On Tue, 28 Mar 2023 14:53:29 -0700
Reinette Chatre <reinette.chatre@xxxxxxxxx> wrote:
> User space provides the vector as an unsigned int that is checked
> early for validity (vfio_set_irqs_validate_and_prepare()).
>
> A later negative check of the provided vector is not necessary.
>
> Remove the negative check and ensure the type used
> for the vector is consistent as an unsigned int.
>
> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
> ---
> drivers/vfio/pci/vfio_pci_intrs.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
> index 6a9c6a143cc3..3f64ccdce69f 100644
> --- a/drivers/vfio/pci/vfio_pci_intrs.c
> +++ b/drivers/vfio/pci/vfio_pci_intrs.c
> @@ -317,14 +317,14 @@ static int vfio_msi_enable(struct vfio_pci_core_device *vdev, int nvec, bool msi
> }
>
> static int vfio_msi_set_vector_signal(struct vfio_pci_core_device *vdev,
> - int vector, int fd, bool msix)
> + unsigned int vector, int fd, bool msix)
> {
> struct pci_dev *pdev = vdev->pdev;
> struct eventfd_ctx *trigger;
> int irq, ret;
> u16 cmd;
>
> - if (vector < 0 || vector >= vdev->num_ctx)
> + if (vector >= vdev->num_ctx)
> return -EINVAL;
>
> irq = pci_irq_vector(pdev, vector);
> @@ -399,7 +399,8 @@ static int vfio_msi_set_vector_signal(struct vfio_pci_core_device *vdev,
> static int vfio_msi_set_block(struct vfio_pci_core_device *vdev, unsigned start,
> unsigned count, int32_t *fds, bool msix)
> {
> - int i, j, ret = 0;
> + int i, ret = 0;
> + unsigned int j;
>
> if (start >= vdev->num_ctx || start + count > vdev->num_ctx)
> return -EINVAL;
Unfortunately this turns the unwind portion of the function into an
infinite loop in the common case when @start is zero:
for (--j; j >= (int)start; j--)
vfio_msi_set_vector_signal(vdev, j, -1, msix);
Thanks,
Alex
> @@ -420,7 +421,7 @@ static int vfio_msi_set_block(struct vfio_pci_core_device *vdev, unsigned start,
> static void vfio_msi_disable(struct vfio_pci_core_device *vdev, bool msix)
> {
> struct pci_dev *pdev = vdev->pdev;
> - int i;
> + unsigned int i;
> u16 cmd;
>
> for (i = 0; i < vdev->num_ctx; i++) {
> @@ -542,7 +543,7 @@ static int vfio_pci_set_msi_trigger(struct vfio_pci_core_device *vdev,
> unsigned index, unsigned start,
> unsigned count, uint32_t flags, void *data)
> {
> - int i;
> + unsigned int i;
> bool msix = (index == VFIO_PCI_MSIX_IRQ_INDEX) ? true : false;
>
> if (irq_is(vdev, index) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
