[PATCH AUTOSEL 4.9 20/41] mic: vop: copy data to kernel space then write to io memory

Sasha Levin
2020-10-18T19:32:32Z

From: Sherry Sun <sherry.sun@nxp.com>

[ 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@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Link: https://lore.kernel.org/r/20200929091106.24624-5-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/misc/mic/vop/vop_vringh.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index fed992e2c2583..99bde52a3a256 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -611,6 +611,7 @@ static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf,
size_t partlen;
bool dma = VOP_USE_DMA;
int err = 0;
+ size_t offset = 0;

if (daddr & (dma_alignment - 1)) {
vdev->tx_dst_unaligned += len;
@@ -659,13 +660,20 @@ 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->iounmap(vpdev, dbuf);
--
2.25.1