From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934690AbaLLU1V (ORCPT ); Fri, 12 Dec 2014 15:27:21 -0500 Received: from mail-pa0-f44.google.com ([209.85.220.44]:48393 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751254AbaLLU1T (ORCPT ); Fri, 12 Dec 2014 15:27:19 -0500 Message-ID: <548B4FA4.40700@amacapital.net> Date: Fri, 12 Dec 2014 12:27:16 -0800 From: Andy Lutomirski User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Dave Hansen , linux-kernel@vger.kernel.org CC: tglx@linutronix.de, x86@kernel.org Subject: Re: [RFC][PATCH 0/8] x86, mpx: Support 32-bit binaries on 64-bit kernels References: <20141212191213.579887D2@viggo.jf.intel.com> In-Reply-To: <20141212191213.579887D2@viggo.jf.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/12/2014 11:12 AM, Dave Hansen wrote: > This is 3.20 material. I'm hoping to get some comments early > in case folks have some issues with the way it's being done. > Would it make sense to disable MPX for 32-bit binaries on 64-bit kernels for 3.19? --Andy > -- > > The MPX hardware structures differ in layout in 32 and 64-bit > mode. A 32-bit binary running on a 64-bit kernel needs the > 32-bit structures, so we need code which switches between > the two modes. > > The first patch is just a documentation update. The next 5 > patches are really just prepwork. The meat is in the last 3. > > x86: make is_64bit_mm() widely available > x86: make __VIRTUAL_MASK safe to use on 32 bit > x86, mpx: we do not allocate the bounds directory > x86, mpx: remove redundant MPX_BNDCFG_ADDR_MASK > x86, mpx: Add temporary variable to reduce masking > x86, mpx: new directory entry to addr helper > x86, mpx: do 32-bit-only cmpxchg for 32-bit apps > x86, mpx: support 32bit binaries on 64bit kernel > > Documentation/x86/intel_mpx.txt | 12 +++- > arch/x86/include/asm/mmu_context.h | 13 +++++ > arch/x86/include/asm/mpx.h | 2 > arch/x86/include/asm/page_types.h | 8 +++ > arch/x86/kernel/uprobes.c | 10 --- > arch/x86/mm/mpx.c | 93 ++++++++++++++++++++++++++++++------- > 6 files changed, 107 insertions(+), 31 deletions(-) >