Thanks! I have fixed this in the v3 of the series. btf_find_by_name_kind
is independant of CONFIG_BPF_SYSCALL and btf_type_by_name_kind needs
to be as well.

The mistake was adding a static inline definition of the function
in the !CONFIG_BPF_SYSCALL section which is not needed in this case.

- KP

On 18-Jan 20:44, kbuild test robot wrote:
> Hi KP,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on next-20200116]
> [cannot apply to bpf-next/master bpf/master linus/master security/next-testing v5.5-rc6 v5.5-rc5 v5.5-rc4 v5.5-rc6]
> [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/KP-Singh/MAC-and-Audit-policy-using-eBPF-KRSI/20200117-070342
> base:    2747d5fdab78f43210256cd52fb2718e0b3cce74
> config: nds32-defconfig (attached as .config)
> compiler: nds32le-linux-gcc (GCC) 9.2.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         GCC_VERSION=9.2.0 make.cross ARCH=nds32 
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
>    In file included from kernel/bpf/core.c:27:
> >> include/linux/btf.h:148:38: error: static declaration of 'btf_type_by_name_kind' follows non-static declaration
>      148 | static inline const struct btf_type *btf_type_by_name_kind(
>          |                                      ^~~~~~~~~~~~~~~~~~~~~
>    include/linux/btf.h:70:24: note: previous declaration of 'btf_type_by_name_kind' was here
>       70 | const struct btf_type *btf_type_by_name_kind(
>          |                        ^~~~~~~~~~~~~~~~~~~~~
> 
> vim +/btf_type_by_name_kind +148 include/linux/btf.h
> 
>    136	
>    137	#ifdef CONFIG_BPF_SYSCALL
>    138	const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
>    139	const char *btf_name_by_offset(const struct btf *btf, u32 offset);
>    140	struct btf *btf_parse_vmlinux(void);
>    141	struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
>    142	#else
>    143	static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
>    144							    u32 type_id)
>    145	{
>    146		return NULL;
>    147	}
>  > 148	static inline const struct btf_type *btf_type_by_name_kind(
>    149		struct btf *btf, const char *name, u8 kind)
>    150	{
>    151		return ERR_PTR(-EOPNOTSUPP);
>    152	}
>    153	static inline const char *btf_name_by_offset(const struct btf *btf,
>    154						     u32 offset)
>    155	{
>    156		return NULL;
>    157	}
>    158	#endif
>    159	
> 
> ---
> 0-DAY kernel test infrastructure                 Open Source Technology Center
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation