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_RHASH && 1284 map->map_type != BPF_MAP_TYPE_ARRAY && 1285 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1286 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1287 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1288 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1289 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1290 ret = -EOPNOTSUPP; 1291 goto free_map_tab; 1292 } 1293 break; 1294 case BPF_TIMER: 1295 case BPF_WORKQUEUE: 1296 case BPF_TASK_WORK: 1297 if (map->map_type != BPF_MAP_TYPE_HASH && 1298 map->map_type != BPF_MAP_TYPE_RHASH && 1299 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1300 map->map_type != BPF_MAP_TYPE_ARRAY) { 1301 ret = -EOPNOTSUPP; 1302 goto free_map_tab; 1303 } 1304 break; 1305 case BPF_KPTR_UNREF: 1306 case BPF_KPTR_REF: 1307 case BPF_KPTR_PERCPU: 1308 case BPF_REFCOUNT: 1309 if (map->map_type != BPF_MAP_TYPE_HASH && 1310 map->map_type != BPF_MAP_TYPE_RHASH && 1311 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1312 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1313 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1314 map->map_type != BPF_MAP_TYPE_ARRAY && 1315 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1316 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1317 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1318 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1319 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1320 ret = -EOPNOTSUPP; 1321 goto free_map_tab; 1322 } 1323 break; 1324 case BPF_UPTR: 1325 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { 1326 ret = -EOPNOTSUPP; 1327 goto free_map_tab; 1328 } 1329 break; 1330 case BPF_LIST_HEAD: 1331 case BPF_RB_ROOT: 1332 if (map->map_type != BPF_MAP_TYPE_HASH && 1333 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1334 map->map_type != BPF_MAP_TYPE_ARRAY) { 1335 ret = -EOPNOTSUPP; 1336 goto free_map_tab; 1337 } 1338 break; 1339 default: 1340 /* Fail if map_type checks are missing for a field type */ 1341 ret = -EOPNOTSUPP; 1342 goto free_map_tab; 1343 } 1344 } 1345 } 1346 1347 ret = btf_check_and_fixup_fields(btf, map->record); 1348 if (ret < 0) 1349 goto free_map_tab; 1350 1351 if (map->ops->map_check_btf) { 1352 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1353 if (ret < 0) 1354 goto free_map_tab; 1355 } 1356 1357 return ret; 1358 free_map_tab: 1359 bpf_map_free_record(map); 1360 return ret; 1361 } 1362 1363 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size 1364 /* called via syscall */ 1365 static int map_create_alloc(union bpf_attr *attr, bpfptr_t uattr, struct bpf_verifier_log *log, 1366 struct bpf_map **mapp, struct bpf_token **tokenp) 1367 { 1368 const struct bpf_map_ops *ops; 1369 struct bpf_token *token = NULL; 1370 int numa_node = bpf_map_attr_numa_node(attr); 1371 u32 map_type = attr->map_type; 1372 struct bpf_map *map; 1373 bool token_flag; 1374 int err; 1375 1376 err = CHECK_ATTR(BPF_MAP_CREATE); 1377 if (err) { 1378 bpf_log(log, "Invalid attr.\n"); 1379 return -EINVAL; 1380 } 1381 1382 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it 1383 * to avoid per-map type checks tripping on unknown flag 1384 */ 1385 token_flag = attr->map_flags & BPF_F_TOKEN_FD; 1386 attr->map_flags &= ~BPF_F_TOKEN_FD; 1387 1388 if (attr->btf_vmlinux_value_type_id) { 1389 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 1390 bpf_log(log, "btf_vmlinux_value_type_id can only be used with struct_ops maps.\n"); 1391 return -EINVAL; 1392 } 1393 if (attr->btf_key_type_id || attr->btf_value_type_id) { 1394 bpf_log(log, "btf_vmlinux_value_type_id is mutually exclusive with btf_key_type_id and btf_value_type_id.\n"); 1395 return -EINVAL; 1396 } 1397 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1398 bpf_log(log, "Invalid btf_value_type_id.\n"); 1399 return -EINVAL; 1400 } 1401 1402 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1403 attr->map_type != BPF_MAP_TYPE_ARENA && 1404 attr->map_type != BPF_MAP_TYPE_RHASH && 1405 attr->map_extra != 0) { 1406 bpf_log(log, "Invalid map_extra.\n"); 1407 return -EINVAL; 1408 } 1409 1410 if (numa_node != NUMA_NO_NODE && 1411 ((unsigned int)numa_node >= nr_node_ids || 1412 !node_online(numa_node))) { 1413 bpf_log(log, "Invalid numa_node.\n"); 1414 return -EINVAL; 1415 } 1416 1417 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1418 map_type = attr->map_type; 1419 if (map_type >= ARRAY_SIZE(bpf_map_types)) { 1420 bpf_log(log, "Invalid map_type.\n"); 1421 return -EINVAL; 1422 } 1423 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1424 ops = bpf_map_types[map_type]; 1425 if (!ops) 1426 return -EINVAL; 1427 1428 if (ops->map_alloc_check) { 1429 err = ops->map_alloc_check(attr); 1430 if (err) 1431 return err; 1432 } 1433 if (attr->map_ifindex) 1434 ops = &bpf_map_offload_ops; 1435 if (!ops->map_mem_usage) 1436 return -EINVAL; 1437 1438 if (token_flag) { 1439 token = bpf_token_get_from_fd(attr->map_token_fd); 1440 if (IS_ERR(token)) { 1441 bpf_log(log, "Invalid map_token_fd.\n"); 1442 return PTR_ERR(token); 1443 } 1444 1445 /* if current token doesn't grant map creation permissions, 1446 * then we can't use this token, so ignore it and rely on 1447 * system-wide capabilities checks 1448 */ 1449 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || 1450 !bpf_token_allow_map_type(token, attr->map_type)) { 1451 bpf_token_put(token); 1452 token = NULL; 1453 } 1454 } 1455 1456 err = -EPERM; 1457 1458 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1459 * creation for unprivileged users; other actions depend 1460 * on fd availability and access to bpffs, so are dependent on 1461 * object creation success. Even with unprivileged BPF disabled, 1462 * capability checks are still carried out. 1463 */ 1464 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) 1465 goto put_token; 1466 1467 /* check privileged map type permissions */ 1468 switch (map_type) { 1469 case BPF_MAP_TYPE_ARRAY: 1470 case BPF_MAP_TYPE_PERCPU_ARRAY: 1471 case BPF_MAP_TYPE_PROG_ARRAY: 1472 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1473 case BPF_MAP_TYPE_CGROUP_ARRAY: 1474 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1475 case BPF_MAP_TYPE_HASH: 1476 case BPF_MAP_TYPE_RHASH: 1477 case BPF_MAP_TYPE_PERCPU_HASH: 1478 case BPF_MAP_TYPE_HASH_OF_MAPS: 1479 case BPF_MAP_TYPE_RINGBUF: 1480 case BPF_MAP_TYPE_USER_RINGBUF: 1481 case BPF_MAP_TYPE_CGROUP_STORAGE: 1482 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1483 /* unprivileged */ 1484 break; 1485 case BPF_MAP_TYPE_SK_STORAGE: 1486 case BPF_MAP_TYPE_INODE_STORAGE: 1487 case BPF_MAP_TYPE_TASK_STORAGE: 1488 case BPF_MAP_TYPE_CGRP_STORAGE: 1489 case BPF_MAP_TYPE_BLOOM_FILTER: 1490 case BPF_MAP_TYPE_LPM_TRIE: 1491 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1492 case BPF_MAP_TYPE_STACK_TRACE: 1493 case BPF_MAP_TYPE_QUEUE: 1494 case BPF_MAP_TYPE_STACK: 1495 case BPF_MAP_TYPE_LRU_HASH: 1496 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1497 case BPF_MAP_TYPE_STRUCT_OPS: 1498 case BPF_MAP_TYPE_CPUMAP: 1499 case BPF_MAP_TYPE_ARENA: 1500 case BPF_MAP_TYPE_INSN_ARRAY: 1501 if (!bpf_token_capable(token, CAP_BPF)) 1502 goto put_token; 1503 break; 1504 case BPF_MAP_TYPE_SOCKMAP: 1505 case BPF_MAP_TYPE_SOCKHASH: 1506 case BPF_MAP_TYPE_DEVMAP: 1507 case BPF_MAP_TYPE_DEVMAP_HASH: 1508 case BPF_MAP_TYPE_XSKMAP: 1509 if (!bpf_token_capable(token, CAP_NET_ADMIN)) 1510 goto put_token; 1511 break; 1512 default: 1513 WARN(1, "unsupported map type %d", map_type); 1514 goto put_token; 1515 } 1516 1517 map = ops->map_alloc(attr); 1518 if (IS_ERR(map)) { 1519 err = PTR_ERR(map); 1520 goto put_token; 1521 } 1522 map->ops = ops; 1523 map->map_type = map_type; 1524 1525 err = bpf_obj_name_cpy(map->name, attr->map_name, 1526 sizeof(attr->map_name)); 1527 if (err < 0) { 1528 bpf_log(log, "Invalid map_name.\n"); 1529 goto free_map; 1530 } 1531 1532 preempt_disable(); 1533 map->cookie = gen_cookie_next(&bpf_map_cookie); 1534 preempt_enable(); 1535 1536 atomic64_set(&map->refcnt, 1); 1537 atomic64_set(&map->usercnt, 1); 1538 mutex_init(&map->freeze_mutex); 1539 spin_lock_init(&map->owner_lock); 1540 1541 if (attr->btf_key_type_id || attr->btf_value_type_id || 1542 /* Even the map's value is a kernel's struct, 1543 * the bpf_prog.o must have BTF to begin with 1544 * to figure out the corresponding kernel's 1545 * counter part. Thus, attr->btf_fd has 1546 * to be valid also. 1547 */ 1548 attr->btf_vmlinux_value_type_id) { 1549 struct btf *btf; 1550 1551 btf = btf_get_by_fd(attr->btf_fd); 1552 if (IS_ERR(btf)) { 1553 bpf_log(log, "Invalid btf_fd.\n"); 1554 err = PTR_ERR(btf); 1555 goto free_map; 1556 } 1557 if (btf_is_kernel(btf)) { 1558 btf_put(btf); 1559 err = -EACCES; 1560 goto free_map; 1561 } 1562 map->btf = btf; 1563 1564 if (attr->btf_value_type_id) { 1565 err = map_check_btf(map, token, btf, attr->btf_key_type_id, 1566 attr->btf_value_type_id); 1567 if (err) 1568 goto free_map; 1569 } 1570 1571 map->btf_key_type_id = attr->btf_key_type_id; 1572 map->btf_value_type_id = attr->btf_value_type_id; 1573 map->btf_vmlinux_value_type_id = 1574 attr->btf_vmlinux_value_type_id; 1575 } 1576 1577 if (attr->excl_prog_hash) { 1578 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); 1579 1580 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { 1581 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1582 err = -EINVAL; 1583 goto free_map; 1584 } 1585 1586 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); 1587 if (!map->excl_prog_sha) { 1588 err = -ENOMEM; 1589 goto free_map; 1590 } 1591 1592 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) { 1593 err = -EFAULT; 1594 goto free_map; 1595 } 1596 1597 /* See libbpf: emit_signature_match() */ 1598 BUILD_BUG_ON(offsetof(struct bpf_map, excl) != SHA256_DIGEST_SIZE); 1599 BUILD_BUG_ON(!__same_type(map->excl, u32)); 1600 BUILD_BUG_ON(offsetof(struct bpf_map, sha) != 0); 1601 BUILD_BUG_ON(!__same_type(map->sha, u8[SHA256_DIGEST_SIZE])); 1602 map->excl = 1; 1603 } else if (attr->excl_prog_hash_size) { 1604 bpf_log(log, "Invalid excl_prog_hash_size.\n"); 1605 err = -EINVAL; 1606 goto free_map; 1607 } 1608 1609 *mapp = map; 1610 *tokenp = token; 1611 return 0; 1612 1613 free_map: 1614 bpf_map_free(map); 1615 put_token: 1616 bpf_token_put(token); 1617 return err; 1618 } 1619 1620 static int map_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common, 1621 bpfptr_t uattr_common, u32 size_common) 1622 { 1623 struct bpf_token *token = NULL; 1624 struct bpf_verifier_log *log; 1625 struct bpf_log_attr attr_log; 1626 struct bpf_map *map = NULL; 1627 int err, ret; 1628 int f_flags; 1629 1630 log = bpf_log_attr_create_vlog(&attr_log, attr_common, uattr_common, size_common); 1631 if (IS_ERR(log)) 1632 return PTR_ERR(log); 1633 1634 err = map_create_alloc(attr, uattr, log, &map, &token); 1635 1636 /* preserve original error even if log finalization is successful */ 1637 ret = bpf_log_attr_finalize(&attr_log, log); 1638 if (ret) 1639 err = ret; 1640 1641 kfree(log); 1642 1643 if (err) 1644 goto free_map; 1645 1646 f_flags = bpf_get_file_flag(attr->map_flags); 1647 if (f_flags < 0) { 1648 err = f_flags; 1649 goto free_map; 1650 } 1651 1652 err = security_bpf_map_create(map, attr, token, uattr.is_kernel); 1653 if (err) 1654 goto free_map_sec; 1655 1656 err = bpf_map_alloc_id(map); 1657 if (err) 1658 goto free_map_sec; 1659 1660 bpf_map_save_memcg(map); 1661 bpf_token_put(token); 1662 1663 err = bpf_map_new_fd(map, f_flags); 1664 if (err < 0) { 1665 /* failed to allocate fd. 1666 * bpf_map_put_with_uref() is needed because the above 1667 * bpf_map_alloc_id() has published the map 1668 * to the userspace and the userspace may 1669 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1670 */ 1671 bpf_map_put_with_uref(map); 1672 return err; 1673 } 1674 1675 return err; 1676 1677 free_map_sec: 1678 security_bpf_map_free(map); 1679 free_map: 1680 if (map) 1681 bpf_map_free(map); 1682 bpf_token_put(token); 1683 return err; 1684 } 1685 1686 void bpf_map_inc(struct bpf_map *map) 1687 { 1688 atomic64_inc(&map->refcnt); 1689 } 1690 EXPORT_SYMBOL_GPL(bpf_map_inc); 1691 1692 void bpf_map_inc_with_uref(struct bpf_map *map) 1693 { 1694 atomic64_inc(&map->refcnt); 1695 atomic64_inc(&map->usercnt); 1696 } 1697 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1698 1699 struct bpf_map *bpf_map_get(u32 ufd) 1700 { 1701 CLASS(fd, f)(ufd); 1702 struct bpf_map *map = __bpf_map_get(f); 1703 1704 if (!IS_ERR(map)) 1705 bpf_map_inc(map); 1706 1707 return map; 1708 } 1709 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); 1710 1711 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1712 { 1713 CLASS(fd, f)(ufd); 1714 struct bpf_map *map = __bpf_map_get(f); 1715 1716 if (!IS_ERR(map)) 1717 bpf_map_inc_with_uref(map); 1718 1719 return map; 1720 } 1721 1722 /* map_idr_lock should have been held or the map should have been 1723 * protected by rcu read lock. 1724 */ 1725 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1726 { 1727 int refold; 1728 1729 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1730 if (!refold) 1731 return ERR_PTR(-ENOENT); 1732 if (uref) 1733 atomic64_inc(&map->usercnt); 1734 1735 return map; 1736 } 1737 1738 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1739 { 1740 lockdep_assert(rcu_read_lock_held()); 1741 return __bpf_map_inc_not_zero(map, false); 1742 } 1743 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1744 1745 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value, 1746 bool delete) 1747 { 1748 return -ENOTSUPP; 1749 } 1750 1751 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1752 { 1753 if (key_size) 1754 return vmemdup_user(ukey, key_size); 1755 1756 if (ukey) 1757 return ERR_PTR(-EINVAL); 1758 1759 return NULL; 1760 } 1761 1762 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1763 { 1764 if (key_size) 1765 return kvmemdup_bpfptr(ukey, key_size); 1766 1767 if (!bpfptr_is_null(ukey)) 1768 return ERR_PTR(-EINVAL); 1769 1770 return NULL; 1771 } 1772 1773 /* last field in 'union bpf_attr' used by this command */ 1774 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1775 1776 static int map_lookup_elem(union bpf_attr *attr) 1777 { 1778 void __user *ukey = u64_to_user_ptr(attr->key); 1779 void __user *uvalue = u64_to_user_ptr(attr->value); 1780 struct bpf_map *map; 1781 void *key, *value; 1782 u32 value_size; 1783 int err; 1784 1785 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1786 return -EINVAL; 1787 1788 CLASS(fd, f)(attr->map_fd); 1789 map = __bpf_map_get(f); 1790 if (IS_ERR(map)) 1791 return PTR_ERR(map); 1792 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1793 return -EPERM; 1794 1795 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU); 1796 if (err) 1797 return err; 1798 1799 key = __bpf_copy_key(ukey, map->key_size); 1800 if (IS_ERR(key)) 1801 return PTR_ERR(key); 1802 1803 value_size = bpf_map_value_size(map, attr->flags); 1804 1805 err = -ENOMEM; 1806 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1807 if (!value) 1808 goto free_key; 1809 1810 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1811 if (copy_from_user(value, uvalue, value_size)) 1812 err = -EFAULT; 1813 else 1814 err = bpf_map_copy_value(map, key, value, attr->flags); 1815 goto free_value; 1816 } 1817 1818 err = bpf_map_copy_value(map, key, value, attr->flags); 1819 if (err) 1820 goto free_value; 1821 1822 err = -EFAULT; 1823 if (copy_to_user(uvalue, value, value_size) != 0) 1824 goto free_value; 1825 1826 err = 0; 1827 1828 free_value: 1829 kvfree(value); 1830 free_key: 1831 kvfree(key); 1832 return err; 1833 } 1834 1835 1836 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1837 1838 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1839 { 1840 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1841 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1842 struct bpf_map *map; 1843 void *key, *value; 1844 u32 value_size; 1845 int err; 1846 1847 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1848 return -EINVAL; 1849 1850 CLASS(fd, f)(attr->map_fd); 1851 map = __bpf_map_get(f); 1852 if (IS_ERR(map)) 1853 return PTR_ERR(map); 1854 bpf_map_write_active_inc(map); 1855 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1856 err = -EPERM; 1857 goto err_put; 1858 } 1859 1860 err = bpf_map_check_op_flags(map, attr->flags, ~0); 1861 if (err) 1862 goto err_put; 1863 1864 key = ___bpf_copy_key(ukey, map->key_size); 1865 if (IS_ERR(key)) { 1866 err = PTR_ERR(key); 1867 goto err_put; 1868 } 1869 1870 value_size = bpf_map_value_size(map, attr->flags); 1871 value = kvmemdup_bpfptr(uvalue, value_size); 1872 if (IS_ERR(value)) { 1873 err = PTR_ERR(value); 1874 goto free_key; 1875 } 1876 1877 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); 1878 if (!err) 1879 maybe_wait_bpf_programs(map); 1880 1881 kvfree(value); 1882 free_key: 1883 kvfree(key); 1884 err_put: 1885 bpf_map_write_active_dec(map); 1886 return err; 1887 } 1888 1889 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1890 1891 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1892 { 1893 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1894 struct bpf_map *map; 1895 void *key; 1896 int err; 1897 1898 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1899 return -EINVAL; 1900 1901 CLASS(fd, f)(attr->map_fd); 1902 map = __bpf_map_get(f); 1903 if (IS_ERR(map)) 1904 return PTR_ERR(map); 1905 bpf_map_write_active_inc(map); 1906 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1907 err = -EPERM; 1908 goto err_put; 1909 } 1910 1911 key = ___bpf_copy_key(ukey, map->key_size); 1912 if (IS_ERR(key)) { 1913 err = PTR_ERR(key); 1914 goto err_put; 1915 } 1916 1917 if (bpf_map_is_offloaded(map)) { 1918 err = bpf_map_offload_delete_elem(map, key); 1919 goto out; 1920 } else if (IS_FD_PROG_ARRAY(map) || 1921 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1922 /* These maps require sleepable context */ 1923 err = map->ops->map_delete_elem(map, key); 1924 goto out; 1925 } 1926 1927 bpf_disable_instrumentation(); 1928 rcu_read_lock(); 1929 err = map->ops->map_delete_elem(map, key); 1930 rcu_read_unlock(); 1931 bpf_enable_instrumentation(); 1932 if (!err) 1933 maybe_wait_bpf_programs(map); 1934 out: 1935 kvfree(key); 1936 err_put: 1937 bpf_map_write_active_dec(map); 1938 return err; 1939 } 1940 1941 /* last field in 'union bpf_attr' used by this command */ 1942 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1943 1944 static int map_get_next_key(union bpf_attr *attr) 1945 { 1946 void __user *ukey = u64_to_user_ptr(attr->key); 1947 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1948 struct bpf_map *map; 1949 void *key, *next_key; 1950 int err; 1951 1952 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1953 return -EINVAL; 1954 1955 CLASS(fd, f)(attr->map_fd); 1956 map = __bpf_map_get(f); 1957 if (IS_ERR(map)) 1958 return PTR_ERR(map); 1959 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1960 return -EPERM; 1961 1962 if (ukey) { 1963 key = __bpf_copy_key(ukey, map->key_size); 1964 if (IS_ERR(key)) 1965 return PTR_ERR(key); 1966 } else { 1967 key = NULL; 1968 } 1969 1970 err = -ENOMEM; 1971 next_key = kvmalloc(map->key_size, GFP_USER); 1972 if (!next_key) 1973 goto free_key; 1974 1975 if (bpf_map_is_offloaded(map)) { 1976 err = bpf_map_offload_get_next_key(map, key, next_key); 1977 goto out; 1978 } 1979 