Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934970AbeAOMrf (ORCPT + 1 other); Mon, 15 Jan 2018 07:47:35 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:49674 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754993AbeAOMr3 (ORCPT ); Mon, 15 Jan 2018 07:47:29 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jonathan McDowell , Joonsoo Kim , "Rafael J. Wysocki" , "Darren Hart (VMware)" Subject: [PATCH 4.14 016/118] platform/x86: wmi: Call acpi_wmi_init() later Date: Mon, 15 Jan 2018 13:34:03 +0100 Message-Id: <20180115123416.243118721@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180115123415.325497625@linuxfoundation.org> References: <20180115123415.325497625@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rafael J. Wysocki commit 98b8e4e5c17bf87c1b18ed929472051dab39878c upstream. Calling acpi_wmi_init() at the subsys_initcall() level causes ordering issues to appear on some systems and they are difficult to reproduce, because there is no guaranteed ordering between subsys_initcall() calls, so they may occur in different orders on different systems. In particular, commit 86d9f48534e8 (mm/slab: fix kmemcg cache creation delayed issue) exposed one of these issues where genl_init() and acpi_wmi_init() are both called at the same initcall level, but the former must run before the latter so as to avoid a NULL pointer dereference. For this reason, move the acpi_wmi_init() invocation to the initcall_sync level which should still be early enough for things to work correctly in the WMI land. Link: https://marc.info/?t=151274596700002&r=1&w=2 Reported-by: Jonathan McDowell Reported-by: Joonsoo Kim Tested-by: Jonathan McDowell Signed-off-by: Rafael J. Wysocki Signed-off-by: Darren Hart (VMware) Signed-off-by: Greg Kroah-Hartman --- drivers/platform/x86/wmi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -1268,5 +1268,5 @@ static void __exit acpi_wmi_exit(void) bus_unregister(&wmi_bus_type); } -subsys_initcall(acpi_wmi_init); +subsys_initcall_sync(acpi_wmi_init); module_exit(acpi_wmi_exit);