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xhci: guard xhci_kick_epctx against recursive calls

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Track xhci_kick_epctx processing being active in a variable.  Check the
variable before calling xhci_kick_epctx from xhci_kick_ep.  Add an
assert to make sure we don't call recursively into xhci_kick_epctx.

Cc: 1653384@bugs.launchpad.net
Fixes: 94b037f2a451b3dc855f9f2c346e5049a361bd55
Reported-by: Fabian Lesniak <fabian@lesniak-it.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1486035372-3621-1-git-send-email-kraxel@redhat.com
Message-id: 1485790607-31399-5-git-send-email-kraxel@redhat.com
This commit is contained in:
Gerd Hoffmann 2017-02-02 12:36:12 +01:00
parent ddb603ab6c
commit 96d87bdda3
1 changed files with 7 additions and 0 deletions
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7
hw/usb/hcd-xhci.c
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@ -390,6 +390,7 @@ struct XHCIEPContext {
dma_addr_t pctx;
unsigned int max_psize;
uint32_t state;
uint32_t kick_active;
/* streams */
unsigned int max_pstreams;
@ -2131,6 +2132,9 @@ static void xhci_kick_ep(XHCIState *xhci, unsigned int slotid,
return;
}
if (epctx->kick_active) {
return;
}
xhci_kick_epctx(epctx, streamid);
}
@ -2146,6 +2150,7 @@ static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)
int i;
trace_usb_xhci_ep_kick(epctx->slotid, epctx->epid, streamid);
assert(!epctx->kick_active);
/* If the device has been detached, but the guest has not noticed this
yet the 2 above checks will succeed, but we must NOT continue */
@ -2217,6 +2222,7 @@ static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)
}
assert(ring->dequeue != 0);
epctx->kick_active++;
while (1) {
length = xhci_ring_chain_length(xhci, ring);
if (length <= 0) {
@ -2253,6 +2259,7 @@ static void xhci_kick_epctx(XHCIEPContext *epctx, unsigned int streamid)
break;
}
}
epctx->kick_active--;
ep = xhci_epid_to_usbep(epctx);
if (ep) {