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

mainline inclusion
from mainline-v5.7-rc1
commit ae46d2aa
category: bugfix
bugzilla: 47439
CVE: NA
---------------------------

__get_user_pages_locked() will return 0 instead of -EINTR after commit
4426e945 ("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: 4426e945 ("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>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Reviewed-by: Kefeng  Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>