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=-16.9 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_IN_DEF_DKIM_WL autolearn=ham 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 E6721C4741F for ; Mon, 28 Sep 2020 07:25:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB166221E8 for ; Mon, 28 Sep 2020 07:25:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="c9tNr+0S" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726566AbgI1HZP (ORCPT ); Mon, 28 Sep 2020 03:25:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726328AbgI1HZP (ORCPT ); Mon, 28 Sep 2020 03:25:15 -0400 Received: from mail-ot1-x341.google.com (mail-ot1-x341.google.com [IPv6:2607:f8b0:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35ADAC0613CE for ; Mon, 28 Sep 2020 00:25:15 -0700 (PDT) Received: by mail-ot1-x341.google.com with SMTP id 60so8765423otw.3 for ; Mon, 28 Sep 2020 00:25:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=jml2neKeP5LvDDGsfQfoMJWoSSFjKlccfEpIy6JbJzg=; b=c9tNr+0Sf8lZSRvtQbSe9kz8QQjv+dseeGRXmj2HyERSbc4Qpgay2plrHZ/88sgP/k YagyDPo9uMHOOUMb9j24ZOz0ygMCnywlnMKiPYfFKdXYHtTzKJqbfewERiW26eg+2IgB JAJSppUt8I0/oyaDaUAGv9AeJYfahhpXuSatV0jjMukn4Su7NvLG1e6I5OH00+zTrSbM RphdrkVsaEbAR30T0BCHX7e/ktEfr/Cg44FBtcNjnBw6S2qnbArhrEOfFnj3y/Af9/Y3 PITAb1TOl/4Uuhq0DB5SH1nyCWuLSYyktexiZfqhNXsSoXTRL1GUjNSGjWjC9fY/OVU/ EkLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=jml2neKeP5LvDDGsfQfoMJWoSSFjKlccfEpIy6JbJzg=; b=Ml6bF9QXfsK/5iwX+Qx67AJ0an2H1sGiqMAYJn802+XX9qVwxVLyzkQIrmja8DE++H H2a0ARrLVvfsToyoL9CG97Q52oA4dih4jgwd0HHCYyyseKwUovWjbwH+oB7jyYVq5DqO eXkrmKLb8w7LlTdERxcioJ3HaigBAB4Y3nH/wfsHrjAAQkls7mKW6/DR/HZjbhGxZQDg niFu07ymL8PEVRzhzBuwEVp8mzc/RwjTypV0wT/SgCRGelV/GRN/n8/DJE07fldpkTP8 isMSFYnjq1E7BrAWWLLouOJZYNftW4eUUKjqRDEdL0ppz9Sjbp/qT8Eeo7sOy73W1Vx2 NRwA== X-Gm-Message-State: AOAM5314ypm6e0vKn/Z8G/aotqSk4rD70EWDVnSoIlIGBfBKMLyBtxGl 5MM1aekxZyG1xt1f0xoi/7IbF5CDj0OoYe3tLV0wSg== X-Google-Smtp-Source: ABdhPJxOW6W4XCiLFCFv0Vpb67Sb416PTR6EILccVp+ZcRJczEvoAHSyG+Sc2DgGuRBVv24MDN/T1eZrnKTkq3I1hQg= X-Received: by 2002:a9d:66a:: with SMTP id 97mr94939otn.233.1601277914299; Mon, 28 Sep 2020 00:25:14 -0700 (PDT) MIME-Version: 1.0 References: <00000000000052569205afa67426@google.com> <20200927145737.GA4746@zn.tnic> In-Reply-To: From: Marco Elver Date: Mon, 28 Sep 2020 09:25:03 +0200 Message-ID: Subject: Re: general protection fault in perf_misc_flags To: Dmitry Vyukov Cc: Borislav Petkov , Alexander Potapenko , syzbot , Arnaldo Carvalho de Melo , Alexander Shishkin , "H. Peter Anvin" , Jiri Olsa , LKML , Mark Rutland , Ingo Molnar , Namhyung Kim , Peter Zijlstra , syzkaller-bugs , Thomas Gleixner , "the arch/x86 maintainers" , clang-built-linux Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 28 Sep 2020 at 07:18, Dmitry Vyukov wrote: > > On Sun, Sep 27, 2020 at 4:57 PM Borislav Petkov wrote: > > > > On Sat, Sep 19, 2020 at 01:32:14AM -0700, syzbot wrote: > > > Hello, > > > > > > syzbot found the following issue on: > > > > > > HEAD commit: 92ab97ad Merge tag 'sh-for-5.9-part2' of git://git.libc.or.. > > > git tree: upstream > > > console output: https://syzkaller.appspot.com/x/log.txt?x=1069669b900000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=cd992d74d6c7e62 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ce179bc99e64377c24bc > > > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > > > > All below is AFAICT: > > > > This compiler you're using is not some official release but some random > > commit before the v10 release: > > > > $ git show c2443155a0fb245c8f17f2c1c72b6ea391e86e81 > > Author: Hans Wennborg > > Date: Sat Nov 30 14:20:11 2019 +0100 > > > > Revert 651f07908a1 "[AArch64] Don't combine callee-save and local stack adjustment when optimizing for size" > > ... > > > > $ git describe c2443155a0fb245c8f17f2c1c72b6ea391e86e81 > > llvmorg-10-init-10900-gc2443155a0fb > > > > The v10 release is: > > > > $ git show llvmorg-10.0.0 > > tag llvmorg-10.0.0 > > Tagger: Hans Wennborg > > Date: Tue Mar 24 12:58:58 2020 +0100 > > > > Tag 10.0.0 > > > > and v10 has reached v10.0.1 in the meantime: > > > > $ git log --oneline c2443155a0fb245c8f17f2c1c72b6ea391e86e81~1..llvmorg-10.0.1 | wc -l > > 7051 > > > > so can you please update your compiler and see if you can still > > reproduce with 10.0.1 so that we don't waste time chasing a bug which > > has been likely already fixed in one of those >7K commits. > > +Alex, Marco, > > There is suspicion that these may be caused by use of unreleased clang. > Do we use the same clang as we use for the KMSAN instance? But this is > not KMSAN machine, so I am not sure who/when/why updated it last to > this revision. > I even see we have some clang 11 version: > https://github.com/google/syzkaller/blob/master/docs/syzbot.md#crash-does-not-reproduce Yeah, we should replace that one as well as it wasn't yet a release-candidate. > Is it possible to switch to some released version for both KMSAN and KASAN now? We should probably just switch to Clang 11-rc3 or so. Then we can use the same compiler for KMSAN and KCSAN at least. I can package up a newer Clang. Thanks, -- Marco