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) 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 for_each_possible_cpu(cpu) { 329 copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu)); 330 check_and_init_map_value(map, value + off); 331 off += size; 332 } 333 rcu_read_unlock(); 334 return 0; 335 } 336 337 /* Called from syscall */ 338 static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key) 339 { 340 struct bpf_array *array = container_of(map, struct bpf_array, map); 341 u32 index = key ? *(u32 *)key : U32_MAX; 342 u32 *next = (u32 *)next_key; 343 344 if (index >= array->map.max_entries) { 345 *next = 0; 346 return 0; 347 } 348 349 if (index == array->map.max_entries - 1) 350 return -ENOENT; 351 352 *next = index + 1; 353 return 0; 354 } 355 356 /* Called from syscall or from eBPF program */ 357 static long array_map_update_elem(struct bpf_map *map, void *key, void *value, 358 u64 map_flags) 359 { 360 struct bpf_array *array = container_of(map, struct bpf_array, map); 361 u32 index = *(u32 *)key; 362 char *val; 363 364 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST)) 365 /* unknown flags */ 366 return -EINVAL; 367 368 if (unlikely(index >= array->map.max_entries)) 369 /* all elements were pre-allocated, cannot insert a new one */ 370 return -E2BIG; 371 372 if (unlikely(map_flags & BPF_NOEXIST)) 373 /* all elements already exist */ 374 return -EEXIST; 375 376 if (unlikely((map_flags & BPF_F_LOCK) && 377 !btf_record_has_field(map->record, BPF_SPIN_LOCK))) 378 return -EINVAL; 379 380 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 381 val = this_cpu_ptr(array->pptrs[index & array->index_mask]); 382 copy_map_value(map, val, value); 383 bpf_obj_free_fields(array->map.record, val); 384 } else { 385 val = array->value + 386 (u64)array->elem_size * (index & array->index_mask); 387 if (map_flags & BPF_F_LOCK) 388 copy_map_value_locked(map, val, value, false); 389 else 390 copy_map_value(map, val, value); 391 bpf_obj_free_fields(array->map.record, val); 392 } 393 return 0; 394 } 395 396 int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, 397 u64 map_flags) 398 { 399 struct bpf_array *array = container_of(map, struct bpf_array, map); 400 u32 index = *(u32 *)key; 401 void __percpu *pptr; 402 int cpu, off = 0; 403 u32 size; 404 405 if (unlikely(map_flags > BPF_EXIST)) 406 /* unknown flags */ 407 return -EINVAL; 408 409 if (unlikely(index >= array->map.max_entries)) 410 /* all elements were pre-allocated, cannot insert a new one */ 411 return -E2BIG; 412 413 if (unlikely(map_flags == BPF_NOEXIST)) 414 /* all elements already exist */ 415 return -EEXIST; 416 417 /* the user space will provide round_up(value_size, 8) bytes that 418 * will be copied into per-cpu area. bpf programs can only access 419 * value_size of it. During lookup the same extra bytes will be 420 * returned or zeros which were zero-filled by percpu_alloc, 421 * so no kernel data leaks possible 422 */ 423 size = array->elem_size; 424 rcu_read_lock(); 425 pptr = array->pptrs[index & array->index_mask]; 426 for_each_possible_cpu(cpu) { 427 copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off); 428 bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu)); 429 off += size; 430 } 431 rcu_read_unlock(); 432 return 0; 433 } 434 435 /* Called from syscall or from eBPF program */ 436 static long array_map_delete_elem(struct bpf_map *map, void *key) 437 { 438 return -EINVAL; 439 } 440 441 static void *array_map_vmalloc_addr(struct bpf_array *array) 442 { 443 return (void *)round_down((unsigned long)array, PAGE_SIZE); 444 } 445 446 static void array_map_free_internal_structs(struct bpf_map *map) 447 { 448 struct bpf_array *array = container_of(map, struct bpf_array, map); 449 int i; 450 451 /* We don't reset or free fields other than timer and workqueue 452 * on uref dropping to zero. 453 */ 454 if (btf_record_has_field(map->record, BPF_TIMER | BPF_WORKQUEUE | BPF_TASK_WORK)) { 455 for (i = 0; i < array->map.max_entries; i++) { 456 if (btf_record_has_field(map->record, BPF_TIMER)) 457 bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i)); 458 if (btf_record_has_field(map->record, BPF_WORKQUEUE)) 459 bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i)); 460 if (btf_record_has_field(map->record, BPF_TASK_WORK)) 461 bpf_obj_free_task_work(map->record, array_map_elem_ptr(array, i)); 462 } 463 } 464 } 465 466 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ 467 static void array_map_free(struct bpf_map *map) 468 { 469 struct bpf_array *array = container_of(map, struct bpf_array, map); 470 int i; 471 472 if (!IS_ERR_OR_NULL(map->record)) { 473 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 474 for (i = 0; i < array->map.max_entries; i++) { 475 void __percpu *pptr = array->pptrs[i & array->index_mask]; 476 int cpu; 477 478 for_each_possible_cpu(cpu) { 479 bpf_obj_free_fields(map->record, per_cpu_ptr(pptr, cpu)); 480 cond_resched(); 481 } 482 } 483 } else { 484 for (i = 0; i < array->map.max_entries; i++) 485 bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i)); 486 } 487 } 488 489 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) 490 bpf_array_free_percpu(array); 491 492 if (array->map.map_flags & BPF_F_MMAPABLE) 493 bpf_map_area_free(array_map_vmalloc_addr(array)); 494 else 495 bpf_map_area_free(array); 496 } 497 498 static void array_map_seq_show_elem(struct bpf_map *map, void *key, 499 struct seq_file *m) 500 { 501 void *value; 502 503 rcu_read_lock(); 504 505 value = array_map_lookup_elem(map, key); 506 if (!value) { 507 rcu_read_unlock(); 508 return; 509 } 510 511 if (map->btf_key_type_id) 512 seq_printf(m, "%u: ", *(u32 *)key); 513 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m); 514 seq_putc(m, '\n'); 515 516 rcu_read_unlock(); 517 } 518 519 static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key, 520 struct seq_file *m) 521 { 522 struct bpf_array *array = container_of(map, struct bpf_array, map); 523 u32 index = *(u32 *)key; 524 void __percpu *pptr; 525 int cpu; 526 527 rcu_read_lock(); 528 529 seq_printf(m, "%u: {\n", *(u32 *)key); 530 pptr = array->pptrs[index & array->index_mask]; 531 for_each_possible_cpu(cpu) { 532 seq_printf(m, "\tcpu%d: ", cpu); 533 btf_type_seq_show(map->btf, map->btf_value_type_id, 534 per_cpu_ptr(pptr, cpu), m); 535 seq_putc(m, '\n'); 536 } 537 seq_puts(m, "}\n"); 538 539 rcu_read_unlock(); 540 } 541 542 static int array_map_check_btf(const struct bpf_map *map, 543 const struct btf *btf, 544 const struct btf_type *key_type, 545 const struct btf_type *value_type) 546 { 547 /* One exception for keyless BTF: .bss/.data/.rodata map */ 548 if (btf_type_is_void(key_type)) { 549 if (map->map_type != BPF_MAP_TYPE_ARRAY || 550 map->max_entries != 1) 551 return -EINVAL; 552 553 if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC) 554 return -EINVAL; 555 556 return 0; 557 } 558 559 /* 560 * Bpf array can only take a u32 key. This check makes sure 561 * that the btf matches the attr used during map_create. 562 */ 563 if (!btf_type_is_i32(key_type)) 564 return -EINVAL; 565 566 return 0; 567 } 568 569 static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma) 570 { 571 struct bpf_array *array = container_of(map, struct bpf_array, map); 572 pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT; 573 574 if (!(map->map_flags & BPF_F_MMAPABLE)) 575 return -EINVAL; 576 577 if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) > 578 PAGE_ALIGN((u64)array->map.max_entries * array->elem_size)) 579 return -EINVAL; 580 581 return remap_vmalloc_range(vma, array_map_vmalloc_addr(array), 582 vma->vm_pgoff + pgoff); 583 } 584 585 static bool array_map_meta_equal(const struct bpf_map *meta0, 586 const struct bpf_map *meta1) 587 { 588 if (!bpf_map_meta_equal(meta0, meta1)) 589 return false; 590 return meta0->map_flags & BPF_F_INNER_MAP ? true : 591 meta0->max_entries == meta1->max_entries; 592 } 593 594 struct bpf_iter_seq_array_map_info { 595 struct bpf_map *map; 596 void *percpu_value_buf; 597 u32 index; 598 }; 599 600 static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos) 601 { 602 struct bpf_iter_seq_array_map_info *info = seq->private; 603 struct bpf_map *map = info->map; 604 struct bpf_array *array; 605 u32 index; 606 607 if (info->index >= map->max_entries) 608 return NULL; 609 610 if (*pos == 0) 611 ++*pos; 612 array = container_of(map, struct bpf_array, map); 613 index = info->index & array->index_mask; 614 if (info->percpu_value_buf) 615 return (void *)(uintptr_t)array->pptrs[index]; 