From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BDEF61429A; Fri, 10 May 2024 16:49:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715359786; cv=none; b=Vx0jpzu/yRWfEcoIMokKZo7IyaFxXeJR7NfCWkZ4d8U5/h0keAlQWNQLS86KT5kRq1eiEWBlnQsYCcZUoNcYWfYpYeRAV8ekLHbmPrKGUEuxtaPoQIHSOR+wPWZbhhF2XoYtJQc5TaVsGG3SnlPjPQn7tU1+UD4SNcnfi8metQA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715359786; c=relaxed/simple; bh=GbCNIFOQBJPFUW1zv45XMBiGgvlwB+enNPlomZb/ubM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=VniAdTsPC1j4hkiQ964whJ5oVAHbTU3ZXwomszffxZWWkqWeXTvl0EmuULZL8lsWLzDo+s37Ng7+iQlbSQFS+DkNJWz6FJ/qteyc648sQeqe4d4pFAeX8YFtU1U/nQ05USKirnGJIP3TYSCMF6CTpqPGD1035ZIvxail0bR3joc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 58A4A106F; Fri, 10 May 2024 09:50:07 -0700 (PDT) Received: from donnerap.manchester.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6F42B3F6A8; Fri, 10 May 2024 09:49:40 -0700 (PDT) Date: Fri, 10 May 2024 17:49:37 +0100 From: Andre Przywara To: Javier Carrasco Cc: Yangtao Li , "Rafael J. Wysocki" , Viresh Kumar , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Jonathan Cameron , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] cpufreq: sun50i: fix memory leak in dt_has_supported_hw() Message-ID: <20240510174937.0a710104@donnerap.manchester.arm.com> In-Reply-To: <20240503-sun50i-cpufreq-nvmem-cleanup-v1-1-0a2352cac46b@gmail.com> References: <20240503-sun50i-cpufreq-nvmem-cleanup-v1-0-0a2352cac46b@gmail.com> <20240503-sun50i-cpufreq-nvmem-cleanup-v1-1-0a2352cac46b@gmail.com> Organization: ARM X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.32; aarch64-unknown-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 03 May 2024 19:52:32 +0200 Javier Carrasco wrote: Hi Javier, > The for_each_child_of_node() loop does not decrement the child node > refcount before the break instruction, even though the node is no > longer required. Ah, thanks for spotting this, there is indeed a leak. Sorry for the blunder! > This can be avoided with the new for_each_child_of_node_scoped() macro > that removes the need for any of_node_put(). Wow, that's the typical convoluted Linux macro, but it looks correct to me. It would call the put even if the loop ends naturally, but there is a NULL test in there, so that's fine. > Fixes: fa5aec9561cf ("cpufreq: sun50i: Add support for opp_supported_hw") > Signed-off-by: Javier Carrasco Reviewed-by: Andre Przywara Thanks! Andre > --- > drivers/cpufreq/sun50i-cpufreq-nvmem.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpufreq/sun50i-cpufreq-nvmem.c b/drivers/cpufreq/sun50i-cpufreq-nvmem.c > index 0b882765cd66..ef83e4bf2639 100644 > --- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c > +++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c > @@ -131,7 +131,7 @@ static const struct of_device_id cpu_opp_match_list[] = { > static bool dt_has_supported_hw(void) > { > bool has_opp_supported_hw = false; > - struct device_node *np, *opp; > + struct device_node *np; > struct device *cpu_dev; > > cpu_dev = get_cpu_device(0); > @@ -142,7 +142,7 @@ static bool dt_has_supported_hw(void) > if (!np) > return false; > > - for_each_child_of_node(np, opp) { > + for_each_child_of_node_scoped(np, opp) { > if (of_find_property(opp, "opp-supported-hw", NULL)) { > has_opp_supported_hw = true; > break; >