tree:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/kexec
head:   d1bbc35fcab28668c8992c4d5777234b794d7306
commit: 4c3c31230c912d8f2e49c775555aadf79a43d418 [9/13] arm64: kexec: move relocation function setup
config: arm64-randconfig-r024-20210202 (attached as .config)
compiler: aarch64-linux-gcc (GCC) 9.3.0
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://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?id=4c3c31230c912d8f2e49c775555aadf79a43d418
        git remote add arm64 https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
        git fetch --no-tags arm64 for-next/kexec
        git checkout 4c3c31230c912d8f2e49c775555aadf79a43d418
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm64 

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

All warnings (new ones prefixed by >>):

>> arch/arm64/kernel/machine_kexec.c:62:5: warning: no previous prototype for 'machine_kexec_post_load' [-Wmissing-prototypes]
      62 | int machine_kexec_post_load(struct kimage *kimage)
         |     ^~~~~~~~~~~~~~~~~~~~~~~
   arch/arm64/kernel/machine_kexec.c:238:6: warning: no previous prototype for 'machine_crash_shutdown' [-Wmissing-prototypes]
     238 | void machine_crash_shutdown(struct pt_regs *regs)
         |      ^~~~~~~~~~~~~~~~~~~~~~


vim +/machine_kexec_post_load +62 arch/arm64/kernel/machine_kexec.c

    61	
  > 62	int machine_kexec_post_load(struct kimage *kimage)
    63	{
    64		void *reloc_code = page_to_virt(kimage->control_code_page);
    65	
    66		memcpy(reloc_code, arm64_relocate_new_kernel,
    67		       arm64_relocate_new_kernel_size);
    68		kimage->arch.kern_reloc = __pa(reloc_code);
    69	
    70		/* Flush the reloc_code in preparation for its execution. */
    71		__flush_dcache_area(reloc_code, arm64_relocate_new_kernel_size);
    72		flush_icache_range((uintptr_t)reloc_code, (uintptr_t)reloc_code +
    73				   arm64_relocate_new_kernel_size);
    74	
    75		return 0;
    76	}
    77	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org