X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=mm%2Fmprotect.c;h=c43d557941f807471a3c39963f77a8ba3d32dd8a;hb=a5338093bfb462256f70f3450c08f73e59543e26;hp=2c51c79c8a698189c53380352f9770d234d0772c;hpb=1ad9f620c3a22fa800489455ce517c29e576934e;p=firefly-linux-kernel-4.4.55.git

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 2c51c79c8a69..c43d557941f8 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -140,9 +140,11 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 		pgprot_t newprot, int dirty_accountable, int prot_numa)
 {
 	pmd_t *pmd;
+	struct mm_struct *mm = vma->vm_mm;
 	unsigned long next;
 	unsigned long pages = 0;
 	unsigned long nr_huge_updates = 0;
+	unsigned long mni_start = 0;
 
 	pmd = pmd_offset(pud, addr);
 	do {
@@ -151,6 +153,13 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 		next = pmd_addr_end(addr, end);
 		if (!pmd_trans_huge(*pmd) && pmd_none_or_clear_bad(pmd))
 			continue;
+
+		/* invoke the mmu notifier if the pmd is populated */
+		if (!mni_start) {
+			mni_start = addr;
+			mmu_notifier_invalidate_range_start(mm, mni_start, end);
+		}
+
 		if (pmd_trans_huge(*pmd)) {
 			if (next - addr != HPAGE_PMD_SIZE)
 				split_huge_page_pmd(vma, addr, pmd);
@@ -175,6 +184,9 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
 		pages += this_pages;
 	} while (pmd++, addr = next, addr != end);
 
+	if (mni_start)
+		mmu_notifier_invalidate_range_end(mm, mni_start, end);
+
 	if (nr_huge_updates)
 		count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates);
 	return pages;
@@ -234,15 +246,12 @@ unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
 		       unsigned long end, pgprot_t newprot,
 		       int dirty_accountable, int prot_numa)
 {
-	struct mm_struct *mm = vma->vm_mm;
 	unsigned long pages;
 
-	mmu_notifier_invalidate_range_start(mm, start, end);
 	if (is_vm_hugetlb_page(vma))
 		pages = hugetlb_change_protection(vma, start, end, newprot);
 	else
 		pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa);
-	mmu_notifier_invalidate_range_end(mm, start, end);
 
 	return pages;
 }