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 5B491C433F5 for ; Tue, 17 May 2022 08:27:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243196AbiEQI1p convert rfc822-to-8bit (ORCPT ); Tue, 17 May 2022 04:27:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243014AbiEQI0s (ORCPT ); Tue, 17 May 2022 04:26:48 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BFC8433E8E for ; Tue, 17 May 2022 01:26:46 -0700 (PDT) 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-206-u0rpxtwWMv-63K0ptBJSiA-1; Tue, 17 May 2022 09:26:43 +0100 X-MC-Unique: u0rpxtwWMv-63K0ptBJSiA-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 15.0.1497.36; Tue, 17 May 2022 09:26:42 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.036; Tue, 17 May 2022 09:26:42 +0100 From: David Laight To: 'Peter Zijlstra' , Mikulas Patocka CC: Linus Torvalds , Josh Poimboeuf , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] objtool: fix objtool regression on x32 systems Thread-Topic: [PATCH] objtool: fix objtool regression on x32 systems Thread-Index: AQHYaWt5OldbokCz9EWxs3iZW4E54K0iu3XQ Date: Tue, 17 May 2022 08:26:42 +0000 Message-ID: <738a941ba2ff4e2db8f2268b281d9bd5@AcuMS.aculab.com> References: <20220516212517.GP76023@worktop.programming.kicks-ass.net> In-Reply-To: <20220516212517.GP76023@worktop.programming.kicks-ass.net> 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: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra > Sent: 16 May 2022 22:25 ... > A quick look seems to suggest at least all the 'offset' fields should be > u64 or something. The only reason that works is because -mcmodel=kernel > keeps everything in the 2G range to make s32 immediates work. But it > isn't right. Offsets in instructions are only 8bit or 32bit. The mod/reg/rm and SiB encodings don't support anything else. If offsets might be large then they have to be loaded into registers - which will slow things down. Immediates can be 64bit (but not if the addressing mode includes an offset). David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)