1980 rcu_read_lock(); 1981 err = map->ops->map_get_next_key(map, key, next_key); 1982 rcu_read_unlock(); 1983 out: 1984 if (err) 1985 goto free_next_key; 1986 1987 err = -EFAULT; 1988 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1989 goto free_next_key; 1990 1991 err = 0; 1992 1993 free_next_key: 1994 kvfree(next_key); 1995 free_key: 1996 kvfree(key); 1997 return err; 1998 } 1999 2000 int generic_map_delete_batch(struct bpf_map *map, 2001 const union bpf_attr *attr, 2002 union bpf_attr __user *uattr) 2003 { 2004 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2005 u32 cp, max_count; 2006 int err = 0; 2007 void *key; 2008 2009 if (attr->batch.elem_flags & ~BPF_F_LOCK) 2010 return -EINVAL; 2011 2012 if ((attr->batch.elem_flags & BPF_F_LOCK) && 2013 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2014 return -EINVAL; 2015 } 2016 2017 max_count = attr->batch.count; 2018 if (!max_count) 2019 return 0; 2020 2021 if (put_user(0, &uattr->batch.count)) 2022 return -EFAULT; 2023 2024 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2025 if (!key) 2026 return -ENOMEM; 2027 2028 for (cp = 0; cp < max_count; cp++) { 2029 err = -EFAULT; 2030 if (copy_from_user(key, keys + cp * map->key_size, 2031 map->key_size)) 2032 break; 2033 2034 if (bpf_map_is_offloaded(map)) { 2035 err = bpf_map_offload_delete_elem(map, key); 2036 break; 2037 } 2038 2039 bpf_disable_instrumentation(); 2040 rcu_read_lock(); 2041 err = map->ops->map_delete_elem(map, key); 2042 rcu_read_unlock(); 2043 bpf_enable_instrumentation(); 2044 if (err) 2045 break; 2046 cond_resched(); 2047 } 2048 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2049 err = -EFAULT; 2050 2051 kvfree(key); 2052 2053 return err; 2054 } 2055 2056 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 2057 const union bpf_attr *attr, 2058 union bpf_attr __user *uattr) 2059 { 2060 void __user *values = u64_to_user_ptr(attr->batch.values); 2061 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2062 u32 value_size, cp, max_count; 2063 void *key, *value; 2064 int err = 0; 2065 2066 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, 2067 BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS); 2068 if (err) 2069 return err; 2070 2071 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2072 2073 max_count = attr->batch.count; 2074 if (!max_count) 2075 return 0; 2076 2077 if (put_user(0, &uattr->batch.count)) 2078 return -EFAULT; 2079 2080 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2081 if (!key) 2082 return -ENOMEM; 2083 2084 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2085 if (!value) { 2086 kvfree(key); 2087 return -ENOMEM; 2088 } 2089 2090 for (cp = 0; cp < max_count; cp++) { 2091 err = -EFAULT; 2092 if (copy_from_user(key, keys + cp * map->key_size, 2093 map->key_size) || 2094 copy_from_user(value, values + cp * value_size, value_size)) 2095 break; 2096 2097 err = bpf_map_update_value(map, map_file, key, value, 2098 attr->batch.elem_flags); 2099 2100 if (err) 2101 break; 2102 cond_resched(); 2103 } 2104 2105 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2106 err = -EFAULT; 2107 2108 kvfree(value); 2109 kvfree(key); 2110 2111 return err; 2112 } 2113 2114 int generic_map_lookup_batch(struct bpf_map *map, 2115 const union bpf_attr *attr, 2116 union bpf_attr __user *uattr) 2117 { 2118 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 2119 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 2120 void __user *values = u64_to_user_ptr(attr->batch.values); 2121 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2122 void *buf, *buf_prevkey, *prev_key, *key, *value; 2123 u32 value_size, cp, max_count; 2124 int err; 2125 2126 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU); 2127 if (err) 2128 return err; 2129 2130 value_size = bpf_map_value_size(map, attr->batch.elem_flags); 2131 2132 max_count = attr->batch.count; 2133 if (!max_count) 2134 return 0; 2135 2136 if (put_user(0, &uattr->batch.count)) 2137 return -EFAULT; 2138 2139 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2140 if (!buf_prevkey) 2141 return -ENOMEM; 2142 2143 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 2144 if (!buf) { 2145 kvfree(buf_prevkey); 2146 return -ENOMEM; 2147 } 2148 2149 err = -EFAULT; 2150 prev_key = NULL; 2151 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 2152 goto free_buf; 2153 key = buf; 2154 value = key + map->key_size; 2155 if (ubatch) 2156 prev_key = buf_prevkey; 2157 2158 for (cp = 0; cp < max_count;) { 2159 rcu_read_lock(); 2160 err = map->ops->map_get_next_key(map, prev_key, key); 2161 rcu_read_unlock(); 2162 if (err) 2163 break; 2164 err = bpf_map_copy_value(map, key, value, 2165 attr->batch.elem_flags); 2166 2167 if (err == -ENOENT) 2168 goto next_key; 2169 2170 if (err) 2171 goto free_buf; 2172 2173 if (copy_to_user(keys + cp * map->key_size, key, 2174 map->key_size)) { 2175 err = -EFAULT; 2176 goto free_buf; 2177 } 2178 if (copy_to_user(values + cp * value_size, value, value_size)) { 2179 err = -EFAULT; 2180 goto free_buf; 2181 } 2182 2183 cp++; 2184 next_key: 2185 if (!prev_key) 2186 prev_key = buf_prevkey; 2187 2188 swap(prev_key, key); 2189 cond_resched(); 2190 } 2191 2192 if (err == -EFAULT) 2193 goto free_buf; 2194 2195 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 2196 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 2197 err = -EFAULT; 2198 2199 free_buf: 2200 kvfree(buf_prevkey); 2201 kvfree(buf); 2202 return err; 2203 } 2204 2205 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 2206 2207 static int map_lookup_and_delete_elem(union bpf_attr *attr) 2208 { 2209 void __user *ukey = u64_to_user_ptr(attr->key); 2210 void __user *uvalue = u64_to_user_ptr(attr->value); 2211 struct bpf_map *map; 2212 void *key, *value; 2213 u32 value_size; 2214 int err; 2215 2216 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 2217 return -EINVAL; 2218 2219 if (attr->flags & ~BPF_F_LOCK) 2220 return -EINVAL; 2221 2222 CLASS(fd, f)(attr->map_fd); 2223 map = __bpf_map_get(f); 2224 if (IS_ERR(map)) 2225 return PTR_ERR(map); 2226 bpf_map_write_active_inc(map); 2227 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 2228 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2229 err = -EPERM; 2230 goto err_put; 2231 } 2232 2233 if (attr->flags && 2234 (map->map_type == BPF_MAP_TYPE_QUEUE || 2235 map->map_type == BPF_MAP_TYPE_STACK)) { 2236 err = -EINVAL; 2237 goto err_put; 2238 } 2239 2240 if ((attr->flags & BPF_F_LOCK) && 2241 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2242 err = -EINVAL; 2243 goto err_put; 2244 } 2245 2246 key = __bpf_copy_key(ukey, map->key_size); 2247 if (IS_ERR(key)) { 2248 err = PTR_ERR(key); 2249 goto err_put; 2250 } 2251 2252 value_size = bpf_map_value_size(map, 0); 2253 2254 err = -ENOMEM; 2255 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2256 if (!value) 2257 goto free_key; 2258 2259 err = -ENOTSUPP; 2260 if (map->map_type == BPF_MAP_TYPE_QUEUE || 2261 map->map_type == BPF_MAP_TYPE_STACK) { 2262 err = map->ops->map_pop_elem(map, value); 2263 } else if (map->map_type == BPF_MAP_TYPE_HASH || 2264 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 2265 map->map_type == BPF_MAP_TYPE_LRU_HASH || 2266 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 2267 map->map_type == BPF_MAP_TYPE_RHASH || 2268 map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 2269 if (!bpf_map_is_offloaded(map)) { 2270 bpf_disable_instrumentation(); 2271 rcu_read_lock(); 2272 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 2273 rcu_read_unlock(); 2274 bpf_enable_instrumentation(); 2275 } 2276 } 2277 2278 if (err) 2279 goto free_value; 2280 2281 if (copy_to_user(uvalue, value, value_size) != 0) { 2282 err = -EFAULT; 2283 goto free_value; 2284 } 2285 2286 err = 0; 2287 2288 free_value: 2289 kvfree(value); 2290 free_key: 2291 kvfree(key); 2292 err_put: 2293 bpf_map_write_active_dec(map); 2294 return err; 2295 } 2296 2297 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2298 2299 static int map_freeze(const union bpf_attr *attr) 2300 { 2301 int err = 0; 2302 struct bpf_map *map; 2303 2304 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2305 return -EINVAL; 2306 2307 CLASS(fd, f)(attr->map_fd); 2308 map = __bpf_map_get(f); 2309 if (IS_ERR(map)) 2310 return PTR_ERR(map); 2311 2312 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) 2313 return -ENOTSUPP; 2314 2315 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) 2316 return -EPERM; 2317 2318 mutex_lock(&map->freeze_mutex); 2319 if (bpf_map_write_active(map)) { 2320 err = -EBUSY; 2321 goto err_put; 2322 } 2323 if (READ_ONCE(map->frozen)) { 2324 err = -EBUSY; 2325 goto err_put; 2326 } 2327 2328 WRITE_ONCE(map->frozen, true); 2329 err_put: 2330 mutex_unlock(&map->freeze_mutex); 2331 return err; 2332 } 2333 2334 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2335 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2336 [_id] = & _name ## _prog_ops, 2337 #define BPF_MAP_TYPE(_id, _ops) 2338 #define BPF_LINK_TYPE(_id, _name) 2339 #include <linux/bpf_types.h> 2340 #undef BPF_PROG_TYPE 2341 #undef BPF_MAP_TYPE 2342 #undef BPF_LINK_TYPE 2343 }; 2344 2345 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2346 { 2347 const struct bpf_prog_ops *ops; 2348 2349 if (type >= ARRAY_SIZE(bpf_prog_types)) 2350 return -EINVAL; 2351 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2352 ops = bpf_prog_types[type]; 2353 if (!ops) 2354 return -EINVAL; 2355 2356 if (!bpf_prog_is_offloaded(prog->aux)) 2357 prog->aux->ops = ops; 2358 else 2359 prog->aux->ops = &bpf_offload_prog_ops; 2360 prog->type = type; 2361 return 0; 2362 } 2363 2364 enum bpf_audit { 2365 BPF_AUDIT_LOAD, 2366 BPF_AUDIT_UNLOAD, 2367 BPF_AUDIT_MAX, 2368 }; 2369 2370 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2371 [BPF_AUDIT_LOAD] = "LOAD", 2372 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2373 }; 2374 2375 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2376 { 2377 struct audit_context *ctx = NULL; 2378 struct audit_buffer *ab; 2379 2380 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2381 return; 2382 if (audit_enabled == AUDIT_OFF) 2383 return; 2384 if (!in_hardirq() && !irqs_disabled()) 2385 ctx = audit_context(); 2386 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2387 if (unlikely(!ab)) 2388 return; 2389 audit_log_format(ab, "prog-id=%u op=%s", 2390 prog->aux->id, bpf_audit_str[op]); 2391 audit_log_end(ab); 2392 } 2393 2394 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2395 { 2396 int id; 2397 2398 idr_preload(GFP_KERNEL); 2399 spin_lock_bh(&prog_idr_lock); 2400 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2401 if (id > 0) 2402 prog->aux->id = id; 2403 spin_unlock_bh(&prog_idr_lock); 2404 idr_preload_end(); 2405 2406 /* id is in [1, INT_MAX) */ 2407 if (WARN_ON_ONCE(!id)) 2408 return -ENOSPC; 2409 2410 return id > 0 ? 0 : id; 2411 } 2412 2413 void bpf_prog_free_id(struct bpf_prog *prog) 2414 { 2415 unsigned long flags; 2416 2417 /* cBPF to eBPF migrations are currently not in the idr store. 2418 * Offloaded programs are removed from the store when their device 2419 * disappears - even if someone grabs an fd to them they are unusable, 2420 * simply waiting for refcnt to drop to be freed. 2421 */ 2422 if (!prog->aux->id) 2423 return; 2424 2425 spin_lock_irqsave(&prog_idr_lock, flags); 2426 idr_remove(&prog_idr, prog->aux->id); 2427 prog->aux->id = 0; 2428 spin_unlock_irqrestore(&prog_idr_lock, flags); 2429 } 2430 2431 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2432 { 2433 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2434 2435 kvfree(aux->func_info); 2436 kfree(aux->func_info_aux); 2437 free_uid(aux->user); 2438 security_bpf_prog_free(aux->prog); 2439 bpf_prog_free(aux->prog); 2440 } 2441 2442 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2443 { 2444 bpf_prog_kallsyms_del_all(prog); 2445 btf_put(prog->aux->btf); 2446 module_put(prog->aux->mod); 2447 kvfree(prog->aux->jited_linfo); 2448 kvfree(prog->aux->linfo); 2449 kfree(prog->aux->kfunc_tab); 2450 kfree(prog->aux->ctx_arg_info); 2451 if (prog->aux->attach_btf) 2452 btf_put(prog->aux->attach_btf); 2453 2454 if (deferred) { 2455 if (prog->sleepable) 2456 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2457 else 2458 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2459 } else { 2460 __bpf_prog_put_rcu(&prog->aux->rcu); 2461 } 2462 } 2463 2464 static void bpf_prog_put_deferred(struct work_struct *work) 2465 { 2466 struct bpf_prog_aux *aux; 2467 struct bpf_prog *prog; 2468 2469 aux = container_of(work, struct bpf_prog_aux, work); 2470 prog = aux->prog; 2471 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2472 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2473 bpf_prog_free_id(prog); 2474 __bpf_prog_put_noref(prog, true); 2475 } 2476 2477 static void __bpf_prog_put(struct bpf_prog *prog) 2478 { 2479 struct bpf_prog_aux *aux = prog->aux; 2480 2481 if (atomic64_dec_and_test(&aux->refcnt)) { 2482 if (in_hardirq() || irqs_disabled()) { 2483 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2484 schedule_work(&aux->work); 2485 } else { 2486 bpf_prog_put_deferred(&aux->work); 2487 } 2488 } 2489 } 2490 2491 void bpf_prog_put(struct bpf_prog *prog) 2492 { 2493 __bpf_prog_put(prog); 2494 } 2495 EXPORT_SYMBOL_GPL(bpf_prog_put); 2496 2497 static int bpf_prog_release(struct inode *inode, struct file *filp) 2498 { 2499 struct bpf_prog *prog = filp->private_data; 2500 2501 bpf_prog_put(prog); 2502 return 0; 2503 } 2504 2505 struct bpf_prog_kstats { 2506 u64 nsecs; 2507 u64 cnt; 2508 u64 misses; 2509 }; 2510 2511 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2512 { 2513 struct bpf_prog_stats *stats; 2514 unsigned int flags; 2515 2516 if (unlikely(!prog->stats)) 2517 return; 2518 2519 stats = this_cpu_ptr(prog->stats); 2520 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2521 u64_stats_inc(&stats->misses); 2522 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2523 } 2524 2525 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2526 struct bpf_prog_kstats *stats) 2527 { 2528 u64 nsecs = 0, cnt = 0, misses = 0; 2529 int cpu; 2530 2531 for_each_possible_cpu(cpu) { 2532 const struct bpf_prog_stats *st; 2533 unsigned int start; 2534 u64 tnsecs, tcnt, tmisses; 2535 2536 st = per_cpu_ptr(prog->stats, cpu); 2537 do { 2538 start = u64_stats_fetch_begin(&st->syncp); 2539 tnsecs = u64_stats_read(&st->nsecs); 2540 tcnt = u64_stats_read(&st->cnt); 2541 tmisses = u64_stats_read(&st->misses); 2542 } while (u64_stats_fetch_retry(&st->syncp, start)); 2543 nsecs += tnsecs; 2544 cnt += tcnt; 2545 misses += tmisses; 2546 } 2547 stats->nsecs = nsecs; 2548 stats->cnt = cnt; 2549 stats->misses = misses; 2550 } 2551 2552 #ifdef CONFIG_PROC_FS 2553 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2554 { 2555 const struct bpf_prog *prog = filp->private_data; 2556 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2557 struct bpf_prog_kstats stats; 2558 2559 bpf_prog_get_stats(prog, &stats); 2560 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2561 seq_printf(m, 2562 "prog_type:\t%u\n" 2563 "prog_jited:\t%u\n" 2564 "prog_tag:\t%s\n" 2565 "memlock:\t%llu\n" 2566 "prog_id:\t%u\n" 2567 "run_time_ns:\t%llu\n" 2568 "run_cnt:\t%llu\n" 2569 "recursion_misses:\t%llu\n" 2570 "verified_insns:\t%u\n", 2571 prog->type, 2572 prog->jited, 2573 prog_tag, 2574 prog->pages * 1ULL << PAGE_SHIFT, 2575 prog->aux->id, 2576 stats.nsecs, 2577 stats.cnt, 2578 stats.misses, 2579 prog->aux->verified_insns); 2580 } 2581 #endif 2582 2583 const struct file_operations bpf_prog_fops = { 2584 #ifdef CONFIG_PROC_FS 2585 .show_fdinfo = bpf_prog_show_fdinfo, 2586 #endif 2587 .release = bpf_prog_release, 2588 .read = bpf_dummy_read, 2589 .write = bpf_dummy_write, 2590 }; 2591 2592 int bpf_prog_new_fd(struct bpf_prog *prog) 2593 { 2594 int ret; 2595 2596 ret = security_bpf_prog(prog); 2597 if (ret < 0) 2598 return ret; 2599 2600 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2601 O_RDWR | O_CLOEXEC); 2602 } 2603 2604 void bpf_prog_add(struct bpf_prog *prog, int i) 2605 { 2606 atomic64_add(i, &prog->aux->refcnt); 2607 } 2608 EXPORT_SYMBOL_GPL(bpf_prog_add); 2609 2610 void bpf_prog_sub(struct bpf_prog *prog, int i) 2611 { 2612 /* Only to be used for undoing previous bpf_prog_add() in some 2613 * error path. We still know that another entity in our call 2614 * path holds a reference to the program, thus atomic_sub() can 2615 * be safely used in such cases! 2616 */ 2617 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2618 } 2619 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2620 2621 void bpf_prog_inc(struct bpf_prog *prog) 2622 { 2623 atomic64_inc(&prog->aux->refcnt); 2624 } 2625 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2626 2627 /* prog_idr_lock should have been held */ 2628 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2629 { 2630 int refold; 2631 2632 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2633 2634 if (!refold) 2635 return ERR_PTR(-ENOENT); 2636 2637 return prog; 2638 } 2639 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2640 2641 bool bpf_prog_get_ok(struct bpf_prog *prog, 2642 enum bpf_prog_type *attach_type, bool attach_drv) 2643 { 2644 /* not an attachment, just a refcount inc, always allow */ 2645 if (!attach_type) 2646 return true; 2647 2648 if (prog->type != *attach_type) 2649 return false; 2650 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2651 return false; 2652 2653 return true; 2654 } 2655 2656 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2657 bool attach_drv) 2658 { 2659 CLASS(fd, f)(ufd); 2660 struct bpf_prog *prog; 2661 2662 if (fd_empty(f)) 2663 return ERR_PTR(-EBADF); 2664 if (fd_file(f)->f_op != &bpf_prog_fops) 2665 return ERR_PTR(-EINVAL); 2666 2667 prog = fd_file(f)->private_data; 2668 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2669 return ERR_PTR(-EINVAL); 2670 2671 bpf_prog_inc(prog); 2672 return prog; 2673 } 2674 2675 struct bpf_prog *bpf_prog_get(u32 ufd) 2676 { 2677 return __bpf_prog_get(ufd, NULL, false); 2678 } 2679 2680 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2681 bool attach_drv) 2682 { 2683 return __bpf_prog_get(ufd, &type, attach_drv); 2684 } 2685 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2686 2687 /* Initially all BPF programs could be loaded w/o specifying 2688 * expected_attach_type. Later for some of them specifying expected_attach_type 2689 * at load time became required so that program could be validated properly. 2690 * Programs of types that are allowed to be loaded both w/ and w/o (for 2691 * backward compatibility) expected_attach_type, should have the default attach 2692 * type assigned to expected_attach_type for the latter case, so that it can be 2693 * validated later at attach time. 2694 * 2695 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2696 * prog type requires it but has some attach types that have to be backward 2697 * compatible. 