From patchwork Sat Mar 15 06:17:17 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 14017744 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 DD738C28B28 for ; Sat, 15 Mar 2025 06:22:21 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ttKrt-0003ke-OB; Sat, 15 Mar 2025 02:19:34 -0400 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 1ttKrO-0003Ha-Vr; Sat, 15 Mar 2025 02:19:09 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ttKrM-0003HO-FQ; Sat, 15 Mar 2025 02:19:02 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 8FEDFFF9D7; Sat, 15 Mar 2025 09:17:07 +0300 (MSK) Received: from gandalf.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with ESMTP id 675511CAC40; Sat, 15 Mar 2025 09:18:01 +0300 (MSK) Received: by gandalf.tls.msk.ru (Postfix, from userid 1000) id 4568D558C5; Sat, 15 Mar 2025 09:18:01 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Thomas Huth , Akihiko Odaki , "Michael S . Tsirkin" , Michael Tokarev Subject: [Stable-9.2.3 11/51] hw/i386/pc: Fix crash that occurs when introspecting TYPE_PC_MACHINE machines Date: Sat, 15 Mar 2025 09:17:17 +0300 Message-Id: <20250315061801.622606-11-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_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 From: Thomas Huth QEMU currently crashes when you try to inspect the machines based on TYPE_PC_MACHINE for their properties: $ echo '{ "execute": "qmp_capabilities" } { "execute": "qom-list-properties","arguments": { "typename": "pc-q35-10.0-machine"}}' \ | ./qemu-system-x86_64 -M pc -qmp stdio {"QMP": {"version": {"qemu": {"micro": 50, "minor": 2, "major": 9}, "package": "v9.2.0-1070-g87e115c122-dirty"}, "capabilities": ["oob"]}} {"return": {}} Segmentation fault (core dumped) This happens because TYPE_PC_MACHINE machines add a machine_init- done_notifier in their instance_init function - but instance_init of machines are not only called for machines that are realized, but also for machines that are introspected, so in this case the listener is added for a q35 machine that is never realized. But since there is already a running pc machine, the listener function is triggered immediately, causing a crash since it was not for the right machine it was meant for. Such listener functions must never be installed from an instance_init function. Let's do it from pc_basic_device_init() instead - this function is called from the MachineClass->init() function instead, i.e. guaranteed to be only called once in the lifetime of a QEMU process. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2779 Signed-off-by: Thomas Huth Message-Id: <20250117192106.471029-1-thuth@redhat.com> Reviewed-by: Akihiko Odaki Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit de538288e4dac21332cc94ba9727ed8ec8fe5ea1) Signed-off-by: Michael Tokarev diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 317aaca25a..9b89b51b8f 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1236,6 +1236,9 @@ void pc_basic_device_init(struct PCMachineState *pcms, /* Super I/O */ pc_superio_init(isa_bus, create_fdctrl, pcms->i8042_enabled, pcms->vmport != ON_OFF_AUTO_ON, &error_fatal); + + pcms->machine_done.notify = pc_machine_done; + qemu_add_machine_init_done_notifier(&pcms->machine_done); } void pc_nic_init(PCMachineClass *pcmc, ISABus *isa_bus, PCIBus *pci_bus) @@ -1709,9 +1712,6 @@ static void pc_machine_initfn(Object *obj) if (pcmc->pci_enabled) { cxl_machine_init(obj, &pcms->cxl_devices_state); } - - pcms->machine_done.notify = pc_machine_done; - qemu_add_machine_init_done_notifier(&pcms->machine_done); } static void pc_machine_reset(MachineState *machine, ResetType type)