1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 * Copyright (c) 2016,2017 Facebook 4 */ 5 #include <linux/bpf.h> 6 #include <linux/btf.h> 7 #include <linux/err.h> 8 #include <linux/slab.h> 9 #include <linux/mm.h> 10 #include <linux/filter.h> 11 #include <linux/perf_event.h> 12 #include <uapi/linux/btf.h> 13 #include <linux/rcupdate_trace.h> 14 #include <linux/btf_ids.h> 15 #include <crypto/sha2.h> 16 17 #include "map_in_map.h" 18 19 #define ARRAY_CREATE_FLAG_MASK \ 20 (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \ 21 BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP) 22 23 static void bpf_array_free_percpu(struct bpf_array *array) 24 { 25 int i; 26 27 for (i = 0; i < array->map.max_entries; i++) { 28 free_percpu(array->pptrs[i]); 29 cond_resched(); 30 } 31 } 32 33 static int bpf_array_alloc_percpu(struct bpf_array *array) 34 { 35 void __percpu *ptr; 36 int i; 37 38 for (i = 0; i < array->map.max_entries; i++) { 39 ptr = bpf_map_alloc_percpu(&array->map, array->elem_size, 8, 40 GFP_USER | __GFP_NOWARN); 41 if (!ptr) { 42 bpf_array_free_percpu(array); 43 return -ENOMEM; 44 } 45 array->pptrs[i] = ptr; 46 cond_resched(); 47 } 48 49 return 0; 50 } 51 52 /* Called from syscall */ 53 int array_map_alloc_check(union bpf_attr *attr) 54 { 55 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 56 int numa_node = bpf_map_attr_numa_node(attr); 57 58 /* check sanity of attributes */ 59 if (attr->max_entries == 0 || attr->key_size != 4 || 60 attr->value_size == 0 || 61 attr->map_flags & ~ARRAY_CREATE_FLAG_MASK || 62 !bpf_map_flags_access_ok(attr->map_flags) || 63 (percpu && numa_node != NUMA_NO_NODE)) 64 return -EINVAL; 65 66 if (attr->map_type != BPF_MAP_TYPE_ARRAY && 67 attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP)) 68 return -EINVAL; 69 70 if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY && 71 attr->map_flags & BPF_F_PRESERVE_ELEMS) 72 return -EINVAL; 73 74 /* avoid overflow on round_up(map->value_size) */ 75 if (attr->value_size > INT_MAX) 76 return -E2BIG; 77 /* percpu map value size is bound by PCPU_MIN_UNIT_SIZE */ 78 if (percpu && round_up(attr->value_size, 8) > PCPU_MIN_UNIT_SIZE) 79 return -E2BIG; 80 81 return 0; 82 } 83 84 static struct bpf_map *array_map_alloc(union bpf_attr *attr) 85 { 86 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 87 int numa_node = bpf_map_attr_numa_node(attr); 88 u32 elem_size, index_mask, max_entries; 89 bool bypass_spec_v1 = bpf_bypass_spec_v1(NULL); 90 u64 array_size, mask64; 91 struct bpf_array *array; 92 93 elem_size = round_up(attr->value_size, 8); 94 95 max_entries = attr->max_entries; 96 97 /* On 32 bit archs roundup_pow_of_two() with max_entries that has 98 * upper most bit set in u32 space is undefined behavior due to 99 * resulting 1U << 32, so do it manually here in u64 space. 100 */ 101 mask64 = fls_long(max_entries - 1); 102 mask64 = 1ULL << mask64; 103 mask64 -= 1; 104 105 index_mask = mask64; 106 if (!bypass_spec_v1) { 107 /* round up array size to nearest power of 2, 108 * since cpu will speculate within index_mask limits 109 */ 110 max_entries = index_mask + 1; 111 /* Check for overflows. */ 112 if (max_entries < attr->max_entries) 113 return ERR_PTR(-E2BIG); 114 } 115 116 array_size = sizeof(*array); 117 if (percpu) { 118 array_size += (u64) max_entries * sizeof(void *); 119 } else { 120 /* rely on vmalloc() to return page-aligned memory and 121 * ensure array->value is exactly page-aligned 122 */ 123 if (attr->map_flags & BPF_F_MMAPABLE) { 124 array_size = PAGE_ALIGN(array_size); 125 array_size += PAGE_ALIGN((u64) max_entries * elem_size); 126 } else { 127 array_size += (u64) max_entries * elem_size; 128 } 129 } 130 131 /* allocate all map elements and zero-initialize them */ 132 if (attr->map_flags & BPF_F_MMAPABLE) { 133 void *data; 134 135 /* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */ 136 data = bpf_map_area_mmapable_alloc(array_size, numa_node); 137 if (!data) 138 return ERR_PTR(-ENOMEM); 139 array = data + PAGE_ALIGN(sizeof(struct bpf_array)) 140 - offsetof(struct bpf_array, value); 141 } else { 142 array = bpf_map_area_alloc(array_size, numa_node); 143 } 144 if (!array) 145 return ERR_PTR(-ENOMEM); 146 array->index_mask = index_mask; 147 array->map.bypass_spec_v1 = bypass_spec_v1; 148 149 /* copy mandatory map attributes */ 150 bpf_map_init_from_attr(&array->map, attr); 151 array->elem_size = elem_size; 152 153 if (percpu && bpf_array_alloc_percpu(array)) { 154 bpf_map_area_free(array); 155 return ERR_PTR(-ENOMEM); 156 } 157 158 return &array->map; 159 } 160 161 static void *array_map_elem_ptr(struct bpf_array* array, u32 index) 162 { 163 return array->value + (u64)array->elem_size * index; 164 } 165 166 /* Called from syscall or from eBPF program */ 167 static void *array_map_lookup_elem(struct bpf_map *map, void *key) 168 { 169 struct bpf_array *array = container_of(map, struct bpf_array, map); 170 u32 index = *(u32 *)key; 171 172 if (unlikely(index >= array->map.max_entries)) 173 return NULL; 174 175 return array->value + (u64)array->elem_size * (index & array->index_mask); 176 } 177 178 static int array_map_get_hash(struct bpf_map *map) 179 { 180 struct bpf_array *array = container_of(map, struct bpf_array, map); 181 182 sha256(array->value, (u64)array->elem_size * array->map.max_entries, 183 array->map.sha); 184 return 0; 185 } 186 187 static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm, 188 u32 off) 189 { 190 struct bpf_array *array = container_of(map, struct