2698 */ 2699 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2700 { 2701 switch (attr->prog_type) { 2702 case BPF_PROG_TYPE_CGROUP_SOCK: 2703 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2704 * exist so checking for non-zero is the way to go here. 2705 */ 2706 if (!attr->expected_attach_type) 2707 attr->expected_attach_type = 2708 BPF_CGROUP_INET_SOCK_CREATE; 2709 break; 2710 case BPF_PROG_TYPE_SK_REUSEPORT: 2711 if (!attr->expected_attach_type) 2712 attr->expected_attach_type = 2713 BPF_SK_REUSEPORT_SELECT; 2714 break; 2715 } 2716 } 2717 2718 static int 2719 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2720 enum bpf_attach_type expected_attach_type, 2721 struct btf *attach_btf, u32 btf_id, 2722 struct bpf_prog *dst_prog) 2723 { 2724 if (btf_id) { 2725 if (btf_id > BTF_MAX_TYPE) 2726 return -EINVAL; 2727 2728 if (!attach_btf && !dst_prog) 2729 return -EINVAL; 2730 2731 switch (prog_type) { 2732 case BPF_PROG_TYPE_TRACING: 2733 case BPF_PROG_TYPE_LSM: 2734 case BPF_PROG_TYPE_STRUCT_OPS: 2735 case BPF_PROG_TYPE_EXT: 2736 break; 2737 default: 2738 return -EINVAL; 2739 } 2740 } 2741 2742 if (attach_btf && (!btf_id || dst_prog)) 2743 return -EINVAL; 2744 2745 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2746 prog_type != BPF_PROG_TYPE_EXT) 2747 return -EINVAL; 2748 2749 switch (prog_type) { 2750 case BPF_PROG_TYPE_CGROUP_SOCK: 2751 switch (expected_attach_type) { 2752 case BPF_CGROUP_INET_SOCK_CREATE: 2753 case BPF_CGROUP_INET_SOCK_RELEASE: 2754 case BPF_CGROUP_INET4_POST_BIND: 2755 case BPF_CGROUP_INET6_POST_BIND: 2756 return 0; 2757 default: 2758 return -EINVAL; 2759 } 2760 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2761 switch (expected_attach_type) { 2762 case BPF_CGROUP_INET4_BIND: 2763 case BPF_CGROUP_INET6_BIND: 2764 case BPF_CGROUP_INET4_CONNECT: 2765 case BPF_CGROUP_INET6_CONNECT: 2766 case BPF_CGROUP_UNIX_CONNECT: 2767 case BPF_CGROUP_INET4_GETPEERNAME: 2768 case BPF_CGROUP_INET6_GETPEERNAME: 2769 case BPF_CGROUP_UNIX_GETPEERNAME: 2770 case BPF_CGROUP_INET4_GETSOCKNAME: 2771 case BPF_CGROUP_INET6_GETSOCKNAME: 2772 case BPF_CGROUP_UNIX_GETSOCKNAME: 2773 case BPF_CGROUP_UDP4_SENDMSG: 2774 case BPF_CGROUP_UDP6_SENDMSG: 2775 case BPF_CGROUP_UNIX_SENDMSG: 2776 case BPF_CGROUP_UDP4_RECVMSG: 2777 case BPF_CGROUP_UDP6_RECVMSG: 2778 case BPF_CGROUP_UNIX_RECVMSG: 2779 return 0; 2780 default: 2781 return -EINVAL; 2782 } 2783 case BPF_PROG_TYPE_CGROUP_SKB: 2784 switch (expected_attach_type) { 2785 case BPF_CGROUP_INET_INGRESS: 2786 case BPF_CGROUP_INET_EGRESS: 2787 return 0; 2788 default: 2789 return -EINVAL; 2790 } 2791 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2792 switch (expected_attach_type) { 2793 case BPF_CGROUP_SETSOCKOPT: 2794 case BPF_CGROUP_GETSOCKOPT: 2795 return 0; 2796 default: 2797 return -EINVAL; 2798 } 2799 case BPF_PROG_TYPE_SK_LOOKUP: 2800 if (expected_attach_type == BPF_SK_LOOKUP) 2801 return 0; 2802 return -EINVAL; 2803 case BPF_PROG_TYPE_SK_REUSEPORT: 2804 switch (expected_attach_type) { 2805 case BPF_SK_REUSEPORT_SELECT: 2806 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2807 return 0; 2808 default: 2809 return -EINVAL; 2810 } 2811 case BPF_PROG_TYPE_NETFILTER: 2812 if (expected_attach_type == BPF_NETFILTER) 2813 return 0; 2814 return -EINVAL; 2815 case BPF_PROG_TYPE_SYSCALL: 2816 case BPF_PROG_TYPE_EXT: 2817 if (expected_attach_type) 2818 return -EINVAL; 2819 fallthrough; 2820 default: 2821 return 0; 2822 } 2823 } 2824 2825 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2826 { 2827 switch (prog_type) { 2828 case BPF_PROG_TYPE_SCHED_CLS: 2829 case BPF_PROG_TYPE_SCHED_ACT: 2830 case BPF_PROG_TYPE_XDP: 2831 case BPF_PROG_TYPE_LWT_IN: 2832 case BPF_PROG_TYPE_LWT_OUT: 2833 case BPF_PROG_TYPE_LWT_XMIT: 2834 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2835 case BPF_PROG_TYPE_SK_SKB: 2836 case BPF_PROG_TYPE_SK_MSG: 2837 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2838 case BPF_PROG_TYPE_CGROUP_DEVICE: 2839 case BPF_PROG_TYPE_CGROUP_SOCK: 2840 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2841 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2842 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2843 case BPF_PROG_TYPE_SOCK_OPS: 2844 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2845 case BPF_PROG_TYPE_NETFILTER: 2846 return true; 2847 case BPF_PROG_TYPE_CGROUP_SKB: 2848 /* always unpriv */ 2849 case BPF_PROG_TYPE_SK_REUSEPORT: 2850 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2851 default: 2852 return false; 2853 } 2854 } 2855 2856 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2857 { 2858 switch (prog_type) { 2859 case BPF_PROG_TYPE_KPROBE: 2860 case BPF_PROG_TYPE_TRACEPOINT: 2861 case BPF_PROG_TYPE_PERF_EVENT: 2862 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2863 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2864 case BPF_PROG_TYPE_TRACING: 2865 case BPF_PROG_TYPE_LSM: 2866 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2867 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2868 return true; 2869 default: 2870 return false; 2871 } 2872 } 2873 2874 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr, 2875 bool is_kernel) 2876 { 2877 bpfptr_t usig = make_bpfptr(attr->signature, is_kernel); 2878 struct bpf_dynptr_kern sig_ptr, insns_ptr; 2879 struct bpf_key *key = NULL; 2880 void *sig; 2881 int err = 0; 2882 2883 /* 2884 * Don't attempt to use kmalloc_large or vmalloc for signatures. 2885 * Practical signature for BPF program should be below this limit. 2886 */ 2887 if (attr->signature_size > KMALLOC_MAX_CACHE_SIZE) 2888 return -EINVAL; 2889 2890 if (system_keyring_id_check(attr->keyring_id) == 0) 2891 key = bpf_lookup_system_key(attr->keyring_id); 2892 else 2893 key = bpf_lookup_user_key(attr->keyring_id, 0); 2894 2895 if (!key) 2896 return -EINVAL; 2897 2898 sig = kvmemdup_bpfptr(usig, attr->signature_size); 2899 if (IS_ERR(sig)) { 2900 bpf_key_put(key); 2901 return PTR_ERR(sig); 2902 } 2903 2904 bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0, 2905 attr->signature_size); 2906 bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0, 2907 prog->len * sizeof(struct bpf_insn)); 2908 2909 err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr, 2910 (struct bpf_dynptr *)&sig_ptr, key); 2911 2912 bpf_key_put(key); 2913 kvfree(sig); 2914 return err; 2915 } 2916 2917 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog) 2918 { 2919 int err; 2920 int i; 2921 2922 for (i = 0; i < prog->aux->used_map_cnt; i++) { 2923 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY) 2924 continue; 2925 2926 err = bpf_insn_array_ready(prog->aux->used_maps[i]); 2927 if (err) 2928 return err; 2929 } 2930 2931 return 0; 2932 } 2933 2934 /* last field in 'union bpf_attr' used by this command */ 2935 #define BPF_PROG_LOAD_LAST_FIELD keyring_id 2936 2937 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 2938 { 2939 enum bpf_prog_type type = attr->prog_type; 2940 struct bpf_prog *prog, *dst_prog = NULL; 2941 struct btf *attach_btf = NULL; 2942 struct bpf_token *token = NULL; 2943 bool bpf_cap; 2944 int err; 2945 char license[128]; 2946 2947 if (CHECK_ATTR(BPF_PROG_LOAD)) 2948 return -EINVAL; 2949 2950 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2951 BPF_F_ANY_ALIGNMENT | 2952 BPF_F_TEST_STATE_FREQ | 2953 BPF_F_SLEEPABLE | 2954 BPF_F_TEST_RND_HI32 | 2955 BPF_F_XDP_HAS_FRAGS | 2956 BPF_F_XDP_DEV_BOUND_ONLY | 2957 BPF_F_TEST_REG_INVARIANTS | 2958 BPF_F_TOKEN_FD)) 2959 return -EINVAL; 2960 2961 bpf_prog_load_fixup_attach_type(attr); 2962 2963 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2964 token = bpf_token_get_from_fd(attr->prog_token_fd); 2965 if (IS_ERR(token)) 2966 return PTR_ERR(token); 2967 /* if current token doesn't grant prog loading permissions, 2968 * then we can't use this token, so ignore it and rely on 2969 * system-wide capabilities checks 2970 */ 2971 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2972 !bpf_token_allow_prog_type(token, attr->prog_type, 2973 attr->expected_attach_type)) { 2974 bpf_token_put(token); 2975 token = NULL; 2976 } 2977 } 2978 2979 bpf_cap = bpf_token_capable(token, CAP_BPF); 2980 err = -EPERM; 2981 2982 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2983 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2984 !bpf_cap) 2985 goto put_token; 2986 2987 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2988 * creation for unprivileged users; other actions depend 2989 * on fd availability and access to bpffs, so are dependent on 2990 * object creation success. Even with unprivileged BPF disabled, 2991 * capability checks are still carried out for these 2992 * and other operations. 2993 */ 2994 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 2995 goto put_token; 2996 2997 if (attr->insn_cnt == 0 || 2998 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 2999 err = -E2BIG; 3000 goto put_token; 3001 } 3002 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 3003 type != BPF_PROG_TYPE_CGROUP_SKB && 3004 !bpf_cap) 3005 goto put_token; 3006 3007 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 3008 goto put_token; 3009 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 3010 goto put_token; 3011 3012 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 3013 * or btf, we need to check which one it is 3014 */ 3015 if (attr->attach_prog_fd) { 3016 dst_prog = bpf_prog_get(attr->attach_prog_fd); 3017 if (IS_ERR(dst_prog)) { 3018 dst_prog = NULL; 3019 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 3020 if (IS_ERR(attach_btf)) { 3021 err = -EINVAL; 3022 goto put_token; 3023 } 3024 if (!btf_is_kernel(attach_btf)) { 3025 /* attaching through specifying bpf_prog's BTF 3026 * objects directly might be supported eventually 3027 */ 3028 btf_put(attach_btf); 3029 err = -ENOTSUPP; 3030 goto put_token; 3031 } 3032 } 3033 } else if (attr->attach_btf_id) { 3034 /* fall back to vmlinux BTF, if BTF type ID is specified */ 3035 attach_btf = bpf_get_btf_vmlinux(); 3036 if (IS_ERR(attach_btf)) { 3037 err = PTR_ERR(attach_btf); 3038 goto put_token; 3039 } 3040 if (!attach_btf) { 3041 err = -EINVAL; 3042 goto put_token; 3043 } 3044 btf_get(attach_btf); 3045 } 3046 3047 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 3048 attach_btf, attr->attach_btf_id, 3049 dst_prog)) { 3050 if (dst_prog) 3051 bpf_prog_put(dst_prog); 3052 if (attach_btf) 3053 btf_put(attach_btf); 3054 err = -EINVAL; 3055 goto put_token; 3056 } 3057 3058 /* plain bpf_prog allocation */ 3059 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 3060 if (!prog) { 3061 if (dst_prog) 3062 bpf_prog_put(dst_prog); 3063 if (attach_btf) 3064 btf_put(attach_btf); 3065 err = -EINVAL; 3066 goto put_token; 3067 } 3068 3069 prog->expected_attach_type = attr->expected_attach_type; 3070 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 3071 prog->aux->attach_btf = attach_btf; 3072 prog->aux->attach_btf_id = attr->attach_btf_id; 3073 prog->aux->dst_prog = dst_prog; 3074 prog->aux->dev_bound = !!attr->prog_ifindex; 3075 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 3076 3077 /* move token into prog->aux, reuse taken refcnt */ 3078 prog->aux->token = token; 3079 token = NULL; 3080 3081 prog->aux->user = get_current_user(); 3082 prog->len = attr->insn_cnt; 3083 3084 err = -EFAULT; 3085 if (copy_from_bpfptr(prog->insns, 3086 make_bpfptr(attr->insns, uattr.is_kernel), 3087 bpf_prog_insn_size(prog)) != 0) 3088 goto free_prog; 3089 /* copy eBPF program license from user space */ 3090 if (strncpy_from_bpfptr(license, 3091 make_bpfptr(attr->license, uattr.is_kernel), 3092 sizeof(license) - 1) < 0) 3093 goto free_prog; 3094 license[sizeof(license) - 1] = 0; 3095 3096 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 3097 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 3098 3099 if (attr->signature) { 3100 err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel); 3101 if (err) 3102 goto free_prog; 3103 } 3104 3105 prog->orig_prog = NULL; 3106 prog->jited = 0; 3107 3108 atomic64_set(&prog->aux->refcnt, 1); 3109 3110 if (bpf_prog_is_dev_bound(prog->aux)) { 3111 err = bpf_prog_dev_bound_init(prog, attr); 3112 if (err) 3113 goto free_prog; 3114 } 3115 3116 if (type == BPF_PROG_TYPE_EXT && dst_prog && 3117 bpf_prog_is_dev_bound(dst_prog->aux)) { 3118 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 3119 if (err) 3120 goto free_prog; 3121 } 3122 3123 /* 3124 * Bookkeeping for managing the program attachment chain. 3125 * 3126 * It might be tempting to set attach_tracing_prog flag at the attachment 3127 * time, but this will not prevent from loading bunch of tracing prog 3128 * first, then attach them one to another. 3129 * 3130 * The flag attach_tracing_prog is set for the whole program lifecycle, and 3131 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 3132 * programs cannot change attachment target. 3133 */ 3134 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 3135 dst_prog->type == BPF_PROG_TYPE_TRACING) { 3136 prog->aux->attach_tracing_prog = true; 3137 } 3138 3139 /* find program type: socket_filter vs tracing_filter */ 3140 err = find_prog_type(type, prog); 3141 if (err < 0) 3142 goto free_prog; 3143 3144 prog->aux->load_time = ktime_get_boottime_ns(); 3145 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 3146 sizeof(attr->prog_name)); 3147 if (err < 0) 3148 goto free_prog; 3149 3150 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel); 3151 if (err) 3152 goto free_prog; 3153 3154 /* run eBPF verifier */ 3155 err = bpf_check(&prog, attr, uattr, attr_log); 3156 if (err < 0) 3157 goto free_used_maps; 3158 3159 err = bpf_prog_mark_insn_arrays_ready(prog); 3160 if (err < 0) 3161 goto free_used_maps; 3162 3163 err = bpf_prog_alloc_id(prog); 3164 if (err) 3165 goto free_used_maps; 3166 3167 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 3168 * effectively publicly exposed. However, retrieving via 3169 * bpf_prog_get_fd_by_id() will take another reference, 3170 * therefore it cannot be gone underneath us. 3171 * 3172 * Only for the time /after/ successful bpf_prog_new_fd() 3173 * and before returning to userspace, we might just hold 3174 * one reference and any parallel close on that fd could 3175 * rip everything out. Hence, below notifications must 3176 * happen before bpf_prog_new_fd(). 3177 * 3178 * Also, any failure handling from this point onwards must 3179 * be using bpf_prog_put() given the program is exposed. 3180 */ 3181 bpf_prog_kallsyms_add(prog); 3182 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 3183 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 3184 3185 err = bpf_prog_new_fd(prog); 3186 if (err < 0) 3187 bpf_prog_put(prog); 3188 return err; 3189 3190 free_used_maps: 3191 /* In case we have subprogs, we need to wait for a grace 3192 * period before we can tear down JIT memory since symbols 3193 * are already exposed under kallsyms. 3194 */ 3195 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 3196 return err; 3197 3198 free_prog: 3199 free_uid(prog->aux->user); 3200 if (prog->aux->attach_btf) 3201 btf_put(prog->aux->attach_btf); 3202 bpf_prog_free(prog); 3203 put_token: 3204 bpf_token_put(token); 3205 return err; 3206 } 3207 3208 #define BPF_OBJ_LAST_FIELD path_fd 3209 3210 static int bpf_obj_pin(const union bpf_attr *attr) 3211 { 3212 int path_fd; 3213 3214 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3215 return -EINVAL; 3216 3217 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3218 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3219 return -EINVAL; 3220 3221 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3222 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3223 u64_to_user_ptr(attr->pathname)); 3224 } 3225 3226 static int bpf_obj_get(const union bpf_attr *attr) 3227 { 3228 int path_fd; 3229 3230 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3231 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3232 return -EINVAL; 3233 3234 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3235 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3236 return -EINVAL; 3237 3238 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3239 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3240 attr->file_flags); 3241 } 3242 3243 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3244 * "sleepable" semantics, which normally would mean that BPF link's attach 3245 * hook can dereference link or link's underlying program for some time after 3246 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3247 * BPF program itself can be non-sleepable, yet, because it's transitively 3248 * reachable through BPF link, its freeing has to be delayed until after RCU 3249 * Tasks Trace GP. 3250 */ 3251 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3252 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3253 enum bpf_attach_type attach_type, bool sleepable) 3254 { 3255 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3256 atomic64_set(&link->refcnt, 1); 3257 link->type = type; 3258 link->sleepable = sleepable; 3259 link->id = 0; 3260 link->ops = ops; 3261 link->prog = prog; 3262 link->attach_type = attach_type; 3263 } 3264 3265 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3266 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3267 enum bpf_attach_type attach_type) 3268 { 3269 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); 3270 } 3271 3272 static void bpf_link_free_id(int id) 3273 { 3274 if (!id) 3275 return; 3276 3277 spin_lock_bh(&link_idr_lock); 3278 idr_remove(&link_idr, id); 3279 spin_unlock_bh(&link_idr_lock); 3280 } 3281 3282 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3283 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3284 * anon_inode's release() call. This helper marks bpf_link as 3285 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3286 * is not decremented, it's the responsibility of a calling code that failed 3287 * to complete bpf_link initialization. 3288 * This helper eventually calls link's dealloc callback, but does not call 3289 * link's release callback. 3290 */ 3291 void bpf_link_cleanup(struct bpf_link_primer *primer) 3292 { 3293 primer->link->prog = NULL; 3294 bpf_link_free_id(primer->id); 3295 fput(primer->file); 3296 put_unused_fd(primer->fd); 3297 } 3298 3299 void bpf_link_inc(struct bpf_link *link) 3300 { 3301 atomic64_inc(&link->refcnt); 3302 } 3303 3304 static void bpf_link_dealloc(struct bpf_link *link) 3305 { 3306 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3307 if (link->prog) 3308 bpf_prog_put(link->prog); 3309 3310 /* free bpf_link and its containing memory */ 3311 if (link->ops->dealloc_deferred) 3312 link->ops->dealloc_deferred(link); 3313 else 3314 link->ops->dealloc(link); 3315 } 3316 3317 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3318 { 3319 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3320 3321 bpf_link_dealloc(link); 3322 } 3323 3324 static bool bpf_link_is_tracepoint(struct bpf_link *link) 3325 { 3326 /* 3327 * Only these combinations support a tracepoint bpf_link. 3328 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use 3329 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see 3330 * bpf_raw_tp_link_attach(). 3331 */ 3332 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT || 3333 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP); 3334 } 3335 3336 /* bpf_link_free is guaranteed to be called from process context */ 3337 static void bpf_link_free(struct bpf_link *link) 3338 { 3339 const struct bpf_link_ops *ops = link->ops; 3340 3341 bpf_link_free_id(link->id); 3342 /* detach BPF program, clean up used resources */ 3343 if (link->prog) 3344 ops->release(link); 3345 if (ops->dealloc_deferred) { 3346 /* 3347 * Schedule BPF link deallocation, which will only then 3348 * trigger putting BPF program refcount. 