On Wed, Jan 12, 2022 at 6:27 AM Mauricio Vásquez <mauricio@xxxxxxxxxx> wrote:
>
> btfgen() receives the path of a source and destination BTF files and a
> list of BPF objects. This function records the relocations for all
> objects and then generates the BTF file by calling btfgen_get_btf()
> (implemented in the following commits).
>
> btfgen_record_obj() loads the BTF and BTF.ext sections of the BPF
> objects and loops through all CO-RE relocations. It uses
> bpf_core_calc_relo_insn() from libbpf and passes the target spec to
> btfgen_record_reloc() that saves the types involved in such relocation.
>
> Signed-off-by: Mauricio Vásquez <mauricio@xxxxxxxxxx>
> Signed-off-by: Rafael David Tinoco <rafael.tinoco@xxxxxxxxxxx>
> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@xxxxxxxxxx>
> Signed-off-by: Leonardo Di Donato <leonardo.didonato@xxxxxxxxxx>
> ---
> tools/bpf/bpftool/gen.c | 221 +++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 219 insertions(+), 2 deletions(-)
>
[...]
> + info = btfgen_new_info(src_btf);
> + if (!info) {
> + p_err("failed to allocate info structure: %s", strerror(errno));
> + err = -errno;
> + goto out;
> + }
> +
> + for (int i = 0; objspaths[i] != NULL; i++) {
> + printf("OBJ : %s\n", objspaths[i]);
same as in previous patches, OBJ, DBTF, that's quite cryptic. Is this
used for some parsing of the output or it's just debugging leftovers?
> +
> + err = btfgen_record_obj(info, objspaths[i]);
> + if (err)
> + goto out;
> + }
> +
> + btf_new = btfgen_get_btf(info);
> + if (!btf_new) {
> + err = -errno;
> + p_err("error generating btf: %s", strerror(errno));
> + goto out;
> + }
> +
> + printf("DBTF: %s\n", dst_btf);
> + err = btf_save_raw(btf_new, dst_btf);
> + if (err) {
> + p_err("error saving btf file: %s", strerror(errno));
> + goto out;
> + }
> +
> +out:
> + btf__free(btf_new);
> + btfgen_free_info(info);
> +
> + return err;
> +}
> +
> static int is_file(const char *path)
> {
> struct stat st;
> --
> 2.25.1
>
