mm: nommu: check the vma list when unmapping file-mapped vma

Now we have the sorted vma list, use it in do_munmap() to check that we
have an exact match.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 4 deletions

diff --git a/mm/nommu.c b/mm/nommu.c
index e5318f8efde5..0563fd9003df 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1635,7 +1635,6 @@ static int shrink_vma(struct mm_struct *mm,
 int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
 {
         struct vm_area_struct *vma;
-        struct rb_node *rb;
         unsigned long end = start + len;
         int ret;
 
@@ -1668,9 +1667,8 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
                         }
                         if (end == vma->vm_end)
                                 goto erase_whole_vma;
-                        rb = rb_next(&vma->vm_rb);
-                        vma = rb_entry(rb, struct vm_area_struct, vm_rb);
-                } while (rb);
+                        vma = vma->vm_next;
+                } while (vma);
                 kleave(" = -EINVAL [split file]");
                 return -EINVAL;
         } else {