failed to validate module

[andrey-admin]

After compiling last code tree - got that messages in dmesg:

[Tue Sep 5 10:53:29 2023] tcp_htcp: module verification failed: signature and/or required key missing - tainting kernel
[Tue Sep 5 10:53:29 2023] BPF: [129365] Invalid name_offset:2322721
[Tue Sep 5 10:53:29 2023] failed to validate module [tcp_htcp] BTF: -22
[Tue Sep 5 10:53:29 2023] BPF: Invalid name_offset:2322721
[Tue Sep 5 10:53:29 2023] failed to validate module [tcp_dctcp] BTF: -22

Distro: Ubuntu 22.04.3 LTS
Kernel: 6.2.0-1011-gcp

[alan-maguire]

this is a kernel issue rather than a bpftune one. When modules are built at different times than the underlying kernel, this causes a problem because the base BTF in the core kernel (vmlinux) and the module (tcp_htcp in this case) do not work together; the module BTF refers to the underlying core kernel BTF in its descriptions, and these are not compatible.

upstream there are future plans to resolve this by allowing modules to build standalone BTF, but for now the assumption is that kernel+module BTF are built together and should work together.