1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 */ 4 #include <crypto/sha2.h> 5 #include <linux/bpf.h> 6 #include <linux/bpf-cgroup.h> 7 #include <linux/bpf_trace.h> 8 #include <linux/bpf_lirc.h> 9 #include <linux/bpf_verifier.h> 10 #include <linux/bsearch.h> 11 #include <linux/btf.h> 12 #include <linux/syscalls.h> 13 #include <linux/slab.h> 14 #include <linux/sched/signal.h> 15 #include <linux/vmalloc.h> 16 #include <linux/mmzone.h> 17 #include <linux/anon_inodes.h> 18 #include <linux/fdtable.h> 19 #include <linux/file.h> 20 #include <linux/fs.h> 21 #include <linux/license.h> 22 #include <linux/filter.h> 23 #include <linux/kernel.h> 24 #include <linux/idr.h> 25 #include <linux/cred.h> 26 #include <linux/timekeeping.h> 27 #include <linux/ctype.h> 28 #include <linux/nospec.h> 29 #include <linux/audit.h> 30 #include <uapi/linux/btf.h> 31 #include <linux/pgtable.h> 32 #include <linux/bpf_lsm.h> 33 #include <linux/poll.h> 34 #include <linux/sort.h> 35 #include <linux/bpf-netns.h> 36 #include <linux/rcupdate_trace.h> 37 #include <linux/memcontrol.h> 38 #include <linux/trace_events.h> 39 #include <linux/tracepoint.h> 40 #include <linux/overflow.h> 41 #include <linux/cookie.h> 42 #include <linux/verification.h> 43 44 #include <net/netfilter/nf_bpf_link.h> 45 #include <net/netkit.h> 46 #include <net/tcx.h> 47 48 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ 49 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ 50 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 51 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY) 52 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) 53 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \ 54 IS_FD_HASH(map)) 55 56 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) 57 58 DEFINE_PER_CPU(int, bpf_prog_active); 59 DEFINE_COOKIE(bpf_map_cookie); 60 static DEFINE_IDR(prog_idr); 61 static DEFINE_SPINLOCK(prog_idr_lock); 62 static DEFINE_IDR(map_idr); 63 static DEFINE_SPINLOCK(map_idr_lock); 64 static DEFINE_IDR(link_idr); 65 static DEFINE_SPINLOCK(link_idr_lock); 66 67 int sysctl_unprivileged_bpf_disabled __read_mostly = 68 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0; 69 70 static const struct bpf_map_ops * const bpf_map_types[] = { 71 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 72 #define BPF_MAP_TYPE(_id, _ops) \ 73 [_id] = &_ops, 74 #define BPF_LINK_TYPE(_id, _name) 75 #include <linux/bpf_types.h> 76 #undef BPF_PROG_TYPE 77 #undef BPF_MAP_TYPE 78 #undef BPF_LINK_TYPE 79 }; 80 81 /* 82 * If we're handed a bigger struct than we know of, ensure all the unknown bits 83 * are 0 - i.e. new user-space does not rely on any kernel feature extensions 84 * we don't know about yet. 85 * 86 * There is a ToCToU between this function call and the following 87 * copy_from_user() call. However, this is not a concern since this function is 88 * meant to be a future-proofing of bits. 89 */ 90 int bpf_check_uarg_tail_zero(bpfptr_t uaddr, 91 size_t expected_size, 92 size_t actual_size) 93 { 94 int res; 95 96 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ 97 return -E2BIG; 98 99 if (actual_size <= expected_size) 100 return 0; 101 102 if (uaddr.is_kernel) 103 res = memchr_inv(uaddr.kernel + expected_size, 0, 104 actual_size - expected_size) == NULL; 105 else 106 res = check_zeroed_user(uaddr.user + expected_size, 107 actual_size - expected_size); 108 if (res < 0) 109 return res; 110 return res ? 0 : -E2BIG; 111 } 112 113 const struct bpf_map_ops bpf_map_offload_ops = { 114 .map_meta_equal = bpf_map_meta_equal, 115 .map_alloc = bpf_map_offload_map_alloc, 116 .map_free = bpf_map_offload_map_free, 117 .map_check_btf = map_check_no_btf, 118 .map_mem_usage = bpf_map_offload_map_mem_usage, 119 }; 120 121 static void bpf_map_write_active_inc(struct bpf_map *map) 122 { 123 atomic64_inc(&map->writecnt); 124 } 125 126 static void bpf_map_write_active_dec(struct bpf_map *map) 127 { 128 atomic64_dec(&map->writecnt); 129 } 130 131 bool bpf_map_write_active(const struct bpf_map *map) 132 { 133 return atomic64_read(&map->writecnt) != 0; 134 } 135 136 static u32 bpf_map_value_size(const struct bpf_map *map) 137 { 138 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 139 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || 140 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY || 141 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) 142 return round_up(map->value_size, 8) * num_possible_cpus(); 143 else if (IS_FD_MAP(map)) 144 return sizeof(u32); 145 else 146 return map->value_size; 147 } 148 149 static void maybe_wait_bpf_programs(struct bpf_map *map) 150 { 151 /* Wait for any running non-sleepable BPF programs to complete so that 152 * userspace, when we return to it, knows that all non-sleepable 153 * programs that could be running use the new map value. For sleepable 154 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait 155 * for the completions of these programs, but considering the waiting 156 * time can be very long and userspace may think it will hang forever, 157 * so don't handle sleepable BPF programs now. 158 */ 159 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS || 160 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) 161 synchronize_rcu(); 162 } 163 164 static void unpin_uptr_kaddr(void *kaddr) 165 { 166 if (kaddr) 167 unpin_user_page(virt_to_page(kaddr)); 168 } 169 170 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj) 171 { 172 const struct btf_field *field; 173 void **uptr_addr; 174 int i; 175 176 for (i = 0, field = rec->fields; i < cnt; i++, field++) { 177 if (field->type != BPF_UPTR) 178 continue; 179 180 uptr_addr = obj + field->offset; 181 unpin_uptr_kaddr(*uptr_addr); 182 } 183 } 184 185 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj) 186 { 187 if (!btf_record_has_field(rec, BPF_UPTR)) 188 return; 189 190 __bpf_obj_unpin_uptrs(rec, rec->cnt, obj); 191 } 192 193 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj) 194 { 195 const struct btf_field *field; 196 const struct btf_type *t; 197 unsigned long start, end; 198 struct page *page; 199 void **uptr_addr; 200 int i, err; 201 202 if (!btf_record_has_field(rec, BPF_UPTR)) 203 return 0; 204 205 for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) { 206 if (field->type != BPF_UPTR) 207 continue; 208 209 uptr_addr = obj + field->offset; 210 start = *(unsigned long *)uptr_addr; 211 if (!start) 212 continue; 213 214 t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id); 215 /* t->size was checked for zero before */ 216 if (check_add_overflow(start, t->size - 1, &end)) { 217 err = -EFAULT; 218 goto unpin_all; 219 } 220 221 /* The uptr's struct cannot span across two pages */ 222 if ((start & PAGE_MASK) != (end & PAGE_MASK)) { 223 err = -EOPNOTSUPP; 224 goto unpin_all; 225 } 226 227 err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page); 228 if (err != 1) 229 goto unpin_all; 230 231 if (PageHighMem(page)) { 232 err = -EOPNOTSUPP; 233 unpin_user_page(page); 234 goto unpin_all; 235 } 236 237 *uptr_addr = page_address(page) + offset_in_page(start); 238 } 239 240 return 0; 241 242 unpin_all: 243 __bpf_obj_unpin_uptrs(rec, i, obj); 244 return err; 245 } 246 247 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file, 248 void *key, void *value, __u64 flags) 249 { 250 int err; 251 252 /* Need to create a kthread, thus must support schedule */ 253 if (bpf_map_is_offloaded(map)) { 254 return bpf_map_offload_update_elem(map, key, value, flags); 255 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP || 256 map->map_type == BPF_MAP_TYPE_ARENA || 257 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 258 return map->ops->map_update_elem(map, key, value, flags); 259 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH || 260 map->map_type == BPF_MAP_TYPE_SOCKMAP) { 261 return sock_map_update_elem_sys(map, key, value, flags); 262 } else if (IS_FD_PROG_ARRAY(map)) { 263 return bpf_fd_array_map_update_elem(map, map_file, key, value, 264 flags); 265 } 266 267 bpf_disable_instrumentation(); 268 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 269 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 270 err = bpf_percpu_hash_update(map, key, value, flags); 271 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 272 err = bpf_percpu_array_update(map, key, value, flags); 273 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 274 err = bpf_percpu_cgroup_storage_update(map, key, value, 275 flags); 276 } else if (IS_FD_ARRAY(map)) { 277 err = bpf_fd_array_map_update_elem(map, map_file, key, value, 278 flags); 279 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { 280 err = bpf_fd_htab_map_update_elem(map, map_file, key, value, 281 flags); 282 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 283 /* rcu_read_lock() is not needed */ 284 err = bpf_fd_reuseport_array_update_elem(map, key, value, 285 flags); 286 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 287 map->map_type == BPF_MAP_TYPE_STACK || 288 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 289 err = map->ops->map_push_elem(map, value, flags); 290 } else { 291 err = bpf_obj_pin_uptrs(map->record, value); 292 if (!err) { 293 rcu_read_lock(); 294 err = map->ops->map_update_elem(map, key, value, flags); 295 rcu_read_unlock(); 296 if (err) 297 bpf_obj_unpin_uptrs(map->record, value); 298 } 299 } 300 bpf_enable_instrumentation(); 301 302 return err; 303 } 304 305 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, 306 __u64 flags) 307 { 308 void *ptr; 309 int err; 310 311 if (bpf_map_is_offloaded(map)) 312 return bpf_map_offload_lookup_elem(map, key, value); 313 314 bpf_disable_instrumentation(); 315 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 316 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 317 err = bpf_percpu_hash_copy(map, key, value); 318 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 319 err = bpf_percpu_array_copy(map, key, value); 320 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { 321 err = bpf_percpu_cgroup_storage_copy(map, key, value); 322 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { 323 err = bpf_stackmap_copy(map, key, value); 324 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { 325 err = bpf_fd_array_map_lookup_elem(map, key, value); 326 } else if (IS_FD_HASH(map)) { 327 err = bpf_fd_htab_map_lookup_elem(map, key, value); 328 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) { 329 err = bpf_fd_reuseport_array_lookup_elem(map, key, value); 330 } else if (map->map_type == BPF_MAP_TYPE_QUEUE || 331 map->map_type == BPF_MAP_TYPE_STACK || 332 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 333 err = map->ops->map_peek_elem(map, value); 334 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 335 /* struct_ops map requires directly updating "value" */ 336 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value); 337 } else { 338 rcu_read_lock(); 339 if (map->ops->map_lookup_elem_sys_only) 340 ptr = map->ops->map_lookup_elem_sys_only(map, key); 341 else 342 ptr = map->ops->map_lookup_elem(map, key); 343 if (IS_ERR(ptr)) { 344 err = PTR_ERR(ptr); 345 } else if (!ptr) { 346 err = -ENOENT; 347 } else { 348 err = 0; 349 if (flags & BPF_F_LOCK) 350 /* lock 'ptr' and copy everything but lock */ 351 copy_map_value_locked(map, value, ptr, true); 352 else 353 copy_map_value(map, value, ptr); 354 /* mask lock and timer, since value wasn't zero inited */ 355 check_and_init_map_value(map, value); 356 } 357 rcu_read_unlock(); 358 } 359 360 bpf_enable_instrumentation(); 361 362 return err; 363 } 364 365 /* Please, do not use this function outside from the map creation path 366 * (e.g. in map update path) without taking care of setting the active 367 * memory cgroup (see at bpf_map_kmalloc_node() for example). 368 */ 369 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) 370 { 371 /* We really just want to fail instead of triggering OOM killer 372 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, 373 * which is used for lower order allocation requests. 374 * 375 * It has been observed that higher order allocation requests done by 376 * vmalloc with __GFP_NORETRY being set might fail due to not trying 377 * to reclaim memory from the page cache, thus we set 378 * __GFP_RETRY_MAYFAIL to avoid such situations. 379 */ 380 381 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO); 382 unsigned int flags = 0; 383 unsigned long align = 1; 384 void *area; 385 386 if (size >= SIZE_MAX) 387 return NULL; 388 389 /* kmalloc()'ed memory can't be mmap()'ed */ 390 if (mmapable) { 391 BUG_ON(!PAGE_ALIGNED(size)); 392 align = SHMLBA; 393 flags = VM_USERMAP; 394 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { 395 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY, 396 numa_node); 397 if (area != NULL) 398 return area; 399 } 400 401 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, 402 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL, 403 flags, numa_node, __builtin_return_address(0)); 404 } 405 406 void *bpf_map_area_alloc(u64 size, int numa_node) 407 { 408 return __bpf_map_area_alloc(size, numa_node, false); 409 } 410 411 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node) 412 { 413 return __bpf_map_area_alloc(size, numa_node, true); 414 } 415 416 void bpf_map_area_free(void *area) 417 { 418 kvfree(area); 419 } 420 421 static u32 bpf_map_flags_retain_permanent(u32 flags) 422 { 423 /* Some map creation flags are not tied to the map object but 424 * rather to the map fd instead, so they have no meaning upon 425 * map object inspection since multiple file descriptors with 426 * different (access) properties can exist here. Thus, given 427 * this has zero meaning for the map itself, lets clear these 428 * from here. 429 */ 430 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY); 431 } 432 433 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) 434 { 435 map->map_type = attr->map_type; 436 map->key_size = attr->key_size; 437 map->value_size = attr->value_size; 438 map->max_entries = attr->max_entries; 439 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags); 440 map->numa_node = bpf_map_attr_numa_node(attr); 441 map->map_extra = attr->map_extra; 442 } 443 444 static int bpf_map_alloc_id(struct bpf_map *map) 445 { 446 int id; 447 448 idr_preload(GFP_KERNEL); 449 spin_lock_bh(&map_idr_lock); 450 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); 451 if (id > 0) 452 map->id = id; 453 spin_unlock_bh(&map_idr_lock); 454 idr_preload_end(); 455 456 if (WARN_ON_ONCE(!id)) 457 return -ENOSPC; 458 459 return id > 0 ? 0 : id; 460 } 461 462 void bpf_map_free_id(struct bpf_map *map) 463 { 464 unsigned long flags; 465 466 /* Offloaded maps are removed from the IDR store when their device 467 * disappears - even if someone holds an fd to them they are unusable, 468 * the memory is gone, all ops will fail; they are simply waiting for 469 * refcnt to drop to be freed. 470 */ 471 if (!map->id) 472 return; 473 474 spin_lock_irqsave(&map_idr_lock, flags); 475 476 idr_remove(&map_idr, map->id); 477 map->id = 0; 478 479 spin_unlock_irqrestore(&map_idr_lock, flags); 480 } 481 482 #ifdef CONFIG_MEMCG 483 static void bpf_map_save_memcg(struct bpf_map *map) 484 { 485 /* Currently if a map is created by a process belonging to the root 486 * memory cgroup, get_obj_cgroup_from_current() will return NULL. 487 * So we have to check map->objcg for being NULL each time it's 488 * being used. 489 */ 490 if (memcg_bpf_enabled()) 491 map->objcg = get_obj_cgroup_from_current(); 492 } 493 494 static void bpf_map_release_memcg(struct bpf_map *map) 495 { 496 if (map->objcg) 497 obj_cgroup_put(map->objcg); 498 } 499 500 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) 501 { 502 if (map->objcg) 503 return get_mem_cgroup_from_objcg(map->objcg); 504 505 return root_mem_cgroup; 506 } 507 508 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, 509 int node) 510 { 511 struct mem_cgroup *memcg, *old_memcg; 512 void *ptr; 513 514 memcg = bpf_map_get_memcg(map); 515 old_memcg = set_active_memcg(memcg); 516 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); 517 set_active_memcg(old_memcg); 518 mem_cgroup_put(memcg); 519 520 return ptr; 521 } 522 523 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) 524 { 525 struct mem_cgroup *memcg, *old_memcg; 526 void *ptr; 527 528 memcg = bpf_map_get_memcg(map); 529 old_memcg = set_active_memcg(memcg); 530 ptr = kzalloc(size, flags | __GFP_ACCOUNT); 531 set_active_memcg(old_memcg); 532 mem_cgroup_put(memcg); 533 534 return ptr; 535 } 536 537 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, 538 gfp_t flags) 539 { 540 struct mem_cgroup *memcg, *old_memcg; 541 void *ptr; 542 543 memcg = bpf_map_get_memcg(map); 544 old_memcg = set_active_memcg(memcg); 545 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); 546 set_active_memcg(old_memcg); 547 mem_cgroup_put(memcg); 548 549 return ptr; 550 } 551 552 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, 553 size_t align, gfp_t flags) 554 { 555 struct mem_cgroup *memcg, *old_memcg; 556 void __percpu *ptr; 557 558 memcg = bpf_map_get_memcg(map); 559 old_memcg = set_active_memcg(memcg); 560 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); 561 set_active_memcg(old_memcg); 562 mem_cgroup_put(memcg); 563 564 return ptr; 565 } 566 567 #else 568 static void bpf_map_save_memcg(struct bpf_map *map) 569 { 570 } 571 572 static void bpf_map_release_memcg(struct bpf_map *map) 573 { 574 } 575 #endif 576 577 static bool can_alloc_pages(void) 578 { 579 return preempt_count() == 0 && !irqs_disabled() && 580 !IS_ENABLED(CONFIG_PREEMPT_RT); 581 } 582 583 static struct page *__bpf_alloc_page(int nid) 584 { 585 if (!can_alloc_pages()) 586 return alloc_pages_nolock(nid, 0); 587 588 return alloc_pages_node(nid, 589 GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT 590 | __GFP_NOWARN, 591 0); 592 } 593 594 int bpf_map_alloc_pages(const struct bpf_map *map, int nid, 595 unsigned long nr_pages, struct page **pages) 596 { 597 unsigned long i, j; 598 struct page *pg; 599 int ret = 0; 600 #ifdef CONFIG_MEMCG 601 struct mem_cgroup *memcg, *old_memcg; 602 603 memcg = bpf_map_get_memcg(map); 604 old_memcg = set_active_memcg(memcg); 605 #endif 606 for (i = 0; i < nr_pages; i++) { 607 pg = __bpf_alloc_page(nid); 608 609 if (pg) { 610 pages[i] = pg; 611 continue; 612 } 613 for (j = 0; j < i; j++) 614 free_pages_nolock(pages[j], 0); 615 ret = -ENOMEM; 616 break; 617 } 618 619 #ifdef CONFIG_MEMCG 620 set_active_memcg(old_memcg); 621 mem_cgroup_put(memcg); 622 #endif 623 return ret; 624 } 625 626 627 static int btf_field_cmp(const void *a, const void *b) 628 { 629 const struct btf_field *f1 = a, *f2 = b; 630 631 if (f1->offset < f2->offset) 632 return -1; 633 else if (f1->offset > f2->offset) 634 return 1; 635 return 0; 636 } 637 638 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset, 639 u32 field_mask) 640 { 641 struct btf_field *field; 642 643 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask)) 644 return NULL; 645 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp); 646 if (!field || !(field->type & field_mask)) 647 return NULL; 648 return field; 649 } 650 651 void btf_record_free(struct btf_record *rec) 652 { 653 int i; 654 655 if (IS_ERR_OR_NULL(rec)) 656 return; 657 for (i = 0; i < rec->cnt; i++) { 658 switch (rec->fields[i].type) { 659 case BPF_KPTR_UNREF: 660 case BPF_KPTR_REF: 661 case BPF_KPTR_PERCPU: 662 case BPF_UPTR: 663 if (rec->fields[i].kptr.module) 664 module_put(rec->fields[i].kptr.module); 665 if (btf_is_kernel(rec->fields[i].kptr.btf)) 666 btf_put(rec->fields[i].kptr.btf); 667 break; 668 case BPF_LIST_HEAD: 669 case BPF_LIST_NODE: 670 case BPF_RB_ROOT: 671 case BPF_RB_NODE: 672 case BPF_SPIN_LOCK: 673 case BPF_RES_SPIN_LOCK: 674 case BPF_TIMER: 675 case BPF_REFCOUNT: 676 case BPF_WORKQUEUE: 677 case BPF_TASK_WORK: 678 /* Nothing to release */ 679 break; 680 default: 681 WARN_ON_ONCE(1); 682 continue; 683 } 684 } 685 kfree(rec); 686 } 687 688 void bpf_map_free_record(struct bpf_map *map) 689 { 690 btf_record_free(map->record); 691 map->record = NULL; 692 } 693 694 struct btf_record *btf_record_dup(const struct btf_record *rec) 695 { 696 const struct btf_field *fields; 697 struct btf_record *new_rec; 698 int ret, size, i; 699 700 if (IS_ERR_OR_NULL(rec)) 701 return NULL; 702 size = struct_size(rec, fields, rec->cnt); 703 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN); 704 if (!new_rec) 705 return ERR_PTR(-ENOMEM); 706 /* Do a deep copy of the btf_record */ 707 fields = rec->fields; 708 new_rec->cnt = 0; 709 for (i = 0; i < rec->cnt; i++) { 710 switch (fields[i].type) { 711 case BPF_KPTR_UNREF: 712 case BPF_KPTR_REF: 713 case BPF_KPTR_PERCPU: 714 case BPF_UPTR: 715 if (btf_is_kernel(fields[i].kptr.btf)) 716 btf_get(fields[i].kptr.btf); 717 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { 718 ret = -ENXIO; 719 goto free; 720 } 721 break; 722 case BPF_LIST_HEAD: 723 case BPF_LIST_NODE: 724 case BPF_RB_ROOT: 725 case BPF_RB_NODE: 726 case BPF_SPIN_LOCK: 727 case BPF_RES_SPIN_LOCK: 728 case BPF_TIMER: 729 case BPF_REFCOUNT: 730 case BPF_WORKQUEUE: 731 case BPF_TASK_WORK: 732 /* Nothing to acquire */ 733 break; 734 default: 735 ret = -EFAULT; 736 WARN_ON_ONCE(1); 737 goto free; 738 } 739 new_rec->cnt++; 740 } 741 return new_rec; 742 free: 743 btf_record_free(new_rec); 744 return ERR_PTR(ret); 745 } 746 747 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b) 748 { 749 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b); 750 int size; 751 752 if (!a_has_fields && !b_has_fields) 753 return true; 754 if (a_has_fields != b_has_fields) 755 return false; 756 if (rec_a->cnt != rec_b->cnt) 757 return false; 758 size = struct_size(rec_a, fields, rec_a->cnt); 759 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused 760 * members are zeroed out. So memcmp is safe to do without worrying 761 * about padding/unused fields. 762 * 763 * While spin_lock, timer, and kptr have no relation to map BTF, 764 * list_head metadata is specific to map BTF, the btf and value_rec 765 * members in particular. btf is the map BTF, while value_rec points to 766 * btf_record in that map BTF. 767 * 768 * So while by default, we don't rely on the map BTF (which the records 769 * were parsed from) matching for both records, which is not backwards 770 * compatible, in case list_head is part of it, we implicitly rely on 771 * that by way of depending on memcmp succeeding for it. 772 */ 773 return !memcmp(rec_a, rec_b, size); 774 } 775 776 void bpf_obj_free_timer(const struct btf_record *rec, void *obj) 777 { 778 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER))) 779 return; 780 bpf_timer_cancel_and_free(obj + rec->timer_off); 781 } 782 783 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj) 784 { 785 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE))) 786 return; 787 bpf_wq_cancel_and_free(obj + rec->wq_off); 788 } 789 790 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj) 791 { 792 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK))) 793 return; 794 bpf_task_work_cancel_and_free(obj + rec->task_work_off); 795 } 796 797 void bpf_obj_free_fields(const struct btf_record *rec, void *obj) 798 { 799 const struct btf_field *fields; 800 int i; 801 802 if (IS_ERR_OR_NULL(rec)) 803 return; 804 fields = rec->fields; 805 for (i = 0; i < rec->cnt; i++) { 806 struct btf_struct_meta *pointee_struct_meta; 807 const struct btf_field *field = &fields[i]; 808 void *field_ptr = obj + field->offset; 809 void *xchgd_field; 810 811 switch (fields[i].type) { 812 case BPF_SPIN_LOCK: 813 case BPF_RES_SPIN_LOCK: 814 break; 815 case BPF_TIMER: 816 bpf_timer_cancel_and_free(field_ptr); 817 break; 818 case BPF_WORKQUEUE: 819 bpf_wq_cancel_and_free(field_ptr); 820 break; 821 case BPF_TASK_WORK: 822 bpf_task_work_cancel_and_free(field_ptr); 823 break; 824 case BPF_KPTR_UNREF: 825 WRITE_ONCE(*(u64 *)field_ptr, 0); 826 break; 827 case BPF_KPTR_REF: 828 case BPF_KPTR_PERCPU: 829 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); 830 if (!xchgd_field) 831 break; 832 833 if (!btf_is_kernel(field->kptr.btf)) { 834 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf, 835 field->kptr.btf_id); 836 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ? 837 pointee_struct_meta->record : NULL, 838 fields[i].type == BPF_KPTR_PERCPU); 839 } else { 840 field->kptr.dtor(xchgd_field); 841 } 842 break; 843 case BPF_UPTR: 844 /* The caller ensured that no one is using the uptr */ 845 unpin_uptr_kaddr(*(void **)field_ptr); 846 break; 847 case BPF_LIST_HEAD: 848 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 849 continue; 850 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); 851 break; 852 case BPF_RB_ROOT: 853 if (WARN_ON_ONCE(rec->spin_lock_off < 0)) 854 continue; 855 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); 856 break; 857 case BPF_LIST_NODE: 858 case BPF_RB_NODE: 859 case BPF_REFCOUNT: 860 break; 861 default: 862 WARN_ON_ONCE(1); 863 continue; 864 } 865 } 866 } 867 868 static void bpf_map_free(struct bpf_map *map) 869 { 870 struct btf_record *rec = map->record; 871 struct btf *btf = map->btf; 872 873 /* implementation dependent freeing. Disabling migration to simplify 874 * the free of values or special fields allocated from bpf memory 875 * allocator. 876 */ 877 kfree(map->excl_prog_sha); 878 migrate_disable(); 879 map->ops->map_free(map); 880 migrate_enable(); 881 882 /* Delay freeing of btf_record for maps, as map_free 883 * callback usually needs access to them. It is better to do it here 884 * than require each callback to do the free itself manually. 885 * 886 * Note that the btf_record stashed in map->inner_map_meta->record was 887 * already freed using the map_free callback for map in map case which 888 * eventually calls bpf_map_free_meta, since inner_map_meta is only a 889 * template bpf_map struct used during verification. 890 */ 891 btf_record_free(rec); 892 /* Delay freeing of btf for maps, as map_free callback may need 893 * struct_meta info which will be freed with btf_put(). 894 */ 895 btf_put(btf); 896 } 897 898 /* called from workqueue */ 899 static void bpf_map_free_deferred(struct work_struct *work) 900 { 901 struct bpf_map *map = container_of(work, struct bpf_map, work); 902 903 security_bpf_map_free(map); 904 bpf_map_release_memcg(map); 905 bpf_map_owner_free(map); 906 bpf_map_free(map); 907 } 908 909 static void bpf_map_put_uref(struct bpf_map *map) 910 { 911 if (atomic64_dec_and_test(&map->usercnt)) { 912 if (map->ops->map_release_uref) 913 map->ops->map_release_uref(map); 914 } 915 } 916 917 static void bpf_map_free_in_work(struct bpf_map *map) 918 { 919 INIT_WORK(&map->work, bpf_map_free_deferred); 920 /* Avoid spawning kworkers, since they all might contend 921 * for the same mutex like slab_mutex. 922 */ 923 queue_work(system_dfl_wq, &map->work); 924 } 925 926 static void bpf_map_free_rcu_gp(struct rcu_head *rcu) 927 { 928 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu)); 929 } 930 931 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu) 932 { 933 if (rcu_trace_implies_rcu_gp()) 934 bpf_map_free_rcu_gp(rcu); 935 else 936 call_rcu(rcu, bpf_map_free_rcu_gp); 937 } 938 939 /* decrement map refcnt and schedule it for freeing via workqueue 940 * (underlying map implementation ops->map_free() might sleep) 941 */ 942 void bpf_map_put(struct bpf_map *map) 943 { 944 if (atomic64_dec_and_test(&map->refcnt)) { 945 /* bpf_map_free_id() must be called first */ 946 bpf_map_free_id(map); 947 948 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt)); 949 if (READ_ONCE(map->free_after_mult_rcu_gp)) 950 call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp); 951 else if (READ_ONCE(map->free_after_rcu_gp)) 952 call_rcu(&map->rcu, bpf_map_free_rcu_gp); 953 else 954 bpf_map_free_in_work(map); 955 } 956 } 957 EXPORT_SYMBOL_GPL(bpf_map_put); 958 959 void bpf_map_put_with_uref(struct bpf_map *map) 960 { 961 bpf_map_put_uref(map); 962 bpf_map_put(map); 963 } 964 965 static int bpf_map_release(struct inode *inode, struct file *filp) 966 { 967 struct bpf_map *map = filp->private_data; 968 969 if (map->ops->map_release) 970 map->ops->map_release(map, filp); 971 972 bpf_map_put_with_uref(map); 973 return 0; 974 } 975 976 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 977 { 978 fmode_t mode = fd_file(f)->f_mode; 979 980 /* Our file permissions may have been overridden by global 981 * map permissions facing syscall side. 982 */ 983 if (READ_ONCE(map->frozen)) 984 mode &= ~FMODE_CAN_WRITE; 985 return mode; 986 } 987 988 #ifdef CONFIG_PROC_FS 989 /* Show the memory usage of a bpf map */ 990 static u64 bpf_map_memory_usage(const struct bpf_map *map) 991 { 992 return map->ops->map_mem_usage(map); 993 } 994 995 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 996 { 997 struct bpf_map *map = filp->private_data; 998 u32 type = 0, jited = 0; 999 1000 spin_lock(&map->owner_lock); 1001 if (map->owner) { 1002 type = map->owner->type; 1003 jited = map->owner->jited; 1004 } 1005 spin_unlock(&map->owner_lock); 1006 1007 seq_printf(m, 1008 "map_type:\t%u\n" 1009 "key_size:\t%u\n" 1010 "value_size:\t%u\n" 1011 "max_entries:\t%u\n" 1012 "map_flags:\t%#x\n" 1013 "map_extra:\t%#llx\n" 1014 "memlock:\t%llu\n" 1015 "map_id:\t%u\n" 1016 "frozen:\t%u\n", 1017 map->map_type, 1018 map->key_size, 1019 map->value_size, 1020 map->max_entries, 1021 map->map_flags, 1022 (unsigned long long)map->map_extra, 1023 bpf_map_memory_usage(map), 1024 map->id, 1025 READ_ONCE(map->frozen)); 1026 if (type) { 1027 seq_printf(m, "owner_prog_type:\t%u\n", type); 1028 seq_printf(m, "owner_jited:\t%u\n", jited); 1029 } 1030 } 1031 #endif 1032 1033 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, 1034 loff_t *ppos) 1035 { 1036 /* We need this handler such that alloc_file() enables 1037 * f_mode with FMODE_CAN_READ. 1038 */ 1039 return -EINVAL; 1040 } 1041 1042 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, 1043 size_t siz, loff_t *ppos) 1044 { 1045 /* We need this handler such that alloc_file() enables 1046 * f_mode with FMODE_CAN_WRITE. 1047 */ 1048 return -EINVAL; 1049 } 1050 1051 /* called for any extra memory-mapped regions (except initial) */ 1052 static void bpf_map_mmap_open(struct vm_area_struct *vma) 1053 { 1054 struct bpf_map *map = vma->vm_file->private_data; 1055 1056 if (vma->vm_flags & VM_MAYWRITE) 1057 bpf_map_write_active_inc(map); 1058 } 1059 1060 /* called for all unmapped memory region (including initial) */ 1061 static void bpf_map_mmap_close(struct vm_area_struct *vma) 1062 { 1063 struct bpf_map *map = vma->vm_file->private_data; 1064 1065 if (vma->vm_flags & VM_MAYWRITE) 1066 bpf_map_write_active_dec(map); 1067 } 1068 1069 static const struct vm_operations_struct bpf_map_default_vmops = { 1070 .open = bpf_map_mmap_open, 1071 .close = bpf_map_mmap_close, 1072 }; 1073 1074 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma) 1075 { 1076 struct bpf_map *map = filp->private_data; 1077 int err = 0; 1078 1079 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record)) 1080 return -ENOTSUPP; 1081 1082 if (!(vma->vm_flags & VM_SHARED)) 1083 return -EINVAL; 1084 1085 mutex_lock(&map->freeze_mutex); 1086 1087 if (vma->vm_flags & VM_WRITE) { 1088 if (map->frozen) { 1089 err = -EPERM; 1090 goto out; 1091 } 1092 /* map is meant to be read-only, so do not allow mapping as 1093 * writable, because it's possible to leak a writable page 1094 * reference and allows user-space to still modify it after 1095 * freezing, while verifier will assume contents do not change 1096 */ 1097 if (map->map_flags & BPF_F_RDONLY_PROG) { 1098 err = -EACCES; 1099 goto out; 1100 } 1101 bpf_map_write_active_inc(map); 1102 } 1103 out: 1104 mutex_unlock(&map->freeze_mutex); 1105 if (err) 1106 return err; 1107 1108 /* set default open/close callbacks */ 1109 vma->vm_ops = &bpf_map_default_vmops; 1110 vma->vm_private_data = map; 1111 vm_flags_clear(vma, VM_MAYEXEC); 1112 /* If mapping is read-only, then disallow potentially re-mapping with 1113 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing 1114 * means that as far as BPF map's memory-mapped VMAs are concerned, 1115 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set, 1116 * both should be set, so we can forget about VM_MAYWRITE and always 1117 * check just VM_WRITE 1118 */ 1119 if (!(vma->vm_flags & VM_WRITE)) 1120 vm_flags_clear(vma, VM_MAYWRITE); 1121 1122 err = map->ops->map_mmap(map, vma); 1123 if (err) { 1124 if (vma->vm_flags & VM_WRITE) 1125 bpf_map_write_active_dec(map); 1126 } 1127 1128 return err; 1129 } 1130 1131 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts) 1132 { 1133 struct bpf_map *map = filp->private_data; 1134 1135 if (map->ops->map_poll) 1136 return map->ops->map_poll(map, filp, pts); 1137 1138 return EPOLLERR; 1139 } 1140 1141 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr, 1142 unsigned long len, unsigned long pgoff, 1143 unsigned long flags) 1144 { 1145 struct bpf_map *map = filp->private_data; 1146 1147 if (map->ops->map_get_unmapped_area) 1148 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags); 1149 #ifdef CONFIG_MMU 1150 return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags); 1151 #else 1152 return addr; 1153 #endif 1154 } 1155 1156 const struct file_operations bpf_map_fops = { 1157 #ifdef CONFIG_PROC_FS 1158 .show_fdinfo = bpf_map_show_fdinfo, 1159 #endif 1160 .release = bpf_map_release, 1161 .read = bpf_dummy_read, 1162 .write = bpf_dummy_write, 1163 .mmap = bpf_map_mmap, 1164 .poll = bpf_map_poll, 1165 .get_unmapped_area = bpf_get_unmapped_area, 1166 }; 1167 1168 int bpf_map_new_fd(struct bpf_map *map, int flags) 1169 { 1170 int ret; 1171 1172 ret = security_bpf_map(map, OPEN_FMODE(flags)); 1173 if (ret < 0) 1174 return ret; 1175 1176 return anon_inode_getfd("bpf-map", &bpf_map_fops, map, 1177 flags | O_CLOEXEC); 1178 } 1179 1180 int bpf_get_file_flag(int flags) 1181 { 1182 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) 1183 return -EINVAL; 1184 if (flags & BPF_F_RDONLY) 1185 return O_RDONLY; 1186 if (flags & BPF_F_WRONLY) 1187 return O_WRONLY; 1188 return O_RDWR; 1189 } 1190 1191 /* helper macro to check that unused fields 'union bpf_attr' are zero */ 1192 #define CHECK_ATTR(CMD) \ 1193 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ 1194 sizeof(attr->CMD##_LAST_FIELD), 0, \ 1195 sizeof(*attr) - \ 1196 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ 1197 sizeof(attr->CMD##_LAST_FIELD)) != NULL 1198 1199 /* dst and src must have at least "size" number of bytes. 1200 * Return strlen on success and < 0 on error. 1201 */ 1202 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size) 1203 { 1204 const char *end = src + size; 1205 const char *orig_src = src; 1206 1207 memset(dst, 0, size); 1208 /* Copy all isalnum(), '_' and '.' chars. */ 1209 while (src < end && *src) { 1210 if (!isalnum(*src) && 1211 *src != '_' && *src != '.') 1212 return -EINVAL; 1213 *dst++ = *src++; 1214 } 1215 1216 /* No '\0' found in "size" number of bytes */ 1217 if (src == end) 1218 return -EINVAL; 1219 1220 return src - orig_src; 1221 } 1222 1223 int map_check_no_btf(const struct bpf_map *map, 1224 const struct btf *btf, 1225 const struct btf_type *key_type, 1226 const struct btf_type *value_type) 1227 { 1228 return -ENOTSUPP; 1229 } 1230 1231 static int map_check_btf(struct bpf_map *map, struct bpf_token *token, 1232 const struct btf *btf, u32 btf_key_id, u32 btf_value_id) 1233 { 1234 const struct btf_type *key_type, *value_type; 1235 u32 key_size, value_size; 1236 int ret = 0; 1237 1238 /* Some maps allow key to be unspecified. */ 1239 if (btf_key_id) { 1240 key_type = btf_type_id_size(btf, &btf_key_id, &key_size); 1241 if (!key_type || key_size != map->key_size) 1242 return -EINVAL; 1243 } else { 1244 key_type = btf_type_by_id(btf, 0); 1245 if (!map->ops->map_check_btf) 1246 return -EINVAL; 1247 } 1248 1249 value_type = btf_type_id_size(btf, &btf_value_id, &value_size); 1250 if (!value_type || value_size != map->value_size) 1251 return -EINVAL; 1252 1253 map->record = btf_parse_fields(btf, value_type, 1254 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | 1255 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR | 1256 BPF_TASK_WORK, 1257 map->value_size); 1258 if (!IS_ERR_OR_NULL(map->record)) { 1259 int i; 1260 1261 if (!bpf_token_capable(token, CAP_BPF)) { 1262 ret = -EPERM; 1263 goto free_map_tab; 1264 } 1265 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) { 1266 ret = -EACCES; 1267 goto free_map_tab; 1268 } 1269 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) { 1270 switch (map->record->field_mask & (1 << i)) { 1271 case 0: 1272 continue; 1273 case BPF_SPIN_LOCK: 1274 case BPF_RES_SPIN_LOCK: 1275 if (map->map_type != BPF_MAP_TYPE_HASH && 1276 map->map_type != BPF_MAP_TYPE_ARRAY && 1277 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE && 1278 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1279 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1280 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1281 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1282 ret = -EOPNOTSUPP; 1283 goto free_map_tab; 1284 } 1285 break; 1286 case BPF_TIMER: 1287 case BPF_WORKQUEUE: 1288 case BPF_TASK_WORK: 1289 if (map->map_type != BPF_MAP_TYPE_HASH && 1290 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1291 map->map_type != BPF_MAP_TYPE_ARRAY) { 1292 ret = -EOPNOTSUPP; 1293 goto free_map_tab; 1294 } 1295 break; 1296 case BPF_KPTR_UNREF: 1297 case BPF_KPTR_REF: 1298 case BPF_KPTR_PERCPU: 1299 case BPF_REFCOUNT: 1300 if (map->map_type != BPF_MAP_TYPE_HASH && 1301 map->map_type != BPF_MAP_TYPE_PERCPU_HASH && 1302 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1303 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH && 1304 map->map_type != BPF_MAP_TYPE_ARRAY && 1305 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && 1306 map->map_type != BPF_MAP_TYPE_SK_STORAGE && 1307 map->map_type != BPF_MAP_TYPE_INODE_STORAGE && 1308 map->map_type != BPF_MAP_TYPE_TASK_STORAGE && 1309 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) { 1310 ret = -EOPNOTSUPP; 1311 goto free_map_tab; 1312 } 1313 break; 1314 case BPF_UPTR: 1315 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) { 1316 ret = -EOPNOTSUPP; 1317 goto free_map_tab; 1318 } 1319 break; 1320 case BPF_LIST_HEAD: 1321 case BPF_RB_ROOT: 1322 if (map->map_type != BPF_MAP_TYPE_HASH && 1323 map->map_type != BPF_MAP_TYPE_LRU_HASH && 1324 map->map_type != BPF_MAP_TYPE_ARRAY) { 1325 ret = -EOPNOTSUPP; 1326 goto free_map_tab; 1327 } 1328 break; 1329 default: 1330 /* Fail if map_type checks are missing for a field type */ 1331 ret = -EOPNOTSUPP; 1332 goto free_map_tab; 1333 } 1334 } 1335 } 1336 1337 ret = btf_check_and_fixup_fields(btf, map->record); 1338 if (ret < 0) 1339 goto free_map_tab; 1340 1341 if (map->ops->map_check_btf) { 1342 ret = map->ops->map_check_btf(map, btf, key_type, value_type); 1343 if (ret < 0) 1344 goto free_map_tab; 1345 } 1346 1347 return ret; 1348 free_map_tab: 1349 bpf_map_free_record(map); 1350 return ret; 1351 } 1352 1353 static bool bpf_net_capable(void) 1354 { 1355 return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN); 1356 } 1357 1358 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size 1359 /* called via syscall */ 1360 static int map_create(union bpf_attr *attr, bpfptr_t uattr) 1361 { 1362 const struct bpf_map_ops *ops; 1363 struct bpf_token *token = NULL; 1364 int numa_node = bpf_map_attr_numa_node(attr); 1365 u32 map_type = attr->map_type; 1366 struct bpf_map *map; 1367 bool token_flag; 1368 int f_flags; 1369 int err; 1370 1371 err = CHECK_ATTR(BPF_MAP_CREATE); 1372 if (err) 1373 return -EINVAL; 1374 1375 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it 1376 * to avoid per-map type checks tripping on unknown flag 1377 */ 1378 token_flag = attr->map_flags & BPF_F_TOKEN_FD; 1379 attr->map_flags &= ~BPF_F_TOKEN_FD; 1380 1381 if (attr->btf_vmlinux_value_type_id) { 1382 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS || 1383 attr->btf_key_type_id || attr->btf_value_type_id) 1384 return -EINVAL; 1385 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) { 1386 return -EINVAL; 1387 } 1388 1389 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER && 1390 attr->map_type != BPF_MAP_TYPE_ARENA && 1391 attr->map_extra != 0) 1392 return -EINVAL; 1393 1394 f_flags = bpf_get_file_flag(attr->map_flags); 1395 if (f_flags < 0) 1396 return f_flags; 1397 1398 if (numa_node != NUMA_NO_NODE && 1399 ((unsigned int)numa_node >= nr_node_ids || 1400 !node_online(numa_node))) 1401 return -EINVAL; 1402 1403 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ 1404 map_type = attr->map_type; 1405 if (map_type >= ARRAY_SIZE(bpf_map_types)) 1406 return -EINVAL; 1407 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types)); 1408 ops = bpf_map_types[map_type]; 1409 if (!ops) 1410 return -EINVAL; 1411 1412 if (ops->map_alloc_check) { 1413 err = ops->map_alloc_check(attr); 1414 if (err) 1415 return err; 1416 } 1417 if (attr->map_ifindex) 1418 ops = &bpf_map_offload_ops; 1419 if (!ops->map_mem_usage) 1420 return -EINVAL; 1421 1422 if (token_flag) { 1423 token = bpf_token_get_from_fd(attr->map_token_fd); 1424 if (IS_ERR(token)) 1425 return PTR_ERR(token); 1426 1427 /* if current token doesn't grant map creation permissions, 1428 * then we can't use this token, so ignore it and rely on 1429 * system-wide capabilities checks 1430 */ 1431 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) || 1432 !bpf_token_allow_map_type(token, attr->map_type)) { 1433 bpf_token_put(token); 1434 token = NULL; 1435 } 1436 } 1437 1438 err = -EPERM; 1439 1440 /* Intent here is for unprivileged_bpf_disabled to block BPF map 1441 * creation for unprivileged users; other actions depend 1442 * on fd availability and access to bpffs, so are dependent on 1443 * object creation success. Even with unprivileged BPF disabled, 1444 * capability checks are still carried out. 1445 */ 1446 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF)) 1447 goto put_token; 1448 1449 /* check privileged map type permissions */ 1450 switch (map_type) { 1451 case BPF_MAP_TYPE_ARRAY: 1452 case BPF_MAP_TYPE_PERCPU_ARRAY: 1453 case BPF_MAP_TYPE_PROG_ARRAY: 1454 case BPF_MAP_TYPE_PERF_EVENT_ARRAY: 1455 case BPF_MAP_TYPE_CGROUP_ARRAY: 1456 case BPF_MAP_TYPE_ARRAY_OF_MAPS: 1457 case BPF_MAP_TYPE_HASH: 1458 case BPF_MAP_TYPE_PERCPU_HASH: 1459 case BPF_MAP_TYPE_HASH_OF_MAPS: 1460 case BPF_MAP_TYPE_RINGBUF: 1461 case BPF_MAP_TYPE_USER_RINGBUF: 1462 case BPF_MAP_TYPE_CGROUP_STORAGE: 1463 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: 1464 /* unprivileged */ 1465 break; 1466 case BPF_MAP_TYPE_SK_STORAGE: 1467 case BPF_MAP_TYPE_INODE_STORAGE: 1468 case BPF_MAP_TYPE_TASK_STORAGE: 1469 case BPF_MAP_TYPE_CGRP_STORAGE: 1470 case BPF_MAP_TYPE_BLOOM_FILTER: 1471 case BPF_MAP_TYPE_LPM_TRIE: 1472 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: 1473 case BPF_MAP_TYPE_STACK_TRACE: 1474 case BPF_MAP_TYPE_QUEUE: 1475 case BPF_MAP_TYPE_STACK: 1476 case BPF_MAP_TYPE_LRU_HASH: 1477 case BPF_MAP_TYPE_LRU_PERCPU_HASH: 1478 case BPF_MAP_TYPE_STRUCT_OPS: 1479 case BPF_MAP_TYPE_CPUMAP: 1480 case BPF_MAP_TYPE_ARENA: 1481 if (!bpf_token_capable(token, CAP_BPF)) 1482 goto put_token; 1483 break; 1484 case BPF_MAP_TYPE_SOCKMAP: 1485 case BPF_MAP_TYPE_SOCKHASH: 1486 case BPF_MAP_TYPE_DEVMAP: 1487 case BPF_MAP_TYPE_DEVMAP_HASH: 1488 case BPF_MAP_TYPE_XSKMAP: 1489 if (!bpf_token_capable(token, CAP_NET_ADMIN)) 1490 goto put_token; 1491 break; 1492 default: 1493 WARN(1, "unsupported map type %d", map_type); 1494 goto put_token; 1495 } 1496 1497 map = ops->map_alloc(attr); 1498 if (IS_ERR(map)) { 1499 err = PTR_ERR(map); 1500 goto put_token; 1501 } 1502 map->ops = ops; 1503 map->map_type = map_type; 1504 1505 err = bpf_obj_name_cpy(map->name, attr->map_name, 1506 sizeof(attr->map_name)); 1507 if (err < 0) 1508 goto free_map; 1509 1510 preempt_disable(); 1511 map->cookie = gen_cookie_next(&bpf_map_cookie); 1512 preempt_enable(); 1513 1514 atomic64_set(&map->refcnt, 1); 1515 atomic64_set(&map->usercnt, 1); 1516 mutex_init(&map->freeze_mutex); 1517 spin_lock_init(&map->owner_lock); 1518 1519 if (attr->btf_key_type_id || attr->btf_value_type_id || 1520 /* Even the map's value is a kernel's struct, 1521 * the bpf_prog.o must have BTF to begin with 1522 * to figure out the corresponding kernel's 1523 * counter part. Thus, attr->btf_fd has 1524 * to be valid also. 1525 */ 1526 attr->btf_vmlinux_value_type_id) { 1527 struct btf *btf; 1528 1529 btf = btf_get_by_fd(attr->btf_fd); 1530 if (IS_ERR(btf)) { 1531 err = PTR_ERR(btf); 1532 goto free_map; 1533 } 1534 if (btf_is_kernel(btf)) { 1535 btf_put(btf); 1536 err = -EACCES; 1537 goto free_map; 1538 } 1539 map->btf = btf; 1540 1541 if (attr->btf_value_type_id) { 1542 err = map_check_btf(map, token, btf, attr->btf_key_type_id, 1543 attr->btf_value_type_id); 1544 if (err) 1545 goto free_map; 1546 } 1547 1548 map->btf_key_type_id = attr->btf_key_type_id; 1549 map->btf_value_type_id = attr->btf_value_type_id; 1550 map->btf_vmlinux_value_type_id = 1551 attr->btf_vmlinux_value_type_id; 1552 } 1553 1554 if (attr->excl_prog_hash) { 1555 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel); 1556 1557 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) { 1558 err = -EINVAL; 1559 goto free_map; 1560 } 1561 1562 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL); 1563 if (!map->excl_prog_sha) { 1564 err = -ENOMEM; 1565 goto free_map; 1566 } 1567 1568 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) { 1569 err = -EFAULT; 1570 goto free_map; 1571 } 1572 } else if (attr->excl_prog_hash_size) { 1573 return -EINVAL; 1574 } 1575 1576 err = security_bpf_map_create(map, attr, token, uattr.is_kernel); 1577 if (err) 1578 goto free_map_sec; 1579 1580 err = bpf_map_alloc_id(map); 1581 if (err) 1582 goto free_map_sec; 1583 1584 bpf_map_save_memcg(map); 1585 bpf_token_put(token); 1586 1587 err = bpf_map_new_fd(map, f_flags); 1588 if (err < 0) { 1589 /* failed to allocate fd. 1590 * bpf_map_put_with_uref() is needed because the above 1591 * bpf_map_alloc_id() has published the map 1592 * to the userspace and the userspace may 1593 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. 