup_from_current() will return NULL. 490 * So we have to check map->objcg for being NULL each time it's 491 * being used. 492 */ 493 if (memcg_bpf_enabled()) 494 map->objcg = get_obj_cgroup_from_current(); 495 } 496 497 static void bpf_map_release_memcg(struct bpf_map *map) 498 { 499 if (map->objcg) 500 obj_cgroup_put(map->objcg); 501 } 502 503 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) 504 { 505 if (map->objcg) 506 return get_mem_cgroup_from_objcg(map->objcg); 507 508 return root_mem_cgroup; 509 } 510 511 void bpf_map_memcg_enter(const struct bpf_map *map, struct mem_cgroup **old_memcg, 512 struct mem_cgroup **new_memcg) 513 { 514 *new_memcg = bpf_map_get_memcg(map); 515 *old_memcg = set_active_memcg(*new_memcg); 516 } 517 518 void bpf_map_memcg_exit(struct mem_cgroup *old_memcg, 519 struct mem_cgroup *new_memcg) 520 { 521 set_active_memcg(old_memcg); 522 mem_cgroup_put(new_memcg); 523 } 524 525 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, 526 int node) 527 { 528 struct mem_cgroup *memcg, *old_memcg; 529 void *ptr; 530 531 bpf_map_memcg_enter(map, &old_memcg, &memcg); 532 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); 533 bpf_map_memcg_exit(old_memcg, memcg); 534 535 return ptr; 536 } 537 538 void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags, 539 int node) 540 { 541 struct mem_cgroup *memcg, *old_memcg; 542 void *ptr; 543 544 bpf_map_memcg_enter(map, &old_memcg, &memcg); 545 ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node); 546 bpf_map_memcg_exit(old_memcg, memcg); 547 548 return ptr; 549 } 550 551 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) 552 { 553 struct mem_cgroup *memcg, *old_memcg; 554 void *ptr; 555 556 bpf_map_memcg_enter(map, &old_memcg, &memcg); 557 ptr = kzalloc(size, flags | __GFP_ACCOUNT); 558 bpf_map_memcg_exit(old_memcg, memcg); 559 560 return ptr; 561 } 562 563 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, 564 gfp_t flags) 565 { 566 struct mem_cgroup *memcg, *old_memcg; 567 void *ptr; 568 569 bpf_map_memcg_enter(map, &old_memcg, &memcg); 570 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); 571 bpf_map_memcg_exit(old_memcg, memcg); 572 573 return ptr; 574 } 575 576 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, 577 size_t align, gfp_t flags) 578 { 579 struct mem_cgroup *memcg, *old_memcg; 580 void __percpu *ptr; 581 582 bpf_map_memcg_enter(map, &old_memcg, &memcg); 583 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); 584 bpf_map_memcg_exit(old_memcg, memcg); 585 586 return ptr; 587 } 588 589 #else 590 static void bpf_map_save_memcg(struct bpf_map *map) 591 { 592 } 593 594 static void bpf_map_release_memcg(struct bpf_map *map) 595 { 596 } 597 #endif 598 599 static bool can_alloc_pages(void) 600 { 601 return preempt_count() == 0 && !irqs_disabled() && 602 !IS_ENABLED(CONFIG_PREEMPT_RT); 603 } 604 605 static struct page *__bpf_alloc_page(int nid) 606 { 607 if (!can_alloc_pages()) 608 return alloc_pages_nolock(__GFP_ACCOUNT, nid, 0); 609 610 return alloc_pages_node(nid, 611 GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT 612 | __GFP_NOWARN, 613 0); 614 } 615 616 int bpf_map_alloc_pages(const struct bpf_map *map, int nid, 617 unsigned long nr_pages, struct page **pages) 618 { 619 unsigned long i, j; 620 struct page *pg; 621 int ret = 0; 622 623 for (i = 0; i < nr_pages; i++) { 624 pg = __bpf_alloc_page(nid); 625 626 if (pg) { 627 pages[i] = pg; 628 continue; 629 } 630 for (j = 0; j < i; j++) 631 free_pages_nolock(pages[j], 0); 632 ret = -ENOMEM; 633 break; 634 } 635 636 return ret; 637 } 638 639 640 static int btf_field_cmp(const void *a, const void *b) 641 { 642 const struct btf_field *f1 = a, *f2 = b; 643 644 if (f1->offset < f2->offset) 645 return -1; 646 else if (f1->offset > f2->offset) 647 return 1; 648 return 0; 649 } 650 651 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 652 u32 field_mask) 653 { 654 struct btf_field *field; 655 656 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 657 return NULL; 658 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 659 if (!field || !(field->type & field_mask)) 660 return NULL; 661 return field; 662 } 663 664 void btf_record_free(struct btf_record *rec) 665 { 666 int i; 667 668 if (IS_ERR_OR_NULL(rec)) 669 return; 670 for (i = 0; i < rec->cnt; i++) { 671 switch (rec->fields[i].type) { 672 case BPF_KPTR_UNREF: 673 case BPF_KPTR_REF: 674 case BPF_KPTR_PERCPU: 675 case BPF_UPTR: 676 if (rec->fields[i].kptr.module) 677 module_put(rec->fields[i].kptr.module); 678 if (btf_is_kernel(rec->fields[i].kptr.btf)) 679 btf_put(rec->fields[i].kptr.btf); 680 break; 681 case BPF_LIST_HEAD: 682 case BPF_LIST_NODE: 683 case BPF_RB_ROOT: 684 case BPF_RB_NODE: 685 case BPF_SPIN_LOCK: 686 case BPF_RES_SPIN_LOCK: 687 case BPF_TIMER: 688 case BPF_REFCOUNT: 689 case BPF_WORKQUEUE: 690 case BPF_TASK_WORK: 691 /* Nothing to release */ 692 break; 693 default: 694 WARN_ON_ONCE(1); 695 continue; 696 } 697 } 698 kfree(rec); 699 } 700 701 void bpf_map_free_record(struct bpf_map *map) 702 { 703 btf_record_free(map->record); 704 map->record = NULL; 705 } 706 707 struct btf_record *btf_record_dup(const struct btf_record *rec) 708 { 709 const struct btf_field *fields; 710 struct btf_record *new_rec; 711 int ret, size, i; 712 713 if (IS_ERR_OR_NULL(rec)) 714 return NULL; 715 size = struct_size(rec, fields, rec->cnt); 716 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 717 if (!new_rec) 718 return ERR_PTR(-ENOMEM); 719 /* Do a deep copy of the btf_record */ 720 fields = rec->fields; 721 new_rec->cnt = 0; 722 for (i = 0; i < rec->cnt; i++) { 723 switch (fields[i].type) { 724 case BPF_KPTR_UNREF: 725 case BPF_KPTR_REF: 726 case BPF_KPTR_PERCPU: 727 case BPF_UPTR: 728 if (btf_is_kernel(fields[i].kptr.btf)) 729 btf_get(fields[i].kptr.btf); 730 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 731 ret = -ENXIO; 732 goto free; 733 } 734 break; 735 case BPF_LIST_HEAD: 736 case BPF_LIST_NODE: 737 case BPF_RB_ROOT: 738 case BPF_RB_NODE: 739 case BPF_SPIN_LOCK: 740 case BPF_RES_SPIN_LOCK: 741 case BPF_TIMER: 742 case BPF_REFCOUNT: 743 case BPF_WORKQUEUE: 744 case BPF_TASK_WORK: 745 /* Nothing to acquire */ 746 break; 747 default: 748 ret = -EFAULT; 749 WARN_ON_ONCE(1); 750 goto free; 751 } 752 new_rec->cnt++; 753 } 754 return new_rec; 755 free: 756 btf_record_free(new_rec); 757 return ERR_PTR(ret); 758 } 759 760 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 761 { 762 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 763 int size; 764 765 if (!a_has_fields && !b_has_fields) 766 return true; 767 if (a_has_fields != b_has_fields) 768 return false; 769 if (rec_a->cnt != rec_b->cnt) 770 return false; 771 size = struct_size(rec_a, fields, rec_a->cnt); 772 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 773 * members are zeroed out. So memcmp is safe to do without worrying 774 * about padding/unused fields. 775 * 776 * While spin_lock, timer, and kptr have no relation to map BTF, 777 * list_head metadata is specific to map BTF, the btf and value_rec 778 * members in particular. btf is the map BTF, while value_rec points to 779 * btf_record in that map BTF. 780 * 781 * So while by default, we don't rely on the map BTF (which the records 782 * were parsed from) matching for both records, which is not backwards 783 * compatible, in case list_head is part of it, we implicitly rely on 784 * that by way of depending on memcmp succeeding for it. 785 */ 786 return !memcmp(rec_a, rec_b, size); 787 } 788 789 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 790 { 791 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 792 return; 793 bpf_timer_cancel_and_free(obj + rec->timer_off); 794 } 795 796 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj) 797 { 798 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE))) 799 return; 800 bpf_wq_cancel_and_free(obj + rec->wq_off); 801 } 802 803 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj) 804 { 805 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK))) 806 return; 807 bpf_task_work_cancel_and_free(obj + rec->task_work_off); 808 } 809 810 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 811 { 812 const struct btf_field *fields; 813 int i; 814 815 if (IS_ERR_OR_NULL(rec)) 816 return; 817 fields = rec->fields; 818 for (i = 0; i < rec->cnt; i++) { 819 struct btf_struct_meta *pointee_struct_meta; 820 const struct btf_field *field = &fields[i]; 821 void *field_ptr = obj + field->offset; 822 void *xchgd_field; 823 824 switch (fields[i].type) { 825 case BPF_SPIN_LOCK: 826 case BPF_RES_SPIN_LOCK: 827 break; 828 case BPF_TIMER: 829 bpf_timer_cancel_and_free(field_ptr); 830 break; 831 case BPF_WORKQUEUE: 832 bpf_wq_cancel_and_free(field_ptr); 833 break; 834 case BPF_TASK_WORK: 835 bpf_task_work_cancel_and_free(field_ptr); 836 break; 837 case BPF_KPTR_UNREF: 838 WRITE_ONCE(*(u64 *)field_ptr, 0); 839 break; 840 case BPF_KPTR_REF: 841 case BPF_KPTR_PERCPU: 842 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); 843 if (!xchgd_field) 844 break; 845 846 if (!btf_is_kernel(field->kptr.btf)) { 847 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, 848 field->kptr.btf_id); 849 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? 850 pointee_struct_meta->record : NULL, 851 fields[i].type == BPF_KPTR_PERCPU); 852 } else { 853 field->kptr.dtor(xchgd_field); 854 } 855 break; 856 case BPF_UPTR: 857 /* The caller ensured that no one is using the uptr */ 858 unpin_uptr_kaddr(*(void **)field_ptr); 859 break; 860 case BPF_LIST_HEAD: 861 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 862 continue; 863 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 864 break; 865 case BPF_RB_ROOT: 866 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 867 continue; 868 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); 869 break; 870 case BPF_LIST_NODE: 871 case BPF_RB_NODE: 872 case BPF_REFCOUNT: 873 break; 874 default: 875 WARN_ON_ONCE(1); 876 continue; 877 } 878 } 879 } 880 881 static void bpf_map_free(struct bpf_map *map) 882 { 883 struct btf_record *rec = map->record; 884 struct btf *btf = map->btf; 885 886 /* implementation dependent freeing. Disabling migration to simplify 887 * the free of values or special fields allocated from bpf memory 888 * allocator. 889 */ 890 kfree(map->excl_prog_sha); 891 migrate_disable(); 892 map->ops->map_free(map); 893 migrate_enable(); 894 895 /* Delay freeing of btf_record for maps, as map_free 896 * callback usually needs access to them. It is better to do it here 897 * than require each callback to do the free itself manually. 898 * 899 * Note that the btf_record stashed in map->inner_map_meta->record was 900 * already freed using the map_free callback for map in map case which 901 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 902 * template bpf_map struct used during verification. 903 */ 904 btf_record_free(rec); 905 /* Delay freeing of btf for maps, as map_free callback may need 906 * struct_meta info which will be freed with btf_put(). 907 */ 908 btf_put(btf); 909 } 910 911 /* called from workqueue */ 912 static void bpf_map_free_deferred(struct work_struct *work) 913 { 914 struct bpf_map *map = container_of(work, struct bpf_map, work); 915 916 security_bpf_map_free(map); 917 bpf_map_release_memcg(map); 918 bpf_map_owner_free(map); 919 bpf_map_free(map); 920 } 921 922 static void bpf_map_put_uref(struct bpf_map *map) 923 { 924 if (atomic64_dec_and_test(&map->usercnt)) { 925 if (map->ops->map_release_uref) 926 map->ops->map_release_uref(map); 927 } 928 } 929 930 static void bpf_map_free_in_work(struct bpf_map *map) 931 { 932 INIT_WORK(&map->work, bpf_map_free_deferred); 933 /* Avoid spawning kworkers, since they all might contend 934 * for the same mutex like slab_mutex. 935 */ 936 queue_work(system_dfl_wq, &map->work); 937 } 938 939 static void bpf_map_free_rcu_gp(struct rcu_head *rcu) 940 { 941 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); 942 } 943 944 /* decrement map refcnt and schedule it for freeing via workqueue 945 * (underlying map implementation ops->map_free() might sleep) 946 */ 947 void bpf_map_put(struct bpf_map *map) 948 { 949 if (atomic64_dec_and_test(&map->refcnt)) { 950 /* bpf_map_free_id() must be called first */ 951 bpf_map_free_id(map); 952 953 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); 954 /* RCU tasks trace grace period implies RCU grace period. */ 955 if (READ_ONCE(map->free_after_mult_rcu_gp)) 956 call_rcu_tasks_trace(&map->rcu, bpf_map_free_rcu_gp); 957 else if (READ_ONCE(map->free_after_rcu_gp)) 958 call_rcu(&map->rcu, bpf_map_free_rcu_gp); 959 else 960 bpf_map_free_in_work(map); 961 } 962 } 963 EXPORT_SYMBOL_GPL(bpf_map_put); 964 965 void bpf_map_put_with_uref(struct bpf_map *map) 966 { 967 bpf_map_put_uref(map); 968 bpf_map_put(map); 969 } 970 971 static int bpf_map_release(struct inode *inode, struct file *filp) 972 { 973 struct bpf_map *map = filp->private_data; 974 975 if (map->ops->map_release) 976 map->ops->map_release(map, filp); 977 978 bpf_map_put_with_uref(map); 979 return 0; 980 } 981 982 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 983 { 984 fmode_t mode = fd_file(f)->f_mode; 985 986 /* Our file permissions may have been overridden by global 987 * map permissions facing syscall side. 988 */ 989 if (READ_ONCE(map->frozen)) 990 mode &= ~FMODE_CAN_WRITE; 991 return mode; 992 } 993 994 #ifdef CONFIG_PROC_FS 995 /* Show the memory usage of a bpf map */ 996 static u64 bpf_map_memory_usage(const struct bpf_map *map) 997 { 998 return map->ops->map_mem_usage(map); 999 } 1000 1001 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 1002 { 1003 struct bpf_map *map = filp->private_data; 1004 u32 type = 0, jited = 0; 1005 1006 spin_lock(&map->owner_lock); 1007 if (map->owner) { 1008 type = map->owner->type; 1009 jited = map->owner->jited; 1010 } 1011 spin_unlock(&map->owner_lock); 1012 1013 seq_printf(m, 1014 "map_type:\t%u\n" 1015 "key_size:\t%u\n" 1016 "value_size:\t%u\n" 1017 "max_entries:\t%u\n" 1018 "map_flags:\t%#x\n" 1019 "map_extra:\t%#llx\n" 1020 "memlock:\t%llu\n" 1021 "map_id:\t%u\n" 1022 "frozen:\t%u\n", 1023 map->map_type, 1024 map->key_size, 1025 map->value_size, 1026 map->max_entries, 1027 map->map_flags, 1028 (unsigned long long)map->map_extra, 1029 bpf_map_memory_usage(map), 1030 map->id, 1031 READ_ONCE(map->frozen)); 1032 if (type) { 1033 seq_printf(m, "owner_prog_type:\t%u\n", type); 1034 seq_printf(m, "owner_jited:\t%u\n", jited); 1035 } 1036 } 1037 #endif 1038 1039 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 1040 loff_t *ppos) 1041 { 1042 /* We need this handler such that alloc_file() enables 1043 * f_mode with FMODE_CAN_READ. 1044 */ 1045 return -EINVAL; 1046 } 1047 1048 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 1049 size_t siz, loff_t *ppos) 1050 { 1051 /* We need this handler such that alloc_file() enables 1052 * f_mode with FMODE_CAN_WRITE. 1053 */ 1054 return -EINVAL; 1055 } 1056 1057 /* called for any extra memory-mapped regions (except initial) */ 1058 static void bpf_map_mmap_open(struct vm_area_struct *vma) 1059 { 1060 struct bpf_map *map = vma->vm_file->private_data; 1061 1062 if (vma->vm_flags & VM_MAYWRITE) 1063 bpf_map_write_active_inc(map); 1064 } 1065 1066 /* called for all unmapped memory region (including initial) */ 1067 static void bpf_map_mmap_close(struct vm_area_struct *vma) 1068 { 1069 struct bpf_map *map = vma->vm_file->private_data; 1070 1071 if (vma->vm_flags & VM_MAYWRITE) 1072 bpf_map_write_active_dec(map); 1073 } 1074 1075 static const struct vm_operations_struct bpf_map_default_vmops = { 1076 .open = bpf_map_mmap_open, 1077 .close = bpf_map_mmap_close, 1078 }; 1079 1080 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 1081 { 1082 struct bpf_map *map = filp->private_data; 1083 int err = 0; 1084 1085 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 1086 return -ENOTSUPP; 1087 1088 if (!(vma->vm_flags & VM_SHARED)) 1089 return -EINVAL; 1090 1091 mutex_lock(&map->freeze_mutex); 1092 1093 if (vma->vm_flags & VM_WRITE) { 1094 if (map->frozen) { 1095 err = -EPERM; 1096 goto out; 1097 } 1098 /* map is meant to be read-only, so do not allow mapping as 1099 * writable, because it's possible to leak a writable page 1100 * reference and allows user-space to still modify it after 1101 * freezing, while verifier will assume contents do not change 1102 */ 1103 if (map->map_flags & BPF_F_RDONLY_PROG) { 1104 err = -EACCES; 1105 goto out; 1106 } 1107 bpf_map_write_active_inc(map); 1108 } 1109 out: 1110 mutex_unlock(&map->freeze_mutex); 1111 if (err) 1112 return err; 1113 1114 /* set default open/close callbacks */ 1115 vma->vm_ops = &bpf_map_default_vmops; 1116 vma->vm_private_data = map; 1117 vm_flags_clear(vma, VM_MAYEXEC); 1118 /* If mapping is read-only, then disallow potentially re-mapping with 1119 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing 1120 * means that as far as BPF map's memory-mapped VMAs are concerned, 1121 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set, 1122 * both should be set, so we can forget about VM_MAYWRITE and always 1123 * check just VM_WRITE 1124 */ 1125 if (!(vma->vm_flags & VM_WRITE)) 1126 vm_flags_clear(vma, VM_MAYWRITE); 1127 1128 err = map->ops->map_mmap(map, vma); 1129 if (err) { 1130 if (vma->vm_flags & VM_WRITE) 1131 bpf_map_write_active_dec(map); 1132 } 1133 1134 return err; 1135 } 1136 1137 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 1138 { 1139 struct bpf_map *map = filp->private_data; 1140 1141 if (map->ops->map_poll) 1142 return map->ops->map_poll(map, filp, pts); 1143 1144 return EPOLLERR; 1145 } 1146 1147 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr, 1148 unsigned long len, unsigned long pgoff, 1149 unsigned long flags) 1150 { 1151 struct bpf_map *map = filp->private_data; 1152 1153 if (map->ops->map_get_unmapped_area) 1154 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); 1155 #ifdef CONFIG_MMU 1156 return mm_get_unmapped_area(filp, addr, len, pgoff, flags); 1157 #else 1158 return addr; 1159 #endif 1160 } 1161 1162 const struct file_operations bpf_map_fops = { 1163 #ifdef CONFIG_PROC_FS 1164 .show_fdinfo = bpf_map_show_fdinfo, 1165 #endif 1166 .release = bpf_map_release, 1167 .read = bpf_dummy_read, 1168 .write = bpf_dummy_write, 1169 .mmap = bpf_map_mmap, 1170 .poll = bpf_map_poll, 1171 .get_unmapped_area = bpf_get_unmapped_area, 1172 }; 1173 1174 int bpf_map_new_fd(struct bpf_map *map, int flags) 1175 { 1176 int ret; 1177 1178 ret = security_bpf_map(map, OPEN_FMODE(flags)); 1179 if (ret < 0) 1180 return ret; 1181 1182 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 1183 flags | O_CLOEXEC); 1184 } 1185 1186 int bpf_get_file_flag(int flags) 1187 { 1188 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 1189 return -EINVAL; 1190 if (flags & BPF_F_RDONLY) 1191 return O_RDONLY; 1192 if (flags & BPF_F_WRONLY) 1193 return O_WRONLY; 1194 return O_RDWR; 1195 } 1196 1197 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 1198 #define CHECK_ATTR(CMD) \ 1199 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 1200 sizeof(attr->CMD##_LAST_FIELD), 0, \ 1201 sizeof(*attr) - \ 1202 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 1203 sizeof(attr->CMD##_LAST_FIELD)) != NULL 1204 1205 /* dst and src must have at least "size" number of bytes. 1206 * Return strlen on success and < 0 on error. 1207 */ 1208 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 1209 { 1210 const char *end = src + size; 1211 const char *orig_src = src; 1212 1213 memset(dst, 0, size); 1214 /* Copy all isalnum(), '_' and '.' chars. */ 1215 while (src < end && *src) { 1216 if (!isalnum(*src) && 1217 *src != '_' && *src != '.') 