mm: remove write/force parameters from __get_user_pages_unlocked()

This removes the redundant 'write' and 'force' parameters from
__get_user_pages_unlocked() 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: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 8 deletions

diff --git a/mm/gup.c b/mm/gup.c
index 720eb9385204..e997f545b059 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -875,17 +875,11 @@ EXPORT_SYMBOL(get_user_pages_locked);
  */
 __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
 					       unsigned long start, unsigned long nr_pages,
-					       int write, int force, struct page **pages,
-					       unsigned int gup_flags)
+					       struct page **pages, unsigned int gup_flags)
 {
 	long ret;
 	int locked = 1;
 
-	if (write)
-		gup_flags |= FOLL_WRITE;
-	if (force)
-		gup_flags |= FOLL_FORCE;
-
 	down_read(&mm->mmap_sem);
 	ret = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, NULL,
 				      &locked, false, gup_flags);
@@ -915,8 +909,15 @@ EXPORT_SYMBOL(__get_user_pages_unlocked);
 long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
 			     int write, int force, struct page **pages)
 {
+	unsigned int flags = FOLL_TOUCH;
+
+	if (write)
+		flags |= FOLL_WRITE;
+	if (force)
+		flags |= FOLL_FORCE;
+
 	return __get_user_pages_unlocked(current, current->mm, start, nr_pages,
-					 write, force, pages, FOLL_TOUCH);
+					 pages, flags);
 }
 EXPORT_SYMBOL(get_user_pages_unlocked);