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-rw-r--r--tools/bpf/bpftool/btf.c1095
1 files changed, 1095 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
new file mode 100644
index 000000000..68a70ac03
--- /dev/null
+++ b/tools/bpf/bpftool/btf.c
@@ -0,0 +1,1095 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright (C) 2019 Facebook */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/err.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/btf.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include <bpf/hashmap.h>
+#include <bpf/libbpf.h>
+
+#include "json_writer.h"
+#include "main.h"
+
+static const char * const btf_kind_str[NR_BTF_KINDS] = {
+ [BTF_KIND_UNKN] = "UNKNOWN",
+ [BTF_KIND_INT] = "INT",
+ [BTF_KIND_PTR] = "PTR",
+ [BTF_KIND_ARRAY] = "ARRAY",
+ [BTF_KIND_STRUCT] = "STRUCT",
+ [BTF_KIND_UNION] = "UNION",
+ [BTF_KIND_ENUM] = "ENUM",
+ [BTF_KIND_FWD] = "FWD",
+ [BTF_KIND_TYPEDEF] = "TYPEDEF",
+ [BTF_KIND_VOLATILE] = "VOLATILE",
+ [BTF_KIND_CONST] = "CONST",
+ [BTF_KIND_RESTRICT] = "RESTRICT",
+ [BTF_KIND_FUNC] = "FUNC",
+ [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
+ [BTF_KIND_VAR] = "VAR",
+ [BTF_KIND_DATASEC] = "DATASEC",
+ [BTF_KIND_FLOAT] = "FLOAT",
+ [BTF_KIND_DECL_TAG] = "DECL_TAG",
+ [BTF_KIND_TYPE_TAG] = "TYPE_TAG",
+ [BTF_KIND_ENUM64] = "ENUM64",
+};
+
+static const char *btf_int_enc_str(__u8 encoding)
+{
+ switch (encoding) {
+ case 0:
+ return "(none)";
+ case BTF_INT_SIGNED:
+ return "SIGNED";
+ case BTF_INT_CHAR:
+ return "CHAR";
+ case BTF_INT_BOOL:
+ return "BOOL";
+ default:
+ return "UNKN";
+ }
+}
+
+static const char *btf_var_linkage_str(__u32 linkage)
+{
+ switch (linkage) {
+ case BTF_VAR_STATIC:
+ return "static";
+ case BTF_VAR_GLOBAL_ALLOCATED:
+ return "global";
+ case BTF_VAR_GLOBAL_EXTERN:
+ return "extern";
+ default:
+ return "(unknown)";
+ }
+}
+
+static const char *btf_func_linkage_str(const struct btf_type *t)
+{
+ switch (btf_vlen(t)) {
+ case BTF_FUNC_STATIC:
+ return "static";
+ case BTF_FUNC_GLOBAL:
+ return "global";
+ case BTF_FUNC_EXTERN:
+ return "extern";
+ default:
+ return "(unknown)";
+ }
+}
+
+static const char *btf_str(const struct btf *btf, __u32 off)
+{
+ if (!off)
+ return "(anon)";
+ return btf__name_by_offset(btf, off) ? : "(invalid)";
+}
+
+static int btf_kind_safe(int kind)
+{
+ return kind <= BTF_KIND_MAX ? kind : BTF_KIND_UNKN;
+}
+
+static int dump_btf_type(const struct btf *btf, __u32 id,
+ const struct btf_type *t)
+{
+ json_writer_t *w = json_wtr;
+ int kind = btf_kind(t);
+
+ if (json_output) {
+ jsonw_start_object(w);
+ jsonw_uint_field(w, "id", id);
+ jsonw_string_field(w, "kind", btf_kind_str[btf_kind_safe(kind)]);
+ jsonw_string_field(w, "name", btf_str(btf, t->name_off));
+ } else {
+ printf("[%u] %s '%s'", id, btf_kind_str[btf_kind_safe(kind)],
+ btf_str(btf, t->name_off));
+ }
+
+ switch (kind) {
+ case BTF_KIND_INT: {
+ __u32 v = *(__u32 *)(t + 1);
+ const char *enc;
+
+ enc = btf_int_enc_str(BTF_INT_ENCODING(v));
+
+ if (json_output) {
+ jsonw_uint_field(w, "size", t->size);
+ jsonw_uint_field(w, "bits_offset", BTF_INT_OFFSET(v));
+ jsonw_uint_field(w, "nr_bits", BTF_INT_BITS(v));
