tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: d2f38a3c6507b2520101f9a3807ed98f1bdc545a commit: 17b251a290ba84a0c2c5c82df9596cb2e7207ca6 ftrace/sh: Add arch_ftrace_ops_list_func stub to have compressed image still link date: 13 days ago config: sh-buildonly-randconfig-r001-20211109 (attached as .config) compiler: sh4-linux-gcc (GCC) 11.2.0 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/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 17b251a290ba84a0c2c5c82df9596cb2e7207ca6 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=sh 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 >>): arch/sh/boot/compressed/misc.c:109:6: warning: no previous prototype for '__stack_chk_fail' [-Wmissing-prototypes] 109 | void __stack_chk_fail(void) | ^~~~~~~~~~~~~~~~ arch/sh/boot/compressed/misc.c:115:6: warning: no previous prototype for 'ftrace_stub' [-Wmissing-prototypes] 115 | void ftrace_stub(void) | ^~~~~~~~~~~ 118 | void arch_ftrace_ops_list_func(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~ arch/sh/boot/compressed/misc.c:128:6: warning: no previous prototype for 'decompress_kernel' [-Wmissing-prototypes] 128 | void decompress_kernel(void) | ^~~~~~~~~~~~~~~~~ vim +/arch_ftrace_ops_list_func +118 arch/sh/boot/compressed/misc.c 113 114 /* Needed because vmlinux.lds.h references this */ 115 void ftrace_stub(void) 116 { 117 } 119 { 120 } 121 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org