I think I see a possible error in xhci-ring.c. When doing a build (of
current -next or 2.6.39-rc1) I get the warning:
drivers/usb/host/xhci-ring.c:1229:18: warning: â??hcdâ?? may be used
uninitialized in this function
Looking at handle_port_status(), it appears that it is indeed possible
for this function to call usb_hcd_poll_rh_status(hcd), by way of goto
cleanup in error cases, before hcd has been initialized. I believe the
fix is to initialize hcd to NULL and then only call
usb_hcd_poll_rh_status() if hcd is not NULL.
If, indeed, that's the correct way to deal with it, here's a patch.
------------------
From: Bill Pemberton <wfp5p@xxxxxxxxxxxx>
xhci: do not call usb_hcd_poll_rh_status with uinititialized hcd
Fixes the follow compilation warning:
drivers/usb/host/xhci-ring.c:1229:18: warning: â??hcdâ?? may be used uninitialized in this function
It was possible for hcd to be used uninitialized if the error
conditions before hcd is initialized jump to cleanup:, which would pass
the uninitialized hcd structure to usb_hcd_poll_rh_status.
Signed-off-by: Bill Pemberton <wfp5p@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-ring.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index cfc1ad9..fa7ec6f 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1226,7 +1226,7 @@ static unsigned int find_faked_portnum_from_hw_portnum(struct usb_hcd *hcd,
static void handle_port_status(struct xhci_hcd *xhci,
union xhci_trb *event)
{
- struct usb_hcd *hcd;
+ struct usb_hcd *hcd = NULL;
u32 port_id;
u32 temp, temp1;
int max_ports;
@@ -1335,10 +1335,12 @@ cleanup:
/* Update event ring dequeue pointer before dropping the lock */
inc_deq(xhci, xhci->event_ring, true);
- spin_unlock(&xhci->lock);
- /* Pass this up to the core */
- usb_hcd_poll_rh_status(hcd);
- spin_lock(&xhci->lock);
+ if (hcd != NULL) {
+ spin_unlock(&xhci->lock);
+ /* Pass this up to the core */
+ usb_hcd_poll_rh_status(hcd);
+ spin_lock(&xhci->lock);
+ }
}
/*
--
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