From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755458AbcASNqW (ORCPT ); Tue, 19 Jan 2016 08:46:22 -0500 Received: from mail-pa0-f46.google.com ([209.85.220.46]:35679 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754766AbcASNqM (ORCPT ); Tue, 19 Jan 2016 08:46:12 -0500 Message-ID: <569E3E18.2040003@linaro.org> Date: Tue, 19 Jan 2016 21:46:00 +0800 From: Shannon Zhao User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Mark Rutland CC: Stefano Stabellini , Shannon Zhao , linux-arm-kernel@lists.infradead.org, ard.biesheuvel@linaro.org, stefano.stabellini@citrix.com, david.vrabel@citrix.com, devicetree@vger.kernel.org, linux-efi@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, xen-devel@lists.xen.org, julien.grall@citrix.com, peter.huangpeng@huawei.com, matt@codeblueprint.co.uk Subject: Re: [Xen-devel] [PATCH v2 14/16] Xen: EFI: Parse DT parameters for Xen specific UEFI References: <1452840929-19612-1-git-send-email-zhaoshenglong@huawei.com> <1452840929-19612-15-git-send-email-zhaoshenglong@huawei.com> <569E37C9.6040700@linaro.org> <20160119134318.GB26545@leverpostej> In-Reply-To: <20160119134318.GB26545@leverpostej> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016/1/19 21:43, Mark Rutland wrote: > On Tue, Jan 19, 2016 at 09:19:05PM +0800, Shannon Zhao wrote: >> >> >> On 2016/1/18 23:41, Stefano Stabellini wrote: >>> CC'ing Matt Fleming >>> >>> On Fri, 15 Jan 2016, Shannon Zhao wrote: >>>> From: Shannon Zhao >>>> @@ -520,15 +531,28 @@ static int __init fdt_find_uefi_params(unsigned long node, const char *uname, >>>> int depth, void *data) >>>> { >>>> struct param_info *info = data; >>>> + struct params *dt_params; >>>> + unsigned int size; >>>> const void *prop; >>>> void *dest; >>>> u64 val; >>>> int i, len; >>>> >>>> - if (depth != 1 || strcmp(uname, "chosen") != 0) >>>> - return 0; >>>> + if (efi_enabled(EFI_PARAVIRT)) { >>>> + if (depth != 2 || strcmp(uname, "uefi") != 0) >>> >>> You are already introducing this check in the previous patch when >>> setting EFI_PARAVIRT, why do this again now? But if we need to do this >>> check again, then, like Mark suggested, it should be done against the >>> full path. >>> >> This check just wants to confirm that the current node is the "uefi" >> node and we can parse it with xen_fdt_params now. > > There is no single "uefi" node as many nodes can share that name. There > is at most a single, /hypervisor/uefi node, as that is qualified by a > full path. > Sure, I will check it by full path. > Checking the leaf node name, as above, is insufficient. For example, the > below will be accepted: > > * /chosen/uefi > * /foo/uefi > * /not-a-hypervisor/uefi > > Any of these could exist in addition to a /hypervisor/uefi node, and > could appear ealier or later in the DTB. > > There may be reasons to add such nodes in future, and regardless we > should not read properties from an invalid/wrong node. > > Thanks, > Mark. > -- Shannon