From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755371AbdKBM4m (ORCPT ); Thu, 2 Nov 2017 08:56:42 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:54214 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752341AbdKBM4l (ORCPT ); Thu, 2 Nov 2017 08:56:41 -0400 Date: Thu, 2 Nov 2017 13:56:38 +0100 (CET) From: Thomas Gleixner To: Andy Lutomirski cc: Andy Lutomirski , Linus Torvalds , Dave Hansen , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , moritz.lipp@iaik.tugraz.at, Daniel Gruss , michael.schwarz@iaik.tugraz.at, Kees Cook , Hugh Dickins , X86 ML Subject: Re: [PATCH 02/23] x86, kaiser: do not set _PAGE_USER for init_mm page tables In-Reply-To: Message-ID: References: <20171031223146.6B47C861@viggo.jf.intel.com> <20171031223150.AB41C68F@viggo.jf.intel.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2 Nov 2017, Andy Lutomirski wrote: > > On Nov 2, 2017, at 12:33 PM, Thomas Gleixner wrote: > > Fair enough. I enabled function tracing with emulate_vsyscall as the filter > > on a couple of machines and so far I have no hit at all. Though I found a > > VM with a real old user space (~2005) and that actually used it. > > > > So for the problem at hand, I'd suggest we disable the vsyscall stuff if > > CONFIG_KAISER=y and be done with it. > > I think that time() on not-so-old glibc uses it. Sigh. > Even more recent versions of Go use it. :( Groan. VDSO is there since 2007 and the first usable version of Go was released in 2012..... Thanks, tglx From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id D42336B0033 for ; Thu, 2 Nov 2017 08:56:42 -0400 (EDT) Received: by mail-wm0-f71.google.com with SMTP id y7so2833358wmd.18 for ; Thu, 02 Nov 2017 05:56:42 -0700 (PDT) Received: from Galois.linutronix.de (Galois.linutronix.de. [2a01:7a0:2:106d:700::1]) by mx.google.com with ESMTPS id o40si2638943wrf.300.2017.11.02.05.56.41 for (version=TLS1_2 cipher=AES128-SHA bits=128/128); Thu, 02 Nov 2017 05:56:41 -0700 (PDT) Date: Thu, 2 Nov 2017 13:56:38 +0100 (CET) From: Thomas Gleixner Subject: Re: [PATCH 02/23] x86, kaiser: do not set _PAGE_USER for init_mm page tables In-Reply-To: Message-ID: References: <20171031223146.6B47C861@viggo.jf.intel.com> <20171031223150.AB41C68F@viggo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Andy Lutomirski Cc: Andy Lutomirski , Linus Torvalds , Dave Hansen , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , moritz.lipp@iaik.tugraz.at, Daniel Gruss , michael.schwarz@iaik.tugraz.at, Kees Cook , Hugh Dickins , X86 ML On Thu, 2 Nov 2017, Andy Lutomirski wrote: > > On Nov 2, 2017, at 12:33 PM, Thomas Gleixner wrote: > > Fair enough. I enabled function tracing with emulate_vsyscall as the filter > > on a couple of machines and so far I have no hit at all. Though I found a > > VM with a real old user space (~2005) and that actually used it. > > > > So for the problem at hand, I'd suggest we disable the vsyscall stuff if > > CONFIG_KAISER=y and be done with it. > > I think that time() on not-so-old glibc uses it. Sigh. > Even more recent versions of Go use it. :( Groan. VDSO is there since 2007 and the first usable version of Go was released in 2012..... Thanks, tglx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org