tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 59fa6a163ffabc1bf25c5e0e33899e268a96d3cc commit: ea7ce6b17c1555b62690471f536eba6358ed3125 [6040/6048] set_memory: allow querying whether set_direct_map_*() is actually enabled config: arm64-randconfig-r024-20210202 (attached as .config) compiler: aarch64-linux-gcc (GCC) 9.3.0 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/next/linux-next.git/commit/?id=ea7ce6b17c1555b62690471f536eba6358ed3125 git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout ea7ce6b17c1555b62690471f536eba6358ed3125 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): In file included from mm/kfence/core.c:26: arch/arm64/include/asm/kfence.h: In function 'kfence_protect_page': >> arch/arm64/include/asm/kfence.h:17:2: error: implicit declaration of function 'set_memory_valid' [-Werror=implicit-function-declaration] 17 | set_memory_valid(addr, 1, !protect); | ^~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for OCTEONTX2_MBOX Depends on NETDEVICES && ETHERNET && NET_VENDOR_MARVELL Selected by - CRYPTO_DEV_OCTEONTX2_CPT && CRYPTO && CRYPTO_HW && (ARM64 || COMPILE_TEST && PCI_MSI && 64BIT && CRYPTO_LIB_AES vim +/set_memory_valid +17 arch/arm64/include/asm/kfence.h b6a4dacdad08f0 Marco Elver 2021-01-22 14 b6a4dacdad08f0 Marco Elver 2021-01-22 15 static inline bool kfence_protect_page(unsigned long addr, bool protect) b6a4dacdad08f0 Marco Elver 2021-01-22 16 { b6a4dacdad08f0 Marco Elver 2021-01-22 @17 set_memory_valid(addr, 1, !protect); b6a4dacdad08f0 Marco Elver 2021-01-22 18 b6a4dacdad08f0 Marco Elver 2021-01-22 19 return true; b6a4dacdad08f0 Marco Elver 2021-01-22 20 } b6a4dacdad08f0 Marco Elver 2021-01-22 21 :::::: The code at line 17 was first introduced by commit :::::: b6a4dacdad08f0a7db077346f89b36aa6891cde7 arm64, kfence: enable KFENCE for ARM64 :::::: TO: Marco Elver :::::: CC: Stephen Rothwell --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org