diff options
| author | Vincent Whitchurch <vincent.whitchurch@axis.com> | 2019-01-16 19:32:50 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-22 13:43:17 +0300 |
| commit | 417406f2bd5415685663eb1c618744bce3b3584e (patch) | |
| tree | 5004021b98e3a5e2a9ab7b9d5a325c731999d37c | |
| parent | 96c12ef9b905237978855d582eff6b4dee152f52 (diff) | |
| download | linux-417406f2bd5415685663eb1c618744bce3b3584e.tar.xz | |
vop: vringh: Do not crash if no DMA channel
Fallback gracefully if no DMA channel is provided instead of
dereferencing NULL pointers.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/misc/mic/vop/vop_vringh.c | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c index 4267fa08b483..0bac8bce933c 100644 --- a/drivers/misc/mic/vop/vop_vringh.c +++ b/drivers/misc/mic/vop/vop_vringh.c @@ -531,12 +531,12 @@ static int vop_virtio_copy_to_user(struct vop_vdev *vdev, void __user *ubuf, void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len); struct vop_vringh *vvr = &vdev->vvr[vr_idx]; struct vop_info *vi = dev_get_drvdata(&vpdev->dev); - size_t dma_alignment = 1 << vi->dma_ch->device->copy_align; - bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1); + size_t dma_alignment; + bool x200; size_t dma_offset, partlen; int err; - if (!VOP_USE_DMA) { + if (!VOP_USE_DMA || !vi->dma_ch) { if (copy_to_user(ubuf, (void __force *)dbuf, len)) { err = -EFAULT; dev_err(vop_dev(vdev), "%s %d err %d\n", @@ -548,6 +548,9 @@ static int vop_virtio_copy_to_user(struct vop_vdev *vdev, void __user *ubuf, goto err; } + dma_alignment = 1 << vi->dma_ch->device->copy_align; + x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1); + dma_offset = daddr - round_down(daddr, dma_alignment); daddr -= dma_offset; len += dma_offset; @@ -606,18 +609,23 @@ static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf, void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len); struct vop_vringh *vvr = &vdev->vvr[vr_idx]; struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev); - size_t dma_alignment = 1 << vi->dma_ch->device->copy_align; - bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1); + size_t dma_alignment; + bool x200; size_t partlen; - bool dma = VOP_USE_DMA; + bool dma = VOP_USE_DMA && vi->dma_ch; int err = 0; - if (daddr & (dma_alignment - 1)) { - vdev->tx_dst_unaligned += len; - dma = false; - } else if (ALIGN(len, dma_alignment) > dlen) { - vdev->tx_len_unaligned += len; - dma = false; + if (dma) { + dma_alignment = 1 << vi->dma_ch->device->copy_align; + x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1); + + if (daddr & (dma_alignment - 1)) { + vdev->tx_dst_unaligned += len; + dma = false; + } else if (ALIGN(len, dma_alignment) > dlen) { + vdev->tx_len_unaligned += len; + dma = false; + } } if (!dma) |