616 return array_map_elem_ptr(array, index); 617 } 618 619 static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) 620 { 621 struct bpf_iter_seq_array_map_info *info = seq->private; 622 struct bpf_map *map = info->map; 623 struct bpf_array *array; 624 u32 index; 625 626 ++*pos; 627 ++info->index; 628 if (info->index >= map->max_entries) 629 return NULL; 630 631 array = container_of(map, struct bpf_array, map); 632 index = info->index & array->index_mask; 633 if (info->percpu_value_buf) 634 return (void *)(uintptr_t)array->pptrs[index]; 635 return array_map_elem_ptr(array, index); 636 } 637 638 static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) 639 { 640 struct bpf_iter_seq_array_map_info *info = seq->private; 641 struct bpf_iter__bpf_map_elem ctx = {}; 642 struct bpf_map *map = info->map; 643 struct bpf_array *array = container_of(map, struct bpf_array, map); 644 struct bpf_iter_meta meta; 645 struct bpf_prog *prog; 646 int off = 0, cpu = 0; 647 void __percpu *pptr; 648 u32 size; 649 650 meta.seq = seq; 651 prog = bpf_iter_get_info(&meta, v == NULL); 652 if (!prog) 653 return 0; 654 655 ctx.meta = &meta; 656 ctx.map = info->map; 657 if (v) { 658 ctx.key = &info->index; 659 660 if (!info->percpu_value_buf) { 661 ctx.value = v; 662 } else { 663 pptr = (void __percpu *)(uintptr_t)v; 664 size = array->elem_size; 665 for_each_possible_cpu(cpu) { 666 copy_map_value_long(map, info->percpu_value_buf + off, 667 per_cpu_ptr(pptr, cpu)); 668 check_and_init_map_value(map, info->percpu_value_buf + off); 669 off += size; 670 } 671 ctx.value = info->percpu_value_buf; 672 } 673 } 674 675 return bpf_iter_run_prog(prog, &ctx); 676 } 677 678 static int bpf_array_map_seq_show(struct seq_file *seq, void *v) 679 { 680 return __bpf_array_map_seq_show(seq, v); 681 } 682 683 static void bpf_array_map_seq_stop(struct seq_file *seq, void *v) 684 { 685 if (!v) 686 (void)__bpf_array_map_seq_show(seq, NULL); 687 } 688 689 static int bpf_iter_init_array_map(void *priv_data, 690 struct bpf_iter_aux_info *aux) 691 { 692 struct bpf_iter_seq_array_map_info *seq_info = priv_data; 693 struct bpf_map *map = aux->map; 694 struct bpf_array *array = container_of(map, struct bpf_array, map); 695 void *value_buf; 696 u32 buf_size; 697 698 if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 699 buf_size = array->elem_size * num_possible_cpus(); 700 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN); 701 if (!value_buf) 702 return -ENOMEM; 703 704 seq_info->percpu_value_buf = value_buf; 705 } 706 707 /* bpf_iter_attach_map() acquires a map uref, and the uref may be 708 * released before or in the middle of iterating map elements, so 709 * acquire an extra map uref for iterator. 710 */ 711 bpf_map_inc_with_uref(map); 712 seq_info->map = map; 713 return 0; 714 } 715 716 static void bpf_iter_fini_array_map(void *priv_data) 717 { 718 struct bpf_iter_seq_array_map_info *seq_info = priv_data; 719 720 bpf_map_put_with_uref(seq_info->map); 721 kfree(seq_info->percpu_value_buf); 722 } 723 724 static const struct seq_operations bpf_array_map_seq_ops = { 725 .start = bpf_array_map_seq_start, 726 .next = bpf_array_map_seq_next, 727 .stop = bpf_array_map_seq_stop, 728 .show = bpf_array_map_seq_show, 729 }; 730 731 static const struct bpf_iter_seq_info iter_seq_info = { 732 .seq_ops = &bpf_array_map_seq_ops, 733 .init_seq_private = bpf_iter_init_array_map, 734 .fini_seq_private = bpf_iter_fini_array_map, 735 .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info), 736 }; 737 738 static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn, 739 void *callback_ctx, u64 flags) 740 { 741 u32 i, key, num_elems = 0; 742 struct bpf_array *array; 743 bool is_percpu; 744 u64 ret = 0; 745 void *val; 746 747 cant_migrate(); 748 749 if (flags != 0) 750 return -EINVAL; 751 752 is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 753 array = container_of(map, struct bpf_array, map); 754 for (i = 0; i < map->max_entries; i++) { 755 if (is_percpu) 756 val = this_cpu_ptr(array->pptrs[i]); 757 else 758 val = array_map_elem_ptr(array, i); 759 num_elems++; 760 key = i; 761 ret = callback_fn((u64)(long)map, (u64)(long)&key, 762 (u64)(long)val, (u64)(long)callback_ctx, 0); 763 /* return value: 0 - continue, 