[ 080/136 ] KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x instructions

Steven Rostedt
2013-05-18T03:06:11Z

[-- Attachment #1: 0080-KVM-X86-emulator-fix-source-operand-decoding-for-8bi.patch --]
[-- Type: text/plain, Size: 1033 bytes --]

3.6.11.4 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Gleb Natapov <gleb@redhat.com>

[ Upstream commit 660696d1d16a71e15549ce1bf74953be1592bcd3 ]

Source operand for one byte mov[zs]x is decoded incorrectly if it is in
high byte register. Fix that.

Cc: stable@vger.kernel.org
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
arch/x86/kvm/emulate.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a3b57a2..2386209 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3970,6 +3970,10 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
break;
case OpMem8:
ctxt->memop.bytes = 1;
+ if (ctxt->memop.type == OP_REG) {
+ ctxt->memop.addr.reg = decode_register(ctxt, ctxt->modrm_rm, 1);
+ fetch_register_operand(&ctxt->memop);
+ }
goto mem_common;
case OpMem16:
ctxt->memop.bytes = 2;
--
1.7.10.4