Paper bag time. Thanks to Randy for noticing that I didn't actually assign
'present' to anything.
Unfortunately my original patch passed the few simple test cases I gave it,
purely by coincidence.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 #endif
                        }
                }
+
+               vec[i] = present;
        }
        pte_unmap_unlock(ptep-1, ptl);
 
                pgoff = linear_page_index(vma, addr);
                for (i = 0; i < nr; i++, pgoff++)
                        vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
+       } else {
+               for (i = 0; i < nr; i++)
+                       vec[i] = 0;
        }
 
        return nr;