From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752907AbbETL5P (ORCPT ); Wed, 20 May 2015 07:57:15 -0400 Received: from mail-wg0-f44.google.com ([74.125.82.44]:34907 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751418AbbETL5K (ORCPT ); Wed, 20 May 2015 07:57:10 -0400 Date: Wed, 20 May 2015 13:57:05 +0200 From: Ingo Molnar To: Colin Ian King Cc: Will Deacon , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , Russell King , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM: 8351/1: perf: fix memory leak on return Message-ID: <20150520115705.GA5273@gmail.com> References: <1431693789-9679-1-git-send-email-colin.king@canonical.com> <20150516070955.GA2429@gmail.com> <5559BAF7.70205@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5559BAF7.70205@canonical.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Colin Ian King wrote: > On 16/05/15 08:09, Ingo Molnar wrote: > > > > * Colin King wrote: > > > >> From: Colin Ian King > >> > >> Recent commit 3b8786ff7a1b31645ae2c26a2ec32dbd42ac1094 > >> ("ARM: 8352/1: perf: Fix the pmu node name in warning message") > >> introduced a memory leak of irqs on the "Don't bother with PPIs" > >> return path. This was picked up by static analysis by cppcheck: > >> > >> [arch/arm/kernel/perf_event_cpu.c:315]: (error) Memory leak: irqs > >> > >> simpele fix is to free irqs when returning. > >> > >> Signed-off-by: Colin Ian King > >> --- > >> arch/arm/kernel/perf_event_cpu.c | 4 +++- > >> 1 file changed, 3 insertions(+), 1 deletion(-) > >> > >> diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c > >> index 213919b..9e5b2a5 100644 > >> --- a/arch/arm/kernel/perf_event_cpu.c > >> +++ b/arch/arm/kernel/perf_event_cpu.c > >> @@ -311,8 +311,10 @@ static int of_pmu_irq_cfg(struct platform_device *pdev) > >> > >> /* Don't bother with PPIs; they're already affine */ > >> irq = platform_get_irq(pdev, 0); > >> - if (irq >= 0 && irq_is_percpu(irq)) > >> + if (irq >= 0 && irq_is_percpu(irq)) { > >> + kfree(irqs); > >> return 0; > >> + } > >> > >> for (i = 0; i < pdev->num_resources; ++i) { > >> struct device_node *dn; > > > > So returning from the middle of a function isn't very clean. > > > > Also, why do we return 0 in an error case? > > I believe that's explained in commit > 338d9dd3e2aee00a9198e8bf6e7d535d3feeaf32 ("ARM: 8351/1: perf: don't warn > about missing interrupt-affinity property for PPIs"): > > "PPIs are affine by nature, so the interrupt-affinity property is not > used and therefore we shouldn't print a warning in its absence." That should probably be mentioned in the fine code as well, to keep future generations from wondering. Thanks, Ingo