1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 2 3 /* 4 * Common eBPF ELF object loading operations. 5 * 6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 8 * Copyright (C) 2015 Huawei Inc. 9 * Copyright (C) 2017 Nicira, Inc. 10 * Copyright (C) 2019 Isovalent, Inc. 11 */ 12 13 #ifndef _GNU_SOURCE 14 #define _GNU_SOURCE 15 #endif 16 #include <stdlib.h> 17 #include <stdio.h> 18 #include <stdarg.h> 19 #include <libgen.h> 20 #include <inttypes.h> 21 #include <string.h> 22 #include <unistd.h> 23 #include <endian.h> 24 #include <fcntl.h> 25 #include <errno.h> 26 #include <asm/unistd.h> 27 #include <linux/err.h> 28 #include <linux/kernel.h> 29 #include <linux/bpf.h> 30 #include <linux/btf.h> 31 #include <linux/filter.h> 32 #include <linux/list.h> 33 #include <linux/limits.h> 34 #include <linux/perf_event.h> 35 #include <linux/ring_buffer.h> 36 #include <sys/epoll.h> 37 #include <sys/ioctl.h> 38 #include <sys/mman.h> 39 #include <sys/stat.h> 40 #include <sys/types.h> 41 #include <sys/vfs.h> 42 #include <tools/libc_compat.h> 43 #include <libelf.h> 44 #include <gelf.h> 45 46 #include "libbpf.h" 47 #include "bpf.h" 48 #include "btf.h" 49 #include "str_error.h" 50 #include "libbpf_internal.h" 51 52 #ifndef EM_BPF 53 #define EM_BPF 247 54 #endif 55 56 #ifndef BPF_FS_MAGIC 57 #define BPF_FS_MAGIC 0xcafe4a11 58 #endif 59 60 /* vsprintf() in __base_pr() uses nonliteral format string. It may break 61 * compilation if user enables corresponding warning. Disable it explicitly. 62 */ 63 #pragma GCC diagnostic ignored "-Wformat-nonliteral" 64 65 #define __printf(a, b) __attribute__((format(printf, a, b))) 66 67 static int __base_pr(enum libbpf_print_level level, const char *format, 68 va_list args) 69 { 70 if (level == LIBBPF_DEBUG) 71 return 0; 72 73 return vfprintf(stderr, format, args); 74 } 75 76 static libbpf_print_fn_t __libbpf_pr = __base_pr; 77 78 void libbpf_set_print(libbpf_print_fn_t fn) 79 { 80 __libbpf_pr = fn; 81 } 82 83 __printf(2, 3) 84 void libbpf_print(enum libbpf_print_level level, const char *format, ...) 85 { 86 va_list args; 87 88 if (!__libbpf_pr) 89 return; 90 91 va_start(args, format); 92 __libbpf_pr(level, format, args); 93 va_end(args); 94 } 95 96 #define STRERR_BUFSIZE 128 97 98 #define CHECK_ERR(action, err, out) do { \ 99 err = action; \ 100 if (err) \ 101 goto out; \ 102 } while(0) 103 104 105 /* Copied from tools/perf/util/util.h */ 106 #ifndef zfree 107 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; }) 108 #endif 109 110 #ifndef zclose 111 # define zclose(fd) ({ \ 112 int ___err = 0; \ 113 if ((fd) >= 0) \ 114 ___err = close((fd)); \ 115 fd = -1; \ 116 ___err; }) 117 #endif 118 119 #ifdef HAVE_LIBELF_MMAP_SUPPORT 120 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP 121 #else 122 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ 123 #endif 124 125 static inline __u64 ptr_to_u64(const void *ptr) 126 { 127 return (__u64) (unsigned long) ptr; 128 } 129 130 struct bpf_capabilities { 131 /* v4.14: kernel support for program & map names. */ 132 __u32 name:1; 133 /* v5.2: kernel support for global data sections. */ 134 __u32 global_data:1; 135 /* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */ 136 __u32 btf_func:1; 137 /* BTF_KIND_VAR and BTF_KIND_DATASEC support */ 138 __u32 btf_datasec:1; 139 }; 140 141 /* 142 * bpf_prog should be a better name but it has been used in 143 * linux/filter.h. 144 */ 145 struct bpf_program { 146 /* Index in elf obj file, for relocation use. */ 147 int idx; 148 char *name; 149 int prog_ifindex; 150 char *section_name; 151 /* section_name with / replaced by _; makes recursive pinning 152 * in bpf_object__pin_programs easier 153 */ 154 char *pin_name; 155 struct bpf_insn *insns; 156 size_t insns_cnt, main_prog_cnt; 157 enum bpf_prog_type type; 158 159 struct reloc_desc { 160 enum { 161 RELO_LD64, 162 RELO_CALL, 163 RELO_DATA, 164 } type; 165 int insn_idx; 166 union { 167 int map_idx; 168 int text_off; 169 }; 170 } *reloc_desc; 171 int nr_reloc; 172 int log_level; 173 174 struct { 175 int nr; 176 int *fds; 177 } instances; 178 bpf_program_prep_t preprocessor; 179 180 struct bpf_object *obj; 181 void *priv; 182 bpf_program_clear_priv_t clear_priv; 183 184 enum bpf_attach_type expected_attach_type; 185 int btf_fd; 186 void *func_info; 187 __u32 func_info_rec_size; 188 __u32 func_info_cnt; 189 190 struct bpf_capabilities *caps; 191 192 void *line_info; 193 __u32 line_info_rec_size; 194 __u32 line_info_cnt; 195 __u32 prog_flags; 196 }; 197 198 enum libbpf_map_type { 199 LIBBPF_MAP_UNSPEC, 200 LIBBPF_MAP_DATA, 201 LIBBPF_MAP_BSS, 202 LIBBPF_MAP_RODATA, 203 }; 204 205 static const char * const libbpf_type_to_btf_name[] = { 206 [LIBBPF_MAP_DATA] = ".data", 207 [LIBBPF_MAP_BSS] = ".bss", 208 [LIBBPF_MAP_RODATA] = ".rodata", 209 }; 210 211 struct bpf_map { 212 int fd; 213 char *name; 214 int sec_idx; 215 size_t sec_offset; 216 int map_ifindex; 217 int inner_map_fd; 218 struct bpf_map_def def; 219 __u32 btf_key_type_id; 220 __u32 btf_value_type_id; 221 void *priv; 222 bpf_map_clear_priv_t clear_priv; 223 enum libbpf_map_type libbpf_type; 224 }; 225 226 struct bpf_secdata { 227 void *rodata; 228 void *data; 229 }; 230 231 static LIST_HEAD(bpf_objects_list); 232 233 struct bpf_object { 234 char name[BPF_OBJ_NAME_LEN]; 235 char license[64]; 236 __u32 kern_version; 237 238 struct bpf_program *programs; 239 size_t nr_programs; 240 struct bpf_map *maps; 241 size_t nr_maps; 242 size_t maps_cap; 243 struct bpf_secdata sections; 244 245 bool loaded; 246 bool has_pseudo_calls; 247 248 /* 249 * Information when doing elf related work. Only valid if fd 250 * is valid. 251 */ 252 struct { 253 int fd; 254 void *obj_buf; 255 size_t obj_buf_sz; 256 Elf *elf; 257 GElf_Ehdr ehdr; 258 Elf_Data *symbols; 259 Elf_Data *data; 260 Elf_Data *rodata; 261 Elf_Data *bss; 262 size_t strtabidx; 263 struct { 264 GElf_Shdr shdr; 265 Elf_Data *data; 266 } *reloc; 267 int nr_reloc; 268 int maps_shndx; 269 int btf_maps_shndx; 270 int text_shndx; 271 int data_shndx; 272 int rodata_shndx; 273 int bss_shndx; 274 } efile; 275 /* 276 * All loaded bpf_object is linked in a list, which is 277 * hidden to caller. bpf_objects__<func> handlers deal with 278 * all objects. 279 */ 280 struct list_head list; 281 282 struct btf *btf; 283 struct btf_ext *btf_ext; 284 285 void *priv; 286 bpf_object_clear_priv_t clear_priv; 287 288 struct bpf_capabilities caps; 289 290 char path[]; 291 }; 292 #define obj_elf_valid(o) ((o)->efile.elf) 293 294 void bpf_program__unload(struct bpf_program *prog) 295 { 296 int i; 297 298 if (!prog) 299 return; 300 301 /* 302 * If the object is opened but the program was never loaded, 303 * it is possible that prog->instances.nr == -1. 304 */ 305 if (prog->instances.nr > 0) { 306 for (i = 0; i < prog->instances.nr; i++) 307 zclose(prog->instances.fds[i]); 308 } else if (prog->instances.nr != -1) { 309 pr_warning("Internal error: instances.nr is %d\n", 310 prog->instances.nr); 311 } 312 313 prog->instances.nr = -1; 314 zfree(&prog->instances.fds); 315 316 zclose(prog->btf_fd); 317 zfree(&prog->func_info); 318 zfree(&prog->line_info); 319 } 320 321 static void bpf_program__exit(struct bpf_program *prog) 322 { 323 if (!prog) 324 return; 325 326 if (prog->clear_priv) 327 prog->clear_priv(prog, prog->priv); 328 329 prog->priv = NULL; 330 prog->clear_priv = NULL; 331 332 bpf_program__unload(prog); 333 zfree(&prog->name); 334 zfree(&prog->section_name); 335 zfree(&prog->pin_name); 336 zfree(&prog->insns); 337 zfree(&prog->reloc_desc); 338 339 prog->nr_reloc = 0; 340 prog->insns_cnt = 0; 341 prog->idx = -1; 342 } 343 344 static char *__bpf_program__pin_name(struct bpf_program *prog) 345 { 346 char *name, *p; 347 348 name = p = strdup(prog->section_name); 349 while ((p = strchr(p, '/'))) 350 *p = '_'; 351 352 return name; 353 } 354 355 static int 356 bpf_program__init(void *data, size_t size, char *section_name, int idx, 357 struct bpf_program *prog) 358 { 359 const size_t bpf_insn_sz = sizeof(struct bpf_insn); 360 361 if (size == 0 || size % bpf_insn_sz) { 362 pr_warning("corrupted section '%s', size: %zu\n", 363 section_name, size); 364 return -EINVAL; 365 } 366 367 memset(prog, 0, sizeof(*prog)); 368 369 prog->section_name = strdup(section_name); 370 if (!prog->section_name) { 371 pr_warning("failed to alloc name for prog under section(%d) %s\n", 372 idx, section_name); 373 goto errout; 374 } 375 376 prog->pin_name = __bpf_program__pin_name(prog); 377 if (!prog->pin_name) { 378 pr_warning("failed to alloc pin name for prog under section(%d) %s\n", 379 idx, section_name); 380 goto errout; 381 } 382 383 prog->insns = malloc(size); 384 if (!prog->insns) { 385 pr_warning("failed to alloc insns for prog under section %s\n", 386 section_name); 387 goto errout; 388 } 389 prog->insns_cnt = size / bpf_insn_sz; 390 memcpy(prog->insns, data, size); 391 prog->idx = idx; 392 prog->instances.fds = NULL; 393 prog->instances.nr = -1; 394 prog->type = BPF_PROG_TYPE_UNSPEC; 395 prog->btf_fd = -1; 396 397 return 0; 398 errout: 399 bpf_program__exit(prog); 400 return -ENOMEM; 401 } 402 403 static int 404 bpf_object__add_program(struct bpf_object *obj, void *data, size_t size, 405 char *section_name, int idx) 406 { 407 struct bpf_program prog, *progs; 408 int nr_progs, err; 409 410 err = bpf_program__init(data, size, section_name, idx, &prog); 411 if (err) 412 return err; 413 414 prog.caps = &obj->caps; 415 progs = obj->programs; 416 nr_progs = obj->nr_programs; 417 418 progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0])); 419 if (!progs) { 420 /* 421 * In this case the original obj->programs 422 * is still valid, so don't need special treat for 423 * bpf_close_object(). 424 */ 425 pr_warning("failed to alloc a new program under section '%s'\n", 426 section_name); 427 bpf_program__exit(&prog); 428 return -ENOMEM; 429 } 430 431 pr_debug("found program %s\n", prog.section_name); 432 obj->programs = progs; 433 obj->nr_programs = nr_progs + 1; 434 prog.obj = obj; 435 progs[nr_progs] = prog; 436 return 0; 437 } 438 439 static int 440 bpf_object__init_prog_names(struct bpf_object *obj) 441 { 442 Elf_Data *symbols = obj->efile.symbols; 443 struct bpf_program *prog; 444 size_t pi, si; 445 446 for (pi = 0; pi < obj->nr_programs; pi++) { 447 const char *name = NULL; 448 449 prog = &obj->programs[pi]; 450 451 for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name; 452 si++) { 453 GElf_Sym sym; 454 455 if (!gelf_getsym(symbols, si, &sym)) 456 continue; 457 if (sym.st_shndx != prog->idx) 458 continue; 459 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL) 460 continue; 461 462 name = elf_strptr(obj->efile.elf, 463 obj->efile.strtabidx, 464 sym.st_name); 465 if (!name) { 466 pr_warning("failed to get sym name string for prog %s\n", 467 prog->section_name); 468 return -LIBBPF_ERRNO__LIBELF; 469 } 470 } 471 472 if (!name && prog->idx == obj->efile.text_shndx) 473 name = ".text"; 474 475 if (!name) { 476 pr_warning("failed to find sym for prog %s\n", 477 prog->section_name); 478 return -EINVAL; 479 } 480 481 prog->name = strdup(name); 482 if (!prog->name) { 483 pr_warning("failed to allocate memory for prog sym %s\n", 484 name); 485 return -ENOMEM; 486 } 487 } 488 489 return 0; 490 } 491 492 static struct bpf_object *bpf_object__new(const char *path, 493 void *obj_buf, 494 size_t obj_buf_sz) 495 { 496 struct bpf_object *obj; 497 char *end; 498 499 obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1); 500 if (!obj) { 501 pr_warning("alloc memory failed for %s\n", path); 502 return ERR_PTR(-ENOMEM); 503 } 504 505 strcpy(obj->path, path); 506 /* Using basename() GNU version which doesn't modify arg. */ 507 strncpy(obj->name, basename((void *)path), sizeof(obj->name) - 1); 508 end = strchr(obj->name, '.'); 509 if (end) 510 *end = 0; 511 512 obj->efile.fd = -1; 513 /* 514 * Caller of this function should also call 515 * bpf_object__elf_finish() after data collection to return 516 * obj_buf to user. If not, we should duplicate the buffer to 517 * avoid user freeing them before elf finish. 518 */ 519 obj->efile.obj_buf = obj_buf; 520 obj->efile.obj_buf_sz = obj_buf_sz; 521 obj->efile.maps_shndx = -1; 522 obj->efile.btf_maps_shndx = -1; 523 obj->efile.data_shndx = -1; 524 obj->efile.rodata_shndx = -1; 525 obj->efile.bss_shndx = -1; 526 527 obj->loaded = false; 528 529 INIT_LIST_HEAD(&obj->list); 530 list_add(&obj->list, &bpf_objects_list); 531 return obj; 532 } 533 534 static void bpf_object__elf_finish(struct bpf_object *obj) 535 { 536 if (!obj_elf_valid(obj)) 537 return; 538 539 if (obj->efile.elf) { 540 elf_end(obj->efile.elf); 541 obj->efile.elf = NULL; 542 } 543 obj->efile.symbols = NULL; 544 obj->efile.data = NULL; 545 obj->efile.rodata = NULL; 546 obj->efile.bss = NULL; 547 548 zfree(&obj->efile.reloc); 549 obj->efile.nr_reloc = 0; 550 zclose(obj->efile.fd); 551 obj->efile.obj_buf = NULL; 552 obj->efile.obj_buf_sz = 0; 553 } 554 555 static int bpf_object__elf_init(struct bpf_object *obj) 556 { 557 int err = 0; 558 GElf_Ehdr *ep; 559 560 if (obj_elf_valid(obj)) { 561 pr_warning("elf init: internal error\n"); 562 return -LIBBPF_ERRNO__LIBELF; 563 } 564 565 if (obj->efile.obj_buf_sz > 0) { 566 /* 567 * obj_buf should have been validated by 568 * bpf_object__open_buffer(). 569 */ 570 obj->efile.elf = elf_memory(obj->efile.obj_buf, 571 obj->efile.obj_buf_sz); 572 } else { 573 obj->efile.fd = open(obj->path, O_RDONLY); 574 if (obj->efile.fd < 0) { 575 char errmsg[STRERR_BUFSIZE], *cp; 576 577 err = -errno; 578 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); 579 pr_warning("failed to open %s: %s\n", obj->path, cp); 580 return err; 581 } 582 583 obj->efile.elf = elf_begin(obj->efile.fd, 584 LIBBPF_ELF_C_READ_MMAP, NULL); 585 } 586 587 if (!obj->efile.elf) { 588 pr_warning("failed to open %s as ELF file\n", obj->path); 589 err = -LIBBPF_ERRNO__LIBELF; 590 goto errout; 591 } 592 593 if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) { 594 pr_warning("failed to get EHDR from %s\n", obj->path); 595 err = -LIBBPF_ERRNO__FORMAT; 596 goto errout; 597 } 598 ep = &obj->efile.ehdr; 599 600 /* Old LLVM set e_machine to EM_NONE */ 601 if (ep->e_type != ET_REL || 602 (ep->e_machine && ep->e_machine != EM_BPF)) { 603 pr_warning("%s is not an eBPF object file\n", obj->path); 604 err = -LIBBPF_ERRNO__FORMAT; 605 goto errout; 606 } 607 608 return 0; 609 errout: 610 bpf_object__elf_finish(obj); 611 return err; 612 } 613 614 static int bpf_object__check_endianness(struct bpf_object *obj) 615 { 616 #if __BYTE_ORDER == __LITTLE_ENDIAN 617 if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB) 618 return 0; 619 #elif __BYTE_ORDER == __BIG_ENDIAN 620 if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB) 621 return 0; 622 #else 623 # error "Unrecognized __BYTE_ORDER__" 624 #endif 625 pr_warning("endianness mismatch.\n"); 626 return -LIBBPF_ERRNO__ENDIAN; 627 } 628 629 static int 630 bpf_object__init_license(struct bpf_object *obj, void *data, size_t size) 631 { 632 memcpy(obj->license, data, min(size, sizeof(obj->license) - 1)); 633 pr_debug("license of %s is %s\n", obj->path, obj->license); 634 return 0; 635 } 636 637 static int 638 bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size) 639 { 640 __u32 kver; 641 642 if (size != sizeof(kver)) { 643 pr_warning("invalid kver section in %s\n", obj->path); 644 return -LIBBPF_ERRNO__FORMAT; 645 } 646 memcpy(&kver, data, sizeof(kver)); 647 obj->kern_version = kver; 648 pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version); 649 return 0; 650 } 651 652 static int compare_bpf_map(const void *_a, const void *_b) 653 { 654 const struct bpf_map *a = _a; 655 const struct bpf_map *b = _b; 656 657 if (a->sec_idx != b->sec_idx) 658 return a->sec_idx - b->sec_idx; 659 return a->sec_offset - b->sec_offset; 660 } 661 662 static bool bpf_map_type__is_map_in_map(enum bpf_map_type type) 663 { 664 if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS || 665 type == BPF_MAP_TYPE_HASH_OF_MAPS) 666 return true; 667 return false; 668 } 669 670 static int bpf_object_search_section_size(const struct bpf_object *obj, 671 const char *name, size_t *d_size) 672 { 673 const GElf_Ehdr *ep = &obj->efile.ehdr; 674 Elf *elf = obj->efile.elf; 675 Elf_Scn *scn = NULL; 676 int idx = 0; 677 678 while ((scn = elf_nextscn(elf, scn)) != NULL) { 679 const char *sec_name; 680 Elf_Data *data; 681 GElf_Shdr sh; 682 683 idx++; 684 if (gelf_getshdr(scn, &sh) != &sh) { 685 pr_warning("failed to get section(%d) header from %s\n", 686 idx, obj->path); 687 return -EIO; 688 } 689 690 sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); 691 if (!sec_name) { 692 pr_warning("failed to get section(%d) name from %s\n", 693 idx, obj->path); 694 return -EIO; 695 } 696 697 if (strcmp(name, sec_name)) 698 continue; 699 700 data = elf_getdata(scn, 0); 701 if (!data) { 702 pr_warning("failed to get section(%d) data from %s(%s)\n", 703 idx, name, obj->path); 704 return -EIO; 705 } 706 707 *d_size = data->d_size; 708 return 0; 709 } 710 711 return -ENOENT; 712 } 713 714 int bpf_object__section_size(const struct bpf_object *obj, const char *name, 715 __u32 *size) 716 { 717 int ret = -ENOENT; 718 size_t d_size; 719 720 *size = 0; 721 if (!name) { 722 return -EINVAL; 723 } else if (!strcmp(name, ".data")) { 724 if (obj->efile.data) 725 *size = obj->efile.data->d_size; 726 } else if (!strcmp(name, ".bss")) { 727 if (obj->efile.bss) 728 *size = obj->efile.bss->d_size; 729 } else if (!strcmp(name, ".rodata")) { 730 if (obj->efile.rodata) 731 *size = obj->efile.rodata->d_size; 732 } else { 733 ret = bpf_object_search_section_size(obj, name, &d_size); 734 if (!ret) 735 *size = d_size; 736 } 737 738 return *size ? 