1 - stop and return */ 764 if (ret) 765 break; 766 } 767 768 return num_elems; 769 } 770 771 static u64 array_map_mem_usage(const struct bpf_map *map) 772 { 773 struct bpf_array *array = container_of(map, struct bpf_array, map); 774 bool percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; 775 u32 elem_size = array->elem_size; 776 u64 entries = map->max_entries; 777 u64 usage = sizeof(*array); 778 779 if (percpu) { 780 usage += entries * sizeof(void *); 781 usage += entries * elem_size * num_possible_cpus(); 782 } else { 783 if (map->map_flags & BPF_F_MMAPABLE) { 784 usage = PAGE_ALIGN(usage); 785 usage += PAGE_ALIGN(entries * elem_size); 786 } else { 787 usage += entries * elem_size; 788 } 789 } 790 return usage; 791 } 792 793 BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array) 794 const struct bpf_map_ops array_map_ops = { 795 .map_meta_equal = array_map_meta_equal, 796 .map_alloc_check = array_map_alloc_check, 797 .map_alloc = array_map_alloc, 798 .map_free = array_map_free, 799 .map_get_next_key = array_map_get_next_key, 800 .map_release_uref = array_map_free_internal_structs, 801 .map_lookup_elem = array_map_lookup_elem, 802 .map_update_elem = array_map_update_elem, 803 .map_delete_elem = array_map_delete_elem, 804 .map_gen_lookup = array_map_gen_lookup, 805 .map_direct_value_addr = array_map_direct_value_addr, 806 .map_direct_value_meta = array_map_direct_value_meta, 807 .map_mmap = array_map_mmap, 808 .map_seq_show_elem = array_map_seq_show_elem, 809 .map_check_btf = array_map_check_btf, 810 .map_lookup_batch = generic_map_lookup_batch, 811 .map_update_batch = generic_map_update_batch, 812 .map_set_for_each_callback_args = map_set_for_each_callback_args, 813 .map_for_each_callback = bpf_for_each_array_elem, 814 .map_mem_usage = array_map_mem_usage, 815 .map_btf_id = &array_map_btf_ids[0], 816 .iter_seq_info = &iter_seq_info, 817 .map_get_hash = &array_map_get_hash, 818 }; 819 820 const struct bpf_map_ops percpu_array_map_ops = { 821 .map_meta_equal = bpf_map_meta_equal, 822 .map_alloc_check = array_map_alloc_check, 823 .map_alloc = array_map_alloc, 824 .map_free = array_map_free, 825 .map_get_next_key = array_map_get_next_key, 826 .map_lookup_elem = percpu_array_map_lookup_elem, 827 .map_gen_lookup = percpu_array_map_gen_lookup, 828 .map_update_elem = array_map_update_elem, 829 .map_delete_elem = array_map_delete_elem, 830 .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem, 831 .map_seq_show_elem = percpu_array_map_seq_show_elem, 832 .map_check_btf = array_map_check_btf, 833 .map_lookup_batch = generic_map_lookup_batch, 834 .map_update_batch = generic_map_update_batch, 835 .map_set_for_each_callback_args = map_set_for_each_callback_args, 836 .map_for_each_callback = bpf_for_each_array_elem, 837 .map_mem_usage = array_map_mem_usage, 838 .map_btf_id = &array_map_btf_ids[0], 839 .iter_seq_info = &iter_seq_info, 840 }; 841 842 static int fd_array_map_alloc_check(union bpf_attr *attr) 843 { 844 /* only file descriptors can be stored in this type of map */ 845 if (attr->value_size != sizeof(u32)) 846 return -EINVAL; 847 /* Program read-only/write-only not supported for special maps yet. */ 848 if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) 849 return -EINVAL; 850 return array_map_alloc_check(attr); 851 } 852 853 static void fd_array_map_free(struct bpf_map *map) 854 { 855 struct bpf_array *array = container_of(map, struct bpf_array, map); 856 int i; 857 858 /* make sure it's empty */ 859 for (i = 0; i < array->map.max_entries; i++) 860 BUG_ON(array->ptrs[i] != NULL); 861 862 bpf_map_area_free(array); 863 } 864 865 static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) 866 { 867 return ERR_PTR(-EOPNOTSUPP); 868 } 869 870 /* only called from syscall */ 871 int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) 872 { 873 void **elem, *ptr; 874 int ret = 0; 875 876 if (!map->ops->map_fd_sys_lookup_elem) 877 return -ENOTSUPP; 878 879 rcu_read_lock(); 880 elem = array_map_lookup_elem(map, key); 881 if (elem && (ptr = READ_ONCE(*elem))) 882 *value = map->ops->map_fd_sys_lookup_elem(ptr); 883 else 884 ret = -ENOENT; 885 rcu_read_unlock(); 886 887 return ret; 888 } 889 890 /* only called from syscall */ 891 int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, 