Re: linux-next: build failure after merge of the net-next tree

[Heiko Carstens]

On Wed, Aug 05, 2020 at 03:06:27PM +0200, Stefano Brivio wrote:
> On Wed, 5 Aug 2020 22:31:21 +1000
> Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> 
> > Hi all,
> > 
> > After merging the net-next tree, today's linux-next build (s390 defconfig)
> > failed like this:
> > 
> > net/ipv4/ip_tunnel_core.c:335:2: error: implicit declaration of function 'csum_ipv6_magic' [-Werror=implicit-function-declaration]
> > 
> > Caused by commit
> > 
> >   4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets")
> 
> Ouch, sorry for that.
> 
> I'm getting a few of them by the way:
> 
> ---
> net/core/skbuff.o: In function `skb_checksum_setup_ipv6':
> /home/sbrivio/net-next/net/core/skbuff.c:4980: undefined reference to `csum_ipv6_magic'
> net/core/netpoll.o: In function `netpoll_send_udp':
> /home/sbrivio/net-next/net/core/netpoll.c:419: undefined reference to `csum_ipv6_magic'
> net/netfilter/utils.o: In function `nf_ip6_checksum':
> /home/sbrivio/net-next/net/netfilter/utils.c:74: undefined reference to `csum_ipv6_magic'
> /home/sbrivio/net-next/net/netfilter/utils.c:84: undefined reference to `csum_ipv6_magic'
> net/netfilter/utils.o: In function `nf_ip6_checksum_partial':
> /home/sbrivio/net-next/net/netfilter/utils.c:112: undefined reference to `csum_ipv6_magic'
> net/ipv4/ip_tunnel_core.o:/home/sbrivio/net-next/net/ipv4/ip_tunnel_core.c:335: more undefined references to `csum_ipv6_magic' follow
> ---
> 
> ...checking how it should be fixed now.
> 
> Heiko, by the way, do we want to provide a s390 version similar to the
> existing csum_partial() implementation in
> arch/s390/include/asm/checksum.h right away? Otherwise, I'll just take
> care of the ifdeffery.

You probably only need to include include/net/ip6_checksum.h which
contains the default implementation.

And yes, I put it on my todo list that we need to provide an s390
variant as well.