Hi everyone,
I'm trying to build 5.13.2 selftests for github.com/cilium/ci-kernels.
With clang-12:
libbpf: failed to find BTF for extern 'tcp_reno_cong_avoid' [38] section: -2
Error: failed to open BPF object file: No such file or directory
libbpf: failed to find BTF for extern 'tcp_cong_avoid_ai' [27] section: -2
Error: failed to open BPF object file: No such file or directory
Arnaldo has hit this problem before:
https://www.spinics.net/lists/dwarves/msg01332.html So I tried to
recompile with clang-13 (Ubuntu clang version
13.0.0-++20210629083512+c4de78e91c93-1~exp1~20210629184258.496):
libbpf: ELF relo #0 in section #15 has unexpected type 2 in
/home/lorenz/dev/ci-kernels/build/linux-5.13.2/tools/testing/selftests/bpf/bpf_cubic.o
Aka my clang-12 is too old, my clang-13 is too new. In the past we've
stubbed out some tests based on clang version, can we do the same
here?
This build breakage tends to happen with every major kernel release.
Is there a way to avoid this? FWIW some CI builds fail because of
this, however I have no idea where these reports go / why they aren't
taken into account: https://lkml.org/lkml/2021/6/22/987
It would be nice if there was some combination of (easily available
clang release) x (stable kernel versions) that allows to compile BPF
selftests successfully.
Lorenz
--
Lorenz Bauer | Systems Engineer
6th Floor, County Hall/The Riverside Building, SE1 7PB, UK
www.cloudflare.com
