From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751410AbeBWJgU (ORCPT ); Fri, 23 Feb 2018 04:36:20 -0500 Received: from foss.arm.com ([217.140.101.70]:51492 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750861AbeBWJgS (ORCPT ); Fri, 23 Feb 2018 04:36:18 -0500 Date: Fri, 23 Feb 2018 09:36:11 +0000 From: Lorenzo Pieralisi To: Kishon Vijay Abraham I Cc: Rolf Evers-Fischer , bhelgaas@google.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Rolf Evers-Fischer Subject: Re: [PATCH 1/2] pci: endpoint: Free func_name after last usage Message-ID: <20180223093611.GA25086@e107981-ln.cambridge.arm.com> References: <20180221124707.26308-1-embedded24@evers-fischer.de> <20180221124707.26308-2-embedded24@evers-fischer.de> <20180222181901.GA13694@e107981-ln.cambridge.arm.com> <9cdc8c1c-b448-b00b-d5b8-b664bd96f856@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9cdc8c1c-b448-b00b-d5b8-b664bd96f856@ti.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 23, 2018 at 11:40:49AM +0530, Kishon Vijay Abraham I wrote: > Hi Lorenzo, > > On Thursday 22 February 2018 11:49 PM, Lorenzo Pieralisi wrote: > > On Wed, Feb 21, 2018 at 01:47:06PM +0100, Rolf Evers-Fischer wrote: > >> From: Rolf Evers-Fischer > >> > >> This commit decreases the number of jump labels and ensures > >> that the next commit doesn't increase the number of occurrences > >> of 'kfree(func_name)'. > >> > >> Change-Id: I0d1b6fd652395b85f82b11c43bf9b7db512854d1 > >> Signed-off-by: Rolf Evers-Fischer > >> Signed-off-by: Rolf Evers-Fischer > >> --- > >> drivers/pci/endpoint/pci-epf-core.c | 7 ++----- > >> 1 file changed, 2 insertions(+), 5 deletions(-) > >> > >> diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c > >> index 766ce1dca2ec..23d0e128d1a5 100644 > >> --- a/drivers/pci/endpoint/pci-epf-core.c > >> +++ b/drivers/pci/endpoint/pci-epf-core.c > >> @@ -220,9 +220,10 @@ struct pci_epf *pci_epf_create(const char *name) > >> *buf = '\0'; > >> > >> epf->name = kstrdup(func_name, GFP_KERNEL); > >> + kfree(func_name); > > > > I am certainly missing something but what if we reworked the code > > and just: > > > > kstrdup(name, GFP_KERNEL); > > > > once instead of allocating another local copy (that we then have to > > free) ? > > name will be something like pci_epf_test.0 and in epf->name we want to just > have pci_epf_test. > > > > Reworded: why > > > > epf->name = func_name; > > memory should be allocated for epf->name before it can be initialized. IMO > without kstrdup, there will be a null pointer exception. I understand that but the point is that func_name *was* allocated with kstrdup() already I would like to understand why we need to do it twice (and kfree the first allocation). Lorenzo