From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762016AbcAKXsT (ORCPT ); Mon, 11 Jan 2016 18:48:19 -0500 Received: from mga04.intel.com ([192.55.52.120]:57264 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761989AbcAKXsO (ORCPT ); Mon, 11 Jan 2016 18:48:14 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,555,1444719600"; d="scan'208";a="631903297" From: "Luck, Tony" To: Brian Gerst , Andy Lutomirski CC: "Williams, Dan J" , Borislav Petkov , X86 ML , "linux-mm@kvack.org" , Robert , Andrew Morton , Ingo Molnar , "linux-kernel@vger.kernel.org" , linux-nvdimm Subject: RE: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Thread-Topic: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Thread-Index: AQHRSoCIGA3XlVHyGUqV3dZ3k9X68Z7zD+iAgAAOWwCAACLqAIAEOkEA//+DnwA= Date: Mon, 11 Jan 2016 23:48:12 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F39FAA697@ORSMSX114.amr.corp.intel.com> References: <3a259f1cce4a3c309c2f81df715f8c2c9bb80015.1452297867.git.tony.luck@intel.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiNWMxOWM3MmQtYWQ1NC00NGI1LTkzMzktNjE1OWI0ZmRjMzkyIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjQuMTAuMTkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiRmswVituZXIzUVRNTWR3aE9Mb0hmMTNqTkJFMG9NWWtVXC9DMG9TeGk5STA9In0= x-ctpclassification: CTP_IC x-originating-ip: [10.22.254.140] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u0BNmOS2004096 > I agree that for at least put_user() using asm goto would be an even > better option. get_user() on the other hand, will be much messier to > deal with, since asm goto statements can't have outputs, plus it > zeroes the output register on fault. get_user() is the much more interesting one for me. A read from a poisoned user address that generates a machine check is something that can be recovered (kill the process). A write to user space doesn't even generate a machine check. -Tony From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id 1BAB9680F7F for ; Mon, 11 Jan 2016 18:48:24 -0500 (EST) Received: by mail-pa0-f48.google.com with SMTP id ho8so68131755pac.2 for ; Mon, 11 Jan 2016 15:48:24 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id r79si25913755pfb.75.2016.01.11.15.48.23 for ; Mon, 11 Jan 2016 15:48:23 -0800 (PST) From: "Luck, Tony" Subject: RE: [PATCH v8 1/3] x86: Expand exception table to allow new handling options Date: Mon, 11 Jan 2016 23:48:12 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F39FAA697@ORSMSX114.amr.corp.intel.com> References: <3a259f1cce4a3c309c2f81df715f8c2c9bb80015.1452297867.git.tony.luck@intel.com> In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Brian Gerst , Andy Lutomirski Cc: "Williams, Dan J" , Borislav Petkov , X86 ML , "linux-mm@kvack.org" , Robert , Andrew Morton , Ingo Molnar , "linux-kernel@vger.kernel.org" , linux-nvdimm PiBJIGFncmVlIHRoYXQgZm9yIGF0IGxlYXN0IHB1dF91c2VyKCkgdXNpbmcgYXNtIGdvdG8gd291 bGQgYmUgYW4gZXZlbg0KPiBiZXR0ZXIgb3B0aW9uLiAgZ2V0X3VzZXIoKSBvbiB0aGUgb3RoZXIg aGFuZCwgd2lsbCBiZSBtdWNoIG1lc3NpZXIgdG8NCj4gZGVhbCB3aXRoLCBzaW5jZSBhc20gZ290 byBzdGF0ZW1lbnRzIGNhbid0IGhhdmUgb3V0cHV0cywgcGx1cyBpdA0KPiB6ZXJvZXMgdGhlIG91 dHB1dCByZWdpc3RlciBvbiBmYXVsdC4NCg0KZ2V0X3VzZXIoKSBpcyB0aGUgbXVjaCBtb3JlIGlu dGVyZXN0aW5nIG9uZSBmb3IgbWUuIEEgcmVhZCBmcm9tDQphIHBvaXNvbmVkIHVzZXIgYWRkcmVz cyB0aGF0IGdlbmVyYXRlcyBhIG1hY2hpbmUgY2hlY2sgaXMgc29tZXRoaW5nDQp0aGF0IGNhbiBi ZSByZWNvdmVyZWQgKGtpbGwgdGhlIHByb2Nlc3MpLiAgQSB3cml0ZSB0byB1c2VyIHNwYWNlIGRv ZXNuJ3QNCmV2ZW4gZ2VuZXJhdGUgYSBtYWNoaW5lIGNoZWNrLg0KDQotVG9ueQ0K -- 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