forked from luck/tmp_suning_uos_patched
libbpf: Add btf__parse_raw() and generic btf__parse() APIs
Add public APIs to parse BTF from raw data file (e.g., /sys/kernel/btf/vmlinux), as well as generic btf__parse(), which will try to determine correct format, currently either raw or ELF. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200802013219.864880-2-andriin@fb.com
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@ -562,6 +562,83 @@ struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext)
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return btf;
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}
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struct btf *btf__parse_raw(const char *path)
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{
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void *data = NULL;
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struct btf *btf;
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FILE *f = NULL;
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__u16 magic;
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int err = 0;
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long sz;
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f = fopen(path, "rb");
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if (!f) {
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err = -errno;
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goto err_out;
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}
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/* check BTF magic */
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if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) {
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err = -EIO;
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goto err_out;
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}
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if (magic != BTF_MAGIC) {
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/* definitely not a raw BTF */
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err = -EPROTO;
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goto err_out;
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}
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/* get file size */
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if (fseek(f, 0, SEEK_END)) {
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err = -errno;
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goto err_out;
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}
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sz = ftell(f);
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if (sz < 0) {
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err = -errno;
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goto err_out;
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}
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/* rewind to the start */
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if (fseek(f, 0, SEEK_SET)) {
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err = -errno;
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goto err_out;
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}
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/* pre-alloc memory and read all of BTF data */
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data = malloc(sz);
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if (!data) {
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err = -ENOMEM;
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goto err_out;
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}
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if (fread(data, 1, sz, f) < sz) {
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err = -EIO;
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goto err_out;
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}
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/* finally parse BTF data */
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btf = btf__new(data, sz);
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err_out:
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free(data);
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if (f)
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fclose(f);
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return err ? ERR_PTR(err) : btf;
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}
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struct btf *btf__parse(const char *path, struct btf_ext **btf_ext)
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{
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struct btf *btf;
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if (btf_ext)
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*btf_ext = NULL;
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btf = btf__parse_raw(path);
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if (!IS_ERR(btf) || PTR_ERR(btf) != -EPROTO)
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return btf;
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return btf__parse_elf(path, btf_ext);
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}
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static int compare_vsi_off(const void *_a, const void *_b)
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{
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const struct btf_var_secinfo *a = _a;
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@ -2951,41 +3028,6 @@ static int btf_dedup_remap_types(struct btf_dedup *d)
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return 0;
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}
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static struct btf *btf_load_raw(const char *path)
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{
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struct btf *btf;
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size_t read_cnt;
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struct stat st;
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void *data;
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FILE *f;
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if (stat(path, &st))
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return ERR_PTR(-errno);
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data = malloc(st.st_size);
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if (!data)
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return ERR_PTR(-ENOMEM);
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f = fopen(path, "rb");
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if (!f) {
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btf = ERR_PTR(-errno);
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goto cleanup;
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}
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read_cnt = fread(data, 1, st.st_size, f);
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fclose(f);
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if (read_cnt < st.st_size) {
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btf = ERR_PTR(-EBADF);
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goto cleanup;
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}
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btf = btf__new(data, read_cnt);
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cleanup:
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free(data);
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return btf;
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}
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/*
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* Probe few well-known locations for vmlinux kernel image and try to load BTF
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* data out of it to use for target BTF.
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@ -3021,7 +3063,7 @@ struct btf *libbpf_find_kernel_btf(void)
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continue;
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if (locations[i].raw_btf)
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btf = btf_load_raw(path);
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btf = btf__parse_raw(path);
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else
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btf = btf__parse_elf(path, NULL);
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@ -64,8 +64,9 @@ struct btf_ext_header {
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LIBBPF_API void btf__free(struct btf *btf);
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LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
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LIBBPF_API struct btf *btf__parse_elf(const char *path,
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struct btf_ext **btf_ext);
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LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
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LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
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LIBBPF_API struct btf *btf__parse_raw(const char *path);
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LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
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LIBBPF_API int btf__load(struct btf *btf);
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LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
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@ -293,5 +293,7 @@ LIBBPF_0.1.0 {
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bpf_program__is_sk_lookup;
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bpf_program__set_autoload;
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bpf_program__set_sk_lookup;
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btf__parse;
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btf__parse_raw;
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btf__set_fd;
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} LIBBPF_0.0.9;
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