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authorJia-Ju Bai <baijiaju1990@gmail.com>2018-09-01 20:11:05 +0800
committerDavid S. Miller <davem@davemloft.net>2018-09-02 16:05:25 -0700
commit16fe10cf92783ed9ceb182d6ea2b8adf5e8ec1b8 (patch)
treedc652a85653af60c212ca20262c6d01e092a946d
parenta80afe89d81af6b64bf2d9b3afef70dcf75df12b (diff)
downloadlinux-16fe10cf92783ed9ceb182d6ea2b8adf5e8ec1b8.tar.gz
net: cadence: Fix a sleep-in-atomic-context bug in macb_halt_tx()
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/cadence/macb_main.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index c6707ea2d751..16e4ef7d7185 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -649,7 +649,7 @@ 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;