[kbuild-all] [arm-platforms:kvm/protected-memory 3/16] arch/x86/mm/mem_encrypt_common.c:16:6: warning: no previous prototype for function 'force_dma_unencrypted'

Hi Kirill, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git kvm/protected-memory head: d9455e6eabef4b9be5f33c418a8046e0389edade commit: dbd4c551b3d34cb3e06e575eb205e2056f4a6e76 [3/16] x86/kvm: Make DMA pages shared config: x86_64-randconfig-a014-20200916 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 9e3842d60351f986d77dfe0a94f76e4fd895f188) 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 dbd4c551b3d34cb3e06e575eb205e2056f4a6e76 # 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 >>): bool force_dma_unencrypted(struct device *dev) ^ arch/x86/mm/mem_encrypt_common.c:16:1: note: declare 'static' if the function is not intended to be used outside of this translation unit bool force_dma_unencrypted(struct device *dev) ^ static 1 warning generated. # https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/com... git remote add arm-platforms https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git git fetch --no-tags arm-platforms kvm/protected-memory git checkout dbd4c551b3d34cb3e06e575eb205e2056f4a6e76 vim +/force_dma_unencrypted +16 arch/x86/mm/mem_encrypt_common.c 0fdb85af352f8f Kirill A. Shutemov 2020-05-22 14 0fdb85af352f8f Kirill A. Shutemov 2020-05-22 15 /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */ 0fdb85af352f8f Kirill A. Shutemov 2020-05-22 @16 bool force_dma_unencrypted(struct device *dev) :::::: The code at line 16 was first introduced by commit :::::: 0fdb85af352f8f003ce368eaeee57406f748801e x86/mm: Move force_dma_unencrypted() to common code :::::: TO: Kirill A. Shutemov <kirill(a)shutemov.name&gt; :::::: CC: Marc Zyngier <maz(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org