1218 return -EINVAL; 1219 *dst++ = *src++; 1220 } 1221 1222 /* No '\0' found in "size" number of bytes */ 1223 if (src == end) 1224 return -EINVAL; 1225 1226 return src - orig_src; 1227 } 1228 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy); 1229 1230 int map_check_no_btf(struct bpf_map *map, 1231 const struct btf *btf, 1232 const struct btf_type *key_type, 1233 const struct btf_type *value_type) 1234 { 1235 return -ENOTSUPP; 1236 } 1237 1238 static int map_check_btf(struct bpf_map *map, struct bpf_token *token, 1239 const struct btf *btf, u32 btf_key_id, u32 btf_value_id) 1240 { 1241 const struct btf_type *key_type, *value_type; 1242 u32 key_size, value_size; 1243 int ret = 0; 1244 1245 /* Some maps allow key to be unspecified. */ 1246 if (btf_key_id) { 1247 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 1248 if (!key_type || key_size != map->key_size) 1249 return -EINVAL; 1250 } else { 1251 key_type = btf_type_by_id(btf, 0); 1252 if (!map->ops->map_check_btf) 1253 return -EINVAL; 1254 } 1255 1256 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1257 if (!value_type || value_size != map->value_size) 1258 return -EINVAL; 1259 1260 map->record = btf_parse_fields(btf, value_type, 1261 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1262 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR | 1263 BPF_TASK_WORK, 1264 map->value_size); 1265 if (!IS_ERR_OR_NULL(map->record)) { 1266 int i; 1267 1268 if (!bpf_token_capable(token, CAP_BPF)) { 1269 ret = -EPERM; 1270 goto free_map_tab; 1271 } 1272 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1273 ret = -EACCES; 1274 goto free_map_tab; 1275 } 1276 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1277 switch (map->record->field_mask & (1 << i)) { 1278 case 0: 1279 continue; 1280 case BPF_SPIN_LOCK: 1281 case BPF_RES_SPIN_LOCK: 1282 if (map->map_type != BPF_MAP_TYPE_HASH && 1283 map->map_type != BPF_MAP_TYPE_ARRAY && 1284 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1285 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1286 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1287 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1288 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1289 ret = -EOPNOTSUPP; 1290 goto free_map_tab; 1291 } 1292 break; 1293 case BPF_TIMER: 1294 case BPF_WORKQUEUE: 1295 case BPF_TASK_WORK: 1296 if (map->map_type != BPF_MAP_TYPE_HASH && 1297 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1298 map->map_type != BPF_MAP_TYPE_ARRAY) { 1299 ret = -EOPNOTSUPP; 1300 goto free_map_tab; 1301 } 1302 break; 1303 case BPF_KPTR_UNREF: 1304 case BPF_KPTR_REF: 1305 case BPF_KPTR_PERCPU: 1306 case BPF_REFCOUNT: 1307 if (map->map_type != BPF_MAP_TYPE_HASH && 1308 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1309 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1310 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1311 map->map_type != BPF_MAP_TYPE_ARRAY && 1312 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1313 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1314 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1315 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1316 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1317 ret = -EOPNOTSUPP; 1318 goto free_map_tab; 1319 } 1320 break; 1321 case BPF_UPTR: 1322 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { 1323 ret = -EOPNOTSUPP; 1324 goto free_map_tab; 1325 } 1326 break; 1327 case BPF_LIST_HEAD: 1328 case BPF_RB_ROOT: 1329 if (map->map_type != BPF_MAP_TYPE_HASH && 1330 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1331 map->map_type != BPF_MAP_TYPE_ARRAY) { 1332 ret = -EOPNOTSUPP; 1333 goto free_map_tab; 1334 } 1335 break; 1336 default: 1337 /* Fail if map_type checks are missing for a field type */ 1338 ret = -EOPNOTSUPP; 1339 goto free_map_tab; 1340 } 1341 } 1342 } 1343 1344 ret = btf_check_and_fixup_fields(btf, map->record); 1345 if (ret < 0) 1346 goto free_map_tab; 1347 1348 if (map->ops->map_check_btf) { 1349 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1350 if (ret < 0) 1351 goto free_map_tab; 1352 } 1353 1354 return ret; 1355 free_map_tab: 1356 bpf_map_free_record(map); 1357 return ret; 1358 } 1359 1360 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size 1361 /* called via syscall */ 1362 static int map_create_alloc(union bpf_attr *attr, bpfptr_t uattr, struct bpf_verifier_log *log, 1363 struct bpf_map **mapp, struct bpf_token **tokenp) 1364 { 1365 const struct bpf_map_ops *ops; 1366 struct bpf_token *token = NULL; 1367 int numa_node = bpf_map_attr_numa_node(attr); 1368 u32 map_type = attr->map_type; 1369 struct bpf_map *map; 1370 bool token_flag; 1371 int err; 1372 1373 err = CHECK_ATTR(BPF_MAP_CREATE); 1374 if (err) { 1375 bpf_log(log, "Invalid attr.\n"); 1376 return -EINVAL; 1377 } 1378 1379 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it 1380 * to avoid per-map type checks tripping on unknown flag 1381 */ 1382 token_flag = attr->map_flags & BPF_F_TOKEN_FD; 1383 attr->map_flags &= ~BPF_F_TOKEN_FD; 1384 1385 if (attr->btf_vmlinux_value_type_id) { 1386 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 1387 bpf_log(log, "btf_vmlinux_value_type_id can only be used with struct_ops maps.\n"); 1388 return -EINVAL; 1389 } 1390 if (attr->btf_key_type_id || attr->btf_value_type_id) { 1391 bpf_log(log, "btf_vmlinux_value_type_id is mutually exclusive with btf_key_type_id and btf_value_type_id.\n"); 1392 return -EINVAL; 1393 } 1394 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1395 bpf_log(log, "Invalid btf_value_type_id.\n"); 1396 return -EINVAL; 1397 } 1398 1399 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1400 attr->map_type != BPF_MAP_TYPE_ARENA && 1401 attr->map_extra != 0) { 1402 bpf_log(log, "Invalid map_extra.\n"); 1403 return -EINVAL; 1404 } 1405 1406 if (numa_node != NUMA_NO_NODE && 1407 ((unsigned int)numa_node >= nr_node_ids || 1408 !node_online(numa_node))) { 1409 bpf_log(log, "Invalid numa_node.\n"); 1410 return -EINVAL; 1411 } 1412 1413 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1414 map_type = attr->map_type; 1415 if (map_type >= ARRAY_SIZE(bpf_map_types)) { 1416 bpf_log(log, "Invalid map_type.\n"); 1417 return -EINVAL; 1418 } 1419 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1420 ops = bpf_map_types[map_type]; 1421 if (!ops) 1422 return -EINVAL; 1423 1424 if (ops->map_alloc_check) { 1425 err = ops->map_alloc_check(attr); 1426 if (err) 1427 return err; 1428 } 1429 if (attr->map_ifindex) 1430 ops = &bpf_map_offload_ops; 1431 if (!ops->map_mem_usage) 1432 return -EINVAL; 1433 1434 if (token_flag) { 1435 token = bpf_token_get_from_fd(attr->map_token_fd); 1436 if (IS_ERR(token)) { 1437 bpf_log(log, "Invalid map_token_fd.\n"); 1438 return PTR_ERR(token); 1439 } 1440 1441 /* if current token doesn't grant map creation permissions, 1442 * then we can't use this token, so ignore it and rely on 1443 * system-wide capabilities checks 1444 */ 1445 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || 1446 !bpf_token_allow_map_type(token, attr->map_type)) { 1447 bpf_token_put(token); 1448 token = NULL; 1449 } 1450 } 1451 1452 err = -EPERM; 1453 1454 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1455 * creation for unprivileged users; other actions depend 1456 * on fd availability and access to bpffs, so are dependent on 1457 * object creation success. Even with unprivileged BPF disabled, 1458 * capability checks are still carried out. 1459 */ 1460 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) 1461 goto put_token; 1462 1463 /* check privileged map type permissions */ 1464 switch (map_type) { 1465 case BPF_MAP_TYPE_ARRAY: 1466 case BPF_MAP_TYPE_PERCPU_ARRAY: 1467 case BPF_MAP_TYPE_PROG_ARRAY: 1468 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1469 case BPF_MAP_TYPE_CGROUP_ARRAY: 1470 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1471 case BPF_MAP_TYPE_HASH: 1472 case BPF_MAP_TYPE_PERCPU_HASH: 1473 case BPF_MAP_TYPE_HASH_OF_MAPS: 1474 case BPF_MAP_TYPE_RINGBUF: 1475 case BPF_MAP_TYPE_USER_RINGBUF: 1476 case BPF_MAP_TYPE_CGROUP_STORAGE: 1477 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1478 /* unprivileged */ 1479 break; 1480 case BPF_MAP_TYPE_SK_STORAGE: 1481 case BPF_MAP_TYPE_INODE_STORAGE: 1482 case BPF_MAP_TYPE_TASK_STORAGE: 1483 case BPF_MAP_TYPE_CGRP_STORAGE: 1484 case BPF_MAP_TYPE_BLOOM_FILTER: 1485 case BPF_MAP_TYPE_LPM_TRIE: 1486 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1487 case BPF_MAP_TYPE_STACK_TRACE: 1488 case BPF_MAP_TYPE_QUEUE: 1489 case BPF_MAP_TYPE_STACK: 1490 case BPF_MAP_TYPE_LRU_HASH: 1491 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1492 case BPF_MAP_TYPE_STRUCT_OPS: 1493 case BPF_MAP_TYPE_CPUMAP: 1494 case BPF_MAP_TYPE_ARENA: 1495 case BPF_MAP_TYPE_INSN_ARRAY: 1496 if (!bpf_token_capable(token, CAP_BPF)) 1497 goto put_token; 1498 break; 1499 case BPF_MAP_TYPE_SOCKMAP: 1500 case BPF_MAP_TYPE_SOCKHASH: 1501 case BPF_MAP_TYPE_DEVMAP: 1502 case BPF_MAP_TYPE_DEVMAP_HASH: 1503 case BPF_MAP_TYPE_XSKMAP: 1504 if (!bpf_token_capable(token, CAP_NET_ADMIN)) 1505 goto put_token; 1506 break; 1507 default: 1508 WARN(1, "unsupported map type %d", map_type); 1509 goto put_token; 1510 } 1511 1512 map = ops->map_alloc(attr); 1513 if (IS_ERR(map)) { 1514 err = PTR_ERR(map); 1515 goto put_token; 1516 } 1517 map->ops = ops; 1518 map->map_type = map_type; 1519 1520 err = bpf_obj_name_cpy(map->name, attr->map_name, 1521 sizeof(attr->map_name)); 1522 if (err < 0) { 1523 bpf_log(log, "Invalid map_name.\n"); 1524 goto free_map; 1525 } 1526 1527 preempt_disable(); 1528 map->cookie = gen_cookie_next(&bpf_map_cookie); 1529 preempt_enable(); 1530 1531 atomic64_set(&map->refcnt, 1); 1532 atomic64_set(&map->usercnt, 1); 1533 mutex_init(&map->freeze_mutex); 1534 spin_lock_init(&map->owner_lock); 1535 1536 if (attr->btf_key_type_id || attr->btf_value_type_id || 1537 /* Even the map's value is a kernel's struct, 1538 * the bpf_prog.o must have BTF to begin with 1539 * to figure out the corresponding kernel's 1540 * counter part. Thus, attr->btf_fd has 1541 * to be valid also. 1542 */ 1543 attr->btf_vmlinux_value_type_id) { 1544 struct btf *btf; 1545 1546 btf = btf_get_by_fd(attr->btf_fd); 1547 if (IS_ERR(btf)) { 1548 bpf_log(log, "Invalid btf_fd.\n"); 1549 err = PTR_ERR(btf); 1550 goto free_map; 1551 } 1552 if (btf_is_kernel(btf)) { 1553 btf_put(btf); 1554 err = -EACCES; 1555 goto free_map; 1556 } 1557 map->btf = btf; 1558 1559 if (attr->btf_value_type_id) { 1560 err = map_check_btf(map, token, btf, attr->btf_key_type_id, 1561 attr->btf_value_type_id); 1562 if (err) 1563 goto free_map; 1564 } 1565 1566 map->btf_key_type_id = attr->btf_key_type_id; 1567 map->btf_value_type_id = attr->btf_value_type_id; 1568 map->btf_vmlinux_value_type_id = 1569 attr->btf_vmlinux_value_type_id; 1570 } 1571 1572 if (attr->excl_prog_hash) { 1573 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); 1574 1575 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { 1576 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1577 err = -EINVAL; 1578 goto free_map; 1579 } 1580 1581 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); 1582 if (!map->excl_prog_sha) { 1583 err = -ENOMEM; 1584 goto free_map; 1585 } 1586 1587 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) { 1588 err = -EFAULT; 1589 goto free_map; 1590 } 1591 1592 /* See libbpf: emit_signature_match() */ 1593 BUILD_BUG_ON(offsetof(struct bpf_map, excl) != SHA256_DIGEST_SIZE); 1594 BUILD_BUG_ON(!__same_type(map->excl, u32)); 1595 BUILD_BUG_ON(offsetof(struct bpf_map, sha) != 0); 1596 BUILD_BUG_ON(!__same_type(map->sha, u8[SHA256_DIGEST_SIZE])); 1597 map->excl = 1; 1598 } else if (attr->excl_prog_hash_size) { 1599 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1600 err = -EINVAL; 1601 goto free_map; 1602 } 1603 1604 *mapp = map; 1605 *tokenp = token; 1606 return 0; 1607 1608 free_map: 1609 bpf_map_free(map); 1610 put_token: 1611 bpf_token_put(token); 1612 return err; 1613 } 1614 1615 static int map_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common, 1616 bpfptr_t uattr_common, u32 size_common) 1617 { 1618 struct bpf_token *token = NULL; 1619 struct bpf_verifier_log *log; 1620 struct bpf_log_attr attr_log; 1621 struct bpf_map *map = NULL; 1622 int err, ret; 1623 int f_flags; 1624 1625 log = bpf_log_attr_create_vlog(&attr_log, attr_common, uattr_common, size_common); 1626 if (IS_ERR(log)) 1627 return PTR_ERR(log); 1628 1629 err = map_create_alloc(attr, uattr, log, &map, &token); 1630 1631 /* preserve original error even if log finalization is successful */ 1632 ret = bpf_log_attr_finalize(&attr_log, log); 1633 if (ret) 1634 err = ret; 1635 1636 kfree(log); 1637 1638 if (err) 1639 goto free_map; 1640 1641 f_flags = bpf_get_file_flag(attr->map_flags); 1642 if (f_flags < 0) { 1643 err = f_flags; 1644 goto free_map; 1645 } 1646 1647 err = security_bpf_map_create(map, attr, token, uattr.is_kernel); 1648 if (err) 1649 goto free_map_sec; 1650 1651 err = bpf_map_alloc_id(map); 1652 if (err) 1653 goto free_map_sec; 1654 1655 bpf_map_save_memcg(map); 1656 bpf_token_put(token); 1657 1658 err = bpf_map_new_fd(map, f_flags); 1659 if (err < 0) { 1660 /* failed to allocate fd. 1661 * bpf_map_put_with_uref() is needed because the above 1662 * bpf_map_alloc_id() has published the map 1663 * to the userspace and the userspace may 1664 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1665 */ 1666 bpf_map_put_with_uref(map); 1667 return err; 1668 } 1669 1670 return err; 1671 1672 free_map_sec: 1673 security_bpf_map_free(map); 1674 free_map: 1675 if (map) 1676 bpf_map_free(map); 1677 bpf_token_put(token); 1678 return err; 1679 } 1680 1681 void bpf_map_inc(struct bpf_map *map) 1682 { 1683 atomic64_inc(&map->refcnt); 1684 } 1685 EXPORT_SYMBOL_GPL(bpf_map_inc); 1686 1687 void bpf_map_inc_with_uref(struct bpf_map *map) 1688 { 1689 atomic64_inc(&map->refcnt); 1690 atomic64_inc(&map->usercnt); 1691 } 1692 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1693 1694 struct bpf_map *bpf_map_get(u32 ufd) 1695 { 1696 CLASS(fd, f)(ufd); 1697 struct bpf_map *map = __bpf_map_get(f); 1698 1699 if (!IS_ERR(map)) 1700 bpf_map_inc(map); 1701 1702 return map; 1703 } 1704 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); 1705 1706 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1707 { 1708 CLASS(fd, f)(ufd); 1709 struct bpf_map *map = __bpf_map_get(f); 1710 1711 if (!IS_ERR(map)) 1712 bpf_map_inc_with_uref(map); 1713 1714 return map; 1715 } 1716 1717 /* map_idr_lock should have been held or the map should have been 1718 * protected by rcu read lock. 1719 */ 1720 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1721 { 1722 int refold; 1723 1724 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1725 if (!refold) 1726 return ERR_PTR(-ENOENT); 1727 if (uref) 1728 atomic64_inc(&map->usercnt); 1729 1730 return map; 1731 } 1732 1733 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1734 { 1735 lockdep_assert(rcu_read_lock_held()); 1736 return __bpf_map_inc_not_zero(map, false); 1737 } 1738 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1739 1740 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value, 1741 bool delete) 1742 { 1743 return -ENOTSUPP; 1744 } 1745 1746 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1747 { 1748 if (key_size) 1749 return vmemdup_user(ukey, key_size); 1750 1751 if (ukey) 1752 return ERR_PTR(-EINVAL); 1753 1754 return NULL; 1755 } 1756 1757 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1758 { 1759 if (key_size) 1760 return kvmemdup_bpfptr(ukey, key_size); 1761 1762 if (!bpfptr_is_null(ukey)) 1763 return ERR_PTR(-EINVAL); 1764 1765 return NULL; 1766 } 1767 1768 /* last field in 'union bpf_attr' used by this command */ 1769 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1770 1771 static int map_lookup_elem(union bpf_attr *attr) 1772 { 1773 void __user *ukey = u64_to_user_ptr(attr->key); 1774 void __user *uvalue = u64_to_user_ptr(attr->value); 1775 struct bpf_map *map; 1776 void *key, *value; 1777 u32 value_size; 1778 int err; 1779 1780 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1781 return -EINVAL; 1782 1783 CLASS(fd, f)(attr->map_fd); 1784 map = __bpf_map_get(f); 1785 if (IS_ERR(map)) 1786 return PTR_ERR(map); 1787 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1788 return -EPERM; 1789 1790 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU); 1791 if (err) 1792 return err; 1793 1794 key = __bpf_copy_key(ukey, map->key_size); 1795 if (IS_ERR(key)) 1796 return PTR_ERR(key); 1797 1798 value_size = bpf_map_value_size(map, attr->flags); 1799 1800 err = -ENOMEM; 1801 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1802 if (!value) 1803 goto free_key; 1804 1805 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1806 if (copy_from_user(value, uvalue, value_size)) 1807 err = -EFAULT; 1808 else 1809 err = bpf_map_copy_value(map, key, value, attr->flags); 1810 goto free_value; 1811 } 1812 1813 err = bpf_map_copy_value(map, key, value, attr->flags); 1814 if (err) 1815 goto free_value; 1816 1817 err = -EFAULT; 1818 if (copy_to_user(uvalue, value, value_size) != 0) 1819 goto free_value; 1820 1821 err = 0; 1822 1823 free_value: 1824 kvfree(value); 1825 free_key: 1826 kvfree(key); 1827 return err; 1828 } 1829 1830 1831 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1832 1833 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1834 { 1835 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1836 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1837 struct bpf_map *map; 1838 void *key, *value; 1839 u32 value_size; 1840 int err; 1841 1842 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1843 return -EINVAL; 1844 1845 CLASS(fd, f)(attr->map_fd); 1846 map = __bpf_map_get(f); 1847 if (IS_ERR(map)) 1848 return PTR_ERR(map); 1849 bpf_map_write_active_inc(map); 1850 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1851 err = -EPERM; 1852 goto err_put; 1853 } 1854 1855 err = bpf_map_check_op_flags(map, attr->flags, ~0); 1856 if (err) 1857 goto err_put; 1858 1859 key = ___bpf_copy_key(ukey, map->key_size); 1860 if (IS_ERR(key)) { 1861 err = PTR_ERR(key); 1862 goto err_put; 1863 } 1864 1865 value_size = bpf_map_value_size(map, attr->flags); 1866 value = kvmemdup_bpfptr(uvalue, value_size); 1867 if (IS_ERR(value)) { 1868 err = PTR_ERR(value); 1869 goto free_key; 1870 } 1871 1872 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); 1873 if (!err) 1874 maybe_wait_bpf_programs(map); 1875 1876 kvfree(value); 1877 free_key: 1878 kvfree(key); 1879 err_put: 1880 bpf_map_write_active_dec(map); 1881 return err; 1882 } 1883 1884 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1885 1886 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1887 { 1888 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1889 struct bpf_map *map; 1890 void *key; 1891 int err; 1892 1893 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1894 return -EINVAL; 1895 1896 CLASS(fd, f)(attr->map_fd); 1897 map = __bpf_map_get(f); 1898 if (IS_ERR(map)) 1899 return PTR_ERR(map); 1900 bpf_map_write_active_inc(map); 1901 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1902 err = -EPERM; 1903 goto err_put; 1904 } 1905 1906 key = ___bpf_copy_key(ukey, map->key_size); 1907 if (IS_ERR(key)) { 1908 err = PTR_ERR(key); 1909 goto err_put; 1910 } 1911 1912 if (bpf_map_is_offloaded(map)) { 1913 err = bpf_map_offload_delete_elem(map, key); 1914 goto out; 1915 } else if (IS_FD_PROG_ARRAY(map) || 1916 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1917 /* These maps require sleepable context */ 1918 err = map->ops->map_delete_elem(map, key); 1919 goto out; 1920 } 1921 1922 bpf_disable_instrumentation(); 1923 rcu_read_lock(); 1924 err = map->ops->map_delete_elem(map, key); 1925 rcu_read_unlock(); 1926 bpf_enable_instrumentation(); 1927 if (!err) 1928 maybe_wait_bpf_programs(map); 1929 out: 1930 kvfree(key); 1931 err_put: 1932 bpf_map_write_active_dec(map); 1933 return err; 1934 } 1935 1936 /* last field in 'union bpf_attr' used by this command */ 1937 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1938 1939 static int map_get_next_key(union bpf_attr *attr) 1940 { 1941 void __user *ukey = u64_to_user_ptr(attr->key); 1942 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1943 struct bpf_map *map; 1944 void *key, *next_key; 1945 int err; 1946 1947 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1948 return -EINVAL; 1949 1950 CLASS(fd, f)(attr->map_fd); 1951 map = __bpf_map_get(f); 1952 if (IS_ERR(map)) 1953 return PTR_ERR(map); 1954 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1955 return -EPERM; 1956 1957 if (ukey) { 1958 key = __bpf_copy_key(ukey, map->key_size); 1959 if (IS_ERR(key)) 1960 return PTR_ERR(key); 1961 } else { 1962 key = NULL; 1963 } 1964 1965 err = -ENOMEM; 1966 next_key = kvmalloc(map->key_size, GFP_USER); 1967 if (!next_key) 1968 goto free_key; 1969 1970 if (bpf_map_is_offloaded(map)) { 1971 err = bpf_map_offload_get_next_key(map, key, next_key); 1972 goto out; 1973 } 1974 1975 rcu_read_lock(); 1976 err = map->ops->map_get_next_key(map, key, next_key); 1977 rcu_read_unlock(); 1978 out: 1979 if (err) 1980 goto free_next_key; 1981 1982 err = -EFAULT; 1983 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1984 goto free_next_key; 1985 1986 err = 0; 1987 1988 free_next_key: 1989 kvfree(next_key); 1990 free_key: 1991 kvfree(key); 1992 return err; 1993 } 1994 1995 int generic_map_delete_batch(struct bpf_map *map, 1996 const union bpf_attr *attr, 1997 union bpf_attr __user *uattr) 1998 { 1999 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2000 u32 cp, max_count; 2001 int err = 0; 2002 void *key; 2003 2004 if (attr->batch.elem_flags & ~BPF_F_LOCK) 2005 return -EINVAL; 2006 2007 if ((attr->batch.elem_flags & BPF_F_LOCK) && 2008 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2009 return -EINVAL; 2010 } 2011 2012 max_count = attr->batch.count; 2013 if (!max_count) 2014 return 0; 2015 2016 if (put_user(0, &uattr->batch.count)) 2017 return -EFAULT; 2018 2019 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2020 if (!key) 2021 return -ENOMEM; 2022 2023 for (cp = 0; cp < max_count; cp++) { 2024 err = -EFAULT; 2025 if (copy_from_user(key, keys + cp * map->key_size, 2026 map->key_size)) 2027 break; 2028 2029 if (bpf_map_is_offloaded(map)) { 2030 err = bpf_map_offload_delete_elem(map, key); 2031 break; 2032 } 2033 2034 bpf_disable_instrumentation(); 2035 rcu_read_lock(); 2036 err = map->ops->map_delete_elem(map, key); 2037 rcu_read_unlock(); 2038 bpf_enable_instrumentation(); 2039 if (err) 2040 break; 2041 cond_resched(); 2042 } 2043 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2044 err = -EFAULT; 2045 2046 kvfree(key); 2047 2048 return err; 2049 } 2050 2051 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 2052 const union bpf_attr *attr, 2053 union bpf_attr __user *uattr) 2054 { 2055 void __user *values = u64_to_user_ptr(attr->batch.values); 2056 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2057 u32 value_size, cp, max_count; 2058 void *key, *value; 2059 int err = 0; 2060 2061 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, 2062 BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS); 2063 if (err) 2064 return err; 2065 2066 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2067 2068 max_count = attr->batch.count; 2069 if (!max_count) 2070 return 0; 2071 2072 if (put_user(0, &uattr->batch.count)) 2073 return -EFAULT; 2074 2075 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2076 if (!key) 2077 return -ENOMEM; 2078 2079 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2080 if (!value) { 2081 kvfree(key); 2082 return -ENOMEM; 2083 } 2084 2085 for (cp = 0; cp < max_count; cp++) { 2086 err = -EFAULT; 2087 if (copy_from_user(key, keys + cp * map->key_size, 2088 map->key_size) || 2089 copy_from_user(value, values + cp * value_size, value_size)) 2090 break; 2091 2092 err = bpf_map_update_value(map, map_file, key, value, 2093 attr->batch.elem_flags); 2094 2095 if (err) 2096 break; 2097 cond_resched(); 2098 } 2099 2100 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2101 err = -EFAULT; 2102 2103 kvfree(value); 2104 kvfree(key); 2105 2106 return err; 2107 } 2108 2109 int generic_map_lookup_batch(struct bpf_map *map, 2110 const union bpf_attr *attr, 2111 union bpf_attr __user *uattr) 2112 { 2113 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 2114 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 2115 void __user *values = u64_to_user_ptr(attr->batch.values); 2116 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2117 void *buf, *buf_prevkey, *prev_key, *key, *value; 2118 u32 value_size, cp, max_count; 2119 int err; 2120 2121 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU); 2122 if (err) 2123 return err; 2124 2125 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2126 2127 max_count = attr->batch.count; 2128 if (!max_count) 2129 return 0; 2130 2131 if (put_user(0, &uattr->batch.count)) 2132 return -EFAULT; 2133 2134 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2135 if (!buf_prevkey) 2136 return -ENOMEM; 2137 2138 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 2139 if (!buf) { 2140 kvfree(buf_prevkey); 2141 return -ENOMEM; 2142 } 2143 2144 err = -EFAULT; 2145 prev_key = NULL; 2146 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 2147 goto free_buf; 2148 key = buf; 2149 value = key + map->key_size; 2150 if (ubatch) 2151 prev_key = buf_prevkey; 2152 2153 for (cp = 0; cp < max_count;) { 2154 rcu_read_lock(); 2155 err = map->ops->map_get_next_key(map, prev_key, key); 2156 rcu_read_unlock(); 2157 if (err) 2158 break; 2159 err = bpf_map_copy_value(map, key, value, 2160 attr->batch.elem_flags); 2161 2162 if (err == -ENOENT) 2163 goto next_key; 2164 2165 if (err) 2166 goto free_buf; 2167 2168 if (copy_to_user(keys + cp * map->key_size, key, 2169 map->key_size)) { 2170 err = -EFAULT; 2171 goto free_buf; 2172 } 2173 if (copy_to_user(values + cp * value_size, value, value_size)) { 2174 err = -EFAULT; 2175 goto free_buf; 2176 } 2177 2178 cp++; 2179 next_key: 2180 if (!prev_key) 2181 prev_key = buf_prevkey; 2182 2183 swap(prev_key, key); 2184 cond_resched(); 2185 } 2186 2187 if (err == -EFAULT) 2188 goto free_buf; 2189 2190 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 2191 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 2192 err = -EFAULT; 2193 2194 free_buf: 2195 kvfree(buf_prevkey); 2196 kvfree(buf); 2197 return err; 2198 } 2199 2200 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 2201 2202 static int map_lookup_and_delete_elem(union bpf_attr *attr) 2203 { 2204 void __user *ukey = u64_to_user_ptr(attr->key); 2205 void __user *uvalue = u64_to_user_ptr(attr->value); 2206 struct bpf_map *map; 2207 void *key, *value; 2208 u32 value_size; 2209 int err; 2210 2211 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 2212 return -EINVAL; 2213 2214 if (attr->flags & ~BPF_F_LOCK) 2215 return -EINVAL; 2216 2217 CLASS(fd, f)(attr->map_fd); 2218 map = __bpf_map_get(f); 2219 if (IS_ERR(map)) 2220 return PTR_ERR(map); 2221 bpf_map_write_active_inc(map); 2222 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 2223 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2224 err = -EPERM; 2225 goto err_put; 2226 } 2227 2228 if (attr->flags && 2229 (map->map_type == BPF_MAP_TYPE_QUEUE || 2230 map->map_type == BPF_MAP_TYPE_STACK)) { 2231 err = -EINVAL; 2232 goto err_put; 2233 } 2234 2235 if ((attr->flags & BPF_F_LOCK) && 2236 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2237 err = -EINVAL; 2238 goto err_put; 2239 } 2240 2241 key = __bpf_copy_key(ukey, map->key_size); 2242 if (IS_ERR(key)) { 2243 err = PTR_ERR(key); 2244 goto err_put; 2245 } 2246 2247 value_size = bpf_map_value_size(map, 0); 2248 2249 err = -ENOMEM; 2250 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2251 if (!value) 2252 goto free_key; 2253 2254 err = -ENOTSUPP; 2255 if (map->map_type == BPF_MAP_TYPE_QUEUE || 2256 map->map_type == BPF_MAP_TYPE_STACK) { 2257 err = map->ops->map_pop_elem(map, value); 2258 } else if (map->map_type == BPF_MAP_TYPE_HASH || 2259 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 2260 map->map_type == BPF_MAP_TYPE_LRU_HASH || 2261 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 2262 map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 2263 if (!bpf_map_is_offloaded(map)) { 2264 bpf_disable_instrumentation(); 2265 rcu_read_lock(); 2266 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 2267 rcu_read_unlock(); 2268 bpf_enable_instrumentation(); 2269 } 2270 } 2271 2272 if (err) 2273 goto free_value; 2274 2275 if (copy_to_user(uvalue, value, value_size) != 0) { 2276 err = -EFAULT; 2277 goto free_value; 2278 } 2279 2280 err = 0; 2281 2282 free_value: 2283 kvfree(value); 2284 free_key: 2285 kvfree(key); 2286 err_put: 2287 bpf_map_write_active_dec(map); 2288 return err; 2289 } 2290 2291 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2292 2293 static int map_freeze(const union bpf_attr *attr) 2294 { 2295 int err = 0; 2296 struct bpf_map *map; 2297 2298 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2299 return -EINVAL; 2300 2301 CLASS(fd, f)(attr->map_fd); 2302 map = __bpf_map_get(f); 2303 if (IS_ERR(map)) 2304 return PTR_ERR(map); 2305 2306 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) 2307 return -ENOTSUPP; 2308 2309 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) 2310 return -EPERM; 2311 2312 mutex_lock(&map->freeze_mutex); 2313 if (bpf_map_write_active(map)) { 2314 err = -EBUSY; 2315 goto err_put; 2316 } 2317 if (READ_ONCE(map->frozen)) { 2318 err = -EBUSY; 2319 goto err_put; 2320 } 2321 2322 WRITE_ONCE(map->frozen, true); 2323 err_put: 2324 mutex_unlock(&map->freeze_mutex); 2325 return err; 2326 } 2327 2328 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2329 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2330 [_id] = & _name ## _prog_ops, 2331 #define BPF_MAP_TYPE(_id, _ops) 2332 #define BPF_LINK_TYPE(_id, _name) 2333 #include <linux/bpf_types.h> 2334 #undef BPF_PROG_TYPE 2335 #undef BPF_MAP_TYPE 2336 #undef BPF_LINK_TYPE 2337 }; 2338 2339 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2340 { 2341 const struct bpf_prog_ops *ops; 2342 2343 if (type >= ARRAY_SIZE(bpf_prog_types)) 2344 return -EINVAL; 2345 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2346 ops = bpf_prog_types[type]; 2347 if (!ops) 2348 return -EINVAL; 2349 2350 if (!bpf_prog_is_offloaded(prog->aux)) 2351 prog->aux->ops = ops; 2352 else 2353 prog->aux->ops = &bpf_offload_prog_ops; 2354 prog->type = type; 2355 return 0; 2356 } 2357 2358 enum bpf_audit { 2359 BPF_AUDIT_LOAD, 2360 BPF_AUDIT_UNLOAD, 2361 BPF_AUDIT_MAX, 2362 }; 2363 2364 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2365 [BPF_AUDIT_LOAD] = "LOAD", 2366 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2367 }; 2368 2369 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2370 { 2371 struct audit_context *ctx = NULL; 2372 struct audit_buffer *ab; 2373 2374 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2375 return; 2376 if (audit_enabled == AUDIT_OFF) 2377 return; 2378 if (!in_hardirq() && !irqs_disabled()) 2379 ctx = audit_context(); 2380 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2381 if (unlikely(!ab)) 2382 return; 2383 audit_log_format(ab, "prog-id=%u op=%s", 2384 prog->aux->id, bpf_audit_str[op]); 2385 audit_log_end(ab); 2386 } 2387 2388 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2389 { 2390 int id; 2391 2392 idr_preload(GFP_KERNEL); 2393 spin_lock_bh(&prog_idr_lock); 2394 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2395 if (id > 0) 2396 prog->aux->id = id; 2397 spin_unlock_bh(&prog_idr_lock); 2398 idr_preload_end(); 2399 2400 /* id is in [1, INT_MAX) */ 2401 if (WARN_ON_ONCE(!id)) 2402 return -ENOSPC; 2403 2404 return id > 0 ? 0 : id; 2405 } 2406 2407 void bpf_prog_free_id(struct bpf_prog *prog) 2408 { 2409 unsigned long flags; 2410 2411 /* cBPF to eBPF migrations are currently not in the idr store. 2412 * Offloaded programs are removed from the store when their device 2413 * disappears - even if someone grabs an fd to them they are unusable, 2414 * simply waiting for refcnt to drop to be freed. 2415 */ 2416 if (!prog->aux->id) 2417 return; 2418 2419 spin_lock_irqsave(&prog_idr_lock, flags); 2420 idr_remove(&prog_idr, prog->aux->id); 2421 prog->aux->id = 0; 2422 spin_unlock_irqrestore(&prog_idr_lock, flags); 2423 } 2424 2425 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2426 { 2427 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2428 2429 kvfree(aux->func_info); 2430 kfree(aux->func_info_aux); 2431 free_uid(aux->user); 2432 security_bpf_prog_free(aux->prog); 2433 bpf_prog_free(aux->prog); 2434 } 2435 2436 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2437 { 2438 bpf_prog_kallsyms_del_all(prog); 2439 btf_put(prog->aux->btf); 2440 module_put(prog->aux->mod); 2441 kvfree(prog->aux->jited_linfo); 2442 kvfree(prog->aux->linfo); 2443 kfree(prog->aux->kfunc_tab); 2444 kfree(prog->aux->ctx_arg_info); 2445 if (prog->aux->attach_btf) 2446 btf_put(prog->aux->attach_btf); 2447 2448 if (deferred) { 2449 if (prog->sleepable) 2450 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2451 else 2452 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2453 } else { 2454 __bpf_prog_put_rcu(&prog->aux->rcu); 2455 } 2456 } 2457 2458 static void bpf_prog_put_deferred(struct work_struct *work) 2459 { 2460 struct bpf_prog_aux *aux; 2461 struct bpf_prog *prog; 2462 2463 aux = container_of(work, struct bpf_prog_aux, work); 2464 prog = aux->prog; 2465 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2466 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2467 bpf_prog_free_id(prog); 2468 __bpf_prog_put_noref(prog, true); 2469 } 2470 2471 static void __bpf_prog_put(struct bpf_prog *prog) 2472 { 2473 struct bpf_prog_aux *aux = prog->aux; 2474 2475 if (atomic64_dec_and_test(&aux->refcnt)) { 2476 if (in_hardirq() || irqs_disabled()) { 2477 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2478 schedule_work(&aux->work); 2479 } else { 2480 bpf_prog_put_deferred(&aux->work); 2481 } 2482 } 2483 } 2484 2485 void bpf_prog_put(struct bpf_prog *prog) 2486 { 2487 __bpf_prog_put(prog); 2488 } 2489 EXPORT_SYMBOL_GPL(bpf_prog_put); 2490 2491 static int bpf_prog_release(struct inode *inode, struct file *filp) 2492 { 2493 struct bpf_prog *prog = filp->private_data; 2494 2495 bpf_prog_put(prog); 2496 return 0; 2497 } 2498 2499 struct bpf_prog_kstats { 2500 u64 nsecs; 2501 u64 cnt; 2502 u64 misses; 2503 }; 2504 2505 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2506 { 2507 struct bpf_prog_stats *stats; 2508 unsigned int flags; 2509 2510 if (unlikely(!prog->stats)) 2511 return; 2512 2513 stats = this_cpu_ptr(prog->stats); 2514 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2515 u64_stats_inc(&stats->misses); 2516 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2517 } 2518 2519 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2520 struct bpf_prog_kstats *stats) 2521 { 2522 u64 nsecs = 0, cnt = 0, misses = 0; 2523 int cpu; 2524 2525 for_each_possible_cpu(cpu) { 2526 const struct bpf_prog_stats *st; 2527 unsigned int start; 2528 u64 tnsecs, tcnt, tmisses; 2529 2530 st = per_cpu_ptr(prog->stats, cpu); 2531 do { 2532 start = u64_stats_fetch_begin(&st->syncp); 2533 tnsecs = u64_stats_read(&st->nsecs); 2534 tcnt = u64_stats_read(&st->cnt); 2535 tmisses = u64_stats_read(&st->misses); 2536 } while (u64_stats_fetch_retry(&st->syncp, start)); 2537 nsecs += tnsecs; 2538 cnt += tcnt; 2539 misses += tmisses; 2540 } 2541 stats->nsecs = nsecs; 2542 stats->cnt = cnt; 2543 stats->misses = misses; 2544 } 2545 2546 #ifdef CONFIG_PROC_FS 2547 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2548 { 2549 const struct bpf_prog *prog = filp->private_data; 2550 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2551 struct bpf_prog_kstats stats; 2552 2553 bpf_prog_get_stats(prog, &stats); 2554 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2555 seq_printf(m, 2556 "prog_type:\t%u\n" 2557 "prog_jited:\t%u\n" 2558 "prog_tag:\t%s\n" 2559 "memlock:\t%llu\n" 2560 "prog_id:\t%u\n" 2561 "run_time_ns:\t%llu\n" 2562 "run_cnt:\t%llu\n" 2563 "recursion_misses:\t%llu\n" 2564 "verified_insns:\t%u\n", 2565 prog->type, 2566 prog->jited, 2567 prog_tag, 2568 prog->pages * 1ULL << PAGE_SHIFT, 2569 prog->aux->id, 2570 stats.nsecs, 2571 stats.cnt, 2572 stats.misses, 2573 prog->aux->verified_insns); 2574 } 2575 #endif 2576 2577 const struct file_operations bpf_prog_fops = { 2578 #ifdef CONFIG_PROC_FS 2579 .show_fdinfo = bpf_prog_show_fdinfo, 2580 #endif 2581 .release = bpf_prog_release, 2582 .read = bpf_dummy_read, 2583 .write = bpf_dummy_write, 2584 }; 2585 2586 int bpf_prog_new_fd(struct bpf_prog *prog) 2587 { 2588 int ret; 2589 2590 ret = security_bpf_prog(prog); 2591 if (ret < 0) 2592 return ret; 2593 2594 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2595 O_RDWR | O_CLOEXEC); 2596 } 2597 2598 void bpf_prog_add(struct bpf_prog *prog, int i) 2599 { 2600 atomic64_add(i, &prog->aux->refcnt); 2601 } 2602 EXPORT_SYMBOL_GPL(bpf_prog_add); 2603 2604 void bpf_prog_sub(struct bpf_prog *prog, int i) 2605 { 2606 /* Only to be used for undoing previous bpf_prog_add() in some 2607 * error path. We still know that another entity in our call 2608 * path holds a reference to the program, thus atomic_sub() can 2609 * be safely used in such cases! 2610 */ 2611 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2612 } 2613 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2614 2615 void bpf_prog_inc(struct bpf_prog *prog) 2616 { 2617 atomic64_inc(&prog->aux->refcnt); 2618 } 2619 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2620 2621 /* prog_idr_lock should have been held */ 2622 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2623 { 2624 int refold; 2625 2626 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2627 2628 if (!refold) 2629 return ERR_PTR(-ENOENT); 2630 2631 return prog; 2632 } 2633 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2634 2635 bool bpf_prog_get_ok(struct bpf_prog *prog, 2636 enum bpf_prog_type *attach_type, bool attach_drv) 2637 { 2638 /* not an attachment, just a refcount inc, always allow */ 2639 if (!attach_type) 2640 return true; 2641 2642 if (prog->type != *attach_type) 2643 return false; 2644 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2645 return false; 2646 2647 return true; 2648 } 2649 2650 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2651 bool attach_drv) 2652 { 2653 CLASS(fd, f)(ufd); 2654 struct bpf_prog *prog; 2655 2656 if (fd_empty(f)) 2657 return ERR_PTR(-EBADF); 2658 if (fd_file(f)->f_op != &bpf_prog_fops) 2659 return ERR_PTR(-EINVAL); 2660 2661 prog = fd_file(f)->private_data; 2662 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2663 return ERR_PTR(-EINVAL); 2664 2665 bpf_prog_inc(prog); 2666 return prog; 2667 } 2668 2669 struct bpf_prog *bpf_prog_get(u32 ufd) 2670 { 2671 return __bpf_prog_get(ufd, NULL, false); 2672 } 2673 2674 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2675 bool attach_drv) 2676 { 2677 return __bpf_prog_get(ufd, &type, attach_drv); 2678 } 2679 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2680 2681 /* Initially all BPF programs could be loaded w/o specifying 2682 * expected_attach_type. Later for some of them specifying expected_attach_type 2683 * at load time became required so that program could be validated properly. 2684 * Programs of types that are allowed to be loaded both w/ and w/o (for 2685 * backward compatibility) expected_attach_type, should have the default attach 2686 * type assigned to expected_attach_type for the latter case, so that it can be 2687 * validated later at attach time. 2688 * 2689 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2690 * prog type requires it but has some attach types that have to be backward 2691 * compatible. 2692 */ 2693 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2694 { 2695 switch (attr->prog_type) { 2696 case BPF_PROG_TYPE_CGROUP_SOCK: 2697 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2698 * exist so checking for non-zero is the way to go here. 2699 */ 2700 if (!attr->expected_attach_type) 2701 attr->expected_attach_type = 2702 BPF_CGROUP_INET_SOCK_CREATE; 2703 break; 2704 case BPF_PROG_TYPE_SK_REUSEPORT: 2705 if (!attr->expected_attach_type) 2706 attr->expected_attach_type = 2707 BPF_SK_REUSEPORT_SELECT; 2708 break; 2709 } 2710 } 2711 2712 static int 2713 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2714 enum bpf_attach_type expected_attach_type, 2715 struct btf *attach_btf, u32 btf_id, 2716 struct bpf_prog *dst_prog) 2717 { 2718 if (btf_id) { 2719 if (btf_id > BTF_MAX_TYPE) 2720 return -EINVAL; 2721 2722 if (!attach_btf && !dst_prog) 2723 return -EINVAL; 2724 2725 switch (prog_type) { 2726 case BPF_PROG_TYPE_TRACING: 2727 case BPF_PROG_TYPE_LSM: 2728 case BPF_PROG_TYPE_STRUCT_OPS: 2729 case BPF_PROG_TYPE_EXT: 2730 break; 2731 default: 2732 return -EINVAL; 2733 } 2734 } 2735 2736 if (attach_btf && (!btf_id || dst_prog)) 2737 return -EINVAL; 2738 2739 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2740 prog_type != BPF_PROG_TYPE_EXT) 2741 return -EINVAL; 2742 2743 switch (prog_type) { 2744 case BPF_PROG_TYPE_CGROUP_SOCK: 2745 switch (expected_attach_type) { 2746 case BPF_CGROUP_INET_SOCK_CREATE: 2747 case BPF_CGROUP_INET_SOCK_RELEASE: 2748 case BPF_CGROUP_INET4_POST_BIND: 2749 case BPF_CGROUP_INET6_POST_BIND: 2750 return 0; 2751 default: 2752 return -EINVAL; 2753 } 2754 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2755 switch (expected_attach_type) { 2756 case BPF_CGROUP_INET4_BIND: 2757 case BPF_CGROUP_INET6_BIND: 2758 case BPF_CGROUP_INET4_CONNECT: 2759 case BPF_CGROUP_INET6_CONNECT: 2760 case BPF_CGROUP_UNIX_CONNECT: 2761 case BPF_CGROUP_INET4_GETPEERNAME: 2762 case BPF_CGROUP_INET6_GETPEERNAME: 2763 case BPF_CGROUP_UNIX_GETPEERNAME: 2764 case BPF_CGROUP_INET4_GETSOCKNAME: 2765 case BPF_CGROUP_INET6_GETSOCKNAME: 2766 case BPF_CGROUP_UNIX_GETSOCKNAME: 2767 case BPF_CGROUP_UDP4_SENDMSG: 2768 case BPF_CGROUP_UDP6_SENDMSG: 2769 case BPF_CGROUP_UNIX_SENDMSG: 2770 case BPF_CGROUP_UDP4_RECVMSG: 2771 case BPF_CGROUP_UDP6_RECVMSG: 2772 case BPF_CGROUP_UNIX_RECVMSG: 2773 return 0; 2774 default: 2775 return -EINVAL; 2776 } 2777 case BPF_PROG_TYPE_CGROUP_SKB: 2778 switch (expected_attach_type) { 2779 case BPF_CGROUP_INET_INGRESS: 2780 case BPF_CGROUP_INET_EGRESS: 2781 return 0; 2782 default: 2783 return -EINVAL; 2784 } 2785 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2786 switch (expected_attach_type) { 2787 case BPF_CGROUP_SETSOCKOPT: 2788 case BPF_CGROUP_GETSOCKOPT: 2789 return 0; 2790 default: 2791 return -EINVAL; 2792 } 2793 case BPF_PROG_TYPE_SK_LOOKUP: 2794 if (expected_attach_type == BPF_SK_LOOKUP) 2795 return 0; 2796 return -EINVAL; 2797 case BPF_PROG_TYPE_SK_REUSEPORT: 2798 switch (expected_attach_type) { 2799 case BPF_SK_REUSEPORT_SELECT: 2800 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2801 return 0; 2802 default: 2803 return -EINVAL; 2804 } 2805 case BPF_PROG_TYPE_NETFILTER: 2806 if (expected_attach_type == BPF_NETFILTER) 2807 return 0; 2808 return -EINVAL; 2809 case BPF_PROG_TYPE_SYSCALL: 2810 case BPF_PROG_TYPE_EXT: 2811 if (expected_attach_type) 2812 return -EINVAL; 2813 fallthrough; 2814 default: 2815 return 0; 2816 } 2817 } 2818 2819 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2820 { 2821 switch (prog_type) { 2822 case BPF_PROG_TYPE_SCHED_CLS: 2823 case BPF_PROG_TYPE_SCHED_ACT: 2824 case BPF_PROG_TYPE_XDP: 2825 case BPF_PROG_TYPE_LWT_IN: 2826 case BPF_PROG_TYPE_LWT_OUT: 2827 case BPF_PROG_TYPE_LWT_XMIT: 2828 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2829 case BPF_PROG_TYPE_SK_SKB: 2830 case BPF_PROG_TYPE_SK_MSG: 2831 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2832 case BPF_PROG_TYPE_CGROUP_DEVICE: 2833 case BPF_PROG_TYPE_CGROUP_SOCK: 2834 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2835 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2836 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2837 case BPF_PROG_TYPE_SOCK_OPS: 2838 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2839 case BPF_PROG_TYPE_NETFILTER: 2840 return true; 2841 case BPF_PROG_TYPE_CGROUP_SKB: 2842 /* always unpriv */ 2843 case BPF_PROG_TYPE_SK_REUSEPORT: 2844 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2845 default: 2846 return false; 2847 } 2848 } 2849 2850 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2851 { 2852 switch (prog_type) { 2853 case BPF_PROG_TYPE_KPROBE: 2854 case BPF_PROG_TYPE_TRACEPOINT: 2855 case BPF_PROG_TYPE_PERF_EVENT: 2856 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2857 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2858 case BPF_PROG_TYPE_TRACING: 2859 case BPF_PROG_TYPE_LSM: 2860 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2861 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2862 return true; 2863 default: 2864 return false; 2865 } 2866 } 2867 2868 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr, 2869 bool is_kernel) 2870 { 2871 bpfptr_t usig = make_bpfptr(attr->signature, is_kernel); 2872 struct bpf_dynptr_kern sig_ptr, insns_ptr; 2873 struct bpf_key *key = NULL; 2874 void *sig; 2875 int err = 0; 2876 2877 /* 2878 * Don't attempt to use kmalloc_large or vmalloc for signatures. 2879 * Practical signature for BPF program should be below this limit. 2880 */ 2881 if (attr->signature_size > KMALLOC_MAX_CACHE_SIZE) 2882 return -EINVAL; 2883 2884 if (system_keyring_id_check(attr->keyring_id) == 0) 2885 key = bpf_lookup_system_key(attr->keyring_id); 2886 else 2887 key = bpf_lookup_user_key(attr->keyring_id, 0); 2888 2889 if (!key) 2890 return -EINVAL; 2891 2892 sig = kvmemdup_bpfptr(usig, attr->signature_size); 2893 if (IS_ERR(sig)) { 2894 bpf_key_put(key); 2895 return PTR_ERR(sig); 2896 } 2897 2898 bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0, 2899 attr->signature_size); 2900 bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0, 2901 prog->len * sizeof(struct bpf_insn)); 2902 2903 err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr, 2904 (struct bpf_dynptr *)&sig_ptr, key); 2905 2906 bpf_key_put(key); 2907 kvfree(sig); 2908 return err; 2909 } 2910 2911 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) 2912 { 2913 int err; 2914 int i; 2915 2916 for (i = 0; i < prog->aux->used_map_cnt; i++) { 2917 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY) 2918 continue; 2919 2920 err = bpf_insn_array_ready(prog->aux->used_maps[i]); 2921 if (err) 2922 return err; 2923 } 2924 2925 return 0; 2926 } 2927 2928 /* last field in 'union bpf_attr' used by this command */ 2929 #define BPF_PROG_LOAD_LAST_FIELD keyring_id 2930 2931 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 2932 { 2933 enum bpf_prog_type type = attr->prog_type; 2934 struct bpf_prog *prog, *dst_prog = NULL; 2935 struct btf *attach_btf = NULL; 2936 struct bpf_token *token = NULL; 2937 bool bpf_cap; 2938 int err; 2939 char license[128]; 2940 2941 if (CHECK_ATTR(BPF_PROG_LOAD)) 2942 return -EINVAL; 2943 2944 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2945 BPF_F_ANY_ALIGNMENT | 2946 BPF_F_TEST_STATE_FREQ | 2947 BPF_F_SLEEPABLE | 2948 BPF_F_TEST_RND_HI32 | 2949 BPF_F_XDP_HAS_FRAGS | 2950 BPF_F_XDP_DEV_BOUND_ONLY | 2951 BPF_F_TEST_REG_INVARIANTS | 2952 BPF_F_TOKEN_FD)) 2953 return -EINVAL; 2954 2955 bpf_prog_load_fixup_attach_type(attr); 2956 2957 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2958 token = bpf_token_get_from_fd(attr->prog_token_fd); 2959 if (IS_ERR(token)) 2960 return PTR_ERR(token); 2961 /* if current token doesn't grant prog loading permissions, 2962 * then we can't use this token, so ignore it and rely on 2963 * system-wide capabilities checks 2964 */ 2965 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2966 !bpf_token_allow_prog_type(token, attr->prog_type, 2967 attr->expected_attach_type)) { 2968 bpf_token_put(token); 2969 token = NULL; 2970 } 2971 } 2972 2973 bpf_cap = bpf_token_capable(token, CAP_BPF); 2974 err = -EPERM; 2975 2976 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2977 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2978 !bpf_cap) 2979 goto put_token; 2980 2981 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2982 * creation for unprivileged users; other actions depend 2983 * on fd availability and access to bpffs, so are dependent on 2984 * object creation success. Even with unprivileged BPF disabled, 2985 * capability checks are still carried out for these 2986 * and other operations. 2987 */ 2988 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 2989 goto put_token; 2990 2991 if (attr->insn_cnt == 0 || 2992 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 2993 err = -E2BIG; 2994 goto put_token; 2995 } 2996 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2997 type != BPF_PROG_TYPE_CGROUP_SKB && 2998 !bpf_cap) 2999 goto put_token; 3000 3001 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 3002 goto put_token; 3003 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 3004 goto put_token; 3005 3006 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 3007 * or btf, we need to check which one it is 3008 */ 3009 if (attr->attach_prog_fd) { 3010 dst_prog = bpf_prog_get(attr->attach_prog_fd); 3011 if (IS_ERR(dst_prog)) { 3012 dst_prog = NULL; 3013 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 3014 if (IS_ERR(attach_btf)) { 3015 err = -EINVAL; 3016 goto put_token; 3017 } 3018 if (!btf_is_kernel(attach_btf)) { 3019 /* attaching through specifying bpf_prog's BTF 3020 * objects directly might be supported eventually 3021 */ 3022 btf_put(attach_btf); 3023 err = -ENOTSUPP; 3024 goto put_token; 3025 } 3026 } 3027 } else if (attr->attach_btf_id) { 3028 /* fall back to vmlinux BTF, if BTF type ID is specified */ 3029 attach_btf = bpf_get_btf_vmlinux(); 3030 if (IS_ERR(attach_btf)) { 3031 err = PTR_ERR(attach_btf); 3032 goto put_token; 3033 } 3034 if (!attach_btf) { 3035 err = -EINVAL; 3036 goto put_token; 3037 } 3038 btf_get(attach_btf); 3039 } 3040 3041 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 3042 attach_btf, attr->attach_btf_id, 3043 dst_prog)) { 3044 if (dst_prog) 3045 bpf_prog_put(dst_prog); 3046 if (attach_btf) 3047 btf_put(attach_btf); 3048 err = -EINVAL; 3049 goto put_token; 3050 } 3051 3052 /* plain bpf_prog allocation */ 3053 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 3054 if (!prog) { 3055 if (dst_prog) 3056 bpf_prog_put(dst_prog); 3057 if (attach_btf) 3058 btf_put(attach_btf); 3059 err = -EINVAL; 3060 goto put_token; 3061 } 3062 3063 prog->expected_attach_type = attr->expected_attach_type; 3064 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 3065 prog->aux->attach_btf = attach_btf; 3066 prog->aux->attach_btf_id = attr->attach_btf_id; 3067 prog->aux->dst_prog = dst_prog; 3068 prog->aux->dev_bound = !!attr->prog_ifindex; 3069 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 3070 3071 /* move token into prog->aux, reuse taken refcnt */ 3072 prog->aux->token = token; 3073 token = NULL; 3074 3075 prog->aux->user = get_current_user(); 3076 prog->len = attr->insn_cnt; 3077 3078 err = -EFAULT; 3079 if (copy_from_bpfptr(prog->insns, 3080 make_bpfptr(attr->insns, uattr.is_kernel), 3081 bpf_prog_insn_size(prog)) != 0) 3082 goto free_prog; 3083 /* copy eBPF program license from user space */ 3084 if (strncpy_from_bpfptr(license, 3085 make_bpfptr(attr->license, uattr.is_kernel), 3086 sizeof(license) - 1) < 0) 3087 goto free_prog; 3088 license[sizeof(license) - 1] = 0; 3089 3090 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 3091 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 3092 3093 if (attr->signature) { 3094 err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel); 3095 if (err) 3096 goto free_prog; 3097 } 3098 3099 prog->orig_prog = NULL; 3100 prog->jited = 0; 3101 3102 atomic64_set(&prog->aux->refcnt, 1); 3103 3104 if (bpf_prog_is_dev_bound(prog->aux)) { 3105 err = bpf_prog_dev_bound_init(prog, attr); 3106 if (err) 3107 goto free_prog; 3108 } 3109 3110 if (type == BPF_PROG_TYPE_EXT && dst_prog && 3111 bpf_prog_is_dev_bound(dst_prog->aux)) { 3112 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 3113 if (err) 3114 goto free_prog; 3115 } 3116 3117 /* 3118 * Bookkeeping for managing the program attachment chain. 3119 * 3120 * It might be tempting to set attach_tracing_prog flag at the attachment 3121 * time, but this will not prevent from loading bunch of tracing prog 3122 * first, then attach them one to another. 3123 * 3124 * The flag attach_tracing_prog is set for the whole program lifecycle, and 3125 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 3126 * programs cannot change attachment target. 3127 */ 3128 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 3129 dst_prog->type == BPF_PROG_TYPE_TRACING) { 3130 prog->aux->attach_tracing_prog = true; 3131 } 3132 3133 /* find program type: socket_filter vs tracing_filter */ 3134 err = find_prog_type(type, prog); 3135 if (err < 0) 3136 goto free_prog; 3137 3138 prog->aux->load_time = ktime_get_boottime_ns(); 3139 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 3140 sizeof(attr->prog_name)); 3141 if (err < 0) 3142 goto free_prog; 3143 3144 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel); 3145 if (err) 3146 goto free_prog; 3147 3148 /* run eBPF verifier */ 3149 err = bpf_check(&prog, attr, uattr, attr_log); 3150 if (err < 0) 3151 goto free_used_maps; 3152 3153 err = bpf_prog_mark_insn_arrays_ready(prog); 3154 if (err < 0) 3155 goto free_used_maps; 3156 3157 err = bpf_prog_alloc_id(prog); 3158 if (err) 3159 goto free_used_maps; 3160 3161 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 3162 * effectively publicly exposed. However, retrieving via 3163 * bpf_prog_get_fd_by_id() will take another reference, 3164 * therefore it cannot be gone underneath us. 3165 * 3166 * Only for the time /after/ successful bpf_prog_new_fd() 3167 * and before returning to userspace, we might just hold 3168 * one reference and any parallel close on that fd could 3169 * rip everything out. Hence, below notifications must 3170 * happen before bpf_prog_new_fd(). 3171 * 3172 * Also, any failure handling from this point onwards must 3173 * be using bpf_prog_put() given the program is exposed. 3174 */ 3175 bpf_prog_kallsyms_add(prog); 3176 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 3177 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 3178 3179 err = bpf_prog_new_fd(prog); 3180 if (err < 0) 3181 bpf_prog_put(prog); 3182 return err; 3183 3184 free_used_maps: 3185 /* In case we have subprogs, we need to wait for a grace 3186 * period before we can tear down JIT memory since symbols 3187 * are already exposed under kallsyms. 3188 */ 3189 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 3190 return err; 3191 3192 free_prog: 3193 free_uid(prog->aux->user); 3194 if (prog->aux->attach_btf) 3195 btf_put(prog->aux->attach_btf); 3196 bpf_prog_free(prog); 3197 put_token: 3198 bpf_token_put(token); 3199 return err; 3200 } 3201 3202 #define BPF_OBJ_LAST_FIELD path_fd 3203 3204 static int bpf_obj_pin(const union bpf_attr *attr) 3205 { 3206 int path_fd; 3207 3208 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3209 return -EINVAL; 3210 3211 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3212 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3213 return -EINVAL; 3214 3215 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3216 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3217 u64_to_user_ptr(attr->pathname)); 3218 } 3219 3220 static int bpf_obj_get(const union bpf_attr *attr) 3221 { 3222 int path_fd; 3223 3224 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3225 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3226 return -EINVAL; 3227 3228 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3229 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3230 return -EINVAL; 3231 3232 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3233 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3234 attr->file_flags); 3235 } 3236 3237 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3238 * "sleepable" semantics, which normally would mean that BPF link's attach 3239 * hook can dereference link or link's underlying program for some time after 3240 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3241 * BPF program itself can be non-sleepable, yet, because it's transitively 3242 * reachable through BPF link, its freeing has to be delayed until after RCU 3243 * Tasks Trace GP. 3244 */ 3245 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3246 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3247 enum bpf_attach_type attach_type, bool sleepable) 3248 { 3249 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3250 atomic64_set(&link->refcnt, 1); 3251 link->type = type; 3252 link->sleepable = sleepable; 3253 link->id = 0; 3254 link->ops = ops; 3255 link->prog = prog; 3256 link->attach_type = attach_type; 3257 } 3258 3259 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3260 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3261 enum bpf_attach_type attach_type) 3262 { 3263 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); 3264 } 3265 3266 static void bpf_link_free_id(int id) 3267 { 3268 if (!id) 3269 return; 3270 3271 spin_lock_bh(&link_idr_lock); 3272 idr_remove(&link_idr, id); 3273 spin_unlock_bh(&link_idr_lock); 3274 } 3275 3276 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3277 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3278 * anon_inode's release() call. This helper marks bpf_link as 3279 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3280 * is not decremented, it's the responsibility of a calling code that failed 3281 * to complete bpf_link initialization. 3282 * This helper eventually calls link's dealloc callback, but does not call 3283 * link's release callback. 3284 */ 3285 void bpf_link_cleanup(struct bpf_link_primer *primer) 3286 { 3287 primer->link->prog = NULL; 3288 bpf_link_free_id(primer->id); 3289 fput(primer->file); 3290 put_unused_fd(primer->fd); 3291 } 3292 3293 void bpf_link_inc(struct bpf_link *link) 3294 { 3295 atomic64_inc(&link->refcnt); 3296 } 3297 3298 static void bpf_link_dealloc(struct bpf_link *link) 3299 { 3300 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3301 if (link->prog) 3302 bpf_prog_put(link->prog); 3303 3304 /* free bpf_link and its containing memory */ 3305 if (link->ops->dealloc_deferred) 3306 link->ops->dealloc_deferred(link); 3307 else 3308 link->ops->dealloc(link); 3309 } 3310 3311 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3312 { 3313 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3314 3315 bpf_link_dealloc(link); 3316 } 3317 3318 static bool bpf_link_is_tracepoint(struct bpf_link *link) 3319 { 3320 /* 3321 * Only these combinations support a tracepoint bpf_link. 3322 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use 3323 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see 3324 * bpf_raw_tp_link_attach(). 3325 */ 3326 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT || 3327 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP); 3328 } 3329 3330 /* bpf_link_free is guaranteed to be called from process context */ 3331 static void bpf_link_free(struct bpf_link *link) 3332 { 3333 const struct bpf_link_ops *ops = link->ops; 3334 3335 bpf_link_free_id(link->id); 3336 /* detach BPF program, clean up used resources */ 3337 if (link->prog) 3338 ops->release(link); 3339 if (ops->dealloc_deferred) { 3340 /* 3341 * Schedule BPF link deallocation, which will only then 3342 * trigger putting BPF program refcount. 3343 * If underlying BPF program is sleepable or BPF link's target 3344 * attach hookpoint is sleepable or otherwise requires RCU GPs 3345 * to ensure link and its underlying BPF program is not 3346 * reachable anymore, we need to first wait for RCU tasks 3347 * trace sync, and then go through "classic" RCU grace period. 3348 * 3349 * For tracepoint BPF links, we need to go through SRCU grace 3350 * period wait instead when non-faultable tracepoint is used. We 3351 * don't need to chain SRCU grace period waits, however, for the 3352 * faultable case, since it exclusively uses RCU Tasks Trace. 3353 */ 3354 if (link->sleepable || (link->prog && link->prog->sleepable)) 3355 /* RCU Tasks Trace grace period implies RCU grace period. */ 3356 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3357 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */ 3358 else if (bpf_link_is_tracepoint(link)) 3359 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3360 else 3361 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3362 } else if (ops->dealloc) { 3363 bpf_link_dealloc(link); 3364 } 3365 } 3366 3367 static void bpf_link_put_deferred(struct work_struct *work) 3368 { 3369 struct bpf_link *link = container_of(work, struct bpf_link, work); 3370 3371 bpf_link_free(link); 3372 } 3373 3374 /* bpf_link_put might be called from atomic context. It needs to be called 3375 * from sleepable context in order to acquire sleeping locks during the process. 3376 */ 3377 void bpf_link_put(struct bpf_link *link) 3378 { 3379 if (!atomic64_dec_and_test(&link->refcnt)) 3380 return; 3381 3382 INIT_WORK(&link->work, bpf_link_put_deferred); 3383 schedule_work(&link->work); 3384 } 3385 EXPORT_SYMBOL(bpf_link_put); 3386 3387 static void bpf_link_put_direct(struct bpf_link *link) 3388 { 3389 if (!atomic64_dec_and_test(&link->refcnt)) 3390 return; 3391 bpf_link_free(link); 3392 } 3393 3394 static int bpf_link_release(struct inode *inode, struct file *filp) 3395 { 3396 struct bpf_link *link = filp->private_data; 3397 3398 bpf_link_put_direct(link); 3399 return 0; 3400 } 3401 3402 #ifdef CONFIG_PROC_FS 3403 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3404 #define BPF_MAP_TYPE(_id, _ops) 3405 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3406 static const char *bpf_link_type_strs[] = { 3407 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3408 #include <linux/bpf_types.h> 3409 }; 3410 #undef BPF_PROG_TYPE 3411 #undef BPF_MAP_TYPE 3412 #undef BPF_LINK_TYPE 3413 3414 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3415 { 3416 const struct bpf_link *link = filp->private_data; 3417 const struct bpf_prog *prog = link->prog; 3418 enum bpf_link_type type = link->type; 3419 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3420 3421 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3422 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) 3423 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? 3424 "kretprobe_multi" : "kprobe_multi"); 3425 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) 3426 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ? 3427 "uretprobe_multi" : "uprobe_multi"); 3428 else 3429 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3430 } else { 3431 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3432 seq_printf(m, "link_type:\t<%u>\n", type); 3433 } 3434 seq_printf(m, "link_id:\t%u\n", link->id); 3435 3436 if (prog) { 3437 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3438 seq_printf(m, 3439 "prog_tag:\t%s\n" 3440 "prog_id:\t%u\n", 3441 prog_tag, 3442 prog->aux->id); 3443 } 3444 if (link->ops->show_fdinfo) 3445 link->ops->show_fdinfo(link, m); 3446 } 3447 #endif 3448 3449 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3450 { 3451 struct bpf_link *link = file->private_data; 3452 3453 return link->ops->poll(file, pts); 3454 } 3455 3456 static const struct file_operations bpf_link_fops = { 3457 #ifdef CONFIG_PROC_FS 3458 .show_fdinfo = bpf_link_show_fdinfo, 3459 #endif 3460 .release = bpf_link_release, 3461 .read = bpf_dummy_read, 3462 .write = bpf_dummy_write, 3463 }; 3464 3465 static const struct file_operations bpf_link_fops_poll = { 3466 #ifdef CONFIG_PROC_FS 3467 .show_fdinfo = bpf_link_show_fdinfo, 3468 #endif 3469 .release = bpf_link_release, 3470 .read = bpf_dummy_read, 3471 .write = bpf_dummy_write, 3472 .poll = bpf_link_poll, 3473 }; 3474 3475 static int bpf_link_alloc_id(struct bpf_link *link) 3476 { 3477 int id; 3478 3479 idr_preload(GFP_KERNEL); 3480 spin_lock_bh(&link_idr_lock); 3481 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3482 spin_unlock_bh(&link_idr_lock); 3483 idr_preload_end(); 3484 3485 return id; 3486 } 3487 3488 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3489 * reserving unused FD and allocating ID from link_idr. This is to be paired 3490 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3491 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3492 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3493 * transient state is passed around in struct bpf_link_primer. 3494 * This is preferred way to create and initialize bpf_link, especially when 3495 * there are complicated and expensive operations in between creating bpf_link 3496 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3497 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3498 * expensive (and potentially failing) roll back operations in a rare case 3499 * that file, FD, or ID can't be allocated. 