1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
4 * Common eBPF ELF object loading operations.
6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
8 * Copyright (C) 2015 Huawei Inc.
9 * Copyright (C) 2017 Nicira, Inc.
10 * Copyright (C) 2019 Isovalent, Inc.
28 #include <asm/unistd.h>
29 #include <linux/err.h>
30 #include <linux/kernel.h>
31 #include <linux/bpf.h>
32 #include <linux/btf.h>
33 #include <linux/filter.h>
34 #include <linux/list.h>
35 #include <linux/limits.h>
36 #include <linux/perf_event.h>
37 #include <linux/ring_buffer.h>
38 #include <linux/version.h>
39 #include <sys/epoll.h>
40 #include <sys/ioctl.h>
43 #include <sys/types.h>
45 #include <sys/utsname.h>
46 #include <sys/resource.h>
47 #include <tools/libc_compat.h>
55 #include "str_error.h"
56 #include "libbpf_internal.h"
59 /* make sure libbpf doesn't use kernel-only integer typedefs */
60 #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
67 #define BPF_FS_MAGIC 0xcafe4a11
70 /* vsprintf() in __base_pr() uses nonliteral format string. It may break
71 * compilation if user enables corresponding warning. Disable it explicitly.
73 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
75 #define __printf(a, b) __attribute__((format(printf, a, b)))
77 static struct bpf_map *bpf_object__add_map(struct bpf_object *obj);
78 static struct bpf_program *bpf_object__find_prog_by_idx(struct bpf_object *obj,
80 static const struct btf_type *
81 skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id);
83 static int __base_pr(enum libbpf_print_level level, const char *format,
86 if (level == LIBBPF_DEBUG)
89 return vfprintf(stderr, format, args);
92 static libbpf_print_fn_t __libbpf_pr = __base_pr;
94 libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn)
96 libbpf_print_fn_t old_print_fn = __libbpf_pr;
103 void libbpf_print(enum libbpf_print_level level, const char *format, ...)
110 va_start(args, format);
111 __libbpf_pr(level, format, args);
115 static void pr_perm_msg(int err)
120 if (err != -EPERM || geteuid() != 0)
123 err = getrlimit(RLIMIT_MEMLOCK, &limit);
127 if (limit.rlim_cur == RLIM_INFINITY)
130 if (limit.rlim_cur < 1024)
131 snprintf(buf, sizeof(buf), "%zu bytes", (size_t)limit.rlim_cur);
132 else if (limit.rlim_cur < 1024*1024)
133 snprintf(buf, sizeof(buf), "%.1f KiB", (double)limit.rlim_cur / 1024);
135 snprintf(buf, sizeof(buf), "%.1f MiB", (double)limit.rlim_cur / (1024*1024));
137 pr_warn("permission error while running as root; try raising 'ulimit -l'? current value: %s\n",
141 #define STRERR_BUFSIZE 128
143 /* Copied from tools/perf/util/util.h */
145 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
149 # define zclose(fd) ({ \
152 ___err = close((fd)); \
157 #ifdef HAVE_LIBELF_MMAP_SUPPORT
158 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
160 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
163 static inline __u64 ptr_to_u64(const void *ptr)
165 return (__u64) (unsigned long) ptr;
168 struct bpf_capabilities {
169 /* v4.14: kernel support for program & map names. */
171 /* v5.2: kernel support for global data sections. */
173 /* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */
175 /* BTF_KIND_VAR and BTF_KIND_DATASEC support */
177 /* BPF_F_MMAPABLE is supported for arrays */
179 /* BTF_FUNC_GLOBAL is supported */
180 __u32 btf_func_global:1;
191 enum reloc_type type;
198 * bpf_prog should be a better name but it has been used in
202 /* Index in elf obj file, for relocation use. */
207 /* section_name with / replaced by _; makes recursive pinning
208 * in bpf_object__pin_programs easier
211 struct bpf_insn *insns;
212 size_t insns_cnt, main_prog_cnt;
213 enum bpf_prog_type type;
215 struct reloc_desc *reloc_desc;
223 bpf_program_prep_t preprocessor;
225 struct bpf_object *obj;
227 bpf_program_clear_priv_t clear_priv;
229 enum bpf_attach_type expected_attach_type;
231 __u32 attach_prog_fd;
233 __u32 func_info_rec_size;
236 struct bpf_capabilities *caps;
239 __u32 line_info_rec_size;
244 struct bpf_struct_ops {
246 const struct btf_type *type;
247 struct bpf_program **progs;
248 __u32 *kern_func_off;
249 /* e.g. struct tcp_congestion_ops in bpf_prog's btf format */
251 /* e.g. struct bpf_struct_ops_tcp_congestion_ops in
252 * btf_vmlinux's format.
253 * struct bpf_struct_ops_tcp_congestion_ops {
254 * [... some other kernel fields ...]
255 * struct tcp_congestion_ops data;
257 * kern_vdata-size == sizeof(struct bpf_struct_ops_tcp_congestion_ops)
258 * bpf_map__init_kern_struct_ops() will populate the "kern_vdata"
265 #define DATA_SEC ".data"
266 #define BSS_SEC ".bss"
267 #define RODATA_SEC ".rodata"
268 #define KCONFIG_SEC ".kconfig"
269 #define STRUCT_OPS_SEC ".struct_ops"
271 enum libbpf_map_type {
279 static const char * const libbpf_type_to_btf_name[] = {
280 [LIBBPF_MAP_DATA] = DATA_SEC,
281 [LIBBPF_MAP_BSS] = BSS_SEC,
282 [LIBBPF_MAP_RODATA] = RODATA_SEC,
283 [LIBBPF_MAP_KCONFIG] = KCONFIG_SEC,
293 struct bpf_map_def def;
294 __u32 btf_key_type_id;
295 __u32 btf_value_type_id;
296 __u32 btf_vmlinux_value_type_id;
298 bpf_map_clear_priv_t clear_priv;
299 enum libbpf_map_type libbpf_type;
301 struct bpf_struct_ops *st_ops;
320 enum extern_type type;
329 static LIST_HEAD(bpf_objects_list);
332 char name[BPF_OBJ_NAME_LEN];
336 struct bpf_program *programs;
338 struct bpf_map *maps;
343 struct extern_desc *externs;
348 bool has_pseudo_calls;
351 * Information when doing elf related work. Only valid if fd
364 Elf_Data *st_ops_data;
381 * All loaded bpf_object is linked in a list, which is
382 * hidden to caller. bpf_objects__<func> handlers deal with
385 struct list_head list;
388 /* Parse and load BTF vmlinux if any of the programs in the object need
391 struct btf *btf_vmlinux;
392 struct btf_ext *btf_ext;
395 bpf_object_clear_priv_t clear_priv;
397 struct bpf_capabilities caps;
401 #define obj_elf_valid(o) ((o)->efile.elf)
403 void bpf_program__unload(struct bpf_program *prog)
411 * If the object is opened but the program was never loaded,
412 * it is possible that prog->instances.nr == -1.
414 if (prog->instances.nr > 0) {
415 for (i = 0; i < prog->instances.nr; i++)
416 zclose(prog->instances.fds[i]);
417 } else if (prog->instances.nr != -1) {
418 pr_warn("Internal error: instances.nr is %d\n",
422 prog->instances.nr = -1;
423 zfree(&prog->instances.fds);
425 zfree(&prog->func_info);
426 zfree(&prog->line_info);
429 static void bpf_program__exit(struct bpf_program *prog)
434 if (prog->clear_priv)
435 prog->clear_priv(prog, prog->priv);
438 prog->clear_priv = NULL;
440 bpf_program__unload(prog);
442 zfree(&prog->section_name);
443 zfree(&prog->pin_name);
445 zfree(&prog->reloc_desc);
452 static char *__bpf_program__pin_name(struct bpf_program *prog)
456 name = p = strdup(prog->section_name);
457 while ((p = strchr(p, '/')))
464 bpf_program__init(void *data, size_t size, char *section_name, int idx,
465 struct bpf_program *prog)
467 const size_t bpf_insn_sz = sizeof(struct bpf_insn);
469 if (size == 0 || size % bpf_insn_sz) {
470 pr_warn("corrupted section '%s', size: %zu\n",
475 memset(prog, 0, sizeof(*prog));
477 prog->section_name = strdup(section_name);
478 if (!prog->section_name) {
479 pr_warn("failed to alloc name for prog under section(%d) %s\n",
484 prog->pin_name = __bpf_program__pin_name(prog);
485 if (!prog->pin_name) {
486 pr_warn("failed to alloc pin name for prog under section(%d) %s\n",
491 prog->insns = malloc(size);
493 pr_warn("failed to alloc insns for prog under section %s\n",
497 prog->insns_cnt = size / bpf_insn_sz;
498 memcpy(prog->insns, data, size);
500 prog->instances.fds = NULL;
501 prog->instances.nr = -1;
502 prog->type = BPF_PROG_TYPE_UNSPEC;
506 bpf_program__exit(prog);
511 bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
512 char *section_name, int idx)
514 struct bpf_program prog, *progs;
517 err = bpf_program__init(data, size, section_name, idx, &prog);
521 prog.caps = &obj->caps;
522 progs = obj->programs;
523 nr_progs = obj->nr_programs;
525 progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
528 * In this case the original obj->programs
529 * is still valid, so don't need special treat for
530 * bpf_close_object().
532 pr_warn("failed to alloc a new program under section '%s'\n",
534 bpf_program__exit(&prog);
538 pr_debug("found program %s\n", prog.section_name);
539 obj->programs = progs;
540 obj->nr_programs = nr_progs + 1;
542 progs[nr_progs] = prog;
547 bpf_object__init_prog_names(struct bpf_object *obj)
549 Elf_Data *symbols = obj->efile.symbols;
550 struct bpf_program *prog;
553 for (pi = 0; pi < obj->nr_programs; pi++) {
554 const char *name = NULL;
556 prog = &obj->programs[pi];
558 for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name;
562 if (!gelf_getsym(symbols, si, &sym))
564 if (sym.st_shndx != prog->idx)
566 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL)
569 name = elf_strptr(obj->efile.elf,
570 obj->efile.strtabidx,
573 pr_warn("failed to get sym name string for prog %s\n",
575 return -LIBBPF_ERRNO__LIBELF;
579 if (!name && prog->idx == obj->efile.text_shndx)
583 pr_warn("failed to find sym for prog %s\n",
588 prog->name = strdup(name);
590 pr_warn("failed to allocate memory for prog sym %s\n",
599 static __u32 get_kernel_version(void)
601 __u32 major, minor, patch;
605 if (sscanf(info.release, "%u.%u.%u", &major, &minor, &patch) != 3)
607 return KERNEL_VERSION(major, minor, patch);
610 static const struct btf_member *
611 find_member_by_offset(const struct btf_type *t, __u32 bit_offset)
613 struct btf_member *m;
616 for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {
617 if (btf_member_bit_offset(t, i) == bit_offset)
624 static const struct btf_member *
625 find_member_by_name(const struct btf *btf, const struct btf_type *t,
628 struct btf_member *m;
631 for (i = 0, m = btf_members(t); i < btf_vlen(t); i++, m++) {
632 if (!strcmp(btf__name_by_offset(btf, m->name_off), name))
639 #define STRUCT_OPS_VALUE_PREFIX "bpf_struct_ops_"
640 static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix,
641 const char *name, __u32 kind);
644 find_struct_ops_kern_types(const struct btf *btf, const char *tname,
645 const struct btf_type **type, __u32 *type_id,
646 const struct btf_type **vtype, __u32 *vtype_id,
647 const struct btf_member **data_member)
649 const struct btf_type *kern_type, *kern_vtype;
650 const struct btf_member *kern_data_member;
651 __s32 kern_vtype_id, kern_type_id;
654 kern_type_id = btf__find_by_name_kind(btf, tname, BTF_KIND_STRUCT);
655 if (kern_type_id < 0) {
656 pr_warn("struct_ops init_kern: struct %s is not found in kernel BTF\n",
660 kern_type = btf__type_by_id(btf, kern_type_id);
662 /* Find the corresponding "map_value" type that will be used
663 * in map_update(BPF_MAP_TYPE_STRUCT_OPS). For example,
664 * find "struct bpf_struct_ops_tcp_congestion_ops" from the
667 kern_vtype_id = find_btf_by_prefix_kind(btf, STRUCT_OPS_VALUE_PREFIX,
668 tname, BTF_KIND_STRUCT);
669 if (kern_vtype_id < 0) {
670 pr_warn("struct_ops init_kern: struct %s%s is not found in kernel BTF\n",
671 STRUCT_OPS_VALUE_PREFIX, tname);
672 return kern_vtype_id;
674 kern_vtype = btf__type_by_id(btf, kern_vtype_id);
676 /* Find "struct tcp_congestion_ops" from
677 * struct bpf_struct_ops_tcp_congestion_ops {
679 * struct tcp_congestion_ops data;
682 kern_data_member = btf_members(kern_vtype);
683 for (i = 0; i < btf_vlen(kern_vtype); i++, kern_data_member++) {
684 if (kern_data_member->type == kern_type_id)
687 if (i == btf_vlen(kern_vtype)) {
688 pr_warn("struct_ops init_kern: struct %s data is not found in struct %s%s\n",
689 tname, STRUCT_OPS_VALUE_PREFIX, tname);
694 *type_id = kern_type_id;
696 *vtype_id = kern_vtype_id;
697 *data_member = kern_data_member;
702 static bool bpf_map__is_struct_ops(const struct bpf_map *map)
704 return map->def.type == BPF_MAP_TYPE_STRUCT_OPS;
707 /* Init the map's fields that depend on kern_btf */
708 static int bpf_map__init_kern_struct_ops(struct bpf_map *map,
709 const struct btf *btf,
710 const struct btf *kern_btf)
712 const struct btf_member *member, *kern_member, *kern_data_member;
713 const struct btf_type *type, *kern_type, *kern_vtype;
714 __u32 i, kern_type_id, kern_vtype_id, kern_data_off;
715 struct bpf_struct_ops *st_ops;
716 void *data, *kern_data;
720 st_ops = map->st_ops;
722 tname = st_ops->tname;
723 err = find_struct_ops_kern_types(kern_btf, tname,
724 &kern_type, &kern_type_id,
725 &kern_vtype, &kern_vtype_id,
730 pr_debug("struct_ops init_kern %s: type_id:%u kern_type_id:%u kern_vtype_id:%u\n",
731 map->name, st_ops->type_id, kern_type_id, kern_vtype_id);
733 map->def.value_size = kern_vtype->size;
734 map->btf_vmlinux_value_type_id = kern_vtype_id;
736 st_ops->kern_vdata = calloc(1, kern_vtype->size);
737 if (!st_ops->kern_vdata)
741 kern_data_off = kern_data_member->offset / 8;
742 kern_data = st_ops->kern_vdata + kern_data_off;
744 member = btf_members(type);
745 for (i = 0; i < btf_vlen(type); i++, member++) {
746 const struct btf_type *mtype, *kern_mtype;
747 __u32 mtype_id, kern_mtype_id;
748 void *mdata, *kern_mdata;
749 __s64 msize, kern_msize;
750 __u32 moff, kern_moff;
751 __u32 kern_member_idx;
754 mname = btf__name_by_offset(btf, member->name_off);
755 kern_member = find_member_by_name(kern_btf, kern_type, mname);
757 pr_warn("struct_ops init_kern %s: Cannot find member %s in kernel BTF\n",
762 kern_member_idx = kern_member - btf_members(kern_type);
763 if (btf_member_bitfield_size(type, i) ||
764 btf_member_bitfield_size(kern_type, kern_member_idx)) {
765 pr_warn("struct_ops init_kern %s: bitfield %s is not supported\n",
770 moff = member->offset / 8;
771 kern_moff = kern_member->offset / 8;
774 kern_mdata = kern_data + kern_moff;
776 mtype = skip_mods_and_typedefs(btf, member->type, &mtype_id);
777 kern_mtype = skip_mods_and_typedefs(kern_btf, kern_member->type,
779 if (BTF_INFO_KIND(mtype->info) !=
780 BTF_INFO_KIND(kern_mtype->info)) {
781 pr_warn("struct_ops init_kern %s: Unmatched member type %s %u != %u(kernel)\n",
782 map->name, mname, BTF_INFO_KIND(mtype->info),
783 BTF_INFO_KIND(kern_mtype->info));
787 if (btf_is_ptr(mtype)) {
788 struct bpf_program *prog;
790 mtype = skip_mods_and_typedefs(btf, mtype->type, &mtype_id);
791 kern_mtype = skip_mods_and_typedefs(kern_btf,
794 if (!btf_is_func_proto(mtype) ||
795 !btf_is_func_proto(kern_mtype)) {
796 pr_warn("struct_ops init_kern %s: non func ptr %s is not supported\n",
801 prog = st_ops->progs[i];
803 pr_debug("struct_ops init_kern %s: func ptr %s is not set\n",
808 prog->attach_btf_id = kern_type_id;
809 prog->expected_attach_type = kern_member_idx;
811 st_ops->kern_func_off[i] = kern_data_off + kern_moff;
813 pr_debug("struct_ops init_kern %s: func ptr %s is set to prog %s from data(+%u) to kern_data(+%u)\n",
814 map->name, mname, prog->name, moff,
820 msize = btf__resolve_size(btf, mtype_id);
821 kern_msize = btf__resolve_size(kern_btf, kern_mtype_id);
822 if (msize < 0 || kern_msize < 0 || msize != kern_msize) {
823 pr_warn("struct_ops init_kern %s: Error in size of member %s: %zd != %zd(kernel)\n",
824 map->name, mname, (ssize_t)msize,
825 (ssize_t)kern_msize);
829 pr_debug("struct_ops init_kern %s: copy %s %u bytes from data(+%u) to kern_data(+%u)\n",
830 map->name, mname, (unsigned int)msize,
832 memcpy(kern_mdata, mdata, msize);
838 static int bpf_object__init_kern_struct_ops_maps(struct bpf_object *obj)
844 for (i = 0; i < obj->nr_maps; i++) {
847 if (!bpf_map__is_struct_ops(map))
850 err = bpf_map__init_kern_struct_ops(map, obj->btf,
859 static int bpf_object__init_struct_ops_maps(struct bpf_object *obj)
861 const struct btf_type *type, *datasec;
862 const struct btf_var_secinfo *vsi;
863 struct bpf_struct_ops *st_ops;
864 const char *tname, *var_name;
865 __s32 type_id, datasec_id;
866 const struct btf *btf;
870 if (obj->efile.st_ops_shndx == -1)
874 datasec_id = btf__find_by_name_kind(btf, STRUCT_OPS_SEC,
876 if (datasec_id < 0) {
877 pr_warn("struct_ops init: DATASEC %s not found\n",
882 datasec = btf__type_by_id(btf, datasec_id);
883 vsi = btf_var_secinfos(datasec);
884 for (i = 0; i < btf_vlen(datasec); i++, vsi++) {
885 type = btf__type_by_id(obj->btf, vsi->type);
886 var_name = btf__name_by_offset(obj->btf, type->name_off);
888 type_id = btf__resolve_type(obj->btf, vsi->type);
890 pr_warn("struct_ops init: Cannot resolve var type_id %u in DATASEC %s\n",
891 vsi->type, STRUCT_OPS_SEC);
895 type = btf__type_by_id(obj->btf, type_id);
896 tname = btf__name_by_offset(obj->btf, type->name_off);
898 pr_warn("struct_ops init: anonymous type is not supported\n");
901 if (!btf_is_struct(type)) {
902 pr_warn("struct_ops init: %s is not a struct\n", tname);
906 map = bpf_object__add_map(obj);
910 map->sec_idx = obj->efile.st_ops_shndx;
911 map->sec_offset = vsi->offset;
912 map->name = strdup(var_name);
916 map->def.type = BPF_MAP_TYPE_STRUCT_OPS;
917 map->def.key_size = sizeof(int);
918 map->def.value_size = type->size;
919 map->def.max_entries = 1;
921 map->st_ops = calloc(1, sizeof(*map->st_ops));
924 st_ops = map->st_ops;
925 st_ops->data = malloc(type->size);
926 st_ops->progs = calloc(btf_vlen(type), sizeof(*st_ops->progs));
927 st_ops->kern_func_off = malloc(btf_vlen(type) *
928 sizeof(*st_ops->kern_func_off));
929 if (!st_ops->data || !st_ops->progs || !st_ops->kern_func_off)
932 if (vsi->offset + type->size > obj->efile.st_ops_data->d_size) {
933 pr_warn("struct_ops init: var %s is beyond the end of DATASEC %s\n",
934 var_name, STRUCT_OPS_SEC);
939 obj->efile.st_ops_data->d_buf + vsi->offset,
941 st_ops->tname = tname;
943 st_ops->type_id = type_id;
945 pr_debug("struct_ops init: struct %s(type_id=%u) %s found at offset %u\n",
946 tname, type_id, var_name, vsi->offset);
952 static struct bpf_object *bpf_object__new(const char *path,
955 const char *obj_name)
957 struct bpf_object *obj;
960 obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
962 pr_warn("alloc memory failed for %s\n", path);
963 return ERR_PTR(-ENOMEM);
966 strcpy(obj->path, path);
968 strncpy(obj->name, obj_name, sizeof(obj->name) - 1);
969 obj->name[sizeof(obj->name) - 1] = 0;
971 /* Using basename() GNU version which doesn't modify arg. */
972 strncpy(obj->name, basename((void *)path),
973 sizeof(obj->name) - 1);
974 end = strchr(obj->name, '.');
981 * Caller of this function should also call
982 * bpf_object__elf_finish() after data collection to return
983 * obj_buf to user. If not, we should duplicate the buffer to
984 * avoid user freeing them before elf finish.
986 obj->efile.obj_buf = obj_buf;
987 obj->efile.obj_buf_sz = obj_buf_sz;
988 obj->efile.maps_shndx = -1;
989 obj->efile.btf_maps_shndx = -1;
990 obj->efile.data_shndx = -1;
991 obj->efile.rodata_shndx = -1;
992 obj->efile.bss_shndx = -1;
993 obj->efile.st_ops_shndx = -1;
994 obj->kconfig_map_idx = -1;
996 obj->kern_version = get_kernel_version();
999 INIT_LIST_HEAD(&obj->list);
1000 list_add(&obj->list, &bpf_objects_list);
1004 static void bpf_object__elf_finish(struct bpf_object *obj)
1006 if (!obj_elf_valid(obj))
1009 if (obj->efile.elf) {
1010 elf_end(obj->efile.elf);
1011 obj->efile.elf = NULL;
1013 obj->efile.symbols = NULL;
1014 obj->efile.data = NULL;
1015 obj->efile.rodata = NULL;
1016 obj->efile.bss = NULL;
1017 obj->efile.st_ops_data = NULL;
1019 zfree(&obj->efile.reloc_sects);
1020 obj->efile.nr_reloc_sects = 0;
1021 zclose(obj->efile.fd);
1022 obj->efile.obj_buf = NULL;
1023 obj->efile.obj_buf_sz = 0;
1026 static int bpf_object__elf_init(struct bpf_object *obj)
1031 if (obj_elf_valid(obj)) {
1032 pr_warn("elf init: internal error\n");
1033 return -LIBBPF_ERRNO__LIBELF;
1036 if (obj->efile.obj_buf_sz > 0) {
1038 * obj_buf should have been validated by
1039 * bpf_object__open_buffer().
1041 obj->efile.elf = elf_memory((char *)obj->efile.obj_buf,
1042 obj->efile.obj_buf_sz);
1044 obj->efile.fd = open(obj->path, O_RDONLY);
1045 if (obj->efile.fd < 0) {
1046 char errmsg[STRERR_BUFSIZE], *cp;
1049 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
1050 pr_warn("failed to open %s: %s\n", obj->path, cp);
1054 obj->efile.elf = elf_begin(obj->efile.fd,
1055 LIBBPF_ELF_C_READ_MMAP, NULL);
1058 if (!obj->efile.elf) {
1059 pr_warn("failed to open %s as ELF file\n", obj->path);
1060 err = -LIBBPF_ERRNO__LIBELF;
1064 if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
1065 pr_warn("failed to get EHDR from %s\n", obj->path);
1066 err = -LIBBPF_ERRNO__FORMAT;
1069 ep = &obj->efile.ehdr;
1071 /* Old LLVM set e_machine to EM_NONE */
1072 if (ep->e_type != ET_REL ||
1073 (ep->e_machine && ep->e_machine != EM_BPF)) {
1074 pr_warn("%s is not an eBPF object file\n", obj->path);
1075 err = -LIBBPF_ERRNO__FORMAT;
1081 bpf_object__elf_finish(obj);
1085 static int bpf_object__check_endianness(struct bpf_object *obj)
1087 #if __BYTE_ORDER == __LITTLE_ENDIAN
1088 if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
1090 #elif __BYTE_ORDER == __BIG_ENDIAN
1091 if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
1094 # error "Unrecognized __BYTE_ORDER__"
1096 pr_warn("endianness mismatch.\n");
1097 return -LIBBPF_ERRNO__ENDIAN;
1101 bpf_object__init_license(struct bpf_object *obj, void *data, size_t size)
1103 memcpy(obj->license, data, min(size, sizeof(obj->license) - 1));
1104 pr_debug("license of %s is %s\n", obj->path, obj->license);
1109 bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size)
1113 if (size != sizeof(kver)) {
1114 pr_warn("invalid kver section in %s\n", obj->path);
1115 return -LIBBPF_ERRNO__FORMAT;
1117 memcpy(&kver, data, sizeof(kver));
1118 obj->kern_version = kver;
1119 pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version);
1123 static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
1125 if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
1126 type == BPF_MAP_TYPE_HASH_OF_MAPS)
1131 static int bpf_object_search_section_size(const struct bpf_object *obj,
1132 const char *name, size_t *d_size)
1134 const GElf_Ehdr *ep = &obj->efile.ehdr;
1135 Elf *elf = obj->efile.elf;
1136 Elf_Scn *scn = NULL;
1139 while ((scn = elf_nextscn(elf, scn)) != NULL) {
1140 const char *sec_name;
1145 if (gelf_getshdr(scn, &sh) != &sh) {
1146 pr_warn("failed to get section(%d) header from %s\n",
1151 sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
1153 pr_warn("failed to get section(%d) name from %s\n",
1158 if (strcmp(name, sec_name))
1161 data = elf_getdata(scn, 0);
1163 pr_warn("failed to get section(%d) data from %s(%s)\n",
1164 idx, name, obj->path);
1168 *d_size = data->d_size;
1175 int bpf_object__section_size(const struct bpf_object *obj, const char *name,
1184 } else if (!strcmp(name, DATA_SEC)) {
1185 if (obj->efile.data)
1186 *size = obj->efile.data->d_size;
1187 } else if (!strcmp(name, BSS_SEC)) {
1189 *size = obj->efile.bss->d_size;
1190 } else if (!strcmp(name, RODATA_SEC)) {
1191 if (obj->efile.rodata)
1192 *size = obj->efile.rodata->d_size;
1193 } else if (!strcmp(name, STRUCT_OPS_SEC)) {
1194 if (obj->efile.st_ops_data)
1195 *size = obj->efile.st_ops_data->d_size;
1197 ret = bpf_object_search_section_size(obj, name, &d_size);
1202 return *size ? 0 : ret;
1205 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
1208 Elf_Data *symbols = obj->efile.symbols;
1215 for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
1218 if (!gelf_getsym(symbols, si, &sym))
1220 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
1221 GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
1224 sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
1227 pr_warn("failed to get sym name string for var %s\n",
1231 if (strcmp(name, sname) == 0) {
1232 *off = sym.st_value;
1240 static struct bpf_map *bpf_object__add_map(struct bpf_object *obj)
1242 struct bpf_map *new_maps;
1246 if (obj->nr_maps < obj->maps_cap)
1247 return &obj->maps[obj->nr_maps++];
1249 new_cap = max((size_t)4, obj->maps_cap * 3 / 2);
1250 new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps));
1252 pr_warn("alloc maps for object failed\n");
1253 return ERR_PTR(-ENOMEM);
1256 obj->maps_cap = new_cap;
1257 obj->maps = new_maps;
1259 /* zero out new maps */
1260 memset(obj->maps + obj->nr_maps, 0,
1261 (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps));
1263 * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin)
1264 * when failure (zclose won't close negative fd)).
