tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core
head:   42da62769d7de07bea28f81307723050f3339727
commit: 42da62769d7de07bea28f81307723050f3339727 [8/8] sched/cputime: Improve cputime_adjust()
config: x86_64-randconfig-a013-20200521 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 3393cc4cebf9969db94dc424b7a2b6195589c33b)
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 x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        git checkout 42da62769d7de07bea28f81307723050f3339727
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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

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

>> lib/math/div64.c:194:1: warning: attribute declaration must precede definition [-Wignored-attributes]
__weak u64 mul_u64_u64_div_u64(u64 a, u64 b, u64 c)
^
include/linux/compiler_attributes.h:271:56: note: expanded from macro '__weak'
#define __weak                          __attribute__((__weak__))
^
arch/x86/include/asm/div64.h:81:28: note: previous definition is here
extern __always_inline u64 mul_u64_u64_div_u64(u64 a, u64 mul, u64 div)
^
1 warning generated.

vim +194 lib/math/div64.c

   193	
 > 194	__weak u64 mul_u64_u64_div_u64(u64 a, u64 b, u64 c)

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