Hi Vincenzo,

I love your patch! Perhaps something to improve:

[auto build test WARNING on next-20210121]
[cannot apply to arm64/for-next/core arm/for-next soc/for-next xlnx/master kvmarm/next linus/master hnaz-linux-mm/master v5.11-rc4 v5.11-rc3 v5.11-rc2 v5.11-rc4]
[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-A-MTE-Add-async-mode-support/20210122-004631
base:    bc085f8fc88fc16796c9f2364e2bfb3fef305cad
config: riscv-randconfig-r003-20210122 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project bd3a387ee76f58caa0d7901f3f84e9bb3d006f27)
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
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/5d51fa880ab55b639b377b24bfe0b8ef6560c14c
        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/20210122-004631
        git checkout 5d51fa880ab55b639b377b24bfe0b8ef6560c14c
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> mm/kasan/report.c:361:6: warning: no previous prototype for function 'kasan_report_async' [-Wmissing-prototypes]
   void kasan_report_async(void)
        ^
   mm/kasan/report.c:361:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void kasan_report_async(void)
   ^
   static 
   1 warning generated.


vim +/kasan_report_async +361 mm/kasan/report.c

   360	
 > 361	void kasan_report_async(void)
   362	{
   363		unsigned long flags;
   364	
   365		start_report(&flags);
   366		pr_err("BUG: KASAN: invalid-access\n");
   367		pr_err("Asynchronous mode enabled: no access details available\n");
   368		dump_stack();
   369		end_report(&flags);
   370	}
   371	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org