From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5035BC433E0 for ; Wed, 30 Dec 2020 15:30:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A3DA21D94 for ; Wed, 30 Dec 2020 15:30:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbgL3Pag (ORCPT ); Wed, 30 Dec 2020 10:30:36 -0500 Received: from foss.arm.com ([217.140.110.172]:40584 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726197AbgL3Pag (ORCPT ); Wed, 30 Dec 2020 10:30:36 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2DBC8101E; Wed, 30 Dec 2020 07:29:50 -0800 (PST) Received: from e107158-lin (unknown [10.1.194.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E8F323F719; Wed, 30 Dec 2020 07:29:48 -0800 (PST) Date: Wed, 30 Dec 2020 15:29:46 +0000 From: Qais Yousef To: Jiri Olsa Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Jiri Olsa , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo Subject: Re: BTFIDS: FAILED unresolved symbol udp6_sock Message-ID: <20201230152946.gththmiujgj7qkj4@e107158-lin> References: <20201229151352.6hzmjvu3qh6p2qgg@e107158-lin> <20201229173401.GH450923@krava> <20201229232835.cbyfmja3bu3lx7we@e107158-lin> <20201230090333.GA577428@krava> <20201230132759.GB577428@krava> <20201230132852.GC577428@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201230132852.GC577428@krava> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/30/20 14:28, Jiri Olsa wrote: > On Wed, Dec 30, 2020 at 02:28:02PM +0100, Jiri Olsa wrote: > > On Wed, Dec 30, 2020 at 10:03:37AM +0100, Jiri Olsa wrote: > > > On Tue, Dec 29, 2020 at 11:28:35PM +0000, Qais Yousef wrote: > > > > Hi Jiri > > > > > > > > On 12/29/20 18:34, Jiri Olsa wrote: > > > > > On Tue, Dec 29, 2020 at 03:13:52PM +0000, Qais Yousef wrote: > > > > > > Hi > > > > > > > > > > > > When I enable CONFIG_DEBUG_INFO_BTF I get the following error in the BTFIDS > > > > > > stage > > > > > > > > > > > > FAILED unresolved symbol udp6_sock > > > > > > > > > > > > I cross compile for arm64. My .config is attached. > > > > > > > > > > > > I managed to reproduce the problem on v5.9 and v5.10. Plus 5.11-rc1. > > > > > > > > > > > > Have you seen this before? I couldn't find a specific report about this > > > > > > problem. > > > > > > > > > > > > Let me know if you need more info. > > > > > > > > > > hi, > > > > > this looks like symptom of the gcc DWARF bug we were > > > > > dealing with recently: > > > > > > > > > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97060 > > > > > https://lore.kernel.org/lkml/CAE1WUT75gu9G62Q9uAALGN6vLX=o7vZ9uhqtVWnbUV81DgmFPw@mail.gmail.com/#r > > > > > > > > > > what pahole/gcc version are you using? > > > > > > > > I'm on gcc 9.3.0 > > > > > > > > aarch64-linux-gnu-gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0 > > > > > > > > I was on pahole v1.17. I moved to v1.19 but I still see the same problem. > > > > > > I can reproduce with your .config, but make 'defconfig' works, > > > so I guess it's some config option issue, I'll check later today My .config was a defconfig + CONFIG_DEBUG_INFO_BTF + convert all modules to built-in. > > > > so your .config has > > CONFIG_CRYPTO_DEV_BCM_SPU=y Ah, how random. I removed this config and indeed it does work then, thanks! > > > > and that defines 'struct device_private' which > > clashes with the same struct defined in drivers/base/base.h > > > > so several networking structs will be doubled, like net_device: > > > > $ bpftool btf dump file ../vmlinux.config | grep net_device\' | grep STRUCT > > [2731] STRUCT 'net_device' size=2240 vlen=133 > > [113981] STRUCT 'net_device' size=2240 vlen=133 > > > > each is using different 'struct device_private' when it's unwinded > > > > and that will confuse BTFIDS logic, becase we have multiple structs > > with the same name, and we can't be sure which one to pick We can't tell which object/subsystem the struct come from? Or maybe we can introduce some annotation to help BTFIDS to pick the right one? > > > > perhaps we should check on this in pahole and warn earlier with > > better error message.. I'll check, but I'm not sure if pahole can > > survive another hastab ;-) > > > > Andrii, any ideas on this? ;-) > > > > easy fix is the patch below that renames the bcm's structs, > > it makes the kernel to compile.. but of course the new name > > is probably wrong and we should push this through that code > > authors > > also another quick fix is to switch it to module This works too. Thanks for your speedy response. Cheers -- Qais Yousef