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.
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation;
11 * version 2.1 of the License (not later!)
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this program; if not, see <http://www.gnu.org/licenses>
30 #include <asm/unistd.h>
31 #include <linux/kernel.h>
32 #include <linux/bpf.h>
33 #include <linux/list.h>
44 #define __printf(a, b) __attribute__((format(printf, a, b)))
47 static int __base_pr(const char *format, ...)
52 va_start(args, format);
53 err = vfprintf(stderr, format, args);
58 static __printf(1, 2) libbpf_print_fn_t __pr_warning = __base_pr;
59 static __printf(1, 2) libbpf_print_fn_t __pr_info = __base_pr;
60 static __printf(1, 2) libbpf_print_fn_t __pr_debug;
62 #define __pr(func, fmt, ...) \
65 (func)("libbpf: " fmt, ##__VA_ARGS__); \
68 #define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
69 #define pr_info(fmt, ...) __pr(__pr_info, fmt, ##__VA_ARGS__)
70 #define pr_debug(fmt, ...) __pr(__pr_debug, fmt, ##__VA_ARGS__)
72 void libbpf_set_print(libbpf_print_fn_t warn,
73 libbpf_print_fn_t info,
74 libbpf_print_fn_t debug)
81 #define STRERR_BUFSIZE 128
83 #define ERRNO_OFFSET(e) ((e) - __LIBBPF_ERRNO__START)
84 #define ERRCODE_OFFSET(c) ERRNO_OFFSET(LIBBPF_ERRNO__##c)
85 #define NR_ERRNO (__LIBBPF_ERRNO__END - __LIBBPF_ERRNO__START)
87 static const char *libbpf_strerror_table[NR_ERRNO] = {
88 [ERRCODE_OFFSET(LIBELF)] = "Something wrong in libelf",
89 [ERRCODE_OFFSET(FORMAT)] = "BPF object format invalid",
90 [ERRCODE_OFFSET(KVERSION)] = "'version' section incorrect or lost",
91 [ERRCODE_OFFSET(ENDIAN)] = "Endian mismatch",
92 [ERRCODE_OFFSET(INTERNAL)] = "Internal error in libbpf",
93 [ERRCODE_OFFSET(RELOC)] = "Relocation failed",
94 [ERRCODE_OFFSET(VERIFY)] = "Kernel verifier blocks program loading",
95 [ERRCODE_OFFSET(PROG2BIG)] = "Program too big",
96 [ERRCODE_OFFSET(KVER)] = "Incorrect kernel version",
97 [ERRCODE_OFFSET(PROGTYPE)] = "Kernel doesn't support this program type",
100 int libbpf_strerror(int err, char *buf, size_t size)
105 err = err > 0 ? err : -err;
107 if (err < __LIBBPF_ERRNO__START) {
110 ret = strerror_r(err, buf, size);
111 buf[size - 1] = '\0';
115 if (err < __LIBBPF_ERRNO__END) {
118 msg = libbpf_strerror_table[ERRNO_OFFSET(err)];
119 snprintf(buf, size, "%s", msg);
120 buf[size - 1] = '\0';
124 snprintf(buf, size, "Unknown libbpf error %d", err);
125 buf[size - 1] = '\0';
129 #define CHECK_ERR(action, err, out) do { \
136 /* Copied from tools/perf/util/util.h */
138 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
142 # define zclose(fd) ({ \
145 ___err = close((fd)); \
150 #ifdef HAVE_LIBELF_MMAP_SUPPORT
151 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
153 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
157 * bpf_prog should be a better name but it has been used in
161 /* Index in elf obj file, for relocation use. */
164 struct bpf_insn *insns;
166 enum bpf_prog_type type;
178 bpf_program_prep_t preprocessor;
180 struct bpf_object *obj;
182 bpf_program_clear_priv_t clear_priv;
188 struct bpf_map_def def;
190 bpf_map_clear_priv_t clear_priv;
193 static LIST_HEAD(bpf_objects_list);
199 struct bpf_program *programs;
201 struct bpf_map *maps;
207 * Information when doing elf related work. Only valid if fd
226 * All loaded bpf_object is linked in a list, which is
227 * hidden to caller. bpf_objects__<func> handlers deal with
230 struct list_head list;
233 #define obj_elf_valid(o) ((o)->efile.elf)
235 static void bpf_program__unload(struct bpf_program *prog)
243 * If the object is opened but the program was never loaded,
244 * it is possible that prog->instances.nr == -1.
