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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D0ADEE4996 for ; Mon, 21 Aug 2023 08:39:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234061AbjHUIjQ (ORCPT ); Mon, 21 Aug 2023 04:39:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48654 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232246AbjHUIjQ (ORCPT ); Mon, 21 Aug 2023 04:39:16 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D675BC9 for ; Mon, 21 Aug 2023 01:39:00 -0700 (PDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-219-jEAS19mCMs2MDf8c5jt4Eg-1; Mon, 21 Aug 2023 09:38:54 +0100 X-MC-Unique: jEAS19mCMs2MDf8c5jt4Eg-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Mon, 21 Aug 2023 09:38:43 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Mon, 21 Aug 2023 09:38:43 +0100 From: David Laight To: 'Alejandro Colomar' , "Gustavo A. R. Silva" , Kees Cook , "Gustavo A. R. Silva" CC: LKML , "linux-hardening@vger.kernel.org" Subject: RE: struct_size() using sizeof() vs offsetof() Thread-Topic: struct_size() using sizeof() vs offsetof() Thread-Index: AQHZ0ToJGRMQ8qLPnk+BhbrlQvigaK/0cK8g Date: Mon, 21 Aug 2023 08:38:43 +0000 Message-ID: References: <74e8cf91-d095-33e3-c548-34d80b691089@kernel.org> <202308161913.91369D4A@keescook> <09b4a2ce-da74-3a19-6961-67883f634d98@kernel.org> 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 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-hardening@vger.kernel.org RnJvbTogQWxlamFuZHJvIENvbG9tYXIgPGFseEBrZXJuZWwub3JnPg0KPiBTZW50OiBUaHVyc2Rh eSwgQXVndXN0IDE3LCAyMDIzIDc6MzggUE0NCj4gDQo+IEhpIEd1c3Rhdm8sDQo+IA0KPiBPbiAy MDIzLTA4LTE3IDE4OjA1LCBHdXN0YXZvIEEuIFIuIFNpbHZhIHdyb3RlOg0KPiA+DQo+ID4+IC0g ICAgICAgICAgICAgICB0cF9jID0ga3phbGxvYyhzaXplb2YoKnRwX2MpLCBHRlBfS0VSTkVMKTsN Cj4gPj4gKyAgICAgICAgICAgICAgIHRwX2MgPSBremFsbG9jKHN0cnVjdF9zaXplKHRwX2MsIGhs aXN0LT5odCwgMSksIEdGUF9LRVJORUwpOw0KPiA+DQo+ID4gSSBqdXN0IHNlbnQgYSBmaXhbMV0u DQo+ID4NCj4gPiBUaGFua3MgZm9yIHJlcG9ydGluZyB0aGlzISA6KQ0KDQpQZXJoYXBzIHN0cnVj dF9zaXplKCkgc2hvdWxkIGluY2x1ZGUgYW4gYXNzZXJ0aW9uIHRoYXQ6DQoJKG9mZnNldG9mKHR5 cGUsIGZpZWxkWzhdKSA+IHNpemVvZiAodHlwZSkpDQpUaGF0IHdpbGwgZW5zdXJlIHRoYXQgZmll bGQgaXMgYW4gYXJyYXkgbWVtYmVyIGFuZCByZWFzb25hYmx5DQpuZWFyIHRoZSBlbmQgb2YgdGhl IHN0cnVjdHVyZS4NCg0KQSBtb3JlIGNvbXBsZXggY2FsY3VsYXRpb24gKHVzaW5nIF9BbGlnbm9m KHR5cGUpIGFuZCB0aGUgb2Zmc2V0L3NpemUNCm9mIGZpZWxkKSBjb3VsZCBiZSB1c2VkLg0KQnV0 IEkgZG9uJ3QgdGhpbmsgeW91IGNhbiBhY3R1YWxseSBkZXRlY3QgaXQgaXMgZmllbGRbXSAob3Ig ZXZlbiB0aGUNCmxhc3QgbWVtYmVyKS4NCg0KCURhdmlkDQoNCi0NClJlZ2lzdGVyZWQgQWRkcmVz cyBMYWtlc2lkZSwgQnJhbWxleSBSb2FkLCBNb3VudCBGYXJtLCBNaWx0b24gS2V5bmVzLCBNSzEg MVBULCBVSw0KUmVnaXN0cmF0aW9uIE5vOiAxMzk3Mzg2IChXYWxlcykNCg==