tree: https://github.com/esmil/linux visionfive-5.16.y head: eeeb46a916e77aecbe1699537a5592746f3130f6 commit: 6348ed9f5269d38acf552123e96766aa2eb0fd7e [22/80] riscv: optimized memset config: riscv-randconfig-c006-20220118 (https://download.01.org/0day-ci/archive/20220119/202201190447.MTj18zPA-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c10cbb243cafc0cf42c3e922cb29183279444432) 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 riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://github.com/esmil/linux/commit/6348ed9f5269d38acf552123e96766aa2eb... git remote add esmil https://github.com/esmil/linux git fetch --no-tags esmil visionfive-5.16.y git checkout 6348ed9f5269d38acf552123e96766aa2eb0fd7e # 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=riscv SHELL=/bin/bash mm/kasan/ 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 >>): void *memset(void *addr, int c, size_t len) ^ mm/kasan/shadow.c:42:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void *memset(void *addr, int c, size_t len) ^ static mm/kasan/shadow.c:63:7: warning: no previous prototype for function 'memcpy' [-Wmissing-prototypes] void *memcpy(void *dest, const void *src, size_t len) ^ mm/kasan/shadow.c:63:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void *memcpy(void *dest, const void *src, size_t len) ^ static 2 warnings generated. vim +/memset +42 mm/kasan/shadow.c bb359dbcb70085 Andrey Konovalov 2020-12-22 40 bb359dbcb70085 Andrey Konovalov 2020-12-22 41 #undef memset bb359dbcb70085 Andrey Konovalov 2020-12-22 @42 void *memset(void *addr, int c, size_t len) bb359dbcb70085 Andrey Konovalov 2020-12-22 43 { f00748bfa0246c Andrey Konovalov 2021-02-24 44 if (!kasan_check_range((unsigned long)addr, len, true, _RET_IP_)) bb359dbcb70085 Andrey Konovalov 2020-12-22 45 return NULL; bb359dbcb70085 Andrey Konovalov 2020-12-22 46 bb359dbcb70085 Andrey Konovalov 2020-12-22 47 return __memset(addr, c, len); bb359dbcb70085 Andrey Konovalov 2020-12-22 48 } bb359dbcb70085 Andrey Konovalov 2020-12-22 49 :::::: The code at line 42 was first introduced by commit :::::: bb359dbcb70085a63e8bdbf14837a900750f0cf7 kasan: split out shadow.c from common.c :::::: TO: Andrey Konovalov <andreyknvl(a)google.com&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org