2010-01-15 09:30:11

by Tobias Klauser

Subject: [PATCH] staging: iio: Fix locking in __iio_push_event

Correctly unlock the mutex when leaving the function. This was
discovered by the stanse tool at
http://decibel.fi.muni.cz/~xslaby/stanse/error.cgi?db=33-rc&id=138

Cc: Jiri Slaby <[email protected]>
Signed-off-by: Tobias Klauser <[email protected]>
---
drivers/staging/iio/industrialio-core.c | 49 +++++++++++++++++--------------
1 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/drivers/staging/iio/industrialio-core.c b/drivers/staging/iio/industrialio-core.c
index 768f448..fa0f025 100644
--- a/drivers/staging/iio/industrialio-core.c
+++ b/drivers/staging/iio/industrialio-core.c
@@ -78,28 +78,33 @@ EXPORT_SYMBOL(__iio_change_event);

/* Does anyone care? */
mutex_lock(&ev_int->event_list_lock);
- if (test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags)) {
- if (ev_int->current_events == ev_int->max_events)
- return 0;
- ev = kmalloc(sizeof(*ev), GFP_KERNEL);
- if (ev == NULL) {
- ret = -ENOMEM;
- goto error_ret;
- }
- ev->ev.id = ev_code;
- ev->ev.timestamp = timestamp;
- ev->shared_pointer = shared_pointer_p;
- if (ev->shared_pointer)
- shared_pointer_p->ev_p = ev;
-
- list_add_tail(&ev->list, &ev_int->det_events.list);
- ev_int->current_events++;
- mutex_unlock(&ev_int->event_list_lock);
- wake_up_interruptible(&ev_int->wait);
- } else
- mutex_unlock(&ev_int->event_list_lock);
+ if (!test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags))
+ goto out_unlock;

-error_ret:
+ if (ev_int->current_events == ev_int->max_events)
+ goto out_unlock;
+
+ ev = kmalloc(sizeof(*ev), GFP_KERNEL);
+ if (ev == NULL) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ ev->ev.id = ev_code;
+ ev->ev.timestamp = timestamp;
+ ev->shared_pointer = shared_pointer_p;
+ if (ev->shared_pointer)
+ shared_pointer_p->ev_p = ev;
+
+ list_add_tail(&ev->list, &ev_int->det_events.list);
+ ev_int->current_events++;
+ mutex_unlock(&ev_int->event_list_lock);
+ wake_up_interruptible(&ev_int->wait);
+
+ return 0;
+
+out_unlock:
+ mutex_unlock(&ev_int->event_list_lock);
return ret;
}
EXPORT_SYMBOL(__iio_push_event);
--
1.6.3.3

2010-01-17 17:59:36

by Tobias Klauser

Subject: Re: [PATCH] staging: iio: Fix locking in __iio_push_event

On 2010-01-15 at 18:59:41 +0100, Greg KH <[email protected]> wrote:
> On Fri, Jan 15, 2010 at 10:30:01AM +0100, Tobias Klauser wrote:
> > Correctly unlock the mutex when leaving the function. This was
> > discovered by the stanse tool at
> > http://decibel.fi.muni.cz/~xslaby/stanse/error.cgi?db=33-rc&id=138
> >
> > Cc: Jiri Slaby <[email protected]>
> > Signed-off-by: Tobias Klauser <[email protected]>
>
> Sorry, but this is already fixed in my tree, someone beat you to it :)

Oh, I seem to have missed that one in linux-next (or I should have a
closer look at your staging repository the next time :-). Never mind...

Cheers, Tobias

2010-01-15 18:04:55

by Greg KH

Subject: Re: [PATCH] staging: iio: Fix locking in __iio_push_event

On Fri, Jan 15, 2010 at 10:30:01AM +0100, Tobias Klauser wrote:
> Correctly unlock the mutex when leaving the function. This was
> discovered by the stanse tool at
> http://decibel.fi.muni.cz/~xslaby/stanse/error.cgi?db=33-rc&id=138
>
> Cc: Jiri Slaby <[email protected]>
> Signed-off-by: Tobias Klauser <[email protected]>

Sorry, but this is already fixed in my tree, someone beat you to it :)

thanks,

greg k-h