Hi Peter, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v5.14-rc1 next-20210715] [cannot apply to hnaz-linux-mm/master asm-generic/master linux/master] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Peter-Xu/userfaultfd-wp-Support-... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 8096acd7442e613fad0354fc8dfdb2003cceea0b config: i386-randconfig-s002-20210714 (attached as .config) compiler: gcc-10 (Debian 10.2.1-6) 10.2.1 20210110 reproduce: # apt-get install sparse # sparse version: v0.6.3-341-g8af24329-dirty # https://github.com/0day-ci/linux/commit/f8dd355edbfe948f84c8aaa10a5173656... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Peter-Xu/userfaultfd-wp-Support-shmem-and-hugetlbfs/20210715-062718 git checkout f8dd355edbfe948f84c8aaa10a5173656aa2778c # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) mm/hugetlb.c:444:12: sparse: sparse: context imbalance in 'allocate_file_region_entries' - wrong count at exit mm/hugetlb.c:517:13: sparse: sparse: context imbalance in 'region_add' - wrong count at exit mm/hugetlb.c:584:13: sparse: sparse: context imbalance in 'region_chg' - wrong count at exit mm/hugetlb.c: note: in included file (through include/linux/mmzone.h, include/linux/gfp.h, include/linux/mm.h): include/linux/page-flags.h:183:29: sparse: sparse: context imbalance in 'hugetlb_cow' - unexpected unlock mm/hugetlb.c:5386:25: sparse: sparse: context imbalance in 'follow_hugetlb_page' - different lock contexts for basic block Please review and possibly fold the followup patch. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org