3349 * If underlying BPF program is sleepable or BPF link's target 3350 * attach hookpoint is sleepable or otherwise requires RCU GPs 3351 * to ensure link and its underlying BPF program is not 3352 * reachable anymore, we need to first wait for RCU tasks 3353 * trace sync, and then go through "classic" RCU grace period. 3354 * 3355 * For tracepoint BPF links, we need to go through SRCU grace 3356 * period wait instead when non-faultable tracepoint is used. We 3357 * don't need to chain SRCU grace period waits, however, for the 3358 * faultable case, since it exclusively uses RCU Tasks Trace. 3359 */ 3360 if (link->sleepable || (link->prog && link->prog->sleepable)) 3361 /* RCU Tasks Trace grace period implies RCU grace period. */ 3362 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3363 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */ 3364 else if (bpf_link_is_tracepoint(link)) 3365 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3366 else 3367 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3368 } else if (ops->dealloc) { 3369 bpf_link_dealloc(link); 3370 } 3371 } 3372 3373 static void bpf_link_put_deferred(struct work_struct *work) 3374 { 3375 struct bpf_link *link = container_of(work, struct bpf_link, work); 3376 3377 bpf_link_free(link); 3378 } 3379 3380 /* bpf_link_put might be called from atomic context. It needs to be called 3381 * from sleepable context in order to acquire sleeping locks during the process. 3382 */ 3383 void bpf_link_put(struct bpf_link *link) 3384 { 3385 if (!atomic64_dec_and_test(&link->refcnt)) 3386 return; 3387 3388 INIT_WORK(&link->work, bpf_link_put_deferred); 3389 schedule_work(&link->work); 3390 } 3391 EXPORT_SYMBOL(bpf_link_put); 3392 3393 static void bpf_link_put_direct(struct bpf_link *link) 3394 { 3395 if (!atomic64_dec_and_test(&link->refcnt)) 3396 return; 3397 bpf_link_free(link); 3398 } 3399 3400 static int bpf_link_release(struct inode *inode, struct file *filp) 3401 { 3402 struct bpf_link *link = filp->private_data; 3403 3404 bpf_link_put_direct(link); 3405 return 0; 3406 } 3407 3408 #ifdef CONFIG_PROC_FS 3409 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3410 #define BPF_MAP_TYPE(_id, _ops) 3411 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3412 static const char *bpf_link_type_strs[] = { 3413 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3414 #include <linux/bpf_types.h> 3415 }; 3416 #undef BPF_PROG_TYPE 3417 #undef BPF_MAP_TYPE 3418 #undef BPF_LINK_TYPE 3419 3420 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3421 { 3422 const struct bpf_link *link = filp->private_data; 3423 const struct bpf_prog *prog = link->prog; 3424 enum bpf_link_type type = link->type; 3425 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3426 3427 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3428 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) 3429 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? 3430 "kretprobe_multi" : "kprobe_multi"); 3431 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) 3432 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ? 3433 "uretprobe_multi" : "uprobe_multi"); 3434 else 3435 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3436 } else { 3437 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3438 seq_printf(m, "link_type:\t<%u>\n", type); 3439 } 3440 seq_printf(m, "link_id:\t%u\n", link->id); 3441 3442 if (prog) { 3443 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3444 seq_printf(m, 3445 "prog_tag:\t%s\n" 3446 "prog_id:\t%u\n", 3447 prog_tag, 3448 prog->aux->id); 3449 } 3450 if (link->ops->show_fdinfo) 3451 link->ops->show_fdinfo(link, m); 3452 } 3453 #endif 3454 3455 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3456 { 3457 struct bpf_link *link = file->private_data; 3458 3459 return link->ops->poll(file, pts); 3460 } 3461 3462 static const struct file_operations bpf_link_fops = { 3463 #ifdef CONFIG_PROC_FS 3464 .show_fdinfo = bpf_link_show_fdinfo, 3465 #endif 3466 .release = bpf_link_release, 3467 .read = bpf_dummy_read, 3468 .write = bpf_dummy_write, 3469 }; 3470 3471 static const struct file_operations bpf_link_fops_poll = { 3472 #ifdef CONFIG_PROC_FS 3473 .show_fdinfo = bpf_link_show_fdinfo, 3474 #endif 3475 .release = bpf_link_release, 3476 .read = bpf_dummy_read, 3477 .write = bpf_dummy_write, 3478 .poll = bpf_link_poll, 3479 }; 3480 3481 static int bpf_link_alloc_id(struct bpf_link *link) 3482 { 3483 int id; 3484 3485 idr_preload(GFP_KERNEL); 3486 spin_lock_bh(&link_idr_lock); 3487 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3488 spin_unlock_bh(&link_idr_lock); 3489 idr_preload_end(); 3490 3491 return id; 3492 } 3493 3494 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3495 * reserving unused FD and allocating ID from link_idr. This is to be paired 3496 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3497 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3498 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3499 * transient state is passed around in struct bpf_link_primer. 3500 * This is preferred way to create and initialize bpf_link, especially when 3501 * there are complicated and expensive operations in between creating bpf_link 3502 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3503 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3504 * expensive (and potentially failing) roll back operations in a rare case 3505 * that file, FD, or ID can't be allocated. 3506 */ 3507 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3508 { 3509 struct file *file; 3510 int fd, id; 3511 3512 fd = get_unused_fd_flags(O_CLOEXEC); 3513 if (fd < 0) 3514 return fd; 3515 3516 3517 id = bpf_link_alloc_id(link); 3518 if (id < 0) { 3519 put_unused_fd(fd); 3520 return id; 3521 } 3522 3523 file = anon_inode_getfile("bpf_link", 3524 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3525 link, O_CLOEXEC); 3526 if (IS_ERR(file)) { 3527 bpf_link_free_id(id); 3528 put_unused_fd(fd); 3529 return PTR_ERR(file); 3530 } 3531 3532 primer->link = link; 3533 primer->file = file; 3534 primer->fd = fd; 3535 primer->id = id; 3536 return 0; 3537 } 3538 3539 int bpf_link_settle(struct bpf_link_primer *primer) 3540 { 3541 /* make bpf_link fetchable by ID */ 3542 spin_lock_bh(&link_idr_lock); 3543 primer->link->id = primer->id; 3544 spin_unlock_bh(&link_idr_lock); 3545 /* make bpf_link fetchable by FD */ 3546 fd_install(primer->fd, primer->file); 3547 /* pass through installed FD */ 3548 return primer->fd; 3549 } 3550 3551 int bpf_link_new_fd(struct bpf_link *link) 3552 { 3553 return anon_inode_getfd("bpf-link", 3554 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3555 link, O_CLOEXEC); 3556 } 3557 3558 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3559 { 3560 CLASS(fd, f)(ufd); 3561 struct bpf_link *link; 3562 3563 if (fd_empty(f)) 3564 return ERR_PTR(-EBADF); 3565 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3566 return ERR_PTR(-EINVAL); 3567 3568 link = fd_file(f)->private_data; 3569 bpf_link_inc(link); 3570 return link; 3571 } 3572 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); 3573 3574 static void bpf_tracing_link_release(struct bpf_link *link) 3575 { 3576 struct bpf_tracing_link *tr_link = 3577 container_of(link, struct bpf_tracing_link, link.link); 3578 3579 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3580 tr_link->trampoline, 3581 tr_link->tgt_prog)); 3582 3583 bpf_trampoline_put(tr_link->trampoline); 3584 3585 /* tgt_prog is NULL if target is a kernel function */ 3586 if (tr_link->tgt_prog) 3587 bpf_prog_put(tr_link->tgt_prog); 3588 } 3589 3590 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3591 { 3592 struct bpf_tracing_link *tr_link = 3593 container_of(link, struct bpf_tracing_link, link.link); 3594 3595 kfree(tr_link); 3596 } 3597 3598 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3599 struct seq_file *seq) 3600 { 3601 struct bpf_tracing_link *tr_link = 3602 container_of(link, struct bpf_tracing_link, link.link); 3603 u32 target_btf_id, target_obj_id; 3604 3605 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3606 &target_obj_id, &target_btf_id); 3607 seq_printf(seq, 3608 "attach_type:\t%d\n" 3609 "target_obj_id:\t%u\n" 3610 "target_btf_id:\t%u\n" 3611 "cookie:\t%llu\n", 3612 link->attach_type, 3613 target_obj_id, 3614 target_btf_id, 3615 tr_link->link.cookie); 3616 } 3617 3618 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3619 struct bpf_link_info *info) 3620 { 3621 struct bpf_tracing_link *tr_link = 3622 container_of(link, struct bpf_tracing_link, link.link); 3623 3624 info->tracing.attach_type = link->attach_type; 3625 info->tracing.cookie = tr_link->link.cookie; 3626 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3627 &info->tracing.target_obj_id, 3628 &info->tracing.target_btf_id); 3629 3630 return 0; 3631 } 3632 3633 static const struct bpf_link_ops bpf_tracing_link_lops = { 3634 .release = bpf_tracing_link_release, 3635 .dealloc = bpf_tracing_link_dealloc, 3636 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3637 .fill_link_info = bpf_tracing_link_fill_link_info, 3638 }; 3639 3640 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3641 int tgt_prog_fd, 3642 u32 btf_id, 3643 u64 bpf_cookie, 3644 enum bpf_attach_type attach_type) 3645 { 3646 struct bpf_link_primer link_primer; 3647 struct bpf_prog *tgt_prog = NULL; 3648 struct bpf_trampoline *tr = NULL; 3649 struct bpf_tracing_link *link; 3650 u64 key = 0; 3651 int err; 3652 3653 switch (prog->type) { 3654 case BPF_PROG_TYPE_TRACING: 3655 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3656 prog->expected_attach_type != BPF_TRACE_FEXIT && 3657 prog->expected_attach_type != BPF_TRACE_FSESSION && 3658 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3659 err = -EINVAL; 3660 goto out_put_prog; 3661 } 3662 break; 3663 case BPF_PROG_TYPE_EXT: 3664 if (prog->expected_attach_type != 0) { 3665 err = -EINVAL; 3666 goto out_put_prog; 3667 } 3668 break; 3669 case BPF_PROG_TYPE_LSM: 3670 if (prog->expected_attach_type != BPF_LSM_MAC) { 3671 err = -EINVAL; 3672 goto out_put_prog; 3673 } 3674 break; 3675 default: 3676 err = -EINVAL; 3677 goto out_put_prog; 3678 } 3679 3680 if (!!tgt_prog_fd != !!btf_id) { 3681 err = -EINVAL; 3682 goto out_put_prog; 3683 } 3684 3685 if (tgt_prog_fd) { 3686 /* 3687 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3688 * part would be changed to implement the same for 3689 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3690 * attach_tracing_prog flag is set. 3691 */ 3692 if (prog->type != BPF_PROG_TYPE_EXT) { 3693 err = -EINVAL; 3694 goto out_put_prog; 3695 } 3696 3697 tgt_prog = bpf_prog_get(tgt_prog_fd); 3698 if (IS_ERR(tgt_prog)) { 3699 err = PTR_ERR(tgt_prog); 3700 tgt_prog = NULL; 3701 goto out_put_prog; 3702 } 3703 3704 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3705 } 3706 3707 if (prog->expected_attach_type == BPF_TRACE_FSESSION) { 3708 struct bpf_fsession_link *fslink; 3709 3710 fslink = kzalloc_obj(*fslink, GFP_USER); 3711 if (fslink) { 3712 bpf_link_init(&fslink->fexit.link, BPF_LINK_TYPE_TRACING, 3713 &bpf_tracing_link_lops, prog, attach_type); 3714 fslink->fexit.cookie = bpf_cookie; 3715 link = &fslink->link; 3716 } else { 3717 link = NULL; 3718 } 3719 } else { 3720 link = kzalloc_obj(*link, GFP_USER); 3721 } 3722 if (!link) { 3723 err = -ENOMEM; 3724 goto out_put_prog; 3725 } 3726 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3727 &bpf_tracing_link_lops, prog, attach_type); 3728 3729 link->link.cookie = bpf_cookie; 3730 3731 mutex_lock(&prog->aux->dst_mutex); 3732 3733 /* There are a few possible cases here: 3734 * 3735 * - if prog->aux->dst_trampoline is set, the program was just loaded 3736 * and not yet attached to anything, so we can use the values stored 3737 * in prog->aux 3738 * 3739 * - if prog->aux->dst_trampoline is NULL, the program has already been 3740 * attached to a target and its initial target was cleared (below) 3741 * 3742 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3743 * target_btf_id using the link_create API. 3744 * 3745 * - if tgt_prog == NULL when this function was called using the old 3746 * raw_tracepoint_open API, and we need a target from prog->aux 3747 * 3748 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3749 * was detached and is going for re-attachment. 3750 * 3751 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3752 * are NULL, then program was already attached and user did not provide 3753 * tgt_prog_fd so we have no way to find out or create trampoline 3754 */ 3755 if (!prog->aux->dst_trampoline && !tgt_prog) { 3756 /* 3757 * Allow re-attach for TRACING and LSM programs. If it's 3758 * currently linked, bpf_trampoline_link_prog will fail. 3759 * EXT programs need to specify tgt_prog_fd, so they 3760 * re-attach in separate code path. 3761 */ 3762 if (prog->type != BPF_PROG_TYPE_TRACING && 3763 prog->type != BPF_PROG_TYPE_LSM) { 3764 err = -EINVAL; 3765 goto out_unlock; 3766 } 3767 /* We can allow re-attach only if we have valid attach_btf. */ 3768 if (!prog->aux->attach_btf) { 3769 err = -EINVAL; 3770 goto out_unlock; 3771 } 3772 btf_id = prog->aux->attach_btf_id; 3773 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3774 } 3775 3776 if (!prog->aux->dst_trampoline || 3777 (key && key != prog->aux->dst_trampoline->key)) { 3778 /* If there is no saved target, or the specified target is 3779 * different from the destination specified at load time, we 3780 * need a new trampoline and a check for compatibility 3781 */ 3782 struct bpf_attach_target_info tgt_info = {}; 3783 3784 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3785 &tgt_info); 3786 if (err) 3787 goto out_unlock; 3788 3789 if (tgt_info.tgt_mod) { 3790 module_put(prog->aux->mod); 3791 prog->aux->mod = tgt_info.tgt_mod; 3792 } 3793 3794 tr = bpf_trampoline_get(key, &tgt_info); 3795 if (!tr) { 3796 err = -ENOMEM; 3797 goto out_unlock; 3798 } 3799 } else { 3800 /* The caller didn't specify a target, or the target was the 3801 * same as the destination supplied during program load. This 3802 * means we can reuse the trampoline and reference from program 3803 * load time, and there is no need to allocate a new one. This 3804 * can only happen once for any program, as the saved values in 3805 * prog->aux are cleared below. 3806 */ 3807 tr = prog->aux->dst_trampoline; 3808 tgt_prog = prog->aux->dst_prog; 3809 } 3810 /* 3811 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true 3812 * freplace prog. Without this check, kprobe_write_ctx=true freplace 3813 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and 3814 * then modify the registers of the kprobe prog's target kernel 3815 * function. 3816 * 3817 * This also blocks the combination of uprobe+freplace, because it is 3818 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe 3819 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by 3820 * the target perf event flags in __perf_event_set_bpf_prog(). 3821 */ 3822 if (prog->type == BPF_PROG_TYPE_EXT && 3823 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) { 3824 err = -EINVAL; 3825 goto out_unlock; 3826 } 3827 3828 err = bpf_link_prime(&link->link.link, &link_primer); 3829 if (err) 3830 goto out_unlock; 3831 3832 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog); 3833 if (err) { 3834 bpf_link_cleanup(&link_primer); 3835 link = NULL; 3836 goto out_unlock; 3837 } 3838 3839 link->tgt_prog = tgt_prog; 3840 link->trampoline = tr; 3841 3842 /* Always clear the trampoline and target prog from prog->aux to make 3843 * sure the original attach destination is not kept alive after a 3844 * program is (re-)attached to another target. 3845 */ 3846 if (prog->aux->dst_prog && 3847 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3848 /* got extra prog ref from syscall, or attaching to different prog */ 3849 bpf_prog_put(prog->aux->dst_prog); 3850 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3851 /* we allocated a new trampoline, so free the old one */ 3852 bpf_trampoline_put(prog->aux->dst_trampoline); 3853 3854 prog->aux->dst_prog = NULL; 3855 prog->aux->dst_trampoline = NULL; 3856 mutex_unlock(&prog->aux->dst_mutex); 3857 3858 return bpf_link_settle(&link_primer); 3859 out_unlock: 3860 if (tr && tr != prog->aux->dst_trampoline) 3861 bpf_trampoline_put(tr); 3862 mutex_unlock(&prog->aux->dst_mutex); 3863 kfree(link); 3864 out_put_prog: 3865 if (tgt_prog_fd && tgt_prog) 3866 bpf_prog_put(tgt_prog); 3867 return err; 3868 } 3869 3870 static void bpf_raw_tp_link_release(struct bpf_link *link) 3871 { 3872 struct bpf_raw_tp_link *raw_tp = 3873 container_of(link, struct bpf_raw_tp_link, link); 3874 3875 bpf_probe_unregister(raw_tp->btp, raw_tp); 3876 bpf_put_raw_tracepoint(raw_tp->btp); 3877 } 3878 3879 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3880 { 3881 struct bpf_raw_tp_link *raw_tp = 3882 container_of(link, struct bpf_raw_tp_link, link); 3883 3884 kfree(raw_tp); 3885 } 3886 3887 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3888 struct seq_file *seq) 3889 { 3890 struct bpf_raw_tp_link *raw_tp_link = 3891 container_of(link, struct bpf_raw_tp_link, link); 3892 3893 seq_printf(seq, 3894 "tp_name:\t%s\n" 3895 "cookie:\t%llu\n", 3896 raw_tp_link->btp->tp->name, 3897 raw_tp_link->cookie); 3898 } 3899 3900 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3901 u32 len) 3902 { 3903 if (ulen >= len + 1) { 3904 if (copy_to_user(ubuf, buf, len + 1)) 3905 return -EFAULT; 3906 } else { 3907 char zero = '\0'; 3908 3909 if (copy_to_user(ubuf, buf, ulen - 1)) 3910 return -EFAULT; 3911 if (put_user(zero, ubuf + ulen - 1)) 3912 return -EFAULT; 3913 return -ENOSPC; 3914 } 3915 3916 return 0; 3917 } 3918 3919 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3920 struct bpf_link_info *info) 3921 { 3922 struct bpf_raw_tp_link *raw_tp_link = 3923 container_of(link, struct bpf_raw_tp_link, link); 3924 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3925 const char *tp_name = raw_tp_link->btp->tp->name; 3926 u32 ulen = info->raw_tracepoint.tp_name_len; 3927 size_t tp_len = strlen(tp_name); 3928 3929 if (!ulen ^ !ubuf) 3930 return -EINVAL; 3931 3932 info->raw_tracepoint.tp_name_len = tp_len + 1; 3933 info->raw_tracepoint.cookie = raw_tp_link->cookie; 3934 3935 if (!ubuf) 3936 return 0; 3937 3938 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3939 } 3940 3941 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3942 .release = bpf_raw_tp_link_release, 3943 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3944 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3945 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3946 }; 3947 3948 #ifdef CONFIG_PERF_EVENTS 3949 struct bpf_perf_link { 3950 struct bpf_link link; 3951 struct file *perf_file; 3952 }; 3953 3954 static void bpf_perf_link_release(struct bpf_link *link) 3955 { 3956 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3957 struct perf_event *event = perf_link->perf_file->private_data; 3958 3959 perf_event_free_bpf_prog(event); 3960 fput(perf_link->perf_file); 3961 } 3962 3963 static void bpf_perf_link_dealloc(struct bpf_link *link) 3964 { 3965 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3966 3967 kfree(perf_link); 3968 } 3969 3970 static int bpf_perf_link_fill_common(const struct perf_event *event, 3971 char __user *uname, u32 *ulenp, 3972 u64 *probe_offset, u64 *probe_addr, 3973 u32 *fd_type, unsigned