From patchwork Tue Nov 15 01:19:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 13043061 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 F196EC433FE for ; Tue, 15 Nov 2022 01:19:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229967AbiKOBT5 (ORCPT ); Mon, 14 Nov 2022 20:19:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230109AbiKOBTs (ORCPT ); Mon, 14 Nov 2022 20:19:48 -0500 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B9FB13DCC; Mon, 14 Nov 2022 17:19:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668475187; x=1700011187; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=9i9GneyN5wzD0q5QGpre3W00YKsgyhnQ1SvEvL9knhc=; b=FCrCuSzJMbBBE2i2v8aUFEGqLSiGzPlbuBgrxqAENVCMSpaSkUf6WVeR qzLrYdiVmO3gov5Sv1ugRdHj7gHwQnbCu6S9UJNwpE9Ltbiuj7/e8ivsH iBqSQq+RwPG2BdfL+3w9Mtok09XqIBvGhA+SiKNZgIuEFVVtD5JSdntAi XjGsieZTcccDtGOW3VXAYP/KGDFJfZg8CZxt147NLvAzYCGk2qCs0xphL IeGhXfMNaAlpX/I5IgOgDjWYLxRKSZfJrG4OfGxyjUJvr1j16DRHjekBH M0VTaO9CR7U02S5W8/U2ZuaE84NXY+wFH8TLTq4Q+c8//C4XKYorMrJ7w Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10531"; a="374258102" X-IronPort-AV: E=Sophos;i="5.96,164,1665471600"; d="scan'208";a="374258102" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2022 17:19:46 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10531"; a="744378892" X-IronPort-AV: E=Sophos;i="5.96,164,1665471600"; d="scan'208";a="744378892" Received: from iweiny-mobl.amr.corp.intel.com (HELO localhost) ([10.212.91.132]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2022 17:19:45 -0800 From: ira.weiny@intel.com To: Dan Williams , Bjorn Helgaas Cc: Ira Weiny , Bjorn Helgaas , Gregory Price , Jonathan Cameron , Alison Schofield , Vishal Verma , Ben Widawsky , linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH] PCI/doe: Fix work struct declaration Date: Mon, 14 Nov 2022 17:19:43 -0800 Message-Id: <20221115011943.1051039-1-ira.weiny@intel.com> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org From: Ira Weiny The callers of pci_doe_submit_task() allocate the pci_doe_task on the stack. This causes the work structure to be allocated on the stack without pci_doe_submit_task() knowing. Work item initialization needs to be done with either INIT_WORK_ONSTACK() or INIT_WORK() depending on how the work item is allocated. Jonathan suggested creating doe task allocation macros such as DECLARE_CDAT_DOE_TASK_ONSTACK().[1] The issue with this is the work function is not known to the callers and must be initialized correctly. A follow up suggestion was to have an internal 'pci_doe_work' item allocated by pci_doe_submit_task().[2] This requires an allocation which could restrict the context where tasks are used. Compromise with an intermediate step to initialize the task struct with a new call pci_doe_init_task() which must be called prior to submit task. [1] https://lore.kernel.org/linux-cxl/20221014151045.24781-1-Jonathan.Cameron@huawei.com/T/#m88a7f50dcce52f30c8bf5c3dcc06fa9843b54a2d [2] https://lore.kernel.org/linux-cxl/20221014151045.24781-1-Jonathan.Cameron@huawei.com/T/#m63c636c5135f304480370924f4d03c00357be667 Cc: Bjorn Helgaas Reported-by: Gregory Price Reported-by: Jonathan Cameron Suggested-by: Dan Williams Signed-off-by: Ira Weiny Reviewed-by: Jonathan Cameron --- drivers/cxl/core/pci.c | 2 ++ drivers/pci/doe.c | 14 ++++++++++++-- include/linux/pci-doe.h | 8 +++++--- 3 files changed, 19 insertions(+), 5 deletions(-) base-commit: 30a0b95b1335e12efef89dd78518ed3e4a71a763 diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c index 9240df53ed87..a19c1fa0e2f4 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -525,6 +525,7 @@ static int cxl_cdat_get_length(struct device *dev, DECLARE_CDAT_DOE_TASK(CDAT_DOE_REQ(0), t); int rc; + pci_doe_init_task(cdat_doe, &t.task, true); rc = pci_doe_submit_task(cdat_doe, &t.task); if (rc < 0) { dev_err(dev, "DOE submit failed: %d", rc); @@ -554,6 +555,7 @@ static int cxl_cdat_read_table(struct device *dev, u32 *entry; int rc; + pci_doe_init_task(cdat_doe, &t.task, true); rc = pci_doe_submit_task(cdat_doe, &t.task); if (rc < 0) { dev_err(dev, "DOE submit failed: %d", rc); diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c index e402f05068a5..cabeae4ae955 100644 --- a/drivers/pci/doe.c +++ b/drivers/pci/doe.c @@ -319,6 +319,7 @@ static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 *index, u16 *vid, }; int rc; + pci_doe_init_task(doe_mb, &task, true); rc = pci_doe_submit_task(doe_mb, &task); if (rc < 0) return rc; @@ -495,6 +496,14 @@ bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type) } EXPORT_SYMBOL_GPL(pci_doe_supports_prot); +void pci_doe_init_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task, + bool onstack) +{ + task->doe_mb = doe_mb; + __INIT_WORK(&task->work, doe_statemachine_work, onstack); +} +EXPORT_SYMBOL_GPL(pci_doe_init_task); + /** * pci_doe_submit_task() - Submit a task to be processed by the state machine * @@ -517,6 +526,9 @@ int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task) if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type)) return -EINVAL; + if (WARN_ON_ONCE(task->work.func != doe_statemachine_work)) + return -EINVAL; + /* * DOE requests must be a whole number of DW and the response needs to * be big enough for at least 1 DW @@ -528,8 +540,6 @@ int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task) if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags)) return -EIO; - task->doe_mb = doe_mb; - INIT_WORK(&task->work, doe_statemachine_work); queue_work(doe_mb->work_queue, &task->work); return 0; } diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h index ed9b4df792b8..457fc0e53d64 100644 --- a/include/linux/pci-doe.h +++ b/include/linux/pci-doe.h @@ -31,8 +31,8 @@ struct pci_doe_mb; * @rv: Return value. Length of received response or error (bytes) * @complete: Called when task is complete * @private: Private data for the consumer - * @work: Used internally by the mailbox - * @doe_mb: Used internally by the mailbox + * @work: Used internally by the mailbox [see pci_doe_init_task()] + * @doe_mb: Used internally by the mailbox [see pci_doe_init_task()] * * The payload sizes and rv are specified in bytes with the following * restrictions concerning the protocol. @@ -53,7 +53,7 @@ struct pci_doe_task { void (*complete)(struct pci_doe_task *task); void *private; - /* No need for the user to initialize these fields */ + /* Call pci_doe_init_task() for these */ struct work_struct work; struct pci_doe_mb *doe_mb; }; @@ -72,6 +72,8 @@ struct pci_doe_task { struct pci_doe_mb *pcim_doe_create_mb(struct pci_dev *pdev, u16 cap_offset); bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type); +void pci_doe_init_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task, + bool onstack); int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task); #endif