From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757934Ab2IMMnO (ORCPT ); Thu, 13 Sep 2012 08:43:14 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:51458 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754689Ab2IMMnM (ORCPT ); Thu, 13 Sep 2012 08:43:12 -0400 Message-ID: <5051D4D4.7060906@linux.vnet.ibm.com> Date: Thu, 13 Sep 2012 14:43:00 +0200 From: Peter Oberparleiter MIME-Version: 1.0 To: Dan Carpenter CC: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [patch] gcov: cleanup an allocation in new_node() References: <20120911111333.GD22259@elgon.mountain> In-Reply-To: <20120911111333.GD22259@elgon.mountain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12091312-5806-0000-0000-0000198E9950 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11.09.2012 13:13, Dan Carpenter wrote: > 1) kcalloc(1, ...) can be replaced with kzalloc(). > 2) There was a small leak if the debugfs_create_dir() fails. > 3) I removed a pr_warning("out of memory\n") because kmalloc() already > prints a more useful failure message in the unlikely case of an > allocation failure. > > Signed-off-by: Dan Carpenter > > diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c > index 9bd0934..132168f 100644 > --- a/kernel/gcov/fs.c > +++ b/kernel/gcov/fs.c > @@ -437,7 +437,7 @@ static struct gcov_node *new_node(struct gcov_node *parent, > if (!node) > goto err_nomem; > if (info) { > - node->loaded_info = kcalloc(1, sizeof(struct gcov_info *), > + node->loaded_info = kzalloc(sizeof(struct gcov_info *), > GFP_KERNEL); I'd like to keep using kcalloc here since node->loaded_info is an array. > if (!node->loaded_info) > goto err_nomem; > @@ -451,8 +451,7 @@ static struct gcov_node *new_node(struct gcov_node *parent, > node->dentry = debugfs_create_dir(node->name, parent->dentry); > if (!node->dentry) { > pr_warning("could not create file\n"); > - kfree(node); > - return NULL; > + goto err_info; I agree that this is a potential memory leak - good find! > } > if (info) > add_links(node, parent->dentry); > @@ -461,9 +460,11 @@ static struct gcov_node *new_node(struct gcov_node *parent, > > return node; > > +err_info: > + if (info) > + kfree(node->loaded_info); The 'if' here is not necessary: node->loaded_info is either zero (kfree tolerates NULL) or requires freeing. With the removal of the pr_warning below, the additional kfree can also be added to err_nomem (no need for another label) though then it should probably also be renamed. > err_nomem: > kfree(node); > - pr_warning("out of memory\n"); > return NULL; > } > > Regards, Peter Oberparleiter -- Peter Oberparleiter Linux on System z Development - IBM Germany