long *missed) 3974 { 3975 const char *buf; 3976 u32 prog_id, ulen; 3977 size_t len; 3978 int err; 3979 3980 ulen = *ulenp; 3981 if (!ulen ^ !uname) 3982 return -EINVAL; 3983 3984 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3985 probe_offset, probe_addr, missed); 3986 if (err) 3987 return err; 3988 3989 if (buf) { 3990 len = strlen(buf); 3991 *ulenp = len + 1; 3992 } else { 3993 *ulenp = 1; 3994 } 3995 if (!uname) 3996 return 0; 3997 3998 if (buf) { 3999 err = bpf_copy_to_user(uname, buf, ulen, len); 4000 if (err) 4001 return err; 4002 } else { 4003 char zero = '\0'; 4004 4005 if (put_user(zero, uname)) 4006 return -EFAULT; 4007 } 4008 return 0; 4009 } 4010 4011 #ifdef CONFIG_KPROBE_EVENTS 4012 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 4013 struct bpf_link_info *info) 4014 { 4015 unsigned long missed; 4016 char __user *uname; 4017 u64 addr, offset; 4018 u32 ulen, type; 4019 int err; 4020 4021 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 4022 ulen = info->perf_event.kprobe.name_len; 4023 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 4024 &type, &missed); 4025 if (err) 4026 return err; 4027 if (type == BPF_FD_TYPE_KRETPROBE) 4028 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 4029 else 4030 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 4031 info->perf_event.kprobe.name_len = ulen; 4032 info->perf_event.kprobe.offset = offset; 4033 info->perf_event.kprobe.missed = missed; 4034 if (!kallsyms_show_value(current_cred())) 4035 addr = 0; 4036 info->perf_event.kprobe.addr = addr; 4037 info->perf_event.kprobe.cookie = event->bpf_cookie; 4038 return 0; 4039 } 4040 4041 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, 4042 struct seq_file *seq) 4043 { 4044 const char *name; 4045 int err; 4046 u32 prog_id, type; 4047 u64 offset, addr; 4048 unsigned long missed; 4049 4050 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4051 &offset, &addr, &missed); 4052 if (err) 4053 return; 4054 4055 seq_printf(seq, 4056 "name:\t%s\n" 4057 "offset:\t%#llx\n" 4058 "missed:\t%lu\n" 4059 "addr:\t%#llx\n" 4060 "event_type:\t%s\n" 4061 "cookie:\t%llu\n", 4062 name, offset, missed, addr, 4063 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", 4064 event->bpf_cookie); 4065 } 4066 #endif 4067 4068 #ifdef CONFIG_UPROBE_EVENTS 4069 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 4070 struct bpf_link_info *info) 4071 { 4072 u64 ref_ctr_offset, offset; 4073 char __user *uname; 4074 u32 ulen, type; 4075 int err; 4076 4077 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 4078 ulen = info->perf_event.uprobe.name_len; 4079 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, 4080 &type, NULL); 4081 if (err) 4082 return err; 4083 4084 if (type == BPF_FD_TYPE_URETPROBE) 4085 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 4086 else 4087 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 4088 info->perf_event.uprobe.name_len = ulen; 4089 info->perf_event.uprobe.offset = offset; 4090 info->perf_event.uprobe.cookie = event->bpf_cookie; 4091 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; 4092 return 0; 4093 } 4094 4095 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, 4096 struct seq_file *seq) 4097 { 4098 const char *name; 4099 int err; 4100 u32 prog_id, type; 4101 u64 offset, ref_ctr_offset; 4102 unsigned long missed; 4103 4104 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 4105 &offset, &ref_ctr_offset, &missed); 4106 if (err) 4107 return; 4108 4109 seq_printf(seq, 4110 "name:\t%s\n" 4111 "offset:\t%#llx\n" 4112 "ref_ctr_offset:\t%#llx\n" 4113 "event_type:\t%s\n" 4114 "cookie:\t%llu\n", 4115 name, offset, ref_ctr_offset, 4116 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", 4117 event->bpf_cookie); 4118 } 4119 #endif 4120 4121 static int bpf_perf_link_fill_probe(const struct perf_event *event, 4122 struct bpf_link_info *info) 4123 { 4124 #ifdef CONFIG_KPROBE_EVENTS 4125 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4126 return bpf_perf_link_fill_kprobe(event, info); 4127 #endif 4128 #ifdef CONFIG_UPROBE_EVENTS 4129 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4130 return bpf_perf_link_fill_uprobe(event, info); 4131 #endif 4132 return -EOPNOTSUPP; 4133 } 4134 4135 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 4136 struct bpf_link_info *info) 4137 { 4138 char __user *uname; 4139 u32 ulen; 4140 int err; 4141 4142 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 4143 ulen = info->perf_event.tracepoint.name_len; 4144 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 4145 if (err) 4146 return err; 4147 4148 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 4149 info->perf_event.tracepoint.name_len = ulen; 4150 info->perf_event.tracepoint.cookie = event->bpf_cookie; 4151 return 0; 4152 } 4153 4154 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 4155 struct bpf_link_info *info) 4156 { 4157 info->perf_event.event.type = event->attr.type; 4158 info->perf_event.event.config = event->attr.config; 4159 info->perf_event.event.cookie = event->bpf_cookie; 4160 info->perf_event.type = BPF_PERF_EVENT_EVENT; 4161 return 0; 4162 } 4163 4164 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 4165 struct bpf_link_info *info) 4166 { 4167 struct bpf_perf_link *perf_link; 4168 const struct perf_event *event; 4169 4170 perf_link = container_of(link, struct bpf_perf_link, link); 4171 event = perf_get_event(perf_link->perf_file); 4172 if (IS_ERR(event)) 4173 return PTR_ERR(event); 4174 4175 switch (event->prog->type) { 4176 case BPF_PROG_TYPE_PERF_EVENT: 4177 return bpf_perf_link_fill_perf_event(event, info); 4178 case BPF_PROG_TYPE_TRACEPOINT: 4179 return bpf_perf_link_fill_tracepoint(event, info); 4180 case BPF_PROG_TYPE_KPROBE: 4181 return bpf_perf_link_fill_probe(event, info); 4182 default: 4183 return -EOPNOTSUPP; 4184 } 4185 } 4186 4187 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, 4188 struct seq_file *seq) 4189 { 4190 seq_printf(seq, 4191 "type:\t%u\n" 4192 "config:\t%llu\n" 4193 "event_type:\t%s\n" 4194 "cookie:\t%llu\n", 4195 event->attr.type, event->attr.config, 4196 "event", event->bpf_cookie); 4197 } 4198 4199 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, 4200 struct seq_file *seq) 4201 { 4202 int err; 4203 const char *name; 4204 u32 prog_id; 4205 4206 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, 4207 NULL, NULL); 4208 if (err) 4209 return; 4210 4211 seq_printf(seq, 4212 "tp_name:\t%s\n" 4213 "event_type:\t%s\n" 4214 "cookie:\t%llu\n", 4215 name, "tracepoint", event->bpf_cookie); 4216 } 4217 4218 static void bpf_probe_link_show_fdinfo(const struct perf_event *event, 4219 struct seq_file *seq) 4220 { 4221 #ifdef CONFIG_KPROBE_EVENTS 4222 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4223 return bpf_perf_link_fdinfo_kprobe(event, seq); 4224 #endif 4225 4226 #ifdef CONFIG_UPROBE_EVENTS 4227 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4228 return bpf_perf_link_fdinfo_uprobe(event, seq); 4229 #endif 4230 } 4231 4232 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, 4233 struct seq_file *seq) 4234 { 4235 struct bpf_perf_link *perf_link; 4236 const struct perf_event *event; 4237 4238 perf_link = container_of(link, struct bpf_perf_link, link); 4239 event = perf_get_event(perf_link->perf_file); 4240 if (IS_ERR(event)) 4241 return; 4242 4243 switch (event->prog->type) { 4244 case BPF_PROG_TYPE_PERF_EVENT: 4245 return bpf_perf_event_link_show_fdinfo(event, seq); 4246 case BPF_PROG_TYPE_TRACEPOINT: 4247 return bpf_tracepoint_link_show_fdinfo(event, seq); 4248 case BPF_PROG_TYPE_KPROBE: 4249 return bpf_probe_link_show_fdinfo(event, seq); 4250 default: 4251 return; 4252 } 4253 } 4254 4255 static const struct bpf_link_ops bpf_perf_link_lops = { 4256 .release = bpf_perf_link_release, 4257 .dealloc = bpf_perf_link_dealloc, 4258 .fill_link_info = bpf_perf_link_fill_link_info, 4259 .show_fdinfo = bpf_perf_link_show_fdinfo, 4260 }; 4261 4262 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4263 { 4264 struct bpf_link_primer link_primer; 4265 struct bpf_perf_link *link; 4266 struct perf_event *event; 4267 struct file *perf_file; 4268 int err; 4269 4270 if (attr->link_create.flags) 4271 return -EINVAL; 4272 4273 perf_file = perf_event_get(attr->link_create.target_fd); 4274 if (IS_ERR(perf_file)) 4275 return PTR_ERR(perf_file); 4276 4277 link = kzalloc_obj(*link, GFP_USER); 4278 if (!link) { 4279 err = -ENOMEM; 4280 goto out_put_file; 4281 } 4282 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, 4283 attr->link_create.attach_type); 4284 link->perf_file = perf_file; 4285 4286 err = bpf_link_prime(&link->link, &link_primer); 4287 if (err) { 4288 kfree(link); 4289 goto out_put_file; 4290 } 4291 4292 event = perf_file->private_data; 4293 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 4294 if (err) { 4295 bpf_link_cleanup(&link_primer); 4296 goto out_put_file; 4297 } 4298 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 4299 bpf_prog_inc(prog); 4300 4301 return bpf_link_settle(&link_primer); 4302 4303 out_put_file: 4304 fput(perf_file); 4305 return err; 4306 } 4307 #else 4308 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4309 { 4310 return -EOPNOTSUPP; 4311 } 4312 #endif /* CONFIG_PERF_EVENTS */ 4313 4314 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 4315 const char __user *user_tp_name, u64 cookie, 4316 enum bpf_attach_type attach_type) 4317 { 4318 struct bpf_link_primer link_primer; 4319 struct bpf_raw_tp_link *link; 4320 struct bpf_raw_event_map *btp; 4321 const char *tp_name; 4322 char buf[128]; 4323 int err; 4324 4325 switch (prog->type) { 4326 case BPF_PROG_TYPE_TRACING: 4327 case BPF_PROG_TYPE_EXT: 4328 case BPF_PROG_TYPE_LSM: 4329 if (user_tp_name) 4330 /* The attach point for this category of programs 4331 * should be specified via btf_id during program load. 4332 */ 4333 return -EINVAL; 4334 if (prog->type == BPF_PROG_TYPE_TRACING && 4335 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 4336 tp_name = prog->aux->attach_func_name; 4337 break; 4338 } 4339 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); 4340 case BPF_PROG_TYPE_RAW_TRACEPOINT: 4341 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 4342 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 4343 return -EFAULT; 4344 buf[sizeof(buf) - 1] = 0; 4345 tp_name = buf; 4346 break; 4347 default: 4348 return -EINVAL; 4349 } 4350 4351 btp = bpf_get_raw_tracepoint(tp_name); 4352 if (!btp) 4353 return -ENOENT; 4354 4355 if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) { 4356 bpf_put_raw_tracepoint(btp); 4357 return -EINVAL; 4358 } 4359 4360 link = kzalloc_obj(*link, GFP_USER); 4361 if (!link) { 4362 err = -ENOMEM; 4363 goto out_put_btp; 4364 } 4365 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 4366 &bpf_raw_tp_link_lops, prog, attach_type, 4367 tracepoint_is_faultable(btp->tp)); 4368 link->btp = btp; 4369 link->cookie = cookie; 4370 4371 err = bpf_link_prime(&link->link, &link_primer); 4372 if (err) { 4373 kfree(link); 4374 goto out_put_btp; 4375 } 4376 4377 err = bpf_probe_register(link->btp, link); 4378 if (err) { 4379 bpf_link_cleanup(&link_primer); 4380 goto out_put_btp; 4381 } 4382 4383 return bpf_link_settle(&link_primer); 4384 4385 out_put_btp: 4386 bpf_put_raw_tracepoint(btp); 4387 return err; 4388 } 4389 4390 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 4391 4392 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4393 { 4394 struct bpf_prog *prog; 4395 void __user *tp_name; 4396 __u64 cookie; 4397 int fd; 4398 4399 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4400 return -EINVAL; 4401 4402 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4403 if (IS_ERR(prog)) 4404 return PTR_ERR(prog); 4405 4406 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4407 cookie = attr->raw_tracepoint.cookie; 4408 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); 4409 if (fd < 0) 4410 bpf_prog_put(prog); 4411 return fd; 4412 } 4413 4414 static enum bpf_prog_type 4415 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4416 { 4417 switch (attach_type) { 4418 case BPF_CGROUP_INET_INGRESS: 4419 case BPF_CGROUP_INET_EGRESS: 4420 return BPF_PROG_TYPE_CGROUP_SKB; 4421 case BPF_CGROUP_INET_SOCK_CREATE: 4422 case BPF_CGROUP_INET_SOCK_RELEASE: 4423 case BPF_CGROUP_INET4_POST_BIND: 4424 case BPF_CGROUP_INET6_POST_BIND: 4425 return BPF_PROG_TYPE_CGROUP_SOCK; 4426 case BPF_CGROUP_INET4_BIND: 4427 case BPF_CGROUP_INET6_BIND: 4428 case BPF_CGROUP_INET4_CONNECT: 4429 case BPF_CGROUP_INET6_CONNECT: 4430 case BPF_CGROUP_UNIX_CONNECT: 4431 case BPF_CGROUP_INET4_GETPEERNAME: 4432 case BPF_CGROUP_INET6_GETPEERNAME: 4433 case BPF_CGROUP_UNIX_GETPEERNAME: 4434 case BPF_CGROUP_INET4_GETSOCKNAME: 4435 case BPF_CGROUP_INET6_GETSOCKNAME: 4436 case BPF_CGROUP_UNIX_GETSOCKNAME: 4437 case BPF_CGROUP_UDP4_SENDMSG: 4438 case BPF_CGROUP_UDP6_SENDMSG: 4439 case BPF_CGROUP_UNIX_SENDMSG: 4440 case BPF_CGROUP_UDP4_RECVMSG: 4441 case BPF_CGROUP_UDP6_RECVMSG: 4442 case BPF_CGROUP_UNIX_RECVMSG: 4443 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4444 case BPF_CGROUP_SOCK_OPS: 4445 return BPF_PROG_TYPE_SOCK_OPS; 4446 case BPF_CGROUP_DEVICE: 4447 return BPF_PROG_TYPE_CGROUP_DEVICE; 4448 case BPF_SK_MSG_VERDICT: 4449 return BPF_PROG_TYPE_SK_MSG; 4450 case BPF_SK_SKB_STREAM_PARSER: 4451 case BPF_SK_SKB_STREAM_VERDICT: 4452 case BPF_SK_SKB_VERDICT: 4453 return BPF_PROG_TYPE_SK_SKB; 4454 case BPF_LIRC_MODE2: 4455 return BPF_PROG_TYPE_LIRC_MODE2; 4456 case BPF_FLOW_DISSECTOR: 4457 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4458 case BPF_CGROUP_SYSCTL: 4459 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4460 case BPF_CGROUP_GETSOCKOPT: 4461 case BPF_CGROUP_SETSOCKOPT: 4462 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4463 case BPF_TRACE_ITER: 4464 case BPF_TRACE_RAW_TP: 4465 case BPF_TRACE_FENTRY: 4466 case BPF_TRACE_FEXIT: 4467 case BPF_TRACE_FSESSION: 4468 case BPF_MODIFY_RETURN: 4469 return BPF_PROG_TYPE_TRACING; 4470 case BPF_LSM_MAC: 4471 return BPF_PROG_TYPE_LSM; 4472 case BPF_SK_LOOKUP: 4473 return BPF_PROG_TYPE_SK_LOOKUP; 4474 case BPF_XDP: 4475 return BPF_PROG_TYPE_XDP; 4476 case BPF_LSM_CGROUP: 4477 return BPF_PROG_TYPE_LSM; 4478 case BPF_TCX_INGRESS: 4479 case BPF_TCX_EGRESS: 4480 case BPF_NETKIT_PRIMARY: 4481 case BPF_NETKIT_PEER: 4482 return BPF_PROG_TYPE_SCHED_CLS; 4483 default: 4484 return BPF_PROG_TYPE_UNSPEC; 4485 } 4486 } 4487 4488 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4489 enum bpf_attach_type attach_type) 4490 { 4491 enum bpf_prog_type ptype; 4492 4493 switch (prog->type) { 4494 case BPF_PROG_TYPE_CGROUP_SOCK: 4495 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4496 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4497 case BPF_PROG_TYPE_SK_LOOKUP: 4498 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4499 case BPF_PROG_TYPE_CGROUP_SKB: 4500 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4501 /* cg-skb progs can be loaded by unpriv user. 4502 * check permissions at attach time. 4503 */ 4504 return -EPERM; 4505 4506 ptype = attach_type_to_prog_type(attach_type); 4507 if (prog->type != ptype) 4508 return -EINVAL; 4509 4510 return prog->enforce_expected_attach_type && 4511 prog->expected_attach_type != attach_type ? 4512 -EINVAL : 0; 4513 case BPF_PROG_TYPE_EXT: 4514 return 0; 4515 case BPF_PROG_TYPE_NETFILTER: 4516 if (attach_type != BPF_NETFILTER) 4517 return -EINVAL; 4518 return 0; 4519 case BPF_PROG_TYPE_PERF_EVENT: 4520 case BPF_PROG_TYPE_TRACEPOINT: 4521 if (attach_type != BPF_PERF_EVENT) 4522 return -EINVAL; 4523 return 0; 4524 case BPF_PROG_TYPE_KPROBE: 4525 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4526 attach_type != BPF_TRACE_KPROBE_MULTI) 4527 return -EINVAL; 4528 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4529 attach_type != BPF_TRACE_KPROBE_SESSION) 4530 return -EINVAL; 4531 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4532 attach_type != BPF_TRACE_UPROBE_MULTI) 4533 return -EINVAL; 4534 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4535 attach_type != BPF_TRACE_UPROBE_SESSION) 4536 return -EINVAL; 4537 if (attach_type != BPF_PERF_EVENT && 4538 attach_type != BPF_TRACE_KPROBE_MULTI && 4539 attach_type != BPF_TRACE_KPROBE_SESSION && 4540 attach_type != BPF_TRACE_UPROBE_MULTI && 4541 attach_type != BPF_TRACE_UPROBE_SESSION) 4542 return -EINVAL; 4543 return 0; 4544 case BPF_PROG_TYPE_SCHED_CLS: 4545 if (attach_type != BPF_TCX_INGRESS && 4546 attach_type != BPF_TCX_EGRESS && 4547 attach_type != BPF_NETKIT_PRIMARY && 4548 attach_type != BPF_NETKIT_PEER) 4549 return -EINVAL; 4550 return 0; 4551 default: 4552 ptype = attach_type_to_prog_type(attach_type); 4553 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4554 return -EINVAL; 4555 return 0; 4556 } 4557 } 4558 4559 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, 4560 bool check_atype) 4561 { 4562 switch (ptype) { 4563 case BPF_PROG_TYPE_CGROUP_DEVICE: 4564 case BPF_PROG_TYPE_CGROUP_SKB: 4565 case BPF_PROG_TYPE_CGROUP_SOCK: 4566 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4567 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4568 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4569 case BPF_PROG_TYPE_SOCK_OPS: 4570 return true; 4571 case BPF_PROG_TYPE_LSM: 4572 return check_atype ? atype == BPF_LSM_CGROUP : true; 4573 default: 4574 return false; 4575 } 4576 } 4577 4578 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4579 4580 #define BPF_F_ATTACH_MASK_BASE \ 4581 (BPF_F_ALLOW_OVERRIDE | \ 4582 BPF_F_ALLOW_MULTI | \ 4583 BPF_F_REPLACE | \ 4584 BPF_F_PREORDER) 4585 4586 #define BPF_F_ATTACH_MASK_MPROG \ 4587 (BPF_F_REPLACE | \ 4588 BPF_F_BEFORE | \ 4589 BPF_F_AFTER | \ 4590 BPF_F_ID | \ 4591 BPF_F_LINK) 4592 4593 static int bpf_prog_attach(const union bpf_attr *attr) 4594 { 4595 enum bpf_prog_type ptype; 4596 struct bpf_prog *prog; 4597 int ret; 4598 4599 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4600 return -EINVAL; 4601 4602 ptype = attach_type_to_prog_type(attr->attach_type); 4603 if (ptype == BPF_PROG_TYPE_UNSPEC) 4604 return -EINVAL; 4605 if (bpf_mprog_supported(ptype)) { 4606 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4607 return -EINVAL; 4608 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4609 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) 4610 return -EINVAL; 4611 } else { 4612 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4613 return -EINVAL; 4614 if (attr->relative_fd || 4615 attr->expected_revision) 4616 return -EINVAL; 4617 } 4618 4619 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4620 if (IS_ERR(prog)) 4621 return PTR_ERR(prog); 4622 4623 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4624 bpf_prog_put(prog); 4625 return -EINVAL; 4626 } 4627 4628 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { 4629 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4630 goto out; 4631 } 4632 4633 switch (ptype) { 4634 case BPF_PROG_TYPE_SK_SKB: 4635 case BPF_PROG_TYPE_SK_MSG: 4636 ret = sock_map_get_from_fd(attr, prog); 4637 break; 4638 case BPF_PROG_TYPE_LIRC_MODE2: 4639 ret = lirc_prog_attach(attr, prog); 4640 break; 4641 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4642 ret = netns_bpf_prog_attach(attr, prog); 4643 break; 4644 case BPF_PROG_TYPE_SCHED_CLS: 4645 if (attr->attach_type == BPF_TCX_INGRESS || 4646 attr->attach_type == BPF_TCX_EGRESS) 4647 ret = tcx_prog_attach(attr, prog); 