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     You should have received a copy of the GNU General Public License
  22     along with this program; if not, write to the Free Software
  23     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24
  25 */
  26
  27 #define __NO_VERSION__
  28 #include "comedi.h"
  29 #include <linux/smp_lock.h>
  30 #include <linux/uaccess.h>
  31
  32 #include "comedi_compat32.h"
  33
  34 #ifdef CONFIG_COMPAT
  35
  36 #define COMEDI32_CHANINFO _IOR(CIO, 3, struct comedi32_chaninfo_struct)
  37 #define COMEDI32_RANGEINFO _IOR(CIO, 8, struct comedi32_rangeinfo_struct)
  38 /* N.B. COMEDI32_CMD and COMEDI_CMD ought to use _IOWR, not _IOR.
  39  * It's too late to change it now, but it only affects the command number. */
  40 #define COMEDI32_CMD _IOR(CIO, 9, struct comedi32_cmd_struct)
  41 /* N.B. COMEDI32_CMDTEST and COMEDI_CMDTEST ought to use _IOWR, not _IOR.
  42  * It's too late to change it now, but it only affects the command number. */
  43 #define COMEDI32_CMDTEST _IOR(CIO, 10, struct comedi32_cmd_struct)
  44 #define COMEDI32_INSNLIST _IOR(CIO, 11, struct comedi32_insnlist_struct)
  45 #define COMEDI32_INSN _IOR(CIO, 12, struct comedi32_insn_struct)
  46
  47 struct comedi32_chaninfo_struct {
  48         unsigned int subdev;
  49         compat_uptr_t maxdata_list;     /* 32-bit 'unsigned int *' */
  50         compat_uptr_t flaglist; /* 32-bit 'unsigned int *' */
  51         compat_uptr_t rangelist;        /* 32-bit 'unsigned int *' */
  52         unsigned int unused[4];
  53 };
  54
  55 struct comedi32_rangeinfo_struct {
  56         unsigned int range_type;
  57         compat_uptr_t range_ptr;        /* 32-bit 'void *' */
  58 };
  59
  60 struct comedi32_cmd_struct {
  61         unsigned int subdev;
  62         unsigned int flags;
  63         unsigned int start_src;
  64         unsigned int start_arg;
  65         unsigned int scan_begin_src;
  66         unsigned int scan_begin_arg;
  67         unsigned int convert_src;
  68         unsigned int convert_arg;
  69         unsigned int scan_end_src;
  70         unsigned int scan_end_arg;
  71         unsigned int stop_src;
  72         unsigned int stop_arg;
  73         compat_uptr_t chanlist; /* 32-bit 'unsigned int *' */
  74         unsigned int chanlist_len;
  75         compat_uptr_t data;     /* 32-bit 'short *' */
  76         unsigned int data_len;
  77 };
  78
  79 struct comedi32_insn_struct {
  80         unsigned int insn;
  81         unsigned int n;
  82         compat_uptr_t data;     /* 32-bit 'unsigned int *' */
  83         unsigned int subdev;
  84         unsigned int chanspec;
  85         unsigned int unused[3];
  86 };
  87
  88 struct comedi32_insnlist_struct {
  89         unsigned int n_insns;
  90         compat_uptr_t insns;    /* 32-bit 'struct comedi_insn *' */
  91 };
  92
  93 /* Handle translated ioctl. */
  94 static int translated_ioctl(struct file *file, unsigned int cmd,
  95                             unsigned long arg)
  96 {
  97         if (!file->f_op)
  98                 return -ENOTTY;
  99
 100         if (file->f_op->unlocked_ioctl)
 101                 return file->f_op->unlocked_ioctl(file, cmd, arg);
 102
 103         return -ENOTTY;
 104 }
 105
 106 /* Handle 32-bit COMEDI_CHANINFO ioctl. */
 107 static int compat_chaninfo(struct file *file, unsigned long arg)
 108 {
 109         struct comedi_chaninfo __user *chaninfo;
 110         struct comedi32_chaninfo_struct __user *chaninfo32;
 111         int err;
 112         union {
 113                 unsigned int uint;
 114                 compat_uptr_t uptr;
 115         } temp;
