From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752441AbaEAWSj (ORCPT ); Thu, 1 May 2014 18:18:39 -0400 Received: from mga03.intel.com ([143.182.124.21]:46293 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751762AbaEAWSi (ORCPT ); Thu, 1 May 2014 18:18:38 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,967,1389772800"; d="scan'208";a="426555392" Date: Thu, 1 May 2014 15:18:36 -0700 From: Andi Kleen To: "H. Peter Anvin" Cc: Andi Kleen , Andy Lutomirski , X86 ML , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 4/7] x86: Add support for rd/wr fs/gs base Message-ID: <20140501221836.GI19657@tassilo.jf.intel.com> References: <1398723161-21968-1-git-send-email-andi@firstfloor.org> <1398723161-21968-5-git-send-email-andi@firstfloor.org> <535FED4D.5000703@amacapital.net> <20140429233950.GE2382@two.firstfloor.org> <53608180.5070800@zytor.com> <20140501211554.GH2382@two.firstfloor.org> <5362C37E.2090603@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5362C37E.2090603@zytor.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I haven't looked through the flows (I'm at LCE so I have limited screen > bandwidth) to see how that would be handled in this case, but in the > general paranoid case it comes down to the fact that in this particular > subcase we don't necessarily know exactly how many SWAPGS are between us > and userspace after we IRET. There is none as far as I know. Certainly wasn't any when the code was originally written. -Andi -- ak@linux.intel.com -- Speaking for myself only