usb: uhci: Look up queue by address, not token

Submitted by Jan Kiszka on Nov. 15, 2012, 8:20 a.m.

Details

Message ID 50A4A5D7.8030508@siemens.com
State New
Headers show

Commit Message

Jan Kiszka Nov. 15, 2012, 8:20 a.m.
The queue token is insufficient to identify if a TD belongs to it. What
we need is the QH address.

This fixes the case where the guest issues multiple asynchronous
requests for the same EP.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

I'm not 100% this still fulfills the aim of "Verify queue has not been
changed by guest". On the other hand, the current code looks quite
wrong to me after studying the spec for a while.

 hw/usb/hcd-uhci.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

Comments

Gerd Hoffmann Nov. 15, 2012, 8:30 a.m.
On 11/15/12 09:20, Jan Kiszka wrote:
> -        if (queue->token == token) {
> +        if (queue->qh_addr == qh_addr) {

Patch added to usb patch queue.

thanks,
  Gerd

Patch hide | download patch | download mbox

diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index f4b555a..1434a3a 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -227,13 +227,12 @@  static void uhci_queue_free(UHCIQueue *queue, const char *reason)
     g_free(queue);
 }
 
-static UHCIQueue *uhci_queue_find(UHCIState *s, UHCI_TD *td)
+static UHCIQueue *uhci_queue_find(UHCIState *s, uint32_t qh_addr)
 {
-    uint32_t token = uhci_queue_token(td);
     UHCIQueue *queue;
 
     QTAILQ_FOREACH(queue, &s->queues, next) {
-        if (queue->token == token) {
+        if (queue->qh_addr == qh_addr) {
             return queue;
         }
     }
@@ -841,7 +840,7 @@  static int uhci_handle_td(UHCIState *s, UHCIQueue *q, uint32_t qh_addr,
     }
 
     if (q == NULL) {
-        q = uhci_queue_find(s, td);
+        q = uhci_queue_find(s, qh_addr);
         if (q && !uhci_queue_verify(q, qh_addr, td, td_addr, queuing)) {
             uhci_queue_free(q, "guest re-used qh");
             q = NULL;