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 <[email protected]>
Acked-by: Paolo Bonzini <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Lorenzo Stoakes 2016-10-13 01:20:12 +01:00 • committed by Linus Torvalds
commit d4944b0ece
6 changed files with 34 additions and 19 deletions

View file

@ -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);