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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63B13C46467 for ; Wed, 30 Nov 2022 15:37:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229830AbiK3PhO (ORCPT ); Wed, 30 Nov 2022 10:37:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229952AbiK3PhE (ORCPT ); Wed, 30 Nov 2022 10:37:04 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 970D76248; Wed, 30 Nov 2022 07:37:01 -0800 (PST) Received: from frapeml500006.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4NMjsv6pb5z6HJZX; Wed, 30 Nov 2022 23:33:55 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (7.191.163.240) by frapeml500006.china.huawei.com (7.182.85.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 30 Nov 2022 16:36:59 +0100 Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Wed, 30 Nov 2022 15:36:59 +0000 Date: Wed, 30 Nov 2022 15:36:58 +0000 From: Jonathan Cameron To: Lukas Wunner CC: Bjorn Helgaas , , "Gregory Price" , Ira Weiny , "Dan Williams" , Alison Schofield , Vishal Verma , "Li, Ming" , Subject: Re: [PATCH 1/2] PCI/DOE: Silence WARN splat upon task submission Message-ID: <20221130153658.00006674@Huawei.com> In-Reply-To: <9eb6af0763f1ec05673a7dd6731d9fd646cf1dd4.1669608950.git.lukas@wunner.de> References: <9eb6af0763f1ec05673a7dd6731d9fd646cf1dd4.1669608950.git.lukas@wunner.de> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100002.china.huawei.com (7.191.160.241) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Mon, 28 Nov 2022 05:25:51 +0100 Lukas Wunner wrote: > Gregory Price reports a WARN splat with CONFIG_DEBUG_OBJECTS=y upon CXL > probing because pci_doe_submit_task() invokes INIT_WORK() instead of > INIT_WORK_ONSTACK() for a work_struct that was allocated on the stack. > > All callers of pci_doe_submit_task() allocate the work_struct on the > stack, so replace INIT_WORK() with INIT_WORK_ONSTACK() as a backportable > short-term fix. > > Stacktrace for posterity: > > WARNING: CPU: 0 PID: 23 at lib/debugobjects.c:545 __debug_object_init.cold+0x18/0x183 > CPU: 0 PID: 23 Comm: kworker/u2:1 Not tainted 6.1.0-0.rc1.20221019gitaae703b02f92.17.fc38.x86_64 #1 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > Call Trace: > pci_doe_submit_task+0x5d/0xd0 > pci_doe_discovery+0xb4/0x100 > pcim_doe_create_mb+0x219/0x290 > cxl_pci_probe+0x192/0x430 > local_pci_probe+0x41/0x80 > pci_device_probe+0xb3/0x220 > really_probe+0xde/0x380 > __driver_probe_device+0x78/0x170 > driver_probe_device+0x1f/0x90 > __driver_attach_async_helper+0x5c/0xe0 > async_run_entry_fn+0x30/0x130 > process_one_work+0x294/0x5b0 > > Fixes: 9d24322e887b ("PCI/DOE: Add DOE mailbox support functions") > Link: https://lore.kernel.org/linux-cxl/Y1bOniJliOFszvIK@memverge.com/ > Reported-by: Gregory Price > Signed-off-by: Lukas Wunner > Cc: stable@vger.kernel.org # v6.0+ > Cc: Ira Weiny > Cc: Jonathan Cameron > --- > drivers/pci/doe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c > index 66d9ab288646..52541eac17f1 100644 > --- a/drivers/pci/doe.c > +++ b/drivers/pci/doe.c > @@ -541,7 +541,7 @@ int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task) > return -EIO; > > task->doe_mb = doe_mb; > - INIT_WORK(&task->work, doe_statemachine_work); > + INIT_WORK_ONSTACK(&task->work, doe_statemachine_work); If we go this way, add a comment to say 'why' it is ONSTACK or add to the function description to say it 'must be on stack'. > queue_work(doe_mb->work_queue, &task->work); > return 0; > }