i915_ioc32.c revision 1.2 
1/*	$NetBSD: i915_ioc32.c,v 1.2 2018/08/27 04:58:23 riastradh Exp $	*/
2
3/**
4 * \file i915_ioc32.c
5 *
6 * 32-bit ioctl compatibility routines for the i915 DRM.
7 *
8 * \author Alan Hourihane <alanh@fairlite.demon.co.uk>
9 *
10 *
11 * Copyright (C) Paul Mackerras 2005
12 * Copyright (C) Alan Hourihane 2005
13 * All Rights Reserved.
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
21 *
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
24 * Software.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
29 * THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
30 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
31 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 * IN THE SOFTWARE.
33 */
34#include <sys/cdefs.h>
35__KERNEL_RCSID(0, "$NetBSD: i915_ioc32.c,v 1.2 2018/08/27 04:58:23 riastradh Exp $");
36
37#include <linux/compat.h>
38
39#include <drm/drmP.h>
40#include <drm/i915_drm.h>
41#include "i915_drv.h"
42
43struct drm_i915_getparam32 {
44	s32 param;
45	/*
46	 * We screwed up the generic ioctl struct here and used a variable-sized
47	 * pointer. Use u32 in the compat struct to match the 32bit pointer
48	 * userspace expects.
49	 */
50	u32 value;
51};
52
53static int compat_i915_getparam(struct file *file, unsigned int cmd,
54				unsigned long arg)
55{
56	struct drm_i915_getparam32 req32;
57	drm_i915_getparam_t __user *request;
58
59	if (copy_from_user(&req32, (void __user *)arg, sizeof(req32)))
60		return -EFAULT;
61
62	request = compat_alloc_user_space(sizeof(*request));
63	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
64	    || __put_user(req32.param, &request->param)
65	    || __put_user((void __user *)(unsigned long)req32.value,
66			  &request->value))
67		return -EFAULT;
68
69	return drm_ioctl(file, DRM_IOCTL_I915_GETPARAM,
70			 (unsigned long)request);
71}
72
73static drm_ioctl_compat_t *i915_compat_ioctls[] = {
74	[DRM_I915_GETPARAM] = compat_i915_getparam,
75};
76
77/**
78 * Called whenever a 32-bit process running under a 64-bit kernel
79 * performs an ioctl on /dev/dri/card<n>.
80 *
81 * \param filp file pointer.
82 * \param cmd command.
83 * \param arg user argument.
84 * \return zero on success or negative number on failure.
85 */
86long i915_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
87{
88	unsigned int nr = DRM_IOCTL_NR(cmd);
89	drm_ioctl_compat_t *fn = NULL;
90	int ret;
91
92	if (nr < DRM_COMMAND_BASE || nr >= DRM_COMMAND_END)
93		return drm_compat_ioctl(filp, cmd, arg);
94
95	if (nr < DRM_COMMAND_BASE + ARRAY_SIZE(i915_compat_ioctls))
96		fn = i915_compat_ioctls[nr - DRM_COMMAND_BASE];
97
98	if (fn != NULL)
99		ret = (*fn) (filp, cmd, arg);
100	else
101		ret = drm_ioctl(filp, cmd, arg);
102
103	return ret;
104}
105