sound/core/ioctl32/ioctl32.h

   1 /*
   2  *   32bit -> 64bit ioctl helpers
   3  *   Copyright (c) by Takashi Iwai <tiwai@suse.de>
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *   GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program; if not, write to the Free Software
  17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  *
  19  *
  20  * This file registers the converters from 32-bit ioctls to 64-bit ones.
  21  * The converter assumes that a 32-bit user-pointer can be casted by A(x)
  22  * macro to a valid 64-bit pointer which is accessible via copy_from/to_user.
  23  *
  24  */
  25
  26 #ifndef __ALSA_IOCTL32_H
  27 #define __ALSA_IOCTL32_H
  28
  29 #include <linux/compat.h>
  30
  31 #define COPY(x)  (dst->x = src->x)
  32 #define CPTR(x)  (dst->x = compat_ptr(src->x))
  33
  34 #define convert_from_32(type, dstp, srcp)\
  35 {\
  36         struct sndrv_##type *dst = dstp;\
  37         struct sndrv_##type##32 *src = srcp;\
  38         CVT_##sndrv_##type();\
  39 }
  40
  41 #define convert_to_32(type, dstp, srcp)\
  42 {\
  43         struct sndrv_##type *src = srcp;\
  44         struct sndrv_##type##32 *dst = dstp;\
  45         CVT_##sndrv_##type();\
  46 }
  47
  48
  49 #define DEFINE_ALSA_IOCTL(type) \
  50 static int _snd_ioctl32_##type(unsigned int fd, unsigned int cmd, unsigned long arg, struct file *file, unsigned int native_ctl)\
  51 {\
  52         struct sndrv_##type##32 data32;\
  53         struct sndrv_##type data;\
  54         mm_segment_t oldseg;\
  55         int err;\
  56         if (copy_from_user(&data32, (void __user *)arg, sizeof(data32)))\
  57                 return -EFAULT;\
  58         memset(&data, 0, sizeof(data));\
  59         convert_from_32(type, &data, &data32);\
  60         oldseg = get_fs();\
  61         set_fs(KERNEL_DS);\
  62         err = file->f_op->ioctl(file->f_dentry->d_inode, file, native_ctl, (unsigned long)&data);\
  63         set_fs(oldseg);\
  64         if (err < 0) \
  65                 return err;\
  66         if (native_ctl & (_IOC_READ << _IOC_DIRSHIFT)) {\
  67                 convert_to_32(type, &data32, &data);\
  68                 if (copy_to_user((void __user *)arg, &data32, sizeof(data32)))\
  69                         return -EFAULT;\
  70         }\
  71         return 0;\
  72 }
  73
  74 #define DEFINE_ALSA_IOCTL_BIG(type) \
  75 static int _snd_ioctl32_##type(unsigned int fd, unsigned int cmd, unsigned long arg, struct file *file, unsigned int native_ctl)\
  76 {\
  77         struct sndrv_##type##32 *data32;\
  78         struct sndrv_##type *data;\
  79         mm_segment_t oldseg;\
  80         int err;\
  81         data32 = kmalloc(sizeof(*data32), GFP_KERNEL); \
  82         data = kmalloc(sizeof(*data), GFP_KERNEL); \
  83         if (data32 == NULL || data == NULL) { \
  84                 err = -ENOMEM; \
  85                 goto __end; \
  86         }\
  87         if (copy_from_user(data32, (void __user *)arg, sizeof(*data32))) { \
  88                 err = -EFAULT; \
  89                 goto __end; \
  90         }\
  91         memset(data, 0, sizeof(*data));\
  92         convert_from_32(type, data, data32);\
  93         oldseg = get_fs();\
  94         set_fs(KERNEL_DS);\
  95         err = file->f_op->ioctl(file->f_dentry->d_inode, file, native_ctl, (unsigned long)data);\
  96         set_fs(oldseg);\
  97         if (err < 0) \
  98                 goto __end;\
  99         err = 0;\
 100         if (native_ctl & (_IOC_READ << _IOC_DIRSHIFT)) {\
 101                 convert_to_32(type, data32, data);\
 102                 if (copy_to_user((void __user *)arg, data32, sizeof(*data32)))\
 103                         err = -EFAULT;\
 104         }\
 105       __end:\
 106         if (data)\
 107                 kfree(data);\
 108         if (data32)\
 109                 kfree(data32);\
 110         return err;\
 111 }
 112
 113 #define DEFINE_ALSA_IOCTL_ENTRY(name,type,native_ctl) \
 114 static int snd_ioctl32_##name(unsigned int fd, unsigned int cmd, unsigned long arg, struct file *file) {\
 115         return _snd_ioctl32_##type(fd, cmd, arg, file, native_ctl);\
 116 }
 117
 118 #define MAP_COMPAT(ctl) { ctl, snd_ioctl32_compat }
 119
 120 struct ioctl32_mapper {
 121         unsigned int cmd;
 122         int (*handler)(unsigned int, unsigned int, unsigned long, struct file * filp);
 123         int registered;
 124 };
 125
 126 int snd_ioctl32_compat(unsigned int, unsigned int, unsigned long, struct file *);
 127
 128 int snd_ioctl32_register(struct ioctl32_mapper *mappers);
 129 void snd_ioctl32_unregister(struct ioctl32_mapper *mappers);
 130
 131 #endif /* __ALSA_IOCTL32_H */