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iavf: fix locking of critical sections 

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>
This commit is contained in:
Stefan Assmann 2021-03-16 11:01:41 +01:00 committed by Tony Nguyen
parent 22c8fd71d3
commit 226d528512
1 changed files with 50 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
drivers/net/ethernet/intel/iavf/iavf_main.c
View File

@ -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
@ -2101,6 +2125,10 @@ 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);
@ -2307,6 +2335,8 @@ 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);
@ -2320,6 +2350,7 @@ 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)) ||
@ -3624,6 +3655,10 @@ 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)
@ -3636,14 +3671,14 @@ 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,
@ -3652,9 +3687,11 @@ init_failed:
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);
}
/**
@ -3671,9 +3708,12 @@ 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);
@ -3907,10 +3947,6 @@ 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. */
@ -3918,6 +3954,13 @@ 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);