From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753425AbaLALgN (ORCPT ); Mon, 1 Dec 2014 06:36:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47920 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753004AbaLALgM (ORCPT ); Mon, 1 Dec 2014 06:36:12 -0500 Date: Mon, 1 Dec 2014 13:35:57 +0200 From: "Michael S. Tsirkin" To: linux-kernel@vger.kernel.org Cc: Amit Shah , Arnd Bergmann , Greg Kroah-Hartman , virtualization@lists.linux-foundation.org Subject: [PATCH] virtio_console: fix sparse warnings Message-ID: <1417433749-17408-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mutt-Fcc: =sent Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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] *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] *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 --- drivers/char/virtio_console.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 775c898..ccb5357 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -669,8 +669,8 @@ done: * 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 @@ static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count, 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 @@ static int get_chars(u32 vtermno, char *buf, int count) /* 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) -- MST