2017-12-13 10:44:00

by Jia-Ju Bai

[permalink] [raw]
Subject: [PATCH] macb: Fix a possible sleep-in-atomic bug in macb_tx_error_task

The driver may sleep under a spinlock.
The function call path is:
macb_tx_error_task (acquire the spinlock)
macb_halt_tx
usleep_range --> may sleep

To fix it, usleep_range is replaced with udelay.

This bug is found by my static analysis tool(DSAC) and checked by my code review.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
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 72a67f7..b02c806 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -645,7 +645,7 @@ 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;
--
1.7.9.5