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'

From: Daniel Borkmann
Date: Wed Apr 13 2022 - 19:08:08 EST


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.)