1594 */ 1595 bpf_map_put_with_uref(map); 1596 return err; 1597 } 1598 1599 return err; 1600 1601 free_map_sec: 1602 security_bpf_map_free(map); 1603 free_map: 1604 bpf_map_free(map); 1605 put_token: 1606 bpf_token_put(token); 1607 return err; 1608 } 1609 1610 void bpf_map_inc(struct bpf_map *map) 1611 { 1612 atomic64_inc(&map->refcnt); 1613 } 1614 EXPORT_SYMBOL_GPL(bpf_map_inc); 1615 1616 void bpf_map_inc_with_uref(struct bpf_map *map) 1617 { 1618 atomic64_inc(&map->refcnt); 1619 atomic64_inc(&map->usercnt); 1620 } 1621 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref); 1622 1623 struct bpf_map *bpf_map_get(u32 ufd) 1624 { 1625 CLASS(fd, f)(ufd); 1626 struct bpf_map *map = __bpf_map_get(f); 1627 1628 if (!IS_ERR(map)) 1629 bpf_map_inc(map); 1630 1631 return map; 1632 } 1633 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); 1634 1635 struct bpf_map *bpf_map_get_with_uref(u32 ufd) 1636 { 1637 CLASS(fd, f)(ufd); 1638 struct bpf_map *map = __bpf_map_get(f); 1639 1640 if (!IS_ERR(map)) 1641 bpf_map_inc_with_uref(map); 1642 1643 return map; 1644 } 1645 1646 /* map_idr_lock should have been held or the map should have been 1647 * protected by rcu read lock. 1648 */ 1649 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref) 1650 { 1651 int refold; 1652 1653 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0); 1654 if (!refold) 1655 return ERR_PTR(-ENOENT); 1656 if (uref) 1657 atomic64_inc(&map->usercnt); 1658 1659 return map; 1660 } 1661 1662 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map) 1663 { 1664 lockdep_assert(rcu_read_lock_held()); 1665 return __bpf_map_inc_not_zero(map, false); 1666 } 1667 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero); 1668 1669 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) 1670 { 1671 return -ENOTSUPP; 1672 } 1673 1674 static void *__bpf_copy_key(void __user *ukey, u64 key_size) 1675 { 1676 if (key_size) 1677 return vmemdup_user(ukey, key_size); 1678 1679 if (ukey) 1680 return ERR_PTR(-EINVAL); 1681 1682 return NULL; 1683 } 1684 1685 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size) 1686 { 1687 if (key_size) 1688 return kvmemdup_bpfptr(ukey, key_size); 1689 1690 if (!bpfptr_is_null(ukey)) 1691 return ERR_PTR(-EINVAL); 1692 1693 return NULL; 1694 } 1695 1696 /* last field in 'union bpf_attr' used by this command */ 1697 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags 1698 1699 static int map_lookup_elem(union bpf_attr *attr) 1700 { 1701 void __user *ukey = u64_to_user_ptr(attr->key); 1702 void __user *uvalue = u64_to_user_ptr(attr->value); 1703 struct bpf_map *map; 1704 void *key, *value; 1705 u32 value_size; 1706 int err; 1707 1708 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) 1709 return -EINVAL; 1710 1711 if (attr->flags & ~BPF_F_LOCK) 1712 return -EINVAL; 1713 1714 CLASS(fd, f)(attr->map_fd); 1715 map = __bpf_map_get(f); 1716 if (IS_ERR(map)) 1717 return PTR_ERR(map); 1718 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1719 return -EPERM; 1720 1721 if ((attr->flags & BPF_F_LOCK) && 1722 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 1723 return -EINVAL; 1724 1725 key = __bpf_copy_key(ukey, map->key_size); 1726 if (IS_ERR(key)) 1727 return PTR_ERR(key); 1728 1729 value_size = bpf_map_value_size(map); 1730 1731 err = -ENOMEM; 1732 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 1733 if (!value) 1734 goto free_key; 1735 1736 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) { 1737 if (copy_from_user(value, uvalue, value_size)) 1738 err = -EFAULT; 1739 else 1740 err = bpf_map_copy_value(map, key, value, attr->flags); 1741 goto free_value; 1742 } 1743 1744 err = bpf_map_copy_value(map, key, value, attr->flags); 1745 if (err) 1746 goto free_value; 1747 1748 err = -EFAULT; 1749 if (copy_to_user(uvalue, value, value_size) != 0) 1750 goto free_value; 1751 1752 err = 0; 1753 1754 free_value: 1755 kvfree(value); 1756 free_key: 1757 kvfree(key); 1758 return err; 1759 } 1760 1761 1762 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags 1763 1764 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr) 1765 { 1766 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1767 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel); 1768 struct bpf_map *map; 1769 void *key, *value; 1770 u32 value_size; 1771 int err; 1772 1773 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) 1774 return -EINVAL; 1775 1776 CLASS(fd, f)(attr->map_fd); 1777 map = __bpf_map_get(f); 1778 if (IS_ERR(map)) 1779 return PTR_ERR(map); 1780 bpf_map_write_active_inc(map); 1781 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1782 err = -EPERM; 1783 goto err_put; 1784 } 1785 1786 if ((attr->flags & BPF_F_LOCK) && 1787 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1788 err = -EINVAL; 1789 goto err_put; 1790 } 1791 1792 key = ___bpf_copy_key(ukey, map->key_size); 1793 if (IS_ERR(key)) { 1794 err = PTR_ERR(key); 1795 goto err_put; 1796 } 1797 1798 value_size = bpf_map_value_size(map); 1799 value = kvmemdup_bpfptr(uvalue, value_size); 1800 if (IS_ERR(value)) { 1801 err = PTR_ERR(value); 1802 goto free_key; 1803 } 1804 1805 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags); 1806 if (!err) 1807 maybe_wait_bpf_programs(map); 1808 1809 kvfree(value); 1810 free_key: 1811 kvfree(key); 1812 err_put: 1813 bpf_map_write_active_dec(map); 1814 return err; 1815 } 1816 1817 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key 1818 1819 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr) 1820 { 1821 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel); 1822 struct bpf_map *map; 1823 void *key; 1824 int err; 1825 1826 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) 1827 return -EINVAL; 1828 1829 CLASS(fd, f)(attr->map_fd); 1830 map = __bpf_map_get(f); 1831 if (IS_ERR(map)) 1832 return PTR_ERR(map); 1833 bpf_map_write_active_inc(map); 1834 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 1835 err = -EPERM; 1836 goto err_put; 1837 } 1838 1839 key = ___bpf_copy_key(ukey, map->key_size); 1840 if (IS_ERR(key)) { 1841 err = PTR_ERR(key); 1842 goto err_put; 1843 } 1844 1845 if (bpf_map_is_offloaded(map)) { 1846 err = bpf_map_offload_delete_elem(map, key); 1847 goto out; 1848 } else if (IS_FD_PROG_ARRAY(map) || 1849 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) { 1850 /* These maps require sleepable context */ 1851 err = map->ops->map_delete_elem(map, key); 1852 goto out; 1853 } 1854 1855 bpf_disable_instrumentation(); 1856 rcu_read_lock(); 1857 err = map->ops->map_delete_elem(map, key); 1858 rcu_read_unlock(); 1859 bpf_enable_instrumentation(); 1860 if (!err) 1861 maybe_wait_bpf_programs(map); 1862 out: 1863 kvfree(key); 1864 err_put: 1865 bpf_map_write_active_dec(map); 1866 return err; 1867 } 1868 1869 /* last field in 'union bpf_attr' used by this command */ 1870 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key 1871 1872 static int map_get_next_key(union bpf_attr *attr) 1873 { 1874 void __user *ukey = u64_to_user_ptr(attr->key); 1875 void __user *unext_key = u64_to_user_ptr(attr->next_key); 1876 struct bpf_map *map; 1877 void *key, *next_key; 1878 int err; 1879 1880 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) 1881 return -EINVAL; 1882 1883 CLASS(fd, f)(attr->map_fd); 1884 map = __bpf_map_get(f); 1885 if (IS_ERR(map)) 1886 return PTR_ERR(map); 1887 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) 1888 return -EPERM; 1889 1890 if (ukey) { 1891 key = __bpf_copy_key(ukey, map->key_size); 1892 if (IS_ERR(key)) 1893 return PTR_ERR(key); 1894 } else { 1895 key = NULL; 1896 } 1897 1898 err = -ENOMEM; 1899 next_key = kvmalloc(map->key_size, GFP_USER); 1900 if (!next_key) 1901 goto free_key; 1902 1903 if (bpf_map_is_offloaded(map)) { 1904 err = bpf_map_offload_get_next_key(map, key, next_key); 1905 goto out; 1906 } 1907 1908 rcu_read_lock(); 1909 err = map->ops->map_get_next_key(map, key, next_key); 1910 rcu_read_unlock(); 1911 out: 1912 if (err) 1913 goto free_next_key; 1914 1915 err = -EFAULT; 1916 if (copy_to_user(unext_key, next_key, map->key_size) != 0) 1917 goto free_next_key; 1918 1919 err = 0; 1920 1921 free_next_key: 1922 kvfree(next_key); 1923 free_key: 1924 kvfree(key); 1925 return err; 1926 } 1927 1928 int generic_map_delete_batch(struct bpf_map *map, 1929 const union bpf_attr *attr, 1930 union bpf_attr __user *uattr) 1931 { 1932 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1933 u32 cp, max_count; 1934 int err = 0; 1935 void *key; 1936 1937 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1938 return -EINVAL; 1939 1940 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1941 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1942 return -EINVAL; 1943 } 1944 1945 max_count = attr->batch.count; 1946 if (!max_count) 1947 return 0; 1948 1949 if (put_user(0, &uattr->batch.count)) 1950 return -EFAULT; 1951 1952 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 1953 if (!key) 1954 return -ENOMEM; 1955 1956 for (cp = 0; cp < max_count; cp++) { 1957 err = -EFAULT; 1958 if (copy_from_user(key, keys + cp * map->key_size, 1959 map->key_size)) 1960 break; 1961 1962 if (bpf_map_is_offloaded(map)) { 1963 err = bpf_map_offload_delete_elem(map, key); 1964 break; 1965 } 1966 1967 bpf_disable_instrumentation(); 1968 rcu_read_lock(); 1969 err = map->ops->map_delete_elem(map, key); 1970 rcu_read_unlock(); 1971 bpf_enable_instrumentation(); 1972 if (err) 1973 break; 1974 cond_resched(); 1975 } 1976 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 1977 err = -EFAULT; 1978 1979 kvfree(key); 1980 1981 return err; 1982 } 1983 1984 int generic_map_update_batch(struct bpf_map *map, struct file *map_file, 1985 const union bpf_attr *attr, 1986 union bpf_attr __user *uattr) 1987 { 1988 void __user *values = u64_to_user_ptr(attr->batch.values); 1989 void __user *keys = u64_to_user_ptr(attr->batch.keys); 1990 u32 value_size, cp, max_count; 1991 void *key, *value; 1992 int err = 0; 1993 1994 if (attr->batch.elem_flags & ~BPF_F_LOCK) 1995 return -EINVAL; 1996 1997 if ((attr->batch.elem_flags & BPF_F_LOCK) && 1998 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 1999 return -EINVAL; 2000 } 2001 2002 value_size = bpf_map_value_size(map); 2003 2004 max_count = attr->batch.count; 2005 if (!max_count) 2006 return 0; 2007 2008 if (put_user(0, &uattr->batch.count)) 2009 return -EFAULT; 2010 2011 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2012 if (!key) 2013 return -ENOMEM; 2014 2015 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2016 if (!value) { 2017 kvfree(key); 2018 return -ENOMEM; 2019 } 2020 2021 for (cp = 0; cp < max_count; cp++) { 2022 err = -EFAULT; 2023 if (copy_from_user(key, keys + cp * map->key_size, 2024 map->key_size) || 2025 copy_from_user(value, values + cp * value_size, value_size)) 2026 break; 2027 2028 err = bpf_map_update_value(map, map_file, key, value, 2029 attr->batch.elem_flags); 2030 2031 if (err) 2032 break; 2033 cond_resched(); 2034 } 2035 2036 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) 2037 err = -EFAULT; 2038 2039 kvfree(value); 2040 kvfree(key); 2041 2042 return err; 2043 } 2044 2045 int generic_map_lookup_batch(struct bpf_map *map, 2046 const union bpf_attr *attr, 2047 union bpf_attr __user *uattr) 2048 { 2049 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch); 2050 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); 2051 void __user *values = u64_to_user_ptr(attr->batch.values); 2052 void __user *keys = u64_to_user_ptr(attr->batch.keys); 2053 void *buf, *buf_prevkey, *prev_key, *key, *value; 2054 u32 value_size, cp, max_count; 2055 int err; 2056 2057 if (attr->batch.elem_flags & ~BPF_F_LOCK) 2058 return -EINVAL; 2059 2060 if ((attr->batch.elem_flags & BPF_F_LOCK) && 2061 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) 2062 return -EINVAL; 2063 2064 value_size = bpf_map_value_size(map); 2065 2066 max_count = attr->batch.count; 2067 if (!max_count) 2068 return 0; 2069 2070 if (put_user(0, &uattr->batch.count)) 2071 return -EFAULT; 2072 2073 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN); 2074 if (!buf_prevkey) 2075 return -ENOMEM; 2076 2077 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN); 2078 if (!buf) { 2079 kvfree(buf_prevkey); 2080 return -ENOMEM; 2081 } 2082 2083 err = -EFAULT; 2084 prev_key = NULL; 2085 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size)) 2086 goto free_buf; 2087 key = buf; 2088 value = key + map->key_size; 2089 if (ubatch) 2090 prev_key = buf_prevkey; 2091 2092 for (cp = 0; cp < max_count;) { 2093 rcu_read_lock(); 2094 err = map->ops->map_get_next_key(map, prev_key, key); 2095 rcu_read_unlock(); 2096 if (err) 2097 break; 2098 err = bpf_map_copy_value(map, key, value, 2099 attr->batch.elem_flags); 2100 2101 if (err == -ENOENT) 2102 goto next_key; 2103 2104 if (err) 2105 goto free_buf; 2106 2107 if (copy_to_user(keys + cp * map->key_size, key, 2108 map->key_size)) { 2109 err = -EFAULT; 2110 goto free_buf; 2111 } 2112 if (copy_to_user(values + cp * value_size, value, value_size)) { 2113 err = -EFAULT; 2114 goto free_buf; 2115 } 2116 2117 cp++; 2118 next_key: 2119 if (!prev_key) 2120 prev_key = buf_prevkey; 2121 2122 swap(prev_key, key); 2123 cond_resched(); 2124 } 2125 2126 if (err == -EFAULT) 2127 goto free_buf; 2128 2129 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) || 2130 (cp && copy_to_user(uobatch, prev_key, map->key_size)))) 2131 err = -EFAULT; 2132 2133 free_buf: 2134 kvfree(buf_prevkey); 2135 kvfree(buf); 2136 return err; 2137 } 2138 2139 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags 2140 2141 static int map_lookup_and_delete_elem(union bpf_attr *attr) 2142 { 2143 void __user *ukey = u64_to_user_ptr(attr->key); 2144 void __user *uvalue = u64_to_user_ptr(attr->value); 2145 struct bpf_map *map; 2146 void *key, *value; 2147 u32 value_size; 2148 int err; 2149 2150 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM)) 2151 return -EINVAL; 2152 2153 if (attr->flags & ~BPF_F_LOCK) 2154 return -EINVAL; 2155 2156 CLASS(fd, f)(attr->map_fd); 2157 map = __bpf_map_get(f); 2158 if (IS_ERR(map)) 2159 return PTR_ERR(map); 2160 bpf_map_write_active_inc(map); 2161 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || 2162 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 2163 err = -EPERM; 2164 goto err_put; 2165 } 2166 2167 if (attr->flags && 2168 (map->map_type == BPF_MAP_TYPE_QUEUE || 2169 map->map_type == BPF_MAP_TYPE_STACK)) { 2170 err = -EINVAL; 2171 goto err_put; 2172 } 2173 2174 if ((attr->flags & BPF_F_LOCK) && 2175 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) { 2176 err = -EINVAL; 2177 goto err_put; 2178 } 2179 2180 key = __bpf_copy_key(ukey, map->key_size); 2181 if (IS_ERR(key)) { 2182 err = PTR_ERR(key); 2183 goto err_put; 2184 } 2185 2186 value_size = bpf_map_value_size(map); 2187 2188 err = -ENOMEM; 2189 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); 2190 if (!value) 2191 goto free_key; 2192 2193 err = -ENOTSUPP; 2194 if (map->map_type == BPF_MAP_TYPE_QUEUE || 2195 map->map_type == BPF_MAP_TYPE_STACK) { 2196 err = map->ops->map_pop_elem(map, value); 2197 } else if (map->map_type == BPF_MAP_TYPE_HASH || 2198 map->map_type == BPF_MAP_TYPE_PERCPU_HASH || 2199 map->map_type == BPF_MAP_TYPE_LRU_HASH || 2200 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { 2201 if (!bpf_map_is_offloaded(map)) { 2202 bpf_disable_instrumentation(); 2203 rcu_read_lock(); 2204 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags); 2205 rcu_read_unlock(); 2206 bpf_enable_instrumentation(); 2207 } 2208 } 2209 2210 if (err) 2211 goto free_value; 2212 2213 if (copy_to_user(uvalue, value, value_size) != 0) { 2214 err = -EFAULT; 2215 goto free_value; 2216 } 2217 2218 err = 0; 2219 2220 free_value: 2221 kvfree(value); 2222 free_key: 2223 kvfree(key); 2224 err_put: 2225 bpf_map_write_active_dec(map); 2226 return err; 2227 } 2228 2229 #define BPF_MAP_FREEZE_LAST_FIELD map_fd 2230 2231 static int map_freeze(const union bpf_attr *attr) 2232 { 2233 int err = 0; 2234 struct bpf_map *map; 2235 2236 if (CHECK_ATTR(BPF_MAP_FREEZE)) 2237 return -EINVAL; 2238 2239 CLASS(fd, f)(attr->map_fd); 2240 map = __bpf_map_get(f); 2241 if (IS_ERR(map)) 2242 return PTR_ERR(map); 2243 2244 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) 2245 return -ENOTSUPP; 2246 2247 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) 2248 return -EPERM; 2249 2250 mutex_lock(&map->freeze_mutex); 2251 if (bpf_map_write_active(map)) { 2252 err = -EBUSY; 2253 goto err_put; 2254 } 2255 if (READ_ONCE(map->frozen)) { 2256 err = -EBUSY; 2257 goto err_put; 2258 } 2259 2260 WRITE_ONCE(map->frozen, true); 2261 err_put: 2262 mutex_unlock(&map->freeze_mutex); 2263 return err; 2264 } 2265 2266 static const struct bpf_prog_ops * const bpf_prog_types[] = { 2267 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \ 2268 [_id] = & _name ## _prog_ops, 2269 #define BPF_MAP_TYPE(_id, _ops) 2270 #define BPF_LINK_TYPE(_id, _name) 2271 #include <linux/bpf_types.h> 2272 #undef BPF_PROG_TYPE 2273 #undef BPF_MAP_TYPE 2274 #undef BPF_LINK_TYPE 2275 }; 2276 2277 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) 2278 { 2279 const struct bpf_prog_ops *ops; 2280 2281 if (type >= ARRAY_SIZE(bpf_prog_types)) 2282 return -EINVAL; 2283 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); 2284 ops = bpf_prog_types[type]; 2285 if (!ops) 2286 return -EINVAL; 2287 2288 if (!bpf_prog_is_offloaded(prog->aux)) 2289 prog->aux->ops = ops; 2290 else 2291 prog->aux->ops = &bpf_offload_prog_ops; 2292 prog->type = type; 2293 return 0; 2294 } 2295 2296 enum bpf_audit { 2297 BPF_AUDIT_LOAD, 2298 BPF_AUDIT_UNLOAD, 2299 BPF_AUDIT_MAX, 2300 }; 2301 2302 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = { 2303 [BPF_AUDIT_LOAD] = "LOAD", 2304 [BPF_AUDIT_UNLOAD] = "UNLOAD", 2305 }; 2306 2307 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) 2308 { 2309 struct audit_context *ctx = NULL; 2310 struct audit_buffer *ab; 2311 2312 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX)) 2313 return; 2314 if (audit_enabled == AUDIT_OFF) 2315 return; 2316 if (!in_irq() && !irqs_disabled()) 2317 ctx = audit_context(); 2318 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF); 2319 if (unlikely(!ab)) 2320 return; 2321 audit_log_format(ab, "prog-id=%u op=%s", 2322 prog->aux->id, bpf_audit_str[op]); 2323 audit_log_end(ab); 2324 } 2325 2326 static int bpf_prog_alloc_id(struct bpf_prog *prog) 2327 { 2328 int id; 2329 2330 idr_preload(GFP_KERNEL); 2331 spin_lock_bh(&prog_idr_lock); 2332 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); 2333 if (id > 0) 2334 prog->aux->id = id; 2335 spin_unlock_bh(&prog_idr_lock); 2336 idr_preload_end(); 2337 2338 /* id is in [1, INT_MAX) */ 2339 if (WARN_ON_ONCE(!id)) 2340 return -ENOSPC; 2341 2342 return id > 0 ? 0 : id; 2343 } 2344 2345 void bpf_prog_free_id(struct bpf_prog *prog) 2346 { 2347 unsigned long flags; 2348 2349 /* cBPF to eBPF migrations are currently not in the idr store. 2350 * Offloaded programs are removed from the store when their device 2351 * disappears - even if someone grabs an fd to them they are unusable, 2352 * simply waiting for refcnt to drop to be freed. 2353 */ 2354 if (!prog->aux->id) 2355 return; 2356 2357 spin_lock_irqsave(&prog_idr_lock, flags); 2358 idr_remove(&prog_idr, prog->aux->id); 2359 prog->aux->id = 0; 2360 spin_unlock_irqrestore(&prog_idr_lock, flags); 2361 } 2362 2363 static void __bpf_prog_put_rcu(struct rcu_head *rcu) 2364 { 2365 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); 2366 2367 kvfree(aux->func_info); 2368 kfree(aux->func_info_aux); 2369 free_uid(aux->user); 2370 security_bpf_prog_free(aux->prog); 2371 bpf_prog_free(aux->prog); 2372 } 2373 2374 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) 2375 { 2376 bpf_prog_kallsyms_del_all(prog); 2377 btf_put(prog->aux->btf); 2378 module_put(prog->aux->mod); 2379 kvfree(prog->aux->jited_linfo); 2380 kvfree(prog->aux->linfo); 2381 kfree(prog->aux->kfunc_tab); 2382 kfree(prog->aux->ctx_arg_info); 2383 if (prog->aux->attach_btf) 2384 btf_put(prog->aux->attach_btf); 2385 2386 if (deferred) { 2387 if (prog->sleepable) 2388 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu); 2389 else 2390 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); 2391 } else { 2392 __bpf_prog_put_rcu(&prog->aux->rcu); 2393 } 2394 } 2395 2396 static void bpf_prog_put_deferred(struct work_struct *work) 2397 { 2398 struct bpf_prog_aux *aux; 2399 struct bpf_prog *prog; 2400 2401 aux = container_of(work, struct bpf_prog_aux, work); 2402 prog = aux->prog; 2403 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0); 2404 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD); 2405 bpf_prog_free_id(prog); 2406 __bpf_prog_put_noref(prog, true); 2407 } 2408 2409 static void __bpf_prog_put(struct bpf_prog *prog) 2410 { 2411 struct bpf_prog_aux *aux = prog->aux; 2412 2413 if (atomic64_dec_and_test(&aux->refcnt)) { 2414 if (in_irq() || irqs_disabled()) { 2415 INIT_WORK(&aux->work, bpf_prog_put_deferred); 2416 schedule_work(&aux->work); 2417 } else { 2418 bpf_prog_put_deferred(&aux->work); 2419 } 2420 } 2421 } 2422 2423 void bpf_prog_put(struct bpf_prog *prog) 2424 { 2425 __bpf_prog_put(prog); 2426 } 2427 EXPORT_SYMBOL_GPL(bpf_prog_put); 2428 2429 static int bpf_prog_release(struct inode *inode, struct file *filp) 2430 { 2431 struct bpf_prog *prog = filp->private_data; 2432 2433 bpf_prog_put(prog); 2434 return 0; 2435 } 2436 2437 struct bpf_prog_kstats { 2438 u64 nsecs; 2439 u64 cnt; 2440 u64 misses; 2441 }; 2442 2443 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog) 2444 { 2445 struct bpf_prog_stats *stats; 2446 unsigned int flags; 2447 2448 stats = this_cpu_ptr(prog->stats); 2449 flags = u64_stats_update_begin_irqsave(&stats->syncp); 2450 u64_stats_inc(&stats->misses); 2451 u64_stats_update_end_irqrestore(&stats->syncp, flags); 2452 } 2453 2454 static void bpf_prog_get_stats(const struct bpf_prog *prog, 2455 struct bpf_prog_kstats *stats) 2456 { 2457 u64 nsecs = 0, cnt = 0, misses = 0; 2458 int cpu; 2459 2460 for_each_possible_cpu(cpu) { 2461 const struct bpf_prog_stats *st; 2462 unsigned int start; 2463 u64 tnsecs, tcnt, tmisses; 2464 2465 st = per_cpu_ptr(prog->stats, cpu); 2466 do { 2467 start = u64_stats_fetch_begin(&st->syncp); 2468 tnsecs = u64_stats_read(&st->nsecs); 2469 tcnt = u64_stats_read(&st->cnt); 2470 tmisses = u64_stats_read(&st->misses); 2471 } while (u64_stats_fetch_retry(&st->syncp, start)); 2472 nsecs += tnsecs; 2473 cnt += tcnt; 2474 misses += tmisses; 2475 } 2476 stats->nsecs = nsecs; 2477 stats->cnt = cnt; 2478 stats->misses = misses; 2479 } 2480 2481 #ifdef CONFIG_PROC_FS 2482 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) 2483 { 2484 const struct bpf_prog *prog = filp->private_data; 2485 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 2486 struct bpf_prog_kstats stats; 2487 2488 bpf_prog_get_stats(prog, &stats); 2489 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 2490 seq_printf(m, 2491 "prog_type:\t%u\n" 2492 "prog_jited:\t%u\n" 2493 "prog_tag:\t%s\n" 2494 "memlock:\t%llu\n" 2495 "prog_id:\t%u\n" 2496 "run_time_ns:\t%llu\n" 2497 "run_cnt:\t%llu\n" 2498 "recursion_misses:\t%llu\n" 2499 "verified_insns:\t%u\n", 2500 prog->type, 2501 prog->jited, 2502 prog_tag, 2503 prog->pages * 1ULL << PAGE_SHIFT, 2504 prog->aux->id, 2505 stats.nsecs, 2506 stats.cnt, 2507 stats.misses, 2508 prog->aux->verified_insns); 2509 } 2510 #endif 2511 2512 const struct file_operations bpf_prog_fops = { 2513 #ifdef CONFIG_PROC_FS 2514 .show_fdinfo = bpf_prog_show_fdinfo, 2515 #endif 2516 .release = bpf_prog_release, 2517 .read = bpf_dummy_read, 2518 .write = bpf_dummy_write, 2519 }; 2520 2521 int bpf_prog_new_fd(struct bpf_prog *prog) 2522 { 2523 int ret; 2524 2525 ret = security_bpf_prog(prog); 2526 if (ret < 0) 2527 return ret; 2528 2529 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, 2530 O_RDWR | O_CLOEXEC); 2531 } 2532 2533 void bpf_prog_add(struct bpf_prog *prog, int i) 2534 { 2535 atomic64_add(i, &prog->aux->refcnt); 2536 } 2537 EXPORT_SYMBOL_GPL(bpf_prog_add); 2538 2539 void bpf_prog_sub(struct bpf_prog *prog, int i) 2540 { 2541 /* Only to be used for undoing previous bpf_prog_add() in some 2542 * error path. We still know that another entity in our call 2543 * path holds a reference to the program, thus atomic_sub() can 2544 * be safely used in such cases! 