ng, no need to cast the error contants into unsigned long. If you compile this code on a 64-bit machine somehow, you'll see following warning: CC mm/nommu.o mm/nommu.c: In function `do_mmap_pgoff': mm/nommu.c:1411: warning: overflow in implicit constant conversion Signed-off-by: Namhyung Kim Acked-by: Greg Ungerer Cc: David Howells Cc: Paul Mundt Cc: Geert Uytterhoeven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds I@.x