1 // SPDX-License-Identifier: LGPL-2.1 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 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU Lesser General Public 13 * License as published by the Free Software Foundation; 14 * version 2.1 of the License (not later!) 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU Lesser General Public License for more details. 20 * 21 * You should have received a copy of the GNU Lesser General Public 22 * License along with this program; if not, see <http://www.gnu.org/licenses> 23 */ 24 25 #include <stdlib.h> 26 #include <stdio.h> 27 #include <stdarg.h> 28 #include <libgen.h> 29 #include <inttypes.h> 30 #include <string.h> 31 #include <unistd.h> 32 #include <fcntl.h> 33 #include <errno.h> 34 #include <perf-sys.h> 35 #include <asm/unistd.h> 36 #include <linux/err.h> 37 #include <linux/kernel.h> 38 #include <linux/bpf.h> 39 #include <linux/list.h> 40 #include <linux/limits.h> 41 #include <sys/stat.h> 42 #include <sys/types.h> 43 #include <sys/vfs.h> 44 #include <libelf.h> 45 #include <gelf.h> 46 47 #include "libbpf.h" 48 #include "bpf.h" 49 #include "btf.h" 50 51 #ifndef EM_BPF 52 #define EM_BPF 247 53 #endif 54 55 #ifndef BPF_FS_MAGIC 56 #define BPF_FS_MAGIC 0xcafe4a11 57 #endif 58 59 #define __printf(a, b) __attribute__((format(printf, a, b))) 60 61 __printf(1, 2) 62 static int __base_pr(const char *format, ...) 63 { 64 va_list args; 65 int err; 66 67 va_start(args, format); 68 err = vfprintf(stderr, format, args); 69 va_end(args); 70 return err; 71 } 72 73 static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr; 74 static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr; 75 static __printf(1, 2) libbpf_print_fn_t __pr_debug; 76 77 #define __pr(func, fmt, ...) \ 78 do { \ 79 if ((func)) \ 80 (func)("libbpf: " fmt, ##__VA_ARGS__); \ 81 } while (0) 82 83 #define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__) 84 #define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__) 85 #define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__) 86 87 void libbpf_set_print(libbpf_print_fn_t warn, 88 libbpf_print_fn_t info, 89 libbpf_print_fn_t debug) 90 { 91 __pr_warning = warn; 92 __pr_info = info; 93 __pr_debug = debug; 94 } 95 96 #define STRERR_BUFSIZE 128 97 98 #define ERRNO_OFFSET(e) ((e) - __LIBBPF_ERRNO__START) 99 #define ERRCODE_OFFSET(c) ERRNO_OFFSET(LIBBPF_ERRNO__##c) 100 #define NR_ERRNO (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START) 101 102 static const char *libbpf_strerror_table[NR_ERRNO] = { 103 [ERRCODE_OFFSET(LIBELF)] = "Something wrong in libelf", 104 [ERRCODE_OFFSET(FORMAT)] = "BPF object format invalid", 105 [ERRCODE_OFFSET(KVERSION)] = "'version' section incorrect or lost", 106 [ERRCODE_OFFSET(ENDIAN)] = "Endian mismatch", 107 [ERRCODE_OFFSET(INTERNAL)] = "Internal error in libbpf", 108 [ERRCODE_OFFSET(RELOC)] = "Relocation failed", 109 [ERRCODE_OFFSET(VERIFY)] = "Kernel verifier blocks program loading", 110 [ERRCODE_OFFSET(PROG2BIG)] = "Program too big", 111 [ERRCODE_OFFSET(KVER)] = "Incorrect kernel version", 112 [ERRCODE_OFFSET(PROGTYPE)] = "Kernel doesn't support this program type", 113 [ERRCODE_OFFSET(WRNGPID)] = "Wrong pid in netlink message", 114 [ERRCODE_OFFSET(INVSEQ)] = "Invalid netlink sequence", 115 }; 116 117 int libbpf_strerror(int err, char *buf, size_t size) 118 { 119 if (!buf || !size) 120 return -1; 121 122 err = err > 0 ? err : -err; 123 124 if (err < __LIBBPF_ERRNO__START) { 125 int ret; 126 127 ret = strerror_r(err, buf, size); 128 buf[size - 1] = '\0'; 129 return ret; 130 } 131 132 if (err < __LIBBPF_ERRNO__END) { 133 const char *msg; 134 135 msg = libbpf_strerror_table[ERRNO_OFFSET(err)]; 136 snprintf(buf, size, "%s", msg); 137 buf[size - 1] = '\0'; 138 return 0; 139 } 140 141 snprintf(buf, size, "Unknown libbpf error %d", err); 142 buf[size - 1] = '\0'; 143 return -1; 144 } 145 146 #define CHECK_ERR(action, err, out) do { \ 147 err = action; \ 148 if (err) \ 149 goto out; \ 150 } while(0) 151 152 153 /* Copied from tools/perf/util/util.h */ 154 #ifndef zfree 155 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; }) 156 #endif 157 158 #ifndef zclose 159 # define zclose(fd) ({ \ 160 int ___err = 0; \ 161 if ((fd) >= 0) \ 162 ___err = close((fd)); \ 163 fd = -1; \ 164 ___err; }) 165 #endif 166 167 #ifdef HAVE_LIBELF_MMAP_SUPPORT 168 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP 169 #else 170 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ 171 #endif 172 173 /* 174 * bpf_prog should be a better name but it has been used in 175 * linux/filter.h. 176 */ 177 struct bpf_program { 178 /* Index in elf obj file, for relocation use. */ 179 int idx; 180 char *name; 181 int prog_ifindex; 182 char *section_name; 183 struct bpf_insn *insns; 184 size_t insns_cnt, main_prog_cnt; 185 enum bpf_prog_type type; 186 187 struct reloc_desc { 188 enum { 189 RELO_LD64, 190 RELO_CALL, 191 } type; 192 int insn_idx; 193 union { 194 int map_idx; 195 int text_off; 196 }; 197 } *reloc_desc; 198 int nr_reloc; 199 200 struct { 201 int nr; 202 int *fds; 203 } instances; 204 bpf_program_prep_t preprocessor; 205 206 struct bpf_object *obj; 207 void *priv; 208 bpf_program_clear_priv_t clear_priv; 209 210 enum bpf_attach_type expected_attach_type; 211 }; 212 213 struct bpf_map { 214 int fd; 215 char *name; 216 size_t offset; 217 int map_ifindex; 218 struct bpf_map_def def; 219 uint32_t btf_key_type_id; 220 uint32_t btf_value_type_id; 221 void *priv; 222 bpf_map_clear_priv_t clear_priv; 223 }; 224 225 static LIST_HEAD(bpf_objects_list); 226 227 struct bpf_object { 228 char license[64]; 229 u32 kern_version; 230 231 struct bpf_program *programs; 232 size_t nr_programs; 233 struct bpf_map *maps; 234 size_t nr_maps; 235 236 bool loaded; 237 bool has_pseudo_calls; 238 239 /* 240 * Information when doing elf related work. Only valid if fd 241 * is valid. 242 */ 243 struct { 244 int fd; 245 void *obj_buf; 246 size_t obj_buf_sz; 247 Elf *elf; 248 GElf_Ehdr ehdr; 249 Elf_Data *symbols; 250 size_t strtabidx; 251 struct { 252 GElf_Shdr shdr; 253 Elf_Data *data; 254 } *reloc; 255 int nr_reloc; 256 int maps_shndx; 257 int text_shndx; 258 } efile; 259 /* 260 * All loaded bpf_object is linked in a list, which is 261 * hidden to caller. bpf_objects__<func> handlers deal with 262 * all objects. 263 */ 264 struct list_head list; 265 266 struct btf *btf; 267 268 void *priv; 269 bpf_object_clear_priv_t clear_priv; 270 271 char path[]; 272 }; 273 #define obj_elf_valid(o) ((o)->efile.elf) 274 275 static void bpf_program__unload(struct bpf_program *prog) 276 { 277 int i; 278 279 if (!prog) 280 return; 281 282 /* 283 * If the object is opened but the program was never loaded, 284 * it is possible that prog->instances.nr == -1. 