From: Stefan Assmann sassmann@kpanic.de
[ Upstream commit 226d528512cfac890a1619aea4301f3dd314fe60 ]
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 performs 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 sassmann@kpanic.de Tested-by: Konrad Jankowski konrad0.jankowski@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 da401d5694bf..f06c079e812e 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_lock_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 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 @@ -2064,6 +2088,10 @@ 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); @@ -2278,6 +2306,8 @@ 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); @@ -2291,6 +2321,7 @@ 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)) || @@ -3593,6 +3624,10 @@ 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) @@ -3605,14 +3640,14 @@ 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, @@ -3621,9 +3656,11 @@ 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); }
/** @@ -3640,9 +3677,12 @@ 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); @@ -3870,10 +3910,6 @@ 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. */ @@ -3881,6 +3917,13 @@ 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);