2 * Common eBPF ELF object loading operations.
4 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
5 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
6 * Copyright (C) 2015 Huawei Inc.
17 #include <asm/unistd.h>
18 #include <linux/kernel.h>
19 #include <linux/bpf.h>
20 #include <linux/list.h>
27 #define __printf(a, b) __attribute__((format(printf, a, b)))
30 static int __base_pr(const char *format, ...)
35 va_start(args, format);
36 err = vfprintf(stderr, format, args);
41 static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
42 static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
43 static __printf(1, 2) libbpf_print_fn_t __pr_debug;
45 #define __pr(func, fmt, ...) \
48 (func)("libbpf: " fmt, ##__VA_ARGS__); \
51 #define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
52 #define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__)
53 #define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__)
55 void libbpf_set_print(libbpf_print_fn_t warn,
56 libbpf_print_fn_t info,
57 libbpf_print_fn_t debug)
64 #define STRERR_BUFSIZE 128
66 #define ERRNO_OFFSET(e) ((e) - __LIBBPF_ERRNO__START)
67 #define ERRCODE_OFFSET(c) ERRNO_OFFSET(LIBBPF_ERRNO__##c)
68 #define NR_ERRNO (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)
70 static const char *libbpf_strerror_table[NR_ERRNO] = {
71 [ERRCODE_OFFSET(LIBELF)] = "Something wrong in libelf",
72 [ERRCODE_OFFSET(FORMAT)] = "BPF object format invalid",
73 [ERRCODE_OFFSET(KVERSION)] = "'version' section incorrect or lost",
74 [ERRCODE_OFFSET(ENDIAN)] = "Endian missmatch",
75 [ERRCODE_OFFSET(INTERNAL)] = "Internal error in libbpf",
76 [ERRCODE_OFFSET(RELOC)] = "Relocation failed",
77 [ERRCODE_OFFSET(VERIFY)] = "Kernel verifier blocks program loading",
78 [ERRCODE_OFFSET(PROG2BIG)] = "Program too big",
79 [ERRCODE_OFFSET(KVER)] = "Incorrect kernel version",
82 int libbpf_strerror(int err, char *buf, size_t size)
87 err = err > 0 ? err : -err;
89 if (err < __LIBBPF_ERRNO__START) {
92 ret = strerror_r(err, buf, size);
97 if (err < __LIBBPF_ERRNO__END) {
100 msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
101 snprintf(buf, size, "%s", msg);
102 buf[size - 1] = '\0';
106 snprintf(buf, size, "Unknown libbpf error %d", err);
107 buf[size - 1] = '\0';
111 #define CHECK_ERR(action, err, out) do { \
118 /* Copied from tools/perf/util/util.h */
120 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
124 # define zclose(fd) ({ \
127 ___err = close((fd)); \
132 #ifdef HAVE_LIBELF_MMAP_SUPPORT
133 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
135 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
139 * bpf_prog should be a better name but it has been used in
143 /* Index in elf obj file, for relocation use. */
146 struct bpf_insn *insns;
159 bpf_program_prep_t preprocessor;
161 struct bpf_object *obj;
163 bpf_program_clear_priv_t clear_priv;
169 struct bpf_map_def def;
171 bpf_map_clear_priv_t clear_priv;
174 static LIST_HEAD(bpf_objects_list);
180 struct bpf_program *programs;
182 struct bpf_map *maps;
188 * Information when doing elf related work. Only valid if fd
207 * All loaded bpf_object is linked in a list, which is
208 * hidden to caller. bpf_objects__<func> handlers deal with
211 struct list_head list;
214 #define obj_elf_valid(o) ((o)->efile.elf)
216 static void bpf_program__unload(struct bpf_program *prog)
224 * If the object is opened but the program was never loaded,
225 * it is possible that prog->instances.nr == -1.
227 if (prog->instances.nr > 0) {
228 for (i = 0; i < prog->instances.nr; i++)
229 zclose(prog->instances.fds[i]);
230 } else if (prog->instances.nr != -1) {
231 pr_warning("Internal error: instances.nr is %d\n",
235 prog->instances.nr = -1;
236 zfree(&prog->instances.fds);
239 static void bpf_program__exit(struct bpf_program *prog)
244 if (prog->clear_priv)
245 prog->clear_priv(prog, prog->priv);
248 prog->clear_priv = NULL;
250 bpf_program__unload(prog);
251 zfree(&prog->section_name);
253 zfree(&prog->reloc_desc);
261 bpf_program__init(void *data, size_t size, char *name, int idx,
262 struct bpf_program *prog)
264 if (size < sizeof(struct bpf_insn)) {
265 pr_warning("corrupted section '%s'\n", name);
269 bzero(prog, sizeof(*prog));
271 prog->section_name = strdup(name);
272 if (!prog->section_name) {
273 pr_warning("failed to alloc name for prog %s\n",
278 prog->insns = malloc(size);
280 pr_warning("failed to alloc insns for %s\n", name);
283 prog->insns_cnt = size / sizeof(struct bpf_insn);
284 memcpy(prog->insns, data,
285 prog->insns_cnt * sizeof(struct bpf_insn));
287 prog->instances.fds = NULL;
288 prog->instances.nr = -1;
292 bpf_program__exit(prog);
297 bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
300 struct bpf_program prog, *progs;
303 err = bpf_program__init(data, size, name, idx, &prog);
307 progs = obj->programs;
308 nr_progs = obj->nr_programs;
310 progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
313 * In this case the original obj->programs
314 * is still valid, so don't need special treat for
315 * bpf_close_object().
317 pr_warning("failed to alloc a new program '%s'\n",
319 bpf_program__exit(&prog);
323 pr_debug("found program %s\n", prog.section_name);
324 obj->programs = progs;
325 obj->nr_programs = nr_progs + 1;
327 progs[nr_progs] = prog;
331 static struct bpf_object *bpf_object__new(const char *path,
335 struct bpf_object *obj;
337 obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
339 pr_warning("alloc memory failed for %s\n", path);
340 return ERR_PTR(-ENOMEM);
343 strcpy(obj->path, path);
347 * Caller of this function should also calls
348 * bpf_object__elf_finish() after data collection to return
349 * obj_buf to user. If not, we should duplicate the buffer to
350 * avoid user freeing them before elf finish.
352 obj->efile.obj_buf = obj_buf;
353 obj->efile.obj_buf_sz = obj_buf_sz;
354 obj->efile.maps_shndx = -1;
358 INIT_LIST_HEAD(&obj->list);
359 list_add(&obj->list, &bpf_objects_list);
363 static void bpf_object__elf_finish(struct bpf_object *obj)
365 if (!obj_elf_valid(obj))
368 if (obj->efile.elf) {
369 elf_end(obj->efile.elf);
370 obj->efile.elf = NULL;
372 obj->efile.symbols = NULL;
374 zfree(&obj->efile.reloc);
375 obj->efile.nr_reloc = 0;
376 zclose(obj->efile.fd);
377 obj->efile.obj_buf = NULL;
378 obj->efile.obj_buf_sz = 0;
381 static int bpf_object__elf_init(struct bpf_object *obj)
386 if (obj_elf_valid(obj)) {
387 pr_warning("elf init: internal error\n");
388 return -LIBBPF_ERRNO__LIBELF;
391 if (obj->efile.obj_buf_sz > 0) {
393 * obj_buf should have been validated by
394 * bpf_object__open_buffer().