0 : ret; 739 } 740 741 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, 742 __u32 *off) 743 { 744 Elf_Data *symbols = obj->efile.symbols; 745 const char *sname; 746 size_t si; 747 748 if (!name || !off) 749 return -EINVAL; 750 751 for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) { 752 GElf_Sym sym; 753 754 if (!gelf_getsym(symbols, si, &sym)) 755 continue; 756 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL || 757 GELF_ST_TYPE(sym.st_info) != STT_OBJECT) 758 continue; 759 760 sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx, 761 sym.st_name); 762 if (!sname) { 763 pr_warning("failed to get sym name string for var %s\n", 764 name); 765 return -EIO; 766 } 767 if (strcmp(name, sname) == 0) { 768 *off = sym.st_value; 769 return 0; 770 } 771 } 772 773 return -ENOENT; 774 } 775 776 static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) 777 { 778 struct bpf_map *new_maps; 779 size_t new_cap; 780 int i; 781 782 if (obj->nr_maps < obj->maps_cap) 783 return &obj->maps[obj->nr_maps++]; 784 785 new_cap = max((size_t)4, obj->maps_cap * 3 / 2); 786 new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps)); 787 if (!new_maps) { 788 pr_warning("alloc maps for object failed\n"); 789 return ERR_PTR(-ENOMEM); 790 } 791 792 obj->maps_cap = new_cap; 793 obj->maps = new_maps; 794 795 /* zero out new maps */ 796 memset(obj->maps + obj->nr_maps, 0, 797 (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps)); 798 /* 799 * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin) 800 * when failure (zclose won't close negative fd)). 801 */ 802 for (i = obj->nr_maps; i < obj->maps_cap; i++) { 803 obj->maps[i].fd = -1; 804 obj->maps[i].inner_map_fd = -1; 805 } 806 807 return &obj->maps[obj->nr_maps++]; 808 } 809 810 static int 811 bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, 812 int sec_idx, Elf_Data *data, void **data_buff) 813 { 814 char map_name[BPF_OBJ_NAME_LEN]; 815 struct bpf_map_def *def; 816 struct bpf_map *map; 817 818 map = bpf_object__add_map(obj); 819 if (IS_ERR(map)) 820 return PTR_ERR(map); 821 822 map->libbpf_type = type; 823 map->sec_idx = sec_idx; 824 map->sec_offset = 0; 825 snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name, 826 libbpf_type_to_btf_name[type]); 827 map->name = strdup(map_name); 828 if (!map->name) { 829 pr_warning("failed to alloc map name\n"); 830 return -ENOMEM; 831 } 832 pr_debug("map '%s' (global data): at sec_idx %d, offset %zu.\n", 833 map_name, map->sec_idx, map->sec_offset); 834 835 def = &map->def; 836 def->type = BPF_MAP_TYPE_ARRAY; 837 def->key_size = sizeof(int); 838 def->value_size = data->d_size; 839 def->max_entries = 1; 840 def->map_flags = type == LIBBPF_MAP_RODATA ? BPF_F_RDONLY_PROG : 0; 841 if (data_buff) { 842 *data_buff = malloc(data->d_size); 843 if (!*data_buff) { 844 zfree(&map->name); 845 pr_warning("failed to alloc map content buffer\n"); 846 return -ENOMEM; 847 } 848 memcpy(*data_buff, data->d_buf, data->d_size); 849 } 850 851 pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name); 852 return 0; 853 } 854 855 static int bpf_object__init_global_data_maps(struct bpf_object *obj) 856 { 857 int err; 858 859 if (!obj->caps.global_data) 860 return 0; 861 /* 862 * Populate obj->maps with libbpf internal maps. 863 */ 864 if (obj->efile.data_shndx >= 0) { 865 err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA, 866 obj->efile.data_shndx, 867 obj->efile.data, 868 &obj->sections.data); 869 if (err) 870 return err; 871 } 872 if (obj->efile.rodata_shndx >= 0) { 873 err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA, 874 obj->efile.rodata_shndx, 875 obj->efile.rodata, 876 &obj->sections.rodata); 877 if (err) 878 return err; 879 } 880 if (obj->efile.bss_shndx >= 0) { 881 err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS, 882 obj->efile.bss_shndx, 883 obj->efile.bss, NULL); 884 if (err) 885 return err; 886 } 887 return 0; 888 } 889 890 static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) 891 { 892 Elf_Data *symbols = obj->efile.symbols; 893 int i, map_def_sz = 0, nr_maps = 0, nr_syms; 894 Elf_Data *data = NULL; 895 Elf_Scn *scn; 896 897 if (obj->efile.maps_shndx < 0) 898 return 0; 899 900 if (!symbols) 901 return -EINVAL; 902 903 scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); 904 if (scn) 905 data = elf_getdata(scn, NULL); 906 if (!scn || !data) { 907 pr_warning("failed to get Elf_Data from map section %d\n", 908 obj->efile.maps_shndx); 909 return -EINVAL; 910 } 911 912 /* 913 * Count number of maps. Each map has a name. 914 * Array of maps is not supported: only the first element is 915 * considered. 916 * 917 * TODO: Detect array of map and report error. 918 */ 919 nr_syms = symbols->d_size / sizeof(GElf_Sym); 920 for (i = 0; i < nr_syms; i++) { 921 GElf_Sym sym; 922 923 if (!gelf_getsym(symbols, i, &sym)) 924 continue; 925 if (sym.st_shndx != obj->efile.maps_shndx) 926 continue; 927 nr_maps++; 928 } 929 /* Assume equally sized map definitions */ 930 pr_debug("maps in %s: %d maps in %zd bytes\n", 931 obj->path, nr_maps, data->d_size); 932 933 map_def_sz = data->d_size / nr_maps; 934 if (!data->d_size || (data->d_size % nr_maps) != 0) { 935 pr_warning("unable to determine map definition size " 936 "section %s, %d maps in %zd bytes\n", 937 obj->path, nr_maps, data->d_size); 938 return -EINVAL; 939 } 940 941 /* Fill obj->maps using data in "maps" section. */ 942 for (i = 0; i < nr_syms; i++) { 943 GElf_Sym sym; 944 const char *map_name; 945 struct bpf_map_def *def; 946 struct bpf_map *map; 947 948 if (!gelf_getsym(symbols, i, &sym)) 949 continue; 950 if (sym.st_shndx != obj->efile.maps_shndx) 951 continue; 952 953 map = bpf_object__add_map(obj); 954 if (IS_ERR(map)) 955 return PTR_ERR(map); 956 957 map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, 958 sym.st_name); 959 if (!map_name) { 960 pr_warning("failed to get map #%d name sym string for obj %s\n", 961 i, obj->path); 962 return -LIBBPF_ERRNO__FORMAT; 963 } 964 965 map->libbpf_type = LIBBPF_MAP_UNSPEC; 966 map->sec_idx = sym.st_shndx; 967 map->sec_offset = sym.st_value; 968 pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n", 969 map_name, map->sec_idx, map->sec_offset); 970 if (sym.st_value + map_def_sz > data->d_size) { 971 pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", 972 obj->path, map_name); 973 return -EINVAL; 974 } 975 976 map->name = strdup(map_name); 977 if (!map->name) { 978 pr_warning("failed to alloc map name\n"); 979 return -ENOMEM; 980 } 981 pr_debug("map %d is \"%s\"\n", i, map->name); 982 def = (struct bpf_map_def *)(data->d_buf + sym.st_value); 983 /* 984 * If the definition of the map in the object file fits in 985 * bpf_map_def, copy it. Any extra fields in our version 986 * of bpf_map_def will default to zero as a result of the 987 * calloc above. 988 */ 989 if (map_def_sz <= sizeof(struct bpf_map_def)) { 990 memcpy(&map->def, def, map_def_sz); 991 } else { 992 /* 993 * Here the map structure being read is bigger than what 994 * we expect, truncate if the excess bits are all zero. 995 * If they are not zero, reject this map as 996 * incompatible. 997 */ 998 char *b; 999 for (b = ((char *)def) + sizeof(struct bpf_map_def); 1000 b < ((char *)def) + map_def_sz; b++) { 1001 if (*b != 0) { 1002 pr_warning("maps section in %s: \"%s\" " 1003 "has unrecognized, non-zero " 1004 "options\n", 1005 obj->path, map_name); 1006 if (strict) 1007 return -EINVAL; 1008 } 1009 } 1010 memcpy(&map->def, def, sizeof(struct bpf_map_def)); 1011 } 1012 } 1013 return 0; 1014 } 1015 1016 static const struct btf_type *skip_mods_and_typedefs(const struct btf *btf, 1017 __u32 id) 1018 { 1019 const struct btf_type *t = btf__type_by_id(btf, id); 1020 1021 while (true) { 1022 switch (BTF_INFO_KIND(t->info)) { 1023 case BTF_KIND_VOLATILE: 1024 case BTF_KIND_CONST: 1025 case BTF_KIND_RESTRICT: 1026 case BTF_KIND_TYPEDEF: 1027 t = btf__type_by_id(btf, t->type); 1028 break; 1029 default: 1030 return t; 1031 } 1032 } 1033 } 1034 1035 /* 1036 * Fetch integer attribute of BTF map definition. Such attributes are 1037 * represented using a pointer to an array, in which dimensionality of array 1038 * encodes specified integer value. E.g., int (*type)[BPF_MAP_TYPE_ARRAY]; 1039 * encodes `type => BPF_MAP_TYPE_ARRAY` key/value pair completely using BTF 1040 * type definition, while using only sizeof(void *) space in ELF data section. 1041 */ 1042 static bool get_map_field_int(const char *map_name, const struct btf *btf, 1043 const struct btf_type *def, 1044 const struct btf_member *m, __u32 *res) { 1045 const struct btf_type *t = skip_mods_and_typedefs(btf, m->type); 1046 const char *name = btf__name_by_offset(btf, m->name_off); 1047 const struct btf_array *arr_info; 1048 const struct btf_type *arr_t; 1049 1050 if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { 1051 pr_warning("map '%s': attr '%s': expected PTR, got %u.\n", 1052 map_name, name, BTF_INFO_KIND(t->info)); 1053 return false; 1054 } 1055 1056 arr_t = btf__type_by_id(btf, t->type); 1057 if (!arr_t) { 1058 pr_warning("map '%s': attr '%s': type [%u] not found.\n", 1059 map_name, name, t->type); 1060 return false; 1061 } 1062 if (BTF_INFO_KIND(arr_t->info) != BTF_KIND_ARRAY) { 1063 pr_warning("map '%s': attr '%s': expected ARRAY, got %u.\n", 1064 map_name, name, BTF_INFO_KIND(arr_t->info)); 1065 return false; 1066 } 1067 arr_info = (const void *)(arr_t + 1); 1068 *res = arr_info->nelems; 1069 return true; 1070 } 1071 1072 static int bpf_object__init_user_btf_map(struct bpf_object *obj, 1073 const struct btf_type *sec, 1074 int var_idx, int sec_idx, 1075 const Elf_Data *data, bool strict) 1076 { 1077 const struct btf_type *var, *def, *t; 1078 const struct btf_var_secinfo *vi; 1079 const struct btf_var *var_extra; 1080 const struct btf_member *m; 1081 const char *map_name; 1082 struct bpf_map *map; 1083 int vlen, i; 1084 1085 vi = (const struct btf_var_secinfo *)(const void *)(sec + 1) + var_idx; 1086 var = btf__type_by_id(obj->btf, vi->type); 1087 var_extra = (const void *)(var + 1); 1088 map_name = btf__name_by_offset(obj->btf, var->name_off); 1089 vlen = BTF_INFO_VLEN(var->info); 1090 1091 if (map_name == NULL || map_name[0] == '\0') { 1092 pr_warning("map #%d: empty name.\n", var_idx); 1093 return -EINVAL; 1094 } 1095 if ((__u64)vi->offset + vi->size > data->d_size) { 1096 pr_warning("map '%s' BTF data is corrupted.\n", map_name); 1097 return -EINVAL; 1098 } 1099 if (BTF_INFO_KIND(var->info) != BTF_KIND_VAR) { 1100 pr_warning("map '%s': unexpected var kind %u.\n", 1101 map_name, BTF_INFO_KIND(var->info)); 1102 return -EINVAL; 1103 } 1104 if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED && 1105 var_extra->linkage != BTF_VAR_STATIC) { 1106 pr_warning("map '%s': unsupported var linkage %u.\n", 1107 map_name, var_extra->linkage); 1108 return -EOPNOTSUPP; 1109 } 1110 1111 def = skip_mods_and_typedefs(obj->btf, var->type); 1112 if (BTF_INFO_KIND(def->info) != BTF_KIND_STRUCT) { 1113 pr_warning("map '%s': unexpected def kind %u.\n", 1114 map_name, BTF_INFO_KIND(var->info)); 1115 return -EINVAL; 1116 } 1117 if (def->size > vi->size) { 1118 pr_warning("map '%s': invalid def size.\n", map_name); 1119 return -EINVAL; 1120 } 1121 1122 map = bpf_object__add_map(obj); 1123 if (IS_ERR(map)) 1124 return PTR_ERR(map); 1125 map->name = strdup(map_name); 1126 if (!map->name) { 1127 pr_warning("map '%s': failed to alloc map name.\n", map_name); 1128 return -ENOMEM; 1129 } 1130 map->libbpf_type = LIBBPF_MAP_UNSPEC; 1131 map->def.type = BPF_MAP_TYPE_UNSPEC; 1132 map->sec_idx = sec_idx; 1133 map->sec_offset = vi->offset; 1134 pr_debug("map '%s': at sec_idx %d, offset %zu.\n", 1135 map_name, map->sec_idx, map->sec_offset); 1136 1137 vlen = BTF_INFO_VLEN(def->info); 1138 m = (const void *)(def + 1); 1139 for (i = 0; i < vlen; i++, m++) { 1140 const char *name = btf__name_by_offset(obj->btf, m->name_off); 1141 1142 if (!name) { 1143 pr_warning("map '%s': invalid field #%d.\n", 1144 map_name, i); 1145 return -EINVAL; 1146 } 1147 if (strcmp(name, "type") == 0) { 1148 if (!get_map_field_int(map_name, obj->btf, def, m, 1149 &map->def.type)) 1150 return -EINVAL; 1151 pr_debug("map '%s': found type = %u.\n", 1152 map_name, map->def.type); 1153 } else if (strcmp(name, "max_entries") == 0) { 1154 if (!get_map_field_int(map_name, obj->btf, def, m, 1155 &map->def.max_entries)) 1156 return -EINVAL; 1157 pr_debug("map '%s': found max_entries = %u.\n", 1158 map_name, map->def.max_entries); 1159 } else if (strcmp(name, "map_flags") == 0) { 1160 if (!get_map_field_int(map_name, obj->btf, def, m, 1161 &map->def.map_flags)) 1162 return -EINVAL; 1163 pr_debug("map '%s': found map_flags = %u.\n", 1164 map_name, map->def.map_flags); 1165 } else if (strcmp(name, "key_size") == 0) { 1166 __u32 sz; 1167 1168 if (!get_map_field_int(map_name, obj->btf, def, m, 1169 &sz)) 1170 return -EINVAL; 1171 pr_debug("map '%s': found key_size = %u.\n", 1172 map_name, sz); 1173 if (map->def.key_size && map->def.key_size != sz) { 1174 pr_warning("map '%s': conflicting key size %u != %u.\n", 1175 map_name, map->def.key_size, sz); 1176 return -EINVAL; 1177 } 1178 map->def.key_size = sz; 1179 } else if (strcmp(name, "key") == 0) { 1180 __s64 sz; 1181 1182 t = btf__type_by_id(obj->btf, m->type); 1183 if (!t) { 1184 pr_warning("map '%s': key type [%d] not found.\n", 1185 map_name, m->type); 1186 return -EINVAL; 1187 } 1188 if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { 1189 pr_warning("map '%s': key spec is not PTR: %u.\n", 1190 map_name, BTF_INFO_KIND(t->info)); 1191 return -EINVAL; 1192 } 1193 sz = btf__resolve_size(obj->btf, t->type); 1194 if (sz < 0) { 1195 pr_warning("map '%s': can't determine key size for type [%u]: %lld.\n", 1196 map_name, t->type, sz); 1197 return sz; 1198 } 1199 pr_debug("map '%s': found key [%u], sz = %lld.\n", 1200 map_name, t->type, sz); 1201 if (map->def.key_size && map->def.key_size != sz) { 1202 pr_warning("map '%s': conflicting key size %u != %lld.\n", 1203 map_name, map->def.key_size, sz); 1204 return -EINVAL; 1205 } 1206 map->def.key_size = sz; 1207 map->btf_key_type_id = t->type; 1208 } else if (strcmp(name, "value_size") == 0) { 1209 __u32 sz; 1210 1211 if (!get_map_field_int(map_name, obj->btf, def, m, 1212 &sz)) 1213 return -EINVAL; 1214 pr_debug("map '%s': found value_size = %u.\n", 1215 map_name, sz); 1216 if (map->def.value_size && map->def.value_size != sz) { 1217 pr_warning("map '%s': conflicting value size %u != %u.\n", 1218 map_name, map->def.value_size, sz); 1219 return -EINVAL; 1220 } 1221 map->def.value_size = sz; 1222 } else if (strcmp(name, "value") == 0) { 1223 __s64 sz; 1224 1225 t = btf__type_by_id(obj->btf, m->type); 1226 if (!t) { 1227 pr_warning("map '%s': value type [%d] not found.\n", 1228 map_name, m->type); 1229 return -EINVAL; 1230 } 1231 if (BTF_INFO_KIND(t->info) != BTF_KIND_PTR) { 1232 pr_warning("map '%s': value spec is not PTR: %u.\n", 1233 map_name, BTF_INFO_KIND(t->info)); 1234 return -EINVAL; 1235 } 1236 sz = btf__resolve_size(obj->btf, t->type); 1237 if (sz < 0) { 1238 pr_warning("map '%s': can't determine value size for type [%u]: %lld.\n", 1239 map_name, t->type, sz); 1240 return sz; 1241 } 1242 pr_debug("map '%s': found value [%u], sz = %lld.\n", 1243 map_name, t->type, sz); 1244 if (map->def.value_size && map->def.value_size != sz) { 1245 pr_warning("map '%s': conflicting value size %u != %lld.\n", 1246 map_name, map->def.value_size, sz); 1247 return -EINVAL; 1248 } 1249 map->def.value_size = sz; 1250 map->btf_value_type_id = t->type; 1251 } else { 1252 if (strict) { 1253 pr_warning("map '%s': unknown field '%s'.\n", 1254 map_name, name); 1255 return -ENOTSUP; 1256 } 1257 pr_debug("map '%s': ignoring unknown field '%s'.\n", 1258 map_name, name); 1259 } 1260 } 1261 1262 if (map->def.type == BPF_MAP_TYPE_UNSPEC) { 1263 pr_warning("map '%s': map type isn't specified.\n", map_name); 1264 return -EINVAL; 1265 } 1266 1267 return 0; 1268 } 1269 1270 static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict) 1271 { 1272 const struct btf_type *sec = NULL; 1273 int nr_types, i, vlen, err; 1274 const struct btf_type *t; 1275 const char *name; 1276 Elf_Data *data; 1277 Elf_Scn *scn; 1278 1279 if (obj->efile.btf_maps_shndx < 0) 1280 return 0; 1281 1282 scn = elf_getscn(obj->efile.elf, obj->efile.btf_maps_shndx); 1283 if (scn) 1284 data = elf_getdata(scn, NULL); 1285 if (!scn || !data) { 1286 pr_warning("failed to get Elf_Data from map section %d (%s)\n", 1287 obj->efile.maps_shndx, MAPS_ELF_SEC); 1288 return -EINVAL; 1289 } 1290 1291 nr_types = btf__get_nr_types(obj->btf); 1292 for (i = 1; i <= nr_types; i++) { 1293 t = btf__type_by_id(obj->btf, i); 1294 if (BTF_INFO_KIND(t->info) != BTF_KIND_DATASEC) 1295 continue; 1296 name = btf__name_by_offset(obj->btf, t->name_off); 1297 if (strcmp(name, MAPS_ELF_SEC) == 0) { 1298 sec = t; 1299 break; 1300 } 1301 } 1302 1303 if (!sec) { 1304 pr_warning("DATASEC '%s' not found.