285 */ 286 if (prog->instances.nr > 0) { 287 for (i = 0; i < prog->instances.nr; i++) 288 zclose(prog->instances.fds[i]); 289 } else if (prog->instances.nr != -1) { 290 pr_warning("Internal error: instances.nr is %d\n", 291 prog->instances.nr); 292 } 293 294 prog->instances.nr = -1; 295 zfree(&prog->instances.fds); 296 } 297 298 static void bpf_program__exit(struct bpf_program *prog) 299 { 300 if (!prog) 301 return; 302 303 if (prog->clear_priv) 304 prog->clear_priv(prog, prog->priv); 305 306 prog->priv = NULL; 307 prog->clear_priv = NULL; 308 309 bpf_program__unload(prog); 310 zfree(&prog->name); 311 zfree(&prog->section_name); 312 zfree(&prog->insns); 313 zfree(&prog->reloc_desc); 314 315 prog->nr_reloc = 0; 316 prog->insns_cnt = 0; 317 prog->idx = -1; 318 } 319 320 static int 321 bpf_program__init(void *data, size_t size, char *section_name, int idx, 322 struct bpf_program *prog) 323 { 324 if (size < sizeof(struct bpf_insn)) { 325 pr_warning("corrupted section '%s'\n", section_name); 326 return -EINVAL; 327 } 328 329 bzero(prog, sizeof(*prog)); 330 331 prog->section_name = strdup(section_name); 332 if (!prog->section_name) { 333 pr_warning("failed to alloc name for prog under section(%d) %s\n", 334 idx, section_name); 335 goto errout; 336 } 337 338 prog->insns = malloc(size); 339 if (!prog->insns) { 340 pr_warning("failed to alloc insns for prog under section %s\n", 341 section_name); 342 goto errout; 343 } 344 prog->insns_cnt = size / sizeof(struct bpf_insn); 345 memcpy(prog->insns, data, 346 prog->insns_cnt * sizeof(struct bpf_insn)); 347 prog->idx = idx; 348 prog->instances.fds = NULL; 349 prog->instances.nr = -1; 350 prog->type = BPF_PROG_TYPE_KPROBE; 351 352 return 0; 353 errout: 354 bpf_program__exit(prog); 355 return -ENOMEM; 356 } 357 358 static int 359 bpf_object__add_program(struct bpf_object *obj, void *data, size_t size, 360 char *section_name, int idx) 361 { 362 struct bpf_program prog, *progs; 363 int nr_progs, err; 364 365 err = bpf_program__init(data, size, section_name, idx, &prog); 366 if (err) 367 return err; 368 369 progs = obj->programs; 370 nr_progs = obj->nr_programs; 371 372 progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1)); 373 if (!progs) { 374 /* 375 * In this case the original obj->programs 376 * is still valid, so don't need special treat for 377 * bpf_close_object(). 378 */ 379 pr_warning("failed to alloc a new program under section '%s'\n", 380 section_name); 381 bpf_program__exit(&prog); 382 return -ENOMEM; 383 } 384 385 pr_debug("found program %s\n", prog.section_name); 386 obj->programs = progs; 387 obj->nr_programs = nr_progs + 1; 388 prog.obj = obj; 389 progs[nr_progs] = prog; 390 return 0; 391 } 392 393 static int 394 bpf_object__init_prog_names(struct bpf_object *obj) 395 { 396 Elf_Data *symbols = obj->efile.symbols; 397 struct bpf_program *prog; 398 size_t pi, si; 399 400 for (pi = 0; pi < obj->nr_programs; pi++) { 401 const char *name = NULL; 402 403 prog = &obj->programs[pi]; 404 405 for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name; 406 si++) { 407 GElf_Sym sym; 408 409 if (!gelf_getsym(symbols, si, &sym)) 410 continue; 411 if (sym.st_shndx != prog->idx) 412 continue; 413 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL) 414 continue; 415 416 name = elf_strptr(obj->efile.elf, 417 obj->efile.strtabidx, 418 sym.st_name); 419 if (!name) { 420 pr_warning("failed to get sym name string for prog %s\n", 421 prog->section_name); 422 return -LIBBPF_ERRNO__LIBELF; 423 } 424 } 425 426 if (!name && prog->idx == obj->efile.text_shndx) 427 name = ".text"; 428 429 if (!name) { 430 pr_warning("failed to find sym for prog %s\n", 431 prog->section_name); 432 return -EINVAL; 433 } 434 435 prog->name = strdup(name); 436 if (!prog->name) { 437 pr_warning("failed to allocate memory for prog sym %s\n", 438 name); 439 return -ENOMEM; 440 } 441 } 442 443 return 0; 444 } 445 446 static struct bpf_object *bpf_object__new(const char *path, 447 void *obj_buf, 448 size_t obj_buf_sz) 449 { 450 struct bpf_object *obj; 451 452 obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1); 453 if (!obj) { 454 pr_warning("alloc memory failed for %s\n", path); 455 return ERR_PTR(-ENOMEM); 456 } 457 458 strcpy(obj->path, path); 459 obj->efile.fd = -1; 460 461 /* 462 * Caller of this function should also calls 463 * bpf_object__elf_finish() after data collection to return 464 * obj_buf to user. If not, we should duplicate the buffer to 465 * avoid user freeing them before elf finish. 466 */ 467 obj->efile.obj_buf = obj_buf; 468 obj->efile.obj_buf_sz = obj_buf_sz; 469 obj->efile.maps_shndx = -1; 470 471 obj->loaded = false; 472 473 INIT_LIST_HEAD(&obj->list); 474 list_add(&obj->list, &bpf_objects_list); 475 return obj; 476 } 477 478 static void bpf_object__elf_finish(struct bpf_object *obj) 479 { 480 if (!obj_elf_valid(obj)) 481 return; 482 483 if (obj->efile.elf) { 484 elf_end(obj->efile.elf); 485 obj->efile.elf = NULL; 486 } 487 obj->efile.symbols = NULL; 488 489 zfree(&obj->efile.reloc); 490 obj->efile.nr_reloc = 0; 491 zclose(obj->efile.fd); 492 obj->efile.obj_buf = NULL; 493 obj->efile.obj_buf_sz = 0; 494 } 495 496 static int bpf_object__elf_init(struct bpf_object *obj) 497 { 498 int err = 0; 499 GElf_Ehdr *ep; 500 501 if (obj_elf_valid(obj)) { 502 pr_warning("elf init: internal error\n"); 503 return -LIBBPF_ERRNO__LIBELF; 504 } 505 506 if (obj->efile.obj_buf_sz > 0) { 507 /* 508 * obj_buf should have been validated by 509 * bpf_object__open_buffer(). 510 */ 511 obj->efile.elf = elf_memory(obj->efile.obj_buf, 512 obj->efile.obj_buf_sz); 513 } else { 514 obj->efile.fd = open(obj->path, O_RDONLY); 515 if (obj->efile.fd < 0) { 516 pr_warning("failed to open %s: %s\n", obj->path, 517 strerror(errno)); 518 return -errno; 519 } 520 521 obj->efile.elf = elf_begin(obj->efile.fd, 522 LIBBPF_ELF_C_READ_MMAP, 523 NULL); 524 } 525 526 if (!obj->efile.elf) { 527 pr_warning("failed to open %s as ELF file\n", 528 obj->path); 529 err = -LIBBPF_ERRNO__LIBELF; 530 goto errout; 531 } 532 533 if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) { 534 pr_warning("failed to get EHDR from %s\n", 535 obj->path); 536 err = -LIBBPF_ERRNO__FORMAT; 537 goto errout; 538 } 539 ep = &obj->efile.ehdr; 540 541 /* Old LLVM set e_machine to EM_NONE */ 542 if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != EM_BPF))) { 543 pr_warning("%s is not an eBPF object file\n", 544 obj->path); 545 err = -LIBBPF_ERRNO__FORMAT; 546 goto errout; 547 } 548 549 return 0; 550 errout: 551 bpf_object__elf_finish(obj); 552 return err; 553 } 554 555 static int 556 bpf_object__check_endianness(struct bpf_object *obj) 557 { 558 static unsigned int const endian = 1; 559 560 switch (obj->efile.ehdr.e_ident[EI_DATA]) { 561 case ELFDATA2LSB: 562 /* We are big endian, BPF obj is little endian. */ 563 if (*(unsigned char const *)&endian != 1) 564 goto mismatch; 565 break; 566 567 case ELFDATA2MSB: 568 /* We are little endian, BPF obj is big endian. */ 569 if (*(unsigned char const *)&endian != 0) 570 goto mismatch; 571 break; 572 default: 573 return -LIBBPF_ERRNO__ENDIAN; 574 } 575 576 return 0; 577 578 mismatch: 579 pr_warning("Error: endianness mismatch.\n"); 580 return -LIBBPF_ERRNO__ENDIAN; 581 } 582 583 static int 584 bpf_object__init_license(struct bpf_object *obj, 585 void *data, size_t size) 586 { 587 memcpy(obj->license, data, 588 min(size, sizeof(obj->license) - 1)); 589 pr_debug("license of %s is %s\n", obj->path, obj->license); 590 return 0; 591 } 592 593 static int 594 bpf_object__init_kversion(struct bpf_object *obj, 595 void *data, size_t size) 596 { 597 u32 kver; 598 599 if (size != sizeof(kver)) { 600 pr_warning("invalid kver section in %s\n", obj->path); 601 return -LIBBPF_ERRNO__FORMAT; 602 } 603 memcpy(&kver, data, sizeof(kver)); 604 obj->kern_version = kver; 605 pr_debug("kernel version of %s is %x\n", obj->path, 606 obj->kern_version); 607 return 0; 608 } 609 610 static int compare_bpf_map(const void *_a, const void *_b) 611 { 612 const struct bpf_map *a = _a; 613 const struct bpf_map *b = _b; 614 615 return a->offset - b->offset; 616 } 617 618 static int 619 bpf_object__init_maps(struct bpf_object *obj) 620 { 621 int i, map_idx, map_def_sz, nr_maps = 0; 622 Elf_Scn *scn; 623 Elf_Data *data; 624 Elf_Data *symbols = obj->efile.symbols; 625 626 if (obj->efile.maps_shndx < 0) 627 return -EINVAL; 628 if (!symbols) 629 return -EINVAL; 630 631 scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); 632 if (scn) 633 data = elf_getdata(scn, NULL); 634 if (!scn || !data) { 635 pr_warning("failed to get Elf_Data from map section %d\n", 636 obj->efile.maps_shndx); 637 return -EINVAL; 638 } 639 640 /* 641 * Count number of maps. Each map has a name. 642 * Array of maps is not supported: only the first element is 643 * considered. 