This is a note to let you know that I've just added the patch titled

i2c: remove __init from i2c_register_board_info()

to the 4.4-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: i2c-remove-__init-from-i2c_register_board_info.patch and it can be found in the queue-4.4 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 5abe9b26847c65a698f38744a52635b287514294 Mon Sep 17 00:00:00 2001

From: "Luis R. Rodriguez" mcgrof@kernel.org Date: Tue, 7 Jun 2016 16:52:27 -0700 Subject: i2c: remove __init from i2c_register_board_info()

From: Luis R. Rodriguez mcgrof@kernel.org

commit 5abe9b26847c65a698f38744a52635b287514294 upstream.

As of next-20160607 with allyesconfig we get this linker failure:

MODPOST vmlinux.o WARNING: vmlinux.o(.text+0x21bc0d): Section mismatch in reference from the function intel_scu_devices_create() to the function .init.text:i2c_register_board_info()

This is caused by the fact that intel_scu_devices_create() calls i2c_register_board_info() and intel_scu_devices_create() is not annotated with __init. This typically involves manual code inspection and if one is certain this is correct we would just peg intel_scu_devices_create() with a __ref annotation.

In this case this would be wrong though as the intel_scu_devices_create() call is exported, and used in the ipc_probe() on drivers/platform/x86/intel_scu_ipc.c. The issue is that even though builtin_pci_driver(ipc_driver) is used this just exposes the probe routine, which can occur at any point in time if this bus supports hotplug. A race can happen between kernel_init_freeable() that calls the init calls (in this case registeres the intel_scu_ipc.c driver, and later free_initmem(), which would free the i2c_register_board_info(). If a probe happens later in boot i2c_register_board_info() would not be present and we should get a page fault.

Signed-off-by: Luis R. Rodriguez mcgrof@kernel.org [wsa: made function declaration a one-liner] Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/i2c/i2c-boardinfo.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/i2c/i2c-boardinfo.c +++ b/drivers/i2c/i2c-boardinfo.c @@ -56,9 +56,7 @@ EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bu * The board info passed can safely be __initdata, but be careful of embedded * pointers (for platform_data, functions, etc) since that won't be copied. */ -int __init -i2c_register_board_info(int busnum, - struct i2c_board_info const *info, unsigned len) +int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned len) { int status;

Patches currently in stable-queue which might be from mcgrof@kernel.org are

queue-4.4/i2c-remove-__init-from-i2c_register_board_info.patch