From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756738AbdEHTsq (ORCPT ); Mon, 8 May 2017 15:48:46 -0400 Received: from smtprelay0027.hostedemail.com ([216.40.44.27]:53657 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754883AbdEHTso (ORCPT ); Mon, 8 May 2017 15:48:44 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::::::::::,RULES_HIT:41:355:379:541:599:966:973:988:989:1260:1277:1311:1313:1314:1345:1359:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2196:2199:2393:2553:2559:2562:2693:2828:3138:3139:3140:3141:3142:3353:3622:3865:3866:3867:3868:3872:4250:4321:4385:5007:7576:10004:10400:10848:11026:11232:11658:11914:12296:12740:12760:12895:13069:13311:13357:13439:14096:14097:14659:14721:21080:21451:21627:30012:30054:30070:30090:30091,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:4,LUA_SUMMARY:none X-HE-Tag: sugar93_85f7d48fb685a X-Filterd-Recvd-Size: 2504 Message-ID: <1494265443.31950.62.camel@perches.com> Subject: Re: [PATCH] net: dsa: loop: Check for memory allocation failure From: Joe Perches To: Julia Lawall , David Laight Cc: "'Christophe JAILLET'" , "andrew@lunn.ch" , "vivien.didelot@savoirfairelinux.com" , "f.fainelli@gmail.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kernel-janitors@vger.kernel.org" In-Reply-To: References: <20170506052945.2639-1-christophe.jaillet@wanadoo.fr> <063D6719AE5E284EB5DD2968C1650D6DCFFE715E@AcuExch.aculab.com> Content-Type: text/plain; charset="ISO-8859-1" Date: Mon, 08 May 2017 10:44:03 -0700 Mime-Version: 1.0 X-Mailer: Evolution 3.22.6-1ubuntu1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote: > > On Mon, 8 May 2017, David Laight wrote: > > > From: Christophe JAILLET > > > Sent: 06 May 2017 06:30 > > > If 'devm_kzalloc' fails, a NULL pointer will be dereferenced. > > > Return -ENOMEM instead, as done for some other memory allocation just a > > > few lines above. > > > > ... > > > --- a/drivers/net/dsa/dsa_loop.c > > > +++ b/drivers/net/dsa/dsa_loop.c > > > @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev) > > > return -ENOMEM; > > > > > > ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL); > > > + if (!ps) > > > + return -ENOMEM; > > > + > > > ps->netdev = dev_get_by_name(&init_net, pdata->netdev); > > > if (!ps->netdev) > > > return -EPROBE_DEFER; > > > > On the face if it this code leaks like a sieve. > > I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use > devm functions. It's at least wasteful. Each time -EPROBE_DEFER occurs, another set of calls to dsa_switch_alloc and dev_kzalloc also occurs. Perhaps it'd be better to do: if (ps->netdev) { devm_kfree(&devmdev->dev, ps); devm_kfree(&mdiodev->dev, ds); return -EPROBE_DEFER; } From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Subject: Re: [PATCH] net: dsa: loop: Check for memory allocation failure Date: Mon, 08 May 2017 10:44:03 -0700 Message-ID: <1494265443.31950.62.camel@perches.com> References: <20170506052945.2639-1-christophe.jaillet@wanadoo.fr> <063D6719AE5E284EB5DD2968C1650D6DCFFE715E@AcuExch.aculab.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: 'Christophe JAILLET' , "andrew@lunn.ch" , "vivien.didelot@savoirfairelinux.com" , "f.fainelli@gmail.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kernel-janitors@vger.kernel.org" To: Julia Lawall , David Laight Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote: > > On Mon, 8 May 2017, David Laight wrote: > > > From: Christophe JAILLET > > > Sent: 06 May 2017 06:30 > > > If 'devm_kzalloc' fails, a NULL pointer will be dereferenced. > > > Return -ENOMEM instead, as done for some other memory allocation just a > > > few lines above. > > > > ... > > > --- a/drivers/net/dsa/dsa_loop.c > > > +++ b/drivers/net/dsa/dsa_loop.c > > > @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev) > > > return -ENOMEM; > > > > > > ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL); > > > + if (!ps) > > > + return -ENOMEM; > > > + > > > ps->netdev = dev_get_by_name(&init_net, pdata->netdev); > > > if (!ps->netdev) > > > return -EPROBE_DEFER; > > > > On the face if it this code leaks like a sieve. > > I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use > devm functions. It's at least wasteful. Each time -EPROBE_DEFER occurs, another set of calls to dsa_switch_alloc and dev_kzalloc also occurs. Perhaps it'd be better to do: if (ps->netdev) { devm_kfree(&devmdev->dev, ps); devm_kfree(&mdiodev->dev, ds); return -EPROBE_DEFER; } From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Date: Mon, 08 May 2017 17:44:03 +0000 Subject: Re: [PATCH] net: dsa: loop: Check for memory allocation failure Message-Id: <1494265443.31950.62.camel@perches.com> List-Id: References: <20170506052945.2639-1-christophe.jaillet@wanadoo.fr> <063D6719AE5E284EB5DD2968C1650D6DCFFE715E@AcuExch.aculab.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Julia Lawall , David Laight Cc: 'Christophe JAILLET' , "andrew@lunn.ch" , "vivien.didelot@savoirfairelinux.com" , "f.fainelli@gmail.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kernel-janitors@vger.kernel.org" On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote: > > On Mon, 8 May 2017, David Laight wrote: > > > From: Christophe JAILLET > > > Sent: 06 May 2017 06:30 > > > If 'devm_kzalloc' fails, a NULL pointer will be dereferenced. > > > Return -ENOMEM instead, as done for some other memory allocation just a > > > few lines above. > > > > ... > > > --- a/drivers/net/dsa/dsa_loop.c > > > +++ b/drivers/net/dsa/dsa_loop.c > > > @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev) > > > return -ENOMEM; > > > > > > ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL); > > > + if (!ps) > > > + return -ENOMEM; > > > + > > > ps->netdev = dev_get_by_name(&init_net, pdata->netdev); > > > if (!ps->netdev) > > > return -EPROBE_DEFER; > > > > On the face if it this code leaks like a sieve. > > I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use > devm functions. It's at least wasteful. Each time -EPROBE_DEFER occurs, another set of calls to dsa_switch_alloc and dev_kzalloc also occurs. Perhaps it'd be better to do: if (ps->netdev) { devm_kfree(&devmdev->dev, ps); devm_kfree(&mdiodev->dev, ds); return -EPROBE_DEFER; }