KVM: x86 emulator: fix src, dst value initialization

Nitin A Kamble · avikivity · commit 12fa272e315a · 2007-10-13T10:18:29.000+02:00
Some operand fetches are less than the machine word size and can result in
stale bits if used together with operands of different sizes.

Signed-off-by: Nitin A Kamble &lt;nitin.a.kamble@intel.com&gt;
Signed-off-by: Avi Kivity &lt;avi@qumranet.com&gt;
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
@@ -827,6 +827,7 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
 	      srcmem_common:
 		src.type = OP_MEM;
 		src.ptr = (unsigned long *)cr2;
+		src.val = 0;
 		if ((rc = ops->read_emulated((unsigned long)src.ptr,
 					     &src.val, src.bytes, ctxt->vcpu)) != 0)
 			goto done;
@@ -891,6 +892,7 @@ x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
 		dst.type = OP_MEM;
 		dst.ptr = (unsigned long *)cr2;
 		dst.bytes = (d & ByteOp) ? 1 : op_bytes;
+		dst.val = 0;
 		if (d & BitOp) {
 			unsigned long mask = ~(dst.bytes * 8 - 1);
 