644 * 645 * TODO: Detect array of map and report error. 646 */ 647 for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) { 648 GElf_Sym sym; 649 650 if (!gelf_getsym(symbols, i, &sym)) 651 continue; 652 if (sym.st_shndx != obj->efile.maps_shndx) 653 continue; 654 nr_maps++; 655 } 656 657 /* Alloc obj->maps and fill nr_maps. */ 658 pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path, 659 nr_maps, data->d_size); 660 661 if (!nr_maps) 662 return 0; 663 664 /* Assume equally sized map definitions */ 665 map_def_sz = data->d_size / nr_maps; 666 if (!data->d_size || (data->d_size % nr_maps) != 0) { 667 pr_warning("unable to determine map definition size " 668 "section %s, %d maps in %zd bytes\n", 669 obj->path, nr_maps, data->d_size); 670 return -EINVAL; 671 } 672 673 obj->maps = calloc(nr_maps, sizeof(obj->maps[0])); 674 if (!obj->maps) { 675 pr_warning("alloc maps for object failed\n"); 676 return -ENOMEM; 677 } 678 obj->nr_maps = nr_maps; 679 680 /* 681 * fill all fd with -1 so won't close incorrect 682 * fd (fd=0 is stdin) when failure (zclose won't close 683 * negative fd)). 684 */ 685 for (i = 0; i < nr_maps; i++) 686 obj->maps[i].fd = -1; 687 688 /* 689 * Fill obj->maps using data in "maps" section. 690 */ 691 for (i = 0, map_idx = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) { 692 GElf_Sym sym; 693 const char *map_name; 694 struct bpf_map_def *def; 695 696 if (!gelf_getsym(symbols, i, &sym)) 697 continue; 698 if (sym.st_shndx != obj->efile.maps_shndx) 699 continue; 700 701 map_name = elf_strptr(obj->efile.elf, 702 obj->efile.strtabidx, 703 sym.st_name); 704 obj->maps[map_idx].offset = sym.st_value; 705 if (sym.st_value + map_def_sz > data->d_size) { 706 pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", 707 obj->path, map_name); 708 return -EINVAL; 709 } 710 711 obj->maps[map_idx].name = strdup(map_name); 712 if (!obj->maps[map_idx].name) { 713 pr_warning("failed to alloc map name\n"); 714 return -ENOMEM; 715 } 716 pr_debug("map %d is \"%s\"\n", map_idx, 717 obj->maps[map_idx].name); 718 def = (struct bpf_map_def *)(data->d_buf + sym.st_value); 719 /* 720 * If the definition of the map in the object file fits in 721 * bpf_map_def, copy it. Any extra fields in our version 722 * of bpf_map_def will default to zero as a result of the 723 * calloc above. 724 */ 725 if (map_def_sz <= sizeof(struct bpf_map_def)) { 726 memcpy(&obj->maps[map_idx].def, def, map_def_sz); 727 } else { 728 /* 729 * Here the map structure being read is bigger than what 730 * we expect, truncate if the excess bits are all zero. 731 * If they are not zero, reject this map as 732 * incompatible. 733 */ 734 char *b; 735 for (b = ((char *)def) + sizeof(struct bpf_map_def); 736 b < ((char *)def) + map_def_sz; b++) { 737 if (*b != 0) { 738 pr_warning("maps section in %s: \"%s\" " 739 "has unrecognized, non-zero " 740 "options\n", 741 obj->path, map_name); 742 return -EINVAL; 743 } 744 } 745 memcpy(&obj->maps[map_idx].def, def, 746 sizeof(struct bpf_map_def)); 747 } 748 map_idx++; 749 } 750 751 qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map); 752 return 0; 753 } 754 755 static bool section_have_execinstr(struct bpf_object *obj, int idx) 756 { 757 Elf_Scn *scn; 758 GElf_Shdr sh; 759 760 scn = elf_getscn(obj->efile.elf, idx); 761 if (!scn) 762 return false; 763 764 if (gelf_getshdr(scn, &sh) != &sh) 765 return false; 766 767 if (sh.sh_flags & SHF_EXECINSTR) 768 return true; 769 770 return false; 771 } 772 773 static int bpf_object__elf_collect(struct bpf_object *obj) 774 { 775 Elf *elf = obj->efile.elf; 776 GElf_Ehdr *ep = &obj->efile.ehdr; 777 Elf_Scn *scn = NULL; 778 int idx = 0, err = 0; 779 780 /* Elf is corrupted/truncated, avoid calling elf_strptr. */ 781 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) { 782 pr_warning("failed to get e_shstrndx from %s\n", 783 obj->path); 784 return -LIBBPF_ERRNO__FORMAT; 785 } 786 787 while ((scn = elf_nextscn(elf, scn)) != NULL) { 788 char *name; 789 GElf_Shdr sh; 790 Elf_Data *data; 791 792 idx++; 793 if (gelf_getshdr(scn, &sh) != &sh) { 794 pr_warning("failed to get section(%d) header from %s\n", 795 idx, obj->path); 796 err = -LIBBPF_ERRNO__FORMAT; 797 goto out; 798 } 799 800 name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); 801 if (!name) { 802 pr_warning("failed to get section(%d) name from %s\n", 803 idx, obj->path); 804 err = -LIBBPF_ERRNO__FORMAT; 805 goto out; 806 } 807 808 data = elf_getdata(scn, 0); 809 if (!data) { 810 pr_warning("failed to get section(%d) data from %s(%s)\n", 811 idx, name, obj->path); 812 err = -LIBBPF_ERRNO__FORMAT; 813 goto out; 814 } 815 pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n", 816 idx, name, (unsigned long)data->d_size, 817 (int)sh.sh_link, (unsigned long)sh.sh_flags, 818 (int)sh.sh_type); 819 820 if (strcmp(name, "license") == 0) 821 err = bpf_object__init_license(obj, 822 data->d_buf, 823 data->d_size); 824 else if (strcmp(name, "version") == 0) 825 err = bpf_object__init_kversion(obj, 826 data->d_buf, 827 data->d_size); 828 else if (strcmp(name, "maps") == 0) 829 obj->efile.maps_shndx = idx; 830 else if (strcmp(name, BTF_ELF_SEC) == 0) { 831 obj->btf = btf__new(data->d_buf, data->d_size, 832 __pr_debug); 833 if (IS_ERR(obj->btf)) { 834 pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n", 835 BTF_ELF_SEC, PTR_ERR(obj->btf)); 836 obj->btf = NULL; 837 } 838 } else if (sh.sh_type == SHT_SYMTAB) { 839 if (obj->efile.symbols) { 840 pr_warning("bpf: multiple SYMTAB in %s\n", 841 obj->path); 842 err = -LIBBPF_ERRNO__FORMAT; 843 } else { 844 obj->efile.symbols = data; 845 obj->efile.strtabidx = sh.sh_link; 846 } 847 } else if ((sh.sh_type == SHT_PROGBITS) && 848 (sh.sh_flags & SHF_EXECINSTR) && 849 (data->d_size > 0)) { 850 if (strcmp(name, ".text") == 0) 851 obj->efile.text_shndx = idx; 852 err = bpf_object__add_program(obj, data->d_buf, 853 data->d_size, name, idx); 854 if (err) { 855 char errmsg[STRERR_BUFSIZE]; 856 857 strerror_r(-err, errmsg, sizeof(errmsg)); 858 pr_warning("failed to alloc program %s (%s): %s", 859 name, obj->path, errmsg); 860 } 861 } else if (sh.sh_type == SHT_REL) { 862 void *reloc = obj->efile.reloc; 863 int nr_reloc = obj->efile.nr_reloc + 1; 864 int sec = sh.sh_info; /* points to other section */ 865 866 /* Only do relo for section with exec instructions */ 867 if (!section_have_execinstr(obj, sec)) { 868 pr_debug("skip relo %s(%d) for section(%d)\n", 869 name, idx, sec); 870 continue; 871 } 872 873 reloc = realloc(reloc, 874 sizeof(*obj->efile.reloc) * nr_reloc); 875 if (!reloc) { 876 pr_warning("realloc failed\n"); 877 err = -ENOMEM; 878 } else { 879 int n = nr_reloc - 1; 880 881 obj->efile.reloc = reloc; 882 obj->efile.nr_reloc = nr_reloc; 883 884 obj->efile.reloc[n].shdr = sh; 885 obj->efile.reloc[n].data = data; 886 } 887 } else { 888 pr_debug("skip section(%d) %s\n", idx, name); 889 } 890 if (err) 891 goto out; 892 } 893 894 if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) { 895 pr_warning("Corrupted ELF file: index of strtab invalid\n"); 896 return LIBBPF_ERRNO__FORMAT; 897 } 898 if (obj->efile.maps_shndx >= 0) { 899 err = bpf_object__init_maps(obj); 900 if (err) 901 goto out; 902 } 903 err = bpf_object__init_prog_names(obj); 904 out: 905 return err; 906 } 907 908 static struct bpf_program * 909 bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx) 910 { 911 struct bpf_program *prog; 912 size_t i; 913 914 for (i = 0; i < obj->nr_programs; i++) { 915 prog = &obj->programs[i]; 916 if (prog->idx == idx) 917 return prog; 918 } 919 return NULL; 920 } 921 922 static int 923 bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, 924 Elf_Data *data, struct bpf_object *obj) 925 { 926 Elf_Data *symbols = obj->efile.symbols; 927 int text_shndx = obj->efile.text_shndx; 928 int maps_shndx = obj->efile.maps_shndx; 929 struct bpf_map *maps = obj->maps; 930 size_t nr_maps = obj->nr_maps; 931 int i, nrels; 932 933 pr_debug("collecting relocating info for: '%s'\n", 934 prog->section_name); 935 nrels = shdr->sh_size / shdr->sh_entsize; 936 937 prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels); 938 if (!prog->reloc_desc) { 939 pr_warning("failed to alloc memory in relocation\n"); 940 return -ENOMEM; 941 } 942 prog->nr_reloc = nrels; 943 944 for (i = 0; i < nrels; i++) { 945 GElf_Sym sym; 946 GElf_Rel rel; 947 unsigned int insn_idx; 948 struct bpf_insn *insns = prog->insns; 949 size_t map_idx; 950 951 if (!gelf_getrel(data, i, &rel)) { 952 pr_warning("relocation: failed to get %d reloc\n", i); 953 return -LIBBPF_ERRNO__FORMAT; 954 } 955 956 if (!gelf_getsym(symbols, 957 GELF_R_SYM(rel.r_info), 958 &sym)) { 959 pr_warning("relocation: symbol %"PRIx64" not found\n", 960 GELF_R_SYM(rel.r_info)); 961 return -LIBBPF_ERRNO__FORMAT; 962 } 963 pr_debug("relo for %lld value %lld name %d\n", 964 (long long) (rel.r_info >> 32), 965 (long long) sym.st_value, sym.st_name); 966 967 if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) { 968 pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n", 969 prog->section_name, sym.st_shndx); 970 return -LIBBPF_ERRNO__RELOC; 971 } 972 973 insn_idx = rel.r_offset / sizeof(struct bpf_insn); 974 pr_debug("relocation: insn_idx=%u\n", insn_idx); 975 976 if (insns[insn_idx].code == (BPF_JMP | BPF_CALL)) { 977 if (insns[insn_idx].src_reg != BPF_PSEUDO_CALL) { 978 pr_warning("incorrect bpf_call opcode\n"); 979 return -LIBBPF_ERRNO__RELOC; 980 } 981 prog->reloc_desc[i].type = RELO_CALL; 982 prog->reloc_desc[i].insn_idx = insn_idx; 983 prog->reloc_desc[i].text_off = sym.st_value; 984 obj->has_pseudo_calls = true; 985 continue; 986 } 987 988 if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) { 989 pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n", 990 insn_idx, insns[insn_idx].code); 991 return -LIBBPF_ERRNO__RELOC; 992 } 993 994 /* TODO: 'maps' is sorted. We can use bsearch to make it faster. */ 995 for (map_idx = 0; map_idx < nr_maps; map_idx++) { 996 if (maps[map_idx].offset == sym.st_value) { 997 pr_debug("relocation: find map %zd (%s) for insn %u\n", 998 map_idx, maps[map_idx].name, insn_idx); 999 break; 1000 } 1001 } 1002 1003 if (map_idx >= nr_maps) { 1004 pr_warning("bpf relocation: map_idx %d large than %d\n", 1005 (int)map_idx, (int)nr_maps - 1); 1006 return -LIBBPF_ERRNO__RELOC; 1007 } 1008 1009 prog->reloc_desc[i].type = RELO_LD64; 1010 prog->reloc_desc[i].insn_idx = insn_idx; 1011 prog->reloc_desc[i].map_idx = map_idx; 1012 } 1013 return 0; 1014 } 1015 1016 static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf) 1017 { 1018 struct bpf_map_def *def = &map->def; 1019 const size_t max_name = 256; 1020 int64_t key_size, value_size; 1021 int32_t key_id, value_id; 1022 char name[max_name]; 1023 1024 /* Find key type by name from BTF */ 1025 if (snprintf(name, max_name, "%s_key", map->name) == max_name) { 1026 pr_warning("map:%s length of BTF key_type:%s_key is too long\n", 1027 map->name, map->name); 1028 return -EINVAL; 1029 } 1030 1031 key_id = btf__find_by_name(btf, name); 1032 if (key_id < 0) { 1033 pr_debug("map:%s key_type:%s cannot be found in BTF\n", 1034 map->name, name); 1035 return key_id; 1036 } 1037 1038 key_size = btf__resolve_size(btf, key_id); 1039 if (key_size < 0) { 1040 pr_warning("map:%s key_type:%s cannot get the BTF type_size\n", 1041 map->name, name); 1042 return key_size; 1043 } 1044 1045 if (def->key_size != key_size) { 1046 pr_warning("map:%s key_type:%s has BTF type_size:%u != key_size:%u\n", 1047 map->name, name, (unsigned int)key_size, def->key_size); 1048 return -EINVAL; 1049 } 1050 1051 /* Find value type from BTF */ 1052 if (snprintf(name, max_name, "%s_value", map->name) == max_name) { 1053 pr_warning("map:%s length of BTF value_type:%s_value is too long\n", 1054 map->name, map->name); 1055 return -EINVAL; 1056 } 1057 1058 value_id = btf__find_by_name(btf, name); 1059 if (value_id < 0) { 1060 pr_debug("map:%s value_type:%s cannot be found in BTF\n", 1061 map->name, name); 1062 return value_id; 1063 } 1064 1065 value_size = btf__resolve_size(btf, value_id); 1066 if (value_size < 0) { 1067 pr_warning("map:%s value_type:%s cannot get the BTF type_size\n", 1068 map->name, name); 1069 return value_size; 1070 } 1071 1072 if (def->value_size != value_size) { 1073 pr_warning("map:%s value_type:%s has BTF type_size:%u != value_size:%u\n", 1074 map->name, name, (unsigned int)value_size, def->value_size); 1075 return -EINVAL; 1076 } 1077 1078 map->btf_key_type_id = key_id; 1079 map->btf_value_type_id = value_id; 1080 1081 return 0; 1082 } 1083 1084 static int 1085 bpf_object__create_maps(struct bpf_object *obj) 1086 { 1087 struct bpf_create_map_attr create_attr = {}; 1088 unsigned int i; 1089 int err; 1090 1091 for (i = 0; i < obj->nr_maps; i++) { 1092 struct bpf_map *map = &obj->maps[i]; 1093 struct bpf_map_def *def = &map->def; 1094 int *pfd = &map->fd; 1095 1096 create_attr.name = map->name; 1097 create_attr.map_ifindex = map->map_ifindex; 1098 create_attr.map_type = def->type; 1099 create_attr.map_flags = def->map_flags; 1100 create_attr.key_size = def->key_size; 1101 create_attr.value_size = def->value_size; 1102 create_attr.max_entries = def->max_entries; 1103 create_attr.btf_fd = 0; 1104 create_attr.btf_key_type_id = 0; 1105 create_attr.btf_value_type_id = 0; 1106 1107 if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) { 1108 create_attr.btf_fd = btf__fd(obj->btf); 1109 create_attr.btf_key_type_id = map->btf_key_type_id; 1110 create_attr.btf_value_type_id = map->btf_value_type_id; 1111 } 1112 1113 *pfd = bpf_create_map_xattr(&create_attr); 1114 if (*pfd < 0 && create_attr.btf_key_type_id) { 1115 pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", 1116 map->name, strerror(errno), errno); 1117 create_attr.btf_fd = 0; 1118 create_attr.btf_key_type_id = 0; 1119 create_attr.btf_value_type_id = 0; 1120 map->btf_key_type_id = 0; 1121 map->btf_value_type_id = 0; 1122 *pfd = bpf_create_map_xattr(&create_attr); 1123 } 1124 1125 if (*pfd < 0) { 1126 size_t j; 1127 1128 err = *pfd; 1129 pr_warning("failed to create map (name: '%s'): %s\n", 1130 map->name, 1131 strerror(errno)); 1132 for (j = 0; j < i; j++) 1133 zclose(obj->maps[j].fd); 1134 return err; 1135 } 1136 pr_debug("create map %s: fd=%d\n", map->name, *pfd); 1137 } 1138 1139 return 0; 1140 } 1141 1142 static int 1143 bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj, 1144 struct reloc_desc *relo) 1145 { 1146 struct bpf_insn *insn, *new_insn; 1147 struct bpf_program *text; 1148 size_t new_cnt; 1149 1150 if (relo->type != RELO_CALL) 1151 return -LIBBPF_ERRNO__RELOC; 1152 1153 if (prog->idx == obj->efile.text_shndx) { 1154 pr_warning("relo in .text insn %d into off %d\n", 1155 relo->insn_idx, relo->text_off); 1156 return -LIBBPF_ERRNO__RELOC; 1157 } 1158 1159 if (prog->main_prog_cnt == 0) { 1160 text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx); 1161 if (!text) { 1162 pr_warning("no .text section found yet relo into text exist\n"); 1163 return -LIBBPF_ERRNO__RELOC; 1164 } 1165 new_cnt = prog->insns_cnt + text->insns_cnt; 1166 new_insn = realloc(prog->insns, new_cnt * sizeof(*insn)); 1167 if (!new_insn) { 1168 pr_warning("oom in prog realloc\n"); 1169 return -ENOMEM; 1170 } 1171 memcpy(new_insn + prog->insns_cnt, text->insns, 1172 text->insns_cnt * sizeof(*insn)); 1173 prog->insns = new_insn; 1174 