From patchwork Fri Oct 21 22:10:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 9390257 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7D4AE60762 for ; Fri, 21 Oct 2016 22:11:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 532A22A2A1 for ; Fri, 21 Oct 2016 22:11:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 473F32A2A6; Fri, 21 Oct 2016 22:11:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id A92FA2A2A1 for ; Fri, 21 Oct 2016 22:11:09 +0000 (UTC) Received: from localhost ([::1]:34799 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bxi1s-00078b-CC for patchwork-qemu-devel@patchwork.kernel.org; Fri, 21 Oct 2016 18:11:08 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33424) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bxi1a-00077Q-23 for qemu-devel@nongnu.org; Fri, 21 Oct 2016 18:10:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bxi1W-0003cd-FN for qemu-devel@nongnu.org; Fri, 21 Oct 2016 18:10:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54986) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1bxi1W-0003cO-4n for qemu-devel@nongnu.org; Fri, 21 Oct 2016 18:10:46 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (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 3D11C66844; Fri, 21 Oct 2016 22:10:45 +0000 (UTC) Received: from [10.3.116.151] (ovpn-116-151.phx2.redhat.com [10.3.116.151]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u9LMAiQc019251; Fri, 21 Oct 2016 18:10:44 -0400 To: Markus Armbruster , Pino Toscano References: <1476787052-27333-1-git-send-email-ptoscano@redhat.com> <877f91ztpr.fsf@dusky.pond.sub.org> <57db07f2-daee-c494-5ca0-651b53bcc889@redhat.com> From: Eric Blake Openpgp: url=http://people.redhat.com/eblake/eblake.gpg Organization: Red Hat, Inc. Message-ID: <32b6baf4-cd23-c277-4dfb-79922c710efe@redhat.com> Date: Fri, 21 Oct 2016 17:10:43 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <57db07f2-daee-c494-5ca0-651b53bcc889@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Fri, 21 Oct 2016 22:10:45 +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 X-Content-Filtered-By: Mailman/MimeDel 2.1.21 Subject: Re: [Qemu-devel] [PATCH v2] qapi: fix memory leak in QmpOutputVisitor 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: , Cc: qemu-devel@nongnu.org, mdroth@linux.vnet.ibm.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP On 10/21/2016 04:32 PM, Eric Blake wrote: > In fact, applying this patch regresses to the very state that f24582d > tried to prevent. However, I'm unable to see a difference in valgrind > on tests/test-qmp-output-visitor either with or without this patch, > which sadly means our testsuite is not actually testing this scenario. > >>> Should this go into -stable? > > NACK. > > As mentioned in the v1 thread, the leak that Pino was seeing is fixed by > http://lists.nongnu.org/archive/html/qemu-devel/2016-10/msg04023.html > I don't think we don't want this patch. And below is my hack to test-qmp-output-visitor, which shows (at least under valgrind) that we don't want the patch. I should probably turn that into a formal patch submission; but should I piggyback the existing test or add a new one? With the patch omitted, valgrind is happy; with the patch applied, I see: /visitor/output/struct-errors: ==8458== Invalid read of size 8 ==8458== at 0x175DC2: qobject_decref (qobject.h:81) ==8458== by 0x1767A5: qentry_destroy (qdict.c:413) ==8458== by 0x17690B: qdict_destroy_obj (qdict.c:451) ==8458== by 0x1784AB: qobject_destroy (qobject.c:29) ==8458== by 0x171927: qobject_decref (qobject.h:83) ==8458== by 0x1721B4: qmp_output_free (qmp-output-visitor.c:223) ==8458== by 0x16ED8E: visit_free (qapi-visit-core.c:34) ==8458== by 0x130F39: visitor_output_teardown (test-qmp-output-visitor.c:44) ==8458== by 0x130FE1: visitor_reset (test-qmp-output-visitor.c:59) ==8458== by 0x1326EF: test_visitor_out_struct_errors (test-qmp-output-visitor.c:283) ==8458== by 0x50A8940: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== Address 0x8259db8 is 8 bytes inside a block of size 4,120 free'd ==8458== at 0x4C2CD5A: free (vg_replace_malloc.c:530) ==8458== by 0x5088F2D: g_free (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x176937: qdict_destroy_obj (qdict.c:456) ==8458== by 0x1784AB: qobject_destroy (qobject.c:29) ==8458== by 0x171927: qobject_decref (qobject.h:83) ==8458== by 0x1721B4: qmp_output_free (qmp-output-visitor.c:223) ==8458== by 0x16ED8E: visit_free (qapi-visit-core.c:34) ==8458== by 0x130F39: visitor_output_teardown (test-qmp-output-visitor.c:44) ==8458== by 0x130FE1: visitor_reset (test-qmp-output-visitor.c:59) ==8458== by 0x1326EF: test_visitor_out_struct_errors (test-qmp-output-visitor.c:283) ==8458== by 0x50A8940: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== Block was alloc'd at ==8458== at 0x4C2DA60: calloc (vg_replace_malloc.c:711) ==8458== by 0x5088E70: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x175EAF: qdict_new (qdict.c:33) ==8458== by 0x171CAB: qmp_output_start_struct (qmp-output-visitor.c:108) ==8458== by 0x16EE4A: visit_start_struct (qapi-visit-core.c:47) ==8458== by 0x1326E3: test_visitor_out_struct_errors (test-qmp-output-visitor.c:282) ==8458== by 0x50A8940: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8D1D: g_test_run_suite (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8D40: g_test_run (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x134F8D: main (test-qmp-output-visitor.c:899) diff --git i/tests/test-qmp-output-visitor.c w/tests/test-qmp-output-visitor.c index 5e926d3..f1b5591 100644 --- i/tests/test-qmp-output-visitor.c +++ w/tests/test-qmp-output-visitor.c @@ -265,18 +265,22 @@ static void test_visitor_out_struct_errors(TestOutputVisitorData *data, EnumOne bad_values[] = { ENUM_ONE__MAX, -1 }; UserDefOne u = {0}; UserDefOne *pu = &u; - Error *err; + Error *err = NULL; int i; + /* First check: error within struct is detected */ for (i = 0; i < ARRAY_SIZE(bad_values) ; i++) { - err = NULL; u.has_enum1 = true; u.enum1 = bad_values[i]; visit_type_UserDefOne(data->ov, "unused", &pu, &err); - g_assert(err); - error_free(err); + error_free_or_abort(&err); visitor_reset(data); } + + /* Second check: aborting visit early doesn't leak */ + visit_start_struct(data->ov, NULL, NULL, 0, &error_abort); + visit_start_struct(data->ov, "nested", NULL, 0, &error_abort); + visitor_reset(data); }