On Fri, Oct 25, 2024 at 9:15 AM Alan Maguire <alan.maguire@xxxxxxxxxx> wrote: > > On 25/10/2024 17:09, Alexei Starovoitov wrote: > > On Thu, Oct 24, 2024 at 4:26 PM Andrii Nakryiko > > <andrii.nakryiko@xxxxxxxxx> wrote: > >> > >>> > >>> The good news is that already happens, provided you have the updated > >>> pahole to handle distilled base generation. After building selftests I see > >>> > >>> $ objdump -h bpf_testmod.ko |grep BTF > >>> 7 .BTF_ids 000001c8 0000000000000000 0000000000000000 00002c50 > >>> 2**0 > >>> 50 .BTF 000036f4 0000000000000000 0000000000000000 0006e048 > >>> 2**0 > >>> 51 .BTF.base 000004cc 0000000000000000 0000000000000000 0007173c > >>> 2**0 > >>> > >> > >> Indeed, after updating to the latest pahole master now I get > >> .BTF.base, very nice. > > > > I pulled the latest pahole, rebuilt everything, > > but still cannot get it to generate BTF.base. > > > > Any special trick needed? > > Hmm, should just work for bpf_testmod.ko as long as "pahole > --supported_btf_features" reports "distilled_base" among the set of > features. scripts/Makefile.btf should add that feature if KBUILD_EXTMOD > is set, as it should be in the case of building bpf_testmod.ko. I'll > double-check at my end with latest bpf-next, but it was working > yesterday for me. There must be something else necessary: pahole -J -j --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func,decl_tag_kfuncs --lang_exclude=rust --btf_features=distilled_base --btf_base vmlinux .../bpf/bpf_testmod/bpf_testmod.ko; .../resolve_btfids -b vmlinux .../selftests/bpf/bpf_testmod/bpf_testmod.ko; objdump -h .../testing/selftests/bpf/bpf_testmod/bpf_testmod.ko|grep BTF 7 .BTF_ids 000001c8 0000000000000000 0000000000000000 00001d94 2**0 50 .BTF 00002ea7 0000000000000000 0000000000000000 00062e30 2**0
