1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 */ 4 #include <linux/bpf.h> 5 #include <linux/bpf-cgroup.h> 6 #include <linux/bpf_trace.h> 7 #include <linux/bpf_lirc.h> 8 #include <linux/bpf_verifier.h> 9 #include <linux/bsearch.h> 10 #include <linux/btf.h> 11 #include <linux/syscalls.h> 12 #include <linux/slab.h> 13 #include <linux/sched/signal.h> 14 #include <linux/vmalloc.h> 15 #include <linux/mmzone.h> 16 #include <linux/anon_inodes.h> 17 #include <linux/fdtable.h> 18 #include <linux/file.h> 19 #include <linux/fs.h> 20 #include <linux/license.h> 21 #include <linux/filter.h> 22 #include <linux/kernel.h> 23 #include <linux/idr.h> 24 #include <linux/cred.h> 25 #include <linux/timekeeping.h> 26 #include <linux/ctype.h> 27 #include <linux/nospec.h> 28 #include <linux/audit.h> 29 #include <uapi/linux/btf.h> 30 #include <linux/pgtable.h> 31 #include <linux/bpf_lsm.h> 32 #include <linux/poll.h> 33 #include <linux/sort.h> 34 #include <linux/bpf-netns.h> 35 #include <linux/rcupdate_trace.h> 36 #include <linux/memcontrol.h> 37 #include <linux/trace_events.h> 38 #include <linux/tracepoint.h> 39 40 #include <net/netfilter/nf_bpf_link.h> 41 #include <net/netkit.h> 42 #include <net/tcx.h> 43 44 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ 45 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ 46 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 47 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) 48 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) 49 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ 50 IS_FD_HASH(map)) 51 52 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) 53 54 DEFINE_PER_CPU(int, bpf_prog_active); 55 static DEFINE_IDR(prog_idr); 56 static DEFINE_SPINLOCK(prog_idr_lock); 57 static DEFINE_IDR(map_idr); 58 static DEFINE_SPINLOCK(map_idr_lock); 59 static DEFINE_IDR(link_idr); 60 static DEFINE_SPINLOCK(link_idr_lock); 61 62 int sysctl_unprivileged_bpf_disabled __read_mostly = 63 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; 64 65 static const struct bpf_map_ops * const bpf_map_types[] = { 66 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 67 #define BPF_MAP_TYPE(_id, _ops) \ 68 [_id] = &_ops, 69 #define BPF_LINK_TYPE(_id, _name) 70 #include <linux/bpf_types.h> 71 #undef BPF_PROG_TYPE 72 #undef BPF_MAP_TYPE 73 #undef BPF_LINK_TYPE 74 }; 75 76 /* 77 * If we're handed a bigger struct than we know of, ensure all the unknown bits 78 * are 0 - i.e. new user-space does not rely on any kernel feature extensions 79 * we don't know about yet. 80 * 81 * There is a ToCToU between this function call and the following 82 * copy_from_user() call. However, this is not a concern since this function is 83 * meant to be a future-proofing of bits. 84 */ 85 int bpf_check_uarg_tail_zero(bpfptr_t uaddr, 86 size_t expected_size, 87 size_t actual_size) 88 { 89 int res; 90 91 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ 92 return -E2BIG; 93 94 if (actual_size <= expected_size) 95 return 0; 96 97 if (uaddr.is_kernel) 98 res = memchr_inv(uaddr.kernel + expected_size, 0, 99 actual_size - expected_size) == NULL; 100 else 101 res = check_zeroed_user(uaddr.user + expected_size, 102 actual_size - expected_size); 103 if (res < 0) 104 return res; 105 return res ? 0 : -E2BIG; 106 } 107 108 const struct bpf_map_ops bpf_map_offload_ops = { 109 .map_meta_equal = bpf_map_meta_equal, 110 .map_alloc = bpf_map_offload_map_alloc, 111 .map_free = bpf_map_offload_map_free, 112 .map_check_btf = map_check_no_btf, 113 .map_mem_usage = bpf_map_offload_map_mem_usage, 114 }; 115 116 static void bpf_map_write_active_inc(struct bpf_map *map) 117 { 118 atomic64_inc(&map->writecnt); 119 } 120 121 static void bpf_map_write_active_dec(struct bpf_map *map) 122 { 123 atomic64_dec(&map->writecnt); 124 } 125 126 bool bpf_map_write_active(const struct bpf_map *map) 127 { 128 return atomic64_read(&map->writecnt) != 0; 129 } 130 131 static u32 bpf_map_value_size(const struct bpf_map *map) 132 { 133 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 134 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 135 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || 136 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) 137 return round_up(map->value_size, 8) * num_possible_cpus(); 138 else if (IS_FD_MAP(map)) 139 return sizeof(u32); 140 else 141 return map->value_size; 142 } 143 144 static void maybe_wait_bpf_programs(struct bpf_map *map) 145 { 146 /* Wait for any running non-sleepable BPF programs to complete so that 147 * userspace, when we return to it, knows that all non-sleepable 148 * programs that could be running use the new map value. For sleepable 149 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait 150 * for the completions of these programs, but considering the waiting 151 * time can be very long and userspace may think it will hang forever, 152 * so don't handle sleepable BPF programs now. 153 */ 154 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || 155 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 156 synchronize_rcu(); 157 } 158 159 static void unpin_uptr_kaddr(void *kaddr) 160 { 161 if (kaddr) 162 unpin_user_page(virt_to_page(kaddr)); 163 } 164 165 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj) 166 { 167 const struct btf_field *field; 168 void **uptr_addr; 169 int i; 170 171 for (i = 0, field = rec->fields; i < cnt; i++, field++) { 172 if (field->type != BPF_UPTR) 173 continue; 174 175 uptr_addr = obj + field->offset; 176 unpin_uptr_kaddr(*uptr_addr); 177 } 178 } 179 180 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj) 181 { 182 if (!btf_record_has_field(rec, BPF_UPTR)) 183 return; 184 185 __bpf_obj_unpin_uptrs(rec, rec->cnt, obj); 186 } 187 188 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj) 189 { 190 const struct btf_field *field; 191 const struct btf_type *t; 192 unsigned long start, end; 193 struct page *page; 194 void **uptr_addr; 195 int i, err; 196 197 if (!btf_record_has_field(rec, BPF_UPTR)) 198 return 0; 199 200 for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) { 201 if (field->type != BPF_UPTR) 202 continue; 203 204 uptr_addr = obj + field->offset; 205 start = *(unsigned long *)uptr_addr; 206 if (!start) 207 continue; 208 209 t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id); 210 /* t->size was checked for zero before */ 211 if (check_add_overflow(start, t->size - 1, &end)) { 212 err = -EFAULT; 213 goto unpin_all; 214 } 215 216 /* The uptr's struct cannot span across two pages */ 217 if ((start & PAGE_MASK) != (end & PAGE_MASK)) { 218 err = -EOPNOTSUPP; 219 goto unpin_all; 220 } 221 222 err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page); 223 if (err != 1) 224 goto unpin_all; 225 226 if (PageHighMem(page)) { 227 err = -EOPNOTSUPP; 228 unpin_user_page(page); 229 goto unpin_all; 230 } 231 232 *uptr_addr = page_address(page) + offset_in_page(start); 233 } 234 235 return 0; 236 237 unpin_all: 238 __bpf_obj_unpin_uptrs(rec, i, obj); 239 return err; 240 } 241 242 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, 243 void *key, void *value, __u64 flags) 244 { 245 int err; 246 247 /* Need to create a kthread, thus must support schedule */ 248 if (bpf_map_is_offloaded(map)) { 249 return bpf_map_offload_update_elem(map, key, value, flags); 250 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || 251 map->map_type == BPF_MAP_TYPE_ARENA || 252 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 253 return map->ops->map_update_elem(map, key, value, flags); 254 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || 255 map->map_type == BPF_MAP_TYPE_SOCKMAP) { 256 return sock_map_update_elem_sys(map, key, value, flags); 257 } else if (IS_FD_PROG_ARRAY(map)) { 258 return bpf_fd_array_map_update_elem(map, map_file, key, value, 259 flags); 260 } 261 262 bpf_disable_instrumentation(); 263 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 264 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 265 err = bpf_percpu_hash_update(map, key, value, flags); 266 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 267 err = bpf_percpu_array_update(map, key, value, flags); 268 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 269 err = bpf_percpu_cgroup_storage_update(map, key, value, 270 flags); 271 } else if (IS_FD_ARRAY(map)) { 272 err = bpf_fd_array_map_update_elem(map, map_file, key, value, 273 flags); 274 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 275 err = bpf_fd_htab_map_update_elem(map, map_file, key, value, 276 flags); 277 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 278 /* rcu_read_lock() is not needed */ 279 err = bpf_fd_reuseport_array_update_elem(map, key, value, 280 flags); 281 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 282 map->map_type == BPF_MAP_TYPE_STACK || 283 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 284 err = map->ops->map_push_elem(map, value, flags); 285 } else { 286 err = bpf_obj_pin_uptrs(map->record, value); 287 if (!err) { 288 rcu_read_lock(); 289 err = map->ops->map_update_elem(map, key, value, flags); 290 rcu_read_unlock(); 291 if (err) 292 bpf_obj_unpin_uptrs(map->record, value); 293 } 294 } 295 bpf_enable_instrumentation(); 296 297 return err; 298 } 299 300 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, 301 __u64 flags) 302 { 303 void *ptr; 304 int err; 305 306 if (bpf_map_is_offloaded(map)) 307 return bpf_map_offload_lookup_elem(map, key, value); 308 309 bpf_disable_instrumentation(); 310 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 311 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 312 err = bpf_percpu_hash_copy(map, key, value); 313 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 314 err = bpf_percpu_array_copy(map, key, value); 315 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 316 err = bpf_percpu_cgroup_storage_copy(map, key, value); 317 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 318 err = bpf_stackmap_copy(map, key, value); 319 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { 320 err = bpf_fd_array_map_lookup_elem(map, key, value); 321 } else if (IS_FD_HASH(map)) { 322 err = bpf_fd_htab_map_lookup_elem(map, key, value); 323 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 324 err = bpf_fd_reuseport_array_lookup_elem(map, key, value); 325 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 326 map->map_type == BPF_MAP_TYPE_STACK || 327 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 328 err = map->ops->map_peek_elem(map, value); 329 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 330 /* struct_ops map requires directly updating "value" */ 331 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value); 332 } else { 333 rcu_read_lock(); 334 if (map->ops->map_lookup_elem_sys_only) 335 ptr = map->ops->map_lookup_elem_sys_only(map, key); 336 else 337 ptr = map->ops->map_lookup_elem(map, key); 338 if (IS_ERR(ptr)) { 339 err = PTR_ERR(ptr); 340 } else if (!ptr) { 341 err = -ENOENT; 342 } else { 343 err = 0; 344 if (flags & BPF_F_LOCK) 345 /* lock 'ptr' and copy everything but lock */ 346 copy_map_value_locked(map, value, ptr, true); 347 else 348 copy_map_value(map, value, ptr); 349 /* mask lock and timer, since value wasn't zero inited */ 350 check_and_init_map_value(map, value); 351 } 352 rcu_read_unlock(); 353 } 354 355 bpf_enable_instrumentation(); 356 357 return err; 358 } 359 360 /* Please, do not use this function outside from the map creation path 361 * (e.g. in map update path) without taking care of setting the active 362 * memory cgroup (see at bpf_map_kmalloc_node() for example). 363 */ 364 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) 365 { 366 /* We really just want to fail instead of triggering OOM killer 367 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, 368 * which is used for lower order allocation requests. 369 * 370 * It has been observed that higher order allocation requests done by 371 * vmalloc with __GFP_NORETRY being set might fail due to not trying 372 * to reclaim memory from the page cache, thus we set 373 * __GFP_RETRY_MAYFAIL to avoid such situations. 374 */ 375 376 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO); 377 unsigned int flags = 0; 378 unsigned long align = 1; 379 void *area; 380 381 if (size >= SIZE_MAX) 382 return NULL; 383 384 /* kmalloc()'ed memory can't be mmap()'ed */ 385 if (mmapable) { 386 BUG_ON(!PAGE_ALIGNED(size)); 387 align = SHMLBA; 388 flags = VM_USERMAP; 389 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { 390 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, 391 numa_node); 392 if (area != NULL) 393 return area; 394 } 395 396 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 397 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, 398 flags, numa_node, __builtin_return_address(0)); 399 } 400 401 void *bpf_map_area_alloc(u64 size, int numa_node) 402 { 403 return __bpf_map_area_alloc(size, numa_node, false); 404 } 405 406 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) 407 { 408 return __bpf_map_area_alloc(size, numa_node, true); 409 } 410 411 void bpf_map_area_free(void *area) 412 { 413 kvfree(area); 414 } 415 416 static u32 bpf_map_flags_retain_permanent(u32 flags) 417 { 418 /* Some map creation flags are not tied to the map object but 419 * rather to the map fd instead, so they have no meaning upon 420 * map object inspection since multiple file descriptors with 421 * different (access) properties can exist here. Thus, given 422 * this has zero meaning for the map itself, lets clear these 423 * from here. 424 */ 425 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); 426 } 427 428 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) 429 { 430 map->map_type = attr->map_type; 431 map->key_size = attr->key_size; 432 map->value_size = attr->value_size; 433 map->max_entries = attr->max_entries; 434 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); 435 map->numa_node = bpf_map_attr_numa_node(attr); 436 map->map_extra = attr->map_extra; 437 } 438 439 static int bpf_map_alloc_id(struct bpf_map *map) 440 { 441 int id; 442 443 idr_preload(GFP_KERNEL); 444 spin_lock_bh(&map_idr_lock); 445 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); 446 if (id > 0) 447 map->id = id; 448 spin_unlock_bh(&map_idr_lock); 449 idr_preload_end(); 450 451 if (WARN_ON_ONCE(!id)) 452 return -ENOSPC; 453 454 return id > 0 ? 0 : id; 455 } 456 457 void bpf_map_free_id(struct bpf_map *map) 458 { 459 unsigned long flags; 460 461 /* Offloaded maps are removed from the IDR store when their device 462 * disappears - even if someone holds an fd to them they are unusable, 463 * the memory is gone, all ops will fail; they are simply waiting for 464 * refcnt to drop to be freed. 465 */ 466 if (!map->id) 467 return; 468 469 spin_lock_irqsave(&map_idr_lock, flags); 470 471 idr_remove(&map_idr, map->id); 472 map->id = 0; 473 474 spin_unlock_irqrestore(&map_idr_lock, flags); 475 } 476 477 #ifdef CONFIG_MEMCG 478 static void bpf_map_save_memcg(struct bpf_map *map) 479 { 480 /* Currently if a map is created by a process belonging to the root 481 * memory cgroup, get_obj_cgroup_from_current() will return NULL. 482 * So we have to check map->objcg for being NULL each time it's 483 * being used. 484 */ 485 if (memcg_bpf_enabled()) 486 map->objcg = get_obj_cgroup_from_current(); 487 } 488 489 static void bpf_map_release_memcg(struct bpf_map *map) 490 { 491 if (map->objcg) 492 obj_cgroup_put(map->objcg); 493 } 494 495 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) 496 { 497 if (map->objcg) 498 return get_mem_cgroup_from_objcg(map->objcg); 499 500 return root_mem_cgroup; 501 } 502 503 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, 504 int node) 505 { 506 struct mem_cgroup *memcg, *old_memcg; 507 void *ptr; 508 509 memcg = bpf_map_get_memcg(map); 510 old_memcg = set_active_memcg(memcg); 511 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); 512 set_active_memcg(old_memcg); 513 mem_cgroup_put(memcg); 514 515 return ptr; 516 } 517 518 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) 519 { 520 struct mem_cgroup *memcg, *old_memcg; 521 void *ptr; 522 523 memcg = bpf_map_get_memcg(map); 524 old_memcg = set_active_memcg(memcg); 525 ptr = kzalloc(size, flags | __GFP_ACCOUNT); 526 set_active_memcg(old_memcg); 527 mem_cgroup_put(memcg); 528 529 return ptr; 530 } 531 532 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, 533 gfp_t flags) 534 { 535 struct mem_cgroup *memcg, *old_memcg; 536 void *ptr; 537 538 memcg = bpf_map_get_memcg(map); 539 old_memcg = set_active_memcg(memcg); 540 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); 541 set_active_memcg(old_memcg); 542 mem_cgroup_put(memcg); 543 544 return ptr; 545 } 546 547 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, 548 size_t align, gfp_t flags) 549 { 550 struct mem_cgroup *memcg, *old_memcg; 551 void __percpu *ptr; 552 553 memcg = bpf_map_get_memcg(map); 554 old_memcg = set_active_memcg(memcg); 555 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); 556 set_active_memcg(old_memcg); 557 mem_cgroup_put(memcg); 558 559 return ptr; 560 } 561 562 #else 563 static void bpf_map_save_memcg(struct bpf_map *map) 564 { 565 } 566 567 static void bpf_map_release_memcg(struct bpf_map *map) 568 { 569 } 570 #endif 571 572 int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid, 573 unsigned long nr_pages, struct page **pages) 574 { 575 unsigned long i, j; 576 struct page *pg; 577 int ret = 0; 578 #ifdef CONFIG_MEMCG 579 struct mem_cgroup *memcg, *old_memcg; 580 581 memcg = bpf_map_get_memcg(map); 582 old_memcg = set_active_memcg(memcg); 583 #endif 584 for (i = 0; i < nr_pages; i++) { 585 pg = alloc_pages_node(nid, gfp | __GFP_ACCOUNT, 0); 586 587 if (pg) { 588 pages[i] = pg; 589 continue; 590 } 591 for (j = 0; j < i; j++) 592 __free_page(pages[j]); 593 ret = -ENOMEM; 594 break; 595 } 596 597 #ifdef CONFIG_MEMCG 598 set_active_memcg(old_memcg); 599 mem_cgroup_put(memcg); 600 #endif 601 return ret; 602 } 603 604 605 static int btf_field_cmp(const void *a, const void *b) 606 { 607 const struct btf_field *f1 = a, *f2 = b; 608 609 if (f1->offset < f2->offset) 610 return -1; 611 else if (f1->offset > f2->offset) 612 return 1; 613 return 0; 614 } 615 616 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 617 u32 field_mask) 618 { 619 struct btf_field *field; 620 621 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 622 return NULL; 623 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 624 if (!field || !(field->type & field_mask)) 625 return NULL; 626 return field; 627 } 628 629 void btf_record_free(struct btf_record *rec) 630 { 631 int i; 632 633 if (IS_ERR_OR_NULL(rec)) 634 return; 635 for (i = 0; i < rec->cnt; i++) { 636 switch (rec->fields[i].type) { 637 case BPF_KPTR_UNREF: 638 case BPF_KPTR_REF: 639 case BPF_KPTR_PERCPU: 640 case BPF_UPTR: 641 if (rec->fields[i].kptr.module) 642 module_put(rec->fields[i].kptr.module); 643 if (btf_is_kernel(rec->fields[i].kptr.btf)) 644 btf_put(rec->fields[i].kptr.btf); 645 break; 646 case BPF_LIST_HEAD: 647 case BPF_LIST_NODE: 648 case BPF_RB_ROOT: 649 case BPF_RB_NODE: 650 case BPF_SPIN_LOCK: 651 case BPF_TIMER: 652 case BPF_REFCOUNT: 653 case BPF_WORKQUEUE: 654 /* Nothing to release */ 655 break; 656 default: 657 WARN_ON_ONCE(1); 658 continue; 659 } 660 } 661 kfree(rec); 662 } 663 664 void bpf_map_free_record(struct bpf_map *map) 665 { 666 btf_record_free(map->record); 667 map->record = NULL; 668 } 669 670 struct btf_record *btf_record_dup(const struct btf_record *rec) 671 { 672 const struct btf_field *fields; 673 struct btf_record *new_rec; 674 int ret, size, i; 675 676 if (IS_ERR_OR_NULL(rec)) 677 return NULL; 678 size = offsetof(struct btf_record, fields[rec->cnt]); 679 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 680 if (!new_rec) 681 return ERR_PTR(-ENOMEM); 682 /* Do a deep copy of the btf_record */ 683 fields = rec->fields; 684 new_rec->cnt = 0; 685 for (i = 0; i < rec->cnt; i++) { 686 switch (fields[i].type) { 687 case BPF_KPTR_UNREF: 688 case BPF_KPTR_REF: 689 case BPF_KPTR_PERCPU: 690 case BPF_UPTR: 691 if (btf_is_kernel(fields[i].kptr.btf)) 692 btf_get(fields[i].kptr.btf); 693 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 694 ret = -ENXIO; 695 goto free; 696 } 697 break; 698 case BPF_LIST_HEAD: 699 case BPF_LIST_NODE: 700 case BPF_RB_ROOT: 701 case BPF_RB_NODE: 702 case BPF_SPIN_LOCK: 703 case BPF_TIMER: 704 case BPF_REFCOUNT: 705 case BPF_WORKQUEUE: 706 /* Nothing to acquire */ 707 break; 708 default: 709 ret = -EFAULT; 710 WARN_ON_ONCE(1); 711 goto free; 712 } 713 new_rec->cnt++; 714 } 715 return new_rec; 716 free: 717 btf_record_free(new_rec); 718 return ERR_PTR(ret); 719 } 720 721 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 722 { 723 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 724 int size; 725 726 if (!a_has_fields && !b_has_fields) 727 return true; 728 if (a_has_fields != b_has_fields) 729 return false; 730 if (rec_a->cnt != rec_b->cnt) 731 return false; 732 size = offsetof(struct btf_record, fields[rec_a->cnt]); 733 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 734 * members are zeroed out. So memcmp is safe to do without worrying 735 * about padding/unused fields. 