396 obj->efile.elf = elf_memory(obj->efile.obj_buf,
397 obj->efile.obj_buf_sz);
399 obj->efile.fd = open(obj->path, O_RDONLY);
400 if (obj->efile.fd < 0) {
401 pr_warning("failed to open %s: %s\n", obj->path,
406 obj->efile.elf = elf_begin(obj->efile.fd,
407 LIBBPF_ELF_C_READ_MMAP,
411 if (!obj->efile.elf) {
412 pr_warning("failed to open %s as ELF file\n",
414 err = -LIBBPF_ERRNO__LIBELF;
418 if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
419 pr_warning("failed to get EHDR from %s\n",
421 err = -LIBBPF_ERRNO__FORMAT;
424 ep = &obj->efile.ehdr;
426 if ((ep->e_type != ET_REL) || (ep->e_machine != 0)) {
427 pr_warning("%s is not an eBPF object file\n",
429 err = -LIBBPF_ERRNO__FORMAT;
435 bpf_object__elf_finish(obj);
440 bpf_object__check_endianness(struct bpf_object *obj)
442 static unsigned int const endian = 1;
444 switch (obj->efile.ehdr.e_ident[EI_DATA]) {
446 /* We are big endian, BPF obj is little endian. */
447 if (*(unsigned char const *)&endian != 1)
452 /* We are little endian, BPF obj is big endian. */
453 if (*(unsigned char const *)&endian != 0)
457 return -LIBBPF_ERRNO__ENDIAN;
463 pr_warning("Error: endianness mismatch.\n");
464 return -LIBBPF_ERRNO__ENDIAN;
468 bpf_object__init_license(struct bpf_object *obj,
469 void *data, size_t size)
471 memcpy(obj->license, data,
472 min(size, sizeof(obj->license) - 1));
473 pr_debug("license of %s is %s\n", obj->path, obj->license);
478 bpf_object__init_kversion(struct bpf_object *obj,
479 void *data, size_t size)
483 if (size != sizeof(kver)) {
484 pr_warning("invalid kver section in %s\n", obj->path);
485 return -LIBBPF_ERRNO__FORMAT;
487 memcpy(&kver, data, sizeof(kver));
488 obj->kern_version = kver;
489 pr_debug("kernel version of %s is %x\n", obj->path,
495 bpf_object__init_maps(struct bpf_object *obj, void *data,
501 nr_maps = size / sizeof(struct bpf_map_def);
502 if (!data || !nr_maps) {
503 pr_debug("%s doesn't need map definition\n",
508 pr_debug("maps in %s: %zd bytes\n", obj->path, size);
510 obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
512 pr_warning("alloc maps for object failed\n");
515 obj->nr_maps = nr_maps;
517 for (i = 0; i < nr_maps; i++) {
518 struct bpf_map_def *def = &obj->maps[i].def;
521 * fill all fd with -1 so won't close incorrect
522 * fd (fd=0 is stdin) when failure (zclose won't close
525 obj->maps[i].fd = -1;
527 /* Save map definition into obj->maps */
528 *def = ((struct bpf_map_def *)data)[i];
534 bpf_object__init_maps_name(struct bpf_object *obj)
537 Elf_Data *symbols = obj->efile.symbols;
539 if (!symbols || obj->efile.maps_shndx < 0)
542 for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
545 const char *map_name;
547 if (!gelf_getsym(symbols, i, &sym))
549 if (sym.st_shndx != obj->efile.maps_shndx)
552 map_name = elf_strptr(obj->efile.elf,
553 obj->efile.strtabidx,
555 map_idx = sym.st_value / sizeof(struct bpf_map_def);
556 if (map_idx >= obj->nr_maps) {
557 pr_warning("index of map \"%s\" is buggy: %zu > %zu\n",
558 map_name, map_idx, obj->nr_maps);
561 obj->maps[map_idx].name = strdup(map_name);
562 if (!obj->maps[map_idx].name) {
563 pr_warning("failed to alloc map name\n");
566 pr_debug("map %zu is \"%s\"\n", map_idx,
567 obj->maps[map_idx].name);
572 static int bpf_object__elf_collect(struct bpf_object *obj)
574 Elf *elf = obj->efile.elf;
575 GElf_Ehdr *ep = &obj->efile.ehdr;
577 int idx = 0, err = 0;
579 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
580 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
581 pr_warning("failed to get e_shstrndx from %s\n",
583 return -LIBBPF_ERRNO__FORMAT;
