Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Received-SPF: Pass (protection.outlook.com: domain of xilinx.com designates
 149.199.60.83 as permitted sender) receiver=protection.outlook.com;
 client-ip=149.199.60.83; helo=xsj-pvapsmtpgw01;
Subject: Re: [PATCH] clocksource/drivers: Fix memory leaks in
 ttc_setup_clockevent and ttc_setup_clocksource
To:     Johan Hovold <johan@kernel.org>,
        Navid Emamdoost <navid.emamdoost@gmail.com>
Cc:     Michal Simek <michal.simek@xilinx.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        =?UTF-8?Q?S=c3=b6ren_Brinkmann?= <soren.brinkmann@xilinx.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        emamd001@umn.edu
References: <20191220000923.9924-1-navid.emamdoost@gmail.com>
 <20191220051013.GT22665@localhost>
From:   Michal Simek <michal.simek@xilinx.com>
Message-ID: <3d72fe70-25fb-cdee-ac7d-bc1aa2ae5137@xilinx.com>
Date:   Fri, 20 Dec 2019 09:37:44 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.2.2
MIME-Version: 1.0
In-Reply-To: <20191220051013.GT22665@localhost>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Dec 2019 08:38:03.8072
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: e6d9d3bd-ed15-4516-fdda-08d78527ee05
X-MS-Exchange-CrossTenant-Id: 657af505-d5df-48d0-8300-c31994686c5c
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=657af505-d5df-48d0-8300-c31994686c5c;Ip=[149.199.60.83];Helo=[xsj-pvapsmtpgw01]
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR02MB5790
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 20. 12. 19 6:10, Johan Hovold wrote:
> On Thu, Dec 19, 2019 at 06:09:21PM -0600, Navid Emamdoost wrote:
>> In the implementation of ttc_setup_clockevent() and
>> ttc_setup_clocksource(), the allocated memory for ttccs is leaked when
>> clk_notifier_register() fails. Use goto to direct the execution into error
>> handling path.
> 
> No, that memory was never leaked since that function did not return on
> registration errors before your patch.
> 
>> Fixes: 70504f311d4b ("clocksource/drivers/cadence_ttc: Convert init function to return error")
> 
> Perhaps you meant to fix the actual leak that was added by this commit
> in a different function, ttc_setup_clockevent(), when returning on
> notifier-registration errors?
> 
> Also should the clock be left enabled on errors?
> 
>> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
>> ---
>>  drivers/clocksource/timer-cadence-ttc.c | 22 +++++++++++++---------
>>  1 file changed, 13 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/clocksource/timer-cadence-ttc.c b/drivers/clocksource/timer-cadence-ttc.c
>> index c6d11a1cb238..46d69982ad33 100644
>> --- a/drivers/clocksource/timer-cadence-ttc.c
>> +++ b/drivers/clocksource/timer-cadence-ttc.c
>> @@ -328,10 +328,8 @@ static int __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
>>  	ttccs->ttc.clk = clk;
>>  
>>  	err = clk_prepare_enable(ttccs->ttc.clk);
>> -	if (err) {
>> -		kfree(ttccs);
>> -		return err;
>> -	}
>> +	if (err)
>> +		goto release_ttcce;
>>  
>>  	ttccs->ttc.freq = clk_get_rate(ttccs->ttc.clk);
>>  
>> @@ -341,8 +339,10 @@ static int __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
>>  
>>  	err = clk_notifier_register(ttccs->ttc.clk,
>>  				    &ttccs->ttc.clk_rate_change_nb);
>> -	if (err)
>> +	if (err) {
>>  		pr_warn("Unable to register clock notifier.\n");
>> +		goto release_ttcce;
>> +	}
> 

+ this is IMHO v3 version. It means just label it properly and also keep
changes log.

Thanks,
Michal