736 * 737 * While spin_lock, timer, and kptr have no relation to map BTF, 738 * list_head metadata is specific to map BTF, the btf and value_rec 739 * members in particular. btf is the map BTF, while value_rec points to 740 * btf_record in that map BTF. 741 * 742 * So while by default, we don't rely on the map BTF (which the records 743 * were parsed from) matching for both records, which is not backwards 744 * compatible, in case list_head is part of it, we implicitly rely on 745 * that by way of depending on memcmp succeeding for it. 746 */ 747 return !memcmp(rec_a, rec_b, size); 748 } 749 750 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 751 { 752 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 753 return; 754 bpf_timer_cancel_and_free(obj + rec->timer_off); 755 } 756 757 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj) 758 { 759 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE))) 760 return; 761 bpf_wq_cancel_and_free(obj + rec->wq_off); 762 } 763 764 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 765 { 766 const struct btf_field *fields; 767 int i; 768 769 if (IS_ERR_OR_NULL(rec)) 770 return; 771 fields = rec->fields; 772 for (i = 0; i < rec->cnt; i++) { 773 struct btf_struct_meta *pointee_struct_meta; 774 const struct btf_field *field = &fields[i]; 775 void *field_ptr = obj + field->offset; 776 void *xchgd_field; 777 778 switch (fields[i].type) { 779 case BPF_SPIN_LOCK: 780 break; 781 case BPF_TIMER: 782 bpf_timer_cancel_and_free(field_ptr); 783 break; 784 case BPF_WORKQUEUE: 785 bpf_wq_cancel_and_free(field_ptr); 786 break; 787 case BPF_KPTR_UNREF: 788 WRITE_ONCE(*(u64 *)field_ptr, 0); 789 break; 790 case BPF_KPTR_REF: 791 case BPF_KPTR_PERCPU: 792 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); 793 if (!xchgd_field) 794 break; 795 796 if (!btf_is_kernel(field->kptr.btf)) { 797 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, 798 field->kptr.btf_id); 799 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? 800 pointee_struct_meta->record : NULL, 801 fields[i].type == BPF_KPTR_PERCPU); 802 } else { 803 field->kptr.dtor(xchgd_field); 804 } 805 break; 806 case BPF_UPTR: 807 /* The caller ensured that no one is using the uptr */ 808 unpin_uptr_kaddr(*(void **)field_ptr); 809 break; 810 case BPF_LIST_HEAD: 811 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 812 continue; 813 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 814 break; 815 case BPF_RB_ROOT: 816 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 817 continue; 818 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); 819 break; 820 case BPF_LIST_NODE: 821 case BPF_RB_NODE: 822 case BPF_REFCOUNT: 823 break; 824 default: 825 WARN_ON_ONCE(1); 826 continue; 827 } 828 } 829 } 830 831 static void bpf_map_free(struct bpf_map *map) 832 { 833 struct btf_record *rec = map->record; 834 struct btf *btf = map->btf; 835 836 /* implementation dependent freeing. Disabling migration to simplify 837 * the free of values or special fields allocated from bpf memory 838 * allocator. 839 */ 840 migrate_disable(); 841 map->ops->map_free(map); 842 migrate_enable(); 843 844 /* Delay freeing of btf_record for maps, as map_free 845 * callback usually needs access to them. It is better to do it here 846 * than require each callback to do the free itself manually. 847 * 848 * Note that the btf_record stashed in map->inner_map_meta->record was 849 * already freed using the map_free callback for map in map case which 850 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 851 * template bpf_map struct used during verification. 852 */ 853 btf_record_free(rec); 854 /* Delay freeing of btf for maps, as map_free callback may need 855 * struct_meta info which will be freed with btf_put(). 856 */ 857 btf_put(btf); 858 } 859 860 /* called from workqueue */ 861 static void bpf_map_free_deferred(struct work_struct *work) 862 { 863 struct bpf_map *map = container_of(work, struct bpf_map, work); 864 865 security_bpf_map_free(map); 866 bpf_map_release_memcg(map); 867 bpf_map_free(map); 868 } 869 870 static void bpf_map_put_uref(struct bpf_map *map) 871 { 872 if (atomic64_dec_and_test(&map->usercnt)) { 873 if (map->ops->map_release_uref) 874 map->ops->map_release_uref(map); 875 } 876 } 877 878 static void bpf_map_free_in_work(struct bpf_map *map) 879 { 880 INIT_WORK(&map->work, bpf_map_free_deferred); 881 /* Avoid spawning kworkers, since they all might contend 882 * for the same mutex like slab_mutex. 883 */ 884 queue_work(system_unbound_wq, &map->work); 885 } 886 887 static void bpf_map_free_rcu_gp(struct rcu_head *rcu) 888 { 889 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); 890 } 891 892 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu) 893 { 894 if (rcu_trace_implies_rcu_gp()) 895 bpf_map_free_rcu_gp(rcu); 896 else 897 call_rcu(rcu, bpf_map_free_rcu_gp); 898 } 899 900 /* decrement map refcnt and schedule it for freeing via workqueue 901 * (underlying map implementation ops->map_free() might sleep) 902 */ 903 void bpf_map_put(struct bpf_map *map) 904 { 905 if (atomic64_dec_and_test(&map->refcnt)) { 906 /* bpf_map_free_id() must be called first */ 907 bpf_map_free_id(map); 908 909 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); 910 if (READ_ONCE(map->free_after_mult_rcu_gp)) 911 call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp); 912 else if (READ_ONCE(map->free_after_rcu_gp)) 913 call_rcu(&map->rcu, bpf_map_free_rcu_gp); 914 else 915 bpf_map_free_in_work(map); 916 } 917 } 918 EXPORT_SYMBOL_GPL(bpf_map_put); 919 920 void bpf_map_put_with_uref(struct bpf_map *map) 921 { 922 bpf_map_put_uref(map); 923 bpf_map_put(map); 924 } 925 926 static int bpf_map_release(struct inode *inode, struct file *filp) 927 { 928 struct bpf_map *map = filp->private_data; 929 930 if (map->ops->map_release) 931 map->ops->map_release(map, filp); 932 933 bpf_map_put_with_uref(map); 934 return 0; 935 } 936 937 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 938 { 939 fmode_t mode = fd_file(f)->f_mode; 940 941 /* Our file permissions may have been overridden by global 942 * map permissions facing syscall side. 943 */ 944 if (READ_ONCE(map->frozen)) 945 mode &= ~FMODE_CAN_WRITE; 946 return mode; 947 } 948 949 #ifdef CONFIG_PROC_FS 950 /* Show the memory usage of a bpf map */ 951 static u64 bpf_map_memory_usage(const struct bpf_map *map) 952 { 953 return map->ops->map_mem_usage(map); 954 } 955 956 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 957 { 958 struct bpf_map *map = filp->private_data; 959 u32 type = 0, jited = 0; 960 961 if (map_type_contains_progs(map)) { 962 spin_lock(&map->owner.lock); 963 type = map->owner.type; 964 jited = map->owner.jited; 965 spin_unlock(&map->owner.lock); 966 } 967 968 seq_printf(m, 969 "map_type:\t%u\n" 970 "key_size:\t%u\n" 971 "value_size:\t%u\n" 972 "max_entries:\t%u\n" 973 "map_flags:\t%#x\n" 974 "map_extra:\t%#llx\n" 975 "memlock:\t%llu\n" 976 "map_id:\t%u\n" 977 "frozen:\t%u\n", 978 map->map_type, 979 map->key_size, 980 map->value_size, 981 map->max_entries, 982 map->map_flags, 983 (unsigned long long)map->map_extra, 984 bpf_map_memory_usage(map), 985 map->id, 986 READ_ONCE(map->frozen)); 987 if (type) { 988 seq_printf(m, "owner_prog_type:\t%u\n", type); 989 seq_printf(m, "owner_jited:\t%u\n", jited); 990 } 991 } 992 #endif 993 994 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 995 loff_t *ppos) 996 { 997 /* We need this handler such that alloc_file() enables 998 * f_mode with FMODE_CAN_READ. 999 */ 1000 return -EINVAL; 1001 } 1002 1003 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 1004 size_t siz, loff_t *ppos) 1005 { 1006 /* We need this handler such that alloc_file() enables 1007 * f_mode with FMODE_CAN_WRITE. 1008 */ 1009 return -EINVAL; 1010 } 1011 1012 /* called for any extra memory-mapped regions (except initial) */ 1013 static void bpf_map_mmap_open(struct vm_area_struct *vma) 1014 { 1015 struct bpf_map *map = vma->vm_file->private_data; 1016 1017 if (vma->vm_flags & VM_MAYWRITE) 1018 bpf_map_write_active_inc(map); 1019 } 1020 1021 /* called for all unmapped memory region (including initial) */ 1022 static void bpf_map_mmap_close(struct vm_area_struct *vma) 1023 { 1024 struct bpf_map *map = vma->vm_file->private_data; 1025 1026 if (vma->vm_flags & VM_MAYWRITE) 1027 bpf_map_write_active_dec(map); 1028 } 1029 1030 static const struct vm_operations_struct bpf_map_default_vmops = { 1031 .open = bpf_map_mmap_open, 1032 .close = bpf_map_mmap_close, 1033 }; 1034 1035 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 1036 { 1037 struct bpf_map *map = filp->private_data; 1038 int err = 0; 1039 1040 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 1041 return -ENOTSUPP; 1042 1043 if (!(vma->vm_flags & VM_SHARED)) 1044 return -EINVAL; 1045 1046 mutex_lock(&map->freeze_mutex); 1047 1048 if (vma->vm_flags & VM_WRITE) { 1049 if (map->frozen) { 1050 err = -EPERM; 1051 goto out; 1052 } 1053 /* map is meant to be read-only, so do not allow mapping as 1054 * writable, because it's possible to leak a writable page 1055 * reference and allows user-space to still modify it after 1056 * freezing, while verifier will assume contents do not change 1057 */ 1058 if (map->map_flags & BPF_F_RDONLY_PROG) { 1059 err = -EACCES; 1060 goto out; 1061 } 1062 bpf_map_write_active_inc(map); 1063 } 1064 out: 1065 mutex_unlock(&map->freeze_mutex); 1066 if (err) 1067 return err; 1068 1069 /* set default open/close callbacks */ 1070 vma->vm_ops = &bpf_map_default_vmops; 1071 vma->vm_private_data = map; 1072 vm_flags_clear(vma, VM_MAYEXEC); 1073 /* If mapping is read-only, then disallow potentially re-mapping with 1074 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing 1075 * means that as far as BPF map's memory-mapped VMAs are concerned, 1076 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set, 1077 * both should be set, so we can forget about VM_MAYWRITE and always 1078 * check just VM_WRITE 1079 */ 1080 if (!(vma->vm_flags & VM_WRITE)) 1081 vm_flags_clear(vma, VM_MAYWRITE); 1082 1083 err = map->ops->map_mmap(map, vma); 1084 if (err) { 1085 if (vma->vm_flags & VM_WRITE) 1086 bpf_map_write_active_dec(map); 1087 } 1088 1089 return err; 1090 } 1091 1092 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 1093 { 1094 struct bpf_map *map = filp->private_data; 1095 1096 if (map->ops->map_poll) 1097 return map->ops->map_poll(map, filp, pts); 1098 1099 return EPOLLERR; 1100 } 1101 1102 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr, 1103 unsigned long len, unsigned long pgoff, 1104 unsigned long flags) 1105 { 1106 struct bpf_map *map = filp->private_data; 1107 1108 if (map->ops->map_get_unmapped_area) 1109 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); 1110 #ifdef CONFIG_MMU 1111 return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags); 1112 #else 1113 return addr; 1114 #endif 1115 } 1116 1117 const struct file_operations bpf_map_fops = { 1118 #ifdef CONFIG_PROC_FS 1119 .show_fdinfo = bpf_map_show_fdinfo, 1120 #endif 1121 .release = bpf_map_release, 1122 .read = bpf_dummy_read, 1123 .write = bpf_dummy_write, 1124 .mmap = bpf_map_mmap, 1125 .poll = bpf_map_poll, 1126 .get_unmapped_area = bpf_get_unmapped_area, 1127 }; 1128 1129 int bpf_map_new_fd(struct bpf_map *map, int flags) 1130 { 1131 int ret; 1132 1133 ret = security_bpf_map(map, OPEN_FMODE(flags)); 1134 if (ret < 0) 1135 return ret; 1136 1137 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 1138 flags | O_CLOEXEC); 1139 } 1140 1141 int bpf_get_file_flag(int flags) 1142 { 1143 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 1144 return -EINVAL; 1145 if (flags & BPF_F_RDONLY) 1146 return O_RDONLY; 1147 if (flags & BPF_F_WRONLY) 1148 return O_WRONLY; 1149 return O_RDWR; 1150 } 1151 1152 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 1153 #define CHECK_ATTR(CMD) \ 1154 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 1155 sizeof(attr->CMD##_LAST_FIELD), 0, \ 1156 sizeof(*attr) - \ 1157 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 1158 sizeof(attr->CMD##_LAST_FIELD)) != NULL 1159 1160 /* dst and src must have at least "size" number of bytes. 1161 * Return strlen on success and < 0 on error. 1162 */ 1163 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 1164 { 1165 const char *end = src + size; 1166 const char *orig_src = src; 1167 1168 memset(dst, 0, size); 1169 /* Copy all isalnum(), '_' and '.' chars. */ 1170 while (src < end && *src) { 1171 if (!isalnum(*src) && 1172 *src != '_' && *src != '.') 1173 return -EINVAL; 1174 *dst++ = *src++; 1175 } 1176 1177 /* No '\0' found in "size" number of bytes */ 1178 if (src == end) 1179 return -EINVAL; 1180 1181 return src - orig_src; 1182 } 1183 1184 int map_check_no_btf(const struct bpf_map *map, 1185 const struct btf *btf, 1186 const struct btf_type *key_type, 1187 const struct btf_type *value_type) 1188 { 1189 return -ENOTSUPP; 1190 } 1191 1192 static int map_check_btf(struct bpf_map *map, struct bpf_token *token, 1193 const struct btf *btf, u32 btf_key_id, u32 btf_value_id) 1194 { 1195 const struct btf_type *key_type, *value_type; 1196 u32 key_size, value_size; 1197 int ret = 0; 1198 1199 /* Some maps allow key to be unspecified. */ 1200 if (btf_key_id) { 1201 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 1202 if (!key_type || key_size != map->key_size) 1203 return -EINVAL; 1204 } else { 1205 key_type = btf_type_by_id(btf, 0); 1206 if (!map->ops->map_check_btf) 1207 return -EINVAL; 1208 } 1209 1210 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1211 if (!value_type || value_size != map->value_size) 1212 return -EINVAL; 1213 1214 map->record = btf_parse_fields(btf, value_type, 1215 BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1216 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR, 1217 map->value_size); 1218 if (!IS_ERR_OR_NULL(map->record)) { 1219 int i; 1220 1221 if (!bpf_token_capable(token, CAP_BPF)) { 1222 ret = -EPERM; 1223 goto free_map_tab; 1224 } 1225 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1226 ret = -EACCES; 1227 goto free_map_tab; 1228 } 1229 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1230 switch (map->record->field_mask & (1 << i)) { 1231 case 0: 1232 continue; 1233 case BPF_SPIN_LOCK: 1234 if (map->map_type != BPF_MAP_TYPE_HASH && 1235 map->map_type != BPF_MAP_TYPE_ARRAY && 1236 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1237 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1238 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1239 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1240 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1241 ret = -EOPNOTSUPP; 1242 goto free_map_tab; 1243 } 1244 break; 1245 case BPF_TIMER: 1246 case BPF_WORKQUEUE: 1247 if (map->map_type != BPF_MAP_TYPE_HASH && 1248 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1249 map->map_type != BPF_MAP_TYPE_ARRAY) { 1250 ret = -EOPNOTSUPP; 1251 goto free_map_tab; 1252 } 1253 break; 1254 case BPF_KPTR_UNREF: 1255 case BPF_KPTR_REF: 1256 case BPF_KPTR_PERCPU: 1257 case BPF_REFCOUNT: 1258 if (map->map_type != BPF_MAP_TYPE_HASH && 1259 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1260 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1261 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1262 map->map_type != BPF_MAP_TYPE_ARRAY && 1263 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1264 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1265 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1266 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1267 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1268 ret = -EOPNOTSUPP; 1269 goto free_map_tab; 1270 } 1271 break; 1272 case BPF_UPTR: 1273 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { 1274 ret = -EOPNOTSUPP; 1275 goto free_map_tab; 1276 } 1277 break; 1278 case BPF_LIST_HEAD: 1279 case BPF_RB_ROOT: 1280 if (map->map_type != BPF_MAP_TYPE_HASH && 1281 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1282 map->map_type != BPF_MAP_TYPE_ARRAY) { 1283 ret = -EOPNOTSUPP; 1284 goto free_map_tab; 1285 } 1286 break; 1287 default: 1288 /* Fail if map_type checks are missing for a field type */ 1289 ret = -EOPNOTSUPP; 1290 goto free_map_tab; 1291 } 1292 } 1293 } 1294 1295 ret = btf_check_and_fixup_fields(btf, map->record); 1296 if (ret < 0) 1297 goto free_map_tab; 1298 1299 if (map->ops->map_check_btf) { 1300 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1301 if (ret < 0) 1302 goto free_map_tab; 1303 } 1304 1305 return ret; 1306 free_map_tab: 1307 bpf_map_free_record(map); 1308 return ret; 1309 } 1310 1311 static bool bpf_net_capable(void) 1312 { 1313 return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN); 1314 } 1315 1316 #define BPF_MAP_CREATE_LAST_FIELD map_token_fd 1317 /* called via syscall */ 1318 static int map_create(union bpf_attr *attr, bool kernel) 1319 { 1320 const struct bpf_map_ops *ops; 1321 struct bpf_token *token = NULL; 1322 int numa_node = bpf_map_attr_numa_node(attr); 1323 u32 map_type = attr->map_type; 1324 struct bpf_map *map; 1325 bool token_flag; 1326 int f_flags; 1327 int err; 1328 1329 err = CHECK_ATTR(BPF_MAP_CREATE); 1330 if (err) 1331 return -EINVAL; 1332 1333 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it 1334 * to avoid per-map type checks tripping on unknown flag 1335 */ 1336 token_flag = attr->map_flags & BPF_F_TOKEN_FD; 1337 attr->map_flags &= ~BPF_F_TOKEN_FD; 1338 1339 if (attr->btf_vmlinux_value_type_id) { 1340 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || 1341 attr->btf_key_type_id || attr->btf_value_type_id) 1342 return -EINVAL; 1343 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1344 return -EINVAL; 1345 } 1346 1347 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1348 attr->map_type != BPF_MAP_TYPE_ARENA && 1349 attr->map_extra != 0) 1350 return -EINVAL; 1351 1352 f_flags = bpf_get_file_flag(attr->map_flags); 1353 if (f_flags < 0) 1354 return f_flags; 1355 1356 if (numa_node != NUMA_NO_NODE && 1357 ((unsigned int)numa_node >= nr_node_ids || 1358 !node_online(numa_node))) 1359 return -EINVAL; 1360 1361 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1362 map_type = attr->map_type; 1363 if (map_type >= ARRAY_SIZE(bpf_map_types)) 1364 return -EINVAL; 1365 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1366 ops = bpf_map_types[map_type]; 1367 if (!ops) 1368 return -EINVAL; 1369 1370 if (ops->map_alloc_check) { 1371 err = ops->map_alloc_check(attr); 1372 if (err) 1373 return err; 1374 } 1375 if (attr->map_ifindex) 1376 ops = &bpf_map_offload_ops; 1377 if (!ops->map_mem_usage) 1378 return -EINVAL; 1379 1380 if (token_flag) { 1381 token = bpf_token_get_from_fd(attr->map_token_fd); 1382 if (IS_ERR(token)) 1383 return PTR_ERR(token); 1384 1385 /* if current token doesn't grant map creation permissions, 1386 * then we can't use this token, so ignore it and rely on 1387 * system-wide capabilities checks 1388 */ 1389 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || 1390 !bpf_token_allow_map_type(token, attr->map_type)) { 1391 bpf_token_put(token); 1392 token = NULL; 1393 } 1394 } 1395 1396 err = -EPERM; 1397 1398 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1399 * creation for unprivileged users; other actions depend 1400 * on fd availability and access to bpffs, so are dependent on 1401 * object creation success. Even with unprivileged BPF disabled, 1402 * capability checks are still carried out. 1403 */ 1404 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) 1405 goto put_token; 1406 1407 /* check privileged map type permissions */ 1408 switch (map_type) { 1409 case BPF_MAP_TYPE_ARRAY: 1410 case BPF_MAP_TYPE_PERCPU_ARRAY: 1411 case BPF_MAP_TYPE_PROG_ARRAY: 1412 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1413 case BPF_MAP_TYPE_CGROUP_ARRAY: 1414 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1415 case BPF_MAP_TYPE_HASH: 1416 case BPF_MAP_TYPE_PERCPU_HASH: 1417 case BPF_MAP_TYPE_HASH_OF_MAPS: 1418 case BPF_MAP_TYPE_RINGBUF: 1419 case BPF_MAP_TYPE_USER_RINGBUF: 1420 case BPF_MAP_TYPE_CGROUP_STORAGE: 1421 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1422 /* unprivileged */ 1423 break; 1424 case BPF_MAP_TYPE_SK_STORAGE: 1425 case BPF_MAP_TYPE_INODE_STORAGE: 1426 case BPF_MAP_TYPE_TASK_STORAGE: 1427 case BPF_MAP_TYPE_CGRP_STORAGE: 1428 case BPF_MAP_TYPE_BLOOM_FILTER: 1429 case BPF_MAP_TYPE_LPM_TRIE: 1430 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1431 case BPF_MAP_TYPE_STACK_TRACE: 1432 case BPF_MAP_TYPE_QUEUE: 1433 case BPF_MAP_TYPE_STACK: 1434 case BPF_MAP_TYPE_LRU_HASH: 1435 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1436 case BPF_MAP_TYPE_STRUCT_OPS: 1437 case BPF_MAP_TYPE_CPUMAP: 1438 case BPF_MAP_TYPE_ARENA: 1439 if (!bpf_token_capable(token, CAP_BPF)) 1440 goto put_token; 1441 break; 1442 case BPF_MAP_TYPE_SOCKMAP: 1443 case BPF_MAP_TYPE_SOCKHASH: 1444 case BPF_MAP_TYPE_DEVMAP: 1445 case BPF_MAP_TYPE_DEVMAP_HASH: 1446 case BPF_MAP_TYPE_XSKMAP: 1447 if (!bpf_token_capable(token, CAP_NET_ADMIN)) 1448 goto put_token; 1449 break; 1450 default: 1451 WARN(1, "unsupported map type %d", map_type); 1452 goto put_token; 1453 } 1454 1455 map = ops->map_alloc(attr); 1456 if (IS_ERR(map)) { 1457 err = PTR_ERR(map); 1458 goto put_token; 1459 } 1460 map->ops = ops; 1461 map->map_type = map_type; 1462 1463 err = bpf_obj_name_cpy(map->name, attr->map_name, 1464 sizeof(attr->map_name)); 1465 if (err < 0) 1466 goto free_map; 1467 1468 atomic64_set(&map->refcnt, 1); 1469 atomic64_set(&map->usercnt, 1); 1470 mutex_init(&map->freeze_mutex); 1471 spin_lock_init(&map->owner.lock); 1472 1473 if (attr->btf_key_type_id || attr->btf_value_type_id || 1474 /* Even the map's value is a kernel's struct, 1475 * the bpf_prog.o must have BTF to begin with 1476 * to figure out the corresponding kernel's 1477 * counter part. Thus, attr->btf_fd has 1478 * to be valid also. 1479 */ 1480 attr->btf_vmlinux_value_type_id) { 1481 struct btf *btf; 1482 1483 btf = btf_get_by_fd(attr->btf_fd); 1484 if (IS_ERR(btf)) { 1485 err = PTR_ERR(btf); 1486 goto free_map; 1487 } 1488 if (btf_is_kernel(btf)) { 1489 btf_put(btf); 1490 err = -EACCES; 1491 goto free_map; 1492 } 1493 map->btf = btf; 1494 1495 if (attr->btf_value_type_id) { 1496 err = map_check_btf(map, token, btf, attr->btf_key_type_id, 1497 attr->btf_value_type_id); 1498 if (err) 1499 goto free_map; 1500 } 1501 1502 map->btf_key_type_id = attr->btf_key_type_id; 1503 map->btf_value_type_id = attr->btf_value_type_id; 1504 map->btf_vmlinux_value_type_id = 1505 attr->btf_vmlinux_value_type_id; 1506 } 1507 1508 err = security_bpf_map_create(map, attr, token, kernel); 1509 if (err) 1510 goto free_map_sec; 1511 1512 err = bpf_map_alloc_id(map); 1513 if (err) 1514 goto free_map_sec; 1515 1516 bpf_map_save_memcg(map); 1517 bpf_token_put(token); 1518 1519 err = bpf_map_new_fd(map, f_flags); 1520 if (err < 0) { 1521 /* failed to allocate fd. 1522 * bpf_map_put_with_uref() is needed because the above 1523 * bpf_map_alloc_id() has published the map 1524 * to the userspace and the userspace may 1525 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1526 */ 1527 bpf_map_put_with_uref(map); 1528 return err; 1529 } 1530 1531 return err; 1532 1533 free_map_sec: 1534 security_bpf_map_free(map); 1535 free_map: 1536 bpf_map_free(map); 1537 put_token: 1538 bpf_token_put(token); 1539 return err; 1540 } 1541 1542 void bpf_map_inc(struct bpf_map *map) 1543 { 1544 atomic64_inc(&map->refcnt); 1545 } 1546 EXPORT_SYMBOL_GPL(bpf_map_inc); 1547 1548 void bpf_map_inc_with_uref(struct bpf_map *map) 1549 { 1550 atomic64_inc(&map->refcnt); 1551 atomic64_inc(&map->usercnt); 1552 } 1553 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1554 1555 struct bpf_map *bpf_map_get(u32 ufd) 1556 { 1557 CLASS(fd, f)(ufd); 1558 struct bpf_map *map = __bpf_map_get(f); 1559 1560 if (!IS_ERR(map)) 1561 bpf_map_inc(map); 1562 1563 return map; 1564 } 1565 EXPORT_SYMBOL(bpf_map_get); 1566 1567 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1568 { 1569 CLASS(fd, f)(ufd); 1570 struct bpf_map *map = __bpf_map_get(f); 1571 1572 if (!IS_ERR(map)) 1573 bpf_map_inc_with_uref(map); 1574 1575 return map; 1576 } 1577 1578 /* map_idr_lock should have been held or the map should have been 1579 * protected by rcu read lock. 1580 */ 1581 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1582 { 1583 int refold; 1584 1585 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1586 if (!refold) 1587 return ERR_PTR(-ENOENT); 1588 if (uref) 1589 atomic64_inc(&map->usercnt); 1590 1591 return map; 1592 } 1593 1594 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1595 { 1596 lockdep_assert(rcu_read_lock_held()); 1597 return __bpf_map_inc_not_zero(map, false); 1598 } 1599 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1600 1601 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) 1602 { 1603 return -ENOTSUPP; 1604 } 1605 1606 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1607 { 1608 if (key_size) 1609 return vmemdup_user(ukey, key_size); 1610 1611 if (ukey) 1612 return ERR_PTR(-EINVAL); 1613 1614 return NULL; 1615 } 1616 1617 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1618 { 1619 if (key_size) 1620 return kvmemdup_bpfptr(ukey, key_size); 1621 1622 if (!bpfptr_is_null(ukey)) 1623 return ERR_PTR(-EINVAL); 1624 1625 return NULL; 1626 } 1627 1628 /* last field in 'union bpf_attr' used by this command */ 1629 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1630 1631 static int map_lookup_elem(union bpf_attr *attr) 1632 { 1633 void __user *ukey = u64_to_user_ptr(attr->key); 1634 void __user *uvalue = u64_to_user_ptr(attr->value); 1635 struct bpf_map *map; 1636 void *key, *value; 1637 u32 value_size; 1638 int err; 1639 1640 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1641 return -EINVAL; 1642 1643 if (attr->flags & ~BPF_F_LOCK) 1644 return -EINVAL; 1645 1646 CLASS(fd, f)(attr->map_fd); 1647 map = __bpf_map_get(f); 1648 if (IS_ERR(map)) 1649 return PTR_ERR(map); 1650 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1651 return -EPERM; 1652 1653 if ((attr->flags & BPF_F_LOCK) && 1654 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 1655 return -EINVAL; 1656 1657 key = __bpf_copy_key(ukey, map->key_size); 1658 if (IS_ERR(key)) 1659 return PTR_ERR(key); 1660 1661 value_size = bpf_map_value_size(map); 1662 1663 err = -ENOMEM; 1664 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1665 if (!value) 1666 goto free_key; 1667 1668 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1669 if (copy_from_user(value, uvalue, value_size)) 1670 err = -EFAULT; 1671 else 1672 err = bpf_map_copy_value(map, key, value, attr->flags); 1673 goto free_value; 1674 } 1675 1676 err = bpf_map_copy_value(map, key, value, attr->flags); 1677 if (err) 1678 goto free_value; 1679 1680 err = -EFAULT; 1681 if (copy_to_user(uvalue, value, value_size) != 0) 1682 goto free_value; 1683 1684 err = 0; 1685 1686 free_value: 1687 kvfree(value); 1688 free_key: 1689 kvfree(key); 1690 return err; 1691 } 1692 1693 1694 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1695 1696 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1697 { 1698 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1699 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1700 struct bpf_map *map; 1701 void *key, *value; 1702 u32 value_size; 1703 int err; 1704 1705 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1706 return -EINVAL; 1707 1708 CLASS(fd, f)(attr->map_fd); 1709 map = __bpf_map_get(f); 1710 if (IS_ERR(map)) 1711 return PTR_ERR(map); 1712 bpf_map_write_active_inc(map); 1713 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1714 err = -EPERM; 1715 goto err_put; 1716 } 1717 1718 if ((attr->flags & BPF_F_LOCK) && 1719 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1720 err = -EINVAL; 1721 goto err_put; 1722 } 1723 1724 key = ___bpf_copy_key(ukey, map->key_size); 1725 if (IS_ERR(key)) { 1726 err = PTR_ERR(key); 1727 goto err_put; 1728 } 1729 1730 value_size = bpf_map_value_size(map); 1731 value = kvmemdup_bpfptr(uvalue, value_size); 1732 if (IS_ERR(value)) { 1733 err = PTR_ERR(value); 1734 goto free_key; 1735 } 1736 1737 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); 1738 if (!err) 1739 maybe_wait_bpf_programs(map); 1740 1741 kvfree(value); 1742 free_key: 1743 kvfree(key); 1744 err_put: 1745 bpf_map_write_active_dec(map); 1746 return err; 1747 } 1748 1749 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1750 1751 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1752 { 1753 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1754 struct bpf_map *map; 1755 void *key; 1756 int err; 1757 1758 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1759 return -EINVAL; 1760 1761 CLASS(fd, f)(attr->map_fd); 1762 map = __bpf_map_get(f); 1763 if (IS_ERR(map)) 1764 return PTR_ERR(map); 1765 bpf_map_write_active_inc(map); 1766 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1767 err = -EPERM; 1768 goto err_put; 1769 } 1770 1771 key = ___bpf_copy_key(ukey, map->key_size); 1772 if (IS_ERR(key)) { 1773 err = PTR_ERR(key); 1774 goto err_put; 1775 } 1776 1777 if (bpf_map_is_offloaded(map)) { 1778 err = bpf_map_offload_delete_elem(map, key); 1779 goto out; 1780 } else if (IS_FD_PROG_ARRAY(map) || 1781 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1782 /* These maps require sleepable context */ 1783 err = map->ops->map_delete_elem(map, key); 1784 goto out; 1785 } 1786 1787 bpf_disable_instrumentation(); 1788 rcu_read_lock(); 1789 err = map->ops->map_delete_elem(map, key); 1790 rcu_read_unlock(); 1791 bpf_enable_instrumentation(); 1792 if (!err) 1793 maybe_wait_bpf_programs(map); 1794 out: 1795 kvfree(key); 1796 err_put: 1797 bpf_map_write_active_dec(map); 1798 return err; 1799 } 1800 1801 /* last field in 'union bpf_attr' used by this command */ 1802 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1803 1804 static int map_get_next_key(union bpf_attr *attr) 1805 { 1806 void __user *ukey = u64_to_user_ptr(attr->key); 1807 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1808 struct bpf_map *map; 1809 void *key, *next_key; 1810 int err; 1811 1812 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1813 return -EINVAL; 1814 1815 CLASS(fd, f)(attr->map_fd); 1816 map = __bpf_map_get(f); 1817 if (IS_ERR(map)) 1818 return PTR_ERR(map); 1819 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1820 return -EPERM; 1821 1822 if (ukey) { 1823 key = __bpf_copy_key(ukey, map->key_size); 1824 if (IS_ERR(key)) 1825 return PTR_ERR(key); 1826 } else { 1827 key = NULL; 1828 } 1829 1830 err = -ENOMEM; 1831 next_key = kvmalloc(map->key_size, GFP_USER); 1832 if (!next_key) 1833 goto free_key; 1834 1835 if (bpf_map_is_offloaded(map)) { 1836 err = bpf_map_offload_get_next_key(map, key, next_key); 1837 goto out; 1838 } 1839 1840 rcu_read_lock(); 1841 err = map->ops->map_get_next_key(map, key, next_key); 1842 rcu_read_unlock(); 1843 out: 1844 if (err) 1845 goto free_next_key; 1846 1847 err = -EFAULT; 1848 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1849 goto free_next_key; 1850 1851 err = 0; 1852 1853 free_next_key: 1854 kvfree(next_key); 1855 free_key: 1856 kvfree(key); 1857 return err; 1858 } 1859 1860 int generic_map_delete_batch(struct bpf_map *map, 1861 const union bpf_attr *attr, 1862 union bpf_attr __user *uattr) 1863 { 1864 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1865 u32 cp, max_count; 1866 int err = 0; 1867 void *key; 1868 1869 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1870 return -EINVAL; 1871 1872 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1873 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1874 return -EINVAL; 1875 } 1876 1877 max_count = attr->batch.count; 1878 if (!max_count) 1879 return 0; 1880 1881 if (put_user(0, &uattr->batch.count)) 1882 return -EFAULT; 1883 1884 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1885 if (!key) 1886 return -ENOMEM; 1887 1888 for (cp = 0; cp < max_count; cp++) { 1889 err = -EFAULT; 1890 if (copy_from_user(key, keys + cp * map->key_size, 1891 map->key_size)) 1892 break; 1893 1894 if (bpf_map_is_offloaded(map)) { 1895 err = bpf_map_offload_delete_elem(map, key); 1896 break; 1897 } 1898 1899 bpf_disable_instrumentation(); 1900 rcu_read_lock(); 1901 err = map->ops->map_delete_elem(map, key); 1902 rcu_read_unlock(); 1903 bpf_enable_instrumentation(); 1904 if (err) 1905 break; 1906 cond_resched(); 1907 } 1908 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1909 err = -EFAULT; 1910 1911 kvfree(key); 1912 1913 return err; 1914 } 1915 1916 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 1917 const union bpf_attr *attr, 1918 union bpf_attr __user *uattr) 1919 { 1920 void __user *values = u64_to_user_ptr(attr->batch.values); 1921 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1922 u32 value_size, cp, max_count; 1923 void *key, *value; 1924 int err = 0; 1925 1926 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1927 return -EINVAL; 1928 1929 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1930 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1931 return -EINVAL; 1932 } 1933 1934 value_size = bpf_map_value_size(map); 1935 1936 max_count = attr->batch.count; 1937 if (!max_count) 1938 return 0; 1939 1940 if (put_user(0, &uattr->batch.count)) 1941 return -EFAULT; 1942 1943 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1944 if (!key) 1945 return -ENOMEM; 1946 1947 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1948 if (!value) { 1949 kvfree(key); 1950 return -ENOMEM; 1951 } 1952 1953 for (cp = 0; cp < max_count; cp++) { 1954 err = -EFAULT; 1955 if (copy_from_user(key, keys + cp * map->key_size, 1956 map->key_size) || 1957 copy_from_user(value, values + cp * value_size, value_size)) 1958 break; 1959 1960 err = bpf_map_update_value(map, map_file, key, value, 1961 attr->batch.elem_flags); 1962 1963 if (err) 1964 break; 1965 cond_resched(); 1966 } 1967 1968 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1969 err = -EFAULT; 1970 1971 kvfree(value); 1972 kvfree(key); 1973 1974 return err; 1975 } 1976 1977 int generic_map_lookup_batch(struct bpf_map *map, 1978 const union bpf_attr *attr, 1979 union bpf_attr __user *uattr) 1980 { 1981 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 1982 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 1983 void __user *values = u64_to_user_ptr(attr->batch.values); 1984 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1985 void *buf, *buf_prevkey, *prev_key, *key, *value; 1986 u32 value_size, cp, max_count; 1987 int err; 1988 1989 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1990 return -EINVAL; 1991 1992 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1993 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 1994 return -EINVAL; 1995 1996 value_size = bpf_map_value_size(map); 1997 1998 max_count = attr->batch.count; 1999 if (!max_count) 2000 return 0; 2001 2002 if (put_user(0, &uattr->batch.count)) 2003 return -EFAULT; 2004 2005 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2006 if (!buf_prevkey) 2007 return -ENOMEM; 2008 2009 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 2010 if (!buf) { 2011 kvfree(buf_prevkey); 2012 return -ENOMEM; 2013 } 2014 2015 err = -EFAULT; 2016 prev_key = NULL; 2017 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 2018 goto free_buf; 2019 key = buf; 2020 value = key + map->key_size; 2021 if (ubatch) 2022 prev_key = buf_prevkey; 2023 2024 for (cp = 0; cp < max_count;) { 2025 rcu_read_lock(); 2026 err = map->ops->map_get_next_key(map, prev_key, key); 2027 rcu_read_unlock(); 2028 if (err) 2029 break; 2030 err = bpf_map_copy_value(map, key, value, 2031 attr->batch.elem_flags); 2032 2033 if (err == -ENOENT) 2034 goto next_key; 2035 2036 if (err) 2037 goto free_buf; 2038 2039 if (copy_to_user(keys + cp * map->key_size, key, 2040 map->key_size)) { 2041 err = -EFAULT; 2042 goto free_buf; 2043 } 2044 if (copy_to_user(values + cp * value_size, value, value_size)) { 2045 err = -EFAULT; 2046 goto free_buf; 2047 } 2048 2049 cp++; 2050 next_key: 2051 if (!prev_key) 2052 prev_key = buf_prevkey; 2053 2054 swap(prev_key, key); 2055 cond_resched(); 2056 } 2057 2058 if (err == -EFAULT) 2059 goto free_buf; 2060 2061 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 2062 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 2063 err = -EFAULT; 2064 2065 free_buf: 2066 kvfree(buf_prevkey); 2067 kvfree(buf); 2068 return err; 2069 } 2070 2071 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 2072 2073 static int map_lookup_and_delete_elem(union bpf_attr *attr) 2074 { 2075 void __user *ukey = u64_to_user_ptr(attr->key); 2076 void __user *uvalue = u64_to_user_ptr(attr->value); 2077 struct bpf_map *map; 2078 void *key, *value; 2079 u32 value_size; 2080 int err; 2081 2082 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 2083 return -EINVAL; 2084 2085 if (attr->flags & ~BPF_F_LOCK) 2086 return -EINVAL; 2087 2088 CLASS(fd, f)(attr->map_fd); 2089 map = __bpf_map_get(f); 2090 if (IS_ERR(map)) 2091 return PTR_ERR(map); 2092 bpf_map_write_active_inc(map); 2093 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 2094 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2095 err = -EPERM; 2096 goto err_put; 2097 } 2098 2099 if (attr->flags && 2100 (map->map_type == BPF_MAP_TYPE_QUEUE || 2101 map->map_type == BPF_MAP_TYPE_STACK)) { 2102 err = -EINVAL; 2103 goto err_put; 2104 } 2105 2106 if ((attr->flags & BPF_F_LOCK) && 2107 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2108 err = -EINVAL; 2109 goto err_put; 2110 } 2111 2112 key = __bpf_copy_key(ukey, map->key_size); 2113 if (IS_ERR(key)) { 2114 err = PTR_ERR(key); 2115 goto err_put; 2116 } 2117 2118 value_size = bpf_map_value_size(map); 2119 2120 err = -ENOMEM; 2121 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2122 if (!value) 2123 goto free_key; 2124 2125 err = -ENOTSUPP; 2126 if (map->map_type == BPF_MAP_TYPE_QUEUE || 2127 map->map_type == BPF_MAP_TYPE_STACK) { 2128 err = map->ops->map_pop_elem(map, value); 2129 } else if (map->map_type == BPF_MAP_TYPE_HASH || 2130 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 2131 map->map_type == BPF_MAP_TYPE_LRU_HASH || 2132 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 2133 if (!bpf_map_is_offloaded(map)) { 2134 bpf_disable_instrumentation(); 2135 rcu_read_lock(); 2136 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 2137 rcu_read_unlock(); 2138 bpf_enable_instrumentation(); 2139 } 2140 } 2141 2142 if (err) 2143 goto free_value; 2144 2145 if (copy_to_user(uvalue, value, value_size) != 0) { 2146 err = -EFAULT; 2147 goto free_value; 2148 } 2149 2150 err = 0; 2151 2152 free_value: 2153 kvfree(value); 2154 free_key: 2155 kvfree(key); 2156 err_put: 2157 bpf_map_write_active_dec(map); 2158 return err; 2159 } 2160 2161 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2162 2163 static int map_freeze(const union bpf_attr *attr) 2164 { 2165 int err = 0; 2166 struct bpf_map *map; 2167 2168 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2169 return -EINVAL; 2170 2171 CLASS(fd, f)(attr->map_fd); 2172 map = __bpf_map_get(f); 2173 if (IS_ERR(map)) 2174 return PTR_ERR(map); 2175 2176 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) 2177 return -ENOTSUPP; 2178 2179 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) 2180 return -EPERM; 2181 2182 mutex_lock(&map->freeze_mutex); 2183 if (bpf_map_write_active(map)) { 2184 err = -EBUSY; 2185 goto err_put; 2186 } 2187 if (READ_ONCE(map->frozen)) { 2188 err = -EBUSY; 2189 goto err_put; 2190 } 2191 2192 WRITE_ONCE(map->frozen, true); 2193 err_put: 2194 mutex_unlock(&map->freeze_mutex); 2195 return err; 2196 } 2197 2198 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2199 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2200 [_id] = & _name ## _prog_ops, 2201 #define BPF_MAP_TYPE(_id, _ops) 2202 #define BPF_LINK_TYPE(_id, _name) 2203 #include <linux/bpf_types.h> 2204 #undef BPF_PROG_TYPE 2205 #undef BPF_MAP_TYPE 2206 #undef BPF_LINK_TYPE 2207 }; 2208 2209 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2210 { 2211 const struct bpf_prog_ops *ops; 2212 2213 if (type >= ARRAY_SIZE(bpf_prog_types)) 2214 return -EINVAL; 2215 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2216 ops = bpf_prog_types[type]; 2217 if (!ops) 2218 return -EINVAL; 2219 2220 if (!bpf_prog_is_offloaded(prog->aux)) 2221 prog->aux->ops = ops; 2222 else 2223 prog->aux->ops = &bpf_offload_prog_ops; 2224 prog->type = type; 2225 return 0; 2226 } 2227 2228 enum bpf_audit { 2229 BPF_AUDIT_LOAD, 2230 BPF_AUDIT_UNLOAD, 2231 BPF_AUDIT_MAX, 2232 }; 2233 2234 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2235 [BPF_AUDIT_LOAD] = "LOAD", 2236 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2237 }; 2238 2239 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2240 { 2241 struct audit_context *ctx = NULL; 2242 struct audit_buffer *ab; 2243 2244 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2245 return; 2246 if (audit_enabled == AUDIT_OFF) 2247 return; 2248 if (!in_irq() && !irqs_disabled()) 2249 ctx = audit_context(); 2250 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2251 if (unlikely(!ab)) 2252 return; 2253 audit_log_format(ab, "prog-id=%u op=%s", 2254 prog->aux->id, bpf_audit_str[op]); 2255 audit_log_end(ab); 2256 } 2257 2258 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2259 { 2260 int id; 2261 2262 idr_preload(GFP_KERNEL); 2263 spin_lock_bh(&prog_idr_lock); 2264 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2265 if (id > 0) 2266 prog->aux->id = id; 2267 spin_unlock_bh(&prog_idr_lock); 2268 idr_preload_end(); 2269 2270 /* id is in [1, INT_MAX) */ 2271 if (WARN_ON_ONCE(!id)) 2272 return -ENOSPC; 2273 2274 return id > 0 ? 0 : id; 2275 } 2276 2277 void bpf_prog_free_id(struct bpf_prog *prog) 2278 { 2279 unsigned long flags; 2280 2281 /* cBPF to eBPF migrations are currently not in the idr store. 2282 * Offloaded programs are removed from the store when their device 2283 * disappears - even if someone grabs an fd to them they are unusable, 2284 * simply waiting for refcnt to drop to be freed. 