Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6600C433F5 for ; Sat, 11 Dec 2021 17:01:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231506AbhLKRBP (ORCPT ); Sat, 11 Dec 2021 12:01:15 -0500 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:34034 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230329AbhLKRBO (ORCPT ); Sat, 11 Dec 2021 12:01:14 -0500 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-61-1s9Z_dAWPDe0SOxPMZbbFA-1; Sat, 11 Dec 2021 17:01:08 +0000 X-MC-Unique: 1s9Z_dAWPDe0SOxPMZbbFA-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 15.0.1497.26; Sat, 11 Dec 2021 17:01:07 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.026; Sat, 11 Dec 2021 17:01:07 +0000 From: David Laight To: 'Jann Horn' , Marco Elver , "Peter Zijlstra" , Alexander Potapenko CC: Kees Cook , Thomas Gleixner , Nathan Chancellor , Nick Desaulniers , Elena Reshetova , "Mark Rutland" , Peter Collingbourne , "kasan-dev@googlegroups.com" , "linux-kernel@vger.kernel.org" , "llvm@lists.linux.dev" , "linux-toolchains@vger.kernel.org" Subject: RE: randomize_kstack: To init or not to init? Thread-Topic: randomize_kstack: To init or not to init? Thread-Index: AQHX7UIUmxdq4YrWzkyiG3jb/JAMzqwthFQA Date: Sat, 11 Dec 2021 17:01:07 +0000 Message-ID: References: In-Reply-To: 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 RnJvbTogSmFubiBIb3JuDQo+IFNlbnQ6IDA5IERlY2VtYmVyIDIwMjEgMjE6MTYNCi4uLg0KPiBU aGlzIGRvZXNuJ3QganVzdCBhZmZlY3QgYWxsb2NhKCksIHJpZ2h0PyBBY2NvcmRpbmcgdG8gZ29k Ym9sdC5vcmcNCj4gKGh0dHBzOi8vZ29kYm9sdC5vcmcvei9qWXJXRXg3bzgpOg0KPiANCj4gdm9p ZCBiYXIoY2hhciAqcCk7DQo+IHZvaWQgZm9vKCkgew0KPiAgIGNoYXIgYXJyWzUxMl07DQo+ICAg YmFyKGFycik7DQo+IH0NCj4gDQo+IHdoZW4gY29tcGlsZWQgd2l0aCAiLWZ0cml2aWFsLWF1dG8t dmFyLWluaXQ9cGF0dGVybiAtTzIgLW1uby1zc2UiDQo+IGdpdmVzIHRoaXMgcmVzdWx0Og0KPiAN Cj4gZm9vOiAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICMgQGZvbw0KPiAgICAg ICAgIHB1c2ggICAgcmJ4DQo+ICAgICAgICAgc3ViICAgICByc3AsIDUxMg0KPiAgICAgICAgIG1v diAgICAgcmJ4LCByc3ANCj4gICAgICAgICBtb3YgICAgIGVkeCwgNTEyDQo+ICAgICAgICAgbW92 ICAgICByZGksIHJieA0KPiAgICAgICAgIG1vdiAgICAgZXNpLCAxNzANCj4gICAgICAgICBjYWxs ICAgIG1lbXNldEBQTFQNCj4gICAgICAgICBtb3YgICAgIHJkaSwgcmJ4DQo+ICAgICAgICAgY2Fs bCAgICBiYXINCj4gICAgICAgICBhZGQgICAgIHJzcCwgNTEyDQo+ICAgICAgICAgcG9wICAgICBy YngNCj4gICAgICAgICByZXQNCg0KSmVlcGVycyAtIEkgZG9uJ3QgZXZlciB3YW50IHRoYXQgdG8g aGFwcGVuIG5vdCBldmVyLi4uDQoNClRoZXJlIGlzIHBsZW50eSBvZiB1c2Vyc3BhY2UgY29kZSB0 aGF0IGFsbG9jYXRlcyBsYXJnZSBhcnJheXMgb24gc3RhY2sNCihJIGJldCBzb21lIGdldCBpbnRv IE1CIHNpemVzKSB0aGF0IGFyZSBjb3JyZWN0bHkgYm91bmQtY2hlY2tlZCBidXQNCnRoZSBleHBl bnNlIG9mIGluaXRpYWxpc2luZyB0aGVtIHdpbGwgYmUgaG9ycmlkLg0KDQpTbyB5b3UgZW5kIHVw IHdpdGggaG9ycmlkLCBjb21wbGV4LCBtb3JlIGxpa2VseSB0byBiZSBidWdneSwgY29kZQ0KdGhh dCB0cmllcyB0byBhbGxvY2F0ZSB0aGluZ3MgdGhhdCBhcmUgJ2p1c3QgYmlnIGVub3VnaCcgcmF0 aGVyDQp0aGFuIGp1c3QgYSBzYW5pdHkgY2hlY2sgb24gYSBsYXJnZSBidWZmZXIuDQoNClR5cGlj YWwgZXhhbXBsZXMgYXJlIGNoYXIgcGF0aFtNQVhQQVRIXS4NCllvdSBrbm93IHRoZSBwYXRoIHdp bGwgYWxtb3N0IGNlcnRhaW5seSBiZSA8IDEwMCBieXRlcy4NCk1BWFBBVEggaXMgb3ZlcmtpbGwg LSBidXQgY2FuIGJlIHRlc3RlZCBmb3IuDQpCdXQgeW91IGRvbid0IHdhbnQgcGF0aFtdIGluaXRp YWxpc2VkLg0KU28geW91IGNhbmUgdG8gcGljayBhIHNob3J0ZXIgbGVuZ3RoIC0gYW5kIHRoZW4g aXQgYWxsIGdvZXMgJ1RJVFNVUCcNCndoZW4gdGhlIGFjdHVhbCBwYXRoIGlzIGEgYml0IGxvbmdl ciB0aGFuIHlvdSBhbGxvd2VkIGZvci4NCg0KCURhdmlkDQoNCi0NClJlZ2lzdGVyZWQgQWRkcmVz cyBMYWtlc2lkZSwgQnJhbWxleSBSb2FkLCBNb3VudCBGYXJtLCBNaWx0b24gS2V5bmVzLCBNSzEg MVBULCBVSw0KUmVnaXN0cmF0aW9uIE5vOiAxMzk3Mzg2IChXYWxlcykNCg==