prog->main_prog_cnt = prog->insns_cnt; 1175 prog->insns_cnt = new_cnt; 1176 pr_debug("added %zd insn from %s to prog %s\n", 1177 text->insns_cnt, text->section_name, 1178 prog->section_name); 1179 } 1180 insn = &prog->insns[relo->insn_idx]; 1181 insn->imm += prog->main_prog_cnt - relo->insn_idx; 1182 return 0; 1183 } 1184 1185 static int 1186 bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj) 1187 { 1188 int i, err; 1189 1190 if (!prog || !prog->reloc_desc) 1191 return 0; 1192 1193 for (i = 0; i < prog->nr_reloc; i++) { 1194 if (prog->reloc_desc[i].type == RELO_LD64) { 1195 struct bpf_insn *insns = prog->insns; 1196 int insn_idx, map_idx; 1197 1198 insn_idx = prog->reloc_desc[i].insn_idx; 1199 map_idx = prog->reloc_desc[i].map_idx; 1200 1201 if (insn_idx >= (int)prog->insns_cnt) { 1202 pr_warning("relocation out of range: '%s'\n", 1203 prog->section_name); 1204 return -LIBBPF_ERRNO__RELOC; 1205 } 1206 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD; 1207 insns[insn_idx].imm = obj->maps[map_idx].fd; 1208 } else { 1209 err = bpf_program__reloc_text(prog, obj, 1210 &prog->reloc_desc[i]); 1211 if (err) 1212 return err; 1213 } 1214 } 1215 1216 zfree(&prog->reloc_desc); 1217 prog->nr_reloc = 0; 1218 return 0; 1219 } 1220 1221 1222 static int 1223 bpf_object__relocate(struct bpf_object *obj) 1224 { 1225 struct bpf_program *prog; 1226 size_t i; 1227 int err; 1228 1229 for (i = 0; i < obj->nr_programs; i++) { 1230 prog = &obj->programs[i]; 1231 1232 err = bpf_program__relocate(prog, obj); 1233 if (err) { 1234 pr_warning("failed to relocate '%s'\n", 1235 prog->section_name); 1236 return err; 1237 } 1238 } 1239 return 0; 1240 } 1241 1242 static int bpf_object__collect_reloc(struct bpf_object *obj) 1243 { 1244 int i, err; 1245 1246 if (!obj_elf_valid(obj)) { 1247 pr_warning("Internal error: elf object is closed\n"); 1248 return -LIBBPF_ERRNO__INTERNAL; 1249 } 1250 1251 for (i = 0; i < obj->efile.nr_reloc; i++) { 1252 GElf_Shdr *shdr = &obj->efile.reloc[i].shdr; 1253 Elf_Data *data = obj->efile.reloc[i].data; 1254 int idx = shdr->sh_info; 1255 struct bpf_program *prog; 1256 1257 if (shdr->sh_type != SHT_REL) { 1258 pr_warning("internal error at %d\n", __LINE__); 1259 return -LIBBPF_ERRNO__INTERNAL; 1260 } 1261 1262 prog = bpf_object__find_prog_by_idx(obj, idx); 1263 if (!prog) { 1264 pr_warning("relocation failed: no section(%d)\n", idx); 1265 return -LIBBPF_ERRNO__RELOC; 1266 } 1267 1268 err = bpf_program__collect_reloc(prog, 1269 shdr, data, 1270 obj); 1271 if (err) 1272 return err; 1273 } 1274 return 0; 1275 } 1276 1277 static int 1278 load_program(enum bpf_prog_type type, enum bpf_attach_type expected_attach_type, 1279 const char *name, struct bpf_insn *insns, int insns_cnt, 1280 char *license, u32 kern_version, int *pfd, int prog_ifindex) 1281 { 1282 struct bpf_load_program_attr load_attr; 1283 char *log_buf; 1284 int ret; 1285 1286 memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); 1287 load_attr.prog_type = type; 1288 load_attr.expected_attach_type = expected_attach_type; 1289 load_attr.name = name; 1290 load_attr.insns = insns; 1291 load_attr.insns_cnt = insns_cnt; 1292 load_attr.license = license; 1293 load_attr.kern_version = kern_version; 1294 load_attr.prog_ifindex = prog_ifindex; 1295 1296 if (!load_attr.insns || !load_attr.insns_cnt) 1297 return -EINVAL; 1298 1299 log_buf = malloc(BPF_LOG_BUF_SIZE); 1300 if (!log_buf) 1301 pr_warning("Alloc log buffer for bpf loader error, continue without log\n"); 1302 1303 ret = bpf_load_program_xattr(&load_attr, log_buf, BPF_LOG_BUF_SIZE); 1304 1305 if (ret >= 0) { 1306 *pfd = ret; 1307 ret = 0; 1308 goto out; 1309 } 1310 1311 ret = -LIBBPF_ERRNO__LOAD; 1312 pr_warning("load bpf program failed: %s\n", strerror(errno)); 1313 1314 if (log_buf && log_buf[0] != '\0') { 1315 ret = -LIBBPF_ERRNO__VERIFY; 1316 pr_warning("-- BEGIN DUMP LOG ---\n"); 1317 pr_warning("\n%s\n", log_buf); 1318 pr_warning("-- END LOG --\n"); 1319 } else if (load_attr.insns_cnt >= BPF_MAXINSNS) { 1320 pr_warning("Program too large (%zu insns), at most %d insns\n", 1321 load_attr.insns_cnt, BPF_MAXINSNS); 1322 ret = -LIBBPF_ERRNO__PROG2BIG; 1323 } else { 1324 /* Wrong program type? */ 1325 if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) { 1326 int fd; 1327 1328 load_attr.prog_type = BPF_PROG_TYPE_KPROBE; 1329 load_attr.expected_attach_type = 0; 1330 fd = bpf_load_program_xattr(&load_attr, NULL, 0); 1331 if (fd >= 0) { 1332 close(fd); 1333 ret = -LIBBPF_ERRNO__PROGTYPE; 1334 goto out; 1335 } 1336 } 1337 1338 if (log_buf) 1339 ret = -LIBBPF_ERRNO__KVER; 1340 } 1341 1342 out: 1343 free(log_buf); 1344 return ret; 1345 } 1346 1347 static int 1348 bpf_program__load(struct bpf_program *prog, 1349 char *license, u32 kern_version) 1350 { 1351 int err = 0, fd, i; 1352 1353 if (prog->instances.nr < 0 || !prog->instances.fds) { 1354 if (prog->preprocessor) { 1355 pr_warning("Internal error: can't load program '%s'\n", 1356 prog->section_name); 1357 return -LIBBPF_ERRNO__INTERNAL; 1358 } 1359 1360 prog->instances.fds = malloc(sizeof(int)); 1361 if (!prog->instances.fds) { 1362 pr_warning("Not enough memory for BPF fds\n"); 1363 return -ENOMEM; 1364 } 1365 prog->instances.nr = 1; 1366 prog->instances.fds[0] = -1; 1367 } 1368 1369 if (!prog->preprocessor) { 1370 if (prog->instances.nr != 1) { 1371 pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n", 1372 prog->section_name, prog->instances.nr); 1373 } 1374 err = load_program(prog->type, prog->expected_attach_type, 1375 prog->name, prog->insns, prog->insns_cnt, 1376 license, kern_version, &fd, 1377 prog->prog_ifindex); 1378 if (!err) 1379 prog->instances.fds[0] = fd; 1380 goto out; 1381 } 1382 1383 for (i = 0; i < prog->instances.nr; i++) { 1384 struct bpf_prog_prep_result result; 1385 bpf_program_prep_t preprocessor = prog->preprocessor; 1386 1387 bzero(&result, sizeof(result)); 1388 err = preprocessor(prog, i, prog->insns, 1389 prog->insns_cnt, &result); 1390 if (err) { 1391 pr_warning("Preprocessing the %dth instance of program '%s' failed\n", 1392 i, prog->section_name); 1393 goto out; 1394 } 1395 1396 if (!result.new_insn_ptr || !result.new_insn_cnt) { 1397 pr_debug("Skip loading the %dth instance of program '%s'\n", 1398 i, prog->section_name); 1399 prog->instances.fds[i] = -1; 1400 if (result.pfd) 1401 *result.pfd = -1; 1402 continue; 1403 } 1404 1405 err = load_program(prog->type, prog->expected_attach_type, 1406 prog->name, result.new_insn_ptr, 1407 result.new_insn_cnt, 1408 license, kern_version, &fd, 1409 prog->prog_ifindex); 1410 1411 if (err) { 1412 pr_warning("Loading the %dth instance of program '%s' failed\n", 1413 i, prog->section_name); 1414 goto out; 1415 } 1416 1417 if (result.pfd) 1418 *result.pfd = fd; 1419 prog->instances.fds[i] = fd; 1420 } 1421 out: 1422 if (err) 1423 pr_warning("failed to load program '%s'\n", 1424 prog->section_name); 1425 zfree(&prog->insns); 1426 prog->insns_cnt = 0; 1427 return err; 1428 } 1429 1430 static bool bpf_program__is_function_storage(struct bpf_program *prog, 1431 struct bpf_object *obj) 1432 { 1433 return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls; 1434 } 1435 1436 static int 1437 bpf_object__load_progs(struct bpf_object *obj) 1438 { 1439 size_t i; 1440 int err; 1441 1442 for (i = 0; i < obj->nr_programs; i++) { 1443 if (bpf_program__is_function_storage(&obj->programs[i], obj)) 1444 continue; 1445 err = bpf_program__load(&obj->programs[i], 1446 obj->license, 1447 obj->kern_version); 1448 if (err) 1449 return err; 1450 } 1451 return 0; 1452 } 1453 1454 static bool bpf_prog_type__needs_kver(enum bpf_prog_type type) 1455 { 1456 switch (type) { 1457 case BPF_PROG_TYPE_SOCKET_FILTER: 1458 case BPF_PROG_TYPE_SCHED_CLS: 