2285 */ 2286 if (!prog->aux->id) 2287 return; 2288 2289 spin_lock_irqsave(&prog_idr_lock, flags); 2290 idr_remove(&prog_idr, prog->aux->id); 2291 prog->aux->id = 0; 2292 spin_unlock_irqrestore(&prog_idr_lock, flags); 2293 } 2294 2295 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2296 { 2297 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2298 2299 kvfree(aux->func_info); 2300 kfree(aux->func_info_aux); 2301 free_uid(aux->user); 2302 security_bpf_prog_free(aux->prog); 2303 bpf_prog_free(aux->prog); 2304 } 2305 2306 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2307 { 2308 bpf_prog_kallsyms_del_all(prog); 2309 btf_put(prog->aux->btf); 2310 module_put(prog->aux->mod); 2311 kvfree(prog->aux->jited_linfo); 2312 kvfree(prog->aux->linfo); 2313 kfree(prog->aux->kfunc_tab); 2314 kfree(prog->aux->ctx_arg_info); 2315 if (prog->aux->attach_btf) 2316 btf_put(prog->aux->attach_btf); 2317 2318 if (deferred) { 2319 if (prog->sleepable) 2320 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2321 else 2322 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2323 } else { 2324 __bpf_prog_put_rcu(&prog->aux->rcu); 2325 } 2326 } 2327 2328 static void bpf_prog_put_deferred(struct work_struct *work) 2329 { 2330 struct bpf_prog_aux *aux; 2331 struct bpf_prog *prog; 2332 2333 aux = container_of(work, struct bpf_prog_aux, work); 2334 prog = aux->prog; 2335 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2336 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2337 bpf_prog_free_id(prog); 2338 __bpf_prog_put_noref(prog, true); 2339 } 2340 2341 static void __bpf_prog_put(struct bpf_prog *prog) 2342 { 2343 struct bpf_prog_aux *aux = prog->aux; 2344 2345 if (atomic64_dec_and_test(&aux->refcnt)) { 2346 if (in_irq() || irqs_disabled()) { 2347 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2348 schedule_work(&aux->work); 2349 } else { 2350 bpf_prog_put_deferred(&aux->work); 2351 } 2352 } 2353 } 2354 2355 void bpf_prog_put(struct bpf_prog *prog) 2356 { 2357 __bpf_prog_put(prog); 2358 } 2359 EXPORT_SYMBOL_GPL(bpf_prog_put); 2360 2361 static int bpf_prog_release(struct inode *inode, struct file *filp) 2362 { 2363 struct bpf_prog *prog = filp->private_data; 2364 2365 bpf_prog_put(prog); 2366 return 0; 2367 } 2368 2369 struct bpf_prog_kstats { 2370 u64 nsecs; 2371 u64 cnt; 2372 u64 misses; 2373 }; 2374 2375 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2376 { 2377 struct bpf_prog_stats *stats; 2378 unsigned int flags; 2379 2380 stats = this_cpu_ptr(prog->stats); 2381 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2382 u64_stats_inc(&stats->misses); 2383 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2384 } 2385 2386 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2387 struct bpf_prog_kstats *stats) 2388 { 2389 u64 nsecs = 0, cnt = 0, misses = 0; 2390 int cpu; 2391 2392 for_each_possible_cpu(cpu) { 2393 const struct bpf_prog_stats *st; 2394 unsigned int start; 2395 u64 tnsecs, tcnt, tmisses; 2396 2397 st = per_cpu_ptr(prog->stats, cpu); 2398 do { 2399 start = u64_stats_fetch_begin(&st->syncp); 2400 tnsecs = u64_stats_read(&st->nsecs); 2401 tcnt = u64_stats_read(&st->cnt); 2402 tmisses = u64_stats_read(&st->misses); 2403 } while (u64_stats_fetch_retry(&st->syncp, start)); 2404 nsecs += tnsecs; 2405 cnt += tcnt; 2406 misses += tmisses; 2407 } 2408 stats->nsecs = nsecs; 2409 stats->cnt = cnt; 2410 stats->misses = misses; 2411 } 2412 2413 #ifdef CONFIG_PROC_FS 2414 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2415 { 2416 const struct bpf_prog *prog = filp->private_data; 2417 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2418 struct bpf_prog_kstats stats; 2419 2420 bpf_prog_get_stats(prog, &stats); 2421 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2422 seq_printf(m, 2423 "prog_type:\t%u\n" 2424 "prog_jited:\t%u\n" 2425 "prog_tag:\t%s\n" 2426 "memlock:\t%llu\n" 2427 "prog_id:\t%u\n" 2428 "run_time_ns:\t%llu\n" 2429 "run_cnt:\t%llu\n" 2430 "recursion_misses:\t%llu\n" 2431 "verified_insns:\t%u\n", 2432 prog->type, 2433 prog->jited, 2434 prog_tag, 2435 prog->pages * 1ULL << PAGE_SHIFT, 2436 prog->aux->id, 2437 stats.nsecs, 2438 stats.cnt, 2439 stats.misses, 2440 prog->aux->verified_insns); 2441 } 2442 #endif 2443 2444 const struct file_operations bpf_prog_fops = { 2445 #ifdef CONFIG_PROC_FS 2446 .show_fdinfo = bpf_prog_show_fdinfo, 2447 #endif 2448 .release = bpf_prog_release, 2449 .read = bpf_dummy_read, 2450 .write = bpf_dummy_write, 2451 }; 2452 2453 int bpf_prog_new_fd(struct bpf_prog *prog) 2454 { 2455 int ret; 2456 2457 ret = security_bpf_prog(prog); 2458 if (ret < 0) 2459 return ret; 2460 2461 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2462 O_RDWR | O_CLOEXEC); 2463 } 2464 2465 void bpf_prog_add(struct bpf_prog *prog, int i) 2466 { 2467 atomic64_add(i, &prog->aux->refcnt); 2468 } 2469 EXPORT_SYMBOL_GPL(bpf_prog_add); 2470 2471 void bpf_prog_sub(struct bpf_prog *prog, int i) 2472 { 2473 /* Only to be used for undoing previous bpf_prog_add() in some 2474 * error path. We still know that another entity in our call 2475 * path holds a reference to the program, thus atomic_sub() can 2476 * be safely used in such cases! 2477 */ 2478 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2479 } 2480 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2481 2482 void bpf_prog_inc(struct bpf_prog *prog) 2483 { 2484 atomic64_inc(&prog->aux->refcnt); 2485 } 2486 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2487 2488 /* prog_idr_lock should have been held */ 2489 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2490 { 2491 int refold; 2492 2493 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2494 2495 if (!refold) 2496 return ERR_PTR(-ENOENT); 2497 2498 return prog; 2499 } 2500 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2501 2502 bool bpf_prog_get_ok(struct bpf_prog *prog, 2503 enum bpf_prog_type *attach_type, bool attach_drv) 2504 { 2505 /* not an attachment, just a refcount inc, always allow */ 2506 if (!attach_type) 2507 return true; 2508 2509 if (prog->type != *attach_type) 2510 return false; 2511 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2512 return false; 2513 2514 return true; 2515 } 2516 2517 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2518 bool attach_drv) 2519 { 2520 CLASS(fd, f)(ufd); 2521 struct bpf_prog *prog; 2522 2523 if (fd_empty(f)) 2524 return ERR_PTR(-EBADF); 2525 if (fd_file(f)->f_op != &bpf_prog_fops) 2526 return ERR_PTR(-EINVAL); 2527 2528 prog = fd_file(f)->private_data; 2529 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2530 return ERR_PTR(-EINVAL); 2531 2532 bpf_prog_inc(prog); 2533 return prog; 2534 } 2535 2536 struct bpf_prog *bpf_prog_get(u32 ufd) 2537 { 2538 return __bpf_prog_get(ufd, NULL, false); 2539 } 2540 2541 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2542 bool attach_drv) 2543 { 2544 return __bpf_prog_get(ufd, &type, attach_drv); 2545 } 2546 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2547 2548 /* Initially all BPF programs could be loaded w/o specifying 2549 * expected_attach_type. Later for some of them specifying expected_attach_type 2550 * at load time became required so that program could be validated properly. 2551 * Programs of types that are allowed to be loaded both w/ and w/o (for 2552 * backward compatibility) expected_attach_type, should have the default attach 2553 * type assigned to expected_attach_type for the latter case, so that it can be 2554 * validated later at attach time. 2555 * 2556 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2557 * prog type requires it but has some attach types that have to be backward 2558 * compatible. 2559 */ 2560 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2561 { 2562 switch (attr->prog_type) { 2563 case BPF_PROG_TYPE_CGROUP_SOCK: 2564 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2565 * exist so checking for non-zero is the way to go here. 2566 */ 2567 if (!attr->expected_attach_type) 2568 attr->expected_attach_type = 2569 BPF_CGROUP_INET_SOCK_CREATE; 2570 break; 2571 case BPF_PROG_TYPE_SK_REUSEPORT: 2572 if (!attr->expected_attach_type) 2573 attr->expected_attach_type = 2574 BPF_SK_REUSEPORT_SELECT; 2575 break; 2576 } 2577 } 2578 2579 static int 2580 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2581 enum bpf_attach_type expected_attach_type, 2582 struct btf *attach_btf, u32 btf_id, 2583 struct bpf_prog *dst_prog) 2584 { 2585 if (btf_id) { 2586 if (btf_id > BTF_MAX_TYPE) 2587 return -EINVAL; 2588 2589 if (!attach_btf && !dst_prog) 2590 return -EINVAL; 2591 2592 switch (prog_type) { 2593 case BPF_PROG_TYPE_TRACING: 2594 case BPF_PROG_TYPE_LSM: 2595 case BPF_PROG_TYPE_STRUCT_OPS: 2596 case BPF_PROG_TYPE_EXT: 2597 break; 2598 default: 2599 return -EINVAL; 2600 } 2601 } 2602 2603 if (attach_btf && (!btf_id || dst_prog)) 2604 return -EINVAL; 2605 2606 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2607 prog_type != BPF_PROG_TYPE_EXT) 2608 return -EINVAL; 2609 2610 switch (prog_type) { 2611 case BPF_PROG_TYPE_CGROUP_SOCK: 2612 switch (expected_attach_type) { 2613 case BPF_CGROUP_INET_SOCK_CREATE: 2614 case BPF_CGROUP_INET_SOCK_RELEASE: 2615 case BPF_CGROUP_INET4_POST_BIND: 2616 case BPF_CGROUP_INET6_POST_BIND: 2617 return 0; 2618 default: 2619 return -EINVAL; 2620 } 2621 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2622 switch (expected_attach_type) { 2623 case BPF_CGROUP_INET4_BIND: 2624 case BPF_CGROUP_INET6_BIND: 2625 case BPF_CGROUP_INET4_CONNECT: 2626 case BPF_CGROUP_INET6_CONNECT: 2627 case BPF_CGROUP_UNIX_CONNECT: 2628 case BPF_CGROUP_INET4_GETPEERNAME: 2629 case BPF_CGROUP_INET6_GETPEERNAME: 2630 case BPF_CGROUP_UNIX_GETPEERNAME: 2631 case BPF_CGROUP_INET4_GETSOCKNAME: 2632 case BPF_CGROUP_INET6_GETSOCKNAME: 2633 case BPF_CGROUP_UNIX_GETSOCKNAME: 2634 case BPF_CGROUP_UDP4_SENDMSG: 2635 case BPF_CGROUP_UDP6_SENDMSG: 2636 case BPF_CGROUP_UNIX_SENDMSG: 2637 case BPF_CGROUP_UDP4_RECVMSG: 2638 case BPF_CGROUP_UDP6_RECVMSG: 2639 case BPF_CGROUP_UNIX_RECVMSG: 2640 return 0; 2641 default: 2642 return -EINVAL; 2643 } 2644 case BPF_PROG_TYPE_CGROUP_SKB: 2645 switch (expected_attach_type) { 2646 case BPF_CGROUP_INET_INGRESS: 2647 case BPF_CGROUP_INET_EGRESS: 2648 return 0; 2649 default: 2650 return -EINVAL; 2651 } 2652 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2653 switch (expected_attach_type) { 2654 case BPF_CGROUP_SETSOCKOPT: 2655 case BPF_CGROUP_GETSOCKOPT: 2656 return 0; 2657 default: 2658 return -EINVAL; 2659 } 2660 case BPF_PROG_TYPE_SK_LOOKUP: 2661 if (expected_attach_type == BPF_SK_LOOKUP) 2662 return 0; 2663 return -EINVAL; 2664 case BPF_PROG_TYPE_SK_REUSEPORT: 2665 switch (expected_attach_type) { 2666 case BPF_SK_REUSEPORT_SELECT: 2667 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2668 return 0; 2669 default: 2670 return -EINVAL; 2671 } 2672 case BPF_PROG_TYPE_NETFILTER: 2673 if (expected_attach_type == BPF_NETFILTER) 2674 return 0; 2675 return -EINVAL; 2676 case BPF_PROG_TYPE_SYSCALL: 2677 case BPF_PROG_TYPE_EXT: 2678 if (expected_attach_type) 2679 return -EINVAL; 2680 fallthrough; 2681 default: 2682 return 0; 2683 } 2684 } 2685 2686 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2687 { 2688 switch (prog_type) { 2689 case BPF_PROG_TYPE_SCHED_CLS: 2690 case BPF_PROG_TYPE_SCHED_ACT: 2691 case BPF_PROG_TYPE_XDP: 2692 case BPF_PROG_TYPE_LWT_IN: 2693 case BPF_PROG_TYPE_LWT_OUT: 2694 case BPF_PROG_TYPE_LWT_XMIT: 2695 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2696 case BPF_PROG_TYPE_SK_SKB: 2697 case BPF_PROG_TYPE_SK_MSG: 2698 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2699 case BPF_PROG_TYPE_CGROUP_DEVICE: 2700 case BPF_PROG_TYPE_CGROUP_SOCK: 2701 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2702 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2703 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2704 case BPF_PROG_TYPE_SOCK_OPS: 2705 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2706 case BPF_PROG_TYPE_NETFILTER: 2707 return true; 2708 case BPF_PROG_TYPE_CGROUP_SKB: 2709 /* always unpriv */ 2710 case BPF_PROG_TYPE_SK_REUSEPORT: 2711 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2712 default: 2713 return false; 2714 } 2715 } 2716 2717 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2718 { 2719 switch (prog_type) { 2720 case BPF_PROG_TYPE_KPROBE: 2721 case BPF_PROG_TYPE_TRACEPOINT: 2722 case BPF_PROG_TYPE_PERF_EVENT: 2723 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2724 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2725 case BPF_PROG_TYPE_TRACING: 2726 case BPF_PROG_TYPE_LSM: 2727 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2728 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2729 return true; 2730 default: 2731 return false; 2732 } 2733 } 2734 2735 /* last field in 'union bpf_attr' used by this command */ 2736 #define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt 2737 2738 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) 2739 { 2740 enum bpf_prog_type type = attr->prog_type; 2741 struct bpf_prog *prog, *dst_prog = NULL; 2742 struct btf *attach_btf = NULL; 2743 struct bpf_token *token = NULL; 2744 bool bpf_cap; 2745 int err; 2746 char license[128]; 2747 2748 if (CHECK_ATTR(BPF_PROG_LOAD)) 2749 return -EINVAL; 2750 2751 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2752 BPF_F_ANY_ALIGNMENT | 2753 BPF_F_TEST_STATE_FREQ | 2754 BPF_F_SLEEPABLE | 2755 BPF_F_TEST_RND_HI32 | 2756 BPF_F_XDP_HAS_FRAGS | 2757 BPF_F_XDP_DEV_BOUND_ONLY | 2758 BPF_F_TEST_REG_INVARIANTS | 2759 BPF_F_TOKEN_FD)) 2760 return -EINVAL; 2761 2762 bpf_prog_load_fixup_attach_type(attr); 2763 2764 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2765 token = bpf_token_get_from_fd(attr->prog_token_fd); 2766 if (IS_ERR(token)) 2767 return PTR_ERR(token); 2768 /* if current token doesn't grant prog loading permissions, 2769 * then we can't use this token, so ignore it and rely on 2770 * system-wide capabilities checks 2771 */ 2772 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2773 !bpf_token_allow_prog_type(token, attr->prog_type, 2774 attr->expected_attach_type)) { 2775 bpf_token_put(token); 2776 token = NULL; 2777 } 2778 } 2779 2780 bpf_cap = bpf_token_capable(token, CAP_BPF); 2781 err = -EPERM; 2782 2783 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2784 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2785 !bpf_cap) 2786 goto put_token; 2787 2788 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2789 * creation for unprivileged users; other actions depend 2790 * on fd availability and access to bpffs, so are dependent on 2791 * object creation success. Even with unprivileged BPF disabled, 2792 * capability checks are still carried out for these 2793 * and other operations. 2794 */ 2795 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 2796 goto put_token; 2797 2798 if (attr->insn_cnt == 0 || 2799 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 2800 err = -E2BIG; 2801 goto put_token; 2802 } 2803 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2804 type != BPF_PROG_TYPE_CGROUP_SKB && 2805 !bpf_cap) 2806 goto put_token; 2807 2808 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 2809 goto put_token; 2810 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 2811 goto put_token; 2812 2813 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 2814 * or btf, we need to check which one it is 2815 */ 2816 if (attr->attach_prog_fd) { 2817 dst_prog = bpf_prog_get(attr->attach_prog_fd); 2818 if (IS_ERR(dst_prog)) { 2819 dst_prog = NULL; 2820 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 2821 if (IS_ERR(attach_btf)) { 2822 err = -EINVAL; 2823 goto put_token; 2824 } 2825 if (!btf_is_kernel(attach_btf)) { 2826 /* attaching through specifying bpf_prog's BTF 2827 * objects directly might be supported eventually 2828 */ 2829 btf_put(attach_btf); 2830 err = -ENOTSUPP; 2831 goto put_token; 2832 } 2833 } 2834 } else if (attr->attach_btf_id) { 2835 /* fall back to vmlinux BTF, if BTF type ID is specified */ 2836 attach_btf = bpf_get_btf_vmlinux(); 2837 if (IS_ERR(attach_btf)) { 2838 err = PTR_ERR(attach_btf); 2839 goto put_token; 2840 } 2841 if (!attach_btf) { 2842 err = -EINVAL; 2843 goto put_token; 2844 } 2845 btf_get(attach_btf); 2846 } 2847 2848 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 2849 attach_btf, attr->attach_btf_id, 2850 dst_prog)) { 2851 if (dst_prog) 2852 bpf_prog_put(dst_prog); 2853 if (attach_btf) 2854 btf_put(attach_btf); 2855 err = -EINVAL; 2856 goto put_token; 2857 } 2858 2859 /* plain bpf_prog allocation */ 2860 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 2861 if (!prog) { 2862 if (dst_prog) 2863 bpf_prog_put(dst_prog); 2864 if (attach_btf) 2865 btf_put(attach_btf); 2866 err = -EINVAL; 2867 goto put_token; 2868 } 2869 2870 prog->expected_attach_type = attr->expected_attach_type; 2871 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 2872 prog->aux->attach_btf = attach_btf; 2873 prog->aux->attach_btf_id = attr->attach_btf_id; 2874 prog->aux->dst_prog = dst_prog; 2875 prog->aux->dev_bound = !!attr->prog_ifindex; 2876 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 2877 2878 /* move token into prog->aux, reuse taken refcnt */ 2879 prog->aux->token = token; 2880 token = NULL; 2881 2882 prog->aux->user = get_current_user(); 2883 prog->len = attr->insn_cnt; 2884 2885 err = -EFAULT; 2886 if (copy_from_bpfptr(prog->insns, 2887 make_bpfptr(attr->insns, uattr.is_kernel), 2888 bpf_prog_insn_size(prog)) != 0) 2889 goto free_prog; 2890 /* copy eBPF program license from user space */ 2891 if (strncpy_from_bpfptr(license, 2892 make_bpfptr(attr->license, uattr.is_kernel), 2893 sizeof(license) - 1) < 0) 2894 goto free_prog; 2895 license[sizeof(license) - 1] = 0; 2896 2897 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 2898 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 2899 2900 prog->orig_prog = NULL; 2901 prog->jited = 0; 2902 2903 atomic64_set(&prog->aux->refcnt, 1); 2904 2905 if (bpf_prog_is_dev_bound(prog->aux)) { 2906 err = bpf_prog_dev_bound_init(prog, attr); 2907 if (err) 2908 goto free_prog; 2909 } 2910 2911 if (type == BPF_PROG_TYPE_EXT && dst_prog && 2912 bpf_prog_is_dev_bound(dst_prog->aux)) { 2913 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 2914 if (err) 2915 goto free_prog; 2916 } 2917 2918 /* 2919 * Bookkeeping for managing the program attachment chain. 2920 * 2921 * It might be tempting to set attach_tracing_prog flag at the attachment 2922 * time, but this will not prevent from loading bunch of tracing prog 2923 * first, then attach them one to another. 2924 * 2925 * The flag attach_tracing_prog is set for the whole program lifecycle, and 2926 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 2927 * programs cannot change attachment target. 2928 */ 2929 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 2930 dst_prog->type == BPF_PROG_TYPE_TRACING) { 2931 prog->aux->attach_tracing_prog = true; 2932 } 2933 2934 /* find program type: socket_filter vs tracing_filter */ 2935 err = find_prog_type(type, prog); 2936 if (err < 0) 2937 goto free_prog; 2938 2939 prog->aux->load_time = ktime_get_boottime_ns(); 2940 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 2941 sizeof(attr->prog_name)); 2942 if (err < 0) 2943 goto free_prog; 2944 2945 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel); 2946 if (err) 2947 goto free_prog_sec; 2948 2949 /* run eBPF verifier */ 2950 err = bpf_check(&prog, attr, uattr, uattr_size); 2951 if (err < 0) 2952 goto free_used_maps; 2953 2954 prog = bpf_prog_select_runtime(prog, &err); 2955 if (err < 0) 2956 goto free_used_maps; 2957 2958 err = bpf_prog_alloc_id(prog); 2959 if (err) 2960 goto free_used_maps; 2961 2962 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 2963 * effectively publicly exposed. However, retrieving via 2964 * bpf_prog_get_fd_by_id() will take another reference, 2965 * therefore it cannot be gone underneath us. 2966 * 2967 * Only for the time /after/ successful bpf_prog_new_fd() 2968 * and before returning to userspace, we might just hold 2969 * one reference and any parallel close on that fd could 2970 * rip everything out. Hence, below notifications must 2971 * happen before bpf_prog_new_fd(). 2972 * 2973 * Also, any failure handling from this point onwards must 2974 * be using bpf_prog_put() given the program is exposed. 2975 */ 2976 bpf_prog_kallsyms_add(prog); 2977 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 2978 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 2979 2980 err = bpf_prog_new_fd(prog); 2981 if (err < 0) 2982 bpf_prog_put(prog); 2983 return err; 2984 2985 free_used_maps: 2986 /* In case we have subprogs, we need to wait for a grace 2987 * period before we can tear down JIT memory since symbols 2988 * are already exposed under kallsyms. 2989 */ 2990 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 2991 return err; 2992 2993 free_prog_sec: 2994 security_bpf_prog_free(prog); 2995 free_prog: 2996 free_uid(prog->aux->user); 2997 if (prog->aux->attach_btf) 2998 btf_put(prog->aux->attach_btf); 2999 bpf_prog_free(prog); 3000 put_token: 3001 bpf_token_put(token); 3002 return err; 3003 } 3004 3005 #define BPF_OBJ_LAST_FIELD path_fd 3006 3007 static int bpf_obj_pin(const union bpf_attr *attr) 3008 { 3009 int path_fd; 3010 3011 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3012 return -EINVAL; 3013 3014 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3015 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3016 return -EINVAL; 3017 3018 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3019 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3020 u64_to_user_ptr(attr->pathname)); 3021 } 3022 3023 static int bpf_obj_get(const union bpf_attr *attr) 3024 { 3025 int path_fd; 3026 3027 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3028 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3029 return -EINVAL; 3030 3031 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3032 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3033 return -EINVAL; 3034 3035 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3036 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3037 attr->file_flags); 3038 } 3039 3040 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3041 * "sleepable" semantics, which normally would mean that BPF link's attach 3042 * hook can dereference link or link's underlying program for some time after 3043 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3044 * BPF program itself can be non-sleepable, yet, because it's transitively 3045 * reachable through BPF link, its freeing has to be delayed until after RCU 3046 * Tasks Trace GP. 3047 */ 3048 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3049 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3050 bool sleepable) 3051 { 3052 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3053 atomic64_set(&link->refcnt, 1); 3054 link->type = type; 3055 link->sleepable = sleepable; 3056 link->id = 0; 3057 link->ops = ops; 3058 link->prog = prog; 3059 } 3060 3061 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3062 const struct bpf_link_ops *ops, struct bpf_prog *prog) 3063 { 3064 bpf_link_init_sleepable(link, type, ops, prog, false); 3065 } 3066 3067 static void bpf_link_free_id(int id) 3068 { 3069 if (!id) 3070 return; 3071 3072 spin_lock_bh(&link_idr_lock); 3073 idr_remove(&link_idr, id); 3074 spin_unlock_bh(&link_idr_lock); 3075 } 3076 3077 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3078 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3079 * anon_inode's release() call. This helper marks bpf_link as 3080 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3081 * is not decremented, it's the responsibility of a calling code that failed 3082 * to complete bpf_link initialization. 