From aea972f1c099519d2a6c25e8ab0ac69486b22961 Mon Sep 17 00:00:00 2001
From: deraadt <deraadt@openbsd.org>
Date: Mon, 13 Feb 2023 14:51:49 +0000
Subject: [PATCH] Upon fork, copy the copyin_check structure to the new map,
 otherwise the xonly rules are not applied a child.  This was due to the same
 misunderstanding as with msyscall a few days ago. ok guenther kettenis

---
 sys/uvm/uvm_map.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index 7ee39c71838..620cece4f56 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.c,v 1.310 2023/02/11 21:11:37 deraadt Exp $	*/
+/*	$OpenBSD: uvm_map.c,v 1.311 2023/02/13 14:51:49 deraadt Exp $	*/
 /*	$NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $	*/
 
 /*
@@ -3983,6 +3983,14 @@ uvmspace_fork(struct process *pr)
 		}
 	}
 	new_map->flags |= old_map->flags & VM_MAP_SYSCALL_ONCE;
+#ifdef PMAP_CHECK_COPYIN
+	if (PMAP_CHECK_COPYIN) {
+		memcpy(&new_map->check_copyin, &old_map->check_copyin,
+		    sizeof(new_map->check_copyin));
+		membar_producer();
+		new_map->check_copyin_count = old_map->check_copyin_count;
+	}
+#endif
 
 	vm_map_unlock(old_map);
 	vm_map_unlock(new_map);
-- 
2.20.1