move_vma() can't just return if f_op->mremap() fails, we should
unmap the new vma like we do if move_page_tables() fails. To avoid
the code duplication this patch moves the "move entries back" under
the new "if (err)" branch.

Signed-off-by: Oleg Nesterov <[email protected]>
---
 mm/mremap.c |   15 +++++++--------
 1 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/mm/mremap.c b/mm/mremap.c
index 034e2d3..a6306bc 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -275,6 +275,12 @@ static unsigned long move_vma(struct vm_area_struct *vma,
        moved_len = move_page_tables(vma, old_addr, new_vma, new_addr, old_len,
                                     need_rmap_locks);
        if (moved_len < old_len) {
+               err = -ENOMEM;
+       } else if (vma->vm_file && vma->vm_file->f_op->mremap) {
+               err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
+       }
+
+       if (unlikely(err)) {
                /*
                 * On error, move entries back from new area to old,
                 * which will succeed since page tables still there,
@@ -285,14 +291,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
                vma = new_vma;
                old_len = new_len;
                old_addr = new_addr;
-               new_addr = -ENOMEM;
-       } else if (vma->vm_file && vma->vm_file->f_op->mremap) {
-               err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
-               if (err < 0) {
-                       move_page_tables(new_vma, new_addr, vma, old_addr,
-                                        moved_len, true);
-                       return err;
-               }
+               new_addr = err;
        }
 
        /* Conceal VM_ACCOUNT so old reservation is not undone */
-- 
1.5.5.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to