From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YGlSk-0002oq-Ce for barebox@lists.infradead.org; Thu, 29 Jan 2015 09:32:35 +0000 Date: Thu, 29 Jan 2015 10:32:12 +0100 From: Sascha Hauer Message-ID: <20150129093212.GJ18908@pengutronix.de> References: <1422499613-683-1-git-send-email-yamada.m@jp.panasonic.com> <20150129090622.GZ12209@pengutronix.de> <20150129182138.3DA6.AA925319@jp.panasonic.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20150129182138.3DA6.AA925319@jp.panasonic.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH v2] param: add error check to __dev_add_param() To: Masahiro Yamada Cc: barebox@lists.infradead.org On Thu, Jan 29, 2015 at 06:21:39PM +0900, Masahiro Yamada wrote: > Hi Sascha, > > On Thu, 29 Jan 2015 10:06:22 +0100 > Sascha Hauer wrote: > > > On Thu, Jan 29, 2015 at 11:46:53AM +0900, Masahiro Yamada wrote: > > > If the argument, name is given with NULL, it would be probably > > > unexpected behavior. It should fail rather than register the > > > NULL-named parameter. > > > > > > If strdup() fails with out-of-memory, it should also fail > > > with -ENOMEM. > > > > > > Signed-off-by: Masahiro Yamada > > > --- > > > > > > Changes in v2: > > > - Fix the condition of returning -ENOMEM > > > > > > lib/parameter.c | 8 +++++++- > > > 1 file changed, 7 insertions(+), 1 deletion(-) > > > > > > diff --git a/lib/parameter.c b/lib/parameter.c > > > index 71262c4..02a89bb 100644 > > > --- a/lib/parameter.c > > > +++ b/lib/parameter.c > > > @@ -130,6 +130,13 @@ static int __dev_add_param(struct param_d *param, struct device_d *dev, const ch > > > if (get_param_by_name(dev, name)) > > > return -EEXIST; > > > > > > + if (!name) > > > + return -EINVAL; > > > > Name is used already two lines above so barebox will already be crashed > > before this triggers. > > > > Besides, I normally don't like these checks. dereferencing NULL pointers > > means you get a backtrace showing you what went wrong. Returning an error > > means adding code which in this case makes dev_add_param just fail > > silently because the return value often is not checked. > > > > OK, then how about dropping this -EINVAL check? Yes, please. > > I think the -ENOMEM check below is still useful. > ( strdup() returns NULL also when NULL is passed, > but in that case this line cannot be reached. > The problem is that is not apparent at a glance..) Note we also have xstrdup which crashes barebox on out of memory. This is usually the right thing to do when it's known that the allocation is small. 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 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox