[tip:core/entry 5/14] kernel/entry/syscall_user_dispatch.c:32:6: warning: no previous prototype for function 'syscall_user_dispatch'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/entry
head:   1568b5540b3e6ff3fe43a2cf889cb777cf8149fc
commit: 7a2cc679e8bb5bfdeef28ec80dc3c34edbc099fd [5/14] kernel: Implement 
selective syscall userspace redirection
config: x86_64-randconfig-a004-20201201 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 
2671fccf0381769276ca8246ec0499adcb9b0355)
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/tip/tip.git/commit/?id=7a2cc679e8bb5bfdeef28ec80dc3c34edbc099fd
        git remote add tip 
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
        git fetch --no-tags tip core/entry
        git checkout 7a2cc679e8bb5bfdeef28ec80dc3c34edbc099fd
        # 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 <l...@intel.com>

All warnings (new ones prefixed by >>):

>> kernel/entry/syscall_user_dispatch.c:32:6: warning: no previous prototype 
>> for function 'syscall_user_dispatch' [-Wmissing-prototypes]
   bool syscall_user_dispatch(struct pt_regs *regs)
        ^
   kernel/entry/syscall_user_dispatch.c:32:1: note: declare 'static' if the 
function is not intended to be used outside of this translation unit
   bool syscall_user_dispatch(struct pt_regs *regs)
   ^
   static 
   1 warning generated.

vim +/syscall_user_dispatch +32 kernel/entry/syscall_user_dispatch.c

    31  
  > 32  bool syscall_user_dispatch(struct pt_regs *regs)
    33  {
    34          struct syscall_user_dispatch *sd = &current->syscall_dispatch;
    35          char state;
    36  
    37          if (likely(instruction_pointer(regs) - sd->offset < sd->len))
    38                  return false;
    39  
    40          if (unlikely(arch_syscall_is_vdso_sigreturn(regs)))
    41                  return false;
    42  
    43          if (likely(sd->selector)) {
    44                  /*
    45                   * access_ok() is performed once, at prctl time, when
    46                   * the selector is loaded by userspace.
    47                   */
    48                  if (unlikely(__get_user(state, sd->selector)))
    49                          do_exit(SIGSEGV);
    50  
    51                  if (likely(state == PR_SYS_DISPATCH_OFF))
    52                          return false;
    53  
    54                  if (state != PR_SYS_DISPATCH_ON)
    55                          do_exit(SIGSYS);
    56          }
    57  
    58          sd->on_dispatch = true;
    59          syscall_rollback(current, regs);
    60          trigger_sigsys(regs);
    61  
    62          return true;
    63  }
    64  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org

.config.gz
Description: application/gzip