1266 for (i = obj->nr_maps; i < obj->maps_cap; i++) {
1267 obj->maps[i].fd = -1;
1268 obj->maps[i].inner_map_fd = -1;
1271 return &obj->maps[obj->nr_maps++];
1274 static size_t bpf_map_mmap_sz(const struct bpf_map *map)
1276 long page_sz = sysconf(_SC_PAGE_SIZE);
1279 map_sz = (size_t)roundup(map->def.value_size, 8) * map->def.max_entries;
1280 map_sz = roundup(map_sz, page_sz);
1284 static char *internal_map_name(struct bpf_object *obj,
1285 enum libbpf_map_type type)
1287 char map_name[BPF_OBJ_NAME_LEN], *p;
1288 const char *sfx = libbpf_type_to_btf_name[type];
1289 int sfx_len = max((size_t)7, strlen(sfx));
1290 int pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1,
1293 snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name,
1294 sfx_len, libbpf_type_to_btf_name[type]);
1296 /* sanitise map name to characters allowed by kernel */
1297 for (p = map_name; *p && p < map_name + sizeof(map_name); p++)
1298 if (!isalnum(*p) && *p != '_' && *p != '.')
1301 return strdup(map_name);
1305 bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
1306 int sec_idx, void *data, size_t data_sz)
1308 struct bpf_map_def *def;
1309 struct bpf_map *map;
1312 map = bpf_object__add_map(obj);
1314 return PTR_ERR(map);
1316 map->libbpf_type = type;
1317 map->sec_idx = sec_idx;
1318 map->sec_offset = 0;
1319 map->name = internal_map_name(obj, type);
1321 pr_warn("failed to alloc map name\n");
1326 def->type = BPF_MAP_TYPE_ARRAY;
1327 def->key_size = sizeof(int);
1328 def->value_size = data_sz;
1329 def->max_entries = 1;
1330 def->map_flags = type == LIBBPF_MAP_RODATA || type == LIBBPF_MAP_KCONFIG
1331 ? BPF_F_RDONLY_PROG : 0;
1332 def->map_flags |= BPF_F_MMAPABLE;
1334 pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n",
1335 map->name, map->sec_idx, map->sec_offset, def->map_flags);
1337 map->mmaped = mmap(NULL, bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE,
1338 MAP_SHARED | MAP_ANONYMOUS, -1, 0);
1339 if (map->mmaped == MAP_FAILED) {
1342 pr_warn("failed to alloc map '%s' content buffer: %d\n",
1349 memcpy(map->mmaped, data, data_sz);
1351 pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name);
1355 static int bpf_object__init_global_data_maps(struct bpf_object *obj)
1360 * Populate obj->maps with libbpf internal maps.
1362 if (obj->efile.data_shndx >= 0) {
1363 err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
1364 obj->efile.data_shndx,
1365 obj->efile.data->d_buf,
1366 obj->efile.data->d_size);
1370 if (obj->efile.rodata_shndx >= 0) {
1371 err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
1372 obj->efile.rodata_shndx,
1373 obj->efile.rodata->d_buf,
1374 obj->efile.rodata->d_size);
1378 if (obj->efile.bss_shndx >= 0) {
1379 err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
1380 obj->efile.bss_shndx,
1382 obj->efile.bss->d_size);
1390 static struct extern_desc *find_extern_by_name(const struct bpf_object *obj,
1395 for (i = 0; i < obj->nr_extern; i++) {
1396 if (strcmp(obj->externs[i].name, name) == 0)
1397 return &obj->externs[i];
1402 static int set_ext_value_tri(struct extern_desc *ext, void *ext_val,
1405 switch (ext->type) {
1408 pr_warn("extern %s=%c should be tristate or char\n",
1412 *(bool *)ext_val = value == 'y' ? true : false;
1416 *(enum libbpf_tristate *)ext_val = TRI_YES;
1417 else if (value == 'm')
1418 *(enum libbpf_tristate *)ext_val = TRI_MODULE;
1419 else /* value == 'n' */
1420 *(enum libbpf_tristate *)ext_val = TRI_NO;
1423 *(char *)ext_val = value;
1429 pr_warn("extern %s=%c should be bool, tristate, or char\n",
1437 static int set_ext_value_str(struct extern_desc *ext, char *ext_val,
1442 if (ext->type != EXT_CHAR_ARR) {
1443 pr_warn("extern %s=%s should char array\n", ext->name, value);
1447 len = strlen(value);
1448 if (value[len - 1] != '"') {
1449 pr_warn("extern '%s': invalid string config '%s'\n",
1456 if (len >= ext->sz) {
1457 pr_warn("extern '%s': long string config %s of (%zu bytes) truncated to %d bytes\n",
1458 ext->name, value, len, ext->sz - 1);
1461 memcpy(ext_val, value + 1, len);
1462 ext_val[len] = '\0';
1467 static int parse_u64(const char *value, __u64 *res)
1473 *res = strtoull(value, &value_end, 0);
1476 pr_warn("failed to parse '%s' as integer: %d\n", value, err);
1480 pr_warn("failed to parse '%s' as integer completely\n", value);
1486 static bool is_ext_value_in_range(const struct extern_desc *ext, __u64 v)
1488 int bit_sz = ext->sz * 8;
1493 /* Validate that value stored in u64 fits in integer of `ext->sz`
1494 * bytes size without any loss of information. If the target integer
1495 * is signed, we rely on the following limits of integer type of
1496 * Y bits and subsequent transformation:
1498 * -2^(Y-1) <= X <= 2^(Y-1) - 1
1499 * 0 <= X + 2^(Y-1) <= 2^Y - 1
1500 * 0 <= X + 2^(Y-1) < 2^Y
1502 * For unsigned target integer, check that all the (64 - Y) bits are
1506 return v + (1ULL << (bit_sz - 1)) < (1ULL << bit_sz);
1508 return (v >> bit_sz) == 0;
1511 static int set_ext_value_num(struct extern_desc *ext, void *ext_val,
1514 if (ext->type != EXT_INT && ext->type != EXT_CHAR) {
1515 pr_warn("extern %s=%llu should be integer\n",
1516 ext->name, (unsigned long long)value);
1519 if (!is_ext_value_in_range(ext, value)) {
1520 pr_warn("extern %s=%llu value doesn't fit in %d bytes\n",
1521 ext->name, (unsigned long long)value, ext->sz);
1525 case 1: *(__u8 *)ext_val = value; break;
1526 case 2: *(__u16 *)ext_val = value; break;
1527 case 4: *(__u32 *)ext_val = value; break;
1528 case 8: *(__u64 *)ext_val = value; break;
1536 static int bpf_object__process_kconfig_line(struct bpf_object *obj,
1537 char *buf, void *data)
1539 struct extern_desc *ext;
1545 if (strncmp(buf, "CONFIG_", 7))
1548 sep = strchr(buf, '=');
1550 pr_warn("failed to parse '%s': no separator\n", buf);
1554 /* Trim ending '\n' */
1556 if (buf[len - 1] == '\n')
1557 buf[len - 1] = '\0';
1558 /* Split on '=' and ensure that a value is present. */
1562 pr_warn("failed to parse '%s': no value\n", buf);
1566 ext = find_extern_by_name(obj, buf);
1567 if (!ext || ext->is_set)
1570 ext_val = data + ext->data_off;
1574 case 'y': case 'n': case 'm':
1575 err = set_ext_value_tri(ext, ext_val, *value);
1578 err = set_ext_value_str(ext, ext_val, value);
1581 /* assume integer */
1582 err = parse_u64(value, &num);
1584 pr_warn("extern %s=%s should be integer\n",
1588 err = set_ext_value_num(ext, ext_val, num);
1593 pr_debug("extern %s=%s\n", ext->name, value);
1597 static int bpf_object__read_kconfig_file(struct bpf_object *obj, void *data)
1605 len = snprintf(buf, PATH_MAX, "/boot/config-%s", uts.release);
1608 else if (len >= PATH_MAX)
1609 return -ENAMETOOLONG;
1611 /* gzopen also accepts uncompressed files. */
1612 file = gzopen(buf, "r");
1614 file = gzopen("/proc/config.gz", "r");
1617 pr_warn("failed to open system Kconfig\n");
1621 while (gzgets(file, buf, sizeof(buf))) {
1622 err = bpf_object__process_kconfig_line(obj, buf, data);
1624 pr_warn("error parsing system Kconfig line '%s': %d\n",
1635 static int bpf_object__read_kconfig_mem(struct bpf_object *obj,
1636 const char *config, void *data)
1642 file = fmemopen((void *)config, strlen(config), "r");
1645 pr_warn("failed to open in-memory Kconfig: %d\n", err);
1649 while (fgets(buf, sizeof(buf), file)) {
1650 err = bpf_object__process_kconfig_line(obj, buf, data);
1652 pr_warn("error parsing in-memory Kconfig line '%s': %d\n",
1662 static int bpf_object__init_kconfig_map(struct bpf_object *obj)
1664 struct extern_desc *last_ext;
1668 if (obj->nr_extern == 0)
1671 last_ext = &obj->externs[obj->nr_extern - 1];
1672 map_sz = last_ext->data_off + last_ext->sz;
1674 err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG,
1675 obj->efile.symbols_shndx,
1680 obj->kconfig_map_idx = obj->nr_maps - 1;
1685 static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
1687 Elf_Data *symbols = obj->efile.symbols;
1688 int i, map_def_sz = 0, nr_maps = 0, nr_syms;
1689 Elf_Data *data = NULL;
1692 if (obj->efile.maps_shndx < 0)
1698 scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx);
1700 data = elf_getdata(scn, NULL);
1701 if (!scn || !data) {
1702 pr_warn("failed to get Elf_Data from map section %d\n",
1703 obj->efile.maps_shndx);
1708 * Count number of maps. Each map has a name.
1709 * Array of maps is not supported: only the first element is
1712 * TODO: Detect array of map and report error.
1714 nr_syms = symbols->d_size / sizeof(GElf_Sym);
1715 for (i = 0; i < nr_syms; i++) {
1718 if (!gelf_getsym(symbols, i, &sym))
1720 if (sym.st_shndx != obj->efile.maps_shndx)
1724 /* Assume equally sized map definitions */
1725 pr_debug("maps in %s: %d maps in %zd bytes\n",
1726 obj->path, nr_maps, data->d_size);
1728 if (!data->d_size || nr_maps == 0 || (data->d_size % nr_maps) != 0) {
1729 pr_warn("unable to determine map definition size section %s, %d maps in %zd bytes\n",
1730 obj->path, nr_maps, data->d_size);
1733 map_def_sz = data->d_size / nr_maps;
1735 /* Fill obj->maps using data in "maps" section. */
1736 for (i = 0; i < nr_syms; i++) {
1738 const char *map_name;
1739 struct bpf_map_def *def;
1740 struct bpf_map *map;
1742 if (!gelf_getsym(symbols, i, &sym))
1744 if (sym.st_shndx != obj->efile.maps_shndx)
1747 map = bpf_object__add_map(obj);
1749 return PTR_ERR(map);
1751 map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
1754 pr_warn("failed to get map #%d name sym string for obj %s\n",
1756 return -LIBBPF_ERRNO__FORMAT;
1759 map->libbpf_type = LIBBPF_MAP_UNSPEC;
1760 map->sec_idx = sym.st_shndx;
1761 map->sec_offset = sym.st_value;
1762 pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n",
1763 map_name, map->sec_idx, map->sec_offset);
1764 if (sym.st_value + map_def_sz > data->d_size) {
1765 pr_warn("corrupted maps section in %s: last map \"%s\" too small\n",
1766 obj->path, map_name);
1770 map->name = strdup(map_name);
1772 pr_warn("failed to alloc map name\n");
1775 pr_debug("map %d is \"%s\"\n", i, map->name);
1776 def = (struct bpf_map_def *)(data->d_buf + sym.st_value);
1778 * If the definition of the map in the object file fits in
1779 * bpf_map_def, copy it. Any extra fields in our version
1780 * of bpf_map_def will default to zero as a result of the
1783 if (map_def_sz <= sizeof(struct bpf_map_def)) {
1784 memcpy(&map->def, def, map_def_sz);
1787 * Here the map structure being read is bigger than what
1788 * we expect, truncate if the excess bits are all zero.
1789 * If they are not zero, reject this map as
1794 for (b = ((char *)def) + sizeof(struct bpf_map_def);
1795 b < ((char *)def) + map_def_sz; b++) {
1797 pr_warn("maps section in %s: \"%s\" has unrecognized, non-zero options\n",
1798 obj->path, map_name);
1803 memcpy(&map->def, def, sizeof(struct bpf_map_def));
1809 static const struct btf_type *
1810 skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id)
1812 const struct btf_type *t = btf__type_by_id(btf, id);
1817 while (btf_is_mod(t) || btf_is_typedef(t)) {
1820 t = btf__type_by_id(btf, t->type);
1826 static const struct btf_type *
1827 resolve_func_ptr(const struct btf *btf, __u32 id, __u32 *res_id)
1829 const struct btf_type *t;
1831 t = skip_mods_and_typedefs(btf, id, NULL);
1835 t = skip_mods_and_typedefs(btf, t->type, res_id);
1837 return btf_is_func_proto(t) ? t : NULL;
1841 * Fetch integer attribute of BTF map definition. Such attributes are
1842 * represented using a pointer to an array, in which dimensionality of array
1843 * encodes specified integer value. E.g., int (*type)[BPF_MAP_TYPE_ARRAY];
1844 * encodes `type => BPF_MAP_TYPE_ARRAY` key/value pair completely using BTF
1845 * type definition, while using only sizeof(void *) space in ELF data section.
1847 static bool get_map_field_int(const char *map_name, const struct btf *btf,
1848 const struct btf_type *def,
1849 const struct btf_member *m, __u32 *res)
1851 const struct btf_type *t = skip_mods_and_typedefs(btf, m->type, NULL);
1852 const char *name = btf__name_by_offset(btf, m->name_off);
1853 const struct btf_array *arr_info;
1854 const struct btf_type *arr_t;
1856 if (!btf_is_ptr(t)) {
1857 pr_warn("map '%s': attr '%s': expected PTR, got %u.\n",
1858 map_name, name, btf_kind(t));
1862 arr_t = btf__type_by_id(btf, t->type);
1864 pr_warn("map '%s': attr '%s': type [%u] not found.\n",
1865 map_name, name, t->type);
1868 if (!btf_is_array(arr_t)) {
1869 pr_warn("map '%s': attr '%s': expected ARRAY, got %u.\n",
1870 map_name, name, btf_kind(arr_t));
1873 arr_info = btf_array(arr_t);
1874 *res = arr_info->nelems;
1878 static int build_map_pin_path(struct bpf_map *map, const char *path)
1884 path = "/sys/fs/bpf";
1886 len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
1889 else if (len >= PATH_MAX)
1890 return -ENAMETOOLONG;
1892 err = bpf_map__set_pin_path(map, buf);
1899 static int bpf_object__init_user_btf_map(struct bpf_object *obj,
1900 const struct btf_type *sec,
1901 int var_idx, int sec_idx,
1902 const Elf_Data *data, bool strict,
1903 const char *pin_root_path)
1905 const struct btf_type *var, *def, *t;
1906 const struct btf_var_secinfo *vi;
1907 const struct btf_var *var_extra;
1908 const struct btf_member *m;
1909 const char *map_name;
1910 struct bpf_map *map;
1913 vi = btf_var_secinfos(sec) + var_idx;
1914 var = btf__type_by_id(obj->btf, vi->type);
1915 var_extra = btf_var(var);
1916 map_name = btf__name_by_offset(obj->btf, var->name_off);
1917 vlen = btf_vlen(var);
1919 if (map_name == NULL || map_name[0] == '\0') {
1920 pr_warn("map #%d: empty name.\n", var_idx);
1923 if ((__u64)vi->offset + vi->size > data->d_size) {
1924 pr_warn("map '%s' BTF data is corrupted.\n", map_name);
1927 if (!btf_is_var(var)) {
1928 pr_warn("map '%s': unexpected var kind %u.\n",
1929 map_name, btf_kind(var));
1932 if (var_extra->linkage != BTF_VAR_GLOBAL_ALLOCATED &&
1933 var_extra->linkage != BTF_VAR_STATIC) {
1934 pr_warn("map '%s': unsupported var linkage %u.\n",
1935 map_name, var_extra->linkage);
1939 def = skip_mods_and_typedefs(obj->btf, var->type, NULL);
1940 if (!btf_is_struct(def)) {
1941 pr_warn("map '%s': unexpected def kind %u.\n",
1942 map_name, btf_kind(var));
1945 if (def->size > vi->size) {
1946 pr_warn("map '%s': invalid def size.\n", map_name);
1950 map = bpf_object__add_map(obj);
1952 return PTR_ERR(map);
1953 map->name = strdup(map_name);
1955 pr_warn("map '%s': failed to alloc map name.\n", map_name);
1958 map->libbpf_type = LIBBPF_MAP_UNSPEC;
1959 map->def.type = BPF_MAP_TYPE_UNSPEC;
1960 map->sec_idx = sec_idx;
1961 map->sec_offset = vi->offset;
1962 pr_debug("map '%s': at sec_idx %d, offset %zu.\n",
1963 map_name, map->sec_idx, map->sec_offset);
1965 vlen = btf_vlen(def);
1966 m = btf_members(def);
1967 for (i = 0; i < vlen; i++, m++) {
1968 const char *name = btf__name_by_offset(obj->btf, m->name_off);
1971 pr_warn("map '%s': invalid field #%d.\n", map_name, i);
1974 if (strcmp(name, "type") == 0) {
1975 if (!get_map_field_int(map_name, obj->btf, def, m,
1978 pr_debug("map '%s': found type = %u.\n",
1979 map_name, map->def.type);
1980 } else if (strcmp(name, "max_entries") == 0) {
1981 if (!get_map_field_int(map_name, obj->btf, def, m,
1982 &map->def.max_entries))
1984 pr_debug("map '%s': found max_entries = %u.\n",
1985 map_name, map->def.max_entries);
1986 } else if (strcmp(name, "map_flags") == 0) {
1987 if (!get_map_field_int(map_name, obj->btf, def, m,
1988 &map->def.map_flags))
1990 pr_debug("map '%s': found map_flags = %u.\n",
1991 map_name, map->def.map_flags);
1992 } else if (strcmp(name, "key_size") == 0) {
1995 if (!get_map_field_int(map_name, obj->btf, def, m,
1998 pr_debug("map '%s': found key_size = %u.\n",
2000 if (map->def.key_size && map->def.key_size != sz) {
2001 pr_warn("map '%s': conflicting key size %u != %u.\n",
2002 map_name, map->def.key_size, sz);
2005 map->def.key_size = sz;
2006 } else if (strcmp(name, "key") == 0) {
2009 t = btf__type_by_id(obj->btf, m->type);
2011 pr_warn("map '%s': key type [%d] not found.\n",
2015 if (!btf_is_ptr(t)) {
2016 pr_warn("map '%s': key spec is not PTR: %u.\n",
2017 map_name, btf_kind(t));
2020 sz = btf__resolve_size(obj->btf, t->type);
2022 pr_warn("map '%s': can't determine key size for type [%u]: %zd.\n",
2023 map_name, t->type, (ssize_t)sz);
2026 pr_debug("map '%s': found key [%u], sz = %zd.\n",
2027 map_name, t->type, (ssize_t)sz);
2028 if (map->def.key_size && map->def.key_size != sz) {
2029 pr_warn("map '%s': conflicting key size %u != %zd.\n",
2030 map_name, map->def.key_size, (ssize_t)sz);
2033 map->def.key_size = sz;
2034 map->btf_key_type_id = t->type;
2035 } else if (strcmp(name, "value_size") == 0) {
2038 if (!get_map_field_int(map_name, obj->btf, def, m,
2041 pr_debug("map '%s': found value_size = %u.\n",
2043 if (map->def.value_size && map->def.value_size != sz) {
2044 pr_warn("map '%s': conflicting value size %u != %u.\n",
2045 map_name, map->def.value_size, sz);
2048 map->def.value_size = sz;
2049 } else if (strcmp(name, "value") == 0) {
2052 t = btf__type_by_id(obj->btf, m->type);
2054 pr_warn("map '%s': value type [%d] not found.\n",
2058 if (!btf_is_ptr(t)) {
2059 pr_warn("map '%s': value spec is not PTR: %u.\n",
2060 map_name, btf_kind(t));
2063 sz = btf__resolve_size(obj->btf, t->type);
2065 pr_warn("map '%s': can't determine value size for type [%u]: %zd.\n",
2066 map_name, t->type, (ssize_t)sz);
2069 pr_debug("map '%s': found value [%u], sz = %zd.\n",
2070 map_name, t->type, (ssize_t)sz);
2071 if (map->def.value_size && map->def.value_size != sz) {
2072 pr_warn("map '%s': conflicting value size %u != %zd.\n",
2073 map_name, map->def.value_size, (ssize_t)sz);
2076 map->def.value_size = sz;
2077 map->btf_value_type_id = t->type;
2078 } else if (strcmp(name, "pinning") == 0) {
2082 if (!get_map_field_int(map_name, obj->btf, def, m,
2085 pr_debug("map '%s': found pinning = %u.\n",
2088 if (val != LIBBPF_PIN_NONE &&
2089 val != LIBBPF_PIN_BY_NAME) {
2090 pr_warn("map '%s': invalid pinning value %u.\n",
2094 if (val == LIBBPF_PIN_BY_NAME) {
2095 err = build_map_pin_path(map, pin_root_path);
2097 pr_warn("map '%s': couldn't build pin path.\n",
2104 pr_warn("map '%s': unknown field '%s'.\n",
2108 pr_debug("map '%s': ignoring unknown field '%s'.\n",
2113 if (map->def.type == BPF_MAP_TYPE_UNSPEC) {
2114 pr_warn("map '%s': map type isn't specified.\n", map_name);
2121 static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
2122 const char *pin_root_path)
2124 const struct btf_type *sec = NULL;
2125 int nr_types, i, vlen, err;
2126 const struct btf_type *t;
2131 if (obj->efile.btf_maps_shndx < 0)
2134 scn = elf_getscn(obj->efile.elf, obj->efile.btf_maps_shndx);
2136 data = elf_getdata(scn, NULL);
2137 if (!scn || !data) {
2138 pr_warn("failed to get Elf_Data from map section %d (%s)\n",
2139 obj->efile.maps_shndx, MAPS_ELF_SEC);
2143 nr_types = btf__get_nr_types(obj->btf);
2144 for (i = 1; i <= nr_types; i++) {
2145 t = btf__type_by_id(obj->btf, i);
2146 if (!btf_is_datasec(t))
2148 name = btf__name_by_offset(obj->btf, t->name_off);
2149 if (strcmp(name, MAPS_ELF_SEC) == 0) {
2156 pr_warn("DATASEC '%s' not found.\n", MAPS_ELF_SEC);
2160 vlen = btf_vlen(sec);
2161 for (i = 0; i < vlen; i++) {
2162 err = bpf_object__init_user_btf_map(obj, sec, i,
2163 obj->efile.btf_maps_shndx,
2173 static int bpf_object__init_maps(struct bpf_object *obj,
2174 const struct bpf_object_open_opts *opts)
2176 const char *pin_root_path;
2180 strict = !OPTS_GET(opts, relaxed_maps, false);
2181 pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
2183 err = bpf_object__init_user_maps(obj, strict);
2184 err = err ?: bpf_object__init_user_btf_maps(obj, strict, pin_root_path);
2185 err = err ?: bpf_object__init_global_data_maps(obj);
2186 err = err ?: bpf_object__init_kconfig_map(obj);
2187 err = err ?: bpf_object__init_struct_ops_maps(obj);
2194 static bool section_have_execinstr(struct bpf_object *obj, int idx)
2199 scn = elf_getscn(obj->efile.elf, idx);
2203 if (gelf_getshdr(scn, &sh) != &sh)
2206 if (sh.sh_flags & SHF_EXECINSTR)
2212 static void bpf_object__sanitize_btf(struct bpf_object *obj)
2214 bool has_func_global = obj->caps.btf_func_global;
2215 bool has_datasec = obj->caps.btf_datasec;
2216 bool has_func = obj->caps.btf_func;
