On 24.08.2017 04:02, Jack Pham wrote:
> On Thu, Aug 24, 2017 at 01:47:08AM +0300, Alexey Khoroshilov wrote:
>> There are no checks for dma mapping errors in pch_udc.
>> Tha patch adds the checks and error handling code.
>> Compile tested only.
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
>>
>> Signed-off-by: Alexey Khoroshilov <khoroshi...@ispras.ru>
>> ---
>> drivers/usb/gadget/udc/pch_udc.c | 15 +++++++++++++--
>> 1 file changed, 13 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/udc/pch_udc.c
>> b/drivers/usb/gadget/udc/pch_udc.c
>> index 84dcbcd756f0..a305f8392082 100644
>> --- a/drivers/usb/gadget/udc/pch_udc.c
>> +++ b/drivers/usb/gadget/udc/pch_udc.c
>> @@ -1767,7 +1767,7 @@ static struct usb_request
>> *pch_udc_alloc_request(struct usb_ep *usbep,
>> req->req.dma = DMA_ADDR_INVALID;
>> req->dma = DMA_ADDR_INVALID;
>> INIT_LIST_HEAD(&req->queue);
>> - if (!ep->dev->dma_addr)
>> + if (ep->dev->dma_addr != DMA_ADDR_INVALID)
>> return &req->req;
>> /* ep0 in requests are allocated from data pool here */
>> dma_desc = dma_pool_alloc(ep->dev->data_requests, gfp,
>> @@ -1879,6 +1879,13 @@ static int pch_udc_pcd_queue(struct usb_ep *usbep,
>> struct usb_request *usbreq,
>> usbreq->length,
>> DMA_FROM_DEVICE);
>> }
>> + if (dma_mapping_error(&dev->pdev->dev, req->dma)) {
>> + req->dma = DMA_ADDR_INVALID;
>> + retval = -ENOMEM;
>> + if ((unsigned long)(usbreq->buf) & 0x03)
>> + kfree(req->buf);
>> + goto probe_end;
>> + }
>> req->dma_mapped = 1;
>> }
>> if (usbreq->length > 0) {
>> @@ -2961,6 +2968,10 @@ static int init_dma_pools(struct pch_udc_dev *dev)
>> dev->dma_addr = dma_map_single(&dev->pdev->dev, ep0out_buf,
>> UDC_EP0OUT_BUFF_SIZE * 4,
>> DMA_FROM_DEVICE);
>> + if (dma_mapping_error(&dev->pdev->dev, dev->dma_addr)) {
>> + dev->dma_addr = DMA_ADDR_INVALID;
>> + return -ENOMEM;
>> + }
>
> Wouldn't this driver be better off using the
> usb_gadget_{map,unmap}_request() functions provided by UDC core.c?
> dma_mapping_error() is provided for free that way.
>
I think so, but it requires quite significant rework of the driver.
I would not do that without access to hardware.
--
Alexey
