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 6EA10C4332F for ; Fri, 10 Nov 2023 00:08:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345510AbjKJAIj (ORCPT ); Thu, 9 Nov 2023 19:08:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235073AbjKJAIW (ORCPT ); Thu, 9 Nov 2023 19:08:22 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA38D9ECE for ; Thu, 9 Nov 2023 16:03:54 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D0424C433C8; Fri, 10 Nov 2023 00:03:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699574634; bh=h8AjMlgeweBber584pcT8cef3G9RzsF/azvY3XBYmWo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=crAAHkbywAX0uho+8nKwbw5mdekCYhR921Wmj8yzSvKYkEm1phZ6U4it4mnSS3bKD apZPL146J6/id+qoH6ak/vTHZmbcSTkB8sLUg9d0WkGDyKuhn3fl3UMuy3uQGWAnz5 QsguxjwcX6vMXhVCZ5wlF4NbHFkCD+nJEM3Vf9sigs1zwmwBJIic7auG3zYuOzYCZy X0ZbzCSYnKvnM+yvhJJjGgwXZuWBsi5RPFavgam6u90Ne+b5hp8RynfLs24I/vMKR1 sXfbgPpBkbTX6gsDSM7JFqdRhfHgnpbCRsbsSpkZAwUsX+gbj9P1dcB+hO1/wj8Mj6 O2XEVe1jyfRgg== Date: Thu, 9 Nov 2023 16:03:52 -0800 From: Josh Poimboeuf To: Ingo Molnar Cc: "H. Peter Anvin" , Kristen Carlson Accardi , Hou Wenlong , linux-kernel@vger.kernel.org, Lai Jiangshan , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT" , Anshuman Khandual , Mike Rapoport , Pasha Tatashin Subject: Re: [PATCH RFC 1/7] x86/head/64: Mark startup_gdt and startup_gdt_descr as __initdata Message-ID: <20231110000352.zr6z6yofumdbk4wd@treble> References: <20231017072311.GA46993@k08j02272.eu95sqa> <77B66FD0-ED28-4D3F-8D28-467AC4FCD00D@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 18, 2023 at 01:45:40PM +0200, Ingo Molnar wrote: > > * H. Peter Anvin wrote: > > > If the goal is better KASLR, then what we really should spend time on was > > Kristen Accardi's fgKASLR patches, which not only exponentially(!) > > increases the randomization entrophy but also *actually* avoids the "one > > leak and it's over" problem. > > Agreed. Going by this version of function-granularity KASLR from 3 years > ago: > > https://lwn.net/Articles/824307/ > https://lwn.net/ml/linux-kernel/20200623172327.5701-1-kristen@linux.intel.com/ > > The fgKASLR feature looks entirely viable to me. Back then I presumed it > would get iterated beyond v3, and then it fell off my radar. :-/ > > If Kristen or someone else would like to dust this off & submit a fresh > version it would be much appreciated! That actually got up to v10: https://lkml.kernel.org/lkml/20220209185752.1226407-1-alexandr.lobakin@intel.com Anyway, I'm also very interested in this. If nobody else is working on it then I could give it a try. BTW I've wondered if translation-unit granularity would be more preferable than function granularity due to improved i-cache locality and (possibly) easier livepatch compatibility. -- Josh