Commit 417406f2 authored by Vincent Whitchurch's avatar Vincent Whitchurch Committed by Greg Kroah-Hartman
Browse files

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: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 96c12ef9

drivers/misc/mic/vop/vop_vringh.c

+20 −12
Original line number Diff line number Diff line
@@ -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;
@@ -606,12 +609,16 @@ 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 (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;
@@ -619,6 +626,7 @@ static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf, 
			vdev->tx_len_unaligned += len;

			dma = false;

		}

	}



	if (!dma)

		goto memcpy;

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