[paulmck-rcu:dev.2023.04.26a 35/51] arch/loongarch/kernel/process.c:68:1: warning: 'noreturn' function does return

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2023.04.26a
head:   56b38a90a12f76e463a7381d8cff854926fa2b59
commit: 2b927bfdda366c1719e021cd0e9688baf933c9cf [35/51] objtool: Fix for unreachable instruction warning
config: loongarch-randconfig-r012-20230427 (https://download.01.org/0day-ci/archive/20230427/202304271412.cbmTIpbf-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 12.1.0
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
        # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=2b927bfdda366c1719e021cd0e9688baf933c9cf
        git remote add paulmck-rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
        git fetch --no-tags paulmck-rcu dev.2023.04.26a
        git checkout 2b927bfdda366c1719e021cd0e9688baf933c9cf
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash arch/loongarch/kernel/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304271412.cbmTIpbf-lkp@intel.com/

All warnings (new ones prefixed by >>):

   arch/loongarch/kernel/process.c:109:5: warning: no previous prototype for 'arch_dup_task_struct' [-Wmissing-prototypes]
     109 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
         |     ^~~~~~~~~~~~~~~~~~~~
   arch/loongarch/kernel/process.c:301:15: warning: no previous prototype for 'arch_align_stack' [-Wmissing-prototypes]
     301 | unsigned long arch_align_stack(unsigned long sp)
         |               ^~~~~~~~~~~~~~~~
   arch/loongarch/kernel/process.c: In function 'arch_cpu_idle_dead':
>> arch/loongarch/kernel/process.c:68:1: warning: 'noreturn' function does return
      68 | }
         | ^


vim +/noreturn +68 arch/loongarch/kernel/process.c

803b0fc5c3f2ba Huacai Chen 2022-05-31  63  
46859ac8af52ae Huacai Chen 2022-05-31  64  #ifdef CONFIG_HOTPLUG_CPU
46859ac8af52ae Huacai Chen 2022-05-31  65  void arch_cpu_idle_dead(void)
46859ac8af52ae Huacai Chen 2022-05-31  66  {
46859ac8af52ae Huacai Chen 2022-05-31  67  	play_dead();
46859ac8af52ae Huacai Chen 2022-05-31 @68  }
46859ac8af52ae Huacai Chen 2022-05-31  69  #endif
46859ac8af52ae Huacai Chen 2022-05-31  70  

:::::: The code at line 68 was first introduced by commit
:::::: 46859ac8af52ae599e1b51992ddef3eb43f295fc LoongArch: Add multi-processor (SMP) support

:::::: TO: Huacai Chen <chenhuacai@loongson.cn>
:::::: CC: Huacai Chen <chenhuacai@loongson.cn>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests