summaryrefslogtreecommitdiffstats
path: root/drivers/firmware/efi/test/efi_test.c
blob: 7baf48c01e72f2f63e65e802609059da9cdb12ee (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
// SPDX-License-Identifier: GPL-2.0+
/*
 * EFI Test Driver for Runtime Services
 *
 * Copyright(C) 2012-2016 Canonical Ltd.
 *
 * This driver exports EFI runtime services interfaces into userspace, which
 * allow to use and test UEFI runtime services provided by firmware.
 *
 */

#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/efi.h>
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#include "efi_test.h"

MODULE_AUTHOR("Ivan Hu <ivan.hu@canonical.com>");
MODULE_DESCRIPTION("EFI Test Driver");
MODULE_LICENSE("GPL");

/*
 * Count the bytes in 'str', including the terminating NULL.
 *
 * Note this function returns the number of *bytes*, not the number of
 * ucs2 characters.
 */
static inline size_t user_ucs2_strsize(efi_char16_t  __user *str)
{
	efi_char16_t *s = str, c;
	size_t len;

	if (!str)
		return 0;

	/* Include terminating NULL */
	len = sizeof(efi_char16_t);

	if (get_user(c, s++)) {
		/* Can't read userspace memory for size */
		return 0;
	}

	while (c != 0) {
		if (get_user(c, s++)) {
			/* Can't read userspace memory for size */
			return 0;
		}
		len += sizeof(efi_char16_t);
	}
	return len;
}

/*
 * Allocate a buffer and copy a ucs2 string from user space into it.
 */
static inline int
copy_ucs2_from_user_len(efi_char16_t **dst, efi_char16_t __user *src,
			size_t len)
{
	efi_char16_t *buf;

	if (!src) {
		*dst = NULL;
		return 0;
	}

	if (!access_ok(src, 1))
		return -EFAULT;

	buf = memdup_user(src, len);
	if (IS_ERR(buf)) {
		*dst = NULL;
		return PTR_ERR(buf);
	}
	*dst = buf;

	return 0;
}

/*
 * Count the bytes in 'str', including the terminating NULL.
 *
 * Just a wrap for user_ucs2_strsize
 */
static inline int
get_ucs2_strsize_from_user(efi_char16_t __user *src, size_t *len)
{
	if (!access_ok(src, 1))
		return -EFAULT;

	*len = user_ucs2_strsize(src);
	if (*len == 0)
		return -EFAULT;

	return 0;
}

/*
 * Calculate the required buffer allocation size and copy a ucs2 string
 * from user space into it.
 *
 * This function differs from copy_ucs2_from_user_len() because it
 * calculates the size of the buffer to allocate by taking the length of
 * the string 'src'.
 *
 * If a non-zero value is returned, the caller MUST NOT access 'dst'.
 *
 * It is the caller's responsibility to free 'dst'.
 */
static inline int
copy_ucs2_from_user(efi_char16_t **dst, efi_char16_t __user *src)
{
	size_t len;

	if (!access_ok(src, 1))
		return -EFAULT;

	len = user_ucs2_strsize(src);
	if (len == 0)
		return -EFAULT;
	return copy_ucs2_from_user_len(dst, src, len);
}

/*
 * Copy a ucs2 string to a user buffer.
 *
 * This function is a simple wrapper around copy_to_user() that does
 * nothing if 'src' is NULL, which is useful for reducing the amount of
 * NULL checking the caller has to do.
 *
 * 'len' specifies the number of bytes to copy.
 */
static inline int
copy_ucs2_to_user_len(efi_char16_t __user *dst, efi_char16_t *src, size_t len)
{
	if (!src)
		return 0;

	if (!access_ok(dst, 1))
		return -EFAULT;

	return copy_to_user(dst, src, len);
}

static long efi_runtime_get_variable(unsigned long arg)
{
	struct efi_getvariable __user *getvariable_user;
	struct efi_getvariable getvariable;
	unsigned long datasize = 0, prev_datasize, *dz;
	efi_guid_t vendor_guid, *vd = NULL;
	efi_status_t status;
	efi_char16_t *name = NULL;
	u32 attr, *at;
	void *data = NULL;
	int rv = 0;

	getvariable_user = (struct efi_getvariable __user *)arg;

