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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 1D3CFC433E0 for ; Mon, 1 Jun 2020 18:51:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E063A206C3 for ; Mon, 1 Jun 2020 18:51:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591037483; bh=jCQsJ5sv/3f8Qy4HXb7QH7TnNvsklmAK7y4wi41MlAU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jBfnM9ck6PyIfeppaH2US9z418nm9istq9UZsv60UtasU8olMgtltYYg4tO7CXDEc PMYplp88+l6C623inpfATj6GYqsV+3QVuGRAuKYU9lta37EuUdz2qv0BPC3o3nR047 KI6fn03h3bzXCKO9IAoaHDST4p29vBpVJnrFo1QA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730303AbgFASvW (ORCPT ); Mon, 1 Jun 2020 14:51:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:50052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729806AbgFASFD (ORCPT ); Mon, 1 Jun 2020 14:05:03 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 649722077D; Mon, 1 Jun 2020 18:05:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591034702; bh=jCQsJ5sv/3f8Qy4HXb7QH7TnNvsklmAK7y4wi41MlAU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z2HXhe4F6t32mzRIrz+UuSmrNFd5KW0q6fVoTgV9XvzJY4YZsSF8iO8qsYBpRi7hy XZpMWl2pSke3SnW63zLc8NvohA8vImGGT+ZhKR6WS1pUVFXs+PMbeD1fneL8iMFyXQ W6E88C7UG1uBK68qcHTTp3ouarjeyhbfUyzzyO4Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Helge Deller Subject: [PATCH 4.19 69/95] parisc: Fix kernel panic in mem_init() Date: Mon, 1 Jun 2020 19:54:09 +0200 Message-Id: <20200601174031.735191678@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200601174020.759151073@linuxfoundation.org> References: <20200601174020.759151073@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Helge Deller commit bf71bc16e02162388808949b179d59d0b571b965 upstream. The Debian kernel v5.6 triggers this kernel panic: Kernel panic - not syncing: Bad Address (null pointer deref?) Bad Address (null pointer deref?): Code=26 (Data memory access rights trap) at addr 0000000000000000 CPU: 0 PID: 0 Comm: swapper Not tainted 5.6.0-2-parisc64 #1 Debian 5.6.14-1 IAOQ[0]: mem_init+0xb0/0x150 IAOQ[1]: mem_init+0xb4/0x150 RP(r2): start_kernel+0x6c8/0x1190 Backtrace: [<0000000040101ab4>] start_kernel+0x6c8/0x1190 [<0000000040108574>] start_parisc+0x158/0x1b8 on a HP-PARISC rp3440 machine with this memory layout: Memory Ranges: 0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB 1) Start 0x0000004040000000 End 0x00000040ffdfffff Size 3070 MB Fix the crash by avoiding virt_to_page() and similar functions in mem_init() until the memory zones have been fully set up. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v5.0+ Signed-off-by: Greg Kroah-Hartman --- arch/parisc/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/parisc/mm/init.c +++ b/arch/parisc/mm/init.c @@ -607,7 +607,7 @@ void __init mem_init(void) > BITS_PER_LONG); high_memory = __va((max_pfn << PAGE_SHIFT)); - set_max_mapnr(page_to_pfn(virt_to_page(high_memory - 1)) + 1); + set_max_mapnr(max_low_pfn); free_all_bootmem(); #ifdef CONFIG_PA11