From fd0be988cba4c3206bbc13c61342880048d68d07 Mon Sep 17 00:00:00 2001
From: Mark Johnston <markj@FreeBSD.org>
Date: Sat, 18 May 2019 14:19:23 +0000
Subject: [PATCH] Update the DIAGNOSTIC-only vmem_check_sanity() after r347949.

Cursor tags are special and shouldn't be subject to the existing checks.

Reported by:	kib, David Wolfskill
MFC with:	r347949
---
 sys/kern/subr_vmem.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sys/kern/subr_vmem.c b/sys/kern/subr_vmem.c
index 3a7f4f9c8d31..0c8421d9d824 100644
--- a/sys/kern/subr_vmem.c
+++ b/sys/kern/subr_vmem.c
@@ -1738,10 +1738,20 @@ vmem_check_sanity(vmem_t *vm)
 		}
 	}
 	TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
+		if (bt->bt_type == BT_TYPE_CURSOR) {
+			if (bt->bt_start != 0 || bt->bt_size != 0) {
+				printf("corrupted cursor\n");
+				return false;
+			}
+			continue;
+		}
 		TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
 			if (bt == bt2) {
 				continue;
 			}
+			if (bt2->bt_type == BT_TYPE_CURSOR) {
+				continue;
+			}
 			if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
 				continue;
 			}