linux/arch/x86/xen
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
..
debugfs.c const: constify remaining file_operations 2009-10-01 16:11:11 -07:00
debugfs.h
enlighten.c x86: xen: 64-bit kernel RPL should be 0 2010-01-13 11:23:54 +01:00
grant-table.c
irq.c x86: Move irq_init to x86_init_ops 2009-08-31 09:35:45 +02:00
Kconfig
Makefile xen: make -fstack-protector work under Xen 2009-09-09 16:37:39 -07:00
mmu.c xen: correctly restore pfn_to_mfn_list_list after resume 2009-12-03 11:14:51 -08:00
mmu.h x86: Move paravirt pagetable_setup to x86_init_ops 2009-08-31 09:35:45 +02:00
multicalls.c
multicalls.h
setup.c xen: reserve Xen start_info rather than e820 reserving 2009-05-08 10:51:03 +02:00
smp.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-12-14 09:58:24 -08:00
spinlock.c locking: Convert raw_spinlock to arch_spinlock 2009-12-14 23:55:32 +01:00
suspend.c xen: call clock resume notifier on all CPUs 2009-12-03 11:14:55 -08:00
time.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-12-14 09:58:24 -08:00
vdso.h
xen-asm_32.S
xen-asm_64.S xen: use iret for return from 64b kernel to 32b usermode 2009-12-03 11:14:54 -08:00
xen-asm.h
xen-asm.S
xen-head.S
xen-ops.h xen: correctly restore pfn_to_mfn_list_list after resume 2009-12-03 11:14:51 -08:00