Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH -next] scsi: aacraid: Use memdup_user() as a cleanup
To:     "Martin K. Petersen" <martin.petersen@oracle.com>
CC:     <aacraid@microsemi.com>, <jejb@linux.ibm.com>,
        <linux-scsi@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <1587524232-118733-1-git-send-email-zou_wei@huawei.com>
 <yq1wo64bk0x.fsf@oracle.com>
From:   Samuel Zou <zou_wei@huawei.com>
Message-ID: <1a861285-8644-48d3-21c5-69c88e07db6f@huawei.com>
Date:   Sun, 26 Apr 2020 10:32:58 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101
 Thunderbird/68.7.0
MIME-Version: 1.0
In-Reply-To: <yq1wo64bk0x.fsf@oracle.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Martin,

Thanks for your review and reply.
You are right, it is not equivalent. I will keep the original goto 
cleanup. But the return value is changed to use of PTR_ERR 
(user_srbcmd), and assign it to rcode.
I will send the v2 soon later

On 2020/4/25 6:23, Martin K. Petersen wrote:
> 
> Zou,
> 
>> diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
>> index ffe41bc..1ce1620 100644
>> --- a/drivers/scsi/aacraid/commctrl.c
>> +++ b/drivers/scsi/aacraid/commctrl.c
>> @@ -513,17 +513,9 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
>>   		goto cleanup;
>>   	}
>>   
>> -	user_srbcmd = kmalloc(fibsize, GFP_KERNEL);
>> -	if (!user_srbcmd) {
>> -		dprintk((KERN_DEBUG"aacraid: Could not make a copy of the srb\n"));
>> -		rcode = -ENOMEM;
>> -		goto cleanup;
>> -	}
>> -	if(copy_from_user(user_srbcmd, user_srb,fibsize)){
>> -		dprintk((KERN_DEBUG"aacraid: Could not copy srb from user\n"));
>> -		rcode = -EFAULT;
>> -		goto cleanup;
>> -	}
>> +	user_srbcmd = memdup_user(user_srb, fibsize);
>> +	if (IS_ERR(user_srbcmd))
>> +		return PTR_ERR(user_srbcmd);
>>   
>>   	flags = user_srbcmd->flags; /* from user in cpu order */
>>   	switch (flags & (SRB_DataIn | SRB_DataOut)) {
> 
> This is not equivalent, is it? The original code does a goto cleanup;
> whereas your patch returns on error.
>