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 <ivan.hu@canonical.com>");
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 */
user_ucs2_strsize(efi_char16_t __user * str)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
copy_ucs2_from_user_len(efi_char16_t ** dst,efi_char16_t __user * src,size_t len)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
get_ucs2_strsize_from_user(efi_char16_t __user * src,size_t * len)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
copy_ucs2_from_user(efi_char16_t ** dst,efi_char16_t __user * src)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
copy_ucs2_to_user_len(efi_char16_t __user * dst,efi_char16_t * src,size_t len)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
efi_runtime_get_variable(unsigned long arg)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
efi_runtime_set_variable(unsigned long arg)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
efi_runtime_get_time(unsigned long arg)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
efi_runtime_set_time(unsigned long arg)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
efi_runtime_get_waketime(unsigned long arg)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
efi_runtime_set_waketime(unsigned long arg)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
efi_runtime_get_nextvariablename(unsigned long arg)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
efi_runtime_get_nexthighmonocount(unsigned long arg)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
efi_runtime_reset_system(unsigned long arg)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
efi_runtime_query_variableinfo(unsigned long arg)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
efi_runtime_query_capsulecaps(unsigned long arg)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
efi_runtime_get_supported_mask(unsigned long arg)666 static long efi_runtime_get_supported_mask(unsigned long arg)
667 {
668 unsigned int __user *supported_mask;
669 int rv = 0;
670
671 supported_mask = (unsigned int *)arg;
672
673 if (put_user(efi.runtime_supported_mask, supported_mask))
674 rv = -EFAULT;
675
676 return rv;
677 }
678
efi_test_ioctl(struct file * file,unsigned int cmd,unsigned long arg)679 static long efi_test_ioctl(struct file *file, unsigned int cmd,
680 unsigned long arg)
681 {
682 switch (cmd) {
683 case EFI_RUNTIME_GET_VARIABLE:
684 return efi_runtime_get_variable(arg);
685
686 case EFI_RUNTIME_SET_VARIABLE:
687 return efi_runtime_set_variable(arg);
688
689 case EFI_RUNTIME_GET_TIME:
690 return efi_runtime_get_time(arg);
691
692 case EFI_RUNTIME_SET_TIME:
693 return efi_runtime_set_time(arg);
694
695 case EFI_RUNTIME_GET_WAKETIME:
696 return efi_runtime_get_waketime(arg);
697
698 case EFI_RUNTIME_SET_WAKETIME:
699 return efi_runtime_set_waketime(arg);
700
701 case EFI_RUNTIME_GET_NEXTVARIABLENAME:
702 return efi_runtime_get_nextvariablename(arg);
703
704 case EFI_RUNTIME_GET_NEXTHIGHMONOTONICCOUNT:
705 return efi_runtime_get_nexthighmonocount(arg);
706
707 case EFI_RUNTIME_QUERY_VARIABLEINFO:
708 return efi_runtime_query_variableinfo(arg);
709
710 case EFI_RUNTIME_QUERY_CAPSULECAPABILITIES:
711 return efi_runtime_query_capsulecaps(arg);
712
713 case EFI_RUNTIME_RESET_SYSTEM:
714 return efi_runtime_reset_system(arg);
715
716 case EFI_RUNTIME_GET_SUPPORTED_MASK:
717 return efi_runtime_get_supported_mask(arg);
718 }
719
720 return -ENOTTY;
721 }
722
efi_test_open(struct inode * inode,struct file * file)723 static int efi_test_open(struct inode *inode, struct file *file)
724 {
725 int ret = security_locked_down(LOCKDOWN_EFI_TEST);
726
727 if (ret)
728 return ret;
729
730 if (!capable(CAP_SYS_ADMIN))
731 return -EACCES;
732 /*
733 * nothing special to do here
734 * We do accept multiple open files at the same time as we
735 * synchronize on the per call operation.
736 */
737 return 0;
738 }
739
efi_test_close(struct inode * inode,struct file * file)740 static int efi_test_close(struct inode *inode, struct file *file)
741 {
742 return 0;
743 }
744
745 /*
746 * The various file operations we support.
747 */
748 static const struct file_operations efi_test_fops = {
749 .owner = THIS_MODULE,
750 .unlocked_ioctl = efi_test_ioctl,
751 .open = efi_test_open,
752 .release = efi_test_close,
753 .llseek = no_llseek,
754 };
755
756 static struct miscdevice efi_test_dev = {
757 MISC_DYNAMIC_MINOR,
758 "efi_test",
759 &efi_test_fops
760 };
761
efi_test_init(void)762 static int __init efi_test_init(void)
763 {
764 int ret;
765
766 ret = misc_register(&efi_test_dev);
767 if (ret) {
768 pr_err("efi_test: can't misc_register on minor=%d\n",
769 MISC_DYNAMIC_MINOR);
770 return ret;
771 }
772
773 return 0;
774 }
775
efi_test_exit(void)776 static void __exit efi_test_exit(void)
777 {
778 misc_deregister(&efi_test_dev);
779 }
780
781 module_init(efi_test_init);
782 module_exit(efi_test_exit);
783
