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=-0.8 required=3.0 tests=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 0A14AC43603 for ; Fri, 20 Dec 2019 10:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE9B824683 for ; Fri, 20 Dec 2019 10:59:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727279AbfLTK7h (ORCPT ); Fri, 20 Dec 2019 05:59:37 -0500 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]:59824 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727177AbfLTK7h (ORCPT ); Fri, 20 Dec 2019 05:59:37 -0500 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-6-_nn-FqbbNh-qOyl_rRohbA-1; Fri, 20 Dec 2019 10:59:34 +0000 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Fri, 20 Dec 2019 10:59:33 +0000 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Fri, 20 Dec 2019 10:59:33 +0000 From: David Laight To: 'Andy Lutomirski' CC: Brian Gerst , Andy Lutomirski , X86 ML , LKML , Ingo Molnar , "H . Peter Anvin" , Boris Ostrovsky , Oleg Nesterov Subject: RE: [PATCH] x86: Remove force_iret() Thread-Topic: [PATCH] x86: Remove force_iret() Thread-Index: AQHVtuhWtS7aVpT6VkyrDyqz06b2R6fCyteggAAITICAAAFfwA== Date: Fri, 20 Dec 2019 10:59:33 +0000 Message-ID: <227c8442919d44a790370870aaba416c@AcuMS.aculab.com> References: <431a146f6461402da61d09fff155f35b@AcuMS.aculab.com> In-Reply-To: Accept-Language: en-GB, en-US Content-Language: 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 X-MC-Unique: _nn-FqbbNh-qOyl_rRohbA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: base64 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org RnJvbTogQW5keSBMdXRvbWlyc2tpDQo+IFNlbnQ6IDIwIERlY2VtYmVyIDIwMTkgMTA6MzANCj4g PiBPbiBEZWMgMjAsIDIwMTksIGF0IDY6MTAgUE0sIERhdmlkIExhaWdodCA8RGF2aWQuTGFpZ2h0 QGFjdWxhYi5jb20+IHdyb3RlOg0KPiA+DQo+ID4g77u/RnJvbTogQnJpYW4gR2Vyc3QNCj4gPj4g U2VudDogMjAgRGVjZW1iZXIgMjAxOSAwMzo0OA0KPiA+Pj4gT24gVGh1LCBEZWMgMTksIDIwMTkg YXQgODo1MCBQTSBBbmR5IEx1dG9taXJza2kgPGx1dG9Aa2VybmVsLm9yZz4gd3JvdGU6DQo+ID4+ Pg0KPiA+Pj4gT24gVGh1LCBEZWMgMTksIDIwMTkgYXQgMzo1OCBBTSBCcmlhbiBHZXJzdCA8YnJn ZXJzdEBnbWFpbC5jb20+IHdyb3RlOg0KPiA+Pj4+DQo+ID4+Pj4gZm9yY2VfaXJldCgpIHdhcyBv cmlnaW5hbGx5IGludGVuZGVkIHRvIHByZXZlbnQgdGhlIHJldHVybiB0byB1c2VyIG1vZGUgd2l0 aA0KPiA+Pj4+IHRoZSBTWVNSRVQgb3IgU1lTRVhJVCBpbnN0cnVjdGlvbnMsIGluIGNhc2VzIHdo ZXJlIHRoZSByZWdpc3RlciBzdGF0ZSBjb3VsZA0KPiA+Pj4+IGhhdmUgYmVlbiBjaGFuZ2VkIHRv IGJlIGluY29tcGF0aWJsZSB3aXRoIHRob3NlIGluc3RydWN0aW9ucy4NCj4gPj4+DQo+ID4+PiBJ dCdzIG1vcmUgdGhhbiB0aGF0LiAgQmVmb3JlIHRoZSBiaWcgc3lzY2FsbCByZXdvcmssIHdlIGRp ZG4ndCByZXN0b3JlDQo+ID4+PiB0aGUgY2FsbGVyLXNhdmVkIHJlZ3MuICBTZWU6DQo+ID4+Pg0K PiA+Pj4gY29tbWl0IDIxZDM3NWI2YjM0ZmY1MTFhNTA3ZGUyN2JmMzE2YjNkZGU2OTM4ZDkNCj4g Pj4+IEF1dGhvcjogQW5keSBMdXRvbWlyc2tpIDxsdXRvQGtlcm5lbC5vcmc+DQo+ID4+PiBEYXRl OiAgIFN1biBKYW4gMjggMTA6Mzg6NDkgMjAxOCAtMDgwMA0KPiA+Pj4NCj4gPj4+ICAgIHg4Ni9l bnRyeS82NDogUmVtb3ZlIHRoZSBTWVNDQUxMNjQgZmFzdCBwYXRoDQo+ID4+Pg0KPiA+Pj4gU28g aWYgeW91IGNoYW5nZWQgcjEyLCBmb3IgZXhhbXBsZSwgdGhlIGNoYW5nZSB3b3VsZCBnZXQgbG9z dC4NCj4gPj4NCj4gPj4gZm9yY2VfaXJldCgpIHNwZWNpZmljYWxseSBkZWFsdCB3aXRoIGNoYW5n ZXMgdG8gQ1MsIFNTIGFuZCBFRkxBR1MuDQo+ID4+IFNhdmluZyBhbmQgcmVzdG9yaW5nIHRoZSBl eHRyYSByZWdpc3RlcnMgd2FzIGEgZGlmZmVyZW50IHByb2JsZW0NCj4gPj4gYWx0aG91Z2ggaXQg YWZmZWN0ZWQgdGhlIHNhbWUgZnVuY3Rpb25zIGxpa2UgcHRyYWNlLCBzaWduYWxzLCBhbmQNCj4g Pj4gZXhlYy4NCj4gPg0KPiA+IElzIGl0IGV2ZXIgcG9zc2libGUgZm9yIGFueSBvZiB0aGUgc2Vn bWVudCByZWdpc3RlcnMgdG8gcmVmZXIgdG8gdGhlIExEVA0KPiA+IGFuZCBmb3IgYW5vdGhlciB0 aHJlYWQgdG8gaW52YWxpZGF0ZSB0aGUgZW50cmllcyAndmVyeSBsYXRlJyA/DQo+IA0KPiBOb3Qg aW4gbmV3ZXIga2VybmVscywgYmVjYXVzZSB0aGUgYWN0dWFsIExEVCBpcyBuZXZlciBtb2RpZmll ZC4NCj4gSW5zdGVhZCwgTERUIGNoYW5nZXMgY3JlYXRlIGEgd2hvbGUgbmV3IExEVCBhbmQgcHJv cGFnYXRlIGl0IHdpdGggYW4gSVBJLg0KDQpDYW4gdGhlIElQSSBiZSBkaXNhYmxlZCB0aHJvdWdo IHRoZSBTWVNSRVQgcGF0aD8NCk9uY2UgaW4gdXNlciBzcGFjZSwgdGhlIElQSSB3aWxsIGludGVy cnVwdCB0aGUgcHJvY2VzcyBhbmQsIEkgcHJlc3VtZSwgaXQgd2lsbA0KcGljayB1cCB0aGUgbmV3 IExEVCBvbiAncmV0dXJuIHRvIHVzZXInLg0KQnV0IGlmIHRoZSBJUEkgaGFwcGVucyBiZXR3ZWVu