\n", MAPS_ELF_SEC); 1305 return -ENOENT; 1306 } 1307 1308 vlen = BTF_INFO_VLEN(sec->info); 1309 for (i = 0; i < vlen; i++) { 1310 err = bpf_object__init_user_btf_map(obj, sec, i, 1311 obj->efile.btf_maps_shndx, 1312 data, strict); 1313 if (err) 1314 return err; 1315 } 1316 1317 return 0; 1318 } 1319 1320 static int bpf_object__init_maps(struct bpf_object *obj, int flags) 1321 { 1322 bool strict = !(flags & MAPS_RELAX_COMPAT); 1323 int err; 1324 1325 err = bpf_object__init_user_maps(obj, strict); 1326 if (err) 1327 return err; 1328 1329 err = bpf_object__init_user_btf_maps(obj, strict); 1330 if (err) 1331 return err; 1332 1333 err = bpf_object__init_global_data_maps(obj); 1334 if (err) 1335 return err; 1336 1337 if (obj->nr_maps) { 1338 qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), 1339 compare_bpf_map); 1340 } 1341 return 0; 1342 } 1343 1344 static bool section_have_execinstr(struct bpf_object *obj, int idx) 1345 { 1346 Elf_Scn *scn; 1347 GElf_Shdr sh; 1348 1349 scn = elf_getscn(obj->efile.elf, idx); 1350 if (!scn) 1351 return false; 1352 1353 if (gelf_getshdr(scn, &sh) != &sh) 1354 return false; 1355 1356 if (sh.sh_flags & SHF_EXECINSTR) 1357 return true; 1358 1359 return false; 1360 } 1361 1362 static void bpf_object__sanitize_btf(struct bpf_object *obj) 1363 { 1364 bool has_datasec = obj->caps.btf_datasec; 1365 bool has_func = obj->caps.btf_func; 1366 struct btf *btf = obj->btf; 1367 struct btf_type *t; 1368 int i, j, vlen; 1369 __u16 kind; 1370 1371 if (!obj->btf || (has_func && has_datasec)) 1372 return; 1373 1374 for (i = 1; i <= btf__get_nr_types(btf); i++) { 1375 t = (struct btf_type *)btf__type_by_id(btf, i); 1376 kind = BTF_INFO_KIND(t->info); 1377 1378 if (!has_datasec && kind == BTF_KIND_VAR) { 1379 /* replace VAR with INT */ 1380 t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0); 1381 /* 1382 * using size = 1 is the safest choice, 4 will be too 1383 * big and cause kernel BTF validation failure if 1384 * original variable took less than 4 bytes 1385 */ 1386 t->size = 1; 1387 *(int *)(t+1) = BTF_INT_ENC(0, 0, 8); 1388 } else if (!has_datasec && kind == BTF_KIND_DATASEC) { 1389 /* replace DATASEC with STRUCT */ 1390 struct btf_var_secinfo *v = (void *)(t + 1); 1391 struct btf_member *m = (void *)(t + 1); 1392 struct btf_type *vt; 1393 char *name; 1394 1395 name = (char *)btf__name_by_offset(btf, t->name_off); 1396 while (*name) { 1397 if (*name == '.') 1398 *name = '_'; 1399 name++; 1400 } 1401 1402 vlen = BTF_INFO_VLEN(t->info); 1403 t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, vlen); 1404 for (j = 0; j < vlen; j++, v++, m++) { 1405 /* order of field assignments is important */ 1406 m->offset = v->offset * 8; 1407 m->type = v->type; 1408 /* preserve variable name as member name */ 1409 vt = (void *)btf__type_by_id(btf, v->type); 1410 m->name_off = vt->name_off; 1411 } 1412 } else if (!has_func && kind == BTF_KIND_FUNC_PROTO) { 1413 /* replace FUNC_PROTO with ENUM */ 1414 vlen = BTF_INFO_VLEN(t->info); 1415 t->info = BTF_INFO_ENC(BTF_KIND_ENUM, 0, vlen); 1416 t->size = sizeof(__u32); /* kernel enforced */ 1417 } else if (!has_func && kind == BTF_KIND_FUNC) { 1418 /* replace FUNC with TYPEDEF */ 1419 t->info = BTF_INFO_ENC(BTF_KIND_TYPEDEF, 0, 0); 1420 } 1421 } 1422 } 1423 1424 static void bpf_object__sanitize_btf_ext(struct bpf_object *obj) 1425 { 1426 if (!obj->btf_ext) 1427 return; 1428 1429 if (!obj->caps.btf_func) { 1430 btf_ext__free(obj->btf_ext); 1431 obj->btf_ext = NULL; 1432 } 1433 } 1434 1435 static bool bpf_object__is_btf_mandatory(const struct bpf_object *obj) 1436 { 1437 return obj->efile.btf_maps_shndx >= 0; 1438 } 1439 1440 static int bpf_object__init_btf(struct bpf_object *obj, 1441 Elf_Data *btf_data, 1442 Elf_Data *btf_ext_data) 1443 { 1444 bool btf_required = bpf_object__is_btf_mandatory(obj); 1445 int err = 0; 1446 1447 if (btf_data) { 1448 obj->btf = btf__new(btf_data->d_buf, btf_data->d_size); 1449 if (IS_ERR(obj->btf)) { 1450 pr_warning("Error loading ELF section %s: %d.\n", 1451 BTF_ELF_SEC, err); 1452 goto out; 1453 } 1454 err = btf__finalize_data(obj, obj->btf); 1455 if (err) { 1456 pr_warning("Error finalizing %s: %d.\n", 1457 BTF_ELF_SEC, err); 1458 goto out; 1459 } 1460 } 1461 if (btf_ext_data) { 1462 if (!obj->btf) { 1463 pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", 1464 BTF_EXT_ELF_SEC, BTF_ELF_SEC); 1465 goto out; 1466 } 1467 obj->btf_ext = btf_ext__new(btf_ext_data->d_buf, 1468 btf_ext_data->d_size); 1469 if (IS_ERR(obj->btf_ext)) { 1470 pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", 1471 BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext)); 1472 obj->btf_ext = NULL; 1473 goto out; 1474 } 1475 } 1476 out: 1477 if (err || IS_ERR(obj->btf)) { 1478 if (btf_required) 1479 err = err ? : PTR_ERR(obj->btf); 1480 else 1481 err = 0; 1482 if (!IS_ERR_OR_NULL(obj->btf)) 1483 btf__free(obj->btf); 1484 obj->btf = NULL; 1485 } 1486 if (btf_required && !obj->btf) { 1487 pr_warning("BTF is required, but is missing or corrupted.\n"); 1488 return err == 0 ? -ENOENT : err; 1489 } 1490 return 0; 1491 } 1492 1493 static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) 1494 { 1495 int err = 0; 1496 1497 if (!obj->btf) 1498 return 0; 1499 1500 bpf_object__sanitize_btf(obj); 1501 bpf_object__sanitize_btf_ext(obj); 1502 1503 err = btf__load(obj->btf); 1504 if (err) { 1505 pr_warning("Error loading %s into kernel: %d.\n", 1506 BTF_ELF_SEC, err); 1507 btf__free(obj->btf); 1508 obj->btf = NULL; 1509 /* btf_ext can't exist without btf, so free it as well */ 1510 if (obj->btf_ext) { 1511 btf_ext__free(obj->btf_ext); 1512 obj->btf_ext = NULL; 1513 } 1514 1515 if (bpf_object__is_btf_mandatory(obj)) 1516 return err; 1517 } 1518 return 0; 1519 } 1520 1521 static int bpf_object__elf_collect(struct bpf_object *obj, int flags) 1522 { 1523 Elf *elf = obj->efile.elf; 1524 GElf_Ehdr *ep = &obj->efile.ehdr; 1525 Elf_Data *btf_ext_data = NULL; 1526 Elf_Data *btf_data = NULL; 1527 Elf_Scn *scn = NULL; 1528 int idx = 0, err = 0; 1529 1530 /* Elf is corrupted/truncated, avoid calling elf_strptr. */ 1531 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) { 1532 pr_warning("failed to get e_shstrndx from %s\n", obj->path); 1533 return -LIBBPF_ERRNO__FORMAT; 1534 } 1535 1536 while ((scn = elf_nextscn(elf, scn)) != NULL) { 1537 char *name; 1538 GElf_Shdr sh; 1539 Elf_Data *data; 1540 1541 idx++; 1542 if (gelf_getshdr(scn, &sh) != &sh) { 1543 pr_warning("failed to get section(%d) header from %s\n", 1544 idx, obj->path); 1545 return -LIBBPF_ERRNO__FORMAT; 1546 } 1547 1548 name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); 1549 if (!name) { 1550 pr_warning("failed to get section(%d) name from %s\n", 1551 idx, obj->path); 1552 return -LIBBPF_ERRNO__FORMAT; 1553 } 1554 1555 data = elf_getdata(scn, 0); 1556 if (!data) { 1557 pr_warning("failed to get section(%d) data from %s(%s)\n", 1558 idx, name, obj->path); 1559 return -LIBBPF_ERRNO__FORMAT; 1560 } 1561 pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", 1562 idx, name, (unsigned long)data->d_size, 1563 (int)sh.sh_link, (unsigned long)sh.sh_flags, 1564 (int)sh.sh_type); 1565 1566 if (strcmp(name, "license") == 0) { 1567 err = bpf_object__init_license(obj, 1568 data->d_buf, 1569 data->d_size); 1570 if (err) 1571 return err; 1572 } else if (strcmp(name, "version") == 0) { 1573 err = bpf_object__init_kversion(obj, 1574 data->d_buf, 1575 data->d_size); 1576 if (err) 1577 return err; 1578 } else if (strcmp(name, "maps") == 0) { 1579 obj->efile.maps_shndx = idx; 1580 } else if (strcmp(name, MAPS_ELF_SEC) == 0) { 1581 obj->efile.btf_maps_shndx = idx; 1582 } else if (strcmp(name, BTF_ELF_SEC) == 0) { 1583 btf_data = data; 1584 } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) { 1585 btf_ext_data = data; 1586 } else if (sh.sh_type == SHT_SYMTAB) { 1587 if (obj->efile.symbols) { 1588 pr_warning("bpf: multiple SYMTAB in %s\n", 1589 obj->path); 1590 return -LIBBPF_ERRNO__FORMAT; 1591 } 1592 obj->efile.symbols = data; 1593 obj->efile.strtabidx = sh.sh_link; 1594 } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) { 1595 if (sh.sh_flags & SHF_EXECINSTR) { 1596 if (strcmp(name, ".text") == 0) 1597 obj->efile.text_shndx = idx; 1598 err = bpf_object__add_program(obj, data->d_buf, 1599 data->d_size, name, idx); 1600 if (err) { 1601 char errmsg[STRERR_BUFSIZE]; 1602 char *cp = libbpf_strerror_r(-err, errmsg, 1603 sizeof(errmsg)); 1604 1605 pr_warning("failed to alloc program %s (%s): %s", 1606 name, obj->path, cp); 1607 return err; 1608 } 1609 } else if (strcmp(name, ".data") == 0) { 1610 obj->efile.data = data; 1611 obj->efile.data_shndx = idx; 1612 } else if (strcmp(name, ".rodata") == 0) { 1613 obj->efile.rodata = data; 1614 obj->efile.rodata_shndx = idx; 1615 } else { 1616 pr_debug("skip section(%d) %s\n", idx, name); 1617 } 1618 } else if (sh.sh_type == SHT_REL) { 1619 int nr_reloc = obj->efile.nr_reloc; 1620 void *reloc = obj->efile.reloc; 1621 int sec = sh.sh_info; /* points to other section */ 1622 1623 /* Only do relo for section with exec instructions */ 1624 if (!section_have_execinstr(obj, sec)) { 1625 pr_debug("skip relo %s(%d) for section(%d)\n", 1626 name, idx, sec); 1627 continue; 1628 } 1629 1630 reloc = reallocarray(reloc, nr_reloc + 1, 1631 sizeof(*obj->efile.reloc)); 1632 if (!reloc) { 1633 pr_warning("realloc failed\n"); 1634 return -ENOMEM; 1635 } 1636 1637 obj->efile.reloc = reloc; 1638 obj->efile.nr_reloc++; 1639 1640 obj->efile.reloc[nr_reloc].shdr = sh; 1641 obj->efile.reloc[nr_reloc].data = data; 1642 } else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) { 1643 obj->efile.bss = data; 1644 obj->efile.bss_shndx = idx; 1645 } else { 1646 pr_debug("skip section(%d) %s\n", idx, name); 1647 } 1648 } 1649 1650 if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) { 1651 pr_warning("Corrupted ELF file: index of strtab invalid\n"); 1652 return -LIBBPF_ERRNO__FORMAT; 1653 } 1654 err = bpf_object__init_btf(obj, btf_data, btf_ext_data); 1655 if (!err) 1656 err = bpf_object__init_maps(obj, flags); 1657 if (!err) 1658 err = bpf_object__sanitize_and_load_btf(obj); 1659 if (!err) 1660 err = bpf_object__init_prog_names(obj); 1661 return err; 1662 } 1663 1664 static struct bpf_program * 1665 bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx) 1666 { 1667 struct bpf_program *prog; 1668 size_t i; 1669 1670 for (i = 0; i < obj->nr_programs; i++) { 1671 prog = &obj->programs[i]; 1672 if (prog->idx == idx) 1673 return prog; 1674 } 1675 return NULL; 1676 } 1677 1678 struct bpf_program * 1679 bpf_object__find_program_by_title(const struct bpf_object *obj, 1680 const char *title) 1681 { 1682 struct bpf_program *pos; 1683 1684 bpf_object__for_each_program(pos, obj) { 1685 if (pos->section_name && !strcmp(pos->section_name, title)) 1686 return pos; 1687 } 1688 return NULL; 1689 } 1690 1691 static bool bpf_object__shndx_is_data(const struct bpf_object *obj, 1692 int shndx) 1693 { 1694 return shndx == obj->efile.data_shndx || 1695 shndx == obj->efile.bss_shndx || 1696 shndx == obj->efile.rodata_shndx; 1697 } 1698 1699 static bool bpf_object__shndx_is_maps(const struct bpf_object *obj, 1700 int shndx) 1701 { 1702 return shndx == obj->efile.maps_shndx || 1703 shndx == obj->efile.btf_maps_shndx; 1704 } 1705 1706 static bool bpf_object__relo_in_known_section(const struct bpf_object *obj, 1707 int shndx) 1708 { 1709 return shndx == obj->efile.text_shndx || 1710 bpf_object__shndx_is_maps(obj, shndx) || 1711 bpf_object__shndx_is_data(obj, shndx); 1712 } 1713 1714 static enum libbpf_map_type 1715 bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx) 1716 { 1717 if (shndx == obj->efile.data_shndx) 1718 return LIBBPF_MAP_DATA; 1719 else if (shndx == obj->efile.bss_shndx) 1720 return LIBBPF_MAP_BSS; 1721 else if (shndx == obj->efile.rodata_shndx) 1722 return LIBBPF_MAP_RODATA; 1723 else 1724 return LIBBPF_MAP_UNSPEC; 1725 } 1726 1727 static int 1728 bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, 1729 Elf_Data *data, struct bpf_object *obj) 1730 { 1731 Elf_Data *symbols = obj->efile.symbols; 1732 struct bpf_map *maps = obj->maps; 1733 size_t nr_maps = obj->nr_maps; 1734 int i, nrels; 1735 1736 pr_debug("collecting relocating info for: '%s'\n", prog->section_name); 1737 nrels = shdr->sh_size / shdr->sh_entsize; 1738 1739 prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels); 1740 if (!prog->reloc_desc) { 1741 pr_warning("failed to alloc memory in relocation\n"); 1742 return -ENOMEM; 1743 } 1744 prog->nr_reloc = nrels; 1745 1746 for (i = 0; i < nrels; i++) { 1747 struct bpf_insn *insns = prog->insns; 1748 enum libbpf_map_type type; 1749 unsigned int insn_idx; 1750 unsigned int shdr_idx; 1751 const char *name; 1752 size_t map_idx; 1753 GElf_Sym sym; 1754 GElf_Rel rel; 1755 1756 if (!gelf_getrel(data, i, &rel)) { 1757 pr_warning("relocation: failed to get %d reloc\n", i); 1758 return -LIBBPF_ERRNO__FORMAT; 1759 } 1760 1761 if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) { 1762 pr_warning("relocation: symbol %"PRIx64" not found\n", 1763 GELF_R_SYM(rel.r_info)); 1764 return -LIBBPF_ERRNO__FORMAT; 1765 } 1766 1767 name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, 1768 sym.st_name) ? : "<?>"; 1769 1770 pr_debug("relo for %lld value %lld name %d (\'%s\')\n", 1771 (long long) (rel.r_info >> 32), 1772 (long long) sym.st_value, sym.st_name, name); 1773 1774 shdr_idx = sym.st_shndx; 1775 if (!bpf_object__relo_in_known_section(obj, shdr_idx)) { 1776 pr_warning("Program '%s' contains unrecognized relo data pointing to section %u\n", 1777 prog->section_name, shdr_idx); 1778 return -LIBBPF_ERRNO__RELOC; 1779 } 1780 1781 insn_idx = rel.r_offset / sizeof(struct bpf_insn); 1782 pr_debug("relocation: insn_idx=%u\n", insn_idx); 1783 1784 if (insns[insn_idx].code == (BPF_JMP | BPF_CALL)) { 1785 if (insns[insn_idx].src_reg != BPF_PSEUDO_CALL) { 1786 pr_warning("incorrect bpf_call opcode\n"); 1787 return -LIBBPF_ERRNO__RELOC; 1788 } 1789 prog->reloc_desc[i].type = RELO_CALL; 1790 prog->reloc_desc[i].insn_idx = insn_idx; 1791 prog->reloc_desc[i].text_off = sym.st_value; 1792 obj->has_pseudo_calls = true; 1793 continue; 1794 } 1795 1796 if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) { 1797 pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n", 1798 insn_idx, insns[insn_idx].code); 1799 return -LIBBPF_ERRNO__RELOC; 1800 } 1801 1802 if (bpf_object__shndx_is_maps(obj, shdr_idx) || 1803 bpf_object__shndx_is_data(obj, shdr_idx)) { 1804 type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx); 1805 if (type != LIBBPF_MAP_UNSPEC) { 1806 if (GELF_ST_BIND(sym.st_info) == STB_GLOBAL) { 1807 pr_warning("bpf: relocation: not yet supported relo for non-static global \'%s\' variable found in insns[%d].code 0x%x\n", 1808 name, insn_idx, insns[insn_idx].code); 1809 return -LIBBPF_ERRNO__RELOC; 1810 } 1811 if (!obj->caps.global_data) { 1812 pr_warning("bpf: relocation: kernel does not support global \'%s\' variable access in insns[%d]\n", 1813 name, insn_idx); 1814 return -LIBBPF_ERRNO__RELOC; 1815 } 1816 } 1817 1818 for (map_idx = 0; map_idx < nr_maps; map_idx++) { 1819 if (maps[map_idx].libbpf_type != type) 1820 continue; 1821 if (type != LIBBPF_MAP_UNSPEC || 1822 (maps[map_idx].sec_idx == sym.st_shndx && 1823 maps[map_idx].sec_offset == sym.st_value)) { 1824 pr_debug("relocation: found map %zd (%s, sec_idx %d, offset %zu) for insn %u\n", 1825 map_idx, maps[map_idx].name, 1826 maps[map_idx].sec_idx, 1827 maps[map_idx].sec_offset, 1828 insn_idx); 1829 break; 1830 } 1831 } 1832 1833 if (map_idx >= nr_maps) { 1834 pr_warning("bpf relocation: map_idx %d larger than %d\n", 1835 (int)map_idx, (int)nr_maps - 1); 1836 return -LIBBPF_ERRNO__RELOC; 1837 } 1838 1839 prog->reloc_desc[i].type = type != LIBBPF_MAP_UNSPEC ? 1840 RELO_DATA : RELO_LD64; 1841 prog->reloc_desc[i].insn_idx = insn_idx; 1842 prog->reloc_desc[i].map_idx = map_idx; 1843 } 1844 } 1845 return 0; 1846 } 1847 1848 static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map) 1849 { 1850 struct bpf_map_def *def = &map->def; 1851 __u32 key_type_id = 0, value_type_id = 0; 1852 int ret; 1853 1854 /* if it's BTF-defined map, we don't need to search for type IDs */ 1855 if (map->sec_idx == obj->efile.btf_maps_shndx) 1856 return 0; 1857 1858 if (!bpf_map__is_internal(map)) { 1859 ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size, 1860 def->value_size, &key_type_id, 1861 &value_type_id); 1862 } else { 1863 /* 1864 * LLVM annotates global data differently in BTF, that is, 1865 * only as '.data', '.bss' or '.rodata'. 1866 */ 1867 ret = btf__find_by_name(obj->btf, 1868 libbpf_type_to_btf_name[map->libbpf_type]); 1869 } 1870 if (ret < 0) 1871 return ret; 1872 1873 map->btf_key_type_id = key_type_id; 1874 map->btf_value_type_id = bpf_map__is_internal(map) ? 