[PATCH 4.19 071/105] qlcnic: fix sleep-in-atomic-context bugs caused by msleep

Greg Kroah-Hartman
2022-12-05T19:20:57Z

From: Duoming Zhou <duoming@zju.edu.cn>

[ Upstream commit 8dbd6e4ce1b9c527921643d9e34f188a10d4e893 ]

The watchdog timer is used to monitor whether the process
of transmitting data is timeout. If we use qlcnic driver,
the dev_watchdog() that is the timer handler of watchdog
timer will call qlcnic_tx_timeout() to process the timeout.
But the qlcnic_tx_timeout() calls msleep(), as a result,
the sleep-in-atomic-context bugs will happen. The processes
are shown below:

(atomic context)
dev_watchdog
qlcnic_tx_timeout
qlcnic_83xx_idc_request_reset
qlcnic_83xx_lock_driver
msleep

---------------------------

(atomic context)
dev_watchdog
qlcnic_tx_timeout
qlcnic_83xx_idc_request_reset
qlcnic_83xx_lock_driver
qlcnic_83xx_recover_driver_lock
msleep

Fix by changing msleep() to mdelay(), the mdelay() is
busy-waiting and the bugs could be mitigated.

Fixes: 629263acaea3 ("qlcnic: 83xx CNA inter driver communication mechanism")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c
index d857d44547a5..b3f1f1bd52a8 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c
@@ -2993,7 +2993,7 @@ static void qlcnic_83xx_recover_driver_lock(struct qlcnic_adapter *adapter)
QLCWRX(adapter->ahw, QLC_83XX_RECOVER_DRV_LOCK, val);
dev_info(&adapter->pdev->dev,
"%s: lock recovery initiated\n", __func__);
- msleep(QLC_83XX_DRV_LOCK_RECOVERY_DELAY);
+ mdelay(QLC_83XX_DRV_LOCK_RECOVERY_DELAY);
val = QLCRDX(adapter->ahw, QLC_83XX_RECOVER_DRV_LOCK);
id = ((val >> 2) & 0xF);
if (id == adapter->portnum) {
@@ -3029,7 +3029,7 @@ int qlcnic_83xx_lock_driver(struct qlcnic_adapter *adapter)
if (status)
break;

- msleep(QLC_83XX_DRV_LOCK_WAIT_DELAY);
+ mdelay(QLC_83XX_DRV_LOCK_WAIT_DELAY);
i++;

if (i == 1)
--
2.35.1