246 if (prog->instances.nr > 0) {
247 for (i = 0; i < prog->instances.nr; i++)
248 zclose(prog->instances.fds[i]);
249 } else if (prog->instances.nr != -1) {
250 pr_warning("Internal error: instances.nr is %d\n",
254 prog->instances.nr = -1;
255 zfree(&prog->instances.fds);
258 static void bpf_program__exit(struct bpf_program *prog)
263 if (prog->clear_priv)
264 prog->clear_priv(prog, prog->priv);
267 prog->clear_priv = NULL;
269 bpf_program__unload(prog);
270 zfree(&prog->section_name);
272 zfree(&prog->reloc_desc);
280 bpf_program__init(void *data, size_t size, char *name, int idx,
281 struct bpf_program *prog)
283 if (size < sizeof(struct bpf_insn)) {
284 pr_warning("corrupted section '%s'\n", name);
288 bzero(prog, sizeof(*prog));
290 prog->section_name = strdup(name);
291 if (!prog->section_name) {
292 pr_warning("failed to alloc name for prog %s\n",
297 prog->insns = malloc(size);
299 pr_warning("failed to alloc insns for %s\n", name);
302 prog->insns_cnt = size / sizeof(struct bpf_insn);
303 memcpy(prog->insns, data,
304 prog->insns_cnt * sizeof(struct bpf_insn));
306 prog->instances.fds = NULL;
307 prog->instances.nr = -1;
308 prog->type = BPF_PROG_TYPE_KPROBE;
312 bpf_program__exit(prog);
317 bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
320 struct bpf_program prog, *progs;
323 err = bpf_program__init(data, size, name, idx, &prog);
327 progs = obj->programs;
328 nr_progs = obj->nr_programs;
330 progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
333 * In this case the original obj->programs
334 * is still valid, so don't need special treat for
335 * bpf_close_object().
337 pr_warning("failed to alloc a new program '%s'\n",
339 bpf_program__exit(&prog);
343 pr_debug("found program %s\n", prog.section_name);
344 obj->programs = progs;
345 obj->nr_programs = nr_progs + 1;
347 progs[nr_progs] = prog;
351 static struct bpf_object *bpf_object__new(const char *path,
355 struct bpf_object *obj;
357 obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
359 pr_warning("alloc memory failed for %s\n", path);
360 return ERR_PTR(-ENOMEM);
363 strcpy(obj->path, path);
367 * Caller of this function should also calls
368 * bpf_object__elf_finish() after data collection to return
369 * obj_buf to user. If not, we should duplicate the buffer to
370 * avoid user freeing them before elf finish.
372 obj->efile.obj_buf = obj_buf;
373 obj->efile.obj_buf_sz = obj_buf_sz;
374 obj->efile.maps_shndx = -1;
378 INIT_LIST_HEAD(&obj->list);
379 list_add(&obj->list, &bpf_objects_list);
383 static void bpf_object__elf_finish(struct bpf_object *obj)
385 if (!obj_elf_valid(obj))
388 if (obj->efile.elf) {
389 elf_end(obj->efile.elf);
390 obj->efile.elf = NULL;
392 obj->efile.symbols = NULL;
394 zfree(&obj->efile.reloc);
395 obj->efile.nr_reloc = 0;
396 zclose(obj->efile.fd);
397 obj->efile.obj_buf = NULL;
398 obj->efile.obj_buf_sz = 0;
401 static int bpf_object__elf_init(struct bpf_object *obj)
406 if (obj_elf_valid(obj)) {
407 pr_warning("elf init: internal error\n");
408 return -LIBBPF_ERRNO__LIBELF;
411 if (obj->efile.obj_buf_sz > 0) {
413 * obj_buf should have been validated by
414 * bpf_object__open_buffer().
416 obj->efile.elf = elf_memory(obj->efile.obj_buf,
417 obj->efile.obj_buf_sz);
419 obj->efile.fd = open(obj->path, O_RDONLY);
420 if (obj->efile.fd < 0) {
421 pr_warning("failed to open %s: %s\n", obj->path,
426 obj->efile.elf = elf_begin(obj->efile.fd,
427 LIBBPF_ELF_C_READ_MMAP,
431 if (!obj->efile.elf) {
432 pr_warning("failed to open %s as ELF file\n",
434 err = -LIBBPF_ERRNO__LIBELF;
438 if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
439 pr_warning("failed to get EHDR from %s\n",
441 err = -LIBBPF_ERRNO__FORMAT;
444 ep = &obj->efile.ehdr;
446 /* Old LLVM set e_machine to EM_NONE */
447 if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != EM_BPF))) {
448 pr_warning("%s is not an eBPF object file\n",
450 err = -LIBBPF_ERRNO__FORMAT;
456 bpf_object__elf_finish(obj);
461 bpf_object__check_endianness(struct bpf_object *obj)
463 static unsigned int const endian = 1;
465 switch (obj->efile.ehdr.e_ident[EI_DATA]) {
467 /* We are big endian, BPF obj is little endian. */
468 if (*(unsigned char const *)&endian != 1)
473 /* We are little endian, BPF obj is big endian. */
474 if (*(unsigned char const *)&endian != 0)
478 return -LIBBPF_ERRNO__ENDIAN;
484 pr_warning("Error: endianness mismatch.\n");
485 return -LIBBPF_ERRNO__ENDIAN;
489 bpf_object__init_license(struct bpf_object *obj,
490 void *data, size_t size)
492 memcpy(obj->license, data,
493 min(size, sizeof(obj->license) - 1));
494 pr_debug("license of %s is %s\n", obj->path, obj->license);
499 bpf_object__init_kversion(struct bpf_object *obj,
500 void *data, size_t size)
504 if (size != sizeof(kver)) {
505 pr_warning("invalid kver section in %s\n", obj->path);
506 return -LIBBPF_ERRNO__FORMAT;
508 memcpy(&kver, data, sizeof(kver));
509 obj->kern_version = kver;
510 pr_debug("kernel version of %s is %x\n", obj->path,
516 bpf_object__init_maps(struct bpf_object *obj, void *data,
522 nr_maps = size / sizeof(struct bpf_map_def);
523 if (!data || !nr_maps) {
524 pr_debug("%s doesn't need map definition\n",
529 pr_debug("maps in %s: %zd bytes\n", obj->path, size);
531 obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
533 pr_warning("alloc maps for object failed\n");
536 obj->nr_maps = nr_maps;
538 for (i = 0; i < nr_maps; i++) {
539 struct bpf_map_def *def = &obj->maps[i].def;
542 * fill all fd with -1 so won't close incorrect
543 * fd (fd=0 is stdin) when failure (zclose won't close
546 obj->maps[i].fd = -1;
548 /* Save map definition into obj->maps */
549 *def = ((struct bpf_map_def *)data)[i];
555 bpf_object__init_maps_name(struct bpf_object *obj)
558 Elf_Data *symbols = obj->efile.symbols;
560 if (!symbols || obj->efile.maps_shndx < 0)
563 for (i = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
566 const char *map_name;
568 if (!gelf_getsym(symbols, i, &sym))
570 if (sym.st_shndx != obj->efile.maps_shndx)
573 map_name = elf_strptr(obj->efile.elf,
574 obj->efile.strtabidx,
576 map_idx = sym.st_value / sizeof(struct bpf_map_def);
577 if (map_idx >= obj->nr_maps) {
578 pr_warning("index of map \"%s\" is buggy: %zu > %zu\n",
579 map_name, map_idx, obj->nr_maps);
582 obj->maps[map_idx].name = strdup(map_name);
583 if (!obj->maps[map_idx].name) {
584 pr_warning("failed to alloc map name\n");
587 pr_debug("map %zu is \"%s\"\n", map_idx,
