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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 76168C433DF for ; Fri, 9 Oct 2020 08:58:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22E0722282 for ; Fri, 9 Oct 2020 08:58:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732988AbgJII65 (ORCPT ); Fri, 9 Oct 2020 04:58:57 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:35744 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732507AbgJII64 (ORCPT ); Fri, 9 Oct 2020 04:58:56 -0400 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 9FB24A3E691660E77F98; Fri, 9 Oct 2020 16:58:55 +0800 (CST) Received: from [10.67.102.197] (10.67.102.197) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.487.0; Fri, 9 Oct 2020 16:58:48 +0800 Subject: Re: [PATCH] arm:traps: Don't print stack or raw PC/LR values in backtraces To: Sebastian Andrzej Siewior , "Russell King - ARM Linux admin" CC: , , , , , , , , , , , , , , , , References: <20201009075957.110017-1-nixiaoming@huawei.com> <20201009080849.GM1551@shell.armlinux.org.uk> <20201009081820.jargnmck6zfkzegx@linutronix.de> From: Xiaoming Ni Message-ID: Date: Fri, 9 Oct 2020 16:58:42 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.0.1 MIME-Version: 1.0 In-Reply-To: <20201009081820.jargnmck6zfkzegx@linutronix.de> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.102.197] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/10/9 16:18, Sebastian Andrzej Siewior wrote: > On 2020-10-09 09:08:50 [+0100], Russell King - ARM Linux admin wrote: >> I am really not happy about this - it hurts at least my ability to >> debug the kernel when people post oopses to the mailing list. If In the reset scenario, dump_mem is retained: @@ -125,6 +118,9 @@ static void dump_mem(const char *lvl, const char *str, unsigned long bottom, mm_segment_t fs; int i; + /* Do not print virtual addresses in non-reset scenarios */ + if (!panic_on_oops) + return; >> people wish to make the kernel harder to debug, and are prepared >> to be told "your kernel is undebuggable" then this patch is fine. > > I haven't look at the patch but don't they keep/add the representation: > PC: symbol+offset/size > LR: symbol+offset/size > > ? This is needed at very least as a replacement for the missing address. Yes, only %08lx was deleted, but %ps is still retained. - printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", - loglvl, where, (void *)where, from, (void *)from); + printk("%s (%ps) from (%pS)\n", + loglvl, (void *)where, (void *)from); Thanks Xiaoming Ni