1875 ret : value_type_id; 1876 return 0; 1877 } 1878 1879 int bpf_map__reuse_fd(struct bpf_map *map, int fd) 1880 { 1881 struct bpf_map_info info = {}; 1882 __u32 len = sizeof(info); 1883 int new_fd, err; 1884 char *new_name; 1885 1886 err = bpf_obj_get_info_by_fd(fd, &info, &len); 1887 if (err) 1888 return err; 1889 1890 new_name = strdup(info.name); 1891 if (!new_name) 1892 return -errno; 1893 1894 new_fd = open("/", O_RDONLY | O_CLOEXEC); 1895 if (new_fd < 0) 1896 goto err_free_new_name; 1897 1898 new_fd = dup3(fd, new_fd, O_CLOEXEC); 1899 if (new_fd < 0) 1900 goto err_close_new_fd; 1901 1902 err = zclose(map->fd); 1903 if (err) 1904 goto err_close_new_fd; 1905 free(map->name); 1906 1907 map->fd = new_fd; 1908 map->name = new_name; 1909 map->def.type = info.type; 1910 map->def.key_size = info.key_size; 1911 map->def.value_size = info.value_size; 1912 map->def.max_entries = info.max_entries; 1913 map->def.map_flags = info.map_flags; 1914 map->btf_key_type_id = info.btf_key_type_id; 1915 map->btf_value_type_id = info.btf_value_type_id; 1916 1917 return 0; 1918 1919 err_close_new_fd: 1920 close(new_fd); 1921 err_free_new_name: 1922 free(new_name); 1923 return -errno; 1924 } 1925 1926 int bpf_map__resize(struct bpf_map *map, __u32 max_entries) 1927 { 1928 if (!map || !max_entries) 1929 return -EINVAL; 1930 1931 /* If map already created, its attributes can't be changed. */ 1932 if (map->fd >= 0) 1933 return -EBUSY; 1934 1935 map->def.max_entries = max_entries; 1936 1937 return 0; 1938 } 1939 1940 static int 1941 bpf_object__probe_name(struct bpf_object *obj) 1942 { 1943 struct bpf_load_program_attr attr; 1944 char *cp, errmsg[STRERR_BUFSIZE]; 1945 struct bpf_insn insns[] = { 1946 BPF_MOV64_IMM(BPF_REG_0, 0), 1947 BPF_EXIT_INSN(), 1948 }; 1949 int ret; 1950 1951 /* make sure basic loading works */ 1952 1953 memset(&attr, 0, sizeof(attr)); 1954 attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; 1955 attr.insns = insns; 1956 attr.insns_cnt = ARRAY_SIZE(insns); 1957 attr.license = "GPL"; 1958 1959 ret = bpf_load_program_xattr(&attr, NULL, 0); 1960 if (ret < 0) { 1961 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); 1962 pr_warning("Error in %s():%s(%d). Couldn't load basic 'r0 = 0' BPF program.\n", 1963 __func__, cp, errno); 1964 return -errno; 1965 } 1966 close(ret); 1967 1968 /* now try the same program, but with the name */ 1969 1970 attr.name = "test"; 1971 ret = bpf_load_program_xattr(&attr, NULL, 0); 1972 if (ret >= 0) { 1973 obj->caps.name = 1; 1974 close(ret); 1975 } 1976 1977 return 0; 1978 } 1979 1980 static int 1981 bpf_object__probe_global_data(struct bpf_object *obj) 1982 { 1983 struct bpf_load_program_attr prg_attr; 1984 struct bpf_create_map_attr map_attr; 1985 char *cp, errmsg[STRERR_BUFSIZE]; 1986 struct bpf_insn insns[] = { 1987 BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16), 1988 BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42), 1989 BPF_MOV64_IMM(BPF_REG_0, 0), 1990 BPF_EXIT_INSN(), 1991 }; 1992 int ret, map; 1993 1994 memset(&map_attr, 0, sizeof(map_attr)); 1995 map_attr.map_type = BPF_MAP_TYPE_ARRAY; 1996 map_attr.key_size = sizeof(int); 1997 map_attr.value_size = 32; 1998 map_attr.max_entries = 1; 1999 2000 map = bpf_create_map_xattr(&map_attr); 2001 if (map < 0) { 2002 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); 2003 pr_warning("Error in %s():%s(%d). Couldn't create simple array map.\n", 2004 __func__, cp, errno); 2005 return -errno; 2006 } 2007 2008 insns[0].imm = map; 2009 2010 memset(&prg_attr, 0, sizeof(prg_attr)); 2011 prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; 2012 prg_attr.insns = insns; 2013 prg_attr.insns_cnt = ARRAY_SIZE(insns); 2014 prg_attr.license = "GPL"; 2015 2016 ret = bpf_load_program_xattr(&prg_attr, NULL, 0); 2017 if (ret >= 0) { 2018 obj->caps.global_data = 1; 2019 close(ret); 2020 } 2021 2022 close(map); 2023 return 0; 2024 } 2025 2026 static int bpf_object__probe_btf_func(struct bpf_object *obj) 2027 { 2028 const char strs[] = "\0int\0x\0a"; 2029 /* void x(int a) {} */ 2030 __u32 types[] = { 2031 /* int */ 2032 BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ 2033 /* FUNC_PROTO */ /* [2] */ 2034 BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0), 2035 BTF_PARAM_ENC(7, 1), 2036 /* FUNC x */ /* [3] */ 2037 BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2), 2038 }; 2039 int btf_fd; 2040 2041 btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types), 2042 strs, sizeof(strs)); 2043 if (btf_fd >= 0) { 2044 obj->caps.btf_func = 1; 2045 close(btf_fd); 2046 return 1; 2047 } 2048 2049 return 0; 2050 } 2051 2052 static int bpf_object__probe_btf_datasec(struct bpf_object *obj) 2053 { 2054 const char strs[] = "\0x\0.data"; 2055 /* static int a; */ 2056 __u32 types[] = { 2057 /* int */ 2058 BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ 2059 /* VAR x */ /* [2] */ 2060 BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1), 2061 BTF_VAR_STATIC, 2062 /* DATASEC val */ /* [3] */ 2063 BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4), 2064 BTF_VAR_SECINFO_ENC(2, 0, 4), 2065 }; 2066 int btf_fd; 2067 2068 btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types), 2069 strs, sizeof(strs)); 2070 if (btf_fd >= 0) { 2071 obj->caps.btf_datasec = 1; 2072 close(btf_fd); 2073 return 1; 2074 } 2075 2076 return 0; 2077 } 2078 2079 static int 2080 bpf_object__probe_caps(struct bpf_object *obj) 2081 { 2082 int (*probe_fn[])(struct bpf_object *obj) = { 2083 bpf_object__probe_name, 2084 bpf_object__probe_global_data, 2085 bpf_object__probe_btf_func, 2086 bpf_object__probe_btf_datasec, 2087 }; 2088 int i, ret; 2089 2090 for (i = 0; i < ARRAY_SIZE(probe_fn); i++) { 2091 ret = probe_fn[i](obj); 2092 if (ret < 0) 2093 pr_debug("Probe #%d failed with %d.\n", i, ret); 2094 } 2095 2096 return 0; 2097 } 2098 2099 static int 2100 bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map) 2101 { 2102 char *cp, errmsg[STRERR_BUFSIZE]; 2103 int err, zero = 0; 2104 __u8 *data; 2105 2106 /* Nothing to do here since kernel already zero-initializes .bss map. */ 2107 if (map->libbpf_type == LIBBPF_MAP_BSS) 2108 return 0; 2109 2110 data = map->libbpf_type == LIBBPF_MAP_DATA ? 2111 obj->sections.data : obj->sections.rodata; 2112 2113 err = bpf_map_update_elem(map->fd, &zero, data, 0); 2114 /* Freeze .rodata map as read-only from syscall side. */ 2115 if (!err && map->libbpf_type == LIBBPF_MAP_RODATA) { 2116 err = bpf_map_freeze(map->fd); 2117 if (err) { 2118 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); 2119 pr_warning("Error freezing map(%s) as read-only: %s\n", 2120 map->name, cp); 2121 err = 0; 2122 } 2123 } 2124 return err; 2125 } 2126 2127 static int 2128 bpf_object__create_maps(struct bpf_object *obj) 2129 { 2130 struct bpf_create_map_attr create_attr = {}; 2131 int nr_cpus = 0; 2132 unsigned int i; 2133 int err; 2134 2135 for (i = 0; i < obj->nr_maps; i++) { 2136 struct bpf_map *map = &obj->maps[i]; 2137 struct bpf_map_def *def = &map->def; 2138 char *cp, errmsg[STRERR_BUFSIZE]; 2139 int *pfd = &map->fd; 2140 2141 if (map->fd >= 0) { 2142 pr_debug("skip map create (preset) %s: fd=%d\n", 2143 map->name, map->fd); 2144 continue; 2145 } 2146 2147 if (obj->caps.name) 2148 create_attr.name = map->name; 2149 create_attr.map_ifindex = map->map_ifindex; 2150 create_attr.map_type = def->type; 2151 create_attr.map_flags = def->map_flags; 2152 create_attr.key_size = def->key_size; 2153 create_attr.value_size = def->value_size; 2154 if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && 2155 !def->max_entries) { 2156 if (!nr_cpus) 2157 nr_cpus = libbpf_num_possible_cpus(); 2158 if (nr_cpus < 0) { 2159 pr_warning("failed to determine number of system CPUs: %d\n", 2160 nr_cpus); 2161 err = nr_cpus; 2162 goto err_out; 2163 } 2164 pr_debug("map '%s': setting size to %d\n", 2165 map->name, nr_cpus); 2166 create_attr.max_entries = nr_cpus; 2167 } else { 2168 create_attr.max_entries = def->max_entries; 2169 } 2170 create_attr.btf_fd = 0; 2171 create_attr.btf_key_type_id = 0; 2172 create_attr.btf_value_type_id = 0; 2173 if (bpf_map_type__is_map_in_map(def->type) && 2174 map->inner_map_fd >= 0) 2175 create_attr.inner_map_fd = map->inner_map_fd; 2176 2177 if (obj->btf && !bpf_map_find_btf_info(obj, map)) { 2178 create_attr.btf_fd = btf__fd(obj->btf); 2179 create_attr.btf_key_type_id = map->btf_key_type_id; 2180 create_attr.btf_value_type_id = map->btf_value_type_id; 2181 } 2182 2183 *pfd = bpf_create_map_xattr(&create_attr); 2184 if (*pfd < 0 && (create_attr.btf_key_type_id || 2185 create_attr.btf_value_type_id)) { 2186 err = -errno; 2187 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); 2188 pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", 2189 map->name, cp, err); 2190 create_attr.btf_fd = 0; 2191 create_attr.btf_key_type_id = 0; 2192 create_attr.btf_value_type_id = 0; 2193 map->btf_key_type_id = 0; 2194 map->btf_value_type_id = 0; 2195 *pfd = bpf_create_map_xattr(&create_attr); 2196 } 2197 2198 if (*pfd < 0) { 2199 size_t j; 2200 2201 err = -errno; 2202 err_out: 2203 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); 2204 pr_warning("failed to create map (name: '%s'): %s(%d)\n", 2205 map->name, cp, err); 2206 for (j = 0; j < i; j++) 2207 zclose(obj->maps[j].fd); 2208 return err; 2209 } 2210 2211 if (bpf_map__is_internal(map)) { 2212 err = bpf_object__populate_internal_map(obj, map); 2213 if (err < 0) { 2214 zclose(*pfd); 2215 goto err_out; 2216 } 2217 } 2218 2219 pr_debug("created map %s: fd=%d\n", map->name, *pfd); 2220 } 2221 2222 return 0; 2223 } 2224 2225 static int 2226 check_btf_ext_reloc_err(struct bpf_program *prog, int err, 2227 void *btf_prog_info, const char *info_name) 2228 { 2229 if (err != -ENOENT) { 2230 pr_warning("Error in loading %s for sec %s.\n", 2231 info_name, prog->section_name); 2232 return err; 2233 } 2234 2235 /* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */ 2236 2237 if (btf_prog_info) { 2238 /* 2239 * Some info has already been found but has problem 2240 * in the last btf_ext reloc. Must have to error out. 2241 */ 2242 pr_warning("Error in relocating %s for sec %s.\n", 2243 info_name, prog->section_name); 2244 return err; 2245 } 2246 2247 /* Have problem loading the very first info. Ignore the rest. */ 2248 pr_warning("Cannot find %s for main program sec %s. Ignore all %s.\n", 2249 info_name, prog->section_name, info_name); 2250 return 0; 2251 } 2252 2253 static int 2254 bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj, 2255 const char *section_name, __u32 insn_offset) 2256 { 2257 int err; 2258 2259 if (!insn_offset || prog->func_info) { 2260 /* 2261 * !insn_offset => main program 2262 * 2263 * For sub prog, the main program's func_info has to 2264 * be loaded first (i.e. prog->func_info != NULL) 2265 */ 2266 err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext, 2267 section_name, insn_offset, 2268 &prog->func_info, 2269 &prog->func_info_cnt); 2270 if (err) 2271 return check_btf_ext_reloc_err(prog, err, 2272 prog->func_info, 2273 "bpf_func_info"); 2274 2275 prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext); 2276 } 2277 2278 if (!insn_offset || prog->line_info) { 2279 err = btf_ext__reloc_line_info(obj->btf, obj->btf_ext, 2280 section_name, insn_offset, 2281 &prog->line_info, 2282 &prog->line_info_cnt); 2283 if (err) 2284 return check_btf_ext_reloc_err(prog, err, 2285 prog->line_info, 2286 "bpf_line_info"); 2287 2288 prog->line_info_rec_size = btf_ext__line_info_rec_size(obj->btf_ext); 2289 } 2290 2291 if (!insn_offset) 2292 prog->btf_fd = btf__fd(obj->btf); 2293 2294 return 0; 2295 } 2296 2297 static int 2298 bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj, 2299 struct reloc_desc *relo) 2300 { 2301 struct bpf_insn *insn, *new_insn; 2302 struct bpf_program *text; 2303 size_t new_cnt; 2304 int err; 2305 2306 if (relo->type != RELO_CALL) 2307 return -LIBBPF_ERRNO__RELOC; 2308 2309 if (prog->idx == obj->efile.text_shndx) { 2310 pr_warning("relo in .text insn %d into off %d\n", 2311 relo->insn_idx, relo->text_off); 2312 return -LIBBPF_ERRNO__RELOC; 2313 } 2314 2315 if (prog->main_prog_cnt == 0) { 2316 text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx); 2317 if (!text) { 2318 pr_warning("no .text section found yet relo into text exist\n"); 2319 return -LIBBPF_ERRNO__RELOC; 2320 } 2321 new_cnt = prog->insns_cnt + text->insns_cnt; 2322 new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn)); 2323 if (!new_insn) { 2324 pr_warning("oom in prog realloc\n"); 2325 return -ENOMEM; 2326 } 2327 2328 if (obj->btf_ext) { 2329 err = bpf_program_reloc_btf_ext(prog, obj, 2330 text->section_name, 2331 prog->insns_cnt); 2332 if (err) 2333 return err; 2334 } 2335 2336 memcpy(new_insn + prog->insns_cnt, text->insns, 2337 text->insns_cnt * sizeof(*insn)); 2338 prog->insns = new_insn; 2339 prog->main_prog_cnt = prog->insns_cnt; 2340 prog->insns_cnt = new_cnt; 2341 pr_debug("added %zd insn from %s to prog %s\n", 2342 text->insns_cnt, text->section_name, 2343 prog->section_name); 2344 } 2345 insn = &prog->insns[relo->insn_idx]; 2346 insn->imm += prog->main_prog_cnt - relo->insn_idx; 2347 return 0; 2348 } 2349 2350 static int 2351 bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) 2352 { 2353 int i, err; 2354 2355 if (!prog) 2356 return 0; 2357 2358 if (obj->btf_ext) { 2359 err = bpf_program_reloc_btf_ext(prog, obj, 2360 prog->section_name, 0); 2361 if (err) 2362 return err; 2363 } 2364 2365 if (!prog->reloc_desc) 2366 return 0; 2367 2368 for (i = 0; i < prog->nr_reloc; i++) { 2369 if (prog->reloc_desc[i].type == RELO_LD64 || 2370 prog->reloc_desc[i].type == RELO_DATA) { 2371 bool relo_data = prog->reloc_desc[i].type == RELO_DATA; 2372 struct bpf_insn *insns = prog->insns; 2373 int insn_idx, map_idx; 2374 2375 insn_idx = prog->reloc_desc[i].insn_idx; 2376 map_idx = prog->reloc_desc[i].map_idx; 2377 2378 if (insn_idx + 1 >= (int)prog->insns_cnt) { 2379 pr_warning("relocation out of range: '%s'\n", 2380 prog->section_name); 2381 return -LIBBPF_ERRNO__RELOC; 2382 } 2383 2384 if (!relo_data) { 2385 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD; 2386 } else { 2387 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_VALUE; 2388 insns[insn_idx + 1].imm = insns[insn_idx].imm; 2389 } 2390 insns[insn_idx].imm = obj->maps[map_idx].fd; 2391 } else if (prog->reloc_desc[i].type == RELO_CALL) { 2392 err = bpf_program__reloc_text(prog, obj, 2393 &prog->reloc_desc[i]); 2394 if (err) 2395 return err; 2396 } 2397 } 2398 2399 zfree(&prog->reloc_desc); 2400 prog->nr_reloc = 0; 2401 return 0; 2402 } 2403 2404 2405 static int 2406 bpf_object__relocate(struct bpf_object *obj) 2407 { 2408 struct bpf_program *prog; 2409 size_t i; 2410 int err; 2411 2412 for (i = 0; i < obj->nr_programs; i++) { 2413 prog = &obj->programs[i]; 2414 2415 err = bpf_program__relocate(prog, obj); 2416 if (err) { 2417 pr_warning("failed to relocate '%s'\n", 2418 prog->section_name); 2419 return err; 2420 } 2421 } 2422 return 0; 2423 } 2424 2425 static int bpf_object__collect_reloc(struct bpf_object *obj) 2426 { 2427 int i, err; 2428 2429 if (!obj_elf_valid(obj)) { 2430 pr_warning("Internal error: elf object is closed\n"); 2431 return -LIBBPF_ERRNO__INTERNAL; 2432 } 2433 2434 for (i = 0; i < obj->efile.nr_reloc; i++) { 2435 GElf_Shdr *shdr = &obj->efile.reloc[i].shdr; 2436 Elf_Data *data = obj->efile.reloc[i].data; 2437 int idx = shdr->sh_info; 2438 struct bpf_program *prog; 2439 2440 if (shdr->sh_type != SHT_REL) { 2441 pr_warning("internal error at %d\n", __LINE__); 2442 return -LIBBPF_ERRNO__INTERNAL; 2443 } 2444 2445 prog = bpf_object__find_prog_by_idx(obj, idx); 2446 if (!prog) { 2447 pr_warning("relocation failed: no section(%d)\n", idx); 2448 return -LIBBPF_ERRNO__RELOC; 2449 } 2450 2451 err = bpf_program__collect_reloc(prog, shdr, data, obj); 2452 if (err) 2453 return err; 2454 } 2455 return 0; 2456 } 2457 2458 static int 2459 load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, 2460 char *license, __u32 kern_version, int *pfd) 2461 { 2462 struct bpf_load_program_attr load_attr; 2463 char *cp, errmsg[STRERR_BUFSIZE]; 2464 int log_buf_size = BPF_LOG_BUF_SIZE; 2465 char *log_buf; 2466 int ret; 2467 2468 if (!insns || !insns_cnt) 2469 return -EINVAL; 2470 2471 memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); 2472 load_attr.prog_type = prog->type; 2473 load_attr.expected_attach_type = prog->expected_attach_type; 2474 if (prog->caps->name) 2475 load_attr.name = prog->name; 2476 load_attr.insns = insns; 2477 load_attr.insns_cnt = insns_cnt; 2478 load_attr.license = license; 2479 load_attr.kern_version = kern_version; 2480 load_attr.prog_ifindex = prog->prog_ifindex; 2481 load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0; 2482 load_attr.func_info = prog->func_info; 2483 load_attr.func_info_rec_size = prog->func_info_rec_size; 2484 load_attr.func_info_cnt = prog->func_info_cnt; 2485 load_attr.line_info = prog->line_info; 2486 load_attr.line_info_rec_size = prog->line_info_rec_size; 2487 load_attr.line_info_cnt = prog->line_info_cnt; 2488 load_attr.log_level = prog->log_level; 2489 load_attr.prog_flags = prog->prog_flags; 2490 2491 retry_load: 2492 log_buf = malloc(log_buf_size); 2493 if (!log_buf) 2494 pr_warning("Alloc log buffer for bpf loader error, continue without log\n"); 2495 2496 ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size); 2497 2498 if (ret >= 0) { 2499 if (load_attr.log_level) 2500 pr_debug("verifier log:\n%s", log_buf); 2501 *pfd = ret; 2502 ret = 0; 2503 goto out; 2504 } 2505 2506 if (errno == ENOSPC) { 2507 log_buf_size <<= 1; 2508 free(log_buf); 2509 goto retry_load; 2510 } 2511 ret = -LIBBPF_ERRNO__LOAD; 2512 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); 2513 pr_warning("load bpf program failed: %s\n", cp); 2514 2515 if (log_buf && log_buf[0] != '\0') { 2516 ret = -LIBBPF_ERRNO__VERIFY; 2517 pr_warning("-- BEGIN DUMP LOG ---\n"); 2518 