Re: [ammarfaizi2-block:bpf/bpf-next/pr/bpf-sysctl 1/1] kernel/bpf/syscall.c:4944:13: warning: no previous prototype for 'unpriv_ebpf_notify'

[Daniel Borkmann]

On 4/14/22 12:42 AM, kernel test robot wrote:
> tree:   https://github.com/ammarfaizi2/linux-block bpf/bpf-next/pr/bpf-sysctl
> head:   2900005ea287b11dcc8c1b9fcf24893b7ff41d6d
> commit: 2900005ea287b11dcc8c1b9fcf24893b7ff41d6d [1/1] bpf: Move BPF sysctls from kernel/sysctl.c to BPF core
> config: sh-buildonly-randconfig-r001-20220413 (https://download.01.org/0day-ci/archive/20220414/202204140614.Tt9e1fIt-lkp@xxxxxxxxx/config)
> compiler: sh4-linux-gcc (GCC) 11.2.0
> 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
>          # https://github.com/ammarfaizi2/linux-block/commit/2900005ea287b11dcc8c1b9fcf24893b7ff41d6d
>          git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
>          git fetch --no-tags ammarfaizi2-block bpf/bpf-next/pr/bpf-sysctl
>          git checkout 2900005ea287b11dcc8c1b9fcf24893b7ff41d6d
>          # save the config file to linux build tree
>          mkdir build_dir
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=sh SHELL=/bin/bash
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All error/warnings (new ones prefixed by >>):
>
>     sh4-linux-ld: arch/sh/lib/mcount.o: in function `stack_panic':
> > > (.text+0x50): undefined reference to `dump_stack'
> --
> > > kernel/bpf/syscall.c:4944:13: warning: no previous prototype for 'unpriv_ebpf_notify' [-Wmissing-prototypes]
>      4944 | void __weak unpriv_ebpf_notify(int new_state)
>           |             ^~~~~~~~~~~~~~~~~~
>
>
> vim +/unpriv_ebpf_notify +4944 kernel/bpf/syscall.c
>
>    4943	
> > 4944	void __weak unpriv_ebpf_notify(int new_state)
>    4945	{
>    4946	}
>    4947	

(Note that this is no different than the way it was before wrt prototype.)