From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162723Ab3LFNer (ORCPT ); Fri, 6 Dec 2013 08:34:47 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:44360 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758270Ab3LFNDR (ORCPT ); Fri, 6 Dec 2013 08:03:17 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Mauro Carvalho Chehab , Luis Henriques Subject: [PATCH 3.11 169/272] [media] av7110_hw: Don't use dynamic static allocation Date: Fri, 6 Dec 2013 12:57:38 +0000 Message-Id: <1386334761-25517-170-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> References: <1386334761-25517-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mauro Carvalho Chehab commit 5bf30b3bc4ff80ef71a733a1f459cca4fa507892 upstream. Dynamic static allocation is evil, as Kernel stack is too low, and compilation complains about it on some archs: drivers/media/pci/ttpci/av7110_hw.c:510:1: warning: 'av7110_fw_cmd' uses dynamic stack allocation [enabled by default] Instead, let's enforce a limit for the buffer. In the specific case of this driver, the maximum fw command size is 6 + 2, as checked using: $ git grep -A1 av7110_fw_cmd drivers/media/pci/ttpci/ So, use 8 for the buffer size. Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Luis Henriques --- drivers/media/pci/ttpci/av7110_hw.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/media/pci/ttpci/av7110_hw.c b/drivers/media/pci/ttpci/av7110_hw.c index f1cbfe5..6299d5d 100644 --- a/drivers/media/pci/ttpci/av7110_hw.c +++ b/drivers/media/pci/ttpci/av7110_hw.c @@ -22,7 +22,7 @@ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * Or, point your browser to http://www.gnu.org/copyleft/gpl.html * - * the project's page is at http://www.linuxtv.org/ + * the project's page is at http://www.linuxtv.org/ */ /* for debugging ARM communication: */ @@ -40,6 +40,14 @@ #define _NOHANDSHAKE +/* + * Max transfer size done by av7110_fw_cmd() + * + * The maximum size passed to this function is 6 bytes. The buffer also + * uses two additional ones for type and size. So, 8 bytes is enough. + */ +#define MAX_XFER_SIZE 8 + /**************************************************************************** * DEBI functions ****************************************************************************/ @@ -488,11 +496,18 @@ static int av7110_send_fw_cmd(struct av7110 *av7110, u16* buf, int length) int av7110_fw_cmd(struct av7110 *av7110, int type, int com, int num, ...) { va_list args; - u16 buf[num + 2]; + u16 buf[MAX_XFER_SIZE]; int i, ret; // dprintk(4, "%p\n", av7110); + if (2 + num > sizeof(buf)) { + printk(KERN_WARNING + "%s: %s len=%d is too big!\n", + KBUILD_MODNAME, __func__, num); + return -EINVAL; + } + buf[0] = ((type << 8) | com); buf[1] = num; -- 1.8.3.2