Patchwork usb: dwc3: gadget: Fail request submission if it was already queued

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Submitter Manu Gautam
Date Jan. 11, 2019, 6:02 a.m.
Message ID <20190111060212.7390-1-mgautam@codeaurora.org>
Download mbox | patch
Permalink /patch/697443/
State New
Headers show

Comments

Manu Gautam - Jan. 11, 2019, 6:02 a.m.
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(+)
Felipe Balbi - Jan. 11, 2019, 7:43 a.m.
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.

Anyway, which gadget driver did this? Why is it only affecting dwc3?
Manu Gautam - Jan. 11, 2019, 8:24 a.m.
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).

>

Patch

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) {
+		dev_err(dwc->dev, "%s: %pK request already in queue\n",
+					dep->name, req);
+		return -EBUSY;
+	}
+
 	pm_runtime_get(dwc->dev);
 
 	req->request.actual	= 0;