588 obj->maps[map_idx].name);
593 static bool section_have_execinstr(struct bpf_object *obj, int idx)
598 scn = elf_getscn(obj->efile.elf, idx);
602 if (gelf_getshdr(scn, &sh) != &sh)
605 if (sh.sh_flags & SHF_EXECINSTR)
611 static int bpf_object__elf_collect(struct bpf_object *obj)
613 Elf *elf = obj->efile.elf;
614 GElf_Ehdr *ep = &obj->efile.ehdr;
616 int idx = 0, err = 0;
618 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
619 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
620 pr_warning("failed to get e_shstrndx from %s\n",
622 return -LIBBPF_ERRNO__FORMAT;
625 while ((scn = elf_nextscn(elf, scn)) != NULL) {
631 if (gelf_getshdr(scn, &sh) != &sh) {
632 pr_warning("failed to get section header from %s\n",
634 err = -LIBBPF_ERRNO__FORMAT;
638 name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
640 pr_warning("failed to get section name from %s\n",
642 err = -LIBBPF_ERRNO__FORMAT;
646 data = elf_getdata(scn, 0);
648 pr_warning("failed to get section data from %s(%s)\n",
650 err = -LIBBPF_ERRNO__FORMAT;
653 pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n",
654 name, (unsigned long)data->d_size,
655 (int)sh.sh_link, (unsigned long)sh.sh_flags,
658 if (strcmp(name, "license") == 0)
659 err = bpf_object__init_license(obj,
662 else if (strcmp(name, "version") == 0)
663 err = bpf_object__init_kversion(obj,
666 else if (strcmp(name, "maps") == 0) {
667 err = bpf_object__init_maps(obj, data->d_buf,
669 obj->efile.maps_shndx = idx;
670 } else if (sh.sh_type == SHT_SYMTAB) {
671 if (obj->efile.symbols) {
672 pr_warning("bpf: multiple SYMTAB in %s\n",
674 err = -LIBBPF_ERRNO__FORMAT;
676 obj->efile.symbols = data;
677 obj->efile.strtabidx = sh.sh_link;
679 } else if ((sh.sh_type == SHT_PROGBITS) &&
680 (sh.sh_flags & SHF_EXECINSTR) &&
681 (data->d_size > 0)) {
682 err = bpf_object__add_program(obj, data->d_buf,
683 data->d_size, name, idx);
685 char errmsg[STRERR_BUFSIZE];
687 strerror_r(-err, errmsg, sizeof(errmsg));
688 pr_warning("failed to alloc program %s (%s): %s",
689 name, obj->path, errmsg);
691 } else if (sh.sh_type == SHT_REL) {
692 void *reloc = obj->efile.reloc;
693 int nr_reloc = obj->efile.nr_reloc + 1;
694 int sec = sh.sh_info; /* points to other section */
696 /* Only do relo for section with exec instructions */
697 if (!section_have_execinstr(obj, sec)) {
698 pr_debug("skip relo %s(%d) for section(%d)\n",
703 reloc = realloc(reloc,
704 sizeof(*obj->efile.reloc) * nr_reloc);
706 pr_warning("realloc failed\n");
709 int n = nr_reloc - 1;
711 obj->efile.reloc = reloc;
712 obj->efile.nr_reloc = nr_reloc;
714 obj->efile.reloc[n].shdr = sh;
715 obj->efile.reloc[n].data = data;
722 if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) {
723 pr_warning("Corrupted ELF file: index of strtab invalid\n");
724 return LIBBPF_ERRNO__FORMAT;
726 if (obj->efile.maps_shndx >= 0)
727 err = bpf_object__init_maps_name(obj);
732 static struct bpf_program *
733 bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
735 struct bpf_program *prog;
738 for (i = 0; i < obj->nr_programs; i++) {
739 prog = &obj->programs[i];
740 if (prog->idx == idx)
747 bpf_program__collect_reloc(struct bpf_program *prog,
748 size_t nr_maps, GElf_Shdr *shdr,
749 Elf_Data *data, Elf_Data *symbols,
754 pr_debug("collecting relocating info for: '%s'\n",
756 nrels = shdr->sh_size / shdr->sh_entsize;
758 prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
759 if (!prog->reloc_desc) {
760 pr_warning("failed to alloc memory in relocation\n");
763 prog->nr_reloc = nrels;
765 for (i = 0; i < nrels; i++) {
768 unsigned int insn_idx;
769 struct bpf_insn *insns = prog->insns;
772 if (!gelf_getrel(data, i, &rel)) {
773 pr_warning("relocation: failed to get %d reloc\n", i);
774 return -LIBBPF_ERRNO__FORMAT;
777 if (!gelf_getsym(symbols,
778 GELF_R_SYM(rel.r_info),
780 pr_warning("relocation: symbol %"PRIx64" not found\n",
781 GELF_R_SYM(rel.r_info));
782 return -LIBBPF_ERRNO__FORMAT;
785 if (sym.st_shndx != maps_shndx) {
786 pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n",
787 prog->section_name, sym.st_shndx);
788 return -LIBBPF_ERRNO__RELOC;
791 insn_idx = rel.r_offset / sizeof(struct bpf_insn);
792 pr_debug("relocation: insn_idx=%u\n", insn_idx);
794 if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
795 pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
796 insn_idx, insns[insn_idx].code);
797 return -LIBBPF_ERRNO__RELOC;
800 map_idx = sym.st_value / sizeof(struct bpf_map_def);
801 if (map_idx >= nr_maps) {
802 pr_warning("bpf relocation: map_idx %d large than %d\n",
803 (int)map_idx, (int)nr_maps - 1);
804 return -LIBBPF_ERRNO__RELOC;
807 prog->reloc_desc[i].insn_idx = insn_idx;
808 prog->reloc_desc[i].map_idx = map_idx;
814 bpf_object__create_maps(struct bpf_object *obj)
818 for (i = 0; i < obj->nr_maps; i++) {
819 struct bpf_map_def *def = &obj->maps[i].def;
820 int *pfd = &obj->maps[i].fd;
822 *pfd = bpf_create_map(def->type,
830 pr_warning("failed to create map: %s\n",
832 for (j = 0; j < i; j++)
833 zclose(obj->maps[j].fd);
836 pr_debug("create map: fd=%d\n", *pfd);
843 bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
847 if (!prog || !prog->reloc_desc)
850 for (i = 0; i < prog->nr_reloc; i++) {
851 int insn_idx, map_idx;
852 struct bpf_insn *insns = prog->insns;
854 insn_idx = prog->reloc_desc[i].insn_idx;
855 map_idx = prog->reloc_desc[i].map_idx;
857 if (insn_idx >= (int)prog->insns_cnt) {
858 pr_warning("relocation out of range: '%s'\n",
860 return -LIBBPF_ERRNO__RELOC;
862 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
863 insns[insn_idx].imm = obj->maps[map_idx].fd;
866 zfree(&prog->reloc_desc);
873 bpf_object__relocate(struct bpf_object *obj)
875 struct bpf_program *prog;
879 for (i = 0; i < obj->nr_programs; i++) {
880 prog = &obj->programs[i];
882 err = bpf_program__relocate(prog, obj);
884 pr_warning("failed to relocate '%s'\n",
892 static int bpf_object__collect_reloc(struct bpf_object *obj)
896 if (!obj_elf_valid(obj)) {
897 pr_warning("Internal error: elf object is closed\n");
898 return -LIBBPF_ERRNO__INTERNAL;
901 for (i = 0; i < obj->efile.nr_reloc; i++) {
902 GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
903 Elf_Data *data = obj->efile.reloc[i].data;
904 int idx = shdr->sh_info;
905 struct bpf_program *prog;
906 size_t nr_maps = obj->nr_maps;
908 if (shdr->sh_type != SHT_REL) {
909 pr_warning("internal error at %d\n", __LINE__);
910 return -LIBBPF_ERRNO__INTERNAL;
913 prog = bpf_object__find_prog_by_idx(obj, idx);
915 pr_warning("relocation failed: no %d section\n",
