Re: [PATCH] x86/platform/intel/iosf_mbi: Fix error handling in iosf_mbi_init()

[Yuan Can <yuancan@huawei.com>]

在 2022/11/15 16:26, Andy Shevchenko 写道:
> On Tue, Nov 15, 2022 at 9:38 AM Yuan Can <yuancan@huawei.com> wrote:
>> A problem about modprobe iosf_mbi failed is triggered with the following
>> log given:
>>
>>   debugfs: Directory 'iosf_sb' with parent '/' already present!
>>
>> The reason is that iosf_mbi_init() returns pci_register_driver()
>> directly without checking its return value, if pci_register_driver()
>> failed, it returns without removing debugfs, resulting the debugfs of
>> iosf_sb can never be created later.
>>
>>   iosf_mbi_init()
>>     iosf_mbi_dbg_init() # create debugfs
>>     pci_register_driver()
>>       driver_register()
>>         bus_add_driver()
>>           priv = kzalloc(...) # OOM happened
>>     # return without remove debugfs and destroy workqueue
>>
>> Fix by remove debugfs and iosf_mbi_pm_qos when pci_register_driver()
> removing
>
>> returns error.
>>   static int __init iosf_mbi_init(void)
>>   {
>> +       int ret;
>> +
>>          iosf_debugfs_init();
>>
>>          cpu_latency_qos_add_request(&iosf_mbi_pm_qos, PM_QOS_DEFAULT_VALUE);
>>
>> -       return pci_register_driver(&iosf_mbi_pci_driver);
>> +       ret = pci_register_driver(&iosf_mbi_pci_driver);
>> +       if (ret) {
>> +               cpu_latency_qos_remove_request(&iosf_mbi_pm_qos);
>> +               iosf_debugfs_remove();
>> +       }
>> +
>> +       return ret;
>>   }
> Can we rewrite it as
>
>    if (ret)
>      goto err_remove;
>
>    return 0;
>
> err_remove:
>    ...
>    return ret;
>
> ?
Thanks for these suggestions! will be changed in the next version.

-- 
Best regards,
Yuan Can