From 2e2f1ef719a2fa55fd1d95d9536fa8cca94459a4 Mon Sep 17 00:00:00 2001 From: P33M Date: Thu, 18 Jul 2013 17:07:26 +0100 Subject: [PATCH 082/196] dwc_otg: prevent OOPSes during device disconnects The dwc_otg_urb_enqueue function is thread-unsafe. In particular the access of urb->hcpriv, usb_hcd_link_urb_to_ep, dwc_otg_urb->qtd and friends does not occur within a critical section and so if a device was unplugged during activity there was a high chance that the usbcore hub_thread would try to disable the endpoint with partially- formed entries in the URB queue. This would result in BUG() or null pointer dereferences. Fix so that access of urb->hcpriv, enqueuing to the hardware and adding to usbcore endpoint URB lists is contained within a single critical section. --- drivers/usb/host/dwc_otg/dwc_otg_hcd.c | 3 --- drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c | 14 +++++--------- drivers/usb/host/dwc_otg/dwc_otg_hcd_queue.c | 6 +----- 3 files changed, 6 insertions(+), 17 deletions(-) diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c index af9108c..a1970dc 100644 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c @@ -464,7 +464,6 @@ int dwc_otg_hcd_urb_enqueue(dwc_otg_hcd_t * hcd, dwc_otg_hcd_urb_t * dwc_otg_urb, void **ep_handle, int atomic_alloc) { - dwc_irqflags_t flags; int retval = 0; uint8_t needs_scheduling = 0; dwc_otg_transaction_type_e tr_type; @@ -515,12 +514,10 @@ int dwc_otg_hcd_urb_enqueue(dwc_otg_hcd_t * hcd, } if(needs_scheduling) { - DWC_SPINLOCK_IRQSAVE(hcd->lock, &flags); tr_type = dwc_otg_hcd_select_transactions(hcd); if (tr_type != DWC_OTG_TRANSACTION_NONE) { dwc_otg_hcd_queue_transactions(hcd, tr_type); } - DWC_SPINUNLOCK_IRQRESTORE(hcd->lock, flags); } return retval; } diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c index 0f72bd5..ad03ff1 100644 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c @@ -679,9 +679,7 @@ static int dwc_otg_urb_enqueue(struct usb_hcd *hcd, #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,28) struct usb_host_endpoint *ep = urb->ep; #endif -#if USB_URB_EP_LINKING dwc_irqflags_t irqflags; -#endif void **ref_ep_hcpriv = &ep->hcpriv; dwc_otg_hcd_t *dwc_otg_hcd = hcd_to_dwc_otg_hcd(hcd); dwc_otg_hcd_urb_t *dwc_otg_urb; @@ -733,7 +731,6 @@ static int dwc_otg_urb_enqueue(struct usb_hcd *hcd, if(dwc_otg_urb == NULL) return -ENOMEM; - urb->hcpriv = dwc_otg_urb; if (!dwc_otg_urb && urb->number_of_packets) return -ENOMEM; @@ -775,10 +772,10 @@ static int dwc_otg_urb_enqueue(struct usb_hcd *hcd, iso_frame_desc[i].length); } -#if USB_URB_EP_LINKING DWC_SPINLOCK_IRQSAVE(dwc_otg_hcd->lock, &irqflags); + urb->hcpriv = dwc_otg_urb; +#if USB_URB_EP_LINKING retval = usb_hcd_link_urb_to_ep(hcd, urb); - DWC_SPINUNLOCK_IRQRESTORE(dwc_otg_hcd->lock, irqflags); if (0 == retval) #endif { @@ -794,17 +791,16 @@ static int dwc_otg_urb_enqueue(struct usb_hcd *hcd, urb); } } else { -#if USB_URB_EP_LINKING - dwc_irqflags_t irqflags; DWC_DEBUGPL(DBG_HCD, "DWC OTG dwc_otg_hcd_urb_enqueue failed rc %d\n", retval); - DWC_SPINLOCK_IRQSAVE(dwc_otg_hcd->lock, &irqflags); +#if USB_URB_EP_LINKING usb_hcd_unlink_urb_from_ep(hcd, urb); - DWC_SPINUNLOCK_IRQRESTORE(dwc_otg_hcd->lock, irqflags); #endif + urb->hcpriv = NULL; if (retval == -DWC_E_NO_DEVICE) retval = -ENODEV; } } + DWC_SPINUNLOCK_IRQRESTORE(dwc_otg_hcd->lock, irqflags); return retval; } diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd_queue.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd_queue.c index 8125307..5aed416 100644 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd_queue.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd_queue.c @@ -919,6 +919,7 @@ void dwc_otg_hcd_qtd_init(dwc_otg_qtd_t * qtd, dwc_otg_hcd_urb_t * urb) * QH to place the QTD into. If it does not find a QH, then it will create a * new QH. If the QH to which the QTD is added is not currently scheduled, it * is placed into the proper schedule based on its EP type. + * HCD lock must be held and interrupts must be disabled on entry * * @param[in] qtd The QTD to add * @param[in] hcd The DWC HCD structure @@ -931,8 +932,6 @@ int dwc_otg_hcd_qtd_add(dwc_otg_qtd_t * qtd, dwc_otg_hcd_t * hcd, dwc_otg_qh_t ** qh, int atomic_alloc) { int retval = 0; - dwc_irqflags_t flags; - dwc_otg_hcd_urb_t *urb = qtd->urb; /* @@ -946,15 +945,12 @@ int dwc_otg_hcd_qtd_add(dwc_otg_qtd_t * qtd, goto done; } } - DWC_SPINLOCK_IRQSAVE(hcd->lock, &flags); retval = dwc_otg_hcd_qh_add(hcd, *qh); if (retval == 0) { DWC_CIRCLEQ_INSERT_TAIL(&((*qh)->qtd_list), qtd, qtd_list_entry); qtd->qh = *qh; } - DWC_SPINUNLOCK_IRQRESTORE(hcd->lock, flags); - done: return retval; -- 1.9.1