From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758389Ab3LFNgN (ORCPT ); Fri, 6 Dec 2013 08:36:13 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:44340 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161680Ab3LFNDK (ORCPT ); Fri, 6 Dec 2013 08:03:10 -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 3.11 164/272] [media] af9035: Don't use dynamic static allocation Date: Fri, 6 Dec 2013 12:57:33 +0000 Message-Id: <1386334761-25517-165-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 7760e148350bf6df95662bc0db3734e9d991cb03 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-v2/af9035.c:142:1: warning: 'af9035_wr_regs' uses dynamic stack allocation [enabled by default] drivers/media/usb/dvb-usb-v2/af9035.c:305:1: warning: 'af9035_i2c_master_xfer' 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 Reviewed-by: Antti Palosaari Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Luis Henriques --- drivers/media/usb/dvb-usb-v2/af9035.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) diff --git a/drivers/media/usb/dvb-usb-v2/af9035.c b/drivers/media/usb/dvb-usb-v2/af9035.c index 1ea17dc..c8fcd78 100644 --- a/drivers/media/usb/dvb-usb-v2/af9035.c +++ b/drivers/media/usb/dvb-usb-v2/af9035.c @@ -21,6 +21,9 @@ #include "af9035.h" +/* Max transfer size done by I2C transfer functions */ +#define MAX_XFER_SIZE 64 + DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); static u16 af9035_checksum(const u8 *buf, size_t len) @@ -126,10 +129,16 @@ exit: /* write multiple registers */ static int af9035_wr_regs(struct dvb_usb_device *d, u32 reg, u8 *val, int len) { - u8 wbuf[6 + len]; + u8 wbuf[MAX_XFER_SIZE]; u8 mbox = (reg >> 16) & 0xff; struct usb_req req = { CMD_MEM_WR, mbox, sizeof(wbuf), wbuf, 0, NULL }; + if (6 + len > sizeof(wbuf)) { + dev_warn(&d->udev->dev, "%s: i2c wr: len=%d is too big!\n", + KBUILD_MODNAME, len); + return -EOPNOTSUPP; + } + wbuf[0] = len; wbuf[1] = 2; wbuf[2] = 0; @@ -228,9 +237,16 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, msg[1].len); } else { /* I2C */ - u8 buf[5 + msg[0].len]; + u8 buf[MAX_XFER_SIZE]; struct usb_req req = { CMD_I2C_RD, 0, sizeof(buf), buf, msg[1].len, msg[1].buf }; + + if (5 + msg[0].len > sizeof(buf)) { + dev_warn(&d->udev->dev, + "%s: i2c xfer: len=%d is too big!\n", + KBUILD_MODNAME, msg[0].len); + return -EOPNOTSUPP; + } req.mbox |= ((msg[0].addr & 0x80) >> 3); buf[0] = msg[1].len; buf[1] = msg[0].addr << 1; @@ -257,9 +273,16 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, msg[0].len - 3); } else { /* I2C */ - u8 buf[5 + msg[0].len]; + u8 buf[MAX_XFER_SIZE]; struct usb_req req = { CMD_I2C_WR, 0, sizeof(buf), buf, 0, NULL }; + + if (5 + msg[0].len > sizeof(buf)) { + dev_warn(&d->udev->dev, + "%s: i2c xfer: len=%d is too big!\n", + KBUILD_MODNAME, msg[0].len); + return -EOPNOTSUPP; + } req.mbox |= ((msg[0].addr & 0x80) >> 3); buf[0] = msg[0].len; buf[1] = msg[0].addr << 1; -- 1.8.3.2