	if (copy_from_user(&getvariable, getvariable_user,
			   sizeof(getvariable)))
		return -EFAULT;
	if (getvariable.data_size &&
	    get_user(datasize, getvariable.data_size))
		return -EFAULT;
	if (getvariable.vendor_guid) {
		if (copy_from_user(&vendor_guid, getvariable.vendor_guid,
					sizeof(vendor_guid)))
			return -EFAULT;
		vd = &vendor_guid;
	}

	if (getvariable.variable_name) {
		rv = copy_ucs2_from_user(&name, getvariable.variable_name);
		if (rv)
			return rv;
	}

	at = getvariable.attributes ? &attr : NULL;
	dz = getvariable.data_size ? &datasize : NULL;

	if (getvariable.data_size && getvariable.data) {
		data = kmalloc(datasize, GFP_KERNEL);
		if (!data) {
			kfree(name);
			return -ENOMEM;
		}
	}

	prev_datasize = datasize;
	status = efi.get_variable(name, vd, at, dz, data);
	kfree(name);

	if (put_user(status, getvariable.status)) {
		rv = -EFAULT;
		goto out;
	}

	if (status != EFI_SUCCESS) {
		if (status == EFI_BUFFER_TOO_SMALL) {
			if (dz && put_user(datasize, getvariable.data_size)) {
				rv = -EFAULT;
				goto out;
			}
		}
		rv = -EINVAL;
		goto out;
	}

	if (prev_datasize < datasize) {
		rv = -EINVAL;
		goto out;
	}

	if (data) {
		if (copy_to_user(getvariable.data, data, datasize)) {
			rv = -EFAULT;
			goto out;
		}
	}

	if (at && put_user(attr, getvariable.attributes)) {
		rv = -EFAULT;
		goto out;
	}

	if (dz && put_user(datasize, getvariable.data_size))
		rv = -EFAULT;

out:
	kfree(data);
	return rv;

}

static long efi_runtime_set_variable(unsigned long arg)
{
	struct efi_setvariable __user *setvariable_user;
	struct efi_setvariable setvariable;
	efi_guid_t vendor_guid;
	efi_status_t status;
	efi_char16_t *name = NULL;
	void *data;
	int rv = 0;

	setvariable_user = (struct efi_setvariable __user *)arg;

	if (copy_from_user(&setvariable, setvariable_user, sizeof(setvariable)))
		return -EFAULT;
	if (copy_from_user(&vendor_guid, setvariable.vendor_guid,
				sizeof(vendor_guid)))
		return -EFAULT;

	if (setvariable.variable_name) {
		rv = copy_ucs2_from_user(&name, setvariable.variable_name);
		if (rv)
			return rv;
	}

	data = memdup_user(setvariable.data, setvariable.data_size);
	if (IS_ERR(data)) {
		kfree(name);
		return PTR_ERR(data);
	}

	status = efi.set_variable(name, &vendor_guid,
				setvariable.attributes,
				setvariable.data_size, data);

	if (put_user(status, setvariable.status)) {
		rv = -EFAULT;
		goto out;
	}

	rv = status == EFI_SUCCESS ? 0 : -EINVAL;

out:
	kfree(data);
	kfree(name);

	return rv;
}

static long efi_runtime_get_time(unsigned long arg)
{
	struct efi_gettime __user *gettime_user;
	struct efi_gettime  gettime;
	efi_status_t status;
	efi_time_cap_t cap;
	efi_time_t efi_time;

	gettime_user = (struct efi_gettime __user *)arg;
	if (copy_from_user(&gettime, gettime_user, sizeof(gettime)))
		return -EFAULT;

	status = efi.get_time(gettime.time ? &efi_time : NULL,
			      gettime.capabilities ? &cap : NULL);

	if (put_user(status, gettime.status))
		return -EFAULT;

	if (status != EFI_SUCCESS)
		return -EINVAL;

	if (gettime.capabilities) {
		efi_time_cap_t __user *cap_local;

		cap_local = (efi_time_cap_t *)gettime.capabilities;
		if (put_user(cap.resolution, &(cap_local->resolution)) ||
			put_user(cap.accuracy, &(cap_local->accuracy)) ||
			put_user(cap.sets_to_zero, &(cap_local->sets_to_zero)))
			return -EFAULT;
	}
	if (gettime.time) {
		if (copy_to_user(gettime.time, &efi_time, sizeof(efi_time_t)))
			return -EFAULT;
	}

	return 0;
}

static long efi_runtime_set_time(unsigned long arg)
{
	struct efi_settime __user *settime_user;
	struct efi_settime settime;
	efi_status_t status;
	efi_time_t efi_time;

