tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git x86/entry head: a55e3844bc8afc350ee4efd87442c9c74f101b34 commit: 0e43d3bd147e265b320614052d684f1a4767fd1f [12/16] x86/entry: Use generic syscall exit functionality config: x86_64-randconfig-r025-20200719 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 3504acc33e8b9ddd7de71d75cdc329a14dbf58d9) 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 git checkout 0e43d3bd147e265b320614052d684f1a4767fd1f # 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 >>): void arch_do_signal(struct pt_regs *regs) ^ arch/x86/kernel/signal.c:806:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void arch_do_signal(struct pt_regs *regs) ^ static 1 warning generated. vim +/arch_do_signal +806 arch/x86/kernel/signal.c 800 801 /* 802 * Note that 'init' is a special process: it doesn't get signals it doesn't 803 * want to handle. Thus you cannot kill init even with a SIGKILL even by 804 * mistake. 805 */ 807 { 808 struct ksignal ksig; 809 810 if (get_signal(&ksig)) { 811 /* Whee! Actually deliver the signal. */ 812 handle_signal(&ksig, regs); 813 return; 814 } 815 816 /* Did we come from a system call? */ 817 if (syscall_get_nr(current, regs) >= 0) { 818 /* Restart the system call - no handlers present */ 819 switch (syscall_get_error(current, regs)) { 820 case -ERESTARTNOHAND: 821 case -ERESTARTSYS: 822 case -ERESTARTNOINTR: 823 regs->ax = regs->orig_ax; 824 regs->ip -= 2; 825 break; 826 827 case -ERESTART_RESTARTBLOCK: 828 regs->ax = get_nr_restart_syscall(regs); 829 regs->ip -= 2; 830 break; 831 } 832 } 833 834 /* 835 * If there's no signal to deliver, we just put the saved sigmask 836 * back. 837 */ 838 restore_saved_sigmask(); 839 } 840 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org