From patchwork Tue Jan 28 09:50:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 232766 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=-4.4 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_DBL_ABUSE_MALW autolearn=no 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 CD191C3F68F for ; Tue, 28 Jan 2020 09:51:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9921C214D8 for ; Tue, 28 Jan 2020 09:51:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BhWefdQC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726002AbgA1Jvy (ORCPT ); Tue, 28 Jan 2020 04:51:54 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:55927 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725901AbgA1Jvy (ORCPT ); Tue, 28 Jan 2020 04:51:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580205112; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B7MB7oUPUx8XhDuAF7Akvb1jkOAALGY6qLQV69vnf48=; b=BhWefdQCNktLHfv8sxBHTRWm9D4ShXZNiBxIwpWdRL6Pu7o4XTJZxC0XstUksNz6MWHJ2E 4QvFuLNwjA8Agze/+BqC1rLhJiGZSFOPhtQvgOU5w9iJSAq4cPmC8wT1mVBROBcuG+2GsZ 3iTVbKGznkBTHykj+6XeWz/fjiemjuo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-22-Y6JgBZm6MNKFx3yGnqpUkA-1; Tue, 28 Jan 2020 04:51:44 -0500 X-MC-Unique: Y6JgBZm6MNKFx3yGnqpUkA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 43EEA8010DA; Tue, 28 Jan 2020 09:51:43 +0000 (UTC) Received: from t480s.redhat.com (ovpn-116-207.ams2.redhat.com [10.36.116.207]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1132160BE0; Tue, 28 Jan 2020 09:51:40 +0000 (UTC) From: David Hildenbrand To: stable@vger.kernel.org Cc: linux-mm@kvack.org, Michal Hocko , Greg Kroah-Hartman , Andrew Morton , "Aneesh Kumar K . V" , Baoquan He , Dan Williams , Oscar Salvador , Wei Yang , David Hildenbrand Subject: [PATCH for 4.19-stable v3 22/24] mm/memunmap: don't access uninitialized memmap in memunmap_pages() Date: Tue, 28 Jan 2020 10:50:19 +0100 Message-Id: <20200128095021.8076-23-david@redhat.com> In-Reply-To: <20200128095021.8076-1-david@redhat.com> References: <20200128095021.8076-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: "Aneesh Kumar K.V" commit 77e080e7680e1e615587352f70c87b9e98126d03 upstream. -- snip -- - Missing mm/hmm.c and kernel/memremap.c unification. -- hmm code does not need fixes (no altmap) - Missing 7cc7867fb061 ("mm/devm_memremap_pages: enable sub-section remap") -- snip -- Patch series "mm/memory_hotplug: Shrink zones before removing memory", v6. This series fixes the access of uninitialized memmaps when shrinking zones/nodes and when removing memory. Also, it contains all fixes for crashes that can be triggered when removing certain namespace using memunmap_pages() - ZONE_DEVICE, reported by Aneesh. We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be more involved (we don't have SECTION_IS_ONLINE as an indicator), and shrinking is only of limited use (set_zone_contiguous() cannot detect the ZONE_DEVICE as contiguous). We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount of code to a minimum. Shrinking is especially necessary to keep zone->contiguous set where possible, especially, on memory unplug of DIMMs at zone boundaries. -------------------------------------------------------------------------- Zones are now properly shrunk when offlining memory blocks or when onlining failed. This allows to properly shrink zones on memory unplug even if the separate memory blocks of a DIMM were onlined to different zones or re-onlined to a different zone after offlining. Example: :/# cat /proc/zoneinfo Node 1, zone Movable spanned 0 present 0 managed 0 :/# echo "online_movable" > /sys/devices/system/memory/memory41/state :/# echo "online_movable" > /sys/devices/system/memory/memory43/state :/# cat /proc/zoneinfo Node 1, zone Movable spanned 98304 present 65536 managed 65536 :/# echo 0 > /sys/devices/system/memory/memory43/online :/# cat /proc/zoneinfo Node 1, zone Movable spanned 32768 present 32768 managed 32768 :/# echo 0 > /sys/devices/system/memory/memory41/online :/# cat /proc/zoneinfo Node 1, zone Movable spanned 0 present 0 managed 0 This patch (of 10): With an altmap, the memmap falling into the reserved altmap space are not initialized and, therefore, contain a garbage NID and a garbage zone. Make sure to read the NID/zone from a memmap that was initialized. This fixes a kernel crash that is observed when destroying a namespace: kernel BUG at include/linux/mm.h:1107! cpu 0x1: Vector: 700 (Program Check) at [c000000274087890] pc: c0000000004b9728: memunmap_pages+0x238/0x340 lr: c0000000004b9724: memunmap_pages+0x234/0x340 ... pid = 3669, comm = ndctl kernel BUG at include/linux/mm.h:1107! devm_action_release+0x30/0x50 release_nodes+0x268/0x2d0 device_release_driver_internal+0x174/0x240 unbind_store+0x13c/0x190 drv_attr_store+0x44/0x60 sysfs_kf_write+0x70/0xa0 kernfs_fop_write+0x1ac/0x290 __vfs_write+0x3c/0x70 vfs_write+0xe4/0x200 ksys_write+0x7c/0x140 system_call+0x5c/0x68 The "page_zone(pfn_to_page(pfn)" was introduced by 69324b8f4833 ("mm, devm_memremap_pages: add MEMORY_DEVICE_PRIVATE support"), however, I think we will never have driver reserved memory with MEMORY_DEVICE_PRIVATE (no altmap AFAIKS). [david@redhat.com: minimze code changes, rephrase description] Link: http://lkml.kernel.org/r/20191006085646.5768-2-david@redhat.com Fixes: 2c2a5af6fed2 ("mm, memory_hotplug: add nid parameter to arch_remove_memory") Signed-off-by: Aneesh Kumar K.V Signed-off-by: David Hildenbrand Cc: Dan Williams Cc: Jason Gunthorpe Cc: Logan Gunthorpe Cc: Ira Weiny Cc: Damian Tometzki Cc: Alexander Duyck Cc: Alexander Potapenko Cc: Andy Lutomirski Cc: Anshuman Khandual Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Dave Hansen Cc: Fenghua Yu Cc: Gerald Schaefer Cc: Greg Kroah-Hartman Cc: Halil Pasic Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jun Yao Cc: Mark Rutland Cc: Masahiro Yamada Cc: "Matthew Wilcox (Oracle)" Cc: Mel Gorman Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Oscar Salvador Cc: Pankaj Gupta Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Qian Cai Cc: Rich Felker Cc: Robin Murphy Cc: Steve Capper Cc: Thomas Gleixner Cc: Tom Lendacky Cc: Tony Luck Cc: Vasily Gorbik Cc: Vlastimil Babka Cc: Wei Yang Cc: Wei Yang Cc: Will Deacon Cc: Yoshinori Sato Cc: Yu Zhao Cc: [5.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: David Hildenbrand --- kernel/memremap.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index 2ee2e672d5fc..1ec1f8fd97f5 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -120,6 +120,7 @@ static void devm_memremap_pages_release(void *data) struct device *dev = pgmap->dev; struct resource *res = &pgmap->res; resource_size_t align_start, align_size; + struct page *first_page; unsigned long pfn; int nid; @@ -132,13 +133,16 @@ static void devm_memremap_pages_release(void *data) align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) - align_start; - nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT)); + /* make sure to access a memmap that was actually initialized */ + first_page = pfn_to_page(pfn_first(pgmap)); + + nid = page_to_nid(first_page); mem_hotplug_begin(); if (pgmap->type == MEMORY_DEVICE_PRIVATE) { pfn = align_start >> PAGE_SHIFT; - __remove_pages(page_zone(pfn_to_page(pfn)), pfn, - align_size >> PAGE_SHIFT, NULL); + __remove_pages(page_zone(first_page), pfn, + align_size >> PAGE_SHIFT, NULL); } else { arch_remove_memory(nid, align_start, align_size, pgmap->altmap_valid ? &pgmap->altmap : NULL);