1459 case BPF_PROG_TYPE_SCHED_ACT: 1460 case BPF_PROG_TYPE_XDP: 1461 case BPF_PROG_TYPE_CGROUP_SKB: 1462 case BPF_PROG_TYPE_CGROUP_SOCK: 1463 case BPF_PROG_TYPE_LWT_IN: 1464 case BPF_PROG_TYPE_LWT_OUT: 1465 case BPF_PROG_TYPE_LWT_XMIT: 1466 case BPF_PROG_TYPE_LWT_SEG6LOCAL: 1467 case BPF_PROG_TYPE_SOCK_OPS: 1468 case BPF_PROG_TYPE_SK_SKB: 1469 case BPF_PROG_TYPE_CGROUP_DEVICE: 1470 case BPF_PROG_TYPE_SK_MSG: 1471 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: 1472 case BPF_PROG_TYPE_LIRC_MODE2: 1473 return false; 1474 case BPF_PROG_TYPE_UNSPEC: 1475 case BPF_PROG_TYPE_KPROBE: 1476 case BPF_PROG_TYPE_TRACEPOINT: 1477 case BPF_PROG_TYPE_PERF_EVENT: 1478 case BPF_PROG_TYPE_RAW_TRACEPOINT: 1479 default: 1480 return true; 1481 } 1482 } 1483 1484 static int bpf_object__validate(struct bpf_object *obj, bool needs_kver) 1485 { 1486 if (needs_kver && obj->kern_version == 0) { 1487 pr_warning("%s doesn't provide kernel version\n", 1488 obj->path); 1489 return -LIBBPF_ERRNO__KVERSION; 1490 } 1491 return 0; 1492 } 1493 1494 static struct bpf_object * 1495 __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz, 1496 bool needs_kver) 1497 { 1498 struct bpf_object *obj; 1499 int err; 1500 1501 if (elf_version(EV_CURRENT) == EV_NONE) { 1502 pr_warning("failed to init libelf for %s\n", path); 1503 return ERR_PTR(-LIBBPF_ERRNO__LIBELF); 1504 } 1505 1506 obj = bpf_object__new(path, obj_buf, obj_buf_sz); 1507 if (IS_ERR(obj)) 1508 return obj; 1509 1510 CHECK_ERR(bpf_object__elf_init(obj), err, out); 1511 CHECK_ERR(bpf_object__check_endianness(obj), err, out); 1512 CHECK_ERR(bpf_object__elf_collect(obj), err, out); 1513 CHECK_ERR(bpf_object__collect_reloc(obj), err, out); 1514 CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out); 1515 1516 bpf_object__elf_finish(obj); 1517 return obj; 1518 out: 1519 bpf_object__close(obj); 1520 return ERR_PTR(err); 1521 } 1522 1523 struct bpf_object *bpf_object__open(const char *path) 1524 { 1525 /* param validation */ 1526 if (!path) 1527 return NULL; 1528 1529 pr_debug("loading %s\n", path); 1530 1531 return __bpf_object__open(path, NULL, 0, true); 1532 } 1533 1534 struct bpf_object *bpf_object__open_buffer(void *obj_buf, 1535 size_t obj_buf_sz, 1536 const char *name) 1537 { 1538 char tmp_name[64]; 1539 1540 /* param validation */ 1541 if (!obj_buf || obj_buf_sz <= 0) 1542 return NULL; 1543 1544 if (!name) { 1545 snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx", 1546 (unsigned long)obj_buf, 1547 (unsigned long)obj_buf_sz); 1548 tmp_name[sizeof(tmp_name) - 1] = '\0'; 1549 name = tmp_name; 1550 } 1551 pr_debug("loading object '%s' from buffer\n", 1552 name); 1553 1554 return __bpf_object__open(name, obj_buf, obj_buf_sz, true); 1555 } 1556 1557 int bpf_object__unload(struct bpf_object *obj) 1558 { 1559 size_t i; 1560 1561 if (!obj) 1562 return -EINVAL; 1563 1564 for (i = 0; i < obj->nr_maps; i++) 1565 zclose(obj->maps[i].fd); 1566 1567 for (i = 0; i < obj->nr_programs; i++) 1568 bpf_program__unload(&obj->programs[i]); 1569 1570 return 0; 1571 } 1572 1573 int bpf_object__load(struct bpf_object *obj) 1574 { 1575 int err; 1576 1577 if (!obj) 1578 return -EINVAL; 1579 1580 if (obj->loaded) { 1581 pr_warning("object should not be loaded twice\n"); 1582 return -EINVAL; 1583 } 1584 1585 obj->loaded = true; 1586 1587 CHECK_ERR(bpf_object__create_maps(obj), err, out); 1588 CHECK_ERR(bpf_object__relocate(obj), err, out); 1589 CHECK_ERR(bpf_object__load_progs(obj), err, out); 1590 1591 return 0; 1592 out: 1593 bpf_object__unload(obj); 1594 pr_warning("failed to load object '%s'\n", obj->path); 1595 return err; 1596 } 1597 1598 static int check_path(const char *path) 1599 { 1600 struct statfs st_fs; 1601 char *dname, *dir; 1602 int err = 0; 1603 1604 if (path == NULL) 1605 return -EINVAL; 1606 1607 dname = strdup(path); 1608 if (dname == NULL) 1609 return -ENOMEM; 1610 1611 dir = dirname(dname); 1612 if (statfs(dir, &st_fs)) { 1613 pr_warning("failed to statfs %s: %s\n", dir, strerror(errno)); 1614 err = -errno; 1615 } 1616 free(dname); 1617 1618 if (!err && st_fs.f_type != BPF_FS_MAGIC) { 1619 pr_warning("specified path %s is not on BPF FS\n", path); 1620 err = -EINVAL; 1621 } 1622 1623 return err; 1624 } 1625 1626 int bpf_program__pin_instance(struct bpf_program *prog, const char *path, 1627 int instance) 1628 { 1629 int err; 1630 1631 err = check_path(path); 1632 if (err) 1633 return err; 1634 1635 if (prog == NULL) { 1636 pr_warning("invalid program pointer\n"); 1637 return -EINVAL; 1638 } 1639 1640 if (instance < 0 || instance >= prog->instances.nr) { 1641 pr_warning("invalid prog instance %d of prog %s (max %d)\n", 1642 instance, prog->section_name, prog->instances.nr); 1643 return -EINVAL; 1644 } 1645 1646 if (bpf_obj_pin(prog->instances.fds[instance], path)) { 1647 pr_warning("failed to pin program: %s\n", strerror(errno)); 1648 return -errno; 1649 } 1650 pr_debug("pinned program '%s'\n", path); 1651 1652 return 0; 1653 } 1654 1655 static int make_dir(const char *path) 1656 { 1657 int err = 0; 1658 1659 if (mkdir(path, 0700) && errno != EEXIST) 1660 err = -errno; 1661 1662 if (err) 1663 pr_warning("failed to mkdir %s: %s\n", path, strerror(-err)); 1664 return err; 1665 } 1666 1667 int bpf_program__pin(struct bpf_program *prog, const char *path) 1668 { 1669 int i, err; 1670 1671 err = check_path(path); 1672 if (err) 1673 return err; 1674 1675 if (prog == NULL) { 1676 pr_warning("invalid program pointer\n"); 1677 return -EINVAL; 1678 } 1679 1680 if (prog->instances.nr <= 0) { 1681 pr_warning("no instances of prog %s to pin\n", 1682 prog->section_name); 1683 return -EINVAL; 1684 } 1685 1686 err = make_dir(path); 1687 if (err) 1688 return err; 1689 1690 for (i = 0; i < prog->instances.nr; i++) { 1691 char buf[PATH_MAX]; 1692 int len; 1693 1694 len = snprintf(buf, PATH_MAX, "%s/%d", path, i); 1695 if (len < 0) 1696 return -EINVAL; 1697 else if (len >= PATH_MAX) 1698 return -ENAMETOOLONG; 1699 1700 err = bpf_program__pin_instance(prog, buf, i); 1701 if (err) 1702 return err; 1703 } 1704 1705 return 0; 1706 } 1707 1708 int bpf_map__pin(struct bpf_map *map, const char *path) 1709 { 1710 int err; 1711 1712 err = check_path(path); 1713 if (err) 1714 return err; 1715 1716 if (map == NULL) { 1717 pr_warning("invalid map pointer\n"); 1718 return -EINVAL; 1719 } 1720 1721 if (bpf_obj_pin(map->fd, path)) { 1722 pr_warning("failed to pin map: %s\n", strerror(errno)); 1723 return -errno; 1724 } 1725 1726 pr_debug("pinned map '%s'\n", path); 1727 return 0; 1728 } 1729 1730 int bpf_object__pin(struct bpf_object *obj, const char *path) 1731 { 1732 struct bpf_program *prog; 1733 struct bpf_map *map; 1734 int err; 1735 1736 if (!obj) 1737 return -ENOENT; 1738 1739 if (!obj->loaded) { 1740 pr_warning("object not yet loaded; load it first\n"); 1741 return -ENOENT; 1742 } 1743 1744 err = make_dir(path); 1745 if (err) 1746 return err; 1747 1748 bpf_map__for_each(map, obj) { 1749 char buf[PATH_MAX]; 1750 int len; 1751 1752 len = snprintf(buf, PATH_MAX, "%s/%s", path, 1753 bpf_map__name(map)); 1754 if (len < 0) 1755 return -EINVAL; 1756 else if (len >= PATH_MAX) 1757 return -ENAMETOOLONG; 1758 1759 err = bpf_map__pin(map, buf); 1760 if (err) 1761 return err; 1762 } 1763 1764 bpf_object__for_each_program(prog, obj) { 1765 char buf[PATH_MAX]; 1766 int len; 1767 1768 len = snprintf(buf, PATH_MAX, "%s/%s", path, 1769 prog->section_name); 1770 if (len < 0) 1771 return -EINVAL; 1772 else if (len >= PATH_MAX) 1773 return -ENAMETOOLONG; 1774 1775 err = bpf_program__pin(prog, buf); 1776 if (err) 1777 return err; 1778 } 1779 1780 return 0; 1781 } 1782 1783 void bpf_object__close(struct bpf_object *obj) 1784 { 1785 size_t i; 1786 1787 if (!obj) 1788 return; 1789 