pr_warning("\n%s\n", log_buf); 2519 pr_warning("-- END LOG --\n"); 2520 } else if (load_attr.insns_cnt >= BPF_MAXINSNS) { 2521 pr_warning("Program too large (%zu insns), at most %d insns\n", 2522 load_attr.insns_cnt, BPF_MAXINSNS); 2523 ret = -LIBBPF_ERRNO__PROG2BIG; 2524 } else { 2525 /* Wrong program type? */ 2526 if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) { 2527 int fd; 2528 2529 load_attr.prog_type = BPF_PROG_TYPE_KPROBE; 2530 load_attr.expected_attach_type = 0; 2531 fd = bpf_load_program_xattr(&load_attr, NULL, 0); 2532 if (fd >= 0) { 2533 close(fd); 2534 ret = -LIBBPF_ERRNO__PROGTYPE; 2535 goto out; 2536 } 2537 } 2538 2539 if (log_buf) 2540 ret = -LIBBPF_ERRNO__KVER; 2541 } 2542 2543 out: 2544 free(log_buf); 2545 return ret; 2546 } 2547 2548 int 2549 bpf_program__load(struct bpf_program *prog, 2550 char *license, __u32 kern_version) 2551 { 2552 int err = 0, fd, i; 2553 2554 if (prog->instances.nr < 0 || !prog->instances.fds) { 2555 if (prog->preprocessor) { 2556 pr_warning("Internal error: can't load program '%s'\n", 2557 prog->section_name); 2558 return -LIBBPF_ERRNO__INTERNAL; 2559 } 2560 2561 prog->instances.fds = malloc(sizeof(int)); 2562 if (!prog->instances.fds) { 2563 pr_warning("Not enough memory for BPF fds\n"); 2564 return -ENOMEM; 2565 } 2566 prog->instances.nr = 1; 2567 prog->instances.fds[0] = -1; 2568 } 2569 2570 if (!prog->preprocessor) { 2571 if (prog->instances.nr != 1) { 2572 pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n", 2573 prog->section_name, prog->instances.nr); 2574 } 2575 err = load_program(prog, prog->insns, prog->insns_cnt, 2576 license, kern_version, &fd); 2577 if (!err) 2578 prog->instances.fds[0] = fd; 2579 goto out; 2580 } 2581 2582 for (i = 0; i < prog->instances.nr; i++) { 2583 struct bpf_prog_prep_result result; 2584 bpf_program_prep_t preprocessor = prog->preprocessor; 2585 2586 memset(&result, 0, sizeof(result)); 2587 err = preprocessor(prog, i, prog->insns, 2588 prog->insns_cnt, &result); 2589 if (err) { 2590 pr_warning("Preprocessing the %dth instance of program '%s' failed\n", 2591 i, prog->section_name); 2592 goto out; 2593 } 2594 2595 if (!result.new_insn_ptr || !result.new_insn_cnt) { 2596 pr_debug("Skip loading the %dth instance of program '%s'\n", 2597 i, prog->section_name); 2598 prog->instances.fds[i] = -1; 2599 if (result.pfd) 2600 *result.pfd = -1; 2601 continue; 2602 } 2603 2604 err = load_program(prog, result.new_insn_ptr, 2605 result.new_insn_cnt, 2606 license, kern_version, &fd); 2607 2608 if (err) { 2609 pr_warning("Loading the %dth instance of program '%s' failed\n", 2610 i, prog->section_name); 2611 goto out; 2612 } 2613 2614 if (result.pfd) 2615 *result.pfd = fd; 2616 prog->instances.fds[i] = fd; 2617 } 2618 out: 2619 if (err) 2620 pr_warning("failed to load program '%s'\n", 2621 prog->section_name); 2622 zfree(&prog->insns); 2623 prog->insns_cnt = 0; 2624 return err; 2625 } 2626 2627 static bool bpf_program__is_function_storage(const struct bpf_program *prog, 2628 const struct bpf_object *obj) 2629 { 2630 return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls; 2631 } 2632 2633 static int 2634 bpf_object__load_progs(struct bpf_object *obj, int log_level) 2635 { 2636 size_t i; 2637 int err; 2638 2639 for (i = 0; i < obj->nr_programs; i++) { 2640 if (bpf_program__is_function_storage(&obj->programs[i], obj)) 2641 continue; 2642 obj->programs[i].log_level |= log_level; 2643 err = bpf_program__load(&obj->programs[i], 2644 obj->license, 2645 obj->kern_version); 2646 if (err) 2647 return err; 2648 } 2649 return 0; 2650 } 2651 2652 static bool bpf_prog_type__needs_kver(enum bpf_prog_type type) 2653 { 2654 switch (type) { 2655 case BPF_PROG_TYPE_SOCKET_FILTER: 2656 case BPF_PROG_TYPE_SCHED_CLS: 2657 case BPF_PROG_TYPE_SCHED_ACT: 2658 case BPF_PROG_TYPE_XDP: 2659 case BPF_PROG_TYPE_CGROUP_SKB: 2660 case BPF_PROG_TYPE_CGROUP_SOCK: 2661 case BPF_PROG_TYPE_LWT_IN: 2662 case BPF_PROG_TYPE_LWT_OUT: 2663 case BPF_PROG_TYPE_LWT_XMIT: 2664 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 2665 case BPF_PROG_TYPE_SOCK_OPS: 2666 case BPF_PROG_TYPE_SK_SKB: 2667 case BPF_PROG_TYPE_CGROUP_DEVICE: 2668 case BPF_PROG_TYPE_SK_MSG: 2669 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 2670 case BPF_PROG_TYPE_LIRC_MODE2: 2671 case BPF_PROG_TYPE_SK_REUSEPORT: 2672 case BPF_PROG_TYPE_FLOW_DISSECTOR: 2673 case BPF_PROG_TYPE_UNSPEC: 2674 case BPF_PROG_TYPE_TRACEPOINT: 2675 case BPF_PROG_TYPE_RAW_TRACEPOINT: 2676 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE: 2677 case BPF_PROG_TYPE_PERF_EVENT: 2678 case BPF_PROG_TYPE_CGROUP_SYSCTL: 2679 case BPF_PROG_TYPE_CGROUP_SOCKOPT: 2680 return false; 2681 case BPF_PROG_TYPE_KPROBE: 2682 default: 2683 return true; 2684 } 2685 } 2686 2687 static int bpf_object__validate(struct bpf_object *obj, bool needs_kver) 2688 { 2689 if (needs_kver && obj->kern_version == 0) { 2690 pr_warning("%s doesn't provide kernel version\n", 2691 obj->path); 2692 return -LIBBPF_ERRNO__KVERSION; 2693 } 2694 return 0; 2695 } 2696 2697 static struct bpf_object * 2698 __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz, 2699 bool needs_kver, int flags) 2700 { 2701 struct bpf_object *obj; 2702 int err; 2703 2704 if (elf_version(EV_CURRENT) == EV_NONE) { 2705 pr_warning("failed to init libelf for %s\n", path); 2706 return ERR_PTR(-LIBBPF_ERRNO__LIBELF); 2707 } 2708 2709 obj = bpf_object__new(path, obj_buf, obj_buf_sz); 2710 if (IS_ERR(obj)) 2711 return obj; 2712 2713 CHECK_ERR(bpf_object__elf_init(obj), err, out); 2714 CHECK_ERR(bpf_object__check_endianness(obj), err, out); 2715 CHECK_ERR(bpf_object__probe_caps(obj), err, out); 2716 CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out); 2717 CHECK_ERR(bpf_object__collect_reloc(obj), err, out); 2718 CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out); 2719 2720 bpf_object__elf_finish(obj); 2721 return obj; 2722 out: 2723 bpf_object__close(obj); 2724 return ERR_PTR(err); 2725 } 2726 2727 struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr, 2728 int flags) 2729 { 2730 /* param validation */ 2731 if (!attr->file) 2732 return NULL; 2733 2734 pr_debug("loading %s\n", attr->file); 2735 2736 return __bpf_object__open(attr->file, NULL, 0, 2737 bpf_prog_type__needs_kver(attr->prog_type), 2738 flags); 2739 } 2740 2741 struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr) 2742 { 2743 return __bpf_object__open_xattr(attr, 0); 2744 } 2745 2746 struct bpf_object *bpf_object__open(const char *path) 2747 { 2748 struct bpf_object_open_attr attr = { 2749 .file = path, 2750 .prog_type = BPF_PROG_TYPE_UNSPEC, 2751 }; 2752 2753 return bpf_object__open_xattr(&attr); 2754 } 2755 2756 struct bpf_object *bpf_object__open_buffer(void *obj_buf, 2757 size_t obj_buf_sz, 2758 const char *name) 2759 { 2760 char tmp_name[64]; 2761 2762 /* param validation */ 2763 if (!obj_buf || obj_buf_sz <= 0) 2764 return NULL; 2765 2766 if (!name) { 2767 snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx", 2768 (unsigned long)obj_buf, 2769 (unsigned long)obj_buf_sz); 2770 name = tmp_name; 2771 } 2772 pr_debug("loading object '%s' from buffer\n", name); 2773 2774 return __bpf_object__open(name, obj_buf, obj_buf_sz, true, true); 2775 } 2776 2777 int bpf_object__unload(struct bpf_object *obj) 2778 { 2779 size_t i; 2780 2781 if (!obj) 2782 return -EINVAL; 2783 2784 for (i = 0; i < obj->nr_maps; i++) 2785 zclose(obj->maps[i].fd); 2786 2787 for (i = 0; i < obj->nr_programs; i++) 2788 bpf_program__unload(&obj->programs[i]); 2789 2790 return 0; 2791 } 2792 2793 int bpf_object__load_xattr(struct bpf_object_load_attr *attr) 2794 { 2795 struct bpf_object *obj; 2796 int err; 2797 2798 if (!attr) 2799 return -EINVAL; 2800 obj = attr->obj; 2801 if (!obj) 2802 return -EINVAL; 2803 2804 if (obj->loaded) { 2805 pr_warning("object should not be loaded twice\n"); 2806 return -EINVAL; 2807 } 2808 2809 obj->loaded = true; 2810 2811 CHECK_ERR(bpf_object__create_maps(obj), err, out); 2812 CHECK_ERR(bpf_object__relocate(obj), err, out); 2813 CHECK_ERR(bpf_object__load_progs(obj, attr->log_level), err, out); 2814 2815 return 0; 2816 out: 2817 bpf_object__unload(obj); 2818 pr_warning("failed to load object '%s'\n", obj->path); 2819 return err; 2820 } 2821 2822 int bpf_object__load(struct bpf_object *obj) 2823 { 2824 struct bpf_object_load_attr attr = { 2825 .obj = obj, 2826 }; 2827 2828 return bpf_object__load_xattr(&attr); 2829 } 2830 2831 static int check_path(const char *path) 2832 { 2833 char *cp, errmsg[STRERR_BUFSIZE]; 2834 struct statfs st_fs; 2835 char *dname, *dir; 2836 int err = 0; 2837 2838 if (path == NULL) 2839 return -EINVAL; 2840 2841 dname = strdup(path); 2842 if (dname == NULL) 2843 return -ENOMEM; 2844 2845 dir = dirname(dname); 2846 if (statfs(dir, &st_fs)) { 2847 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); 2848 pr_warning("failed to statfs %s: %s\n", dir, cp); 2849 err = -errno; 2850 } 2851 free(dname); 2852 2853 if (!err && st_fs.f_type != BPF_FS_MAGIC) { 2854 pr_warning("specified path %s is not on BPF FS\n", path); 2855 err = -EINVAL; 2856 } 2857 2858 return err; 2859 } 2860 2861 int bpf_program__pin_instance(struct bpf_program *prog, const char *path, 2862 int instance) 2863 { 2864 char *cp, errmsg[STRERR_BUFSIZE]; 2865 int err; 2866 2867 err = check_path(path); 2868 if (err) 2869 return err; 2870 2871 if (prog == NULL) { 2872 pr_warning("invalid program pointer\n"); 2873 return -EINVAL; 2874 } 2875 2876 if (instance < 0 || instance >= prog->instances.nr) { 2877 pr_warning("invalid prog instance %d of prog %s (max %d)\n", 2878 instance, prog->section_name, prog->instances.nr); 2879 return -EINVAL; 2880 } 2881 2882 if (bpf_obj_pin(prog->instances.fds[instance], path)) { 2883 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); 2884 pr_warning("failed to pin program: %s\n", cp); 2885 return -errno; 2886 } 2887 pr_debug("pinned program '%s'\n", path); 2888 2889 return 0; 2890 } 2891 2892 int bpf_program__unpin_instance(struct bpf_program *prog, const char *path, 2893 int instance) 2894 { 2895 int err; 2896 2897 err = check_path(path); 2898 if (err) 2899 return err; 2900 2901 if (prog == NULL) { 2902 pr_warning("invalid program pointer\n"); 2903 return -EINVAL; 2904 } 2905 2906 if (instance < 0 || instance >= prog->instances.nr) { 2907 pr_warning("invalid prog instance %d of prog %s (max %d)\n", 2908 instance, prog->section_name, prog->instances.nr); 2909 return -EINVAL; 2910 } 2911 2912 err = unlink(path); 2913 if (err != 0) 2914 return -errno; 2915 pr_debug("unpinned program '%s'\n", path); 2916 2917 return 0; 2918 } 2919 2920 static int make_dir(const char *path) 2921 { 2922 char *cp, errmsg[STRERR_BUFSIZE]; 2923 int err = 0; 2924 2925 if (mkdir(path, 0700) && errno != EEXIST) 2926 err = -errno; 2927 2928 if (err) { 2929 cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg)); 2930 pr_warning("failed to mkdir %s: %s\n", path, cp); 2931 } 2932 return err; 2933 } 2934 2935 int bpf_program__pin(struct bpf_program *prog, const char *path) 2936 { 2937 int i, err; 2938 2939 err = check_path(path); 2940 if (err) 2941 return err; 2942 2943 if (prog == NULL) { 2944 pr_warning("invalid program pointer\n"); 2945 return -EINVAL; 2946 } 2947 2948 if (prog->instances.nr <= 0) { 2949 pr_warning("no instances of prog %s to pin\n", 2950 prog->section_name); 2951 return -EINVAL; 2952 } 2953 2954 if (prog->instances.nr == 1) { 2955 /* don't create subdirs when pinning single instance */ 2956 return bpf_program__pin_instance(prog, path, 0); 2957 } 2958 2959 err = make_dir(path); 2960 if (err) 2961 return err; 2962 2963 for (i = 0; i < prog->instances.nr; i++) { 2964 char buf[PATH_MAX]; 2965 int len; 2966 2967 len = snprintf(buf, PATH_MAX, "%s/%d", path, i); 2968 if (len < 0) { 2969 err = -EINVAL; 2970 goto err_unpin; 2971 } else if (len >= PATH_MAX) { 2972 err = -ENAMETOOLONG; 2973 goto err_unpin; 2974 } 2975 2976 err = bpf_program__pin_instance(prog, buf, i); 2977 if (err) 2978 goto err_unpin; 2979 } 2980 2981 return 0; 2982 2983 err_unpin: 2984 for (i = i - 1; i >= 0; i--) { 2985 char buf[PATH_MAX]; 2986 int len; 2987 2988 len = snprintf(buf, PATH_MAX, "%s/%d", path, i); 2989 if (len < 0) 2990 continue; 2991 else if (len >= PATH_MAX) 2992 continue; 2993 2994 bpf_program__unpin_instance(prog, buf, i); 2995 } 2996 2997 rmdir(path); 2998 2999 return err; 3000 } 3001 3002 int bpf_program__unpin(struct bpf_program *prog, const char *path) 3003 { 3004 int i, err; 3005 3006 err = check_path(path); 3007 if (err) 3008 return err; 3009 3010 if (prog == NULL) { 3011 pr_warning("invalid program pointer\n"); 3012 return -EINVAL; 3013 } 3014 3015 if (prog->instances.nr <= 0) { 3016 pr_warning("no instances of prog %s to pin\n", 3017 prog->section_name); 3018 return -EINVAL; 3019 } 3020 3021 if (prog->instances.nr == 1) { 3022 /* don't create subdirs when pinning single instance */ 3023 return bpf_program__unpin_instance(prog, path, 0); 3024 } 3025 3026 for (i = 0; i < prog->instances.nr; i++) { 3027 char buf[PATH_MAX]; 3028 int len; 3029 3030 len = snprintf(buf, PATH_MAX, "%s/%d", path, i); 3031 if (len < 0) 3032 return -EINVAL; 3033 else if (len >= PATH_MAX) 3034 return -ENAMETOOLONG; 3035 3036 err = bpf_program__unpin_instance(prog, buf, i); 3037 if (err) 3038 return err; 3039 } 3040 3041 err = rmdir(path); 3042 if (err) 3043 return -errno; 3044 3045 return 0; 3046 } 3047 3048 int bpf_map__pin(struct bpf_map *map, const char *path) 3049 { 3050 char *cp, errmsg[STRERR_BUFSIZE]; 3051 int err; 3052 3053 err = check_path(path); 3054 if (err) 3055 return err; 3056 3057 if (map == NULL) { 3058 pr_warning("invalid map pointer\n"); 3059 return -EINVAL; 3060 } 3061 3062 if (bpf_obj_pin(map->fd, path)) { 3063 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); 3064 pr_warning("failed to pin map: %s\n", cp); 3065 return -errno; 3066 } 3067 3068 pr_debug("pinned map '%s'\n", path); 3069 3070 return 0; 3071 } 3072 3073 int bpf_map__unpin(struct bpf_map *map, const char *path) 3074 { 3075 int err; 3076 3077 err = check_path(path); 3078 if (err) 3079 return err; 3080 3081 if (map == NULL) { 3082 pr_warning("invalid map pointer\n"); 3083 return -EINVAL; 3084 } 3085 3086 err = unlink(path); 3087 if (err != 0) 3088 return -errno; 3089 pr_debug("unpinned map '%s'\n", path); 3090 3091 return 0; 3092 } 3093 3094 int bpf_object__pin_maps(struct bpf_object *obj, const char *path) 3095 { 3096 struct bpf_map *map; 3097 int err; 3098 3099 if (!obj) 3100 return -ENOENT; 3101 3102 if (!obj->loaded) { 3103 pr_warning("object not yet loaded; load it first\n"); 3104 return -ENOENT; 3105 } 3106 3107 err = make_dir(path); 3108 if (err) 3109 return err; 3110 3111 bpf_object__for_each_map(map, obj) { 3112 char buf[PATH_MAX]; 3113 int len; 3114 3115 len = snprintf(buf, PATH_MAX, "%s/%s", path, 3116 bpf_map__name(map)); 3117 if (len < 0) { 3118 err = -EINVAL; 3119 goto err_unpin_maps; 3120 } else if (len >= PATH_MAX) { 3121 err = -ENAMETOOLONG; 3122 goto err_unpin_maps; 3123 } 3124 3125 err = bpf_map__pin(map, buf); 3126 if (err) 3127 goto err_unpin_maps; 3128 } 3129 3130 return 0; 3131 3132 err_unpin_maps: 3133 while ((map = bpf_map__prev(map, obj))) { 3134 char buf[PATH_MAX]; 3135 int len; 3136 3137 len = snprintf(buf, PATH_MAX, "%s/%s", path, 3138 bpf_map__name(map)); 3139 if (len < 0) 3140 continue; 3141 else if (len >= PATH_MAX) 3142 continue; 3143 3144 bpf_map__unpin(map, buf); 3145 } 3146 3147 return err; 3148 } 3149 3150 int bpf_object__unpin_maps(struct bpf_object *obj, const char *path) 3151 { 3152 struct bpf_map *map; 3153 int err; 3154 3155 if (!obj) 3156 return -ENOENT; 3157 3158 bpf_object__for_each_map(map, obj) { 3159 char buf[PATH_MAX]; 3160 int len; 3161 3162 len = snprintf(buf, PATH_MAX, "%s/%s", path, 3163 bpf_map__name(map)); 3164 if (len < 0) 3165 return -EINVAL; 3166 else if (len >= PATH_MAX) 3167 return -ENAMETOOLONG; 3168 3169 err = bpf_map__unpin(map, buf); 3170 if (err) 3171 return err; 3172 } 3173 3174 return 0; 3175 } 3176 3177 int bpf_object__pin_programs(struct bpf_object *obj, const char *path) 3178 { 3179 struct bpf_program *prog; 3180 int err; 3181 3182 if (!obj) 3183 return -ENOENT; 3184 3185 if (!obj->loaded) { 3186 pr_warning("object not yet loaded; load it first\n"); 3187 return -ENOENT; 3188 } 3189 3190 err = make_dir(path); 3191 if (err) 3192 return err; 3193 3194 bpf_object__for_each_program(prog, obj) { 3195 char buf[PATH_MAX]; 3196 int len; 3197 3198 len = snprintf(buf, PATH_MAX, "%s/%s", path, 3199 prog->pin_name); 3200 if (len < 0) { 3201 err = -EINVAL; 3202 goto err_unpin_programs; 3203 } else if (len >= PATH_MAX) { 3204 err = -ENAMETOOLONG; 3205 goto err_unpin_programs; 3206 } 3207 3208 err = bpf_program__pin(prog, buf); 3209 if (err) 3210 goto err_unpin_programs; 3211 } 3212 3213 return 0; 3214 3215 err_unpin_programs: 3216 while ((prog = bpf_program__prev(prog, obj))) { 3217 char buf[PATH_MAX]; 3218 int len; 3219 3220 len = snprintf(buf, PATH_MAX, "%s/%s", path, 3221 prog->pin_name); 3222 if (len < 0) 3223 continue; 3224 else if (len >= PATH_MAX) 3225 continue; 3226 3227 bpf_program__unpin(prog, buf); 3228 } 3229 3230 return err; 3231 } 3232 3233 int bpf_object__unpin_programs(struct bpf_object *obj, const char *path) 3234 { 3235 struct bpf_program *prog; 3236 int err; 3237 3238 if (!obj) 3239 return -ENOENT; 3240 3241 bpf_object__for_each_program(prog, obj) { 3242 char buf[PATH_MAX]; 3243 int len; 3244 3245 len = snprintf(buf, PATH_MAX, "%s/%s", path, 3246 prog->pin_name); 3247 if (len < 0) 3248 return -EINVAL; 3249 else if (len >= PATH_MAX) 3250 return -ENAMETOOLONG; 3251 3252 err = bpf_program__unpin(prog, buf); 3253 if (err) 3254 return err; 3255 } 3256 3257 return 0; 3258 } 3259 3260 int bpf_object__pin(struct bpf_object *obj, const char *path) 3261 { 3262 int err; 3263 3264 err = bpf_object__pin_maps(obj, path); 3265 if (err) 3266 return err; 3267 3268 err = bpf_object__pin_programs(obj, path); 3269 if (err) { 3270 bpf_object__unpin_maps(obj, path); 3271 return err; 3272 } 3273 3274 return 0; 3275 } 3276 3277 void bpf_object__close(struct bpf_object *obj) 3278 { 3279 size_t i; 3280 3281 if (!obj) 3282 return; 3283 3284 if (obj->clear_priv) 3285 obj->clear_priv(obj, obj->priv); 3286 3287 bpf_object__elf_finish(obj); 3288 bpf_object__unload(obj); 3289 btf__free(obj->btf); 3290 btf_ext__free(obj->btf_ext); 3291 3292 for (i = 0; i < obj->nr_maps; i++) { 3293 zfree(&obj->maps[i].name); 3294 if (obj->maps[i].clear_priv) 3295 obj->maps[i].clear_priv(&obj->maps[i], 3296 obj->maps[i].priv); 3297 obj->maps[i].priv = NULL; 3298 obj->maps[i].clear_priv = NULL; 3299 } 3300 3301 zfree(&obj->sections.rodata); 3302 zfree(&obj->sections.data); 3303 zfree(&obj->maps); 3304 obj->nr_maps = 0; 3305 3306 if (obj->programs && obj->nr_programs) { 3307 for (i = 0; i < obj->nr_programs; i++) 3308 bpf_program__exit(&obj->programs[i]); 3309 } 3310 zfree(&obj->programs); 3311 3312 list_del(&obj->list); 3313 free(obj); 3314 } 3315 3316 struct bpf_object * 3317 bpf_object__next(struct bpf_object *prev) 3318 { 3319 struct bpf_object *next; 3320 3321 if (!prev) 3322 next = list_first_entry(&bpf_objects_list, 3323 struct bpf_object, 3324 list); 3325 else 3326 next = list_next_entry(prev, list); 3327 3328 /* Empty list is noticed here so don't need checking on entry. */ 3329 if (&next->list == &bpf_objects_list) 3330 return NULL; 3331 3332 return next; 3333 } 3334 3335 const char *bpf_object__name(const struct bpf_object *obj) 3336 { 3337 return obj ? obj->path : ERR_PTR(-EINVAL); 3338 } 3339 3340 unsigned int bpf_object__kversion(const struct bpf_object *obj) 3341 { 3342 return obj ? obj->kern_version : 0; 3343 } 3344 3345 struct btf *bpf_object__btf(const struct bpf_object *obj) 3346 { 3347 return obj ? obj->btf : NULL; 3348 } 3349 3350 int bpf_object__btf_fd(const struct bpf_object *obj) 3351 { 3352 return obj->btf ? btf__fd(obj->btf) : -1; 3353 } 3354 3355 int bpf_object__set_priv(struct bpf_object *obj, void *priv, 3356 bpf_object_clear_priv_t clear_priv) 3357 { 3358 if (obj->priv && obj->clear_priv) 3359 obj->clear_priv(obj, obj->priv); 3360 3361 obj->priv = priv; 3362 obj->clear_priv = clear_priv; 3363 return 0; 3364 } 3365 3366 void *bpf_object__priv(const struct bpf_object *obj) 3367 { 3368 return obj ? obj->priv : ERR_PTR(-EINVAL); 3369 } 3370 3371 static struct bpf_program * 3372 __bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj, 3373 bool forward) 3374 { 3375 size_t nr_programs = obj->nr_programs; 3376 ssize_t idx; 3377 3378 if (!nr_programs) 3379 return NULL; 3380 3381 if (!p) 3382 /* Iter from the beginning */ 3383 return forward ? &obj->programs[0] : 3384 &obj->programs[nr_programs - 1]; 3385 3386 if (p->obj != obj) { 3387 pr_warning("error: program handler doesn't match object\n"); 3388 return NULL; 3389 } 3390 3391 idx = (p - obj->programs) + (forward ? 1 : -1); 3392 if (idx >= obj->nr_programs || idx < 0) 3393 return NULL; 3394 return &obj->programs[idx]; 3395 } 3396 3397 struct bpf_program * 3398 bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj) 3399 { 3400 struct bpf_program *prog = prev; 3401 3402 do { 3403 prog = __bpf_program__iter(prog, obj, true); 3404 } while (prog && bpf_program__is_function_storage(prog, obj)); 3405 3406 return prog; 3407 } 3408 3409 struct bpf_program * 3410 bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj) 3411 { 3412 struct bpf_program *prog = next; 3413 3414 do { 3415 prog = __bpf_program__iter(prog, obj, false); 3416 } while (prog && bpf_program__is_function_storage(prog, obj)); 3417 3418 return prog; 3419 } 3420 3421 int bpf_program__set_priv(struct bpf_program *prog, void *priv, 3422 bpf_program_clear_priv_t clear_priv) 3423 { 3424 if (prog->priv && prog->clear_priv) 3425 prog->clear_priv(prog, prog->priv); 3426 3427 prog->priv = priv; 3428 prog->clear_priv = clear_priv; 3429 return 0; 3430 } 3431 3432 void *bpf_program__priv(const struct bpf_program *prog) 3433 { 3434 return prog ? prog->priv : ERR_PTR(-EINVAL); 3435 } 3436 3437 void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex) 3438 { 3439 prog->prog_ifindex = ifindex; 3440 } 3441 3442 const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy) 3443 { 3444 const char *title; 3445 3446 title = prog->section_name; 3447 if (needs_copy) { 3448 title = strdup(title); 3449 if (!title) { 3450 pr_warning("failed to strdup program title\n"); 3451 return ERR_PTR(-ENOMEM); 3452 } 3453 } 3454 3455 return title; 3456 } 3457 3458 int bpf_program__fd(const struct bpf_program *prog) 3459 { 3460 return bpf_program__nth_fd(prog, 0); 3461 } 3462 3463 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, 3464 bpf_program_prep_t prep) 3465 { 3466 int *instances_fds; 3467 3468 if (nr_instances <= 0 || !prep) 3469 return -EINVAL; 3470 3471 if (prog->instances.nr > 0 || prog->instances.fds) { 3472 pr_warning("Can't set pre-processor after loading\n"); 3473 return -EINVAL; 3474 } 3475 3476 instances_fds = malloc(sizeof(int) * nr_instances); 3477 if (!instances_fds) { 3478 pr_warning("alloc memory failed for fds\n"); 3479 return -ENOMEM; 3480 } 3481 3482 /* fill all fd with -1 */ 3483 memset(instances_fds, -1, sizeof(int) * nr_instances); 3484 3485 prog->instances.nr = nr_instances; 3486 prog->instances.fds = instances_fds; 3487 prog->preprocessor = prep; 3488 return 0; 3489 } 3490 3491 int bpf_program__nth_fd(const struct bpf_program *prog, int n) 3492 { 3493 int fd; 3494 3495 if (!prog) 3496 return -EINVAL; 3497 3498 if (n >= prog->instances.nr || n < 0) { 3499 pr_warning("Can't get the %dth fd from program %s: only %d instances\n", 3500 n, prog->section_name, prog->instances.nr); 3501 return -EINVAL; 3502 } 3503 3504 fd = prog->instances.fds[n]; 3505 if (fd < 0) { 3506 pr_warning("%dth instance of program '%s' is invalid\n", 3507 n, prog->section_name); 3508 return -ENOENT; 3509 } 3510 3511 return fd; 3512 } 3513 3514 void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) 3515 { 3516 prog->type = type; 3517 } 3518 3519 static bool bpf_program__is_type(const struct bpf_program *prog, 3520 enum bpf_prog_type type) 3521 { 3522 return prog ? (prog->type == type) : false; 3523 } 3524 3525 #define BPF_PROG_TYPE_FNS(NAME, TYPE) \ 3526 int bpf_program__set_##NAME(struct bpf_program *prog) \ 3527 { \ 3528 if (!prog) \ 3529 return -EINVAL; \ 3530 bpf_program__set_type(prog, TYPE); \ 3531 return 0; \ 3532 } \ 3533 \ 3534 bool bpf_program__is_##NAME(const struct bpf_program *prog) \ 3535 { \ 3536 return bpf_program__is_type(prog, TYPE); \ 3537 } \ 3538 3539 BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER); 3540 BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE); 3541 BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS); 3542 BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT); 3543 BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT); 3544 BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT); 3545 BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP); 3546 BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT); 3547 3548 void bpf_program__set_expected_attach_type(struct bpf_program *prog, 3549 enum bpf_attach_type type) 3550 { 3551 prog->expected_attach_type = type; 3552 } 3553 3554 #define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, atype) \ 3555 { string, sizeof(string) - 1, ptype, eatype, is_attachable, atype } 3556 3557 /* Programs that can NOT be attached. */ 3558 #define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0) 3559 3560 /* Programs that can be attached. */ 3561 #define BPF_APROG_SEC(string, ptype, atype) \ 3562 BPF_PROG_SEC_IMPL(string, ptype, 0, 1, atype) 3563 3564 /* Programs that must specify expected attach type at load time. */ 3565 #define BPF_EAPROG_SEC(string, ptype, eatype) \ 3566 BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, eatype) 3567 3568 /* Programs that can be attached but attach type can't be identified by section 3569 * name. Kept for backward compatibility. 3570 */ 3571 #define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype) 3572 3573 static const struct { 3574 const char *sec; 3575 size_t len; 3576 enum bpf_prog_type prog_type; 3577 enum bpf_attach_type expected_attach_type; 3578 int is_attachable; 3579 enum bpf_attach_type attach_type; 3580 } section_names[] = { 3581 BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER), 3582 BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE), 3583 BPF_PROG_SEC("kretprobe/", BPF_PROG_TYPE_KPROBE), 3584 BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS), 3585 BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT), 3586 BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT), 3587 BPF_PROG_SEC("raw_tracepoint/", BPF_PROG_TYPE_RAW_TRACEPOINT), 3588 BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP), 3589 BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT), 3590 BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN), 3591 BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT), 3592 BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT), 3593 BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL), 3594 BPF_APROG_SEC("cgroup_skb/ingress", BPF_PROG_TYPE_CGROUP_SKB, 3595 BPF_CGROUP_INET_INGRESS), 3596 BPF_APROG_SEC("cgroup_skb/egress", BPF_PROG_TYPE_CGROUP_SKB, 3597 BPF_CGROUP_INET_EGRESS), 3598 BPF_APROG_COMPAT("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB), 3599 BPF_APROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK, 3600 BPF_CGROUP_INET_SOCK_CREATE), 3601 BPF_EAPROG_SEC("cgroup/post_bind4", BPF_PROG_TYPE_CGROUP_SOCK, 3602 BPF_CGROUP_INET4_POST_BIND), 3603 BPF_EAPROG_SEC("cgroup/post_bind6", BPF_PROG_TYPE_CGROUP_SOCK, 3604 BPF_CGROUP_INET6_POST_BIND), 3605 BPF_APROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE, 3606 BPF_CGROUP_DEVICE), 3607 BPF_APROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS, 3608 BPF_CGROUP_SOCK_OPS), 3609 BPF_APROG_SEC("sk_skb/stream_parser", BPF_PROG_TYPE_SK_SKB, 3610 BPF_SK_SKB_STREAM_PARSER), 3611 BPF_APROG_SEC("sk_skb/stream_verdict", BPF_PROG_TYPE_SK_SKB, 3612 BPF_SK_SKB_STREAM_VERDICT), 3613 BPF_APROG_COMPAT("sk_skb", BPF_PROG_TYPE_SK_SKB), 3614 BPF_APROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG, 3615 BPF_SK_MSG_VERDICT), 3616 BPF_APROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2, 3617 BPF_LIRC_MODE2), 3618 BPF_APROG_SEC("flow_dissector", BPF_PROG_TYPE_FLOW_DISSECTOR, 3619 BPF_FLOW_DISSECTOR), 3620 BPF_EAPROG_SEC("cgroup/bind4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3621 BPF_CGROUP_INET4_BIND), 3622 BPF_EAPROG_SEC("cgroup/bind6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3623 BPF_CGROUP_INET6_BIND), 3624 BPF_EAPROG_SEC("cgroup/connect4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3625 BPF_CGROUP_INET4_CONNECT), 3626 BPF_EAPROG_SEC("cgroup/connect6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3627 BPF_CGROUP_INET6_CONNECT), 3628 BPF_EAPROG_SEC("cgroup/sendmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3629 BPF_CGROUP_UDP4_SENDMSG), 3630 BPF_EAPROG_SEC("cgroup/sendmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3631 BPF_CGROUP_UDP6_SENDMSG), 3632 BPF_EAPROG_SEC("cgroup/recvmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3633 BPF_CGROUP_UDP4_RECVMSG), 3634 BPF_EAPROG_SEC("cgroup/recvmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR, 3635 BPF_CGROUP_UDP6_RECVMSG), 3636 BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL, 3637 BPF_CGROUP_SYSCTL), 3638 BPF_EAPROG_SEC("cgroup/getsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT, 3639 BPF_CGROUP_GETSOCKOPT), 3640 BPF_EAPROG_SEC("cgroup/setsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT, 3641 BPF_CGROUP_SETSOCKOPT), 3642 }; 3643 3644 #undef BPF_PROG_SEC_IMPL 3645 #undef BPF_PROG_SEC 3646 #undef BPF_APROG_SEC 3647 #undef BPF_EAPROG_SEC 3648 #undef BPF_APROG_COMPAT 3649 3650 #define MAX_TYPE_NAME_SIZE 32 3651 3652 static char *libbpf_get_type_names(bool attach_type) 3653 { 3654 int i, len = ARRAY_SIZE(section_names) * MAX_TYPE_NAME_SIZE; 3655 char *buf; 3656 3657 buf = malloc(len); 3658 if (!buf) 3659 return NULL; 3660 3661 buf[0] = '\0'; 3662 /* Forge string buf with all available names */ 3663 for (i = 0; i < ARRAY_SIZE(section_names); i++) { 3664 if (attach_type && !section_names[i].is_attachable) 3665 continue; 3666 3667 if (strlen(buf) + strlen(section_names[i].sec) + 2 > len) { 3668 free(buf); 3669 return NULL; 3670 } 3671 strcat(buf, " "); 3672 strcat(buf, section_names[i].sec); 3673 } 3674 3675 return buf; 3676 } 3677 3678 int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 3679 enum bpf_attach_type *expected_attach_type) 3680 { 3681 char *type_names; 3682 int i; 3683 3684 if (!name) 3685 return -EINVAL; 3686 3687 for (i = 0; i < ARRAY_SIZE(section_names); i++) { 3688 if (strncmp(name, section_names[i].sec, section_names[i].len)) 3689 continue; 3690 *prog_type = section_names[i].prog_type; 3691 *expected_attach_type = section_names[i].expected_attach_type; 3692 return 0; 3693 } 3694 pr_warning("failed to guess program type based on ELF section name '%s'\n", name); 3695 type_names = libbpf_get_type_names(false); 3696 if (type_names != NULL) { 3697 pr_info("supported section(type) names are:%s\n", type_names); 3698 free(type_names); 3699 } 3700 3701 return -EINVAL; 3702 } 3703 3704 int libbpf_attach_type_by_name(const char *name, 3705 enum bpf_attach_type *attach_type) 3706 { 3707 char *type_names; 3708 int i; 3709 3710 if (!name) 3711 return -EINVAL; 3712 3713 for (i = 0; i < ARRAY_SIZE(section_names); i++) { 3714 if (strncmp(name, section_names[i].sec, section_names[i].len)) 3715 continue; 3716 if (!section_names[i].is_attachable) 3717 return -EINVAL; 3718 *attach_type = section_names[i].attach_type; 3719 return 0; 3720 } 3721 pr_warning("failed to guess attach type based on ELF section name '%s'\n", name); 3722 type_names = libbpf_get_type_names(true); 3723 if (type_names != NULL) { 3724 pr_info("attachable section(type) names are:%s\n", type_names); 3725 free(type_names); 3726 } 3727 3728 return -EINVAL; 3729 } 3730 3731 static int 3732 bpf_program__identify_section(struct bpf_program *prog, 3733 enum bpf_prog_type *prog_type, 3734 enum bpf_attach_type *expected_attach_type) 3735 { 3736 return libbpf_prog_type_by_name(prog->section_name, prog_type, 3737 expected_attach_type); 3738 } 3739 3740 int bpf_map__fd(const struct bpf_map *map) 3741 { 3742 return map ? map->fd : -EINVAL; 3743 } 3744 3745 const struct bpf_map_def *bpf_map__def(const struct bpf_map *map) 3746 { 3747 return map ? &map->def : ERR_PTR(-EINVAL); 3748 } 3749 3750 const char *bpf_map__name(const struct bpf_map *map) 3751 { 3752 return map ? map->name : NULL; 3753 } 3754 3755 __u32 bpf_map__btf_key_type_id(const struct bpf_map *map) 3756 { 3757 return map ? map->btf_key_type_id : 0; 3758 } 3759 3760 __u32 bpf_map__btf_value_type_id(const struct bpf_map *map) 3761 { 3762 return map ? map->btf_value_type_id : 0; 3763 } 3764 3765 int bpf_map__set_priv(struct bpf_map *map, void *priv, 3766 bpf_map_clear_priv_t clear_priv) 3767 { 3768 if (!map) 3769 return -EINVAL; 3770 3771 if (map->priv) { 3772 if (map->clear_priv) 3773 map->clear_priv(map, map->priv); 3774 } 3775 3776 map->priv = priv; 3777 map->clear_priv = clear_priv; 3778 return 0; 3779 } 3780 3781 void *bpf_map__priv(const struct bpf_map *map) 3782 { 3783 return map ? map->priv : ERR_PTR(-EINVAL); 3784 } 3785 3786 bool bpf_map__is_offload_neutral(const struct bpf_map *map) 3787 { 3788 return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY; 3789 } 3790 3791 bool bpf_map__is_internal(const struct bpf_map *map) 3792 { 3793 return map->libbpf_type != LIBBPF_MAP_UNSPEC; 3794 } 3795 3796 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex) 3797 { 3798 map->map_ifindex = ifindex; 3799 } 3800 3801 int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd) 3802 { 3803 if (!bpf_map_type__is_map_in_map(map->def.type)) { 3804 pr_warning("error: unsupported map type\n"); 3805 return -EINVAL; 3806 } 3807 if (map->inner_map_fd != -1) { 3808 pr_warning("error: inner_map_fd already specified\n"); 3809 return -EINVAL; 3810 } 3811 map->inner_map_fd = fd; 3812 return 0; 3813 } 3814 3815 static struct bpf_map * 3816 __bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i) 3817 { 3818 ssize_t idx; 3819 struct bpf_map *s, *e; 3820 3821 if (!obj || !obj->maps) 3822 return NULL; 3823 3824 s = obj->maps; 3825 e = obj->maps + obj->nr_maps; 3826 3827 if ((m < s) || (m >= e)) { 3828 pr_warning("error in %s: map handler doesn't belong to object\n", 3829 __func__); 3830 return NULL; 3831 } 3832 3833 idx = (m - obj->maps) + i; 3834 if (idx >= obj->nr_maps || idx < 0) 3835 return NULL; 3836 return &obj->maps[idx]; 3837 } 3838 3839 struct