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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 935AFC433DB for ; Sat, 30 Jan 2021 20:50:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C31364E17 for ; Sat, 30 Jan 2021 20:50:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232282AbhA3Utq (ORCPT ); Sat, 30 Jan 2021 15:49:46 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:22592 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232290AbhA3Utp (ORCPT ); Sat, 30 Jan 2021 15:49:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612039698; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VRe6hB7+FjbxOUrs96X+yC7oIpthfG0uqkuDXn9iS2w=; b=PQfyQ7BEwOSRGAD/NRT3RuSp7amzCvYb9hWkpEBDZjZdlVtFAT7196FcmrEPUBpfzBrKdF U78WFp28uC4QvVe2tw+mecKjLNc/qO4gkGYFhoufCrGyhaZzAyiiPlbA+zq7aR0we1KqWC uT8/MKA1hUX5q8fAMt1VYnZLvgoGfuY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-115-Fyto3C7yO3OAQbFcC8GL4w-1; Sat, 30 Jan 2021 15:48:14 -0500 X-MC-Unique: Fyto3C7yO3OAQbFcC8GL4w-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 53B3D107ACE3; Sat, 30 Jan 2021 20:48:13 +0000 (UTC) Received: from krava (unknown [10.40.192.30]) by smtp.corp.redhat.com (Postfix) with SMTP id 930F05C1BD; Sat, 30 Jan 2021 20:48:11 +0000 (UTC) Date: Sat, 30 Jan 2021 21:48:10 +0100 From: Jiri Olsa To: Alexei Starovoitov Cc: Paul Moore , Jiri Olsa , Arnaldo Carvalho de Melo , Andrii Nakryiko , bpf , Ondrej Mosnacek Subject: Re: selftest/bpf/test_verifier_log fails on v5.11-rc5 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Jan 29, 2021 at 07:13:21PM -0800, Alexei Starovoitov wrote: > On Fri, Jan 29, 2021 at 2:15 PM Paul Moore wrote: > > > > On Mon, Jan 25, 2021 at 5:42 PM Alexei Starovoitov > > wrote: > > > On Mon, Jan 25, 2021 at 12:54 PM Paul Moore wrote: > > > > > > > > Hello all, > > > > > > > > My apologies if this has already been reported, but I didn't see > > > > anything obvious with a quick search through the archives. I have a > > > > test program that behaves very similar to the existing > > > > selftest/bpf/test_verifier_log test that has started failing this week > > > > with v5.11-rc5; it ran without problem last week on v5.11-rc4. Is > > > > this a known problem with a fix already, or is this something new? > > > > > > > > % uname -r > > > > 5.11.0-0.rc5.134.fc34.x86_64 > > > > % pwd > > > > /.../linux/tools/testing/selftests/bpf > > > > % git log --oneline | head -n 1 > > > > 6ee1d745b7c9 Linux 5.11-rc5 > > > > % make test_verifier_log > > > > ... > > > > BINARY test_verifier_log > > > > % ./test_verifier_log > > > > Test log_level 0... > > > > Test log_size < 128... > > > > Test log_buff = NULL... > > > > Test oversized buffer... > > > > ERROR: Program load returned: ret:-1/errno:22, expected ret:-1/errno:13 > > > > > > Thanks for reporting. > > > bpf and bpf-next don't have this issue. Not sure what changed. > > > > I haven't had a chance to look into this any further, but Ondrej > > Mosnacek (CC'd) found the following today: > > > > "So I was trying to debug this further and I think I've identified what > > triggers the problem. It seems that the BTF debuginfo generation > > became broken with CONFIG_DEBUG_INFO_DWARF4=n somewhere between -rc4 > > and -rc5. It also seems to depend on a recent (Fedora Rawhide) version > > of some component of the build system (GCC, probably), because the > > problem disappeared when I tried to build the "bad" kernel in F33 > > buildroot instead of Rawhide." > > I see. There were fixes for dwarf and btf, but I lost the track. > I believe it was a combination of gcc bug that was worked around in pahole. > Arnaldo, Jiri, Andrii, > what is the status? Did all fixes land in pahole? I checked on rawhide and besides many pahole warnings, the resulted BTF data have many duplications in core structs BTFIDS vmlinux WARN: multiple IDs found for 'task_struct': 132, 1247 - using 132 WARN: multiple IDs found for 'file': 440, 1349 - using 440 WARN: multiple IDs found for 'inode': 698, 1645 - using 698 WARN: multiple IDs found for 'path': 729, 1672 - using 729 WARN: multiple IDs found for 'task_struct': 132, 2984 - using 132 WARN: multiple IDs found for 'task_struct': 132, 3043 - using 132 WARN: multiple IDs found for 'file': 440, 3085 - using 440 WARN: multiple IDs found for 'seq_file': 1469, 3125 - using 1469 WARN: multiple IDs found for 'inode': 698, 3336 - using 698 WARN: multiple IDs found for 'path': 729, 3366 - using 729 WARN: multiple IDs found for 'task_struct': 132, 5337 - using 132 WARN: multiple IDs found for 'inode': 698, 5360 - using 698 WARN: multiple IDs found for 'path': 729, 5388 - using 729 WARN: multiple IDs found for 'file': 440, 5412 - using 440 WARN: multiple IDs found for 'seq_file': 1469, 5639 - using 1469 WARN: multiple IDs found for 'task_struct': 132, 6243 - using 132 ... # gcc --version gcc (GCC) 11.0.0 20210123 (Red Hat 11.0.0-0) I'm guessing there are some DWARF changes that screwed BTF generation.. I'll check it's not covered by the fix I posted recently, but I think Arnaldo is now fixing some related stuff.. Arnaldo, maybe you are seeing same errors? I uploaded the build log from linking part to: http://people.redhat.com/~jolsa/build.out.gz jirka