2217 struct btf *btf = obj->btf;
2221 if (!obj->btf || (has_func && has_datasec && has_func_global))
2224 for (i = 1; i <= btf__get_nr_types(btf); i++) {
2225 t = (struct btf_type *)btf__type_by_id(btf, i);
2227 if (!has_datasec && btf_is_var(t)) {
2228 /* replace VAR with INT */
2229 t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
2231 * using size = 1 is the safest choice, 4 will be too
2232 * big and cause kernel BTF validation failure if
2233 * original variable took less than 4 bytes
2236 *(int *)(t + 1) = BTF_INT_ENC(0, 0, 8);
2237 } else if (!has_datasec && btf_is_datasec(t)) {
2238 /* replace DATASEC with STRUCT */
2239 const struct btf_var_secinfo *v = btf_var_secinfos(t);
2240 struct btf_member *m = btf_members(t);
2241 struct btf_type *vt;
2244 name = (char *)btf__name_by_offset(btf, t->name_off);
2252 t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, vlen);
2253 for (j = 0; j < vlen; j++, v++, m++) {
2254 /* order of field assignments is important */
2255 m->offset = v->offset * 8;
2257 /* preserve variable name as member name */
2258 vt = (void *)btf__type_by_id(btf, v->type);
2259 m->name_off = vt->name_off;
2261 } else if (!has_func && btf_is_func_proto(t)) {
2262 /* replace FUNC_PROTO with ENUM */
2264 t->info = BTF_INFO_ENC(BTF_KIND_ENUM, 0, vlen);
2265 t->size = sizeof(__u32); /* kernel enforced */
2266 } else if (!has_func && btf_is_func(t)) {
2267 /* replace FUNC with TYPEDEF */
2268 t->info = BTF_INFO_ENC(BTF_KIND_TYPEDEF, 0, 0);
2269 } else if (!has_func_global && btf_is_func(t)) {
2270 /* replace BTF_FUNC_GLOBAL with BTF_FUNC_STATIC */
2271 t->info = BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0);
2276 static void bpf_object__sanitize_btf_ext(struct bpf_object *obj)
2281 if (!obj->caps.btf_func) {
2282 btf_ext__free(obj->btf_ext);
2283 obj->btf_ext = NULL;
2287 static bool bpf_object__is_btf_mandatory(const struct bpf_object *obj)
2289 return obj->efile.btf_maps_shndx >= 0 ||
2290 obj->efile.st_ops_shndx >= 0 ||
2294 static int bpf_object__init_btf(struct bpf_object *obj,
2296 Elf_Data *btf_ext_data)
2301 obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
2302 if (IS_ERR(obj->btf)) {
2303 err = PTR_ERR(obj->btf);
2305 pr_warn("Error loading ELF section %s: %d.\n",
2313 pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
2314 BTF_EXT_ELF_SEC, BTF_ELF_SEC);
2317 obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
2318 btf_ext_data->d_size);
2319 if (IS_ERR(obj->btf_ext)) {
2320 pr_warn("Error loading ELF section %s: %ld. Ignored and continue.\n",
2321 BTF_EXT_ELF_SEC, PTR_ERR(obj->btf_ext));
2322 obj->btf_ext = NULL;
2327 if (err && bpf_object__is_btf_mandatory(obj)) {
2328 pr_warn("BTF is required, but is missing or corrupted.\n");
2334 static int bpf_object__finalize_btf(struct bpf_object *obj)
2341 err = btf__finalize_data(obj, obj->btf);
2345 pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
2346 btf__free(obj->btf);
2348 btf_ext__free(obj->btf_ext);
2349 obj->btf_ext = NULL;
2351 if (bpf_object__is_btf_mandatory(obj)) {
2352 pr_warn("BTF is required, but is missing or corrupted.\n");
2358 static inline bool libbpf_prog_needs_vmlinux_btf(struct bpf_program *prog)
2360 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS)
2363 /* BPF_PROG_TYPE_TRACING programs which do not attach to other programs
2364 * also need vmlinux BTF
2366 if (prog->type == BPF_PROG_TYPE_TRACING && !prog->attach_prog_fd)
2372 static int bpf_object__load_vmlinux_btf(struct bpf_object *obj)
2374 struct bpf_program *prog;
2377 bpf_object__for_each_program(prog, obj) {
2378 if (libbpf_prog_needs_vmlinux_btf(prog)) {
2379 obj->btf_vmlinux = libbpf_find_kernel_btf();
2380 if (IS_ERR(obj->btf_vmlinux)) {
2381 err = PTR_ERR(obj->btf_vmlinux);
2382 pr_warn("Error loading vmlinux BTF: %d\n", err);
2383 obj->btf_vmlinux = NULL;
2393 static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
2400 bpf_object__sanitize_btf(obj);
2401 bpf_object__sanitize_btf_ext(obj);
2403 err = btf__load(obj->btf);
2405 pr_warn("Error loading %s into kernel: %d.\n",
2407 btf__free(obj->btf);
2409 /* btf_ext can't exist without btf, so free it as well */
2411 btf_ext__free(obj->btf_ext);
2412 obj->btf_ext = NULL;
2415 if (bpf_object__is_btf_mandatory(obj))
2421 static int bpf_object__elf_collect(struct bpf_object *obj)
2423 Elf *elf = obj->efile.elf;
2424 GElf_Ehdr *ep = &obj->efile.ehdr;
2425 Elf_Data *btf_ext_data = NULL;
2426 Elf_Data *btf_data = NULL;
2427 Elf_Scn *scn = NULL;
2428 int idx = 0, err = 0;
2430 /* Elf is corrupted/truncated, avoid calling elf_strptr. */
2431 if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
2432 pr_warn("failed to get e_shstrndx from %s\n", obj->path);
2433 return -LIBBPF_ERRNO__FORMAT;
2436 while ((scn = elf_nextscn(elf, scn)) != NULL) {
2442 if (gelf_getshdr(scn, &sh) != &sh) {
2443 pr_warn("failed to get section(%d) header from %s\n",
2445 return -LIBBPF_ERRNO__FORMAT;
2448 name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
2450 pr_warn("failed to get section(%d) name from %s\n",
2452 return -LIBBPF_ERRNO__FORMAT;
2455 data = elf_getdata(scn, 0);
2457 pr_warn("failed to get section(%d) data from %s(%s)\n",
2458 idx, name, obj->path);
2459 return -LIBBPF_ERRNO__FORMAT;
2461 pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
2462 idx, name, (unsigned long)data->d_size,
2463 (int)sh.sh_link, (unsigned long)sh.sh_flags,
2466 if (strcmp(name, "license") == 0) {
2467 err = bpf_object__init_license(obj,
2472 } else if (strcmp(name, "version") == 0) {
2473 err = bpf_object__init_kversion(obj,
2478 } else if (strcmp(name, "maps") == 0) {
2479 obj->efile.maps_shndx = idx;
2480 } else if (strcmp(name, MAPS_ELF_SEC) == 0) {
2481 obj->efile.btf_maps_shndx = idx;
2482 } else if (strcmp(name, BTF_ELF_SEC) == 0) {
2484 } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
2485 btf_ext_data = data;
2486 } else if (sh.sh_type == SHT_SYMTAB) {
2487 if (obj->efile.symbols) {
2488 pr_warn("bpf: multiple SYMTAB in %s\n",
2490 return -LIBBPF_ERRNO__FORMAT;
2492 obj->efile.symbols = data;
2493 obj->efile.symbols_shndx = idx;
2494 obj->efile.strtabidx = sh.sh_link;
2495 } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
2496 if (sh.sh_flags & SHF_EXECINSTR) {
2497 if (strcmp(name, ".text") == 0)
2498 obj->efile.text_shndx = idx;
2499 err = bpf_object__add_program(obj, data->d_buf,
2503 char errmsg[STRERR_BUFSIZE];
2506 cp = libbpf_strerror_r(-err, errmsg,
2508 pr_warn("failed to alloc program %s (%s): %s",
2509 name, obj->path, cp);
2512 } else if (strcmp(name, DATA_SEC) == 0) {
2513 obj->efile.data = data;
2514 obj->efile.data_shndx = idx;
2515 } else if (strcmp(name, RODATA_SEC) == 0) {
2516 obj->efile.rodata = data;
2517 obj->efile.rodata_shndx = idx;
2518 } else if (strcmp(name, STRUCT_OPS_SEC) == 0) {
2519 obj->efile.st_ops_data = data;
2520 obj->efile.st_ops_shndx = idx;
2522 pr_debug("skip section(%d) %s\n", idx, name);
2524 } else if (sh.sh_type == SHT_REL) {
2525 int nr_sects = obj->efile.nr_reloc_sects;
2526 void *sects = obj->efile.reloc_sects;
2527 int sec = sh.sh_info; /* points to other section */
2529 /* Only do relo for section with exec instructions */
2530 if (!section_have_execinstr(obj, sec) &&
2531 strcmp(name, ".rel" STRUCT_OPS_SEC)) {
2532 pr_debug("skip relo %s(%d) for section(%d)\n",
2537 sects = reallocarray(sects, nr_sects + 1,
2538 sizeof(*obj->efile.reloc_sects));
2540 pr_warn("reloc_sects realloc failed\n");
2544 obj->efile.reloc_sects = sects;
2545 obj->efile.nr_reloc_sects++;
2547 obj->efile.reloc_sects[nr_sects].shdr = sh;
2548 obj->efile.reloc_sects[nr_sects].data = data;
2549 } else if (sh.sh_type == SHT_NOBITS &&
2550 strcmp(name, BSS_SEC) == 0) {
2551 obj->efile.bss = data;
2552 obj->efile.bss_shndx = idx;
2554 pr_debug("skip section(%d) %s\n", idx, name);
2558 if (!obj->efile.strtabidx || obj->efile.strtabidx > idx) {
2559 pr_warn("Corrupted ELF file: index of strtab invalid\n");
2560 return -LIBBPF_ERRNO__FORMAT;
2562 return bpf_object__init_btf(obj, btf_data, btf_ext_data);
2565 static bool sym_is_extern(const GElf_Sym *sym)
2567 int bind = GELF_ST_BIND(sym->st_info);
2568 /* externs are symbols w/ type=NOTYPE, bind=GLOBAL|WEAK, section=UND */
2569 return sym->st_shndx == SHN_UNDEF &&
2570 (bind == STB_GLOBAL || bind == STB_WEAK) &&
2571 GELF_ST_TYPE(sym->st_info) == STT_NOTYPE;
2574 static int find_extern_btf_id(const struct btf *btf, const char *ext_name)
2576 const struct btf_type *t;
2577 const char *var_name;
2583 n = btf__get_nr_types(btf);
2584 for (i = 1; i <= n; i++) {
2585 t = btf__type_by_id(btf, i);
2590 var_name = btf__name_by_offset(btf, t->name_off);
2591 if (strcmp(var_name, ext_name))
2594 if (btf_var(t)->linkage != BTF_VAR_GLOBAL_EXTERN)
2603 static enum extern_type find_extern_type(const struct btf *btf, int id,
2606 const struct btf_type *t;
2609 t = skip_mods_and_typedefs(btf, id, NULL);
2610 name = btf__name_by_offset(btf, t->name_off);
2614 switch (btf_kind(t)) {
2615 case BTF_KIND_INT: {
2616 int enc = btf_int_encoding(t);
2618 if (enc & BTF_INT_BOOL)
2619 return t->size == 1 ? EXT_BOOL : EXT_UNKNOWN;
2621 *is_signed = enc & BTF_INT_SIGNED;
2624 if (t->size < 1 || t->size > 8 || (t->size & (t->size - 1)))
2631 if (strcmp(name, "libbpf_tristate"))
2633 return EXT_TRISTATE;
2634 case BTF_KIND_ARRAY:
2635 if (btf_array(t)->nelems == 0)
2637 if (find_extern_type(btf, btf_array(t)->type, NULL) != EXT_CHAR)
2639 return EXT_CHAR_ARR;
2645 static int cmp_externs(const void *_a, const void *_b)
2647 const struct extern_desc *a = _a;
2648 const struct extern_desc *b = _b;
2650 /* descending order by alignment requirements */
2651 if (a->align != b->align)
2652 return a->align > b->align ? -1 : 1;
2653 /* ascending order by size, within same alignment class */
2655 return a->sz < b->sz ? -1 : 1;
2656 /* resolve ties by name */
2657 return strcmp(a->name, b->name);
2660 static int bpf_object__collect_externs(struct bpf_object *obj)
2662 const struct btf_type *t;
2663 struct extern_desc *ext;
2664 int i, n, off, btf_id;
2665 struct btf_type *sec;
2666 const char *ext_name;
2670 if (!obj->efile.symbols)
2673 scn = elf_getscn(obj->efile.elf, obj->efile.symbols_shndx);
2675 return -LIBBPF_ERRNO__FORMAT;
2676 if (gelf_getshdr(scn, &sh) != &sh)
2677 return -LIBBPF_ERRNO__FORMAT;
2678 n = sh.sh_size / sh.sh_entsize;
2680 pr_debug("looking for externs among %d symbols...\n", n);
2681 for (i = 0; i < n; i++) {
2684 if (!gelf_getsym(obj->efile.symbols, i, &sym))
2685 return -LIBBPF_ERRNO__FORMAT;
2686 if (!sym_is_extern(&sym))
2688 ext_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
2690 if (!ext_name || !ext_name[0])
2694 ext = reallocarray(ext, obj->nr_extern + 1, sizeof(*ext));
2698 ext = &ext[obj->nr_extern];
2699 memset(ext, 0, sizeof(*ext));
2702 ext->btf_id = find_extern_btf_id(obj->btf, ext_name);
2703 if (ext->btf_id <= 0) {
2704 pr_warn("failed to find BTF for extern '%s': %d\n",
2705 ext_name, ext->btf_id);
2708 t = btf__type_by_id(obj->btf, ext->btf_id);
2709 ext->name = btf__name_by_offset(obj->btf, t->name_off);
2711 ext->is_weak = GELF_ST_BIND(sym.st_info) == STB_WEAK;
2712 ext->sz = btf__resolve_size(obj->btf, t->type);
2714 pr_warn("failed to resolve size of extern '%s': %d\n",
2718 ext->align = btf__align_of(obj->btf, t->type);
2719 if (ext->align <= 0) {
2720 pr_warn("failed to determine alignment of extern '%s': %d\n",
2721 ext_name, ext->align);
2724 ext->type = find_extern_type(obj->btf, t->type,
2726 if (ext->type == EXT_UNKNOWN) {
2727 pr_warn("extern '%s' type is unsupported\n", ext_name);
2731 pr_debug("collected %d externs total\n", obj->nr_extern);
2733 if (!obj->nr_extern)
2736 /* sort externs by (alignment, size, name) and calculate their offsets
2738 qsort(obj->externs, obj->nr_extern, sizeof(*ext), cmp_externs);
2740 for (i = 0; i < obj->nr_extern; i++) {
2741 ext = &obj->externs[i];
2742 ext->data_off = roundup(off, ext->align);
2743 off = ext->data_off + ext->sz;
2744 pr_debug("extern #%d: symbol %d, off %u, name %s\n",
2745 i, ext->sym_idx, ext->data_off, ext->name);
2748 btf_id = btf__find_by_name(obj->btf, KCONFIG_SEC);
2750 pr_warn("no BTF info found for '%s' datasec\n", KCONFIG_SEC);
2754 sec = (struct btf_type *)btf__type_by_id(obj->btf, btf_id);
2757 for (i = 0; i < n; i++) {
2758 struct btf_var_secinfo *vs = btf_var_secinfos(sec) + i;
2760 t = btf__type_by_id(obj->btf, vs->type);
2761 ext_name = btf__name_by_offset(obj->btf, t->name_off);
2762 ext = find_extern_by_name(obj, ext_name);
2764 pr_warn("failed to find extern definition for BTF var '%s'\n",
2768 vs->offset = ext->data_off;
2769 btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED;
2775 static struct bpf_program *
2776 bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
2778 struct bpf_program *prog;
2781 for (i = 0; i < obj->nr_programs; i++) {
2782 prog = &obj->programs[i];
2783 if (prog->idx == idx)
2789 struct bpf_program *
2790 bpf_object__find_program_by_title(const struct bpf_object *obj,
2793 struct bpf_program *pos;
2795 bpf_object__for_each_program(pos, obj) {
2796 if (pos->section_name && !strcmp(pos->section_name, title))
2802 struct bpf_program *
2803 bpf_object__find_program_by_name(const struct bpf_object *obj,
2806 struct bpf_program *prog;
2808 bpf_object__for_each_program(prog, obj) {
2809 if (!strcmp(prog->name, name))
2815 static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
2818 return shndx == obj->efile.data_shndx ||
2819 shndx == obj->efile.bss_shndx ||
2820 shndx == obj->efile.rodata_shndx;
2823 static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
2826 return shndx == obj->efile.maps_shndx ||
2827 shndx == obj->efile.btf_maps_shndx;
2830 static enum libbpf_map_type
2831 bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
2833 if (shndx == obj->efile.data_shndx)
2834 return LIBBPF_MAP_DATA;
2835 else if (shndx == obj->efile.bss_shndx)
2836 return LIBBPF_MAP_BSS;
2837 else if (shndx == obj->efile.rodata_shndx)
2838 return LIBBPF_MAP_RODATA;
2839 else if (shndx == obj->efile.symbols_shndx)
2840 return LIBBPF_MAP_KCONFIG;
2842 return LIBBPF_MAP_UNSPEC;
2845 static int bpf_program__record_reloc(struct bpf_program *prog,
2846 struct reloc_desc *reloc_desc,
2847 __u32 insn_idx, const char *name,
2848 const GElf_Sym *sym, const GElf_Rel *rel)
2850 struct bpf_insn *insn = &prog->insns[insn_idx];
2851 size_t map_idx, nr_maps = prog->obj->nr_maps;
2852 struct bpf_object *obj = prog->obj;
2853 __u32 shdr_idx = sym->st_shndx;
2854 enum libbpf_map_type type;
2855 struct bpf_map *map;
2857 /* sub-program call relocation */
2858 if (insn->code == (BPF_JMP | BPF_CALL)) {
2859 if (insn->src_reg != BPF_PSEUDO_CALL) {
2860 pr_warn("incorrect bpf_call opcode\n");
2861 return -LIBBPF_ERRNO__RELOC;
2863 /* text_shndx can be 0, if no default "main" program exists */
2864 if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
2865 pr_warn("bad call relo against section %u\n", shdr_idx);
2866 return -LIBBPF_ERRNO__RELOC;
2868 if (sym->st_value % 8) {
2869 pr_warn("bad call relo offset: %zu\n",
2870 (size_t)sym->st_value);
2871 return -LIBBPF_ERRNO__RELOC;
2873 reloc_desc->type = RELO_CALL;
2874 reloc_desc->insn_idx = insn_idx;
2875 reloc_desc->sym_off = sym->st_value;
2876 obj->has_pseudo_calls = true;
2880 if (insn->code != (BPF_LD | BPF_IMM | BPF_DW)) {
2881 pr_warn("invalid relo for insns[%d].code 0x%x\n",
2882 insn_idx, insn->code);
2883 return -LIBBPF_ERRNO__RELOC;
2886 if (sym_is_extern(sym)) {
2887 int sym_idx = GELF_R_SYM(rel->r_info);
2888 int i, n = obj->nr_extern;
2889 struct extern_desc *ext;
2891 for (i = 0; i < n; i++) {
2892 ext = &obj->externs[i];
2893 if (ext->sym_idx == sym_idx)
2897 pr_warn("extern relo failed to find extern for sym %d\n",
2899 return -LIBBPF_ERRNO__RELOC;
2901 pr_debug("found extern #%d '%s' (sym %d, off %u) for insn %u\n",
2902 i, ext->name, ext->sym_idx, ext->data_off, insn_idx);
2903 reloc_desc->type = RELO_EXTERN;
2904 reloc_desc->insn_idx = insn_idx;
2905 reloc_desc->sym_off = ext->data_off;
2909 if (!shdr_idx || shdr_idx >= SHN_LORESERVE) {
2910 pr_warn("invalid relo for \'%s\' in special section 0x%x; forgot to initialize global var?..\n",
2912 return -LIBBPF_ERRNO__RELOC;
2915 type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
2917 /* generic map reference relocation */
2918 if (type == LIBBPF_MAP_UNSPEC) {
2919 if (!bpf_object__shndx_is_maps(obj, shdr_idx)) {
2920 pr_warn("bad map relo against section %u\n",
2922 return -LIBBPF_ERRNO__RELOC;
2924 for (map_idx = 0; map_idx < nr_maps; map_idx++) {
2925 map = &obj->maps[map_idx];
2926 if (map->libbpf_type != type ||
2927 map->sec_idx != sym->st_shndx ||
2928 map->sec_offset != sym->st_value)
2930 pr_debug("found map %zd (%s, sec %d, off %zu) for insn %u\n",
2931 map_idx, map->name, map->sec_idx,
2932 map->sec_offset, insn_idx);
2935 if (map_idx >= nr_maps) {
2936 pr_warn("map relo failed to find map for sec %u, off %zu\n",
2937 shdr_idx, (size_t)sym->st_value);
2938 return -LIBBPF_ERRNO__RELOC;
2940 reloc_desc->type = RELO_LD64;
2941 reloc_desc->insn_idx = insn_idx;
2942 reloc_desc->map_idx = map_idx;
2943 reloc_desc->sym_off = 0; /* sym->st_value determines map_idx */
2947 /* global data map relocation */
2948 if (!bpf_object__shndx_is_data(obj, shdr_idx)) {
2949 pr_warn("bad data relo against section %u\n", shdr_idx);
2950 return -LIBBPF_ERRNO__RELOC;
2952 for (map_idx = 0; map_idx < nr_maps; map_idx++) {
2953 map = &obj->maps[map_idx];
2954 if (map->libbpf_type != type)
2956 pr_debug("found data map %zd (%s, sec %d, off %zu) for insn %u\n",
2957 map_idx, map->name, map->sec_idx, map->sec_offset,
2961 if (map_idx >= nr_maps) {
2962 pr_warn("data relo failed to find map for sec %u\n",
2964 return -LIBBPF_ERRNO__RELOC;
2967 reloc_desc->type = RELO_DATA;
2968 reloc_desc->insn_idx = insn_idx;
2969 reloc_desc->map_idx = map_idx;
2970 reloc_desc->sym_off = sym->st_value;
2975 bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
2976 Elf_Data *data, struct bpf_object *obj)
2978 Elf_Data *symbols = obj->efile.symbols;
2981 pr_debug("collecting relocating info for: '%s'\n", prog->section_name);
2982 nrels = shdr->sh_size / shdr->sh_entsize;
2984 prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
2985 if (!prog->reloc_desc) {
2986 pr_warn("failed to alloc memory in relocation\n");
2989 prog->nr_reloc = nrels;
2991 for (i = 0; i < nrels; i++) {
2997 if (!gelf_getrel(data, i, &rel)) {
2998 pr_warn("relocation: failed to get %d reloc\n", i);
2999 return -LIBBPF_ERRNO__FORMAT;
3001 if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
3002 pr_warn("relocation: symbol %"PRIx64" not found\n",
3003 GELF_R_SYM(rel.r_info));
3004 return -LIBBPF_ERRNO__FORMAT;
3006 if (rel.r_offset % sizeof(struct bpf_insn))
3007 return -LIBBPF_ERRNO__FORMAT;
3009 insn_idx = rel.r_offset / sizeof(struct bpf_insn);
3010 name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
3011 sym.st_name) ? : "<?>";
3013 pr_debug("relo for shdr %u, symb %zu, value %zu, type %d, bind %d, name %d (\'%s\'), insn %u\n",
3014 (__u32)sym.st_shndx, (size_t)GELF_R_SYM(rel.r_info),
3015 (size_t)sym.st_value, GELF_ST_TYPE(sym.st_info),
3016 GELF_ST_BIND(sym.st_info), sym.st_name, name,
3019 err = bpf_program__record_reloc(prog, &prog->reloc_desc[i],
3020 insn_idx, name, &sym, &rel);
3027 static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
3029 struct bpf_map_def *def = &map->def;
3030 __u32 key_type_id = 0, value_type_id = 0;
3033 /* if it's BTF-defined map, we don't need to search for type IDs.
3034 * For struct_ops map, it does not need btf_key_type_id and
3035 * btf_value_type_id.
3037 if (map->sec_idx == obj->efile.btf_maps_shndx ||
3038 bpf_map__is_struct_ops(map))
3041 if (!bpf_map__is_internal(map)) {
3042 ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size,
3043 def->value_size, &key_type_id,
3047 * LLVM annotates global data differently in BTF, that is,
3048 * only as '.data', '.bss' or '.rodata'.
3050 ret = btf__find_by_name(obj->btf,
3051 libbpf_type_to_btf_name[map->libbpf_type]);
3056 map->btf_key_type_id = key_type_id;
3057 map->btf_value_type_id = bpf_map__is_internal(map) ?
