From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62371C433F5 for ; Mon, 11 Oct 2021 21:02:24 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D8CD860F23 for ; Mon, 11 Oct 2021 21:02:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D8CD860F23 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:58074 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ma2RD-0007bz-06 for qemu-devel@archiver.kernel.org; Mon, 11 Oct 2021 17:02:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38816) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ma2Q9-0006lW-RA for qemu-devel@nongnu.org; Mon, 11 Oct 2021 17:01:17 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:46473) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ma2Q8-0001el-6f for qemu-devel@nongnu.org; Mon, 11 Oct 2021 17:01:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633986074; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=BSLtFg4jULFS1pwaRKMHdtVtdUlqu82SJbCkOUald3Y=; b=OCtG7411Sw3RDE8hFjg7jn8MZ8YsOWVN65HhqSUiiUO6MtL7z+y4lK2JPCaAFwtzFzyAZk v7a/4J1G01kGH8LPQt7NUPUVLKQtJJXGB8SQpm/nrzltBYiNnnjoF/GYBDIPqm+bkKltNy cvZLeDzfXyRNuOlFaCScdFWABOn0gAo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-439-1yaYAXEWP5Ofxx5IeAVoKg-1; Mon, 11 Oct 2021 17:01:09 -0400 X-MC-Unique: 1yaYAXEWP5Ofxx5IeAVoKg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A7629824FB3; Mon, 11 Oct 2021 21:01:07 +0000 (UTC) Received: from redhat.com (ovpn-113-152.phx2.redhat.com [10.3.113.152]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 33CA260BE5; Mon, 11 Oct 2021 21:00:27 +0000 (UTC) Date: Mon, 11 Oct 2021 16:00:25 -0500 From: Eric Blake To: Kevin Wolf Subject: Re: [PATCH v2 09/15] softmmu/qdev-monitor: add error handling in qdev_set_id Message-ID: <20211011210025.kq4qjwn7kzfcwwl5@redhat.com> References: <20211008133442.141332-1-kwolf@redhat.com> <20211008133442.141332-10-kwolf@redhat.com> MIME-Version: 1.0 In-Reply-To: <20211008133442.141332-10-kwolf@redhat.com> User-Agent: NeoMutt/20210205-852-339c0c X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.049, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: damien.hedde@greensocs.com, lvivier@redhat.com, pkrempa@redhat.com, berrange@redhat.com, ehabkost@redhat.com, qemu-block@nongnu.org, mst@redhat.com, libvir-list@redhat.com, jasowang@redhat.com, quintela@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, vsementsov@virtuozzo.com, its@irrelevant.dk, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Oct 08, 2021 at 03:34:36PM +0200, Kevin Wolf wrote: > From: Damien Hedde > > qdev_set_id() is mostly used when the user adds a device (using > -device cli option or device_add qmp command). This commit adds > an error parameter to handle the case where the given id is > already taken. > > Also document the function and add a return value in order to > be able to capture success/failure: the function now returns the > id in case of success, or NULL in case of failure. > > The commit modifies the 2 calling places (qdev-monitor and > xen-legacy-backend) to add the error object parameter. > > Note that the id is, right now, guaranteed to be unique because > all ids came from the "device" QemuOptsList where the id is used > as key. This addition is a preparation for a future commit which > will relax the uniqueness. > > Signed-off-by: Damien Hedde > Signed-off-by: Kevin Wolf > --- > +++ b/softmmu/qdev-monitor.c > @@ -593,22 +593,34 @@ static BusState *qbus_find(const char *path, Error **errp) > } > > /* Takes ownership of @id, will be freed when deleting the device */ > -void qdev_set_id(DeviceState *dev, char *id) > +const char *qdev_set_id(DeviceState *dev, char *id, Error **errp) > { > - if (id) { > - dev->id = id; > - } > + ObjectProperty *prop; > > - if (dev->id) { > - object_property_add_child(qdev_get_peripheral(), dev->id, > - OBJECT(dev)); > + assert(!dev->id && !dev->realized); > + > + /* > + * object_property_[try_]add_child() below will assert the device > + * has no parent > + */ > + if (id) { > + prop = object_property_try_add_child(qdev_get_peripheral(), id, > + OBJECT(dev), NULL); > + if (prop) { > + dev->id = id; > + } else { > + error_setg(errp, "Duplicate device ID '%s'", id); > + return NULL; id is not freed on this error path... > + } > } else { > static int anon_count; > gchar *name = g_strdup_printf("device[%d]", anon_count++); > - object_property_add_child(qdev_get_peripheral_anon(), name, > - OBJECT(dev)); > + prop = object_property_add_child(qdev_get_peripheral_anon(), name, > + OBJECT(dev)); > g_free(name); > } > + > + return prop->name; > } > > DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) > @@ -691,7 +703,13 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp) > } > } > > - qdev_set_id(dev, g_strdup(qemu_opts_id(opts))); > + /* > + * set dev's parent and register its id. > + * If it fails it means the id is already taken. > + */ > + if (!qdev_set_id(dev, g_strdup(qemu_opts_id(opts)), errp)) { > + goto err_del_dev; ...nor on this, which means the g_strdup() leaks on failure. > + } > > /* set properties */ > if (qemu_opt_foreach(opts, set_property, dev, errp)) { > -- > 2.31.1 > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org