From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755534AbcESX6s (ORCPT ); Thu, 19 May 2016 19:58:48 -0400 Received: from outbound.smtp.vt.edu ([198.82.183.121]:58011 "EHLO omr2.cc.vt.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755375AbcESX6r (ORCPT ); Thu, 19 May 2016 19:58:47 -0400 X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.6+dev To: Alan Stern , Andrey Ryabinin cc: Oliver Neukum , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: [PATCH] - silence UBSAN complaint in ehci-hcd. From: Valdis Kletnieks Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 19 May 2016 17:19:00 -0400 Message-ID: <14469.1463692740@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org UBSAN throws a complaint: [ 2.418579] UBSAN: Undefined behaviour in drivers/usb/host/ehci-hub.c:877:47 [ 2.418582] index -1 is out of range for type 'u32 [1]' though it's only on the hostpc[] part, not on the port_status[] on the previous line which has the same exact index calculation. The root cause is that the first declaration is port_status[0], which uses a GCC extension and UBSAN is smart enough to realize the programmer is doing something intentionally odd. However, the problematic declaration is hostpc[1], which doesn't have the "I know what I'm doing" semantics of [0]. Change the declaration to match. Signed-Off-By: Valdis Kletnieks --- a/include/linux/usb/ehci_def.h 2015-01-06 01:04:24.342436706 -0500 +++ b/include/linux/usb/ehci_def.h 2016-05-19 13:57:20.869304540 -0400 @@ -180,11 +180,11 @@ struct ehci_regs { * PORTSCx */ /* HOSTPC: offset 0x84 */ - u32 hostpc[1]; /* HOSTPC extension */ + u32 hostpc[0]; /* HOSTPC extension */ #define HOSTPC_PHCD (1<<22) /* Phy clock disable */ #define HOSTPC_PSPD (3<<25) /* Port speed detection */ - u32 reserved5[16]; + u32 reserved5[17]; /* USBMODE_EX: offset 0xc8 */ u32 usbmode_ex; /* USB Device mode extension */