bpf_array, map); 191 192 if (map->max_entries != 1) 193 return -ENOTSUPP; 194 if (off >= map->value_size) 195 return -EINVAL; 196 197 *imm = (unsigned long)array->value; 198 return 0; 199 } 200 201 static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm, 202 u32 *off) 203 { 204 struct bpf_array *array = container_of(map, struct bpf_array, map); 205 u64 base = (unsigned long)array->value; 206 u64 range = array->elem_size; 207 208 if (map->max_entries != 1) 209 return -ENOTSUPP; 210 if (imm < base || imm >= base + range) 211 return -ENOENT; 212 213 *off = imm - base; 214 return 0; 215 } 216 217 /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */ 218 static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) 219 { 220 struct bpf_array *array = container_of(map, struct bpf_array, map); 221 struct bpf_insn *insn = insn_buf; 222 u32 elem_size = array->elem_size; 223 const int ret = BPF_REG_0; 224 const int map_ptr = BPF_REG_1; 225 const int index = BPF_REG_2; 226 227 if (map->map_flags & BPF_F_INNER_MAP) 228 return -EOPNOTSUPP; 229 230 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); 231 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); 232 if (!map->bypass_spec_v1) { 233 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4); 234 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); 235 } else { 236 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3); 237 } 238 239 if (is_power_of_2(elem_size)) { 240 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); 241 } else { 242 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); 243 } 244 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); 245 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); 246 *insn++ = BPF_MOV64_IMM(ret, 0); 247 return insn - insn_buf; 248 } 249 250 /* Called from eBPF program */ 251 static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key) 252 { 253 struct bpf_array *array = container_of(map, struct bpf_array, map); 254 u32 index = *(u32 *)key; 255 256 if (unlikely(index >= array->map.max_entries)) 257 return NULL; 258 259 return this_cpu_ptr(array->pptrs[index & array->index_mask]); 260 } 261 262 /* emit BPF instructions equivalent to C code of percpu_array_map_lookup_elem() */ 263 static int percpu_array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) 264 { 265 struct bpf_array *array = container_of(map, struct bpf_array, map); 266 struct bpf_insn *insn = insn_buf; 267 268 if (!bpf_jit_supports_percpu_insn()) 269 return -EOPNOTSUPP; 270 271 if (map->map_flags & BPF_F_INNER_MAP) 272 return -EOPNOTSUPP; 273 274 BUILD_BUG_ON(offsetof(struct bpf_array, map) != 0); 275 *insn++ = BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, offsetof(struct bpf_array, pptrs)); 276 277 *insn++ = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0); 278 if (!map->bypass_spec_v1) { 279 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 6); 280 *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_0, array->index_mask); 281 } else { 282 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 5); 283 } 284 285 *insn++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_0, 3); 286 *insn++ = BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1); 287 *insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0); 288 *insn++ = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0); 289 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); 290 *insn++ = BPF_MOV64_IMM(BPF_REG_0, 0); 291 return insn - insn_buf; 292 } 293 294 static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu) 295 { 296 struct bpf_array *array = container_of(map, struct bpf_array, map); 297 u32 index = *(u32 *)key; 298 299 if (cpu >= nr_cpu_ids) 300 return NULL; 301 302 if (unlikely(index >= array->map.max_entries)) 303 return NULL; 304 305 return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu); 306 } 307 308 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, u64 map_flags) 309 { 310 struct bpf_array *array = container_of(map, struct bpf_array, map); 311 u32 index = *(u32 *)key; 312 void __percpu *pptr; 313 int cpu, off = 0; 314 u32 size; 315 316 if (unlikely(index >= array->map.max_entries)) 317 return -ENOENT; 318 319 /* per_cpu areas are zero-filled and bpf programs can only 320 * access 'value_size' of them, so copying rounded areas 321 * will not leak any kernel data 322 */ 323 size = array->elem_size; 324 rcu_read_lock(); 325 pptr = array->pptrs[index & array->index_mask]; 326 if (map_flags & BPF_F_CPU) { 327 cpu = map_flags >> 32; 328 copy_map_value(map, value, per_cpu_ptr(pptr, cpu)); 329 check_and_init_map_value(map, value); 330 goto unlock; 331 } 332 for_each_possible_cpu(cpu) { 333 copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu)); 334 check_and_init_map_value(map, value + off); 335 off += size; 336 } 337 unlock: 338 rcu_read_unlock(); 339 return 0; 340 } 341 342 /* Called from syscall */ 343 int bpf_array_get_next_key(struct bpf_map *map, void *key, void *next_key) 344 { 345 u32 index = key ? *(u32 *)key : U32_MAX; 346 u32 *next = (u32 *)next_key; 347 348 if (index >= map->max_entries) { 349 *next = 0; 350 return 0; 351 } 352 353 if (index == map->max_entries - 1) 354 return -ENOENT; 355 356 *next = index + 1; 357 return 0; 358 } 359 360 /* Called from syscall or from eBPF program */ 361 static long array_map_update_elem(struct bpf_map *map, void *key, void *value, 362 u64 map_flags) 363 { 364 struct bpf_array *array = container_of(map, struct bpf_array, map); 