[PATCH v2 06/13] mm/gup: add an assertion that the mmap lock is locked

[Jason Gunthorpe <jgg@xxxxxxxxxx>]

Since commit 5b78ed24e8ec ("mm/pagemap: add mmap_assert_locked()
annotations to find_vma*()") we already have this assertion, it is just
buried in find_vma():

 __get_user_pages_locked()
  __get_user_pages()
  find_extend_vma()
   find_vma()

Also check it at the top of __get_user_pages_locked() as a form of
documentation.

Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
 mm/gup.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/gup.c b/mm/gup.c
index 4c236fb83dcd3e..de1a5c64fdfdcf 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1360,6 +1360,8 @@ static __always_inline long __get_user_pages_locked(struct mm_struct *mm,
 		must_unlock = true;
 		*locked = 1;
 	}
+	else
+		mmap_assert_locked(mm);
 
 	if (flags & FOLL_PIN)
 		mm_set_has_pinned_flag(&mm->flags);
-- 
2.39.0