[src/netbsd-8]: src/sys/arch Pull up following revision(s) (requested by maxv...

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

details:   https://anonhg.NetBSD.org/src/rev/6e9e6f34d96e
branches:  netbsd-8
changeset: 451062:6e9e6f34d96e
user:      martin <martin%NetBSD.org@localhost>
date:      Sun May 05 08:34:16 2019 +0000

description:
Pull up following revision(s) (requested by maxv in ticket #1257):

        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 e7239b4bc2f1 -r 6e9e6f34d96e sys/arch/amd64/amd64/copy.S
--- a/sys/arch/amd64/amd64/copy.S       Sun May 05 08:26:23 2019 +0000
+++ b/sys/arch/amd64/amd64/copy.S       Sun May 05 08:34:16 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: copy.S,v 1.20.10.3 2018/04/14 10:11:49 martin Exp $    */
+/*     $NetBSD: copy.S,v 1.20.10.4 2019/05/05 08:34:16 martin Exp $    */
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -242,6 +242,7 @@
 END(copy_efault)
 
 NENTRY(kcopy_fault)
+       cld
        ret
 END(kcopy_fault)
 
diff -r e7239b4bc2f1 -r 6e9e6f34d96e sys/arch/i386/i386/copy.S
--- a/sys/arch/i386/i386/copy.S Sun May 05 08:26:23 2019 +0000
+++ b/sys/arch/i386/i386/copy.S Sun May 05 08:34:16 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: copy.S,v 1.25.8.1 2018/02/04 12:40:31 martin Exp $     */
+/*     $NetBSD: copy.S,v 1.25.8.2 2019/05/05 08:34:16 martin Exp $     */
 
 /*
  * Copyright (c) 1998, 2000, 2004, 2008 The NetBSD Foundation, Inc.
@@ -64,7 +64,7 @@
  */
 
 #include <machine/asm.h>
-__KERNEL_RCSID(0, "$NetBSD: copy.S,v 1.25.8.1 2018/02/04 12:40:31 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: copy.S,v 1.25.8.2 2019/05/05 08:34:16 martin Exp $");
 
 #include "assym.h"
 
@@ -305,6 +305,7 @@
  */
 
 NENTRY(kcopy_fault)
+       cld
        popl    %edi
        popl    %esi
        ret