3083 * This helper eventually calls link's dealloc callback, but does not call 3084 * link's release callback. 3085 */ 3086 void bpf_link_cleanup(struct bpf_link_primer *primer) 3087 { 3088 primer->link->prog = NULL; 3089 bpf_link_free_id(primer->id); 3090 fput(primer->file); 3091 put_unused_fd(primer->fd); 3092 } 3093 3094 void bpf_link_inc(struct bpf_link *link) 3095 { 3096 atomic64_inc(&link->refcnt); 3097 } 3098 3099 static void bpf_link_dealloc(struct bpf_link *link) 3100 { 3101 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3102 if (link->prog) 3103 bpf_prog_put(link->prog); 3104 3105 /* free bpf_link and its containing memory */ 3106 if (link->ops->dealloc_deferred) 3107 link->ops->dealloc_deferred(link); 3108 else 3109 link->ops->dealloc(link); 3110 } 3111 3112 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3113 { 3114 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3115 3116 bpf_link_dealloc(link); 3117 } 3118 3119 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu) 3120 { 3121 if (rcu_trace_implies_rcu_gp()) 3122 bpf_link_defer_dealloc_rcu_gp(rcu); 3123 else 3124 call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp); 3125 } 3126 3127 /* bpf_link_free is guaranteed to be called from process context */ 3128 static void bpf_link_free(struct bpf_link *link) 3129 { 3130 const struct bpf_link_ops *ops = link->ops; 3131 3132 bpf_link_free_id(link->id); 3133 /* detach BPF program, clean up used resources */ 3134 if (link->prog) 3135 ops->release(link); 3136 if (ops->dealloc_deferred) { 3137 /* Schedule BPF link deallocation, which will only then 3138 * trigger putting BPF program refcount. 3139 * If underlying BPF program is sleepable or BPF link's target 3140 * attach hookpoint is sleepable or otherwise requires RCU GPs 3141 * to ensure link and its underlying BPF program is not 3142 * reachable anymore, we need to first wait for RCU tasks 3143 * trace sync, and then go through "classic" RCU grace period 3144 */ 3145 if (link->sleepable || (link->prog && link->prog->sleepable)) 3146 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp); 3147 else 3148 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3149 } else if (ops->dealloc) { 3150 bpf_link_dealloc(link); 3151 } 3152 } 3153 3154 static void bpf_link_put_deferred(struct work_struct *work) 3155 { 3156 struct bpf_link *link = container_of(work, struct bpf_link, work); 3157 3158 bpf_link_free(link); 3159 } 3160 3161 /* bpf_link_put might be called from atomic context. It needs to be called 3162 * from sleepable context in order to acquire sleeping locks during the process. 3163 */ 3164 void bpf_link_put(struct bpf_link *link) 3165 { 3166 if (!atomic64_dec_and_test(&link->refcnt)) 3167 return; 3168 3169 INIT_WORK(&link->work, bpf_link_put_deferred); 3170 schedule_work(&link->work); 3171 } 3172 EXPORT_SYMBOL(bpf_link_put); 3173 3174 static void bpf_link_put_direct(struct bpf_link *link) 3175 { 3176 if (!atomic64_dec_and_test(&link->refcnt)) 3177 return; 3178 bpf_link_free(link); 3179 } 3180 3181 static int bpf_link_release(struct inode *inode, struct file *filp) 3182 { 3183 struct bpf_link *link = filp->private_data; 3184 3185 bpf_link_put_direct(link); 3186 return 0; 3187 } 3188 3189 #ifdef CONFIG_PROC_FS 3190 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3191 #define BPF_MAP_TYPE(_id, _ops) 3192 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3193 static const char *bpf_link_type_strs[] = { 3194 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3195 #include <linux/bpf_types.h> 3196 }; 3197 #undef BPF_PROG_TYPE 3198 #undef BPF_MAP_TYPE 3199 #undef BPF_LINK_TYPE 3200 3201 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3202 { 3203 const struct bpf_link *link = filp->private_data; 3204 const struct bpf_prog *prog = link->prog; 3205 enum bpf_link_type type = link->type; 3206 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3207 3208 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3209 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3210 } else { 3211 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3212 seq_printf(m, "link_type:\t<%u>\n", type); 3213 } 3214 seq_printf(m, "link_id:\t%u\n", link->id); 3215 3216 if (prog) { 3217 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3218 seq_printf(m, 3219 "prog_tag:\t%s\n" 3220 "prog_id:\t%u\n", 3221 prog_tag, 3222 prog->aux->id); 3223 } 3224 if (link->ops->show_fdinfo) 3225 link->ops->show_fdinfo(link, m); 3226 } 3227 #endif 3228 3229 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3230 { 3231 struct bpf_link *link = file->private_data; 3232 3233 return link->ops->poll(file, pts); 3234 } 3235 3236 static const struct file_operations bpf_link_fops = { 3237 #ifdef CONFIG_PROC_FS 3238 .show_fdinfo = bpf_link_show_fdinfo, 3239 #endif 3240 .release = bpf_link_release, 3241 .read = bpf_dummy_read, 3242 .write = bpf_dummy_write, 3243 }; 3244 3245 static const struct file_operations bpf_link_fops_poll = { 3246 #ifdef CONFIG_PROC_FS 3247 .show_fdinfo = bpf_link_show_fdinfo, 3248 #endif 3249 .release = bpf_link_release, 3250 .read = bpf_dummy_read, 3251 .write = bpf_dummy_write, 3252 .poll = bpf_link_poll, 3253 }; 3254 3255 static int bpf_link_alloc_id(struct bpf_link *link) 3256 { 3257 int id; 3258 3259 idr_preload(GFP_KERNEL); 3260 spin_lock_bh(&link_idr_lock); 3261 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3262 spin_unlock_bh(&link_idr_lock); 3263 idr_preload_end(); 3264 3265 return id; 3266 } 3267 3268 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3269 * reserving unused FD and allocating ID from link_idr. This is to be paired 3270 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3271 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3272 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3273 * transient state is passed around in struct bpf_link_primer. 3274 * This is preferred way to create and initialize bpf_link, especially when 3275 * there are complicated and expensive operations in between creating bpf_link 3276 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3277 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3278 * expensive (and potentially failing) roll back operations in a rare case 3279 * that file, FD, or ID can't be allocated. 3280 */ 3281 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3282 { 3283 struct file *file; 3284 int fd, id; 3285 3286 fd = get_unused_fd_flags(O_CLOEXEC); 3287 if (fd < 0) 3288 return fd; 3289 3290 3291 id = bpf_link_alloc_id(link); 3292 if (id < 0) { 3293 put_unused_fd(fd); 3294 return id; 3295 } 3296 3297 file = anon_inode_getfile("bpf_link", 3298 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3299 link, O_CLOEXEC); 3300 if (IS_ERR(file)) { 3301 bpf_link_free_id(id); 3302 put_unused_fd(fd); 3303 return PTR_ERR(file); 3304 } 3305 3306 primer->link = link; 3307 primer->file = file; 3308 primer->fd = fd; 3309 primer->id = id; 3310 return 0; 3311 } 3312 3313 int bpf_link_settle(struct bpf_link_primer *primer) 3314 { 3315 /* make bpf_link fetchable by ID */ 3316 spin_lock_bh(&link_idr_lock); 3317 primer->link->id = primer->id; 3318 spin_unlock_bh(&link_idr_lock); 3319 /* make bpf_link fetchable by FD */ 3320 fd_install(primer->fd, primer->file); 3321 /* pass through installed FD */ 3322 return primer->fd; 3323 } 3324 3325 int bpf_link_new_fd(struct bpf_link *link) 3326 { 3327 return anon_inode_getfd("bpf-link", 3328 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3329 link, O_CLOEXEC); 3330 } 3331 3332 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3333 { 3334 CLASS(fd, f)(ufd); 3335 struct bpf_link *link; 3336 3337 if (fd_empty(f)) 3338 return ERR_PTR(-EBADF); 3339 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3340 return ERR_PTR(-EINVAL); 3341 3342 link = fd_file(f)->private_data; 3343 bpf_link_inc(link); 3344 return link; 3345 } 3346 EXPORT_SYMBOL(bpf_link_get_from_fd); 3347 3348 static void bpf_tracing_link_release(struct bpf_link *link) 3349 { 3350 struct bpf_tracing_link *tr_link = 3351 container_of(link, struct bpf_tracing_link, link.link); 3352 3353 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3354 tr_link->trampoline, 3355 tr_link->tgt_prog)); 3356 3357 bpf_trampoline_put(tr_link->trampoline); 3358 3359 /* tgt_prog is NULL if target is a kernel function */ 3360 if (tr_link->tgt_prog) 3361 bpf_prog_put(tr_link->tgt_prog); 3362 } 3363 3364 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3365 { 3366 struct bpf_tracing_link *tr_link = 3367 container_of(link, struct bpf_tracing_link, link.link); 3368 3369 kfree(tr_link); 3370 } 3371 3372 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3373 struct seq_file *seq) 3374 { 3375 struct bpf_tracing_link *tr_link = 3376 container_of(link, struct bpf_tracing_link, link.link); 3377 u32 target_btf_id, target_obj_id; 3378 3379 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3380 &target_obj_id, &target_btf_id); 3381 seq_printf(seq, 3382 "attach_type:\t%d\n" 3383 "target_obj_id:\t%u\n" 3384 "target_btf_id:\t%u\n", 3385 tr_link->attach_type, 3386 target_obj_id, 3387 target_btf_id); 3388 } 3389 3390 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3391 struct bpf_link_info *info) 3392 { 3393 struct bpf_tracing_link *tr_link = 3394 container_of(link, struct bpf_tracing_link, link.link); 3395 3396 info->tracing.attach_type = tr_link->attach_type; 3397 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3398 &info->tracing.target_obj_id, 3399 &info->tracing.target_btf_id); 3400 3401 return 0; 3402 } 3403 3404 static const struct bpf_link_ops bpf_tracing_link_lops = { 3405 .release = bpf_tracing_link_release, 3406 .dealloc = bpf_tracing_link_dealloc, 3407 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3408 .fill_link_info = bpf_tracing_link_fill_link_info, 3409 }; 3410 3411 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3412 int tgt_prog_fd, 3413 u32 btf_id, 3414 u64 bpf_cookie) 3415 { 3416 struct bpf_link_primer link_primer; 3417 struct bpf_prog *tgt_prog = NULL; 3418 struct bpf_trampoline *tr = NULL; 3419 struct bpf_tracing_link *link; 3420 u64 key = 0; 3421 int err; 3422 3423 switch (prog->type) { 3424 case BPF_PROG_TYPE_TRACING: 3425 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3426 prog->expected_attach_type != BPF_TRACE_FEXIT && 3427 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3428 err = -EINVAL; 3429 goto out_put_prog; 3430 } 3431 break; 3432 case BPF_PROG_TYPE_EXT: 3433 if (prog->expected_attach_type != 0) { 3434 err = -EINVAL; 3435 goto out_put_prog; 3436 } 3437 break; 3438 case BPF_PROG_TYPE_LSM: 3439 if (prog->expected_attach_type != BPF_LSM_MAC) { 3440 err = -EINVAL; 3441 goto out_put_prog; 3442 } 3443 break; 3444 default: 3445 err = -EINVAL; 3446 goto out_put_prog; 3447 } 3448 3449 if (!!tgt_prog_fd != !!btf_id) { 3450 err = -EINVAL; 3451 goto out_put_prog; 3452 } 3453 3454 if (tgt_prog_fd) { 3455 /* 3456 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3457 * part would be changed to implement the same for 3458 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3459 * attach_tracing_prog flag is set. 3460 */ 3461 if (prog->type != BPF_PROG_TYPE_EXT) { 3462 err = -EINVAL; 3463 goto out_put_prog; 3464 } 3465 3466 tgt_prog = bpf_prog_get(tgt_prog_fd); 3467 if (IS_ERR(tgt_prog)) { 3468 err = PTR_ERR(tgt_prog); 3469 tgt_prog = NULL; 3470 goto out_put_prog; 3471 } 3472 3473 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3474 } 3475 3476 link = kzalloc(sizeof(*link), GFP_USER); 3477 if (!link) { 3478 err = -ENOMEM; 3479 goto out_put_prog; 3480 } 3481 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3482 &bpf_tracing_link_lops, prog); 3483 link->attach_type = prog->expected_attach_type; 3484 link->link.cookie = bpf_cookie; 3485 3486 mutex_lock(&prog->aux->dst_mutex); 3487 3488 /* There are a few possible cases here: 3489 * 3490 * - if prog->aux->dst_trampoline is set, the program was just loaded 3491 * and not yet attached to anything, so we can use the values stored 3492 * in prog->aux 3493 * 3494 * - if prog->aux->dst_trampoline is NULL, the program has already been 3495 * attached to a target and its initial target was cleared (below) 3496 * 3497 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3498 * target_btf_id using the link_create API. 3499 * 3500 * - if tgt_prog == NULL when this function was called using the old 3501 * raw_tracepoint_open API, and we need a target from prog->aux 3502 * 3503 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3504 * was detached and is going for re-attachment. 3505 * 3506 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3507 * are NULL, then program was already attached and user did not provide 3508 * tgt_prog_fd so we have no way to find out or create trampoline 3509 */ 3510 if (!prog->aux->dst_trampoline && !tgt_prog) { 3511 /* 3512 * Allow re-attach for TRACING and LSM programs. If it's 3513 * currently linked, bpf_trampoline_link_prog will fail. 3514 * EXT programs need to specify tgt_prog_fd, so they 3515 * re-attach in separate code path. 3516 */ 3517 if (prog->type != BPF_PROG_TYPE_TRACING && 3518 prog->type != BPF_PROG_TYPE_LSM) { 3519 err = -EINVAL; 3520 goto out_unlock; 3521 } 3522 /* We can allow re-attach only if we have valid attach_btf. */ 3523 if (!prog->aux->attach_btf) { 3524 err = -EINVAL; 3525 goto out_unlock; 3526 } 3527 btf_id = prog->aux->attach_btf_id; 3528 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3529 } 3530 3531 if (!prog->aux->dst_trampoline || 3532 (key && key != prog->aux->dst_trampoline->key)) { 3533 /* If there is no saved target, or the specified target is 3534 * different from the destination specified at load time, we 3535 * need a new trampoline and a check for compatibility 3536 */ 3537 struct bpf_attach_target_info tgt_info = {}; 3538 3539 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3540 &tgt_info); 3541 if (err) 3542 goto out_unlock; 3543 3544 if (tgt_info.tgt_mod) { 3545 module_put(prog->aux->mod); 3546 prog->aux->mod = tgt_info.tgt_mod; 3547 } 3548 3549 tr = bpf_trampoline_get(key, &tgt_info); 3550 if (!tr) { 3551 err = -ENOMEM; 3552 goto out_unlock; 3553 } 3554 } else { 3555 /* The caller didn't specify a target, or the target was the 3556 * same as the destination supplied during program load. This 3557 * means we can reuse the trampoline and reference from program 3558 * load time, and there is no need to allocate a new one. This 3559 * can only happen once for any program, as the saved values in 3560 * prog->aux are cleared below. 3561 */ 3562 tr = prog->aux->dst_trampoline; 3563 tgt_prog = prog->aux->dst_prog; 3564 } 3565 3566 err = bpf_link_prime(&link->link.link, &link_primer); 3567 if (err) 3568 goto out_unlock; 3569 3570 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog); 3571 if (err) { 3572 bpf_link_cleanup(&link_primer); 3573 link = NULL; 3574 goto out_unlock; 3575 } 3576 3577 link->tgt_prog = tgt_prog; 3578 link->trampoline = tr; 3579 3580 /* Always clear the trampoline and target prog from prog->aux to make 3581 * sure the original attach destination is not kept alive after a 3582 * program is (re-)attached to another target. 3583 */ 3584 if (prog->aux->dst_prog && 3585 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3586 /* got extra prog ref from syscall, or attaching to different prog */ 3587 bpf_prog_put(prog->aux->dst_prog); 3588 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3589 /* we allocated a new trampoline, so free the old one */ 3590 bpf_trampoline_put(prog->aux->dst_trampoline); 3591 3592 prog->aux->dst_prog = NULL; 3593 prog->aux->dst_trampoline = NULL; 3594 mutex_unlock(&prog->aux->dst_mutex); 3595 3596 return bpf_link_settle(&link_primer); 3597 out_unlock: 3598 if (tr && tr != prog->aux->dst_trampoline) 3599 bpf_trampoline_put(tr); 3600 mutex_unlock(&prog->aux->dst_mutex); 3601 kfree(link); 3602 out_put_prog: 3603 if (tgt_prog_fd && tgt_prog) 3604 bpf_prog_put(tgt_prog); 3605 return err; 3606 } 3607 3608 static void bpf_raw_tp_link_release(struct bpf_link *link) 3609 { 3610 struct bpf_raw_tp_link *raw_tp = 3611 container_of(link, struct bpf_raw_tp_link, link); 3612 3613 bpf_probe_unregister(raw_tp->btp, raw_tp); 3614 bpf_put_raw_tracepoint(raw_tp->btp); 3615 } 3616 3617 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3618 { 3619 struct bpf_raw_tp_link *raw_tp = 3620 container_of(link, struct bpf_raw_tp_link, link); 3621 3622 kfree(raw_tp); 3623 } 3624 3625 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3626 struct seq_file *seq) 3627 { 3628 struct bpf_raw_tp_link *raw_tp_link = 3629 container_of(link, struct bpf_raw_tp_link, link); 3630 3631 seq_printf(seq, 3632 "tp_name:\t%s\n", 3633 raw_tp_link->btp->tp->name); 3634 } 3635 3636 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3637 u32 len) 3638 { 3639 if (ulen >= len + 1) { 3640 if (copy_to_user(ubuf, buf, len + 1)) 3641 return -EFAULT; 3642 } else { 3643 char zero = '\0'; 3644 3645 if (copy_to_user(ubuf, buf, ulen - 1)) 3646 return -EFAULT; 3647 if (put_user(zero, ubuf + ulen - 1)) 3648 return -EFAULT; 3649 return -ENOSPC; 3650 } 3651 3652 return 0; 3653 } 3654 3655 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3656 struct bpf_link_info *info) 3657 { 3658 struct bpf_raw_tp_link *raw_tp_link = 3659 container_of(link, struct bpf_raw_tp_link, link); 3660 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3661 const char *tp_name = raw_tp_link->btp->tp->name; 3662 u32 ulen = info->raw_tracepoint.tp_name_len; 3663 size_t tp_len = strlen(tp_name); 3664 3665 if (!ulen ^ !ubuf) 3666 return -EINVAL; 3667 3668 info->raw_tracepoint.tp_name_len = tp_len + 1; 3669 3670 if (!ubuf) 3671 return 0; 3672 3673 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3674 } 3675 3676 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3677 .release = bpf_raw_tp_link_release, 3678 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3679 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3680 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3681 }; 3682 3683 #ifdef CONFIG_PERF_EVENTS 3684 struct bpf_perf_link { 3685 struct bpf_link link; 3686 struct file *perf_file; 3687 }; 3688 3689 static void bpf_perf_link_release(struct bpf_link *link) 3690 { 3691 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3692 struct perf_event *event = perf_link->perf_file->private_data; 3693 3694 perf_event_free_bpf_prog(event); 3695 fput(perf_link->perf_file); 3696 } 3697 3698 static void bpf_perf_link_dealloc(struct bpf_link *link) 3699 { 3700 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3701 3702 kfree(perf_link); 3703 } 3704 3705 static int bpf_perf_link_fill_common(const struct perf_event *event, 3706 char __user *uname, u32 *ulenp, 3707 u64 *probe_offset, u64 *probe_addr, 3708 u32 *fd_type, unsigned long *missed) 3709 { 3710 const char *buf; 3711 u32 prog_id, ulen; 3712 size_t len; 3713 int err; 3714 3715 ulen = *ulenp; 3716 if (!ulen ^ !uname) 3717 return -EINVAL; 3718 3719 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3720 probe_offset, probe_addr, missed); 3721 if (err) 3722 return err; 3723 3724 if (buf) { 3725 len = strlen(buf); 3726 *ulenp = len + 1; 3727 } else { 3728 *ulenp = 1; 3729 } 3730 if (!uname) 3731 return 0; 3732 3733 if (buf) { 3734 err = bpf_copy_to_user(uname, buf, ulen, len); 3735 if (err) 3736 return err; 3737 } else { 3738 char zero = '\0'; 3739 3740 if (put_user(zero, uname)) 3741 return -EFAULT; 3742 } 3743 return 0; 3744 } 3745 3746 #ifdef CONFIG_KPROBE_EVENTS 3747 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 3748 struct bpf_link_info *info) 3749 { 3750 unsigned long missed; 3751 char __user *uname; 3752 u64 addr, offset; 3753 u32 ulen, type; 3754 int err; 3755 3756 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 3757 ulen = info->perf_event.kprobe.name_len; 3758 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 3759 &type, &missed); 3760 if (err) 3761 return err; 3762 if (type == BPF_FD_TYPE_KRETPROBE) 3763 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 3764 else 3765 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 3766 info->perf_event.kprobe.name_len = ulen; 3767 info->perf_event.kprobe.offset = offset; 3768 info->perf_event.kprobe.missed = missed; 3769 if (!kallsyms_show_value(current_cred())) 3770 addr = 0; 3771 info->perf_event.kprobe.addr = addr; 3772 info->perf_event.kprobe.cookie = event->bpf_cookie; 3773 return 0; 3774 } 3775 #endif 3776 3777 #ifdef CONFIG_UPROBE_EVENTS 3778 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 3779 struct bpf_link_info *info) 3780 { 3781 char __user *uname; 3782 u64 addr, offset; 3783 u32 ulen, type; 3784 int err; 3785 3786 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 3787 ulen = info->perf_event.uprobe.name_len; 3788 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 3789 &type, NULL); 3790 if (err) 3791 return err; 3792 3793 if (type == BPF_FD_TYPE_URETPROBE) 3794 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 3795 else 3796 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 3797 info->perf_event.uprobe.name_len = ulen; 3798 info->perf_event.uprobe.offset = offset; 3799 info->perf_event.uprobe.cookie = event->bpf_cookie; 3800 return 0; 3801 } 3802 #endif 3803 3804 static int bpf_perf_link_fill_probe(const struct perf_event *event, 3805 struct bpf_link_info *info) 3806 { 3807 #ifdef CONFIG_KPROBE_EVENTS 3808 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 3809 return bpf_perf_link_fill_kprobe(event, info); 3810 #endif 3811 #ifdef