4648 else 4649 ret = netkit_prog_attach(attr, prog); 4650 break; 4651 default: 4652 ret = -EINVAL; 4653 } 4654 out: 4655 if (ret) 4656 bpf_prog_put(prog); 4657 return ret; 4658 } 4659 4660 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4661 4662 static int bpf_prog_detach(const union bpf_attr *attr) 4663 { 4664 struct bpf_prog *prog = NULL; 4665 enum bpf_prog_type ptype; 4666 int ret; 4667 4668 if (CHECK_ATTR(BPF_PROG_DETACH)) 4669 return -EINVAL; 4670 4671 ptype = attach_type_to_prog_type(attr->attach_type); 4672 if (bpf_mprog_supported(ptype)) { 4673 if (ptype == BPF_PROG_TYPE_UNSPEC) 4674 return -EINVAL; 4675 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4676 return -EINVAL; 4677 if (attr->attach_bpf_fd) { 4678 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4679 if (IS_ERR(prog)) 4680 return PTR_ERR(prog); 4681 } else if (!bpf_mprog_detach_empty(ptype)) { 4682 return -EPERM; 4683 } 4684 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4685 if (attr->attach_flags || attr->relative_fd) 4686 return -EINVAL; 4687 } else if (attr->attach_flags || 4688 attr->relative_fd || 4689 attr->expected_revision) { 4690 return -EINVAL; 4691 } 4692 4693 switch (ptype) { 4694 case BPF_PROG_TYPE_SK_MSG: 4695 case BPF_PROG_TYPE_SK_SKB: 4696 ret = sock_map_prog_detach(attr, ptype); 4697 break; 4698 case BPF_PROG_TYPE_LIRC_MODE2: 4699 ret = lirc_prog_detach(attr); 4700 break; 4701 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4702 ret = netns_bpf_prog_detach(attr, ptype); 4703 break; 4704 case BPF_PROG_TYPE_CGROUP_DEVICE: 4705 case BPF_PROG_TYPE_CGROUP_SKB: 4706 case BPF_PROG_TYPE_CGROUP_SOCK: 4707 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4708 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4709 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4710 case BPF_PROG_TYPE_SOCK_OPS: 4711 case BPF_PROG_TYPE_LSM: 4712 ret = cgroup_bpf_prog_detach(attr, ptype); 4713 break; 4714 case BPF_PROG_TYPE_SCHED_CLS: 4715 if (attr->attach_type == BPF_TCX_INGRESS || 4716 attr->attach_type == BPF_TCX_EGRESS) 4717 ret = tcx_prog_detach(attr, prog); 4718 else 4719 ret = netkit_prog_detach(attr, prog); 4720 break; 4721 default: 4722 ret = -EINVAL; 4723 } 4724 4725 if (prog) 4726 bpf_prog_put(prog); 4727 return ret; 4728 } 4729 4730 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4731 4732 static int bpf_prog_query(const union bpf_attr *attr, 4733 union bpf_attr __user *uattr, u32 uattr_size) 4734 { 4735 if (!bpf_net_capable()) 4736 return -EPERM; 4737 if (CHECK_ATTR(BPF_PROG_QUERY)) 4738 return -EINVAL; 4739 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4740 return -EINVAL; 4741 4742 switch (attr->query.attach_type) { 4743 case BPF_CGROUP_INET_INGRESS: 4744 case BPF_CGROUP_INET_EGRESS: 4745 case BPF_CGROUP_INET_SOCK_CREATE: 4746 case BPF_CGROUP_INET_SOCK_RELEASE: 4747 case BPF_CGROUP_INET4_BIND: 4748 case BPF_CGROUP_INET6_BIND: 4749 case BPF_CGROUP_INET4_POST_BIND: 4750 case BPF_CGROUP_INET6_POST_BIND: 4751 case BPF_CGROUP_INET4_CONNECT: 4752 case BPF_CGROUP_INET6_CONNECT: 4753 case BPF_CGROUP_UNIX_CONNECT: 4754 case BPF_CGROUP_INET4_GETPEERNAME: 4755 case BPF_CGROUP_INET6_GETPEERNAME: 4756 case BPF_CGROUP_UNIX_GETPEERNAME: 4757 case BPF_CGROUP_INET4_GETSOCKNAME: 4758 case BPF_CGROUP_INET6_GETSOCKNAME: 4759 case BPF_CGROUP_UNIX_GETSOCKNAME: 4760 case BPF_CGROUP_UDP4_SENDMSG: 4761 case BPF_CGROUP_UDP6_SENDMSG: 4762 case BPF_CGROUP_UNIX_SENDMSG: 4763 case BPF_CGROUP_UDP4_RECVMSG: 4764 case BPF_CGROUP_UDP6_RECVMSG: 4765 case BPF_CGROUP_UNIX_RECVMSG: 4766 case BPF_CGROUP_SOCK_OPS: 4767 case BPF_CGROUP_DEVICE: 4768 case BPF_CGROUP_SYSCTL: 4769 case BPF_CGROUP_GETSOCKOPT: 4770 case BPF_CGROUP_SETSOCKOPT: 4771 case BPF_LSM_CGROUP: 4772 return cgroup_bpf_prog_query(attr, uattr, uattr_size); 4773 case BPF_LIRC_MODE2: 4774 return lirc_prog_query(attr, uattr); 4775 case BPF_FLOW_DISSECTOR: 4776 case BPF_SK_LOOKUP: 4777 return netns_bpf_prog_query(attr, uattr); 4778 case BPF_SK_SKB_STREAM_PARSER: 4779 case BPF_SK_SKB_STREAM_VERDICT: 4780 case BPF_SK_MSG_VERDICT: 4781 case BPF_SK_SKB_VERDICT: 4782 return sock_map_bpf_prog_query(attr, uattr); 4783 case BPF_TCX_INGRESS: 4784 case BPF_TCX_EGRESS: 4785 return tcx_prog_query(attr, uattr); 4786 case BPF_NETKIT_PRIMARY: 4787 case BPF_NETKIT_PEER: 4788 return netkit_prog_query(attr, uattr); 4789 default: 4790 return -EINVAL; 4791 } 4792 } 4793 4794 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4795 4796 static int bpf_prog_test_run(const union bpf_attr *attr, 4797 union bpf_attr __user *uattr) 4798 { 4799 struct bpf_prog *prog; 4800 int ret = -ENOTSUPP; 4801 4802 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4803 return -EINVAL; 4804 4805 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4806 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4807 return -EINVAL; 4808 4809 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4810 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4811 return -EINVAL; 4812 4813 prog = bpf_prog_get(attr->test.prog_fd); 4814 if (IS_ERR(prog)) 4815 return PTR_ERR(prog); 4816 4817 if (prog->aux->ops->test_run) 4818 ret = prog->aux->ops->test_run(prog, attr, uattr); 4819 4820 bpf_prog_put(prog); 4821 return ret; 4822 } 4823 4824 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4825 4826 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4827 union bpf_attr __user *uattr, 4828 struct idr *idr, 4829 spinlock_t *lock) 4830 { 4831 u32 next_id = attr->start_id; 4832 int err = 0; 4833 4834 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4835 return -EINVAL; 4836 4837 if (!capable(CAP_SYS_ADMIN)) 4838 return -EPERM; 4839 4840 next_id++; 4841 spin_lock_bh(lock); 4842 if (!idr_get_next(idr, &next_id)) 4843 err = -ENOENT; 4844 spin_unlock_bh(lock); 4845 4846 if (!err) 4847 err = put_user(next_id, &uattr->next_id); 4848 4849 return err; 4850 } 4851 4852 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4853 { 4854 struct bpf_map *map; 4855 4856 spin_lock_bh(&map_idr_lock); 4857 again: 4858 map = idr_get_next(&map_idr, id); 4859 if (map) { 4860 map = __bpf_map_inc_not_zero(map, false); 4861 if (IS_ERR(map)) { 4862 (*id)++; 4863 goto again; 4864 } 4865 } 4866 spin_unlock_bh(&map_idr_lock); 4867 4868 return map; 4869 } 4870 4871 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4872 { 4873 struct bpf_prog *prog; 4874 4875 spin_lock_bh(&prog_idr_lock); 4876 again: 4877 prog = idr_get_next(&prog_idr, id); 4878 if (prog) { 4879 prog = bpf_prog_inc_not_zero(prog); 4880 if (IS_ERR(prog)) { 4881 (*id)++; 4882 goto again; 4883 } 4884 } 4885 spin_unlock_bh(&prog_idr_lock); 4886 4887 return prog; 4888 } 4889 4890 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4891 4892 struct bpf_prog *bpf_prog_by_id(u32 id) 4893 { 4894 struct bpf_prog *prog; 4895 4896 if (!id) 4897 return ERR_PTR(-ENOENT); 4898 4899 spin_lock_bh(&prog_idr_lock); 4900 prog = idr_find(&prog_idr, id); 4901 if (prog) 4902 prog = bpf_prog_inc_not_zero(prog); 4903 else 4904 prog = ERR_PTR(-ENOENT); 4905 spin_unlock_bh(&prog_idr_lock); 4906 return prog; 4907 } 4908 4909 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4910 { 4911 struct bpf_prog *prog; 4912 u32 id = attr->prog_id; 4913 int fd; 4914 4915 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4916 return -EINVAL; 4917 4918 if (!capable(CAP_SYS_ADMIN)) 4919 return -EPERM; 4920 4921 prog = bpf_prog_by_id(id); 4922 if (IS_ERR(prog)) 4923 return PTR_ERR(prog); 4924 4925 fd = bpf_prog_new_fd(prog); 4926 if (fd < 0) 4927 bpf_prog_put(prog); 4928 4929 return fd; 4930 } 4931 4932 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4933 4934 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4935 { 4936 struct bpf_map *map; 4937 u32 id = attr->map_id; 4938 int f_flags; 4939 int fd; 4940 4941 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4942 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4943 return -EINVAL; 4944 4945 if (!capable(CAP_SYS_ADMIN)) 4946 return -EPERM; 4947 4948 f_flags = bpf_get_file_flag(attr->open_flags); 4949 if (f_flags < 0) 4950 return f_flags; 4951 4952 spin_lock_bh(&map_idr_lock); 4953 map = idr_find(&map_idr, id); 4954 if (map) 4955 map = __bpf_map_inc_not_zero(map, true); 4956 else 4957 map = ERR_PTR(-ENOENT); 4958 spin_unlock_bh(&map_idr_lock); 4959 4960 if (IS_ERR(map)) 4961 return PTR_ERR(map); 4962 4963 fd = bpf_map_new_fd(map, f_flags); 4964 if (fd < 0) 4965 bpf_map_put_with_uref(map); 4966 4967 return fd; 4968 } 4969 4970 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4971 unsigned long addr, u32 *off, 4972 u32 *type) 4973 { 4974 const struct bpf_map *map; 4975 int i; 4976 4977 mutex_lock(&prog->aux->used_maps_mutex); 4978 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4979 map = prog->aux->used_maps[i]; 4980 if (map == (void *)addr) { 4981 *type = BPF_PSEUDO_MAP_FD; 4982 goto out; 4983 } 4984 if (!map->ops->map_direct_value_meta) 4985 continue; 4986 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4987 *type = BPF_PSEUDO_MAP_VALUE; 4988 goto out; 4989 } 4990 } 4991 map = NULL; 4992 4993 out: 4994 mutex_unlock(&prog->aux->used_maps_mutex); 4995 return map; 4996 } 4997 4998 static void prepare_dump_pseudo_call(struct bpf_insn *insn) 4999 { 5000 s32 call_off = insn->imm; 5001 5002 /* 5003 * BPF_CALL_ARGS only exists for interpreter fallback. 5004 * 1. For interpreter (BPF_CALL_ARGS): insn->off is the index of 5005 * interpreters_args array, so here using bpf_call_args_imm() 5006 * to get the real address offset. 5007 * 2. For JIT (BPF_CALL): insn->off is the subprog id. 5008 */ 5009 if (insn->code == (BPF_JMP | BPF_CALL_ARGS)) 5010 insn->imm = bpf_call_args_imm(insn->off); 5011 else 5012 insn->imm = insn->off; 5013 5014 /* Avoid dumping a truncated and misleading pc-relative offset. */ 5015 if (call_off > S16_MAX || call_off < S16_MIN) 5016 insn->off = 0; 5017 else 5018 insn->off = call_off; 5019 } 5020 5021 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 5022 const struct cred *f_cred) 5023 { 5024 const struct bpf_map *map; 5025 struct bpf_insn *insns; 5026 u32 off, type; 5027 u64 imm; 5028 u8 code; 5029 int i; 5030 5031 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 5032 GFP_USER); 5033 if (!insns) 5034 return insns; 5035 5036 for (i = 0; i < prog->len; i++) { 5037 code = insns[i].code; 5038 5039 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 5040 insns[i].code = BPF_JMP | BPF_CALL; 5041 insns[i].imm = BPF_FUNC_tail_call; 5042 /* fall-through */ 5043 } 5044 if (code == (BPF_JMP | BPF_CALL) || 5045 code == (BPF_JMP | BPF_CALL_ARGS)) { 5046 /* Restore the legacy xlated dump layout. */ 5047 if (insns[i].src_reg == BPF_PSEUDO_CALL) 5048 prepare_dump_pseudo_call(&insns[i]); 5049 if (code == (BPF_JMP | BPF_CALL_ARGS)) 5050 insns[i].code = BPF_JMP | BPF_CALL; 5051 if (!bpf_dump_raw_ok(f_cred)) 5052 insns[i].imm = 0; 5053 continue; 5054 } 5055 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 5056 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 5057 continue; 5058 } 5059 5060 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 5061 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 5062 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 5063 continue; 5064 } 5065 5066 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 5067 continue; 5068 5069 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 5070 map = bpf_map_from_imm(prog, imm, &off, &type); 5071 if (map) { 5072 insns[i].src_reg = type; 5073 insns[i].imm = map->id; 5074 insns[i + 1].imm = off; 5075 continue; 5076 } 5077 } 5078 5079 return insns; 5080 } 5081 5082 static int set_info_rec_size(struct bpf_prog_info *info) 5083 { 5084 /* 5085 * Ensure info.*_rec_size is the same as kernel expected size 5086 * 5087 * or 5088 * 5089 * Only allow zero *_rec_size if both _rec_size and _cnt are 5090 * zero. In this case, the kernel will set the expected 5091 * _rec_size back to the info. 5092 */ 5093 5094 if ((info->nr_func_info || info->func_info_rec_size) && 5095 info->func_info_rec_size != sizeof(struct bpf_func_info)) 5096 return -EINVAL; 5097 5098 if ((info->nr_line_info || info->line_info_rec_size) && 5099 info->line_info_rec_size != sizeof(struct bpf_line_info)) 5100 return -EINVAL; 5101 5102 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 5103 info->jited_line_info_rec_size != sizeof(__u64)) 5104 return -EINVAL; 5105 5106 info->func_info_rec_size = sizeof(struct bpf_func_info); 5107 info->line_info_rec_size = sizeof(struct bpf_line_info); 5108 info->jited_line_info_rec_size = sizeof(__u64); 5109 5110 return 0; 5111 } 5112 5113 static int bpf_prog_get_info_by_fd(struct file *file, 5114 struct bpf_prog *prog, 5115 const union bpf_attr *attr, 5116 union bpf_attr __user *uattr) 5117 { 5118 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5119 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 5120 struct bpf_prog_info info; 5121 u32 info_len = attr->info.info_len; 5122 struct bpf_prog_kstats stats; 5123 char __user *uinsns; 5124 u32 ulen; 5125 int err; 5126 5127 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5128 if (err) 5129 return err; 5130 info_len = min_t(u32, sizeof(info), info_len); 5131 5132 memset(&info, 0, sizeof(info)); 5133 if (copy_from_user(&info, uinfo, info_len)) 5134 return -EFAULT; 5135 5136 info.type = prog->type; 5137 info.id = prog->aux->id; 5138 info.load_time = prog->aux->load_time; 5139 info.created_by_uid = from_kuid_munged(current_user_ns(), 5140 prog->aux->user->uid); 5141 info.gpl_compatible = prog->gpl_compatible; 5142 5143 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 5144 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 5145 5146 mutex_lock(&prog->aux->used_maps_mutex); 5147 ulen = info.nr_map_ids; 5148 info.nr_map_ids = prog->aux->used_map_cnt; 5149 ulen = min_t(u32, info.nr_map_ids, ulen); 5150 if (ulen) { 5151 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 5152 u32 i; 5153 5154 for (i = 0; i < ulen; i++) 5155 if (put_user(prog->aux->used_maps[i]->id, 5156 &user_map_ids[i])) { 5157 mutex_unlock(&prog->aux->used_maps_mutex); 5158 return -EFAULT; 5159 } 5160 } 5161 mutex_unlock(&prog->aux->used_maps_mutex); 5162 5163 err = set_info_rec_size(&info); 5164 if (err) 5165 return err; 5166 5167 bpf_prog_get_stats(prog, &stats); 5168 info.run_time_ns = stats.nsecs; 5169 info.run_cnt = stats.cnt; 5170 info.recursion_misses = stats.misses; 5171 5172 info.verified_insns = prog->aux->verified_insns; 5173 if (prog->aux->btf) 5174 info.btf_id = btf_obj_id(prog->aux->btf); 5175 5176 if (!bpf_capable()) { 5177 info.jited_prog_len = 0; 5178 info.xlated_prog_len = 0; 5179 info.nr_jited_ksyms = 0; 5180 info.nr_jited_func_lens = 0; 5181 info.nr_func_info = 0; 5182 info.nr_line_info = 0; 5183 info.nr_jited_line_info = 0; 5184 goto done; 5185 } 5186 5187 ulen = info.xlated_prog_len; 5188 info.xlated_prog_len = bpf_prog_insn_size(prog); 5189 if (info.xlated_prog_len && ulen) { 5190 struct bpf_insn *insns_sanitized; 5191 bool fault; 5192 5193 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) { 5194 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 5195 if (!insns_sanitized) 5196 return -ENOMEM; 5197 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 5198 ulen = min_t(u32, info.xlated_prog_len, ulen); 5199 fault = copy_to_user(uinsns, insns_sanitized, ulen); 5200 kfree(insns_sanitized); 5201 if (fault) 5202 return -EFAULT; 5203 } else { 5204 info.xlated_prog_insns = 0; 5205 } 5206 } 5207 5208 if (bpf_prog_is_offloaded(prog->aux)) { 5209 err = bpf_prog_offload_info_fill(&info, prog); 5210 if (err) 5211 return err; 5212 goto done; 5213 } 5214 5215 /* NOTE: the following code is supposed to be skipped for offload. 5216 * bpf_prog_offload_info_fill() is the place to fill similar fields 5217 * for offload. 5218 */ 5219 ulen = info.jited_prog_len; 5220 if (prog->aux->func_cnt) { 5221 u32 i; 5222 5223 info.jited_prog_len = 0; 5224 for (i = 0; i < prog->aux->func_cnt; i++) 5225 info.jited_prog_len += prog->aux->func[i]->jited_len; 5226 } else { 5227 info.jited_prog_len = prog->jited_len; 5228 } 5229 5230 if (info.jited_prog_len && ulen) { 5231 if (bpf_dump_raw_ok(file->f_cred)) { 5232 uinsns = u64_to_user_ptr(info.jited_prog_insns); 5233 ulen = min_t(u32, info.jited_prog_len, ulen); 5234 5235 /* for multi-function programs, copy the JITed 5236 * instructions for all the functions 5237 */ 5238 if (prog->aux->func_cnt) { 5239 u32 len, free, i; 5240 u8 *img; 5241 5242 free = ulen; 5243 for (i = 0; i < prog->aux->func_cnt; i++) { 5244 len = prog->aux->func[i]->jited_len; 5245 len = min_t(u32, len, free); 5246 img = (u8 *) prog->aux->func[i]->bpf_func; 5247 if (copy_to_user(uinsns, img, len)) 5248 return -EFAULT; 5249 uinsns += len; 5250 free -= len; 5251 if (!free) 5252 break; 5253 } 5254 } else { 5255 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 5256 return -EFAULT; 5257 } 5258 } else { 5259 info.jited_prog_insns = 0; 5260 } 5261 } 5262 5263 ulen = info.nr_jited_ksyms; 5264 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 5265 if (ulen) { 5266 if (bpf_dump_raw_ok(file->f_cred)) { 5267 unsigned long ksym_addr; 5268 u64 __user *user_ksyms; 5269 u32 i; 5270 5271 /* copy the address of the kernel symbol 5272 * corresponding to each function 5273 */ 5274 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 5275 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 5276 if (prog->aux->func_cnt) { 5277 for (i = 0; i < ulen; i++) { 5278 ksym_addr = (unsigned long) 5279 prog->aux->func[i]->bpf_func; 5280 if (put_user((u64) ksym_addr, 5281 &user_ksyms[i])) 5282 return -EFAULT; 5283 } 5284 } else { 5285 ksym_addr = (unsigned long) prog->bpf_func; 5286 if (put_user((u64) ksym_addr, &user_ksyms[0])) 5287 return -EFAULT; 5288 } 5289 } else { 5290 info.jited_ksyms = 0; 5291 } 5292 } 5293 5294 ulen = info.nr_jited_func_lens; 5295 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 5296 if (ulen) { 5297 if (bpf_dump_raw_ok(file->f_cred)) { 5298 u32 __user *user_lens; 5299 u32 func_len, i; 5300 5301 /* copy the JITed image lengths for each function */ 5302 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 5303 user_lens = u64_to_user_ptr(info.jited_func_lens); 5304 if (prog->aux->func_cnt) { 5305 for (i = 0; i < ulen; i++) { 5306 func_len = 5307 prog->aux->func[i]->jited_len; 5308 if (put_user(func_len, &user_lens[i])) 5309 return -EFAULT; 5310 } 5311 } else { 5312 func_len = prog->jited_len; 5313 if (put_user(func_len, &user_lens[0])) 5314 return -EFAULT; 5315 } 5316 } else { 5317 info.jited_func_lens = 0; 5318 } 5319 } 5320 5321 info.attach_btf_id = prog->aux->attach_btf_id; 5322 if (attach_btf) 5323 info.attach_btf_obj_id = btf_obj_id(attach_btf); 5324 5325 ulen = info.nr_func_info; 5326 info.nr_func_info = prog->aux->func_info_cnt; 5327 if (info.nr_func_info && ulen) { 5328 char __user *user_finfo; 5329 5330 user_finfo = u64_to_user_ptr(info.func_info); 5331 ulen = min_t(u32, info.nr_func_info, ulen); 5332 if (copy_to_user(user_finfo, prog->aux->func_info, 5333 info.func_info_rec_size * ulen)) 5334 return -EFAULT; 5335 } 5336 5337 ulen = info.nr_line_info; 5338 info.nr_line_info = prog->aux->nr_linfo; 5339 if (info.nr_line_info && ulen) { 5340 __u8 __user *user_linfo; 5341 5342 user_linfo = u64_to_user_ptr(info.line_info); 5343 ulen = min_t(u32, info.nr_line_info, ulen); 5344 if (copy_to_user(user_linfo, prog->aux->linfo, 5345 info.line_info_rec_size * ulen)) 5346 return -EFAULT; 5347 } 5348 5349 ulen = info.nr_jited_line_info; 5350 if (prog->aux->jited_linfo) 5351 info.nr_jited_line_info = prog->aux->nr_linfo; 5352 else 5353 info.nr_jited_line_info = 0; 5354 if (info.nr_jited_line_info && ulen) { 5355 if (bpf_dump_raw_ok(file->f_cred)) { 5356 unsigned long line_addr; 5357 __u64 __user *user_linfo; 5358 u32 i; 5359 5360 user_linfo = u64_to_user_ptr(info.jited_line_info); 5361 ulen = min_t(u32, info.nr_jited_line_info, ulen); 5362 for (i = 0; i < ulen; i++) { 5363 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 5364 if (put_user((__u64)line_addr, &user_linfo[i])) 5365 return -EFAULT; 5366 } 5367 } else { 5368 info.jited_line_info = 0; 5369 } 5370 } 5371 5372 ulen = info.nr_prog_tags; 5373 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 5374 if (ulen) { 5375 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 5376 u32 i; 5377 5378 user_prog_tags = u64_to_user_ptr(info.prog_tags); 5379 ulen = min_t(u32, info.nr_prog_tags, ulen); 5380 if (prog->aux->func_cnt) { 5381 for (i = 0; i < ulen; i++) { 5382 if (copy_to_user(user_prog_tags[i], 5383 prog->aux->func[i]->tag, 5384 BPF_TAG_SIZE)) 5385 return -EFAULT; 5386 } 5387 } else { 5388 if (copy_to_user(user_prog_tags[0], 5389 prog->tag, BPF_TAG_SIZE)) 5390 return -EFAULT; 5391 } 5392 } 5393 5394 done: 5395 if (copy_to_user(uinfo, &info, info_len) || 5396 put_user(info_len, &uattr->info.info_len)) 5397 return -EFAULT; 5398 5399 return 0; 5400 } 5401 5402 static int bpf_map_get_info_by_fd(struct file *file, 5403 struct bpf_map *map, 5404 const union bpf_attr *attr, 5405 union bpf_attr __user *uattr) 5406 { 5407 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5408 struct bpf_map_info info; 5409 u32 info_len = attr->info.info_len; 5410 int err; 5411 5412 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5413 if (err) 5414 return err; 5415 info_len = min_t(u32, sizeof(info), info_len); 5416 5417 memset(&info, 0, sizeof(info)); 5418 if (copy_from_user(&info, uinfo, info_len)) 5419 return -EFAULT; 5420 5421 info.type = map->map_type; 5422 info.id = map->id; 5423 info.key_size = map->key_size; 5424 info.value_size = map->value_size; 5425 info.max_entries = map->max_entries; 5426 info.map_flags = map->map_flags; 5427 info.map_extra = map->map_extra; 5428 memcpy(info.name, map->name, sizeof(map->name)); 5429 5430 if (map->btf) { 5431 info.btf_id = btf_obj_id(map->btf); 5432 info.btf_key_type_id = map->btf_key_type_id; 5433 info.btf_value_type_id = map->btf_value_type_id; 5434 } 5435 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 5436 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 5437 bpf_map_struct_ops_info_fill(&info, map); 5438 5439 if (bpf_map_is_offloaded(map)) { 5440 err = bpf_map_offload_info_fill(&info, map); 5441 if (err) 5442 return err; 5443 } 5444 5445 if (info.hash) { 5446 char __user *uhash = u64_to_user_ptr(info.hash); 5447 5448 if (!map->ops->map_get_hash) 5449 return -EINVAL; 5450 if (info.hash_size != sizeof(map->sha)) 5451 return -EINVAL; 5452 if (!READ_ONCE(map->frozen)) 5453 return -EPERM; 5454 5455 err = map->ops->map_get_hash(map); 5456 if (err != 0) 5457 return err; 5458 5459 if (copy_to_user(uhash, map->sha, sizeof(map->sha)) != 0) 5460 return -EFAULT; 5461 } else if (info.hash_size) { 5462 return -EINVAL; 5463 } 5464 5465 if (copy_to_user(uinfo, &info, info_len) || 5466 put_user(info_len, &uattr->info.info_len)) 5467 return -EFAULT; 5468 5469 return 0; 5470 } 5471 5472 static int bpf_btf_get_info_by_fd(struct file *file, 5473 struct btf *btf, 5474 const union bpf_attr *attr, 5475 union bpf_attr __user *uattr) 5476 { 5477 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5478 u32 info_len = attr->info.info_len; 5479 int err; 5480 5481 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5482 if (err) 5483 return err; 5484 5485 return btf_get_info_by_fd(btf, attr, uattr); 5486 } 5487 5488 static int bpf_link_get_info_by_fd(struct file *file, 5489 struct bpf_link *link, 5490 const union bpf_attr *attr, 5491 union bpf_attr __user *uattr) 5492 { 5493 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5494 struct bpf_link_info info; 5495 u32 info_len = attr->info.info_len; 5496 int err; 5497 5498 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5499 if (err) 5500 return err; 5501 info_len = min_t(u32, sizeof(info), info_len); 5502 5503 memset(&info, 0, sizeof(info)); 5504 if (copy_from_user(&info, uinfo, info_len)) 5505 return -EFAULT; 5506 5507 info.type = link->type; 5508 info.id = link->id; 5509 if (link->prog) 5510 info.prog_id = link->prog->aux->id; 5511 5512 if (link->ops->fill_link_info) { 5513 err = link->ops->fill_link_info(link, &info); 5514 if (err) 5515 return err; 5516 } 5517 5518 if (copy_to_user(uinfo, &info, info_len) || 5519 put_user(info_len, &uattr->info.info_len)) 5520 return -EFAULT; 5521 5522 return 0; 5523 } 5524 5525 5526 static int token_get_info_by_fd(struct file *file, 5527 struct bpf_token *token, 5528 const union bpf_attr *attr, 5529 union bpf_attr __user *uattr) 5530 { 5531 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5532 u32 info_len = attr->info.info_len; 5533 int err; 5534 5535 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5536 if (err) 5537 return err; 5538 return bpf_token_get_info_by_fd(token, attr, uattr); 5539 } 5540 5541 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5542 5543 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5544 union bpf_attr __user *uattr) 5545 { 5546 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5547 return -EINVAL; 5548 5549 CLASS(fd, f)(attr->info.bpf_fd); 5550 if (fd_empty(f)) 5551 return -EBADFD; 5552 5553 if (fd_file(f)->f_op == &bpf_prog_fops) 5554 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5555 uattr); 5556 else if (fd_file(f)->f_op == &bpf_map_fops) 5557 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5558 uattr); 5559 else if (fd_file(f)->f_op == &btf_fops) 5560 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5561 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5562 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5563 attr, uattr); 5564 else if (fd_file(f)->f_op == &bpf_token_fops) 5565 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5566 attr, uattr); 5567 return -EINVAL; 5568 } 5569 5570 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5571 5572 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log) 5573 { 5574 struct bpf_token *token = NULL; 5575 5576 if (CHECK_ATTR(BPF_BTF_LOAD)) 5577 return -EINVAL; 5578 5579 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5580 return -EINVAL; 5581 5582 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5583 token = bpf_token_get_from_fd(attr->btf_token_fd); 5584 if (IS_ERR(token)) 5585 return PTR_ERR(token); 5586 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5587 bpf_token_put(token); 5588 token = NULL; 5589 } 5590 } 5591 5592 if (!bpf_token_capable(token, CAP_BPF)) { 5593 bpf_token_put(token); 5594 return -EPERM; 5595 } 5596 5597 bpf_token_put(token); 5598 5599 return btf_new_fd(attr, uattr, attr_log); 5600 } 5601 5602 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd 5603 5604 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5605 { 5606 struct bpf_token *token = NULL; 5607 5608 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5609 return -EINVAL; 5610 5611 if (attr->open_flags & ~BPF_F_TOKEN_FD) 5612 return -EINVAL; 5613 5614 if (attr->open_flags & BPF_F_TOKEN_FD) { 5615 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); 5616 if (IS_ERR(token)) 5617 return PTR_ERR(token); 5618 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { 5619 bpf_token_put(token); 5620 token = NULL; 5621 } 5622 } 5623 5624 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { 5625 bpf_token_put(token); 5626 return -EPERM; 5627 } 5628 5629 bpf_token_put(token); 5630 5631 return btf_get_fd_by_id(attr->btf_id); 5632 } 5633 5634 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5635 union bpf_attr __user *uattr, 5636 u32 prog_id, u32 fd_type, 5637 const char *buf, u64 probe_offset, 5638 u64 probe_addr) 5639 { 5640 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5641 u32 len = buf ? strlen(buf) : 0, input_len; 5642 int err = 0; 5643 5644 if (put_user(len, &uattr->task_fd_query.buf_len)) 5645 return -EFAULT; 5646 input_len = attr->task_fd_query.buf_len; 5647 if (input_len && ubuf) { 5648 if (!len) { 5649 /* nothing to copy, just make ubuf NULL terminated */ 5650 char zero = '\0'; 5651 5652 if (put_user(zero, ubuf)) 5653 return -EFAULT; 5654 } else { 5655 err = bpf_copy_to_user(ubuf, buf, input_len, len); 5656 if (err == -EFAULT) 5657 return err; 5658 } 5659 } 5660 5661 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5662 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5663 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5664 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5665 return -EFAULT; 5666 5667 return err; 5668 } 5669 5670 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5671 5672 static int bpf_task_fd_query(const union bpf_attr *attr, 5673 union bpf_attr __user *uattr) 5674 { 5675 pid_t pid = attr->task_fd_query.pid; 5676 u32 fd = attr->task_fd_query.fd; 5677 const struct perf_event *event; 5678 struct task_struct *task; 5679 struct file *file; 5680 int err; 5681 5682 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5683 return -EINVAL; 5684 5685 if (!capable(CAP_SYS_ADMIN)) 5686 return -EPERM; 5687 5688 if (attr->task_fd_query.flags != 0) 5689 return -EINVAL; 5690 5691 rcu_read_lock(); 5692 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5693 rcu_read_unlock(); 5694 if (!task) 5695 return -ENOENT; 5696 5697 err = 0; 5698 file = fget_task(task, fd); 5699 put_task_struct(task); 5700 if (!file) 5701 return -EBADF; 5702 5703 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5704 struct bpf_link *link = file->private_data; 5705 5706 if (link->ops == &bpf_raw_tp_link_lops) { 5707 struct bpf_raw_tp_link *raw_tp = 5708 container_of(link, struct bpf_raw_tp_link, link); 5709 struct bpf_raw_event_map *btp = raw_tp->btp; 5710 5711 err = bpf_task_fd_query_copy(attr, uattr, 5712 raw_tp->link.prog->aux->id, 5713 BPF_FD_TYPE_RAW_TRACEPOINT, 5714 btp->tp->name, 0, 0); 5715 goto put_file; 5716 } 5717 goto out_not_supp; 5718 } 5719 5720 event = perf_get_event(file); 5721 if (!IS_ERR(event)) { 5722 u64 probe_offset, probe_addr; 5723 u32 prog_id, fd_type; 5724 const char *buf; 5725 5726 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5727 &buf, &probe_offset, 5728 &probe_addr, NULL); 5729 if (!err) 5730 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5731 fd_type, buf, 5732 probe_offset, 5733 probe_addr); 5734 goto put_file; 5735 } 5736 5737 out_not_supp: 5738 err = -ENOTSUPP; 5739 put_file: 5740 fput(file); 5741 return err; 5742 } 5743 5744 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5745 5746 #define BPF_DO_BATCH(fn, ...) \ 5747 do { \ 5748 if (!fn) { \ 5749 err = -ENOTSUPP; \ 5750 goto err_put; \ 5751 } \ 5752 err = fn(__VA_ARGS__); \ 5753 } while (0) 5754 5755 static int bpf_map_do_batch(const union bpf_attr *attr, 5756 union bpf_attr __user *uattr, 5757 int cmd) 5758 { 5759 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5760 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5761 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5762 struct bpf_map *map; 5763 int err; 5764 5765 if (CHECK_ATTR(BPF_MAP_BATCH)) 5766 return -EINVAL; 5767 5768 CLASS(fd, f)(attr->batch.map_fd); 5769 5770 map = __bpf_map_get(f); 5771 if (IS_ERR(map)) 5772 return PTR_ERR(map); 5773 if (has_write) 5774 bpf_map_write_active_inc(map); 5775 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5776 err = -EPERM; 5777 goto err_put; 5778 } 5779 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5780 err = -EPERM; 5781 goto err_put; 5782 } 5783 5784 if (cmd == BPF_MAP_LOOKUP_BATCH) 5785 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5786 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5787 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5788 else if (cmd == BPF_MAP_UPDATE_BATCH) 5789 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5790 else 5791 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5792 err_put: 5793 if (has_write) { 5794 maybe_wait_bpf_programs(map); 5795 bpf_map_write_active_dec(map); 5796 } 5797 return err; 5798 } 5799 5800 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 5801 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5802 { 5803 struct bpf_prog *prog; 5804 int ret; 5805 5806 if (CHECK_ATTR(BPF_LINK_CREATE)) 5807 return -EINVAL; 5808 5809 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5810 return bpf_struct_ops_link_create(attr); 5811 5812 prog = bpf_prog_get(attr->link_create.prog_fd); 5813 if (IS_ERR(prog)) 5814 return PTR_ERR(prog); 5815 5816 ret = bpf_prog_attach_check_attach_type(prog, 5817 attr->link_create.attach_type); 5818 if (ret) 5819 goto out; 5820 5821 switch (prog->type) { 5822 case BPF_PROG_TYPE_CGROUP_SKB: 5823 case BPF_PROG_TYPE_CGROUP_SOCK: 5824 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5825 case BPF_PROG_TYPE_SOCK_OPS: 5826 case BPF_PROG_TYPE_CGROUP_DEVICE: 5827 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5828 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5829 ret = cgroup_bpf_link_attach(attr, prog); 5830 break; 5831 case BPF_PROG_TYPE_EXT: 5832 ret = bpf_tracing_prog_attach(prog, 5833 attr->link_create.target_fd, 5834 attr->link_create.target_btf_id, 5835 attr->link_create.tracing.cookie, 5836 attr->link_create.attach_type); 5837 break; 5838 case BPF_PROG_TYPE_LSM: 5839 case BPF_PROG_TYPE_TRACING: 5840 if (attr->link_create.attach_type != prog->expected_attach_type) { 5841 ret = -EINVAL; 5842 goto out; 5843 } 5844 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5845 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, 5846 attr->link_create.attach_type); 5847 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5848 ret = bpf_iter_link_attach(attr, uattr, prog); 5849 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5850 ret = cgroup_bpf_link_attach(attr, prog); 5851 else 5852 ret = bpf_tracing_prog_attach(prog, 5853 attr->link_create.target_fd, 5854 attr->link_create.target_btf_id, 5855 attr->link_create.tracing.cookie, 5856 attr->link_create.attach_type); 5857 break; 5858 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5859 case BPF_PROG_TYPE_SK_LOOKUP: 5860 ret = netns_bpf_link_create(attr, prog); 5861 break; 5862 case BPF_PROG_TYPE_SK_MSG: 5863 case BPF_PROG_TYPE_SK_SKB: 5864 ret = sock_map_link_create(attr, prog); 5865 break; 5866 #ifdef CONFIG_NET 5867 case BPF_PROG_TYPE_XDP: 5868 ret = bpf_xdp_link_attach(attr, prog); 5869 break; 5870 case BPF_PROG_TYPE_SCHED_CLS: 5871 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5872 attr->link_create.attach_type == BPF_TCX_EGRESS) 5873 ret = tcx_link_attach(attr, prog); 5874 else 5875 ret = netkit_link_attach(attr, prog); 5876 break; 5877 case BPF_PROG_TYPE_NETFILTER: 5878 ret = bpf_nf_link_attach(attr, prog); 5879 break; 5880 #endif 5881 case BPF_PROG_TYPE_PERF_EVENT: 5882 case BPF_PROG_TYPE_TRACEPOINT: 5883 ret = bpf_perf_link_attach(attr, prog); 5884 break; 5885 case BPF_PROG_TYPE_KPROBE: 5886 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5887 ret = bpf_perf_link_attach(attr, prog); 5888 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5889 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5890 ret = bpf_kprobe_multi_link_attach(attr, prog); 5891 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5892 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5893 ret = bpf_uprobe_multi_link_attach(attr, prog); 5894 break; 5895 default: 5896 ret = -EINVAL; 5897 } 5898 5899 out: 5900 if (ret < 0) 5901 bpf_prog_put(prog); 5902 return ret; 5903 } 5904 5905 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5906 { 5907 struct bpf_map *new_map, *old_map = NULL; 5908 int ret; 5909 5910 new_map = bpf_map_get(attr->link_update.new_map_fd); 5911 if (IS_ERR(new_map)) 5912 return PTR_ERR(new_map); 5913 5914 if (attr->link_update.flags & BPF_F_REPLACE) { 5915 old_map = bpf_map_get(attr->link_update.old_map_fd); 5916 if (IS_ERR(old_map)) { 5917 ret = PTR_ERR(old_map); 5918 goto out_put; 5919 } 5920 } else if (attr->link_update.old_map_fd) { 5921 ret = -EINVAL; 5922 goto out_put; 5923 } 5924 5925 ret = link->ops->update_map(link, new_map, old_map); 5926 5927 if (old_map) 5928 bpf_map_put(old_map); 5929 out_put: 5930 bpf_map_put(new_map); 5931 return ret; 5932 } 5933 5934 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5935 5936 static int link_update(union bpf_attr *attr) 5937 { 5938 struct bpf_prog *old_prog = NULL, *new_prog; 5939 struct bpf_link *link; 5940 u32 flags; 5941 int ret; 5942 5943 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5944 return -EINVAL; 5945 5946 flags = attr->link_update.flags; 5947 if (flags & ~BPF_F_REPLACE) 5948 return -EINVAL; 5949 5950 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5951 if (IS_ERR(link)) 5952 return PTR_ERR(link); 5953 5954 if (link->ops->update_map) { 5955 ret = link_update_map(link, attr); 5956 goto out_put_link; 5957 } 5958 5959 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5960 if (IS_ERR(new_prog)) { 5961 ret = PTR_ERR(new_prog); 5962 goto out_put_link; 5963 } 5964 5965 if (flags & BPF_F_REPLACE) { 5966 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5967 if (IS_ERR(old_prog)) { 5968 ret = PTR_ERR(old_prog); 5969 old_prog = NULL; 5970 goto out_put_progs; 5971 } 5972 } else if (attr->link_update.old_prog_fd) { 5973 ret = -EINVAL; 5974 goto out_put_progs; 5975 } 5976 5977 if (link->ops->update_prog) 5978 ret = link->ops->update_prog(link, new_prog, old_prog); 5979 else 5980 ret = -EINVAL; 5981 5982 out_put_progs: 5983 if (old_prog) 5984 bpf_prog_put(old_prog); 5985 if (ret) 5986 bpf_prog_put(new_prog); 5987 out_put_link: 5988 bpf_link_put_direct(link); 5989 return ret; 5990 } 5991 5992 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5993 5994 static int link_detach(union bpf_attr *attr) 5995 { 5996 struct bpf_link *link; 5997 int ret; 5998 5999 if (CHECK_ATTR(BPF_LINK_DETACH)) 6000 return -EINVAL; 6001 6002 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 6003 if (IS_ERR(link)) 6004 return PTR_ERR(link); 6005 6006 if (link->ops->detach) 6007 ret = link->ops->detach(link); 6008 else 6009 ret = -EOPNOTSUPP; 6010 6011 bpf_link_put_direct(link); 6012 return ret; 6013 } 6014 6015 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 6016 { 6017 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 6018 } 6019 EXPORT_SYMBOL(bpf_link_inc_not_zero); 6020 6021 struct bpf_link *bpf_link_by_id(u32 id) 6022 { 6023 struct bpf_link *link; 6024 6025 if (!id) 6026 return ERR_PTR(-ENOENT); 6027 6028 spin_lock_bh(&link_idr_lock); 6029 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 6030 link = idr_find(&link_idr, id); 6031 if (link) { 6032 if (link->id) 6033 link = bpf_link_inc_not_zero(link); 6034 else 6035 link = ERR_PTR(-EAGAIN); 6036 } else { 6037 link = ERR_PTR(-ENOENT); 6038 } 6039 spin_unlock_bh(&link_idr_lock); 6040 return link; 6041 } 6042 6043 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 6044 { 6045 struct bpf_link *link; 6046 6047 spin_lock_bh(&link_idr_lock); 6048 again: 6049 link = idr_get_next(&link_idr, id); 6050 if (link) { 