3058 ret : value_type_id;
3062 int bpf_map__reuse_fd(struct bpf_map *map, int fd)
3064 struct bpf_map_info info = {};
3065 __u32 len = sizeof(info);
3069 err = bpf_obj_get_info_by_fd(fd, &info, &len);
3073 new_name = strdup(info.name);
3077 new_fd = open("/", O_RDONLY | O_CLOEXEC);
3080 goto err_free_new_name;
3083 new_fd = dup3(fd, new_fd, O_CLOEXEC);
3086 goto err_close_new_fd;
3089 err = zclose(map->fd);
3092 goto err_close_new_fd;
3097 map->name = new_name;
3098 map->def.type = info.type;
3099 map->def.key_size = info.key_size;
3100 map->def.value_size = info.value_size;
3101 map->def.max_entries = info.max_entries;
3102 map->def.map_flags = info.map_flags;
3103 map->btf_key_type_id = info.btf_key_type_id;
3104 map->btf_value_type_id = info.btf_value_type_id;
3116 int bpf_map__resize(struct bpf_map *map, __u32 max_entries)
3118 if (!map || !max_entries)
3121 /* If map already created, its attributes can't be changed. */
3125 map->def.max_entries = max_entries;
3131 bpf_object__probe_name(struct bpf_object *obj)
3133 struct bpf_load_program_attr attr;
3134 char *cp, errmsg[STRERR_BUFSIZE];
3135 struct bpf_insn insns[] = {
3136 BPF_MOV64_IMM(BPF_REG_0, 0),
3141 /* make sure basic loading works */
3143 memset(&attr, 0, sizeof(attr));
3144 attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
3146 attr.insns_cnt = ARRAY_SIZE(insns);
3147 attr.license = "GPL";
3149 ret = bpf_load_program_xattr(&attr, NULL, 0);
3151 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
3152 pr_warn("Error in %s():%s(%d). Couldn't load basic 'r0 = 0' BPF program.\n",
3153 __func__, cp, errno);
3158 /* now try the same program, but with the name */
3161 ret = bpf_load_program_xattr(&attr, NULL, 0);
3171 bpf_object__probe_global_data(struct bpf_object *obj)
3173 struct bpf_load_program_attr prg_attr;
3174 struct bpf_create_map_attr map_attr;
3175 char *cp, errmsg[STRERR_BUFSIZE];
3176 struct bpf_insn insns[] = {
3177 BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16),
3178 BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42),
3179 BPF_MOV64_IMM(BPF_REG_0, 0),
3184 memset(&map_attr, 0, sizeof(map_attr));
3185 map_attr.map_type = BPF_MAP_TYPE_ARRAY;
3186 map_attr.key_size = sizeof(int);
3187 map_attr.value_size = 32;
3188 map_attr.max_entries = 1;
3190 map = bpf_create_map_xattr(&map_attr);
3192 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
3193 pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",
3194 __func__, cp, errno);
3200 memset(&prg_attr, 0, sizeof(prg_attr));
3201 prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
3202 prg_attr.insns = insns;
3203 prg_attr.insns_cnt = ARRAY_SIZE(insns);
3204 prg_attr.license = "GPL";
3206 ret = bpf_load_program_xattr(&prg_attr, NULL, 0);
3208 obj->caps.global_data = 1;
3216 static int bpf_object__probe_btf_func(struct bpf_object *obj)
3218 static const char strs[] = "\0int\0x\0a";
3219 /* void x(int a) {} */
3222 BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
3223 /* FUNC_PROTO */ /* [2] */
3224 BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
3225 BTF_PARAM_ENC(7, 1),
3226 /* FUNC x */ /* [3] */
3227 BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2),
3231 btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
3232 strs, sizeof(strs));
3234 obj->caps.btf_func = 1;
3242 static int bpf_object__probe_btf_func_global(struct bpf_object *obj)
3244 static const char strs[] = "\0int\0x\0a";
3245 /* static void x(int a) {} */
3248 BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
3249 /* FUNC_PROTO */ /* [2] */
3250 BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
3251 BTF_PARAM_ENC(7, 1),
3252 /* FUNC x BTF_FUNC_GLOBAL */ /* [3] */
3253 BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, BTF_FUNC_GLOBAL), 2),
3257 btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
3258 strs, sizeof(strs));
3260 obj->caps.btf_func_global = 1;
3268 static int bpf_object__probe_btf_datasec(struct bpf_object *obj)
3270 static const char strs[] = "\0x\0.data";
3274 BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
3275 /* VAR x */ /* [2] */
3276 BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
3278 /* DATASEC val */ /* [3] */
3279 BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
3280 BTF_VAR_SECINFO_ENC(2, 0, 4),
3284 btf_fd = libbpf__load_raw_btf((char *)types, sizeof(types),
3285 strs, sizeof(strs));
3287 obj->caps.btf_datasec = 1;
3295 static int bpf_object__probe_array_mmap(struct bpf_object *obj)
3297 struct bpf_create_map_attr attr = {
3298 .map_type = BPF_MAP_TYPE_ARRAY,
3299 .map_flags = BPF_F_MMAPABLE,
3300 .key_size = sizeof(int),
3301 .value_size = sizeof(int),
3306 fd = bpf_create_map_xattr(&attr);
3308 obj->caps.array_mmap = 1;
3317 bpf_object__probe_caps(struct bpf_object *obj)
3319 int (*probe_fn[])(struct bpf_object *obj) = {
3320 bpf_object__probe_name,
3321 bpf_object__probe_global_data,
3322 bpf_object__probe_btf_func,
3323 bpf_object__probe_btf_func_global,
3324 bpf_object__probe_btf_datasec,
3325 bpf_object__probe_array_mmap,
3329 for (i = 0; i < ARRAY_SIZE(probe_fn); i++) {
3330 ret = probe_fn[i](obj);
3332 pr_debug("Probe #%d failed with %d.\n", i, ret);
3338 static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
3340 struct bpf_map_info map_info = {};
3341 char msg[STRERR_BUFSIZE];
3344 map_info_len = sizeof(map_info);
3346 if (bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len)) {
3347 pr_warn("failed to get map info for map FD %d: %s\n",
3348 map_fd, libbpf_strerror_r(errno, msg, sizeof(msg)));
3352 return (map_info.type == map->def.type &&
3353 map_info.key_size == map->def.key_size &&
3354 map_info.value_size == map->def.value_size &&
3355 map_info.max_entries == map->def.max_entries &&
3356 map_info.map_flags == map->def.map_flags);
3360 bpf_object__reuse_map(struct bpf_map *map)
3362 char *cp, errmsg[STRERR_BUFSIZE];
3365 pin_fd = bpf_obj_get(map->pin_path);
3368 if (err == -ENOENT) {
3369 pr_debug("found no pinned map to reuse at '%s'\n",
3374 cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
3375 pr_warn("couldn't retrieve pinned map '%s': %s\n",
3380 if (!map_is_reuse_compat(map, pin_fd)) {
3381 pr_warn("couldn't reuse pinned map at '%s': parameter mismatch\n",
3387 err = bpf_map__reuse_fd(map, pin_fd);
3393 pr_debug("reused pinned map at '%s'\n", map->pin_path);
3399 bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
3401 enum libbpf_map_type map_type = map->libbpf_type;
3402 char *cp, errmsg[STRERR_BUFSIZE];
3405 /* kernel already zero-initializes .bss map. */
3406 if (map_type == LIBBPF_MAP_BSS)
3409 err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0);
3412 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
3413 pr_warn("Error setting initial map(%s) contents: %s\n",
3418 /* Freeze .rodata and .kconfig map as read-only from syscall side. */
3419 if (map_type == LIBBPF_MAP_RODATA || map_type == LIBBPF_MAP_KCONFIG) {
3420 err = bpf_map_freeze(map->fd);
3423 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
3424 pr_warn("Error freezing map(%s) as read-only: %s\n",
3433 bpf_object__create_maps(struct bpf_object *obj)
3435 struct bpf_create_map_attr create_attr = {};
3440 for (i = 0; i < obj->nr_maps; i++) {
3441 struct bpf_map *map = &obj->maps[i];
3442 struct bpf_map_def *def = &map->def;
3443 char *cp, errmsg[STRERR_BUFSIZE];
3444 int *pfd = &map->fd;
3446 if (map->pin_path) {
3447 err = bpf_object__reuse_map(map);
3449 pr_warn("error reusing pinned map %s\n",
3456 pr_debug("skip map create (preset) %s: fd=%d\n",
3457 map->name, map->fd);
3462 create_attr.name = map->name;
3463 create_attr.map_ifindex = map->map_ifindex;
3464 create_attr.map_type = def->type;
3465 create_attr.map_flags = def->map_flags;
3466 create_attr.key_size = def->key_size;
3467 create_attr.value_size = def->value_size;
3468 if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY &&
3469 !def->max_entries) {
3471 nr_cpus = libbpf_num_possible_cpus();
3473 pr_warn("failed to determine number of system CPUs: %d\n",
3478 pr_debug("map '%s': setting size to %d\n",
3479 map->name, nr_cpus);
3480 create_attr.max_entries = nr_cpus;
3482 create_attr.max_entries = def->max_entries;
3484 create_attr.btf_fd = 0;
3485 create_attr.btf_key_type_id = 0;
3486 create_attr.btf_value_type_id = 0;
3487 if (bpf_map_type__is_map_in_map(def->type) &&
3488 map->inner_map_fd >= 0)
3489 create_attr.inner_map_fd = map->inner_map_fd;
3490 if (bpf_map__is_struct_ops(map))
3491 create_attr.btf_vmlinux_value_type_id =
3492 map->btf_vmlinux_value_type_id;
3494 if (obj->btf && !bpf_map_find_btf_info(obj, map)) {
3495 create_attr.btf_fd = btf__fd(obj->btf);
3496 create_attr.btf_key_type_id = map->btf_key_type_id;
3497 create_attr.btf_value_type_id = map->btf_value_type_id;
3500 *pfd = bpf_create_map_xattr(&create_attr);
3501 if (*pfd < 0 && (create_attr.btf_key_type_id ||
3502 create_attr.btf_value_type_id)) {
3504 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
3505 pr_warn("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",
3506 map->name, cp, err);
3507 create_attr.btf_fd = 0;
3508 create_attr.btf_key_type_id = 0;
3509 create_attr.btf_value_type_id = 0;
3510 map->btf_key_type_id = 0;
3511 map->btf_value_type_id = 0;
3512 *pfd = bpf_create_map_xattr(&create_attr);
3520 cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
3521 pr_warn("failed to create map (name: '%s'): %s(%d)\n",
3522 map->name, cp, err);
3524 for (j = 0; j < i; j++)
3525 zclose(obj->maps[j].fd);
3529 if (bpf_map__is_internal(map)) {
3530 err = bpf_object__populate_internal_map(obj, map);
3537 if (map->pin_path && !map->pinned) {
3538 err = bpf_map__pin(map, NULL);
3540 pr_warn("failed to auto-pin map name '%s' at '%s'\n",
3541 map->name, map->pin_path);
3546 pr_debug("created map %s: fd=%d\n", map->name, *pfd);
3553 check_btf_ext_reloc_err(struct bpf_program *prog, int err,
3554 void *btf_prog_info, const char *info_name)
3556 if (err != -ENOENT) {
3557 pr_warn("Error in loading %s for sec %s.\n",
3558 info_name, prog->section_name);
3562 /* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */
3564 if (btf_prog_info) {
3566 * Some info has already been found but has problem
3567 * in the last btf_ext reloc. Must have to error out.
3569 pr_warn("Error in relocating %s for sec %s.\n",
3570 info_name, prog->section_name);
3574 /* Have problem loading the very first info. Ignore the rest. */
3575 pr_warn("Cannot find %s for main program sec %s. Ignore all %s.\n",
3576 info_name, prog->section_name, info_name);
3581 bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj,
3582 const char *section_name, __u32 insn_offset)
3586 if (!insn_offset || prog->func_info) {
3588 * !insn_offset => main program
3590 * For sub prog, the main program's func_info has to
3591 * be loaded first (i.e. prog->func_info != NULL)
3593 err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext,
3594 section_name, insn_offset,
3596 &prog->func_info_cnt);
3598 return check_btf_ext_reloc_err(prog, err,
3602 prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext);
3605 if (!insn_offset || prog->line_info) {
3606 err = btf_ext__reloc_line_info(obj->btf, obj->btf_ext,
3607 section_name, insn_offset,
3609 &prog->line_info_cnt);
3611 return check_btf_ext_reloc_err(prog, err,
3615 prog->line_info_rec_size = btf_ext__line_info_rec_size(obj->btf_ext);
3621 #define BPF_CORE_SPEC_MAX_LEN 64
3623 /* represents BPF CO-RE field or array element accessor */
3624 struct bpf_core_accessor {
3625 __u32 type_id; /* struct/union type or array element type */
3626 __u32 idx; /* field index or array index */
3627 const char *name; /* field name or NULL for array accessor */
3630 struct bpf_core_spec {
3631 const struct btf *btf;
3632 /* high-level spec: named fields and array indices only */
3633 struct bpf_core_accessor spec[BPF_CORE_SPEC_MAX_LEN];
3634 /* high-level spec length */
3636 /* raw, low-level spec: 1-to-1 with accessor spec string */
3637 int raw_spec[BPF_CORE_SPEC_MAX_LEN];
3638 /* raw spec length */
3640 /* field bit offset represented by spec */
3644 static bool str_is_empty(const char *s)
3649 static bool is_flex_arr(const struct btf *btf,
3650 const struct bpf_core_accessor *acc,
3651 const struct btf_array *arr)
3653 const struct btf_type *t;
3655 /* not a flexible array, if not inside a struct or has non-zero size */
3656 if (!acc->name || arr->nelems > 0)
3659 /* has to be the last member of enclosing struct */
3660 t = btf__type_by_id(btf, acc->type_id);
3661 return acc->idx == btf_vlen(t) - 1;
3665 * Turn bpf_field_reloc into a low- and high-level spec representation,
3666 * validating correctness along the way, as well as calculating resulting
3667 * field bit offset, specified by accessor string. Low-level spec captures
3668 * every single level of nestedness, including traversing anonymous
3669 * struct/union members. High-level one only captures semantically meaningful
3670 * "turning points": named fields and array indicies.
3671 * E.g., for this case:
3674 * int __unimportant;
3682 * struct sample *s = ...;
3684 * int x = &s->a[3]; // access string = '0:1:2:3'
3686 * Low-level spec has 1:1 mapping with each element of access string (it's
3687 * just a parsed access string representation): [0, 1, 2, 3].
3689 * High-level spec will capture only 3 points:
3690 * - intial zero-index access by pointer (&s->... is the same as &s[0]...);
3691 * - field 'a' access (corresponds to '2' in low-level spec);
3692 * - array element #3 access (corresponds to '3' in low-level spec).
3695 static int bpf_core_spec_parse(const struct btf *btf,
3697 const char *spec_str,
3698 struct bpf_core_spec *spec)
3700 int access_idx, parsed_len, i;
3701 struct bpf_core_accessor *acc;
3702 const struct btf_type *t;
3707 if (str_is_empty(spec_str) || *spec_str == ':')
3710 memset(spec, 0, sizeof(*spec));
3713 /* parse spec_str="0:1:2:3:4" into array raw_spec=[0, 1, 2, 3, 4] */
3715 if (*spec_str == ':')
3717 if (sscanf(spec_str, "%d%n", &access_idx, &parsed_len) != 1)
3719 if (spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
3721 spec_str += parsed_len;
3722 spec->raw_spec[spec->raw_len++] = access_idx;
3725 if (spec->raw_len == 0)
3728 /* first spec value is always reloc type array index */
3729 t = skip_mods_and_typedefs(btf, type_id, &id);
3733 access_idx = spec->raw_spec[0];
3734 spec->spec[0].type_id = id;
3735 spec->spec[0].idx = access_idx;
3738 sz = btf__resolve_size(btf, id);
3741 spec->bit_offset = access_idx * sz * 8;
3743 for (i = 1; i < spec->raw_len; i++) {
3744 t = skip_mods_and_typedefs(btf, id, &id);
3748 access_idx = spec->raw_spec[i];
3749 acc = &spec->spec[spec->len];
3751 if (btf_is_composite(t)) {
3752 const struct btf_member *m;
3755 if (access_idx >= btf_vlen(t))
3758 bit_offset = btf_member_bit_offset(t, access_idx);
3759 spec->bit_offset += bit_offset;
3761 m = btf_members(t) + access_idx;
3763 name = btf__name_by_offset(btf, m->name_off);
3764 if (str_is_empty(name))
3768 acc->idx = access_idx;
3774 } else if (btf_is_array(t)) {
3775 const struct btf_array *a = btf_array(t);
3778 t = skip_mods_and_typedefs(btf, a->type, &id);
3782 flex = is_flex_arr(btf, acc - 1, a);
3783 if (!flex && access_idx >= a->nelems)
3786 spec->spec[spec->len].type_id = id;
3787 spec->spec[spec->len].idx = access_idx;
3790 sz = btf__resolve_size(btf, id);
3793 spec->bit_offset += access_idx * sz * 8;
3795 pr_warn("relo for [%u] %s (at idx %d) captures type [%d] of unexpected kind %d\n",
3796 type_id, spec_str, i, id, btf_kind(t));
3804 static bool bpf_core_is_flavor_sep(const char *s)
3806 /* check X___Y name pattern, where X and Y are not underscores */
3807 return s[0] != '_' && /* X */
3808 s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */
3809 s[4] != '_'; /* Y */
3812 /* Given 'some_struct_name___with_flavor' return the length of a name prefix
3813 * before last triple underscore. Struct name part after last triple
3814 * underscore is ignored by BPF CO-RE relocation during relocation matching.
3816 static size_t bpf_core_essential_name_len(const char *name)
3818 size_t n = strlen(name);
3821 for (i = n - 5; i >= 0; i--) {
3822 if (bpf_core_is_flavor_sep(name + i))
3828 /* dynamically sized list of type IDs */
3834 static void bpf_core_free_cands(struct ids_vec *cand_ids)
3836 free(cand_ids->data);
3840 static struct ids_vec *bpf_core_find_cands(const struct btf *local_btf,
3841 __u32 local_type_id,
3842 const struct btf *targ_btf)
3844 size_t local_essent_len, targ_essent_len;
3845 const char *local_name, *targ_name;
3846 const struct btf_type *t;
3847 struct ids_vec *cand_ids;
3851 t = btf__type_by_id(local_btf, local_type_id);
3853 return ERR_PTR(-EINVAL);
3855 local_name = btf__name_by_offset(local_btf, t->name_off);
3856 if (str_is_empty(local_name))
3857 return ERR_PTR(-EINVAL);
3858 local_essent_len = bpf_core_essential_name_len(local_name);
3860 cand_ids = calloc(1, sizeof(*cand_ids));
3862 return ERR_PTR(-ENOMEM);
3864 n = btf__get_nr_types(targ_btf);
3865 for (i = 1; i <= n; i++) {
3866 t = btf__type_by_id(targ_btf, i);
3867 targ_name = btf__name_by_offset(targ_btf, t->name_off);
3868 if (str_is_empty(targ_name))
3871 targ_essent_len = bpf_core_essential_name_len(targ_name);
3872 if (targ_essent_len != local_essent_len)
3875 if (strncmp(local_name, targ_name, local_essent_len) == 0) {
3876 pr_debug("[%d] %s: found candidate [%d] %s\n",
3877 local_type_id, local_name, i, targ_name);
3878 new_ids = reallocarray(cand_ids->data,
3880 sizeof(*cand_ids->data));
3885 cand_ids->data = new_ids;
3886 cand_ids->data[cand_ids->len++] = i;
3891 bpf_core_free_cands(cand_ids);
3892 return ERR_PTR(err);
3895 /* Check two types for compatibility, skipping const/volatile/restrict and
3896 * typedefs, to ensure we are relocating compatible entities:
3897 * - any two STRUCTs/UNIONs are compatible and can be mixed;
3898 * - any two FWDs are compatible, if their names match (modulo flavor suffix);
3899 * - any two PTRs are always compatible;
3900 * - for ENUMs, names should be the same (ignoring flavor suffix) or at
3901 * least one of enums should be anonymous;
3902 * - for ENUMs, check sizes, names are ignored;
3903 * - for INT, size and signedness are ignored;
3904 * - for ARRAY, dimensionality is ignored, element types are checked for
3905 * compatibility recursively;
3906 * - everything else shouldn't be ever a target of relocation.
3907 * These rules are not set in stone and probably will be adjusted as we get
3908 * more experience with using BPF CO-RE relocations.
3910 static int bpf_core_fields_are_compat(const struct btf *local_btf,
3912 const struct btf *targ_btf,
3915 const struct btf_type *local_type, *targ_type;
3918 local_type = skip_mods_and_typedefs(local_btf, local_id, &local_id);
3919 targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
3920 if (!local_type || !targ_type)
3923 if (btf_is_composite(local_type) && btf_is_composite(targ_type))
3925 if (btf_kind(local_type) != btf_kind(targ_type))
3928 switch (btf_kind(local_type)) {
3932 case BTF_KIND_ENUM: {
3933 const char *local_name, *targ_name;
3934 size_t local_len, targ_len;
3936 local_name = btf__name_by_offset(local_btf,
3937 local_type->name_off);
3938 targ_name = btf__name_by_offset(targ_btf, targ_type->name_off);
3939 local_len = bpf_core_essential_name_len(local_name);
3940 targ_len = bpf_core_essential_name_len(targ_name);
3941 /* one of them is anonymous or both w/ same flavor-less names */
3942 return local_len == 0 || targ_len == 0 ||
3943 (local_len == targ_len &&
3944 strncmp(local_name, targ_name, local_len) == 0);
3947 /* just reject deprecated bitfield-like integers; all other
3948 * integers are by default compatible between each other
3950 return btf_int_offset(local_type) == 0 &&
3951 btf_int_offset(targ_type) == 0;
3952 case BTF_KIND_ARRAY:
3953 local_id = btf_array(local_type)->type;
3954 targ_id = btf_array(targ_type)->type;
3957 pr_warn("unexpected kind %d relocated, local [%d], target [%d]\n",
3958 btf_kind(local_type), local_id, targ_id);
3964 * Given single high-level named field accessor in local type, find
3965 * corresponding high-level accessor for a target type. Along the way,
3966 * maintain low-level spec for target as well. Also keep updating target
3969 * Searching is performed through recursive exhaustive enumeration of all
3970 * fields of a struct/union. If there are any anonymous (embedded)
3971 * structs/unions, they are recursively searched as well. If field with
3972 * desired name is found, check compatibility between local and target types,
3973 * before returning result.
3975 * 1 is returned, if field is found.
3976 * 0 is returned if no compatible field is found.
3977 * <0 is returned on error.
3979 static int bpf_core_match_member(const struct btf *local_btf,
3980 const struct bpf_core_accessor *local_acc,
3981 const struct btf *targ_btf,
3983 struct bpf_core_spec *spec,
3984 __u32 *next_targ_id)
3986 const struct btf_type *local_type, *targ_type;
3987 const struct btf_member *local_member, *m;
3988 const char *local_name, *targ_name;
3992 targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id);
3995 if (!btf_is_composite(targ_type))
3998 local_id = local_acc->type_id;
3999 local_type = btf__type_by_id(local_btf, local_id);
4000 local_member = btf_members(local_type) + local_acc->idx;
4001 local_name = btf__name_by_offset(local_btf, local_member->name_off);
4003 n = btf_vlen(targ_type);
4004 m = btf_members(targ_type);
4005 for (i = 0; i < n; i++, m++) {
4008 bit_offset = btf_member_bit_offset(targ_type, i);
4010 /* too deep struct/union/array nesting */
4011 if (spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
4014 /* speculate this member will be the good one */
4015 spec->bit_offset += bit_offset;
4016 spec->raw_spec[spec->raw_len++] = i;
4018 targ_name = btf__name_by_offset(targ_btf, m->name_off);
4019 if (str_is_empty(targ_name)) {
4020 /* embedded struct/union, we need to go deeper */
4021 found = bpf_core_match_member(local_btf, local_acc,
4023 spec, next_targ_id);
4024 if (found) /* either found or error */
4026 } else if (strcmp(local_name, targ_name) == 0) {
4027 /* matching named field */
4028 struct bpf_core_accessor *targ_acc;
4030 targ_acc = &spec->spec[spec->len++];
4031 targ_acc->type_id = targ_id;
4033 targ_acc->name = targ_name;
4035 *next_targ_id = m->type;
4036 found = bpf_core_fields_are_compat(local_btf,
4040 spec->len--; /* pop accessor */
4043 /* member turned out not to be what we looked for */
4044 spec->bit_offset -= bit_offset;
4052 * Try to match local spec to a target type and, if successful, produce full
4053 * target spec (high-level, low-level + bit offset).
4055 static int bpf_core_spec_match(struct bpf_core_spec *local_spec,
4056 const struct btf *targ_btf, __u32 targ_id,
4057 struct bpf_core_spec *targ_spec)
4059 const struct btf_type *targ_type;
4060 const struct bpf_core_accessor *local_acc;
4061 struct bpf_core_accessor *targ_acc;
4064 memset(targ_spec, 0, sizeof(*targ_spec));
4065 targ_spec->btf = targ_btf;
4067 local_acc = &local_spec->spec[0];
4068 targ_acc = &targ_spec->spec[0];
4070 for (i = 0; i < local_spec->len; i++, local_acc++, targ_acc++) {
4071 targ_type = skip_mods_and_typedefs(targ_spec->btf, targ_id,
4076 if (local_acc->name) {
4077 matched = bpf_core_match_member(local_spec->btf,
4080 targ_spec, &targ_id);
4084 /* for i=0, targ_id is already treated as array element
4085 * type (because it's the original struct), for others
4086 * we should find array element type first
4089 const struct btf_array *a;
4092 if (!btf_is_array(targ_type))
4095 a = btf_array(targ_type);
4096 flex = is_flex_arr(targ_btf, targ_acc - 1, a);
4097 if (!flex && local_acc->idx >= a->nelems)
4099 if (!skip_mods_and_typedefs(targ_btf, a->type,
4104 /* too deep struct/union/array nesting */
4105 if (targ_spec->raw_len == BPF_CORE_SPEC_MAX_LEN)
4108 targ_acc->type_id = targ_id;
4109 targ_acc->idx = local_acc->idx;
4110 targ_acc->name = NULL;
4112 targ_spec->raw_spec[targ_spec->raw_len] = targ_acc->idx;
4113 targ_spec->raw_len++;
4115 sz = btf__resolve_size(targ_btf, targ_id);
4118 targ_spec->bit_offset += local_acc->idx * sz * 8;
4125 static int bpf_core_calc_field_relo(const struct bpf_program *prog,
4126 const struct bpf_field_reloc *relo,
4127 const struct bpf_core_spec *spec,
4128 __u32 *val, bool *validate)
4130 const struct bpf_core_accessor *acc = &spec->spec[spec->len - 1];
4131 const struct btf_type *t = btf__type_by_id(spec->btf, acc->type_id);
4132 __u32 byte_off, byte_sz, bit_off, bit_sz;
4133 const struct btf_member *m;
4134 const struct btf_type *mt;
4138 /* a[n] accessor needs special handling */
4140 if (relo->kind == BPF_FIELD_BYTE_OFFSET) {
4141 *val = spec->bit_offset / 8;
4142 } else if (relo->kind == BPF_FIELD_BYTE_SIZE) {
4143 sz = btf__resolve_size(spec->btf, acc->type_id);
4148 pr_warn("prog '%s': relo %d at insn #%d can't be applied to array access\n",
4149 bpf_program__title(prog, false),
4150 relo->kind, relo->insn_off / 8);
4158 m = btf_members(t) + acc->idx;
4159 mt = skip_mods_and_typedefs(spec->btf, m->type, NULL);
4160 bit_off = spec->bit_offset;
4161 bit_sz = btf_member_bitfield_size(t, acc->idx);
4163 bitfield = bit_sz > 0;
4166 byte_off = bit_off / 8 / byte_sz * byte_sz;
4167 /* figure out smallest int size necessary for bitfield load */
4168 while (bit_off + bit_sz - byte_off * 8 > byte_sz * 8) {
4170 /* bitfield can't be read with 64-bit read */
4171 pr_warn("prog '%s': relo %d at insn #%d can't be satisfied for bitfield\n",
4172 bpf_program__title(prog, false),
4173 relo->kind, relo->insn_off / 8);
4177 byte_off = bit_off / 8 / byte_sz * byte_sz;
4180 sz = btf__resolve_size(spec->btf, m->type);
4184 byte_off = spec->bit_offset / 8;
4185 bit_sz = byte_sz * 8;
4188 /* for bitfields, all the relocatable aspects are ambiguous and we
4189 * might disagree with compiler, so turn off validation of expected
4190 * value, except for signedness
4193 *validate = !bitfield;
4195 switch (relo->kind) {
4196 case BPF_FIELD_BYTE_OFFSET:
4199 case BPF_FIELD_BYTE_SIZE:
4202 case BPF_FIELD_SIGNED:
4203 /* enums will be assumed unsigned */
4204 *val = btf_is_enum(mt) ||
4205 (btf_int_encoding(mt) & BTF_INT_SIGNED);
4207 *validate = true; /* signedness is never ambiguous */
4209 case BPF_FIELD_LSHIFT_U64:
4210 #if __BYTE_ORDER == __LITTLE_ENDIAN
4211 *val = 64 - (bit_off + bit_sz - byte_off * 8);
4213 *val = (8 - byte_sz) * 8 + (bit_off - byte_off * 8);
4216 case BPF_FIELD_RSHIFT_U64:
4219 *validate = true; /* right shift is never ambiguous */
4221 case BPF_FIELD_EXISTS:
4223 pr_warn("prog '%s': unknown relo %d at insn #%d\n",
4224 bpf_program__title(prog, false),
4225 relo->kind, relo->insn_off / 8);
4233 * Patch relocatable BPF instruction.
