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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 625D0C10F13 for ; Thu, 11 Apr 2019 09:21:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28F3A217D4 for ; Thu, 11 Apr 2019 09:21:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="ixT9WUjK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726930AbfDKJVe (ORCPT ); Thu, 11 Apr 2019 05:21:34 -0400 Received: from mail.skyhub.de ([5.9.137.197]:38326 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbfDKJVd (ORCPT ); Thu, 11 Apr 2019 05:21:33 -0400 Received: from [10.119.185.175] (x2f7f9af.dyn.telefonica.de [2.247.249.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id EEC991EC01B6; Thu, 11 Apr 2019 11:21:29 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1554974490; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ArcHdxASerKPWBHzWz02Yr3opgXM61uRU/36Wc0nFAw=; b=ixT9WUjKH0lmoUFef7fiK6hzXaoNvNWejhhGm7xfF7LWG0kQo5E8VkdCFKC3HjKBpTcHwK qdQiHNcX3ZMKanLpkkeLc2VDO9V77snHlvZHOGUy6DjoUwoCrM4EyysMRnZGHCyjIAPkGV KALBz1jW2TqOO6OjDQvewlXGVcL3E6k= Date: Thu, 11 Apr 2019 11:21:28 +0200 User-Agent: K-9 Mail for Android In-Reply-To: <2946b5e3-90bf-d617-16a4-d2225b490b5d@ce.jp.nec.com> 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> <20190411083738.GC30080@zn.tnic> <2946b5e3-90bf-d617-16a4-d2225b490b5d@ce.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH v4] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel To: Junichi Nomura CC: Dave Young , Chao Fan , Baoquan He , Kairui Song , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" From: Boris Petkov Message-ID: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On April 11, 2019 11:13:03 AM GMT+02:00, Junichi Nomura wrote: >On 4/11/19 5:37 PM, Borislav Petkov wrote: >> On Thu, Apr 11, 2019 at 08:16:45AM +0000, Junichi Nomura wrote: >>> kexec_get_rsdp_addr() might fail on kexec-booted kernel, e=2Eg=2E if t= he >>> setup_data was invalid=2E In such a case, falling back to >efi_get_rsdp_addr() >>> will hit the problem of accessing invalid table pointer again=2E >>=20 >> Then you need to do this: >>=20 >> if (kexeced kernel) { >> addr =3D kexec_get_rsdp_addr(); >> if (!addr) { >> /* cannot get address */ >> return -1; >> } >>=20 >> return addr; >> } >>=20 >> and the calling function get_rsdp_addr() must check the return value >and >> if it is not 0, return immediately=2E > >Do you mean making get_rsdp_addr() like this? Does that look like what I've typed above? --=20 Sent from a small device: formatting sux and brevity is inevitable=2E