Re: [PATCH] usb: dwc3: gadget: Fail request submission if it was already queued

[Manu Gautam <mgautam@codeaurora.org>]

Hi,

On 1/11/2019 1:13 PM, Felipe Balbi wrote:
> Hi,
>
> Manu Gautam <mgautam@codeaurora.org> writes:
>> If a function driver tries to re-submit an already queued request,
>> it can results in corruption of pending/started request lists.
>> Catch such conditions and fail the request submission to DCD.
>>
>> Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
>> ---
>>  drivers/usb/dwc3/gadget.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 679c12e14522..51716c6b286a 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -1290,6 +1290,12 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
>>  				&req->request, req->dep->name))
>>  		return -EINVAL;
>>  
>> +	if (req->request.status == -EINPROGRESS) {
> this test is really not enough. What if gadget driver set status to
> EINPROGRESS before submission? A better check would involve making sure
> req isn't part of dep->pending_list or dep->started_list or
> dep->cancelled_list. It's clear that this won't work very well as the
> amount of requests grow.

Thanks for quick review.
'request.status' check can be replaced:
+if (!list_empty(&req->list) {

And replace list_del with list_del_init from dwc3_gadget_giveback()


>
> Anyway, which gadget driver did this? Why is it only affecting dwc3?

Function driver is not in upstream (f_mtp.c).

>
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