On 1/25/2017 1:51 AM, Leon Romanovsky wrote:
> On Tue, Jan 24, 2017 at 04:28:50PM -0500, Doug Ledford wrote:
>> On Sun, 2017-01-15 at 20:15 +0200, Leon Romanovsky wrote:
>>> From: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx>
>>>
>>> If IPV6 has not been enabled in the underlying kernel, we must avoid
>>> calling IPV6 procedures in rdma_cm.ko.
>>>
>>> This requires using "IS_ENABLED(CONFIG_IPV6)" in "if" statements
>>> surrounding any code which calls external IPV6 procedures.
>>
>> This seems strange....
>>
>>> In the instance fixed here, procedure cma_bind_addr() called
>>> ipv6_addr_type() -- which resulted in calling external procedure
>>> __ipv6_addr_type().
>>>
>>> Fixes: 6c26a77124ff ("RDMA/cma: fix IPv6 address resolution")
>>> Cc: <stable@xxxxxxxxxxxxxxx> # v4.2+
>>> Cc: Spencer Baugh <sbaugh@xxxxxxxxxx>
>>> Signed-off-by: Jack Morgenstein <jackm@xxxxxxxxxxxxxxxxxx>
>>> Reviewed-by: Moni Shoua <monis@xxxxxxxxxxxx>
>>> Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
>>> ---
>>> drivers/infiniband/core/cma.c | 3 ++-
>>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/infiniband/core/cma.c
>>> b/drivers/infiniband/core/cma.c
>>> index bd8d051..e19f19c 100644
>>> --- a/drivers/infiniband/core/cma.c
>>> +++ b/drivers/infiniband/core/cma.c
>>> @@ -2822,7 +2822,8 @@ static int cma_bind_addr(struct rdma_cm_id *id,
>>> struct sockaddr *src_addr,
>>> if (!src_addr || !src_addr->sa_family) {
>>> src_addr = (struct sockaddr *) &id-
>>>> route.addr.src_addr;
>>> src_addr->sa_family = dst_addr->sa_family;
>>> - if (dst_addr->sa_family == AF_INET6) {
>>
>> Why this construct? Isn't the norm to simply surround the entire if
>> statement with
>> #if IS_ENABLED(CONFIG_IPV6)
>> ...
>> #endif
>
> It is common way to add dependency on specific config option directly to
> the flow if other "if" already exists. It gives clear view on the flow,
> eliminates the need to find corresponding #endif and put all constraints
> in one place.
OK, that makes sense, I just hadn't seen it that way. I'll add this to
the -rc queue.
--
Doug Ledford <dledford@xxxxxxxxxx>
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