365 u32 index = *(u32 *)key; 366 char *val; 367 368 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST)) 369 /* unknown flags */ 370 return -EINVAL; 371 372 if (unlikely(index >= array->map.max_entries)) 373 /* all elements were pre-allocated, cannot insert a new one */ 374 return -E2BIG; 375 376 if (unlikely(map_flags & BPF_NOEXIST)) 377 /* all elements already exist */ 378 return -EEXIST; 379 380 if (unlikely((map_flags & BPF_F_LOCK) && 381 !btf_record_has_field(map->record, BPF_SPIN_LOCK))) 382 return -EINVAL; 383 384 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 385 val = this_cpu_ptr(array->pptrs[index & array->index_mask]); 386 copy_map_value(map, val, value); 387 bpf_obj_cancel_fields(map, val); 388 } else { 389 val = array->value + 390 (u64)array->elem_size * (index & array->index_mask); 391 if (map_flags & BPF_F_LOCK) 392 copy_map_value_locked(map, val, value, false); 393 else 394 copy_map_value(map, val, value); 395 bpf_obj_cancel_fields(map, val); 396 } 397 return 0; 398 } 399 400 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 401 u64 map_flags) 402 { 403 struct bpf_array *array = container_of(map, struct bpf_array, map); 404 u32 index = *(u32 *)key; 405 void __percpu *pptr; 406 void *ptr, *val; 407 u32 size; 408 int cpu; 409 410 if (unlikely((map_flags & BPF_F_LOCK) || (u32)map_flags > BPF_F_ALL_CPUS)) 411 /* unknown flags */ 412 return -EINVAL; 413 414 if (unlikely(index >= array->map.max_entries)) 415 /* all elements were pre-allocated, cannot insert a new one */ 416 return -E2BIG; 417 418 if (unlikely(map_flags == BPF_NOEXIST)) 419 /* all elements already exist */ 420 return -EEXIST; 421 422 /* the user space will provide round_up(value_size, 8) bytes that 423 * will be copied into per-cpu area. bpf programs can only access 424 * value_size of it. During lookup the same extra bytes will be 425 * returned or zeros which were zero-filled by percpu_alloc, 426 * so no kernel data leaks possible 427 */ 428 size = array->elem_size; 429 rcu_read_lock(); 430 pptr = array->pptrs[index & array->index_mask]; 431 if (map_flags & BPF_F_CPU) { 432 cpu = map_flags >> 32; 433 ptr = per_cpu_ptr(pptr, cpu); 434 copy_map_value(map, ptr, value); 435 bpf_obj_cancel_fields(map, ptr); 436 goto unlock; 437 } 438 for_each_possible_cpu(cpu) { 439 ptr = per_cpu_ptr(pptr, cpu); 440 val = (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu; 441 copy_map_value(map, ptr, val); 442 bpf_obj_cancel_fields(map, ptr); 443 } 444 unlock: 445 rcu_read_unlock(); 446 return 0; 447 } 448 449 /* Called from syscall or from eBPF program */ 450 static long array_map_delete_elem(struct bpf_map *map, void *key) 451 { 452 return -EINVAL; 453 } 454 455 static void *array_map_vmalloc_addr(struct bpf_array *array) 456 { 457 return (void *)round_down((unsigned long)array, PAGE_SIZE); 458 } 459 460 static void array_map_free_internal_structs(struct bpf_map *map) 461 { 462 struct bpf_array *array = container_of(map, struct bpf_array, map); 463 int i; 464 465 /* We only free internal structs on uref dropping to zero */ 466 if (!bpf_map_has_internal_structs(map)) 467 return; 468 469 for (i = 0; i < array->map.max_entries; i++) 470 bpf_map_free_internal_structs(map, array_map_elem_ptr(array, i)); 471 } 472 473 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ 474 static void array_map_free(struct bpf_map *map) 475 { 476 struct bpf_array *array = container_of(map, struct bpf_array, map); 477 int i; 478 479 if (!IS_ERR_OR_NULL(map->record)) { 480 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 481 for (i = 0; i < array->map.max_entries; i++) { 482 void __percpu *pptr = array->pptrs[i & array->index_mask]; 483 int cpu; 484 485 for_each_possible_cpu(cpu) { 486 bpf_obj_free_fields(map->record, per_cpu_ptr(pptr, cpu)); 487 cond_resched(); 488 } 489 } 490 } else { 491 for (i = 0; i < array->map.max_entries; i++) 492 bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i)); 493 } 494 } 495 496 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) 497 bpf_array_free_percpu(array); 498 499 if (array->map.map_flags & BPF_F_MMAPABLE) 500 bpf_map_area_free(array_map_vmalloc_addr(array)); 501 else 502 bpf_map_area_free(array); 503 } 504 505 static void array_map_seq_show_elem(struct bpf_map *map, void *key, 506 struct seq_file *m) 507 { 508 void *value; 509 510 rcu_read_lock(); 511 512 value = array_map_lookup_elem(map, key); 513 if (!value) { 514 rcu_read_unlock(); 515 return; 516 } 517 518 if (map->btf_key_type_id) 519 seq_printf(m, "%u: ", *(u32 *)key); 520 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m); 521 seq_putc(m, '\n'); 522 523 rcu_read_unlock(); 524 } 525 526 static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key, 527 struct seq_file *m) 528 { 529 struct bpf_array *array = container_of(map, struct bpf_array, map); 530 u32 index = *(u32 *)key; 531 void __percpu *pptr; 532 int cpu; 533 534 rcu_read_lock(); 535 536 seq_printf(m, "%u: {\n", *(u32 *)key); 537 pptr = array->pptrs[index & array->index_mask]; 538 for_each_possible_cpu(cpu) { 539 seq_printf(m, "\tcpu%d: ", cpu); 540 btf_type_seq_show(map->btf, map->btf_value_type_id, 541 per_cpu_ptr(pptr, cpu), m); 542 seq_putc(m, '\n'); 543 } 544 seq_puts(m, "}\n"); 545 546 rcu_read_unlock(); 547 } 548 549 static int array_map_check_btf(struct bpf_map *map, 550 const struct btf *btf, 551 const struct btf_type *key_type, 552 const struct btf_type *value_type) 553 { 554 /* One exception for keyless BTF: .bss/.data/.rodata map */ 555 if (btf_type_is_void(key_type)) { 556 if (map->map_type != BPF_MAP_TYPE_ARRAY || 557 map->max_entries != 1) 558 return -EINVAL; 559 560 if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC) 561 return -EINVAL; 562 563 return 0; 564 } 565 566 /* 567 * Bpf array can only take a u32 key. This check makes sure 568 * that the btf matches the attr used during map_create. 