2545 */ 2546 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0); 2547 } 2548 EXPORT_SYMBOL_GPL(bpf_prog_sub); 2549 2550 void bpf_prog_inc(struct bpf_prog *prog) 2551 { 2552 atomic64_inc(&prog->aux->refcnt); 2553 } 2554 EXPORT_SYMBOL_GPL(bpf_prog_inc); 2555 2556 /* prog_idr_lock should have been held */ 2557 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) 2558 { 2559 int refold; 2560 2561 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0); 2562 2563 if (!refold) 2564 return ERR_PTR(-ENOENT); 2565 2566 return prog; 2567 } 2568 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); 2569 2570 bool bpf_prog_get_ok(struct bpf_prog *prog, 2571 enum bpf_prog_type *attach_type, bool attach_drv) 2572 { 2573 /* not an attachment, just a refcount inc, always allow */ 2574 if (!attach_type) 2575 return true; 2576 2577 if (prog->type != *attach_type) 2578 return false; 2579 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv) 2580 return false; 2581 2582 return true; 2583 } 2584 2585 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, 2586 bool attach_drv) 2587 { 2588 CLASS(fd, f)(ufd); 2589 struct bpf_prog *prog; 2590 2591 if (fd_empty(f)) 2592 return ERR_PTR(-EBADF); 2593 if (fd_file(f)->f_op != &bpf_prog_fops) 2594 return ERR_PTR(-EINVAL); 2595 2596 prog = fd_file(f)->private_data; 2597 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) 2598 return ERR_PTR(-EINVAL); 2599 2600 bpf_prog_inc(prog); 2601 return prog; 2602 } 2603 2604 struct bpf_prog *bpf_prog_get(u32 ufd) 2605 { 2606 return __bpf_prog_get(ufd, NULL, false); 2607 } 2608 2609 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, 2610 bool attach_drv) 2611 { 2612 return __bpf_prog_get(ufd, &type, attach_drv); 2613 } 2614 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); 2615 2616 /* Initially all BPF programs could be loaded w/o specifying 2617 * expected_attach_type. Later for some of them specifying expected_attach_type 2618 * at load time became required so that program could be validated properly. 2619 * Programs of types that are allowed to be loaded both w/ and w/o (for 2620 * backward compatibility) expected_attach_type, should have the default attach 2621 * type assigned to expected_attach_type for the latter case, so that it can be 2622 * validated later at attach time. 2623 * 2624 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if 2625 * prog type requires it but has some attach types that have to be backward 2626 * compatible. 2627 */ 2628 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) 2629 { 2630 switch (attr->prog_type) { 2631 case BPF_PROG_TYPE_CGROUP_SOCK: 2632 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't 2633 * exist so checking for non-zero is the way to go here. 2634 */ 2635 if (!attr->expected_attach_type) 2636 attr->expected_attach_type = 2637 BPF_CGROUP_INET_SOCK_CREATE; 2638 break; 2639 case BPF_PROG_TYPE_SK_REUSEPORT: 2640 if (!attr->expected_attach_type) 2641 attr->expected_attach_type = 2642 BPF_SK_REUSEPORT_SELECT; 2643 break; 2644 } 2645 } 2646 2647 static int 2648 bpf_prog_load_check_attach(enum bpf_prog_type prog_type, 2649 enum bpf_attach_type expected_attach_type, 2650 struct btf *attach_btf, u32 btf_id, 2651 struct bpf_prog *dst_prog) 2652 { 2653 if (btf_id) { 2654 if (btf_id > BTF_MAX_TYPE) 2655 return -EINVAL; 2656 2657 if (!attach_btf && !dst_prog) 2658 return -EINVAL; 2659 2660 switch (prog_type) { 2661 case BPF_PROG_TYPE_TRACING: 2662 case BPF_PROG_TYPE_LSM: 2663 case BPF_PROG_TYPE_STRUCT_OPS: 2664 case BPF_PROG_TYPE_EXT: 2665 break; 2666 default: 2667 return -EINVAL; 2668 } 2669 } 2670 2671 if (attach_btf && (!btf_id || dst_prog)) 2672 return -EINVAL; 2673 2674 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING && 2675 prog_type != BPF_PROG_TYPE_EXT) 2676 return -EINVAL; 2677 2678 switch (prog_type) { 2679 case BPF_PROG_TYPE_CGROUP_SOCK: 2680 switch (expected_attach_type) { 2681 case BPF_CGROUP_INET_SOCK_CREATE: 2682 case BPF_CGROUP_INET_SOCK_RELEASE: 2683 case BPF_CGROUP_INET4_POST_BIND: 2684 case BPF_CGROUP_INET6_POST_BIND: 2685 return 0; 2686 default: 2687 return -EINVAL; 2688 } 2689 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2690 switch (expected_attach_type) { 2691 case BPF_CGROUP_INET4_BIND: 2692 case BPF_CGROUP_INET6_BIND: 2693 case BPF_CGROUP_INET4_CONNECT: 2694 case BPF_CGROUP_INET6_CONNECT: 2695 case BPF_CGROUP_UNIX_CONNECT: 2696 case BPF_CGROUP_INET4_GETPEERNAME: 2697 case BPF_CGROUP_INET6_GETPEERNAME: 2698 case BPF_CGROUP_UNIX_GETPEERNAME: 2699 case BPF_CGROUP_INET4_GETSOCKNAME: 2700 case BPF_CGROUP_INET6_GETSOCKNAME: 2701 case BPF_CGROUP_UNIX_GETSOCKNAME: 2702 case BPF_CGROUP_UDP4_SENDMSG: 2703 case BPF_CGROUP_UDP6_SENDMSG: 2704 case BPF_CGROUP_UNIX_SENDMSG: 2705 case BPF_CGROUP_UDP4_RECVMSG: 2706 case BPF_CGROUP_UDP6_RECVMSG: 2707 case BPF_CGROUP_UNIX_RECVMSG: 2708 return 0; 2709 default: 2710 return -EINVAL; 2711 } 2712 case BPF_PROG_TYPE_CGROUP_SKB: 2713 switch (expected_attach_type) { 2714 case BPF_CGROUP_INET_INGRESS: 2715 case BPF_CGROUP_INET_EGRESS: 2716 return 0; 2717 default: 2718 return -EINVAL; 2719 } 2720 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2721 switch (expected_attach_type) { 2722 case BPF_CGROUP_SETSOCKOPT: 2723 case BPF_CGROUP_GETSOCKOPT: 2724 return 0; 2725 default: 2726 return -EINVAL; 2727 } 2728 case BPF_PROG_TYPE_SK_LOOKUP: 2729 if (expected_attach_type == BPF_SK_LOOKUP) 2730 return 0; 2731 return -EINVAL; 2732 case BPF_PROG_TYPE_SK_REUSEPORT: 2733 switch (expected_attach_type) { 2734 case BPF_SK_REUSEPORT_SELECT: 2735 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: 2736 return 0; 2737 default: 2738 return -EINVAL; 2739 } 2740 case BPF_PROG_TYPE_NETFILTER: 2741 if (expected_attach_type == BPF_NETFILTER) 2742 return 0; 2743 return -EINVAL; 2744 case BPF_PROG_TYPE_SYSCALL: 2745 case BPF_PROG_TYPE_EXT: 2746 if (expected_attach_type) 2747 return -EINVAL; 2748 fallthrough; 2749 default: 2750 return 0; 2751 } 2752 } 2753 2754 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type) 2755 { 2756 switch (prog_type) { 2757 case BPF_PROG_TYPE_SCHED_CLS: 2758 case BPF_PROG_TYPE_SCHED_ACT: 2759 case BPF_PROG_TYPE_XDP: 2760 case BPF_PROG_TYPE_LWT_IN: 2761 case BPF_PROG_TYPE_LWT_OUT: 2762 case BPF_PROG_TYPE_LWT_XMIT: 2763 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2764 case BPF_PROG_TYPE_SK_SKB: 2765 case BPF_PROG_TYPE_SK_MSG: 2766 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2767 case BPF_PROG_TYPE_CGROUP_DEVICE: 2768 case BPF_PROG_TYPE_CGROUP_SOCK: 2769 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2770 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2771 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2772 case BPF_PROG_TYPE_SOCK_OPS: 2773 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2774 case BPF_PROG_TYPE_NETFILTER: 2775 return true; 2776 case BPF_PROG_TYPE_CGROUP_SKB: 2777 /* always unpriv */ 2778 case BPF_PROG_TYPE_SK_REUSEPORT: 2779 /* equivalent to SOCKET_FILTER. need CAP_BPF only */ 2780 default: 2781 return false; 2782 } 2783 } 2784 2785 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) 2786 { 2787 switch (prog_type) { 2788 case BPF_PROG_TYPE_KPROBE: 2789 case BPF_PROG_TYPE_TRACEPOINT: 2790 case BPF_PROG_TYPE_PERF_EVENT: 2791 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2792 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2793 case BPF_PROG_TYPE_TRACING: 2794 case BPF_PROG_TYPE_LSM: 2795 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */ 2796 case BPF_PROG_TYPE_EXT: /* extends any prog */ 2797 return true; 2798 default: 2799 return false; 2800 } 2801 } 2802 2803 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr, 2804 bool is_kernel) 2805 { 2806 bpfptr_t usig = make_bpfptr(attr->signature, is_kernel); 2807 struct bpf_dynptr_kern sig_ptr, insns_ptr; 2808 struct bpf_key *key = NULL; 2809 void *sig; 2810 int err = 0; 2811 2812 if (system_keyring_id_check(attr->keyring_id) == 0) 2813 key = bpf_lookup_system_key(attr->keyring_id); 2814 else 2815 key = bpf_lookup_user_key(attr->keyring_id, 0); 2816 2817 if (!key) 2818 return -EINVAL; 2819 2820 sig = kvmemdup_bpfptr(usig, attr->signature_size); 2821 if (IS_ERR(sig)) { 2822 bpf_key_put(key); 2823 return -ENOMEM; 2824 } 2825 2826 bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0, 2827 attr->signature_size); 2828 bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0, 2829 prog->len * sizeof(struct bpf_insn)); 2830 2831 err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr, 2832 (struct bpf_dynptr *)&sig_ptr, key); 2833 2834 bpf_key_put(key); 2835 kvfree(sig); 2836 return err; 2837 } 2838 2839 /* last field in 'union bpf_attr' used by this command */ 2840 #define BPF_PROG_LOAD_LAST_FIELD keyring_id 2841 2842 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) 2843 { 2844 enum bpf_prog_type type = attr->prog_type; 2845 struct bpf_prog *prog, *dst_prog = NULL; 2846 struct btf *attach_btf = NULL; 2847 struct bpf_token *token = NULL; 2848 bool bpf_cap; 2849 int err; 2850 char license[128]; 2851 2852 if (CHECK_ATTR(BPF_PROG_LOAD)) 2853 return -EINVAL; 2854 2855 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT | 2856 BPF_F_ANY_ALIGNMENT | 2857 BPF_F_TEST_STATE_FREQ | 2858 BPF_F_SLEEPABLE | 2859 BPF_F_TEST_RND_HI32 | 2860 BPF_F_XDP_HAS_FRAGS | 2861 BPF_F_XDP_DEV_BOUND_ONLY | 2862 BPF_F_TEST_REG_INVARIANTS | 2863 BPF_F_TOKEN_FD)) 2864 return -EINVAL; 2865 2866 bpf_prog_load_fixup_attach_type(attr); 2867 2868 if (attr->prog_flags & BPF_F_TOKEN_FD) { 2869 token = bpf_token_get_from_fd(attr->prog_token_fd); 2870 if (IS_ERR(token)) 2871 return PTR_ERR(token); 2872 /* if current token doesn't grant prog loading permissions, 2873 * then we can't use this token, so ignore it and rely on 2874 * system-wide capabilities checks 2875 */ 2876 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) || 2877 !bpf_token_allow_prog_type(token, attr->prog_type, 2878 attr->expected_attach_type)) { 2879 bpf_token_put(token); 2880 token = NULL; 2881 } 2882 } 2883 2884 bpf_cap = bpf_token_capable(token, CAP_BPF); 2885 err = -EPERM; 2886 2887 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && 2888 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) && 2889 !bpf_cap) 2890 goto put_token; 2891 2892 /* Intent here is for unprivileged_bpf_disabled to block BPF program 2893 * creation for unprivileged users; other actions depend 2894 * on fd availability and access to bpffs, so are dependent on 2895 * object creation success. Even with unprivileged BPF disabled, 2896 * capability checks are still carried out for these 2897 * and other operations. 2898 */ 2899 if (sysctl_unprivileged_bpf_disabled && !bpf_cap) 2900 goto put_token; 2901 2902 if (attr->insn_cnt == 0 || 2903 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) { 2904 err = -E2BIG; 2905 goto put_token; 2906 } 2907 if (type != BPF_PROG_TYPE_SOCKET_FILTER && 2908 type != BPF_PROG_TYPE_CGROUP_SKB && 2909 !bpf_cap) 2910 goto put_token; 2911 2912 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN)) 2913 goto put_token; 2914 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON)) 2915 goto put_token; 2916 2917 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog 2918 * or btf, we need to check which one it is 2919 */ 2920 if (attr->attach_prog_fd) { 2921 dst_prog = bpf_prog_get(attr->attach_prog_fd); 2922 if (IS_ERR(dst_prog)) { 2923 dst_prog = NULL; 2924 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd); 2925 if (IS_ERR(attach_btf)) { 2926 err = -EINVAL; 2927 goto put_token; 2928 } 2929 if (!btf_is_kernel(attach_btf)) { 2930 /* attaching through specifying bpf_prog's BTF 2931 * objects directly might be supported eventually 2932 */ 2933 btf_put(attach_btf); 2934 err = -ENOTSUPP; 2935 goto put_token; 2936 } 2937 } 2938 } else if (attr->attach_btf_id) { 2939 /* fall back to vmlinux BTF, if BTF type ID is specified */ 2940 attach_btf = bpf_get_btf_vmlinux(); 2941 if (IS_ERR(attach_btf)) { 2942 err = PTR_ERR(attach_btf); 2943 goto put_token; 2944 } 2945 if (!attach_btf) { 2946 err = -EINVAL; 2947 goto put_token; 2948 } 2949 btf_get(attach_btf); 2950 } 2951 2952 if (bpf_prog_load_check_attach(type, attr->expected_attach_type, 2953 attach_btf, attr->attach_btf_id, 2954 dst_prog)) { 2955 if (dst_prog) 2956 bpf_prog_put(dst_prog); 2957 if (attach_btf) 2958 btf_put(attach_btf); 2959 err = -EINVAL; 2960 goto put_token; 2961 } 2962 2963 /* plain bpf_prog allocation */ 2964 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); 2965 if (!prog) { 2966 if (dst_prog) 2967 bpf_prog_put(dst_prog); 2968 if (attach_btf) 2969 btf_put(attach_btf); 2970 err = -EINVAL; 2971 goto put_token; 2972 } 2973 2974 prog->expected_attach_type = attr->expected_attach_type; 2975 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE); 2976 prog->aux->attach_btf = attach_btf; 2977 prog->aux->attach_btf_id = attr->attach_btf_id; 2978 prog->aux->dst_prog = dst_prog; 2979 prog->aux->dev_bound = !!attr->prog_ifindex; 2980 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; 2981 2982 /* move token into prog->aux, reuse taken refcnt */ 2983 prog->aux->token = token; 2984 token = NULL; 2985 2986 prog->aux->user = get_current_user(); 2987 prog->len = attr->insn_cnt; 2988 2989 err = -EFAULT; 2990 if (copy_from_bpfptr(prog->insns, 2991 make_bpfptr(attr->insns, uattr.is_kernel), 2992 bpf_prog_insn_size(prog)) != 0) 2993 goto free_prog; 2994 /* copy eBPF program license from user space */ 2995 if (strncpy_from_bpfptr(license, 2996 make_bpfptr(attr->license, uattr.is_kernel), 2997 sizeof(license) - 1) < 0) 2998 goto free_prog; 2999 license[sizeof(license) - 1] = 0; 3000 3001 /* eBPF programs must be GPL compatible to use GPL-ed functions */ 3002 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0; 3003 3004 if (attr->signature) { 3005 err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel); 3006 if (err) 3007 goto free_prog; 3008 } 3009 3010 prog->orig_prog = NULL; 3011 prog->jited = 0; 3012 3013 atomic64_set(&prog->aux->refcnt, 1); 3014 3015 if (bpf_prog_is_dev_bound(prog->aux)) { 3016 err = bpf_prog_dev_bound_init(prog, attr); 3017 if (err) 3018 goto free_prog; 3019 } 3020 3021 if (type == BPF_PROG_TYPE_EXT && dst_prog && 3022 bpf_prog_is_dev_bound(dst_prog->aux)) { 3023 err = bpf_prog_dev_bound_inherit(prog, dst_prog); 3024 if (err) 3025 goto free_prog; 3026 } 3027 3028 /* 3029 * Bookkeeping for managing the program attachment chain. 3030 * 3031 * It might be tempting to set attach_tracing_prog flag at the attachment 3032 * time, but this will not prevent from loading bunch of tracing prog 3033 * first, then attach them one to another. 3034 * 3035 * The flag attach_tracing_prog is set for the whole program lifecycle, and 3036 * doesn't have to be cleared in bpf_tracing_link_release, since tracing 3037 * programs cannot change attachment target. 3038 */ 3039 if (type == BPF_PROG_TYPE_TRACING && dst_prog && 3040 dst_prog->type == BPF_PROG_TYPE_TRACING) { 3041 prog->aux->attach_tracing_prog = true; 3042 } 3043 3044 /* find program type: socket_filter vs tracing_filter */ 3045 err = find_prog_type(type, prog); 3046 if (err < 0) 3047 goto free_prog; 3048 3049 prog->aux->load_time = ktime_get_boottime_ns(); 3050 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name, 3051 sizeof(attr->prog_name)); 3052 if (err < 0) 3053 goto free_prog; 3054 3055 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel); 3056 if (err) 3057 goto free_prog_sec; 3058 3059 /* run eBPF verifier */ 3060 err = bpf_check(&prog, attr, uattr, uattr_size); 3061 if (err < 0) 3062 goto free_used_maps; 3063 3064 prog = bpf_prog_select_runtime(prog, &err); 3065 if (err < 0) 3066 goto free_used_maps; 3067 3068 err = bpf_prog_alloc_id(prog); 3069 if (err) 3070 goto free_used_maps; 3071 3072 /* Upon success of bpf_prog_alloc_id(), the BPF prog is 3073 * effectively publicly exposed. However, retrieving via 3074 * bpf_prog_get_fd_by_id() will take another reference, 3075 * therefore it cannot be gone underneath us. 3076 * 3077 * Only for the time /after/ successful bpf_prog_new_fd() 3078 * and before returning to userspace, we might just hold 3079 * one reference and any parallel close on that fd could 3080 * rip everything out. Hence, below notifications must 3081 * happen before bpf_prog_new_fd(). 3082 * 3083 * Also, any failure handling from this point onwards must 3084 * be using bpf_prog_put() given the program is exposed. 3085 */ 3086 bpf_prog_kallsyms_add(prog); 3087 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0); 3088 bpf_audit_prog(prog, BPF_AUDIT_LOAD); 3089 3090 err = bpf_prog_new_fd(prog); 3091 if (err < 0) 3092 bpf_prog_put(prog); 3093 return err; 3094 3095 free_used_maps: 3096 /* In case we have subprogs, we need to wait for a grace 3097 * period before we can tear down JIT memory since symbols 3098 * are already exposed under kallsyms. 3099 */ 3100 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt); 3101 return err; 3102 3103 free_prog_sec: 3104 security_bpf_prog_free(prog); 3105 free_prog: 3106 free_uid(prog->aux->user); 3107 if (prog->aux->attach_btf) 3108 btf_put(prog->aux->attach_btf); 3109 bpf_prog_free(prog); 3110 put_token: 3111 bpf_token_put(token); 3112 return err; 3113 } 3114 3115 #define BPF_OBJ_LAST_FIELD path_fd 3116 3117 static int bpf_obj_pin(const union bpf_attr *attr) 3118 { 3119 int path_fd; 3120 3121 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD) 3122 return -EINVAL; 3123 3124 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3125 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3126 return -EINVAL; 3127 3128 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3129 return bpf_obj_pin_user(attr->bpf_fd, path_fd, 3130 u64_to_user_ptr(attr->pathname)); 3131 } 3132 3133 static int bpf_obj_get(const union bpf_attr *attr) 3134 { 3135 int path_fd; 3136 3137 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || 3138 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD)) 3139 return -EINVAL; 3140 3141 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */ 3142 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd) 3143 return -EINVAL; 3144 3145 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD; 3146 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname), 3147 attr->file_flags); 3148 } 3149 3150 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has 3151 * "sleepable" semantics, which normally would mean that BPF link's attach 3152 * hook can dereference link or link's underlying program for some time after 3153 * detachment due to RCU Tasks Trace-based lifetime protection scheme. 3154 * BPF program itself can be non-sleepable, yet, because it's transitively 3155 * reachable through BPF link, its freeing has to be delayed until after RCU 3156 * Tasks Trace GP. 3157 */ 3158 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type, 3159 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3160 enum bpf_attach_type attach_type, bool sleepable) 3161 { 3162 WARN_ON(ops->dealloc && ops->dealloc_deferred); 3163 atomic64_set(&link->refcnt, 1); 3164 link->type = type; 3165 link->sleepable = sleepable; 3166 link->id = 0; 3167 link->ops = ops; 3168 link->prog = prog; 3169 link->attach_type = attach_type; 3170 } 3171 3172 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type, 3173 const struct bpf_link_ops *ops, struct bpf_prog *prog, 3174 enum bpf_attach_type attach_type) 3175 { 3176 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false); 3177 } 3178 3179 static void bpf_link_free_id(int id) 3180 { 3181 if (!id) 3182 return; 3183 3184 spin_lock_bh(&link_idr_lock); 3185 idr_remove(&link_idr, id); 3186 spin_unlock_bh(&link_idr_lock); 3187 } 3188 3189 /* Clean up bpf_link and corresponding anon_inode file and FD. After 3190 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred 3191 * anon_inode's release() call. This helper marks bpf_link as 3192 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt 3193 * is not decremented, it's the responsibility of a calling code that failed 3194 * to complete bpf_link initialization. 3195 * This helper eventually calls link's dealloc callback, but does not call 3196 * link's release callback. 3197 */ 3198 void bpf_link_cleanup(struct bpf_link_primer *primer) 3199 { 3200 primer->link->prog = NULL; 3201 bpf_link_free_id(primer->id); 3202 fput(primer->file); 3203 put_unused_fd(primer->fd); 3204 } 3205 3206 void bpf_link_inc(struct bpf_link *link) 3207 { 3208 atomic64_inc(&link->refcnt); 3209 } 3210 3211 static void bpf_link_dealloc(struct bpf_link *link) 3212 { 3213 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */ 3214 if (link->prog) 3215 bpf_prog_put(link->prog); 3216 3217 /* free bpf_link and its containing memory */ 3218 if (link->ops->dealloc_deferred) 3219 link->ops->dealloc_deferred(link); 3220 else 3221 link->ops->dealloc(link); 3222 } 3223 3224 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu) 3225 { 3226 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu); 3227 3228 bpf_link_dealloc(link); 3229 } 3230 3231 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu) 3232 { 3233 if (rcu_trace_implies_rcu_gp()) 3234 bpf_link_defer_dealloc_rcu_gp(rcu); 3235 else 3236 call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp); 3237 } 3238 3239 /* bpf_link_free is guaranteed to be called from process context */ 3240 static void bpf_link_free(struct bpf_link *link) 3241 { 3242 const struct bpf_link_ops *ops = link->ops; 3243 3244 bpf_link_free_id(link->id); 3245 /* detach BPF program, clean up used resources */ 3246 if (link->prog) 3247 ops->release(link); 3248 if (ops->dealloc_deferred) { 3249 /* Schedule BPF link deallocation, which will only then 3250 * trigger putting BPF program refcount. 