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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 3787DC2BAEE for ; Tue, 24 Mar 2020 13:25:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D17120870 for ; Tue, 24 Mar 2020 13:25:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585056346; bh=DP409ajFviKMx013wmdRjhrUduVC9VtoO0DR9ctjHH4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R2QDriuIfQbEcCU8lK0QeQacG4Ga/HWvdqkANAid2aN2a6J2bhhvGdCC/e8RBIa+8 AH9X6qDa76kjtXnWzDEUhG2jxbkO0SeQ0kUSZfcIAE2ODNrPam9UsBkrfjTiTwRf+B 54hBeb/0WOwBHLeu0WdKjgvxPV4BuEmPWgUNqxSM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728106AbgCXNZk (ORCPT ); Tue, 24 Mar 2020 09:25:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:50056 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727935AbgCXNZj (ORCPT ); Tue, 24 Mar 2020 09:25:39 -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 89F10208CA; Tue, 24 Mar 2020 13:25:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585056339; bh=DP409ajFviKMx013wmdRjhrUduVC9VtoO0DR9ctjHH4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pVqYKUWgE0C6hgE0Qi24er1hkazT9kc0k6FpRZ8GxkWEN9FWZvp61kWJRhNEnxDtP 7eSk2fCZbd27rkK4YYICVX87AnEO8xOCsls9CNYMo4dhzBOFYy/CvKGUes3C7Sc18t EbznLCUm+CkMZCj9BU0TsOJ7KwCrQQ2koqokAjxc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Baoquan He , Andrew Morton , Pankaj Gupta , David Hildenbrand , Michal Hocko , Wei Yang , Oscar Salvador , Mike Rapoport , Linus Torvalds Subject: [PATCH 5.5 095/119] mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case Date: Tue, 24 Mar 2020 14:11:20 +0100 Message-Id: <20200324130817.665452833@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200324130808.041360967@linuxfoundation.org> References: <20200324130808.041360967@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Baoquan He commit d41e2f3bd54699f85b3d6f45abd09fa24a222cb9 upstream. In section_deactivate(), pfn_to_page() doesn't work any more after ms->section_mem_map is resetting to NULL in SPARSEMEM|!VMEMMAP case. It causes a hot remove failure: kernel BUG at mm/page_alloc.c:4806! invalid opcode: 0000 [#1] SMP PTI CPU: 3 PID: 8 Comm: kworker/u16:0 Tainted: G W 5.5.0-next-20200205+ #340 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:free_pages+0x85/0xa0 Call Trace: __remove_pages+0x99/0xc0 arch_remove_memory+0x23/0x4d try_remove_memory+0xc8/0x130 __remove_memory+0xa/0x11 acpi_memory_device_remove+0x72/0x100 acpi_bus_trim+0x55/0x90 acpi_device_hotplug+0x2eb/0x3d0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x1a7/0x370 worker_thread+0x30/0x380 kthread+0x112/0x130 ret_from_fork+0x35/0x40 Let's move the ->section_mem_map resetting after depopulate_section_memmap() to fix it. [akpm@linux-foundation.org: remove unneeded initialization, per David] Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") Signed-off-by: Baoquan He Signed-off-by: Andrew Morton Reviewed-by: Pankaj Gupta Reviewed-by: David Hildenbrand Acked-by: Michal Hocko Cc: Wei Yang Cc: Oscar Salvador Cc: Mike Rapoport Cc: Link: http://lkml.kernel.org/r/20200307084229.28251-2-bhe@redhat.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/sparse.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/mm/sparse.c +++ b/mm/sparse.c @@ -744,6 +744,7 @@ static void section_deactivate(unsigned struct mem_section *ms = __pfn_to_section(pfn); bool section_is_early = early_section(ms); struct page *memmap = NULL; + bool empty; unsigned long *subsection_map = ms->usage ? &ms->usage->subsection_map[0] : NULL; @@ -774,7 +775,8 @@ static void section_deactivate(unsigned * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified */ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); - if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) { + empty = bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION); + if (empty) { unsigned long section_nr = pfn_to_section_nr(pfn); /* @@ -789,13 +791,15 @@ static void section_deactivate(unsigned ms->usage = NULL; } memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - ms->section_mem_map = (unsigned long)NULL; } if (section_is_early && memmap) free_map_bootmem(memmap); else depopulate_section_memmap(pfn, nr_pages, altmap); + + if (empty) + ms->section_mem_map = (unsigned long)NULL; } static struct page * __meminit section_activate(int nid, unsigned long pfn,