Hi Simon, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on net-next/master] url: https://github.com/0day-ci/linux/commits/Simon-Horman/flow_offload-hardwa... base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git c2255ff47768c94a0ebc3968f007928bb47ea43b config: powerpc-randconfig-r016-20210722 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9625ca5b602616b2f5584e8a49ba93c52c141e40) 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/9228a8efdbf7a736354b87c0db3260dd7... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Simon-Horman/flow_offload-hardware-offload-of-TC-actions/20210722-172229 git checkout 9228a8efdbf7a736354b87c0db3260dd7d2c4abd # 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 warnings (new ones prefixed by >>): In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:619: arch/powerpc/include/asm/io-defs.h:43:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insb, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:616:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:238:1: note: expanded from here __do_insb ^ arch/powerpc/include/asm/io.h:556:56: 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/sched/act_api.c:13: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:619: 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:616:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:2:1: note: expanded from here __do_insw ^ arch/powerpc/include/asm/io.h:557:56: 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/sched/act_api.c:13: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:619: 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:616:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:4:1: note: expanded from here __do_insl ^ arch/powerpc/include/asm/io.h:558:56: 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/sched/act_api.c:13: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:619: 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:616:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:6:1: note: expanded from here __do_outsb ^ arch/powerpc/include/asm/io.h:559:58: 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/sched/act_api.c:13: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:619: 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:616:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:8:1: note: expanded from here __do_outsw ^ arch/powerpc/include/asm/io.h:560:58: 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/sched/act_api.c:13: In file included from include/linux/skbuff.h:31: In file included from include/linux/dma-mapping.h:10: In file included from include/linux/scatterlist.h:9: In file included from arch/powerpc/include/asm/io.h:619: 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:616:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:10:1: note: expanded from here __do_outsl ^ arch/powerpc/include/asm/io.h:561:58: note: expanded from macro '__do_outsl' #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ int tcf_action_offload_cmd(struct tc_action *actions[], ^ net/sched/act_api.c:1064:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int tcf_action_offload_cmd(struct tc_action *actions[], ^ static 13 warnings generated. vim +/tcf_action_offload_cmd +1064 net/sched/act_api.c 1062 1063 /* offload the tc command after inserted */ 1065 struct netlink_ext_ack *extack) 1066 { 1067 struct flow_offload_action *fl_act; 1068 int err = 0; 1069 1070 fl_act = flow_action_alloc(tcf_act_num_actions(actions)); 1071 if (!fl_act) 1072 return -ENOMEM; 1073 1074 fl_act->extack = extack; 1075 err = tc_setup_action(&fl_act->action, actions); 1076 if (err) { 1077 NL_SET_ERR_MSG_MOD(extack, 1078 "Failed to setup tc actions for offload\n"); 1079 goto err_out; 1080 } 1081 fl_act->command = FLOW_ACT_REPLACE; 1082 1083 flow_indr_dev_setup_offload(NULL, NULL, TC_SETUP_ACT, fl_act, NULL, NULL); 1084 1085 tc_cleanup_flow_action(&fl_act->action); 1086 1087 err_out: 1088 kfree(fl_act); 1089 return err; 1090 } 1091 EXPORT_SYMBOL(tcf_action_offload_cmd); 1092 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org