IHRoZSBMRFQgYmVpbmcgc2V0IGFuZCBTWVNSRVQgaXQgd2lsbCAocHJlc3VtYWJseSkNCnJlbWFp biAncGVuZGluZycgdW50aWwgdGhlIG5leHQgc3lzdGVtIGNhbGw/DQpXaGljaCBjb3VsZCBiZSBs b25nIGVub3VnaCBmb3Igb25lIHRocmVhZCB0byBoYXZlIHBhc3NlZCBhIHBvaW50ZXIgYWNyb3Nz IGdpdmluZw0KYW4gdW5leHBlY3RlZCBTRUdWIChvciBtYXliZSB3b3JzZSwgZmFpbGluZyB0byBn aXZlIGFuIGV4cGVjdGVkIG9uZSkuDQoNCj4gQnV0IHRoZSBJUkVUIHBhdGggY2FuIGZhaWwgZHVl IHRvIGNoYW5nZXMgdG8gdGhlIHNlbGVjdG9ycyB3aGlsZSBpbiB0aGUga2VybmVsLCBkdWUgdG8g c2lncmV0dXJuIG9yIHB0cmFjZS4gIFdlIGhhdmUgZGVsaWdodGZ1bCBzZWxmdGVzdHMNCj4gZm9y IHRoaXMuDQo+IA0KPiA+DQo+ID4gU28gZXZlbiB0aG91Z2ggdGhlIHZhbHVlcyB3ZXJlIHZhbGlk IHdoZW4gY2hhbmdlZCwgdGhleSBhcmUNCj4gPiBpbnZhbGlkIGR1cmluZyB0aGUgJ3JldHVybiB0 byB1c2VyJyBzZXF1ZW5jZS4NCj4gPg0KPiA+IEkgcmVtZW1iZXIgd3JpdGluZyBhIHNpZ25hbCBo YW5kbGVyIHRoYXQgJ2NvcnJ1cHRlZCcgYWxsIHRoZQ0KPiA+IHNlZ21lbnQgcmVnaXN0ZXJzIChl dGMpIGFuZCBmaXhpbmcgdGhlIE5ldEJTRCBrZXJuZWwgdG8gaGFuZGxlDQo+ID4gYWxsIHRoZSBm YXVsdHMgcmVzdG9yaW5nIHRoZSBzZWdtZW50IHJlZ2lzdGVycyBhbmQgSVJFVCBmYXVsdGluZw0K PiA+IGluIGtlcm5lbCAoSUlSQyBpbnZhbGlkIHVzZXIgJVNTIG9yICVDUykuDQo+ID4gKElSRVQg Y2FuIGFsc28gZmF1bHQgaW4gdXNlciBzcGFjZSwgYnV0IHRoYXQgaXMgYSBub3JtYWwgZmF1bHQu KQ0KPiANCj4gRGlkIHlvdSByZW1lbWJlciB0byB0ZXN0IHRoZSAjTlAgY2FzZT8gIE1hbnkga2Vy bmVscyBmb3Jnb3QgdGhhdCB0aGlzIHdhcyBwb3NzaWJsZSA6KQ0KDQpUaGF0IG1pZ2h0IGhhdmUg YmVlbiB3aHkgSSB3YXMgZml4aW5nIGl0Lg0KSSBjZXJ0YWlubHkgdGVzdGVkIHRoZSBjYXNlcyB3 aGVyZSBsb2FkaW5nIHRoZSB1c2VyIHNlZ21lbnQgcmVnaXN0ZXJzIGZhdWx0ZWQgaW4ga2VybmVs DQooYWZ0ZXIgbG9hZGluZyB0aGUgdXNlci1HUykgYW5kIHdoZXJlIElSRVQgZmF1bHRlZCBpbiBr ZXJuZWwuDQpJIGZpeGVkIHVwIHRoZSBzdGFjayBpbiB0aGUgaW50ZXJydXB0IGVudHJ5IGNvZGUg dG8gbWFrZSBpdCBhbGwgYXBwZWFyIHRvIGJlIGEgZmF1bHQNCmluIHVzZXItc3BhY2UgKGRlbGV0 aW5nIG9uZSBvZiB0aGUgdHJhcCBmcmFtZXMpLg0KVGhpcyBhbHNvIHN0b3BzIHJlcGVhdGVkIGZh dWx0cyBnZXR0aW5nIGZ1cnRoZXIgYW5kIGZ1cnRoZXIgZG93biB0aGUga2VybmVsIHN0YWNrLg0K DQo+ID4gSXMgaXQgYWN0dWFsbHkgY2hlYXBlciB0byBwcm9wZXJseSB2YWxpZGF0ZSB0aGUgc2Vn