+ jsonw_string_field(w, "encoding", enc);
+ } else {
+ printf(" size=%u bits_offset=%u nr_bits=%u encoding=%s",
+ t->size, BTF_INT_OFFSET(v), BTF_INT_BITS(v),
+ enc);
+ }
+ break;
+ }
+ case BTF_KIND_PTR:
+ case BTF_KIND_CONST:
+ case BTF_KIND_VOLATILE:
+ case BTF_KIND_RESTRICT:
+ case BTF_KIND_TYPEDEF:
+ case BTF_KIND_TYPE_TAG:
+ if (json_output)
+ jsonw_uint_field(w, "type_id", t->type);
+ else
+ printf(" type_id=%u", t->type);
+ break;
+ case BTF_KIND_ARRAY: {
+ const struct btf_array *arr = (const void *)(t + 1);
+
+ if (json_output) {
+ jsonw_uint_field(w, "type_id", arr->type);
+ jsonw_uint_field(w, "index_type_id", arr->index_type);
+ jsonw_uint_field(w, "nr_elems", arr->nelems);
+ } else {
+ printf(" type_id=%u index_type_id=%u nr_elems=%u",
+ arr->type, arr->index_type, arr->nelems);
+ }
+ break;
+ }
+ case BTF_KIND_STRUCT:
+ case BTF_KIND_UNION: {
+ const struct btf_member *m = (const void *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+ int i;
+
+ if (json_output) {
+ jsonw_uint_field(w, "size", t->size);
+ jsonw_uint_field(w, "vlen", vlen);
+ jsonw_name(w, "members");
+ jsonw_start_array(w);
+ } else {
+ printf(" size=%u vlen=%u", t->size, vlen);
+ }
+ for (i = 0; i < vlen; i++, m++) {
+ const char *name = btf_str(btf, m->name_off);
+ __u32 bit_off, bit_sz;
+
+ if (BTF_INFO_KFLAG(t->info)) {
+ bit_off = BTF_MEMBER_BIT_OFFSET(m->offset);
+ bit_sz = BTF_MEMBER_BITFIELD_SIZE(m->offset);
+ } else {
+ bit_off = m->offset;
+ bit_sz = 0;
+ }
+
+ if (json_output) {
+ jsonw_start_object(w);
+ jsonw_string_field(w, "name", name);
+ jsonw_uint_field(w, "type_id", m->type);
+ jsonw_uint_field(w, "bits_offset", bit_off);
+ if (bit_sz) {
+ jsonw_uint_field(w, "bitfield_size",
+ bit_sz);
+ }
+ jsonw_end_object(w);
+ } else {
+ printf("\n\t'%s' type_id=%u bits_offset=%u",
+ name, m->type, bit_off);
+ if (bit_sz)
+ printf(" bitfield_size=%u", bit_sz);
+ }
+ }
+ if (json_output)
+ jsonw_end_array(w);
+ break;
+ }
+ case BTF_KIND_ENUM: {
+ const struct btf_enum *v = (const void *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+ const char *encoding;
+ int i;
+
+ encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
+ if (json_output) {
+ jsonw_string_field(w, "encoding", encoding);
+ jsonw_uint_field(w, "size", t->size);
+ jsonw_uint_field(w, "vlen", vlen);
+ jsonw_name(w, "values");
+ jsonw_start_array(w);
+ } else {
+ printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
+ }
+ for (i = 0; i < vlen; i++, v++) {
+ const char *name = btf_str(btf, v->name_off);
+
+ if (json_output) {
+ jsonw_start_object(w);
+ jsonw_string_field(w, "name", name);
+ if (btf_kflag(t))
+ jsonw_int_field(w, "val", v->val);
+ else
+ jsonw_uint_field(w, "val", v->val);
+ jsonw_end_object(w);
+ } else {
+ if (btf_kflag(t))
+ printf("\n\t'%s' val=%d", name, v->val);
+ else
+ printf("\n\t'%s' val=%u", name, v->val);
+ }
+ }
+ if (json_output)
+ jsonw_end_array(w);
+ break;
+ }
+ case BTF_KIND_ENUM64: {
+ const struct btf_enum64 *v = btf_enum64(t);
+ __u16 vlen = btf_vlen(t);
+ const char *encoding;
+ int i;
+
+ encoding = btf_kflag(t) ? "SIGNED" : "UNSIGNED";
+ if (json_output) {
+ jsonw_string_field(w, "encoding", encoding);
