From patchwork Mon Jan 23 10:11:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 13111937 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 E6B28C38142 for ; Mon, 23 Jan 2023 10:28:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231468AbjAWK17 (ORCPT ); Mon, 23 Jan 2023 05:27:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229548AbjAWK17 (ORCPT ); Mon, 23 Jan 2023 05:27:59 -0500 X-Greylist: delayed 381 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 23 Jan 2023 02:27:57 PST Received: from mailout3.hostsharing.net (mailout3.hostsharing.net [IPv6:2a01:4f8:150:2161:1:b009:f236:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91B6B126E8; Mon, 23 Jan 2023 02:27:56 -0800 (PST) Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL Global TLS RSA4096 SHA256 2022 CA1" (verified OK)) by mailout3.hostsharing.net (Postfix) with ESMTPS id 64FF8101E6B03; Mon, 23 Jan 2023 11:21:31 +0100 (CET) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 27548600D2E1; Mon, 23 Jan 2023 11:21:31 +0100 (CET) X-Mailbox-Line: From cc4b61809e2520d835cf3d4f62e7d5ed00a9d031 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Mon, 23 Jan 2023 11:11:00 +0100 Subject: [PATCH v2 01/10] PCI/DOE: Silence WARN splat with CONFIG_DEBUG_OBJECTS=y To: Bjorn Helgaas , linux-pci@vger.kernel.org Cc: Gregory Price , Ira Weiny , Jonathan Cameron , Dan Williams , Alison Schofield , Vishal Verma , Dave Jiang , "Li, Ming" , Hillf Danton , Ben Widawsky , linuxarm@huawei.com, linux-cxl@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org 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 Tested-by: Ira Weiny Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v6.0+ Cc: Jonathan Cameron Reviewed-by: Ira Weiny Reviewed-by: Jonathan Cameron Tested-by: Gregory Price Reviewed-by: Gregory Price Reviewed-by: Dan Williams --- Changes v1 -> v2: * Add note in kernel-doc of pci_doe_submit_task() that pci_doe_task must be allocated on the stack (Jonathan) drivers/pci/doe.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c index 66d9ab288646..12a6752351bf 100644 --- a/drivers/pci/doe.c +++ b/drivers/pci/doe.c @@ -520,6 +520,8 @@ EXPORT_SYMBOL_GPL(pci_doe_supports_prot); * task->complete will be called when the state machine is done processing this * task. * + * @task must be allocated on the stack. + * * Excess data will be discarded. * * RETURNS: 0 when task has been successfully queued, -ERRNO on error @@ -541,7 +543,7 @@ 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); queue_work(doe_mb->work_queue, &task->work); return 0; }