Re: [PATCH 2/3] usb: chipidea: udc: improve error handling on ep_queue

[Felipe Ferreri Tonello <eu@felipetonello.com>]

Hi Peter,

Have you seen this patch? I saw that you didn't apply it to your tree,
so I wonder if it is good or do I have to change anything.

This patch is a bug fix for a memory leak, so it is quite important.

-- 
Felipe

On 18/09/15 18:30, eu@felipetonello.com wrote:
> From: "Felipe F. Tonello" <eu@felipetonello.com>
> 
> _ep_queue() didn't check for errors when using add_td_to_list()
> which can fail if dma_pool_alloc fails, thus causing a kernel
> panic when lastnode->ptr is NULL.
> 
> Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
> ---
> 
> Changes for v2:
>   - Use separate patch for cleanups.
> 
>  drivers/usb/chipidea/udc.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> index c936c72..7169113e 100644
> --- a/drivers/usb/chipidea/udc.c
> +++ b/drivers/usb/chipidea/udc.c
> @@ -435,19 +435,27 @@ static int _hardware_enqueue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
>  	if (hwreq->req.dma % PAGE_SIZE)
>  		pages--;
>  
> -	if (rest == 0)
> -		add_td_to_list(hwep, hwreq, 0);
> +	if (rest == 0) {
> +		ret = add_td_to_list(hwep, hwreq, 0);
> +		if (ret < 0)
> +			goto done;
> +	}
>  
>  	while (rest > 0) {
>  		unsigned count = min(hwreq->req.length - hwreq->req.actual,
>  					(unsigned)(pages * CI_HDRC_PAGE_SIZE));
> -		add_td_to_list(hwep, hwreq, count);
> +		ret = add_td_to_list(hwep, hwreq, count);
> +		if (ret < 0)
> +			goto done;
>  		rest -= count;
>  	}
>  
>  	if (hwreq->req.zero && hwreq->req.length
> -	    && (hwreq->req.length % hwep->ep.maxpacket == 0))
> -		add_td_to_list(hwep, hwreq, 0);
> +	    && (hwreq->req.length % hwep->ep.maxpacket == 0)) {
> +		ret = add_td_to_list(hwep, hwreq, 0);
> +		if (ret < 0)
> +			goto done;
> +	}
>  
>  	firstnode = list_first_entry(&hwreq->tds, struct td_node, td);
>  
>