586 while ((scn = elf_nextscn(elf, scn)) != NULL) {
592 if (gelf_getshdr(scn, &sh) != &sh) {
593 pr_warning("failed to get section header from %s\n",
595 err = -LIBBPF_ERRNO__FORMAT;
599 name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
601 pr_warning("failed to get section name from %s\n",
603 err = -LIBBPF_ERRNO__FORMAT;
607 data = elf_getdata(scn, 0);
609 pr_warning("failed to get section data from %s(%s)\n",
611 err = -LIBBPF_ERRNO__FORMAT;
614 pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n",
615 name, (unsigned long)data->d_size,
616 (int)sh.sh_link, (unsigned long)sh.sh_flags,
619 if (strcmp(name, "license") == 0)
620 err = bpf_object__init_license(obj,
623 else if (strcmp(name, "version") == 0)
624 err = bpf_object__init_kversion(obj,
627 else if (strcmp(name, "maps") == 0) {
628 err = bpf_object__init_maps(obj, data->d_buf,
630 obj->efile.maps_shndx = idx;
631 } else if (sh.sh_type == SHT_SYMTAB) {
632 if (obj->efile.symbols) {
633 pr_warning("bpf: multiple SYMTAB in %s\n",
635 err = -LIBBPF_ERRNO__FORMAT;
637 obj->efile.symbols = data;
638 obj->efile.strtabidx = sh.sh_link;
640 } else if ((sh.sh_type == SHT_PROGBITS) &&
641 (sh.sh_flags & SHF_EXECINSTR) &&
642 (data->d_size > 0)) {
643 err = bpf_object__add_program(obj, data->d_buf,
644 data->d_size, name, idx);
646 char errmsg[STRERR_BUFSIZE];
648 strerror_r(-err, errmsg, sizeof(errmsg));
649 pr_warning("failed to alloc program %s (%s): %s",
650 name, obj->path, errmsg);
652 } else if (sh.sh_type == SHT_REL) {
653 void *reloc = obj->efile.reloc;
654 int nr_reloc = obj->efile.nr_reloc + 1;
656 reloc = realloc(reloc,
657 sizeof(*obj->efile.reloc) * nr_reloc);
659 pr_warning("realloc failed\n");
662 int n = nr_reloc - 1;
664 obj->efile.reloc = reloc;
665 obj->efile.nr_reloc = nr_reloc;
667 obj->efile.reloc[n].shdr = sh;
668 obj->efile.reloc[n].data = data;
675 if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) {
676 pr_warning("Corrupted ELF file: index of strtab invalid\n");
677 return LIBBPF_ERRNO__FORMAT;
679 if (obj->efile.maps_shndx >= 0)
680 err = bpf_object__init_maps_name(obj);
685 static struct bpf_program *
686 bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
688 struct bpf_program *prog;
691 for (i = 0; i < obj->nr_programs; i++) {
692 prog = &obj->programs[i];
693 if (prog->idx == idx)
700 bpf_program__collect_reloc(struct bpf_program *prog,
701 size_t nr_maps, GElf_Shdr *shdr,
702 Elf_Data *data, Elf_Data *symbols,
707 pr_debug("collecting relocating info for: '%s'\n",
709 nrels = shdr->sh_size / shdr->sh_entsize;
711 prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
712 if (!prog->reloc_desc) {
713 pr_warning("failed to alloc memory in relocation\n");
716 prog->nr_reloc = nrels;
718 for (i = 0; i < nrels; i++) {
721 unsigned int insn_idx;
722 struct bpf_insn *insns = prog->insns;
725 if (!gelf_getrel(data, i, &rel)) {
726 pr_warning("relocation: failed to get %d reloc\n", i);
727 return -LIBBPF_ERRNO__FORMAT;
730 if (!gelf_getsym(symbols,
731 GELF_R_SYM(rel.r_info),
733 pr_warning("relocation: symbol %"PRIx64" not found\n",
734 GELF_R_SYM(rel.r_info));
735 return -LIBBPF_ERRNO__FORMAT;
738 if (sym.st_shndx != maps_shndx) {
739 pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n",
740 prog->section_name, sym.st_shndx);
741 return -LIBBPF_ERRNO__RELOC;
744 insn_idx = rel.r_offset / sizeof(struct bpf_insn);
745 pr_debug("relocation: insn_idx=%u\n", insn_idx);
747 if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
748 pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
749 insn_idx, insns[insn_idx].code);
750 return -LIBBPF_ERRNO__RELOC;
