drivers/firmware/efi/test/efi_test.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * EFI Test Driver for Runtime Services
   4  *
   5  * Copyright(C) 2012-2016 Canonical Ltd.
   6  *
   7  * This driver exports EFI runtime services interfaces into userspace, which
   8  * allow to use and test UEFI runtime services provided by firmware.
   9  *
  10  */
  11
  12 #include <linux/miscdevice.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/proc_fs.h>
  16 #include <linux/efi.h>
  17 #include <linux/slab.h>
  18 #include <linux/uaccess.h>
  19
  20 #include "efi_test.h"
  21
  22 MODULE_AUTHOR("Ivan Hu <ivan.hu@canonical.com>");
  23 MODULE_DESCRIPTION("EFI Test Driver");
  24 MODULE_LICENSE("GPL");
  25
  26 /*
  27  * Count the bytes in 'str', including the terminating NULL.
  28  *
  29  * Note this function returns the number of *bytes*, not the number of
  30  * ucs2 characters.
  31  */
  32 static inline size_t user_ucs2_strsize(efi_char16_t  __user *str)
  33 {
  34         efi_char16_t *s = str, c;
  35         size_t len;
  36
  37         if (!str)
  38                 return 0;
  39
  40         /* Include terminating NULL */
  41         len = sizeof(efi_char16_t);
  42
  43         if (get_user(c, s++)) {
  44                 /* Can't read userspace memory for size */
  45                 return 0;
  46         }
  47
  48         while (c != 0) {
  49                 if (get_user(c, s++)) {
  50                         /* Can't read userspace memory for size */
  51                         return 0;
  52                 }
  53                 len += sizeof(efi_char16_t);
  54         }
  55         return len;
  56 }
  57
  58 /*
  59  * Allocate a buffer and copy a ucs2 string from user space into it.
  60  */
  61 static inline int
  62 copy_ucs2_from_user_len(efi_char16_t **dst, efi_char16_t __user *src,
  63                         size_t len)
  64 {
  65         efi_char16_t *buf;
  66
  67         if (!src) {
  68                 *dst = NULL;
  69                 return 0;
  70         }
  71
  72         if (!access_ok(src, 1))
  73                 return -EFAULT;
  74
  75         buf = memdup_user(src, len);
  76         if (IS_ERR(buf)) {
  77                 *dst = NULL;
  78                 return PTR_ERR(buf);
  79         }
  80         *dst = buf;
  81
  82         return 0;
  83 }
  84
  85 /*
  86  * Count the bytes in 'str', including the terminating NULL.
  87  *
  88  * Just a wrap for user_ucs2_strsize
  89  */
  90 static inline int
  91 get_ucs2_strsize_from_user(efi_char16_t __user *src, size_t *len)
  92 {
  93         if (!access_ok(src, 1))
  94                 return -EFAULT;
  95
  96         *len = user_ucs2_strsize(src);
  97         if (*len == 0)
  98                 return -EFAULT;
  99
 100         return 0;
 101 }
 102
 103 /*
 104  * Calculate the required buffer allocation size and copy a ucs2 string
 105  * from user space into it.
 106  *
 107  * This function differs from copy_ucs2_from_user_len() because it
 108  * calculates the size of the buffer to allocate by taking the length of
 109  * the string 'src'.
 110  *
 111  * If a non-zero value is returned, the caller MUST NOT access 'dst'.
 112  *
 113  * It is the caller's responsibility to free 'dst'.
 114  */
 115 static inline int
 116 copy_ucs2_from_user(efi_char16_t **dst, efi_char16_t __user *src)
 117 {
 118         size_t len;
 119
 120         if (!access_ok(src, 1))
 121                 return -EFAULT;
 122
 123         len = user_ucs2_strsize(src);
 124         if (len == 0)
 125                 return -EFAULT;
 126         return copy_ucs2_from_user_len(dst, src, len);
 127 }
 128
 129 /*
 130  * Copy a ucs2 string to a user buffer.
 131  *
 132  * This function is a simple wrapper around copy_to_user() that does
 133  * nothing if 'src' is NULL, which is useful for reducing the amount of
 134  * NULL checking the caller has to do.
 135  *
 136  * 'len' specifies the number of bytes to copy.
 137  */
 138 static inline int
 139 copy_ucs2_to_user_len(efi_char16_t __user *dst, efi_char16_t *src, size_t len)
 140 {
 141         if (!src)
 142                 return 0;
 143
 144         if (!access_ok(dst, 1))
 145                 return -EFAULT;
 146
 147         return copy_to_user(dst, src, len);
 148 }
 149
 150 static long efi_runtime_get_variable(unsigned long arg)
 151 {
 152         struct efi_getvariable __user *getvariable_user;
 153         struct efi_getvariable getvariable;
 154         unsigned long datasize = 0, prev_datasize, *dz;
 155         efi_guid_t vendor_guid, *vd = NULL;
 156         efi_status_t status;
 157         efi_char16_t *name = NULL;
 158         u32 attr, *at;
 159         void *data = NULL;
 160         int rv = 0;
 161
 162         getvariable_user = (struct efi_getvariable __user *)arg;
 163
 164         if (copy_from_user(&getvariable, getvariable_user,
 165                            sizeof(getvariable)))
 166                 return -EFAULT;
 167         if (getvariable.data_size &&
 168             get_user(datasize, getvariable.data_size))
 169                 return -EFAULT;
 170         if (getvariable.vendor_guid) {
 171                 if (copy_from_user(&vendor_guid, getvariable.vendor_guid,
 172                                         sizeof(vendor_guid)))
 173                         return -EFAULT;
 174                 vd = &vendor_guid;
 175         }
 176
 177         if (getvariable.variable_name) {
 178                 rv = copy_ucs2_from_user(&name, getvariable.variable_name);
 179                 if (rv)
 180                         return rv;
 181         }
 182
 183         at = getvariable.attributes ? &attr : NULL;
 184         dz = getvariable.data_size ? &datasize : NULL;
 185
 186         if (getvariable.data_size && getvariable.data) {
 187                 data = kmalloc(datasize, GFP_KERNEL);
 188                 if (!data) {
 189                         kfree(name);
 190                         return -ENOMEM;
 191                 }
 192         }
 193
 194         prev_datasize = datasize;
 195         status = efi.get_variable(name, vd, at, dz, data);
 196         kfree(name);
 197
 198         if (put_user(status, getvariable.status)) {
 199                 rv = -EFAULT;
 200                 goto out;
 201         }
 202
 203         if (status != EFI_SUCCESS) {
 204                 if (status == EFI_BUFFER_TOO_SMALL) {
 205                         if (dz && put_user(datasize, getvariable.data_size)) {
 206                                 rv = -EFAULT;
 207                                 goto out;
 208                         }
 209                 }
 210                 rv = -EINVAL;
 211                 goto out;
 212         }
 213
 214         if (prev_datasize < datasize) {
 215                 rv = -EINVAL;
 216                 goto out;
 217         }
 218
 219         if (data) {
 220                 if (copy_to_user(getvariable.data, data, datasize)) {
 221                         rv = -EFAULT;
 222                         goto out;
 223                 }
 224         }
 225
 226         if (at && put_user(attr, getvariable.attributes)) {
 227                 rv = -EFAULT;
 228                 goto out;
 229         }
 230
 231         if (dz && put_user(datasize, getvariable.data_size))
 232                 rv = -EFAULT;
 233
 234 out:
 235         kfree(data);
 236         return rv;
 237
 238 }
 239
 240 static long efi_runtime_set_variable(unsigned long arg)
 241 {
 242         struct efi_setvariable __user *setvariable_user;
 243         struct efi_setvariable setvariable;
 244         efi_guid_t vendor_guid;
 245         efi_status_t status;
 246         efi_char16_t *name = NULL;
 247         void *data;
 248         int rv = 0;
 249
 250         setvariable_user = (struct efi_setvariable __user *)arg;
 251
 252         if (copy_from_user(&setvariable, setvariable_user, sizeof(setvariable)))
 253                 return -EFAULT;
 254         if (copy_from_user(&vendor_guid, setvariable.vendor_guid,
 255                                 sizeof(vendor_guid)))
 256                 return -EFAULT;
 257
 258         if (setvariable.variable_name) {
 259                 rv = copy_ucs2_from_user(&name, setvariable.variable_name);
 260                 if (rv)
 261                         return rv;
 262         }
 263
 264         data = memdup_user(setvariable.data, setvariable.data_size);
 265         if (IS_ERR(data)) {
 266                 kfree(name);
 267                 return PTR_ERR(data);
 268         }
 269
 270         status = efi.set_variable(name, &vendor_guid,
