Hi Jesper,

I love your patch! Perhaps something to improve:

[auto build test WARNING on bpf-next/master]

url:    https://github.com/0day-ci/linux/commits/Jesper-Dangaard-Brouer/bpf-New-approach-for-BPF-MTU-handling/20210201-185654
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: x86_64-randconfig-r014-20210201 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 275c6af7d7f1ed63a03d05b4484413e447133269)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/8d1404896e0346004412f5ffd64ef92ac578e5de
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jesper-Dangaard-Brouer/bpf-New-approach-for-BPF-MTU-handling/20210201-185654
        git checkout 8d1404896e0346004412f5ffd64ef92ac578e5de
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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

All warnings (new ones prefixed by >>):

>> net/core/dev.c:2201:5: warning: no previous prototype for function '__dev_forward_skb2' [-Wmissing-prototypes]
   int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
       ^
   net/core/dev.c:2201:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
   ^
   static 
   net/core/dev.c:4937:1: warning: unused function 'sch_handle_ingress' [-Wunused-function]
   sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
   ^
   net/core/dev.c:5086:19: warning: unused function 'nf_ingress' [-Wunused-function]
   static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
                     ^
   3 warnings generated.


vim +/__dev_forward_skb2 +2201 net/core/dev.c

  2200	
> 2201	int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
  2202			     bool check_mtu)
  2203	{
  2204		int ret = ____dev_forward_skb(dev, skb, check_mtu);
  2205	
  2206		if (likely(!ret)) {
  2207			skb->protocol = eth_type_trans(skb, dev);
  2208			skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
  2209		}
  2210	
  2211		return ret;
  2212	}
  2213	

---
0-DAY CI Kernel Test Service, Intel Corporation
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