From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751663AbaIJQt3 (ORCPT ); Wed, 10 Sep 2014 12:49:29 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:32983 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750956AbaIJQt2 (ORCPT ); Wed, 10 Sep 2014 12:49:28 -0400 Date: Wed, 10 Sep 2014 09:49:17 -0700 From: Darren Hart To: Frans Klaver Cc: Paul Bolle , "Rafael J. Wysocki" , Greg Kroah-Hartman , Corentin Chary , Matthew Garrett , acpi4asus-user , platform-driver-x86 , linux-kernel@vger.kernel.org, Rafael Wysocki Subject: Re: [PATCH] eeepc-laptop: remove possible use of uninitialized value Message-ID: <20140910164916.GA48285@vmdeb7> References: <1409784805-14190-1-git-send-email-fransklaver@gmail.com> <1409814488.5546.63.camel@x220> <20140906021757.GA9197@vmdeb7> <7288841.ayNsq2yeGO@vostro.rjw.lan> <1410252608.22255.5.camel@x220> <20140910033304.GB39541@vmdeb7> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 10, 2014 at 04:42:49PM +0200, Frans Klaver wrote: > On Wed, Sep 10, 2014 at 5:33 AM, Darren Hart wrote: > > On Tue, Sep 09, 2014 at 10:50:08AM +0200, Paul Bolle wrote: > >> Hi Darren, > >> > >> On Sat, 2014-09-06 at 23:17 +0200, Rafael J. Wysocki wrote: > >> > On Friday, September 05, 2014 07:17:57 PM Darren Hart wrote: > >> > > On Thu, Sep 04, 2014 at 09:08:08AM +0200, Paul Bolle wrote: > >> > > [...] > >> > > > static ssize_t store_sys_acpi(struct device *dev, int cm, > >> > > > @@ -278,12 +276,13 @@ static ssize_t store_sys_acpi(struct device *dev, int cm, > >> > > > struct eeepc_laptop *eeepc = dev_get_drvdata(dev); > >> > > > int rv, value; > >> > > > > >> > > > - rv = parse_arg(buf, count, &value); > >> > > > - if (rv > 0) > >> > > > - value = set_acpi(eeepc, cm, value); > >> > > > + rv = parse_arg(buf, &value); > >> > > > + if (rv < 0) > >> > > > + return rv; > >> > > > + value = set_acpi(eeepc, cm, value); > >> > > > if (value < 0) > >> > > > >> > > I suppose it's harmless, but it would be more explicit to reuse rv here instead > >> > > of value. > >> > >> Fine with me. > >> > >> > > > return -EIO; > >> > > > >> > > And as with Frans' version, I suggest propogating the error. We're talking about > >> > > a missing/invalid ACPI control method name here, ENODEV seems approprirate. > >> > > > >> > > Rafael, do you have a strong preference about what to return in such an event? > >> > > >> > No, I don't, although -ENXIO could be used here too. > >> > >> If you could say what value you'd like best I'll resend using that > >> value. (I don't know what the effect is of using a specific error here, > >> so I guess I'll have to bluff about it in the commit explanation.) > > > > First, I would prefer we propogate the error code rather than remap it. > > > > We could consider changing what the callee returns... > > > > #define EIO 5 /* I/O error */ > > #define ENXIO 6 /* No such device or address */ > > #define ENODEV 19 /* No such device */ > > > > Of those, ENXIO seems like the most appropriate in this case. > > Would it be fair to say that for consistency we should then also > change the return values of acpi_setter_handle()? It has the same > basic layout and checks as set_acpi() and get_acpi() have. Yes, that would be appropriate as well. -- Darren Hart Intel Open Source Technology Center