mm: replace get_user_pages() write/force parameters with gup_flags

This removes the 'write' and 'force' from get_user_pages() and replaces
them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers
as use of this flag can result in surprising behaviour (and hence bugs)
within the mm subsystem.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 9 deletions

diff --git a/mm/gup.c b/mm/gup.c
index 3cfb55ef0cf4..bbc2e76cdd77 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -987,18 +987,12 @@ EXPORT_SYMBOL(get_user_pages_remote);
  * obviously don't pass FOLL_REMOTE in here.
  */
 long get_user_pages(unsigned long start, unsigned long nr_pages,
-                int write, int force, struct page **pages,
+                unsigned int gup_flags, struct page **pages,
                 struct vm_area_struct **vmas)
 {
-        unsigned int flags = FOLL_TOUCH;
-
-        if (write)
-                flags |= FOLL_WRITE;
-        if (force)
-                flags |= FOLL_FORCE;
-
         return __get_user_pages_locked(current, current->mm, start, nr_pages,
-                                       pages, vmas, NULL, false, flags);
+                                       pages, vmas, NULL, false,
+                                       gup_flags | FOLL_TOUCH);
 }
 EXPORT_SYMBOL(get_user_pages);