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=-5.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 45F18C433DF for ; Mon, 12 Oct 2020 02:25:54 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E0FF52074A for ; Mon, 12 Oct 2020 02:25:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="0WvPddB4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E0FF52074A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Uo0YAg5M3TMyNGYhDdMmi+PMo0+dwkpT3nfpgxDgrdw=; b=0WvPddB43hwO1ZUJD3sCGeMdT 6hYNlYnvDTdaYf9FWyuDQ2pKM1ZYSH+PC/Scic2zzbINe1/WVzMYzDOyU3WWLvWKISUlbgT0PJE5n NvnvHj5Hj5NIAeoZy96e82UeNRDVOWr02wGfOrzWMhVzFbDuGB9BUs18yXKWLUXvlmCcP/iFfIWXt zvfMyoWj02ZSjMI0D3N+rL62wBEMOXA1pVvEZPF7fEPtSbT7izH0k+BRf7cCfsm9N0+Ksc8BxUADX Lq3mkfGa6ZbhNZKaV+gEoidllk1xE2YarbWUgyWkjbwDyqhKf8QO0dz29M9UIP3weWM2iyT55woMr 1MoEHx8Rw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kRnVb-0001cP-JW; Mon, 12 Oct 2020 02:24:19 +0000 Received: from szxga07-in.huawei.com ([45.249.212.35] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kRnVZ-0001bz-LZ for linux-arm-kernel@lists.infradead.org; Mon, 12 Oct 2020 02:24:18 +0000 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 36A2E6A6EF26DEA1012C; Mon, 12 Oct 2020 10:24:06 +0800 (CST) Received: from [10.67.102.197] (10.67.102.197) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Mon, 12 Oct 2020 10:23:59 +0800 Subject: Re: [PATCH] arm:traps: Don't print stack or raw PC/LR values in backtraces To: Russell King - ARM Linux admin , "Sebastian Andrzej Siewior" References: <20201009075957.110017-1-nixiaoming@huawei.com> <20201009080849.GM1551@shell.armlinux.org.uk> <20201009081820.jargnmck6zfkzegx@linutronix.de> <20201011213238.GN1551@shell.armlinux.org.uk> From: Xiaoming Ni Message-ID: Date: Mon, 12 Oct 2020 10:23:58 +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: <20201011213238.GN1551@shell.armlinux.org.uk> X-Originating-IP: [10.67.102.197] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201011_222417_962528_C3A72F72 X-CRM114-Status: GOOD ( 21.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: wangle6@huawei.com, walken@google.com, amanieu@gmail.com, dima@arista.com, vincent.whitchurch@axis.com, linux-kernel@vger.kernel.org, mingo@kernel.org, ben.dooks@codethink.co.uk, tglx@linutronix.de, viro@zeniv.linux.org.uk, jpoimboe@redhat.com, luohaizheng@huawei.com, akpm@linux-foundation.org, ldufour@linux.ibm.com, will@kernel.org, christian.brauner@ubuntu.com, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020/10/12 5:32, Russell King - ARM Linux admin wrote: > On Fri, Oct 09, 2020 at 10:18:20AM +0200, 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 >>> 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. > > I don't have a problem getting rid of the hex numbers in [< >] > although then I will need to convert the symbol back to an address > using the vmlinux to then calculate its address to then find the > appropriate place in the objdump output - because objdump does > _not_ use the symbol+offset annotation. Yes, I really do look up > the numeric addresses in the objdump output to then read the > disassembly. > > $ objdump -d vmlinux | less > > and then search for the address is the fastest and most convenient > way for me rather than having to deal with some random script. > > Maybe I'm just antequated about how I do my debugging, but this > seems to me to be the most efficient and fastest way. > The loading address of the kernel module is not fixed, so symbol+offset is more useful than a hexadecimal address when the call stack contains kernel module symbols. Delete the PC/LR address and retain the sysbol+offset. The kernel can still be debugged. Thanks Xiaoming Ni _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel