From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-cys01nam02on0121.outbound.protection.outlook.com ([104.47.37.121]:11554 "EHLO NAM02-CY1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1032557AbeCAPin (ORCPT ); Thu, 1 Mar 2018 10:38:43 -0500 From: Sasha Levin To: "stable@vger.kernel.org" , "stable-commits@vger.kernel.org" CC: "Luis R. Rodriguez" , Wolfram Sang , Sasha Levin Subject: [added to the 4.1 stable tree] i2c: remove __init from i2c_register_board_info() Date: Thu, 1 Mar 2018 15:27:33 +0000 Message-ID: <20180301152116.1486-474-alexander.levin@microsoft.com> References: <20180301152116.1486-1-alexander.levin@microsoft.com> In-Reply-To: <20180301152116.1486-1-alexander.levin@microsoft.com> Content-Language: en-US Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org List-ID: From: "Luis R. Rodriguez" This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ Upstream commit 5abe9b26847c65a698f38744a52635b287514294 ] 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 [wsa: made function declaration a one-liner] Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/i2c-boardinfo.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/i2c/i2c-boardinfo.c b/drivers/i2c/i2c-boardinfo.c index 90e322959303..42c25aed671d 100644 --- a/drivers/i2c/i2c-boardinfo.c +++ b/drivers/i2c/i2c-boardinfo.c @@ -56,9 +56,7 @@ EXPORT_SYMBOL_GPL(__i2c_first_dynamic_bus_num); * The board info passed can safely be __initdata, but be careful of embed= ded * 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; =20 --=20 2.14.1