Re: build failure (BTFIDS) with CONFIG_NET && !CONFIG_INET

[Yonghong Song]

On 9/29/20 3:17 AM, Michal Kubecek wrote:
> Hello,
>
> our builds of s390x for zfcpdump fail since 5.9-rc1 with
>
>      BTFIDS  vmlinux
>    FAILED unresolved symbol tcp_timewait_sock
>    make[1]: *** [/home/abuild/rpmbuild/BUILD/kernel-zfcpdump-5.9.rc7/linux-5.9-rc7/Makefile:1176: vmlinux] Error 255
>
> I believe this is caused by commit fce557bcef11 ("bpf: Make btf_sock_ids
> global") and the problem is caused by a specific configuration which has
> CONFIG_NET enabled but CONFIG_INET disabled. IIUC there will be no user
> of struct tcp_timewait_sock but btf_ids will try to generate BTF info
> for it.

Thanks for reporting! Will send a patch to fix the issue soon.

> Michal