From: Gleb Natapov <gleb@redhat.com>
Date: Wed, 24 Apr 2013 10:38:36 +0000 (+0300)
Subject: KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x instructions
X-Git-Tag: v3.8.12~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b63018273bb6c505777a7ddccb8120f08111a6c0;p=thirdparty%2Fkernel%2Fstable.git

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

commit 660696d1d16a71e15549ce1bf74953be1592bcd3 upstream.

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

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index a27e763711087..d330b3c619f8f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4030,6 +4030,10 @@ 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;