From: Ian Abbott <abbotti@mev.co.uk>
Date: Tue, 18 Sep 2012 18:46:57 +0000 (+0100)
Subject: staging: comedi: fix sparse warning in do_devconfig_ioctl()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=dc881f294eb957bded69b5e7f2f72831e2d00ac4;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

staging: comedi: fix sparse warning in do_devconfig_ioctl()

For the COMEDI_DEVCONFIG ioctl, the user application may embed a pointer
to firmware data within a designated element (or two elements for 64-bit
pointers) of the `options[]` array in the `struct comedi_devconfig`.
`do_devconfig_ioctl()` calls `comedi_aux_data()` to extract the pointer
value.  It needs to be treated as a `__user` pointer so the firmware
data can be copied into kernel memory, so cast the result of
`comedi_aux_data()` to avoid a "sparse" warning.  This is not ideal but
`comedi_aux_data()` is called elsewhere in a wholly kernel memory
context so we can't just change its return type to include the `__user`
tag.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 626fa723f199..9b9d4e8a2cf9 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -370,7 +370,8 @@ static int do_devconfig_ioctl(struct comedi_device *dev,
 			return -ENOMEM;
 
 		if (copy_from_user(aux_data,
-				   comedi_aux_data(it.options, 0), aux_len)) {
+				   (unsigned char __user *
+				    )comedi_aux_data(it.options, 0), aux_len)) {
 			vfree(aux_data);
 			return -EFAULT;
 		}