Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753802AbbFWIMN (ORCPT ); Tue, 23 Jun 2015 04:12:13 -0400 Received: from mail-wg0-f45.google.com ([74.125.82.45]:34534 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932081AbbFWIL7 (ORCPT ); Tue, 23 Jun 2015 04:11:59 -0400 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= To: Darren Hart , Matthew Garrett , Michal Hocko Cc: platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, =?UTF-8?q?Pali=20Roh=C3=A1r?= , stable@vger.kernel.org Subject: [PATCH] dell-laptop: Fix allocating & freeing SMI buffer page Date: Tue, 23 Jun 2015 10:11:19 +0200 Message-Id: <1435047079-949-1-git-send-email-pali.rohar@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1434876063-13460-1-git-send-email-pali.rohar@gmail.com> References: <1434876063-13460-1-git-send-email-pali.rohar@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1983 Lines: 59 This commit fix kernel crash when probing for rfkill devices in dell-laptop driver failed. Function free_page() was incorrectly used on struct page * instead of virtual address of SMI buffer. This commit also simplify allocating page for SMI buffer by using __get_free_page() function instead of sequential call of functions alloc_page() and page_address(). Signed-off-by: Pali Rohár Acked-by: Michal Hocko Cc: stable@vger.kernel.org --- drivers/platform/x86/dell-laptop.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c index d688d80..2c1d5f5 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -305,7 +305,6 @@ static const struct dmi_system_id dell_quirks[] __initconst = { }; static struct calling_interface_buffer *buffer; -static struct page *bufferpage; static DEFINE_MUTEX(buffer_mutex); static int hwswitch_state; @@ -1896,12 +1895,11 @@ static int __init dell_init(void) * Allocate buffer below 4GB for SMI data--only 32-bit physical addr * is passed to SMI handler. */ - bufferpage = alloc_page(GFP_KERNEL | GFP_DMA32); - if (!bufferpage) { + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32); + if (!buffer) { ret = -ENOMEM; goto fail_buffer; } - buffer = page_address(bufferpage); ret = dell_setup_rfkill(); @@ -1965,7 +1963,7 @@ fail_backlight: cancel_delayed_work_sync(&dell_rfkill_work); dell_cleanup_rfkill(); fail_rfkill: - free_page((unsigned long)bufferpage); + free_page((unsigned long)buffer); fail_buffer: platform_device_del(platform_device); fail_platform_device2: -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/