3251 * If underlying BPF program is sleepable or BPF link's target 3252 * attach hookpoint is sleepable or otherwise requires RCU GPs 3253 * to ensure link and its underlying BPF program is not 3254 * reachable anymore, we need to first wait for RCU tasks 3255 * trace sync, and then go through "classic" RCU grace period 3256 */ 3257 if (link->sleepable || (link->prog && link->prog->sleepable)) 3258 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp); 3259 else 3260 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp); 3261 } else if (ops->dealloc) { 3262 bpf_link_dealloc(link); 3263 } 3264 } 3265 3266 static void bpf_link_put_deferred(struct work_struct *work) 3267 { 3268 struct bpf_link *link = container_of(work, struct bpf_link, work); 3269 3270 bpf_link_free(link); 3271 } 3272 3273 /* bpf_link_put might be called from atomic context. It needs to be called 3274 * from sleepable context in order to acquire sleeping locks during the process. 3275 */ 3276 void bpf_link_put(struct bpf_link *link) 3277 { 3278 if (!atomic64_dec_and_test(&link->refcnt)) 3279 return; 3280 3281 INIT_WORK(&link->work, bpf_link_put_deferred); 3282 schedule_work(&link->work); 3283 } 3284 EXPORT_SYMBOL(bpf_link_put); 3285 3286 static void bpf_link_put_direct(struct bpf_link *link) 3287 { 3288 if (!atomic64_dec_and_test(&link->refcnt)) 3289 return; 3290 bpf_link_free(link); 3291 } 3292 3293 static int bpf_link_release(struct inode *inode, struct file *filp) 3294 { 3295 struct bpf_link *link = filp->private_data; 3296 3297 bpf_link_put_direct(link); 3298 return 0; 3299 } 3300 3301 #ifdef CONFIG_PROC_FS 3302 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) 3303 #define BPF_MAP_TYPE(_id, _ops) 3304 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name, 3305 static const char *bpf_link_type_strs[] = { 3306 [BPF_LINK_TYPE_UNSPEC] = "<invalid>", 3307 #include <linux/bpf_types.h> 3308 }; 3309 #undef BPF_PROG_TYPE 3310 #undef BPF_MAP_TYPE 3311 #undef BPF_LINK_TYPE 3312 3313 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp) 3314 { 3315 const struct bpf_link *link = filp->private_data; 3316 const struct bpf_prog *prog = link->prog; 3317 enum bpf_link_type type = link->type; 3318 char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; 3319 3320 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) { 3321 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI) 3322 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ? 3323 "kretprobe_multi" : "kprobe_multi"); 3324 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI) 3325 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ? 3326 "uretprobe_multi" : "uprobe_multi"); 3327 else 3328 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]); 3329 } else { 3330 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type); 3331 seq_printf(m, "link_type:\t<%u>\n", type); 3332 } 3333 seq_printf(m, "link_id:\t%u\n", link->id); 3334 3335 if (prog) { 3336 bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); 3337 seq_printf(m, 3338 "prog_tag:\t%s\n" 3339 "prog_id:\t%u\n", 3340 prog_tag, 3341 prog->aux->id); 3342 } 3343 if (link->ops->show_fdinfo) 3344 link->ops->show_fdinfo(link, m); 3345 } 3346 #endif 3347 3348 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts) 3349 { 3350 struct bpf_link *link = file->private_data; 3351 3352 return link->ops->poll(file, pts); 3353 } 3354 3355 static const struct file_operations bpf_link_fops = { 3356 #ifdef CONFIG_PROC_FS 3357 .show_fdinfo = bpf_link_show_fdinfo, 3358 #endif 3359 .release = bpf_link_release, 3360 .read = bpf_dummy_read, 3361 .write = bpf_dummy_write, 3362 }; 3363 3364 static const struct file_operations bpf_link_fops_poll = { 3365 #ifdef CONFIG_PROC_FS 3366 .show_fdinfo = bpf_link_show_fdinfo, 3367 #endif 3368 .release = bpf_link_release, 3369 .read = bpf_dummy_read, 3370 .write = bpf_dummy_write, 3371 .poll = bpf_link_poll, 3372 }; 3373 3374 static int bpf_link_alloc_id(struct bpf_link *link) 3375 { 3376 int id; 3377 3378 idr_preload(GFP_KERNEL); 3379 spin_lock_bh(&link_idr_lock); 3380 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC); 3381 spin_unlock_bh(&link_idr_lock); 3382 idr_preload_end(); 3383 3384 return id; 3385 } 3386 3387 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file, 3388 * reserving unused FD and allocating ID from link_idr. This is to be paired 3389 * with bpf_link_settle() to install FD and ID and expose bpf_link to 3390 * user-space, if bpf_link is successfully attached. If not, bpf_link and 3391 * pre-allocated resources are to be freed with bpf_cleanup() call. All the 3392 * transient state is passed around in struct bpf_link_primer. 3393 * This is preferred way to create and initialize bpf_link, especially when 3394 * there are complicated and expensive operations in between creating bpf_link 3395 * itself and attaching it to BPF hook. By using bpf_link_prime() and 3396 * bpf_link_settle() kernel code using bpf_link doesn't have to perform 3397 * expensive (and potentially failing) roll back operations in a rare case 3398 * that file, FD, or ID can't be allocated. 3399 */ 3400 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer) 3401 { 3402 struct file *file; 3403 int fd, id; 3404 3405 fd = get_unused_fd_flags(O_CLOEXEC); 3406 if (fd < 0) 3407 return fd; 3408 3409 3410 id = bpf_link_alloc_id(link); 3411 if (id < 0) { 3412 put_unused_fd(fd); 3413 return id; 3414 } 3415 3416 file = anon_inode_getfile("bpf_link", 3417 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3418 link, O_CLOEXEC); 3419 if (IS_ERR(file)) { 3420 bpf_link_free_id(id); 3421 put_unused_fd(fd); 3422 return PTR_ERR(file); 3423 } 3424 3425 primer->link = link; 3426 primer->file = file; 3427 primer->fd = fd; 3428 primer->id = id; 3429 return 0; 3430 } 3431 3432 int bpf_link_settle(struct bpf_link_primer *primer) 3433 { 3434 /* make bpf_link fetchable by ID */ 3435 spin_lock_bh(&link_idr_lock); 3436 primer->link->id = primer->id; 3437 spin_unlock_bh(&link_idr_lock); 3438 /* make bpf_link fetchable by FD */ 3439 fd_install(primer->fd, primer->file); 3440 /* pass through installed FD */ 3441 return primer->fd; 3442 } 3443 3444 int bpf_link_new_fd(struct bpf_link *link) 3445 { 3446 return anon_inode_getfd("bpf-link", 3447 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops, 3448 link, O_CLOEXEC); 3449 } 3450 3451 struct bpf_link *bpf_link_get_from_fd(u32 ufd) 3452 { 3453 CLASS(fd, f)(ufd); 3454 struct bpf_link *link; 3455 3456 if (fd_empty(f)) 3457 return ERR_PTR(-EBADF); 3458 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll) 3459 return ERR_PTR(-EINVAL); 3460 3461 link = fd_file(f)->private_data; 3462 bpf_link_inc(link); 3463 return link; 3464 } 3465 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); 3466 3467 static void bpf_tracing_link_release(struct bpf_link *link) 3468 { 3469 struct bpf_tracing_link *tr_link = 3470 container_of(link, struct bpf_tracing_link, link.link); 3471 3472 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link, 3473 tr_link->trampoline, 3474 tr_link->tgt_prog)); 3475 3476 bpf_trampoline_put(tr_link->trampoline); 3477 3478 /* tgt_prog is NULL if target is a kernel function */ 3479 if (tr_link->tgt_prog) 3480 bpf_prog_put(tr_link->tgt_prog); 3481 } 3482 3483 static void bpf_tracing_link_dealloc(struct bpf_link *link) 3484 { 3485 struct bpf_tracing_link *tr_link = 3486 container_of(link, struct bpf_tracing_link, link.link); 3487 3488 kfree(tr_link); 3489 } 3490 3491 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link, 3492 struct seq_file *seq) 3493 { 3494 struct bpf_tracing_link *tr_link = 3495 container_of(link, struct bpf_tracing_link, link.link); 3496 u32 target_btf_id, target_obj_id; 3497 3498 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3499 &target_obj_id, &target_btf_id); 3500 seq_printf(seq, 3501 "attach_type:\t%d\n" 3502 "target_obj_id:\t%u\n" 3503 "target_btf_id:\t%u\n" 3504 "cookie:\t%llu\n", 3505 link->attach_type, 3506 target_obj_id, 3507 target_btf_id, 3508 tr_link->link.cookie); 3509 } 3510 3511 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, 3512 struct bpf_link_info *info) 3513 { 3514 struct bpf_tracing_link *tr_link = 3515 container_of(link, struct bpf_tracing_link, link.link); 3516 3517 info->tracing.attach_type = link->attach_type; 3518 info->tracing.cookie = tr_link->link.cookie; 3519 bpf_trampoline_unpack_key(tr_link->trampoline->key, 3520 &info->tracing.target_obj_id, 3521 &info->tracing.target_btf_id); 3522 3523 return 0; 3524 } 3525 3526 static const struct bpf_link_ops bpf_tracing_link_lops = { 3527 .release = bpf_tracing_link_release, 3528 .dealloc = bpf_tracing_link_dealloc, 3529 .show_fdinfo = bpf_tracing_link_show_fdinfo, 3530 .fill_link_info = bpf_tracing_link_fill_link_info, 3531 }; 3532 3533 static int bpf_tracing_prog_attach(struct bpf_prog *prog, 3534 int tgt_prog_fd, 3535 u32 btf_id, 3536 u64 bpf_cookie, 3537 enum bpf_attach_type attach_type) 3538 { 3539 struct bpf_link_primer link_primer; 3540 struct bpf_prog *tgt_prog = NULL; 3541 struct bpf_trampoline *tr = NULL; 3542 struct bpf_tracing_link *link; 3543 u64 key = 0; 3544 int err; 3545 3546 switch (prog->type) { 3547 case BPF_PROG_TYPE_TRACING: 3548 if (prog->expected_attach_type != BPF_TRACE_FENTRY && 3549 prog->expected_attach_type != BPF_TRACE_FEXIT && 3550 prog->expected_attach_type != BPF_MODIFY_RETURN) { 3551 err = -EINVAL; 3552 goto out_put_prog; 3553 } 3554 break; 3555 case BPF_PROG_TYPE_EXT: 3556 if (prog->expected_attach_type != 0) { 3557 err = -EINVAL; 3558 goto out_put_prog; 3559 } 3560 break; 3561 case BPF_PROG_TYPE_LSM: 3562 if (prog->expected_attach_type != BPF_LSM_MAC) { 3563 err = -EINVAL; 3564 goto out_put_prog; 3565 } 3566 break; 3567 default: 3568 err = -EINVAL; 3569 goto out_put_prog; 3570 } 3571 3572 if (!!tgt_prog_fd != !!btf_id) { 3573 err = -EINVAL; 3574 goto out_put_prog; 3575 } 3576 3577 if (tgt_prog_fd) { 3578 /* 3579 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this 3580 * part would be changed to implement the same for 3581 * BPF_PROG_TYPE_TRACING, do not forget to update the way how 3582 * attach_tracing_prog flag is set. 3583 */ 3584 if (prog->type != BPF_PROG_TYPE_EXT) { 3585 err = -EINVAL; 3586 goto out_put_prog; 3587 } 3588 3589 tgt_prog = bpf_prog_get(tgt_prog_fd); 3590 if (IS_ERR(tgt_prog)) { 3591 err = PTR_ERR(tgt_prog); 3592 tgt_prog = NULL; 3593 goto out_put_prog; 3594 } 3595 3596 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); 3597 } 3598 3599 link = kzalloc(sizeof(*link), GFP_USER); 3600 if (!link) { 3601 err = -ENOMEM; 3602 goto out_put_prog; 3603 } 3604 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING, 3605 &bpf_tracing_link_lops, prog, attach_type); 3606 3607 link->link.cookie = bpf_cookie; 3608 3609 mutex_lock(&prog->aux->dst_mutex); 3610 3611 /* There are a few possible cases here: 3612 * 3613 * - if prog->aux->dst_trampoline is set, the program was just loaded 3614 * and not yet attached to anything, so we can use the values stored 3615 * in prog->aux 3616 * 3617 * - if prog->aux->dst_trampoline is NULL, the program has already been 3618 * attached to a target and its initial target was cleared (below) 3619 * 3620 * - if tgt_prog != NULL, the caller specified tgt_prog_fd + 3621 * target_btf_id using the link_create API. 3622 * 3623 * - if tgt_prog == NULL when this function was called using the old 3624 * raw_tracepoint_open API, and we need a target from prog->aux 3625 * 3626 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program 3627 * was detached and is going for re-attachment. 3628 * 3629 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf 3630 * are NULL, then program was already attached and user did not provide 3631 * tgt_prog_fd so we have no way to find out or create trampoline 3632 */ 3633 if (!prog->aux->dst_trampoline && !tgt_prog) { 3634 /* 3635 * Allow re-attach for TRACING and LSM programs. If it's 3636 * currently linked, bpf_trampoline_link_prog will fail. 3637 * EXT programs need to specify tgt_prog_fd, so they 3638 * re-attach in separate code path. 3639 */ 3640 if (prog->type != BPF_PROG_TYPE_TRACING && 3641 prog->type != BPF_PROG_TYPE_LSM) { 3642 err = -EINVAL; 3643 goto out_unlock; 3644 } 3645 /* We can allow re-attach only if we have valid attach_btf. */ 3646 if (!prog->aux->attach_btf) { 3647 err = -EINVAL; 3648 goto out_unlock; 3649 } 3650 btf_id = prog->aux->attach_btf_id; 3651 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); 3652 } 3653 3654 if (!prog->aux->dst_trampoline || 3655 (key && key != prog->aux->dst_trampoline->key)) { 3656 /* If there is no saved target, or the specified target is 3657 * different from the destination specified at load time, we 3658 * need a new trampoline and a check for compatibility 3659 */ 3660 struct bpf_attach_target_info tgt_info = {}; 3661 3662 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id, 3663 &tgt_info); 3664 if (err) 3665 goto out_unlock; 3666 3667 if (tgt_info.tgt_mod) { 3668 module_put(prog->aux->mod); 3669 prog->aux->mod = tgt_info.tgt_mod; 3670 } 3671 3672 tr = bpf_trampoline_get(key, &tgt_info); 3673 if (!tr) { 3674 err = -ENOMEM; 3675 goto out_unlock; 3676 } 3677 } else { 3678 /* The caller didn't specify a target, or the target was the 3679 * same as the destination supplied during program load. This 3680 * means we can reuse the trampoline and reference from program 3681 * load time, and there is no need to allocate a new one. This 3682 * can only happen once for any program, as the saved values in 3683 * prog->aux are cleared below. 3684 */ 3685 tr = prog->aux->dst_trampoline; 3686 tgt_prog = prog->aux->dst_prog; 3687 } 3688 3689 err = bpf_link_prime(&link->link.link, &link_primer); 3690 if (err) 3691 goto out_unlock; 3692 3693 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog); 3694 if (err) { 3695 bpf_link_cleanup(&link_primer); 3696 link = NULL; 3697 goto out_unlock; 3698 } 3699 3700 link->tgt_prog = tgt_prog; 3701 link->trampoline = tr; 3702 3703 /* Always clear the trampoline and target prog from prog->aux to make 3704 * sure the original attach destination is not kept alive after a 3705 * program is (re-)attached to another target. 3706 */ 3707 if (prog->aux->dst_prog && 3708 (tgt_prog_fd || tr != prog->aux->dst_trampoline)) 3709 /* got extra prog ref from syscall, or attaching to different prog */ 3710 bpf_prog_put(prog->aux->dst_prog); 3711 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline) 3712 /* we allocated a new trampoline, so free the old one */ 3713 bpf_trampoline_put(prog->aux->dst_trampoline); 3714 3715 prog->aux->dst_prog = NULL; 3716 prog->aux->dst_trampoline = NULL; 3717 mutex_unlock(&prog->aux->dst_mutex); 3718 3719 return bpf_link_settle(&link_primer); 3720 out_unlock: 3721 if (tr && tr != prog->aux->dst_trampoline) 3722 bpf_trampoline_put(tr); 3723 mutex_unlock(&prog->aux->dst_mutex); 3724 kfree(link); 3725 out_put_prog: 3726 if (tgt_prog_fd && tgt_prog) 3727 bpf_prog_put(tgt_prog); 3728 return err; 3729 } 3730 3731 static void bpf_raw_tp_link_release(struct bpf_link *link) 3732 { 3733 struct bpf_raw_tp_link *raw_tp = 3734 container_of(link, struct bpf_raw_tp_link, link); 3735 3736 bpf_probe_unregister(raw_tp->btp, raw_tp); 3737 bpf_put_raw_tracepoint(raw_tp->btp); 3738 } 3739 3740 static void bpf_raw_tp_link_dealloc(struct bpf_link *link) 3741 { 3742 struct bpf_raw_tp_link *raw_tp = 3743 container_of(link, struct bpf_raw_tp_link, link); 3744 3745 kfree(raw_tp); 3746 } 3747 3748 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link, 3749 struct seq_file *seq) 3750 { 3751 struct bpf_raw_tp_link *raw_tp_link = 3752 container_of(link, struct bpf_raw_tp_link, link); 3753 3754 seq_printf(seq, 3755 "tp_name:\t%s\n" 3756 "cookie:\t%llu\n", 3757 raw_tp_link->btp->tp->name, 3758 raw_tp_link->cookie); 3759 } 3760 3761 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen, 3762 u32 len) 3763 { 3764 if (ulen >= len + 1) { 3765 if (copy_to_user(ubuf, buf, len + 1)) 3766 return -EFAULT; 3767 } else { 3768 char zero = '\0'; 3769 3770 if (copy_to_user(ubuf, buf, ulen - 1)) 3771 return -EFAULT; 3772 if (put_user(zero, ubuf + ulen - 1)) 3773 return -EFAULT; 3774 return -ENOSPC; 3775 } 3776 3777 return 0; 3778 } 3779 3780 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link, 3781 struct bpf_link_info *info) 3782 { 3783 struct bpf_raw_tp_link *raw_tp_link = 3784 container_of(link, struct bpf_raw_tp_link, link); 3785 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name); 3786 const char *tp_name = raw_tp_link->btp->tp->name; 3787 u32 ulen = info->raw_tracepoint.tp_name_len; 3788 size_t tp_len = strlen(tp_name); 3789 3790 if (!ulen ^ !ubuf) 3791 return -EINVAL; 3792 3793 info->raw_tracepoint.tp_name_len = tp_len + 1; 3794 info->raw_tracepoint.cookie = raw_tp_link->cookie; 3795 3796 if (!ubuf) 3797 return 0; 3798 3799 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len); 3800 } 3801 3802 static const struct bpf_link_ops bpf_raw_tp_link_lops = { 3803 .release = bpf_raw_tp_link_release, 3804 .dealloc_deferred = bpf_raw_tp_link_dealloc, 3805 .show_fdinfo = bpf_raw_tp_link_show_fdinfo, 3806 .fill_link_info = bpf_raw_tp_link_fill_link_info, 3807 }; 3808 3809 #ifdef CONFIG_PERF_EVENTS 3810 struct bpf_perf_link { 3811 struct bpf_link link; 3812 struct file *perf_file; 3813 }; 3814 3815 static void bpf_perf_link_release(struct bpf_link *link) 3816 { 3817 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3818 struct perf_event *event = perf_link->perf_file->private_data; 3819 3820 perf_event_free_bpf_prog(event); 3821 fput(perf_link->perf_file); 3822 } 3823 3824 static void bpf_perf_link_dealloc(struct bpf_link *link) 3825 { 3826 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link); 3827 3828 kfree(perf_link); 3829 } 3830 3831 static int bpf_perf_link_fill_common(const struct perf_event *event, 3832 char __user *uname, u32 *ulenp, 3833 u64 *probe_offset, u64 *probe_addr, 3834 u32 *fd_type, unsigned long *missed) 3835 { 3836 const char *buf; 3837 u32 prog_id, ulen; 3838 size_t len; 3839 int err; 3840 3841 ulen = *ulenp; 3842 if (!ulen ^ !uname) 3843 return -EINVAL; 3844 3845 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, 3846 probe_offset, probe_addr, missed); 3847 if (err) 3848 return err; 3849 3850 if (buf) { 3851 len = strlen(buf); 3852 *ulenp = len + 1; 3853 } else { 3854 *ulenp = 1; 3855 } 3856 if (!uname) 3857 return 0; 3858 3859 if (buf) { 3860 err = bpf_copy_to_user(uname, buf, ulen, len); 3861 if (err) 3862 return err; 3863 } else { 3864 char zero = '\0'; 3865 3866 if (put_user(zero, uname)) 3867 return -EFAULT; 3868 } 3869 return 0; 3870 } 3871 3872 #ifdef CONFIG_KPROBE_EVENTS 3873 static int bpf_perf_link_fill_kprobe(const struct perf_event *event, 3874 struct bpf_link_info *info) 3875 { 3876 unsigned long missed; 3877 char __user *uname; 3878 u64 addr, offset; 3879 u32 ulen, type; 3880 int err; 3881 3882 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); 3883 ulen = info->perf_event.kprobe.name_len; 3884 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr, 3885 &type, &missed); 3886 if (err) 3887 return err; 3888 if (type == BPF_FD_TYPE_KRETPROBE) 3889 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE; 3890 else 3891 info->perf_event.type = BPF_PERF_EVENT_KPROBE; 3892 info->perf_event.kprobe.name_len = ulen; 3893 info->perf_event.kprobe.offset = offset; 3894 info->perf_event.kprobe.missed = missed; 3895 if (!kallsyms_show_value(current_cred())) 3896 addr = 0; 3897 info->perf_event.kprobe.addr = addr; 3898 info->perf_event.kprobe.cookie = event->bpf_cookie; 3899 return 0; 3900 } 3901 3902 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event, 3903 struct seq_file *seq) 3904 { 3905 const char *name; 3906 int err; 3907 u32 prog_id, type; 3908 u64 offset, addr; 3909 unsigned long missed; 3910 3911 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 3912 &offset, &addr, &missed); 3913 if (err) 3914 return; 3915 3916 seq_printf(seq, 3917 "name:\t%s\n" 3918 "offset:\t%#llx\n" 3919 "missed:\t%lu\n" 3920 "addr:\t%#llx\n" 3921 "event_type:\t%s\n" 3922 "cookie:\t%llu\n", 3923 name, offset, missed, addr, 3924 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe", 3925 event->bpf_cookie); 3926 } 3927 #endif 3928 3929 #ifdef CONFIG_UPROBE_EVENTS 3930 static int bpf_perf_link_fill_uprobe(const struct perf_event *event, 3931 struct bpf_link_info *info) 3932 { 3933 u64 ref_ctr_offset, offset; 3934 char __user *uname; 3935 u32 ulen, type; 3936 int err; 3937 3938 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); 3939 ulen = info->perf_event.uprobe.name_len; 3940 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset, 3941 &type, NULL); 3942 if (err) 3943 return err; 3944 3945 if (type == BPF_FD_TYPE_URETPROBE) 3946 info->perf_event.type = BPF_PERF_EVENT_URETPROBE; 3947 else 3948 info->perf_event.type = BPF_PERF_EVENT_UPROBE; 3949 info->perf_event.uprobe.name_len = ulen; 3950 info->perf_event.uprobe.offset = offset; 3951 info->perf_event.uprobe.cookie = event->bpf_cookie; 3952 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset; 3953 return 0; 3954 } 3955 3956 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event, 3957 struct seq_file *seq) 3958 { 3959 const char *name; 3960 int err; 3961 u32 prog_id, type; 3962 u64 offset, ref_ctr_offset; 3963 unsigned long missed; 3964 3965 err = bpf_get_perf_event_info(event, &prog_id, &type, &name, 3966 &offset, &ref_ctr_offset, &missed); 3967 if (err) 3968 return; 3969 3970 seq_printf(seq, 3971 "name:\t%s\n" 3972 "offset:\t%#llx\n" 3973 "ref_ctr_offset:\t%#llx\n" 3974 "event_type:\t%s\n" 3975 "cookie:\t%llu\n", 3976 name, offset, ref_ctr_offset, 3977 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe", 3978 event->bpf_cookie); 3979 } 3980 #endif 3981 3982 static int bpf_perf_link_fill_probe(const struct perf_event *event, 3983 struct bpf_link_info *info) 3984 { 3985 #ifdef CONFIG_KPROBE_EVENTS 3986 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 3987 return bpf_perf_link_fill_kprobe(event, info); 3988 #endif 3989 #ifdef CONFIG_UPROBE_EVENTS 3990 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 3991 return bpf_perf_link_fill_uprobe(event, info); 3992 #endif 3993 return -EOPNOTSUPP; 3994 } 3995 3996 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, 3997 struct bpf_link_info *info) 3998 { 3999 char __user *uname; 4000 u32 ulen; 4001 int err; 4002 4003 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); 4004 ulen = info->perf_event.tracepoint.name_len; 4005 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL); 4006 if (err) 4007 return err; 4008 4009 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; 4010 info->perf_event.tracepoint.name_len = ulen; 4011 info->perf_event.tracepoint.cookie = event->bpf_cookie; 4012 return 0; 4013 } 4014 4015 static int bpf_perf_link_fill_perf_event(const struct perf_event *event, 