alistair23-linux/arch/x86
Ian Campbell e68266b700 x86: xen: 64-bit kernel RPL should be 0
Under Xen 64 bit guests actually run their kernel in ring 3,
however the hypervisor takes care of squashing descriptor the
RPLs transparently (in order to allow them to continue to
differentiate between user and kernel space CS using the RPL).
Therefore the Xen paravirt backend should use RPL==0 instead of
1 (or 3). Using RPL==1 causes generic arch code to take
incorrect code paths because it uses "testl $3, <CS>, je foo"
type tests for a userspace CS and this considers 1==userspace.

This issue was previously masked because get_kernel_rpl() was
omitted when setting CS in kernel_thread(). This was fixed when
kernel_thread() was unified with 32 bit in
f443ff4201.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Christian Kujau <lists@nerdbynature.de>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1263377768-19600-2-git-send-email-ian.campbell@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-13 11:23:54 +01:00
..
boot Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2009-12-28 09:23:13 +01:00
configs
crypto
ia32 Unify sys_mmap* 2009-12-11 06:44:29 -05:00
include/asm x86: mce.h: Fix warning in header checks 2010-01-13 10:41:22 +01:00
kernel x86: kernel_thread() -- initialize SS to a known state 2010-01-13 11:23:45 +01:00
kvm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-12-14 09:58:24 -08:00
lguest
lib Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2009-12-28 09:23:13 +01:00
math-emu
mm x86, kmemcheck: Use KERN_WARNING for error reporting 2009-12-28 10:28:35 +01:00
oprofile
pci x86/pci: Intel ioh bus num reg accessing fix 2010-01-04 13:21:51 -08:00
power
tools Merge branch 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent 2009-12-28 09:23:13 +01:00
vdso
video
xen x86: xen: 64-bit kernel RPL should be 0 2010-01-13 11:23:54 +01:00
Kbuild
Kconfig cs5535: drop the Geode-specific MFGPT/GPIO code 2009-12-15 08:53:28 -08:00
Kconfig.cpu Revert "x86: Side-step lguest problem by only building cmpxchg8b_emu for pre-Pentium" 2010-01-04 19:35:49 -08:00
Kconfig.debug Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-11 20:47:30 -08:00
Makefile
Makefile_32.cpu Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-08 13:38:11 -08:00