Re: [PATCH] crypto: hisilicon - fix strncpy warning with strlcpy

[Zhangfei Gao <zhangfei.gao@linaro.org>]

On 2020/6/4 下午2:18, Herbert Xu wrote:
> On Thu, Jun 04, 2020 at 02:10:37PM +0800, Zhangfei Gao wrote:
>>> 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
> That's not what I meant.  As it is if you do exceed the limit the
> name is silently truncated.  Wouldn't it be better to fail the
> allocation instead?
I think it is fine.
1. Currently the name size is 64, bigger enough.
Simply grep in driver name, 64 should be enough.
We can make it larger when there is a request.
2. it does not matter what the name is, since it is just an interface.
cat /sys/class/uacce/hisi_zip-0/flags
cat /sys/class/uacce/his-0/flags
should be both fine to app only they can be distinguished.
3. It maybe a hard restriction to fail just because of a long name.

What do you think.

Thanks