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