8 /* * Note on compatibility: * * This must be the same size for both 32 and 64-bit processes, since * the same format will be used by both. * * Removal of unused fields is OK, as long as the change in layout * does not affect supported fields. * * It is OK to add fields to this structure, since the kernel allocates * the space. Re-use of fields is more complicated - see the feature * word passed to the system call. */