+ jsonw_uint_field(w, "size", t->size);
+ jsonw_uint_field(w, "vlen", vlen);
+ jsonw_name(w, "values");
+ jsonw_start_array(w);
+ } else {
+ printf(" encoding=%s size=%u vlen=%u", encoding, t->size, vlen);
+ }
+ for (i = 0; i < vlen; i++, v++) {
+ const char *name = btf_str(btf, v->name_off);
+ __u64 val = ((__u64)v->val_hi32 << 32) | v->val_lo32;
+
+ if (json_output) {
+ jsonw_start_object(w);
+ jsonw_string_field(w, "name", name);
+ if (btf_kflag(t))
+ jsonw_int_field(w, "val", val);
+ else
+ jsonw_uint_field(w, "val", val);
+ jsonw_end_object(w);
+ } else {
+ if (btf_kflag(t))
+ printf("\n\t'%s' val=%lldLL", name,
+ (unsigned long long)val);
+ else
+ printf("\n\t'%s' val=%lluULL", name,
+ (unsigned long long)val);
+ }
+ }
+ if (json_output)
+ jsonw_end_array(w);
+ break;
+ }
+ case BTF_KIND_FWD: {
+ const char *fwd_kind = BTF_INFO_KFLAG(t->info) ? "union"
+ : "struct";
+
+ if (json_output)
+ jsonw_string_field(w, "fwd_kind", fwd_kind);
+ else
+ printf(" fwd_kind=%s", fwd_kind);
+ break;
+ }
+ case BTF_KIND_FUNC: {
+ const char *linkage = btf_func_linkage_str(t);
+
+ if (json_output) {
+ jsonw_uint_field(w, "type_id", t->type);
+ jsonw_string_field(w, "linkage", linkage);
+ } else {
+ printf(" type_id=%u linkage=%s", t->type, linkage);
+ }
+ break;
+ }
+ case BTF_KIND_FUNC_PROTO: {
+ const struct btf_param *p = (const void *)(t + 1);
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+ int i;
+
+ if (json_output) {
+ jsonw_uint_field(w, "ret_type_id", t->type);
+ jsonw_uint_field(w, "vlen", vlen);
+ jsonw_name(w, "params");
+ jsonw_start_array(w);
+ } else {
+ printf(" ret_type_id=%u vlen=%u", t->type, vlen);
+ }
+ for (i = 0; i < vlen; i++, p++) {
+ const char *name = btf_str(btf, p->name_off);
+
+ if (json_output) {
+ jsonw_start_object(w);
+ jsonw_string_field(w, "name", name);
+ jsonw_uint_field(w, "type_id", p->type);
+ jsonw_end_object(w);
+ } else {
+ printf("\n\t'%s' type_id=%u", name, p->type);
+ }
+ }
+ if (json_output)
+ jsonw_end_array(w);
+ break;
+ }
+ case BTF_KIND_VAR: {
+ const struct btf_var *v = (const void *)(t + 1);
+ const char *linkage;
+
+ linkage = btf_var_linkage_str(v->linkage);
+
+ if (json_output) {
+ jsonw_uint_field(w, "type_id", t->type);
+ jsonw_string_field(w, "linkage", linkage);
+ } else {
+ printf(" type_id=%u, linkage=%s", t->type, linkage);
+ }
+ break;
+ }
+ case BTF_KIND_DATASEC: {
+ const struct btf_var_secinfo *v = (const void *)(t + 1);
+ const struct btf_type *vt;
+ __u16 vlen = BTF_INFO_VLEN(t->info);
+ int i;
+
+ if (json_output) {
+ jsonw_uint_field(w, "size", t->size);
+ jsonw_uint_field(w, "vlen", vlen);
+ jsonw_name(w, "vars");
+ jsonw_start_array(w);
+ } else {
+ printf(" size=%u vlen=%u", t->size, vlen);
+ }
+ for (i = 0; i < vlen; i++, v++) {
+ if (json_output) {
+ jsonw_start_object(w);
+ jsonw_uint_field(w, "type_id", v->type);
+ jsonw_uint_field(w, "offset", v->offset);
+ jsonw_uint_field(w, "size", v->size);
+ jsonw_end_object(w);
+ } else {
+ printf("\n\ttype_id=%u offset=%u size=%u",
+ v->type, v->offset, v->size);
+
+ if (v->type < btf__type_cnt(btf)) {
+ vt = btf__type_by_id(btf, v->type);
+ printf(" (%s '%s')",