4016 struct bpf_link_info *info) 4017 { 4018 info->perf_event.event.type = event->attr.type; 4019 info->perf_event.event.config = event->attr.config; 4020 info->perf_event.event.cookie = event->bpf_cookie; 4021 info->perf_event.type = BPF_PERF_EVENT_EVENT; 4022 return 0; 4023 } 4024 4025 static int bpf_perf_link_fill_link_info(const struct bpf_link *link, 4026 struct bpf_link_info *info) 4027 { 4028 struct bpf_perf_link *perf_link; 4029 const struct perf_event *event; 4030 4031 perf_link = container_of(link, struct bpf_perf_link, link); 4032 event = perf_get_event(perf_link->perf_file); 4033 if (IS_ERR(event)) 4034 return PTR_ERR(event); 4035 4036 switch (event->prog->type) { 4037 case BPF_PROG_TYPE_PERF_EVENT: 4038 return bpf_perf_link_fill_perf_event(event, info); 4039 case BPF_PROG_TYPE_TRACEPOINT: 4040 return bpf_perf_link_fill_tracepoint(event, info); 4041 case BPF_PROG_TYPE_KPROBE: 4042 return bpf_perf_link_fill_probe(event, info); 4043 default: 4044 return -EOPNOTSUPP; 4045 } 4046 } 4047 4048 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event, 4049 struct seq_file *seq) 4050 { 4051 seq_printf(seq, 4052 "type:\t%u\n" 4053 "config:\t%llu\n" 4054 "event_type:\t%s\n" 4055 "cookie:\t%llu\n", 4056 event->attr.type, event->attr.config, 4057 "event", event->bpf_cookie); 4058 } 4059 4060 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event, 4061 struct seq_file *seq) 4062 { 4063 int err; 4064 const char *name; 4065 u32 prog_id; 4066 4067 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL, 4068 NULL, NULL); 4069 if (err) 4070 return; 4071 4072 seq_printf(seq, 4073 "tp_name:\t%s\n" 4074 "event_type:\t%s\n" 4075 "cookie:\t%llu\n", 4076 name, "tracepoint", event->bpf_cookie); 4077 } 4078 4079 static void bpf_probe_link_show_fdinfo(const struct perf_event *event, 4080 struct seq_file *seq) 4081 { 4082 #ifdef CONFIG_KPROBE_EVENTS 4083 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE) 4084 return bpf_perf_link_fdinfo_kprobe(event, seq); 4085 #endif 4086 4087 #ifdef CONFIG_UPROBE_EVENTS 4088 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE) 4089 return bpf_perf_link_fdinfo_uprobe(event, seq); 4090 #endif 4091 } 4092 4093 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link, 4094 struct seq_file *seq) 4095 { 4096 struct bpf_perf_link *perf_link; 4097 const struct perf_event *event; 4098 4099 perf_link = container_of(link, struct bpf_perf_link, link); 4100 event = perf_get_event(perf_link->perf_file); 4101 if (IS_ERR(event)) 4102 return; 4103 4104 switch (event->prog->type) { 4105 case BPF_PROG_TYPE_PERF_EVENT: 4106 return bpf_perf_event_link_show_fdinfo(event, seq); 4107 case BPF_PROG_TYPE_TRACEPOINT: 4108 return bpf_tracepoint_link_show_fdinfo(event, seq); 4109 case BPF_PROG_TYPE_KPROBE: 4110 return bpf_probe_link_show_fdinfo(event, seq); 4111 default: 4112 return; 4113 } 4114 } 4115 4116 static const struct bpf_link_ops bpf_perf_link_lops = { 4117 .release = bpf_perf_link_release, 4118 .dealloc = bpf_perf_link_dealloc, 4119 .fill_link_info = bpf_perf_link_fill_link_info, 4120 .show_fdinfo = bpf_perf_link_show_fdinfo, 4121 }; 4122 4123 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4124 { 4125 struct bpf_link_primer link_primer; 4126 struct bpf_perf_link *link; 4127 struct perf_event *event; 4128 struct file *perf_file; 4129 int err; 4130 4131 if (attr->link_create.flags) 4132 return -EINVAL; 4133 4134 perf_file = perf_event_get(attr->link_create.target_fd); 4135 if (IS_ERR(perf_file)) 4136 return PTR_ERR(perf_file); 4137 4138 link = kzalloc(sizeof(*link), GFP_USER); 4139 if (!link) { 4140 err = -ENOMEM; 4141 goto out_put_file; 4142 } 4143 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog, 4144 attr->link_create.attach_type); 4145 link->perf_file = perf_file; 4146 4147 err = bpf_link_prime(&link->link, &link_primer); 4148 if (err) { 4149 kfree(link); 4150 goto out_put_file; 4151 } 4152 4153 event = perf_file->private_data; 4154 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie); 4155 if (err) { 4156 bpf_link_cleanup(&link_primer); 4157 goto out_put_file; 4158 } 4159 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */ 4160 bpf_prog_inc(prog); 4161 4162 return bpf_link_settle(&link_primer); 4163 4164 out_put_file: 4165 fput(perf_file); 4166 return err; 4167 } 4168 #else 4169 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) 4170 { 4171 return -EOPNOTSUPP; 4172 } 4173 #endif /* CONFIG_PERF_EVENTS */ 4174 4175 static int bpf_raw_tp_link_attach(struct bpf_prog *prog, 4176 const char __user *user_tp_name, u64 cookie, 4177 enum bpf_attach_type attach_type) 4178 { 4179 struct bpf_link_primer link_primer; 4180 struct bpf_raw_tp_link *link; 4181 struct bpf_raw_event_map *btp; 4182 const char *tp_name; 4183 char buf[128]; 4184 int err; 4185 4186 switch (prog->type) { 4187 case BPF_PROG_TYPE_TRACING: 4188 case BPF_PROG_TYPE_EXT: 4189 case BPF_PROG_TYPE_LSM: 4190 if (user_tp_name) 4191 /* The attach point for this category of programs 4192 * should be specified via btf_id during program load. 4193 */ 4194 return -EINVAL; 4195 if (prog->type == BPF_PROG_TYPE_TRACING && 4196 prog->expected_attach_type == BPF_TRACE_RAW_TP) { 4197 tp_name = prog->aux->attach_func_name; 4198 break; 4199 } 4200 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type); 4201 case BPF_PROG_TYPE_RAW_TRACEPOINT: 4202 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 4203 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0) 4204 return -EFAULT; 4205 buf[sizeof(buf) - 1] = 0; 4206 tp_name = buf; 4207 break; 4208 default: 4209 return -EINVAL; 4210 } 4211 4212 btp = bpf_get_raw_tracepoint(tp_name); 4213 if (!btp) 4214 return -ENOENT; 4215 4216 link = kzalloc(sizeof(*link), GFP_USER); 4217 if (!link) { 4218 err = -ENOMEM; 4219 goto out_put_btp; 4220 } 4221 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT, 4222 &bpf_raw_tp_link_lops, prog, attach_type, 4223 tracepoint_is_faultable(btp->tp)); 4224 link->btp = btp; 4225 link->cookie = cookie; 4226 4227 err = bpf_link_prime(&link->link, &link_primer); 4228 if (err) { 4229 kfree(link); 4230 goto out_put_btp; 4231 } 4232 4233 err = bpf_probe_register(link->btp, link); 4234 if (err) { 4235 bpf_link_cleanup(&link_primer); 4236 goto out_put_btp; 4237 } 4238 4239 return bpf_link_settle(&link_primer); 4240 4241 out_put_btp: 4242 bpf_put_raw_tracepoint(btp); 4243 return err; 4244 } 4245 4246 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie 4247 4248 static int bpf_raw_tracepoint_open(const union bpf_attr *attr) 4249 { 4250 struct bpf_prog *prog; 4251 void __user *tp_name; 4252 __u64 cookie; 4253 int fd; 4254 4255 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN)) 4256 return -EINVAL; 4257 4258 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); 4259 if (IS_ERR(prog)) 4260 return PTR_ERR(prog); 4261 4262 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name); 4263 cookie = attr->raw_tracepoint.cookie; 4264 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type); 4265 if (fd < 0) 4266 bpf_prog_put(prog); 4267 return fd; 4268 } 4269 4270 static enum bpf_prog_type 4271 attach_type_to_prog_type(enum bpf_attach_type attach_type) 4272 { 4273 switch (attach_type) { 4274 case BPF_CGROUP_INET_INGRESS: 4275 case BPF_CGROUP_INET_EGRESS: 4276 return BPF_PROG_TYPE_CGROUP_SKB; 4277 case BPF_CGROUP_INET_SOCK_CREATE: 4278 case BPF_CGROUP_INET_SOCK_RELEASE: 4279 case BPF_CGROUP_INET4_POST_BIND: 4280 case BPF_CGROUP_INET6_POST_BIND: 4281 return BPF_PROG_TYPE_CGROUP_SOCK; 4282 case BPF_CGROUP_INET4_BIND: 4283 case BPF_CGROUP_INET6_BIND: 4284 case BPF_CGROUP_INET4_CONNECT: 4285 case BPF_CGROUP_INET6_CONNECT: 4286 case BPF_CGROUP_UNIX_CONNECT: 4287 case BPF_CGROUP_INET4_GETPEERNAME: 4288 case BPF_CGROUP_INET6_GETPEERNAME: 4289 case BPF_CGROUP_UNIX_GETPEERNAME: 4290 case BPF_CGROUP_INET4_GETSOCKNAME: 4291 case BPF_CGROUP_INET6_GETSOCKNAME: 4292 case BPF_CGROUP_UNIX_GETSOCKNAME: 4293 case BPF_CGROUP_UDP4_SENDMSG: 4294 case BPF_CGROUP_UDP6_SENDMSG: 4295 case BPF_CGROUP_UNIX_SENDMSG: 4296 case BPF_CGROUP_UDP4_RECVMSG: 4297 case BPF_CGROUP_UDP6_RECVMSG: 4298 case BPF_CGROUP_UNIX_RECVMSG: 4299 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR; 4300 case BPF_CGROUP_SOCK_OPS: 4301 return BPF_PROG_TYPE_SOCK_OPS; 4302 case BPF_CGROUP_DEVICE: 4303 return BPF_PROG_TYPE_CGROUP_DEVICE; 4304 case BPF_SK_MSG_VERDICT: 4305 return BPF_PROG_TYPE_SK_MSG; 4306 case BPF_SK_SKB_STREAM_PARSER: 4307 case BPF_SK_SKB_STREAM_VERDICT: 4308 case BPF_SK_SKB_VERDICT: 4309 return BPF_PROG_TYPE_SK_SKB; 4310 case BPF_LIRC_MODE2: 4311 return BPF_PROG_TYPE_LIRC_MODE2; 4312 case BPF_FLOW_DISSECTOR: 4313 return BPF_PROG_TYPE_FLOW_DISSECTOR; 4314 case BPF_CGROUP_SYSCTL: 4315 return BPF_PROG_TYPE_CGROUP_SYSCTL; 4316 case BPF_CGROUP_GETSOCKOPT: 4317 case BPF_CGROUP_SETSOCKOPT: 4318 return BPF_PROG_TYPE_CGROUP_SOCKOPT; 4319 case BPF_TRACE_ITER: 4320 case BPF_TRACE_RAW_TP: 4321 case BPF_TRACE_FENTRY: 4322 case BPF_TRACE_FEXIT: 4323 case BPF_MODIFY_RETURN: 4324 return BPF_PROG_TYPE_TRACING; 4325 case BPF_LSM_MAC: 4326 return BPF_PROG_TYPE_LSM; 4327 case BPF_SK_LOOKUP: 4328 return BPF_PROG_TYPE_SK_LOOKUP; 4329 case BPF_XDP: 4330 return BPF_PROG_TYPE_XDP; 4331 case BPF_LSM_CGROUP: 4332 return BPF_PROG_TYPE_LSM; 4333 case BPF_TCX_INGRESS: 4334 case BPF_TCX_EGRESS: 4335 case BPF_NETKIT_PRIMARY: 4336 case BPF_NETKIT_PEER: 4337 return BPF_PROG_TYPE_SCHED_CLS; 4338 default: 4339 return BPF_PROG_TYPE_UNSPEC; 4340 } 4341 } 4342 4343 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 4344 enum bpf_attach_type attach_type) 4345 { 4346 enum bpf_prog_type ptype; 4347 4348 switch (prog->type) { 4349 case BPF_PROG_TYPE_CGROUP_SOCK: 4350 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4351 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4352 case BPF_PROG_TYPE_SK_LOOKUP: 4353 return attach_type == prog->expected_attach_type ? 0 : -EINVAL; 4354 case BPF_PROG_TYPE_CGROUP_SKB: 4355 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN)) 4356 /* cg-skb progs can be loaded by unpriv user. 4357 * check permissions at attach time. 4358 */ 4359 return -EPERM; 4360 4361 ptype = attach_type_to_prog_type(attach_type); 4362 if (prog->type != ptype) 4363 return -EINVAL; 4364 4365 return prog->enforce_expected_attach_type && 4366 prog->expected_attach_type != attach_type ? 4367 -EINVAL : 0; 4368 case BPF_PROG_TYPE_EXT: 4369 return 0; 4370 case BPF_PROG_TYPE_NETFILTER: 4371 if (attach_type != BPF_NETFILTER) 4372 return -EINVAL; 4373 return 0; 4374 case BPF_PROG_TYPE_PERF_EVENT: 4375 case BPF_PROG_TYPE_TRACEPOINT: 4376 if (attach_type != BPF_PERF_EVENT) 4377 return -EINVAL; 4378 return 0; 4379 case BPF_PROG_TYPE_KPROBE: 4380 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI && 4381 attach_type != BPF_TRACE_KPROBE_MULTI) 4382 return -EINVAL; 4383 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION && 4384 attach_type != BPF_TRACE_KPROBE_SESSION) 4385 return -EINVAL; 4386 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI && 4387 attach_type != BPF_TRACE_UPROBE_MULTI) 4388 return -EINVAL; 4389 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION && 4390 attach_type != BPF_TRACE_UPROBE_SESSION) 4391 return -EINVAL; 4392 if (attach_type != BPF_PERF_EVENT && 4393 attach_type != BPF_TRACE_KPROBE_MULTI && 4394 attach_type != BPF_TRACE_KPROBE_SESSION && 4395 attach_type != BPF_TRACE_UPROBE_MULTI && 4396 attach_type != BPF_TRACE_UPROBE_SESSION) 4397 return -EINVAL; 4398 return 0; 4399 case BPF_PROG_TYPE_SCHED_CLS: 4400 if (attach_type != BPF_TCX_INGRESS && 4401 attach_type != BPF_TCX_EGRESS && 4402 attach_type != BPF_NETKIT_PRIMARY && 4403 attach_type != BPF_NETKIT_PEER) 4404 return -EINVAL; 4405 return 0; 4406 default: 4407 ptype = attach_type_to_prog_type(attach_type); 4408 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) 4409 return -EINVAL; 4410 return 0; 4411 } 4412 } 4413 4414 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype, 4415 bool check_atype) 4416 { 4417 switch (ptype) { 4418 case BPF_PROG_TYPE_CGROUP_DEVICE: 4419 case BPF_PROG_TYPE_CGROUP_SKB: 4420 case BPF_PROG_TYPE_CGROUP_SOCK: 4421 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4422 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4423 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4424 case BPF_PROG_TYPE_SOCK_OPS: 4425 return true; 4426 case BPF_PROG_TYPE_LSM: 4427 return check_atype ? atype == BPF_LSM_CGROUP : true; 4428 default: 4429 return false; 4430 } 4431 } 4432 4433 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision 4434 4435 #define BPF_F_ATTACH_MASK_BASE \ 4436 (BPF_F_ALLOW_OVERRIDE | \ 4437 BPF_F_ALLOW_MULTI | \ 4438 BPF_F_REPLACE | \ 4439 BPF_F_PREORDER) 4440 4441 #define BPF_F_ATTACH_MASK_MPROG \ 4442 (BPF_F_REPLACE | \ 4443 BPF_F_BEFORE | \ 4444 BPF_F_AFTER | \ 4445 BPF_F_ID | \ 4446 BPF_F_LINK) 4447 4448 static int bpf_prog_attach(const union bpf_attr *attr) 4449 { 4450 enum bpf_prog_type ptype; 4451 struct bpf_prog *prog; 4452 int ret; 4453 4454 if (CHECK_ATTR(BPF_PROG_ATTACH)) 4455 return -EINVAL; 4456 4457 ptype = attach_type_to_prog_type(attr->attach_type); 4458 if (ptype == BPF_PROG_TYPE_UNSPEC) 4459 return -EINVAL; 4460 if (bpf_mprog_supported(ptype)) { 4461 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4462 return -EINVAL; 4463 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4464 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG)) 4465 return -EINVAL; 4466 } else { 4467 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE) 4468 return -EINVAL; 4469 if (attr->relative_fd || 4470 attr->expected_revision) 4471 return -EINVAL; 4472 } 4473 4474 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4475 if (IS_ERR(prog)) 4476 return PTR_ERR(prog); 4477 4478 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { 4479 bpf_prog_put(prog); 4480 return -EINVAL; 4481 } 4482 4483 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) { 4484 ret = cgroup_bpf_prog_attach(attr, ptype, prog); 4485 goto out; 4486 } 4487 4488 switch (ptype) { 4489 case BPF_PROG_TYPE_SK_SKB: 4490 case BPF_PROG_TYPE_SK_MSG: 4491 ret = sock_map_get_from_fd(attr, prog); 4492 break; 4493 case BPF_PROG_TYPE_LIRC_MODE2: 4494 ret = lirc_prog_attach(attr, prog); 4495 break; 4496 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4497 ret = netns_bpf_prog_attach(attr, prog); 4498 break; 4499 case BPF_PROG_TYPE_SCHED_CLS: 4500 if (attr->attach_type == BPF_TCX_INGRESS || 4501 attr->attach_type == BPF_TCX_EGRESS) 4502 ret = tcx_prog_attach(attr, prog); 4503 else 4504 ret = netkit_prog_attach(attr, prog); 4505 break; 4506 default: 4507 ret = -EINVAL; 4508 } 4509 out: 4510 if (ret) 4511 bpf_prog_put(prog); 4512 return ret; 4513 } 4514 4515 #define BPF_PROG_DETACH_LAST_FIELD expected_revision 4516 4517 static int bpf_prog_detach(const union bpf_attr *attr) 4518 { 4519 struct bpf_prog *prog = NULL; 4520 enum bpf_prog_type ptype; 4521 int ret; 4522 4523 if (CHECK_ATTR(BPF_PROG_DETACH)) 4524 return -EINVAL; 4525 4526 ptype = attach_type_to_prog_type(attr->attach_type); 4527 if (bpf_mprog_supported(ptype)) { 4528 if (ptype == BPF_PROG_TYPE_UNSPEC) 4529 return -EINVAL; 4530 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG) 4531 return -EINVAL; 4532 if (attr->attach_bpf_fd) { 4533 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); 4534 if (IS_ERR(prog)) 4535 return PTR_ERR(prog); 4536 } 4537 } else if (is_cgroup_prog_type(ptype, 0, false)) { 4538 if (attr->attach_flags || attr->relative_fd) 4539 return -EINVAL; 4540 } else if (attr->attach_flags || 4541 attr->relative_fd || 4542 attr->expected_revision) { 4543 return -EINVAL; 4544 } 4545 4546 switch (ptype) { 4547 case BPF_PROG_TYPE_SK_MSG: 4548 case BPF_PROG_TYPE_SK_SKB: 4549 ret = sock_map_prog_detach(attr, ptype); 4550 break; 4551 case BPF_PROG_TYPE_LIRC_MODE2: 4552 ret = lirc_prog_detach(attr); 4553 break; 4554 case BPF_PROG_TYPE_FLOW_DISSECTOR: 4555 ret = netns_bpf_prog_detach(attr, ptype); 4556 break; 4557 case BPF_PROG_TYPE_CGROUP_DEVICE: 4558 case BPF_PROG_TYPE_CGROUP_SKB: 4559 case BPF_PROG_TYPE_CGROUP_SOCK: 4560 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 4561 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 4562 case BPF_PROG_TYPE_CGROUP_SYSCTL: 4563 case BPF_PROG_TYPE_SOCK_OPS: 4564 case BPF_PROG_TYPE_LSM: 4565 ret = cgroup_bpf_prog_detach(attr, ptype); 4566 break; 4567 case BPF_PROG_TYPE_SCHED_CLS: 4568 if (attr->attach_type == BPF_TCX_INGRESS || 4569 attr->attach_type == BPF_TCX_EGRESS) 4570 ret = tcx_prog_detach(attr, prog); 4571 else 4572 ret = netkit_prog_detach(attr, prog); 4573 break; 4574 default: 4575 ret = -EINVAL; 4576 } 4577 4578 if (prog) 4579 bpf_prog_put(prog); 4580 return ret; 4581 } 4582 4583 #define BPF_PROG_QUERY_LAST_FIELD query.revision 4584 4585 static int bpf_prog_query(const union bpf_attr *attr, 4586 union bpf_attr __user *uattr) 4587 { 4588 if (!bpf_net_capable()) 4589 return -EPERM; 4590 if (CHECK_ATTR(BPF_PROG_QUERY)) 4591 return -EINVAL; 4592 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) 4593 return -EINVAL; 4594 4595 switch (attr->query.attach_type) { 4596 case BPF_CGROUP_INET_INGRESS: 4597 case BPF_CGROUP_INET_EGRESS: 4598 case BPF_CGROUP_INET_SOCK_CREATE: 4599 case BPF_CGROUP_INET_SOCK_RELEASE: 4600 case BPF_CGROUP_INET4_BIND: 4601 case BPF_CGROUP_INET6_BIND: 4602 case BPF_CGROUP_INET4_POST_BIND: 4603 case BPF_CGROUP_INET6_POST_BIND: 4604 case BPF_CGROUP_INET4_CONNECT: 4605 case BPF_CGROUP_INET6_CONNECT: 4606 case BPF_CGROUP_UNIX_CONNECT: 4607 case BPF_CGROUP_INET4_GETPEERNAME: 4608 case BPF_CGROUP_INET6_GETPEERNAME: 4609 case BPF_CGROUP_UNIX_GETPEERNAME: 4610 case BPF_CGROUP_INET4_GETSOCKNAME: 4611 case BPF_CGROUP_INET6_GETSOCKNAME: 4612 case BPF_CGROUP_UNIX_GETSOCKNAME: 4613 case BPF_CGROUP_UDP4_SENDMSG: 4614 case BPF_CGROUP_UDP6_SENDMSG: 4615 case BPF_CGROUP_UNIX_SENDMSG: 4616 case BPF_CGROUP_UDP4_RECVMSG: 4617 case BPF_CGROUP_UDP6_RECVMSG: 4618 case BPF_CGROUP_UNIX_RECVMSG: 4619 case BPF_CGROUP_SOCK_OPS: 4620 case BPF_CGROUP_DEVICE: 4621 case BPF_CGROUP_SYSCTL: 4622 case BPF_CGROUP_GETSOCKOPT: 4623 case BPF_CGROUP_SETSOCKOPT: 4624 case BPF_LSM_CGROUP: 4625 return cgroup_bpf_prog_query(attr, uattr); 4626 case BPF_LIRC_MODE2: 4627 return lirc_prog_query(attr, uattr); 4628 case BPF_FLOW_DISSECTOR: 4629 case BPF_SK_LOOKUP: 4630 return netns_bpf_prog_query(attr, uattr); 4631 case BPF_SK_SKB_STREAM_PARSER: 4632 case BPF_SK_SKB_STREAM_VERDICT: 4633 case BPF_SK_MSG_VERDICT: 4634 case BPF_SK_SKB_VERDICT: 4635 return sock_map_bpf_prog_query(attr, uattr); 4636 case BPF_TCX_INGRESS: 4637 case BPF_TCX_EGRESS: 4638 return tcx_prog_query(attr, uattr); 4639 case BPF_NETKIT_PRIMARY: 4640 case BPF_NETKIT_PEER: 4641 return netkit_prog_query(attr, uattr); 4642 default: 4643 return -EINVAL; 4644 } 4645 } 4646 4647 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size 4648 4649 static int bpf_prog_test_run(const union bpf_attr *attr, 4650 union bpf_attr __user *uattr) 4651 { 4652 struct bpf_prog *prog; 4653 int ret = -ENOTSUPP; 4654 4655 if (CHECK_ATTR(BPF_PROG_TEST_RUN)) 4656 return -EINVAL; 4657 4658 if ((attr->test.ctx_size_in && !attr->test.ctx_in) || 4659 (!attr->test.ctx_size_in && attr->test.ctx_in)) 4660 return -EINVAL; 4661 4662 if ((attr->test.ctx_size_out && !attr->test.ctx_out) || 4663 (!attr->test.ctx_size_out && attr->test.ctx_out)) 4664 return -EINVAL; 4665 4666 prog = bpf_prog_get(attr->test.prog_fd); 4667 if (IS_ERR(prog)) 4668 return PTR_ERR(prog); 4669 4670 if (prog->aux->ops->test_run) 4671 ret = prog->aux->ops->test_run(prog, attr, uattr); 4672 4673 bpf_prog_put(prog); 4674 return ret; 4675 } 4676 4677 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id 4678 4679 static int bpf_obj_get_next_id(const union bpf_attr *attr, 4680 union bpf_attr __user *uattr, 4681 struct idr *idr, 4682 spinlock_t *lock) 4683 { 4684 u32 next_id = attr->start_id; 4685 int err = 0; 4686 4687 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) 4688 return -EINVAL; 4689 4690 if (!capable(CAP_SYS_ADMIN)) 4691 return -EPERM; 4692 4693 next_id++; 4694 spin_lock_bh(lock); 4695 if (!idr_get_next(idr, &next_id)) 4696 err = -ENOENT; 4697 spin_unlock_bh(lock); 4698 4699 if (!err) 4700 err = put_user(next_id, &uattr->next_id); 4701 4702 return err; 4703 } 4704 4705 struct bpf_map *bpf_map_get_curr_or_next(u32 *id) 4706 { 4707 struct bpf_map *map; 4708 4709 spin_lock_bh(&map_idr_lock); 4710 again: 4711 map = idr_get_next(&map_idr, id); 4712 if (map) { 4713 map = __bpf_map_inc_not_zero(map, false); 4714 if (IS_ERR(map)) { 4715 (*id)++; 4716 goto again; 4717 } 4718 } 4719 spin_unlock_bh(&map_idr_lock); 4720 4721 return map; 4722 } 4723 4724 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id) 4725 { 4726 struct bpf_prog *prog; 4727 4728 spin_lock_bh(&prog_idr_lock); 4729 again: 4730 prog = idr_get_next(&prog_idr, id); 4731 if (prog) { 4732 prog = bpf_prog_inc_not_zero(prog); 4733 if (IS_ERR(prog)) { 4734 (*id)++; 4735 goto again; 4736 } 4737 } 4738 spin_unlock_bh(&prog_idr_lock); 4739 4740 return prog; 4741 } 4742 4743 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id 4744 4745 struct bpf_prog *bpf_prog_by_id(u32 id) 4746 { 4747 struct bpf_prog *prog; 4748 4749 if (!id) 4750 return ERR_PTR(-ENOENT); 4751 4752 spin_lock_bh(&prog_idr_lock); 4753 prog = idr_find(&prog_idr, id); 4754 if (prog) 4755 prog = bpf_prog_inc_not_zero(prog); 4756 else 4757 prog = ERR_PTR(-ENOENT); 4758 spin_unlock_bh(&prog_idr_lock); 4759 return prog; 4760 } 4761 4762 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) 4763 { 4764 struct bpf_prog *prog; 4765 u32 id = attr->prog_id; 4766 int fd; 4767 4768 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) 4769 return -EINVAL; 4770 4771 if (!capable(CAP_SYS_ADMIN)) 4772 return -EPERM; 4773 4774 prog = bpf_prog_by_id(id); 4775 if (IS_ERR(prog)) 4776 return PTR_ERR(prog); 4777 4778 fd = bpf_prog_new_fd(prog); 4779 if (fd < 0) 4780 bpf_prog_put(prog); 4781 4782 return fd; 4783 } 4784 4785 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags 4786 4787 static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 4788 { 4789 struct bpf_map *map; 4790 u32 id = attr->map_id; 4791 int f_flags; 4792 int fd; 4793 4794 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || 4795 attr->open_flags & ~BPF_OBJ_FLAG_MASK) 4796 return -EINVAL; 4797 4798 if (!capable(CAP_SYS_ADMIN)) 4799 return -EPERM; 4800 4801 f_flags = bpf_get_file_flag(attr->open_flags); 4802 if (f_flags < 0) 4803 return f_flags; 4804 4805 spin_lock_bh(&map_idr_lock); 4806 map = idr_find(&map_idr, id); 4807 if (map) 4808 map = __bpf_map_inc_not_zero(map, true); 4809 else 4810 map = ERR_PTR(-ENOENT); 4811 spin_unlock_bh(&map_idr_lock); 4812 4813 if (IS_ERR(map)) 4814 return PTR_ERR(map); 4815 4816 fd = bpf_map_new_fd(map, f_flags); 4817 if (fd < 0) 4818 bpf_map_put_with_uref(map); 4819 4820 return fd; 4821 } 4822 4823 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, 4824 unsigned long addr, u32 *off, 4825 u32 *type) 4826 { 4827 const struct bpf_map *map; 4828 int i; 4829 4830 mutex_lock(&prog->aux->used_maps_mutex); 4831 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { 4832 map = prog->aux->used_maps[i]; 4833 if (map == (void *)addr) { 4834 *type = BPF_PSEUDO_MAP_FD; 4835 goto out; 4836 } 4837 if (!map->ops->map_direct_value_meta) 4838 continue; 4839 if (!map->ops->map_direct_value_meta(map, addr, off)) { 4840 *type = BPF_PSEUDO_MAP_VALUE; 4841 goto out; 4842 } 4843 } 4844 map = NULL; 4845 4846 out: 4847 mutex_unlock(&prog->aux->used_maps_mutex); 4848 return map; 4849 } 4850 4851 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, 4852 const struct cred *f_cred) 4853 { 4854 const struct bpf_map *map; 4855 struct bpf_insn *insns; 4856 u32 off, type; 4857 u64 imm; 4858 u8 code; 4859 int i; 4860 4861 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), 4862 GFP_USER); 4863 if (!insns) 4864 return insns; 4865 4866 for (i = 0; i < prog->len; i++) { 4867 code = insns[i].code; 4868 4869 if (code == (BPF_JMP | BPF_TAIL_CALL)) { 4870 insns[i].code = BPF_JMP | BPF_CALL; 4871 insns[i].imm = BPF_FUNC_tail_call; 4872 /* fall-through */ 4873 } 4874 if (code == (BPF_JMP | BPF_CALL) || 4875 code == (BPF_JMP | BPF_CALL_ARGS)) { 4876 if (code == (BPF_JMP | BPF_CALL_ARGS)) 4877 insns[i].code = BPF_JMP | BPF_CALL; 4878 if (!bpf_dump_raw_ok(f_cred)) 4879 insns[i].imm = 0; 4880 continue; 4881 } 4882 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) { 4883 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM; 4884 continue; 4885 } 4886 4887 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX || 4888 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) { 4889 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM; 4890 continue; 4891 } 4892 4893 if (code != (BPF_LD | BPF_IMM | BPF_DW)) 4894 continue; 4895 4896 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; 4897 map = bpf_map_from_imm(prog, imm, &off, &type); 4898 if (map) { 4899 insns[i].src_reg = type; 4900 insns[i].imm = map->id; 4901 insns[i + 1].imm = off; 4902 continue; 4903 } 4904 } 4905 4906 return insns; 4907 } 4908 4909 static int set_info_rec_size(struct bpf_prog_info *info) 4910 { 4911 /* 4912 * Ensure info.