bWVudCByZWdpc3RlcnMsDQo+ID4gb3IgdGFrZSB0aGUgJ2hpdCcgb2YgdGhlIHNsaWdodGx5IHNs b3dlciBJUkVUIHBhdGggYW5kIGdldCB0aGUgY3B1DQo+ID4gdG8gZG8gaXQgZm9yIHlvdT8NCj4g DQo+IFRoZSB2YWxpZGF0aW9uIHdl4oCZcmUgdGFsa2luZyBhYm91dCBpcyBmb3IgU1lTUkVULCBu b3QgSVJFVC4gIEl0IGhhcyBpdHMgb3duIHNldCBvZiBuYXN0eSBjb25kaXRpb25zIGludm9sdmlu ZyBFRkxBR1MsIFIxMSwgUklQLCBhbmQgUkNYLg0KPiBGb3J0dW5hdGVseSBubyBzZWdtZW50cyBh cmUgaW52b2x2ZWQuIFRoZSBhbGdvcml0aG0gaXMsIHJvdWdobHk6DQo+IA0KPiBpZiAob2theSBm b3IgU1lTUkVUKSB7DQo+ICAgU1lTUkVUIChhbmQgYXNzdW1lIGl0IGNhbuKAmXQgZmFpbCkNCj4g fSBlbHNlIHsNCj4gICBpZiAobmVlZCBFU1BGSVgpDQo+ICAgIEhvcnJpYmxlIGhhY2tzOw0KPiAg IElSRVQ7DQo+IH0NCg0KT2ssIEkgd2FzIHBhcnQgd29ycmllZCB5b3Ugd2VyZSBmb3JjaW5nICdv a2F5IGZvciBTWVNSRVQnIHRvIDEuDQogDQo+IEFuZCB3ZSBoYW5kbGUgI0dQLCAjU1MsICNOUCBh bmQgI0RGIGZyb20gSVJFVC4gQW5kIHdlIGhhdmUgc2VsZnRlc3RzIGZvciBhbGwgb2YgdGhpcy4N Cg0KWWVzLCBpdCB3b3VsZCBiZSBiZXN0IGlmIElSRVQgb25seSBldmVyIGZhdWx0ZWQgaW4gdXNl ci1zcGFjZS4NCg0KPiBBbmQgbm8gb25lIHJ1bnMgdGhlIGJsb29keSBzZWxmdGVzdHMgb24gMzIt Yml0IGtlcm5lbHMsIHJlc3VsdGluZyBpbiB0cnVseSBhd2Z1bCBidWdzLg0KDQpJIHN1c3BlY3Qg SSBkaWRuJ3QgdHJ5IGhhcmQgZW5vdWdoIHRvIGdldCBGUy9HUyBhbmQgRlNCQVNFL0dTQkFTRSBj b3JyZWN0bHkgcmVzdG9yZWQuDQooR2l2ZW4gdGhhdCB0aGUgc2VnbWVudCBkZXNjcmlwdG9ycyBt YXkgbm90IGNvbnRhaW4gdGhlIHJlcXVpcmVkIHZhbHVlcy4pDQoNCj4gV2UgY2Fu4oCZdCBoYW5k bGUgI0dQIGZyb20gU1lTUkVULiBUaGFua3MsIEludGVsLg0KPiANCj4gKEFNRCBnZXRzIHRoaXMg bW9yZSByaWdodC4gU1lTUkVUIGlzIHN0aWxsIGEgdHVyZCwgYnV0IGl0IGNhbuKAmXQgZmF1bHQu IEludGVsIGhhbmRsZXMgUklQIGNhbm9uaWNhbCBjaGVja3MgZGlmZmVyZW50bHkgZnJvbSBBTUQs IGFuZCBTWVNSRVQNCj4gd2lsbCAjR1AgaWYgUkNYIGlzIG5vbmNhbm9uaWNhbC4gIFRoZSByZXN1 bHQgd2FzIHByaXZpbGVnZSBlc2NhbGF0aW9uIG9uIGJhc2ljYWxseSBldmVyeSBPUyB3aGVuIHRo aXMgd2FzIG5vdGljZWQuKQ0KDQpZZXMsIGFsbCB0aGUgJ2Zhc3Qgc3lzdGVtIGNhbGwnIGluc3Ry dWN0aW9ucyB3ZXJlIGJhZGx5IHRob3VnaHQgb3V0Lg0KDQoJRGF2aWQNCg0KLQ0KUmVnaXN0ZXJl ZCBBZGRyZXNzIExha2VzaWRlLCBCcmFtbGV5IFJvYWQsIE1vdW50IEZhcm0sIE1pbHRvbiBLZXlu ZXMsIE1LMSAxUFQsIFVLDQpSZWdpc3RyYXRpb24gTm86IDEzOTczODYgKFdhbGVzKQ0K