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=-5.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 01105ECE560 for ; Sun, 16 Sep 2018 22:18:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78F132087E for ; Sun, 16 Sep 2018 22:18:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=tobin.cc header.i=@tobin.cc header.b="ppEzPMT/"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="n2CATKyv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78F132087E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=tobin.cc Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728455AbeIQDmy (ORCPT ); Sun, 16 Sep 2018 23:42:54 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:57019 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728169AbeIQDmy (ORCPT ); Sun, 16 Sep 2018 23:42:54 -0400 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id A2D2C22158; Sun, 16 Sep 2018 18:18:27 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute5.internal (MEProxy); Sun, 16 Sep 2018 18:18:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tobin.cc; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=kWgdmMZ5Lp6bGRs3o5NLuNYCnJi600szaF2YGpx0US4=; b=ppEzPMT/ pkpD1x23q0BgPENlcf7rlFOMQnfYZLUIZHeQMOj6YkDGnUZGVNio0/uDNCW8OEC+ vOPXG6xCIG6DhPPnT+Gik4ZE0lrg/vjY4ox3JVX7l85OigIJ5/2ZEh1egRBi519K S4mu/gN7COoxSG9hja10u0kW2hSrWMdnSJ8sTyuSoPW9cXZnj6sBOKIFB8ba3cqH Xy12QYxmvwKev84uREOgL8s4uNvq9U0t9UWIWBqIVxj7REJFxAeTLUBOLWAjcYZE DSaALQwDFCPhtIGHRTtk/WMz3I9Fs3CAOz5eIkwWeb0vj2cwbQeBHOx4jRHljEfZ AFZ6dD5RPjqjjA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=fm3; bh=kWgdmMZ5Lp6bGRs3o5NLuNYCnJi60 0szaF2YGpx0US4=; b=n2CATKyv1xMQMNVddDFUJfQaSc7mj3HsozZP9wV/3dltK saM9xOTbLVdiDXHfk3vWqoYyIkMDdDbv97zqHgQnAe0NOQAnfH4Q6fISP/wTXO8A S/cNzGdP1c494BzKV4KdOXfW+IA8oaQHrZOFGyPn47gxtSOW3op/Vhov4ao/2w4C y/SafwNDNm/D6REVhKMmEofYwC+CC5E0XpJX/+aX6KALqIiqrgTVedZc6TTvxyfA S1V891+yjNlyWF2go0j7Uk7Ykx4YgdrX8bzqR3G66xUolixKdBjQM93etOpEgCIZ G9kgqwTt6teCga+J4P/OwdiZKnuQkeL+cfqC2X/bA== X-ME-Proxy: X-ME-Sender: Received: from localhost (ppp121-44-228-8.bras2.syd2.internode.on.net [121.44.228.8]) by mail.messagingengine.com (Postfix) with ESMTPA id 6F57C102D6; Sun, 16 Sep 2018 18:18:25 -0400 (EDT) Date: Mon, 17 Sep 2018 08:18:22 +1000 From: "Tobin C. Harding" To: Daniel Thompson Cc: Christophe Leroy , Jason Wessel , Michael Ellerman , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kgdb-bugreport@lists.sourceforge.net, stable@vger.kernel.org Subject: Re: [PATCH] kdb: use correct pointer when 'btc' calls 'btt' Message-ID: <20180916221822.GO11198@eros> References: <20180916190610.vzqxwps7zqy2zc6o@holly.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180916190610.vzqxwps7zqy2zc6o@holly.lan> X-Mailer: Mutt 1.9.4 (2018-02-28) User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 16, 2018 at 12:06:10PM -0700, Daniel Thompson wrote: > On Fri, Sep 14, 2018 at 12:35:44PM +0000, Christophe Leroy wrote: > > On a powerpc 8xx, 'btc' fails as follows: > > > > Entering kdb (current=0x(ptrval), pid 282) due to Keyboard Entry > > kdb> btc > > btc: cpu status: Currently on cpu 0 > > Available cpus: 0 > > kdb_getarea: Bad address 0x0 > > > > when booting the kernel with 'debug_boot_weak_hash', it fails as well > > > > Entering kdb (current=0xba99ad80, pid 284) due to Keyboard Entry > > kdb> btc > > btc: cpu status: Currently on cpu 0 > > Available cpus: 0 > > kdb_getarea: Bad address 0xba99ad80 > > > > On other platforms, Oopses have been observed too, see > > https://github.com/linuxppc/linux/issues/139 > > > > This is due to btc calling 'btt' with %p pointer as an argument. > > > > This patch replaces %p by %px to get the real pointer value as > > expected by 'btt' > > > > Signed-off-by: Christophe Leroy > > Cc: # 4.15+ > > Would a Fixes: be better here? > Fixes: ad67b74d2469d9b82 ("printk: hash addresses printed with %p") > > No blame attached to Tobin, but the fixes makes it super clear what :) > changed and why this breaks kdb (which was not explicitly called out > the patch description). > > > Daniel.