| Message ID | 1513047037-18102-1-git-send-email-baijiaju1990@163.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
On Tue, 12 Dec 2017, Jia-Ju Bai wrote: > From: Jia-Ju Bai <baijiaju1990@gmail.com> > > The kernel module may sleep under a spinlock. The spinlock is always taken in irq mode, and the schedule_timeout_uninterruptible() is conditional on !irqs_disabled(). > 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 > Well, it's expected to sleep here, hence the "sleep for 1ms" comment. (I notice that you left the comment unchanged in your "fix", was that an oversight?) > 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> NAK. > --- > 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, > Here's a little more context: if (irqs_disabled() || in_interrupt()) return -ETIMEDOUT; > /* 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) > --
Thanks for your reply :) On 2017/12/12 11:38, Finn Thain wrote: > On Tue, 12 Dec 2017, Jia-Ju Bai wrote: > >> From: Jia-Ju Bai <baijiaju1990@gmail.com> >> >> The kernel module may sleep under a spinlock. > The spinlock is always taken in irq mode, and the > schedule_timeout_uninterruptible() is conditional on !irqs_disabled(). > I think I ignore this check, which causes a false bug report, sorry. Thanks, Jia-Ju Bai
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)