This is a note to let you know that I've just added the patch titled
qed: Fix race condition between scheduling and destroying the slowpath workqueue
to the 5.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
qed-fix-race-condition-between-scheduling-and-destro.patch
and it can be found in the queue-5.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3e28406b06464970c5b5994433983ac1f1c26ac9
Author: Yuval Basson <ybason@xxxxxxxxxxx>
Date: Wed Mar 25 22:50:43 2020 +0200
qed: Fix race condition between scheduling and destroying the slowpath workqueue
commit 3b85720d3fd72e6ef4de252cd2f67548eb645eb4 upstream.
Calling queue_delayed_work concurrently with
destroy_workqueue might race to an unexpected outcome -
scheduled task after wq is destroyed or other resources
(like ptt_pool) are freed (yields NULL pointer dereference).
cancel_delayed_work prevents the race by cancelling
the timer triggered for scheduling a new task.
Fixes: 59ccf86fe ("qed: Add driver infrastucture for handling mfw requests")
Signed-off-by: Denis Bolotin <dbolotin@xxxxxxxxxxx>
Signed-off-by: Michal Kalderon <mkalderon@xxxxxxxxxxx>
Signed-off-by: Yuval Basson <ybason@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/net/ethernet/qlogic/qed/qed_main.c b/drivers/net/ethernet/qlogic/qed/qed_main.c
index 2c189c637ccaa..96356e897c80e 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_main.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_main.c
@@ -1087,9 +1087,6 @@ static void qed_update_pf_params(struct qed_dev *cdev,
#define QED_PERIODIC_DB_REC_INTERVAL_MS 100
#define QED_PERIODIC_DB_REC_INTERVAL \
msecs_to_jiffies(QED_PERIODIC_DB_REC_INTERVAL_MS)
-#define QED_PERIODIC_DB_REC_WAIT_COUNT 10
-#define QED_PERIODIC_DB_REC_WAIT_INTERVAL \
- (QED_PERIODIC_DB_REC_INTERVAL_MS / QED_PERIODIC_DB_REC_WAIT_COUNT)
static int qed_slowpath_delayed_work(struct qed_hwfn *hwfn,
enum qed_slowpath_wq_flag wq_flag,
@@ -1123,7 +1120,7 @@ void qed_periodic_db_rec_start(struct qed_hwfn *p_hwfn)
static void qed_slowpath_wq_stop(struct qed_dev *cdev)
{
- int i, sleep_count = QED_PERIODIC_DB_REC_WAIT_COUNT;
+ int i;
if (IS_VF(cdev))
return;
@@ -1135,13 +1132,7 @@ static void qed_slowpath_wq_stop(struct qed_dev *cdev)
/* Stop queuing new delayed works */
cdev->hwfns[i].slowpath_wq_active = false;
- /* Wait until the last periodic doorbell recovery is executed */
- while (test_bit(QED_SLOWPATH_PERIODIC_DB_REC,
- &cdev->hwfns[i].slowpath_task_flags) &&
- sleep_count--)
- msleep(QED_PERIODIC_DB_REC_WAIT_INTERVAL);
-
- flush_workqueue(cdev->hwfns[i].slowpath_wq);
+ cancel_delayed_work(&cdev->hwfns[i].slowpath_task);
destroy_workqueue(cdev->hwfns[i].slowpath_wq);
}
}
