On 2022/3/3 19:43, Dan Carpenter wrote: > Hi Yang, > > url: https://github.com/0day-ci/linux/commits/Yang-Shi/Make-khugepaged-collapse-readonly-FS-THP-more-consistent/20220301-075903 > base: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev > config: arm64-randconfig-m031-20220227 (https://download.01.org/0day-ci/archive/20220302/202203020034.2Ii9kTrs-lkp@xxxxxxxxx/config) > compiler: aarch64-linux-gcc (GCC) 11.2.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > smatch warnings: > include/linux/huge_mm.h:179 file_thp_enabled() warn: variable dereferenced before check 'vma->vm_file' (see line 177) > mm/khugepaged.c:468 hugepage_vma_check() error: we previously assumed 'vma->vm_file' could be null (see line 455) > include/linux/huge_mm.h:179 file_thp_enabled() warn: variable dereferenced before check 'vma->vm_file' (see line 177) > > vim +179 include/linux/huge_mm.h > > 2224ed1155c07b Yang Shi 2022-02-28 175 static inline bool file_thp_enabled(struct vm_area_struct *vma) > 2224ed1155c07b Yang Shi 2022-02-28 176 { > 2224ed1155c07b Yang Shi 2022-02-28 @177 struct inode *inode = vma->vm_file->f_inode; > ^^^^^^^^^^^^^^ > Dereference. > > 2224ed1155c07b Yang Shi 2022-02-28 178 > 2224ed1155c07b Yang Shi 2022-02-28 @179 return (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS)) && vma->vm_file && > ^^^^^^^^^^^^ > Checked too late. Yep. We should check vma->vm_file first before we access vma->vm_file->f_inode. Thanks. > > 2224ed1155c07b Yang Shi 2022-02-28 180 (vma->vm_flags & VM_EXEC) && > 2224ed1155c07b Yang Shi 2022-02-28 181 !inode_is_open_for_write(inode) && S_ISREG(inode->i_mode); > 2224ed1155c07b Yang Shi 2022-02-28 182 } > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx > > . >
