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

On Wed, Aug 05, 2020 at 03:06:27PM +0200, Stefano Brivio wrote:

On Wed, 5 Aug 2020 22:31:21 +1000
Stephen Rothwell [off-list ref] wrote:

quoted

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.