 271                                 setvariable.attributes,
 272                                 setvariable.data_size, data);
 273
 274         if (put_user(status, setvariable.status)) {
 275                 rv = -EFAULT;
 276                 goto out;
 277         }
 278
 279         rv = status == EFI_SUCCESS ? 0 : -EINVAL;
 280
 281 out:
 282         kfree(data);
 283         kfree(name);
 284
 285         return rv;
 286 }
 287
 288 static long efi_runtime_get_time(unsigned long arg)
 289 {
 290         struct efi_gettime __user *gettime_user;
 291         struct efi_gettime  gettime;
 292         efi_status_t status;
 293         efi_time_cap_t cap;
 294         efi_time_t efi_time;
 295
 296         gettime_user = (struct efi_gettime __user *)arg;
 297         if (copy_from_user(&gettime, gettime_user, sizeof(gettime)))
 298                 return -EFAULT;
 299
 300         status = efi.get_time(gettime.time ? &efi_time : NULL,
 301                               gettime.capabilities ? &cap : NULL);
 302
 303         if (put_user(status, gettime.status))
 304                 return -EFAULT;
 305
 306         if (status != EFI_SUCCESS)
 307                 return -EINVAL;
 308
 309         if (gettime.capabilities) {
 310                 efi_time_cap_t __user *cap_local;
 311
 312                 cap_local = (efi_time_cap_t *)gettime.capabilities;
 313                 if (put_user(cap.resolution, &(cap_local->resolution)) ||
 314                         put_user(cap.accuracy, &(cap_local->accuracy)) ||
 315                         put_user(cap.sets_to_zero, &(cap_local->sets_to_zero)))
 316                         return -EFAULT;
 317         }
 318         if (gettime.time) {
 319                 if (copy_to_user(gettime.time, &efi_time, sizeof(efi_time_t)))
 320                         return -EFAULT;
 321         }
 322
 323         return 0;
 324 }
 325
 326 static long efi_runtime_set_time(unsigned long arg)
 327 {
 328         struct efi_settime __user *settime_user;
 329         struct efi_settime settime;
 330         efi_status_t status;
 331         efi_time_t efi_time;
 332
 333         settime_user = (struct efi_settime __user *)arg;
 334         if (copy_from_user(&settime, settime_user, sizeof(settime)))
 335                 return -EFAULT;
 336         if (copy_from_user(&efi_time, settime.time,
 337                                         sizeof(efi_time_t)))
 338                 return -EFAULT;
 339         status = efi.set_time(&efi_time);
 340
 341         if (put_user(status, settime.status))
 342                 return -EFAULT;
 343
 344         return status == EFI_SUCCESS ? 0 : -EINVAL;
 345 }
 346
 347 static long efi_runtime_get_waketime(unsigned long arg)
 348 {
 349         struct efi_getwakeuptime __user *getwakeuptime_user;
 350         struct efi_getwakeuptime getwakeuptime;
 351         efi_bool_t enabled, pending;
 352         efi_status_t status;
 353         efi_time_t efi_time;
 354
 355         getwakeuptime_user = (struct efi_getwakeuptime __user *)arg;
 356         if (copy_from_user(&getwakeuptime, getwakeuptime_user,
 357                                 sizeof(getwakeuptime)))
 358                 return -EFAULT;
 359
 360         status = efi.get_wakeup_time(
 361                 getwakeuptime.enabled ? (efi_bool_t *)&enabled : NULL,
 362                 getwakeuptime.pending ? (efi_bool_t *)&pending : NULL,
 363                 getwakeuptime.time ? &efi_time : NULL);
 364
 365         if (put_user(status, getwakeuptime.status))
 366                 return -EFAULT;
 367
 368         if (status != EFI_SUCCESS)
 369                 return -EINVAL;
 370
 371         if (getwakeuptime.enabled && put_user(enabled,
 372                                                 getwakeuptime.enabled))
 373                 return -EFAULT;
 374
 375         if (getwakeuptime.time) {
 376                 if (copy_to_user(getwakeuptime.time, &efi_time,
 377                                 sizeof(efi_time_t)))
 378                         return -EFAULT;
 379         }
 380
 381         return 0;
 382 }
 383
 384 static long efi_runtime_set_waketime(unsigned long arg)
 385 {
 386         struct efi_setwakeuptime __user *setwakeuptime_user;
 387         struct efi_setwakeuptime setwakeuptime;
 388         efi_bool_t enabled;
 389         efi_status_t status;
 390         efi_time_t efi_time;
 391
 392         setwakeuptime_user = (struct efi_setwakeuptime __user *)arg;
 393
 394         if (copy_from_user(&setwakeuptime, setwakeuptime_user,
 395                                 sizeof(setwakeuptime)))
