Subject: Re: [PATCH net-next v3] af_mpls: fix undefined reference to ip6_route_output

From: roopa <[email-masked]>
Date: Mon, 27 Jul 2015 21:30:31 -0700

On 7/27/15, 9:20 PM, David Miller wrote:
> From: Roopa Prabhu <[email-masked]>
> Date: Mon, 27 Jul 2015 17:41:17 -0700
>
>> @@ -33,4 +33,11 @@ config MPLS_IPTUNNEL
>>   	---help---
>>   	 mpls ip tunnel support.
>>   
>> +config MPLS_NEXTHOP_DEVLOOKUP
>> +	bool "MPLS: nexthop oif dev lookup"
>> +	depends on MPLS_ROUTING && INET && (IPV6 || IPV6=n)
>> +	---help---
>> +	 This enables mpls route nexthop dev lookup when oif is not
>> +	 specified by user
>
> This still allows the illegal combination, how did you test this?
>
> CONFIG_IPV6=m
> CONFIG_MPLS=y
> CONFIG_NET_MPLS_GSO=y
> CONFIG_MPLS_ROUTING=y
> CONFIG_MPLS_IPTUNNEL=y
> CONFIG_MPLS_NEXTHOP_DEVLOOKUP=y
>
> net/built-in.o: In function `find_outdev':
> af_mpls.c:(.text+0x17df41): undefined reference to `ip6_route_output'
>
> The situation that must be prevented is MPLS_ROUTING=y + IPV6=m,
> but that's exactly what is being allowed even after your patch.
>
> Again, how did you test this?  Did you try the case that causes
> problems as indicated in the failure reports?
yes, I did test exactly the combination above. And also CONFIG_IPV6=m + 
CONFIG_MPLS_ROUTING=m and others with CONFIG_IPV6=n. Am not sure how I 
missed the error.... I will look again. Sorry about the iteration.