From 5fe446d24aff4b9742cc2358014eb92eaa34ac38 Mon Sep 17 00:00:00 2001
From: Peter Xu <peterx@redhat.com>
Date: Mon, 6 Apr 2020 20:06:29 -0700
Subject: [PATCH] BACKPORT: userfaultfd: wp: declare _UFFDIO_WRITEPROTECT
 conditionally

Only declare _UFFDIO_WRITEPROTECT if the user specified
UFFDIO_REGISTER_MODE_WP and if all the checks passed.  Then when the user
registers regions with shmem/hugetlbfs we won't expose the new ioctl to
them.  Even with complete anonymous memory range, we'll only expose the
new WP ioctl bit if the register mode has MODE_WP.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-18-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 14819305e09fe4fda546f0dfa12134c8e5366616)

[ Kalesh Singh - resolve conflicts in fs/userfaultfd.c ]

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Reported-by: kernel test robot <lkp@intel.com> [1]
[1] https://lore.kernel.org/r/202201170247.Cir3moOM-lkp@intel.com/

Bug: 160737021
Bug: 169683130
Change-Id: I4f205e642f5f0e5824a43303aab30626cce3ddcb
---
 fs/userfaultfd.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 1d0c0397907e..4a6719214dc4 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1530,9 +1530,7 @@ out_unlock:
 		 * userland which ioctls methods are guaranteed to
 		 * succeed on this range.
 		 */
-		if (put_user(basic_ioctls ? UFFD_API_RANGE_IOCTLS_BASIC :
-			     UFFD_API_RANGE_IOCTLS,
-			     &user_uffdio_register->ioctls))
+		if (put_user(ioctls_out, &user_uffdio_register->ioctls))
 			ret = -EFAULT;
 	}
 out: