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=-8.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 5DBDBC433DF for ; Fri, 9 Oct 2020 08:09:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E309D21789 for ; Fri, 9 Oct 2020 08:09:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="ve8cCGYk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732685AbgJIIJX (ORCPT ); Fri, 9 Oct 2020 04:09:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732464AbgJIIJW (ORCPT ); Fri, 9 Oct 2020 04:09:22 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9276C0613D2 for ; Fri, 9 Oct 2020 01:09:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=kEaJrhB49jY9ylGi747PC2d3zrqsG3GTNHlV2nr1xSo=; b=ve8cCGYklFqGLKtG5GkwJljNv a3hbBRQkLbNvUxGBvRLjfgm8UYZTG64wt/m0NgpJL8GTh+fmKL5e1YuiE6RUMJY5IHvRBitFMV07P VuNeBlLoz8yJ1U/X7/zi8hIcCw40aQddMK62i2TCOL5Zfzf9AZm9SaKhMGUJ/L4wa/s+hpbT/geGr 6znwoJ9jU6CJGyPnlmntqiuNeh9en5i/iQG4MSe6taT2anM9hRQKfv7pj9V8W5032KYMHT69wpH8d xZYErn38o1U5L5szCdPa0oEpo3tZl2PwQz13EyumuR3WeGrImdHMt1pDLD9Xu8UkpPKcV+audPxof qWK9gP5hA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:43798) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kQnSR-0007iv-PC; Fri, 09 Oct 2020 09:08:55 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1kQnSM-0002VN-ES; Fri, 09 Oct 2020 09:08:50 +0100 Date: Fri, 9 Oct 2020 09:08:50 +0100 From: Russell King - ARM Linux admin To: Xiaoming Ni Cc: dima@arista.com, will@kernel.org, jpoimboe@redhat.com, akpm@linux-foundation.org, christian.brauner@ubuntu.com, viro@zeniv.linux.org.uk, ldufour@linux.ibm.com, amanieu@gmail.com, walken@google.com, ben.dooks@codethink.co.uk, tglx@linutronix.de, bigeasy@linutronix.de, mingo@kernel.org, vincent.whitchurch@axis.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, wangle6@huawei.com, luohaizheng@huawei.com Subject: Re: [PATCH] arm:traps: Don't print stack or raw PC/LR values in backtraces Message-ID: <20201009080849.GM1551@shell.armlinux.org.uk> References: <20201009075957.110017-1-nixiaoming@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201009075957.110017-1-nixiaoming@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: Russell King - ARM Linux admin Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 09, 2020 at 03:59:57PM +0800, Xiaoming Ni wrote: > Printing raw pointer values in backtraces has potential security > implications and are of questionable value anyway. > > This patch follows x86 and arm64's lead and removes the "Exception stack:" > dump from kernel backtraces: > commit a25ffd3a6302a6 ("arm64: traps: Don't print stack or raw > PC/LR values in backtraces") > commit 0ee1dd9f5e7eae ("x86/dumpstack: Remove raw stack dump") > commit bb5e5ce545f203 ("x86/dumpstack: Remove kernel text > addresses from stack dump") > > Signed-off-by: Xiaoming Ni 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. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!