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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86687C433F5 for ; Tue, 4 Oct 2022 19:24:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229678AbiJDTYc (ORCPT ); Tue, 4 Oct 2022 15:24:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229671AbiJDTYb (ORCPT ); Tue, 4 Oct 2022 15:24:31 -0400 Received: from mail-pf1-x433.google.com (mail-pf1-x433.google.com [IPv6:2607:f8b0:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09605696F6 for ; Tue, 4 Oct 2022 12:24:30 -0700 (PDT) Received: by mail-pf1-x433.google.com with SMTP id u21so8322866pfc.13 for ; Tue, 04 Oct 2022 12:24:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date; bh=TPHGjn63G4Sj8mZqFRVnqMa0MXMfRBRw4erndCFr2yc=; b=N62in1FHINxzmpEMCxU1iYHaOAzaej9i3j46sXOtPXoNR+pnNbuAfgPGOWR0M9aNRx FEybgsaF2Wj0UOJ4KmCZJPR8YXthw0ow2bau2vicE2MOXSf7UQWfApIDbTrlrboQ5js5 ZfuVhu1x6EtUT6X3rjEQV1fJMnlg/mTn3ESLE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date; bh=TPHGjn63G4Sj8mZqFRVnqMa0MXMfRBRw4erndCFr2yc=; b=gx1uAi4TY87ZQTswKzF9UyGL0MmhWKIHjTfaKbi5BQ6s2ss/lCEZqwNg2YC2DMkuWu Vcv1kON9OwCVtZTNMR1yh04RfQW3p0ftRKHBlY5hj0aGPOXCBiwQ2TSartyWFDlpx06g cjehFzImqUrT1z+JpoPnuBzqfNQ5+f7TDpB1yuO20SmRSWgWu28n8yiY9qnMtAof33ev cfmZp68OrtZulX/e37b+oqBPmOMoTNxobgkk1DhjuUNnG7I4PR/poAQaxKieKBhA+P9y ctESBXm51xsGGr4INaZ7jkNgdgB/VVSZ2eIM5glE1DZR2VdR0+wZXVqXNEcElOIM4atw CiSw== X-Gm-Message-State: ACrzQf3/O4c+f63hdB8wcbf5w//0lMx47grAYsxJh7GTqn+zdDoy0jrI G6wACPvZDbxYfacREXoHxe68Eg== X-Google-Smtp-Source: AMsMyM4HxL0s5qvx/MF11QUaz7zgb8PObZXUvmqkMZ2tOrL2yDra9OycFNKkIhPW7kbGndOV83ZFTg== X-Received: by 2002:a63:da03:0:b0:439:dcdd:67f4 with SMTP id c3-20020a63da03000000b00439dcdd67f4mr24551120pgh.27.1664911469526; Tue, 04 Oct 2022 12:24:29 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id d1-20020a170903230100b00177efb56475sm9328173plh.85.2022.10.04.12.24.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Oct 2022 12:24:28 -0700 (PDT) Date: Tue, 4 Oct 2022 12:24:27 -0700 From: Kees Cook To: Mike Rapoport Cc: Rick Edgecombe , x86@kernel.org, "H . Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V . Shankar" , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, jamorris@linux.microsoft.com, dethoma@microsoft.com, Yu-cheng Yu Subject: Re: [OPTIONAL/RFC v2 37/39] x86/cet: Add PTRACE interface for CET Message-ID: <202210041224.E4C63B1@keescook> References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-38-rick.p.edgecombe@intel.com> <202210031658.EEC88324FD@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Tue, Oct 04, 2022 at 11:44:16AM +0300, Mike Rapoport wrote: > On Mon, Oct 03, 2022 at 04:59:43PM -0700, Kees Cook wrote: > > On Thu, Sep 29, 2022 at 03:29:34PM -0700, Rick Edgecombe wrote: > > > From: Yu-cheng Yu > > > > > > Some applications (like GDB and CRIU) would like to tweak CET state via > > > > Eee. Does GDB really need this? Can we make this whole thing > > CONFIG-depend on CRIU? > > GDB, at least its Intel fork uses this. I don't see how they can jump > between frames without an ability to modify shadow stack contents. > > Last I looked they used NT_X86_CET to update SSP and ptrace(POKEDATA) to > write to the shadow stack. Okay, thanks! I appreciate having specific examples. :) -- Kees Cook