569 */ 570 if (!btf_type_is_i32(key_type)) 571 return -EINVAL; 572 573 return 0; 574 } 575 576 static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma) 577 { 578 struct bpf_array *array = container_of(map, struct bpf_array, map); 579 pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT; 580 581 if (!(map->map_flags & BPF_F_MMAPABLE)) 582 return -EINVAL; 583 584 if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) > 585 PAGE_ALIGN((u64)array->map.max_entries * array->elem_size)) 586 return -EINVAL; 587 588 return remap_vmalloc_range(vma, array_map_vmalloc_addr(array), 589 vma->vm_pgoff + pgoff); 590 } 591 592 static bool array_map_meta_equal(const struct bpf_map *meta0, 593 const struct bpf_map *meta1) 594 { 595 if (!bpf_map_meta_equal(meta0, meta1)) 596 return false; 597 return meta0->map_flags & BPF_F_INNER_MAP ? true : 598 meta0->max_entries == meta1->max_entries; 599 } 600 601 struct bpf_iter_seq_array_map_info { 602 struct bpf_map *map; 603 void *percpu_value_buf; 604 u32 index; 605 }; 606 607 static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos) 608 { 609 struct bpf_iter_seq_array_map_info *info = seq->private; 610 struct bpf_map *map = info->map; 611 struct bpf_array *array; 612 u32 index; 613 614 if (info->index >= map->max_entries) 615 return NULL; 616 617 if (*pos == 0) 618 ++*pos; 619 array = container_of(map, struct bpf_array, map); 620 index = info->index & array->index_mask; 621 if (info->percpu_value_buf) 622 return (void *)(uintptr_t)array->pptrs[index]; 623 return array_map_elem_ptr(array, index); 624 } 625 626 static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) 627 { 628 struct bpf_iter_seq_array_map_info *info = seq->private; 629 struct bpf_map *map = info->map; 630 struct bpf_array *array; 631 u32 index; 632 633 ++*pos; 634 ++info->index; 635 if (info->index >= map->max_entries) 636 return NULL; 637 638 array = container_of(map, struct bpf_array, map); 639 index = info->index & array->index_mask; 640 if (info->percpu_value_buf) 641 return (void *)(uintptr_t)array->pptrs[index]; 642 return array_map_elem_ptr(array, index); 643 } 644 645 static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) 646 { 647 struct bpf_iter_seq_array_map_info *info = seq->private; 648 struct bpf_iter__bpf_map_elem ctx = {}; 649 struct bpf_map *map = info->map; 650 struct bpf_array *array = container_of(map, struct bpf_array, map); 651 struct bpf_iter_meta meta; 652 struct bpf_prog *prog; 653 int off = 0, cpu = 0; 654 void __percpu *pptr; 655 u32 size; 656 657 meta.seq = seq; 658 prog = bpf_iter_get_info(&meta, v == NULL); 659 if (!prog) 660 return 0; 661 662 ctx.meta = &meta; 663 ctx.map = info->map; 664 if (v) { 665 ctx.key = &info->index; 666 667 if (!info->percpu_value_buf) { 668 ctx.value = v; 669 } else { 670 pptr = (void __percpu *)(uintptr_t)v; 671 size = array->elem_size; 672 for_each_possible_cpu(cpu) { 673 copy_map_value_long(map, info->percpu_value_buf + off, 674 per_cpu_ptr(pptr, cpu)); 675 check_and_init_map_value(map, info->percpu_value_buf + off); 676 off += size; 677 } 678 ctx.value = info->percpu_value_buf; 679 } 680 } 681 682 return bpf_iter_run_prog(prog, &ctx); 683 } 684 685 static int bpf_array_map_seq_show(struct seq_file *seq, void *v) 686 { 687 return __bpf_array_map_seq_show(seq, v); 688 } 689 690 static void bpf_array_map_seq_stop(struct seq_file *seq, void *v) 691 { 692 if (!v) 693 (void)__bpf_array_map_seq_show(seq, NULL); 694 } 695 696 static int bpf_iter_init_array_map(void *priv_data, 697 struct bpf_iter_aux_info *aux) 698 { 699 struct bpf_iter_seq_array_map_info *seq_info = priv_data; 700 struct bpf_map *map = aux->map; 701 struct bpf_array *array = container_of(map, struct bpf_array, map); 702 void *value_buf; 703 u32 buf_size; 704 705 if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 706 buf_size = array->elem_size * num_possible_cpus(); 707 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN); 708 if (!value_buf) 709 return -ENOMEM; 710 711 seq_info->percpu_value_buf = value_buf; 712 } 713 714 /* bpf_iter_attach_map() acquires a map uref, and the uref may be 715 * released before or in the middle of iterating map elements, so 716 * acquire an extra map uref for iterator. 717 */ 718 bpf_map_inc_with_uref(map); 719 seq_info->map = map; 720 return 0; 721 } 722 723 static void bpf_iter_fini_array_map(void *priv_data) 724 { 725 struct bpf_iter_seq_array_map_info *seq_info = priv_data; 726 727 bpf_map_put_with_uref(seq_info->map); 728 kfree(seq_info->percpu_value_buf); 729 } 730 731 static const struct seq_operations bpf_array_map_seq_ops = { 732 .start = bpf_array_map_seq_start, 733 .next = bpf_array_map_seq_next, 734 .stop = bpf_array_map_seq_stop, 735 .show = bpf_array_map_seq_show, 736 }; 737 738 static const struct bpf_iter_seq_info iter_seq_info = { 739 .seq_ops = &bpf_array_map_seq_ops, 740 .init_seq_private = bpf_iter_init_array_map, 741 .fini_seq_private = bpf_iter_fini_array_map, 742 .