Hi Masami, I love your patch! Yet something to improve: [auto build test ERROR on rostedt-trace/for-next] [also build test ERROR on tip/x86/core linus/master v5.17-rc1 next-20220124] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Masami-Hiramatsu/fprobe-Introduc... base: https://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git for-next config: i386-tinyconfig (https://download.01.org/0day-ci/archive/20220125/202201250509.MSbKNePn-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/6366c7f830e71242dd9538fbdb09acdcc... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Masami-Hiramatsu/fprobe-Introduce-fprobe-function-entry-exit-probe/20220125-001253 git checkout 6366c7f830e71242dd9538fbdb09acdccea6e786 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/kernel/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from arch/x86/kernel/process.c:48: arch/x86/include/asm/unwind.h: In function 'unwind_recover_kretprobe': 113 | &state->kr_cur); | ^~ arch/x86/kernel/process.c: At top level: arch/x86/kernel/process.c:887:13: warning: no previous prototype for 'arch_post_acpi_subsys_init' [-Wmissing-prototypes] 887 | void __init arch_post_acpi_subsys_init(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ -- In file included from arch/x86/kernel/unwind_guess.c:7: arch/x86/include/asm/unwind.h: In function 'unwind_recover_kretprobe': 113 | &state->kr_cur); | ^~ vim +113 arch/x86/include/asm/unwind.h 106 107 static inline 108 unsigned long unwind_recover_kretprobe(struct unwind_state *state, 109 unsigned long addr, unsigned long *addr_p) 110 { 111 if (IS_ENABLED(CONFIG_RETHOOK) && is_rethook_trampoline(addr)) 112 return rethook_find_ret_addr(state->task, (unsigned long)addr_p, 114 #ifdef CONFIG_KRETPROBES 115 return is_kretprobe_trampoline(addr) ? 116 kretprobe_find_ret_addr(state->task, addr_p, &state->kr_cur) : 117 addr; 118 #else 119 return addr; 120 #endif 121 } 122 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org