xref: /linux/drivers/gpu/drm/i915/i915_ioc32.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /**
2  * \file i915_ioc32.c
3  *
4  * 32-bit ioctl compatibility routines for the i915 DRM.
5  *
6  * \author Alan Hourihane <alanh@fairlite.demon.co.uk>
7  *
8  *
9  * Copyright (C) Paul Mackerras 2005
10  * Copyright (C) Alan Hourihane 2005
11  * All Rights Reserved.
12  *
13  * Permission is hereby granted, free of charge, to any person obtaining a
14  * copy of this software and associated documentation files (the "Software"),
15  * to deal in the Software without restriction, including without limitation
16  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
17  * and/or sell copies of the Software, and to permit persons to whom the
18  * Software is furnished to do so, subject to the following conditions:
19  *
20  * The above copyright notice and this permission notice (including the next
21  * paragraph) shall be included in all copies or substantial portions of the
22  * Software.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
27  * THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
28  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
29  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
30  * IN THE SOFTWARE.
31  */
32 #include <linux/compat.h>
33 
34 #include <drm/drmP.h>
35 #include <drm/i915_drm.h>
36 #include "i915_drv.h"
37 
38 struct drm_i915_getparam32 {
39 	s32 param;
40 	/*
41 	 * We screwed up the generic ioctl struct here and used a variable-sized
42 	 * pointer. Use u32 in the compat struct to match the 32bit pointer
43 	 * userspace expects.
44 	 */
45 	u32 value;
46 };
47 
48 static int compat_i915_getparam(struct file *file, unsigned int cmd,
49 				unsigned long arg)
50 {
51 	struct drm_i915_getparam32 req32;
52 	drm_i915_getparam_t __user *request;
53 
54 	if (copy_from_user(&req32, (void __user *)arg, sizeof(req32)))
55 		return -EFAULT;
56 
57 	request = compat_alloc_user_space(sizeof(*request));
58 	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
59 	    || __put_user(req32.param, &request->param)
60 	    || __put_user((void __user *)(unsigned long)req32.value,
61 			  &request->value))
62 		return -EFAULT;
63 
64 	return drm_ioctl(file, DRM_IOCTL_I915_GETPARAM,
65 			 (unsigned long)request);
66 }
67 
68 static drm_ioctl_compat_t *i915_compat_ioctls[] = {
69 	[DRM_I915_GETPARAM] = compat_i915_getparam,
70 };
71 
72 /**
73  * Called whenever a 32-bit process running under a 64-bit kernel
74  * performs an ioctl on /dev/dri/card<n>.
75  *
76  * \param filp file pointer.
77  * \param cmd command.
78  * \param arg user argument.
79  * \return zero on success or negative number on failure.
80  */
81 long i915_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
82 {
83 	unsigned int nr = DRM_IOCTL_NR(cmd);
84 	drm_ioctl_compat_t *fn = NULL;
85 	int ret;
86 
87 	if (nr < DRM_COMMAND_BASE || nr >= DRM_COMMAND_END)
88 		return drm_compat_ioctl(filp, cmd, arg);
89 
90 	if (nr < DRM_COMMAND_BASE + ARRAY_SIZE(i915_compat_ioctls))
91 		fn = i915_compat_ioctls[nr - DRM_COMMAND_BASE];
92 
93 	if (fn != NULL)
94 		ret = (*fn) (filp, cmd, arg);
95 	else
96 		ret = drm_ioctl(filp, cmd, arg);
97 
98 	return ret;
99 }
100