3500 */ 3501 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3502 { 3503 struct file *file; 3504 int fd, id; 3505 3506 fd = get_unused_fd_flags(O_CLOEXEC); 3507 if (fd < 0) 3508 return fd; 3509 3510 3511 id = bpf_link_alloc_id(link); 3512 if (id < 0) { 3513 put_unused_fd(fd); 3514 return id; 3515 } 3516 3517 file = anon_inode_getfile("bpf_link", 3518 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3519 link, O_CLOEXEC); 3520 if (IS_ERR(file)) { 3521 bpf_link_free_id(id); 3522 put_unused_fd(fd); 3523 return PTR_ERR(file); 3524 } 3525 3526 primer->link = link; 3527 primer->file = file; 3528 primer->fd = fd; 3529 primer->id = id; 3530 return 0; 3531 } 3532 3533 int bpf_link_settle(struct bpf_link_primer *primer) 3534 { 3535 /* make bpf_link fetchable by ID */ 3536 spin_lock_bh(&link_idr_lock); 3537 primer->link->id = primer->id; 3538 spin_unlock_bh(&link_idr_lock); 3539 /* make bpf_link fetchable by FD */ 3540 fd_install(primer->fd, primer->file); 3541 /* pass through installed FD */ 3542 return primer->fd; 3543 } 3544 3545 int bpf_link_new_fd(struct bpf_link *link) 3546 { 3547 return anon_inode_getfd("bpf-link", 3548 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3549 link, O_CLOEXEC); 3550 } 3551 3552 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3553 { 3554 CLASS(fd, f)(ufd); 3555 struct bpf_link *link; 3556 3557 if (fd_empty(f)) 3558 return ERR_PTR(-EBADF); 3559 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3560 return ERR_PTR(-EINVAL); 3561 3562 link = fd_file(f)->private_data; 3563 bpf_link_inc(link); 3564 return link; 3565 } 3566 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); 3567 3568 static void bpf_tracing_link_release(struct bpf_link *link) 3569 { 3570 struct bpf_tracing_link *tr_link = 3571 container_of(link, struct bpf_tracing_link, link.link); 3572 3573 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3574 tr_link->trampoline, 3575 tr_link->tgt_prog)); 3576 3577 bpf_trampoline_put(tr_link->trampoline); 3578 3579 /* tgt_prog is NULL if target is a kernel function */ 3580 if (tr_link->tgt_prog) 3581 bpf_prog_put(tr_link->tgt_prog); 3582 } 3583 3584 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3585 { 3586 struct bpf_tracing_link *tr_link = 3587 container_of(link, struct bpf_tracing_link, link.link); 3588 3589 kfree(tr_link); 3590 } 3591 3592 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3593 struct seq_file *seq) 3594 { 3595 struct bpf_tracing_link *tr_link = 3596 container_of(link, struct bpf_tracing_link, link.link); 3597 u32 target_btf_id, target_obj_id; 3598 3599 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3600 &target_obj_id, &target_btf_id); 3601 seq_printf(seq, 3602 "attach_type:\t%d\n" 3603 "target_obj_id:\t%u\n" 3604 "target_btf_id:\t%u\n" 3605 "cookie:\t%llu\n", 3606 link->attach_type, 3607 target_obj_id, 3608 target_btf_id, 3609 tr_link->link.cookie); 3610 } 3611 3612 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3613 struct bpf_link_info *info) 3614 { 3615 struct bpf_tracing_link *tr_link = 3616 container_of(link, struct bpf_tracing_link, link.link); 3617 3618 info->tracing.attach_type = link->attach_type; 3619 info->tracing.cookie = tr_link->link.cookie; 3620 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3621 &info->tracing.target_obj_id, 3622 &info->tracing.target_btf_id); 3623 3624 return 0; 3625 } 3626 3627 static const struct bpf_link_ops bpf_tracing_link_lops = { 3628 .release = bpf_tracing_link_release, 3629 .dealloc = bpf_tracing_link_dealloc, 3630 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3631 .fill_link_info = bpf_tracing_link_fill_link_info, 3632 }; 3633 3634 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3635 int tgt_prog_fd, 3636 u32 btf_id, 3637 u64 bpf_cookie, 3638 enum bpf_attach_type attach_type) 3639 { 3640 struct bpf_link_primer link_primer; 3641 struct bpf_prog *tgt_prog = NULL; 3642 struct bpf_trampoline *tr = NULL; 3643 struct bpf_tracing_link *link; 3644 u64 key = 0; 3645 int err; 3646 3647 switch (prog->type) { 3648 case BPF_PROG_TYPE_TRACING: 3649 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3650 prog->expected_attach_type != BPF_TRACE_FEXIT && 3651 prog->expected_attach_type != BPF_TRACE_FSESSION && 3652 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3653 err = -EINVAL; 3654 goto out_put_prog; 3655 } 3656 break; 3657 case BPF_PROG_TYPE_EXT: 3658 if (prog->expected_attach_type != 0) { 3659 err = -EINVAL; 3660 goto out_put_prog; 3661 } 3662 break; 3663 case BPF_PROG_TYPE_LSM: 3664 if (prog->expected_attach_type != BPF_LSM_MAC) { 3665 err = -EINVAL; 3666 goto out_put_prog; 3667 } 3668 break; 3669 default: 3670 err = -EINVAL; 3671 goto out_put_prog; 3672 } 3673 3674 if (!!tgt_prog_fd != !!btf_id) { 3675 err = -EINVAL; 3676 goto out_put_prog; 3677 } 3678 3679 if (tgt_prog_fd) { 3680 /* 3681 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3682 * part would be changed to implement the same for 3683 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3684 * attach_tracing_prog flag is set. 3685 */ 3686 if (prog->type != BPF_PROG_TYPE_EXT) { 3687 err = -EINVAL; 3688 goto out_put_prog; 3689 } 3690 3691 tgt_prog = bpf_prog_get(tgt_prog_fd); 3692 if (IS_ERR(tgt_prog)) { 3693 err = PTR_ERR(tgt_prog); 3694 tgt_prog = NULL; 3695 goto out_put_prog; 3696 } 3697 3698 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3699 } 3700 3701 if (prog->expected_attach_type == BPF_TRACE_FSESSION) { 3702 struct bpf_fsession_link *fslink; 3703 3704 fslink = kzalloc_obj(*fslink, GFP_USER); 3705 if (fslink) { 3706 bpf_link_init(&fslink->fexit.link, BPF_LINK_TYPE_TRACING, 3707 &bpf_tracing_link_lops, prog, attach_type); 3708 fslink->fexit.cookie = bpf_cookie; 3709 link = &fslink->link; 3710 } else { 3711 link = NULL; 3712 } 3713 } else { 3714 link = kzalloc_obj(*link, GFP_USER); 3715 } 3716 if (!link) { 3717 err = -ENOMEM; 3718 goto out_put_prog; 3719 } 3720 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3721 &bpf_tracing_link_lops, prog, attach_type); 3722 3723 link->link.cookie = bpf_cookie; 3724 3725 mutex_lock(&prog->aux->dst_mutex); 3726 3727 /* There are a few possible cases here: 3728 * 3729 * - if prog->aux->dst_trampoline is set, the program was just loaded 3730 * and not yet attached to anything, so we can use the values stored 3731 * in prog->aux 3732 * 3733 * - if prog->aux->dst_trampoline is NULL, the program has already been 3734 * attached to a target and its initial target was cleared (below) 3735 * 3736 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3737 * target_btf_id using the link_create API. 3738 * 3739 * - if tgt_prog == NULL when this function was called using the old 3740 * raw_tracepoint_open API, and we need a target from prog->aux 3741 * 3742 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3743 * was detached and is going for re-attachment. 3744 * 3745 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3746 * are NULL, then program was already attached and user did not provide 3747 * tgt_prog_fd so we have no way to find out or create trampoline 3748 */ 3749 if (!prog->aux->dst_trampoline && !tgt_prog) { 3750 /* 3751 * Allow re-attach for TRACING and LSM programs. If it's 3752 * currently linked, bpf_trampoline_link_prog will fail. 3753 * EXT programs need to specify tgt_prog_fd, so they 3754 * re-attach in separate code path. 3755 */ 3756 if (prog->type != BPF_PROG_TYPE_TRACING && 3757 prog->type != BPF_PROG_TYPE_LSM) { 3758 err = -EINVAL; 3759 goto out_unlock; 3760 } 3761 /* We can allow re-attach only if we have valid attach_btf. */ 3762 if (!prog->aux->attach_btf) { 3763 err = -EINVAL; 3764 goto out_unlock; 3765 } 3766 btf_id = prog->aux->attach_btf_id; 3767 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3768 } 3769 3770 if (!prog->aux->dst_trampoline || 3771 (key && key != prog->aux->dst_trampoline->key)) { 3772 /* If there is no saved target, or the specified target is 3773 * different from the destination specified at load time, we 3774 * need a new trampoline and a check for compatibility 3775 */ 3776 struct bpf_attach_target_info tgt_info = {}; 3777 3778 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3779 &tgt_info); 3780 if (err) 3781 goto out_unlock; 3782 3783 if (tgt_info.tgt_mod) { 3784 module_put(prog->aux->mod); 3785 prog->aux->mod = tgt_info.tgt_mod; 3786 } 3787 3788 tr = bpf_trampoline_get(key, &tgt_info); 3789 if (!tr) { 3790 err = -ENOMEM; 3791 goto out_unlock; 3792 } 3793 } else { 3794 /* The caller didn't specify a target, or the target was the 3795 * same as the destination supplied during program load. This 3796 * means we can reuse the trampoline and reference from program 3797 * load time, and there is no need to allocate a new one. This 3798 * can only happen once for any program, as the saved values in 3799 * prog->aux are cleared below. 3800 */ 3801 tr = prog->aux->dst_trampoline; 3802 tgt_prog = prog->aux->dst_prog; 3803 } 3804 /* 3805 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true 3806 * freplace prog. Without this check, kprobe_write_ctx=true freplace 3807 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and 3808 * then modify the registers of the kprobe prog's target kernel 3809 * function. 3810 * 3811 * This also blocks the combination of uprobe+freplace, because it is 3812 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe 3813 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by 3814 * the target perf event flags in __perf_event_set_bpf_prog(). 3815 */ 3816 if (prog->type == BPF_PROG_TYPE_EXT && 3817 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) { 3818 err = -EINVAL; 3819 goto out_unlock; 3820 } 3821 3822 err = bpf_link_prime(&link->link.link, &link_primer); 3823 if (err) 3824 goto out_unlock; 3825 3826 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog); 3827 if (err) { 3828 bpf_link_cleanup(&link_primer); 3829 link = NULL; 3830 goto out_unlock; 3831 } 3832 3833 link->tgt_prog = tgt_prog; 3834 link->trampoline = tr; 3835 3836 /* Always clear the trampoline and target prog from prog->aux to make 3837 * sure the original attach destination is not kept alive after a 3838 * program is (re-)attached to another target. 3839 */ 3840 if (prog->aux->dst_prog && 3841 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3842 /* got extra prog ref from syscall, or attaching to different prog */ 3843 bpf_prog_put(prog->aux->dst_prog); 3844 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3845 /* we allocated a new trampoline, so free the old one */ 3846 bpf_trampoline_put(prog->aux->dst_trampoline); 3847 3848 prog->aux->dst_prog = NULL; 3849 prog->aux->dst_trampoline = NULL; 3850 mutex_unlock(&prog->aux->dst_mutex); 3851 3852 return bpf_link_settle(&link_primer); 3853 out_unlock: 3854 if (tr && tr != prog->aux->dst_trampoline) 3855 bpf_trampoline_put(tr); 3856 mutex_unlock(&prog->aux->dst_mutex); 3857 kfree(link); 3858 out_put_prog: 3859 if (tgt_prog_fd && tgt_prog) 3860 bpf_prog_put(tgt_prog); 3861 return err; 3862 } 3863 3864 static void bpf_raw_tp_link_release(struct bpf_link *link) 3865 { 3866 struct bpf_raw_tp_link *raw_tp = 3867 container_of(link, struct bpf_raw_tp_link, link); 3868 3869 bpf_probe_unregister(raw_tp->btp, raw_tp); 3870 bpf_put_raw_tracepoint(raw_tp->btp); 3871 } 3872 3873 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3874 { 3875 struct bpf_raw_tp_link *raw_tp = 3876 container_of(link, struct bpf_raw_tp_link, link); 3877 3878 kfree(raw_tp); 3879 } 3880 3881 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3882 struct seq_file *seq) 3883 { 3884 struct bpf_raw_tp_link *raw_tp_link = 3885 container_of(link, struct bpf_raw_tp_link, link); 3886 3887 seq_printf(seq, 3888 "tp_name:\t%s\n" 3889 "cookie:\t%llu\n", 3890 raw_tp_link->btp->tp->name, 3891 raw_tp_link->cookie); 3892 } 3893 3894 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3895 u32 len) 3896 { 3897 if (ulen >= len + 1) { 3898 if (copy_to_user(ubuf, buf, len + 1)) 3899 return -EFAULT; 3900 } else { 3901 char zero = '\0'; 3902 3903 if (copy_to_user(ubuf, buf, ulen - 1)) 3904 return -EFAULT; 3905 if (put_user(zero, ubuf + ulen - 1)) 3906 return -EFAULT; 3907 return -ENOSPC; 3908 } 3909 3910 return 0; 3911 } 3912 3913 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3914 struct bpf_link_info *info) 3915 { 3916 struct bpf_raw_tp_link *raw_tp_link = 3917 container_of(link, struct bpf_raw_tp_link, link); 3918 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3919 const char *tp_name = raw_tp_link->btp->tp->name; 3920 u32 ulen = info->raw_tracepoint.tp_name_len; 3921 size_t tp_len = strlen(tp_name); 3922 3923 if (!ulen ^ !ubuf) 3924 return -EINVAL; 3925 3926 info->raw_tracepoint.tp_name_len = tp_len + 1; 3927 info->raw_tracepoint.cookie = raw_tp_link->cookie; 3928 3929 if (!ubuf) 3930 return 0; 3931 3932 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3933 } 3934 3935 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3936 .release = bpf_raw_tp_link_release, 3937 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3938 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3939 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3940 }; 3941 3942 #ifdef CONFIG_PERF_EVENTS 3943 struct bpf_perf_link { 3944 struct bpf_link link; 3945 struct file *perf_file; 3946 }; 3947 3948 static void bpf_perf_link_release(struct bpf_link *link) 3949 { 3950 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3951 struct perf_event *event = perf_link->perf_file->private_data; 3952 3953 perf_event_free_bpf_prog(event); 3954 fput(perf_link->perf_file); 3955 } 3956 3957 static void bpf_perf_link_dealloc(struct bpf_link *link) 3958 { 3959 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3960 3961 kfree(perf_link); 3962 } 3963 3964 static int bpf_perf_link_fill_common(const struct perf_event *event, 3965 char __user *uname, u32 *ulenp, 3966 u64 *probe_offset, u64 *probe_addr, 3967 u32 *fd_type, unsigned long *missed) 3968 { 3969 const char *buf; 3970 u32 prog_id, ulen; 3971 size_t len; 3972 int err; 3973 3974 ulen = *ulenp; 3975 if (!ulen ^ !uname) 3976 return -EINVAL; 3977 3978 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3979 probe_offset, probe_addr, missed); 3980 if (err) 3981 return err; 3982 3983 if (buf) { 3984 len = strlen(buf); 3985 *ulenp = len + 1; 3986 } else { 3987 *ulenp = 1; 3988 } 3989 if (!uname) 3990 return 0; 3991 3992 if (buf) { 3993 err = bpf_copy_to_user(uname, buf, ulen, len); 3994 if (err) 3995 return err; 3996 } else { 3997 char zero = '\0'; 3998 3999 if (put_user(zero, uname)) 4000 return -EFAULT; 4001 } 4002 return 0; 4003 } 4004 4005 #ifdef CONFIG_KPROBE_EVENTS 4006 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 4007 struct bpf_link_info *info) 4008 { 4009 unsigned long missed; 4010 char __user *uname; 4011 u64 addr, offset; 4012 u32 ulen, type; 4013 int err; 4014 4015 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 4016 ulen = info->perf_event.kprobe.name_len; 4017 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 4018 &type, &missed); 4019 if (err) 4020 return err; 4021 if (type == BPF_FD_TYPE_KRETPROBE) 4022 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 4023 else 4024 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 4025 info->perf_event.kprobe.name_len = ulen; 4026 info->perf_event.kprobe.offset = offset; 4027 info->perf_event.kprobe.missed = missed; 4028 if (!kallsyms_show_value(current_cred())) 4029 addr = 0; 4030 info->perf_event.kprobe.addr = addr; 4031 info->perf_event.kprobe.cookie = event->bpf_cookie; 4032 return 0; 4033 } 4034 4035 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, 4036 struct seq_file *seq) 4037 { 4038 const char *name; 4039 int err; 4040 u32 prog_id, type; 4041 u64 offset, addr; 4042 unsigned long missed; 4043 4044 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4045 &offset, &addr, &missed); 4046 if (err) 4047 return; 4048 4049 seq_printf(seq, 4050 "name:\t%s\n" 4051 "offset:\t%#llx\n" 4052 "missed:\t%lu\n" 4053 "addr:\t%#llx\n" 4054 "event_type:\t%s\n" 4055 "cookie:\t%llu\n", 4056 name, offset, missed, addr, 4057 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", 4058 event->bpf_cookie); 4059 } 4060 #endif 4061 4062 #ifdef CONFIG_UPROBE_EVENTS 4063 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 4064 struct bpf_link_info *info) 4065 { 4066 u64 ref_ctr_offset, offset; 4067 char __user *uname; 4068 u32 ulen, type; 4069 int err; 4070 4071 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 4072 ulen = info->perf_event.uprobe.name_len; 4073 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, 4074 &type, NULL); 4075 if (err) 4076 return err; 4077 4078 if (type == BPF_FD_TYPE_URETPROBE) 4079 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 4080 else 4081 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 4082 info->perf_event.uprobe.name_len = ulen; 4083 info->perf_event.uprobe.offset = offset; 4084 info->perf_event.uprobe.cookie = event->bpf_cookie; 4085 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; 4086 return 0; 4087 } 4088 4089 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, 4090 struct seq_file *seq) 4091 { 4092 const char *name; 4093 int err; 4094 u32 prog_id, type; 4095 u64 offset, ref_ctr_offset; 4096 unsigned long missed; 4097 4098 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4099 &offset, &ref_ctr_offset, &missed); 4100 if (err) 4101 return; 4102 4103 seq_printf(seq, 4104 "name:\t%s\n" 4105 "offset:\t%#llx\n" 4106 "ref_ctr_offset:\t%#llx\n" 4107 "event_type:\t%s\n" 4108 "cookie:\t%llu\n", 4109 name, offset, ref_ctr_offset, 4110 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", 4111 event->bpf_cookie); 4112 } 4113 #endif 4114 4115 static int bpf_perf_link_fill_probe(const struct perf_event *event, 4116 struct bpf_link_info *info) 4117 { 4118 #ifdef CONFIG_KPROBE_EVENTS 4119 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4120 return bpf_perf_link_fill_kprobe(event, info); 4121 #endif 4122 #ifdef CONFIG_UPROBE_EVENTS 4123 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4124 return bpf_perf_link_fill_uprobe(event, info); 4125 #endif 4126 return -EOPNOTSUPP; 4127 } 4128 4129 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 4130 struct bpf_link_info *info) 4131 { 4132 char __user *uname; 4133 u32 ulen; 4134 int err; 4135 4136 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 4137 ulen = info->perf_event.tracepoint.name_len; 4138 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 4139 if (err) 4140 return err; 4141 4142 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 4143 info->perf_event.tracepoint.name_len = ulen; 4144 info->perf_event.tracepoint.cookie = event->bpf_cookie; 4145 return 0; 4146 } 4147 4148 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 4149 struct bpf_link_info *info) 4150 { 4151 info->perf_event.event.type = event->attr.type; 4152 info->perf_event.event.config = event->attr.config; 4153 info->perf_event.event.cookie = event->bpf_cookie; 4154 info->perf_event.type = BPF_PERF_EVENT_EVENT; 4155 return 0; 4156 } 4157 4158 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 4159 struct bpf_link_info *info) 4160 { 4161 struct bpf_perf_link *perf_link; 4162 const struct perf_event *event; 4163 4164 perf_link = container_of(link, struct bpf_perf_link, link); 4165 event = perf_get_event(perf_link->perf_file); 4166 if (IS_ERR(event)) 4167 return PTR_ERR(event); 4168 4169 switch (event->prog->type) { 4170 case BPF_PROG_TYPE_PERF_EVENT: 4171 return bpf_perf_link_fill_perf_event(event, info); 4172 case BPF_PROG_TYPE_TRACEPOINT: 4173 return bpf_perf_link_fill_tracepoint(event, info); 4174 case BPF_PROG_TYPE_KPROBE: 4175 return bpf_perf_link_fill_probe(event, info); 4176 default: 4177 return -EOPNOTSUPP; 4178 } 4179 } 4180 4181 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, 4182 struct seq_file *seq) 4183 { 4184 seq_printf(seq, 4185 "type:\t%u\n" 4186 "config:\t%llu\n" 4187 "event_type:\t%s\n" 4188 "cookie:\t%llu\n", 4189 event->attr.type, event->attr.config, 4190 "event", event->bpf_cookie); 4191 } 4192 4193 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, 4194 struct seq_file *seq) 4195 { 4196 int err; 4197 const char *name; 4198 u32 prog_id; 4199 4200 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, 4201 NULL, NULL); 4202 if (err) 4203 return; 4204 4205 seq_printf(seq, 4206 "tp_name:\t%s\n" 4207 "event_type:\t%s\n" 4208 "cookie:\t%llu\n", 4209 name, "tracepoint", event->bpf_cookie); 4210 } 4211 4212 static void bpf_probe_link_show_fdinfo(const struct perf_event *event, 4213 struct seq_file *seq) 4214 { 4215 #ifdef CONFIG_KPROBE_EVENTS 4216 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4217 return bpf_perf_link_fdinfo_kprobe(event, seq); 4218 #endif 4219 4220 #ifdef CONFIG_UPROBE_EVENTS 4221 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4222 return bpf_perf_link_fdinfo_uprobe(event, seq); 4223 #endif 4224 } 4225 4226 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, 4227 struct seq_file *seq) 4228 { 4229 struct bpf_perf_link *perf_link; 4230 const struct perf_event *event; 4231 4232 perf_link = container_of(link, struct bpf_perf_link, link); 4233 event = perf_get_event(perf_link->perf_file); 4234 if (IS_ERR(event)) 4235 return; 4236 4237 switch (event->prog->type) { 4238 case BPF_PROG_TYPE_PERF_EVENT: 4239 return bpf_perf_event_link_show_fdinfo(event, seq); 4240 case BPF_PROG_TYPE_TRACEPOINT: 4241 return bpf_tracepoint_link_show_fdinfo(event, seq); 4242 case BPF_PROG_TYPE_KPROBE: 4243 return bpf_probe_link_show_fdinfo(event, seq); 4244 default: 4245 return; 4246 } 4247 } 4248 4249 static const struct bpf_link_ops bpf_perf_link_lops = { 4250 .release = bpf_perf_link_release, 4251 .dealloc = bpf_perf_link_dealloc, 4252 .fill_link_info = bpf_perf_link_fill_link_info, 4253 .show_fdinfo = bpf_perf_link_show_fdinfo, 4254 }; 4255 4256 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4257 { 4258 struct bpf_link_primer link_primer; 4259 struct bpf_perf_link *link; 4260 struct perf_event *event; 4261 struct file *perf_file; 4262 int err; 4263 4264 if (attr->link_create.flags) 4265 return -EINVAL; 4266 4267 perf_file = perf_event_get(attr->link_create.target_fd); 4268 if (IS_ERR(perf_file)) 4269 return PTR_ERR(perf_file); 4270 4271 link = kzalloc_obj(*link, GFP_USER); 4272 if (!link) { 4273 err = -ENOMEM; 4274 goto out_put_file; 4275 } 4276 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, 4277 attr->link_create.attach_type); 4278 link->perf_file = perf_file; 4279 4280 err = bpf_link_prime(&link->link, &link_primer); 4281 if (err) { 4282 kfree(link); 4283 goto out_put_file; 4284 } 4285 4286 event = perf_file->private_data; 4287 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 4288 if (err) { 4289 bpf_link_cleanup(&link_primer); 4290 goto out_put_file; 4291 } 4292 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 4293 bpf_prog_inc(prog); 4294 4295 return bpf_link_settle(&link_primer); 4296 4297 out_put_file: 4298 fput(perf_file); 4299 return err; 4300 } 4301 #else 4302 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4303 { 4304 return -EOPNOTSUPP; 4305 } 4306 #endif /* CONFIG_PERF_EVENTS */ 4307 4308 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 4309 const char __user *user_tp_name, u64 cookie, 4310 enum bpf_attach_type attach_type) 4311 { 4312 struct bpf_link_primer link_primer; 4313 struct bpf_raw_tp_link *link; 4314 struct bpf_raw_event_map *btp; 4315 const char *tp_name; 4316 char buf[128]; 4317 int err; 4318 4319 switch (prog->type) { 4320 case BPF_PROG_TYPE_TRACING: 4321 case BPF_PROG_TYPE_EXT: 4322 case BPF_PROG_TYPE_LSM: 4323 if (user_tp_name) 4324 /* The attach point for this category of programs 4325 * should be specified via btf_id during program load. 4326 */ 4327 return -EINVAL; 4328 if (prog->type == BPF_PROG_TYPE_TRACING && 4329 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 4330 tp_name = prog->aux->attach_func_name; 4331 break; 4332 } 4333 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); 4334 case BPF_PROG_TYPE_RAW_TRACEPOINT: 4335 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 4336 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 4337 return -EFAULT; 4338 buf[sizeof(buf) - 1] = 0; 4339 tp_name = buf; 4340 break; 4341 default: 4342 return -EINVAL; 4343 } 4344 4345 btp = bpf_get_raw_tracepoint(tp_name); 4346 if (!btp) 4347 return -ENOENT; 4348 4349 if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) { 4350 bpf_put_raw_tracepoint(btp); 4351 return -EINVAL; 4352 } 4353 4354 link = kzalloc_obj(*link, GFP_USER); 4355 if (!link) { 4356 err = -ENOMEM; 4357 goto out_put_btp; 4358 } 4359 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 4360 &bpf_raw_tp_link_lops, prog, attach_type, 4361 tracepoint_is_faultable(btp->tp)); 4362 link->btp = btp; 4363 link->cookie = cookie; 4364 4365 err = bpf_link_prime(&link->link, &link_primer); 4366 if (err) { 4367 kfree(link); 4368 goto out_put_btp; 4369 } 4370 4371 err = bpf_probe_register(link->btp, link); 4372 if (err) { 4373 bpf_link_cleanup(&link_primer); 4374 goto out_put_btp; 4375 } 4376 4377 return bpf_link_settle(&link_primer); 4378 4379 out_put_btp: 4380 bpf_put_raw_tracepoint(btp); 4381 return err; 4382 } 4383 4384 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 4385 4386 