Re: linux-next failing build due to missing cubictcp_state symbol

From: Martin KaFai Lau <kafai@fb.com>
To: "Michal Suchánek" <msuchanek@suse.de>
Cc: Jiri Slaby <jirislaby@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
	Yonghong Song <yhs@fb.com>, <linux-kernel@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	David Ahern <dsahern@kernel.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Song Liu <songliubraving@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>, <netdev@vger.kernel.org>,
	<bpf@vger.kernel.org>, Jiri Olsa <jolsa@kernel.org>,
	Jesper Dangaard Brouer <brouer@redhat.com>
Subject: Re: linux-next failing build due to missing cubictcp_state symbol
Date: Wed, 5 May 2021 22:20:26 -0700	[thread overview]
Message-ID: <20210506052026.z5zwxnr453bqlsju@kafai-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <5a225970-32a2-1617-b264-bc40a2179618@kernel.org>

On Thu, May 06, 2021 at 06:31:57AM +0200, Jiri Slaby wrote:
> On 05. 05. 21, 15:56, Michal Suchánek wrote:
> > On Mon, Apr 26, 2021 at 09:16:36PM +0200, Jiri Olsa wrote:
> > > On Mon, Apr 26, 2021 at 06:03:19PM +0200, Jiri Olsa wrote:
> > > > On Mon, Apr 26, 2021 at 08:41:49AM -0700, Yonghong Song wrote:
> > > > > 
> > > > > 
> > > > > On 4/26/21 5:14 AM, Michal Suchánek wrote:
> > > > > > On Mon, Apr 26, 2021 at 02:12:20PM +0200, Michal Suchánek wrote:
> > > > > > > On Mon, Apr 26, 2021 at 01:32:15PM +0200, Michal Suchánek wrote:
> > > > > > > > On Sun, Apr 25, 2021 at 01:15:45PM +0200, Michal Suchánek wrote:
> > > > > > > > > On Fri, Apr 23, 2021 at 07:55:28PM +0200, Michal Suchánek wrote:
> > > > > > > > > > On Fri, Apr 23, 2021 at 07:41:29AM -0700, Yonghong Song wrote:
> > > > > > > > > > > 
> > > > > > > > > > > 
> > > > > > > > > > > On 4/23/21 6:05 AM, Michal Suchánek wrote:
> > > > > > > > > > > > Hello,
> > > > > > > > > > > > 
> > > > > > > > > > > > I see this build error in linux-next (config attached).
> > > > > > > > > > > > 
> > > > > > > > > > > > [ 4939s]   LD      vmlinux
> > > > > > > > > > > > [ 4959s]   BTFIDS  vmlinux
> > > > > > > > > > > > [ 4959s] FAILED unresolved symbol cubictcp_state
> > > > > > > > > > > > [ 4960s] make[1]: ***
> > > > > > > > > > > > [/home/abuild/rpmbuild/BUILD/kernel-vanilla-5.12~rc8.next.20210422/linux-5.12-rc8-next-20210422/Makefile:1277:
> > > > > > > > > > > > vmlinux] Error 255
> > > > > > > > > > > > [ 4960s] make: *** [../Makefile:222: __sub-make] Error 2
> > > > 
> > > > this one was reported by Jesper and was fixed by upgrading pahole
> > > > that contains the new function generation fixes (v1.19)
> > 
> > It needs pahole 1.21 here, 1.19 was not sufficient. Even then it
> > regressed again after 5.12 on arm64:
> 
> Could you try against devel:tools? I've removed the ftrace filter from
> dwarves there (sr#890247 to factory).
> 
> >    LD      vmlinux
> > ld: warning: -z relro ignored
> >    BTFIDS  vmlinux
> > FAILED unresolved symbol cubictcp_state
> > make[1]: *** [/home/abuild/rpmbuild/BUILD/kernel-vanilla-5.12.0.13670.g5e321ded302d/linux-5.12-13670-g5e321ded302d/Makefile:1196: vmlinux] Error 255
> > make: *** [../Makefile:215: __sub-make] Error 2
> > 
> > Any idea what might be wrong with arm64?
Can you also try this pahole patch which removes the ftrace filter:
https://lore.kernel.org/dwarves/20210506015824.2335125-1-kafai@fb.com/

I have just cross compiled with aarch64-linux-gcc together with the
above pahole patch.