From: Yuval Basson Date: Wed, 25 Mar 2020 20:50:43 +0000 (+0200) Subject: qed: Fix race condition between scheduling and destroying the slowpath workqueue X-Git-Tag: v5.7-rc1~146^2~46 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3b85720d3fd72e6ef4de252cd2f67548eb645eb4;p=thirdparty%2Flinux.git qed: Fix race condition between scheduling and destroying the slowpath workqueue 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 Signed-off-by: Michal Kalderon Signed-off-by: Yuval Basson Signed-off-by: David S. Miller --- 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); } }