[PATCH] clocksource: cadence_ttc: fix memory leak in ttc_setup_clockevent

[PATCH] clocksource: cadence_ttc: fix memory leak in ttc_setup_clockevent

[Yue Haibing]

From: YueHaibing <yuehaibing@huawei.com>

Add the missing kfree() in ttc_setup_clockevent() to free the
mem before error return.

Fixes: 70504f311d4b ("clocksource/drivers/cadence_ttc: Convert init function to return error")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
 drivers/clocksource/timer-cadence-ttc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/clocksource/timer-cadence-ttc.c b/drivers/clocksource/timer-cadence-ttc.c
index b334029..b664af8 100644
--- a/drivers/clocksource/timer-cadence-ttc.c
+++ b/drivers/clocksource/timer-cadence-ttc.c
@@ -432,6 +432,7 @@ static int __init ttc_setup_clockevent(struct clk *clk,
 				    &ttcce->ttc.clk_rate_change_nb);
 	if (err) {
 		pr_warn("Unable to register clock notifier.\n");
+		kfree(ttcce);
 		return err;
 	}
 
-- 
2.7.0

Re: [PATCH] clocksource: cadence_ttc: fix memory leak in ttc_setup_clockevent

[Daniel Lezcano]

Hi Yue,

I appreciate the fix but usually we add a rollback for all the
operations done in the init function.

Please, migrate the init function to the timer-of API, so the rollback
will be automatically handled.

Example here:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/timer-sprd.c#n197

On 09/03/2019 14:19, Yue Haibing wrote:
> From: YueHaibing <yuehaibing@huawei.com>
> 
> Add the missing kfree() in ttc_setup_clockevent() to free the
> mem before error return.
> 
> Fixes: 70504f311d4b ("clocksource/drivers/cadence_ttc: Convert init function to return error")
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> ---
>  drivers/clocksource/timer-cadence-ttc.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/clocksource/timer-cadence-ttc.c b/drivers/clocksource/timer-cadence-ttc.c
> index b334029..b664af8 100644
> --- a/drivers/clocksource/timer-cadence-ttc.c
> +++ b/drivers/clocksource/timer-cadence-ttc.c
> @@ -432,6 +432,7 @@ static int __init ttc_setup_clockevent(struct clk *clk,
>  				    &ttcce->ttc.clk_rate_change_nb);
>  	if (err) {
>  		pr_warn("Unable to register clock notifier.\n");
> +		kfree(ttcce);
>  		return err;
>  	}
>  
> 


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Re: [PATCH] clocksource: cadence_ttc: fix memory leak in ttc_setup_clockevent

[YueHaibing]

On 2019/3/9 22:24, Daniel Lezcano wrote:
> 
> Hi Yue,
> 
> I appreciate the fix but usually we add a rollback for all the
> operations done in the init function.
> 
> Please, migrate the init function to the timer-of API, so the rollback
> will be automatically handled.
> 
> Example here:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/timer-sprd.c#n197

It seems complicated for me,

ttc_setup_clocksource and ttc_setup_clockevent use a different of_clk,
hard to use timer_of_init to do a initialization.

I'm not familiar with this. Maybe someone else can do this?

> 
> On 09/03/2019 14:19, Yue Haibing wrote:
>> From: YueHaibing <yuehaibing@huawei.com>
>>
>> Add the missing kfree() in ttc_setup_clockevent() to free the
>> mem before error return.
>>
>> Fixes: 70504f311d4b ("clocksource/drivers/cadence_ttc: Convert init function to return error")
>> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>> ---
>>  drivers/clocksource/timer-cadence-ttc.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/clocksource/timer-cadence-ttc.c b/drivers/clocksource/timer-cadence-ttc.c
>> index b334029..b664af8 100644
>> --- a/drivers/clocksource/timer-cadence-ttc.c
>> +++ b/drivers/clocksource/timer-cadence-ttc.c
>> @@ -432,6 +432,7 @@ static int __init ttc_setup_clockevent(struct clk *clk,
>>  				    &ttcce->ttc.clk_rate_change_nb);
>>  	if (err) {
>>  		pr_warn("Unable to register clock notifier.\n");
>> +		kfree(ttcce);
>>  		return err;
>>  	}
>>  
>>
> 
> 

Re: [PATCH] clocksource: cadence_ttc: fix memory leak in ttc_setup_clockevent

[Michal Simek]

On 09. 03. 19 15:24, Daniel Lezcano wrote:
> 
> Hi Yue,
> 
> I appreciate the fix but usually we add a rollback for all the
> operations done in the init function.
> 
> Please, migrate the init function to the timer-of API, so the rollback
> will be automatically handled.
> 
> Example here:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clocksource/timer-sprd.c#n197

I have put a record to Xilinx database to take a look at it when we have
time.

Thanks,
Michal