From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90FE4C433B4 for ; Wed, 5 May 2021 13:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53BB3613AA for ; Wed, 5 May 2021 13:51:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232923AbhEENwK (ORCPT ); Wed, 5 May 2021 09:52:10 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:53194 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231265AbhEENwI (ORCPT ); Wed, 5 May 2021 09:52:08 -0400 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-177-z7GzCxiKMCmwap03myQkMA-1; Wed, 05 May 2021 14:51:08 +0100 X-MC-Unique: z7GzCxiKMCmwap03myQkMA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 5 May 2021 14:51:07 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.015; Wed, 5 May 2021 14:51:07 +0100 From: David Laight To: 'Josh Poimboeuf' CC: Al Viro , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Linus Torvalds , Will Deacon , Dan Williams , Andrea Arcangeli , "Waiman Long" , Peter Zijlstra , "Thomas Gleixner" , Andrew Cooper , Andy Lutomirski , Christoph Hellwig , "Mark Rutland" , Borislav Petkov Subject: RE: [PATCH v4 3/4] x86/uaccess: Use pointer masking to limit uaccess speculation Thread-Topic: [PATCH v4 3/4] x86/uaccess: Use pointer masking to limit uaccess speculation Thread-Index: AQHXQWJqu8vqbxm3x0CYXgd0hdGkc6rUkPgwgAA+HoCAABP/4A== Date: Wed, 5 May 2021 13:51:06 +0000 Message-ID: References: <5ba93cdbf35ab40264a9265fc24575a9b2f813b3.1620186182.git.jpoimboe@redhat.com> <2f75c496ac774444b75ff808854b8e5f@AcuMS.aculab.com> <20210505131943.ci2svd6fmb22y7ac@treble> In-Reply-To: <20210505131943.ci2svd6fmb22y7ac@treble> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RnJvbTogSm9zaCBQb2ltYm9ldWYNCj4gU2VudDogMDUgTWF5IDIwMjEgMTQ6MjANCi4uLg0KPiA+ IGFjY2Vzc19vaygpIGFuZCBtYXNrX3VzZXJfcHRyKCkgYXJlIGRvaW5nIG11Y2ggdGhlIHNhbWUg Y2hlY2suDQo+ID4gSXMgdGhlcmUgc2NvcGUgZm9yIG1ha2luZyBhY2Nlc3Nfb2soKSByZXR1cm4g dGhlIG1hc2tlZCBwb2ludGVyPw0KPiA+DQo+ID4gU28gdGhlIGNhbm9uaWNhbCBjYWxsaW5nIGNv ZGUgd291bGQgYmU6DQo+ID4gCXVwdHIgPSBhY2Nlc3Nfb2sodXB0ciwgc2l6ZSk7DQo+ID4gCWlm