1 files changed, 16 insertions, 22 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index 5afce48ce339..0b16cb4c517b 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -680,9 +680,9 @@ static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
  */
 static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
 {
-	struct vm_area_struct *pvma, **pp, *next;
+	struct vm_area_struct *pvma, *prev;
 	struct address_space *mapping;
-	struct rb_node **p, *parent;
+	struct rb_node **p, *parent, *rb_prev;
 
 	kenter(",%p", vma);
 
@@ -703,7 +703,7 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
 	}
 
 	/* add the VMA to the tree */
-	parent = NULL;
+	parent = rb_prev = NULL;
 	p = &mm->mm_rb.rb_node;
 	while (*p) {
 		parent = *p;
@@ -713,17 +713,20 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
 		 * (the latter is necessary as we may get identical VMAs) */
 		if (vma->vm_start < pvma->vm_start)
 			p = &(*p)->rb_left;
-		else if (vma->vm_start > pvma->vm_start)
+		else if (vma->vm_start > pvma->vm_start) {
+			rb_prev = parent;
 			p = &(*p)->rb_right;
-		else if (vma->vm_end < pvma->vm_end)
+		} else if (vma->vm_end < pvma->vm_end)
 			p = &(*p)->rb_left;
-		else if (vma->vm_end > pvma->vm_end)
+		else if (vma->vm_end > pvma->vm_end) {
+			rb_prev = parent;
 			p = &(*p)->rb_right;
-		else if (vma < pvma)
+		} else if (vma < pvma)
 			p = &(*p)->rb_left;
-		else if (vma > pvma)
+		else if (vma > pvma) {
+			rb_prev = parent;
 			p = &(*p)->rb_right;
-		else
+		} else
 			BUG();
 	}
 
@@ -731,20 +734,11 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
 	rb_insert_color(&vma->vm_rb, &mm->mm_rb);
 
 	/* add VMA to the VMA list also */
-	for (pp = &mm->mmap; (pvma = *pp); pp = &(*pp)->vm_next) {
-		if (pvma->vm_start > vma->vm_start)
-			break;
-		if (pvma->vm_start < vma->vm_start)
-			continue;
-		if (pvma->vm_end < vma->vm_end)
-			break;
-	}
+	prev = NULL;
+	if (rb_prev)
+		prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb);
 
-	next = *pp;
-	*pp = vma;
-	vma->vm_next = next;
-	if (next)
-		next->vm_prev = vma;
+	__vma_link_list(mm, vma, prev, parent);
 }
 
 /*