From patchwork Tue Mar 16 10:01:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Assmann X-Patchwork-Id: 12141649 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC579C433DB for ; Tue, 16 Mar 2021 10:03:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61EA165018 for ; Tue, 16 Mar 2021 10:03:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236521AbhCPKCg convert rfc822-to-8bit (ORCPT ); Tue, 16 Mar 2021 06:02:36 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:49785 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235852AbhCPKCB (ORCPT ); Tue, 16 Mar 2021 06:02:01 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-190-R1DbDuoePriB3rwkJ-2bww-1; Tue, 16 Mar 2021 06:01:55 -0400 X-MC-Unique: R1DbDuoePriB3rwkJ-2bww-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BFB36107ACCD; Tue, 16 Mar 2021 10:01:53 +0000 (UTC) Received: from p50.redhat.com (ovpn-112-37.ams2.redhat.com [10.36.112.37]) by smtp.corp.redhat.com (Postfix) with ESMTP id 14E736C32E; Tue, 16 Mar 2021 10:01:51 +0000 (UTC) From: Stefan Assmann To: intel-wired-lan@lists.osuosl.org Cc: netdev@vger.kernel.org, anthony.l.nguyen@intel.com, lihong.yang@intel.com, jesse.brandeburg@intel.com, slawomirx.laba@intel.com, nicholas.d.nunley@intel.com, sassmann@kpanic.de Subject: [PATCH] iavf: fix locking of critical sections Date: Tue, 16 Mar 2021 11:01:41 +0100 Message-Id: <20210316100141.53551-1-sassmann@kpanic.de> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=sassmann@kpanic.de X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kpanic.de Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org To avoid races between iavf_init_task(), iavf_reset_task(), iavf_watchdog_task(), iavf_adminq_task() as well as the shutdown and remove functions more locking is required. The current protection by __IAVF_IN_CRITICAL_TASK is needed in additional places. - The reset task performs state transitions, therefore needs locking. - The adminq task acts on replies from the PF in iavf_virtchnl_completion() which may alter the states. - The init task is not only run during probe but also if a VF gets stuck to reinitialize it. - The shutdown function performs a state transition. - The remove function perorms a state transition and also free's resources. iavf_lock_timeout() is introduced to avoid waiting infinitely and cause a deadlock. Rather unlock and print a warning. Signed-off-by: Stefan Assmann Tested-by: Konrad Jankowski --- drivers/net/ethernet/intel/iavf/iavf_main.c | 57 ++++++++++++++++++--- 1 file changed, 50 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c index dc5b3c06d1e0..538b7aa43fa5 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -131,6 +131,30 @@ enum iavf_status iavf_free_virt_mem_d(struct iavf_hw *hw, return 0; } +/** + * iavf_timeout - try to set bit but give up after timeout + * @adapter: board private structure + * @bit: bit to set + * @msecs: timeout in msecs + * + * Returns 0 on success, negative on failure + **/ +static inline int iavf_lock_timeout(struct iavf_adapter *adapter, + enum iavf_critical_section_t bit, + unsigned int msecs) +{ + unsigned int wait, delay = 10; + + for (wait = 0; wait < msecs; wait += delay) { + if (!test_and_set_bit(bit, &adapter->crit_section)) + return 0; + + msleep(delay); + } + + return -1; +} + /** * iavf_schedule_reset - Set the flags and schedule a reset event * @adapter: board private structure @@ -2069,6 +2093,10 @@ static void iavf_reset_task(struct work_struct *work) if (test_bit(__IAVF_IN_REMOVE_TASK, &adapter->crit_section)) return; + if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 200)) { + schedule_work(&adapter->reset_task); + return; + } while (test_and_set_bit(__IAVF_IN_CLIENT_TASK, &adapter->crit_section)) usleep_range(500, 1000); @@ -2275,6 +2303,8 @@ static void iavf_adminq_task(struct work_struct *work) if (!event.msg_buf) goto out; + if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 200)) + goto freedom; do { ret = iavf_clean_arq_element(hw, &event, &pending); v_op = (enum virtchnl_ops)le32_to_cpu(event.desc.cookie_high); @@ -2288,6 +2318,7 @@ static void iavf_adminq_task(struct work_struct *work) if (pending != 0) memset(event.msg_buf, 0, IAVF_MAX_AQ_BUF_SIZE); } while (pending); + clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); if ((adapter->flags & (IAVF_FLAG_RESET_PENDING | IAVF_FLAG_RESET_NEEDED)) || @@ -3590,6 +3621,10 @@ static void iavf_init_task(struct work_struct *work) init_task.work); struct iavf_hw *hw = &adapter->hw; + if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 5000)) { + dev_warn(&adapter->pdev->dev, "failed to set __IAVF_IN_CRITICAL_TASK in %s\n", __FUNCTION__); + return; + } switch (adapter->state) { case __IAVF_STARTUP: if (iavf_startup(adapter) < 0) @@ -3602,14 +3637,14 @@ static void iavf_init_task(struct work_struct *work) case __IAVF_INIT_GET_RESOURCES: if (iavf_init_get_resources(adapter) < 0) goto init_failed; - return; + goto out; default: goto init_failed; } queue_delayed_work(iavf_wq, &adapter->init_task, msecs_to_jiffies(30)); - return; + goto out; init_failed: if (++adapter->aq_wait_count > IAVF_AQ_MAX_ERR) { dev_err(&adapter->pdev->dev, @@ -3618,9 +3653,11 @@ static void iavf_init_task(struct work_struct *work) iavf_shutdown_adminq(hw); adapter->state = __IAVF_STARTUP; queue_delayed_work(iavf_wq, &adapter->init_task, HZ * 5); - return; + goto out; } queue_delayed_work(iavf_wq, &adapter->init_task, HZ); +out: + clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); } /** @@ -3637,9 +3674,12 @@ static void iavf_shutdown(struct pci_dev *pdev) if (netif_running(netdev)) iavf_close(netdev); + if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 5000)) + dev_warn(&adapter->pdev->dev, "failed to set __IAVF_IN_CRITICAL_TASK in %s\n", __FUNCTION__); /* Prevent the watchdog from running. */ adapter->state = __IAVF_REMOVE; adapter->aq_required = 0; + clear_bit(__IAVF_IN_CRITICAL_TASK, &adapter->crit_section); #ifdef CONFIG_PM pci_save_state(pdev); @@ -3866,10 +3906,6 @@ static void iavf_remove(struct pci_dev *pdev) err); } - /* Shut down all the garbage mashers on the detention level */ - adapter->state = __IAVF_REMOVE; - adapter->aq_required = 0; - adapter->flags &= ~IAVF_FLAG_REINIT_ITR_NEEDED; iavf_request_reset(adapter); msleep(50); /* If the FW isn't responding, kick it once, but only once. */ @@ -3877,6 +3913,13 @@ static void iavf_remove(struct pci_dev *pdev) iavf_request_reset(adapter); msleep(50); } + if (iavf_lock_timeout(adapter, __IAVF_IN_CRITICAL_TASK, 5000)) + dev_warn(&adapter->pdev->dev, "failed to set __IAVF_IN_CRITICAL_TASK in %s\n", __FUNCTION__); + + /* Shut down all the garbage mashers on the detention level */ + adapter->state = __IAVF_REMOVE; + adapter->aq_required = 0; + adapter->flags &= ~IAVF_FLAG_REINIT_ITR_NEEDED; iavf_free_all_tx_resources(adapter); iavf_free_all_rx_resources(adapter); iavf_misc_irq_disable(adapter);