[src/trunk]: src/sys/uvm/pmap When removing a page, make sure to clear its ex...

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

details:   https://anonhg.NetBSD.org/src/rev/9211aec6c525
branches:  trunk
changeset: 817937:9211aec6c525
user:      matt <matt%NetBSD.org@localhost>
date:      Fri Sep 16 17:27:09 2016 +0000

description:
When removing a page, make sure to clear its execness regardless of whether
the page is clean or dirty.  This fixes the problem of execpages leaking
into the freepage lists.

diffstat:

 sys/uvm/pmap/pmap.c |  16 +++++++++++-----
 1 files changed, 11 insertions(+), 5 deletions(-)

diffs (44 lines):

diff -r 70f52b010106 -r 9211aec6c525 sys/uvm/pmap/pmap.c
--- a/sys/uvm/pmap/pmap.c       Fri Sep 16 17:13:06 2016 +0000
+++ b/sys/uvm/pmap/pmap.c       Fri Sep 16 17:27:09 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.21 2016/08/20 20:09:47 mrg Exp $    */
+/*     $NetBSD: pmap.c,v 1.22 2016/09/16 17:27:09 matt Exp $   */
 
 /*-
  * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.21 2016/08/20 20:09:47 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.22 2016/09/16 17:27:09 matt Exp $");
 
 /*
  *     Manages physical address maps.
@@ -713,6 +713,15 @@
 
        UVMHIST_FUNC(__func__); UVMHIST_CALLED(pmaphist);
 
+       UVMHIST_LOG(pmapexechist, "pg %p (pa %#"PRIxPADDR")%s: %s",
+           pg, VM_PAGE_TO_PHYS(pg), " [page removed]", "execpage cleared");
+#ifdef PMAP_VIRTUAL_CACHE_ALIASES
+       pmap_page_clear_attributes(mdpg, VM_PAGEMD_EXECPAGE|VM_PAGEMD_UNCACHED);
+#else
+       pmap_page_clear_attributes(mdpg, VM_PAGEMD_EXECPAGE);
+#endif
+       PMAP_COUNT(exec_uncached_remove);
+
        pv_entry_t pv = &mdpg->mdpg_first;
        if (pv->pv_pmap == NULL) {
                VM_PAGEMD_PVLIST_UNLOCK(mdpg);
@@ -800,9 +809,6 @@
                }
        }
 
-#ifdef PMAP_VIRTUAL_CACHE_ALIASES
-       pmap_page_clear_attributes(mdpg, VM_PAGEMD_UNCACHED);
-#endif
        pmap_pvlist_check(mdpg);
        VM_PAGEMD_PVLIST_UNLOCK(mdpg);
        kpreempt_enable();