From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: nicolas.ferre@microchip.com, davem@davemloft.net
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] net: cadence: Fix a sleep-in-atomic-context bug in macb_halt_tx()
Date: Sat, 1 Sep 2018 20:11:05 +0800 [thread overview]
Message-ID: <20180901121105.436-1-baijiaju1990@gmail.com> (raw)
The kernel module may sleep with holding a spinlock.
The function call paths (from bottom to top) in Linux-4.16 are:
[FUNC] usleep_range
drivers/net/ethernet/cadence/macb_main.c, 648:
usleep_range in macb_halt_tx
drivers/net/ethernet/cadence/macb_main.c, 730:
macb_halt_tx in macb_tx_error_task
drivers/net/ethernet/cadence/macb_main.c, 721:
_raw_spin_lock_irqsave in macb_tx_error_task
To fix this bug, usleep_range() is replaced with udelay().
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
drivers/net/ethernet/cadence/macb_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index a6c911bb5ce2..3dcc31cd4261 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -641,7 +641,7 @@ static int macb_halt_tx(struct macb *bp)
if (!(status & MACB_BIT(TGO)))
return 0;
- usleep_range(10, 250);
+ udelay(250);
} while (time_before(halt_time, timeout));
return -ETIMEDOUT;
--
2.17.0
next reply other threads:[~2018-09-01 12:11 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-01 12:11 Jia-Ju Bai [this message]
2018-09-02 23:05 ` [PATCH] net: cadence: Fix a sleep-in-atomic-context bug in macb_halt_tx() David Miller
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