 116
 117         chaninfo32 = compat_ptr(arg);
 118         chaninfo = compat_alloc_user_space(sizeof(*chaninfo));
 119
 120         /* Copy chaninfo structure.  Ignore unused members. */
 121         if (!access_ok(VERIFY_READ, chaninfo32, sizeof(*chaninfo32))
 122             || !access_ok(VERIFY_WRITE, chaninfo, sizeof(*chaninfo))) {
 123                 return -EFAULT;
 124         }
 125         err = 0;
 126         err |= __get_user(temp.uint, &chaninfo32->subdev);
 127         err |= __put_user(temp.uint, &chaninfo->subdev);
 128         err |= __get_user(temp.uptr, &chaninfo32->maxdata_list);
 129         err |= __put_user(compat_ptr(temp.uptr), &chaninfo->maxdata_list);
 130         err |= __get_user(temp.uptr, &chaninfo32->flaglist);
 131         err |= __put_user(compat_ptr(temp.uptr), &chaninfo->flaglist);
 132         err |= __get_user(temp.uptr, &chaninfo32->rangelist);
 133         err |= __put_user(compat_ptr(temp.uptr), &chaninfo->rangelist);
 134         if (err)
 135                 return -EFAULT;
 136
 137         return translated_ioctl(file, COMEDI_CHANINFO, (unsigned long)chaninfo);
 138 }
 139
 140 /* Handle 32-bit COMEDI_RANGEINFO ioctl. */
 141 static int compat_rangeinfo(struct file *file, unsigned long arg)
 142 {
 143         struct comedi_rangeinfo __user *rangeinfo;
 144         struct comedi32_rangeinfo_struct __user *rangeinfo32;
 145         int err;
 146         union {
 147                 unsigned int uint;
 148                 compat_uptr_t uptr;
 149         } temp;
 150
 151         rangeinfo32 = compat_ptr(arg);
 152         rangeinfo = compat_alloc_user_space(sizeof(*rangeinfo));
 153
 154         /* Copy rangeinfo structure. */
 155         if (!access_ok(VERIFY_READ, rangeinfo32, sizeof(*rangeinfo32))
 156             || !access_ok(VERIFY_WRITE, rangeinfo, sizeof(*rangeinfo))) {
 157                 return -EFAULT;
 158         }
 159         err = 0;
 160         err |= __get_user(temp.uint, &rangeinfo32->range_type);
 161         err |= __put_user(temp.uint, &rangeinfo->range_type);
 162         err |= __get_user(temp.uptr, &rangeinfo32->range_ptr);
 163         err |= __put_user(compat_ptr(temp.uptr), &rangeinfo->range_ptr);
 164         if (err)
 165                 return -EFAULT;
 166
 167         return translated_ioctl(file, COMEDI_RANGEINFO,
 168                                 (unsigned long)rangeinfo);
 169 }
 170
 171 /* Copy 32-bit cmd structure to native cmd structure. */
 172 static int get_compat_cmd(struct comedi_cmd __user *cmd,
 173                           struct comedi32_cmd_struct __user *cmd32)
 174 {
 175         int err;
 176         union {
 177                 unsigned int uint;
 178                 compat_uptr_t uptr;
 179         } temp;
 180
 181         /* Copy cmd structure. */
 182         if (!access_ok(VERIFY_READ, cmd32, sizeof(*cmd32))
 183             || !access_ok(VERIFY_WRITE, cmd, sizeof(*cmd))) {
 184                 return -EFAULT;
 185         }
 186         err = 0;
 187         err |= __get_user(temp.uint, &cmd32->subdev);
 188         err |= __put_user(temp.uint, &cmd->subdev);
 189         err |= __get_user(temp.uint, &cmd32->flags);
 190         err |= __put_user(temp.uint, &cmd->flags);
 191         err |= __get_user(temp.uint, &cmd32->start_src);
 192         err |= __put_user(temp.uint, &cmd->start_src);
 193         err |= __get_user(temp.uint, &cmd32->start_arg);
 194         err |= __put_user(temp.uint, &cmd->start_arg);
 195         err |= __get_user(temp.uint, &cmd32->scan_begin_src);
 196         err |= __put_user(temp.uint, &cmd->scan_begin_src);
