if (pte_present(oldpte)) {
pte_t ptent;
- /* Avoid an SMP race with hardware updated dirty/clean
- * bits by wiping the pte and then setting the new pte
- * into place.
- */
- ptent = ptep_get_and_clear(mm, addr, pte);
+ ptent = ptep_modify_prot_start(mm, addr, pte);
ptent = pte_modify(ptent, newprot);
+
/*
* Avoid taking write faults for pages we know to be
* dirty.
*/
if (dirty_accountable && pte_dirty(ptent))
ptent = pte_mkwrite(ptent);
- set_pte_at(mm, addr, pte, ptent);
+
+ ptep_modify_prot_commit(mm, addr, pte, ptent);
#ifdef CONFIG_MIGRATION
} else if (!pte_file(oldpte)) {
swp_entry_t entry = pte_to_swp_entry(oldpte);
* If we make a private mapping writable we increase our commit;
* but (without finer accounting) cannot reduce our commit if we
* make it unwritable again.
- *
- * FIXME? We haven't defined a VM_NORESERVE flag, so mprotecting
- * a MAP_NORESERVE private mapping to writable will now reserve.
*/
if (newflags & VM_WRITE) {
- if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))) {
+ if (!(oldflags & (VM_ACCOUNT|VM_WRITE|
+ VM_SHARED|VM_NORESERVE))) {
charged = nrpages;
if (security_vm_enough_memory(charged))
return -ENOMEM;
end = start + len;
if (end <= start)
return -ENOMEM;
- if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM))
+ if (!arch_validate_prot(prot))
return -EINVAL;
reqprot = prot;