From 4090e2170dd970281d87265bcb648726f0785aee Mon Sep 17 00:00:00 2001
From: Mark Johnston <markj@FreeBSD.org>
Date: Mon, 7 Oct 2019 23:31:17 +0000
Subject: [PATCH] Assert that the PGA_{WRITEABLE,EXECUTABLE} flags do not leak.

Reviewed by:	alc, kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D21783
---
 sys/vm/vm_page.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index bc1e9be7a2f..efd1812c8cc 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -3546,12 +3546,15 @@ vm_page_free_prep(vm_page_t m)
 			    m, i, (uintmax_t)*p));
 	}
 #endif
-	if ((m->oflags & VPO_UNMANAGED) == 0)
+	if ((m->oflags & VPO_UNMANAGED) == 0) {
 		KASSERT(!pmap_page_is_mapped(m),
 		    ("vm_page_free_prep: freeing mapped page %p", m));
-	else
+		KASSERT((m->aflags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0,
+		    ("vm_page_free_prep: mapping flags set in page %p", m));
+	} else {
 		KASSERT(m->queue == PQ_NONE,
 		    ("vm_page_free_prep: unmanaged page %p is queued", m));
+	}
 	VM_CNT_INC(v_tfree);
 
 	if (vm_page_sbusied(m))