CONFIG_UPROBE_EVENTS 3812 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 3813 return bpf_perf_link_fill_uprobe(event, info); 3814 #endif 3815 return -EOPNOTSUPP; 3816 } 3817 3818 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 3819 struct bpf_link_info *info) 3820 { 3821 char __user *uname; 3822 u32 ulen; 3823 int err; 3824 3825 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 3826 ulen = info->perf_event.tracepoint.name_len; 3827 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 3828 if (err) 3829 return err; 3830 3831 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 3832 info->perf_event.tracepoint.name_len = ulen; 3833 info->perf_event.tracepoint.cookie = event->bpf_cookie; 3834 return 0; 3835 } 3836 3837 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 3838 struct bpf_link_info *info) 3839 { 3840 info->perf_event.event.type = event->attr.type; 3841 info->perf_event.event.config = event->attr.config; 3842 info->perf_event.event.cookie = event->bpf_cookie; 3843 info->perf_event.type = BPF_PERF_EVENT_EVENT; 3844 return 0; 3845 } 3846 3847 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 3848 struct bpf_link_info *info) 3849 { 3850 struct bpf_perf_link *perf_link; 3851 const struct perf_event *event; 3852 3853 perf_link = container_of(link, struct bpf_perf_link, link); 3854 event = perf_get_event(perf_link->perf_file); 3855 if (IS_ERR(event)) 3856 return PTR_ERR(event); 3857 3858 switch (event->prog->type) { 3859 case BPF_PROG_TYPE_PERF_EVENT: 3860 return bpf_perf_link_fill_perf_event(event, info); 3861 case BPF_PROG_TYPE_TRACEPOINT: 3862 return bpf_perf_link_fill_tracepoint(event, info); 3863 case BPF_PROG_TYPE_KPROBE: 3864 return bpf_perf_link_fill_probe(event, info); 3865 default: 3866 return -EOPNOTSUPP; 3867 } 3868 } 3869 3870 static const struct bpf_link_ops bpf_perf_link_lops = { 3871 .release = bpf_perf_link_release, 3872 .dealloc = bpf_perf_link_dealloc, 3873 .fill_link_info = bpf_perf_link_fill_link_info, 3874 }; 3875 3876 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3877 { 3878 struct bpf_link_primer link_primer; 3879 struct bpf_perf_link *link; 3880 struct perf_event *event; 3881 struct file *perf_file; 3882 int err; 3883 3884 if (attr->link_create.flags) 3885 return -EINVAL; 3886 3887 perf_file = perf_event_get(attr->link_create.target_fd); 3888 if (IS_ERR(perf_file)) 3889 return PTR_ERR(perf_file); 3890 3891 link = kzalloc(sizeof(*link), GFP_USER); 3892 if (!link) { 3893 err = -ENOMEM; 3894 goto out_put_file; 3895 } 3896 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog); 3897 link->perf_file = perf_file; 3898 3899 err = bpf_link_prime(&link->link, &link_primer); 3900 if (err) { 3901 kfree(link); 3902 goto out_put_file; 3903 } 3904 3905 event = perf_file->private_data; 3906 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 3907 if (err) { 3908 bpf_link_cleanup(&link_primer); 3909 goto out_put_file; 3910 } 3911 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 3912 bpf_prog_inc(prog); 3913 3914 return bpf_link_settle(&link_primer); 3915 3916 out_put_file: 3917 fput(perf_file); 3918 return err; 3919 } 3920 #else 3921 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 3922 { 3923 return -EOPNOTSUPP; 3924 } 3925 #endif /* CONFIG_PERF_EVENTS */ 3926 3927 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 3928 const char __user *user_tp_name, u64 cookie) 3929 { 3930 struct bpf_link_primer link_primer; 3931 struct bpf_raw_tp_link *link; 3932 struct bpf_raw_event_map *btp; 3933 const char *tp_name; 3934 char buf[128]; 3935 int err; 3936 3937 switch (prog->type) { 3938 case BPF_PROG_TYPE_TRACING: 3939 case BPF_PROG_TYPE_EXT: 3940 case BPF_PROG_TYPE_LSM: 3941 if (user_tp_name) 3942 /* The attach point for this category of programs 3943 * should be specified via btf_id during program load. 3944 */ 3945 return -EINVAL; 3946 if (prog->type == BPF_PROG_TYPE_TRACING && 3947 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 3948 tp_name = prog->aux->attach_func_name; 3949 break; 3950 } 3951 return bpf_tracing_prog_attach(prog, 0, 0, 0); 3952 case BPF_PROG_TYPE_RAW_TRACEPOINT: 3953 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 3954 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 3955 return -EFAULT; 3956 buf[sizeof(buf) - 1] = 0; 3957 tp_name = buf; 3958 break; 3959 default: 3960 return -EINVAL; 3961 } 3962 3963 btp = bpf_get_raw_tracepoint(tp_name); 3964 if (!btp) 3965 return -ENOENT; 3966 3967 link = kzalloc(sizeof(*link), GFP_USER); 3968 if (!link) { 3969 err = -ENOMEM; 3970 goto out_put_btp; 3971 } 3972 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 3973 &bpf_raw_tp_link_lops, prog, 3974 tracepoint_is_faultable(btp->tp)); 3975 link->btp = btp; 3976 link->cookie = cookie; 3977 3978 err = bpf_link_prime(&link->link, &link_primer); 3979 if (err) { 3980 kfree(link); 3981 goto out_put_btp; 3982 } 3983 3984 err = bpf_probe_register(link->btp, link); 3985 if (err) { 3986 bpf_link_cleanup(&link_primer); 3987 goto out_put_btp; 3988 } 3989 3990 return bpf_link_settle(&link_primer); 3991 3992 out_put_btp: 3993 bpf_put_raw_tracepoint(btp); 3994 return err; 3995 } 3996 3997 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 3998 3999 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4000 { 4001 struct bpf_prog *prog; 4002 void __user *tp_name; 4003 __u64 cookie; 4004 int fd; 4005 4006 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4007 return -EINVAL; 4008 4009 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4010 if (IS_ERR(prog)) 4011 return PTR_ERR(prog); 4012 4013 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4014 cookie = attr->raw_tracepoint.cookie; 4015 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie); 4016 if (fd < 0) 4017 bpf_prog_put(prog); 4018 return fd; 4019 } 4020 4021 static enum bpf_prog_type 4022 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4023 { 4024 switch (attach_type) { 4025 case BPF_CGROUP_INET_INGRESS: 4026 case BPF_CGROUP_INET_EGRESS: 4027 return BPF_PROG_TYPE_CGROUP_SKB; 4028 case BPF_CGROUP_INET_SOCK_CREATE: 4029 case BPF_CGROUP_INET_SOCK_RELEASE: 4030 case BPF_CGROUP_INET4_POST_BIND: 4031 case BPF_CGROUP_INET6_POST_BIND: 4032 return BPF_PROG_TYPE_CGROUP_SOCK; 4033 case BPF_CGROUP_INET4_BIND: 4034 case BPF_CGROUP_INET6_BIND: 4035 case BPF_CGROUP_INET4_CONNECT: 4036 case BPF_CGROUP_INET6_CONNECT: 4037 case BPF_CGROUP_UNIX_CONNECT: 4038 case BPF_CGROUP_INET4_GETPEERNAME: 4039 case BPF_CGROUP_INET6_GETPEERNAME: 4040 case BPF_CGROUP_UNIX_GETPEERNAME: 4041 case BPF_CGROUP_INET4_GETSOCKNAME: 4042 case BPF_CGROUP_INET6_GETSOCKNAME: 4043 case BPF_CGROUP_UNIX_GETSOCKNAME: 4044 case BPF_CGROUP_UDP4_SENDMSG: 4045 case BPF_CGROUP_UDP6_SENDMSG: 4046 case BPF_CGROUP_UNIX_SENDMSG: 4047 case BPF_CGROUP_UDP4_RECVMSG: 4048 case BPF_CGROUP_UDP6_RECVMSG: 4049 case BPF_CGROUP_UNIX_RECVMSG: 4050 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4051 case BPF_CGROUP_SOCK_OPS: 4052 return BPF_PROG_TYPE_SOCK_OPS; 4053 case BPF_CGROUP_DEVICE: 4054 return BPF_PROG_TYPE_CGROUP_DEVICE; 4055 case BPF_SK_MSG_VERDICT: 4056 return BPF_PROG_TYPE_SK_MSG; 4057 case BPF_SK_SKB_STREAM_PARSER: 4058 case BPF_SK_SKB_STREAM_VERDICT: 4059 case BPF_SK_SKB_VERDICT: 4060 return BPF_PROG_TYPE_SK_SKB; 4061 case BPF_LIRC_MODE2: 4062 return BPF_PROG_TYPE_LIRC_MODE2; 4063 case BPF_FLOW_DISSECTOR: 4064 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4065 case BPF_CGROUP_SYSCTL: 4066 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4067 case BPF_CGROUP_GETSOCKOPT: 4068 case BPF_CGROUP_SETSOCKOPT: 4069 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4070 case BPF_TRACE_ITER: 4071 case BPF_TRACE_RAW_TP: 4072 case BPF_TRACE_FENTRY: 4073 case BPF_TRACE_FEXIT: 4074 case BPF_MODIFY_RETURN: 4075 return BPF_PROG_TYPE_TRACING; 4076 case BPF_LSM_MAC: 4077 return BPF_PROG_TYPE_LSM; 4078 case BPF_SK_LOOKUP: 4079 return BPF_PROG_TYPE_SK_LOOKUP; 4080 case BPF_XDP: 4081 return BPF_PROG_TYPE_XDP; 4082 case BPF_LSM_CGROUP: 4083 return BPF_PROG_TYPE_LSM; 4084 case BPF_TCX_INGRESS: 4085 case BPF_TCX_EGRESS: 4086 case BPF_NETKIT_PRIMARY: 4087 case BPF_NETKIT_PEER: 4088 return BPF_PROG_TYPE_SCHED_CLS; 4089 default: 4090 return BPF_PROG_TYPE_UNSPEC; 4091 } 4092 } 4093 4094 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4095 enum bpf_attach_type attach_type) 4096 { 4097 enum bpf_prog_type ptype; 4098 4099 switch (prog->type) { 4100 case BPF_PROG_TYPE_CGROUP_SOCK: 4101 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4102 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4103 case BPF_PROG_TYPE_SK_LOOKUP: 4104 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4105 case BPF_PROG_TYPE_CGROUP_SKB: 4106 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4107 /* cg-skb progs can be loaded by unpriv user. 4108 * check permissions at attach time. 4109 */ 4110 return -EPERM; 4111 4112 ptype = attach_type_to_prog_type(attach_type); 4113 if (prog->type != ptype) 4114 return -EINVAL; 4115 4116 return prog->enforce_expected_attach_type && 4117 prog->expected_attach_type != attach_type ? 4118 -EINVAL : 0; 4119 case BPF_PROG_TYPE_EXT: 4120 return 0; 4121 case BPF_PROG_TYPE_NETFILTER: 4122 if (attach_type != BPF_NETFILTER) 4123 return -EINVAL; 4124 return 0; 4125 case BPF_PROG_TYPE_PERF_EVENT: 4126 case BPF_PROG_TYPE_TRACEPOINT: 4127 if (attach_type != BPF_PERF_EVENT) 4128 return -EINVAL; 4129 return 0; 4130 case BPF_PROG_TYPE_KPROBE: 4131 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4132 attach_type != BPF_TRACE_KPROBE_MULTI) 4133 return -EINVAL; 4134 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4135 attach_type != BPF_TRACE_KPROBE_SESSION) 4136 return -EINVAL; 4137 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4138 attach_type != BPF_TRACE_UPROBE_MULTI) 4139 return -EINVAL; 4140 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4141 attach_type != BPF_TRACE_UPROBE_SESSION) 4142 return -EINVAL; 4143 if (attach_type != BPF_PERF_EVENT && 4144 attach_type != BPF_TRACE_KPROBE_MULTI && 4145 attach_type != BPF_TRACE_KPROBE_SESSION && 4146 attach_type != BPF_TRACE_UPROBE_MULTI && 4147 attach_type != BPF_TRACE_UPROBE_SESSION) 4148 return -EINVAL; 4149 return 0; 4150 case BPF_PROG_TYPE_SCHED_CLS: 4151 if (attach_type != BPF_TCX_INGRESS && 4152 attach_type != BPF_TCX_EGRESS && 4153 attach_type != BPF_NETKIT_PRIMARY && 4154 attach_type != BPF_NETKIT_PEER) 4155 return -EINVAL; 4156 return 0; 4157 default: 4158 ptype = attach_type_to_prog_type(attach_type); 4159 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4160 return -EINVAL; 4161 return 0; 4162 } 4163 } 4164 4165 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4166 4167 #define BPF_F_ATTACH_MASK_BASE \ 4168 (BPF_F_ALLOW_OVERRIDE | \ 4169 BPF_F_ALLOW_MULTI | \ 4170 BPF_F_REPLACE | \ 4171 BPF_F_PREORDER) 4172 4173 #define BPF_F_ATTACH_MASK_MPROG \ 4174 (BPF_F_REPLACE | \ 4175 BPF_F_BEFORE | \ 4176 BPF_F_AFTER | \ 4177 BPF_F_ID | \ 4178 BPF_F_LINK) 4179 4180 static int bpf_prog_attach(const union bpf_attr *attr) 4181 { 4182 enum bpf_prog_type ptype; 4183 struct bpf_prog *prog; 4184 int ret; 4185 4186 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4187 return -EINVAL; 4188 4189 ptype = attach_type_to_prog_type(attr->attach_type); 4190 if (ptype == BPF_PROG_TYPE_UNSPEC) 4191 return -EINVAL; 4192 if (bpf_mprog_supported(ptype)) { 4193 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4194 return -EINVAL; 4195 } else { 4196 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4197 return -EINVAL; 4198 if (attr->relative_fd || 4199 attr->expected_revision) 4200 return -EINVAL; 4201 } 4202 4203 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4204 if (IS_ERR(prog)) 4205 return PTR_ERR(prog); 4206 4207 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4208 bpf_prog_put(prog); 4209 return -EINVAL; 4210 } 4211 4212 switch (ptype) { 4213 case BPF_PROG_TYPE_SK_SKB: 4214 case BPF_PROG_TYPE_SK_MSG: 4215 ret = sock_map_get_from_fd(attr, prog); 4216 break; 4217 case BPF_PROG_TYPE_LIRC_MODE2: 4218 ret = lirc_prog_attach(attr, prog); 4219 break; 4220 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4221 ret = netns_bpf_prog_attach(attr, prog); 4222 break; 4223 case BPF_PROG_TYPE_CGROUP_DEVICE: 4224 case BPF_PROG_TYPE_CGROUP_SKB: 4225 case BPF_PROG_TYPE_CGROUP_SOCK: 4226 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4227 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4228 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4229 case BPF_PROG_TYPE_SOCK_OPS: 4230 case BPF_PROG_TYPE_LSM: 4231 if (ptype == BPF_PROG_TYPE_LSM && 4232 prog->expected_attach_type != BPF_LSM_CGROUP) 4233 ret = -EINVAL; 4234 else 4235 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4236 break; 4237 case BPF_PROG_TYPE_SCHED_CLS: 4238 if (attr->attach_type == BPF_TCX_INGRESS || 4239 attr->attach_type == BPF_TCX_EGRESS) 4240 ret = tcx_prog_attach(attr, prog); 4241 else 4242 ret = netkit_prog_attach(attr, prog); 4243 break; 4244 default: 4245 ret = -EINVAL; 4246 } 4247 4248 if (ret) 4249 bpf_prog_put(prog); 4250 return ret; 4251 } 4252 4253 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4254 4255 static int bpf_prog_detach(const union bpf_attr *attr) 4256 { 4257 struct bpf_prog *prog = NULL; 4258 enum bpf_prog_type ptype; 4259 int ret; 4260 4261 if (CHECK_ATTR(BPF_PROG_DETACH)) 4262 return -EINVAL; 4263 4264 ptype = attach_type_to_prog_type(attr->attach_type); 4265 if (bpf_mprog_supported(ptype)) { 4266 if (ptype == BPF_PROG_TYPE_UNSPEC) 4267 return -EINVAL; 4268 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4269 return -EINVAL; 4270 if (attr->attach_bpf_fd) { 4271 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4272 if (IS_ERR(prog)) 4273 return PTR_ERR(prog); 4274 } 4275 } else if (attr->attach_flags || 4276 attr->relative_fd || 4277 attr->expected_revision) { 4278 return -EINVAL; 4279 } 4280 4281 switch (ptype) { 4282 case BPF_PROG_TYPE_SK_MSG: 4283 case BPF_PROG_TYPE_SK_SKB: 4284 ret = sock_map_prog_detach(attr, ptype); 4285 break; 4286 case BPF_PROG_TYPE_LIRC_MODE2: 4287 ret = lirc_prog_detach(attr); 4288 break; 4289 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4290 ret = netns_bpf_prog_detach(attr, ptype); 4291 break; 4292 case BPF_PROG_TYPE_CGROUP_DEVICE: 4293 case BPF_PROG_TYPE_CGROUP_SKB: 4294 case BPF_PROG_TYPE_CGROUP_SOCK: 4295 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4296 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4297 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4298 case BPF_PROG_TYPE_SOCK_OPS: 4299 case BPF_PROG_TYPE_LSM: 4300 ret = cgroup_bpf_prog_detach(attr, ptype); 4301 break; 4302 case BPF_PROG_TYPE_SCHED_CLS: 4303 if (attr->attach_type == BPF_TCX_INGRESS || 4304 attr->attach_type == BPF_TCX_EGRESS) 4305 ret = tcx_prog_detach(attr, prog); 4306 else 4307 ret = netkit_prog_detach(attr, prog); 4308 break; 4309 default: 4310 ret = -EINVAL; 4311 } 4312 4313 if (prog) 4314 bpf_prog_put(prog); 4315 return ret; 4316 } 4317 4318 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4319 4320 static int bpf_prog_query(const union bpf_attr *attr, 4321 union bpf_attr __user *uattr) 4322 { 4323 if (!bpf_net_capable()) 4324 return -EPERM; 4325 if (CHECK_ATTR(BPF_PROG_QUERY)) 4326 return -EINVAL; 4327 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4328 return -EINVAL; 4329 4330 switch (attr->query.attach_type) { 4331 case BPF_CGROUP_INET_INGRESS: 4332 case BPF_CGROUP_INET_EGRESS: 4333 case BPF_CGROUP_INET_SOCK_CREATE: 4334 case BPF_CGROUP_INET_SOCK_RELEASE: 4335 case BPF_CGROUP_INET4_BIND: 4336 case BPF_CGROUP_INET6_BIND: 4337 case BPF_CGROUP_INET4_POST_BIND: 4338 case BPF_CGROUP_INET6_POST_BIND: 4339 case BPF_CGROUP_INET4_CONNECT: 4340 case BPF_CGROUP_INET6_CONNECT: 4341 case BPF_CGROUP_UNIX_CONNECT: 4342 case BPF_CGROUP_INET4_GETPEERNAME: 4343 case BPF_CGROUP_INET6_GETPEERNAME: 4344 case BPF_CGROUP_UNIX_GETPEERNAME: 4345 case BPF_CGROUP_INET4_GETSOCKNAME: 4346 case BPF_CGROUP_INET6_GETSOCKNAME: 4347 case BPF_CGROUP_UNIX_GETSOCKNAME: 4348 case BPF_CGROUP_UDP4_SENDMSG: 4349 case BPF_CGROUP_UDP6_SENDMSG: 4350 case BPF_CGROUP_UNIX_SENDMSG: 4351 case BPF_CGROUP_UDP4_RECVMSG: 4352 case BPF_CGROUP_UDP6_RECVMSG: 4353 case BPF_CGROUP_UNIX_RECVMSG: 4354 case BPF_CGROUP_SOCK_OPS: 4355 case BPF_CGROUP_DEVICE: 4356 case BPF_CGROUP_SYSCTL: 4357 case BPF_CGROUP_GETSOCKOPT: 4358 case BPF_CGROUP_SETSOCKOPT: 4359 case BPF_LSM_CGROUP: 4360 return cgroup_bpf_prog_query(attr, uattr); 4361 case BPF_LIRC_MODE2: 4362 return lirc_prog_query(attr, uattr); 4363 case BPF_FLOW_DISSECTOR: 4364 case BPF_SK_LOOKUP: 4365 return netns_bpf_prog_query(attr, uattr); 4366 case BPF_SK_SKB_STREAM_PARSER: 4367 case BPF_SK_SKB_STREAM_VERDICT: 4368 case BPF_SK_MSG_VERDICT: 4369 case BPF_SK_SKB_VERDICT: 4370 return sock_map_bpf_prog_query(attr, uattr); 4371 case BPF_TCX_INGRESS: 4372 case BPF_TCX_EGRESS: 4373 return tcx_prog_query(attr, uattr); 4374 case BPF_NETKIT_PRIMARY: 4375 case BPF_NETKIT_PEER: 4376 return netkit_prog_query(attr, uattr); 4377 default: 4378 return -EINVAL; 4379 } 4380 } 4381 4382 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4383 4384 static int bpf_prog_test_run(const union bpf_attr *attr, 4385 union bpf_attr __user *uattr) 4386 { 4387 struct bpf_prog *prog; 4388 int ret = -ENOTSUPP; 4389 4390 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4391 return -EINVAL; 4392 4393 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4394 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4395 return -EINVAL; 4396 4397 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4398 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4399 return -EINVAL; 4400 4401 prog = bpf_prog_get(attr->test.prog_fd); 4402 if (IS_ERR(prog)) 4403 return PTR_ERR(prog); 4404 4405 if (prog->aux->ops->test_run) 4406 ret = prog->aux->ops->test_run(prog, attr, uattr); 4407 4408 bpf_prog_put(prog); 4409 return ret; 4410 } 4411 4412 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4413 4414 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4415 union bpf_attr __user *uattr, 4416 struct idr *idr, 4417 spinlock_t *lock) 4418 { 4419 u32 next_id = attr->start_id; 4420 int err = 0; 4421 4422 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4423 return -EINVAL; 4424 4425 if (!capable(CAP_SYS_ADMIN)) 4426 return -EPERM; 4427 4428 next_id++; 4429 spin_lock_bh(lock); 4430 if (!idr_get_next(idr, &next_id)) 4431 err = -ENOENT; 4432 spin_unlock_bh(lock); 4433 4434 if (!err) 4435 err = put_user(next_id, &uattr->next_id); 4436 4437 return err; 4438 } 4439 4440 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4441 { 4442 struct bpf_map *map; 4443 4444 spin_lock_bh(&map_idr_lock); 4445 again: 4446 map = idr_get_next(&map_idr, id); 4447 if (map) { 4448 map = __bpf_map_inc_not_zero(map, false); 4449 if (IS_ERR(map)) { 4450 (*id)++; 4451 goto again; 4452 } 4453 } 4454 spin_unlock_bh(&map_idr_lock); 4455 4456 return map; 4457 } 4458 4459 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4460 { 4461 struct bpf_prog *prog; 4462 4463 spin_lock_bh(&prog_idr_lock); 4464 again: 4465 prog = idr_get_next(&prog_idr, id); 4466 if (prog) { 4467 prog = bpf_prog_inc_not_zero(prog); 4468 if (IS_ERR(prog)) { 4469 (*id)++; 4470 goto again; 4471 } 4472 } 4473 spin_unlock_bh(&prog_idr_lock); 4474 4475 return prog; 4476 } 4477 4478 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4479 4480 struct bpf_prog *bpf_prog_by_id(u32 id) 4481 { 4482 struct bpf_prog *prog; 4483 4484 if (!id) 4485 return ERR_PTR(-ENOENT); 4486 4487 spin_lock_bh(&prog_idr_lock); 4488 prog = idr_find(&prog_idr, id); 4489 if (prog) 4490 prog = bpf_prog_inc_not_zero(prog); 4491 else 4492 prog = ERR_PTR(-ENOENT); 4493 spin_unlock_bh(&prog_idr_lock); 4494 return prog; 4495 } 4496 4497 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4498 { 4499 struct bpf_prog *prog; 4500 u32 id = attr->prog_id; 4501 int fd; 4502 4503 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4504 return -EINVAL; 4505 4506 if (!capable(CAP_SYS_ADMIN)) 4507 return -EPERM; 4508 4509 prog = bpf_prog_by_id(id); 4510 if (IS_ERR(prog)) 4511 return PTR_ERR(prog); 4512 4513 fd = bpf_prog_new_fd(prog); 4514 if (fd < 0) 4515 bpf_prog_put(prog); 4516 4517 return fd; 4518 } 4519 4520 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4521 4522 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4523 { 4524 struct bpf_map *map; 4525 u32 id = attr->map_id; 4526 int f_flags; 4527 int fd; 4528 4529 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4530 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4531 return -EINVAL; 4532 4533 if (!capable(CAP_SYS_ADMIN)) 4534 return -EPERM; 4535 4536 f_flags = bpf_get_file_flag(attr->open_flags); 4537 if (f_flags < 0) 4538 return f_flags; 4539 4540 spin_lock_bh(&map_idr_lock); 4541 map = idr_find(&map_idr, id); 4542 if (map) 4543 map = __bpf_map_inc_not_zero(map, true); 4544 else 4545 map = ERR_PTR(-ENOENT); 4546 spin_unlock_bh(&map_idr_lock); 4547 4548 if (IS_ERR(map)) 4549 return PTR_ERR(map); 4550 4551 fd = bpf_map_new_fd(map, f_flags); 4552 if (fd < 0) 4553 bpf_map_put_with_uref(map); 4554 4555 return fd; 4556 } 4557 4558 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4559 unsigned long addr, u32 *off, 4560 u32 *type) 4561 { 4562 const struct bpf_map *map; 4563 int i; 4564 4565 mutex_lock(&prog->aux->used_maps_mutex); 4566 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4567 map = prog->aux->used_maps[i]; 4568 if (map == (void *)addr) { 4569 *type = BPF_PSEUDO_MAP_FD; 4570 goto out; 4571 } 4572 if (!map->ops->map_direct_value_meta) 4573 continue; 4574 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4575 *type = BPF_PSEUDO_MAP_VALUE; 4576 goto out; 4577 } 4578 } 4579 map = NULL; 4580 4581 out: 4582 mutex_unlock(&prog->aux->used_maps_mutex); 4583 return map; 4584 } 4585 4586 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 4587 const struct cred *f_cred) 4588 { 4589 const struct bpf_map *map; 4590 struct bpf_insn *insns; 4591 u32 off, type; 4592 u64 imm; 4593 u8 code; 4594 int i; 4595 4596 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 4597 GFP_USER); 4598 if (!insns) 4599 return insns; 4600 4601 for (i = 0; i < prog->len; i++) { 4602 code = insns[i].code; 4603 4604 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 4605 insns[i].code = BPF_JMP | BPF_CALL; 4606 insns[i].imm = BPF_FUNC_tail_call; 4607 /* fall-through */ 4608 } 4609 if (code == (BPF_JMP | BPF_CALL) || 4610 code == (BPF_JMP | BPF_CALL_ARGS)) { 4611 if (code == (BPF_JMP | BPF_CALL_ARGS)) 4612 insns[i].code = BPF_JMP | BPF_CALL; 4613 if (!bpf_dump_raw_ok(f_cred)) 4614 insns[i].imm = 0; 4615 continue; 4616 } 4617 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 4618 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 4619 continue; 4620 } 4621 4622 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 4623 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 4624 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 4625 continue; 4626 } 4627 4628 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 4629 continue; 4630 4631 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 4632 map = bpf_map_from_imm(prog, imm, &off, &type); 4633 if (map) { 4634 insns[i].src_reg = type; 4635 insns[i].imm = map->id; 4636 insns[i + 1].imm = off; 4637 continue; 4638 } 4639 } 4640 4641 return insns; 4642 } 4643 4644 static int set_info_rec_size(struct bpf_prog_info *info) 4645 { 4646 /* 4647 * Ensure info.