[PATCH] mm/mmap: Don't unlock VMAs in remap_file_pages()

From: Liam R. Howlett
Date: Tue Dec 15 2020 - 09:14:09 EST


do_mmap() will unlock the necessary VMAs. There is also a bug in the
loop which will evaluate as false and not unlock any VMAs anyways.

Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
mm/mmap.c | 19 -------------------
1 file changed, 19 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 5c8b4485860de..008adf20611e5 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3025,25 +3025,6 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,

flags &= MAP_NONBLOCK;
flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE;
- if (vma->vm_flags & VM_LOCKED) {
- struct vm_area_struct *tmp;
- flags |= MAP_LOCKED;
-
- /* drop PG_Mlocked flag for over-mapped range */
- for (tmp = vma; tmp->vm_start >= start + size;
- tmp = tmp->vm_next) {
- /*
- * Split pmd and munlock page on the border
- * of the range.
- */
- vma_adjust_trans_huge(tmp, start, start + size, 0);
-
- munlock_vma_pages_range(tmp,
- max(tmp->vm_start, start),
- min(tmp->vm_end, start + size));
- }
- }
-
file = get_file(vma->vm_file);
ret = do_mmap(vma->vm_file, start, size,
prot, flags, pgoff, &populate, NULL);
--
2.28.0