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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 C8A92C2BA83 for ; Mon, 10 Feb 2020 00:50:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D94220715 for ; Mon, 10 Feb 2020 00:50:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726942AbgBJAun (ORCPT ); Sun, 9 Feb 2020 19:50:43 -0500 Received: from mga03.intel.com ([134.134.136.65]:36888 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbgBJAun (ORCPT ); Sun, 9 Feb 2020 19:50:43 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Feb 2020 16:50:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,423,1574150400"; d="scan'208";a="405427008" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga005.jf.intel.com with ESMTP; 09 Feb 2020 16:50:41 -0800 From: Wei Yang To: akpm@linux-foundation.org, osalvador@suse.de, dan.j.williams@intel.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wei Yang , David Hildenbrand , Baoquan He Subject: [Patch v2] mm/sparsemem: get address to page struct instead of address to pfn Date: Mon, 10 Feb 2020 08:50:48 +0800 Message-Id: <20200210005048.10437-1-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org memmap should be the address to page struct instead of address to pfn. As mentioned by David, if system memory and devmem sit within a section, the mismatch address would lead kdump to dump unexpected memory. Since sub-section only works for SPARSEMEM_VMEMMAP, pfn_to_page() is valid to get the page struct address at this point. Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") Signed-off-by: Wei Yang CC: Dan Williams CC: David Hildenbrand CC: Baoquan He --- v2: * adjust comment to mention the mismatch data would affect kdump --- mm/sparse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/sparse.c b/mm/sparse.c index 586d85662978..4862ec2cfbc0 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -887,7 +887,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, /* Align memmap to section boundary in the subsection case */ if (section_nr_to_pfn(section_nr) != start_pfn) - memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr)); + memmap = pfn_to_page(section_nr_to_pfn(section_nr)); sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); return 0; -- 2.17.1