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Diffstat (limited to 'mm/mprotect.c')
-rw-r--r--mm/mprotect.c23
1 files changed, 20 insertions, 3 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 5faf01ad3ef8..14f93e62270f 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -19,7 +19,8 @@
#include <linux/mempolicy.h>
#include <linux/personality.h>
#include <linux/syscalls.h>
-
+#include <linux/swap.h>
+#include <linux/swapops.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
@@ -28,12 +29,13 @@
static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
unsigned long addr, unsigned long end, pgprot_t newprot)
{
- pte_t *pte;
+ pte_t *pte, oldpte;
spinlock_t *ptl;
pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
do {
- if (pte_present(*pte)) {
+ oldpte = *pte;
+ if (pte_present(oldpte)) {
pte_t ptent;
/* Avoid an SMP race with hardware updated dirty/clean
@@ -43,7 +45,22 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
ptent = pte_modify(ptep_get_and_clear(mm, addr, pte), newprot);
set_pte_at(mm, addr, pte, ptent);
lazy_mmu_prot_update(ptent);
+#ifdef CONFIG_MIGRATION
+ } else if (!pte_file(oldpte)) {
+ swp_entry_t entry = pte_to_swp_entry(oldpte);
+
+ if (is_write_migration_entry(entry)) {
+ /*
+ * A protection check is difficult so
+ * just be safe and disable write
+ */
+ make_migration_entry_read(&entry);
+ set_pte_at(mm, addr, pte,
+ swp_entry_to_pte(entry));
+ }
+#endif
}
+
} while (pte++, addr += PAGE_SIZE, addr != end);
pte_unmap_unlock(pte - 1, ptl);
}