4235 * Patched value is determined by relocation kind and target specification.
4236 * For field existence relocation target spec will be NULL if field is not
4238 * Expected insn->imm value is determined using relocation kind and local
4239 * spec, and is checked before patching instruction. If actual insn->imm value
4240 * is wrong, bail out with error.
4242 * Currently three kinds of BPF instructions are supported:
4243 * 1. rX = <imm> (assignment with immediate operand);
4244 * 2. rX += <imm> (arithmetic operations with immediate operand);
4246 static int bpf_core_reloc_insn(struct bpf_program *prog,
4247 const struct bpf_field_reloc *relo,
4249 const struct bpf_core_spec *local_spec,
4250 const struct bpf_core_spec *targ_spec)
4252 __u32 orig_val, new_val;
4253 struct bpf_insn *insn;
4254 bool validate = true;
4258 if (relo->insn_off % sizeof(struct bpf_insn))
4260 insn_idx = relo->insn_off / sizeof(struct bpf_insn);
4261 insn = &prog->insns[insn_idx];
4262 class = BPF_CLASS(insn->code);
4264 if (relo->kind == BPF_FIELD_EXISTS) {
4265 orig_val = 1; /* can't generate EXISTS relo w/o local field */
4266 new_val = targ_spec ? 1 : 0;
4267 } else if (!targ_spec) {
4268 pr_debug("prog '%s': relo #%d: substituting insn #%d w/ invalid insn\n",
4269 bpf_program__title(prog, false), relo_idx, insn_idx);
4270 insn->code = BPF_JMP | BPF_CALL;
4274 /* if this instruction is reachable (not a dead code),
4275 * verifier will complain with the following message:
4276 * invalid func unknown#195896080
4278 insn->imm = 195896080; /* => 0xbad2310 => "bad relo" */
4281 err = bpf_core_calc_field_relo(prog, relo, local_spec,
4282 &orig_val, &validate);
4285 err = bpf_core_calc_field_relo(prog, relo, targ_spec,
4294 if (BPF_SRC(insn->code) != BPF_K)
4296 if (validate && insn->imm != orig_val) {
4297 pr_warn("prog '%s': relo #%d: unexpected insn #%d (ALU/ALU64) value: got %u, exp %u -> %u\n",
4298 bpf_program__title(prog, false), relo_idx,
4299 insn_idx, insn->imm, orig_val, new_val);
4302 orig_val = insn->imm;
4303 insn->imm = new_val;
4304 pr_debug("prog '%s': relo #%d: patched insn #%d (ALU/ALU64) imm %u -> %u\n",
4305 bpf_program__title(prog, false), relo_idx, insn_idx,
4311 if (validate && insn->off != orig_val) {
4312 pr_warn("prog '%s': relo #%d: unexpected insn #%d (LD/LDX/ST/STX) value: got %u, exp %u -> %u\n",
4313 bpf_program__title(prog, false), relo_idx,
4314 insn_idx, insn->off, orig_val, new_val);
4317 if (new_val > SHRT_MAX) {
4318 pr_warn("prog '%s': relo #%d: insn #%d (LDX/ST/STX) value too big: %u\n",
4319 bpf_program__title(prog, false), relo_idx,
4323 orig_val = insn->off;
4324 insn->off = new_val;
4325 pr_debug("prog '%s': relo #%d: patched insn #%d (LDX/ST/STX) off %u -> %u\n",
4326 bpf_program__title(prog, false), relo_idx, insn_idx,
4330 pr_warn("prog '%s': relo #%d: trying to relocate unrecognized insn #%d, code:%x, src:%x, dst:%x, off:%x, imm:%x\n",
4331 bpf_program__title(prog, false), relo_idx,
4332 insn_idx, insn->code, insn->src_reg, insn->dst_reg,
4333 insn->off, insn->imm);
4340 /* Output spec definition in the format:
4341 * [<type-id>] (<type-name>) + <raw-spec> => <offset>@<spec>,
4342 * where <spec> is a C-syntax view of recorded field access, e.g.: x.a[3].b
4344 static void bpf_core_dump_spec(int level, const struct bpf_core_spec *spec)
4346 const struct btf_type *t;
4351 type_id = spec->spec[0].type_id;
4352 t = btf__type_by_id(spec->btf, type_id);
4353 s = btf__name_by_offset(spec->btf, t->name_off);
4354 libbpf_print(level, "[%u] %s + ", type_id, s);
4356 for (i = 0; i < spec->raw_len; i++)
4357 libbpf_print(level, "%d%s", spec->raw_spec[i],
4358 i == spec->raw_len - 1 ? " => " : ":");
4360 libbpf_print(level, "%u.%u @ &x",
4361 spec->bit_offset / 8, spec->bit_offset % 8);
4363 for (i = 0; i < spec->len; i++) {
4364 if (spec->spec[i].name)
4365 libbpf_print(level, ".%s", spec->spec[i].name);
4367 libbpf_print(level, "[%u]", spec->spec[i].idx);
4372 static size_t bpf_core_hash_fn(const void *key, void *ctx)
4377 static bool bpf_core_equal_fn(const void *k1, const void *k2, void *ctx)
4382 static void *u32_as_hash_key(__u32 x)
4384 return (void *)(uintptr_t)x;
4388 * CO-RE relocate single instruction.
4390 * The outline and important points of the algorithm:
4391 * 1. For given local type, find corresponding candidate target types.
4392 * Candidate type is a type with the same "essential" name, ignoring
4393 * everything after last triple underscore (___). E.g., `sample`,
4394 * `sample___flavor_one`, `sample___flavor_another_one`, are all candidates
4395 * for each other. Names with triple underscore are referred to as
4396 * "flavors" and are useful, among other things, to allow to
4397 * specify/support incompatible variations of the same kernel struct, which
4398 * might differ between different kernel versions and/or build
4401 * N.B. Struct "flavors" could be generated by bpftool's BTF-to-C
4402 * converter, when deduplicated BTF of a kernel still contains more than
4403 * one different types with the same name. In that case, ___2, ___3, etc
4404 * are appended starting from second name conflict. But start flavors are
4405 * also useful to be defined "locally", in BPF program, to extract same
4406 * data from incompatible changes between different kernel
4407 * versions/configurations. For instance, to handle field renames between
4408 * kernel versions, one can use two flavors of the struct name with the
4409 * same common name and use conditional relocations to extract that field,
4410 * depending on target kernel version.
4411 * 2. For each candidate type, try to match local specification to this
4412 * candidate target type. Matching involves finding corresponding
4413 * high-level spec accessors, meaning that all named fields should match,
4414 * as well as all array accesses should be within the actual bounds. Also,
4415 * types should be compatible (see bpf_core_fields_are_compat for details).
4416 * 3. It is supported and expected that there might be multiple flavors
4417 * matching the spec. As long as all the specs resolve to the same set of
4418 * offsets across all candidates, there is no error. If there is any
4419 * ambiguity, CO-RE relocation will fail. This is necessary to accomodate
4420 * imprefection of BTF deduplication, which can cause slight duplication of
4421 * the same BTF type, if some directly or indirectly referenced (by
4422 * pointer) type gets resolved to different actual types in different
4423 * object files. If such situation occurs, deduplicated BTF will end up
4424 * with two (or more) structurally identical types, which differ only in
4425 * types they refer to through pointer. This should be OK in most cases and
4427 * 4. Candidate types search is performed by linearly scanning through all
4428 * types in target BTF. It is anticipated that this is overall more
4429 * efficient memory-wise and not significantly worse (if not better)
4430 * CPU-wise compared to prebuilding a map from all local type names to
4431 * a list of candidate type names. It's also sped up by caching resolved
4432 * list of matching candidates per each local "root" type ID, that has at
4433 * least one bpf_field_reloc associated with it. This list is shared
4434 * between multiple relocations for the same type ID and is updated as some
4435 * of the candidates are pruned due to structural incompatibility.
4437 static int bpf_core_reloc_field(struct bpf_program *prog,
4438 const struct bpf_field_reloc *relo,
4440 const struct btf *local_btf,
4441 const struct btf *targ_btf,
4442 struct hashmap *cand_cache)
4444 const char *prog_name = bpf_program__title(prog, false);
4445 struct bpf_core_spec local_spec, cand_spec, targ_spec;
4446 const void *type_key = u32_as_hash_key(relo->type_id);
4447 const struct btf_type *local_type, *cand_type;
4448 const char *local_name, *cand_name;
4449 struct ids_vec *cand_ids;
4450 __u32 local_id, cand_id;
4451 const char *spec_str;
4454 local_id = relo->type_id;
4455 local_type = btf__type_by_id(local_btf, local_id);
4459 local_name = btf__name_by_offset(local_btf, local_type->name_off);
4460 if (str_is_empty(local_name))
4463 spec_str = btf__name_by_offset(local_btf, relo->access_str_off);
4464 if (str_is_empty(spec_str))
4467 err = bpf_core_spec_parse(local_btf, local_id, spec_str, &local_spec);
4469 pr_warn("prog '%s': relo #%d: parsing [%d] %s + %s failed: %d\n",
4470 prog_name, relo_idx, local_id, local_name, spec_str,
4475 pr_debug("prog '%s': relo #%d: kind %d, spec is ", prog_name, relo_idx,
4477 bpf_core_dump_spec(LIBBPF_DEBUG, &local_spec);
4478 libbpf_print(LIBBPF_DEBUG, "\n");
4480 if (!hashmap__find(cand_cache, type_key, (void **)&cand_ids)) {
4481 cand_ids = bpf_core_find_cands(local_btf, local_id, targ_btf);
4482 if (IS_ERR(cand_ids)) {
4483 pr_warn("prog '%s': relo #%d: target candidate search failed for [%d] %s: %ld",
4484 prog_name, relo_idx, local_id, local_name,
4486 return PTR_ERR(cand_ids);
4488 err = hashmap__set(cand_cache, type_key, cand_ids, NULL, NULL);
4490 bpf_core_free_cands(cand_ids);
4495 for (i = 0, j = 0; i < cand_ids->len; i++) {
4496 cand_id = cand_ids->data[i];
4497 cand_type = btf__type_by_id(targ_btf, cand_id);
4498 cand_name = btf__name_by_offset(targ_btf, cand_type->name_off);
4500 err = bpf_core_spec_match(&local_spec, targ_btf,
4501 cand_id, &cand_spec);
4502 pr_debug("prog '%s': relo #%d: matching candidate #%d %s against spec ",
4503 prog_name, relo_idx, i, cand_name);
4504 bpf_core_dump_spec(LIBBPF_DEBUG, &cand_spec);
4505 libbpf_print(LIBBPF_DEBUG, ": %d\n", err);
4507 pr_warn("prog '%s': relo #%d: matching error: %d\n",
4508 prog_name, relo_idx, err);
4515 targ_spec = cand_spec;
4516 } else if (cand_spec.bit_offset != targ_spec.bit_offset) {
4517 /* if there are many candidates, they should all
4518 * resolve to the same bit offset
4520 pr_warn("prog '%s': relo #%d: offset ambiguity: %u != %u\n",
4521 prog_name, relo_idx, cand_spec.bit_offset,
4522 targ_spec.bit_offset);
4526 cand_ids->data[j++] = cand_spec.spec[0].type_id;
4530 * For BPF_FIELD_EXISTS relo or when used BPF program has field
4531 * existence checks or kernel version/config checks, it's expected
4532 * that we might not find any candidates. In this case, if field
4533 * wasn't found in any candidate, the list of candidates shouldn't
4534 * change at all, we'll just handle relocating appropriately,
4535 * depending on relo's kind.
4541 * If no candidates were found, it might be both a programmer error,
4542 * as well as expected case, depending whether instruction w/
4543 * relocation is guarded in some way that makes it unreachable (dead
4544 * code) if relocation can't be resolved. This is handled in
4545 * bpf_core_reloc_insn() uniformly by replacing that instruction with
4546 * BPF helper call insn (using invalid helper ID). If that instruction
4547 * is indeed unreachable, then it will be ignored and eliminated by
4548 * verifier. If it was an error, then verifier will complain and point
4549 * to a specific instruction number in its log.
4552 pr_debug("prog '%s': relo #%d: no matching targets found for [%d] %s + %s\n",
4553 prog_name, relo_idx, local_id, local_name, spec_str);
4555 /* bpf_core_reloc_insn should know how to handle missing targ_spec */
4556 err = bpf_core_reloc_insn(prog, relo, relo_idx, &local_spec,
4557 j ? &targ_spec : NULL);
4559 pr_warn("prog '%s': relo #%d: failed to patch insn at offset %d: %d\n",
4560 prog_name, relo_idx, relo->insn_off, err);
4568 bpf_core_reloc_fields(struct bpf_object *obj, const char *targ_btf_path)
4570 const struct btf_ext_info_sec *sec;
4571 const struct bpf_field_reloc *rec;
4572 const struct btf_ext_info *seg;
4573 struct hashmap_entry *entry;
4574 struct hashmap *cand_cache = NULL;
4575 struct bpf_program *prog;
4576 struct btf *targ_btf;
4577 const char *sec_name;
4581 targ_btf = btf__parse_elf(targ_btf_path, NULL);
4583 targ_btf = libbpf_find_kernel_btf();
4584 if (IS_ERR(targ_btf)) {
4585 pr_warn("failed to get target BTF: %ld\n", PTR_ERR(targ_btf));
4586 return PTR_ERR(targ_btf);
4589 cand_cache = hashmap__new(bpf_core_hash_fn, bpf_core_equal_fn, NULL);
4590 if (IS_ERR(cand_cache)) {
4591 err = PTR_ERR(cand_cache);
4595 seg = &obj->btf_ext->field_reloc_info;
4596 for_each_btf_ext_sec(seg, sec) {
4597 sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off);
4598 if (str_is_empty(sec_name)) {
4602 prog = bpf_object__find_program_by_title(obj, sec_name);
4604 pr_warn("failed to find program '%s' for CO-RE offset relocation\n",
4610 pr_debug("prog '%s': performing %d CO-RE offset relocs\n",
4611 sec_name, sec->num_info);
4613 for_each_btf_ext_rec(seg, sec, i, rec) {
4614 err = bpf_core_reloc_field(prog, rec, i, obj->btf,
4615 targ_btf, cand_cache);
4617 pr_warn("prog '%s': relo #%d: failed to relocate: %d\n",
4625 btf__free(targ_btf);
4626 if (!IS_ERR_OR_NULL(cand_cache)) {
4627 hashmap__for_each_entry(cand_cache, entry, i) {
4628 bpf_core_free_cands(entry->value);
4630 hashmap__free(cand_cache);
4636 bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path)
4640 if (obj->btf_ext->field_reloc_info.len)
4641 err = bpf_core_reloc_fields(obj, targ_btf_path);
4647 bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
4648 struct reloc_desc *relo)
4650 struct bpf_insn *insn, *new_insn;
4651 struct bpf_program *text;
4655 if (prog->idx != obj->efile.text_shndx && prog->main_prog_cnt == 0) {
4656 text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx);
4658 pr_warn("no .text section found yet relo into text exist\n");
4659 return -LIBBPF_ERRNO__RELOC;
4661 new_cnt = prog->insns_cnt + text->insns_cnt;
4662 new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
4664 pr_warn("oom in prog realloc\n");
4667 prog->insns = new_insn;
4670 err = bpf_program_reloc_btf_ext(prog, obj,
4677 memcpy(new_insn + prog->insns_cnt, text->insns,
4678 text->insns_cnt * sizeof(*insn));
4679 prog->main_prog_cnt = prog->insns_cnt;
4680 prog->insns_cnt = new_cnt;
4681 pr_debug("added %zd insn from %s to prog %s\n",
4682 text->insns_cnt, text->section_name,
4683 prog->section_name);
4686 insn = &prog->insns[relo->insn_idx];
4687 insn->imm += relo->sym_off / 8 + prog->main_prog_cnt - relo->insn_idx;
4692 bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
4700 err = bpf_program_reloc_btf_ext(prog, obj,
4701 prog->section_name, 0);
4706 if (!prog->reloc_desc)
4709 for (i = 0; i < prog->nr_reloc; i++) {
4710 struct reloc_desc *relo = &prog->reloc_desc[i];
4711 struct bpf_insn *insn = &prog->insns[relo->insn_idx];
4713 if (relo->insn_idx + 1 >= (int)prog->insns_cnt) {
4714 pr_warn("relocation out of range: '%s'\n",
4715 prog->section_name);
4716 return -LIBBPF_ERRNO__RELOC;
4719 switch (relo->type) {
4721 insn[0].src_reg = BPF_PSEUDO_MAP_FD;
4722 insn[0].imm = obj->maps[relo->map_idx].fd;
4725 insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
4726 insn[1].imm = insn[0].imm + relo->sym_off;
4727 insn[0].imm = obj->maps[relo->map_idx].fd;
4730 insn[0].src_reg = BPF_PSEUDO_MAP_VALUE;
4731 insn[0].imm = obj->maps[obj->kconfig_map_idx].fd;
4732 insn[1].imm = relo->sym_off;
4735 err = bpf_program__reloc_text(prog, obj, relo);
4740 pr_warn("relo #%d: bad relo type %d\n", i, relo->type);
4745 zfree(&prog->reloc_desc);
4751 bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
4753 struct bpf_program *prog;
4758 err = bpf_object__relocate_core(obj, targ_btf_path);
4760 pr_warn("failed to perform CO-RE relocations: %d\n",
4765 /* ensure .text is relocated first, as it's going to be copied as-is
4766 * later for sub-program calls
4768 for (i = 0; i < obj->nr_programs; i++) {
4769 prog = &obj->programs[i];
4770 if (prog->idx != obj->efile.text_shndx)
4773 err = bpf_program__relocate(prog, obj);
4775 pr_warn("failed to relocate '%s'\n", prog->section_name);
4780 /* now relocate everything but .text, which by now is relocated
4781 * properly, so we can copy raw sub-program instructions as is safely
4783 for (i = 0; i < obj->nr_programs; i++) {
4784 prog = &obj->programs[i];
4785 if (prog->idx == obj->efile.text_shndx)
4788 err = bpf_program__relocate(prog, obj);
4790 pr_warn("failed to relocate '%s'\n", prog->section_name);
4797 static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj,
4801 static int bpf_object__collect_reloc(struct bpf_object *obj)
4805 if (!obj_elf_valid(obj)) {
4806 pr_warn("Internal error: elf object is closed\n");
4807 return -LIBBPF_ERRNO__INTERNAL;
4810 for (i = 0; i < obj->efile.nr_reloc_sects; i++) {
4811 GElf_Shdr *shdr = &obj->efile.reloc_sects[i].shdr;
4812 Elf_Data *data = obj->efile.reloc_sects[i].data;
4813 int idx = shdr->sh_info;
4814 struct bpf_program *prog;
4816 if (shdr->sh_type != SHT_REL) {
4817 pr_warn("internal error at %d\n", __LINE__);
4818 return -LIBBPF_ERRNO__INTERNAL;
4821 if (idx == obj->efile.st_ops_shndx) {
4822 err = bpf_object__collect_struct_ops_map_reloc(obj,
4830 prog = bpf_object__find_prog_by_idx(obj, idx);
4832 pr_warn("relocation failed: no section(%d)\n", idx);
4833 return -LIBBPF_ERRNO__RELOC;
4836 err = bpf_program__collect_reloc(prog, shdr, data, obj);
4844 load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
4845 char *license, __u32 kern_version, int *pfd)
4847 struct bpf_load_program_attr load_attr;
4848 char *cp, errmsg[STRERR_BUFSIZE];
4849 int log_buf_size = BPF_LOG_BUF_SIZE;
4853 if (!insns || !insns_cnt)
4856 memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
4857 load_attr.prog_type = prog->type;
4858 load_attr.expected_attach_type = prog->expected_attach_type;
4859 if (prog->caps->name)
4860 load_attr.name = prog->name;
4861 load_attr.insns = insns;
4862 load_attr.insns_cnt = insns_cnt;
4863 load_attr.license = license;
4864 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) {
4865 load_attr.attach_btf_id = prog->attach_btf_id;
4866 } else if (prog->type == BPF_PROG_TYPE_TRACING ||
4867 prog->type == BPF_PROG_TYPE_EXT) {
4868 load_attr.attach_prog_fd = prog->attach_prog_fd;
4869 load_attr.attach_btf_id = prog->attach_btf_id;
4871 load_attr.kern_version = kern_version;
4872 load_attr.prog_ifindex = prog->prog_ifindex;
4874 /* if .BTF.ext was loaded, kernel supports associated BTF for prog */
4875 if (prog->obj->btf_ext)
4876 btf_fd = bpf_object__btf_fd(prog->obj);
4879 load_attr.prog_btf_fd = btf_fd >= 0 ? btf_fd : 0;
4880 load_attr.func_info = prog->func_info;
4881 load_attr.func_info_rec_size = prog->func_info_rec_size;
4882 load_attr.func_info_cnt = prog->func_info_cnt;
4883 load_attr.line_info = prog->line_info;
4884 load_attr.line_info_rec_size = prog->line_info_rec_size;
4885 load_attr.line_info_cnt = prog->line_info_cnt;
4886 load_attr.log_level = prog->log_level;
4887 load_attr.prog_flags = prog->prog_flags;
4890 log_buf = malloc(log_buf_size);
4892 pr_warn("Alloc log buffer for bpf loader error, continue without log\n");
4894 ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
4897 if (load_attr.log_level)
4898 pr_debug("verifier log:\n%s", log_buf);
4904 if (errno == ENOSPC) {
4910 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
4911 pr_warn("load bpf program failed: %s\n", cp);
4914 if (log_buf && log_buf[0] != '\0') {
4915 ret = -LIBBPF_ERRNO__VERIFY;
4916 pr_warn("-- BEGIN DUMP LOG ---\n");
4917 pr_warn("\n%s\n", log_buf);
4918 pr_warn("-- END LOG --\n");
4919 } else if (load_attr.insns_cnt >= BPF_MAXINSNS) {
4920 pr_warn("Program too large (%zu insns), at most %d insns\n",
4921 load_attr.insns_cnt, BPF_MAXINSNS);
4922 ret = -LIBBPF_ERRNO__PROG2BIG;
4923 } else if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
4924 /* Wrong program type? */
4927 load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
4928 load_attr.expected_attach_type = 0;
4929 fd = bpf_load_program_xattr(&load_attr, NULL, 0);
4932 ret = -LIBBPF_ERRNO__PROGTYPE;
4942 static int libbpf_find_attach_btf_id(struct bpf_program *prog);
4944 int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
4946 int err = 0, fd, i, btf_id;
4948 if (prog->type == BPF_PROG_TYPE_TRACING ||
4949 prog->type == BPF_PROG_TYPE_EXT) {
4950 btf_id = libbpf_find_attach_btf_id(prog);
4953 prog->attach_btf_id = btf_id;
4956 if (prog->instances.nr < 0 || !prog->instances.fds) {
4957 if (prog->preprocessor) {
4958 pr_warn("Internal error: can't load program '%s'\n",
4959 prog->section_name);
4960 return -LIBBPF_ERRNO__INTERNAL;
4963 prog->instances.fds = malloc(sizeof(int));
4964 if (!prog->instances.fds) {
4965 pr_warn("Not enough memory for BPF fds\n");
4968 prog->instances.nr = 1;
4969 prog->instances.fds[0] = -1;
4972 if (!prog->preprocessor) {
4973 if (prog->instances.nr != 1) {
4974 pr_warn("Program '%s' is inconsistent: nr(%d) != 1\n",
4975 prog->section_name, prog->instances.nr);
4977 err = load_program(prog, prog->insns, prog->insns_cnt,
4978 license, kern_ver, &fd);
4980 prog->instances.fds[0] = fd;
4984 for (i = 0; i < prog->instances.nr; i++) {
4985 struct bpf_prog_prep_result result;
4986 bpf_program_prep_t preprocessor = prog->preprocessor;
4988 memset(&result, 0, sizeof(result));
4989 err = preprocessor(prog, i, prog->insns,
4990 prog->insns_cnt, &result);
4992 pr_warn("Preprocessing the %dth instance of program '%s' failed\n",
4993 i, prog->section_name);
4997 if (!result.new_insn_ptr || !result.new_insn_cnt) {
4998 pr_debug("Skip loading the %dth instance of program '%s'\n",
4999 i, prog->section_name);
5000 prog->instances.fds[i] = -1;
