On Sun, Jan 12, 2020 at 8:33 PM Zong Li [off-list ref] wrote:

I'm not quite familiar with btf, so I have no idea why there are two
weak symbols be added in 8580ac9404f6 ("bpf: Process in-kernel BTF")

I can explain what these weak symbols are for, but that won't change
the fact that compiler or linker are buggy. The weak symbols should work
in all cases and compiler should pick correct relocation.
In this case it sounds that compiler picked relative relocation and failed
to reach zero from that address.