mm: fix find_vma_prev

[deliverable/linux.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 09ce2cae07ca3c092507b9f5727cd8ac61967317..da15a79b1441b665b0e4b962eea38a92407018fd 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1608,7 +1608,6 @@ EXPORT_SYMBOL(find_vma);
 
 /*
  * Same as find_vma, but also return a pointer to the previous VMA in *pprev.
- * Note: pprev is set to NULL when return value is NULL.
  */
 struct vm_area_struct *
 find_vma_prev(struct mm_struct *mm, unsigned long addr,
@@ -1617,7 +1616,16 @@ find_vma_prev(struct mm_struct *mm, unsigned long addr,
        struct vm_area_struct *vma;
 
        vma = find_vma(mm, addr);
-       *pprev = vma ? vma->vm_prev : NULL;
+       if (vma) {
+               *pprev = vma->vm_prev;
+       } else {
+               struct rb_node *rb_node = mm->mm_rb.rb_node;
+               *pprev = NULL;
+               while (rb_node) {
+                       *pprev = rb_entry(rb_node, struct vm_area_struct, vm_rb);
+                       rb_node = rb_node->rb_right;
+               }
+       }
        return vma;
 }