2022-01-12 09:27 UTC-0500 ~ Mauricio Vásquez <mauricio@xxxxxxxxxx> > 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(-) > > diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c > index 905ab0ee6542..cef0ea99d4d9 100644 > +static int btfgen(const char *src_btf, const char *dst_btf, const char *objspaths[]) > +{ > + struct btfgen_info *info; > + struct btf *btf_new = NULL; > + int err; > + > + 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]); p_info() > + > + 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); p_info()