drivers/staging/comedi/comedi_compat32.c

   1 /*
   2     comedi/comedi_compat32.c
   3     32-bit ioctl compatibility for 64-bit comedi kernel module.
   4
   5     Author: Ian Abbott, MEV Ltd. <abbotti@mev.co.uk>
   6     Copyright (C) 2007 MEV Ltd. <http://www.mev.co.uk/>
   7
   8     COMEDI - Linux Control and Measurement Device Interface
   9     Copyright (C) 1997-2007 David A. Schleef <ds@schleef.org>
  10
  11     This program is free software; you can redistribute it and/or modify
  12     it under the terms of the GNU General Public License as published by
  13     the Free Software Foundation; either version 2 of the License, or
  14     (at your option) any later version.
  15
  16     This program is distributed in the hope that it will be useful,
  17     but WITHOUT ANY WARRANTY; without even the implied warranty of
  18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19     GNU General Public License for more details.
  20 */
  21
  22 #include <linux/uaccess.h>
  23 #include <linux/compat.h>
  24 #include <linux/fs.h>
  25 #include "comedi.h"
  26 #include "comedi_compat32.h"
  27
  28 #define COMEDI32_CHANINFO _IOR(CIO, 3, struct comedi32_chaninfo_struct)
  29 #define COMEDI32_RANGEINFO _IOR(CIO, 8, struct comedi32_rangeinfo_struct)
  30 /* N.B. COMEDI32_CMD and COMEDI_CMD ought to use _IOWR, not _IOR.
  31  * It's too late to change it now, but it only affects the command number. */
  32 #define COMEDI32_CMD _IOR(CIO, 9, struct comedi32_cmd_struct)
  33 /* N.B. COMEDI32_CMDTEST and COMEDI_CMDTEST ought to use _IOWR, not _IOR.
  34  * It's too late to change it now, but it only affects the command number. */
  35 #define COMEDI32_CMDTEST _IOR(CIO, 10, struct comedi32_cmd_struct)
  36 #define COMEDI32_INSNLIST _IOR(CIO, 11, struct comedi32_insnlist_struct)
  37 #define COMEDI32_INSN _IOR(CIO, 12, struct comedi32_insn_struct)
  38
  39 struct comedi32_chaninfo_struct {
  40         unsigned int subdev;
  41         compat_uptr_t maxdata_list;     /* 32-bit 'unsigned int *' */
  42         compat_uptr_t flaglist; /* 32-bit 'unsigned int *' */
  43         compat_uptr_t rangelist;        /* 32-bit 'unsigned int *' */
  44         unsigned int unused[4];
  45 };
  46
  47 struct comedi32_rangeinfo_struct {
  48         unsigned int range_type;
  49         compat_uptr_t range_ptr;        /* 32-bit 'void *' */
  50 };
  51
  52 struct comedi32_cmd_struct {
  53         unsigned int subdev;
  54         unsigned int flags;
  55         unsigned int start_src;
  56         unsigned int start_arg;
  57         unsigned int scan_begin_src;
  58         unsigned int scan_begin_arg;
  59         unsigned int convert_src;
  60         unsigned int convert_arg;
  61         unsigned int scan_end_src;
  62         unsigned int scan_end_arg;
  63         unsigned int stop_src;
  64         unsigned int stop_arg;
  65         compat_uptr_t chanlist; /* 32-bit 'unsigned int *' */
  66         unsigned int chanlist_len;
  67         compat_uptr_t data;     /* 32-bit 'short *' */
  68         unsigned int data_len;
  69 };
  70
  71 struct comedi32_insn_struct {
  72         unsigned int insn;
  73         unsigned int n;
  74         compat_uptr_t data;     /* 32-bit 'unsigned int *' */
  75         unsigned int subdev;
  76         unsigned int chanspec;
  77         unsigned int unused[3];
  78 };
  79
  80 struct comedi32_insnlist_struct {
  81         unsigned int n_insns;
  82         compat_uptr_t insns;    /* 32-bit 'struct comedi_insn *' */
  83 };
  84
  85 /* Handle translated ioctl. */
  86 static int translated_ioctl(struct file *file, unsigned int cmd,
  87                             unsigned long arg)
  88 {
  89         if (file->f_op->unlocked_ioctl)