	settime_user = (struct efi_settime __user *)arg;
	if (copy_from_user(&settime, settime_user, sizeof(settime)))
		return -EFAULT;
	if (copy_from_user(&efi_time, settime.time,
					sizeof(efi_time_t)))
		return -EFAULT;
	status = efi.set_time(&efi_time);

	if (put_user(status, settime.status))
		return -EFAULT;

	return status == EFI_SUCCESS ? 0 : -EINVAL;
}

static long efi_runtime_get_waketime(unsigned long arg)
{
	struct efi_getwakeuptime __user *getwakeuptime_user;
	struct efi_getwakeuptime getwakeuptime;
	efi_bool_t enabled, pending;
	efi_status_t status;
	efi_time_t efi_time;

	getwakeuptime_user = (struct efi_getwakeuptime __user *)arg;
	if (copy_from_user(&getwakeuptime, getwakeuptime_user,
				sizeof(getwakeuptime)))
		return -EFAULT;

	status = efi.get_wakeup_time(
		getwakeuptime.enabled ? (efi_bool_t *)&enabled : NULL,
		getwakeuptime.pending ? (efi_bool_t *)&pending : NULL,
		getwakeuptime.time ? &efi_time : NULL);

	if (put_user(status, getwakeuptime.status))
		return -EFAULT;

	if (status != EFI_SUCCESS)
		return -EINVAL;

	if (getwakeuptime.enabled && put_user(enabled,
						getwakeuptime.enabled))
		return -EFAULT;

	if (getwakeuptime.time) {
		if (copy_to_user(getwakeuptime.time, &efi_time,
				sizeof(efi_time_t)))
			return -EFAULT;
	}

	return 0;
}

static long efi_runtime_set_waketime(unsigned long arg)
{
	struct efi_setwakeuptime __user *setwakeuptime_user;
	struct efi_setwakeuptime setwakeuptime;
	efi_bool_t enabled;
	efi_status_t status;
	efi_time_t efi_time;

	setwakeuptime_user = (struct efi_setwakeuptime __user *)arg;

	if (copy_from_user(&setwakeuptime, setwakeuptime_user,
				sizeof(setwakeuptime)))
		return -EFAULT;

	enabled = setwakeuptime.enabled;
	if (setwakeuptime.time) {
		if (copy_from_user(&efi_time, setwakeuptime.time,
					sizeof(efi_time_t)))
			return -EFAULT;

		status = efi.set_wakeup_time(enabled, &efi_time);
	} else
		status = efi.set_wakeup_time(enabled, NULL);

	if (put_user(status, setwakeuptime.status))
		return -EFAULT;

	return status == EFI_SUCCESS ? 0 : -EINVAL;
}

static long efi_runtime_get_nextvariablename(unsigned long arg)
{
	struct efi_getnextvariablename __user *getnextvariablename_user;
	struct efi_getnextvariablename getnextvariablename;
	unsigned long name_size, prev_name_size = 0, *ns = NULL;
	efi_status_t status;
	efi_guid_t *vd = NULL;
	efi_guid_t vendor_guid;
	efi_char16_t *name = NULL;
	int rv = 0;

	getnextvariablename_user = (struct efi_getnextvariablename __user *)arg;

	if (copy_from_user(&getnextvariablename, getnextvariablename_user,
			   sizeof(getnextvariablename)))
		return -EFAULT;

	if (getnextvariablename.variable_name_size) {
		if (get_user(name_size, getnextvariablename.variable_name_size))
			return -EFAULT;
		ns = &name_size;
		prev_name_size = name_size;
	}

	if (getnextvariablename.vendor_guid) {
		if (copy_from_user(&vendor_guid,
				getnextvariablename.vendor_guid,
				sizeof(vendor_guid)))
			return -EFAULT;
		vd = &vendor_guid;
	}

	if (getnextvariablename.variable_name) {
		size_t name_string_size = 0;

		rv = get_ucs2_strsize_from_user(
				getnextvariablename.variable_name,
				&name_string_size);
		if (rv)
			return rv;
		/*
		 * The name_size may be smaller than the real buffer size where
		 * variable name located in some use cases. The most typical
		 * case is passing a 0 to get the required buffer size for the
		 * 1st time call. So we need to copy the content from user
		 * space for at least the string size of variable name, or else
		 * the name passed to UEFI may not be terminated as we expected.
		 */
		rv = copy_ucs2_from_user_len(&name,
				getnextvariablename.variable_name,
				prev_name_size > name_string_size ?
				prev_name_size : name_string_size);
		if (rv)
			return rv;
	}

