Tue Mar 6 08:45:59 2018 UTC ()

Also pull up r1.267, requested by mrg in ticket #593: avoid a NULL pointer
deref and simplify.


(martin)

diff -r1.245.6.2 -r1.245.6.3 src/sys/arch/x86/x86/pmap.c

--- src/sys/arch/x86/x86/pmap.c 2018/02/27 09:07:33	1.245.6.2
+++ src/sys/arch/x86/x86/pmap.c 2018/03/06 08:45:59	1.245.6.3

 @@ -1,14 +1,14 @@
-/*	$NetBSD: pmap.c,v 1.245.6.2 2018/02/27 09:07:33 martin Exp $	*/
+/*	$NetBSD: pmap.c,v 1.245.6.3 2018/03/06 08:45:59 martin Exp $	*/
 /*-
  * Copyright (c) 2008, 2010, 2016, 2017 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Andrew Doran, and by Maxime Villard.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
 @@ -161,27 +161,27 @@
  *     Hibler/Jolitz pmap, as modified for FreeBSD by John S. Dyson
  *     and David Greenman.
+ *
  * [3] the Mach pmap.   this pmap, from CMU, seems to have migrated
  *     between several processors.   the VAX version was done by
  *     Avadis Tevanian, Jr., and Michael Wayne Young.    the i386
  *     version was done by Lance Berc, Mike Kupfer, Bob Baron,
  *     David Golub, and Richard Draves.    the alpha version was
  *     done by Alessandro Forin (CMU/Mach) and Chris Demetriou
  *     (NetBSD/alpha).
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.245.6.2 2018/02/27 09:07:33 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.245.6.3 2018/03/06 08:45:59 martin Exp $");
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
 #include "opt_multiprocessor.h"
 #include "opt_xen.h"
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>
 #include <sys/pool.h>
 #include <sys/kernel.h>
 #include <sys/atomic.h>
 #include <sys/cpu.h>
 @@ -1727,28 +1727,28 @@ pmap_vpage_cpu_init(struct cpu_info *ci)
  * p v _ e n t r y   f u n c t i o n s
  */
 static bool
 pmap_pp_needs_pve(struct pmap_page *pp)
+{
 	/*
 	 * Adding a pv entry for this page only needs to allocate a pv_entry
 	 * structure if the page already has at least one pv entry,
 	 * since the first pv entry is stored in the pmap_page.
 	 */
-	return (pp->pp_flags & PP_EMBEDDED) != 0 ||
+	return pp && ((pp->pp_flags & PP_EMBEDDED) != 0 ||
-		!LIST_EMPTY(&pp->pp_head.pvh_list);
+	    !LIST_EMPTY(&pp->pp_head.pvh_list));
+}
 /*
  * pmap_free_pvs: free a list of pv_entrys
  */
 static void
 pmap_free_pvs(struct pv_entry *pve)
+{
 	struct pv_entry *next;
 	for ( /* null */ ; pve != NULL ; pve = next) {
 		next = pve->pve_next;
 @@ -4113,27 +4113,27 @@ pmap_enter_ma(struct pmap *pmap, vaddr_t
 		npte |= PG_PVLIST;
 	} else {
 		new_pp = NULL;
+	}
 	/*
 	 * Try to get pves now if we might need them.
 	 * Keep going even if we fail, since we will not actually need them
 	 * if we are just changing the permissions on an existing mapping,
 	 * but we won't know if that's the case until later.
 	 */
 	bool needpves = pmap_pp_needs_pve(new_pp);
-	if (new_pp && needpves) {
+	if (needpves) {
 		new_pve = pool_cache_get(&pmap_pv_cache, PR_NOWAIT);
 		new_sparepve = pool_cache_get(&pmap_pv_cache, PR_NOWAIT);
 	} else {
 		new_pve = NULL;
 		new_sparepve = NULL;
+	}
 	kpreempt_disable();
 	pmap_map_ptes(pmap, &pmap2, &ptes, &pdes);	/* locks pmap */
 	if (pmap == pmap_kernel()) {
 		ptp = NULL;
 	} else {
 		ptp = pmap_get_ptp(pmap, va, pdes, flags);