On Thu, Jul 12, 2018 at 06:20:39PM +0200, Oleg Nesterov wrote: > Kirill, I am not trying to review this change (but it looks good to me), > just a silly question... > > On 07/12, Kirill A. Shutemov wrote: > > > > This can be fixed by assigning anonymous VMAs own vm_ops and not relying > > on it being NULL. > > I agree, this makes sense, but... > > > If ->mmap() failed to set ->vm_ops, mmap_region() will set it to > > dummy_vm_ops. > > Shouldn't this change alone fix the problem? Unfortunately, no. I've tried it before. Mapping /dev/zero with MAP_PRIVATE hast to produce anonymous VMA. The trick with dummy_vm_ops wouldn't be able to handle the situation. -- Kirill A. Shutemov
