tree: https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git fexit_fix head: e46400d7622f4edb317ba695149fbc7274dd27ee commit: fd1505d85b75947eab995138a46264efadecfc17 [1/2] ftrace: Fix modify_ftrace_direct. config: x86_64-randconfig-a002-20210318 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project fcc1ce00931751ac02498986feb37744e9ace8de) 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://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git/commit/?id=fd... git remote add ast https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git git fetch --no-tags ast fexit_fix git checkout fd1505d85b75947eab995138a46264efadecfc17 # 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(a)intel.com&gt; All warnings (new ones prefixed by >>): kernel/trace/ftrace.c:302:5: warning: no previous prototype for function '__register_ftrace_function' [-Wmissing-prototypes] int __register_ftrace_function(struct ftrace_ops *ops) ^ kernel/trace/ftrace.c:302:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int __register_ftrace_function(struct ftrace_ops *ops) ^ static kernel/trace/ftrace.c:345:5: warning: no previous prototype for function '__unregister_ftrace_function' [-Wmissing-prototypes] int __unregister_ftrace_function(struct ftrace_ops *ops) ^ kernel/trace/ftrace.c:345:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int __unregister_ftrace_function(struct ftrace_ops *ops) ^ static kernel/trace/ftrace.c:584:5: warning: no previous prototype for function 'ftrace_profile_pages_init' [-Wmissing-prototypes] int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) ^ kernel/trace/ftrace.c:584:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) ^ static kernel/trace/ftrace.c:3876:15: warning: no previous prototype for function 'arch_ftrace_match_adjust' [-Wmissing-prototypes] char * __weak arch_ftrace_match_adjust(char *str, const char *search) ^ kernel/trace/ftrace.c:3876:1: note: declare 'static' if the function is not intended to be used outside of this translation unit char * __weak arch_ftrace_match_adjust(char *str, const char *search) ^ static struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr) ^ kernel/trace/ftrace.c:5048:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr) ^ static 5 warnings generated. vim +/ftrace_alloc_direct_func +5048 kernel/trace/ftrace.c 5047 5049 { 5050 struct ftrace_direct_func *direct; 5051 5052 direct = kmalloc(sizeof(*direct), GFP_KERNEL); 5053 if (!direct) 5054 return NULL; 5055 direct->addr = addr; 5056 direct->count = 0; 5057 list_add_rcu(&direct->next, &ftrace_direct_funcs); 5058 ftrace_direct_func_count++; 5059 return direct; 5060 } 5061 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org