Re: [build bug] nf_nat_proto_sctp.c:(.text+0x6d173): undefined reference to `crc32c_le'

[David Miller <davem@davemloft.net>]

From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 21 Apr 2008 08:22:44 +0200

>   net/built-in.o: In function `sctp_manip_pkt':
>   nf_nat_proto_sctp.c:(.text+0x6d173): undefined reference to `crc32c_le'
>   nf_nat_proto_sctp.c:(.text+0x6d180): undefined reference to `crc32c_le'
>   nf_nat_proto_sctp.c:(.text+0x6d196): undefined reference to `crc32c_le'
>   nf_nat_proto_sctp.c:(.text+0x6d1c6): undefined reference to `crc32c_le'
> 
>   http://redhat.com/~mingo/misc/config-Mon_Apr_21_01_52_14_CEST_2008.bad

Thanks for your report Ingo.

Patrick, I'm not so sure how to fix this, or even what's wrong.

NF_NAT_PROTO_SCTP does a proper select on LIBCRC32C, but somehow
NF_NAT_PROTO_SCTP=y and LIBCRC32C=m.

I notice that IP_SCTP=m in this config.  So perhaps the issue is the
case where two features do a select on an infrastructure config
option.  Maybe whoever does the last 'select' gets to decide if the
option gets set to 'y' or 'm'?

It's just a guess, as I still for the life of me can't figure out
how these dependencies get sorted by the kbuild system in situations
like this.