On Thu, May 28, 2020 at 11:01 PM Mike Kravetz <[email protected]> wrote: > > 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 <[email protected]> > > > > 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/[email protected] > > > > 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].
I think the proper fix is to add an inline helper (call_get_unmapped_area()?) in linux/mm.h, and make that work properly for the NOMMU case as well. Thanks, Miklos

