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 94B2DC433F5 for ; Wed, 20 Apr 2022 02:42:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358974AbiDTCpb (ORCPT ); Tue, 19 Apr 2022 22:45:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348743AbiDTCp2 (ORCPT ); Tue, 19 Apr 2022 22:45:28 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F3DB37BE5 for ; Tue, 19 Apr 2022 19:42:44 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id n18so520915plg.5 for ; Tue, 19 Apr 2022 19:42:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Vfe+Bo823sceHSMTTMCrGjAFXbrqNJngyy3/uN1hL1I=; b=MUANZlDdci93YXmyvk7nXE97lb09WlyFylCgklEfOHlREsE5OkC7hfuVnPnuyPpKjC JzLygb+5F8nGWablsLdvHDn2ZTpGPyEeVR1Zxa38DsbCW+NLeNn1i3vKMvvZqoEcpDtT MvpgTGV40uu+7drFOoCFkbwuFa7nqFXT+o7TQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Vfe+Bo823sceHSMTTMCrGjAFXbrqNJngyy3/uN1hL1I=; b=fjWB8mj0yGOpvAD1RouCMr5Qf+C1SzQguFLgBn/6wVB8LQlo+g/249keTWGb5dPl7j bBxGX9Sxf96ariByr78tzHK4FZndrmZkKqKnel4lRUB9TFvCewRuPaEIUFacaAYvRZbm XFgvbFDTAaNfjbKW/InUWqa7wddpSFSzrM3O30bf+IPhAIAor0/31FISXvoFHMGLODjg nz5+nuaFdAumqSXds8yxAJ2u1Bmsk+xtdhjMjUlH6CW841RLYFfKIPTjm04/2Lp81iWh WGRWFODk5jujgLg5Og/ysKL6sHm/g62C7yFCJxymm8Z+jiML/BWLv6k7jpsA+70TMm6O Ixaw== X-Gm-Message-State: AOAM533CE4Y6bmDPiAvxrx9Rl4O24MUUTsOS0dBDCj+Zd8UOhYacbDjc aGu5HYKlIKwgrLn0AQEGx1xSrg== X-Google-Smtp-Source: ABdhPJwcbF3zvvNRv1yktmDfMhCKXAAAPtr8AO3e++qx5yZz54gLhHTMNEUZXAV+ruHi2jGCY5n6tQ== X-Received: by 2002:a17:902:7489:b0:158:8868:5030 with SMTP id h9-20020a170902748900b0015888685030mr19057499pll.132.1650422563800; Tue, 19 Apr 2022 19:42:43 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id p27-20020a056a000a1b00b004f3f63e3cf2sm19763951pfh.58.2022.04.19.19.42.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Apr 2022 19:42:43 -0700 (PDT) Date: Tue, 19 Apr 2022 19:42:42 -0700 From: Kees Cook To: joao@overdrivepizza.com Cc: linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, peterz@infradead.org, jpoimboe@redhat.com, andrew.cooper3@citrix.com, samitolvanen@google.com, mark.rutland@arm.com, hjl.tools@gmail.com, alyssa.milburn@linux.intel.com, ndesaulniers@google.com, gabriel.gomes@linux.intel.com, rick.p.edgecombe@intel.com Subject: Re: [RFC PATCH 00/11] Kernel FineIBT Support Message-ID: <202204191937.2720E7E@keescook> References: <20220420004241.2093-1-joao@overdrivepizza.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220420004241.2093-1-joao@overdrivepizza.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! On Tue, Apr 19, 2022 at 05:42:30PM -0700, joao@overdrivepizza.com wrote: > I'm considering detaching the prototype fixes from this series and reworking > them to submit actual fixes (patches 10 and 11). Any specific suggestions for > these specific patches? Maybe you want to take a look and help in co-authorship > as we did with the void*-in-x86-crypto patches in the past? I guess these are > useful for whatever CFI scheme is in place. Yeah, if 10 and 11 are general prototype-based fixes, let's get them in. I would expect regular CFI and kCFI to trip over those too. I'll comment on those patches directly. > Any other major concerns, ideas, or suggestions? :) I think it'd be good to get kCFI landed in Clang first (since it is effectively architecture agnostic), and then get FineIBT landed. But that doesn't mean we can't be working on the kernel side of things at the same time. And just thinking generally, for other architecture-specific stuff, I do wonder what an arm64 PAC-based CFI might look like. I prefer things be hard-coded as kCFI is doing, but it'd be nice to be able to directly measure performance and size overheads comparing the various methods. -- Kees Cook