mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

ehci: Validate qh is not changed unexpectedly by the guest

Browse Source 
-combine the qh check with the check for devaddr changes
-also ensure that p gets set to NULL when the queue gets cancelled on
 devaddr change, which was not done properly before this patch

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Hans de Goede 2012-08-29 10:37:37 +02:00 committed by Gerd Hoffmann
parent 66f092d256
commit dafe31fc2a
1 changed files with 27 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
hw/usb/hcd-ehci.c
View File

@ -780,6 +780,14 @@ static void ehci_cancel_queue(EHCIQueue *q)
} while ((p = QTAILQ_FIRST(&q->packets)) != NULL);
}
static void ehci_reset_queue(EHCIQueue *q)
{
trace_usb_ehci_queue_action(q, "reset");
ehci_cancel_queue(q);
q->dev = NULL;
q->qtdaddr = 0;
}
static void ehci_free_queue(EHCIQueue *q)
{
EHCIQueueHead *head = q->async ? &q->ehci->aqueues : &q->ehci->pqueues;
@ -1755,8 +1763,9 @@ out:
static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)
{
EHCIPacket *p;
uint32_t entry, devaddr;
uint32_t entry, devaddr, endp;
EHCIQueue *q;
EHCIqh qh;
entry = ehci_get_fetch_addr(ehci, async);
q = ehci_find_queue_by_qh(ehci, entry, async);
@ -1774,17 +1783,25 @@ static EHCIQueue *ehci_state_fetchqh(EHCIState *ehci, int async)
}
get_dwords(ehci, NLPTR_GET(q->qhaddr),
(uint32_t *) &q->qh, sizeof(EHCIqh) >> 2);
ehci_trace_qh(q, NLPTR_GET(q->qhaddr), &q->qh);
(uint32_t *) &qh, sizeof(EHCIqh) >> 2);
ehci_trace_qh(q, NLPTR_GET(q->qhaddr), &qh);
devaddr = get_field(q->qh.epchar, QH_EPCHAR_DEVADDR);
if (q->dev != NULL && q->dev->addr != devaddr) {
if (!QTAILQ_EMPTY(&q->packets)) {
/* should not happen (guest bug) */
ehci_cancel_queue(q);
}
q->dev = NULL;
/*
* The overlay area of the qh should never be changed by the guest,
* except when idle, in which case the reset is a nop.
*/
devaddr = get_field(qh.epchar, QH_EPCHAR_DEVADDR);
endp = get_field(qh.epchar, QH_EPCHAR_EP);
if ((devaddr != get_field(q->qh.epchar, QH_EPCHAR_DEVADDR)) ||
(endp != get_field(q->qh.epchar, QH_EPCHAR_EP)) ||
(memcmp(&qh.current_qtd, &q->qh.current_qtd,
9 * sizeof(uint32_t)) != 0) ||
(q->dev != NULL && q->dev->addr != devaddr)) {
ehci_reset_queue(q);
p = NULL;
}
q->qh = qh;
if (q->dev == NULL) {
q->dev = ehci_find_device(q->ehci, devaddr);
}