[PATCH 1/2] perf/arm_dmc620: Fix hotplug callback leak in dmc620_pmu_init()

[shangxiaojing]

On 2022/11/15 18:53, Punit Agrawal wrote:
> Shang XiaoJing <shangxiaojing at huawei.com> writes:
> 
>> dmc620_pmu_init() won't remove the callback added by
>> cpuhp_setup_state_multi() when platform_driver_register() failed. Remove
>> the callback by cpuhp_remove_multi_state() in fail path.
>>
>> Similar to the handling of arm_ccn_init() in commit 26242b330093 ("bus:
>> arm-ccn: Prevent hotplug callback leak")
>>
>> Fixes: 53c218da220c ("driver/perf: Add PMU driver for the ARM DMC-620 memory controller")
>> Signed-off-by: Shang XiaoJing <shangxiaojing at huawei.com>
>> ---
>>   drivers/perf/arm_dmc620_pmu.c | 10 +++++++++-
>>   1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/perf/arm_dmc620_pmu.c b/drivers/perf/arm_dmc620_pmu.c
>> index 280a6ae3e27c..d07054a05861 100644
>> --- a/drivers/perf/arm_dmc620_pmu.c
>> +++ b/drivers/perf/arm_dmc620_pmu.c
>> @@ -725,6 +725,8 @@ static struct platform_driver dmc620_pmu_driver = {
>>   
>>   static int __init dmc620_pmu_init(void)
>>   {
>> +	int ret;
>> +
>>   	cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
>>   				      DMC620_DRVNAME,
>>   				      NULL,
>> @@ -732,7 +734,13 @@ static int __init dmc620_pmu_init(void)
>>   	if (cpuhp_state_num < 0)
>>   		return cpuhp_state_num;
>>   
>> -	return platform_driver_register(&dmc620_pmu_driver);
>> +	ret = platform_driver_register(&dmc620_pmu_driver);
>> +	if (ret) {
>> +		cpuhp_remove_multi_state(cpuhp_state_num);
>> +		return ret;
>> +	}
>> +
>> +	return 0;
> 
> Nit: There's no need for two separate returns. Just return "ret" at the
> bottom of the function.
> 
> With the change,
> 
> Reviewed-by: Punit Agrawal <punit.agrawal at bytedance.com>.

Will be fixed in v2.

Thanks,
-- 
Shang XiaoJing