1790 if (obj->clear_priv) 1791 obj->clear_priv(obj, obj->priv); 1792 1793 bpf_object__elf_finish(obj); 1794 bpf_object__unload(obj); 1795 btf__free(obj->btf); 1796 1797 for (i = 0; i < obj->nr_maps; i++) { 1798 zfree(&obj->maps[i].name); 1799 if (obj->maps[i].clear_priv) 1800 obj->maps[i].clear_priv(&obj->maps[i], 1801 obj->maps[i].priv); 1802 obj->maps[i].priv = NULL; 1803 obj->maps[i].clear_priv = NULL; 1804 } 1805 zfree(&obj->maps); 1806 obj->nr_maps = 0; 1807 1808 if (obj->programs && obj->nr_programs) { 1809 for (i = 0; i < obj->nr_programs; i++) 1810 bpf_program__exit(&obj->programs[i]); 1811 } 1812 zfree(&obj->programs); 1813 1814 list_del(&obj->list); 1815 free(obj); 1816 } 1817 1818 struct bpf_object * 1819 bpf_object__next(struct bpf_object *prev) 1820 { 1821 struct bpf_object *next; 1822 1823 if (!prev) 1824 next = list_first_entry(&bpf_objects_list, 1825 struct bpf_object, 1826 list); 1827 else 1828 next = list_next_entry(prev, list); 1829 1830 /* Empty list is noticed here so don't need checking on entry. */ 1831 if (&next->list == &bpf_objects_list) 1832 return NULL; 1833 1834 return next; 1835 } 1836 1837 const char *bpf_object__name(struct bpf_object *obj) 1838 { 1839 return obj ? obj->path : ERR_PTR(-EINVAL); 1840 } 1841 1842 unsigned int bpf_object__kversion(struct bpf_object *obj) 1843 { 1844 return obj ? obj->kern_version : 0; 1845 } 1846 1847 int bpf_object__btf_fd(const struct bpf_object *obj) 1848 { 1849 return obj->btf ? btf__fd(obj->btf) : -1; 1850 } 1851 1852 int bpf_object__set_priv(struct bpf_object *obj, void *priv, 1853 bpf_object_clear_priv_t clear_priv) 1854 { 1855 if (obj->priv && obj->clear_priv) 1856 obj->clear_priv(obj, obj->priv); 1857 1858 obj->priv = priv; 1859 obj->clear_priv = clear_priv; 1860 return 0; 1861 } 1862 1863 void *bpf_object__priv(struct bpf_object *obj) 1864 { 1865 return obj ? obj->priv : ERR_PTR(-EINVAL); 1866 } 1867 1868 static struct bpf_program * 1869 __bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) 1870 { 1871 size_t idx; 1872 1873 if (!obj->programs) 1874 return NULL; 1875 /* First handler */ 1876 if (prev == NULL) 1877 return &obj->programs[0]; 1878 1879 if (prev->obj != obj) { 1880 pr_warning("error: program handler doesn't match object\n"); 1881 return NULL; 1882 } 1883 1884 idx = (prev - obj->programs) + 1; 1885 if (idx >= obj->nr_programs) 1886 return NULL; 1887 return &obj->programs[idx]; 1888 } 1889 1890 struct bpf_program * 1891 bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) 1892 { 1893 struct bpf_program *prog = prev; 1894 1895 do { 1896 prog = __bpf_program__next(prog, obj); 1897 } while (prog && bpf_program__is_function_storage(prog, obj)); 1898 1899 return prog; 1900 } 1901 1902 int bpf_program__set_priv(struct bpf_program *prog, void *priv, 1903 bpf_program_clear_priv_t clear_priv) 1904 { 1905 if (prog->priv && prog->clear_priv) 1906 prog->clear_priv(prog, prog->priv); 1907 1908 prog->priv = priv; 1909 prog->clear_priv = clear_priv; 1910 return 0; 1911 } 1912 1913 void *bpf_program__priv(struct bpf_program *prog) 1914 { 1915 return prog ? prog->priv : ERR_PTR(-EINVAL); 1916 } 1917 1918 void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex) 1919 { 1920 prog->prog_ifindex = ifindex; 1921 } 1922 1923 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy) 1924 { 1925 const char *title; 1926 1927 title = prog->section_name; 1928 if (needs_copy) { 1929 title = strdup(title); 1930 if (!title) { 1931 pr_warning("failed to strdup program title\n"); 1932 return ERR_PTR(-ENOMEM); 1933 } 1934 } 1935 1936 return title; 1937 } 1938 1939 int bpf_program__fd(struct bpf_program *prog) 1940 { 1941 return bpf_program__nth_fd(prog, 0); 1942 } 1943 1944 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, 1945 bpf_program_prep_t prep) 1946 { 1947 int *instances_fds; 1948 1949 if (nr_instances <= 0 || !prep) 1950 return -EINVAL; 1951 1952 if (prog->instances.nr > 0 || prog->instances.fds) { 1953 pr_warning("Can't set pre-processor after loading\n"); 1954 return -EINVAL; 1955 } 1956 1957 instances_fds = malloc(sizeof(int) * nr_instances); 1958 if (!instances_fds) { 1959 pr_warning("alloc memory failed for fds\n"); 1960 return -ENOMEM; 1961 } 1962 1963 /* fill all fd with -1 */ 1964 memset(instances_fds, -1, sizeof(int) * nr_instances); 1965 1966 prog->instances.nr = nr_instances; 1967 prog->instances.fds = instances_fds; 1968 prog->preprocessor = prep; 1969 return 0; 1970 } 1971 1972 int bpf_program__nth_fd(struct bpf_program *prog, int n) 1973 { 1974 int fd; 1975 1976 if (n >= prog->instances.nr || n < 0) { 1977 pr_warning("Can't get the %dth fd from program %s: only %d instances\n", 1978 n, prog->section_name, prog->instances.nr); 1979 return -EINVAL; 1980 } 1981 1982 fd = prog->instances.fds[n]; 1983 if (fd < 0) { 1984 pr_warning("%dth instance of program '%s' is invalid\n", 1985 n, prog->section_name); 1986 return -ENOENT; 1987 } 1988 1989 return fd; 1990 } 1991 1992 void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) 1993 { 1994 prog->type = type; 1995 } 1996 1997 static bool bpf_program__is_type(struct bpf_program *prog, 1998 enum bpf_prog_type type) 1999 { 2000 return prog ? (prog->type == type) : false; 2001 } 2002 2003 #define BPF_PROG_TYPE_FNS(NAME, TYPE) \ 2004 int bpf_program__set_##NAME(struct bpf_program *prog) \ 2005 { \ 2006 if (!prog) \ 2007 return -EINVAL; \ 2008 bpf_program__set_type(prog, TYPE); \ 2009 return 0; \ 2010 } \ 2011 \ 2012 bool bpf_program__is_##NAME(struct bpf_program *prog) \ 2013 { \ 2014 return bpf_program__is_type(prog, TYPE); \ 2015 } \ 2016 2017 BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER); 2018 BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE); 2019 BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS); 2020 BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT); 2021 BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT); 2022 BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT); 2023 BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP); 2024 BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT); 2025 2026 void bpf_program__set_expected_attach_type(struct bpf_program *prog, 2027 enum bpf_attach_type type) 2028 { 2029 prog->expected_attach_type = type; 2030 } 2031 2032 #define BPF_PROG_SEC_FULL(string, ptype, atype) \ 2033 { string, sizeof(string) - 1, ptype, atype } 2034 2035 #define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_FULL(string, ptype, 0) 2036 2037 #define BPF_S_PROG_SEC(string, ptype) \ 2038 BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK, ptype) 2039 2040 #define BPF_SA_PROG_SEC(string, ptype) \ 2041 BPF_PROG_SEC_FULL(string, BPF_PROG_TYPE_CGROUP_SOCK_ADDR, ptype) 2042 2043 static const struct { 2044 const char *sec; 2045 size_t len; 2046 enum bpf_prog_type prog_type; 2047 enum bpf_attach_type expected_attach_type; 2048 } section_names[] = { 2049 BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER), 2050 BPF_PROG_SEC("kprobe/", BPF_PROG_TYPE_KPROBE), 2051 BPF_PROG_SEC("kretprobe/", BPF_PROG_TYPE_KPROBE), 2052 BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS), 2053 BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT), 2054 BPF_PROG_SEC("tracepoint/", BPF_PROG_TYPE_TRACEPOINT), 2055 BPF_PROG_SEC("raw_tracepoint/", BPF_PROG_TYPE_RAW_TRACEPOINT), 2056 BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP), 2057 BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT), 2058 BPF_PROG_SEC("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB), 2059 BPF_PROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK), 2060 BPF_PROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE), 2061 BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN), 2062 BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT), 2063 BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT), 2064 BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL), 2065 BPF_PROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS), 2066 BPF_PROG_SEC("sk_skb", BPF_PROG_TYPE_SK_SKB), 2067 BPF_PROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG), 2068 BPF_PROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2), 2069 BPF_SA_PROG_SEC("cgroup/bind4", BPF_CGROUP_INET4_BIND), 2070 BPF_SA_PROG_SEC("cgroup/bind6", BPF_CGROUP_INET6_BIND), 2071 BPF_SA_PROG_SEC("cgroup/connect4", BPF_CGROUP_INET4_CONNECT), 2072 BPF_SA_PROG_SEC("cgroup/connect6", BPF_CGROUP_INET6_CONNECT), 2073 BPF_SA_PROG_SEC("cgroup/sendmsg4", BPF_CGROUP_UDP4_SENDMSG), 2074 BPF_SA_PROG_SEC("cgroup/sendmsg6", BPF_CGROUP_UDP6_SENDMSG), 2075 BPF_S_PROG_SEC("cgroup/post_bind4", BPF_CGROUP_INET4_POST_BIND), 2076 BPF_S_PROG_SEC("cgroup/post_bind6", BPF_CGROUP_INET6_POST_BIND), 2077 }; 2078 2079 #undef BPF_PROG_SEC 2080 #undef BPF_PROG_SEC_FULL 2081 #undef BPF_S_PROG_SEC 2082 #undef BPF_SA_PROG_SEC 2083 2084 static int bpf_program__identify_section(struct bpf_program *prog) 2085 { 2086 int i; 2087 2088 if (!prog->section_name) 2089 goto err; 2090 2091 for (i = 0; i < ARRAY_SIZE(section_names); i++) 2092 if (strncmp(prog->section_name, section_names[i].sec, 2093 section_names[i].len) == 0) 2094 return i; 2095 2096 err: 2097 pr_warning("failed to guess program type based on section name %s\n", 2098 prog->section_name); 2099 2100 return -1; 2101 } 2102 2103 int bpf_map__fd(struct bpf_map *map) 2104 { 2105 return map ? map->fd : -EINVAL; 2106 } 2107 2108 const struct bpf_map_def *bpf_map__def(struct bpf_map *map) 2109 { 2110 return map ? &map->def : ERR_PTR(-EINVAL); 2111 } 2112 2113 const char *bpf_map__name(struct bpf_map *map) 2114 { 2115 return map ? map->name : NULL; 2116 } 2117 2118 uint32_t bpf_map__btf_key_type_id(const struct bpf_map *map) 2119 { 2120 return map ? map->btf_key_type_id : 0; 2121 } 2122 2123 uint32_t bpf_map__btf_value_type_id(const struct bpf_map *map) 2124 { 2125 return map ? map->btf_value_type_id : 0; 2126 } 2127 2128 int bpf_map__set_priv(struct bpf_map *map, void *priv, 2129 bpf_map_clear_priv_t clear_priv) 2130 { 2131 if (!map) 2132 return -EINVAL; 2133 2134 if (map->priv) { 2135 if (map->clear_priv) 2136 map->clear_priv(map, map->priv); 2137 } 2138 2139 map->priv = priv; 2140 map->clear_priv = clear_priv; 2141 return 0; 2142 } 2143 2144 void *bpf_map__priv(struct bpf_map *map) 2145 { 2146 return map ? map->priv : ERR_PTR(-EINVAL); 2147 } 2148 2149 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex) 2150 { 2151 map->map_ifindex = ifindex; 2152 } 2153 2154 struct bpf_map * 2155 bpf_map__next(struct bpf_map *prev, struct bpf_object *obj) 2156 { 2157 size_t idx; 2158 struct bpf_map *s, *e; 2159 2160 if (!obj || !obj->maps) 2161 return NULL; 2162 2163 s = obj->maps; 2164 e = obj->maps + obj->nr_maps; 2165 2166 if (prev == NULL) 2167 return s; 2168 2169 if ((prev < s) || (prev >= e)) { 2170 pr_warning("error in %s: map handler doesn't belong to object\n", 2171 __func__); 2172 return NULL; 2173 } 2174 2175 idx = (prev - obj->maps) + 1; 2176 if (idx >= obj->nr_maps) 2177 return NULL; 2178 return &obj->maps[idx]; 2179 } 2180 2181 struct bpf_map * 2182 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name) 2183 { 2184 struct bpf_map *pos; 2185 2186 bpf_map__for_each(pos, obj) { 2187 if (pos->name && !strcmp(pos->name, name)) 2188 return pos; 2189 } 2190 return NULL; 2191 } 2192 2193 struct bpf_map * 2194 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) 2195 { 2196 int i; 2197 2198 for (i = 0; i < obj->nr_maps; i++) { 2199 if (obj->maps[i].offset == offset) 2200 return &obj->maps[i]; 2201 } 2202 return ERR_PTR(-ENOENT); 2203 } 2204 2205 long libbpf_get_error(const void *ptr) 2206 { 2207 if (IS_ERR(ptr)) 2208 return PTR_ERR(ptr); 2209 return 0; 2210 } 2211 2212 int bpf_prog_load(const char *file, enum bpf_prog_type type, 2213 struct bpf_object **pobj, int *prog_fd) 2214 { 2215 struct bpf_prog_load_attr attr; 2216 2217 memset(&attr, 0, sizeof(struct bpf_prog_load_attr)); 2218 attr.file = file; 2219 attr.prog_type = type; 2220 attr.expected_attach_type = 0; 2221 2222 return bpf_prog_load_xattr(&attr, pobj, prog_fd); 2223 } 2224 2225 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 2226 struct bpf_object **pobj, int *prog_fd) 2227 { 2228 struct bpf_program *prog, *first_prog = NULL; 2229 enum bpf_attach_type expected_attach_type; 2230 enum bpf_prog_type prog_type; 2231 struct bpf_object *obj; 2232 struct bpf_map *map; 2233 int section_idx; 2234 int err; 2235 2236 if (!attr) 2237 return -EINVAL; 2238 if (!attr->file) 2239 return -EINVAL; 2240 2241 obj = __bpf_object__open(attr->file, NULL, 0, 2242 bpf_prog_type__needs_kver(attr->prog_type)); 2243 if (IS_ERR_OR_NULL(obj)) 2244 return -ENOENT; 2245 2246 bpf_object__for_each_program(prog, obj) { 2247 /* 2248 * If type is not specified, try to guess it based on 2249 * section name. 2250 */ 2251 prog_type = attr->prog_type; 2252 prog->prog_ifindex = attr->ifindex; 2253 expected_attach_type = attr->expected_attach_type; 2254 if (prog_type == BPF_PROG_TYPE_UNSPEC) { 2255 section_idx = bpf_program__identify_section(prog); 2256 if (section_idx < 0) { 2257 bpf_object__close(obj); 2258 return -EINVAL; 2259 } 2260 prog_type = section_names[section_idx].prog_type; 2261 expected_attach_type = 2262 section_names[section_idx].expected_attach_type; 2263 } 2264 2265 bpf_program__set_type(prog, prog_type); 2266 bpf_program__set_expected_attach_type(prog, 2267 expected_attach_type); 2268 2269 if (!bpf_program__is_function_storage(prog, obj) && !first_prog) 2270 first_prog = prog; 2271 } 2272 2273 bpf_map__for_each(map, obj) { 2274 map->map_ifindex = attr->ifindex; 2275 } 2276 2277 if (!first_prog) { 2278 pr_warning("object file doesn't contain bpf program\n"); 2279 bpf_object__close(obj); 2280 return -ENOENT; 2281 } 2282 2283 err = bpf_object__load(obj); 2284 if (err) { 2285 bpf_object__close(obj); 2286 return -EINVAL; 2287 } 2288 2289 *pobj = obj; 2290 *prog_fd = bpf_program__fd(first_prog); 2291 return 0; 2292 } 2293 2294 enum bpf_perf_event_ret 2295 bpf_perf_event_read_simple(void *mem, unsigned long size, 2296 unsigned long page_size, void **buf, size_t *buf_len, 2297 bpf_perf_event_print_t fn, void *priv) 2298 { 2299 volatile struct perf_event_mmap_page *header = mem; 2300 __u64 data_tail = header->data_tail; 2301 __u64 data_head = header->data_head; 2302 void *base, *begin, *end; 2303 int ret; 2304 2305 asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ 2306 if (data_head == data_tail) 2307 return LIBBPF_PERF_EVENT_CONT; 2308 2309 base = ((char *)header) + page_size; 2310 2311 begin = base + data_tail % size; 2312 end = base + data_head % size; 2313 2314 while (begin != end) { 2315 struct perf_event_header *ehdr; 2316 2317 ehdr = begin; 2318 if (begin + ehdr->size > base + size) { 2319 long len = base + size - begin; 2320 2321 if (*buf_len < ehdr->size) { 2322 free(*buf); 2323 *buf = malloc(ehdr->size); 2324 if (!*buf) { 2325 ret = LIBBPF_PERF_EVENT_ERROR; 2326 break; 2327 } 2328 *buf_len = ehdr->size; 2329 } 2330 2331 memcpy(*buf, begin, len); 2332 memcpy(*buf + len, base, ehdr->size - len); 2333 ehdr = (void *)*buf; 2334 begin = base + ehdr->size - len; 2335 } else if (begin + ehdr->size == base + size) { 2336 begin = base; 2337 } else { 2338 begin += ehdr->size; 2339 } 2340 2341 ret = fn(ehdr, priv); 2342 if (ret != LIBBPF_PERF_EVENT_CONT) 2343 break; 2344 2345 data_tail += ehdr->size; 2346 } 2347 2348 __sync_synchronize(); /* smp_mb() */ 2349 header->data_tail = data_tail; 2350 2351 return ret; 2352 } 2353