  90                 return file->f_op->unlocked_ioctl(file, cmd, arg);
  91
  92         return -ENOTTY;
  93 }
  94
  95 /* Handle 32-bit COMEDI_CHANINFO ioctl. */
  96 static int compat_chaninfo(struct file *file, unsigned long arg)
  97 {
  98         struct comedi_chaninfo __user *chaninfo;
  99         struct comedi32_chaninfo_struct __user *chaninfo32;
 100         int err;
 101         union {
 102                 unsigned int uint;
 103                 compat_uptr_t uptr;
 104         } temp;
 105
 106         chaninfo32 = compat_ptr(arg);
 107         chaninfo = compat_alloc_user_space(sizeof(*chaninfo));
 108
 109         /* Copy chaninfo structure.  Ignore unused members. */
 110         if (!access_ok(VERIFY_READ, chaninfo32, sizeof(*chaninfo32))
 111             || !access_ok(VERIFY_WRITE, chaninfo, sizeof(*chaninfo))) {
 112                 return -EFAULT;
 113         }
 114         err = 0;
 115         err |= __get_user(temp.uint, &chaninfo32->subdev);
 116         err |= __put_user(temp.uint, &chaninfo->subdev);
 117         err |= __get_user(temp.uptr, &chaninfo32->maxdata_list);
 118         err |= __put_user(compat_ptr(temp.uptr), &chaninfo->maxdata_list);
 119         err |= __get_user(temp.uptr, &chaninfo32->flaglist);
 120         err |= __put_user(compat_ptr(temp.uptr), &chaninfo->flaglist);
 121         err |= __get_user(temp.uptr, &chaninfo32->rangelist);
 122         err |= __put_user(compat_ptr(temp.uptr), &chaninfo->rangelist);
 123         if (err)
 124                 return -EFAULT;
 125
 126         return translated_ioctl(file, COMEDI_CHANINFO, (unsigned long)chaninfo);
 127 }
 128
 129 /* Handle 32-bit COMEDI_RANGEINFO ioctl. */
 130 static int compat_rangeinfo(struct file *file, unsigned long arg)
 131 {
 132         struct comedi_rangeinfo __user *rangeinfo;
 133         struct comedi32_rangeinfo_struct __user *rangeinfo32;
 134         int err;
 135         union {
 136                 unsigned int uint;
 137                 compat_uptr_t uptr;
 138         } temp;
 139
 140         rangeinfo32 = compat_ptr(arg);
 141         rangeinfo = compat_alloc_user_space(sizeof(*rangeinfo));
 142
 143         /* Copy rangeinfo structure. */
 144         if (!access_ok(VERIFY_READ, rangeinfo32, sizeof(*rangeinfo32))
 145             || !access_ok(VERIFY_WRITE, rangeinfo, sizeof(*rangeinfo))) {
 146                 return -EFAULT;
 147         }
 148         err = 0;
 149         err |= __get_user(temp.uint, &rangeinfo32->range_type);
 150         err |= __put_user(temp.uint, &rangeinfo->range_type);
 151         err |= __get_user(temp.uptr, &rangeinfo32->range_ptr);
 152         err |= __put_user(compat_ptr(temp.uptr), &rangeinfo->range_ptr);
 153         if (err)
 154                 return -EFAULT;
 155
 156         return translated_ioctl(file, COMEDI_RANGEINFO,
 157                                 (unsigned long)rangeinfo);
 158 }
 159
 160 /* Copy 32-bit cmd structure to native cmd structure. */
 161 static int get_compat_cmd(struct comedi_cmd __user *cmd,
 162                           struct comedi32_cmd_struct __user *cmd32)
 163 {
 164         int err;
 165         union {
 166                 unsigned int uint;
 167                 compat_uptr_t uptr;
 168         } temp;
 169
 170         /* Copy cmd structure. */
 171         if (!access_ok(VERIFY_READ, cmd32, sizeof(*cmd32))
 172             || !access_ok(VERIFY_WRITE, cmd, sizeof(*cmd))) {
 173                 return -EFAULT;
 174         }
 175         err = 0;
 176         err |= __get_user(temp.uint, &cmd32->subdev);
 177         err |= __put_user(temp.uint, &cmd->subdev);
 178         err |= __get_user(temp.uint, &cmd32->flags);
 179         err |= __put_user(temp.uint, &cmd->flags);
 180         err |= __get_user(temp.uint, &cmd32->start_src);
