diff -r 37ea4cf1281a arch/powerpc/platforms/xen/hcall.c
--- a/arch/powerpc/platforms/xen/hcall.c	Tue Feb 06 17:10:20 2007 -0500
+++ b/arch/powerpc/platforms/xen/hcall.c	Wed Feb 07 08:19:45 2007 -0600
@@ -203,11 +203,14 @@ int HYPERVISOR_sched_op(int cmd, void *a
 
 	desc = xencomm_map_no_alloc(arg, argsize); 
 
-	if (desc == NULL)
-		return -EINVAL;
-
-	rc = plpar_hcall_norets(XEN_MARK(__HYPERVISOR_sched_op),
-				cmd, desc);
+	if (desc) {
+		rc = plpar_hcall_norets(XEN_MARK(__HYPERVISOR_sched_op),
+					cmd, desc);
+		xencomm_free(desc);
+	}
+	else {
+		rc = -EINVAL;
+	}
 
 	xencomm_free(ports);
 
@@ -389,8 +392,8 @@ static int xenppc_privcmd_domctl(privcmd
 	if (copy_to_user(user_op, &kern_op, sizeof(xen_domctl_t)))
 		ret = -EFAULT;
 
-	xencomm_free(desc);
 out:
+	xencomm_free(desc);
 	xencomm_free(op_desc);
 	return ret;
 }
@@ -463,8 +466,8 @@ static int xenppc_privcmd_sysctl(privcmd
 	if (copy_to_user(user_op, &kern_op, sizeof(xen_sysctl_t)))
 		ret = -EFAULT;
 
-	xencomm_free(desc);
 out:
+	xencomm_free(desc);
 	xencomm_free(op_desc);
 	return ret;
 }
@@ -514,8 +517,8 @@ static int xenppc_privcmd_platform_op(pr
 	if (copy_to_user(user_op, &kern_op, sizeof(xen_platform_op_t)))
 		ret = -EFAULT;
 
-	xencomm_free(desc);
 out:
+	xencomm_free(desc);
 	xencomm_free(op_desc);
 	return ret;
 }
@@ -546,8 +549,10 @@ int HYPERVISOR_memory_op(unsigned int cm
 				mop->nr_extents *
 				sizeof(*xen_guest_handle(mop->extent_start)));
 
-			if (desc == NULL)
+			if (desc == NULL) {
+				xencomm_free(op_desc);
 				return -ENOMEM;
+			}
 
 			set_xen_guest_handle(mop->extent_start,
 					     desc);