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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 B4702C2BB55 for ; Thu, 16 Apr 2020 17:10:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 726FA2078E for ; Thu, 16 Apr 2020 17:10:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 726FA2078E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 23F3A8E00D4; Thu, 16 Apr 2020 13:10:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1EF938E00BC; Thu, 16 Apr 2020 13:10:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0DE998E00D4; Thu, 16 Apr 2020 13:10:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0045.hostedemail.com [216.40.44.45]) by kanga.kvack.org (Postfix) with ESMTP id EC9518E00BC for ; Thu, 16 Apr 2020 13:10:28 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id A0EDB180CE726 for ; Thu, 16 Apr 2020 17:10:28 +0000 (UTC) X-FDA: 76714356936.13.cast59_414924eb9463 X-HE-Tag: cast59_414924eb9463 X-Filterd-Recvd-Size: 4539 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Thu, 16 Apr 2020 17:10:27 +0000 (UTC) IronPort-SDR: jEhvTExJ1sP8qE+WpniAdW+cgwNq6bHBY56RdHNrozeUwxw2johQuLrmwTyhN9RFDdRLg6AfXo aJpo3BChkxOA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2020 10:10:26 -0700 IronPort-SDR: BUMyk+/UbxoauHN0IxO7bK+rlh2kh7Gv8MhlgQeL4SPuwWM2GSGRk5lomtWT8e1uo9Wki/3Y2B cQE7/YqBpMiw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,391,1580803200"; d="scan'208";a="242721569" Received: from vverma7-mobl4.lm.intel.com ([10.254.27.78]) by orsmga007.jf.intel.com with ESMTP; 16 Apr 2020 10:10:24 -0700 From: Vishal Verma To: Cc: , Vishal Verma , Michal Hocko , David Hildenbrand , Dan Williams , Dave Hansen Subject: [PATCH v4] mm/memory_hotplug: refrain from adding memory into an impossible node Date: Thu, 16 Apr 2020 11:10:19 -0600 Message-Id: <20200416171019.24433-1-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.21.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: A misbehaving qemu created a situation where the ACPI SRAT table advertised one fewer proximity domains than intended. The NFIT table did describe all the expected proximity domains. This caused the device dax driver to assign an impossible target_node to the device, and when hotplugged as system memory, this would fail with the following signature: [ +0.001627] BUG: kernel NULL pointer dereference, address: 0000000000= 000088 [ +0.001331] #PF: supervisor read access in kernel mode [ +0.000975] #PF: error_code(0x0000) - not-present page [ +0.000976] PGD 80000001767d4067 P4D 80000001767d4067 PUD 10e0c4067 P= MD 0 [ +0.001338] Oops: 0000 [#1] SMP PTI [ +0.000676] CPU: 4 PID: 22737 Comm: kswapd3 Tainted: G O = 5.6.0-rc5 #9 [ +0.001457] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ +0.001990] RIP: 0010:prepare_kswapd_sleep+0x7c/0xc0 [ +0.000780] Code: 89 df e8 87 fd ff ff 89 c2 31 c0 84 d2 74 e6 0f 1f = 44 00 00 48 8b 05 fb af 7a 01 48 63 93 88 1d 01 00 48 = 8b 84 d0 20 0f 00 00 <48> 3b 98 88 00 00 00 75 28 f0 80 a0 80 00 00 00 fe f0 80 a3 38 20 [ +0.002877] RSP: 0018:ffffc900017a3e78 EFLAGS: 00010202 [ +0.000805] RAX: 0000000000000000 RBX: ffff8881209e0000 RCX: 00000000= 00000000 [ +0.001115] RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff8881= 209e0e80 [ +0.001098] RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000= 00008000 [ +0.001092] R10: 0000000000000000 R11: 0000000000000003 R12: 00000000= 00000003 [ +0.001092] R13: 0000000000000003 R14: 0000000000000000 R15: ffffc900= 017a3ec8 [ +0.001091] FS: 0000000000000000(0000) GS:ffff888318c00000(0000) knl= GS:0000000000000000 [ +0.001275] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000882] CR2: 0000000000000088 CR3: 0000000120b50002 CR4: 00000000= 001606e0 [ +0.001095] Call Trace: [ +0.000388] kswapd+0x103/0x520 [ +0.000494] ? finish_wait+0x80/0x80 [ +0.000547] ? balance_pgdat+0x5a0/0x5a0 [ +0.000607] kthread+0x120/0x140 [ +0.000508] ? kthread_create_on_node+0x60/0x60 [ +0.000706] ret_from_fork+0x3a/0x50 Add a check in the add_memory path to fail if the node to which we are adding memory is in the node_possible_map Cc: Michal Hocko Cc: David Hildenbrand Cc: Dan Williams Cc: Dave Hansen Signed-off-by: Vishal Verma --- mm/memory_hotplug.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0a54ffac8c68..ddd3347edd54 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1005,6 +1005,11 @@ int __ref add_memory_resource(int nid, struct reso= urce *res) if (ret) return ret; =20 + if (!node_possible(nid)) { + WARN(1, "node %d was absent from the node_possible_map\n", nid); + return -ENXIO; + } + mem_hotplug_begin(); =20 /* --=20 2.21.1