[src/trunk]: src/sys/arch/x86/x86 PTP pages are zeroed before free again.

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details:   https://anonhg.NetBSD.org/src/rev/7ed8f939b375
branches:  trunk
changeset: 932784:7ed8f939b375
user:      ad <ad%NetBSD.org@localhost>
date:      Fri May 15 22:22:44 2020 +0000

description:
PTP pages are zeroed before free again.

diffstat:

 sys/arch/x86/x86/pmap.c |  9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diffs (30 lines):

diff -r c7bbd12413c1 -r 7ed8f939b375 sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c   Fri May 15 22:22:06 2020 +0000
+++ b/sys/arch/x86/x86/pmap.c   Fri May 15 22:22:44 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.391 2020/05/15 22:22:06 ad Exp $    */
+/*     $NetBSD: pmap.c,v 1.392 2020/05/15 22:22:44 ad Exp $    */
 
 /*
  * Copyright (c) 2008, 2010, 2016, 2017, 2019, 2020 The NetBSD Foundation, Inc.
@@ -130,7 +130,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.391 2020/05/15 22:22:06 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.392 2020/05/15 22:22:44 ad Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -5433,10 +5433,7 @@
                uvm_pagerealloc(ptp, NULL, 0);
                PMAP_DUMMY_UNLOCK(pmap);
 
-               /*
-                * XXX for PTPs freed by pmap_remove_ptes() but not
-                * pmap_zap_ptp(), we could mark them PG_ZERO.
-                */
+               ptp->flags |= PG_ZERO;
                uvm_pagefree(ptp);
        }
        while ((pvp = LIST_FIRST(&pmap->pm_pvp_full)) != NULL) {