From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 458F46B0253 for ; Fri, 1 Jul 2016 10:37:38 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id e189so239443408pfa.2 for ; Fri, 01 Jul 2016 07:37:38 -0700 (PDT) Received: from out03.mta.xmission.com (out03.mta.xmission.com. [166.70.13.233]) by mx.google.com with ESMTPS id 68si4330382pff.189.2016.07.01.07.37.37 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Jul 2016 07:37:37 -0700 (PDT) From: ebiederm@xmission.com (Eric W. Biederman) References: <20160701001209.7DA24D1C@viggo.jf.intel.com> <20160701001218.3D316260@viggo.jf.intel.com> <5775F418.2000803@sr71.net> Date: Fri, 01 Jul 2016 09:25:10 -0500 In-Reply-To: (Linus Torvalds's message of "Thu, 30 Jun 2016 22:43:09 -0700") Message-ID: <874m89cu61.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [PATCH 6/6] x86: Fix stray A/D bit setting into non-present PTEs Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Dave Hansen , Linux Kernel Mailing List , the arch/x86 maintainers , linux-mm , Andrew Morton , Borislav Petkov , Andi Kleen , Michal Hocko , Dave Hansen Linus Torvalds writes: > On Thu, Jun 30, 2016 at 9:39 PM, Dave Hansen wrote: >> >> I think what you suggest will work if we don't consider A/D in >> pte_none(). I think there are a bunch of code path where assume that >> !pte_present() && !pte_none() means swap. > > Yeah, we would need to change pte_none() to mask off D/A, but I think > that might be the only real change needed (other than making sure that > we don't use the bits in the swap entries, I didn't look at that part > at all) It looks like __pte_to_swp_entry also needs to be changed to mask out those bits when the swap code reads pte entries. For all of the same reasons as pte_none. Eric -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752371AbcGAPb6 (ORCPT ); Fri, 1 Jul 2016 11:31:58 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:37546 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752134AbcGAPb4 (ORCPT ); Fri, 1 Jul 2016 11:31:56 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Linus Torvalds Cc: Dave Hansen , Linux Kernel Mailing List , "the arch\/x86 maintainers" , linux-mm , Andrew Morton , Borislav Petkov , Andi Kleen , Michal Hocko , Dave Hansen References: <20160701001209.7DA24D1C@viggo.jf.intel.com> <20160701001218.3D316260@viggo.jf.intel.com> <5775F418.2000803@sr71.net> Date: Fri, 01 Jul 2016 09:25:10 -0500 In-Reply-To: (Linus Torvalds's message of "Thu, 30 Jun 2016 22:43:09 -0700") Message-ID: <874m89cu61.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1bIzZV-0003MG-MZ;;;mid=<874m89cu61.fsf@x220.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=67.3.204.119;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19ODGWV2O+sqOFwxW1RqB783xKLzql+i8c= X-SA-Exim-Connect-IP: 67.3.204.119 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.7 XMSubLong Long Subject * 0.0 TVD_RCVD_IP Message was received from an IP address * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4994] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;Linus Torvalds X-Spam-Relay-Country: X-Spam-Timing: total 562 ms - load_scoreonly_sql: 0.08 (0.0%), signal_user_changed: 4.4 (0.8%), b_tie_ro: 3.1 (0.5%), parse: 1.32 (0.2%), extract_message_metadata: 29 (5.2%), get_uri_detail_list: 1.55 (0.3%), tests_pri_-1000: 12 (2.1%), tests_pri_-950: 2.4 (0.4%), tests_pri_-900: 1.99 (0.4%), tests_pri_-400: 31 (5.5%), check_bayes: 29 (5.1%), b_tokenize: 9 (1.7%), b_tok_get_all: 7 (1.3%), b_comp_prob: 3.6 (0.6%), b_tok_touch_all: 4.4 (0.8%), b_finish: 0.92 (0.2%), tests_pri_0: 466 (82.9%), check_dkim_signature: 0.99 (0.2%), check_dkim_adsp: 90 (16.1%), tests_pri_500: 7 (1.3%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH 6/6] x86: Fix stray A/D bit setting into non-present PTEs X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds writes: > On Thu, Jun 30, 2016 at 9:39 PM, Dave Hansen wrote: >> >> I think what you suggest will work if we don't consider A/D in >> pte_none(). I think there are a bunch of code path where assume that >> !pte_present() && !pte_none() means swap. > > Yeah, we would need to change pte_none() to mask off D/A, but I think > that might be the only real change needed (other than making sure that > we don't use the bits in the swap entries, I didn't look at that part > at all) It looks like __pte_to_swp_entry also needs to be changed to mask out those bits when the swap code reads pte entries. For all of the same reasons as pte_none. Eric