6051 link = bpf_link_inc_not_zero(link); 6052 if (IS_ERR(link)) { 6053 (*id)++; 6054 goto again; 6055 } 6056 } 6057 spin_unlock_bh(&link_idr_lock); 6058 6059 return link; 6060 } 6061 6062 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 6063 6064 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 6065 { 6066 struct bpf_link *link; 6067 u32 id = attr->link_id; 6068 int fd; 6069 6070 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 6071 return -EINVAL; 6072 6073 if (!capable(CAP_SYS_ADMIN)) 6074 return -EPERM; 6075 6076 link = bpf_link_by_id(id); 6077 if (IS_ERR(link)) 6078 return PTR_ERR(link); 6079 6080 fd = bpf_link_new_fd(link); 6081 if (fd < 0) 6082 bpf_link_put_direct(link); 6083 6084 return fd; 6085 } 6086 6087 DEFINE_MUTEX(bpf_stats_enabled_mutex); 6088 6089 static int bpf_stats_release(struct inode *inode, struct file *file) 6090 { 6091 mutex_lock(&bpf_stats_enabled_mutex); 6092 static_key_slow_dec(&bpf_stats_enabled_key.key); 6093 mutex_unlock(&bpf_stats_enabled_mutex); 6094 return 0; 6095 } 6096 6097 static const struct file_operations bpf_stats_fops = { 6098 .release = bpf_stats_release, 6099 }; 6100 6101 static int bpf_enable_runtime_stats(void) 6102 { 6103 int fd; 6104 6105 mutex_lock(&bpf_stats_enabled_mutex); 6106 6107 /* Set a very high limit to avoid overflow */ 6108 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 6109 mutex_unlock(&bpf_stats_enabled_mutex); 6110 return -EBUSY; 6111 } 6112 6113 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 6114 if (fd >= 0) 6115 static_key_slow_inc(&bpf_stats_enabled_key.key); 6116 6117 mutex_unlock(&bpf_stats_enabled_mutex); 6118 return fd; 6119 } 6120 6121 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 6122 6123 static int bpf_enable_stats(union bpf_attr *attr) 6124 { 6125 6126 if (CHECK_ATTR(BPF_ENABLE_STATS)) 6127 return -EINVAL; 6128 6129 if (!capable(CAP_SYS_ADMIN)) 6130 return -EPERM; 6131 6132 switch (attr->enable_stats.type) { 6133 case BPF_STATS_RUN_TIME: 6134 return bpf_enable_runtime_stats(); 6135 default: 6136 break; 6137 } 6138 return -EINVAL; 6139 } 6140 6141 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 6142 6143 static int bpf_iter_create(union bpf_attr *attr) 6144 { 6145 struct bpf_link *link; 6146 int err; 6147 6148 if (CHECK_ATTR(BPF_ITER_CREATE)) 6149 return -EINVAL; 6150 6151 if (attr->iter_create.flags) 6152 return -EINVAL; 6153 6154 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 6155 if (IS_ERR(link)) 6156 return PTR_ERR(link); 6157 6158 err = bpf_iter_new_fd(link); 6159 bpf_link_put_direct(link); 6160 6161 return err; 6162 } 6163 6164 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 6165 6166 static int bpf_prog_bind_map(union bpf_attr *attr) 6167 { 6168 struct bpf_prog *prog; 6169 struct bpf_map *map; 6170 struct bpf_map **used_maps_old, **used_maps_new; 6171 int i, ret = 0; 6172 6173 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 6174 return -EINVAL; 6175 6176 if (attr->prog_bind_map.flags) 6177 return -EINVAL; 6178 6179 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 6180 if (IS_ERR(prog)) 6181 return PTR_ERR(prog); 6182 6183 map = bpf_map_get(attr->prog_bind_map.map_fd); 6184 if (IS_ERR(map)) { 6185 ret = PTR_ERR(map); 6186 goto out_prog_put; 6187 } 6188 6189 mutex_lock(&prog->aux->used_maps_mutex); 6190 6191 used_maps_old = prog->aux->used_maps; 6192 6193 for (i = 0; i < prog->aux->used_map_cnt; i++) 6194 if (used_maps_old[i] == map) { 6195 bpf_map_put(map); 6196 goto out_unlock; 6197 } 6198 6199 used_maps_new = kmalloc_objs(used_maps_new[0], 6200 prog->aux->used_map_cnt + 1); 6201 if (!used_maps_new) { 6202 ret = -ENOMEM; 6203 goto out_unlock; 6204 } 6205 6206 /* The bpf program will not access the bpf map, but for the sake of 6207 * simplicity, increase sleepable_refcnt for sleepable program as well. 6208 */ 6209 if (prog->sleepable) 6210 atomic64_inc(&map->sleepable_refcnt); 6211 memcpy(used_maps_new, used_maps_old, 6212 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 6213 used_maps_new[prog->aux->used_map_cnt] = map; 6214 6215 prog->aux->used_map_cnt++; 6216 prog->aux->used_maps = used_maps_new; 6217 6218 kfree(used_maps_old); 6219 6220 out_unlock: 6221 mutex_unlock(&prog->aux->used_maps_mutex); 6222 6223 if (ret) 6224 bpf_map_put(map); 6225 out_prog_put: 6226 bpf_prog_put(prog); 6227 return ret; 6228 } 6229 6230 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 6231 6232 static int token_create(union bpf_attr *attr) 6233 { 6234 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 6235 return -EINVAL; 6236 6237 /* no flags are supported yet */ 6238 if (attr->token_create.flags) 6239 return -EINVAL; 6240 6241 return bpf_token_create(attr); 6242 } 6243 6244 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd 6245 6246 static int prog_stream_read(union bpf_attr *attr) 6247 { 6248 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); 6249 u32 len = attr->prog_stream_read.stream_buf_len; 6250 struct bpf_prog *prog; 6251 int ret; 6252 6253 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) 6254 return -EINVAL; 6255 6256 prog = bpf_prog_get(attr->prog_stream_read.prog_fd); 6257 if (IS_ERR(prog)) 6258 return PTR_ERR(prog); 6259 6260 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); 6261 bpf_prog_put(prog); 6262 6263 return ret; 6264 } 6265 6266 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.prog_fd 6267 6268 static int prog_assoc_struct_ops(union bpf_attr *attr) 6269 { 6270 struct bpf_prog *prog; 6271 struct bpf_map *map; 6272 int ret; 6273 6274 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS)) 6275 return -EINVAL; 6276 6277 if (attr->prog_assoc_struct_ops.flags) 6278 return -EINVAL; 6279 6280 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd); 6281 if (IS_ERR(prog)) 6282 return PTR_ERR(prog); 6283 6284 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) { 6285 ret = -EINVAL; 6286 goto put_prog; 6287 } 6288 6289 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd); 6290 if (IS_ERR(map)) { 6291 ret = PTR_ERR(map); 6292 goto put_prog; 6293 } 6294 6295 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) { 6296 ret = -EINVAL; 6297 goto put_map; 6298 } 6299 6300 ret = bpf_prog_assoc_struct_ops(prog, map); 6301 6302 put_map: 6303 bpf_map_put(map); 6304 put_prog: 6305 bpf_prog_put(prog); 6306 return ret; 6307 } 6308 6309 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, 6310 bpfptr_t uattr_common, unsigned int size_common) 6311 { 6312 struct bpf_common_attr attr_common; 6313 u32 offsetof_log_true_size = 0; 6314 struct bpf_log_attr attr_log; 6315 union bpf_attr attr; 6316 int err; 6317 6318 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 6319 if (err) 6320 return err; 6321 size = min_t(u32, size, sizeof(attr)); 6322 6323 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 6324 memset(&attr, 0, sizeof(attr)); 6325 if (copy_from_bpfptr(&attr, uattr, size) != 0) 6326 return -EFAULT; 6327 6328 memset(&attr_common, 0, sizeof(attr_common)); 6329 if (cmd & BPF_COMMON_ATTRS) { 6330 err = bpf_check_uarg_tail_zero(uattr_common, 6331 offsetofend(struct bpf_common_attr, log_true_size), 6332 size_common); 6333 if (err) 6334 return err; 6335 6336 cmd &= ~BPF_COMMON_ATTRS; 6337 size_common = min_t(u32, size_common, sizeof(attr_common)); 6338 if (copy_from_bpfptr(&attr_common, uattr_common, size_common) != 0) 6339 return -EFAULT; 6340 } else { 6341 size_common = 0; 6342 } 6343 6344 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 6345 if (err < 0) 6346 return err; 6347 6348 switch (cmd) { 6349 case BPF_MAP_CREATE: 6350 err = map_create(&attr, uattr, &attr_common, uattr_common, size_common); 6351 break; 6352 case BPF_MAP_LOOKUP_ELEM: 6353 err = map_lookup_elem(&attr); 6354 break; 6355 case BPF_MAP_UPDATE_ELEM: 6356 err = map_update_elem(&attr, uattr); 6357 break; 6358 case BPF_MAP_DELETE_ELEM: 6359 err = map_delete_elem(&attr, uattr); 6360 break; 6361 case BPF_MAP_GET_NEXT_KEY: 6362 err = map_get_next_key(&attr); 6363 break; 6364 case BPF_MAP_FREEZE: 6365 err = map_freeze(&attr); 6366 break; 6367 case BPF_PROG_LOAD: 6368 if (size >= offsetofend(union bpf_attr, log_true_size)) 6369 offsetof_log_true_size = offsetof(union bpf_attr, log_true_size); 6370 err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level, 6371 offsetof_log_true_size, uattr, &attr_common, uattr_common, 6372 size_common); 6373 err = err ?: bpf_prog_load(&attr, uattr, &attr_log); 6374 break; 6375 case BPF_OBJ_PIN: 6376 err = bpf_obj_pin(&attr); 6377 break; 6378 case BPF_OBJ_GET: 6379 err = bpf_obj_get(&attr); 6380 break; 6381 case BPF_PROG_ATTACH: 6382 err = bpf_prog_attach(&attr); 6383 break; 6384 case BPF_PROG_DETACH: 6385 err = bpf_prog_detach(&attr); 6386 break; 6387 case BPF_PROG_QUERY: 6388 err = bpf_prog_query(&attr, uattr.user, size); 6389 break; 6390 case BPF_PROG_TEST_RUN: 6391 err = bpf_prog_test_run(&attr, uattr.user); 6392 break; 6393 case BPF_PROG_GET_NEXT_ID: 6394 err = bpf_obj_get_next_id(&attr, uattr.user, 6395 &prog_idr, &prog_idr_lock); 6396 break; 6397 case BPF_MAP_GET_NEXT_ID: 6398 err = bpf_obj_get_next_id(&attr, uattr.user, 6399 &map_idr, &map_idr_lock); 6400 break; 6401 case BPF_BTF_GET_NEXT_ID: 6402 err = bpf_obj_get_next_id(&attr, uattr.user, 6403 &btf_idr, &btf_idr_lock); 6404 break; 6405 case BPF_PROG_GET_FD_BY_ID: 6406 err = bpf_prog_get_fd_by_id(&attr); 6407 break; 6408 case BPF_MAP_GET_FD_BY_ID: 6409 err = bpf_map_get_fd_by_id(&attr); 6410 break; 6411 case BPF_OBJ_GET_INFO_BY_FD: 6412 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 6413 break; 6414 case BPF_RAW_TRACEPOINT_OPEN: 6415 err = bpf_raw_tracepoint_open(&attr); 6416 break; 6417 case BPF_BTF_LOAD: 6418 if (size >= offsetofend(union bpf_attr, btf_log_true_size)) 6419 offsetof_log_true_size = offsetof(union bpf_attr, btf_log_true_size); 6420 err = bpf_log_attr_init(&attr_log, attr.btf_log_buf, attr.btf_log_size, 6421 attr.btf_log_level, offsetof_log_true_size, uattr, 6422 &attr_common, uattr_common, size_common); 6423 err = err ?: bpf_btf_load(&attr, uattr, &attr_log); 6424 break; 6425 case BPF_BTF_GET_FD_BY_ID: 6426 err = bpf_btf_get_fd_by_id(&attr); 6427 break; 6428 case BPF_TASK_FD_QUERY: 6429 err = bpf_task_fd_query(&attr, uattr.user); 6430 break; 6431 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 6432 err = map_lookup_and_delete_elem(&attr); 6433 break; 6434 case BPF_MAP_LOOKUP_BATCH: 6435 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 6436 break; 6437 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 6438 err = bpf_map_do_batch(&attr, uattr.user, 6439 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 6440 break; 6441 case BPF_MAP_UPDATE_BATCH: 6442 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 6443 break; 6444 case BPF_MAP_DELETE_BATCH: 6445 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 6446 break; 6447 case BPF_LINK_CREATE: 6448 err = link_create(&attr, uattr); 6449 break; 6450 case BPF_LINK_UPDATE: 6451 err = link_update(&attr); 6452 break; 6453 case BPF_LINK_GET_FD_BY_ID: 6454 err = bpf_link_get_fd_by_id(&attr); 6455 break; 6456 case BPF_LINK_GET_NEXT_ID: 6457 err = bpf_obj_get_next_id(&attr, uattr.user, 6458 &link_idr, &link_idr_lock); 6459 break; 6460 case BPF_ENABLE_STATS: 6461 err = bpf_enable_stats(&attr); 6462 break; 6463 case BPF_ITER_CREATE: 6464 err = bpf_iter_create(&attr); 6465 break; 6466 case BPF_LINK_DETACH: 6467 err = link_detach(&attr); 6468 break; 6469 case BPF_PROG_BIND_MAP: 6470 err = bpf_prog_bind_map(&attr); 6471 break; 6472 case BPF_TOKEN_CREATE: 6473 err = token_create(&attr); 6474 break; 6475 case BPF_PROG_STREAM_READ_BY_FD: 6476 err = prog_stream_read(&attr); 6477 break; 6478 case BPF_PROG_ASSOC_STRUCT_OPS: 6479 err = prog_assoc_struct_ops(&attr); 6480 break; 6481 default: 6482 err = -EINVAL; 6483 break; 6484 } 6485 6486 return err; 6487 } 6488 6489 SYSCALL_DEFINE5(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size, 6490 struct bpf_common_attr __user *, uattr_common, unsigned int, size_common) 6491 { 6492 return __sys_bpf(cmd, USER_BPFPTR(uattr), size, USER_BPFPTR(uattr_common), size_common); 6493 } 6494 6495 static bool syscall_prog_is_valid_access(int off, int size, 6496 enum bpf_access_type type, 6497 const struct bpf_prog *prog, 6498 struct bpf_insn_access_aux *info) 6499 { 6500 if (off < 0 || off >= U16_MAX) 6501 return false; 6502 /* No alignment requirements for syscall ctx accesses. */ 6503 return true; 6504 } 6505 6506 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 6507 { 6508 switch (cmd) { 6509 case BPF_MAP_CREATE: 6510 case BPF_MAP_DELETE_ELEM: 6511 case BPF_MAP_UPDATE_ELEM: 6512 case BPF_MAP_FREEZE: 6513 case BPF_MAP_GET_FD_BY_ID: 6514 case BPF_PROG_LOAD: 6515 case BPF_BTF_LOAD: 6516 case BPF_LINK_CREATE: 6517 case BPF_RAW_TRACEPOINT_OPEN: 6518 break; 6519 default: 6520 return -EINVAL; 6521 } 6522 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size, KERNEL_BPFPTR(NULL), 0); 6523 } 6524 6525 6526 /* To shut up -Wmissing-prototypes. 6527 * This function is used by the kernel light skeleton 6528 * to load bpf programs when modules are loaded or during kernel boot. 6529 * See tools/lib/bpf/skel_internal.h 6530 */ 6531 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 6532 6533 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 6534 { 6535 struct bpf_prog * __maybe_unused prog; 6536 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 6537 6538 switch (cmd) { 6539 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 6540 case BPF_PROG_TEST_RUN: 6541 if (attr->test.data_in || attr->test.data_out || 6542 attr->test.ctx_out || attr->test.duration || 6543 attr->test.repeat || attr->test.flags) 6544 return -EINVAL; 6545 6546 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 6547 if (IS_ERR(prog)) 6548 return PTR_ERR(prog); 6549 6550 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 6551 attr->test.ctx_size_in > U16_MAX) { 6552 bpf_prog_put(prog); 6553 return -EINVAL; 6554 } 6555 6556 run_ctx.bpf_cookie = 0; 6557 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 6558 /* recursion detected */ 6559 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 6560 bpf_prog_put(prog); 6561 return -EBUSY; 6562 } 6563 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 6564 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 6565 &run_ctx); 6566 bpf_prog_put(prog); 6567 return 0; 6568 #endif 6569 default: 6570 return ____bpf_sys_bpf(cmd, attr, size); 6571 } 6572 } 6573 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); 6574 6575 static const struct bpf_func_proto bpf_sys_bpf_proto = { 6576 .func = bpf_sys_bpf, 6577 .gpl_only = false, 6578 .ret_type = RET_INTEGER, 6579 .arg1_type = ARG_ANYTHING, 6580 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6581 .arg3_type = ARG_CONST_SIZE, 6582 }; 6583 6584 const struct bpf_func_proto * __weak 6585 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6586 { 6587 return bpf_base_func_proto(func_id, prog); 6588 } 6589 6590 BPF_CALL_1(bpf_sys_close, u32, fd) 6591 { 6592 /* When bpf program calls this helper there should not be 6593 * an fdget() without matching completed fdput(). 6594 * This helper is allowed in the following callchain only: 6595 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6596 */ 6597 return close_fd(fd); 6598 } 6599 6600 static const struct bpf_func_proto bpf_sys_close_proto = { 6601 .func = bpf_sys_close, 6602 .gpl_only = false, 6603 .ret_type = RET_INTEGER, 6604 .arg1_type = ARG_ANYTHING, 6605 }; 6606 6607 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6608 { 6609 *res = 0; 6610 if (flags) 6611 return -EINVAL; 6612 6613 if (name_sz <= 1 || name[name_sz - 1]) 6614 return -EINVAL; 6615 6616 if (!bpf_dump_raw_ok(current_cred())) 6617 return -EPERM; 6618 6619 *res = kallsyms_lookup_name(name); 6620 return *res ? 0 : -ENOENT; 6621 } 6622 6623 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6624 .func = bpf_kallsyms_lookup_name, 6625 .gpl_only = false, 6626 .ret_type = RET_INTEGER, 6627 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6628 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 6629 .arg3_type = ARG_ANYTHING, 6630 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6631 .arg4_size = sizeof(u64), 6632 }; 6633 6634 static const struct bpf_func_proto * 6635 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6636 { 6637 switch (func_id) { 6638 case BPF_FUNC_sys_bpf: 6639 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6640 ? NULL : &bpf_sys_bpf_proto; 6641 case BPF_FUNC_btf_find_by_name_kind: 6642 return &bpf_btf_find_by_name_kind_proto; 6643 case BPF_FUNC_sys_close: 6644 return &bpf_sys_close_proto; 6645 case BPF_FUNC_kallsyms_lookup_name: 6646 return &bpf_kallsyms_lookup_name_proto; 6647 default: 6648 return tracing_prog_func_proto(func_id, prog); 6649 } 6650 } 6651 6652 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6653 .get_func_proto = syscall_prog_func_proto, 6654 .is_valid_access = syscall_prog_is_valid_access, 6655 }; 6656 6657 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6658 .test_run = bpf_prog_test_run_syscall, 6659 }; 6660 6661 #ifdef CONFIG_SYSCTL 6662 static int bpf_stats_handler(const struct ctl_table *table, int write, 6663 void *buffer, size_t *lenp, loff_t *ppos) 6664 { 6665 struct static_key *key = (struct static_key *)table->data; 6666 static int saved_val; 6667 int val, ret; 6668 struct ctl_table tmp = { 6669 .data = &val, 6670 .maxlen = sizeof(val), 6671 .mode = table->mode, 6672 .extra1 = SYSCTL_ZERO, 6673 .extra2 = SYSCTL_ONE, 6674 }; 6675 6676 if (write && !capable(CAP_SYS_ADMIN)) 6677 return -EPERM; 6678 6679 mutex_lock(&bpf_stats_enabled_mutex); 6680 val = saved_val; 6681 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6682 if (write && !ret && val != saved_val) { 6683 if (val) 6684 static_key_slow_inc(key); 6685 else 6686 static_key_slow_dec(key); 6687 saved_val = val; 6688 } 6689 mutex_unlock(&bpf_stats_enabled_mutex); 6690 return ret; 6691 } 6692 6693 void __weak unpriv_ebpf_notify(int new_state) 6694 { 6695 } 6696 6697 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6698 void *buffer, size_t *lenp, loff_t *ppos) 6699 { 6700 int ret, unpriv_enable = *(int *)table->data; 6701 bool locked_state = unpriv_enable == 1; 6702 struct ctl_table tmp = *table; 6703 6704 if (write && !capable(CAP_SYS_ADMIN)) 6705 return -EPERM; 6706 6707 tmp.data = &unpriv_enable; 6708 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6709 if (write && !ret) { 6710 if (locked_state && unpriv_enable != 1) 6711 return -EPERM; 6712 *(int *)table->data = unpriv_enable; 6713 } 6714 6715 if (write) 6716 unpriv_ebpf_notify(unpriv_enable); 6717 6718 return ret; 6719 } 6720 6721 static const struct ctl_table bpf_syscall_table[] = { 6722 { 6723 .procname = "unprivileged_bpf_disabled", 6724 .data = &sysctl_unprivileged_bpf_disabled, 6725 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6726 .mode = 0644, 6727 .proc_handler = bpf_unpriv_handler, 6728 .extra1 = SYSCTL_ZERO, 6729 .extra2 = SYSCTL_TWO, 6730 }, 6731 { 6732 .procname = "bpf_stats_enabled", 6733 .data = &bpf_stats_enabled_key.key, 6734 .mode = 0644, 6735 .proc_handler = bpf_stats_handler, 6736 }, 6737 }; 6738 6739 static int __init bpf_syscall_sysctl_init(void) 6740 { 6741 register_sysctl_init("kernel", bpf_syscall_table); 6742 return 0; 6743 } 6744 late_initcall(bpf_syscall_sysctl_init); 6745 #endif /* CONFIG_SYSCTL */ 6746