From patchwork Thu May 12 07:59:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 9077471 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 97DB0BF29F for ; Thu, 12 May 2016 08:10:55 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DEF60201F5 for ; Thu, 12 May 2016 08:10:54 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 13443201D3 for ; Thu, 12 May 2016 08:10:54 +0000 (UTC) Received: from localhost ([::1]:55941 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0lhs-00049N-Q9 for patchwork-qemu-devel@patchwork.kernel.org; Thu, 12 May 2016 04:10:52 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54265) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0lWo-00010G-1Y for qemu-devel@nongnu.org; Thu, 12 May 2016 03:59:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b0lWh-0006Nt-Ov for qemu-devel@nongnu.org; Thu, 12 May 2016 03:59:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41452) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b0lWh-0006NR-FC for qemu-devel@nongnu.org; Thu, 12 May 2016 03:59:19 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E2D657F344 for ; Thu, 12 May 2016 07:59:18 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-35.ams2.redhat.com [10.36.116.35]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u4C7xGIf028708 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 12 May 2016 03:59:17 -0400 Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id A30FE11421EF; Thu, 12 May 2016 09:59:10 +0200 (CEST) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Thu, 12 May 2016 09:59:05 +0200 Message-Id: <1463039950-4021-19-git-send-email-armbru@redhat.com> In-Reply-To: <1463039950-4021-1-git-send-email-armbru@redhat.com> References: <1463039950-4021-1-git-send-email-armbru@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Thu, 12 May 2016 07:59:18 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 18/23] qmp: Tighten output visitor rules X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Eric Blake Tighten assertions in the QMP output visitor, so that: - qmp_output_get_qobject() can only be called after pairing a visit_end_* for every visit_start_* (rather than allowing it on a partially built object) - qmp_output_get_qobject() cannot be called unless at least one visit_type_* or visit_start/visit_end pair has occurred since creation/reset (the accidental return of NULL fixed by commit ab8bf1d7 would have been much easier to diagnose) - ensure that we are encountering the expected object or list type, to provide protection against mismatched push(struct)/ pop(list) or push(list)/pop(struct), similar to the qmp-input protection added in commit bdd8e6b5. - ensure that except for the root, 'name' is non-null inside a dict, and NULL inside a list (this may need changing later if we add "name.0" support for better error messages for a list, but for now it makes sure all users are at least consistent) Signed-off-by: Eric Blake Message-Id: <1461879932-9020-19-git-send-email-eblake@redhat.com> Signed-off-by: Markus Armbruster --- qapi/qmp-output-visitor.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c index 5681ad3..4e21f1d 100644 --- a/qapi/qmp-output-visitor.c +++ b/qapi/qmp-output-visitor.c @@ -82,9 +82,8 @@ static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name, QObject *cur = e ? e->value : NULL; if (!cur) { - /* FIXME we should require the user to reset the visitor, rather - * than throwing away the previous root */ - qobject_decref(qov->root); + /* Don't allow reuse of visitor on more than one root */ + assert(!qov->root); qov->root = value; } else { switch (qobject_type(cur)) { @@ -93,6 +92,7 @@ static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name, qdict_put_obj(qobject_to_qdict(cur), name, value); break; case QTYPE_QLIST: + assert(!name); qlist_append_obj(qobject_to_qlist(cur), value); break; default: @@ -114,7 +114,8 @@ static void qmp_output_start_struct(Visitor *v, const char *name, void **obj, static void qmp_output_end_struct(Visitor *v, Error **errp) { QmpOutputVisitor *qov = to_qov(v); - qmp_output_pop(qov); + QObject *value = qmp_output_pop(qov); + assert(qobject_type(value) == QTYPE_QDICT); } static void qmp_output_start_list(Visitor *v, const char *name, Error **errp) @@ -145,7 +146,8 @@ static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp, static void qmp_output_end_list(Visitor *v) { QmpOutputVisitor *qov = to_qov(v); - qmp_output_pop(qov); + QObject *value = qmp_output_pop(qov); + assert(qobject_type(value) == QTYPE_QLIST); } static void qmp_output_type_int64(Visitor *v, const char *name, int64_t *obj, @@ -202,18 +204,16 @@ static void qmp_output_type_null(Visitor *v, const char *name, Error **errp) qmp_output_add_obj(qov, name, qnull()); } -/* Finish building, and return the root object. Will not be NULL. */ +/* Finish building, and return the root object. + * The root object is never null. The caller becomes the object's + * owner, and should use qobject_decref() when done with it. */ QObject *qmp_output_get_qobject(QmpOutputVisitor *qov) { - /* FIXME: we should require that a visit occurred, and that it is - * complete (no starts without a matching end) */ - QObject *obj = qov->root; - if (obj) { - qobject_incref(obj); - } else { - obj = qnull(); - } - return obj; + /* A visit must have occurred, with each start paired with end. */ + assert(qov->root && QTAILQ_EMPTY(&qov->stack)); + + qobject_incref(qov->root); + return qov->root; } Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)