From: Yuval Basson <ybason@marvell.com>
To: <davem@davemloft.net>, <netdev@vger.kernel.org>
Cc: Yuval Basson <ybason@marvell.com>, Denis Bolotin <dbolotin@marvell.com>
Subject: [PATCH net-next 3/3] qed: Fix race condition between scheduling and destroying the slowpath workqueue
Date: Tue, 24 Mar 2020 16:13:48 +0200 [thread overview]
Message-ID: <20200324141348.7897-4-ybason@marvell.com> (raw)
In-Reply-To: <20200324141348.7897-1-ybason@marvell.com>
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.
Signed-off-by: Yuval Basson <ybason@marvell.com>
Signed-off-by: Denis Bolotin <dbolotin@marvell.com>
---
drivers/net/ethernet/qlogic/qed/qed_main.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/qlogic/qed/qed_main.c b/drivers/net/ethernet/qlogic/qed/qed_main.c
index fb13863..ade927d 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,
@@ -1126,7 +1123,7 @@ 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;
@@ -1139,13 +1136,7 @@ static void qed_slowpath_wq_stop(struct qed_dev *cdev)
clear_bit(QED_SLOWPATH_ACTIVE,
&cdev->hwfns[i].slowpath_task_flags);
- /* 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);
}
}
--
1.8.3.1
prev parent reply other threads:[~2020-03-24 14:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 14:13 [PATCH net-next 0/3] qed: Fix and enhance slowpath workqueue mechanism Yuval Basson
2020-03-24 14:13 ` [PATCH net-next 1/3] qed: Replace wq_active Boolean with an atomic QED_SLOWPATH_ACTIVE flag Yuval Basson
2020-03-24 23:36 ` David Miller
2020-03-25 20:35 ` [EXT] " Yuval Basson
2020-03-24 14:13 ` [PATCH net-next 2/3] qed: Add a flag for rescheduling the slowpath task Yuval Basson
2020-03-24 14:13 ` Yuval Basson [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200324141348.7897-4-ybason@marvell.com \
--to=ybason@marvell.com \
--cc=davem@davemloft.net \
--cc=dbolotin@marvell.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).