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 A082EC4167B for ; Fri, 16 Dec 2022 16:58:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231565AbiLPQ6E convert rfc822-to-8bit (ORCPT ); Fri, 16 Dec 2022 11:58:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231572AbiLPQ6B (ORCPT ); Fri, 16 Dec 2022 11:58:01 -0500 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77F81554CC for ; Fri, 16 Dec 2022 08:57:59 -0800 (PST) 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-166-U7g6z6JKOyy0PafMZYBSdA-1; Fri, 16 Dec 2022 16:57:57 +0000 X-MC-Unique: U7g6z6JKOyy0PafMZYBSdA-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Fri, 16 Dec 2022 16:57:54 +0000 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.044; Fri, 16 Dec 2022 16:57:54 +0000 From: David Laight To: 'Steven Rostedt' CC: 'Andreas Schwab' , "'Leizhen (ThunderTown)'" , Geert Uytterhoeven , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , "Joe Lawrence" , "live-patching@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Masahiro Yamada , Alexei Starovoitov , Jiri Olsa , Kees Cook , Andrew Morton , "Luis Chamberlain" , "linux-modules@vger.kernel.org" , Ingo Molnar , linux-m68k , "Jason A. Donenfeld" Subject: RE: [PATCH v9] kallsyms: Add self-test facility Thread-Topic: [PATCH v9] kallsyms: Add self-test facility Thread-Index: AQHZEWkbzV5WljPUpEGVjsixemOWL65wtOBggAAGFACAAAApIA== Date: Fri, 16 Dec 2022 16:57:54 +0000 Message-ID: References: <20221115083349.1662-1-thunder.leizhen@huawei.com> <49070ac3-02bb-a3b3-b929-ede07e3b2c95@huawei.com> <4aaede14-8bd3-6071-f17b-7efcb5f0de42@huawei.com> <66ec4021-b633-09ba-73ee-b24cdb3fa25a@huawei.com> <06345dca-0afb-00a5-c9e9-5ba830d8ad05@huawei.com> <52450ec1da164d6d87587063c3b3d3d2@AcuMS.aculab.com> <592dce7a0de24c62bd31c29f86ce6c1b@AcuMS.aculab.com> <87pmcjidfe.fsf@igel.home> <1ba1fadb39994a4d91edabdfd9d69fa6@AcuMS.aculab.com> <87len7ibtt.fsf@igel.home> <87fsdfib07.fsf@igel.home> <819801284eb745d9a4189759bad297f5@AcuMS.aculab.com> <20221216115314.6120beb7@gandalf.local.home> In-Reply-To: <20221216115314.6120beb7@gandalf.local.home> 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: 8BIT Precedence: bulk List-ID: From: Steven Rostedt > Sent: 16 December 2022 16:53 > > On Fri, 16 Dec 2022 16:32:08 +0000 > David Laight wrote: > > > From: Andreas Schwab > > > Sent: 16 December 2022 16:12 > > > On Dez 16 2022, David Laight wrote: > > > > > > > The other issue is a missing "memory" clobber. > > > > > > strcmp is a pure read-only operation. > > > > Still needs the memory clobber. > > What memory is being modified? > > I don't know m68k assembly, but I'm guessing the (%O)+ and the (%1)+ only > modifies the register being used, and no memory is being touched. Memory is being read so a clobber is needed to ensure that all pending writes have been done. Although, in this case, the memory being read is effectively read only so nothing should be pending. But it really does look like something is 'smelly' with the constraints. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)