Hi Guo, First bad commit (maybe != root cause): tree: https://github.com/c-sky/csky-linux riscv_compat_v3 head: 83f51edf28491d90ae9591131bc7cdd8ce7d3764 commit: ca6210b52caef524df951e60ec5bc09fb3196017 [16/17] riscv: compat: Add COMPAT Kbuild skeletal support config: riscv-randconfig-r021-20220120 (https://download.01.org/0day-ci/archive/20220120/202201202234.gybNbUYU-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project f7b7138a62648f4019c55e4671682af1f851f295) 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/c-sky/csky-linux/commit/ca6210b52caef524df951e60ec5bc0... git remote add csky-linux https://github.com/c-sky/csky-linux git fetch --no-tags csky-linux riscv_compat_v3 git checkout ca6210b52caef524df951e60ec5bc09fb3196017 # 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 arch/riscv/kernel/ 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 >>): int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set, ^ arch/riscv/kernel/compat_signal.c:199:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set, ^ static 1 warning generated. vim +/compat_setup_rt_frame +199 arch/riscv/kernel/compat_signal.c 97edfbe8120313 Guo Ren 2021-12-13 198 97edfbe8120313 Guo Ren 2021-12-13 @199 int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set, 97edfbe8120313 Guo Ren 2021-12-13 200 struct pt_regs *regs) 97edfbe8120313 Guo Ren 2021-12-13 201 { 97edfbe8120313 Guo Ren 2021-12-13 202 struct compat_rt_sigframe __user *frame; 97edfbe8120313 Guo Ren 2021-12-13 203 long err = 0; 97edfbe8120313 Guo Ren 2021-12-13 204 97edfbe8120313 Guo Ren 2021-12-13 205 frame = compat_get_sigframe(ksig, regs, sizeof(*frame)); 97edfbe8120313 Guo Ren 2021-12-13 206 if (!access_ok(frame, sizeof(*frame))) 97edfbe8120313 Guo Ren 2021-12-13 207 return -EFAULT; 97edfbe8120313 Guo Ren 2021-12-13 208 97edfbe8120313 Guo Ren 2021-12-13 209 err |= copy_siginfo_to_user32(&frame->info, &ksig->info); 97edfbe8120313 Guo Ren 2021-12-13 210 97edfbe8120313 Guo Ren 2021-12-13 211 /* Create the ucontext. */ 97edfbe8120313 Guo Ren 2021-12-13 212 err |= __put_user(0, &frame->uc.uc_flags); 97edfbe8120313 Guo Ren 2021-12-13 213 err |= __put_user(NULL, &frame->uc.uc_link); 97edfbe8120313 Guo Ren 2021-12-13 214 err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp); 97edfbe8120313 Guo Ren 2021-12-13 215 err |= compat_setup_sigcontext(frame, regs); 97edfbe8120313 Guo Ren 2021-12-13 216 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 97edfbe8120313 Guo Ren 2021-12-13 217 if (err) 97edfbe8120313 Guo Ren 2021-12-13 218 return -EFAULT; 97edfbe8120313 Guo Ren 2021-12-13 219 97edfbe8120313 Guo Ren 2021-12-13 220 regs->ra = (unsigned long)COMPAT_VDSO_SYMBOL( 97edfbe8120313 Guo Ren 2021-12-13 221 current->mm->context.vdso, rt_sigreturn); 97edfbe8120313 Guo Ren 2021-12-13 222 97edfbe8120313 Guo Ren 2021-12-13 223 /* 97edfbe8120313 Guo Ren 2021-12-13 224 * Set up registers for signal handler. 97edfbe8120313 Guo Ren 2021-12-13 225 * Registers that we don't modify keep the value they had from 97edfbe8120313 Guo Ren 2021-12-13 226 * user-space at the time we took the signal. 97edfbe8120313 Guo Ren 2021-12-13 227 * We always pass siginfo and mcontext, regardless of SA_SIGINFO, 97edfbe8120313 Guo Ren 2021-12-13 228 * since some things rely on this (e.g. glibc's debug/segfault.c). 97edfbe8120313 Guo Ren 2021-12-13 229 */ 97edfbe8120313 Guo Ren 2021-12-13 230 regs->epc = (unsigned long)ksig->ka.sa.sa_handler; 97edfbe8120313 Guo Ren 2021-12-13 231 regs->sp = (unsigned long)frame; 97edfbe8120313 Guo Ren 2021-12-13 232 regs->a0 = ksig->sig; /* a0: signal number */ 97edfbe8120313 Guo Ren 2021-12-13 233 regs->a1 = (unsigned long)(&frame->info); /* a1: siginfo pointer */ 97edfbe8120313 Guo Ren 2021-12-13 234 regs->a2 = (unsigned long)(&frame->uc); /* a2: ucontext pointer */ 97edfbe8120313 Guo Ren 2021-12-13 235 :::::: The code at line 199 was first introduced by commit :::::: 97edfbe8120313cf2a214c61d72175cf6f564430 riscv: compat: signal: Add rt_frame implementation :::::: TO: Guo Ren <guoren(a)linux.alibaba.com&gt; :::::: CC: Guo Ren <guoren(a)linux.alibaba.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org