TO: Peter Zijlstra <peterz(a)infradead.org&gt; Hi Peter, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git objtool/retpoline head: 72260c7ae8c8e1265dbd20213ce67ddfaf76df8e commit: 72260c7ae8c8e1265dbd20213ce67ddfaf76df8e [15/15] objtool,x86: Rewrite retpoline thunk calls config: x86_64-randconfig-a001-20210318 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project fcc1ce00931751ac02498986feb37744e9ace8de) 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/peterz/queue.git/commit/?... git remote add peterz-queue https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git git fetch --no-tags peterz-queue objtool/retpoline git checkout 72260c7ae8c8e1265dbd20213ce67ddfaf76df8e # 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 >>): --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org