From patchwork Fri Nov 15 17:25:16 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: 13876653 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 81A5ED68BCD for ; Fri, 15 Nov 2024 17:26:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tC04q-0004CY-0J; Fri, 15 Nov 2024 12:25:49 -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 1tC04i-00042s-7z for qemu-devel@nongnu.org; Fri, 15 Nov 2024 12:25:40 -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 1tC04g-0001WY-En for qemu-devel@nongnu.org; Fri, 15 Nov 2024 12:25:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1731691537; 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=I4tw7doBeG+8gbO5Vlw4cl4cj4yji98/v8xm8WxYBAA=; b=UHv4mO8kIjbRSucse5D6Lty0mI/EYiVK5naj1L6j+x+MTruVwZRSzQKNOGEVVzwnQ8LPoT LCJD4NpNhN5ULsvEmi5cbmJcGZ6Eo7FDqKgkDtRSo16zUaDgWUyh95AjH7EETs52aBCx3R TFbAZD39fDcOkXaAxky3IYa32vuNWKo= Received: from mx-prod-mc-01.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-80-enFzytpGN7SA71PYQDos8Q-1; Fri, 15 Nov 2024 12:25:36 -0500 X-MC-Unique: enFzytpGN7SA71PYQDos8Q-1 X-Mimecast-MFC-AGG-ID: enFzytpGN7SA71PYQDos8Q Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4F5DC195FE24 for ; Fri, 15 Nov 2024 17:25:35 +0000 (UTC) Received: from toolbox.redhat.com (unknown [10.42.28.102]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 3D3263003B71; Fri, 15 Nov 2024 17:25:32 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Peter Xu , Markus Armbruster , =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= Subject: [PATCH v3 4/9] qom: introduce object_new_dynamic() Date: Fri, 15 Nov 2024 17:25:16 +0000 Message-ID: <20241115172521.504102-5-berrange@redhat.com> In-Reply-To: <20241115172521.504102-1-berrange@redhat.com> References: <20241115172521.504102-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 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=-0.12, 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 object_new() has a failure scenario where it will assert() if given an abstract type. Callers which are creating objects based on user input, or unknown/untrusted type names, must manually check the result of object_class_is_abstract() before calling object_new() to propagate an Error, instead of asserting. Introduce a object_new_dynamic() method which is a counterpart to object_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. Reviewed-by: Peter Xu Signed-off-by: Daniel P. Berrangé --- include/qom/object.h | 27 +++++++++++++++++++++++++++ qom/object.c | 9 +++++++++ 2 files changed, 36 insertions(+) diff --git a/include/qom/object.h b/include/qom/object.h index 11ee472719..4fc01336c4 100644 --- a/include/qom/object.h +++ b/include/qom/object.h @@ -624,14 +624,41 @@ Object *object_new_with_class(ObjectClass *klass, Error **errp); * object_new: * @typename: The name of the type of the object to instantiate. * + * This method should be used where @typename is statically specified + * from a const string at build time, where the caller does not expect + * failure to be possible. + * * This function will initialize a new object using heap allocated memory. * The returned object has a reference count of 1, and will be freed when * the last reference is dropped. * + * If an instance of @typename is not permitted to be instantiated, an + * assert will be raised. This can happen if @typename is abstract. + * * Returns: The newly allocated and instantiated object. */ Object *object_new(const char *typename); +/** + * object_new_dynamic: + * @typename: The name of the type of the object to instantiate. + * @errp: pointer to be filled with error details on failure + * + * This method should be used where @typename is dynamically chosen + * at runtime, which has the possibility of unexpected choices leading + * to failures. + * + * This function will initialize a new object using heap allocated memory. + * The returned object has a reference count of 1, and will be freed when + * the last reference is dropped. + * + * If an instance of @typename is not permitted to be instantiated, an + * error will be raised. This can happen if @typename is abstract. + * + * Returns: The newly allocated and instantiated object. + */ +Object *object_new_dynamic(const char *typename, Error **errp); + /** * object_new_with_props: * @typename: The name of the type of the object to instantiate. diff --git a/qom/object.c b/qom/object.c index ad5b3b9582..42ef40a1fd 100644 --- a/qom/object.c +++ b/qom/object.c @@ -806,6 +806,15 @@ Object *object_new(const char *typename) return object_new_with_type(ti, &error_abort); } +Object *object_new_dynamic(const char *typename, Error **errp) +{ + TypeImpl *ti = type_get_or_load_by_name(typename, errp); + if (!ti) { + return NULL; + } + + return object_new_with_type(ti, errp); +} Object *object_new_with_props(const char *typename, Object *parent,