2020-09-29 10:19:07

by Michal Kubecek

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

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.

Michal

2020-09-30 05:00:04

by Yonghong Song

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

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
>