tree:   https://github.com/tobetter/linux odroid-5.13.y
head:   ec41beb389cd0d7ab68345d550334d44842a2cb1
commit: 4c6761c55d4f15337b88e29cb05834a753ddc506 [41/93] ODROID-XU4: char: exynos: add /dev/gpiomem device for rootless user GPIO access
config: arm-randconfig-r034-20210617 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 64720f57bea6a6bf033feef4a5751ab9c0c3b401)
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 arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://github.com/tobetter/linux/commit/4c6761c55d4f15337b88e29cb05834a753ddc506
        git remote add tobetter-linux https://github.com/tobetter/linux
        git fetch --no-tags tobetter-linux odroid-5.13.y
        git checkout 4c6761c55d4f15337b88e29cb05834a753ddc506
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm 

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

All errors (new ones prefixed by >>):

>> drivers/char/exynos-gpiomem.c:121:22: error: implicit declaration of function 'phys_mem_access_prot' [-Werror,-Wimplicit-function-declaration]
           vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
                               ^
   1 error generated.


vim +/phys_mem_access_prot +121 drivers/char/exynos-gpiomem.c

   106	
   107	static int exynos_gpiomem_mmap(struct file *file, struct vm_area_struct *vma)
   108	{
   109		int gpio_area = 0;
   110	
   111		while (gpio_area < inst->gpio_area_count) {
   112			if ((inst->gpio_regs_phys[gpio_area] >> PAGE_SHIFT) == vma->vm_pgoff)
   113				goto found;
   114	
   115			gpio_area++;
   116		}
   117	
   118		return -EACCES;
   119	
   120	found:
 > 121		vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
   122				PAGE_SIZE,
   123				vma->vm_page_prot);
   124	
   125		vma->vm_ops = &exynos_gpiomem_vm_ops;
   126	
   127		if (remap_pfn_range(vma, vma->vm_start,
   128					vma->vm_pgoff,
   129					PAGE_SIZE,
   130					vma->vm_page_prot)) {
   131			return -EAGAIN;
   132		}
   133	
   134		return 0;
   135	}
   136	

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