From f524268211f242fcd382d3d2c811687f5de6f552 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 7 Jul 2017 16:43:35 +0200
Subject: [PATCH] x86emul: shifts/rotates don't allow LOCK prefix

... just like e.g. SHLD/SHRD don't (see commit dee231b5a8 [x86emul:
improve LOCK handling]).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
 xen/arch/x86/x86_emulate/x86_emulate.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index 87e84c6717..6819ab3519 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -3853,6 +3853,7 @@ x86_emulate(
         break;
 
     case 0xc0 ... 0xc1: grp2: /* Grp2 */
+        generate_exception_if(lock_prefix, EXC_UD);
         switch ( modrm_reg & 7 )
         {
         case 0: /* rol */
-- 
2.30.2