This is a note to let you know that I've just added the patch titled mic: vop: copy data to kernel space then write to io memory to the 5.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mic-vop-copy-data-to-kernel-space-then-write-to-io-m.patch and it can be found in the queue-5.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c7a14c9bc75c994fab39947dcab7969d89d64e60 Author: Sherry Sun <sherry.sun@xxxxxxx> Date: Tue Sep 29 17:11:06 2020 +0800 mic: vop: copy data to kernel space then write to io memory [ Upstream commit 675f0ad4046946e80412896436164d172cd92238 ] Read and write io memory should address align on ARCH ARM. Change to use memcpy_toio to avoid kernel panic caused by the address un-align issue. Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx> Link: https://lore.kernel.org/r/20200929091106.24624-5-sherry.sun@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c index 30eac172f0170..d069947b09345 100644 --- a/drivers/misc/mic/vop/vop_vringh.c +++ b/drivers/misc/mic/vop/vop_vringh.c @@ -602,6 +602,7 @@ static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf, size_t partlen; bool dma = VOP_USE_DMA && vi->dma_ch; int err = 0; + size_t offset = 0; if (dma) { dma_alignment = 1 << vi->dma_ch->device->copy_align; @@ -655,13 +656,20 @@ static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf, * We are copying to IO below and should ideally use something * like copy_from_user_toio(..) if it existed. */ - if (copy_from_user((void __force *)dbuf, ubuf, len)) { - err = -EFAULT; - dev_err(vop_dev(vdev), "%s %d err %d\n", - __func__, __LINE__, err); - goto err; + while (len) { + partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE); + + if (copy_from_user(vvr->buf, ubuf + offset, partlen)) { + err = -EFAULT; + dev_err(vop_dev(vdev), "%s %d err %d\n", + __func__, __LINE__, err); + goto err; + } + memcpy_toio(dbuf + offset, vvr->buf, partlen); + offset += partlen; + vdev->out_bytes += partlen; + len -= partlen; } - vdev->out_bytes += len; err = 0; err: vpdev->hw_ops->unmap(vpdev, dbuf);