virtio_console: fix sparse warnings
CHECK drivers/char/virtio_console.c
drivers/char/virtio_console.c:687:36: warning: incorrect type in
argument 1 (different address spaces)
drivers/char/virtio_console.c:687:36: expected void [noderef]
<asn:1>*to
drivers/char/virtio_console.c:687:36: got char *out_buf
drivers/char/virtio_console.c:790:35: warning: incorrect type in
argument 2 (different address spaces)
drivers/char/virtio_console.c:790:35: expected char *out_buf
drivers/char/virtio_console.c:790:35: got char [noderef]
<asn:1>*ubuf
fill_readbuf is reused with both kernel and userspace pointers,
depending on value of to_user flag.
Tag address parameter as __user, and cast to/from regular pointer type
when we know it's safe.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 6cc832b..de03df9 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -669,8 +669,8 @@
* Give out the data that's requested from the buffer that we have
* queued up.
*/
-static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
- bool to_user)
+static ssize_t fill_readbuf(struct port *port, char __user *out_buf,
+ size_t out_count, bool to_user)
{
struct port_buffer *buf;
unsigned long flags;
@@ -688,7 +688,8 @@
if (ret)
return -EFAULT;
} else {
- memcpy(out_buf, buf->buf + buf->offset, out_count);
+ memcpy((__force char *)out_buf, buf->buf + buf->offset,
+ out_count);
}
buf->offset += out_count;
@@ -1162,7 +1163,7 @@
/* If we don't have an input queue yet, we can't get input. */
BUG_ON(!port->in_vq);
- return fill_readbuf(port, buf, count, false);
+ return fill_readbuf(port, (__force char __user *)buf, count, false);
}
static void resize_console(struct port *port)