net: cadence: Fix a sleep-in-atomic-context bug in macb_halt_tx()

[ Upstream commit 16fe10cf92783ed9ceb182d6ea2b8adf5e8ec1b8 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 8d54e7b41bbf203a16dd0d2e7cc43a840c1e4a39..8c698d4647162b9e00b1002660b78666457c8ca8 100644 (file)
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -523,7 +523,7 @@ 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;