Re: [PATCH] virtio_console: fix sparse warnings

From: Greg Kroah-Hartman
Date: Tue Feb 03 2015 - 18:48:33 EST


On Mon, Dec 01, 2014 at 01:35:57PM +0200, Michael S. Tsirkin wrote:
> 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.

That's horrid, don't do that. Have two different functions for this
type of thing, otherwise you defeat the whole purpose of trying to track
__user pointers.

thanks,

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/