5006 err = load_program(prog, result.new_insn_ptr,
5007 result.new_insn_cnt, license, kern_ver, &fd);
5009 pr_warn("Loading the %dth instance of program '%s' failed\n",
5010 i, prog->section_name);
5016 prog->instances.fds[i] = fd;
5020 pr_warn("failed to load program '%s'\n", prog->section_name);
5021 zfree(&prog->insns);
5022 prog->insns_cnt = 0;
5026 static bool bpf_program__is_function_storage(const struct bpf_program *prog,
5027 const struct bpf_object *obj)
5029 return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls;
5033 bpf_object__load_progs(struct bpf_object *obj, int log_level)
5038 for (i = 0; i < obj->nr_programs; i++) {
5039 if (bpf_program__is_function_storage(&obj->programs[i], obj))
5041 obj->programs[i].log_level |= log_level;
5042 err = bpf_program__load(&obj->programs[i],
5051 static struct bpf_object *
5052 __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
5053 const struct bpf_object_open_opts *opts)
5055 const char *obj_name, *kconfig;
5056 struct bpf_program *prog;
5057 struct bpf_object *obj;
5061 if (elf_version(EV_CURRENT) == EV_NONE) {
5062 pr_warn("failed to init libelf for %s\n",
5063 path ? : "(mem buf)");
5064 return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
5067 if (!OPTS_VALID(opts, bpf_object_open_opts))
5068 return ERR_PTR(-EINVAL);
5070 obj_name = OPTS_GET(opts, object_name, NULL);
5073 snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
5074 (unsigned long)obj_buf,
5075 (unsigned long)obj_buf_sz);
5076 obj_name = tmp_name;
5079 pr_debug("loading object '%s' from buffer\n", obj_name);
5082 obj = bpf_object__new(path, obj_buf, obj_buf_sz, obj_name);
5086 kconfig = OPTS_GET(opts, kconfig, NULL);
5088 obj->kconfig = strdup(kconfig);
5090 return ERR_PTR(-ENOMEM);
5093 err = bpf_object__elf_init(obj);
5094 err = err ? : bpf_object__check_endianness(obj);
5095 err = err ? : bpf_object__elf_collect(obj);
5096 err = err ? : bpf_object__collect_externs(obj);
5097 err = err ? : bpf_object__finalize_btf(obj);
5098 err = err ? : bpf_object__init_maps(obj, opts);
5099 err = err ? : bpf_object__init_prog_names(obj);
5100 err = err ? : bpf_object__collect_reloc(obj);
5103 bpf_object__elf_finish(obj);
5105 bpf_object__for_each_program(prog, obj) {
5106 enum bpf_prog_type prog_type;
5107 enum bpf_attach_type attach_type;
5109 if (prog->type != BPF_PROG_TYPE_UNSPEC)
5112 err = libbpf_prog_type_by_name(prog->section_name, &prog_type,
5115 /* couldn't guess, but user might manually specify */
5120 bpf_program__set_type(prog, prog_type);
5121 bpf_program__set_expected_attach_type(prog, attach_type);
5122 if (prog_type == BPF_PROG_TYPE_TRACING ||
5123 prog_type == BPF_PROG_TYPE_EXT)
5124 prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
5129 bpf_object__close(obj);
5130 return ERR_PTR(err);
5133 static struct bpf_object *
5134 __bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags)
5136 DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
5137 .relaxed_maps = flags & MAPS_RELAX_COMPAT,
5140 /* param validation */
5144 pr_debug("loading %s\n", attr->file);
5145 return __bpf_object__open(attr->file, NULL, 0, &opts);
5148 struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
5150 return __bpf_object__open_xattr(attr, 0);
5153 struct bpf_object *bpf_object__open(const char *path)
5155 struct bpf_object_open_attr attr = {
5157 .prog_type = BPF_PROG_TYPE_UNSPEC,
5160 return bpf_object__open_xattr(&attr);
5164 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts)
5167 return ERR_PTR(-EINVAL);
5169 pr_debug("loading %s\n", path);
5171 return __bpf_object__open(path, NULL, 0, opts);
5175 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
5176 const struct bpf_object_open_opts *opts)
5178 if (!obj_buf || obj_buf_sz == 0)
5179 return ERR_PTR(-EINVAL);
5181 return __bpf_object__open(NULL, obj_buf, obj_buf_sz, opts);
5185 bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
5188 DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
5189 .object_name = name,
5190 /* wrong default, but backwards-compatible */
5191 .relaxed_maps = true,
5194 /* returning NULL is wrong, but backwards-compatible */
5195 if (!obj_buf || obj_buf_sz == 0)
5198 return bpf_object__open_mem(obj_buf, obj_buf_sz, &opts);
5201 int bpf_object__unload(struct bpf_object *obj)
5208 for (i = 0; i < obj->nr_maps; i++) {
5209 zclose(obj->maps[i].fd);
5210 if (obj->maps[i].st_ops)
5211 zfree(&obj->maps[i].st_ops->kern_vdata);
5214 for (i = 0; i < obj->nr_programs; i++)
5215 bpf_program__unload(&obj->programs[i]);
5220 static int bpf_object__sanitize_maps(struct bpf_object *obj)
5224 bpf_object__for_each_map(m, obj) {
5225 if (!bpf_map__is_internal(m))
5227 if (!obj->caps.global_data) {
5228 pr_warn("kernel doesn't support global data\n");
5231 if (!obj->caps.array_mmap)
5232 m->def.map_flags ^= BPF_F_MMAPABLE;
5238 static int bpf_object__resolve_externs(struct bpf_object *obj,
5239 const char *extra_kconfig)
5241 bool need_config = false;
5242 struct extern_desc *ext;
5246 if (obj->nr_extern == 0)
5249 data = obj->maps[obj->kconfig_map_idx].mmaped;
5251 for (i = 0; i < obj->nr_extern; i++) {
5252 ext = &obj->externs[i];
5254 if (strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) {
5255 void *ext_val = data + ext->data_off;
5256 __u32 kver = get_kernel_version();
5259 pr_warn("failed to get kernel version\n");
5262 err = set_ext_value_num(ext, ext_val, kver);
5265 pr_debug("extern %s=0x%x\n", ext->name, kver);
5266 } else if (strncmp(ext->name, "CONFIG_", 7) == 0) {
5269 pr_warn("unrecognized extern '%s'\n", ext->name);
5273 if (need_config && extra_kconfig) {
5274 err = bpf_object__read_kconfig_mem(obj, extra_kconfig, data);
5277 need_config = false;
5278 for (i = 0; i < obj->nr_extern; i++) {
5279 ext = &obj->externs[i];
5287 err = bpf_object__read_kconfig_file(obj, data);
5291 for (i = 0; i < obj->nr_extern; i++) {
5292 ext = &obj->externs[i];
5294 if (!ext->is_set && !ext->is_weak) {
5295 pr_warn("extern %s (strong) not resolved\n", ext->name);
5297 } else if (!ext->is_set) {
5298 pr_debug("extern %s (weak) not resolved, defaulting to zero\n",
5306 int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
5308 struct bpf_object *obj;
5318 pr_warn("object should not be loaded twice\n");
5324 err = bpf_object__probe_caps(obj);
5325 err = err ? : bpf_object__resolve_externs(obj, obj->kconfig);
5326 err = err ? : bpf_object__sanitize_and_load_btf(obj);
5327 err = err ? : bpf_object__sanitize_maps(obj);
5328 err = err ? : bpf_object__load_vmlinux_btf(obj);
5329 err = err ? : bpf_object__init_kern_struct_ops_maps(obj);
5330 err = err ? : bpf_object__create_maps(obj);
5331 err = err ? : bpf_object__relocate(obj, attr->target_btf_path);
5332 err = err ? : bpf_object__load_progs(obj, attr->log_level);
5334 btf__free(obj->btf_vmlinux);
5335 obj->btf_vmlinux = NULL;
5342 /* unpin any maps that were auto-pinned during load */
5343 for (i = 0; i < obj->nr_maps; i++)
5344 if (obj->maps[i].pinned && !obj->maps[i].reused)
5345 bpf_map__unpin(&obj->maps[i], NULL);
5347 bpf_object__unload(obj);
5348 pr_warn("failed to load object '%s'\n", obj->path);
5352 int bpf_object__load(struct bpf_object *obj)
5354 struct bpf_object_load_attr attr = {
5358 return bpf_object__load_xattr(&attr);
5361 static int make_parent_dir(const char *path)
5363 char *cp, errmsg[STRERR_BUFSIZE];
5367 dname = strdup(path);
5371 dir = dirname(dname);
5372 if (mkdir(dir, 0700) && errno != EEXIST)
5377 cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
5378 pr_warn("failed to mkdir %s: %s\n", path, cp);
5383 static int check_path(const char *path)
5385 char *cp, errmsg[STRERR_BUFSIZE];
5386 struct statfs st_fs;
5393 dname = strdup(path);
5397 dir = dirname(dname);
5398 if (statfs(dir, &st_fs)) {
5399 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
5400 pr_warn("failed to statfs %s: %s\n", dir, cp);
5405 if (!err && st_fs.f_type != BPF_FS_MAGIC) {
5406 pr_warn("specified path %s is not on BPF FS\n", path);
5413 int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
5416 char *cp, errmsg[STRERR_BUFSIZE];
5419 err = make_parent_dir(path);
5423 err = check_path(path);
5428 pr_warn("invalid program pointer\n");
5432 if (instance < 0 || instance >= prog->instances.nr) {
5433 pr_warn("invalid prog instance %d of prog %s (max %d)\n",
5434 instance, prog->section_name, prog->instances.nr);
5438 if (bpf_obj_pin(prog->instances.fds[instance], path)) {
5439 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
5440 pr_warn("failed to pin program: %s\n", cp);
5443 pr_debug("pinned program '%s'\n", path);
5448 int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
5453 err = check_path(path);
5458 pr_warn("invalid program pointer\n");
5462 if (instance < 0 || instance >= prog->instances.nr) {
5463 pr_warn("invalid prog instance %d of prog %s (max %d)\n",
5464 instance, prog->section_name, prog->instances.nr);
5471 pr_debug("unpinned program '%s'\n", path);
5476 int bpf_program__pin(struct bpf_program *prog, const char *path)
5480 err = make_parent_dir(path);
5484 err = check_path(path);
5489 pr_warn("invalid program pointer\n");
5493 if (prog->instances.nr <= 0) {
5494 pr_warn("no instances of prog %s to pin\n",
5495 prog->section_name);
5499 if (prog->instances.nr == 1) {
5500 /* don't create subdirs when pinning single instance */
5501 return bpf_program__pin_instance(prog, path, 0);
5504 for (i = 0; i < prog->instances.nr; i++) {
5508 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
5512 } else if (len >= PATH_MAX) {
5513 err = -ENAMETOOLONG;
5517 err = bpf_program__pin_instance(prog, buf, i);
5525 for (i = i - 1; i >= 0; i--) {
5529 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
5532 else if (len >= PATH_MAX)
5535 bpf_program__unpin_instance(prog, buf, i);
5543 int bpf_program__unpin(struct bpf_program *prog, const char *path)
5547 err = check_path(path);
5552 pr_warn("invalid program pointer\n");
5556 if (prog->instances.nr <= 0) {
5557 pr_warn("no instances of prog %s to pin\n",
5558 prog->section_name);
5562 if (prog->instances.nr == 1) {
5563 /* don't create subdirs when pinning single instance */
5564 return bpf_program__unpin_instance(prog, path, 0);
5567 for (i = 0; i < prog->instances.nr; i++) {
5571 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
5574 else if (len >= PATH_MAX)
5575 return -ENAMETOOLONG;
5577 err = bpf_program__unpin_instance(prog, buf, i);
5589 int bpf_map__pin(struct bpf_map *map, const char *path)
5591 char *cp, errmsg[STRERR_BUFSIZE];
5595 pr_warn("invalid map pointer\n");
5599 if (map->pin_path) {
5600 if (path && strcmp(path, map->pin_path)) {
5601 pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
5602 bpf_map__name(map), map->pin_path, path);
5604 } else if (map->pinned) {
5605 pr_debug("map '%s' already pinned at '%s'; not re-pinning\n",
5606 bpf_map__name(map), map->pin_path);
5611 pr_warn("missing a path to pin map '%s' at\n",
5612 bpf_map__name(map));
5614 } else if (map->pinned) {
5615 pr_warn("map '%s' already pinned\n", bpf_map__name(map));
5619 map->pin_path = strdup(path);
5620 if (!map->pin_path) {
5626 err = make_parent_dir(map->pin_path);
5630 err = check_path(map->pin_path);
5634 if (bpf_obj_pin(map->fd, map->pin_path)) {
5640 pr_debug("pinned map '%s'\n", map->pin_path);
5645 cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
5646 pr_warn("failed to pin map: %s\n", cp);
5650 int bpf_map__unpin(struct bpf_map *map, const char *path)
5655 pr_warn("invalid map pointer\n");
5659 if (map->pin_path) {
5660 if (path && strcmp(path, map->pin_path)) {
5661 pr_warn("map '%s' already has pin path '%s' different from '%s'\n",
5662 bpf_map__name(map), map->pin_path, path);
5665 path = map->pin_path;
5667 pr_warn("no path to unpin map '%s' from\n",
5668 bpf_map__name(map));
5672 err = check_path(path);
5680 map->pinned = false;
5681 pr_debug("unpinned map '%s' from '%s'\n", bpf_map__name(map), path);
5686 int bpf_map__set_pin_path(struct bpf_map *map, const char *path)
5696 free(map->pin_path);
5697 map->pin_path = new;
5701 const char *bpf_map__get_pin_path(const struct bpf_map *map)
5703 return map->pin_path;
5706 bool bpf_map__is_pinned(const struct bpf_map *map)
5711 int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
5713 struct bpf_map *map;
5720 pr_warn("object not yet loaded; load it first\n");
5724 bpf_object__for_each_map(map, obj) {
5725 char *pin_path = NULL;
5731 len = snprintf(buf, PATH_MAX, "%s/%s", path,
5732 bpf_map__name(map));
5735 goto err_unpin_maps;
5736 } else if (len >= PATH_MAX) {
5737 err = -ENAMETOOLONG;
5738 goto err_unpin_maps;
5741 } else if (!map->pin_path) {
5745 err = bpf_map__pin(map, pin_path);
5747 goto err_unpin_maps;
5753 while ((map = bpf_map__prev(map, obj))) {
5757 bpf_map__unpin(map, NULL);
5763 int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
5765 struct bpf_map *map;
5771 bpf_object__for_each_map(map, obj) {
5772 char *pin_path = NULL;
5778 len = snprintf(buf, PATH_MAX, "%s/%s", path,
5779 bpf_map__name(map));
5782 else if (len >= PATH_MAX)
5783 return -ENAMETOOLONG;
5785 } else if (!map->pin_path) {
5789 err = bpf_map__unpin(map, pin_path);
5797 int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
5799 struct bpf_program *prog;
5806 pr_warn("object not yet loaded; load it first\n");
5810 bpf_object__for_each_program(prog, obj) {
5814 len = snprintf(buf, PATH_MAX, "%s/%s", path,
5818 goto err_unpin_programs;
5819 } else if (len >= PATH_MAX) {
5820 err = -ENAMETOOLONG;
5821 goto err_unpin_programs;
5824 err = bpf_program__pin(prog, buf);
5826 goto err_unpin_programs;
5832 while ((prog = bpf_program__prev(prog, obj))) {
5836 len = snprintf(buf, PATH_MAX, "%s/%s", path,
5840 else if (len >= PATH_MAX)
5843 bpf_program__unpin(prog, buf);
5849 int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
5851 struct bpf_program *prog;
5857 bpf_object__for_each_program(prog, obj) {
5861 len = snprintf(buf, PATH_MAX, "%s/%s", path,
5865 else if (len >= PATH_MAX)
5866 return -ENAMETOOLONG;
5868 err = bpf_program__unpin(prog, buf);
5876 int bpf_object__pin(struct bpf_object *obj, const char *path)
5880 err = bpf_object__pin_maps(obj, path);
5884 err = bpf_object__pin_programs(obj, path);
5886 bpf_object__unpin_maps(obj, path);
5893 void bpf_object__close(struct bpf_object *obj)
5900 if (obj->clear_priv)
5901 obj->clear_priv(obj, obj->priv);
5903 bpf_object__elf_finish(obj);
5904 bpf_object__unload(obj);
5905 btf__free(obj->btf);
5906 btf_ext__free(obj->btf_ext);
5908 for (i = 0; i < obj->nr_maps; i++) {
5909 struct bpf_map *map = &obj->maps[i];
5911 if (map->clear_priv)
5912 map->clear_priv(map, map->priv);
5914 map->clear_priv = NULL;
5917 munmap(map->mmaped, bpf_map_mmap_sz(map));
5922 zfree(&map->st_ops->data);
5923 zfree(&map->st_ops->progs);
5924 zfree(&map->st_ops->kern_func_off);
5925 zfree(&map->st_ops);
5929 zfree(&map->pin_path);
5932 zfree(&obj->kconfig);
5933 zfree(&obj->externs);
5939 if (obj->programs && obj->nr_programs) {
5940 for (i = 0; i < obj->nr_programs; i++)
5941 bpf_program__exit(&obj->programs[i]);
5943 zfree(&obj->programs);
5945 list_del(&obj->list);
5950 bpf_object__next(struct bpf_object *prev)
5952 struct bpf_object *next;
5955 next = list_first_entry(&bpf_objects_list,
5959 next = list_next_entry(prev, list);
5961 /* Empty list is noticed here so don't need checking on entry. */
5962 if (&next->list == &bpf_objects_list)
5968 const char *bpf_object__name(const struct bpf_object *obj)
5970 return obj ? obj->name : ERR_PTR(-EINVAL);
5973 unsigned int bpf_object__kversion(const struct bpf_object *obj)
5975 return obj ? obj->kern_version : 0;
5978 struct btf *bpf_object__btf(const struct bpf_object *obj)
5980 return obj ? obj->btf : NULL;
5983 int bpf_object__btf_fd(const struct bpf_object *obj)
5985 return obj->btf ? btf__fd(obj->btf) : -1;
5988 int bpf_object__set_priv(struct bpf_object *obj, void *priv,
5989 bpf_object_clear_priv_t clear_priv)
5991 if (obj->priv && obj->clear_priv)
5992 obj->clear_priv(obj, obj->priv);
5995 obj->clear_priv = clear_priv;
5999 void *bpf_object__priv(const struct bpf_object *obj)
6001 return obj ? obj->priv : ERR_PTR(-EINVAL);
6004 static struct bpf_program *
6005 __bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj,
6008 size_t nr_programs = obj->nr_programs;
6015 /* Iter from the beginning */
6016 return forward ? &obj->programs[0] :
6017 &obj->programs[nr_programs - 1];
6019 if (p->obj != obj) {
6020 pr_warn("error: program handler doesn't match object\n");
6024 idx = (p - obj->programs) + (forward ? 1 : -1);
6025 if (idx >= obj->nr_programs || idx < 0)
6027 return &obj->programs[idx];
6030 struct bpf_program *
6031 bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj)
6033 struct bpf_program *prog = prev;
6036 prog = __bpf_program__iter(prog, obj, true);
6037 } while (prog && bpf_program__is_function_storage(prog, obj));
6042 struct bpf_program *
6043 bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj)
6045 struct bpf_program *prog = next;
6048 prog = __bpf_program__iter(prog, obj, false);
6049 } while (prog && bpf_program__is_function_storage(prog, obj));
6054 int bpf_program__set_priv(struct bpf_program *prog, void *priv,
6055 bpf_program_clear_priv_t clear_priv)
6057 if (prog->priv && prog->clear_priv)
6058 prog->clear_priv(prog, prog->priv);
6061 prog->clear_priv = clear_priv;
6065 void *bpf_program__priv(const struct bpf_program *prog)
6067 return prog ? prog->priv : ERR_PTR(-EINVAL);
6070 void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex)
6072 prog->prog_ifindex = ifindex;
6075 const char *bpf_program__name(const struct bpf_program *prog)
6080 const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy)
6084 title = prog->section_name;
6086 title = strdup(title);
6088 pr_warn("failed to strdup program title\n");
6089 return ERR_PTR(-ENOMEM);
6096 int bpf_program__fd(const struct bpf_program *prog)
6098 return bpf_program__nth_fd(prog, 0);
6101 size_t bpf_program__size(const struct bpf_program *prog)
6103 return prog->insns_cnt * sizeof(struct bpf_insn);
6106 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
6107 bpf_program_prep_t prep)
6111 if (nr_instances <= 0 || !prep)
6114 if (prog->instances.nr > 0 || prog->instances.fds) {
6115 pr_warn("Can't set pre-processor after loading\n");
6119 instances_fds = malloc(sizeof(int) * nr_instances);
6120 if (!instances_fds) {
6121 pr_warn("alloc memory failed for fds\n");
6125 /* fill all fd with -1 */
6126 memset(instances_fds, -1, sizeof(int) * nr_instances);
6128 prog->instances.nr = nr_instances;
6129 prog->instances.fds = instances_fds;
6130 prog->preprocessor = prep;
6134 int bpf_program__nth_fd(const struct bpf_program *prog, int n)
6141 if (n >= prog->instances.nr || n < 0) {
6142 pr_warn("Can't get the %dth fd from program %s: only %d instances\n",
6143 n, prog->section_name, prog->instances.nr);
6147 fd = prog->instances.fds[n];
6149 pr_warn("%dth instance of program '%s' is invalid\n",
6150 n, prog->section_name);
6157 enum bpf_prog_type bpf_program__get_type(struct bpf_program *prog)
6162 void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
6167 static bool bpf_program__is_type(const struct bpf_program *prog,
6168 enum bpf_prog_type type)
6170 return prog ? (prog->type == type) : false;
6173 #define BPF_PROG_TYPE_FNS(NAME, TYPE) \
6174 int bpf_program__set_##NAME(struct bpf_program *prog) \
6178 bpf_program__set_type(prog, TYPE); \
6182 bool bpf_program__is_##NAME(const struct bpf_program *prog) \
6184 return bpf_program__is_type(prog, TYPE); \
6187 BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER);
6188 BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE);
6189 BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS);
6190 BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT);
6191 BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT);
6192 BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT);
6193 BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP);
6194 BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT);
6195 BPF_PROG_TYPE_FNS(tracing, BPF_PROG_TYPE_TRACING);
6196 BPF_PROG_TYPE_FNS(struct_ops, BPF_PROG_TYPE_STRUCT_OPS);
6197 BPF_PROG_TYPE_FNS(extension, BPF_PROG_TYPE_EXT);
6199 enum bpf_attach_type
6200 bpf_program__get_expected_attach_type(struct bpf_program *prog)
6202 return prog->expected_attach_type;
6205 void bpf_program__set_expected_attach_type(struct bpf_program *prog,
6206 enum bpf_attach_type type)
6208 prog->expected_attach_type = type;
6211 #define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, btf, atype) \
6212 { string, sizeof(string) - 1, ptype, eatype, is_attachable, btf, atype }
6214 /* Programs that can NOT be attached. */
6215 #define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0, 0)
6217 /* Programs that can be attached. */
6218 #define BPF_APROG_SEC(string, ptype, atype) \
6219 BPF_PROG_SEC_IMPL(string, ptype, 0, 1, 0, atype)
6221 /* Programs that must specify expected attach type at load time. */
6222 #define BPF_EAPROG_SEC(string, ptype, eatype) \
6223 BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, 0, eatype)
6225 /* Programs that use BTF to identify attach point */
6226 #define BPF_PROG_BTF(string, ptype, eatype) \
6227 BPF_PROG_SEC_IMPL(string, ptype, eatype, 0, 1, 0)
6229 /* Programs that can be attached but attach type can't be identified by section
6230 * name. Kept for backward compatibility.
6232 #define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
6234 #define SEC_DEF(sec_pfx, ptype, ...) { \
6236 .len = sizeof(sec_pfx) - 1, \
6237 .prog_type = BPF_PROG_TYPE_##ptype, \
6243 typedef struct bpf_link *(*attach_fn_t)(const struct bpf_sec_def *sec,
6244 struct bpf_program *prog);
6246 static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
6247 struct bpf_program *prog);
6248 static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
6249 struct bpf_program *prog);
6250 static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
6251 struct bpf_program *prog);
6252 static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
6253 struct bpf_program *prog);
6255 struct bpf_sec_def {
6258 enum bpf_prog_type prog_type;
6259 enum bpf_attach_type expected_attach_type;
6262 enum bpf_attach_type attach_type;
6263 attach_fn_t attach_fn;
6266 static const struct bpf_sec_def section_defs[] = {
6267 BPF_PROG_SEC("socket", BPF_PROG_TYPE_SOCKET_FILTER),
6268 BPF_PROG_SEC("sk_reuseport", BPF_PROG_TYPE_SK_REUSEPORT),
6269 SEC_DEF("kprobe/", KPROBE,
6270 .attach_fn = attach_kprobe),
6271 BPF_PROG_SEC("uprobe/", BPF_PROG_TYPE_KPROBE),
6272 SEC_DEF("kretprobe/", KPROBE,
6273 .attach_fn = attach_kprobe),
6274 BPF_PROG_SEC("uretprobe/", BPF_PROG_TYPE_KPROBE),
6275 BPF_PROG_SEC("classifier", BPF_PROG_TYPE_SCHED_CLS),
6276 BPF_PROG_SEC("action", BPF_PROG_TYPE_SCHED_ACT),
6277 SEC_DEF("tracepoint/", TRACEPOINT,
6278 .attach_fn = attach_tp),
6279 SEC_DEF("tp/", TRACEPOINT,
6280 .attach_fn = attach_tp),
6281 SEC_DEF("raw_tracepoint/", RAW_TRACEPOINT,
6282 .attach_fn = attach_raw_tp),
6283 SEC_DEF("raw_tp/", RAW_TRACEPOINT,
6284 .attach_fn = attach_raw_tp),
6285 SEC_DEF("tp_btf/", TRACING,
6286 .expected_attach_type = BPF_TRACE_RAW_TP,
6287 .is_attach_btf = true,
6288 .attach_fn = attach_trace),
6289 SEC_DEF("fentry/", TRACING,
6290 .expected_attach_type = BPF_TRACE_FENTRY,
6291 .is_attach_btf = true,
6292 .attach_fn = attach_trace),
6293 SEC_DEF("fexit/", TRACING,
6294 .expected_attach_type = BPF_TRACE_FEXIT,
6295 .is_attach_btf = true,
6296 .attach_fn = attach_trace),
6297 SEC_DEF("freplace/", EXT,
6298 .is_attach_btf = true,
6299 .attach_fn = attach_trace),
6300 BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP),
6301 BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT),
6302 BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN),
6303 BPF_PROG_SEC("lwt_out", BPF_PROG_TYPE_LWT_OUT),
6304 BPF_PROG_SEC("lwt_xmit", BPF_PROG_TYPE_LWT_XMIT),
6305 BPF_PROG_SEC("lwt_seg6local", BPF_PROG_TYPE_LWT_SEG6LOCAL),
6306 BPF_APROG_SEC("cgroup_skb/ingress", BPF_PROG_TYPE_CGROUP_SKB,
6307 BPF_CGROUP_INET_INGRESS),
6308 BPF_APROG_SEC("cgroup_skb/egress", BPF_PROG_TYPE_CGROUP_SKB,
6309 BPF_CGROUP_INET_EGRESS),
6310 BPF_APROG_COMPAT("cgroup/skb", BPF_PROG_TYPE_CGROUP_SKB),
6311 BPF_APROG_SEC("cgroup/sock", BPF_PROG_TYPE_CGROUP_SOCK,
6312 BPF_CGROUP_INET_SOCK_CREATE),
6313 BPF_EAPROG_SEC("cgroup/post_bind4", BPF_PROG_TYPE_CGROUP_SOCK,
6314 BPF_CGROUP_INET4_POST_BIND),
6315 BPF_EAPROG_SEC("cgroup/post_bind6", BPF_PROG_TYPE_CGROUP_SOCK,
6316 BPF_CGROUP_INET6_POST_BIND),
6317 BPF_APROG_SEC("cgroup/dev", BPF_PROG_TYPE_CGROUP_DEVICE,
6319 BPF_APROG_SEC("sockops", BPF_PROG_TYPE_SOCK_OPS,
6320 BPF_CGROUP_SOCK_OPS),
6321 BPF_APROG_SEC("sk_skb/stream_parser", BPF_PROG_TYPE_SK_SKB,
6322 BPF_SK_SKB_STREAM_PARSER),
6323 BPF_APROG_SEC("sk_skb/stream_verdict", BPF_PROG_TYPE_SK_SKB,
6324 BPF_SK_SKB_STREAM_VERDICT),
6325 BPF_APROG_COMPAT("sk_skb", BPF_PROG_TYPE_SK_SKB),
6326 BPF_APROG_SEC("sk_msg", BPF_PROG_TYPE_SK_MSG,
6327 BPF_SK_MSG_VERDICT),
6328 BPF_APROG_SEC("lirc_mode2", BPF_PROG_TYPE_LIRC_MODE2,
6330 BPF_APROG_SEC("flow_dissector", BPF_PROG_TYPE_FLOW_DISSECTOR,
6331 BPF_FLOW_DISSECTOR),
6332 BPF_EAPROG_SEC("cgroup/bind4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6333 BPF_CGROUP_INET4_BIND),
6334 BPF_EAPROG_SEC("cgroup/bind6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6335 BPF_CGROUP_INET6_BIND),
6336 BPF_EAPROG_SEC("cgroup/connect4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6337 BPF_CGROUP_INET4_CONNECT),
6338 BPF_EAPROG_SEC("cgroup/connect6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6339 BPF_CGROUP_INET6_CONNECT),
6340 BPF_EAPROG_SEC("cgroup/sendmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6341 BPF_CGROUP_UDP4_SENDMSG),
6342 BPF_EAPROG_SEC("cgroup/sendmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6343 BPF_CGROUP_UDP6_SENDMSG),
6344 BPF_EAPROG_SEC("cgroup/recvmsg4", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6345 BPF_CGROUP_UDP4_RECVMSG),
6346 BPF_EAPROG_SEC("cgroup/recvmsg6", BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
6347 BPF_CGROUP_UDP6_RECVMSG),
6348 BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL,
6350 BPF_EAPROG_SEC("cgroup/getsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
6351 BPF_CGROUP_GETSOCKOPT),
6352 BPF_EAPROG_SEC("cgroup/setsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
6353 BPF_CGROUP_SETSOCKOPT),
6354 BPF_PROG_SEC("struct_ops", BPF_PROG_TYPE_STRUCT_OPS),
6357 #undef BPF_PROG_SEC_IMPL
6359 #undef BPF_APROG_SEC
6360 #undef BPF_EAPROG_SEC
6361 #undef BPF_APROG_COMPAT
6364 #define MAX_TYPE_NAME_SIZE 32
6366 static const struct bpf_sec_def *find_sec_def(const char *sec_name)
6368 int i, n = ARRAY_SIZE(section_defs);
6370 for (i = 0; i < n; i++) {
6371 if (strncmp(sec_name,
6372 section_defs[i].sec, section_defs[i].len))
6374 return §ion_defs[i];
6379 static char *libbpf_get_type_names(bool attach_type)
6381 int i, len = ARRAY_SIZE(section_defs) * MAX_TYPE_NAME_SIZE;
6389 /* Forge string buf with all available names */
6390 for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
6391 if (attach_type && !section_defs[i].is_attachable)
6394 if (strlen(buf) + strlen(section_defs[i].sec) + 2 > len) {
6399 strcat(buf, section_defs[i].sec);
6405 int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
6406 enum bpf_attach_type *expected_attach_type)
6408 const struct bpf_sec_def *sec_def;
6414 sec_def = find_sec_def(name);
6416 *prog_type = sec_def->prog_type;
6417 *expected_attach_type = sec_def->expected_attach_type;
6421 pr_debug("failed to guess program type from ELF section '%s'\n", name);
6422 type_names = libbpf_get_type_names(false);
6423 if (type_names != NULL) {
6424 pr_debug("supported section(type) names are:%s\n", type_names);
6431 static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj,
6434 struct bpf_map *map;
6437 for (i = 0; i < obj->nr_maps; i++) {
6438 map = &obj->maps[i];
6439 if (!bpf_map__is_struct_ops(map))
6441 if (map->sec_offset <= offset &&
6442 offset - map->sec_offset < map->def.value_size)
6449 /* Collect the reloc from ELF and populate the st_ops->progs[] */
6450 static int bpf_object__collect_struct_ops_map_reloc(struct bpf_object *obj,
6454 const struct btf_member *member;
6455 struct bpf_struct_ops *st_ops;
6456 struct bpf_program *prog;
6457 unsigned int shdr_idx;
6458 const struct btf *btf;
6459 struct bpf_map *map;
6468 symbols = obj->efile.symbols;
6470 nrels = shdr->sh_size / shdr->sh_entsize;
6471 for (i = 0; i < nrels; i++) {
6472 if (!gelf_getrel(data, i, &rel)) {
6473 pr_warn("struct_ops reloc: failed to get %d reloc\n", i);
6474 return -LIBBPF_ERRNO__FORMAT;
6477 if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
6478 pr_warn("struct_ops reloc: symbol %zx not found\n",
6479 (size_t)GELF_R_SYM(rel.r_info));
6480 return -LIBBPF_ERRNO__FORMAT;
6483 name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
6484 sym.st_name) ? : "<?>";
6485 map = find_struct_ops_map_by_offset(obj, rel.r_offset);
6487 pr_warn("struct_ops reloc: cannot find map at rel.r_offset %zu\n",
6488 (size_t)rel.r_offset);
6492 moff = rel.r_offset - map->sec_offset;
6493 shdr_idx = sym.st_shndx;
6494 st_ops = map->st_ops;
6495 pr_debug("struct_ops reloc %s: for %lld value %lld shdr_idx %u rel.r_offset %zu map->sec_offset %zu name %d (\'%s\')\n",
6497 (long long)(rel.r_info >> 32),
6498 (long long)sym.st_value,
6499 shdr_idx, (size_t)rel.r_offset,
6500 map->sec_offset, sym.st_name, name);
6502 if (shdr_idx >= SHN_LORESERVE) {
6503 pr_warn("struct_ops reloc %s: rel.r_offset %zu shdr_idx %u unsupported non-static function\n",
6504 map->name, (size_t)rel.r_offset, shdr_idx);
6505 return -LIBBPF_ERRNO__RELOC;
6508 member = find_member_by_offset(st_ops->type, moff * 8);
6510 pr_warn("struct_ops reloc %s: cannot find member at moff %u\n",
6514 member_idx = member - btf_members(st_ops->type);
6515 name = btf__name_by_offset(btf, member->name_off);
6517 if (!resolve_func_ptr(btf, member->type, NULL)) {
6518 pr_warn("struct_ops reloc %s: cannot relocate non func ptr %s\n",
6523 prog = bpf_object__find_prog_by_idx(obj, shdr_idx);
6525 pr_warn("struct_ops reloc %s: cannot find prog at shdr_idx %u to relocate func ptr %s\n",
6526 map->name, shdr_idx, name);
6530 if (prog->type == BPF_PROG_TYPE_UNSPEC) {
6531 const struct bpf_sec_def *sec_def;
6533 sec_def = find_sec_def(prog->section_name);
6535 sec_def->prog_type != BPF_PROG_TYPE_STRUCT_OPS) {
6537 prog->type = sec_def->prog_type;
6541 prog->type = BPF_PROG_TYPE_STRUCT_OPS;
6542 prog->attach_btf_id = st_ops->type_id;
6543 prog->expected_attach_type = member_idx;
6544 } else if (prog->type != BPF_PROG_TYPE_STRUCT_OPS ||
6545 prog->attach_btf_id != st_ops->type_id ||
6546 prog->expected_attach_type != member_idx) {
6549 st_ops->progs[member_idx] = prog;
6555 pr_warn("struct_ops reloc %s: cannot use prog %s in sec %s with type %u attach_btf_id %u expected_attach_type %u for func ptr %s\n",
6556 map->name, prog->name, prog->section_name, prog->type,
6557 prog->attach_btf_id, prog->expected_attach_type, name);
6561 #define BTF_TRACE_PREFIX "btf_trace_"
6562 #define BTF_MAX_NAME_SIZE 128
6564 static int find_btf_by_prefix_kind(const struct btf *btf, const char *prefix,
6565 const char *name, __u32 kind)
6567 char btf_type_name[BTF_MAX_NAME_SIZE];
6570 ret = snprintf(btf_type_name, sizeof(btf_type_name),
6571 "%s%s", prefix, name);
6572 /* snprintf returns the number of characters written excluding the
6573 * the terminating null. So, if >= BTF_MAX_NAME_SIZE are written, it
6574 * indicates truncation.
6576 if (ret < 0 || ret >= sizeof(btf_type_name))
6577 return -ENAMETOOLONG;
6578 return btf__find_by_name_kind(btf, btf_type_name, kind);
6581 static inline int __find_vmlinux_btf_id(struct btf *btf, const char *name,
6582 enum bpf_attach_type attach_type)
6586 if (attach_type == BPF_TRACE_RAW_TP)
6587 err = find_btf_by_prefix_kind(btf, BTF_TRACE_PREFIX, name,
6590 err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
6595 int libbpf_find_vmlinux_btf_id(const char *name,
6596 enum bpf_attach_type attach_type)
6600 btf = libbpf_find_kernel_btf();
6602 pr_warn("vmlinux BTF is not found\n");
6606 return __find_vmlinux_btf_id(btf, name, attach_type);
6609 static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
6611 struct bpf_prog_info_linear *info_linear;
6612 struct bpf_prog_info *info;
6613 struct btf *btf = NULL;
6616 info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);
6617 if (IS_ERR_OR_NULL(info_linear)) {
6618 pr_warn("failed get_prog_info_linear for FD %d\n",
6622 info = &info_linear->info;
6623 if (!info->btf_id) {
6624 pr_warn("The target program doesn't have BTF\n");
6627 if (btf__get_from_id(info->btf_id, &btf)) {
6628 pr_warn("Failed to get BTF of the program\n");
6631 err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
6634 pr_warn("%s is not found in prog's BTF\n", name);
6642 static int libbpf_find_attach_btf_id(struct bpf_program *prog)
6644 enum bpf_attach_type attach_type = prog->expected_attach_type;
6645 __u32 attach_prog_fd = prog->attach_prog_fd;
6646 const char *name = prog->section_name;
6652 for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
6653 if (!section_defs[i].is_attach_btf)
6655 if (strncmp(name, section_defs[i].sec, section_defs[i].len))
6658 err = libbpf_find_prog_btf_id(name + section_defs[i].len,
6661 err = __find_vmlinux_btf_id(prog->obj->btf_vmlinux,
6662 name + section_defs[i].len,
6665 pr_warn("%s is not found in vmlinux BTF\n", name);
6668 pr_warn("failed to identify btf_id based on ELF section name '%s'\n", name);
6672 int libbpf_attach_type_by_name(const char *name,
6673 enum bpf_attach_type *attach_type)
6681 for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
6682 if (strncmp(name, section_defs[i].sec, section_defs[i].len))
6684 if (!section_defs[i].is_attachable)
6686 *attach_type = section_defs[i].attach_type;
6689 pr_debug("failed to guess attach type based on ELF section name '%s'\n", name);
6690 type_names = libbpf_get_type_names(true);
6691 if (type_names != NULL) {
6692 pr_debug("attachable section(type) names are:%s\n", type_names);
6699 int bpf_map__fd(const struct bpf_map *map)
6701 return map ? map->fd : -EINVAL;
6704 const struct bpf_map_def *bpf_map__def(const struct bpf_map *map)
6706 return map ? &map->def : ERR_PTR(-EINVAL);
6709 const char *bpf_map__name(const struct bpf_map *map)
6711 return map ? map->name : NULL;
6714 __u32 bpf_map__btf_key_type_id(const struct bpf_map *map)
6716 return map ? map->btf_key_type_id : 0;
6719 __u32 bpf_map__btf_value_type_id(const struct bpf_map *map)
6721 return map ? map->btf_value_type_id : 0;
6724 int bpf_map__set_priv(struct bpf_map *map, void *priv,
6725 bpf_map_clear_priv_t clear_priv)
6731 if (map->clear_priv)
6732 map->clear_priv(map, map->priv);
6736 map->clear_priv = clear_priv;
6740 void *bpf_map__priv(const struct bpf_map *map)
6742 return map ? map->priv : ERR_PTR(-EINVAL);
6745 bool bpf_map__is_offload_neutral(const struct bpf_map *map)
6747 return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
6750 bool bpf_map__is_internal(const struct bpf_map *map)
6752 return map->libbpf_type != LIBBPF_MAP_UNSPEC;
6755 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
6757 map->map_ifindex = ifindex;
6760 int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
6762 if (!bpf_map_type__is_map_in_map(map->def.type)) {
6763 pr_warn("error: unsupported map type\n");
6766 if (map->inner_map_fd != -1) {
6767 pr_warn("error: inner_map_fd already specified\n");
6770 map->inner_map_fd = fd;
6774 static struct bpf_map *
6775 __bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i)
6778 struct bpf_map *s, *e;
6780 if (!obj || !obj->maps)
6784 e = obj->maps + obj->nr_maps;
6786 if ((m < s) || (m >= e)) {
6787 pr_warn("error in %s: map handler doesn't belong to object\n",
6792 idx = (m - obj->maps) + i;
6793 if (idx >= obj->nr_maps || idx < 0)
6795 return &obj->maps[idx];
6799 bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj)
6804 return __bpf_map__iter(prev, obj, 1);
6808 bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj)
6813 return obj->maps + obj->nr_maps - 1;
6816 return __bpf_map__iter(next, obj, -1);
6820 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name)
6822 struct bpf_map *pos;
6824 bpf_object__for_each_map(pos, obj) {
6825 if (pos->name && !strcmp(pos->name, name))
6832 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name)
6834 return bpf_map__fd(bpf_object__find_map_by_name(obj, name));
6838 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset)
6840 return ERR_PTR(-ENOTSUP);
6843 long libbpf_get_error(const void *ptr)
6845 return PTR_ERR_OR_ZERO(ptr);
6848 int bpf_prog_load(const char *file, enum bpf_prog_type type,
6849 struct bpf_object **pobj, int *prog_fd)
6851 struct bpf_prog_load_attr attr;
6853 memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
6855 attr.prog_type = type;
6856 attr.expected_attach_type = 0;
6858 return bpf_prog_load_xattr(&attr, pobj, prog_fd);
6861 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
6862 struct bpf_object **pobj, int *prog_fd)
6864 struct bpf_object_open_attr open_attr = {};
6865 struct bpf_program *prog, *first_prog = NULL;
6866 struct bpf_object *obj;
6867 struct bpf_map *map;
6875 open_attr.file = attr->file;
6876 open_attr.prog_type = attr->prog_type;
6878 obj = bpf_object__open_xattr(&open_attr);
6879 if (IS_ERR_OR_NULL(obj))
6882 bpf_object__for_each_program(prog, obj) {
6883 enum bpf_attach_type attach_type = attr->expected_attach_type;
6885 * to preserve backwards compatibility, bpf_prog_load treats
6886 * attr->prog_type, if specified, as an override to whatever
6887 * bpf_object__open guessed
6889 if (attr->prog_type != BPF_PROG_TYPE_UNSPEC) {
6890 bpf_program__set_type(prog, attr->prog_type);
6891 bpf_program__set_expected_attach_type(prog,
6894 if (bpf_program__get_type(prog) == BPF_PROG_TYPE_UNSPEC) {
6896 * we haven't guessed from section name and user
6897 * didn't provide a fallback type, too bad...
6899 bpf_object__close(obj);
6903 prog->prog_ifindex = attr->ifindex;
6904 prog->log_level = attr->log_level;
6905 prog->prog_flags = attr->prog_flags;
6910 bpf_object__for_each_map(map, obj) {
6911 if (!bpf_map__is_offload_neutral(map))
6912 map->map_ifindex = attr->ifindex;
6916 pr_warn("object file doesn't contain bpf program\n");
6917 bpf_object__close(obj);
6921 err = bpf_object__load(obj);
6923 bpf_object__close(obj);
6928 *prog_fd = bpf_program__fd(first_prog);
6933 int (*detach)(struct bpf_link *link);
6934 int (*destroy)(struct bpf_link *link);
6938 /* Release "ownership" of underlying BPF resource (typically, BPF program
6939 * attached to some BPF hook, e.g., tracepoint, kprobe, etc). Disconnected
6940 * link, when destructed through bpf_link__destroy() call won't attempt to
6941 * detach/unregisted that BPF resource. This is useful in situations where,
6942 * say, attached BPF program has to outlive userspace program that attached it
6943 * in the system. Depending on type of BPF program, though, there might be
6944 * additional steps (like pinning BPF program in BPF FS) necessary to ensure
6945 * exit of userspace program doesn't trigger automatic detachment and clean up
6946 * inside the kernel.
6948 void bpf_link__disconnect(struct bpf_link *link)
6950 link->disconnected = true;
6953 int bpf_link__destroy(struct bpf_link *link)
6960 if (!link->disconnected && link->detach)
6961 err = link->detach(link);
6963 link->destroy(link);
6969 struct bpf_link_fd {
6970 struct bpf_link link; /* has to be at the top of struct */
6971 int fd; /* hook FD */
6974 static int bpf_link__detach_perf_event(struct bpf_link *link)
6976 struct bpf_link_fd *l = (void *)link;
6979 err = ioctl(l->fd, PERF_EVENT_IOC_DISABLE, 0);
6987 struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog,
6990 char errmsg[STRERR_BUFSIZE];
6991 struct bpf_link_fd *link;
6995 pr_warn("program '%s': invalid perf event FD %d\n",
6996 bpf_program__title(prog, false), pfd);
6997 return ERR_PTR(-EINVAL);
6999 prog_fd = bpf_program__fd(prog);
7001 pr_warn("program '%s': can't attach BPF program w/o FD (did you load it?)\n",
7002 bpf_program__title(prog, false));
7003 return ERR_PTR(-EINVAL);
7006 link = calloc(1, sizeof(*link));
7008 return ERR_PTR(-ENOMEM);
7009 link->link.detach = &bpf_link__detach_perf_event;
7012 if (ioctl(pfd, PERF_EVENT_IOC_SET_BPF, prog_fd) < 0) {
7015 pr_warn("program '%s': failed to attach to pfd %d: %s\n",
7016 bpf_program__title(prog, false), pfd,
7017 libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
7018 return ERR_PTR(err);
7020 if (ioctl(pfd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
7023 pr_warn("program '%s': failed to enable pfd %d: %s\n",
7024 bpf_program__title(prog, false), pfd,
7025 libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
7026 return ERR_PTR(err);
7028 return (struct bpf_link *)link;
7032 * this function is expected to parse integer in the range of [0, 2^31-1] from
7033 * given file using scanf format string fmt. If actual parsed value is
7034 * negative, the result might be indistinguishable from error
7036 static int parse_uint_from_file(const char *file, const char *fmt)
7038 char buf[STRERR_BUFSIZE];
7042 f = fopen(file, "r");
7045 pr_debug("failed to open '%s': %s\n", file,
7046 libbpf_strerror_r(err, buf, sizeof(buf)));
7049 err = fscanf(f, fmt, &ret);
7051 err = err == EOF ? -EIO : -errno;
7052 pr_debug("failed to parse '%s': %s\n", file,
7053 libbpf_strerror_r(err, buf, sizeof(buf)));
7061 static int determine_kprobe_perf_type(void)
7063 const char *file = "/sys/bus/event_source/devices/kprobe/type";
7065 return parse_uint_from_file(file, "%d\n");
7068 static int determine_uprobe_perf_type(void)
7070 const char *file = "/sys/bus/event_source/devices/uprobe/type";
7072 return parse_uint_from_file(file, "%d\n");
7075 static int determine_kprobe_retprobe_bit(void)
7077 const char *file = "/sys/bus/event_source/devices/kprobe/format/retprobe";
7079 return parse_uint_from_file(file, "config:%d\n");
7082 static int determine_uprobe_retprobe_bit(void)
7084 const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe";
7086 return parse_uint_from_file(file, "config:%d\n");
7089 static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
7090 uint64_t offset, int pid)
7092 struct perf_event_attr attr = {};
7093 char errmsg[STRERR_BUFSIZE];
7096 type = uprobe ? determine_uprobe_perf_type()
7097 : determine_kprobe_perf_type();
7099 pr_warn("failed to determine %s perf type: %s\n",
7100 uprobe ? "uprobe" : "kprobe",
7101 libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
7105 int bit = uprobe ? determine_uprobe_retprobe_bit()
7106 : determine_kprobe_retprobe_bit();
7109 pr_warn("failed to determine %s retprobe bit: %s\n",
7110 uprobe ? "uprobe" : "kprobe",
7111 libbpf_strerror_r(bit, errmsg, sizeof(errmsg)));
7114 attr.config |= 1 << bit;
7116 attr.size = sizeof(attr);
7118 attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */
7119 attr.config2 = offset; /* kprobe_addr or probe_offset */
7121 /* pid filter is meaningful only for uprobes */
7122 pfd = syscall(__NR_perf_event_open, &attr,
7123 pid < 0 ? -1 : pid /* pid */,
7124 pid == -1 ? 0 : -1 /* cpu */,
7125 -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
7128 pr_warn("%s perf_event_open() failed: %s\n",
7129 uprobe ? "uprobe" : "kprobe",
7130 libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
7136 struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
7138 const char *func_name)
7140 char errmsg[STRERR_BUFSIZE];
7141 struct bpf_link *link;
7144 pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name,
7145 0 /* offset */, -1 /* pid */);
7147 pr_warn("program '%s': failed to create %s '%s' perf event: %s\n",
7148 bpf_program__title(prog, false),
7149 retprobe ? "kretprobe" : "kprobe", func_name,
7150 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
7151 return ERR_PTR(pfd);
7153 link = bpf_program__attach_perf_event(prog, pfd);
7156 err = PTR_ERR(link);
7157 pr_warn("program '%s': failed to attach to %s '%s': %s\n",
7158 bpf_program__title(prog, false),
7159 retprobe ? "kretprobe" : "kprobe", func_name,
7160 libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
7166 static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
7167 struct bpf_program *prog)
7169 const char *func_name;
7172 func_name = bpf_program__title(prog, false) + sec->len;
7173 retprobe = strcmp(sec->sec, "kretprobe/") == 0;
7175 return bpf_program__attach_kprobe(prog, retprobe, func_name);
7178 struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,
7179 bool retprobe, pid_t pid,
7180 const char *binary_path,
7183 char errmsg[STRERR_BUFSIZE];
7184 struct bpf_link *link;
7187 pfd = perf_event_open_probe(true /* uprobe */, retprobe,
7188 binary_path, func_offset, pid);
7190 pr_warn("program '%s': failed to create %s '%s:0x%zx' perf event: %s\n",
7191 bpf_program__title(prog, false),
7192 retprobe ? "uretprobe" : "uprobe",
7193 binary_path, func_offset,
7194 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
7195 return ERR_PTR(pfd);
7197 link = bpf_program__attach_perf_event(prog, pfd);
7200 err = PTR_ERR(link);
7201 pr_warn("program '%s': failed to attach to %s '%s:0x%zx': %s\n",
7202 bpf_program__title(prog, false),
7203 retprobe ? "uretprobe" : "uprobe",
7204 binary_path, func_offset,
7205 libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
7211 static int determine_tracepoint_id(const char *tp_category,
7212 const char *tp_name)
7214 char file[PATH_MAX];
7217 ret = snprintf(file, sizeof(file),
7218 "/sys/kernel/debug/tracing/events/%s/%s/id",
7219 tp_category, tp_name);
7222 if (ret >= sizeof(file)) {
7223 pr_debug("tracepoint %s/%s path is too long\n",
7224 tp_category, tp_name);
7227 return parse_uint_from_file(file, "%d\n");
7230 static int perf_event_open_tracepoint(const char *tp_category,
7231 const char *tp_name)
7233 struct perf_event_attr attr = {};
7234 char errmsg[STRERR_BUFSIZE];
7235 int tp_id, pfd, err;
7237 tp_id = determine_tracepoint_id(tp_category, tp_name);
7239 pr_warn("failed to determine tracepoint '%s/%s' perf event ID: %s\n",
7240 tp_category, tp_name,
7241 libbpf_strerror_r(tp_id, errmsg, sizeof(errmsg)));
7245 attr.type = PERF_TYPE_TRACEPOINT;
7246 attr.size = sizeof(attr);
7247 attr.config = tp_id;
7249 pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */,
7250 -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC);
7253 pr_warn("tracepoint '%s/%s' perf_event_open() failed: %s\n",
7254 tp_category, tp_name,
7255 libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
7261 struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog,
7262 const char *tp_category,
7263 const char *tp_name)
