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, u32 hash_buf_size, 179 void *hash_buf) 180 { 181 struct bpf_array *array = container_of(map, struct bpf_array, map); 182 183 sha256(array->value, (u64)array->elem_size * array->map.max_entries, 184 hash_buf); 185 memcpy(array->map.sha, hash_buf, sizeof(array->map.sha)); 186 return 0; 187 } 188 189 static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm, 190 u32 off) 191 { 192 struct bpf_array *array = container_of(map, struct bpf_array, map); 193 194 if (map->max_entries != 1) 195 return -ENOTSUPP; 196 if (off >= map->value_size) 197 return -EINVAL; 198 199 *imm = (unsigned long)array->value; 200 return 0; 201 } 202 203 static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm, 204 u32 *off) 205 { 206 struct bpf_array *array = container_of(map, struct bpf_array, map); 207 u64 base = (unsigned long)array->value; 208 u64 range = array->elem_size; 209 210 if (map->max_entries != 1) 211 return -ENOTSUPP; 212 if (imm < base || imm >= base + range) 213 return -ENOENT; 214 215 *off = imm - base; 216 return 0; 217 } 218 219 /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */ 220 static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) 221 { 222 struct bpf_array *array = container_of(map, struct bpf_array, map); 223 struct bpf_insn *insn = insn_buf; 224 u32 elem_size = array->elem_size; 225 const int ret = BPF_REG_0; 226 const int map_ptr = BPF_REG_1; 227 const int index = BPF_REG_2; 228 229 if (map->map_flags & BPF_F_INNER_MAP) 230 return -EOPNOTSUPP; 231 232 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); 233 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); 234 if (!map->bypass_spec_v1) { 235 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4); 236 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); 237 } else { 238 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3); 239 } 240 241 if (is_power_of_2(elem_size)) { 242 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); 243 } else { 244 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); 245 } 246 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); 247 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); 248 *insn++ = BPF_MOV64_IMM(ret, 0); 249 return insn - insn_buf; 250 } 251 252 /* Called from eBPF program */ 253 static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key) 254 { 255 struct bpf_array *array = container_of(map, struct bpf_array, map); 256 u32 index = *(u32 *)key; 257 258 if (unlikely(index >= array->map.max_entries)) 259 return NULL; 260 261 return this_cpu_ptr(array->pptrs[index & array->index_mask]); 262 } 263 264 /* emit BPF instructions equivalent to C code of percpu_array_map_lookup_elem() */ 265 static int percpu_array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) 266 { 267 struct bpf_array *array = container_of(map, struct bpf_array, map); 268 struct bpf_insn *insn = insn_buf; 269 270 if (!bpf_jit_supports_percpu_insn()) 271 return -EOPNOTSUPP; 272 273 if (map->map_flags & BPF_F_INNER_MAP) 274 return -EOPNOTSUPP; 275 276 BUILD_BUG_ON(offsetof(struct bpf_array, map) != 0); 277 *insn++ = BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, offsetof(struct bpf_array, pptrs)); 278 279 *insn++ = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0); 280 if (!map->bypass_spec_v1) { 281 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 6); 282 *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_0, array->index_mask); 283 } else { 284 *insn++ = BPF_JMP_IMM(BPF_JGE, BPF_REG_0, map->max_entries, 5); 285 } 286 287 *insn++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_0, 3); 288 *insn++ = BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1); 289 *insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0); 290 *insn++ = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0); 291 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); 292 *insn++ = BPF_MOV64_IMM(BPF_REG_0, 0); 293 return insn - insn_buf; 294 } 295 296 static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu) 297 { 298 struct bpf_array *array = container_of(map, struct bpf_array, map); 299 u32 index = *(u32 *)key; 300 301 if (cpu >= nr_cpu_ids) 302 return NULL; 303 304 if (unlikely(index >= array->map.max_entries)) 305 return NULL; 306 307 return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu); 308 } 309 310 int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, u64 map_flags) 311 { 312 struct bpf_array *array = container_of(map, struct bpf_array, map); 313 u32 index = *(u32 *)key; 314 void __percpu *pptr; 315 int cpu, off = 0; 316 u32 size; 317 318 if (unlikely(index >= array->map.max_entries)) 319 return -ENOENT; 320 321 /* per_cpu areas are zero-filled and bpf programs can only 322 * access 'value_size' of them, so copying rounded areas 323 * will not leak any kernel data 324 */ 325 size = array->elem_size; 326 rcu_read_lock(); 327 pptr = array->pptrs[index & array->index_mask]; 328 if (map_flags & BPF_F_CPU) { 329 cpu = map_flags >> 32; 330 copy_map_value(map, value, per_cpu_ptr(pptr, cpu)); 331 check_and_init_map_value(map, value); 332 goto unlock; 333 } 334 for_each_possible_cpu(cpu) { 335 copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu)); 336 check_and_init_map_value(map, value + off); 337 off += size; 338 } 339 unlock: 340 rcu_read_unlock(); 341 return 0; 342 } 343 344 /* Called from syscall */ 345 int bpf_array_get_next_key(struct bpf_map *map, void *key, void *next_key) 346 { 347 u32 index = key ? *(u32 *)key : U32_MAX; 348 u32 *next = (u32 *)next_key; 349 350 if (index >= map->max_entries) { 351 *next = 0; 352 return 0; 353 } 354 355 if (index == map->max_entries - 1) 356 return -ENOENT; 357 358 *next = index + 1; 359 return 0; 360 } 361 362 /* Called from syscall or from eBPF program */ 363 static long array_map_update_elem(struct bpf_map *map, void *key, void *value, 364 u64 map_flags) 365 { 366 struct bpf_array *array = container_of(map, struct bpf_array, map); 367 u32 index = *(u32 *)key; 368 char *val; 369 370 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST)) 371 /* unknown flags */ 372 return -EINVAL; 373 374 if (unlikely(index >= array->map.max_entries)) 375 /* all elements were pre-allocated, cannot insert a new one */ 376 return -E2BIG; 377 378 if (unlikely(map_flags & BPF_NOEXIST)) 379 /* all elements already exist */ 380 return -EEXIST; 381 382 if (unlikely((map_flags & BPF_F_LOCK) && 383 !btf_record_has_field(map->record, BPF_SPIN_LOCK))) 384 return -EINVAL; 385 386 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 387 val = this_cpu_ptr(array->pptrs[index & array->index_mask]); 388 copy_map_value(map, val, value); 389 bpf_obj_free_fields(array->map.record, val); 390 } else { 391 val = array->value + 392 (u64)array->elem_size * (index & array->index_mask); 393 if (map_flags & BPF_F_LOCK) 394 copy_map_value_locked(map, val, value, false); 395 else 396 copy_map_value(map, val, value); 397 bpf_obj_free_fields(array->map.record, val); 398 } 399 return 0; 400 } 401 402 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 403 u64 map_flags) 404 { 405 struct bpf_array *array = container_of(map, struct bpf_array, map); 406 u32 index = *(u32 *)key; 407 void __percpu *pptr; 408 void *ptr, *val; 409 u32 size; 410 int cpu; 411 412 if (unlikely((map_flags & BPF_F_LOCK) || (u32)map_flags > BPF_F_ALL_CPUS)) 413 /* unknown flags */ 414 return -EINVAL; 415 416 if (unlikely(index >= array->map.max_entries)) 417 /* all elements were pre-allocated, cannot insert a new one */ 418 return -E2BIG; 419 420 if (unlikely(map_flags == BPF_NOEXIST)) 421 /* all elements already exist */ 422 return -EEXIST; 423 424 /* the user space will provide round_up(value_size, 8) bytes that 425 * will be copied into per-cpu area. bpf programs can only access 426 * value_size of it. During lookup the same extra bytes will be 427 * returned or zeros which were zero-filled by percpu_alloc, 428 * so no kernel data leaks possible 429 */ 430 size = array->elem_size; 431 rcu_read_lock(); 432 pptr = array->pptrs[index & array->index_mask]; 433 if (map_flags & BPF_F_CPU) { 434 cpu = map_flags >> 32; 435 ptr = per_cpu_ptr(pptr, cpu); 436 copy_map_value(map, ptr, value); 437 bpf_obj_free_fields(array->map.record, ptr); 438 goto unlock; 439 } 440 for_each_possible_cpu(cpu) { 441 ptr = per_cpu_ptr(pptr, cpu); 442 val = (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu; 443 copy_map_value(map, ptr, val); 444 bpf_obj_free_fields(array->map.record, ptr); 445 } 446 unlock: 447 rcu_read_unlock(); 448 return 0; 449 } 450 451 /* Called from syscall or from eBPF program */ 452 static long array_map_delete_elem(struct bpf_map *map, void *key) 453 { 454 return -EINVAL; 455 } 456 457 static void *array_map_vmalloc_addr(struct bpf_array *array) 458 { 459 return (void *)round_down((unsigned long)array, PAGE_SIZE); 460 } 461 462 static void array_map_free_internal_structs(struct bpf_map *map) 463 { 464 struct bpf_array *array = container_of(map, struct bpf_array, map); 465 int i; 466 467 /* We only free internal structs on uref dropping to zero */ 468 if (!bpf_map_has_internal_structs(map)) 469 return; 470 471 for (i = 0; i < array->map.max_entries; i++) 472 bpf_map_free_internal_structs(map, array_map_elem_ptr(array, i)); 473 } 474 475 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ 476 static void array_map_free(struct bpf_map *map) 477 { 478 struct bpf_array *array = container_of(map, struct bpf_array, map); 479 int i; 480 481 if (!IS_ERR_OR_NULL(map->record)) { 482 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 483 for (i = 0; i < array->map.max_entries; i++) { 484 void __percpu *pptr = array->pptrs[i & array->index_mask]; 485 int cpu; 486 487 for_each_possible_cpu(cpu) { 488 bpf_obj_free_fields(map->record, per_cpu_ptr(pptr, cpu)); 489 cond_resched(); 490 } 491 } 492 } else { 493 for (i = 0; i < array->map.max_entries; i++) 494 bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i)); 495 } 496 } 497 498 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) 499 bpf_array_free_percpu(array); 500 501 if (array->map.map_flags & BPF_F_MMAPABLE) 502 bpf_map_area_free(array_map_vmalloc_addr(array)); 503 else 504 bpf_map_area_free(array); 505 } 506 507 static void array_map_seq_show_elem(struct bpf_map *map, void *key, 508 struct seq_file *m) 509 { 510 void *value; 511 512 rcu_read_lock(); 513 514 value = array_map_lookup_elem(map, key); 515 if (!value) { 516 rcu_read_unlock(); 517 return; 518 } 519 520 if (map->btf_key_type_id) 521 seq_printf(m, "%u: ", *(u32 *)key); 522 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m); 523 seq_putc(m, '\n'); 524 525 rcu_read_unlock(); 526 } 527 528 static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key, 529 struct seq_file *m) 530 { 531 struct bpf_array *array = container_of(map, struct bpf_array, map); 532 u32 index = *(u32 *)key; 533 void __percpu *pptr; 534 int cpu; 535 536 rcu_read_lock(); 537 538 seq_printf(m, "%u: {\n", *(u32 *)key); 539 pptr = array->pptrs[index & array->index_mask]; 540 for_each_possible_cpu(cpu) { 541 seq_printf(m, "\tcpu%d: ", cpu); 542 btf_type_seq_show(map->btf, map->btf_value_type_id, 543 per_cpu_ptr(pptr, cpu), m); 544 seq_putc(m, '\n'); 545 } 546 seq_puts(m, "}\n"); 547 548 rcu_read_unlock(); 549 } 550 551 static int array_map_check_btf(const struct bpf_map *map, 552 const struct btf *btf, 553 const struct btf_type *key_type, 554 const struct btf_type *value_type) 555 { 556 /* One exception for keyless BTF: .bss/.data/.rodata map */ 557 if (btf_type_is_void(key_type)) { 558 if (map->map_type != BPF_MAP_TYPE_ARRAY || 559 map->max_entries != 1) 560 return -EINVAL; 561 562 if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC) 563 return -EINVAL; 564 565 return 0; 566 } 567 568 /* 569 * Bpf array can only take a u32 key. This check makes sure 570 * that the btf matches the attr used during map_create. 571 */ 572 if (!btf_type_is_i32(key_type)) 573 return -EINVAL; 574 575 return 0; 576 } 577 578 static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma) 579 { 580 struct bpf_array *array = container_of(map, struct bpf_array, map); 581 pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT; 582 583 if (!(map->map_flags & BPF_F_MMAPABLE)) 584 return -EINVAL; 585 586 if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) > 587 PAGE_ALIGN((u64)array->map.max_entries * array->elem_size)) 588 return -EINVAL; 589 590 return remap_vmalloc_range(vma, array_map_vmalloc_addr(array), 591 vma->vm_pgoff + pgoff); 592 } 593 594 static bool array_map_meta_equal(const struct bpf_map *meta0, 595 const struct bpf_map *meta1) 596 { 597 if (!bpf_map_meta_equal(meta0, meta1)) 598 return false; 599 return meta0->map_flags & BPF_F_INNER_MAP ? true : 600 meta0->max_entries == meta1->max_entries; 601 } 602 603 struct bpf_iter_seq_array_map_info { 604 struct bpf_map *map; 605 void *percpu_value_buf; 606 u32 index; 607 }; 608 609 static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos) 610 { 611 struct bpf_iter_seq_array_map_info *info = seq->private; 612 struct bpf_map *map = info->map; 613 struct bpf_array *array; 614 u32 index; 615 616 if (info->index >= map->max_entries) 617 return NULL; 618 619 if (*pos == 0) 620 ++*pos; 621 array = container_of(map, struct bpf_array, map); 622 index = info->index & array->index_mask; 623 if (info->percpu_value_buf) 624 return (void *)(uintptr_t)array->pptrs[index]; 625 return array_map_elem_ptr(array, index); 626 } 627 628 static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) 629 { 630 struct bpf_iter_seq_array_map_info *info = seq->private; 631 struct bpf_map *map = info->map; 632 struct bpf_array *array; 633 u32 index; 634 635 ++*pos; 636 ++info->index; 637 if (info->index >= map->max_entries) 638 return NULL; 639 640 array = container_of(map, struct bpf_array, map); 641 index = info->index & array->index_mask; 642 if (info->percpu_value_buf) 643 return (void *)(uintptr_t)array->pptrs[index]; 644 return array_map_elem_ptr(array, index); 645 } 646 647 static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) 648 { 649 struct bpf_iter_seq_array_map_info *info = seq->private; 650 struct bpf_iter__bpf_map_elem ctx = {}; 651 struct bpf_map *map = info->map; 652 struct bpf_array *array = container_of(map, struct bpf_array, map); 653 struct bpf_iter_meta meta; 654 struct bpf_prog *prog; 655 int off = 0, cpu = 0; 656 void __percpu *pptr; 657 u32 size; 658 659 meta.seq = seq; 660 prog = bpf_iter_get_info(&meta, v == NULL); 661 if (!prog) 662 return 0; 663 664 ctx.meta = &meta; 665 ctx.map = info->map; 666 if (v) { 667 ctx.key = &info->index; 668 669 if (!info->percpu_value_buf) { 670 ctx.value = v; 671 } else { 672 pptr = (void __percpu *)(uintptr_t)v; 673 size = array->elem_size; 674 for_each_possible_cpu(cpu) { 675 copy_map_value_long(map, info->percpu_value_buf + off, 676 per_cpu_ptr(pptr, cpu)); 677 check_and_init_map_value(map, info->percpu_value_buf + off); 678 off += size; 679 } 680 ctx.value = info->percpu_value_buf; 681 } 682 } 683 684 return bpf_iter_run_prog(prog, &ctx); 685 } 686 687 static int bpf_array_map_seq_show(struct seq_file *seq, void *v) 688 { 689 return __bpf_array_map_seq_show(seq, v); 690 } 691 692 static void bpf_array_map_seq_stop(struct seq_file *seq, void *v) 693 { 694 if (!v) 695 (void)__bpf_array_map_seq_show(seq, NULL); 696 } 697 698 static int bpf_iter_init_array_map(void *priv_data, 699 struct bpf_iter_aux_info *aux) 700 { 701 struct bpf_iter_seq_array_map_info *seq_info = priv_data; 702 struct bpf_map *map = aux->map; 703 struct bpf_array *array = container_of(map, struct bpf_array, map); 704 void *value_buf; 705 u32 buf_size; 706 707 if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 708 buf_size = array->elem_size * num_possible_cpus(); 709 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN); 710 if (!value_buf) 711 return -ENOMEM; 712 713 seq_info->percpu_value_buf = value_buf; 714 } 715 716 /* bpf_iter_attach_map() acquires a map uref, and the uref may be 717 * released before or in the middle of iterating map elements, so 718 * acquire an extra map uref for iterator. 719 */ 720 bpf_map_inc_with_uref(map); 721 seq_info->map = map; 722 return 0; 723 } 724 725 static void bpf_iter_fini_array_map(void *priv_data) 726 { 727 struct bpf_iter_seq_array_map_info *seq_info = priv_data; 728 729 bpf_map_put_with_uref(seq_info->map); 730 kfree(seq_info->percpu_value_buf); 731 } 732 733 static const struct seq_operations bpf_array_map_seq_ops = { 734 .start = bpf_array_map_seq_start, 735 .next = bpf_array_map_seq_next, 736 .stop = bpf_array_map_seq_stop, 737 .show = bpf_array_map_seq_show, 738 }; 739 740 static const struct bpf_iter_seq_info iter_seq_info = { 741 .seq_ops = &bpf_array_map_seq_ops, 742 .init_seq_private = bpf_iter_init_array_map, 743 .fini_seq_private = bpf_iter_fini_array_map, 744 .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info), 745 }; 746 747 static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn, 748 void *callback_ctx, u64 flags) 749 { 750 u32 i, key, num_elems = 0; 751 struct bpf_array *array; 752 bool is_percpu; 753 u64 ret = 0; 754 void *val; 755 756 cant_migrate(); 757 758 if (flags != 0) 759 return -EINVAL; 760 761 is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 762 array = container_of(map, struct bpf_array, map); 763 for (i = 0; i < map->max_entries; i++) { 764 if (is_percpu) 765 val = this_cpu_ptr(array->pptrs[i]); 766 else 767 val = array_map_elem_ptr(array, i); 768 num_elems++; 769 key = i; 770 ret = callback_fn((u64)(long)map, (u64)(long)&key, 771 (u64)(long)val, (u64)(long)callback_ctx, 0); 772 /* return value: 0 - continue, 1 - stop and return */ 773 if (ret) 774 break; 775 } 776 777 return num_elems; 778 } 779 780 static u64 array_map_mem_usage(const struct bpf_map *map) 781 { 782 struct bpf_array *array = container_of(map, struct bpf_array, map); 783 bool percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 784 u32 elem_size = array->elem_size; 785 u64 entries = map->max_entries; 786 u64 usage = sizeof(*array); 787 788 if (percpu) { 789 usage += entries * sizeof(void *); 790 usage += entries * elem_size * num_possible_cpus(); 791 } else { 792 if (map->map_flags & BPF_F_MMAPABLE) { 793 usage = PAGE_ALIGN(usage); 794 usage += PAGE_ALIGN(entries * elem_size); 795 } else { 796 usage += entries * elem_size; 797 } 798 } 799 return usage; 800 } 801 802 BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array) 803 const struct bpf_map_ops array_map_ops = { 804 .map_meta_equal = array_map_meta_equal, 805 .map_alloc_check = array_map_alloc_check, 806 .map_alloc = array_map_alloc, 807 .map_free = array_map_free, 808 .map_get_next_key = bpf_array_get_next_key, 809 .map_release_uref = array_map_free_internal_structs, 810 .map_lookup_elem = array_map_lookup_elem, 811 .map_update_elem = array_map_update_elem, 812 .map_delete_elem = array_map_delete_elem, 813 .map_gen_lookup = array_map_gen_lookup, 814 .map_direct_value_addr = array_map_direct_value_addr, 815 .map_direct_value_meta = array_map_direct_value_meta, 816 .map_mmap = array_map_mmap, 817 .map_seq_show_elem = array_map_seq_show_elem, 818 .map_check_btf = array_map_check_btf, 819 .map_lookup_batch = generic_map_lookup_batch, 820 .map_update_batch = generic_map_update_batch, 821 .map_set_for_each_callback_args = map_set_for_each_callback_args, 822 .map_for_each_callback = bpf_for_each_array_elem, 823 .map_mem_usage = array_map_mem_usage, 824 .map_btf_id = &array_map_btf_ids[0], 825 .iter_seq_info = &iter_seq_info, 826 .map_get_hash = &array_map_get_hash, 827 }; 828 829 const struct bpf_map_ops percpu_array_map_ops = { 830 .map_meta_equal = bpf_map_meta_equal, 831 .map_alloc_check = array_map_alloc_check, 832 .map_alloc = array_map_alloc, 833 .map_free = array_map_free, 834 .map_get_next_key = bpf_array_get_next_key, 835 .map_lookup_elem = percpu_array_map_lookup_elem, 836 .map_gen_lookup = percpu_array_map_gen_lookup, 837 .map_update_elem = array_map_update_elem, 838 .map_delete_elem = array_map_delete_elem, 839 .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem, 840 .map_seq_show_elem = percpu_array_map_seq_show_elem, 841 .map_check_btf = array_map_check_btf, 842 .map_lookup_batch = generic_map_lookup_batch, 843 .map_update_batch = generic_map_update_batch, 844 .map_set_for_each_callback_args = map_set_for_each_callback_args, 845 .map_for_each_callback = bpf_for_each_array_elem, 846 .map_mem_usage = array_map_mem_usage, 847 .map_btf_id = &array_map_btf_ids[0], 848 .iter_seq_info = &iter_seq_info, 849 }; 850 851 static int fd_array_map_alloc_check(union bpf_attr *attr) 852 { 853 /* only file descriptors can be stored in this type of map */ 854 if (attr->value_size != sizeof(u32)) 855 return -EINVAL; 856 /* Program read-only/write-only not supported for special maps yet. */ 857 if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) 858 return -EINVAL; 859 return array_map_alloc_check(attr); 860 } 861 862 static void fd_array_map_free(struct bpf_map *map) 863 { 864 struct bpf_array *array = container_of(map, struct bpf_array, map); 865 int i; 866 867 /* make sure it's empty */ 868 for (i = 0; i < array->map.max_entries; i++) 869 BUG_ON(array->ptrs[i] != NULL); 870 871 bpf_map_area_free(array); 872 } 873 874 static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) 875 { 876 return ERR_PTR(-EOPNOTSUPP); 877 } 878 879 /* only called from syscall */ 880 int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) 881 { 882 void **elem, *ptr; 883 int ret = 0; 884 885 if (!map->ops->map_fd_sys_lookup_elem) 886 return -ENOTSUPP; 887 888 rcu_read_lock(); 889 elem = array_map_lookup_elem(map, key); 890 if (elem && (ptr = READ_ONCE(*elem))) 891 *value = map->ops->map_fd_sys_lookup_elem(ptr); 892 else 893 ret = -ENOENT; 894 rcu_read_unlock(); 895 896 return ret; 897 } 898 899 /* only called from syscall */ 900 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, 901 void *key, void *value, u64 map_flags) 902 { 903 struct bpf_array *array = container_of(map, struct bpf_array, map); 904 void *new_ptr, *old_ptr; 905 u32 index = *(u32 *)key, ufd; 906 907 if (map_flags != BPF_ANY) 908 return -EINVAL; 909 910 if (index >= array->map.max_entries) 911 return -E2BIG; 912 913 ufd = *(u32 *)value; 914 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd); 915 if (IS_ERR(new_ptr)) 916 return PTR_ERR(new_ptr); 917 918 if (map->ops->map_poke_run) { 919 mutex_lock(&array->aux->poke_mutex); 920 old_ptr = xchg(array->ptrs + index, new_ptr); 921 map->ops->map_poke_run(map, index, old_ptr, new_ptr); 922 mutex_unlock(&array->aux->poke_mutex); 923 } else { 924 old_ptr = xchg(array->ptrs + index, new_ptr); 925 } 926 927 if (old_ptr) 928 map->ops->map_fd_put_ptr(map, old_ptr, true); 929 return 0; 930 } 931 932 static long __fd_array_map_delete_elem(struct bpf_map *map, void *key, bool need_defer) 933 { 934 struct bpf_array *array = container_of(map, struct bpf_array, map); 935 void *old_ptr; 936 u32 index = *(u32 *)key; 937 938 if (index >= array->map.max_entries) 939 return -E2BIG; 940 941 if (map->ops->map_poke_run) { 942 mutex_lock(&array->aux->poke_mutex); 943 old_ptr = xchg(array->ptrs + index, NULL); 944 map->ops->map_poke_run(map, index, old_ptr, NULL); 945 mutex_unlock(&array->aux->poke_mutex); 946 } else { 947 old_ptr = xchg(array->ptrs + index, NULL); 948 } 949 950 if (old_ptr) { 951 map->ops->map_fd_put_ptr(map, old_ptr, need_defer); 952 return 0; 953 } else { 954 return -ENOENT; 955 } 956 } 957 958 static long fd_array_map_delete_elem(struct bpf_map *map, void *key) 959 { 960 return __fd_array_map_delete_elem(map, key, true); 961 } 962 963 static void *prog_fd_array_get_ptr(struct bpf_map *map, 964 struct file *map_file, int fd) 965 { 966 struct bpf_prog *prog = bpf_prog_get(fd); 967 bool is_extended; 968 969 if (IS_ERR(prog)) 970 return prog; 971 972 if (prog->type == BPF_PROG_TYPE_EXT || 973 !bpf_prog_map_compatible(map, prog)) { 974 bpf_prog_put(prog); 975 return ERR_PTR(-EINVAL); 976 } 977 978 mutex_lock(&prog->aux->ext_mutex); 979 is_extended = prog->aux->is_extended; 980 if (!is_extended) 981 prog->aux->prog_array_member_cnt++; 982 mutex_unlock(&prog->aux->ext_mutex); 983 if (is_extended) { 984 /* Extended prog can not be tail callee. It's to prevent a 985 * potential infinite loop like: 986 * tail callee prog entry -> tail callee prog subprog -> 987 * freplace prog entry --tailcall-> tail callee prog entry. 988 */ 989 bpf_prog_put(prog); 990 return ERR_PTR(-EBUSY); 991 } 992 993 return prog; 994 } 995 996 static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) 997 { 998 struct bpf_prog *prog = ptr; 999 1000 mutex_lock(&prog->aux->ext_mutex); 1001 prog->aux->prog_array_member_cnt--; 1002 mutex_unlock(&prog->aux->ext_mutex); 1003 /* bpf_prog is freed after one RCU or tasks trace grace period */ 1004 bpf_prog_put(prog); 1005 } 1006 1007 static u32 prog_fd_array_sys_lookup_elem(void *ptr) 1008 { 1009 return ((struct bpf_prog *)ptr)->aux->id; 1010 } 1011 1012 /* decrement refcnt of all bpf_progs that are stored in this map */ 1013 static void bpf_fd_array_map_clear(struct bpf_map *map, bool need_defer) 1014 { 1015 struct bpf_array *array = container_of(map, struct bpf_array, map); 1016 int i; 1017 1018 for (i = 0; i < array->map.max_entries; i++) 1019 __fd_array_map_delete_elem(map, &i, need_defer); 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(sizeof(*elem), GFP_KERNEL); 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(sizeof(*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(sizeof(*ee), GFP_KERNEL); 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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