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info), 743 }; 744 745 static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn, 746 void *callback_ctx, u64 flags) 747 { 748 u32 i, key, num_elems = 0; 749 struct bpf_array *array; 750 bool is_percpu; 751 u64 ret = 0; 752 void *val; 753 754 cant_migrate(); 755 756 if (flags != 0) 757 return -EINVAL; 758 759 is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 760 array = container_of(map, struct bpf_array, map); 761 for (i = 0; i < map->max_entries; i++) { 762 if (is_percpu) 763 val = this_cpu_ptr(array->pptrs[i]); 764 else 765 val = array_map_elem_ptr(array, i); 766 num_elems++; 767 key = i; 768 ret = callback_fn((u64)(long)map, (u64)(long)&key, 769 (u64)(long)val, (u64)(long)callback_ctx, 0); 770 /* return value: 0 - continue, 1 - stop and return */ 771 if (ret) 772 break; 773 } 774 775 return num_elems; 776 } 777 778 static u64 array_map_mem_usage(const struct bpf_map *map) 779 { 780 struct bpf_array *array = container_of(map, struct bpf_array, map); 781 bool percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 782 u32 elem_size = array->elem_size; 783 u64 entries = map->max_entries; 784 u64 usage = sizeof(*array); 785 786 if (percpu) { 787 usage += entries * sizeof(void *); 788 usage += entries * elem_size * num_possible_cpus(); 789 } else { 790 if (map->map_flags & BPF_F_MMAPABLE) { 791 usage = PAGE_ALIGN(usage); 792 usage += PAGE_ALIGN(entries * elem_size); 793 } else { 794 usage += entries * elem_size; 795 } 796 } 797 return usage; 798 } 799 800 BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array) 801 const struct bpf_map_ops array_map_ops = { 802 .map_meta_equal = array_map_meta_equal, 803 .map_alloc_check = array_map_alloc_check, 804 .map_alloc = array_map_alloc, 805 .map_free = array_map_free, 806 .map_get_next_key = bpf_array_get_next_key, 807 .map_release_uref = array_map_free_internal_structs, 808 .map_lookup_elem = array_map_lookup_elem, 809 .map_update_elem = array_map_update_elem, 810 .map_delete_elem = array_map_delete_elem, 811 .map_gen_lookup = array_map_gen_lookup, 812 .map_direct_value_addr = array_map_direct_value_addr, 813 .map_direct_value_meta = array_map_direct_value_meta, 814 .map_mmap = array_map_mmap, 815 .map_seq_show_elem = array_map_seq_show_elem, 816 .map_check_btf = array_map_check_btf, 817 .map_lookup_batch = generic_map_lookup_batch, 818 .map_update_batch = generic_map_update_batch, 819 .map_set_for_each_callback_args = map_set_for_each_callback_args, 820 .map_for_each_callback = bpf_for_each_array_elem, 821 .map_mem_usage = array_map_mem_usage, 822 .map_btf_id = &array_map_btf_ids[0], 823 .iter_seq_info = &iter_seq_info, 824 .map_get_hash = &array_map_get_hash, 825 }; 826 827 const struct bpf_map_ops percpu_array_map_ops = { 828 .map_meta_equal = array_map_meta_equal, 829 .map_alloc_check = array_map_alloc_check, 830 .map_alloc = array_map_alloc, 831 .map_free = array_map_free, 832 .map_get_next_key = bpf_array_get_next_key, 833 .map_lookup_elem = percpu_array_map_lookup_elem, 834 .map_gen_lookup = percpu_array_map_gen_lookup, 835 .map_update_elem = array_map_update_elem, 836 .map_delete_elem = array_map_delete_elem, 837 .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem, 838 .map_seq_show_elem = percpu_array_map_seq_show_elem, 839 .map_check_btf = array_map_check_btf, 840 .map_lookup_batch = generic_map_lookup_batch, 841 .map_update_batch = generic_map_update_batch, 842 .map_set_for_each_callback_args = map_set_for_each_callback_args, 843 .map_for_each_callback = bpf_for_each_array_elem, 844 .map_mem_usage = array_map_mem_usage, 845 .map_btf_id = &array_map_btf_ids[0], 846 .iter_seq_info = &iter_seq_info, 847 }; 848 849 static int fd_array_map_alloc_check(union bpf_attr *attr) 850 { 851 /* only file descriptors can be stored in this type of map */ 852 if (attr->value_size != sizeof(u32)) 853 return -EINVAL; 854 /* Program read-only/write-only not supported for special maps yet. */ 855 if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) 856 return -EINVAL; 857 return array_map_alloc_check(attr); 858 } 859 860 static void fd_array_map_free(struct bpf_map *map) 861 { 862 struct bpf_array *array = container_of(map, struct bpf_array, map); 863 int i; 864 865 /* make sure it's empty */ 866 for (i = 0; i < array->map.max_entries; i++) 867 BUG_ON(array->ptrs[i] != NULL); 868 869 bpf_map_area_free(array); 870 } 871 872 static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) 873 { 874 return ERR_PTR(-EOPNOTSUPP); 875 } 876 877 /* only called from syscall */ 878 int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) 879 { 880 void **elem, *ptr; 881 int ret = 0; 882 883 if (!map->ops->map_fd_sys_lookup_elem) 884 return -ENOTSUPP; 885 886 rcu_read_lock(); 887 elem = array_map_lookup_elem(map, key); 888 if (elem && (ptr = READ_ONCE(*elem))) 889 *value = map->ops->map_fd_sys_lookup_elem(ptr); 890 else 891 ret = -ENOENT; 892 rcu_read_unlock(); 893 894 return ret; 895 } 896 897 /* only called from syscall */ 898 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, 899 void *key, void *value, u64 map_flags) 900 { 901 struct bpf_array *array = container_of(map, struct bpf_array, map); 902 void *new_ptr, *old_ptr; 903 u32 index = *(u32 *)key, ufd; 904 905 if (map_flags != BPF_ANY) 906 return -EINVAL; 907 908 if (index >= array->map.max_entries) 909 return -E2BIG; 910 911 ufd = *(u32 *)value; 912 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd); 913 if (IS_ERR(new_ptr)) 914 return PTR_ERR(new_ptr); 915 916 if (map->ops->map_poke_run) { 917 mutex_lock(&array->aux->poke_mutex); 918 old_ptr = xchg(array->ptrs + index, new_ptr); 919 map->ops->map_poke_run(map, index, old_ptr, new_ptr); 920 mutex_unlock(&array->aux->poke_mutex); 921 } else { 922 old_ptr = xchg(array->ptrs + index, new_ptr); 923 } 924 925 if (old_ptr) 926 map->ops->map_fd_put_ptr(map, old_ptr, true); 927 return 0; 928 } 929 930 static long __fd_array_map_delete_elem(struct bpf_map *map, void *key, bool need_defer) 931 { 932 struct bpf_array *array = container_of(map, struct bpf_array, map); 933 void *old_ptr; 934 u32 index = *(u32 *)key; 935 936 if (index >= array->map.max_entries) 937 return -E2BIG; 938 939 if (map->ops->map_poke_run) { 940 mutex_lock(&array->aux->poke_mutex); 941 old_ptr = xchg(array->ptrs + index, NULL); 942 map->ops->map_poke_run(map, index, old_ptr, NULL); 943 mutex_unlock(&array->aux->poke_mutex); 944 } else { 945 old_ptr = xchg(array->ptrs + index, NULL); 946 } 947 948 if (old_ptr) { 949 map->ops->map_fd_put_ptr(map, old_ptr, need_defer); 950 return 0; 951 } else { 952 return -ENOENT; 953 } 954 } 955 956 static long fd_array_map_delete_elem(struct bpf_map *map, void *key) 957 { 958 return __fd_array_map_delete_elem(map, key, true); 959 } 960 961 static void *prog_fd_array_get_ptr(struct bpf_map *map, 962 struct file *map_file, int fd) 963 { 964 struct bpf_prog *prog = bpf_prog_get(fd); 965 bool is_extended; 966 967 if (IS_ERR(prog)) 968 return prog; 969 970 if (prog->type == BPF_PROG_TYPE_EXT || 971 !bpf_prog_map_compatible(map, prog)) { 972 bpf_prog_put(prog); 973 return ERR_PTR(-EINVAL); 974 } 975 976 mutex_lock(&prog->aux->ext_mutex); 977 is_extended = prog->aux->is_extended; 978 if (!is_extended) 979 prog->aux->prog_array_member_cnt++; 980 mutex_unlock(&prog->aux->ext_mutex); 981 if (is_extended) { 982 /* Extended prog can not be tail callee. It's to prevent a 983 * potential infinite loop like: 984 * tail callee prog entry -> tail callee prog subprog -> 985 * freplace prog entry --tailcall-> tail callee prog entry. 986 */ 987 bpf_prog_put(prog); 988 return ERR_PTR(-EBUSY); 989 } 990 991 return prog; 992 } 993 994 static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) 995 { 996 struct bpf_prog *prog = ptr; 997 998 mutex_lock(&prog->aux->ext_mutex); 999 prog->aux->prog_array_member_cnt--; 1000 mutex_unlock(&prog->aux->ext_mutex); 1001 /* bpf_prog is freed after one RCU or tasks trace grace period */ 1002 bpf_prog_put(prog); 1003 } 1004 1005 static u32 prog_fd_array_sys_lookup_elem(void *ptr) 1006 { 1007 return ((struct bpf_prog *)ptr)->aux->id; 1008 } 1009 1010 /* decrement refcnt of all bpf_progs that are stored in this map */ 1011 static void bpf_fd_array_map_clear(struct bpf_map *map, bool need_defer) 1012 { 1013 struct bpf_array *array = container_of(map, struct bpf_array, map); 1014 int i; 1015 1016 for (i = 0; i < array->map.max_entries; i++) { 1017 __fd_array_map_delete_elem(map, &i, need_defer); 1018 cond_resched(); 1019 } 1020 } 1021 1022 static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key, 1023 struct seq_file *m) 1024 { 1025 void **elem, *ptr; 1026 u32 prog_id; 1027 1028 rcu_read_lock(); 1029 1030 elem = array_map_lookup_elem(map, key); 1031 if (elem) { 1032 ptr = READ_ONCE(*elem); 1033 if (ptr) { 1034 seq_printf(m, "%u: ", *(u32 *)key); 1035 prog_id = prog_fd_array_sys_lookup_elem(ptr); 1036 btf_type_seq_show(map->btf, map->btf_value_type_id, 1037 &prog_id, m); 1038 seq_putc(m, '\n'); 1039 } 1040 } 1041 1042 rcu_read_unlock(); 1043 } 1044 1045 struct prog_poke_elem { 1046 struct list_head list; 1047 struct bpf_prog_aux *aux; 1048 }; 1049 1050 static int prog_array_map_poke_track(struct bpf_map *map, 1051 struct bpf_prog_aux *prog_aux) 1052 { 1053 struct prog_poke_elem *elem; 1054 struct bpf_array_aux *aux; 1055 int ret = 0; 1056 1057 aux = container_of(map, struct bpf_array, map)->aux; 1058 mutex_lock(&aux->poke_mutex); 1059 list_for_each_entry(elem, &aux->poke_progs, list) { 1060 if (elem->aux == prog_aux) 1061 goto out; 1062 } 1063 1064 elem = kmalloc_obj(*elem); 1065 if (!elem) { 1066 ret = -ENOMEM; 1067 goto out; 1068 } 1069 1070 INIT_LIST_HEAD(&elem->list); 1071 /* We must track the program's aux info at this point in time 1072 * since the program pointer itself may not be stable yet, see 1073 * also comment in prog_array_map_poke_run(). 1074 */ 1075 elem->aux = prog_aux; 1076 1077 list_add_tail(&elem->list, &aux->poke_progs); 1078 out: 1079 mutex_unlock(&aux->poke_mutex); 1080 return ret; 1081 } 1082 1083 static void prog_array_map_poke_untrack(struct bpf_map *map, 1084 struct bpf_prog_aux *prog_aux) 1085 { 1086 struct prog_poke_elem *elem, *tmp; 1087 struct bpf_array_aux *aux; 1088 1089 aux = container_of(map, struct bpf_array, map)->aux; 1090 mutex_lock(&aux->poke_mutex); 1091 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) { 1092 if (elem->aux == prog_aux) { 1093 list_del_init(&elem->list); 1094 kfree(elem); 1095 break; 1096 } 1097 } 1098 mutex_unlock(&aux->poke_mutex); 1099 } 1100 1101 void __weak bpf_arch_poke_desc_update(struct bpf_jit_poke_descriptor *poke, 1102 struct bpf_prog *new, struct bpf_prog *old) 1103 { 1104 WARN_ON_ONCE(1); 1105 } 1106 1107 static void prog_array_map_poke_run(struct bpf_map *map, u32 key, 1108 struct bpf_prog *old, 1109 struct bpf_prog *new) 1110 { 1111 struct prog_poke_elem *elem; 1112 struct bpf_array_aux *aux; 1113 1114 aux = container_of(map, struct bpf_array, map)->aux; 1115 WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex)); 1116 1117 list_for_each_entry(elem, &aux->poke_progs, list) { 1118 struct bpf_jit_poke_descriptor *poke; 1119 int i; 1120 1121 for (i = 0; i < elem->aux->size_poke_tab; i++) { 1122 poke = &elem->aux->poke_tab[i]; 1123 1124 /* Few things to be aware of: 1125 * 1126 * 1) We can only ever access aux in this context, but 1127 * not aux->prog since it might not be stable yet and 1128 * there could be danger of use after free otherwise. 