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

From: Jiri Olsa <jolsa@redhat.com>
To: Yonghong Song <yhs@fb.com>
Cc: "Michal Suchánek" <msuchanek@suse.de>,
	linux-kernel@vger.kernel.org, "Martin KaFai Lau" <kafai@fb.com>,
	"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: Mon, 26 Apr 2021 18:03:19 +0200	[thread overview]
Message-ID: <YIbkR6z6mxdNSzGO@krava> (raw)
In-Reply-To: <49f84147-bf32-dc59-48e0-f89241cf6264@fb.com>

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)

> > > > > > > 
> > > > > > > Looks like you have DYNAMIC_FTRACE config option enabled already.
> > > > > > > Could you try a later version of pahole?
> > > > > > 
> > > > > > Is this requireent new?
> > > > > > 
> > > > > > I have pahole 1.20, and master does build without problems.
> > > > > > 
> > > > > > If newer version is needed can a check be added?
> > > > > 
> > > > > With dwarves 1.21 some architectures are fixed and some report other
> > > > > missing symbol. Definitely an improvenent.
> > > > > 
> > > > > I see some new type support was added so it makes sense if that type is
> > > > > used the new dwarves are needed.
> > > > 
> > > > Ok, here is the current failure with dwarves 1.21 on 5.12:
> > > > 
> > > > [ 2548s]   LD      vmlinux
> > > > [ 2557s]   BTFIDS  vmlinux
> > > > [ 2557s] FAILED unresolved symbol vfs_truncate
> > > > [ 2558s] make[1]: ***
> > > > [/home/abuild/rpmbuild/BUILD/kernel-kvmsmall-5.12.0/linux-5.12/Makefile:1213:
> > > > vmlinux] Error 255
> 
> This is PPC64, from attached config:
>   CONFIG_PPC64=y
> I don't have environment to cross-compile for PPC64.
> Jiri, could you take a look? Thanks!

looks like vfs_truncate did not get into BTF data,
I'll try to reproduce

jirka