fix pgoff in "have to relocate" case of mremap()

Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/mm/mremap.c b/mm/mremap.c
index 84efffb..bbbbbf5 100644 (file)
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -495,7 +495,9 @@ unsigned long do_mremap(unsigned long addr,
                        map_flags |= MAP_SHARED;
 
                new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
-                                       vma->vm_pgoff, map_flags);
+                                       vma->vm_pgoff +
+                                       ((addr - vma->vm_start) >> PAGE_SHIFT),
+                                       map_flags);
                if (new_addr & ~PAGE_MASK) {
                        ret = new_addr;
                        goto out;