*_rec_size is the same as kernel expected size 4913 * 4914 * or 4915 * 4916 * Only allow zero *_rec_size if both _rec_size and _cnt are 4917 * zero. In this case, the kernel will set the expected 4918 * _rec_size back to the info. 4919 */ 4920 4921 if ((info->nr_func_info || info->func_info_rec_size) && 4922 info->func_info_rec_size != sizeof(struct bpf_func_info)) 4923 return -EINVAL; 4924 4925 if ((info->nr_line_info || info->line_info_rec_size) && 4926 info->line_info_rec_size != sizeof(struct bpf_line_info)) 4927 return -EINVAL; 4928 4929 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) && 4930 info->jited_line_info_rec_size != sizeof(__u64)) 4931 return -EINVAL; 4932 4933 info->func_info_rec_size = sizeof(struct bpf_func_info); 4934 info->line_info_rec_size = sizeof(struct bpf_line_info); 4935 info->jited_line_info_rec_size = sizeof(__u64); 4936 4937 return 0; 4938 } 4939 4940 static int bpf_prog_get_info_by_fd(struct file *file, 4941 struct bpf_prog *prog, 4942 const union bpf_attr *attr, 4943 union bpf_attr __user *uattr) 4944 { 4945 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); 4946 struct btf *attach_btf = bpf_prog_get_target_btf(prog); 4947 struct bpf_prog_info info; 4948 u32 info_len = attr->info.info_len; 4949 struct bpf_prog_kstats stats; 4950 char __user *uinsns; 4951 u32 ulen; 4952 int err; 4953 4954 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 4955 if (err) 4956 return err; 4957 info_len = min_t(u32, sizeof(info), info_len); 4958 4959 memset(&info, 0, sizeof(info)); 4960 if (copy_from_user(&info, uinfo, info_len)) 4961 return -EFAULT; 4962 4963 info.type = prog->type; 4964 info.id = prog->aux->id; 4965 info.load_time = prog->aux->load_time; 4966 info.created_by_uid = from_kuid_munged(current_user_ns(), 4967 prog->aux->user->uid); 4968 info.gpl_compatible = prog->gpl_compatible; 4969 4970 memcpy(info.tag, prog->tag, sizeof(prog->tag)); 4971 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); 4972 4973 mutex_lock(&prog->aux->used_maps_mutex); 4974 ulen = info.nr_map_ids; 4975 info.nr_map_ids = prog->aux->used_map_cnt; 4976 ulen = min_t(u32, info.nr_map_ids, ulen); 4977 if (ulen) { 4978 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); 4979 u32 i; 4980 4981 for (i = 0; i < ulen; i++) 4982 if (put_user(prog->aux->used_maps[i]->id, 4983 &user_map_ids[i])) { 4984 mutex_unlock(&prog->aux->used_maps_mutex); 4985 return -EFAULT; 4986 } 4987 } 4988 mutex_unlock(&prog->aux->used_maps_mutex); 4989 4990 err = set_info_rec_size(&info); 4991 if (err) 4992 return err; 4993 4994 bpf_prog_get_stats(prog, &stats); 4995 info.run_time_ns = stats.nsecs; 4996 info.run_cnt = stats.cnt; 4997 info.recursion_misses = stats.misses; 4998 4999 info.verified_insns = prog->aux->verified_insns; 5000 if (prog->aux->btf) 5001 info.btf_id = btf_obj_id(prog->aux->btf); 5002 5003 if (!bpf_capable()) { 5004 info.jited_prog_len = 0; 5005 info.xlated_prog_len = 0; 5006 info.nr_jited_ksyms = 0; 5007 info.nr_jited_func_lens = 0; 5008 info.nr_func_info = 0; 5009 info.nr_line_info = 0; 5010 info.nr_jited_line_info = 0; 5011 goto done; 5012 } 5013 5014 ulen = info.xlated_prog_len; 5015 info.xlated_prog_len = bpf_prog_insn_size(prog); 5016 if (info.xlated_prog_len && ulen) { 5017 struct bpf_insn *insns_sanitized; 5018 bool fault; 5019 5020 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) { 5021 info.xlated_prog_insns = 0; 5022 goto done; 5023 } 5024 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred); 5025 if (!insns_sanitized) 5026 return -ENOMEM; 5027 uinsns = u64_to_user_ptr(info.xlated_prog_insns); 5028 ulen = min_t(u32, info.xlated_prog_len, ulen); 5029 fault = copy_to_user(uinsns, insns_sanitized, ulen); 5030 kfree(insns_sanitized); 5031 if (fault) 5032 return -EFAULT; 5033 } 5034 5035 if (bpf_prog_is_offloaded(prog->aux)) { 5036 err = bpf_prog_offload_info_fill(&info, prog); 5037 if (err) 5038 return err; 5039 goto done; 5040 } 5041 5042 /* NOTE: the following code is supposed to be skipped for offload. 5043 * bpf_prog_offload_info_fill() is the place to fill similar fields 5044 * for offload. 5045 */ 5046 ulen = info.jited_prog_len; 5047 if (prog->aux->func_cnt) { 5048 u32 i; 5049 5050 info.jited_prog_len = 0; 5051 for (i = 0; i < prog->aux->func_cnt; i++) 5052 info.jited_prog_len += prog->aux->func[i]->jited_len; 5053 } else { 5054 info.jited_prog_len = prog->jited_len; 5055 } 5056 5057 if (info.jited_prog_len && ulen) { 5058 if (bpf_dump_raw_ok(file->f_cred)) { 5059 uinsns = u64_to_user_ptr(info.jited_prog_insns); 5060 ulen = min_t(u32, info.jited_prog_len, ulen); 5061 5062 /* for multi-function programs, copy the JITed 5063 * instructions for all the functions 5064 */ 5065 if (prog->aux->func_cnt) { 5066 u32 len, free, i; 5067 u8 *img; 5068 5069 free = ulen; 5070 for (i = 0; i < prog->aux->func_cnt; i++) { 5071 len = prog->aux->func[i]->jited_len; 5072 len = min_t(u32, len, free); 5073 img = (u8 *) prog->aux->func[i]->bpf_func; 5074 if (copy_to_user(uinsns, img, len)) 5075 return -EFAULT; 5076 uinsns += len; 5077 free -= len; 5078 if (!free) 5079 break; 5080 } 5081 } else { 5082 if (copy_to_user(uinsns, prog->bpf_func, ulen)) 5083 return -EFAULT; 5084 } 5085 } else { 5086 info.jited_prog_insns = 0; 5087 } 5088 } 5089 5090 ulen = info.nr_jited_ksyms; 5091 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1; 5092 if (ulen) { 5093 if (bpf_dump_raw_ok(file->f_cred)) { 5094 unsigned long ksym_addr; 5095 u64 __user *user_ksyms; 5096 u32 i; 5097 5098 /* copy the address of the kernel symbol 5099 * corresponding to each function 5100 */ 5101 ulen = min_t(u32, info.nr_jited_ksyms, ulen); 5102 user_ksyms = u64_to_user_ptr(info.jited_ksyms); 5103 if (prog->aux->func_cnt) { 5104 for (i = 0; i < ulen; i++) { 5105 ksym_addr = (unsigned long) 5106 prog->aux->func[i]->bpf_func; 5107 if (put_user((u64) ksym_addr, 5108 &user_ksyms[i])) 5109 return -EFAULT; 5110 } 5111 } else { 5112 ksym_addr = (unsigned long) prog->bpf_func; 5113 if (put_user((u64) ksym_addr, &user_ksyms[0])) 5114 return -EFAULT; 5115 } 5116 } else { 5117 info.jited_ksyms = 0; 5118 } 5119 } 5120 5121 ulen = info.nr_jited_func_lens; 5122 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1; 5123 if (ulen) { 5124 if (bpf_dump_raw_ok(file->f_cred)) { 5125 u32 __user *user_lens; 5126 u32 func_len, i; 5127 5128 /* copy the JITed image lengths for each function */ 5129 ulen = min_t(u32, info.nr_jited_func_lens, ulen); 5130 user_lens = u64_to_user_ptr(info.jited_func_lens); 5131 if (prog->aux->func_cnt) { 5132 for (i = 0; i < ulen; i++) { 5133 func_len = 5134 prog->aux->func[i]->jited_len; 5135 if (put_user(func_len, &user_lens[i])) 5136 return -EFAULT; 5137 } 5138 } else { 5139 func_len = prog->jited_len; 5140 if (put_user(func_len, &user_lens[0])) 5141 return -EFAULT; 5142 } 5143 } else { 5144 info.jited_func_lens = 0; 5145 } 5146 } 5147 5148 info.attach_btf_id = prog->aux->attach_btf_id; 5149 if (attach_btf) 5150 info.attach_btf_obj_id = btf_obj_id(attach_btf); 5151 5152 ulen = info.nr_func_info; 5153 info.nr_func_info = prog->aux->func_info_cnt; 5154 if (info.nr_func_info && ulen) { 5155 char __user *user_finfo; 5156 5157 user_finfo = u64_to_user_ptr(info.func_info); 5158 ulen = min_t(u32, info.nr_func_info, ulen); 5159 if (copy_to_user(user_finfo, prog->aux->func_info, 5160 info.func_info_rec_size * ulen)) 5161 return -EFAULT; 5162 } 5163 5164 ulen = info.nr_line_info; 5165 info.nr_line_info = prog->aux->nr_linfo; 5166 if (info.nr_line_info && ulen) { 5167 __u8 __user *user_linfo; 5168 5169 user_linfo = u64_to_user_ptr(info.line_info); 5170 ulen = min_t(u32, info.nr_line_info, ulen); 5171 if (copy_to_user(user_linfo, prog->aux->linfo, 5172 info.line_info_rec_size * ulen)) 5173 return -EFAULT; 5174 } 5175 5176 ulen = info.nr_jited_line_info; 5177 if (prog->aux->jited_linfo) 5178 info.nr_jited_line_info = prog->aux->nr_linfo; 5179 else 5180 info.nr_jited_line_info = 0; 5181 if (info.nr_jited_line_info && ulen) { 5182 if (bpf_dump_raw_ok(file->f_cred)) { 5183 unsigned long line_addr; 5184 __u64 __user *user_linfo; 5185 u32 i; 5186 5187 user_linfo = u64_to_user_ptr(info.jited_line_info); 5188 ulen = min_t(u32, info.nr_jited_line_info, ulen); 5189 for (i = 0; i < ulen; i++) { 5190 line_addr = (unsigned long)prog->aux->jited_linfo[i]; 5191 if (put_user((__u64)line_addr, &user_linfo[i])) 5192 return -EFAULT; 5193 } 5194 } else { 5195 info.jited_line_info = 0; 5196 } 5197 } 5198 5199 ulen = info.nr_prog_tags; 5200 info.nr_prog_tags = prog->aux->func_cnt ? : 1; 5201 if (ulen) { 5202 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE]; 5203 u32 i; 5204 5205 user_prog_tags = u64_to_user_ptr(info.prog_tags); 5206 ulen = min_t(u32, info.nr_prog_tags, ulen); 5207 if (prog->aux->func_cnt) { 5208 for (i = 0; i < ulen; i++) { 5209 if (copy_to_user(user_prog_tags[i], 5210 prog->aux->func[i]->tag, 5211 BPF_TAG_SIZE)) 5212 return -EFAULT; 5213 } 5214 } else { 5215 if (copy_to_user(user_prog_tags[0], 5216 prog->tag, BPF_TAG_SIZE)) 5217 return -EFAULT; 5218 } 5219 } 5220 5221 done: 5222 if (copy_to_user(uinfo, &info, info_len) || 5223 put_user(info_len, &uattr->info.info_len)) 5224 return -EFAULT; 5225 5226 return 0; 5227 } 5228 5229 static int bpf_map_get_info_by_fd(struct file *file, 5230 struct bpf_map *map, 5231 const union bpf_attr *attr, 5232 union bpf_attr __user *uattr) 5233 { 5234 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5235 struct bpf_map_info info; 5236 u32 info_len = attr->info.info_len; 5237 int err; 5238 5239 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5240 if (err) 5241 return err; 5242 info_len = min_t(u32, sizeof(info), info_len); 5243 5244 memset(&info, 0, sizeof(info)); 5245 if (copy_from_user(&info, uinfo, info_len)) 5246 return -EFAULT; 5247 5248 info.type = map->map_type; 5249 info.id = map->id; 5250 info.key_size = map->key_size; 5251 info.value_size = map->value_size; 5252 info.max_entries = map->max_entries; 5253 info.map_flags = map->map_flags; 5254 info.map_extra = map->map_extra; 5255 memcpy(info.name, map->name, sizeof(map->name)); 5256 5257 if (map->btf) { 5258 info.btf_id = btf_obj_id(map->btf); 5259 info.btf_key_type_id = map->btf_key_type_id; 5260 info.btf_value_type_id = map->btf_value_type_id; 5261 } 5262 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; 5263 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) 5264 bpf_map_struct_ops_info_fill(&info, map); 5265 5266 if (bpf_map_is_offloaded(map)) { 5267 err = bpf_map_offload_info_fill(&info, map); 5268 if (err) 5269 return err; 5270 } 5271 5272 if (info.hash) { 5273 char __user *uhash = u64_to_user_ptr(info.hash); 5274 5275 if (!map->ops->map_get_hash) 5276 return -EINVAL; 5277 5278 if (info.hash_size != SHA256_DIGEST_SIZE) 5279 return -EINVAL; 5280 5281 err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha); 5282 if (err != 0) 5283 return err; 5284 5285 if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0) 5286 return -EFAULT; 5287 } else if (info.hash_size) { 5288 return -EINVAL; 5289 } 5290 5291 if (copy_to_user(uinfo, &info, info_len) || 5292 put_user(info_len, &uattr->info.info_len)) 5293 return -EFAULT; 5294 5295 return 0; 5296 } 5297 5298 static int bpf_btf_get_info_by_fd(struct file *file, 5299 struct btf *btf, 5300 const union bpf_attr *attr, 5301 union bpf_attr __user *uattr) 5302 { 5303 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5304 u32 info_len = attr->info.info_len; 5305 int err; 5306 5307 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5308 if (err) 5309 return err; 5310 5311 return btf_get_info_by_fd(btf, attr, uattr); 5312 } 5313 5314 static int bpf_link_get_info_by_fd(struct file *file, 5315 struct bpf_link *link, 5316 const union bpf_attr *attr, 5317 union bpf_attr __user *uattr) 5318 { 5319 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5320 struct bpf_link_info info; 5321 u32 info_len = attr->info.info_len; 5322 int err; 5323 5324 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len); 5325 if (err) 5326 return err; 5327 info_len = min_t(u32, sizeof(info), info_len); 5328 5329 memset(&info, 0, sizeof(info)); 5330 if (copy_from_user(&info, uinfo, info_len)) 5331 return -EFAULT; 5332 5333 info.type = link->type; 5334 info.id = link->id; 5335 if (link->prog) 5336 info.prog_id = link->prog->aux->id; 5337 5338 if (link->ops->fill_link_info) { 5339 err = link->ops->fill_link_info(link, &info); 5340 if (err) 5341 return err; 5342 } 5343 5344 if (copy_to_user(uinfo, &info, info_len) || 5345 put_user(info_len, &uattr->info.info_len)) 5346 return -EFAULT; 5347 5348 return 0; 5349 } 5350 5351 5352 static int token_get_info_by_fd(struct file *file, 5353 struct bpf_token *token, 5354 const union bpf_attr *attr, 5355 union bpf_attr __user *uattr) 5356 { 5357 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info); 5358 u32 info_len = attr->info.info_len; 5359 int err; 5360 5361 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len); 5362 if (err) 5363 return err; 5364 return bpf_token_get_info_by_fd(token, attr, uattr); 5365 } 5366 5367 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info 5368 5369 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, 5370 union bpf_attr __user *uattr) 5371 { 5372 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) 5373 return -EINVAL; 5374 5375 CLASS(fd, f)(attr->info.bpf_fd); 5376 if (fd_empty(f)) 5377 return -EBADFD; 5378 5379 if (fd_file(f)->f_op == &bpf_prog_fops) 5380 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5381 uattr); 5382 else if (fd_file(f)->f_op == &bpf_map_fops) 5383 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, 5384 uattr); 5385 else if (fd_file(f)->f_op == &btf_fops) 5386 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr); 5387 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll) 5388 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5389 attr, uattr); 5390 else if (fd_file(f)->f_op == &bpf_token_fops) 5391 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data, 5392 attr, uattr); 5393 return -EINVAL; 5394 } 5395 5396 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd 5397 5398 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) 5399 { 5400 struct bpf_token *token = NULL; 5401 5402 if (CHECK_ATTR(BPF_BTF_LOAD)) 5403 return -EINVAL; 5404 5405 if (attr->btf_flags & ~BPF_F_TOKEN_FD) 5406 return -EINVAL; 5407 5408 if (attr->btf_flags & BPF_F_TOKEN_FD) { 5409 token = bpf_token_get_from_fd(attr->btf_token_fd); 5410 if (IS_ERR(token)) 5411 return PTR_ERR(token); 5412 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) { 5413 bpf_token_put(token); 5414 token = NULL; 5415 } 5416 } 5417 5418 if (!bpf_token_capable(token, CAP_BPF)) { 5419 bpf_token_put(token); 5420 return -EPERM; 5421 } 5422 5423 bpf_token_put(token); 5424 5425 return btf_new_fd(attr, uattr, uattr_size); 5426 } 5427 5428 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd 5429 5430 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr) 5431 { 5432 struct bpf_token *token = NULL; 5433 5434 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID)) 5435 return -EINVAL; 5436 5437 if (attr->open_flags & ~BPF_F_TOKEN_FD) 5438 return -EINVAL; 5439 5440 if (attr->open_flags & BPF_F_TOKEN_FD) { 5441 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd); 5442 if (IS_ERR(token)) 5443 return PTR_ERR(token); 5444 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) { 5445 bpf_token_put(token); 5446 token = NULL; 5447 } 5448 } 5449 5450 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) { 5451 bpf_token_put(token); 5452 return -EPERM; 5453 } 5454 5455 bpf_token_put(token); 5456 5457 return btf_get_fd_by_id(attr->btf_id); 5458 } 5459 5460 static int bpf_task_fd_query_copy(const union bpf_attr *attr, 5461 union bpf_attr __user *uattr, 5462 u32 prog_id, u32 fd_type, 5463 const char *buf, u64 probe_offset, 5464 u64 probe_addr) 5465 { 5466 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf); 5467 u32 len = buf ? strlen(buf) : 0, input_len; 5468 int err = 0; 5469 5470 if (put_user(len, &uattr->task_fd_query.buf_len)) 5471 return -EFAULT; 5472 input_len = attr->task_fd_query.buf_len; 5473 if (input_len && ubuf) { 5474 if (!len) { 5475 /* nothing to copy, just make ubuf NULL terminated */ 5476 char zero = '\0'; 5477 5478 if (put_user(zero, ubuf)) 5479 return -EFAULT; 5480 } else { 5481 err = bpf_copy_to_user(ubuf, buf, input_len, len); 5482 if (err == -EFAULT) 5483 return err; 5484 } 5485 } 5486 5487 if (put_user(prog_id, &uattr->task_fd_query.prog_id) || 5488 put_user(fd_type, &uattr->task_fd_query.fd_type) || 5489 put_user(probe_offset, &uattr->task_fd_query.probe_offset) || 5490 put_user(probe_addr, &uattr->task_fd_query.probe_addr)) 5491 return -EFAULT; 5492 5493 return err; 5494 } 5495 5496 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr 5497 5498 static int bpf_task_fd_query(const union bpf_attr *attr, 5499 union bpf_attr __user *uattr) 5500 { 5501 pid_t pid = attr->task_fd_query.pid; 5502 u32 fd = attr->task_fd_query.fd; 5503 const struct perf_event *event; 5504 struct task_struct *task; 5505 struct file *file; 5506 int err; 5507 5508 if (CHECK_ATTR(BPF_TASK_FD_QUERY)) 5509 return -EINVAL; 5510 5511 if (!capable(CAP_SYS_ADMIN)) 5512 return -EPERM; 5513 5514 if (attr->task_fd_query.flags != 0) 5515 return -EINVAL; 5516 5517 rcu_read_lock(); 5518 task = get_pid_task(find_vpid(pid), PIDTYPE_PID); 5519 rcu_read_unlock(); 5520 if (!task) 5521 return -ENOENT; 5522 5523 err = 0; 5524 file = fget_task(task, fd); 5525 put_task_struct(task); 5526 if (!file) 5527 return -EBADF; 5528 5529 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) { 5530 struct bpf_link *link = file->private_data; 5531 5532 if (link->ops == &bpf_raw_tp_link_lops) { 5533 struct bpf_raw_tp_link *raw_tp = 5534 container_of(link, struct bpf_raw_tp_link, link); 5535 struct bpf_raw_event_map *btp = raw_tp->btp; 5536 5537 err = bpf_task_fd_query_copy(attr, uattr, 5538 raw_tp->link.prog->aux->id, 5539 BPF_FD_TYPE_RAW_TRACEPOINT, 5540 btp->tp->name, 0, 0); 5541 goto put_file; 5542 } 5543 goto out_not_supp; 5544 } 5545 5546 event = perf_get_event(file); 5547 if (!IS_ERR(event)) { 5548 u64 probe_offset, probe_addr; 5549 u32 prog_id, fd_type; 5550 const char *buf; 5551 5552 err = bpf_get_perf_event_info(event, &prog_id, &fd_type, 5553 &buf, &probe_offset, 5554 &probe_addr, NULL); 5555 if (!err) 5556 err = bpf_task_fd_query_copy(attr, uattr, prog_id, 5557 fd_type, buf, 5558 probe_offset, 5559 probe_addr); 5560 goto put_file; 5561 } 5562 5563 out_not_supp: 5564 err = -ENOTSUPP; 5565 put_file: 5566 fput(file); 5567 return err; 5568 } 5569 5570 #define BPF_MAP_BATCH_LAST_FIELD batch.flags 5571 5572 #define BPF_DO_BATCH(fn, ...) \ 5573 do { \ 5574 if (!fn) { \ 5575 err = -ENOTSUPP; \ 5576 goto err_put; \ 5577 } \ 5578 err = fn(__VA_ARGS__); \ 5579 } while (0) 5580 5581 static int bpf_map_do_batch(const union bpf_attr *attr, 5582 union bpf_attr __user *uattr, 5583 int cmd) 5584 { 5585 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH || 5586 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH; 5587 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH; 5588 struct bpf_map *map; 5589 int err; 5590 5591 if (CHECK_ATTR(BPF_MAP_BATCH)) 5592 return -EINVAL; 5593 5594 CLASS(fd, f)(attr->batch.map_fd); 5595 5596 map = __bpf_map_get(f); 5597 if (IS_ERR(map)) 5598 return PTR_ERR(map); 5599 if (has_write) 5600 bpf_map_write_active_inc(map); 5601 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) { 5602 err = -EPERM; 5603 goto err_put; 5604 } 5605 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { 5606 err = -EPERM; 5607 goto err_put; 5608 } 5609 5610 if (cmd == BPF_MAP_LOOKUP_BATCH) 5611 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr); 5612 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) 5613 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr); 5614 else if (cmd == BPF_MAP_UPDATE_BATCH) 5615 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr); 5616 else 5617 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr); 5618 err_put: 5619 if (has_write) { 5620 maybe_wait_bpf_programs(map); 5621 bpf_map_write_active_dec(map); 5622 } 5623 return err; 5624 } 5625 5626 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid 5627 static int link_create(union bpf_attr *attr, bpfptr_t uattr) 5628 { 5629 struct bpf_prog *prog; 5630 int ret; 5631 5632 if (CHECK_ATTR(BPF_LINK_CREATE)) 5633 return -EINVAL; 5634 5635 if (attr->link_create.attach_type == BPF_STRUCT_OPS) 5636 return bpf_struct_ops_link_create(attr); 5637 5638 prog = bpf_prog_get(attr->link_create.prog_fd); 5639 if (IS_ERR(prog)) 5640 return PTR_ERR(prog); 5641 5642 ret = bpf_prog_attach_check_attach_type(prog, 5643 attr->link_create.attach_type); 5644 if (ret) 5645 goto out; 5646 5647 switch (prog->type) { 5648 case BPF_PROG_TYPE_CGROUP_SKB: 5649 case BPF_PROG_TYPE_CGROUP_SOCK: 5650 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 5651 case BPF_PROG_TYPE_SOCK_OPS: 5652 case BPF_PROG_TYPE_CGROUP_DEVICE: 5653 case BPF_PROG_TYPE_CGROUP_SYSCTL: 5654 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 5655 ret = cgroup_bpf_link_attach(attr, prog); 5656 break; 5657 case BPF_PROG_TYPE_EXT: 5658 ret = bpf_tracing_prog_attach(prog, 5659 attr->link_create.target_fd, 5660 attr->link_create.target_btf_id, 5661 attr->link_create.tracing.cookie, 5662 attr->link_create.attach_type); 5663 break; 5664 case BPF_PROG_TYPE_LSM: 5665 case BPF_PROG_TYPE_TRACING: 5666 if (attr->link_create.attach_type != prog->expected_attach_type) { 5667 ret = -EINVAL; 5668 goto out; 5669 } 5670 if (prog->expected_attach_type == BPF_TRACE_RAW_TP) 5671 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie, 5672 attr->link_create.attach_type); 5673 else if (prog->expected_attach_type == BPF_TRACE_ITER) 5674 ret = bpf_iter_link_attach(attr, uattr, prog); 5675 else if (prog->expected_attach_type == BPF_LSM_CGROUP) 5676 ret = cgroup_bpf_link_attach(attr, prog); 5677 else 5678 ret = bpf_tracing_prog_attach(prog, 5679 attr->link_create.target_fd, 5680 attr->link_create.target_btf_id, 5681 attr->link_create.tracing.cookie, 5682 attr->link_create.attach_type); 5683 break; 5684 case BPF_PROG_TYPE_FLOW_DISSECTOR: 5685 case BPF_PROG_TYPE_SK_LOOKUP: 5686 ret = netns_bpf_link_create(attr, prog); 5687 break; 5688 case BPF_PROG_TYPE_SK_MSG: 5689 case BPF_PROG_TYPE_SK_SKB: 5690 ret = sock_map_link_create(attr, prog); 5691 break; 5692 #ifdef CONFIG_NET 5693 case BPF_PROG_TYPE_XDP: 5694 ret = bpf_xdp_link_attach(attr, prog); 5695 break; 5696 case BPF_PROG_TYPE_SCHED_CLS: 5697 if (attr->link_create.attach_type == BPF_TCX_INGRESS || 5698 attr->link_create.attach_type == BPF_TCX_EGRESS) 5699 ret = tcx_link_attach(attr, prog); 5700 else 5701 ret = netkit_link_attach(attr, prog); 5702 break; 5703 case BPF_PROG_TYPE_NETFILTER: 5704 ret = bpf_nf_link_attach(attr, prog); 5705 break; 5706 #endif 5707 case BPF_PROG_TYPE_PERF_EVENT: 5708 case BPF_PROG_TYPE_TRACEPOINT: 5709 ret = bpf_perf_link_attach(attr, prog); 5710 break; 5711 case BPF_PROG_TYPE_KPROBE: 5712 if (attr->link_create.attach_type == BPF_PERF_EVENT) 5713 ret = bpf_perf_link_attach(attr, prog); 5714 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI || 5715 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION) 5716 ret = bpf_kprobe_multi_link_attach(attr, prog); 5717 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI || 5718 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION) 5719 ret = bpf_uprobe_multi_link_attach(attr, prog); 5720 break; 5721 default: 5722 ret = -EINVAL; 5723 } 5724 5725 out: 5726 if (ret < 0) 5727 bpf_prog_put(prog); 5728 return ret; 5729 } 5730 5731 static int link_update_map(struct bpf_link *link, union bpf_attr *attr) 5732 { 5733 struct bpf_map *new_map, *old_map = NULL; 5734 int ret; 5735 5736 new_map = bpf_map_get(attr->link_update.new_map_fd); 5737 if (IS_ERR(new_map)) 5738 return PTR_ERR(new_map); 5739 5740 if (attr->link_update.flags & BPF_F_REPLACE) { 5741 old_map = bpf_map_get(attr->link_update.old_map_fd); 5742 if (IS_ERR(old_map)) { 5743 ret = PTR_ERR(old_map); 5744 goto out_put; 5745 } 5746 } else if (attr->link_update.old_map_fd) { 5747 ret = -EINVAL; 5748 goto out_put; 5749 } 5750 5751 ret = link->ops->update_map(link, new_map, old_map); 5752 5753 if (old_map) 5754 bpf_map_put(old_map); 5755 out_put: 5756 bpf_map_put(new_map); 5757 return ret; 5758 } 5759 5760 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd 5761 5762 static int link_update(union bpf_attr *attr) 5763 { 5764 struct bpf_prog *old_prog = NULL, *new_prog; 5765 struct bpf_link *link; 5766 u32 flags; 5767 int ret; 5768 5769 if (CHECK_ATTR(BPF_LINK_UPDATE)) 5770 return -EINVAL; 5771 5772 flags = attr->link_update.flags; 5773 if (flags & ~BPF_F_REPLACE) 5774 return -EINVAL; 5775 5776 link = bpf_link_get_from_fd(attr->link_update.link_fd); 5777 if (IS_ERR(link)) 5778 return PTR_ERR(link); 5779 5780 if (link->ops->update_map) { 5781 ret = link_update_map(link, attr); 5782 goto out_put_link; 5783 } 5784 5785 new_prog = bpf_prog_get(attr->link_update.new_prog_fd); 5786 if (IS_ERR(new_prog)) { 5787 ret = PTR_ERR(new_prog); 5788 goto out_put_link; 5789 } 5790 5791 if (flags & BPF_F_REPLACE) { 5792 old_prog = bpf_prog_get(attr->link_update.old_prog_fd); 5793 if (IS_ERR(old_prog)) { 5794 ret = PTR_ERR(old_prog); 5795 old_prog = NULL; 5796 goto out_put_progs; 5797 } 5798 } else if (attr->link_update.old_prog_fd) { 5799 ret = -EINVAL; 5800 goto out_put_progs; 5801 } 5802 5803 if (link->ops->update_prog) 5804 ret = link->ops->update_prog(link, new_prog, old_prog); 5805 else 5806 ret = -EINVAL; 5807 5808 out_put_progs: 5809 if (old_prog) 5810 bpf_prog_put(old_prog); 5811 if (ret) 5812 bpf_prog_put(new_prog); 5813 out_put_link: 5814 bpf_link_put_direct(link); 5815 return ret; 5816 } 5817 5818 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd 5819 5820 static int link_detach(union bpf_attr *attr) 5821 { 5822 struct bpf_link *link; 5823 int ret; 5824 5825 if (CHECK_ATTR(BPF_LINK_DETACH)) 5826 return -EINVAL; 5827 5828 link = bpf_link_get_from_fd(attr->link_detach.link_fd); 5829 if (IS_ERR(link)) 5830 return PTR_ERR(link); 5831 5832 if (link->ops->detach) 5833 ret = link->ops->detach(link); 5834 else 5835 ret = -EOPNOTSUPP; 5836 5837 bpf_link_put_direct(link); 5838 return ret; 5839 } 5840 5841 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link) 5842 { 5843 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT); 5844 } 5845 EXPORT_SYMBOL(bpf_link_inc_not_zero); 5846 5847 struct bpf_link *bpf_link_by_id(u32 id) 5848 { 5849 struct bpf_link *link; 5850 5851 if (!id) 5852 return ERR_PTR(-ENOENT); 5853 5854 spin_lock_bh(&link_idr_lock); 5855 /* before link is "settled", ID is 0, pretend it doesn't exist yet */ 5856 link = idr_find(&link_idr, id); 5857 if (link) { 5858 if (link->id) 5859 link = bpf_link_inc_not_zero(link); 5860 else 5861 link = ERR_PTR(-EAGAIN); 5862 } else { 5863 link = ERR_PTR(-ENOENT); 5864 } 5865 spin_unlock_bh(&link_idr_lock); 5866 return link; 5867 } 5868 5869 struct bpf_link *bpf_link_get_curr_or_next(u32 *id) 5870 { 5871 struct bpf_link *link; 5872 5873 spin_lock_bh(&link_idr_lock); 5874 again: 5875 link = idr_get_next(&link_idr, id); 5876 if (link) { 5877 link = bpf_link_inc_not_zero(link); 5878 if (IS_ERR(link)) { 5879 (*id)++; 5880 goto again; 5881 } 5882 } 5883 spin_unlock_bh(&link_idr_lock); 5884 5885 return link; 5886 } 5887 5888 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id 5889 5890 static int bpf_link_get_fd_by_id(const union bpf_attr *attr) 5891 { 5892 struct bpf_link *link; 5893 u32 id = attr->link_id; 5894 int fd; 5895 5896 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID)) 5897 return -EINVAL; 5898 5899 if (!capable(CAP_SYS_ADMIN)) 5900 return -EPERM; 5901 5902 link = bpf_link_by_id(id); 5903 if (IS_ERR(link)) 5904 return PTR_ERR(link); 5905 5906 fd = bpf_link_new_fd(link); 5907 if (fd < 0) 5908 bpf_link_put_direct(link); 5909 5910 return fd; 5911 } 5912 5913 DEFINE_MUTEX(bpf_stats_enabled_mutex); 5914 5915 static int bpf_stats_release(struct inode *inode, struct file *file) 5916 { 5917 mutex_lock(&bpf_stats_enabled_mutex); 5918 static_key_slow_dec(&bpf_stats_enabled_key.key); 5919 mutex_unlock(&bpf_stats_enabled_mutex); 5920 return 0; 5921 } 5922 5923 static const struct file_operations bpf_stats_fops = { 5924 .release = bpf_stats_release, 5925 }; 5926 5927 static int bpf_enable_runtime_stats(void) 5928 { 5929 int fd; 5930 5931 mutex_lock(&bpf_stats_enabled_mutex); 5932 5933 /* Set a very high limit to avoid overflow */ 5934 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) { 5935 mutex_unlock(&bpf_stats_enabled_mutex); 5936 return -EBUSY; 5937 } 5938 5939 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC); 5940 if (fd >= 0) 5941 static_key_slow_inc(&bpf_stats_enabled_key.key); 5942 5943 mutex_unlock(&bpf_stats_enabled_mutex); 5944 return fd; 5945 } 5946 5947 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type 5948 5949 static int bpf_enable_stats(union bpf_attr *attr) 5950 { 5951 5952 if (CHECK_ATTR(BPF_ENABLE_STATS)) 5953 return -EINVAL; 5954 5955 if (!capable(CAP_SYS_ADMIN)) 5956 return -EPERM; 5957 5958 switch (attr->enable_stats.type) { 5959 case BPF_STATS_RUN_TIME: 5960 return bpf_enable_runtime_stats(); 5961 default: 5962 break; 5963 } 5964 return -EINVAL; 5965 } 5966 5967 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags 5968 5969 static int bpf_iter_create(union bpf_attr *attr) 5970 { 5971 struct bpf_link *link; 5972 int err; 5973 5974 if (CHECK_ATTR(BPF_ITER_CREATE)) 5975 return -EINVAL; 5976 5977 if (attr->iter_create.flags) 5978 return -EINVAL; 5979 5980 link = bpf_link_get_from_fd(attr->iter_create.link_fd); 5981 if (IS_ERR(link)) 5982 return PTR_ERR(link); 5983 5984 err = bpf_iter_new_fd(link); 5985 bpf_link_put_direct(link); 5986 5987 return err; 5988 } 5989 5990 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags 5991 5992 static int bpf_prog_bind_map(union bpf_attr *attr) 5993 { 5994 struct bpf_prog *prog; 5995 struct bpf_map *map; 5996 struct bpf_map **used_maps_old, **used_maps_new; 5997 int i, ret = 0; 5998 5999 if (CHECK_ATTR(BPF_PROG_BIND_MAP)) 6000 return -EINVAL; 6001 6002 if (attr->prog_bind_map.flags) 6003 return -EINVAL; 6004 6005 prog = bpf_prog_get(attr->prog_bind_map.prog_fd); 6006 if (IS_ERR(prog)) 6007 return PTR_ERR(prog); 6008 6009 map = bpf_map_get(attr->prog_bind_map.map_fd); 6010 if (IS_ERR(map)) { 6011 ret = PTR_ERR(map); 6012 goto out_prog_put; 6013 } 6014 6015 mutex_lock(&prog->aux->used_maps_mutex); 6016 6017 used_maps_old = prog->aux->used_maps; 6018 6019 for (i = 0; i < prog->aux->used_map_cnt; i++) 6020 if (used_maps_old[i] == map) { 6021 bpf_map_put(map); 6022 goto out_unlock; 6023 } 6024 6025 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1, 6026 sizeof(used_maps_new[0]), 6027 GFP_KERNEL); 6028 if (!used_maps_new) { 6029 ret = -ENOMEM; 6030 goto out_unlock; 6031 } 6032 6033 /* The bpf program will not access the bpf map, but for the sake of 6034 * simplicity, increase sleepable_refcnt for sleepable program as well. 6035 */ 6036 if (prog->sleepable) 6037 atomic64_inc(&map->sleepable_refcnt); 6038 memcpy(used_maps_new, used_maps_old, 6039 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt); 6040 used_maps_new[prog->aux->used_map_cnt] = map; 6041 6042 prog->aux->used_map_cnt++; 6043 prog->aux->used_maps = used_maps_new; 6044 6045 kfree(used_maps_old); 6046 6047 out_unlock: 6048 mutex_unlock(&prog->aux->used_maps_mutex); 6049 6050 if (ret) 6051 bpf_map_put(map); 6052 out_prog_put: 6053 bpf_prog_put(prog); 6054 return ret; 6055 } 6056 6057 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd 6058 6059 static int token_create(union bpf_attr *attr) 6060 { 6061 if (CHECK_ATTR(BPF_TOKEN_CREATE)) 6062 return -EINVAL; 6063 6064 /* no flags are supported yet */ 6065 if (attr->token_create.flags) 6066 return -EINVAL; 6067 6068 return bpf_token_create(attr); 6069 } 6070 6071 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd 6072 6073 static int prog_stream_read(union bpf_attr *attr) 6074 { 6075 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf); 6076 u32 len = attr->prog_stream_read.stream_buf_len; 6077 struct bpf_prog *prog; 6078 int ret; 6079 6080 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD)) 6081 return -EINVAL; 6082 6083 prog = bpf_prog_get(attr->prog_stream_read.prog_fd); 6084 if (IS_ERR(prog)) 6085 return PTR_ERR(prog); 6086 6087 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len); 6088 bpf_prog_put(prog); 6089 6090 return ret; 6091 } 6092 6093 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size) 6094 { 6095 union bpf_attr attr; 6096 int err; 6097 6098 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size); 6099 if (err) 6100 return err; 6101 size = min_t(u32, size, sizeof(attr)); 6102 6103 /* copy attributes from user space, may be less than sizeof(bpf_attr) */ 6104 memset(&attr, 0, sizeof(attr)); 6105 if (copy_from_bpfptr(&attr, uattr, size) != 0) 6106 return -EFAULT; 6107 6108 err = security_bpf(cmd, &attr, size, uattr.is_kernel); 6109 if (err < 0) 6110 return err; 6111 6112 switch (cmd) { 6113 case BPF_MAP_CREATE: 6114 err = map_create(&attr, uattr); 6115 break; 6116 case BPF_MAP_LOOKUP_ELEM: 6117 err = map_lookup_elem(&attr); 6118 break; 6119 case BPF_MAP_UPDATE_ELEM: 6120 err = map_update_elem(&attr, uattr); 6121 break; 6122 case BPF_MAP_DELETE_ELEM: 6123 err = map_delete_elem(&attr, uattr); 6124 break; 6125 case BPF_MAP_GET_NEXT_KEY: 6126 err = map_get_next_key(&attr); 6127 break; 6128 case BPF_MAP_FREEZE: 6129 err = map_freeze(&attr); 6130 break; 6131 case BPF_PROG_LOAD: 6132 err = bpf_prog_load(&attr, uattr, size); 6133 break; 6134 case BPF_OBJ_PIN: 6135 err = bpf_obj_pin(&attr); 6136 break; 6137 case BPF_OBJ_GET: 6138 err = bpf_obj_get(&attr); 6139 break; 6140 case BPF_PROG_ATTACH: 6141 err = bpf_prog_attach(&attr); 6142 break; 6143 case BPF_PROG_DETACH: 6144 err = bpf_prog_detach(&attr); 6145 break; 6146 case BPF_PROG_QUERY: 6147 err = bpf_prog_query(&attr, uattr.user); 6148 break; 6149 case BPF_PROG_TEST_RUN: 6150 err = bpf_prog_test_run(&attr, uattr.user); 6151 break; 6152 case BPF_PROG_GET_NEXT_ID: 6153 err = bpf_obj_get_next_id(&attr, uattr.user, 6154 &prog_idr, &prog_idr_lock); 6155 break; 6156 case BPF_MAP_GET_NEXT_ID: 6157 err = bpf_obj_get_next_id(&attr, uattr.user, 6158 &map_idr, &map_idr_lock); 6159 break; 6160 case BPF_BTF_GET_NEXT_ID: 6161 err = bpf_obj_get_next_id(&attr, uattr.user, 6162 &btf_idr, &btf_idr_lock); 6163 break; 6164 case BPF_PROG_GET_FD_BY_ID: 6165 err = bpf_prog_get_fd_by_id(&attr); 6166 break; 6167 case BPF_MAP_GET_FD_BY_ID: 6168 err = bpf_map_get_fd_by_id(&attr); 6169 break; 6170 case BPF_OBJ_GET_INFO_BY_FD: 6171 err = bpf_obj_get_info_by_fd(&attr, uattr.user); 6172 break; 6173 case BPF_RAW_TRACEPOINT_OPEN: 6174 err = bpf_raw_tracepoint_open(&attr); 6175 break; 6176 case BPF_BTF_LOAD: 6177 err = bpf_btf_load(&attr, uattr, size); 6178 break; 6179 case BPF_BTF_GET_FD_BY_ID: 6180 err = bpf_btf_get_fd_by_id(&attr); 6181 break; 6182 case BPF_TASK_FD_QUERY: 6183 err = bpf_task_fd_query(&attr, uattr.user); 6184 break; 6185 case BPF_MAP_LOOKUP_AND_DELETE_ELEM: 6186 err = map_lookup_and_delete_elem(&attr); 6187 break; 6188 case BPF_MAP_LOOKUP_BATCH: 6189 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH); 6190 break; 6191 case BPF_MAP_LOOKUP_AND_DELETE_BATCH: 6192 err = bpf_map_do_batch(&attr, uattr.user, 6193 BPF_MAP_LOOKUP_AND_DELETE_BATCH); 6194 break; 6195 case BPF_MAP_UPDATE_BATCH: 6196 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH); 6197 break; 6198 case BPF_MAP_DELETE_BATCH: 6199 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH); 6200 break; 6201 case BPF_LINK_CREATE: 6202 err = link_create(&attr, uattr); 6203 break; 6204 case BPF_LINK_UPDATE: 6205 err = link_update(&attr); 6206 break; 6207 case BPF_LINK_GET_FD_BY_ID: 6208 err = bpf_link_get_fd_by_id(&attr); 6209 break; 6210 case BPF_LINK_GET_NEXT_ID: 6211 err = bpf_obj_get_next_id(&attr, uattr.user, 6212 &link_idr, &link_idr_lock); 6213 break; 6214 case BPF_ENABLE_STATS: 6215 err = bpf_enable_stats(&attr); 6216 break; 6217 case BPF_ITER_CREATE: 6218 err = bpf_iter_create(&attr); 6219 break; 6220 case BPF_LINK_DETACH: 6221 err = link_detach(&attr); 6222 break; 6223 case BPF_PROG_BIND_MAP: 6224 err = bpf_prog_bind_map(&attr); 6225 break; 6226 case BPF_TOKEN_CREATE: 6227 err = token_create(&attr); 6228 break; 6229 case BPF_PROG_STREAM_READ_BY_FD: 6230 err = prog_stream_read(&attr); 6231 break; 6232 default: 6233 err = -EINVAL; 6234 break; 6235 } 6236 6237 return err; 6238 } 6239 6240 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) 6241 { 6242 return __sys_bpf(cmd, USER_BPFPTR(uattr), size); 6243 } 6244 6245 static bool syscall_prog_is_valid_access(int off, int size, 6246 enum bpf_access_type type, 6247 const struct bpf_prog *prog, 6248 struct bpf_insn_access_aux *info) 6249 { 6250 if (off < 0 || off >= U16_MAX) 6251 return false; 6252 if (off % size != 0) 6253 return false; 6254 return true; 6255 } 6256 6257 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) 6258 { 6259 switch (cmd) { 6260 case BPF_MAP_CREATE: 6261 case BPF_MAP_DELETE_ELEM: 6262 case BPF_MAP_UPDATE_ELEM: 6263 case BPF_MAP_FREEZE: 6264 case BPF_MAP_GET_FD_BY_ID: 6265 case BPF_PROG_LOAD: 6266 case BPF_BTF_LOAD: 6267 case BPF_LINK_CREATE: 6268 case BPF_RAW_TRACEPOINT_OPEN: 6269 break; 6270 default: 6271 return -EINVAL; 6272 } 6273 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); 6274 } 6275 6276 6277 /* To shut up -Wmissing-prototypes. 6278 * This function is used by the kernel light skeleton 6279 * to load bpf programs when modules are loaded or during kernel boot. 6280 * See tools/lib/bpf/skel_internal.h 6281 */ 6282 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size); 6283 6284 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) 6285 { 6286 struct bpf_prog * __maybe_unused prog; 6287 struct bpf_tramp_run_ctx __maybe_unused run_ctx; 6288 6289 switch (cmd) { 6290 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */ 6291 case BPF_PROG_TEST_RUN: 6292 if (attr->test.data_in || attr->test.data_out || 6293 attr->test.ctx_out || attr->test.duration || 6294 attr->test.repeat || attr->test.flags) 6295 return -EINVAL; 6296 6297 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL); 6298 if (IS_ERR(prog)) 6299 return PTR_ERR(prog); 6300 6301 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset || 6302 attr->test.ctx_size_in > U16_MAX) { 6303 bpf_prog_put(prog); 6304 return -EINVAL; 6305 } 6306 6307 run_ctx.bpf_cookie = 0; 6308 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) { 6309 /* recursion detected */ 6310 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx); 6311 bpf_prog_put(prog); 6312 return -EBUSY; 6313 } 6314 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in); 6315 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */, 6316 &run_ctx); 6317 bpf_prog_put(prog); 6318 return 0; 6319 #endif 6320 default: 6321 return ____bpf_sys_bpf(cmd, attr, size); 6322 } 6323 } 6324 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); 6325 6326 static const struct bpf_func_proto bpf_sys_bpf_proto = { 6327 .func = bpf_sys_bpf, 6328 .gpl_only = false, 6329 .ret_type = RET_INTEGER, 6330 .arg1_type = ARG_ANYTHING, 6331 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, 6332 .arg3_type = ARG_CONST_SIZE, 6333 }; 6334 6335 const struct bpf_func_proto * __weak 6336 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6337 { 6338 return bpf_base_func_proto(func_id, prog); 6339 } 6340 6341 BPF_CALL_1(bpf_sys_close, u32, fd) 6342 { 6343 /* When bpf program calls this helper there should not be 6344 * an fdget() without matching completed fdput(). 6345 * This helper is allowed in the following callchain only: 6346 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close 6347 */ 6348 return close_fd(fd); 6349 } 6350 6351 static const struct bpf_func_proto bpf_sys_close_proto = { 6352 .func = bpf_sys_close, 6353 .gpl_only = false, 6354 .ret_type = RET_INTEGER, 6355 .arg1_type = ARG_ANYTHING, 6356 }; 6357 6358 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res) 6359 { 6360 *res = 0; 6361 if (flags) 6362 return -EINVAL; 6363 6364 if (name_sz <= 1 || name[name_sz - 1]) 6365 return -EINVAL; 6366 6367 if (!bpf_dump_raw_ok(current_cred())) 6368 return -EPERM; 6369 6370 *res = kallsyms_lookup_name(name); 6371 return *res ? 0 : -ENOENT; 6372 } 6373 6374 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = { 6375 .func = bpf_kallsyms_lookup_name, 6376 .gpl_only = false, 6377 .ret_type = RET_INTEGER, 6378 .arg1_type = ARG_PTR_TO_MEM, 6379 .arg2_type = ARG_CONST_SIZE_OR_ZERO, 6380 .arg3_type = ARG_ANYTHING, 6381 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, 6382 .arg4_size = sizeof(u64), 6383 }; 6384 6385 static const struct bpf_func_proto * 6386 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 6387 { 6388 switch (func_id) { 6389 case BPF_FUNC_sys_bpf: 6390 return !bpf_token_capable(prog->aux->token, CAP_PERFMON) 6391 ? NULL : &bpf_sys_bpf_proto; 6392 case BPF_FUNC_btf_find_by_name_kind: 6393 return &bpf_btf_find_by_name_kind_proto; 6394 case BPF_FUNC_sys_close: 6395 return &bpf_sys_close_proto; 6396 case BPF_FUNC_kallsyms_lookup_name: 6397 return &bpf_kallsyms_lookup_name_proto; 6398 default: 6399 return tracing_prog_func_proto(func_id, prog); 6400 } 6401 } 6402 6403 const struct bpf_verifier_ops bpf_syscall_verifier_ops = { 6404 .get_func_proto = syscall_prog_func_proto, 6405 .is_valid_access = syscall_prog_is_valid_access, 6406 }; 6407 6408 const struct bpf_prog_ops bpf_syscall_prog_ops = { 6409 .test_run = bpf_prog_test_run_syscall, 6410 }; 6411 6412 #ifdef CONFIG_SYSCTL 6413 static int bpf_stats_handler(const struct ctl_table *table, int write, 6414 void *buffer, size_t *lenp, loff_t *ppos) 6415 { 6416 struct static_key *key = (struct static_key *)table->data; 6417 static int saved_val; 6418 int val, ret; 6419 struct ctl_table tmp = { 6420 .data = &val, 6421 .maxlen = sizeof(val), 6422 .mode = table->mode, 6423 .extra1 = SYSCTL_ZERO, 6424 .extra2 = SYSCTL_ONE, 6425 }; 6426 6427 if (write && !capable(CAP_SYS_ADMIN)) 6428 return -EPERM; 6429 6430 mutex_lock(&bpf_stats_enabled_mutex); 6431 val = saved_val; 6432 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6433 if (write && !ret && val != saved_val) { 6434 if (val) 6435 static_key_slow_inc(key); 6436 else 6437 static_key_slow_dec(key); 6438 saved_val = val; 6439 } 6440 mutex_unlock(&bpf_stats_enabled_mutex); 6441 return ret; 6442 } 6443 6444 void __weak unpriv_ebpf_notify(int new_state) 6445 { 6446 } 6447 6448 static int bpf_unpriv_handler(const struct ctl_table *table, int write, 6449 void *buffer, size_t *lenp, loff_t *ppos) 6450 { 6451 int ret, unpriv_enable = *(int *)table->data; 6452 bool locked_state = unpriv_enable == 1; 6453 struct ctl_table tmp = *table; 6454 6455 if (write && !capable(CAP_SYS_ADMIN)) 6456 return -EPERM; 6457 6458 tmp.data = &unpriv_enable; 6459 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); 6460 if (write && !ret) { 6461 if (locked_state && unpriv_enable != 1) 6462 return -EPERM; 6463 *(int *)table->data = unpriv_enable; 6464 } 6465 6466 if (write) 6467 unpriv_ebpf_notify(unpriv_enable); 6468 6469 return ret; 6470 } 6471 6472 static const struct ctl_table bpf_syscall_table[] = { 6473 { 6474 .procname = "unprivileged_bpf_disabled", 6475 .data = &sysctl_unprivileged_bpf_disabled, 6476 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled), 6477 .mode = 0644, 6478 .proc_handler = bpf_unpriv_handler, 6479 .extra1 = SYSCTL_ZERO, 6480 .extra2 = SYSCTL_TWO, 6481 }, 6482 { 6483 .procname = "bpf_stats_enabled", 6484 .data = &bpf_stats_enabled_key.key, 6485 .mode = 0644, 6486 .proc_handler = bpf_stats_handler, 6487 }, 6488 }; 6489 6490 static int __init bpf_syscall_sysctl_init(void) 6491 { 6492 register_sysctl_init("kernel", bpf_syscall_table); 6493 return 0; 6494 } 6495 late_initcall(bpf_syscall_sysctl_init); 6496 #endif /* CONFIG_SYSCTL */ 6497