From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226PWrVmZllDUnhfzp7eDxTT2oCO5R36theqpggrx/7bzDX9OwZOi2ZbYF0PD1BqFVfF8sSq ARC-Seal: i=1; a=rsa-sha256; t=1516900256; cv=none; d=google.com; s=arc-20160816; b=rJwsD9GzcoqFK394+XZQBzv9jb3kW7cnFNjK6L1aF7GujYAaQCtE1/wJC0AYwfheGl 4idnPML5LH0UQPJkbPG+i3vX4t7iBTmSsH34y7pR8Fd0Bkygb5XCHzTrpqDQeu+CKo1k mcQTIq/+B10JNYeZPZhS7NUMeAiSDUE2L7F4h07vq8o9RH3AO6Sbe9Y0vW6OdgVMksQ4 6ZPWE3G4OHFJ9+9i5/QCMXDfI9YyFIh8Q0p56wvivCP57j+DrRlwJdzk6BmcHEGAJEXG 0g1bYH1pjvJnXU+8OfND0+1cBQT+m+X8258wX3D2CMFi/iH6vvY0i2cIoagy9gi83pdH wp+Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:organization:references :in-reply-to:message-id:subject:cc:to:from:date :arc-authentication-results; bh=7vxLcRMmIKJkPYiFdvTnDBSC0q2JGZq3tAKUeEyxfzM=; b=BikSIpUKGxQGQoNdII1Kg+53NPpsxwxIrktXaWF+XUWfDNPVeOZOE33eiZymKPt35/ BXyT13LhwoBADKqX1VAaaoMpn8e1ntfzF8jHiyRP1l6KmrKUfMTSPPTKccnOLGs0S2pM tPkASh2b2YOo3dE9ujR6K8p9n2gGBTv6eTYOFgx+I9SdaoZRFnodJAz1zzZyHbVbDi0J d2J0PlIa/oQrw1dKUcN70kmyH8XI6acajmPl2N3lG9tA4Yb3S2dmBMgX0pRu104Fdw2J 9k9sy75oDnIZN4qcta4oIUrGgUAsLNrHWWCbZinYx2WPtjzDVkMjKHp2criPKDdQ//FK pBBg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of gnomes@lxorguk.ukuu.org.uk designates 82.70.14.225 as permitted sender) smtp.mailfrom=gnomes@lxorguk.ukuu.org.uk Authentication-Results: mx.google.com; spf=pass (google.com: domain of gnomes@lxorguk.ukuu.org.uk designates 82.70.14.225 as permitted sender) smtp.mailfrom=gnomes@lxorguk.ukuu.org.uk Date: Thu, 25 Jan 2018 17:09:25 +0000 From: Alan Cox To: Joerg Roedel Cc: Nadav Amit , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , the arch/x86 maintainers , LKML , "open list:MEMORY MANAGEMENT" , Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , jroedel@suse.de Subject: Re: [RFC PATCH 00/16] PTI support for x86-32 Message-ID: <20180125170925.1d72d587@alans-desktop> In-Reply-To: <20180122085625.GE28161@8bytes.org> References: <1516120619-1159-1-git-send-email-joro@8bytes.org> <5D89F55C-902A-4464-A64E-7157FF55FAD0@gmail.com> <886C924D-668F-4007-98CA-555DB6279E4F@gmail.com> <9CF1DD34-7C66-4F11-856D-B5E896988E16@gmail.com> <20180122085625.GE28161@8bytes.org> Organization: Intel Corporation X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1589767841591470697?= X-GMAIL-MSGID: =?utf-8?q?1590585202766481367?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Mon, 22 Jan 2018 09:56:25 +0100 Joerg Roedel wrote: > Hey Nadav, > > On Sun, Jan 21, 2018 at 03:46:24PM -0800, Nadav Amit wrote: > > It does seem that segmentation provides sufficient protection from Meltdown. > > Thanks for testing this, if this turns out to be true for all affected > uarchs it would be a great and better way of protection than enabling > PTI. > > But I'd like an official statement from Intel on that one, as their > recommended fix is still to use PTI. It is: we don't think segmentation works on all processors as a defence. Alan From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id 7DAF06B0005 for ; Thu, 25 Jan 2018 12:10:55 -0500 (EST) Received: by mail-wm0-f70.google.com with SMTP id r9so4271096wme.8 for ; Thu, 25 Jan 2018 09:10:55 -0800 (PST) Received: from fuzix.org (www.llwyncelyn.cymru. [82.70.14.225]) by mx.google.com with ESMTPS id p203si1142247wmb.197.2018.01.25.09.10.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 25 Jan 2018 09:10:54 -0800 (PST) Date: Thu, 25 Jan 2018 17:09:25 +0000 From: Alan Cox Subject: Re: [RFC PATCH 00/16] PTI support for x86-32 Message-ID: <20180125170925.1d72d587@alans-desktop> In-Reply-To: <20180122085625.GE28161@8bytes.org> References: <1516120619-1159-1-git-send-email-joro@8bytes.org> <5D89F55C-902A-4464-A64E-7157FF55FAD0@gmail.com> <886C924D-668F-4007-98CA-555DB6279E4F@gmail.com> <9CF1DD34-7C66-4F11-856D-B5E896988E16@gmail.com> <20180122085625.GE28161@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Joerg Roedel Cc: Nadav Amit , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , the arch/x86 maintainers , LKML , "open list:MEMORY MANAGEMENT" , Linus Torvalds , Andy Lutomirski , Dave Hansen , Josh Poimboeuf , Juergen Gross , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , Brian Gerst , David Laight , Denys Vlasenko , Eduardo Valentin , Greg KH , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Andrea Arcangeli , Waiman Long , jroedel@suse.de On Mon, 22 Jan 2018 09:56:25 +0100 Joerg Roedel wrote: > Hey Nadav, > > On Sun, Jan 21, 2018 at 03:46:24PM -0800, Nadav Amit wrote: > > It does seem that segmentation provides sufficient protection from Meltdown. > > Thanks for testing this, if this turns out to be true for all affected > uarchs it would be a great and better way of protection than enabling > PTI. > > But I'd like an official statement from Intel on that one, as their > recommended fix is still to use PTI. It is: we don't think segmentation works on all processors as a defence. Alan -- 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