Patch "platform/x86: wmi: Call acpi_wmi_init() later" has been added to the 4.14-stable tree

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;a=summary

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 <[email protected]> know about it.

From: "Rafael J. Wysocki" <[email protected]>
Date: Wed, 3 Jan 2018 12:49:29 +0100
Subject: platform/x86: wmi: Call acpi_wmi_init() later

From: Rafael J. Wysocki <[email protected]>

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.

---
 drivers/platform/x86/wmi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

@@ -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 [email protected] are

queue-4.14/platform-x86-wmi-call-acpi_wmi_init-later.patch