 396                 return -EFAULT;
 397
 398         enabled = setwakeuptime.enabled;
 399         if (setwakeuptime.time) {
 400                 if (copy_from_user(&efi_time, setwakeuptime.time,
 401                                         sizeof(efi_time_t)))
 402                         return -EFAULT;
 403
 404                 status = efi.set_wakeup_time(enabled, &efi_time);
 405         } else
 406                 status = efi.set_wakeup_time(enabled, NULL);
 407
 408         if (put_user(status, setwakeuptime.status))
 409                 return -EFAULT;
 410
 411         return status == EFI_SUCCESS ? 0 : -EINVAL;
 412 }
 413
 414 static long efi_runtime_get_nextvariablename(unsigned long arg)
 415 {
 416         struct efi_getnextvariablename __user *getnextvariablename_user;
 417         struct efi_getnextvariablename getnextvariablename;
 418         unsigned long name_size, prev_name_size = 0, *ns = NULL;
 419         efi_status_t status;
 420         efi_guid_t *vd = NULL;
 421         efi_guid_t vendor_guid;
 422         efi_char16_t *name = NULL;
 423         int rv = 0;
 424
 425         getnextvariablename_user = (struct efi_getnextvariablename __user *)arg;
 426
 427         if (copy_from_user(&getnextvariablename, getnextvariablename_user,
 428                            sizeof(getnextvariablename)))
 429                 return -EFAULT;
 430
 431         if (getnextvariablename.variable_name_size) {
 432                 if (get_user(name_size, getnextvariablename.variable_name_size))
 433                         return -EFAULT;
 434                 ns = &name_size;
 435                 prev_name_size = name_size;
 436         }
 437
 438         if (getnextvariablename.vendor_guid) {
 439                 if (copy_from_user(&vendor_guid,
 440                                 getnextvariablename.vendor_guid,
 441                                 sizeof(vendor_guid)))
 442                         return -EFAULT;
 443                 vd = &vendor_guid;
 444         }
 445
 446         if (getnextvariablename.variable_name) {
 447                 size_t name_string_size = 0;
 448
 449                 rv = get_ucs2_strsize_from_user(
 450                                 getnextvariablename.variable_name,
 451                                 &name_string_size);
 452                 if (rv)
 453                         return rv;
 454                 /*
 455                  * The name_size may be smaller than the real buffer size where
 456                  * variable name located in some use cases. The most typical
 457                  * case is passing a 0 to get the required buffer size for the
 458                  * 1st time call. So we need to copy the content from user
 459                  * space for at least the string size of variable name, or else
 460                  * the name passed to UEFI may not be terminated as we expected.
 461                  */
 462                 rv = copy_ucs2_from_user_len(&name,
 463                                 getnextvariablename.variable_name,
 464                                 prev_name_size > name_string_size ?
 465                                 prev_name_size : name_string_size);
 466                 if (rv)
 467                         return rv;
 468         }
 469
 470         status = efi.get_next_variable(ns, name, vd);
 471
 472         if (put_user(status, getnextvariablename.status)) {
 473                 rv = -EFAULT;
 474                 goto out;
 475         }
 476
 477         if (status != EFI_SUCCESS) {
 478                 if (status == EFI_BUFFER_TOO_SMALL) {
 479                         if (ns && put_user(*ns,
 480                                 getnextvariablename.variable_name_size)) {
 481                                 rv = -EFAULT;
 482                                 goto out;
 483                         }
 484                 }
 485                 rv = -EINVAL;
 486                 goto out;
 487         }
 488
 489         if (name) {
 490                 if (copy_ucs2_to_user_len(getnextvariablename.variable_name,
 491                                                 name, prev_name_size)) {
 492                         rv = -EFAULT;
 493                         goto out;
 494                 }
 495         }
 496
 497         if (ns) {
 498                 if (put_user(*ns, getnextvariablename.variable_name_size)) {
 499                         rv = -EFAULT;
 500                         goto out;
 501                 }
 502         }
 503
 504         if (vd) {
 505                 if (copy_to_user(getnextvariablename.vendor_guid, vd,