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4387 { 4388 struct bpf_prog *prog; 4389 void __user *tp_name; 4390 __u64 cookie; 4391 int fd; 4392 4393 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4394 return -EINVAL; 4395 4396 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4397 if (IS_ERR(prog)) 4398 return PTR_ERR(prog); 4399 4400 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4401 cookie = attr->raw_tracepoint.cookie; 4402 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); 4403 if (fd < 0) 4404 bpf_prog_put(prog); 4405 return fd; 4406 } 4407 4408 static enum bpf_prog_type 4409 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4410 { 4411 switch (attach_type) { 4412 case BPF_CGROUP_INET_INGRESS: 4413 case BPF_CGROUP_INET_EGRESS: 4414 return BPF_PROG_TYPE_CGROUP_SKB; 4415 case BPF_CGROUP_INET_SOCK_CREATE: 4416 case BPF_CGROUP_INET_SOCK_RELEASE: 4417 case BPF_CGROUP_INET4_POST_BIND: 4418 case BPF_CGROUP_INET6_POST_BIND: 4419 return BPF_PROG_TYPE_CGROUP_SOCK; 4420 case BPF_CGROUP_INET4_BIND: 4421 case BPF_CGROUP_INET6_BIND: 4422 case BPF_CGROUP_INET4_CONNECT: 4423 case BPF_CGROUP_INET6_CONNECT: 4424 case BPF_CGROUP_UNIX_CONNECT: 4425 case BPF_CGROUP_INET4_GETPEERNAME: 4426 case BPF_CGROUP_INET6_GETPEERNAME: 4427 case BPF_CGROUP_UNIX_GETPEERNAME: 4428 case BPF_CGROUP_INET4_GETSOCKNAME: 4429 case BPF_CGROUP_INET6_GETSOCKNAME: 4430 case BPF_CGROUP_UNIX_GETSOCKNAME: 4431 case BPF_CGROUP_UDP4_SENDMSG: 4432 case BPF_CGROUP_UDP6_SENDMSG: 4433 case BPF_CGROUP_UNIX_SENDMSG: 4434 case BPF_CGROUP_UDP4_RECVMSG: 4435 case BPF_CGROUP_UDP6_RECVMSG: 4436 case BPF_CGROUP_UNIX_RECVMSG: 4437 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4438 case BPF_CGROUP_SOCK_OPS: 4439 return BPF_PROG_TYPE_SOCK_OPS; 4440 case BPF_CGROUP_DEVICE: 4441 return BPF_PROG_TYPE_CGROUP_DEVICE; 4442 case BPF_SK_MSG_VERDICT: 4443 return BPF_PROG_TYPE_SK_MSG; 4444 case BPF_SK_SKB_STREAM_PARSER: 4445 case BPF_SK_SKB_STREAM_VERDICT: 4446 case BPF_SK_SKB_VERDICT: 4447 return BPF_PROG_TYPE_SK_SKB; 4448 case BPF_LIRC_MODE2: 4449 return BPF_PROG_TYPE_LIRC_MODE2; 4450 case BPF_FLOW_DISSECTOR: 4451 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4452 case BPF_CGROUP_SYSCTL: 4453 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4454 case BPF_CGROUP_GETSOCKOPT: 4455 case BPF_CGROUP_SETSOCKOPT: 4456 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4457 case BPF_TRACE_ITER: 4458 case BPF_TRACE_RAW_TP: 4459 case BPF_TRACE_FENTRY: 4460 case BPF_TRACE_FEXIT: 4461 case BPF_TRACE_FSESSION: 4462 case BPF_MODIFY_RETURN: 4463 return BPF_PROG_TYPE_TRACING; 4464 case BPF_LSM_MAC: 4465 return BPF_PROG_TYPE_LSM; 4466 case BPF_SK_LOOKUP: 4467 return BPF_PROG_TYPE_SK_LOOKUP; 4468 case BPF_XDP: 4469 return BPF_PROG_TYPE_XDP; 4470 case BPF_LSM_CGROUP: 4471 return BPF_PROG_TYPE_LSM; 4472 case BPF_TCX_INGRESS: 4473 case BPF_TCX_EGRESS: 4474 case BPF_NETKIT_PRIMARY: 4475 case BPF_NETKIT_PEER: 4476 return BPF_PROG_TYPE_SCHED_CLS; 4477 default: 4478 return BPF_PROG_TYPE_UNSPEC; 4479 } 4480 } 4481 4482 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4483 enum bpf_attach_type attach_type) 4484 { 4485 enum bpf_prog_type ptype; 4486 4487 switch (prog->type) { 4488 case BPF_PROG_TYPE_CGROUP_SOCK: 4489 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4490 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4491 case BPF_PROG_TYPE_SK_LOOKUP: 4492 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4493 case BPF_PROG_TYPE_CGROUP_SKB: 4494 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4495 /* cg-skb progs can be loaded by unpriv user. 4496 * check permissions at attach time. 4497 */ 4498 return -EPERM; 4499 4500 ptype = attach_type_to_prog_type(attach_type); 4501 if (prog->type != ptype) 4502 return -EINVAL; 4503 4504 return prog->enforce_expected_attach_type && 4505 prog->expected_attach_type != attach_type ? 4506 -EINVAL : 0; 4507 case BPF_PROG_TYPE_EXT: 4508 return 0; 4509 case BPF_PROG_TYPE_NETFILTER: 4510 if (attach_type != BPF_NETFILTER) 4511 return -EINVAL; 4512 return 0; 4513 case BPF_PROG_TYPE_PERF_EVENT: 4514 case BPF_PROG_TYPE_TRACEPOINT: 4515 if (attach_type != BPF_PERF_EVENT) 4516 return -EINVAL; 4517 return 0; 4518 case BPF_PROG_TYPE_KPROBE: 4519 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4520 attach_type != BPF_TRACE_KPROBE_MULTI) 4521 return -EINVAL; 4522 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4523 attach_type != BPF_TRACE_KPROBE_SESSION) 4524 return -EINVAL; 4525 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4526 attach_type != BPF_TRACE_UPROBE_MULTI) 4527 return -EINVAL; 4528 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4529 attach_type != BPF_TRACE_UPROBE_SESSION) 4530 return -EINVAL; 4531 if (attach_type != BPF_PERF_EVENT && 4532 attach_type != BPF_TRACE_KPROBE_MULTI && 4533 attach_type != BPF_TRACE_KPROBE_SESSION && 4534 attach_type != BPF_TRACE_UPROBE_MULTI && 4535 attach_type != BPF_TRACE_UPROBE_SESSION) 4536 return -EINVAL; 4537 return 0; 4538 case BPF_PROG_TYPE_SCHED_CLS: 4539 if (attach_type != BPF_TCX_INGRESS && 4540 attach_type != BPF_TCX_EGRESS && 4541 attach_type != BPF_NETKIT_PRIMARY && 4542 attach_type != BPF_NETKIT_PEER) 4543 return -EINVAL; 4544 return 0; 4545 default: 4546 ptype = attach_type_to_prog_type(attach_type); 4547 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4548 return -EINVAL; 4549 return 0; 4550 } 4551 } 4552 4553 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, 4554 bool check_atype) 4555 { 4556 switch (ptype) { 4557 case BPF_PROG_TYPE_CGROUP_DEVICE: 4558 case BPF_PROG_TYPE_CGROUP_SKB: 4559 case BPF_PROG_TYPE_CGROUP_SOCK: 4560 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4561 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4562 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4563 case BPF_PROG_TYPE_SOCK_OPS: 4564 return true; 4565 case BPF_PROG_TYPE_LSM: 4566 return check_atype ? atype == BPF_LSM_CGROUP : true; 4567 default: 4568 return false; 4569 } 4570 } 4571 4572 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4573 4574 #define BPF_F_ATTACH_MASK_BASE \ 4575 (BPF_F_ALLOW_OVERRIDE | \ 4576 BPF_F_ALLOW_MULTI | \ 4577 BPF_F_REPLACE | \ 4578 BPF_F_PREORDER) 4579 4580 #define BPF_F_ATTACH_MASK_MPROG \ 4581 (BPF_F_REPLACE | \ 4582 BPF_F_BEFORE | \ 4583 BPF_F_AFTER | \ 4584 BPF_F_ID | \ 4585 BPF_F_LINK) 4586 4587 static int bpf_prog_attach(const union bpf_attr *attr) 4588 { 4589 enum bpf_prog_type ptype; 4590 struct bpf_prog *prog; 4591 int ret; 4592 4593 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4594 return -EINVAL; 4595 4596 ptype = attach_type_to_prog_type(attr->attach_type); 4597 if (ptype == BPF_PROG_TYPE_UNSPEC) 4598 return -EINVAL; 4599 if (bpf_mprog_supported(ptype)) { 4600 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4601 return -EINVAL; 4602 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4603 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) 4604 return -EINVAL; 4605 } else { 4606 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4607 return -EINVAL; 4608 if (attr->relative_fd || 4609 attr->expected_revision) 4610 return -EINVAL; 4611 } 4612 4613 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4614 if (IS_ERR(prog)) 4615 return PTR_ERR(prog); 4616 4617 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4618 bpf_prog_put(prog); 4619 return -EINVAL; 4620 } 4621 4622 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { 4623 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4624 goto out; 4625 } 4626 4627 switch (ptype) { 4628 case BPF_PROG_TYPE_SK_SKB: 4629 case BPF_PROG_TYPE_SK_MSG: 4630 ret = sock_map_get_from_fd(attr, prog); 4631 break; 4632 case BPF_PROG_TYPE_LIRC_MODE2: 4633 ret = lirc_prog_attach(attr, prog); 4634 break; 4635 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4636 ret = netns_bpf_prog_attach(attr, prog); 4637 break; 4638 case BPF_PROG_TYPE_SCHED_CLS: 4639 if (attr->attach_type == BPF_TCX_INGRESS || 4640 attr->attach_type == BPF_TCX_EGRESS) 4641 ret = tcx_prog_attach(attr, prog); 4642 else 4643 ret = netkit_prog_attach(attr, prog); 4644 break; 4645 default: 4646 ret = -EINVAL; 4647 } 4648 out: 4649 if (ret) 4650 bpf_prog_put(prog); 4651 return ret; 4652 } 4653 4654 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4655 4656 static int bpf_prog_detach(const union bpf_attr *attr) 4657 { 4658 struct bpf_prog *prog = NULL; 4659 enum bpf_prog_type ptype; 4660 int ret; 4661 4662 if (CHECK_ATTR(BPF_PROG_DETACH)) 4663 return -EINVAL; 4664 4665 ptype = attach_type_to_prog_type(attr->attach_type); 4666 if (bpf_mprog_supported(ptype)) { 4667 if (ptype == BPF_PROG_TYPE_UNSPEC) 4668 return -EINVAL; 4669 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4670 return -EINVAL; 4671 if (attr->attach_bpf_fd) { 4672 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4673 if (IS_ERR(prog)) 4674 return PTR_ERR(prog); 4675 } else if (!bpf_mprog_detach_empty(ptype)) { 4676 return -EPERM; 4677 } 4678 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4679 if (attr->attach_flags || attr->relative_fd) 4680 return -EINVAL; 4681 } else if (attr->attach_flags || 4682 attr->relative_fd || 4683 attr->expected_revision) { 4684 return -EINVAL; 4685 } 4686 4687 switch (ptype) { 4688 case BPF_PROG_TYPE_SK_MSG: 4689 case BPF_PROG_TYPE_SK_SKB: 4690 ret = sock_map_prog_detach(attr, ptype); 4691 break; 4692 case BPF_PROG_TYPE_LIRC_MODE2: 4693 ret = lirc_prog_detach(attr); 4694 break; 4695 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4696 ret = netns_bpf_prog_detach(attr, ptype); 4697 break; 4698 case BPF_PROG_TYPE_CGROUP_DEVICE: 4699 case BPF_PROG_TYPE_CGROUP_SKB: 4700 case BPF_PROG_TYPE_CGROUP_SOCK: 4701 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4702 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4703 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4704 case BPF_PROG_TYPE_SOCK_OPS: 4705 case BPF_PROG_TYPE_LSM: 4706 ret = cgroup_bpf_prog_detach(attr, ptype); 4707 break; 4708 case BPF_PROG_TYPE_SCHED_CLS: 4709 if (attr->attach_type == BPF_TCX_INGRESS || 4710 attr->attach_type == BPF_TCX_EGRESS) 4711 ret = tcx_prog_detach(attr, prog); 4712 else 4713 ret = netkit_prog_detach(attr, prog); 4714 break; 4715 default: 4716 ret = -EINVAL; 4717 } 4718 4719 if (prog) 4720 bpf_prog_put(prog); 4721 return ret; 4722 } 4723 4724 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4725 4726 static int bpf_prog_query(const union bpf_attr *attr, 4727 union bpf_attr __user *uattr, u32 uattr_size) 4728 { 4729 if (!bpf_net_capable()) 4730 return -EPERM; 4731 if (CHECK_ATTR(BPF_PROG_QUERY)) 4732 return -EINVAL; 4733 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4734 return -EINVAL; 4735 4736 switch (attr->query.attach_type) { 4737 case BPF_CGROUP_INET_INGRESS: 4738 case BPF_CGROUP_INET_EGRESS: 4739 case BPF_CGROUP_INET_SOCK_CREATE: 4740 case BPF_CGROUP_INET_SOCK_RELEASE: 4741 case BPF_CGROUP_INET4_BIND: 4742 case BPF_CGROUP_INET6_BIND: 4743 case BPF_CGROUP_INET4_POST_BIND: 4744 case BPF_CGROUP_INET6_POST_BIND: 4745 case BPF_CGROUP_INET4_CONNECT: 4746 case BPF_CGROUP_INET6_CONNECT: 4747 case BPF_CGROUP_UNIX_CONNECT: 4748 case BPF_CGROUP_INET4_GETPEERNAME: 4749 case BPF_CGROUP_INET6_GETPEERNAME: 4750 case BPF_CGROUP_UNIX_GETPEERNAME: 4751 case BPF_CGROUP_INET4_GETSOCKNAME: 4752 case BPF_CGROUP_INET6_GETSOCKNAME: 4753 case BPF_CGROUP_UNIX_GETSOCKNAME: 4754 case BPF_CGROUP_UDP4_SENDMSG: 4755 case BPF_CGROUP_UDP6_SENDMSG: 4756 case BPF_CGROUP_UNIX_SENDMSG: 4757 case BPF_CGROUP_UDP4_RECVMSG: 4758 case BPF_CGROUP_UDP6_RECVMSG: 4759 case BPF_CGROUP_UNIX_RECVMSG: 4760 case BPF_CGROUP_SOCK_OPS: 4761 case BPF_CGROUP_DEVICE: 4762 case BPF_CGROUP_SYSCTL: 4763 case BPF_CGROUP_GETSOCKOPT: 4764 case BPF_CGROUP_SETSOCKOPT: 4765 case BPF_LSM_CGROUP: 4766 return cgroup_bpf_prog_query(attr, uattr, uattr_size); 4767 case BPF_LIRC_MODE2: 4768 return lirc_prog_query(attr, uattr); 4769 case BPF_FLOW_DISSECTOR: 4770 case BPF_SK_LOOKUP: 4771 return netns_bpf_prog_query(attr, uattr); 4772 case BPF_SK_SKB_STREAM_PARSER: 4773 case BPF_SK_SKB_STREAM_VERDICT: 4774 case BPF_SK_MSG_VERDICT: 4775 case BPF_SK_SKB_VERDICT: 4776 return sock_map_bpf_prog_query(attr, uattr); 4777 case BPF_TCX_INGRESS: 4778 case BPF_TCX_EGRESS: 4779 return tcx_prog_query(attr, uattr); 4780 case BPF_NETKIT_PRIMARY: 4781 case BPF_NETKIT_PEER: 4782 return netkit_prog_query(attr, uattr); 4783 default: 4784 return -EINVAL; 4785 } 4786 } 4787 4788 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4789 4790 static int bpf_prog_test_run(const union bpf_attr *attr, 4791 union bpf_attr __user *uattr) 4792 { 4793 struct bpf_prog *prog; 4794 int ret = -ENOTSUPP; 4795 4796 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4797 return -EINVAL; 4798 4799 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4800 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4801 return -EINVAL; 4802 4803 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4804 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4805 return -EINVAL; 4806 4807 prog = bpf_prog_get(attr->test.prog_fd); 4808 if (IS_ERR(prog)) 4809 return PTR_ERR(prog); 4810 4811 if (prog->aux->ops->test_run) 4812 ret = prog->aux->ops->test_run(prog, attr, uattr); 4813 4814 bpf_prog_put(prog); 4815 return ret; 4816 } 4817 4818 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4819 4820 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4821 union bpf_attr __user *uattr, 4822 struct idr *idr, 4823 spinlock_t *lock) 4824 { 4825 u32 next_id = attr->start_id; 4826 int err = 0; 4827 4828 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4829 return -EINVAL; 4830 4831 if (!capable(CAP_SYS_ADMIN)) 4832 return -EPERM; 4833 4834 next_id++; 4835 spin_lock_bh(lock); 4836 if (!idr_get_next(idr, &next_id)) 4837 err = -ENOENT; 4838 spin_unlock_bh(lock); 4839 4840 if (!err) 4841 err = put_user(next_id, &uattr->next_id); 4842 4843 return err; 4844 } 4845 4846 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4847 { 4848 struct bpf_map *map; 4849 4850 spin_lock_bh(&map_idr_lock); 4851 again: 4852 map = idr_get_next(&map_idr, id); 4853 if (map) { 4854 map = __bpf_map_inc_not_zero(map, false); 4855 if (IS_ERR(map)) { 4856 (*id)++; 4857 goto again; 4858 } 4859 } 4860 spin_unlock_bh(&map_idr_lock); 4861 4862 return map; 4863 } 4864 4865 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4866 { 4867 struct bpf_prog *prog; 4868 4869 spin_lock_bh(&prog_idr_lock); 4870 again: 4871 prog = idr_get_next(&prog_idr, id); 4872 if (prog) { 4873 prog = bpf_prog_inc_not_zero(prog); 4874 if (IS_ERR(prog)) { 4875 (*id)++; 4876 goto again; 4877 } 4878 } 4879 spin_unlock_bh(&prog_idr_lock); 4880 4881 return prog; 4882 } 4883 4884 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4885 4886 struct bpf_prog *bpf_prog_by_id(u32 id) 4887 { 4888 struct bpf_prog *prog; 4889 4890 if (!id) 4891 return ERR_PTR(-ENOENT); 4892 4893 spin_lock_bh(&prog_idr_lock); 4894 prog = idr_find(&prog_idr, id); 4895 if (prog) 4896 prog = bpf_prog_inc_not_zero(prog); 4897 else 4898 prog = ERR_PTR(-ENOENT); 4899 spin_unlock_bh(&prog_idr_lock); 4900 return prog; 4901 } 4902 4903 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4904 { 4905 struct bpf_prog *prog; 4906 u32 id = attr->prog_id; 4907 int fd; 4908 4909 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4910 return -EINVAL; 4911 4912 if (!capable(CAP_SYS_ADMIN)) 4913 return -EPERM; 4914 4915 prog = bpf_prog_by_id(id); 4916 if (IS_ERR(prog)) 4917 return PTR_ERR(prog); 4918 4919 fd = bpf_prog_new_fd(prog); 4920 if (fd < 0) 4921 bpf_prog_put(prog); 4922 4923 return fd; 4924 } 4925 4926 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4927 4928 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4929 { 4930 struct bpf_map *map; 4931 u32 id = attr->map_id; 4932 int f_flags; 4933 int fd; 4934 4935 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4936 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4937 return -EINVAL; 4938 4939 if (!capable(CAP_SYS_ADMIN)) 4940 return -EPERM; 4941 4942 f_flags = bpf_get_file_flag(attr->open_flags); 4943 if (f_flags < 0) 4944 return f_flags; 4945 4946 spin_lock_bh(&map_idr_lock); 4947 map = idr_find(&map_idr, id); 4948 if (map) 4949 map = __bpf_map_inc_not_zero(map, true); 4950 else 4951 map = ERR_PTR(-ENOENT); 4952 spin_unlock_bh(&map_idr_lock); 4953 4954 if (IS_ERR(map)) 4955 return PTR_ERR(map); 4956 4957 fd = bpf_map_new_fd(map, f_flags); 4958 if (fd < 0) 4959 bpf_map_put_with_uref(map); 4960 4961 return fd; 4962 } 4963 4964 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4965 unsigned long addr, u32 *off, 4966 u32 *type) 4967 { 4968 const struct bpf_map *map; 4969 int i; 4970 4971 mutex_lock(&prog->aux->used_maps_mutex); 4972 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4973 map = prog->aux->used_maps[i]; 4974 if (map == (void *)addr) { 4975 *type = BPF_PSEUDO_MAP_FD; 4976 goto out; 4977 } 4978 if (!map->ops->map_direct_value_meta) 4979 continue; 4980 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4981 *type = BPF_PSEUDO_MAP_VALUE; 4982 goto out; 4983 } 4984 } 4985 map = NULL; 4986 4987 out: 4988 mutex_unlock(&prog->aux->used_maps_mutex); 4989 return map; 4990 } 4991 4992 static void prepare_dump_pseudo_call(struct bpf_insn *insn) 4993 { 4994 s32 call_off = insn->imm; 4995 4996 /* 4997 * BPF_CALL_ARGS only exists for interpreter fallback. 4998 * 1. For interpreter (BPF_CALL_ARGS): insn->off is the index of 4999 * interpreters_args array, so here using bpf_call_args_imm() 5000 * to get the real address offset. 5001 * 2. For JIT (BPF_CALL): insn->off is the subprog id. 5002 */ 5003 if (insn->code == (BPF_JMP | BPF_CALL_ARGS)) 5004 insn->imm = bpf_call_args_imm(insn->off); 5005 else 5006 insn->imm = insn->off; 5007 5008 /* Avoid dumping a truncated and misleading pc-relative offset. */ 5009 if (call_off > S16_MAX || call_off < S16_MIN) 5010 insn->off = 0; 5011 else 5012 insn->off = call_off; 5013 } 5014 5015 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 5016 const struct cred *f_cred) 5017 { 5018 const struct bpf_map *map; 5019 struct bpf_insn *insns; 5020 u32 off, type; 5021 u64 imm; 5022 u8 code; 5023 int i; 5024 5025 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 5026 GFP_USER); 5027 if (!insns) 5028 return insns; 5029 5030 for (i = 0; i < prog->len; i++) { 5031 code = insns[i].code; 5032 5033 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 5034 insns[i].code = BPF_JMP | BPF_CALL; 5035 insns[i].imm = BPF_FUNC_tail_call; 5036 /* fall-through */ 5037 } 5038 if (code == (BPF_JMP | BPF_CALL) || 5039 code == (BPF_JMP | BPF_CALL_ARGS)) { 5040 /* Restore the legacy xlated dump layout. */ 5041 if (insns[i].src_reg == BPF_PSEUDO_CALL) 5042 prepare_dump_pseudo_call(&insns[i]); 5043 if (code == (BPF_JMP | BPF_CALL_ARGS)) 5044 insns[i].code = BPF_JMP | BPF_CALL; 5045 if (!bpf_dump_raw_ok(f_cred)) 5046 insns[i].imm = 0; 5047 continue; 5048 } 5049 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 5050 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 5051 continue; 5052 } 5053 5054 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 5055 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 5056 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 5057 continue; 5058 } 5059 5060 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 5061 continue; 5062 5063 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 5064 map = bpf_map_from_imm(prog, imm, &off, &type); 5065 if (map) { 5066 insns[i].src_reg = type; 5067 insns[i].imm = map->id; 5068 insns[i + 1].imm = off; 5069 continue; 5070 } 5071 } 5072 5073 return insns; 5074 } 5075 5076 static int set_info_rec_size(struct bpf_prog_info *info) 5077 { 5078 /* 5079 * Ensure info.*_rec_size is the same as kernel expected size 5080 * 5081 * or 5082 * 5083 * Only allow zero *_rec_size if both _rec_size and _cnt are 5084 * zero. In this case, the kernel will set the expected 5085 * _rec_size back to the info. 5086 */ 5087 5088 if ((info->nr_func_info || info->func_info_rec_size) && 5089 info->func_info_rec_size != sizeof(struct bpf_func_info)) 5090 return -EINVAL; 5091 5092 if ((info->nr_line_info || info->line_info_rec_size) && 5093 info->line_info_rec_size != sizeof(struct bpf_line_info)) 5094 return -EINVAL; 5095 5096 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 5097 info->jited_line_info_rec_size != sizeof(__u64)) 5098 return -EINVAL; 5099 5100 info->func_info_rec_size = sizeof(struct bpf_func_info); 5101 info->line_info_rec_size = sizeof(struct bpf_line_info); 5102 info->jited_line_info_rec_size = sizeof(__u64); 5103 5104 return 0; 5105 } 5106 5107 static int bpf_prog_get_info_by_fd(struct file *file, 5108 struct bpf_prog *prog, 5109 const union bpf_attr *attr, 5110 union bpf_attr __user *uattr) 5111 { 5112 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5113 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 5114 struct bpf_prog_info info; 5115 u32 info_len = attr->info.info_len; 5116 struct bpf_prog_kstats stats; 5117 char __user *uinsns; 5118 u32 ulen; 5119 int err; 5120 5121 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5122 if (err) 5123 return err; 5124 info_len = min_t(u32, sizeof(info), info_len); 5125 5126 memset(&info, 0, sizeof(info)); 5127 if (copy_from_user(&info, uinfo, info_len)) 5128 return -EFAULT; 5129 5130 info.type = prog->type; 5131 info.id = prog->aux->id; 5132 info.load_time = prog->aux->load_time; 5133 info.created_by_uid = from_kuid_munged(current_user_ns(), 5134 prog->aux->user->uid); 5135 info.gpl_compatible = prog->gpl_compatible; 5136 5137 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 5138 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 5139 5140 mutex_lock(&prog->aux->used_maps_mutex); 5141 ulen = info.nr_map_ids; 5142 info.nr_map_ids = prog->aux->used_map_cnt; 5143 ulen = min_t(u32, info.nr_map_ids, ulen); 5144 if (ulen) { 5145 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 5146 u32 i; 5147 5148 for (i = 0; i < ulen; i++) 5149 if (put_user(prog->aux->used_maps[i]->id, 5150 &user_map_ids[i])) { 5151 mutex_unlock(&prog->aux->used_maps_mutex); 5152 return -EFAULT; 5153 } 5154 } 5155 mutex_unlock(&prog->aux->used_maps_mutex); 5156 5157 err = set_info_rec_size(&info); 5158 if (err) 5159 return err; 5160 5161 bpf_prog_get_stats(prog, &stats); 5162 info.run_time_ns = stats.nsecs; 5163 info.run_cnt = stats.cnt; 5164 info.recursion_misses = stats.misses; 5165 5166 info.verified_insns = prog->aux->verified_insns; 5167 if (prog->aux->btf) 5168 info.btf_id = btf_obj_id(prog->aux->btf); 5169 5170 if (!bpf_capable()) { 5171 info.jited_prog_len = 0; 5172 info.xlated_prog_len = 0; 5173 info.nr_jited_ksyms = 0; 5174 info.nr_jited_func_lens = 0; 5175 info.nr_func_info = 0; 5176 info.nr_line_info = 0; 5177 info.nr_jited_line_info = 0; 5178 goto done; 5179 } 5180 5181 ulen = info.xlated_prog_len; 5182 info.xlated_prog_len = bpf_prog_insn_size(prog); 5183 if (info.xlated_prog_len && ulen) { 5184 struct bpf_insn *insns_sanitized; 5185 bool fault; 5186 5187 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) { 5188 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 5189 if (!insns_sanitized) 5190 return -ENOMEM; 5191 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 5192 ulen = min_t(u32, info.xlated_prog_len, ulen); 5193 fault = copy_to_user(uinsns, insns_sanitized, ulen); 5194 kfree(insns_sanitized); 5195 if (fault) 5196 return -EFAULT; 5197 } else { 5198 info.xlated_prog_insns = 0; 5199 } 5200 } 5201 5202 if (bpf_prog_is_offloaded(prog->aux)) { 5203 err = bpf_prog_offload_info_fill(&info, prog); 5204 if (err) 5205 return err; 5206 goto done; 5207 } 5208 5209 /* NOTE: the following code is supposed to be skipped for offload. 