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Subject: Re: [PATCH] crypto: hisilicon - fix strncpy warning with strlcpy
To:     Herbert Xu <herbert@gondor.apana.org.au>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        wangzhou1 <wangzhou1@hisilicon.com>,
        linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
        kbuild-all@lists.01.org
References: <202006032110.BEbKqovX%lkp@intel.com>
 <1591241524-6452-1-git-send-email-zhangfei.gao@linaro.org>
 <20200604033918.GA2286@gondor.apana.org.au>
From:   Zhangfei Gao <zhangfei.gao@linaro.org>
Message-ID: <b6ad8af2-1cb7-faac-0446-5e09e97f3616@linaro.org>
Date:   Thu, 4 Jun 2020 14:10:37 +0800
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On 2020/6/4 上午11:39, Herbert Xu wrote:
> On Thu, Jun 04, 2020 at 11:32:04AM +0800, Zhangfei Gao wrote:
>> Use strlcpy to fix the warning
>> warning: 'strncpy' specified bound 64 equals destination size
>>           [-Wstringop-truncation]
>>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
>> ---
>>   drivers/crypto/hisilicon/qm.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c
>> index f795fb5..224f3e2 100644
>> --- a/drivers/crypto/hisilicon/qm.c
>> +++ b/drivers/crypto/hisilicon/qm.c
>> @@ -1574,7 +1574,7 @@ static int qm_alloc_uacce(struct hisi_qm *qm)
>>   		.ops = &uacce_qm_ops,
>>   	};
>>   
>> -	strncpy(interface.name, pdev->driver->name, sizeof(interface.name));
>> +	strlcpy(interface.name, pdev->driver->name, sizeof(interface.name));
> Should this even allow truncation? Perhaps it'd be better to fail
> in case of an overrun?
I think we do not need consider overrun, since it at most copy size-1 
bytes to dest.
 From the manual: strlcpy()
        This  function  is  similar  to  strncpy(), but it copies at 
most size-1 bytes to dest, always adds a terminating null
        byte,
And simple tested with smaller SIZE of interface.name,  only SIZE-1 is 
copied, so it is safe.
-#define UACCE_MAX_NAME_SIZE    64
+#define UACCE_MAX_NAME_SIZE    4

Thanks