892 void *key, void *value, u64 map_flags) 893 { 894 struct bpf_array *array = container_of(map, struct bpf_array, map); 895 void *new_ptr, *old_ptr; 896 u32 index = *(u32 *)key, ufd; 897 898 if (map_flags != BPF_ANY) 899 return -EINVAL; 900 901 if (index >= array->map.max_entries) 902 return -E2BIG; 903 904 ufd = *(u32 *)value; 905 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd); 906 if (IS_ERR(new_ptr)) 907 return PTR_ERR(new_ptr); 908 909 if (map->ops->map_poke_run) { 910 mutex_lock(&array->aux->poke_mutex); 911 old_ptr = xchg(array->ptrs + index, new_ptr); 912 map->ops->map_poke_run(map, index, old_ptr, new_ptr); 913 mutex_unlock(&array->aux->poke_mutex); 914 } else { 915 old_ptr = xchg(array->ptrs + index, new_ptr); 916 } 917 918 if (old_ptr) 919 map->ops->map_fd_put_ptr(map, old_ptr, true); 920 return 0; 921 } 922 923 static long __fd_array_map_delete_elem(struct bpf_map *map, void *key, bool need_defer) 924 { 925 struct bpf_array *array = container_of(map, struct bpf_array, map); 926 void *old_ptr; 927 u32 index = *(u32 *)key; 928 929 if (index >= array->map.max_entries) 930 return -E2BIG; 931 932 if (map->ops->map_poke_run) { 933 mutex_lock(&array->aux->poke_mutex); 934 old_ptr = xchg(array->ptrs + index, NULL); 935 map->ops->map_poke_run(map, index, old_ptr, NULL); 936 mutex_unlock(&array->aux->poke_mutex); 937 } else { 938 old_ptr = xchg(array->ptrs + index, NULL); 939 } 940 941 if (old_ptr) { 942 map->ops->map_fd_put_ptr(map, old_ptr, need_defer); 943 return 0; 944 } else { 945 return -ENOENT; 946 } 947 } 948 949 static long fd_array_map_delete_elem(struct bpf_map *map, void *key) 950 { 951 return __fd_array_map_delete_elem(map, key, true); 952 } 953 954 static void *prog_fd_array_get_ptr(struct bpf_map *map, 955 struct file *map_file, int fd) 956 { 957 struct bpf_prog *prog = bpf_prog_get(fd); 958 bool is_extended; 959 960 if (IS_ERR(prog)) 961 return prog; 962 963 if (prog->type == BPF_PROG_TYPE_EXT || 964 !bpf_prog_map_compatible(map, prog)) { 965 bpf_prog_put(prog); 966 return ERR_PTR(-EINVAL); 967 } 968 969 mutex_lock(&prog->aux->ext_mutex); 970 is_extended = prog->aux->is_extended; 971 if (!is_extended) 972 prog->aux->prog_array_member_cnt++; 973 mutex_unlock(&prog->aux->ext_mutex); 974 if (is_extended) { 975 /* Extended prog can not be tail callee. It's to prevent a 976 * potential infinite loop like: 977 * tail callee prog entry -> tail callee prog subprog -> 978 * freplace prog entry --tailcall-> tail callee prog entry. 979 */ 980 bpf_prog_put(prog); 981 return ERR_PTR(-EBUSY); 982 } 983 984 return prog; 985 } 986 987 static void prog_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) 988 { 989 struct bpf_prog *prog = ptr; 990 991 mutex_lock(&prog->aux->ext_mutex); 992 prog->aux->prog_array_member_cnt--; 993 mutex_unlock(&prog->aux->ext_mutex); 994 /* bpf_prog is freed after one RCU or tasks trace grace period */ 995 bpf_prog_put(prog); 996 } 997 998 static u32 prog_fd_array_sys_lookup_elem(void *ptr) 999 { 1000 return ((struct bpf_prog *)ptr)->aux->id; 1001 } 1002 1003 /* decrement refcnt of all bpf_progs that are stored in this map */ 1004 static void bpf_fd_array_map_clear(struct bpf_map *map, bool need_defer) 1005 { 1006 struct bpf_array *array = container_of(map, struct bpf_array, map); 1007 int i; 1008 1009 for (i = 0; i < array->map.max_entries; i++) 1010 __fd_array_map_delete_elem(map, &i, need_defer); 1011 } 1012 1013 static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key, 1014 struct seq_file *m) 1015 { 1016 void **elem, *ptr; 1017 u32 prog_id; 1018 1019 rcu_read_lock(); 1020 1021 elem = array_map_lookup_elem(map, key); 1022 if (elem) { 1023 ptr = READ_ONCE(*elem); 1024 if (ptr) { 1025 seq_printf(m, "%u: ", *(u32 *)key); 1026 prog_id = prog_fd_array_sys_lookup_elem(ptr); 1027 btf_type_seq_show(map->btf, map->btf_value_type_id, 1028 &prog_id, m); 1029 seq_putc(m, '\n'); 1030 } 1031 } 1032 1033 rcu_read_unlock(); 1034 } 1035 1036 struct prog_poke_elem { 1037 struct list_head list; 1038 struct bpf_prog_aux *aux; 1039 }; 1040 1041 static int prog_array_map_poke_track(struct bpf_map *map, 1042 struct bpf_prog_aux *prog_aux) 1043 { 1044 struct prog_poke_elem *elem; 1045 struct bpf_array_aux *aux; 1046 int ret = 0; 1047 1048 aux = container_of(map, struct bpf_array, map)->aux; 1049 mutex_lock(&aux->poke_mutex); 1050 list_for_each_entry(elem, &aux->poke_progs, list) { 1051 if (elem->aux == prog_aux) 1052 goto out; 1053 } 1054 1055 elem = kmalloc(sizeof(*elem), GFP_KERNEL); 1056 if (!elem) { 1057 ret = -ENOMEM; 1058 goto out; 1059 } 1060 1061 INIT_LIST_HEAD(&elem->list); 1062 /* We must track the program's aux info at this point in time 1063 * since the program pointer itself may not be stable yet, see 1064 * also comment in prog_array_map_poke_run(). 