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Subject: Re: [PATCH] wifi: ath10k: Fix resource leak in ath10k_pci_init()
From:   xiujianfeng <xiujianfeng@huawei.com>
To:     Jeff Johnson <quic_jjohnson@quicinc.com>, <kvalo@kernel.org>,
        <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <pabeni@redhat.com>, <rmani@qti.qualcomm.com>
CC:     <ath10k@lists.infradead.org>, <linux-wireless@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20221108133858.53308-1-xiujianfeng@huawei.com>
 <4e81efea-23f1-e52c-b0b4-abf445ed5f15@quicinc.com>
 <cd3194f8-3cad-ce12-602f-8651e99365ab@huawei.com>
Message-ID: <fc6076c9-d61d-f404-61c1-d8df01ab93b9@huawei.com>
Date:   Thu, 10 Nov 2022 10:54:10 +0800
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Hi,

在 2022/11/10 9:54, xiujianfeng 写道:
> Hi,
> 
> 在 2022/11/10 0:34, Jeff Johnson 写道:
>> On 11/8/2022 5:38 AM, Xiu Jianfeng wrote:
>>> When ath10k_ahb_init() fails, it does not unregister ath10k_pci_driver,
>>> which will cause a resource leak issue, call pci_unregister_driver() in
>>> the error path to fix this issue.
>>>
>>> Fixes: 0b523ced9a3c ("ath10k: add basic skeleton to support ahb")
>>> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
>>> ---
>>>   drivers/net/wireless/ath/ath10k/pci.c | 4 +++-
>>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/wireless/ath/ath10k/pci.c 
>>> b/drivers/net/wireless/ath/ath10k/pci.c
>>> index e56c6a6b1379..22f8f8b20762 100644
>>> --- a/drivers/net/wireless/ath/ath10k/pci.c
>>> +++ b/drivers/net/wireless/ath/ath10k/pci.c
>>> @@ -3800,8 +3800,10 @@ static int __init ath10k_pci_init(void)
>>>                  ret);
>>>       ret = ath10k_ahb_init();
>>> -    if (ret)
>>> +    if (ret) {
>>>           printk(KERN_ERR "ahb init failed: %d\n", ret);
>>> +        pci_unregister_driver(&ath10k_pci_driver);
>>> +    }
>>>       return ret;
>>>   }
>>
>> imo neither the existing code nor the modified code is correct.
>>
>> the driver is attempting to register to support two different buses.
>>
>> if either of these is successful then ath10k_pci_init() should return 
>> 0 so that hardware attached to the successful bus can be probed and 
>> supported.
>>
>> only if both of these are unsuccessful should ath10k_pci_init() return 
>> an errno.
>>
>> so I suggest
>>      int ret1, ret2;
>>
>>      ret1 = pci_register_driver(&ath10k_pci_driver);
>>      if (ret1)
>>          printk(KERN_ERR "failed to register ath10k pci driver: %d\n",
>>                 ret1);
>>
>>      ret2 = ath10k_ahb_init();
>>      if (ret2)
>>          printk(KERN_ERR "ahb init failed: %d\n", ret2);
>>
>>      if (ret1 && ret2)
>>          return ret1;
>>
>>      /* registered to at least one bus */
>>      return 0;
>> }
> 
> Thanks, this is better. however, if pci_register_driver() returns 0
> while ath10k_ahb_init() returns error, it's better to unregister the
> first bus, here is my another proposal:
> 
>         int ret;
> 
>         ret = pci_register_driver(&ath10k_pci_driver);
>         if (ret) {
>                 printk(KERN_ERR "failed to register ath10k pci driver: 
> %d\n",
>                        ret);
>                 return ret;
>         }
> 
>         ret = ath10k_ahb_init();
>         if (ret) {
>                 printk(KERN_ERR "ahb init failed: %d\n", ret);
>                 pci_unregister_driver(&ath10k_pci_driver);
>                 return ret;
>         }
> 
>         return 0;
> 
> If you agree, I will send v2 with this.
> 

Sorry, I misunderstood, I will send v2 according to your suggestion.

>>
>> .
> 
> .