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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 803D8C433EF for ; Mon, 18 Jun 2018 13:59:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 261552086A for ; Mon, 18 Jun 2018 13:59:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 261552086A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-m68k.org 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 S934594AbeFRN7r (ORCPT ); Mon, 18 Jun 2018 09:59:47 -0400 Received: from icp-osb-irony-out7.external.iinet.net.au ([203.59.1.107]:29238 "EHLO icp-osb-irony-out7.external.iinet.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934030AbeFRN7p (ORCPT ); Mon, 18 Jun 2018 09:59:45 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A2DHAADsuSdb/4D0zssNThoBAQEBAQIBA?= =?us-ascii?q?QEBCAEBAQGEKoEUE4N5likIIZRxgXgqhE0Cgnw2FgECAQEBAQEBAoEJhTUBAQE?= =?us-ascii?q?DIxVBEAsNCwICJgICVwYNBgIBAYMhAoFyHKgLbYIcGoRBg2iBYwWBC4lcgQ8kD?= =?us-ascii?q?IJcgnyEeoJVApkWCAGFfIkHiB6FI4oSiQMHgXwzGggoCIJ+H4ICF4hZhVBdkFE?= =?us-ascii?q?BAQ?= X-IPAS-Result: =?us-ascii?q?A2DHAADsuSdb/4D0zssNThoBAQEBAQIBAQEBCAEBAQGEKoE?= =?us-ascii?q?UE4N5likIIZRxgXgqhE0Cgnw2FgECAQEBAQEBAoEJhTUBAQEDIxVBEAsNCwICJ?= =?us-ascii?q?gICVwYNBgIBAYMhAoFyHKgLbYIcGoRBg2iBYwWBC4lcgQ8kDIJcgnyEeoJVApk?= =?us-ascii?q?WCAGFfIkHiB6FI4oSiQMHgXwzGggoCIJ+H4ICF4hZhVBdkFEBAQ?= X-IronPort-AV: E=Sophos;i="5.51,239,1526313600"; d="scan'208";a="90129292" Received: from unknown (HELO [192.168.0.106]) ([203.206.244.128]) by icp-osb-irony-out7.iinet.net.au with ESMTP; 18 Jun 2018 21:59:41 +0800 Subject: Re: [PATCH] m68k: fix "bad page state" oops on ColdFire boot To: Geert Uytterhoeven Cc: Matthew Wilcox , Linux/m68k , Linux Kernel Mailing List References: <20180618060426.24497-1-gerg@linux-m68k.org> From: Greg Ungerer Message-ID: <8cd9643d-0855-ac30-41cb-7de24314da00@linux-m68k.org> Date: Mon, 18 Jun 2018 23:59:40 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Geert, On 18/06/18 16:58, Geert Uytterhoeven wrote: > Hi Greg, > > On Mon, Jun 18, 2018 at 8:06 AM Greg Ungerer wrote: >> Booting a ColdFire m68k core with MMU enabled causes a "bad page state" >> oops since commit 1d40a5ea01d5 ("mm: mark pages in use for page tables"): >> >> BUG: Bad page state in process sh pfn:01ce2 >> page:004fefc8 count:0 mapcount:-1024 mapping:00000000 index:0x0 >> flags: 0x0() >> raw: 00000000 00000000 00000000 fffffbff 00000000 00000100 00000200 00000000 >> raw: 039c4000 >> page dumped because: nonzero mapcount >> Modules linked in: >> CPU: 0 PID: 22 Comm: sh Not tainted 4.17.0-07461-g1d40a5ea01d5 #13 >> >> Fix by calling pgtable_page_dtor() in our __pte_free_tlb() code path, >> so that the PG_table flag is cleared before we free the pte page. >> >> Signed-off-by: Greg Ungerer >> CC: Matthew Wilcox >> --- >> arch/m68k/include/asm/mcf_pgalloc.h | 1 + >> 1 file changed, 1 insertion(+) >> >> Matthew: I came across this thread at https://lkml.org/lkml/2018/6/17/163 >> about a similar problem with openrisc. Based on that I came up >> with this fix for m68k/ColdFire. Fixes the issue for me. >> >> diff --git a/arch/m68k/include/asm/mcf_pgalloc.h b/arch/m68k/include/asm/mcf_pgalloc.h >> index 8b707c249026..8c441eb57b80 100644 >> --- a/arch/m68k/include/asm/mcf_pgalloc.h >> +++ b/arch/m68k/include/asm/mcf_pgalloc.h >> @@ -44,6 +44,7 @@ extern inline pmd_t *pmd_alloc_kernel(pgd_t *pgd, unsigned long address) >> static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t page, >> unsigned long address) >> { >> + pgtable_page_dtor(page); >> __free_page(page); >> } > > Do you need a call to pgtable_page_dtor() in pte_free(), too? > On x86 (and motorola_pgalloc.h and sun3_pgalloc.h FWIW), both functions > call pgtable_page_dtor(). I am thinking yes, looking at those other examples. Regards Greg