X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=mm%2Fmprotect.c;h=367b7f6c063736958e7f266e3a21fd32c3613245;hb=d08b3851da41d0ee60851f2c75b118e1f7a5fc89;hp=4c14d4289b61a69406140bfa9d0e1cf5919d99c7;hpb=debf798b1ed82053689d900670eb27fb2f1b4bd3;p=powerpc.git

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 4c14d4289b..367b7f6c06 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);
 }
@@ -106,7 +123,6 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
 	unsigned long oldflags = vma->vm_flags;
 	long nrpages = (end - start) >> PAGE_SHIFT;
 	unsigned long charged = 0;
-	pgprot_t newprot;
 	pgoff_t pgoff;
 	int error;
 
@@ -132,8 +148,6 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
 		}
 	}
 
-	newprot = protection_map[newflags & 0xf];
-
 	/*
 	 * First try to merge with previous and/or next vma.
 	 */
@@ -165,11 +179,16 @@ success:
 	 * held in write mode.
 	 */
 	vma->vm_flags = newflags;
-	vma->vm_page_prot = newprot;
+	vma->vm_page_prot = protection_map[newflags &
+		(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+	if (vma_wants_writenotify(vma))
+		vma->vm_page_prot = protection_map[newflags &
+			(VM_READ|VM_WRITE|VM_EXEC)];
+
 	if (is_vm_hugetlb_page(vma))
-		hugetlb_change_protection(vma, start, end, newprot);
+		hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
 	else
-		change_protection(vma, start, end, newprot);
+		change_protection(vma, start, end, vma->vm_page_prot);
 	vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
 	vm_stat_account(mm, newflags, vma->vm_file, nrpages);
 	return 0;
@@ -205,8 +224,7 @@ sys_mprotect(unsigned long start, size_t len, unsigned long prot)
 	/*
 	 * Does the application expect PROT_READ to imply PROT_EXEC:
 	 */
-	if (unlikely((prot & PROT_READ) &&
-			(current->personality & READ_IMPLIES_EXEC)))
+	if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
 		prot |= PROT_EXEC;
 
 	vm_flags = calc_vm_prot_bits(prot);