mm/gup: Let __get_user_pages_locked() return -EINTR for fatal signal

__get_user_pages_locked() will return 0 instead of -EINTR after commit
4426e945df588 ("mm/gup: allow VM_FAULT_RETRY for multiple times") which
added extra code to allow gup detect fatal signal faster.

Restore the original -EINTR behavior.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 4426e945df58 ("mm/gup: allow VM_FAULT_RETRY for multiple times")
Reported-by: syzbot+3be1a33f04dc782e9fd5@syzkaller.appspotmail.com
Signed-off-by: Hillf Danton <hdanton@sina.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/gup.c b/mm/gup.c
index afce0bc47e70124d20947b569e8877f1396f9c1a..6076df8e04a4e74dbb1405aa0e28ec9c72b59c4b 100644 (file)
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1326,8 +1326,11 @@ retry:
                 * start trying again otherwise it can loop forever.
                 */
 
-               if (fatal_signal_pending(current))
+               if (fatal_signal_pending(current)) {
+                       if (!pages_done)
+                               pages_done = -EINTR;
                        break;
+               }
 
                ret = down_read_killable(&mm->mmap_sem);
                if (ret) {