Messages in this thread | | | Date | Mon, 20 Nov 2023 10:38:48 -0700 | From | Alex Williamson <> | Subject | Re: [PATCH] vfio/pci: Separate INTx-enabled vfio_pci_device from unenabled to make the code logic clearer. |
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On Mon, 20 Nov 2023 11:17:52 +0800 JianChunfu <chunfu.jian@shingroup.cn> wrote:
> It seems a little unclear when dealing with vfio_intx_set_signal() > because of vfio_pci_device which is irq_none, > so separate the two situations. > > Signed-off-by: JianChunfu <chunfu.jian@shingroup.cn> > --- > drivers/vfio/pci/vfio_pci_intrs.c | 31 +++++++++++++++---------------- > 1 file changed, 15 insertions(+), 16 deletions(-) > > diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c > index 6069a11fb51a..b6d126c48393 100644 > --- a/drivers/vfio/pci/vfio_pci_intrs.c > +++ b/drivers/vfio/pci/vfio_pci_intrs.c > @@ -468,6 +468,8 @@ static int vfio_pci_set_intx_trigger(struct vfio_pci_core_device *vdev, > unsigned index, unsigned start, > unsigned count, uint32_t flags, void *data) > { > + int32_t fd = *(int32_t *)data;
This is a null pointer dereference if anyone were to use VFIO_IRQ_SET_DATA_NONE. Note this is also invalid for VFIO_IRQ_SET_DATA_BOOL. I think this is largely why the function has the current layout.
> + > if (is_intx(vdev) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) { > vfio_intx_disable(vdev); > return 0; > @@ -476,28 +478,25 @@ static int vfio_pci_set_intx_trigger(struct vfio_pci_core_device *vdev, > if (!(is_intx(vdev) || is_irq_none(vdev)) || start != 0 || count != 1) > return -EINVAL; > > - if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { > - int32_t fd = *(int32_t *)data; > + if (!is_intx(vdev)) { > int ret; > + if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
@ret should be scoped within this branch with this layout and there should be a blank line after variable declaration.
> + ret = vfio_intx_enable(vdev); > + if (ret) > + return ret; > > - if (is_intx(vdev)) > - return vfio_intx_set_signal(vdev, fd); > + ret = vfio_intx_set_signal(vdev, fd); > + if (ret) > + vfio_intx_disable(vdev); > > - ret = vfio_intx_enable(vdev); > - if (ret) > return ret; > - > - ret = vfio_intx_set_signal(vdev, fd); > - if (ret) > - vfio_intx_disable(vdev); > - > - return ret; > + } else > + return -EINVAL;
Single line branches also get braces if the previous branch required braces. Thanks,
Alex
> } > > - if (!is_intx(vdev)) > - return -EINVAL; > - > - if (flags & VFIO_IRQ_SET_DATA_NONE) { > + if (flags & VFIO_IRQ_SET_DATA_EVENTFD) { > + return vfio_intx_set_signal(vdev, fd); > + } else if (flags & VFIO_IRQ_SET_DATA_NONE) { > vfio_send_intx_eventfd(vdev, NULL); > } else if (flags & VFIO_IRQ_SET_DATA_BOOL) { > uint8_t trigger = *(uint8_t *)data;
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