 506                                                         sizeof(efi_guid_t)))
 507                         rv = -EFAULT;
 508         }
 509
 510 out:
 511         kfree(name);
 512         return rv;
 513 }
 514
 515 static long efi_runtime_get_nexthighmonocount(unsigned long arg)
 516 {
 517         struct efi_getnexthighmonotoniccount __user *getnexthighmonocount_user;
 518         struct efi_getnexthighmonotoniccount getnexthighmonocount;
 519         efi_status_t status;
 520         u32 count;
 521
 522         getnexthighmonocount_user = (struct
 523                         efi_getnexthighmonotoniccount __user *)arg;
 524
 525         if (copy_from_user(&getnexthighmonocount,
 526                            getnexthighmonocount_user,
 527                            sizeof(getnexthighmonocount)))
 528                 return -EFAULT;
 529
 530         status = efi.get_next_high_mono_count(
 531                 getnexthighmonocount.high_count ? &count : NULL);
 532
 533         if (put_user(status, getnexthighmonocount.status))
 534                 return -EFAULT;
 535
 536         if (status != EFI_SUCCESS)
 537                 return -EINVAL;
 538
 539         if (getnexthighmonocount.high_count &&
 540             put_user(count, getnexthighmonocount.high_count))
 541                 return -EFAULT;
 542
 543         return 0;
 544 }
 545
 546 static long efi_runtime_reset_system(unsigned long arg)
 547 {
 548         struct efi_resetsystem __user *resetsystem_user;
 549         struct efi_resetsystem resetsystem;
 550         void *data = NULL;
 551
 552         resetsystem_user = (struct efi_resetsystem __user *)arg;
 553         if (copy_from_user(&resetsystem, resetsystem_user,
 554                                                 sizeof(resetsystem)))
 555                 return -EFAULT;
 556         if (resetsystem.data_size != 0) {
 557                 data = memdup_user((void *)resetsystem.data,
 558                                                 resetsystem.data_size);
 559                 if (IS_ERR(data))
 560                         return PTR_ERR(data);
 561         }
 562
 563         efi.reset_system(resetsystem.reset_type, resetsystem.status,
 564                                 resetsystem.data_size, (efi_char16_t *)data);
 565
 566         kfree(data);
 567         return 0;
 568 }
 569
 570 static long efi_runtime_query_variableinfo(unsigned long arg)
 571 {
 572         struct efi_queryvariableinfo __user *queryvariableinfo_user;
 573         struct efi_queryvariableinfo queryvariableinfo;
 574         efi_status_t status;
 575         u64 max_storage, remaining, max_size;
 576
 577         queryvariableinfo_user = (struct efi_queryvariableinfo __user *)arg;
 578
 579         if (copy_from_user(&queryvariableinfo, queryvariableinfo_user,
 580                            sizeof(queryvariableinfo)))
 581                 return -EFAULT;
 582
 583         status = efi.query_variable_info(queryvariableinfo.attributes,
 584                                          &max_storage, &remaining, &max_size);
 585
 586         if (put_user(status, queryvariableinfo.status))
 587                 return -EFAULT;
 588
 589         if (status != EFI_SUCCESS)
 590                 return -EINVAL;
 591
 592         if (put_user(max_storage,
 593                      queryvariableinfo.maximum_variable_storage_size))
 594                 return -EFAULT;
 595
 596         if (put_user(remaining,
 597                      queryvariableinfo.remaining_variable_storage_size))
 598                 return -EFAULT;
 599
 600         if (put_user(max_size, queryvariableinfo.maximum_variable_size))
 601                 return -EFAULT;
 602
 603         return 0;
 604 }
 605
 606 static long efi_runtime_query_capsulecaps(unsigned long arg)
 607 {
 608         struct efi_querycapsulecapabilities __user *qcaps_user;
 609         struct efi_querycapsulecapabilities qcaps;
 610         efi_capsule_header_t *capsules;
 611         efi_status_t status;
 612         u64 max_size;
 613         int i, reset_type;
 614         int rv = 0;
 615
 616         qcaps_user = (struct efi_querycapsulecapabilities __user *)arg;
 617
 618         if (copy_from_user(&qcaps, qcaps_user, sizeof(qcaps)))
 619                 return -EFAULT;
 620
 621         if (qcaps.capsule_count == ULONG_MAX)
 622                 return -EINVAL;
 623
 624         capsules = kcalloc(qcaps.capsule_count + 1,
 625                            sizeof(efi_capsule_header_t), GFP_KERNEL);
 626         if (!capsules)
 627                 return -ENOMEM;
 628
 629         for (i = 0; i < qcaps.capsule_count; i++) {
