LXR linux/drivers/gpu/drm/i915/i915

   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
  38struct 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
  48static 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
  68static 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 */
  81long 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