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