+ btf_kind_str[btf_kind_safe(btf_kind(vt))],
+ btf_str(btf, vt->name_off));
+ }
+ }
+ }
+ if (json_output)
+ jsonw_end_array(w);
+ break;
+ }
+ case BTF_KIND_FLOAT: {
+ if (json_output)
+ jsonw_uint_field(w, "size", t->size);
+ else
+ printf(" size=%u", t->size);
+ break;
+ }
+ case BTF_KIND_DECL_TAG: {
+ const struct btf_decl_tag *tag = (const void *)(t + 1);
+
+ if (json_output) {
+ jsonw_uint_field(w, "type_id", t->type);
+ jsonw_int_field(w, "component_idx", tag->component_idx);
+ } else {
+ printf(" type_id=%u component_idx=%d", t->type, tag->component_idx);
+ }
+ break;
+ }
+ default:
+ break;
+ }
+
+ if (json_output)
+ jsonw_end_object(json_wtr);
+ else
+ printf("\n");
+
+ return 0;
+}
+
+static int dump_btf_raw(const struct btf *btf,
+ __u32 *root_type_ids, int root_type_cnt)
+{
+ const struct btf_type *t;
+ int i;
+
+ if (json_output) {
+ jsonw_start_object(json_wtr);
+ jsonw_name(json_wtr, "types");
+ jsonw_start_array(json_wtr);
+ }
+
+ if (root_type_cnt) {
+ for (i = 0; i < root_type_cnt; i++) {
+ t = btf__type_by_id(btf, root_type_ids[i]);
+ dump_btf_type(btf, root_type_ids[i], t);
+ }
+ } else {
+ const struct btf *base;
+ int cnt = btf__type_cnt(btf);
+ int start_id = 1;
+
+ base = btf__base_btf(btf);
+ if (base)
+ start_id = btf__type_cnt(base);
+
+ for (i = start_id; i < cnt; i++) {
+ t = btf__type_by_id(btf, i);
+ dump_btf_type(btf, i, t);
+ }
+ }
+
+ if (json_output) {
+ jsonw_end_array(json_wtr);
+ jsonw_end_object(json_wtr);
+ }
+ return 0;
+}
+
+static void __printf(2, 0) btf_dump_printf(void *ctx,
+ const char *fmt, va_list args)
+{
+ vfprintf(stdout, fmt, args);
+}
+
+static int dump_btf_c(const struct btf *btf,
+ __u32 *root_type_ids, int root_type_cnt)
+{
+ struct btf_dump *d;
+ int err = 0, i;
+
+ d = btf_dump__new(btf, btf_dump_printf, NULL, NULL);
+ err = libbpf_get_error(d);
+ if (err)
+ return err;
+
+ printf("#ifndef __VMLINUX_H__\n");
+ printf("#define __VMLINUX_H__\n");
+ printf("\n");
+ printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
+ printf("#pragma clang attribute push (__attribute__((preserve_access_index)), apply_to = record)\n");
+ printf("#endif\n\n");
+
+ if (root_type_cnt) {
+ for (i = 0; i < root_type_cnt; i++) {
+ err = btf_dump__dump_type(d, root_type_ids[i]);
+ if (err)
+ goto done;
+ }
+ } else {
+ int cnt = btf__type_cnt(btf);
+
+ for (i = 1; i < cnt; i++) {
+ err = btf_dump__dump_type(d, i);
+ if (err)
+ goto done;
+ }
+ }
+
+ printf("#ifndef BPF_NO_PRESERVE_ACCESS_INDEX\n");
+ printf("#pragma clang attribute pop\n");
+ printf("#endif\n");
+ printf("\n");
+ printf("#endif /* __VMLINUX_H__ */\n");
+
+done:
+ btf_dump__free(d);
+ return err;
+}
+
+static const char sysfs_vmlinux[] = "/sys/kernel/btf/vmlinux";
+
+static struct btf *get_vmlinux_btf_from_sysfs(void)
+{
+ struct btf *base;
+
+ base = btf__parse(sysfs_vmlinux, NULL);
+ if (libbpf_get_error(base)) {
+ p_err("failed to parse vmlinux BTF at '%s': %ld\n",
+ sysfs_vmlinux, libbpf_get_error(base));
+ base = NULL;
+ }
+
+ return base;
+}
+
+#define BTF_NAME_BUFF_LEN 64
+
+static bool btf_is_kernel_module(__u32 btf_id)
+{
+ struct bpf_btf_info btf_info = {};
+ char btf_name[BTF_NAME_BUFF_LEN];
