From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161727Ab3LFNDW (ORCPT ); Fri, 6 Dec 2013 08:03:22 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:44352 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161698Ab3LFNDO (ORCPT ); Fri, 6 Dec 2013 08:03:14 -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 3.11 167/272] [media] dibusb-common: Don't use dynamic static allocation Date: Fri, 6 Dec 2013 12:57:36 +0000 Message-Id: <1386334761-25517-168-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 1d7fa359d4c0fbb2756fa01cc47212908d90b7b0 upstream. Dynamic static allocation is evil, as Kernel stack is too low, and compilation complains about it on some archs: drivers/media/usb/dvb-usb/dibusb-common.c:124:1: warning: 'dibusb_i2c_msg' uses dynamic stack allocation [enabled by default] Instead, let's enforce a limit for the buffer to be the max size of a control URB payload data (64 bytes). Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Luis Henriques --- drivers/media/usb/dvb-usb/dibusb-common.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/dvb-usb/dibusb-common.c b/drivers/media/usb/dvb-usb/dibusb-common.c index c2dded9..6d68af0 100644 --- a/drivers/media/usb/dvb-usb/dibusb-common.c +++ b/drivers/media/usb/dvb-usb/dibusb-common.c @@ -12,6 +12,9 @@ #include #include "dibusb.h" +/* Max transfer size done by I2C transfer functions */ +#define MAX_XFER_SIZE 64 + static int debug; module_param(debug, int, 0644); MODULE_PARM_DESC(debug, "set debugging level (1=info (|-able))." DVB_USB_DEBUG_STATUS); @@ -105,11 +108,16 @@ EXPORT_SYMBOL(dibusb2_0_power_ctrl); static int dibusb_i2c_msg(struct dvb_usb_device *d, u8 addr, u8 *wbuf, u16 wlen, u8 *rbuf, u16 rlen) { - u8 sndbuf[wlen+4]; /* lead(1) devaddr,direction(1) addr(2) data(wlen) (len(2) (when reading)) */ + u8 sndbuf[MAX_XFER_SIZE]; /* lead(1) devaddr,direction(1) addr(2) data(wlen) (len(2) (when reading)) */ /* write only ? */ int wo = (rbuf == NULL || rlen == 0), len = 2 + wlen + (wo ? 0 : 2); + if (4 + wlen > sizeof(sndbuf)) { + warn("i2c wr: len=%d is too big!\n", wlen); + return -EOPNOTSUPP; + } + sndbuf[0] = wo ? DIBUSB_REQ_I2C_WRITE : DIBUSB_REQ_I2C_READ; sndbuf[1] = (addr << 1) | (wo ? 0 : 1); -- 1.8.3.2