7265 char errmsg[STRERR_BUFSIZE];
7266 struct bpf_link *link;
7269 pfd = perf_event_open_tracepoint(tp_category, tp_name);
7271 pr_warn("program '%s': failed to create tracepoint '%s/%s' perf event: %s\n",
7272 bpf_program__title(prog, false),
7273 tp_category, tp_name,
7274 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
7275 return ERR_PTR(pfd);
7277 link = bpf_program__attach_perf_event(prog, pfd);
7280 err = PTR_ERR(link);
7281 pr_warn("program '%s': failed to attach to tracepoint '%s/%s': %s\n",
7282 bpf_program__title(prog, false),
7283 tp_category, tp_name,
7284 libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
7290 static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
7291 struct bpf_program *prog)
7293 char *sec_name, *tp_cat, *tp_name;
7294 struct bpf_link *link;
7296 sec_name = strdup(bpf_program__title(prog, false));
7298 return ERR_PTR(-ENOMEM);
7300 /* extract "tp/<category>/<name>" */
7301 tp_cat = sec_name + sec->len;
7302 tp_name = strchr(tp_cat, '/');
7304 link = ERR_PTR(-EINVAL);
7310 link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name);
7316 static int bpf_link__detach_fd(struct bpf_link *link)
7318 struct bpf_link_fd *l = (void *)link;
7320 return close(l->fd);
7323 struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
7324 const char *tp_name)
7326 char errmsg[STRERR_BUFSIZE];
7327 struct bpf_link_fd *link;
7330 prog_fd = bpf_program__fd(prog);
7332 pr_warn("program '%s': can't attach before loaded\n",
7333 bpf_program__title(prog, false));
7334 return ERR_PTR(-EINVAL);
7337 link = calloc(1, sizeof(*link));
7339 return ERR_PTR(-ENOMEM);
7340 link->link.detach = &bpf_link__detach_fd;
7342 pfd = bpf_raw_tracepoint_open(tp_name, prog_fd);
7346 pr_warn("program '%s': failed to attach to raw tracepoint '%s': %s\n",
7347 bpf_program__title(prog, false), tp_name,
7348 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
7349 return ERR_PTR(pfd);
7352 return (struct bpf_link *)link;
7355 static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
7356 struct bpf_program *prog)
7358 const char *tp_name = bpf_program__title(prog, false) + sec->len;
7360 return bpf_program__attach_raw_tracepoint(prog, tp_name);
7363 struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
7365 char errmsg[STRERR_BUFSIZE];
7366 struct bpf_link_fd *link;
7369 prog_fd = bpf_program__fd(prog);
7371 pr_warn("program '%s': can't attach before loaded\n",
7372 bpf_program__title(prog, false));
7373 return ERR_PTR(-EINVAL);
7376 link = calloc(1, sizeof(*link));
7378 return ERR_PTR(-ENOMEM);
7379 link->link.detach = &bpf_link__detach_fd;
7381 pfd = bpf_raw_tracepoint_open(NULL, prog_fd);
7385 pr_warn("program '%s': failed to attach to trace: %s\n",
7386 bpf_program__title(prog, false),
7387 libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
7388 return ERR_PTR(pfd);
7391 return (struct bpf_link *)link;
7394 static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
7395 struct bpf_program *prog)
7397 return bpf_program__attach_trace(prog);
7400 struct bpf_link *bpf_program__attach(struct bpf_program *prog)
7402 const struct bpf_sec_def *sec_def;
7404 sec_def = find_sec_def(bpf_program__title(prog, false));
7405 if (!sec_def || !sec_def->attach_fn)
7406 return ERR_PTR(-ESRCH);
7408 return sec_def->attach_fn(sec_def, prog);
7411 static int bpf_link__detach_struct_ops(struct bpf_link *link)
7413 struct bpf_link_fd *l = (void *)link;
7416 if (bpf_map_delete_elem(l->fd, &zero))
7422 struct bpf_link *bpf_map__attach_struct_ops(struct bpf_map *map)
7424 struct bpf_struct_ops *st_ops;
7425 struct bpf_link_fd *link;
7429 if (!bpf_map__is_struct_ops(map) || map->fd == -1)
7430 return ERR_PTR(-EINVAL);
7432 link = calloc(1, sizeof(*link));
7434 return ERR_PTR(-EINVAL);
7436 st_ops = map->st_ops;
7437 for (i = 0; i < btf_vlen(st_ops->type); i++) {
7438 struct bpf_program *prog = st_ops->progs[i];
7445 prog_fd = bpf_program__fd(prog);
7446 kern_data = st_ops->kern_vdata + st_ops->kern_func_off[i];
7447 *(unsigned long *)kern_data = prog_fd;
7450 err = bpf_map_update_elem(map->fd, &zero, st_ops->kern_vdata, 0);
7454 return ERR_PTR(err);
7457 link->link.detach = bpf_link__detach_struct_ops;
7460 return (struct bpf_link *)link;
7463 enum bpf_perf_event_ret
7464 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
7465 void **copy_mem, size_t *copy_size,
7466 bpf_perf_event_print_t fn, void *private_data)
7468 struct perf_event_mmap_page *header = mmap_mem;
7469 __u64 data_head = ring_buffer_read_head(header);
7470 __u64 data_tail = header->data_tail;
7471 void *base = ((__u8 *)header) + page_size;
7472 int ret = LIBBPF_PERF_EVENT_CONT;
7473 struct perf_event_header *ehdr;
7476 while (data_head != data_tail) {
7477 ehdr = base + (data_tail & (mmap_size - 1));
7478 ehdr_size = ehdr->size;
7480 if (((void *)ehdr) + ehdr_size > base + mmap_size) {
7481 void *copy_start = ehdr;
7482 size_t len_first = base + mmap_size - copy_start;
7483 size_t len_secnd = ehdr_size - len_first;
7485 if (*copy_size < ehdr_size) {
7487 *copy_mem = malloc(ehdr_size);
7490 ret = LIBBPF_PERF_EVENT_ERROR;
7493 *copy_size = ehdr_size;
7496 memcpy(*copy_mem, copy_start, len_first);
7497 memcpy(*copy_mem + len_first, base, len_secnd);
7501 ret = fn(ehdr, private_data);
7502 data_tail += ehdr_size;
7503 if (ret != LIBBPF_PERF_EVENT_CONT)
7507 ring_buffer_write_tail(header, data_tail);
7513 struct perf_buffer_params {
7514 struct perf_event_attr *attr;
7515 /* if event_cb is specified, it takes precendence */
7516 perf_buffer_event_fn event_cb;
7517 /* sample_cb and lost_cb are higher-level common-case callbacks */
7518 perf_buffer_sample_fn sample_cb;
7519 perf_buffer_lost_fn lost_cb;
7526 struct perf_cpu_buf {
7527 struct perf_buffer *pb;
7528 void *base; /* mmap()'ed memory */
7529 void *buf; /* for reconstructing segmented data */
7536 struct perf_buffer {
7537 perf_buffer_event_fn event_cb;
7538 perf_buffer_sample_fn sample_cb;
7539 perf_buffer_lost_fn lost_cb;
7540 void *ctx; /* passed into callbacks */
7544 struct perf_cpu_buf **cpu_bufs;
7545 struct epoll_event *events;
7546 int cpu_cnt; /* number of allocated CPU buffers */
7547 int epoll_fd; /* perf event FD */
7548 int map_fd; /* BPF_MAP_TYPE_PERF_EVENT_ARRAY BPF map FD */
7551 static void perf_buffer__free_cpu_buf(struct perf_buffer *pb,
7552 struct perf_cpu_buf *cpu_buf)
7556 if (cpu_buf->base &&
7557 munmap(cpu_buf->base, pb->mmap_size + pb->page_size))
7558 pr_warn("failed to munmap cpu_buf #%d\n", cpu_buf->cpu);
7559 if (cpu_buf->fd >= 0) {
7560 ioctl(cpu_buf->fd, PERF_EVENT_IOC_DISABLE, 0);
7567 void perf_buffer__free(struct perf_buffer *pb)
7574 for (i = 0; i < pb->cpu_cnt && pb->cpu_bufs[i]; i++) {
7575 struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
7577 bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key);
7578 perf_buffer__free_cpu_buf(pb, cpu_buf);
7582 if (pb->epoll_fd >= 0)
7583 close(pb->epoll_fd);
7588 static struct perf_cpu_buf *
7589 perf_buffer__open_cpu_buf(struct perf_buffer *pb, struct perf_event_attr *attr,
7590 int cpu, int map_key)
7592 struct perf_cpu_buf *cpu_buf;
7593 char msg[STRERR_BUFSIZE];
7596 cpu_buf = calloc(1, sizeof(*cpu_buf));
7598 return ERR_PTR(-ENOMEM);
7602 cpu_buf->map_key = map_key;
7604 cpu_buf->fd = syscall(__NR_perf_event_open, attr, -1 /* pid */, cpu,
7605 -1, PERF_FLAG_FD_CLOEXEC);
7606 if (cpu_buf->fd < 0) {
7608 pr_warn("failed to open perf buffer event on cpu #%d: %s\n",
7609 cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
7613 cpu_buf->base = mmap(NULL, pb->mmap_size + pb->page_size,
7614 PROT_READ | PROT_WRITE, MAP_SHARED,
7616 if (cpu_buf->base == MAP_FAILED) {
7617 cpu_buf->base = NULL;
7619 pr_warn("failed to mmap perf buffer on cpu #%d: %s\n",
7620 cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
7624 if (ioctl(cpu_buf->fd, PERF_EVENT_IOC_ENABLE, 0) < 0) {
7626 pr_warn("failed to enable perf buffer event on cpu #%d: %s\n",
7627 cpu, libbpf_strerror_r(err, msg, sizeof(msg)));
7634 perf_buffer__free_cpu_buf(pb, cpu_buf);
7635 return (struct perf_cpu_buf *)ERR_PTR(err);
7638 static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
7639 struct perf_buffer_params *p);
7641 struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt,
7642 const struct perf_buffer_opts *opts)
7644 struct perf_buffer_params p = {};
7645 struct perf_event_attr attr = { 0, };
7647 attr.config = PERF_COUNT_SW_BPF_OUTPUT,
7648 attr.type = PERF_TYPE_SOFTWARE;
7649 attr.sample_type = PERF_SAMPLE_RAW;
7650 attr.sample_period = 1;
7651 attr.wakeup_events = 1;
7654 p.sample_cb = opts ? opts->sample_cb : NULL;
7655 p.lost_cb = opts ? opts->lost_cb : NULL;
7656 p.ctx = opts ? opts->ctx : NULL;
7658 return __perf_buffer__new(map_fd, page_cnt, &p);
7661 struct perf_buffer *
7662 perf_buffer__new_raw(int map_fd, size_t page_cnt,
7663 const struct perf_buffer_raw_opts *opts)
7665 struct perf_buffer_params p = {};
7667 p.attr = opts->attr;
7668 p.event_cb = opts->event_cb;
7670 p.cpu_cnt = opts->cpu_cnt;
7671 p.cpus = opts->cpus;
7672 p.map_keys = opts->map_keys;
7674 return __perf_buffer__new(map_fd, page_cnt, &p);
7677 static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt,
7678 struct perf_buffer_params *p)
7680 const char *online_cpus_file = "/sys/devices/system/cpu/online";
7681 struct bpf_map_info map = {};
7682 char msg[STRERR_BUFSIZE];
7683 struct perf_buffer *pb;
7684 bool *online = NULL;
7688 if (page_cnt & (page_cnt - 1)) {
7689 pr_warn("page count should be power of two, but is %zu\n",
7691 return ERR_PTR(-EINVAL);
7694 map_info_len = sizeof(map);
7695 err = bpf_obj_get_info_by_fd(map_fd, &map, &map_info_len);
7698 pr_warn("failed to get map info for map FD %d: %s\n",
7699 map_fd, libbpf_strerror_r(err, msg, sizeof(msg)));
7700 return ERR_PTR(err);
7703 if (map.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
7704 pr_warn("map '%s' should be BPF_MAP_TYPE_PERF_EVENT_ARRAY\n",
7706 return ERR_PTR(-EINVAL);
7709 pb = calloc(1, sizeof(*pb));
7711 return ERR_PTR(-ENOMEM);
7713 pb->event_cb = p->event_cb;
7714 pb->sample_cb = p->sample_cb;
7715 pb->lost_cb = p->lost_cb;
7718 pb->page_size = getpagesize();
7719 pb->mmap_size = pb->page_size * page_cnt;
7720 pb->map_fd = map_fd;
7722 pb->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
7723 if (pb->epoll_fd < 0) {
7725 pr_warn("failed to create epoll instance: %s\n",
7726 libbpf_strerror_r(err, msg, sizeof(msg)));
7730 if (p->cpu_cnt > 0) {
7731 pb->cpu_cnt = p->cpu_cnt;
7733 pb->cpu_cnt = libbpf_num_possible_cpus();
7734 if (pb->cpu_cnt < 0) {
7738 if (map.max_entries < pb->cpu_cnt)
7739 pb->cpu_cnt = map.max_entries;
7742 pb->events = calloc(pb->cpu_cnt, sizeof(*pb->events));
7745 pr_warn("failed to allocate events: out of memory\n");
7748 pb->cpu_bufs = calloc(pb->cpu_cnt, sizeof(*pb->cpu_bufs));
7749 if (!pb->cpu_bufs) {
7751 pr_warn("failed to allocate buffers: out of memory\n");
7755 err = parse_cpu_mask_file(online_cpus_file, &online, &n);
7757 pr_warn("failed to get online CPU mask: %d\n", err);
7761 for (i = 0, j = 0; i < pb->cpu_cnt; i++) {
7762 struct perf_cpu_buf *cpu_buf;
7765 cpu = p->cpu_cnt > 0 ? p->cpus[i] : i;
7766 map_key = p->cpu_cnt > 0 ? p->map_keys[i] : i;
7768 /* in case user didn't explicitly requested particular CPUs to
7769 * be attached to, skip offline/not present CPUs
7771 if (p->cpu_cnt <= 0 && (cpu >= n || !online[cpu]))
7774 cpu_buf = perf_buffer__open_cpu_buf(pb, p->attr, cpu, map_key);
7775 if (IS_ERR(cpu_buf)) {
7776 err = PTR_ERR(cpu_buf);
7780 pb->cpu_bufs[j] = cpu_buf;
7782 err = bpf_map_update_elem(pb->map_fd, &map_key,
7786 pr_warn("failed to set cpu #%d, key %d -> perf FD %d: %s\n",
7787 cpu, map_key, cpu_buf->fd,
7788 libbpf_strerror_r(err, msg, sizeof(msg)));
7792 pb->events[j].events = EPOLLIN;
7793 pb->events[j].data.ptr = cpu_buf;
7794 if (epoll_ctl(pb->epoll_fd, EPOLL_CTL_ADD, cpu_buf->fd,
7795 &pb->events[j]) < 0) {
7797 pr_warn("failed to epoll_ctl cpu #%d perf FD %d: %s\n",
7799 libbpf_strerror_r(err, msg, sizeof(msg)));
7812 perf_buffer__free(pb);
7813 return ERR_PTR(err);
7816 struct perf_sample_raw {
7817 struct perf_event_header header;
7822 struct perf_sample_lost {
7823 struct perf_event_header header;
7829 static enum bpf_perf_event_ret
7830 perf_buffer__process_record(struct perf_event_header *e, void *ctx)
7832 struct perf_cpu_buf *cpu_buf = ctx;
7833 struct perf_buffer *pb = cpu_buf->pb;
7836 /* user wants full control over parsing perf event */
7838 return pb->event_cb(pb->ctx, cpu_buf->cpu, e);
7841 case PERF_RECORD_SAMPLE: {
7842 struct perf_sample_raw *s = data;
7845 pb->sample_cb(pb->ctx, cpu_buf->cpu, s->data, s->size);
7848 case PERF_RECORD_LOST: {
7849 struct perf_sample_lost *s = data;
7852 pb->lost_cb(pb->ctx, cpu_buf->cpu, s->lost);
7856 pr_warn("unknown perf sample type %d\n", e->type);
7857 return LIBBPF_PERF_EVENT_ERROR;
7859 return LIBBPF_PERF_EVENT_CONT;
7862 static int perf_buffer__process_records(struct perf_buffer *pb,
7863 struct perf_cpu_buf *cpu_buf)
7865 enum bpf_perf_event_ret ret;
7867 ret = bpf_perf_event_read_simple(cpu_buf->base, pb->mmap_size,
7868 pb->page_size, &cpu_buf->buf,
7870 perf_buffer__process_record, cpu_buf);
7871 if (ret != LIBBPF_PERF_EVENT_CONT)
7876 int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms)
7880 cnt = epoll_wait(pb->epoll_fd, pb->events, pb->cpu_cnt, timeout_ms);
7881 for (i = 0; i < cnt; i++) {
7882 struct perf_cpu_buf *cpu_buf = pb->events[i].data.ptr;
7884 err = perf_buffer__process_records(pb, cpu_buf);
7886 pr_warn("error while processing records: %d\n", err);
7890 return cnt < 0 ? -errno : cnt;
7893 struct bpf_prog_info_array_desc {
7894 int array_offset; /* e.g. offset of jited_prog_insns */
7895 int count_offset; /* e.g. offset of jited_prog_len */
7896 int size_offset; /* > 0: offset of rec size,
7897 * < 0: fix size of -size_offset
7901 static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = {
7902 [BPF_PROG_INFO_JITED_INSNS] = {
7903 offsetof(struct bpf_prog_info, jited_prog_insns),
7904 offsetof(struct bpf_prog_info, jited_prog_len),
7907 [BPF_PROG_INFO_XLATED_INSNS] = {
7908 offsetof(struct bpf_prog_info, xlated_prog_insns),
7909 offsetof(struct bpf_prog_info, xlated_prog_len),
7912 [BPF_PROG_INFO_MAP_IDS] = {
7913 offsetof(struct bpf_prog_info, map_ids),
7914 offsetof(struct bpf_prog_info, nr_map_ids),
7915 -(int)sizeof(__u32),
7917 [BPF_PROG_INFO_JITED_KSYMS] = {
7918 offsetof(struct bpf_prog_info, jited_ksyms),
7919 offsetof(struct bpf_prog_info, nr_jited_ksyms),
7920 -(int)sizeof(__u64),
7922 [BPF_PROG_INFO_JITED_FUNC_LENS] = {
7923 offsetof(struct bpf_prog_info, jited_func_lens),
7924 offsetof(struct bpf_prog_info, nr_jited_func_lens),
7925 -(int)sizeof(__u32),
7927 [BPF_PROG_INFO_FUNC_INFO] = {
7928 offsetof(struct bpf_prog_info, func_info),
7929 offsetof(struct bpf_prog_info, nr_func_info),
7930 offsetof(struct bpf_prog_info, func_info_rec_size),
7932 [BPF_PROG_INFO_LINE_INFO] = {
7933 offsetof(struct bpf_prog_info, line_info),
7934 offsetof(struct bpf_prog_info, nr_line_info),
7935 offsetof(struct bpf_prog_info, line_info_rec_size),
7937 [BPF_PROG_INFO_JITED_LINE_INFO] = {
7938 offsetof(struct bpf_prog_info, jited_line_info),
7939 offsetof(struct bpf_prog_info, nr_jited_line_info),
7940 offsetof(struct bpf_prog_info, jited_line_info_rec_size),
7942 [BPF_PROG_INFO_PROG_TAGS] = {
7943 offsetof(struct bpf_prog_info, prog_tags),
7944 offsetof(struct bpf_prog_info, nr_prog_tags),
7945 -(int)sizeof(__u8) * BPF_TAG_SIZE,
7950 static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info,
7953 __u32 *array = (__u32 *)info;
7956 return array[offset / sizeof(__u32)];
7957 return -(int)offset;
7960 static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info,
7963 __u64 *array = (__u64 *)info;
7966 return array[offset / sizeof(__u64)];
7967 return -(int)offset;
7970 static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
7973 __u32 *array = (__u32 *)info;
7976 array[offset / sizeof(__u32)] = val;
7979 static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
7982 __u64 *array = (__u64 *)info;
7985 array[offset / sizeof(__u64)] = val;
7988 struct bpf_prog_info_linear *
7989 bpf_program__get_prog_info_linear(int fd, __u64 arrays)
7991 struct bpf_prog_info_linear *info_linear;
7992 struct bpf_prog_info info = {};
7993 __u32 info_len = sizeof(info);
7998 if (arrays >> BPF_PROG_INFO_LAST_ARRAY)
7999 return ERR_PTR(-EINVAL);
8001 /* step 1: get array dimensions */
8002 err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
8004 pr_debug("can't get prog info: %s", strerror(errno));
8005 return ERR_PTR(-EFAULT);
8008 /* step 2: calculate total size of all arrays */
8009 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
8010 bool include_array = (arrays & (1UL << i)) > 0;
8011 struct bpf_prog_info_array_desc *desc;
8014 desc = bpf_prog_info_array_desc + i;
8016 /* kernel is too old to support this field */
8017 if (info_len < desc->array_offset + sizeof(__u32) ||
8018 info_len < desc->count_offset + sizeof(__u32) ||
8019 (desc->size_offset > 0 && info_len < desc->size_offset))
8020 include_array = false;
8022 if (!include_array) {
8023 arrays &= ~(1UL << i); /* clear the bit */
8027 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
8028 size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
8030 data_len += count * size;
8033 /* step 3: allocate continuous memory */
8034 data_len = roundup(data_len, sizeof(__u64));
8035 info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len);
8037 return ERR_PTR(-ENOMEM);
8039 /* step 4: fill data to info_linear->info */
8040 info_linear->arrays = arrays;
8041 memset(&info_linear->info, 0, sizeof(info));
8042 ptr = info_linear->data;
8044 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
8045 struct bpf_prog_info_array_desc *desc;
8048 if ((arrays & (1UL << i)) == 0)
8051 desc = bpf_prog_info_array_desc + i;
8052 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
8053 size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
8054 bpf_prog_info_set_offset_u32(&info_linear->info,
8055 desc->count_offset, count);
8056 bpf_prog_info_set_offset_u32(&info_linear->info,
8057 desc->size_offset, size);
8058 bpf_prog_info_set_offset_u64(&info_linear->info,
8061 ptr += count * size;
8064 /* step 5: call syscall again to get required arrays */
8065 err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
8067 pr_debug("can't get prog info: %s", strerror(errno));
8069 return ERR_PTR(-EFAULT);
8072 /* step 6: verify the data */
8073 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
8074 struct bpf_prog_info_array_desc *desc;
8077 if ((arrays & (1UL << i)) == 0)
8080 desc = bpf_prog_info_array_desc + i;
8081 v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
8082 v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
8083 desc->count_offset);
8085 pr_warn("%s: mismatch in element count\n", __func__);
8087 v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
8088 v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
8091 pr_warn("%s: mismatch in rec size\n", __func__);
8094 /* step 7: update info_len and data_len */
8095 info_linear->info_len = sizeof(struct bpf_prog_info);
8096 info_linear->data_len = data_len;
8101 void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear)
8105 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
8106 struct bpf_prog_info_array_desc *desc;
8109 if ((info_linear->arrays & (1UL << i)) == 0)
8112 desc = bpf_prog_info_array_desc + i;
8113 addr = bpf_prog_info_read_offset_u64(&info_linear->info,
8114 desc->array_offset);
8115 offs = addr - ptr_to_u64(info_linear->data);
8116 bpf_prog_info_set_offset_u64(&info_linear->info,
8117 desc->array_offset, offs);
8121 void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear)
8125 for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
8126 struct bpf_prog_info_array_desc *desc;
8129 if ((info_linear->arrays & (1UL << i)) == 0)
8132 desc = bpf_prog_info_array_desc + i;
8133 offs = bpf_prog_info_read_offset_u64(&info_linear->info,
8134 desc->array_offset);
8135 addr = offs + ptr_to_u64(info_linear->data);
8136 bpf_prog_info_set_offset_u64(&info_linear->info,
8137 desc->array_offset, addr);
8141 int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz)
8143 int err = 0, n, len, start, end = -1;
8149 /* Each sub string separated by ',' has format \d+-\d+ or \d+ */
8151 if (*s == ',' || *s == '\n') {
8155 n = sscanf(s, "%d%n-%d%n", &start, &len, &end, &len);
8156 if (n <= 0 || n > 2) {
8157 pr_warn("Failed to get CPU range %s: %d\n", s, n);
8160 } else if (n == 1) {
8163 if (start < 0 || start > end) {
8164 pr_warn("Invalid CPU range [%d,%d] in %s\n",
8169 tmp = realloc(*mask, end + 1);
8175 memset(tmp + *mask_sz, 0, start - *mask_sz);
8176 memset(tmp + start, 1, end - start + 1);
8181 pr_warn("Empty CPU range\n");
8191 int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz)
8193 int fd, err = 0, len;
8196 fd = open(fcpu, O_RDONLY);
8199 pr_warn("Failed to open cpu mask file %s: %d\n", fcpu, err);
8202 len = read(fd, buf, sizeof(buf));
8205 err = len ? -errno : -EINVAL;
8206 pr_warn("Failed to read cpu mask from %s: %d\n", fcpu, err);
8209 if (len >= sizeof(buf)) {
8210 pr_warn("CPU mask is too big in file %s\n", fcpu);
8215 return parse_cpu_mask_str(buf, mask, mask_sz);
8218 int libbpf_num_possible_cpus(void)
8220 static const char *fcpu = "/sys/devices/system/cpu/possible";
8222 int err, n, i, tmp_cpus;
8225 tmp_cpus = READ_ONCE(cpus);
8229 err = parse_cpu_mask_file(fcpu, &mask, &n);
8234 for (i = 0; i < n; i++) {
8240 WRITE_ONCE(cpus, tmp_cpus);
8244 int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
8245 const struct bpf_object_open_opts *opts)
8247 DECLARE_LIBBPF_OPTS(bpf_object_open_opts, skel_opts,
8248 .object_name = s->name,
8250 struct bpf_object *obj;
8253 /* Attempt to preserve opts->object_name, unless overriden by user
8254 * explicitly. Overwriting object name for skeletons is discouraged,
8255 * as it breaks global data maps, because they contain object name
8256 * prefix as their own map name prefix. When skeleton is generated,
8257 * bpftool is making an assumption that this name will stay the same.
8260 memcpy(&skel_opts, opts, sizeof(*opts));
8261 if (!opts->object_name)
8262 skel_opts.object_name = s->name;
8265 obj = bpf_object__open_mem(s->data, s->data_sz, &skel_opts);
8267 pr_warn("failed to initialize skeleton BPF object '%s': %ld\n",
8268 s->name, PTR_ERR(obj));
8269 return PTR_ERR(obj);
8274 for (i = 0; i < s->map_cnt; i++) {
8275 struct bpf_map **map = s->maps[i].map;
8276 const char *name = s->maps[i].name;
8277 void **mmaped = s->maps[i].mmaped;
8279 *map = bpf_object__find_map_by_name(obj, name);
8281 pr_warn("failed to find skeleton map '%s'\n", name);
8285 /* externs shouldn't be pre-setup from user code */
8286 if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG)
8287 *mmaped = (*map)->mmaped;
8290 for (i = 0; i < s->prog_cnt; i++) {
8291 struct bpf_program **prog = s->progs[i].prog;
8292 const char *name = s->progs[i].name;
8294 *prog = bpf_object__find_program_by_name(obj, name);
8296 pr_warn("failed to find skeleton program '%s'\n", name);
8304 int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
8308 err = bpf_object__load(*s->obj);
8310 pr_warn("failed to load BPF skeleton '%s': %d\n", s->name, err);
8314 for (i = 0; i < s->map_cnt; i++) {
8315 struct bpf_map *map = *s->maps[i].map;
8316 size_t mmap_sz = bpf_map_mmap_sz(map);
8317 int prot, map_fd = bpf_map__fd(map);
8318 void **mmaped = s->maps[i].mmaped;
8323 if (!(map->def.map_flags & BPF_F_MMAPABLE)) {
8328 if (map->def.map_flags & BPF_F_RDONLY_PROG)
8331 prot = PROT_READ | PROT_WRITE;
8333 /* Remap anonymous mmap()-ed "map initialization image" as
8334 * a BPF map-backed mmap()-ed memory, but preserving the same
8335 * memory address. This will cause kernel to change process'
8336 * page table to point to a different piece of kernel memory,
8337 * but from userspace point of view memory address (and its
8338 * contents, being identical at this point) will stay the
8339 * same. This mapping will be released by bpf_object__close()
8340 * as per normal clean up procedure, so we don't need to worry
8341 * about it from skeleton's clean up perspective.
8343 *mmaped = mmap(map->mmaped, mmap_sz, prot,
8344 MAP_SHARED | MAP_FIXED, map_fd, 0);
8345 if (*mmaped == MAP_FAILED) {
8348 pr_warn("failed to re-mmap() map '%s': %d\n",
8349 bpf_map__name(map), err);
8357 int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
8361 for (i = 0; i < s->prog_cnt; i++) {
8362 struct bpf_program *prog = *s->progs[i].prog;
8363 struct bpf_link **link = s->progs[i].link;
8364 const struct bpf_sec_def *sec_def;
8365 const char *sec_name = bpf_program__title(prog, false);
8367 sec_def = find_sec_def(sec_name);
8368 if (!sec_def || !sec_def->attach_fn)
8371 *link = sec_def->attach_fn(sec_def, prog);
8372 if (IS_ERR(*link)) {
8373 pr_warn("failed to auto-attach program '%s': %ld\n",
8374 bpf_program__name(prog), PTR_ERR(*link));
8375 return PTR_ERR(*link);
8382 void bpf_object__detach_skeleton(struct bpf_object_skeleton *s)
8386 for (i = 0; i < s->prog_cnt; i++) {
8387 struct bpf_link **link = s->progs[i].link;
8389 if (!IS_ERR_OR_NULL(*link))
8390 bpf_link__destroy(*link);
8395 void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s)
8398 bpf_object__detach_skeleton(s);
8400 bpf_object__close(*s->obj);