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 CA3F6C433F5 for ; Thu, 17 Mar 2022 18:53:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237715AbiCQSyy (ORCPT ); Thu, 17 Mar 2022 14:54:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237750AbiCQSyq (ORCPT ); Thu, 17 Mar 2022 14:54:46 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF4241AD80 for ; Thu, 17 Mar 2022 11:53:21 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id o68-20020a17090a0a4a00b001c686a48263so1500140pjo.1 for ; Thu, 17 Mar 2022 11:53:21 -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=/NvfzwKXqOSJRruZzUWzCAPVPVy0wwITBus+R6UuGEE=; b=SFD8FzxQIXg9+hlH2Vkb1h3WUfBMuuS4W5CQ8oWADKUTQIWpB4dRFqdc4O5Wp5MjHR L0cc09yCNgySL0Erao+PzqYSsvtPV391iRt+TGZDuBkKHZVu5NTZZV8YnadPlkvDwi0x +pZYJ9KKEL89juosYwlv+5niKRFb2RIpDz9ZI= 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=/NvfzwKXqOSJRruZzUWzCAPVPVy0wwITBus+R6UuGEE=; b=RGw+dRFku/0IDFGorsa2NJd5A6O1kkw5tDoWB8pYFisJsQ7DPOs9QfDGYglUJejTxh sDBhSgiuWzzMIKkshEjcBFxHH/XjfOqEIya5wFOsrjVPgMAUx7vi9L/3QVZt072EquSX y/+JuskMnEIZpyGvfYfKZg4BCr/9lDHvL9qyZ01kGMSFmA8zVQ57kJz5idJzNTuCLHmE +uoyK7qA90vKOWwh3ZplPXpBqqrJZidXBmVbGKMoaJpwSTgJoU9GBJwurpQioeLq9k6p 7lpbtmxDUgV+UkP9pZD9e3QENc02rAhZCPqe6ZI5Kf2evLmET7Hbns8/azfGk4TIIpg+ zIYg== X-Gm-Message-State: AOAM530Ec8t9GrLF6QfdjtjQOgj28bOASogyF6BYQn7L3TA+ni6htY4Z 0Rgtycchky86LMaSuZ4Infk2y8h+QocSBw== X-Google-Smtp-Source: ABdhPJxf8zUz4uL69RiHyWHnXrMc949FYbCcqIxC/VkLIVftNL2WTrnWJwvtr47QpDWnhkWwQelguA== X-Received: by 2002:a17:902:ce02:b0:153:bd65:5c0e with SMTP id k2-20020a170902ce0200b00153bd655c0emr6088248plg.160.1647543200564; Thu, 17 Mar 2022 11:53:20 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id u10-20020a056a00124a00b004f783abfa0esm7530041pfi.28.2022.03.17.11.53.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Mar 2022 11:53:20 -0700 (PDT) Date: Thu, 17 Mar 2022 11:53:19 -0700 From: Kees Cook To: James Jones Cc: Arnd Bergmann , Borislav Petkov , the arch/x86 maintainers , Linux Kernel Mailing List Subject: Re: [PATCH] x86: Remove a.out support Message-ID: <202203171152.F35EB19767@keescook> References: <4c449fab-8135-5057-7d2c-7b948ce130cc@theinnocuous.com> <0b31b1d3-852d-6cab-82ae-5eecaec05679@theinnocuous.com> <202203151150.1CDB1D8DA@keescook> <202203161523.857B469@keescook> <59fb3d14-423a-d39b-04cb-1e60ee67d3f1@theinnocuous.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <59fb3d14-423a-d39b-04cb-1e60ee67d3f1@theinnocuous.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 17, 2022 at 02:04:46AM +0000, James Jones wrote: > On 3/16/22 3:30 PM, Kees Cook wrote: > > On Wed, Mar 16, 2022 at 01:38:31PM +0100, Arnd Bergmann wrote: > >> is in the end, but it's likely easier than a standalone a.out loader > >> in user space, or a conversion to ELF format. > > > > Yeah, the exec format is really simple. The only tricky bit was preparing > > the stack and making sure everything landed in the right place for text > > and data. James, can you try this? aln and mac run for me, but I'm not > > actually exercising them beyond dumping argument lists, etc: > > > > https://github.com/kees/kernel-tools/tree/trunk/a.out > > Yes, works perfectly, thank you. I like the idea of using this much Hurray! > better than getting emailed every time someone wants to delete the a.out > code again. Consider my use case withdrawn. I've already pushed an > update to my jaguar-sdk project to use this tool instead. Nice; I see there are other binaries besides aln and mac that are working with this too? *whew* I'm glad it was relatively straight forward. :) -- Kees Cook