svn commit: r250151 - in stable: 6/sys/boot/i386/btx/btx 6/sys/boot/pc98/btx/btx 7/sys/boot/i386/btx/btx 7/sys/boot/pc98/btx/btx 8/sys/boot/i386/btx/btx 8/sys/boot/pc98/btx/btx 9/sys/boot/i386/btx/...

[Dimitry Andric]

Author: dim
Date: Wed May  1 18:06:53 2013
New Revision: 250151
URL: http://svnweb.freebsd.org/changeset/base/250151

Log:
  MFC r249846:
  
  When rebooting (exiting) from the BTX loader, make sure to restore the
  GDT from the correct segment, otherwise a triple fault would be caused.
  In some virtual environments (VMware, VirtualBox, etc) this could lead
  to a unhandled error or hang in the guest emulation software.
  
  Thanks to avg and jhb for a few hints in the right direction.
  
  Noticed by:	Jeremy Chadwick <jdc at koitsu.org> (and many others)

Modified:
  stable/6/sys/boot/i386/btx/btx/btx.S
  stable/6/sys/boot/pc98/btx/btx/btx.S
Directory Properties:
  stable/6/sys/   (props changed)

Changes in other areas also in this revision:
Modified:
  stable/7/sys/boot/i386/btx/btx/btx.S
  stable/7/sys/boot/pc98/btx/btx/btx.S
  stable/8/sys/boot/i386/btx/btx/btx.S
  stable/8/sys/boot/pc98/btx/btx/btx.S
  stable/9/sys/boot/i386/btx/btx/btx.S
  stable/9/sys/boot/pc98/btx/btx/btx.S
Directory Properties:
  stable/7/sys/   (props changed)
  stable/8/sys/   (props changed)
  stable/8/sys/boot/   (props changed)
  stable/9/sys/   (props changed)
  stable/9/sys/boot/   (props changed)

Modified: stable/6/sys/boot/i386/btx/btx/btx.S
==============================================================================
--- stable/6/sys/boot/i386/btx/btx/btx.S	Wed May  1 17:59:41 2013	(r250150)
+++ stable/6/sys/boot/i386/btx/btx/btx.S	Wed May  1 18:06:53 2013	(r250151)
@@ -246,7 +246,7 @@ exit:		cli				# Disable interrupts
 /*
  * Restore the GDT in case we caught a kernel trap.
  */
-		lgdt gdtdesc	 		# Set GDT
+		lgdt %cs:gdtdesc		# Set GDT
 /*
  * To 16 bits.
  */

Modified: stable/6/sys/boot/pc98/btx/btx/btx.S
==============================================================================
--- stable/6/sys/boot/pc98/btx/btx/btx.S	Wed May  1 17:59:41 2013	(r250150)
+++ stable/6/sys/boot/pc98/btx/btx/btx.S	Wed May  1 18:06:53 2013	(r250151)
@@ -246,7 +246,7 @@ exit:		cli				# Disable interrupts
 /*
  * Restore the GDT in case we caught a kernel trap.
  */
-		lgdt gdtdesc	 		# Set GDT
+		lgdt %cs:gdtdesc		# Set GDT
 /*
  * To 16 bits.
  */