Path: news.gmane.org!not-for-mail From: Mika Westerberg Newsgroups: gmane.linux.kernel.gpio,gmane.linux.kernel Subject: [PATCH] gpio / ACPI: Don't crash on NULL chip->dev Date: Mon, 31 Mar 2014 15:16:49 +0300 Lines: 114 Approved: news@gmane.org Message-ID: <1396268209-19108-1-git-send-email-mika.westerberg@linux.intel.com> NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1396268225 9280 80.91.229.3 (31 Mar 2014 12:17:05 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 31 Mar 2014 12:17:05 +0000 (UTC) Cc: Alexandre Courbot , Sabrina Dubroca , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Mika Westerberg To: Linus Walleij Original-X-From: linux-gpio-owner@vger.kernel.org Mon Mar 31 14:16:58 2014 Return-path: Envelope-to: glg-linux-gpio@plane.gmane.org Original-Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WUb96-00049j-5K for glg-linux-gpio@plane.gmane.org; Mon, 31 Mar 2014 14:16:56 +0200 Original-Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752154AbaCaMQz (ORCPT ); Mon, 31 Mar 2014 08:16:55 -0400 Original-Received: from mga11.intel.com ([192.55.52.93]:46420 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751749AbaCaMQy (ORCPT ); Mon, 31 Mar 2014 08:16:54 -0400 Original-Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 31 Mar 2014 05:16:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,764,1389772800"; d="scan'208";a="510938110" Original-Received: from blue.fi.intel.com ([10.237.72.156]) by fmsmga002.fm.intel.com with ESMTP; 31 Mar 2014 05:16:50 -0700 Original-Received: by blue.fi.intel.com (Postfix, from userid 1004) id 73976E0098; Mon, 31 Mar 2014 15:16:49 +0300 (EEST) X-Mailer: git-send-email 1.9.1 Original-Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Xref: news.gmane.org gmane.linux.kernel.gpio:2461 gmane.linux.kernel:1675129 Archived-At: Commit aa92b6f689ac (gpio / ACPI: Allocate ACPI specific data directly in acpi_gpiochip_add()) moved ACPI handle checking to acpi_gpiochip_add() but forgot to check whether chip->dev is NULL before dereferencing it. Since chip->dev pointer is optional we can end up with crash like following: BUG: unable to handle kernel NULL pointer dereference at 00000138 IP: [] acpi_gpiochip_add+0x13/0x190 *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP Modules linked in: ssb(+) ... CPU: 0 PID: 512 Comm: modprobe Tainted: G W 3.14.0-rc7-next-20140324-t1 #24 Hardware name: Dell Inc. Latitude D830 /0UY141, BIOS A02 06/07/2007 task: f5799900 ti: f543e000 task.ti: f543e000 EIP: 0060:[] EFLAGS: 00010282 CPU: 0 EIP is at acpi_gpiochip_add+0x13/0x190 EAX: 00000000 EBX: f57824c4 ECX: 00000000 EDX: 00000000 ESI: f57824c4 EDI: 00000010 EBP: f543fc54 ESP: f543fc40 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 CR0: 8005003b CR2: 00000138 CR3: 355f8000 CR4: 000007d0 Stack: f543fc5c fd1f7790 f57824c4 000000be 00000010 f543fc84 c1269f4e f543fc74 fd1f78bd 00008002 f57822b0 f5782090 fd1f8400 00000286 fd1f9994 00000000 f5782000 f543fc8c fd1f7e39 f543fcc8 fd1f0bd8 000000c0 00000000 00000000 Call Trace: [] ? ssb_pcie_mdio_write+0xa0/0xd0 [ssb] [] gpiochip_add+0xee/0x300 [] ? ssb_pcicore_serdes_workaround+0xfd/0x140 [ssb] [] ssb_gpio_init+0x89/0xa0 [ssb] [] ssb_attach_queued_buses+0xc8/0x2d0 [ssb] [] ssb_bus_register+0x185/0x1f0 [ssb] [] ? ssb_pci_xtal+0x220/0x220 [ssb] [] ssb_bus_pcibus_register+0x2c/0x80 [ssb] [] ssb_pcihost_probe+0x9c/0x110 [ssb] [] pci_device_probe+0x6f/0xc0 [] ? sysfs_create_link+0x25/0x40 [] driver_probe_device+0x79/0x360 [] ? pci_match_device+0xb2/0xc0 [] __driver_attach+0x71/0x80 [] ? __device_attach+0x40/0x40 [] bus_for_each_dev+0x47/0x80 [] driver_attach+0x1e/0x20 [] ? __device_attach+0x40/0x40 [] bus_add_driver+0x157/0x230 [] driver_register+0x59/0xe0 ... Fix this by checking chip->dev pointer against NULL first. Also we can now remove redundant check in acpi_gpiochip_request/free_interrupts(). Reported-by: Sabrina Dubroca Signed-off-by: Mika Westerberg --- Sabrina, Can you please re-test this and provide your tested-by? I changed the patch a bit to remove redundant checks. Just to be sure that I don't accidentally break something. Thanks. drivers/gpio/gpiolib-acpi.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index bf0f8b476696..d5be56fe689e 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -233,7 +233,7 @@ static void acpi_gpiochip_request_interrupts(struct acpi_gpio_chip *acpi_gpio) { struct gpio_chip *chip = acpi_gpio->chip; - if (!chip->dev || !chip->to_irq) + if (!chip->to_irq) return; INIT_LIST_HEAD(&acpi_gpio->events); @@ -253,7 +253,7 @@ static void acpi_gpiochip_free_interrupts(struct acpi_gpio_chip *acpi_gpio) struct acpi_gpio_event *event, *ep; struct gpio_chip *chip = acpi_gpio->chip; - if (!chip->dev || !chip->to_irq) + if (!chip->to_irq) return; list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) { @@ -501,6 +501,9 @@ void acpi_gpiochip_add(struct gpio_chip *chip) acpi_handle handle; acpi_status status; + if (!chip || !chip->dev) + return; + handle = ACPI_HANDLE(chip->dev); if (!handle) return; @@ -531,6 +534,9 @@ void acpi_gpiochip_remove(struct gpio_chip *chip) acpi_handle handle; acpi_status status; + if (!chip || !chip->dev) + return; + handle = ACPI_HANDLE(chip->dev); if (!handle) return; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html