 197         err |= __get_user(temp.uint, &cmd32->scan_begin_arg);
 198         err |= __put_user(temp.uint, &cmd->scan_begin_arg);
 199         err |= __get_user(temp.uint, &cmd32->convert_src);
 200         err |= __put_user(temp.uint, &cmd->convert_src);
 201         err |= __get_user(temp.uint, &cmd32->convert_arg);
 202         err |= __put_user(temp.uint, &cmd->convert_arg);
 203         err |= __get_user(temp.uint, &cmd32->scan_end_src);
 204         err |= __put_user(temp.uint, &cmd->scan_end_src);
 205         err |= __get_user(temp.uint, &cmd32->scan_end_arg);
 206         err |= __put_user(temp.uint, &cmd->scan_end_arg);
 207         err |= __get_user(temp.uint, &cmd32->stop_src);
 208         err |= __put_user(temp.uint, &cmd->stop_src);
 209         err |= __get_user(temp.uint, &cmd32->stop_arg);
 210         err |= __put_user(temp.uint, &cmd->stop_arg);
 211         err |= __get_user(temp.uptr, &cmd32->chanlist);
 212         err |= __put_user(compat_ptr(temp.uptr), &cmd->chanlist);
 213         err |= __get_user(temp.uint, &cmd32->chanlist_len);
 214         err |= __put_user(temp.uint, &cmd->chanlist_len);
 215         err |= __get_user(temp.uptr, &cmd32->data);
 216         err |= __put_user(compat_ptr(temp.uptr), &cmd->data);
 217         err |= __get_user(temp.uint, &cmd32->data_len);
 218         err |= __put_user(temp.uint, &cmd->data_len);
 219         return err ? -EFAULT : 0;
 220 }
 221
 222 /* Copy native cmd structure to 32-bit cmd structure. */
 223 static int put_compat_cmd(struct comedi32_cmd_struct __user *cmd32,
 224                           struct comedi_cmd __user *cmd)
 225 {
 226         int err;
 227         unsigned int temp;
 228
 229         /* Copy back most of cmd structure. */
 230         /* Assume the pointer values are already valid. */
 231         /* (Could use ptr_to_compat() to set them, but that wasn't implemented
 232          * until kernel version 2.6.11.) */
 233         if (!access_ok(VERIFY_READ, cmd, sizeof(*cmd))
 234             || !access_ok(VERIFY_WRITE, cmd32, sizeof(*cmd32))) {
 235                 return -EFAULT;
 236         }
 237         err = 0;
 238         err |= __get_user(temp, &cmd->subdev);
 239         err |= __put_user(temp, &cmd32->subdev);
 240         err |= __get_user(temp, &cmd->flags);
 241         err |= __put_user(temp, &cmd32->flags);
 242         err |= __get_user(temp, &cmd->start_src);
 243         err |= __put_user(temp, &cmd32->start_src);
 244         err |= __get_user(temp, &cmd->start_arg);
 245         err |= __put_user(temp, &cmd32->start_arg);
 246         err |= __get_user(temp, &cmd->scan_begin_src);
 247         err |= __put_user(temp, &cmd32->scan_begin_src);
 248         err |= __get_user(temp, &cmd->scan_begin_arg);
 249         err |= __put_user(temp, &cmd32->scan_begin_arg);
 250         err |= __get_user(temp, &cmd->convert_src);
 251         err |= __put_user(temp, &cmd32->convert_src);
 252         err |= __get_user(temp, &cmd->convert_arg);
 253         err |= __put_user(temp, &cmd32->convert_arg);
 254         err |= __get_user(temp, &cmd->scan_end_src);
 255         err |= __put_user(temp, &cmd32->scan_end_src);
 256         err |= __get_user(temp, &cmd->scan_end_arg);
 257         err |= __put_user(temp, &cmd32->scan_end_arg);
 258         err |= __get_user(temp, &cmd->stop_src);
 259         err |= __put_user(temp, &cmd32->stop_src);
 260         err |= __get_user(temp, &cmd->stop_arg);
 261         err |= __put_user(temp, &cmd32->stop_arg);
 262         /* Assume chanlist pointer is unchanged. */
 263         err |= __get_user(temp, &cmd->chanlist_len);
 264         err |= __put_user(temp, &cmd32->chanlist_len);
