From fed5ea87e02aaf902ff38c65b4514233db03dc09 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Tue, 1 Dec 2009 16:15:30 +0000 Subject: [PATCH] xen: don't leak IRQs over suspend/resume. On resume irq_info[*].evtchn is reset to 0 since event channel mappings are not preserved over suspend/resume. The other contents of irq_info is preserved to allow rebind_evtchn_irq() to function. However when a device resumes it will try to unbind from the previous IRQ (e.g. blkfront goes blkfront_resume() -> blkif_free() -> unbind_from_irqhandler() -> unbind_from_irq()). This will fail due to the check for VALID_EVTCHN in unbind_from_irq() and the IRQ is leaked. The device will then continue to resume and allocate a new IRQ, eventually leading to find_unbound_irq() panic()ing. Fix this by changing unbind_from_irq() to handle teardown of interrupts which have type!=IRQT_UNBOUND but are not currently bound to a specific event channel. Signed-off-by: Ian Campbell Signed-off-by: Jeremy Fitzhardinge Cc: Stable Kernel --- drivers/xen/events.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 2f57276e87a2..ce602dd09bc1 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -474,6 +474,9 @@ static void unbind_from_irq(unsigned int irq) bind_evtchn_to_cpu(evtchn, 0); evtchn_to_irq[evtchn] = -1; + } + + if (irq_info[irq].type != IRQT_UNBOUND) { irq_info[irq] = mk_unbound_info(); dynamic_irq_cleanup(irq); -- 2.20.1