753 map_idx = sym.st_value / sizeof(struct bpf_map_def);
754 if (map_idx >= nr_maps) {
755 pr_warning("bpf relocation: map_idx %d large than %d\n",
756 (int)map_idx, (int)nr_maps - 1);
757 return -LIBBPF_ERRNO__RELOC;
760 prog->reloc_desc[i].insn_idx = insn_idx;
761 prog->reloc_desc[i].map_idx = map_idx;
767 bpf_object__create_maps(struct bpf_object *obj)
771 for (i = 0; i < obj->nr_maps; i++) {
772 struct bpf_map_def *def = &obj->maps[i].def;
773 int *pfd = &obj->maps[i].fd;
775 *pfd = bpf_create_map(def->type,
783 pr_warning("failed to create map: %s\n",
785 for (j = 0; j < i; j++)
786 zclose(obj->maps[j].fd);
789 pr_debug("create map: fd=%d\n", *pfd);
796 bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
800 if (!prog || !prog->reloc_desc)
803 for (i = 0; i < prog->nr_reloc; i++) {
804 int insn_idx, map_idx;
805 struct bpf_insn *insns = prog->insns;
807 insn_idx = prog->reloc_desc[i].insn_idx;
808 map_idx = prog->reloc_desc[i].map_idx;
810 if (insn_idx >= (int)prog->insns_cnt) {
811 pr_warning("relocation out of range: '%s'\n",
813 return -LIBBPF_ERRNO__RELOC;
815 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
816 insns[insn_idx].imm = obj->maps[map_idx].fd;
819 zfree(&prog->reloc_desc);
826 bpf_object__relocate(struct bpf_object *obj)
828 struct bpf_program *prog;
832 for (i = 0; i < obj->nr_programs; i++) {
833 prog = &obj->programs[i];
835 err = bpf_program__relocate(prog, obj);
837 pr_warning("failed to relocate '%s'\n",
845 static int bpf_object__collect_reloc(struct bpf_object *obj)
849 if (!obj_elf_valid(obj)) {
850 pr_warning("Internal error: elf object is closed\n");
851 return -LIBBPF_ERRNO__INTERNAL;
854 for (i = 0; i < obj->efile.nr_reloc; i++) {
855 GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
856 Elf_Data *data = obj->efile.reloc[i].data;
857 int idx = shdr->sh_info;
858 struct bpf_program *prog;
859 size_t nr_maps = obj->nr_maps;
861 if (shdr->sh_type != SHT_REL) {
862 pr_warning("internal error at %d\n", __LINE__);
863 return -LIBBPF_ERRNO__INTERNAL;
866 prog = bpf_object__find_prog_by_idx(obj, idx);
868 pr_warning("relocation failed: no %d section\n",
870 return -LIBBPF_ERRNO__RELOC;
873 err = bpf_program__collect_reloc(prog, nr_maps,
876 obj->efile.maps_shndx);
884 load_program(struct bpf_insn *insns, int insns_cnt,
885 char *license, u32 kern_version, int *pfd)
890 if (!insns || !insns_cnt)
893 log_buf = malloc(BPF_LOG_BUF_SIZE);
895 pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
897 ret = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
898 insns_cnt, license, kern_version,
899 log_buf, BPF_LOG_BUF_SIZE);
907 ret = -LIBBPF_ERRNO__LOAD;
908 pr_warning("load bpf program failed: %s\n", strerror(errno));
910 if (log_buf && log_buf[0] != '\0') {
911 ret = -LIBBPF_ERRNO__VERIFY;
912 pr_warning("-- BEGIN DUMP LOG ---\n");
913 pr_warning("\n%s\n", log_buf);
914 pr_warning("-- END LOG --\n");
916 if (insns_cnt >= BPF_MAXINSNS) {
917 pr_warning("Program too large (%d insns), at most %d insns\n",
918 insns_cnt, BPF_MAXINSNS);
919 ret = -LIBBPF_ERRNO__PROG2BIG;
920 } else if (log_buf) {
921 pr_warning("log buffer is empty\n");
922 ret = -LIBBPF_ERRNO__KVER;
932 bpf_program__load(struct bpf_program *prog,
933 char *license, u32 kern_version)
937 if (prog->instances.nr < 0 || !prog->instances.fds) {
938 if (prog->preprocessor) {
939 pr_warning("Internal error: can't load program '%s'\n",
941 return -LIBBPF_ERRNO__INTERNAL;
944 prog->instances.fds = malloc(sizeof(int));
945 if (!prog->instances.fds) {
946 pr_warning("Not enough memory for BPF fds\n");
949 prog->instances.nr = 1;
950 prog->instances.fds[0] = -1;
953 if (!prog->preprocessor) {
954 if (prog->instances.nr != 1) {
955 pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
956 prog->section_name, prog->instances.nr);
958 err = load_program(prog->insns, prog->insns_cnt,
959 license, kern_version, &fd);
961 prog->instances.fds[0] = fd;
965 for (i = 0; i < prog->instances.nr; i++) {
966 struct bpf_prog_prep_result result;
967 bpf_program_prep_t preprocessor = prog->preprocessor;
969 bzero(&result, sizeof(result));
970 err = preprocessor(prog, i, prog->insns,
971 prog->insns_cnt, &result);
973 pr_warning("Preprocessing the %dth instance of program '%s' failed\n",
974 i, prog->section_name);
978 if (!result.new_insn_ptr || !result.new_insn_cnt) {
979 pr_debug("Skip loading the %dth instance of program '%s'\n",
980 i, prog->section_name);
981 prog->instances.fds[i] = -1;
987 err = load_program(result.new_insn_ptr,
989 license, kern_version, &fd);
992 pr_warning("Loading the %dth instance of program '%s' failed\n",
993 i, prog->section_name);
999 prog->instances.fds[i] = fd;
1003 pr_warning("failed to load program '%s'\n",
1004 prog->section_name);
1005 zfree(&prog->insns);
1006 prog->insns_cnt = 0;
1011 bpf_object__load_progs(struct bpf_object *obj)
1016 for (i = 0; i < obj->nr_programs; i++) {
1017 err = bpf_program__load(&obj->programs[i],
1026 static int bpf_object__validate(struct bpf_object *obj)
1028 if (obj->kern_version == 0) {
1029 pr_warning("%s doesn't provide kernel version\n",
1031 return -LIBBPF_ERRNO__KVERSION;
1036 static struct bpf_object *
1037 __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz)
1039 struct bpf_object *obj;
1042 if (elf_version(EV_CURRENT) == EV_NONE) {
1043 pr_warning("failed to init libelf for %s\n", path);
1044 return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
1047 obj = bpf_object__new(path, obj_buf, obj_buf_sz);
1051 CHECK_ERR(bpf_object__elf_init(obj), err, out);
1052 CHECK_ERR(bpf_object__check_endianness(obj), err, out);
1053 CHECK_ERR(bpf_object__elf_collect(obj), err, out);
1054 CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
1055 CHECK_ERR(bpf_object__validate(obj), err, out);
1057 bpf_object__elf_finish(obj);
1060 bpf_object__close(obj);
1061 return ERR_PTR(err);
1064 struct bpf_object *bpf_object__open(const char *path)
1066 /* param validation */
1070 pr_debug("loading %s\n", path);
1072 return __bpf_object__open(path, NULL, 0);
1075 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
1081 /* param validation */
1082 if (!obj_buf || obj_buf_sz <= 0)
1086 snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
1087 (unsigned long)obj_buf,
1088 (unsigned long)obj_buf_sz);
1089 tmp_name[sizeof(tmp_name) - 1] = '\0';
1092 pr_debug("loading object '%s' from buffer\n",
1095 return __bpf_object__open(name, obj_buf, obj_buf_sz);
1098 int bpf_object__unload(struct bpf_object *obj)
1105 for (i = 0; i < obj->nr_maps; i++)
1106 zclose(obj->maps[i].fd);
1108 for (i = 0; i < obj->nr_programs; i++)
1109 bpf_program__unload(&obj->programs[i]);
1114 int bpf_object__load(struct bpf_object *obj)
1122 pr_warning("object should not be loaded twice\n");
1128 CHECK_ERR(bpf_object__create_maps(obj), err, out);
1129 CHECK_ERR(bpf_object__relocate(obj), err, out);
1130 CHECK_ERR(bpf_object__load_progs(obj), err, out);
1134 bpf_object__unload(obj);
1135 pr_warning("failed to load object '%s'\n", obj->path);
1139 void bpf_object__close(struct bpf_object *obj)
1146 bpf_object__elf_finish(obj);
1147 bpf_object__unload(obj);
1149 for (i = 0; i < obj->nr_maps; i++) {
1150 zfree(&obj->maps[i].name);
