Hi "Toke, [FYI, it's a private test report for your RFC patch.] [auto build test ERROR on bpf-next/master] url: https://github.com/0day-ci/linux/commits/Toke-H-iland-J-rgensen/bpf-Rewor... base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: powerpc-randconfig-r006-20201014 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project e7b4feea8e1bf520b34ad8c116abab6677344b74) 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 powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu # https://github.com/0day-ci/linux/commit/49323d0d5b278524de4bd9450ce2962a4... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Toke-H-iland-J-rgensen/bpf-Rework-bpf_redirect_neigh-to-allow-supplying-nexthop-from-caller/20201015-234710 git checkout 49323d0d5b278524de4bd9450ce2962a44311fec # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): __do_insb ^ arch/powerpc/include/asm/io.h:541:56: note: expanded from macro '__do_insb' #define __do_insb(p, b, n) readsb((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from net/core/filter.c:25: In file included from include/linux/sock_diag.h:5: In file included from include/linux/netlink.h:7: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:141:1: note: expanded from here __do_insw ^ arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw' #define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from net/core/filter.c:25: In file included from include/linux/sock_diag.h:5: In file included from include/linux/netlink.h:7: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:146:1: note: expanded from here __do_insl ^ arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl' #define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from net/core/filter.c:25: In file included from include/linux/sock_diag.h:5: In file included from include/linux/netlink.h:7: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:151:1: note: expanded from here __do_outsb ^ arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb' #define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from net/core/filter.c:25: In file included from include/linux/sock_diag.h:5: In file included from include/linux/netlink.h:7: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:156:1: note: expanded from here __do_outsw ^ arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw' #define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from net/core/filter.c:25: In file included from include/linux/sock_diag.h:5: In file included from include/linux/netlink.h:7: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:11: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:161:1: note: expanded from here __do_outsl ^ arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl' #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ return __bpf_redirect_neigh_v6(skb, dev, nh); ~~~~~~~~~~~~~~~~~~~~~~~ ^~ net/core/filter.c:2267:12: note: '__bpf_redirect_neigh_v6' declared here static int __bpf_redirect_neigh_v6(struct sk_buff *skb, struct net_device *dev) ^ 6 warnings and 1 error generated. vim +2404 net/core/filter.c 2385 2386 static int __bpf_redirect_neigh(struct sk_buff *skb, struct net_device *dev, 2387 struct bpf_nh_params *nh) 2388 { 2389 struct ethhdr *ethh = eth_hdr(skb); 2390 2391 if (unlikely(skb->mac_header >= skb->network_header)) 2392 goto out; 2393 bpf_push_mac_rcsum(skb); 2394 if (is_multicast_ether_addr(ethh->h_dest)) 2395 goto out; 2396 2397 skb_pull(skb, sizeof(*ethh)); 2398 skb_unset_mac_header(skb); 2399 skb_reset_network_header(skb); 2400 2401 if (skb->protocol == htons(ETH_P_IP)) 2402 return __bpf_redirect_neigh_v4(skb, dev, nh); 2403 else if (skb->protocol == htons(ETH_P_IPV6)) 2405 out: 2406 kfree_skb(skb); 2407 return -ENOTSUPP; 2408 } 2409 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org