This is a note to let you know that I've just added the patch titled
platform/x86: wmi: Call acpi_wmi_init() later
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: platform-x86-wmi-call-acpi_wmi_init-later.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 98b8e4e5c17bf87c1b18ed929472051dab39878c Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com Date: Wed, 3 Jan 2018 12:49:29 +0100 Subject: platform/x86: wmi: Call acpi_wmi_init() later
From: Rafael J. Wysocki rafael.j.wysocki@intel.com
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 noodles@earth.li Reported-by: Joonsoo Kim iamjoonsoo.kim@lge.com Tested-by: Jonathan McDowell noodles@earth.li Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Darren Hart (VMware) dvhart@infradead.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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);
Patches currently in stable-queue which might be from rafael.j.wysocki@intel.com are
queue-4.14/platform-x86-wmi-call-acpi_wmi_init-later.patch