On 5/28/20 1:37 AM, kbuild test robot wrote: > Hi Mike, > > I love your patch! Yet something to improve: > > [auto build test ERROR on miklos-vfs/overlayfs-next] > [also build test ERROR on linus/master v5.7-rc7] > [cannot apply to linux/master next-20200526] > [if your patch is applied to the wrong git tree, please drop us a note to help > improve the system. BTW, we also suggest to use '--base' option to specify the > base tree in git format-patch, please see https://stackoverflow.com/a/37406982] > > url: https://github.com/0day-ci/linux/commits/Mike-Kravetz/ovl-provide-real_file-and-overlayfs-get_unmapped_area/20200528-080533 > base: https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs.git overlayfs-next > config: h8300-randconfig-r036-20200528 (attached as .config) > compiler: h8300-linux-gcc (GCC) 9.3.0 > 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 > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=h8300 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kbuild test robot <lkp@xxxxxxxxx> > > All error/warnings (new ones prefixed by >>, old ones prefixed by <<): > > fs/overlayfs/file.c: In function 'ovl_get_unmapped_area': >>> fs/overlayfs/file.c:768:14: error: 'struct mm_struct' has no member named 'get_unmapped_area' > 768 | current->mm->get_unmapped_area)(realfile, > | ^~ >>> fs/overlayfs/file.c:770:1: warning: control reaches end of non-void function [-Wreturn-type] > 770 | } > | ^ > > vim +768 fs/overlayfs/file.c > > 760 > 761 static unsigned long ovl_get_unmapped_area(struct file *file, > 762 unsigned long uaddr, unsigned long len, > 763 unsigned long pgoff, unsigned long flags) > 764 { > 765 struct file *realfile = real_file(file); > 766 > 767 return (realfile->f_op->get_unmapped_area ?: > > 768 current->mm->get_unmapped_area)(realfile, > 769 uaddr, len, pgoff, flags); > > 770 } > 771 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx > Well yuck! get_unmapped_area is not part of mm_struct if !CONFIG_MMU. Miklos, would adding '#ifdef CONFIG_MMU' around the overlayfs code be too ugly for you? Another option is to use real_file() in the mmap code as done in [1]. Sorry for all the questions. However, I want to make sure you are happy with any overlayfs changes. [1] https://lore.kernel.org/linux-mm/04a00e3b-539c-236f-e43b-0024ef94b7cb@xxxxxxxxxx/ -- Mike Kravetz