+ int btf_fd;
+ __u32 len;
+ int err;
+
+ btf_fd = bpf_btf_get_fd_by_id(btf_id);
+ if (btf_fd < 0) {
+ p_err("can't get BTF object by id (%u): %s", btf_id, strerror(errno));
+ return false;
+ }
+
+ len = sizeof(btf_info);
+ btf_info.name = ptr_to_u64(btf_name);
+ btf_info.name_len = sizeof(btf_name);
+ err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len);
+ close(btf_fd);
+ if (err) {
+ p_err("can't get BTF (ID %u) object info: %s", btf_id, strerror(errno));
+ return false;
+ }
+
+ return btf_info.kernel_btf && strncmp(btf_name, "vmlinux", sizeof(btf_name)) != 0;
+}
+
+static int do_dump(int argc, char **argv)
+{
+ struct btf *btf = NULL, *base = NULL;
+ __u32 root_type_ids[2];
+ int root_type_cnt = 0;
+ bool dump_c = false;
+ __u32 btf_id = -1;
+ const char *src;
+ int fd = -1;
+ int err;
+
+ if (!REQ_ARGS(2)) {
+ usage();
+ return -1;
+ }
+ src = GET_ARG();
+ if (is_prefix(src, "map")) {
+ struct bpf_map_info info = {};
+ __u32 len = sizeof(info);
+
+ if (!REQ_ARGS(2)) {
+ usage();
+ return -1;
+ }
+
+ fd = map_parse_fd_and_info(&argc, &argv, &info, &len);
+ if (fd < 0)
+ return -1;
+
+ btf_id = info.btf_id;
+ if (argc && is_prefix(*argv, "key")) {
+ root_type_ids[root_type_cnt++] = info.btf_key_type_id;
+ NEXT_ARG();
+ } else if (argc && is_prefix(*argv, "value")) {
+ root_type_ids[root_type_cnt++] = info.btf_value_type_id;
+ NEXT_ARG();
+ } else if (argc && is_prefix(*argv, "all")) {
+ NEXT_ARG();
+ } else if (argc && is_prefix(*argv, "kv")) {
+ root_type_ids[root_type_cnt++] = info.btf_key_type_id;
+ root_type_ids[root_type_cnt++] = info.btf_value_type_id;
+ NEXT_ARG();
+ } else {
+ root_type_ids[root_type_cnt++] = info.btf_key_type_id;
+ root_type_ids[root_type_cnt++] = info.btf_value_type_id;
+ }
+ } else if (is_prefix(src, "prog")) {
+ struct bpf_prog_info info = {};
+ __u32 len = sizeof(info);
+
+ if (!REQ_ARGS(2)) {
+ usage();
+ return -1;
+ }
+
+ fd = prog_parse_fd(&argc, &argv);
+ if (fd < 0)
+ return -1;
+
+ err = bpf_obj_get_info_by_fd(fd, &info, &len);
+ if (err) {
+ p_err("can't get prog info: %s", strerror(errno));
+ goto done;
+ }
+
+ btf_id = info.btf_id;
+ } else if (is_prefix(src, "id")) {
+ char *endptr;
+
+ btf_id = strtoul(*argv, &endptr, 0);
+ if (*endptr) {
+ p_err("can't parse %s as ID", *argv);
+ return -1;
+ }
+ NEXT_ARG();
+ } else if (is_prefix(src, "file")) {
+ const char sysfs_prefix[] = "/sys/kernel/btf/";
+
+ if (!base_btf &&
+ strncmp(*argv, sysfs_prefix, sizeof(sysfs_prefix) - 1) == 0 &&
+ strcmp(*argv, sysfs_vmlinux) != 0)
+ base = get_vmlinux_btf_from_sysfs();
+
+ btf = btf__parse_split(*argv, base ?: base_btf);
+ err = libbpf_get_error(btf);
+ if (!btf) {
+ p_err("failed to load BTF from %s: %s",
+ *argv, strerror(errno));
+ goto done;
+ }
+ NEXT_ARG();
+ } else {
+ err = -1;
+ p_err("unrecognized BTF source specifier: '%s'", src);
+ goto done;
+ }
+
+ while (argc) {
+ if (is_prefix(*argv, "format")) {
+ NEXT_ARG();
+ if (argc < 1) {
+ p_err("expecting value for 'format' option\n");
+ err = -EINVAL;
+ goto done;
+ }
+ if (strcmp(*argv, "c") == 0) {
+ dump_c = true;
+ } else if (strcmp(*argv, "raw") == 0) {
+ dump_c = false;
+ } else {