bpf_map * 3840 bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj) 3841 { 3842 if (prev == NULL) 3843 return obj->maps; 3844 3845 return __bpf_map__iter(prev, obj, 1); 3846 } 3847 3848 struct bpf_map * 3849 bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj) 3850 { 3851 if (next == NULL) { 3852 if (!obj->nr_maps) 3853 return NULL; 3854 return obj->maps + obj->nr_maps - 1; 3855 } 3856 3857 return __bpf_map__iter(next, obj, -1); 3858 } 3859 3860 struct bpf_map * 3861 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name) 3862 { 3863 struct bpf_map *pos; 3864 3865 bpf_object__for_each_map(pos, obj) { 3866 if (pos->name && !strcmp(pos->name, name)) 3867 return pos; 3868 } 3869 return NULL; 3870 } 3871 3872 int 3873 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name) 3874 { 3875 return bpf_map__fd(bpf_object__find_map_by_name(obj, name)); 3876 } 3877 3878 struct bpf_map * 3879 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) 3880 { 3881 return ERR_PTR(-ENOTSUP); 3882 } 3883 3884 long libbpf_get_error(const void *ptr) 3885 { 3886 return PTR_ERR_OR_ZERO(ptr); 3887 } 3888 3889 int bpf_prog_load(const char *file, enum bpf_prog_type type, 3890 struct bpf_object **pobj, int *prog_fd) 3891 { 3892 struct bpf_prog_load_attr attr; 3893 3894 memset(&attr, 0, sizeof(struct bpf_prog_load_attr)); 3895 attr.file = file; 3896 attr.prog_type = type; 3897 attr.expected_attach_type = 0; 3898 3899 return bpf_prog_load_xattr(&attr, pobj, prog_fd); 3900 } 3901 3902 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 3903 struct bpf_object **pobj, int *prog_fd) 3904 { 3905 struct bpf_object_open_attr open_attr = {}; 3906 struct bpf_program *prog, *first_prog = NULL; 3907 enum bpf_attach_type expected_attach_type; 3908 enum bpf_prog_type prog_type; 3909 struct bpf_object *obj; 3910 struct bpf_map *map; 3911 int err; 3912 3913 if (!attr) 3914 return -EINVAL; 3915 if (!attr->file) 3916 return -EINVAL; 3917 3918 open_attr.file = attr->file; 3919 open_attr.prog_type = attr->prog_type; 3920 3921 obj = bpf_object__open_xattr(&open_attr); 3922 if (IS_ERR_OR_NULL(obj)) 3923 return -ENOENT; 3924 3925 bpf_object__for_each_program(prog, obj) { 3926 /* 3927 * If type is not specified, try to guess it based on 3928 * section name. 3929 */ 3930 prog_type = attr->prog_type; 3931 prog->prog_ifindex = attr->ifindex; 3932 expected_attach_type = attr->expected_attach_type; 3933 if (prog_type == BPF_PROG_TYPE_UNSPEC) { 3934 err = bpf_program__identify_section(prog, &prog_type, 3935 &expected_attach_type); 3936 if (err < 0) { 3937 bpf_object__close(obj); 3938 return -EINVAL; 3939 } 3940 } 3941 3942 bpf_program__set_type(prog, prog_type); 3943 bpf_program__set_expected_attach_type(prog, 3944 expected_attach_type); 3945 3946 prog->log_level = attr->log_level; 3947 prog->prog_flags = attr->prog_flags; 3948 if (!first_prog) 3949 first_prog = prog; 3950 } 3951 3952 bpf_object__for_each_map(map, obj) { 3953 if (!bpf_map__is_offload_neutral(map)) 3954 map->map_ifindex = attr->ifindex; 3955 } 3956 3957 if (!first_prog) { 3958 pr_warning("object file doesn't contain bpf program\n"); 3959 bpf_object__close(obj); 3960 return -ENOENT; 3961 } 3962 3963 err = bpf_object__load(obj); 3964 if (err) { 3965 bpf_object__close(obj); 3966 return -EINVAL; 3967 } 3968 3969 *pobj = obj; 3970 *prog_fd = bpf_program__fd(first_prog); 3971 return 0; 3972 } 3973 3974 struct bpf_link { 3975 int (*destroy)(struct bpf_link *link); 3976 }; 3977 3978 int bpf_link__destroy(struct bpf_link *link) 3979 { 3980 int err; 3981 3982 if (!link) 3983 return 0; 3984 3985 err = link->destroy(link); 3986 free(link); 3987 3988 return err; 3989 } 3990 3991 struct bpf_link_fd { 3992 struct bpf_link link; /* has to be at the top of struct */ 3993 int fd; /* hook FD */ 3994 }; 3995 3996 static int bpf_link__destroy_perf_event(struct bpf_link *link) 3997 { 3998 struct bpf_link_fd *l = (void *)link; 3999 int err; 4000 4001 err = ioctl(l->fd, PERF_EVENT_IOC_DISABLE, 0); 4002 if (err) 4003 err = -errno; 4004 4005 close(l->fd); 4006 return err; 4007 } 4008 4009 struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, 4010 int pfd) 4011 { 4012 char errmsg[STRERR_BUFSIZE]; 4013 struct bpf_link_fd *link; 4014 int prog_fd, err; 4015 4016 if (pfd < 0) { 4017 pr_warning("program '%s': invalid perf event FD %d\n", 4018 bpf_program__title(prog, false), pfd); 4019 return ERR_PTR(-EINVAL); 4020 } 4021 prog_fd = bpf_program__fd(prog); 4022 if (prog_fd < 0) { 4023 pr_warning("program '%s': can't attach BPF program w/o FD (did you load it?)\n", 4024 bpf_program__title(prog, false)); 4025 return ERR_PTR(-EINVAL); 4026 } 4027 4028 link = malloc(sizeof(*link)); 4029 if (!link) 4030 return ERR_PTR(-ENOMEM); 4031 link->link.destroy = &bpf_link__destroy_perf_event; 4032 link->fd = pfd; 4033 4034 if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) { 4035 err = -errno; 4036 free(link); 4037 pr_warning("program '%s': failed to attach to pfd %d: %s\n", 4038 bpf_program__title(prog, false), pfd, 4039 libbpf_strerror_r(err, errmsg, sizeof(errmsg))); 4040 return ERR_PTR(err); 4041 } 4042 if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) { 4043 err = -errno; 4044 free(link); 4045 pr_warning("program '%s': failed to enable pfd %d: %s\n", 4046 bpf_program__title(prog, false), pfd, 4047 libbpf_strerror_r(err, errmsg, sizeof(errmsg))); 4048 return ERR_PTR(err); 4049 } 4050 return (struct bpf_link *)link; 4051 } 4052 4053 /* 4054 * this function is expected to parse integer in the range of [0, 2^31-1] from 4055 * given file using scanf format string fmt. If actual parsed value is 4056 * negative, the result might be indistinguishable from error 4057 */ 4058 static int parse_uint_from_file(const char *file, const char *fmt) 4059 { 4060 char buf[STRERR_BUFSIZE]; 4061 int err, ret; 4062 FILE *f; 4063 4064 f = fopen(file, "r"); 4065 if (!f) { 4066 err = -errno; 4067 pr_debug("failed to open '%s': %s\n", file, 4068 libbpf_strerror_r(err, buf, sizeof(buf))); 4069 return err; 4070 } 4071 err = fscanf(f, fmt, &ret); 4072 if (err != 1) { 4073 err = err == EOF ? -EIO : -errno; 4074 pr_debug("failed to parse '%s': %s\n", file, 4075 libbpf_strerror_r(err, buf, sizeof(buf))); 4076 fclose(f); 4077 return err; 4078 } 4079 fclose(f); 4080 return ret; 4081 } 4082 4083 static int determine_kprobe_perf_type(void) 4084 { 4085 const char *file = "/sys/bus/event_source/devices/kprobe/type"; 4086 4087 return parse_uint_from_file(file, "%d\n"); 4088 } 4089 4090 static int determine_uprobe_perf_type(void) 4091 { 4092 const char *file = "/sys/bus/event_source/devices/uprobe/type"; 4093 4094 return parse_uint_from_file(file, "%d\n"); 4095 } 4096 4097 static int determine_kprobe_retprobe_bit(void) 4098 { 4099 const char *file = "/sys/bus/event_source/devices/kprobe/format/retprobe"; 4100 4101 return parse_uint_from_file(file, "config:%d\n"); 4102 } 4103 4104 static int determine_uprobe_retprobe_bit(void) 4105 { 4106 const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe"; 4107 4108 return parse_uint_from_file(file, "config:%d\n"); 4109 } 4110 4111 static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, 4112 uint64_t offset, int pid) 4113 { 4114 struct perf_event_attr attr = {}; 4115 char errmsg[STRERR_BUFSIZE]; 4116 int type, pfd, err; 4117 4118 type = uprobe ? determine_uprobe_perf_type() 4119 : determine_kprobe_perf_type(); 4120 if (type < 0) { 4121 pr_warning("failed to determine %s perf type: %s\n", 4122 uprobe ? "uprobe" : "kprobe", 4123 libbpf_strerror_r(type, errmsg, sizeof(errmsg))); 4124 return type; 4125 } 4126 if (retprobe) { 4127 int bit = uprobe ? determine_uprobe_retprobe_bit() 4128 : determine_kprobe_retprobe_bit(); 4129 4130 if (bit < 0) { 4131 pr_warning("failed to determine %s retprobe bit: %s\n", 4132 uprobe ? "uprobe" : "kprobe", 4133 libbpf_strerror_r(bit, errmsg, 4134 sizeof(errmsg))); 4135 return bit; 4136 } 4137 attr.config |= 1 << bit; 4138 } 4139 attr.size = sizeof(attr); 4140 attr.type = type; 4141 attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */ 4142 attr.config2 = offset; /* kprobe_addr or probe_offset */ 4143 4144 /* pid filter is meaningful only for uprobes */ 4145 pfd = syscall(__NR_perf_event_open, &attr, 4146 pid < 0 ? -1 : pid /* pid */, 4147 pid == -1 ? 0 : -1 /* cpu */, 4148 -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); 4149 if (pfd < 0) { 4150 err = -errno; 4151 pr_warning("%s perf_event_open() failed: %s\n", 4152 uprobe ? "uprobe" : "kprobe", 4153 libbpf_strerror_r(err, errmsg, sizeof(errmsg))); 4154 return err; 4155 } 4156 return pfd; 4157 } 4158 4159 struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog, 4160 bool retprobe, 4161 const char *func_name) 4162 { 4163 char errmsg[STRERR_BUFSIZE]; 4164 struct bpf_link *link; 4165 int pfd, err; 4166 4167 pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name, 4168 0 /* offset */, -1 /* pid */); 4169 if (pfd < 0) { 4170 pr_warning("program '%s': failed to create %s '%s' perf event: %s\n", 4171 bpf_program__title(prog, false), 4172 retprobe ? "kretprobe" : "kprobe", func_name, 4173 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); 4174 return ERR_PTR(pfd); 4175 } 4176 link = bpf_program__attach_perf_event(prog, pfd); 4177 if (IS_ERR(link)) { 4178 close(pfd); 4179 err = PTR_ERR(link); 4180 pr_warning("program '%s': failed to attach to %s '%s': %s\n", 4181 bpf_program__title(prog, false), 4182 retprobe ? "kretprobe" : "kprobe", func_name, 4183 libbpf_strerror_r(err, errmsg, sizeof(errmsg))); 4184 return link; 4185 } 4186 return link; 4187 } 4188 4189 struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog, 4190 bool retprobe, pid_t pid, 4191 const char *binary_path, 4192 size_t func_offset) 4193 { 4194 char errmsg[STRERR_BUFSIZE]; 4195 struct bpf_link *link; 4196 int pfd, err; 4197 4198 pfd = perf_event_open_probe(true /* uprobe */, retprobe, 4199 binary_path, func_offset, pid); 4200 if (pfd < 0) { 4201 pr_warning("program '%s': failed to create %s '%s:0x%zx' perf event: %s\n", 4202 bpf_program__title(prog, false), 4203 retprobe ? "uretprobe" : "uprobe", 4204 binary_path, func_offset, 4205 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); 4206 return ERR_PTR(pfd); 4207 } 4208 link = bpf_program__attach_perf_event(prog, pfd); 4209 if (IS_ERR(link)) { 4210 close(pfd); 4211 err = PTR_ERR(link); 4212 pr_warning("program '%s': failed to attach to %s '%s:0x%zx': %s\n", 4213 bpf_program__title(prog, false), 4214 retprobe ? "uretprobe" : "uprobe", 4215 binary_path, func_offset, 4216 libbpf_strerror_r(err, errmsg, sizeof(errmsg))); 4217 return link; 4218 } 4219 return link; 4220 } 4221 4222 static int determine_tracepoint_id(const char *tp_category, 4223 const char *tp_name) 4224 { 4225 char file[PATH_MAX]; 4226 int ret; 4227 4228 ret = snprintf(file, sizeof(file), 4229 "/sys/kernel/debug/tracing/events/%s/%s/id", 4230 tp_category, tp_name); 4231 if (ret < 0) 4232 return -errno; 4233 if (ret >= sizeof(file)) { 4234 pr_debug("tracepoint %s/%s path is too long\n", 4235 tp_category, tp_name); 4236 return -E2BIG; 4237 } 4238 return parse_uint_from_file(file, "%d\n"); 4239 } 4240 4241 static int perf_event_open_tracepoint(const char *tp_category, 4242 const char *tp_name) 4243 { 4244 struct perf_event_attr attr = {}; 4245 char errmsg[STRERR_BUFSIZE]; 4246 int tp_id, pfd, err; 4247 4248 tp_id = determine_tracepoint_id(tp_category, tp_name); 4249 if (tp_id < 0) { 4250 pr_warning("failed to determine tracepoint '%s/%s' perf event ID: %s\n", 4251 tp_category, tp_name, 4252 libbpf_strerror_r(tp_id, errmsg, sizeof(errmsg))); 4253 return tp_id; 4254 } 4255 4256 attr.type = PERF_TYPE_TRACEPOINT; 4257 attr.size = sizeof(attr); 4258 attr.config = tp_id; 4259 4260 pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */, 4261 -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); 4262 if (pfd < 0) { 4263 err = -errno; 4264 pr_warning("tracepoint '%s/%s' perf_event_open() failed: %s\n", 4265 tp_category, tp_name, 4266 libbpf_strerror_r(err, errmsg, sizeof(errmsg))); 4267 return err; 4268 } 4269 return pfd; 4270 } 4271 4272 struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog, 4273 const char *tp_category, 4274 const char *tp_name) 4275 { 4276 char errmsg[STRERR_BUFSIZE]; 4277 struct bpf_link *link; 4278 int pfd, err; 4279 4280 pfd = perf_event_open_tracepoint(tp_category, tp_name); 4281 if (pfd < 0) { 4282 pr_warning("program '%s': failed to create tracepoint '%s/%s' perf event: %s\n", 4283 bpf_program__title(prog, false), 4284 tp_category, tp_name, 4285 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); 4286 return ERR_PTR(pfd); 4287 } 4288 link = bpf_program__attach_perf_event(prog, pfd); 4289 if (IS_ERR(link)) { 4290 close(pfd); 4291 err = PTR_ERR(link); 4292 pr_warning("program '%s': failed to attach to tracepoint '%s/%s': %s\n", 4293 bpf_program__title(prog, false), 4294 tp_category, tp_name, 4295 libbpf_strerror_r(err, errmsg, sizeof(errmsg))); 4296 return link; 4297 } 4298 return link; 4299 } 4300 4301 static int bpf_link__destroy_fd(struct bpf_link *link) 4302 { 4303 struct bpf_link_fd *l = (void *)link; 4304 4305 return close(l->fd); 4306 } 4307 4308 struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog, 4309 const char *tp_name) 4310 { 4311 char errmsg[STRERR_BUFSIZE]; 4312 struct bpf_link_fd *link; 4313 int prog_fd, pfd; 4314 4315 prog_fd = bpf_program__fd(prog); 4316 if (prog_fd < 0) { 4317 pr_warning("program '%s': can't attach before loaded\n", 4318 bpf_program__title(prog, false)); 4319 return ERR_PTR(-EINVAL); 4320 } 4321 4322 link = malloc(sizeof(*link)); 4323 if (!link) 4324 return ERR_PTR(-ENOMEM); 4325 link->link.destroy = &bpf_link__destroy_fd; 4326 4327 pfd = bpf_raw_tracepoint_open(tp_name, prog_fd); 4328 if (pfd < 0) { 4329 pfd = -errno; 4330 free(link); 4331 pr_warning("program '%s': failed to attach to raw tracepoint '%s': %s\n", 4332 bpf_program__title(prog, false), tp_name, 4333 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); 4334 return ERR_PTR(pfd); 4335 } 4336 link->fd = pfd; 4337 return (struct bpf_link *)link; 4338 } 4339 4340 enum bpf_perf_event_ret 4341 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, 4342 void **copy_mem, size_t *copy_size, 4343 bpf_perf_event_print_t fn, void *private_data) 4344 { 4345 struct perf_event_mmap_page *header = mmap_mem; 4346 __u64 data_head = ring_buffer_read_head(header); 4347 __u64 data_tail = header->data_tail; 4348 void *base = ((__u8 *)header) + page_size; 4349 int ret = LIBBPF_PERF_EVENT_CONT; 4350 struct perf_event_header *ehdr; 4351 size_t ehdr_size; 4352 4353 while (data_head != data_tail) { 4354 ehdr = base + (data_tail & (mmap_size - 1)); 4355 ehdr_size = ehdr->size; 4356 4357 if (((void *)ehdr) + ehdr_size > base + mmap_size) { 4358 void *copy_start = ehdr; 4359 size_t len_first = base + mmap_size - copy_start; 4360 size_t len_secnd = ehdr_size - len_first; 4361 4362 if (*copy_size < ehdr_size) { 4363 free(*copy_mem); 4364 *copy_mem = malloc(ehdr_size); 4365 if (!