1065 */ 1066 elem->aux = prog_aux; 1067 1068 list_add_tail(&elem->list, &aux->poke_progs); 1069 out: 1070 mutex_unlock(&aux->poke_mutex); 1071 return ret; 1072 } 1073 1074 static void prog_array_map_poke_untrack(struct bpf_map *map, 1075 struct bpf_prog_aux *prog_aux) 1076 { 1077 struct prog_poke_elem *elem, *tmp; 1078 struct bpf_array_aux *aux; 1079 1080 aux = container_of(map, struct bpf_array, map)->aux; 1081 mutex_lock(&aux->poke_mutex); 1082 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) { 1083 if (elem->aux == prog_aux) { 1084 list_del_init(&elem->list); 1085 kfree(elem); 1086 break; 1087 } 1088 } 1089 mutex_unlock(&aux->poke_mutex); 1090 } 1091 1092 void __weak bpf_arch_poke_desc_update(struct bpf_jit_poke_descriptor *poke, 1093 struct bpf_prog *new, struct bpf_prog *old) 1094 { 1095 WARN_ON_ONCE(1); 1096 } 1097 1098 static void prog_array_map_poke_run(struct bpf_map *map, u32 key, 1099 struct bpf_prog *old, 1100 struct bpf_prog *new) 1101 { 1102 struct prog_poke_elem *elem; 1103 struct bpf_array_aux *aux; 1104 1105 aux = container_of(map, struct bpf_array, map)->aux; 1106 WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex)); 1107 1108 list_for_each_entry(elem, &aux->poke_progs, list) { 1109 struct bpf_jit_poke_descriptor *poke; 1110 int i; 1111 1112 for (i = 0; i < elem->aux->size_poke_tab; i++) { 1113 poke = &elem->aux->poke_tab[i]; 1114 1115 /* Few things to be aware of: 1116 * 1117 * 1) We can only ever access aux in this context, but 1118 * not aux->prog since it might not be stable yet and 1119 * there could be danger of use after free otherwise. 1120 * 2) Initially when we start tracking aux, the program 1121 * is not JITed yet and also does not have a kallsyms 1122 * entry. We skip these as poke->tailcall_target_stable 1123 * is not active yet. The JIT will do the final fixup 1124 * before setting it stable. The various 1125 * poke->tailcall_target_stable are successively 1126 * activated, so tail call updates can arrive from here 1127 * while JIT is still finishing its final fixup for 1128 * non-activated poke entries. 1129 * 3) Also programs reaching refcount of zero while patching 1130 * is in progress is okay since we're protected under 1131 * poke_mutex and untrack the programs before the JIT 1132 * buffer is freed. 1133 */ 1134 if (!READ_ONCE(poke->tailcall_target_stable)) 1135 continue; 1136 if (poke->reason != BPF_POKE_REASON_TAIL_CALL) 1137 continue; 1138 if (poke->tail_call.map != map || 1139 poke->tail_call.key != key) 1140 continue; 1141 1142 bpf_arch_poke_desc_update(poke, new, old); 1143 } 1144 } 1145 } 1146 1147 static void prog_array_map_clear_deferred(struct work_struct *work) 1148 { 1149 struct bpf_map *map = container_of(work, struct bpf_array_aux, 1150 work)->map; 1151 bpf_fd_array_map_clear(map, true); 1152 bpf_map_put(map); 1153 } 1154 1155 static void prog_array_map_clear(struct bpf_map *map) 1156 { 1157 struct bpf_array_aux *aux = container_of(map, struct bpf_array, 1158 map)->aux; 1159 bpf_map_inc(map); 1160 schedule_work(&aux->work); 1161 } 1162 1163 static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr) 1164 { 1165 struct bpf_array_aux *aux; 1166 struct bpf_map *map; 1167 1168 aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT); 1169 if (!aux) 1170 return ERR_PTR(-ENOMEM); 1171 1172 INIT_WORK(&aux->work, prog_array_map_clear_deferred); 1173 INIT_LIST_HEAD(&aux->poke_progs); 1174 mutex_init(&aux->poke_mutex); 1175 1176 map = array_map_alloc(attr); 1177 if (IS_ERR(map)) { 1178 kfree(aux); 1179 return map; 1180 } 1181 1182 container_of(map, struct bpf_array, map)->aux = aux; 1183 aux->map = map; 1184 1185 return map; 1186 } 1187 1188 static void prog_array_map_free(struct bpf_map *map) 1189 { 1190 struct prog_poke_elem *elem, *tmp; 1191 struct bpf_array_aux *aux; 1192 1193 aux = container_of(map, struct bpf_array, map)->aux; 1194 list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) { 1195 list_del_init(&elem->list); 1196 kfree(elem); 1197 } 1198 kfree(aux); 1199 fd_array_map_free(map); 1200 } 1201 1202 /* prog_array->aux->{type,jited} is a runtime binding. 