From patchwork Mon Nov 11 15:55:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 13870939 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id E5C97D3ABC1 for ; Mon, 11 Nov 2024 15:56:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tAWmF-00047b-K6; Mon, 11 Nov 2024 10:56:31 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tAWm7-00046M-7x for qemu-devel@nongnu.org; Mon, 11 Nov 2024 10:56:27 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tAWm4-0000o8-Ff for qemu-devel@nongnu.org; Mon, 11 Nov 2024 10:56:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1731340579; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3RLA2LvhoRZELB6SKfMNWBJg+Gq4+HNddrgQKNW6k3I=; b=Uaum3iUeXohtrHWthmZ2WuxxJgg4FMfi6OcUFH8f4WjzhdI1zxvhGboOXq5AdSZggCkyUX /j+2jNx9ngXWJhnQ2FR+EAPU/knwueMFrLCjAMM08L5AWMJRil39Xv/9uIIRooB3Y9u/Qs FpwVj0vqbae997gp+1bbCyX3pgCDFg4= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-6-9kK-89eFPv2AMClKBHygFg-1; Mon, 11 Nov 2024 10:56:17 -0500 X-MC-Unique: 9kK-89eFPv2AMClKBHygFg-1 X-Mimecast-MFC-AGG-ID: 9kK-89eFPv2AMClKBHygFg Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 875F81955EE9 for ; Mon, 11 Nov 2024 15:56:16 +0000 (UTC) Received: from toolbox.redhat.com (unknown [10.42.28.238]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0C9FC19560A3; Mon, 11 Nov 2024 15:56:13 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Markus Armbruster , Peter Xu , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= Subject: [PATCH v2 6/8] qom: introduce qdev_new_dynamic() Date: Mon, 11 Nov 2024 15:55:53 +0000 Message-ID: <20241111155555.90091-7-berrange@redhat.com> In-Reply-To: <20241111155555.90091-1-berrange@redhat.com> References: <20241111155555.90091-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.122, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org qdev_new() has a failure scenario where it will assert() if given an abstract type. Callers which are creating qdevs based on user input, or unknown/untrusted type names, must manually check the result of qdev_class_is_abstract() before calling qdev_new() to propagate an Error, instead of asserting. Introduce a qdev_new_dynamic() method which is a counterpart to qdev_new() that directly returns an Error, instead of asserting. This new method is to be used where the typename is specified dynamically by code separate from the immediate caller. Do likewise with qdev_try_new_dynamic() as a counterpart to qdev_try_new(). Signed-off-by: Daniel P. Berrangé --- hw/core/qdev.c | 14 +++++++++++ include/hw/qdev-core.h | 54 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+) diff --git a/hw/core/qdev.c b/hw/core/qdev.c index b32db8618e..10a7b87c3d 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -149,6 +149,11 @@ DeviceState *qdev_new(const char *name) return DEVICE(object_new_dynamic(name, &error_abort)); } +DeviceState *qdev_new_dynamic(const char *name, Error **errp) +{ + return DEVICE(object_new_dynamic(name, errp)); +} + DeviceState *qdev_try_new(const char *name) { ObjectClass *oc = module_object_class_by_name(name); @@ -158,6 +163,15 @@ DeviceState *qdev_try_new(const char *name) return DEVICE(object_new_with_class(oc, &error_abort)); } +DeviceState *qdev_try_new_dynamic(const char *name, Error **errp) +{ + ObjectClass *oc = module_object_class_by_name(name); + if (!oc) { + return NULL; + } + return DEVICE(object_new_with_class(oc, errp)); +} + static QTAILQ_HEAD(, DeviceListener) device_listeners = QTAILQ_HEAD_INITIALIZER(device_listeners); diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index 5be9844412..68ebaec058 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -435,26 +435,80 @@ compat_props_add(GPtrArray *arr, * qdev_new: Create a device on the heap * @name: device type to create (we assert() that this type exists) * + * This method should be used where @name is statically specified + * from a const string at build time, where the caller does not expect + * failure to be possible. + * * This only allocates the memory and initializes the device state * structure, ready for the caller to set properties if they wish. * The device still needs to be realized. * + * If an instance of @name is not permitted to be instantiated, an + * assert will be raised. This can happen if @name is abstract. + * * Return: a derived DeviceState object with a reference count of 1. */ DeviceState *qdev_new(const char *name); +/** + * qdev_new_dynamic: Create a device on the heap + * @name: device type to create (we assert() that this type exists) + * @errp: pointer to be filled with error details on failure + * + * This method must be used where @name is dynamically chosen + * at runtime, which has the possibility of unexpected choices leading + * to failures. + * + * This only allocates the memory and initializes the device state + * structure, ready for the caller to set properties if they wish. + * The device still needs to be realized. + * + * If an instance of @name is not permitted to be instantiated, an + * error will be reported. This can happen if @name is abstract. + * + * Return: a derived DeviceState object with a reference count of 1. + */ +DeviceState *qdev_new_dynamic(const char *name, Error **errp); + /** * qdev_try_new: Try to create a device on the heap * @name: device type to create * + * This method should be used where @name is statically specified + * from a const string at build time, where the caller does not expect + * failure to be possible. + * * This is like qdev_new(), except it returns %NULL when type @name * does not exist, rather than asserting. * + * If an instance of @name is not permitted to be instantiated, an + * assert will be raised. This can happen if @name is abstract. + * * Return: a derived DeviceState object with a reference count of 1 or * NULL if type @name does not exist. */ DeviceState *qdev_try_new(const char *name); +/** + * qdev_try_new_dynamic: Try to create a device on the heap + * @name: device type to create + * @errp: pointer to be filled with error details on failure + * + * This method must be used where @name is dynamically chosen + * at runtime, which has the possibility of unexpected choices leading + * to failures. + * + * This is like qdev_new_dynamic(), except it returns %NULL when type @name + * does not exist, rather than asserting. + * + * If an instance of @name is not permitted to be instantiated, an + * error will be reported. This can happen if @name is abstract. + * + * Return: a derived DeviceState object with a reference count of 1 or + * NULL if type @name does not exist. + */ +DeviceState *qdev_try_new_dynamic(const char *name, Error **errp); + /** * qdev_is_realized() - check if device is realized * @dev: The device to check.