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=-3.8 required=3.0 tests=BAYES_00, 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 E2315C433E9 for ; Tue, 2 Feb 2021 14:28:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1CCF64EAC for ; Tue, 2 Feb 2021 14:28:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234462AbhBBO2E (ORCPT ); Tue, 2 Feb 2021 09:28:04 -0500 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]:58846 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234326AbhBBO02 (ORCPT ); Tue, 2 Feb 2021 09:26:28 -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-274-flNrt4sAPICkZEemnUm5Og-1; Tue, 02 Feb 2021 14:24:34 +0000 X-MC-Unique: flNrt4sAPICkZEemnUm5Og-1 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; Tue, 2 Feb 2021 14:24:32 +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; Tue, 2 Feb 2021 14:24:32 +0000 From: David Laight To: 'Josh Poimboeuf' , Nick Desaulniers CC: Julien Thierry , Ard Biesheuvel , Mark Brown , Catalin Marinas , Kees Cook , Linux ARM , linux-efi , "linux-hardening@vger.kernel.org" , LKML , "Mark Rutland" , Masahiro Yamada , Michal Marek , Peter Zijlstra , "raphael.gault@arm.com" , Will Deacon , clang-built-linux , Bill Wendling Subject: RE: [RFC PATCH 12/17] gcc-plugins: objtool: Add plugin to detect switch table on arm64 Thread-Topic: [RFC PATCH 12/17] gcc-plugins: objtool: Add plugin to detect switch table on arm64 Thread-Index: AQHW+Pb1TwqrTbfiDUONrIh7m3kiG6pE6I/Q Date: Tue, 2 Feb 2021 14:24:32 +0000 Message-ID: <7c14b5b8b11241cd8271ba5b3f785c51@AcuMS.aculab.com> References: <20210120173800.1660730-13-jthierry@redhat.com> <20210127221557.1119744-1-ndesaulniers@google.com> <20210127232651.rj3mo7c2oqh4ytsr@treble> <20210201214423.dhsma73k7ccscovm@treble> <20210202000203.rk7lh5mx4aflgkwr@treble> In-Reply-To: <20210202000203.rk7lh5mx4aflgkwr@treble> 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-efi@vger.kernel.org U3RpcnJpbmcgbW9yZSBnb29wIGludG8gdGhlIGhvbGUgLi4uLg0KDQpSZXF1aXJpbmcgZ2NjLXBs dWdpbnMsIG1hdGNoaW5nIGNvbXBpbGVyIHZlcnNpb25zIGFuZCB0aGUNCnNhbWUgJ2R3YXJmJyBm b3JtYXQgZm9yIE9PVCBtb2R1bGVzIGlzIHByb2JhYmx5IHZlcnkgcGFpbmZ1bC4NCg0KSW4gbWFu eSBjYXNlcyAoYW5kIHRoaXMgbWF5IGluY2x1ZGUgZHJpdmVycyByZWxlYXNlZCBieSBzb21lDQpk aXN0cmlidXRpb25zKSBhbiBPT1QgZHJpdmVyIGhhcyB0d28gc2VwYXJhdGUgcGFydHMuDQoNCk9u ZSBwYXJ0IGlzIEMgc291cmNlIHRoYXQgaXMgY29tcGlsZWQgd2hlbiB0aGUgbW9kdWxlIGlzIGJ1 aWx0DQpvbiB0aGUgdGFyZ2V0IHN5c3RlbSBhbmQgYWdhaW5zdCB0aGUgaW5zdGFsbGVkIGtlcm5l bCBoZWFkZXJzLg0KR2V0dGluZyB0aGlzIHRvIG1hdGNoICdqdXN0JyByZWxpZXMgb24gaGF2aW5n IHRoZSBjb3JyZWN0DQpjb21waWxlciAoZXRjKSBpbnN0YWxsZWQgYW5kIGluICRQQVRILg0KDQpU aGUgc2Vjb25kIHBhcnQgaXMgbXVjaCBtb3JlIHByb2JsZW1hdGljLg0KVGhpcyBpcyBqdXN0IGFu IG9iamVjdCBmaWxlIGNvbXBpbGVkIGJ5IGEgdGhpcmQgcGFydHkuDQpJdCBkb2Vzbid0IGRpcmVj dGx5IGRlcGVuZCBvbiBhbnl0aGluZyBkZWZpbmVkIGluIHRoZQ0Ka2VybmVsIGhlYWRlcnMgLSBz byBjYW4gKGN1cnJlbnRseSkgYmUgbGlua2VkIGludG8gYW55DQprZXJuZWwgdmVyc2lvbi4NCg0K SW4gdGhlIHBhc3Qgc29tZSBncmFwaGljcyBkcml2ZXJzIGhhdmUgaGFkIGEgdGhpcmQgcGFydHkN Cm9iamVjdCBmaWxlLg0KSSB0aGluayBzb21lIG9mIHRoZSBsYXB0b3Agd2lmaSBkcml2ZXJzIG1p Z2h0IGFzIHdlbGwuDQoNCk5vdyBJIHNvbWUgcGVvcGxlIHRoaW5rIGV2ZXJ5dGhpbmcgc2hvdWxk IGJlIGZyZWUgc291cmNlLg0KQnV0IHRoZXJlIGFyZSB2YXJpb3VzIGNvbW1lcmNpYWwgYW5kIHBy YWN0aWNhbCByZWFzb25zDQpmb3IgYm90aCBPT1QgZHJpdmVycyBhbmQgb2JqZWN0IGZpbGUgJ2Js b2JzJyBpbiBPT1QgZHJpdmVycy4NCg0KCURhdmlkDQoNCi0NClJlZ2lzdGVyZWQgQWRkcmVzcyBM YWtlc2lkZSwgQnJhbWxleSBSb2FkLCBNb3VudCBGYXJtLCBNaWx0b24gS2V5bmVzLCBNSzEgMVBU LCBVSw0KUmVnaXN0cmF0aW9uIE5vOiAxMzk3Mzg2IChXYWxlcykNCg== 