Hi "Aneesh, I love your patch! Yet something to improve: [auto build test ERROR on powerpc/next] [also build test ERROR on next-20200611] [cannot apply to v5.7] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Aneesh-Kumar-K-V/Kernel-userspac... base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next config: powerpc-randconfig-r003-20200612 (attached as .config) compiler: powerpc64le-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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 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 >>, old ones prefixed by <<): arch/powerpc/mm/book3s64/pkeys.c: In function 'setup_kuep': 207 | if (smp_processor_id() == boot_cpuid) { | ^~~~~~~~~~ arch/powerpc/mm/book3s64/pkeys.c:207:28: note: each undeclared identifier is reported only once for each function it appears in arch/powerpc/mm/book3s64/pkeys.c: In function 'setup_kuap': arch/powerpc/mm/book3s64/pkeys.c:228:28: error: 'boot_cpuid' undeclared (first use in this function) 228 | if (smp_processor_id() == boot_cpuid) { | ^~~~~~~~~~ vim +/boot_cpuid +207 arch/powerpc/mm/book3s64/pkeys.c 92e3da3cf193fd arch/powerpc/mm/pkeys.c Ram Pai 2018-01-18 200 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 201 #ifdef CONFIG_PPC_KUEP 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 202 void __init setup_kuep(bool disabled) 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 203 { 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 204 if (disabled || !early_radix_enabled()) 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 205 return; 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 206 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 @207 if (smp_processor_id() == boot_cpuid) { 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 208 pr_info("Activating Kernel Userspace Execution Prevention\n"); 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 209 cur_cpu_spec->mmu_features |= MMU_FTR_KUEP; 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 210 } 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 211 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 212 /* 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 213 * Radix always uses key0 of the IAMR to determine if an access is 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 214 * allowed. We set bit 0 (IBM bit 1) of key0, to prevent instruction 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 215 * fetch. 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 216 */ 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 217 mtspr(SPRN_IAMR, AMR_KUEP_BLOCKED); 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 218 isync(); 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 219 } 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 220 #endif 82b6d6aaa3e29c arch/powerpc/mm/book3s64/pkeys.c Aneesh Kumar K.V 2020-06-10 221 :::::: The code at line 207 was first introduced by commit :::::: 82b6d6aaa3e29c1f61639eaf61333b3f84b34c4d powerpc/book3s64/kuep: Move KUEP related function outside radix :::::: TO: Aneesh Kumar K.V <aneesh.kumar(a)linux.ibm.com&gt; :::::: CC: 0day robot <lkp(a)intel.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org