From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Mon, 21 Jul 2008 23:49:58 +0000 (-0700)
Subject: xen: don't use sysret for sysexit32
X-Git-Tag: v2.6.27-rc1~517^2~2
X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=2dc1697eb355c34f9f7bcbbb83f490de248c360a;p=linux-2.6-omap-h63xx.git

xen: don't use sysret for sysexit32

When implementing sysexit32, don't let Xen use sysret to return to
userspace.  That results in usermode register state being trashed.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S
index 4038cbfe333..7f58304fafb 100644
--- a/arch/x86/xen/xen-asm_64.S
+++ b/arch/x86/xen/xen-asm_64.S
@@ -173,7 +173,7 @@ ENTRY(xen_sysexit)
 	pushq $__USER32_CS
 	pushq %rdx
 
-	pushq $VGCF_in_syscall
+	pushq $0
 1:	jmp hypercall_iret
 ENDPATCH(xen_sysexit)
 RELOC(xen_sysexit, 1b+1)