[src/trunk]: src/sys/arch/mips/mips Fix PR/51288 reproducable panic on evbmip...

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d17236f8efae
branches:  trunk
changeset: 346148:d17236f8efae
user:      skrll <skrll%NetBSD.org@localhost>
date:      Tue Jun 28 09:31:15 2016 +0000

description:
Fix PR/51288 reproducable panic on evbmips64-eb (erlite)

pmap_page_remove from the previous change neglected to terminate the pv
list correctly when it started with an initial unmanaged mapping and
subsequent managed mappings.  Fix this.

diffstat:

 sys/arch/mips/mips/pmap.c |  15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diffs (55 lines):

diff -r 62aaabebeca0 -r d17236f8efae sys/arch/mips/mips/pmap.c
--- a/sys/arch/mips/mips/pmap.c Tue Jun 28 09:27:26 2016 +0000
+++ b/sys/arch/mips/mips/pmap.c Tue Jun 28 09:31:15 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.221 2016/06/27 07:12:18 skrll Exp $ */
+/*     $NetBSD: pmap.c,v 1.222 2016/06/28 09:31:15 skrll Exp $ */
 
 /*-
  * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.221 2016/06/27 07:12:18 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.222 2016/06/28 09:31:15 skrll Exp $");
 
 /*
  *     Manages physical address maps.
@@ -2327,6 +2327,11 @@
                                    __func__, pv, pv->pv_pmap, pv->pv_va);
                        }
 #endif
+                       KASSERT(pv->pv_pmap == pmap_kernel());
+
+                       /* Assume no more - it'll get fixed if there are */
+                       pv->pv_next = NULL;
+
                        /*
                         * pvp is non-null when we already have a PV_KENTER
                         * pv in pvh_first; otherwise we haven't seen a
@@ -2342,14 +2347,12 @@
                        } else {
                                pv_entry_t fpv = &md->pvh_first;
                                *fpv = *pv;
+                               KASSERT(fpv->pv_pmap == pmap_kernel());
                        }
-                       /* Assume no more - it'll get fixed if there are */
-                       pv->pv_next = NULL;
                        pvp = pv;
                        continue;
                }
 
-
                const pmap_t pmap = pv->pv_pmap;
                vaddr_t va = trunc_page(pv->pv_va);
                pt_entry_t *pte = pmap_pte(pmap, va);
@@ -2385,6 +2388,8 @@
                 * free it.
                 */
                if (pvp) {
+                       KASSERT(pvp->pv_pmap == pmap_kernel());
+                       KASSERT(pvp->pv_next == NULL);
                        pmap_pv_free(pv);
                } else {
                        pv->pv_pmap = NULL;