*_rec_size is the same as kernel expected size 4648 * 4649 * or 4650 * 4651 * Only allow zero *_rec_size if both _rec_size and _cnt are 4652 * zero. In this case, the kernel will set the expected 4653 * _rec_size back to the info. 4654 */ 4655 4656 if ((info->nr_func_info || info->func_info_rec_size) && 4657 info->func_info_rec_size != sizeof(struct bpf_func_info)) 4658 return -EINVAL; 4659 4660 if ((info->nr_line_info || info->line_info_rec_size) && 4661 info->line_info_rec_size != sizeof(struct bpf_line_info)) 4662 return -EINVAL; 4663 4664 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 4665 info->jited_line_info_rec_size != sizeof(__u64)) 4666 return -EINVAL; 4667 4668 info->func_info_rec_size = sizeof(struct bpf_func_info); 4669 info->line_info_rec_size = sizeof(struct bpf_line_info); 4670 info->jited_line_info_rec_size = sizeof(__u64); 4671 4672 return 0; 4673 } 4674 4675 static int bpf_prog_get_info_by_fd(struct file *file, 4676 struct bpf_prog *prog, 4677 const union bpf_attr *attr, 4678 union bpf_attr __user *uattr) 4679 { 4680 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4681 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 4682 struct bpf_prog_info info; 4683 u32 info_len = attr->info.info_len; 4684 struct bpf_prog_kstats stats; 4685 char __user *uinsns; 4686 u32 ulen; 4687 int err; 4688 4689 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4690 if (err) 4691 return err; 4692 info_len = min_t(u32, sizeof(info), info_len); 4693 4694 memset(&info, 0, sizeof(info)); 4695 if (copy_from_user(&info, uinfo, info_len)) 4696 return -EFAULT; 4697 4698 info.type = prog->type; 4699 info.id = prog->aux->id; 4700 info.load_time = prog->aux->load_time; 4701 info.created_by_uid = from_kuid_munged(current_user_ns(), 4702 prog->aux->user->uid); 4703 info.gpl_compatible = prog->gpl_compatible; 4704 4705 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 4706 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 4707 4708 mutex_lock(&prog->aux->used_maps_mutex); 4709 ulen = info.nr_map_ids; 4710 info.nr_map_ids = prog->aux->used_map_cnt; 4711 ulen = min_t(u32, info.nr_map_ids, ulen); 4712 if (ulen) { 4713 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 4714 u32 i; 4715 4716 for (i = 0; i < ulen; i++) 4717 if (put_user(prog->aux->used_maps[i]->id, 4718 &user_map_ids[i])) { 4719 mutex_unlock(&prog->aux->used_maps_mutex); 4720 return -EFAULT; 4721 } 4722 } 4723 mutex_unlock(&prog->aux->used_maps_mutex); 4724 4725 err = set_info_rec_size(&info); 4726 if (err) 4727 return err; 4728 4729 bpf_prog_get_stats(prog, &stats); 4730 info.run_time_ns = stats.nsecs; 4731 info.run_cnt = stats.cnt; 4732 info.recursion_misses = stats.misses; 4733 4734 info.verified_insns = prog->aux->verified_insns; 4735 4736 if (!bpf_capable()) { 4737 info.jited_prog_len = 0; 4738 info.xlated_prog_len = 0; 4739 info.nr_jited_ksyms = 0; 4740 info.nr_jited_func_lens = 0; 4741 info.nr_func_info = 0; 4742 info.nr_line_info = 0; 4743 info.nr_jited_line_info = 0; 4744 goto done; 4745 } 4746 4747 ulen = info.xlated_prog_len; 4748 info.xlated_prog_len = bpf_prog_insn_size(prog); 4749 if (info.xlated_prog_len && ulen) { 4750 struct bpf_insn *insns_sanitized; 4751 bool fault; 4752 4753 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) { 4754 info.xlated_prog_insns = 0; 4755 goto done; 4756 } 4757 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 4758 if (!insns_sanitized) 4759 return -ENOMEM; 4760 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 4761 ulen = min_t(u32, info.xlated_prog_len, ulen); 4762 fault = copy_to_user(uinsns, insns_sanitized, ulen); 4763 kfree(insns_sanitized); 4764 if (fault) 4765 return -EFAULT; 4766 } 4767 4768 if (bpf_prog_is_offloaded(prog->aux)) { 4769 err = bpf_prog_offload_info_fill(&info, prog); 4770 if (err) 4771 return err; 4772 goto done; 4773 } 4774 4775 /* NOTE: the following code is supposed to be skipped for offload. 4776 * bpf_prog_offload_info_fill() is the place to fill similar fields 4777 * for offload. 4778 */ 4779 ulen = info.jited_prog_len; 4780 if (prog->aux->func_cnt) { 4781 u32 i; 4782 4783 info.jited_prog_len = 0; 4784 for (i = 0; i < prog->aux->func_cnt; i++) 4785 info.jited_prog_len += prog->aux->func[i]->jited_len; 4786 } else { 4787 info.jited_prog_len = prog->jited_len; 4788 } 4789 4790 if (info.jited_prog_len && ulen) { 4791 if (bpf_dump_raw_ok(file->f_cred)) { 4792 uinsns = u64_to_user_ptr(info.jited_prog_insns); 4793 ulen = min_t(u32, info.jited_prog_len, ulen); 4794 4795 /* for multi-function programs, copy the JITed 4796 * instructions for all the functions 4797 */ 4798 if (prog->aux->func_cnt) { 4799 u32 len, free, i; 4800 u8 *img; 4801 4802 free = ulen; 4803 for (i = 0; i < prog->aux->func_cnt; i++) { 4804 len = prog->aux->func[i]->jited_len; 4805 len = min_t(u32, len, free); 4806 img = (u8 *) prog->aux->func[i]->bpf_func; 4807 if (copy_to_user(uinsns, img, len)) 4808 return -EFAULT; 4809 uinsns += len; 4810 free -= len; 4811 if (!free) 4812 break; 4813 } 4814 } else { 4815 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 4816 return -EFAULT; 4817 } 4818 } else { 4819 info.jited_prog_insns = 0; 4820 } 4821 } 4822 4823 ulen = info.nr_jited_ksyms; 4824 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 4825 if (ulen) { 4826 if (bpf_dump_raw_ok(file->f_cred)) { 4827 unsigned long ksym_addr; 4828 u64 __user *user_ksyms; 4829 u32 i; 4830 4831 /* copy the address of the kernel symbol 4832 * corresponding to each function 4833 */ 4834 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 4835 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 4836 if (prog->aux->func_cnt) { 4837 for (i = 0; i < ulen; i++) { 4838 ksym_addr = (unsigned long) 4839 prog->aux->func[i]->bpf_func; 4840 if (put_user((u64) ksym_addr, 4841 &user_ksyms[i])) 4842 return -EFAULT; 4843 } 4844 } else { 4845 ksym_addr = (unsigned long) prog->bpf_func; 4846 if (put_user((u64) ksym_addr, &user_ksyms[0])) 4847 return -EFAULT; 4848 } 4849 } else { 4850 info.jited_ksyms = 0; 4851 } 4852 } 4853 4854 ulen = info.nr_jited_func_lens; 4855 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 4856 if (ulen) { 4857 if (bpf_dump_raw_ok(file->f_cred)) { 4858 u32 __user *user_lens; 4859 u32 func_len, i; 4860 4861 /* copy the JITed image lengths for each function */ 4862 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 4863 user_lens = u64_to_user_ptr(info.jited_func_lens); 4864 if (prog->aux->func_cnt) { 4865 for (i = 0; i < ulen; i++) { 4866 func_len = 4867 prog->aux->func[i]->jited_len; 4868 if (put_user(func_len, &user_lens[i])) 4869 return -EFAULT; 4870 } 4871 } else { 4872 func_len = prog->jited_len; 4873 if (put_user(func_len, &user_lens[0])) 4874 return -EFAULT; 4875 } 4876 } else { 4877 info.jited_func_lens = 0; 4878 } 4879 } 4880 4881 if (prog->aux->btf) 4882 info.btf_id = btf_obj_id(prog->aux->btf); 4883 info.attach_btf_id = prog->aux->attach_btf_id; 4884 if (attach_btf) 4885 info.attach_btf_obj_id = btf_obj_id(attach_btf); 4886 4887 ulen = info.nr_func_info; 4888 info.nr_func_info = prog->aux->func_info_cnt; 4889 if (info.nr_func_info && ulen) { 4890 char __user *user_finfo; 4891 4892 user_finfo = u64_to_user_ptr(info.func_info); 4893 ulen = min_t(u32, info.nr_func_info, ulen); 4894 if (copy_to_user(user_finfo, prog->aux->func_info, 4895 info.func_info_rec_size * ulen)) 4896 return -EFAULT; 4897 } 4898 4899 ulen = info.nr_line_info; 4900 info.nr_line_info = prog->aux->nr_linfo; 4901 if (info.nr_line_info && ulen) { 4902 __u8 __user *user_linfo; 4903 4904 user_linfo = u64_to_user_ptr(info.line_info); 4905 ulen = min_t(u32, info.nr_line_info, ulen); 4906 if (copy_to_user(user_linfo, prog->aux->linfo, 4907 info.line_info_rec_size * ulen)) 4908 return -EFAULT; 4909 } 4910 4911 ulen = info.nr_jited_line_info; 4912 if (prog->aux->jited_linfo) 4913 info.nr_jited_line_info = prog->aux->nr_linfo; 4914 else 4915 info.nr_jited_line_info = 0; 4916 if (info.nr_jited_line_info && ulen) { 4917 if (bpf_dump_raw_ok(file->f_cred)) { 4918 unsigned long line_addr; 4919 __u64 __user *user_linfo; 4920 u32 i; 4921 4922 user_linfo = u64_to_user_ptr(info.jited_line_info); 4923 ulen = min_t(u32, info.nr_jited_line_info, ulen); 4924 for (i = 0; i < ulen; i++) { 4925 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 4926 if (put_user((__u64)line_addr, &user_linfo[i])) 4927 return -EFAULT; 4928 } 4929 } else { 4930 info.jited_line_info = 0; 4931 } 4932 } 4933 4934 ulen = info.nr_prog_tags; 4935 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 4936 if (ulen) { 4937 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 4938 u32 i; 4939 4940 user_prog_tags = u64_to_user_ptr(info.prog_tags); 4941 ulen = min_t(u32, info.nr_prog_tags, ulen); 4942 if (prog->aux->func_cnt) { 4943 for (i = 0; i < ulen; i++) { 4944 if (copy_to_user(user_prog_tags[i], 4945 prog->aux->func[i]->tag, 4946 BPF_TAG_SIZE)) 4947 return -EFAULT; 4948 } 4949 } else { 4950 if (copy_to_user(user_prog_tags[0], 4951 prog->tag, BPF_TAG_SIZE)) 4952 return -EFAULT; 4953 } 4954 } 4955 4956 done: 4957 if (copy_to_user(uinfo, &info, info_len) || 4958 put_user(info_len, &uattr->info.info_len)) 4959 return -EFAULT; 4960 4961 return 0; 4962 } 4963 4964 static int bpf_map_get_info_by_fd(struct file *file, 4965 struct bpf_map *map, 4966 const union bpf_attr *attr, 4967 union bpf_attr __user *uattr) 4968 { 4969 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4970 struct bpf_map_info info; 4971 u32 info_len = attr->info.info_len; 4972 int err; 4973 4974 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4975 if (err) 4976 return err; 4977 info_len = min_t(u32, sizeof(info), info_len); 4978 4979 memset(&info, 0, sizeof(info)); 4980 info.type = map->map_type; 4981 info.id = map->id; 4982 info.key_size = map->key_size; 4983 info.value_size = map->value_size; 4984 info.max_entries = map->max_entries; 4985 info.map_flags = map->map_flags; 4986 info.map_extra = map->map_extra; 4987 memcpy(info.name, map->name, sizeof(map->name)); 4988 4989 if (map->btf) { 4990 info.btf_id = btf_obj_id(map->btf); 4991 info.btf_key_type_id = map->btf_key_type_id; 4992 info.btf_value_type_id = map->btf_value_type_id; 4993 } 4994 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 4995 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 4996 bpf_map_struct_ops_info_fill(&info, map); 4997 4998 if (bpf_map_is_offloaded(map)) { 4999 err = bpf_map_offload_info_fill(&info, map); 5000 if (err) 5001 return err; 5002 } 5003 5004 if (copy_to_user(uinfo, &info, info_len) || 5005 put_user(info_len, &uattr->info.info_len)) 5006 return -EFAULT; 5007 5008 return 0; 5009 } 5010 5011 static int bpf_btf_get_info_by_fd(struct file *file, 5012 struct btf *btf, 5013 const union bpf_attr *attr, 5014 union bpf_attr __user *uattr) 5015 { 5016 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5017 u32 info_len = attr->info.info_len; 5018 int err; 5019 5020 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5021 if (err) 5022 return err; 5023 5024 return btf_get_info_by_fd(btf, attr, uattr); 5025 } 5026 5027 static int bpf_link_get_info_by_fd(struct file *file, 5028 struct bpf_link *link, 5029 const union bpf_attr *attr, 5030 union bpf_attr __user *uattr) 5031 { 5032 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5033 struct bpf_link_info info; 5034 u32 info_len = attr->info.info_len; 5035 int err; 5036 5037 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5038 if (err) 5039 return err; 5040 info_len = min_t(u32, sizeof(info), info_len); 5041 5042 memset(&info, 0, sizeof(info)); 5043 if (copy_from_user(&info, uinfo, info_len)) 5044 return -EFAULT; 5045 5046 info.type = link->type; 5047 info.id = link->id; 5048 if (link->prog) 5049 info.prog_id = link->prog->aux->id; 5050 5051 if (link->ops->fill_link_info) { 5052 err = link->ops->fill_link_info(link, &info); 5053 if (err) 5054 return err; 5055 } 5056 5057 if (copy_to_user(uinfo, &info, info_len) || 5058 put_user(info_len, &uattr->info.info_len)) 5059 return -EFAULT; 5060 5061 return 0; 5062 } 5063 5064 5065 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5066 5067 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5068 union bpf_attr __user *uattr) 5069 { 5070 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5071 return -EINVAL; 5072 5073 CLASS(fd, f)(attr->info.bpf_fd); 5074 if (fd_empty(f)) 5075 return -EBADFD; 5076 5077 if (fd_file(f)->f_op == &bpf_prog_fops) 5078 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5079 uattr); 5080 else if (fd_file(f)->f_op == &bpf_map_fops) 5081 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5082 uattr); 5083 else if (fd_file(f)->f_op == &btf_fops) 5084 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5085 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5086 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5087 attr, uattr); 5088 return -EINVAL; 5089 } 5090 5091 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5092 5093 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) 5094 { 5095 struct bpf_token *token = NULL; 5096 5097 if (CHECK_ATTR(BPF_BTF_LOAD)) 5098 return -EINVAL; 5099 5100 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5101 return -EINVAL; 5102 5103 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5104 token = bpf_token_get_from_fd(attr->btf_token_fd); 5105 if (IS_ERR(token)) 5106 return PTR_ERR(token); 5107 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5108 bpf_token_put(token); 5109 token = NULL; 5110 } 5111 } 5112 5113 if (!bpf_token_capable(token, CAP_BPF)) { 5114 bpf_token_put(token); 5115 return -EPERM; 5116 } 5117 5118 bpf_token_put(token); 5119 5120 return btf_new_fd(attr, uattr, uattr_size); 5121 } 5122 5123 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id 5124 5125 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5126 { 5127 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5128 return -EINVAL; 5129 5130 if (!capable(CAP_SYS_ADMIN)) 5131 return -EPERM; 5132 5133 return btf_get_fd_by_id(attr->btf_id); 5134 } 5135 5136 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5137 union bpf_attr __user *uattr, 5138 u32 prog_id, u32 fd_type, 5139 const char *buf, u64 probe_offset, 5140 u64 probe_addr) 5141 { 5142 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5143 u32 len = buf ? strlen(buf) : 0, input_len; 5144 int err = 0; 5145 5146 if (put_user(len, &uattr->task_fd_query.buf_len)) 5147 return -EFAULT; 5148 input_len = attr->task_fd_query.buf_len; 5149 if (input_len && ubuf) { 5150 if (!len) { 5151 /* nothing to copy, just make ubuf NULL terminated */ 5152 char zero = '\0'; 5153 5154 if (put_user(zero, ubuf)) 5155 return -EFAULT; 5156 } else if (input_len >= len + 1) { 5157 /* ubuf can hold the string with NULL terminator */ 5158 if (copy_to_user(ubuf, buf, len + 1)) 5159 return -EFAULT; 5160 } else { 5161 /* ubuf cannot hold the string with NULL terminator, 5162 * do a partial copy with NULL terminator. 5163 */ 5164 char zero = '\0'; 5165 5166 err = -ENOSPC; 5167 if (copy_to_user(ubuf, buf, input_len - 1)) 5168 return -EFAULT; 5169 if (put_user(zero, ubuf + input_len - 1)) 5170 return -EFAULT; 5171 } 5172 } 5173 5174 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5175 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5176 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5177 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5178 return -EFAULT; 5179 5180 return err; 5181 } 5182 5183 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5184 5185 static int bpf_task_fd_query(const union bpf_attr *attr, 5186 union bpf_attr __user *uattr) 5187 { 5188 pid_t pid = attr->task_fd_query.pid; 5189 u32 fd = attr->task_fd_query.fd; 5190 const struct perf_event *event; 5191 struct task_struct *task; 5192 struct file *file; 5193 int err; 5194 5195 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5196 return -EINVAL; 5197 5198 if (!capable(CAP_SYS_ADMIN)) 5199 return -EPERM; 5200 5201 if (attr->task_fd_query.flags != 0) 5202 return -EINVAL; 5203 5204 rcu_read_lock(); 5205 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5206 rcu_read_unlock(); 5207 if (!task) 5208 return -ENOENT; 5209 5210 err = 0; 5211 file = fget_task(task, fd); 5212 put_task_struct(task); 5213 if (!file) 5214 return -EBADF; 5215 5216 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5217 struct bpf_link *link = file->private_data; 5218 5219 if (link->ops == &bpf_raw_tp_link_lops) { 5220 struct bpf_raw_tp_link *raw_tp = 5221 container_of(link, struct bpf_raw_tp_link, link); 5222 struct bpf_raw_event_map *btp = raw_tp->btp; 5223 5224 err = bpf_task_fd_query_copy(attr, uattr, 5225 raw_tp->link.prog->aux->id, 5226 BPF_FD_TYPE_RAW_TRACEPOINT, 5227 btp->tp->name, 0, 0); 5228 goto put_file; 5229 } 5230 goto out_not_supp; 5231 } 5232 5233 event = perf_get_event(file); 5234 if (!IS_ERR(event)) { 5235 u64 probe_offset, probe_addr; 5236 u32 prog_id, fd_type; 5237 const char *buf; 5238 5239 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5240 &buf, &probe_offset, 5241 &probe_addr, NULL); 5242 if (!err) 5243 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5244 fd_type, buf, 5245 probe_offset, 5246 probe_addr); 5247 goto put_file; 5248 } 5249 5250 out_not_supp: 5251 err = -ENOTSUPP; 5252 put_file: 5253 fput(file); 5254 return err; 5255 } 5256 5257 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5258 5259 #define BPF_DO_BATCH(fn, ...) \ 5260 do { \ 5261 if (!fn) { \ 5262 err = -ENOTSUPP; \ 5263 goto err_put; \ 5264 } \ 5265 err = fn(__VA_ARGS__); \ 5266 } while (0) 5267 5268 static int bpf_map_do_batch(const union bpf_attr *attr, 5269 union bpf_attr __user *uattr, 5270 int cmd) 5271 { 5272 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5273 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5274 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5275 struct bpf_map *map; 5276 int err; 5277 5278 if (CHECK_ATTR(BPF_MAP_BATCH)) 5279 return -EINVAL; 5280 5281 CLASS(fd, f)(attr->batch.map_fd); 5282 5283 map = __bpf_map_get(f); 5284 if (IS_ERR(map)) 5285 return PTR_ERR(map); 5286 if (has_write) 5287 bpf_map_write_active_inc(map); 5288 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5289 err = -EPERM; 5290 goto err_put; 5291 } 5292 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5293 err = -EPERM; 5294 goto err_put; 5295 } 5296 5297 if (cmd == BPF_MAP_LOOKUP_BATCH) 5298 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5299 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5300 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5301 else if (cmd == BPF_MAP_UPDATE_BATCH) 5302 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5303 else 5304 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5305 err_put: 5306 if (has_write) { 5307 maybe_wait_bpf_programs(map); 5308 bpf_map_write_active_dec(map); 5309 } 5310 return err; 5311 } 5312 5313 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 5314 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5315 { 5316 struct bpf_prog *prog; 5317 int ret; 5318 5319 if (CHECK_ATTR(BPF_LINK_CREATE)) 5320 return -EINVAL; 5321 5322 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5323 return bpf_struct_ops_link_create(attr); 5324 5325 prog = bpf_prog_get(attr->link_create.prog_fd); 5326 if (IS_ERR(prog)) 5327 return PTR_ERR(prog); 5328 5329 ret = bpf_prog_attach_check_attach_type(prog, 5330 attr->link_create.attach_type); 5331 if (ret) 5332 goto out; 5333 5334 switch (prog->type) { 5335 case BPF_PROG_TYPE_CGROUP_SKB: 5336 case BPF_PROG_TYPE_CGROUP_SOCK: 5337 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5338 case BPF_PROG_TYPE_SOCK_OPS: 5339 case BPF_PROG_TYPE_CGROUP_DEVICE: 5340 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5341 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5342 ret = cgroup_bpf_link_attach(attr, prog); 5343 break; 5344 case BPF_PROG_TYPE_EXT: 5345 ret = bpf_tracing_prog_attach(prog, 5346 attr->link_create.target_fd, 5347 attr->link_create.target_btf_id, 5348 attr->link_create.tracing.cookie); 5349 break; 5350 case BPF_PROG_TYPE_LSM: 