Re: [PATCH bpf 4/4] arm64: rethook: Replace kretprobe trampoline with rethook

[kernel test robot]

Hi Masami,

I love your patch! Perhaps something to improve:

[auto build test WARNING on bpf/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Masami-Hiramatsu/kprobes-rethook-ARM-arm64-Replace-kretprobe-trampoline-with-rethook/20220405-195153
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git master
config: arm64-randconfig-r022-20220405 (https://download.01.org/0day-ci/archive/20220406/202204060512.Pzw5bnTd-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project c4a1b07d0979e7ff20d7d541af666d822d66b566)
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 arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/74084aa7903f112b1c3df1f864d49b15d8aba270
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Masami-Hiramatsu/kprobes-rethook-ARM-arm64-Replace-kretprobe-trampoline-with-rethook/20220405-195153
        git checkout 74084aa7903f112b1c3df1f864d49b15d8aba270
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/kernel/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> arch/arm64/kernel/rethook.c:11:22: warning: no previous prototype for function 'arch_rethook_trampoline_callback' [-Wmissing-prototypes]
   unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
                        ^
   arch/arm64/kernel/rethook.c:11:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
   ^
   static 
   1 warning generated.


vim +/arch_rethook_trampoline_callback +11 arch/arm64/kernel/rethook.c

     9	
    10	/* This is called from arch_rethook_trampoline() */
  > 11	unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
    12	{
    13		return rethook_trampoline_handler(regs, regs->regs[29]);
    14	}
    15	NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
    16	

-- 
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https://01.org/lkp