[ 34/76] vfio: Move PCI INTx eventfd setting earlier

Greg Kroah-Hartman
2012-10-19T03:01:35Z

From: Alex Williamson <alex.williamson@redhat.com>

commit 9dbdfd23b7638d054f3b0e70c64dfb9f297f2a9f upstream.

We need to be ready to recieve an interrupt as soon as we call
request_irq, so our eventfd context setting needs to be moved
earlier. Without this, an interrupt from our device or one
sharing the interrupt line can pass a NULL into eventfd_signal
and oops.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/vfio/pci/vfio_pci_intrs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -400,19 +400,20 @@ static int vfio_intx_set_signal(struct v
return PTR_ERR(trigger);
}

+ vdev->ctx[0].trigger = trigger;
+
if (!vdev->pci_2_3)
irqflags = 0;

ret = request_irq(pdev->irq, vfio_intx_handler,
irqflags, vdev->ctx[0].name, vdev);
if (ret) {
+ vdev->ctx[0].trigger = NULL;
kfree(vdev->ctx[0].name);
eventfd_ctx_put(trigger);
return ret;
}

- vdev->ctx[0].trigger = trigger;
-
/*
* INTx disable will stick across the new irq setup,
* disable_irq won't.