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

This removes the 'write' and 'force' from get_user_pages_remote() 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: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/mm/memory.c b/mm/memory.c
index fc1987dfd8cc..20a9adb7b36e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3873,6 +3873,10 @@ static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
 {
         struct vm_area_struct *vma;
         void *old_buf = buf;
+        unsigned int flags = FOLL_FORCE;
+
+        if (write)
+                flags |= FOLL_WRITE;
 
         down_read(&mm->mmap_sem);
         /* ignore errors, just check how much was successfully transferred */
@@ -3882,7 +3886,7 @@ static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
                 struct page *page = NULL;
 
                 ret = get_user_pages_remote(tsk, mm, addr, 1,
-                                write, 1, &page, &vma);
+                                flags, &page, &vma);
                 if (ret <= 0) {
 #ifndef CONFIG_HAVE_IOREMAP_PROT
                         break;