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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 CAB93C433DB for ; Tue, 2 Feb 2021 14:25:57 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8439564E2B for ; Tue, 2 Feb 2021 14:25:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8439564E2B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=ACULAB.COM Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ItzCEz9RaTjxENeOA1A7jJ4uzsmJXoBAFXFa98hEe3g=; b=B0Uzjb/EfxW+cz+339DVjiF6O XSt8+Yyzmr0398aHbbeLCKzpWCPs31gIbkPdcZigy28kn4IYf0To40XwHo0OfwfuTkEALugVHcP57 m5F+4DP5UEx3Z57Pk4CCrq7Lta+RudaHrEuiBot7pt9xMVVWyElyfZ2HaLOTDBXKw6LT1sKFNtSVv K0FyTc3CrHPdihKlcrdCwvtRGiGW5N9SHHECUBAEU3dyBavLcZ2/dQHf5TbyDZQLr/Sg/e2OBjPHe 1CcdCirdh+6guwTksKJ4oiBrokGgsWlf+7qZMReV2iZCWXGzTvbSiuObLm3Ta1fdoRRz0NTBVg0eM pUX0VabwQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6wbk-0000bH-Ix; Tue, 02 Feb 2021 14:24:44 +0000 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6wbh-0000aH-P1 for linux-arm-kernel@lists.infradead.org; Tue, 02 Feb 2021 14:24:43 +0000 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-274-flNrt4sAPICkZEemnUm5Og-1; Tue, 02 Feb 2021 14:24:34 +0000 X-MC-Unique: flNrt4sAPICkZEemnUm5Og-1 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; Tue, 2 Feb 2021 14:24:32 +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; Tue, 2 Feb 2021 14:24:32 +0000 From: David Laight To: 'Josh Poimboeuf' , Nick Desaulniers Subject: RE: [RFC PATCH 12/17] gcc-plugins: objtool: Add plugin to detect switch table on arm64 Thread-Topic: [RFC PATCH 12/17] gcc-plugins: objtool: Add plugin to detect switch table on arm64 Thread-Index: AQHW+Pb1TwqrTbfiDUONrIh7m3kiG6pE6I/Q Date: Tue, 2 Feb 2021 14:24:32 +0000 Message-ID: <7c14b5b8b11241cd8271ba5b3f785c51@AcuMS.aculab.com> References: <20210120173800.1660730-13-jthierry@redhat.com> <20210127221557.1119744-1-ndesaulniers@google.com> <20210127232651.rj3mo7c2oqh4ytsr@treble> <20210201214423.dhsma73k7ccscovm@treble> <20210202000203.rk7lh5mx4aflgkwr@treble> In-Reply-To: <20210202000203.rk7lh5mx4aflgkwr@treble> 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210202_092441_995447_58F415B6 X-CRM114-Status: GOOD ( 11.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Bill Wendling , linux-efi , Julien Thierry , clang-built-linux , Peter Zijlstra , Catalin Marinas , Masahiro Yamada , LKML , Michal Marek , "raphael.gault@arm.com" , Mark Brown , "linux-hardening@vger.kernel.org" , Will Deacon , Ard Biesheuvel , Linux ARM , Kees Cook Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Stirring more goop into the hole .... Requiring gcc-plugins, matching compiler versions and the same 'dwarf' format for OOT modules is probably very painful. In many cases (and this may include drivers released by some distributions) an OOT driver has two separate parts. One part is C source that is compiled when the module is built on the target system and against the installed kernel headers. Getting this to match 'just' relies on having the correct compiler (etc) installed and in $PATH. The second part is much more problematic. This is just an object file compiled by a third party. It doesn't directly depend on anything defined in the kernel headers - so can (currently) be linked into any kernel version. In the past some graphics drivers have had a third party object file. I think some of the laptop wifi drivers might as well. Now I some people think everything should be free source. But there are various commercial and practical reasons for both OOT drivers and object file 'blobs' in OOT drivers. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel