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[src/trunk]: src/sys/arch/alpha/alpha Pay attention to "access_type" in pmap_...
details: https://anonhg.NetBSD.org/src/rev/d5727acf1e5f
branches: trunk
changeset: 467667:d5727acf1e5f
user: thorpej <thorpej%NetBSD.org@localhost>
date: Sat Mar 27 02:48:32 1999 +0000
description:
Pay attention to "access_type" in pmap_enter().
diffstat:
sys/arch/alpha/alpha/pmap.c | 18 ++++++++++++++++--
1 files changed, 16 insertions(+), 2 deletions(-)
diffs (39 lines):
diff -r 5afa9ed5330d -r d5727acf1e5f sys/arch/alpha/alpha/pmap.c
--- a/sys/arch/alpha/alpha/pmap.c Sat Mar 27 01:44:37 1999 +0000
+++ b/sys/arch/alpha/alpha/pmap.c Sat Mar 27 02:48:32 1999 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.86 1999/03/26 23:41:26 mycroft Exp $ */
+/* $NetBSD: pmap.c,v 1.87 1999/03/27 02:48:32 thorpej Exp $ */
/*-
* Copyright (c) 1998, 1999 The NetBSD Foundation, Inc.
@@ -155,7 +155,7 @@
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.86 1999/03/26 23:41:26 mycroft Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.87 1999/03/27 02:48:32 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -1774,6 +1774,20 @@
struct pv_head *pvh = pa_to_pvh(pa);
/*
+ * An obvious question here is why a page would be entered in
+ * response to a fault, but with permissions less than those
+ * requested. This can happen in the case of a copy-on-write
+ * page that's not currently mapped being accessed; the first
+ * fault will map the original page read-only, and another
+ * fault will be taken to do the copy and make it read-write.
+ */
+ access_type &= prot;
+ if (access_type & VM_PROT_WRITE)
+ pvh->pvh_attrs |= (PGA_REFERENCED|PGA_MODIFIED);
+ else if (access_type & VM_PROT_ALL)
+ pvh->pvh_attrs |= PGA_REFERENCED;
+
+ /*
* Set up referenced/modified emulation for new mapping.
*/
if ((pvh->pvh_attrs & PGA_REFERENCED) == 0)
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