On 06/05/2014 08:55 AM, David Laight wrote:
> From: Toshiaki Makita
>> (2014/06/05 20:03), David Laight wrote:
>>> From: Toshiaki Makita
>>>> br_manage_promisc() incorrectly expects br_auto_port() to return only 0
>>>> or 1, while it actually returns flags, i.e., a subset of BR_AUTO_MASK.
>>>>
>>>> Signed-off-by: Toshiaki Makita <makita.toshi...@lab.ntt.co.jp>
>>>> ---
>>>> net/bridge/br_if.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
>>>> index a08d2b8..6a07a40 100644
>>>> --- a/net/bridge/br_if.c
>>>> +++ b/net/bridge/br_if.c
>>>> @@ -153,7 +153,7 @@ void br_manage_promisc(struct net_bridge *br)
>>>> * This lets us disable promiscuous mode and write
>>>> * this config to hw.
>>>> */
>>>> - if (br->auto_cnt <= br_auto_port(p))
>>>> + if (br->auto_cnt <= !!br_auto_port(p))
>>>> br_port_clear_promisc(p);
>>>> else
>>>> br_port_set_promisc(p);
>>>
>>> Why not the less confusing:
>>> if (br->auto_cnt || br_auto_port(p))
>>> and reverse the then/else lines?
>>
>> I'm respecting the original style, but I'm not particular about this style.
>> I'll make less confusing one, thanks :)
>>
>> (Your suggested condition is not exactly the same as current one, even
>> if reversing if/else. v2 will be different than it. Anyway, thanks.)
>
> A quick truth table:
> auto_cnt auto_port set/clear
> 0 0 clear
> 0 1 clear
Can't happen
> 1 0 set
Can't happen
> 1 1 clear
> 2+ 0/1 clear
>
> So you want:
> if (br->auto_cnt && !br_auto_port(p))
> br_port_set_promisc(p);
> else
> br_port_clear_promisc(p);
Some versions of the series that added this had
an explicit check for count. Essentially, the
expanded condition is this:
if (count == 0)
clear
else if (count == 1 && auto_port(p))
clear
else
set
The suggestion was that we could use a boolean (0|1)
to check reduce the above to
if (count <= auto_port(p))
clear
else
set
Personally, I prefer the extended version since it
is much clearer and is easy to understand.
-vlad
>
> Does seem like a strange condition.
>
> David
>
>
>
>
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