From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55478C433DF for ; Sat, 16 May 2020 01:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3567B2065C for ; Sat, 16 May 2020 01:17:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727098AbgEPBRN (ORCPT ); Fri, 15 May 2020 21:17:13 -0400 Received: from netrider.rowland.org ([192.131.102.5]:47113 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726204AbgEPBRM (ORCPT ); Fri, 15 May 2020 21:17:12 -0400 Received: (qmail 14004 invoked by uid 500); 15 May 2020 21:17:11 -0400 Date: Fri, 15 May 2020 21:17:11 -0400 From: Alan Stern To: Tang Bin Cc: Colin King , Greg Kroah-Hartman , Zhang Shengju , linux-usb@vger.kernel.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH][next] USB: EHCI: ehci-mv: fix less than zero comparisonof an unsigned int Message-ID: <20200516011711.GA13833@rowland.harvard.edu> References: <20200515165453.104028-1-colin.king@canonical.com> <20200515172121.GA5498@rowland.harvard.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 16, 2020 at 07:23:42AM +0800, Tang Bin wrote: > Hi Alan & Colin： > > On 2020/5/16 1:21, Alan Stern wrote: > > On Fri, May 15, 2020 at 05:54:53PM +0100, Colin King wrote: > > > From: Colin Ian King > > > > > > The comparison of hcd->irq to less than zero for an error check will > > > never be true because hcd->irq is an unsigned int. Fix this by > > > assigning the int retval to the return of platform_get_irq and checking > > > this for the -ve error condition and assigning hcd->irq to retval. > > > > > > Addresses-Coverity: ("Unsigned compared against 0") > > > Fixes: c856b4b0fdb5 ("USB: EHCI: ehci-mv: fix error handling in mv_ehci_probe()") > > > Signed-off-by: Colin Ian King > > > --- > > Thanks to Coverity for spotting this. Any reason why it didn't spot > > exactly the same mistake in the ohci-da8xx.c driver? > > I just looked at the code and wondered whether it would be more appropriate > to modify the header file "hcd.h".  Since 'irq' might be an negative, why > not just modify the variables in the 'struct usb_hcd',  'unsigned int  > irq'--> 'int irq'? After all, it's a public one. I think the code in the drivers should be changed. The reason is if platform_get_irq() returns a negative value, then that value should be what the probe function returns. Alan Stern