[src/trunk]: src/sys/arch/x86/x86 Operation pmap_pp_clear_attrs() may remove ...

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

details:   https://anonhg.NetBSD.org/src/rev/524ddbbe04d8
branches:  trunk
changeset: 343245:524ddbbe04d8
user:      hannken <hannken%NetBSD.org@localhost>
date:      Tue Jan 26 14:34:50 2016 +0000

description:
Operation pmap_pp_clear_attrs() may remove the "used" attribute from a page
that is still cached in the TLB of other CPUs.

Call pmap_tlb_shootnow() here before enabling preemption to clear the
TLB entries on other CPUs.

Should prevent tmpfs data corruption under load.

Ok: Chuck Silvers

diffstat:

 sys/arch/x86/x86/pmap.c |  5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diffs (26 lines):

diff -r 03f6da42e7f0 -r 524ddbbe04d8 sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c   Tue Jan 26 14:08:58 2016 +0000
+++ b/sys/arch/x86/x86/pmap.c   Tue Jan 26 14:34:50 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.189 2015/11/11 08:20:22 skrll Exp $ */
+/*     $NetBSD: pmap.c,v 1.190 2016/01/26 14:34:50 hannken Exp $       */
 
 /*-
  * Copyright (c) 2008, 2010 The NetBSD Foundation, Inc.
@@ -171,7 +171,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.189 2015/11/11 08:20:22 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.190 2016/01/26 14:34:50 hannken Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -3746,6 +3746,7 @@
        }
        result = pp->pp_attrs & clearbits;
        pp->pp_attrs &= ~clearbits;
+       pmap_tlb_shootnow();
        kpreempt_enable();
 
        return result != 0;