5351 case BPF_PROG_TYPE_TRACING: 5352 if (attr->link_create.attach_type != prog->expected_attach_type) { 5353 ret = -EINVAL; 5354 goto out; 5355 } 5356 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5357 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie); 5358 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5359 ret = bpf_iter_link_attach(attr, uattr, prog); 5360 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5361 ret = cgroup_bpf_link_attach(attr, prog); 5362 else 5363 ret = bpf_tracing_prog_attach(prog, 5364 attr->link_create.target_fd, 5365 attr->link_create.target_btf_id, 5366 attr->link_create.tracing.cookie); 5367 break; 5368 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5369 case BPF_PROG_TYPE_SK_LOOKUP: 5370 ret = netns_bpf_link_create(attr, prog); 5371 break; 5372 case BPF_PROG_TYPE_SK_MSG: 5373 case BPF_PROG_TYPE_SK_SKB: 5374 ret = sock_map_link_create(attr, prog); 5375 break; 5376 #ifdef CONFIG_NET 5377 case BPF_PROG_TYPE_XDP: 5378 ret = bpf_xdp_link_attach(attr, prog); 5379 break; 5380 case BPF_PROG_TYPE_SCHED_CLS: 5381 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5382 attr->link_create.attach_type == BPF_TCX_EGRESS) 5383 ret = tcx_link_attach(attr, prog); 5384 else 5385 ret = netkit_link_attach(attr, prog); 5386 break; 5387 case BPF_PROG_TYPE_NETFILTER: 5388 ret = bpf_nf_link_attach(attr, prog); 5389 break; 5390 #endif 5391 case BPF_PROG_TYPE_PERF_EVENT: 5392 case BPF_PROG_TYPE_TRACEPOINT: 5393 ret = bpf_perf_link_attach(attr, prog); 5394 break; 5395 case BPF_PROG_TYPE_KPROBE: 5396 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5397 ret = bpf_perf_link_attach(attr, prog); 5398 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5399 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5400 ret = bpf_kprobe_multi_link_attach(attr, prog); 5401 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5402 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5403 ret = bpf_uprobe_multi_link_attach(attr, prog); 5404 break; 5405 default: 5406 ret = -EINVAL; 5407 } 5408 5409 out: 5410 if (ret < 0) 5411 bpf_prog_put(prog); 5412 return ret; 5413 } 5414 5415 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5416 { 5417 struct bpf_map *new_map, *old_map = NULL; 5418 int ret; 5419 5420 new_map = bpf_map_get(attr->link_update.new_map_fd); 5421 if (IS_ERR(new_map)) 5422 return PTR_ERR(new_map); 5423 5424 if (attr->link_update.flags & BPF_F_REPLACE) { 5425 old_map = bpf_map_get(attr->link_update.old_map_fd); 5426 if (IS_ERR(old_map)) { 5427 ret = PTR_ERR(old_map); 5428 goto out_put; 5429 } 5430 } else if (attr->link_update.old_map_fd) { 5431 ret = -EINVAL; 5432 goto out_put; 5433 } 5434 5435 ret = link->ops->update_map(link, new_map, old_map); 5436 5437 if (old_map) 5438 bpf_map_put(old_map); 5439 out_put: 5440 bpf_map_put(new_map); 5441 return ret; 5442 } 5443 5444 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5445 5446 static int link_update(union bpf_attr *attr) 5447 { 5448 struct bpf_prog *old_prog = NULL, *new_prog; 5449 struct bpf_link *link; 5450 u32 flags; 5451 int ret; 5452 5453 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5454 return -EINVAL; 5455 5456 flags = attr->link_update.flags; 5457 if (flags & ~BPF_F_REPLACE) 5458 return -EINVAL; 5459 5460 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5461 if (IS_ERR(link)) 5462 return PTR_ERR(link); 5463 5464 if (link->ops->update_map) { 5465 ret = link_update_map(link, attr); 5466 goto out_put_link; 5467 } 5468 5469 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5470 if (IS_ERR(new_prog)) { 5471 ret = PTR_ERR(new_prog); 5472 goto out_put_link; 5473 } 5474 5475 if (flags & BPF_F_REPLACE) { 5476 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5477 if (IS_ERR(old_prog)) { 5478 ret = PTR_ERR(old_prog); 5479 old_prog = NULL; 5480 goto out_put_progs; 5481 } 5482 } else if (attr->link_update.old_prog_fd) { 5483 ret = -EINVAL; 5484 goto out_put_progs; 5485 } 5486 5487 if (link->ops->update_prog) 5488 ret = link->ops->update_prog(link, new_prog, old_prog); 5489 else 5490 ret = -EINVAL; 5491 5492 out_put_progs: 5493 if (old_prog) 5494 bpf_prog_put(old_prog); 5495 if (ret) 5496 bpf_prog_put(new_prog); 5497 out_put_link: 5498 bpf_link_put_direct(link); 5499 return ret; 5500 } 5501 5502 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5503 5504 static int link_detach(union bpf_attr *attr) 5505 { 5506 struct bpf_link *link; 5507 int ret; 5508 5509 if (CHECK_ATTR(BPF_LINK_DETACH)) 5510 return -EINVAL; 5511 5512 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 5513 if (IS_ERR(link)) 5514 return PTR_ERR(link); 5515 5516 if (link->ops->detach) 5517 ret = link->ops->detach(link); 5518 else 5519 ret = -EOPNOTSUPP; 5520 5521 bpf_link_put_direct(link); 5522 return ret; 5523 } 5524 5525 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 5526 { 5527 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 5528 } 5529 EXPORT_SYMBOL(bpf_link_inc_not_zero); 5530 5531 struct bpf_link *bpf_link_by_id(u32 id) 5532 { 5533 struct bpf_link *link; 5534 5535 if (!id) 5536 return ERR_PTR(-ENOENT); 5537 5538 spin_lock_bh(&link_idr_lock); 5539 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 5540 link = idr_find(&link_idr, id); 5541 if (link) { 5542 if (link->id) 5543 link = bpf_link_inc_not_zero(link); 5544 else 5545 link = ERR_PTR(-EAGAIN); 5546 } else { 5547 link = ERR_PTR(-ENOENT); 5548 } 5549 spin_unlock_bh(&link_idr_lock); 5550 return link; 5551 } 5552 5553 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 5554 { 5555 struct bpf_link *link; 5556 5557 spin_lock_bh(&link_idr_lock); 5558 again: 5559 link = idr_get_next(&link_idr, id); 5560 if (link) { 5561 link = bpf_link_inc_not_zero(link); 5562 if (IS_ERR(link)) { 5563 (*id)++; 5564 goto again; 5565 } 5566 } 5567 spin_unlock_bh(&link_idr_lock); 5568 5569 return link; 5570 } 5571 5572 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 5573 5574 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 5575 { 5576 struct bpf_link *link; 5577 u32 id = attr->link_id; 5578 int fd; 5579 5580 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 5581 return -EINVAL; 5582 5583 if (!capable(CAP_SYS_ADMIN)) 5584 return -EPERM; 5585 5586 link = bpf_link_by_id(id); 5587 if (IS_ERR(link)) 5588 return PTR_ERR(link); 5589 5590 fd = bpf_link_new_fd(link); 5591 if (fd < 0) 5592 bpf_link_put_direct(link); 5593 5594 return fd; 5595 } 5596 5597 DEFINE_MUTEX(bpf_stats_enabled_mutex); 5598 5599 static int bpf_stats_release(struct inode *inode, struct file *file) 5600 { 5601 mutex_lock(&bpf_stats_enabled_mutex); 5602 static_key_slow_dec(&bpf_stats_enabled_key.key); 5603 mutex_unlock(&bpf_stats_enabled_mutex); 5604 return 0; 5605 } 5606 5607 static const struct file_operations bpf_stats_fops = { 5608 .release = bpf_stats_release, 5609 }; 5610 5611 static int bpf_enable_runtime_stats(void) 5612 { 5613 int fd; 5614 5615 mutex_lock(&bpf_stats_enabled_mutex); 5616 5617 /* Set a very high limit to avoid overflow */ 5618 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 5619 mutex_unlock(&bpf_stats_enabled_mutex); 5620 return -EBUSY; 5621 } 5622 5623 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 5624 if (fd >= 0) 5625 static_key_slow_inc(&bpf_stats_enabled_key.key); 5626 5627 mutex_unlock(&bpf_stats_enabled_mutex); 5628 return fd; 5629 } 5630 5631 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 5632 5633 static int bpf_enable_stats(union bpf_attr *attr) 5634 { 5635 5636 if (CHECK_ATTR(BPF_ENABLE_STATS)) 5637 return -EINVAL; 5638 5639 if (!capable(CAP_SYS_ADMIN)) 5640 return -EPERM; 5641 5642 switch (attr->enable_stats.type) { 5643 case BPF_STATS_RUN_TIME: 5644 return bpf_enable_runtime_stats(); 5645 default: 5646 break; 5647 } 5648 return -EINVAL; 5649 } 5650 5651 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 5652 5653 static int bpf_iter_create(union bpf_attr *attr) 5654 { 5655 struct bpf_link *link; 5656 int err; 5657 5658 if (CHECK_ATTR(BPF_ITER_CREATE)) 5659 return -EINVAL; 5660 5661 if (attr->iter_create.flags) 5662 return -EINVAL; 5663 5664 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 5665 if (IS_ERR(link)) 5666 return PTR_ERR(link); 5667 5668 err = bpf_iter_new_fd(link); 5669 bpf_link_put_direct(link); 5670 5671 return err; 5672 } 5673 5674 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 5675 5676 static int bpf_prog_bind_map(union bpf_attr *attr) 5677 { 5678 struct bpf_prog *prog; 5679 struct bpf_map *map; 5680 struct bpf_map **used_maps_old, **used_maps_new; 5681 int i, ret = 0; 5682 5683 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 5684 return -EINVAL; 5685 5686 if (attr->prog_bind_map.flags) 5687 return -EINVAL; 5688 5689 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 5690 if (IS_ERR(prog)) 5691 return PTR_ERR(prog); 5692 5693 map = bpf_map_get(attr->prog_bind_map.map_fd); 5694 if (IS_ERR(map)) { 5695 ret = PTR_ERR(map); 5696 goto out_prog_put; 5697 } 5698 5699 mutex_lock(&prog->aux->used_maps_mutex); 5700 5701 used_maps_old = prog->aux->used_maps; 5702 5703 for (i = 0; i < prog->aux->used_map_cnt; i++) 5704 if (used_maps_old[i] == map) { 5705 bpf_map_put(map); 5706 goto out_unlock; 5707 } 5708 5709 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, 5710 sizeof(used_maps_new[0]), 5711 GFP_KERNEL); 5712 if (!used_maps_new) { 5713 ret = -ENOMEM; 5714 goto out_unlock; 5715 } 5716 5717 /* The bpf program will not access the bpf map, but for the sake of 5718 * simplicity, increase sleepable_refcnt for sleepable program as well. 5719 */ 5720 if (prog->sleepable) 5721 atomic64_inc(&map->sleepable_refcnt); 5722 memcpy(used_maps_new, used_maps_old, 5723 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 5724 used_maps_new[prog->aux->used_map_cnt] = map; 5725 5726 prog->aux->used_map_cnt++; 5727 prog->aux->used_maps = used_maps_new; 5728 5729 kfree(used_maps_old); 5730 5731 out_unlock: 5732 mutex_unlock(&prog->aux->used_maps_mutex); 5733 5734 if (ret) 5735 bpf_map_put(map); 5736 out_prog_put: 5737 bpf_prog_put(prog); 5738 return ret; 5739 } 5740 5741 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 5742 5743 static int token_create(union bpf_attr *attr) 5744 { 5745 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 5746 return -EINVAL; 5747 5748 /* no flags are supported yet */ 5749 if (attr->token_create.flags) 5750 return -EINVAL; 5751 5752 return bpf_token_create(attr); 5753 } 5754 5755 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size) 5756 { 5757 union bpf_attr attr; 5758 int err; 5759 5760 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 5761 if (err) 5762 return err; 5763 size = min_t(u32, size, sizeof(attr)); 5764 5765 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 5766 memset(&attr, 0, sizeof(attr)); 5767 if (copy_from_bpfptr(&attr, uattr, size) != 0) 5768 return -EFAULT; 5769 5770 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 5771 if (err < 0) 5772 return err; 5773 5774 switch (cmd) { 5775 case BPF_MAP_CREATE: 5776 err = map_create(&attr, uattr.is_kernel); 5777 break; 5778 case BPF_MAP_LOOKUP_ELEM: 5779 err = map_lookup_elem(&attr); 5780 break; 5781 case BPF_MAP_UPDATE_ELEM: 5782 err = map_update_elem(&attr, uattr); 5783 break; 5784 case BPF_MAP_DELETE_ELEM: 5785 err = map_delete_elem(&attr, uattr); 5786 break; 5787 case BPF_MAP_GET_NEXT_KEY: 5788 err = map_get_next_key(&attr); 5789 break; 5790 case BPF_MAP_FREEZE: 5791 err = map_freeze(&attr); 5792 break; 5793 case BPF_PROG_LOAD: 5794 err = bpf_prog_load(&attr, uattr, size); 5795 break; 5796 case BPF_OBJ_PIN: 5797 err = bpf_obj_pin(&attr); 5798 break; 5799 case BPF_OBJ_GET: 5800 err = bpf_obj_get(&attr); 5801 break; 5802 case BPF_PROG_ATTACH: 5803 err = bpf_prog_attach(&attr); 5804 break; 5805 case BPF_PROG_DETACH: 5806 err = bpf_prog_detach(&attr); 5807 break; 5808 case BPF_PROG_QUERY: 5809 err = bpf_prog_query(&attr, uattr.user); 5810 break; 5811 case BPF_PROG_TEST_RUN: 5812 err = bpf_prog_test_run(&attr, uattr.user); 5813 break; 5814 case BPF_PROG_GET_NEXT_ID: 5815 err = bpf_obj_get_next_id(&attr, uattr.user, 5816 &prog_idr, &prog_idr_lock); 5817 break; 5818 case BPF_MAP_GET_NEXT_ID: 5819 err = bpf_obj_get_next_id(&attr, uattr.user, 5820 &map_idr, &map_idr_lock); 5821 break; 5822 case BPF_BTF_GET_NEXT_ID: 5823 err = bpf_obj_get_next_id(&attr, uattr.user, 5824 &btf_idr, &btf_idr_lock); 5825 break; 5826 case BPF_PROG_GET_FD_BY_ID: 5827 err = bpf_prog_get_fd_by_id(&attr); 5828 break; 5829 case BPF_MAP_GET_FD_BY_ID: 5830 err = bpf_map_get_fd_by_id(&attr); 5831 break; 5832 case BPF_OBJ_GET_INFO_BY_FD: 5833 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 5834 break; 5835 case BPF_RAW_TRACEPOINT_OPEN: 5836 err = bpf_raw_tracepoint_open(&attr); 5837 break; 5838 case BPF_BTF_LOAD: 5839 err = bpf_btf_load(&attr, uattr, size); 5840 break; 5841 case BPF_BTF_GET_FD_BY_ID: 5842 err = bpf_btf_get_fd_by_id(&attr); 5843 break; 5844 case BPF_TASK_FD_QUERY: 5845 err = bpf_task_fd_query(&attr, uattr.user); 5846 break; 5847 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 5848 err = map_lookup_and_delete_elem(&attr); 5849 break; 5850 case BPF_MAP_LOOKUP_BATCH: 5851 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 5852 break; 5853 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 5854 err = bpf_map_do_batch(&attr, uattr.user, 5855 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 5856 break; 5857 case BPF_MAP_UPDATE_BATCH: 5858 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 5859 break; 5860 case BPF_MAP_DELETE_BATCH: 5861 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 5862 break; 5863 case BPF_LINK_CREATE: 5864 err = link_create(&attr, uattr); 5865 break; 5866 case BPF_LINK_UPDATE: 5867 err = link_update(&attr); 5868 break; 5869 case BPF_LINK_GET_FD_BY_ID: 5870 err = bpf_link_get_fd_by_id(&attr); 5871 break; 5872 case BPF_LINK_GET_NEXT_ID: 5873 err = bpf_obj_get_next_id(&attr, uattr.user, 5874 &link_idr, &link_idr_lock); 5875 break; 5876 case BPF_ENABLE_STATS: 5877 err = bpf_enable_stats(&attr); 5878 break; 5879 case BPF_ITER_CREATE: 5880 err = bpf_iter_create(&attr); 5881 break; 5882 case BPF_LINK_DETACH: 5883 err = link_detach(&attr); 5884 break; 5885 case BPF_PROG_BIND_MAP: 5886 err = bpf_prog_bind_map(&attr); 5887 break; 5888 case BPF_TOKEN_CREATE: 5889 err = token_create(&attr); 5890 break; 5891 default: 5892 err = -EINVAL; 5893 break; 5894 } 5895 5896 return err; 5897 } 5898 5899 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) 5900 { 5901 return __sys_bpf(cmd, USER_BPFPTR(uattr), size); 5902 } 5903 5904 static bool syscall_prog_is_valid_access(int off, int size, 5905 enum bpf_access_type type, 5906 const struct bpf_prog *prog, 5907 struct bpf_insn_access_aux *info) 5908 { 5909 if (off < 0 || off >= U16_MAX) 5910 return false; 5911 if (off % size != 0) 5912 return false; 5913 return true; 5914 } 5915 5916 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 5917 { 5918 switch (cmd) { 5919 case BPF_MAP_CREATE: 5920 case BPF_MAP_DELETE_ELEM: 5921 case BPF_MAP_UPDATE_ELEM: 5922 case BPF_MAP_FREEZE: 5923 case BPF_MAP_GET_FD_BY_ID: 5924 case BPF_PROG_LOAD: 5925 case BPF_BTF_LOAD: 5926 case BPF_LINK_CREATE: 5927 case BPF_RAW_TRACEPOINT_OPEN: 5928 break; 5929 default: 5930 return -EINVAL; 5931 } 5932 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); 5933 } 5934 5935 5936 /* To shut up -Wmissing-prototypes. 5937 * This function is used by the kernel light skeleton 5938 * to load bpf programs when modules are loaded or during kernel boot. 5939 * See tools/lib/bpf/skel_internal.h 5940 */ 5941 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 5942 5943 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 5944 { 5945 struct bpf_prog * __maybe_unused prog; 5946 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 5947 5948 switch (cmd) { 5949 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 5950 case BPF_PROG_TEST_RUN: 5951 if (attr->test.data_in || attr->test.data_out || 5952 attr->test.ctx_out || attr->test.duration || 5953 attr->test.repeat || attr->test.flags) 5954 return -EINVAL; 5955 5956 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 5957 if (IS_ERR(prog)) 5958 return PTR_ERR(prog); 5959 5960 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 5961 attr->test.ctx_size_in > U16_MAX) { 5962 bpf_prog_put(prog); 5963 return -EINVAL; 5964 } 5965 5966 run_ctx.bpf_cookie = 0; 5967 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 5968 /* recursion detected */ 5969 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 5970 bpf_prog_put(prog); 5971 return -EBUSY; 5972 } 5973 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 5974 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 5975 &run_ctx); 5976 bpf_prog_put(prog); 5977 return 0; 5978 #endif 5979 default: 5980 return ____bpf_sys_bpf(cmd, attr, size); 5981 } 5982 } 5983 EXPORT_SYMBOL(kern_sys_bpf); 5984 5985 static const struct bpf_func_proto bpf_sys_bpf_proto = { 5986 .func = bpf_sys_bpf, 5987 .gpl_only = false, 5988 .ret_type = RET_INTEGER, 5989 .arg1_type = ARG_ANYTHING, 5990 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 5991 .arg3_type = ARG_CONST_SIZE, 5992 }; 5993 5994 const struct bpf_func_proto * __weak 5995 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 5996 { 5997 return bpf_base_func_proto(func_id, prog); 5998 } 5999 6000 BPF_CALL_1(bpf_sys_close, u32, fd) 6001 { 6002 /* When bpf program calls this helper there should not be 6003 * an fdget() without matching completed fdput(). 6004 * This helper is allowed in the following callchain only: 6005 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6006 */ 6007 return close_fd(fd); 6008 } 6009 6010 static const struct bpf_func_proto bpf_sys_close_proto = { 6011 .func = bpf_sys_close, 6012 .gpl_only = false, 6013 .ret_type = RET_INTEGER, 6014 .arg1_type = ARG_ANYTHING, 6015 }; 6016 6017 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6018 { 6019 *res = 0; 6020 if (flags) 6021 return -EINVAL; 6022 6023 if (name_sz <= 1 || name[name_sz - 1]) 6024 return -EINVAL; 6025 6026 if (!bpf_dump_raw_ok(current_cred())) 6027 return -EPERM; 6028 6029 *res = kallsyms_lookup_name(name); 6030 return *res ? 0 : -ENOENT; 6031 } 6032 6033 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6034 .func = bpf_kallsyms_lookup_name, 6035 .gpl_only = false, 6036 .ret_type = RET_INTEGER, 6037 .arg1_type = ARG_PTR_TO_MEM, 6038 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 6039 .arg3_type = ARG_ANYTHING, 6040 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6041 .arg4_size = sizeof(u64), 6042 }; 6043 6044 static const struct bpf_func_proto * 6045 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6046 { 6047 switch (func_id) { 6048 case BPF_FUNC_sys_bpf: 6049 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6050 ? NULL : &bpf_sys_bpf_proto; 6051 case BPF_FUNC_btf_find_by_name_kind: 6052 return &bpf_btf_find_by_name_kind_proto; 6053 case BPF_FUNC_sys_close: 6054 return &bpf_sys_close_proto; 6055 case BPF_FUNC_kallsyms_lookup_name: 6056 return &bpf_kallsyms_lookup_name_proto; 6057 default: 6058 return tracing_prog_func_proto(func_id, prog); 6059 } 6060 } 6061 6062 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6063 .get_func_proto = syscall_prog_func_proto, 6064 .is_valid_access = syscall_prog_is_valid_access, 6065 }; 6066 6067 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6068 .test_run = bpf_prog_test_run_syscall, 6069 }; 6070 6071 #ifdef CONFIG_SYSCTL 6072 static int bpf_stats_handler(const struct ctl_table *table, int write, 6073 void *buffer, size_t *lenp, loff_t *ppos) 6074 { 6075 struct static_key *key = (struct static_key *)table->data; 6076 static int saved_val; 6077 int val, ret; 6078 struct ctl_table tmp = { 6079 .data = &val, 6080 .maxlen = sizeof(val), 6081 .mode = table->mode, 6082 .extra1 = SYSCTL_ZERO, 6083 .extra2 = SYSCTL_ONE, 6084 }; 6085 6086 if (write && !capable(CAP_SYS_ADMIN)) 6087 return -EPERM; 6088 6089 mutex_lock(&bpf_stats_enabled_mutex); 6090 val = saved_val; 6091 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6092 if (write && !ret && val != saved_val) { 6093 if (val) 6094 static_key_slow_inc(key); 6095 else 6096 static_key_slow_dec(key); 6097 saved_val = val; 6098 } 6099 mutex_unlock(&bpf_stats_enabled_mutex); 6100 return ret; 6101 } 6102 6103 void __weak unpriv_ebpf_notify(int new_state) 6104 { 6105 } 6106 6107 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6108 void *buffer, size_t *lenp, loff_t *ppos) 6109 { 6110 int ret, unpriv_enable = *(int *)table->data; 6111 bool locked_state = unpriv_enable == 1; 6112 struct ctl_table tmp = *table; 6113 6114 if (write && !capable(CAP_SYS_ADMIN)) 6115 return -EPERM; 6116 6117 tmp.data = &unpriv_enable; 6118 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6119 if (write && !ret) { 6120 if (locked_state && unpriv_enable != 1) 6121 return -EPERM; 6122 *(int *)table->data = unpriv_enable; 6123 } 6124 6125 if (write) 6126 unpriv_ebpf_notify(unpriv_enable); 6127 6128 return ret; 6129 } 6130 6131 static const struct ctl_table bpf_syscall_table[] = { 6132 { 6133 .procname = "unprivileged_bpf_disabled", 6134 .data = &sysctl_unprivileged_bpf_disabled, 6135 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6136 .mode = 0644, 6137 .proc_handler = bpf_unpriv_handler, 6138 .extra1 = SYSCTL_ZERO, 6139 .extra2 = SYSCTL_TWO, 6140 }, 6141 { 6142 .procname = "bpf_stats_enabled", 6143 .data = &bpf_stats_enabled_key.key, 6144 .mode = 0644, 6145 .proc_handler = bpf_stats_handler, 6146 }, 6147 }; 6148 6149 static int __init bpf_syscall_sysctl_init(void) 6150 { 6151 register_sysctl_init("kernel", bpf_syscall_table); 6152 return 0; 6153 } 6154 late_initcall(bpf_syscall_sysctl_init); 6155 #endif /* CONFIG_SYSCTL */ 6156