X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fmprotect.c;h=d0f6e7ce09f1ee88beabccff1b4025b585375062;hb=28dbc4b6a01fb579a9441c7b81e3d3413dc452df;hp=55227845abbe869f0aad75724f4d10c93b5a189f;hpb=3ed75eb8f1cd89565966599c4f77d2edb086d5b0;p=safe%2Fjmp%2Flinux-2.6

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 5522784..d0f6e7c 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -4,7 +4,7 @@
  *  (C) Copyright 1994 Linus Torvalds
  *  (C) Copyright 2002 Christoph Hellwig
  *
- *  Address space accounting code	<alan@redhat.com>
+ *  Address space accounting code	<alan@lxorguk.ukuu.org.uk>
  *  (C) Copyright 2002 Red Hat Inc, All Rights Reserved
  */
 
@@ -21,11 +21,20 @@
 #include <linux/syscalls.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
+#include <linux/mmu_notifier.h>
+#include <linux/migrate.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
+#ifndef pgprot_modify
+static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
+{
+	return newprot;
+}
+#endif
+
 static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
 		unsigned long addr, unsigned long end, pgprot_t newprot,
 		int dirty_accountable)
@@ -40,21 +49,18 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
 		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);
-#ifdef CONFIG_MIGRATION
-		} else if (!pte_file(oldpte)) {
+
+			ptep_modify_prot_commit(mm, addr, pte, ptent);
+		} else if (PAGE_MIGRATION && !pte_file(oldpte)) {
 			swp_entry_t entry = pte_to_swp_entry(oldpte);
 
 			if (is_write_migration_entry(entry)) {
@@ -66,9 +72,7 @@ static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
 				set_pte_at(mm, addr, pte,
 					swp_entry_to_pte(entry));
 			}
-#endif
 		}
-
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 	arch_leave_lazy_mmu_mode();
 	pte_unmap_unlock(pte - 1, ptl);
@@ -148,12 +152,10 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
 	 * 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;
@@ -192,16 +194,20 @@ success:
 	 * held in write mode.
 	 */
 	vma->vm_flags = newflags;
-	vma->vm_page_prot = vm_get_page_prot(newflags);
+	vma->vm_page_prot = pgprot_modify(vma->vm_page_prot,
+					  vm_get_page_prot(newflags));
+
 	if (vma_wants_writenotify(vma)) {
-		vma->vm_page_prot = vm_get_page_prot(newflags);
+		vma->vm_page_prot = vm_get_page_prot(newflags & ~VM_SHARED);
 		dirty_accountable = 1;
 	}
 
+	mmu_notifier_invalidate_range_start(mm, start, end);
 	if (is_vm_hugetlb_page(vma))
 		hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
 	else
 		change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable);
+	mmu_notifier_invalidate_range_end(mm, start, end);
 	vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
 	vm_stat_account(mm, newflags, vma->vm_file, nrpages);
 	return 0;
@@ -230,7 +236,7 @@ sys_mprotect(unsigned long start, size_t len, unsigned long prot)
 	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;