 181         err |= __put_user(temp.uint, &cmd->start_src);
 182         err |= __get_user(temp.uint, &cmd32->start_arg);
 183         err |= __put_user(temp.uint, &cmd->start_arg);
 184         err |= __get_user(temp.uint, &cmd32->scan_begin_src);
 185         err |= __put_user(temp.uint, &cmd->scan_begin_src);
 186         err |= __get_user(temp.uint, &cmd32->scan_begin_arg);
 187         err |= __put_user(temp.uint, &cmd->scan_begin_arg);
 188         err |= __get_user(temp.uint, &cmd32->convert_src);
 189         err |= __put_user(temp.uint, &cmd->convert_src);
 190         err |= __get_user(temp.uint, &cmd32->convert_arg);
 191         err |= __put_user(temp.uint, &cmd->convert_arg);
 192         err |= __get_user(temp.uint, &cmd32->scan_end_src);
 193         err |= __put_user(temp.uint, &cmd->scan_end_src);
 194         err |= __get_user(temp.uint, &cmd32->scan_end_arg);
 195         err |= __put_user(temp.uint, &cmd->scan_end_arg);
 196         err |= __get_user(temp.uint, &cmd32->stop_src);
 197         err |= __put_user(temp.uint, &cmd->stop_src);
 198         err |= __get_user(temp.uint, &cmd32->stop_arg);
 199         err |= __put_user(temp.uint, &cmd->stop_arg);
 200         err |= __get_user(temp.uptr, &cmd32->chanlist);
 201         err |= __put_user(compat_ptr(temp.uptr), &cmd->chanlist);
 202         err |= __get_user(temp.uint, &cmd32->chanlist_len);
 203         err |= __put_user(temp.uint, &cmd->chanlist_len);
 204         err |= __get_user(temp.uptr, &cmd32->data);
 205         err |= __put_user(compat_ptr(temp.uptr), &cmd->data);
 206         err |= __get_user(temp.uint, &cmd32->data_len);
 207         err |= __put_user(temp.uint, &cmd->data_len);
 208         return err ? -EFAULT : 0;
 209 }
 210
 211 /* Copy native cmd structure to 32-bit cmd structure. */
 212 static int put_compat_cmd(struct comedi32_cmd_struct __user *cmd32,
 213                           struct comedi_cmd __user *cmd)
 214 {
 215         int err;
 216         unsigned int temp;
 217
 218         /* Copy back most of cmd structure. */
 219         /* Assume the pointer values are already valid. */
 220         /* (Could use ptr_to_compat() to set them, but that wasn't implemented
 221          * until kernel version 2.6.11.) */
 222         if (!access_ok(VERIFY_READ, cmd, sizeof(*cmd))
 223             || !access_ok(VERIFY_WRITE, cmd32, sizeof(*cmd32))) {
 224                 return -EFAULT;
 225         }
 226         err = 0;
 227         err |= __get_user(temp, &cmd->subdev);
 228         err |= __put_user(temp, &cmd32->subdev);
 229         err |= __get_user(temp, &cmd->flags);
 230         err |= __put_user(temp, &cmd32->flags);
 231         err |= __get_user(temp, &cmd->start_src);
 232         err |= __put_user(temp, &cmd32->start_src);
 233         err |= __get_user(temp, &cmd->start_arg);
 234         err |= __put_user(temp, &cmd32->start_arg);
 235         err |= __get_user(temp, &cmd->scan_begin_src);
 236         err |= __put_user(temp, &cmd32->scan_begin_src);
 237         err |= __get_user(temp, &cmd->scan_begin_arg);
 238         err |= __put_user(temp, &cmd32->scan_begin_arg);
 239         err |= __get_user(temp, &cmd->convert_src);
 240         err |= __put_user(temp, &cmd32->convert_src);
 241         err |= __get_user(temp, &cmd->convert_arg);
 242         err |= __put_user(temp, &cmd32->convert_arg);
 243         err |= __get_user(temp, &cmd->scan_end_src);
 244         err |= __put_user(temp, &cmd32->scan_end_src);
 245         err |= __get_user(temp, &cmd->scan_end_arg);
 246         err |= __put_user(temp, &cmd32->scan_end_arg);
 247         err |= __get_user(temp, &cmd->stop_src);
 248         err |= __put_user(temp, &cmd32->stop_src);
 249         err |= __get_user(temp, &cmd->stop_arg);
 250         err |= __put_user(temp, &cmd32->stop_arg);
 251         /* Assume chanlist pointer is unchanged. */
 252         err |= __get_user(temp, &cmd->chanlist_len);
 253         err |= __put_user(temp, &cmd32->chanlist_len);
 254         /* Assume data pointer is unchanged. */
 255         err |= __get_user(temp, &cmd->data_len);
 256         err |= __put_user(temp, &cmd32->data_len);
 257         return err ? -EFAULT : 0;
 258 }
 259
 260 /* Handle 32-bit COMEDI_CMD ioctl. */
 261 static int compat_cmd(struct file *file, unsigned long arg)
 262 {
 263         struct comedi_cmd __user *cmd;
 264         struct comedi32_cmd_struct __user *cmd32;
 265         int rc;
 266
 267         cmd32 = compat_ptr(arg);
 268         cmd = compat_alloc_user_space(sizeof(*cmd));
 269
 270         rc = get_compat_cmd(cmd, cmd32);
 271         if (rc)
 272                 return rc;
 273
 274         return translated_ioctl(file, COMEDI_CMD, (unsigned long)cmd);
 275 }
 276
 277 /* Handle 32-bit COMEDI_CMDTEST ioctl. */
 278 static int compat_cmdtest(struct file *file, unsigned long arg)
 279 {
 280         struct comedi_cmd __user *cmd;
 281         struct comedi32_cmd_struct __user *cmd32;
 282         int rc, err;
 283
 284         cmd32 = compat_ptr(arg);
 285         cmd = compat_alloc_user_space(sizeof(*cmd));
 286
 287         rc = get_compat_cmd(cmd, cmd32);
 288         if (rc)
 289                 return rc;
 290
 291         rc = translated_ioctl(file, COMEDI_CMDTEST, (unsigned long)cmd);
 292         if (rc < 0)
 293                 return rc;
 294
 295         err = put_compat_cmd(cmd32, cmd);
 296         if (err)
 297                 rc = err;
 298
 299         return rc;
 300 }
 301
 302 /* Copy 32-bit insn structure to native insn structure. */
 303 static int get_compat_insn(struct comedi_insn __user *insn,
 304                            struct comedi32_insn_struct __user *insn32)
 305 {
 306         int err;
 307         union {
 308                 unsigned int uint;
 309                 compat_uptr_t uptr;
 310         } temp;
 311
 312         /* Copy insn structure.  Ignore the unused members. */
 313         err = 0;
 314         if (!access_ok(VERIFY_READ, insn32, sizeof(*insn32))
 315             || !access_ok(VERIFY_WRITE, insn, sizeof(*insn)))
 316                 return -EFAULT;
 317
 318         err |= __get_user(temp.uint, &insn32->insn);
 319         err |= __put_user(temp.uint, &insn->insn);
 320         err |= __get_user(temp.uint, &insn32->n);
 321         err |= __put_user(temp.uint, &insn->n);
 322         err |= __get_user(temp.uptr, &insn32->data);
 323         err |= __put_user(compat_ptr(temp.uptr), &insn->data);
 324         err |= __get_user(temp.uint, &insn32->subdev);
 325         err |= __put_user(temp.uint, &insn->subdev);
 326         err |= __get_user(temp.uint, &insn32->chanspec);
 327         err |= __put_user(temp.uint, &insn->chanspec);
 328         return err ? -EFAULT : 0;
 329 }
 330
 331 /* Handle 32-bit COMEDI_INSNLIST ioctl. */
 332 static int compat_insnlist(struct file *file, unsigned long arg)
 333 {
 334         struct combined_insnlist {
 335                 struct comedi_insnlist insnlist;
 336                 struct comedi_insn insn[1];
 337         } __user *s;
 338         struct comedi32_insnlist_struct __user *insnlist32;
 339         struct comedi32_insn_struct __user *insn32;
 340         compat_uptr_t uptr;
 341         unsigned int n_insns, n;
 342         int err, rc;
 343
 344         insnlist32 = compat_ptr(arg);
 345
 346         /* Get 32-bit insnlist structure.  */
 347         if (!access_ok(VERIFY_READ, insnlist32, sizeof(*insnlist32)))
 348                 return -EFAULT;
 349