917 return -LIBBPF_ERRNO__RELOC;
920 err = bpf_program__collect_reloc(prog, nr_maps,
923 obj->efile.maps_shndx);
931 load_program(enum bpf_prog_type type, struct bpf_insn *insns,
932 int insns_cnt, char *license, u32 kern_version, int *pfd)
937 if (!insns || !insns_cnt)
940 log_buf = malloc(BPF_LOG_BUF_SIZE);
942 pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
944 ret = bpf_load_program(type, insns, insns_cnt, license,
945 kern_version, log_buf, BPF_LOG_BUF_SIZE);
953 ret = -LIBBPF_ERRNO__LOAD;
954 pr_warning("load bpf program failed: %s\n", strerror(errno));
956 if (log_buf && log_buf[0] != '\0') {
957 ret = -LIBBPF_ERRNO__VERIFY;
958 pr_warning("-- BEGIN DUMP LOG ---\n");
959 pr_warning("\n%s\n", log_buf);
960 pr_warning("-- END LOG --\n");
961 } else if (insns_cnt >= BPF_MAXINSNS) {
962 pr_warning("Program too large (%d insns), at most %d insns\n",
963 insns_cnt, BPF_MAXINSNS);
964 ret = -LIBBPF_ERRNO__PROG2BIG;
966 /* Wrong program type? */
967 if (type != BPF_PROG_TYPE_KPROBE) {
970 fd = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
971 insns_cnt, license, kern_version,
975 ret = -LIBBPF_ERRNO__PROGTYPE;
981 ret = -LIBBPF_ERRNO__KVER;
990 bpf_program__load(struct bpf_program *prog,
991 char *license, u32 kern_version)
995 if (prog->instances.nr < 0 || !prog->instances.fds) {
996 if (prog->preprocessor) {
997 pr_warning("Internal error: can't load program '%s'\n",
999 return -LIBBPF_ERRNO__INTERNAL;
1002 prog->instances.fds = malloc(sizeof(int));
1003 if (!prog->instances.fds) {
1004 pr_warning("Not enough memory for BPF fds\n");
1007 prog->instances.nr = 1;
1008 prog->instances.fds[0] = -1;
1011 if (!prog->preprocessor) {
1012 if (prog->instances.nr != 1) {
1013 pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
1014 prog->section_name, prog->instances.nr);
1016 err = load_program(prog->type, prog->insns, prog->insns_cnt,
1017 license, kern_version, &fd);
1019 prog->instances.fds[0] = fd;
1023 for (i = 0; i < prog->instances.nr; i++) {
1024 struct bpf_prog_prep_result result;
1025 bpf_program_prep_t preprocessor = prog->preprocessor;
1027 bzero(&result, sizeof(result));
1028 err = preprocessor(prog, i, prog->insns,
1029 prog->insns_cnt, &result);
1031 pr_warning("Preprocessing the %dth instance of program '%s' failed\n",
1032 i, prog->section_name);
1036 if (!result.new_insn_ptr || !result.new_insn_cnt) {
1037 pr_debug("Skip loading the %dth instance of program '%s'\n",
1038 i, prog->section_name);
1039 prog->instances.fds[i] = -1;
1045 err = load_program(prog->type, result.new_insn_ptr,
1046 result.new_insn_cnt,
1047 license, kern_version, &fd);
1050 pr_warning("Loading the %dth instance of program '%s' failed\n",
1051 i, prog->section_name);
1057 prog->instances.fds[i] = fd;
1061 pr_warning("failed to load program '%s'\n",
1062 prog->section_name);
1063 zfree(&prog->insns);
1064 prog->insns_cnt = 0;
1069 bpf_object__load_progs(struct bpf_object *obj)
1074 for (i = 0; i < obj->nr_programs; i++) {
1075 err = bpf_program__load(&obj->programs[i],
1084 static int bpf_object__validate(struct bpf_object *obj)
1086 if (obj->kern_version == 0) {
1087 pr_warning("%s doesn't provide kernel version\n",
1089 return -LIBBPF_ERRNO__KVERSION;
1094 static struct bpf_object *
