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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 60EA3C4BA14 for ; Wed, 26 Feb 2020 15:14:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CD4A24680 for ; Wed, 26 Feb 2020 15:14:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727936AbgBZPOf (ORCPT ); Wed, 26 Feb 2020 10:14:35 -0500 Received: from foss.arm.com ([217.140.110.172]:37256 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726148AbgBZPOe (ORCPT ); Wed, 26 Feb 2020 10:14:34 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 260B430E; Wed, 26 Feb 2020 07:14:34 -0800 (PST) Received: from [10.1.196.105] (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 530F33F819; Wed, 26 Feb 2020 07:14:33 -0800 (PST) Subject: Re: [PATCH] trace: ras: print the raw data of arm processor error info To: Xie XiuQi Cc: Borislav Petkov , tony.luck@intel.com, linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20191214121109.8349-1-xiexiuqi@huawei.com> <20200109114603.GC5603@zn.tnic> <3086a22d-6d66-df74-5878-60a8fc0f1499@huawei.com> From: James Morse Message-ID: Date: Wed, 26 Feb 2020 15:14:30 +0000 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <3086a22d-6d66-df74-5878-60a8fc0f1499@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Xie, On 13/01/2020 14:10, Xie XiuQi wrote: > What do you think of this patch? > > On 2020/1/9 19:46, Borislav Petkov wrote: >>> ); >>> >>> /* What patch?! (digs in the headers) https://lore.kernel.org/linux-edac/20191214121109.8349-1-xiexiuqi@huawei.com/ >>> -- >> That's for ARM folks to decide whether they wanna shuffle raw error >> records into userspace like that. CCed. Hmm, this dumps more of 'CPER_SEC_PROC_ARM' to user-space. But not all of it ... (ugh, this is the thing with three variable length fields in it!) I would like to be able to parse these in the kernel eventually, but that doesn't matter right now. I agree privileged user-space should be able to collect all the CPER for some tool to analyse it. (what else would we do with 'vendor specific error info'?). I'm not totally convinced tracepoints are the right thing for big blobs of data like this, but its what we're using today. I'll show my ignorance about trace points: How does rasdaemon react to you expanding the trace point like this? I recall they are self-describing, if user-space doesn't hard code the layout... You export what may be kernel pointers with the virtual fault address. Is there any way an unprivileged user can get hold of these? (its somewhat pointless as user-space can't know what that pointer means) Thanks, James