From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932079AbbJTAvR (ORCPT ); Mon, 19 Oct 2015 20:51:17 -0400 Received: from mail.kernel.org ([198.145.29.136]:54984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751036AbbJTAvM (ORCPT ); Mon, 19 Oct 2015 20:51:12 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, =?UTF-8?q?Pali=20Roh=C3=A1r?= , Darren Hart , Zefan Li Subject: [PATCH 3.4 45/65] dell-laptop: Fix allocating & freeing SMI buffer page Date: Tue, 20 Oct 2015 08:47:55 +0800 Message-Id: <1445302095-4695-45-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1445302030-4607-1-git-send-email-lizf@kernel.org> References: <1445302030-4607-1-git-send-email-lizf@kernel.org> 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 From: Pali Rohár 3.4.110-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit b8830a4e71b15d0364ac8e6c55301eea73f211da upstream. 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 Signed-off-by: Darren Hart [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li --- 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 e6c08ee..3d67591 100644 --- a/drivers/platform/x86/dell-laptop.c +++ b/drivers/platform/x86/dell-laptop.c @@ -216,7 +216,6 @@ static struct dmi_system_id __devinitdata dell_quirks[] = { }; static struct calling_interface_buffer *buffer; -static struct page *bufferpage; static DEFINE_MUTEX(buffer_mutex); static int hwswitch_state; @@ -714,11 +713,10 @@ 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); + buffer = (void *)__get_free_page(GFP_KERNEL | GFP_DMA32); - if (!bufferpage) + if (!buffer) goto fail_buffer; - buffer = page_address(bufferpage); ret = dell_setup_rfkill(); @@ -787,7 +785,7 @@ fail_backlight: fail_filter: 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: -- 1.9.1