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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 368F0C00449 for ; Mon, 8 Oct 2018 08:47:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8D0520878 for ; Mon, 8 Oct 2018 08:47:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E8D0520878 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726960AbeJHP6Y (ORCPT ); Mon, 8 Oct 2018 11:58:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48471 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726013AbeJHP6Y (ORCPT ); Mon, 8 Oct 2018 11:58:24 -0400 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.25]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 75F663001BDE; Mon, 8 Oct 2018 08:47:47 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-85.pek2.redhat.com [10.72.12.85]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B032620165F4; Mon, 8 Oct 2018 08:47:38 +0000 (UTC) Subject: Re: [tip:x86/mm] kdump, proc/vmcore: Enable kdumping encrypted memory with SME enabled To: Borislav Petkov Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de, hpa@zytor.com, linux-tip-commits@vger.kernel.org References: <21eab36e-d113-cf88-e497-7dd620981544@redhat.com> <20181007084742.GA30797@zn.tnic> <58270f3f-f17c-8996-09cd-6da3481beb40@redhat.com> <20181008053714.GA6490@zn.tnic> <710b9d95-2f70-eadf-c4a1-c3dc80ee4ebb@redhat.com> <20181008080013.GB6490@zn.tnic> From: lijiang Message-ID: <8147597a-f8e0-7f1a-bd2b-e914b18c5c74@redhat.com> Date: Mon, 8 Oct 2018 16:47:34 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181008080013.GB6490@zn.tnic> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.25 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Mon, 08 Oct 2018 08:47:47 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2018年10月08日 16:00, Borislav Petkov 写道: > On Mon, Oct 08, 2018 at 03:11:56PM +0800, lijiang wrote: >> I used this ".config" to compile kernel in the attachment, and got a compile error. >> Would you like to have a try? >> >> [root@hp-dl385g10-03 linux]# make ARCH=i386 -j32 >> ...... >> LD vmlinux.o >> MODPOST vmlinux.o >> fs/proc/vmcore.o：In function ‘read_from_oldmem’： >> /home/linux/fs/proc/vmcore.c:127：undefined reference to ‘copy_oldmem_page_encrypted’ >> make: *** [vmlinux] error 1 > > Thanks, that triggered here. Ok, I guess something like this, to avoid > the ugly ifdeffery: > > --- > diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c > index 33ee47670b99..8696800f2eea 100644 > --- a/arch/x86/kernel/crash_dump_32.c > +++ b/arch/x86/kernel/crash_dump_32.c > @@ -80,6 +80,16 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, > return csize; > } > > +/* > + * 32-bit parrot version to avoid build errors. > + */ > +ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, > + unsigned long offset, int userbuf) > +{ > + WARN_ON_ONCE(1); > + return copy_oldmem_page(pfn, buf, csize, offset, userbuf); > +} > + It looks like a good way to avoid the 'ifdefined', and it's also good enough for i386. But for other architectures, such as POWERPC/ARM..., we will also have to add the same function for every architecture. Otherwise, i guess that they also have a same compile error on other architectures. Sometimes, it's hard to make a choice. Regards, Lianbo > static int __init kdump_buf_page_init(void) > { > int ret = 0; > > >