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Subject[PATCH] NCR5380: Fix a possible sleep-in-atomic bug in NCR5380_poll_politely2
Date
From: Jia-Ju Bai <baijiaju1990@gmail.com>

The kernel module may sleep under a spinlock.
The function call paths are:
NCR5380_select (acquire the spinlock)
NCR5380_reselect
NCR5380_poll_politely
NCR5380_poll_politely2
schedule_timeout_uninterruptible --> may sleep

NCR5380_abort (acquire the spinlock)
do_abort
NCR5380_poll_politely
NCR5380_poll_politely2
schedule_timeout_uninterruptible --> may sleep

To fix it, schedule_timeout_uninterruptible is replaced with mdelay.

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


Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
drivers/scsi/NCR5380.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 90ea0f5..4176aca 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -202,7 +202,7 @@ static int NCR5380_poll_politely2(struct NCR5380_hostdata *hostdata,

/* Repeatedly sleep for 1 ms until deadline */
while (time_is_after_jiffies(deadline)) {
- schedule_timeout_uninterruptible(1);
+ mdelay(1);
if ((NCR5380_read(reg1) & bit1) == val1)
return 0;
if ((NCR5380_read(reg2) & bit2) == val2)
--
1.7.9.5

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