 350         err = 0;
 351         err |= __get_user(n_insns, &insnlist32->n_insns);
 352         err |= __get_user(uptr, &insnlist32->insns);
 353         insn32 = compat_ptr(uptr);
 354         if (err)
 355                 return -EFAULT;
 356
 357         /* Allocate user memory to copy insnlist and insns into. */
 358         s = compat_alloc_user_space(offsetof(struct combined_insnlist,
 359                                              insn[n_insns]));
 360
 361         /* Set native insnlist structure. */
 362         if (!access_ok(VERIFY_WRITE, &s->insnlist, sizeof(s->insnlist)))
 363                 return -EFAULT;
 364
 365         err |= __put_user(n_insns, &s->insnlist.n_insns);
 366         err |= __put_user(&s->insn[0], &s->insnlist.insns);
 367         if (err)
 368                 return -EFAULT;
 369
 370         /* Copy insn structures. */
 371         for (n = 0; n < n_insns; n++) {
 372                 rc = get_compat_insn(&s->insn[n], &insn32[n]);
 373                 if (rc)
 374                         return rc;
 375         }
 376
 377         return translated_ioctl(file, COMEDI_INSNLIST,
 378                                 (unsigned long)&s->insnlist);
 379 }
 380
 381 /* Handle 32-bit COMEDI_INSN ioctl. */
 382 static int compat_insn(struct file *file, unsigned long arg)
 383 {
 384         struct comedi_insn __user *insn;
 385         struct comedi32_insn_struct __user *insn32;
 386         int rc;
 387
 388         insn32 = compat_ptr(arg);
 389         insn = compat_alloc_user_space(sizeof(*insn));
 390
 391         rc = get_compat_insn(insn, insn32);
 392         if (rc)
 393                 return rc;
 394
 395         return translated_ioctl(file, COMEDI_INSN, (unsigned long)insn);
 396 }
 397
 398 /* Process untranslated ioctl. */
 399 /* Returns -ENOIOCTLCMD for unrecognised ioctl codes. */
 400 static inline int raw_ioctl(struct file *file, unsigned int cmd,
 401                             unsigned long arg)
 402 {
 403         int rc;
 404
 405         switch (cmd) {
 406         case COMEDI_DEVCONFIG:
 407         case COMEDI_DEVINFO:
 408         case COMEDI_SUBDINFO:
 409         case COMEDI_BUFCONFIG:
 410         case COMEDI_BUFINFO:
 411                 /* Just need to translate the pointer argument. */
 412                 arg = (unsigned long)compat_ptr(arg);
 413                 rc = translated_ioctl(file, cmd, arg);
 414                 break;
 415         case COMEDI_LOCK:
 416         case COMEDI_UNLOCK:
 417         case COMEDI_CANCEL:
 418         case COMEDI_POLL:
 419                 /* No translation needed. */
 420                 rc = translated_ioctl(file, cmd, arg);
 421                 break;
 422         case COMEDI32_CHANINFO:
 423                 rc = compat_chaninfo(file, arg);
 424                 break;
 425         case COMEDI32_RANGEINFO:
 426                 rc = compat_rangeinfo(file, arg);
 427                 break;
 428         case COMEDI32_CMD:
 429                 rc = compat_cmd(file, arg);
 430                 break;
 431         case COMEDI32_CMDTEST:
 432                 rc = compat_cmdtest(file, arg);
 433                 break;
 434         case COMEDI32_INSNLIST:
 435                 rc = compat_insnlist(file, arg);
 436                 break;
 437         case COMEDI32_INSN:
 438                 rc = compat_insn(file, arg);
 439                 break;
 440         default:
 441                 rc = -ENOIOCTLCMD;
 442                 break;
 443         }
 444         return rc;
 445 }
 446
 447 /* compat_ioctl file operation. */
 448 /* Returns -ENOIOCTLCMD for unrecognised ioctl codes. */
 449 long comedi_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 450 {
 451         return raw_ioctl(file, cmd, arg);
 452 }