Hi Mark,

I love your patch! Perhaps something to improve:

[auto build test WARNING on next-20200605]
[cannot apply to arm64/for-next/core arm-perf/for-next/perf kselftest/next v5.7 v5.7-rc7 v5.7-rc6 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/Mark-Brown/arm64-vdso-getcpu-support/20200605-212237
base:    af30725c132e2e5c5369b60369ff0771fde7d4ff
config: arm64-randconfig-r016-20200607 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project e429cffd4f228f70c1d9df0e5d77c08590dd9766)
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 arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

quoted

arch/arm64/kernel/vdso/vgetcpu.c:33:5: warning: no previous prototype for function '__kernel_getcpu' [-Wmissing-prototypes]

int __kernel_getcpu(unsigned int *cpu, unsigned int *node,
^
arch/arm64/kernel/vdso/vgetcpu.c:33:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int __kernel_getcpu(unsigned int *cpu, unsigned int *node,
^
static
1 warning generated.
--

quoted

arch/arm64/kernel/vdso/vgetcpu.c:33:5: warning: no previous prototype for function '__kernel_getcpu' [-Wmissing-prototypes]

int __kernel_getcpu(unsigned int *cpu, unsigned int *node,
^
arch/arm64/kernel/vdso/vgetcpu.c:33:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int __kernel_getcpu(unsigned int *cpu, unsigned int *node,
^
static
1 warning generated.
arch/arm64/kernel/vdso/vgettimeofday.c:9:5: warning: no previous prototype for function '__kernel_clock_gettime' [-Wmissing-prototypes]
int __kernel_clock_gettime(clockid_t clock,
^
arch/arm64/kernel/vdso/vgettimeofday.c:9:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int __kernel_clock_gettime(clockid_t clock,
^
static
arch/arm64/kernel/vdso/vgettimeofday.c:15:5: warning: no previous prototype for function '__kernel_gettimeofday' [-Wmissing-prototypes]
int __kernel_gettimeofday(struct __kernel_old_timeval *tv,
^
arch/arm64/kernel/vdso/vgettimeofday.c:15:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int __kernel_gettimeofday(struct __kernel_old_timeval *tv,
^
static
arch/arm64/kernel/vdso/vgettimeofday.c:21:5: warning: no previous prototype for function '__kernel_clock_getres' [-Wmissing-prototypes]
int __kernel_clock_getres(clockid_t clock_id,
^
arch/arm64/kernel/vdso/vgettimeofday.c:21:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int __kernel_clock_getres(clockid_t clock_id,
^
static
3 warnings generated.

vim +/__kernel_getcpu +33 arch/arm64/kernel/vdso/vgetcpu.c

    32	
  > 33	int __kernel_getcpu(unsigned int *cpu, unsigned int *node,

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