1095 __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz)
1097 struct bpf_object *obj;
1100 if (elf_version(EV_CURRENT) == EV_NONE) {
1101 pr_warning("failed to init libelf for %s\n", path);
1102 return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
1105 obj = bpf_object__new(path, obj_buf, obj_buf_sz);
1109 CHECK_ERR(bpf_object__elf_init(obj), err, out);
1110 CHECK_ERR(bpf_object__check_endianness(obj), err, out);
1111 CHECK_ERR(bpf_object__elf_collect(obj), err, out);
1112 CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
1113 CHECK_ERR(bpf_object__validate(obj), err, out);
1115 bpf_object__elf_finish(obj);
1118 bpf_object__close(obj);
1119 return ERR_PTR(err);
1122 struct bpf_object *bpf_object__open(const char *path)
1124 /* param validation */
1128 pr_debug("loading %s\n", path);
1130 return __bpf_object__open(path, NULL, 0);
1133 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
1139 /* param validation */
1140 if (!obj_buf || obj_buf_sz <= 0)
1144 snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
1145 (unsigned long)obj_buf,
1146 (unsigned long)obj_buf_sz);
1147 tmp_name[sizeof(tmp_name) - 1] = '\0';
1150 pr_debug("loading object '%s' from buffer\n",
1153 return __bpf_object__open(name, obj_buf, obj_buf_sz);
1156 int bpf_object__unload(struct bpf_object *obj)
1163 for (i = 0; i < obj->nr_maps; i++)
1164 zclose(obj->maps[i].fd);
1166 for (i = 0; i < obj->nr_programs; i++)
1167 bpf_program__unload(&obj->programs[i]);
1172 int bpf_object__load(struct bpf_object *obj)
1180 pr_warning("object should not be loaded twice\n");
1186 CHECK_ERR(bpf_object__create_maps(obj), err, out);
1187 CHECK_ERR(bpf_object__relocate(obj), err, out);
1188 CHECK_ERR(bpf_object__load_progs(obj), err, out);
1192 bpf_object__unload(obj);
1193 pr_warning("failed to load object '%s'\n", obj->path);
1197 void bpf_object__close(struct bpf_object *obj)
1204 bpf_object__elf_finish(obj);
1205 bpf_object__unload(obj);
1207 for (i = 0; i < obj->nr_maps; i++) {
1208 zfree(&obj->maps[i].name);
1209 if (obj->maps[i].clear_priv)
1210 obj->maps[i].clear_priv(&obj->maps[i],
1212 obj->maps[i].priv = NULL;
1213 obj->maps[i].clear_priv = NULL;
1218 if (obj->programs && obj->nr_programs) {
1219 for (i = 0; i < obj->nr_programs; i++)
1220 bpf_program__exit(&obj->programs[i]);
1222 zfree(&obj->programs);
1224 list_del(&obj->list);
1229 bpf_object__next(struct bpf_object *prev)
1231 struct bpf_object *next;
1234 next = list_first_entry(&bpf_objects_list,
1238 next = list_next_entry(prev, list);
1240 /* Empty list is noticed here so don't need checking on entry. */
1241 if (&next->list == &bpf_objects_list)
1247 const char *bpf_object__name(struct bpf_object *obj)
1249 return obj ? obj->path : ERR_PTR(-EINVAL);
1252 unsigned int bpf_object__kversion(struct bpf_object *obj)
1254 return obj ? obj->kern_version : 0;
1257 struct bpf_program *
1258 bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
1266 return &obj->programs[0];
1268 if (prev->obj != obj) {
1269 pr_warning("error: program handler doesn't match object\n");
1273 idx = (prev - obj->programs) + 1;
1274 if (idx >= obj->nr_programs)
1276 return &obj->programs[idx];
1279 int bpf_program__set_priv(struct bpf_program *prog, void *priv,
1280 bpf_program_clear_priv_t clear_priv)