+ p_err("unrecognized format specifier: '%s', possible values: raw, c",
+ *argv);
+ err = -EINVAL;
+ goto done;
+ }
+ NEXT_ARG();
+ } else {
+ p_err("unrecognized option: '%s'", *argv);
+ err = -EINVAL;
+ goto done;
+ }
+ }
+
+ if (!btf) {
+ if (!base_btf && btf_is_kernel_module(btf_id)) {
+ p_info("Warning: valid base BTF was not specified with -B option, falling back to standard base BTF (%s)",
+ sysfs_vmlinux);
+ base_btf = get_vmlinux_btf_from_sysfs();
+ }
+
+ btf = btf__load_from_kernel_by_id_split(btf_id, base_btf);
+ err = libbpf_get_error(btf);
+ if (!btf) {
+ p_err("get btf by id (%u): %s", btf_id, strerror(errno));
+ goto done;
+ }
+ }
+
+ if (dump_c) {
+ if (json_output) {
+ p_err("JSON output for C-syntax dump is not supported");
+ err = -ENOTSUP;
+ goto done;
+ }
+ err = dump_btf_c(btf, root_type_ids, root_type_cnt);
+ } else {
+ err = dump_btf_raw(btf, root_type_ids, root_type_cnt);
+ }
+
+done:
+ close(fd);
+ btf__free(btf);
+ btf__free(base);
+ return err;
+}
+
+static int btf_parse_fd(int *argc, char ***argv)
+{
+ unsigned int id;
+ char *endptr;
+ int fd;
+
+ if (!is_prefix(*argv[0], "id")) {
+ p_err("expected 'id', got: '%s'?", **argv);
+ return -1;
+ }
+ NEXT_ARGP();
+
+ id = strtoul(**argv, &endptr, 0);
+ if (*endptr) {
+ p_err("can't parse %s as ID", **argv);
+ return -1;
+ }
+ NEXT_ARGP();
+
+ fd = bpf_btf_get_fd_by_id(id);
+ if (fd < 0)
+ p_err("can't get BTF object by id (%u): %s",
+ id, strerror(errno));
+
+ return fd;
+}
+
+static int
+build_btf_type_table(struct hashmap *tab, enum bpf_obj_type type,
+ void *info, __u32 *len)
+{
+ static const char * const names[] = {
+ [BPF_OBJ_UNKNOWN] = "unknown",
+ [BPF_OBJ_PROG] = "prog",
+ [BPF_OBJ_MAP] = "map",
+ };
+ __u32 btf_id, id = 0;
+ int err;
+ int fd;
+
+ while (true) {
+ switch (type) {
+ case BPF_OBJ_PROG:
+ err = bpf_prog_get_next_id(id, &id);
+ break;
+ case BPF_OBJ_MAP:
+ err = bpf_map_get_next_id(id, &id);
+ break;
+ default:
+ err = -1;
+ p_err("unexpected object type: %d", type);
+ goto err_free;
+ }
+ if (err) {
+ if (errno == ENOENT) {
+ err = 0;
+ break;
+ }
+ p_err("can't get next %s: %s%s", names[type],
+ strerror(errno),
+ errno == EINVAL ? " -- kernel too old?" : "");
+ goto err_free;
+ }
+
+ switch (type) {
+ case BPF_OBJ_PROG:
+ fd = bpf_prog_get_fd_by_id(id);
+ break;
+ case BPF_OBJ_MAP:
+ fd = bpf_map_get_fd_by_id(id);
+ break;
+ default:
+ err = -1;
+ p_err("unexpected object type: %d", type);
+ goto err_free;
+ }
+ if (fd < 0) {
+ if (errno == ENOENT)
+ continue;
+ p_err("can't get %s by id (%u): %s", names[type], id,
+ strerror(errno));
+ err = -1;
+ goto err_free;
+ }
+
+ memset(info, 0, *len);
+ err = bpf_obj_get_info_by_fd(fd, info, len);
+ close(fd);
+ if (err) {
+ p_err("can't get %s info: %s", names[type],
+ strerror(errno));
+ goto err_free;
+ }
+
+ switch (type) {
+ case BPF_OBJ_PROG:
+ btf_id = ((struct bpf_prog_info *)info)->btf_id;
+ break;
+ case BPF_OBJ_MAP:
+ btf_id = ((struct bpf_map_info *)info)->btf_id;
+ break;
+ default:
+ err = -1;
+ p_err("unexpected object type: %d", type);
+ goto err_free;
+ }
+ if (!btf_id)
+ continue;
+
+ err = hashmap__append(tab, u32_as_hash_field(btf_id),