ICghdXB0cikNCj4gPiAJCXJldHVybiAtRUZBVUxUOw0KPiA+DQo+ID4gVGhpcyB3b3VsZCBlcnJv ciByZXF1ZXN0cyBmb3IgYWRkcmVzcyAwIGVhcmxpZXIgLSBidXQgSSBkb24ndA0KPiA+IGJlbGll dmUgdGhleSBhcmUgZXZlciB2YWxpZCBpbiBMaW51eC4NCj4gPiAoU29tZSBoaXN0b3JpYyB4ODYg YS5vdXQgZm9ybWF0cyBkaWQgbG9hZCB0byBhZGRyZXNzIDAuKQ0KPiA+DQo+ID4gQ2xlYXJseSBm b3IgYSBmb2xsb3cgdXAgcGF0Y2guDQo+IA0KPiBZZWFoLiAgSSBtZW50aW9uZWQgYSBzaW1pbGFy IGlkZWEgaW4gdGhlIGNvdmVyIGxldHRlci4NCj4gDQo+IEJ1dCBJJ20gdGhpbmtpbmcgd2Ugc2hv dWxkIHN0aWxsIHJlbmFtZSBpdCB0byBhY2Nlc3Nfb2tfbWFzaygpLCBvcg0KPiBvdGhlcndpc2Ug Y2hhbmdlIHRoZSBBUEkgdG8gYXZvaWQgdGhlIG1hc2tlZCB2YWx1ZSBnZXR0aW5nIGlnbm9yZWQu DQoNClNvbWV0aGluZyBsaWtlOg0KCWlmIChhY2Nlc3Nfb2tfbWFzaygmdWFkZHIsIHNpemUpKQ0K CQlyZXR1cm4gLUVGQVVMVDsNCm1pZ2h0IHdvcmsuDQoNCj4gQnV0IHRoYXQnbGwgYmUgYSBtdWNo IGJpZ2dlciBwYXRjaC4NCg0KVHJ1ZSAtIGFuZCB3b3VsZCBuZWVkIHRvIGJlIGRvbmUgaXMgc3Rh Z2VzLg0KDQpUaGUgb3RoZXIgb3B0aW1pc2F0aW9uIGlzIGZvciBzaG9ydC9zZXF1ZW50aWFsIGFj Y2Vzc2VzLg0KSW4gcGFydGljdWxhciBnZXRfdXNlcigpIGFuZCBjb3B5X2Zyb21fdXNlcigpLg0K SGVyZSB0aGUgJ3NpemUnIGFyZ3VtZW50IGNhbiBvZnRlbiBiZSBhdm9pZGVkLg0KRWl0aGVyIGJl Y2F1c2Ugb25seSB0aGUgYmFzZSBhZGRyZXNzIGlzIGV2ZXIgYWNjZXNzZWQsIG9yIHRoZQ0Ka2Vy bmVsIGd1YXJhbnRlZXMgYW4gdW5tYXBwZWQgcGFnZSBiZXR3ZWVuIHVzZXIgYW5kIGtlcm5lbCBh ZGRyZXNzZXMuDQoNCklJUkMgeDg2IGhhcyB0byBoYXZlIGFuIHVubWFwcGVkIHBhZ2UgYmVjYXVz ZSBvZiAnaXNzdWVzJyB3aXRoDQpwcmVmZXRjaCBhY3Jvc3MgdGhlIGJvdW5kYXJ5Lg0KSSBkb24n dCBrbm93IGlmIGl0IGlzIG9uIHRoZSB1c2VyIG9yIGtlcm5lbCBzaWRlIC0gZG9lc24ndCByZWFs bHkgbWF0dGVyLg0KDQpBbHNvIGZvciB0eXBpY2FsIDY0Yml0IGFyY2hpdGVjdHVyZXMgd2hlcmUg dGhlcmUgaXMgYSBiaWcgYWRkcmVzcyBob2xlDQphcm91bmQgMXVsIDw8IDYzLCBhY2Nlc3Nfb2so KSBjYW4ganVzdCBjaGVjayAoZm9yIGV4YW1wbGUpOg0KCWlmICgoKGxvbmcpdWFkZHIgfCBzaXpl KSAmIH4wdWwgPDwgNTYpDQoJCXJldHVybiAtRUZBVUxULg0KKGNoYW5nZSB0aGUgNTYgdG8gbWF0 Y2ggdGhlIFRBU0tfU0laRV9NQVgpLg0KVGhlIGNvbXBpbGVyIHdpbGwgdGhlbiBvcHRpbWlzZSBh d2F5IGFueSBjb25zdGFudCBzaXplLg0KDQoJRGF2aWQNCg0KLQ0KUmVnaXN0ZXJlZCBBZGRyZXNz IExha2VzaWRlLCBCcmFtbGV5IFJvYWQsIE1vdW50IEZhcm0sIE1pbHRvbiBLZXluZXMsIE1LMSAx UFQsIFVLDQpSZWdpc3RyYXRpb24gTm86IDEzOTczODYgKFdhbGVzKQ0K