On 05.04.23 19:23, Greg KH wrote:
On Fri, Mar 31, 2023 at 05:06:00AM -0400, Pawel Laszczak wrote:
{ struct usb_ctrlrequest *ctrl = &pdev->setup;
- int ret = 0;
- int ret = -EINVAL; u16 len;
trace_cdnsp_ctrl_req(ctrl); @@ -424,7 +424,6 @@ void cdnsp_setup_analyze(struct cdnsp_device *pdev) if (pdev->gadget.state == USB_STATE_NOTATTACHED) { dev_err(pdev->dev, "ERR: Setup detected in unattached state\n");
ret = -EINVAL;That's a nice change, but I don't see the original error here that you are saying this change fixes.
What am I missing?
The function has this check at its beginning:
if (!pdev->gadget_driver) goto out;
ret is initialized to 0 and len is uninitialized. The jump goes to:
out: if (ret < 0) cdnsp_ep0_stall(pdev); else if (!len && pdev->ep0_stage != CDNSP_STATUS_STAGE) cdnsp_status_stage(pdev);
The compiler (and an analysis tool) can determine that len will be evaluated in an uninitialized state. Setting ret to something negative prevents that. I must say this is convoluted, even though it is correct.
HTH Oliver