+ u32_as_hash_field(id));
+ if (err) {
+ p_err("failed to append entry to hashmap for BTF ID %u, object ID %u: %s",
+ btf_id, id, strerror(-err));
+ goto err_free;
+ }
+ }
+
+ return 0;
+
+err_free:
+ hashmap__free(tab);
+ return err;
+}
+
+static int
+build_btf_tables(struct hashmap *btf_prog_table,
+ struct hashmap *btf_map_table)
+{
+ struct bpf_prog_info prog_info;
+ __u32 prog_len = sizeof(prog_info);
+ struct bpf_map_info map_info;
+ __u32 map_len = sizeof(map_info);
+ int err = 0;
+
+ err = build_btf_type_table(btf_prog_table, BPF_OBJ_PROG, &prog_info,
+ &prog_len);
+ if (err)
+ return err;
+
+ err = build_btf_type_table(btf_map_table, BPF_OBJ_MAP, &map_info,
+ &map_len);
+ if (err) {
+ hashmap__free(btf_prog_table);
+ return err;
+ }
+
+ return 0;
+}
+
+static void
+show_btf_plain(struct bpf_btf_info *info, int fd,
+ struct hashmap *btf_prog_table,
+ struct hashmap *btf_map_table)
+{
+ struct hashmap_entry *entry;
+ const char *name = u64_to_ptr(info->name);
+ int n;
+
+ printf("%u: ", info->id);
+ if (info->kernel_btf)
+ printf("name [%s] ", name);
+ else if (name && name[0])
+ printf("name %s ", name);
+ else
+ printf("name <anon> ");
+ printf("size %uB", info->btf_size);
+
+ n = 0;
+ hashmap__for_each_key_entry(btf_prog_table, entry,
+ u32_as_hash_field(info->id)) {
+ printf("%s%u", n++ == 0 ? " prog_ids " : ",",
+ hash_field_as_u32(entry->value));
+ }
+
+ n = 0;
+ hashmap__for_each_key_entry(btf_map_table, entry,
+ u32_as_hash_field(info->id)) {
+ printf("%s%u", n++ == 0 ? " map_ids " : ",",
+ hash_field_as_u32(entry->value));
+ }
+
+ emit_obj_refs_plain(refs_table, info->id, "\n\tpids ");
+
+ printf("\n");
+}
+
+static void
+show_btf_json(struct bpf_btf_info *info, int fd,
+ struct hashmap *btf_prog_table,
+ struct hashmap *btf_map_table)
+{
+ struct hashmap_entry *entry;
+ const char *name = u64_to_ptr(info->name);
+
+ jsonw_start_object(json_wtr); /* btf object */
+ jsonw_uint_field(json_wtr, "id", info->id);
+ jsonw_uint_field(json_wtr, "size", info->btf_size);
+
+ jsonw_name(json_wtr, "prog_ids");
+ jsonw_start_array(json_wtr); /* prog_ids */
+ hashmap__for_each_key_entry(btf_prog_table, entry,
+ u32_as_hash_field(info->id)) {
+ jsonw_uint(json_wtr, hash_field_as_u32(entry->value));
+ }
+ jsonw_end_array(json_wtr); /* prog_ids */
+
+ jsonw_name(json_wtr, "map_ids");
+ jsonw_start_array(json_wtr); /* map_ids */
+ hashmap__for_each_key_entry(btf_map_table, entry,
+ u32_as_hash_field(info->id)) {
+ jsonw_uint(json_wtr, hash_field_as_u32(entry->value));
+ }
+ jsonw_end_array(json_wtr); /* map_ids */
+
+ emit_obj_refs_json(refs_table, info->id, json_wtr); /* pids */
+
+ jsonw_bool_field(json_wtr, "kernel", info->kernel_btf);
+
+ if (name && name[0])
+ jsonw_string_field(json_wtr, "name", name);
+
+ jsonw_end_object(json_wtr); /* btf object */
+}
+
+static int
+show_btf(int fd, struct hashmap *btf_prog_table,
+ struct hashmap *btf_map_table)
+{
+ struct bpf_btf_info info;
+ __u32 len = sizeof(info);
+ char name[64];
+ int err;
+
+ memset(&info, 0, sizeof(info));
+ err = bpf_obj_get_info_by_fd(fd, &info, &len);
+ if (err) {
+ p_err("can't get BTF object info: %s", strerror(errno));
