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Subject: Re: [PATCH 05/12] net/hns3: fix an unreasonable memset
To: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>, <dev@dpdk.org>
CC: <ferruh.yigit@intel.com>, <thomas@monjalon.net>
References: <20220519122917.2334-1-humin29@huawei.com>
 <20220519122917.2334-6-humin29@huawei.com>
 <1c148094-3550-b78e-7c23-1819582a83ff@oktetlabs.ru>
From: "Min Hu (Connor)" <humin29@huawei.com>
Message-ID: <19acdf78-af14-25fa-a52b-8b1f96d3fcb3@huawei.com>
Date: Fri, 20 May 2022 16:37:08 +0800
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Hi, Andrew ,

在 2022/5/20 15:58, Andrew Rybchenko 写道:
> On 5/19/22 15:29, Min Hu (Connor) wrote:
>> From: Huisong Li <lihuisong@huawei.com>
>>
>> This patch fixes an unreasonable memset.
>>
>> Fixes: bba636698316 ("net/hns3: support Rx/Tx and related operations")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
>> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
>> ---
>>   drivers/net/hns3/hns3_rxtx.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/hns3/hns3_rxtx.c b/drivers/net/hns3/hns3_rxtx.c
>> index 510802be05..5a2cfe5a54 100644
>> --- a/drivers/net/hns3/hns3_rxtx.c
>> +++ b/drivers/net/hns3/hns3_rxtx.c
>> @@ -776,7 +776,7 @@ hns3vf_reset_all_tqps(struct hns3_hw *hw)
>>       int ret;
>>       uint16_t i;
>> -    memset(msg_data, 0, sizeof(uint16_t));
>> +    memset(msg_data, 0, sizeof(msg_data));
> 
> It looks a bit suspicious. May be it is better to do:
>      memset(&msg_data, 0, sizeof(msg_data));
I think this is too hard to understand for &msg_data is **p.
maybe it confuse others when use memset to operate level-2 pointer.


> It is pretty common mistake to do:
>      memset(p, 0, sizeof(p));
> instead of
>      memset(p, 0, sizeof(*p));
> when p is a pointer.
> I realize that msg_data is an array in this case, but
> I think it is better to avoid bad pattern in the code.
> 
>>       ret = hns3_send_mbx_msg(hw, HNS3_MBX_QUEUE_RESET, 0, msg_data,
>>                   sizeof(msg_data), true, &reset_status,
>>                   sizeof(reset_status));
> 
> .