From patchwork Sun Dec 7 00:34:49 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12584 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id A86DBDE012 for ; Sun, 7 Dec 2008 11:35:24 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from smtp1.linux-foundation.org (smtp1.linux-foundation.org [140.211.169.13]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "smtp.linux-foundation.org", Issuer "CA Cert Signing Authority" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 60CB2DDD01 for ; Sun, 7 Dec 2008 11:35:00 +1100 (EST) Received: from imap1.linux-foundation.org (imap1.linux-foundation.org [140.211.169.55]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id mB70Yo81019930 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 6 Dec 2008 16:34:51 -0800 Received: from y.localdomain (localhost [127.0.0.1]) by imap1.linux-foundation.org (8.13.5.20060308/8.13.5/Debian-3ubuntu1.1) with SMTP id mB70YnQS006531; Sat, 6 Dec 2008 16:34:49 -0800 Date: Sat, 6 Dec 2008 16:34:49 -0800 From: Andrew Morton To: Nicolas Palix Subject: Re: [PATCH linux-next] powerpc/powermac: Add missing of_node_put Message-Id: <20081206163449.60757c4a.akpm@linux-foundation.org> In-Reply-To: <200812021445.18670.npalix@diku.dk> References: <200812021445.18670.npalix@diku.dk> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 X-Spam-Status: No, hits=-3.4 required=5 tests=AWL, BAYES_00, OSDL_HEADER_SUBJECT_BRACKETED X-Spam-Checker-Version: SpamAssassin 3.2.4-osdl_revision__1.47__ X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.63 on 140.211.169.13 Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, Julia Lawall , paulus@samba.org X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org On Tue, 2 Dec 2008 14:45:18 +0100 Nicolas Palix wrote: > --- a/arch/powerpc/platforms/powermac/time.c > +++ b/arch/powerpc/platforms/powermac/time.c > @@ -265,12 +265,14 @@ int __init via_calibrate_decr(void) > struct resource rsrc; > > vias = of_find_node_by_name(NULL, "via-cuda"); > if (vias == 0) > vias = of_find_node_by_name(NULL, "via-pmu"); > if (vias == 0) > vias = of_find_node_by_name(NULL, "via"); > if (vias == 0 || of_address_to_resource(vias, 0, &rsrc)) > return 0; > + of_node_put(vias); > + This still misses a path - if that `return 0' is taken, we still leak the reference. This is reason #345 why sprinkling return statements all over your code is bad. I fixed it up thusly. Please check. of_node_put is needed before discarding a value received from of_find_node_by_name, eg in error handling code or when the device node is no longer used. The semantic match that catches the bug is as follows: (http://www.emn.fr/x-info/coccinelle/) // @r exists@ local idexpression struct device_node *n; position p1, p2; struct device_node *n1; statement S; identifier f; expression E; expression *ptr != NULL; @@ n@p1 = of_find_node_by_name(...) ... if (!n) S ... when != of_node_put(n) when != n1 = f(n,...) when != E = n when any when strict ( return \(0\|<+...n...+>\|ptr\); | return@p2 ...; | of_node_put(n); | n1 = f(n,...) | E = n ) @script:python@ p1 << r.p1; p2 << r.p2; @@ print "* file: %s of_find_node_by_name %s return %s" % (p1[0].file,p1[0].line,p2[0].line) // Signed-off-by: Nicolas Palix Signed-off-by: Julia Lawall --- index bcf50d7..800fcce 100644 Signed-off-by: Andrew Morton --- arch/powerpc/platforms/powermac/pci.c | 2 ++ arch/powerpc/platforms/powermac/time.c | 9 ++++++--- 2 files changed, 8 insertions(+), 3 deletions(-) diff -puN arch/powerpc/platforms/powermac/pci.c~powerpc-powermac-add-missing-of_node_put arch/powerpc/platforms/powermac/pci.c --- a/arch/powerpc/platforms/powermac/pci.c~powerpc-powermac-add-missing-of_node_put +++ a/arch/powerpc/platforms/powermac/pci.c @@ -661,6 +661,7 @@ static void __init init_second_ohare(voi pci_find_hose_for_OF_device(np); if (!hose) { printk(KERN_ERR "Can't find PCI hose for OHare2 !\n"); + of_node_put(np); return; } early_read_config_word(hose, bus, devfn, PCI_COMMAND, &cmd); @@ -669,6 +670,7 @@ static void __init init_second_ohare(voi early_write_config_word(hose, bus, devfn, PCI_COMMAND, cmd); } has_second_ohare = 1; + of_node_put(np); } /* diff -puN arch/powerpc/platforms/powermac/time.c~powerpc-powermac-add-missing-of_node_put arch/powerpc/platforms/powermac/time.c --- a/arch/powerpc/platforms/powermac/time.c~powerpc-powermac-add-missing-of_node_put +++ a/arch/powerpc/platforms/powermac/time.c @@ -270,11 +270,11 @@ int __init via_calibrate_decr(void) if (vias == 0) vias = of_find_node_by_name(NULL, "via"); if (vias == 0 || of_address_to_resource(vias, 0, &rsrc)) - return 0; + goto fail; via = ioremap(rsrc.start, rsrc.end - rsrc.start + 1); if (via == NULL) { printk(KERN_ERR "Failed to map VIA for timer calibration !\n"); - return 0; + goto fail; } /* set timer 1 for continuous interrupts */ @@ -297,8 +297,11 @@ int __init via_calibrate_decr(void) ppc_tb_freq = (dstart - dend) * 100 / 6; iounmap(via); - + return 1; +fail: + of_node_put(vias); + return 0; } #endif