Hi Vincenzo, I love your patch! Yet something to improve: [auto build test ERROR on next-20210125] [cannot apply to arm64/for-next/core xlnx/master arm/for-next soc/for-next kvmarm/next linus/master hnaz-linux-mm/master v5.11-rc6 v5.11-rc5 v5.11-rc4 v5.11-rc6] [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/Vincenzo-Frascino/arm64-ARMv8-5-... base: 59fa6a163ffabc1bf25c5e0e33899e268a96d3cc config: powerpc64-randconfig-r033-20210209 (attached as .config) compiler: powerpc-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://github.com/0day-ci/linux/commit/53907a0b15724b414ddd9201356f92e09... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Vincenzo-Frascino/arm64-ARMv8-5-A-MTE-Add-async-mode-support/20210209-080907 git checkout 53907a0b15724b414ddd9201356f92e09571ef90 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc64 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 >>): powerpc-linux-ld: lib/test_kasan.o: in function `kasan_test_init': test_kasan.c:(.text+0x849a): undefined reference to `kasan_flag_async' powerpc-linux-ld: test_kasan.c:(.text+0x84e2): undefined reference to `kasan_flag_async' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org