Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx> writes:
> There is no need to call ep_queue unlocked inside the own driver. We
> move its functionionality into an unlocked version.
>
> This patch removes potential unlocked timeslots inside
> isr_setup_status_phase and isr_get_status_response, in which the lock
> got released just before acquired again inside usb_ep_queue.
>
> Cc: stable <stable@xxxxxxxxxxxxxxx>
Other patches in this set are less questionable, but this is certainly
not stable material. See Documentation/stable_kernel_rules.txt
> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> ---
> drivers/usb/chipidea/udc.c | 118 ++++++++++++++++++++++++++-------------------
> 1 file changed, 68 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> index e7c84ab..61afd71 100644
> --- a/drivers/usb/chipidea/udc.c
> +++ b/drivers/usb/chipidea/udc.c
> @@ -671,6 +671,71 @@ static void isr_get_status_complete(struct usb_ep *ep, struct usb_request *req)
> }
>
> /**
> + * _ep_queue: queues (submits) an I/O request to an endpoint
> + *
> + * Caller must hold lock
> + */
> +static int _ep_queue(struct usb_ep *ep, struct usb_request *req,
> + gfp_t __maybe_unused gfp_flags)
> +{
> + struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep);
> + struct ci13xxx_req *mReq = container_of(req, struct ci13xxx_req, req);
> + struct ci13xxx *ci = mEp->ci;
> + int retval = 0;
> +
> + if (ep == NULL || req == NULL || mEp->ep.desc == NULL)
> + return -EINVAL;
> +
> + if (mEp->type == USB_ENDPOINT_XFER_CONTROL) {
> + if (req->length)
> + mEp = (ci->ep0_dir == RX) ?
> + ci->ep0out : ci->ep0in;
> + if (!list_empty(&mEp->qh.queue)) {
> + _ep_nuke(mEp);
> + retval = -EOVERFLOW;
> + dev_warn(mEp->ci->dev, "endpoint ctrl %X nuked\n",
> + _usb_addr(mEp));
> + }
> + }
> +
> + if (usb_endpoint_xfer_isoc(mEp->ep.desc)) {
> + if (mReq->req.length > mEp->ep.maxpacket)
> + return -EMSGSIZE;
> + }
> +
> + /* first nuke then test link, e.g. previous status has not sent */
> + if (!list_empty(&mReq->queue)) {
> + retval = -EBUSY;
> + dev_err(mEp->ci->dev, "request already in queue\n");
> + goto done;
> + }
> +
> + if (req->length > 4 * CI13XXX_PAGE_SIZE) {
> + retval = -EMSGSIZE;
> + dev_err(mEp->ci->dev, "request bigger than one td\n");
> + goto done;
> + }
> +
> + dbg_queue(_usb_addr(mEp), req, retval);
> +
> + /* push request */
> + mReq->req.status = -EINPROGRESS;
> + mReq->req.actual = 0;
> +
> + retval = _hardware_enqueue(mEp, mReq);
> +
> + if (retval == -EALREADY) {
> + dbg_event(_usb_addr(mEp), "QUEUE", retval);
> + retval = 0;
> + }
> + if (!retval)
> + list_add_tail(&mReq->queue, &mEp->qh.queue);
> +
> + done:
> + return retval;
> +}
> +
> +/**
> * isr_get_status_response: get_status request response
> * @ci: ci struct
> * @setup: setup request packet
> @@ -717,9 +782,7 @@ __acquires(mEp->lock)
> }
> /* else do nothing; reserved for future use */
>
> - spin_unlock(mEp->lock);
> - retval = usb_ep_queue(&mEp->ep, req, gfp_flags);
> - spin_lock(mEp->lock);
> + retval = _ep_queue(&mEp->ep, req, gfp_flags);
> if (retval)
> goto err_free_buf;
>
> @@ -766,8 +829,6 @@ isr_setup_status_complete(struct usb_ep *ep, struct usb_request *req)
> * This function returns an error code
> */
> static int isr_setup_status_phase(struct ci13xxx *ci)
> -__releases(mEp->lock)
> -__acquires(mEp->lock)
> {
> int retval;
> struct ci13xxx_ep *mEp;
> @@ -776,9 +837,7 @@ __acquires(mEp->lock)
> ci->status->context = ci;
> ci->status->complete = isr_setup_status_complete;
>
> - spin_unlock(mEp->lock);
> - retval = usb_ep_queue(&mEp->ep, ci->status, GFP_ATOMIC);
> - spin_lock(mEp->lock);
> + retval = _ep_queue(&mEp->ep, ci->status, GFP_ATOMIC);
>
> return retval;
> }
> @@ -1177,8 +1236,6 @@ static int ep_queue(struct usb_ep *ep, struct usb_request *req,
> gfp_t __maybe_unused gfp_flags)
> {
> struct ci13xxx_ep *mEp = container_of(ep, struct ci13xxx_ep, ep);
> - struct ci13xxx_req *mReq = container_of(req, struct ci13xxx_req, req);
> - struct ci13xxx *ci = mEp->ci;
> int retval = 0;
> unsigned long flags;
>
> @@ -1187,47 +1244,8 @@ static int ep_queue(struct usb_ep *ep, struct usb_request *req,
>
> spin_lock_irqsave(mEp->lock, flags);
>
> - if (mEp->type == USB_ENDPOINT_XFER_CONTROL) {
> - if (req->length)
> - mEp = (ci->ep0_dir == RX) ?
> - ci->ep0out : ci->ep0in;
> - if (!list_empty(&mEp->qh.queue)) {
> - _ep_nuke(mEp);
> - retval = -EOVERFLOW;
> - dev_warn(mEp->ci->dev, "endpoint ctrl %X nuked\n",
> - _usb_addr(mEp));
> - }
> - }
> -
> - /* first nuke then test link, e.g. previous status has not sent */
> - if (!list_empty(&mReq->queue)) {
> - retval = -EBUSY;
> - dev_err(mEp->ci->dev, "request already in queue\n");
> - goto done;
> - }
> -
> - if (req->length > 4 * CI13XXX_PAGE_SIZE) {
> - retval = -EMSGSIZE;
> - dev_err(mEp->ci->dev, "request bigger than one td\n");
> - goto done;
> - }
> -
> - dbg_queue(_usb_addr(mEp), req, retval);
> + retval = _ep_queue(ep, req, gfp_flags);
>
> - /* push request */
> - mReq->req.status = -EINPROGRESS;
> - mReq->req.actual = 0;
> -
> - retval = _hardware_enqueue(mEp, mReq);
> -
> - if (retval == -EALREADY) {
> - dbg_event(_usb_addr(mEp), "QUEUE", retval);
> - retval = 0;
> - }
> - if (!retval)
> - list_add_tail(&mReq->queue, &mEp->qh.queue);
> -
> - done:
> spin_unlock_irqrestore(mEp->lock, flags);
> return retval;
> }
> --
> 1.8.2.rc2
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