 630                 efi_capsule_header_t *c;
 631                 /*
 632                  * We cannot dereference qcaps.capsule_header_array directly to
 633                  * obtain the address of the capsule as it resides in the
 634                  * user space
 635                  */
 636                 if (get_user(c, qcaps.capsule_header_array + i)) {
 637                         rv = -EFAULT;
 638                         goto out;
 639                 }
 640                 if (copy_from_user(&capsules[i], c,
 641                                 sizeof(efi_capsule_header_t))) {
 642                         rv = -EFAULT;
 643                         goto out;
 644                 }
 645         }
 646
 647         qcaps.capsule_header_array = &capsules;
 648
 649         status = efi.query_capsule_caps((efi_capsule_header_t **)
 650                                         qcaps.capsule_header_array,
 651                                         qcaps.capsule_count,
 652                                         &max_size, &reset_type);
 653
 654         if (put_user(status, qcaps.status)) {
 655                 rv = -EFAULT;
 656                 goto out;
 657         }
 658
 659         if (status != EFI_SUCCESS) {
 660                 rv = -EINVAL;
 661                 goto out;
 662         }
 663
 664         if (put_user(max_size, qcaps.maximum_capsule_size)) {
 665                 rv = -EFAULT;
 666                 goto out;
 667         }
 668
 669         if (put_user(reset_type, qcaps.reset_type))
 670                 rv = -EFAULT;
 671
 672 out:
 673         kfree(capsules);
 674         return rv;
 675 }
 676
 677 static long efi_test_ioctl(struct file *file, unsigned int cmd,
 678                                                         unsigned long arg)
 679 {
 680         switch (cmd) {
 681         case EFI_RUNTIME_GET_VARIABLE:
 682                 return efi_runtime_get_variable(arg);
 683
 684         case EFI_RUNTIME_SET_VARIABLE:
 685                 return efi_runtime_set_variable(arg);
 686
 687         case EFI_RUNTIME_GET_TIME:
 688                 return efi_runtime_get_time(arg);
 689
 690         case EFI_RUNTIME_SET_TIME:
 691                 return efi_runtime_set_time(arg);
 692
 693         case EFI_RUNTIME_GET_WAKETIME:
 694                 return efi_runtime_get_waketime(arg);
 695
 696         case EFI_RUNTIME_SET_WAKETIME:
 697                 return efi_runtime_set_waketime(arg);
 698
 699         case EFI_RUNTIME_GET_NEXTVARIABLENAME:
 700                 return efi_runtime_get_nextvariablename(arg);
 701
 702         case EFI_RUNTIME_GET_NEXTHIGHMONOTONICCOUNT:
 703                 return efi_runtime_get_nexthighmonocount(arg);
 704
 705         case EFI_RUNTIME_QUERY_VARIABLEINFO:
 706                 return efi_runtime_query_variableinfo(arg);
 707
 708         case EFI_RUNTIME_QUERY_CAPSULECAPABILITIES:
 709                 return efi_runtime_query_capsulecaps(arg);
 710
 711         case EFI_RUNTIME_RESET_SYSTEM:
 712                 return efi_runtime_reset_system(arg);
 713         }
 714
 715         return -ENOTTY;
 716 }
 717
 718 static int efi_test_open(struct inode *inode, struct file *file)
 719 {
 720         /*
 721          * nothing special to do here
 722          * We do accept multiple open files at the same time as we
 723          * synchronize on the per call operation.
 724          */
 725         return 0;
 726 }
 727
 728 static int efi_test_close(struct inode *inode, struct file *file)
 729 {
 730         return 0;
 731 }
 732
 733 /*
 734  *      The various file operations we support.
 735  */
 736 static const struct file_operations efi_test_fops = {
 737         .owner          = THIS_MODULE,
 738         .unlocked_ioctl = efi_test_ioctl,
 739         .open           = efi_test_open,
 740         .release        = efi_test_close,
 741         .llseek         = no_llseek,
 742 };
 743
 744 static struct miscdevice efi_test_dev = {
 745         MISC_DYNAMIC_MINOR,
 746         "efi_test",
 747         &efi_test_fops
 748 };
 749
 750 static int __init efi_test_init(void)
 751 {
 752         int ret;
 753
 754         ret = misc_register(&efi_test_dev);
 755         if (ret) {
 756                 pr_err("efi_test: can't misc_register on minor=%d\n",
 757                         MISC_DYNAMIC_MINOR);
 758                 return ret;
 759         }
 760
 761         return 0;
 762 }
 763
 764 static void __exit efi_test_exit(void)
 765 {
 766         misc_deregister(&efi_test_dev);
 767 }
 768
 769 module_init(efi_test_init);
 770 module_exit(efi_test_exit);