Re: [PATCH] dev_ioctl should return -EINVAL for unknown ioctl instead of -ENOTTY

[Wang Sheng-Hui <shhuiw@gmail.com>]

On 2011年09月01日 23:41, Ben Hutchings wrote:
> On Thu, 2011-09-01 at 22:52 +0800, Wang Sheng-Hui wrote:
>> The patch is against 3.1-rc3.
>>
>> Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
>> ---
>>  net/core/dev.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/net/core/dev.c b/net/core/dev.c
>> index 17d67b5..de6033c 100644
>> --- a/net/core/dev.c
>> +++ b/net/core/dev.c
>> @@ -5092,7 +5092,7 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
>>  		/* Take care of Wireless Extensions */
>>  		if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
>>  			return wext_handle_ioctl(net, &ifr, cmd, arg);
>> -		return -ENOTTY;
>> +		return -EINVAL;
>>  	}
>>  }
>>  
> 
> Whereas, Linus Torvalds wrote in
> <BANLkTin=PTbTwBR2s+owMLy+GmKigeoYvg@mail.gmail.com>:
> [...]
>> The correct error code for "I don't understand this ioctl" is ENOTTY.
>> The naming may be odd, but you should think of that error value as a
>> "unrecognized ioctl number, you're feeding me random numbers that I
>> don't understand and I assume for historical reasons that you tried to
>> do some tty operation on me".
> [...]
> 
> (Not that we are consistent about using ENOTTY in networking now.)
> 
> Ben.
> 

Got it. Thanks.