1203 * Doing static check alone in the verifier is not enough. 1204 * Thus, prog_array_map cannot be used as an inner_map 1205 * and map_meta_equal is not implemented. 1206 */ 1207 const struct bpf_map_ops prog_array_map_ops = { 1208 .map_alloc_check = fd_array_map_alloc_check, 1209 .map_alloc = prog_array_map_alloc, 1210 .map_free = prog_array_map_free, 1211 .map_poke_track = prog_array_map_poke_track, 1212 .map_poke_untrack = prog_array_map_poke_untrack, 1213 .map_poke_run = prog_array_map_poke_run, 1214 .map_get_next_key = array_map_get_next_key, 1215 .map_lookup_elem = fd_array_map_lookup_elem, 1216 .map_delete_elem = fd_array_map_delete_elem, 1217 .map_fd_get_ptr = prog_fd_array_get_ptr, 1218 .map_fd_put_ptr = prog_fd_array_put_ptr, 1219 .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, 1220 .map_release_uref = prog_array_map_clear, 1221 .map_seq_show_elem = prog_array_map_seq_show_elem, 1222 .map_mem_usage = array_map_mem_usage, 1223 .map_btf_id = &array_map_btf_ids[0], 1224 }; 1225 1226 static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, 1227 struct file *map_file) 1228 { 1229 struct bpf_event_entry *ee; 1230 1231 ee = kzalloc(sizeof(*ee), GFP_KERNEL); 1232 if (ee) { 1233 ee->event = perf_file->private_data; 1234 ee->perf_file = perf_file; 1235 ee->map_file = map_file; 1236 } 1237 1238 return ee; 1239 } 1240 1241 static void __bpf_event_entry_free(struct rcu_head *rcu) 1242 { 1243 struct bpf_event_entry *ee; 1244 1245 ee = container_of(rcu, struct bpf_event_entry, rcu); 1246 fput(ee->perf_file); 1247 kfree(ee); 1248 } 1249 1250 static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee) 1251 { 1252 call_rcu(&ee->rcu, __bpf_event_entry_free); 1253 } 1254 1255 static void *perf_event_fd_array_get_ptr(struct bpf_map *map, 1256 struct file *map_file, int fd) 1257 { 1258 struct bpf_event_entry *ee; 1259 struct perf_event *event; 1260 struct file *perf_file; 1261 u64 value; 1262 1263 perf_file = perf_event_get(fd); 1264 if (IS_ERR(perf_file)) 1265 return perf_file; 1266 1267 ee = ERR_PTR(-EOPNOTSUPP); 1268 event = perf_file->private_data; 1269 if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP) 1270 goto err_out; 1271 1272 ee = bpf_event_entry_gen(perf_file, map_file); 1273 if (ee) 1274 return ee; 1275 ee = ERR_PTR(-ENOMEM); 1276 err_out: 1277 fput(perf_file); 1278 return ee; 1279 } 1280 1281 static void perf_event_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) 1282 { 1283 /* bpf_perf_event is freed after one RCU grace period */ 1284 bpf_event_entry_free_rcu(ptr); 1285 } 1286 1287 static void perf_event_fd_array_release(struct bpf_map *map, 1288 struct file *map_file) 1289 { 1290 struct bpf_array *array = container_of(map, struct bpf_array, map); 1291 struct bpf_event_entry *ee; 1292 int i; 1293 1294 if (map->map_flags & BPF_F_PRESERVE_ELEMS) 1295 return; 1296 1297 rcu_read_lock(); 1298 for (i = 0; i < array->map.max_entries; i++) { 1299 ee = READ_ONCE(array->ptrs[i]); 1300 if (ee && ee->map_file == map_file) 1301 __fd_array_map_delete_elem(map, &i, true); 1302 } 1303 rcu_read_unlock(); 1304 } 1305 1306 static void perf_event_fd_array_map_free(struct bpf_map *map) 1307 { 1308 if (map->map_flags & BPF_F_PRESERVE_ELEMS) 1309 bpf_fd_array_map_clear(map, false); 1310 fd_array_map_free(map); 1311 } 1312 1313 const struct bpf_map_ops perf_event_array_map_ops = { 1314 .map_meta_equal = bpf_map_meta_equal, 1315 .map_alloc_check = fd_array_map_alloc_check, 1316 .map_alloc = array_map_alloc, 1317 .map_free = perf_event_fd_array_map_free, 1318 .map_get_next_key = array_map_get_next_key, 1319 .map_lookup_elem = fd_array_map_lookup_elem, 1320 .map_delete_elem = fd_array_map_delete_elem, 1321 .map_fd_get_ptr = perf_event_fd_array_get_ptr, 1322 .map_fd_put_ptr = perf_event_fd_array_put_ptr, 1323 .map_release = perf_event_fd_array_release, 1324 .map_check_btf = map_check_no_btf, 1325 .map_mem_usage = array_map_mem_usage, 1326 .map_btf_id = &array_map_btf_ids[0], 1327 }; 1328 1329 #ifdef CONFIG_CGROUPS 1330 static void *cgroup_fd_array_get_ptr(struct bpf_map *map, 1331 struct file *map_file /* not used */, 1332 int fd) 1333 { 1334 return cgroup_get_from_fd(fd); 1335 } 1336 1337 static void cgroup_fd_array_put_ptr(struct bpf_map *map, void *ptr, bool need_defer) 1338 { 1339 /* cgroup_put free cgrp after a rcu grace period */ 1340 cgroup_put(ptr); 1341 } 1342 1343 static void cgroup_fd_array_free(struct bpf_map *map) 1344 { 1345 bpf_fd_array_map_clear(map, false); 1346 fd_array_map_free(map); 1347 } 1348 1349 const struct bpf_map_ops cgroup_array_map_ops = { 1350 .map_meta_equal = bpf_map_meta_equal, 1351 .map_alloc_check = fd_array_map_alloc_check, 1352 .map_alloc = array_map_alloc, 1353 .map_free = cgroup_fd_array_free, 1354 .map_get_next_key = array_map_get_next_key, 1355 .map_lookup_elem = fd_array_map_lookup_elem, 1356 .map_delete_elem = fd_array_map_delete_elem, 1357 .map_fd_get_ptr = cgroup_fd_array_get_ptr, 1358 .map_fd_put_ptr = cgroup_fd_array_put_ptr, 1359 .map_check_btf = map_check_no_btf, 1360 .map_mem_usage = array_map_mem_usage, 1361 .map_btf_id = &array_map_btf_ids[0], 1362 }; 1363 #endif 1364 1365 static struct bpf_map *array_of_map_alloc(union bpf_attr *attr) 1366 { 1367 struct bpf_map *map, *inner_map_meta; 1368 1369 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd); 1370 if (IS_ERR(inner_map_meta)) 1371 return inner_map_meta; 1372 1373 map = array_map_alloc(attr); 1374 if (IS_ERR(map)) { 1375 bpf_map_meta_free(inner_map_meta); 1376 return map; 1377 } 1378 1379 map->inner_map_meta = inner_map_meta; 1380 1381 return map; 1382 } 1383 1384 static void array_of_map_free(struct bpf_map *map) 1385 { 1386 /* map->inner_map_meta is only accessed by syscall which 1387 * is protected by fdget/fdput. 1388 */ 1389 bpf_map_meta_free(map->inner_map_meta); 1390 bpf_fd_array_map_clear(map, false); 1391 fd_array_map_free(map); 1392 } 1393 1394 static void *array_of_map_lookup_elem(struct bpf_map *map, void *key) 1395 { 1396 struct bpf_map **inner_map = array_map_lookup_elem(map, key); 1397 1398 if (!inner_map) 1399 return NULL; 1400 1401 return READ_ONCE(*inner_map); 1402 } 1403 1404 static int array_of_map_gen_lookup(struct bpf_map *map, 1405 struct bpf_insn *insn_buf) 1406 { 1407 struct bpf_array *array = container_of(map, struct bpf_array, map); 1408 u32 elem_size = array->elem_size; 1409 struct bpf_insn *insn = insn_buf; 1410 const int ret = BPF_REG_0; 1411 const int map_ptr = BPF_REG_1; 1412 const int index = BPF_REG_2; 1413 1414 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); 1415 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); 1416 if (!map->bypass_spec_v1) { 1417 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6); 1418 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); 1419 } else { 1420 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5); 1421 } 1422 if (is_power_of_2(elem_size)) 1423 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); 1424 else 1425 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); 1426 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); 1427 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0); 1428 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1); 1429 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); 1430 *insn++ = BPF_MOV64_IMM(ret, 0); 1431 1432 return insn - insn_buf; 1433 } 1434 1435 const struct bpf_map_ops array_of_maps_map_ops = { 1436 .map_alloc_check = fd_array_map_alloc_check, 1437 .map_alloc = array_of_map_alloc, 1438 .map_free = array_of_map_free, 1439 .map_get_next_key = array_map_get_next_key, 1440 .map_lookup_elem = array_of_map_lookup_elem, 1441 .map_delete_elem = fd_array_map_delete_elem, 1442 .map_fd_get_ptr = bpf_map_fd_get_ptr, 1443 .map_fd_put_ptr = bpf_map_fd_put_ptr, 1444 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, 1445 .map_gen_lookup = array_of_map_gen_lookup, 1446 .map_lookup_batch = generic_map_lookup_batch, 1447 .map_update_batch = generic_map_update_batch, 1448 .map_check_btf = map_check_no_btf, 1449 .map_mem_usage = array_map_mem_usage, 1450 .map_btf_id = &array_map_btf_ids[0], 1451 }; 1452