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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 5DC6FC7618B for ; Wed, 24 Jul 2019 14:30:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 336CC22ADB for ; Wed, 24 Jul 2019 14:30:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728132AbfGXOaW (ORCPT ); Wed, 24 Jul 2019 10:30:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33864 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728151AbfGXOaW (ORCPT ); Wed, 24 Jul 2019 10:30:22 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E9CCEC055673; Wed, 24 Jul 2019 14:30:21 +0000 (UTC) Received: from t460s.redhat.com (ovpn-117-47.ams2.redhat.com [10.36.117.47]) by smtp.corp.redhat.com (Postfix) with ESMTP id CE2B060A9F; Wed, 24 Jul 2019 14:30:17 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-acpi@vger.kernel.org, David Hildenbrand , "Rafael J. Wysocki" , Andrew Morton , Oscar Salvador , Michal Hocko Subject: [PATCH v1] ACPI / scan: Acquire device_hotplug_lock in acpi_scan_init() Date: Wed, 24 Jul 2019 16:30:17 +0200 Message-Id: <20190724143017.12841-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 24 Jul 2019 14:30:22 +0000 (UTC) Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org We end up calling __add_memory() without the device hotplug lock held. (I used a local patch to assert in __add_memory() that the device_hotplug_lock is held - I might upstream that as well soon) [ 26.771684] create_memory_block_devices+0xa4/0x140 [ 26.772952] add_memory_resource+0xde/0x200 [ 26.773987] __add_memory+0x6e/0xa0 [ 26.775161] acpi_memory_device_add+0x149/0x2b0 [ 26.776263] acpi_bus_attach+0xf1/0x1f0 [ 26.777247] acpi_bus_attach+0x66/0x1f0 [ 26.778268] acpi_bus_attach+0x66/0x1f0 [ 26.779073] acpi_bus_attach+0x66/0x1f0 [ 26.780143] acpi_bus_scan+0x3e/0x90 [ 26.780844] acpi_scan_init+0x109/0x257 [ 26.781638] acpi_init+0x2ab/0x30d [ 26.782248] do_one_initcall+0x58/0x2cf [ 26.783181] kernel_init_freeable+0x1bd/0x247 [ 26.784345] kernel_init+0x5/0xf1 [ 26.785314] ret_from_fork+0x3a/0x50 So perform the locking just like in acpi_device_hotplug(). Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Oscar Salvador Cc: Michal Hocko Signed-off-by: David Hildenbrand --- drivers/acpi/scan.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 0e28270b0fd8..cbc9d64b48dd 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -2204,7 +2204,9 @@ int __init acpi_scan_init(void) acpi_gpe_apply_masked_gpes(); acpi_update_all_gpes(); + lock_device_hotplug(); mutex_lock(&acpi_scan_lock); + /* * Enumerate devices in the ACPI namespace. */ @@ -2232,6 +2234,7 @@ int __init acpi_scan_init(void) out: mutex_unlock(&acpi_scan_lock); + unlock_device_hotplug(); return result; } -- 2.21.0