+ return -1;
+ }
+ /* if kernel support emitting BTF object name, pass name pointer */
+ if (info.name_len) {
+ memset(&info, 0, sizeof(info));
+ info.name_len = sizeof(name);
+ info.name = ptr_to_u64(name);
+ len = sizeof(info);
+
+ err = bpf_obj_get_info_by_fd(fd, &info, &len);
+ if (err) {
+ p_err("can't get BTF object info: %s", strerror(errno));
+ return -1;
+ }
+ }
+
+ if (json_output)
+ show_btf_json(&info, fd, btf_prog_table, btf_map_table);
+ else
+ show_btf_plain(&info, fd, btf_prog_table, btf_map_table);
+
+ return 0;
+}
+
+static int do_show(int argc, char **argv)
+{
+ struct hashmap *btf_prog_table;
+ struct hashmap *btf_map_table;
+ int err, fd = -1;
+ __u32 id = 0;
+
+ if (argc == 2) {
+ fd = btf_parse_fd(&argc, &argv);
+ if (fd < 0)
+ return -1;
+ }
+
+ if (argc) {
+ if (fd >= 0)
+ close(fd);
+ return BAD_ARG();
+ }
+
+ btf_prog_table = hashmap__new(hash_fn_for_key_as_id,
+ equal_fn_for_key_as_id, NULL);
+ btf_map_table = hashmap__new(hash_fn_for_key_as_id,
+ equal_fn_for_key_as_id, NULL);
+ if (IS_ERR(btf_prog_table) || IS_ERR(btf_map_table)) {
+ hashmap__free(btf_prog_table);
+ hashmap__free(btf_map_table);
+ if (fd >= 0)
+ close(fd);
+ p_err("failed to create hashmap for object references");
+ return -1;
+ }
+ err = build_btf_tables(btf_prog_table, btf_map_table);
+ if (err) {
+ if (fd >= 0)
+ close(fd);
+ return err;
+ }
+ build_obj_refs_table(&refs_table, BPF_OBJ_BTF);
+
+ if (fd >= 0) {
+ err = show_btf(fd, btf_prog_table, btf_map_table);
+ close(fd);
+ goto exit_free;
+ }
+
+ if (json_output)
+ jsonw_start_array(json_wtr); /* root array */
+
+ while (true) {
+ err = bpf_btf_get_next_id(id, &id);
+ if (err) {
+ if (errno == ENOENT) {
+ err = 0;
+ break;
+ }
+ p_err("can't get next BTF object: %s%s",
+ strerror(errno),
+ errno == EINVAL ? " -- kernel too old?" : "");
+ err = -1;
+ break;
+ }
+
+ fd = bpf_btf_get_fd_by_id(id);
+ if (fd < 0) {
+ if (errno == ENOENT)
+ continue;
+ p_err("can't get BTF object by id (%u): %s",
+ id, strerror(errno));
+ err = -1;
+ break;
+ }
+
+ err = show_btf(fd, btf_prog_table, btf_map_table);
+ close(fd);
+ if (err)
+ break;
+ }
+
+ if (json_output)
+ jsonw_end_array(json_wtr); /* root array */
+
+exit_free:
+ hashmap__free(btf_prog_table);
+ hashmap__free(btf_map_table);
+ delete_obj_refs_table(refs_table);
+
+ return err;
+}
+
+static int do_help(int argc, char **argv)
+{
+ if (json_output) {
+ jsonw_null(json_wtr);
+ return 0;
+ }
+
+ fprintf(stderr,
+ "Usage: %1$s %2$s { show | list } [id BTF_ID]\n"
+ " %1$s %2$s dump BTF_SRC [format FORMAT]\n"
+ " %1$s %2$s help\n"
+ "\n"
+ " BTF_SRC := { id BTF_ID | prog PROG | map MAP [{key | value | kv | all}] | file FILE }\n"
+ " FORMAT := { raw | c }\n"
+ " " HELP_SPEC_MAP "\n"
+ " " HELP_SPEC_PROGRAM "\n"
+ " " HELP_SPEC_OPTIONS " |\n"
+ " {-B|--base-btf} }\n"
+ "",
+ bin_name, "btf");
+
+ return 0;
+}
+
+static const struct cmd cmds[] = {
+ { "show", do_show },
+ { "list", do_show },
+ { "help", do_help },
+ { "dump", do_dump },
+ { 0 }
+};
+
+int do_btf(int argc, char **argv)
+{
+ return cmd_select(cmds, argc, argv, do_help);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-10 13:38:56 +0000