5210 * bpf_prog_offload_info_fill() is the place to fill similar fields 5211 * for offload. 5212 */ 5213 ulen = info.jited_prog_len; 5214 if (prog->aux->func_cnt) { 5215 u32 i; 5216 5217 info.jited_prog_len = 0; 5218 for (i = 0; i < prog->aux->func_cnt; i++) 5219 info.jited_prog_len += prog->aux->func[i]->jited_len; 5220 } else { 5221 info.jited_prog_len = prog->jited_len; 5222 } 5223 5224 if (info.jited_prog_len && ulen) { 5225 if (bpf_dump_raw_ok(file->f_cred)) { 5226 uinsns = u64_to_user_ptr(info.jited_prog_insns); 5227 ulen = min_t(u32, info.jited_prog_len, ulen); 5228 5229 /* for multi-function programs, copy the JITed 5230 * instructions for all the functions 5231 */ 5232 if (prog->aux->func_cnt) { 5233 u32 len, free, i; 5234 u8 *img; 5235 5236 free = ulen; 5237 for (i = 0; i < prog->aux->func_cnt; i++) { 5238 len = prog->aux->func[i]->jited_len; 5239 len = min_t(u32, len, free); 5240 img = (u8 *) prog->aux->func[i]->bpf_func; 5241 if (copy_to_user(uinsns, img, len)) 5242 return -EFAULT; 5243 uinsns += len; 5244 free -= len; 5245 if (!free) 5246 break; 5247 } 5248 } else { 5249 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 5250 return -EFAULT; 5251 } 5252 } else { 5253 info.jited_prog_insns = 0; 5254 } 5255 } 5256 5257 ulen = info.nr_jited_ksyms; 5258 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 5259 if (ulen) { 5260 if (bpf_dump_raw_ok(file->f_cred)) { 5261 unsigned long ksym_addr; 5262 u64 __user *user_ksyms; 5263 u32 i; 5264 5265 /* copy the address of the kernel symbol 5266 * corresponding to each function 5267 */ 5268 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 5269 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 5270 if (prog->aux->func_cnt) { 5271 for (i = 0; i < ulen; i++) { 5272 ksym_addr = (unsigned long) 5273 prog->aux->func[i]->bpf_func; 5274 if (put_user((u64) ksym_addr, 5275 &user_ksyms[i])) 5276 return -EFAULT; 5277 } 5278 } else { 5279 ksym_addr = (unsigned long) prog->bpf_func; 5280 if (put_user((u64) ksym_addr, &user_ksyms[0])) 5281 return -EFAULT; 5282 } 5283 } else { 5284 info.jited_ksyms = 0; 5285 } 5286 } 5287 5288 ulen = info.nr_jited_func_lens; 5289 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 5290 if (ulen) { 5291 if (bpf_dump_raw_ok(file->f_cred)) { 5292 u32 __user *user_lens; 5293 u32 func_len, i; 5294 5295 /* copy the JITed image lengths for each function */ 5296 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 5297 user_lens = u64_to_user_ptr(info.jited_func_lens); 5298 if (prog->aux->func_cnt) { 5299 for (i = 0; i < ulen; i++) { 5300 func_len = 5301 prog->aux->func[i]->jited_len; 5302 if (put_user(func_len, &user_lens[i])) 5303 return -EFAULT; 5304 } 5305 } else { 5306 func_len = prog->jited_len; 5307 if (put_user(func_len, &user_lens[0])) 5308 return -EFAULT; 5309 } 5310 } else { 5311 info.jited_func_lens = 0; 5312 } 5313 } 5314 5315 info.attach_btf_id = prog->aux->attach_btf_id; 5316 if (attach_btf) 5317 info.attach_btf_obj_id = btf_obj_id(attach_btf); 5318 5319 ulen = info.nr_func_info; 5320 info.nr_func_info = prog->aux->func_info_cnt; 5321 if (info.nr_func_info && ulen) { 5322 char __user *user_finfo; 5323 5324 user_finfo = u64_to_user_ptr(info.func_info); 5325 ulen = min_t(u32, info.nr_func_info, ulen); 5326 if (copy_to_user(user_finfo, prog->aux->func_info, 5327 info.func_info_rec_size * ulen)) 5328 return -EFAULT; 5329 } 5330 5331 ulen = info.nr_line_info; 5332 info.nr_line_info = prog->aux->nr_linfo; 5333 if (info.nr_line_info && ulen) { 5334 __u8 __user *user_linfo; 5335 5336 user_linfo = u64_to_user_ptr(info.line_info); 5337 ulen = min_t(u32, info.nr_line_info, ulen); 5338 if (copy_to_user(user_linfo, prog->aux->linfo, 5339 info.line_info_rec_size * ulen)) 5340 return -EFAULT; 5341 } 5342 5343 ulen = info.nr_jited_line_info; 5344 if (prog->aux->jited_linfo) 5345 info.nr_jited_line_info = prog->aux->nr_linfo; 5346 else 5347 info.nr_jited_line_info = 0; 5348 if (info.nr_jited_line_info && ulen) { 5349 if (bpf_dump_raw_ok(file->f_cred)) { 5350 unsigned long line_addr; 5351 __u64 __user *user_linfo; 5352 u32 i; 5353 5354 user_linfo = u64_to_user_ptr(info.jited_line_info); 5355 ulen = min_t(u32, info.nr_jited_line_info, ulen); 5356 for (i = 0; i < ulen; i++) { 5357 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 5358 if (put_user((__u64)line_addr, &user_linfo[i])) 5359 return -EFAULT; 5360 } 5361 } else { 5362 info.jited_line_info = 0; 5363 } 5364 } 5365 5366 ulen = info.nr_prog_tags; 5367 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 5368 if (ulen) { 5369 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 5370 u32 i; 5371 5372 user_prog_tags = u64_to_user_ptr(info.prog_tags); 5373 ulen = min_t(u32, info.nr_prog_tags, ulen); 5374 if (prog->aux->func_cnt) { 5375 for (i = 0; i < ulen; i++) { 5376 if (copy_to_user(user_prog_tags[i], 5377 prog->aux->func[i]->tag, 5378 BPF_TAG_SIZE)) 5379 return -EFAULT; 5380 } 5381 } else { 5382 if (copy_to_user(user_prog_tags[0], 5383 prog->tag, BPF_TAG_SIZE)) 5384 return -EFAULT; 5385 } 5386 } 5387 5388 done: 5389 if (copy_to_user(uinfo, &info, info_len) || 5390 put_user(info_len, &uattr->info.info_len)) 5391 return -EFAULT; 5392 5393 return 0; 5394 } 5395 5396 static int bpf_map_get_info_by_fd(struct file *file, 5397 struct bpf_map *map, 5398 const union bpf_attr *attr, 5399 union bpf_attr __user *uattr) 5400 { 5401 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5402 struct bpf_map_info info; 5403 u32 info_len = attr->info.info_len; 5404 int err; 5405 5406 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5407 if (err) 5408 return err; 5409 info_len = min_t(u32, sizeof(info), info_len); 5410 5411 memset(&info, 0, sizeof(info)); 5412 if (copy_from_user(&info, uinfo, info_len)) 5413 return -EFAULT; 5414 5415 info.type = map->map_type; 5416 info.id = map->id; 5417 info.key_size = map->key_size; 5418 info.value_size = map->value_size; 5419 info.max_entries = map->max_entries; 5420 info.map_flags = map->map_flags; 5421 info.map_extra = map->map_extra; 5422 memcpy(info.name, map->name, sizeof(map->name)); 5423 5424 if (map->btf) { 5425 info.btf_id = btf_obj_id(map->btf); 5426 info.btf_key_type_id = map->btf_key_type_id; 5427 info.btf_value_type_id = map->btf_value_type_id; 5428 } 5429 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 5430 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 5431 bpf_map_struct_ops_info_fill(&info, map); 5432 5433 if (bpf_map_is_offloaded(map)) { 5434 err = bpf_map_offload_info_fill(&info, map); 5435 if (err) 5436 return err; 5437 } 5438 5439 if (info.hash) { 5440 char __user *uhash = u64_to_user_ptr(info.hash); 5441 5442 if (!map->ops->map_get_hash) 5443 return -EINVAL; 5444 if (info.hash_size != sizeof(map->sha)) 5445 return -EINVAL; 5446 if (!READ_ONCE(map->frozen)) 5447 return -EPERM; 5448 5449 err = map->ops->map_get_hash(map); 5450 if (err != 0) 5451 return err; 5452 5453 if (copy_to_user(uhash, map->sha, sizeof(map->sha)) != 0) 5454 return -EFAULT; 5455 } else if (info.hash_size) { 5456 return -EINVAL; 5457 } 5458 5459 if (copy_to_user(uinfo, &info, info_len) || 5460 put_user(info_len, &uattr->info.info_len)) 5461 return -EFAULT; 5462 5463 return 0; 5464 } 5465 5466 static int bpf_btf_get_info_by_fd(struct file *file, 5467 struct btf *btf, 5468 const union bpf_attr *attr, 5469 union bpf_attr __user *uattr) 5470 { 5471 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5472 u32 info_len = attr->info.info_len; 5473 int err; 5474 5475 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5476 if (err) 5477 return err; 5478 5479 return btf_get_info_by_fd(btf, attr, uattr); 5480 } 5481 5482 static int bpf_link_get_info_by_fd(struct file *file, 5483 struct bpf_link *link, 5484 const union bpf_attr *attr, 5485 union bpf_attr __user *uattr) 5486 { 5487 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5488 struct bpf_link_info info; 5489 u32 info_len = attr->info.info_len; 5490 int err; 5491 5492 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5493 if (err) 5494 return err; 5495 info_len = min_t(u32, sizeof(info), info_len); 5496 5497 memset(&info, 0, sizeof(info)); 5498 if (copy_from_user(&info, uinfo, info_len)) 5499 return -EFAULT; 5500 5501 info.type = link->type; 5502 info.id = link->id; 5503 if (link->prog) 5504 info.prog_id = link->prog->aux->id; 5505 5506 if (link->ops->fill_link_info) { 5507 err = link->ops->fill_link_info(link, &info); 5508 if (err) 5509 return err; 5510 } 5511 5512 if (copy_to_user(uinfo, &info, info_len) || 5513 put_user(info_len, &uattr->info.info_len)) 5514 return -EFAULT; 5515 5516 return 0; 5517 } 5518 5519 5520 static int token_get_info_by_fd(struct file *file, 5521 struct bpf_token *token, 5522 const union bpf_attr *attr, 5523 union bpf_attr __user *uattr) 5524 { 5525 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5526 u32 info_len = attr->info.info_len; 5527 int err; 5528 5529 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5530 if (err) 5531 return err; 5532 return bpf_token_get_info_by_fd(token, attr, uattr); 5533 } 5534 5535 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5536 5537 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5538 union bpf_attr __user *uattr) 5539 { 5540 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5541 return -EINVAL; 5542 5543 CLASS(fd, f)(attr->info.bpf_fd); 5544 if (fd_empty(f)) 5545 return -EBADFD; 5546 5547 if (fd_file(f)->f_op == &bpf_prog_fops) 5548 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5549 uattr); 5550 else if (fd_file(f)->f_op == &bpf_map_fops) 5551 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5552 uattr); 5553 else if (fd_file(f)->f_op == &btf_fops) 5554 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5555 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5556 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5557 attr, uattr); 5558 else if (fd_file(f)->f_op == &bpf_token_fops) 5559 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5560 attr, uattr); 5561 return -EINVAL; 5562 } 5563 5564 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5565 5566 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 5567 { 5568 struct bpf_token *token = NULL; 5569 5570 if (CHECK_ATTR(BPF_BTF_LOAD)) 5571 return -EINVAL; 5572 5573 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5574 return -EINVAL; 5575 5576 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5577 token = bpf_token_get_from_fd(attr->btf_token_fd); 5578 if (IS_ERR(token)) 5579 return PTR_ERR(token); 5580 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5581 bpf_token_put(token); 5582 token = NULL; 5583 } 5584 } 5585 5586 if (!bpf_token_capable(token, CAP_BPF)) { 5587 bpf_token_put(token); 5588 return -EPERM; 5589 } 5590 5591 bpf_token_put(token); 5592 5593 return btf_new_fd(attr, uattr, attr_log); 5594 } 5595 5596 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd 5597 5598 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5599 { 5600 struct bpf_token *token = NULL; 5601 5602 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5603 return -EINVAL; 5604 5605 if (attr->open_flags & ~BPF_F_TOKEN_FD) 5606 return -EINVAL; 5607 5608 if (attr->open_flags & BPF_F_TOKEN_FD) { 5609 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); 5610 if (IS_ERR(token)) 5611 return PTR_ERR(token); 5612 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { 5613 bpf_token_put(token); 5614 token = NULL; 5615 } 5616 } 5617 5618 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { 5619 bpf_token_put(token); 5620 return -EPERM; 5621 } 5622 5623 bpf_token_put(token); 5624 5625 return btf_get_fd_by_id(attr->btf_id); 5626 } 5627 5628 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5629 union bpf_attr __user *uattr, 5630 u32 prog_id, u32 fd_type, 5631 const char *buf, u64 probe_offset, 5632 u64 probe_addr) 5633 { 5634 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5635 u32 len = buf ? strlen(buf) : 0, input_len; 5636 int err = 0; 5637 5638 if (put_user(len, &uattr->task_fd_query.buf_len)) 5639 return -EFAULT; 5640 input_len = attr->task_fd_query.buf_len; 5641 if (input_len && ubuf) { 5642 if (!len) { 5643 /* nothing to copy, just make ubuf NULL terminated */ 5644 char zero = '\0'; 5645 5646 if (put_user(zero, ubuf)) 5647 return -EFAULT; 5648 } else { 5649 err = bpf_copy_to_user(ubuf, buf, input_len, len); 5650 if (err == -EFAULT) 5651 return err; 5652 } 5653 } 5654 5655 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5656 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5657 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5658 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5659 return -EFAULT; 5660 5661 return err; 5662 } 5663 5664 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5665 5666 static int bpf_task_fd_query(const union bpf_attr *attr, 5667 union bpf_attr __user *uattr) 5668 { 5669 pid_t pid = attr->task_fd_query.pid; 5670 u32 fd = attr->task_fd_query.fd; 5671 const struct perf_event *event; 5672 struct task_struct *task; 5673 struct file *file; 5674 int err; 5675 5676 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5677 return -EINVAL; 5678 5679 if (!capable(CAP_SYS_ADMIN)) 5680 return -EPERM; 5681 5682 if (attr->task_fd_query.flags != 0) 5683 return -EINVAL; 5684 5685 rcu_read_lock(); 5686 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5687 rcu_read_unlock(); 5688 if (!task) 5689 return -ENOENT; 5690 5691 err = 0; 5692 file = fget_task(task, fd); 5693 put_task_struct(task); 5694 if (!file) 5695 return -EBADF; 5696 5697 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5698 struct bpf_link *link = file->private_data; 5699 5700 if (link->ops == &bpf_raw_tp_link_lops) { 5701 struct bpf_raw_tp_link *raw_tp = 5702 container_of(link, struct bpf_raw_tp_link, link); 5703 struct bpf_raw_event_map *btp = raw_tp->btp; 5704 5705 err = bpf_task_fd_query_copy(attr, uattr, 5706 raw_tp->link.prog->aux->id, 5707 BPF_FD_TYPE_RAW_TRACEPOINT, 5708 btp->tp->name, 0, 0); 5709 goto put_file; 5710 } 5711 goto out_not_supp; 5712 } 5713 5714 event = perf_get_event(file); 5715 if (!IS_ERR(event)) { 5716 u64 probe_offset, probe_addr; 5717 u32 prog_id, fd_type; 5718 const char *buf; 5719 5720 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5721 &buf, &probe_offset, 5722 &probe_addr, NULL); 5723 if (!err) 5724 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5725 fd_type, buf, 5726 probe_offset, 5727 probe_addr); 5728 goto put_file; 5729 } 5730 5731 out_not_supp: 5732 err = -ENOTSUPP; 5733 put_file: 5734 fput(file); 5735 return err; 5736 } 5737 5738 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5739 5740 #define BPF_DO_BATCH(fn, ...) \ 5741 do { \ 5742 if (!fn) { \ 5743 err = -ENOTSUPP; \ 5744 goto err_put; \ 5745 } \ 5746 err = fn(__VA_ARGS__); \ 5747 } while (0) 5748 5749 static int bpf_map_do_batch(const union bpf_attr *attr, 5750 union bpf_attr __user *uattr, 5751 int cmd) 5752 { 5753 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5754 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5755 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5756 struct bpf_map *map; 5757 int err; 5758 5759 if (CHECK_ATTR(BPF_MAP_BATCH)) 5760 return -EINVAL; 5761 5762 CLASS(fd, f)(attr->batch.map_fd); 5763 5764 map = __bpf_map_get(f); 5765 if (IS_ERR(map)) 5766 return PTR_ERR(map); 5767 if (has_write) 5768 bpf_map_write_active_inc(map); 5769 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5770 err = -EPERM; 5771 goto err_put; 5772 } 5773 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5774 err = -EPERM; 5775 goto err_put; 5776 } 5777 5778 if (cmd == BPF_MAP_LOOKUP_BATCH) 5779 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5780 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5781 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5782 else if (cmd == BPF_MAP_UPDATE_BATCH) 5783 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5784 else 5785 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5786 err_put: 5787 if (has_write) { 5788 maybe_wait_bpf_programs(map); 5789 bpf_map_write_active_dec(map); 5790 } 5791 return err; 5792 } 5793 5794 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 5795 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5796 { 5797 struct bpf_prog *prog; 5798 int ret; 5799 5800 if (CHECK_ATTR(BPF_LINK_CREATE)) 5801 return -EINVAL; 5802 5803 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5804 return bpf_struct_ops_link_create(attr); 5805 5806 prog = bpf_prog_get(attr->link_create.prog_fd); 5807 if (IS_ERR(prog)) 5808 return PTR_ERR(prog); 5809 5810 ret = bpf_prog_attach_check_attach_type(prog, 5811 attr->link_create.attach_type); 5812 if (ret) 5813 goto out; 5814 5815 switch (prog->type) { 5816 case BPF_PROG_TYPE_CGROUP_SKB: 5817 case BPF_PROG_TYPE_CGROUP_SOCK: 5818 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5819 case BPF_PROG_TYPE_SOCK_OPS: 5820 case BPF_PROG_TYPE_CGROUP_DEVICE: 5821 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5822 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5823 ret = cgroup_bpf_link_attach(attr, prog); 5824 break; 5825 case BPF_PROG_TYPE_EXT: 5826 ret = bpf_tracing_prog_attach(prog, 5827 attr->link_create.target_fd, 5828 attr->link_create.target_btf_id, 5829 attr->link_create.tracing.cookie, 5830 attr->link_create.attach_type); 5831 break; 5832 case BPF_PROG_TYPE_LSM: 5833 case BPF_PROG_TYPE_TRACING: 5834 if (attr->link_create.attach_type != prog->expected_attach_type) { 5835 ret = -EINVAL; 5836 goto out; 5837 } 5838 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5839 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, 5840 attr->link_create.attach_type); 5841 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5842 ret = bpf_iter_link_attach(attr, uattr, prog); 5843 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5844 ret = cgroup_bpf_link_attach(attr, prog); 5845 else 5846 ret = bpf_tracing_prog_attach(prog, 5847 attr->link_create.target_fd, 5848 attr->link_create.target_btf_id, 5849 attr->link_create.tracing.cookie, 5850 attr->link_create.attach_type); 5851 break; 5852 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5853 case BPF_PROG_TYPE_SK_LOOKUP: 5854 ret = netns_bpf_link_create(attr, prog); 5855 break; 5856 case BPF_PROG_TYPE_SK_MSG: 5857 case BPF_PROG_TYPE_SK_SKB: 5858 ret = sock_map_link_create(attr, prog); 5859 break; 5860 #ifdef CONFIG_NET 5861 case BPF_PROG_TYPE_XDP: 5862 ret = bpf_xdp_link_attach(attr, prog); 5863 break; 5864 case BPF_PROG_TYPE_SCHED_CLS: 5865 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5866 attr->link_create.attach_type == BPF_TCX_EGRESS) 5867 ret = tcx_link_attach(attr, prog); 5868 else 5869 ret = netkit_link_attach(attr, prog); 5870 break; 5871 case BPF_PROG_TYPE_NETFILTER: 5872 ret = bpf_nf_link_attach(attr, prog); 5873 break; 5874 #endif 5875 case BPF_PROG_TYPE_PERF_EVENT: 5876 case BPF_PROG_TYPE_TRACEPOINT: 5877 ret = bpf_perf_link_attach(attr, prog); 5878 break; 5879 case BPF_PROG_TYPE_KPROBE: 5880 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5881 ret = bpf_perf_link_attach(attr, prog); 5882 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5883 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5884 ret = bpf_kprobe_multi_link_attach(attr, prog); 5885 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5886 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5887 ret = bpf_uprobe_multi_link_attach(attr, prog); 5888 break; 5889 default: 5890 ret = -EINVAL; 5891 } 5892 5893 out: 5894 if (ret < 0) 5895 bpf_prog_put(prog); 5896 return ret; 5897 } 5898 5899 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5900 { 5901 struct bpf_map *new_map, *old_map = NULL; 5902 int ret; 5903 5904 new_map = bpf_map_get(attr->link_update.new_map_fd); 5905 if (IS_ERR(new_map)) 5906 return PTR_ERR(new_map); 5907 5908 if (attr->link_update.flags & BPF_F_REPLACE) { 5909 old_map = bpf_map_get(attr->link_update.old_map_fd); 5910 if (IS_ERR(old_map)) { 5911 ret = PTR_ERR(old_map); 5912 goto out_put; 5913 } 5914 } else if (attr->link_update.old_map_fd) { 5915 ret = -EINVAL; 5916 goto out_put; 5917 } 5918 5919 ret = link->ops->update_map(link, new_map, old_map); 5920 5921 if (old_map) 5922 bpf_map_put(old_map); 5923 out_put: 5924 bpf_map_put(new_map); 5925 return ret; 5926 } 5927 5928 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5929 5930 static int link_update(union bpf_attr *attr) 5931 { 5932 struct bpf_prog *old_prog = NULL, *new_prog; 5933 struct bpf_link *link; 5934 u32 flags; 5935 int ret; 5936 5937 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5938 return -EINVAL; 5939 5940 flags = attr->link_update.flags; 5941 if (flags & ~BPF_F_REPLACE) 5942 return -EINVAL; 5943 5944 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5945 if (IS_ERR(link)) 5946 return PTR_ERR(link); 5947 5948 if (link->ops->update_map) { 5949 ret = link_update_map(link, attr); 5950 goto out_put_link; 5951 } 5952 5953 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5954 if (IS_ERR(new_prog)) { 5955 ret = PTR_ERR(new_prog); 5956 goto out_put_link; 5957 } 5958 5959 if (flags & BPF_F_REPLACE) { 5960 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5961 if (IS_ERR(old_prog)) { 5962 ret = PTR_ERR(old_prog); 5963 old_prog = NULL; 5964 goto out_put_progs; 5965 } 5966 } else if (attr->link_update.old_prog_fd) { 5967 ret = -EINVAL; 5968 goto out_put_progs; 5969 } 5970 5971 if (link->ops->update_prog) 5972 ret = link->ops->update_prog(link, new_prog, old_prog); 5973 else 5974 ret = -EINVAL; 5975 5976 out_put_progs: 5977 if (old_prog) 5978 bpf_prog_put(old_prog); 5979 if (ret) 5980 bpf_prog_put(new_prog); 5981 out_put_link: 5982 bpf_link_put_direct(link); 5983 return ret; 5984 } 5985 5986 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5987 5988 static int link_detach(union bpf_attr *attr) 5989 { 5990 struct bpf_link *link; 5991 int ret; 5992 5993 if (CHECK_ATTR(BPF_LINK_DETACH)) 5994 return -EINVAL; 5995 5996 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 5997 if (IS_ERR(link)) 5998 return PTR_ERR(link); 5999 6000 if (link->ops->detach) 6001 ret = link->ops->detach(link); 6002 else 6003 ret = -EOPNOTSUPP; 6004 6005 bpf_link_put_direct(link); 6006 return ret; 6007 } 6008 6009 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 6010 { 6011 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 6012 } 6013 EXPORT_SYMBOL(bpf_link_inc_not_zero); 6014 6015 struct bpf_link *bpf_link_by_id(u32 id) 6016 { 6017 struct bpf_link *link; 6018 6019 if (!id) 6020 return ERR_PTR(-ENOENT); 6021 6022 spin_lock_bh(&link_idr_lock); 6023 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 6024 link = idr_find(&link_idr, id); 6025 if (link) { 6026 if (link->id) 6027 link = bpf_link_inc_not_zero(link); 6028 else 6029 link = ERR_PTR(-EAGAIN); 6030 } else { 6031 link = ERR_PTR(-ENOENT); 6032 } 6033 spin_unlock_bh(&link_idr_lock); 6034 return link; 6035 } 6036 6037 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 6038 { 6039 struct bpf_link *link; 6040 6041 spin_lock_bh(&link_idr_lock); 6042 again: 6043 link = idr_get_next(&link_idr, id); 6044 if (link) { 6045 link = bpf_link_inc_not_zero(link); 6046 if (IS_ERR(link)) { 6047 (*id)++; 6048 goto again; 6049 } 6050 } 6051 spin_unlock_bh(&link_idr_lock); 6052 6053 return link; 6054 } 6055 6056 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 6057 6058 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 6059 { 6060 struct bpf_link *link; 6061 u32 id = attr->link_id; 6062 int fd; 6063 6064 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 6065 return -EINVAL; 6066 6067 if (!capable(CAP_SYS_ADMIN)) 6068 return -EPERM; 6069 6070 link = bpf_link_by_id(id); 6071 if (IS_ERR(link)) 6072 return PTR_ERR(link); 6073 6074 fd = bpf_link_new_fd(link); 6075 if (fd < 0) 6076 bpf_link_put_direct(link); 6077 6078 return fd; 6079 } 6080 6081 DEFINE_MUTEX(bpf_stats_enabled_mutex); 6082 6083 static int bpf_stats_release(struct inode *inode, struct file *file) 6084 { 6085 mutex_lock(&bpf_stats_enabled_mutex); 6086 static_key_slow_dec(&bpf_stats_enabled_key.key); 6087 mutex_unlock(&bpf_stats_enabled_mutex); 6088 return 0; 6089 } 6090 6091 static const struct file_operations bpf_stats_fops = { 6092 .release = bpf_stats_release, 6093 }; 6094 6095 static int bpf_enable_runtime_stats(void) 6096 { 6097 int fd; 6098 6099 mutex_lock(&bpf_stats_enabled_mutex); 6100 6101 /* Set a very high limit to avoid overflow */ 6102 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 6103 mutex_unlock(&bpf_stats_enabled_mutex); 6104 return -EBUSY; 6105 } 6106 6107 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 6108 if (fd >= 0) 6109 static_key_slow_inc(&bpf_stats_enabled_key.key); 6110 6111 mutex_unlock(&bpf_stats_enabled_mutex); 6112 return fd; 6113 } 6114 6115 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 6116 6117 static int bpf_enable_stats(union bpf_attr *attr) 6118 { 6119 6120 if (CHECK_ATTR(BPF_ENABLE_STATS)) 6121 return -EINVAL; 6122 6123 if (!capable(CAP_SYS_ADMIN)) 6124 return -EPERM; 6125 6126 switch (attr->enable_stats.type) { 6127 case BPF_STATS_RUN_TIME: 6128 return bpf_enable_runtime_stats(); 6129 default: 6130 break; 6131 } 6132 return -EINVAL; 6133 } 6134 6135 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 6136 6137 static int bpf_iter_create(union bpf_attr *attr) 6138 { 6139 struct bpf_link *link; 6140 int err; 6141 6142 if (CHECK_ATTR(BPF_ITER_CREATE)) 6143 return -EINVAL; 6144 6145 if (attr->iter_create.flags) 6146 return -EINVAL; 6147 6148 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 6149 if (IS_ERR(link)) 6150 return PTR_ERR(link); 6151 6152 err = bpf_iter_new_fd(link); 6153 bpf_link_put_direct(link); 6154 6155 return err; 6156 } 6157 6158 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 6159 6160 static int bpf_prog_bind_map(union bpf_attr *attr) 6161 { 6162 struct bpf_prog *prog; 6163 struct bpf_map *map; 6164 struct bpf_map **used_maps_old, **used_maps_new; 6165 int i, ret = 0; 6166 6167 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 6168 return -EINVAL; 6169 6170 if (attr->prog_bind_map.flags) 6171 return -EINVAL; 6172 6173 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 6174 if (IS_ERR(prog)) 6175 return PTR_ERR(prog); 6176 6177 map = bpf_map_get(attr->prog_bind_map.map_fd); 6178 if (IS_ERR(map)) { 6179 ret = PTR_ERR(map); 6180 goto out_prog_put; 6181 } 6182 6183 mutex_lock(&prog->aux->used_maps_mutex); 6184 6185 used_maps_old = prog->aux->used_maps; 6186 6187 for (i = 0; i < prog->aux->used_map_cnt; i++) 6188 if (used_maps_old[i] == map) { 6189 bpf_map_put(map); 6190 goto out_unlock; 6191 } 6192 6193 used_maps_new = kmalloc_objs(used_maps_new[0], 6194 prog->aux->used_map_cnt + 1); 6195 if (!used_maps_new) { 6196 ret = -ENOMEM; 6197 goto out_unlock; 6198 } 6199 6200 /* The bpf program will not access the bpf map, but for the sake of 6201 * simplicity, increase sleepable_refcnt for sleepable program as well. 6202 */ 6203 if (prog->sleepable) 6204 atomic64_inc(&map->sleepable_refcnt); 6205 memcpy(used_maps_new, used_maps_old, 6206 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 6207 used_maps_new[prog->aux->used_map_cnt] = map; 6208 6209 prog->aux->used_map_cnt++; 6210 prog->aux->used_maps = used_maps_new; 6211 6212 kfree(used_maps_old); 6213 6214 out_unlock: 6215 mutex_unlock(&prog->aux->used_maps_mutex); 6216 6217 if (ret) 6218 bpf_map_put(map); 6219 out_prog_put: 6220 bpf_prog_put(prog); 6221 return ret; 6222 } 6223 6224 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 6225 6226 static int token_create(union bpf_attr *attr) 6227 { 6228 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 6229 return -EINVAL; 6230 6231 /* no flags are supported yet */ 6232 if (attr->token_create.flags) 6233 return -EINVAL; 6234 6235 return bpf_token_create(attr); 6236 } 6237 6238 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd 6239 6240 static int prog_stream_read(union bpf_attr *attr) 6241 { 6242 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); 6243 u32 len = attr->prog_stream_read.stream_buf_len; 6244 struct bpf_prog *prog; 6245 int ret; 6246 6247 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) 6248 return -EINVAL; 6249 6250 prog = bpf_prog_get(attr->prog_stream_read.prog_fd); 6251 if (IS_ERR(prog)) 6252 return PTR_ERR(prog); 6253 6254 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); 6255 bpf_prog_put(prog); 6256 6257 return ret; 6258 } 6259 6260 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.prog_fd 6261 6262 static int prog_assoc_struct_ops(union bpf_attr *attr) 6263 { 6264 struct bpf_prog *prog; 6265 struct bpf_map *map; 6266 int ret; 6267 6268 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS)) 6269 return -EINVAL; 6270 6271 if (attr->prog_assoc_struct_ops.flags) 6272 return -EINVAL; 6273 6274 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd); 6275 if (IS_ERR(prog)) 6276 return PTR_ERR(prog); 6277 6278 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) { 6279 ret = -EINVAL; 6280 goto put_prog; 6281 } 6282 6283 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd); 6284 if (IS_ERR(map)) { 6285 ret = PTR_ERR(map); 6286 goto put_prog; 6287 } 6288 6289 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 6290 ret = -EINVAL; 6291 goto put_map; 6292 } 6293 6294 ret = bpf_prog_assoc_struct_ops(prog, map); 6295 6296 put_map: 6297 bpf_map_put(map); 6298 put_prog: 6299 bpf_prog_put(prog); 6300 return ret; 6301 } 6302 6303 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, 6304 bpfptr_t uattr_common, unsigned int size_common) 6305 { 6306 struct bpf_common_attr attr_common; 6307 u32 offsetof_log_true_size = 0; 6308 struct bpf_log_attr attr_log; 6309 union bpf_attr attr; 6310 int err; 6311 6312 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 6313 if (err) 6314 return err; 6315 size = min_t(u32, size, sizeof(attr)); 6316 6317 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 6318 memset(&attr, 0, sizeof(attr)); 6319 if (copy_from_bpfptr(&attr, uattr, size) != 0) 6320 return -EFAULT; 6321 6322 memset(&attr_common, 0, sizeof(attr_common)); 6323 if (cmd & BPF_COMMON_ATTRS) { 6324 err = bpf_check_uarg_tail_zero(uattr_common, 6325 offsetofend(struct bpf_common_attr, log_true_size), 6326 size_common); 6327 if (err) 6328 return err; 6329 6330 cmd &= ~BPF_COMMON_ATTRS; 6331 size_common = min_t(u32, size_common, sizeof(attr_common)); 6332 if (copy_from_bpfptr(&attr_common, uattr_common, size_common) != 0) 6333 return -EFAULT; 6334 } else { 6335 size_common = 0; 6336 } 6337 6338 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 6339 if (err < 0) 6340 return err; 6341 6342 switch (cmd) { 6343 case BPF_MAP_CREATE: 6344 err = map_create(&attr, uattr, &attr_common, uattr_common, size_common); 6345 break; 6346 case BPF_MAP_LOOKUP_ELEM: 6347 err = map_lookup_elem(&attr); 6348 break; 6349 case BPF_MAP_UPDATE_ELEM: 6350 err = map_update_elem(&attr, uattr); 6351 break; 6352 case BPF_MAP_DELETE_ELEM: 6353 err = map_delete_elem(&attr, uattr); 6354 break; 6355 case BPF_MAP_GET_NEXT_KEY: 6356 err = map_get_next_key(&attr); 6357 break; 6358 case BPF_MAP_FREEZE: 6359 err = map_freeze(&attr); 6360 break; 6361 case BPF_PROG_LOAD: 6362 if (size >= offsetofend(union bpf_attr, log_true_size)) 6363 offsetof_log_true_size = offsetof(union bpf_attr, log_true_size); 6364 err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level, 6365 offsetof_log_true_size, uattr, &attr_common, uattr_common, 6366 size_common); 6367 err = err ?: bpf_prog_load(&attr, uattr, &attr_log); 6368 break; 6369 case BPF_OBJ_PIN: 6370 err = bpf_obj_pin(&attr); 6371 break; 6372 case BPF_OBJ_GET: 6373 err = bpf_obj_get(&attr); 6374 break; 6375 case BPF_PROG_ATTACH: 6376 err = bpf_prog_attach(&attr); 6377 break; 6378 case BPF_PROG_DETACH: 6379 err = bpf_prog_detach(&attr); 6380 break; 6381 case BPF_PROG_QUERY: 6382 err = bpf_prog_query(&attr, uattr.user, size); 6383 break; 6384 case BPF_PROG_TEST_RUN: 6385 err = bpf_prog_test_run(&attr, uattr.user); 6386 break; 6387 case BPF_PROG_GET_NEXT_ID: 6388 err = bpf_obj_get_next_id(&attr, uattr.user, 6389 &prog_idr, &prog_idr_lock); 6390 break; 6391 case BPF_MAP_GET_NEXT_ID: 6392 err = bpf_obj_get_next_id(&attr, uattr.user, 6393 &map_idr, &map_idr_lock); 6394 break; 6395 case BPF_BTF_GET_NEXT_ID: 6396 err = bpf_obj_get_next_id(&attr, uattr.user, 6397 &btf_idr, &btf_idr_lock); 6398 break; 6399 case BPF_PROG_GET_FD_BY_ID: 6400 err = bpf_prog_get_fd_by_id(&attr); 6401 break; 6402 case BPF_MAP_GET_FD_BY_ID: 6403 err = bpf_map_get_fd_by_id(&attr); 6404 break; 6405 case BPF_OBJ_GET_INFO_BY_FD: 6406 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 6407 break; 6408 case BPF_RAW_TRACEPOINT_OPEN: 6409 err = bpf_raw_tracepoint_open(&attr); 6410 break; 6411 case BPF_BTF_LOAD: 6412 if (size >= offsetofend(union bpf_attr, btf_log_true_size)) 6413 offsetof_log_true_size = offsetof(union bpf_attr, btf_log_true_size); 6414 err = bpf_log_attr_init(&attr_log, attr.btf_log_buf, attr.btf_log_size, 6415 attr.btf_log_level, offsetof_log_true_size, uattr, 6416 &attr_common, uattr_common, size_common); 6417 err = err ?: bpf_btf_load(&attr, uattr, &attr_log); 6418 break; 6419 case BPF_BTF_GET_FD_BY_ID: 6420 err = bpf_btf_get_fd_by_id(&attr); 6421 break; 6422 case BPF_TASK_FD_QUERY: 6423 err = bpf_task_fd_query(&attr, uattr.user); 6424 break; 6425 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 6426 err = map_lookup_and_delete_elem(&attr); 6427 break; 6428 case BPF_MAP_LOOKUP_BATCH: 6429 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 6430 break; 6431 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 6432 err = bpf_map_do_batch(&attr, uattr.user, 6433 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 6434 break; 6435 case BPF_MAP_UPDATE_BATCH: 6436 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 6437 break; 6438 case BPF_MAP_DELETE_BATCH: 6439 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 6440 break; 6441 case BPF_LINK_CREATE: 6442 err = link_create(&attr, uattr); 6443 break; 6444 case BPF_LINK_UPDATE: 6445 err = link_update(&attr); 6446 break; 6447 case BPF_LINK_GET_FD_BY_ID: 6448 err = bpf_link_get_fd_by_id(&attr); 6449 break; 6450 case BPF_LINK_GET_NEXT_ID: 6451 err = bpf_obj_get_next_id(&attr, uattr.user, 6452 &link_idr, &link_idr_lock); 6453 break; 6454 case BPF_ENABLE_STATS: 6455 err = bpf_enable_stats(&attr); 6456 break; 6457 case BPF_ITER_CREATE: 6458 err = bpf_iter_create(&attr); 6459 break; 6460 case BPF_LINK_DETACH: 6461 err = link_detach(&attr); 6462 break; 6463 case BPF_PROG_BIND_MAP: 6464 err = bpf_prog_bind_map(&attr); 6465 break; 6466 case BPF_TOKEN_CREATE: 6467 err = token_create(&attr); 6468 break; 6469 case BPF_PROG_STREAM_READ_BY_FD: 6470 err = prog_stream_read(&attr); 6471 break; 6472 case BPF_PROG_ASSOC_STRUCT_OPS: 6473 err = prog_assoc_struct_ops(&attr); 6474 break; 6475 default: 6476 err = -EINVAL; 6477 break; 6478 } 6479 6480 return err; 6481 } 6482 6483 SYSCALL_DEFINE5(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size, 6484 struct bpf_common_attr __user *, uattr_common, unsigned int, size_common) 6485 { 6486 return __sys_bpf(cmd, USER_BPFPTR(uattr), size, USER_BPFPTR(uattr_common), size_common); 6487 } 6488 6489 static bool syscall_prog_is_valid_access(int off, int size, 6490 enum bpf_access_type type, 6491 const struct bpf_prog *prog, 6492 struct bpf_insn_access_aux *info) 6493 { 6494 if (off < 0 || off >= U16_MAX) 6495 return false; 6496 /* No alignment requirements for syscall ctx accesses. */ 6497 return true; 6498 } 6499 6500 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 6501 { 6502 switch (cmd) { 6503 case BPF_MAP_CREATE: 6504 case BPF_MAP_DELETE_ELEM: 6505 case BPF_MAP_UPDATE_ELEM: 6506 case BPF_MAP_FREEZE: 6507 case BPF_MAP_GET_FD_BY_ID: 6508 case BPF_PROG_LOAD: 6509 case BPF_BTF_LOAD: 6510 case BPF_LINK_CREATE: 6511 case BPF_RAW_TRACEPOINT_OPEN: 6512 break; 6513 default: 6514 return -EINVAL; 6515 } 6516 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size, KERNEL_BPFPTR(NULL), 0); 6517 } 6518 6519 6520 /* To shut up -Wmissing-prototypes. 6521 * This function is used by the kernel light skeleton 6522 * to load bpf programs when modules are loaded or during kernel boot. 6523 * See tools/lib/bpf/skel_internal.h 6524 */ 6525 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 6526 6527 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 6528 { 6529 struct bpf_prog * __maybe_unused prog; 6530 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 6531 6532 switch (cmd) { 6533 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 6534 case BPF_PROG_TEST_RUN: 6535 if (attr->test.data_in || attr->test.data_out || 6536 attr->test.ctx_out || attr->test.duration || 6537 attr->test.repeat || attr->test.flags) 6538 return -EINVAL; 6539 6540 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 6541 if (IS_ERR(prog)) 6542 return PTR_ERR(prog); 6543 6544 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 6545 attr->test.ctx_size_in > U16_MAX) { 6546 bpf_prog_put(prog); 6547 return -EINVAL; 6548 } 6549 6550 run_ctx.bpf_cookie = 0; 6551 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 6552 /* recursion detected */ 6553 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 6554 bpf_prog_put(prog); 6555 return -EBUSY; 6556 } 6557 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 6558 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 6559 &run_ctx); 6560 bpf_prog_put(prog); 6561 return 0; 6562 #endif 6563 default: 6564 return ____bpf_sys_bpf(cmd, attr, size); 6565 } 6566 } 6567 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); 6568 6569 static const struct bpf_func_proto bpf_sys_bpf_proto = { 6570 .func = bpf_sys_bpf, 6571 .gpl_only = false, 6572 .ret_type = RET_INTEGER, 6573 .arg1_type = ARG_ANYTHING, 6574 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6575 .arg3_type = ARG_CONST_SIZE, 6576 }; 6577 6578 const struct bpf_func_proto * __weak 6579 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6580 { 6581 return bpf_base_func_proto(func_id, prog); 6582 } 6583 6584 BPF_CALL_1(bpf_sys_close, u32, fd) 6585 { 6586 /* When bpf program calls this helper there should not be 6587 * an fdget() without matching completed fdput(). 6588 * This helper is allowed in the following callchain only: 6589 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6590 */ 6591 return close_fd(fd); 6592 } 6593 6594 static const struct bpf_func_proto bpf_sys_close_proto = { 6595 .func = bpf_sys_close, 6596 .gpl_only = false, 6597 .ret_type = RET_INTEGER, 6598 .arg1_type = ARG_ANYTHING, 6599 }; 6600 6601 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6602 { 6603 *res = 0; 6604 if (flags) 6605 return -EINVAL; 6606 6607 if (name_sz <= 1 || name[name_sz - 1]) 6608 return -EINVAL; 6609 6610 if (!bpf_dump_raw_ok(current_cred())) 6611 return -EPERM; 6612 6613 *res = kallsyms_lookup_name(name); 6614 return *res ? 0 : -ENOENT; 6615 } 6616 6617 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6618 .func = bpf_kallsyms_lookup_name, 6619 .gpl_only = false, 6620 .ret_type = RET_INTEGER, 6621 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6622 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 6623 .arg3_type = ARG_ANYTHING, 6624 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6625 .arg4_size = sizeof(u64), 6626 }; 6627 6628 static const struct bpf_func_proto * 6629 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6630 { 6631 switch (func_id) { 6632 case BPF_FUNC_sys_bpf: 6633 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6634 ? NULL : &bpf_sys_bpf_proto; 6635 case BPF_FUNC_btf_find_by_name_kind: 6636 return &bpf_btf_find_by_name_kind_proto; 6637 case BPF_FUNC_sys_close: 6638 return &bpf_sys_close_proto; 6639 case BPF_FUNC_kallsyms_lookup_name: 6640 return &bpf_kallsyms_lookup_name_proto; 6641 default: 6642 return tracing_prog_func_proto(func_id, prog); 6643 } 6644 } 6645 6646 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6647 .get_func_proto = syscall_prog_func_proto, 6648 .is_valid_access = syscall_prog_is_valid_access, 6649 }; 6650 6651 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6652 .test_run = bpf_prog_test_run_syscall, 6653 }; 6654 6655 #ifdef CONFIG_SYSCTL 6656 static int bpf_stats_handler(const struct ctl_table *table, int write, 6657 void *buffer, size_t *lenp, loff_t *ppos) 6658 { 6659 struct static_key *key = (struct static_key *)table->data; 6660 static int saved_val; 6661 int val, ret; 6662 struct ctl_table tmp = { 6663 .data = &val, 6664 .maxlen = sizeof(val), 6665 .mode = table->mode, 6666 .extra1 = SYSCTL_ZERO, 6667 .extra2 = SYSCTL_ONE, 6668 }; 6669 6670 if (write && !capable(CAP_SYS_ADMIN)) 6671 return -EPERM; 6672 6673 mutex_lock(&bpf_stats_enabled_mutex); 6674 val = saved_val; 6675 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6676 if (write && !ret && val != saved_val) { 6677 if (val) 6678 static_key_slow_inc(key); 6679 else 6680 static_key_slow_dec(key); 6681 saved_val = val; 6682 } 6683 mutex_unlock(&bpf_stats_enabled_mutex); 6684 return ret; 6685 } 6686 6687 void __weak unpriv_ebpf_notify(int new_state) 6688 { 6689 } 6690 6691 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6692 void *buffer, size_t *lenp, loff_t *ppos) 6693 { 6694 int ret, unpriv_enable = *(int *)table->data; 6695 bool locked_state = unpriv_enable == 1; 6696 struct ctl_table tmp = *table; 6697 6698 if (write && !capable(CAP_SYS_ADMIN)) 6699 return -EPERM; 6700 6701 tmp.data = &unpriv_enable; 6702 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6703 if (write && !ret) { 6704 if (locked_state && unpriv_enable != 1) 6705 return -EPERM; 6706 *(int *)table->data = unpriv_enable; 6707 } 6708 6709 if (write) 6710 unpriv_ebpf_notify(unpriv_enable); 6711 6712 return ret; 6713 } 6714 6715 static const struct ctl_table bpf_syscall_table[] = { 6716 { 6717 .procname = "unprivileged_bpf_disabled", 6718 .data = &sysctl_unprivileged_bpf_disabled, 6719 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6720 .mode = 0644, 6721 .proc_handler = bpf_unpriv_handler, 6722 .extra1 = SYSCTL_ZERO, 6723 .extra2 = SYSCTL_TWO, 6724 }, 6725 { 6726 .procname = "bpf_stats_enabled", 6727 .data = &bpf_stats_enabled_key.key, 6728 .mode = 0644, 6729 .proc_handler = bpf_stats_handler, 6730 }, 6731 }; 6732 6733 static int __init bpf_syscall_sysctl_init(void) 6734 { 6735 register_sysctl_init("kernel", bpf_syscall_table); 6736 return 0; 6737 } 6738 late_initcall(bpf_syscall_sysctl_init); 6739 #endif /* CONFIG_SYSCTL */ 6740