From: Gleb Natapov <gleb@redhat.com>
Date: Thu, 18 Mar 2010 13:20:14 +0000 (+0200)
Subject: KVM: x86 emulator: If LOCK prefix is used dest arg should be memory.
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a41ffb7540cb37426759e688083502d6463421b2;p=linux-beck.git

KVM: x86 emulator: If LOCK prefix is used dest arg should be memory.

If LOCK prefix is used dest arg should be memory, otherwise instruction
should generate #UD.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b89a8f217332..46a7ee3040a0 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1842,7 +1842,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
 	}
 
 	/* LOCK prefix is allowed only with some instructions */
-	if (c->lock_prefix && !(c->d & Lock)) {
+	if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) {
 		kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
 		goto done;
 	}