1282 if (prog->priv && prog->clear_priv)
1283 prog->clear_priv(prog, prog->priv);
1286 prog->clear_priv = clear_priv;
1290 void *bpf_program__priv(struct bpf_program *prog)
1292 return prog ? prog->priv : ERR_PTR(-EINVAL);
1295 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
1299 title = prog->section_name;
1301 title = strdup(title);
1303 pr_warning("failed to strdup program title\n");
1304 return ERR_PTR(-ENOMEM);
1311 int bpf_program__fd(struct bpf_program *prog)
1313 return bpf_program__nth_fd(prog, 0);
1316 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
1317 bpf_program_prep_t prep)
1321 if (nr_instances <= 0 || !prep)
1324 if (prog->instances.nr > 0 || prog->instances.fds) {
1325 pr_warning("Can't set pre-processor after loading\n");
1329 instances_fds = malloc(sizeof(int) * nr_instances);
1330 if (!instances_fds) {
1331 pr_warning("alloc memory failed for fds\n");
1335 /* fill all fd with -1 */
1336 memset(instances_fds, -1, sizeof(int) * nr_instances);
1338 prog->instances.nr = nr_instances;
1339 prog->instances.fds = instances_fds;
1340 prog->preprocessor = prep;
1344 int bpf_program__nth_fd(struct bpf_program *prog, int n)
1348 if (n >= prog->instances.nr || n < 0) {
1349 pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
1350 n, prog->section_name, prog->instances.nr);
1354 fd = prog->instances.fds[n];
1356 pr_warning("%dth instance of program '%s' is invalid\n",
1357 n, prog->section_name);
1364 static void bpf_program__set_type(struct bpf_program *prog,
1365 enum bpf_prog_type type)
1370 int bpf_program__set_tracepoint(struct bpf_program *prog)
1374 bpf_program__set_type(prog, BPF_PROG_TYPE_TRACEPOINT);
1378 int bpf_program__set_kprobe(struct bpf_program *prog)
1382 bpf_program__set_type(prog, BPF_PROG_TYPE_KPROBE);
1386 static bool bpf_program__is_type(struct bpf_program *prog,
1387 enum bpf_prog_type type)
1389 return prog ? (prog->type == type) : false;
1392 bool bpf_program__is_tracepoint(struct bpf_program *prog)
1394 return bpf_program__is_type(prog, BPF_PROG_TYPE_TRACEPOINT);
1397 bool bpf_program__is_kprobe(struct bpf_program *prog)
1399 return bpf_program__is_type(prog, BPF_PROG_TYPE_KPROBE);
1402 int bpf_map__fd(struct bpf_map *map)
1404 return map ? map->fd : -EINVAL;
1407 const struct bpf_map_def *bpf_map__def(struct bpf_map *map)
1409 return map ? &map->def : ERR_PTR(-EINVAL);
1412 const char *bpf_map__name(struct bpf_map *map)
1414 return map ? map->name : NULL;
1417 int bpf_map__set_priv(struct bpf_map *map, void *priv,
1418 bpf_map_clear_priv_t clear_priv)
1424 if (map->clear_priv)
1425 map->clear_priv(map, map->priv);
1429 map->clear_priv = clear_priv;
1433 void *bpf_map__priv(struct bpf_map *map)
1435 return map ? map->priv : ERR_PTR(-EINVAL);
1439 bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
1442 struct bpf_map *s, *e;
1444 if (!obj || !obj->maps)
1448 e = obj->maps + obj->nr_maps;
1453 if ((prev < s) || (prev >= e)) {
1454 pr_warning("error in %s: map handler doesn't belong to object\n",
1459 idx = (prev - obj->maps) + 1;
1460 if (idx >= obj->nr_maps)
1462 return &obj->maps[idx];
1466 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name)
1468 struct bpf_map *pos;
1470 bpf_map__for_each(pos, obj) {
1471 if (pos->name && !strcmp(pos->name, name))