From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f71.google.com (mail-oi0-f71.google.com [209.85.218.71]) by kanga.kvack.org (Postfix) with ESMTP id DE69A6B0383 for ; Fri, 5 Jan 2018 18:30:24 -0500 (EST) Received: by mail-oi0-f71.google.com with SMTP id q67so2886062oig.14 for ; Fri, 05 Jan 2018 15:30:24 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id p198sor2251478oic.18.2018.01.05.15.30.23 for (Google Transport Security); Fri, 05 Jan 2018 15:30:23 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <2601877.IhOx20xkUK@aspire.rjw.lan> References: <20171208151159.urdcrzl5qpfd6jnu@earth.li> <2601877.IhOx20xkUK@aspire.rjw.lan> From: "Rafael J. Wysocki" Date: Sat, 6 Jan 2018 00:30:23 +0100 Message-ID: Subject: Re: [PATCH] ACPI / WMI: Call acpi_wmi_init() later Content-Type: text/plain; charset="UTF-8" Sender: owner-linux-mm@kvack.org List-ID: To: Andy Shevchenko , Darren Hart Cc: Jonathan McDowell , ACPI Devel Maling List , Linux Kernel Mailing List , Linux Memory Management List , Joonsoo Kim , Platform Driver , Andy Lutomirski On Wed, Jan 3, 2018 at 12:49 PM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > 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 Guys, this fixes a crash on boot. If there are no concerns/objections I will just take it through the ACPI tree. > --- > drivers/platform/x86/wmi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > Index: linux-pm/drivers/platform/x86/wmi.c > =================================================================== > --- linux-pm.orig/drivers/platform/x86/wmi.c > +++ linux-pm/drivers/platform/x86/wmi.c > @@ -1458,5 +1458,5 @@ static void __exit acpi_wmi_exit(void) > class_unregister(&wmi_bus_class); > } > > -subsys_initcall(acpi_wmi_init); > +subsys_initcall_sync(acpi_wmi_init); > module_exit(acpi_wmi_exit); > > -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org