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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 E4E5EC10F13 for ; Thu, 11 Apr 2019 08:18:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD22420873 for ; Thu, 11 Apr 2019 08:18:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726624AbfDKIS3 (ORCPT ); Thu, 11 Apr 2019 04:18:29 -0400 Received: from tyo162.gate.nec.co.jp ([114.179.232.162]:40463 "EHLO tyo162.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726106AbfDKIS3 (ORCPT ); Thu, 11 Apr 2019 04:18:29 -0400 Received: from mailgate01.nec.co.jp ([114.179.233.122]) by tyo162.gate.nec.co.jp (8.15.1/8.15.1) with ESMTPS id x3B8I9fg016167 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 11 Apr 2019 17:18:09 +0900 Received: from mailsv02.nec.co.jp (mailgate-v.nec.co.jp [10.204.236.94]) by mailgate01.nec.co.jp (8.15.1/8.15.1) with ESMTP id x3B8I9gO023088; Thu, 11 Apr 2019 17:18:09 +0900 Received: from mail01b.kamome.nec.co.jp (mail01b.kamome.nec.co.jp [10.25.43.2]) by mailsv02.nec.co.jp (8.15.1/8.15.1) with ESMTP id x3B8I8dX018471; Thu, 11 Apr 2019 17:18:09 +0900 Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.137] [10.38.151.137]) by mail03.kamome.nec.co.jp with ESMTP id BT-MMP-4203940; Thu, 11 Apr 2019 17:16:46 +0900 Received: from BPXM12GP.gisp.nec.co.jp ([10.38.151.204]) by BPXC09GP.gisp.nec.co.jp ([10.38.151.137]) with mapi id 14.03.0319.002; Thu, 11 Apr 2019 17:16:45 +0900 From: Junichi Nomura To: Borislav Petkov CC: Dave Young , Chao Fan , Baoquan He , Kairui Song , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Thread-Topic: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Thread-Index: AQHU78DnNYRsXw6c0kywKGsyat34OKY1dZqAgACP04CAAAH9AA== Date: Thu, 11 Apr 2019 08:16:45 +0000 Message-ID: References: <20190408231011.GA5402@jeru.linux.bs1.fc.nec.co.jp> <20190410171431.GE26580@zn.tnic> <7cbc096d-0548-18b1-a335-8ba114f234a7@ce.jp.nec.com> <20190411080927.GA30080@zn.tnic> In-Reply-To: <20190411080927.GA30080@zn.tnic> Accept-Language: en-US, ja-JP Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.34.125.85] Content-Type: text/plain; charset="utf-8" Content-ID: Content-Transfer-Encoding: base64 MIME-Version: 1.0 X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org T24gNC8xMS8xOSA1OjA5IFBNLCBCb3Jpc2xhdiBQZXRrb3Ygd3JvdGU6DQo+IE9uIFdlZCwgQXBy IDEwLCAyMDE5IGF0IDExOjM0OjUxUE0gKzAwMDAsIEp1bmljaGkgTm9tdXJhIHdyb3RlOg0KPj4g QnV0IGVmaV9nZXRfcnNkcF9hZGRyKCkgbmVlZHMgdG8gY2hlY2sgd2hldGhlciB0aGUga2VybmVs IHdhcw0KPj4ga2V4ZWMgYm9vdGVkIHRvIGF2b2lkIGFjY2Vzc2luZyBpbnZhbGlkIEVGSSB0YWJs ZSBhZGRyZXNzLg0KPj4gZWZpX2dldF9rZXhlY19zZXR1cF9kYXRhX2FkZHIoKSBpcyB0aGUgb25s eSBtZXRob2QgSSBrbm93DQo+PiB0byBjaGVjayBpZiBpdCB3YXMga2V4ZWMtYm9vdGVkLg0KPiAN Cj4gWW91ciB2MyBoYWQgdGhlIHJpZ2h0IGFwcHJvYWNoIC0geW91IGZpcnN0IGNoZWNrIGlmIHlv dSBjYW4gZ2V0IHRoZQ0KPiBhZGRyZXNzIGFzIGEga2V4ZWMtZWQga2VybmVsLiBJZiB5b3UgZG8s IHlvdSB1c2UgdGhhdCBvbmUgYW5kIGNvbnRpbnVlDQo+IHRoZSBub3JtYWwgcGF0aC4NCj4gDQo+ IElmIHlvdSBkb24ndCwgeW91IGZhbGwgYmFjayB0byBlZmlfZ2V0X3JzZHBfYWRkcigpIGFuZCBn ZXQgaXQgZGlyZWN0bHkNCj4gZnJvbSBFRkkuDQo+IA0KPiBBbmQgdGhlbiBjYXJ2ZSBvdXQgdGhl IGZ1bmN0aW9uYWxpdHkgeW91IG5lZWQgdG8gY2FsbCBtdWx0aXBsZSB0aW1lcyBpbg0KPiBoZWxw ZXIgZnVuY3Rpb25zIGxpa2UgX19lZmlfZ2V0X3JzZHBfYWRkcigpLg0KPiANCj4gV2h5IGRvZXNu J3QgdGhhdCB3b3JrIGFueW1vcmU/DQoNCmtleGVjX2dldF9yc2RwX2FkZHIoKSBtaWdodCBmYWls IG9uIGtleGVjLWJvb3RlZCBrZXJuZWwsIGUuZy4gaWYgdGhlDQpzZXR1cF9kYXRhIHdhcyBpbnZh bGlkLiBJbiBzdWNoIGEgY2FzZSwgZmFsbGluZyBiYWNrIHRvIGVmaV9nZXRfcnNkcF9hZGRyKCkN CndpbGwgaGl0IHRoZSBwcm9ibGVtIG9mIGFjY2Vzc2luZyBpbnZhbGlkIHRhYmxlIHBvaW50ZXIg YWdhaW4uDQoNCi0tIA0KSnVuJ2ljaGkgTm9tdXJhLCBORUMgQ29ycG9yYXRpb24gLyBORUMgU29s dXRpb24gSW5ub3ZhdG9ycywgTHRkLg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from tyo162.gate.nec.co.jp ([114.179.232.162]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEUub-0008Go-3p for kexec@lists.infradead.org; Thu, 11 Apr 2019 08:18:22 +0000 From: Junichi Nomura Subject: Re: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Date: Thu, 11 Apr 2019 08:16:45 +0000 Message-ID: References: <20190408231011.GA5402@jeru.linux.bs1.fc.nec.co.jp> <20190410171431.GE26580@zn.tnic> <7cbc096d-0548-18b1-a335-8ba114f234a7@ce.jp.nec.com> <20190411080927.GA30080@zn.tnic> In-Reply-To: <20190411080927.GA30080@zn.tnic> Content-Language: ja-JP Content-ID: MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Borislav Petkov Cc: Chao Fan , Kairui Song , Baoquan He , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Dave Young On 4/11/19 5:09 PM, Borislav Petkov wrote: > On Wed, Apr 10, 2019 at 11:34:51PM +0000, Junichi Nomura wrote: >> But efi_get_rsdp_addr() needs to check whether the kernel was >> kexec booted to avoid accessing invalid EFI table address. >> efi_get_kexec_setup_data_addr() is the only method I know >> to check if it was kexec-booted. > > Your v3 had the right approach - you first check if you can get the > address as a kexec-ed kernel. If you do, you use that one and continue > the normal path. > > If you don't, you fall back to efi_get_rsdp_addr() and get it directly > from EFI. > > And then carve out the functionality you need to call multiple times in > helper functions like __efi_get_rsdp_addr(). > > Why doesn't that work anymore? kexec_get_rsdp_addr() might fail on kexec-booted kernel, e.g. if the setup_data was invalid. In such a case, falling back to efi_get_rsdp_addr() will hit the problem of accessing invalid table pointer again. -- Jun'ichi Nomura, NEC Corporation / NEC Solution Innovators, Ltd. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec