tree:   https://chromium.googlesource.com/chromiumos/third_party/kernel chromeos-5.4
head:   737037f5e6df38a08137574fe4bb77fee6254155
commit: a6416be0cae439f19dd089cf243746a9f3ca075a [35/55] CHROMIUM: mm: multigenerational lru: scan kvm mmu pages
config: powerpc64-randconfig-r032-20210702 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project e7e71e9454ed76c1b3d8140170b5333c28bef1be)
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 powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        git remote add chrome-os https://chromium.googlesource.com/chromiumos/third_party/kernel
        git fetch --no-tags chrome-os chromeos-5.4
        git checkout a6416be0cae439f19dd089cf243746a9f3ca075a
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:18:
   In file included from include/linux/kernel.h:11:
   In file included from include/linux/compiler.h:323:
   arch/powerpc/include/asm/barrier.h:47:9: warning: '__lwsync' macro redefined [-Wmacro-redefined]
   #define __lwsync()      __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory")
           ^
   <built-in>:309:9: note: previous definition is here
   #define __lwsync __builtin_ppc_lwsync
           ^
>> arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:536:13: warning: no previous prototype for function 'kvm_arch_mmu_clear_young_walk' [-Wmissing-prototypes]
   __weak void kvm_arch_mmu_clear_young_walk(struct kvm *kvm,
               ^
   arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:536:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __weak void kvm_arch_mmu_clear_young_walk(struct kvm *kvm,
          ^
          static 
   arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:739:12: warning: no previous prototype for function 'kvm_arch_post_init_vm' [-Wmissing-prototypes]
   int __weak kvm_arch_post_init_vm(struct kvm *kvm)
              ^
   arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:739:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int __weak kvm_arch_post_init_vm(struct kvm *kvm)
   ^
   static 
   arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:748:13: warning: no previous prototype for function 'kvm_arch_pre_destroy_vm' [-Wmissing-prototypes]
   void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
               ^
   arch/powerpc/kvm/../../../virt/kvm/kvm_main.c:748:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
   ^
   static 
   4 warnings generated.


vim +/kvm_arch_mmu_clear_young_walk +536 arch/powerpc/kvm/../../../virt/kvm/kvm_main.c

   535	
 > 536	__weak void kvm_arch_mmu_clear_young_walk(struct kvm *kvm,
   537						  struct mmu_notifier_walk *walk)
   538	{
   539	}
   540	

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