From faa3fd222aeef0cf51bb55ec3192e8a41b177c85 Mon Sep 17 00:00:00 2001
From: Andrew Turner <andrew@FreeBSD.org>
Date: Thu, 1 Feb 2018 14:26:26 +0000
Subject: [PATCH] Only promote userspace mappings to superpages. This was
 dropped in r328510, however due to the break-before-make requirement on arm64
 is is currently unsafe to promote kernel pages.

Sponsored by:	DARPA, AFRL
---
 sys/arm64/arm64/pmap.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index 04f45a93147..64efc54eb97 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -3076,12 +3076,13 @@ validate:
 	}
 
 #if VM_NRESERVLEVEL > 0
-		if ((mpte == NULL || mpte->wire_count == NL3PG) &&
-		    pmap_superpages_enabled() &&
-		    (m->flags & PG_FICTITIOUS) == 0 &&
-		    vm_reserv_level_iffullpop(m) == 0) {
-			pmap_promote_l2(pmap, pde, va, &lock);
-		}
+	if (pmap != pmap_kernel() &&
+	    (mpte == NULL || mpte->wire_count == NL3PG) &&
+	    pmap_superpages_enabled() &&
+	    (m->flags & PG_FICTITIOUS) == 0 &&
+	    vm_reserv_level_iffullpop(m) == 0) {
+		pmap_promote_l2(pmap, pde, va, &lock);
+	}
 #endif
 
 	if (lock != NULL)