From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758188Ab0JTGfu (ORCPT ); Wed, 20 Oct 2010 02:35:50 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:34747 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757787Ab0JTGft (ORCPT ); Wed, 20 Oct 2010 02:35:49 -0400 Date: Wed, 20 Oct 2010 08:35:42 +0200 From: Sascha Hauer To: Dan Williams Cc: Vasiliy Kulikov , kernel-janitors@vger.kernel.org, Linus Walleij , linux-kernel@vger.kernel.org Subject: Re: [PATCH] dma: imx-dma: fix signedness bug Message-ID: <20101020063542.GD28242@pengutronix.de> References: <1287327110-9158-1-git-send-email-segooon@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 08:33:18 up 108 days, 21:44, 21 users, load average: 0.21, 1.06, 0.90 User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: 2001:6f8:1178:2:215:17ff:fe12:23b0 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 19, 2010 at 03:26:05PM -0700, Dan Williams wrote: > On Sun, Oct 17, 2010 at 7:51 AM, Vasiliy Kulikov wrote: > > mxdmac->channel was unsigned, so check (imxdmac->channel < 0) for > > failed imx_dma_request_by_prio() made no sence.  Explicitly check > > signed values. > > > > Signed-off-by: Vasiliy Kulikov > > --- > >  drivers/dma/imx-dma.c |    2 +- > >  1 files changed, 1 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c > > index 346be62..75d870f 100644 > > --- a/drivers/dma/imx-dma.c > > +++ b/drivers/dma/imx-dma.c > > @@ -335,7 +335,7 @@ static int __init imxdma_probe(struct platform_device *pdev) > > > >                imxdmac->imxdma_channel = imx_dma_request_by_prio("dmaengine", > >                                DMA_PRIO_MEDIUM); > > -               if (imxdmac->channel < 0) > > +               if ((int)imxdmac->channel < 0) > >                        goto err_init; > > Should this be: > > if ((int)imxdmac->channel < 0) { > ret = -ENODEV; > goto err_init; > } > > ...because I get the following in my compilation tests. Yes, ret is clearly used uninitialized. I wonder why my gcc-4.3.2 compiler does not warn me about this :( Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |