VM_PROT_COPY
reqprot = writing ? VM_PROT_COPY | VM_PROT_READ : VM_PROT_READ;
if ((fs.fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
if ((fs.fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) != 0) {
(fs->fault_type & (VM_PROT_COPY | VM_PROT_WRITE)) == 0);
fs->fault_type = fs->prot | (fs->fault_type & VM_PROT_COPY);
if ((fault_typea & VM_PROT_COPY) != 0 &&
(fault_typea & VM_PROT_COPY) != 0) {