[PATCH]: Fix deadlock in USBIP driver (staging), linux-2.6.34-rc5
in [Kernel]
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From: Eric Lescouet on 22 Apr 2010 13:00 Hi, When detaching a port from the client side (usbip --detach 0), the event thread, on the server side, is going to deadlock. The "eh" server thread is getting USBIP_EH_RESET event and calls: -> stub_device_reset() -> usb_reset_device() the USB framework is then calling back _in the same "eh" thread_ : -> stub_disconnect() -> usbip_stop_eh() -> wait_for_completion() the "eh" thread is being asleep forever, waiting for its own completion. The patch checks if "eh" is the current thread, in usbip_stop_eh(). Please Cc me in reply, I'm not in the list. b.r. ------------------ diff -Nur linux-2.6.34-rc5/drivers/staging/usbip/usbip_event.c linux-2.6.34-rc5.new/drivers/staging/usbip/usbip_event.c --- linux-2.6.34-rc5/drivers/staging/usbip/usbip_event.c 2010-04-20 01:29:56.000000000 +0200 +++ linux-2.6.34-rc5.new/drivers/staging/usbip/usbip_event.c 2010-04-22 17:07:36.249588273 +0200 @@ -116,6 +116,13 @@ void usbip_stop_eh(struct usbip_device *ud) { struct usbip_task *eh = &ud->eh; + int i_am_eh; + + lock_kernel(); + i_am_eh = (eh->thread == current); + unlock_kernel(); + if (i_am_eh) + return; /* do not wait for myself */ wait_for_completion(&eh->thread_done); usbip_dbg_eh("usbip_eh has finished\n"); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |