From patchwork Tue Nov 5 10:01:36 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 3141091 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id DA3BDBEEB2 for ; Tue, 5 Nov 2013 13:04:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9CFB120588 for ; Tue, 5 Nov 2013 13:04:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81F5C2061D for ; Tue, 5 Nov 2013 13:04:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754840Ab3KENDz (ORCPT ); Tue, 5 Nov 2013 08:03:55 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:43301 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754779Ab3KENDv (ORCPT ); Tue, 5 Nov 2013 08:03:51 -0500 Received: from [177.143.133.66] (helo=smtp.w2.samsung.com) by bombadil.infradead.org with esmtpsa (Exim 4.80.1 #2 (Red Hat Linux)) id 1VdgIQ-0007gU-RS; Tue, 05 Nov 2013 13:03:51 +0000 Received: from mchehab by smtp.w2.samsung.com with local (Exim 4.80.1) (envelope-from ) id 1VddSC-00080Y-F6; Tue, 05 Nov 2013 08:01:44 -0200 From: Mauro Carvalho Chehab Cc: Mauro Carvalho Chehab , Linux Media Mailing List , Mauro Carvalho Chehab Subject: [PATCH v3 23/29] [media] dibusb-common: Don't use dynamic static allocation Date: Tue, 5 Nov 2013 08:01:36 -0200 Message-Id: <1383645702-30636-24-git-send-email-m.chehab@samsung.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1383645702-30636-1-git-send-email-m.chehab@samsung.com> References: <1383645702-30636-1-git-send-email-m.chehab@samsung.com> To: unlisted-recipients:; (no To-header on input) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- 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 c2dded92f1d3..6d68af0c49c8 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);