	status = efi.get_next_variable(ns, name, vd);

	if (put_user(status, getnextvariablename.status)) {
		rv = -EFAULT;
		goto out;
	}

	if (status != EFI_SUCCESS) {
		if (status == EFI_BUFFER_TOO_SMALL) {
			if (ns && put_user(*ns,
				getnextvariablename.variable_name_size)) {
				rv = -EFAULT;
				goto out;
			}
		}
		rv = -EINVAL;
		goto out;
	}

	if (name) {
		if (copy_ucs2_to_user_len(getnextvariablename.variable_name,
						name, prev_name_size)) {
			rv = -EFAULT;
			goto out;
		}
	}

	if (ns) {
		if (put_user(*ns, getnextvariablename.variable_name_size)) {
			rv = -EFAULT;
			goto out;
		}
	}

	if (vd) {
		if (copy_to_user(getnextvariablename.vendor_guid, vd,
							sizeof(efi_guid_t)))
			rv = -EFAULT;
	}

out:
	kfree(name);
	return rv;
}

static long efi_runtime_get_nexthighmonocount(unsigned long arg)
{
	struct efi_getnexthighmonotoniccount __user *getnexthighmonocount_user;
	struct efi_getnexthighmonotoniccount getnexthighmonocount;
	efi_status_t status;
	u32 count;

	getnexthighmonocount_user = (struct
			efi_getnexthighmonotoniccount __user *)arg;

	if (copy_from_user(&getnexthighmonocount,
			   getnexthighmonocount_user,
			   sizeof(getnexthighmonocount)))
		return -EFAULT;

	status = efi.get_next_high_mono_count(
		getnexthighmonocount.high_count ? &count : NULL);

	if (put_user(status, getnexthighmonocount.status))
		return -EFAULT;

	if (status != EFI_SUCCESS)
		return -EINVAL;

	if (getnexthighmonocount.high_count &&
	    put_user(count, getnexthighmonocount.high_count))
		return -EFAULT;

	return 0;
}

static long efi_runtime_reset_system(unsigned long arg)
{
	struct efi_resetsystem __user *resetsystem_user;
	struct efi_resetsystem resetsystem;
	void *data = NULL;

	resetsystem_user = (struct efi_resetsystem __user *)arg;
	if (copy_from_user(&resetsystem, resetsystem_user,
						sizeof(resetsystem)))
		return -EFAULT;
	if (resetsystem.data_size != 0) {
		data = memdup_user((void *)resetsystem.data,
						resetsystem.data_size);
		if (IS_ERR(data))
			return PTR_ERR(data);
	}

	efi.reset_system(resetsystem.reset_type, resetsystem.status,
				resetsystem.data_size, (efi_char16_t *)data);

	kfree(data);
	return 0;
}

static long efi_runtime_query_variableinfo(unsigned long arg)
{
	struct efi_queryvariableinfo __user *queryvariableinfo_user;
	struct efi_queryvariableinfo queryvariableinfo;
	efi_status_t status;
	u64 max_storage, remaining, max_size;

	queryvariableinfo_user = (struct efi_queryvariableinfo __user *)arg;

	if (copy_from_user(&queryvariableinfo, queryvariableinfo_user,
			   sizeof(queryvariableinfo)))
		return -EFAULT;

	status = efi.query_variable_info(queryvariableinfo.attributes,
					 &max_storage, &remaining, &max_size);

	if (put_user(status, queryvariableinfo.status))
		return -EFAULT;

	if (status != EFI_SUCCESS)
		return -EINVAL;

	if (put_user(max_storage,
		     queryvariableinfo.maximum_variable_storage_size))
		return -EFAULT;

	if (put_user(remaining,
		     queryvariableinfo.remaining_variable_storage_size))
		return -EFAULT;

	if (put_user(max_size, queryvariableinfo.maximum_variable_size))
		return -EFAULT;

	return 0;
}

static long efi_runtime_query_capsulecaps(unsigned long arg)
{
	struct efi_querycapsulecapabilities __user *qcaps_user;
	struct efi_querycapsulecapabilities qcaps;
	efi_capsule_header_t *capsules;
	efi_status_t status;
	u64 max_size;
	int i, reset_type;
	int rv = 0;

	qcaps_user = (struct efi_querycapsulecapabilities __user *)arg;

	if (copy_from_user(&qcaps, qcaps_user, sizeof(qcaps)))
		return -EFAULT;

	if (qcaps.capsule_count == ULONG_MAX)
		return -EINVAL;

	capsules = kcalloc(qcaps.capsule_count + 1,
			   sizeof(efi_capsule_header_t), GFP_KERNEL);
	if (!capsules)
		return -ENOMEM;

	for (i = 0; i < qcaps.capsule_count; i++) {
		efi_capsule_header_t *c;
		/*
		 * We cannot dereference qcaps.capsule_header_array directly to
		 * obtain the address of the capsule as it resides in the
		 * user space
		 */
		if (get_user(c, qcaps.capsule_header_array + i)) {
			rv = -EFAULT;
			goto out;
		}
		if (copy_from_user(&capsules[i], c,
				sizeof(efi_capsule_header_t))) {
			rv = -EFAULT;
			goto out;
		}
	}

	qcaps.capsule_header_array = &capsules;

	status = efi.query_capsule_caps((efi_capsule_header_t **)
					qcaps.capsule_header_array,
					qcaps.capsule_count,
					&max_size, &reset_type);

	if (put_user(status, qcaps.status)) {
		rv = -EFAULT;
		goto out;
	}

	if (status != EFI_SUCCESS) {
		rv = -EINVAL;
		goto out;
	}

	if (put_user(max_size, qcaps.maximum_capsule_size)) {
		rv = -EFAULT;
		goto out;
	}

	if (put_user(reset_type, qcaps.reset_type))
		rv = -EFAULT;

out:
	kfree(capsules);
	return rv;
}

static long efi_test_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	switch (cmd) {
	case EFI_RUNTIME_GET_VARIABLE:
		return efi_runtime_get_variable(arg);

	case EFI_RUNTIME_SET_VARIABLE:
		return efi_runtime_set_variable(arg);

	case EFI_RUNTIME_GET_TIME:
		return efi_runtime_get_time(arg);

	case EFI_RUNTIME_SET_TIME:
		return efi_runtime_set_time(arg);

	case EFI_RUNTIME_GET_WAKETIME:
		return efi_runtime_get_waketime(arg);

	case EFI_RUNTIME_SET_WAKETIME:
		return efi_runtime_set_waketime(arg);

	case EFI_RUNTIME_GET_NEXTVARIABLENAME:
		return efi_runtime_get_nextvariablename(arg);

	case EFI_RUNTIME_GET_NEXTHIGHMONOTONICCOUNT:
		return efi_runtime_get_nexthighmonocount(arg);

	case EFI_RUNTIME_QUERY_VARIABLEINFO:
		return efi_runtime_query_variableinfo(arg);

	case EFI_RUNTIME_QUERY_CAPSULECAPABILITIES:
		return efi_runtime_query_capsulecaps(arg);

	case EFI_RUNTIME_RESET_SYSTEM:
		return efi_runtime_reset_system(arg);
	}

	return -ENOTTY;
}

static int efi_test_open(struct inode *inode, struct file *file)
{
	int ret = security_locked_down(LOCKDOWN_EFI_TEST);

	if (ret)
		return ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;
	/*
	 * nothing special to do here
	 * We do accept multiple open files at the same time as we
	 * synchronize on the per call operation.
	 */
	return 0;
}

static int efi_test_close(struct inode *inode, struct file *file)
{
	return 0;
}

/*
 *	The various file operations we support.
 */
static const struct file_operations efi_test_fops = {
	.owner		= THIS_MODULE,
	.unlocked_ioctl	= efi_test_ioctl,
	.open		= efi_test_open,
	.release	= efi_test_close,
	.llseek		= no_llseek,
};

static struct miscdevice efi_test_dev = {
	MISC_DYNAMIC_MINOR,
	"efi_test",
	&efi_test_fops
};

static int __init efi_test_init(void)
{
	int ret;

	ret = misc_register(&efi_test_dev);
	if (ret) {
		pr_err("efi_test: can't misc_register on minor=%d\n",
			MISC_DYNAMIC_MINOR);
		return ret;
	}

	return 0;
}

static void __exit efi_test_exit(void)
{
	misc_deregister(&efi_test_dev);
}

module_init(efi_test_init);
module_exit(efi_test_exit);