1129 * 2) Initially when we start tracking aux, the program 1130 * is not JITed yet and also does not have a kallsyms 1131 * entry. We skip these as poke->tailcall_target_stable 1132 * is not active yet. The JIT will do the final fixup 1133 * before setting it stable. The various 1134 * poke->tailcall_target_stable are successively 1135 * activated, so tail call updates can arrive from here 1136 * while JIT is still finishing its final fixup for 1137 * non-activated poke entries. 1138 * 3) Also programs reaching refcount of zero while patching 1139 * is in progress is okay since we're protected under 1140 * poke_mutex and untrack the programs before the JIT 1141 * buffer is freed. 1142 */ 1143 if (!READ_ONCE(poke->tailcall_target_stable)) 1144 continue; 1145 if (poke->reason != BPF_POKE_REASON_TAIL_CALL) 1146 continue; 1147 if (poke->tail_call.map != map || 1148 poke->tail_call.key != key) 1149 continue; 1150 1151 bpf_arch_poke_desc_update(poke, new, old); 1152 } 1153 } 1154 } 1155 1156 static void prog_array_map_clear_deferred(struct work_struct *work) 1157 { 1158 struct bpf_map *map = container_of(work, struct bpf_array_aux, 1159 work)->map; 1160 bpf_fd_array_map_clear(map, true); 1161 bpf_map_put(map); 1162 } 1163 1164 static void prog_array_map_clear(struct bpf_map *map) 1165 { 1166 struct bpf_array_aux *aux = container_of(map, struct bpf_array, 1167 map)->aux; 1168 bpf_map_inc(map); 1169 schedule_work(&aux->work); 1170 } 1171 1172 static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr) 1173 { 1174 struct bpf_array_aux *aux; 1175 struct bpf_map *map; 1176 1177 aux = kzalloc_obj(*aux, GFP_KERNEL_ACCOUNT); 1178 if (!aux) 1179 return ERR_PTR(-ENOMEM); 1180 1181 INIT_WORK(&aux->work, prog_array_map_clear_deferred); 1182 INIT_LIST_HEAD(&aux->poke_progs); 1183 mutex_init(&aux->poke_mutex); 1184 1185 map = array_map_alloc(attr); 1186 if (IS_ERR(map)) { 1187 kfree(aux); 1188 return map; 1189 } 1190 1191 container_of(map, struct bpf_array, map)->aux = aux; 1192 aux->map = map; 1193 1194 return map; 1195 } 1196 1197 static void prog_array_map_free(struct bpf_map *map) 1198 { 1199 struct prog_poke_elem *elem, *tmp; 1200 struct bpf_array_aux *aux; 1201 1202 aux = container_of(map, struct bpf_array, map)->aux; 1203 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) { 1204 list_del_init(&elem->list); 1205 kfree(elem); 1206 } 1207 kfree(aux); 1208 fd_array_map_free(map); 1209 } 1210 1211 /* prog_array->aux->{type,jited} is a runtime binding. 1212 * Doing static check alone in the verifier is not enough. 1213 * Thus, prog_array_map cannot be used as an inner_map 1214 * and map_meta_equal is not implemented. 1215 */ 1216 const struct bpf_map_ops prog_array_map_ops = { 1217 .map_alloc_check = fd_array_map_alloc_check, 1218 .map_alloc = prog_array_map_alloc, 1219 .map_free = prog_array_map_free, 1220 .map_poke_track = prog_array_map_poke_track, 1221 .map_poke_untrack = prog_array_map_poke_untrack, 1222 .map_poke_run = prog_array_map_poke_run, 1223 .map_get_next_key = bpf_array_get_next_key, 1224 .map_lookup_elem = fd_array_map_lookup_elem, 1225 .map_delete_elem = fd_array_map_delete_elem, 1226 .map_fd_get_ptr = prog_fd_array_get_ptr, 1227 .map_fd_put_ptr = prog_fd_array_put_ptr, 1228 .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, 1229 .map_release_uref = prog_array_map_clear, 1230 .map_seq_show_elem = prog_array_map_seq_show_elem, 1231 .map_mem_usage = array_map_mem_usage, 1232 .map_btf_id = &array_map_btf_ids[0], 1233 }; 1234 1235 static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, 1236 struct file *map_file) 1237 { 1238 struct bpf_event_entry *ee; 1239 1240 ee = kzalloc_obj(*ee); 1241 if (ee) { 1242 ee->event = perf_file->private_data; 1243 ee->perf_file = perf_file; 1244 ee->map_file = map_file; 1245 } 1246 1247 return ee; 1248 } 1249 1250 static void __bpf_event_entry_free(struct rcu_head *rcu) 1251 { 1252 struct bpf_event_entry *ee; 1253 1254 ee = container_of(rcu, struct bpf_event_entry, rcu); 1255 fput(ee->perf_file); 1256 kfree(ee); 1257 } 1258 1259 static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee) 1260 { 1261 call_rcu(&ee->rcu, __bpf_event_entry_free); 1262 } 1263 1264 static void *perf_event_fd_array_get_ptr(struct bpf_map *map, 1265 struct file *map_file, int fd) 1266 { 1267 struct bpf_event_entry *ee; 1268 struct perf_event *event; 1269 struct file *perf_file; 1270 u64 value; 1271 1272 perf_file = perf_event_get(fd); 1273 if (IS_ERR(perf_file)) 1274 return perf_file; 1275 1276 ee = ERR_PTR(-EOPNOTSUPP); 1277 event = perf_file->private_data; 1278 if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP) 1279 goto err_out; 1280 1281 ee = bpf_event_entry_gen(perf_file, map_file); 1282 if (ee) 1283 return ee; 1284 ee = ERR_PTR(-ENOMEM); 1285 err_out: 1286 fput(perf_file); 1287 return ee; 1288 } 1289 1290 static void perf_event_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) 1291 { 1292 /* bpf_perf_event is freed after one RCU grace period */ 1293 bpf_event_entry_free_rcu(ptr); 1294 } 1295 1296 static void perf_event_fd_array_release(struct bpf_map *map, 1297 struct file *map_file) 1298 { 1299 struct bpf_array *array = container_of(map, struct bpf_array, map); 1300 struct bpf_event_entry *ee; 1301 int i; 1302 1303 if (map->map_flags & BPF_F_PRESERVE_ELEMS) 1304 return; 1305 1306 rcu_read_lock(); 1307 for (i = 0; i < array->map.max_entries; i++) { 1308 ee = READ_ONCE(array->ptrs[i]); 1309 if (ee && ee->map_file == map_file) 1310 __fd_array_map_delete_elem(map, &i, true); 1311 } 1312 rcu_read_unlock(); 1313 } 1314 1315 static void perf_event_fd_array_map_free(struct bpf_map *map) 1316 { 1317 if (map->map_flags & BPF_F_PRESERVE_ELEMS) 1318 bpf_fd_array_map_clear(map, false); 1319 fd_array_map_free(map); 1320 } 1321 1322 const struct bpf_map_ops perf_event_array_map_ops = { 1323 .map_meta_equal = bpf_map_meta_equal, 1324 .map_alloc_check = fd_array_map_alloc_check, 1325 .map_alloc = array_map_alloc, 1326 .map_free = perf_event_fd_array_map_free, 1327 .map_get_next_key = bpf_array_get_next_key, 1328 .map_lookup_elem = fd_array_map_lookup_elem, 1329 .map_delete_elem = fd_array_map_delete_elem, 1330 .map_fd_get_ptr = perf_event_fd_array_get_ptr, 1331 .map_fd_put_ptr = perf_event_fd_array_put_ptr, 1332 .map_release = perf_event_fd_array_release, 1333 .map_check_btf = map_check_no_btf, 1334 .map_mem_usage = array_map_mem_usage, 1335 .map_btf_id = &array_map_btf_ids[0], 1336 }; 1337 1338 #ifdef CONFIG_CGROUPS 1339 static void *cgroup_fd_array_get_ptr(struct bpf_map *map, 1340 struct file *map_file /* not used */, 1341 int fd) 1342 { 1343 return cgroup_get_from_fd(fd); 1344 } 1345 1346 static void cgroup_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) 1347 { 1348 /* cgroup_put free cgrp after a rcu grace period */ 1349 cgroup_put(ptr); 1350 } 1351 1352 static void cgroup_fd_array_free(struct bpf_map *map) 1353 { 1354 bpf_fd_array_map_clear(map, false); 1355 fd_array_map_free(map); 1356 } 1357 1358 const struct bpf_map_ops cgroup_array_map_ops = { 1359 .map_meta_equal = bpf_map_meta_equal, 1360 .map_alloc_check = fd_array_map_alloc_check, 1361 .map_alloc = array_map_alloc, 1362 .map_free = cgroup_fd_array_free, 1363 .map_get_next_key = bpf_array_get_next_key, 1364 .map_lookup_elem = fd_array_map_lookup_elem, 1365 .map_delete_elem = fd_array_map_delete_elem, 1366 .map_fd_get_ptr = cgroup_fd_array_get_ptr, 1367 .map_fd_put_ptr = cgroup_fd_array_put_ptr, 1368 .map_check_btf = map_check_no_btf, 1369 .map_mem_usage = array_map_mem_usage, 1370 .map_btf_id = &array_map_btf_ids[0], 1371 }; 1372 #endif 1373 1374 static struct bpf_map *array_of_map_alloc(union bpf_attr *attr) 1375 { 1376 struct bpf_map *map, *inner_map_meta; 1377 1378 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd); 1379 if (IS_ERR(inner_map_meta)) 1380 return inner_map_meta; 1381 1382 map = array_map_alloc(attr); 1383 if (IS_ERR(map)) { 1384 bpf_map_meta_free(inner_map_meta); 1385 return map; 1386 } 1387 1388 map->inner_map_meta = inner_map_meta; 1389 1390 return map; 1391 } 1392 1393 static void array_of_map_free(struct bpf_map *map) 1394 { 1395 /* map->inner_map_meta is only accessed by syscall which 1396 * is protected by fdget/fdput. 1397 */ 1398 bpf_map_meta_free(map->inner_map_meta); 1399 bpf_fd_array_map_clear(map, false); 1400 fd_array_map_free(map); 1401 } 1402 1403 static void *array_of_map_lookup_elem(struct bpf_map *map, void *key) 1404 { 1405 struct bpf_map **inner_map = array_map_lookup_elem(map, key); 1406 1407 if (!inner_map) 1408 return NULL; 1409 1410 return READ_ONCE(*inner_map); 1411 } 1412 1413 static int array_of_map_gen_lookup(struct bpf_map *map, 1414 struct bpf_insn *insn_buf) 1415 { 1416 struct bpf_array *array = container_of(map, struct bpf_array, map); 1417 u32 elem_size = array->elem_size; 1418 struct bpf_insn *insn = insn_buf; 1419 const int ret = BPF_REG_0; 1420 const int map_ptr = BPF_REG_1; 1421 const int index = BPF_REG_2; 1422 1423 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); 1424 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); 1425 if (!map->bypass_spec_v1) { 1426 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6); 1427 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); 1428 } else { 1429 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5); 1430 } 1431 if (is_power_of_2(elem_size)) 1432 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); 1433 else 1434 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); 1435 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); 1436 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0); 1437 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1); 1438 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); 1439 *insn++ = BPF_MOV64_IMM(ret, 0); 1440 1441 return insn - insn_buf; 1442 } 1443 1444 const struct bpf_map_ops array_of_maps_map_ops = { 1445 .map_alloc_check = fd_array_map_alloc_check, 1446 .map_alloc = array_of_map_alloc, 1447 .map_free = array_of_map_free, 1448 .map_get_next_key = bpf_array_get_next_key, 1449 .map_lookup_elem = array_of_map_lookup_elem, 1450 .map_delete_elem = fd_array_map_delete_elem, 1451 .map_fd_get_ptr = bpf_map_fd_get_ptr, 1452 .map_fd_put_ptr = bpf_map_fd_put_ptr, 1453 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, 1454 .map_gen_lookup = array_of_map_gen_lookup, 1455 .map_lookup_batch = generic_map_lookup_batch, 1456 .map_update_batch = generic_map_update_batch, 1457 .map_check_btf = map_check_no_btf, 1458 .map_mem_usage = array_map_mem_usage, 1459 .map_btf_id = &array_map_btf_ids[0], 1460 }; 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