From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755175Ab1HJWWc (ORCPT ); Wed, 10 Aug 2011 18:22:32 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46400 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751616Ab1HJWWb (ORCPT ); Wed, 10 Aug 2011 18:22:31 -0400 References: <8449fb3abf89851fd6b2260972666a6f82542284.1312988155.git.luto@mit.edu> <4E42BDFF.5060507@zytor.com> User-Agent: K-9 Mail for Android In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH 3/3] x86-64: Rework vsyscall emulation and add vsyscall= parameter From: "H. Peter Anvin" Date: Wed, 10 Aug 2011 17:20:58 -0500 To: Andrew Lutomirski CC: x86@kernel.org, Andi Kleen , linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, lueckintel@yahoo.com, kimwooyoung@gmail.com, Ingo Molnar , Borislav Petkov Message-ID: <4b8d6929-6163-4e25-933c-c875a1857f3a@email.android.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Lutomirski wrote: >On Wed, Aug 10, 2011 at 5:14 PM, H. Peter Anvin wrote: >> Andrew Lutomirski wrote: >> >>>On Wed, Aug 10, 2011 at 1:21 PM, H. Peter Anvin >wrote: >>>> On 08/10/2011 10:15 AM, Andy Lutomirski wrote: >>>>> There are three choices: >>>>> >>>>> vsyscall=native: Vsyscalls are native code that issues the >>>>> corresponding syscalls. >>>>> >>>>> vsyscall=emulate (default): Vsyscalls are emulated by instruction >>>>> fault traps, tested in the bad_area path.  The actual contents of >>>>> the vsyscall page is the same as the vsyscall=native case except >>>>> that it's marked NX.  This way programs that make assumptions >about >>>>> what the code in the page does will not be confused when they read >>>>> that code. >>>>> >>>>> vsyscall=none: Trying to execute a vsyscall will segfault. >>>>> >>>>> Signed-off-by: Andy Lutomirski >>>> >>>> Hi Andy, >>>> >>>> This patch doesn't apply.  What is your baseline for this patch? >>> >>>My baseline was a commit that probably only lives in my tree, but the >>>patches should apply cleanly on top of >>>c149a665ac488e0dac22a42287f45ad1bda06ff1, which is the current >>>tip/x86/vdso. >>> >>>--Andy >> >> Please rebase your patch on the current -linus since it appears to >have changed since x86/vdso was merged. >> > >Can you double-check? I think it's the other way around: x86/vdso has >fixes that should be pushed to Linus. > >$ git log tip/x86/vdso ^origin/master --oneline >c149a66 x86-64: Add vsyscall:emulate_vsyscall trace event >318f5a2 x86-64: Add user_64bit_mode paravirt op >5d5791a x86-64, xen: Enable the vvar mapping >f670bb7 x86-64: Work around gold bug 13023 >9c40818 x86-64: Move the "user" vsyscall segment out of the data >segment. >1bdfac1 x86-64: Pad vDSO to a page boundary >17b0436 Merge commit 'v3.0' into x86/vdso > >--Andy You're right, although coupling it makes the testing harder. -- Sent from my mobile phone. Please excuse my brevity and lack of formatting.