tree:   https://github.com/ammarfaizi2/linux-block akpm/mm/mm-unstable
head:   fc93ddbd10610f8f621fba75c1a0f110f543a7bd
commit: e634e7e18f3bf0b30b8f9f16434929d950b7ac33 [146/162] mm/memremap: Introduce pgmap_request_folio() using pgmap offsets
config: alpha-randconfig-s041-20221023
compiler: alpha-linux-gcc (GCC) 12.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://github.com/ammarfaizi2/linux-block/commit/e634e7e18f3bf0b30b8f9f16434929d950b7ac33
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block akpm/mm/mm-unstable
        git checkout e634e7e18f3bf0b30b8f9f16434929d950b7ac33
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=alpha SHELL=/bin/bash drivers/dax/

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

sparse warnings: (new ones prefixed by >>)
   drivers/dax/mapping.c: note: in included file (through include/linux/mm.h):
>> include/linux/memremap.h:258:16: sparse: sparse: Using plain integer as NULL pointer

vim +258 include/linux/memremap.h

8e37d00a850160 Christoph Hellwig 2017-12-29  254  
e634e7e18f3bf0 Dan Williams      2022-10-20  255  static inline struct folio *pgmap_request_folio(struct dev_pagemap *pgmap,
e634e7e18f3bf0 Dan Williams      2022-10-20  256  						pgoff_t pgmap_offset, int order)
e8ca415e7cc5d6 Dan Williams      2022-10-14  257  {
e8ca415e7cc5d6 Dan Williams      2022-10-14 @258  	return false;
e8ca415e7cc5d6 Dan Williams      2022-10-14  259  }
e8ca415e7cc5d6 Dan Williams      2022-10-14  260  

:::::: The code at line 258 was first introduced by commit
:::::: e8ca415e7cc5d6c4d431b3dda58877ff24b021ee fsdax: introduce pgmap_request_folios()

:::::: TO: Dan Williams <dan.j.williams@intel.com>
:::::: CC: Andrew Morton <akpm@linux-foundation.org>

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp