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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D0F65C433DB for ; Wed, 10 Feb 2021 16:10:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A63D464E45 for ; Wed, 10 Feb 2021 16:10:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232068AbhBJQKo (ORCPT ); Wed, 10 Feb 2021 11:10:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:54784 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230489AbhBJQKk (ORCPT ); Wed, 10 Feb 2021 11:10:40 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 62DDB64E79 for ; Wed, 10 Feb 2021 16:09:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612973399; bh=qkJZIAItpLuMeUw4ojssOOi4gB0ScOne5y6B9A84OKY=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=pihK3FOVKFZVSqkBgE3x1SCat94rZavRbHZ74WoGc5Fh36QpamObEZ6XcrNouOBQb k8xF7T91ZfDPsVQ8lyjIx0sde5ckGM4iuhBGpd0jLy8Lhx7au0ye3m2wPDq1NWhdOh mPCthEtxaik45A1TPK+Q/iL2eEqU9c+ChQQWzjHyEDJHpUAmJVBpik7g+imSPVRLkR i3hNdJCJIQVOBzJWUUhljMHGREq+MftnxME9s69m03aA2P0OLfYiATOwq0KP+Eiz5o fYuqrB5739feZT2N6S9alymrDNiITXGAj+Zb9ubHdmQ+x05WeDR44NsZnWylPqvr8v fAEimAm5NZM/Q== Received: by mail-ej1-f42.google.com with SMTP id y9so5115032ejp.10 for ; Wed, 10 Feb 2021 08:09:59 -0800 (PST) X-Gm-Message-State: AOAM532MR10sQauHhu67LqR7bxUzlfBP5ZrX5UTF7rVfXwzsC/IbywKz 9Z5s5WOPZixTtpTCVOJkRQ8eTdXjWlYOr8+v10lvLw== X-Google-Smtp-Source: ABdhPJyTgQ6foi+FhtPesOcGnNrjqZCS9eHuiG/0PuajOqAwU/l/X1qj8nAmwHBM5mFE3NMtKBVKxamemJYxyeMpjn0= X-Received: by 2002:a17:906:b09a:: with SMTP id x26mr3691344ejy.199.1612973397900; Wed, 10 Feb 2021 08:09:57 -0800 (PST) MIME-Version: 1.0 References: <8969c688ee663e99901cf4b0383bc6662ce79707.1612924255.git.luto@kernel.org> <20210210132928.GB14650@zn.tnic> In-Reply-To: <20210210132928.GB14650@zn.tnic> From: Andy Lutomirski Date: Wed, 10 Feb 2021 08:09:45 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 08/14] x86/fault: Skip erratum #93 workaround on new CPUs To: Borislav Petkov Cc: Andy Lutomirski , X86 ML , LKML , Dave Hansen , Alexei Starovoitov , Daniel Borkmann , Yonghong Song , Masami Hiramatsu Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 10, 2021 at 5:29 AM Borislav Petkov wrote: > > On Tue, Feb 09, 2021 at 10:06:02PM -0800, Andy Lutomirski wrote: > > On Tue, Feb 9, 2021 at 6:33 PM Andy Lutomirski wrote: > > > > > > Erratum #93 applies to the first generation of AMD K8 CPUs. Skip the > > > workaround on newer CPUs. > > > > Whoops, this breaks the !CPU_SUP_AMD build. It needs a fixup like this: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/commit/?h=x86/fault&id=06772a3b6918bf6d6d0778946149b7d56ae30d80 > > > > Boris, do you want a v3? > > Do we even want to apply patch 8 at all? This has always ran on K8 NPT > CPUs too and those are pretty much obsolete by now so I'm thinking, > leave sleeping dogs lie...? I think we do want this patch. Without it, there's a fairly sizeable range of bogus RIP values that will result in applying the fixup instead of properly oopsing, even on new CPUs.