1151 if (obj->maps[i].clear_priv)
1152 obj->maps[i].clear_priv(&obj->maps[i],
1154 obj->maps[i].priv = NULL;
1155 obj->maps[i].clear_priv = NULL;
1160 if (obj->programs && obj->nr_programs) {
1161 for (i = 0; i < obj->nr_programs; i++)
1162 bpf_program__exit(&obj->programs[i]);
1164 zfree(&obj->programs);
1166 list_del(&obj->list);
1171 bpf_object__next(struct bpf_object *prev)
1173 struct bpf_object *next;
1176 next = list_first_entry(&bpf_objects_list,
1180 next = list_next_entry(prev, list);
1182 /* Empty list is noticed here so don't need checking on entry. */
1183 if (&next->list == &bpf_objects_list)
1190 bpf_object__get_name(struct bpf_object *obj)
1193 return ERR_PTR(-EINVAL);
1198 bpf_object__get_kversion(struct bpf_object *obj)
1202 return obj->kern_version;
1205 struct bpf_program *
1206 bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
1214 return &obj->programs[0];
1216 if (prev->obj != obj) {
1217 pr_warning("error: program handler doesn't match object\n");
1221 idx = (prev - obj->programs) + 1;
1222 if (idx >= obj->nr_programs)
1224 return &obj->programs[idx];
1227 int bpf_program__set_private(struct bpf_program *prog,
1229 bpf_program_clear_priv_t clear_priv)
1231 if (prog->priv && prog->clear_priv)
1232 prog->clear_priv(prog, prog->priv);
1235 prog->clear_priv = clear_priv;
1239 int bpf_program__get_private(struct bpf_program *prog, void **ppriv)
1241 *ppriv = prog->priv;
1245 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
1249 title = prog->section_name;
1251 title = strdup(title);
1253 pr_warning("failed to strdup program title\n");
1254 return ERR_PTR(-ENOMEM);
1261 int bpf_program__fd(struct bpf_program *prog)
1263 return bpf_program__nth_fd(prog, 0);
1266 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
1267 bpf_program_prep_t prep)
1271 if (nr_instances <= 0 || !prep)
1274 if (prog->instances.nr > 0 || prog->instances.fds) {
1275 pr_warning("Can't set pre-processor after loading\n");
1279 instances_fds = malloc(sizeof(int) * nr_instances);
1280 if (!instances_fds) {
1281 pr_warning("alloc memory failed for fds\n");
1285 /* fill all fd with -1 */
1286 memset(instances_fds, -1, sizeof(int) * nr_instances);
1288 prog->instances.nr = nr_instances;
1289 prog->instances.fds = instances_fds;
1290 prog->preprocessor = prep;
1294 int bpf_program__nth_fd(struct bpf_program *prog, int n)
1298 if (n >= prog->instances.nr || n < 0) {
1299 pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
1300 n, prog->section_name, prog->instances.nr);
1304 fd = prog->instances.fds[n];
1306 pr_warning("%dth instance of program '%s' is invalid\n",
1307 n, prog->section_name);
1314 int bpf_map__get_fd(struct bpf_map *map)
1322 int bpf_map__get_def(struct bpf_map *map, struct bpf_map_def *pdef)
1331 const char *bpf_map__get_name(struct bpf_map *map)
1338 int bpf_map__set_private(struct bpf_map *map, void *priv,
1339 bpf_map_clear_priv_t clear_priv)
1345 if (map->clear_priv)
1346 map->clear_priv(map, map->priv);
1350 map->clear_priv = clear_priv;
1354 int bpf_map__get_private(struct bpf_map *map, void **ppriv)
1365 bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
1368 struct bpf_map *s, *e;
1370 if (!obj || !obj->maps)
1374 e = obj->maps + obj->nr_maps;
1379 if ((prev < s) || (prev >= e)) {
1380 pr_warning("error in %s: map handler doesn't belong to object\n",
1385 idx = (prev - obj->maps) + 1;
1386 if (idx >= obj->nr_maps)
1388 return &obj->maps[idx];
1392 bpf_object__get_map_by_name(struct bpf_object *obj, const char *name)
1394 struct bpf_map *pos;
1396 bpf_map__for_each(pos, obj) {
1397 if (pos->name && !strcmp(pos->name, name))