*copy_mem) { 4366 *copy_size = 0; 4367 ret = LIBBPF_PERF_EVENT_ERROR; 4368 break; 4369 } 4370 *copy_size = ehdr_size; 4371 } 4372 4373 memcpy(*copy_mem, copy_start, len_first); 4374 memcpy(*copy_mem + len_first, base, len_secnd); 4375 ehdr = *copy_mem; 4376 } 4377 4378 ret = fn(ehdr, private_data); 4379 data_tail += ehdr_size; 4380 if (ret != LIBBPF_PERF_EVENT_CONT) 4381 break; 4382 } 4383 4384 ring_buffer_write_tail(header, data_tail); 4385 return ret; 4386 } 4387 4388 struct perf_buffer; 4389 4390 struct perf_buffer_params { 4391 struct perf_event_attr *attr; 4392 /* if event_cb is specified, it takes precendence */ 4393 perf_buffer_event_fn event_cb; 4394 /* sample_cb and lost_cb are higher-level common-case callbacks */ 4395 perf_buffer_sample_fn sample_cb; 4396 perf_buffer_lost_fn lost_cb; 4397 void *ctx; 4398 int cpu_cnt; 4399 int *cpus; 4400 int *map_keys; 4401 }; 4402 4403 struct perf_cpu_buf { 4404 struct perf_buffer *pb; 4405 void *base; /* mmap()'ed memory */ 4406 void *buf; /* for reconstructing segmented data */ 4407 size_t buf_size; 4408 int fd; 4409 int cpu; 4410 int map_key; 4411 }; 4412 4413 struct perf_buffer { 4414 perf_buffer_event_fn event_cb; 4415 perf_buffer_sample_fn sample_cb; 4416 perf_buffer_lost_fn lost_cb; 4417 void *ctx; /* passed into callbacks */ 4418 4419 size_t page_size; 4420 size_t mmap_size; 4421 struct perf_cpu_buf **cpu_bufs; 4422 struct epoll_event *events; 4423 int cpu_cnt; 4424 int epoll_fd; /* perf event FD */ 4425 int map_fd; /* BPF_MAP_TYPE_PERF_EVENT_ARRAY BPF map FD */ 4426 }; 4427 4428 static void perf_buffer__free_cpu_buf(struct perf_buffer *pb, 4429 struct perf_cpu_buf *cpu_buf) 4430 { 4431 if (!cpu_buf) 4432 return; 4433 if (cpu_buf->base && 4434 munmap(cpu_buf->base, pb->mmap_size + pb->page_size)) 4435 pr_warning("failed to munmap cpu_buf #%d\n", cpu_buf->cpu); 4436 if (cpu_buf->fd >= 0) { 4437 ioctl(cpu_buf->fd, PERF_EVENT_IOC_DISABLE, 0); 4438 close(cpu_buf->fd); 4439 } 4440 free(cpu_buf->buf); 4441 free(cpu_buf); 4442 } 4443 4444 void perf_buffer__free(struct perf_buffer *pb) 4445 { 4446 int i; 4447 4448 if (!pb) 4449 return; 4450 if (pb->cpu_bufs) { 4451 for (i = 0; i < pb->cpu_cnt && pb->cpu_bufs[i]; i++) { 4452 struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i]; 4453 4454 bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key); 4455 perf_buffer__free_cpu_buf(pb, cpu_buf); 4456 } 4457 free(pb->cpu_bufs); 4458 } 4459 if (pb->epoll_fd >= 0) 4460 close(pb->epoll_fd); 4461 free(pb->events); 4462 free(pb); 4463 } 4464 4465 static struct perf_cpu_buf * 4466 perf_buffer__open_cpu_buf(struct perf_buffer *pb, struct perf_event_attr *attr, 4467 int cpu, int map_key) 4468 { 4469 struct perf_cpu_buf *cpu_buf; 4470 char msg[STRERR_BUFSIZE]; 4471 int err; 4472 4473 cpu_buf = calloc(1, sizeof(*cpu_buf)); 4474 if (!cpu_buf) 4475 return ERR_PTR(-ENOMEM); 4476 4477 cpu_buf->pb = pb; 4478 cpu_buf->cpu = cpu; 4479 cpu_buf->map_key = map_key; 4480 4481 cpu_buf->fd = syscall(__NR_perf_event_open, attr, -1 /* pid */, cpu, 4482 -1, PERF_FLAG_FD_CLOEXEC); 4483 if (cpu_buf->fd < 0) { 4484 err = -errno; 4485 pr_warning("failed to open perf buffer event on cpu #%d: %s\n", 4486 cpu, libbpf_strerror_r(err, msg, sizeof(msg))); 4487 goto error; 4488 } 4489 4490 cpu_buf->base = mmap(NULL, pb->mmap_size + pb->page_size, 4491 PROT_READ | PROT_WRITE, MAP_SHARED, 4492 cpu_buf->fd, 0); 4493 if (cpu_buf->base == MAP_FAILED) { 4494 cpu_buf->base = NULL; 4495 err = -errno; 4496 pr_warning("failed to mmap perf buffer on cpu #%d: %s\n", 4497 cpu, libbpf_strerror_r(err, msg, sizeof(msg))); 4498 goto error; 4499 } 4500 4501 if (ioctl(cpu_buf->fd, PERF_EVENT_IOC_ENABLE, 0) < 0) { 4502 err = -errno; 4503 pr_warning("failed to enable perf buffer event on cpu #%d: %s\n", 4504 cpu, libbpf_strerror_r(err, msg, sizeof(msg))); 4505 goto error; 4506 } 4507 4508 return cpu_buf; 4509 4510 error: 4511 perf_buffer__free_cpu_buf(pb, cpu_buf); 4512 return (struct perf_cpu_buf *)ERR_PTR(err); 4513 } 4514 4515 static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, 4516 struct perf_buffer_params *p); 4517 4518 struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt, 4519 const struct perf_buffer_opts *opts) 4520 { 4521 struct perf_buffer_params p = {}; 4522 struct perf_event_attr attr = { 0, }; 4523 4524 attr.config = PERF_COUNT_SW_BPF_OUTPUT, 4525 attr.type = PERF_TYPE_SOFTWARE; 4526 attr.sample_type = PERF_SAMPLE_RAW; 4527 attr.sample_period = 1; 4528 attr.wakeup_events = 1; 4529 4530 p.attr = &attr; 4531 p.sample_cb = opts ? opts->sample_cb : NULL; 4532 p.lost_cb = opts ? opts->lost_cb : NULL; 4533 p.ctx = opts ? opts->ctx : NULL; 4534 4535 return __perf_buffer__new(map_fd, page_cnt, &p); 4536 } 4537 4538 struct perf_buffer * 4539 perf_buffer__new_raw(int map_fd, size_t page_cnt, 4540 const struct perf_buffer_raw_opts *opts) 4541 { 4542 struct perf_buffer_params p = {}; 4543 4544 p.attr = opts->attr; 4545 p.event_cb = opts->event_cb; 4546 p.ctx = opts->ctx; 4547 p.cpu_cnt = opts->cpu_cnt; 4548 p.cpus = opts->cpus; 4549 p.map_keys = opts->map_keys; 4550 4551 return __perf_buffer__new(map_fd, page_cnt, &p); 4552 } 4553 4554 static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, 4555 struct perf_buffer_params *p) 4556 { 4557 struct bpf_map_info map = {}; 4558 char msg[STRERR_BUFSIZE]; 4559 struct perf_buffer *pb; 4560 __u32 map_info_len; 4561 int err, i; 4562 4563 if (page_cnt & (page_cnt - 1)) { 4564 pr_warning("page count should be power of two, but is %zu\n", 4565 page_cnt); 4566 return ERR_PTR(-EINVAL); 4567 } 4568 4569 map_info_len = sizeof(map); 4570 err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len); 4571 if (err) { 4572 err = -errno; 4573 pr_warning("failed to get map info for map FD %d: %s\n", 4574 map_fd, libbpf_strerror_r(err, msg, sizeof(msg))); 4575 return ERR_PTR(err); 4576 } 4577 4578 if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) { 4579 pr_warning("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n", 4580 map.name); 4581 return ERR_PTR(-EINVAL); 4582 } 4583 4584 pb = calloc(1, sizeof(*pb)); 4585 if (!pb) 4586 return ERR_PTR(-ENOMEM); 4587 4588 pb->event_cb = p->event_cb; 4589 pb->sample_cb = p->sample_cb; 4590 pb->lost_cb = p->lost_cb; 4591 pb->ctx = p->ctx; 4592 4593 pb->page_size = getpagesize(); 4594 pb->mmap_size = pb->page_size * page_cnt; 4595 pb->map_fd = map_fd; 4596 4597 pb->epoll_fd = epoll_create1(EPOLL_CLOEXEC); 4598 if (pb->epoll_fd < 0) { 4599 err = -errno; 4600 pr_warning("failed to create epoll instance: %s\n", 4601 libbpf_strerror_r(err, msg, sizeof(msg))); 4602 goto error; 4603 } 4604 4605 if (p->cpu_cnt > 0) { 4606 pb->cpu_cnt = p->cpu_cnt; 4607 } else { 4608 pb->cpu_cnt = libbpf_num_possible_cpus(); 4609 if (pb->cpu_cnt < 0) { 4610 err = pb->cpu_cnt; 4611 goto error; 4612 } 4613 if (map.max_entries < pb->cpu_cnt) 4614 pb->cpu_cnt = map.max_entries; 4615 } 4616 4617 pb->events = calloc(pb->cpu_cnt, sizeof(*pb->events)); 4618 if (!pb->events) { 4619 err = -ENOMEM; 4620 pr_warning("failed to allocate events: out of memory\n"); 4621 goto error; 4622 } 4623 pb->cpu_bufs = calloc(pb->cpu_cnt, sizeof(*pb->cpu_bufs)); 4624 if (!pb->cpu_bufs) { 4625 err = -ENOMEM; 4626 pr_warning("failed to allocate buffers: out of memory\n"); 4627 goto error; 4628 } 4629 4630 for (i = 0; i < pb->cpu_cnt; i++) { 4631 struct perf_cpu_buf *cpu_buf; 4632 int cpu, map_key; 4633 4634 cpu = p->cpu_cnt > 0 ? p->cpus[i] : i; 4635 map_key = p->cpu_cnt > 0 ? p->map_keys[i] : i; 4636 4637 cpu_buf = perf_buffer__open_cpu_buf(pb, p->attr, cpu, map_key); 4638 if (IS_ERR(cpu_buf)) { 4639 err = PTR_ERR(cpu_buf); 4640 goto error; 4641 } 4642 4643 pb->cpu_bufs[i] = cpu_buf; 4644 4645 err = bpf_map_update_elem(pb->map_fd, &map_key, 4646 &cpu_buf->fd, 0); 4647 if (err) { 4648 err = -errno; 4649 pr_warning("failed to set cpu #%d, key %d -> perf FD %d: %s\n", 4650 cpu, map_key, cpu_buf->fd, 4651 libbpf_strerror_r(err, msg, sizeof(msg))); 4652 goto error; 4653 } 4654 4655 pb->events[i].events = EPOLLIN; 4656 pb->events[i].data.ptr = cpu_buf; 4657 if (epoll_ctl(pb->epoll_fd, EPOLL_CTL_ADD, cpu_buf->fd, 4658 &pb->events[i]) < 0) { 4659 err = -errno; 4660 pr_warning("failed to epoll_ctl cpu #%d perf FD %d: %s\n", 4661 cpu, cpu_buf->fd, 4662 libbpf_strerror_r(err, msg, sizeof(msg))); 4663 goto error; 4664 } 4665 } 4666 4667 return pb; 4668 4669 error: 4670 if (pb) 4671 perf_buffer__free(pb); 4672 return ERR_PTR(err); 4673 } 4674 4675 struct perf_sample_raw { 4676 struct perf_event_header header; 4677 uint32_t size; 4678 char data[0]; 4679 }; 4680 4681 struct perf_sample_lost { 4682 struct perf_event_header header; 4683 uint64_t id; 4684 uint64_t lost; 4685 uint64_t sample_id; 4686 }; 4687 4688 static enum bpf_perf_event_ret 4689 perf_buffer__process_record(struct perf_event_header *e, void *ctx) 4690 { 4691 struct perf_cpu_buf *cpu_buf = ctx; 4692 struct perf_buffer *pb = cpu_buf->pb; 4693 void *data = e; 4694 4695 /* user wants full control over parsing perf event */ 4696 if (pb->event_cb) 4697 return pb->event_cb(pb->ctx, cpu_buf->cpu, e); 4698 4699 switch (e->type) { 4700 case PERF_RECORD_SAMPLE: { 4701 struct perf_sample_raw *s = data; 4702 4703 if (pb->sample_cb) 4704 pb->sample_cb(pb->ctx, cpu_buf->cpu, s->data, s->size); 4705 break; 4706 } 4707 case PERF_RECORD_LOST: { 4708 struct perf_sample_lost *s = data; 4709 4710 if (pb->lost_cb) 4711 pb->lost_cb(pb->ctx, cpu_buf->cpu, s->lost); 4712 break; 4713 } 4714 default: 4715 pr_warning("unknown perf sample type %d\n", e->type); 4716 return LIBBPF_PERF_EVENT_ERROR; 4717 } 4718 return LIBBPF_PERF_EVENT_CONT; 4719 } 4720 4721 static int perf_buffer__process_records(struct perf_buffer *pb, 4722 struct perf_cpu_buf *cpu_buf) 4723 { 4724 enum bpf_perf_event_ret ret; 4725 4726 ret = bpf_perf_event_read_simple(cpu_buf->base, pb->mmap_size, 4727 pb->page_size, &cpu_buf->buf, 4728 &cpu_buf->buf_size, 4729 perf_buffer__process_record, cpu_buf); 4730 if (ret != LIBBPF_PERF_EVENT_CONT) 4731 return ret; 4732 return 0; 4733 } 4734 4735 int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms) 4736 { 4737 int i, cnt, err; 4738 4739 cnt = epoll_wait(pb->epoll_fd, pb->events, pb->cpu_cnt, timeout_ms); 4740 for (i = 0; i < cnt; i++) { 4741 struct perf_cpu_buf *cpu_buf = pb->events[i].data.ptr; 4742 4743 err = perf_buffer__process_records(pb, cpu_buf); 4744 if (err) { 4745 pr_warning("error while processing records: %d\n", err); 4746 return err; 4747 } 4748 } 4749 return cnt < 0 ? -errno : cnt; 4750 } 4751 4752 struct bpf_prog_info_array_desc { 4753 int array_offset; /* e.g. offset of jited_prog_insns */ 4754 int count_offset; /* e.g. offset of jited_prog_len */ 4755 int size_offset; /* > 0: offset of rec size, 4756 * < 0: fix size of -size_offset 4757 */ 4758 }; 4759 4760 static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = { 4761 [BPF_PROG_INFO_JITED_INSNS] = { 4762 offsetof(struct bpf_prog_info, jited_prog_insns), 4763 offsetof(struct bpf_prog_info, jited_prog_len), 4764 -1, 4765 }, 4766 [BPF_PROG_INFO_XLATED_INSNS] = { 4767 offsetof(struct bpf_prog_info, xlated_prog_insns), 4768 offsetof(struct bpf_prog_info, xlated_prog_len), 4769 -1, 4770 }, 4771 [BPF_PROG_INFO_MAP_IDS] = { 4772 offsetof(struct bpf_prog_info, map_ids), 4773 offsetof(struct bpf_prog_info, nr_map_ids), 4774 -(int)sizeof(__u32), 4775 }, 4776 [BPF_PROG_INFO_JITED_KSYMS] = { 4777 offsetof(struct bpf_prog_info, jited_ksyms), 4778 offsetof(struct bpf_prog_info, nr_jited_ksyms), 4779 -(int)sizeof(__u64), 4780 }, 4781 [BPF_PROG_INFO_JITED_FUNC_LENS] = { 4782 offsetof(struct bpf_prog_info, jited_func_lens), 4783 offsetof(struct bpf_prog_info, nr_jited_func_lens), 4784 -(int)sizeof(__u32), 4785 }, 4786 [BPF_PROG_INFO_FUNC_INFO] = { 4787 offsetof(struct bpf_prog_info, func_info), 4788 offsetof(struct bpf_prog_info, nr_func_info), 4789 offsetof(struct bpf_prog_info, func_info_rec_size), 4790 }, 4791 [BPF_PROG_INFO_LINE_INFO] = { 4792 offsetof(struct bpf_prog_info, line_info), 4793 offsetof(struct bpf_prog_info, nr_line_info), 4794 offsetof(struct bpf_prog_info, line_info_rec_size), 4795 }, 4796 [BPF_PROG_INFO_JITED_LINE_INFO] = { 4797 offsetof(struct bpf_prog_info, jited_line_info), 4798 offsetof(struct bpf_prog_info, nr_jited_line_info), 4799 offsetof(struct bpf_prog_info, jited_line_info_rec_size), 4800 }, 4801 [BPF_PROG_INFO_PROG_TAGS] = { 4802 offsetof(struct bpf_prog_info, prog_tags), 4803 offsetof(struct bpf_prog_info, nr_prog_tags), 4804 -(int)sizeof(__u8) * BPF_TAG_SIZE, 4805 }, 4806 4807 }; 4808 4809 static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info, int offset) 4810 { 4811 __u32 *array = (__u32 *)info; 4812 4813 if (offset >= 0) 4814 return array[offset / sizeof(__u32)]; 4815 return -(int)offset; 4816 } 4817 4818 static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info, int offset) 4819 { 4820 __u64 *array = (__u64 *)info; 4821 4822 if (offset >= 0) 4823 return array[offset / sizeof(__u64)]; 4824 return -(int)offset; 4825 } 4826 4827 static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset, 4828 __u32 val) 4829 { 4830 __u32 *array = (__u32 *)info; 4831 4832 if (offset >= 0) 4833 array[offset / sizeof(__u32)] = val; 4834 } 4835 4836 static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset, 4837 __u64 val) 4838 { 4839 __u64 *array = (__u64 *)info; 4840 4841 if (offset >= 0) 4842 array[offset / sizeof(__u64)] = val; 4843 } 4844 4845 struct bpf_prog_info_linear * 4846 bpf_program__get_prog_info_linear(int fd, __u64 arrays) 4847 { 4848 struct bpf_prog_info_linear *info_linear; 4849 struct bpf_prog_info info = {}; 4850 __u32 info_len = sizeof(info); 4851 __u32 data_len = 0; 4852 int i, err; 4853 void *ptr; 4854 4855 if (arrays >> BPF_PROG_INFO_LAST_ARRAY) 4856 return ERR_PTR(-EINVAL); 4857 4858 /* step 1: get array dimensions */ 4859 err = bpf_obj_get_info_by_fd(fd, &info, &info_len); 4860 if (err) { 4861 pr_debug("can't get prog info: %s", strerror(errno)); 4862 return ERR_PTR(-EFAULT); 4863 } 4864 4865 /* step 2: calculate total size of all arrays */ 4866 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { 4867 bool include_array = (arrays & (1UL << i)) > 0; 4868 struct bpf_prog_info_array_desc *desc; 4869 __u32 count, size; 4870 4871 desc = bpf_prog_info_array_desc + i; 4872 4873 /* kernel is too old to support this field */ 4874 if (info_len < desc->array_offset + sizeof(__u32) || 4875 info_len < desc->count_offset + sizeof(__u32) || 4876 (desc->size_offset > 0 && info_len < desc->size_offset)) 4877 include_array = false; 4878 4879 if (!include_array) { 4880 arrays &= ~(1UL << i); /* clear the bit */ 4881 continue; 4882 } 4883 4884 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset); 4885 size = bpf_prog_info_read_offset_u32(&info, desc->size_offset); 4886 4887 data_len += count * size; 4888 } 4889 4890 /* step 3: allocate continuous memory */ 4891 data_len = roundup(data_len, sizeof(__u64)); 4892 info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len); 4893 if (!info_linear) 4894 return ERR_PTR(-ENOMEM); 4895 4896 /* step 4: fill data to info_linear->info */ 4897 info_linear->arrays = arrays; 4898 memset(&info_linear->info, 0, sizeof(info)); 4899 ptr = info_linear->data; 4900 4901 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { 4902 struct bpf_prog_info_array_desc *desc; 4903 __u32 count, size; 4904 4905 if ((arrays & (1UL << i)) == 0) 4906 continue; 4907 4908 desc = bpf_prog_info_array_desc + i; 4909 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset); 4910 size = bpf_prog_info_read_offset_u32(&info, desc->size_offset); 4911 bpf_prog_info_set_offset_u32(&info_linear->info, 4912 desc->count_offset, count); 4913 bpf_prog_info_set_offset_u32(&info_linear->info, 4914 desc->size_offset, size); 4915 bpf_prog_info_set_offset_u64(&info_linear->info, 4916 desc->array_offset, 4917 ptr_to_u64(ptr)); 4918 ptr += count * size; 4919 } 4920 4921 /* step 5: call syscall again to get required arrays */ 4922 err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len); 4923 if (err) { 4924 pr_debug("can't get prog info: %s", strerror(errno)); 4925 free(info_linear); 4926 return ERR_PTR(-EFAULT); 4927 } 4928 4929 /* step 6: verify the data */ 4930 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { 4931 struct bpf_prog_info_array_desc *desc; 4932 __u32 v1, v2; 4933 4934 if ((arrays & (1UL << i)) == 0) 4935 continue; 4936 4937 desc = bpf_prog_info_array_desc + i; 4938 v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset); 4939 v2 = bpf_prog_info_read_offset_u32(&info_linear->info, 4940 desc->count_offset); 4941 if (v1 != v2) 4942 pr_warning("%s: mismatch in element count\n", __func__); 4943 4944 v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset); 4945 v2 = bpf_prog_info_read_offset_u32(&info_linear->info, 4946 desc->size_offset); 4947 if (v1 != v2) 4948 pr_warning("%s: mismatch in rec size\n", __func__); 4949 } 4950 4951 /* step 7: update info_len and data_len */ 4952 info_linear->info_len = sizeof(struct bpf_prog_info); 4953 info_linear->data_len = data_len; 4954 4955 return info_linear; 4956 } 4957 4958 void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear) 4959 { 4960 int i; 4961 4962 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { 4963 struct bpf_prog_info_array_desc *desc; 4964 __u64 addr, offs; 4965 4966 if ((info_linear->arrays & (1UL << i)) == 0) 4967 continue; 4968 4969 desc = bpf_prog_info_array_desc + i; 4970 addr = bpf_prog_info_read_offset_u64(&info_linear->info, 4971 desc->array_offset); 4972 offs = addr - ptr_to_u64(info_linear->data); 4973 bpf_prog_info_set_offset_u64(&info_linear->info, 4974 desc->array_offset, offs); 4975 } 4976 } 4977 4978 void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear) 4979 { 4980 int i; 4981 4982 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { 4983 struct bpf_prog_info_array_desc *desc; 4984 __u64 addr, offs; 4985 4986 if ((info_linear->arrays & (1UL << i)) == 0) 4987 continue; 4988 4989 desc = bpf_prog_info_array_desc + i; 4990 offs = bpf_prog_info_read_offset_u64(&info_linear->info, 4991 desc->array_offset); 4992 addr = offs + ptr_to_u64(info_linear->data); 4993 bpf_prog_info_set_offset_u64(&info_linear->info, 4994 desc->array_offset, addr); 4995 } 4996 } 4997 4998 int libbpf_num_possible_cpus(void) 4999 { 5000 static const char *fcpu = "/sys/devices/system/cpu/possible"; 5001 int len = 0, n = 0, il = 0, ir = 0; 5002 unsigned int start = 0, end = 0; 5003 static int cpus; 5004 char buf[128]; 5005 int error = 0; 5006 int fd = -1; 5007 5008 if (cpus > 0) 5009 return cpus; 5010 5011 fd = open(fcpu, O_RDONLY); 5012 if (fd < 0) { 5013 error = errno; 5014 pr_warning("Failed to open file %s: %s\n", 5015 fcpu, strerror(error)); 5016 return -error; 5017 } 5018 len = read(fd, buf, sizeof(buf)); 5019 close(fd); 5020 if (len <= 0) { 5021 error = len ? errno : EINVAL; 5022 pr_warning("Failed to read # of possible cpus from %s: %s\n", 5023 fcpu, strerror(error)); 5024 return -error; 5025 } 5026 if (len == sizeof(buf)) { 5027 pr_warning("File %s size overflow\n", fcpu); 5028 return -EOVERFLOW; 5029 } 5030 buf[len] = '\0'; 5031 5032 for (ir = 0, cpus = 0; ir <= len; ir++) { 5033 /* Each sub string separated by ',' has format \d+-\d+ or \d+ */ 5034 if (buf[ir] == ',' || buf[ir] == '\0') { 5035 buf[ir] = '\0'; 5036 n = sscanf(&buf[il], "%u-%u", &start, &end); 5037 if (n <= 0) { 5038 pr_warning("Failed to get # CPUs from %s\n", 5039 &buf[il]); 5040 return -EINVAL; 5041 } else if (n == 1) { 5042 end = start; 5043 } 5044 cpus += end - start + 1; 5045 il = ir + 1; 5046 } 5047 } 5048 if (cpus <= 0) { 5049 pr_warning("Invalid #CPUs %d from %s\n", cpus, fcpu); 5050 return -EINVAL; 5051 } 5052 return cpus; 5053 } 5054