tree:   https://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next.git testing
head:   ce37981d9045220810dabcb9cf20a1d86202c76a
commit: 3fd2d6fdcbb7bcd1fd7110d997fb6ed6eb71dca3 [1/2] xfrm: add support for UDPv6 encapsulation of ESP
config: c6x-allyesconfig (attached as .config)
compiler: c6x-elf-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout 3fd2d6fdcbb7bcd1fd7110d997fb6ed6eb71dca3
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day GCC_VERSION=9.3.0 make.cross ARCH=c6x 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   net/ipv6/esp6.c: In function 'esp_output_encap_csum':
>> net/ipv6/esp6.c:144:15: error: implicit declaration of function 'csum_ipv6_magic'; did you mean 'csum_tcpudp_magic'? [-Werror=implicit-function-declaration]
     144 |   uh->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
         |               ^~~~~~~~~~~~~~~
         |               csum_tcpudp_magic
   cc1: some warnings being treated as errors

vim +144 net/ipv6/esp6.c

   133	
   134	static void esp_output_encap_csum(struct sk_buff *skb)
   135	{
   136		/* UDP encap with IPv6 requires a valid checksum */
   137		if (*skb_mac_header(skb) == IPPROTO_UDP) {
   138			struct udphdr *uh = udp_hdr(skb);
   139			struct ipv6hdr *ip6h = ipv6_hdr(skb);
   140			int len = ntohs(uh->len);
   141			unsigned int offset = skb_transport_offset(skb);
   142			__wsum csum = skb_checksum(skb, offset, skb->len - offset, 0);
   143	
 > 144			uh->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
   145						    len, IPPROTO_UDP, csum);
   146			if (uh->check == 0)
   147				uh->check = CSUM_MANGLED_0;
   148		}
   149	}
   150	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org