Hi Masahiro, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [cannot apply to v5.3-rc3 next-20190809] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Masahiro-Yamada/kbuild-re-implement-detection-of-CONFIG-options-leaked-to-user-space/20190811-085800 config: i386-defconfig (attached as .config) compiler: gcc-7 (Debian 7.4.0-10) 7.4.0 reproduce: # save the attached .config to linux build tree make ARCH=i386 If you fix the issue, kindly add following tag Reported-by: kbuild test robot All warnings (new ones prefixed by >>): >> warning: include/uapi/asm-generic/fcntl.h: leak CONFIG_64BIT to user-space >> warning: include/uapi/linux/raw.h: leak CONFIG_MAX_RAW_DEVS to user-space >> warning: include/uapi/linux/pktcdvd.h: leak CONFIG_CDROM_PKTCDVD_WCACHE to user-space >> warning: include/uapi/linux/hw_breakpoint.h: leak CONFIG_HAVE_MIXED_BREAKPOINTS_REGS to user-space >> warning: include/uapi/linux/eventpoll.h: leak CONFIG_PM_SLEEP to user-space >> warning: include/uapi/linux/elfcore.h: leak CONFIG_BINFMT_ELF_FDPIC to user-space >> warning: include/uapi/linux/atmdev.h: leak CONFIG_COMPAT to user-space >> warning: arch/x86/include/uapi/asm/mman.h: leak CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS to user-space >> warning: arch/x86/include/uapi/asm/auxvec.h: leak CONFIG_IA32_EMULATION to user-space >> warning: arch/x86/include/uapi/asm/auxvec.h: leak CONFIG_X86_64 to user-space 1 real 10 user 4 sys 762.47% cpu make INSTALL_HDR_PATH=/tmp/usr/src/linux-headers-i386-defconfig-723c8e514c09af9516a181307cdaa1ee6a874ffd headers_install --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation