From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751783AbZGaGWv (ORCPT ); Fri, 31 Jul 2009 02:22:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751475AbZGaGWv (ORCPT ); Fri, 31 Jul 2009 02:22:51 -0400 Received: from cantor.suse.de ([195.135.220.2]:52329 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751024AbZGaGWu (ORCPT ); Fri, 31 Jul 2009 02:22:50 -0400 Date: Fri, 31 Jul 2009 08:22:49 +0200 Message-ID: From: Takashi Iwai To: Julia Lawall Cc: Johannes Berg , linuxppc-dev@ozlabs.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH 5/5] sound/aoa: Add kmalloc NULL tests In-Reply-To: References: <1248963420.16129.0.camel@johannes.local> User-Agent: Wanderlust/2.12.0 (Your Wildest Dreams) SEMI/1.14.6 (Maruoka) FLIM/1.14.7 (=?ISO-8859-4?Q?Sanj=F2?=) APEL/10.6 Emacs/22.3 (x86_64-suse-linux-gnu) MULE/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At Thu, 30 Jul 2009 16:29:54 +0200 (CEST), Julia Lawall wrote: > > On Thu, 30 Jul 2009, Johannes Berg wrote: > > > On Thu, 2009-07-30 at 16:11 +0200, Julia Lawall wrote: > > > From: Julia Lawall > > > > > > Check that the result of kzalloc is not NULL before a dereference. > > > > > irq_client = kzalloc(sizeof(struct pmf_irq_client), > > > GFP_KERNEL); > > > + if (!irq_client) { > > > + err = -ENOMEM; > > > + printk(KERN_ERR "snd-aoa: gpio layer failed to" > > > + " register %s irq (%d)\n", name, err); > > > + goto out_unlock; > > > + } > > > > Looks good, thanks, but I'd really drop the printk if only to not have > > the string there, that doesn't really seem interesting. > > The printk is based on similar error handling code a few lines later: But another problem is that the same error message is reused although the error condition is totally different. The kzalloc NULL isn't about the registration error. So, it's rather confusing. However, for this particular error path, I agree with Johannes; we can skip the error message since the error code ENOMEM is obvious. thanks, Takashi > > if (err) { > printk(KERN_ERR "snd-aoa: gpio layer failed to" > " register %s irq (%d)\n", name, > err); > kfree(irq_client); > goto out_unlock; > } > > Should the printk be removed in this case as well? Or is it ok to fail > silently in one case and not in the other? > > julia > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >