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