On Thu, Mar 3, 2022 at 3:48 AM Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote: > > 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. Ah, yes, thanks for the report and the suggestion. > > 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 > > > > . > > >
