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