 265         /* Assume data pointer is unchanged. */
 266         err |= __get_user(temp, &cmd->data_len);
 267         err |= __put_user(temp, &cmd32->data_len);
 268         return err ? -EFAULT : 0;
 269 }
 270
 271 /* Handle 32-bit COMEDI_CMD ioctl. */
 272 static int compat_cmd(struct file *file, unsigned long arg)
 273 {
 274         struct comedi_cmd __user *cmd;
 275         struct comedi32_cmd_struct __user *cmd32;
 276         int rc;
 277
 278         cmd32 = compat_ptr(arg);
 279         cmd = compat_alloc_user_space(sizeof(*cmd));
 280
 281         rc = get_compat_cmd(cmd, cmd32);
 282         if (rc)
 283                 return rc;
 284
 285         return translated_ioctl(file, COMEDI_CMD, (unsigned long)cmd);
 286 }
 287
 288 /* Handle 32-bit COMEDI_CMDTEST ioctl. */
 289 static int compat_cmdtest(struct file *file, unsigned long arg)
 290 {
 291         struct comedi_cmd __user *cmd;
 292         struct comedi32_cmd_struct __user *cmd32;
 293         int rc, err;
 294
 295         cmd32 = compat_ptr(arg);
 296         cmd = compat_alloc_user_space(sizeof(*cmd));
 297
 298         rc = get_compat_cmd(cmd, cmd32);
 299         if (rc)
 300                 return rc;
 301
 302         rc = translated_ioctl(file, COMEDI_CMDTEST, (unsigned long)cmd);
 303         if (rc < 0)
 304                 return rc;
 305
 306         err = put_compat_cmd(cmd32, cmd);
 307         if (err)
 308                 rc = err;
 309
 310         return rc;
 311 }
 312
 313 /* Copy 32-bit insn structure to native insn structure. */
 314 static int get_compat_insn(struct comedi_insn __user *insn,
 315                            struct comedi32_insn_struct __user *insn32)
 316 {
 317         int err;
 318         union {
 319                 unsigned int uint;
 320                 compat_uptr_t uptr;
 321         } temp;
 322
 323         /* Copy insn structure.  Ignore the unused members. */
 324         err = 0;
 325         if (!access_ok(VERIFY_READ, insn32, sizeof(*insn32))
 326             || !access_ok(VERIFY_WRITE, insn, sizeof(*insn)))
 327                 return -EFAULT;
 328
 329         err |= __get_user(temp.uint, &insn32->insn);
 330         err |= __put_user(temp.uint, &insn->insn);
 331         err |= __get_user(temp.uint, &insn32->n);
 332         err |= __put_user(temp.uint, &insn->n);
 333         err |= __get_user(temp.uptr, &insn32->data);
 334         err |= __put_user(compat_ptr(temp.uptr), &insn->data);
 335         err |= __get_user(temp.uint, &insn32->subdev);
 336         err |= __put_user(temp.uint, &insn->subdev);
 337         err |= __get_user(temp.uint, &insn32->chanspec);
 338         err |= __put_user(temp.uint, &insn->chanspec);
 339         return err ? -EFAULT : 0;
 340 }
 341
 342 /* Handle 32-bit COMEDI_INSNLIST ioctl. */
 343 static int compat_insnlist(struct file *file, unsigned long arg)
 344 {
 345         struct combined_insnlist {
 346                 struct comedi_insnlist insnlist;
 347                 struct comedi_insn insn[1];
 348         } __user *s;
 349         struct comedi32_insnlist_struct __user *insnlist32;
 350         struct comedi32_insn_struct __user *insn32;
 351         compat_uptr_t uptr;
 352         unsigned int n_insns, n;
 353         int err, rc;
 354
 355         insnlist32 = compat_ptr(arg);
 356
 357         /* Get 32-bit insnlist structure.  */
 358         if (!access_ok(VERIFY_READ, insnlist32, sizeof(*insnlist32)))
 359                 return -EFAULT;
 360
 361         err = 0;
 362         err |= __get_user(n_insns, &insnlist32->n_insns);
 363         err |= __get_user(uptr, &insnlist32->insns);
