[src/netbsd-7]: src/sys/arch Pull up following revision(s) (requested by maxv...

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

details:   https://anonhg.NetBSD.org/src/rev/c828fc8f3fee
branches:  netbsd-7
changeset: 451064:c828fc8f3fee
user:      martin <martin%NetBSD.org@localhost>
date:      Sun May 05 08:48:13 2019 +0000

description:
Pull up following revision(s) (requested by maxv in ticket #1693):

        sys/arch/amd64/amd64/copy.S: revision 1.33
        sys/arch/i386/i386/copy.S: revision 1.31

Hum. Fix a potentially catastrophic bug: kcopy() sets DF=1 if the areas
overlap, but doesn't clear it if the copy faults. If this happens, we
return to the caller with DF=1, and each future memory copy will be
backwards.

I wonder if there really are places where kcopy() is called with
overlapping areas.

diffstat:

 sys/arch/amd64/amd64/copy.S |  3 ++-
 sys/arch/i386/i386/copy.S   |  5 +++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diffs (43 lines):

diff -r 033a58a5f83f -r c828fc8f3fee sys/arch/amd64/amd64/copy.S
--- a/sys/arch/amd64/amd64/copy.S       Wed May 01 09:50:53 2019 +0000
+++ b/sys/arch/amd64/amd64/copy.S       Sun May 05 08:48:13 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: copy.S,v 1.18.34.1 2016/12/24 04:07:25 snj Exp $       */
+/*     $NetBSD: copy.S,v 1.18.34.2 2019/05/05 08:48:13 martin Exp $    */
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -233,6 +233,7 @@
  */
 
 NENTRY(kcopy_fault)
+       cld
        ret
 
 NENTRY(copy_fault)
diff -r 033a58a5f83f -r c828fc8f3fee sys/arch/i386/i386/copy.S
--- a/sys/arch/i386/i386/copy.S Wed May 01 09:50:53 2019 +0000
+++ b/sys/arch/i386/i386/copy.S Sun May 05 08:48:13 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: copy.S,v 1.23 2014/01/10 16:47:07 pedro Exp $  */
+/*     $NetBSD: copy.S,v 1.23.4.1 2019/05/05 08:48:13 martin Exp $     */
 /*     NetBSD: locore.S,v 1.34 2005/04/01 11:59:31 yamt Exp $  */
 
 /*-
@@ -65,7 +65,7 @@
  */
 
 #include <machine/asm.h>
-__KERNEL_RCSID(0, "$NetBSD: copy.S,v 1.23 2014/01/10 16:47:07 pedro Exp $");
+__KERNEL_RCSID(0, "$NetBSD: copy.S,v 1.23.4.1 2019/05/05 08:48:13 martin Exp $");
 
 #include "assym.h"
 
@@ -308,6 +308,7 @@
  */
 /* LINTSTUB: Ignore */
 NENTRY(kcopy_fault)
+       cld
        popl    %edi
        popl    %esi
        ret