[kbuild-all] Re: [PATCH v9 01/12] user_events: Add minimal support for trace_event into ftrace

Hi Beau, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on 85c62c8c3749eec02ba81217bdcac26867dc262e] url: https://github.com/0day-ci/linux/commits/Beau-Belgrave/user_events-Enable... base: 85c62c8c3749eec02ba81217bdcac26867dc262e config: hexagon-allmodconfig (https://download.01.org/0day-ci/archive/20220114/202201142322.DpkhCCS2-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 82c8aca93488730ce8f66101e0f3538f14b551dd) 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 # https://github.com/0day-ci/linux/commit/a5a2d34cbaeb90d281d8c13c753f4aaaa... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Beau-Belgrave/user_events-Enable-user-processes-to-create-and-write-to-trace-events/20220112-014042 git checkout a5a2d34cbaeb90d281d8c13c753f4aaaa447ec11 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/trace/ sound/soc/sof/ 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 >>): >> kernel/trace/trace_events_user.c:1027:14: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] return NULL + (*pos == 0); ~~~~ ^ 1 warning generated. vim +1027 kernel/trace/trace_events_user.c 1024 1025 static void *user_seq_start(struct seq_file *m, loff_t *pos) 1026 { > 1027 return NULL + (*pos == 0); 1028 } 1029