 364         insn32 = compat_ptr(uptr);
 365         if (err)
 366                 return -EFAULT;
 367
 368         /* Allocate user memory to copy insnlist and insns into. */
 369         s = compat_alloc_user_space(offsetof(struct combined_insnlist,
 370                                              insn[n_insns]));
 371
 372         /* Set native insnlist structure. */
 373         if (!access_ok(VERIFY_WRITE, &s->insnlist, sizeof(s->insnlist)))
 374                 return -EFAULT;
 375
 376         err |= __put_user(n_insns, &s->insnlist.n_insns);
 377         err |= __put_user(&s->insn[0], &s->insnlist.insns);
 378         if (err)
 379                 return -EFAULT;
 380
 381         /* Copy insn structures. */
 382         for (n = 0; n < n_insns; n++) {
 383                 rc = get_compat_insn(&s->insn[n], &insn32[n]);
 384                 if (rc)
 385                         return rc;
 386         }
 387
 388         return translated_ioctl(file, COMEDI_INSNLIST,
 389                                 (unsigned long)&s->insnlist);
 390 }
 391
 392 /* Handle 32-bit COMEDI_INSN ioctl. */
 393 static int compat_insn(struct file *file, unsigned long arg)
 394 {
 395         struct comedi_insn __user *insn;
 396         struct comedi32_insn_struct __user *insn32;
 397         int rc;
 398
 399         insn32 = compat_ptr(arg);
 400         insn = compat_alloc_user_space(sizeof(*insn));
 401
 402         rc = get_compat_insn(insn, insn32);
 403         if (rc)
 404                 return rc;
 405
 406         return translated_ioctl(file, COMEDI_INSN, (unsigned long)insn);
 407 }
 408
 409 /* Process untranslated ioctl. */
 410 /* Returns -ENOIOCTLCMD for unrecognised ioctl codes. */
 411 static inline int raw_ioctl(struct file *file, unsigned int cmd,
 412                             unsigned long arg)
 413 {
 414         int rc;
 415
 416         switch (cmd) {
 417         case COMEDI_DEVCONFIG:
 418         case COMEDI_DEVINFO:
 419         case COMEDI_SUBDINFO:
 420         case COMEDI_BUFCONFIG:
 421         case COMEDI_BUFINFO:
 422                 /* Just need to translate the pointer argument. */
 423                 arg = (unsigned long)compat_ptr(arg);
 424                 rc = translated_ioctl(file, cmd, arg);
 425                 break;
 426         case COMEDI_LOCK:
 427         case COMEDI_UNLOCK:
 428         case COMEDI_CANCEL:
 429         case COMEDI_POLL:
 430                 /* No translation needed. */
 431                 rc = translated_ioctl(file, cmd, arg);
 432                 break;
 433         case COMEDI32_CHANINFO:
 434                 rc = compat_chaninfo(file, arg);
 435                 break;
 436         case COMEDI32_RANGEINFO:
 437                 rc = compat_rangeinfo(file, arg);
 438                 break;
 439         case COMEDI32_CMD:
 440                 rc = compat_cmd(file, arg);
 441                 break;
 442         case COMEDI32_CMDTEST:
 443                 rc = compat_cmdtest(file, arg);
 444                 break;
 445         case COMEDI32_INSNLIST:
 446                 rc = compat_insnlist(file, arg);
 447                 break;
 448         case COMEDI32_INSN:
 449                 rc = compat_insn(file, arg);
 450                 break;
 451         default:
 452                 rc = -ENOIOCTLCMD;
 453                 break;
 454         }
 455         return rc;
 456 }
 457
 458 /* compat_ioctl file operation. */
 459 /* Returns -ENOIOCTLCMD for unrecognised ioctl codes. */
 460 long comedi_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 461 {
 462         return raw_ioctl(file, cmd, arg);
 463 }
 464
 465 #endif /* CONFIG_COMPAT */