Re: [PATCH bpf-next v4 1/4] bpf: add bpf_get_cpu_cycles kfunc

[kernel test robot <lkp@intel.com>]

Hi Vadim,

kernel test robot noticed the following build errors:

[auto build test ERROR on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Vadim-Fedorenko/bpf-add-bpf_cpu_cycles_to_ns-helper/20241108-051950
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20241107211206.2814069-1-vadfed%40meta.com
patch subject: [PATCH bpf-next v4 1/4] bpf: add bpf_get_cpu_cycles kfunc
config: arm-randconfig-003-20241108 (https://download.01.org/0day-ci/archive/20241108/202411080912.TtCTNymw-lkp@intel.com/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241108/202411080912.TtCTNymw-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411080912.TtCTNymw-lkp@intel.com/

All errors (new ones prefixed by >>):

   kernel/bpf/helpers.c:3029:18: warning: extra tokens at end of #ifdef directive [-Wextra-tokens]
   #ifdef IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY)
                    ^
                    //
>> kernel/bpf/helpers.c:3032:9: error: call to undeclared function '__arch_get_hw_counter'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
           return __arch_get_hw_counter(1, NULL);
                  ^
   kernel/bpf/helpers.c:3128:18: warning: extra tokens at end of #ifdef directive [-Wextra-tokens]
   #ifdef IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY)
                    ^
                    //
   2 warnings and 1 error generated.


vim +/__arch_get_hw_counter +3032 kernel/bpf/helpers.c

  3028	
  3029	#ifdef IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY)
  3030	__bpf_kfunc u64 bpf_get_cpu_cycles(void)
  3031	{
> 3032		return __arch_get_hw_counter(1, NULL);
  3033	}
  3034	#endif
  3035	

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