[Xenomai] Pool memory leak when writing to full queue

[Xenomai] Pool memory leak when writing to full queue

[Kai]

Hi,

I have a problem using rt_queue_write() (native skin):
As far as I understand, the function wraps around rt_queue_send() by 
allocating pool memory first and memcpy-ing the user-supplied buffer 
into it.
Problem: If sending fails because the queue is full (w.r.t. the number 
of queued messages), the error is returned to the caller, but the 
allocated pool memory is never freed.
The attached program shows how the pool memory gets almost completely 
filled without any messages left in the queue.

The following patch seems to fix it:

--- xenomai-2.6.1/ksrc/skins/native/syscall_old.c       2012-07-12 
19:53:48.464968791 +0200
+++ xenomai-2.6.1/ksrc/skins/native/syscall.c   2012-07-12 
19:48:34.174968603 +0200
@@ -2358,6 +2358,8 @@
         ret = rt_queue_send(q, mbuf, size, mode);
         if (ret == 0 && (mode & Q_BROADCAST))
                 rt_queue_free(q, mbuf); /* Nobody received, free the 
buffer. */
+       if (ret < 0) /* Send failed */
+               rt_queue_free(q, mbuf);

         return ret;
  }

Regards,
Kai
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Re: [Xenomai] Pool memory leak when writing to full queue

[Philippe Gerum]

On 07/12/2012 09:58 PM, Kai wrote:
> Hi,
>
> I have a problem using rt_queue_write() (native skin):
> As far as I understand, the function wraps around rt_queue_send() by
> allocating pool memory first and memcpy-ing the user-supplied buffer
> into it.
> Problem: If sending fails because the queue is full (w.r.t. the number
> of queued messages), the error is returned to the caller, but the
> allocated pool memory is never freed.
> The attached program shows how the pool memory gets almost completely
> filled without any messages left in the queue.
>
> The following patch seems to fix it:
>
> --- xenomai-2.6.1/ksrc/skins/native/syscall_old.c       2012-07-12
> 19:53:48.464968791 +0200
> +++ xenomai-2.6.1/ksrc/skins/native/syscall.c   2012-07-12
> 19:48:34.174968603 +0200
> @@ -2358,6 +2358,8 @@
>          ret = rt_queue_send(q, mbuf, size, mode);
>          if (ret == 0 && (mode & Q_BROADCAST))
>                  rt_queue_free(q, mbuf); /* Nobody received, free the
> buffer. */
> +       if (ret < 0) /* Send failed */
> +               rt_queue_free(q, mbuf);
>
>          return ret;
>   }

Ack. Picking this one for 2.6.2, thanks.

-- 
Philippe.